CN208346897U - Loader hydraulic system - Google Patents
Loader hydraulic system Download PDFInfo
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- CN208346897U CN208346897U CN201820650359.7U CN201820650359U CN208346897U CN 208346897 U CN208346897 U CN 208346897U CN 201820650359 U CN201820650359 U CN 201820650359U CN 208346897 U CN208346897 U CN 208346897U
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Abstract
The utility model discloses a kind of loader hydraulic systems, are related to engineering machinery field, to optimize existing system of loaders.The hydraulic system includes variable pump, pressure-gradient control valve, the first executive component and the second executive component.Variable pump is for exporting oil liquid；The control oil circuit of pressure-gradient control valve is used to switch the valve position of pressure-gradient control valve, so that pressure-gradient control valve is located at one of them following positions: the first working position, the second working position and the position between two valve positions.First executive component is in fluid communication by pressure-gradient control valve and variable pump, and the second executive component is in fluid communication by pressure-gradient control valve and variable pump.The control oil circuit of pressure-gradient control valve is configured to switch to when by pressure-gradient control valve in second working position, and controlling the oil liquid in oil circuit is flowing.Above-mentioned technical proposal, the oil liquid in the control oil circuit of pressure-gradient control valve is all flowing, and the oil liquid of flowing can transfer heat to the first executive component, to keep the temperature of the first executive component, so that it will not be in too low state of temperature.
Description
Technical field
The utility model relates to engineering machinery fields, and in particular to a kind of loader hydraulic system.
Background technique
Steering, swing arm operation and rotating bucket work etc. of the loader hydraulic system for loading machine.Its hydraulic system includes
Two pumps.Different according to the type of pump, loader hydraulic system includes full fixed dilivery hydraulic system, entire variable hydraulic system, monotropic
Measure three kinds of forms of hydraulic system.Wherein, full fixed dilivery hydraulic system refers to that two pumps used by hydraulic system are all constant displacement pumps, entirely
Variable delivery hydraulic system refers to that two pumps used by hydraulic system are all variable pumps, and single argument hydraulic system refers to hydraulic system institute
The one of pump used is variable pump, the other is constant displacement pump.
Full fixed dilivery hydraulic system system constitute it is simple, it is low in cost, but it uses Metering Flow Control Circuits, have spill losses,
Restriction loss, middle bit-loss, energy consumption is high and low efficiency.Entire variable hydraulic system is without spill losses, bit-loss, restriction loss without in
It is small, energy consumption is small and high-efficient but at high cost.Single argument hydraulic system energy-saving effect is preferable, moderate cost, sexual valence with higher
Than.
But existing single argument hydraulic system, there are some problems, variable pump in use needs to be changed according to specific manipulation
Become output flow, but due to the feedback lag of control signal, lead to flow low-response, manipulation comfort is poor, especially on cold ground
Area, oil viscosity increase, and oil liquid flow resistance increases, and lead to the obvious lag of system response.
Utility model content
The utility model proposes a kind of loader hydraulic systems, to optimize existing system of loaders.
The utility model provides a kind of loader hydraulic system, comprising:
Variable pump, for exporting oil liquid；
Pressure-gradient control valve, including the first working position, the second working position and control oil circuit, the control oil circuit are described excellent for switching
The valve position of first valve, so that the pressure-gradient control valve is located at one of them following positions: being separately in first working position, individually
Position in the second working position and between first working position and second working position；
First executive component passes through the pressure-gradient control valve and variable pump fluid communication in first working position；
And
Second executive component passes through the pressure-gradient control valve and variable pump fluid communication in second working position；
Wherein, the control oil circuit of the pressure-gradient control valve is configured to switch to when by the pressure-gradient control valve in second work
Position, the oil liquid controlled in oil circuit are flowings.
In one or more embodiments, the control oil circuit of the pressure-gradient control valve is also structured to work as the preferential Vavle switching
It is flowing to the oil liquid in the position between first working position and second working position, the control oil circuit.
In one or more embodiments, the pressure-gradient control valve includes two-position three-way valve；When the pressure-gradient control valve is in described the
The steering hydraulic fluid port of one working position, the oil inlet of the pressure-gradient control valve and the pressure-gradient control valve is connected to；When the pressure-gradient control valve is in described the
Two working positions, the oil inlet of the pressure-gradient control valve are connected to the actuator port of the pressure-gradient control valve.
In one or more embodiments, loader hydraulic system further include:
Flux amplification valve, between the steering hydraulic fluid port and first executive component of the pressure-gradient control valve；
Load-sensitive diverter is in fluid communication, for controlling the valve position of the flux amplification valve with the flux amplification valve；
Flow divider valve is set between the pressure-gradient control valve actuator port and second executive component, and is used for oil liquid
Distribution is into each second executive component；And
Control valve is set between the variable pump and the load-sensitive diverter, and for feeding back to the variable pump
Load pressure.
In one or more embodiments, the control valve is also connect with the pressure-gradient control valve, and the control valve is for controlling
Whether the control oil circuit of the pressure-gradient control valve is connected.
In one or more embodiments, the load-sensitive diverter is connect with the control valve, the load-sensitive
The oil liquid that diverter is used to control under the control oil circuit on state of the pressure-gradient control valve flows to fuel tank or first executive component.
