Machining tool for external spline with side teeth

Abstract

The utility model relates to the field of machining tools, and discloses a machining tool for an external spline with side teeth, which comprises an external spline hobbing cutter and an external spline side tooth milling cutter, a plurality of groups of hobbing cutter teeth are arranged on the external spline hobbing cutter along the axial direction, a root digging structure is arranged at the tooth top of each hobbing cutter tooth, and a chamfer is arranged at the tooth root of each hobbing cutter tooth; the external spline side tooth milling cutter comprises a milling cutter rod, a milling cutter blade is installed at the end of the milling cutter rod, an involute-shaped cutting edge is arranged on the milling cutter blade, and a plurality of involute cutting edge teeth are arranged on the cutting edge side by side. The external spline driving shaft capable of machining the spline with the side teeth solves the problem that in the prior art, a cutter capable of machining the external spline of the spline driving shaft in the design does not exist, and the machining requirement of the external spline with the side teeth cannot be met.

Description

Technical Field

[0001] The utility model relates to the field of machining tools, and particularly relates to a machining tool with side teeth external splines. Background Art

[0002] Automobile wheel hub bearings are key components of the automobile transmission system, and their performance directly affects the running stability of the automobile. Due to the traditional straight-tooth involute spline transmission structure, there is a side clearance between the internal and external spline teeth, and abnormal noises will occur during the forward and reverse driving and acceleration and deceleration of the automobile. On the one hand, the repeated impact of the involute spline teeth affects the fatigue life of the spline teeth, and the abnormal noise also affects the product performance and the comfort of the passengers and drivers; on the other hand, due to the side clearance, there are the maximum side clearance and the minimum side clearance in the spline fit, and only part of the splines are loaded, resulting in a large load on some spline teeth, thereby accelerating the failure of the spline teeth. To solve the above problems, a spline fit transmission structure with side teeth is proposed. The spline drive shaft and the internal spline of the wheel hub bearing adopted in this design are provided with side teeth on the tooth surface on the conventional spline teeth, which can ensure more pairs of spline teeth to mesh and make the splines evenly loaded. However, in the prior art, there is no tool that can machine the external splines of the spline drive shaft in this design, and it cannot meet the machining requirements of the external splines with side teeth. Content of the Utility Model

[0003] The purpose of the utility model is to provide a machining tool with side teeth external splines to solve the problem that there is no tool in the prior art that can machine the external splines of the spline drive shaft in this design and cannot meet the machining requirements of the external splines with side teeth.

[0004] To achieve the above purpose, the utility model adopts the following technical scheme: A machining tool with side teeth external splines includes an external spline hob and an external spline side tooth milling cutter. Multiple groups of hob teeth are arranged axially on the external spline hob. A root cutting structure is provided at the tooth top of the hob teeth, and a chamfer is provided at the tooth root of the hob teeth; the external spline side tooth milling cutter includes a milling cutter rod, and a milling cutter blade is installed at the end of the milling cutter rod. An involute-shaped cutting edge is provided on the milling cutter blade, and multiple involute cutting teeth are arranged side by side on the cutting edge.

[0005] Preferably, as an improvement, the root cutting structure includes a root cutting surface provided between the tooth surface and the tooth top surface of the hob teeth, and the root cutting surface is in arc transition with the tooth top surface of the hob teeth.

[0006] Preferably, as an improvement, the included angle between the root cutting surface and the radial surface of the external spline hob is 15°, the included angle between the tooth surface of the hob teeth and the radial surface of the external spline hob is 30°, and the included angle between the tooth root chamfer of the hob teeth and the radial surface of the external spline hob is 49°.

[0007] Preferably, as an improvement, the tooth root chamfer of the hob teeth is the same as the tooth top chamfer of the external spline to be machined. This can reduce the burrs on the tooth top circle of the external spline side teeth after machining.

[0008] Preferably, as an improvement, the distance between the starting point of the root chamfer of the hob tooth and the tooth tip of the hob tooth is equal to half of the difference between the chamfer diameter of the external spline to be machined and the root circle diameter of the external spline to be machined. This can reduce the cutting stress of the side teeth of the external spline after machining.

[0009] Preferably, as an improvement, two blade seats symmetric about the axis of the milling cutter bar are provided at the end of the milling cutter bar. The blade seats are in the shape of a quarter frustum of a cone. Chamfers are provided at both the top and the root of the blade seat. An arc surface is formed between the top chamfer and the root chamfer of the blade seat. Two blade grooves symmetric about the axis of the milling cutter bar are formed between the two blade seats. The milling cutter inserts are installed in the blade grooves.

[0010] Preferably, as an improvement, the milling cutter insert is L-shaped. The outer corner of the milling cutter insert has an arc transition. The inner side of the milling cutter insert is a blade with an involute shape. The involute dimension of the blade is the same as the involute dimension of the external spline to be machined.

[0011] Preferably, as an improvement, five involute blade teeth are provided on the blade.

