High-precision machining clamp for crescent mainboard of internal gear pump

Abstract

The utility model discloses a high-precision internal gear pump crescent mainboard machining clamp, and relates to the field of machining clamps, the machining clamp comprises a positioning base, a position positioner and a pushing and pressing assembly, and the position positioner is rigidly connected with the positioning base through at least two guide columns; the high part of the positioning base is provided with a positioning bulge which is positioned and mounted on a working table of a machine tool; the top of the position positioner is provided with an arc positioning datum plane matched with a clamped workpiece and a vertical positioning datum plane. The arc positioning datum plane is matched with the outer contour of a workpiece, a clamping groove is formed in the corner of the bottom end of the vertical positioning datum plane, and the geometric contour of the groove is matched with the edge feature of the workpiece to form mechanical limiting. According to the machining clamp, a positioning guide system and a flexible clamping mechanism which are matched with the structural characteristics of the crescent mainboard are designed, standard unification and stress equalization of multi-procedure machining can be achieved, and the problem of precision loss caused by repeated clamping can be effectively solved.

Description

Technical Field

[0001] This application relates to the field of machining fixtures, and in particular to a high-precision machining fixture for a crescent-shaped mainboard of an internal meshing gear pump. Background Technology

[0002] In the field of hydraulic transmission, the performance of the internal gear pump, as a core power component, directly depends on the machining accuracy of the key component, the crescent-shaped main body. Currently, the industry commonly uses wire EDM or machining center sequential machining to manufacture the crescent-shaped main body. While wire EDM can achieve the forming of complex contours, its processing principle limits the formation of microscopic defects on the machined surface, making it difficult for the surface quality of the parts to meet high-precision fitting requirements. When machining features such as inner diameters, sides, and thicknesses in stages, the lack of a dedicated clamping system in machining centers necessitates multiple disassembly and reassembly adjustments of the machining datum. This not only results in low processing efficiency but also causes workpiece deformation due to repeated positioning errors and clamping stress, severely affecting the geometric accuracy of the crescent-shaped main body. This series of machining defects directly leads to problems such as uneven gear meshing clearance and reduced oil film carrying capacity, ultimately affecting the output pressure stability and service life of the gear pump.

[0003] The shortcomings of existing machining processes are mainly reflected in insufficient coordination of the process system and a lack of process stability. During wire EDM, the vibration of the electrode wire and the effect of the cooling medium easily form irregular textures on the workpiece surface. These microscopic defects can become wear initiation points under the scouring of high-pressure oil. When machining centers use general-purpose fixtures for multi-process machining, the lack of optimized positioning design for the crescent-shaped mainboard structure requires frequent changes in clamping position when the workpiece is processed in different sequences, resulting in inconsistent machining datum. More importantly, traditional clamping methods are difficult to evenly distribute clamping force when machining thin-walled structures, causing elastic deformation of the workpiece under the coupled action of cutting force and clamping force, further aggravating deviations in dimensional accuracy and geometric tolerances. These process defects, when transmitted to the end product, will significantly reduce the volumetric efficiency and pressure holding capacity of the gear pump, while shortening the effective service life of key components.

[0004] Developing new specialized fixtures to address the systemic shortcomings of existing processing technologies is of great value in improving the industry's technological level. Utility Model Content

[0005] The purpose of this application is to overcome at least one deficiency of the prior art and to provide a high-precision internal meshing gear pump crescent motherboard machining fixture.

[0006] To achieve the above objectives, this application discloses a high-precision internal meshing gear pump crescent motherboard machining fixture, which includes a positioning base, a position locator, and a pushing assembly, wherein the position locator is rigidly connected to the positioning base through at least two guide pillars.

[0007] The bottom of the positioning base is provided with a positioning protrusion for positioning and installation onto the machine tool worktable.

[0008] The top of the positioner is provided with an arc-shaped positioning reference surface adapted to the workpiece being clamped and a vertical positioning reference surface; the arc-shaped positioning reference surface matches the outer contour of the workpiece, and the bottom corner of the vertical positioning reference surface is provided with a locking groove, the geometric contour of which matches the edge features of the workpiece to form a mechanical limit.

[0009] The position locator forms a mounting position by horizontally recessing from the arc positioning reference surface, and the mounting position is used to install the pushing component.

