Cartridge type low flow relief valve with u-channel spring cup

Abstract

The application provides a plug-in type small-flow overflow valve with a U-shaped groove spring cover, which comprises a valve body, a U-shaped groove spring cover, a spring and a plane sealing valve core; the valve body is in a cylindrical structure with an inner hole, and a chamfer, a middle hole, a valve seat hole and a throttling hole are sequentially formed along the axial direction of the inner hole; a ring groove is formed in the middle lower part of the middle hole; an interference fit structure is formed on the outer surface of the valve body; four U-shaped grooves are formed in the circumferential direction of the lower half of the U-shaped groove spring cover and arranged in the middle hole, and the ring groove limits the U-shaped groove spring cover; the plane sealing valve core is arranged in the middle hole; the spring is arranged between the U-shaped groove spring cover and the plane sealing valve core; and the diameter of the throttling hole is less than 0.5 mm. The plug-in type small-flow overflow valve with the U-shaped groove spring cover has a simple and compact structure, does not need to be assembled by threads, can simplify the overall structure of a hydraulic pump system, effectively improve the compactness of the small-flow hydraulic pump system and improve the control precision of the small-flow hydraulic system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydraulic control, and particularly relates to a plug-in type small-flow overflow valve with a U-shaped groove spring cover. BACKGROUND

[0002] As a kind of hydraulic control element, the overflow valve is widely used in hydraulic pump systems to realize stable pressure overflow control. For the hydraulic pump systems such as liquid medicine supply pump and urea supply pump with small liquid supply flow, the hydraulic system is usually required to have the technical features of compact structure, small volume, small liquid supply flow, high liquid supply metering precision and the like. Therefore, the overflow valve with compact structure and capable of realizing small-flow control is usually matched with the hydraulic pump system, which can improve the compactness of the system, improve the precision of overflow control, and reduce the overflow return flow, thereby improving the utilization efficiency of the liquid supply flow.

[0003] Please refer to Figures 1-3 Provided is an overflow valve for a small-flow hydraulic pump system, which comprises a valve body 1, a U-shaped groove spring cover 2, a spring 3 and a planar sealing valve core 4. The outer diameter of the lower edge 23 of the U-shaped groove spring cover 2 before assembly is smaller than the inner hole diameter above the groove 17 of the valve body 1 but larger than the inner hole diameter below the groove 17 of the valve body 1, the U-shaped groove spring cover 2 is installed in the inner hole of the valve body 1 in a press-fit manner, and the lower edge 23 of the U-shaped groove spring cover 2 can be extended outward along the horizontal direction on the thrust shoulder 16 and embedded in the annular groove 17 under the combined action of the thrust of the thrust shoulder 16 and the axial press-fit pressure to realize installation positioning.

[0004] The overflow valve product adopting the technical scheme needs to realize assembly positioning through press fitting. Since the wall thickness of the U-shaped groove spring cover 2 is relatively thin, the U-shaped groove spring cover 2 may be deformed due to excessive press-fit force or cannot be press fitted in place due to insufficient press-fit force during press fitting, which makes the assembly operation of the U-shaped groove spring cover more complex and has a certain risk of assembly failure. In addition, in order to realize press-fit assembly of the U-shaped groove spring cover 2, the inner holes with different diameters need to be machined above and below the annular groove 17 of the valve body 1 to form the thrust shoulder 16, which also increases the structural complexity and manufacturing cost of the valve body 1.

[0005] To solve the above technical problems, a small-flow overflow valve needs to be designed, which can reduce the assembly complexity and difficulty of the U-shaped groove spring cover, eliminate the failure risk caused by the U-shaped groove spring cover during press-fit assembly, thereby improving the assembly qualification rate of the small-flow overflow valve product, reducing the production and manufacturing cost of the overflow valve, and improving the production benefit of the product. SUMMARY

[0006] In view of the above deficiencies in the prior art, the present application provides a plug-in type small flow overflow valve with a U-shaped groove spring cover, which can achieve overflow control of small return flow, reduce the complexity and difficulty of assembly operation of the U-shaped groove spring cover, eliminate the failure risk of the U-shaped groove spring cover caused by press-fit installation, improve the assembly qualification rate of the overflow valve product, reduce the manufacturing cost of the overflow valve, thereby improving the production efficiency of the product; meanwhile, the structure of the valve body can be simplified, which is also conducive to reducing the structural complexity and processing cost of the valve body and the overflow valve assembly.

