Valve element of hydraulic valve, hydraulic valve and hydraulic control system

Abstract

The utility model discloses a valve core of a hydraulic valve, the hydraulic valve and a hydraulic control system. The shoulder closed end is coaxially connected with the valve element body section, the circumferential face is used for being attached to and sealed with the wall face of a sliding way of a valve body of the hydraulic valve, and the diameter of the shoulder closed end is larger than that of the valve element body section. The closed end of the shoulder is provided with a throttling groove, the throttling groove is a triangular groove formed in the axial direction of the closed end of the shoulder, and the groove bottom of the triangular groove in the axial direction is the vertex angle of a triangle. A baffle is formed between every two adjacent throttling grooves, a communicating gap is formed between the side, close to the valve element body section in the radial direction, of each baffle and the valve element body section, and every two adjacent throttling grooves communicate through the corresponding communicating gap. According to the hydraulic control system, the triangular throttling groove is adopted in the valve element, the vertex angle of the throttling valve is firstly opposite to the oil outlet, small flow is achieved when the valve element is small in opening degree, the area change of the vertex angle of the triangle is very small, and therefore the problem of starting impact caused by too fast flow change in the initial starting stage of the hydraulic control system is solved. And the problem of starting impact caused by too fast flow change in the initial starting stage of the hydraulic control system is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of hydraulic devices, in particular to a valve core of a hydraulic valve, a hydraulic valve and a hydraulic control system. Background Art

[0002] Directional valves are widely used as hydraulic components that control the opening and closing of oil circuits and the direction of reversing. When a directional valve is in operation, the valve core slides within the valve body, achieving the valve core reversal, connecting or closing different oil ports.

[0003] The working characteristics of the hydraulic control system depend to a large extent on the cylindrical slide valve, and the shape of the throttle groove of the cylindrical slide valve determines the flow control performance of the hydraulic cylindrical slide valve.

[0004] At present, there are many shapes of throttle grooves. However, the current throttle groove shapes will result in poor flow curve characteristics through the reversing valve during the startup of the hydraulic control system. That is, the flow has a large slope change when the valve core is slightly opened, resulting in a large flow through the reversing valve during the startup of the hydraulic control system, causing the hydraulic force to impact the valve core, affecting the operator's experience; in addition, the current flow curve characteristics through the reversing valve will have inflection points at certain positions during the movement of the valve core, reducing the efficiency of the overall machine debugging and resulting in increased overall machine costs.

[0005] Therefore, how to provide a valve core of a hydraulic valve to reduce the flow change when the valve core is small and alleviate the impact of the hydraulic force on the valve core during the startup process is a technical problem that needs to be solved urgently by skilled technicians. Utility Model Content

[0006] In view of this, the present invention provides a spool for a hydraulic valve that reduces flow rate variation when the spool is slightly opened, thereby alleviating the impact of hydraulic force on the spool during startup. Furthermore, the present invention provides a hydraulic valve having the spool and a hydraulic control system having the hydraulic valve.

[0007] To achieve the above objectives, the present invention provides the following technical solutions:

[0008] A valve core of a hydraulic valve, comprising:

[0009] Valve core main body section;

[0010] A shoulder closed end, the shoulder closed end being coaxially connected to the valve core main body section, the circumferential surface of the shoulder closed end being used to fit and seal with the wall surface of the slideway of the valve body of the hydraulic valve, and the diameter of the shoulder closed end being larger than the diameter of the valve core main body section;

[0011] The closed end of the shoulder has a throttling groove, which is a triangular groove arranged axially along the closed end of the shoulder, and the bottom of the triangular groove along the axial direction is the vertex angle of the triangle; a baffle is formed between adjacent throttling grooves, and a connecting gap is formed between the baffle and the valve core main body section on one side radially close to the valve core main body section, and the adjacent throttling grooves are connected through the connecting gap.

[0012] Preferably, in the valve core of the above-mentioned hydraulic valve, the volume of the communication gap gradually increases along a first direction, and the first direction is a direction from the groove bottom to the groove opening of the throttling groove along the axial direction.

