Adjustable buffer valve structure for hydraulic pilot handle

Abstract

The application relates to a kind of adjustable buffer valve structures for hydraulic pilot handle, belong to hydraulic device technical field, it includes valve sleeve, the conical valve core of slidingly passing in valve sleeve and the flow valve core of slidingly passing in conical valve core;Conical valve core is used to install the inner hole top of flow valve core and is equipped with gasket and spring, and the orifice of inner hole is equipped with steel wire baffle ring;Adjustable two-way flow valve can be formed by steel wire baffle ring, conical valve core, flow valve core, spring, gasket, and one-way valve can be formed by conical valve core and valve sleeve.The application only needs to select different number of gaskets according to the buffer requirements of adaptive machine type, adjusts the spring compression amount according to the thickness of gasket, and then adjusts the flow of two-way flow control valve.In addition, the flow sensing port of flow valve core is a thin-walled small hole, which is not sensitive to oil temperature change, so the hydraulic pilot handle using this structure has good consistency of whole machine buffer effect, and can significantly reduce the processing types of buffer related parts.

Description

Technical Field

[0001] This invention relates to a hydraulic pilot-operated buffer valve structure, and more particularly to an adjustable buffer valve structure for a hydraulic pilot handle, belonging to the technical field of hydraulic devices. Background Technology

[0002] Taking an excavator as an example, apart from slewing and traveling, all other machine movements are driven by hydraulic cylinders with limited stroke. During operation, the upper working device needs to be frequently started and stopped. Because each working device—upper, boom, stick, and bucket—has a large mass, the working device will generate a large inertia during frequent starts and stops, which will have a huge impact on the excavator's structural components and hydraulic system. This will affect the stability of the machine, the driving experience, and the work efficiency during operation; in severe cases, it will damage the structural components and hydraulic system, affecting the reliability and service life of the machine.

[0003] Adding a throttle orifice or a one-way throttle valve to the pilot port of the main control valve in the hydraulic system is an existing solution to address the impact of the working device. However, the buffering effect of adding a throttle orifice or a one-way throttle valve to the pilot port of the main control valve is inconsistent, mainly because: the relevant throttling dimensions of the throttle orifice or one-way throttle valve are very small, difficult to manufacture, and the overall buffering effect of the machine is highly sensitive to the relevant throttling dimensions; the installation of the throttle orifice or one-way throttle valve at the pilot port of the main valve results in a small volume of controllable oil. To solve the above problems, the buffering structure of the existing hydraulic pilot handle of the machine needs to be improved. Summary of the Invention

[0004] The technical problem to be solved by this invention is to solve the problem of large impact during the start-up and shutdown of existing excavator working devices; at the same time, to solve the problems of poor consistency of the overall machine's buffering effect, inability to adjust the buffering effect, and large variety of buffer-related parts.

[0005] To achieve the above objectives, the present invention provides an adjustable buffer valve structure for a hydraulic pilot handle, comprising a valve sleeve, a conical valve core slidably inserted within the valve sleeve, and a flow valve core slidably inserted within the conical valve core; the conical valve core has an inner hole with its opening facing downwards, a gasket and a spring are provided at the top of the inner hole, and a wire retaining ring is provided at the opening of the inner hole; an adjustable two-way flow valve can be formed by the wire retaining ring, the conical valve core, the flow valve core, the spring, and the gasket, and a one-way valve can be formed by the conical valve core and the valve sleeve.

[0006] Preferably, it is built into the secondary pressure reducing port of the hydraulic pilot handle.

[0007] Preferably, the inner hole of the valve sleeve and the outer cylindrical surface of the conical valve core are in clearance fit and serve as axial guides, the conical surface of the valve sleeve and the conical surface of the conical valve core are in cooperation to form a line seal, and the outer cylindrical surface of the valve sleeve is in clearance fit with the inner hole of the hydraulic pilot handle base plate.

[0008] Preferably, the outer cylindrical surface of the flow valve core is clearance-fitted with the inner hole of the cone valve core; the two end faces of the spring are in contact with the end face that restricts the flow valve core and the end face of the gasket, respectively; the flow sensing port of the flow valve core is a thin-walled small hole.

