A shock-resistant hydraulic control valve

Abstract

The present invention relates to an impact-resistant hydraulic control valve, comprising a valve body, a valve cavity within the valve body, a valve stem elastically mounted in the valve cavity, a piston sleeve provided on a sliding sleeve on the valve stem, a first liquid passage hole and a second liquid passage hole provided on the valve body, a third liquid passage hole provided on the valve body or the valve stem, a first valve port and a second valve port provided on the valve body, a pilot control cavity formed in the valve body, a first mating step provided on the valve stem, a second mating step provided at the rear end of the piston sleeve, a stop provided on the piston sleeve, a limit step provided on the valve stem in the rearward movement path of the stop, the limit step and the stop being stopped and limited in front and back. The dimensions of the convex edge and the limit step satisfy the following conditions: when the first valve port of the valve body is closed and the piston sleeve is driven by the pilot fluid to move backward until it abuts the limit step, a liquid clearance of a predetermined size is formed between the second mating step and the second valve port. The movement speed of the piston sleeve end is reduced, thereby alleviating the impact force on the valve port.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic valves, and in particular to an impact-resistant hydraulic control valve. Background Art

[0002] In the fully mechanized mining working face of a coal mine, the hydraulically controlled reversing valve used in the hydraulic support is one of the most important hydraulic valves on the high-end hydraulic support. It receives the electric control signal output by the controller through the solenoid pilot valve to drive the corresponding two-position three-way valve string on the hydraulic control valve to realize the control of the hydraulic support.

[0003] The hydraulically controlled reversing valve includes a valve sleeve, an end sleeve, a valve seat, a sliding valve and a piston arranged in a front-to-back manner, the valve sleeve, the valve seat and the end sleeve being connected by a threaded connection. The valve sleeve is provided with a liquid inlet, the valve stem is provided with a flow hole, the valve stem has a liquid outlet connected to the bracket jack, and the end sleeve is provided with a corresponding liquid return port. At the same time, there are tapered valve ports at the front and rear ends of the inner side wall of the valve seat. The piston sleeve is provided at the front end of the valve stem and is sealed with the inner side wall of the end sleeve. When the piston moves back and forth The oil return port can be blocked during the process. The outer side of the rear end of the piston has a tapered fitting section that cooperates with the tapered valve port on the front side of the valve seat. During the backward movement of the piston, the return port can be blocked by the cooperation of the tapered fitting section and the tapered valve port. The rear end guide of the valve stem is assembled in the valve sleeve. The side wall of the valve stem has a tapered fitting section for cooperating with the tapered valve port on the rear side of the valve seat. During the forward movement of the valve stem, the liquid inlet is blocked by the cooperation of the tapered fitting section and the tapered valve port. In this way, an annular direction is achieved. In order to achieve reversing control, a pilot control port is generally provided on the front side of the piston corresponding to the end sleeve. The pilot control liquid enters the front chamber of the piston through the pilot control liquid path, thereby pushing the valve stem backward, causing the valve stem to move backward, closing the return port and opening the liquid inlet.

[0004] In actual use, the piston is a sliding sleeve mounted on the valve stem. The force applied to the piston is similar to that of a single-arm beam structure. During the process of sealing and closing the valve port of the piston and the valve seat, under the action of high pressure, the pilot fluid first pushes the piston to move. The movement of the piston from front to back is an instantaneous acceleration process, and before the conical surface collides with the conical surface of the valve seat, the end speed of the collision is extremely high. This high-speed collision will quickly damage the conical surface of the valve seat and the piston, accelerate material fatigue, and reduce the reliability of the valve string. Summary of the Invention

[0005] The purpose of the present invention is to provide an impact-resistant hydraulic control valve to solve the problem in the existing technology that during actual operation, when the piston sleeve and the valve port are closed, instantaneous high-speed impact causes damage to the mating surface of the valve port and the piston sleeve, affecting the reliability and service life of the valve body.

