An electro-hydraulic control valve capable of adjusting flow gain

Abstract

The present invention discloses an electro-hydraulic control valve with adjustable flow gain. The control valve includes an upper valve body, a lower valve body, an upper pressure compensation plate, a lower pressure compensation plate, a valve core, an oil inlet channel, an oil outlet channel, and an oil return channel. A first guide constraint mechanism for driving the valve core to move in the left-right direction and a second guide constraint mechanism for driving the valve core to move in the front-back direction are respectively provided around the valve core. When the first guide constraint mechanism and the second guide constraint mechanism push the valve core to perform a compound motion in two degrees of freedom, the opening area gradient of the valve core valve port can be continuously changed, thereby changing the flow gain and achieving regulation of the flow gain of the control valve. The present invention solves the technical problems in the prior art where the flow gain of electro-hydraulic control valves is limited by their own mechanical structure or the flow gain control system is bulky and complex to control, thereby achieving the beneficial effect of greatly improving the dynamic performance of the electro-hydraulic control system.

Description

Technical Field

[0001] The present application relates to the field of fluid transmission and control, and in particular to an electro-hydraulic control valve with adjustable flow gain. Background Art

[0002] Industrial technology has advanced rapidly in recent years, and electro-hydraulic control systems are widely used in various fields such as industrial manufacturing, shipbuilding, metallurgy, and engineering machinery. As the core component of electro-hydraulic control systems, the flow characteristics, stability, and reliability of hydraulic valves directly determine the quality of the entire system. With the increasing variety and application of hydraulic equipment, its operation often requires a variety of operating conditions, thus placing increasingly high demands on the output performance of electro-hydraulic control systems. The transfer function of a typical electro-hydraulic control system shows that the flow gain of an electro-hydraulic control valve (electro-hydraulic proportional or servo valve) directly affects the system's open-loop gain, and thus the system's control performance.

[0003] Currently, there are two main ways to change the flow gain: the first is to make the valve port area gradient change with the valve port opening; the second is to use multi-valve parallel control. The first method generally provides a throttling notch in the shape of a semicircular, V-shaped, inverted V-shaped, trapezoidal or other combination on the valve core or valve sleeve, so that when the valve core moves in one degree of freedom, the minimum flow area of ​​the valve port changes with the change of the area gradient. However, this method is limited by the mechanical structure of the valve core or valve sleeve after the valve is processed, and it is impossible to achieve controllable and adjustable flow gain in engineering applications. The second method requires multiple groups of electro-hydraulic control valves (electro-hydraulic proportional or servo valves) to collaboratively control the same actuator. Each valve is independently controlled to achieve multi-stage adjustment, which can meet the requirements of flow gain switching and change, but the combination valve is large in size and the control system is complex.

[0004] Therefore, the electro-hydraulic control valve in the above-mentioned prior art has at least the following technical problems: the flow gain is limited by its own mechanical structure or the flow gain control system is bulky and complex to control.

[0005] Application Contents

[0006] The embodiment of the present application provides an electro-hydraulic control valve with adjustable flow gain, so as to solve the technical problems in the prior art that the flow gain of the electro-hydraulic control valve is limited by its own mechanical structure or the flow gain control system is bulky and complex to control. The embodiment of the present application forms an oil inlet channel, an oil outlet channel and an oil return channel by setting an upper pressure compensation plate, a valve core and a lower pressure compensation plate stacked up and down, and when the valve core deviates on the horizontal plane, the valve port area gradient connecting the oil inlet channel and the oil outlet channel will change; by setting a first guide constraint mechanism that can drive the valve core to move left and right and a second guide constraint mechanism that drives the valve core to move forward and backward, the valve core is pushed to perform a compound motion in two degrees of freedom directions, continuously changing the opening area gradient of the valve core valve port, thereby changing the flow gain and realizing the regulation of the flow gain of the control valve. Since the first guide constraint mechanism and the second guide constraint mechanism of the embodiment of the present application control and adjust the originally fixed flow gain of the control valve based on normal flow or pressure control of a single control valve, not only the flow gain of the control valve is no longer limited by its own mechanical structure, but the control mechanism has a simple structure and a small size, which greatly improves the dynamic performance of the electro-hydraulic control system. Moreover, since the continuity of the continuous curve flow regulation of the valve port is good, there is no obvious transient impact of the fluid during the switching process. In addition, the upper and lower clearances of the valve core are reduced under the action of pressure compensation through the pressure compensation plate, thereby reducing leakage, which can effectively improve the control accuracy of the control valve.

[0007] To solve the above problems, an embodiment of the present application provides an electro-hydraulic control valve with adjustable flow gain. The hydraulic valve includes an upper valve body and a lower valve body fixedly connected to each other in an upper and lower direction. A groove is provided on the lower surface of the upper valve body. An upper pressure compensation plate and a lower pressure compensation plate are provided in the groove from top to bottom, each of which can only move up and down.

[0008] A valve core is provided between the upper pressure compensation plate and the lower pressure compensation plate, and a first guide constraint mechanism for driving the valve core to move in the left-right direction and a second guide constraint mechanism for driving the valve core to move in the front-back direction are provided around the valve core;

[0009] The first guide constraint mechanism includes a first electro-mechanical converter and a first constraint, both of which are arranged opposite to each other in the left and right directions, the first electro-mechanical converter being located outside the upper valve body and fixed on the left side of the upper valve body; the first electro-mechanical converter has a first driving rod extending horizontally to the right and penetrating into the groove, and the first driving rod abuts against the left side of the valve core to drive the valve core to move in the left and right directions; the first constraint includes a first baffle and a first spring push rod, the first baffle is fixed to the right side of the upper valve body, the first spring push rod horizontally penetrates the first baffle in the left and right directions, the right end of the first spring push rod is threadedly connected to the first baffle, the left end of the first spring push rod extends into the groove and is connected to a first spring pressure head through a first spring, the first spring can be extended and retracted in the left and right directions, the first spring pressure head is connected to a first pressure ball, and the first pressure ball abuts against the right side of the valve core;

[0010] The second guide constraint mechanism includes a second electro-mechanical converter and a second constraint, both of which are arranged opposite to each other in the front-to-back direction, the second electro-mechanical converter is located outside the upper valve body and fixed on the front side surface of the upper valve body; the second electro-mechanical converter has a second driving rod horizontally inserted into the groove, and the second driving rod abuts against the front side surface of the valve core to drive the valve core to move in the front-to-back direction; the second constraint includes a second baffle and a second spring push rod, the second baffle is fixed to the rear side surface of the upper valve body, the second spring push rod horizontally penetrates the second baffle in the front-to-back direction, the rear end of the second spring push rod is threadedly connected to the second baffle, the front end of the second spring push rod extends into the groove and is connected to a second spring pressure head through a second spring, the second spring can be extended and retracted in the front-to-back direction, the second spring pressure head is connected to a second pressure ball, and the second pressure ball abuts against the right side surface of the valve core;

[0011] An upper oil inlet groove, an upper oil outlet groove and an upper low-pressure groove are respectively provided on the lower surface of the upper pressure compensation plate;

[0012] A first lower oil inlet groove, a first lower oil outlet groove and a first lower low-pressure groove are respectively provided on the upper surface of the lower pressure compensation plate; a second lower oil inlet groove, a second lower oil outlet groove and a second lower low-pressure groove are respectively provided on the lower surface of the lower pressure compensation plate, wherein the second lower oil inlet groove and the first lower oil inlet groove are symmetrically arranged with respect to the central cross-section of the lower pressure compensation plate, the second lower oil outlet groove and the first lower oil outlet groove are symmetrically arranged with respect to the central cross-section of the lower pressure compensation plate, and the second lower low-pressure groove and the first lower low-pressure groove are symmetrically arranged with respect to the central cross-section of the lower pressure compensation plate Symmetrically arranged; the second lower oil inlet groove is connected to the first lower oil inlet groove through the lower oil inlet hole, the second lower oil outlet groove is connected to the first lower oil outlet groove through the lower oil outlet hole, and the second lower low-pressure groove is connected to the first lower low-pressure groove through the lower low-pressure hole; the valve core is respectively provided with a middle oil inlet groove, a middle oil outlet groove and a middle and low-pressure hole that pass through the upper and lower parts, the right side of the middle oil outlet groove, the left side of the upper oil inlet groove and the left side of the first lower oil inlet groove constitute a valve port, the projection of the right side of the middle oil outlet groove on the valve core is a valve port curve, and the valve port curve is a curve or a broken line;

