CN104373397A

CN104373397A - Double hydraulic system and hydraulic machine

Info

Publication number: CN104373397A
Application number: CN201410579947.2A
Authority: CN
Inventors: 孙玉岗; 周路; 葛台代; 陈铭斌; 陈其永; 李敏
Original assignee: GUANGDONG HUAYE POWER TECHNOLOGY Co Ltd
Current assignee: GUANGDONG HUAYE POWER TECHNOLOGY Co Ltd
Priority date: 2014-10-24
Filing date: 2014-10-24
Publication date: 2015-02-25
Anticipated expiration: 2034-10-24
Also published as: CN104373397B

Abstract

The invention discloses a hydraulic machine and a double hydraulic system. The double hydraulic system comprises a first route of hydraulic system body and a second route of hydraulic system body. The double hydraulic system is of a logic linkage structure, and therefore the first route of hydraulic system body is used when the hydraulic machine is in the idle stroke (fast advancing) and the return stroke (fast retreating), and the large-flow rapid movement is achieved; high-pressure hydraulic oil is directly driven by the second route of hydraulic system body when the hydraulic machine is in the feeding stroke, and therefore the high-pressure system pressure can be directly obtained by the hydraulic machine, the higher working force can be obtained, and the overall weight of the hydraulic machine is reduced at a large proportion. By means of the double hydraulic system, the hydraulic machine can be applied under the power of 40 Mpa or higher, for instance, 40 Mpa, 55 Mpa, 70 Mpa, 100 Mpa, 120 Mpa, 150 Mpa and 200 Mpa, the overall weight of the hydraulic machine can be greatly reduced, all types of use efficiency, such as the running speed, of the hydraulic machine can be kept, and the production efficiency can be ensured.

Description

Double hydraulic system and hydraulic press

Technical field

The application relates to a kind of hydraulic press, especially relates to a kind of hydraulic press and the hydraulic system thereof that can realize high-voltage operation.

Background technique

Hydraulic press is a kind of is working medium with liquid, according to pascal's principle make for transferring energy to realize polytechnic machine.

Hydraulic press is a kind of machinery utilizing hydrostatic pressure to carry out the goods such as processing metal, plastics, rubber, timber, powder.It is usually used in pressing process and block pressing forming process, as: forging and stamping, punching press, cold-extruded, alignment, bending, flange, process of sheet drawing, powder metallurgy, press-fits etc.Its principle is the machinery utilizing liquid pressure transmission utilizing Pascal's law to make, and kind is a lot.Certainly, purposes is also diversified as required.

Hydraulic press generally by main frame, power system and hydraulic system three part form.Hydraulic system provides dynamic foundation with motor, uses oil hydraulic pump to be pressure by changes mechanical energy, promotes hydraulic oil.Change the flow direction of hydraulic oil by controlling various valve, thus promote the action that oil hydraulic cylinder makes different stroke, different direction, complete the action needs that various equipment is different.

Pump Direct driver is one of hydraulic system principal mode of hydraulic press.

The pump of pump Direct Driving System provides setting pressure working liquid body to oil hydraulic cylinder, and flow-distributing valve is used for changing feed flow direction, and relief valve is used for the restriction pressure of regulating system, plays safety overflow effect simultaneously.This drive system link is few, and structure is simple, and pressure can automatically increase or decrease by required working force, decreases power consumption, but must be decided the capacity of pump and drive motor thereof by the maximum functional power of hydraulic press and most high operation speed.

But due to the restriction of technology and material, do not find that the hydraulic press controlled by pressure pump valve Direct driver can be applicable to more than 35Mpa hydraulic system at present.

Though have existence individually more than the hydraulic press of 35Mpa system pressure, all realize by pressurized machine, this just brings, and pressure is slow, complex structure, the deficiency obviously reducing deadweight and lower energy consumption can not be reached.

Summary of the invention

The application provides a kind of hydraulic press and double hydraulic system.

According to the first aspect of the application, the application provides a kind of double hydraulic system, comprising:

First via hydraulic system, it comprises:

Low pressure pump group, described low pressure pump group is used for being connected with fuel tank;

First low pressure selector valve, described first low pressure selector valve has at least two-way output circuit, and the oil outlet of described low pressure pump group is connected with the first low pressure selector valve;

One way sequence valve, described one way sequence valve is connected with a wherein road output circuit of the first low pressure selector valve, and described one way sequence valve has oil outlet;

And high-pressure liquid-filling valve, described high-pressure liquid-filling valve has flow channels;

And the second tunnel hydraulic system, it comprises:

High pressure pump group, described high pressure pump group is used for being connected with fuel tank;

High-pressure reversing valve, described high-pressure reversing valve has at least one road output circuit, and the oil outlet of described high pressure pump group is connected with high-pressure reversing valve;

And high-pressure overflow valve, its filler opening is connected with the oil outlet of high pressure pump group.

As the further improvement of described double hydraulic system, described high-pressure liquid-filling valve comprises:

Valve component, described valve component has valve body chamber, the chamber wall in described valve body chamber offers the first flow channels and the second flow channels,

Also comprise:

Stuffing box gland, described stuffing box gland is that alloy steel material is made, and described stuffing box gland is fixed on valve component, and stuffing box gland has conical bore, and the hole wall of described conical bore has the groove of a circle spheric;

And seal, described seal is made up of special ceramic material, and it has the outer wall of a circle spheric, the outer wall of described spheric and the salable laminating of the groove of spheric.

According to the second aspect of the application, the application provides a kind of hydraulic press, comprise main frame and power system, described main frame comprises clutch release slave cylinder system and frame worktable, described clutch release slave cylinder system comprises master cylinder, fast cylinder and stationary cylinder, there is between described stationary cylinder and master cylinder master cylinder epicoele and master cylinder cavity of resorption, between described fast cylinder and master cylinder, there is quick chamber, it is characterized in that, also comprise the double hydraulic system described in above-mentioned any embodiment, described power system is connected with double hydraulic system, and control double hydraulic system fluid path trend, in described first via hydraulic system, a road output circuit of the first low pressure selector valve is connected with quick chamber, the oil outlet of described one way sequence valve is connected with master cylinder cavity of resorption, the flow channels of described high-pressure liquid-filling valve is connected with master cylinder epicoele, one road output circuit of described second tunnel hydraulic system mesohigh selector valve is connected with master cylinder epicoele, described double hydraulic system drives master cylinder F.F. under power system controls, work is entered or rewind.

The beneficial effect of the application is:

This hydraulic press adopts a kind of double hydraulic system, and this double hydraulic system comprises first via hydraulic system and the second tunnel hydraulic system, and this first via hydraulic system comprises low pressure pump group, the first low pressure selector valve and one way sequence valve.Second tunnel hydraulic system comprises high pressure pump group, high-pressure reversing valve and high-pressure overflow valve.This first via hydraulic system is connected with main frame respective chamber with the second tunnel hydraulic system, wherein first via hydraulic system is mainly in order to drive pressure head F.F. on main frame or rewind, this the second tunnel hydraulic system, by high pressure pump valve Direct driver, can be used for driving the pressure head work on main frame to enter.This high low pressure two overlaps hydraulic system logic linkage structure, hydraulic press is made to use low pressure in idle running (F.F.) and return (rewind), obtain large discharge rapid movement, and carry out in journey in work, hydraulic press can be accomplished by high-pressure service pump valve system Direct driver high pressure liquid force feed, make hydraulic press obtain fast directly high-pressure system pressure, obtain more high workload power, make vast scale alleviate hydraulic press overall weight.The application that this double hydraulic system not only makes this hydraulic press can realize at more than 40MPa, as 40Mpa, 55Mpa, 70Mpa, 100Mpa, 120Mpa, 150Mpa and 200Mpa etc., and can greatly alleviate hydraulic press overall weight, every effective utilization of hydraulic press can be kept simultaneously, such as motion speed etc., ensure manufacturing efficiency.

Accompanying drawing explanation

Fig. 1 is a kind of example structure schematic diagram of the application's hydraulic press;

Fig. 2 is the structural representation of a kind of embodiment of the application's double hydraulic system;

Fig. 3 is that clutch release slave cylinder system embodiment illustrated in fig. 1 is at F.F. status architecture schematic diagram;

Fig. 4 is that clutch release slave cylinder system embodiment illustrated in fig. 1 enters status architecture schematic diagram in work;

Fig. 5 is that clutch release slave cylinder system embodiment illustrated in fig. 1 is at fast-rewinding state structural representation;

Fig. 6 is the structural representation of a kind of high-pressure plunger pump embodiment of the application;

Fig. 7 is middle plunger auxiliary structure schematic diagram embodiment illustrated in fig. 6;

Fig. 8-10 is the structural representation of a kind of high-voltage electromagnetic reversing valve embodiment of the application;

Figure 11-13 is the structural representation of a kind of high pressure of the application large footpath solenoid directional control valve embodiment;

Figure 14 is the structural representation of a kind of high-pressure overflow valve embodiment one of the application;

Figure 15-16 is the structural representation of a kind of high-pressure overflow valve embodiment two of the application;

Figure 17 is the structural representation of a kind of high-pressure overflow valve embodiment three of the application;

Figure 18 is the structural representation of a kind of high-pressure overflow valve embodiment of the application;

Figure 19-20 is the structural representation of a kind of high-pressure liquid-filling valve of the application embodiment one;

Figure 21 is the structural representation of a kind of high-pressure liquid-filling valve of the application embodiment two;

Figure 22 is the structural representation of a kind of high-pressure liquid-filling valve of the application embodiment three;

Figure 23 is the structural representation of a kind of high-pressure pipe connector embodiment of the application;

Figure 24-25 is the structural representation of a kind of high pressure check valve embodiment of the application.

Embodiment

By reference to the accompanying drawings the present invention is described in further detail below by embodiment.The application can realize with multiple different form, is not limited to the mode of execution described by the present embodiment.There is provided the object of following embodiment to be convenient to this to application disclosure clearer understanding thoroughly, wherein the words of the indicating position such as upper and lower, left and right is only for shown structure position in respective figure.

For convenience of description, more than 40MPa is collectively referred to as high pressure (in other embodiments, in more than 40MPa scope, a certain section also may be called as sub-high pressure, ultrahigh pressure etc.) by the application, is less than 40MPa and is collectively referred to as low pressure.

Embodiment:

The present embodiment provides a kind of hydraulic press.

Please refer to Fig. 1, this hydraulic press comprises main frame 100, power system 200 and hydraulic system 300.

Power system 200 hydraulic control system 300 makes oil hydraulic pump be pressure by changes mechanical energy, promotes hydraulic oil.And the flow direction of hydraulic oil is changed by valve various in hydraulic control system 300, thus promote the action that main frame 100 makes different stroke, different direction, complete the action needs that various equipment is different.

Power system 200 (automatical control system) sends to hydraulic system 300 the electric combination body controlling electric signal, can be simple some control knobs, switch, relay, also can be complicated PLC and computerized control system, or even the highly intelligent hierarchy of control.

Automatical control system can be combined with hydraulic press, is directly installed in frame body, to form mechanical-electrical-hydraulic integration hydraulic press.Or also can set up separately electric control cubicle or form electrohydraulic system cabinet together with hydraulic system 300.

Hydraulic system 300 take liquid as working medium, for hydraulic press transferring energy realizes the energy drives control system of various technological action, also claims hydraulic station, by a variety of form with form, can set up hydraulic station, with automatically controlled combination or directly incorporate in hydraulic press body

Particularly, please refer to Fig. 1, main frame 100 comprises frame 101, clutch release slave cylinder system, upper table 106, lower table 107, ejects cylinder 108.

Frame 101 is supporting parts of complete machine, can have various ways, and as frame type, single arm type, four column type, two pillars, planer-type etc., the present embodiment is depicted as on oil cylinder and puts frame type.

This clutch release slave cylinder system comprises stationary cylinder 102, master cylinder 103 and fast cylinder 104.

Stationary cylinder 102 is fixedly mounted in frame 101, and has P1, P2, P3, P4 tetra-mouths.

This master cylinder 103 is contained in stationary cylinder 102, and master cylinder 103 can move up and down by stationary cylinder 102 relatively.Master cylinder 103 is the oil hydraulic cylinders utilizing the work of hydraulic work principle, and export and carry the pressure of all nominal operation power, master cylinder 103 can be put above, also can be underlying, is set to example above in the present embodiment.

Please refer to Fig. 3-5, master cylinder 103 and stationary cylinder 102 form a master cylinder epicoele (A chamber) and master cylinder cavity of resorption (B chamber), and wherein P2, P4 mouth communicates with A chamber, and P1 mouth communicates with B chamber.

Utilize button-head hinge 105 to connect a upper table 106 (i.e. operating head) in the lower end of master cylinder 103, this upper table 106 moves up and down with master cylinder 103.Upper table 106 performs compacting work, is the hard parts directly contacted with workpiece or mould, can be provided with some T-slot, for fixing upper die tooling.

Fast cylinder 104 is also built-in low pressure (LP) cylinder, is under low pressure driving master cylinder 103 fast downlink to the little cylinder of hydraulic pressure of workpiece.Fast cylinder 104 is fixed on stationary cylinder 102, and extend in master cylinder 103, and forms quick chamber (C chamber) with master cylinder 103, and P3 and C chamber communicates.

Please continue to refer to Fig. 1, lower table 107 and eject the bottom that cylinder 108 is arranged at frame 101.

Lower table 107 is also chopping block (pier), is the hard parts of bearing hydraulic press pressure and place work piece, can be provided with some T-slot, for fixing bed die.

Ejecting cylinder 108 is be arranged at a small oil tank in the middle of lower table 107, and effect ejects workpiece after pressing component, i.e. the demoulding.

Below introduce the hydraulic system 300 of the present embodiment.

This hydraulic system 300 adopts double hydraulic system, and this double hydraulic system 300 comprises first via hydraulic system and the second tunnel hydraulic system.

Wherein, first via hydraulic system is low-pressure hydraulic system, and the second tunnel hydraulic system is high-pressure hydraulic.

Please refer to Fig. 2, this second tunnel hydraulic system comprises high pressure pump group 301, high-pressure reversing valve 302 and high-pressure overflow valve 303.This first via hydraulic system is connected with main frame respective chamber with the second tunnel hydraulic system, wherein first via hydraulic system is mainly in order to drive pressure head F.F. on main frame or rewind, this the second tunnel hydraulic system is by high pressure pump valve Direct driver, can be used for driving the pressure head work on main frame to enter, wherein, under work enters state, the hydraulic oil of more than 40MPa in the second tunnel hydraulic system, can be run.

Particularly, this first via hydraulic system is connected with master cylinder epicoele, master cylinder cavity of resorption and quick chamber, and the second tunnel hydraulic system is connected with master cylinder epicoele.This double hydraulic system 300 drives master cylinder 103 F.F. under power system 200 controls, work is entered or rewind.

Please continue to refer to Fig. 2, double hydraulic system 300 concrete structure that the present embodiment adopts is as follows:

This second tunnel hydraulic system comprises high pressure pump group 301, high-pressure reversing valve 302 and high-pressure overflow valve 303.

The oil suction chamber of high pressure pump group 301 is communicated with fuel tank through oil absorption filter 304 (filter fluid, also can save in other embodiments).The oil outlet of high pressure pump group 301 is connected with the filler opening of the P mouth (filler opening) of high-pressure reversing valve 302 and high-pressure overflow valve 303, and the oil outlet of high-pressure overflow valve 303 is then communicated with fuel tank (or other Fuel Tanking Units).

This high-pressure reversing valve 302 has a filler opening (P), a return opening (T) and at least one road output circuit, and such as the present embodiment adopts a four-way electromagnetic reversing valve 302 that can be applicable to more than 40MPa hydraulic system.Or high-pressure reversing valve also can replace this four-way electromagnetic reversing valve 302 with the three-way valve that can be applicable to more than 40MPa hydraulic system.