[0010] The pushing assembly consists of a pushing block, an adjusting bolt, and an elastic preload mechanism located in the mounting position. The elastic preload mechanism includes a guide rod and a spring sleeved on the guide rod. The guide rod and the adjusting bolt are inserted into the pushing block from one side of the position locator and connected to the pushing block. When the adjusting bolt rotates, it drives the pushing block to move linearly. The preload force of the spring assists in the clamping and holding of the pushing block.

[0011] The front end of the push block is provided with a second positioning protrusion. The second positioning protrusion of the push block extends out of the arc positioning reference surface and into the groove on the surface of the workpiece, so that the push block and the vertical positioning reference surface cooperate to form a clamping in both horizontal and vertical directions.

[0012] When the workpiece is clamped, its bottom edge is embedded in the locking groove, its side wall is in contact with the vertical positioning reference surface, and its outer diameter is in close contact with the arc positioning reference surface, forming a three-level positioning constraint chain. Finally, the clamping force is applied to form a form-position coupling constraint, realizing a four-level positioning constraint.

[0013] Compared with existing technologies, this machining fixture is designed with a positioning and guiding system and a flexible clamping mechanism that are adapted to the structural features of the crescent-shaped motherboard. It can achieve the standardization of reference and stress equalization in multi-process machining, and effectively solve the problem of accuracy loss caused by repeated clamping.

[0014] The beneficial effects listed above are not exhaustive of all advantages. Other potential beneficial effects and detailed technical implementation methods will be further disclosed in the embodiments or other descriptive sections of this application. Attached Figure Description

[0015] A better understanding of various aspects of this disclosure will be achieved by reading the following detailed description in conjunction with the accompanying drawings. The positions, dimensions, and extents of the structures shown in the drawings, etc., do not always represent actual positions, dimensions, and extents. In the drawings:

[0016] Figure 1 This is a schematic diagram of the structure of one embodiment disclosed in this application.

[0017] Figure 2This is a schematic diagram of the structure of one embodiment disclosed in this application from another perspective.

[0018] Figure 3 yes Figure 2 Enlarged view of point A in the image.

[0019] Figure 4 This is a schematic diagram of the structure of an embodiment disclosed in this application in which the pushing component and the workpiece are clamped together.

[0020] Figure 5 This is a schematic diagram of the structure of an embodiment of the present application in the working state of the pushing component.

[0021] Figure 6 yes Figure 5 Enlarged view of point B in the image.

[0022] The labels in the diagram are as follows: Positioning base-1, Positioning locator-2, Pushing assembly-3, Workpiece-4, Positioning protrusion one-101, Circular positioning reference surface-201, Vertical positioning reference surface-202, Locking groove-203, Mounting position-204, Pushing block-301, Adjusting bolt-302, Guide rod-303, Spring-304, Positioning protrusion two-305. Detailed Implementation

[0023] The present disclosure will now be described with reference to the accompanying drawings, which illustrate several embodiments of the present disclosure. However, it should be understood that the present disclosure can be presented in many different ways and is not limited to the embodiments described below; in fact, the embodiments described below are intended to make the disclosure more complete and to fully illustrate the scope of protection of the present disclosure to those skilled in the art. It should also be understood that the embodiments disclosed herein can be combined in various ways to provide further additional embodiments.

[0024] It should be understood that the same reference numerals denote the same elements in all the accompanying drawings. For clarity, the dimensions of certain features may be modified in the drawings.

[0025] It should be understood that the terminology used in this specification is for describing specific embodiments only and is not intended to limit this disclosure. All terms used in this specification (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. For the sake of brevity and / or clarity, techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail; however, where appropriate, such techniques, methods, and apparatus should be considered part of this specification.

[0026] Unless otherwise specified, the singular forms “a,” “the,” and “the” used in this specification include the plural forms. The terms “comprising,” “including,” and “containing” used in this specification indicate the presence of the claimed feature but do not exclude the presence of one or more other features. The term “and / or” used in this specification includes any and all combinations of one or more of the relevant listed items.

[0027] See attached document Figures 1 to 6 The machining fixture in this embodiment includes a positioning base 1, a position locator 2, and a pushing assembly 3.

