CN219529431U - Overflow valve - Google Patents

Abstract

The utility model relates to the technical field of hydraulic pressure, in particular to an overflow valve. An overflow valve, comprising: the valve seat is provided with a radial oil hole; the valve core penetrates through the valve seat, and under the action of the first elastic piece, the first end of the valve core is abutted against the opening of the valve seat to form a seal; the pilot assembly comprises a pilot valve core and a pilot valve sleeve, the pilot valve core is slidably assembled in the pilot valve sleeve, the pilot valve core acts on the second end of the valve core through a second elastic piece, and the position of the pilot valve sleeve is adjustable. The inner peripheral surface of the pilot valve sleeve is provided with a stepped surface, the outer diameter of the pilot valve core is changed, and the pilot valve core abuts against the stepped surface to limit the movement range of the pilot valve core towards the valve core. The technical problem that the opening pressure of the overflow valve in the prior art is inconvenient to adjust is solved.

Description

Overflow valve

Technical Field

The utility model relates to the technical field of hydraulic pressure, in particular to an overflow valve.

Background

In the prior art, the overflow valve with the oil supplementing function is commonly used for an A/B oil port of the multi-way valve, can limit the maximum pressure of the A/B port, can be reversely opened when the A/B port is empty, and has the oil supplementing function.

As shown in fig. 1, the overflow valve with oil supplementing function in the prior art comprises a valve seat 1' and a valve core 2', wherein the valve core 2' is slidably assembled in the valve seat 1', a first end part of the valve core 2' is matched with the valve seat 1', a second end part of the valve core 2' extends out of the valve seat 1' and is provided with a spring seat 3', a spring 4' is sleeved outside the valve core 2' and the valve seat 1', one end of the spring 4' is abutted against the valve seat 1', the other end is abutted against the spring seat 3', the first end of the valve core 2' is abutted against the end part of the valve seat 1' under the action of the spring 4', and the second end of the valve core 2' is elastically abutted against a blocking piece 6' through a conical spring 5 '; when the valve is assembled, the first end of the valve core 2 'extends into the valve block, the blocking piece 6' can be assembled on the valve block in a threaded manner, and high-pressure oil flows in from the first oil port; the low pressure oil flows in from the second oil port and acts on the first end face of the valve core 2'.

When in overflow working condition, the valve seat 1 'is arranged in the jack, and the valve body supports the valve seat 1' to limit the movement of the valve seat; when the first oil port is filled with high-pressure oil, the lower end of the spring 4' is supported on the valve seat 1' and does not move, the high-pressure oil enters the upper part of the conical spring 5', acts on the valve core 2' and the spring seat 3', and the high-pressure oil compresses the spring 4' to enable the valve core 2' to move downwards. When the pressure of the first oil port is lower than the set value of the spring 4', the valve core 2' cannot be opened, and the locking state is kept; when the pressure of the first oil port is larger than or equal to the set pressure of the spring 4', the conical surface of the valve core 2' leaves the sealing sharp edge of the valve seat, the overflow valve is opened, and high-pressure oil of the first oil port flows out of the overflow through the radial hole of the valve seat, so that the overflow function is realized.

Oil supplementing working condition: when the pressure of the first oil port is reduced to be lower than the pressure of the second oil port due to suction, the valve core 2 'is tightly pressed on the valve seat 1' under the action of the spring 4', the valve core 2' and the valve seat 1 'are connected into a whole to move together, and the whole valve core 2' and the valve seat 1 'are only acted by the pressure of the second oil port and the upper conical spring 5'; at this time, the pressure of the second oil port acts on the valve core 2' and the valve seat 1', as long as the pressure difference between the second oil port and the first oil port acts on the hydraulic pressure of the integrated structure of the valve core 2' and the valve seat 1' and is larger than the conical spring force, the valve seat 1' moves upwards, and the oil of the second oil port can flow to the first oil port to realize the oil supplementing function after leaving the valve body.

From the above, it is known that the relief pressure of the relief valve is closely related to the spring during relief, and the force of the valve core against the sealing sharp edge of the valve seat is also provided by the spring, so that the opening pressure of the relief valve is inconvenient to adjust.