Certainly, in other embodiments, also other forms of selector valve can be adopted, as electro-hydraulic reversing valve.

An actuator port of this high-pressure reversing valve 302 is communicated in A chamber (i.e. output circuit), another actuator port is directly communicated in fuel tank (or other Fuel Tanking Units), and return opening is then communicated with fuel tank (or other Fuel Tanking Units) through drainback passage.

Certainly, also pressure-detecting device can be set on the hydraulic circuit of this second tunnel hydraulic system, as pressure gauge 305.

Also pressure control device can be set on the hydraulic circuit of this second tunnel hydraulic system, as electronic pressure controller 306.

Please continue to refer to Fig. 2, this first via hydraulic system comprises low pressure pump group 307, first low pressure selector valve 308, second low pressure selector valve 309, the 3rd low pressure selector valve 310, one way sequence valve 313 and high-pressure liquid-filling valve 312.

This low pressure pump group 307 comprises the second motor and oil hydraulic pump (such as oil hydraulic pump can select the vane pump for low service system).

This low pressure pump group 307 is communicated with fuel tank through oil absorption filter 315 (filter fluid, also can save in other embodiments).

The oil outlet of low pressure pump group 307 is communicated with the filler opening of the first low pressure selector valve 308, second low pressure selector valve 309 and the 3rd low pressure selector valve 310.

First low pressure selector valve 308, second low pressure selector valve 309 and the 3rd low pressure selector valve 310 all can adopt the solenoid directional control valve used under low pressure, it has a filler opening (P), a return opening (T) and at least two-way output circuit (this two-way output circuit can for two actuator ports A, B on same selector valve), a such as four-way electromagnetic reversing valve.Or in other embodiments, low pressure selector valve can be also a kind of composite structure, is namely combined by three-way valve, realizes the function of this four-way electromagnetic reversing valve.

The return opening of the first low pressure selector valve 308 connects fuel tank (or other Fuel Tanking Units) through drainback passage, a Double throttle check valve 311 (or also can respectively connect an one-way throttle valve at each actuator port) connected by two actuator port, and the two paths of this Double throttle check valve 311 connects C chamber and the one way sequence valve 313 of main frame 100 respectively.

Or, in other embodiments, two actuator ports of the first low pressure selector valve 308 also can be made directly to be connected with the C chamber of main frame 100 and one way sequence valve 313.

The return opening of the second low pressure selector valve 309 connects fuel tank through drainback passage, and two actuator port is then connected to the control oil cylinder of high-pressure liquid-filling valve 312, controls the opening and closing of high-pressure liquid-filling valve 312.

The flow channels of high-pressure liquid-filling valve 312 is connected with main frame 100A chamber and fuel tank respectively, and when high-pressure liquid-filling valve 312 is opened, fuel tank is communicated with A chamber.

Second low pressure selector valve 309 is integrated in first via hydraulic system, power, pump group, pipeline and valve class can be saved.

Certainly, in other embodiments, also high-pressure liquid-filling valve 312 is controlled by other hydraulic systems 300 independent of first via hydraulic system, the filler opening of such as the second low pressure selector valve 309 is connected with another oil hydraulic pump independently arranged, thus the independent opening and closing controlling high-pressure liquid-filling valve 312.

The return opening of the 3rd low pressure selector valve 310 connects fuel tank (or other Fuel Tanking Units) through drainback passage, a Double throttle check valve 317 (or also can respectively connect an one-way throttle valve at each actuator port) connected by two actuator port, the two paths of this Double throttle check valve 317 connects the upper lower oil cavitie of ejection cylinder respectively, ejects make the workpiece demoulding to control ejection cylinder.

3rd low pressure selector valve 310 is integrated in first via hydraulic system, power, pump group, pipeline and valve class can be saved.

Certainly, ejection cylinder also can be controlled by other hydraulic systems 300 independent of first via hydraulic system, such as the filler opening of the 3rd low pressure selector valve 310 is connected with another oil hydraulic pump independently arranged, thus the independent opening and closing controlling high-pressure liquid-filling valve 312.

Above first, second, third low pressure selector valve the present embodiment all can adopt the solenoid directional control valve used under low pressure.

Further, also can an one-way valve 325 (this one-way valve can adopt the one-way valve used in low service system) be set after low pressure pump group 307 oil outlet, flows backwards in order to prevent fluid.Also a low pressure relief valve 324 can be connect with the first low pressure selector valve 308, second low pressure selector valve 309 and the 3rd low pressure selector valve 310 after one-way valve.

One pressure relay 314 (as high-pressure relay) can also be set, this pressure relay 314 is installed on the hydraulic circuit of first via hydraulic system, it is a pressure measurement signal transmitter, and signal is issued automatical control system, then controls each selector valve work.In other embodiments, the hydraulic circuit of the second tunnel hydraulic system also can carry out corresponding detection control by installation high-voltage pressure relay.

Certainly, also pressure-detecting device can be set on the hydraulic circuit of this first via hydraulic system, as pressure gauge 316.

Further, also can tubular cooler 318 be set on the drainback passage be connected with double hydraulic system 300 and return filter 319 pairs of hydraulic oil process.

Also arrange simultaneously and fuel tank is also provided with air-strainer 321 carries out filtering, liquid level liquid thermometer 320 is set and measures.

This second tunnel hydraulic system adopts high pressure pump group 301, high-pressure reversing valve 302 and high-pressure overflow valve 303, all can bear the hydraulic oil of more than 40MPa, therefore the hydraulic oil of more than 40MPa is directly run in this hydraulic system 300 by pump valve, as 40Mpa, 55Mpa, 70Mpa, 100Mpa, 120Mpa, 150Mpa and 200Mpa etc.

Incorporated by reference to Fig. 2-5, the working procedure of this double hydraulic system 300 is summarized as follows:

1), F.F. state

As shown in Figure 3, in F.F. state, P4 mouth is closed, and P1 mouth, P2 mouth, P3 mouth are all opened.

High pressure pump group 301 and low pressure pump group 307 pump low-pressure hydraulic oil simultaneously.

The low-pressure hydraulic oil one road binders liquid that low pressure pump group 307 pumps, successively through an actuator port of the first solenoid directional control valve 308, the right channel of Double throttle check valve 311, arrives master cylinder 103, enters c chamber.

Now the low pressure oil of large discharge P3 mouth from Fig. 3 flows into C chamber, promotes master cylinder 103 fast downlink.Because C chamber sectional area is very little, so master cylinder 103 and operating head fast downlink can be made under the effect of large discharge low pressure oil.

Simultaneously, another road binders liquid that low pressure pump group 307 pumps enters the control oil cylinder (will introducing this control principle after a while) of high-pressure liquid-filling valve 312 through the second solenoid directional control valve 309 two actuator ports, ACTIVE CONTROL high-pressure liquid-filling valve 312 is opened, A chamber is communicated with fuel tank, and a large amount of fluid is filled into A chamber by P2 mouth.

Master cylinder 103 moves down and causes B chamber inner fluid pressure to become large, when pressure is higher than setting pressure, one way sequence valve 313 is opened, and is communicated with the left channel of Double throttle check valve 311, B chamber fluid enters drainback passage through the A T mouth of the first solenoid directional control valve 308, flows back to fuel tank.

Meanwhile, the hydraulic oil that high pressure pump group 301 pumps also is low pressure, makes oil suction chamber be full of hydraulic oil all the time.High-pressure reversing valve 302 is except drainback passage (PT mouth), other are all closed, and oil that high pressure pump group 301 pumps major part is directly distributed by the drainback passage of high-voltage electromagnetic selector valve and its high low pressure distributing valve and to be refluxed fuel tank through the low pressure relief valve 323 of high pressure pump group 301 own.

The oily small part that high pressure pump group 301 pumps to enter in high-pressure service pump low-pressure cavity for the lubrication of bearing, axle etc. from dedicated channel.

Or in other embodiments, also a connection channel can be set in the second tunnel hydraulic system and first via hydraulic system, this connecting passage is opened when needs, low pressure oil in second tunnel hydraulic system is incorporated in first via hydraulic system, participate in the work of low pressure oil system, power can be saved and increase oil mass.

2), pressing process (work enters state)

As shown in Figure 4, enter state in work, the P2 mouth at liquid-filling valve place is closed, and P1 mouth, P3 mouth and P4 mouth are all opened.

Touch workpiece when pressure head declines, the high low pressure distributing valve of high pressure pump group 301 cuts out low-pressure channel rapidly, and high-pressure channel is opened.

The low pressure slippage pump of high pressure pump group 301 now plays to the continuous repairing of oil suction chamber and provides partial lubrication effect in pump, and the high pressure liquid force feed pumped enters pressure duct, and now the P A mouth of high-voltage electromagnetic selector valve 302 is connected, and high pressure liquid force feed enters A chamber from P4 mouth.

A chamber is now full of hydraulic oil under the effect of high-pressure liquid-filling valve 312, and high pressure liquid force feed is once enter, and master hydraulic cylinder pressure reaches high-pressure rapidly, thus completes the working feed of workpiece compacting, and namely work is entered.

Pressure raises and informs pressure relay 314, and the meta P mouth of Control first solenoid directional control valve 308 is closed, and A, B, T mouth is connected, and the hydraulic oil in A mouth B mouth passage can freely be refluxed fuel tank.

Now low pressure pump group 307 pumps hydraulic oil and only supplies high-pressure liquid-filling valve and the possible demand of liftout tank, and remaining fluid force feed flows back to fuel tank.

When first via hydraulic system pressure increases, relay sender, the second solenoid directional control valve 309 action, controls high-pressure liquid-filling valve 312 and closes.

Now c lumen road is in free reflux state, has oil all the time in pipeline, and flows with pressure change, and c chamber increases will produce negative pressure, so a small amount of fluid continues to be filled into C chamber by P3 mouth.

The fluid in B chamber then flows back to fuel tank by P1 mouth.

Time more than setting pressure, one way sequence valve 313 is connected, and compressed oil enters drainback passage through A, T mouth of Double throttle check valve 311 left channel and solenoid directional control valve 14, enters fuel tank.

3), rewind process

As shown in Figure 5, at fast-rewinding state, P4 mouth is closed, and P1 mouth, P2 mouth and P3 mouth are all opened.

After compacting completes, high pressure pump group 3015 continues to keep pump oil, and high-voltage electromagnetic selector valve all cuts out except drainback passage (namely P, T mouth leads directly to, B mouth, and A mouth is closed).High-voltage oil liquid in high pressure pump group 301 pump oil-piping becomes low-pressure hydraulic oil through the off-load of high-voltage electromagnetic selector valve and high-pressure overflow valve 303 pressure release, again carries out aforementioned fuel feeding and oil return.

When loine pressure reduces to rating value, the high low pressure distributing valve of high pressure pump group 301 reopens low-pressure section, and repairing in high-pressure service pump oil suction chamber, makes oil suction chamber be full of hydraulic oil all the time.

The hydraulic oil overwhelming majority in high-pressure system is distributed by its high low pressure distributing valve and directly to be refluxed fuel tank by the drainback passage of high-voltage electromagnetic selector valve and the low pressure relief valve 323 of high pressure pump group 301 own, and small part to enter in high-pressure service pump low-pressure cavity for the lubrication of bearing, axle etc. from dedicated channel.

Now one group of connection of the first solenoid directional control valve 308 and Double throttle check valve 311, the low-pressure hydraulic oil that low pressure pump group 307 pumps enters B chamber by one way sequence valve 313, now large discharge low pressure oil flows into B chamber from P1 mouth, promote master cylinder 103 fast uplink, because B chamber is an anchor ring, sectional area is less, so under the effect of large discharge low pressure oil, the quick return of work master cylinder 103 and pressure head can be realized, Here it is Quick return.

Now high-pressure liquid-filling valve 312 is opened under the control of the second solenoid directional control valve 309, and the hydraulic oil in A chamber flows back to fuel tank rapidly through high-pressure liquid-filling valve 312 big orifice passage.Now fast cylinder 104 is also in oil return state, i.e. one group of connection of Double throttle check valve 311 and solenoid directional control valve, and hydraulic oil directly enters drainback passage, returns fuel tank by tubular cooler and return filter.

Need the workpiece of the demoulding, after pressure head rollback or when rollback is more than half, by connecting the 3rd solenoid directional control valve 310, hydraulic oil enters ejection cylinder through Double throttle check valve 311, complete the 3rd solenoid directional control valve 310 after ejecting to commutate, ejection cylinder return, Double throttle check valve 311 ejects speed for regulating.

This high low pressure two overlaps hydraulic system logic linkage structure, hydraulic press is made to use low pressure in idle running (F.F.) and return (rewind), obtain large discharge rapid movement, and carry out in journey in work, hydraulic press can be accomplished by high-pressure service pump valve system Direct driver high pressure liquid force feed, without the need to making hydraulic press obtain fast directly high-pressure system pressure, obtaining more high workload power, making vast scale alleviate hydraulic press overall weight.The application that this double hydraulic system 300 not only makes this hydraulic press can realize at more than 40MPa, as 40Mpa, 55Mpa, 70Mpa, 100Mpa, 120Mpa, 150Mpa and 200Mpa etc., and can greatly alleviate hydraulic press overall weight, every effective utilization of hydraulic press can be kept simultaneously, such as motion speed etc., ensure manufacturing efficiency.

In general, the larger pressure of tonnage is higher, and this high-pressure press series advantage is just more obvious, for 70Mpa hydraulic press, with the same table top of low pressure, reduce 30%-300% with opening to conduct oneself with dignity compared with grade press, energy consumption reduces 5%-30%, and working efficiency is also slightly high.

Now with conventional 315T, the Main Economic technical parameter contrast of 500T, 1200T hydraulic press illustrates the superiority of present techniques.We with hydraulic press on the market and present techniques hydraulic press series in contrast source (major part sets identical index and does not list one by one, as bed dimension, open a grade size, total kilometres, ejection stroke etc.), in form, normal pressure one is classified as existing correlation technique, and ultrahigh pressure one is classified as present techniques:

One, a frame type hydraulic press that can be used for the products such as the compacting of hard small metallic articles product (as watch shell) precision and materials synthesis such as alloyed steel

Two, a medium-sized forming press of frame type that can be used for compacting LED lamp, watch shell, tableware etc.

Three, a production is compared with the four column type cold extrusion press of the products such as food platter

As can be seen from above several type contrast, the application's hydraulic press series technique, compared with prior art hydraulic press, has unrivaled advantage.Only for the 70Mpa that this technology is general, with the same table top of low pressure, reduce 30%-300% with opening to conduct oneself with dignity compared with grade press, energy consumption reduces 5%-30%.

Be not difficult to find out from upper several example, the work speed of the work speed press more outstanding in prior art of the application's hydraulic press series is lower, this is not that this technology can not improve work speed, but accepts or rejects from many-sided balance such as practical application operating mode, power components and parts, energy consumption the parameter drawn.

This high pressure pump group 301 comprises the first motor and can be used for the oil hydraulic pump of more than 40MPa hydraulic system, the first motor-driven hydraulic pumps work.

In other embodiments, high pressure pump group 301 can also comprise low pressure relief valve, and high pressure pump group 301 is connected with fuel tank by this relief valve.The effect of low pressure relief valve is oil return while of ensureing certain pressure, and it is connected with high low pressure distributing valve and fuel tank, and on Fig. 2, low pressure relief valve and pipeline connecting line only represent oil circuit control line

High pressure pump group 301 can also comprise high pressure check valve 322, and several are right for one group, often pair of in line check valve and oil outlet one-way valve.High pressure check valve 322 is connected with oil hydraulic pump

Below continue to set forth subassembly selection in this double hydraulic system 300.

