JPH04319037A - Formation of helical spline having stoppers on rotary shaft - Google Patents

Abstract

PURPOSE:To obtain a formation of helical splines having stoppers on a rotary shaft formed easily with a small working manhour and in a short time. CONSTITUTION:A large diametrical part of a shaft to be worked is clamped between a pair of rolling tools providing plural lines of helical teeth and continuous teeth continuing to every other line of these helical teeth on the surface, the shafts to be worked are rolled and pressed by the movement of both rolling tools, plural lines of helical spline grooves on the large diametrical part, communicating grooves continuing to every other helical groove before the plural lines of the helical spline rooves and stopper parts left between these communicating grooves are formed at one stage.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a helical spline with a stopper on a rotating shaft for connecting driven bodies with a helical spline to prevent them from coming off.

0002

[Prior Art] For example, as shown in Japanese Utility Model Application No. 55-53727, the output shaft of a starting motor is provided with a helical spline with a stopper, and the sleeve portion of the clutch outer of an overrunning clutch is spline-coupled. ,
A stopper prevents it from slipping out in the axial direction.

A conventional method for forming a helical spline with a stopper on a rotating shaft is shown in FIG. First, as shown in FIG. 4A, a round bar material such as a steel material is cold-forged to form a large diameter portion 1a, a small diameter portion 1b, and a stopper portion 2, thereby forming a shaft 1 to be machined. A plurality of grooves 2a (three grooves in the figure) are formed in the stopper portion 2 at equal pitches in the circumferential direction. Next, in order to form twice the number of helical grooves (6 grooves in the figure) in the large diameter portion 1a (3 of which communicate with the groove 2a), helical teeth are arranged at equal pitches around the outer circumference. The large diameter portion 1a of the shaft 1 to be processed is sandwiched from above and below by a pair of provided rolling rollers. Both rolling rollers are rotated in opposite directions to apply pressure while rolling the shaft 1 to be processed. In this way, as shown in Figure 4B, the number of threads is doubled (6 in the figure).
A rotating shaft 4 is completed in which a helical spline 3 having a helical groove 3a (stripes) is formed. Among the helical grooves 3a, every other half of the grooves communicate with the groove 2a, and one end of the other half of every other groove reaches the stopper portion 2.

In the case of a starter motor, the inner periphery of the sleeve portion of the clutch outer of the overrunning clutch is provided with the same number of helical tooth portions that can engage and pass through the groove 2a of the stopper portion 2. Pass each helical tooth part of the sleeve part of this clutch outer in the axial direction through each groove 2a of the rotating shaft 4, pass through the groove 3a once and remove it, rotate the clutch outer by one pitch of the groove 3a, and The part is fitted into the groove 3a corresponding to the stopper part 2 and pulled back in the axial direction. As a result, the outer end of the tooth portion is received by the stopper portion 2, and the clutch outer is prevented from slipping outward in the axial direction.

Next, as another conventional method of forming a helical spline with a stopper for a rotating shaft, there is a method shown in FIG. First, as shown in FIG. 5A, a round bar material such as a steel material is cold forged to form a large diameter portion 5a and a small diameter portion 5b, and is used as a shaft 5 to be machined. Subsequently, as shown in FIG. 5B, a stopper protrusion 6 is formed by machining an annular groove 5c at one end of the large diameter portion 5a. Next, the large diameter portion 5a of the workpiece shaft 5, on which the stopper protrusion 6 is formed, is sandwiched between a pair of upper and lower rolling rollers each provided with a plurality of helical teeth, and both rolling rollers are are rotated in opposite directions to apply pressure while rolling the shaft 5 to be processed. In this way, as shown in FIG. 5C, a helical spline 7 having a plurality of equally pitched helical grooves 7a (six grooves in the figure) is formed in the large diameter portion 5a. Furthermore, as shown in FIG. 5D, the stopper protrusion 6
Next, by cutting every other groove 7a to provide communication grooves 8a in the axial direction, the stopper portion 8 is formed using the remaining portion. As a result, a rotating shaft 9 having a helical spline 7 and a stopper portion 8 is completed.

[0006]

[Problems to be Solved by the Invention] In the conventional method of forming a helical spline with a stopper for a rotating shaft as described above,
According to the method shown in FIG. 4, there is a problem that it is difficult to index the positions of the teeth of the pair of upper and lower rolling rollers and the grooves 2a formed on the shaft 1 to be processed in the rolling process. there were.

Further, according to the method shown in FIG. 5, the number of processing steps for the helical spline 7 and the stopper portion 8 is increased, and furthermore, it is difficult to cut every other groove 8a for forming the stopper portion 8. was there.

Furthermore, when a flange is provided at one end, such as on the output shaft of a starting motor with a planetary gear reduction device, the flange portion becomes an obstruction in the conventional cold forging shown in FIG. 4B, making it difficult to perform the process. There was a problem.

The present invention has been made to solve these problems, and aims to provide a method for forming a helical spline with a stopper on a rotating shaft, which reduces the number of processing steps and can be easily performed in a short time. The purpose is

0010

[Means for Solving the Problems] A method for forming a helical spline with a stopper for a rotating shaft according to the present invention includes a plurality of helical teeth and continuous teeth that are connected to the helical teeth at every other thread in front of the helical teeth. The large diameter part of the shaft to be machined is sandwiched between a pair of rolling tools, and the rolling tools apply pressure while rolling the shaft to form multiple helical grooves in the large diameter part. In the front part of this helical groove, communication grooves communicating with every other groove and stopper portions left between these communication grooves are formed.

