Built-in one-way valve and hydraulic application platform thereof

Abstract

The built-in one-way valve comprises a cartridge valve body, the cartridge valve body comprises a first port, a second port, a third port and a fourth port which are sequentially arranged from bottom to top, a sliding valve sleeve is arranged at the position of the first port in the cartridge valve body, and the built-in one-way valve is arranged at the position of the first port in the cartridge valve body. Compared with the prior art, the check valve has the advantages that the check valve is compact in structure, and an existing valve body does not need to be changed; and 2, the cost is lower, the one-way valve is smaller in structure and is in a built-in form, an additional sealing piece and an independent oil way are not needed for connection, the production cost of the one-way valve is lower, the use cost is lower, and the change cost is lower after a problem occurs. And 3, the risk of external leakage is avoided, and compared with the structure of independently adding an integral one-way valve, the risk of oil leakage does not exist by adopting a built-in mode.

Description

Technical Field

[0001] This utility model relates to the field of cartridge valve technology, specifically to a built-in check valve and its hydraulic application platform. Background Technology

[0002] Cartridge valves are widely used in various engineering machines due to their high compactness and miniaturization. Cartridge solenoid directional valves are used in various key mechanisms thanks to their structural and performance advantages. Since their structural cavities are universal and standard, their oil ports are arranged according to the standard, namely, port 1, port 2, port 3, port 4, etc. from bottom to top.

[0003] Due to structural limitations, port 1 is located on the axial direction of the valve core, and the magnetic tube that generates electromagnetic force to drive the valve core is also on its axial direction. Most designs will allow oil to return through port 1 to avoid the influence of pressure on port 1, and will also balance the force on the valve core inside to prevent the valve core from being affected by the pressure on the end face of port 1. However, some valve cores are designed to increase the damping ratio and avoid vibration, and will have a damping design added inside the magnetic tube opposite port 1 and between port 1. This will cause the force on the valve core to be unbalanced under some special working conditions. When affected by the pressure of port 1, the valve core will switch, which may cause malfunctions under special working conditions.

[0004] for example Figure 3 The hydraulic schematic shown is typical of most boom lifts. The boxed section represents a long pipeline connecting the upper and lower platforms. For high-reach boom lifts, this connecting pipeline can exceed 50 meters. Due to the limitations of the boom structure, the pipe diameter cannot be very large. Based on the formula for friction loss, the pressure loss in this return pipeline, especially in cold weather due to increased oil viscosity, leads to a high back pressure at port T of the platform valve. This back pressure acts on port 1 of directional valve 1 and directional valve 2, causing a momentary pressure drop at port 1. The back pressure of the return oil at the port and the inability of the internal damping to balance the pressure in time can cause the valve core to malfunction during switching. This problem tends to occur more frequently when the temperature is low, but it does not occur when the oil temperature is high. Furthermore, the phenomenon varies between different brands of cartridge valve cores. Only some brands of valve cores do not have this problem due to differences in their internal structure design. Of course, some models have considered this problem in the initial design and added a check valve to port 1 to solve the problem. However, most models did not consider this design because the malfunction only occurs in winter. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a built-in one-way valve and its application platform that can be placed between the valve core and the cavity, in view of the shortcomings mentioned in the background art.

[0006] To solve the above technical problems, the technical solution provided by this utility model is as follows: a built-in one-way valve, including a cartridge valve body, wherein the cartridge valve body includes port 1, port 2, port 3 and port 4 arranged sequentially from bottom to top, a slide valve sleeve is provided in the cartridge valve body at port 1, and a built-in one-way valve is provided in the cartridge valve body at port 1.

[0007] The built-in one-way valve includes a one-way valve sleeve, a one-way valve core, a one-way valve spring, and a retaining ring.

[0008] Furthermore, a first conical seal is formed between the one-way valve sleeve and the one-way valve core.

[0009] Furthermore, the one-way valve sleeve and the slide valve sleeve are sealed by a second conical seal formed by the inclined surface of the one-way valve.

