Pilot damping variable structure of balance valve

Abstract

The invention discloses a pilot damping variable structure of a balance valve, which relates to a valve component for a hydraulic device and comprises a pilot valve body, a pilot valve cavity is arranged in the pilot valve body, and an adjustable pilot damping valve core capable of reciprocating is mounted in the pilot valve cavity. The pilot valve body is further provided with a pressure adjusting assembly capable of adjusting the pressure needed by vertical movement of the pilot damping valve element. The pilot valve cavity is matched with the adjustable pilot damping valve element to form an upper cavity and a lower cavity which are independent of each other, a throttling groove capable of communicating the upper cavity with the lower cavity is formed in the adjustable pilot damping valve element, and an independent containing cavity is formed between the cavity bottom of the lower cavity and the lower end face of the adjustable pilot damping valve element. The containing cavity is communicated with the lower cavity. According to the invention, the pilot damping value can be changed along with the pressure change of the X port, so that the rapidity under low pilot pressure and the stability under high pilot pressure can be improved.

Description

Technical Field

[0001] The invention relates to a valve assembly for a hydraulic device, in particular to a variable pilot damping structure of a balancing valve. Background Art

[0002] Pilot-operated balancing valves have the advantages of high rated working pressure, reliable closure, controllable flow, and low energy consumption. They are widely used in situations where the working parts move vertically, such as excavators, lifting machinery, missile launchers, and other fields. In order to reduce overshoot and oscillation during the operation of the hydraulic system where the pilot-operated balancing valve is located, and to improve the stability of the hydraulic system where the pilot-operated balancing valve is located, one or two sections of fixed damping are usually provided in the pilot oil circuit of the pilot-operated balancing valve. Since the damping for throttling in the pilot oil circuit is a fixed throttle port, the pilot damping can only be switched between fixed values ​​when the main flow is controlled by the pilot pressure, and the pilot damping value cannot be smoothly adjusted according to the pilot pressure, resulting in the problem that the pilot chamber pressure rises slowly when the pilot pressure is low, and the pilot chamber pressure stability is poor when the pilot pressure is high. In addition, the existing pilot structure damping is fixed damping, which is matched by installing 1-4 fixed dampings in the pilot end cover. When the working conditions change, the pilot end cover and the fixed damping components need to be installed and removed. It is difficult to adapt to the working environment that requires multiple damping ratios to switch working conditions, and the adjustment operation is cumbersome.

[0003] In order to solve the technical problem that the pilot-operated balancing valve cannot smoothly adjust the pilot damping value according to the pilot pressure, resulting in a slow rise in the pilot chamber pressure when the pilot pressure is low and poor stability of the pilot chamber pressure when the pilot pressure is high, a pilot structure of a pilot damping variable balancing valve is urgently needed. Summary of the invention

[0004] The purpose of the present invention is to provide a variable pilot damping structure for a balancing valve, which controls the pilot damping value by means of the pilot port pressure, thereby accelerating the rapidity under low pilot pressure and the stability under high pilot pressure, so that the balancing valve can be applied to multiple working conditions without the need for an additional pilot valve block, thereby solving the problem of adapting to working conditions that require a variety of damping ratios and reducing the number of assembly and disassembly operations.

[0005] In order to achieve the purpose of the present invention, the technical scheme adopted is: a variable pilot damping structure of a balancing valve, including a pilot valve body, a pilot valve cavity is provided in the pilot valve body, an adjustable pilot damping valve core that can move back and forth is installed in the pilot valve cavity, and a pressure regulating component for the pressure required for the up and down movement of the adjustable pilot damping valve core is also installed on the pilot valve body; the pilot valve cavity and the adjustable pilot damping valve core form an upper chamber and a lower chamber that are independent of each other after cooperation, a throttling groove that can connect the upper chamber and the lower chamber is provided on the adjustable pilot damping valve core, and an independent accommodating chamber is formed between the bottom of the lower chamber and the lower end surface of the adjustable pilot damping valve core, and the accommodating chamber is connected to the lower chamber; the pilot valve body is also provided with a connecting hole connected to the upper chamber and a pilot oil inlet hole connected to the lower chamber.

[0006] Furthermore, the upper chamber and the lower chamber are both grooves provided in the valve cavity of the pilot valve, and the inner diameter of the upper chamber and the inner diameter of the lower chamber are both larger than the diameter of the adjustable pilot damping valve core.

