Pilot control valve, hydraulic control system, and working machine

Abstract

The invention discloses a pilot control valve, a hydraulic control system and an operation machine, a first valve cavity is formed in a valve body assembly, one end of the valve body assembly is used for being connected with a control valve, and a control port is formed in the end, facing the control valve, of the valve body assembly; the floating valve element is located in the first valve cavity and comprises a floating element body, one end of the floating element body is movably inserted into the assembly, and the other end of the floating element body can movably penetrate through the control port. The pressure dividing assembly comprises an elastic piece and a first damper, the elastic piece is elastically connected between the inner wall of the assembly and the floating core body, the first damper is inserted into the inner hole, and the end, away from the elastic piece, of the floating core body is used for abutting against the control piston; hydraulic oil flowing out of the control port is used for driving the control piston to move, and the elastic piece is used for driving the floating core body to move in the axial direction and changing the distance between the floating core body and the valve body assembly so as to adjust the hydraulic oil output flow of the control port. According to the pilot control valve, the response speed can be increased while the executing mechanism stably moves.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of working machines, and particularly relates to a pilot control valve, a hydraulic control system and a working machine. BACKGROUND

[0002] With the rapid development of working machines, users have higher and higher requirements for the responsiveness, stability and controllability of the actuator when operating the crane, especially when the crane is in the operation of "piling against piles", the micro-motion performance and stability performance of the hoist mechanism and luffing mechanism are particularly high. In order to ensure the stability of starting, the existing load holding valve generally has a damping network on the pilot control mechanism, which largely solves the problem of shaking. However, the damping network of the pilot mechanism is generally fixed damping. When the control pressure is input at the oil inlet, the output pressure of the oil outlet is difficult to guarantee after passing through the fixed damping, that is, the response speed of the actuator is relatively slow. If the damping is cancelled or increased, the actuator is prone to shaking, that is, the rapid response and stable operation of the actuator are contradictory, and cannot be satisfied at the same time, which directly affects the user's operation experience. SUMMARY

[0003] The purpose of the present application is to provide a pilot control valve, a hydraulic control system and a working machine, which realizes stable movement of the actuator while improving the response speed.

[0004] In order to achieve the above purpose, the present application provides a pilot control valve, comprising: a valve body assembly having a first valve cavity inside, one end of the valve body assembly being used for connecting with a control valve, and a control port being formed at one end of the valve body assembly facing the control valve; a floating spool located in the first valve cavity, the floating spool comprising a floating spool body, one end of the floating spool body being movably inserted into the valve body assembly, and the other end being movably penetrated from the control port; a pressure dividing assembly comprising an elastic member and a first damping, the elastic member being elastically connected between the inner wall of the valve body assembly and the floating spool body, and the first damping being inserted into the floating spool body, one end of the floating spool body away from the elastic member being in abutment with a control piston of the control valve; wherein the hydraulic oil flowing out of the control port is used to drive the control piston to move, and the elastic member is used to drive the floating spool body to move along the axial direction and change the oil passing area between the floating spool body and the valve body assembly, so as to adjust the output flow of the hydraulic oil of the control port.

[0005] In some embodiments, the valve body assembly comprises a valve body and a valve sleeve located in the first valve cavity, one end of the floating core body is movably inserted into the valve sleeve, the valve sleeve has a second valve cavity, the second valve cavity comprises a first cavity, a second cavity and a third cavity which are sequentially communicated along the axial direction, the elastic member is located in the second cavity and both ends of the elastic member are connected to the end surface of the second cavity and the floating core body respectively, and the floating core body is movably located in the third cavity.

[0006] In some embodiments, the first cavity is provided with a second damping, the second damping comprises a first end cover and a damping body connected to the first end cover, the first end cover is located at one end of the valve sleeve away from the floating core body and has an outer diameter greater than the inner diameter of the first cavity, and the damping body is located in the first cavity.

