Anti-vibration backflow one-way valve

Abstract

The one-way valve comprises a valve sleeve (1), an annular groove (2) is formed in an inner hole of the valve sleeve (1), a valve element (3) corresponding to the axial position of the annular groove (2) is arranged in the valve sleeve (1), a flow channel is formed in the valve element (3) and communicated with the annular groove (2) and the rear side space of the valve element (3), a spring (4) connected with the valve sleeve (1) is arranged on the rear side of the valve element (3), and a valve seat (5) is arranged on the front side of the valve element (3). A first through hole (6) is formed in the valve seat (5) in the axial direction, the front side of the valve element (3) makes contact with the conical surface of the valve seat (5) to form a first sealing part (7), an annular second sealing part (8) is formed between the valve element (3) and the valve sleeve (1) and located on the front side of the annular groove (2), and the axial length of the second sealing part (8) is larger than 0.2 mm. The hydraulic cylinder has the advantages of being low in opening pressure and capable of effectively preventing oil liquid from flowing back in a vibration environment.

Description

Technical Field

[0001] The invention belongs to the field of one-way valves, and in particular relates to a one-way valve for preventing vibration backflow used in a hydraulic system. Background Art

[0002] The one-way valve is a common and extremely important hydraulic component in hydraulic systems. Its main function is to make the fluid flow in one direction only and not backflow. At the same time, it is required to have very small resistance in the flow direction, good sealing in the reverse direction, and sensitive movement without vibration.

[0003] At present, low opening pressure (such as opening pressure ≤ 0.05MPa) and oil backflow when working in a vibrating environment are a difficulty in the design of a one-way valve. This is mainly because under the condition of low opening pressure, the elastic force value of the spring installed in the one-way valve needs to be designed to be extremely small to meet the condition of low-pressure opening of the one-way valve; at the same time, according to the working environment of the one-way valve, such as sometimes being installed on the engine body, the one-way valve will follow the engine vibration, and the vibration will cause the spring to deform or twist slightly, resulting in the failure of the spring preload. At the same time, the valve core of the one-way valve will temporarily detach from the valve seat along the axial direction during vibration, the seal will open, the seal will fail, and the oil will flow back. The backflow of oil through the one-way valve will increase the engine fuel consumption, increase the noise, and increase the oil pressure in some internal cavities of the system. In severe cases, it will affect the performance of the engine or hydraulic system, or cause the engine or hydraulic system to fail.

[0004] Therefore, a one-way valve is needed which has a low opening pressure and can effectively prevent oil backflow in a vibration environment. Summary of the invention

[0005] The object of the present invention is to provide a one-way valve for preventing backflow due to vibration. The present invention has the advantages of low opening pressure and can effectively prevent oil backflow in a vibration environment.

[0006] The technical solution of the present invention is as follows: a one-way valve for preventing vibration backflow comprises a valve sleeve, an annular groove is provided at the inner hole of the valve sleeve, a valve core corresponding to the axial position of the annular groove is provided in the valve sleeve, a flow channel is provided on the valve core, the flow channel connects the annular groove and the rear space of the valve core, a spring connected to the valve sleeve is provided on the rear side of the valve core, a valve seat is provided on the front side of the valve core, a first through hole is provided in the axial direction of the valve seat, the front side of the valve core contacts with the conical surface of the valve seat to form a first sealing portion, and an annular second sealing portion is formed between the valve core and the valve sleeve, the second sealing portion is located on the front side of the annular groove, and the axial length of the second sealing portion is more than 0.2 mm.

[0007] In the aforementioned one-way valve for preventing vibration backflow, the length of the second sealing portion is 0.5-1 mm, and the matching clearance between the valve core and the valve sleeve at the second sealing portion is 0.007-0.01 mm.

[0008] In the aforementioned one-way valve for preventing vibration backflow, a bushing is provided on the rear side of the spring, the spring is connected to the valve sleeve via the bushing, and a second through hole is provided in the axial direction of the bushing.

[0009] In the aforementioned one-way valve for preventing vibration backflow, a pipe joint is provided on the front side of the valve sleeve, and a sealing ring is provided between the pipe joint and the valve sleeve.