[0009] Preferably, the outer surface of the cone valve core is provided with a first cylindrical surface, a second cylindrical surface, and a third cylindrical surface; the first cylindrical surface has a radial dimension of 15 and is provided with a first guide groove in the radial direction; the second cylindrical surface has a radial dimension that forms an H7 / g6 clearance fit with the inner hole of the valve sleeve to provide axial guidance.

[0010] Preferably, the cone valve core has a cone surface angle of 90 degrees that contacts the 100-degree cone surface of the valve sleeve, forming a line seal to function as a one-way valve; the inner hole of the cone valve core has a 30-degree chamfer between its end faces to facilitate the assembly of the flow valve core; the inner hole opening has an installation groove for the steel wire retaining ring; and the radial dimension of the cone valve core is 5 with a tolerance of H7.

[0011] Preferably, the radial dimension of the outer cylindrical surface of the valve sleeve is 17 with a tolerance of h6, and the radial dimension of the mounting hole at the secondary pressure reducing port of the hydraulic pilot handle is 17 with a tolerance of H7, forming an H7 / h6 clearance fit. The bottom of the mounting hole with a radial dimension of 17 is also provided with a bottom end face with a radial dimension equal to that of the transition hole to limit the axial position of the cone valve core when it is opened. In addition, the bottom end face of the transition hole communicates with the external oil hole and is provided with a chamfer with a major diameter of 14 and an angle of 120 degrees. Here, the chamfer and the four radially evenly distributed guide grooves on the first cylindrical surface of the outer surface of the cone valve core serve to connect the oil passage.

[0012] Preferably, the radial dimension of the valve sleeve inner hole is 10 with a tolerance of H7, and the inner hole is provided with multiple second guide grooves; the valve sleeve inner hole and the ground end face are provided with a conical surface with an angle of 100 degrees.

[0013] Preferably, the outer surface of the flow valve core is provided with a fourth cylindrical surface, a fifth cylindrical surface, and a sixth cylindrical surface; the fourth cylindrical surface and the sixth cylindrical surface have the same radial dimension and a radial dimension of 5 with a tolerance of g6, forming an H7 / g6 clearance fit with the inner hole of the cone valve core with a radial dimension of 5 and a tolerance of H7, and playing an axial guiding role; the sixth cylindrical surface has a radial dimension of 4, and the ring formed by it, the fourth cylindrical surface, and the sixth cylindrical surface is a flow guide ring; the inner hole of the flow valve core is provided with a first cylindrical hole, a second cylindrical hole, and a third cylindrical hole of different sizes from the steel wire retaining ring to the spring.

[0014] Preferably, the radial dimension of the first cylindrical hole is 0.5 or 0.8, which is designed with thin walls and small holes; the radial dimension of the third cylindrical hole is 2, and the second throttling hole is provided between the third cylindrical hole and the fifth cylindrical surface of the flow valve core.

[0015] In summary, the present invention has the following beneficial technical effects:

[0016] The adjustable buffer-type hydraulic pilot handle structure design of this invention only requires selecting different numbers of shims according to the buffering requirements of the compatible model. The spring compression is adjusted according to the thickness of the shims, thereby adjusting the flow rate of the two-way flow control valve. In addition, the flow sensing port of the flow valve core is a thin-walled small hole, which is not sensitive to changes in oil temperature. Therefore, the hydraulic pilot handle with this structure has good consistency in the overall buffering effect. Only 6 parts are needed to meet the different requirements of different tonnage and different types of complete machines, which can significantly reduce the types of buffer-related parts to be processed.

[0017] This invention discloses an adjustable buffer valve structure for a hydraulic pilot handle, installed at the secondary pressure port of an existing hydraulic pilot handle. To ensure the responsiveness of the entire machine's working device, a one-way valve is designed. To address the issues of large impacts and inconsistent buffering across the entire machine, an adjustable two-way flow valve is designed. Because the buffering effect is controlled by the adjustable two-way flow valve, it is easy to perform factory calibration tests and inspections on hydraulic pilot handles with different buffering requirements, thus effectively ensuring the consistency of the overall machine's buffering effect. Through this improvement to the hydraulic pilot handle, this hydraulic pilot handle can be used universally with machines of different tonnages and types, while also reducing the variety of related parts that need to be processed in the factory.