[0013] The first lower oil inlet trough and the upper oil inlet trough are symmetrically arranged in the vertical direction, the first lower oil outlet trough and the upper oil outlet trough are symmetrically arranged in the vertical direction, and the first lower low-pressure trough and the upper low-pressure trough are symmetrically arranged in the vertical direction; the middle oil outlet trough and the middle oil inlet trough are spaced apart in the left and right directions, and the length of the middle oil outlet trough in the left and right direction is greater than the distance between the first lower oil outlet trough and the first lower oil inlet trough;

[0014] An oil inlet, an oil outlet and an oil return port are provided on the lower surface of the lower valve body, and an oil inlet flow channel, an oil outlet flow channel and a low-pressure flow channel are respectively provided in the lower valve body, the second lower oil inlet groove is connected to the oil inlet through the oil inlet flow channel, the second lower oil outlet groove is connected to the oil outlet through the oil outlet flow channel, and the second lower low-pressure groove is connected to the oil return port through the low-pressure flow channel;

[0015] The second lower oil inlet groove, the lower oil inlet hole, the first lower oil inlet groove, the middle oil inlet groove and the upper oil inlet groove are aligned and connected vertically to form a high-pressure chamber; the second lower oil outlet groove, the lower oil outlet hole, the first lower oil outlet groove, the middle oil outlet groove and the upper oil outlet groove are aligned and connected vertically to form a working chamber; the second lower low-pressure groove, the lower low-pressure through hole, the first lower low-pressure groove, the middle and low-pressure holes and the upper low-pressure groove are aligned and connected vertically to form a low-pressure chamber; the high-pressure chamber is connected with the oil inlet port via the oil inlet flow channel to form an oil inlet channel; the working chamber is connected with the oil outlet port via the oil outlet flow channel to form an oil outlet channel; the low-pressure chamber is connected with the oil return port via the low-pressure flow channel to form an oil return channel;

[0016] The upper pressure compensation plate is provided with a plurality of upper low-pressure holes, the bottom openings of the upper low-pressure holes extend into the upper low-pressure groove and communicate with the upper low-pressure groove, and the top openings of the upper low-pressure holes are located on the upper surface of the upper pressure compensation plate;

[0017] The control valve further includes a pressure compensating device, the pressure compensating device including a first mounting groove and a second mounting groove provided on the lower surface of the upper valve body, wherein the first mounting groove and the upper surface of the upper pressure compensating plate enclose a first regulating chamber, and the second mounting groove and the upper surface of the upper pressure compensating plate enclose a second regulating chamber; a first regulating piston that can only move up and down is provided in the first regulating chamber, and a second regulating piston that can only move up and down is provided in the second regulating chamber, and a first sealing device is provided between the inner wall surface of the first regulating chamber and the outer peripheral surface of the first regulating piston, and a second sealing device is provided between the inner wall surface of the second regulating chamber and the outer peripheral surface of the second regulating piston;

[0018] The upper valve body is also provided with a first pressure regulating hole for inputting high-pressure control oil to the top of the first regulating piston and a second pressure regulating hole for inputting working pressure control oil to the top of the second regulating piston; the bottom end of the first pressure regulating hole is connected to the bottom of the first mounting groove, the top end of the first pressure regulating hole is located on the upper surface of the valve body and is connected to the oil outlet, the bottom end of the second pressure regulating hole is connected to the bottom of the second mounting groove, the top end of the second pressure regulating hole is located on the upper surface of the valve body and is connected to the oil inlet.

[0019] Furthermore, the first lower oil outlet groove and the first lower oil inlet groove are both square grooves, the first lower oil outlet groove and the first lower oil inlet groove are spaced apart and aligned left and right, and the first lower low-pressure groove is a first circular annular groove surrounding the first lower oil inlet groove and the first lower oil outlet groove;

[0020] The second lower oil outlet groove and the second lower oil inlet groove are both square grooves, the second lower oil outlet groove and the second lower oil inlet groove are spaced apart and aligned left and right, and the second lower low-pressure groove is a second circular annular groove surrounding the second lower oil inlet groove and the second lower oil outlet groove;

[0021] The upper oil inlet groove and the upper oil outlet groove are both square grooves, and the upper oil inlet groove and the upper oil outlet groove are spaced apart and aligned left and right. The upper low-pressure groove is a third circular ring groove surrounding the upper oil inlet groove and the upper oil outlet groove.

[0022] Furthermore, the middle oil inlet groove is an elliptical groove or a rectangular groove.

[0023] Furthermore, the valve mouth curve includes a first line segment, a second line segment and a third line segment connected in sequence, and the second line segment is located on the right side of the first line segment and the second line segment; there is a first angle between the first line segment and the second line segment, and there is a second angle between the third line segment and the second line segment, and the first angle and the second angle are the same in size.

[0024] Furthermore, the middle oil outlet groove includes a rectangular groove located on the left and a trapezoidal groove located on the right, and the right side of the rectangular groove is connected to the left side of the trapezoidal groove; the projection of the rectangular groove on the upper end surface of the valve core is a rectangle, and the projection of the trapezoidal groove on the upper end surface of the valve core is a trapezoid, and the right side of the rectangle is collinear with the lower base of the trapezoid.

[0025] Furthermore, the middle oil outlet groove is composed of a plurality of spaced apart strip grooves, the strip grooves are parallel to each other, the strip grooves extend horizontally from left to right, the left ends of the strip grooves are aligned, and the lengths of the strip grooves are different.

[0026] Furthermore, a plurality of upper low-pressure holes are provided on the upper pressure compensation plate at intervals, and the upper low-pressure holes are arranged in a circle around the upper low-pressure groove.

[0027] Furthermore, the projected area of ​​the middle oil outlet groove on the lower end surface of the valve core is larger than the projected area of ​​the first lower oil outlet groove on the lower end surface of the valve core; the projected area of ​​the middle oil inlet groove on the lower end surface of the valve core is smaller than the projected area of ​​the first lower oil inlet groove on the lower end surface of the valve core.

[0028] Furthermore, a plurality of medium and low pressure holes are provided on the valve core at intervals, and the medium and low pressure holes are arranged in a circle along the valve core, and the medium and low pressure holes are connected to the upper low pressure groove above and the first lower low pressure groove below.

[0029] Furthermore, the valve core is plate-shaped, and a vertical plane is provided at equal angular intervals on the front, rear, left and right sides of the valve core; wherein the first driving rod and the second driving rod respectively abut against the vertical planes on the left and front sides; the first pressure ball is in point contact with the vertical plane on the right side of the valve core, and the second pressure ball is in point contact with the vertical plane on the rear side of the valve core.

[0030] The above one or more technical solutions in the embodiments of the present application have at least one or more of the following technical effects:

[0031] 1) The embodiment of the present application forms an oil inlet channel, an oil outlet channel and an oil return channel by setting an upper pressure compensation plate, a valve core and a lower pressure compensation plate stacked up and down, and when the valve core deviates in the horizontal plane, the valve port area gradient connecting the oil inlet channel and the oil outlet channel will change; by setting a first guide constraint mechanism that can drive the valve core to move left and right and a second guide constraint mechanism that drives the valve core to move forward and backward, the valve core is pushed to perform a compound motion in two degrees of freedom directions, continuously changing the opening area gradient of the valve core valve port, thereby changing the flow gain and achieving regulation of the flow gain of the control valve. Since the first guide constraint mechanism and the second guide constraint mechanism of the embodiment of the present application control and adjust the originally fixed flow gain of the control valve based on normal flow or pressure control of a single control valve, not only the flow gain of the control valve is no longer limited by its own mechanical structure, but the control mechanism has a simple structure and a small volume, which overcomes the technical problem in the prior art that the flow gain of the electro-hydraulic control valve is limited by its own mechanical structure or the control structure is bulky, and achieves the beneficial effect of greatly improving the dynamic performance of the electro-hydraulic control system. Moreover, due to the good continuity of the valve port continuous curve flow regulation, there is no obvious transient impact of the fluid during the flow switching process. In addition, the upper and lower clearances of the valve core are reduced under the action of pressure compensation through the pressure compensation plate, thereby reducing leakage and effectively improving the control accuracy of the control valve.

