High-flow gain direction control valve with position feedback function and method

Abstract

The invention belongs to the field of hydraulic pressure, and discloses a high-flow gain direction control valve with a position feedback function and a using method, a main valve element can be arranged in a valve body in an axial left-right moving mode, when the main valve element is located at a left limit position, a first load port is communicated with an oil supply port, and a second load port is communicated with an oil return port, and when the main valve element is located at a right limit position, a second load port is communicated with an oil return port. The load port 1 is communicated with the oil return port, and the load port 2 is communicated with the oil supply port; the main valve element is also used as a valve sleeve of the pilot valve element, and the pilot valve element can be arranged in the main valve element in a left-right moving mode in the axial direction. When the pilot valve element is located at the left limit position, the oil supply port communicates with the right end of the main valve element so as to push the main valve element to the left limit position, and when the pilot valve element is located at the right limit position, the oil supply port communicates with the left end of the main valve element so as to push the main valve element to the right limit position. The pilot valve element is embedded in the main valve element, and large-flow output can be achieved by driving the large-diameter main valve element to move through movement of the small-diameter pilot valve element.

Description

Technical Field

[0001] This invention belongs to the field of hydraulics and relates to a directional control valve structure, and more particularly to a directional control valve structure and control method that is compact, has position feedback function and can achieve high flow gain. Background Technology

[0002] As a core control component of a hydraulic system, the performance of directional control valves directly affects the accuracy and efficiency of downstream actuators. The requirements for directional control valves in hydraulic fields such as construction machinery and aerospace are becoming increasingly stringent, demanding both high flow gain to drive high-speed actuator movement and feedback functionality to improve the reliability of the hydraulic system.

[0003] Existing technologies generally use small pilot valves to drive the movement of large-diameter main valve cores to open the valve port and achieve large flow rates. The pilot valve and main valve are usually separate or externally mounted. This layout makes the pilot valve and main valve independent components, which need to be connected by bolts or other means. This not only requires installation space but also connecting components, increasing the installation volume and weight. This is very unfriendly to hydraulic systems with compact layouts and strict weight requirements, and it also limits its application.

[0004] During operation, the actual displacement of the valve core of a directional control valve is affected by various factors such as friction, oil viscosity, and oil contamination. Most existing high-flow directional control valves do not have the function of real-time detection and feedback of valve core position, which greatly reduces the control accuracy of the hydraulic system. Summary of the Invention

[0005] To address the aforementioned issues, this invention provides a high-flow-rate gain directional control valve and method with position feedback function. This valve has a compact structure, ensuring both high-flow-rate output and position feedback functionality, thus meeting the requirements of hydraulic systems.

[0006] The technical solution of the present invention is as follows: A high-flow-gain directional control valve with position feedback function includes a valve body, a main valve core, a pilot valve core, a left end cover, and a right end cover. The valve body is provided with a load port 1, a load port 2, a return port, and a supply port. The main valve core is axially movable within the valve body. When the main valve core is in the left limit position, load port 1 and the supply port are connected, and load port 2 and the return port are connected. When the main valve core is in the right limit position, load port 1 and the return port are connected, and load port 2 and the supply port are connected. It also serves as the valve sleeve for the pilot valve core, which is axially movable within the main valve core. When the pilot valve core is in the left limit position, the oil supply port connects to the right end of the main valve core, thereby pushing the main valve core to the left limit position. When the pilot valve core is in the right limit position, the oil supply port connects to the left end of the main valve core, thereby pushing the main valve core to the right limit position. The left and right ends of the valve body are respectively provided with a left end cover and a right end cover, and a return spring is provided between the left and right ends of the pilot valve core and the left and right end covers.

[0007] Furthermore, a position feedback module is provided, which is connected to the left or right end of the pilot valve core and detects the position of the pilot valve core.

[0008] Furthermore, the position feedback module includes a valve core position sensor, a sensor core, and a connecting rod. The left or right end of the pilot valve core is axially connected to one end of the connecting rod, and the other end of the connecting rod is equipped with the sensor core, which is located inside the valve core position sensor.

