A relief valve with a guide structure

Abstract

This utility model discloses an overflow valve with a guiding structure, comprising a valve sleeve and a spring. A conical valve core and a spring seat are housed within the cavity of the valve sleeve. A locking nut is fixedly installed at the tail of the valve sleeve, and a set screw is screwed into the locking nut. The front end of the set screw abuts against the bottom surface of the spring seat. A spring seat B is connected to the top surface of the spring seat via a steel ball. A spring seat A is slidably connected directly above spring seat B and located at the upper part of the valve sleeve cavity. A spring is installed between spring seat B and spring seat A. Guide cavities are correspondingly formed in the middle of spring seat A and the middle of spring seat B. The conical valve core is sequentially inserted into the guide cavities of spring seat A and spring seat B. A filter screen base is installed at the inlet of the valve sleeve, and a filter screen plug is provided at the front end of the filter screen base. A filter screen is installed between the filter screen base and the filter screen plug. This utility model provides stable support to the conical valve core through the guiding cavity structure of the spring seat, ensuring smooth opening and closing of the conical valve core and eliminating mechanical vibration.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic valve technology, and specifically to an overflow valve with a guide structure. Background Technology

[0002] Explosion-proof valves are composite valves commonly used in hydraulic systems of construction machinery. In hydraulic equipment such as excavators and loaders, these products are typically installed in the actuator cylinder circuit to achieve unidirectional free flow and reverse throttling control, ensuring smooth cylinder movement and controllable speed. They also prevent hydraulic shock and the rapid fall of mechanical parts within the system. To ensure the safety of the hydraulic system under high pressure and sudden load changes, explosion-proof valves usually integrate a relief valve structure to limit the maximum system pressure. When the oil pressure exceeds the set value, the relief valve opens, bypassing some of the high-pressure oil back to the oil tank, thereby relieving system pressure and preventing damage to the cylinder, oil pipes, and pump body.

[0003] In the CMV series explosion-proof valves, the upward flow (V2-C2) is unrestricted, while the downward flow (C2-V2) is controlled by a sliding cone valve core and a relief valve, remaining closed under the action of spring force and the load port C2. The relief valve in this explosion-proof valve can detect the pressure at port C2 and open under overload or impact conditions, thereby pushing the piston, causing the sliding cone valve core to move and releasing the downward flow.

[0004] like Figure 1 The diagram shown is a schematic of an existing explosion-proof valve. It consists of a main valve core 1, an overflow valve 2, and a one-way throttle valve 3. The overflow valve 3 can open when the pressure at port C2 exceeds the set value, helping the main valve core 1 to open. During operation, due to insufficient guidance of the overflow valve core or uneven flow field, it is easy to generate whistling and valve core vibration, which affects the system stability and noise performance.

[0005] Because the relief valve controls the sliding of the pilot piston and has low flow requirements, existing relief valves are all direct-acting type. However, because direct-acting relief valves respond quickly, they are prone to whistling and vibration. For example... Figure 2 As shown, this is a structural diagram of an existing overflow valve. The valve core has no guiding structure. When the valve core is opened, it tilts due to the deviation of the valve core trajectory. The flow velocity and pressure distribution of the fluid on both sides of the valve port are uneven, and friction and jamming occur between the valve core and the valve body. Summary of the Invention

[0006] The purpose of this utility model is to address the shortcomings of the prior art by providing an overflow valve with a guide structure. The guide structure provides stable support to the cone valve core, making the cone valve core open and close smoothly and eliminating mechanical vibration.

[0007] The technical solution adopted in this utility model is as follows: An overflow valve with a guide structure includes a valve sleeve and a spring. The valve sleeve has a cavity at its center, with an inlet at the top communicating with it. A conical valve core and a spring seat are housed within the cavity. A locking nut is fixedly installed at the tail of the valve sleeve, and a set screw is screwed into the locking nut. The front end of the set screw abuts against the bottom surface of the spring seat. A spring seat B is connected to the top surface of the spring seat via a steel ball. A spring seat A is slidably connected directly above spring seat B and located at the upper part of the valve sleeve cavity. One end of the spring is connected to spring seat B, and the other end of the spring is connected to a spring... On seat A, guide cavities are correspondingly opened in the middle of spring seat A and spring seat B. The cone valve core is inserted into the guide cavities of spring seat A and spring seat B in sequence. A filter screen base is installed at the inlet of the valve sleeve. A filter screen plug is provided at the front end of the filter screen base. A first valve hole is opened in the middle of the filter screen base and the filter screen plug corresponding to the position of the valve sleeve inlet. A filter screen is installed between the filter screen base and the filter screen plug. The cone tip of the cone valve core is inserted into the first valve hole to achieve sealing. A second valve hole is provided radially through on the front side of the valve sleeve. The second valve hole is connected to the cavity of the valve sleeve.

[0008] Preferably, the outer side of the valve sleeve is provided with an annular groove, and a first O-ring and an elastic retaining ring are sequentially engaged in the annular groove from front to back.