[0006] In order to solve the above problems, the impact-resistant hydraulic control valve involved in the present invention adopts the following technical solutions:

[0007] An impact-resistant hydraulic control valve includes a valve body, a valve cavity within the valve body, a valve stem elastically assembled in the valve cavity, a sliding sleeve on the valve stem is provided with a piston sleeve, a first liquid hole and a second liquid hole are provided on the valve body, a third liquid hole is provided on the valve body or the valve stem, a first valve port for connecting the first liquid hole and the third liquid hole is provided on the valve body, and a second valve port for connecting the second liquid hole and the third liquid hole is provided on the valve body, a pilot control cavity is formed in the valve body at the front side of the piston sleeve, a first matching step is provided on the valve stem, and a second matching step is provided at the rear end of the piston sleeve, and when the valve stem moves forward, the first valve port is blocked and the second valve port is opened When the first valve port of the valve body is closed and the piston sleeve is driven by the pilot fluid to move backward to abut against the limiting step, a liquid gap of a set size is formed between the second matching step and the corresponding second valve port, so that the piston sleeve first pushes the valve stem to open the first valve port when the second valve port is not blocked.

[0008] In a preferred embodiment, the rib is arranged at the front end of the piston sleeve.

[0009] In a preferred embodiment, the retaining edge is composed of an annular step formed by folding radially inward from the front end of the piston sleeve, the valve stem includes a small diameter section at the front end and a large diameter section at the rear end, and the limiting step is composed of a diameter-changing step formed between the large diameter section and the small diameter section.

[0010] In a preferred embodiment, the set size of the liquid gap is 1-2 mm.

[0011] In a preferred embodiment, the first valve port and the second valve port are both conical valve ports, the first liquid hole is the liquid inlet, the second liquid hole is the liquid return port, the third liquid hole is the liquid outlet arranged on the valve stem, and the first matching step and the second matching step are both conical steps.

[0012] In a preferred embodiment, the piston sleeve includes a main body section and a conical reducing section connected to the rear end of the main body section, the conical reducing section constitutes the second fitting step, and the rear end of the conical reducing section is connected to an equal-diameter pre-fitting section, the outer diameter of the equal-diameter pre-fitting section is smaller than the inner diameter of the valve seat, so that part of the liquid enters the liquid return port from the liquid inlet.

[0013] In a preferred embodiment, the pre-fitting section and the valve seat are clearance-fitted.

[0014] As described above, the present invention has the following beneficial effects: compared with the prior art, the impact-resistant hydraulic control valve involved in the present invention provides a stop plate on the piston sleeve and a corresponding limit step on the valve stem. During actual use, when the piston sleeve moves backward and needs to seal the second valve port, the piston sleeve is driven by the pilot fluid to move backward, and when it moves to the stop plate abutting the limit step, there is a liquid gap at the second valve port, and the first valve port is in a closed state. The limit step is blocked behind the stop plate. At this time, the piston sleeve pushes the valve stem to move backward together. Since the valve stem is subjected to liquid high pressure at the position of the first matching step before it is opened, with the help of the secondary high-pressure resistance It can generate forward resistance to the piston sleeve, thereby slowing down and buffering the piston sleeve from hitting the end of the second valve port; it can avoid the problem of instantaneous high pressure directly hitting the second valve port and causing damage when the piston sleeve closes the second valve port; at the same time, the liquid gap set at the second valve port can meet the requirement that when the valve stem opens the first valve port, the instantaneous high-pressure liquid from the first valve port rushes into the liquid gap of the second valve port, and plays a secondary buffering role in flushing the resistance of the piston sleeve in front of the second valve port. During operation, the two cooperate with each other to reduce the movement speed of the end of the piston sleeve, reduce the impact force on the valve port, and improve the operation reliability and service life of the valve string. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments:

[0016] Figure 1 This is a schematic structural diagram of a specific embodiment of the impact-resistant hydraulic control valve of the present invention;

[0017] Figure 2 for Figure 1 Diagram of the initial posture of the piston sleeve;

[0018] Figure 3 for Figure 2 Diagram of the fitting posture of the piston sleeve and the valve stem;

[0019] Figure 4 for Figure 2 The first valve port is open and the second valve port is closed;

[0020] Figure 5 for Figure 1 Schematic diagram of the structure of the piston sleeve.

