Balancing valve with overcompensation self-adjusting valve

Abstract

This invention discloses a balance valve with an overcompensation adaptive regulating valve, comprising: a main valve body, a pilot valve body, and a control end cover arranged coaxially from front to back; a main valve sleeve and a pilot valve sleeve coaxially and tightly arranged in the internal cavities of the main valve body and the pilot valve body, respectively; a main valve core and a pilot valve core slidably arranged coaxially in the cavities within the main valve sleeve and the pilot valve sleeve, respectively; two ends of a feedback spring abutting against the large-diameter ends of the main valve core and the pilot valve core, respectively; the small-diameter end of the pilot valve core passes through the pilot valve sleeve and is coaxially and abutting against the shaft of the control piston; the pilot spring is arranged between the control piston and the pilot valve body; an overcompensation regulating valve is installed on the main valve body, its inlet communicating with the feedback spring cavity, and its outlet communicating with the front cavity of the pilot valve port; the outlet flow area adaptively adjusts according to the load. This invention can automatically reduce the outlet flow area as the load increases, automatically adjusting the overcompensation effect.

Description

Technical Field

[0001] This invention relates to the field of hydraulic control, and more particularly to a balance valve with an overcompensation adaptive regulating valve. Background Technology

[0002] Balance valves are widely used in hydraulic systems where there are overload conditions, and play a role in regulating the overload lowering speed, providing back pressure, and maintaining the load.

[0003] Taking a truck crane as an example, lifting, telescoping, and luffing operations may all involve conditions exceeding the load limit. Especially during luffing, the load changes with the luffing angle, placing high demands on the controllability of the balance valve. Traditional balance valves are highly susceptible to load changes, exhibiting vibration or stalling when the load suddenly increases, affecting the overall safety performance of the crane. Therefore, the balance valve needs to have the characteristic that the flow rate decreases as the load increases after the load pressure exceeds a certain value; this is the overcompensation characteristic of the balance valve. The load pressure corresponding to the point where the flow rate begins to decrease is the pressure inflection point of the overcompensation characteristic. Existing balance valves with overcompensation functions mostly use damping orifices with a fixed throttling area. After setting the damping value, the overcompensation throttling area remains unchanged during load changes, and the pressure inflection point cannot be altered, failing to meet the overcompensation performance requirements of cranes of different tonnages. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention proposes a balance valve with an overcompensation adaptive regulating valve.

[0005] The specific technical solution is as follows:

[0006] A balanced valve with an overcompensated adaptive regulating valve includes: a main valve body, a pilot valve body, and a control end cover arranged coaxially from front to back; a main valve sleeve and a pilot valve sleeve are coaxially and tightly arranged in the internal cavities of the main valve body and the pilot valve body, a main valve core is coaxially and slidably arranged in the cavity inside the main valve sleeve, and a pilot valve core is coaxially and slidably arranged in the cavity inside the pilot valve sleeve; one end of a feedback spring abuts against the large-diameter end of the main valve core, and the other end abuts against the large-diameter end of the pilot valve core;

[0007] The main valve body has a load port B to supply load oil to the load chamber, and a main valve return port A. The control piston is coaxially slidably arranged in the rear cavity of the pilot valve body. The small-diameter end of the pilot valve core passes through the pilot valve sleeve and is coaxially mounted with the shaft of the control piston. One end of the pilot spring abuts against the control piston, and the other end abuts against the pilot valve body. The pilot valve body has a pilot drain port L that communicates with the pilot spring cavity. The control end cover has an X port to supply pilot control pressure oil to the pilot spring cavity.

[0008] The main valve body is equipped with a compensation regulating valve, whose oil inlet is connected to the feedback spring cavity and whose oil outlet is connected to the front cavity of the pilot valve port. The flow area of ​​the oil outlet is adaptively adjusted according to the load size. The rear cavity of the pilot valve port is connected to port A.

[0009] Furthermore, the overcompensation regulating valve includes: a cartridge valve sleeve, a cartridge valve core, a preload spring, a spring baffle, an overcompensation end cap, a lock nut, and an adjusting stud;

[0010] The cartridge valve sleeve is installed in the main valve body. It is hollow inside, with an oil inlet at the bottom and first flow holes symmetrically opened on the lower outer circumference.

