CN114687979A - Plunger pump flow and power control system - Google Patents
Plunger pump flow and power control system Download PDFInfo
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- CN114687979A CN114687979A CN202210278862.5A CN202210278862A CN114687979A CN 114687979 A CN114687979 A CN 114687979A CN 202210278862 A CN202210278862 A CN 202210278862A CN 114687979 A CN114687979 A CN 114687979A
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- 238000006073 displacement reaction Methods 0.000 claims description 102
- 230000004044 response Effects 0.000 abstract description 4
- 239000003921 oil Substances 0.000 description 34
- 238000010586 diagram Methods 0.000 description 9
- 238000013016 damping Methods 0.000 description 4
- 230000009471 action Effects 0.000 description 3
- 230000008859 change Effects 0.000 description 3
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- 238000012986 modification Methods 0.000 description 3
- 238000005266 casting Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 230000000750 progressive effect Effects 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000010720 hydraulic oil Substances 0.000 description 1
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
- F04B1/12—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis
- F04B1/26—Control
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Abstract
The invention relates to a flow and power control system of a plunger pump, which comprises a valve body, a flow pilot control unit and a power control unit, wherein the valve body is provided with a first valve cavity, a second valve cavity and a third valve cavity; the flow control valve and the power control valve respectively adopt double valve core structures with different valve port structure forms, and response characteristics of flow control and power control can be designed according to actual working conditions.
Description
Technical Field
The invention relates to the technical field of hydraulic controllers, in particular to a plunger pump flow and power control system.
Background
On an excavator, the speed of each actuating element can change along with the change of the stroke of an operating handle, a hydraulic system can control the displacement of the actuating element according to the change, and the positive flow and the negative flow are different from each other in the changed signal acquisition position.
A positive flow control system: the pilot pressure of the operating handle not only controls the reversing valve, but also serves to regulate the displacement of the pump. When the actuating element does not work, the oil pump has no pilot pressure, the tilting tray has a small swing angle, and the oil pump only outputs a small amount of standby flow. When the pilot handle is operated, pressure proportional to the deflection of the handle is built in the hydraulic pilot circuit to control the displacement of the valve core of the reversing valve and the displacement of the pump. The flow rate of the oil pump and thus the operating speed of the actuator are proportional to the pilot pressure. The signal of the positive flow control system is collected from the secondary pilot pressure.
A negative flow control system: the flow of the hydraulic pump is divided into two parts by a proportional valve, one part is removed from an oil cylinder and used for pushing a load, and the flow is called as effective flow; the other part of the flow passes through the damping hole oil return tank through a middle oil drainage channel of the proportional valve and is called as waste flow, negative feedback pressure can be generated at the front end of the damping hole when the flow passes through the damping hole, the larger the flow passing through the damping hole is, the larger the negative feedback pressure is, and at the moment, the pump is at the minimum swing angle. When the pilot handle is pushed, most of the flow is effective flow, the waste flow is small, the negative feedback pressure is reduced, and the swing angle of the pump is increased at the moment. The signal of the negative flow control system is collected from the negative feedback pressure.
The total (constant) power control system is a control mode for limiting the power of the system in order to prevent the power of the plunger pump from exceeding the output power of the engine. When the power of the plunger pump reaches the set power value, the displacement adjusting mechanism limits the power of the system below the set power value by reducing the displacement. If the constant power set point is adjustable in operation, it is called variable power control.
In the prior art, the working principle and the motion relation of positive and negative flow control schemes are different greatly, and respective parts of the positive and negative flow control schemes cannot be used universally; the positive and negative flow control valve castings cannot be used universally, two casting molds need to be opened, and the cost is increased; the connection mode of internal parts of the negative flow control valve is complex, the motion feedback relationship is complex, and the variable mechanism fed back by the market has a clamping stagnation phenomenon; in the negative flow control scheme, the negative flow control valve and the power valve share a valve port form, and the response characteristics of the negative flow control valve and the power valve cannot be adjusted respectively; when the negative flow and power valves are simultaneously operated, the system outputs according to the minimum flow, and certain interference exists between the two valves.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a plunger pump flow and power control system, which realizes mechanical feedback connection through a feedback rod to form closed-loop control, realizes the switching of positive flow control and negative flow control through different valve core structures and different relative positions of a flow control unit, and has the advantages of multiple parts universality, low product cost and reliable structure.
