Machining method for normal bottom hole of pin bush of automobile testing fixture and automobile testing fixture

Abstract

The invention relates to a machining method for a pin bush normal bottom hole of an automobile testing fixture and the automobile testing fixture, and the machining method comprises the following steps: carrying out digital-analog processing based on three-dimensional modeling software, and converting a traditional rectangular model of the pin bush normal bottom hole into a split model, namely, additionally arranging a communicating gap region above a traditional rectangular region of the pin bush normal bottom hole, a traditional rectangular modeling structure is broken through, a notch area is designed to form a continuous open machining path, a three-axis machine tool can complete pin bush normal bottom hole forming at a time, complex multi-axis linkage is not needed, the equipment requirement is lowered, a ball-end milling cutter is adopted to be matched with the three-axis numerical control machine tool, the pin bush normal bottom hole is milled through the multi-direction cutting characteristic of the ball-end milling cutter, and the machining efficiency is improved. The spherical cutting edge can be attached to the normal curved surface, it is guaranteed that the axis of the normal bottom hole of the pin bush is consistent with the normal direction of the profile of the gauge, an open notch area is formed, residual materials in a rectangular area can be cleaned conveniently, the notch area is filled with resin, it is guaranteed that the hole position precision is not affected by follow-up treatment, and normal bottom hole machining of the normal pin bush is completed.

Description

Technical Field

[0001] The present application relates to the field of machining normal bottom holes of automobile inspection fixture pin sleeves, and in particular to a machining method for normal bottom holes of automobile inspection fixture pin sleeves and an automobile inspection fixture. Background Art

[0002] Automotive inspection fixtures are specialized tools designed for the automotive industry. They are used to inspect the size, shape, position, and functional parameters of automotive parts and complete vehicles to ensure they strictly comply with design requirements. They verify product conformity by quickly determining dimensional errors (such as hole position and surface deviation) between parts and design prototypes. The pin sleeve normal bottom hole is a prefabricated hole structure used to install positioning pin sleeves in automotive inspection fixtures. Its core function is to provide a precise positioning reference for the pin sleeve and ensure a stable fit between the inspection fixture and the part to be tested.

[0003] In the related art, the normal bottom hole of the pin sleeve on the automobile inspection fixture is usually processed by a five-axis machine tool. Although the processing accuracy of the normal hole can be guaranteed by the five-axis machine tool, the processing cost is relatively high and the cost performance is low. Summary of the Invention

[0004] The present application provides a method for processing the normal bottom hole of the pin sleeve of an automobile inspection fixture and an automobile inspection fixture, which can solve the technical problem that the normal bottom hole of the pin sleeve of a traditional automobile inspection fixture is processed using a five-axis machine tool, which has high processing costs and low cost-effectiveness.

[0005] In a first aspect, an embodiment of the present application provides a method for machining a normal bottom hole of a pin sleeve of an automobile inspection fixture, comprising the following steps:

[0006] The resin gauge is digitally modeled using 3D modeling software, and the pin sleeve normal bottom hole on the resin gauge is transformed from a rectangular shape to a split shape. The split shape has a split area connected to the original rectangular area of ​​the pin sleeve normal bottom hole.

[0007] Based on the open shape, the resin gauge surface is machined and formed using a three-axis CNC machine tool with a ball-end milling cutter. The residual material in the rectangular area is processed, and the pin sleeve is embedded in the processed rectangular area.

[0008] The open area is filled with resin to complete the normal bottom hole processing of the normal pin sleeve.

[0009] In combination with the first aspect, in one embodiment, the method of using three-dimensional modeling software to perform digital model processing on the resin gauge to transform the normal bottom hole of the pin sleeve on the resin gauge from a rectangular shape to a split shape includes:

[0010] Construct a cylinder that matches the outer contour of the pin sleeve;

[0011] Based on the cylinder, array translation and replication are performed along the X and Z axis directions with a preset step size to form a cylindrical array; wherein the cylindrical array includes cylindrical array unit 1, cylindrical array unit 2 and cylindrical array unit 3 in sequence along the X axis direction, the height of cylindrical array unit 1 along the X axis direction remains unchanged, the height of cylindrical array unit 2 along the X axis direction gradually decreases, and the height of cylindrical array unit 3 along the X axis direction gradually increases until the bottom end of the highest cylinder along the Z axis direction is higher than the resin gauge surface where the open area is located;

[0012] The cylinder array is merged into a solid through Boolean addition operation, and the solid is used to perform Boolean subtraction operation on the resin gauge to form a gap shape.