[0009] Furthermore, the axial length of the main valve core is less than the axial length of the through hole in the valve body. The main valve core is provided with 6 shoulders along the axial direction, namely the first shoulder to the sixth shoulder. The first shoulder and the sixth shoulder are located at the left and right ends of the main valve core, and an oil passage hole is provided radially between the third shoulder and the fourth shoulder.

[0010] Furthermore, the axial length of the pilot valve core is greater than the axial length of the main valve core but less than the axial length of the valve body through hole. The two ends of the pilot valve core are valve stems. The middle position of the pilot valve core is provided with 5 shoulders along the axial direction, namely shoulders A to E. The outer diameter of shoulders B, C and D are matched with the inner diameter of the main valve core. Shoulders B and D are provided with small oil passage holes in the axial direction. The cylindrical surfaces of shoulders B, C and D are provided with pressure equalization grooves.

[0011] Furthermore, under the action of the return spring, the pilot valve core is in the middle zero position of the main valve core, and at the same time, the main valve core is also in the middle zero position of the valve body. At this time, the oil inlet of the valve body is located between the third and fourth shoulders of the main valve core. The load port 1 and load port 2 of the valve body are respectively located between the second and third shoulders of the main valve core and between the fourth and fifth shoulders. The C shoulder of the pilot valve core blocks the oil passage between the third and fourth shoulders of the main valve core.

[0012] Furthermore, the valve body has two return ports. When the main valve core is in the middle zero position, the two return ports of the valve body are respectively located between the first and second shoulders of the main valve core and between the fifth and sixth shoulders of the main valve core.

[0013] A high-flow-gain directional control method with position feedback function, using a aforementioned high-flow-gain directional control valve with position feedback function, includes the following method: Connect the two ends of the piston-type load structure to the load port 1 and load port 2 of the valve body respectively. Drive the pilot valve core axially by external force. When the pilot valve core moves to the left or right limit position, the oil supply port of the valve body is connected to the right or left limit position of the main valve core. The high-pressure oil in the oil supply port builds pressure between the main valve core and the valve body, pushing the main valve core to move to the left or right limit position in the valve body, thereby connecting the oil supply port to the load port 1 or load port 2. At the same time, the load port 2 or load port 1 is connected to the return port, thus completing the driving of the piston-type load structure.

[0014] The beneficial effects of this invention are as follows: 1. This invention embeds the pilot valve core inside the main valve core. By moving the small-diameter pilot valve core, the movement of the large-diameter main valve core can be driven to achieve a large flow output. This is very suitable for hydraulic systems with limited installation space and strict weight requirements. 2. The return springs at both ends of the valve core can achieve fail-alignment and stop controlling the load when there is a problem with the valve structure, thus improving the safety of the system operation.

[0015] 3. Integrating the valve core position sensor into the valve body enables real-time detection of the pilot valve core displacement, providing position feedback functionality to improve the control accuracy of the hydraulic system. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a structural diagram of a high-flow-rate gain directional control valve with position feedback function according to the present invention. Figure 2 This is a structural diagram of the main valve core in this invention. Figure 3 This is a structural diagram of the pilot valve core in this invention. Figure 4 This is a diagram showing the position of the threaded hole of the valve core position sensor in this invention. Figure 5 This is a diagram showing the location of the threaded hole in the end cap of the present invention. 1 is the valve core position sensor, 2 is the sensor core, 3 is the connecting rod, 4 is the left end cover, 5 is the sealing ring, 6 is the valve body, 7 is the reset spring, 8 is the spring seat, 9 is the pilot valve core, 10 is the main valve core, and 11 is the right end cover. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] The features and illustrative embodiments of various aspects of the present invention will now be described in detail. Numerous specific details are set forth in the following detailed description to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention. The invention is by no means limited to any specific setups and methods set forth below, but covers any improvements, substitutions, and modifications to structures, methods, and devices without departing from the spirit of the invention. Well-known structures and techniques are not shown in the drawings and the following description to avoid unnecessarily obscuring the invention.

