A method for rounding the spline surface with self-positioning angular spline

Abstract

The present invention discloses a method for rounding a spline profile with angular self-positioning, comprising the following steps: S1, providing a keyway on a gear shaping cutter, wherein the keyway has an angular relationship consistent with any tooth of the gear shaping cutter, and designing a matching key on a gear shaping cutter arbor so that the gear shaping cutter has an angular relationship consistent with a machine tool; designing a fixture with a locating pin to fix a part on a CNC machining center; S2, processing at least one locating hole on the part; S3, using a forming column milling cutter that matches the rounding size of the spline profile to round the spline profile; the present invention saves tooling costs and greatly shortens the time required to align the spline angular position before rounding the spline profile.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical processing, in particular to a method for processing a spline profile rounding with angular self-positioning of the spline. Background Art

[0002] Spline connection is a common mechanical connection method. In the design of splines, the fillet treatment of the spline surface can effectively reduce stress concentration and improve the fatigue strength and fracture resistance of the parts. On the other hand, the fillet treatment of the spline surface increases the storage space of the spline lubricant, making it easier for the lubricant to enter the spline contact surface to form a uniform oil film, reducing the friction and wear of the spline. In addition, the fillet treatment of the spline surface can effectively prevent the sharp edges and corners of the spline from being damaged and scratched during the operation of the spline.

[0003] At present, the CNC chamfering processing technology of spline surface has gradually begun to be studied. However, one of the key difficulties is to find the angular direction of the spline before processing. The conventional solution is to design some auxiliary tooling or fixtures to complete the angular positioning of the spline, which greatly increases the tooling cost and time cost of spline chamfering processing.

[0004] The patent with publication number CN106735602A discloses a gear shaping tooling and processing method for small-module internal spline parts of aviation, including a clamping body, a blocking body, a hexagon socket head screw, a positioning plate, a positioning spindle, a spline part, a gear shaping cutter, and a tool connecting rod, wherein: the blocking body is inserted into the clamping body by fitting, the clamping body is provided with small holes around it, the clamping body is provided with a U-shaped notch, the positioning plate is mounted on the clamping body by means of a hexagon socket head screw, the spline part is positioned and mounted on the positioning plate by means of a positioning spindle, and the gear shaping cutter is connected to the main shaft of the gear shaping machine by means of a tool connecting rod; a gear shaping method for small-module internal spline parts of aviation, comprising the following steps: a. installation and alignment of the gear shaping cutter; b. installation and alignment of the workpiece; c. workpiece processing; d. workpiece inspection; the disadvantage of this patent is that special auxiliary tooling needs to be designed for alignment, which greatly increases the processing cost and processing time. Summary of the Invention

[0005] The present invention mainly addresses the problem that the CNC chamfering processing method of spline surface in the existing technology requires the design of some auxiliary tooling or fixtures to complete the angular positioning of the spline, which greatly increases the tooling cost and time cost of spline chamfering processing. A spline surface chamfering processing method with self-positioning angular spline is proposed.

[0006] In view of the above problems, the technical solutions of the present invention are as follows:

[0007] A method for rounding a spline surface with angular self-positioning of the spline, comprising the following steps:

[0008] S1. Provide a keyway on the disc gear shaping cutter, wherein the keyway is aligned with the angular relationship of any tooth of the gear shaping cutter, and design a matching key on the gear shaping cutter shank so that the angular relationship of the gear shaping cutter relative to the machine tool is aligned; secure the part to the CNC machining center by designing a fixture with locating pins;

[0009] S2. Before gear shaping, at least one positioning hole is machined on the part, wherein the positioning hole is used for the part to cooperate with the positioning pin of the gear shaping fixture during gear shaping;

[0010] S3. During gear shaping, the cutting point of the gear shaping cutter is fixed at a certain position of the spline to be processed on the part through the machine tool control program, and then the spline chamfering is performed. The part is fixed by designing a fixture with a locating pin. The locating hole of the part is consistent with the locating hole installed in the gear shaping process. Finally, a forming column milling cutter that matches the chamfering size of the spline surface is used to chamfer the spline surface.

[0011] Furthermore, in the step S1, the gear shaping cutter and the gear shaping cutter bar are connected via a keyway according to the interface type of the gear shaping machine tool, so that the angular relationship between the gear shaping cutter and the gear shaping cutter bar remains unchanged.

[0012] Furthermore, a common flat key is provided at the inner hole of the gear shaping cutter, or an end face keyway is provided at the end of the gear shaping cutter away from the cutting edge.

[0013] Furthermore, the keyway is angularly consistent with any slotting tooth of the gear shaping cutter.

[0014] Furthermore, in step S1, the key is provided on the mating surface of the gear shaping cutter and the gear shaping cutter rod.