[0021] Explanation of the accompanying symbols: 1-valve sleeve; 11-liquid inlet; 2-valve seat; 21-first valve port; 22-second valve port; 3-end sleeve; 31-return liquid port; 32-pilot control chamber; 33-pilot control hole; 4-screw plug; 5-valve stem; 51-liquid outlet; 52-connecting hole; 53-limiting step; 54-annular conical step; 6-piston sleeve; 61-main body; 62-conical fitting section; 63-equal diameter pre-fitting section; 64-annular step; 7-wire retaining ring; 8-spring; 9-liquid clearance. DETAILED DESCRIPTION

[0022] In order to make the technical objectives, technical solutions, and beneficial effects of the present invention more clear, the technical solutions of the present invention are further described below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. That is, the embodiments described herein are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and illustrated herein can be arranged and designed in various different configurations.

[0023] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be an intermediate element at the same time. The terms "first", "second" and similar words do not indicate any order, quantity or importance, but are only used to distinguish different components. The terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal communication of two elements, it can be directly connected, or it can be indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0025] The impact-resistant hydraulically controlled valve disclosed herein is primarily used in fully mechanized coal mining working faces. It is used in hydraulic support hydraulic valves to facilitate switching between two flow paths and control shutoffs. It is particularly suitable for hydraulically controlled check valves and hydraulically controlled reversing valves. It primarily addresses the problem of excessive movement of the piston at the end of the valve port, which can cause impact and wear on the valve port and piston sleeve 6.

[0026] The impact-resistant hydraulic control valve includes a valve body, a valve cavity is provided in the valve body, a valve stem 5 is elastically assembled with a guide in the valve cavity, a sliding sleeve is provided on the valve stem 5, a first liquid hole and a second liquid hole are provided on the valve body, a third liquid hole is provided on the valve body or the valve stem 5, a first valve port 21 for connecting the first liquid hole and the third liquid hole is provided on the valve body, and a second valve port 22 for connecting the second liquid hole and the third liquid hole is provided on the valve body, a pilot control cavity 32 is formed in the valve body at the front side of the piston sleeve 6, a first matching step is provided on the valve stem 5, and a second matching step is provided at the rear end of the piston sleeve 6. When the valve stem 5 moves forward, the first valve port 21 is blocked and the second valve port 22 is opened. When the valve stem 5 moves backward, the piston sleeve 6 blocks the second valve port 22 and opens the first valve port 21.

[0027] In the above-mentioned hydraulic control valve, the two liquid paths, one connecting the first liquid hole with the third liquid hole and the other connecting the second liquid hole with the third liquid hole, are switched by the action of the valve stem 5 and the piston sleeve 6.

[0028] In the embodiment, the electro-hydraulic controlled reversing valve is taken as an example for detailed description: Figures 1 to 5 As shown, the above-mentioned valve body includes a valve sleeve 1, a valve seat 2 and an end sleeve 3 which are coaxially threadedly connected from back to front. The valve seat 2 is located between the valve sleeve 1 and the end sleeve 3, and the rear side of the end sleeve 3 is connected to a screw plug 4. The front end of the end sleeve 3 is embedded in the inner hole of the screw plug 4 and is fixed by a wire retaining ring 7. The rear end of the end sleeve 3 is sleeved into the piston sleeve 6. The valve stem 5 is sleeved into the inner hole of the piston sleeve 6, and the valve stem 5 is guided and assembled in the valve sleeve 1.