[0011] The cartridge valve core is installed in the cavity inside the cartridge valve sleeve. The cavity is hollow inside. Two orthogonal second flow holes are opened in the bottom body. The vertical second flow hole is coaxial with and connected to the oil inlet. The overlapping part of the horizontal second flow hole and the first flow hole serves as the oil outlet of the overcompensation regulating valve.

[0012] In the initial state, the second transverse flow hole is fully connected to the first flow hole, and the flow area of ​​the oil outlet is the largest.

[0013] The preload spring is installed in the internal cavity of the cartridge valve core, and the spring baffle is installed inside the cartridge valve core and can move axially. The lower end of the preload spring abuts against the bottom of the internal cavity of the cartridge valve core, and the upper end abuts against the lower end face of the spring baffle.

[0014] The overcompensation end cap is fixedly installed at the upper opening of the cartridge valve sleeve, with a coaxial through hole in its center. The adjusting stud is threaded into the through hole to be screwed in or out. The bottom of the adjusting stud is in contact with the upper end face of the spring baffle. The preload of the preload spring is changed by rotating the adjusting stud. The locking nut is sleeved on the outer circumference of the adjusting stud to lock the adjusting stud.

[0015] Furthermore, the cross-section of the first flow hole has a circular upper half and a rectangular lower half, with the intersection width of the upper and lower parts being the width of the rectangle.

[0016] Furthermore, a first annular groove is provided on the outer wall of the valve sleeve corresponding to the feedback spring cavity, and two symmetrically distributed radial through holes are provided on the first annular groove to communicate with the spring feedback cavity; a first radial hole is provided on the inner wall of the main valve body at a position corresponding to the first annular groove, so that the spring feedback cavity is connected to the oil inlet of the overcompensation regulating valve.

[0017] Furthermore, a first stepped blind hole is opened at the rear end of the main valve body, and the main valve sleeve is arranged in the first stepped blind hole; a first stepped through hole coaxial with the first stepped blind hole is opened axially inside the pilot valve body, and the first stepped through hole includes a first cylindrical hole, a second cylindrical hole, a third cylindrical hole, and a fourth cylindrical hole from front to back; the diameter of the first cylindrical hole is the same as the diameter of the rear end of the first stepped blind hole, and the diameter of the second cylindrical hole is adapted to the outer diameter of the small diameter end of the pilot valve core; the front end of the pilot valve sleeve is arranged in the main valve body and abuts against the rear end of the main valve sleeve, and the rear end of the pilot valve sleeve is arranged in the first cylindrical hole, which cooperates to realize the axial and radial limiting of the main valve sleeve and the pilot valve sleeve;

[0018] The control piston and feedback spring are arranged in the third cylindrical hole and the fourth cylindrical hole, with one end of the feedback spring abutting against the disc of the control spring and the other end abutting against the front end face of the third cylindrical hole.

[0019] Furthermore, an annular partition is coaxially fixed to the third cylindrical hole near the second cylindrical hole, and a through hole with the same diameter as the inner diameter of the second cylindrical hole is opened at the center of the annular partition.

[0020] In the initial state, the control piston is in the closed state, and there is a gap between the shaft of the control piston and the small-diameter end of the pilot valve core.

[0021] Furthermore, an annular groove is formed on the inner wall of the main valve body at a position corresponding to the middle of the main valve sleeve, forming a load cavity between the main valve body and the main valve sleeve; several radial through holes are formed in the middle of the main valve sleeve along the circumference to connect the load cavity with the internal cavity of the main valve sleeve.

[0022] The cavity between the small-diameter end of the main valve core and the main valve body is the back pressure cavity. The main valve return port A on the main valve body is connected to the back pressure cavity. The load cavity and the back pressure cavity are connected through the main valve port. A throttling groove on the main valve core connects the load cavity and the feedback spring cavity.

[0023] Furthermore, a pilot valve port is formed between the small-diameter end of the pilot valve core and the pilot valve sleeve, and the front cavity of the pilot valve port is a transition cavity; a second annular groove is provided on the outer wall of the rear end of the pilot valve sleeve, and several symmetrically distributed second radial holes are provided on the second annular groove to communicate with the transition cavity; a channel is provided inside the main valve body and the pilot valve body to connect the second annular groove and the oil outlet of the overcompensation regulating valve;

[0024] The rear cavity of the pilot valve port is a back pressure feedback cavity; a cylindrical hole is radially opened inside the pilot valve body along the radial contact surface between the pilot valve body and the pilot valve sleeve, and the axis of the cylindrical hole is perpendicular to the axis of the pilot valve body, so that a cavity is formed between the pilot valve body and the pilot valve sleeve, which is the back pressure feedback cavity; a channel is opened inside the main valve body and the pilot valve body to connect the back pressure feedback cavity and the main valve return port A.

