阅读说明：本技术 一种液压比例阀阀芯及其表面织构加工工艺 (Hydraulic proportional valve core and surface texture processing technology thereof ) 是由 冯永强 林广� 于 2020-12-30 设计创作，主要内容包括：本发明提供了一种液压比例阀阀芯及其表面织构加工工艺,涉及液压阀技术领域,在阀芯与阀套之间的密封面上设有表面织构,表面织构包括若干有序排列在阀芯密封面上的凹坑,凹坑为金字塔结构且金字塔塔尖位于凹坑坑底位置。表面织构采用数控机床压滚加工工艺加工形成,加工工艺包括：S1、设计制造表面织构的织构模具；S2、对阀芯外表面进行精磨外圆；S3、利用数控机床和织构模具对阀芯外表面进行表面织构加工；S4、利用数控珩磨机采用三维气浮夹具对阀芯外表面进行珩磨加工。本发明采用表面织构工艺在液压比例阀阀芯表面形成表面织构,解决阀芯工作油膜保持问题,提高液压比例阀的工作可靠性和使用寿命。(The invention provides a valve core of a hydraulic proportional valve and a surface texture processing technology thereof, and relates to the technical field of hydraulic valves. The surface texture is processed and formed by adopting a numerical control machine tool press-rolling processing technology, and the processing technology comprises the following steps: s1, designing and manufacturing a texture mould with a surface texture; s2, performing accurate grinding on the outer surface of the valve core; s3, performing surface texture processing on the outer surface of the valve core by using a numerical control machine tool and a texture mould; and S4, honing the outer surface of the valve core by using a three-dimensional air floatation clamp by using a numerical control honing machine. The surface texture is formed on the surface of the valve core of the hydraulic proportional valve by adopting a surface texture process, so that the problem of maintaining a working oil film of the valve core is solved, the working reliability of the hydraulic proportional valve is improved, and the service life of the hydraulic proportional valve is prolonged.)

1. The valve core of the hydraulic proportional valve is characterized in that: the valve core is characterized in that a surface texture (2) is arranged on a sealing surface between the valve core (1) and the valve sleeve, the surface texture (2) comprises a plurality of pits (21) which are orderly arranged on the sealing surface of the valve core (1), the pits (21) are pyramid structures, and pyramid tips are positioned at the bottoms of the pits (21).

2. The hydraulic proportional valve spool of claim 1, wherein: the depth of each pit (21) in the surface texture (2) is 1-2 μm, the side length of the opening side is 75-120 μm, the distance between adjacent pits (21) is 100-200 μm, and the area occupancy rate of the surface texture (2) is 5-35%.

3. The hydraulic proportional valve spool according to claim 1 or 2, wherein: the surface texture (2) is formed by adopting a press-rolling processing technology of a numerical control machine (3).

4. A surface texture processing technology for a valve core of a hydraulic proportional valve is characterized by comprising the following steps:

s1, designing a texture mould (4) for manufacturing the surface texture (2); the surface of the texture mould (4) is provided with a plurality of conical protrusions (42) matched with the concave pits (21) in the surface texture (2), the height of each conical protrusion (42) is 1.2-2.5 mu m, the side length of the bottom edge is 90-145 mu m, and the distance between every two adjacent conical protrusions (42) is 85-165 mu m;

s2, performing accurate grinding on the outer surface of the valve core (1); the surface roughness is controlled to be 1-1.5 mu m;

s3, processing the surface texture (2) of the outer surface of the valve core (1) by using a numerical control machine (3) and the texture mould (4); the valve core (1) is positioned, rotated and installed on a numerical control machine tool (3), the texture mold (4) is installed on one side of the valve core (1), the numerical control machine tool (3) applies a load perpendicular to the valve core (1) to the texture mold (4), and the texture mold (4) enables a sealing surface of the valve core (1) to generate a deformation indentation to form a surface texture (2) in the rotating process of the valve core (1);

s4, honing the outer surface of the valve core (1) by using a three-dimensional air floatation clamp through a numerical control honing machine; the geometric tolerance of the honing process meets the following requirements: the cylindricity is less than or equal to 0.5-1 μm, and the surface roughness RZ is 0.1-0.5 μm.

