A slide valve type hydraulic directional valve with a special sealing valve core structure

Abstract

This invention discloses a spool-type hydraulic directional valve with a special sealing valve core structure. The sealing structure of the valve core and valve hole under emulsion, water and other water-based transmission media effectively ensures the sealing performance of the spool-type hydraulic directional valve, improves the working reliability of the spool-type hydraulic directional valve, and expands the application range of the spool-type hydraulic directional valve.

Description

Technical Field

[0001] This invention belongs to the field of control valves and relates to a slide valve type hydraulic directional valve with a special sealing valve core structure. Background Technology

[0002] The working medium is a crucial component of a hydraulic system. The reliable, efficient, safe, and economical operation of a hydraulic system is closely related to the performance of the selected working medium. In hydrostatic systems, working media are mainly divided into two categories: mineral oil and fire-retardant fluids. Mineral oil-based working media have many advantages, but their main disadvantage is their flammability. Using mineral oil-based hydraulic fluids near open flames, high-temperature heat sources, or other areas prone to fire poses a fire hazard. Therefore, mineral oil-based hydraulic fluids are not permitted as working media in the vicinity of high-temperature open flames or underground coal mines; instead, fire-retardant fluids must be used. For example, fire-retardant fluids are used as working media in hydraulic systems in underground coal mines, while emulsions or pure water are used as working media for hydraulic supports and external injection-type single-unit hydraulic supports.

[0003] Directional control valves, as conventional hydraulic components, are widely used in hydraulic systems under various conditions, with spool-type directional control valves being the most widely applied. However, for spool-type directional control valves, since they operate by utilizing the relative movement of the spool valve core relative to the valve body bore, a clearance inevitably exists between the spool valve core and the valve body bore. The sealing of the directional control valve is an annular clearance seal, and the flow state of the annular clearance between the spool valve core and the valve body bore is generally laminar. The higher the working pressure, the greater the internal leakage. Excessive leakage of the directional control valve will lead to severe overheating of the hydraulic system, reduced efficiency, and affect the movement speed of the actuators. Due to the requirement of low viscosity or higher for emulsion-type water-based flame-retardant fluids, water, and other water-based flame-retardant media, spool-type directional control valves generally use mineral oil-based hydraulic oil as the working medium.

[0004] Because emulsions, water, and other water-based flame-retardant media are not suitable for current slide valve-type directional control valves, directional control valves for hydraulic supports in underground coal mines are all in the form of cone valves or ball valves. Cone valve-type directional control valves achieve switching by opening or closing the cone valve core relative to the valve seat. They have good sealing performance, but a single cone valve can only achieve a two-position three-way function. Therefore, to obtain more complex functions, multiple valves must be combined.

[0005] Currently, the directional control valves used in hydraulic supports are disc-type structures. Each disc valve consists of an operating mechanism, two sets of valve cores, and a valve body. Each set of valve cores forms a two-position three-way directional control valve, which uses a cone valve seal. The two sets of valve cores (two-position three-way valves) form a three-position four-way directional control valve. Therefore, the directional control valve effectively functions as a three-position four-way directional control valve. This design is complex, increasing the processing and maintenance costs of the equipment. Using a spool-type three-position four-way valve would simplify the structure and improve reliability. Therefore, in the actual working environment of underground coal mines, there is an urgent need to design a directional control valve structure that can reliably seal to prevent leakage while also enabling directional control operations through a simple structure.

[0006] Similarly, similar problems exist in hydraulic systems where the hydraulic directional valves use water or other water-based media. Summary of the Invention

[0007] To address the aforementioned problems, this invention provides a slide valve-type hydraulic directional valve with a special sealing valve core structure. This valve has a simple structure, can be used in emulsions, water, and other water-based transmission media, and effectively ensures the sealing performance of the hydraulic directional valve, thereby improving its operational reliability and increasing its working efficiency.

