A large flow balancing valve with a flow regulator

Abstract

The present invention discloses a high-flow balancing valve with a flow regulator. The valve comprises a main valve body, a pilot valve body, and a control end cap, arranged axially from front to back, and a main valve core, a pilot valve core, and a control piston coaxially arranged within an internal cavity. The flow regulator is inserted into the pilot valve body, connecting the pilot oil return channel and the backpressure chamber, and capable of regulating the flow in the channel. The present invention utilizes the flow regulator to regulate and limit the flow of the balancing valve, making it suitable for both high-flow and low-flow operating conditions. Furthermore, under low-load conditions, when the balancing valve's compensation inflection point is not reached and the overcompensation characteristic is not fully utilized, the inflection point of the overcompensation characteristic can be controlled within a certain range, thereby improving the adaptability of the high-flow balancing valve.

Description

Technical Field

[0001] The present invention relates to the field of hydraulic control, in particular to a large flow balancing valve with a flow regulator. Background Art

[0002] Most construction machinery today is hydraulic, relying on internal hydraulic systems and oil circuit control to complete complex operating conditions. During operation, when the load force and direction of motion coincide, the actuator or load may stall or slide due to its own weight. In engineering applications, a balancing valve is often installed before the hydraulic cylinder's oil return line. This valve utilizes the pressure differential generated by the oil flowing through the valve port to balance the cylinder's back pressure and gravity load, controlling the lowering speed of the actuator or load and playing a crucial role in critical movements.

[0003] The static and dynamic performance of a balancing valve directly impacts the system's ability to lift, hold, and lower loads, further impacting overall system performance. Traditional balancing valves treat these characteristics as inherent features. When the balancing valve's structural dimensions remain unchanged, the pressure-flow curve remains constant. Under low-load or low-flow conditions, balancing valves of the same size and specification may not offer good adaptability. Summary of the Invention

[0004] In view of the deficiencies in the prior art, the present invention proposes a large flow balancing valve with a flow regulator.

[0005] The specific technical solutions are as follows:

[0006] A large flow balancing valve with a flow regulator comprises a main valve body, a pilot valve body, and a control end cover, which are arranged axially in sequence from front to back, and the three constitute a main valve body; the main valve body and the pilot valve body are both provided with axial cavities and are interconnected; the main valve sleeve is arranged in the cavity in the main valve body; annular grooves are provided on the inner walls corresponding to the middle of the main valve body and the main valve sleeve, forming a load chamber between the main valve body and the main valve sleeve; a load port B is provided on the main valve body to connect the outside with the load chamber; a plurality of radial through holes are provided in the middle of the main valve sleeve to connect the load chamber with the internal cavity of the main valve sleeve; the front end of the pilot valve sleeve is arranged in the cavity in the main valve body and is coaxially and tightly attached to the main valve sleeve, and the rear end of the pilot valve sleeve is arranged in the front part of the cavity in the pilot valve body;

[0007] The main valve core is coaxially slidably arranged in the cavity in the main valve sleeve, and the pilot valve core is coaxially slidably arranged in the cavity in the pilot valve sleeve; the main valve core and the pilot valve core are coaxially and oppositely arranged, and the large diameter end of the main valve core is opposite to the large diameter end of the pilot valve core, and a feedback cavity is formed among the main valve core, the pilot valve core, the main valve sleeve and the pilot valve sleeve, and a throttling groove is provided on the main valve core to connect the load cavity and the feedback cavity; one end of the feedback spring is against the large diameter end of the main valve core, and the other end is against the large diameter end of the pilot valve core; the small diameter end of the main valve core is against the main valve body The cavity between the two is the back pressure cavity, and the oil port A is provided on the main valve body to connect the outside with the back pressure cavity; in the initial state of the balancing valve, the main valve core is located at the front end of the axial limit and forms a conical surface seal between the main valve sleeve, the main valve port is closed, and the pilot valve core is located at the rear end of the axial limit and forms a conical surface seal between the pilot valve sleeve, and the pilot valve port is closed; a transition cavity is formed between the small diameter end of the pilot valve core and the cavity inside the pilot valve sleeve, and a coaxial channel is provided inside the pilot valve core to connect with the transition cavity, and an over-compensation damper is installed in the channel;

[0008] A channel is provided in the pilot valve sleeve and the main valve body, so that when the pilot valve port is closed, the load port B is connected to the feedback chamber; a pilot oil return channel is formed between the rear end of the pilot valve sleeve and the pilot valve body, and when the pilot valve port is opened, the pilot oil return channel is connected to the transition chamber, and the load port B is not connected to the feedback chamber; the adjusting stud is installed in a mounting hole provided on the side wall of the pilot valve body and connected to the pilot oil return channel, and its axial mounting depth is adjustable within a certain range; an annular groove is provided on the outer wall of the adjusting stud, a blind hole is provided coaxially at the mounting end, and a cylindrical small hole is provided inside to connect the annular groove and the blind hole; an axial flow channel is provided inside the main valve body to connect the back pressure chamber and the annular groove on the adjusting stud, and the connecting port between the adjusting stud and the axial flow channel is the valve port of the adjusting mechanism, and its flow cross-section changes with the adjustment of the mounting depth of the adjusting stud;

[0009] The control piston is coaxially arranged at the rear part of the cavity in the pilot valve body. Under the action of the pilot control spring, the disc of the control piston is in contact with the control end cover and a pilot control cavity is left between the two. The small-diameter end of the pilot valve core passes through the pilot valve sleeve and is installed opposite to the shaft of the control piston. The cavity between the control piston and the pilot valve body is the oil drain cavity. The pilot valve body is provided with an oil port L to connect the outside world with the oil drain cavity. The control end cover is provided with an X port to connect the outside world with the pilot control cavity, and a damper is arranged in the channel. The pilot control cavity and the oil drain cavity are connected through a channel provided in the control piston, and a damper is arranged in the channel.