[0032] 2) By respectively arranging an upper pressure compensation plate and a lower pressure compensation plate above and below the floating valve core, and arranging a pressure compensation device on the upper pressure compensation plate, the pressure compensation device is adjusted to make the upper pressure compensation plate move downward and press the valve core, so that the gap between the upper and lower end surfaces of the valve core and the upper and lower pressure compensation plates is reduced, thereby reducing the leakage of the gap, which can effectively improve the flow control accuracy of the control valve.

[0033] 3) The gaps between the upper and lower end surfaces of the valve core and the upper and lower pressure compensation plates are reduced, which can also prevent oil pollutants and particulate matter from entering the working gap, making the valve core less likely to be scratched, worn, or stuck by pollutants.

[0034] 4) The valve port curve can be made into a continuous type or a discrete type. The continuous valve port curve can realize the function of stepless adjustment of flow gain, and the discrete valve port curve can realize the function of step-by-step adjustment of flow gain.

[0035] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A cross-sectional view of an electro-hydraulic control valve capable of adjusting flow gain according to an embodiment of the present invention;

[0037] Figure 2 Schematic diagram of the structure of an electro-hydraulic control valve capable of adjusting flow gain in an embodiment of the present invention;

[0038] Figure 3 for Figure 2 Middle BB section view;

[0039] Figure 4 An exploded view of a portion of the structure of an electro-hydraulic control valve capable of adjusting flow gain according to an embodiment of the present invention;

[0040] Figure 5 Schematic diagram of pressure calculation of an electro-hydraulic control valve with adjustable flow gain in an embodiment of the present invention Figure 1 ;

[0041] Figure 6 Schematic diagram of pressure calculation of an electro-hydraulic control valve with adjustable flow gain in an embodiment of the present invention Figure 2 ;

[0042] Figure 7 This is a flow gain adjustment working principle diagram of an electro-hydraulic control valve with adjustable flow gain in an embodiment of the present invention;

[0043] Figure 8 The figure is a schematic diagram of a discrete structure of a valve core of an electro-hydraulic control valve with adjustable flow gain in an embodiment of the present invention.

[0044] Explanation of the accompanying symbols: first electro-mechanical converter 1, upper valve body 2, lower pressure compensation plate 3, upper pressure compensation plate 4, first regulating piston 5, second regulating piston 6, valve core 7, first pressure ball 8, first spring pressure head 9, first spring 10, first spring push rod 11, first baffle 12, lower valve body 13, second electro-mechanical converter 14, second pressure ball 15, second spring pressure head 16, second spring 17, second spring push rod 18, second baffle 19, first lower oil inlet groove p1, middle oil inlet groove p2, upper oil inlet groove p3, lower oil inlet hole p4, second lower oil inlet groove p5, first lower oil outlet groove a1, middle oil outlet groove a2, upper oil outlet groove a3, lower oil outlet hole a4, second lower oil outlet groove a5, first lower low-pressure groove t1, lower low-pressure hole t2, upper low-pressure groove t3, upper low-pressure hole t4, middle low-pressure hole t5, second lower low-pressure groove t6, oil inlet P, oil outlet A, oil return port T, oil inlet flow channel p, oil outlet flow channel a, low-pressure flow channel t, high-pressure chamber P1, working chamber A1, low-pressure chamber T1, valve port curve L, first line segment L1, second line segment L2, third line segment L3, strip groove e. DETAILED DESCRIPTION

[0045] The embodiments of the present application provide an electro-hydraulic control valve with adjustable flow gain to solve the technical problems in the prior art that the flow gain of the electro-hydraulic control valve is limited by its own mechanical structure or the flow gain control system is bulky and complex to control.

[0046] In order to solve the above technical problems, the overall idea of ​​the technical solution provided by the present application is as follows: by setting up an upper pressure compensation plate, a valve core and a lower pressure compensation plate stacked up and down and buckling them together to form an oil inlet channel, an oil outlet channel and an oil return channel, and when the valve core deviates in the horizontal plane, the valve port area gradient connecting the oil inlet channel and the oil outlet channel will change; by setting up a first guide constraint mechanism that can drive the valve core to move left and right and a second guide constraint mechanism that drives the valve core to move forward and backward, the valve core is pushed to perform a compound motion in two degrees of freedom directions, continuously changing the opening area gradient of the valve core valve port, thereby changing the flow gain and achieving the control of the flow gain of the control valve. Since the first guide constraint mechanism and the second guide constraint mechanism of the embodiment of the present application control and adjust the originally fixed flow gain of the control valve based on normal flow or pressure control of a single control valve, not only the flow gain of the control valve is no longer limited by its own mechanical structure, but the control mechanism has a simple structure and a small size, overcoming the technical problems in the prior art that the flow gain of the electro-hydraulic control valve is limited by its own mechanical structure or the control system is bulky and complex to control, and achieving the beneficial effect of greatly improving the dynamic performance of the electro-hydraulic control system. Moreover, due to the good continuity of the valve port continuous curve flow regulation, there is no obvious transient impact of the fluid during the flow switching process. In addition, the upper and lower clearances of the valve core are reduced under the action of pressure compensation through the pressure compensation plate, thereby reducing leakage and effectively improving the control accuracy of the control valve.

[0047] The technical solution of the present application is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present application and the specific features in the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations on the technical solution of the present application. Unless there is a conflict, the embodiments of the present application and the technical features in the embodiments can be combined with each other.

[0048] Figure 1 2 is a cross-sectional view of an electro-hydraulic control valve capable of adjusting flow gain according to an embodiment of the present invention. Figure 2 FIG1 is a schematic structural diagram of an electro-hydraulic control valve capable of adjusting flow gain in an embodiment of the present invention. Figure 3 for Figure 2 Middle BB section view, Figure 4 FIG. 1 is an exploded view of a portion of the structure of an electro-hydraulic control valve capable of adjusting flow gain according to an embodiment of the present invention. Figure 1 、 2 As shown in Figures 3 and 4, the hydraulic valve includes an upper valve body 2 and a lower valve body 13 fixedly connected to each other, a groove is provided on the lower surface of the upper valve body 2, and an upper pressure compensation plate 4 and a lower pressure compensation plate 3 which can only move up and down are provided in sequence in the groove from top to bottom.

[0049] A valve core 7 is provided between the upper pressure compensation plate 4 and the lower pressure compensation plate 3. A first guide constraint mechanism for driving the valve core 7 to move in the left and right directions and a second guide constraint mechanism for driving the valve core 7 to move in the front and back directions are respectively provided around the valve core 7.

[0050] Specifically, the upper and lower pressure compensating plates 4 and 3 are spaced apart within the grooves, leaving only vertical clearance for the upper and lower pressure compensating plates 4 and 3 to move vertically, thereby limiting their vertical movement. The upper and lower pressure compensating plates 4 and 3, as well as the valve core 7, are all made of a material that is highly hard, wear-resistant, has a low coefficient of friction, and has a high surface finish, such as ceramic.

[0051] It should be noted that this embodiment is based on Figure 1 The upward direction is the direction facing Figure 1 The bottom of the direction is downward, facing Figure 1 The left side is the left direction, facing Figure 1 The right side is the right direction, Figure 1 The side facing the observer is the front, and the side facing away from the observer is the back, and the limitations of the up, down, left, right, front and back directions are only for the convenience of description and are not limitations on the technical solution of the present invention.