The present embodiment provides a kind of plunger pump example as oil hydraulic pump.

Certainly, other oil hydraulic pumps that can be applicable to more than 40MPa hydraulic system also can be selected to replace plunger pump shown in this example.

First this example plunger pump provides a kind of trunk piston set assembly, comprise plunger body and plunger, described plunger body has installation cavity and plunger hole, also comprise plunger bushing, described plunger and plunger bushing adopt special ceramic material to make, described plunger bushing has plunger cavity, described plunger bushing is fixed in the installation cavity of plunger body, described plunger cavity is communicated with the plunger hole on plunger body, described plunger body one end is stretched in plunger cavity from plunger hole, described plunger and plunger cavity inwall form sliding pair, and adopt clearance seal, and described clearance seal size is 0.001-0.012mm.

As the further improvement of trunk piston set assembly, described clearance seal size is 0.002-0.009mm.

As the further improvement of trunk piston set assembly, described clearance seal size is 0.002-0.004mm.

As the further improvement of trunk piston set assembly, described plunger body outer wall is provided with at least one circular groove.

As the further improvement of trunk piston set assembly, described circular groove is more than two, and described circular groove is set up in parallel along plunger body radial direction.

As the further improvement of trunk piston set assembly, also comprise latch bracket and spring, described latch bracket has through hole, described plunger comprises plunger rod and piston cap, described plunger rod and piston cap are fixedly connected, described plunger rod passes from through hole, and described piston cap is stuck in latch bracket side, and described spring is connected between latch bracket and plunger body.

As the further improvement of trunk piston set assembly, also comprise the guide sleeve that coupled columns fills in row guiding, described guide sleeve one end and latch bracket are fixed, and its other end is set on plunger body outer wall.

This example plunger pump comprises the pump housing and driving mechanism, also comprise at least one trunk piston set assembly as described in above any one, described plunger body is sealingly fastened on the pump housing, described plunger, plunger body, plunger bushing and the pump housing enclose pump grease chamber, the locular wall of described pump grease chamber has the hydraulic fluid port for passing in and out fluid, described driving mechanism coordinates with plunger, and drive plunger moves back and forth, and changes the volume size of pump grease chamber.

As the further improvement of plunger pump, described driving mechanism comprises wobbler shaft and plane bearing, described wobbler shaft has the supporting surface of inclination, and wherein said plane bearing is placed on supporting surface, and the end face that described plane bearing does not rotate with wobbler shaft props up plunger.

As the further improvement of plunger pump, also comprise joint, described joint comprises fittings body, nut and oil pipe, described fittings body has hollow channel, described passage end is cone shape hole, described oil pipe also has hollow channel, the passage end of described oil pipe has the head of spheric, described head coordinates with cone shape hole, the inwall of described cone shape hole has the joint of a circle spheric, described head and joint form ball face sealing, and described nut is spun on fittings body, and prop up head, head and fittings body are closely cooperated.

Particularly, please refer to Fig. 6, this plunger pump comprises slippage pump 401, high low pressure distributing valve 402, oil suction screw 403, housing screw 404, outlet valve 405, oil sucting valve 406, trunk piston set assembly 407, wobbler shaft 408, thrust-bearing 409, plane bearing 410 (being also called end face bearing), housing 411, the pump housing 412, lip-type packing 413, lower end cap 414, low pressure relief valve 415, pipe joint 416 etc.

Oil suction screw 403 is installed on the pump housing 412 with thread forms, plays fastening nonreturn valve core and suction passage effect.Housing screw 404 is installed on the pump housing 412 with thread forms, plays fastening nonreturn valve core effect.Housing 411 connects with screw, and effect is the outer cover that support and the pump housing 412 seal.

Lip-shaped sealed ring 13 is installed in seal groove, and lip-type packing 413 is a kind of seal rings with self-tightening, and it relies on lip to be close to sealing male part surface, blocks leakage and obtains sealing effect.Lower end cap connects with screw, and effect is that formation one is sealed into oil pocket.Low pressure relief valve 415 is directly installed on oil suction chamber wall with screw thread

Please refer to Fig. 7, the assembly of trunk piston set shown in the present embodiment 407 comprises plunger body 4071, plunger bushing 4072 and plunger 4073, and plunger body 4071 has installation cavity and plunger hole.

Plunger 4073 and plunger bushing 4072 adopt special ceramic material to make, and plunger bushing 4072 has plunger cavity, and plunger bushing 4072 is fixed in the installation cavity of plunger body 4071, such as, hot-mounting process can be adopted to be fixed in installation cavity by plunger bushing 4072.

Plunger cavity is communicated with the plunger hole on plunger body 4071, and plunger 4073 one end is stretched in plunger cavity from plunger hole, and plunger 4073 and plunger cavity inwall form sliding pair, and adopt clearance seal, and clearance seal size is 0.001-0.012mm.

Plunger body 4071 is sealingly fastened on the pump housing 412, and plunger 4073, plunger body 4071, plunger bushing 4072 and the pump housing 412 enclose pump grease chamber, the locular wall of pump grease chamber has the hydraulic fluid port for passing in and out fluid.This hydraulic fluid port can be one, simultaneously as oil suction and fuel-displaced, is communicated with respectively at oil-absorbing pipeline by pipe joint 416 with flowline; Or also as shown in this embodiment, two hydraulic fluid ports can be set, be respectively inlet port and oil outlet.

Inlet port and oil outlet passage install the logical of one-way valve control channel respectively close.Oil sucting valve 406 and outlet valve 405, by press metal gasket in circle edge, can realize end face and side seals simultaneously, and do not need the sealings such as rubber, sealing reliably.And without the need to being processed as one with locking screw, structure is simple, greatly reduces the difficulty of processing of turnover fuel tap 405 body, improving its precision.The mounting type of this suction, outlet valve 405, sealing effect is guaranteed, and improves the working pressure class of plunger pump.

Driving mechanism coordinates with plunger 4073, and drive plunger 4073 moves back and forth, and changes the volume size of pump grease chamber.Driving mechanism comprises wobbler shaft 408 and plane bearing 410, and wobbler shaft 408 has the supporting surface of inclination, and plane bearing 410 is placed on supporting surface.Because supporting surface is obliquely installed, so plane bearing 410 is also obliquely installed thereupon, plane bearing 410 one end is rotated with wobbler shaft 408, and the other end does not rotate with wobbler shaft 408, and this end face do not rotated with wobbler shaft 408 props up plunger 4073.

Driven by motor wobbler shaft 4088 rotates, and wobbler shaft 408 is also provided with thrust-bearing 409 except supporting plane bearing 410, for bearing end thrust.One end face of plane bearing 410 rotates together with wobbler shaft 408, and other end is not rotated with wobbler shaft 408, but produces difference of height when wobbler shaft 408 rotates.This difference of height promotes plunger 4073 and completes to-and-fro motion, extrusion pump grease chamber.

Please continue to refer to Fig. 2, in the present embodiment, trunk piston set assembly 407 also comprises latch bracket 74 and spring 75, and latch bracket 74 has through hole.

Plunger 4073 comprises piston cap 4077 and plunger rod 4078, and plunger rod 4078 passes from through hole, and piston cap 4077 is stuck in latch bracket 4074 side, and spring 4075 is connected between latch bracket 4074 and plunger body 4071.

Plunger 4073, under wobbler shaft 408 rotates the effect of generation axial difference of height power and under the effect of spring 4075, completes to-and-fro motion.

Plane bearing 410 makes the fricting movement between existing piston cap 4077 and swash plate become piston cap 4077 only to bear the grinding pressure of plane bearing 410 and without relative friction forces, which greatly enhances pump shaft running efficiency and reduce wearing and tearing to piston cap 4077.

Also can increase by two bearings at axle head, replace original copper sheathing and coordinate, wobbler shaft 408 be felt relieved and is ensured, reduce the noise of plunger pump and improve the operating life of plunger pump.

The present embodiment high-pressure reversing valve 302, for can be applicable to the selector valve of more than 40MPa hydraulic system, also provides two kinds of solenoid directional control valves as high-pressure reversing valve 302 here simultaneously.

Certainly, other selector valves that can be applicable to more than 40MPa hydraulic system also can be selected to replace solenoid directional control valve shown in this example.

First this example solenoid directional control valve provides a kind of valve auxiliary structure, comprise spool, also comprise valve pocket, described valve pocket has valve pocket chamber, described valve pocket chamber wall offers valve pocket filler opening, at least one valve pocket actuator port and valve pocket return opening, described spool is loaded in valve pocket chamber, described spool and described valve pocket form sliding pair and clearance seal, be communicated with valve pocket filler opening or valve pocket return opening with the valve pocket actuator port controlling to specify, described valve pocket and spool all adopt special ceramic material to make, and described gap sealed gap length is 0.001-0.008mm.

This example solenoid directional control valve, comprise valve body, spool and electromagnet assembly, described valve body has valve body chamber, the internal chamber wall in described valve body chamber has valve body filler opening, at least one valve body actuator port and valve pocket return opening, also comprise valve pocket, described valve pocket is fixedly installed in valve body chamber, described valve pocket has valve pocket chamber, described valve pocket chamber wall offers valve pocket filler opening, at least one valve pocket actuator port and valve pocket return opening, described valve pocket actuator port is communicated with valve body actuator port, described valve pocket filler opening is communicated with valve body filler opening, described valve pocket return opening is communicated with valve body return opening, described spool is loaded in valve pocket chamber, described spool and described valve pocket form sliding pair and clearance seal, be communicated with valve pocket filler opening or valve pocket return opening with the valve pocket actuator port controlling to specify, described valve pocket and spool all adopt special ceramic material to make, described gap sealed gap length is 0.001-0.008mm.

As the further improvement of above valve auxiliary structure and solenoid directional control valve, described gap sealed gap length is 0.002-0.005mm.

As the further improvement of above valve auxiliary structure and solenoid directional control valve, described gap sealed gap length is 0.003-0.004mm.

As the further improvement of above valve auxiliary structure and solenoid directional control valve, the outer surface of described valve pocket arranges at least one ring annular groove.

As the further improvement of above valve auxiliary structure and solenoid directional control valve, the diameter span of valve pocket filler opening, valve pocket actuator port and valve pocket return opening is 6.5-20mm.

Particularly, as seen in figs. 8-10, the first example solenoid directional control valve comprises valve body 501, valve pocket 502, spool 503 and electromagnet assembly 504.

Wherein, valve pocket 502 and spool 503 form a kind of valve auxiliary structure.

This valve auxiliary structure comprises valve pocket 502 and spool 503.

This valve pocket 502 has valve pocket chamber 5021, valve pocket chamber 5021 wall offers valve pocket oil inlet P 1, two valve pocket actuator ports A1, B1 (actuator port can be more than one, and the present embodiment is two) and valve pocket oil return inlet T.This spool 503 is loaded in valve pocket chamber 5021.Spool 503 surface coordinates with the inner wall sealing in valve pocket chamber 5021 and forms sliding pair, in sliding process, by the outer surface of spool 503, valve pocket oil inlet P 1 is communicated with the valve pocket actuator port of specifying, as valve pocket oil inlet P 1 is communicated with actuator port A1, actuator port B1 and valve pocket oil inlet P 1 disconnect, and actuator port B1 is communicated with valve pocket oil return inlet T; Or valve pocket oil inlet P 1 is closed with actuator port B1 connected sum, actuator port A1 and valve pocket oil inlet P 1 disconnect, and actuator port A1 is communicated with valve pocket oil return inlet T.

Please continue to refer to Fig. 8, valve body 501 has valve body chamber, and the internal chamber wall in valve body chamber has valve body oil inlet P 2, valve body actuator port A2, B2 and valve body return opening (not shown).In valve auxiliary structure, valve pocket 502 is fixedly embedded in valve body chamber, and valve pocket oil inlet P 1 is communicated with valve body oil inlet P 2, and valve pocket actuator port A1 is communicated with valve body actuator port A2, and valve pocket actuator port B1 is communicated with valve body actuator port B2.

Electromagnet assembly comprises electromagnet 504, liftout mechanism 505 and joint 506 etc., this electromagnet 504 acts on spool 503 by liftout mechanism 505, spool 503 is slided in valve pocket chamber 5021, be communicated with or close each hydraulic fluid port, thus the commutation of hydraulic control executive component (as hydraulic rod, oil hydraulic motor) or start and stop, namely utilize the switching of electromagnet 504 electricity and directly promote the connected state valve that spool 503 carrys out control port.Below just sketch the control procedure of this electromagnet assembly, in fact to control the Principle of Process of spool 503 identical with existing solenoid directional control valve for this electromagnet assembly, here with regard to no longer superfluous words.

Valve pocket 502 is fixedly inlayed to adopt with the internal chamber wall in valve body chamber and is tightly fixed, specific operation valve body 501 and valve pocket 502 can be heated, at a certain temperature valve pocket 502 is embedded in the valve body chamber of valve body 501, cool the latter two and realize drive fit mosaic structure.

In order to strengthen the fixing of valve pocket 502 and valve body, the outer surface of valve pocket 502 can arrange at least one ring annular groove 5022.

In the present embodiment, valve pocket 502 and spool 503 all adopt special ceramic material (being also called special cermacis, fine ceramics) to make, and valve pocket 502 and being sealed and matched of spool 503 refer between spool 503 and valve pocket 502 to be clearance seal.

The annular groove 5031 of some radial directions is provided with outside spool 503.

Wherein, gap sealed gap length can be 0.001-0.008mm, and wherein 0.001mm gap is applicable to the solenoid directional control valve of below 200Mpa, and 0.008mm gap is applicable to the solenoid directional control valve of below 50Mpa.

Or gap sealed gap length can be 0.002-0.005mm, and wherein 0.002mm gap is applicable to the solenoid directional control valve of below 150Mpa, and 0.005mm gap is applicable to the solenoid directional control valve of below 70Mpa.

Or gap sealed gap length can be 0.003-0.004mm, and wherein 0.003mm gap is applicable to the solenoid directional control valve of below 120Mpa, and 0.004mm gap is applicable to the solenoid directional control valve of below 100Mpa.

The present embodiment adopt special ceramic material to have excellent engineering properties, less than 120 DEG C expansions are zero substantially, can ensure that the clearance seal effect of valve auxiliary structure is by the impact that spool 503 expands.And the abrasion resistance of special ceramic material, life-span, hardness, density, the relatively existing metallic material of pressure withstanding degree have and significantly improve, the technical requirements of more than 40MPa hydraulic system can be met.

Meanwhile, because special ceramic material has good self lubricity, it can be applied to various flowing medium, also because its good corrosion stability, can be widely applied in the corrosive atmospheres such as acid-alkali salt, as fields such as ocean, chemical industry, oil.

And in the present embodiment, because valve pair adopts clearance seal, sealing material that therefore completely can be other, directly utilizes the micro-gap between movement parts to seal.Because of need not any sealing material, so valve auxiliary structure is simply compact, size be little.And owing to having gap to exist between proportioning valve pair, so the frictional force of valve auxiliary structure is little, heating is few, and the life-span is long.

And the secondary heatproof of valve that special ceramic material is made is very high, can use in hot environment.

This special ceramic material has lower performance of expanding with heat and contract with cold, higher consistency and elasticity modulus, thus process heat expansion distortion and cold plasticity all less.So list can reach clearance seal permissible accuracy, also help and detect and superfinishing size Control online cooperation, the wildcard of spool 503 and valve pocket 502 can be accomplished.Prior art spool 503 and valve body are by being processed into grinding, therefore a spool 503 can only join a valve body, and the auxiliary structure of valve shown in the present embodiment, spool 503 can with any one valve pocket 502 with the use of, valve pocket 502 also can with any one spool 503 with the use of, be convenient to change component, be applicable to batch production.