In one or more embodiments, when the load-sensitive diverter is in middle position, the control oil of the pressure-gradient control valve
Oil liquid in road is connected to fuel tank；When the load-sensitive diverter is in left position or right position, the control oil of the pressure-gradient control valve
Oil liquid in road is connected to first executive component.
In one or more embodiments, the control oil circuit fluid of the first hydraulic fluid port of the control valve and the pressure-gradient control valve connects
Logical, the control port of the second hydraulic fluid port and the variable pump of the control valve is in fluid communication, the third hydraulic fluid port of the control valve with
The load feedback hydraulic fluid port of the load-sensitive diverter is in fluid communication, the 4th hydraulic fluid port of the control valve and going out for the variable pump
Hydraulic fluid port is in fluid communication；The control oil of the control port of the control valve and flow divider valve feedback valve group is in fluid communication；
Wherein, the control valve includes two working positions: when the control valve is in the first working position, the control valve
The third hydraulic fluid port of first hydraulic fluid port and the control valve is in fluid communication, the second hydraulic fluid port of the control valve and the 4th of the control valve
Hydraulic fluid port is in fluid communication；When the control valve is in the second working position, the of the second hydraulic fluid port of the control valve and the control valve
Three hydraulic fluid ports are in fluid communication, and the first hydraulic fluid port of the control valve and the 4th hydraulic fluid port of the control valve all end.
In one or more embodiments, the control oil circuit of the pressure-gradient control valve is equipped with first throttle component.
In one or more embodiments, the load feedback hydraulic fluid port of the load-sensitive diverter is equipped with the second throttle
Part.
Based on the above-mentioned technical proposal, the utility model embodiment at least can produce following technical effect:
The loader hydraulic system that above-mentioned technical proposal provides, the oil liquid in the control oil circuit of pressure-gradient control valve are all to flow,
The oil liquid of flowing can transfer heat to the first executive component, to keep the temperature of the first executive component, so that it will not locate
In the state of too low temperature；And the problem of preventing oil liquid in control piper viscosity be big at low temperature, poor fluidity.
Detailed description of the invention
Attached drawing described herein is used to provide a further understanding of the present invention, and is constituted part of this application,
The exemplary embodiment of the utility model and the description thereof are used to explain the utility model, does not constitute to the improper of the utility model
It limits.In the accompanying drawings:
Fig. 1 is loader hydraulic system schematic illustration provided by the embodiment of the utility model；
Fig. 2 is the schematic illustration of unloading valve in loader hydraulic system provided by the embodiment of the utility model.
Specific embodiment
Below with reference to Fig. 1, technical scheme provided by the present invention will be described in more detail.
Loader hydraulic system such as includes two pumps: a variable pump and a constant displacement pump or for two variable pumps.
If loader hydraulic system includes a variable pump and a constant displacement pump, for loading machine single argument hydraulic system.If loading machine
Hydraulic system includes two variable pumps, then is loading machine entire variable hydraulic system.
For loading machine single argument hydraulic system, variable pump can be according to the reality of the first executive component and the second executive component
The hydraulic oil of flow required for border demand exports, can make loading machine more energy saving in this way.Constant displacement pump can be defeated in variable pump
When oil liquid out is insufficient for system requirements, oil liquid required for system is provided.
For loading machine entire variable hydraulic system, one of variable pump can be used as auxiliary pump, in another variable pump
When the oil liquid of output is insufficient for system requirements, oil liquid required for system is provided.
The present embodiment introduces the technical solution of the present embodiment by taking loading machine single argument hydraulic system as an example in detail.
Referring to Fig. 1, the utility model embodiment provides a kind of loader hydraulic system, including variable pump 1, pressure-gradient control valve 3,
One executive component 2 and the second executive component 4.Variable pump 1 is for exporting oil liquid；The oil outlet 101 of pressure-gradient control valve 3 and variable pump 1 flows
Body connection.Pressure-gradient control valve 3 includes the first working position (shown in Figure 1 is upper), the second working position (bottom shown in Figure 1)
With control oil circuit 32.First executive component 2 is in fluid communication with the pressure-gradient control valve 3 in the first working position；Second executive component 4 and place
It is in fluid communication in the pressure-gradient control valve 3 of the second working position.Wherein, the control oil circuit 32 of pressure-gradient control valve 3 is configured to when the second executive component 4
When work, controlling the oil liquid in oil circuit 32 is flowing.
When pressure-gradient control valve 3 is in the first working position, the oil liquid that variable pump 1 exports is delivered to the first execution via pressure-gradient control valve 3
Element 2；When pressure-gradient control valve 3 is in the second working position, the oil liquid that variable pump 1 exports is delivered to second via pressure-gradient control valve 3 and executes member
Part 4；When pressure-gradient control valve 3 is in the position between the first working position and the second working position, the oil liquid that variable pump 1 exports preferentially is flowed to
First executive component 2, remaining oil liquid are delivered to the second executive component 4 by pressure-gradient control valve 3.This means, the first executive component 2 is preferential
The element of fuel feeding, when pressure-gradient control valve 3 is in the first working position, preferential oil circuit conducting.