[0010] Furthermore, the main valve core comprises, from front to back, a coaxial damping tail structure, a tapered section, and a cylindrical section. The connection between the cylindrical section and the tapered section and the main valve sleeve forms the main valve port of the pilot large-flow balancing valve. In the initial state of the balancing valve, the main valve core is located at the front end of the axial limit, and a conical surface seal is formed between the connection between the cylindrical section and the tapered section and the main valve sleeve. The main valve port is closed, and the back pressure chamber and the load chamber are not connected. When the main valve core moves backward, the main valve port is opened, and the back pressure chamber and the load chamber are connected.

[0011] The throttling groove is symmetrically arranged at the tail end of the outer circumference of the cylindrical section of the main valve core. The throttling groove includes a U-shaped groove and a feedback throttling groove arranged in sequence from front to back and connected to each other, and the depth and width of the feedback throttling groove are both smaller than the U-shaped groove. The throttling groove is used to connect the load chamber and the feedback chamber, and the end surface where the throttling groove is connected to the feedback chamber forms a feedback valve port.

[0012] Furthermore, a first stepped through hole is axially provided inside the pilot valve body, and the first stepped through hole comprises, from front to back, a first cylindrical hole, a second cylindrical hole, a third cylindrical hole, and a fourth cylindrical hole;

[0013] The rear end of the pilot valve sleeve is installed in the first cylindrical hole. The first cylindrical hole is used to limit the pilot valve sleeve axially and radially. The inner diameter of the first cylindrical hole is the same as the outer diameter of the pilot valve sleeve, and the pilot valve sleeve and the first cylindrical hole are sealed by a sealing ring.

[0014] The inner diameter of the second cylindrical hole is adapted to the outer diameter of the small diameter end of the pilot valve core extending out of the outside of the pilot valve sleeve; an annular partition is coaxially fixedly connected to the position connected to the second cylindrical through hole in the third cylindrical hole, and a through hole adapted to the outer diameter of the shaft of the control piston is opened on the annular partition; the shaft of the control piston and the small diameter end of the pilot valve core are coaxially mounted opposite each other in the through hole inside the annular partition, and a gap is left between the shaft of the control piston and the small diameter end of the pilot valve core in the initial state of the balancing valve; the pilot control spring is installed between the disk of the control piston and the annular partition, one end of which rests against the front end of the third cylindrical hole, and the other end rests against the control piston; and the inner diameter of the third cylindrical hole is adapted to the outer diameter of the pilot control spring; the inner diameter of the fourth cylindrical hole is adapted to the outer diameter of the disk of the control piston.

[0015] Furthermore, sealing is achieved between the main valve body and the pilot valve body, between the main valve sleeve and the main valve body, between the pilot valve sleeve and the main valve body, between the pilot valve sleeve and the pilot valve body, and between the main valve sleeve and the pilot valve sleeve by sealing rings.

[0016] Furthermore, the overcompensation damper, the damper arranged in the channel between the X port and the pilot control chamber, and the damper arranged in the channel between the pilot control chamber and the oil drain chamber are all sleeve structures with a small through hole opened in the axis, and are installed in each channel by threaded rotation.

[0017] Furthermore, a pilot oil return channel is formed between the rear end of the pilot valve sleeve and the pilot valve body. Specifically, a cylindrical hole is radially opened inside the pilot valve body along the contact surface of the pilot valve body and the pilot valve sleeve perpendicular to the axis, so that a cavity is formed between the pilot valve body and the pilot valve sleeve, which is recorded as the pilot oil return channel.

[0018] Furthermore, a channel is provided in the pilot valve sleeve and the main valve body so that when the pilot valve port is closed, the load port B is connected with the feedback chamber. Specifically, an annular groove is provided on the outer wall of the middle portion of the pilot valve sleeve as a quick-closing chamber, and symmetrically distributed radial through holes are provided along the annular groove to connect the quick-closing chamber with the internal cavity of the pilot valve body. A channel is provided inside the main valve body to connect the quick-closing chamber with the load port B; and when the pilot valve port is closed, the quick-closing chamber is connected with the feedback chamber. When the pilot valve port is opened, the channel between the quick-closing chamber and the feedback chamber is covered, and the quick-closing chamber and the feedback chamber are not connected.

[0019] The beneficial effects of the present invention are:

[0020] For low-flow or light-load applications, the high-flow balancing valve proposed in this invention can limit flow through a flow regulator, controlling and adjusting the flow rate and compensation characteristics of the main valve port. When high-flow applications are required, the regulating mechanism is adjusted to restore the original flow characteristics. Furthermore, under light-load conditions, if the balancing valve's compensation inflection point is not reached and the overcompensation characteristic is not fully utilized, the flow regulator can control the inflection point of the overcompensation characteristic within a certain range, making the high-flow balancing valve more adaptable. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a front view of a large flow balancing valve with a flow regulator in an embodiment of the present invention.

