A hydraulic pump pressure control mechanism

Abstract

This invention relates to the field of hydraulic pumps. The invention discloses a hydraulic pump pressure control mechanism, comprising a hydraulic pump, with an electromagnetic on / off valve, a pressure compensation valve, and a hydraulically controlled shut-off valve mounted on the pump's housing. The electromagnetic on / off valve is connected to the pressure compensation valve and the hydraulic pump's drain oil passage via a first combined oil circuit, and to the pressure compensation valve and the hydraulic pump's inlet via a third combined oil circuit. The pressure compensation valve is connected to the electromagnetic on / off valve and the hydraulically controlled shut-off valve via a second combined oil circuit, and to the working chamber of the hydraulic pump's follower piston via a follower piston chamber oil circuit. The bottom of the hydraulically controlled shut-off valve is connected to the hydraulic pump's drain oil passage, and is connected to the working chamber of the follower piston via the second combined oil circuit and the first... A combined oil circuit is connected to the outlet of the hydraulic pump; the electromagnetic on / off valve has a P port, an R port, and a C port. The P port is connected to the first combined oil circuit, the R port is connected to the third combined oil circuit, and the C port is connected to the second combined oil circuit; the pressure compensation valve has a D port, an E port, a F port, a G chamber, and a first spring chamber. The D port is connected to the follower piston chamber oil circuit, the E port is connected to the first combined oil circuit, the F port and the first spring chamber are connected to the third combined oil circuit, and the G chamber is connected to the second combined oil circuit; the hydraulically controlled shut-off valve has a second spring chamber and a bore. The second spring chamber is connected to the second combined oil circuit, and the bore is connected to the first combined oil circuit. This invention solves the problem of wasted engine power caused by the hydraulic pump still outputting hydraulic oil with a certain pressure and flow rate when the hydraulic pump is unloaded; it also solves the problem that when downstream users of the hydraulic pump experience damage or oil leakage, the hydraulic pump continues to run with the engine, continuously outputting hydraulic oil with a certain pressure and flow rate, which can easily lead to the complete leakage of oil in the hydraulic system and oil tank, resulting in the paralysis of the hydraulic system and, in severe cases, endangering aircraft safety.

Description

Technical Field

[0001] This invention relates to the field of hydraulic pump technology, and in particular to a hydraulic pump outlet unloading and shut-off interlocking control mechanism. Background Technology

[0002] The hydraulic pump is the core component of the hydraulic system. It extracts torque from the prime mover (engine), converts mechanical energy into hydraulic energy, and provides high-pressure hydraulic energy for the aircraft hydraulic system.

[0003] Chinese Patent Publication No. CN112166674 B discloses a pressure regulating mechanism for a constant pressure hydraulic pump, which mainly consists of a regulating valve, a follower piston, an electromagnet, a swashplate, and an oil circuit. This regulating mechanism integrates the pressure regulating mechanism and the hydraulic pump into one unit, changing the rated pressure of the hydraulic system from a single pressure to a two-stage pressure, which can be freely switched. To reduce engine power loss, the high and low stable constant pressure hydraulic oil supplied to the hydraulic system can be adjusted at any time according to different actual flight conditions of the aircraft.

[0004] This patent reduces the power extracted from the engine by the hydraulic pump to some extent by lowering the outlet pressure of the hydraulic pump, which is beneficial for engine starting. However, since the hydraulic pump still outputs hydraulic oil with a certain pressure and flow rate when unloaded, it results in a waste of engine power.

[0005] Furthermore, when downstream users of the hydraulic pump experience malfunctions such as damage or oil leaks, the hydraulic pump, which runs continuously with the engine and outputs hydraulic oil at a certain pressure and flow rate, is prone to causing the hydraulic system and oil tank to leak out completely, leading to the paralysis of the hydraulic system and, in severe cases, endangering aircraft safety. Summary of the Invention

[0006] To solve the above-mentioned technical problems, the present invention provides a hydraulic pump pressure control mechanism, including a hydraulic pump. The hydraulic pump housing is equipped with an electromagnetic on / off valve, a pressure compensation valve, and a hydraulically controlled shut-off valve. The electromagnetic on / off valve is connected to the pressure compensation valve and the hydraulic pump discharge oil passage through a first combined oil circuit, and to the pressure compensation valve and the hydraulic pump inlet through a third combined oil circuit. The pressure compensation valve is connected to the electromagnetic on / off valve and the hydraulically controlled shut-off valve through a second combined oil circuit, and to the follower piston working chamber of the hydraulic pump through a follower piston chamber oil circuit. The bottom of the hydraulically controlled shut-off valve is connected to the hydraulic pump discharge oil passage, and to the hydraulic pump outlet through the second combined oil circuit and the first combined oil circuit.

