CN220769832U - Direct-acting low-pressure overflow valve - Google Patents

Abstract

The utility model discloses a direct-acting low-pressure overflow valve, which comprises a valve sleeve (3), wherein a valve core (4) is arranged in the valve sleeve (3), one end outside the valve sleeve (3) is provided with a threaded sleeve (2) and a locking nut (1), the other end of the valve sleeve (3) is provided with a spring seat (6) and a spring (7) which are matched with the valve core (4), the valve core (4) comprises a valve core main body (a), and damping grooves (z) which are symmetrically distributed are arranged on the cylindrical surface of the valve core main body (a). The utility model can improve the constant pressure precision and sensitivity of the overflow valve, eliminate vibration and reduce noise, enhance the sealing when the valve is closed and reduce leakage; on the other hand, the service lives of the oil supplementing pump, the closed pump and the system can be prolonged, the energy consumption is reduced, and the market competitiveness of the product is improved.

Description

Direct-acting low-pressure overflow valve

Technical Field

The utility model relates to an overflow valve, in particular to a direct-acting low-pressure overflow valve.

Background

The overflow valve has the main function of fixing pressure or protecting safety of the hydraulic system. The overflow valve works by utilizing the principle that hydraulic force and spring force acting on the valve core are balanced, specifically, the compression amount of the spring is changed by utilizing the controlled pressure as a signal, so that the flow area of the valve port and the overflow amount of the system are changed to achieve the purpose of constant pressure.

In the closed system, an inlet oil pipe of the closed pump is directly connected with an outlet oil pipe of the execution element, an oil outlet pipe of the closed pump is directly connected with the inlet oil pipe of the execution element, and working fluid is subjected to closed circulation in a pipeline of the system. The speed change and the reversing of the working mechanism are realized by a variable mechanism for adjusting a pump or a motor, so that hydraulic impact and energy loss in the reversing process of an open system are avoided. However, the oil liquid after the closed system works does not return to the oil tank, so that the heat dissipation condition of the oil liquid is poorer than that of an open system. For heat dissipation of the system, a small-capacity oil compensating pump is usually required for oil compensation, and in the process, a low-pressure relief valve is required for protecting the oil compensating pump and setting the pressure of the oil compensating pump.

Li Tong, shi Jinwu development and application of a concrete mixer truck backing pump (L4 VTG 90) [ J ]. Fluid transmission and control, 2010, (5): 56-60, the L4VTG90 adjustable low-pressure overflow valve can meet the requirements of protecting the oil supplementing pump and fixing the pressure of the oil supplementing pump, but the valve has the problems of low fixed pressure precision, low sensitivity, large vibration and noise, poor sealing and large leakage when the valve is closed in the use process. And the service lives of the oil supplementing pump, the closed pump and the system are influenced when the energy consumption of the existing adjustable low-pressure overflow valve is high. Therefore, there is a need to develop an overflow device of a low pressure overflow valve to solve the above technical problems.

Disclosure of Invention

The utility model aims to provide a direct-acting low-pressure overflow valve. The utility model can improve the constant pressure precision and sensitivity of the overflow valve, eliminate vibration and reduce noise, enhance the sealing when the valve is closed and reduce leakage; on the other hand, the service lives of the oil supplementing pump, the closed pump and the system can be prolonged, the energy consumption is reduced, and the market competitiveness of the product is improved.

The technical scheme of the utility model is as follows: the direct-acting low-pressure overflow valve comprises a valve sleeve, wherein a valve core is arranged in the valve sleeve, one end outside the valve sleeve is provided with a threaded sleeve and a locking nut, the other end of the valve sleeve is provided with a spring seat and a spring matched with the valve core, the valve core comprises a valve core main body, and damping grooves which are symmetrically distributed are arranged on the cylindrical surface of the valve core main body.

In the direct-acting low-pressure overflow valve, the valve sleeve comprises a valve sleeve body, an axial cylindrical surface is arranged in the valve sleeve body, an orifice sharp edge is arranged at an orifice of the axial cylindrical surface, and a valve sleeve radial hole communicated with the axial cylindrical surface is further formed in the valve sleeve body; the inner side of the sharp edge of the orifice is also provided with an axial expansion surface, and the depth of the axial expansion surface exceeds the radial hole of the valve sleeve.