[0007] Furthermore, a sealing ring is sleeved on the upper end of the adjustable pilot damping valve core, and the sealing ring is slidably sealed with the cavity wall of the valve cavity of the pilot valve.

[0008] Furthermore, the adjustable pilot damping valve core is in the shape of an I, and the middle portion of the adjustable pilot damping valve core corresponds to the upper chamber.

[0009] Furthermore, there is a transition chamber between the lower chamber and the upper chamber, the transition chamber cooperates with the lower end of the adjustable pilot damping valve core, and the throttling groove is located on the outer wall of the adjustable pilot damping valve core. The length of the throttling groove is greater than the length of the transition chamber, and the upper end of the throttling groove passes through the lower end face of the adjustable pilot damping valve core.

[0010] Furthermore, there are multiple throttling grooves, and the multiple throttling grooves are evenly spaced along the circumferential direction of the adjustable pilot damping valve core.

[0011] Furthermore, the accommodating cavity is a groove formed at the bottom of the lower chamber, and a flow channel connecting the accommodating cavity and the lower chamber is formed on the adjustable pilot damping valve core.

[0012] Furthermore, the flow channel includes a radial through hole radially penetrating the side wall of the adjustable pilot damping valve core, an axial through hole axially penetrating the lower end surface of the pilot damping valve core, and the axial through hole is connected to the radial through hole.

[0013] Furthermore, there are a plurality of radial through holes, and the plurality of radial through holes are evenly spaced apart along the circumferential direction of the adjustable pilot damping valve core.

[0014] Furthermore, the pressure regulating assembly includes an adjusting spring sleeve installed on the valve body of the pilot valve, an adjusting bolt is installed in the adjusting spring sleeve, and a return spring is connected between the adjusting bolt and the adjustable pilot damping valve core.

[0015] Furthermore, the adjusting spring sleeve and the adjusting bolt are both threadedly mounted.

[0016] Furthermore, it also includes a main valve body fixed to the pilot valve body, the main valve body having a main valve cavity connected to the connecting hole, and a control piston that can reciprocate is installed in the main valve cavity, and a first control spring and a second control spring are arranged between the control piston and the cavity wall of the main valve cavity; the main valve body is also provided with an X port connected to the pilot oil inlet hole.

[0017] The beneficial effects of the present invention are:

[0018] In the present invention, the throttling groove and the accommodating chamber cooperate with each other so that the opening of the throttling groove on the adjustable pilot damping valve core can be affected by the pressure of the hydraulic oil entering the lower chamber, thereby realizing the control of the pilot damping value by the pilot port pressure, accelerating the rapidity under low pilot pressure and the stability under high pilot pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings illustrate exemplary embodiments of the present invention and together with the description serve to explain the principles of the present invention. These drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of this specification.

[0020] Figure 1 It is a structural diagram of the variable pilot damping structure of the balancing valve provided by the present invention;

[0021] Figure 2 It is a structural diagram of the adjustable pilot damping valve core.

[0022] Markings and corresponding parts names in the attached drawings:

[0023] 1. Pilot valve body, 2. Pilot valve cavity, 3. Adjustable pilot damping valve core, 4. Pressure regulating assembly, 5. Connecting hole, 6. Pilot oil inlet hole, 7. Sealing ring, 8. Main valve body, 9. Main valve cavity, 10. Control piston, 11. First control spring, 12. Second control spring, 13. X port;

[0024] 21. upper chamber, 22. lower chamber, 23. transition chamber, 24. receiving chamber;

[0025] 31. throttle groove, 32. radial through hole, 33. axial through hole;

[0026] 41. Adjusting spring sleeve, 42. Adjusting bolt, 43. Return spring. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below in conjunction with the accompanying drawings and implementation methods. It is understood that the specific implementation methods described herein are only used to explain the relevant content, rather than to limit the present invention. It is also necessary to explain that, for ease of description, only the parts related to the present invention are shown in the accompanying drawings.

