Threaded cartridge overflow valve

Abstract

The utility model discloses a threaded plug-in mounting overflow valve, relates to the technical field of overflow valves, and is mainly used for solving the problem that most of the existing threaded plug-in mounting overflow valves are of direct-acting structures, so that the leakage rate is large. The valve body and the valve sleeve are coaxially and sequentially connected, a spring assembly is arranged in the valve body, a spring adjusting assembly is arranged on the valve body, a valve seat which can float in the axial direction of the valve sleeve and is internally provided with a medium flow channel is connected to the end, away from the valve body, of the valve sleeve in an inserted mode, a valve element is further arranged in the valve sleeve, and one end of the valve element abuts against the spring assembly. And the other end is in contact sealing fit with the end surface of the valve seat. The utility model provides a threaded plug-in overflow valve, which adopts a floating valve seat design, can form effective linear sealing with a valve core, and has the characteristics of ultralow leakage sealing requirement and low manufacturing cost.

Description

Technical Field

[0001] The utility model relates to the technical field of overflow valves, in particular to a threaded plug-in overflow valve. Background Art

[0002] The overflow valve is an essential pressure control element in the hydraulic system. It is normally closed under normal circumstances, but when the medium pressure in the hydraulic system exceeds the limit value, the overflow valve will open, thereby discharging the medium outside the system to prevent the medium pressure in the system from exceeding the limit value. The overflow valve has different uses in different occasions. Depending on the actual use, it can be used as a constant pressure valve, safety valve, unloading valve and back pressure valve.

[0003] As hydraulic systems develop towards miniaturization, threaded cartridge relief valves have been widely used due to their small size and flexible application. Regarding threaded cartridge relief valves, the maximum pressure set for the hydraulic system pipeline is controlled by the pressure regulating spring in the threaded cartridge relief valve - when the hydraulic pressure at one end of the valve core is greater than the spring force generated by the pressure regulating spring, the valve port will open, and then part of the medium in the pipeline will be discharged to prevent the pressure in the pipeline from continuing to rise. The maximum pressure that can be tolerated in the hydraulic system pipeline is the discharge pressure set by the threaded cartridge relief valve.

[0004] However, most of the threaded cartridge relief valves currently used in the market are direct-acting structures, which have the defects of large pressure regulation deviation, large leakage, and small pressure regulation range that cannot meet the needs of high pressure and large flow. Utility Model Content

[0005] The utility model aims to provide a threaded cartridge relief valve, which adopts a floating valve seat design and can form an effective line seal with a valve core, achieving ultra-low leakage sealing requirements and low manufacturing cost.

[0006] The utility model provides a technical solution for solving the above technical problems: a threaded plug-in relief valve, comprising a valve body and a valve sleeve coaxially connected in sequence, the valve body being provided with a spring assembly capable of extending and retracting along its axial direction, the end of the valve body away from the valve sleeve being provided with a spring adjustment assembly capable of adjusting the pre-compression amount of the spring assembly, the end of the valve sleeve away from the valve body being provided with a valve seat capable of floating along the axial direction of the valve sleeve and provided with a medium flow channel, the valve sleeve being provided with a valve core which is axially slidably sealed with its inner wall, one end of the valve core being in contact with the spring assembly, and the other end being in contact and sealing with the end face of the valve seat.

[0007] As a further improvement of the present invention, the spring assembly includes two spring seats arranged opposite to each other along the axial direction of the valve body, and the opposite sides of the two spring seats are respectively abutted against the spring adjustment assembly and the valve core, and a small spring is provided between the two spring seats, and a large spring with its two ends respectively abutted against the two spring seats is also sleeved outside the small spring.

[0008] As a further improvement of the present invention, the rotation direction of the small spring is opposite to that of the large spring.

[0009] As a further improvement of the present invention, the spring seat and the spring adjustment assembly, as well as the spring seat and the valve core are indirectly connected via a steel ball, and steel ball grooves for installing steel balls are provided on the opposite back surfaces of the two spring seats.

[0010] As a further improvement of the present invention, the spring adjustment assembly includes an adjustment screw that passes through the valve body along the axial direction of the valve body, and one end of the adjustment screw located in the valve body is in contact with the spring assembly.

[0011] As a further improvement of the present invention, the adjustment assembly further comprises a locking nut fixedly mounted on the end surface of the valve body, and the adjustment screw and the locking nut are threadedly connected and matched.

