JPH0371567B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Subject of the Invention] The present invention relates to a telescoping shaft in which an inner shaft is slidably disposed within an outer shaft, and particularly to a telescoping shaft that eliminates play between both shafts. Related.

[Field of application of the invention]

The telescopic shaft according to the invention is suitable for the main shaft of a telescopic steering column of a vehicle, in particular of a motor vehicle.

[Prior Art] A conventional telescopic shaft equipped with this type of backlash removal mechanism is disclosed in US Pat. No. 3,318,170. As shown in FIG. 5, this conventional device includes a hollow outer shaft 31 having a square cross section, a square inner shaft 32 slidably inserted into the outer shaft 31, and an outer shaft provided on the outer shaft 31. 31 and a backlash removing mechanism 34 for removing backlash between the inner shaft 32 and the inner shaft 32. Then, both shafts 31,
32 can be rotated integrally. The backlash removal mechanism 34 has a pair of holes 27 and 29 formed in the outer shaft 31 at the front and rear, balls 28 and 30 serving as guide members are disposed in the holes 27 and 29, and balls 28 and 30 are inserted into the outer peripheral surface of the outer shaft 31. The inclined surfaces 40 and 42 of the pair of ring members 36 and 38 are connected to the ball 2.
8, 30, and both ring members 36, 3
A spring 44 is placed between the balls 28, 3.
0 toward the inner shaft 32 side.

Therefore, each of the ring members 36 and 38 moves on the outer shaft 31 due to the biasing force of the spring 44, thereby creating a space between the inclined surfaces 40 and 42 of each of the ring members 36 and 38 and the outer peripheral surface of the inner shaft 32. The balls 28, 30 are elastically positioned without any gaps. Therefore, it is supported on both sides by a pair of front and rear balls 28, 30 provided on the outer shaft 31,
The inner shaft 32 can be inserted into and removed from or held in the outer shaft 31 without wobbling.

However, the play removal mechanism 34 was provided on the outer shaft 31. Therefore, the assembly is
First, the inner shaft 32 is inserted into the outer shaft 31, and one of the holes 27 and 29, for example, each hole 2, is inserted into the outer shaft 31.
After disposing the ball 28 on the outer shaft 31, both ring members 36, 38 that have been fitted to the outer shaft 31 in advance
Then, the spring 44 is moved toward the hole 27 side against the biasing force of the spring 44, and the ball 28 is placed in the hole 29. Therefore, there was a problem that assembly was extremely difficult.

[Technical problem of the present invention]

Therefore, the technical object of the present invention is to remove the play between the outer shaft and the inner shaft using a simple play removal mechanism.

[Technical means of the present invention]

In order to solve the above problems, the present invention has taken the following technical measures. That is, the inner shaft is disposed within the outer shaft with a predetermined gap, and the gap is filled with a synthetic resin to form a synthetic resin layer using the inner shaft and the outer shaft as a mold, and the synthetic resin layer is formed into the inner shaft. This is because it is fixed to the shaft and a clearance is formed between it and the outer shaft due to mold contraction.

[Operation of the means according to the present invention]

According to the above means, since the synthetic resin layer fixed to either one of the shafts is filled and molded using the outer shaft and the inner shaft as molds, the gap between the synthetic resin layer and the other shaft is extremely small. be done. Therefore, play between the two shafts is prevented.

[Special effects of the present invention]

Furthermore, according to the present invention, play is eliminated in the entirety of both shafts, which is particularly effective in preventing play in the bending direction of the shafts.

Furthermore, simply filling the space between the two shafts with synthetic resin prevents rattling, resulting in a telescopic shaft that is extremely inexpensive compared to the prior art.

Furthermore, since the synthetic resin layer is formed using the outer shaft and the inner shaft as molds, it is possible to completely absorb the dimensional errors of both shafts, and it is possible to obtain a telescopic shaft without backlash caused by dimensional errors. In addition, since the synthetic resin layer is fixed to the inner shaft and a clearance is formed between it and the outer shaft by mold contraction of the synthetic resin layer, the synthetic resin can be firmly and firmly fixed to the inner shaft, and it can also be attached to the shaft. A stable and highly accurate clearance can be obtained, and since this clearance ensures a gap in sliding, a telescopic shaft with stable sliding resistance can be obtained. Furthermore, by changing the gap between the inner shaft and the outer shaft and the number and width of the grooves or protrusions of the key mechanism or spline mechanism formed on the inner shaft, the amount of mold contraction of the synthetic resin, that is, the clearance, can be adjusted. Sliding resistance can be set arbitrarily.