[0028] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0029] like Figure 1 As shown, a variable pilot damping structure of a balancing valve provided by the present invention comprises a pilot valve body 1, wherein the pilot valve body 1 has a pilot valve cavity 3, wherein an adjustable pilot damping valve core 3 is installed in the pilot valve cavity 3, and the adjustable pilot damping valve core 3 can reciprocate in the pilot valve cavity 3. A pressure regulating assembly 4 is also installed on the pilot valve body 1, wherein the pressure regulating assembly 4 is located above the adjustable pilot damping valve core 3, and the pressure regulating assembly 4 cooperates with the adjustable pilot damping valve core 3 and provides a thrust for the adjustable pilot damping valve core 3; when the pressure of the hydraulic oil applied to the adjustable pilot damping valve core 3 is less than the thrust applied by the pressure regulating assembly 4, the adjustable pilot damping valve core 3 does not move in the pilot valve cavity 3; when the pressure of the hydraulic oil applied to the adjustable pilot damping valve core 3 is greater than the thrust applied by the pressure regulating assembly 4, the adjustable pilot damping valve core 3 moves toward the pressure regulating assembly 4 in the pilot valve cavity 3.

[0030] In order to facilitate the coordination between the pressure regulating component 4 and the adjustable pilot damping valve core 3, the pressure regulating component 4 can also be installed in the pilot valve cavity 3, but it is necessary to ensure that the adjustable pilot damping valve core 3 can reciprocate in the pilot valve cavity 3 after the pressure regulating component 4; of course, when the depth of the pilot valve cavity 3 cannot simultaneously meet the installation of the pressure regulating component 4 and the adjustable pilot damping valve core 3, and does not affect the pressure regulating component 4 providing thrust for the adjustable pilot damping valve core 3, the pressure regulating component 4 can also be installed on the end face of the pilot valve body 1 by using a mounting seat, and the adjustable pilot damping valve core 3 can be installed in the pilot valve cavity 3, but the sealing of the pilot valve cavity 3 must be ensured.

[0031] After the adjustable pilot damping valve core 3 is installed in the pilot valve cavity 3, the outer wall of the adjustable pilot damping valve core 3 cooperates with the cavity wall of the pilot valve cavity 3 to form two independent chambers, the two chambers are an upper chamber 21 and a lower chamber 22, the upper chamber 21 and the lower chamber 22 are arranged at intervals along the axial direction of the pilot valve cavity 3, and a throttling groove 31 is also provided on the adjustable pilot damping valve core 3, the throttling groove 31 extends along the axial direction of the adjustable pilot damping valve core 3, and the two ends of the throttling groove 31 are respectively connected to the upper chamber 21 and the lower chamber 22.

[0032] In order to ensure that the adjustable pilot damping valve core 3 can be pushed to move toward the pressure regulating assembly 4 when the pressure of the hydraulic oil in the lower chamber 22 increases, an independent accommodating chamber 24 is formed between the bottom of the lower chamber 22 and the lower end surface of the adjustable pilot damping valve core 3, and the accommodating chamber 24 is connected to the lower chamber 22, so that the hydraulic oil entering the lower chamber 22 can enter the accommodating chamber 24 at the same time. When the pressure of the hydraulic oil in the lower chamber 22 and the accommodating chamber 24 increases to a level greater than the thrust applied by the pressure regulating assembly 4, the pressure of the hydraulic oil acts on the end surface of the adjustable pilot damping valve core 3, thereby pushing the adjustable pilot damping valve core 3 toward the pressure regulating assembly 4. When the pressure of the hydraulic oil in the lower chamber 22 and the accommodating chamber 24 is equal to or less than the thrust applied by the pressure regulating assembly 4, the thrust of the pressure regulating assembly 4 pushes the adjustable pilot damping valve core 3 to reset.

[0033] The pilot valve body 1 is also provided with a connecting hole 5 and a pilot oil inlet hole 6. The two ends of the connecting hole 5 are respectively connected to the main valve and the upper chamber 21, and the two ends of the pilot oil inlet hole 6 are respectively connected to the lower chamber 22 and the X port 13 on the main valve.

[0034] In order to form the upper chamber 21 and the lower chamber 22, the upper chamber 21 and the lower chamber 22 are both grooves opened in the pilot valve cavity 3, that is, the pilot valve cavity 3 is not a straight cylinder, and the pilot valve cavity 3 is composed of multiple sections of channels with different inner diameters, wherein the inner diameters of the upper chamber 21 and the lower chamber 22 are both larger than the diameter of the adjustable pilot damping valve core 3. When the adjustable pilot damping valve core 3 is installed in the pilot valve cavity 3, two independent chambers are formed between the cavity wall of the upper chamber 21 and the outer wall of the adjustable pilot damping valve core 3, and between the cavity wall of the lower chamber 22 and the outer wall of the adjustable pilot damping valve core 3. The two independent chambers are the upper chamber 21 and the lower chamber 22, and the outer wall of the adjustable pilot damping valve core 3 and the other parts of the cavity wall of the pilot valve cavity 3 are matched with a sliding clearance.

