Hydraulically controlled manual release normally open valve

Abstract

The present invention provides a hydraulically controlled manually released normally open valve, belonging to the technical field of hydraulic valves. It solves the problem that the existing manually released normally open valves are prone to numbness of the arm when the arm is used for a long time, and the use effect and practicality are poor. The hydraulically controlled manually released normally open valve includes a valve body, a valve seat, a valve cover and a valve core. The inner center of the valve core has a through-type cavity structure and a through hole. The cavity structure and the through hole are located on the same axis and are interconnected. A reset spring is arranged in the cavity structure. The two ends of the reset spring respectively abut against the step in the cavity structure and the oil outlet in the valve body. At least one hydraulic flow channel is axially opened on the side wall of the valve core. A pilot valve needle is axially arranged inside the valve seat. The end of the pilot valve needle matches the position of the through hole on the valve core and the diameter of the pilot valve needle is larger than the diameter of the through hole. The present invention has the advantages of more reasonable overall structural design, and only a slight thrust is needed to control the flow channel cutoff by applying hydraulic pressure to produce a self-locking effect.

Description

Technical Field

[0001] The invention belongs to the technical field of hydraulic valves and relates to a normally open valve, in particular to a hydraulically controlled manually released normally open valve. Background Art

[0002] The application of release valves in the hydraulic field includes normally open valves and normally closed valves. The principle of the normally closed valve is that it is in the cut-off state during normal use and is turned on by external force, while the principle of the normally open valve is just the opposite. It is in the on state during normal use and is turned off by external force. Currently, the most widely used valve on the market is the normally closed valve, but normally open valves are needed in some special fields, such as hydraulic control on elevators. In an emergency, the hydraulic oil circuit can be interrupted and cut off to prevent safety hazards.

[0003] In the prior art, normally open valves are divided into two types: manual control and electromagnetic control. Electromagnetic control has the following problems: a relatively complex structure, high manufacturing cost, and low reliability. That is, unstable current causes insufficient magnetic field strength or circuit aging fails to generate a magnetic field, etc., which will cause the valve core to be unable to be effectively shut off in an emergency. In the existing manual control, due to the high pressure generated by the hydraulic flow channel, the manual normally open valve needs to be pushed by the palm to shut off the hydraulic pressure. The hand is under a large reverse thrust, and the arm is prone to numbness when in a state of long-term exertion, resulting in poor use effect and practicality. Summary of the invention

[0004] The purpose of the present invention is to address the above-mentioned problems existing in the prior art and to provide a hydraulically controlled manually released normally open valve with a more reasonable overall structural design, which can produce a self-locking effect using hydraulic pressure and control the flow channel cutoff with only a slight thrust.

[0005] ] a control mechanism that the cam is connected with the valve core, and the control mechanism that the cam is connected with the valve body is connected with the control mechanism, and the control mechanism that the cam is connected with the valve body is connected with the control mechanism.

[0006] In this hydraulic control manual release normally open valve, it is in the conducting state under normal circumstances, and the hydraulic oil flows in from the oil inlet and flows out from the oil outlet. When it needs to be cut off, the pilot valve needle is lowered by external pressure to abut against the through hole to form a seal, and the valve core is moved to contact and seal with the oil outlet. At this time, the hydraulic oil enters the cavity above the valve core through the hydraulic flow channel on the side wall of the valve core. The cross-sectional area of ​​the upper end face of the valve core is larger than the cross-sectional area at the oil outlet, and the through hole is blocked and in a sealed state. Therefore, the oil pressure of the hydraulic oil will cause the valve core to produce a self-locking pressure and abut against the oil outlet to form a self-locking seal. When the normally open valve needs to be reopened, it is only necessary to remove the external pressure to retract the pilot valve needle, and the through hole is in the conducting state. The pressure inside the valve body is balanced, and the valve core rises due to the elastic force of the reset spring, and the valve is reopened.