[0020] In the description of this invention, it should be noted that the directions or positional relationships indicated by terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing and simplifying the invention, and should not be construed as limiting the invention. Furthermore, the use of ordinal numbers (e.g., "first and second," etc.) is for distinguishing objects and is not limited to this order, and should not be construed as indicating or implying relative importance.

[0021] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly, encompassing both direct connection and indirect connection via an intermediate medium. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0022] It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other, and the various embodiments can be referenced and cited in each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] Example 1: A high-flow-gain directional control valve with position feedback function includes a valve body 6, a main valve core 10, a pilot valve core 9, a left end cover 4, and a right end cover 11. The valve body 6 is provided with a load port 1, a load port 2, a return port, and a supply port. The main valve core 10 is axially movable within the valve body 6. When the main valve core 10 is in the left limit position, the load port 1 and the supply port are connected, and the load port 2 and the return port are connected. When the main valve core 10 is in the right limit position, the load port 1 and the return port are connected, and the load port 2 and the supply port are connected. The main valve core 10 also... As the valve sleeve of the pilot valve core 9, the pilot valve core 9 is axially movable in the main valve core 10. When the pilot valve core 9 is in the left limit position, the oil supply port is connected to the right end of the main valve core 10, thereby pushing the main valve core 10 to the left limit position. When the pilot valve core 9 is in the right limit position, the oil supply port is connected to the left end of the main valve core 10, thereby pushing the main valve core 10 to the right limit position. The left and right ends of the valve body 6 are respectively provided with a left end cover 4 and a right end cover 11. A return spring 7 is provided between the left and right ends of the pilot valve core 9 and the left end cover 4 and the right end cover 11.

[0024] It also includes a position feedback module, which is connected to the left or right end of the pilot valve core 9 and detects the position of the pilot valve core 9.

[0025] The position feedback module includes a valve core position sensor 1, a sensor core 2, and a connecting rod 3. The left or right end of the pilot valve core 9 is axially connected to one end of the connecting rod 3, and the other end of the connecting rod 3 is equipped with the sensor core 2. The sensor core 2 is located inside the valve core position sensor 1.

[0026] The axial length of the main valve core 10 is less than the axial length of the through hole in the valve body 6. The main valve core 10 is provided with 6 shoulders along the axial direction, namely the first shoulder to the sixth shoulder. The first shoulder and the sixth shoulder are located at the left and right ends of the main valve core 10, and an oil passage hole is provided radially between the third shoulder and the fourth shoulder.

[0027] The axial length of the pilot valve core 9 is greater than the axial length of the main valve core 10 and less than the axial length of the through hole of the valve body 6. The two ends of the pilot valve core 9 are valve stems. The middle position of the pilot valve core 9 is provided with 5 shoulders along the axial direction, namely shoulders A to E. The outer diameter of shoulders B, C and D are matched with the inner diameter of the main valve core 10. Shoulders B and D are provided with small oil passage holes in the axial direction. The cylindrical surfaces of shoulders B, C and D are provided with pressure equalization grooves.

[0028] Under the action of the return spring 7, the pilot valve core 9 is in the middle zero position of the main valve core 10, and the main valve core 10 is also in the middle zero position of the valve body 6. At this time, the oil inlet of the valve body 6 is located between the third and fourth shoulders of the main valve core 10. The load port 1 and load port 2 of the valve body 6 are respectively located between the second and third shoulders and between the fourth and fifth shoulders of the main valve core 10. The C shoulder of the pilot valve core 9 blocks the oil passage between the third and fourth shoulders of the main valve core 10.

[0029] The valve body 6 has two oil return ports. When the main valve core 10 is in the middle zero position, the two oil return ports of the valve body 6 are respectively located between the first and second shoulders of the main valve core 10 and between the fifth and sixth shoulders of the main valve core 10.