[0013] Preferably, in the valve core of the above-mentioned hydraulic valve, a side surface of the baffle radially close to the valve core main section is an inclined arc surface, and the inclined direction of the inclined arc surface is: the inclined arc surface gradually moves away from the valve core main section along the first direction.

[0014] Preferably, in the valve core of the above-mentioned hydraulic valve, the radial thickness of the baffle gradually decreases along the first direction.

[0015] Preferably, in the valve core of the above-mentioned hydraulic valve, an annular groove is provided at the connection between the shoulder closed end and the valve core main body section, the axial depth of the annular groove on the shoulder closed end is greater than the axial depth of the throttling groove on the shoulder closed end, and the annular groove, the throttling groove and the connecting gap are all connected.

[0016] Preferably, in the valve core of the above-mentioned hydraulic valve, there are multiple throttling grooves, which are distributed along the circumference of the closed end of the shoulder.

[0017] Preferably, in the valve core of the above-mentioned hydraulic valve, the number of the shoulder closed ends is two and they are symmetrically arranged with respect to the valve core main body section.

[0018] A hydraulic valve comprises a valve core and a valve body, wherein the valve core is the valve core described in any one of the above items, and the valve core is installed in a slide of the valve body and can slide along the slide, and during the axial movement of the valve core, the throttling groove of the valve core can be connected to the oil outlet.

[0019] Preferably, in the above hydraulic valve, both ends of the valve core are provided with the shoulder closed ends, and both ends of the valve body are provided with oil outlets, and the valve core can be connected with one of the two oil outlets during movement;

[0020] The valve core main body section of the valve core is opposite to the oil inlet of the valve body.

[0021] A hydraulic control system includes a hydraulic valve, wherein the hydraulic valve is the hydraulic valve described above.

[0022] The present invention discloses a hydraulic valve spool in an embodiment, which utilizes a triangular throttling groove. During the movement of the spool, the top corner of the throttling valve first faces the oil outlet, that is, the small opening of the throttling groove is connected to the oil outlet, thereby achieving a small flow rate when the spool is slightly opened. Furthermore, as the spool continues to move, the area of ​​the triangular throttling groove relative to the oil outlet gradually increases, thereby avoiding the startup shock problem caused by excessively rapid flow changes during the initial startup of the hydraulic control system. In addition, in the present application, a connecting gap is provided between the baffle and the main section of the spool, and the connecting gap is connected to the throttling groove. The connecting gap can be used to reduce the pressure of the oil rushing in from the oil inlet, thereby further reducing the startup shock problem. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 This is a schematic structural diagram of a hydraulic valve disclosed in an embodiment of the present utility model;

[0025] Figure 2 A perspective view of a hydraulic valve disclosed in an embodiment of the present utility model;

[0026] Figure 3 This is a front cross-sectional view of the hydraulic valve disclosed in the embodiment of the present utility model;

[0027] Figure 4 This is a structural schematic diagram of the valve core of the hydraulic valve disclosed in the embodiment of the present utility model;

[0028] Figure 5 This is a schematic structural diagram of the valve core of the hydraulic valve disclosed in an embodiment of the present utility model in another direction;

[0029] Figure 6 This is a front view of the valve core of the hydraulic valve disclosed in the embodiment of the present utility model;

[0030] Figure 7 for Figure 6 Cross-sectional view in the AA direction;

[0031] Figure 8 This is a structural schematic diagram of the hydraulic valve disclosed in an embodiment of the present utility model after the valve core moves to the right;

[0032] Figure 9 It is an equivalent shape of the throttle groove and the oil outlet disclosed in the embodiment of the present utility model;

[0033] Figure 10 This is a relationship diagram between the valve core movement distance and the equivalent area of ​​the valve core disclosed in the embodiment of the present utility model. DETAILED DESCRIPTION

[0034] The utility model discloses a valve core of a hydraulic valve, which reduces flow rate variation when the valve core is slightly opened, thereby alleviating the impact of hydraulic force on the valve core during startup. In addition, the utility model also discloses a hydraulic valve having the valve core and a hydraulic control system having the hydraulic valve.