[0007] In some embodiments, the first valve cavity comprises a fourth cavity, a fifth cavity and a sixth cavity which are sequentially communicated along the axial direction and have sequentially decreasing inner diameters, the valve sleeve is located in the fourth cavity, the floating core body comprises a large diameter portion, a valve seat and a small diameter portion which are sequentially connected along the axial direction, the valve seat comprises a circular truncated cone portion and a circular ring portion, the outer diameter of the circular truncated cone portion decreases towards the direction away from the large diameter portion, the outer diameter of the circular ring portion is equal to the outer diameter of the end portion of the circular truncated cone portion and is smaller than the outer diameter of the small diameter portion, the large diameter portion is movably located in the fifth cavity, the maximum outer diameter of the circular truncated cone portion is smaller than the inner diameter of the fifth cavity and larger than the inner diameter of the sixth cavity, and the small diameter portion is movably located in the sixth cavity.

[0008] In some embodiments, an oil channel is formed in the outer periphery of the circular truncated cone portion, and the oil channel is communicated with the third cavity.

[0009] In some embodiments, the pilot control valve further comprises an oil inlet connector movably inserted into the first valve cavity, the oil inlet connector and one end of the valve sleeve away from the floating core body are arranged in a spaced manner, the oil inlet connector forms an oil inlet passage communicated with the first valve cavity, and the oil inlet connector is provided with a third damping.

[0010] In some embodiments, the valve body is further provided with a pressure dividing oil passage which is perpendicular to and communicated with the central axis of the first valve cavity, the pressure dividing oil passage is communicated with an external hydraulic oil tank through a pipeline, the pressure dividing oil passage is provided with a fourth damping and a blocking ball, the pressure dividing oil passage is used for dividing the hydraulic oil in the first valve cavity, and the blocking ball is used for connecting or blocking the communication between the pressure dividing oil passage and the first valve cavity oil passage.

[0011] In some embodiments, the pressure dividing oil passage comprises a first pressure dividing cavity, a second pressure dividing cavity and a third pressure dividing cavity connected in sequence and having inner diameters increasing in sequence, the third pressure dividing cavity is connected with the first valve cavity, and the blocking ball is located in the second pressure dividing cavity and has an outer diameter greater than the inner diameter of the first pressure dividing cavity; The fourth damping part is provided with a pressure dividing hole in the axial direction and comprises a first damping part, a second damping part and a third damping part connected in sequence, the third damping part is provided with a notch connected with the pressure dividing hole, the first damping part is located in the first pressure dividing cavity and has an outer diameter greater than the inner diameter of the second pressure dividing cavity, the second damping part and the third damping part are both located in the second pressure dividing cavity, and the hydraulic oil flowing from the third pressure dividing cavity is used to apply a linear driving force to the blocking ball to make the blocking ball move and abut against the end face of the notch.

[0012] In some embodiments, the valve body is further provided with a bypass channel connected with the third pressure dividing cavity, the bypass channel penetrates from the third pressure dividing cavity to the side of the valve body facing the control valve and has a bypass port.

[0013] The second aspect of the present application provides a hydraulic control system comprising a control valve and the pilot control valve as described above.

[0014] The third aspect of the present application provides a working machine comprising the hydraulic control system as described above.

[0015] Through the above technical solution, the valve body assembly of the pilot control valve has a first valve cavity inside, one end of the valve body assembly is used to be connected with a control valve, the control valve is used to supply oil to an actuator, and the end of the valve body assembly facing the control valve is provided with a control port; a floating valve core is located in the first valve cavity, the floating valve core comprises a floating core body, one end of the floating core body is movably inserted into the valve body assembly, and the other end can movably penetrate the control port; a pressure dividing assembly comprises an elastic member and a first damping part, the elastic member is elastically connected between the inner wall of the valve body assembly and the floating core body, the first damping part is inserted into the floating core body, and the end of the floating core body away from the elastic member abuts against the control valve. When hydraulic oil enters the first valve cavity, the hydraulic oil flows out from the control port after being filtered by the first damping part, and the hydraulic oil flowing out from the control port drives the control piston to move; and the floating core body moves along the axial direction to penetrate the control port under the elastic driving of the elastic member, so as to change the oil passing area between the floating core body and the valve body assembly, so that the hydraulic oil output flow of the control port is also automatically adjusted, and then the smooth movement of the actuator can be realized while the response speed is improved, that is, the rapid pressure building of the control port is realized.