[0009] Preferably, the outer side of the spring seat is provided with an annular groove, and a second O-ring and an open retaining ring are sequentially engaged in the annular groove from front to back.

[0010] Preferably, the set screw is a hexagonal flat-end set screw.

[0011] Preferably, a filter screen base is installed at the inlet of the valve sleeve by a snap-fit ​​method.

[0012] Preferably, there is an interference fit between the filter base and the filter plug.

[0013] Preferably, the guide clearance between the cone valve core and spring seat A and spring seat B is 0.03 to 0.13 mm.

[0014] Preferably, the guide cavity in spring seat A, the guide cavity in spring seat B, and the cavity in valve sleeve are all coaxially arranged.

[0015] The beneficial effects of this utility model are: (1) This utility model provides spring seats with guide cavities at the front end and middle of the valve sleeve cavity, so that the cone valve core inserted into the guide cavities of the two spring seats in sequence can maintain a stable axial movement state under the action of high pressure fluid, thereby eliminating the vibration and whistling caused by the offset of the cone valve core and extending the service life of the cone valve core. (2) A specific gap is provided between the cone valve core and the guide cavity of spring seat A and spring seat B in this utility model, so as to control the oil damping and lubrication. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of an existing explosion-proof valve. Figure 2 This is a structural diagram of an existing overflow valve; Figure 3 This is a schematic diagram of the structure of this utility model; In the diagram: 1-valve sleeve; 2-set screw; 3-spring seat; 4-spring seat B; 5-cone valve core; 6-spring seat A; 7-filter base; 8-filter plug; 9-filter; 10-spring; 11-first O-ring; 12-elastic retaining ring; 13-steel ball; 14-second O-ring; 15-opening retaining ring; 16-lock nut; 17-first valve hole; 18-second valve hole. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings: like Figure 3 As shown, the present invention discloses an overflow valve with a guide structure, comprising a valve sleeve 1 and a spring 10. The valve sleeve 1 has a cavity in the center, and an inlet communicating with the cavity is provided at the top of the cavity. A cone valve core 5 and a spring seat 3 are provided in the cavity of the valve sleeve 1. A locking nut 16 is fixedly installed at the tail of the valve sleeve 1. An internal hexagonal set screw 2 is screwed into the locking nut 16. The front end of the internal hexagonal set screw 2 abuts against the bottom surface of the spring seat 3. Turning the internal hexagonal set screw 2 can adjust the position of the spring seat 3, thereby adjusting the compression degree of the spring 10 and adjusting the opening pressure of the overflow valve.

[0018] In this invention, the top surface of the spring seat 3 is connected to the spring seat B4 via a steel ball 13. The point contact connection of the steel ball 13 can reduce friction while maintaining positioning accuracy, making the cone valve core 5 subjected to uniform force. At the same time, the spherical contact allows for small-angle coupling, which helps to reduce the impact of dimensional errors during assembly on the movement of the cone valve core 5. Furthermore, the connection of the steel ball 13 is not prone to jamming, which can make the operation of the relief valve more stable.

[0019] In this invention, a spring seat A6 is slidably connected directly above the spring seat B4 and at the upper part of the valve sleeve 1 cavity. One end of the spring 10 is connected to the spring seat B4, and the other end of the spring 10 is connected to the spring seat A6. Guide cavities are correspondingly formed in the middle of the spring seat A6 and the middle of the spring seat B4. The cone valve core 5 is sequentially inserted into the guide cavities of the spring seat A6 and the spring seat B4, allowing the cone valve core 5 to maintain a stable axial movement posture under the action of high-pressure fluid. This eliminates vibration and whistling caused by the offset of the cone valve core 5, and improves the service life of the cone valve core 5. The guide clearance between the cone valve core 5 and the spring seats A6 and B4 is 0.03–0.13 mm. This small clearance allows for the formation of a stable lubricating oil film, ensuring the free sliding of the cone valve core 5 while simultaneously generating liquid film damping to suppress small-amplitude vibrations of the cone valve core 5. Combined with the high-gloss finish of the spring seats A6 and B4, the cone valve core 5 achieves fixed-axis sliding, maintaining its state for a long time and reducing the risk of whistling.

[0020] In this invention, a filter screen base 7 is installed at the inlet of the valve sleeve 1 by a snap-fit ​​method. A filter screen plug 8 is provided at the front end of the filter screen base 7, and the filter screen base 7 and the filter screen plug 8 are interference-fitted. A first valve hole 17 is opened at the middle of the filter screen base 7 and the filter screen plug 8 corresponding to the inlet of the valve sleeve 1. A filter screen 9 is installed between the filter screen base 7 and the filter screen plug 8, which can effectively prevent impurities in the system from entering the cavity of the valve sleeve 1 without affecting the sliding. A certain damping is formed before the oil enters the cavity of the valve sleeve 1, which not only plays a filtering role, but also reduces the sudden change in flow rate entering the cavity.

