A special-shaped cutting tool for synchronous machining of the end face of an electric motor housing

Abstract

This invention relates to the field of machine tool technology, and in particular to a non-standard cutting tool for synchronous machining of the end face of a motor housing. The tool includes a tool holder body and a cutting insert detachably connected to the tool holder body. The tool holder body includes a coaxially arranged clamping section and a non-standard cutting section. A first radial expansion stage is provided at the connection between the clamping section and the non-standard cutting section, and a second radial expansion stage is provided at the end of the non-standard cutting section away from the first radial expansion stage. A first cutting insert positioning recess and a second cutting insert positioning recess are respectively formed on the first and second radial expansion stages. A first inclined tool holder is formed on the first cutting insert positioning recess, and a second inclined tool holder is formed on the second cutting insert positioning recess. This non-standard cutting tool achieves integrated machining of the motor housing's base surface and hole structure, enabling multi-feature machining without tool changes, effectively avoiding positioning deviations caused by multiple tool changes, thereby improving machining accuracy and consistency.

Description

Technical Field

[0001] This invention relates to the field of machine tool processing technology, and in particular to a special-shaped cutting tool for synchronous machining of the end face of an electric motor housing. Background Technology

[0002] The machining of motor housings for new energy vehicles has stringent requirements for precision and efficiency. The base holes and bearing holes must ensure high coaxiality and low radial runout, while the non-hole structures such as the base surface on the housing must also meet high-precision machining requirements.

[0003] Existing technologies have developed integrated cutting tools for machining dual holes in motor housings. These tools use coaxially arranged front and rear tool holders with two inserts to achieve single-clamp machining of the base hole and bearing hole, which improves the coaxiality of hole machining to some extent. However, the structural design of these tools has obvious limitations: they only have two coaxial tool holders and tool grooves distributed on the same plane, which can only be used for axial cutting of hole structures and cannot meet the axial feed end face cutting requirements of the motor housing base surface; the clearance structure of the tool holder is only a single machining groove, and the cooling channel only cools the two hole machining inserts, resulting in poor structural adaptability and making it impossible to achieve integrated machining of the motor housing base surface and hole structure.

[0004] To achieve high-precision machining of the multi-feature motor housing, the existing machining method requires changing different tools to machine the base surface and hole structure separately. Multiple tool changes not only increase machining time, but also easily cause positioning deviations due to tool changes, leading to the accumulation of machining errors, making it difficult to meet the high-precision machining requirements of the motor housing. At the same time, multiple clamping will also reduce machining efficiency and increase production and manufacturing costs. Summary of the Invention

[0005] In order to address the technical deficiencies mentioned in the background art, the purpose of this invention is to provide a special-shaped cutting tool for synchronous machining of the end face of a motor housing, aiming to solve the problems of existing cutting tools being unable to achieve integrated machining of the basic surface and hole system of the motor housing, poor structural adaptability, and easy accumulation of machining errors.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A non-standard cutting tool for synchronous machining of the end face of an motor housing includes a tool holder body and a cutting blade detachably connected to the tool holder body. The tool holder body includes a clamping section and a non-standard cutting section arranged coaxially. A first radial expansion stage is provided at the connection between the clamping section and the non-standard cutting section. A second radial expansion stage is provided at the end of the non-standard cutting section away from the first radial expansion stage. The diameter of the first radial expansion stage is smaller than the diameter of the second radial expansion stage. A first cutting blade positioning recess and a second cutting blade positioning recess are respectively formed on the first and second radial expansion stages. A first inclined tool holder is formed on the first cutting blade positioning recess. The first inclined tool holder is inclined relative to the axis of the tool holder body towards the direction of the second radial expansion stage. A second inclined tool holder is formed on the second cutting blade positioning recess. The second inclined tool holder is inclined relative to the axis of the tool holder body towards the direction of the first radial expansion stage.

[0007] Preferably, the first radial expansion stage and the second radial expansion stage are tapered transition structures, and the angle between the tapered surface and the axis of the tool holder body is 15° to 30°.

[0008] Preferably, the bottom surfaces of the first blade positioning recess and the second blade positioning recess are planes and perpendicular to the axis of the blade holder body.

[0009] Preferably, the first inclined tool holder and the second inclined tool holder are offset from each other in the circumferential direction of the tool holder body, and the angle between the first inclined tool holder, the second inclined tool holder and the axis of the tool holder body is 45° to 60°.