[0008] The technical solution of the present invention is as follows:

[0009] A spool-type hydraulic directional valve with a special sealing valve core structure includes a directional valve body, a return spring, a linear rolling bearing, a spool valve core, and a sealing ring. The directional valve body has a valve hole that mates with the spool valve core and multiple channels for communicating with inlet and outlet fluid passages. The spool valve core is coaxially clearance-fitted with the valve hole. Return springs, coaxial with the spool valve core, are sleeved at both ends of the spool valve core. The directional valve body can be integral or separate. The spool valve core is a cylindrical structure with multiple annular guide grooves. The left column of the spool valve core is rotatably connected to the left valve body via a left linear rolling bearing, and the right column of the spool valve core is rotatably connected to the right valve body via a right linear rolling bearing. The sealing position between the spool valve core and the valve body is not sealed by a rigid shaft-hole clearance fit, but rather by a sealing groove containing a polymer sealing ring.

[0010] Specifically, in the spool valve type hydraulic directional valve, the polymer sealing ring is installed on the valve core. A sealing groove is provided on the left column of the spool valve core near the left annular guide groove, and a sealing groove is also provided on the right column of the spool valve core near the right annular guide groove. Sealing grooves are provided on both sides of the middle column of the spool valve core, and a sealing ring is installed in each of the above sealing grooves.

[0011] Specifically, the valve hole inside the valve body of the spool-type hydraulic directional valve is vertically connected to the multi-channel, and an annular recess coaxial with the valve hole is provided at the connection point. The transition chamfer between the shoulder of the recess and the valve hole is a straight line, an arc, or a combination of a straight line and an arc. This is used to reduce the instantaneous impact or shearing of the shoulder edge on the sealing ring when the spool valve core moves and enters or exits the sealing area.

[0012] Specifically, in the slide valve type hydraulic directional valve, the polymer sealing ring is installed inside the valve body. The valve hole inside the valve body is vertically connected to the multi-channel. An annular recess coaxial with the valve hole is provided at the connection point. Sealing grooves are provided on both sides of the annular recess on the left side of the valve body. Sealing grooves are also provided on both sides of the annular recess on the right side of the valve body. Sealing grooves are provided on both sides of the annular recess in the middle of the valve body. Sealing rings are installed in all of the above sealing grooves.

[0013] Specifically, the valve core of the slide valve type hydraulic directional valve has a chamfered structure at multiple annular guide grooves. The chamfers on the end faces of the columns on both sides of the multiple annular guide grooves are straight, curved, or a combination of straight and curved types. This is used to reduce the instantaneous impact or shearing of the valve core's edges on the sealing ring when the slide valve core moves and enters or exits the sealing area.

[0014] Specifically, the sealing structure between the valve core and the valve body of the spool-type hydraulic directional valve is either a sealing ring installed on the valve core with a transition chamfer on the valve body, or a sealing ring installed inside the valve body with a chamfer on the valve core.

[0015] Specifically, the valve body, valve core, and return spring of the spool-type hydraulic directional valve are all made of rust-resistant materials, such as copper or stainless steel, or have an anti-oxidation layer on the inner and outer surfaces.

[0016] Specifically, the working medium of the slide valve type hydraulic directional valve of the present invention is emulsion, water and other water-based transmission media;

[0017] Specifically, the slide valve type hydraulic directional valve of the present invention is a hydraulic directional valve for water-based media hydraulic systems or for hydraulic supports in underground coal mines;

[0018] The technical effects brought about by the technical solution of the present invention are as follows:

[0019] Ordinary spool-type directional control valves lack sealing rings, resulting in a gap seal between the valve body and the valve core. Hydraulic supports operate at high pressures, leading to significant leakage of the working medium. This designed spool-type directional control valve incorporates sealing rings and is designed for working media such as emulsions, water, and other water-based flame-retardant media, eliminating leakage.

[0020] The chamfered structure on the valve body or valve core is designed with a specific shape through finite element analysis. This shape can be a straight line, an arc, or a combination of straight lines and arcs. It is used in conjunction with a sealing ring of a specific shape. The purpose is to prevent the sealing ring from being violently squeezed when entering and leaving the valve hole during reversing, so that the reversing valve can reverse smoothly and extend its service life.

[0021] The sealing ring is made of high-polymer material, which is wear-resistant, corrosion-resistant, self-lubricating, and reliable in operation.