The flow and power control system of the plunger pump comprises a valve body, a flow pilot control unit and a power control unit, wherein the valve body is provided with a first valve cavity, a second valve cavity and a third valve cavity, the power control unit is arranged in the third valve cavity, a feedback rod is arranged on the valve body through a fulcrum pin, one end of the feedback rod is connected to a variable piston, the power control unit comprises a power control valve sleeve and a power control valve core,
the system has a positive flow and power control mode of operation and a negative flow and power control mode of operation,
positive flow and power control mode of operation: a positive flow control unit and the flow pilot control unit are arranged in the first valve cavity, the positive flow control unit comprises a positive displacement control valve sleeve and a positive flow control valve core, the power control valve sleeve and the positive displacement control valve sleeve are respectively hinged to the feedback rod, hinged points are respectively positioned on two sides of the fulcrum pin, pressure controls the movement of the variable piston through the flow pilot control unit and the positive flow control unit, the movement direction of the power control valve sleeve is opposite to that of the variable piston, and the movement direction of the positive displacement control valve sleeve is the same as that of the variable piston;
negative flow and power control mode of operation: the second valve cavity is internally provided with a negative flow control unit and a flow pilot control unit, the negative flow control unit comprises a negative displacement control valve sleeve and a negative flow control valve core, the power control valve sleeve and the negative displacement control valve sleeve are respectively hinged to the feedback rod, the hinged point is positioned on the same side of the fulcrum pin, pressure controls the movement of the variable piston through the flow pilot control unit and the negative flow control unit, the movement direction of the power control valve sleeve is opposite to that of the variable piston, and the movement direction of the negative displacement control valve sleeve is opposite to that of the variable piston.
Optionally, the feedback rod is sequentially provided with a first pin hole, a fulcrum pin hole and a second pin hole along the length direction, the second pin hole is closer to the variable piston than the first pin hole, the fulcrum pin penetrates through the fulcrum pin hole, and in the positive flow and power control working mode, the power control valve sleeve is hinged and installed in the first pin hole through a connecting pin, and the positive displacement control valve sleeve is hinged and installed in the second pin hole through a connecting pin; under the working mode of negative flow and power control, the power control valve sleeve and the negative displacement control valve sleeve are jointly hinged and installed in the first pin hole through a connecting pin.
Optionally, a first cover plate and a second cover plate are respectively disposed at two ends of the valve body, the flow pilot control unit is installed between the first cover plate and the first valve cavity or the second valve cavity, a positive flow control spring assembly is disposed between the positive flow control valve core and the second cover plate, and a negative flow control spring assembly is disposed between the negative flow control valve core and the second cover plate.
Optionally, the positive flow control spring assembly and the negative flow control spring assembly are the same assembly.
Optionally, the positive flow control spring assembly includes a displacement spring seat, a spring adjustment seat, and a displacement spring abutting between the displacement spring seat and the spring adjustment seat, and the spring adjustment seat is mounted on the second cover plate through an adjusting screw.
Optionally, a power control spring assembly is disposed between the power control valve spool and the second cover plate.
Optionally, the power control spring assembly includes a power spring seat, a large spring, a small spring, a large spring seat and a small spring seat, the large spring seat is mounted on the second cover plate, the small spring seat is fixedly mounted on the large spring seat, the large spring is sleeved outside the small spring in a non-contact manner, two ends of the large spring are respectively abutted between the power spring seat and the large spring seat, and two ends of the small spring are respectively abutted between the power spring seat and the small spring seat.
Optionally, a power pilot control unit is disposed between the first cover plate and the third valve cavity, and the pressure controls the movement of the variable piston through the power pilot control unit and the power control unit.
