CN114033762A - Variable pump flow control system, variable pump flow control method and main arm oil cylinder control system - Google Patents

Variable pump flow control system, variable pump flow control method and main arm oil cylinder control system Download PDF

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Publication number
CN114033762A
CN114033762A CN202111347172.2A CN202111347172A CN114033762A CN 114033762 A CN114033762 A CN 114033762A CN 202111347172 A CN202111347172 A CN 202111347172A CN 114033762 A CN114033762 A CN 114033762A
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China
Prior art keywords
oil
valve
pump
variable
port
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CN202111347172.2A
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Chinese (zh)
Inventor
刘国良
石伟
赵俊波
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Hunan Sinoboom Intelligent Equipment Co Ltd
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Hunan Sinoboom Intelligent Equipment Co Ltd
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Priority to CN202111347172.2A priority Critical patent/CN114033762A/en
Publication of CN114033762A publication Critical patent/CN114033762A/en
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/08—Servomotor systems without provision for follow-up action; Circuits therefor with only one servomotor
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
    • F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
    • F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
    • F15B13/0401—Valve members; Fluid interconnections therefor
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
    • F15B13/16—Special measures for feedback, e.g. by a follow-up device
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205—Systems with pumps
    • F15B2211/2053—Type of pump
    • F15B2211/20538—Type of pump constant capacity
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/405—Flow control characterised by the type of flow control means or valve

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fluid-Pressure Circuits (AREA)

Abstract

A variable pump flow control system, a control method and a main arm oil cylinder control system are provided, wherein the variable pump flow control system comprises: an oil inlet of the proportional valve is connected with an oil outlet of the variable pump, and the oil outlet is connected with an oil pressure feedback end of the variable pump; the first oil port is connected with the oil outlet of the proportional valve, the second oil port and the third oil port are used for adjusting the operation state of the main arm telescopic oil cylinder, and the fourth oil port is used for connecting a main oil tank; the first oil port is connected with an oil outlet of the proportional valve; and the stop valve is connected between the second oil port of the flow valve and the fourth oil port of the first reversing valve. The invention can realize the control of the main arm telescopic oil cylinder normally driven by the variable displacement pump; through the cut-off valve, the cut-off flow valve can drain oil to the main oil cylinder at the starting stage of the variable pump, so that the oil pressure feedback end of the variable pump can obtain accurate oil pressure, the output flow can be correctly adjusted by the variable pump, and output flow fluctuation is prevented.