Disclosure of Invention

In order to solve the technical problem that the opening pressure of an overflow valve in the prior art is inconvenient to adjust, the utility model provides the overflow valve, and solves the technical problem. The technical scheme of the utility model is as follows:

an overflow valve, comprising:

the valve seat is provided with a radial oil hole;

the valve core penetrates through the valve seat, and under the action of the first elastic piece, the first end of the valve core is abutted against the opening of the valve seat to form a seal;

the pilot assembly comprises a pilot valve core and a pilot valve sleeve, the pilot valve core is slidably assembled in the pilot valve sleeve, the pilot valve core acts on the second end of the valve core through a second elastic piece, and the position of the pilot valve sleeve is adjustable.

According to the overflow valve, the opening pressure of the overflow valve is adjusted by adopting the structure of the pilot assembly, the pilot valve core is slidably assembled in the pilot valve sleeve, the pilot valve core slides towards the valve core in the pilot valve sleeve, the pilot valve core provides acting force opposite to the acting direction of the first elastic piece for the valve core through the second elastic piece, and when overflow occurs, the opening pressure of the valve core is the difference value of the elastic forces of the first elastic piece and the second elastic piece acting on the valve core; the position of the pilot valve sleeve is adjustable, so that the control of the moving range of the pilot valve core can be realized by controlling the position of the pilot valve sleeve, the acting force range of the second elastic piece on the valve core can be further controlled, and the opening pressure of the valve core can be regulated.

According to one embodiment of the utility model, the inner peripheral surface of the pilot valve sleeve is formed with a stepped surface against which the pilot valve spool outer diameter varies to define its range of movement toward the spool.

According to one embodiment of the utility model, the pilot valve sleeve is provided with an air hole, one end of the air hole extends to the outer peripheral surface of the pilot valve sleeve, and the other end of the air hole extends to the inner peripheral surface of the pilot valve sleeve and is close to the step surface.

According to one embodiment of the utility model, an inner flow passage is formed in the pilot valve core, a pilot cavity is formed at one end of the pilot valve core, which is far away from the valve core, and high-pressure oil during overflow flows to the pilot cavity through the inner flow passage.

According to one embodiment of the utility model, it further comprises a mounting sleeve and a valve body, the valve seat, the valve core and the pilot valve sleeve being fitted on the valve body by means of the mounting sleeve.

According to one embodiment of the utility model, an insertion hole is formed in the valve body, a first oil port and a second oil port are also formed in the valve body, the first oil port and the second oil port are both communicated with the insertion hole, and the valve seat and the valve core extend into the insertion hole to control on-off between the first oil port and the second oil port.

According to one embodiment of the utility model, the outer surface of the valve seat is provided with a conical surface, the conical surface of the valve seat can be abutted against the inner wall of the insertion hole to form a seal, the first oil port is positioned at the periphery of the valve core, and the first oil port is connected with high-pressure oil; the second oil port is arranged corresponding to the end face of the first end of the valve core, and the second oil port is connected with low-pressure oil.

According to one embodiment of the utility model, the mounting sleeve comprises a valve sleeve and an adjusting screw sleeve, wherein the valve sleeve is a sleeve body with two open ends, one end of the valve sleeve is assembled on the valve body, the other end of the valve sleeve is connected with the adjusting screw sleeve in a threaded manner, and the pilot valve sleeve is assembled with the adjusting screw sleeve in a follow-up manner.

According to one embodiment of the utility model, a first spring seat is arranged on the valve core, the first elastic piece is positioned on one side, close to the valve seat, of the first spring seat, and two ends of the first elastic piece respectively act on the valve seat and the first spring seat; a third elastic piece is further arranged on the other side of the first spring seat and acts on the first spring seat; the second end of the valve core is provided with a second spring seat, the end part, close to the valve core, of the pilot valve core is provided with a third spring seat, and two ends of the second elastic piece respectively act on the second spring seat and the third spring seat.

According to one embodiment of the utility model, the valve further comprises a fourth elastic piece, wherein the fourth elastic piece is sleeved on the periphery of the second elastic piece, and the fourth elastic piece provides a reset acting force for the pilot valve core.