Optionally, the flow pilot control unit includes a displacement pilot control valve sleeve and a displacement pilot control valve core, the power pilot control unit includes a power pilot control valve sleeve and a power pilot control valve core, the first cover plate is provided with a first pilot oil path and a second pilot oil path, the first pilot oil path penetrates through the displacement pilot control valve core, and the second pilot oil path penetrates through the power pilot control valve core.
Optionally, the positive displacement control valve housing and the negative displacement control valve housing are the same component.
Compared with the prior art, the technical scheme of the invention has the following beneficial effects: 1. the positive and negative flow control structure adopts the form of relative movement of a valve core and a valve sleeve, the valve sleeve and a variable piston form mechanical feedback connection through a feedback rod, closed-loop control is carried out on a control valve port through the logical movement relation of the valve core, the variable piston and the valve sleeve, the movement logics of the positive and negative flow control schemes are similar, and the movement relation is simple and reliable; 2. when the positive and negative flow control structures are switched, the displacement control valve only needs to be adjusted relative to the rotary fulcrum of the feedback rod, and the displacement control valve is respectively matched with the corresponding positive flow control valve core and the corresponding negative flow control valve core. The displacement control valve pocket and the variable piston in the positive flow control system move in the same direction to the large displacement, and the displacement control valve pocket and the variable piston in the negative flow control system move in the opposite direction to the large displacement; 3. the general degree of parts in the positive and negative flow control systems is high, and the valve body only needs to be provided with a pair of progressive dies, so that the product cost is reduced while the material types of the parts are reduced; 4. the flow control valve and the power control valve respectively adopt double-valve-core structures with different valve port structural forms, so that the response characteristics of displacement control and power control can be designed according to actual working conditions; 5. the load pressure of the front pump and the load pressure of the rear pump act on the power valves of the pumps at the same time, and the total power control of the serial pumps can be realized.
Drawings
FIG. 1 is a first schematic diagram of a positive flow and power control mode of operation according to the present invention;
FIG. 2 is a second schematic structural diagram of a positive flow and power control mode of operation according to the present invention;
FIG. 3 is a first schematic diagram illustrating a negative flow and power control mode of operation according to the present invention;
FIG. 4 is a second schematic structural diagram of the negative flow and power control mode of operation of the present invention;
FIG. 5 is a schematic diagram of a power control unit according to the present invention;
FIG. 6 is a schematic diagram of the positive flow and power control modes of operation of the present invention;
FIG. 7 is a schematic diagram of the negative flow and power control mode of operation of the present invention;
FIG. 8 is a motion logic diagram for positive flow and power control according to the present invention;
FIG. 9 is a logic diagram of the motion of the negative flow and power control of the present invention.
In the drawings: 1-power pilot control valve core, 2-power pilot control valve sleeve, 3-power control valve sleeve, 4-power control valve core, 5-displacement control valve sleeve, 6-negative flow control valve core, 7-second cover plate, 8-fulcrum pin, 11-displacement pilot control valve sleeve, 13-power spring seat, 14-displacement spring seat, 16-large spring, 17-small spring, 18-spring adjusting seat, 19-displacement spring, 20-large spring seat, 21-locking nut, 22-positive flow control valve core, 23-first cover plate, 25-adjusting screw, 28-displacement pilot control valve core, 31-electric proportional pressure reducing valve, 38-small spring seat, 39-valve body, 42-feedback rod and 45-variable piston.
Detailed Description
Exemplary embodiments of the invention are described below with reference to the accompanying drawings, in which various details of embodiments of the invention are included to assist understanding, and which are to be considered as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. Also, descriptions of well-known functions and constructions are omitted in the following description for clarity and conciseness.
The flow and power control system of the plunger pump comprises a valve body 39, a flow pilot control unit and a power control unit, wherein the valve body 39 is provided with a first valve cavity, a second valve cavity and a third valve cavity, the power control unit is arranged in the third valve cavity, a feedback rod 42 is arranged on the valve body 39 through a fulcrum pin 8, one end of the feedback rod 42 is connected to a variable piston 45, and the power control unit comprises a power control valve sleeve 3 and a power control valve core 4.
