Novel valve rod regeneration structure for load sensing valve

Abstract

The application relates to a novel valve rod regeneration structure for a load-sensitive valve, and belongs to the technical field of hydraulic devices.The novel valve rod regeneration structure comprises a regeneration valve rod, the inner hole of the regeneration valve rod comprises a first cylindrical hole, a second cylindrical hole, a third cylindrical hole and a fourth cylindrical hole which are axially communicated and whose diameters gradually decrease, a small valve core which can slide is arranged in the second cylindrical hole, a spring seat for limiting the small valve core is arranged in the second cylindrical hole, and a reset spring is arranged between the small valve core and the spring seat; a regeneration hole leading to the second cylindrical hole and a regeneration throttling hole leading to the fourth cylindrical hole are arranged on the outer surface of the regeneration valve rod.The application realizes the regeneration function of a main valve, does not need to process the valve rod at both ends and has no slender through hole structure, the length of a regeneration oil way is shortened by about 2 / 3, the processing size of the regeneration valve rod is reduced by 1 / 2, and the number of assembled parts of a piece valve assembly is reduced by 6.

Description

Technical Field

[0001] This invention belongs to the field of hydraulic device technology, and relates to a novel valve stem regeneration structure for load-sensitive valves, and more particularly to a regenerated valve stem for recovering and reusing the potential energy of the entire working device. Background Technology

[0002] Taking the boom descent process during the overall operation of an excavator as an example, the weight of the boom and the load causes the hydraulic oil in the rodless chamber of the cylinder to generate pressure during the boom descent. The traditional hydraulic control valve consumes the energy of the high-pressure hydraulic oil in the rodless chamber of the cylinder through the throttle groove on the valve stem, thereby making the boom descent process smooth and controllable.

[0003] To achieve energy conservation and emission reduction, and precise and rational use of energy, the potential energy generated by the working device and load weight should be recovered during the three actions of boom lowering, stick closing, and bucket closing. This allows the main pump to operate at low pressure and with a small displacement, reducing the power required by the hydraulic system, thereby effectively reducing the engine load and fuel consumption, and achieving energy conservation and emission reduction. Furthermore, during these three actions, the main pump operates at a small displacement, and the output oil is insufficient to meet the operational requirements of the working device. To prevent damage to related parts such as cylinder cavitation and abnormal noise, the pressure oil recovered during these three actions is introduced into another chamber of the working cylinder through a hydraulically controlled regeneration oil circuit, achieving precise and rational reuse of energy.

[0004] Most load-sensitive control valves used in excavators are plate valves. The internal oil circuit structure of each plate valve body is compact. The regeneration circuit of the above-mentioned functions is difficult to realize on the plate valve body. Therefore, the existing regeneration oil circuit of the load-sensitive valve is basically realized on the valve stem. However, the existing valve stem has a long regeneration oil circuit channel, large oil circuit pressure loss, and complex regeneration structure, resulting in many processing dimensions, high difficulty, and high cost.

[0005] To achieve the oil circuit regeneration function of the main valve, while shortening the channel length of the valve stem regeneration oil circuit, reducing the processing difficulty of the valve stem regeneration oil circuit, and reducing the cost of hydraulic components, it is necessary to improve the structure of the existing regeneration valve stem for load-sensitive valves. Summary of the Invention

[0006] The technical problem to be solved by this invention is to address the issues of long regeneration oil circuit channels, large oil circuit pressure loss, and insufficient regeneration flow in the regeneration valve stem of existing load-sensitive control valves used in excavators, while also solving the problems of large processing dimensions, high difficulty, and high component cost of existing valve stem regeneration structures and plate valve regeneration assemblies.

