Ultra-high pressure proportional unloading valve

Abstract

The present invention relates to the technical field of unloading valves, and specifically to an ultra-high pressure proportional unloading valve, aiming to solve the technical problem that the system pressure is not proportional to time in the later stage of pressure relief of an isostatic pressure chamber. The following technical solutions are adopted: It includes a main pressure relief mechanism, a pilot control mechanism, and a hydraulic drive mechanism arranged in sequence from bottom to top. The main pressure relief mechanism includes a lower valve body, a valve seat, and a floating valve core. The pilot control mechanism includes an upper valve body, a fixed valve core, and a flow-limiting valve core. The hydraulic drive mechanism includes a piston and a piston gland. The main pressure relief mechanism is used to undertake most of the tasks of pressure relief. The pilot control mechanism is mainly used to control the main pressure relief mechanism. Only when the pilot control mechanism is activated can the main pressure relief mechanism be activated. Moreover, the adjustment method for the main pressure relief mechanism is a continuous slow-down type, avoiding excessive pressure relief impact caused by the direct connection between the main pressure relief mechanism and the hydraulic drive mechanism, thereby ensuring the service life of the unloading valve.

Description

Technical Field

[0001] The present invention relates to the technical field of unloading valves, and in particular to an ultra-high pressure proportional unloading valve. Background Art

[0002] During the use of an isostatic press, it is often necessary to controllably reduce the working pressure in proportion to time. Currently, the following method is usually adopted for pressure relief: An exhaust port with a fixed size is opened in the isostatic pressing cavity, and a switch for controlling its opening and closing is configured. By opening the exhaust port, the liquid in the cavity is allowed to achieve stepped pressure relief over time. However, the above method has certain defects: As the system pressure decreases, the flow rate of the discharged liquid will decrease, resulting in the inability to relieve the system pressure in proportion to time in the later stage of work and failing to meet industrial requirements. Summary of the Invention

[0003] The present invention aims to solve the technical problem that the system pressure and time are not proportional in the later stage of pressure relief in the existing isostatic pressing cavity.

[0004] The technical solution adopted by the present invention to solve its technical problems is as follows:

[0005] Ultra-high pressure proportional unloading valve, comprising a main pressure relief mechanism (assuming the main pressure relief function) arranged successively from bottom to top, a pilot control mechanism (which is a prerequisite for the operation of the main pressure relief mechanism and plays a pilot control role for the main pressure relief mechanism), and a hydraulic drive mechanism (which is the adjustment power for the entire unloading valve, and changing the magnitude of the input hydraulic pressure can change the state of the unloading valve); the main pressure relief mechanism includes a lower valve body, a valve seat, and a floating valve core. A first through hole with its axis arranged vertically is provided in the middle of the lower valve body. The first through hole is a stepped hole with a larger diameter at the bottom. The valve seat is threadedly connected to the larger diameter hole of the first through hole, and the side wall at the top of the valve seat is hermetically connected to the wall of the larger diameter hole of the first through hole. The valve seat is provided with a second through hole coaxial with the first through hole. A floating valve core is slidably installed in the upper part of the second through hole, and the outer wall of the upper part of the floating valve core is hermetically connected to the inner wall of the second through hole. The diameter of the middle part of the second through hole in the axial direction is reduced to form a limiting part adapted to the lower end face of the floating valve core, and the two are hermetically connected. The floating valve core floats between the limiting part and the stepped surface of the first through hole. The lower valve body and the valve seat jointly form a first pressure relief channel. The inner end of the first pressure relief channel (the first pressure relief channel is used to discharge the liquid in the high-pressure cavity, including two sections located in the lower valve body and the valve seat. Since the valve seat is located inside the lower valve body, the inner end is the end located in the valve seat) is adjacent to the upper part of the limiting part. A third through hole coaxial with the second through hole is provided in the floating valve core. A spring is placed in the third through hole, and the diameter of the lower end of the third through hole is reduced to form a supporting part; the pilot control mechanism includes an upper valve body, a fixed valve core, and a flow-limiting valve core. The upper valve body is hermetically fixed to the upper end of the lower valve body. The fixed valve core is clamped and fixed between the upper valve body and the lower valve body. The two ends of the spring respectively abut against the fixed valve core and the supporting part. The upper valve body is provided with a fourth through hole coaxial with the third through hole. The fixed valve core is provided with a fifth through hole coaxial with the fourth through hole. The upper part of the fixed valve core is placed in the lower part of the fourth through hole. The flow-limiting valve core is located in the fourth through hole. The flow-limiting valve core is a barrel-shaped structure with an opening facing downwards and is sleeved outside the upper part of the fixed valve core with a gap (the purpose of the gap sleeve is to allow the liquid to flow through the gap between the two). A sealing cover body for sealing the fifth through hole is arranged between the flow-limiting valve core and the fixed valve core or the flow-limiting valve core is integrated with the sealing cover body. A flow-limiting channel is formed between the flow-limiting valve core and the wall of the fourth through hole. A second pressure relief channel is formed inside the upper valve body, and the second pressure relief channel is communicated with the flow-limiting channel; the hydraulic drive mechanism includes a piston and a piston gland. The piston gland is hermetically fixed to the upper end of the fourth through hole. The piston is located between the piston gland and the flow-limiting valve core and abuts against the flow-limiting valve core. The piston gland is provided with an oil injection hole.