[0052] like Figure 3 、 4As shown in Figure 7, the first guide and restraining mechanism includes a first electro-mechanical converter 1 and a first restrainer, both of which are arranged opposite to each other in the left-right direction. The first electro-mechanical converter 1 is located outside the upper valve body 2 and fixed on the left side of the upper valve body 2; the first electro-mechanical converter has a first drive rod extending horizontally to the right and penetrating into the groove, and the first drive rod abuts against the left side of the valve core to drive the valve core 7 to move in the left-right direction; the first restraining device includes a first baffle 12 and a first spring push rod 11, the first baffle 12 is fixed to the right side of the upper valve body 2, the first spring push rod 11 horizontally penetrates the first baffle 12 in the left-right direction, the right end of the first spring push rod 11 is threadedly connected to the first baffle 12, the left end of the first spring push rod 11 extends into the groove and is connected to a first spring pressure head 9 through a first spring 10, the first spring 10 can be extended and retracted in the left-right direction, the first spring pressure head 9 is connected to a first pressure ball 8, and the first pressure ball 8 abuts against the right side of the valve core 7;

[0053] The second guide and restraining mechanism includes a second electro-mechanical converter 14 and a second restrainer, both of which are arranged opposite to each other in the front-to-back direction. The second electro-mechanical converter 14 is located outside the upper valve body 2 and fixed on the front side of the upper valve body 2; the second electro-mechanical converter 14 has a second drive rod horizontally inserted into the groove, and the second drive rod abuts against the front side of the valve core 7 to drive the valve core 7 to move in the front-to-back direction; the second restraining device includes a second baffle 19 and a second spring push rod 18, the second baffle 19 is fixed to the rear side of the upper valve body 2, the second spring push rod 18 horizontally penetrates the second baffle 19 in the front-to-back direction, the rear end of the second spring push rod 18 is threadedly connected to the second baffle 19, the front end of the second spring push rod 18 extends into the groove and is connected to a second spring pressure head 16 through a second spring 17, the second spring 17 can be extended and retracted in the front-to-back direction, the second spring pressure head 16 is connected to a second pressure ball 15, and the second pressure ball 15 abuts against the right side of the valve core 7.

[0054] Specifically, the valve core 7 is plate-shaped, and a vertical plane is respectively provided on the front side, rear side, left side and right side of the valve core 7 (for example, the projection of the valve core 7 on the lower pressure compensation plate 3 is an octagon), and the first driving rod and the second driving rod respectively contact the vertical planes on the left side and the front side; the first pressure ball 8 and the second pressure ball 15 are both steel balls, and the first pressure ball 8 is in point contact with the vertical plane on the right side of the upper valve core 7, and the second pressure ball 15 is in point contact with the vertical plane on the rear side of the valve core 7.

[0055] Specifically, by rotating the first spring push rod 11, the axial relative movement between the first spring push rod 11 and the first baffle 12 due to the threaded connection is converted into the axial displacement of the first spring push rod 11, and the preload force of the first spring 10 can be adjusted; similarly, by rotating the second spring push rod 18, the axial relative movement between the second spring push rod 18 and the second baffle 19 due to the threaded connection is converted into the axial displacement of the second spring push rod 18, and the preload force of the second spring 17 can be adjusted.

[0056] like Figure 4 As shown, an upper oil inlet groove p3, an upper oil outlet groove a3 and an upper low-pressure groove t3 are respectively provided on the lower surface of the upper pressure compensation plate 4.

[0057] As shown in Figures 5, a first lower oil inlet groove p1, a first lower oil outlet groove a1 and a first lower low-pressure groove t1 are respectively provided on the upper surface of the lower pressure compensation plate 3; a second lower oil inlet groove p5, a second lower oil outlet groove a5 and a second lower low-pressure groove t6 are respectively provided on the lower surface of the lower pressure compensation plate 3, wherein the second lower oil inlet groove p5 and the first lower oil inlet groove p1 are symmetrically arranged with respect to the central cross-section of the lower pressure compensation plate 3, the second lower oil outlet groove a5 and the first lower oil outlet groove a1 are symmetrically arranged with respect to the central cross-section of the lower pressure compensation plate 3, and the second lower low-pressure groove t6 and the first lower low-pressure groove t1 are symmetrically arranged with respect to the central cross-section of the lower pressure compensation plate 3; and the second lower oil inlet groove p5 is connected with the first lower oil inlet groove p1 through the lower oil inlet hole p4, the second lower oil outlet groove a5 is connected with the first lower oil outlet groove a1 through the lower oil outlet hole a4, and the second lower low-pressure groove t6 is connected with the first lower low-pressure groove t1 through the lower low-pressure hole t2.

[0058] Specifically, the central cross section refers to the cross section of the downforce compensation plate 3 in the middle along the up-down direction.

[0059] like Figure 4 6, the valve core 7 is respectively provided with a middle oil inlet groove p2, a middle oil outlet groove a2 and a middle and low pressure hole t5 which are connected vertically. The right side of the middle oil outlet groove a2, the left side of the upper oil inlet groove p3 and the left side of the first lower oil inlet groove p1 constitute the valve port. The projection of the right side of the middle oil outlet groove a2 on the valve core 7 is the valve port curve L, and the valve port curve L is a curve or a broken line.

[0060] Specifically, when the right side of the middle oil outlet groove a2, the left side of the upper oil inlet groove p3 and the left side of the first lower oil inlet groove p1 are vertically connected, the valve port is open; when the right side of the middle oil outlet groove a2, the left side of the upper oil inlet groove p3 and the left side of the first lower oil inlet groove p1 are offset, the valve port is closed. At this time, the valve core 7 is in the original position. Figure 1、 4 As shown, the first lower oil inlet groove p1 and the upper oil inlet groove p3 are symmetrically arranged in the upper and lower directions, the first lower oil outlet groove a1 and the upper oil outlet groove a3 are symmetrically arranged in the upper and lower directions, and the first lower low-pressure groove t1 and the upper low-pressure groove t3 are symmetrically arranged in the upper and lower directions; the middle oil outlet groove a2 and the middle oil inlet groove p2 are spaced apart in the left and right directions, and the length of the middle oil outlet groove a2 along the left and right direction is greater than the distance between the first lower oil outlet groove a1 and the first lower oil inlet groove p1 (because the first lower oil outlet groove a1 and the upper oil outlet groove a3 are symmetrically arranged, and the first lower oil inlet groove p1 and the upper oil inlet groove p3 are symmetrically arranged, the length of the middle oil outlet groove a2 along the left and right direction must also be greater than the distance between the upper oil outlet groove a3 and the upper oil inlet groove p3); so that the middle oil outlet groove a2 can simultaneously connect the oil inlet channel and the oil outlet channel when the valve core 7 is in the open state.

[0061] Specifically, the lower oil inlet groove p1 and the upper oil inlet groove p3 are symmetrically arranged about the plane where the valve core 7 is located, the lower oil outlet groove a1 and the upper oil outlet groove a3 are symmetrically arranged about the plane where the valve core 7 is located, and the first lower low-pressure groove t1 and the upper low-pressure groove t3 are symmetrically arranged about the plane where the valve core 7 is located.

[0062] like Figure 1 、 3 As shown, an oil inlet P, an oil outlet A and an oil return port T are provided on the lower surface of the lower valve body 13, and an oil inlet flow channel p, an oil outlet flow channel a and a low-pressure flow channel t are respectively provided in the lower valve body 13. The second lower oil inlet groove p5 is connected with the oil inlet P through the oil inlet flow channel p, the second lower oil outlet groove a5 is connected with the oil outlet A through the oil outlet flow channel a, and the second lower low-pressure groove t6 is connected with the oil return port T through the low-pressure flow channel t.

[0063] The second lower oil inlet groove p5, the lower oil inlet hole p4, the first lower oil inlet groove p1, the middle oil inlet groove p2, the upper oil inlet grooves p3 and p5 are aligned and connected vertically to form a high-pressure chamber P1; the second lower oil outlet groove a5, the lower oil outlet hole a4, the first lower oil outlet groove a1, the middle oil outlet groove a2, the upper oil outlet grooves a3 and a5 are aligned and connected vertically to form a working chamber A1; the second lower low-pressure groove t6, the lower The low-pressure through hole t2, the first lower low-pressure groove t1, the medium-low-pressure hole t5 and the upper low-pressure groove t3 are aligned vertically and connected to form a low-pressure chamber T1; the high-pressure chamber P1 is connected to the oil inlet P through the oil inlet channel p to form an oil inlet channel; the working chamber A1 is connected to the oil outlet A through the oil outlet channel a to form an oil outlet channel; the low-pressure chamber T1 is connected to the oil return port T through the low-pressure channel t to form an oil return channel.

[0064] like Figure 1 、 4 As shown, a plurality of upper low-pressure holes t4 are provided in the upper pressure compensation plate 4, the bottom openings of the upper low-pressure holes t4 extend into the upper low-pressure groove t3 and are connected to the upper low-pressure groove t3, and the top openings of the upper low-pressure holes t4 are located on the upper surface of the upper pressure compensation plate 4.