[0013] In combination with the first aspect, in one embodiment, the method of merging the cylindrical array into a solid body by a Boolean addition operation and performing a Boolean subtraction operation on the resin gauge using the solid body to form a gapped shape includes:

[0014] The cylinder array is merged into a solid through Boolean addition operation, and the Boolean subtraction operation is performed on the resin gauge using the solid. The edge of the cutout area is smoothed by a surface smoothing algorithm, so that the edge of the cutout area and the mold surface of the resin gauge form a continuous transition fillet structure, thus forming a cutout shape.

[0015] In combination with the first aspect, in one embodiment, the resin gauge surface is machined and formed based on the open shape using a three-axis CNC machine tool with a ball end milling cutter, residual material in the rectangular area is processed, and the pin sleeve is embedded in the processed rectangular area, including:

[0016] Based on the open shape, the resin gauge surface is machined and formed using a three-axis CNC machine tool with a ball-end milling cutter;

[0017] Use a scraper to manually remove the residual materials in the rectangular area;

[0018] Insert the pin sleeve into the processed rectangular area and keep the semicircular contact surface positioned.

[0019] In combination with the first aspect, in one embodiment, the process of machining the resin gauge surface based on the split-open model using a three-axis CNC machine tool in conjunction with a ball-end milling cutter includes:

[0020] Based on the cutout shape, the three-axis CNC machine tool automatically adjusts the milling depth of each layer according to the height gradient change of the cutout area along the Z axis, so that the axial load fluctuation amplitude of the ball end milling cutter is maintained within the preset threshold.

[0021] In combination with the first aspect, in one embodiment, the step of filling the open area with resin to complete the normal bottom hole processing of the normal pin sleeve includes:

[0022] Use paste-like resin to fill the gap area. After the paste-like resin solidifies, use a spatula to cut off the excess resin material, keeping it flush with the resin gauge surface, and completing the normal pin sleeve normal bottom hole processing.

[0023] In combination with the first aspect, in one embodiment, before using the three-dimensional modeling software to perform digital model processing on the resin gauge to convert the normal bottom hole of the pin sleeve on the resin gauge from a rectangular shape to a split shape, the method further includes:

[0024] Use screws and resin glue to connect the resin gauge to the base plate.

[0025] In combination with the first aspect, in one embodiment, after the resin is used to fill the open area and the normal bottom hole of the normal pin sleeve is processed, the method further includes:

[0026] The resin gauge is repeatedly processed by 3D modeling software, and the normal bottom hole of the pin sleeve on the resin gauge is transformed from a rectangular shape to an open shape. Based on the open shape, the resin gauge surface is processed and filled with resin using a three-axis CNC machine tool with a ball end milling cutter to complete the remaining normal pin sleeve normal bottom hole processing.

[0027] In combination with the first aspect, in one embodiment, after the resin is used to fill the open area and the normal bottom hole of the normal pin sleeve is processed, the method further includes:

[0028] The three-axis CNC machine tool is used to complete the Z-direction vertical bottom hole processing of the pin sleeve of the resin inspection fixture.

[0029] In a second aspect, an embodiment of the present application provides an automobile inspection fixture that implements the method for machining the normal bottom hole of the automobile inspection fixture pin sleeve as described in some of the above embodiments, comprising:

[0030] A resin gauge, wherein the resin gauge is provided with a pin sleeve normal bottom hole, the cross section of the pin sleeve normal bottom hole forming a rectangular area, and the resin gauge is further provided with an open groove, the open groove being located above the pin sleeve normal bottom hole and communicating with the pin sleeve normal bottom hole, the cross section of the open groove forming an open area;

[0031] A pin sleeve, the pin sleeve being embedded in the rectangular area;

[0032] Resin is filled in the open area.

[0033] The beneficial effects of the technical solutions provided in the embodiments of the present application include:

[0034] Based on the 3D modeling software, digital model processing is performed to transform the traditional rectangular shape of the pin sleeve normal bottom hole into an open shape, that is, a connected notch area is added above the traditional rectangular area of ​​the pin sleeve normal bottom hole. This design breaks the traditional rectangular shape structure, and the notch area design forms a continuous open processing path, so that the three-axis machine tool can complete the pin sleeve normal bottom hole forming at one time, without the need for complex multi-axis linkage, reducing equipment requirements, and adopting a ball end milling cutter in conjunction with a three-axis CNC machine tool. The multi-directional cutting characteristics of the ball end milling cutter are utilized to mill the pin sleeve normal bottom hole to ensure that the axis of the pin sleeve normal bottom hole is strictly consistent with the normal direction of the gauge surface, forming an open notch area to facilitate the cleaning of residual materials in the rectangular area. After processing is completed, the notch area is filled with resin. After curing, the resin and the resin gauge are seamlessly combined to ensure that the hole position accuracy is not affected by subsequent processing, that is, the normal pin sleeve normal bottom hole processing is completed. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0036] Figure 1 This is a schematic diagram of the three-dimensional structure of the resin gauge fixed to the base plate;