[0021] In this invention, the cone valve core 5 has its cone tip inserted into the first valve hole 17 to achieve sealing. The front side of the valve sleeve 1 has a radially penetrating second valve hole 18, which is connected to the cavity of the valve sleeve 1. When the pressure of the liquid entering through the first valve hole 17 exceeds the pressure of the spring 10, the cone valve core 5 can be pushed upward to achieve overflow unloading. When the cone valve core 5 moves up and down, it can adjust the opening of the first valve hole 17. The greater the pressure of the flow, the greater the upward stroke of the cone valve core 5 and the greater the opening.

[0022] The valve sleeve 1 of this invention has an annular groove on its outer side, and a first O-ring 11 and an elastic retaining ring 12 are sequentially engaged in the annular groove from front to back. The spring seat 3 has an annular groove on its outer side, and a second O-ring 14 and an open retaining ring 15 are sequentially engaged in the annular groove from front to back, so that the spring seat 3 and the cavity of the valve sleeve 1 are sealed together.

[0023] In this utility model, the guide cavity of spring seat A6, the guide cavity of spring seat B4, and the cavity of valve sleeve 1 are all coaxially arranged.

[0024] The usage process of this utility model is as follows: In use, the oil enters through the first valve hole 17. Before contacting the cone valve core 5, the oil flows through the filter screen 9, creating a certain damping effect before entering the valve sleeve 1 cavity. This not only serves as a filter but also reduces sudden changes in flow velocity within the cavity. When the oil pressure is sufficient to lift the cone valve core 5, it can overflow and unload through the second valve hole 18. If the overflow volume is too large or the overflow velocity is too fast, the cone valve core 5 is prone to pressure fluctuations and whistling within the valve sleeve 1 cavity. By setting spring seats A6 and B4 with guide cavities at the front and middle parts of the valve sleeve 1 cavity respectively, the cone valve core 5, inserted sequentially into the guide cavities of spring seats A6 and B4, can maintain a stable axial movement posture under the action of high-pressure fluid, thereby eliminating vibration and whistling caused by cone valve core misalignment and extending the service life of the cone valve core. When the oil flow stops, the cone valve core 5 resets under the guidance of spring seats A6 and B4, causing the first valve hole 17 to close smoothly without impact or vibration.

[0025] Other undescribed parts of this utility model are the same as those in the prior art.

Claims

1. A relief valve with a guiding structure, characterized in that: It includes a valve sleeve (1) and a spring (10). The valve sleeve (1) has a cavity in the center and an inlet connected to the top of the cavity. The cavity of the valve sleeve (1) contains a cone valve core (5) and a spring seat (3). A locking nut (16) is fixedly installed at the tail of the valve sleeve (1). A set screw (2) is screwed into the locking nut (16). The front end of the set screw (2) abuts against the bottom surface of the spring seat (3). The top surface of the spring seat (3) is connected to a spring seat B (4) through a steel ball (13). A spring seat A (6) is slidably connected above the spring seat B (4) and located at the top of the cavity of the valve sleeve (1). One end of the spring (10) is connected to the spring seat B (4), and the other end of the spring (10) is connected to the spring seat A (6). A guide cavity is provided in the middle of A (6) and the middle of the spring seat B (4). The cone valve core (5) is inserted into the guide cavity of the spring seat A (6) and the spring seat B (4) in sequence. A filter screen base (7) is installed at the inlet of the valve sleeve (1). A filter screen plug (8) is provided at the front end of the filter screen base (7). A first valve hole (17) is provided in the middle of the filter screen base (7) and the filter screen plug (8) corresponding to the inlet of the valve sleeve (1). A filter screen (9) is installed between the filter screen base (7) and the filter screen plug (8). The cone tip of the cone valve core (5) is inserted into the first valve hole (17) to achieve sealing. A second valve hole (18) is provided on the front side of the valve sleeve (1) and is connected to the cavity of the valve sleeve (1).

2. The overflow valve with a guide structure according to claim 1, characterized in that: The valve sleeve (1) has an annular groove on its outer side, and a first O-ring (11) and an elastic retaining ring (12) are sequentially engaged in the annular groove from front to back.

3. The overflow valve with a guide structure according to claim 1, characterized in that: The outer side of the spring seat (3) is provided with an annular groove, and a second O-ring (14) and an open retaining ring (15) are sequentially engaged in the annular groove from front to back.

4. The overflow valve with a guide structure according to claim 1, characterized in that: The set screw (2) is an internal hexagonal flat-end set screw.

5. The overflow valve with a guide structure according to claim 1, characterized in that: A filter screen base (7) is installed at the inlet of the valve sleeve (1) by means of a snap-fit.

6. The overflow valve with a guide structure according to claim 5, characterized in that: The filter base (7) and the filter plug (8) are interference-fitted.

7. The overflow valve with a guide structure according to claim 1, characterized in that: The guide gap between the cone valve core (5) and the spring seat A (6) and the spring seat B (4) is 0.03 to 0.13 mm.

8. The overflow valve with a guide structure according to claim 1, characterized in that: The guide cavity of the spring seat A (6), the guide cavity of the spring seat B (4), and the cavity of the valve sleeve (1) are all coaxially arranged.

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