[0065] like Figure 1 、 5 As shown, the control valve also includes a pressure compensation device, which includes a first mounting groove and a second mounting groove opened on the lower surface of the upper valve body 2, and the first mounting groove and the upper surface of the upper pressure compensation plate 4 enclose a first regulating chamber, and the second mounting groove and the upper surface of the upper pressure compensation plate 4 enclose a second regulating chamber; a first regulating piston 5 that can only move up and down is provided in the first regulating chamber, and a second regulating piston 6 that can only move up and down is provided in the second regulating chamber, and a first sealing device is provided between the inner wall surface of the first regulating chamber and the outer peripheral surface of the first regulating piston 5, and a second sealing device is provided between the inner wall surface of the second regulating chamber and the outer peripheral surface of the second regulating piston 6.

[0066] The upper valve body 2 is also provided with a first pressure regulating hole for inputting high-pressure control oil to the top of the first regulating piston 5 and a second pressure regulating hole for inputting working pressure control oil to the top of the second regulating piston 6; the bottom end of the first pressure regulating hole is connected to the bottom of the first mounting groove, the top end of the first pressure regulating hole is located on the upper surface of the valve body 2 and is connected to the oil outlet A, the bottom end of the second pressure regulating hole is connected to the bottom of the second mounting groove, the top end of the second pressure regulating hole is located on the upper surface of the valve body 2 and is connected to the oil inlet P.

[0067] Specifically, when the first and second electro-mechanical converters 1 and 14 are inactive, the valve core 7 is in its original position, its valve port is closed, and the high-pressure chamber P1 is disconnected from the working chamber A1. Specifically, the oil inlet P is disconnected from the oil outlet A. The valve core 7 is suspended due to the action of an oil film of equal pressure on its upper and lower end surfaces. The lower pressure compensator plate 3 is also subjected to the same oil film pressure on its upper and lower end surfaces, maintaining a balanced suspension state.

[0068] The embodiment of the present application forms an oil inlet channel, an oil outlet channel, and an oil return channel by providing an upper pressure compensation plate 4, a valve core 7, and a lower pressure compensation plate 3 stacked up and engaging with each other. When the valve core 7 deflects in the horizontal plane, the valve port area gradient connecting the oil inlet channel and the oil outlet channel changes. By providing a first guide constraint mechanism that can drive the valve core 7 to move left and right and a second guide constraint mechanism that drives the valve core to move forward and backward, the valve core 7 is pushed to perform a compound motion in two degrees of freedom directions, continuously changing the opening area gradient of the valve port of the valve core 7, thereby changing the flow gain and achieving regulation of the flow gain of the control valve. Since the first guide constraint mechanism and the second guide constraint mechanism of the embodiment of the present application control and adjust the originally fixed flow gain of the control valve based on normal flow or pressure control of a single control valve, not only does the flow gain of the control valve no longer need to be limited by its own mechanical structure, but the control mechanism also has a simple structure and a small size, overcoming the technical problems in the prior art where the flow gain of the electro-hydraulic control valve is limited by its own mechanical structure or the control system is bulky and complex to control, thereby achieving the beneficial effect of greatly improving the dynamic performance of the electro-hydraulic control system.

[0069] In addition, due to the good continuity of the valve port continuous curve flow regulation, there is no obvious transient impact of the fluid during the flow switching process. In addition, the upper and lower clearances of the valve core are reduced under the action of pressure compensation through the pressure compensation plate, thereby reducing leakage and effectively improving the control accuracy of the control valve.

[0070] Secondly, by respectively arranging an upper pressure compensation plate 4 and a lower pressure compensation plate 3 above and below the floating valve core 7, and arranging a pressure compensation device on the upper pressure compensation plate 4, the pressure compensation device is adjusted to make the upper pressure compensation plate 4 move downward and press the valve core 7, so that the gap between the upper and lower end surfaces of the valve core 7 and the lower end surface of the upper pressure compensation plate 4 and the upper end surface of the lower pressure compensation plate 3 is reduced, thereby reducing the leakage through the gap, which can effectively improve the flow control accuracy of the control valve.

[0071] Finally, the gaps between the upper and lower end surfaces of the valve core 7 and the upper pressure compensation plate 4 and the lower pressure compensation plate 3 are reduced, which can also prevent oil pollutants and particulate matter from entering the working gap, making the valve core 7 less likely to be scratched, worn, or stuck by pollutants.

[0072] Specifically, when the control valve described in the present invention is an electro-hydraulic proportional valve, the first electro-mechanical converter 1 and the second electro-mechanical converter 14 are both proportional electro-mechanical converters. When the control valve described in the present invention is an electro-hydraulic servo valve, the first electro-mechanical converter 1 and the second electro-mechanical converter 14 are both servo electro-mechanical converters. The proportional electro-mechanical converter and the servo electro-mechanical converter provide power to drive the valve core 7 to move. A controller may also be provided to control the proportional electro-mechanical converter or the servo electro-mechanical converter to operate as needed.

[0073] Furthermore, the upper pressure compensation plate 4 and the lower pressure compensation plate 3 are clearance-matched with the groove.

[0074] Furthermore, the first lower oil outlet groove a1 and the first lower oil inlet groove p1 are both square grooves, the first lower oil outlet groove a1 and the first lower oil inlet groove p1 are spaced apart and aligned left and right, and the first lower low-pressure groove t1 is a first circular annular groove surrounding the first lower oil inlet groove p1 and the first lower oil outlet groove a1; the second lower oil outlet groove a5 and the second lower oil inlet groove p5 are both square grooves, the second lower oil outlet groove a5 and the second lower oil inlet groove p5 are spaced apart and aligned left and right, and the second lower low-pressure groove t6 is a second circular annular groove surrounding the second lower oil inlet groove p5 and the second lower oil outlet groove a5; the upper oil inlet groove p3 and the upper oil outlet groove a3 are both square grooves, and the upper oil inlet groove p3 and the upper oil outlet groove a3 are spaced apart and aligned left and right, and the upper low-pressure groove t3 is a third circular annular groove surrounding the upper oil inlet groove p3 and the upper oil outlet groove a3.

[0075] Furthermore, the lower pressure compensation plate 3 is provided with a plurality of lower low-pressure holes t2 at intervals, and the lower low-pressure holes t2 are arranged in a circle along the first lower low-pressure groove t1. Furthermore, the upper pressure compensation plate 4 is provided with a plurality of upper low-pressure holes t4 at intervals, and the upper low-pressure holes t4 are arranged in a circle along the upper low-pressure groove t3. Furthermore, the valve core 7 is provided with a plurality of intermediate low-pressure holes t5 at intervals, and the intermediate low-pressure holes t5 are arranged in a circle along the valve core 7, and the intermediate low-pressure holes t5 are connected to both the upper upper low-pressure groove t3 and the lower first lower low-pressure groove t1. Furthermore, the intermediate oil inlet groove p2 is an elliptical groove or a rectangular groove.

[0076] Furthermore, the valve mouth curve L includes a first line segment L1, a second line segment L2 and a third line segment L3 connected in sequence, the second line segment L2 is located on the right side of the first line segment L1 and the second line segment L3, and there is a first fold angle between the first line segment L1 and the second line segment L2, and there is a second fold angle between the third line segment L3 and the second line segment L2, and the first fold angle and the second fold angle are the same size.

[0077] Furthermore, the middle oil outlet groove a2 includes a rectangular groove located on the left and a trapezoidal groove located on the right, and the right side of the rectangular groove is connected to the left side of the trapezoidal groove; the projection of the rectangular groove on the upper end surface of the valve core 7 is a rectangle, and the projection of the trapezoidal groove on the upper end surface of the valve core 7 is a trapezoid, and the right side of the rectangle is collinear with the lower base of the trapezoid.

[0078] Further, such as Figure 8 As shown, the projected area of ​​the middle oil outlet groove a2 on the lower end surface of the valve core 7 is larger than the projected area of ​​the first lower oil outlet groove a1 on the lower end surface of the valve core 7; the projected area of ​​the middle oil inlet groove p2 on the lower end surface of the valve core 7 is smaller than the projected area of ​​the first lower oil inlet groove p1 on the lower end surface of the valve core 7.

[0079] Alternatively, the middle oil outlet groove a2 may be in a discontinuous discrete form, that is, the middle oil outlet groove a2 is composed of a plurality of spaced strip grooves e, the strip grooves e are parallel to each other, the strip grooves e extend horizontally from left to right, the left ends of the strip grooves e are aligned, and the lengths of the strip grooves e are different, such as Figure 8 As shown, the length of the strip groove e located in the middle is the longest, and the lengths of the strip grooves e on the front and rear sides decrease.