[0006] The beneficial effects of the present invention are as follows:

[0007] 1) The ultra-high pressure proportional unloading valve of the present invention is provided with a hydraulic drive mechanism, which can control the pressure of the liquid in the high-pressure cavity by controlling the pressure of the hydraulic oil input to the hydraulic drive mechanism, so as to achieve controllable unloading;

[0008] 2) In the ultra-high pressure proportional unloading valve of the present invention, a pilot control mechanism is provided between the hydraulic drive mechanism and the main pressure relief mechanism. The main pressure relief mechanism is used to undertake most of the tasks of pressure relief. The pilot control mechanism is mainly used to control the main pressure relief mechanism. Only when the pilot control mechanism is activated can the main pressure relief mechanism be activated. Moreover, the adjustment method for the main pressure relief mechanism is a continuous slow-down type, which avoids excessive pressure relief shock caused by the direct connection between the main pressure relief mechanism and the hydraulic drive mechanism, thus ensuring the service life of the unloading valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0010] Figure 1 is a schematic structural diagram of the ultra-high pressure proportional unloading valve;

[0011] Figure 2 is Figure 1 in is a partial enlarged view of the part;

[0012] Figure 3 is Figure 1 in is a partial enlarged view of the part.

[0013] In the figure:

[0014] 1 - lower valve body; 2 - valve seat; 3 - floating valve core; 4 - first pressure relief channel; 5 - spring; 6 - upper valve body; 7 - fixed valve core; 8 - current-limiting valve core; 9 - sealing cover body; 10 - current-limiting channel; 11 - second pressure relief channel; 12 - piston; 13 - piston gland; 14 - oil injection hole. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0015] In order to make the purpose, technical solutions and advantages of the present application clearer, the following will further describe the present application in detail with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0016] Refer to Figures 1 to 3, a super-high-pressure proportional unloading valve, comprising a main pressure relief mechanism, a pilot control mechanism, and a hydraulic drive mechanism arranged in sequence from bottom to top; the main pressure relief mechanism includes a lower valve body 1, a valve seat 2, and a floating valve core 3. A first through hole with an axis arranged vertically is provided in the middle of the lower valve body 1. The first through hole is a stepped hole with a larger diameter at the lower part, i.e., a first-stage stepped hole. The valve seat 2 is threadedly connected to the larger-diameter hole of the first through hole, and the side wall at the top of the valve seat 2 is in sealing contact with the wall of the larger-diameter hole of the first through hole. Sealing contact is a technique well-known to those skilled in the art. In specific implementation, a sealing ring or the like can be used for sealing; the valve seat 2 is provided with a second through hole coaxial with the first through hole. A floating valve core 3 is slidably installed in the upper part of the second through hole, and the outer wall of the upper part of the floating valve core 3 is in sealing contact with the inner wall of the second through hole. Sliding installation is a technique well-known to those skilled in the mechanical field. In specific implementation, a clearance fit can be achieved between the outer wall of the floating valve core 3 and the inner wall of the second through hole. Sealing contact is achieved by installing a sealing ring on the outer wall of the floating valve core 3 or the inner wall of the second through hole; the diameter of the middle part of the second through hole in the axial direction is reduced to form a limiting part adapted to the lower end face of the floating valve core 3, and the two are in sealing contact. In specific implementation, the limiting part can be processed into a conical surface, a stepped surface, etc., as long as it can play a role in limiting the lower position of the floating valve core 3. The sealing contact between the lower end face of the floating valve core 3 and the limiting part can be achieved by installing a sealing ring on the limiting part or the lower end face of the floating valve core 3. This is easy to design by those skilled in the art; the floating valve core 3 floats between the limiting part and the stepped surface of the first through hole. The lower valve body 1 and the valve seat 2 jointly form a first pressure relief channel 4. In specific implementation, the first pressure relief channel 4 can be processed into the straight channel shape shown in the figure, or can be processed into a curved channel shape or other shapes; the inner end of the first pressure relief channel 4 is adjacent to the upper part of the limiting part. A third through hole coaxial with the second through hole is provided in the floating valve core 3. A spring 5 is placed in the third through hole, and the diameter of the lower end of