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0036] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the quantity of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features.

[0037] Directional valves are widely used as hydraulic components that control the opening and closing of oil circuits and the direction of reversing. When a directional valve is in operation, the valve core slides within the valve body, achieving the valve core reversal, connecting or closing different oil ports.

[0038] The working characteristics of the hydraulic control system depend to a large extent on the cylindrical slide valve, and the shape of the throttle groove of the cylindrical slide valve determines the flow control performance of the hydraulic cylindrical slide valve.

[0039] At present, there are many shapes of throttle grooves. However, the current throttle groove shapes will result in poor flow curve characteristics through the reversing valve during the startup of the hydraulic control system. That is, the flow has a large slope change when the valve core is slightly opened, resulting in a large flow through the reversing valve during the startup of the hydraulic control system, causing the hydraulic force to impact the valve core, affecting the operator's experience; in addition, the current flow curve characteristics through the reversing valve will have inflection points at certain positions during the movement of the valve core, reducing the efficiency of the overall machine debugging and resulting in increased overall machine costs.

[0040] Based on the above technical problems, this application discloses a valve core of a hydraulic valve, which sets the shape of the throttle valve to reduce the flow change when the valve core is small, thereby alleviating the problem of the impact of the hydraulic force on the valve core during the startup process.

[0041] The hydraulic valves in this application include but are not limited to reversing valves. Any valve that requires the valve core to move to achieve liquid conduction is within the scope of protection. This application uses the reversing valve as an example for explanation. Other valve structures can be found in the following description.

[0042] Specific, combined Figures 1 to 3 As shown, the hydraulic valve disclosed in the embodiment of the present application includes a valve body 1 and a valve core 2.

[0043] The valve body 1 includes but is not limited to a rectangular shell, with a first oil outlet 12 and a second oil outlet 13 on one side of the valve body 1, and an oil inlet 11 on the other side of the valve body 1. The valve core 2 is located in the middle of the valve body 1, and the valve core 2 can move in the valve body 1 in the axial direction of the valve core 2. It should be noted that the position of the valve body 1 used to set the valve core 2 is a slide (not marked in the figure), that is, the valve core 2 moves in the slide, and the first oil outlet 12, the second oil outlet 13 and the oil inlet 11 are all channels set by the valve core 2 on both sides of the slide in the radial direction. When the valve core 2 is not set in the valve body 1, the first oil outlet 12, the second oil outlet 13 and the oil inlet 11 are all connected to the slide; after the valve core 2 is set in the valve body 1, the valve core 2 is in sealing contact with the wall of the slide, which can achieve the blocking of the first oil outlet 12 and the second oil outlet 13. However, as the valve core 2 moves, the first oil outlet 12 and the second oil outlet 13 can be communicated with the oil inlet 11 respectively.

[0044] The following Figure 3 Taking the direction in FIG. 1 as an example, the manner of switching the first oil outlet 12 and the second oil outlet 13 to be connected to the oil inlet during the movement of the valve core 2 is described.

[0045] along Figure 3 Pushing the valve core 2 to the right can connect the oil inlet 11 with the second oil outlet 13 , and pushing the valve core 2 to the left can connect the oil inlet 11 with the first oil outlet 12 .

[0046] For the communication between the oil inlet 11 and the first oil outlet 12 and between the oil inlet 11 and the second oil outlet 13, please refer to Figure 4 and Figure 5 The throttle groove on the valve core 2 shown in FIG.

[0047] Specifically, Figure 4 and Figure 5 The valve core 2 includes a valve core main body section 22 and a shoulder closed end 21.

[0048] The shoulder-enclosed end 21 is coaxially connected to the valve core main section 22. Optionally, the shoulder-enclosed end 21 and the valve core main section 22 are integrally formed. The circumferential surface of the shoulder-enclosed end 21 is configured to form a seal with the wall surface of the slideway of the hydraulic valve body 1, thereby sealing the first oil outlet 12 and the second oil outlet 13. Specifically, the diameter of the shoulder-enclosed end 21 is larger than the diameter of the valve core main section 22. The diameter of the shoulder-enclosed end 21 only needs to match the slideway of the valve body 1. The corresponding diameter of the valve core main section 22 can be set according to different needs and is not specifically limited here.