The system has a positive flow and power control working mode and a negative flow and power control working mode, and comprises the following specific steps:
positive flow and power control mode of operation: a positive flow control unit and a flow pilot control unit are arranged in the first valve cavity, the positive flow control unit comprises a positive displacement control valve sleeve 5 and a positive flow control valve core 22, the power control valve sleeve 3 and the positive displacement control valve sleeve 5 are respectively hinged to the feedback rod 42, hinged points are respectively positioned on two sides of the fulcrum pin 8, pressure controls the variable piston 45 to move through the flow pilot control unit and the positive flow control unit, the moving direction of the power control valve sleeve 3 is opposite to the moving direction of the variable piston 45, and the moving direction of the positive displacement control valve sleeve 5 is the same as the moving direction of the variable piston 45;
negative flow and power control mode of operation: the second valve cavity is internally provided with a negative flow control unit and a flow pilot control unit, the negative flow control unit comprises a negative displacement control valve sleeve 5 and a negative flow control valve core 6, the power control valve sleeve 3 and the negative displacement control valve sleeve 5 are respectively hinged to the feedback rod 42, the hinged points are positioned on the same side of the fulcrum pin 8, the pressure controls the movement of the variable piston 45 through the flow pilot control unit and the negative flow control unit, the movement direction of the power control valve sleeve 3 is opposite to that of the variable piston 45, and the movement direction of the negative displacement control valve sleeve 5 is opposite to that of the variable piston 45.
As for the above embodiment, more specifically, the feedback rod 42 is sequentially provided with a first pin hole, a fulcrum pin 8 hole and a second pin hole along the length direction, the second pin hole is closer to the variable piston 45 than the first pin hole, the fulcrum pin 8 passes through the fulcrum pin 8 hole, in the positive flow and power control operation mode, the power control valve sleeve 3 is hinged and installed in the first pin hole through a connecting pin, and the positive displacement control valve sleeve 5 is hinged and installed in the second pin hole through a connecting pin; under the working mode of negative flow and power control, the power control valve sleeve 3 and the negative displacement control valve sleeve 5 are jointly hinged and installed in the first pin hole through a connecting pin; a first cover plate 23 and a second cover plate 7 are respectively arranged at two ends of the valve body 39, the flow pilot control unit is installed between the first cover plate 23 and the first valve cavity or the second valve cavity, a positive flow control spring assembly is arranged between the positive flow control valve core 22 and the second cover plate 7, and a negative flow control spring assembly is arranged between the negative flow control valve core 6 and the second cover plate 7; the positive flow control spring assembly and the negative flow control spring assembly are the same assembly; the positive flow control spring assembly comprises a displacement spring seat 14, a spring adjusting seat and a displacement spring 19 abutted between the displacement spring seat 14 and the spring adjusting seat, and the spring adjusting seat is mounted on the second cover plate 7 through an adjusting screw 25; a power control spring assembly is arranged between the power control valve core 4 and the second cover plate 7; the power control spring assembly comprises a power spring seat 13, a large spring 16, a small spring 17, a large spring seat 20 and a small spring seat 38, the large spring seat 20 is installed on the second cover plate 7 through a lock nut 21, the small spring seat 38 is fixedly installed on the large spring seat 20, the large spring 16 is sleeved outside the small spring 17 in a non-contact mode, two ends of the large spring 16 abut against between the power spring seat 13 and the large spring seat 20 respectively, and two ends of the small spring 17 abut against between the power spring seat 13 and the small spring seat 38 respectively; a power pilot control unit is arranged between the first cover plate 23 and the third valve cavity, and the pressure controls the variable piston 45 to move through the power pilot control unit and the power control unit; the flow pilot control unit comprises a displacement pilot control valve sleeve 11 and a displacement pilot control valve core 28, the power pilot control unit comprises a power pilot control valve sleeve 2 and a power pilot control valve core 1, a first pilot oil path and a second pilot oil path are formed in the first cover plate 23, the first pilot oil path penetrates through the displacement pilot control valve core 28, and the second pilot oil path penetrates through the power pilot control valve core 1; the positive displacement control valve sleeve 5 and the negative displacement control valve sleeve 5 are the same component; the first cover plate 23 and the second cover plate 7 are mounted on the valve body 39 by screw connection, respectively.