[0007] To achieve the above objectives, the present invention provides a novel valve stem regeneration structure for a load-sensitive valve, comprising a regeneration valve stem. The inner bore of the regeneration valve stem includes a first cylindrical bore, a second cylindrical bore, a third cylindrical bore, and a fourth cylindrical bore that are axially interconnected and whose diameters decrease sequentially. The second cylindrical bore contains a slidable small valve core, a spring seat for limiting the small valve core, and a return spring disposed between the small valve core and the spring seat. The outer surface of the regeneration valve stem has a regeneration hole leading to the second cylindrical bore and a regeneration throttling hole leading to the fourth cylindrical bore.

[0008] Preferably, the spring seat is provided with a plug on the side away from the small valve core for defining the axial position of the spring seat within the regeneration valve stem.

[0009] Preferably, a sealing groove is provided between the screw plug and the regeneration valve stem, and an O-ring is provided in the sealing groove.

[0010] Preferably, the regeneration throttling orifice leads to the end of the fourth cylindrical orifice away from the third cylindrical orifice.

[0011] Preferably, the regeneration throttling orifice is provided in multiple ways and is arranged sequentially along the axial direction of the regeneration valve stem, with an axial arrangement distance of less than 8 mm; the regeneration throttling orifices at the same axial position on the regeneration valve stem are evenly distributed radially on the regeneration valve stem.

[0012] Preferably, the second cylindrical hole of the regeneration valve stem is clearance-fitted with the outer surface of the small valve core, and the small valve core is provided with a spherical surface that forms a line seal with the opening of the third cylindrical hole of the regeneration valve stem.

[0013] Preferably, the regeneration holes are located between the regeneration valve stem and the sealing point and clearance fit point of the small valve core line, and there are four regeneration holes evenly distributed in the radial direction of the valve stem.

[0014] Preferably, the front end of the small valve core is provided with a slender damping hole, and the ratio of the axial projected area of ​​the outer surface of the small valve core clearance fit to the axial projected area of ​​the small valve core line seal is 1.8-2.

[0015] Preferably, the outer surface of the regeneration valve stem is provided with an outer circular throttling groove, which is located in the spring cavity between the small valve core and the spring seat in the axial direction of the regeneration valve stem and is evenly distributed in the radial direction of the regeneration valve stem.

[0016] In summary, the present invention has the following beneficial technical effects:

[0017] The technical solution of this invention is to provide a novel valve stem regeneration structure without changing the existing valve casting. This structure reduces oil pressure loss and increases regeneration flow by shortening the length of the regeneration oil circuit. Furthermore, it improves production efficiency and reduces costs by reducing the number of machining dimensions and assembly parts related to the regeneration oil circuit.

[0018] The special structural design of the regenerating valve stem in this invention allows the valve stem regeneration oil passage to be completed by machining only one end of the valve stem, thus realizing the regeneration function of the main valve. It eliminates the need for machining at both ends of the valve stem and avoids the long and thin through-hole structure (as in the previous structure). Compared with the previous structure, this new regenerating valve stem structure shortens the length of the regeneration oil passage by about 2 / 3, reduces the machining size of the regenerating valve stem by 1 / 2, and reduces the number of assembly parts of the plate valve assembly by 6, demonstrating significant advantages.

[0019] Furthermore, when the main valve's regeneration function is used, the main pump only needs to output a portion of the pressure oil required for the action to complete the corresponding working device of the whole machine, thus achieving energy saving and emission reduction of the whole machine. The pressure oil required for the other action is replaced by regenerated oil, achieving precise and rational use of energy. Attached Figure Description

[0020] Figure 1 A schematic diagram of a novel valve stem regeneration structure for a load-sensitive valve;

[0021] Figure 2 This is a schematic diagram of flow regeneration for a novel valve stem regeneration structure used in a load-sensitive valve.

[0022] Reference numerals: 1. Regeneration valve stem; 2. Small valve core; 3. Return spring; 4. Spring seat; 5. Plug; 6. O-ring; 7. Regeneration oil passage hole; 8. Regeneration hole; 9. Regeneration throttling hole; 10. Outer circumferential throttling groove; 11. Slender damping hole. Detailed Implementation

[0023] To make the present invention more apparent and understandable, preferred embodiments are described below, along with accompanying drawings. Figure 1 , 2 The following is a detailed explanation.