[0028] In this embodiment, the positioning base 1, serving as the fundamental support component of the entire fixture, is cast from high-strength cast iron using a precision casting technique well-known to those skilled in the art, ensuring the dimensional and shape accuracy of the positioning base. The bottom of the positioning base 1 is provided with a positioning protrusion 101 for positioning and mounting with the machine tool worktable.

[0029] The bottom of the positioning base 1 is provided with a positioning protrusion 101 for positioning and mounting onto the machine tool worktable. The shape of the positioning protrusion 101 is adapted to the corresponding positioning structure of the machine tool worktable. The specific adaptation method is well known to those skilled in the art and will not be described in detail here. Through this high-precision positioning, the installation position of the fixture on the machine tool can be ensured to be accurate, providing a stable reference for subsequent machining.

[0030] Specifically, the positioner 2 is rigidly connected to the positioning base 1 via at least two guide pillars. The guide pillars are made of precision-machined alloy steel, and the machining processes include turning and grinding to ensure high hardness and high straightness. The specific machining steps are well known to those skilled in the art. The connection methods between the guide pillars, the positioning base, and the positioner are all existing technologies and will not be described in detail here. This connection method can effectively ensure the relative positional accuracy and motion accuracy between the positioner 2 and the positioning base 1, ensuring that the positioner 2 will not shift or wobble during the use of the fixture, thereby affecting the clamping accuracy of the workpiece.

[0031] In this embodiment, the top of the positioner 2 is designed with an arc-shaped positioning reference surface 201 that matches the outer contour of the clamped workpiece 4, and a vertical positioning reference surface 202. The arc-shaped positioning reference surface 201 is machined using precision milling and grinding processes to ensure a high-precision fit with the outer arc contour of the workpiece. The specific machining parameters and process control are well known to those skilled in the art.

[0032] The vertical positioning reference surface 202 is precision-machined to ensure its perpendicularity and surface roughness, and the machining method is existing technology. At the bottom corner of the vertical positioning reference surface 202, there is a locking groove 203. The geometric contour of the locking groove 203 is precisely designed to match the characteristic shape of the edge of the workpiece 4, forming a mechanical limiting structure.

[0033] The slot groove 203 can be machined using methods such as electrical discharge machining to ensure its shape and position accuracy. The specific machining process parameters are well known to those skilled in the art and will not be described in detail here.

[0034] This multi-point, multi-faceted positioning method can effectively eliminate the various degrees of freedom of the workpiece during the clamping process, ensuring that the clamping position accuracy of the workpiece reaches the micrometer level.

[0035] Furthermore, a mounting position 204 is formed by a horizontal recess from the arc-shaped positioning reference surface 201. This mounting position 204 is used to install the pushing assembly 3. The pushing assembly 3 mainly consists of a pushing block 301, an adjusting bolt 302, and an elastic preload mechanism. The elastic preload mechanism includes a guide rod 303 and a spring 304 sleeved on the guide rod 303. The guide rod 303 and the adjusting bolt 301 are inserted from one side of the position locator 2 and reliably connected to the pushing block 301. It should be noted that the adjusting bolt 301 is threaded into the position locator 2.

[0036] It should be understood that the material of the push block 301 is high-strength alloy steel, which is heat-treated to improve its hardness and wear resistance. The specific heat treatment process is well known to those skilled in the art.

[0037] The machining of the adjusting bolt 302 includes turning, milling, and grinding processes to ensure its accuracy and surface quality; the specific machining steps are existing technology. When the adjusting bolt 302 rotates, it drives the pressing block 301 to move in a linear direction, thereby clamping or releasing the workpiece 4. Simultaneously, the preload of the spring 304 assists the pressing block 301 in maintaining a stable clamping force during the clamping process, ensuring that the workpiece 4 remains firmly clamped throughout the entire machining process and does not loosen due to changes in cutting force or other external interference factors, thus guaranteeing the consistency and stability of machining accuracy.

[0038] It should be noted that the selection of spring 304 and the setting of preload are techniques well known to those skilled in the art, and will not be described in detail here.