[0035] In order to prevent the hydraulic oil entering the upper chamber 21 from directly entering between the adjustable pilot damping valve core 3 and the wall of the pilot valve chamber 3 and into between the adjustable pilot damping valve core 3 and the pressure regulating assembly 4, a sealing ring 7 is also provided on the upper end of the adjustable pilot damping valve core 3, so that after the adjustable pilot damping valve core 3 is installed in the pilot valve chamber 3, the upper end of the adjustable pilot damping valve core 3 is slidably sealed with the wall of the pilot valve chamber 3 through the sealing ring 7, effectively preventing the hydraulic oil entering the upper chamber 21 from entering between the adjustable pilot damping valve core 3 and the pressure regulating assembly 4, thereby avoiding affecting the movement of the adjustable pilot damping valve core 3 in the pilot valve chamber 3, so that the thrust to be overcome when the adjustable pilot damping valve core 3 moves remains fixed.

[0036] In addition, in order to make the capacity of the upper chamber 21 larger, the pilot damping valve core 3 can be adjusted during design, such as Figure 2 As shown, the shape of the adjustable pilot damping valve core 3 can be set to an "I" shape, that is, the adjustable pilot damping valve core 3 is large at both ends and small in the middle. At this time, the middle section of the adjustable pilot damping valve core 3 corresponds to the upper chamber 21, and the length of the middle section of the adjustable pilot damping valve core 3 is equal to the length of the upper chamber 21. When the pressure of the hydraulic oil on the adjustable pilot damping valve core 3 is less than the thrust applied by the pressure adjustable component, the two ends of the adjustable pilot damping valve core 3 are flush with the two ends of the upper chamber 21.

[0037] Since the upper chamber 21 and the lower chamber 22 are two independent chambers, and there is a certain distance between the upper chamber 21 and the lower chamber 22, the pilot valve chamber 3 has a transition chamber 23 connecting the upper chamber 21 and the lower chamber 22, and the cavity wall of the transition chamber 23 is matched with the outer wall of the adjustable pilot damping valve core 3; in order to adjust the flow rate of hydraulic oil from the lower chamber 22 into the upper chamber 21, the regulating valve spool 3 is adjusted. The flow groove 31 is arranged on the circumferential surface of the adjustable pilot damping valve core 3, and when selecting the length of the throttling groove 31, the length of the throttling groove 31 should be greater than the length of the transition chamber 23, but the length of the throttling groove 31 is less than the length of the lower section of the adjustable pilot damping valve core 3, that is, the end of the throttling groove 31 communicating with the lower chamber 22 terminates at the middle of the lower section of the adjustable pilot damping valve core 3, or the end of the throttling groove 31 communicating with the lower chamber 22 terminates at the upper part of the lower section of the adjustable pilot damping valve core 3. When the pressure of the hydraulic oil applied to the adjustable pilot damping valve core 3 is less than the thrust applied by the pressure regulating assembly 4, one end of the throttling groove 31 penetrates the end surface of the lower section of the adjustable pilot damping valve core 3 and is flush with the wall of the upper chamber 21, and the other end of the throttling groove 31 continues to extend after exceeding the wall of the lower chamber 22. When the pressure of the hydraulic oil in the lower chamber 22 and the accommodating chamber 24 applied to the adjustable pilot damping valve core 3 is less than the thrust applied by the pressure regulating assembly 4, the portion of the inlet 13 end of the throttling groove 31 located in the lower chamber 22 is the largest, and the opening of the inlet 13 end of the throttling groove 31 is the largest; as the adjustable pilot damping valve core 3 gradually moves toward the pressure regulating assembly 4, the portion of the inlet 13 end of the throttling groove 31 located in the lower chamber 22 gradually decreases, and the opening of the inlet 13 end of the throttling groove 31 gradually decreases.