[0049] The shoulder closed end 21 has a throttling groove 211 and a baffle 212 .

[0050] The throttling groove 211 is a triangular groove arranged axially along the closed shoulder end 21, with the bottom of the triangular groove along the axial direction being the vertex of the triangle. The throttling groove 211 extends radially along the closed shoulder end 21 until it is flush with the surface of the valve core main section 22. This can be understood as: the throttling groove 211 is a triangular groove excavated radially at the step formed by the cylindrical closed shoulder end 21 and the valve core main section 22.

[0051] Due to the provision of the throttle grooves 211, baffles 212 are formed between adjacent throttle grooves 211 on the closed end 21 of the shoulder. In the present application, an axially extending groove is excavated between the baffles 212 and the valve core main section 22. That is, a communication gap 213 is formed between the side of the baffle 212 radially close to the valve core main section 22 and the valve core main section 22. The communication gap 213 is connected to the throttle grooves 211, thereby forming a circumferential flow space.

[0052] Combine Figures 3 to 5 As shown, after the valve core 2 is installed in the valve body 1, the shoulder closed end 21 is in contact with the circumferential inner wall of the slideway of the valve body 1, thereby blocking the first oil outlet 12 and the second oil outlet 13. The valve core main section 22 is connected to the oil inlet 11. After the oil enters the oil inlet 11 and flows through the throttle groove 211 and the communication gap 213, it flows out through the throttle groove 211 of the shoulder closed end 21.

[0053] It can be understood that, in the initial state of the hydraulic valve, the throttle groove 211 is located between the oil outlet and the oil inlet in the axial direction of the valve core 2 .

[0054] In combination with the above-mentioned configuration, it can be seen that the valve core 2 of the hydraulic valve in the present application adopts a triangular throttling groove 211. During the movement of the valve core 2, the top corner of the throttling groove 211 first faces the oil outlet (the first oil outlet 12 or the second oil outlet 13), that is, the small opening of the throttling groove 211 is connected to the oil outlet, thereby achieving a small flow rate when the valve core is slightly opened. In addition, during the continuous movement of the valve core 2, the area of ​​the triangular throttling groove 211 relative to the oil outlet gradually increases, and the area change at the top corner of the triangle is very small, thereby avoiding the startup shock problem caused by excessively rapid flow changes in the initial startup of the hydraulic control system. In addition, in the present application, a connecting gap 213 is set between the baffle 212 and the valve core main section 22, and the connecting gap 213 is connected to the throttling groove 211. The connecting gap 213 can be used to reduce the pressure of the oil rushing in from the oil inlet 11, thereby further reducing the startup shock problem.

[0055] from Figure 4 It can be seen that there is space between the baffle 212 and the valve core main section 22 in the radial direction, and the volume of the connecting gap 213 gradually increases along the first direction. Specifically, the first direction is defined in this application as the direction from the axial bottom of the throttling groove 211 to the groove mouth.

[0056] In this application, the volume of the baffle communication gap 213 is configured to gradually increase along the first direction. This can be understood as gradually decreasing the volume of the communication gap 213 in the axial direction of the valve core 2 from the oil inlet 11 toward the first oil outlet 12. This allows the oil rushing in from the oil inlet 11 to be quickly buffered, which helps to reduce the impact force of the oil, that is, reduce the hydraulic force. In addition, during the movement of the valve core 2, the oil at the small volume end enters the oil outlet through the throttle groove 211, which can reduce the flow rate when the valve core is at a small opening. As the valve core 2 moves, the area of ​​the triangular throttle groove 211 relative to the oil outlet gradually increases, avoiding the startup shock problem caused by excessively rapid flow changes during the initial startup of the hydraulic control system.