5. The surface texture machining process for the valve core of the hydraulic proportional valve according to claim 4, characterized in that: in S3, the rotating speed N of the valve core (1) is 1000-4000r/min, and the load F applied to the texture mould (4) by the numerical control machine tool (3) is 20-200N.

6. The surface texture machining process for the valve core of the hydraulic proportional valve according to claim 5, characterized in that: and a hardness tester (31) is arranged on the numerical control machine tool (3) and is used for controlling the load applied to the texture mould (4) by the numerical control machine tool (3).

7. The surface texture machining process for the valve core of the hydraulic proportional valve according to claim 6, characterized in that: and S3, spraying a lubricant on the texture die (4) in the machining process, wherein the spraying flow q of the lubricant is 0.5-1L/min.

Technical Field

The invention relates to the technical field of hydraulic valves, in particular to a valve core of a hydraulic proportional valve and a surface texture processing technology thereof.

Background

Compared with other valves, the hydraulic proportional valve has higher precision requirements, and the high-precision honing processing of the valve core is mainly realized by a numerical control honing machine at present, but the effect state required by the sliding of the hydraulic proportional valve cannot be achieved. The reason is that the accumulated error generated by the traditional honing process method is large, the external stress fluctuation borne by the hinge tool is large, and the valve core can generate cylindricity deformation error jumping, so that in the matching of the valve core and the valve hole, the control gap amount between the valve core and the valve hole is not uniformly distributed along the circumference, the lubrication film is easy to damage, the valve core abrasion and the motion clamping stagnation interference are generated, and the problem is not effectively solved in the aspect of the hydraulic processing process.

Disclosure of Invention

The invention aims to provide a valve core of a hydraulic proportional valve and a surface texture processing technology thereof.

The technical purpose of the invention is realized by the following technical scheme:

a surface texture is arranged on a sealing surface between the valve core and a valve sleeve, the surface texture comprises a plurality of pits which are orderly arranged on the sealing surface of the valve core, the pits are pyramid structures, and pyramid tips are positioned at the bottoms of the pits.

By adopting the technical scheme, the surface texture consisting of the pits with the pyramid structures is arranged on the sealing surface of the valve core, the pits with the surface texture can store redundant lubricating oil, the lubricating oil can be supplemented in time without being added again when the sealing surface is needed, an oil film can be formed on the surface of the valve core quickly in the moving process of the valve core, the forming time of the oil film between the sealing surfaces is effectively shortened, and the problem of maintaining the working oil film of the valve core is solved. Meanwhile, the surface texture can also reduce the friction coefficient, reduce the friction wear, improve the dynamic pressure lubrication performance, reduce the dynamic interference of working liquid, prolong the service life and reliability of the valve core and ensure the working performance and working effect of the valve core. And the concave pit is arranged on the outer surface of the valve core, so that the actual contact area of the sealing surface between the valve core and the valve sleeve can be reduced, and the friction and the abrasion of the sealing surface are reduced. The pits are pyramid-shaped, and compared with a square or round pit, the structure of the pit is complex, so that the critical bearing capacity can be obviously improved, and the service life of the valve core is further prolonged.

Furthermore, the depth of each pit in the surface texture is 1-2 μm, the side length of the opening side is 75-120 μm, the distance between adjacent pits is 100-200 μm, and the area occupancy rate of the surface texture is 5-35%.

By adopting the technical scheme, researches show that the larger the side length and the distance of the side edges of the pits are, the better the wear resistance is, and the tribological performance of the pits under the conditions of deep cavities, low density and small openings is improved to the greatest extent. And when the depth, the side length and the distance of the opening side and the surface texture area occupancy of the pit are determined to be within the ranges by combining the actual use condition of the valve core, the wear-resisting effect, the use performance and the use effect of the valve core all reach better states.

Further, the surface texture is processed and formed by a numerical control machine tool press-rolling processing technology.

By adopting the technical scheme, the surface texture is formed on the valve core sealing surface by rolling through the numerical control machine tool rolling process, the numerical control machining can meet the forming requirement of the conventional valve core surface texture, and the valve core surface texture forming machine is safer, more environment-friendly and relatively lower in cost.