[0011]

[Operation] In this invention, the large diameter part of the shaft to be machined is sandwiched between a pair of rolling tools, and the shaft to be machined is rolled by the motion of both rolling tools, and pressure is applied. A helical spline having a plurality of helical grooves in the diameter portion, a communication groove communicating with every other groove in front of the helical groove, and a stopper portion are formed in one step.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1A shows a rolling tool used in an embodiment of the method for forming a helical spline with a stopper on a rotary shaft according to the present invention. Reference numeral 10 denotes a first rolling roller for forming a helical spline, and a plurality of (six in the figure) helical teeth 10a are provided on the circumferential portion at equal pitches in the circumferential direction. Reference numeral 11 denotes a second rolling roller for forming a stopper portion and a communication groove therebetween, and the circumferential portion thereof is provided with communication teeth 11a that are continuous at every other row among the helical teeth 10a. FIG. 1B shows a developed view of the helical teeth 10a and the communicating teeth 11a of the rolling rollers 10 and 11.

The first rolling roller 10 and the second rolling roller 11 are connected in the axial direction with bolts or the like, and the rolling tool 1
2. Although one pair of rolling tools 12 is used, the first rolling roller 10 and the second rolling roller 11 may be formed as a single unit instead of being combined.

Next, a method for forming a helical spline with a stopper on a rotary shaft using the pair of rolling tools 12 described above is as follows.
This will be explained with reference to FIG. First, as shown in FIG. 2A, the shaft 13 to be machined has a large diameter portion 13a and a small diameter portion 13b formed by cold forging. If one end has a flange and cold forging is difficult, cutting is required.

Next, as shown in FIG. 1, the large diameter portion 13a of the shaft 13 to be machined is sandwiched between a pair of rolling tools 12, and both rolling tools 12 are rotated in opposite directions to form the workpiece. axis 1
Roll 3. By applying a pressing force to both rolling tools 12 and reducing the interval, the large diameter portion 13 of the shaft 13 to be machined is
A helical spline with a stopper is formed at a.

In this way, as shown in FIG. 2B, a plurality of strips (
A helical spline 14 having six (6) helical grooves 14a in the figure, communication grooves 15a that communicate with the helical grooves 14a every other line, and stopper portions 15 left between the communication grooves 15a in the circumferential direction are formed. be done. As a result, the rotating shaft 16 on which the helical spline 14 and the stopper portion 15 are formed is completed.

If the corner between the inner side of the stopper portion 15 and the end of the helical groove 14a shown in FIG. 2B has a burr due to rolling, which poses a problem in practical use, the method shown in FIG. 3 is adopted. An annular groove 17 is formed by cutting on the inner side of the stopper portion 15, and is used as a rotating shaft 18.

Further, in the above embodiment, a rolling roller having a plurality of helical teeth 10a and communicating teeth 11a on its surface was used as the rolling tool. Other types of rolling tools may be used as long as they are formed in one step. For example, a rolling tool is made of a rack-like body having a plurality of helical teeth and a continuous tooth continuous to every other helical tooth on its front surface. A helical spline with a stopper is formed by sandwiching the large diameter portion of the shaft to be machined between the pair of rolling tools and rolling and pressing the shaft.

[0019]

As described above, according to the present invention, between a pair of rolling tools each having a plurality of helical teeth and a continuous tooth continuous to every other helical tooth on the front surface thereof, Then, the large diameter part of the shaft to be machined is clamped, and the shaft is rolled and pressed by the movement of both rolling tools to form multiple helical grooves in the large diameter part and every other groove in the front part. Since the communication grooves leading to the communication grooves and the stopper portions left between these communication grooves are formed, the helical spline with the stopper can be formed in one step, and the processing is easy and can be done in a short time.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a rolling tool used in an embodiment of the method for forming a helical spline with a stopper on a rotary shaft according to the present invention, and FIG. It is a diagram.

FIG. 2 is a front view of main parts showing the method of forming a helical spline with a stopper on a rotating shaft according to the present invention in order of steps;

FIG. 3 is a front view of main parts showing post-processing of the rotating shaft of FIG. 2B showing another embodiment of the present invention.

FIG. 4 is a front view of main parts showing a conventional method for forming a helical spline with a stopper on a rotating shaft in order of steps.

FIG. 5 is a front view showing the process order of another conventional method for forming a helical spline with a stopper for a rotating shaft.

[Explanation of symbols]

10, 11 Rolling roller 10a Helical tooth 11a Continuous tooth 12 Rolling tool 13 Workpiece shaft 13a Large diameter portion 13b Small diameter portion 14 Helical spline 14a
Helical groove 15 Stopper part 15a Communication groove 16, 18 Rotating shaft

Claims (1)

[Claims] Claim 1: A step of forming a large-diameter portion and a small-diameter portion on a shaft to be machined, a plurality of helical teeth having an equal pitch, and communicating teeth that are connected to the helical teeth at every other thread in front of the helical teeth. The large diameter portion of the shaft to be machined is sandwiched between a pair of rolling tools, and the shaft is rolled and pressed by the motion of both rolling tools, forming multiple helical threads on the large diameter portion. By the step of forming at once the grooves, the communicating grooves communicating with every other groove in the front part, and the stopper portions remaining between these communicating grooves,
Method for forming a helical spline with a stopper on a rotating shaft.