A hydraulic test system for testing VCU devices

Abstract

The present invention provides a hydraulic test system for testing a VCU device, which detects the motion performance of the VCU under the working pressure so as to determine whether the VCU device is qualified. It includes the VCU device to be detected, an oil tank, an oil supply pipeline, an oil return pipeline, and a test bench action execution component; a cylinder body is fixedly arranged above the D port of the VCU device, a piston rod is arranged inside the cylinder body, a rack is convexly arranged above the piston rod behind the cylinder body, the rack is meshed and connected with a gear, and an encoder is externally connected to the gear; the oil supply pipeline includes two groups of parallel pump valves, first check valves are respectively arranged at the outlet ends of the two groups of pump valves, the outlet end of the pump valve is connected to the first check valve and then connected to a sequence cartridge valve with a unloading function, the output end of the sequence cartridge valve is connected to the input main pipeline, the input main pipeline is sequentially provided with a second check valve, a throttle valve, and a first pressure sensor and then accesses the A port of the VCU device, and it further includes a pilot valve.

Description

Technical Field

[0001] The present invention relates to the technical field of VCU device testing, and specifically to a hydraulic testing system for testing VCU devices. Background Art

[0002] The VCU is an important part of the diesel engine system. In the prior art, the structure of the VCU is shown in Figure 1 , after the reversing valve 6 is energized, the high-pressure oil of 20 mpa at port A of the valve body 4 passes through the filter assembly 5 and the reversing valve 6 and enters the control port H of the spool 7. The spool 3 moves upward against the spring force of the spring 2, so that port B (oil return port) is cut off from port C, and port C is connected to port A. The high-pressure oil enters the bottom of the piston 8, pushing the piston 8 upward, and the exhaust valve is pushed to act by the hydraulic oil supplemented from the check valve 10; after the reversing valve 6 is de-energized, the control port H of the spool 7 is connected to the fuel tank through the reversing valve 6. Under the action of the spring 2, the spool 3 moves downward, port A is cut off from port C, and port B (oil return port) is connected to port C. The piston 8 and the exhaust valve are reset at the same time; port G supplies oil to another ICU component of the diesel engine, and port F is the pressure detection port; since the valve housing is relatively complex and there are many holes to be machined, equipment testing is required before leaving the factory. For the existing testing structure, different pipeline wirings are required for detection respectively, and the detection efficiency is low. Therefore, there is an urgent need to develop a testing system for VCU devices, so that rapid testing operations can be carried out without complex pipeline repeated assembly. Summary of the Invention

[0003] In view of the above problems, the present invention provides a hydraulic testing system for testing VCU devices, which detects the motion performance of the VCU under the working pressure, thereby determining whether the VCU device is qualified, and its detection ensures the safety of components, the reliability of test actions, and the intuitiveness of the test.

[0004] A hydraulic testing system for testing VCU devices, the technical solution thereof is as follows. It includes the VCU device to be detected, and it further includes:

[0005] A fuel tank;

[0006] An oil supply pipeline,

[0007] An oil return pipeline;

[0008] A test bench action execution component;

[0009] An oil cylinder body is fixedly arranged on the upper part of port D of the VCU device. A piston rod is arranged inside the oil cylinder body. A rack is arranged on the upper part of the piston rod protruding from the oil cylinder body. The rack is meshed and connected with a gear, and the gear is externally connected with an encoder;

[0010] The fuel supply pipeline includes two groups of parallel pump valves. Check valves are respectively arranged at the outlet ends of the two groups of pump valves. After the outlet end of the pump valve is connected to the check valve, it is connected to a sequence cartridge valve with a unloading function. The output end of the sequence cartridge valve is connected to the input main pipeline. The input main pipeline is successively provided with a second check valve, a throttle valve, and a first pressure sensor and then accesses port A of the VCU device. It further includes a pilot valve. A direct flow relief valve group formed by several direct flow relief valves is connected in series in the pilot circuit of the pilot valve. Each direct flow relief valve is connected with a corresponding solenoid valve. The input end of the pilot valve communicates with the fuel tank, and the output end of the pilot valve is connected to the input main pipeline;

[0011] After the outlet end of the pump valve is connected to the check valve, it is also connected with a bypass pipeline. The bypass pipeline is connected to the check valve end of the VCU device through a first pressure reducing pipeline. A two-way cartridge valve, a pressure reducing valve, and a second pressure sensor are arranged on the first pressure reducing pipeline;

[0012] Port B of the VCU device accesses the fuel tank through an oil return pipeline. Port H of the VCU device is connected to a reversing valve and then accesses the oil return pipeline;

[0013] A second pressure reducing pipeline is also connected in parallel to the bypass pipeline. One end of the second pressure reducing pipeline is connected to the upper cavity corresponding to the piston rod. The upper cavity of the piston rod accesses the fuel tank through a back pressure valve.