[0010] A hydraulic application platform employing a cartridge valve with a built-in check valve is disclosed. The hydraulic application platform includes a return valve, a proportional valve, a directional valve, a boom function valve, a power source, and a load-sensing system. The power source includes a hydraulic pump, a boom function valve, and a platform control valve. A hydraulic oil tank is connected to the end of the hydraulic pump. The load-sensing system consists of a boom function valve and a three-way flow valve. A pipeline structure is provided between the boom function valve and the platform control valve. The platform control valve is equipped with a first cartridge valve and a second cartridge valve. The built-in check valve is located at port 1 of the first and second cartridge valves.

[0011] The advantages of this utility model compared with the prior art are: 1. It has a compact structure and does not require changes to the existing valve body;

[0012] 2. Lower cost: Due to its smaller size and built-in design, it does not require additional seals or separate oil lines for connection. The production cost of the check valve itself is lower, the operating cost is also lower, and the cost of replacement when problems occur is also lower.

[0013] 3. No risk of external leakage: Compared to adding a separate integral check valve, the built-in design eliminates the risk of oil leakage. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a built-in check valve;

[0015] Figure 2 This is a schematic diagram of the specific structure of a built-in check valve;

[0016] Figure 3 This is a schematic diagram of a hydraulic application platform that uses a valve core-embedded check valve.

[0017] As shown in the figure: 1. Hydraulic oil tank; 2. Return valve; 3. Hydraulic pump; 4. First boom function valve; 5. Three-way flow valve; 6. Proportional valve; 7. Directional valve; 8. Second boom function valve; 9. Piping structure; 10. Platform control valve; 11. First cartridge valve; 12. Second cartridge valve; 13. Cartridge valve body; 14. Check valve sleeve; 15. Check valve core; 16. Check valve spring; 17. Snap ring; 18. Spool valve sleeve; 19. First conical seal; 20. Second conical seal; 21. Port 1; 22. Port 2; 23. Port 3; 24. Port 4. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings.

[0019] Combined with appendix Figure 1-3 A built-in one-way valve includes a cartridge valve body 13, wherein the cartridge valve body 13 includes port 1 21, port 22, port 3 23 and port 4 24 arranged sequentially from bottom to top, a slide valve sleeve 18 is provided in the cartridge valve body 13 at the position of port 1 21, and a built-in one-way valve is provided in the cartridge valve body 13 at the position of port 1 21;

[0020] The built-in one-way valve includes a one-way valve sleeve 14, a one-way valve core 15, a one-way valve spring 16, and a retaining ring 17.

[0021] A first conical seal 19 is formed between the one-way valve sleeve 14 and the one-way valve core 15.

[0022] The one-way valve sleeve 14 and the slide valve sleeve 18 form a second conical seal 20 through the inclined surface of the one-way valve.

[0023] When the system is working, the return oil after the slide valve reverses comes out from port 1, such as Figure 2 As shown by the middle arrow, when the check valve core 15 is pushed open, the check valve spring 16 is compressed, and the valve core returns oil. Similarly, there is a gap between the check valve sleeve 14 and the cartridge valve body 13, and also a gap between the sleeve 14 and the bottom of the cartridge valve body 13. Therefore, the check valve sleeve 14 will also move downwards, and the sealing surface that originally fits between the check valve sleeve 14 and the spool valve sleeve 18 will also separate (this design is to match different machining depths and prevent dimensional deviations from causing the check valve sleeve 14 to be pushed to the bottom). At the same time, there is a gap between the outer diameter of the check valve sleeve 14 and the inner diameter of the hole in the cartridge valve body 13, allowing the check valve sleeve 14 to slide inside. When the fault problem mentioned in the background information occurs, with a high return oil back pressure at port 1, pressurized oil comes from the return oil line, as shown above. Figure 2As shown by the red arrow, since the check valve has a return spring, the check valve port is already closed after the oil is discharged from port 1. At this time, only the check valve sleeve 14 may be at the bottom under the action of gravity or the influence of the check valve back pressure. When this pressure comes, it will act on the entire built-in check valve, causing it to move upward. When the conical surface of the check valve sleeve 14 and the slide valve sleeve 18 form a second conical seal 20 after fitting, all the pressure oil is isolated from the outside by the check valve, avoiding the malfunction problem mentioned in the background information.