[0038] In the present invention, the throttling grooves 31 on the adjustable pilot damping valve can be multiple, for example, three, four, etc., and the multiple throttling grooves 31 are evenly spaced along the circumferential direction of the adjustable pilot damping valve core 3. In the present invention, the specific number of throttling grooves 31 can be selected according to actual conditions.

[0039] In order to facilitate the setting of the accommodating chamber 24, a groove can be directly opened at the bottom of the lower chamber 22. When the pressure of the hydraulic oil on the adjustable pilot damping valve is less than the thrust applied by the pressure regulating assembly 4, and the adjustable pilot damping valve core 3 is pressed against the bottom of the pilot valve chamber 3, the adjustable pilot damping valve core 3 closes the groove to form the accommodating chamber 24. In order to ensure the connection between the accommodating chamber 24 and the lower chamber 22, a channel connecting the accommodating chamber 24 and the lower chamber 22 is opened on the adjustable pilot damping valve core 3, so that the hydraulic oil can enter the lower chamber 22 through the channel while entering the lower chamber 22, so that the pressure of the hydraulic oil in the lower chamber 22 and the hydraulic oil in the accommodating chamber 24 are kept consistent.

[0040] Of course, in the present invention, the groove can also be directly opened on the lower end surface of the adjustable pilot damping valve core 3. When the adjustable pilot damping valve core 3 is pressed against the bottom of the pilot valve cavity 3, the groove on the adjustable pilot damping valve core 3 is closed by the bottom of the pilot valve cavity 3. At this time, an accommodating cavity 24 can also be formed; in addition, a convex ring can also be directly provided on the lower end surface of the adjustable pilot damping valve core 3 or the bottom of the pilot valve cavity 3. When the adjustable pilot damping valve core 3 is pressed against the bottom of the pilot valve cavity 3, the inner wall of the convex ring, the lower end surface of the adjustable pilot damping valve core 3 and the bottom of the pilot valve cavity 3 cooperate to form an accommodating cavity 24. Therefore, in the present invention, there are many ways to form the accommodating chamber 24. When the hydraulic oil pressure in the lower chamber 22 is greater than the thrust applied by the pressure regulating assembly 4, the hydraulic oil in the accommodating chamber 24 can push the adjustable pilot damping valve core 3 to move toward the pressure regulating assembly 4, and the structure forming the accommodating chamber 24 can be adjusted at will.

[0041] The flow channel of the present invention is designed as follows: Figure 2 As shown, the flow channel includes a radial through hole 32 and an axial through hole 33. The axial direction of the radial through hole 32 is consistent with the radial direction of the adjustable pilot damping valve core 3, and the axial direction of the axial through hole 33 is consistent with the axial direction of the adjustable pilot damping valve core 3. The position of the radial through hole 32 has a certain axial distance from the end of the throttling groove 31 connected to the lower chamber 22, so as to avoid the radial through hole 32 being closed when the adjustable pilot damping valve core 3 moves toward the pressure adjustable component; at the same time, one end of the radial through hole 32 passes through the outer cylindrical surface of the adjustable pilot damping valve core 3, and the other end of the radial through hole 32 is located at the center of the adjustable pilot damping valve core 3, and one end of the axial through hole 33 is connected to the radial through hole 32, and the other end of the axial through hole 33 passes through the lower end surface of the adjustable pilot damping valve core 3. Of course, under the condition that the lower chamber 22 is connected with the accommodating chamber 24, one end of the axial through hole 33 can pass through the outer cylindrical surface of the adjustable pilot damping valve core 3, and the other end of the axial through hole 33 can deviate from the center of the adjustable pilot damping valve core 3, and the axis of the axial through hole 33 can also form a certain angle with the axis of the adjustable pilot damping valve core 3.

[0042] In the present invention, the radial through holes 32 can be multiple, for example, two, three, four, etc. In this case, the multiple radial through holes 32 are evenly spaced along the circumferential direction of the adjustable pilot damping valve core 3, so that the hydraulic oil in the lower chamber 22 located at the periphery of the adjustable pilot damping valve core 3 can evenly enter the lower chamber 22 through the radial through holes 32 and the axial through holes 33. In addition, when the axial through holes 33 in the present invention are designed, in order to ensure that the hydraulic oil entering the multiple radial through holes 32 can smoothly enter the accommodating chamber 24 through the axial through holes 33, the diameter of the axial through holes 33 is greater than the diameter of the radial through holes 32.