As can be seen from the attached drawings, most of the components are common in the positive flow power control operation mode and the negative flow power control operation mode of the present embodiment, the common components include the valve body 39, the displacement pilot control spool 28, the displacement pilot control valve sleeve 11, the displacement control valve sleeve 5, the feedback rod 42, the displacement spring seat 14, the spring adjustment seat 18, the second cover plate 7, the adjustment screw 25, the fulcrum pin 8, and the power control unit, while the non-common components include the positive flow control spool 22, the displacement spring 19, the connecting pin for the feedback rod 42 of the positive/negative displacement control valve sleeve 5, and the first cover plate 23.
Working principle of positive flow control: as shown in fig. 1, 2, 5, and 6, the electric proportional pressure reducing valve 31 inputs current, the output secondary pressure acts on the displacement pilot control valve core 28, the displacement pilot control valve core 28 pushes the positive flow control valve core 22 to move under the action of pressure oil, the spring force of the displacement spring 19 is overcome, and finally, a force balance state is reached, the positive flow control valve core 22 stops moving, at this time, the passage from the load port P to the control chamber C of the variable piston 45 is gradually closed, the passage from the control chamber C of the variable piston 45 to the oil drainage port T is opened, the variable piston 45 drives the swash plate to move in a large swing angle direction under the action of pressure difference, the feedback rod 42 is driven to rotate counterclockwise around the fulcrum pin 8 while the variable piston 45 moves, the feedback rod 42 drives the displacement control valve sleeve 5 to move rightward (the left and right directions in this position are the same as the left and right directions in fig. 1), the passage from the piston control chamber C to the oil drainage port T is gradually closed, the swing angle of the pump is fixed at a certain angle and stops.
The working principle of negative flow control is as follows: as shown in fig. 3, 4, 5, and 7, when the system main control valve is in the neutral position, the negative flow feedback pressure Pi is maximum and acts on the left end of the displacement pilot control spool 28 through the internal passage (the left-right direction in this case is the same as the left-right direction in fig. 3), the displacement pilot control spool 28 pushes the negative flow control spool 6 to move rightward against the displacement spring 19 (the left-right direction in this case is the same as the left-right direction in fig. 3), and finally, a force equilibrium state is reached, and the negative flow control spool 6 is controlled to stop moving. In the moving process of the negative flow control valve core 6, a passage from the oil port P to the oil port a in fig. 7 is opened, then enters the control cavity C of the variable piston 45 through the oil port B of the power control valve, and simultaneously closes the passage from the control cavity C of the variable piston 45 to the oil drainage oil port T, at this time, the variable piston 45 moves leftwards (the left and right directions in the position are the same as the left and right directions in fig. 3), and the swing angle of the pump is reduced. When the variable piston 45 moves leftwards, the variable piston 45 drives the feedback rod 42 to rotate clockwise around the fulcrum pin 8, meanwhile, the feedback rod 42 drives the displacement control valve sleeve 5 to move rightwards, the passage from the oil port P to the oil port A is gradually closed, and the swing angle of the pump is fixed to the minimum value and then stops. When the handle of the main control valve of the system starts to act, the negative flow feedback pressure Pi is reduced, the valve core balance position is broken, the negative flow control valve core 6 moves leftwards under the action of the displacement spring 19, a passage from the control cavity C to the oil port T of the variable piston 45 is opened at the moment (hydraulic oil in the control cavity C passes through the oil port B of the power control valve and then returns to the oil tank through the oil port A), the variable piston 45 moves rightwards, and the swing angle of the pump is gradually increased. When the variable piston 45 moves rightwards, the variable piston 45 drives the feedback rod 42 to rotate anticlockwise around the fulcrum pin 8, meanwhile, the feedback rod 42 drives the displacement control valve sleeve 5 to move leftwards, the channel of the control cavity C and the oil port T of the variable piston 45 is gradually closed, and the swing angle of the pump is fixed to a certain angle and stops. When the handle of the main control valve of the system is fully opened, the negative flow feedback pressure Pi is reduced to 0, the swing angle of the pump is the maximum at the moment, and the pump is at the maximum displacement.