[0007] The electromagnetic on / off valve has a P port, an R port, and a C port. The P port is connected to the first combined oil circuit, the R port is connected to the third combined oil circuit, and the C port is connected to the second combined oil circuit. The pressure compensation valve has a D port, an E port, a F port, a G chamber, and a first spring chamber. The D port is connected to the follower piston chamber oil circuit, the E port is connected to the first combined oil circuit, the F port and the first spring chamber are connected to the third combined oil circuit, and the G chamber is connected to the second combined oil circuit. The hydraulically controlled shut-off valve has a second spring chamber and a shaped orifice. The second spring chamber is connected to the second combined oil circuit, and the shaped orifice is connected to the first combined oil circuit.

[0008] When the electromagnetic on / off valve is not energized, port R is connected to port C; when the electromagnetic on / off valve is energized, port P is connected to port C.

[0009] The pressure compensation valve is further provided with a differential pressure push rod, one end of which is connected to a differential pressure piston, and the other end is connected to the pressure compensation valve core; a pressure compensation valve sleeve is fitted over the pressure compensation valve core, and one end of the pressure compensation valve core is connected to a second spring seat; an adjusting screw sleeve is provided outside the second spring seat, and an adjusting nut is connected to the bottom of the adjusting screw sleeve; a first spring seat is provided inside the adjusting screw sleeve, and the first spring seat and the second spring seat are connected by a first spring to form a first spring cavity.

[0010] The differential pressure piston is located inside chamber G, and the pressure adjusting screw sleeve is connected to the outer shell.

[0011] The pressure compensation valve core is provided with a working shoulder, port D works in conjunction with the working shoulder, and port E is connected to the left side of the working shoulder.

[0012] The hydraulically controlled shut-off valve is further provided with a hydraulically controlled shut-off valve core, and a hydraulically controlled shut-off valve sleeve is fitted over the hydraulically controlled shut-off valve core; one end of the hydraulically controlled shut-off valve sleeve is connected to an end cap, and a second spring is provided inside the hydraulically controlled shut-off valve core to form a second spring cavity.

[0013] The valve sleeve of the hydraulic control plug valve is located inside the housing, and the end cap is connected to the housing.

[0014] The orifice is set on the side wall of the hydraulic control plug valve sleeve, and the valve core of the hydraulic control plug valve and the valve sleeve of the hydraulic control plug valve are clearance fit.

[0015] Compared with the prior art, this invention solves the problem of wasted engine power caused by the hydraulic pump still outputting hydraulic oil with a certain pressure and flow rate when the hydraulic pump is unloaded. At the same time, it solves the problem that when downstream users of the hydraulic pump experience malfunctions such as damage or oil leakage, the hydraulic pump continues to output hydraulic oil with a certain pressure and flow rate as the engine runs, which can easily lead to the complete leakage of oil in the hydraulic system and oil tank, resulting in the paralysis of the hydraulic system and endangering aircraft safety in severe cases.

[0016] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0017] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0018] Figure 1 This is a schematic diagram of the structure of the present invention;

[0019] Figure 2 yes Figure 1 Schematic diagram of the electromagnetic on / off valve;

[0020] Figure 3 yes Figure 1 Schematic diagram of the structure of a medium-pressure compensation valve;

[0021] Figure 4 yes Figure 1 A schematic diagram of the structure of a centrally controlled shut-off valve.