[0037] Figure 2 for Figure 1 A side structural diagram of

[0038] Figure 3 This is a schematic diagram of the distribution of the normal bottom holes and the Z-direction vertical bottom holes of the pin sleeve of the resin gauge;

[0039] Figure 4 This is a structural diagram of the resin gauge after digital model processing, in which the normal bottom hole of the pin sleeve is transformed from a rectangular shape to a split shape;

[0040] Figure 5 This is a schematic diagram of the path for processing resin gauges on a three-axis CNC machine tool;

[0041] Figure 6 This is a schematic diagram of the residual material in the rectangular area after the ball end mill is used to process the resin gauge;

[0042] Figure 7 This is a schematic diagram of positioning and installing the pin sleeve after processing the residual material in the rectangular area behind the resin gauge;

[0043] Figure 8 Schematic diagram of the cutout area of ​​the resin gauge for resin filling.

[0044] In the figure: 1. Base plate; 2. Resin gauge; 21. Normal bottom hole of pin sleeve; 22. Z-direction vertical bottom hole of pin sleeve; 23. Rectangular area; 24. Open area; 3. Pin gauge; 4. Pin sleeve; 5. Cylinder array; 6. Residual material; 7. Resin. DETAILED DESCRIPTION

[0045] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0046] It should be understood that automotive inspection fixtures are special tools designed for the automotive industry. They are used to detect the size, shape, position and functional parameters of automotive parts and complete vehicles to ensure that they strictly meet the design requirements. By quickly determining the dimensional errors between parts and design prototypes (such as hole position and surface deviation), the product is verified to be qualified. The pin sleeve normal bottom hole is a prefabricated hole structure used to install the positioning pin sleeve in the automotive inspection fixture. Its core function is to provide a precise positioning reference for the pin sleeve and ensure stable fit between the inspection fixture and the part to be tested.

[0047] Specifically, such as Figure 1 and Figure 2 As shown, the pin sleeve 4 and the resin gauge 2 are bonded with resin glue, and the pin gauge 3 is inserted into the pin sleeve 4 in a sliding fit relationship and used to position the parts or qualitatively detect whether the part hole position is qualified.

[0048] Among them, the normal bottom hole of the pin sleeve on the automobile inspection fixture is usually processed by a five-axis machine tool. Although the processing accuracy of the normal hole can be guaranteed by a five-axis machine tool, the processing cost is relatively high and the cost performance is low.

[0049] The embodiments of the present application provide a method for processing the normal bottom hole of the pin sleeve of an automobile inspection fixture and an automobile inspection fixture, which can solve the technical problem that the normal bottom hole of the pin sleeve of a traditional automobile inspection fixture is processed using a five-axis machine tool, which has high processing costs and low cost-effectiveness.

[0050] In a first aspect, an embodiment of the present application provides a method for machining a normal bottom hole 21 of a pin sleeve of an automobile inspection fixture, comprising the following steps:

[0051] S100: Figure 3 and Figure 4As shown, the resin gauge 2 is digitally modeled using 3D modeling software, and the pin sleeve normal bottom hole 21 on the resin gauge 2 is transformed from a rectangular shape to an open shape; wherein, the open shape is provided with an open area 24 connected to the original rectangular area 23 of the pin sleeve normal bottom hole 21;

[0052] S200: Figure 6 and Figure 7 As shown, based on the open shape, the resin gauge 2 is machined and formed using a three-axis CNC machine tool with a ball-end milling cutter, the residual material 6 in the rectangular area 23 is processed, and the pin sleeve 4 is embedded in the processed rectangular area 23;

[0053] S300: Figure 8 As shown, resin 7 is used to fill the open area 24 to complete the processing of the normal pin sleeve normal bottom hole 21.

[0054] In this embodiment, digital modeling is performed based on three-dimensional modeling software to transform the traditional rectangular shape of the pin sleeve normal bottom hole 21 into an open shape, that is, a connected notch area is added above the traditional rectangular area 23 of the pin sleeve normal bottom hole 21. This design breaks the traditional rectangular shape structure. The notch area design forms a continuous open processing path, so that the three-axis machine tool can complete the forming of the pin sleeve normal bottom hole 21 at one time, without the need for complex multi-axis linkage, reducing equipment requirements, and using a ball end milling cutter in conjunction with a three-axis CNC machine tool. The multi-directional cutting characteristics of the ball end milling cutter are utilized to mill the pin sleeve normal bottom hole 21. The spherical blade can be attached to the normal curved surface, ensuring that the axis of the pin sleeve normal bottom hole 21 is strictly consistent with the normal of the gauge surface, forming an open notch area to facilitate cleaning of the residual material 6 in the rectangular area 23; after processing, the notch area is filled with resin 7 of the same material as the resin gauge 2. After curing, the resin 7 is seamlessly combined with the resin gauge 2, and the shrinkage rate of the filled resin 7 matches that of the resin gauge 2, ensuring that the hole position accuracy is not affected by subsequent processing.

