CVJ ball end milling cutter

Abstract

The utility model belongs to the technical field of milling cutters, and particularly relates to a CVJ ball-end milling cutter which comprises a cutter body and a taper shank, one end face, back on to the taper shank, of the cutter body is a plane, and a plurality of first cutting blades and first chip grooves are mounted on the circumferential side face of the cutter body; the first cutting blade is provided with an arc-shaped cutting edge, the arc-shaped cutting edge comprises an arc-shaped finish machining edge part and an arc-shaped rough machining edge part, the arc-shaped rough machining edge part is tangent to the arc-shaped finish machining edge part, the curvature of the arc-shaped rough machining edge part is larger than that of the arc-shaped finish machining edge part, and the length of the arc-shaped finish machining edge part is larger than that of the arc-shaped rough machining edge part; the end, away from the arc rough machining blade part, of the arc finish machining blade part is the cutting end point position of the arc cutting blade, the cutting starting point position of the arc cutting blade is located on the arc rough machining blade part, and the end, away from the arc finish machining blade part, of the arc rough machining blade part is flush with the plane. The ball-end milling cutter is easier to manufacture, and more materials are saved.

Description

Technical Field

[0001] The utility model belongs to the technical field of milling cutters, in particular to a CVJ ball-end milling cutter. Background Art

[0002] Universal joint ball cages can transmit torque and have the characteristics of strong load-bearing capacity, compact structure, and easy disassembly and assembly. They are widely used in the automotive industry, especially in transmission systems with front engines and right front wheel drive. They are composed of a star sleeve and a cylindrical sleeve. The universal joint ball cage shell has a ball sliding groove for supporting the relative rolling of the ball on the star sleeve and the cylindrical sleeve. It is generally processed with a ball end milling cutter.

[0003] A Chinese patent application with application publication number CN113857541A discloses a ball-end milling cutter and a processing method thereof for processing a universal joint ball cage shell. The ball-end milling cutter structure disclosed in the patent mainly includes a cutter body and a cutter handle that are integrally connected. The cutter body is configured as a hemispherical shape as a whole, and the top of the cutter body is configured as a circular plane. The side surface of the cutter body is provided with four evenly arranged guide surfaces, and each guide surface is fixedly provided with a circular arc blade. The ball sliding groove is processed by rotating cutting of the four circular arc blades.

[0004] Judging from the above-mentioned disclosed ball-end milling cutter structure, the cutting edge of the arc-shaped blade is mostly a relatively long arc. Theoretically, it will be divided into two at a certain position of the cutting edge. The front end part is formed by rough machining, and the rear end part is formed by fine machining. The quality of the cutting edge of the rough-machined part does not need to be as high as the quality of the cutting edge of the fine-machined part. However, during actual machining, the cutting edge of an entire arc blade will be machined according to the requirements of the fine-machined blade. Therefore, the process is relatively complicated during the manufacturing process. Moreover, due to the long blade length, the effective blade length actually used is less than the entire blade length, which will cause some waste of material. Utility Model Content

[0005] The purpose of the utility model is to provide a CVJ ball end milling cutter to solve the technical problems that the existing ball end milling cutters are complicated to process and cause much material waste during use.

[0006] In order to solve the above problems, the CVJ ball end mill provided by the present invention adopts the following technical solutions:

[0007] The CVJ ball end milling cutter comprises an integrally connected cutter body and a tapered shank, the cutter body is hemispherical, and the end face of the cutter body facing away from the tapered shank is a plane, a plurality of first cutting blades are installed on the circumferential side face of the cutter body, and a first chip groove corresponding to the first cutting blade is provided; the first cutting blade has an arc-shaped cutting edge, and the arc-shaped cutting edge protrudes outward from the circumferential side face of the cutter body in the radial direction of the cutter body; the arc-shaped cutting edge comprises an arc-shaped finishing blade portion and an arc-shaped roughing blade portion, the arc-shaped roughing blade portion is tangent to the arc-shaped finishing blade portion, and the curvature of the arc-shaped roughing blade portion is greater than the curvature of the arc-shaped finishing blade portion, and the length of the arc-shaped finishing blade portion is greater than the length of the arc-shaped roughing blade portion; the end of the arc-shaped finishing blade portion away from the arc-shaped roughing blade portion is the cutting end position of the arc-shaped cutting edge, the cutting starting position of the arc-shaped cutting edge is located on the arc-shaped roughing blade portion, and the end of the arc-shaped roughing blade portion away from the arc-shaped finishing blade portion is flush with the plane.