[0030] A high-flow-gain directional control method with position feedback function, using a aforementioned high-flow-gain directional control valve with position feedback function, includes the following method: Connect the two ends of the piston-type load structure to the load port 1 and load port 2 of the valve body respectively. Drive the pilot valve core axially by external force. When the pilot valve core moves to the left or right limit position, the oil supply port of the valve body is connected to the right or left limit position of the main valve core. The high-pressure oil in the oil supply port builds pressure between the main valve core and the valve body, pushing the main valve core to move to the left or right limit position in the valve body, thereby connecting the oil supply port to the load port 1 or load port 2. At the same time, the load port 2 or load port 1 is connected to the return port, thus completing the driving of the piston-type load structure.

[0031] Example 2: The system includes a valve core position sensor 1, a sensor core 2, a connecting rod 3, a left end cover 4, a sealing ring 5, a valve body 6, a return spring 7, a spring seat 8, a pilot valve core 9, a main valve core 10, and a right end cover 11. The main valve core is located in the middle of the valve body 6, and spring seats and return springs are located at both ends of the valve body. The valve body 6 has left and right end covers 4 and 11 on its outer end faces. The valve core position sensor 1 is installed on the outside of the left end cover 4. The main valve core 10 is clearance-fitted with the valve body 6. The pilot valve core 9 is embedded inside the main valve core 10 and is also clearance-fitted with the main valve core 10. The left valve stem end face of the pilot valve core 9 has a through hole for interference fit with the connecting rod. The connecting rod 3 is threadedly connected to the sensor core 2.

[0032] The valve body 6 has a through hole on its end face. The through hole is in clearance fit with the outer surface of the main valve core 10. The valve body 6 has an oil inlet, an oil return port, and load ports 1 and 2, all of which are connected to the through hole on the end face of the valve body.

[0033] The axial length of the main valve core 10 is less than the axial length of the through hole of the valve body 6. It has 6 shoulders, which are defined as the first to the sixth shoulders, to block the oil passage. The third and fourth shoulders have 4 oil passage square holes in the radial direction, which are evenly distributed at 90° intervals in the circumferential direction. The end face of the main valve core 10 has a through hole, and the diameter of the through hole is in clearance fit with the outer diameter of the pilot valve core 9. The axial length of the pilot valve core 9 is greater than the axial length of the main valve core 10 and less than the axial length of the through hole of the valve body 6. Its two ends are valve stems, and there are 5 shoulders in the middle part, which are defined as shoulders A to E respectively. The nominal outer diameter of shoulders B, C and D is the same as the nominal diameter of the through hole on the end face of the main valve core 10. The end face of shoulders B and D is provided with 4 small oil passage holes, which are evenly distributed at 90° intervals on the end face to connect the two cavities on both sides of the shoulders. The cylindrical surface of shoulders B, C and D is provided with pressure equalization grooves. The outer diameter of shoulders A and E is smaller than the outer diameter of shoulders B, C and D, but larger than the valve stem diameter. The valve stem end face on the left end is provided with a blind hole, which is in an interference fit relationship with the connecting rod 3. The spring seat 8 is a hollow L-shaped stepped shaft structure. The cylindrical surface is divided into two sections. The outer diameter of the larger diameter section is larger than the diameter of the pilot valve cores 9A and E shoulders and the outer diameter of the return spring 7. The outer diameter of the smaller diameter section is smaller than the inner diameter of the return spring 7. The end face of the spring seat 8 is provided with a through hole. The diameter of the through hole is smaller than the diameter of the pilot valve cores 9A and E but larger than the valve stem diameter of the pilot valve core 9. This allows the pilot valve cores 9A and E to abut against the end face of the spring seat while the valve stem of the pilot valve core 9 can pass through the through hole of the spring seat 8. The left and right end caps 4 and 11 are mirror images of each other, and both have bosses on their inner sides. The bosses are transitionally fitted with the through holes on the end face of the valve body 6. The cylindrical surface of the bosses has a sealing ring groove for installing the sealing ring to seal the oil. The end face of the bosses has two coaxial through holes. The through hole near the return spring 7 is used for guiding the spring, and the through hole near the sensor 1 is used to communicate with the inside of the sensor 1. The diameter of the through hole near the return spring 7 is larger, and the diameter of the through hole near the sensor 1 is larger than the diameter of the drive device connecting mechanism and the connecting rod 3. The end caps 4 and 11 have 4 threaded holes around their perimeter for easy connection to the valve body with screws. The valve body 6 has a spring seat 8 and a return spring 7 at each of its left and right ends. The spring seats 8 and return springs 7 at both ends are identical and mate with the bosses of the left and right end caps 4 and 11, respectively. Four threaded holes are also provided around the right end face of valve core position sensor 1 for easy connection by screws; The oil inlet P port of valve body 6 is located in the middle part corresponding to the third and fourth shoulders of the main valve core 10 and is directly opposite the square hole in the middle of the cylindrical surface of the main valve core 10. The axial length of the square hole in the middle of the cylindrical surface of the main valve core 10 is the same as the axial length of the third shoulder of the pilot valve core 9. That is, when the pilot valve core is in the middle position, the two are in a zero-opening relationship. The load port 1 of the valve body 6 is positioned directly opposite the middle of the second and third shoulders of the main valve core 10, and the axial length of the load port 1 is equal to the distance between the outer end faces of these two shoulders. That is, the second and third shoulders and the load port 1 are in a zero-opening relationship. Similarly, the load port 2 of the valve body 6 and the fourth and fifth shoulders of the main valve core 10 are also in this zero-opening relationship. According to claim 1, the flow amplification valve structure with position feedback function is characterized in that there are 2 return oil ports R of the valve body, which are respectively set between the first and second shoulders and between the fifth and sixth shoulders of the main valve core 10, and are in an uncovered state with the fifth and sixth shoulders of the main valve core 10. The diameter of the distribution circle containing the center of the oil passage hole on the end face of the pilot valve core 9B and D shoulders is greater than the diameter of its valve stem but less than the diameter of its B and D shoulders.