[0039] Furthermore, in the specific structure, the front end of the push block 301 is designed with a positioning protrusion 305. The shape and size of the positioning protrusion 305 are designed according to the specific requirements of the groove on the surface of the workpiece 4 to ensure that it can accurately extend into the groove on the surface of the workpiece 4. The positioning protrusion 305 is machined using precision milling and grinding processes to ensure its dimensional and shape accuracy. The specific machining method is existing technology.

[0040] Specifically, when the push block 301 moves forward under the drive of the adjusting bolt 302, its positioning protrusion 305 extends out of the arc-shaped positioning reference surface 201 and accurately enters the pre-designed groove on the surface of the workpiece 4. In this way, the push block 201 and the vertical positioning reference surface 202 cooperate with each other to form a two-way clamping of the workpiece 4 in the horizontal and vertical directions, further enhancing the clamping stability of the workpiece and enabling the workpiece to withstand greater cutting forces during processing, thus meeting the requirements of high-precision machining.

[0041] In the actual clamping process of workpiece 4, the crescent-shaped mainboard workpiece 4 is first placed on the position locator 2, so that its bottom edge is accurately embedded in the locking groove 203, achieving preliminary axial positioning. At the same time, the side wall of workpiece 4 is tightly attached to the vertical positioning reference surface 202, and the outer diameter is precisely attached to the arc positioning reference surface 201, forming a three-level positioning constraint chain. This multi-point, multi-face positioning method can effectively eliminate the various degrees of freedom of the workpiece during the clamping process, ensuring a high accuracy of the clamping position of workpiece 4. Finally, by rotating the adjusting bolt 302, the pushing block 301 is moved forward, applying a clamping force to workpiece 4, forming a form-position coupling constraint, thereby achieving a four-level positioning constraint, further improving the clamping stability and machining accuracy of workpiece 4.

[0042] This fixture has demonstrated significant advantages in practical applications, particularly in the machining of crescent-shaped mainboards for high-precision internal gear pumps. Compared to traditional clamping methods, it not only greatly improves workpiece clamping efficiency and reduces clamping time, but also effectively ensures workpiece machining accuracy and increases product yield. For example, when machining a batch of crescent-shaped mainboards, using this fixture significantly shortens the clamping time compared to traditional fixtures. Furthermore, the finished workpiece inspection results show that its dimensional accuracy and geometric tolerances remain consistently within the design requirements, effectively meeting the machining quality requirements of the core components of high-precision gear pumps and providing a strong guarantee for improving the overall performance and reliability of the gear pump.

[0043] While exemplary embodiments of this disclosure have been described, those skilled in the art will understand that various changes and modifications can be made to the exemplary embodiments of this disclosure without departing from the spirit and scope thereof. Therefore, all changes and modifications are included within the scope of protection of this disclosure as defined by the claims. This disclosure is defined by the appended claims, and equivalents of those claims are also included.

Claims

1. A high-precision inner meshing gear pump crescent main plate processing clamp, characterized in that, The machining fixture includes a positioning base, a position locator, and a pushing assembly, wherein the position locator is rigidly connected to the positioning base through at least two guide pillars; The bottom of the positioning base is provided with a positioning protrusion for positioning and installation onto the machine tool worktable. The top of the positioner is provided with an arc-shaped positioning reference surface adapted to the workpiece being clamped and a vertical positioning reference surface; the arc-shaped positioning reference surface matches the outer contour of the workpiece, and the bottom corner of the vertical positioning reference surface is provided with a locking groove, the geometric contour of which matches the edge features of the workpiece to form a mechanical limit. The position locator forms a mounting position by horizontally recessing from the arc positioning reference surface, and the mounting position is used to install the pushing component. The pushing assembly consists of a pushing block, an adjusting bolt, and an elastic preload mechanism located in the mounting position. The elastic preload mechanism includes a guide rod and a spring sleeved on the guide rod. The guide rod and the adjusting bolt are inserted into the pushing block from one side of the position locator and connected to the pushing block. When the adjusting bolt rotates, it drives the pushing block to move linearly. The preload force of the spring assists in the clamping and holding of the pushing block. The front end of the push block is provided with a second positioning protrusion. The second positioning protrusion of the push block extends out of the arc positioning reference surface and into the groove on the surface of the workpiece, so that the push block and the vertical positioning reference surface cooperate to form a clamping in both horizontal and vertical directions.

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