[0008] The beneficial effects of the present invention are as follows: the arc-shaped cutting edge on the CVJ ball end milling cutter of the present invention is not a complete cutting edge, but is divided into two parts: an arc-shaped finishing edge portion and an arc-shaped roughing edge portion tangent thereto; the entire length of the arc-shaped finishing edge portion participates in the finishing process, and the cutting starting point of the arc-shaped cutting edge is located on the arc-shaped roughing edge portion, that is, at least a part of the length of the arc-shaped roughing edge portion also participates in the cutting operation; compared with the prior art, when processing the same workpiece, the effective use length of the arc-shaped cutting edge used in the present invention that participates in the cutting operation is shorter, processing is easier, and it also saves more materials; and the presence of the arc-shaped roughing edge portion enables the arc-shaped cutting edge to have a tip arc, thereby improving the anti-breakage ability of the arc-shaped roughing edge portion.

[0009] Furthermore, a first blade mounting groove is provided on the circumferential side surface of the cutter body at the position of each first cutting blade, and the first blade mounting groove is connected to the corresponding first chip removal groove; the first chip removal groove has a chip removal guide groove wall, and the first blade mounting groove has a blade fitting groove wall parallel to the chip removal guide groove wall, and in the radial direction of the cutter body, the blade fitting groove wall is located on the outside of the chip removal guide groove wall.

[0010] Beneficial effect: reducing the possibility of the first cutting blade being cracked due to stress after welding.

[0011] Furthermore, a second blade mounting groove and a second chip removal groove are provided on the circumferential side surface of the cutter body, and a second cutting blade is installed in the second blade mounting groove. The first cutting blade and the second cutting blade are evenly distributed in the circumferential direction of the cutter body; the structure of the second cutting blade is the same as that of the first cutting blade, and the length of the arc-shaped finishing edge portion on the second cutting blade is smaller than the length of the arc-shaped finishing edge portion on the first cutting blade.

[0012] Beneficial effect: The second cutting blade plays a role in enhancing the cutting effect, increasing the cutting efficiency, and prolonging the service life of the entire ball end mill.

[0013] Furthermore, the first blade mounting groove and the second blade mounting groove have the same structure and size, and the first chip removal groove and the second chip removal groove have the same structure and size.

[0014] Beneficial effect: Improve processing convenience.

[0015] Furthermore, there are four first cutting blades, and two second cutting blades, and the two second cutting blades are arranged in a central symmetrical manner about the central axis of the cutter body.

[0016] Beneficial effects: Reasonable layout and excellent cutting effect.

[0017] Furthermore, the tool body is provided with inclined front cutting edge cooling channels at positions corresponding to each first chip groove and each second chip groove, and the front cutting edge cooling channels extend to the corresponding chip guide groove wall to form a front cutting edge cooling medium outlet on the chip guide groove wall; the tool body is provided with inclined back cutting edge cooling channels at positions facing away from each first cutting blade and each second cutting blade, and the back cutting edge cooling channels extend to the circumferential side surface of the tool body to form a back cutting edge cooling medium outlet on the circumferential side surface of the tool body; main cooling channels that are interconnected are provided on the tool body and the tapered shank, and the main cooling channels, each front cutting edge cooling channels and each back cutting edge cooling channels are all connected, and the main cooling channels extend to the end of the tapered shank to form a cooling medium inlet at the end of the tapered shank.

[0018] Furthermore, the main cooling channel is coaxially arranged with the tapered shank, the rake face cooling channels are distributed in an array around the circumference of the main cooling channel, and the flank face cooling channels are distributed in an array around the circumference of the main cooling channel.

[0019] Beneficial effect: The cooling medium is uniformly discharged from the front and rear sides of each first cutting blade and each second cutting blade, thereby ensuring the normal operation of the first cutting blade and the second cutting blade.

[0020] Furthermore, a positioning hole is provided on the circumferential side surface of the cutter body.

