CN112814964A - Valveless reversing device and method - Google Patents

Abstract

The invention discloses a valveless reversing device and a valveless reversing method, which are applied to a hydraulic system, wherein the device comprises the following components: a tank for containing hydraulic oil; the valve block comprises a plunger pump, a first check valve and a second check valve; the actuating mechanism is used for executing telescopic action and comprises a piston rod, a first cavity and a second cavity, wherein the first cavity and the second cavity are respectively positioned on two sides of a piston piece of the piston rod; the oil pump is used for pumping hydraulic oil and comprises a third one-way valve, a fourth one-way valve, a fifth one-way valve and a two-way pump; and the rotary driver is used for driving the plunger pump shaft of the plunger pump and the bidirectional pump shaft of the oil pump to rotate in at least two rotation directions. The valveless reversing device provided by the invention can replace the traditional control mode of adopting a direction control valve with high price, reduces the manufacturing cost and has good reliability.

Description

Valveless reversing device and method

Technical Field

The invention relates to a hydraulic system, in particular to a valveless reversing device and a valveless reversing method.

Background

In a hydraulic system, hydraulic oil flowing in a pipeline is often quickly changed, in this case, a high pressure peak value can be formed in the pipeline, the impact pressure can be 3-4 times higher than the normal working pressure, and elements, pipelines, instruments and the like in the hydraulic system are easily damaged, such as vibration, noise and loosening of connecting pieces caused by hydraulic impact, oil leakage and pressure change of a pressure valve are caused.

Due to the limitation of the performance of the ultrahigh pressure direction control element, domestic products often encounter a lot of difficulties in the aspect of realizing automatic control, for example, the quality of an electromagnet with high thrust is unreliable, the action of a valve core is influenced, the middle position function of the direction control valve can also have the problems of valve clamping and the like in the actual use process, and the cost for purchasing the direction control valve from abroad is too high, so that the defects exist.

Disclosure of Invention

The invention provides a valveless reversing device and a valveless reversing method, aiming at the problems of relative instability and high cost of the traditional directional control valve adopted in the existing hydraulic system in response to the impact situation of high-pressure hydraulic oil.

The technical scheme provided by the invention for the technical problem is as follows:

in one aspect, the present invention provides a valveless reversing device for use in a hydraulic system, the device comprising:

a tank for containing hydraulic oil;

the valve block comprises a plunger pump, a first one-way valve and a second one-way valve, the input end of the first one-way valve is communicated with the output end of the plunger pump, the second one-way valve is a hydraulic control one-way valve, the output end of the hydraulic control one-way valve is communicated with a pipeline on one side of the output end of the first one-way valve, and the input end of the hydraulic control one-way valve is communicated with the oil tank;

the actuating mechanism comprises a piston rod, a first cavity and a second cavity, wherein the first cavity and the second cavity are respectively positioned on two sides of a piston piece of the piston rod, and a communication end of the first cavity is communicated with a pipeline where an output end of the first one-way valve and an output end of the second one-way valve are positioned;

the oil pump is used for pumping hydraulic oil and comprises a third one-way valve, a fourth one-way valve, a fifth one-way valve and a bidirectional pump, wherein the input end of the third one-way valve is communicated with the oil tank, and the output end of the third one-way valve is communicated with the input end of the bidirectional pump; the input end of the fourth one-way valve is communicated with the first output end of the two-way pump, and the output end of the fourth one-way valve is communicated with the input end of the plunger pump; the input end of the fifth one-way valve is communicated with the second output end of the two-way pump, and the output end of the fifth one-way valve is communicated with the communication end of the second chamber; the bidirectional pump outputs hydraulic oil through the first output end in forward rotation and outputs hydraulic oil through the second output end in reverse rotation;

and the rotary driver is used for driving the plunger pump shaft of the plunger pump and the bidirectional pump shaft of the oil pump to rotate at least in two rotation directions.

According to the valveless reversing device, the plunger pump comprises a plunger pump body, and a low-pressure channel and a high-pressure channel which are arranged in the plunger pump body, wherein the input end of the low-pressure channel is communicated with the output end of the fourth one-way valve, and the output end of the high-pressure channel is communicated with the input end of the first one-way valve; the low-pressure channel is used for inputting low-pressure hydraulic oil; the high-pressure channel is used for outputting high-pressure hydraulic oil.