Referring to Fig. 1, variable pump 1 includes oil outlet 101 and control port 102, and the control port 102 of variable pump 1, which is equipped with, to be become
Measuring mechanism 16 controls the pressure and flow of the oil outlet 101 of variable pump 1 by the stroking mechanism 16.The stroking mechanism 16 into
Hydraulic fluid port connects the second hydraulic fluid port B of following control valve 8, for via the second hydraulic fluid port B by the gross pressure of hydraulic system executive component
Feed back to stroking mechanism 16.Further, when only the first executive component 2 works, the pressure of the second hydraulic fluid port B of control valve 8
The substantially equal to outlet pressure of the first executive component 2.When only the second executive component 4 work when or 2 He of the first executive component
When second executive component 4 all works, the pressure of the second hydraulic fluid port B of control valve 8 is substantially equal to the outlet pressure of variable pump 1.
In one or more embodiments, the second executive component 4 includes two or more.Second executive component 4 tool
Body includes rotary ink tank 41, boom cylinder 42.Boom cylinder 42 such as includes multiple.
Referring to Fig. 1, loader hydraulic system further includes flux amplification valve 5, load-sensitive diverter 6,7 and of flow divider valve
Control valve 8.Flux amplification valve 5 is set between the steering hydraulic fluid port CF and the first executive component 2 of pressure-gradient control valve 3；Load-sensitive diverter 6
It is in fluid communication with flux amplification valve 5, for controlling the valve position of flux amplification valve 5.Flow divider valve 7 is set to the work of pressure-gradient control valve 3
Between hydraulic fluid port EF and the second executive component 4, for distributing oil liquid into each second executive component 4.
Flux amplification valve 5 and flow divider valve 7 use existing procucts.
Load-sensitive diverter 6 such as use three position five-way valve, including oil inlet, oil return opening, load feedback hydraulic fluid port and
Two actuator ports.When being in middle position, load feedback hydraulic fluid port is connected to the return port；When being in left position or right position, load is anti-
Feedback hydraulic fluid port is connected to one of actuator port.
First executive component 2 is such as steering cylinder, and the second executive component 4 is such as boom cylinder 42 and rotary ink tank 41
One of or it is a variety of.
As above-mentioned, pressure-gradient control valve 3 includes the first working position, the second working position and control oil circuit 32.In the present embodiment, pressure-gradient control valve
3 specifically use two-position three-way valve, and when it is in the first working position, CF oil circuit (i.e. preferential oil circuit) conducting, the preferential oil circuit connects
It is connected to the first executive component 2.When it is in the second working position, EF oil circuit (i.e. non-preferential oil circuit, working oil path) conducting, the EF
Oil circuit connection is to the second executive component 4.If the second executive component 4 includes boom cylinder 42 and rotary ink tank 41, the EF simultaneously
Oil circuit is connected to boom cylinder 42 and rotary ink tank 41 simultaneously.Specifically, in this case, setting flux amplification valve 5, the flow are put
Big valve 5 is responsible for oil mass required for each executive component of distribution.EF oil communication is divided to flux amplification valve 5 by flux amplification valve 5
The each rotary ink tank 41 of dispensing and boom cylinder 42.Pressure-gradient control valve 3 CF oil circuit work independently of one another with EF oil circuit to be independent of each other,
But preferentially to guarantee the flow of CF oil circuit, residual flow goes work system by EF oil circuit.
The control oil circuit connection of above-mentioned pressure-gradient control valve 3 connects in the first hydraulic fluid port A of control valve 8, the third hydraulic fluid port C of control valve 8
Connect the load feedback hydraulic fluid port of load-sensitive diverter 6, the oil outlet 101 of the 4th hydraulic fluid port D link variable pump 1 of control valve 8.
Control valve 8 is described below.
Referring to Fig. 1, the first hydraulic fluid port A of control valve 8 and the control oil circuit of pressure-gradient control valve 3 are in fluid communication, the second oil of control valve 8
The control port of mouth B and variable pump 1 is in fluid communication, the third hydraulic fluid port C of control valve 8 and the load feedback of load-sensitive diverter 6
Hydraulic fluid port is in fluid communication, and the 4th hydraulic fluid port D of control valve 8 and the oil outlet of variable pump 1 are in fluid communication；The control port of control valve 8 with
The control oil feedback valve group (being specially the oil inlet of shuttle valve group 13 in the present embodiment) of flow divider valve 7 is in fluid communication.
Wherein, control valve 8 includes two working positions: when control valve 8 is in the first working position, the first hydraulic fluid port A of control valve 8
It is in fluid communication with the third hydraulic fluid port C of control valve 8, the second hydraulic fluid port B of control valve 8 and the 4th hydraulic fluid port D of control valve 8 are in fluid communication.
When control valve 8 is in the second working position, the second hydraulic fluid port B of control valve 8 and the third hydraulic fluid port C of control valve 8 are in fluid communication, control valve
8 the first hydraulic fluid port A and the 4th hydraulic fluid port D of control valve 8 end.