The solenoid directional control valve that the relative existing metal valve pair of the performance index such as the commutation ability of the present embodiment solenoid directional control valve, the pressure loss, interior amount of leakage, commutation and resetting time, commutating frequency, working life is made has obvious lifting, can realize completely in the high pressure of more than 40MPa, high pressure and the normal use surpassing the second tunnel hydraulic system.

Please refer to Figure 11-13, the second example solenoid directional control valve is large footpath selector valve, and it comprises valve body 511, valve pocket 512, spool 513 and electromagnet assembly, and wherein valve pocket 512 and spool 513 all adopt special ceramic material to make, and forms a pair valve auxiliary structure.

Please refer to Figure 12, valve auxiliary structure comprises valve pocket 512 and spool 513, and this valve pocket 512 has valve pocket chamber 5121, valve pocket chamber 5121 wall offers valve pocket oil inlet P 1, two valve pocket actuator port A1, B1 and valve pocket oil return inlet T.This spool 513 is loaded in valve pocket chamber 5121.Spool 513 surface coordinates with the inner wall sealing in valve pocket chamber 5121 and forms sliding pair, in sliding process, by the outer surface of spool 513, valve pocket oil inlet P 1 is communicated with the valve pocket actuator port of specifying, as valve pocket oil inlet P 1 is communicated with actuator port A1, actuator port B1 and valve pocket oil inlet P 1 disconnect, and actuator port B1 is communicated with valve pocket oil return inlet T; Or valve pocket oil inlet P 1 is closed with actuator port B1 connected sum, actuator port A1 and valve pocket oil inlet P 1 disconnect, and actuator port A1 is communicated with valve pocket oil return inlet T.

Wherein, the present embodiment valve pocket 512 and spool 513 all adopt special ceramic material (being also called special cermacis, fine ceramics) to make, and valve pocket 512 and being sealed and matched of spool 513 refer between spool 513 and valve pocket 512 to be clearance seal.The latus rectum span of the valve pocket filler opening of the present embodiment, valve pocket actuator port and valve pocket return opening is 6.5-20mm, as latus rectum get 6.5,10,20mm etc.Gap sealed gap length is 0.003-0.009mm.

About choosing of hydraulic fluid port latus rectum and gap length, provide several groups of examples here:

1, the latus rectum of valve pocket filler opening, valve pocket actuator port and valve pocket return opening is 10mm, gap sealed gap length is 0.003-0.006mm, such as 0.005mm, wherein 0.003mm gap is applicable to the solenoid directional control valve of below 120Mpa, 0.005mm gap is applicable to the solenoid directional control valve of below 100Mpa, and 0.006mm gap is applicable to the solenoid directional control valve of below 70Mpa.

2, the latus rectum of valve pocket filler opening, valve pocket actuator port and valve pocket return opening is 20mm, gap sealed gap length is 0.005-0.009mm, wherein 0.005mm gap is applicable to the solenoid directional control valve of below 100Mpa, and 0.009mm gap is applicable to the solenoid directional control valve of below 50Mpa.

3, the latus rectum of valve pocket filler opening, valve pocket actuator port and valve pocket return opening is 20mm, and gap sealed gap length is 0.006-0.007mm, and wherein 0.007mm gap is applicable to the solenoid directional control valve of below 70Mpa.

The special ceramic material abrasion resistance adopted in the present embodiment, life-span, hardness, density, pressure withstanding degree all significantly improve, there are good self lubricity and corrosion stability, simultaneously due to performance of expanding with heat and contract with cold, higher consistency and elasticity modulus that special ceramic material is less, thus process heat expansion distortion and cold plasticity all less, therefore can apply to latus rectum and be greater than solenoid directional control valve, reach seal request.

Because spy's valve pair of making pottery can reach clearance seal permissible accuracy, sealing material that therefore completely can be other, directly utilizes the micro-gap between movement parts to seal.And owing to having gap to exist between proportioning valve pair, so frictional force is little, heating is few, and the life-span is long.And need not any sealing material, so special pottery valve auxiliary structure is simply compact, size is little.

And the spy to be made up of this special ceramic material secondary heatproof of valve of making pottery is very high, can use in hot environment.Because special ceramic material has good self lubricity, it can be used for various flowing medium, also because its good corrosion stability, can be widely applied in the corrosive atmospheres such as acid-alkali salt, as fields such as ocean, chemical industry, oil.

The performance of expanding with heat and contract with cold that this special ceramic material is less, higher consistency and elasticity modulus, thus process heat expansion distortion and cold plasticity all less.So list can reach clearance seal permissible accuracy, also help and detect and superfinishing size Control online cooperation, the wildcard of spool and valve pocket can be accomplished, be convenient to change component, applicable batch production.

Please continue to refer to Figure 11, valve body 511 has valve body chamber, and the internal chamber wall in valve body chamber has valve body oil inlet P 2, valve body actuator port A2, B2 and valve body return opening (not shown).In valve auxiliary structure, valve pocket 512 is fixedly embedded in valve body chamber, valve pocket oil inlet P 1 is communicated with valve body oil inlet P 2, valve pocket actuator port A1 is communicated with valve body actuator port A2, valve pocket actuator port B1 is communicated with valve body actuator port B2, wherein, valve pocket oil inlet P 1, two valve pocket actuator port A1, B1 and valve pocket oil return inlet T are adaptive with valve body oil inlet P 2, valve body actuator port A2, B2 and valve body return opening latus rectum size respectively.

This electromagnet assembly is divided into the first electromagnet assembly and the second electromagnet assembly, and this first electromagnet assembly comprises electromagnet 5141, coil (not shown), plug 5161, liftout mechanism and spring.This second electromagnet assembly comprises electromagnet 5142, coil (not shown), plug 5162, liftout mechanism and spring.

Electromagnet acts on spool 513 by liftout mechanism, spool 513 is slided in valve pocket chamber 5121, is communicated with or closes each hydraulic fluid port, thus the commutation of hydraulic control executive component (as hydraulic rod, oil hydraulic motor) or start and stop.Namely utilize the switching of electromagnet electricity and directly promote connected state that spool 513 carrys out control port and namely utilize electromagnetic attraction to handle spool 513 to replace the control valve in direction.Below just sketch the control procedure of this electromagnet assembly, in fact to control the Principle of Process of spool identical with existing solenoid directional control valve for this electromagnet assembly, here with regard to no longer superfluous words.

Valve pocket 512 is fixedly inlayed to adopt with the internal chamber wall in valve body chamber and is tightly fixed, specific operation are heated valve body 511 and valve pocket 512, at a certain temperature valve pocket 512 is embedded in the valve body chamber of valve body 511, cool the latter two and realize drive fit mosaic structure.

In order to strengthen the fixing of valve pocket 512 and valve body, the outer surface of valve pocket 512 can arrange at least one ring annular groove.

As shown in figure 13, the shaft shoulder 5231 of spool 513 also has balancing slit 5232, the quantity of balancing slit is 0.75-1.25 times of balancing slit quantity on existing conventional latus rectum solenoid directional control valve, such as, be 5 ~ 7.Wide 0.1 ~ the 0.3mm of balancing slit, such as 0.2mm are 1.0 ~ 1.5mm deeply.The object arranging balancing slit 5232 is the uniform property of its radial pressure of reinforcement, reduces flowed friction, increases its centering and reduce and leak.

Due to the excellent engineering properties of this extraordinary special ceramic material, less than 120 DEG C expansions are that zero sealing is unaffected substantially, and extraordinary special ceramic material, its abrasion resistance, life-span, hardness, density, pressure withstanding degree all significantly improve, and can meet the technical need of more than 40MPa hydraulic system solenoid directional control valve.

The present embodiment mesohigh relief valve 303, for can be applicable to the relief valve of more than 40MPa hydraulic system, also provides five kinds of relief valves as high-pressure overflow valve 303 here simultaneously.

Certainly, other relief valves that can be applicable to more than 40MPa hydraulic system also can be selected to replace relief valve shown in this example.

This example relief valve, comprising:

Valve body, described valve body has valve body chamber, and the chamber wall in described valve body chamber is provided with filler opening and flow-off;

Valve pocket, described valve body cover is fixed on valve body, and described valve body cover has valve pocket chamber, and described valve pocket chamber communicates with valve body chamber;

And elastic component;

Also comprise:

Plunger bushing, described plunger bushing is fixed in valve body chamber, and its sidewall has oil outlet, and described oil outlet communicates with flow-off;

Plunger, described plunger slides and is arranged in plunger bushing, and described plunger bushing and plunger are special ceramic material makes, and adopts clearance seal between the two;

Described plunger at one end communicates with filler opening, and the other end stretches in valve pocket chamber, and described elastic component acts on one end that plunger stretches into valve pocket chamber, and its elastic force makes plunger move to filler opening.

Or another kind of relief valve, comprising:

Valve body, described valve body has valve body chamber, and the chamber wall in valve body chamber has filler opening and flow-off;

Valve pocket, described valve pocket has valve pocket chamber, and described valve pocket is fixed on valve body, and valve pocket chamber is communicated with valve body chamber;

And elastic component;

Also comprise:

Sealing seat, described sealing seat is fixed in valve body chamber, and described sealing seat has flow channels, and described flow channels is communicated with oil outlet with filler opening;

Ball sealer, described ball sealer is that special ceramic material is made, described flow channels has one section of conical bore, the conduit wall of described conical bore has the groove of a circle spheric, the groove of described ball sealer and described spheric seals fits, described elastic component acts on ball sealer, resets for making ball sealer.

As the further improvement of described another kind of relief valve, described sealing seat is that alloy steel material is made.

As the further improvement of described another kind of relief valve, connecting passage is provided with between described filler opening and oil outlet, described connecting passage is equipped with off-load ball sealer, described connecting passage has one section of conical bore, the hole wall of described conical bore has a circle spheric groove, described off-load ball sealer is that special ceramic material is made, and the spheric groove in described off-load ball sealer and off-load flow channels is fitted, to seal up off-load oil outlet;

Also comprise drive unit, described drive unit coordinates with off-load ball sealer, off-load ball sealer can be driven to move, to open or close connecting passage.

As the further improvement of described another kind of relief valve, described drive unit is solenoid valve, also comprises push rod, and described valve body has sliding cavity, and described solenoid-driven push rod slides in sliding cavity, and promotes off-load ball sealer.

As the further improvement of described another kind of relief valve, described valve body also has accessory channel, and described accessory channel one end is communicated with filler opening, and the other end is communicated with push rod place sliding cavity, to utilize oil pressure auxiliary pushing ball sealer.

As the further improvement of described another kind of relief valve, also comprise the control port for connecing oil circuit control, described control port is communicated with sliding cavity, to promote the opening and closing that push rod controls off-load oil outlet.

Or another relief valve, comprising:

Main valve, described main valve comprises main valve body, primary seal seat and primary seal ball, and described sealing seat is arranged on main valve body, and described ball sealer coordinates with the flow channels of sealing seat and realizes sealing;

Pilot valve, described pilot valve structure comprises guide valve blocks, guide's sealing seat and guide's ball sealer, and described guide's sealing seat is fixed in pilot valve, and described guide's ball sealer coordinates with the flow channels of guide's sealing seat and realizes sealing;

Described main valve has filler opening, oil outlet and damping hole, and described filler opening is communicated with pilot valve by damping hole, by being communicated with and closedown of filler opening on described pilot valve control bound and oil outlet;

Described primary seal ball and guide's ball sealer all adopt special ceramic material to make, the conduit wall of the flow channels of described primary seal seat and guide's sealing seat has respectively one section of conical bore, the conduit wall of described conical bore has the groove of a circle spheric, and described primary seal ball and guide's ball sealer are fitted respectively at sealing with corresponding spheric groove.

Improve further as another relief valve described, described primary seal seat and/or guide's sealing seat are that alloy steel material is made.

Improve further as another relief valve described, also comprise solenoid valve, described solenoid valve one end coordinates with guide's ball sealer, to promote the opened circulation road of described ball sealer.

Particularly, please refer to Figure 14, the first example relief valve is specially the board-like direct acting relief valve of trunk piston set.

This relief valve comprises valve body 601, valve pocket 602, plunger bushing 603, seal ring 604, plunger 605, compact heap 606, piston cap 607 and elastic component.

This valve body 601 has valve body chamber, and the chamber wall in valve body chamber is provided with filler opening 6011 and flow-off 6012, and filler opening 6011 enters for hydraulic oil, and flow-off 6012 communicates with fuel tank, and hydraulic oil can flow back to fuel tank since then.

Plunger bushing 603 is fixed in valve body chamber, such as hot charging on the cylindrical hole of valve body 601 inner chamber, without additional seal.Also plunger bushing 603 can be assemblied in valve body 601 by simple transition fit, install seal ring 604 additional in plunger bushing 603 bottom and seal.

The sidewall of plunger bushing 603 has oil outlet 6031, and this oil outlet 6031 communicates with flow-off 6012, and it can be the radial hole being opened in plunger bushing 603 sidewall.

Compact heap 606 is pressed in the upper end of plunger bushing 603, and valve body 601 overlaps to be screwed on valve body 601, for compressing compact heap 606 and plunger bushing 603, is also fixedly connected with valve body 601 simultaneously.This valve pocket 602 has valve pocket chamber, and this valve pocket chamber communicates with valve body chamber.

This plunger 605 slides and is arranged in plunger bushing 603, and its one end communicates with filler opening 6011, and the other end stretches in valve pocket chamber.Wherein plunger 605 and plunger bushing 603 are special ceramic material (special ceramic material) and make, and adopt clearance seal between the two.

Piston cap 607 is loaded in plunger 605 upper end and valve pocket 602 in cylindrical cavity, for bearing plunger 605 up-downgoing power, and removes suspension and leading role.

This elastic component acts on one end that plunger 605 stretches into valve pocket chamber, and its elastic force makes plunger 605 move to filler opening 6011.

In the present embodiment, elastic component comprises spring 608, adjusting screw rod 609, steel ball 610 and spring seat 611, and this adjusting screw rod 609 adjustable ground is arranged on valve pocket 602, and such as adjusting screw rod 609 has upper and lower two nuts, upper cap nut is used for regulating, and lower nut is used for locking.

Spring seat 611 equally plays guiding, and have spheric pit at spring seat 611 towards the one side of adjusting screw rod 609, this steel ball 610 is arranged in pit, transmits the pretightening force of adjusting screw rod 609, ensures that transmitting force puts on the center of spring seat 611.

The present embodiment working principle is as follows:

Filler opening 6011 oil-feed of valve body 601, directly communicates with plunger 605 lower end surface, and when the pressure of hydraulic oil is less than need of work pressure, plunger 605 is pressed in the bottom of plunger bushing 603 by spring 608, is in closed state between filler opening 6011 and flow-off 6012.

When the pressure of hydraulic oil exceed its work authorized pressure be namely greater than spring 608 set pressure time, plunger 605 by hydraulic oil upwardly, when plunger 605 lower end surface displacement exceedes the oil outlet 6031 that plunger bushing 603 sidewall is offered, hydraulic oil flows into the flow-off 6012 connected with oil outlet 6031, and hydraulic oil flows back to fuel tank.

The pressure of hydraulic oil is larger, and plunger 605 must be higher by hydraulic oil jack-up, and the flow that hydraulic oil flows back to fuel tank through relief valve is larger.If the pressure of hydraulic oil is less than or equal to spring 608 set pressure, then plunger 605 is descending, seals flow-off 6012.

The present embodiment makes trunk piston set structure owing to adopting special ceramic material (special ceramic material), its matching gap between 0.002-0.009mm, such as 0.002-0.004mm.Because special ceramic material (special ceramic material) has excellent engineering properties, less than 120 DEG C expansions are zero substantially, the impact that clearance seal effect is not expanded can be ensured, gap sealed stability can be ensured, therefore not only can be applicable to the hydraulic system 300 of below 100MPa, also can be applicable to be greater than in the hydraulic system 300 of 100MPa, as 250MPa, 1100MPa etc.