According to the valveless reversing device, the plunger pump body is also internally provided with an eccentric wheel, a plunger, an oil absorption one-way valve, a pressurizing cavity and an oil outlet one-way valve, and the eccentric wheel is connected with the plunger pump shaft to rotate under the driving of the plunger pump shaft; the output end of the low-pressure channel is communicated with the input end of the oil suction one-way valve;

the input end of the pressurizing cavity is communicated with the output end of the oil suction one-way valve; a sliding cavity structure for the plunger to reciprocate is further arranged in the pressurizing cavity, and at least one part of the cylindrical surface of the eccentric wheel is arranged on the reciprocating path of the plunger; the output end of the pressurizing cavity is communicated with the input end of the oil outlet one-way valve;

and the output end of the oil outlet one-way valve is communicated with the input end of the high-pressure channel.

According to the valveless reversing device, the low-pressure passage comprises a low-pressure main passage for introducing low-pressure hydraulic oil and two low-pressure branch passages for dividing the low-pressure hydraulic oil into two oil passages,

two sides of the plunger pump body are respectively provided with a group of pressurizing structures consisting of the oil suction one-way valve, the pressurizing cavity, the plunger and the oil outlet one-way valve, and the output ends of the two low-pressure branch channels are respectively communicated with the input end of the oil suction one-way valve on the corresponding side;

the high-pressure channel comprises two high-pressure sub-channels and a high-pressure main channel used for converging high-pressure hydraulic oil output by the two high-pressure sub-channels into one oil path, and the input ends of the two high-pressure sub-channels are respectively communicated with the output end of the oil outlet one-way valve on one corresponding side.

According to the valveless reversing device, the rotary driver is a bidirectional motor.

According to the valveless reversing device, the valve block further comprises a pressure sensor for sensing the pressure of the pipeline on which the output end side of the first one-way valve is located.

According to the valveless reversing device, the valve block further comprises a first overflow valve, a second overflow valve and a third overflow valve, wherein,

the input end of the first overflow valve is communicated with a pipeline on one side of the output end of the fourth one-way valve;

the input end of the second overflow valve is communicated with a pipeline between the output end of the plunger pump and the input end of the first check valve;

and the input end of the third overflow valve is communicated with a pipeline on which one side of the output end of the fifth one-way valve is positioned.

According to the valveless reversing device, the output ends of the first overflow valve, the second overflow valve and the third overflow valve are communicated with the oil tank.

In another aspect, the present invention also provides a valveless reversing method using the valveless reversing device as described above, the method comprising:

controlling the rotary driver to rotate forwards to drive the plunger pump shaft and the bidirectional pump to rotate so that a pipeline where the input end of the third one-way valve is located sucks oil from the oil tank;

the sucked hydraulic oil is input through the bidirectional pump and is output to the input end of the fourth one-way valve through the first output end;

the hydraulic oil is output through the fourth one-way valve, and when the pressure of a pipeline where the output end of the fourth one-way valve is located reaches a first pressure set value, the hydraulic oil enters the plunger pump to be pressurized to obtain high-pressure hydraulic oil; when the pressure of the pipeline where the input end of the plunger pump is located reaches a second pressure set value, the high-pressure hydraulic oil enters the first cavity through the first one-way valve.

According to the valveless reversing method described above, the method further comprises:

controlling the rotary driver to reversely rotate so as to drive the plunger pump shaft and the bidirectional pump to rotate, so that the pipeline where the input end of the third one-way valve is located sucks oil from the oil tank;

the sucked hydraulic oil is input through the bidirectional pump and is output to the fifth one-way valve through the second output end;

and when the pressure of a pipeline where the output end of the fifth one-way valve is located reaches a third pressure setting, the hydraulic oil enters the second cavity.