[0055] Specifically, when the pin sleeve 4 is installed on the resin gauge 2, as long as the position and diameter of the pin sleeve normal bottom hole 21 on the resin gauge 2 are accurate, the position of the pin sleeve 4 and the pin sleeve normal bottom hole 21 after press-fitting is also accurate. In fact, the pin sleeve 4 and the pin sleeve normal bottom hole 21 do not need to be press-fitted over the entire circumference. It is only necessary to ensure that the pin sleeve 4 and the pin sleeve normal bottom hole 21 have a half circumference area that is in contact (such as Figure 7As shown), the assembly position accuracy of the pin sleeve 4 can be guaranteed. We can open the normal bottom hole 21 of the pin sleeve upwards to transform the traditional rectangular shape into an open shape. In this way, the three-axis CNC milling machine can complete the one-time processing of the open open shape, which greatly reduces the processing cost. After the three-axis processing completes the open open shape, the pin sleeve 4 is assembled so that the pin sleeve 4 and the pin sleeve normal bottom hole 21 maintain a semi-circular fit. At the same time, the open area 24 is filled with resin 7 to complete the processing of the normal pin sleeve normal bottom hole 21.

[0056] In combination with the first aspect, in one embodiment, in S100, the following steps are included:

[0057] S100-1: Construct a cylinder that matches the outer contour of the pin sleeve 4;

[0058] S100-2: Figure 5 As shown, the cylinder is translated and replicated along the X and Z axis directions with a preset step size to form a cylindrical array 5; wherein, the cylindrical array 5 includes cylindrical array unit 1, cylindrical array unit 2 and cylindrical array unit 3 in sequence along the X axis direction, the height of cylindrical array unit 1 along the X axis direction remains unchanged, the height of cylindrical array unit 2 along the X axis direction gradually decreases, and the height of cylindrical array unit 3 along the X axis direction gradually increases until the bottom end of the highest cylinder along the Z axis direction is higher than the mold surface of the resin gauge 2 where the opening area 24 is located;

[0059] S100 - 3 : The cylindrical array 5 is merged into a solid through a Boolean addition operation, and a Boolean subtraction operation is performed on the resin gauge 2 using the solid to form a gap shape.

[0060] In this embodiment, the outer contour of the cylinder strictly matches the geometric parameters of the pin sleeve 4 to ensure that the open area 24 generated by the subsequent Boolean operation can accurately accommodate the pin sleeve 4. The geometric adaptation of the workpiece and the tool path is achieved through solid modeling. Three types of array units are set along the X axis (such as Figure 5 As shown in FIG, the constant height segment of the cylindrical array unit 1 serves as the machining reference surface to maintain cutting stability, the decreasing height segment of the cylindrical array unit 2 realizes the rectangular area 23, and the increasing height segment of the cylindrical array unit 3 forms the notch area; the discrete cylindrical array 5 is generated into a continuous entity through Boolean addition to form a tool path envelope that matches the notch shape. When the Boolean subtraction operation is performed, the intersection boundary of the entity array and the resin gauge 2 automatically generates a precise geometric boundary of the notch area 24.

[0061] In combination with the first aspect, in one embodiment, in S100-3, the following steps are included:

[0062] S100-3-1: The cylindrical array 5 is merged into a solid through a Boolean addition operation, and a Boolean subtraction operation is performed on the resin gauge 2 using the solid. The edge of the cutout area 24 is smoothed using a surface smoothing algorithm so that the edge of the cutout area 24 and the mold surface of the resin gauge 2 form a continuous transition fillet structure, thereby forming a cutout shape.

[0063] In this embodiment, the discrete cylindrical array 5 (as described in S200-2) is merged into a single entity through a Boolean addition (Union) operation to form a tool path envelope that matches the opening shape. This process is based on parametric modeling to ensure seamless connection between array units and avoid processing errors caused by discrete structures. The fused entity is used as a "virtual tool" to perform a Boolean subtraction (Subtract) operation on the resin gauge 2 to accurately cut out the opening area 24. The Boolean operation is directly based on CAD digital modeling operations to avoid dimensional deviations caused by factors such as tool wear and vibration in traditional processing. It is suitable for processing special-shaped notches (such as trapezoids, arcs, etc.) and is not restricted by the tool shape. The continuously transitioned chamfered corner structure can reduce the risk of stress concentration and extend the service life of the resin gauge 2.

[0064] In combination with the first aspect, in one embodiment, in S200, the following steps are included:

[0065] S200-1: Based on the open shape, the resin gauge 2 surface is machined and formed using a three-axis CNC machine tool with a ball-end milling cutter;

[0066] S200-2: manually removing the residual material 6 in the rectangular area 23 using a scraper;

[0067] S200-3: Embed the pin sleeve 4 into the processed rectangular area 23 and keep the semicircular contact surface positioned.