[0029] Correspondingly, a liquid inlet hole is opened near the front end of the side wall of the valve sleeve 1, and the liquid inlet hole constitutes the above-mentioned first liquid hole. A liquid return hole is opened near the rear end of the side wall of the end sleeve 3, and the liquid return hole constitutes the above-mentioned second liquid hole. At the same time, a liquid outlet hole is opened inside the valve stem 5, and the liquid outlet hole constitutes the above-mentioned third liquid hole. A connecting hole 52 is opened on the side wall of the valve stem 5 at a position corresponding to the valve seat 2, which is used to connect the liquid outlet 51 with the liquid inlet 11 and the liquid return port 31.

[0030] In order to ensure the communication between the liquid inlet 11 and the liquid outlet 51, and between the return liquid port 31 and the liquid outlet 51, two conical valve ports are provided on the valve seat 2. The two conical valve ports are respectively arranged at the front and rear ends of the inner wall of the valve seat 2. The conical valve port located on the rear side is the first valve port 21, and the valve port located on the front side is the second valve port 22. The first valve port 21 is used to block the liquid inlet 11 and the liquid outlet 51, and the second valve port 22 is used to block the return liquid port 31 and the liquid inlet 11.

[0031] An annular conical step 54 is provided on the side wall of the valve stem 5, and a conical fitting section 62 is provided at the rear end of the piston sleeve 6, which is used to seal and fit with the first valve port 21 and the second valve port 22 respectively to block the first valve port 21 and the second valve port 22 respectively.

[0032] To achieve the purpose of blocking the first valve port 21, a return spring 8 is provided between the valve stem 5 and the valve sleeve 1 to drive the valve stem 5 forward, thereby blocking the valve stem 5 at the first valve port 21. To achieve the purpose of blocking the second valve port 22, a pilot control hole 33 is provided on the side wall of the end sleeve 3. A corresponding pilot control chamber 32 is formed in the end sleeve 3 in front of the piston sleeve 6. Pilot fluid enters the pilot control chamber 32 through the pilot control hole 33, thereby pushing the piston sleeve 6 and the valve stem 5 backward, thereby blocking the piston sleeve 6 at the second valve port 22.

[0033] In the actual flow path, when the controller outputs an electrical control signal, the electromagnetic pilot valve receives the signal, the electromagnet is energized, the pilot valve opens, the pilot fluid enters the pilot control chamber 32, and pushes the piston sleeve 6 and the valve stem 5 to move backward, and close the second valve port 22, open the first valve port 21, and the high-pressure fluid enters the valve chamber through the opened liquid inlet 11. Under the action of the high-pressure fluid, the valve stem 5 and the piston sleeve 6 overcome the pressure of the liquid inlet 11 (connected to the high-pressure fluid of the pump station) and the force of the spring 8 and are pushed backward. At this time, the piston sleeve 6 and the valve seat 2 close the second valve port 22 to block the return fluid. At the same time, the valve stem 5 and the valve seat 2 open the first valve port 21, and the high-pressure fluid in the liquid inlet 11 enters the liquid outlet 51 through the opened channel, and then enters the hydraulic support jack, realizing the liquid supply to the hydraulic support jack.

[0034] When the controller outputs a reverse electric control signal, the solenoid pilot valve receives the signal, the electromagnet loses power, and the piston sleeve 6 and valve stem 5 move forward under the thrust of the spring 8, closing the first valve port 21 and opening the second valve port 22. At this time, the return port 31 is connected to the liquid outlet 51, and the high-pressure liquid in the jack flows back into the valve cavity through the liquid outlet 51, enters the return port 31 through the second valve port 22, and flows back to the pump box through the return port 31, realizing the return of liquid to the hydraulic support jack. In this way, the hydraulic circuit reversing control of the reversing valve is realized.