The technical scheme provided by the embodiment of the invention has the following beneficial effects:

the valveless reversing device provided by the invention adopts a structure mode that a plunger pump and an oil pump are connected in series, and both the plunger pump and the oil pump are driven by the same rotary driver. When the rotary driver rotates forwards, ultrahigh-pressure hydraulic oil can be output. When the rotary driver rotates reversely, the plunger pump idles without consuming the power of the rotary driver, and the pressure and the flow of the hydraulic oil output by the oil pump are increased, so that the contraction speed of a piston rod of the actuating mechanism can be increased, and the working efficiency is improved. Meanwhile, through the forward and reverse rotation of the rotary driver, the valveless reversing can be realized by the hydraulic control actuating mechanism, the whole device can effectively deal with the rapid reversing of the hydraulic oil and adapt to the running characteristic of ultrahigh-pressure hydraulic oil, the traditional control mode of adopting an expensive directional control valve is replaced, and the manufacturing cost is reduced. In addition, the invention reduces the number of hydraulic elements in the hydraulic system and is convenient to maintain. Under the condition of ultrahigh pressure, hydraulic oil leakage can be reduced, the reversing efficiency is increased, and the reliability is enhanced.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a block diagram of a unit structure of a valveless reversing device according to an embodiment of the present invention;

FIG. 2 is a schematic sectional structural view of a plunger pump according to the present invention;

FIG. 3 is a schematic view of a combination structure of the rotary actuator, the valve block and the oil pump according to the present invention at a first viewing angle;

FIG. 4 is a schematic view of a combination structure of the rotary actuator, the valve block and the oil pump according to the present invention at a second viewing angle;

FIG. 5 is a flow chart of a valveless reversing method in a first embodiment of the present invention as applied to a valveless reversing device;

fig. 6 is a flow chart of a valveless reversing method applied to a valveless reversing device according to a second embodiment of the present invention.

The labels in the figures illustrate:

100. a valveless reversing device;

1. an oil tank; 2. a rotary driver;

3. a valve block; 31. a plunger pump; 311. a plunger pump body; 312. a plunger pump shaft; 313. an eccentric wheel; 314. a plunger; 315. a low pressure channel; 316. an oil suction one-way valve; 317. a pressurization cavity; 318. an oil outlet one-way valve; 319. a high pressure channel; 32. a first overflow valve; 33. a second overflow valve; 34. a first check valve; 35. a pressure sensor; 36. a second one-way valve; 37. a third overflow valve;

4. an actuator; 41. a first chamber; 42. a second chamber; 43. a piston rod;

5. an oil pump; 51. a third check valve; 52. a fourth check valve; 53. a fifth check valve; 54. a bi-directional pump.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Referring to fig. 1 to 4, in which, fig. 1 is a block diagram of a unit structure of a valveless reversing device provided by the present invention in an embodiment; fig. 2 is a schematic sectional structural diagram of the plunger pump 31 provided in the present invention; FIG. 3 is a schematic view of a combination structure of the rotary actuator, the valve block and the oil pump according to the present invention at a first viewing angle; fig. 4 is a schematic view of a combination structure of the rotary actuator, the valve block and the oil pump provided by the invention at a second viewing angle. The valveless reversing device 100 is mainly applied to a hydraulic system and can comprise an oil tank 1, a rotary driver 2, a valve block 3, an actuating mechanism 4 and an oil pump 5, wherein the oil tank 1 is used for containing hydraulic oil, the rotary driver 2 is used for driving a pump body in the valve block 3 and the oil pump 5 to move, and the actuating mechanism 4 is used for executing telescopic actions under the action of the hydraulic oil, such as propping against and pulling back a target object. Here, the rotary drive 2 preferably employs a bidirectional motor. Here, the rotary shaft of the rotary actuator 2 is concentrically fitted and connected to the plunger pump shaft and the bidirectional pump shaft of the valve block 3. The rotary drive 2, the valve block 3 and the oil pump 5 can be connected and fixed in a bolt manner, wherein the valve block 3 is located between the rotary drive 2 and the oil pump 5.

As shown in fig. 1, the valve block 3 mainly includes a plunger pump 31, a first check valve 34 and a second check valve 36, wherein an input end of the first check valve 34 is communicated with an output end of the plunger pump 31, that is, hydraulic oil output by the plunger pump 31 flows into the input end of the first check valve 34 through a pipeline, and flows out from an output end of the first check valve 34 under the action of only allowing one-way flow. In the present invention, the second check valve 36 is a pilot operated check valve, the output end of which is communicated with the pipeline on the side where the output end of the first check valve 34 is located, and the input end of which is communicated with the oil tank 1, where the pilot operated check valve is a valve that can make the check valve reversely flow by controlling the fluid pressure, that is, the pilot operated check valve can reversely flow the hydraulic oil input from the output end of the pilot operated check valve into the oil tank 1 under a certain pressure condition.