[0015] Furthermore, in step S2, the positioning pin is a diamond pin or a cylindrical pin.

[0016] Furthermore, in step S3, the part is placed on a gear shaping fixture, the part positioning hole is inserted into the positioning pin of the gear shaping fixture, and the alignment fixture and the part positioning plane are aligned to a runout of no more than 0.015 mm.

[0017] Furthermore, the part is fixed to the gear shaping fixture by means of a split washer and a hexagonal nut, and the runout of the upper end face of the part is checked to be no greater than 0.01 mm.

[0018] Furthermore, in step S3, the arc radius R of the forming column milling cutter is 0.2, the diameter ФA is 0.8 mm, and the tool processing depth L is 0.55 mm.

[0019] Furthermore, the diameter of the forming column milling cutter is set to 0.8mm, the processing depth is 0.55mm, the tool speed is 5000r / min, the feed is F100mm / min, and the processing tool path is selected for the entire internal spline surface; the milling starting point is the square root circle of the X-axis.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The present invention aims at splines to be processed by slotting. A keyway is provided on a disc-type gear shaping cutter, and the angular relationship between the keyway and any tooth of the gear shaping cutter is ensured to be consistent. A matching key is then designed on the gear shaping cutter arbor to ensure that the angular relationship of the gear shaping cutter relative to the machine tool is consistent. A fixture with locating pins is designed to fix the part on the CNC machining center, so that the spline can be self-positioned to complete the spline chamfering process. This method has high processing efficiency. Compared with the use of spline alignment tooling, the present invention only requires the spline angular fixation on necessary tooling such as the gear shaping cutter, gear shaping cutter arbor, and clamping fixture, which saves tooling costs and greatly shortens the time required to align the spline angular position before chamfering the spline profile.

[0022] 2. The method of the present invention has wide applicability and can be used in other spline forming processes such as gear grinding and gear drawing. It only needs to ensure that the angular relationship between the parts in the spline forming process and the spline surface rounding process is fixed.

[0023] 3. In addition to being used for chamfering spline surfaces, the method of the present invention can also be used for chamfering gear surfaces or similar special surfaces. If a forming chamfering cutter is used, it can also be used for chamfering special surfaces. For chamfering the spline surfaces of smaller parts, a tooling with multiple clamps can be designed to complete the spline chamfering of multiple parts by simply ensuring that each part is connected to the clamp through a locating hole in the same position. This process is not affected by whether the machine tool is vertical or horizontal. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the gear shaping process of the present invention;

[0025] Figure 2 Schematic diagram of the end face keyway gear shaping cutter of the present invention;

[0026] Figure 3 A bottom view of the end face keyway gear shaping cutter of the present invention;

[0027] Figure 4 This is a schematic diagram of the assembly of the gear shaping cutter bar and the gear shaping cutter of the present invention;

[0028] Figure 5 This is a schematic diagram of parts clamping of the present invention;

[0029] Figure 6This is a structural diagram of the forming column milling cutter of the present invention;

[0030] Figure 7 This is the tool path diagram for the internal spline surface milling of the present invention.

[0031] In the above figure, 1. Diamond pin; 2. Gear shaping base; 3. Cylindrical pin; 4. Locating shaft; 5. Hexagon socket head screw; 6. Base; 7. Bolt; 8. Hexagonal thin nut; 9. Split washer; 10. Hexagonal nut with shoulder; 11. Parts; 12. Gear shaping cutter bar; 13. Gear shaping cutter; 14. Forming column milling cutter; 15. Spline; 16. Angular locating end; 17. Support end; 18. Fixed end; 19. Locating end. DETAILED DESCRIPTION

[0032] In order to clearly illustrate the technical features of the application scheme of the present invention, the present invention is described in detail below through specific implementation methods and in conjunction with the accompanying drawings.

[0033] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present application is not limited to the specific embodiments disclosed below.

[0034] In addition, in the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" 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 the present 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 the present application. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0035] In this application, unless otherwise expressly specified or limited, terms such as "installed," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0036] Example 1

[0037] like Figures 1 to 7 As shown, a method for rounding a spline profile with angular self-positioning of the spline comprises the following steps:

[0038] S1. A keyway is provided on the disc gear shaping cutter, wherein the keyway has an angular relationship consistent with any tooth of the gear shaping cutter 13. A matching key is designed on the gear shaping cutter bar 12, so that the gear shaping cutter 13 has an angular relationship consistent with the machine tool. A fixture with a locating pin is designed to fix the part 11 on the CNC machining center. During the actual machining process, the part 11 is fixed to the machine tool using the fixture with the locating pin, and the lowering position of the gear shaping cutter 13 is controlled at a fixed position. This ensures that the angular relationship of the spline 15 machined on the part 11 with respect to the locating hole is always consistent, and replacement of the part 11 or the gear shaping cutter 13 will not affect the process.