[0007] In the above-mentioned hydraulically controlled manually released normally open valve, the internal radial protrusion of the valve seat forms two sealing grooves, namely a lower sealing groove and an upper sealing groove. An oil seal and an O-ring are clamped in the lower sealing groove. The inner surface of the oil seal is in contact with the pilot valve needle. The outer surface of the oil seal is an arc surface structure and a set of O-rings is arranged outside the oil seal. The bottom of the oil seal is fixed in the lower sealing groove by a pressure ring.

[0008] In the above-mentioned hydraulically controlled manually released normally open valve, a sealing ring is clamped in the upper sealing groove, the sealing ring has a countersunk structure and is provided with an O-ring 2, and the sealing ring and the O-ring 2 are in contact and sealed with the pilot valve needle at the same time.

[0009] In the above-mentioned hydraulically controlled manually released normally open valve, an axially movable screw is provided on the valve cover, one end of the screw is fixedly connected to the pilot valve needle, and the other end extends out of the valve cover and is connected to a handle.

[0010] In the above-mentioned hydraulically controlled manually released normally open valve, a guide block is arranged at the upper end of the valve seat, the guide block is loosely fitted in the valve seat and a return spring is arranged between the guide block and the valve seat, and the guide block is fixed to the middle of the screw.

[0011] In the above-mentioned hydraulically controlled manually released normally open valve, the outer ring of the lower end of the valve core is a sloped structure, and the contact sealing portion between the oil outlet and the valve core is also a sloped structure with the same inclination angle.

[0012] In the above-mentioned hydraulically controlled manually released normally open valve, the matching surfaces of the valve body and the valve seat are provided with a retaining ring and an O-ring three, and the bottom of the valve seat is provided with a flat gasket.

[0013] In the above-mentioned hydraulically controlled manually released normally open valve, the valve body, valve seat and valve cover are all made of 617 brass, and the valve core and pilot valve needle are all made of 304 stainless steel.

[0014] Compared with the prior art, the hydraulically controlled manual release normally open valve has the following advantages:

[0015] 1. The external pressure required to control and maintain the hydraulic oil in the cut-off state is small, and the operator's hands do not need to be in a state of force for a long time. That is, the external pressure only needs to be greater than the elastic force of the spring to make the valve core move and contact and seal with the oil outlet. After sealing, the valve core is self-locking due to the oil pressure;

[0016] 2. The movement and sealing of the valve core are controlled by the mechanical structure, which has a simple structure, low manufacturing cost and good stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a cross-sectional structural diagram of a normally open valve;

[0018] Figure 2 yes Figure 1 A magnified view of the structure at center A;

[0019] Figure 3 yes Figure 1 A magnified view of the structure at B in the middle;

[0020] In the figure, 1, valve body; 2, valve seat; 2a, upper sealing groove; 2b, lower sealing groove; 3, valve cover; 4, valve core; 4a, cavity structure; 4b, through hole; 5, oil inlet; 6, oil outlet; 7, return spring; 8, hydraulic flow channel; 9, pilot valve needle; 10, oil seal; 11, O-ring one; 12, pressure ring; 13, sealing collar; 14, O-ring two; 15, screw; 16, handle; 17, guide block; 18, return spring; 19, inclined surface structure; 20, retaining ring; 21, O-ring three; 22, flat washer. DETAILED DESCRIPTION

[0021] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0022] like Figures 1 to 3 As shown, the hydraulically controlled manually released normally open valve comprises a valve body 1, a valve seat 2, a valve cover 3 and a valve core 4. The valve body 1, the valve seat 2 and the valve cover 3 are fastened together to form a whole, and the fitting method is threaded fitting and fixing.

[0023] The valve core 4 is clearance-fitted in the valve body 1 and can move axially. The end of the valve body 1 has a radially opened oil inlet 5 and an axially opened oil outlet 6. One axially movable end is limited by the valve seat 2 and the other end is limited by the structure at the oil outlet 6. The normally open valve is installed and fixed on the hydraulic equipment through the valve body 1.

[0024] The inner center of the valve core 4 has a through-type cavity structure 4a and a through hole 4b, which are located on the same axis and are interconnected. The diameter of the cavity structure 4a is larger than the diameter of the through hole 4b. A return spring 7 is arranged in the cavity structure 4a, and the two ends of the return spring 7 respectively abut against the step in the cavity structure 4a and the oil outlet 6 in the valve body 1. The return spring 7 is in a compressed state and causes the valve core 4 to move up in the absence of external force, so that the normally open valve is turned on.