[0021] Beneficial effect: It is convenient for positioning and installing the entire ball end milling cutter. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and other objects, features and advantages of the exemplary embodiments of the present invention will become readily understood by reading the detailed description below with reference to the accompanying drawings. In the accompanying drawings, several embodiments of the present invention are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0023] Figure 1 The three-dimensional structure of the CVJ ball end milling cutter of the utility model is shown in FIG. Figure 1 ;

[0024] Figure 2 The three-dimensional structure of the CVJ ball end milling cutter of the utility model is shown in FIG. Figure 2 ;

[0025] Figure 3 A top view of the CVJ ball end milling cutter of the present invention;

[0026] Figure 4 This is a bottom view of the CVJ ball end milling cutter of the present invention;

[0027] Figure 5 This is a front view of the CVJ ball end milling cutter of the present invention;

[0028] Figure 6 This is a schematic structural diagram of the cutter body of the CVJ ball end milling cutter of the present invention;

[0029] Figure 7 This is a schematic structural diagram of the first cutting blade of the CVJ ball end milling cutter of the present invention.

[0030] Description of reference numerals:

[0031] 1. Tool body; 2. Tapered shank; 3. First cutting blade; 4. Second cutting blade; 5. First chip groove; 6. Second chip groove; 7. First blade mounting groove; 8. Second blade mounting groove; 9. Chip guide groove wall; 10. Blade fitting groove wall; 11. Curved cutting edge; 12. Curved finishing edge; 13. Curved roughing edge; 14. Coolant outlet for rake face; 15. Coolant outlet for flank face; 16. Coolant inlet; 17. Positioning hole. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Those skilled in the art should know that the embodiments described below are part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0033] The principle and spirit of the present invention are explained in detail below with reference to several representative embodiments of the present invention.

[0034] Embodiment 1 of the CVJ ball end milling cutter provided by the present invention:

[0035] like Figure 1 、 Figure 2 and Figure 4 As shown, the CVJ ball end milling cutter includes a cutter body 1 and a tapered shank 2 that are integrally connected. The cutter body 1 is hemispherical as a whole, and one end surface of the cutter body 1 facing away from the tapered shank 2 is a plane.

[0036] like Figure 5 and Figure 6 As shown, four first blade mounting grooves 7, four first chip removal grooves 5, two second blade mounting grooves 8, and two second chip removal grooves 6 are installed on the circumferential side surface of the cutter body 1, wherein the first blade mounting groove 7 and the second blade mounting groove 8 have the same structure and size, and the first chip removal groove 5 and the second chip removal groove 6 have the same structure and size. The first blade mounting groove 7 is connected to the first chip removal groove 5, and the second blade mounting groove 8 is connected to the second chip removal groove 6. The first chip removal groove 5 and the second chip removal groove 6 both have a chip removal guide groove wall 9, and the first blade mounting groove 7 and the second blade mounting groove 8 both have a blade fitting groove wall 10 parallel to the chip removal guide groove wall 9. In the radial direction of the cutter body 1, the blade fitting groove wall 10 is located on the outside of the chip removal guide groove wall 9. Of course, in other embodiments, the blade fitting groove wall 10 may also be non-parallel to the chip removal guide groove wall 9.

[0037] A first cutting blade 3 is welded and mounted in each first blade mounting groove 7, and a second cutting blade 4 is welded and mounted in each second blade mounting groove 8. The two second cutting blades 4 are arranged centrally and symmetrically about the central axis of the cutter body 1. In this embodiment, the first cutting blade 3 and the second cutting blade 4 have the same structure and differ only in size.

[0038] The first cutting blade 3 and the second cutting blade 4 both have arc-shaped cutting edges 11, such as Figure 7As shown, the curved cutting edge 11 is made of PCBN. This embodiment is described using the curved cutting edge 11 on the first cutting blade 3 as an example. The curved cutting edge 11 protrudes radially outward from the circumferential side of the cutter body 1. The curved cutting edge 11 includes a curved finishing edge 12 and a curved roughing edge 13. Before machining, the boundary between the curved finishing edge 12 and the curved roughing edge 13 is calculated by calculating various parameters and simulating the machining process. The length of the curved finishing edge 12 is greater than that of the curved roughing edge 13, the curved roughing edge 13 is tangent to the curved finishing edge 12, and the curvature of the curved roughing edge 13 is greater than that of the curved finishing edge 12. The end of the arcuate finishing edge 12 remote from the arcuate roughing edge 13 is the cutting endpoint of the arcuate cutting edge 11. The cutting starting point of the arcuate cutting edge 11 is located on the arcuate roughing edge 13, close to the end of the cutter body 1 remote from the tapered shank 2. The end of the arcuate roughing edge 13 remote from the arcuate finishing edge 12 is flush with the corresponding end face of the cutter body 1. The length of the arcuate finishing edge 12 on the second cutting blade 4 is shorter than that on the first cutting blade 3. The second cutting blade 4 enhances the cutting effect, increases cutting efficiency, and improves the service life of the entire ball end mill.