[0022] Figure 2 It is an AA cross-sectional view of a large flow balancing valve with a flow regulator in an embodiment of the present invention.

[0023] Figure 3 1 is a top view of a large flow balancing valve with a flow regulator in an embodiment of the present invention.

[0024] Figure 4 It is a BB cross-sectional view of a large flow balancing valve with a flow regulator in an embodiment of the present invention.

[0025] Figure 5 It is a partial enlarged view of the adjustment mechanism in the embodiment of the present invention.

[0026] Figure 6 Schematic diagram of the structure of the main valve core in an embodiment of the present invention.

[0027] Figure 7This is a schematic diagram of the working state and oil flow direction of a large flow balancing valve with a flow regulator in an embodiment of the present invention when the load is lowered, from the AA cross-sectional perspective.

[0028] Figure 8 3 is a comparative curve diagram of the over-compensation characteristics of the throttle valve core under different displacements and control pressures in an embodiment of the present invention.

[0029] In the figure, main valve body 1, main valve core 2, main valve sleeve 3, feedback spring 4, axial flow channel 5, pilot valve sleeve 6, pilot valve core 7, pilot valve body 8, adjusting stud 9, adjusting mechanism valve port 10, pilot control spring 11, control piston 12, control end cover 13, pilot control chamber 14, oil drain chamber 15, pilot return oil channel 16, transition chamber 17, overcompensation damping 18, quick closing chamber 19, feedback chamber 20, load chamber 21, back pressure chamber 22, pilot return oil damping 23, and pilot inlet damping 24. DETAILED DESCRIPTION

[0030] The present invention will be described in detail below based on the accompanying drawings and preferred embodiments. The purpose and effects of the present invention will become more apparent. The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0031] like Figures 1-4 As shown, a high-flow balancing valve with a flow regulator comprises: a main valve body 1, a main valve core 2, a main valve sleeve 3, a feedback spring 4, a pilot valve sleeve 6, a pilot valve core 7, a pilot valve body 8, an adjusting stud 9, a pilot control spring 11, a control piston 12, and a control end cap 13. The main valve body 1, the pilot valve body 8, and the control end cap 13 are arranged axially from left to right. The main valve body 1 and the pilot valve body 8 together form the main valve body. The internal cavity of the main valve body 1 communicates with the internal cavity of the pilot valve body 7, forming the internal volume of the main valve body. The main valve body 1 and the pilot valve body 8 are fixed by bolts and equipped with a sealing ring to prevent leakage. The control end cap 13 is bolted to the right end of the pilot valve body 8. A central hole is axially defined in the control end cap 13, serving as the control port X of the balancing valve. A sealing ring is installed at the connection between the control end cap 13 and the pilot valve body 8 to prevent leakage. The internal structure of the main valve body is designed with multiple cavities, which work together to control the flow and pressure of the balancing valve.

[0032] Specifically, the main valve body 1 has a first blind hole defined at its right end. The main valve sleeve 3 is installed in the first blind hole and is axially limited. The main valve sleeve 3 and the main valve body 1 are sealed by a sealing ring. The main valve core 2 is coaxially installed in a through hole coaxially defined within the main valve sleeve 3. A sliding fit is formed between the main valve core 2 and the main valve sleeve 3. The main valve core 2 can move axially flexibly within the through hole of the main valve sleeve 3 within a limited range without getting stuck. The small-diameter end of the main valve core 2 is on the left, and the large-diameter end is on the right. The cavity between the outside of the small-diameter end of the main valve core 2 and the main valve body 1 forms a back-pressure chamber 22. An oil port A is radially defined on the inner wall of the main valve body 1 surrounding the back-pressure chamber 22 to connect the outside with the back-pressure chamber 22. An annular groove is provided on the inner wall corresponding to the middle position of the main valve body 1 and the main valve sleeve 3, and a plurality of radial through holes are provided in the middle position of the main valve sleeve 3 to connect the annular groove with the cavity inside the main valve sleeve 3; the cavity between the main valve core 2, the main valve sleeve 3 and the inner wall of the main valve body 1 forms a load cavity 21, and a load port B is radially provided on the inner wall of the main valve body 1 corresponding to the load cavity 21 to connect the outside with the load cavity 21.

[0033] A first stepped through-hole is axially defined within the pilot valve body 8, coaxial with the first blind hole. From left to right, the first stepped through-hole comprises a first cylindrical hole, a second cylindrical hole, a third cylindrical hole, and a fourth cylindrical hole. The inner diameter of the first cylindrical hole is identical to the outer diameter of the pilot valve sleeve 6, while the inner diameter of the second cylindrical hole matches the outer diameter of the small-diameter end of the pilot valve core 7. The pilot valve sleeve 6 is coaxially arranged with the main valve sleeve 3. The left end of the pilot valve sleeve 6 is mounted in the first blind hole and tightly abuts the right end of the main valve sleeve 3. The right end of the pilot valve sleeve 6 is mounted in the first cylindrical hole of the pilot valve body 8 and is axially constrained. Sealing rings are used to seal the pilot valve sleeve 6 and the main valve body 1, the pilot valve sleeve 6 and the pilot valve body 8, and the main valve sleeve 3 and the pilot valve sleeve 6, ensuring leakage-free operation within each chamber.