A surface texture processing technique of a valve core of a hydraulic proportional valve,

s1, designing a texture mould for manufacturing the surface texture; the surface of the texture mould is provided with a plurality of conical protrusions matched with the concave pits in the surface texture, the height of each conical protrusion is 1.2-2.5 mu m, the side length of the bottom edge is 90-145 mu m, and the distance between every two adjacent conical protrusions is 85-165 mu m;

s2, performing accurate grinding on the outer surface of the valve core; the surface roughness is controlled to be 1-1.5 mu m;

s3, performing surface texture processing on the outer surface of the valve core by using a numerical control machine tool and the texture mould; the valve core is positioned, rotated and installed on a numerical control machine tool, the texture mold is installed on one side of the valve core, the numerical control machine tool applies a load perpendicular to the valve core to the texture mold, and the texture mold enables a sealing surface of the valve core to generate deformation indentations in the rotating process of the valve core to form a surface texture;

s4, honing the outer surface of the valve core by using a three-dimensional air floatation clamp by using a numerical control honing machine; the geometric tolerance of the honing process meets the following requirements: the cylindricity is less than or equal to 0.5-1 μm, and the surface roughness RZ is 0.1-0.5 μm.

By adopting the technical scheme, firstly, the texture mould is designed according to the length and the outer diameter of the sealing surface of the surface texture required to be processed by the valve core, because the periphery of the concave pit can be extruded to expose the material shoulder ridge object during the press-rolling processing, the plane of the texture mould can not be completely attached to the sealing surface of the valve core, the height of the upper conical projection and the side length of the bottom edge of the texture mould are designed to be slightly larger than the height of the concave pit in the surface texture and the side length of the opening side, so that the concave pit which can be processed on the sealing surface of the valve core by the texture mould can meet the specification requirement. And secondly, performing accurate grinding on the surface of the valve core, controlling the surface roughness to be 1-1.5 mu m, and avoiding the influence of overlarge machining allowance on the depth of a pit in the surface texture while reserving certain machining allowance for honing machining after the surface texture machining is finished. And then, processing a surface texture on the surface of the valve core by using a numerical control machine tool and a designed texture die, positioning and rotatably installing the valve core on the numerical control machine tool, selecting the texture die matched with the length of the sealing surface of the valve core, installing the texture die on the numerical control machine tool and positioned on one side of the valve core, controlling the valve core to rotate by using the numerical control machine tool, simultaneously driving the texture die to abut against the sealing surface of the valve core and applying a load perpendicular to the valve core to the texture die, so that a deformed indentation is left on the sealing surface of the valve core by a conical protrusion on the texture die to form a pit in the rotating process of the valve core, and finally forming the surface texture on the sealing surface of the valve core. The depth of the formed pits and the side length of the opening side can be controlled by controlling the load applied to the texture die, the requirements of the pits with different specifications are met, and the consistency of the sizes of the pits is ensured. And finally, the numerical control honing machine is high in honing precision and convenient to operate, and the numerical control honing machine is used for honing the outer surface of the valve core by adopting a three-dimensional air floatation clamp, so that the geometric tolerance requirement is met.

Further, in S3, the rotation speed N of the valve core is 1000-.

By adopting the technical scheme, the proper rotating speed of the valve core is selected according to the outer diameter of the sealing surface of the surface texture to be processed by the valve core, the load applied to the texture mold by the numerical control machine tool is selected according to the size requirement of the pit in the surface texture to be processed by the valve core, the surface texture meeting the specification requirement is processed on the sealing surface of the valve core under the adjustment and matching action of the rotating speed of the valve core and the load borne by the texture mold, and the forming effect and the using effect of the surface texture are ensured.

Furthermore, a hardness tester is arranged on the numerical control machine tool and used for controlling the size of the load applied by the numerical control machine tool to the texture mould.

By adopting the technical scheme, the hardness meter arranged on the numerical control machine tool can accurately control the size of the load applied by the numerical control machine tool to the texture die, so that the precision of surface texture processing is effectively improved, the product percent of pass and the production efficiency are improved, and the production and processing cost is reduced.

