A plunger mechanical flow distribution and testing system based on constant pressure flow channel

Abstract

The application discloses a kind of plunger mechanical flow distribution and test system based on constant pressure flow channel, including double-flow channel constant pressure end plunger pump, plunger motor, high-speed switch valve, magnetic fluid accumulator, overflow valve, reversing valve and pressure reducing valve;Third oil port of double-flow channel constant pressure end plunger pump is connected with magnetic fluid accumulator, overflow valve by reversing valve, first oil port and second oil port of double-flow channel constant pressure end plunger pump are connected with pressure reducing valve by reversing valve, high-speed switch valve is connected with the first oil channel of double-flow channel constant pressure end plunger pump, and plunger motor is connected with the oil inlet and oil suction of pressure reducing valve respectively by high-speed switch valve of high-pressure end and low-pressure end.The application realizes more accurate control of flow by double-flow channel constant pressure end plunger pump and high-speed switch valve, reduces flow pulsation and improves the adaptability of digital flow distribution system to engineering variable working condition by magnetic fluid accumulator, and improves the versatility of test system by reversing valve, pressure reducing valve and the like.

Description

Technical Field

[0001] This invention relates to the field of hydraulic transmission, specifically to a piston mechanical flow distribution and testing system based on a constant pressure flow channel. Background Technology

[0002] In recent years, digital flow distribution technology, represented by high-speed switching valves, has developed rapidly in the hydraulic field. By connecting a set of high-speed switching valves to each plunger chamber, oil flow distribution is controlled, thereby achieving plunger pump displacement control or plunger motor speed control. For plunger mechanical displacement control strategies, there are currently two main categories: full-stroke control strategy (FSCS) and partial flow restriction strategy (PSCS). However, the variable control performance of the control strategy largely depends on the performance of the high-speed switching valves. Factors such as the frequency and flow capacity of the high-speed switching valves directly affect the displacement accuracy, with the frequency of the high-speed switching valves directly determining the valve core opening and closing delay. Variable operating conditions are the biggest factor causing changes in valve core opening and closing delays. For traditional plunger machinery, each plunger chamber alternates between discharge and suction strokes. Correspondingly, the plunger chamber experiences rapidly changing operating conditions between high and low pressure. The timing control strategy achieves flow distribution control by controlling the proportion of opening time of each switching valve within a cycle. The controller generates a digital code stream based on the displacement demand, controlling the energizing sequence and timing of the high-speed switching valves. Within a control cycle, the plunger cavity undergoes multiple oil suction and discharge processes, which directly causes a large variation in the valve core's opening and closing delay error, affecting the accuracy of constant flow distribution.

[0003] On the other hand, timing control strategies only control the displacement of the piston mechanism within a single cycle, while the output flow rate after regulation by high-speed switching valves exhibits significant pulsation. To achieve constant output flow rate at different speeds, an accumulator with the same rated operating pressure as the load pressure must be installed at the output end to reduce flow pulsation. However, in complex engineering conditions, the load is variable at any time, and existing accumulators cannot change their rated operating pressure in real time. Furthermore, the operating mechanisms of piston pumps and piston motors differ, necessitating the design of a novel testing system to simultaneously perform digital flow distribution testing on both piston pumps and piston motors. Summary of the Invention

[0004] The purpose of this invention is to address the problems mentioned in the background section by proposing a plunger mechanical flow distribution and testing system based on a constant-pressure flow channel. This system utilizes dual reciprocating guides to achieve alternating oil intake and discharge for each set of internal and external plungers, ensuring that the sealed oil chamber of the high-speed switching valve remains at high pressure. This solves the complex operating conditions of high-speed switching valves, which involve frequent switching between high and low pressure within the plunger chamber, a problem encountered in traditional plunger mechanical systems. By adjusting the gas chamber pressure of the magnetohydrodynamic accumulator to match the damping of the variable load, the system solves the problem of constant flow distribution in plunger mechanical systems under varying engineering conditions. Furthermore, by controlling directional valves and pressure reducing valves, the flow distribution mode can be changed, enabling digital flow distribution testing of dual-channel constant-pressure pumps and dual-channel constant-pressure motors, thus improving the versatility of the testing system.

[0005] The objective of this invention can be achieved through the following technical solution: a plunger mechanical flow distribution and testing system based on a constant pressure flow channel, comprising a plunger end flow output component consisting of a motor, a dual-flow channel constant pressure end plunger pump, a high-speed switching valve, a magnetohydrodynamic accumulator, a variable load, and a controller, and further comprising a flow distribution mode control component, wherein the flow distribution mode control component comprises a reversing valve, a relief valve, a shut-off valve, a sixth check valve, an oil tank, an auxiliary pump, and a pressure reducing valve;

[0006] The dual-channel constant pressure plunger pump is equipped with a pump shaft, and an annular cavity is formed between the pump shaft, the outer pump body, and the inner pump body. Several radially distributed plunger holes are provided in the outer pump body and the inner pump body respectively. The pump shaft is fixed to the double reciprocating guide rail by spline connection in the annular cavity. Several sets of outer discharge plungers and inner discharge plungers are evenly arranged on the outer and inner rings of the double reciprocating guide rail respectively. Each outer discharge plunger is installed in the plunger hole of the outer pump body, and each inner discharge plunger is installed in the plunger hole of the inner pump body. When the pump shaft drives the double reciprocating guide rail to rotate, each set of outer discharge plungers and inner discharge plungers performs reciprocating periodic motion along the double reciprocating guide rail in the corresponding plunger hole. When each set of outer discharge plungers is sucking oil, the corresponding inner discharge plunger is in the oil discharge stroke. The oil suction and discharge strokes of the two are exactly opposite.