[0034] A through-hole is coaxially defined within the pilot valve sleeve 6, and a pilot valve core 7 is coaxially mounted within the pilot valve sleeve 6. The pilot valve core 7 and the pilot valve sleeve 6 form a sliding fit, allowing the pilot valve core 7 to move axially freely within the through-hole within the pilot valve sleeve 6 within a limited range without binding. The pilot valve core 7 and the main valve core 2 are coaxially arranged in opposite directions, with the large-diameter end of the pilot valve core 7 on the left and the small-diameter end on the right. The cavity between the large-diameter end of the main valve core 2, the main valve sleeve 3, the pilot valve sleeve 6, and the large-diameter end of the pilot valve core 7 forms a feedback chamber 20. A feedback spring 4 is located within the feedback chamber 20, with the bottom of a second blind hole defined in the large-diameter end of the main valve core 2 and its other end resting against the left side of the pilot valve core 9. Initially, the feedback spring 4 has a certain preload, ensuring that all valve ports are tightly closed and leak-free. Furthermore, the feedback spring 4 provides mechanical feedback between the main valve core 2 and the pilot valve core 7, allowing them to influence each other. The cavity between the small-diameter end of the pilot valve core 7 and the inner cavity of the pilot valve sleeve 6 forms a transition chamber 17. A cylindrical blind hole is coaxially defined at the left end of the pilot valve core 2, and an overcompensating damper 18 is installed in this cylindrical blind hole. This cylindrical blind hole communicates with the transition chamber 17, thereby connecting the feedback chamber 20 with the transition chamber 17. A tapered section is provided in the middle of the small-diameter end of the pilot valve core 7. This tapered section and the pilot valve sleeve 6 form the pilot valve port of the pilot high-flow balancing valve. The small-diameter end of the pilot valve core 7 passes through the pilot valve sleeve 6 and is inserted into the second cylindrical hole of the pilot valve body 8.

[0035] Along the contact surface between the pilot valve body 8 and the pilot valve sleeve 6 (the contact surface is perpendicular to the axis), a cylindrical hole is radially opened inside the pilot valve body 8. The axis of the cylindrical hole is perpendicular to the axis of the pilot valve body 8, so that a cavity is formed between the pilot valve body 8 and the pilot valve sleeve 6, which is recorded as the pilot oil return channel 16. Based on the cylindrical hole opened in the side wall of the pilot valve body 8, a mounting hole is opened on the same axis and connected to the pilot oil return channel 16. The flow regulator is installed inside the mounting hole. A partial enlarged view of the flow regulator is shown in FIG. Figure 5As shown, the flow regulator includes a locking nut, an adjusting stud 9 and various structures provided therein. Specifically, a through hole is coaxially provided in the locking nut to fix the installation position of the adjusting stud 9. A thread is provided on the inner periphery of the installation hole of the pilot valve body 8, and a matching thread is provided on the outer periphery of the adjusting stud 9. The adjusting stud 9 passes through the locking nut and is screwed into the installation hole. Its axial position (i.e., the installation depth) can be adjusted within a certain range by rotation, and the locking nut plays a role of radial limiting. A third blind hole is coaxially provided at one end (i.e., the installation end) of the adjusting stud 9 that is screwed into the installation hole. An annular groove is provided at the upper middle position of the outer wall of the adjusting stud 9. A cylindrical hole is provided inside the adjusting stud 9 to connect the annular groove and the third blind hole. The third blind hole, the cylindrical hole, and the annular groove together constitute the internal flow channel of the adjusting stud 9. An axial flow channel 5 is defined within the main valve body 1 and the pilot valve body 8. One end of this axial flow channel 5 communicates with the back-pressure chamber 22, and the other end communicates with the annular groove on the adjusting stud 9. The connection between the cylindrical orifice and the axial flow channel 5 is referred to as the regulating mechanism valve port 10. As the adjusting stud 9 rotates, the flow cross-section of the regulating mechanism valve port 10 changes, thereby adjusting the flow rate through the internal flow channel of the adjusting stud 9. When the pilot valve port is open, the pilot return oil channel 16 and the transition chamber 17 are connected via the pilot valve port. As oil returns from the pilot return oil channel 16 to the back-pressure chamber 22, a pressure differential is created between the feedback chamber 20 and the pilot return oil channel 16, generating a force that closes the pilot valve core 7, thereby affecting the opening size of the main valve port.

[0036] A third annular groove is defined on the central outer wall of the pilot valve sleeve 6, serving as the quick-closing chamber 19. Two symmetrically distributed radial through-holes are provided in this third annular groove, communicating with the cavity within the pilot valve body 8. An internal passage is also defined within the main valve body 1 at a position corresponding to the third annular groove, connecting the quick-closing chamber 19 with the load chamber 21. In the initial state of the balancing valve, the pilot valve core 7 is located at the rightmost end of the axial limit, forming a conical seal with the pilot valve sleeve 6. The pilot valve port is closed, the transition chamber 17 is disconnected from the pilot oil return passage 16, and the quick-closing chamber 19 is connected to the feedback chamber 20. When the pilot valve core 7 moves to the left, the pilot valve port opens, and the transition chamber 17 communicates with the pilot oil return passage 16. The displacement of the pilot valve core 7 determines the opening of the pilot valve port. At the same time, as the pilot valve core 7 moves, the cylindrical surface of the large-diameter end of the pilot valve core 7 covers the quick-closing chamber 19. At this time, there is no step gap between the pilot valve sleeve 6 and the pilot valve core 7, and the feedback chamber 20 is disconnected from the quick-closing chamber 19. When the control pressure decreases, the pilot valve core 7 moves to the right, the pilot valve port is closed, and the pressure in the feedback chamber 20 increases. When the pilot valve core 7 moves to the right until there is no step gap between the pilot valve sleeve 6 and the pilot valve core 7, that is, the quick-closing valve port is opened, the pressure in the load chamber 21 can directly pass through the quick-closing chamber 19 to the feedback chamber 20, causing the pressure in the feedback chamber 20 to quickly rise to the load pressure, pushing the main valve core 2 to close quickly, giving the balancing valve a quick-closing characteristic.