Description

Variable pump flow control system, variable pump flow control method and main arm oil cylinder control system
Technical Field
The invention belongs to the field of engineering equipment, and particularly relates to a variable pump flow control system, a variable pump flow control method and a main arm oil cylinder control system.
Background
When the main arm needs to be operated to perform telescopic motion, the variable pump needs to be started to output hydraulic oil to drive the main arm telescopic oil cylinder to work, but when the variable pump is just started, the piston rod of the main arm telescopic oil cylinder cannot be pushed to move immediately, and the piston rod can be pushed to move finally along with the gradual increase of the driving force of the main arm telescopic oil cylinder. In the process, the traditional hydraulic control system cannot feed pressure back to the oil pressure feedback end of the variable pump well, so that the output flow of the variable pump shakes, and the main arm support shakes when being extended and retracted to start.
Disclosure of Invention
The present invention is directed to solving at least one of the problems of the prior art. Therefore, the invention provides a variable pump flow control system, which solves the problem of output flow jitter when a variable pump is started. The invention also provides a control method and a main arm oil cylinder control system.
According to a first aspect of the invention, a variable displacement pump flow control system comprises:
an oil inlet of the proportional valve is connected with an oil outlet of the variable pump, and the oil outlet is connected with an oil pressure feedback end of the variable pump;
the first reversing valve is provided with a first oil port, a second oil port, a third oil port and a fourth oil port, the first oil port of the first reversing valve is connected with the oil outlet of the proportional valve, the second oil port and the third oil port are used for adjusting the operation state of the main arm telescopic oil cylinder, and the fourth oil port is used for connecting a main oil tank;
the flow valve is provided with a first oil port and a second oil port, and the first oil port of the flow valve is connected with the oil outlet of the proportional valve;
and the stop valve is connected between the second oil port of the flow valve and the fourth oil port of the first reversing valve.
The variable pump flow control system provided by the embodiment of the invention at least has the following technical effects: the proportional valve, the first reversing valve and the flow valve can realize the control of the variable pump for normally driving the main arm telescopic oil cylinder; through the cut-off valve, the cut-off flow valve can run oil to the main oil cylinder at the starting stage of the variable pump, so that the oil pressure feedback end of the variable pump can obtain accurate oil pressure, the output flow can be correctly adjusted by the variable pump, and output flow fluctuation caused by inaccurate adjustment of the output flow is reduced.
According to some embodiments of the invention, the variable displacement pump comprises:
an oil inlet of the pump main body is connected with the main oil tank, and an oil outlet of the pump main body is connected with an oil inlet of the proportional valve;
the left position of the load sensitive valve is connected with an oil outlet of the pump main body, the right position of the load sensitive valve is connected with an oil outlet of the proportional valve, and a working oil port is connected with a rodless cavity of a variable oil cylinder of the pump main body;
and the pressure stop valve is connected between an oil outlet of the pump main body and the rodless cavity of the variable oil cylinder.
According to some embodiments of the invention, the variable pump flow control system further comprises a check valve connected between the oil outlet of the proportional valve and the first port of the flow valve.
According to some embodiments of the invention, the above variable pump flow control system further comprises a relief valve connected between an oil outlet of the variable pump and the main oil tank.
According to some embodiments of the present invention, the variable displacement pump flow control system further includes a balance valve connected between the second oil port and the third oil port of the first directional control valve and the main arm telescopic cylinder.
According to some embodiments of the invention, the shutoff valve element is a second direction valve.
The control method according to the embodiment of the second aspect of the present invention is applied to the variable pump flow control system as described above, and includes the steps of:
confirming the running state of the variable pump, wherein the running state comprises a starting state, a working state and a stopping state;
confirming the operating state of a main arm telescopic oil cylinder, wherein the operating state comprises a piston rod pushing state and a piston rod static state;
and if the variable pump is in the starting state and the main arm telescopic oil cylinder is in the piston rod static state, closing the stop valve.
The control method provided by the embodiment of the invention at least has the following technical effects: when the variable pump is started and the piston rod of the main arm telescopic oil cylinder is not pushed, the stop valve is closed, so that accurate feedback oil pressure can be obtained at the starting stage of the variable pump, the working state of the variable pump can be accurately adjusted, and long-time jitter of the output flow of the variable pump is avoided.
According to some embodiments of the invention, the control method further comprises the steps of:
and if the variable pump is in the working state or the stop state, opening the stop valve.
The main arm oil cylinder control system according to the third aspect of the invention comprises a main oil tank, a variable pump and the variable pump flow control system connected with the variable pump.
The main arm oil cylinder control system provided by the embodiment of the invention at least has the following technical effects: by adding the variable pump flow control system, the shaking phenomenon of the main arm support when the main arm support is extended out and retracted and started can be effectively prevented, so that a series of problems caused by shaking of the arm support are avoided.
According to some embodiments of the invention, the variable displacement pump comprises:
an oil inlet of the pump main body is connected with the main oil tank, and an oil outlet of the pump main body is connected with an oil inlet of the proportional valve;
the left position of the load sensitive valve is connected with an oil outlet of the pump main body, the right position of the load sensitive valve is connected with an oil outlet of the proportional valve, and a working oil port is connected with a rodless cavity of a variable oil cylinder of the pump main body;
and the pressure stop valve is connected between an oil outlet of the pump main body and the rodless cavity of the variable oil cylinder.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Drawings
The above and additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 is a hydraulic diagram of a variable displacement pump flow control system according to an embodiment of the present invention.
Reference numerals;
a proportional valve 110, a first direction changing valve 120, a flow valve 130, a cut-off valve element 140, a one-way valve 150, a safety valve 160, a balance valve 170,
A variable displacement pump 200, a pump body 210, a variable displacement cylinder 211, a load sensitive valve 220, a pressure stop valve 230,
A main arm telescopic oil cylinder 300,
A main oil tank 400.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.
In the description of the present invention, if there are first, second, third, fourth, etc. described only for the purpose of distinguishing technical features, they are not to be interpreted as indicating or implying relative importance or implying number of indicated technical features or implying precedence of indicated technical features.
In the description of the present invention, unless otherwise explicitly defined, terms such as arrangement, connection and the like should be broadly construed, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the detailed contents of the technical solutions.
A variable pump flow control system according to an embodiment of the first aspect of the invention is described with reference to fig. 1.
The variable pump flow control system according to the embodiment of the invention comprises: proportional valve 110, first reversing valve 120, flow valve 130, and stop valve element 140.
An oil inlet of the proportional valve 110 is connected with an oil outlet of the variable pump 200, and the oil outlet is connected with an oil pressure feedback end of the variable pump 200;
the first reversing valve 120 is provided with a first oil port, a second oil port, a third oil port and a fourth oil port, the first oil port of the first reversing valve 120 is connected with the oil outlet of the proportional valve 110, the second oil port and the third oil port are used for adjusting the operation state of the main arm telescopic oil cylinder 300, and the fourth oil port is used for connecting the main oil tank 400;
the flow valve 130 is provided with a first oil port and a second oil port, and the first oil port of the flow valve 130 is connected with the oil outlet of the proportional valve 110;
and a cut-off valve element 140 connected between the second port of the flow valve 130 and the fourth port of the first direction valve 120.
Referring to fig. 1, when the variable displacement pump 200 is started and the main arm is not operated, and the proportional valve 110 is in a closed state, a part of the flow output by the variable displacement pump 200 is blocked at the inlet of the proportional valve 110, and another part of the flow flows to the left position of the load sensitive valve 220 and the left position of the pressure cut-off valve 230. When the pressure at the left position of the load sensitive valve 220 is greater than the pre-tightening force of the spring at the right position of the load sensitive valve, the oil acts on the left position of the load sensitive valve 220 to move the valve core of the load sensitive valve 220 to the right. During the process of rightward movement of the spool, the spool valve of the load-sensitive valve 220 opens a passage, so that the oil at the outlet of the variable pump 200 is communicated with the rodless cavity of the variable cylinder 211, thereby pushing the piston rod of the variable cylinder 211 to move, and rotating the inclination angle of the swash plate of the pump body 210 of the variable pump 200 counterclockwise, so that the displacement of the variable pump 200 approaches zero, and at this time, the variable pump 200 is in a low-pressure standby condition.
The actual time for reaching the low-voltage standby working condition is short, and then the main arm can be operated to work. When the main arm telescopic cylinder 300 is operated to work, the proportional valve 110 is opened, and the first reversing valve 120 is powered on at the left position (namely, oil can be input into the rodless cavity of the main arm telescopic cylinder 300 through the proportional valve 110). When the main arm is operated initially, the current of the proportional valve 110 is relatively small initially, and the opening degree of the corresponding valve port is relatively small, so that in this period of time, the pressure in the rodless cavity of the main arm telescopic oil cylinder 300 cannot push the piston rod of the main arm telescopic oil cylinder 300 to move, that is, no oil flows, and at this time, the static equilibrium state is achieved. In the static equilibrium state, the pressure in the rodless chamber of the main arm telescopic cylinder 300 will flow into the flow valve 130 and the inlet (i.e., the oil pressure feedback end, such as the LS port shown in fig. 1) of the spring chamber at the right of the load sensitive valve 220 through the first oil port of the first directional valve 120. The load sensitive valve 220 needs to adjust the output flow of the variable pump 200 according to the pressure input by the LS port, and if oil continuously flows into the main oil tank 400 through the flow valve 130, the pressure input by the feedback of the LS port is inevitably smaller than the actual pressure, so that the load sensitive valve 220 makes an error in adjusting the variable pump 200, and the condition of output flow jitter of the variable pump 200 is caused. Here, the oil path of the flow valve 130 flowing into the main oil tank 400 is directly stopped by using the stop valve 140, so that all the pressure fed back from the first oil port of the first direction valve 120 can be completely pressurized to the LS port of the load sensitive valve 220, and the load sensitive valve 220 can obtain a correct pressure value, thereby stably controlling the output flow of the variable displacement pump 200.