The actuator 4 may include a first chamber 41, a second chamber 42 and a piston rod 43 capable of moving in a telescopic manner, wherein the first chamber 41 and the second chamber 42 are respectively disposed on two sides of a piston member of the piston rod 43, and hydraulic oil is injected into the first chamber 41 or the second chamber 42 to push the piston member to move and change the volumes of the first chamber 41 and the second chamber 42, and the piston member drives the piston rod 43 to move in the telescopic manner. Here, the communication end of the first chamber 41 communicates with the line in which the output end of the first check valve 34 is located. Therefore, after the hydraulic oil flowing out through the first check valve 34 enters the first chamber 41, it is presumed that the piston member of the piston rod 43 is moved so that the piston rod 43 is extended. Meanwhile, when the pipeline pressure on the side where the output end of the first check valve 34 is located is larger than a safety value, hydraulic oil can be released out through the arranged hydraulic control check valve, and damage to a pipeline or equipment due to overlarge pressure is prevented.

The oil pump 5 mainly includes a third check valve 51, a fourth check valve 52, a fifth check valve 53 and a bidirectional pump 54, wherein an input end of the third check valve 51 is communicated with the oil tank 1, and an output end of the third check valve is communicated with an input end of the bidirectional pump 54, so that the bidirectional pump 54 is driven by the rotation of the rotary driver 2 to pump hydraulic oil out of the oil tank 1 by using a pipeline on which one side of the input end of the third check valve 51 is located.

The bidirectional pump 54 includes a first output through which hydraulic oil is output in the forward rotation and a second output through which hydraulic oil is output in the reverse rotation. The input of the fourth check valve 52 communicates with a first output of a bi-directional pump 54, the output of which communicates with the input of the plunger pump 31. And the input of the fifth check valve 53 communicates with a second output of the bi-directional pump 54 and with a communicating end of the output second chamber 42.

When the rotary actuator 2 drives the bidirectional pump 54 to rotate forward, the hydraulic oil is delivered to the direction of the fourth one-way valve 52 by the bidirectional pump 54, and then pressurized and delivered to the first chamber 41 through the plunger pump 31, meanwhile, because the pressure of the hydraulic oil in the second chamber 42 is small, the piston member can compress the volume of the second chamber 42 under the condition that the pressure in the first chamber 41 is increased, accordingly, the hydraulic oil in the second chamber 42 can flow to a pipeline on which the output end side of the fifth one-way valve 53 is located, and when the pipeline pressure is greater than a safety value, the pressure can be relieved by outputting a part of the hydraulic oil.

When the rotary actuator 2 drives the two-way pump 54 to rotate reversely, the hydraulic oil is delivered to the direction of the fifth one-way valve 53 by the two-way pump 54 and then enters the second chamber 42 through the corresponding pipeline, meanwhile, because the pressure of the hydraulic oil in the first chamber 41 is small, the piston member can compress the volume of the first chamber 41 under the condition that the pressure in the second chamber 42 is increased, accordingly, the hydraulic oil in the first chamber 41 can flow to the pipeline on which the output end side of the first one-way valve 34 is located, and when the pipeline pressure is greater than the safety value, the hydraulic control one-way valve can be used for releasing the pressure in a mode that a part of the oil pressure is output to the oil tank 1.

In the present embodiment, the hydraulic oil in the second chamber 42 is prevented from flowing back toward the plunger pump 31 due to the presence of the first check valve 34. Meanwhile, when the rotary actuator 2 is rotated reversely, the output hydraulic oil of the oil pump 5 no longer passes through the fourth check valve 52 and enters the low-pressure passage of the plunger pump 31, and the plunger pump 31 idles so that the plunger pump 31 no longer outputs high-pressure hydraulic oil.