Working principle of power control: as shown in fig. 5, 6, and 7, when the system main control valve is at a certain position (not fully closed), and the pump is at a certain displacement (not minimum displacement), load pressures P1 and P2 respectively act on two step annular surfaces formed between the power control valve core 4 and the power control valve sleeve 3, the load simultaneously acts on the small cavity D of the variable piston 45, when the two hydraulic pressures are greater than the pre-tightening forces of the large spring 16 and the small spring 17, the power control valve core 4 moves to the right (the left and right directions are the same as the left and right directions in fig. 5), a passage from the oil port P to the oil port B of the power control valve is opened, high-pressure oil enters the control cavity C of the variable piston 45, and the variable piston 45 moves to the direction that the swing angle of the pump is reduced under the effect of the difference in the area between the large cavity and the small cavity of the variable piston 45. When the variable piston 45 moves, the variable piston 45 drives the feedback rod 42 to rotate clockwise around the fulcrum pin 8, and simultaneously the feedback rod 42 drives the power control valve sleeve 3 to move rightwards (the left-right direction of the feedback rod is the same as that in fig. 5), so that the passage from the oil port P to the oil port B is gradually closed, and the swing angle of the pump is fixed to a certain angle and stops.
As shown in fig. 1, 2, 3, 4, 8, and 9, the positive flow control and the negative flow control are switched by adjusting the vertical position of the displacement control valve relative to the fulcrum pin 8 and the structural design of the flow control valve core, wherein in the positive flow control operation mode, the displacement control valve sleeve 5 is located below the fulcrum pin 8, the displacement control valve sleeve 5 and the variable piston 45 form mechanical positive feedback, and the moving direction of the displacement control valve sleeve 5 is the same as the moving direction of the variable piston 45 to a large displacement; in the negative flow control working mode, the displacement control valve sleeve 5 is positioned above the fulcrum pin 8 (and is parallel to the power control valve), the displacement control valve sleeve 5 and the variable piston 45 form mechanical negative feedback, and the moving direction of the displacement control valve sleeve 5 is opposite to the moving direction of the variable piston 45 to large displacement; in the positive flow and power control working mode and the negative flow meter power control working mode, the power control valve sleeve 3 and the variable piston 45 form mechanical negative feedback, and the moving direction of the power control valve sleeve 3 is opposite to the moving direction of the variable piston 45 to the large displacement.
Compared with the prior art, the plunger pump flow and power control system has the following advantages: 1. the positive and negative flow control structure adopts the form of relative movement of a valve core and a valve sleeve, the valve sleeve and a variable piston form mechanical feedback connection through a feedback rod, closed-loop control is carried out on a control valve port through the logical movement relation of the valve core, the variable piston and the valve sleeve, the movement logics of the positive and negative flow control schemes are similar, and the movement relation is simple and reliable; 2. when the positive and negative flow control structures are switched, the displacement control valve only needs to be adjusted relative to the rotary fulcrum of the feedback rod, and the displacement control valve is respectively matched with the corresponding positive flow control valve core and the corresponding negative flow control valve core. The displacement control valve pocket and the variable piston in the positive flow control system move in the same direction to the large displacement, and the displacement control valve pocket and the variable piston in the negative flow control system move in the opposite direction to the large displacement; 3. the general degree of parts in the positive and negative flow control systems is high, and the valve body only needs to be provided with a pair of progressive dies, so that the product cost is reduced while the material types of the parts are reduced; 4. the flow control valve and the power control valve respectively adopt double-valve-core structures with different valve port structural forms, so that the response characteristics of displacement control and power control can be designed according to actual working conditions; 5. the load pressure of the front pump and the load pressure of the rear pump act on the power valve of each pump at the same time, and the control of the total power of the serial pumps can be realized.