[0080] Specifically, the valve port curve L can be made into a continuous type or a discrete type. The continuous valve port curve L can realize the function of stepless adjustment of flow gain, and the discrete valve port curve L can realize the function of step-by-step adjustment of flow gain.

[0081] Furthermore, the first sealing device and the second sealing device are both sealing rings.

[0082] Specifically, the sealing rings on the first regulating piston 5 and the second regulating piston 6 are used to isolate the oil on the upper and lower end surfaces of the first regulating piston 5 or the second regulating piston 6 .

[0083] Furthermore, both the upper and lower pressure compensating plates 4 and 3 are cylindrical and circumferentially positioned using pins, work surfaces, and other positioning mechanisms, ensuring that they can only float vertically and cannot rotate. Under the action of the first and second electro-mechanical converters 1 and 14, the valve core 7 can only slide left and right and forward and backward, but cannot rotate. This ensures that the upper and lower edges of the right side of the middle oil outlet groove a2 of the valve core 7, which constitutes the valve port, coincide with the left sides of the upper and lower oil inlet grooves p3 and p1, respectively, in the initial state, resulting in a closed valve port.

[0084] The working principle of the hydraulic valve described in this embodiment is as follows:

[0085] The high-pressure oil in the high-pressure chamber P1 flows into the low-pressure chamber T1 through the gaps between the valve core 7 and the upper pressure compensation plate 4, and between the valve core 7 and the lower pressure compensation plate 3, forming the same pressure oil film on the upper and lower end surfaces of the valve core 7; similarly, the oil in the working chamber A1 flows into the low-pressure chamber T1 through the gaps between the valve core 7 and the upper pressure compensation plate 4, and between the valve core 7 and the lower pressure compensation plate 3, forming the same pressure oil film on the upper and lower end surfaces of the valve core 7.

[0086] The upper and lower end surfaces of the lower pressure compensation plate 3 have completely consistent structural features, so the upper and lower end surfaces are subjected to equal pressure, and the lower pressure compensation plate 3 is in a pressure balance state, thereby making the lower pressure compensation plate 3 suspended.

[0087] The pressure oil film makes the clearance pressures between the upper and lower end surfaces of the valve core 7 equal, thereby making the valve core 7 suspended.

[0088] A pressure oil film is formed between the lower end face of the upper pressure compensation plate 4 and the upper end face of the valve core 7. For the upper end face of the upper pressure compensation plate 4, on the one hand, the oil in the low-pressure chamber T1 covers the upper end face of the upper pressure compensation plate 4 through the upper low-pressure hole t4 on the upper pressure compensation plate 4 and forms a low-pressure oil film; on the other hand, the high-pressure control oil introduced by the second pressure regulating hole acts on the second regulating piston 6, and the working pressure control oil introduced by the first pressure regulating hole acts on the first regulating piston 5. The first regulating piston 5 and the second regulating piston 6 both act on the upper end face of the upper pressure compensation plate 4 to form pressure compensation. The lower end face of the upper pressure compensation plate 4 is subjected to the vertical upward force of the pressure oil film, and the upper end face of the upper pressure compensation plate 4 is subjected to the resultant force F of the vertical downward pressure of the first regulating piston 5 and the second regulating piston 6 and the pressure of the return oil port T acting on the lower end face. The direction of the resultant force F is vertically downward. Here, the expression of the resultant force F acting on the upper and lower end faces of the upper pressure compensation plate 4 is ensured as follows:

[0089] F=M·S4+N·S3-P2·S2-A2·S1>0

[0090] In the above formula, M is the oil inlet pressure, N is the oil outlet pressure, P2 is the equivalent pressure of the pressure oil film distribution of the end surface clearance between the high-pressure chamber P1 and the low-pressure chamber T1 valve core 7, A2 is the equivalent pressure of the pressure oil film distribution of the end surface clearance between the working chamber A1 and the low-pressure chamber T1 valve core 7; S4 is the end surface area of ​​the second regulating piston 6, S3 is the end surface area of ​​the first regulating piston 5, S2 is the equivalent area of ​​the pressure oil film of the end surface clearance between the high-pressure chamber P1 and the low-pressure chamber T1 valve core 7, S1 is the equivalent area of ​​the pressure oil film of the end surface clearance between the working chamber A1 and the low-pressure chamber T1 valve core 7, as shown in FIG. Figure 5 、 6 shown.

[0091] When F>0, the pressure on the upper end surface of the upper pressure compensation plate 4 is greater than the pressure on the lower end surface, and the upper pressure compensation plate 4 moves vertically downward, pressing the valve core 7 and the lower pressure compensation plate 3, and its pressing force is F.

[0092] Assuming that the pressures at the oil inlet P and the oil outlet A remain unchanged, the required resultant force F, i.e., the clamping force of the upper pressure compensation plate 4 on the valve core 7, can be obtained by controlling the pressure variables P2, A2 and the area variables S4, S3, S2, and S1. This allows for adjustment of the gaps between the upper end face of the valve core 7 and the lower end face of the upper pressure compensation plate 4, and between the lower end face of the valve core 7 and the upper end face of the lower pressure compensation plate 3. Reducing the gaps can reduce the impact of leakage on the control flow, thereby improving the flow control accuracy of the control valve.

[0093] When the first electro-mechanical converter is actuated, the valve core 7 is pushed to move to the right. At the same time, when the second electro-mechanical converter 14 is actuated, the valve core 7 is pushed to move back and forth. The valve core 7 undergoes a combined reciprocating motion in the two degrees of freedom directions within the center plane of the valve core. The reciprocating motion law of the valve core 7 is a composite setting curve of the first electro-mechanical converter 1 and the first electro-mechanical converter 14 controller; the valve port curve L of the valve core is set according to the working condition characteristics. Under the designed motion laws of the first electro-mechanical converter 1 and the second electro-mechanical converter 14, the valve port of the valve core 7 is opened, and the high-pressure chamber P1 is communicated with the working chamber A1, that is, the oil inlet channel is communicated with the oil outlet channel. The valve core 7, the upper pressure compensation plate 4 and the lower pressure compensation plate 3 are compressed under the action of the resultant force F exerted on the upper pressure compensation plate 4. At this time, the gaps between the upper end surface of the valve core 7 and the lower end surface of the upper pressure compensation plate 4, and between the lower end surface of the valve core 7 and the upper end surface of the lower pressure compensation plate 3 are reduced, thereby reducing leakage and improving the flow control accuracy of the control valve. The valve core 7, the upper pressure compensation plate 4, and the lower pressure compensation plate 3 are all made of ceramics and other materials with high hardness, wear resistance, low friction coefficient, and high surface finish. The end face friction coefficient is small, and the friction and shear force that the valve core 7 needs to overcome to open and slide are small, and the required thrust of the first electro-mechanical converter 1 and the second electro-mechanical converter 14 is small.

[0094] When both first and second electro-mechanical converters 1, 14 return to their original positions, valve core 7 slides back to its original position under the combined action of first and second springs 10, 17, and the valve port closes according to the pre-designed motion pattern of valve core 7. High-pressure chamber P1 and working chamber A1 are no longer in communication, and the oil inlet and outlet channels are no longer in communication, completing one operating cycle.

[0095] The equivalent concentrated force exerted by the first electro-mechanical converter 1 of the present invention on the left plane of the valve core 7 is equal to the force exerted by the first steel ball 8 of the first left constraint on the right plane of the valve core, and the acting torques are equal in magnitude and opposite in direction; similarly, the equivalent concentrated force exerted by the second electro-mechanical converter on the front plane of the valve core is equal to the force exerted by the second steel ball 15 of the second rear constraint on the rear plane of the valve core, and the acting torques are equal in magnitude and opposite in direction; the first driving rod of the first constraint and the second driving rod of the second constraint respectively have guiding and constraining functions on the planes in contact with the valve core 7. During the movement of the valve core 7, the force and torque are balanced, and the valve core 7 will not rotate. It can only slide in two degrees of freedom left and right and front and back in the center plane of the valve core 7.

[0096] In the present invention, a pressure compensation device is provided on the floating valve core 7. The pressure compensation device adjusts the size and direction of the resultant force acting on the upper pressure compensation plate 4, thereby prompting the upper pressure compensation plate 4 to move vertically downward and press the valve core 7 and the lower pressure compensation plate 3, so that the gap between the valve core 7 and the upper pressure compensation plate 4, and the gap between the valve core 7 and the lower pressure compensation plate 3 are reduced, thereby reducing the influence of leakage on the control flow and improving the flow control accuracy of the valve.