It should be noted that the flow valve 130 is used to timely release the pressure in the pipeline when the engine is shut down, so as to prevent the pressure in the pipeline from being in a closed state all the time. In addition, the stop valve element 140 is mainly used to close at the initial stage of starting the variable displacement pump 200 and operating the main arm, and is always in an open state in the subsequent normal operation, so as to ensure the normal operation of the whole pipeline.
According to the variable pump flow control system provided by the embodiment of the invention, the proportional valve 110, the first reversing valve 120 and the flow valve 130 can control the main arm telescopic oil cylinder 300 normally driven by the variable pump 200; through the cut-off valve element 140, the cut-off flow valve 130 can drain oil to the master cylinder at the starting stage of the variable pump 200, so that the oil pressure feedback end of the variable pump 200 can obtain accurate oil pressure, the variable pump 200 can be ensured to correctly adjust the output flow, and output flow fluctuation caused by inaccurate adjustment of the output flow is reduced.
In some embodiments of the present invention, variable displacement pump 200 comprises: a pump body 210, a load sensitive valve 220, and a pressure shut-off valve 230. An oil inlet of the pump main body 210 is connected with the main oil tank 400, and an oil outlet of the pump main body is connected with an oil inlet of the proportional valve 110; the left position of the load sensitive valve 220 is connected with an oil outlet of the pump main body 210, the right position of the load sensitive valve is connected with an oil outlet of the proportional valve 110, and a working oil port is connected with a rodless cavity of a variable oil cylinder 211 of the pump main body 210; and a pressure cutoff valve 230 connected between an oil outlet of the pump main body 210 and a rodless chamber of the variable cylinder 211.
The load sensing valve 220 and the pressure cutoff valve 230 can adjust the flow output state of the pump main body 210 by adjusting the operation state of the piston rod of the variable cylinder 211, and the adjustment of the operation of the piston rod is performed by inputting oil into the rodless chamber. The load sensitive valve 220 is mainly used in the normal operation process, the spring pretightening force setting value of the right position of the load sensitive valve is usually smaller, for example, the spring pretightening force setting value can be set to be 20bar, when the left position of the load sensitive valve 220 is pressurized to exceed the sum of the pretightening force and the LS opening pressure, the valve core can be pushed to move to the right, and therefore the purpose of controlling the opening of the valve according to the pressure can be achieved. The spring preload setting value of the pressure stop valve 230 is much larger than the preload of the spring in the load sensitive valve 220, for example, 220bar may be set, when the pressurization at the left position of the pressure stop valve 230 is larger than 220bar, the pressure stop valve 230 may push the valve core to move right, so that the piston rod of the variable cylinder 211 pushes the swash plate of the variable pump 200 to rotate until the flow output of the pump main body 210 of the variable pump 200 is nearly zero, thereby achieving a high-pressure standby state.
In some embodiments of the present invention, the variable displacement pump flow control system further comprises a check valve 150 connected between the outlet of the proportional valve 110 and the first port of the flow valve 130. The check valve 150 can prevent oil from flowing reversely, so that the safety of the pipeline is ensured.
In some embodiments of the present invention, the variable pump flow control system further comprises a relief valve 160 connected between the outlet of the variable pump 200 and the main tank 400. The safety valve 160 may perform pressure relief when a failure occurs in the pipeline, which causes the pressure at the output port of the variable displacement pump 200 to continuously rise, so as to ensure the safety of the pipeline, and the discharged oil may be directly discharged back to the main oil tank 400.
In some embodiments of the present invention, the variable displacement pump flow control system further comprises a balance valve 170 connected between the second port and the third port of the first directional control valve 120 and the main arm telescopic cylinder 300. The load can be balanced by the balancing valve 170 to ensure stable operation of the main arm.
In some embodiments of the present invention, the shutoff valve element 140 is a second reversing valve. The use of a reversing valve can have a stopping effect. The stop valve can also directly adopt a common electromagnetic valve.
The control method according to the embodiment of the second aspect of the present invention is applied to the variable pump flow control system as described above, and includes the steps of:
confirming the running state of the variable pump 200, wherein the running state comprises a starting state, a working state and a stopping state;
confirming the operation state of the main arm telescopic cylinder 300, wherein the operation state comprises a piston rod pushing state and a piston rod static state;
if the variable displacement pump 200 is in the activated state and the main arm telescopic cylinder 300 is in the piston rod stationary state, the cut-off valve element 140 is closed.