[0022] In the diagram: 1-Solenoid on / off valve, 11-P port, 12-R port, 13-C port, 2-Pressure compensation valve, 21-D port, 22-E port, 23-F port, 24-G chamber, 25-Differential pressure piston, 26-Differential pressure push rod, 27-Pressure compensation valve sleeve, 28-Adjusting screw sleeve, 29-Adjusting nut, 210-First spring seat, 211-First spring, 212-Second spring seat, 213-Pressure compensation valve core, 214-First spring chamber, 3- Hydraulic control plug valve, 31-Hydraulic control plug valve core, 32-Hydraulic control plug valve sleeve, 33-Second spring chamber, 34-End cap, 35-Second spring, 36-Type hole, 4-Hydraulic pump outlet, 5-Hydraulic pump inlet, 6-Hydraulic pump return port, 7-First combined oil circuit, 8-Second combined oil circuit, 9-Follower piston chamber oil circuit, 100-Outer shell, 110-Third combined oil circuit, 120-Hydraulic pump discharge oil passage, 130-Follower spring, 140-Follower piston. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the embodiments of this invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details are presented in the embodiments of this invention to facilitate a better understanding of this application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments. The division of the following embodiments is for ease of description and should not constitute any limitation on the specific implementation of this invention. The embodiments can be combined with and referenced by each other without contradiction.

[0024] Example 1

[0025] like Figures 1-4 The hydraulic pump pressure control mechanism shown mainly includes an electromagnetic on / off valve 1, a pressure compensation valve 2, a hydraulic control shut-off valve 3, a first combined oil circuit 7, a second combined oil circuit 8, and a third combined oil circuit 110.

[0026] The electromagnetic on / off valve 1 is installed on the housing 100 of the hydraulic pump and is provided with a P port 11, an R port 12, and a C port 13. The P port 11 is connected to the first combined oil circuit 7, the R port 12 is connected to the third combined oil circuit 110, and the C port 13 is connected to the second combined oil circuit 8.

[0027] Specifically, when the electromagnetic on / off valve 1 is not energized, port R12 and port C13 are connected; when the electromagnetic on / off valve 1 is energized, port P11 and port C13 are connected.

[0028] The pressure compensation valve 2 is installed on the housing 100 of the hydraulic pump and has ports D 21, E 22, F 23, and G 24. A differential pressure piston 25, a differential pressure push rod 26, and a pressure compensation valve core 213 are sequentially arranged within these ports. The differential pressure piston 25, differential pressure push rod 26, and pressure compensation valve core 213 are clearance-fitted with their corresponding mounting holes, allowing for flexible movement within the holes while maintaining good oil sealing performance. The mounting hole for the pressure compensation valve core 213 is located within the pressure compensation valve sleeve 27, and the mounting hole for the differential pressure push rod 26 is located on the housing 100 of the hydraulic pump. The pressure compensation valve 2 is connected to the housing 100 of the hydraulic pump via the threads on the adjusting sleeve 28. 00 Fixed connection, pressure adjusting nut 29 is fixedly connected to pressure adjusting sleeve 28, and a first spring seat 210, a first spring 211, and a second spring seat 212 are provided in the cavity of pressure adjusting sleeve 28. One end of pressure compensation valve core 213 is in contact with the second spring seat 212, and the first spring seat 210 is in contact with pressure adjusting nut 29. D port 21 is connected to the oil passage 9 of the follow-up piston chamber of the hydraulic pump and is adapted to the working shoulder on the pressure compensation valve core 213. E port 22 is connected to the first combined oil passage 7 and is connected to the left side of the working shoulder on the pressure compensation valve core 213. F port 23 is connected to the first spring cavity 214 through the third combined oil passage 11.

[0029] The hydraulically controlled shut-off valve 3 is installed on the housing 100 of the hydraulic pump. Its bottom is connected to the hydraulic pump drain oil passage 120 of the hydraulic pump, and its side is connected to the first combined oil passage 7 through a shaped hole 36. The shaped hole 36 is set on the valve sleeve 32 of the hydraulically controlled shut-off valve. The valve sleeve 32 of the hydraulically controlled shut-off valve is installed in the housing 100 of the hydraulic pump. The end cap 34 is fixedly connected to the housing 100 of the hydraulic pump, pressing the valve sleeve 32 of the hydraulically controlled shut-off valve tightly. The valve core 31 of the hydraulically controlled shut-off valve and the valve sleeve 32 of the hydraulically controlled shut-off valve are clearance-fitted, allowing flexible movement within them, while also having good oil sealing performance. The valve core 31 of the hydraulically controlled shut-off valve is provided with a second spring cavity 33, and a second spring 35 is installed in the second spring cavity 33. The second spring cavity 33 is connected to the second combined oil passage 8.