[0007] The external pump body has a first oil passage on one side of each plunger hole and a second oil passage on the other side. A first check valve is installed in the first oil passage, and a second check valve is installed in the second oil passage. The first oil passage, the second oil passage, and the corresponding plunger hole form a T-shaped channel. One end of the corresponding first check valve, the external plunger, and one end of the second check valve form a sealed plunger cavity. The other end of each first check valve is simultaneously connected to one end of the valve port of the high-speed switching valve, a fifth check valve, and a third oil passage. The other end of the valve port of the high-speed switching valve is connected to the other end of the second check valve through the fifth oil passage. Each second oil passage and the fifth oil passage are connected to the first distribution fluid through a ring. The inner pump body has a third oil passage and a fourth oil passage on one side of each plunger hole. A third check valve is installed in the third oil passage, and a fourth check valve is installed in the fourth oil passage. One end of the third check valve, one end of the fourth check valve, and the inner plunger form a sealed plunger cavity. The other end of the third check valve forms a sealed oil cavity with the high-speed switching valve, the fifth check valve, and the first check valve. A high-speed switching valve and a fifth check valve are installed in each of these oil cavities. Each fifth check valve is connected to the third oil port through an annular oil cavity in the third distribution fluid, and each fourth oil passage is connected to the second oil port through an annular oil cavity in the second distribution fluid.

[0008] The A port of the reversing valve is connected to the oil port of the magnetohydrodynamic accumulator, the oil inlet of the overflow valve, and the oil inlet of the shut-off valve, respectively. The oil port of the magnetohydrodynamic accumulator is equipped with a third pressure sensor. The oil port of the magnetohydrodynamic accumulator is connected to the oil inlet of the motor. The oil inlet of the motor is equipped with a second flow meter. The motor is connected to a variable load. The oil outlet of the overflow valve is connected to the hydraulic control port of the pressure reducing valve. The oil outlet of the overflow valve is equipped with a first pressure sensor. The oil outlet of the shut-off valve is connected to the oil inlet of the sixth check valve. The oil outlet of the sixth check valve is connected to the oil tank. The B port of the reversing valve is connected to the A port of the pressure reducing valve. The B port of the pressure reducing valve is connected to the oil outlet of the auxiliary pump. The B port of the pressure reducing valve is equipped with a second pressure sensor and a first flow meter. When the reversing valve is in the upper position: the P port of the reversing valve is connected to the first oil port and the second oil port, respectively. The T port of the reversing valve is connected to the third oil port.

[0009] The magnetohydrodynamic accumulator has a movable end cap at its port. A baffle is fixed inside the housing of the magnetohydrodynamic accumulator. The outer shell of a magnetohydrodynamic damper is fixedly installed at the center of one side of the baffle. The push rod of the magnetohydrodynamic damper is fixedly connected to one side of the baffle. The baffle can move inside the housing. Multiple springs are fixedly connected between the baffle and the baffle. The push rod of the magnetohydrodynamic damper is fixedly connected to the other side of the baffle. The outer shell of the magnetohydrodynamic damper is fixed to the bottom of the housing. The bottom of the housing has a connection port for connecting to the air pump.

[0010] In a preferred embodiment of the present invention, the first and second oil ports of the dual-channel constant pressure plunger pump are low-pressure suction ports, and the third oil port is a high-pressure discharge port. The second and fourth check valves are configured as suction check valves. Low-pressure oil enters the plunger cavity of the outer discharge plunger from the first oil port through the second check valve, and low-pressure oil enters the plunger cavity of the inner discharge plunger from the second oil port through the fourth check valve. One end of the valve port of the high-speed switching valve is connected to the suction cavity of the first oil port. The first, third, and fifth check valves are configured as discharge check valves. High-pressure oil in the plunger cavity of the outer discharge plunger flows into the third oil port through the first and fifth check valves, and high-pressure oil in the plunger cavity of the inner discharge plunger flows into the third oil port through the third and fifth check valves. The other end of the valve port of the high-speed switching valve is connected to the discharge cavity formed by the first, third, and fifth check valves.

[0011] In a preferred embodiment of the present invention, when the reversing valve is in the lower position, the test system performs a flow distribution test between the plunger motor and the high-speed switching valve. An angle encoder is installed on the plunger motor. At this time, the T port of the reversing valve is connected to the valve port of the high-pressure end of the high-speed switching valve. The other valve port of the high-speed switching valve is simultaneously connected to the plunger chamber of the plunger motor and the valve port of the low-pressure end of the high-speed switching valve. The other valve port of the high-speed switching valve is connected to the P port of the reversing valve.

[0012] In a preferred embodiment of the present invention, the push rod of the first magnetohydrodynamic damper / second magnetohydrodynamic damper is provided with a small through hole and an electromagnetic coil, and the rodless cavity and the rod cavity of the push rod are filled with magnetohydrodynamic fluid.

[0013] In a preferred embodiment of the present invention, the motor is connected to one end of the pump shaft of the dual-channel constant pressure piston pump, and the angle encoder is installed at the other end of the pump shaft. The output ends of the first pressure sensor, the second pressure sensor, the third pressure sensor, and the angle encoder are respectively connected to the signal input end of the controller. The control ends of the high-speed switching valve and the reversing valve are respectively connected to the signal output end of the controller.