[0014] Its further features are as follows:

[0015] A third pressure reducing pipeline is also bypassed on the first pressure reducing pipeline. The third pressure reducing pipeline is connected to the oil return pipeline;

[0016] The cross-sectional area of the lower cavity of the piston rod is equal to the cross-sectional area of the upper cavity of the piston. Through the relevant parameters of the encoder and the gear, the linear motion of the piston can be accurately simulated;

[0017] The gear is arranged on an adjusting bracket. The bottom of the adjusting bracket is fixedly arranged on the upper surface of the oil cylinder body. By adjusting the position of the adjusting bracket, the side clearance between the gear and the rack can be eliminated, so as to accurately convert the linear motion into forward and reverse rotation.

[0018] After adopting the structure of the present invention, the test bench action execution component is set at port D of the VCU device as an exhaust valve and becomes an execution element to detect the action performance of the VCU. The oil supply pipeline is connected to port A of the VCU device, and the pressure is adjusted through the pilot pipeline. Different solenoid valves are opened and closed, and are connected in series in the pilot circuit of the pilot valve in different combinations, so that there are several set pressures, enabling the piston to decelerate when it runs close to the limit position and slowly reduce the pressure to avoid damaging the valve body. It enables the entire detection to detect the movement performance of the VCU under the working pressure, and the test has safety, the test action has reliability, and the test image is observable. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a sectional view structure diagram of an existing VCU device;

[0020] Figure 2 is a schematic structural diagram of the assembly of the present invention and the VCU device;

[0021] Figure 3 is a schematic assembly diagram of the VCU device and the test bench action execution component. DETAILED DESCRIPTION OF THE INVENTION

[0022] A hydraulic test system for testing a VCU device, the technical solution thereof is as follows. It includes a VCU device 100 to be detected. The VCU device 100 includes a cover plate 1, a spring 2, a valve core 3, a valve body 4, a filter assembly 5, a reversing valve 6, a valve core 7, a piston 8, an end cover 9, a check valve 10, port A (oil inlet), port B (oil return), port C, port D, port E, port F (detection pressure port), port H (control port of the valve core 3), port G; it also includes an oil tank 20, an oil supply pipeline 30, an oil return pipeline 40, and a test bench action execution component 50;

[0023] The test bench action execution component 50 includes an oil cylinder body 51, a piston rod 52, a rack 53, a gear 54, and an encoder 55;

[0024] An oil cylinder body 51 is fixedly arranged on the upper part of port D of the VCU device 100. A piston rod 52 is arranged inside the oil cylinder body 51. A rack 53 is arranged on the upper part of the piston rod 52 protruding from the oil cylinder body. The rack 53 is meshed and connected to a gear 54, and an encoder 55 is externally connected to the gear 54;

[0025] The fuel supply pipeline 30 includes two groups of parallel pump valves 31. Check valves 32 are respectively arranged at the outlet ends of the two groups of pump valves 31. After the outlet end of the pump valve 31 is connected to the check valve 32, it is connected to a sequence cartridge valve 33 with a unloading function. The output end of the sequence cartridge valve 33 is connected to the input main pipeline 60. The input main pipeline 60 is successively provided with a second check valve 61, a throttle valve 62, and a first pressure sensor 63 and then accesses port A of the VCU device 100. It also includes a pilot valve 34. A series of direct-flow overflow valves 35 are connected in series in the pilot circuit of the pilot valve 34. Each direct-flow overflow valve 35 is connected to a corresponding solenoid valve 36. The input end of the pilot valve 34 communicates with the fuel tank 20, and the output end of the pilot valve 34 is connected to the input main pipeline 60;

[0026] After the outlet end of the pump valve 31 communicates with the check valve 32, it is also connected to a bypass pipeline 70. The bypass pipeline 70 is connected to the check valve 10 end of the VCU device 100 through a first pressure reducing pipeline 80. A two-way cartridge valve 81, a pressure reducing valve 82, and a second pressure sensor 83 are arranged on the first pressure reducing pipeline 80;