[0012] As a further improvement of the utility model, the valve seat is installed in the valve sleeve in a floating manner through a retaining spring sleeved on its outer wall, and grooves for installing the retaining spring are correspondingly provided on the outer wall of the valve seat and the inner wall of the valve sleeve.

[0013] As a further improvement of the present invention, the outer edge of one end of the valve seat in contact with the valve core is an arc surface, and the valve core is provided with a concave surface on the contact surface with the valve seat, and the inner edge of the opening of the concave surface is in contact and sealing cooperation with the arc surface.

[0014] As a further improvement of the utility model, the area of ​​the concave surface is larger than the end surface area of ​​the valve core close to the spring assembly, and the bottom of the concave surface is provided with a drainage channel extending along the axial direction of the valve core and connected to the medium flow channel. A drainage hole is provided on the inner wall of the drainage channel, and the output end of the drainage hole is connected to the gap between the spring assembly and the valve core.

[0015] As a further improvement of the present invention, an installation groove arranged around the axis of the valve core is provided on the outer wall of the valve core, and a sealing ring is installed in the installation groove.

[0016] Beneficial Effects

[0017] Compared with the prior art, the threaded cartridge relief valve of the utility model has the following advantages:

[0018] 1. In this overflow valve, since the valve seat is in a floating state in the valve sleeve, when the valve core presses against the valve seat to form a sealing pair under the action of the spring assembly, the floating valve seat will also actively press against the valve core, thereby forming an effective line seal with the valve core to achieve the sealing requirement of ultra-low leakage. At the same time, compared with the traditional sealing pair, which has manufacturing difficulties and high processing costs due to strict requirements on form and position tolerances, the floating sealing pair can make up for the form and position errors caused by parts processing, thereby reducing manufacturing difficulty and cost.

[0019] 2. The overflow valve adopts a double spring design, and the double springs rotate in the left and right directions respectively, which can avoid the spring from getting stuck or stuck during movement; at the same time, the double spring design has lower stiffness than the single spring, which is beneficial to the pressure stabilization accuracy of the overflow valve, thereby reducing the pressure regulation deviation of the valve and making the pressure flow characteristics more stable.

[0020] 3. The valve core works on the differential principle, and the effective area on the right end is larger than that on the left end. The oil pressure acts on the differential area of ​​the valve core and together with the spring force, realizes dynamic balance. Thus, the pressure regulation within a larger pressure range can be achieved by adjusting the pre-compression of the spring, thereby making the pressure regulation range of the relief valve wide and meeting the use requirements of high pressure and large flow.

[0021] The present invention will become more clear through the following description in conjunction with the accompanying drawings, which are used to explain the embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a cross-sectional view of the utility model;

[0024] Figure 2 It is a three-dimensional diagram of the valve seat in the utility model.

[0025] Among them: 1-adjusting screw; 2-locking nut; 3-valve body; 4-spring seat; 41-steel ball; 5-large spring; 6-small spring; 7-valve sleeve; 71-outlet; 8-valve core; 81-sealing ring; 82-drainage channel; 83-drainage hole; 9-valve seat; 91-circlip; 92-medium flow channel. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0027] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; of course, it can also be a mechanical connection or an electrical connection; in addition, it can also be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] Embodiments of the present invention will now be described with reference to the accompanying drawings.

[0029] Example

[0030] The specific implementation of the utility model is as follows Figure 1-2 As shown, a threaded plug-in relief valve comprises a valve body 3 and a valve sleeve 7 which are coaxially connected in sequence and are both tubular structures. A spring assembly which can be extended and retracted along its axial direction is provided in the valve body 3, and a spring adjustment assembly which can adjust the pre-compression amount of the spring assembly is also provided on the end of the valve body 3 away from the valve sleeve 7. Among them, a valve seat 9 which can float along the axial direction of the valve sleeve 7 is inserted on the end of the valve sleeve 7 away from the valve body 3. A medium flow channel 92 which runs through the entire valve seat 9 along its axis is provided in the valve seat 9. A valve core 8 which is axially slidably sealed with the inner wall of the valve sleeve 7 is also provided in the valve sleeve 7. One end of the valve core 8 abuts against the spring assembly, and the other end contacts and seals with the end surface of the valve seat 9. In this embodiment, the end of the medium flow channel 92 away from the valve core 9 is an inlet for the medium to enter the relief valve, and oppositely, an outlet 71 for the medium to be discharged is provided on the side wall of the valve sleeve 7 between the valve core 8 and the valve seat 9.