The valveless reversing device 100 provided by the invention adopts a structure mode that a plunger pump 31 and an oil pump 5 are connected in series, and both are driven by the same rotary driver 2. When the rotary driver 2 rotates forwards, ultrahigh-pressure hydraulic oil is output. When the rotary actuator 2 rotates reversely, the plunger pump 31 idles without consuming power of the rotary actuator 2, and the pressure and flow rate of the hydraulic oil output by the oil pump 5 are increased, so that the contraction speed of the piston rod 43 of the actuator 4 can be increased, and the working efficiency can be improved. Meanwhile, through the forward and reverse rotation of the rotary driver, the valveless reversing can be realized by the hydraulic control actuator 4, the whole device can effectively deal with the rapid reversing of the hydraulic oil and adapt to the running characteristic of ultrahigh-pressure hydraulic oil, the traditional control mode of adopting an expensive directional control valve is replaced, and the manufacturing cost is reduced. In addition, the invention reduces the number of hydraulic elements in the hydraulic system and is convenient to maintain. Under the condition of ultrahigh pressure, hydraulic oil leakage can be reduced, the reversing efficiency is increased, and the reliability is enhanced.

In some specific application examples, the valve block 3 may further include a first relief valve 32, a second relief valve 33, and a third relief valve 37, wherein:

the input end of the first relief valve 32 communicates with the pipe line on the output end side of the fourth check valve 52, so that the first relief valve 32 can pressure-regulate the hydraulic oil in the pipe line between the fourth check valve 52 and the plunger pump 31. The input end of the second relief valve 33 communicates with the line between the output end of the plunger pump 31 and the input end of the first check valve 34, and thus the second relief valve 33 can pressure-regulate the hydraulic oil in the line between the plunger pump 31 and the first check valve 34. The input end of the third relief valve 37 is communicated with the pipeline on the output end side of the fifth check valve 53, so that the third relief valve 37 can regulate the pressure of the hydraulic oil in the pipeline between the fifth check valve 53 and the second chamber 42. Here, the hydraulic oil flows to the input end of the respective component if and only if the respective relief valve is to correspond to the pressure regulating value of the hydraulic oil in the line by the respective value.

It is understood that the output ends of the first relief valve 32, the second relief valve 33 and the third relief valve 37 can be communicated with the oil tank 1, so that a part of hydraulic oil in the pipeline can be discharged to the oil tank 1 when the relief regulation is performed.

In addition, the valve block 3 may further include a pressure sensor 35 for sensing a pressure of the pipeline on the output side of the first check valve 34, so as to obtain a pressure value of hydraulic oil in the pipeline in real time, which is beneficial to realizing production monitoring and/or safety monitoring.

Referring to fig. 2 and fig. 1, the plunger pump 31 may specifically include a plunger pump body 311, and a low pressure passage 315 and a high pressure passage 319 disposed in the plunger pump body 311, wherein an input end of the low pressure passage 315 is communicated with an output end of the fourth check valve 52, and an output end of the high pressure passage 319 is communicated with an input end of the first check valve 34. The low pressure passage 315 is used for inputting low pressure hydraulic oil, and the high pressure passage 319 is used for outputting high pressure hydraulic oil.

The plunger pump body 311 is further provided with an eccentric wheel 313, a plunger 314, an oil suction check valve 316, a pressurizing cavity 317 and an oil outlet check valve 318, and the eccentric wheel 313 is connected with the plunger pump shaft 312 to rotate under the driving of the plunger pump shaft 312. And the output end of the low pressure passage 315 is communicated with the input end of the oil suction check valve 316, so that the hydraulic oil output through the fourth check valve 52 can enter the oil suction check valve 316 through the low pressure passage 315.

The input end of the pressurizing cavity 317 is communicated with the output end of the oil suction one-way valve 316, in addition, a sliding cavity structure for the reciprocating motion of the plunger 314 is arranged in the pressurizing cavity 317, at least one part of the cylindrical surface of the eccentric wheel 313 is arranged on the reciprocating motion path of the plunger 314, the output end of the pressurizing cavity 317 is communicated with the input end of the oil outlet one-way valve 318, and the output end of the oil outlet one-way valve 318 is communicated with the input end of the high-pressure channel 319. Therefore, after the hydraulic oil enters the pressurizing cavity 317 through the low-pressure passage 315 and the oil suction check valve 316 in sequence, the plunger 314 can be abutted to the rotation area of the eccentric wheel 313, the rotating driver 2 drives the plunger pump shaft 312 to rotate, the rotating plunger pump shaft 312 can further drive the eccentric wheel 313 to rotate, the rotating eccentric wheel 313 can abut the plunger 314 extending into the rotation area back to the pressurizing cavity 317, that is, the plunger 314 is pushed to the direction away from the plunger pump shaft 312, and the pressurization of the hydraulic oil is realized. The pressurized hydraulic oil may flow through the outlet check valve 318 to the high pressure passage 319.