[0024] This invention relates to a novel valve stem regeneration structure for load-sensitive valves, characterized by a short regeneration oil passage, low oil pressure loss, high processing efficiency of the regeneration valve stem 1, and low cost. Figure 1 As shown, it includes a regeneration valve stem 1 that is clearance-fitted with the main valve orifice, allowing the regeneration valve stem 1 to move axially within the main valve orifice to complete the reversing function. The regeneration valve stem 1 contains a small valve core 2, a return spring 3, a spring seat 4, a screw plug 5, and an O-ring 6.

[0025] The plug 5 is located at the orifice of the regeneration valve stem 1 and is connected by threads. The plug 5 contacts the surface of the spring seat 4, limiting the axial position of the spring seat 4 in the regeneration valve stem 1. An O-ring 6 is provided in the sealing groove between the plug 5 and the regeneration valve stem 1 to seal and prevent leakage.

[0026] The spring seat 4 is located inside the inner hole of the regeneration valve stem 1 and does not require precision fitting, ensuring the axial position of the internal parts of the regeneration valve stem 1; one end face of the spring seat 4 contacts the bottom surface of the screw plug 5, and the regeneration valve stem 1 and the spring seat 4 are clearance fitted.

[0027] The front sealing part of the small valve core 2 is set as a spherical surface. A return spring 3 is provided between the spring seat 4 and the small valve core 2 to ensure that the spherical surface of the front end of the small valve core 2 and the regeneration valve stem 1 form a line seal when the main valve is in the neutral position, and to ensure the leakage when the small valve core 2 is closed. The front end of the spherical surface of the small valve core 2 is provided with a slender damping hole 11. The rear sealing part of the small valve core 2 is a cylindrical surface, which is fitted with the inner hole of the regeneration valve stem 1 to play a sealing and guiding role. The small valve core 2 and the regeneration valve stem 1 need to be precisely fitted.

[0028] The regeneration oil passage hole 7 only needs to be machined at one end of the regeneration valve stem 1. The regeneration valve stem 1 is designed with a regeneration throttling hole 9, a regeneration oil passage hole 7, a regeneration hole 8, and an outer circumferential throttling groove 10. The precision machining dimensions of the valve stem inner hole are concentrated at the mating point with the small valve core 2. The outer circumferential throttling groove 10 of the regeneration valve stem 1 is located in the spring cavity between the small valve core 2 and the spring seat 4 in the axial direction of the valve stem, and is evenly distributed in the radial direction of the valve stem.

[0029] The regeneration throttling orifice 9 of the regeneration valve stem 1 is connected to the regeneration oil passage orifice 7, and the regeneration throttling orifice 9 is located at the bottom end of the regeneration oil passage orifice. The regeneration throttling orifices 9 are arranged sequentially along the valve stem axis, with an axial arrangement distance of less than 8 mm. The regeneration throttling orifices 9 with the same axial position on the regeneration valve stem 1 are evenly distributed radially on the valve stem.

[0030] The inner bore of the regeneration valve stem 1 includes four axial cylindrical holes of different sizes. The four axial cylindrical holes are, from the hexagonal end face of the screw plug 5 to the regeneration throttling hole 9 of the regeneration valve stem 1, the first cylindrical hole, the second cylindrical hole, the third cylindrical hole, and the fourth cylindrical hole, with their diameters decreasing sequentially. The orifice of the second cylindrical hole has a sealing groove, and the orifice of the third cylindrical hole has a conical sealing surface.

[0031] The four regeneration holes 8 of the regeneration valve stem 1 are evenly distributed radially on the valve stem, located between the regeneration valve stem 1 and the small valve core 2 at the line seal and the cylindrical surface mating point, and communicate with the second cylindrical hole.