[0014] In a preferred embodiment of the present invention, the high-speed switching valve is a two-position two-way electrically controlled bidirectional normally closed switching valve, the reversing valve is a two-position four-way electrically controlled reversing valve, the oil suction port of the auxiliary pump is connected to the oil outlet of the filter, and the oil inlet of the filter is connected to the oil tank.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] 1. In the dual-flow constant pressure end plunger pump of the present invention, each set of external and internal discharge plungers alternately sucks and discharges oil. By setting multiple one-way valves in the flow channel, a constant high pressure condition is achieved at the plunger end, ensuring that the high-speed switching valve can achieve high-speed opening and closing under stable pressure, reducing the opening delay error of the switching valve, stabilizing the closing delay error of the switching valve, not only reducing the difficulty of achieving mechanical flow distribution control of the plunger in the high-speed switching valve, but also improving the accuracy of constant flow distribution in the system.

[0017] 2. This invention employs a dual-stage damping design to control the gas chamber pressure of the magnetohydrodynamic accumulator to match the variable load. By changing the current of the electromagnetic coil, the damping force output by the main magnetohydrodynamic damper and the secondary magnetohydrodynamic damper can be adjusted. This damping force will adaptively change with the load, giving the distribution system good damping characteristics. This not only effectively reduces the flow pulsation of the hydraulic system under the time-sequential distribution strategy, thereby achieving constant flow distribution of the system, but also improves the adaptability of the digital distribution system to engineering conditions that change with the load.

[0018] 3. The present invention uses directional valves, pressure reducing valves and other components to form the control part of the test system. By combining directional valves, shut-off valves and pressure reducing valves, the pressure and flow direction of the oil circuit are changed, thereby testing the digital flow distribution of two modes: dual-channel constant pressure end plunger pump and plunger motor, and improving the versatility of the test system. Attached Figure Description

[0019] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0020] Figure 1 This is a schematic diagram of the plunger mechanical flow distribution and testing system based on a constant pressure flow channel in the pump mode of the present invention.

[0021] Figure 2 This is a schematic diagram of the plunger mechanical flow distribution and testing system based on a constant pressure flow channel in the motor mode of the present invention.

[0022] Figure 3 This is a schematic diagram of the dual-channel constant pressure end plunger pump of the present invention;

[0023] Figure 4 This is a cross-sectional view of the dual-flow-channel constant-pressure end plunger pump of the present invention;

[0024] Figure 5 Schematic diagram of a variable operating condition pressure magnetohydrodynamic accumulator and a magnetohydrodynamic damper;

[0025] Figure 6 This is a schematic diagram showing the output flow rate before and after the accumulator when the flow distribution system of the present invention is applied under variable speed conditions.

[0026] Reference numerals: 1. Motor; 2. Angle encoder; 3. Dual-channel constant pressure plunger pump; 311. First oil passage; 312. Second oil passage; 313. Third oil passage; 314. Fourth oil passage; 315. Fifth oil passage; 321. First check valve; 322. Second check valve; 323. Third check valve; 324. Fourth check valve; 325. Fifth check valve; 331. First oil port; 332. Second oil port; 333. Third oil port; 34. External discharge plunger; 35. Double reciprocating guide rail; 36. Internal discharge plunger; 37. Pump shaft; 381. First distribution fluid; 382. Second distribution fluid; 383. Third distribution fluid; 391. External pump body; 392. Internal pump body; 4. High-speed switching valve 5. Reversing valve; 6. Magnetohydrodynamic accumulator; 61. End cap; 62. Housing; 63. Baffle 1; 64. Spring; 65. Magnetohydrodynamic damper 1; 66. Baffle 2; 67. Magnetohydrodynamic damper 2; 68. Connection port; 69. Electromagnetic coil; 691. Magnetohydrodynamic fluid; 692. Housing; 693. Push rod; 7. Air pump; 8. Motor; 9. Variable load; 10. Overflow valve; 11. Shut-off valve; 12. Sixth check valve; 13. Oil tank; 14. Filter; 15. Auxiliary pump; 161. First flow meter; 162. Second flow meter; 171. First pressure sensor; 172. Second pressure sensor; 173. Third pressure sensor; 18. Pressure reducing valve; 19. Piston motor. Detailed Implementation

[0027] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Please see Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, a piston mechanical flow distribution and testing system based on a constant pressure flow channel mainly includes a constant pressure end flow output component and a flow distribution mode control component. The constant pressure end flow output component mainly consists of a motor 1, a dual-flow channel constant pressure end piston pump 3, a high-speed switching valve 4, a magnetohydrodynamic accumulator 6, a motor 8, a variable load 9, and a controller. The flow distribution mode output component mainly consists of a reversing valve 5, a relief valve 10, a shut-off valve 11, a sixth check valve 12, an oil tank 13, an auxiliary pump 15, and a pressure reducing valve 18.