[0043] The pressure regulating assembly 4 in the present invention comprises an adjusting spring sleeve 41, an adjusting bolt 42 and a reset spring 43. The adjusting spring sleeve 41 is installed in the opening X-port 13 of the pilot valve cavity 3 by means of threaded connection, and the adjusting spring sleeve has a through hole coaxially arranged with the adjustable pilot damping valve core 3. The adjusting bolt 42 is installed in the through hole of the adjusting spring sleeve by means of threaded connection, and the reset spring 43 is installed between the adjusting bolt and the adjustable pilot damping valve core 3. In the present invention, since the adjusting spring sleeve and the adjusting bolt are both installed by means of threaded connection, the adjusting spring sleeve and the adjusting bolt can be adjusted along the axial direction of the adjustable pilot damping valve core 3, so that the spacing between the adjusting bolt and the adjustable pilot damping valve core 3 is adjusted, thereby adjusting the compression degree of the reset spring 43, so that the thrust of the adjustable pilot damping valve core 3 by the reset spring 43 is adjusted, and the pressure required for the adjustable pilot damping valve core 3 to compress the reset spring 43 is adjusted.

[0044] In the present invention, when the depth of the pilot valve cavity 3 can only meet the movement of the adjustable pilot damping valve core 3, the adjusting spring sleeve 41 can be directly fixed to the outer wall of the pilot valve body 1 by screws, and then the adjusting bolt is installed in the adjusting spring sleeve 41 by threaded connection; or, a mounting seat can be fixedly installed on the outer wall of the pilot valve body 1, and then the adjusting spring sleeve 41 in the pressure regulating assembly 4 is installed on the mounting seat by threaded connection or screw fixing. That is, in the present invention, the specific installation position and installation method of the adjusting spring sleeve 41 can be adaptively adjusted while meeting the compression degree of the adjusting reset spring 43.

[0045] The variable pilot damping structure of the balancing valve provided by the present invention also includes a main valve body 8, which is fixed on the side wall of the pilot valve body 1; the main valve body 8 has a main valve cavity 9 connected to the connecting hole 5, and a control piston 10 that can reciprocate is installed in the main valve cavity 9. The control piston 10 is slidably sealed with the cavity wall of the main valve cavity 9, and a piston rod is installed on the side of the control piston 10 away from the connecting hole 5. The extended end of the piston rod is provided with a guide shaft that slides with the main valve body 8, and the piston rod is sleeved with a first control spring 11 and a second control spring 12, one end of the first control spring 11 and the second control spring 12 are pressed against the control piston 10, and the other end of the first control spring 11 and the second control spring 12 are pressed against the cavity wall of the main valve cavity 9; the main valve body 8 is also provided with an X port 13 that is connected to the pilot oil inlet hole 6.

[0046] In the present invention, the main valve body 8 also has a pilot valve core, and the guide shaft is connected to the pilot valve core. However, the design of the pilot valve core in the main valve body 8 in the present invention is prior art and is not an improvement of the present invention. Therefore, it will not be described in detail in the present invention.

[0047] In the present invention, in order to ensure the sealing between the main valve body 8 and the pilot valve body 1, a sealing ring is pressed between the main valve body 8 and the pilot valve body 1. Specifically, there are two sealing rings, one sealing ring 7 is arranged concentrically with the main valve cavity 9, and the other sealing ring 7 is arranged concentrically with the outlet X port 13 of the X port 13.

[0048] The working principle of the variable pilot damping structure of the balancing valve provided by the present invention is as follows:

[0049] When the hydraulic oil is not introduced into the X-port 13 and the hydraulic oil pressure value of the X-port 13 is low, the adjustable pilot damping valve core 3 is not subjected to the pressure of the hydraulic oil, so the adjustable pilot damping valve core 3 presses against the valve chamber 3 of the pilot valve.

[0050] When hydraulic oil is introduced into the X port 13, the hydraulic oil enters the lower chamber 22 through the pilot oil inlet hole 6. At this time, the hydraulic oil pressure in the lower chamber 22 is less than the elastic force of the return spring 43. The hydraulic oil in the lower chamber 22 enters the upper chamber 21 through the throttling groove 31. The hydraulic oil entering the upper chamber 21 enters the pilot chamber through the connecting hole 5, so that the pressure of the hydraulic oil in the pilot chamber increases, thereby pushing the control piston 10 to overcome the spring force of the first control spring 11 and the second control spring 12 to move to the right, thereby pushing the pilot valve core on the right side to open.