[0039] S2. Before gear shaping, at least one positioning hole is machined on the part 11. The positioning hole is used for the part 11 to cooperate with the positioning pin of the gear shaping fixture during gear shaping;

[0040] S3. During gear shaping, the cutting point of the gear shaping cutter 13 is fixed at a certain position of the spline to be processed on the part through the machine tool control program, and then the spline chamfering process is performed. The part 11 is fixed by designing a fixture with a locating pin. The locating hole of the part is consistent with the locating hole installed in the gear shaping process. Finally, a forming column milling cutter 14 that matches the chamfering size of the spline profile is used. The tool path required for processing the spline is selected in the programming software and the G code is generated, so that the spline profile chamfering process with self-positioning of the spline can be realized.

[0041] like Figure 1 As shown, in this embodiment, the gear shaping base 2 is first connected to the gear shaping machine base, and the gear shaping fixture (an integral structure except for the nut and washer in the figure) is connected to the gear shaping base 2, and the three hexagon socket head screws 5 are tightened; the part 11 is placed on the gear shaping fixture, and the part positioning hole is inserted into the diamond pin 1 of the gear shaping fixture. The alignment fixture and the part positioning plane are adjusted to no more than 0.015mm; three open washers 9 and shouldered hexagonal nuts 10 are installed and tightened, and the part 11 is fixed to the gear shaping fixture. It is checked that the runout of the upper end face of the part 11 is no more than 0.01mm; the machine tool is started, and the gear shaping cutter 13 with angular positioning and the gear shaping cutter bar 12 are used to start spline shaping.

[0042] During the actual machining process, the part 11 is fixed on the machine tool by a fixture with a locating pin, and the cutting position of the gear shaping cutter 13 is controlled at a fixed position. In this way, the angular relationship of the spline machined by the part 11 relative to the locating hole can be always consistent and will not be affected by the replacement of the part 11 or the gear shaping cutter 13. By designing a fixture with a locating pin to fix the part 1, it is no longer necessary to align the angular direction of the spline 15 during the subsequent spline surface chamfering process, thereby realizing the self-positioning spline surface chamfering process of the spline 15.

[0043] like Figure 2 、 Figure 3 and Figure 4 As shown, in order to ensure that the gear shaping cutter 13 matches the gear shaping cutter bar 12, according to the interface type of the gear shaping machine tool, a special gear shaping cutter bar 12 is designed to match its keyway, as shown in the following example. Figure 2 As shown, the mating surfaces of the gear shaping cutter rod 12 and the gear shaping cutter 13 have matching keys; a keyway is opened on the end surface of the gear shaping cutter 13 away from the blade end to increase the rigidity of the gear shaping cutter 13. It should be noted that the keyway must be consistent with the angular direction of any cutting tooth of the gear shaping cutter 13.

[0044] Example 2

[0045] like Figures 1 to 7 As shown, a method for rounding a spline profile with angular self-positioning of the spline comprises the following steps:

[0046] S1. A keyway is provided on the disc gear shaping cutter, wherein the keyway has an angular relationship consistent with any tooth of the gear shaping cutter 13. A matching key is designed on the gear shaping cutter bar 12, so that the gear shaping cutter 13 has an angular relationship consistent with the machine tool. A fixture with a locating pin is designed to fix the part 11 on the CNC machining center. During the actual machining process, the part 11 is fixed to the machine tool using the fixture with the locating pin, and the lowering position of the gear shaping cutter 13 is controlled at a fixed position. This ensures that the angular relationship of the spline 15 machined on the part 11 with respect to the locating hole is always consistent, and replacement of the part 11 or the gear shaping cutter 13 will not affect the process.

[0047] S2. Before gear shaping, at least one positioning hole is machined on the part 11. The positioning hole is used for the part 11 to cooperate with the positioning pin of the gear shaping fixture during gear shaping;

[0048] S3. During gear shaping, the cutting point of the gear shaping cutter 13 is fixed at a certain position of the spline to be processed on the part through the machine tool control program, and then the spline chamfering process is performed. The part 11 is fixed by designing a fixture with a locating pin. The locating hole of the part is consistent with the locating hole installed in the gear shaping process. Finally, a forming column milling cutter 14 that matches the chamfering size of the spline profile is used. The tool path required for processing the spline is selected in the programming software and the G code is generated, so that the spline profile chamfering process with self-positioning of the spline can be realized.

[0049] like Figure 4 As shown, in this embodiment, the diameter of the part 11 is 369 mm and the length is about 165 mm. The spline to be chamfered is an internal spline located at the end face of the large end of the part 11. The number of teeth is 75, the module is 2.5, the pressure angle is 30°, the major diameter is 191, the minor diameter is 185, the root radius is R0.5, and the spline surface chamfering requirement is R0.2. Both the gear shaping and the spline surface chamfering are processed vertically. The clamping method of the part 11 is as follows: Figure 5 As shown, the bottom of the part 11 is used as the positioning end 19 for positioning, and an angular positioning hole is provided on the left side of the part 11 as the angular positioning end 16, and the part 11 is fixed and supported by a clamp.