[0035] During the process of closing the second valve port 22, the movement of the piston sleeve 6 and the valve stem 5 is instantaneous, and the end movement speed is relatively fast. To avoid the problem of the piston sleeve 6 and the second valve port 22 being blocked by the piston sleeve 6 due to the excessively fast movement speed, resulting in a strong collision with the second valve port 22 and thus damaging the valve port, a double buffer structure is provided between the piston sleeve 6 and the second valve port 22. Specifically, a stopper is provided on the piston sleeve 6, and a limiting step 53 is provided on the valve stem 5 in the rearward movement path of the stopper. The limiting step 53 and the stopper are engaged in a forward and backward stoppering motion, so that the piston sleeve 6 pushes the valve stem 5 to move backward synchronously.

[0036] Among them, the dimensions of the convex edge and the limiting step 53 meet the following requirements: when the first valve port 21 of the valve body is closed and the piston sleeve 6 is driven by the pilot fluid to move backward to abut against the limiting step 53, a liquid gap 9 of a set size is formed between the second mating step and the corresponding second valve port 22, so that the piston sleeve 6 pushes the valve stem 5 to open the first valve port 21 before blocking the second valve port 22.

[0037] Specifically, the rib is positioned at the front end of the piston sleeve 6 and comprises an annular step 64 formed by folding radially inward from the front end of the piston sleeve 6. The valve stem 5 comprises a small-diameter section at the front end and a large-diameter section at the rear end. The limiting step 53 comprises a step of varying diameter formed between the large-diameter and small-diameter sections. The liquid-passing gap 9 is preferably set to a size of 1-2 mm, preferably 1.5 mm.

[0038] In actual use, when the second valve port 22 needs to be closed, Figure 2 As shown, the pilot fluid enters the pilot control chamber 32 and pushes the valve stem 5 and the piston sleeve 6 backward. Since the piston sleeve 6 is slidably assembled on the valve stem 5, and the valve stem 5 is pushed by the return spring 8 and the high pressure of the liquid at the liquid inlet 11, in the initial state, the piston sleeve 6 moves backward before the valve stem 5. When the piston sleeve 6 moves to the position where the rear end annular step 64 of the piston sleeve 6 is in contact with the limit step 53 of the valve stem 5, the piston sleeve 6 moves backward. Figure 3As shown, at this time, the liquid clearance 9 at the second valve port 22 is 1.5mm. In this instantaneous posture, the rear end annular step 64 of the piston sleeve 6 is pushed by the limiting step 53 of the valve stem 5 to achieve a buffer, which initially reduces the speed of the piston sleeve 6; then the high-pressure pilot liquid in the pilot control chamber 32 overcomes the high pressure at the liquid inlet 11 and the force of the return spring 8 to push the piston sleeve 6 and the valve stem 5 backward to move synchronously. In this process, when the second valve port 22 is not closed, the annular conical step 54 on the valve stem 5 breaks away from the seal with the first valve port 21 and opens the first valve port 21. The high-pressure liquid at the liquid inlet 11 instantly flows into the liquid clearance 9 of the second valve port 22 and flushes the conical surface fitting section 62 of the piston sleeve 6. At this time, the high-pressure return liquid jumps and generates a flushing resistance on the conical surface fitting section 62 of the piston sleeve 6 again, which can effectively slow down the instantaneous speed of the end of the backward movement of the piston rod and the valve stem 5 again, achieving a secondary buffer. Finally, the second valve port is closed and the first valve port is opened. Figure 4 shown.

[0039] By setting the liquid gap 9, secondary buffering of the piston sleeve 6 can be achieved, effectively reducing the instantaneous speed when the piston sleeve 6 and the second valve port 22 are blocked, avoiding strong collision between the two and causing damage to the conical surface matching section 62 of the valve port and the piston sleeve 6.