[0097] The valve port curve L of the flat valve core 7 of the present invention can be designed into various continuous curves such as function curves, composite curves, special-shaped curves, and empirical curves according to the working conditions. At the same time, the first electro-mechanical converter 1 and the second electro-mechanical converter 2 can promote the valve core 7 to perform composite motion in the left and right and front and back directions of the central plane of the valve core 7 according to the control strategy and different motion laws designed for different working conditions, continuously change the valve core valve port opening area gradient, realize stepless adjustment of the electro-hydraulic proportional / servo valve flow gain, and improve the control performance of the electro-hydraulic proportional / servo valve.

[0098] The valve port curve L of the plate valve core 7 of the present invention can also be made into a discrete type, such as Figure 8 As shown. The discrete valve port curve L is still Figure 6 、 7 The valve core valve port curve L shown is consistent, and the discrete valve ports are communicated with each other to prevent the pressure oil from crushing the partitions between the valve ports. The reasonable layout of the spacing between the discrete valve ports can realize the function of step-by-step adjustment of the flow gain.

[0099] The above one or more technical solutions in the embodiments of the present application have at least one or more of the following technical effects:

[0100] 1) In the embodiment of the present application, an upper pressure compensation plate 4, a valve core 7 and a lower pressure compensation plate 3 are stacked up and fastened together to form an oil inlet channel, an oil outlet channel and an oil return channel. When the valve core 7 is offset on the horizontal plane, the valve port area gradient connecting the oil inlet channel and the oil outlet channel will change. By providing a first guide constraint mechanism that can drive the valve core 7 to move left and right and a second guide constraint mechanism that drives the valve core to move forward and backward, the valve core 7 is pushed to perform a compound motion in two degrees of freedom directions, and the opening area gradient of the valve port of the valve core 7 is continuously changed, thereby changing the flow gain and realizing the regulation of the flow gain of the control valve. Since the first guide constraint mechanism and the second guide constraint mechanism of the embodiment of the present application control and adjust the originally fixed flow gain of the control valve based on normal flow or pressure control of a single control valve, not only the flow gain of the control valve is no longer limited by its own mechanical structure, but the control mechanism has a simple structure and a small size, which overcomes the technical problems in the prior art that the flow gain of the electro-hydraulic control valve is limited by its own mechanical structure or the control system is bulky and complex to control, and achieves the beneficial effect of greatly improving the dynamic performance of the electro-hydraulic control system. Moreover, since the continuity of the continuous curve flow regulation of the valve port is good, there is no obvious transient impact of the fluid during the switching process. In addition, the upper and lower clearances of the valve core are reduced under the action of pressure compensation through the pressure compensation plate, which can effectively improve the control accuracy of the control valve.

[0101] 2) By respectively arranging an upper pressure compensation plate 4 and a lower pressure compensation plate 3 above and below the floating valve core 7, and arranging a pressure compensation device on the upper pressure compensation plate 4, the pressure compensation device is adjusted to make the upper pressure compensation plate 4 move downward and press the valve core 7, so that the gap between the valve core 7 and the upper pressure compensation plate 4 and the lower pressure compensation plate 3 is reduced, thereby reducing the leakage through the gap, which can effectively improve the flow control accuracy of the control valve.

[0102] 3) The gaps between the upper and lower end surfaces of the valve core 7 and the upper pressure compensation plate 4 and the lower pressure compensation plate 3 are reduced, which can also prevent oil pollutants and particulate matter from entering the working gap, making the valve core 7 less likely to be scratched, worn, or stuck by pollutants.

[0103] 4) The valve port curve L can be made into a continuous type or a discrete type. The continuous valve port curve L can realize the function of stepless adjustment of flow gain, and the discrete valve port curve L can realize the function of step-by-step adjustment of flow gain.