In the direct-acting low-pressure overflow valve, the outer cylindrical surface of the valve sleeve body matched with the rear cover is also provided with a mechanical sealing ring groove.

In the direct-acting low-pressure overflow valve, a mechanical seal ring is arranged in the mechanical seal ring groove.

Compared with the prior art, the symmetrical damping grooves are designed on the cylindrical surface of the valve core main body, so that the valve core is stable in the moving process, no clamping stagnation exists, and the sensitivity of the valve is improved; vibration and noise in the working process of the valve can be eliminated; according to the valve sleeve, the axial expansion surface is arranged on the inner side of the orifice sharp edge of the valve sleeve body, namely, the diameter (the axial expansion surface) of a hole is increased on the orifice sharp edge section under the condition that the total length of the valve sleeve is unchanged, and the depth exceeds the radial hole of the valve sleeve, so that the sharp edge shape of the valve sleeve matched with the conical surface of the valve core is ensured to be not elliptical, the valve sleeve can be matched with the conical surface of the valve core well, the sealing is good, the leakage is reduced, the constant pressure precision of the valve is improved, and the sensitivity of the valve is improved; the valve core is matched with the valve sleeve, so that the interchangeability is high, and the valve core is easy to assemble and maintain. In addition, the mechanical seal ring groove is added on the outer cylindrical surface matched with the valve sleeve body and the rear cover, so that the mechanical seal ring is assembled, the sealing is good, the leakage is reduced, the constant pressure precision of the valve is improved, and the sensitivity of the valve is improved. Through the mutual cooperation between the structures, the performance of the valve can be effectively improved, the service lives of the oil supplementing pump, the closed pump and the system are prolonged, the energy consumption is reduced, and the market competitiveness of the product is improved. In summary, the utility model can improve the constant pressure precision and sensitivity of the overflow valve, eliminate vibration and reduce noise, enhance the seal when the valve is closed, and reduce leakage; on the other hand, the service lives of the oil supplementing pump, the closed pump and the system can be prolonged, the energy consumption is reduced, and the market competitiveness of the product is improved.

Drawings

FIG. 1 is a structural view of the present utility model;

fig. 2 is a structural view of the valve sleeve;

fig. 3 is a structural view of the spool.

The marks in the drawings are: 1-lock nut, 2-screw sleeve, 3-valve sleeve, 4-valve core, 5-mechanical seal ring, 6-spring seat, 7 spring, A-axial cylindrical surface, B-orifice sharp edge, C-axial expansion surface, F-mechanical seal ring groove and K-valve sleeve radial hole; a-valve core main body, b-valve core conical surface, d-valve core spherical surface and z-damping groove; and the P-is communicated with an outlet of the oil supplementing pump, and the T-is communicated with an oil return port of the closed pump.

Detailed Description

The utility model is further illustrated by the following figures and examples, which are not intended to be limiting.

Examples. As shown in fig. 1, 2 and 3, a valve sleeve 3 is in threaded connection with a threaded sleeve 2 and is locked by a locking nut 1; the outer cylindrical surface E of the valve sleeve 3 is in clearance fit with the cylindrical surface of a rear cover (not shown in the figure); the mechanical seal ring 5 is assembled in a mechanical seal ring groove F of the valve sleeve 3 and matched with a rear cover (not shown in the figure) to form a mechanical seal; the cylindrical surface of the valve core main body a is in clearance fit with the axial cylindrical surface A of the valve sleeve 3, the valve core 4 axially moves in the valve sleeve 3, the valve core conical surface B is matched with the orifice sharp edge B, the valve core spherical surface d is in contact with the spring seat 6, the spring seat is automatically centered by the valve core spherical surface d, the spring 7 is positioned by the spring seat 6 and assembled between the spring seat and a rear cover (not shown in the figure), and the spring compresses the valve core 4 through compressing the spring seat, so that the valve core 4 is compressed on the valve sleeve 3. The M cavity and the N cavity are closed cavities formed by the valve sleeve 3 and the valve core 4, and the two cavities are communicated through a damping groove z of the valve core 4. And P is communicated with an outlet of the oil supplementing pump, and T is communicated with oil return of the closed pump.