Based on the technical scheme, the utility model has the following technical effects:

1. according to the overflow valve, the opening pressure of the overflow valve is adjusted by adopting the structure of the pilot assembly, the pilot valve core is slidably assembled in the pilot valve sleeve, the pilot valve core slides towards the valve core in the pilot valve sleeve, the pilot valve core provides acting force opposite to the acting direction of the first elastic piece for the valve core through the second elastic piece, and when overflow occurs, the opening pressure of the valve core is the difference value of the elastic forces of the first elastic piece and the second elastic piece acting on the valve core; the position of the pilot valve sleeve is adjustable, so that the control of the moving range of the pilot valve core can be realized by controlling the position of the pilot valve sleeve, the acting force range of the second elastic piece on the valve core can be further controlled, and the opening pressure of the valve core can be regulated;

2. according to the overflow valve, the sliding range of the pilot valve core in the pilot valve sleeve can be limited by the pilot valve sleeve through the stepped surface; the high-pressure oil during overflow can flow into the pilot cavity through the inner flow channel of the pilot valve core to act on the pilot valve core without being additionally connected with the pilot oil, the pilot valve core can be pushed to move to a position propping against the stepped surface under the action of the high-pressure oil during overflow, the pilot valve core acts on the valve core through the second elastic piece, and the opening pressure of the valve core is the difference value of the elastic forces of the first elastic piece and the second elastic piece acting on the valve core; further, in use, the adjusting screw sleeve of the mounting sleeve can rotate to adjust the position of the pilot valve sleeve in the valve sleeve, when overflow occurs, the pilot valve core is propped against the stepped surface of the pilot valve sleeve, and the position of the pilot valve core relative to the valve sleeve is also adjusted, so that the elastic force of the second elastic piece acting on the valve core can be adjusted, and the opening pressure of the valve core is adjusted; the air holes are formed in the pilot valve sleeve, so that the air pressure inside and outside the pilot valve sleeve can be balanced when the pilot valve core slides along the pilot valve sleeve, and the problem of pressure holding does not exist;

3. according to the overflow valve, gaps are reserved between the spring seat and the valve sleeve of the mounting sleeve, so that pressure oil flowing in from the first oil port conveniently flows to the pilot valve core through the gaps and then flows to the pilot cavity through the inner flow path of the pilot valve core, high-pressure oil can act on the pilot valve core, and the pilot valve core acts on the valve core through the second elastic piece; the conical surface of the valve seat can be abutted against the inner wall of the insertion hole to form a seal in the initial state by arranging the third elastic piece; by arranging the fourth elastic piece, the pilot valve core can reset under the action of the fourth elastic piece when oil is replenished, and the valve core is not influenced by the third elastic piece and the fourth elastic piece except the second elastic piece when the oil is replenished, so that the oil replenishing function is not influenced.

Drawings

FIG. 1 is a schematic diagram of a prior art relief valve;

FIG. 2 is a schematic view of the relief valve of the present utility model in an initial closed state;

fig. 3 is an enlarged view of a portion a of fig. 2;

FIG. 4 is a schematic structural view of a valve core;

FIG. 5 is a front view of the valve cartridge;

FIG. 6 is a schematic structural view of a pilot spool;

FIG. 7 is a cross-sectional view of the pilot spool;

FIG. 8 is a schematic structural view of a pilot valve sleeve;

FIG. 9 is a cross-sectional view of the pilot valve sleeve;

FIG. 10 is a schematic view of the construction of the adjustment nut;

FIG. 11 is a cross-sectional view of the adjustment nut;

FIG. 12 is a schematic structural view of a second spring seat;

FIG. 13 is a front view of a second spring seat;

FIG. 14 is a cross-sectional view of a second spring seat;

FIG. 15 is a state diagram of the relief valve when both the valve element and the valve seat, and the valve seat and the valve body are open;

fig. 16 is an enlarged view of a portion B of fig. 15;

in the figure: 1-valve seat; 11-radial oil holes; 12-conical surface; 2-valve core; 21-a first end; 22-a second end; 23-recess; 24-conical sealing surface; 25-first external threads; 31-a first elastic member; 32-a second elastic member; 33-a third elastic member; 34-fourth elastic members; 4-a pilot spool; 41-an inner flow passage; 42-a boss; 5-a pilot valve sleeve; 51-step surface; 52-air holes; 53-second external threads; 6-a valve body; 61-inserting holes; 62-a first oil port; 63-a second oil port; 7, installing a sleeve; 71-valve sleeve; 72-adjusting the screw sleeve; 721-first internal thread; 722-vent holes; 723-limit surface; 724-second internal threads; 81-a first spring seat; 82-a second spring seat; 821-cutting grooves; 822-a conical hole; 83-a third spring seat; 9-locking the nut; 10-a pilot cavity; 1' -valve seat; 2' -valve core; 3' -spring seat; a 4' -spring; a 5' -cone spring; 6' -blocking piece.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the utility model, its application, or uses. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the present utility model. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.

The relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present utility model unless it is specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective parts shown in the drawings are not drawn in actual scale for convenience of description. Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.

In the description of the present utility model, it should be understood that the azimuth or positional relationships indicated by the azimuth terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal", and "top, bottom", etc., are generally based on the azimuth or positional relationships shown in the drawings, merely to facilitate description of the present utility model and simplify the description, and these azimuth terms do not indicate and imply that the apparatus or elements referred to must have a specific azimuth or be constructed and operated in a specific azimuth, and thus should not be construed as limiting the scope of protection of the present utility model; the orientation word "inner and outer" refers to inner and outer relative to the contour of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "upper surface at … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial location relative to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "over" other devices or structures would then be oriented "below" or "beneath" the other devices or structures. Thus, the exemplary term "above … …" may include both orientations of "above … …" and "below … …". The device may also be positioned in other different ways (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

In addition, the terms "first", "second", etc. are used to define the components, and are only for convenience of distinguishing the corresponding components, and the terms have no special meaning unless otherwise stated, and therefore should not be construed as limiting the scope of the present utility model.

As shown in fig. 2-16, the present embodiment provides an overflow valve, which includes a valve seat 1 and a valve core 2, wherein an axial through hole is formed on the valve seat 1, the valve core 2 passes through the axial through hole of the valve seat 1, two ends of the valve core 2 extend out of the valve seat 1, the valve core 2 can slide along the valve seat 1, and under the action of a first elastic member 31, a first end 21 of the valve core 2 can abut against an opening of the axial through hole of the valve seat 1 to form a seal; the valve seat 1 is also provided with the oil hole 11, the oil hole 11 can radially extend, high-pressure oil can flow in from the periphery of the valve seat 1 during overflow, the valve core 2 is pushed to overcome the acting force of the first elastic piece 31, the first end 21 of the valve core 2 is far away from the valve seat 1, sealing is relieved, the high-pressure oil enters the valve seat 1 through the oil hole 11, and then flows out from a gap between the first end of the valve core 2 and the valve seat 1, so that overflow is realized.

An axial through hole is formed in the axial direction of the valve seat 1 so that the valve core 2 can pass through, the valve core 2 is slidably assembled in the valve seat 1, and a plurality of radial oil holes 11 are distributed on the valve seat 1 so that high-pressure oil on the periphery of the valve seat 1 enters the interior of the valve seat 1 through the radial oil holes 11.

When in use, the valve seat 1 is assembled on the valve body 6, the outer surface of the valve seat 1 is required to be abutted against the valve body 6 to form a seal, and in order to ensure the tightness between the valve seat 1 and the valve body 6, the outer surface of the valve seat 1 is formed with a conical surface 12 to form conical surface seal with the valve body 6, so that the tightness is ensured. The tapered surface 12 is closer to the first end 21 of the spool 2 than the radial oil hole 11.

As a preferable technical solution of the present embodiment, the radial oil holes 11 are plural, and the plural radial oil holes 11 are uniformly arranged along the circumferential direction.

The valve core 2 slides through the valve seat 1, the valve core 2 is in a rod-shaped structure, the first end 21 and the second end 22 of the valve core 2 respectively extend out of the valve seat 1, the first end 21 of the valve core 2 is close to the conical surface 12 of the valve seat 1, and under the action of the first elastic piece 31, the first end 21 of the valve core 2 abuts against the opening of the axial through hole of the valve seat 1 to form sealing.

As a preferred technical solution of this embodiment, the valve core 2 has a rod-shaped structure with a variable outer diameter, the outer diameter of the first end 21 of the valve core 2 is larger than the aperture of the axial through hole of the valve seat 1, the first end 21 of the valve core 2 forms a conical sealing surface 24, and under the action of the first elastic member 31, the conical sealing surface 24 of the valve core 2 abuts against the opening of the axial through hole of the valve seat 1 to form a seal.

As a preferable technical scheme of the embodiment, a concave part 23 is formed at a part of the valve core 2 close to the first end 21, the concave part 23 is completely positioned in the valve seat 1 in an initial state, and the concave part 23 is matched with the inner peripheral surface of the valve seat 1 to form an annular cavity; during overflow, high-pressure oil can enter the annular cavity through the oil hole 11, and then flows out of the overflow valve through a gap between the valve core 2 and the valve seat 1, so that overflow is realized.