[0018] The present invention discloses an adjustable buffer valve structure for a hydraulic pilot handle. Simply by adding an installation hole for the adjustable buffer valve at the secondary pressure reducing port of the hydraulic pilot handle, the adjustable buffer valve can be built into the hydraulic pilot handle. The one-way valve function of the adjustable buffer valve ensures good rapid response and no lag when the handle is operated. The buffering function of the adjustable buffer valve is controlled by an adjustable two-way flow valve, resulting in stable and consistent buffering effects, facilitating calibration and testing during factory testing. Furthermore, because its buffering effect is adjustable, it can be adapted to different tonnages and types of complete machines, reducing the number of related parts processed in the factory. Attached Figure Description

[0019] Figure 1 This is a hydraulic schematic diagram of an adjustable buffer valve structure for a hydraulic pilot handle according to the present invention.

[0020] Figure 2 This is a schematic diagram of the overall structure of an adjustable buffer valve for a hydraulic pilot handle according to the present invention.

[0021] Figure 3 This is a schematic diagram of the flow valve core in the adjustable buffer valve structure for a hydraulic pilot handle according to the present invention;

[0022] Figure 4 This is a first-view structural schematic diagram of the cone valve core in the adjustable buffer valve structure for a hydraulic pilot handle according to the present invention.

[0023] Figure 5 This is a second-view structural diagram of the cone valve core in an adjustable buffer valve structure for a hydraulic pilot handle according to the present invention.

[0024] Figure 6 This is a first-view structural diagram of the valve sleeve in an adjustable buffer valve structure for a hydraulic pilot handle according to the present invention.

[0025] Figure 7 This is a second-view structural diagram of the valve sleeve in an adjustable buffer valve structure for a hydraulic pilot handle according to the present invention.

[0026] Figure 8 This is a schematic diagram of an adjustable buffer valve structure for a hydraulic pilot handle, which is built into the secondary pressure reducing port of the hydraulic pilot handle according to the present invention.

[0027] Figure 9 for Figure 8 A schematic diagram of the structure in section A when it functions as a check valve;

[0028] Figure 10 for Figure 8 A schematic diagram of the structure in section A implementing the buffer function of the adjustable two-way flow valve.

[0029] Reference numerals: 1. Wire retaining ring; 2. Conical valve core; 21. First cylindrical surface; 22. Second cylindrical surface; 23. Third cylindrical surface; 24. First throttling orifice; 25. First guide groove; 3. Flow valve core; 31. Fourth cylindrical surface; 32. Fifth cylindrical surface; 33. Sixth cylindrical surface; 34. First cylindrical hole; 35. Second cylindrical hole; 36. Third cylindrical hole; 37. Second throttling orifice; 4. Valve sleeve; 41. Second guide groove; 5. Spring; 6. Gasket. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] This invention discloses an adjustable buffer valve structure for a hydraulic pilot handle. The invention includes a wire retaining ring 1, a cone valve core 2, a flow valve core 3, a valve sleeve 4, a spring 5, and a gasket 6. The wire retaining ring 1, the cone valve core 2, the flow valve core 3, the spring 5, and the gasket 6 form an adjustable two-way flow valve, and the cone valve core 2 and the valve sleeve 4 form a check valve. The check valve and the adjustable two-way flow valve are an integrated structure, which is installed at the secondary pressure port of the hydraulic pilot handle.

[0032] In the check valve, the inner hole of the valve sleeve 4 and the outer cylindrical surface of the cone valve core 2 are in clearance fit and play an axial guiding role. The cone surface of the valve sleeve 4 and the cone surface of the cone valve core 2 are in contact to form a line seal. The outer cylindrical surface of the valve sleeve 4 is in clearance fit with the inner hole of the hydraulic pilot handle base plate.

[0033] In the adjustable two-way flow valve, the outer cylindrical surface of the flow valve core 3 is clearance-fitted with the inner hole of the cone valve core 2; the spring 5 and the gasket 6 are located between the inner hole of the cone valve core 2 and the flow valve core 3, and the two end faces of the spring 5 are in contact with the end face of the flow valve core 3 and the end face of the gasket 6, respectively; the flow sensing port of the flow valve core 3 is a thin-walled small hole, so that the flow rate is independent of the viscosity of the oil. The number of gaskets 6 is selected according to different buffering requirements to adjust the flow rate of the adjustable two-way flow valve; the wire retaining ring 1 is located at the inner hole of the cone valve core 2 to limit the axial displacement of the flow valve core 3.