[0025] Furthermore, a third annular groove is formed on the outer wall of the middle part of the pilot valve sleeve as a quick-closing chamber. Two symmetrically distributed third radial holes are formed on the third annular groove to communicate with the cavity inside the pilot valve sleeve. A channel is formed inside the main valve body to connect the load chamber and the quick-closing chamber. When the pilot valve core is in the initial position, the pilot valve port is closed, and the feedback spring chamber is connected to the load chamber through the quick-closing chamber. When the pilot valve port is open, the quick-closing chamber and the feedback spring chamber are not connected.

[0026] Furthermore, a pilot control chamber is formed between the control end cover and the control piston, and a flow channel is formed inside the control piston to connect the pilot control chamber with the pilot spring chamber; an X-port is formed on the control end cover to connect the external pilot control pressure source with the pilot control chamber, and a pressure measuring port E is formed to measure the pressure of the pilot control oil.

[0027] The beneficial effects of this invention are:

[0028] (1) In the case of overload, the overcompensation adaptive regulating valve can automatically reduce the flow area of ​​the oil outlet as the load increases, thereby automatically increasing the overcompensation effect.

[0029] (2) The present invention integrates a cartridge valve with adaptive adjustment function into the main valve body, which makes the balance valve have fewer parts, a simple and compact structure, and high reliability. Attached Figure Description

[0030] Figure 1 This is a front view of the balance valve with a compensation adaptive regulating valve in an embodiment of the present invention.

[0031] Figure 2 This is a top view of the balance valve with a compensated adaptive regulating valve in an embodiment of the present invention.

[0032] Figure 3 This is a cross-sectional view of the balance valve with overcompensated adaptive regulating valve in an embodiment of the present invention.

[0033] Figure 4 This is a structural diagram of the overcompensated adaptive regulating valve in an embodiment of the present invention.

[0034] Figure 5 This is a schematic diagram of the oil flow direction when the load-releasing balance valve opens in reverse in an embodiment of the present invention.

[0035] Figure 6 This is a cross-sectional view (HH) of the balance valve with overcompensated adaptive regulating valve in an embodiment of the present invention.

[0036] In the diagram, the components are: main valve body 1, main valve core 2, main valve sleeve 3, feedback spring 4, overcompensation regulating valve 5, cartridge valve sleeve 5-1, cartridge valve core 5-2, preload spring 5-3, spring baffle 5-4, overcompensation end cap 5-5, locking nut 5-6, adjusting stud 5-7; pilot valve core 6, pilot valve sleeve 7, pilot valve body 8, pilot spring 9, control piston 10, and control end cap 11. Detailed Implementation

[0037] The present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments. The objectives and effects of the present invention will become clearer as a result. The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0038] like Figures 1-3 As shown, a balance valve with an overcompensation adaptive regulating valve includes: a main valve body 1, a main valve core 2, a main valve sleeve 3, a feedback spring 4, an overcompensation regulating valve 5, a pilot valve core 6, a pilot valve sleeve 7, a pilot valve body 8, a pilot spring 9, a control piston 10, and a control end cover 11.

[0039] The main valve body 1, pilot valve body 8, and control end cap 11 are arranged coaxially from front to back. The main valve body 1 and pilot valve body 8 are coaxially fixed together by bolts to form the main valve body. The internal cavity of the main valve body 1 and the internal cavity of the pilot valve body 8 are connected to form the main valve chamber. A sealing ring is installed between the main valve body 1 and the pilot valve body 8 to prevent oil leakage. The control end cap 11 is bolted to the rear end of the pilot valve body 8, and a sealing ring is installed at the connection to prevent oil leakage.

[0040] The main valve sleeve 3 is arranged in the cavity inside the main valve body 1. Specifically, a first stepped blind hole is opened at the rear end of the main valve body 1, and the main valve sleeve 3 is fixedly installed in the first stepped blind hole. The design of the first stepped blind hole realizes the axial and radial limiting of the main valve sleeve 3. The main valve sleeve 3 and the main valve body 1 are sealed by an O-ring. An annular groove is opened on the inner wall of the main valve body 1 at a position corresponding to the middle of the main valve sleeve 3, forming a load cavity between the main valve body 1 and the main valve sleeve 3. Several radial through holes are opened in the middle of the main valve sleeve 3 to connect the load cavity with the internal cavity of the main valve sleeve 3. A load port B is opened on the main valve body 1 to connect the external load oil with the load cavity. A port A is opened on the main valve body 1 as the main valve return port.