And without Sealing, can simplify overall structure between the present embodiment trunk piston set, and the problems such as Sealing damage need not be considered.

In addition, special pottery trunk piston set has good damping function, can not produce pulsation, so not only opening and closing simultaneously flexible but also move smooth-going stable.The sliding pair of special Tao Zhusai is the accurate motion of high alignment, this relief valve entirety too much free parts, so avoid prior art relief valve because of spool radial direction clamping, poppet valve core, steel ball parts are free, bad seals, the noise that the reasons such as spool wearing and tearing cause, vibration and pressure regulation Its Failures.

Please refer to Figure 15,16, the second example relief valve is specially board-like direct acting relief valve.

This relief valve comprises valve body 621, valve pocket 622, sealing seat 623, ball sealer 624, damping piston 625, latch bracket 626 and elastic component.

This valve body 621 has valve body chamber, and the chamber wall in valve body chamber has filler opening 6211 and flow-off 6212.Filler opening 6211 enters for hydraulic oil, and flow-off 6212 communicates with fuel tank, and hydraulic oil can flow back to fuel tank since then.

This valve pocket 622 is fixed on valve body 621, and it has valve pocket chamber, and this valve pocket chamber communicates with valve body chamber.

Sealing seat 623 is fixed in valve body chamber, and such as screw thread is fixed.Sealing seat 623 has flow channels 6231, and filler opening 6211 is communicated with flow-off 6212 by this flow channels 6231.

Ball sealer 624 adopts special ceramic material (special ceramic material) to make, and obtains as adopted zirconium oxide or silicon nitride.Sealing seat 623 can select difference of hardness to make in the alloyed steel of special ceramic material (special ceramic material).

Please refer to Fig. 3, flow channels 6231 has one section of conical bore 6232, and the hole wall of this conical bore 6232 has the groove 6233 of a circle spheric, and ball sealer 624 seals with the groove 6233 of this spheric and fits.

Elastic component acts on ball sealer 624, resets for making ball sealer 624.

In the present embodiment, elastic component comprises spring 627, adjusting screw rod 628, spring seat 629 and steel ball 630, and this adjusting screw rod 628 adjustable ground is arranged on valve pocket 622, and such as adjusting screw rod 628 can be spirally connected with valve pocket 622.

Spring seat 629 play the guiding role, and have spheric pit at spring seat 629 towards the one side of adjusting screw rod 628, this steel ball 630 is arranged in pit, transmits the pretightening force of adjusting screw rod 628, ensures that transmitting force puts on the center of spring seat 629.

This damping piston 625 is arranged at ball sealer 624 oil-feed side, rise lift special pottery ball 624 and ensure the motion of special pottery ball, float, opening and closing is smooth-going.

The present embodiment working principle is as follows:

Filler opening 6211 oil-feed of valve body 621, acts on ball sealer 624, and when the pressure of hydraulic oil is less than need of work pressure, ball sealer 624 is pressed on sealing seat 623 by spring 627, is in closed state between filler opening 6211 and flow-off 6212.

When the pressure of hydraulic oil exceed its work authorized pressure be namely greater than spring 627 set pressure time, ball sealer 624 is pushed away sealing seat 623 by hydraulic oil, and hydraulic oil flows into the flow-off 6212 connected with fuel tank, and hydraulic oil flows back to fuel tank.

The alloy steel material that sealing seat 623 can adopt hardenability good makes, and according to different flow channels 6231 diameter, sphere diameter, flow velocity, pressure, processes the conical bore of a selected angle in sealing seat 623 flow channels 6231 front end.

And the spheric groove on conical bore utilizes ball sealer 624 to extrude conical bore until the method reaching sealing seat 623 material flow pressure is formed.Certainly, also complete by other machining modes.

The present embodiment is owing to have employed ball face sealing pair, and sealing grade is very high, and sealing effect is reliable, not only can be applicable to the hydraulic system 300 of below 100MPa, also can be applicable to be greater than in the hydraulic system 300 of 100MPa, as 250MPa, 1100MPa etc.

In addition, special pottery ball and alloyed steel sealing seat sealing pair have good hydraulic oil motion streamline type size, not easily produce turbulent flow, so not only opening and closing simultaneously flexible but also move smooth-going, huge difference of hardness between special pottery ball and alloyed steel sealing seat, the feature of special pottery ball highi degree of accuracy high finishingness, and special pottery ball and sealing seat form the dimensional height stability of sealing pair, so avoid prior art relief valve because of spool radial direction clamping, cross head piece turbulent flow, poppet valve core, steel ball components hit is worn and torn, sealing surface damages, the noise that the reasons such as spool wearing and tearing cause, vibration and pressure regulation Its Failures.

Please refer to Figure 17, the third example relief valve is specially a kind of board-like pilot-type relief valve.

This relief valve comprises main valve and pilot valve.

Main valve comprises main valve body 641, primary seal seat 642 and primary seal ball 643.

Main valve body 641 has valve body chamber, and valve body chamber has filler opening 6411 (i.e. P mouth), flow-off 6412 (i.e. T mouth).Filler opening 6411 enters for hydraulic oil, and flow-off 6412 communicates with fuel tank, and hydraulic oil can flow back to fuel tank since then.

Primary seal seat 642 is fixed in valve body chamber, and the flow channels of primary seal seat 642 has one section of conical bore, and the hole wall of this conical bore has the groove of a circle spheric.Primary seal ball 643 seals with the spheric groove of primary seal seat 642 and fits.

Pilot valve comprises guide valve blocks 646, guide's sealing seat 647 and guide's ball sealer 648, guide's sealing seat 647 is fixed on guide valve blocks 646, wherein the flow channels of guide's sealing seat 647 has one section of conical bore, and equally, the hole wall of this conical bore has the groove of a circle spheric.

Conical bore on this primary seal seat and guide's sealing seat and spheric groove structure can with reference to the conical bore shown in above-mentioned the second relief valve and spheric groove structures.

Primary seal ball 643 and guide's ball sealer 648 all adopt special ceramic material (special ceramic material) to make, and obtain as adopted zirconium oxide or silicon nitride.Primary seal seat 642 and guide's sealing seat 647 can select difference of hardness to make in the alloyed steel of special ceramic material (special ceramic material).

And the spheric groove on conical bore utilizes ball sealer to extrude conical bore until the method reaching sealing seat material flow pressure is formed.Certainly, also complete by other machining modes.

Filler opening on main valve 6411 is communicated with pilot valve by damping hole a, by being communicated with and closedown of filler opening 6411 on pilot valve control bound and flow-off 6412.

Guide's ball sealer 648 is provided with guide piston 649 (double do latch bracket) and elastic component, this elastic component comprises spring 650, adjustable lever 651, spring seat 652, steel ball (not shown) and handle 653, in order to regulate the pressure at pilot valve place.

The working principle of relief valve shown in the present embodiment is as follows:

Filler opening 6411 bottom the autonomous valve body 641 of pressure oil enters, and act on pilot valve spy pottery ball 648 by damping hole a, b, the aperture c of guide's sealing seat 647 passes into main valve plug (main valve plug comprises primary seal ball 643 and spring seat 34) epicoele simultaneously, and pressure oil also enters main valve plug cavity of resorption by the aperture e on primary seal seat 642.When the pressure p 1 of filler opening 6411 is less than the setting of pilot valve pressure adjusting spring 650, pilot valve is closed, and to be designed to upside slightly large due to main valve plug upper and lower both sides useful area ratio, the active force acting on pressure difference on main valve plug and main spool spring 645 all makes primary valve close tightly, not overflow.

When input pressure exceedes the set pressure of pilot valve, pilot valve is opened, and causes and flows with the aperture d lower portion flow-off 6412 on the right side of main valve body 641 through damping hole a, poppet port, guide valve blocks 646 from filler opening 6411.The flow losses at damping hole a place make the fluid in the upper and lower chamber of main valve plug produce one to be increased and the pressure difference of increase with pilot valve flow, when the total pressure difference that it produces on the upper and lower acting surface of main valve plug be enough to overcome the power of main spool spring 645, main valve deadweight and frictional force time, main valve plug is opened.Now filler opening 6411 directly communicates with flow-off 6412, forms overflow with keeping system pressure.

When primary valve is closed, aperture e on primary seal seat 642 does not communicate with flow-off 6412, namely now pressure oil only enters main valve plug cavity of resorption, and the effect of this aperture e is the impact regulating main valve plug upper and lower both sides useful area ratio and absorb liquid stream when main valve plug is opened.

When this relief valve pilot valve, main valve are successively opened, realize overflowing liquid pressing system 300 pressure to be kept, when P oral fluid oil pressure p1 is less than the setting of pilot valve pressure adjusting spring 650 again, two groups of special pottery balls are at pilot valve pressure adjusting spring 650, under pressure difference on main valve plug and main spool spring 645 promote, under in pilot valve and the axial power of main valve plug guide piston and spool, the recessed water hole of ball controls, precisely move along axis to sealing seat 623 conical bore two sphere ring faces, relief valve cuts out again.

Because pilot-type relief valve main spool spring 645 is mainly used in the frictional force overcoming spool, spring 35 rigidity is little.When spillway discharge change causes main spool spring 645 decrement to change, spring force change is less, and therefore the change of valve inlet pressure is also less.Regulation precision is high, is widely used in high pressure, Mass flow system.

This advanced in technology type high-pressure overflow valve 303 mainly have employed the secondary core technology of two groups of ball face sealings, and sealing effect is very reliable, bears pressure huge, opens closed flexible smooth-going stable.According to pressure rating, latus rectum, give with the pre-applied force of sealing seat conical bore by increase and decrease, adjust alloyed steel sealing seat material, improve special ball precision degree of finish of making pottery, change special ball material etc. of making pottery, not only can be applicable to the hydraulic system 300 of below 100MPa, also can be applicable to be greater than in the hydraulic system 300 of 100MPa, as 250MPa, 1100MPa etc.

Please refer to Figure 18, the 4th kind of example relief valve is specially a kind of electromagnetism direct acting relief valve.

This relief valve comprises valve body 661, valve pocket 662, sealing seat 663, ball sealer 664, elastic component and solenoid valve 673.

This valve body 661 has valve body chamber, and the connecting passage (not shown) that the chamber wall in valve body chamber has filler opening 6211 (i.e. P mouth), flow-off 6612 (i.e. T mouth) and is communicated with flow-off 6612 by filler opening 6211.Filler opening 6211 enters for hydraulic oil, and flow-off 6612 communicates with fuel tank, and hydraulic oil can flow back to fuel tank since then.

This valve pocket 662 is fixed on valve body 661, and it has valve pocket chamber, and this valve pocket chamber communicates with valve body chamber.

Sealing seat 663 is fixed in valve body chamber, and such as screw thread is fixed.Sealing seat 663 has flow channels, and this flow channels is communicated with flow-off 6612 with filler opening 6211.

Flow channels has one section of conical bore, and the conduit wall of this conical bore has the groove of a circle spheric, and ball sealer 664 seals with the groove of this spheric and fits.

The structure of this conical bore and spheric groove can with reference to the structure of conical bore shown in above-mentioned the second relief valve and spheric groove.

Ball sealer 664 adopts special ceramic material (special ceramic material) to make, and obtains as adopted zirconium oxide or silicon nitride.Sealing seat 663 can select difference of hardness to make in the alloyed steel of special ceramic material (special ceramic material).

And the spheric groove on conical bore utilizes ball sealer 664 to extrude conical bore until the method reaching sealing seat 663 material flow pressure is formed.Certainly, also complete by other machining modes.

Elastic component acts on ball sealer 664, resets for making ball sealer 664.

In the present embodiment, elastic component comprises spring 667, regulates spiral shell 668, spring seat 669 and steel ball 670, and this adjustment spiral shell 668 adjustable ground is arranged on valve pocket 662, such as, regulate spiral shell 668 can be spirally connected with valve pocket 662.

Spring seat 669 play the guiding role equally, and have spheric pit at spring seat 669 towards regulating the one side of spiral shell 668, this steel ball 670 is arranged in pit, transmits the pretightening force regulating spiral shell 668, ensures that transmitting force puts on the center of spring seat 669.

Ball sealer 664 oil-feed side is provided with damping piston 666, and for lifting the special ball motion of making pottery of spy's pottery ball 664 and guarantee, floating, opening and closing is smooth-going.

This connecting passage has one section of conical bore, conical bore is equipped with off-load ball sealer 671.

Particularly, this valve body 661 is made for alloyed steel, conical bore is located immediately on the conduit wall of connecting passage, the hole wall of this conical bore has a circle spheric groove, off-load ball sealer 671 is made for special ceramic material (special ceramic material), off-load ball sealer 671 is fitted with the spheric groove in off-load flow channels, to seal up off-load flow-off 6612.

Or, in other embodiments, conical bore also can not directly be opened on valve body 661, and set up off-load sealing seat, this off-load sealing seat set up adopts alloyed steel to make, and it has conical bore, and the hole wall of conical bore has a circle spheric groove, off-load ball sealer 671 and this spheric groove are fitted, to seal up off-load flow-off 6612.

This solenoid valve 673, as drive unit, coordinates with off-load ball sealer 671, off-load ball sealer 671 can be driven to move, to open or close connecting passage.

In the present embodiment, solenoid valve 673 is specially with the cooperation of off-load ball sealer 671: one end of solenoid valve 673 is connected a lever 675, and lever 675 is outer installs electromagnet fitting seat 674.Lever 675 the other end connects a push rod 676 by steel ball and push rod steel ball seat 677.Valve body 661 has sliding cavity, and this sliding cavity communicates with space, off-load ball sealer 671 place.Push rod 676 slides and is arranged in sliding cavity, and solenoid valve 673 drives push rod 676 to slide in sliding cavity, and promotes off-load ball sealer 671, opens connecting passage, filler opening 6211 is directly communicated with flow-off 6612, carries out overflow.

Further, valve body 661 can also have accessory channel a, and this accessory channel a one end is communicated with filler opening 6211, and the other end is communicated with push rod 676 place sliding cavity, to utilize oil pressure auxiliary push-rod 676 to promote ball sealer 664, alleviates the thrust needed for push rod 676.

In addition, can also comprise control port x, this control port x is communicated with sliding cavity, control port x can be connect oil circuit control, carrys out with fluid the opening and closing that auxiliary pushing push rod 676 controls off-load flow-off 6612.

In the embodiment of other relief valves, divided by solenoid 673 as outside drive unit, other drive units also can be utilized to open connecting passage to drive off-load ball sealer 671, as mainly utilized the oil liquid pressure in oil circuit control to make push rod 676 move, thus open connecting passage.

The alloy steel material that the conduit wall of sealing seat 663 and/or connecting passage can adopt hardenability good makes, according to different flow channels diameter, sphere diameter, flow velocity, pressure, process the conical bore of a selected angle in sealing seat 663 flow channels and/or connecting passage front end.

The present embodiment specific works principle is:

Pressure oil enters relief valve seat chamber by filler opening 6211, acts on ball sealer 664, and when system pressure is less than the preset pressure of pressure adjusting spring 667, relief valve cuts out, not overflow.When system pressure is greater than the preset pressure of pressure adjusting spring 667, relief valve is opened, and unnecessary hydraulic oil flows to flow-off 6612 through valve body 661 flow channels from filler opening 6211, relief valve overflow keeping system pressure stability.Now this relief valve is just equivalent to a direct acting relief valve.

When the artificial adjust system pressure of needs, start solenoid valve 673, electromagnet obtains electric, and in electromagnet, push rod is moved to the left, and promotes lever 675 upper end by steel ball 670, lever 675 lower end then promotes push rod 676 by steel ball 670, push rod 676 pushes off-load ball sealer 671 open, opens connecting passage, and filler opening 6211 and flow-off 6612 are connected, realize people for overflow, whether now overflow has nothing to do with the preset pressure of pressure adjusting spring 667.