As a preferable technical solution of the present embodiment, in order to assemble the first elastic member 31, the first spring seat 81 is assembled outside the valve core 2 extending out of the valve seat 1, the first elastic member 31 is sleeved outside the valve core 2, and both ends of the first elastic member 31 act on the valve seat 1 and the first spring seat 81, respectively. Preferably, the first spring seat 81 is assembled at a non-end position of the valve body 2, the first spring seat 81 may be assembled to the valve body 2 in a threaded manner, and the first external thread 25 is formed on the outer circumferential surface of the valve body 2 to be threadedly assembled with the first spring seat 81. Preferably, the outer circumferential surface of the valve seat 1 is formed with a stepped surface to facilitate the abutment of the first elastic member 31 against the valve seat 1.

In order to adjust the opening pressure of the relief valve, a pilot assembly is arranged at one side of the second end 22 of the valve core 2, the pilot assembly comprises a pilot valve core 4 and a pilot valve sleeve 5, the pilot valve core 4 is slidably assembled in the pilot valve sleeve 5, the axial position of the pilot valve sleeve 5 is adjustable, the pilot valve core 4 can act on the second end 22 of the valve core 2, the pilot valve core 4 provides acting force to the valve core 2 in the opposite direction to the first elastic piece 31 through the second elastic piece 32, and the opening pressure of the valve core 2 is the difference value of acting forces of the first elastic piece 31 and the second elastic piece 32. The sliding range of the pilot valve core 4 can be adjusted through the position adjustment of the pilot valve sleeve 5, so that the acting force of the second elastic piece 32 on the valve core 2 is adjusted, and the opening pressure of the valve core 2 is adjusted.

The pilot spool 4 is located at one axial side of the second end 22 of the spool 2, the pilot spool 4 may be located on the same axis as the spool 2, an inner flow channel 41 is formed in the pilot spool 4, a pilot cavity 10 is formed at one side of the pilot spool 4 away from the spool 2, during overflow, part of high-pressure oil can flow into the pilot cavity 10 through the inner flow channel 41 of the pilot spool 4, the high-pressure oil acts on the pilot spool 4 to push the pilot spool 4 to move towards the spool 2, and the pilot spool 4 elastically acts on the spool 2 through the second elastic member 32.

As a preferable embodiment of the present embodiment, the inner flow passage 41 extends axially and penetrates the pilot spool 4.

As a preferable solution of the present embodiment, the area of the end face of the pilot spool 4 near the pilot chamber 10 is larger than the area of the end face of the other end.

As a preferred solution of the present embodiment, the pilot valve element 4 is slidably fitted in the pilot valve sleeve 5, and the pilot valve sleeve 5 may define a sliding range of the pilot valve element 4 inside. Specifically, the outer periphery of the pilot valve element 4 is formed with a protruding portion 42, the inner peripheral surface of the pilot valve sleeve 5 is formed with a stepped surface 51, and when the pilot valve element 4 slides under the action of oil pressure, the protruding portion 42 can abut against the stepped surface 51 to define the sliding position of the pilot valve element 4 in the pilot valve sleeve 5. During overflow, the pilot valve core 4 moves to abut against the stepped surface 51 of the pilot valve sleeve 5 under the action of high-pressure oil, and thus, the position of the pilot valve sleeve 5 is adjusted, so that the position of the pilot valve core 4 during overflow can be controlled.

As a preferable technical solution of this embodiment, in order to ensure smooth sliding of the pilot valve core 4 in the pilot valve sleeve 5, an air hole 52 is further formed on the pilot valve sleeve 5, so as to balance air pressure between the pilot valve sleeve 5 and the pilot valve core 4, and when the pilot valve core 4 moves toward the valve core 2, the pressure is not suppressed, and the action is affected. Further preferably, one end of the air hole 52 extends to the outer peripheral surface of the pilot valve sleeve 5, and the other end extends to near the stepped surface 51.

The second elastic member 32 is located between the valve core 2 and the pilot valve core 4, in order to ensure that the second elastic member 32 provides a stable elastic force, the second end 22 of the valve core 2 is provided with a second spring seat 82, one end of the pilot valve core 4, which is close to the valve core 2, is provided with a third spring seat 83, and two ends of the second elastic member 32 respectively lean against the second spring seat 82 and the third spring seat 83.