[0010] In the aforementioned one-way valve for preventing vibration backflow, the valve seat is fixed between the valve sleeve and the pipe joint, and a filter screen covering the first through hole is provided on the front side of the valve seat.

[0011] In the aforementioned one-way valve for preventing vibration backflow, the filter screen is conical in shape, and the middle part of the filter screen faces the pipe joint.

[0012] In the aforementioned one-way valve for preventing vibration backflow, a blind hole is provided on the rear end surface of the valve core, and a plurality of oil holes communicating with the annular groove are provided on the side wall of the blind hole. The blind hole and the plurality of oil holes constitute an oil passage.

[0013] Compared with the prior art, the present invention has two sealing parts in the axial direction. When the one-way valve is operated in a vibrating working environment, in the case of using a low elastic value spring, even if the spring may be slightly deformed or twisted and the valve core has a slight axial movement so that one of the sealing parts is temporarily opened, the other sealing part will not be opened, and the dynamic sealing state will be maintained, so that the oil will not flow back. Therefore, the present invention has the advantages of low opening pressure and can effectively prevent oil backflow in a vibrating environment.

[0014] In addition, by arranging a filter on the front side of the valve core, impurities in the oil are intercepted to prevent the sealing part from being damaged by the impurities, thereby extending the service life of the one-way valve and improving the safety of the engine or hydraulic system. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a front view schematic diagram of the present invention.

[0016] The markings in the accompanying drawings are: 1-valve sleeve, 2-ring groove, 3-valve core, 4-spring, 5-valve seat, 6-first through hole, 7-first sealing part, 8-second sealing part, 9-bushing, 10-second through hole, 11-pipe joint, 12-sealing ring, 13-filter, 14-blind hole, 15-oil hole. DETAILED DESCRIPTION

[0017] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the present invention.

[0018] Example: A one-way valve to prevent vibration backflow, such as Figure 1 As shown, in Figure 1In the figure, the right side is the front side, which includes a valve sleeve 1. An annular groove 2 is provided at the inner hole of the valve sleeve 1. A valve core 3 corresponding to the axial position of the annular groove 2 is provided in the valve sleeve 1. A blind hole 14 is provided on the rear end surface of the valve core 3. Four oil holes 15 that are evenly distributed in the circumference and connected to the annular groove 2 are provided on the side wall of the blind hole 14. The blind hole 14 and the four oil holes 15 form an oil channel, which connects the annular groove 2 with the rear port of the valve sleeve 1.

[0019] A bushing 9 connected to the valve sleeve 1 is provided at the rear side of the valve core 3 , and a second through hole 10 is axially provided in the bushing 9 . A spiral spring 4 is provided between the bushing 9 and the valve core 3 , and the front end of the spring 4 enters into the blind hole 14 .

[0020] A valve seat 5 is provided at the front side of the valve core 3 , and a first through hole 6 is provided in the axial direction of the valve seat 5 . The front side of the valve core 3 contacts the conical surface of the valve seat 5 , and a first sealing portion 7 is formed at the contact position.

[0021] An annular second sealing portion 8 is formed between the valve core 3 and the valve sleeve 1. The second sealing portion 8 is located at the front side of the annular groove 2, and the axial length of the second sealing portion 8 is 0.5-1mm. By grinding the corresponding positions of the valve sleeve 1 and the valve core 3, the matching clearance between the valve core 3 and the valve sleeve 1 at the second sealing portion 8 is 0.007-0.01mm, forming a dynamic seal. The matching relationship between the valve core 3 and the valve sleeve 1 at other positions can adopt a larger clearance, so as to reduce the movement resistance of the valve core 3 and improve the response speed of the one-way valve.

[0022] The front side of the valve sleeve 1 is provided with a pipe joint 11, an O-shaped sealing ring 12 is provided between the pipe joint 11 and the valve sleeve 1, the valve seat 5 is fixed between the valve sleeve 1 and the pipe joint 11, and the front side of the valve seat 5 is provided with a filter screen 13 covering the first through hole 6, the filter screen 13 is conical, which increases the filtering area of ​​the filter screen 13, helps to keep the oil unobstructed, and reduces the flow resistance of the oil, and the middle part of the filter screen 13 faces the pipe joint 11. In the comparative test, it was found that the effect of the middle part of the filter screen 13 facing the pipe joint 11 is better than that of the middle part of the filter screen 13 facing the valve seat 5.