The present embodiment is owing to adopting ball face sealing secondary between sealing seat and ball sealer and between off-load ball sealer and connecting passage, sealing grade is very high, sealing effect is reliable, not only can be applicable to the hydraulic system 300 of below 100MPa, also can be applicable to be greater than in the hydraulic system 300 of 100MPa, as 250MPa, 1100MPa etc.In addition, the sealing pair that special pottery ball and alloyed steel are formed has good hydraulic oil motion streamline type size, not easily produce turbulent flow, so not only opening and closing simultaneously flexible but also move smooth-going, huge difference of hardness between ball sealer and alloyed steel sealing seat, the feature of ball sealer highi degree of accuracy high finishingness, and ball sealer and sealing seat form the dimensional height stability of sealing pair, so avoid prior art relief valve because of spool radial direction clamping, cross head piece turbulent flow, poppet valve core, steel ball components hit is worn and torn, sealing surface damages, the noise that the reasons such as spool wearing and tearing cause, vibration and pressure regulation Its Failures.

Meanwhile, the present embodiment also can pass through the artificial regulating system pressure of drive unit as required, makes selection more, more flexible, can meet more demands.

5th kind of example relief valve is specially electromagnetic pilot relief valve.

The difference of this relief valve and precursor overflow valve shown in the third is, also comprise solenoid valve, this solenoid valve one end coordinates with guide's ball sealer, to promote the opened circulation road of guide's ball sealer on precursor overflow valve, thus realize artificial control pilot valve overflow, and then drive main valve overflow.

The concrete structure of solenoid-driven guide ball sealer movement can the concrete structure of electromagnetic valve off-load ball sealer shown in reference example.

Certainly, in other embodiments, also realize solenoid-driven guide ball sealer by other structures and move this purpose.

In the present embodiment, the liquid-filling valve with more than 40MPa to be applied by high-pressure liquid-filling valve 312, also provides four kinds of liquid-filling valves as high-pressure liquid-filling valve 312 here simultaneously.

Certainly, other liquid-filling valves that can be applicable to more than 40MPa hydraulic system also can be selected to replace liquid-filling valve shown in this example.

This example liquid-filling valve, comprising:

Also comprise:

Stuffing box gland, described stuffing box gland is fixed on valve component, and stuffing box gland has conical bore, and the hole wall of described conical bore has the groove of a circle spheric;

As the further improvement of described liquid-filling valve, described stuffing box gland is that alloy steel material is made.

As the further improvement of described liquid-filling valve, the flow amount of described spheric groove is 0.1-3mm.

Or another kind of liquid-filling valve, comprising:

Also comprise:

Plunger bushing, described plunger bushing is fixed in valve body chamber;

And seal, described seal slides to be arranged in plunger bushing and forms trunk piston set structure, and described seal and plunger bushing all adopt special ceramic material to make, and are clearance seal between described seal and plunger bushing.

As the further improvement of described another kind of liquid-filling valve, the clearance seal size of described trunk piston set is 0.001-0.012mm.

As the further improvement of described another kind of liquid-filling valve, the clearance seal size of described trunk piston set is 0.002-0.006mm.

As the further improvement of described another kind of liquid-filling valve, also comprise:

Control oil cylinder, described control oil cylinder is fixed on valve component;

And piston rod, described piston rod is arranged on and controls in oil cylinder, and its one end is connected with seal, and control oil cylinder is divided into upper oil cavitie and lower oil cavitie by described piston rod, and described upper oil cavitie and lower oil cavitie are all for being communicated with selector valve.

Piston rod, described piston rod is arranged on and controls in oil cylinder, and its one end is connected with seal, and control oil cylinder is divided into upper oil cavitie and lower oil cavitie by described piston rod, and described upper oil cavitie is used for being communicated with selector valve;

And elastic component, described elastic component is arranged at lower oil cavitie, resets for making piston rod.

Or a liquid-filling valve system, comprises the liquid-filling valve of control gear and above-mentioned any embodiment, and described control gear matches with the seal in liquid-filling valve, in order to control the movement of seal.

As the further improvement of described liquid-filling valve system, described control gear is selector valve.

Particularly, please refer to Figure 19,20, the first example liquid-filling valve comprises valve component 711, stuffing box gland 712, seal 713, control unit 714, coupling rod 715 and flange 716.

This valve component 711 comprises first component 7111, second component 7112, the 3rd parts 7113 and the 4th parts 7114.Valve component 711 has valve body chamber 7115, the chamber wall in valve body chamber 7115 has the first flow channels 7116 and the second flow channels 7117.Wherein the first flow channels 7116 is positioned at the side of valve component 711, it is equipped with flange 716, and for being communicated with fuel tank, and the second flow channels 7117 is positioned at the lower end of valve component 711, and it is communicated with master cylinder 103 rodless cavity.

Sealing cover 712 is fixedly arranged on first component 7111, and stuffing box gland 712 has the 3rd flow channels the 7121, three flow channels 7121 is communicated with valve body chamber 7115, first flow channels 7116 and the second flow channels 7117.In the present embodiment, stuffing box gland 712 is contained in the second flow channels 7117, in other embodiments, certainly also can be arranged on other positions of valve component 711.

Sealing body 713 is made up of special ceramic material (special ceramic material), and the inwall of its outer wall and the 3rd flow channels 7121 matches.Seal 713 and stuffing box gland 712 form one group of sealing pair structure.

Particularly, please refer to Figure 19 and 20, seal 713 has the outer wall 7131 of spheric, and the 3rd flow channels 7121 has conical bore, the hole wall 7122 of conical bore has the spheric groove 7123 matched with seal 713 outer wall, the spheric outer wall 7131 of seal 713 seals with spheric groove 7123 on stuffing box gland 712 fits, and forms ball face sealing.

Please refer to Figure 19, in the present embodiment, seal 713 has two parallel end faces, sidewall 7131 between these two end faces is spheric, namely be equivalent to the plane cutting be parallel to each other with two by the seal 713 of a sphere-like, the part be positioned in the middle of two planes is the seal 713 shown in the present embodiment.And in order to increase the thickness of seal 713, the also extended one section of round platform after spheric sidewall of seal 713 shown in the present embodiment.

The present embodiment, seal 713 adopts special ceramic material to make, and stuffing box gland 712 can adopt the softer alloy steel material of more special ceramic material to make, and both complement each other to form ball face sealing, can meet the requirement of strength of more than 45MPa hydraulic system 300.

In addition, stuffing box gland 712 also can adopt the softer material of other more special ceramic materials to make.

Meanwhile, the present embodiment provides a kind of method of the spheric groove manufactured on stuffing box gland 712:

The spheroid (highi degree of accuracy special the make pottery ball of such as 10G more than) consistent with seal spheric outer wall is adopted to extrude the hole wall of conical bore to apply super flow power, the hole wall of conical bore is formed the spheric groove 7123 matched with seal 713, the flow amount of this spheric groove is 0.1-3mm, such as 0.2-0.6mm.

Certainly, this spheric groove is also made by other machining modes.

Liquid-filling valve is opened by the negative pressure of vacuum that existing liquid-filling valve can rely on master hydraulic cylinder to be formed, and relies on the change of hydraulic main cylinder 103 pressure increase and coordinates spring-return power to close liquid-filling valve.

This liquid-filling valve can adopt existing mode to control, and in addition, also can set up control unit and be convenient to realize ACTIVE CONTROL.

Please continue to refer to Figure 19, control unit 714 comprises and controls oil cylinder 7141, is placed in and controls piston rod 7142 in oil cylinder 7141 and elastic component 7143, control oil cylinder 7141 is divided into upper oil cavitie 7144 and lower oil cavitie 7145 by piston rod 7142, this upper oil cavitie is used for being communicated with selector valve, such as, be communicated with by filler opening 7118.Elastic component 7143 is arranged in lower oil cavitie 7145.

Piston rod 7142 connects with seal 713, and under the control of selector valve and elastic component, hydrodynamic reciprocating sealing body 713, to open or to seal the 3rd flow channels 7121.

Piston rod 7142 is affixed with seal 713, drives seal 713 to move.

The affixed mode that the present embodiment adopts is that piston rod 7142 has bulb joint part 146, and set up a coupling rod 715, bulb joint part 7146 connects with coupling rod 715 simultaneously, and coupling rod 715 connects with seal 713.

The working procedure of liquid-filling valve shown in the present embodiment is as follows:

Stretched out (i.e. seal 713 present position in Figure 19) by selector valve 717 (can be such as the second low pressure selector valve 309 in the present embodiment) ACTIVE CONTROL piston rod 7142, seal 713 is separated with stuffing box gland 712, now sealing pair is opened, second flow channels 7117 is opened (at this moment the rodless cavity of hydraulic press master cylinder 103 is communicated with fuel tank), allow a large amount of fluid by the first flow channels 7116 and the second flow channels 7117, be back to fuel tank from master cylinder epicoele or from the quick topping up of fuel tank to master cylinder epicoele, meet the function requirement of hydraulic press skip forward/back.

When needs cut off, selector valve 717 coordinates elastic component 7143 control piston bar 7142 to retract, seal 713 is in position shown in 713a in Figure 19, seal 713 and stuffing box gland 712 are fitted this moment, second flow channels 7117 is closed, at this moment master cylinder epicoele and fuel tank cut off, and master cylinder epicoele has started straightening to working pressure, and hydraulic press enters compacting state.

The seal that liquid-filling valve shown in the present embodiment is made with special ceramic material and the stuffing box gland that alloyed steel is made are processed into sealing pair, so sealing is reliable, can reaches zero leakage, bear pressure very high.Meanwhile, Sealing can not used completely, make total compacter, easier for installation.

And in control, liquid-filling valve shown in the present embodiment is different from prior art liquid-filling valve working principle, liquid-filling valve is opened by the negative pressure of vacuum not relying on master hydraulic cylinder to be formed, hydraulic main cylinder 103 pressure increase is not relied on to change and close high-pressure liquid-filling valve 312, can completely without spring, initiatively realized the opening and closing of sealing configuration by control unit, drive liquid-filling valve work by demand ACTIVE CONTROL completely.

Control unit uses buffer structure, compact overall structure, the feature such as easy for installation, thus compensate for prior art liquid-filling valve Frequent Troubles completely, maintenance cost is high, overcome and cause pressure release as oppositely poorly sealed, or the hydraulic shock Universal Problems affecting the normal use of hydraulic system 300 and main frame such as excessive when opening.

The more existing liquid-filling valve of liquid-filling valve shown in the present embodiment, reaction velocity is faster, opening and closing more flexibly and fast, reliability is higher, action is more secure, the requirement of strength of below 45MPa hydraulic system 300 can not only be met, also can meet the requirement of strength being greater than 45MPa hydraulic system 300, the hydraulic system 300 of such as 70-200MPa.

Please refer to Figure 21, the second example liquid-filling valve comprises valve component 721, stuffing box gland 722, seal 723, control unit 724, coupling rod 725 and flange 726.

This valve component 721 comprises first component 7211 and second component 7212, valve component 721 has valve body chamber 7213, the chamber wall in valve body chamber 7213 has the first flow channels 7214 and the second flow channels 7215.Wherein the first flow channels 7214 is positioned at the upper end of valve body, it is equipped with flange 726, and for being communicated with fuel tank, and the second flow channels 7215 is positioned at the side of valve body, and it is communicated with master cylinder 103 rodless cavity.

Sealing cover 722 is fixedly arranged on first component 7211, and stuffing box gland 722 has the 3rd flow channels the 7221, three flow channels 7221 is communicated with valve body chamber 7213, first flow channels 7214 and the second flow channels 7215.In the present embodiment, stuffing box gland 722 is contained in the first flow channels 7214, in other embodiments, certainly also can be arranged on other positions of valve body.

Sealing body 723 is made up of special ceramic material (special ceramic material), and the inwall of its outer wall and the 3rd flow channels 7221 matches.Seal 723 and stuffing box gland 722 form one group of sealing pair structure.

Particularly, seal 723 has the outer wall 7231 of spheric, and the inwall of the 3rd flow channels 7221 has the spheric groove matched with spheric outer wall 7231, and seal 723 and stuffing box gland 722 form ball face sealing.

Wherein, this spheric groove can with reference to the structure (as Figure 20) of spheric groove shown in the first liquid-filling valve above-mentioned.

Please refer to Figure 21, in the present embodiment, seal 723 has two parallel end faces, sidewall 7231 between these two end faces is spheric, namely be equivalent to the plane cutting be parallel to each other with two by the seal 723 of a sphere-like, the part be positioned in the middle of two planes is the seal 723 shown in the present embodiment.And in order to increase the thickness of seal 723, the also extended one section of round platform after spheric sidewall of seal 723 shown in the present embodiment.

The present embodiment seal 723 adopts special ceramic material to make, and stuffing box gland 722 can adopt the softer alloy steel material of more special ceramic material to make, and both complement each other to form ball face sealing, can meet the requirement of strength of more than 45MPa hydraulic system 300.

In addition, stuffing box gland 722 also can adopt the softer material of other more special ceramic materials to make.

Meanwhile, the present embodiment provides a kind of method of the spheric groove manufactured on stuffing box gland 722:

The spheroid (highi degree of accuracy special the make pottery ball of such as 10G more than) consistent with seal spheric outer wall is adopted to extrude the hole wall of conical bore to apply super flow power, the hole wall of conical bore is formed the spheric groove matched with seal 723, the flow amount of this spheric groove is 0.1-3mm, such as 0.2-0.6mm.

Certainly, this spheric groove is also made by other machining modes.

This liquid-filling valve can adopt existing mode to control, and in addition, also can set up control unit for realizing ACTIVE CONTROL.

Please continue to refer to Figure 21, control unit 724 comprises the piston rod 7242 controlling oil cylinder 7241 and be placed in control oil cylinder 7241, control oil cylinder 7241 is divided into upper oil cavitie 7244 and lower oil cavitie 7245 by piston rod 7242, upper oil cavitie 7244 is communicated with selector valve by filler opening 728, and lower oil cavitie 7245 is communicated with selector valve by filler opening 729.Piston rod 7242 connects with seal 723, utilizes selector valve to realize the oil-feed of different hydraulic fluid port, thus promotion piston rod moves up and down, and opens or seal the 3rd flow channels 7221.

The affixed mode that the present embodiment adopts is that piston rod 7242 has bulb joint part, and set up a coupling rod 725, bulb joint part connects with coupling rod 725 simultaneously, and coupling rod 725 connects with seal 723.

Stretched out (namely seal is arranged in Fig. 2 23 present position) by selector valve 727 ACTIVE CONTROL piston rod 7242, seal 723 is separated with stuffing box gland 722, now sealing pair is opened, first flow channels 7214 is opened (at this moment the rodless cavity of hydraulic press master cylinder 103 is communicated with fuel tank), allow a large amount of fluid by the first flow channels 7214 and the second flow channels 7215, be back to fuel tank from master cylinder epicoele or from the quick topping up of fuel tank to master cylinder epicoele, meet the function requirement of hydraulic press skip forward/back.

When needs cut off, retracted by selector valve 727 ACTIVE CONTROL piston rod 7242, seal 723 and stuffing box gland 722 are fitted, first flow channels 7214 is closed, at this moment master cylinder epicoele and fuel tank cut off, and master cylinder epicoele has started straightening to working pressure, and hydraulic press enters compacting state.

The seal that liquid-filling valve shown in the present embodiment is made with special ceramic material and the stuffing box gland that alloyed steel is made, be processed into sealing pair, its sealing is reliable, can reach zero leakage, bear pressure very high.Meanwhile, Sealing can not used completely, make total compacter, easier for installation.