[0010] Preferably, both the first and second inclined tool holders have through screw fixing holes at their bottoms, and the axis of the screw fixing holes is perpendicular to the mounting plane of the corresponding tool holders.

[0011] Preferably, the blade has a rhomboid structure, and a mounting hole is provided at the position of the screw fixing hole; the blade is threadedly connected to the screw fixing hole by a fixing screw.

[0012] Preferably, the blade includes a first blade and a second blade. The first blade is used to machine the bearing hole reference surface of the motor housing and is installed in a first inclined tool holder. The second blade is used to machine the base hole reference surface of the motor housing and is installed in a second inclined tool holder.

[0013] Preferably, the clamping section and the irregular cutting section are respectively provided with arc-shaped clearance grooves at the positions of the first radial expansion platform and the second radial expansion platform.

[0014] Preferably, the clamping section and the irregular cutting section are provided with a cooling channel that runs through the axis of the tool holder body, and the arc-shaped clearance groove is provided with a liquid outlet hole that communicates with the cooling channel.

[0015] Preferably, the outer peripheral surface of the clamping section is provided with multiple clamping planes, which are distributed around the circumference of the clamping section and extend along the axial direction of the tool holder body, and the length of the clamping plane is consistent with the axial length of the clamping section.

[0016] In summary, the beneficial effects of the present invention are as follows: 1. This invention, by setting a first radial expansion stage and a second radial expansion stage, and setting a first blade positioning recess and a second blade positioning recess on the two expansion stages respectively, enables the first blade and the second blade to simultaneously process the bearing hole reference surface and the base hole reference surface of the motor housing, respectively. This achieves integrated processing of the motor housing base surface and the hole system structure, and can complete multi-feature processing without tool changing. It effectively avoids positioning deviation caused by multiple tool changes, significantly reduces the accumulation of processing errors, and improves processing accuracy and consistency.

[0017] 2. The present invention provides a first inclined tool holder and a second inclined tool holder with opposite inclination directions and circumferentially offset on the first and second tool holder positioning recesses, thereby forming an asymmetrical cutting layout for the first and second tool holders. This avoids the cutting interference problem caused by the coplanar arrangement of the two tool holders. At the same time, the inclined tool holders allow the tool holders to form a reasonable cutting angle during the cutting process, optimize the distribution of cutting force, reduce cutting vibration, and improve cutting stability and surface finish. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the irregular-shaped cutting tool of the present invention; Figure 2 This is an exploded view of the irregular-shaped cutting tool of the present invention; Figure 3 This is a top view of the irregular-shaped cutting tool of the present invention; Figure 4 yes Figure 3 A cross-sectional view of the AA plane; Figure 5 This is a diagram showing the working state of the special-shaped cutting tool used in this invention for machining the motor housing.

[0019] Explanation of the reference numerals in the figure: 1. Tool holder body; 11. Clamping section; 111. Clamping plane; 12. Irregular cutting section; 2. Tool insert; 21. First tool insert; 22. Second tool insert; 23. Mounting hole; 3. First radial expansion platform; 4. Second radial expansion platform; 5. First tool insert positioning recess; 51. First inclined tool holder; 6. Second tool insert positioning recess; 61. Second inclined tool holder; 7. Screw fixing hole; 8. Arc-shaped clearance groove; 9. Cooling channel; 10. Liquid outlet. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0021] Those skilled in the art should understand that, in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting this invention.

[0022] In the description of this invention, the use of terms such as "a number" means one or more, with "more than" meaning two or more. Terms like "greater than," "less than," and "exceeding" are understood to exclude the stated number, while terms like "above," "below," and "within" are understood to include the stated number. The use of terms like "first," "second," and "third" is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, the number of indicated technical features, or the sequential relationship between indicated technical features.

[0023] The following is in conjunction with the appendix Figure 1-5 The present invention will provide a more detailed description of an embodiment of a non-standard cutting tool for synchronous machining of the end face of an electric motor housing.

[0024] A special-shaped cutting tool for synchronous machining of the end face of an electric motor housing, such as Figure 1 , 2 As shown, the tool holder body 1 and the cutting blade 2 are included. The tool holder body 1 is made of high-strength alloy steel to ensure structural rigidity and vibration resistance during high-speed cutting. The cutting blade 2 is detachably connected to the tool holder body 1, which is convenient for replacement according to the wear of the machining process and reduces the cost of use.