[0016] Other features and advantages of the embodiments of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings are included to provide a further understanding of embodiments of the application, and are incorporated in and constitute a part of this specification, illustrate embodiments of the application, and together with the description serve to explain principles of embodiments of the application. In the drawings: Figure 1 A hydraulic principle diagram of a pilot control valve of the present application; Figure 2 A structure diagram of a floating spool of a pilot control valve of the present application in a first position; Figure 3 A structure diagram of a floating spool of a pilot control valve of the present application in a middle position; Figure 4 A structure diagram of a floating spool of a pilot control valve of the present application in a second position; Figure 5 A structure diagram of a valve sleeve of a pilot control valve of the present application; Figure 6 A structure diagram of a floating spool of a pilot control valve of the present application; Figure 7 A structure diagram of a fourth damping of a pilot control valve of the present application; Figure 8 A structure diagram of a valve body of a pilot control valve of the present application.

[0018] Explanation of reference signs DETAILED DESCRIPTION

[0019] The specific embodiments of the present application will be described in detail below with reference to the drawings. It should be understood that the specific embodiments described herein are merely illustrative and explanatory and are not intended to limit the present application.

[0020] A pilot control valve, a hydraulic control system and a working machine according to the present application will be described below with reference to the drawings.

[0021] As shown in Figure 1 The present application provides a pilot control valve, which comprises a valve body assembly, a floating valve spool and a pressure dividing assembly; the valve body assembly has a first valve cavity 10 inside, one end of the valve body assembly is used to be connected with a control valve 40, the control valve 40 is used to supply oil to an actuator, the end of the valve body assembly towards the control valve 40 is provided with a control port Y; the floating valve spool is located in the first valve cavity 10, the floating valve spool comprises a floating spool 21, one end of the floating spool 21 is movably inserted into the assembly, the other end can be movably penetrated from the control port Y, that is, the other end of the floating spool 21 can be penetrated from the control port Y and abut against a control piston (as shown inFigure 1 As shown), of course, the other end of the floating core 21 may not pass through the control port Y but can still abut against the control piston. Both of these situations are within the protection scope of the present invention. The pressure dividing assembly includes an elastic element 31 and a first damper 32. The elastic element 31 is elastically connected between the inner wall of the valve body assembly and the floating core 21. The first damper 32 is inserted into the inner hole 22. The end of the floating core 21 facing away from the elastic element 31 abuts against the control piston of the control valve 40. The hydraulic oil flowing out from the control port Y is used to drive the control piston to move. The elastic element 31 is used to drive the floating core 21 to move between the first position and the second position to change the oil passage area between the floating core 21 and the valve body assembly, thereby adjusting the hydraulic oil output flow rate of the control port Y.

[0022] The valve body assembly includes a valve body 100 and a valve sleeve 20 located in the first valve chamber 10. One end of a floating core 21 is movably inserted into the valve sleeve 20. An elastic element 31 is elastically connected between the inner wall of the valve sleeve 20 and the floating core 21. When the elastic element 31 drives the floating core 21 to move axially, the hydraulic oil output flow rate of the control port Y can be adjusted by changing the oil flow area between the floating core 21 and the valve body 100, or by changing the oil flow area between the floating core 21 and the valve sleeve 20. The floating core 21 of this application can move with the control piston of the control valve 40, and thus adjust the hydraulic oil output flow rate of the control port Y accordingly. That is, the position change of the floating core 21 can automatically adjust the oil flow area between the floating core 21 and the valve body 100 or the valve sleeve 20, thereby enabling the actuator to perform smooth movement while improving the response speed, that is, to achieve rapid pressure build-up at the control port Y.