[0027] After the outlet end of the pump valve 31 communicates with the check valve 32, it is also connected to the fuel tank 20 through a safety valve 120 to ensure the safety of the oil circuit in case of an emergency;

[0028] Port B of the VCU device 100 accesses the fuel tank 20 through an oil return pipeline 40. Port H of the VCU device 100 is connected to a reversing valve 6 and then accesses the oil return pipeline 40;

[0029] A second pressure reducing pipeline 90 is also connected in parallel to the bypass pipeline 70. One end of the second pressure reducing pipeline 90 is connected to the upper chamber 56 corresponding to the piston rod 52. The upper chamber of the piston rod 52 accesses the fuel tank 20 through a back pressure valve 91; The second pressure reducing pipeline 90 includes a second pressure reducing valve 92 and a third pressure sensor 93;

[0030] A third pressure reducing pipeline 110 is also bypassed to the first pressure reducing pipeline 80. The third pressure reducing pipeline 110 is connected to the oil return pipeline 20. A two-way cartridge valve 111, a third pressure reducing valve 112, and a fourth pressure sensor 113 are arranged on the third pressure reducing pipeline 110;

[0031] The cross-sectional area of the lower chamber 57 of the piston rod 52 is equal to the cross-sectional area of the upper chamber of the piston 8. Through the relevant parameters of the encoder 55 and the gear 54, the linear motion of the piston 8 can be accurately simulated;

[0032] The gear 54 is arranged on the adjusting bracket 58. The bottom of the adjusting bracket 58 is fixedly arranged on the upper surface of the oil cylinder body 51. By adjusting the position of the adjusting bracket 58, the side clearance between the gear 54 and the rack 53 can be eliminated, so as to accurately convert the linear motion into a forward and reverse rotation.

[0033] The working process is as follows: Figure 3 The rated pressure of the motor pump unit of the middle pump valve 31 is 25 mpa. There are two groups of pumps in the system. If the flow rate of one group of pumps is insufficient during the test, both groups are turned on. The function of the check valve 32 is to protect the other group of pumps. The main function of the sequence cartridge valve 33 with unloading function is to ensure that there is at least 2.5 mpa of pressure in the system to maintain the normal operation of the system. The set pressure of the safety valve 120 is 23 mpa to play a safety protection role. Through different energizing and de-energizing combinations of the solenoid valve 36, the direct-flow overflow valves 35 with different set pressures are connected in series in the pilot circuit of the pilot valve 34 in different combinations. In a specific embodiment, there are three direct-flow overflow valves 35, which enable up to eight set pressures (including pressure relief): This design mainly considers 1. decelerating the piston when it runs close to the limit position; 2. slowly reducing the pressure to avoid damage to the valve body. The function of the second check valve 61 is to enable the piston to stay at a certain position and maintain it. The function of the throttle valve 62 is to adjust the rising speed of the piston. The pressure sensor 63 is used to detect the pressure at port A of the valve body.

[0034] Test preparation stage: After the equipment is assembled, the pilot overflow valve formed by the combination of the direct-flow overflow valve 35 and the pilot valve 34 unloads, and the sequence valve 4 does not unload. The two-way cartridge valves on the first decompression pipeline 80 and the third decompression pipeline 110 are closed, and the reversing valve 6 is de-energized. At this time, the system only supplies oil to the upper chamber 56 of the piston rod 52. When the pressure sensor detects that the pressure reaches 1.5 mpa set by the second pressure reducing valve 92 on the second decompression pipeline 90, the two-way cartridge valve 81 on the first decompression pipeline 80 is turned on. At this time, the system supplies oil to the upper chamber of the piston 8 and the lower chamber 57 of the piston rod 52. When the pressure sensor 83 detects that the pressure reaches 1 mpa set by the pressure reducing valve 82, the two-way cartridge valve 111 is turned on. At this time, the system supplies oil to port B of the valve body and forms a back pressure through the throttle valve 41 to ensure that the piston 8 can descend smoothly. When the fourth pressure sensor 113 detects that the pressure is 0.5 mpa set by the third pressure reducing valve 112, the test preparation work ends. The above actions can ensure that each component operates according to the designed actions. Otherwise, misoperations may occur, affecting the test.