Here, the low pressure passage 315 may include a low pressure main passage for introducing low pressure hydraulic oil and two low pressure branch passages for dividing the low pressure hydraulic oil into two oil passages, and accordingly, a set of pressurizing structures composed of an oil suction check valve 316, a pressurizing chamber 317, a plunger 314, and an oil outlet check valve 318 are provided at both side portions of the plunger pump body 311, and output ends of the two low pressure branch passages are respectively communicated with input ends of the oil suction check valve 316 at a corresponding side. The high-pressure channel 319 comprises two high-pressure sub-channels and a high-pressure main channel for merging the high-pressure hydraulic oil output from the two high-pressure sub-channels into one oil path, and the input ends of the two high-pressure sub-channels are respectively communicated with the output end of the oil outlet check valve 318 on the corresponding side. More specifically, the low-pressure main channel is perpendicular to the two low-pressure sub-channels, respectively, and similarly, the high-pressure main channel is perpendicular to the two high-pressure sub-channels, respectively, the high-pressure main channel being on an extension of the low-pressure main channel, and the high-pressure sub-channels being parallel to the low-pressure sub-channels. The pressurized chamber 317 includes a main chamber body parallel to the low pressure main channel, a sliding chamber structure perpendicular to the main chamber body. The plunger pump shaft 312 is disposed at a middle position of the plunger pump body 311.

Under the structure, after entering the low-pressure main channel, the hydraulic oil is divided into two hydraulic oil flows to the oil suction one-way valve 316 on the corresponding side respectively, the hydraulic oil is pressurized under the combined action of the pressurizing cavity 317, the plunger 314, the eccentric wheel 313 and the plunger pump shaft 312, then the hydraulic oil flows out from the corresponding oil outlet one-way valve 318 and flows out through the corresponding high-pressure sub-channel, and finally the ultrahigh-pressure hydraulic oil is gathered by the high-pressure main channel and is output.

It is understood that in a variation of this embodiment, the plunger pump body 311 may only include a set of pressurizing structures consisting of the oil suction check valve 316, the pressurizing chamber 317, the plunger 314 and the oil outlet check valve 318, and accordingly, the low pressure passage 315 may be directly communicated with the oil suction check valve 316, and the high pressure passage 319 may be directly communicated with the oil outlet check valve 318. Therefore, in this structure, after entering the low pressure passage 315, the hydraulic oil can directly flow to the oil suction check valve 316, and under the combined action of the pressurization cavity 317, the plunger 314, the eccentric wheel 313 and the plunger pump shaft 312, the hydraulic oil is pressurized, and then flows out of the oil outlet check valve 318 and is directly output by the high pressure passage 319.

It will be appreciated that when the rotary drive 2 is deactivated, the high pressure oil in the first chamber 41 may be locked by the first check valve 34 and the second check valve 36, thereby performing a pressure maintaining function for the first chamber 41.

Referring to fig. 5, a flow chart of a valveless reversing method applied to a valveless reversing device in a first embodiment is provided for the present invention. The valveless reversing method of the present embodiment performs actions by controlling each element or component in the above-mentioned valveless reversing device to realize corresponding functions, and specifically, may include the following steps:

s101: and controlling the rotary driver to rotate positively to drive the plunger pump shaft and the bidirectional pump to rotate so that the pipeline where the input end of the third one-way valve is located absorbs oil from the oil tank.

S102: the sucked hydraulic oil is input through the bidirectional pump and output to the input end of the fourth one-way valve through the first output end.

S103: the hydraulic oil is output through the fourth one-way valve, and when the pressure of a pipeline where the output end of the fourth one-way valve is located reaches a first pressure set value, the hydraulic oil enters the plunger pump to be pressurized to obtain high-pressure hydraulic oil; when the pressure of the pipeline where the input end of the plunger pump is located reaches a second pressure set value, high-pressure hydraulic oil enters the first cavity through the first one-way valve. Here, the first pressure set value may be determined according to a line pressure value allowed by the first relief valve; the second pressure setting may be determined in accordance with a line pressure value allowed by the second excess flow valve as described above.