In the present embodiment, control valve 8 uses two position four-way valves comprising two working positions, i.e. upper in Fig. 1 and under
Position.When control valve 8 be in it is upper when, the first hydraulic fluid port A of control valve 8 be connected to third hydraulic fluid port C, the second hydraulic fluid port B of control valve 8 with
4th hydraulic fluid port D is connected under this working position state, is by the stroking mechanism 16 of the outlet pressure feedback of variable pump 1 to variable pump 1.When
When control valve 8 is in the next, the second hydraulic fluid port B of control valve 8 is connected to third hydraulic fluid port C, the first hydraulic fluid port of control valve 8 and the 4th oil
Mouth is in off state.Under this working position state, be by the pressure feedback of the load feedback hydraulic fluid port of load-sensitive diverter 6 extremely
The stroking mechanism 16 of variable pump 1.Above two feedback can make variable pump 1 actually required according to each executive component
The reality output flow of flow control variable pump 1, so that system of loaders is more energy saving.
Be described below control valve 8 when switch operating position.The control port of control valve 8 and the control oil of flow divider valve 7
It feeds back valve group to be in fluid communication, when flow divider valve 7 works, the control port oil inlet of control valve 8, control valve 8 switches to upper
Work.At this point, the control port of variable pump 1 is connected to the oil outlet of variable pump 1.Operating condition corresponding to this situation is only second
The work of executive component 4, the first executive component 2 and the second executive component 4 work two kinds of situations.
When flow divider valve 7 does not work, the control port of control valve 8 does not have oil inlet, and control valve 8 switches to the next work
Make.Corresponding operating condition is the work of only the first executive component 2 at this time.It is by the load of load-sensitive diverter 6 under the operating condition
The pressure feedback of hydraulic fluid port is fed back to the control port of variable pump 1.The pressure of the load feedback hydraulic fluid port of load-sensitive diverter 6 is substantially
Equal to the outlet pressure of the first executive component 2.
Pressure-gradient control valve 3 is described below.Pressure-gradient control valve 3 uses two-position three-way valve.The control oil circuit 32 of the pressure-gradient control valve 3 is configured to work as
Oil liquid in second executive component 4 work time control liquefaction road 32 is flowing.At this time regardless of whether the first executive component 2 works,
It is flowing that it, which controls the oil liquid in oil circuit 32,.The first situation controls in oil circuit 32 if the first executive component 2 is failure to actuate
Oil liquid directly flow back to fuel tank or other with oily components.If the first executive component 2 acts, the oil liquid controlled in oil circuit 32 passes through
Load-sensitive diverter 6 flows back to the first executive component 2.
The control oil circuit 32 of pressure-gradient control valve 3 is used for so that 3 switching valve position of pressure-gradient control valve.Hold it is above-mentioned, pressure-gradient control valve 3 have CF oil circuit and
EF oil circuit can make a wherein conducting for CF oil circuit and EF oil circuit, CF oil circuit and EF oil circuit can also be made to be both turned on.It is excellent
What the control oil circuit of first valve 3 was connected with CF oil circuit, but it is micro- equipped with being connected between the control oil circuit and the oil inlet of pressure-gradient control valve 3
Hole, even if therefore CF oil circuit completely it is obstructed in the case where, also can guarantee control oil circuit in have oil liquid.When the control oil of pressure-gradient control valve 3
It when road is in the conductive state, is connected to by the third hydraulic fluid port of control valve 8 with fuel tank, the oil liquid controlled in oil circuit continues to flow to oil
Case.Since control oil circuit is small-sized, even if therefore flowing to fuel tank also and can guarantee that control oil circuit controls the working position of pressure-gradient control valve 3.
Referring to Fig. 1, in one or more embodiments, the control oil circuit 32 of pressure-gradient control valve 3 is equipped with first throttle component 31, with
So that the oil liquid flowing in control oil circuit 32 makes also to can guarantee the pressure in control oil circuit 32, so that pressure-gradient control valve 3 is maintained at EF oil
The position of road conducting.
Referring to Fig. 1, the load feedback hydraulic fluid port of load-sensitive diverter 6 is equipped with the second throttle part 61, moves so that pressure-gradient control valve 3
Control oil circuit 32 when being connected to the load feedback hydraulic fluid port of load-sensitive diverter 6, oil circuit between the two keeps certain pressure
Power.
Flow divider valve 7 is described below.Referring to Fig. 1, a1, b1, a2 and b2 of the shuttle valve group 13 of flow divider valve 7 can be with
The oil outlet 101 of variable pump 1 connects, and specifically, referring to Fig. 1, pilot valve 12 and shuttle valve group 13 cooperation control flow jointly is arranged
The working position of amplifying valve 5.The movement of rotary ink tank 41 and boom cylinder 42 includes stretching out, bouncing back.I.e. the stretching of rotary ink tank 41,
The retraction of rotary ink tank 41, the stretching of boom cylinder 42, boom cylinder 42 four kinds of states of retraction.The hydraulic fluid port a1 of pilot valve 12,
A2, b1, b2 respectively correspond the corresponding delivery outlet of shuttle valve group 13, to correspond to above-mentioned four kinds of shapes of rotary ink tank 41 and boom cylinder 42
State.
The specific embodiment of the present embodiment is introduced below with reference to Fig. 1.