[0041] The main valve core 2 is a conical slide valve structure, coaxially arranged in the cavity inside the main valve sleeve 3, forming a sliding fit. The main valve core 2 can move flexibly axially without jamming in the through hole of the main valve sleeve 3. Specifically, the cavity between the small-diameter end (the front end in this embodiment) of the main valve core 2 and the main valve body 1 is a back pressure cavity, and the A port on the main valve body 1 communicates with the back pressure cavity. The conical section of the main valve core 2 and the main valve body 1 form a main valve port, which is used to connect the load cavity and the back pressure cavity. When the main valve core 2 is at the front end of its movable range, a conical seal is formed between the main valve core 2 and the main valve sleeve 3, the load cavity and the back pressure cavity are not connected, and the main valve port is closed. When the main valve core 2 moves backward, the main valve port opens, the load cavity and the back pressure cavity are connected, and the displacement of the main valve core 2 determines the opening degree of the main valve port. The large-diameter end of the main valve core 2 (the rear end in this embodiment) has a coaxial second stepped blind hole.

[0042] The pilot valve sleeve 7 is arranged in the main valve cavity, and the pilot valve core 6 is arranged in the cavity inside the pilot valve sleeve 7. Specifically, the pilot valve body 8 has an axially formed first stepped through hole coaxial with the first stepped blind hole. The first stepped through hole includes a first cylindrical hole, a second cylindrical hole, a third cylindrical hole, and a fourth cylindrical hole from front to back. The diameter of the first cylindrical hole is the same as the diameter of the rear end of the first stepped blind hole and the outer diameter of the pilot valve sleeve 8. The inner diameter of the second cylindrical hole is adapted to the outer diameter of the small diameter end (the rear end in this embodiment) of the pilot valve core 6. The pilot valve sleeve 7 is arranged coaxially with the main valve sleeve 3. The front end of the pilot valve sleeve 7 is fixedly arranged in the main valve body 1 and abuts against the rear end of the main valve sleeve 3. The two are sealed together by an O-ring. The rear end of the pilot valve sleeve 7 is fixedly arranged in the first cylindrical hole and is sealed together with the pilot valve body 8 by an O-ring. This combination achieves axial and radial limiting of the pilot valve sleeve 7.

[0043] The pilot valve sleeve 7 has a second stepped through hole coaxially formed inside for coaxially mounting the pilot valve core 6 and for axial and radial limiting of it. The pilot valve sleeve 7 and the pilot valve core 6 form a sliding fit. Specifically, the second stepped through hole includes a cylindrical hole one and a cylindrical hole two from front to back. The diameter of the cylindrical hole one is adapted to the large diameter end of the pilot valve core 6, and the diameter of the cylindrical hole two is adapted to the small diameter end of the pilot valve core 6. The small diameter end of the pilot valve core 6 passes through the pilot valve sleeve 7 and is inserted into the second cylindrical hole of the pilot valve body 8. The pilot valve core 6 and the pilot valve sleeve 7 form the pilot valve port of the pilot large flow balance valve. When the pilot valve core 6 is located at the rearmost end of the movable range, a conical seal is formed between the pilot valve core 6 and the pilot valve sleeve 7, and the pilot valve port is closed.

[0044] The cavity between the small-diameter end of the pilot valve core 6 and the pilot valve sleeve 7 is a transition cavity. A cylindrical hole is radially formed inside the pilot valve body 8 along the radial contact surface between the pilot valve body 8 and the pilot valve sleeve 7. The axis of this cylindrical hole is perpendicular to the axis of the pilot valve body 8, creating a cavity between the pilot valve body 8 and the pilot valve sleeve 7, denoted as the back pressure feedback cavity. When the pilot valve port is open, the back pressure feedback cavity and the transition cavity are connected. A channel is formed inside the main valve body 1 and the pilot valve body 8 connecting the back pressure feedback cavity and the back pressure cavity.