[0032] The regeneration oil passage hole 7 of the regeneration valve stem 1 is the fourth cylindrical hole. The regeneration throttling hole 9 of the regeneration valve stem 1 is connected to the fourth cylindrical hole. The precision machining dimensions of the valve stem inner hole are concentrated at the bottom of the second cylindrical hole and the opening of the third cylindrical hole.

[0033] The second cylindrical hole of the regeneration valve stem 1 and the third cylindrical surface of the small valve core 2 are precisely fitted to form a gap seal. The spherical surface of the small valve core 2 and the conical surface of the opening of the third cylindrical hole of the regeneration valve stem 1 form a line seal. The axial projected area of ​​the third cylindrical hole of the regeneration valve stem 1 is S1, and the axial projected area of ​​the third cylindrical hole on the outer surface of the small valve core 2 is S2. The ratio of the projected area S2 to S1 is 1.8 to 2.

[0034] The valve stem regeneration oil passage is machined at one end to realize the regeneration function of the main valve. A regeneration throttling orifice 9 is provided on the outer circumference of the valve stem to adjust the regeneration flow rate according to the stroke of the regeneration valve stem 1. The important machining dimensions of the regeneration valve stem 1 are concentrated at the mating point with the small valve core 2. This part is machined in one piece using a forming tool to improve machining efficiency and quality.

[0035] The outer surface of the small valve core 2 includes three cylindrical surfaces of different diameters and a spherical surface. The three cylindrical surfaces are the first cylindrical surface, the second cylindrical surface, and the third cylindrical surface, with their diameters increasing sequentially. The first cylindrical surface and the third cylindrical surface are located at the two ends respectively.

[0036] One end of the first cylindrical surface is connected to one end of the spherical surface, and the other end of the spherical surface is connected to the second cylindrical surface; the second cylindrical surface and the third cylindrical surface are connected by a 30-degree chamfer; the third cylindrical surface is a guide surface and fits precisely with the second cylindrical hole of the regeneration valve stem 1 to play the role of gap sealing; the spherical surface of the small valve core 2 and the conical surface of the orifice of the third cylindrical hole of the regeneration valve stem 1 form a line seal.

[0037] The inner surface of the small valve core 2 includes three cylindrical surfaces of different diameters. The three cylindrical surfaces are the fourth cylindrical surface, the fifth cylindrical surface, and the sixth cylindrical surface, with their diameters increasing sequentially. The fourth cylindrical surface and the sixth cylindrical surface are located at the two ends respectively. The fourth cylindrical surface is the slender damping hole 11 of the small valve core 2.

[0038] The working process of this invention is as follows:

[0039] In use, the regeneration valve stem 1 is clearance-fitted with the main valve orifice, allowing the regeneration valve stem 1 to move left and right within the orifice. It moves to the right under the combined action of the pilot pressure oil at end B and the pilot return spring 3 at end A, and the valve stem operates as follows: Figure 2 The state shown;

[0040] The potential energy of the working device and load causes the oil in the return oil chamber of the working device to be in a high-pressure state, while the oil pressure in the inlet oil chamber of the working device is low. The pressure oil in the return oil chamber of the working device acts on the small valve core 2, causing the small valve core 2 to move to the right against the preload of the return spring 3. At this time, the line seal formed by the spherical surface at the front end of the small valve core 2 and the regeneration valve rod 1 is opened.

[0041] Part of the working device return oil pressure oil flows back to the oil tank through the outer circumferential throttling groove of the regeneration valve stem 1, and another part of the working device return oil pressure oil reaches the regeneration throttling hole 9 of the valve stem through the line seal formed by the spherical surface at the front end of the small valve core 2 and the regeneration valve stem 1, and the regeneration oil passage hole 7 of the regeneration valve stem 1. The working device return oil pressure oil is divided here.