[0031] When in use, the overflow valve will be installed in the hydraulic system, and the medium in the hydraulic system will flow into the medium flow channel 92 of the overflow valve, and will flow out from the outlet 71 when the pressure is overloaded. The overflow valve can provide an axial thrust to the valve core 8 through the spring assembly, thereby pushing the valve core 8 and the valve seat 9 to form a sealing pair - when the medium pressure is less than the thrust, oil isolation is achieved; when the medium pressure is greater than the thrust, the pressure relief can be opened. Among them, the overflow valve can use the spring adjustment assembly to adjust the change in the pre-compression amount of the spring assembly, thereby adjusting the size of the spring force acting on the valve core 8, and then the overflow pressure of the valve can be adjusted. At the same time, since the valve seat 9 is in a floating state in the valve sleeve 7, when the valve core 8 presses against the valve seat 9 to form a sealing pair under the action of the spring assembly, the floating valve seat 9 will also actively push against the valve core 8, so that it can form an effective seal with the valve core 8 and achieve the sealing requirement of ultra-low leakage. Moreover, compared with the defects of traditional sealing pairs such as manufacturing difficulties and high processing costs caused by strict requirements on form and position tolerances, floating sealing pairs can compensate for the form and position errors caused by parts processing, thereby reducing manufacturing difficulty and cost.

[0032] Regarding the specific structure of the spring assembly, the spring assembly includes two spring seats 4 arranged opposite to each other along the axial direction of the valve body 3. Among them, the opposite sides of the two spring seats 4 are respectively in contact with the spring adjustment assembly and the valve core 8. At the same time, a small spring 6 is provided between the two spring seats 4, and a large spring 5 is sleeved on the outside of the small spring 6, and the two ends are respectively in contact with the two spring seats 4. The rotation direction of the small spring 6 is opposite to that of the large spring 5. In addition, in order to stably install the small spring 6 and the large spring 5, a first boss and a second boss are provided on the surface of the two spring seats 4 for installation, which are respectively plugged and matched with the small spring 6 and the large spring 5.

[0033] The relief valve adopts a double spring design, and the double springs are left-handed and right-handed respectively, which can avoid the small spring 6 and the large spring 5 from getting stuck or stuck during the telescopic movement. At the same time, the double spring design has a lower stiffness than the single spring, which is beneficial to the pressure stabilization accuracy of the relief valve, thereby reducing the pressure regulation deviation of the valve and making the pressure flow characteristics more stable.

[0034] In this embodiment, the spring seat 4 and the spring adjustment assembly, and the spring seat 4 and the valve core 8 are indirectly abutted by a steel ball 41. Steel ball grooves for installing the steel balls 41 are provided on the opposite back surfaces of the two spring seats 4. By providing steel balls between the spring seat 4 and the spring adjustment assembly, and between the spring seat 4 and the valve core 8, the stability of the automatic alignment of the spring assembly and the valve core 8 during the movement can be achieved.

[0035] As for the specific structure of the spring adjustment assembly, the spring adjustment assembly includes an adjustment screw 1 that passes through the valve body 3 along the axial direction of the valve body 3, and one end of the adjustment screw 1 located in the valve body 3 contacts and cooperates with the spring assembly. At the same time, in order to accurately control the feed amount of the adjustment screw 1, the adjustment assembly also includes a locking nut 2 fixedly mounted on the end surface of the valve body 3, and the adjustment screw 1 and the locking nut 2 are threadedly connected.

[0036] In this embodiment, in order to achieve floating installation of the valve seat 8 in the valve sleeve 7, the valve seat 8 is floatingly installed in the valve sleeve 7 by means of a retaining ring 91 sleeved on its outer wall, and grooves for installing the retaining ring 91 are correspondingly provided on the outer wall of the valve seat 8 and the inner wall of the valve sleeve 7.

[0037] In addition, regarding the sealing fit between the valve seat 9 and the valve core 8, the outer edge of one end of the valve seat 9 that contacts the valve core 8 is an arc surface, and the valve core 8 is provided with a concave surface on the contact surface with the valve seat 8, and the inner edge of the opening of the concave surface contacts and seals with the arc surface.