[0023] For ease of explanation, the following example illustrates how the positional change of the floating core 21 can automatically adjust the oil passage area between the floating core 21 and the valve body 100. In this embodiment, when there is no control oil input at the oil inlet or when control oil output has just begun, the floating core 21 is in the first position of L1 (e.g., Figure 2 As shown), the elastic element 31 has elastic potential energy due to compression deformation. At this time, the oil passage area formed by the cooperation between the end of the floating core 21 away from the elastic element 31 and the first valve chamber 10 of the valve body 100 is the largest, which makes the control port Y quickly build up pressure and ensure the rapid response of the actuator. As the control oil in the oil inlet continues to output, it pushes the control piston of the control valve 40 to move to the right, and the elastic element 31 drives the floating core 21 to move to the right accordingly. When the floating core 21 moves to the middle position of L2 ( Figure 3As shown, the inclined surface of the floating core 21 contacts the sharp corner of the valve body 100. At this time, the input oil passage area of ​​the control port Y becomes smaller, and the floating core 21 is in the L1-L2 stage, which is the rapid opening stage of the actuator. As the control oil in the oil inlet continues to output, it pushes the control piston to continue moving to the right. At this time, when the floating core 21 is disengaged from the control piston and is in the second position of L3 (as shown), the control piston is in the second position. Figure 4 As shown in the diagram, at this time, the elastic element 31 does not have elastic deformation, so the floating core 21 will not continue to move to the right, and the effective oil passage area of ​​the control port Y will not increase, remaining the same as the oil passage area in state L2. This ensures the stability of the output pressure of the control port Y, thus ensuring the smooth movement of the actuator. When the floating core 21 is in the L2-L3 stage, it is the smooth movement stage of the actuator. When the pressure at the oil inlet decreases or the actuator needs to be stopped, the control pressure oil at the control port Y pushes the floating core 21 to the left (L3-L1), causing the pressure oil at the control port Y to be quickly depressurized, thereby achieving a rapid stop or reset of the actuator.

[0024] Furthermore, since the floating core 21 of this application is provided with a first damper 32, when the pressure at the oil inlet fluctuates, part of the pressure generated by the fluctuation can be filtered by the first damper 32, thereby achieving a rapid response and smooth operation of the actuator.

[0025] In some embodiments, the valve sleeve 20 has a second valve chamber, which includes a first cavity 201, a second cavity 202, and a third cavity 203 that are sequentially connected axially and have progressively increasing inner diameters. An elastic element 31 is located within the second cavity 202 and its two ends are respectively connected to the end face of the second cavity 202 and the floating core 21. The floating core 21 is movably located within the third cavity 203, and a channel gap for hydraulic oil flow exists between the floating core 21 and the inner peripheral wall of the third cavity 203. In this embodiment, in the first position, the elastic element 31 is in a compressed state and exerts an elastic force on the floating core 21 in the direction of the control piston. When hydraulic oil enters from the inlet port X, the hydraulic oil is filtered by the first damper 32 and flows out along the inner hole 22 of the floating core 21. A portion of the oil flows out through the channel gap between the floating core 21 and the inner peripheral wall of the third cavity 203 and applies an axial pushing force to the control piston. Thus, under the elastic action of the elastic element 31, the floating core 21 moves to the right along with the control piston to the second position. When the floating core 21 moves between the first position and the second position, the hydraulic oil flow rate at the control port Y changes accordingly, thereby enabling the balance valve to respond quickly and operate smoothly.

[0026] In some embodiments, the first cavity 201 is provided with a second damper 33, the second damper 33 comprising a first end cover and a damping body connected with the first end cover, the first end cover being located at one end of the valve sleeve 20 away from the floating core 21 and having an outer diameter greater than an inner diameter of the first cavity 201, and the damping body being located in the first cavity 201. The second damper 33 can filter the hydraulic oil, thereby reducing the fluctuation of the hydraulic oil entering from the first cavity 201.