[0050] Example 3

[0051] like Figures 1 to 7 As shown, a method for rounding the spline profile with self-positioning angular direction of the spline is shown. In this embodiment, the rounding process of the spline profile is the same as that of the spline profile. Figure 1 Basically the same, except that the gear shaping base 2 needs to be changed to a base plate for CNC machining. The base plate is matched with the vertical machining center platform and fastened together with screws. The specific steps for chamfering are as follows:

[0052] (1) First, connect the gear shaping base 2 to the gear shaping machine base, connect the gear shaping fixture (in the attached figure, it is an integral structure except for the nut and washer) to the gear shaping base 2, and tighten the three hexagon socket head screws 5; place the part 11 on the gear shaping fixture, insert the part positioning hole into the diamond pin 1 of the gear shaping fixture, and align the fixture and the positioning plane of the part 11 to ensure that the runout is no more than 0.015mm; install and tighten the three open washers 9 and the shouldered hexagonal nut 10, fix the part 11 on the gear shaping fixture, and check that the runout of the upper end face of the part 11 is no more than 0.01mm; start the machine tool, use the gear shaping cutter 13 with angular positioning and the gear shaping cutter bar 12 to start shaping the spline; (2) Use the forming column milling cutter 14, such as Figure 6 As shown, the arc radius R is 0.2, the diameter ФA is 0.8mm, and the tool processing depth L is 0.55mm. Therefore, in the programming software, it is only necessary to set the diameter of the forming column milling cutter 14 to 0.8mm, the processing depth to 0.55mm, and the processing tool path to the entire internal spline profile; (3), as Figure 7 As shown, select the tool path for processing the spline required in the programming software and generate the G code. The milling starting point can be the square root circle of the X-axis, so that the filleting of the spline surface inside the entire part 11 can be completed; loosen the nut, re-clamp and align the part 11, and then the spline surface filleting can be directly performed.

[0053] Obviously, the above-described embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. A person skilled in the art would be able to make other variations or modifications based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A method for rounding a spline surface with self-positioning angular spline, characterized in that: The following steps are involved: S1. A keyway is provided on the disc gear shaping cutter, wherein the keyway has an angular relationship consistent with any tooth of the gear shaping cutter. A matching key is designed on the gear shaping cutter arbor, and the gear shaping cutter and the gear shaping cutter arbor are connected via the keyway, so that the angular relationship between the gear shaping cutter and the gear shaping cutter arbor remains unchanged and the gear shaping cutter has an angular relationship consistent with the machine tool; a fixture with a locating pin is designed to secure the part to the CNC machining center; S2. Before gear shaping, at least one positioning hole is machined on the part, wherein the positioning hole is used for the part to cooperate with the positioning pin of the gear shaping fixture during gear shaping; S3. Insert the locating pin of the fixture into the locating hole of the part, and fix the part to the fixture with three open washers and shouldered hexagonal nuts; during gear shaping, fix the cutting point of the gear shaping cutter at a certain position of the spline to be processed on the part through the control program, and finally use a forming column milling cutter that matches the fillet size of the spline surface to fillet the spline surface.

2. A method for rounding a spline surface with angular self-positioning according to claim 1, characterized in that: In the step S1, a keyway is formed on the end face of the gear shaping cutter away from the cutting edge.

3. A method for rounding a spline surface with angular self-positioning according to claim 1, characterized in that: In step S1, the key is provided on the mating surface of the gear shaping cutter and the gear shaping cutter bar.

4. A method for rounding a spline surface with angular self-positioning according to claim 1, characterized in that: In step S2, the positioning pin is a diamond pin or a cylindrical pin.

5. The method for rounding the spline surface with angular self-positioning according to claim 1, characterized in that: In step S3, the runout between the alignment fixture and the part positioning plane is no more than 0.015 mm.

6. A method for rounding a spline surface with angular self-positioning according to claim 5, characterized in that: Check that the runout of the upper end surface of the part is no more than 0.01mm.

7. A method for rounding a spline surface with angular self-positioning according to claim 1, characterized in that: In step S3, the arc radius R of the forming column milling cutter is 0.2 mm, the diameter ØA is 0.8 mm, and the tool processing depth L is 0.55 mm.

8. A method for rounding a spline surface with angular self-positioning according to claim 7, characterized in that: The rotation speed of the forming column milling cutter is 5000r / min, the feed is F100mm / min, and the processing tool path is selected for the entire internal spline surface; the milling starting point is the root circle in the positive direction of the X axis.

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