Referring to fig. 1, when the main arm telescopic cylinder 300 is operated, the proportional valve 110 is opened, and the first direction valve 120 is left powered (i.e., oil can be input into the rodless cavity of the main arm telescopic cylinder 300 through the proportional valve 110). When the main arm is operated initially, the current of the proportional valve 110 is relatively small initially, and the opening degree of the corresponding valve port is relatively small, so that in this period of time, the pressure in the rodless cavity of the main arm telescopic oil cylinder 300 cannot push the piston rod of the main arm telescopic oil cylinder 300 to move, that is, no oil flows, and at this time, the static equilibrium state is achieved. In the static equilibrium state, the pressure in the rodless chamber of the main arm telescopic cylinder 300 will flow into the flow valve 130 and the inlet (i.e., the oil pressure feedback end, such as the LS port shown in fig. 1) of the spring chamber at the right of the load sensitive valve 220 through the first oil port of the first directional valve 120. The load sensitive valve 220 needs to adjust the output flow of the variable pump 200 according to the pressure input by the LS port, and if oil continuously flows into the main oil tank 400 through the flow valve 130, the pressure input by the feedback of the LS port is inevitably smaller than the actual pressure, so that the load sensitive valve 220 makes an error in adjusting the variable pump 200, and the condition of output flow jitter of the variable pump 200 is caused. Here, the oil path of the flow valve 130 flowing into the main oil tank 400 is directly stopped by using the stop valve 140, so that all the pressure fed back from the first oil port of the first direction valve 120 can be completely pressurized to the LS port of the load sensitive valve 220, and the load sensitive valve 220 can obtain a correct pressure value, thereby stably controlling the output flow of the variable displacement pump 200.
Therefore, before closing the shutoff valve element 140, it is necessary to detect the states of the variable displacement pump 200 and the main arm telescopic cylinder 300, and when the variable displacement pump 200 is in an activated state and the main arm telescopic cylinder 300 is in a piston rod static state, the shutoff valve element 140 is closed to ensure that the most correct pressure can be obtained at the LS port of the load sensitive valve 220.
It should be noted that the flow valve 130 is used to timely release the pressure in the pipeline when the engine is shut down, so as to prevent the pressure in the pipeline from being in a closed state all the time. In addition, the stop valve element 140 is mainly used to close at the initial stage of starting the variable displacement pump 200 and operating the main arm, and is always in an open state in the subsequent normal operation, so as to ensure the normal operation of the whole pipeline.
The control method provided by the embodiment of the invention at least has the following technical effects: by closing the stop valve element 140 when the variable pump 200 is started and the piston rod of the main arm telescopic cylinder 300 is not pushed, it can be ensured that accurate feedback oil pressure can be obtained at the starting stage of the variable pump 200, so that the working state of the variable pump 200 can be accurately adjusted, and long-time jitter of the output flow of the variable pump 200 is avoided.
In some embodiments of the present invention, the control method further includes: if the variable displacement pump 200 is in the operating state or the stopped state, the cut-off valve element 140 is opened. When the variable displacement pump 200 is in an operating state or a stopped state, that is, when the piston rod of the main arm telescopic cylinder 300 is already moving or enters a stop from moving, it is necessary to keep the cut-off valve element 140 open. It should be noted here that, in the starting state of the variable displacement pump 200, a specific time period is provided until the piston rod of the main arm telescopic cylinder 300 moves after the variable displacement pump 200 is started.
The master arm cylinder control system according to the third embodiment of the present invention includes the master oil tank 400, the variable displacement pump 200, and the variable displacement pump flow control system as described above connected to the variable displacement pump 200.
The main arm oil cylinder control system provided by the embodiment of the invention at least has the following technical effects: by adding the variable pump flow control system, the shaking phenomenon of the main arm support when the main arm support is extended out and retracted and started can be effectively prevented, so that a series of problems caused by shaking of the arm support are avoided.
In some embodiments of the present invention, variable displacement pump 200 comprises: a pump body 210, a load sensitive valve 220, and a pressure shut-off valve 230. An oil inlet of the pump main body 210 is connected with the main oil tank 400, and an oil outlet of the pump main body is connected with an oil inlet of the proportional valve 110; the left position of the load sensitive valve 220 is connected with an oil outlet of the pump main body 210, the right position of the load sensitive valve is connected with an oil outlet of the proportional valve 110, and a working oil port is connected with a rodless cavity of a variable oil cylinder 211 of the pump main body 210; and a pressure cutoff valve 230 connected between an oil outlet of the pump main body 210 and a rodless chamber of the variable cylinder 211.
The load sensing valve 220 and the pressure cutoff valve 230 can adjust the flow output state of the pump main body 210 by adjusting the operation state of the piston rod of the variable cylinder 211, and the adjustment of the operation of the piston rod is performed by inputting oil into the rodless chamber. The load sensitive valve 220 is mainly used in the normal operation process, the spring pretightening force setting value of the right position of the load sensitive valve is usually smaller, for example, the spring pretightening force setting value can be set to be 20bar, when the left position of the load sensitive valve 220 is pressurized to exceed the sum of the pretightening force and the LS opening pressure, the valve core can be pushed to move to the right, and therefore the purpose of controlling the opening of the valve according to the pressure can be achieved. The spring preload setting value of the pressure stop valve 230 is much larger than the preload of the spring in the load sensitive valve 220, for example, 220bar may be set, when the pressurization at the left position of the pressure stop valve 230 is larger than 220bar, the pressure stop valve 230 may push the valve core to move right, so that the piston rod of the variable cylinder 211 pushes the swash plate of the variable pump 200 to rotate until the flow output of the pump main body 210 of the variable pump 200 is nearly zero, thereby achieving a high-pressure standby state.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
Although the embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited to the embodiments, and those skilled in the art will understand that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims (10)