[0039] The tool body 1 is provided with inclined rake face cooling channels at positions corresponding to each first chip flute 5 and each second chip flute 6. The rake face cooling channels extend to the corresponding chip guide groove wall 9 to form a rake face cooling medium outlet 14 on the chip guide groove wall 9. The tool body 1 is provided with inclined flank face cooling channels at positions facing away from the curved cutting edges 11 of each first cutting insert 3 and each second cutting insert 4. The flank face cooling channels extend to the circumferential side surface of the tool body 1 to form a flank face cooling medium outlet 15 on the circumferential side surface of the tool body 1. The tool body 1 and the tapered shank 2 are provided with main cooling channels that are interconnected. The main cooling channels are arranged coaxially with the tapered shank 2. The rake face cooling channels are distributed in an array around the circumference of the main cooling channels, and the flank face cooling channels are distributed in an array around the circumference of the main cooling channels. The main cooling channel, each front cutting edge cooling channel and each back cutting edge cooling channel are all connected, and the main cooling channel extends to the end of the tapered shank 2 to form a cooling medium inlet 16 at the end of the tapered shank 2. The cooling medium is gas in this embodiment. Of course, liquid can also be used in actual use. In other embodiments, the front cutting edge cooling channels may not be set at all the positions corresponding to the first chip grooves 5 and the second chip grooves 6 on the tool body 1, and the back cutting edge cooling channels may not be set at all the positions of the curved cutting edges 11 on the tool body 1 facing away from the first cutting blades 3 and the second cutting blades 4. The number of front cutting edge cooling channels and back cutting edge cooling channels can be reasonably set according to actual processing requirements.

[0040] Positioning holes 17 are also provided on the circumferential side surface of the cutter body 1 to facilitate the positioning and installation of the entire ball end milling cutter.

[0041] It should be noted that during actual processing, the number of the first cutting blades 3 and the second cutting blades 4 is limited to four and two in this application. The cutter body 1 can be reasonably processed according to actual needs, and a suitable number of first cutting blades 3 and second cutting blades 4 can be installed on the cutter body 1.

[0042] The curved cutting edge 11 of the CVJ ball-end milling cutter of the present invention is divided into two parts: a curved finishing edge 12 and a tangential curved roughing edge 13. The cutting edge of conventional ball-end milling cutters is a single, fully arcuate cutting edge. In the present invention, the entire length of the curved finishing edge 12 is used for finishing, while the starting point of the cutting of the curved cutting edge 11 is located on the curved roughing edge 13, close to the end face of the cutter body 1. This means that the majority of the length of the curved roughing edge 13 is involved in the cutting operation. Compared to conventional cutters, when machining the same workpiece, the effective length of the curved cutting edge 11 used in the present invention is shorter, meaning the entire length of the circular cutting edge is shorter. This makes machining easier and saves more material than conventional cutters. Furthermore, the presence of the curved roughing edge 13 imparts a rounded tip to the curved cutting edge 11, improving its resistance to chipping. The six cutting inserts also enhance the cutting performance and efficiency of the entire ball-end milling cutter.

[0043] Embodiment 2 of the CVJ ball end milling cutter provided by the present invention:

[0044] The main difference between it and Example 1 is that: in Example 1, for ease of processing, the structure and size of the first blade mounting groove and the second blade mounting groove are the same, and the structure and size of the first chip groove and the second chip groove are the same. In this embodiment, the first blade mounting groove and the second blade mounting groove have the same structure but different sizes, and the size of the second blade mounting groove matches the size of the second cutting blade; the first chip groove and the second chip groove have the same structure but different sizes, and the size of the second chip groove is designed and processed according to the cutting range of the second cutting blade. Of course, in other embodiments, the structure and size of the first blade mounting groove and the second blade mounting groove can also be different, and the structure and size of the first chip groove and the second chip groove can also be different, as long as the first cutting blade and the second cutting blade can be normally installed and normal chip removal is satisfied.