The above detailed description should not be construed as limiting the scope of the invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions can occur, depending on design requirements and other factors. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. The plunger pump flow and power control system is characterized by comprising a valve body, a flow pilot control unit and a power control unit, wherein the valve body is provided with a first valve cavity, a second valve cavity and a third valve cavity, the power control unit is arranged in the third valve cavity, a feedback rod is arranged on the valve body through a fulcrum pin, one end of the feedback rod is connected to a variable piston, the power control unit comprises a power control valve sleeve and a power control valve core,
the system has a positive flow and power control mode of operation and a negative flow and power control mode of operation,
positive flow and power control mode of operation: a positive flow control unit and a flow pilot control unit are arranged in the first valve cavity, the positive flow control unit comprises a positive displacement control valve sleeve and a positive flow control valve core, the power control valve sleeve and the positive displacement control valve sleeve are respectively hinged to the feedback rod, hinged points are respectively located on two sides of the fulcrum pin, pressure controls the movement of the variable piston through the flow pilot control unit and the positive flow control unit, the movement direction of the power control valve sleeve is opposite to that of the variable piston, and the movement direction of the positive displacement control valve sleeve is the same as that of the variable piston;
negative flow and power control mode of operation: the second valve cavity is internally provided with a negative flow control unit and a flow pilot control unit, the negative flow control unit comprises a negative displacement control valve sleeve and a negative flow control valve core, the power control valve sleeve and the negative displacement control valve sleeve are respectively hinged to the feedback rod, the hinged point is positioned on the same side of the fulcrum pin, pressure controls the movement of the variable piston through the flow pilot control unit and the negative flow control unit, the movement direction of the power control valve sleeve is opposite to that of the variable piston, and the movement direction of the negative displacement control valve sleeve is opposite to that of the variable piston.
2. The system of claim 1, wherein the feedback rod is provided with a first pin hole, a fulcrum pin hole and a second pin hole arranged in sequence along the length direction, the second pin hole is closer to the variable piston than the first pin hole, the fulcrum pin passes through the fulcrum pin hole,
under the positive flow and power control working mode, the power control valve sleeve is hinged and installed in the first pin hole through a connecting pin, and the positive displacement control valve sleeve is hinged and installed in the second pin hole through a connecting pin;
under the negative flow and power control working mode, the power control valve sleeve and the negative displacement control valve sleeve are hinged and installed in the first pin hole together through a connecting pin.
3. The system as claimed in claim 1, wherein a first cover plate and a second cover plate are respectively disposed at two ends of the valve body, the flow pilot control unit is installed between the first cover plate and the first valve chamber or the second valve chamber, a positive flow control spring assembly is disposed between the positive flow control valve core and the second cover plate, and a negative flow control spring assembly is disposed between the negative flow control valve core and the second cover plate.
4. The system of claim 3, wherein the positive flow control spring assembly and the negative flow control spring assembly are the same assembly.
5. The system of claim 4, wherein the positive flow control spring assembly comprises a displacement spring seat, a spring adjustment seat, and a displacement spring abutting between the displacement spring seat and the spring adjustment seat, the spring adjustment seat being mounted on the second cover plate by an adjustment screw.
6. The system of claim 3, wherein a power control spring assembly is disposed between the power control spool and the second cover plate.
7. The system as claimed in claim 6, wherein the power control spring assembly comprises a power spring seat, a large spring, a small spring, a large spring seat and a small spring seat, the large spring seat is mounted on the second cover plate, the small spring seat is fixedly mounted on the large spring seat, the large spring is sleeved outside the small spring in a non-contact manner, two ends of the large spring are respectively abutted between the power spring seat and the large spring seat, and two ends of the small spring are respectively abutted between the power spring seat and the small spring seat.