[0022] Linear rolling bearings are installed at both ends of the valve core. Since emulsions, water, and other water-based flame-retardant media have poor lubricity, the installation of linear rolling bearings allows for point contact between the internal rolling steel balls and the valve core, enabling high-precision and smooth linear motion with minimal frictional resistance. This helps reduce wear on the directional control valve and extend its service life.

[0023] Conventional spool-type directional control valves often experience hydraulic jamming, thus requiring a high degree of coaxiality between the valve core and body. This design, however, mitigates this hydraulic jamming issue by incorporating a linear rolling bearing.

[0024] It should be noted that the directional control valves described in this specification include, but are not limited to, three-position four-way valves. Specifically, they may be two-position two-way valves, two-position three-way valves, two-position four-way valves, two-position five-way valves, three-position four-way valves, three-position five-way valves, etc. Moreover, the design is for all directional control valves with a spool valve in the neutral position function. The neutral position function can be O-type, Y-type, P-type, H-type, etc. Attached Figure Description

[0025] Figure 1 This is a front cross-sectional view of a slide valve-type hydraulic directional valve with a special sealing valve core structure according to the present invention (the sealing ring is installed on the valve core).

[0026] Figure 2 This is a top cross-sectional view of a slide valve-type hydraulic directional valve with a special sealing valve core structure according to the present invention (the sealing ring is installed on the valve core).

[0027] Figure 3 This is a partial schematic diagram of the shoulder of the valve orifice of a slide valve type hydraulic directional valve with a special sealing valve core structure according to the present invention (the sealing ring is installed on the valve core).

[0028] Figure 4 This is a front cross-sectional view of a slide valve-type hydraulic directional valve with a special sealing valve core structure according to the present invention (the sealing ring is installed inside the valve body).

[0029] Figure 5 This is a partial schematic diagram of the end face of the valve core of a slide valve-type hydraulic directional valve with a special sealing valve core structure according to the present invention (the sealing ring is installed inside the valve body).

[0030] Reference numerals: 1-Reversing valve body, 2-Spool valve core, 3-Sealing ring, 4-Valve bore, 5-Linear rolling bearing, 6-Return spring, 7-Shoulder of annular recess, 8-Edge, 9-Chamfered transition between shoulder and valve bore, 10-Annular guide groove, 11-Sealing groove on valve core, 12-Sealing ring, 13-Annular recess, 14-Sealing groove on valve body, 15-Sealing ring, 16-Chamfered end face of valve core, 17-Annular guide groove Detailed Implementation

[0031] Example 1

[0032] A spool-type hydraulic directional valve with a special sealing valve core structure, specifically a three-position four-way valve, includes a directional valve body 1, a return spring 6, a linear rolling bearing 5, a spool valve core 2, and a sealing ring assembly 3; the directional valve body 1 has a valve hole 4 that mates with the spool valve core 2 and multiple channels for communicating with inlet and outlet liquid channels; the spool valve core 2 is coaxially clearance-fitted with the valve hole 4; and return springs 6, coaxial with the spool valve core 2, are sleeved at both ends of the spool valve core 2. The directional valve body 1 is characterized by being divided into a left valve body, a right valve body, and a middle valve body. The valve bodies are sealed together by sealing gaskets. Two return springs 6 are located inside the left and right valve bodies respectively. The spool valve core 2 is a cylindrical structure with multiple annular guide grooves 10. The left column of the spool valve core 2 is rotatably connected to the left valve body 1 through the left linear rolling bearing 5. The right column of the spool valve core 2 is rotatably connected to the right valve body 1 through the right linear rolling bearing 5. The position between the spool valve core 2 and the valve body 1 that needs to be sealed is not sealed by a rigid shaft hole fit gap, but is provided with a sealing groove 11. There is a polymer sealing ring 12 in the groove for sealing.

[0033] Specifically, in the slide valve type hydraulic directional valve, the polymer sealing ring 12 is installed on the valve core 2. A sealing groove 11 is provided on the left column of the valve core 2 near the left annular guide groove 10. A sealing groove is also provided on the right column of the slide valve core near the right annular guide groove. Sealing grooves are provided on both sides of the middle column of the slide valve core. A sealing ring 12 is installed in each of the above sealing grooves.