[0037] like Figure 6 As shown, the main valve core 2 comprises, axially from left to right, a damping tail structure at the left end, a tapered section in the middle, and cylindrical sections 1 and 2 at the right end. The main valve port of the balancing valve is formed between the cylindrical and tapered sections of the main valve core 2 and the main valve sleeve 3. When the main valve core 2 is at the far left, a conical seal is formed between the cylindrical and tapered sections of the main valve core 2 and the main valve sleeve 3, i.e., the main valve port is closed, and the back-pressure chamber 22 and the load chamber 21 are disconnected. When the main valve core 2 moves to the right, the main valve port opens, connecting the back-pressure chamber 22 and the load chamber 21, and the displacement of the main valve core 2 determines the opening degree of the main valve port. Two throttling grooves are symmetrically arranged at the rear end of the cylindrical outer circumference of the main valve core 2. These throttling grooves comprise a U-shaped groove and a feedback throttling groove, arranged sequentially from left to right and interconnected. The depth and width of the feedback throttling groove are significantly smaller than those of the U-shaped groove. The throttling grooves connect the load chamber 21 and the feedback chamber 20, and the end surfaces where the throttling grooves communicate with the feedback chamber 20 form the feedback valve port. Under the action of the load pressure input from port B, if the opening of the main valve core 2 is excessive, the pressure differential generated by the connection between the load chamber 21 and the feedback chamber 20 through the throttling groove will push the main valve core 2 toward the closing direction of the main valve port due to the force generated by the effective area, thereby achieving hydraulic limit when the load pressure is excessive, ensuring system safety.

[0038] In the first stepped through-hole defined within the pilot valve body 8, an annular baffle is coaxially fixedly connected at a position within the third cylindrical hole near the second cylindrical through-hole, and a through-hole is defined within the annular baffle. The function of the annular baffle is to prevent the pressure within the pilot oil return passage 16 from affecting the force applied to the control piston 12. The control piston 12 is installed in the first stepped through-hole, forming a sliding fit with the pilot valve body 8. The disc portion of the control piston 12 is located on the right side, abutting against the control end cover 13. The shaft portion of the control piston 12 is located on the left side, coaxially mounted opposite the small-diameter end of the pilot valve core 7 in the through-hole within the annular baffle, forming a sliding fit between the control piston 12 and the pilot valve body 8. In the initial state, there is a gap between the shaft portion of the control piston 12 and the small-diameter end of the pilot valve core 7 to ensure that the initial position of the pilot valve core 7 is not affected by the control piston 12. The pilot control spring 11 is installed between the disc of the control piston 12 and the annular diaphragm. One end of the spring abuts the bottom of the third cylindrical hole (i.e., its leftmost end), and the other end abuts the control piston 12. Initially, the pilot control spring 11 exerts a certain preload, ensuring that the control piston 12 is closed. The inner diameter of the third cylindrical hole matches the outer diameter of the pilot control spring 11 installed therein. The outer diameter of the annular diaphragm is smaller than the third cylindrical hole, and the gap between the annular diaphragm and the third cylindrical hole matches the wall thickness of the pilot control spring 11. The diameter of the internal through-hole of the annular diaphragm matches the outer diameter of the smaller end of the control piston 12, and the inner diameter of the fourth cylindrical hole matches the outer diameter of the disc of the control piston 12, enabling axial movement of the control piston 12. The cavity between the annular diaphragm and the control piston 12 of the pilot valve body 8 forms an oil drain chamber 15. An L oil port is provided on the outer wall of the pilot valve body 8, connecting the oil drain chamber 15 to the outside world. The right end of the control piston 12 is concave, forming a conical cavity between it and the control end cap 13 as the pilot control chamber 14. An axial through-hole is provided on the end face of the control end cap 13, connecting to the pilot control chamber 14. This through-hole serves as the X-port of the pilot high-flow balancing valve, and a pilot inlet damper 24 is installed in this X-port. A flow channel is provided within the control piston 12, connecting the pilot control chamber 14 to the oil drain chamber 15. A pilot return oil damper 23 is installed in this channel; both the pilot inlet damper 24 and the pilot return oil damper 23 serve as pressure dividers.

[0039] In the entire structure, the main valve core 2 is coaxial with the inner hole of the main valve sleeve 3, the pilot valve core 9 is coaxial with the inner hole of the pilot valve sleeve 8, the main valve core 2 and the pilot valve core 9 are coaxially arranged in opposite directions, and the small-diameter end of the control piston 12 is coaxially arranged opposite to the small-diameter end of the pilot valve core 9.

[0040] The dampers installed in the valve (including: the overcompensation damper 18 installed in the internal through hole of the pilot valve core 7, the pilot return oil damper 23 installed in the internal channel of the control piston 12, and the pilot inlet damper 24 installed in the channel connected to the control port X) are actually a sleeve structure with a small central through hole, which are screwed into the channel through threads.