[0045] The pilot valve core 6 and the main valve core 2 are arranged coaxially and in opposite directions, that is, their large-diameter ends are opposite each other. The cavity between the large-diameter end of the main valve core 2, the main valve sleeve 3, the pilot valve sleeve 7, and the large-diameter end of the pilot valve core 6 is the feedback spring cavity. A throttling groove is opened on the main valve core 2 to connect the load cavity and the feedback spring cavity. The feedback spring 4 is axially arranged in the feedback spring cavity, with one end abutting the bottom of the second step blind hole of the main valve core 2 and the other end abutting the large-diameter end of the pilot valve core 6. In the initial state, the feedback spring 4 has a certain preload to ensure that all valve ports (main valve port and pilot valve port) are in a closed state without leakage, and the feedback spring 4 can realize mechanical feedback between the main valve core 2 and the pilot valve core 6, so that the two influence each other.

[0046] like Figure 4As shown, the overcompensation regulating valve 5 includes: a cartridge valve sleeve 5-1, a cartridge valve core 5-2, a preload spring 5-3, a spring baffle 5-4, an overcompensation end cap 5-5, a locking nut 5-6, and an adjusting stud 5-7. The cartridge valve sleeve 5-1 is hollow inside, with external threads on the outer ring and a through hole at the bottom serving as the oil inlet of the overcompensation regulating valve 5. A first flow hole with a cross-sectional shape of "upper circle + lower rectangle" is symmetrically opened on the outer circumferential surface of the lower part of the cartridge valve sleeve 5-1. The intersection width of the circle and the rectangle is the width of the rectangle. This cross-sectional design of the first flow hole increases the accuracy of the flow area change while ensuring the flow rate, and facilitates processing. The cartridge valve core 5-2 is installed in the cavity inside the cartridge valve sleeve 5-1. The cartridge valve core 5-2 is also hollow inside, with two orthogonal second flow holes in the bottom cylinder. The vertical second flow hole is coaxial with the cartridge valve core 5-2 and connects the oil inlet at the bottom of the cartridge valve sleeve 5-1 and the internal cavity of the cartridge valve core 5-2. The overlapping part of the horizontal second flow hole and the first flow hole serves as the oil outlet of the overcompensation regulating valve 5. In the initial state, the horizontal second flow hole and the first flow hole are completely connected, that is, the cartridge valve core 5-2 does not cover the first flow hole in any way, and the flow area of ​​the oil outlet is maximized. The preload spring 5-3 is installed in the internal cavity of the cartridge valve core 5-2. The lower end of the preload spring 5-3 abuts against the bottom of the internal cavity of the cartridge valve core 5-2. The spring baffle 5-4 is installed on the upper end of the preload spring 5-3 and can move axially within the cartridge valve core 5-2. The compensation end cap 5-5 is screwed into the upper opening of the cartridge valve sleeve 5-1 via its external thread. A through hole is coaxially formed inside the compensation end cap 5-5, and the adjusting stud 5-7 is screwed into the through hole of the compensation end cap 5-5 via its external thread. The locking nut 5-6 is fitted around the outer circumference of the adjusting stud 5-7, and the two are threaded together to lock the adjusting stud 5-7. The bottom of the adjusting stud 5-7 is in contact with the upper end face of the spring baffle 5-4, so that the two ends of the preload spring 5-3 abut against the cartridge valve core 5-2 and the spring baffle 5-4 respectively, providing a certain preload force. The preload force of the preload spring 5-3 can be changed by rotating the adjusting stud 5-7.

[0047] Furthermore, O-rings are provided between the cartridge valve sleeve 5-1 and the over-compensation end cap 5-5, and between the over-compensation end cap 5-5 and the locking nut 5-6, to prevent oil leakage.

[0048] The overcompensation regulating valve 5 is installed in the part of the main valve body 1 corresponding to the feedback spring cavity via the external thread sealing the outer circumference of the cartridge valve sleeve 5-1. The outer wall of the valve sleeve (which can be either the pilot valve sleeve 7 or the main valve sleeve 3) corresponding to the feedback spring cavity is provided with a first annular groove, and two symmetrically distributed radial through holes are provided on the first annular groove to communicate with the spring feedback cavity; the inner wall of the main valve body 1 is provided with a first radial hole at the position corresponding to the first annular groove, so that the spring feedback cavity is connected to the oil inlet of the overcompensation regulating valve 5.