Further, in S3, a lubricant is sprayed on the texture mold during the process, and the spraying flow q of the lubricant is 0.5-1L/min.

By adopting the technical scheme, in the process of machining the surface texture by matching the numerical control machine tool and the texture die and pressing and rolling, the lubricating agent is sprayed on the texture die, so that the abrasion of the texture die is reduced, the service life of the texture die is effectively prolonged, the quality of pits machined on the surface of the valve core can be prevented from being influenced by impurities adhered on the texture die, and the use effect of the texture die is ensured. The control of the lubricant spraying flow rate is to avoid the waste of the lubricant and reduce the cost while ensuring the use effect of the lubricant.

In conclusion, the invention has the following beneficial effects:

1. the surface texture comprising a plurality of orderly arranged pyramid structure pits is processed and formed on the sealing surface of the valve core by utilizing a numerical control machine tool press rolling processing technology, the forming time of an oil film between the sealing surfaces of the valve core is shortened, the problem of keeping the working oil film of the valve core is solved, the friction coefficient is reduced, the friction and wear are reduced, the dynamic pressure lubrication performance is improved, the dynamic interference of working liquid is reduced, the service life and the reliability of the valve core are improved, and the working performance and the working effect of the valve core are ensured;

2. the surface texture is processed by the numerical control machine tool and the texture die through press rolling, the modular tool combination can be used for processing the surface texture aiming at valve cores with different diameters, the process is simple, the application range is wide, the safety and the reliability are realized, the cost is lower, and the surface texture forming effect is good.

Drawings

FIG. 1 is a schematic structural diagram of a valve core of a hydraulic proportional valve;

FIG. 2 is an enlarged view of portion A of FIG. 1;

FIG. 3 is a flow chart of a process for texturing the surface of a valve element of a hydraulic proportional valve;

FIG. 4 is a schematic structural view of a texture mold;

FIG. 5 is an enlarged view of portion B of FIG. 4;

FIG. 6 is a schematic view of the installation state of a hydraulic proportional valve core on a numerically controlled machine tool for machining surface textures.

In the figure, 1, a valve core; 2. surface texturing; 21. a pit; 3. a numerical control machine tool; 31. a hardness meter; 4. a texture mould; 41. a base plate; 42. and (4) conical projection.

Detailed Description

The present invention will be described in further detail with reference to the following drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

A hydraulic proportional valve core is shown in figure 1, wherein a sealing surface matched with a valve sleeve is arranged on the outer surface of a valve core 1, a surface texture 2 formed by a numerical control machine 3 press-rolling processing technology is arranged on the sealing surface of the valve core 1, the surface texture 2 can reduce friction coefficient, reduce friction wear, improve dynamic pressure lubrication performance, reduce working fluid power interference, prolong the service life and reliability of the valve core 1, and ensure the working performance and working effect of the valve core 1. In this embodiment, the valve body 1 is cylindrical and one of the sealing surfaces is taken as an example.

As shown in fig. 1 and 2, the surface texture 2 includes a plurality of pits 21 orderly arranged on the sealing surface of the valve element 1, the pits 21 are of a quadrangular pyramid structure, and the pyramid tips of the pits 21 are located at the bottom of the pits, so that the length of the side of the opening at each position between the bottom of the pit 21 and the sealing surface of the valve element 1 is different, the critical bearing capacity is effectively improved, and the service life of the valve element 1 is further prolonged. The depth of each pit 21 in the surface texture 2 is 1-2 μm, the side length of the opening side is 75-120 μm, the distance between adjacent pits 21 is 100-200 μm, and the area occupancy rate of the surface texture 2 is 5-35%. In the present embodiment, the pits 21 have a depth of 2 μm, the sides of the open side are 100 μm, the pitch between adjacent pits 21 is 150 μm, and the area occupancy of the surface texture 2 is 20%.