[0034] The outer surface of the cone valve core 2 includes three cylindrical surfaces of different diameters and a cone surface. The three cylindrical surfaces are a first cylindrical surface 21, a second cylindrical surface 22, and a third cylindrical surface 23. The first cylindrical surface 21 has four first guide grooves 25 evenly distributed radially. The second cylindrical surface 22 has two symmetrically distributed first throttling holes 24. The third cylindrical surface 23 has a clearance fit with the inner hole of the valve sleeve 4 to provide axial guidance.

[0035] The inner hole of the cone valve core 2 has a 30-degree chamfer between the end faces to facilitate the assembly of the flow valve core 3. The inner hole opening is provided with a mounting groove for the wire retaining ring 1. The inner hole of the cone valve core 2 is clearance-fitted with the fourth cylindrical surface 31 and the sixth cylindrical surface 33 on the outer surface of the flow valve core 3.

[0036] The outer surface of the flow valve core 3 includes three axial cylinders, namely the fourth cylindrical surface 31, the fifth cylindrical surface 32, and the sixth cylindrical surface 33. The fourth cylindrical surface 31 and the sixth cylindrical surface 33 have the same radial dimension. The ring formed by the fifth cylindrical surface 32, the fourth cylindrical surface 31, and the sixth cylindrical surface 33 is a flow guide ring.

[0037] The inner bore of the flow valve core 3 includes three axial cylindrical holes of different sizes. These three axial cylindrical holes, from the wire retaining ring 1 to the spring 5, are sequentially designated as the first cylindrical hole 34, the second cylindrical hole 35, and the third cylindrical hole 36. The first cylindrical hole 34 serves as a flow guide, the second cylindrical hole 35 is the flow sensing port of the flow valve core 3 and employs a thin-walled, small-hole design, and two second throttling holes 37 are provided between the third cylindrical hole 36 and the fifth cylindrical surface 32 of the flow valve core 3.

[0038] The outer cylindrical surface of the valve sleeve 4 of this invention has a radial dimension of 17 and a tolerance of h6. The mounting hole at the secondary pressure reducing port of the hydraulic pilot handle has a radial dimension of 17 and a tolerance of H7, forming an H7 / h6 clearance fit. The bottom of the mounting hole also has a transition hole with a radial dimension of 15.5. The bottom end face of the transition hole is used to limit the axial position of the cone valve core 2 when it is opened. In addition, the bottom end face of the transition hole communicates with the external oil hole and has a chamfer with a major diameter of 14 and an angle of 120 degrees. Here, the chamfer and the four first guide grooves 25 evenly distributed radially on the first cylindrical surface 21 of the outer surface of the cone valve core 2 serve to connect the oil passage. The inner hole of the valve sleeve 4 has a radial dimension of 10 and a tolerance of H7, and the inner hole has four second guide grooves 41. The inner hole of the valve sleeve 4 has a conical surface with an angle of 100 degrees at the bottom end face.

[0039] In the cone valve core 2, the first cylindrical surface 21 has a radial dimension of 15 and four radially evenly distributed first guide grooves 25; the second cylindrical surface 22 has a radial dimension of 8.5 and is provided with two symmetrically distributed first throttling holes 24; the third cylindrical surface 23 has a radial dimension of 10 and a tolerance of g6, forming an H7 / g6 clearance fit with the inner hole of the valve sleeve 4 to provide axial guidance. The cone angle of the cone valve core 2 is 90 degrees, which contacts the 100-degree cone surface of the valve sleeve 4, forming a line seal to function as a one-way valve. The inner hole of the cone valve core 2 has a 30-degree chamfer between the end faces to facilitate the assembly of the flow valve core 3. The inner hole opening is provided with an installation groove for the wire retaining ring 1. The radial dimension of the cone valve core 2 is 5 and the tolerance is H7.