[0029] The reversing valve 5 is a two-position four-way electrically controlled reversing valve. It is used to switch the system's flow distribution mode. Port B of the reversing valve 5 is connected to port A of the pressure reducing valve 18. The outlet of the auxiliary pump 15 is connected to port B of the pressure reducing valve 18. Port B of the pressure reducing valve 18 is equipped with a second pressure sensor 172 and a first flow meter 161. The suction port of the auxiliary pump 15 is connected to the outlet of the filter 14, and the inlet of the filter 14 is connected to the oil tank 13. Port A of the reversing valve 5 is also connected to the oil port of the magnetohydrodynamic accumulator 6, the inlet of the overflow valve 10, and the inlet of the shut-off valve 11. The oil port of the magnetohydrodynamic accumulator 6 is equipped with a third pressure sensor 173. The oil port of the magnetohydrodynamic accumulator 6 is connected to the inlet of the motor 8, and the inlet of the motor 8 is equipped with a second flow meter 161. Meter 162, motor 8 and variable load 9 are connected, the oil outlet of overflow valve 10 is connected to the hydraulic control port of pressure reducing valve 18, the oil outlet of overflow valve 10 is equipped with first pressure sensor 171, the oil outlet of shut-off valve 11 is connected to the oil inlet of sixth check valve 12, the oil outlet of sixth check valve 12 is connected to oil tank 13, when reversing valve 5 is in the upper position: the P port of reversing valve 5 is connected to the first oil port 331 and the second oil port 332 of dual-channel constant pressure end plunger pump 3 respectively, the T port of reversing valve 5 is connected to the third oil port 333, the output terminals of first pressure sensor 171, second pressure sensor 172 and third pressure sensor 173 are connected to the signal input terminal of controller respectively, and the control terminal of reversing valve 5 is connected to the signal output terminal of controller.

[0030] The dual-channel constant-pressure plunger pump 3 is equipped with a pump shaft 37. An annular cavity is formed between the pump shaft 37, the outer pump body 391, and the inner pump body 392. Several radially distributed plunger holes are provided in both the outer and inner pump bodies 391 and 392. The pump shaft 37 is fixed to a double reciprocating guide rail 35 via a spline connection within the annular cavity. Several sets of outer-discharge plungers 34 and inner-discharge plungers 36 are evenly arranged on the outer and inner rings of the double reciprocating guide rail 35, respectively. Each outer-discharge plunger 34 is installed in a plunger hole in the outer pump body 391, and each inner-discharge plunger 36 is installed in a plunger hole in the inner pump body 392. A first oil passage 311 is provided on one side of each plunger hole, and a second oil passage 312 is provided on the other side of each plunger hole. A first check valve 321 is installed in the first oil passage 311, and a second check valve 322 is installed in the second oil passage 312. The first oil passage 311, the second oil passage 312, and the corresponding plunger hole form a T-shaped channel. One end of the corresponding first check valve 321, the external plunger 34, and one end of the second check valve 322 form a sealed plunger cavity. The other end of each first check valve 321 is simultaneously connected to one end of the valve port of the high-speed switching valve 4, the fifth check valve 325, and the third oil passage 313. The other end of the valve port of the high-speed switching valve 4 is connected to the other end of the second check valve 322 through the fifth oil passage 315. Each second oil passage 312 and the fifth oil passage 315 is connected to the first oil port 331 through the annular oil chamber in the first distribution fluid 381. The inner pump body 392 is provided with a third oil passage 313 and a fourth oil passage 314 on one side of each plunger hole. A third check valve 323 is installed in the third oil passage 313, and a fourth check valve 324 is installed in the fourth oil passage 314. One end of the third check valve 323, one end of the fourth check valve 324, and the inner discharge plunger 36 form a sealed plunger. The other end of the third check valve 323 forms a sealed oil chamber with the high-speed switching valve 4, the fifth check valve 325, and the first check valve 321. A high-speed switching valve 4 and a fifth check valve 325 are installed in each of these oil chambers. The high-speed switching valve 4 is a two-position two-way electrically controlled bidirectional normally closed switching valve. The control terminal of the high-speed switching valve 4 is connected to the signal output terminal of the controller. Each fifth check valve 325 is connected to the third oil port 333 through the annular oil chamber in the third distribution fluid 383. Each fourth oil passage 314 is connected to the second oil port 332 through the annular oil chamber in the second distribution fluid 382.

[0031] When the reversing valve 5 is in the upper position, the test system is in pump mode. Motor 1 is connected to one end of the pump shaft 37 of the dual-channel constant pressure plunger pump 3, and angle encoder 2 is installed on the other end of the pump shaft 37. The output end of angle encoder 2 is connected to the signal input end of the controller. At this time, motor 1 controls the start and stop of the dual-channel constant pressure plunger pump 3 through pump shaft 37. When pump shaft 37 drives the double reciprocating guide rail 35 to rotate, the outer discharge plunger 34 and inner discharge plunger 36 of each group reciprocate in the corresponding plunger cavity. When the outer discharge plunger 34 draws oil, the inner discharge plunger 36 draws oil. When the outer plunger 34 discharges oil, the inner plunger 36 draws oil in. The first port 331 and second port 332 of the dual-flow constant-pressure plunger pump 3 are low-pressure suction ports, and the third port 333 is a high-pressure discharge port. The second check valve 322 and the fourth check valve 324 are configured as suction check valves. During the suction stroke of the outer plunger 34, oil enters the plunger chamber from the first port 331 through the second check valve 322. During the suction stroke of the inner plunger 36, oil enters the plunger chamber from the second port 332 through the fourth check valve 324. (High-speed...) One end of the valve port of the switching valve 4 is connected to the oil suction chamber of the first oil port 331. The first check valve 321, the third check valve 323, and the fifth check valve 325 are configured as oil discharge check valves. During the oil discharge stroke, the high-pressure oil from the outer discharge plunger 34 passes through the first check valve 321 and the fifth check valve 325 sequentially into the third oil port 333. During the oil discharge stroke, the high-pressure oil from the inner discharge plunger 36 passes through the third check valve 323 and the fifth check valve 325 sequentially into the third oil port 333. The other end of the valve port of the high-speed switching valve 4 is connected to the first check valve 321. 1. The oil discharge chambers formed by the third check valve 323 and the fifth check valve 325 are connected. When the reversing valve 5 is in the lower position, the test system is to test the flow distribution between the plunger motor 19 and the high-speed switching valve 4. An angle encoder 2 is installed on the plunger motor 19. At this time, the T port of the reversing valve 5 is connected to the valve port of the high-pressure end of the high-speed switching valve 4. The other valve port of the high-speed switching valve 4 is simultaneously connected to the plunger chamber of the plunger motor 19 and the valve port of the high-pressure end of the high-speed switching valve 4. The other valve port of the high-speed switching valve 4 is connected to the P port of the reversing valve 5.