[0025] At least one hydraulic channel 8 is axially opened on the side wall of the valve core 4, and a pilot valve needle 9 is axially arranged inside the valve seat 2. The end of the pilot valve needle 9 matches the position of the through hole 4b on the valve core 4 and the diameter of the pilot valve needle 9 is larger than the diameter of the through hole 4b. The function of the hydraulic channel 8 is to allow the hydraulic oil to enter the cavity above the valve core 4 when the valve core 4 moves downward. The end of the pilot valve needle 9 is a needle tip structure, which can make the sealing effect better when in contact.

[0026] Specific reference Figure 2 , further explained, the inner radial protrusion of the valve seat 2 forms two sealing grooves, namely the lower sealing groove 2b and the upper sealing groove 2a. The protrusion can support the middle section of the pilot valve needle 9 to prevent it from bending and breaking when in action. The lower sealing groove 2b is provided with an oil seal 10 and an O-ring 11. The inner surface of the oil seal 10 contacts the pilot valve needle 9. The outer surface of the oil seal 10 is an arc surface structure and the O-ring 11 is sleeved outside the oil seal 10. The lower part of the oil seal 10 is fixed in the lower sealing groove 2b by a pressure ring 12. The setting structure of the O-ring 11 can not only generate an inward pressure on the oil seal 10 to increase the sealing performance of the contact surface of the pilot valve needle 9, but also increase the sealing performance of the contact surface of the valve seat 2. In addition, the design of the arc surface structure of the oil seal 10 cooperates with the pressure ring 12 so that the hydraulic oil can generate a radial pressure on it, further increasing the sealing performance of the contact surface between the oil seal 10 and the pilot valve needle 9.

[0027] A sealing ring 13 is provided in the upper sealing groove 2a, and the sealing ring 13 has a countersunk structure and is provided with an O-ring 14. The sealing ring 13 and the O-ring 14 are in contact and sealed with the pilot valve needle 9 at the same time. This structure is designed to replace the seal when the sealing structure in the lower sealing groove 2b fails, so that the whole has double sealing performance.

[0028] The valve cover 3 is provided with an axially movable screw rod 15 , one end of which is fixedly connected to the pilot valve needle 9 , and the other end of the screw rod 15 extends out of the valve cover 3 and is connected to a handle 16 . The movement of the pilot valve needle 9 is achieved by applying an external force to the handle 16 .

[0029] A guide block 17 is provided at the upper end of the valve seat 2. The guide block 17 is fitted in the valve seat 2 with a clearance and a return spring 18 is provided between the guide block 17 and the valve seat 2. The guide block 17 is fixed to the middle of the screw 15. The design of the guide block 17 can reduce the axial movement offset of the pilot valve needle 9, prevent the pilot valve needle 9 from bending, and provide better overall stability, so that the thrust required for the pilot valve needle 9 to move is greater than the sum of the elastic forces of the return spring 7 and the return spring 18. When the thrust disappears, the return spring 7 triggers the valve core 4 to rise, and the return spring 18 triggers the pilot valve needle 9 to rise.

[0030] Specific reference Figure 3 The outer ring of the lower end of the valve core 4 is a slope structure 19, and the contact sealing part of the oil outlet 6 and the valve core 4 is also a slope structure 19 with the same inclination angle. The design of this structure is used to increase the contact area of ​​the contact surface and increase the sealing performance, and can align the sealing surface when in contact.

[0031] As another technical solution for further increasing the sealing performance at the oil outlet 6, the reset spring 7 is designed as a two-stage structure, and a steel ball is placed at the connection between the two stages. The spring force above the steel ball is greater than the spring force below. This design prevents the steel ball from entering the valve core 4 when the valve core 4 moves downward. Half of the steel ball is located inside the valve core 4 and half protrudes outside the valve core 4. When the valve core 4 descends, the steel ball can contact the hole structure at the oil outlet 6 to achieve further sealing. The diameter of the steel ball is greater than the diameter of the oil outlet 6.