[0030] The first combination oil circuit 7 is connected to the hydraulic pump discharge oil passage 120 of the hydraulic pump, and is also connected to the P port 11 on the solenoid on / off valve 1, the D port 21 on the pressure compensation valve 2, and the orifice 36 on the valve sleeve 32 of the hydraulic control plug valve.

[0031] The second combination oil circuit 8 is connected to port C 13 on the solenoid on / off valve 1, chamber G 24 on the pressure compensation valve 2, and the second spring chamber 33 of the hydraulic control shut-off valve 3.

[0032] The third combination oil circuit 110 is connected to the hydraulic pump inlet 5, and is also connected to the R port 12 on the solenoid on / off valve 1, the F port 23 on the pressure compensation valve 2, and the first spring chamber 214.

[0033] Example 2

[0034] The hydraulic pump, comprising hydraulic pump outlet 4, hydraulic pump inlet 5, hydraulic pump return port 6, follower piston chamber oil passage 9, housing 100, hydraulic pump discharge oil passage 120, follower spring 130, follower piston 140, works in conjunction with solenoid on / off valve 1, pressure compensation valve 2, hydraulic control shut-off valve 3, first combined oil passage 7, second combined oil passage 8, and second combined oil passage 110, as detailed below:

[0035] Hydraulic pump outlet 4 is connected to the load and operates with high-pressure oil; hydraulic pump inlet 5 is connected to the oil tank and operates with the oil tank pressure; hydraulic pump return port 6 is connected to the oil tank, and the oil returned from the casing 100 is cooled by the heat dissipation and cooling system before returning to the oil tank.

[0036] In the initial assembly state, there is no pressure in the oil passage 9 of the follower piston chamber, and it is in the maximum swing angle position under the action of the follower spring 130; the valve core 31 of the hydraulic control shut-off valve is in the closed position under the spring force of the second spring 35, and the valve core 31 of the hydraulic control shut-off valve cuts off the connection between the hydraulic pump discharge oil passage 120 and the first combined oil passage 7.

[0037] When the electromagnetic on / off valve 1 is not energized, port R 12 and port C 13 are connected, the second combined oil circuit 8 and the third combined oil circuit 110 are connected, and the G chamber 24 of the pressure compensation valve 2 and the second spring chamber 33 of the hydraulic control plug valve 3 are connected to the hydraulic pump inlet 5 through the second combined oil circuit 8 and the third combined oil circuit 110, and the hydraulic pump is in normal working condition; the pressure of the hydraulic pump outlet 4 acts on the pressure compensation valve core 213 through the first combined oil circuit 7 and the E port 22 of the pressure compensation valve 2. When the pressure of the hydraulic pump outlet 4 is less than or equal to the maximum full flow pressure P1, the D port 21 and the E port 22 of the pressure compensation valve 2 cannot communicate, and the high-pressure oil cannot enter the follower piston chamber oil circuit 9. Under the action of the follower spring 130, the hydraulic pump is in the maximum swing angle position, and the hydraulic pump is in a high flow working state; when the pressure of the hydraulic pump outlet 4 reaches the rated pressure P1, the pressure compensation valve 2 is in normal working condition. When the pressure is constant at P2, port D21 and port E22 of pressure compensation valve 2 are connected, and high-pressure oil enters the oil circuit 9 of the follower piston chamber. The high-pressure oil pushes the follower piston 140 to overcome the action of the follower spring 130, so that the hydraulic pump is in the zero swing angle position and the hydraulic pump is in the zero flow working state. If the pressure of the hydraulic pump outlet 4 is between the maximum full flow pressure P1 and the rated pressure P2, due to the feedback adjustment of the hydraulic pump outlet 4 pressure, the swing angle of the hydraulic pump will be between the zero swing angle and the maximum swing angle, and the hydraulic pump will output a certain flow of high-pressure oil. Under the action of the hydraulic pump outlet 4 pressure, the valve core 31 of the hydraulic control blocking valve overcomes the spring force and the hydraulic pressure of the second spring chamber 33 and is in the open position. The hydraulic pump discharge oil passage 120 is connected to the first combined oil circuit 7 through the hole 36 set on the valve sleeve 32 of the hydraulic control blocking valve.

[0038] For aviation hydraulic pumps, the rated pressure P2 can be 15MPa, 21MPa, 28MPa or 35MPa; under normal circumstances, the maximum full flow pressure P1 is 0 to 138MPa lower than the rated pressure P2.