8. The system of claim 3, wherein a power pilot control unit is disposed between the first cover plate and the third valve chamber, pressure controlling the variable piston movement through the power pilot control unit and the power control unit.
9. The system as claimed in claim 8, wherein the flow pilot control unit includes a displacement pilot control valve housing and a displacement pilot control valve core, the power pilot control unit includes a power pilot control valve housing and a power pilot control valve core, a first pilot oil path and a second pilot oil path are opened on the first cover plate, the first pilot oil path is communicated to the displacement pilot control valve core, and the second pilot oil path is communicated to the power pilot control valve core.
10. The system as defined in any one of claims 1-9, wherein said positive displacement control valve housing and said negative displacement control valve housing are the same component.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210278862.5A CN114687979A (en) | 2022-03-21 | 2022-03-21 | Plunger pump flow and power control system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210278862.5A CN114687979A (en) | 2022-03-21 | 2022-03-21 | Plunger pump flow and power control system |
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01227881A (en) * | 1988-03-07 | 1989-09-12 | Kawasaki Heavy Ind Ltd | Controller of variable capacity hydraulic pump |
| JPH10274167A (en) * | 1997-03-31 | 1998-10-13 | Kawasaki Heavy Ind Ltd | Flow rate control device for volume variable type pump |
| CN102352834A (en) * | 2011-10-13 | 2012-02-15 | 杭州力龙液压有限公司 | Constant-power control valve |
| CN104061143A (en) * | 2013-07-17 | 2014-09-24 | 福州大学 | Negative flow and total power control system applied to axial piston pump |
| US20150345491A1 (en) * | 2013-11-20 | 2015-12-03 | Jiangsu Hengli Hydraulic Co., Ltd | Plunger pump power control device and control method thereof |
| CN204851560U (en) * | 2015-08-01 | 2015-12-09 | 烟台艾迪液压科技有限公司 | Positive flow control electric proportional pump |
| CN107781126A (en) * | 2017-11-22 | 2018-03-09 | 江苏恒立液压科技有限公司 | Hydraulic pump control valve |
| CN108591151A (en) * | 2018-02-05 | 2018-09-28 | 江苏恒立液压科技有限公司 | Hydraulic axial plunger pump power control and positive flow control mechanism |
| CN110307143A (en) * | 2019-06-21 | 2019-10-08 | 江苏恒立液压科技有限公司 | A kind of variable servo valve, power servo valve and variable pump |
-
2022
- 2022-03-21 CN CN202210278862.5A patent/CN114687979A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01227881A (en) * | 1988-03-07 | 1989-09-12 | Kawasaki Heavy Ind Ltd | Controller of variable capacity hydraulic pump |
| JPH10274167A (en) * | 1997-03-31 | 1998-10-13 | Kawasaki Heavy Ind Ltd | Flow rate control device for volume variable type pump |
| CN102352834A (en) * | 2011-10-13 | 2012-02-15 | 杭州力龙液压有限公司 | Constant-power control valve |
| CN104061143A (en) * | 2013-07-17 | 2014-09-24 | 福州大学 | Negative flow and total power control system applied to axial piston pump |
| US20150345491A1 (en) * | 2013-11-20 | 2015-12-03 | Jiangsu Hengli Hydraulic Co., Ltd | Plunger pump power control device and control method thereof |
| CN204851560U (en) * | 2015-08-01 | 2015-12-09 | 烟台艾迪液压科技有限公司 | Positive flow control electric proportional pump |
| CN107781126A (en) * | 2017-11-22 | 2018-03-09 | 江苏恒立液压科技有限公司 | Hydraulic pump control valve |
| CN108591151A (en) * | 2018-02-05 | 2018-09-28 | 江苏恒立液压科技有限公司 | Hydraulic axial plunger pump power control and positive flow control mechanism |
| CN110307143A (en) * | 2019-06-21 | 2019-10-08 | 江苏恒立液压科技有限公司 | A kind of variable servo valve, power servo valve and variable pump |
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