Control unit uses buffer structure, compact overall structure, the feature such as easy for installation, thus compensate for prior art liquid-filling valve Frequent Troubles completely, maintenance cost is high, and be not suitable for the deficiency of more than 40MPa press, overcome and cause pressure release as oppositely poorly sealed, or the hydraulic shock Universal Problems affecting the normal use of hydraulic system 300 and main frame such as excessive when opening.

Please refer to Figure 22, the third example liquid-filling valve, comprise valve component 731, plunger bushing 732, seal 733, control unit 734, coupling rod 735 and flange 736.

This valve body comprises first component 7311 and second component 7312, valve body has valve body chamber 7313, the chamber wall in valve body chamber 7313 has the first flow channels 7314 and the second flow channels 7315.Wherein the first flow channels 7314 is positioned at the side of valve body, it is equipped with flange 736, and for being communicated with fuel tank, and the second flow channels 7315 is positioned at the lower end of valve body, and it is communicated with master cylinder 103 rodless cavity.

This plunger bushing 732 is fixedly arranged on first component 7311, and plunger bushing 732 has the 3rd flow channels, and the 3rd flow channels and valve body chamber 7313 partially overlap, and is communicated with the first flow channels 7314 and the second flow channels 7315.In other embodiments, plunger bushing 732 also can be arranged on other positions of valve body certainly.

This plunger bushing 732 is made up of special ceramic material (special ceramic material).Sealing body 733 is also made up of special ceramic material (special ceramic material), and the inwall of its outer wall and the 3rd flow channels matches.Seal 733 and plunger bushing 732 form one group of trunk piston set structure.

Be clearance seal between seal 733 and plunger bushing 732, gap length is 0.001-0.012mm, such as 0.002-0.006mm.

Seal 733 is cylindrical shape, and its side pressure-bearing is crossed flow structure and drastically increased pressure-bearing grade and decrease control oil cylinder resistance.

This control unit 734 is for controlling the movement of seal, and its concrete structure can with reference to control unit shown in upper the first and the second liquid-filling valve.This control unit 734 is connected with seal 733 by piston rod 7341, opens or seal the 3rd flow channels to control seal 733.

Seal 733 is fixed by pull bar 7331 and coupling rod 735, and in control unit 734, piston rod 7341 has bulb joint part 7342, and bulb joint part 7342 connects with coupling rod 735.

Please continue to refer to Figure 22, the working procedure of liquid-filling valve shown in the present embodiment is as follows:

(i.e. position shown in 33 in Figure 22) is retracted by selector valve ACTIVE CONTROL piston rod 7341, plunger bushing 732 and seal 733 relative movement, sealing pair is opened, open the first flow channels 7314, now hydraulic press master cylinder 103 is communicated with fuel tank, a large amount of fluid is allowed to be back to fuel tank by the first flow channels 7314 and the second flow channels 7315 from master cylinder 103 or from the quick topping up of fuel tank to master cylinder 103, to meet the function requirement of hydraulic press skip forward/back.

When needs cut off, position shown in 733a in Figure 21 is extend out to by control unit 734 control piston bar 7341, seal 733 and plunger bushing 732 relative movement, when seal 733 hides the second flow channels 7315 mouthfuls, second flow channels 7315 is closed, at this moment master cylinder 103 rodless cavity has started straightening to working pressure, and hydraulic press enters compacting state.

Liquid-filling valve shown in the present embodiment makes trunk piston set structure with special ceramic material, is processed into sealing pair, and its sealing is reliable, can reach zero leakage, bear pressure very high.Meanwhile, Sealing can not used completely, make total compacter, easier for installation.

The more existing liquid-filling valve of liquid-filling valve shown in the present embodiment, reaction velocity is faster, opening and closing more flexibly and fast, reliability is higher, action is more secure, the requirement of strength of below 45MPa hydraulic system 300 can not only be met, also can meet the requirement of strength being greater than 45MPa hydraulic system 300, the hydraulic system 300 of such as 200-400MPa.

4th kind of example liquid-filling valve also comprises control gear on the basis that first three is planted.

This control gear matches with the seal in liquid-filling valve, in order to control the movement of seal.

Such as, control gear can adopt selector valve, utilizes fluid to control the movement of seal, and its connecting with liquid-filling valve can with reference to shown in above-mentioned the first and the second liquid-filling valve.

Such as, or the device that control gear also can promote seal movement for other, adopts solenoid directional control valve to drive seal initiatively mobile, realizes opening and sealing.

In the double hydraulic system 300 of the present embodiment, each parts and pipeline also can adopt high-pressure pipe connector to be connected, especially in the second tunnel hydraulic system.

High-pressure pipe connector is a kind of pipe joint that can be applied to more than 40MPa hydraulic system, and the present embodiment provides a kind of example pipe joint here.

Certainly other pipe joints that can be applicable to more than 40MPa hydraulic system also can be selected to replace pipe joint shown in this example.

First this example pipe joint provides a kind of adapter, comprises a body and body, and all have through flowing hole in the middle of described head body and body, described head body has the outer wall of spheric.

As the further improvement of described adapter, on described head body, the diameter of diapire is greater than the diameter of body, described head body is crossed out from tube wall and forms root angle.

This example pipe joint, comprising:

Adapter, the body that described adapter comprises a body and connects with head body, described head body has the outer wall of spheric;

Fittings body, described fittings body has flowing hole, and described flowing hole at least has the first hole section, and described first hole section is conical bore;

And link, described link has through hole, and one end is compressed part, described body one end is stretched in flowing hole, described link to be set on body and to be fixedly connected with fittings body, described compressed part props up adapter, the head body of adapter is pushed against the hole wall of the first hole section, the toroidal sealing surface that the hole wall making described head body that micro-elastic strain formation one circle and the first hole section occur is fitted.

As the further improvement of described pipe joint, on described head body, the diameter of diapire is greater than the diameter of body, described head body is crossed out from tube wall and forms root angle, described compressed part stretches in flowing hole, and the end of described compressed part props up described diapire, the hole wall of head body to the first hole section is compressed.

As the further improvement of described pipe joint, described flowing hole also comprises the second hole section, and described second hole section is communicated with the first hole section, and the hole wall of described second hole section has internal thread, described compressed part outer wall has outside thread, and described compressed part and the second hole section are spirally connected fixing.

As the further improvement of described pipe joint, the end outer wall of described compressed part has undergauge step.

As the further improvement of described pipe joint, the through hole of described link comprises the supported hole section, intermediate hole section and the adjusting hole section that are interconnected, described supported hole section internal diameter is basic equal with outer tube diameter, and described intermediate hole section internal diameter is greater than outer tube diameter, and described adjusting hole section becomes uncovered shape.

Particularly, please refer to Figure 23, this example pipe joint is a kind of pipe joint, and it comprises adapter 811, fittings body 812 and link 813.

This adapter 811 has through hole, and it can selective annealing process low carbon steel weldless tube.The head body 8112 that adapter 811 comprises body 8111 and connects with body 8111, head body 8112 has spheric outer wall.On this body 8112, the diameter of diapire 8113 is greater than the diameter of body 8111, a body 8112 is crossed out from the outer wall of body 8111 and forms root angle.This root angle can be arbitrarily angled, exemplary enumerates three here, and as 90 °, 115 ° or 135 °, wherein 115 ° and 135 ° are more conducive to stressed, occurs the problem of root crack after avoiding a body to use for more than 8112 time.

This fittings body 812 has flowing hole, and flowing hole is divided into the first hole section 8121, second hole section 8122 and the 3rd hole section 8123.

This first hole section 8121 is conical bore, and the second hole section 8122 is directly communicated with the first hole section 8121, and the hole wall of the second hole section 8122 has internal thread.3rd hole section 8123 is also directly communicated with the first hole section 8121, and its diameter can be in the same size with the channel internal diameter of adapter 811, for being communicated with other facility, valve block.Because fittings body 812 is generally seldom dismantled, the pipe thread 8124 be connected with facility, valve block can adopt taper pipe thread completely, can save adapter Sealing like this.

This link 813 has through hole, and one end is the compressed part 8131 of tubular, and compressed part 8131 outer wall has outside thread 8137, is spirally connected fixing for compressed part 8131 and the second hole section 8122.

During installation, body 8111 one end is stretched in flowing hole, link 813 is set on body 8111, compressed part 8131 to stretch in flowing hole and is spirally connected with fittings body 812, the end 8132 of compressed part 8131 props up the diapire 8113 of a body 8112 simultaneously, the hole wall of head body 8112 to the first hole section 8121 is compressed, makes a body 8112 that elastic strain formation one occur and enclose the shape of fitting with the first hole section 8121 wall.For this reason, on Material selec-tion, the hardness of fittings body 812 can be greater than the hardness of adapter 811.

Because the first hole section 8121 can fit tightly sealing with spheric head body 8112, therefore seal very reliable, pressure rating is very high, and repeatedly Reusability does not affect sealing effect.

Further, the end 8132 of compressed part 8131 is in order to better fit with this root angle, and make this end 8132 form leaning angle, leaning angle and root angle match.

In order to avoid link 813 is interferenceed with fittings body 812 when rotary, therefore end 8132 outer wall of compressed part 8131 has undergauge step 8133, dodges space to reserve.

Further, in the present embodiment, the through hole of link 813 comprises the supported hole section 8134, intermediate hole section 8135 and the adjusting hole section 8136 that are interconnected.

Wherein, supported hole section 8134 is for supporting the oscillatory forces of adapter 811, its internal diameter is basic equal with body 8111 external diameter, and namely the internal diameter of supported hole section 8134 is greater than body 8111 external diameter slightly, but this size can not cause adapter 811 to swing significantly in supported hole section 8134.

This intermediate hole section 8135 internal diameter is greater than body 8111 external diameter, and now the internal diameter of intermediate hole section 8135 is obviously greater than body 8111 external diameter, and effect is convenient to link 813 slide more swimmingly in adapter 811.

This adjusting hole section 8136 becomes uncovered shape, and shown in the present embodiment, uncovered shape is conical bore, and in other embodiments, certainly also can select other uncovered shape structures.It is angle for regulating adapter 811 and joint that the present embodiment arranges uncovered shape.

In pipe joint shown in the present embodiment, sealing pair is formed by the first hole section close contact of the spheric outer wall of head body 8112 and fittings body 812, link 813 imposes powerful pretightening force to head body 8112, obvious difference of hardness is had due to fittings body 812 material with between process hardness aspect and adapter 811, when impacting force acquires a certain degree, the contact segment generation resiliently deformable of head body 8112 and conical bore, make to be formed between sealing pair couple to fit tightly, at this moment be exactly good rigid seal state, now just not simple linear sealing but face sealing to a certain degree, so sealing is very reliable, pressure rating is very high, repeatedly Reusability does not affect sealing effect, the hard tube that can meet hydraulic system 300 pipeline of each pressure rating of below 1100Mpa and flow connects.

Link 813 be very beneficial for adapter 811 with the structure be connected in outside thread in fittings body 812 and pipe joint multidirectional stressed, be particularly suitable for the swing of bearing vibration and adapter after connecting in actual production, and be convenient to on-the-spot repeatedly pipeline adjustment.

Further, the material of fittings body 812 and link 813 can adopt high-quality middle-carbon steel or alloyed steel to obtain higher hardness and mechanical property through heat treatment, be beneficial to the mechanical strength forming difference of hardness with head body 8112 and obtain needed for high pressure, fittings body 812 and link 813 completely can by standard batch makings or customized in advance.

Meanwhile, pipe joint shown in the present embodiment does not need welding, need not separately add cutting ferrule, sleeve pipe, without welding slag, iron filings, fibrous impurity, sealing filler etc., clean simple and convenient.And axially natural centering is good also without the situation that cutting ferrule, fittings body taper hole are different, without the need to pre-installing.This structure has high vibration resistance and very strong anti-swing ability, so meet the connection of moving part without rubber parts simultaneously.

Certainly, based on the structure disclosed in the present embodiment, other distortion also can be done in other embodiments:

As, the compressed part 8131 of link 813 not props up the head body 8112 of adapter 811, but separately abutting part is established on body 8111, compressed part 8131 is coordinated with this abutting part adapter 811 is pressed on circular cone hole wall, and the cooperating structure of abutting part and compressed part 8131 can with reference to the cooperating structure of diapire in the present embodiment 8113 with compressed part 8131.Now, between head body 8112 and body 8111 outer wall, root angle can be set, also root angle can not be set; Meanwhile, as abutting part is arranged at outside flowing hole, so compressed part 8131 also can not extend in the flowing hole of fittings body.

As, fittings body 812 also can be made to have outside thread, and link 813 has internal thread, both are still spirally connected, but compressed part 8131 now only need push against a body 8112 or above-mentioned abutting part, in this case, even also can save the second hole section 8122;

As, fittings body 812 also can not arrange the 3rd hole section 8123, and the pipe thread be connected with facility, valve block can be arranged on the outer wall of the first hole section 8121 corresponding part.

The high pressure check valve that the present embodiment adopts is a kind of one-way valve that can be applied to more than 40MPa hydraulic system, and the present embodiment provides a kind of example uni-directional valve here.

Certainly other one-way valves that can be applicable to more than 40MPa hydraulic system also can be selected to replace one-way valve shown in this example.

This example uni-directional valve, comprise valve body, sealing seat and ball sealer, described valve body has valve body chamber, and described valve body chamber has filler opening and oil outlet, and described sealing seat is fixedly installed in valve body chamber, described sealing seat has flow channels, described ball sealer coordinates with the conduit wall of flow channels and realizes sealing, and the conduit wall of described flow channels has a circle groove, and described groove is spheric, described ball sealer is placed in flow channels, and its outer wall and spheric groove bonded to each other.

As the further improvement of described one-way valve, described one-way valve has oil circuit control and controls spool, described control spool slides and is arranged in valve body chamber, and described oil circuit control communicates with control spool, orders about control spool and moves thus open the sealing configuration between ball sealer and sealing seat.

As the further improvement of described one-way valve, described one-way valve has valve pocket, and described valve pocket is fixed in valve body chamber, and described control spool comprises steel core and is set in the core retainer plate outside core, and described valve pocket and core retainer plate are special ceramic material and make.

As the further improvement of described one-way valve, the hardness of described sealing seat is less than the hardness of ball sealer.

As the further improvement of described one-way valve, described sealing seat is alloyed steel sealing seat, and described ball sealer is special pottery ball.

As the further improvement of described one-way valve, described spy's pottery ball is zirconium oxide spy pottery ball or silicon nitride spy pottery ball.

As the further improvement of described one-way valve, described flow channels has one section of conicylindrical passage, and described groove is arranged on the inwall of conicylindrical passage.

As the further improvement of described one-way valve, the conduit wall of described ball sealer and flow channels fits through return springs and drives, and described return springs is arranged at ball sealer side, and its elastic force makes ball sealer abut the conduit wall of flow channels.

As the further improvement of described one-way valve, described one-way valve has guide piston, and described guide piston is arranged in valve body chamber or flow channels, and its one end coordinates with ball sealer, the other end coordinates with return springs, and described guide piston has the axial passage for overcurrent.

As the further improvement of described one-way valve, described guide piston has pit, described pit and ball sealer surface bonded to each other.

Particularly, please refer to Figure 24, this example uni-directional valve is common one-way valve.

This one-way valve comprises valve body 911, sealing seat 912, ball sealer 913, guide piston 914 and return springs 915.

This valve body 911 has valve body chamber 9111, and sealing seat 912 is fixedly installed in valve body chamber 9111, and means of fixation comprises fixing, drive fit of being spirally connected etc.

Sealing seat 912 has flow channels 9121, this flow channels 9121 is communicated with valve body chamber 9111, for liquid overcurrent.