[0025] In this embodiment, as Figure 2As shown, the tool holder body 1 includes a clamping section 11 and a non-circular cutting section 12 arranged coaxially. The clamping section 11 is used to cooperate with the machine tool spindle to clamp and position the tool, and the non-circular cutting section 12 is used to install the insert 2 and perform cutting. A first radial expansion platform 3 is provided at the connection between the clamping section 11 and the non-circular cutting section 12, and a second radial expansion platform 4 is provided at the end of the non-circular cutting section 12 away from the first radial expansion platform 3. The diameter of the first radial expansion platform 3 is smaller than the diameter of the second radial expansion platform 4. The two expansion platforms form a stepped structure, corresponding to machining features of different diameters on the motor housing.

[0026] Furthermore, the clamping section 11 and the irregular cutting section 12 of the tool holder body 1 adopt an integrated structure, formed by precision forging and CNC machining, ensuring the coaxiality and positional accuracy of each functional part. The end of the clamping section 11 is provided with a chamfered guide structure to facilitate quick docking with the machine tool spindle; the end of the irregular cutting section 12 is provided with a central positioning hole for axial positioning reference during tool pre-adjustment. The outer cylindrical surfaces of the first radial expansion table 3 and the second radial expansion table 4 are precision ground, with the surface roughness Ra controlled below 0.8μm, which can serve as auxiliary support surfaces during the machining process to improve the cutting stability of the tool.

[0027] In this embodiment, four clamping planes 111 are provided on the outer peripheral surface of the clamping section 11. The four clamping planes 111 are evenly distributed around the circumference of the clamping section 11 and extend along the axial direction of the tool holder body 1. The length of the clamping planes 111 is consistent with the axial length of the clamping section 11.

[0028] Furthermore, the clamping plane 111 cooperates with the hydraulic chuck or spring chuck of the machine tool spindle to achieve circumferential positioning and torque transmission of the tool. At the same time, the planar structure prevents the tool from rotating circumferentially during the cutting process, ensuring the stability of machining accuracy.

[0029] In this embodiment, as Figure 1-3 As shown, a first insert positioning recess 5 and a second insert positioning recess 6 are respectively provided on the first radial expansion platform 3 and the second radial expansion platform 4. A first inclined tool holder 51 is provided on the first insert positioning recess 5. The first inclined tool holder 51 is inclined relative to the axis of the tool holder body 1 and is arranged in the direction of the second radial expansion platform 4. The inclination angle is set according to the machining requirements of the bearing hole reference surface, so that the first insert 21 forms a reasonable rake angle and clearance angle during cutting. A second inclined tool holder 61 is provided on the second insert positioning recess 6. The second inclined tool holder 61 is inclined relative to the axis of the tool holder body 1 and is arranged in the direction of the first radial expansion platform 3, and is in the opposite direction to the inclination of the first inclined tool holder 51.

[0030] Furthermore, the first radial expansion platform 3 and the second radial expansion platform 4 are tapered transition structures. The angle between the tapered surface and the axis of the tool holder body 1 is preferably 30°. This tapered angle range has been optimized to ensure a strong transition between the expansion platform and the adjacent shaft section, while also providing sufficient clearance for the internal cavity structure of the motor housing, thus avoiding interference between the tool and the non-machined parts of the workpiece. The bottom surfaces of the two positioning recesses are both flat and perpendicular to the axis of the tool holder body 1. This perpendicular arrangement ensures that the cutting plane after the blade is installed remains parallel to the end face of the motor housing, thereby ensuring the flatness accuracy of the base surface machining. Among them, the first inclined tool holder 51 and the second inclined tool holder 61 are staggered by 90° in the circumferential direction of the tool holder body 1. This staggered arrangement avoids motion interference between the two blades during the cutting process, while also ensuring that the cutting force is evenly distributed in the circumferential direction of the tool holder body 1, reducing cutting vibration. The angle between the first inclined tool holder 51, the second inclined tool holder 61 and the axis of the tool holder body 1 is preferably 60°. This inclination angle allows the blade to form a larger actual working rake angle during the cutting process, which is conducive to the smooth discharge of chips, reduces cutting force and cutting temperature. At the same time, the inclined tool holders give the blade 2 better cutting performance, reduce the impact load during end face cutting, and improve the tool life and machining surface quality.

[0031] It should be noted that the tilt angles of the first inclined tool holder 51 and the second inclined tool holder 61 can be optimized according to the characteristics of the material being processed. For motor housings made of aluminum alloy, a smaller tilt angle can be selected to increase the cutting rake angle and improve cutting smoothness; for motor housings made of cast iron, a larger tilt angle can be selected to enhance the strength of the cutting edge and adapt to intermittent cutting conditions.