In this embodiment, the high-pressure hydraulic oil is delivered to the first cavity by controlling the rotary driver to rotate forward, so that the piston rod is abutted to the maximum stroke direction, i.e., the piston rod is extended out.

Referring to fig. 6, a flow chart of a valveless reversing method applied to a valveless reversing device in a second embodiment is provided for the present invention. The present embodiment may include a step of controlling the reverse rotation of the rotary driver based on the first embodiment, and specifically may include the following steps:

s201: controlling the rotary driver to rotate reversely to drive the plunger pump shaft and the bidirectional pump to rotate so that the pipeline where the input end of the third one-way valve is located absorbs oil from the oil tank;

s202: the sucked hydraulic oil is input through the bidirectional pump and output to the fifth one-way valve through the second output end;

s203: and when the pressure of the pipeline where the output end of the fifth one-way valve is located reaches a third pressure set value, the hydraulic oil enters the second cavity. Here, the third pressure set point may be determined based on a line pressure value allowed by the third relief valve.

In this embodiment, the hydraulic oil is delivered to the second cavity by controlling the rotary actuator to rotate reversely, so that the piston rod is abutted to the minimum stroke direction, that is, the piston rod retracts.

With reference to fig. 5 and 6, the valveless reversing method provided by the present invention employs a dual-pump tandem configuration of a plunger pump and an oil pump, both of which are driven by the same rotary drive. The ultrahigh pressure hydraulic oil is output by controlling the rotary driver to rotate forwards. By controlling the reverse rotation of the rotary driver, the power of the rotary driver is not consumed when the plunger pump idles, the pressure and the flow of hydraulic oil output by the oil pump are increased, the contraction speed of a piston rod of the actuating mechanism can be increased, and the working efficiency is improved. Meanwhile, through the forward and reverse rotation of the rotary driver, the valveless reversing can be realized by the hydraulic control actuating mechanism, the whole device can effectively deal with the rapid reversing of the hydraulic oil and adapt to the running characteristic of ultrahigh-pressure hydraulic oil, the traditional control mode of adopting an expensive directional control valve is replaced, and the manufacturing cost is reduced. In addition, the invention reduces the number of hydraulic elements in the hydraulic system and is convenient to maintain. Under the condition of ultrahigh pressure, hydraulic oil leakage can be reduced, the reversing efficiency is increased, and the reliability is enhanced.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims (10)

1. A valveless reversing device applied to a hydraulic system is characterized by comprising:

a tank for containing hydraulic oil;

the valve block comprises a plunger pump, a first one-way valve and a second one-way valve, the input end of the first one-way valve is communicated with the output end of the plunger pump, the second one-way valve is a hydraulic control one-way valve, the output end of the hydraulic control one-way valve is communicated with a pipeline on one side of the output end of the first one-way valve, and the input end of the hydraulic control one-way valve is communicated with the oil tank;

the actuating mechanism comprises a piston rod, a first cavity and a second cavity, wherein the first cavity and the second cavity are respectively positioned on two sides of a piston piece of the piston rod, and a communication end of the first cavity is communicated with a pipeline where an output end of the first one-way valve and an output end of the second one-way valve are positioned;

the oil pump is used for pumping hydraulic oil and comprises a third one-way valve, a fourth one-way valve, a fifth one-way valve and a bidirectional pump, wherein the input end of the third one-way valve is communicated with the oil tank, and the output end of the third one-way valve is communicated with the input end of the bidirectional pump; the input end of the fourth one-way valve is communicated with the first output end of the two-way pump, and the output end of the fourth one-way valve is communicated with the input end of the plunger pump; the input end of the fifth one-way valve is communicated with the second output end of the two-way pump, and the output end of the fifth one-way valve is communicated with the communication end of the second chamber; the bidirectional pump outputs hydraulic oil through the first output end in forward rotation and outputs hydraulic oil through the second output end in reverse rotation;

and the rotary driver is used for driving the plunger pump shaft of the plunger pump and the bidirectional pump shaft of the oil pump to rotate at least in two rotation directions.