[0039] When the solenoid on / off valve 1 is energized, port P11 and port C13 are connected, the second combined oil circuit 8 is connected to the first combined oil circuit 7, the G chamber 24 of the pressure compensation valve 2 and the second spring chamber 33 of the hydraulic control shut-off valve 3 are connected to the hydraulic pump outlet 4 through the second combined oil circuit 8 and the first combined oil circuit 7, and the hydraulic pump is in an unloaded working state; the hydraulic pump outlet pressure acts on the differential pressure piston 25 through the G chamber 24 of the pressure compensation valve 2 via the first combined oil circuit 7, and the hydraulic pressure is transmitted to the valve core 213 of the pressure compensation valve through the differential pressure push rod 26. When the pressure at the hydraulic pump outlet 4 reaches the unload pressure P3, the pressure compensation valve 2... The upper D port 21 is connected to the E port 22. High-pressure oil enters the oil circuit 9 of the follower piston chamber. The high-pressure oil pushes the follower piston 140 to overcome the follower spring 130, so that the hydraulic pump is in a zero swing angle position and the hydraulic pump is in a zero flow working state. The hydraulic pressure acting on the valve core 31 of the hydraulic control shut-off valve through the second spring chamber 33 is balanced with the hydraulic pressure on the valve core 31 of the hydraulic control shut-off valve through the hydraulic pump discharge oil passage 120. Under the action of the spring force of the second spring 35, the valve core 31 of the hydraulic control shut-off valve is in the closed position, and the valve core 31 of the hydraulic control shut-off valve cuts off the connection between the hydraulic pump discharge oil passage 120 and the first combined oil circuit 7.

[0040] Because the geometric diameter of the differential pressure piston 25 is several times that of the valve core 213 of the pressure compensation valve, the rated pressure P2 of the hydraulic pump is several times that of the unloading pressure P3. When the hydraulic pump is in the unloading state, the outlet pressure drops significantly, greatly reducing the power extracted by the hydraulic pump from the engine, which is beneficial for engine starting. However, since the hydraulic pump still outputs hydraulic oil with a certain pressure and flow rate in the unloading state, it still results in a waste of engine power.

[0041] To address this issue, the present invention includes a first combined oil circuit 7 and a second combined oil circuit 8. The connection between the second combined oil circuit 8 and the first combined oil circuit 7 is controlled by an electromagnetic on / off valve 1. The pressure of the G chamber 24 on the pressure compensation valve 2 and the second spring chamber 33 on the hydraulic control shut-off valve 3 are interlocked through the second combined oil circuit 8. This achieves unloading control of the hydraulic pump outlet pressure and interlocking control of the hydraulic pump output oil shut-off, so that the outlet oil circuit is shut off when the hydraulic pump is unloaded, forming a closed-loop circulation of the hydraulic pump, thereby achieving the shut-off of the hydraulic pump outlet oil circuit under unloading conditions.

[0042] As described above, this invention enables the shut-off of the hydraulic pump outlet oil circuit under unloaded conditions, avoiding the situation where the hydraulic pump still outputs hydraulic oil with a certain pressure and flow rate under unloaded conditions. This further reduces engine power waste, is more conducive to the secondary restart of the engine after an in-flight shutdown, and is also more conducive to the ground start of the engine.

[0043] Furthermore, when downstream users of the hydraulic pump experience malfunctions such as damage or oil leaks, the hydraulic pump, which runs continuously with the engine and outputs hydraulic oil at a certain pressure and flow rate, is prone to causing the hydraulic system and oil tank to leak out completely, leading to the paralysis of the hydraulic system and, in severe cases, endangering aircraft safety.

[0044] To address this issue, this invention interlocks the unloading and hydraulic pump output oil circulation modes, enabling the shut-off of the hydraulic pump outlet oil circuit during unloading. When downstream users of the hydraulic pump experience damage or oil leakage, the pilot manually activates the solenoid on / off valve to unload the hydraulic pump, thus shutting off the hydraulic pump outlet oil circuit during unloading. This effectively prevents the hydraulic system and oil tank from leaking out uncontrollably, significantly improving the safety of the hydraulic system and the aircraft.

[0045] Those skilled in the art will understand that the above embodiments can be modified in form and detail in practical applications without departing from the spirit and scope of the invention.