1. A variable displacement pump flow control system, comprising:
the oil inlet of the proportional valve (110) is connected with the oil outlet of the variable pump (200), and the oil outlet is connected with the oil pressure feedback end of the variable pump (200);
the first reversing valve (120) is provided with a first oil port, a second oil port, a third oil port and a fourth oil port, the first oil port of the first reversing valve (120) is connected with the oil outlet of the proportional valve (110), the second oil port and the third oil port are used for adjusting the operation state of the main arm telescopic oil cylinder (300), and the fourth oil port is used for connecting a main oil tank (400);
the flow valve (130) is provided with a first oil port and a second oil port, and the first oil port of the flow valve (130) is connected with the oil outlet of the proportional valve (110);
and the stop valve piece (140) is connected between the second oil port of the flow valve (130) and the fourth oil port of the first reversing valve (120).
2. The variable pump flow control system of claim 1, wherein the variable pump (200) comprises:
an oil inlet of the pump main body (210) is connected with the main oil tank (400), and an oil outlet of the pump main body is connected with an oil inlet of the proportional valve (110);
the left position of the load sensitive valve (220) is connected with an oil outlet of the pump main body (210), the right position of the load sensitive valve is connected with an oil outlet of the proportional valve (110), and a working oil port is connected with a rodless cavity of a variable oil cylinder (211) of the pump main body (210);
and the pressure stop valve (230) is connected between an oil outlet of the pump main body (210) and a rodless cavity of the variable oil cylinder (211).
3. The variable pump flow control system of claim 1, further comprising a check valve (150) connected between an oil outlet of the proportional valve (110) and the first port of the flow valve (130).
4. The variable pump flow control system of claim 1, further comprising a relief valve (160) connected between an outlet of the variable pump (200) and the main tank (400).
5. The variable displacement pump flow control system of claim 1, further comprising a balancing valve (170) connected between the second port and the third port of the first directional control valve (120) and the main arm telescopic cylinder (300).
6. The variable displacement pump flow control system of claim 1, wherein the shutoff valve member (140) is a second reversing valve.
7. A control method applied to the variable displacement pump flow control system according to any one of claims 1 to 6, characterized by comprising the steps of:
confirming the running state of the variable pump (200), wherein the running state comprises a starting state, a working state and a stopping state;
confirming the operation state of a main arm telescopic oil cylinder (300), wherein the operation state comprises a piston rod pushing state and a piston rod static state;
and if the variable pump (200) is in the starting state and the main arm telescopic oil cylinder (300) is in the piston rod static state, closing a stop valve (140).
8. The control method according to claim 7, characterized by further comprising the steps of:
and if the variable pump (200) is in the working state or the stop state, opening the stop valve element (140).
9. A master arm cylinder control system comprising a master tank (400), a variable displacement pump (200) and a variable displacement pump flow control system according to any one of claims 1 to 6 connected to the variable displacement pump (200).
10. The master arm cylinder control system of claim 9, wherein the variable displacement pump (200) comprises:
an oil inlet of the pump main body (210) is connected with the main oil tank (400), and an oil outlet of the pump main body is connected with an oil inlet of the proportional valve (110);
the left position of the load sensitive valve (220) is connected with an oil outlet of the pump main body (210), the right position of the load sensitive valve is connected with an oil outlet of the proportional valve (110), and a working oil port is connected with a rodless cavity of a variable oil cylinder (211) of the pump main body (210);
and the pressure stop valve (230) is connected between an oil outlet of the pump main body (210) and a rodless cavity of the variable oil cylinder (211).
CN202111347172.2A 2021-11-15 2021-11-15 Variable pump flow control system, variable pump flow control method and main arm oil cylinder control system Pending CN114033762A (en)

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CN202111347172.2A CN114033762A (en) 2021-11-15 2021-11-15 Variable pump flow control system, variable pump flow control method and main arm oil cylinder control system

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Application Number Priority Date Filing Date Title
CN202111347172.2A CN114033762A (en) 2021-11-15 2021-11-15 Variable pump flow control system, variable pump flow control method and main arm oil cylinder control system

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CN114033762A true CN114033762A (en) 2022-02-11

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