[0032] The directional valve 5 is used to change the direction of oil flow. When the directional valve 5 is in the upper position, the test system is in pump mode, and when the directional valve 5 is in the lower position, the test system is in motor mode. The pressure reducing valve 18 is used to control the oil circuit pressure. In pump mode, the auxiliary pump 15 provides low-pressure oil to the first oil port 331 and the second oil port 332 of the dual-flow constant pressure end plunger pump 3 through the pressure reducing valve 18. In motor mode, the auxiliary pump 15 provides high-pressure oil to the high-speed switching valve 4 of the high-pressure end of the plunger motor 19. The magnetohydrodynamic accumulator 6 is used to reduce the pulsation of oil in the pipeline under the digital pump timing distribution strategy. The shut-off valve 11 is used to control the opening and closing of the oil circuit. When the test system is in pump mode, the oil circuit is closed, and when the test system is in motor mode, the oil circuit is open. The sixth check valve 12 is used to prevent oil in the oil tank 13 from being sucked back into the plunger chamber.

[0033] The magnetohydrodynamic accumulator 6 has a movable end cap 61 at its port. A baffle 63 is fixed inside the housing 62 of the magnetohydrodynamic accumulator 6. The outer shell 692 of the magnetohydrodynamic damper 65 is fixedly installed at the center of one side of the baffle 63. The push rod 693 of the magnetohydrodynamic damper 65 is fixedly connected to one side of the baffle 66. The baffle 66 can move inside the housing 62. Multiple springs 64 are fixedly connected between the baffle 63 and the baffle 66. The push rod 693 of the magnetohydrodynamic damper 67 is fixedly connected to the other side of the baffle 66. The push rod 693 of the magnetohydrodynamic damper 65 / magnetohydrodynamic damper 67 has a small through hole and an electromagnetic coil 69 inside. The rodless cavity and the rod cavity of the push rod 693 are filled with magnetohydrodynamic fluid 691. The outer shell 692 of the magnetohydrodynamic damper 67 is fixed to the bottom of the housing 62. The bottom of the housing 62 is provided with a connection port 68 for connection with the air pump 7.

[0034] The dual-flow constant-pressure plunger pump 3 controls the corresponding outer discharge plunger 34 and inner discharge plunger 36 to perform reciprocating cyclic motion via dual reciprocating guide rails 35. The suction and discharge strokes of each set of outer discharge plungers 34 and inner discharge plungers 36 are exactly opposite. When the test system is in pump mode, the staggered motion of the outer discharge plunger 34 and inner discharge plunger 36 ensures that the sealed oil chamber formed by the third check valve 323, high-speed switching valve 4, fifth check valve 325, and first check valve 321 is always at high pressure. Simultaneously, the high-speed switching valve 4 controls whether this sealed oil chamber is connected to the low-pressure annular oil chamber in the first oil port 331, directly affecting the output flow of the dual-flow constant-pressure plunger pump 3. The first check valve 321 also prevents the inner discharge plunger 36 from... High-pressure oil during the discharge stroke flows into the plunger cavity of the outer discharge plunger 34 during the suction stroke. The third check valve 323 also prevents high-pressure oil from flowing into the plunger cavity of the inner discharge plunger 36 during the suction stroke. The motor 1 controls the start and stop of the dual-channel constant pressure plunger pump 3. The angle encoder 2 is used to measure the rotation angle in real time. The first pressure sensor 171 is used to monitor the pressure at the pilot end of the pressure reducing valve 18. The second pressure sensor 172 is used to monitor the outlet pressure of the auxiliary pump 15. The third pressure sensor 173 is used to monitor the outlet pressure of the magnetohydrodynamic accumulator 6. The first flow meter 161 is used to monitor the flow rate of the auxiliary pump 15. The second flow meter 162 is used to monitor the flow rate through the motor 8.

[0035] When the magnetohydrodynamic accumulator 6 is working, there is a certain pressure of gas between the end cap 61 and the second baffle 66. The spring 64 is in a stretched state. The damping force provided by the first magnetohydrodynamic damper 65 is used to balance the spring force, and the damping force provided by the second magnetohydrodynamic damper 67 is balanced with the gas chamber pressure of the accumulator. At this time, the position of the second baffle 66 remains unchanged, and the magnetohydrodynamic accumulator 6 is in a stable state. The connection port 68 is used by the air pump 7 to pump gas into the secondary chamber of the accumulator to change the position of the second baffle 66. After the damper is energized, the magnetic field generated by the electromagnetic coil 69 controls the magnetohydrodynamic fluid 691 to arrange in a regular manner, thereby hindering the movement of the push rod 693. Different currents correspond to different resistance strengths.

[0036] All pressure sensors, flow meters, and high-speed switching valves in the system are required to have high response speeds to meet control functions.

[0037] Work process:

[0038] The first pressure sensor 171 monitors the pressure at the pilot end of the pressure reducing valve 18 in real time; the second pressure sensor 172 monitors the outlet pressure of the auxiliary pump 15 in real time; the third pressure sensor 173 monitors the outlet pressure of the magnetohydrodynamic accumulator 6 in real time; the first flow meter 161 monitors the flow rate of the auxiliary pump 15 in real time; the second flow meter 162 monitors the flow rate through the motor 8 in real time; when the reversing valve 5 is in different working positions, the test system will obtain pump mode and motor mode.