[0041] In specific implementation, port A of the high-flow balancing valve is connected to port A of the reversing valve, port B is connected to the rodless chamber of the cylinder, port X is connected to the pressurized oil, and port L is connected to the oil tank. This high-flow balancing valve has three operating states: load hold, load increase, and load decrease. In each operating state, the specific operating conditions of each component of the high-flow balancing valve are as follows:

[0042] Load holding: The pressure oil at the load port B is high pressure, and there is no pressure oil input at ports A and X. Correspondingly, the load chamber 21 is a high pressure chamber, and the pilot control chamber 14 does not have high pressure oil. The control piston 12 remains in place under the action of the pilot control spring 11. The pilot valve core 7 is pressed to the right by the feedback spring 4 to form a conical seal, keeping the pilot valve port closed. The main valve core 2 is kept pressed to the left by the feedback spring 4 to form a conical seal. At this time, there is no conduction between the load port B, oil port A and oil port L.

[0043] Load increases: The pressure oil at port A is high pressure, correspondingly, the back-pressure chamber 22 is a high-pressure chamber. Ports B and X are deprived of pressure oil, and accordingly, the pilot control chamber 14 is free of high-pressure oil. The control piston 12 remains stationary under the action of the pilot control spring 11, compressing the control end cap 13. The pilot valve core 7 is pressed rightward by the feedback spring 4, forming a conical seal and keeping the pilot valve port closed. The high-pressure oil in the back-pressure chamber 22 acts on the left end of the main valve core 2, overcoming the force of the feedback spring 4 and pushing the main valve core 2 rightward. This opens the main valve port to a certain degree, establishing communication between ports A and B. The damping tail structure at the left end of the main valve core 2 effectively offsets the effects of the hydraulic forces acting on the main valve core 2, effectively improving the stability of the main valve core 2 during opening.

[0044] Load lowering: Figure 7As shown, pressure is input to pilot control port X. High-pressure oil enters pilot control chamber 14 from port X through pilot inlet damper 24, pushing control piston 12 leftward, overcoming the preload of pilot control spring 11. This causes oil in drain chamber 15 to flow out of port L, maintaining a low pressure in relief chamber 15. As control piston 12 moves leftward, overcoming the preload of pilot control spring 11, it travels a clearance distance (0.5 mm in this embodiment) before contacting the axial end of pilot valve core 7, pushing pilot valve core 7 leftward and opening the pilot valve port. At the same time, the pressure at the load port B is high-pressure oil. When the pilot valve port on the pilot valve core 7 is opened, the high-pressure oil in the load chamber 21 flows into the feedback chamber 20 through the throttle groove provided on the main valve core 2. The oil in the feedback chamber 20 flows into the transition chamber 17 through the channel inside the pilot valve core 7. The oil in the transition chamber 17 flows into the pilot oil return channel 16 through the pilot valve port on the pilot valve core 7. At this time, the pressure in the feedback chamber 20 begins to drop, and due to the action of the throttle groove on the main valve core 2, there is a pressure difference between the load chamber 21 and the feedback chamber 20. When the pressure in the feedback chamber 20 and the combined force of the feedback spring 4 are less than the pressure in the load chamber 21, the main valve core 2 is pushed to move to the right, the main valve port is opened, and the B port and the A port are connected. When the pilot valve core 7 moves to the left, the cylindrical surface of the large diameter end of the pilot valve core 7 covers the quick closing chamber 19, and there is no step gap between the pilot valve sleeve 6 and the pilot valve core 7. The feedback chamber 20 is not connected to the quick closing chamber 19, forming a closed cavity, maintaining the conduction state from port B to port A, executing the overtaking load lowering action, and the opening of the main valve port is controlled by the pressure of the control port X. The higher the control pressure, the larger the opening of the main valve port, thereby realizing the adjustment of the lowering speed.

[0045] An overcompensating damper 18 is installed in the internal hole of the pilot valve core 7. When the high-pressure oil at the load port B returns to the oil port L through the load chamber 21, the feedback chamber 20, the transition chamber 17, the pilot return oil channel 16, and the oil drain chamber 15, there will be a certain pressure difference when the oil passes through the overcompensating damper 18. The pressure in the feedback chamber 20 is greater than the pressure in the transition chamber 17. The combined force of the two acting on the pilot valve core 7 is the closing direction of the pilot valve core 7. If the pressure of the high-pressure oil entering the load port B is greater and the flow rate passing through is greater, the combined force driving the pilot valve core 7 to close will be greater. Therefore, when the load of the traditional large-flow balancing valve increases to a certain value, the main flow rate tends to decrease.