the third through hole is reduced to form a supporting part for supporting the spring 5. In specific implementation, it can be processed into a conical surface or a flat surface as shown in the figure; the pilot control mechanism includes an upper valve body 6, a fixed valve core 7, and a flow-limiting valve core 8. The upper valve body 6 is fixedly sealed at the upper end of the lower valve body 1. Fixed sealing is a technique well-known to those skilled in the art. In specific implementation, connection structures such as sealing rings combined with threads, buckles, welding, etc. can be used. Here, the connection between the upper valve body 6 and the lower valve body 1 is preferably a detachable method such as bolts and buckles, which can be disassembled and assembled for easy maintenance; the fixed valve core 7 is clamped and fixed between the upper valve body 6 and the lower valve body 1. Clamping and fixing can be achieved through various well-known structures in the art as long as the fixed valve core 7 is clamped in the middle by the upper valve body 6 and the lower valve body 1;Both ends of the spring 5 are respectively abutted against and fixed to the fixed valve core 7 and the support part. The upper valve body 6 is provided with a fourth through hole coaxial with the third through hole. The fixed valve core 7 is provided with a fifth through hole coaxial with the fourth through hole. The upper part of the fixed valve core 7 is placed in the lower part of the fourth through hole. The flow-limiting valve core 8 is located in the fourth through hole. The flow-limiting valve core 8 is a barrel-shaped structure with an opening facing downwards and is sleeved outside the upper part of the fixed valve core 7 with a gap. A sealing cover body 9 for sealing the fifth through hole is arranged between the flow-limiting valve core 8 and the fixed valve core 7 or the flow-limiting valve core 8 is integrated with the sealing cover body 9. Specifically in design, the sealing cover body 9 can be a part of the flow-limiting valve core 8 or a component separately placed between the flow-limiting valve core 8 and the fixed valve core 7, such as a sphere, etc.; A flow-limiting channel 10 is formed between the flow-limiting valve core 8 and the hole wall of the fourth through hole. A second pressure relief channel 11 is formed in the upper valve body 6. Specifically in implementation, the second pressure relief channel 11 can be set as a straight channel or a curved channel as shown in the figure, etc.; The second pressure relief channel 11 communicates with the flow-limiting channel 10; The hydraulic driving mechanism includes a piston 12 and a piston gland 13. The piston gland 13 is hermetically fixed at the upper end of the fourth through hole. The piston 12 is located between the piston gland 13 and the flow-limiting valve core 8 and abuts against the flow-limiting valve core 8. The piston gland 13 is provided with an oil injection hole 14.;

[0017] During operation, when the high-pressure cavity needs to unload, first control the input of hydraulic oil with a specific pressure into the hydraulic driving mechanism from the oil injection hole 14. It is necessary to ensure that the pressure of the input hydraulic oil is less than the pressure required for the balance of the piston 12. At this time, regarding the sealing cover body 9, the flow-limiting valve core 8, and the piston 12 as a whole, the force on the lower part of this whole is greater than the force on the upper part. Therefore, it will move upward to disengage from the upper end of the fifth through hole. The liquid in the high-pressure cavity will sequentially pass through the second through hole, the third through hole, the first through hole, the fifth through hole, the gap between the fixed valve core 7 and the flow-limiting valve core 8, the flow-limiting channel 10, and the second pressure relief channel 11 and then be discharged. At this time, the pressure of the hydraulic oil above the floating valve core 3 will decrease, resulting in the force on the upper part of the floating valve core 3 being less than the force on the lower part. The floating valve core 3 will move upward, making the inner end of the first pressure relief channel 4 communicate with the high-pressure cavity. The liquid in the high-pressure cavity is discharged through the first pressure relief channel 4 for pressure relief; When the pressure of the high-pressure cavity becomes smaller to a certain extent, such that the force on the lower part of the sealing cover body 9 is less than the force on the upper part, then the piston 12, the flow-limiting valve core 8, and the sealing cover body 9 will move downward as a whole, causing the sealing cover body 9 to close the fifth through hole. The pilot control mechanism is closed. The floating valve core 3 moves to the limiting part under the action of the spring 5, causing the main pressure relief structure to also close and stop pressure relief. By adjusting the pressure of the hydraulic oil in the hydraulic control mechanism, the pressure of the liquid in the high-pressure cavity is adjusted, thereby realizing controllable pressure relief.