[0027] As shown in Figure 8 The first valve cavity 10 comprises a fourth cavity 101, a fifth cavity 102 and a sixth cavity 103 which are sequentially connected in the axial direction and have sequentially decreasing inner diameters, the valve sleeve 20 is located in the fourth cavity 101, the floating core 21 comprises a large-diameter portion 211, a valve seat 212 and a small-diameter portion 213 which are sequentially connected in the axial direction, the valve seat 212 comprises a circular truncated cone portion 2121 and a circular ring portion 2122, the outer diameter of the circular truncated cone portion 2121 decreases from the direction away from the large-diameter portion 211, and as the floating core 21 moves to the right, the distance between the circular truncated cone portion 2121 and the valve sleeve 20 gradually decreases until abutting against the inner wall of the valve body 100, so that the oil flow area between the circular truncated cone portion 2121 and the valve body 100 can be changed; the outer diameter of the circular ring portion 2122 is equal to the outer diameter of the end portion of the circular truncated cone portion 2121 and is smaller than the outer diameter of the small-diameter portion 213, the large-diameter portion 211 is movably located in the fifth cavity 102, the maximum outer diameter of the circular truncated cone portion 2121 is smaller than the inner diameter of the fifth cavity 102 and larger than the inner diameter of the sixth cavity 103, and the small-diameter portion 213 is movably located in the sixth cavity 103.

[0028] In this embodiment, the valve sleeve 20 is arranged in abutment with the inner peripheral wall of the fourth cavity 101, one end of the valve sleeve 20 away from the control port Y abuts against the stepped surface connecting the fourth cavity 101 and the fifth cavity 102, and the position of the entire valve sleeve 20 does not change when the floating core 21 moves in the valve sleeve 20. When the floating core 21 moves to the right under the pushing of the elastic member 31, the circular truncated cone portion moves to the position of the stepped surface connecting the fifth cavity 102 and the sixth cavity 103, at the first position, there is a certain distance between the circular truncated cone portion and the end surface of the fifth cavity 102, the flow-through gap area between the circular truncated cone portion and the fifth cavity 102 is maximum, and at this time, the hydraulic oil flow passing through the flow-through gap is maximum; when the floating core 21 moves to the second position, the circular truncated cone portion abuts against the end surface of the fifth cavity 102, at this time, the flow-through gap area between the circular truncated cone portion and the fifth cavity 102 is minimum, and at this time, the hydraulic oil flow passing through the flow-through gap is minimum, so that the output flow of the control port Y can be adjusted by the movement of the floating core 21.

[0029] As shown in Figure 6As shown, an oil passage 23 is provided on the outer periphery of the frustum portion. This oil passage 23 is inclined and communicates with the third cavity 203. The oil passage 23 compensates for the hydraulic oil flow between the frustum portion 2121 and the valve body 100. Hydraulic oil entering from the third cavity 203 flows through the channel formed between the oil passage 23 and the valve body 100 to the control port Y. Another portion flows directly out from the inner hole 22 and acts on the control piston. When the floating core 21 is in... Figure 2 At position L1, the oil flow area to control port Y is at its maximum. The effective flow rate of the hydraulic oil output from control port Y can be understood as the sum of the direct output flow rate of inner hole 22 and the flow rate of the passage between oil passage 23 and valve body 100. As the floating core 21 moves to the right... Figure 3 At position L2, the oil flow area to the control port Y is minimized. That is, the position of the floating core 21 determines the oil flow area of ​​the control port Y. During the process from L1 to L2, the oil flow area of ​​the control port Y gradually decreases, thereby achieving a fast response while ensuring continuous and stable output.

[0030] In some embodiments, the pilot control valve further includes an inlet connector 50 inserted into the first valve chamber 10. The inlet connector 50 and the valve sleeve 20 are spaced apart at the ends opposite to the floating core 21. The inlet connector 50 forms an inlet channel communicating with the first valve chamber 10, and a third damper 34 is provided inside the inlet connector 50. The third damper 34 is in the form of a filter screen. The end of the inlet connector 50 has an inlet port X, and an inlet channel is axially formed inside the inlet connector 50. Hydraulic oil entering from the inlet port X can flow into the first valve chamber 10 along the inlet channel. By providing the third damper 34 inside the inlet connector 50, the third damper 34 filters the hydraulic oil before it enters the first valve chamber 10, reducing pressure fluctuations at the inlet port X, thereby ensuring rapid response and smooth operation of the actuator.