[0049] A second annular groove is provided on the outer wall of the rear end of the pilot valve sleeve 7, and several symmetrically distributed second radial holes are provided on the second annular groove to communicate with the transition cavity. A channel is provided inside the main valve body 1 and the pilot valve body 8 to connect the second annular groove and the oil outlet of the overcompensation regulating valve 5. A pressure measuring port E is provided on the pilot valve body 8 to communicate with the channel, and is used to measure the oil outlet pressure of the overcompensation regulating valve 5.

[0050] A third annular groove is formed on the outer wall of the middle part of the pilot valve sleeve 7 as a quick-closing chamber. Two symmetrically distributed third radial holes are formed on the third annular groove to communicate with the cavity inside the pilot valve sleeve 7. A channel is formed inside the main valve body 1 to connect the load chamber and the quick-closing chamber. When the pilot valve core 6 is in the initial position (i.e. when the pilot valve port is closed), the feedback spring chamber is connected to the load chamber through the quick-closing chamber. When the pilot valve port is open, the quick-closing chamber and the feedback spring chamber are not connected.

[0051] Furthermore, O-ring seals are installed between each radial hole and annular groove to ensure no leakage between cavities.

[0052] Inside the pilot valve body 8, in the first stepped through-hole, a ring-shaped baffle is coaxially fixed to the third cylindrical hole near the second cylindrical hole. The ring-shaped baffle has a through-hole at its center with a diameter identical to the inner diameter of the second cylindrical hole. This ring-shaped baffle prevents the pressure in the back pressure feedback chamber from affecting the force on the control piston 10. The control piston 10 is installed in the third and fourth cylindrical holes, forming a sliding fit with the pilot valve body 8. The disc portion of the control piston 10 is located at the rear and abuts against the control end cover 11, while the shaft portion is located at the front and is coaxially and abuts against the small-diameter end of the pilot valve core 6. Initially, there is a clearance between the shaft portion of the control piston 10 and the small-diameter end of the pilot valve core 6 to ensure that the initial position of the pilot valve core 6 is not affected by the control piston 10. The cavity between the control piston 10 and the second and third cylindrical holes is a pilot spring cavity. A pilot spring 9 is installed in the pilot spring cavity, with one end of the pilot spring 9 abutting against the disc of the control piston 10 and the other end abutting against the front end face of the third cylindrical hole. In the initial state, the pilot spring 9 has a certain preload to ensure that the control piston 10 is in the closed state. A pilot drain port L is provided on the outer wall of the pilot valve body 8, communicating with the pilot spring cavity.

[0053] A pilot control chamber is formed between the control end cover 11 and the control piston 10. A flow channel is formed inside the control piston 10 to connect the pilot control chamber with the pilot spring chamber. An X-port is formed on the control end cover 11 to connect the external pilot control pressure source with the pilot control chamber. A pressure measuring port E is formed to measure the pressure of the pilot control oil.

[0054] like Figure 5 and Figure 6As shown, when the balance valve opens in reverse, the load oil flows back to port A on the main valve body 1 through the load port, load chamber, feedback spring chamber, overcompensation regulating valve 5, and pilot valve port on the pilot valve core 6. Since the oil flow through the inlet and outlet of the compensation regulating valve 5 generates a pressure difference, this pressure difference acts on the two ends of the pilot valve core 6 (the frontmost end and the annular end at the pilot valve port), in the direction of pilot valve port closure. The larger the load, the greater the pressure difference, and the greater the closing force. When the pressure difference force on the pilot valve core 6 is greater than the thrust of the control piston 10 on the pilot valve core 6, the pilot valve core 6 moves backward to close the pilot valve port, and the main valve core 2 closes accordingly. The flow rate through the main valve port on the main valve core 2 decreases. That is, when the pilot control pressure is constant, after the load pressure exceeds a certain value, the main flow rate of the balance valve decreases as the load pressure increases, achieving overcompensation.

[0055] Furthermore, the load pressure acts on the cartridge valve core 5-2 of the overcompensation regulating valve 5, with the resultant force pointing upwards. When the hydraulic pressure acting on the cartridge valve core 5-2 is greater than the preload of the preload spring 5-3, the cartridge valve core 5-2 moves upwards, the flow area of ​​the oil outlet decreases, the pressure difference between the two ends of the pilot valve core 6 increases, and the closing force of the pilot valve core 6 increases. The greater the load, the greater the upward displacement of the cartridge valve core 5-2, the smaller the flow area of ​​the oil outlet of the overcompensation regulating valve 5, the greater the closing force of the pilot valve core 6, and the greater the overcompensation effect, thus achieving adaptive adjustment of the overcompensation effect. By adjusting the preload of the overcompensation valve 5, the pressure inflection point of the balance valve overcompensation can be changed. The smaller the preload, the earlier the pressure inflection point, and the greater the overcompensation rate.