[0068] In this embodiment, by using a three-axis CNC machine tool in conjunction with a ball-end milling cutter (S200-1), the forming of the open shape can be efficiently achieved, ensuring that the geometric accuracy of the surface meets the design requirements. A manual scraper is used to remove the residual material 6 in the rectangular area 23 (S200-2). Supplementary processing is performed on the corners or small areas that are difficult for the CNC machine tool to completely clean, avoiding mechanical interference, improving surface quality, and reducing the cost complexity of fully automated processing. The pin sleeve 4 is embedded in the rectangular area 23 and maintained in the semicircular contact surface position (S200-3). The semicircular contact provides a stable radial constraint, which not only ensures positioning accuracy but also avoids the risk of over-positioning, facilitating the assembly and reuse of the inspection fixture. Combining CNC automation with manual intervention, balancing processing efficiency and detail processing requirements, it is particularly suitable for the inspection fixture processing of soft materials such as resin 7, reducing the risk of material deformation or damage. The use of a three-axis machine tool in conjunction with a simple tool (shovel) reduces equipment investment costs while ensuring accuracy.

[0069] In combination with the first aspect, in one embodiment, in S200-1, the following steps are included:

[0070] S200-1-1: Based on the cutout shape, the three-axis CNC machine tool automatically adjusts the milling depth of each layer according to the height gradient change of the cutout area 24 along the Z axis, so that the axial load fluctuation amplitude of the ball end mill is maintained within the preset threshold.

[0071] In this embodiment, the milling depth is calculated in real time and layered according to the Z-axis height gradient of the opening area 24, so that the axial cutting force fluctuation of the ball-end milling cutter is always lower than the preset threshold, avoiding instantaneous overload of the tool caused by sudden changes in the material removal amount, reducing the risk of chipping or wear, and significantly extending the tool life. The constraint of the load fluctuation amplitude can reduce the forced vibration of the machine tool-tool system, especially for the resin 7 with weaker rigidity, prevent surface vibration caused by cutting vibration, and ensure the surface finish. Materials such as resin 7 are sensitive to cutting force, and load fluctuations can easily cause burrs or tears. This solution directly protects the integrity of the material through threshold limiting, which is particularly suitable for scenarios with high surface quality requirements such as inspection tools.

[0072] In combination with the first aspect, in one embodiment, in S300, the following steps are included:

[0073] S300-1: Use a paste-like resin 7 to fill the open area 24. After the paste-like resin 7 is solidified, use a spatula to cut off the excess resin 7 to keep it flush with the molding surface of the resin gauge 2, and complete the processing of the normal pin sleeve normal bottom hole 21.

[0074] In this embodiment, a paste-like resin 7 is used to fill the open area 24. Its fluidity can fully fit the complex curved surface contour. After solidification, it forms a uniform combination with the original resin 7 matrix, avoiding stress concentration or matching deviation caused by rigid repair (such as metal inserts). After solidification, it is manually trimmed with a scraper to be flush with the molding surface, ensuring that the axial direction of the bottom hole is consistent with the normal reference, providing a precise positioning basis for the subsequent pin sleeve 4 assembly, and reducing the pin sleeve 4 overload caused by the inclination of the normal pin sleeve and the normal bottom hole 21; the process of paste resin 7 filling + manual scraping does not require secondary CNC processing, reducing the cost of high-precision machine tools.

[0075] In combination with the first aspect, in one embodiment, before S100, the following steps are included:

[0076] S000: Connect the resin gauge 2 to the base plate 1 using screws and resin glue.

[0077] In this embodiment, mechanical locking of the screws provides rigid constraints, and the resin glue is bonded to fill the microscopic gaps on the contact surface, forming a mechanical-chemical composite fixation, thereby avoiding micro-displacement of the resin gauge 2 and the base plate 1 during milling, ensuring the uniformity of the surface processing benchmark. The resin glue layer can absorb part of the high-frequency vibration transmitted by the machine tool, reducing damage to the surface of the soft resin 7 caused by cutting vibration (such as tool marks and chatter marks), and improving the surface finish. The base plate 1 is installed before the opening and shaping process (S100), and the rigidity of the base plate 1 is used to offset the bending stress of the resin gauge 2 during subsequent cutting. This is particularly suitable for thin-walled or large-span gauge structures, preventing cutting deformation caused by insufficient clamping force. The screws facilitate the subsequent disassembly and replacement of the resin gauge 2, and the resin glue can be heated, softened, and removed when necessary (such as epoxy resin thermal decomposition at 780-120°C), taking into account both process fixation requirements and maintenance convenience. The resin glue only covers the non-functional surface at the bottom of the resin gauge 2. The surface of the base plate 1 can be reused for new gauge assembly after cleaning, reducing tooling costs.