[0045] Embodiment 3 of the CVJ ball end milling cutter provided by the present invention:

[0046] The main difference between this embodiment and the first embodiment is that: in the first embodiment, a second cutting blade is provided to enhance the cutting effect and cutting efficiency. In this embodiment, no second cutting blade is provided and only the first cutting blade is provided.

[0047] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A CVJ ball-end milling cutter comprising an integrally connected cutter body and a tapered shank. The cutter body is hemispherical, with one end of the cutter body facing away from the tapered shank being flat. A plurality of first cutting inserts are mounted on the circumferential side of the cutter body, and first chip removal grooves are formed corresponding to the first cutting inserts. The first cutting inserts have arcuate cutting edges that protrude radially outward from the circumferential side of the cutter body. The cutter body is characterized in that: The arc-shaped cutting edge includes an arc-shaped finishing edge portion and an arc-shaped rough-cutting edge portion, the arc-shaped rough-cutting edge portion is tangent to the arc-shaped finishing edge portion, and the curvature of the arc-shaped rough-cutting edge portion is greater than the curvature of the arc-shaped finishing edge portion, and the length of the arc-shaped finishing edge portion is greater than the length of the arc-shaped rough-cutting edge portion; the end of the arc-shaped finishing edge portion away from the arc-shaped rough-cutting edge portion is the cutting end position of the arc-shaped cutting edge, the cutting starting position of the arc-shaped cutting edge is located on the arc-shaped rough-cutting edge portion, and the end of the arc-shaped rough-cutting edge portion away from the arc-shaped finishing edge portion is flush with the plane.

2. The CVJ ball end mill according to claim 1, characterized in that: A first blade mounting groove is provided on the circumferential side surface of the cutter body at the position of each first cutting blade, and the first blade mounting groove is connected to the corresponding first chip removal groove; the first chip removal groove has a chip removal guide groove wall, and the first blade mounting groove has a blade fitting groove wall parallel to the chip removal guide groove wall, and in the radial direction of the cutter body, the blade fitting groove wall is located on the outside of the chip removal guide groove wall.

3. The CVJ ball end mill according to claim 1, characterized in that: A second blade mounting groove and a second chip removal groove are also provided on the circumferential side surface of the cutter body, and a second cutting blade is installed in the second blade mounting groove. The first cutting blade and the second cutting blade are evenly distributed in the circumferential direction of the cutter body; the structure of the second cutting blade is the same as that of the first cutting blade, and the length of the arc-shaped finishing edge portion on the second cutting blade is less than the length of the arc-shaped finishing edge portion on the first cutting blade.

4. The CVJ ball end mill according to claim 3, characterized in that: The first blade installation slot and the second blade installation slot have the same structure and size, and the first chip removal slot and the second chip removal slot have the same structure and size.

5. The CVJ ball end mill according to claim 3 or 4, characterized in that: There are four first cutting blades and two second cutting blades, and the two second cutting blades are arranged in a central symmetrical manner with respect to the central axis of the cutter body.

6. The CVJ ball end mill according to claim 3 or 4, characterized in that: The tool body is provided with inclined rake face cooling channels at positions corresponding to each first chip groove and each second chip groove, and the rake face cooling channels extend to the corresponding chip guide groove wall to form a rake face cooling medium outlet on the chip guide groove wall; the tool body is provided with inclined flank face cooling channels at positions facing away from the arc-shaped cutting edges of each first cutting blade and each second cutting blade, and the flank face cooling channels extend to the circumferential side surfaces of the tool body to form a flank face cooling medium outlet on the circumferential side surfaces of the tool body; main cooling channels that are interconnected are provided on the tool body and the tapered shank, and the main cooling channels, each rake face cooling channel and each flank face cooling channel are all connected, and the main cooling channels extend to the end of the tapered shank to form a cooling medium inlet at the end of the tapered shank.

7. The CVJ ball end mill according to claim 6, characterized in that: The main cooling channel is coaxially arranged with the tapered shank, the rake face cooling channels are distributed in an array around the circumference of the main cooling channel, and the flank face cooling channels are distributed in an array around the circumference of the main cooling channel.

8. The CVJ ball end mill according to any one of claims 1 to 4, characterized in that: Positioning holes are also provided on the circumferential side surface of the cutter body.

Images