JPH0749073Y2 - Slip spline - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a sliding spline in which a resin is interposed between a female spline tooth and a male spline tooth.

[Conventional technology]

The sliding spline is used, for example, in a telescopic steering column of a vehicle, a propeller shaft sleeve yoke, etc., and is disclosed in Japanese Utility Model Publication No. 55-134373 and Japanese Utility Model Publication 59-1670.
The 62 gazette and the Institute of Invention Publication No. 83-10085 technical report show the structure in the vicinity of such a slip spline.

In this type of sliding spline, it is required to reduce the sliding resistance in the axial direction and reduce the play (play) between the male spline teeth and the female spline teeth of the sliding spline.

FIG. 3 shows a conventional sliding spline, particularly when it is applied to a telescopic steering column of a vehicle. In the figure, 1 indicates a female spline,
11 shows the male spline. As shown in FIG. 4, the female spline 1 is formed with a plurality of female spline teeth 2 in the circumferential direction, and the male spline 11 is formed with a plurality of male spline teeth 12 in the circumferential direction. The male spline 11 is inserted into the female spline 1, and the female spline tooth 2 and the male spline tooth 12 are engaged with each other so as to be slidable in the axial direction and non-rotatable around the axis. A resin film (nylon rim) 21 is formed between the female spline tooth 2 and the male spline tooth 12, and the male spline is formed.
11 can slide smoothly in the axial direction without any rattling. A key lock holder 22 is joined to the outer peripheral surface of the female spline 1, and the other end of the female spline 1 is
The joint yoke 23 is joined.

In this type of sliding spline, the resin film 21 is formed with the female spline teeth 2 and the male spline teeth 12 engaged with each other. That is, the reactive resin is previously filled inside the female spline tooth 2, and then the male spline tooth 12 is inserted into the female spline tooth 2, and the resin is actually molded by the both spline teeth 2 and 12. The resin film 21 is adapted to be bonded to the male spline tooth 12 side, and when the formation of the resin film 21 is completed by cooling and solidification,
The male spline 11 is pulled out from the female spline 1.

By the way, when the resin film 21 is molded, a release agent is applied to the female spline teeth 2 of the female spline 1 in advance by spraying or the like. This is for facilitating the removal of the male spline 11 from the female spline 1 after the resin film 21 is formed, and a fine gap is formed between the female spline tooth 2 and the surface of the resin film 21 by the release agent, so that the female spline is formed. This is to improve slidability between the male spline 1 and the male spline 2.

[Problems to be solved by the device]

However, in the case of the female spline tooth shown in FIG. 4 in which the tip end A in the circumferential direction of the tooth tip is angular, when the release agent is applied, the end point A of the square shape is located. The release agent does not adhere easily, and the film thickness of the release agent at the end A cannot be sufficiently secured. Therefore, there is a problem that it becomes difficult to pull out the male spline 2 from the female spline 1 after the resin film 21 is formed, and the sliding resistance between the female spline 1 and the male spline 2 becomes large even after the reassembly.

An object of the present invention is to provide a sliding spline capable of uniformly adhering a release agent to female spline teeth and reducing sliding resistance between the female spline and the male spline.

[Means for Solving the Problems]

To achieve this object, a sliding spline according to the present invention comprises a female spline having a plurality of female spline teeth on its inner circumference, and a female spline which is inserted into the female spline and is slidable in the axial direction with the female spline teeth. A male spline having a plurality of male spline teeth that are non-rotatably engaged around, and a slip filled with resin between the female spline teeth and the male spline teeth after applying a release agent to the female spline teeth. The spline includes a female spline tooth to which the release agent is applied, in which at least the end of the tooth tip in the circumferential direction is formed in an arc shape.

[Action]

In the sliding spline configured as described above, at least the ends of the tips of the female spline teeth are formed in an arc shape, so that it is possible to uniformly and sufficiently apply the release agent to the female spline teeth. Become. Therefore, after forming the resin film by filling the resin between the female spline tooth and the male spline tooth, the male spline can be easily pulled out from the female spline.

Further, after the reassembling, a fine gap can be uniformly formed in the circumferential direction between the surface of the resin film and the female spline teeth, and the slidability between the female spline and the male spline is improved.

〔Example〕

Hereinafter, a preferred embodiment of the sliding spline according to the present invention will be described with reference to the drawings.

1 and 2 show an embodiment of the present invention.
Since the sliding spline of this embodiment conforms to FIGS. 3 and 4 shown in the prior art, the corresponding parts are designated by the same reference numerals as in FIGS. 3 and 4, and the description of the corresponding parts is omitted. Only different parts will be described.

In FIG. 1, 1 indicates a female spline and 11 indicates a male spline. The inner circumference of the female spline 1
A plurality of female spline teeth 2 are formed, and the tips of the female spline teeth 2 are arcuate. That is, the tooth tip 2a of the female spline tooth 2 is not formed with the rectangular end portion A as shown in FIG. 4, and the shape of the entire tooth tip changes smoothly in an arc shape. The roots 2b of the female spline teeth 2 are formed in a rectangular shape as in the conventional case. The male spline tooth 12 is formed in a similar shape to the female spline tooth 2, and the resin film 21 located between the female spline tooth 2 and the male spline tooth 12 has a uniform thickness in the circumferential direction.