[0034] Specifically, the valve hole 4 inside the valve body 1 of the spool valve is vertically connected to the multi-channel, and an annular recess coaxial with the valve hole is provided in the connection. The shoulder 7 of the recess and the transition chamfer 9 of the valve hole are straight, arc, or a combination of straight and arc types. This is used to reduce the instantaneous impact or shearing of the shoulder edge 8 on the sealing ring 12 when the spool valve core 2 moves and enters and exits the sealing area.

[0035] Specifically, the valve body 1, the spool valve core 2, and the return spring 6 of the spool-type hydraulic directional valve are all made of materials that are not easy to rust, such as copper or stainless steel, or have an anti-oxidation layer structure on the inner and outer surfaces.

[0036] Specifically, the working medium of the slide valve type hydraulic directional valve of the present invention is emulsion, water and other water-based transmission media;

[0037] Specifically, the slide valve type hydraulic directional valve of the present invention is a hydraulic directional valve for water-based media hydraulic systems or for hydraulic supports in underground coal mines;

[0038] Specifically, the sealing ring is an O-ring, Y-ring, or V-ring, or a specially made polymer sealing ring.

[0039] Specifically, the working principle of the slide valve type hydraulic directional valve is as follows:

[0040] When the spool 2 of the spool valve moves to the left, port P is connected to port B and port A is connected to port T; when the spool 2 of the spool valve moves to the right, port P is connected to port A and port B is connected to port T; when the spool 2 of the spool valve is in the neutral position, ports P, A, B and T are not connected.

[0041] Example 2

[0042] A spool-type hydraulic directional valve with a special sealing valve core structure, specifically a three-position four-way valve, includes a directional valve body 1, a return spring 6, a linear rolling bearing 5, a spool valve core 2, and a sealing ring assembly 3; the directional valve body 1 has a valve hole 4 that mates with the spool valve core 2 and multiple channels for communicating with inlet and outlet liquid channels; the spool valve core 2 is coaxially clearance-fitted with the valve hole 4; and return springs 6, coaxial with the spool valve core 2, are sleeved at both ends of the spool valve core 2. The directional valve body 1 is characterized by being divided into a left valve body, a right valve body, and a middle valve body. The valve bodies are sealed together by sealing gaskets. Two return springs 6 are located inside the left and right valve bodies respectively. The spool valve core 2 is a cylindrical structure with multiple annular guide grooves 17. The left column of the spool valve core 2 is rotatably connected to the left valve body 1 through the left linear rolling bearing 5. The right column of the spool valve core 2 is rotatably connected to the right valve body 1 through the right linear rolling bearing 5. The position between the spool valve core 2 and the valve body 1 that needs to be sealed is not sealed by a rigid shaft hole fit gap, but is provided with a sealing groove 14. There is a polymer sealing ring 15 in the groove for sealing.

[0043] Specifically, in the slide valve type hydraulic directional valve, the polymer sealing ring 14 is installed inside the valve body 1. The valve hole 4 inside the valve body 1 is vertically connected to the multi-channel. An annular recess 13 coaxial with the valve hole 4 is provided at the connection point. Sealing grooves 14 are provided on both sides of the annular recess on the left side of the valve body. Sealing grooves 14 are also provided on both sides of the annular recess on the right side of the valve body. Sealing grooves 14 are provided on both sides of the annular recess in the middle of the valve body. Sealing rings 15 are installed in each of the above sealing grooves 14.

[0044] Specifically, the valve core 2 of the slide valve type hydraulic directional valve is provided with a chamfer structure 16 at multiple annular guide grooves 17. The chamfer 16 on the end face of the column on both sides of the multiple annular guide grooves is a straight line, an arc, or a combination of straight line and arc. It is used to reduce the instantaneous impact or shearing of the valve core column edge on the sealing ring when the slide valve core 2 moves and enters and exits the sealing area.

[0045] Specifically, the valve body 1, the spool valve core 2, and the return spring 6 of the spool-type hydraulic directional valve are all made of materials that are not easy to rust, such as copper or stainless steel, or have an anti-oxidation layer structure on the inner and outer surfaces.