[0032] The matching surfaces of the valve body 1 and the valve seat 2 are provided with a retaining ring 20 and an O-ring 21, and the bottom of the valve seat 2 is provided with a flat gasket 22. Since there is hydraulic oil at the upper end of the valve body 1, this structure is used to increase the sealing and fitting tightness between the valve body 1 and the valve seat 2.

[0033] In the normally open valve, the valve body 1, the valve seat 2 and the valve cover 3 are all made of No. 617 brass, and the valve core 4 and the pilot valve needle 9 are all made of No. 304 stainless steel, and the above materials are all existing materials.

[0034] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0035] Although various terms are used more frequently in this article, the possibility of using other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional restrictions is contrary to the spirit of the present invention.

Claims

1. A hydraulically controlled manually released normally open valve, comprising a valve body (1), a valve seat (2), a valve cover (3) and a valve core (4), wherein the valve body (1), the valve seat (2) and the valve cover (3) are mutually fastened to form a whole, the valve core (4) is loosely fitted in the valve body (1) and can move axially, the end of the valve body (1) has a radially opened oil inlet (5) and an axially opened oil outlet (6), characterized in that: The inner center of the valve core (4) has a through-type cavity structure (4a) and a through hole (4b), the cavity structure (4a) and the through hole (4b) are located on the same axis and are interconnected, a return spring (7) is arranged in the cavity structure (4a), the two ends of the return spring (7) respectively abut against the step in the cavity structure (4a) and the oil outlet (6) in the valve body (1), at least one hydraulic flow channel (8) is axially opened on the side wall of the valve core (4), a pilot valve needle (9) is axially arranged inside the valve seat (2), the end of the pilot valve needle (9) matches the position of the through hole (4b) on the valve core (4), and the diameter of the pilot valve needle (9) is larger than the diameter of the through hole (4b); the inner radial protrusion of the valve seat (2) forms two sealing grooves, namely a lower sealing groove (2b) and an upper sealing groove (2a), and the protrusion is shaped to contact the middle section of the pilot valve needle (9). The support is formed, an oil seal (10) and an O-ring (11) are clamped in the lower sealing groove (2b), the inner surface of the oil seal (10) is in contact with the pilot valve needle (9), the outer surface of the oil seal (10) is an arc surface structure and the O-ring (11) is sleeved outside the oil seal (10), and the lower part of the oil seal (10) is fixed in the lower sealing groove (2b) by a pressure ring (12); a sealing ring (13) is clamped in the upper sealing groove (2a), the sealing ring (13) has a countersunk structure and is provided with an O-ring (14), and the sealing ring (13) and the O-ring (14) are in contact with the pilot valve needle (9) at the same time to seal; an axially movable screw (15) is provided on the valve cover (3), one end of the screw (15) is connected and fixed to the pilot valve needle (9), and the other end extends out of the valve cover (3) and is connected to a handle (16).

2. The hydraulically controlled manual release normally open valve according to claim 1, characterized in that: A guide block (17) is provided at the upper end of the valve seat (2). The guide block (17) is loosely fitted in the valve seat (2) and a return spring (18) is provided between the guide block (17) and the valve seat (2). The guide block (17) and the middle part of the screw rod (15) are fixed to each other.

3. The hydraulically controlled manual release normally open valve according to claim 1, characterized in that: The outer ring of the lower end of the valve core (4) is a sloped surface structure (19), and the contact sealing portion between the oil outlet (6) and the valve core (4) is also a sloped surface structure (19) with the same inclination angle.

4. The hydraulically controlled manually released normally open valve according to claim 1, characterized in that: The matching surfaces of the valve body (1) and the valve seat (2) are provided with a retaining ring (20) and an O-ring three (21), and the bottom of the valve seat (2) is provided with a flat gasket (22).

5. The hydraulically controlled manually released normally open valve according to claim 1, characterized in that: The valve body (1), valve seat (2) and valve cover (3) are all made of No. 617 brass, and the valve core (4) and pilot valve needle (9) are all made of No. 304 stainless steel.

Images