[0031] In some embodiments, the valve body 100 is further provided with a pressure-dividing oil passage 38 that is perpendicular to and connected to the central axis of the first valve chamber 10. The pressure-dividing oil passage 38 is connected to an external hydraulic oil tank through a pipeline. The pressure-dividing oil passage 38 is provided with a fourth damper 35 and a blocking ball 37. The pressure-dividing oil passage 38 is used to divert the hydraulic oil in the first valve chamber 10, and the blocking ball 37 is used to connect or block the oil passage between the pressure-dividing oil passage 38 and the first valve chamber 10.

[0032] In this embodiment, such as Figure 5 As shown, the pressure-dividing oil circuit 38 is configured corresponding to the fourth chamber 101, and the valve sleeve 20 has an oil outlet 204, which is used to connect the third chamber 203 and the pressure-dividing oil circuit 38. Figures 2 to 4The arrows of the hydraulic oil flow shown can be seen that when the hydraulic oil pressure entering from the oil inlet port X of the oil inlet joint 50 produces greater fluctuation, the hydraulic oil filtered through the third damper 34 enters the first valve cavity 10 from the oil outlet cavity of the oil inlet joint 50, and then enters the second valve cavity through the second damper 33. A part of the hydraulic oil enters the pressure oil distribution passage 38 through the oil outlet hole 204 on the valve sleeve 20, thereby pushing the blocking ball 37 to move towards the fourth damper 35, so that the pressure oil distribution passage 38 and the second valve cavity are communicated through the oil outlet hole 204, that is, the oil passage communication between the pressure oil distribution passage 38 and the first valve cavity 10 can be realized, and the hydraulic oil in the pressure oil distribution passage 38 enters the external hydraulic oil tank through the pipeline, thereby realizing the pressure distribution of the oil inlet port X. Another part of the hydraulic oil enters the inner hole 22 of the floating core 21 to push the opening action of the balance valve.

[0033] In some embodiments, the pressure oil distribution passage 38 includes a first pressure distribution cavity 381, a second pressure distribution cavity 382 and a third pressure distribution cavity 383 connected in sequence and having inner diameters increasing in sequence, the third pressure distribution cavity 383 is communicated with the first valve cavity 10, and the blocking ball 37 is located in the second pressure distribution cavity 382 and has an outer diameter greater than the inner diameter of the first pressure distribution cavity 381. Figure 7 As shown, the fourth damper 35 is provided with a pressure distribution hole 36 in the axial direction and includes a first damper part 351, a second damper part 352 and a third damper part 353 connected in sequence, the third damper part 353 is provided with a notch communicated with the pressure distribution hole 36, the first damper part 351 is located in the first pressure distribution cavity 381 and has an outer diameter greater than the inner diameter of the second pressure distribution cavity 382, and the second damper part 352 and the third damper part 353 are both located in the second pressure distribution cavity 382, the hydraulic oil flowing from the third pressure distribution cavity 383 is used to exert a linear driving force on the blocking ball 37, so that the blocking ball 37 moves and abuts against the end face of the notch.

[0034] In this embodiment, in the initial state, since the outer diameter of the steel ball is greater than the inner diameter of the first pressure distribution cavity 381, the steel ball is located at the connection between the first pressure distribution cavity 381 and the second pressure distribution cavity 382 and separates the first pressure distribution cavity 381 and the second pressure distribution cavity 382. When the steel ball is pushed to move linearly towards the fourth damper 35 and abut against the end face of the notch after entering the first pressure distribution cavity 381 from the oil outlet hole 204, the first pressure distribution cavity 381 and the second pressure distribution cavity 382 are communicated, and the hydraulic oil from the oil outlet hole 204 can enter the second pressure distribution cavity 382 through the first pressure distribution cavity 381, and enter the pressure distribution hole 36 of the fourth damper 35 from the outer end face of the notch to flow. Since the pressure distribution hole 36 is communicated with the external hydraulic oil tank through the pipeline, the hydraulic oil in the pressure distribution hole 36 can flow into the hydraulic oil tank to realize pressure distribution.