[0018] Preferably, the fourth through-hole is a first-stage stepped hole with a small-diameter hole at the lower part. The piston gland 13 is threadedly connected to the inner wall of the upper part of the large-diameter hole of the fourth through-hole. The piston 12 is a stepped piston composed of a large-diameter part and a small-diameter part. The large-diameter part of the piston 12 is located at the lower part of the large-diameter hole of the fourth through-hole and can slide between the piston gland 13 and the stepped surface of the fourth through-hole. The small-diameter part of the piston 12 is located at the upper part of the small-diameter hole of the fourth through-hole and abuts against the top surface of the flow-limiting valve core 8. Such a structural arrangement can achieve small-pressure control of large-pressure. The principle analysis is as follows: When the piston 12 is in balance, the upper and lower pressures are equal. Pressure = pressure × force-bearing area. When a stepped piston is used, the force-bearing area at the lower part decreases, so the pressure required to reach balance is larger. That is, to control a high-pressure chamber with a certain pressure, a smaller pressure can be input to the hydraulic drive mechanism.

[0019] Preferably, the flow-limiting valve core 8 is provided with an external thread. A flow-limiting channel 10 is formed between the external thread of the flow-limiting valve core 8 and the inner wall of the fourth through-hole. The threaded flow-limiting channel 10 is easy to machine and has stable performance.

[0020] Furthermore, the fifth through-hole is a first-stage stepped hole with a small-diameter hole at the upper part. The sealing cover body 9 is spherical. The upper end surface of the fixed valve core 7 is provided with a spherical surface adapted to the sealing cover body 9. The central axis of the spherical surface is coaxial with the fifth through-hole. The structural cooperation between the stepped hole and the spherical sealing cover body 9 makes the force-bearing area corresponding to the liquid in the high-pressure chamber smaller. In this way, the liquid pressure required in the hydraulic drive mechanism becomes smaller, the control cost is lower, and the energy consumption is lower.

[0021] Preferably, the outer diameter of the lower end of the floating valve core 3 becomes smaller to form a conical side surface. The limiting part is a conical side surface adapted to the lower end of the floating valve core 3. The conical side surface makes the movement of the floating valve core 3 smoother, without jamming, and is conducive to the arrangement of the sealing structure.

[0022] Preferably, the lower part of the fixed valve core 7 is a structure formed by two coaxial frustums with large-diameter bottoms facing each other. The axis of the frustum of the fixed valve core 7 is coaxial with the first through-hole. The upper end of the first through-hole and the lower end of the fourth through-hole both have enlarged flared parts in the shape of a frustum. The lower part of the fixed valve core 7 is clamped and fixed in the two flared parts. Such a structure makes the force direction of the fixed valve core 7 perpendicular to the conical side surface, not straight up or down, avoiding the failure of the connection between the upper and lower valve bodies 1 due to excessive force on the fixed valve core 7.