[0078] In combination with the first aspect, in one embodiment, after S300, the following steps are included:

[0079] S400: Repeatedly use the three-dimensional modeling software to perform digital model processing on the resin gauge 2, transform the pin sleeve normal bottom hole 21 on the resin gauge 2 from a rectangular shape to a split shape, and based on the split shape, use a three-axis CNC machine tool with a ball end milling cutter to perform the molding and resin 7 filling steps on the resin gauge 2 surface, completing the remaining normal pin sleeve normal bottom hole 21 processing.

[0080] In this embodiment, the process can be nested in loops to support additional processing of newly added holes. By simply inserting new features in the digital model, a new round of S100-S300 processes can be triggered to complete the processing of the remaining normal pin sleeve normal bottom holes 21.

[0081] In combination with the first aspect, in one embodiment, after S300, the following steps are included:

[0082] S500: Use a three-axis CNC machine tool to complete the processing of the Z-direction vertical bottom hole 22 of the pin sleeve of the resin inspection fixture 2.

[0083] In this embodiment, the normal bottom hole 21 of the normal pin sleeve and the Z-direction vertical bottom hole 22 of the pin sleeve are processed independently in separate steps to ensure that the positioning accuracy in each direction does not interfere with each other.

[0084] In combination with the first aspect, in one embodiment, the cross-section of the open area 24 is substantially a right triangle, a right-angled side of the right triangle coincides with a side of the rectangular area 23 , and the hypotenuse is parallel to the Z axis.

[0085] In this embodiment, the hypotenuse of the right triangle is parallel to the Z axis, so that the ball end milling cutter directly leaves the removable area 24 in the Z axis after processing, thereby reducing the milling path of the ball end milling cutter.

[0086] In summary, the following is a complete description of the processing method of the pin sleeve normal bottom hole 21 of the automobile inspection fixture:

[0087] First of all, it is important to understand that when the pin sleeve 4 is installed in the resin gauge 2, as long as the position and diameter of the pin sleeve normal bottom hole 21 on the resin gauge 2 are accurate, the position of the pin sleeve 4 and the pin sleeve normal bottom hole 21 after press-fitting will also be accurate. In fact, the pin sleeve 4 and the pin sleeve normal bottom hole 21 do not need to be press-fitted along the entire circumference, such as Figure 7 As shown, as long as the pin sleeve 4 and the pin sleeve normal bottom hole 21 are in contact over half of their circumference, the pin sleeve 4 can be assembled with high precision. The pin sleeve normal bottom hole 21 can be opened upward, creating an open area 24 above and connected to the original rectangular area 23. This allows the three-axis CNC milling machine to complete the opening process, significantly reducing processing costs.

[0088] After the three-axis machining completes the open shaping of the pin sleeve normal bottom hole 21, the pin sleeve 4 is assembled so that the pin sleeve 4 maintains half of the circumference in contact with the rectangular area 23. At the same time, the other half is filled with resin 7. After the resin 7 is cured, the excess resin 7 is scraped off with a spatula to keep it flush with the surrounding surface of the resin gauge 2. The surface accuracy requirement here is not high and the area is small, so manual scraping can meet the requirements.

[0089] That is, a method for processing the normal bottom hole 21 of the pin sleeve of an automobile inspection fixture, specifically comprising the following steps:

[0090] S1: First, the three-dimensional solid modeling of the resin gauge 2 is carried out, and the pin sleeve on the gauge resin 7 is shaped normal to the bottom hole 21 (see Figure 3 ) into an open, gaping shape (see Figure 4 ), the Z-direction vertical bottom hole 22 of the pin sleeve on the gauge resin 7 remains closed; wherein, there are several pin sleeve normal bottom holes 21 on the three-dimensional solid shape of the resin gauge 2, which are used to install the pin sleeve 4. The axis of the pin sleeve normal bottom hole 21 is consistent with the normal line of the curved surface where the hole is located. In order to enable the three-axis CNC milling machine to process the bottom hole of the pin sleeve 4 when processing the resin gauge 2 surface, it is necessary to open the pin sleeve normal bottom hole 21 along the Z axis. After opening, the pin sleeve normal bottom hole 21 has half of the circumference area fitted with the pin sleeve 4, and the remaining half of the circumference is opened (see Figure 4 );

[0091] Specific digital model processing method: 1) Use the outer contour of the pin sleeve 4 to make a solid cylinder; 2) Use the array translation copy method to make a series of cylinders; for example, along the Z axis direction, with a step distance of 0.02mm, translate and copy 1000 cylinders so that the lowest point of the cylinder highest in the Z direction is higher than the surface where the pin sleeve normal bottom hole 21 is located. If the lowest point of the cylinder highest in the Z direction is lower than the surface where the pin sleeve normal bottom hole 21 is located, increase the number of translation copies, for example, from 1000 translation copies to 1500, until the lowest point of the cylinder highest in the Z direction is higher than the surface where the pin sleeve normal bottom hole 21 is located; 3) Use Boolean addition operation to add this series of cylinders into a solid; 4) Use the solid as the tool body and the resin gauge 2 as the cut body, use Boolean subtraction operation to dig out the volume overlapping with the solid S1 on the resin gauge 2 to complete the modeling of the open pin sleeve normal bottom hole 21 (see Figure 5 ).