[0035] In some embodiments, the valve body 100 is further provided with a bypass channel 39 in communication with the third pressure division cavity 383, the bypass channel 39 extending from the third pressure division cavity 383 to a side of the valve body 100 facing the control valve 40 and having a bypass port L. When the hydraulic oil pressure of the oil inlet port X is too large, part of the hydraulic oil entering the pressure division oil way 38 is discharged from the pressure division hole 36, and the other part flows out from the bypass channel 39 in communication with the pressure division oil way 38, thereby achieving the purpose of dividing the hydraulic oil of the oil inlet port X.

[0036] As shown in Figure 1 , the second aspect of the present application provides a hydraulic control system, comprising a control valve 40 and a pilot control valve as described above. Wherein, the control valve 40 can be a balance valve, as shown in Figures 2 to 4 , the pilot control valve is used for pilot control of the balance valve, of course, the pilot control valve of the present application is not limited to the pilot control of the balance valve, and similar application scenarios as the present structure also belong to the present application. The actuator can be a winch mechanism, a luffing mechanism, etc.

[0037] The third aspect of the present application provides a working machine, comprising a hydraulic control system as described above. Wherein, the working machine can be a crane, a excavator and other common machines in the prior art, since the working machine adopts all embodiments of the above-mentioned hydraulic control system, it has all the beneficial effects brought by the above-mentioned hydraulic control system, which will not be described in detail here.

[0038] In the description of the present application, it should be understood that the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0039] In the present application, unless otherwise specifically defined and limited, the terms "mounting", "connecting", "connecting", "fixing" and other terms should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected or in communication with each other; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0040] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are contained in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.

[0041] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and the person skilled in the art can make changes, modifications, replacements and variations to the above-described embodiments within the scope of the present application.

Claims

1. A pilot control valve, characterized in that, include: The valve body assembly has a first valve chamber (10) inside. One end of the valve body assembly is used to connect to the control valve (40). The valve body assembly has a control port (Y) at the end facing the control valve (40). A floating valve core is located in the first valve cavity (10) and includes a floating core body (21). One end of the floating core body (21) is movably inserted into the valve body assembly, and the other end can be movably inserted through the control port (Y). The pressure dividing assembly includes an elastic element (31) and a first damper (32). The elastic element (31) is elastically connected between the inner wall of the valve body assembly and the floating core (21). The first damper (32) is inserted into the floating core (21). One end of the floating core (21) away from the elastic element (31) is used to abut against the control piston of the control valve (40). Hydraulic oil flowing from the control port (Y) is used to drive the control piston to move, and the elastic element (31) is used to drive the floating core (21) to move axially and change the distance between the floating core (21) and the valve body assembly, so as to adjust the hydraulic oil output flow of the control port (Y).

2. The pilot control valve according to claim 1, characterized in that, The valve body assembly includes a valve body (100) and a valve sleeve (20) located in a first valve chamber (10). One end of the floating core (21) is movably inserted into the valve sleeve (20). The valve sleeve (20) has a second valve chamber. The second valve chamber includes a first cavity (201), a second cavity (202), and a third cavity (203) connected sequentially along the axial direction. The elastic element (31) is located in the second cavity (202) and its two ends are respectively connected to the end face of the second cavity (202) and the floating core (21). The floating core (21) is movably located in the third cavity (203).

3. The pilot control valve according to claim 2, characterized in that, The first cavity (201) is provided with a second damper (33), the second damper (33) includes a first end cap and a damping body connected to the first end cap. The first end cap is located at the end of the valve sleeve (20) away from the floating core (21) and its outer diameter is larger than the inner diameter of the first cavity (201). The damping body is located inside the first cavity (201).