In addition, in the present embodiment, the entire tooth tip of the female spline tooth 2 is arcuate, but if the configuration is such that the circumferential end of the tooth tip 2a is substantially arcuate, the desired effect can be obtained sufficiently. can get.

Next, the action of the above-mentioned slip spline will be described.

When the resin film 21 is formed, a release agent is applied to the female spline teeth 2 in advance by spraying or the like. In this case, since the tooth tips of the female spline teeth 2 are formed in an arcuate shape, the release agent can be uniformly and sufficiently applied to the entire female spline teeth 2. When the application of the release agent is completed, the molten resin is injected into the female spline tooth 2 side, then the male spline 11 is inserted into the female spline 1, and the molten resin is injected between the female spline tooth 2 and the male spline tooth 12. It is cooled and solidified.

When the resin film 21 is fixed to the male spline tooth 12, the male spline 11 is pulled out from the female spline 1. In this case, since the release agent is uniformly applied to the female spline teeth 2, the male spline 11 can be easily pulled out from the female spline 1.

Next, the separated female spline 1 is set in a welding device (not shown), and a joint yoke 23 is joined to the end of the female spline 1 by friction welding. When the joining of the joint yoke 23 is completed, the female spline 1 and the male spline 11 are reassembled. In this case, since the release agent attached to the female spline teeth 2 has been removed, it is possible to uniformly form fine gaps between the surface of the resin film 21 after reassembly and the female spline teeth 2. it can. Therefore, female spline 1 and male spline 11
The sliding resistance when sliding with the
As shown in the figure, it can be reduced from the conventional characteristic B to the characteristic C. In other words, with the conventional structure 1.5 to 5 kg
In the case of the present invention, it requires 1 to 3.5 kg
If the sliding spline is applied to the telescopic steering of the vehicle, it becomes easy to adjust the position of the steering wheel (steering wheel).

By the way, in the case of a sliding spline, in which resin is currently combined between the female spline tooth and the male spline tooth, each tooth profile is almost completely similar to both the female spline and the male spline, and the tooth tip has a circumferential end portion. When is rectangular, the root of the tooth is naturally formed into a polygon. for that reason,
When a torsional torque is applied to the sliding spline, stress concentration is likely to occur at this corner, and the torsional fatigue life is reduced.

However, as in the present invention, the tip 2a of the female spline tooth 2 is
By forming the circular arc shape, it is possible to improve the torsional fatigue life. This was clarified by the durability test. The conventional tooth profile shown in Fig. 4 and the sliding spline with the tooth profile shown in Fig. 1 were subjected to a torsional fatigue durability test by applying a repeating torque of 6.9 kg-m. As a result, the life of 700,000 cycles has been
We were able to improve the service life by 15%.

The female spline teeth 2 are generally manufactured by broaching, but by making the tooth tips 2a of the female spline teeth 2 arcuate, the life of the broaching tool can be improved. This is because the state around the cutting oil is improved and the cutting length in the tooth profile direction is shortened.

[Effect of device]

According to the sliding spline of the present invention, since at least the circumferential ends of the tips of the female spline teeth are formed in an arc shape, the release agent should be applied to the female spline teeth with a uniform film thickness. Is possible. Therefore,
After forming the resin film by filling the resin between the female spline tooth and the male spline tooth, the male spline can be easily pulled out from the female spline, and after reassembly,
The sliding resistance between the female spline and the male spline can be reduced. Thus, when the sliding spline is applied to the steering column of the vehicle, the position of the steering wheel can be adjusted with a light force.

Further, by making the tips of the female spline teeth arcuate, stress concentration can be relieved and the torsional fatigue life can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a main part of a sliding spline according to an embodiment of the present invention, FIG. 2 is a characteristic diagram showing the sliding force between the sliding spline of FIG. 1 and a conventional sliding spline, and FIG. 3 is a conventional sliding. FIG. 4 is a sectional view of the spline, and FIG. 4 is a sectional view taken along the line IV-IV in FIG. 1 …… Female spline 2 …… Female spline tooth 2a …… Tooth tip 11 …… Male spline 12 …… Male spline tooth 21 …… Resin film (resin)

Claims (1)

[Scope of utility model registration request] 1. A female spline having a plurality of female spline teeth on its inner circumference, and a plurality of female splines which are inserted into the female spline and are engaged with the female spline teeth so as to be slidable in the axial direction and non-rotatable around the axis. With a male spline having a male spline tooth, in a sliding spline filled with a resin between the female spline tooth and the male spline tooth after applying the releasing agent to the female spline tooth, the release agent is applied. A sliding spline characterized in that at least the end of the tooth tip of the female spline tooth in the circumferential direction is formed in an arc shape.