[0092] S2: According to the open shape, the three-axis CNC machine tool and the ball end cutter are used to process the surface and bottom hole of the resin gauge 2. When processing the rectangular area 23, a ball end cutter with a smaller diameter can be used. For example, the diameter of the ball end cutter is 3mm. The CNC machining path is from top to bottom, then the horizontal step is selected as 0.2, and then from bottom to top, reciprocating machining. Due to the use of the ball end cutter, there is a little residual material 6 at the bottom of the pin sleeve normal bottom hole 21 (see Figure 6 );

[0093] S3: Use a scraper to manually remove the residues from CNC machining;

[0094] S4: Install the pin sleeve 4 at the corresponding pin sleeve normal bottom hole 21, so that the pin sleeve 4 and the bottom hole keep half of the circumference area in contact (see Figure 7 ), to achieve the purpose of positioning, and at the same time use the paste-like resin 7 to stick the other half firmly (see Figure 8 ).

[0095] S5: After the paste-like resin 7 is solidified, use a spatula to cut off the excess resin 7 to keep it flush with the surrounding molding surface.

[0096] S6: The other normal pin sleeve normal bottom holes 21 on the resin gauge 2 are processed in the same manner.

[0097] In a second aspect, an embodiment of the present application provides an automobile inspection tool for processing a normal bottom hole of an automobile inspection tool pin sleeve as described in some of the above embodiments, comprising: a resin inspection tool 2, the resin inspection tool 2 having a pin sleeve normal bottom hole 21, the cross-section of the pin sleeve normal bottom hole 21 forming a rectangular area 23, the resin inspection tool 2 also having an open groove, the open groove being located above the pin sleeve normal bottom hole 21 and connected to the pin sleeve normal bottom hole 21, the cross-section of the open groove forming an open area 24; a pin sleeve 4, the pin sleeve 4 being embedded in the rectangular area 23; and a resin 7, the resin 7 being filled in the open area 24.

[0098] In this embodiment, when the pin sleeve 4 is installed on the resin gauge 2, as long as the position and diameter of the pin sleeve normal bottom hole 21 on the resin gauge 2 are accurate, the position of the pin sleeve 4 and the pin sleeve normal bottom hole 21 after press-fitting is also accurate. In fact, the pin sleeve 4 and the pin sleeve normal bottom hole 21 do not need to be press-fitted over the entire circumference. It is only necessary to ensure that the pin sleeve 4 and the pin sleeve normal bottom hole 21 have a half circumference area that is in contact (such as Figure 7 As shown), the assembly position accuracy of the pin sleeve 4 can be guaranteed. We can open the normal bottom hole 21 of the pin sleeve upwards to transform the traditional rectangular shape into an open shape. In this way, the three-axis CNC milling machine can complete the one-time processing of the open open shape, which greatly reduces the processing cost. After the three-axis processing completes the open open shape, the pin sleeve 4 is assembled so that the pin sleeve 4 and the pin sleeve normal bottom hole 21 maintain a semi-circular fit. At the same time, the open area 24 is filled with resin 7 to complete the processing of the normal pin sleeve normal bottom hole 21.

[0099] In the description of this application, it should be noted that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0100] It should be noted that, in this application, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0101] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. A method for processing the normal bottom hole of a pin sleeve of an automobile inspection fixture, characterized in that: It includes the following steps: The resin gauge is digitally modeled using 3D modeling software, and the pin sleeve normal bottom hole on the resin gauge is transformed from a rectangular shape to a split shape. The split shape has a split area connected to the original rectangular area of ​​the pin sleeve normal bottom hole. Based on the open shape, the resin gauge surface is machined and formed using a three-axis CNC machine tool with a ball-end milling cutter. The residual material in the rectangular area is processed, and the pin sleeve is embedded in the processed rectangular area. The open area is filled with resin to complete the normal bottom hole processing of the normal pin sleeve.