[0051] Since the hydraulic oil entering the lower chamber 22 through the pilot oil inlet hole 6 enters the upper chamber 21 through the throttling groove 31, the hydraulic oil in the chamber will also enter the accommodating chamber 24 through the radial through hole 32 and the axial hole, so that the hydraulic oil pressure of the accommodating chamber 24, the lower chamber 22, the pilot oil inlet hole 6, and the X-port 13 are kept consistent. At this time, the lower end of the adjustable pilot damping valve core 3 is subjected to the pressure of the hydraulic oil in the accommodating chamber 24, and the elastic force of the return spring 43 on the upper end of the adjustable pilot damping valve core 3 is balanced with the pressure of the hydraulic oil in the accommodating chamber 24 on the lower end of the adjustable pilot damping valve core 3. Since the sealing ring 7 installed on the upper section of the adjustable pilot damping valve core 3 isolates the hydraulic oil in the upper chamber 21 from entering between the adjustable pilot damping valve core 3 and the adjusting spring sleeve 41, the upper end surface of the adjustable pilot damping valve core 3 is not subjected to the pressure of the hydraulic oil, but is only subjected to the spring force from the return spring 43. When the adjustable pilot damping valve core 3 is in a balanced state, the force of the return spring 43 on the upper end of the adjustable pilot damping valve core 3 is balanced by the pressure of the hydraulic oil on the lower end of the adjustable pilot damping valve core 3.

[0052] As the pressure of the hydraulic oil at the X-port 13 continues to rise, the pressure of the hydraulic oil in the lower chamber 22 and the accommodating chamber 24 also continues to rise. When the hydraulic oil pressure in the accommodating chamber 24, the lower chamber 22, the pilot oil inlet hole 6, and the X-port 13 exceeds the spring force generated by the pre-compression of the return spring 43, the adjustable pilot damping valve core 3 can further produce an upward displacement, pushing the return spring 43 to gradually increase the compression amount, and gradually reduce the opening and flow area of ​​the end of the throttling groove 31 connected to the lower chamber 22, further increasing the pilot damping value of the balancing valve. When the hydraulic oil pressure in the accommodating chamber 24, the lower chamber 22, the pilot oil inlet hole 6, and the X-port 13 is large enough, the lower end of the throttling groove 31 enters the transition chamber 23, prompting the throttling groove 31 to close, and finally realizing the control of the pilot damping value by the pressure of the X-port 13, accelerating the rapidity under low pilot pressure and the stability under high pilot pressure.

[0053] At the same time, during use, since the adjustable pilot damping valve core 3 begins to displace and the pilot damping of the balancing valve begins to increase, this is caused by the hydraulic oil pressure in the X-port 13, the pilot oil inlet hole 6, the lower chamber 22, and the accommodating chamber 24 being greater than the elastic force of the reset spring 43 under the pre-compression amount. Therefore, the pre-compression amount of the reset spring 43 can be adjusted by adjusting the adjusting bolt 42, and then the X-port 13 pressure node value where the pilot damping begins to change can be adjusted, and the overall numerical correspondence between the pilot pressure and the pilot damping can be adjusted.

[0054] In the description of this specification, the description with reference to the terms "one embodiment / method", "some embodiments / methods", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment / method or example are included in at least one embodiment / method or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment / method or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments / methods or examples. In addition, those skilled in the art may combine and combine the different embodiments / methods or examples described in this specification and the features of the different embodiments / methods or examples, unless they are contradictory.

[0055] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0056] It should be understood by those skilled in the art that the above embodiments are only for the purpose of clearly illustrating the present invention, and are not intended to limit the scope of the present invention. For those skilled in the art, other changes or modifications may be made based on the above disclosure, and these changes or modifications are still within the scope of the present invention.