[0034] When the pilot valve core is in the neutral position, the maximum designed stroke of the main valve core 10 is less than the distance between the end face of the main valve core 10 and the end face of the spring seat 8.

[0035] When no driving force is applied to the pilot valve core 9, the pilot valve core is in the middle position between the valve body 6 and the main valve core 10 under the spring force balance of the return springs on both sides of the valve body. At this time, the shoulder of the pilot valve core 9C closes the oil passage window in the circumferential direction of the main valve core. At this time, the main valve core 10 is also in the middle position, the no-load window is open, and there is no flow output.

[0036] When a leftward driving force (greater than the spring force) is applied to the pilot valve core 9, the pilot valve core 9 moves to the left, opening the circumferential oil passage window of the main valve core 10. The oil enters the cavity formed by the C and D shoulders of the pilot valve core 9 and the inner hole of the main valve core 10, and enters the spring cavity on the right end face of the main valve core 10 through the small oil passage hole set on the end face of the D shoulder of the pilot valve core 9. The hydraulic pressure acts on the right end face of the main valve core 10. At this time, there is no oil pressure on the left end face of the main valve core 10. Driven by the pressure difference on both sides, the main valve core 10 will move to the left and open the load port 1 and load port 2 of the valve body 6. The oil flows out from the load port 1 of the valve body and then flows into the return oil port R through the load port 2. Similarly, when the pilot valve core 9 is driven to the right, the main valve core 10 will move to the right and open the load port 1 and load port 2 of the valve body 6 under the influence of the pressure difference on both sides. The oil flows out from the load port 2 of the valve body and then flows into the return port through the load port 1. Since the diameter of the pilot valve core 9 is smaller than that of the main valve core, under the same pressure difference and valve core stroke, the larger the valve core diameter, the greater the flow rate that the valve can allow to pass. In this way, the flow gain is amplified by driving the main valve core 10 to move through the movement of the pilot valve core 9.

[0037] Example 3: This invention provides a high-flow-gain directional control valve structure with position feedback function, such as... Figure 1As shown, the valve body includes a valve core position sensor 1, a sensor core 2, a connecting rod 3, a left end cover 4, a sealing ring 5, a valve body 6, a return spring 7, a spring seat 8, a pilot valve core 9, a main valve core 10, and a right end cover 11. The pilot valve core 9 is housed within a through hole on the end face of the main valve core 10, with a clearance fit. The main valve core 10 is also housed within a through hole on the end face of the valve body 6, with a similar clearance fit.