[0040] In the flow valve core 3, the fourth cylindrical surface 31 and the sixth cylindrical surface 33 have the same radial dimension and a radial dimension of 5 with a tolerance of g6. They form an H7 / g6 clearance fit with the inner hole of the cone valve core 2, which has a radial dimension of 5 and a tolerance of H7, and serve as an axial guide. The sixth cylindrical surface 33 has a radial dimension of 4, and the ring formed by it, the fourth cylindrical surface 31, and the sixth cylindrical surface 33 is a flow guide ring. The first cylindrical hole 34 has a radial dimension of 2.5 and serves as a flow guide. The second cylindrical hole 35 is the flow sensing port of the flow valve core 3. It adopts a thin-walled small hole design with a radial dimension of 0.5 or 0.8. The third cylindrical hole 36 has a radial dimension of 2 and two throttling holes are provided between it and the fifth cylindrical surface 32 of the flow valve core 3.

[0041] The flow valve core 3 is installed inside the conical valve core 2, and its axial position is restricted by the steel wire retaining ring 1 at the orifice of the conical valve core 2. A spring 5 and a gasket 6 are installed between the flow valve core 3 and the bottom of the conical valve core 2. The spring 5 exerts a spring force on the flow valve core 3, and the spring 5 has low stiffness. The number of gaskets 6 is selected according to the buffering requirements of the specific model. By adjusting the compression of the spring 5, the control flow of the flow valve core 3 is adjusted.

[0042] In use, with the hydraulic pilot handle in the neutral position, the secondary pressure reducing port of the handle is connected to the drain port. The line seal formed by the cone valve core 2 and the cone of the valve sleeve 4 opens due to the weight of the cone valve core 2, thus connecting the pilot chamber of the main valve to the drain port, ensuring that the main valve reset will not cause malfunction of the entire machine. In the working state of the hydraulic pilot handle, due to the action of the handle valve core, the secondary pressure reducing port of the handle generates pilot control pressure. The cone valve core 2, under the weight of the pilot hydraulic press, opens the line seal formed by the cone valve core 2 and the cone of the valve sleeve 4. The secondary pressure reducing port of the handle connects to the pilot chamber of the main valve through this opening, completing the control of the main valve by the hydraulic pilot handle.

[0043] When the hydraulic pilot handle returns from the working state to the neutral state, the handle valve core resets, and its secondary pressure reducing port connects to the drain port. The hydraulic oil in the pipeline connecting the pilot chamber of the main valve and the handle is still pressurized. Under this pressure, the cone valve core 2 overcomes its own weight and forms a line seal with the cone of the valve sleeve 4 to close the check valve. At this time, the hydraulic oil needs to return to the secondary pressure reducing port and drain port of the handle through the flow valve core 3. When the hydraulic oil flows through the flow sensing port of the flow valve core 3, a pressure loss occurs at the flow sensing port. The pressure before the flow sensing port (i.e., the side of the wire retaining ring 1) is greater than the pressure after the flow sensing port (i.e., the side of the spring 5). The flow valve core 3 moves towards the spring 5 side under the action of hydraulic pressure. The guide ring of the flow valve core 3 vibrates axially relative to the symmetrically distributed first throttling holes 24 on the second cylindrical surface 22 of the outer surface of the cone valve core 2, adjusting the flow rate through the flow sensing port, so that the hydraulic pressure and spring force on the flow valve core 3 are dynamically balanced. Because the spring force and the area of ​​the flow sensing port are constant in the equilibrium state, the oil in the pilot chamber can return to the oil tank at a constant rate, delaying the reset of the main valve stem. This reduces the impact when the working device stops, protecting the overall structural components and hydraulic system. By adjusting the number of shims 6, different spring forces of spring 5 can be achieved in the equilibrium state, resulting in different buffering effects.