[0007] To achieve the above-mentioned purpose, the present application provides a plug-in type small flow overflow valve with a U-shaped groove spring cover, which comprises a valve body, a U-shaped groove spring cover, a spring and a planar sealing spool; the valve body is in a cylindrical structure with an inner hole, a chamfer, a middle hole, a valve seat hole and a throttling hole are formed in the valve body along the axial direction of the inner hole, and a ring groove is formed in the middle and lower part of the middle hole; an interference fit structure is formed on the outer surface of the valve body; the U-shaped groove spring cover is cylindrical and open at the lower end; a spring mounting hole is formed in the U-shaped groove spring cover along the axial direction, the top end of the spring mounting hole forms a return hole, and four U-shaped grooves open at the lower end are uniformly distributed in the circumferential direction of the middle and lower segments of the U-shaped groove spring cover, and the lower end of the U-shaped groove spring cover extends outward to form four scallop-shaped edges, and the outer side of the edges forms an edge chamfer; the planar sealing spool comprises a guide cylinder and a spool guide segment connected below the guide cylinder; a spring seat surface is formed on the upper end of the spool guide segment, a circular sealing plane is formed on the lower end surface of the spool guide segment, and three semicircular grooves are uniformly distributed in the circumferential direction of the side surface of the spool guide segment; the U-shaped groove spring cover is arranged in the middle hole and the ring groove limits the edge; the planar sealing spool is arranged in the middle hole and below the U-shaped groove spring cover; the spring is mounted in the spring mounting hole and is pressed between the U-shaped groove spring cover and the planar sealing spool; the diameter of the throttling hole is less than 0.5 mm.

[0008] Preferably, the outer diameter of the edge of the U-shaped groove spring cover is greater than the inner diameter of the middle hole but less than the diameter of the ring groove.

[0009] Preferably, a sealing boss is formed on the periphery of the valve seat hole, and a sealing ring belt is formed on the upper end surface of the sealing boss; the circular sealing plane is in sealing cooperation with the sealing ring belt, and the diameter of the circular sealing plane is greater than the outer diameter of the sealing ring belt.

[0010] Preferably, the interference fit structure comprises an annular shoulder and an annular protrusion, the annular shoulder is formed above the outer wall of the valve body; the annular protrusion is formed below the outer wall of the valve body; the annular shoulder and the annular protrusion are in interference sealing cooperation with the groove formed in the inner wall of an overflow valve mounting hole.

[0011] Preferably, the thickness of the U-shaped groove spring cover is less than 0.5 mm; and the part bottom surface of the rim limits the flat sealing spool.

[0012] Preferably, the hole diameter of the liquid return hole is less than the inner diameter of the spring, and the hole diameter of the liquid return hole is more than twice the diameter of the throttling hole.

[0013] Preferably, the diameter of the semicircular groove is greater than the diameter of the throttling hole.

[0014] Preferably, the maximum outer diameter of the plug-in type small flow overflow valve with a U-shaped groove spring cover is less than 8.0 mm.

[0015] The present application has the following beneficial effects due to the adoption of the above technical solutions:

[0016] The present application provides a plug-in type small flow overflow valve with a U-shaped groove spring cover, which is provided with a throttling hole with a diameter less than 0.5 mm on the valve body, so as to realize the control of small flow overflow liquid return; the lower half of the U-shaped groove spring cover of the overflow valve is provided with four U-shaped grooves uniformly distributed in the circumferential direction, and the lower end is provided with four fan-shaped rims uniformly distributed in the circumferential direction; during assembly, the fan-shaped rims of the U-shaped groove spring cover can be contracted radially inward by using the U-shaped grooves, so as to be installed into the ring groove position of the hole in the valve body, and can be automatically opened and embedded into the ring groove to realize installation and positioning when the fan-shaped rims reach the ring groove position. By using the U-shaped groove spring cover provided by the present application, the assembly operation complexity and difficulty of the spring cover of the existing small flow overflow valve product can be reduced, the risk of deformation or failure of the spring cover caused by press-fitting assembly can be eliminated, the assembly qualification rate of the overflow valve product can be improved, the manufacturing cost can be reduced, and the product benefit can be improved. At the same time, by using the U-shaped groove spring cover provided by the present application, the thrust shoulder formed by machining two inner holes with different diameters on the valve body ring groove can be cancelled, only one inner hole needs to be machined, the structure of the valve body can be simplified, and the machining and manufacturing cost of the valve body and the overflow valve assembly can be reduced. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a cross-sectional view of the small flow overflow valve assembly in the prior art;

[0018] Figure 2 is a cross-sectional view of the small flow overflow valve body in the prior art;

[0019] Figure 3 is a cross-sectional view of the small flow overflow valve spring cover before assembly in the prior art;

[0020] Figure 4 is a cross-sectional view of the small flow overflow valve spring cover after assembly in the prior art;

[0021] Figure 5 A cross-sectional view of the plug-in type small flow relief valve with U-shaped groove spring cover according to an embodiment of the present application;

[0022] Figure 6 A cross-sectional view of the valve body according to an embodiment of the present application;

[0023] Figure 7 A perspective view of the U-shaped groove spring cover according to an embodiment of the present application;

[0024] Figure 8 A cross-sectional view of the U-shaped groove spring cover according to an embodiment of the present application;

[0025] Figure 9 A top view of the U-shaped groove spring cover according to an embodiment of the present application;

[0026] Figure 10 A front view of the flat sealing valve core according to an embodiment of the present application;

[0027] Figure 11 A top view of the flat sealing valve core according to an embodiment of the present application;

[0028] Figure 12 An application example diagram of the plug-in type small flow relief valve with U-shaped groove spring cover according to an embodiment of the present application. DETAILED DESCRIPTION

[0029] The preferred embodiments of the present application are described below in detail with reference to the accompanying drawings Figures 5-12 , so that the functions and characteristics of the present application can be better understood.

[0030] Please refer to Figures 5-12The small flow overflow valve with U-shaped groove spring cover comprises a valve body 1, a U-shaped groove spring cover 2, a spring 3 and a planar sealing valve core 4; the valve body 1 is in a cylindrical structure with an inner hole, and a chamfer 11, a middle hole 12, a valve seat hole 14 and a throttling hole 15 are sequentially formed in the axial direction of the inner hole; a ring groove 13 is formed in the middle and lower part of the middle hole 12; an interference insertion structure is formed on the outer surface of the valve body 1; the U-shaped groove spring cover 2 is in a cylindrical structure with an open lower end; a spring mounting hole 21 is formed in the axial direction inside the U-shaped groove spring cover 2, and a return hole 22 is formed at the top end of the spring mounting hole 21; four U-shaped grooves 23 with open lower ends are uniformly distributed in the circumferential direction of the middle and lower segments of the U-shaped groove spring cover 2; the lower end of the U-shaped groove spring cover 2 extends outward to form four scallop-shaped edges 24, and an edge chamfer 25 is formed on the outer side of each edge 24; the planar sealing valve core 4 comprises a guide cylinder 41 and a valve core guide segment 42 connected below the guide cylinder 41; a spring seat surface 43 is formed at the upper end of the valve core guide segment 42; a circular sealing plane 44 is formed on the lower end surface of the valve core guide segment 42; three semicircular grooves 45 are uniformly distributed in the circumferential direction of the side surface of the valve core guide segment 42; the U-shaped groove spring cover 2 is arranged in the middle hole 12 and limited by the ring groove 13 and the edges 24; the planar sealing valve core 4 is arranged in the middle hole 12 below the U-shaped groove spring cover 2; the spring 3 is mounted in the spring mounting hole 21 and pressed between the U-shaped groove spring cover 2 and the planar sealing valve core 4; the diameter of the throttling hole 15 is less than 0.5 mm.