[0038] like Figure 2 The main valve core 10 shown has first, second, third, fourth, fifth and sixth shoulders arranged sequentially from left to right along the axial direction on the cylindrical surface. The first three shoulders (first, second and third) are completely symmetrical with the last three shoulders (fourth, none and sixth). There are four oil passage square holes on the valve stem cylindrical surface of the third and fourth shoulders, which are evenly distributed at 90°. The center of the oil passage square holes is equidistant from the third and fourth shoulders, that is, it is located at the axial center of the main valve core 10.

[0039] like Figure 1 The valve body 6 shown is provided with an oil supply port P, and the load port 1, load port 2, and return port R are all connected to the through hole on the end face of the valve body 6. When the main valve core 10 is installed in the middle of the through hole of the valve body 6, the oil supply port P of the valve body 6 is located at the center between the third and fourth shoulders of the main valve core 10, directly opposite the oil passage square hole on the cylindrical surface of the main valve core 10.

[0040] The load ports 1 and 2 of the valve body 6 are symmetrical about the left and right centers of the valve body 6. The load port 1 corresponds to the center between the second and third shoulders of the main valve core 10. Its two working sides in the axial direction are aligned with the left working side of the second shoulder and the right working side of the third shoulder of the main valve core 10, respectively, and are in a zero-open and uncovered state. Similarly, the two working sides in the axial direction of the load port 2 of the valve body 6 are aligned with the left working side of the fourth shoulder and the right working side of the fifth shoulder of the main valve core 10, respectively, and are in a zero-open and uncovered state.

[0041] There are two return oil R points connecting the valve body 6 to its end face through hole, and the two are symmetrical with respect to the left and right centers of the valve body. They are respectively positioned between the first and second shoulders of the main valve core 10 and between the fifth and sixth shoulders of the main valve core 10. like Figure 3As shown, the pilot valve core 9 has five shoulders along the axial direction, defined as shoulders A to E. Shoulder C is located at the center of the pilot valve core 9 along the axial direction. The width of this shoulder is the same as the axial length of the oil passage square hole of the main valve core 10. That is, the left and right working edges of this shoulder are aligned with the left and right working edges of the oil passage square hole of the main valve core 10, respectively, forming a zero-opening state. Shoulders A and B are symmetrically distributed with respect to the axial center of the pilot valve core 9. Shoulders B, C, and D all have pressure equalization grooves on their outer circular surfaces. Shoulders B and D each have four small oil passage holes on their end faces, evenly distributed at 90° along the circumference, which are responsible for connecting the two cavities separated by the shoulders. The diameter of the distribution circle where the center of the four small oil passage holes is located is larger than the diameter of the valve stem of the pilot valve core 9 but smaller than the outer diameter of shoulders B, C, and D. The outer diameters of shoulders B, C, and D are the same, while the outer diameters of shoulders A and E are smaller than the outer diameters of shoulders B, C, and D. The pilot valve core 9 has a blind hole on the far left end of the valve stem, which is in an interference fit with the connecting rod 3. The connecting rod is threaded to the sensor core 2.

[0042] like Figure 1 As shown, the spring seat 8 is an L-shaped rotating body with its cylindrical surface divided into two sections. The outer diameter of the side closer to the main valve core 10 is larger than the outer diameter of the shoulders A and E of the pilot valve core 9, which is used to hold the valve core. Its end face has a through hole with a diameter larger than the valve stem diameter of the pilot valve core 9, which is used for the valve stem to pass through.

[0043] like Figure 1 As shown, both the left 4 and right end caps 11 have bosses near the valve core. The bosses and end caps are an integral structure. The cylindrical surface of the boss has a sealing groove, which is used to install a sealing ring to achieve a sealing effect. The center of the boss is coaxial with the through hole of the valve body 6. A hole is opened on the end face of the boss. This hole is coaxial with the center of the boss and is used to guide the return spring 7. A through hole is opened at the rear end of this hole, which communicates with the outside of the end cap. The two holes are coaxial, and the diameter of the rear hole is smaller than that of the front hole. At the same time, the diameter of the rear hole is larger than that of the connecting rod 2 and the iron core 3, so that the connecting rod 2 and the iron core 3 can pass through.