[0104] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. An electro-hydraulic control valve with adjustable flow gain, characterized in that: The electro-hydraulic control valve comprises an upper valve body (2) and a lower valve body (13) fixedly connected to each other in an upper and lower manner. A groove is provided on the lower surface of the upper valve body (2). An upper pressure compensation plate (4) and a lower pressure compensation plate (3) are provided in the groove in sequence from top to bottom. Both of the upper and lower pressure compensation plates can only move up and down. A valve core (7) is provided between the upper pressure compensation plate (4) and the lower pressure compensation plate (3), and a first guide constraint mechanism for driving the valve core (7) to move in the left-right direction and a second guide constraint mechanism for driving the valve core (7) to move in the front-back direction are respectively provided around the valve core (7); The first guide constraint mechanism includes a first electro-mechanical converter (1) and a first constraint which are both arranged relative to each other in the left and right directions, wherein the first electro-mechanical converter (1) is located outside the upper valve body (2) and is fixed on the left side of the upper valve body (2); the first electro-mechanical converter (1) has a first drive rod which extends horizontally to the right and penetrates into the groove, and the first drive rod abuts against the left side of the valve core (7) to drive the valve core (7) to move in the left and right directions; the first constraint includes a first baffle (12) and a first spring push rod (11), wherein the first baffle (12) is fixed on the right side of the upper valve body (2), the first spring push rod (11) horizontally penetrates the first baffle (12) in the left-right direction, the right end of the first spring push rod (11) is threadedly connected to the first baffle (12), the left end of the first spring push rod (11) extends into the groove and is connected to the first spring pressure head (9) through the first spring (10), the first spring (10) can be extended and retracted in the left-right direction, the first spring pressure head (9) is connected to the first pressure ball (8), and the first pressure ball (8) abuts against the right side of the valve core (7); The second guide constraint mechanism includes a second electro-mechanical converter (14) and a second constraint which are arranged relative to each other in the front-back direction, wherein the second electro-mechanical converter (14) is located outside the upper valve body (2) and is fixed on the front side of the upper valve body (2); the second electro-mechanical converter (14) has a second drive rod which is horizontally inserted into the groove, and the second drive rod abuts against the front side of the valve core (7) to drive the valve core (7) to move in the front-back direction; the second constraint includes a second baffle (19) and a second spring push rod (18), wherein the second baffle (19) ) is fixed on the rear side of the upper valve body (2), the second spring push rod (18) horizontally penetrates the second baffle (19) in the front-to-back direction, the rear end of the second spring push rod (18) is threadedly connected to the second baffle (19), the front end of the second spring push rod (18) extends into the groove and is connected to the second spring pressure head (16) through the second spring (17), the second spring (17) can be extended and retracted in the front-to-back direction, the second spring pressure head (16) is connected to the second pressure ball (15), and the second pressure ball (15) abuts against the right side of the valve core (7); An upper oil inlet groove (p3), an upper oil outlet groove (a3) ​​and an upper low-pressure groove (t3) are respectively provided on the lower surface of the upper pressure compensation plate (4); A first lower oil inlet groove (p1), a first lower oil outlet groove (a1) and a first lower low-pressure groove (t1) are respectively provided on the upper surface of the lower pressure compensation plate (3); a second lower oil inlet groove (p5), a second lower oil outlet groove (a5) and a second lower low-pressure groove (t6) are respectively provided on the lower surface of the lower pressure compensation plate (3), wherein the second lower oil inlet groove (p5) and the first lower oil inlet groove (p1) are symmetrically arranged with respect to the central cross-section of the lower pressure compensation plate (3), the second lower oil outlet groove (a5) and the first lower oil outlet groove (a1) are symmetrically arranged with respect to the central cross-section of the lower pressure compensation plate (3), and the second lower low-pressure groove (t6) and the first lower low-pressure groove (t1) are symmetrically arranged with respect to the central cross-section of the lower pressure compensation plate (3); and The second lower oil inlet groove (p5) is connected to the first lower oil inlet groove (p1) through the lower oil inlet hole (p4), the second lower oil outlet groove (a5) is connected to the first lower oil outlet groove (a1) through the lower oil outlet hole (a4), and the second lower low-pressure groove (t6) is connected to the first lower low-pressure groove (t1) through the lower low-pressure hole (t2); the valve core (7) is respectively provided with a middle oil inlet groove (p2), a middle oil outlet groove (a2) and a middle and low-pressure hole (t5) which are connected vertically; the right side of the middle oil outlet groove (a2), the left side of the upper oil inlet groove (p3) and the left side of the first lower oil inlet groove (p1) constitute a valve port; the projection of the right side of the middle oil outlet groove (a2) on the valve core (7) is a valve port curve (L), and the valve port curve (L) is a curve or a broken line; The first lower oil inlet groove (p1) and the upper oil inlet groove (p3) are symmetrically arranged in the vertical direction, the first lower oil outlet groove (a1) and the upper oil outlet groove (a3) ​​are symmetrically arranged in the vertical direction, and the first lower low-pressure groove (t1) and the upper low-pressure groove (t3) are symmetrically arranged in the vertical direction; the middle oil outlet groove (a2) and the middle oil inlet groove (p2) are spaced apart in the left and right directions, and the length of the middle oil outlet groove (a2) in the left and right direction is greater than the distance between the first lower oil outlet groove (a1) and the first lower oil inlet groove (p1); An oil inlet (P), an oil outlet (A) and an oil return port (T) are provided on the lower surface of the lower valve body (13); an oil inlet flow channel (p), an oil outlet flow channel (a) and a low-pressure flow channel (t) are respectively provided in the lower valve body (13); the second lower oil inlet groove (p5) is communicated with the oil inlet (P) via the oil inlet flow channel (p); the second lower oil outlet groove (a5) is communicated with the oil outlet (A) via the oil outlet flow channel (a); and the second lower low-pressure groove (t6) is communicated with the oil return port (T) via the low-pressure flow channel (t); The second lower oil inlet groove (p5), the lower oil inlet hole (p4), the first lower oil inlet groove (p1), the middle oil inlet groove (p2) and the upper oil inlet groove (p3) are aligned vertically and connected to form a high-pressure chamber (P1); the second lower oil outlet groove (a5), the lower oil outlet hole (a4), the first lower oil outlet groove (a1), the middle oil outlet groove (a2) and the upper oil outlet groove (a3) ​​are aligned vertically and connected to form a working chamber (A1); the second lower low-pressure groove (t6), the lower low-pressure hole ( t2), the first lower low-pressure groove (t1), the medium-low-pressure hole (t5) and the upper low-pressure groove (t3) are aligned vertically and connected to form a low-pressure chamber (T1); the high-pressure chamber (P1) is connected to the oil inlet (P) through the oil inlet flow channel (p) to form an oil inlet channel; the working chamber (A1) is connected to the oil outlet (A) through the oil outlet flow channel (a) to form an oil outlet channel; the low-pressure chamber (T1) is connected to the oil return port (T) through the low-pressure flow channel (t) to form an oil return channel; The upper pressure compensation plate (4) is provided with a plurality of upper low-pressure holes (t4), the bottom openings of the upper low-pressure holes (t4) extend into the upper low-pressure groove (t3) and communicate with the upper low-pressure groove (t3), and the top openings of the upper low-pressure holes (t4) are located on the upper surface of the upper pressure compensation plate (4); The control valve further comprises a pressure compensating device, the pressure compensating device comprising a first mounting groove and a second mounting groove provided on the lower surface of the upper valve body (2), wherein the first mounting groove and the upper surface of the upper pressure compensating plate (4) enclose a first regulating chamber, and the second mounting groove and the upper surface of the upper pressure compensating plate (4) enclose a second regulating chamber; a first regulating piston (5) which can only move up and down is provided in the first regulating chamber, and a second regulating piston (6) which can only move up and down is provided in the second regulating chamber, and a first sealing device is provided between the inner wall surface of the first regulating chamber and the outer peripheral surface of the first regulating piston (5), and a second sealing device is provided between the inner wall surface of the second regulating chamber and the outer peripheral surface of the second regulating piston (6); The upper valve body (2) is further provided with a first pressure regulating hole for inputting high-pressure control oil to the upper part of the first regulating piston (5) and a second pressure regulating hole for inputting working pressure control oil to the upper part of the second regulating piston (6); the bottom end of the first pressure regulating hole is communicated with the bottom of the first mounting groove, the top end of the first pressure regulating hole is located on the upper surface of the valve body (2) and is communicated with the oil outlet (A), the bottom end of the second pressure regulating hole is communicated with the bottom of the second mounting groove, the top end of the second pressure regulating hole is located on the upper surface of the valve body (2) and is communicated with the oil inlet (P); A plurality of upper low-pressure holes (t4) are provided at intervals on the upper pressure compensation plate (4), and the upper low-pressure holes (t4) are arranged in a circle around the upper low-pressure groove (t3); A plurality of medium and low pressure holes (t5) are provided on the valve core (7) at intervals, and the medium and low pressure holes (t5) are arranged in a circle along the valve core (7), and the medium and low pressure holes (t5) are connected to the upper low pressure groove (t3) above and the first lower low pressure groove (t1) below.

2. The electro-hydraulic control valve with adjustable flow gain according to claim 1, characterized in that: The first lower oil outlet groove (a1) and the first lower oil inlet groove (p1) are both square grooves. The first lower oil outlet groove (a1) and the first lower oil inlet groove (p1) are spaced apart and aligned left and right. The first lower low-pressure groove (t1) is a first circular annular groove surrounding the first lower oil inlet groove (p1) and the first lower oil outlet groove (a1). The second lower oil outlet groove (a5) and the second lower oil inlet groove (p5) are both square grooves. The second lower oil outlet groove (a5) and the second lower oil inlet groove (p5) are spaced apart and aligned left and right. The second lower low-pressure groove (t6) is a second circular annular groove surrounding the second lower oil inlet groove (p5) and the second lower oil outlet groove (a5). The upper oil inlet groove (p3) and the upper oil outlet groove (a3) ​​are both square grooves, and the upper oil inlet groove (p3) and the upper oil outlet groove (a3) ​​are spaced apart and aligned left and right. The upper low-pressure groove (t3) is a third circular ring groove surrounding the upper oil inlet groove (p3) and the upper oil outlet groove (a3).

3. The electro-hydraulic control valve with adjustable flow gain according to claim 1, characterized in that: The middle oil inlet groove (p2) is an elliptical groove or a rectangular groove.

4. The electro-hydraulic control valve with adjustable flow gain according to claim 1, characterized in that: The valve mouth curve (L) includes a first line segment (L1), a second line segment (L2) and a third line segment (L3) connected in sequence, and the second line segment (L2) is located on the right side of the first line segment (L1) and the third line segment (L3); there is a first fold angle between the first line segment (L1) and the second line segment (L2), and there is a second fold angle between the third line segment (L3) and the second line segment (L2), and the first fold angle and the second fold angle are the same in size.

5. The electro-hydraulic control valve with adjustable flow gain according to claim 4, characterized in that: The middle oil outlet groove (a2) includes a rectangular groove located on the left side and a trapezoidal groove located on the right side, and the right side of the rectangular groove is connected to the left side of the trapezoidal groove; the projection of the rectangular groove on the upper end surface of the valve core (7) is a rectangle, and the projection of the trapezoidal groove on the upper end surface of the valve core (7) is a trapezoid, and the right side of the rectangle is collinear with the lower base of the trapezoid.

6. The electro-hydraulic control valve with adjustable flow gain according to claim 4, characterized in that: The middle oil outlet groove (a2) is composed of a plurality of spaced apart strip grooves (e), the strip grooves (e) are parallel to each other, the strip grooves (e) extend horizontally from left to right, the left ends of the strip grooves (e) are aligned, and the lengths of the strip grooves (e) are different.

7. The electro-hydraulic control valve with adjustable flow gain according to claim 1, characterized in that: The projected area of ​​the middle oil outlet groove (a2) on the lower end surface of the valve core (7) is larger than the projected area of ​​the first lower oil outlet groove (a1) on the lower end surface of the valve core (7); the projected area of ​​the middle oil inlet groove (p2) on the lower end surface of the valve core (7) is smaller than the projected area of ​​the first lower oil inlet groove (p1) on the lower end surface of the valve core (7).

8. The electro-hydraulic control valve with adjustable flow gain according to claim 1, characterized in that: The valve core (7) is plate-shaped, and a vertical plane is provided at equal angular intervals on the front side, rear side, left side and right side of the valve core (7); wherein the first driving rod and the second driving rod respectively contact the vertical planes on the left side and the front side; the first pressure ball (8) is in point contact with the vertical plane on the right side of the valve core (7), and the second pressure ball (15) is in point contact with the vertical plane on the rear side of the valve core (7).

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