[0046] The present invention adds an adjusting stud 9 between the pilot oil return passage 16 and the axial flow passage 5. When the flow cross-section of the regulating mechanism valve port 10 in the adjusting stud 9 is the same diameter as the axial flow passage 5 in the pilot valve body 8, the oil passing through the adjusting stud 9 does not generate a significant pressure differential. The throttle groove at the rear end of the main valve core 2 determines the pressure differential between the load chamber 21 and the transition chamber 17, while the overcompensating damper 18 within the pilot valve core 7 determines the pressure differential between the feedback chamber 20 and the transition chamber 17, thus maintaining the original static characteristics. When the adjusting stud 9 is rotated to position the flow cross-section of the regulating mechanism valve port 10 smaller than the diameter of the axial flow passage 5 in the pilot valve body 8, an edge-shaped resistance is formed at the point where the flow area changes. When the oil passes through the adjusting stud 9, a pressure differential is generated between the backpressure chamber 22 and the pilot oil return passage 16. This differential acts on the main valve core 2, forcing it to close, thereby adjusting the flow rate of the balancing valve. Compared with the case before the adjustment stud 9 is installed, under the same control pressure X and load force, the pressure difference generated by the valve port 10 of the adjustment mechanism increases, the force acting on the closing direction of the main valve core 2 increases, and the flow rate of the main valve port decreases, further affecting the early inflection point of overcompensation and the increase of overcompensation amount, which is beneficial to the flow control of the large flow balancing valve. In summary, by adjusting the diameter of the flow cross section of the valve port 10 of the adjustment mechanism of the adjustment stud 9 (i.e. Figure 6 y) in the figure, the flow rate of the large flow balancing valve can be adjusted, and at the same time, the compensation amount and the over-compensation inflection point in the over-compensation characteristic can be adjusted.

[0047] This embodiment is simulated and analyzed, and the high flow balancing valve with flow regulator of the present invention and the existing balancing valve without flow regulator are simulated and verified under the same conditions. Figure 8 As shown, the control pressure of the large flow balancing valve is adjusted within the range of 0-20 bar, the load pressure is 150 bar, the flow cross-sectional diameter y of the regulating mechanism valve port 10 is adjusted, and the flow through the main valve core 2 is measured to obtain the control characteristic comparison curve of the regulating stud 9 under different flow cross-sectional diameters. Figure 8 It can be seen that the smaller the diameter y of the flow section, the smaller the main flow of the large flow balancing valve, and the smaller the control pressure value required to reach the saturated flow. This verifies that the flow regulator has a flow regulation effect on the large flow balancing valve when the load is reduced, and has no negative impact on the overall performance of the large flow balancing valve, ensuring the safety of the lowering action.

[0048] The large flow balancing valve with a flow regulator proposed in the present invention can adjust the flow characteristics of the balancing valve according to the flow requirements under different working conditions, and has important engineering significance.

[0049] Those skilled in the art will understand that the foregoing descriptions are merely preferred embodiments 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 will still be able to modify the technical solutions described in the foregoing examples or substitute equivalents for some of the technical features therein. Any modifications, equivalent substitutions, etc. made within the spirit and principles of the invention shall be included within the scope of protection of the invention.

Claims

1. A large flow balancing valve with a flow regulator, characterized in that: The main valve body comprises a main valve body, a pilot valve body, and a control end cover, which are arranged in sequence axially from front to back. An axial cavity is provided inside the main valve body and the pilot valve body and is interconnected. The main valve sleeve is arranged in the cavity inside the main valve body. An annular groove is provided on the inner wall corresponding to the middle of the main valve body and the main valve sleeve, forming a load cavity between the main valve body and the main valve sleeve. A load port B is provided on the main valve body to connect the outside with the load cavity. A plurality of radial through holes are provided in the middle of the main valve sleeve to connect the load cavity with the internal cavity of the main valve sleeve. The front end of the pilot valve sleeve is arranged in the cavity of the main valve body and is coaxially and tightly attached to the main valve sleeve, and the rear end thereof is arranged in the front part of the cavity inside the pilot valve body. The main valve core is coaxially slidably arranged in the cavity inside the main valve sleeve, and the pilot valve core is coaxially slidably arranged in the cavity inside the pilot valve sleeve; the main valve core and the pilot valve core are coaxially arranged in opposite directions, and the large diameter end of the main valve core is opposite to the large diameter end of the pilot valve core, and a feedback cavity is formed among the main valve core, the pilot valve core, the main valve sleeve and the pilot valve sleeve. A throttling groove is provided on the main valve core to connect the load cavity with the feedback cavity; one end of the feedback spring is against the large diameter end of the main valve core, and the other end is against the large diameter end of the pilot valve core; the small diameter end of the main valve core is against the main valve body The cavity between the two is the back pressure cavity, and the oil port A is provided on the main valve body to connect the outside with the back pressure cavity; in the initial state of the balancing valve, the main valve core is located at the front end of the axial limit and forms a conical surface seal between the main valve sleeve, the main valve port is closed, and the pilot valve core is located at the rear end of the axial limit and forms a conical surface seal between the pilot valve sleeve, and the pilot valve port is closed; a transition cavity is formed between the small diameter end of the pilot valve core and the cavity inside the pilot valve sleeve, and a coaxial channel is provided inside the pilot valve core to connect with the transition cavity, and an over-compensation damper is installed in the channel; A channel is provided in the pilot valve sleeve and the main valve body, so that when the pilot valve port is closed, the load port B is connected to the feedback chamber; a pilot oil return channel is formed between the rear end of the pilot valve sleeve and the pilot valve body, and when the pilot valve port is opened, the pilot oil return channel is connected to the transition chamber, and the load port B is not connected to the feedback chamber; the adjusting stud is installed in a mounting hole provided on the side wall of the pilot valve body and connected to the pilot oil return channel, and its axial mounting depth is adjustable within a certain range; an annular groove is provided on the outer wall of the adjusting stud, a blind hole is provided coaxially at the mounting end, and a cylindrical small hole is provided inside to connect the annular groove and the blind hole; an axial flow channel is provided inside the main valve body to connect the back pressure chamber and the annular groove on the adjusting stud, and the connecting port between the adjusting stud and the axial flow channel is the valve port of the adjusting mechanism, and its flow cross-section changes with the adjustment of the mounting depth of the adjusting stud; The control piston is coaxially arranged at the rear part of the cavity in the pilot valve body. Under the action of the pilot control spring, the disc of the control piston is in contact with the control end cover and a pilot control cavity is left between the two. The small-diameter end of the pilot valve core passes through the pilot valve sleeve and is installed opposite to the shaft of the control piston. The cavity between the control piston and the pilot valve body is the oil drain cavity. The pilot valve body is provided with an oil port L to connect the outside world with the oil drain cavity. The control end cover is provided with an X port to connect the outside world with the pilot control cavity, and a damper is arranged in the channel. The pilot control cavity and the oil drain cavity are connected through a channel provided in the control piston, and a damper is arranged in the channel.