Claims

1. A variable pilot damping structure of a balancing valve, characterized in that: The invention comprises a pilot valve body (1), wherein the pilot valve body (1) has a pilot valve cavity (3), wherein an adjustable pilot damping valve core (3) capable of reciprocating movement is installed in the pilot valve cavity (3), and a pressure regulating assembly (4) for adjusting the pressure required for the upward and downward movement of the adjustable pilot damping valve core (3) is also installed on the pilot valve body (1); the pilot valve cavity (3) and the adjustable pilot damping valve core (3) cooperate to form an upper chamber (21) and a lower chamber (22) which are independent of each other, The adjustable pilot damping valve core (3) is provided with a throttling groove (31) which can connect the upper chamber (21) and the lower chamber (22), and an independent accommodating chamber (24) is formed between the chamber bottom of the lower chamber (22) and the lower end surface of the adjustable pilot damping valve core (3), and the accommodating chamber (24) is connected to the lower chamber (22); the pilot valve body (1) is also provided with a connecting hole (5) connected to the upper chamber (21) and a pilot oil inlet hole (6) connected to the lower chamber (22).

2. The variable pilot damping structure of the balancing valve according to claim 1 is characterized in that: The upper chamber (21) and the lower chamber (22) are both grooves formed in the valve cavity (3) of the pilot valve. The inner diameters of the upper chamber (21) and the lower chamber (22) are both larger than the diameter of the adjustable pilot damping valve core (3).

3. The variable pilot damping structure of the balancing valve according to claim 1 is characterized in that: The upper end of the adjustable pilot damping valve core (3) is sleeved with a sealing ring (7), and the sealing ring (7) is in sliding sealing cooperation with the cavity wall of the pilot valve cavity (3).

4. The variable pilot damping structure of the balancing valve according to claim 1 is characterized in that: The adjustable pilot damping valve core (3) is in the shape of an I, and the middle portion of the adjustable pilot damping valve core (3) corresponds to the upper chamber (21).

5. The variable pilot damping structure of the balancing valve according to claim 4 is characterized in that: A transition chamber (23) is provided between the lower chamber (22) and the upper chamber (21), the transition chamber (23) cooperates with the lower end of the adjustable pilot damping valve core (3), and a throttling groove (31) is located on the outer wall of the adjustable pilot damping valve core (3), the length of the throttling groove (31) is greater than the length of the transition chamber (23), and the upper end of the throttling groove (31) passes through the lower end surface of the adjustable pilot damping valve core (3).

6. The variable pilot damping structure of the balancing valve according to claim 5 is characterized in that: There are a plurality of throttling grooves (31), and the plurality of throttling grooves (31) are evenly spaced and arranged along the circumferential direction of the adjustable pilot damping valve core (3).

7. The variable pilot damping structure of the balancing valve according to claim 1 is characterized in that: The accommodating chamber (24) is a groove formed in the bottom of the lower chamber (22), and a flow channel connecting the accommodating chamber (24) and the lower chamber (22) is also formed on the adjustable pilot damping valve core (3).

8. The variable pilot damping structure of the balancing valve according to claim 7 is characterized in that: The flow channel comprises a radial through hole (32) radially penetrating the side wall of the adjustable pilot damping valve core (3), and an axial through hole (33) axially penetrating the lower end surface of the pilot damping valve core, and the axial through hole (33) is connected to the radial through hole (32).

9. The variable pilot damping structure of the balancing valve according to claim 8 is characterized in that: There are a plurality of radial through holes (32), and the plurality of radial through holes (32) are evenly spaced and arranged along the circumferential direction of the adjustable pilot damping valve core (3).

10. The variable pilot damping structure of the balancing valve according to claim 1, characterized in that: The pressure regulating assembly (4) comprises an adjusting spring sleeve (41) mounted on a pilot valve body (1), an adjusting bolt (42) being mounted in the adjusting spring sleeve (41), and a return spring (43) being connected between the adjusting bolt (42) and the adjustable pilot damping valve core (3).

11. The variable pilot damping structure of the balancing valve according to claim 10, characterized in that: The adjusting spring sleeve (41) and the adjusting bolt (42) are both threadedly mounted.

12. The variable pilot damping structure of a balancing valve according to any one of claims 1 to 11, characterized in that: It also includes a main valve body (8) fixed to the pilot valve body (1), the main valve body (8) having a main valve cavity (9) connected to the connecting hole (5), and a reciprocating control piston (10) installed in the main valve cavity (9), a first control spring (11) and a second control spring (12) provided between the control piston (10) and the cavity wall of the main valve cavity (9); the main valve body (8) is also provided with an X port (13) connected to the pilot oil inlet hole (6).

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