[0038] It should be noted that:

[0039] The area of ​​the concave surface in this embodiment is larger than the end surface area of ​​the valve core 8 near one end of the spring assembly. A drainage channel 82 extending along the axial direction of the valve core 8 and communicating with the medium flow channel 92 is provided at the bottom of the concave surface. A drainage hole 83 is provided on the inner wall of the drainage channel 82. The output end of the drainage hole 83 is communicated with the gap between the spring assembly and the valve core 8. The pressure-introducing hole 83 introduces the pressure at the right end of the valve core 8 into the left end, achieving the effect of equal pressure at both ends of the valve core 8. Therefore, under the setting of the area difference at both ends of the valve core 8, part of the liquid pressure on the right end of the valve core 8 is offset, thereby reducing the design difficulty of the spring assembly at the left end of the valve core 8, reducing the stress of the spring assembly, and increasing the life of the spring assembly. At the same time, the product volume is reduced and the weight is reduced.

[0040] At the same time, in order to ensure the axial sliding sealing cooperation between the valve core 8 and the inner wall of the valve sleeve 7, a mounting groove arranged around the axis of the valve core 8 is provided on the outer wall of the valve core 8, and a sealing ring 8 is installed in the mounting groove.

[0041] The present invention is described above in conjunction with the best embodiments, but the present invention is not limited to the embodiments disclosed above, but should cover various modifications and equivalent combinations based on the essence of the present invention.

Claims

1. A threaded cartridge relief valve, comprising a valve body (3) and a valve sleeve (7) coaxially connected in sequence, wherein the valve body (3) is provided with a spring assembly capable of extending and retracting along its axial direction, and the end of the valve body (3) away from the valve sleeve (7) is also provided with a spring adjustment assembly capable of adjusting the pre-compression amount of the spring assembly, characterized in that: A valve seat (9) capable of floating axially along the valve sleeve (7) and having a medium flow channel (92) therein is inserted at one end of the valve sleeve (7) away from the valve body (3). The valve sleeve (7) is also provided with a valve core (8) that is axially slidably sealed with the inner wall thereof, and one end of the valve core (8) is in contact with the spring assembly, while the other end is in contact and sealed with the end face of the valve seat (9).

2. The threaded cartridge relief valve according to claim 1, characterized in that: The spring assembly comprises two spring seats (4) arranged axially opposite to each other along the valve body (3); the opposite sides of the two spring seats (4) are respectively in contact with the spring adjustment assembly and the valve core (8); a small spring (6) is arranged between the two spring seats (4) with two ends respectively in contact with the two spring seats (4); and a large spring (5) is sleeved outside the small spring (6) with two ends respectively in contact with the two spring seats (4).

3. The threaded cartridge relief valve according to claim 2, characterized in that: The rotation direction of the small spring (6) is opposite to that of the large spring (5).

4. The threaded cartridge relief valve according to claim 2 or 3, characterized in that: The spring seat (4) and the spring adjustment assembly, and the spring seat (4) and the valve core (8) are all indirectly connected via a steel ball (41), and steel ball grooves for installing the steel balls (41) are provided on the opposite back surfaces of the two spring seats (4).

5. The threaded cartridge relief valve according to claim 1 or 2, characterized in that: The spring adjustment assembly comprises an adjustment screw (1) which passes through the valve body (3) axially along the valve body (3); one end of the adjustment screw (1) located inside the valve body (3) is in contact with the spring assembly.

6. The threaded cartridge relief valve according to claim 5, characterized in that: The adjustment assembly further comprises a locking nut (2) fixedly mounted on the end surface of the valve body (3), and the adjustment screw (1) and the locking nut (2) are threadedly connected.

7. The threaded cartridge relief valve according to claim 1, characterized in that: The valve seat is installed in a floating manner in the valve sleeve (7) via a retaining ring (91) sleeved on its outer wall. The outer wall of the valve seat and the inner wall of the valve sleeve (7) are both provided with corresponding grooves for installing the retaining ring (91).

8. The threaded cartridge relief valve according to claim 1 or 7, characterized in that: The outer edge of one end of the valve seat (9) in contact with the valve core (8) is an arc surface, and the valve core (8) is provided with a concave surface on the contact surface with the valve seat, and the inner edge of the opening of the concave surface is in contact and sealing cooperation with the arc surface.

9. The threaded cartridge relief valve according to claim 8, characterized in that: The area of ​​the concave surface is larger than the end surface area of ​​the valve core (8) close to the spring assembly. The bottom of the concave surface is provided with a drainage channel (82) extending along the axial direction of the valve core (8) and connected to the medium flow channel (92). The inner wall of the drainage channel (82) is provided with a drainage hole (83). The output end of the drainage hole (83) is connected to the gap between the spring assembly and the valve core (8).

10. The threaded cartridge relief valve according to claim 1, characterized in that: The outer wall of the valve core (8) is provided with a mounting groove arranged around its axis, and a sealing ring is installed in the mounting groove.

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