[0042] According to the stroke of the valve stem, the regeneration throttling orifice 9 at different axial positions of the regeneration valve stem 1 is opened. The pressure oil in the return oil chamber of the working device merges with the output oil of the main pump after passing through the regeneration throttling orifice 9. The merged oil enters the oil inlet chamber of the working device through the check valve and the valve body oil passage, thus completing the oil regeneration function.

[0043] Because the main pump only needs to output a portion of the pressure oil required for the operation to complete the corresponding working device of the whole machine, the energy saving and emission reduction of the whole machine are achieved. The pressure oil required for the other operation is replaced by regenerated oil, achieving precise and rational use of energy.

[0044] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of the present invention.

Claims

1. A valve stem regeneration structure for a load sensing valve, characterized by: The device includes a regeneration valve stem (1), the inner bore of which includes a first cylindrical hole, a second cylindrical hole, a third cylindrical hole, and a fourth cylindrical hole that are axially interconnected and whose diameters decrease sequentially. The second cylindrical hole is provided with a slidable small valve core (2), a spring seat (4) for limiting the small valve core (2), and a return spring (3) provided between the small valve core (2) and the spring seat (4). The outer surface of the regeneration valve stem (1) is provided with a regeneration hole (8) leading to the second cylindrical hole and a regeneration throttling hole (9) leading to the fourth cylindrical hole. Through the multi-stage cylindrical holes, the slidable small valve core (2) controls the opening and closing of the regeneration hole (8) and the regeneration throttling hole (9) under hydraulic action, so that the high-pressure oil generated by the working cylinder due to the load is introduced into the regeneration oil circuit and merged with the low-pressure oil provided by the main pump.

2. The valve stem regenerative structure for a load sensing valve according to claim 1, characterized by: The spring seat (4) is provided with a screw plug (5) on the side away from the small valve core (2) to limit the axial position of the spring seat (4) in the regeneration valve stem (1).

3. The valve stem regenerative structure for a load sensing valve according to claim 2, characterized by: A sealing groove is provided between the plug (5) and the regeneration valve stem (1), and an O-ring (6) is provided in the sealing groove.

4. The valve stem regenerative structure for a load sensing valve of claim 1, wherein: The regenerated throttling orifice (9) leads to the end of the fourth cylindrical hole away from the third cylindrical hole.

5. The valve stem regenerative structure for a load sensing valve of claim 4, wherein: The regeneration throttling orifice (9) is provided in multiple ways and is arranged sequentially along the axial direction of the regeneration valve stem (1), with an axial arrangement distance of less than 8 mm; the regeneration throttling orifices (9) at the same axial position on the regeneration valve stem (1) are evenly distributed radially on the regeneration valve stem (1).

6. The valve stem regenerative structure for a load sensing valve of claim 1, wherein: The second cylindrical hole of the regeneration valve stem (1) is clearance-fitted with the outer surface of the small valve core (2), and the small valve core (2) is provided with a spherical surface that forms a line seal with the opening of the third cylindrical hole of the regeneration valve stem (1).

7. The valve stem regenerating structure for a load sensing valve according to claim 6, characterized by: The regeneration hole (8) is located between the regeneration valve stem (1) and the small valve core (2) at the line seal and clearance fit. The regeneration hole (8) is provided in multiple parts and is evenly distributed in the radial direction of the valve stem.

8. The valve stem regenerating structure for a load sensing valve according to claim 7, characterized by: The small valve core (2) has a slender damping hole (11) at its front end.

9. The valve stem regenerative structure for a load sensing valve of claim 1, wherein: The outer surface of the regeneration valve stem (1) is provided with an outer circular throttling groove (10). The outer circular throttling groove (10) is located in the spring cavity between the small valve core (2) and the spring seat (4) in the axial direction of the regeneration valve stem (1), and is evenly distributed in the radial direction of the regeneration valve stem (1).

10. The valve stem regenerative structure for a load sensing valve of claim 1, wherein: The ratio of the axial projected area of ​​the end of the small valve core (2) to the axial projected area of ​​the third cylindrical hole of the regeneration valve stem (1) is 1.8-2.

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