2. The method for processing the normal bottom hole of the automobile inspection tool pin sleeve according to claim 1, characterized in that: The resin fixture is digitally modeled using 3D modeling software to transform the normal bottom hole of the pin sleeve on the resin fixture from a rectangular shape to a split shape, including: Construct a cylinder that matches the outer contour of the pin sleeve; Based on the cylinder, array translation and replication are performed along the X and Z axis directions with a preset step size to form a cylindrical array; wherein the cylindrical array includes cylindrical array unit 1, cylindrical array unit 2 and cylindrical array unit 3 in sequence along the X axis direction, the height of cylindrical array unit 1 along the X axis direction remains unchanged, the height of cylindrical array unit 2 along the X axis direction gradually decreases, and the height of cylindrical array unit 3 along the X axis direction gradually increases until the bottom end of the highest cylinder along the Z axis direction is higher than the resin gauge surface where the open area is located; The cylinder array is merged into a solid through Boolean addition operation, and the solid is used to perform Boolean subtraction operation on the resin gauge to form a gap shape.

3. The method for processing the normal bottom hole of the automobile inspection tool pin sleeve according to claim 2, characterized in that: The method of merging the cylinder array into a solid by Boolean addition operation and performing Boolean subtraction operation on the resin gauge using the solid to form a gap shape includes: The cylinder array is merged into a solid through Boolean addition operation, and the Boolean subtraction operation is performed on the resin gauge using the solid. The edge of the cutout area is smoothed by a surface smoothing algorithm, so that the edge of the cutout area and the mold surface of the resin gauge form a continuous transition fillet structure, thus forming a cutout shape.

4. The method for processing the normal bottom hole of the automobile inspection tool pin sleeve according to claim 1, characterized in that: Based on the open shape, the resin gauge surface is processed and formed by using a three-axis CNC machine tool with a ball end milling cutter, the residual material in the rectangular area is processed, and the pin sleeve is embedded in the processed rectangular area, including: Based on the open shape, the resin gauge surface is machined and formed using a three-axis CNC machine tool with a ball-end milling cutter; Use a scraper to manually remove the residual materials in the rectangular area; Insert the pin sleeve into the processed rectangular area and keep the semicircular contact surface positioned.

5. The method for processing the normal bottom hole of the automobile inspection tool pin sleeve according to claim 4, characterized in that: The resin gauge surface is processed and formed based on the open shape by using a three-axis CNC machine tool and a ball-end milling cutter, including: Based on the cutout shape, the three-axis CNC machine tool automatically adjusts the milling depth of each layer according to the height gradient change of the cutout area along the Z axis, so that the axial load fluctuation amplitude of the ball end milling cutter is maintained within the preset threshold.

6. The method for processing the normal bottom hole of the automobile inspection tool pin sleeve according to claim 1, characterized in that: The method of filling the open area with resin to complete the normal bottom hole processing of the normal pin sleeve includes: Use paste-like resin to fill the gap area. After the paste-like resin solidifies, use a spatula to cut off the excess resin material, keeping it flush with the resin gauge surface, and completing the normal pin sleeve normal bottom hole processing.

7. The method for processing the normal bottom hole of the automobile inspection tool pin sleeve according to claim 1, characterized in that: Before the resin inspection tool is digitally modeled using 3D modeling software to transform the normal bottom hole of the pin sleeve on the resin inspection tool from a rectangular shape to a split shape, the method further includes: Use screws and resin glue to connect the resin gauge to the base plate.

8. The method for processing the normal bottom hole of the automobile inspection tool pin sleeve according to claim 1, characterized in that: After the resin is used to fill the open area and the normal bottom hole of the normal pin sleeve is processed, the method further includes: The resin gauge is repeatedly processed by 3D modeling software, and the normal bottom hole of the pin sleeve on the resin gauge is transformed from a rectangular shape to an open shape. Based on the open shape, the resin gauge surface is processed and filled with resin using a three-axis CNC machine tool with a ball end milling cutter to complete the remaining normal pin sleeve normal bottom hole processing.

9. The method for processing the normal bottom hole of the automobile inspection tool pin sleeve according to claim 1, characterized in that: After the resin is used to fill the open area and the normal bottom hole of the normal pin sleeve is processed, the method further includes: The three-axis CNC machine tool is used to complete the Z-direction vertical bottom hole processing of the pin sleeve of the resin inspection fixture.

10. An automobile inspection tool implementing the method for machining the normal bottom hole of the automobile inspection tool pin sleeve according to any one of claims 1 to 9, characterized in that: It includes: A resin gauge, wherein the resin gauge is provided with a pin sleeve normal bottom hole, the cross section of the pin sleeve normal bottom hole forming a rectangular area, and the resin gauge is further provided with an open groove, the open groove being located above the pin sleeve normal bottom hole and communicating with the pin sleeve normal bottom hole, the cross section of the open groove forming an open area; A pin sleeve, the pin sleeve being embedded in the rectangular area; Resin is filled in the open area.

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