[0031] The outer diameter of the edge 24 of the U-shaped groove spring cover 2 is greater than the inner diameter of the middle hole 12 but less than the diameter of the ring groove 13.

[0032] A sealing boss 16 is formed on the periphery of the valve seat hole 14, and a sealing ring 17 is formed on the upper end surface of the sealing boss 16; the circular sealing plane 44 is in sealing cooperation with the sealing ring 17, and the diameter of the circular sealing plane 44 is greater than the outer diameter of the sealing ring 17.

[0033] The interference insertion structure comprises an annular shoulder 101 and an annular protrusion 102; the annular shoulder 101 is formed above the outer wall of the valve body 1; the annular protrusion 102 is formed below the outer wall of the valve body 1; the annular shoulder 101 and the annular protrusion 102 are in interference sealing cooperation with the groove formed on the inner wall of the overflow valve mounting hole.

[0034] The thickness of the U-shaped groove spring cover 2 is less than 0.5 mm, so that the small flow overflow control can be realized; part of the bottom surface of the edge 24 limits the planar sealing valve core 4.

[0035] The hole diameter of the return hole 22 is less than the inner diameter of the spring 3, and the hole diameter of the return hole 22 is more than twice the diameter of the throttling hole 15.

[0036] The diameter of the semicircular groove 45 is greater than the diameter of the throttling hole 15.

[0037] The maximum outer diameter of the plug-in type small flow overflow valve with the U-shaped groove spring cover 2 is less than 8.0 mm.

[0038] The outer diameter of the edge 24 of the U-shaped groove spring cover 2 is greater than the inner diameter of the hole 12 in the valve body 1 but less than the diameter of the ring groove 13 of the valve body 1; the sector edge 24 of the U-shaped groove spring cover 2 can be radially inwardly contracted by the U-shaped groove; the edge chamfer 25 of the U-shaped groove spring cover 2 is used to provide a guiding effect for the inward contraction of the edge 24, while avoiding scratching the inner wall of the hole 12 during assembly; the edge 24 of the U-shaped groove spring cover 2 can be radially inwardly contracted and pressed into the hole 12 of the valve body 1 under the joint guiding effect of the chamfer 11 of the valve body 1 and the edge chamfer 25 of the U-shaped groove spring cover 2, and can be automatically opened and embedded in the ring groove 13 after reaching the position of the ring groove 13 of the valve body 1 to achieve installation positioning; the edge 24 of the U-shaped groove spring cover 2 can provide maximum lift limiting for the flat sealing spool 4.

[0039] The annular shoulder 101 and the annular protrusion 102 of the valve body 1 are used to ensure the interference fit between the overflow valve and the overflow valve mounting hole, which can ensure the gap sealing between the overflow valve and the overflow valve mounting hole while achieving the installation positioning of the overflow valve.

[0040] The flat sealing spool 4 is installed in the hole 12 of the valve body 1 and guided by the hole 12. The circular sealing plane 44 of the flat sealing spool 4 cooperates with the sealing ring belt 17 of the valve body 1 to achieve flat sealing, and the diameter of the circular sealing plane 44 is greater than the outer diameter of the sealing ring belt 17. The diameter of the semicircular groove 45 is greater than the diameter of the throttling hole 15 to ensure sufficient overflow flow area. The flat sealing spool 4 is limited by the sealing boss 16 of the valve body 1 when seated, and the sector edge 24 of the U-shaped groove spring cover 2 limits the maximum lift when opened.

[0041] The spring 3 is installed in the spring mounting hole 21, the upper end of the spring 3 is limited by the U-shaped groove spring cover 2 and guided by the spring mounting hole 21, and the lower end of the spring 3 is limited by the spring bearing surface 43 of the flat sealing spool 4 and guided by the guide cylinder 41.