[0044] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An adjustable buffer valve structure for a hydraulic pilot handle, characterized in that: The valve includes a valve sleeve (4), a conical valve core (2) that slides through the valve sleeve (4), and a flow valve core (3) that slides through the conical valve core (2). The conical valve core (2) has an inner hole for mounting the flow valve core (3) with the opening facing downward. A gasket (6) and a spring (5) are provided at the top of the inner hole, and a wire retaining ring (1) is provided at the opening of the inner hole. An adjustable two-way flow valve can be formed by the wire retaining ring (1), the conical valve core (2), the flow valve core (3), the spring (5), and the gasket (6). A one-way valve can be formed by the conical valve core (2) and the valve sleeve (4). The outer surface of the conical valve core (2) includes three cylindrical surfaces of different diameters and a conical surface. In the one-way valve, the inner hole of the valve sleeve (4) and the outer cylindrical surface of the cone valve core (2) are in clearance fit and play an axial guiding role. The cone surface of the valve sleeve (4) and the cone surface of the cone valve core (2) are in cooperation to form a line seal. The outer cylindrical surface of the valve sleeve (4) is in clearance fit with the inner hole of the hydraulic pilot handle base plate. In the adjustable two-way flow valve, the outer cylindrical surface of the flow valve core (3) is clearance-fitted with the inner hole of the cone valve core (2); the spring (5) and the gasket (6) are located between the inner hole of the cone valve core (2) and the flow valve core (3), and the two end faces of the spring (5) are in contact with the end face of the flow valve core (3) and the end face of the gasket (6), respectively; the flow sensing port of the flow valve core (3) is a thin-walled small hole.

2. The adjustable buffer valve structure for a hydraulic pilot handle according to claim 1, characterized in that: It is built into the secondary pressure reducing port of the hydraulic pilot handle.

3. The adjustable buffer valve structure for a hydraulic pilot handle according to claim 2, characterized in that: The outer surface of the cone valve core (2) is provided with a first cylindrical surface (21), a second cylindrical surface (22), and a third cylindrical surface (23); the first cylindrical surface (21) is provided with a first guide groove (25) in the radial direction; the second cylindrical surface (22) is provided with a plurality of symmetrically distributed first throttling holes (24); the third cylindrical surface (23) is fitted with the inner hole of the valve sleeve (4) to provide axial guidance.

4. The adjustable buffer valve structure for a hydraulic pilot handle according to claim 3, characterized in that: The cone valve core (2) has a cone angle of 90 degrees and contacts the 100-degree cone surface of the valve sleeve (4) to form a line seal and function as a one-way valve. The inner hole of the cone valve core (2) has a 30-degree chamfer between the end faces to facilitate the assembly of the flow valve core (3). The inner hole opening has an installation groove for the wire retaining ring (1).

5. The adjustable buffer valve structure for a hydraulic pilot handle according to claim 4, characterized in that: The outer cylindrical surface of the valve sleeve (4) is fitted with the mounting hole at the secondary pressure reducing port of the hydraulic pilot handle with clearance. The bottom of the mounting hole is also provided with a transition hole. The bottom end face of the transition hole is used to limit the axial position of the cone valve core (2) when it is opened. In addition, the bottom end face of the transition hole is connected to the external oil hole and is provided with a chamfer of 120 degrees. Here, the chamfer and the first cylindrical surface (21) of the outer surface of the cone valve core (2) are radially evenly distributed with four guide grooves to connect the oil circuit.

6. The adjustable buffer valve structure for a hydraulic pilot handle according to claim 5, characterized in that: The valve sleeve (4) has a plurality of second guide grooves (41) in its inner hole; the valve sleeve (4) has a conical surface with an angle of 100 degrees at its inner hole and bottom end face.

7. The adjustable buffer valve structure for a hydraulic pilot handle according to claim 6, characterized in that: The outer surface of the flow valve core (3) is provided with a fourth cylindrical surface (31), a fifth cylindrical surface (32), and a sixth cylindrical surface (33); the fourth cylindrical surface (31) and the sixth cylindrical surface (33) have the same radial dimension, and are in clearance fit with the inner hole of the cone valve core (2) and play an axial guiding role; the ring formed by the sixth cylindrical surface (33), the fourth cylindrical surface (31), and the sixth cylindrical surface (33) is a flow guide ring; the inner hole of the flow valve core (3) is provided with a first cylindrical hole (34), a second cylindrical hole (35), and a third cylindrical hole (36) of different sizes from the wire retaining ring (1) to the spring (5).

8. The adjustable buffer valve structure for a hydraulic pilot handle according to claim 7, characterized in that: The first cylindrical hole (34) serves as a flow guide; the second cylindrical hole (35) is the flow sensing port of the flow valve core (3), and adopts a thin-walled small hole design; a second throttling hole (37) is provided between the third cylindrical hole (36) and the fifth cylindrical surface (32) of the flow valve core (3).

Images