[0023] Working principle: Low-pressure oil enters the one-way valve from the pipe joint 11, and enters the valve seat 5 after filtering impurities through the filter screen 13. The oil acts on the valve core 3 to move the valve core 3 backward. The first sealing part 7 is opened first until the valve core 3 moves a distance that exceeds the axial length of the second sealing part 8, that is, 0.5-1mm. Then, the second sealing part 8 is also opened. The oil flows from the outside of the front end of the valve core 3, enters the annular groove 2, and then enters the blind hole 14 through the oil hole 15, and finally flows out from the rear end of the valve sleeve 1.

[0024] When the one-way valve is operating in a vibrating working environment, even if the spring 4 may be slightly deformed or twisted and the valve core 3 may have a slight axial movement so that the first sealing part 7 is briefly opened, due to the certain axial length of the second sealing part 8, the second sealing part 8 will not open and the oil will not flow back.

[0025] The spring 4 has a low elastic force value so that the opening pressure of the one-way valve is ≤0.05MPa. For example, when the opening pressure of the one-way valve is 0.05MPa and the oil pressure entering the front end is ≥0.05MPa, the spring 4 should be able to be compressed and deformed to a certain extent to open the one-way valve.

[0026] In the description of the embodiments, it should be understood that the terms "up", "down", "front", "back", "left", "right", etc., indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation.

Claims

1. A one-way valve to prevent vibration backflow, characterized by: The invention comprises a valve sleeve (1), wherein an annular groove (2) is provided at the inner hole of the valve sleeve (1), a valve core (3) corresponding to the axial position of the annular groove (2) is provided in the valve sleeve (1), a flow channel is provided on the valve core (3), the flow channel connects the annular groove (2) and the rear space of the valve core (3), a spring (4) connected to the valve sleeve (1) is provided on the rear side of the valve core (3), a valve seat (5) is provided on the front side of the valve core (3), a first through hole (6) is provided on the valve seat (5) in the axial direction, the front side of the valve core (3) contacts the conical surface of the valve seat (5) to form a first sealing portion (7), and an annular second sealing portion (8) is formed between the valve core (3) and the valve sleeve (1), the second sealing portion (8) is located on the front side of the annular groove (2), and the axial length of the second sealing portion (8) is more than 0.2 mm.

2. The one-way valve for preventing vibration backflow according to claim 1, characterized in that: The length of the second sealing portion (8) is 0.5-1 mm, and the matching clearance between the valve core (3) and the valve sleeve (1) at the second sealing portion (8) is 0.007-0.01 mm.

3. The one-way valve for preventing vibration backflow according to claim 1, characterized in that: A bushing (9) is provided on the rear side of the spring (4), the spring (4) is connected to the valve sleeve (1) via the bushing (9), and a second through hole (10) is provided in the axial direction of the bushing (9).

4. The one-way valve for preventing vibration backflow according to claim 1, characterized in that: A pipe joint (11) is provided on the front side of the valve sleeve (1), and a sealing ring (12) is provided between the pipe joint (11) and the valve sleeve (1).

5. The one-way valve for preventing vibration backflow according to claim 4, characterized in that: The valve seat (5) is fixed between the valve sleeve (1) and the pipe joint (11), and a filter screen (13) covering the first through hole (6) is provided on the front side of the valve seat (5).

6. The one-way valve for preventing vibration backflow according to claim 5, characterized in that: The filter screen (13) is conical, and the middle part of the filter screen (13) faces the pipe joint (11).

7. The one-way valve for preventing vibration backflow according to claim 1, characterized in that: A blind hole (14) is provided on the rear end surface of the valve core (3), a plurality of oil holes (15) communicating with the annular groove are provided on the side wall of the blind hole (14), and the blind hole (14) and the plurality of oil holes (15) form an oil passage.

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