[0042] After the assembly of each component of the overflow valve, the overall overflow valve assembly 5 independent of the hydraulic pump is formed, the outer diameter of the overflow valve assembly 5 is less than 8.0 mm, and the overflow valve assembly 5 can be directly interference-fitted and pressed into the overflow valve mounting hole of the hydraulic pump 6, and the return line 7 of the hydraulic pump 6 can be connected to the return line of the hydraulic pump 6 in the return line direction of the overflow valve assembly 5.

[0043] The working principle of the overflow valve assembly 5 is as follows: when the back pressure at the back liquid outlet of the hydraulic pump 6 is lower than the opening pressure of the overflow valve assembly 5 under the action of the spring 3, the flat sealing spool 4 remains seated, the circular sealing plane 44 cooperates with the sealing ring belt 17, the valve seat hole 14 is kept sealed, and the hydraulic pump 6 does not back liquid; when the back pressure at the back liquid outlet of the hydraulic pump 6 is higher than the opening pressure of the overflow valve assembly 5 under the action of the spring 3, the flat sealing spool 4 rises under the action of the back pressure, the valve seat hole 14 is opened, and the excess hydraulic working medium in the hydraulic pump 6 overflows through the overflow valve assembly 5 and is back-flushed through the back liquid pipeline 7.

[0044] The plug-in type small flow overflow valve with the U-shaped groove spring cover of the embodiment of the present application is provided with a throttle hole 15 with a diameter less than 0.5 mm on the valve body 1, and can realize small flow overflow back-flushing control and ensure the control accuracy of the hydraulic pump system to small flow back-flushing. The lower half of the U-shaped groove spring cover 2 of the overflow valve is provided with four circumferentially distributed U-shaped grooves, so that the lower end of the U-shaped spring cover can be radially inwardly retracted. The lower end of the U-shaped groove spring cover 2 is provided with four circumferentially distributed sector edges 24, which will be guided by the chamfer 11 of the valve body 1 during assembly, and will be radially inwardly retracted by the U-shaped groove under the combined guidance of the chamfer 11 of the valve body 1 and the chamfer 25 of the edge of the U-shaped groove spring cover 2, enter the hole 12 of the valve body 1 and reach the position of the annular groove 13 of the valve body 1, and can be automatically opened and embedded in the annular groove 13 after the sector edge 24 of the U-shaped groove spring cover 2 reaches the position of the annular groove 13 of the valve body 1, so as to realize the installation and positioning of the U-shaped groove spring cover 2. The plug-in type small flow overflow valve with the U-shaped groove spring cover provided by the present application can reduce the assembly operation complexity and difficulty of the spring cover of the existing small flow overflow valve product, eliminate the failure risk of deformation or failure to be assembled in place of the spring cover due to press-fitting assembly, improve the assembly qualification rate of the overflow valve, reduce the manufacturing cost, and improve the product benefit. In addition, by using the U-shaped groove spring cover 2 provided by the present application, only one inner hole needs to be machined on the valve body 1, and the structure of the existing small overflow valve product which needs to machine inner holes with different diameters on the upper and lower annular grooves 13 of the valve body 1 to form a thrust shoulder can be cancelled, the structure of the valve body 1 can be further simplified, and the machining and manufacturing cost of the valve body 1 and the overflow valve assembly can be reduced, and the product benefit can be improved.

[0045] The above embodiments of the present application are described in detail with reference to the accompanying drawings, and those skilled in the art can make various changes to the present application according to the above description. Therefore, some details in the embodiments should not constitute a limitation on the present application, and the protection scope of the present application will be defined by the appended claims.