[0035] Piston rising test: By making the three solenoid valves 36 in a certain energizing and de-energizing state, the pressure set by the pilot valve 34 is the highest value among the eight pressures, and at the same time, the reversing valve 6 is energized. Figure 1The middle spool 3 moves upward against the spring force of the spring 2, so that the port B (oil return port) is cut off from the port C, the port C is connected to the port A, and the high-pressure oil enters the bottom of the piston 8, pushing the piston 8 upward. The hydraulic oil supplemented from the check valve 10 is used to push the piston rod 52 to move. The upper chamber 56 of the piston rod 52 returns oil through the back pressure valve 91. The set pressure of the back pressure valve 91 is 20 mpa. The test can be carried out under the rated pressure through the back pressure valve 91. When the encoder 55 calculates that the piston 8 is about to reach the end of its fast movement, the solenoid valve 36 is in the corresponding state to reduce the set pressure of the pilot valve 34, so as to control the piston 8 to decelerate and stop during its upward movement;

[0036] Piston stop stage: In this stage, the reversing valve 6 is energized, and the solenoid valve 36 is in the corresponding state to continuously reduce the set pressure of the pilot valve 34 (until the lowest pressure in the pressure relief state), so as to slowly reduce the pressure and avoid damaging the valve body;

[0037] Piston descending stage: In this stage, the reversing valve 6 is de-energized, and the pilot valve 34 is in the unloading state. Due to the pressure in the upper chamber 56 of the piston rod 52 and the back pressure of the port B, the piston 8 descends smoothly. When the encoder 55 detects that the piston 8 is about to reach the end of its fast descent, the two-way cartridge valve 42 is cut off, so as to reduce the descending speed of the piston 8 and avoid impact.

[0038] The working principle is as follows. The action execution component of the test bench is set at the port D of the VCU device as the exhaust valve and becomes the execution element to detect the action performance of the VCU. The oil supply pipeline is connected to the port A of the VCU device, the pressure is set through the pilot pipeline, and different solenoid valves are opened and closed through the direct-flow overflow valve and connected in series in the pilot circuit of the pilot valve in different combinations, so there are several set pressures, enabling the piston to decelerate when it runs close to the limit position and slowly reducing the pressure to avoid damaging the valve body. It enables the entire detection to detect the movement performance of the VCU under the working pressure, and the test has safety, the test action has reliability, and the test image is good.

[0039] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claimed rights.

[0040] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment contains only one independent technical solution. This narrative style of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A hydraulic test system for testing a VCU device, which includes the VCU device to be tested, characterized in that, it further includes: an oil tank; a fuel supply pipeline, a return oil pipeline; a test bench action execution component; An oil cylinder body is fixedly arranged on the upper part of the D port of the VCU device. A piston rod is arranged inside the oil cylinder body. A rack is arranged on the upper part of the piston rod protruding above the oil cylinder body. The rack is meshed and connected with a gear, and an encoder is externally connected to the gear; The fuel supply pipeline includes two groups of parallel pump valves. First check valves are respectively arranged at the outlet ends of the two groups of pump valves. After the outlet end of the pump valve is connected to the first check valve, it is connected to a sequence cartridge valve with a unloading function. The output end of the sequence cartridge valve is connected to the input main pipeline. The input main pipeline is successively provided with a second check valve, a throttle valve, and a first pressure sensor and then accesses the A port of the VCU device. It also includes a pilot valve. A direct overflow valve group formed by several direct overflow valves is connected in series in the pilot circuit of the pilot valve. Each direct overflow valve is connected with a corresponding solenoid valve. The input end of the pilot valve is communicated with the oil tank, and the output end of the pilot valve is connected to the input main pipeline; After the outlet end of the pump valve is communicated with the first check valve, it is also connected with a bypass pipeline. The bypass pipeline is connected to the check valve end of the VCU device through a first decompression pipeline. A two-way cartridge valve, a pressure reducing valve, and a second pressure sensor are arranged on the first decompression pipeline; The B port of the VCU device accesses the oil tank through the return oil pipeline. The H port of the VCU device is connected to a reversing valve and then accesses the return oil pipeline; A second decompression pipeline is also connected in parallel to the bypass pipeline. One end of the second decompression pipeline is connected to the upper chamber corresponding to the piston rod. The upper chamber of the piston rod accesses the oil tank through a back pressure valve; A third decompression pipeline is also bypassed from the first decompression pipeline. The third decompression pipeline is connected to the return oil pipeline; The cross-sectional area of the lower chamber of the piston rod is equal to the cross-sectional area of the upper chamber of the piston.

2. A hydraulic test system for testing a VCU device according to claim 1, characterized in that: The gear is arranged on an adjusting bracket, and the bottom of the adjusting bracket is fixedly arranged on the upper surface of the oil cylinder body.

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