As a preferable solution of this embodiment, the second end 22 of the valve core 2 and an end of the pilot valve core 4 near the valve core 2 may be tapered, the second spring seat 82 may be formed with a tapered hole 822, and the third spring seat 83 may be formed with a tapered hole for corresponding insertion. Preferably, a through hole in the axial direction is also formed in the third spring seat 83 to facilitate the entry of high-pressure oil into the inner flow passage 41 of the pilot spool 4.

In use, the valve seat 1, the valve spool 2, the pilot valve spool 4 and the pilot valve sleeve 5 are assembled on the valve body 6 by means of the mounting sleeve 7. The valve body 6 is internally provided with an inserting hole 61, the valve body 6 is internally provided with a first oil port 62 and a second oil port 63, the first oil port 62 and the second oil port 63 are communicated with the inserting hole 61, the first ends 21 of the valve seat 1 and the valve core 2 extend into the inserting hole 61, the conical surface 12 of the valve seat 1 can be abutted against the inner wall of the inserting hole 61 to form sealing, the valve seat 1 and the valve core 2 move under the action of oil pressure of the two oil ports, the on-off of the first oil port 62 and the second oil port 63 can be controlled, and overflow and oil supplement are realized.

As a preferable technical solution of the present embodiment, the first oil port 62 is located in a radial direction of the insertion hole 61, and the first oil port 62 is connected with high-pressure oil; the second oil port 63 is located in the axial direction of the insertion hole 61, and the second oil port 63 is connected to low-pressure oil.

The installation sleeve 7 is used for assembling the valve seat 1, the valve core 2, the pilot valve core 4 and the pilot valve sleeve 5 on the valve body 6, the installation sleeve 7 is a sleeve body with one end open, the installation sleeve 7 is sleeved outside one side where the pilot valve core 4 and the pilot valve sleeve 5 are located, the pilot valve sleeve 5 can be abutted against the inner bottom surface of the installation sleeve 7, and the opening of the installation sleeve 7 can be assembled at the opening of the insertion hole 61 of the valve body 6 in a threaded connection mode.

As a preferred technical scheme of the present embodiment, for convenience in assembly and for adjusting the overflow pressure of the overflow valve, the installation sleeve 7 is configured as a split structure, the installation sleeve 7 includes a valve sleeve 71 and an adjusting screw sleeve 72, the valve sleeve 71 is a sleeve body with two open ends, one end of the valve sleeve 71 extends into the insertion hole 61 and is in threaded connection with the insertion hole 61, and the other end of the valve sleeve 71 is in threaded connection with the adjusting screw sleeve 72.

As a preferable technical scheme of the embodiment, a first internal thread 721 and a second internal thread 724 are arranged on the inner circumferential surface of the adjusting screw sleeve 72, the adjusting screw sleeve 72 is in threaded fit with the valve sleeve 71 through the first internal thread 721, the adjusting screw sleeve 72 is in threaded fit with the pilot valve sleeve 5 through the second internal thread 724, and a second external thread 53 is arranged on the outer circumferential surface of the pilot valve sleeve 5; when the adjusting screw sleeve 72 is rotated, the axial position of the adjusting screw sleeve 72 is also changed, the adjusting screw sleeve 72 drives the pilot valve sleeve 5 to axially move, so that the positions of the pilot valve sleeve 5 and the pilot valve core 4 in the initial state can be adjusted, and the initial precompression amount of the second elastic piece 32 is controlled. After the position of the adjustment screw 72 is adjusted in place, the lock nut 9 can be tightened to lock the adjustment screw 72.

As a preferred solution of this embodiment, the inner circumferential surface of the adjusting screw sleeve 72 is further provided with a limiting surface 723, and the limiting surface 723 is located between the first internal thread 721 and the second internal thread 724, so that the movement range of the adjusting screw sleeve 72 on the valve sleeve 71 can be limited by abutting the end surface of the valve sleeve 71 against the limiting surface 723.

As a preferable solution of this embodiment, the adjusting screw sleeve 72 is further provided with a vent hole 722, and the gas discharged from the air hole 52 can be discharged to the outside of the mounting sleeve 7 through the vent hole 722. Specifically, the inner end of the vent 722 extends to the stop surface 723 and the outer end of the vent 722 extends to the outer surface of the adjustment screw sleeve 72. The air holes 52 may be provided as inclined holes, and the outer ends of the air holes 52 extend to a position close to the end face of the valve sleeve 71, thus ensuring that the air flow passage is always unobstructed.