[0044] like Figure 1 As shown, the outer diameter of the return spring 7 is smaller than the diameter of the large diameter section of the spring seat 8, and its inner diameter is smaller than the diameter of the large diameter section of the spring seat 8. Its two ends abut against the annular surface of the spring seat and the annular surface of the end cap boss hole, respectively.

[0045] The left 4, right end cap 11 and sensor 1 are all provided with threaded holes, which are connected to the valve body 6 by screws.

[0046] When the pilot valve core 9 is in the neutral position, the distance between the end face of the spring seat 8 near the pilot valve core 9 and the end face of the main valve core 10 is greater than the maximum design stroke of the main valve core.

[0047] When no driving force is applied to the pilot valve core 9, the pilot valve core 9 is in the middle position between the valve body and the main valve core under the spring force balance of the return springs on both sides of the valve body. At this time, the left and right working sides of the C shoulder of the pilot valve core 9 just close the oil passage window in the circumferential direction of the main valve core. At this time, the main valve core 10 is also in the middle position, the no-load window is open, and there is no flow output.

[0048] When a leftward driving force (greater than the spring force) is applied to the pilot valve core 9, the pilot valve core 9 moves to the left, opening the circumferential oil passage window of the main valve core 10. The oil enters the cavity formed by the C shoulder and D shoulder of the pilot valve core 9 and the inner hole of the main valve core 10, and enters the spring cavity on the right end face of the main valve core 10 through the small oil passage hole set on the end face of the D shoulder of the pilot valve core 9. The hydraulic pressure acts on the right end face of the main valve core. At this time, there is no oil pressure on the left end face of the main valve core 10. Driven by the pressure difference on both sides, the main valve core 10 will move to the left and open the load port 1 and load port 2 of the valve body 6. The oil flows out from the load port 1 of the valve body 6 and then flows into the return oil port R through the load port 2. Similarly, when the pilot valve core 10 is driven to the right, the main valve core 10 will move to the right and open the load port 1 and load port 2 of the valve body 6 under the pressure difference on both sides. The oil flows out from the load port 2 of the valve body 6 and then flows into the return port through the load port 1. Since the diameter of the pilot valve core 9 is smaller than the diameter of the main valve core 10, under the same pressure difference and valve core stroke, the larger the valve core diameter, the greater the flow rate that the valve can allow to pass. In this way, the flow gain is amplified by driving the main valve core to move through the movement of the pilot valve core.

[0049] Since the sensor core 2 is connected to the pilot valve core 9 through the connecting rod 3, the movement of the pilot valve core will cause the sensor core to move together. The movement of the core 2 causes the change of the magnetic field of the sensor coil, which is eventually converted into a voltage signal output. This enables real-time monitoring of the position of the pilot valve core 9 and realizes the feedback function.

[0050] Embedding the pilot valve core 9 inside the main valve core 6 not only reduces the installation and operation space but also reduces the risk of external oil leakage, which is of great significance for improving the safety of hydraulic systems.

[0051] The above detailed embodiments are a description of the present invention. It should not be considered that the specific embodiments of the present invention are limited to these descriptions. For those skilled in the art, several simple deductions and substitutions can be made without departing from the concept of the present invention, and all of these should be considered to fall within the protection scope of the present invention.