The working principle of the low-pressure overflow valve is as follows:

when the oil pressure at the outlet of the oil supplementing pump rises to a certain value, oil enters an N cavity through a P port and a valve sleeve radial hole K of a valve sleeve 3, then enters an M cavity through a valve core 4 damping groove z, the oil pressure acts on the left end face of the valve core 4, and when the product of the oil pressure acting on the left end face of the valve core 4 and the area of the left end face of the valve core 4 is equal to the elastic force of a spring 7, the valve is in an opened critical state; when the product of the oil pressure on the left end face of the valve core 4 and the area of the left end face of the valve core 4 is larger than the elastic force of the spring 7, the valve core 4 moves rightward, the valve core conical surface B is separated from the orifice sharp edge B, an opening is formed, and the oil of the P port enters the T port. On the contrary, when the oil pressure at the outlet of the oil supplementing pump is reduced, the process is reversed, the valve core 4 moves leftwards under the action of the spring, the conical surface B of the valve core is pressed on the sharp edge B of the orifice, and the P orifice and the T orifice are blocked from being communicated, so that the oil pressure at the outlet of the oil supplementing pump is stabilized at a certain pressure value. Realizing the constant pressure of the oil supplementing pump.

The axial expansion surface is an axial cylindrical surface with an enlarged diameter.

When the rotation speed of the oil supplementing pump is abnormally increased, the flow rate of the outlet of the oil supplementing pump is instantaneously increased, the pressure of the outlet of the oil supplementing pump is instantaneously increased, at the moment, the opening of the overflow valve is increased, and oil liquid is discharged from the P port to the T port, so that the protection of the oil supplementing pump, the closed pump and the system is realized.

In the above process, the valve element 4 is in a dynamic balancing process.

In the process, the valve core 4 moves left and right, and the valve core 4 moves stably and has no clamping stagnation due to the action of the damping groove z, so that vibration is eliminated and noise is reduced; the diameter of the axial expansion surface part is increased, and the part is processed after heat treatment, so that the deformation of the orifice part of the valve sleeve caused by the heat treatment deformation around the radial hole is avoided, the shape of the orifice sharp edge is good and is not elliptical, the orifice sharp edge B is well sealed with the conical surface B of the valve core, and the leakage is less; the mechanical seal ring is added on the axial cylindrical surface E, so that the sealing is good, and the leakage is less; the two parts are sealed well, and the oil supplementing efficiency is high. The constant pressure precision and the sensitivity of the valve are comprehensively improved, the vibration is eliminated, the noise is reduced, the sealing is enhanced, and the leakage is reduced; the service lives of the oil supplementing pump and the closed pump are prolonged, and the market competitiveness of the product is improved.

The foregoing is merely a preferred embodiment of the present utility model, and it should be noted that modifications and variations could be made by those skilled in the art without departing from the technical principles of the present utility model, and such modifications and variations should also be regarded as being within the scope of the utility model.

Claims (4)

1. The utility model provides a direct acting low pressure overflow valve, includes valve pocket (3), is equipped with case (4) in valve pocket (3), and the one end outside valve pocket (3) is equipped with swivel nut (2) and lock nut (1), and valve pocket (3) other end is equipped with spring holder (6) and spring (7) with case (4) matched with, its characterized in that: the valve core (4) comprises a valve core main body (a), and symmetrically distributed damping grooves (z) are formed in the cylindrical surface of the valve core main body (a).

2. The direct acting low pressure relief valve of claim 1, wherein: the valve sleeve (3) comprises a valve sleeve body, an axial cylindrical surface (A) is arranged in the valve sleeve body, an orifice sharp edge (B) is arranged at an orifice of the axial cylindrical surface (A), and a valve sleeve radial hole (K) communicated with the axial cylindrical surface (A) is further formed in the valve sleeve body; the inner side of the orifice sharp edge (B) is also provided with an axial expansion surface (C), and the depth of the axial expansion surface (C) exceeds the radial hole (K) of the valve sleeve.

3. The direct acting low pressure relief valve of claim 2, wherein: and a mechanical sealing ring groove (F) is also arranged on the outer cylindrical surface (E) of the valve sleeve body matched with the rear cover.

4. A direct acting low pressure relief valve as defined in claim 3 wherein: and a mechanical sealing ring (5) is arranged in the mechanical sealing ring groove (F).