In order to ensure that the valve seat 1 is kept against the inner wall of the insertion hole 61 to form a seal in the initial state, a third elastic member 33 is further provided, the third elastic member 33 is sleeved on the valve core 2, one end of the third elastic member 33 acts on the valve sleeve 71, and the other end acts on the first spring seat 81.

In order to ensure the return of the pilot valve element 4 in the oil-compensating condition, a fourth elastic member 34 is further disposed in the valve sleeve 71, one end of the fourth elastic member 34 abuts against the inner wall of the valve sleeve 71, and the other end abuts against the third spring seat 83.

As a preferred technical solution of the present embodiment, in order to facilitate the high-pressure oil entering through the first oil port 62 entering into the pilot cavity 10, gaps are formed between the first spring seat 81 and the inner surface of the valve sleeve 71, between the valve core 2 and the inner surface of the valve sleeve 71, and between the second spring seat 82 and the inner surface of the valve sleeve 71, so that the high-pressure oil can flow into the pilot cavity 10 after passing through the third spring seat 83 and the inner flow channel 41 of the pilot valve core 4. Preferably, a cut groove 821 is formed on an outer surface of the second spring seat 82 to form a gap with an inner surface of the valve housing 71, through which high pressure oil passes. Further preferably, the number of the cutting grooves 821 is two, and the two cutting grooves 821 are uniformly arranged in the circumferential direction.

As a preferable solution of the present embodiment, the first elastic member 31, the second elastic member 32, the third elastic member 33, and the fourth elastic member 34 may be springs, and the third elastic member 33 is further preferably a conical spring.

Based on the above structure, the working principle of the overflow valve of this embodiment is:

1) Overflow condition:

in the overflow working condition, the valve seat 1 is tightly attached to the inner surface of the insertion hole 61 of the valve body 6 under the action of the first elastic piece 31 and the third elastic piece 33; part of the high-pressure oil introduced from the first oil port 62 enters the pilot chamber 10 through the gap between the first spring seat 81 and the valve sleeve 71, the annular gap between the valve core 2 and the valve sleeve 71, the cutting groove 821 on the second spring seat 82, the third spring seat 83 and the inner flow path 41 of the pilot valve core 4; because the two end surfaces of the pilot valve core 4 have area difference, the pilot valve core 4 moves towards the valve core 2 after being pressed until being limited by the pilot valve sleeve 5; meanwhile, the pilot valve core 4 pushes the third spring seat 83 to compress the second elastic member 32 and the fourth elastic member 34, and the second elastic member 32 is compressed to apply a pretightening force to the second spring seat 82 and simultaneously to the valve core 2, so that the valve core 2 receives an elastic force opposite to the direction of the first elastic member 31, and therefore, the spring force applied to the valve core 2 is the difference between the acting forces of the first elastic member 31 and the second elastic member 32.

Part of the high-pressure oil acts on the valve core 2 and the first spring seat 81 thereon to cause the conical sealing surface 24 of the first end 21 of the valve core 2 to be far away from the valve seat 1, and the first oil port 62 to the second oil port 63 are opened, thereby realizing the overflow function.

2) Oil supplementing working condition:

when the oil is replenished, the pressure of the second oil port 63 is higher than that of the first oil port 62, and at the moment, the pressure is lower, the valve core 2, the valve seat 1, the first elastic piece 31 and the first spring seat 81 move integrally, and the conical sealing surface 24 of the valve core 2 is tightly pressed on the valve seat 1; the pressure difference between the second oil port 63 and the first oil port 62 acts on the valve seat valve core, when the acting force is larger than the pretightening force of the third elastic member 33, the valve seat 1 moves rightwards together with the valve core 2, the first elastic member 31 and the first spring seat 81, the valve seat 1 leaves the inner surface of the insertion hole 61, the second oil port 63 is opened to the first oil port 62, and the oil of the second oil port 63 can be supplemented to the first oil port 62.