As shown in Figure 1, a kind of loading machine single argument hydraulic system of the utility model, including variable pump 1, constant displacement pump, off-load
Valve, control valve 8, load-sensitive diverter 6, pressure-gradient control valve 3, flux amplification valve, steering cylinder, rotary ink tank 41, boom cylinder 42,
Flow divider valve 7, pilot valve 12, shuttle valve group 13, cooler 9, filter, pilot valves 10, shut-off valve 11, fuel tank 18 and limit
Valve.The outlet of variable pump 1 is connected with 3 import of pressure-gradient control valve, and 3 hydraulic fluid port CF of pressure-gradient control valve is connected with flux amplification valve import.Quantitative pump discharge
Be connected to 7 import of flow divider valve together by unloading valve and 3 hydraulic fluid port EF of pressure-gradient control valve, load-sensitive diverter 6 through limit valve with
Flux amplification valve connection, and the steering cylinder being connected with flux amplification valve is controlled through flux amplification valve.10 oil inlet of pilot valves with
The outlet of variable pump 1 is connected, and pilot valves 10 are connect through shut-off valve 11 with pilot valve 12, and pilot valve 12 is through shuttle valve group 13 and flow point
It is connected with valve 7, and controls the rotary ink tank 41 and boom cylinder 42 that are connected with flow divider valve 7 through flow divider valve 7.Flow point
Oil return with valve 7, flux amplification valve 5 and unloading valve 17 is connect through subcooler 9, filter 14 with fuel tank 18, shuttle valve group 13 with
The connection of 8 control terminal of control valve, the control mouth of pressure-gradient control valve 3, the load feedback mouth of load-sensitive diverter 6, the oil outlet of variable pump 1
101 and the control port 102 of variable pump 1 be connected respectively with A, C, D, B hydraulic fluid port of control valve 8.
As shown in Fig. 2, unloading valve 17 in the loader hydraulic system include check valve 171, it is first segment discharge orifice 172, suitable
Sequence valve 173, safety valve 174 and the second throttle orifice 175.It is arranged between 17 oil outlet OX of 17 oil inlet P X of unloading valve and unloading valve
There is the check valve 171 towards oil outlet OX.173 control mouth of sequence valve passes through first segment discharge orifice 172 and 17 oil outlet OX of unloading valve
Connection, after 173 oil inlet of sequence valve is connected to 174 control mouth of safety valve, through the second throttle orifice 175 in 17 oil inlet P X of unloading valve
Connection, 17 oil inlet P X of unloading valve are connected to 174 oil inlet AX of safety valve, and 174 oil outlet BX of safety valve and sequence valve 173 are fuel-displaced
Mouth is connected to with 17 oil return inlet T X of unloading valve.When 17 oil outlet OX pressure of unloading valve sets pressure lower than sequence valve 173, sequence
Valve 173 is closed, and 174 control mouth pressure of safety valve is identical as 174 oil inlet AX pressure of safety valve, and safety valve 174 cannot be opened, and unload
The oil outlet OX of unloading valve 17 is flowed out in the oil inlet of 17 oil inlet P X of lotus valve by check valve 171.When 17 oil outlet OX of unloading valve is pressed
When power is higher than the setting pressure of sequence valve 173, sequence valve 173 is opened, and the oil liquid of 17 oil inlet P X of unloading valve passes through the second throttle orifice,
17 oil outlet OX of unloading valve is flowed out by sequence valve 173,174 control mouth pressure of safety valve is lower than 174 oil inlet of safety valve at this time
AX pressure, safety valve 174 are opened, and the oil inlet of 17 oil inlet P X of unloading valve flows out 17 oil return inlet T X of unloading valve by safety valve 174,
Check valve 171 prevents 17 oil outlet OX of unloading valve from blowing back into 17 oil inlet P X of unloading valve.
The working principle of the utility model embodiment above-mentioned technical proposal is as follows:
Referring to Fig. 1, when complete machine starts attonity, load-sensitive diverter 6 and pilot valve 12 are in middle position, pilot valve 12
Without output, 13 hydraulic fluid port X of shuttle valve group is also without output, and 8 hydraulic control end no pressure of control valve, control valve 8 is in the next work.This valve position shape
Under state, the hydraulic fluid port B of control valve 8 is connected to hydraulic fluid port C, and the hydraulic fluid port A and hydraulic fluid port D of control valve 8 are disconnected.I.e. control valve is in this valve position
When, 6 control mouth of load-sensitive diverter is connected to 1 control mouth of variable pump, 3 control mouth of pressure-gradient control valve and 1 oil outlet 101 1 of variable pump
Road binders disconnects.6 control mouth no pressure of load-sensitive diverter feedback, discharge capacity under the action of internal stroking mechanism 16 of variable pump 1
It goes to zero, 1 oil outlet 101 of variable pump only maintains a lower standby pressure, bit-loss and spill losses without in.Pressure-gradient control valve 3
Control mouth closing, 3 spool of pressure-gradient control valve is maintained under spring force turns to position, and flux amplification valve 5 is in and closes middle position, no oil liquid
Flow divider valve 7 is flowed to by 3 hydraulic fluid port EF of pressure-gradient control valve.Flow divider valve 7 is in and opens middle position, and the oil liquid of constant displacement pump 19 is compared with low pressure
Power flows back to fuel tank 18 by unloading valve 17, flow divider valve 7, cooler 9 and filter 14, reduces middle bit-loss.