[0039] Pump mode: When the control reversing valve 5 is energized, the motor 1 drives the double reciprocating guide rail 35 of the dual-flow constant pressure end plunger pump 3 through the pump shaft 37. The double reciprocating guide rail 35 drives the outer discharge plunger 34 and the inner discharge plunger 36 to move alternately. At this time, the sealed oil discharge chamber formed by the other end of the third one-way valve 323, the high-speed switching valve 4, the fifth one-way valve 325, and the first one-way valve 321 in the dual-flow constant pressure end plunger pump 3 is filled with continuous high pressure. This high pressure oil can be connected to the magnetohydrodynamic accumulator 6 through the third oil port 333 through the fifth one-way valve 325, or it can return to the low pressure end of the first oil port 331 through the high-speed switching valve 4. The first oil port 331 is connected to the A port of the pressure reducing valve 18 through the reversing valve 5. The auxiliary pump 15 provides oil. The pressure reducing valve 18 is adjusted to make the first oil port 331 the low pressure end. At the same time, the shut-off valve 11 is closed to prevent the oil from entering the oil tank 13 through the sixth one-way valve 12.

[0040] To achieve constant flow distribution, the angle encoder 2 outputs the measured rotation angle of the pump shaft 37 to the controller. The controller generates a signal based on the rotation angle, the real-time speed of the motor 1, and the distribution algorithm. The purpose is to achieve constant flow output of the plunger pump. This signal controls the energization and de-energization of the high-speed switching valve 4. If the real-time speed of the motor 1 exceeds the set value, the signal generated by the controller will energize the high-speed switching valve 4 within a certain pump shaft 37 rotation time. The valve port of the high-speed switching valve 4 opens, and the high-pressure oil in the first oil passage 311 corresponding to the high-speed switching valve 4 will enter the low-pressure first oil port 331 through the fifth oil passage 315. Therefore, the flow rate entering the load end will decrease, thereby maintaining constant flow output. Since each oil discharge chamber is continuously under high pressure, the opening and closing delay time of the high-speed switching valve 4 remains stable.

[0041] The flow distribution algorithm can ensure a consistent average flow rate, but the flow pulsation is too large. Magnetohydrodynamic (MHD) accumulator 6 significantly reduces flow pulsation. When the high-pressure oil reaches MHD accumulator 6, the accumulator has already completed pre-charging. The initial charging pressure of MHD accumulator 6 needs to be consistent with the variable load 9. If the required operating load pressure for motor 8 and variable load 9 is 10 MPa, then the initial charging pressure of the accumulator is also 10 MPa. If the load pressure rises during flow distribution, to ensure a constant flow output from the system, the initial charging pressure of MHD accumulator 6 needs to be adjusted to be the same as the load pressure. According to the wavelet equation... The law of the ear: P1V1 = P2V2 can determine the chamber volume of the accumulator. To increase the initial charging pressure of the magnetohydrodynamic accumulator 6, the volume of the main chamber containing the spring 64 between the baffle 66 and the shell 62 needs to be reduced. For this purpose, the air pump 7 continuously pumps gas into the auxiliary chamber through the connection port 68. When the pressure of the pumped gas is the same as the current pressure of the magnetohydrodynamic accumulator 6, while pumping gas again, the damping force of the magnetohydrodynamic damper 67 is turned off by cutting off the power, and the current is reduced to reduce the damping force of the magnetohydrodynamic damper 65, thereby disrupting the balance with the spring force. The baffle 66 will then be pulled by the spring 64. The pressure difference between the force and the damping force of the magnetohydrodynamic damper 65 causes the device to slowly move towards the baffle 63. During this movement, gas needs to be slowly pumped into the secondary chamber to ensure that the pressure in the secondary chamber is the same as the pressure in the main chamber, until the baffle 66 moves to the correct position. At this point, the damping force of the magnetohydrodynamic damper 65 is balanced with the tension of the spring 64, greatly increasing the damping force of the magnetohydrodynamic damper 67 to balance the pressure in the main chamber, ensuring that the position of the baffle 66 remains unchanged. Subsequently, the secondary chamber completes the degassing. If the load pressure decreases during the flow distribution process, in order to ensure the constant flow output of the system, Boyle's law dictates that the magnetohydrodynamic fluid needs to be increased. The volume of the main chamber of the accumulator 6 is reduced. To achieve this, the current of the magnetohydrodynamic damper 65 is shut off, and the current of the magnetohydrodynamic damper 67 is reduced to decrease the damping force of the device. The high pressure in the main chamber and the difference between the spring force and the damping force of the magnetohydrodynamic damper 67 slowly push the baffle 66 away from the baffle 63 until the baffle 66 moves to the correct position. At this time, the damping force of the magnetohydrodynamic damper 65 is balanced with the tension of the spring 64, which greatly increases the damping force of the magnetohydrodynamic damper 67 and balances the pressure in the main chamber, ensuring that the position of the baffle 66 remains unchanged. The overflow valve 10 is set to the upper limit of the system pressure.