[0040] In addition, in this embodiment, in order to meet the high-pressure resistance in the case of a small amount of return liquid and achieve gap throttling, the above-mentioned piston sleeve 6 includes a main body 61 section and a conical diameter-reducing section connected to the rear end of the main body 61 section. The conical diameter-reducing section constitutes the above-mentioned conical surface fitting section 62. The rear end of the conical surface fitting section 62 is connected to a constant diameter pre-fitting section 63. The outer diameter of the constant diameter pre-fitting section 63 is smaller than the inner diameter of the valve seat 2, so that part of the liquid enters the return liquid port 31 from the liquid inlet 11. Preferably, there is a gap fit between the pre-fitting section and the valve seat 2. This can not only meet the small amount of return liquid and slow down the terminal speed of the piston sleeve 6, but also prevent excessive liquid from flowing back from the return liquid port 31 and affecting the normal flow of the first valve port 21.

[0041] Of course, in other embodiments, the stop can be set at the front end of the piston sleeve 6, or on the inner wall of the piston sleeve 6, and a corresponding limiting groove is set at the corresponding position of the valve stem 5, and the rear side groove wall of the limiting groove constitutes a limiting step 53.

[0042] In other embodiments, the stop platform may also be designed as an additional component fixedly connected to the piston sleeve 6, which is not specifically limited.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate and not to limit the technical solutions of the present invention. Any equivalent substitutions of the present invention and any modifications or partial substitutions that do not depart from the spirit and scope of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. An impact-resistant hydraulic control valve, comprising a valve body, a valve cavity within the valve body, a valve stem elastically mounted in the valve cavity, a sliding sleeve on the valve stem provided with a piston sleeve, a first liquid hole and a second liquid hole provided on the valve body, a third liquid hole provided on the valve body or the valve stem, a first valve port for connecting the first liquid hole and the third liquid hole, and a second valve port for connecting the second liquid hole and the third liquid hole, a pilot control cavity being formed in the valve body at the front side of the piston sleeve, a first matching step being provided on the valve stem, and a second matching step being provided at the rear end of the piston sleeve, the first valve port being blocked and the second valve port being opened when the valve stem moves forward, and the second valve port being blocked and the first valve port being opened when the valve stem moves backward; and The piston sleeve is provided with a stop platform, and the valve stem is provided with a limiting step on the backward moving path of the stop platform. The limiting step and the stop platform are stopped and limited in front and behind so that the piston sleeve pushes the valve stem to move backward synchronously; the size of the convex edge and the limiting step meets the following requirements: when the first valve port of the valve body is closed and the piston sleeve is driven by the pilot fluid to move backward to abut against the limiting step, a liquid gap of a set size is formed between the second mating step and the corresponding second valve port, so that the piston sleeve first pushes the valve stem to open the first valve port when the second valve port is not blocked.

2. The shock-resistant hydraulic control valve according to claim 1, characterized in that: The stop platform is arranged at the front end of the piston sleeve.

3. The shock-resistant hydraulic control valve according to claim 2, characterized in that: The stop is composed of an annular step formed by folding radially inward from the front end of the piston sleeve, the valve stem includes a small diameter section at the front end and a large diameter section at the rear end, and the limiting step is composed of a diameter-changing step formed between the large diameter section and the small diameter section.

4. The shock-resistant hydraulic control valve according to claim 2, characterized in that: The set size of the liquid gap is 1-2 mm.

5. The shock-resistant hydraulic control valve according to claim 2, characterized in that: The first valve port and the second valve port are both conical valve ports, the first liquid hole is the liquid inlet, the second liquid hole is the liquid return port, the third liquid hole is the liquid outlet arranged on the valve stem, and the first matching step and the second matching step are both conical steps.

6. The shock-resistant hydraulic control valve according to claim 5, characterized in that: The piston sleeve includes a main body section and a conical reducing section connected to the rear end of the main body section, the conical reducing section constitutes the second fitting step, and the rear end of the conical reducing section is connected to an equal diameter pre-fitting section, the outer diameter of the equal diameter pre-fitting section is smaller than the inner diameter of the valve seat, so that part of the liquid enters the liquid return port from the liquid inlet.

7. The shock-resistant hydraulic control valve according to claim 6, characterized in that: The equal-diameter pre-fitting section and the valve seat are clearance-fitted.

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