[0046] Specifically, the working medium of the slide valve type hydraulic directional valve of the present invention is emulsion, water and other water-based transmission media;

[0047] Specifically, the slide valve type hydraulic directional valve of the present invention is a hydraulic directional valve for water-based media hydraulic systems or for hydraulic supports in underground coal mines;

[0048] Specifically, the sealing ring is an O-ring, Y-ring, or V-ring, or a specially made polymer sealing ring.

[0049] Specifically, the working principle of the slide valve type hydraulic directional valve is as follows:

[0050] When the spool 2 of the spool valve moves to the left, port P is connected to port B and port A is connected to port T; when the spool 2 of the spool valve moves to the right, port P is connected to port A and port B is connected to port T; when the spool 2 of the spool valve is in the neutral position, ports P, A, B and T are not connected.

[0051] Example 3:

[0052] This invention patent can also be used for similar structures such as two-position two-way valves, two-position three-way valves, two-position four-way valves, two-position five-way valves, and three-position five-way valves.

Claims

1. A spool-type hydraulic directional valve with a special sealing valve core structure, characterized in that, The working medium of the slide valve type hydraulic directional valve is a water-based, flame-retardant transmission medium. It includes a directional valve body, a return spring, a linear rolling bearing, a spool valve core, and a sealing ring. The directional valve body, the spool valve core, and the return spring are all made of materials that are not easy to rust. The valve body of the reversing valve is provided with a valve hole that mates with the valve core of the slide valve and multiple channels for communicating with the inlet and outlet liquid channels. The valve core of the slide valve and the valve hole are coaxially and clearance-fitted. Both ends of the slide valve core are fitted with return springs that are coaxial with the slide valve core. The left column of the slide valve core is rotatably connected to the left valve body via a left linear rolling bearing, and the right column of the slide valve core is rotatably connected to the right valve body via a right linear rolling bearing. The slide valve core is provided with multiple annular flow guide groove structures; A sealing groove is provided at the position where sealing is required between the valve core and the valve body, and a sealing ring made of polymer material is installed in the sealing groove. When the sealing ring is installed on the spool valve core, the directional valve body has a transition chamfer; when the sealing ring is installed on the directional valve body, the spool valve core has a transition chamfer. The shape of the transition chamfer is optimized based on finite element analysis and can be a straight line, an arc, or a combination of straight and arc shapes. It is used to reduce the instantaneous impact or shearing on the sealing ring when the spool valve core moves. Its polymer sealing ring is installed on the spool valve core. A sealing groove is provided on the left side of the spool valve core near the left guide ring groove, and a sealing groove is also provided on the right side of the spool valve core near the right guide ring groove. Sealing grooves are provided on both sides of the middle spool valve core, and sealing rings are fitted into each of these sealing grooves; or... The polymer sealing ring is installed inside the valve body of the reversing valve. The valve hole inside the valve body is perpendicularly connected to the multi-channel. An annular recess coaxial with the valve hole is provided at the connection point. Sealing grooves are provided on both sides of the annular recess on the left side of the valve body. Sealing grooves are also provided on both sides of the annular recess on the right side of the valve body. Sealing grooves are provided on both sides of the annular recess in the middle of the valve body. Sealing rings are installed in all of the above sealing grooves.

2. The spool-type hydraulic directional valve with a special sealing valve core structure according to claim 1, characterized in that: The valve hole inside the directional valve body is perpendicularly connected to the multi-channel. An annular recess coaxial with the valve hole is provided at the connection point. The transition chamfer is provided at the connection between the shoulder of the annular recess and the valve hole to reduce the instantaneous impact or shearing of the shoulder edge on the sealing ring when the spool moves and enters and exits the sealing zone.

3. The spool-type hydraulic directional valve with a special sealing valve core structure according to claim 1, characterized in that: The transition chamfer is provided at multiple annular guide grooves on the spool valve core column. The transition chamfer at the end face of the column on both sides of the multiple annular guide grooves is used to reduce the instantaneous impact or shearing of the valve core column edges on the sealing ring when the spool valve core moves and enters and exits the sealing zone.

4. The spool-type hydraulic directional valve with a special sealing valve core structure according to any one of claims 1 to 3, characterized in that: The slide valve type hydraulic directional valve is a hydraulic directional valve used in water-based media hydraulic systems or in hydraulic supports in underground coal mines.

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