[0012] Preferably, as an improvement, the involute dimension of the involute blade teeth is the same as the involute dimension of the upper side teeth of the external spline to be machined.

[0013] The principle and advantages of this solution are as follows: In practical applications, an involute external spline is formed by hobbing on the drive shaft of the automotive wheel hub bearing with an external spline hob. The root of the hob tooth forms a chamfer at the tooth tip of the spline, and the root cutting structure of the hob tooth tip performs root cutting at the root of the spline. Then, local quenching treatment is carried out on the external spline drive shaft, and then the side teeth of the external spline of the external spline drive shaft are hard-milled on a CNC milling machine with an external spline side tooth milling cutter. The milling cutter bar is vertically clamped on the CNC milling machine. The axis of the milling cutter bar is aligned with the axis of the external spline drive shaft. The blade grooves and the blade seats provide installation support for the milling cutter inserts. The milling cutter inserts rotate under the drive of the CNC milling machine and feed axially along the external spline drive shaft. During the rotation of the milling cutter inserts, the blades machine the teeth of the external spline on the drive shaft, forming five involute side teeth from the root to the tooth tip on the tooth surface of the external spline. Similarly, each external spline is machined with teeth, so that side teeth are formed on each spline of the external spline drive shaft. The external spline hob and the external spline side tooth milling cutter provided by the present utility model can effectively machine and form an external spline drive shaft with side teeth, meeting the processing requirements of the side-tooth external spline in the new automotive wheel hub bearing design. Description of the Drawings

[0014] Figure 1 It is a radial partial sectional view of the external spline hob according to an embodiment of the present utility model.

[0015] Figure 2 It is an enlarged axial tooth profile view of the hob tooth according to an embodiment of the present utility model.

[0016] Figure 3 This is an axonometric view of the milling cutter bar according to an embodiment of the present utility model.

[0017] Figure 4 This is a rear view of the milling cutter blade according to an embodiment of the present utility model.

[0018] Figure 5 This is an axonometric view of the external spline side-tooth milling cutter according to an embodiment of the present utility model.

[0019] Figure 6 This is a sectional view of the drive shaft according to an embodiment of the present utility model. Detailed implementation manners

[0020] The following is a further detailed description through specific implementation manners:

[0021] The reference numerals in the accompanying drawings of the specification include: external spline hob 1, hob teeth 2, milling cutter bar 3, blade seat 4, blade groove 5, milling cutter blade 6, cutting edge 7, edge teeth 8, drive shaft 9, spline 10, side teeth 11.

[0022] The embodiment is basically as shown in the accompanying Figure 1 figures: A processing tool with side teeth on the external spline includes an external spline hob 1 and an external spline 10 side-tooth 11 milling cutter. Multiple groups of hob teeth 2 are arranged axially on the external spline hob 1. A root-removing structure is provided at the tooth tip of the hob teeth 2, and a chamfer is provided at the tooth root of the hob teeth 2. As Figure 2 shown, the root-removing structure includes a root-removing surface provided between the tooth surface and the tooth top surface of the hob teeth 2, and the root-removing surface is in arc transition with the tooth top surface of the hob teeth 2. The included angle between the root-removing surface and the radial surface of the external spline hob 1 is 15°, the included angle between the tooth surface of the hob teeth 2 and the radial surface of the external spline hob 1 is 30°, and the included angle between the tooth root chamfer of the hob teeth 2 and the radial surface of the external spline hob 1 is 49°. The tooth root chamfer of the hob teeth 2 is the same as the tooth top chamfer of the to-be-machined external spline 10, so as to reduce the burrs on the tooth top circle of the external spline 10 side teeth 11 after machining. The distance between the starting point of the tooth root chamfer of the hob teeth 2 and the tooth top of the hob teeth 2 is equal to half of the difference between the chamfer diameter of the to-be-machined external spline 10 and the tooth root circle diameter of the to-be-machined external spline 10, so as to reduce the cutting stress of the external spline 10 side teeth 11 after machining.

[0023] As Figure 5 shown, the external spline 10 side-tooth 11 milling cutter includes a cylindrical milling cutter bar 3. As Figure 3 shown, two blade seats 4 symmetric about the axis of the milling cutter bar 3 are provided at the end of the milling cutter bar 3. The blade seats 4 are in the shape of a quarter frustum of a cone. Chamfers are provided at the top and the root of the blade seats 4. An arc surface is formed between the top chamfer and the root chamfer of the blade seats 4. Two blade grooves 5 symmetric about the axis of the milling cutter bar 3 are formed between the two blade seats 4. The milling cutter blades 6 are connected by screws in the blade grooves 5. AsFigure 4 As shown, the milling insert 6 is L-shaped, with an arc transition at the outer corner of the milling insert 6. The inner side of the milling insert 6 is an involute-shaped cutting edge 7, and the involute dimensions of the cutting edge 7 are the same as those of the involute of the external spline 10 to be machined. There are five involute cutting teeth 8 on the cutting edge 7, and the involute dimensions of the involute cutting teeth 8 are the same as those of the upper teeth 11 of the external spline 10 to be machined.