[0023] In the accompanying drawings of the embodiments, the same or similar reference numerals correspond to the same or similar components; in the description of the present application, it should be understood that if there are terms such as "upper", "lower", "left", "right", etc. indicating the orientation or positional relationship, it is based on the orientation or positional relationship shown in the accompanying drawings. This is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the accompanying drawings are only for illustrative purposes and should not be construed as a limitation of this patent. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0024] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. Ultra-high pressure proportional unloading valve, characterized in that: It includes a main pressure relief mechanism, a pilot control mechanism, and a hydraulic drive mechanism arranged in sequence from bottom to top; the main pressure relief mechanism includes a lower valve body (1), a valve seat (2), and a floating valve core (3). A first through hole with an axis arranged vertically is provided in the middle of the lower valve body (1). The first through hole is a stepped hole with a larger diameter at the bottom, and the valve seat (2) is threadedly connected to the larger-diameter hole of the first through hole, and the side wall at the top of the valve seat (2) is hermetically connected to the wall of the larger-diameter hole of the first through hole. The valve seat (2) is provided with a second through hole coaxial with the first through hole. A floating valve core (3) is slidably fitted in the upper part of the second through hole, and the outer wall of the upper part of the floating valve core (3) is hermetically connected to the inner wall of the second through hole. The diameter of the middle part of the second through hole in the axial direction is reduced to form a limiting part adapted to the lower end face of the floating valve core (3), and the two are hermetically connected. The floating valve core (3) floats between the limiting part and the stepped surface of the first through hole. The lower valve body (1) and the valve seat (2) jointly form a first pressure relief channel (4). The inner end of the first pressure relief channel (4) is adjacent to the upper part of the limiting part. A third through hole coaxial with the second through hole is provided in the floating valve core (3). A spring (5) is placed in the third through hole, and the diameter of the lower end of the third through hole is reduced to form a supporting part; the pilot control mechanism includes an upper valve body (6), a fixed valve core (7), and a flow-limiting valve core (8). The upper valve body (6) is hermetically fixed to the upper end of the lower valve body (1). The fixed valve core (7) is clamped and fixed between the upper valve body (6) and the lower valve body (1). The two ends of the spring (5) respectively abut against the fixed valve core (7) and the supporting part. The upper valve body (6) is provided with a fourth through hole coaxial with the third through hole. The fixed valve core (7) is provided with a fifth through hole coaxial with the fourth through hole. The upper part of the fixed valve core (7) is placed in the lower part of the fourth through hole. The flow-limiting valve core (8) is located in the fourth through hole. The flow-limiting valve core (8) is a barrel-shaped structure with an opening facing downwards and is sleeved on the outside of the upper part of the fixed valve core (7) with a gap. A sealing cover body (9) for sealing the fifth through hole is arranged between the flow-limiting valve core (8) and the fixed valve core (7) or the flow-limiting valve core (8) is integrated with the sealing cover body. A flow-limiting channel (10) is formed between the flow-limiting valve core (8) and the wall of the fourth through hole. A second pressure relief channel (11) is formed in the upper valve body (6). The second pressure relief channel (11) is communicated with the flow-limiting channel (10); the hydraulic drive mechanism includes a piston (12) and a piston gland (13). The piston gland (13) is hermetically fixed to the upper end of the fourth through hole. The piston (12) is located between the piston gland (13) and the flow-limiting valve core (8) and abuts against the flow-limiting valve core (8). The piston gland (13) is provided with an oil injection hole (14).

2. The ultra-high pressure proportional unloading valve according to claim 1, wherein: The fourth through hole is a stepped hole with a smaller diameter at the bottom. The piston gland (13) is threadedly connected to the inner wall of the upper part of the larger-diameter hole of the fourth through hole. The piston (12) is a variable-diameter piston composed of a larger-diameter part and a smaller-diameter part. The larger-diameter part of the piston (12) is located in the lower part of the larger-diameter hole of the fourth through hole and can slide between the piston gland (13) and the stepped surface of the fourth through hole. The smaller-diameter part of the piston (12) is located in the upper part of the smaller-diameter hole of the fourth through hole and abuts against the top surface of the flow-limiting valve core (8).

3. The ultra-high pressure proportional unloading valve according to claim 2, wherein: The flow-limiting valve core (8) is provided with an external thread, and a flow-limiting channel (10) is formed between the external thread of the flow-limiting valve core (8) and the inner wall of the fourth through hole.

4. The ultra-high pressure proportional unloading valve according to claim 3, characterized in that: The fifth through hole is a first-stage stepped hole with a small-diameter hole located above. The upper end face of the fixed valve core (7) is set as a spherical surface adapted to the sphere, and the central axis of the spherical surface is coaxial with the fifth through hole.

5. The ultra-high pressure proportional unloading valve according to any one of claims 1-4, characterized in that: The outer diameter of the lower end of the floating valve core (3) becomes smaller to form the side surface of a frustum of a cone, and the limiting part is the side surface of a frustum of a cone adapted to the lower end of the floating valve core (3).

6. The ultra-high pressure proportional unloading valve according to claim 5, characterized in that: The lower part of the fixed valve core (7) is a structure formed by two frustums of a cone with the same axis and the large-diameter bottom surfaces facing each other. The axis of the frustum of the cone of the fixed valve core (7) is coaxial with the first through hole. The upper end of the first through hole and the lower end of the fourth through hole both have a diameter that becomes larger to form a flared part in the shape of a frustum of a cone, and the lower part of the fixed valve core (7) is clamped and fixed within the two flared parts.

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