[0056] In the case of overloaded discharge conditions, the overcompensation adaptive regulating valve can automatically reduce the flow area of ​​the oil outlet as the load increases, thereby automatically increasing the overcompensation effect. By adjusting the preload on the overcompensation regulating valve, the overcompensation pressure inflection point can be changed, making it suitable for various needs.

[0057] It will be understood by those skilled in the art that the above descriptions are merely preferred examples of the invention and are not intended to limit the invention. Although the invention has been described in detail with reference to the foregoing examples, those skilled in the art can still modify the technical solutions described in the foregoing examples or make equivalent substitutions for some of the technical features. All modifications and equivalent substitutions made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A balancing valve with an overcompensation adaptive regulating valve, characterized in that, include: The main valve body, pilot valve body, and control end cover are arranged coaxially from front to back. The main valve sleeve and the pilot valve sleeve are coaxially and tightly arranged in the internal cavities of the main valve body and the pilot valve body. The main valve core is coaxially and slidably arranged in the cavity inside the main valve sleeve, and the pilot valve core is coaxially and slidably arranged in the cavity inside the pilot valve sleeve. One end of the feedback spring abuts against the large diameter end of the main valve core, and the other end abuts against the large diameter end of the pilot valve core. The main valve body has a load port B to supply load oil to the load chamber, and a main valve return port A. The control piston is coaxially slidably arranged in the rear cavity of the pilot valve body. The small-diameter end of the pilot valve core passes through the pilot valve sleeve and is coaxially mounted with the shaft of the control piston. One end of the pilot spring abuts against the control piston, and the other end abuts against the pilot valve body. The pilot valve body has a pilot drain port L that communicates with the pilot spring cavity. The control end cover has an X port to supply pilot control pressure oil to the pilot spring cavity. The main valve body is equipped with a compensation regulating valve, whose oil inlet is connected to the feedback spring cavity and whose oil outlet is connected to the front cavity of the pilot valve port. The flow area of ​​the oil outlet is adaptively adjusted according to the load size. The rear cavity of the pilot valve port is connected to port A. The overcompensation regulating valve includes: a cartridge valve sleeve, a cartridge valve core, a preload spring, a spring baffle, an overcompensation end cap, a lock nut, and an adjusting stud; The cartridge valve sleeve is installed in the main valve body. It is hollow inside, with an oil inlet at the bottom and first flow holes symmetrically opened on the lower outer circumference. The cartridge valve core is installed in the cavity inside the cartridge valve sleeve. The cavity is hollow inside. Two orthogonal second flow holes are opened in the bottom body. The vertical second flow hole is coaxial with and connected to the oil inlet. The overlapping part of the horizontal second flow hole and the first flow hole serves as the oil outlet of the overcompensation regulating valve. In the initial state, the second transverse flow hole is fully connected to the first flow hole, and the flow area of ​​the oil outlet is the largest. The preload spring is installed in the internal cavity of the cartridge valve core, and the spring baffle is installed inside the cartridge valve core and can move axially. The lower end of the preload spring abuts against the bottom of the internal cavity of the cartridge valve core, and the upper end abuts against the lower end face of the spring baffle. The overcompensation end cap is fixedly installed at the upper opening of the cartridge valve sleeve, with a coaxial through hole in its center. The adjusting stud is threaded into the through hole to be screwed in or out. The bottom of the adjusting stud is in contact with the upper end face of the spring baffle. The preload of the preload spring is changed by rotating the adjusting stud. The locking nut is sleeved on the outer circumference of the adjusting stud to lock the adjusting stud.

2. The balancing valve with overcompensation adaptive regulating valve according to claim 1, characterized in that, The cross-section of the first flow hole is circular in the upper half and rectangular in the lower half, and the intersection width of the upper and lower parts is the width of the rectangle.

3. The balance valve with overcompensation adaptive regulating valve according to claim 1, characterized in that, A first annular groove is provided on the outer wall of the valve sleeve corresponding to the feedback spring cavity, and two symmetrically distributed radial through holes are provided on the first annular groove to communicate with the spring feedback cavity; a first radial hole is provided on the inner wall of the main valve body at a position corresponding to the first annular groove, so that the spring feedback cavity is connected to the oil inlet of the overcompensation regulating valve.