Claims

1. A cartridge-type small-flow relief valve with a U-shaped groove spring cover, characterized in that, The valve body (1) comprises a valve body (1), a U-shaped groove spring cover (2), a spring (3), and a flat sealing valve core (4). The valve body (1) has a cylindrical structure with an inner hole. Along the axial direction of the inner hole, the valve body (1) sequentially forms a chamfer (11), a central hole (12), a valve seat hole (14), and a throttling hole (15). An annular groove (13) is formed in the lower middle part of the central hole (12). An interference fit structure is formed on the outer surface of the valve body (1). The U-shaped groove spring cover... (2) It is cylindrical and open at the bottom; a spring mounting hole (21) is formed in the interior of the U-shaped groove spring cover (2) along the axial direction, a return hole (22) is formed at the top of the spring mounting hole (21), four U-shaped grooves (23) with open bottoms are evenly distributed in the middle and lower section of the U-shaped groove spring cover (2) along the circumference, and the lower end of the U-shaped groove spring cover (2) extends outward to form four fan-shaped edges (24), and a chamfer (25) is formed on the outer side of each edge (24); The planar sealing valve core (4) includes a guide cylinder (41) and a valve core guide section (42) connected below the guide cylinder (41); a spring bearing surface (43) is formed at the upper end of the valve core guide section (42), a circular sealing plane (44) is formed at the lower end of the valve core guide section (42), and three semi-circular grooves (45) are evenly distributed along the side of the valve core guide section (42); the U-shaped groove spring cover (2) is disposed in the central hole (12) and the annular groove (13) limits the edge (24); the planar sealing valve core (4) is disposed in the central hole (12) and located below the U-shaped groove spring cover (2); the spring (3) is installed in the spring mounting hole (21) and pressed between the U-shaped groove spring cover (2) and the planar sealing valve core (4); the diameter of the throttling orifice (15) is less than 0.5 mm; The outer diameter of the edge (24) of the U-shaped groove spring cover (2) is larger than the inner diameter of the central hole (12) but smaller than the diameter of the annular groove (13). The fan-shaped edge (24) of the U-shaped groove spring cover (2) tapers radially inward using the U-shaped groove. The chamfer (25) of the edge of the U-shaped groove spring cover (2) is used to provide a guiding effect for the inward taper of the edge (24), while avoiding the edge (24) from scratching the inner wall of the central hole (12) during assembly. The edge (24) of (2) is radially contracted and pressed into the middle hole (12) of the valve body (1) under the combined guidance of the chamfer (11) of the valve body (1) and the chamfer (25) of the edge of the U-shaped groove spring cover (2). After the edge (24) reaches the position of the annular groove (13) of the valve body (1), it automatically opens and is embedded in the annular groove (13) to achieve installation positioning; the edge (24) of the U-shaped groove spring cover (2) provides the maximum lift limit for the planar sealing valve core (4).

2. The cartridge-type small-flow relief valve with a U-shaped groove spring cover according to claim 1, characterized in that, A sealing boss (16) is formed around the valve seat hole (14), and a sealing ring (17) is formed on the upper end face of the sealing boss (16); the circular sealing plane (44) is sealed to the sealing ring (17), and the diameter of the circular sealing plane (44) is larger than the outer diameter of the sealing ring (17).

3. The cartridge-type small-flow relief valve with a U-shaped groove spring cover according to claim 2, characterized in that, The interference fit structure includes an annular shoulder (101) and an annular protrusion (102). The annular shoulder (101) is formed on the upper part of the outer wall of the valve body (1). The annular protrusion (102) is formed on the lower part of the outer wall of the valve body (1). The annular shoulder (101) and the annular protrusion (102) are interference-sealed with a groove opened on the inner wall of an overflow valve mounting hole.

4. The cartridge-type small-flow relief valve with a U-shaped groove spring cover according to claim 3, characterized in that, The thickness of the U-shaped groove spring cover (2) is less than 0.5 mm; the bottom part of the edge (24) limits the planar sealing valve core (4).

5. The cartridge-type small-flow relief valve with a U-shaped groove spring cover according to claim 4, characterized in that, The diameter of the return hole (22) is smaller than the inner diameter of the spring (3), and the diameter of the return hole (22) is more than twice the diameter of the throttling hole (15).

6. The cartridge-type small-flow relief valve with a U-shaped groove spring cover according to claim 5, characterized in that, The diameter of the semi-circular groove (45) is larger than the diameter of the throttling orifice (15).

7. The cartridge-type small-flow relief valve with a U-shaped groove spring cover according to claim 6, characterized in that, The maximum outer diameter of the cartridge-type small-flow relief valve with a U-shaped groove spring cover is less than 8.0 mm.

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