Please refer to Figure 25, flow channels 9121 has one section of conicylindrical passage 9122, the inwall of this conicylindrical passage 9122 has a circle groove 9123, and this groove 9123 is spheric.

Certainly, in other embodiments, flow channels 9121 also can have one section of shoulder hole, and arranges a circle spheric groove in the turning point of shoulder hole inwall, and ball sealer 913 and this spheric groove forming surface are sealed and matched.

Or, also can be out of shape further on this conicylindrical passage and shoulder hole passage, form other modes of texturing.

In order to make spheric groove 9123 can the sealing station of tight envelope ball sealer 913, the hardness of ball sealer 913 can be made to be greater than the hardness of sealing seat 912.Such as, in the present embodiment, sealing seat 912 is alloyed steel sealing seat 912, namely obtains sealing seat 912 with alloy steel material.And ball sealer 913 is special pottery ball, namely with the obtained ball sealer 913 of special ceramic material (i.e. special ceramic material).

To make pottery ball for spy, the present embodiment provides two kinds of examples, is namely the obtained zirconium oxide spy pottery ball of raw material with zirconium oxide, and take silicon nitride as the obtained silicon nitride spy pottery ball of raw material.Above two kinds is only example, and obviously, special pottery ball also can select other special ceramic materials to obtain.

Meanwhile, the present embodiment provides a kind of method manufacturing spheric groove:

Adopt the spheroid (the highi degree of accuracy spy pottery ball of such as 10G more than) consistent with ball sealer to extrude the hole wall of conical bore to apply super flow power, the hole wall of conical bore is formed the spheric groove matched with ball sealer.

Certainly, this spheric groove is also made by other machining modes.

The present embodiment adopts special pottery ball 913 and alloyed steel sealing seat 912, huge difference of hardness is had between two couples, special pottery ball 913 its impact toughness except extreme hardness is also indispensable index, add the distinctive physical dimension stability of highi degree of accuracy circularity of special pottery ball 913, the impaired possibility of ball sealer 913 does not almost have.Sealing seat 912, due to the after heat treatment excellent comprehensive mechanical performance of alloyed steel, can bear general extruding and impact completely.Key is in the present embodiment, and the inwall of the circular cone passage of sealing seat 912 has the spheric groove 9123 of a rounding off, and its surface has quite high hardness and comprehensive mechanical intensity, and general impurity particle cannot be encroached on.And spheric groove 9123 apparent height is smooth, the foreign matters such as impurity particle cannot stop.

The elastic force of this return springs 915 makes ball sealer 913 abut the conduit wall of flow channels 9121.In the present embodiment, this return springs 915 is Compress Spring, and its one end is arranged on valve body 911 on the step of B mouth, and the other end props up guide piston 914.

This guide piston 914 is arranged in valve body chamber 9111 or flow channels 9121, and its one end coordinates with ball sealer 913.This Compress Spring can promote guide piston 914 and conduct ball sealer 913 to move to conicylindrical passage 9122.

Certainly, in other embodiments, also can utilize other modes that ball sealer 913 is moved to conicylindrical passage 9122, as relied on ball sealer 913 self gravitation.

Guide piston 914 can have at least one for the axial passage 142 of overcurrent, can be axial groove or hole, thus make liquid can flow to B mouth direction from A mouth.

Guide piston 914 one end can arrange pit 9141, and pit 9141 is bonded to each other with ball sealer 913 surface.

Under the guiding of guide piston 914, ball sealer 913 can precisely move along axis to sealing seat 912 conical bore, also makes to extrude and impact force does not put on region beyond spheric groove 9123.

The process of non-return valve operational shown in the present embodiment is as follows:

One-way valve entirety is connected with hydraulic circuit pipe with B interface external thread with A mouth internal thread, when A oral fluid force feed has pressure to be greater than Returnning spring resistance, pressure against the force of the spring promotes special pottery ball 913 and moves to B mouth, one-way valve opens, A mouth communicates with B oral fluid force feed, and when A oral fluid oil pressure is less than Returnning spring resistance, special pottery ball 913 is axially directed with under the recessed water hole control of Surface of Sphere under Returnning spring promotes and by piston, precisely move along axis to sealing seat 912 conical bore, closed check valve.

One-way valve shown in the present embodiment adopts face sealing, its sealing effect is very reliable, bear pressure huge, open closed fast flexibly, be not only applicable to each pressure rating hydraulic system 300 of below 100Mpa, but also the requirement being greater than each pressure rating hydraulic system 300 of 100Mpa can be met, such as 1100Mpa.

Above content is in conjunction with concrete mode of execution further description made for the present invention, can not assert that specific embodiment of the invention is confined to these explanations.For general technical staff of the technical field of the invention, without departing from the inventive concept of the premise, some simple deduction or replace can also be made.

Claims

1. a double hydraulic system, is characterized in that, comprising:

First via hydraulic system and the second tunnel hydraulic system;

Described first via hydraulic system comprises:

Low pressure pump group, described low pressure pump group is used for being connected with fuel tank carrying out pump oil;

First low pressure selector valve, described first low pressure selector valve has at least two-way output circuit, and the oil outlet of described low pressure pump group is connected with the filler opening of the first low pressure selector valve;

Described second tunnel hydraulic system comprises:

High pressure pump group, described high pressure pump group is used for being connected with fuel tank carrying out pump oil;

High-pressure reversing valve, described high-pressure reversing valve has at least one road output circuit, and the oil outlet of described high pressure pump group is connected with the filler opening of high-pressure reversing valve;

2. double hydraulic system as claimed in claim 1, it is characterized in that, described high-pressure liquid-filling valve comprises:

It is characterized in that, also comprise:

3. double hydraulic system as claimed in claim 2, it is characterized in that, described high-pressure liquid-filling valve also comprises:

4. double hydraulic system as claimed in claim 2, it is characterized in that, high-pressure liquid-filling valve also comprises:

5. the double hydraulic system as described in any one of claim 1-4, it is characterized in that, described high-pressure reversing valve is solenoid directional control valve, described solenoid directional control valve comprises valve body, spool, valve pocket and electromagnet assembly, described valve body has valve body chamber, the internal chamber wall in described valve body chamber has valve body filler opening, at least one valve body actuator port and valve pocket return opening, described valve pocket is fixedly installed in valve body chamber, described valve pocket has valve pocket chamber, described valve pocket chamber wall offers valve pocket filler opening, at least one valve pocket actuator port and valve pocket return opening, described valve pocket actuator port is communicated with valve body actuator port, described valve pocket filler opening is communicated with valve body filler opening, described valve pocket return opening is communicated with valve body return opening, described spool is loaded in valve pocket chamber, described spool and described valve pocket form sliding pair and clearance seal, described valve pocket and spool all adopt special ceramic material to make, described gap sealed gap length is 0.001-0.008mm.

6. double hydraulic system as claimed in claim 5, is characterized in that, described second tunnel hydraulic system adopts high-pressure pipe connector to connect, and described high-pressure pipe connector comprises:

And link, described link has through hole, and one end is compressed part, head body one end of described adapter is stretched in flowing hole, described link to be set on body and to be fixedly connected with fittings body, described compressed part props up adapter, the head body of adapter is pushed against the hole wall of the first hole section, makes described head body that micro-elastic strain occur and forms the sealing surface that encloses the toroidal of fitting with the hole wall of the first hole section.

7. double hydraulic system as claimed in claim 6, it is characterized in that, described high-pressure overflow valve comprises:

Elastic component;

And plunger bushing, described plunger bushing is fixed in valve body chamber, and its sidewall has oil outlet, and described oil outlet communicates with flow-off;

8. double hydraulic system as claimed in claim 7, it is characterized in that, described high pressure pump group comprises the first motor and plunger pump, described first motor drive plunger pump work; Described plunger pump comprises the pump housing, driving mechanism and trunk piston set assembly, and described trunk piston set assembly comprises plunger body, plunger and plunger bushing, and described plunger body is sealingly fastened on the pump housing, and has installation cavity and plunger hole; Described plunger and plunger bushing adopt special ceramic material to make, and described plunger bushing has plunger cavity, and described plunger at one end stretches in plunger cavity from plunger hole and forms sliding pair, and adopts clearance seal, and described clearance seal size is 0.001-0.012mm; Described plunger bushing is fixed in the installation cavity of plunger body, described plunger cavity is communicated with the plunger hole on plunger body, described plunger, plunger body, plunger bushing and the pump housing enclose pump grease chamber, the locular wall of described pump grease chamber has the hydraulic fluid port for passing in and out fluid, described driving mechanism coordinates with plunger, drive plunger moves back and forth, and changes the volume size of pump grease chamber.

9. double hydraulic system as claimed in claim 8, it is characterized in that, described high pressure pump group also comprises one-way valve, described one-way valve is arranged on the oil circuit in high pressure pump group, described one-way valve comprises valve body, sealing seat and ball sealer, described valve body has valve body chamber, described valve body chamber has filler opening and oil outlet, described sealing seat is fixedly installed in valve body chamber, described sealing seat has flow channels, described ball sealer coordinates with the conduit wall of flow channels and realizes sealing, it is characterized in that, the conduit wall of described flow channels has a circle groove, described groove is spheric, described ball sealer is placed in flow channels, and its outer wall and spheric groove bonded to each other.

10. the double hydraulic system as described in any one of claim 1-9, it is characterized in that, described first via hydraulic system also comprises the second low pressure selector valve, and it has filler opening, return opening and actuator port, and the oil outlet of described low pressure pump group is connected with the filler opening of the second low pressure selector valve; The actuator port of described second low pressure selector valve is connected with high-pressure liquid-filling valve, for controlling the opening and closing of high-pressure liquid-filling valve.

11. double hydraulic systems as described in any one of claim 1-9, it is characterized in that, described first via hydraulic system also comprises the 3rd low pressure selector valve, described 3rd low pressure selector valve has filler opening, return opening and actuator port, the filler opening of described 3rd low pressure selector valve is connected with low pressure pump group, the actuator port of described 3rd low pressure selector valve is used for being connected with ejection cylinder, drives ejection cylinder to eject lower table.

12. double hydraulic systems as described in any one of claim 1-9, it is characterized in that, have connecting passage between described first via hydraulic system and the second tunnel hydraulic system, the low pressure oil in the second tunnel hydraulic system is incorporated in first via hydraulic system by described connecting passage.

13. high low pressure double hydraulic systems as described in any one of claim 1-9, it is characterized in that, described second tunnel hydraulic system also comprises low pressure relief valve, and high pressure pump group is connected with fuel tank by described low pressure relief valve.

14. high low pressure double hydraulic systems as described in any one of claim 1-9, it is characterized in that, also comprise pressure relay, described pressure relay is installed on the hydraulic circuit of the second tunnel hydraulic system and/or first via hydraulic system, and it is for pressure measurement and signal is issued automatical control system.

15. 1 kinds of hydraulic presses, comprise main frame and power system, described main frame comprises clutch release slave cylinder system and frame worktable, described clutch release slave cylinder system comprises master cylinder, fast cylinder and stationary cylinder, there is between described stationary cylinder and master cylinder master cylinder epicoele and master cylinder cavity of resorption, between described fast cylinder and master cylinder, there is quick chamber, it is characterized in that, also comprise double hydraulic system as claimed in claim 1, described power system is connected with double hydraulic system, in described first via hydraulic system, one road output circuit of the first low pressure selector valve is connected with master cylinder cavity of resorption through the oil outlet of described one way sequence valve, another road output circuit of first low pressure selector valve is connected with quick chamber, master cylinder epicoele is connected with fuel tank by the flow channels of described high-pressure liquid-filling valve, one road output circuit of described second tunnel hydraulic system mesohigh selector valve is connected with master cylinder epicoele, described double hydraulic system drives master cylinder F.F. under power system controls, work is entered or rewind.

16. hydraulic presses as claimed in claim 1, it is characterized in that, described high-pressure liquid-filling valve comprises:

It is characterized in that, also comprise:

17. hydraulic presses as claimed in claim 16, it is characterized in that, described high-pressure liquid-filling valve also comprises:

18. hydraulic presses as claimed in claim 16, it is characterized in that, high-pressure liquid-filling valve also comprises:

19. hydraulic presses as described in any one of claim 15-18, it is characterized in that, described high-pressure reversing valve is solenoid directional control valve, described solenoid directional control valve comprises valve body, spool, valve pocket and electromagnet assembly, described valve body has valve body chamber, the internal chamber wall in described valve body chamber has valve body filler opening, at least one valve body actuator port and valve pocket return opening, described valve pocket is fixedly installed in valve body chamber, described valve pocket has valve pocket chamber, described valve pocket chamber wall offers valve pocket filler opening, at least one valve pocket actuator port and valve pocket return opening, described valve pocket actuator port is communicated with valve body actuator port, described valve pocket filler opening is communicated with valve body filler opening, described valve pocket return opening is communicated with valve body return opening, described spool is loaded in valve pocket chamber, described spool and described valve pocket form sliding pair and clearance seal, described valve pocket and spool all adopt special ceramic material to make, described gap sealed gap length is 0.001-0.008mm.

20. hydraulic presses as described in any one of claim 19, is characterized in that, described second tunnel hydraulic system adopts high-pressure pipe connector to connect, and described high-pressure pipe connector comprises:

21. hydraulic presses as claimed in claim 20, it is characterized in that, described high-pressure overflow valve comprises:

Elastic component;

22. hydraulic presses as claimed in claim 21, is characterized in that, described high pressure pump group comprises the first motor and plunger pump, described first motor drive plunger pump work; Described plunger pump comprises the pump housing, driving mechanism and trunk piston set assembly, and described trunk piston set assembly comprises plunger body, plunger and plunger bushing, and described plunger body is sealingly fastened on the pump housing, and has installation cavity and plunger hole; Described plunger and plunger bushing adopt special ceramic material to make, and described plunger bushing has plunger cavity, and described plunger at one end stretches in plunger cavity from plunger hole and forms sliding pair, and adopts clearance seal, and described clearance seal size is 0.001-0.012mm; Described plunger bushing is fixed in the installation cavity of plunger body, described plunger cavity is communicated with the plunger hole on plunger body, described plunger, plunger body, plunger bushing and the pump housing enclose pump grease chamber, the locular wall of described pump grease chamber has the hydraulic fluid port for passing in and out fluid, described driving mechanism coordinates with plunger, drive plunger moves back and forth, and changes the volume size of pump grease chamber.

23. hydraulic presses as claimed in claim 22, it is characterized in that, described high pressure pump group also comprises one-way valve, described one-way valve is arranged on the oil circuit in high pressure pump group, described one-way valve comprises valve body, sealing seat and ball sealer, described valve body has valve body chamber, described valve body chamber has filler opening and oil outlet, described sealing seat is fixedly installed in valve body chamber, described sealing seat has flow channels, described ball sealer coordinates with the conduit wall of flow channels and realizes sealing, it is characterized in that, the conduit wall of described flow channels has a circle groove, described groove is spheric, described ball sealer is placed in flow channels, and its outer wall and spheric groove bonded to each other.

24. hydraulic presses as described in any one of claim 16-23, it is characterized in that, described first via hydraulic system also comprises the second low pressure selector valve, and it has filler opening, return opening and actuator port, and the oil outlet of described low pressure pump group is connected with the filler opening of the second low pressure selector valve; The actuator port of described second low pressure selector valve is connected with high-pressure liquid-filling valve, for controlling the opening and closing of high-pressure liquid-filling valve.

25. hydraulic presses as described in any one of claim 16-23, it is characterized in that, described first via hydraulic system also comprises the 3rd low pressure selector valve, described 3rd low pressure selector valve has filler opening, return opening and actuator port, the filler opening of described 3rd low pressure selector valve is connected with low pressure pump group, the actuator port of described 3rd low pressure selector valve is used for being connected with ejection cylinder, drives ejection cylinder to eject lower table.