4. The balancing valve with overcompensation adaptive regulating valve according to claim 1, characterized in that, The main valve body has a first stepped blind hole at its rear end, and the main valve sleeve is arranged in the first stepped blind hole. The pilot valve body has a first stepped through hole axially coaxial with the first stepped blind hole. The first stepped through hole includes a first cylindrical hole, a second cylindrical hole, a third cylindrical hole, and a fourth cylindrical hole from front to back. The diameter of the first cylindrical hole is the same as the diameter of the rear end of the first stepped blind hole, and the diameter of the second cylindrical hole is adapted to the outer diameter of the small diameter end of the pilot valve core. The front end of the pilot valve sleeve is arranged in the main valve body and abuts against the rear end of the main valve sleeve. The rear end of the pilot valve sleeve is arranged in the first cylindrical hole, which cooperates to realize the axial and radial limiting of the main valve sleeve and the pilot valve sleeve. The control piston and feedback spring are arranged in the third cylindrical hole and the fourth cylindrical hole, with one end of the feedback spring abutting against the disc of the control spring and the other end abutting against the front end face of the third cylindrical hole.

5. The balancing valve with overcompensation adaptive regulating valve according to claim 4, characterized in that, An annular partition is coaxially fixed to the third cylindrical hole near the second cylindrical hole, and a through hole with the same diameter as the inner diameter of the second cylindrical hole is opened in the center of the annular partition. In the initial state, the control piston is in the closed state, and there is a gap between the shaft of the control piston and the small-diameter end of the pilot valve core.

6. The balancing valve with overcompensation adaptive regulating valve according to claim 1, characterized in that, An annular groove is formed on the inner wall of the main valve body at a position corresponding to the middle of the main valve sleeve, forming a load cavity between the main valve body and the main valve sleeve; several radial through holes are formed in the middle of the main valve sleeve along the circumference, connecting the load cavity with the internal cavity of the main valve sleeve. The cavity between the small-diameter end of the main valve core and the main valve body is the back pressure cavity. The main valve return port A on the main valve body is connected to the back pressure cavity. The load cavity and the back pressure cavity are connected through the main valve port. A throttling groove on the main valve core connects the load cavity and the feedback spring cavity.

7. The balancing valve with overcompensation adaptive regulating valve according to claim 1, characterized in that, The pilot valve core's small-diameter end and the pilot valve sleeve form a pilot valve port, and the front cavity of the pilot valve port is a transition cavity; a second annular groove is provided on the rear outer wall of the pilot valve sleeve, and several symmetrically distributed second radial holes are provided on the second annular groove to communicate with the transition cavity; a channel is provided inside the main valve body and the pilot valve body to connect the second annular groove and the oil outlet of the overcompensation regulating valve. The rear cavity of the pilot valve port is a back pressure feedback cavity; a cylindrical hole is radially opened inside the pilot valve body along the radial contact surface between the pilot valve body and the pilot valve sleeve, and the axis of the cylindrical hole is perpendicular to the axis of the pilot valve body, so that a cavity is formed between the pilot valve body and the pilot valve sleeve, which is the back pressure feedback cavity; a channel is opened inside the main valve body and the pilot valve body to connect the back pressure feedback cavity and the main valve return port A.

8. The balancing valve with overcompensation adaptive regulating valve according to claim 1, characterized in that, A third annular groove is provided on the outer wall of the middle part of the pilot valve sleeve as a quick-closing chamber. Two symmetrically distributed third radial holes are provided on the third annular groove to communicate with the cavity inside the pilot valve sleeve. A channel is provided inside the main valve body to connect the load chamber and the quick-closing chamber. When the pilot valve core is in the initial position, the pilot valve port is closed, and the feedback spring chamber is connected to the load chamber through the quick-closing chamber. When the pilot valve port is open, the quick-closing chamber and the feedback spring chamber are not connected.

9. The balancing valve with overcompensation adaptive regulating valve according to claim 1, characterized in that, A pilot control chamber is formed between the control end cover and the control piston. A flow channel is formed inside the control piston to connect the pilot control chamber with the pilot spring chamber. An X-port is formed on the control end cover to connect the external pilot control pressure source with the pilot control chamber. A pressure measuring port E is formed to measure the pressure of the pilot control oil.

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