[0024] The specific implementation process is as follows: As shown in combination with Figure 6 shown, an involute external spline 10 is formed by hobbing on the drive shaft 9 of the automotive wheel bearing with an external spline hob 1. The root of the hob tooth 2 forms a chamfer at the tooth top of the spline 10, and the undercut structure at the tooth top of the hob tooth 2 performs undercutting at the tooth root of the spline 10. The tip relief amount of the external spline hob 1 is equal to the undercut amount at the tooth root of the external spline 10. Then, local quenching treatment is performed on the drive shaft 9 of the external spline 10, and then the hard milling of the side teeth 11 of the spline 10 on the drive shaft 9 of the external spline 10 is carried out by a side tooth 11 milling cutter of the external spline 10 on a CNC milling machine. The cutter bar 3 is vertically clamped on the CNC milling machine, and the axis of the cutter bar 3 is aligned with the axis of the drive shaft 9 of the external spline 10. The blade groove 5 and the blade seat 4 provide installation support for the milling insert 6. The milling insert 6 rotates under the drive of the CNC milling machine and feeds axially along the drive shaft 9 of the external spline 10. During the rotation of the milling insert 6, the cutting edge 7 performs milling on the external spline 10 on the drive shaft 9, and five involute side teeth 11 are formed on the tooth surface of the external spline 10 from the tooth root to the tooth top direction. Similarly, milling is performed on each external spline 10, so that side teeth 11 are formed on each spline 10 of the drive shaft 9 of the external spline. The external spline hob 1 and the side tooth 11 milling cutter of the external spline 10 provided by the present invention can effectively machine and form a drive shaft 9 of an external spline 10 with side teeth 11, meeting the processing requirements of the external spline 10 with side teeth 11 in the new design of automotive wheel bearings.

[0025] The above are only embodiments of the present invention. Specific technical solutions and / or common knowledge such as characteristics well known in the art are not described in detail herein. It should be noted that for those skilled in the art, without departing from the technical solution of the present invention, several deformations and improvements can still be made, and these should also be regarded as the protection scope of the present invention, and these will not affect the implementation effect of the present invention and the practicality of the patent. The protection scope required by this application should be based on the content of its claims, and the specific implementation manners described in the specification can be used to interpret the content of the claims.

Claims

1. A machining tool with side tooth external spline, characterized in that: It includes an external spline hob and an external spline side tooth milling cutter. The external spline hob is provided with multiple groups of hob teeth along the axial direction, the tooth tops of the hob teeth are provided with root digging structures, and the tooth roots of the hob teeth are provided with chamfers; the external spline side tooth milling cutter includes a milling cutter rod, a milling blade is installed at the end of the milling cutter rod, the milling blade is provided with an involute-shaped blade, and a plurality of involute teeth are arranged side by side on the blade.

2. A machining tool with side tooth external spline according to claim 1, characterized in that: The root digging structure comprises a root digging surface arranged between the tooth surface and the tooth top surface of the hob tooth, and a circular arc transition is formed between the root digging surface and the tooth top surface of the hob tooth.

3. A machining tool with side-tooth external splines according to claim 2, characterized in that: The angle between the root digging surface and the radial surface of the external spline hob is 15°, the angle between the tooth surface of the hob tooth and the radial surface of the external spline hob is 30°, and the angle between the root chamfer of the hob tooth and the radial surface of the external spline hob is 49°.

4. A machining tool with side-tooth external splines according to claim 3, characterized in that: The root chamfer of the hob tooth is the same as the top chamfer of the external spline tooth to be machined.

5. A machining tool with side-tooth external splines according to claim 4, characterized in that: The distance between the starting point of the hob tooth root chamfer and the tooth top of the hob tooth is equal to half the difference between the chamfer diameter of the external spline to be processed and the root circle diameter of the external spline to be processed.

6. A machining tool with side-tooth external splines according to claim 4, characterized in that: The end of the milling cutter rod is provided with two blade seats symmetrical to the axis of the milling cutter rod. The blade seats are in the shape of a quarter of a truncated cone. The top and root of the blade seats are both provided with chamfers. There is an arc surface between the top chamfer and the root chamfer of the blade seat. Two blade grooves symmetrical to the axis of the milling cutter rod are formed between the two blade seats, and the milling blades are installed in the blade grooves.

7. A machining tool with side-tooth external splines according to claim 4, characterized in that: The milling blade is L-shaped, the outer corner of the milling blade is an arc transition, the inner side of the milling blade is an involute-shaped blade, and the involute size of the blade is the same as the involute size of the external spline to be processed.

8. A machining tool with side-tooth external splines according to claim 4, characterized in that: The blade has five involute teeth.

9. A machining tool with side-tooth external splines according to claim 4, characterized in that: The involute dimension of the involute cutting edge is the same as the involute dimension of the upper side teeth of the external spline to be machined.

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