2. The large flow balancing valve with flow regulator according to claim 1, characterized in that: The main valve core comprises, from front to back, a coaxial damping tail structure, a tapered section, and a cylindrical section. The main valve port of the pilot large-flow balancing valve is formed between the connection between the cylindrical section and the tapered section and the main valve sleeve. In the initial state of the balancing valve, the main valve core is located at the front end of the axial limit, and a conical surface seal is formed between the connection between the cylindrical section and the tapered section and the main valve sleeve. The main valve port is closed, and the back pressure chamber and the load chamber are not connected. When the main valve core moves backward, the main valve port is opened, and the back pressure chamber and the load chamber are connected. The throttling groove is symmetrically arranged at the tail end of the outer circumference of the cylindrical section of the main valve core. The throttling groove includes a U-shaped groove and a feedback throttling groove arranged in sequence from front to back and connected to each other, and the depth and width of the feedback throttling groove are both smaller than the U-shaped groove. The throttling groove is used to connect the load chamber and the feedback chamber, and the end surface where the throttling groove is connected to the feedback chamber forms a feedback valve port.

3. The large flow balancing valve with a flow regulator according to claim 1, characterized in that: A first stepped through hole is axially provided inside the pilot valve body, and the first stepped through hole comprises, from front to back, a first cylindrical hole, a second cylindrical hole, a third cylindrical hole, and a fourth cylindrical hole; The rear end of the pilot valve sleeve is installed in the first cylindrical hole. The first cylindrical hole is used to limit the pilot valve sleeve axially and radially. The inner diameter of the first cylindrical hole is the same as the outer diameter of the pilot valve sleeve, and the pilot valve sleeve and the first cylindrical hole are sealed by a sealing ring. The inner diameter of the second cylindrical hole is adapted to the outer diameter of the small diameter end of the pilot valve core extending out of the outside of the pilot valve sleeve; an annular partition is coaxially fixedly connected to the position connected to the second cylindrical through hole in the third cylindrical hole, and a through hole adapted to the outer diameter of the shaft of the control piston is opened on the annular partition; the shaft of the control piston and the small diameter end of the pilot valve core are coaxially mounted opposite each other in the through hole inside the annular partition, and a gap is left between the shaft of the control piston and the small diameter end of the pilot valve core in the initial state of the balancing valve; the pilot control spring is installed between the disk of the control piston and the annular partition, one end of which rests against the front end of the third cylindrical hole, and the other end rests against the control piston; and the inner diameter of the third cylindrical hole is adapted to the outer diameter of the pilot control spring; the inner diameter of the fourth cylindrical hole is adapted to the outer diameter of the disk of the control piston.

4. The large flow balancing valve with a flow regulator according to claim 1, characterized in that: Sealing is achieved between the main valve body and the pilot valve body, between the main valve sleeve and the main valve body, between the pilot valve sleeve and the main valve body, between the pilot valve sleeve and the pilot valve body, and between the main valve sleeve and the pilot valve sleeve by sealing rings.

5. The large flow balancing valve with a flow regulator according to claim 1, characterized in that: The overcompensation damper, the damper arranged in the channel between the X port and the pilot control chamber, and the damper arranged in the channel between the pilot control chamber and the oil drain chamber are all sleeve structures with a small through hole opened in the axis, and are installed in each channel by threaded rotation.

6. The large flow balancing valve with a flow regulator according to claim 1, characterized in that: A pilot oil return channel is formed between the rear end of the pilot valve sleeve and the pilot valve body. Specifically, a cylindrical hole is radially opened inside the pilot valve body along the contact surface of the pilot valve body and the pilot valve sleeve that is perpendicular to the axis, so that a cavity is formed between the pilot valve body and the pilot valve sleeve, which is recorded as the pilot oil return channel.

7. The large flow balancing valve with a flow regulator according to claim 1, characterized in that: A channel is provided in the pilot valve sleeve and the main valve body so that when the pilot valve port is closed, the load port B is connected with the feedback chamber. Specifically, an annular groove is provided on the outer wall of the middle portion of the pilot valve sleeve as a quick-closing chamber, and symmetrically distributed radial through holes are provided along the annular groove to connect the quick-closing chamber with the internal cavity of the pilot valve body. A channel is provided inside the main valve body to connect the quick-closing chamber with the load port B; and when the pilot valve port is closed, the quick-closing chamber is connected with the feedback chamber. When the pilot valve port is opened, the channel between the quick-closing chamber and the feedback chamber is covered, and the quick-closing chamber and the feedback chamber are not connected.

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