3) Pressure regulation:

the pressure of the relief valve of this embodiment is adjusted by adjusting the pretightening force of the second elastic member 32, thereby adjusting the opening pressure of the relief valve. By rotating the adjusting screw sleeve 72, the adjusting screw sleeve 72 moves axially, and drives the pilot valve sleeve 5 to move axially, when overflow occurs, the pilot valve core 4 is movably abutted against the stepped surface 51 of the pilot valve sleeve 5 under the action of high-pressure oil, the compression amount of the second elastic piece 32 is correspondingly changed, and the elastic force of the valve core 2 is further changed, so that the precompression amount of the valve core 2 is changed.

The embodiments of the present utility model have been described in detail with reference to the drawings, but the present utility model is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the spirit of the present utility model.

Claims (10)

1. An overflow valve, comprising:

the valve seat (1), the radial oil hole (11) is formed on the valve seat (1);

the valve core (2) penetrates through the valve seat (1), and under the action of the first elastic piece (31), the first end (21) of the valve core (2) abuts against the opening of the valve seat (1) to form a seal;

the pilot assembly comprises a pilot valve core and a pilot valve sleeve, the pilot valve core is slidably assembled in the pilot valve sleeve, the pilot valve core acts on the second end of the valve core (2) through a second elastic piece (32), and the position of the pilot valve sleeve is adjustable.

2. An overflow valve according to claim 1, characterized in that the inner peripheral surface of the pilot valve sleeve (5) is formed with a stepped surface (51), the outer diameter of the pilot valve spool (4) varies, the pilot valve spool (4) abutting against the stepped surface (51) to define its range of movement towards the spool (2).

3. An overflow valve according to claim 2, characterized in that the pilot valve sleeve (5) is provided with an air hole (52), one end of the air hole (52) extends to the outer circumferential surface of the pilot valve sleeve (5), and the other end of the air hole (52) extends to the inner circumferential surface of the pilot valve sleeve (5) and is close to the step surface (51).

4. The relief valve according to claim 1, characterized in that an inner flow passage (41) is formed in the pilot spool (4), a pilot chamber (10) is formed at an end of the pilot spool (4) away from the spool (2), and high-pressure oil during relief flows through the inner flow passage (41) to the pilot chamber (10).

5. An overflow valve according to claim 1, characterized in that it further comprises a mounting sleeve (7) and a valve body (6), said valve seat (1), valve core (2) and pilot assembly being fitted to said valve body (6) by means of said mounting sleeve (7).

6. The overflow valve according to claim 5, characterized in that an insertion hole (61) is formed in the valve body (6), a first oil port (62) and a second oil port (63) are also formed in the valve body (6), the first oil port (62) and the second oil port (63) are both communicated with the insertion hole (61), and the valve seat (1) and the valve core (2) extend into the insertion hole (61) to control the on-off between the first oil port (62) and the second oil port (63).

7. An overflow valve according to claim 6, characterized in that the outer surface of the valve seat (1) is formed with a conical surface (12), the conical surface (12) of the valve seat (1) can be abutted against the inner wall of the insertion hole (61) to form a seal, the first oil port (62) is positioned at the periphery of the valve core (2), and the first oil port (62) is connected with high-pressure oil; the second oil port (63) is arranged corresponding to the end face of the first end (21) of the valve core (2), and the second oil port (63) is connected with low-pressure oil.

8. An overflow valve according to claim 5, characterized in that the mounting sleeve (7) comprises a valve sleeve (71) and an adjusting screw sleeve (72), the valve sleeve (71) is a sleeve body with two open ends, one end of the valve sleeve (71) is assembled on the valve body (6), the other end of the valve sleeve (71) is connected with the adjusting screw sleeve (72) in a threaded manner, and the pilot valve sleeve (5) is assembled with the adjusting screw sleeve (72) in a follow-up manner.

9. An overflow valve according to claim 1, characterized in that the valve core (2) is provided with a first spring seat (81), and both ends of the first elastic member (31) act on the valve seat (1) and the first spring seat (81), respectively; a third elastic piece (33) is further arranged on the other side of the first spring seat (81), and the third elastic piece (33) acts on the first spring seat (81); the second end (22) of the valve core (2) is provided with a second spring seat (82), the end part, close to the valve core (2), of the pilot valve core (4) is provided with a third spring seat (83), and two ends of the second elastic piece (32) respectively act on the second spring seat (82) and the third spring seat (83).

10. The overflow valve according to claim 1, further comprising a fourth elastic member (34), wherein the fourth elastic member (34) is sleeved on the outer periphery of the second elastic member (32), and the fourth elastic member (34) provides a restoring force for the pilot valve core (4).