Referring to Fig. 1, when complete machine starting only turns to, pilot valve 12 is in middle position, and pilot valve 12 is without output, 13 oil of shuttle valve group
Mouth X is also without output, and 8 hydraulic control end no pressure of control valve, control valve 8 is in the next function.Under this valve position state, the oil of control valve 8
Mouth B is connected to hydraulic fluid port C, and the hydraulic fluid port A and hydraulic fluid port D of control valve 8 are disconnected, i.e., by 6 control mouth of load-sensitive diverter and variable pump 1
101 1 road binders of oil outlet of control mouth connection, 3 control mouth of pressure-gradient control valve and variable pump 1 disconnects.When load-sensitive diverter 6 acts,
Load-sensitive diverter 6 exports oil liquid and is subjected to displacement by the reversing valve core that limit valve 15 controls flux amplification valve 5, spool displacement
Size depends on 6 output flow of load-sensitive diverter, and it is logical that the spool displacement of flux amplification valve 5 makes variable pump 1 export oil liquid
Pressure-gradient control valve 3 is crossed, drives the first executive component 2 (specially steering cylinder) to turn to by flux amplification valve 5, while load-sensitive turns
To 6 control mouth of device by the control port 102 of pressure feedback to variable pump 1, the stroking mechanism 16 of variable pump 1 is adjusted according to feedback is automatic
The discharge capacity of integer variable pump 1, to meet system flow demand, the flow that variable pump 1 provides does not have extra spill losses.Pressure-gradient control valve
The closing of 3 control mouths, 3 spool of pressure-gradient control valve is maintained under spring force turns to position, and no oil liquid is flowed to by 3 hydraulic fluid port EF of pressure-gradient control valve
Flow divider valve 7.Flow divider valve 7, which is in, opens middle position, and the oil liquid of constant displacement pump 19 passes through unloading valve 17, flow point with lower pressure
Fuel tank 18 is flowed back to valve 7, cooler 9 and filter 14, reduces middle bit-loss.
Referring to Fig. 1, when only the second executive component 4 works for complete machine starting, 6 control mouth no pressure of load-sensitive diverter is anti-
Feedback, when pilot valve 12 has movement, pilot valve 12 exports oil liquid control flow divider valve 7 and commutates, while 13 hydraulic fluid port X of shuttle valve group is exported
Oil liquid is controlled to 8 hydraulic control end of control valve, control valve 8 commutates upper work.Under this valve position state, the hydraulic fluid port A and hydraulic fluid port of control valve 8
C connection, the hydraulic fluid port B of control valve 8 are connected to hydraulic fluid port D, i.e., are connected to 6 control mouth of load-sensitive diverter with 3 control mouth of pressure-gradient control valve,
The control port 102 of variable pump 1 is connected to 101 1 road binders of oil outlet of variable pump 1.The control mouth and load-sensitive of pressure-gradient control valve 3
6 control mouth of diverter is connected to while taking back fuel tank 18, and pressure-gradient control valve 3 changes under the control of left and right ends fluid control pressure and spring force
It works to bottom.3 control mouth of pressure-gradient control valve to 6 control mouth of load-sensitive diverter has oil liquid flowing, oil liquid heat energy always at this time
It is transferred to the first executive component 2, so that the temperature of the first executive component 2 will not be too low, is more suitable for low temperature environment.
Referring to Fig. 1, in the movement of only the second executive component 4, when pilot valve 12 has movement, pilot valve 12 exports oil liquid control
The commutation of flow divider valve 7 processed to a certain position, the oil liquid of variable pump 1 drives rotary ink tank by pressure-gradient control valve 3 and flow divider valve 7
41 or boom cylinder 42,101 pressure of oil outlet of variable pump 1 is transmitted to the control port 102 of variable pump 1 by control valve 8, becomes
Amount pump 1 becomes delivery output flow.The oil liquid of constant displacement pump 19 drives rotary ink tank 41 by unloading valve 17 and flow divider valve 7
With at least one of which of boom cylinder 42.When work system pressure is higher than the pressure set points of sequence valve 173 in unloading valve 17
When, the oil liquid of constant displacement pump 18 reduces high pressure overflow loss by 17 Low-pressure load discharge of unloading valve.When work system pressure reaches change
When amount 1 pressure shut-off valve setting value of pump, the discharge capacity of the stroking mechanism adjust automatically variable pump 1 in variable pump 1 goes to zero, variable pump
1 is in high pressure standby mode, no spill losses.