Claims

1. A high-flow-rate gain directional control valve with position feedback function, characterized in that, The valve body (6) includes a main valve core (10), a pilot valve core (9), a left end cap (4), and a right end cap (11). The valve body (6) is provided with a load port 1, a load port 2, a return port, and a supply port. The main valve core (10) is axially movable within the valve body (6). When the main valve core (10) is in the left limit position, the load port 1 and the supply port are connected, and the load port 2 and the return port are connected. When the main valve core (10) is in the right limit position, the load port 1 and the return port are connected, and the load port 2 and the supply port are connected. The main valve core (10) also serves as the valve sleeve for the pilot valve core (9). The core (9) is axially movable in the main valve core (10); when the pilot valve core (9) is in the left limit position, the oil supply port is connected to the right end of the main valve core (10) to push the main valve core (10) to the left limit position; when the pilot valve core (9) is in the right limit position, the oil supply port is connected to the left end of the main valve core (10) to push the main valve core (10) to the right limit position; the left and right ends of the valve body (6) are respectively provided with a left end cover (4) and a right end cover (11), and a return spring (7) is provided between the left and right ends of the pilot valve core (9) and the left end cover (4) and the right end cover (11).

2. The high-flow-rate gain directional control valve with position feedback function according to claim 1, characterized in that, It is also equipped with a position feedback module, which is connected to the left or right end of the pilot valve core (9) and detects the position of the pilot valve core (9).

3. A high-flow-rate gain directional control valve with position feedback function according to claim 2, characterized in that, The position feedback module includes a valve core position sensor (1), a sensor core (2) and a connecting rod (3). The left or right end of the pilot valve core (9) is axially connected to one end of the connecting rod (3), and the other end of the connecting rod (3) is equipped with the sensor core (2). The sensor core (2) is located inside the valve core position sensor (1).

4. A high-flow-rate gain directional control valve with position feedback function according to claim 1, characterized in that, The axial length of the main valve core (10) is less than the axial length of the through hole in the valve body (6). The main valve core (10) has 6 shoulders along the axial direction, namely the first shoulder to the sixth shoulder. The first shoulder and the sixth shoulder are located at the left and right ends of the main valve core (10), and an oil passage hole is provided radially between the third shoulder and the fourth shoulder.

5. A high-flow-rate gain directional control valve with position feedback function according to claim 4, characterized in that, The axial length of the pilot valve core (9) is greater than the axial length of the main valve core (10) and less than the axial length of the through hole of the valve body (6). The two ends of the pilot valve core (9) are valve stems. The pilot valve core (9) has 5 shoulders along the axial direction in the middle position, namely shoulders A to E. The outer diameter of shoulders B, C and D are matched with the inner diameter of the main valve core (10). Shoulders B and D are provided with small oil passage holes in the axial direction. The cylindrical surfaces of shoulders B, C and D are provided with pressure equalization grooves.

6. A high-flow-rate gain directional control valve with position feedback function according to claim 5, characterized in that, Under the action of the return spring (7), the pilot valve core (9) is in the middle zero position of the main valve core (10), and the main valve core (10) is also in the middle zero position of the valve body (6). At this time, the oil inlet of the valve body (6) is between the third shoulder and the fourth shoulder of the main valve core (10). The load port 1 and load port 2 of the valve body (6) are respectively located between the second shoulder and the third shoulder of the main valve core (10) and between the fourth shoulder and the fifth shoulder. The C shoulder of the pilot valve core (9) blocks the oil passage between the third shoulder and the fourth shoulder of the main valve core (10).

7. A high-flow-rate gain directional control valve with position feedback function according to claim 6, characterized in that, The valve body (6) has two oil return ports. When the main valve core (10) is in the middle zero position, the two oil return ports of the valve body (6) are respectively located between the first and second shoulders of the main valve core (10) and between the fifth and sixth shoulders of the main valve core (10).

8. A high-flow-rate gain directional control method with position feedback function, using a high-flow-rate gain directional control valve with position feedback function as described in any one of claims 1-7, characterized in that, Including the following methods: Connect the two ends of the piston-type load structure to the load port 1 and load port 2 of the valve body respectively. Drive the pilot valve core axially by external force. When the pilot valve core moves to the left or right limit position, the oil supply port of the valve body is connected to the right or left limit position of the main valve core. The high-pressure oil in the oil supply port builds pressure between the main valve core and the valve body, pushing the main valve core to move to the left or right limit position in the valve body, thereby connecting the oil supply port to the load port 1 or load port 2. At the same time, the load port 2 or load port 1 is connected to the return port, thus completing the driving of the piston-type load structure.

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