[0032] In this embodiment, as Figure 1-3 As shown, both the first inclined tool holder 51 and the second inclined tool holder 61 have through screw fixing holes 7 at their bottoms. The axis of the screw fixing holes 7 is perpendicular to the mounting plane of the corresponding tool holder. This vertical arrangement allows the tightening force of the fixing screw to act directly on the back of the blade 2, ensuring the stability of the blade 2 installation.

[0033] In this embodiment, as Figure 1-3 As shown, the cutting tool 2 includes a first cutting tool 21 and a second cutting tool 22. The first cutting tool 21 is installed in the first inclined tool holder 51 and is used to machine the bearing hole reference surface of the motor housing. The second cutting tool 22 is installed in the second inclined tool holder 61 and is used to machine the base hole reference surface of the motor housing. The two cutting tools are arranged asymmetrically in both the axial and circumferential directions, so that the tool can complete the synchronous machining of two base surfaces at different positions in one feed.

[0034] Furthermore, both the first blade 21 and the second blade 22 are diamond-shaped carbide blades, and the first blade 21 and the second blade 22 are respectively provided with mounting holes 23 at the positions corresponding to the screw fixing holes 7. The first blade 21 and the second blade 22 are threadedly connected to the screw fixing holes 7 by fixing screws to realize quick blade replacement and precise positioning.

[0035] It should be noted that the non-standard cutting tool in this embodiment can be adapted to the specific specifications and dimensions of the motor housing in practical applications. When machining different models of motor housings, only the first cutting tool 21 and the second cutting tool 22 of the corresponding specifications need to be replaced, and the cutting parameters of the machine tool need to be adjusted. There is no need to replace the entire tool holder body 1, which reduces the cost of using the cutting tool.

[0036] In this embodiment, as Figure 1-3 As shown, the clamping section 11 and the irregular cutting section 12 are respectively provided with arc-shaped relief grooves 8 at the positions of the first radial expansion platform 3 and the second radial expansion platform 4. The radius of curvature of the arc-shaped relief grooves 8 is designed according to the inner cavity contour of the motor housing, so that when the tool is processed deep inside the motor housing, the tool holder body 1 and the inner wall of the workpiece maintain a safe gap.

[0037] To prevent the cutting tool from overheating during machining and cutting, thus affecting the tool's lifespan, in this embodiment, as follows: Figure 1 , 4 As shown, the clamping section 11 and the irregular cutting section 12 are provided with a cooling channel 9 that runs through the axis of the tool holder body 1. The entrance of the cooling channel 9 is located at the center of the end face of the clamping section 11 and is connected to the machine tool's coolant supply system.

[0038] Furthermore, a coolant outlet 10, connected to the cooling channel 9, is provided on the arc-shaped clearance groove 8. The diameter of the outlet 10 is 2mm to 3mm, and the outlet direction is towards the cutting edge of the blade 2, ensuring that the coolant can be directly sprayed onto the cutting area, effectively reducing the cutting temperature and flushing away the chips. This cooling structure design enables simultaneous cooling of both blades, solving the problem of insufficient cooling coverage in existing tools.

[0039] To further verify the technical effects of this invention, a comparative experiment was conducted using the irregularly shaped cutting tool of this embodiment and an existing step-by-step machining scheme. The test object was the housing of a drive motor of a certain type of new energy vehicle, made of ADC12 aluminum alloy. The diameter of the bearing hole reference surface was φ80mm, the diameter of the base hole reference surface was φ60mm, and the axial distance between the two reference surfaces was 45mm. Using the irregularly shaped cutting tool of this invention, the spindle speed was 3500r / min, the feed rate was 800mm / min, and the machining of both reference surfaces was completed in a single feed, with a machining time of 12 seconds. The measured coaxiality of the bearing hole reference surface and the base hole reference surface was 0.008mm, and the surface roughness Ra was 0.6μm. Using the traditional step-by-step machining scheme, two end mills were used for machining, and two clamping and positioning operations were performed. The total machining time was 28 seconds, the measured coaxiality was 0.035mm, and the surface roughness Ra was 1.6μm. The comparative results show that the irregularly shaped cutting tool of this invention has significant advantages in terms of machining efficiency, positional accuracy, and surface quality.