[0042] Motor mode: When the lower position of the control directional valve 5 is energized, the high-pressure oil generated by the auxiliary pump 15 reaches the T port of the directional valve 5 through the pressure reducing valve 18. The controller determines the relative position of the plunger by the rotation angle of the motor and generates a distribution signal according to the speed required by the plunger motor 19. Within a specific rotation angle range of the motor, the high-speed switching valve 4 on the high-pressure side is energized and opened, while the high-speed switching valve 4 on the low-pressure side is de-energized and closed. The high-pressure oil pushes the plunger to the downward dead point BDC through the high-pressure side high-speed switching valve 4, thereby driving the motor to rotate. At the same time, when the plunger moves to the upward dead point TDC, the high-speed switching valve 4 on the low-pressure side is energized to complete the oil discharge stroke of the plunger. The magnetohydrodynamic accumulator 6 is depressurized, the shut-off valve 11 is opened, and the oil discharged from the plunger reaches the sixth check valve 12 after passing through the high-speed switching valve 4 on the low-pressure side, and finally reaches the oil tank 13. The distribution signal generated by the controller controls the proportion of time that the high-pressure oil participates in the downward dead point BDC movement of the plunger, thereby completing the speed regulation.

[0043] As can be seen from the above structure, the present invention mainly consists of a dual-channel constant-pressure plunger pump 3, a high-speed switching valve 4, a directional valve 5, and a pressure-reducing valve 18. The constant-pressure plunger end of the dual-channel constant-pressure plunger pump 3 increases the flow distribution accuracy of the high-speed switching valve 4, reducing the design difficulty of the flow distribution strategy; the magnetohydrodynamic accumulator 6 reduces the flow pulsation of the hydraulic system under the time-sequential flow distribution strategy, solving the problem of constant flow distribution under varying engineering conditions; the directional valve 5 and pressure-reducing valve 18 improve the versatility of the testing system; and the real-time monitoring by the three pressure sensors and two flow meters determines the working pressure and flow rate of the magnetohydrodynamic accumulator 6 and pressure-reducing valve 18, allowing for corresponding control measures.

[0044] Please see Figure 6 By controlling the current to adjust the motor speed, the flow distribution test system of this invention in pump mode is tested. The controller, constant pressure pump, high-speed switching valve 4, and accumulator regulate the flow rate within the hydraulic system to obtain the output flow rate of the flow distribution system. Clearly, the test system of this invention can achieve constant flow distribution.

[0045] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to any specific implementation. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A plunger mechanical flow distribution and testing system based on a constant pressure flow channel, comprising a plunger end flow output component, the plunger end flow output component consisting of a motor (1), a dual-flow channel constant pressure end plunger pump (3), a high-speed switching valve (4), a magnetohydrodynamic accumulator (6), a motor (8), a variable load (9), and a controller, characterized in that, It also includes a flow distribution mode control component, which includes a reversing valve (5), a relief valve (10), a shut-off valve (11), a sixth check valve (12), an oil tank (13), an auxiliary pump (15), and a pressure reducing valve (18). The dual-channel constant pressure end plunger pump (3) is provided with a pump shaft (37). The pump shaft (37) forms an annular cavity with the outer pump body (391) and the inner pump body (392). Several radially distributed plunger holes are provided in the outer pump body (391) and the inner pump body (392). The pump shaft (37) in the annular cavity is fixed to the double reciprocating guide rail (35) by spline connection. Several sets of outer drain plungers (34) and inner drain plungers (36) are evenly arranged on the outer and inner rings of the double reciprocating guide rail (35). The outer pump body (391) has a first oil passage (311) on one side of each plunger hole and a second oil passage (312) on the other side of the plunger hole. The inner pump body (392) has a third oil passage (313) and a fourth oil passage (314) on one side of each plunger hole. The A port of the reversing valve (5) is connected to the oil port of the magnetohydrodynamic accumulator (6), the oil inlet of the overflow valve (10), and the oil inlet of the shut-off valve (11), respectively. The oil port of the magnetohydrodynamic accumulator (6) is equipped with a third pressure sensor (173). The oil port of the magnetohydrodynamic accumulator (6) is connected to the oil inlet of the motor (8). The motor (8) is connected to the variable load (9).

2. The plunger mechanical flow distribution and testing system based on a constant pressure flow channel according to claim 1, characterized in that, Each external discharge plunger (34) is installed in the plunger hole of the external pump body (391), and each internal discharge plunger (36) is installed in the plunger hole of the internal pump body (392). When the pump shaft (37) drives the double reciprocating guide rail (35) to rotate, each set of external discharge plungers (34) and internal discharge plungers (36) reciprocate periodically along the double reciprocating guide rail (35) in the corresponding plunger hole. When each set of external discharge plungers (34) draws oil, the corresponding internal discharge plunger (36) is in the oil discharge stroke. The oil suction and discharge strokes of the two are opposite.

3. The plunger mechanical flow distribution and testing system based on a constant pressure flow channel according to claim 2, characterized in that, A first check valve (321) is installed in the first oil passage (311), and a second check valve (322) is installed in the second oil passage (312). The first oil passage (311), the second oil passage (312), and the corresponding plunger hole form a T-shaped channel. One end of the corresponding first check valve (321), the external plunger (34), and one end of the second check valve (322) form a sealed plunger cavity. The other end of each first check valve (321) is simultaneously connected to one end of the valve port of the high-speed switching valve (4), the fifth check valve (325), and the third oil passage (313). The other end of the valve port of the high-speed switching valve (4) is connected to the other end of the second check valve (322) through the fifth oil passage (315). Each second oil passage (312) and the fifth oil passage (315) are connected to the first oil port through the annular oil cavity in the first distribution fluid (381). (331) Connected; a third check valve (323) is installed in the third oil passage (313), and a fourth check valve (324) is installed in the fourth oil passage (314). One end of the third check valve (323), one end of the fourth check valve (324), and the inner plunger (36) form a sealed plunger cavity. The other end of the third check valve (323) forms a sealed oil cavity with the high-speed switching valve (4), the fifth check valve (325), and the first check valve (321). A high-speed switching valve (4) and a fifth check valve (325) are installed in each of these oil cavities. Each fifth check valve (325) is connected to the third oil port (333) through the annular oil cavity in the third distribution fluid (383). Each fourth oil passage (314) is connected to the second oil port (332) through the annular oil cavity in the second distribution fluid (382).