4. The pilot control valve according to claim 2, characterized in that, The first valve chamber (10) includes a fourth chamber (101), a fifth chamber (102), and a sixth chamber (103) that are connected in sequence along the axial direction and whose inner diameters decrease in sequence. The valve sleeve (20) is located in the fourth chamber (101). The floating core (21) includes a large-diameter portion (211), a valve seat (212), and a small-diameter portion (213) that are connected in sequence along the axial direction. The valve seat includes a frustum portion (2121) and an annular portion (2122). The outer diameter of the frustum portion (2121) increases from the outer diameter towards the outer diameter. The outer diameter of the ring portion (2122) decreases from the large diameter portion (211) in the direction of the large diameter portion (2121). The outer diameter of the ring portion (2122) is equal to the outer diameter of the end of the frustum portion (2121) and smaller than the outer diameter of the small diameter portion (213). The large diameter portion (211) is located within the fifth cavity (102). The maximum outer diameter of the frustum portion (2121) is smaller than the inner diameter of the fifth cavity (102) and larger than the inner diameter of the sixth cavity (103). The small diameter portion (213) is located within the sixth cavity (103).

5. The pilot control valve according to claim 4, characterized in that, An oil passage (23) is provided on the outer periphery of the frustum portion (2121), and the oil passage (23) is connected to the third cavity (203).

6. The pilot control valve according to claim 2, characterized in that, The pilot control valve also includes an oil inlet connector (50) inserted into the first valve chamber (10). The oil inlet connector (50) and the valve sleeve (20) are arranged at a distance from one end of the floating core (21). The oil inlet connector (50) forms an oil inlet channel communicating with the first valve chamber (10). The oil inlet connector (50) is provided with a third damping (34).

7. The pilot control valve according to any one of claims 2 to 6, characterized in that, The valve body (100) is also provided with a pressure-dividing oil passage (38) that is perpendicular to and connected to the central axis of the first valve chamber (10). The pressure-dividing oil passage (38) is connected to an external hydraulic oil tank through a pipeline. The pressure-dividing oil passage (38) is provided with a fourth damper (35) and a blocking ball (37). The pressure-dividing oil passage (38) is used to divert the hydraulic oil in the first valve chamber (10). The blocking ball (37) is used to connect or block the oil passage between the pressure-dividing oil passage (38) and the first valve chamber (10).

8. The pilot control valve according to claim 7, characterized in that, The pressure distribution oil circuit (38) includes a first pressure distribution chamber (381), a second pressure distribution chamber (382), and a third pressure distribution chamber (383) that are connected in sequence and have increasing inner diameters. The third pressure distribution chamber (383) is connected to the first valve chamber (10). The barrier ball (37) is located in the second pressure distribution chamber (382) and its outer diameter is larger than the inner diameter of the first pressure distribution chamber (381). The fourth damper (35) has a pressure dividing hole (36) along the axial direction and includes a first damping part (351), a second damping part (352) and a third damping part (353) connected in sequence. The third damping part (353) has a notch that communicates with the pressure dividing hole (36). The first damping part (351) is located in the first pressure dividing cavity (381) and its outer diameter is larger than the inner diameter of the second pressure dividing cavity (382). The second damping part (352) and the third damping part (353) are both located in the second pressure dividing cavity (382). The hydraulic oil flowing in from the third pressure dividing cavity (383) is used to apply a linear driving force to the barrier ball (37) so that the barrier ball (37) moves and abuts against the end face of the notch.

9. The pilot control valve according to claim 8, characterized in that, The valve body (100) is also provided with a bypass channel (39) that communicates with the third pressure chamber (383). The bypass channel (39) extends from the third pressure chamber (383) to the side of the valve body (100) facing the control valve (40) and has a bypass port (L).

10. A hydraulic control system, characterized in that, Includes a control valve (40) and a pilot control valve according to any one of claims 1 to 9.

11. A type of operating machinery, characterized in that, Includes the hydraulic control system according to claim 10.

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