[0057] In some embodiments, to achieve volume changes in the communication gap 213, a side surface of the baffle 212 radially proximal to the valve core main section 22 is configured as an inclined arc surface, with the inclined arc surface being inclined such that, along a first direction, the inclined arc surface gradually moves away from the valve core main section 22. It can be understood that the distance between the first end of the baffle 212 and the valve core main section 22 is greater than the distance between the second end of the baffle 212 and the valve core main section 22. The first end of the baffle 212 is located on the same side as the notch of the throttling groove 211, and the second end of the baffle 212 is located on the same side as the bottom of the throttling groove 211.

[0058] To achieve an inclined arcuate surface on the side of the communication baffle 212 radially proximate to the valve core main section 22, in some embodiments, the baffle 212 can have a variable radial thickness. Specifically, the outer surface of the baffle 212 is a circular arc surface that aligns with the circumferential surface of the slideway, and the thickness of the baffle 212 gradually decreases along a first direction in the radial direction, thereby forming an inclined arcuate surface on the side of the baffle 212 proximate to the valve core main section 22.

[0059] In some embodiments, two closed shoulder ends 21 are symmetrically arranged about the valve core main section 22. Each closed shoulder end 21 corresponds to an oil outlet. When the hydraulic valve is not in operation, the two closed shoulder ends 21 are located between the first oil outlet 12 and the second oil outlet 13. As the valve core 2 moves, the throttle grooves 211 on the closed shoulder ends 21 communicate with the corresponding oil outlets.

[0060] In some embodiments, there are multiple throttling grooves 211 on the shoulder closed end 21 , and the throttling grooves 211 are distributed along the circumference of the shoulder closed end 21 . Exemplarily, the throttling grooves 211 are evenly distributed along the circumference of the shoulder closed end 21 .

[0061] Combine Figure 6 and Figure 7 As shown, an annular groove 214 is provided at the connection between the shoulder closed end 21 and the valve core main body section 22 disclosed in the embodiment of the present application. The axial depth of the annular groove 214 on the shoulder closed end 21 is greater than the axial depth of the throttle groove 211 on the shoulder closed end 21. It should be noted that the axial depth of the throttle groove 211 on the shoulder closed end 21 is the dimension of the throttle groove 211 extending in the axial direction on the shoulder closed end 21, and this dimension is the same as the dimension of the baffle 212 extending in the axial direction.

[0062] During the processing of the valve core 2, a triangular throttling groove 211 can be opened on the side of the cylindrical shoulder closed end 21 near the valve core main section 22, with the throttling groove 211 having a depth along the radial direction of the shoulder closed end 21. Then, a wedge-shaped space, i.e., a connecting gap 213, is machined axially at the baffle 212 formed between adjacent throttling grooves 211, so that adjacent throttling grooves 211 are connected through the connecting gap 213. Finally, an annular groove 214 is excavated on the radial bottom of the throttling groove 211, away from the valve core main section 22, and circumferentially around the valve core main section 22. The annular groove 214, the throttling groove 211, and the connecting gap 213 are all connected, which is equivalent to increasing the axial dimension of the throttling groove 211.

[0063] The basic formula for calculating steady-state fluid force is: F = p*q*v*cosα, where F is the fluid force, p is the oil pressure differential, q is the liquid density, v is the fluid velocity, and α is the jet angle. This formula shows that the fluid force is related to the jet angle, and the larger the jet angle, the smaller the fluid force.

[0064] See also Figure 8 As shown, the valve core 2 in the present application increases the axial size of the throttle groove 211 by adding the annular groove 214, so that the jet angle when the valve core 2 supplies oil to the oil outlet through the throttle groove 211 is increased, thereby reducing the liquid force flowing through the valve core 2 in the present application.

[0065] The following combination Figure 9 and Figure 10 The relationship between the equivalent area of ​​the throttle groove 211 and the oil outlet when the valve core 2 is moving will be described.

[0066] During the process of the throttle groove 211 and the oil outlet gradually becoming opposite to each other, the equivalent shape of the connection between the throttle groove 211 and the oil outlet can be: Figure 9 The triangle shape in the.