[0024] like Figure 3 The diagram shown is a simplified hydraulic principle diagram of an aerial work platform, which consists of three parts: a power source hydraulic pump 3, a first boom function valve 4, and a platform control valve 10. The hydraulic pump 3 is connected to a hydraulic oil tank 1, which is equipped with a return valve 2. The first boom function valve 4 is connected to a three-way flow valve 5 to form a load-sensitive system, which is used to control the movement of the entire vehicle. The first boom function valve 4 controls the movement below the boom, such as turntable rotation, boom luffing, boom extension and retraction, and vehicle steering. The control principles are basically similar, with the speed controlled by a proportional valve 6 and the direction valve 7 controlling the direction of movement.

[0025] In addition to the movements below the boom, the boom head also controls three other movements: platform leveling, boom luffing, and platform oscillation. The control principle is that the second boom function valve 8 acts as the enable valve, providing the oil source for platform movements and controlling the speed of those movements. Connecting the platform control valve 10 and the first boom function valve 4 is a pipeline structure 9 several tens of meters long. According to the friction loss formula, due to structural limitations, the pipeline diameter cannot be too large, and the pipeline length is very long. Therefore, there will be a high back pressure in the return oil pipeline at port T of the platform control valve, which will also act on port 21 of the two first cartridge valves 11 and the second cartridge valve 12 above the platform control valve. When a certain movement of the platform generates oil return, the oil begins to flow and is affected by friction loss, resulting in high pressure at the platform valve T port. This pressure acts on port 1 (21) of other platform movement control valves, causing the valve core to switch direction and resulting in malfunction. Therefore, adding a built-in check valve can avoid this problem. However, not all valve cores will exhibit this phenomenon, so a check valve is not directly designed there in the initial principle design. Therefore, when this problem occurs, the simplest solution is to add a built-in check valve inside the cavity, which is lower in cost, can achieve the corresponding effect, and will not cause other impacts.

[0026] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A built-in one-way valve, comprising a cartridge valve body (13), wherein the cartridge valve body (13) comprises port 1 (21), port 2 (22), port 3 (23), and port 4 (24) arranged sequentially from bottom to top, and wherein a spool valve sleeve (18) is provided inside the cartridge valve body (13) at port 1 (21), characterized in that: The cartridge valve body (13) is equipped with a built-in check valve located at port 1 (21); The built-in one-way valve includes a one-way valve sleeve (14), a one-way valve core (15), a one-way valve spring (16), and a retaining ring (17).

2. The built-in check valve according to claim 1, characterized in that: A first conical seal (19) is formed between the one-way valve sleeve (14) and the one-way valve core (15).

3. The built-in check valve according to claim 1, characterized in that: The one-way valve sleeve (14) and the slide valve sleeve (18) form a second conical seal (20) through the inclined surface of the one-way valve.

4. A hydraulic application platform using a built-in check valve according to any one of claims 1-3, the hydraulic application platform comprising a return valve (2), a proportional valve (6), a directional valve (7), a second boom function valve (8), a power source, and a load-sensing system, the power source comprising a hydraulic pump (3), a first boom function valve (4), and a platform control valve (10), the hydraulic pump (3) having a hydraulic oil tank (1) connected to its end, the load-sensing system being composed of the first boom function valve (4) and a three-way flow valve (5), a pipeline structure (9) being provided between the first boom function valve (4) and the platform control valve (10), and the platform control valve (10) having a first cartridge valve (11) and a second cartridge valve (12), characterized in that: The built-in one-way valve is located at port 1 (21) of the first cartridge valve (11) and the second cartridge valve (12).

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