Referring to Fig. 1, when complete machine starts while turning to and working, 6 control mouth of load-sensitive diverter has pressure feedback, first
When pilot valve 12 has movement, pilot valve 12 exports oil liquid control flow divider valve 7 and commutates, while 13 hydraulic fluid port X of shuttle valve group output control
To 8 hydraulic control end of control valve, control valve 8 commutates upper work oil liquid.Under this valve position state, the hydraulic fluid port A and hydraulic fluid port C of control valve 8 connect
Logical, the hydraulic fluid port B of control valve 8 is connected to hydraulic fluid port D, i.e., is connected to 6 control mouth of load-sensitive diverter with 3 control mouth of pressure-gradient control valve, is become
Amount 1 control mouth of pump exports a road binders with variable pump 1 and is connected to.3 control mouth of pressure-gradient control valve is connected to 6 control mouth of load-sensitive diverter,
The pressure difference and 6 oil inlet and outlet pressure difference of load-sensitive diverter at 3 spool both ends of pressure-gradient control valve are adapted.3 spool both ends of pressure-gradient control valve at this time
Pressure is all from 3 hydraulic fluid port CF of pressure-gradient control valve, and pressure change response is fast, and system response is fast.
Referring to Fig. 1, when load-sensitive diverter 6 acts, the oil liquid of variable pump 1 is preferentially met by pressure-gradient control valve 3 to be turned to
System requirements, extra flow are collaborated by 3 hydraulic fluid port EF of pressure-gradient control valve into work system.When pilot valve 12 has movement, pilot valve 12
Oil liquid control flow divider valve 7 commutation is exported to a certain position, the oil liquid of variable pump 1 passes through 3 hydraulic fluid port EF of pressure-gradient control valve and flow point
Rotary ink tank 41 or boom cylinder 42 are driven with valve 7,1 outlet pressure of variable pump is transmitted to the control of variable pump 1 by control valve 8
Mouthful, variable pump 1 becomes delivery output flow.The oil liquid of constant displacement pump drives rotating bucket oil by unloading valve 17 and flow divider valve 7
Cylinder 41 or boom cylinder 42.
In the description of the present invention, it should be understood that term " center ", " longitudinal direction ", " transverse direction ", "front", "rear",
The orientation or positional relationship of the instructions such as "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outside" is based on attached drawing institute
The orientation or positional relationship shown is only the utility model and simplified description for ease of description, rather than indicates or imply meaning
Device or element must have a particular orientation, construct and operate for specific orientation, thus should not be understood as practical new to this
The limitation of type protection content.
Finally, it should be noted that above embodiments are only to illustrate the technical solution of the utility model, rather than its limitations；
Although the utility model is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that:
It is still possible to modify the technical solutions described in the foregoing embodiments, or part of technical characteristic is carried out etc.
With replacement, but these are modified or replaceed, various embodiments of the utility model technology that it does not separate the essence of the corresponding technical solution
The spirit and scope of scheme.
Claims (10)
1. a kind of loader hydraulic system characterized by comprising
Variable pump (1), for exporting oil liquid；
Pressure-gradient control valve (3), including the first working position, the second working position and control oil circuit, the control oil circuit are described excellent for switching
The valve position of first valve (3), so that the pressure-gradient control valve (3) is located at one of them following positions: being separately in first work
Position is separately in the second working position and the position between first working position and second working position；
First executive component (2) passes through the pressure-gradient control valve (3) and the variable pump (1) fluid in first working position
Connection；And
Second executive component (4) passes through the pressure-gradient control valve (3) and the variable pump (1) fluid in second working position
Connection；
Wherein, the control oil circuit of the pressure-gradient control valve (3) is configured to work as and switches to the pressure-gradient control valve (3) in second work
Make position, the oil liquid in the control oil circuit is flowing.
2. loader hydraulic system according to claim 1, which is characterized in that the control oil circuit of the pressure-gradient control valve (3) is also
It is configured to when the position switched to the pressure-gradient control valve (3) between first working position and second working position,
Oil liquid in the control oil circuit is flowing.
3. loader hydraulic system according to claim 1, which is characterized in that the pressure-gradient control valve (3) includes two-bit triplet
Valve；When the pressure-gradient control valve (3) are in first working position, the oil inlet of the pressure-gradient control valve (3) and turning for the pressure-gradient control valve (3)
It is connected to hydraulic fluid port (CF)；When the pressure-gradient control valve (3) are in second working position, the oil inlet of the pressure-gradient control valve (3) and described
The actuator port (EF) of pressure-gradient control valve (3) is connected to.
4. loader hydraulic system according to claim 3, which is characterized in that further include:
Flux amplification valve (5) is set between the steering hydraulic fluid port and first executive component (2) of the pressure-gradient control valve (3)；
Load-sensitive diverter (6) is in fluid communication, for controlling the flux amplification valve (5) with the flux amplification valve (5)
Valve position；
Flow divider valve (7) is set between the actuator port (EF) and second executive component (4) of the pressure-gradient control valve (3), and
For distributing oil liquid into each second executive component (4)；And
Control valve (8) is set between the variable pump (1) and the load-sensitive diverter (6), and is used for the variable pump
(1) feedback load pressure.
5. loader hydraulic system according to claim 4, which is characterized in that the control valve (8) also with it is described preferential
Whether valve (3) connection, the control oil circuit (32) that the control valve (8) is used to control the pressure-gradient control valve (3) are connected.
6. loader hydraulic system according to claim 5, which is characterized in that the load-sensitive diverter (6) and institute
Control valve (8) connection is stated, the load-sensitive diverter (6) is used to control control oil circuit (32) conducting of the pressure-gradient control valve (3)
Oil liquid under state flows to fuel tank (18) or first executive component (2).