2. The valveless reversing device according to claim 1, wherein the plunger pump comprises a plunger pump body, and a low-pressure passage and a high-pressure passage which are arranged in the plunger pump body, wherein an input end of the low-pressure passage is communicated with an output end of the fourth check valve, and an output end of the high-pressure passage is communicated with an input end of the first check valve; the low-pressure channel is used for inputting low-pressure hydraulic oil; the high-pressure channel is used for outputting high-pressure hydraulic oil.

3. The valveless reversing device according to claim 2, wherein an eccentric wheel, a plunger, an oil suction check valve, a pressurizing cavity and an oil outlet check valve are further arranged in the plunger pump body, and the eccentric wheel is connected with the plunger pump shaft to rotate under the driving of the plunger pump shaft; the output end of the low-pressure channel is communicated with the input end of the oil suction one-way valve;

the input end of the pressurizing cavity is communicated with the output end of the oil suction one-way valve; a sliding cavity structure for the plunger to reciprocate is further arranged in the pressurizing cavity, and at least one part of the cylindrical surface of the eccentric wheel is arranged on the reciprocating path of the plunger; the output end of the pressurizing cavity is communicated with the input end of the oil outlet one-way valve;

and the output end of the oil outlet one-way valve is communicated with the input end of the high-pressure channel.

4. The valveless reversing device according to claim 3, wherein the low-pressure passage includes a low-pressure main passage for introducing low-pressure hydraulic oil and two low-pressure branch passages for dividing the low-pressure hydraulic oil into two oil passages,

two sides of the plunger pump body are respectively provided with a group of pressurizing structures consisting of the oil suction one-way valve, the pressurizing cavity, the plunger and the oil outlet one-way valve, and the output ends of the two low-pressure branch channels are respectively communicated with the input end of the oil suction one-way valve on the corresponding side;

the high-pressure channel comprises two high-pressure sub-channels and a high-pressure main channel used for converging high-pressure hydraulic oil output by the two high-pressure sub-channels into one oil path, and the input ends of the two high-pressure sub-channels are respectively communicated with the output end of the oil outlet one-way valve on one corresponding side.

5. The valveless reversing device according to any one of claims 1 to 4, wherein the rotary drive is a bidirectional motor.

6. The valveless reversing device according to any one of claims 1 to 4, wherein the valve block further comprises a pressure sensor for sensing a line pressure at an output side of the first one-way valve.

7. The valveless reversing device according to any one of claims 1 to 4, wherein the valve block further comprises a first relief valve, a second relief valve, and a third relief valve, wherein,

the input end of the first overflow valve is communicated with a pipeline on one side of the output end of the fourth one-way valve;

the input end of the second overflow valve is communicated with a pipeline between the output end of the plunger pump and the input end of the first check valve;

and the input end of the third overflow valve is communicated with a pipeline on which one side of the output end of the fifth one-way valve is positioned.

8. The valveless reversing device according to claim 7, wherein output ends of the first overflow valve, the second overflow valve and the third overflow valve are all communicated with the oil tank.

9. A method of valveless reversing using the valveless reversing device according to any one of claims 1 to 8, said method comprising:

controlling the rotary driver to rotate forwards to drive the plunger pump shaft and the bidirectional pump to rotate so that a pipeline where the input end of the third one-way valve is located sucks oil from the oil tank;

the sucked hydraulic oil is input through the bidirectional pump and is output to the input end of the fourth one-way valve through the first output end;

the hydraulic oil is output through the fourth one-way valve, and when the pressure of a pipeline where the output end of the fourth one-way valve is located reaches a first pressure set value, the hydraulic oil enters the plunger pump to be pressurized to obtain high-pressure hydraulic oil; when the pressure of the pipeline where the input end of the plunger pump is located reaches a second pressure set value, the high-pressure hydraulic oil enters the first cavity through the first one-way valve.

10. The valveless reversing method of claim 9, further comprising:

controlling the rotary driver to reversely rotate so as to drive the plunger pump shaft and the bidirectional pump to rotate, so that the pipeline where the input end of the third one-way valve is located sucks oil from the oil tank;

the sucked hydraulic oil is input through the bidirectional pump and is output to the fifth one-way valve through the second output end;

and when the pressure of a pipeline where the output end of the fifth one-way valve is located reaches a third pressure setting, the hydraulic oil enters the second cavity.

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