Claims

1. A hydraulic pump pressure control mechanism comprising a hydraulic pump, characterized by: The housing (100) of the hydraulic pump is equipped with an electromagnetic on / off valve (1), a pressure compensation valve (2), and a hydraulic control shut-off valve (3). The electromagnetic on / off valve (1) is connected to the pressure compensation valve (2) and the hydraulic pump drain oil passage (120) through the first combined oil passage (7), and is connected to the pressure compensation valve (2) and the hydraulic pump inlet (5) through the third combined oil passage (110). The pressure compensation valve (2) is connected to the electromagnetic on / off valve (1) and the hydraulic control shut-off valve (3) through the second combined oil passage (8), and is connected to the follower piston working chamber of the hydraulic pump through the follower piston chamber oil passage (9). The bottom of the hydraulic control shut-off valve (3) is connected to the hydraulic pump drain oil passage (120), and is connected to the hydraulic pump outlet (4) through the second combined oil passage (8) and the first combined oil passage (7). The electromagnetic on / off valve (1) is provided with a P port (11), an R port (12), and a C port (13). The P port (11) is connected to the first combined oil circuit (7), the R port (12) is connected to the third combined oil circuit (110), and the C port (13) is connected to the second combined oil circuit (8). The pressure compensation valve (2) is provided with a D port (21), an E port (22), an F port (23), a G chamber (24), and a first spring chamber (214). The D port (21) is connected to the following... The piston chamber oil passage (9) is connected, port E (22) is connected to the first combined oil passage (7), port F (23) and the first spring chamber (214) are connected to the third combined oil passage (110), and chamber G (24) is connected to the second combined oil passage (8); the hydraulic control plug valve (3) is provided with a second spring chamber (33) and a bore (36), the second spring chamber (33) is connected to the second combined oil passage (8), and the bore (36) is connected to the first combined oil passage (7).

2. The hydraulic pump pressure control mechanism of claim 1, wherein: When the electromagnetic on / off valve (1) is not energized, port R (12) is connected to port C (13); when the electromagnetic on / off valve (1) is energized, port P (11) is connected to port C (13).

3. The hydraulic pump pressure control mechanism of claim 1, wherein: The pressure compensation valve (2) is also provided with a differential pressure push rod (26), one end of which is connected to a differential pressure piston (25), and the other end is connected to a pressure compensation valve core (213); the pressure compensation valve core (213) is covered by a pressure compensation valve sleeve (27), and one end of the pressure compensation valve core (213) is connected to a second spring seat (212); the second spring seat (212) is provided with a pressure adjusting screw sleeve (28), and the bottom of the pressure adjusting screw sleeve (28) is connected to a pressure adjusting nut (29); the pressure adjusting screw sleeve (28) is provided with a first spring seat (210), and the first spring seat (210) and the second spring seat (212) are connected by a first spring (211) to form a first spring cavity (214).

4. The hydraulic pump pressure control mechanism of claim 3, wherein: The differential pressure piston (25) is located in the G chamber (24), and the pressure regulating screw sleeve (28) is connected to the outer shell (100).

5. The hydraulic pump pressure control mechanism of claim 3, wherein: The pressure compensation valve core (213) is provided with a working shoulder, and port D (21) works in conjunction with the working shoulder, and port E (22) is connected to the left side of the working shoulder.

6. The hydraulic pump pressure control mechanism of claim 1, wherein: The hydraulic control occlusion valve (3) is further provided with a hydraulic control occlusion valve spool (31), and the hydraulic control occlusion valve spool (31) is sleeved with a hydraulic control occlusion valve sleeve (32); one end of the hydraulic control occlusion valve sleeve (32) is connected with an end cover (34), the hydraulic control occlusion valve spool (31) is provided with a second spring (35), and a second spring cavity (33) is formed.

7. The hydraulic pump pressure control mechanism of claim 6, wherein: The hydraulic control occlusion valve sleeve (32) is arranged in the shell (100), and the end cover (34) is connected with the shell (100).

8. The hydraulic pump pressure control mechanism of claim 6, wherein: The type hole (36) is arranged on the side wall of the hydraulic control occlusion valve sleeve (32), and the hydraulic control occlusion valve spool (31) is in clearance fit with the hydraulic control occlusion valve sleeve (32).

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