7. loader hydraulic system according to claim 6, which is characterized in that at the load-sensitive diverter (6)
Yu Zhongwei, the oil liquid in the control oil circuit (32) of the pressure-gradient control valve (3) are connected to fuel tank (18)；When the load-sensitive diverter
(6) it is in left position or right position, the oil liquid in the control oil circuit (32) of the pressure-gradient control valve (3) is connected to first executive component
(2)。
8. loader hydraulic system according to claim 5, which is characterized in that the first hydraulic fluid port (A) of the control valve (8)
It is in fluid communication with the control oil circuit (32) of the pressure-gradient control valve (3), the second hydraulic fluid port (B) and the variable pump of the control valve (8)
(1) control port is in fluid communication, the load of the third hydraulic fluid port (C) of the control valve (8) and the load-sensitive diverter (6)
It feeds back hydraulic fluid port to be in fluid communication, the 4th hydraulic fluid port (D) of the control valve (8) and oil outlet (101) fluid of the variable pump (1) connect
It is logical；The control port of the control valve (8) and the control oil feedback valve group of the flow divider valve (7) are in fluid communication；
Wherein, the control valve (8) includes two working positions: when the control valve (8) are in the first working position, the control valve
(8) the third hydraulic fluid port (C) of the first hydraulic fluid port (A) and the control valve (8) is in fluid communication, the second hydraulic fluid port of the control valve (8)
(B) it is in fluid communication with the 4th hydraulic fluid port (D) of the control valve (8)；When the control valve (8) are in the second working position, the control
The second hydraulic fluid port (B) of valve (8) processed and the third hydraulic fluid port (C) of the control valve (8) are in fluid communication, and the first of the control valve (8)
4th hydraulic fluid port (D) of hydraulic fluid port (A) and the control valve (8) all ends.
9. loader hydraulic system according to claim 6, which is characterized in that the control oil circuit of the pressure-gradient control valve (3)
(32) first throttle component (31) are equipped with.
10. loader hydraulic system according to claim 6, which is characterized in that the load-sensitive diverter (6) is born
It carries feedback hydraulic fluid port and is equipped with the second throttle part (61).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820650359.7U CN208346897U (en) | 2018-05-03 | 2018-05-03 | Loader hydraulic system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820650359.7U CN208346897U (en) | 2018-05-03 | 2018-05-03 | Loader hydraulic system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN208346897U true CN208346897U (en) | 2019-01-08 |
Family
ID=64888343
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201820650359.7U Active CN208346897U (en) | 2018-05-03 | 2018-05-03 | Loader hydraulic system |
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| Country | Link |
|---|---|
| CN (1) | CN208346897U (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110578726A (en) * | 2019-09-29 | 2019-12-17 | 徐工集团工程机械股份有限公司科技分公司 | hydraulic system with quantitative system variable |
| CN110762075A (en) * | 2019-10-28 | 2020-02-07 | 雷沃工程机械集团有限公司 | Steering system and method based on improved hydraulic steering bypass priority valve |
| CN110848185A (en) * | 2019-11-11 | 2020-02-28 | 雷沃工程机械集团有限公司 | Hydraulic control system and method for wheel type engineering machinery |
| CN112334669A (en) * | 2019-03-28 | 2021-02-05 | 日立建机株式会社 | Construction machine |
| CN113494111A (en) * | 2021-07-27 | 2021-10-12 | 柳州柳工液压件有限公司 | Main control valve, fixed variable hydraulic system and loader |
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2018
- 2018-05-03 CN CN201820650359.7U patent/CN208346897U/en active Active
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112334669A (en) * | 2019-03-28 | 2021-02-05 | 日立建机株式会社 | Construction machine |
| CN110578726A (en) * | 2019-09-29 | 2019-12-17 | 徐工集团工程机械股份有限公司科技分公司 | hydraulic system with quantitative system variable |
| CN110578726B (en) * | 2019-09-29 | 2024-04-30 | 徐工集团工程机械股份有限公司科技分公司 | Quantitative system variable hydraulic system |
| CN110762075A (en) * | 2019-10-28 | 2020-02-07 | 雷沃工程机械集团有限公司 | Steering system and method based on improved hydraulic steering bypass priority valve |
| CN110762075B (en) * | 2019-10-28 | 2021-11-23 | 雷沃工程机械集团有限公司 | Steering system and method based on improved hydraulic steering bypass priority valve |
| CN110848185A (en) * | 2019-11-11 | 2020-02-28 | 雷沃工程机械集团有限公司 | Hydraulic control system and method for wheel type engineering machinery |
| CN110848185B (en) * | 2019-11-11 | 2021-11-23 | 雷沃工程机械集团有限公司 | Hydraulic control system and method for wheel type engineering machinery |
| CN113494111A (en) * | 2021-07-27 | 2021-10-12 | 柳州柳工液压件有限公司 | Main control valve, fixed variable hydraulic system and loader |
| CN113494111B (en) * | 2021-07-27 | 2022-08-05 | 柳州柳工液压件有限公司 | Main control valve, fixed variable hydraulic system and loader |
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