[0040] like Figure 5 As shown, the working principle of the irregular-shaped cutting tool in this embodiment is as follows: First, the tool is clamped to the machine spindle via clamping section 11. The cutting parameters of the first insert 21 and the second insert 22 are adjusted so that the cutting edges of the two inserts are aligned with the machining positions of the bearing hole reference surface and the base hole reference surface of the motor housing, respectively. The machine spindle is started and coolant is supplied. The tool is fed axially at the set speed and feed rate. The first insert 21 and the second insert 22 simultaneously cut their respective machining surfaces, completing the integrated machining of the two basic surfaces of the motor housing. During the machining process, coolant is continuously sprayed into the cutting area through cooling channel 9 and outlet hole 10 to ensure the stability of the cutting state. Since the two basic surfaces are completed simultaneously in one clamping, the positioning error caused by multiple tool changes is eliminated. The coaxiality of the bearing hole reference surface and the base hole reference surface can reach within 0.01mm, and the surface roughness Ra can reach below 0.8μm, significantly improving the machining accuracy and production efficiency of the motor housing.

[0041] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. A special-shaped cutting tool for synchronous machining of the end face of an electric motor housing, comprising a tool holder body and a cutting blade detachably connected to the tool holder body, characterized in that, The tool holder body includes a clamping section and a non-circular cutting section arranged coaxially. A first radial expansion platform is provided at the connection between the clamping section and the non-circular cutting section. A second radial expansion platform is provided at the end of the non-circular cutting section away from the first radial expansion platform. The diameter of the first radial expansion platform is smaller than the diameter of the second radial expansion platform. A first insert positioning recess and a second insert positioning recess are respectively formed on the first and second radial expansion platforms. A first inclined tool holder is formed on the first insert positioning recess. The first inclined tool holder is inclined relative to the axis of the tool holder body towards the direction of the second radial expansion platform. A second inclined tool holder is formed on the second insert positioning recess. The second inclined tool holder is inclined relative to the axis of the tool holder body towards the direction of the first radial expansion platform.

2. The irregular-shaped cutting tool for synchronous machining of the end face of a motor housing according to claim 1, characterized in that, The first and second radial expansion platforms are tapered transition structures, and the angle between the tapered surface and the axis of the tool holder body is 15° to 30°.

3. The irregular-shaped cutting tool for synchronous machining of the end face of a motor housing according to claim 1, characterized in that, The bottom surfaces of the first and second blade positioning recesses are flat and perpendicular to the axis of the blade holder body.

4. The irregular-shaped cutting tool for synchronous machining of the end face of a motor housing according to claim 1, characterized in that, The first and second inclined tool holders are offset from each other in the circumferential direction of the tool holder body, and the angle between the first and second inclined tool holders and the axis of the tool holder body is 45° to 60°.

5. The irregular-shaped cutting tool for synchronous machining of the end face of a motor housing according to claim 1, characterized in that, Both the first and second inclined tool holders have through screw fixing holes at their bottoms, and the axis of the screw fixing holes is perpendicular to the mounting plane of the corresponding tool holders.

6. The irregular-shaped cutting tool for synchronous machining of the end face of a motor housing according to claim 5, characterized in that, The blade has a rhomboid structure, and a mounting hole is provided at the position of the screw fixing hole; the blade is threadedly connected to the screw fixing hole by a fixing screw.

7. The irregular-shaped cutting tool for synchronous machining of the end face of a motor housing according to claim 6, characterized in that, The blade includes a first blade and a second blade. The first blade is used to machine the bearing hole reference surface of the motor housing and is installed in a first inclined tool holder. The second blade is used to machine the base hole reference surface of the motor housing and is installed in a second inclined tool holder.

8. The irregular-shaped cutting tool for synchronous machining of the end face of a motor housing according to claim 1, characterized in that, The clamping section and the irregular cutting section are respectively provided with arc-shaped clearance grooves at the positions of the first radial expansion platform and the second radial expansion platform.

9. The irregular-shaped cutting tool for synchronous machining of the end face of a motor housing according to claim 8, characterized in that, The clamping section and the irregular cutting section are provided with cooling channels that run through the axis of the tool holder body, and the arc-shaped clearance groove is provided with a liquid outlet hole that communicates with the cooling channels.

10. The irregular-shaped cutting tool for synchronous machining of the end face of a motor housing according to claim 1, characterized in that, The outer circumferential surface of the clamping section is provided with multiple clamping planes. The multiple clamping planes are distributed around the circumference of the clamping section and extend along the axial direction of the tool holder body, and the length of the clamping plane is consistent with the axial length of the clamping section.

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