A surface texture processing technology for a valve core of a hydraulic proportional valve is shown in figure 3 and comprises the following steps:

and S1, designing the texture mold 4 according to the length and the outer diameter of the sealing surface of the surface texture 2 to be processed by the valve core 1, and selecting a proper texture mold 4 and a numerical control machine 3 for use in the press rolling process. As shown in fig. 4 and 5, the texture mold 4 includes a bottom plate 41, and a plurality of protrusions 42 are disposed on a surface of one side of the bottom plate 41 and are matched with the recesses 21 of the surface texture 2. Because the periphery of the concave pit 21 can be extruded to expose a material shoulder ridge during the press rolling process, the bottom plate 41 can not be completely attached to the sealing surface of the valve core 1, the height of each conical protrusion 42 is designed to be 1.2-2.5 mu m, the side length of the bottom edge is designed to be 90-145 mu m, and the distance between the adjacent conical protrusions 42 is designed to be 85-165 mu m, so that the height and the side length of the bottom edge of each conical protrusion 42 are designed to be slightly larger than the height and the side length of the opening side of the concave pit 21 in the surface texture 2, so as to ensure that the concave pit 21 which can be processed on the sealing surface of the valve core 1 by the texture mold 4 meets the specification requirements. In the present embodiment, the height of the tapered protrusions 42 is 2.5 μm, the length of the bottom side is 125 μm, and the distance between adjacent tapered protrusions 42 is 125 μm.

And S2, performing accurate grinding on the outer surface of the valve core 1 by using an external grinding machine, controlling the surface roughness of the valve core 1 to be 1-1.5 mu m, and avoiding the influence of overlarge machining allowance on the depth of the pit 21 in the surface texture 2 while reserving certain machining allowance for the honing machining after the surface texture 2 is machined.

And S3, processing the surface texture 2 on the surface of the valve core 1 by using the numerical control machine tool 3 and the designed texture mould 4. As shown in fig. 6, the valve core 1 is positioned, rotationally mounted and horizontally arranged on the numerical control machine 3, and the texture mold 4 is mounted above the valve core 1, and the side provided with the conical protrusion 42 faces downwards; the numerical control machine tool 3 controls the valve core 1 to rotate, simultaneously drives the texture mold 4 to abut against the sealing surface of the valve core 1 and applies a load which is vertical to the valve core 1 downwards to the texture mold 4, so that in the rotating process of the valve core 1, the conical protrusions 42 on the texture mold 4 leave deformation indentations on the sealing surface of the valve core 1 to form concave pits 21, and finally, the surface texture 2 is formed on the sealing surface of the valve core 1.

As shown in fig. 6, a hardness tester 31 is provided on the numerical control machine 3 for controlling the load applied to the texture mold 4, so as to control the size and depth of the pits 21 on the surface of the valve core 1, meet the requirements of the pits 21 of different specifications, and ensure the uniformity of the sizes of the pits 21. In addition, the numerical control machine tool 3 controls the rotation speed N of the valve core 1 to be 1000-. In the rolling process, a lubricant is sprayed on the texture die 4, the spraying flow rate of the lubricant is controlled to be 0.5-1L/min, the lubricant is used for reducing the abrasion of the texture die 4, the service life of the texture die 4 is prolonged, and the forming quality of the pits 21 is ensured. In the present embodiment, the rotation speed of the valve core 1 is 2500r/min, the load F applied to the texture mold 4 is 120N, and the injection flow q of the lubricant is 0.5L/min.

S4, in the process that the valve core 1 is extruded by the conical protrusions 42 on the texture mold 4, the material shoulder ridges are exposed at the periphery of each concave pit 21, so that after the surface texture 2 is subjected to rolling processing, the outer surface of the valve core 1 is subjected to honing processing by a numerical control honing machine through a three-dimensional air floatation clamp, and the cylindricity and the surface roughness of the surface of the valve core 1 are ensured. Wherein, the geometric tolerance of honing processing meets the requirements that the cylindricity is less than or equal to 0.5-1 μm and the surface roughness RZ is 0.1-0.5 μm.

While the foregoing description shows and describes the preferred embodiments of the present invention, it is to be understood that the invention is not limited to the forms disclosed herein, but is not to be construed as excluding other embodiments and is capable of use in various other combinations, modifications, and environments and is capable of changes within the scope of the inventive concept as described herein, commensurate with the above teachings, or the skill or knowledge of the relevant art. And that modifications and variations may be effected by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.