[0067] Combine Figure 10 It can be seen that when the displacement of the valve core 2 is less than 2 mm, as the displacement of the valve core 2 increases, the area of ​​the throttle groove 211 relative to the oil outlet gradually increases, and the flow through the valve core 2 changes in a small slope. The valve core 2 realizes a small opening transition to avoid startup shock.

[0068] When the displacement of the valve core 2 is greater than 2mm, the equivalent area of ​​the valve core 2 is the triangular opening area formed by the valve core 2 and the valve body 1. According to Q=K*S*(△P) (1 / 2) , where Q is the flow rate, K is a constant value, and △P is the pressure loss value. When △P is constant, the flow rate Q is proportional to the equivalent opening area S of the valve core 2. That is, as the valve core 2 moves, the equivalent area of ​​the valve core 2 is proportional to the displacement of the valve core 2, that is, the linear change of the flow curve is achieved, thereby improving the debugging efficiency of the whole machine and reducing costs.

[0069] In addition, the present application also discloses a hydraulic control system, including a hydraulic valve, wherein the hydraulic valve is the hydraulic valve disclosed in the above embodiment. Therefore, the hydraulic control system with the hydraulic valve also has all the above technical effects, which will not be repeated here.

[0070] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0071] The above description of the disclosed embodiments will enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A valve core of a hydraulic valve, characterized in that: include: Valve core main body section; A shoulder closed end, the shoulder closed end being coaxially connected to the valve core main body section, the circumferential surface of the shoulder closed end being used to fit and seal with the wall surface of the slideway of the valve body of the hydraulic valve, and the diameter of the shoulder closed end being larger than the diameter of the valve core main body section; The closed end of the shoulder has a throttling groove, which is a triangular groove arranged axially along the closed end of the shoulder, and the bottom of the triangular groove along the axial direction is the vertex angle of the triangle; a baffle is formed between adjacent throttling grooves, and a connecting gap is formed between the baffle and the valve core main body section on one side radially close to the valve core main body section, and the adjacent throttling grooves are connected through the connecting gap.

2. The valve core of the hydraulic valve according to claim 1, characterized in that: The volume of the communication gap gradually increases along a first direction, where the first direction is a direction from the groove bottom to the groove opening of the throttling groove along the axial direction.

3. The valve core of the hydraulic valve according to claim 2, characterized in that: A side surface of the baffle close to the valve core main body section in the radial direction is an inclined arc surface, and the inclined arc surface is inclined in the first direction and gradually moves away from the valve core main body section.

4. The valve core of the hydraulic valve according to claim 3, characterized in that: The baffle has a radial thickness that gradually decreases along a first direction.

5. The valve core of the hydraulic valve according to claim 1, characterized in that: An annular groove is provided at the connection between the shoulder closed end and the valve core main body section, the axial depth of the annular groove on the shoulder closed end is greater than the axial depth of the throttling groove on the shoulder closed end, and the annular groove, the throttling groove and the connecting gap are all connected.

6. The valve core of the hydraulic valve according to any one of claims 1 to 5, characterized in that: There are multiple throttling grooves, which are distributed along the circumference of the closed end of the shoulder.

7. The valve core of the hydraulic valve according to claim 6, characterized in that: There are two shoulder closed ends, which are symmetrically arranged about the valve core main body section.

8. A hydraulic valve comprising a valve core and a valve body, characterized in that: The valve core is the valve core as described in any one of claims 1 to 7, and the valve core is installed in the slide of the valve body and can slide along the slide. During the axial movement of the valve core, the throttling groove of the valve core can be connected to the oil outlet.

9. The hydraulic valve according to claim 8, characterized in that Both ends of the valve core are provided with the shoulder closed ends, and both ends of the valve body are provided with oil outlets, and the valve core can be connected with one of the two oil outlets during movement; The valve core main body section of the valve core is opposite to the oil inlet of the valve body.

10. A hydraulic control system comprising a hydraulic valve, characterized in that: The hydraulic valve is the hydraulic valve according to claim 8 or 9.

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