4. The plunger mechanical flow distribution and testing system based on a constant pressure flow channel according to claim 3, characterized in that, The motor (8) is equipped with a second flow meter (162) at its oil inlet. The outlet of the overflow valve (10) is connected to the hydraulic port of the pressure reducing valve (18). The outlet of the overflow valve (10) is equipped with a first pressure sensor (171). The outlet of the shut-off valve (11) is connected to the inlet of the sixth check valve (12). The outlet of the sixth check valve (12) is connected to the oil tank (13). The B port of the reversing valve (5) is connected to the A port of the pressure reducing valve (18). The B port of the pressure reducing valve (18) is connected to the outlet of the auxiliary pump (15). The B port of the pressure reducing valve (18) is equipped with a second pressure sensor (172) and a first flow meter (161). When the reversing valve (5) is in the upper position, the P port of the reversing valve (5) is connected to the first oil port (331) and the second oil port (332) respectively. The T port of the reversing valve (5) is connected to the third... The oil port (333) is connected, and the port of the magnetohydrodynamic accumulator (6) is provided with a movable end cap (61). Inside the housing (62) of the magnetohydrodynamic accumulator (6), a baffle (63) is fixed. The outer shell (692) of the magnetohydrodynamic damper (65) is fixedly installed at the center of one side of the baffle (63). The push rod (693) of the magnetohydrodynamic damper (65) is fixedly connected to one side of the baffle (66). The baffle (66) moves inside the housing (62). Multiple springs (64) are fixedly connected between the baffle (63) and the baffle (66). The push rod (693) of the magnetohydrodynamic damper (67) is fixedly connected to the other side of the baffle (66). The outer shell (692) of the magnetohydrodynamic damper (67) is fixed at the bottom of the housing (62). The bottom of the housing (62) is provided with a connection port (68) and an air pump (7).

5. The plunger mechanical flow distribution and testing system based on a constant pressure flow channel according to claim 4, characterized in that, The first port (331) and the second port (332) of the dual-channel constant pressure plunger pump (3) are low-pressure suction ports, and the third port (333) is a high-pressure discharge port. The second check valve (322) and the fourth check valve (324) are configured as suction check valves. Low-pressure oil enters the plunger chamber of the outer discharge plunger (34) from the first port (331) through the second check valve (322), and low-pressure oil enters the plunger chamber of the inner discharge plunger (36) from the second port (332) through the fourth check valve (324). One end of the valve port of the high-speed switching valve (4) is connected to the suction chamber of the first port (331). The first check valve (321), the third check valve (323), and the fifth check valve (325) are configured as oil discharge check valves. The high-pressure oil in the plunger chamber of the outer discharge plunger (34) flows into the third oil port (333) through the first check valve (321) and the fifth check valve (325). The high-pressure oil in the plunger chamber of the inner discharge plunger (36) flows into the third oil port (333) through the third check valve (323) and the fifth check valve (325). The other end of the valve port of the high-speed switching valve (4) is connected to the oil discharge chamber formed by the first check valve (321), the third check valve (323), and the fifth check valve (325).

6. The plunger mechanical flow distribution and testing system based on a constant pressure flow channel according to claim 5, characterized in that, When the reversing valve (5) is in the lower position, the test system is to test the flow distribution between the piston motor (19) and the high-speed switching valve (4). An angle encoder (2) is installed on the piston motor (19). At this time, the T port of the reversing valve (5) is connected to the valve port of the high-pressure end of the high-speed switching valve (4). The other valve port of the high-speed switching valve (4) is simultaneously connected to the piston chamber of the piston motor (19) and the valve port of the low-pressure end of the high-speed switching valve (4). The other valve port of the high-speed switching valve (4) is connected to the P port of the reversing valve (5).

7. The plunger mechanical flow distribution and testing system based on a constant pressure flow channel according to claim 6, characterized in that, The push rod (693) of the magnetohydrodynamic damper one (65) / magnetohydrodynamic damper two (67) has a small through hole and an electromagnetic coil (69) inside. The rodless cavity and the rod cavity of the push rod (693) are filled with magnetohydrodynamic fluid (691).

8. The plunger mechanical flow distribution and testing system based on a constant pressure flow channel according to claim 7, characterized in that, The motor (1) is connected to one end of the pump shaft (37) of the dual-channel constant pressure plunger pump (3), and the angle encoder (2) is installed at the other end of the pump shaft (37). The output ends of the first pressure sensor (171), the second pressure sensor (172), the third pressure sensor (173), and the angle encoder (2) are respectively connected to the signal input end of the controller. The control ends of the high-speed switching valve (4) and the reversing valve (5) are respectively connected to the signal output end of the controller.

9. A plunger mechanical flow distribution and testing system based on a constant pressure flow channel according to claim 8, characterized in that, The high-speed switching valve (4) is a two-position two-way electrically controlled bidirectional normally closed switching valve, the reversing valve (5) is a two-position four-way electrically controlled reversing valve, the oil inlet of the auxiliary pump (15) is connected to the oil outlet of the filter (14), and the oil inlet of the filter (14) is connected to the oil tank (13).

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