〔Example〕

Next, one embodiment of the present invention will be described based on the drawings.

As shown in FIG.
0 is the outer shaft 20 is the outer shaft 2
2 and an inner shaft 21. The outer shaft 22 has a cylindrical shape, and a cylindrical inner shaft 21 is slidably inserted into the inner peripheral surface of the outer shaft 22 with a predetermined clearance. On the inner peripheral surface of the outer shaft 21, a pair of key grooves 22a are provided in the axial direction.
22b is formed.

On the other hand, a pair of engagement holes 14a and 14b are formed in the outer peripheral surface of the inner shaft 21. Each engagement hole 14a, 14b has a key piece 24, 2, respectively.
5 is locked, and each of the key pieces 24 and 25 is engaged with the key grooves 14a and 14b of the outer shaft 22. Therefore, both shafts 21, 2
2 can rotate integrally and can move relative to each other in the axial direction.

A synthetic resin layer 23 made of epoxy synthetic resin is provided on the outer peripheral surface of the inner shaft 21 .
This synthetic resin layer 23 is formed by filling a synthetic resin between the inner circumferential surface of the outer shaft 22 and the outer circumferential surface of the inner shaft 21 with the inner shaft 21 inserted into the outer shaft 22, and hardening the synthetic resin. It is formed from this. Since the synthetic resin is contracted during this curing, the synthetic resin layer 23 is separated from the inner peripheral surface of the outer shaft 22. Note that a mold release agent may be applied to the inner circumferential surface of the outer shaft 22. On the other hand, the outer peripheral surface of the inner shaft 21 has annular grooves 21a, 21b, 21c at three locations.
is formed. These annular grooves 21a, 21b,
Since the synthetic resin layer 21c and the synthetic resin layer 23 are engaged with each other, the synthetic resin layer 23 is integrated with the inner shaft 21 and is securely fixed to the inner shaft 21. Furthermore, since the synthetic resin layer 23 is molded in a state where it is also filled in the key grooves 22a, 22b of the outer shaft 22, it has engaging protrusions 23a, 23a. Note that, conversely, the synthetic resin layer 23 may be integrated with the outer shaft 22.

Holes 21d and 21e are formed in the axes of both ends of the inner shaft 21, respectively, so that the inner shaft 21 can be supported when the synthetic resin layer 23 is formed. Further, on the outer periphery of the inner shaft 21, an annular stepped portion 16, a serration portion 17, and a threaded portion 1 are provided.
8 is formed. As a result, a steering handle (not shown) can be locked to the serration portion 17, and the steering handle can be held between the stepped portion 16 and a nut (not shown) screwed into the threaded portion 18. Furthermore, an annular protrusion 16a is provided on the outer periphery of the inner shaft 21. A bearing (not shown) that is press-fitted into the outer periphery of the stepped portion 16 is held by the annular protrusion 16a.

On the other hand, the outer shaft 22 is also formed with a serration portion 19, a threaded portion 15, and an annular protrusion 19a, and can be attached to a steering gear box (not shown).

In addition, the key grooves 22a, 22b and the key piece 24,
25 may be replaced by a spline mechanism formed in the axial direction between the inner circumferential surface of the outer shaft 22 and the outer circumferential surface of the inner shaft 21.

Next, the operation of the embodiment will be explained. Both shafts 21, 22 are provided on the outer peripheral surface of the inner shaft 21.
Since the synthetic resin layer 23 filled and molded is fixedly provided between the inner shaft 22 and the outer shaft 21, there is no looseness between the inner circumferential surface of the outer shaft 22 and the outer circumferential surface of the inner shaft 21. However, since the inner circumferential surface of the outer shaft 22 and the outer circumferential surface of the synthetic resin layer 23 are spaced apart, the outer shaft 22 and the inner shaft 21 are relatively movable and are still expandable and contractible. .

Furthermore, the synthetic resin layer 23 on the outer peripheral surface of the inner shaft 21 facilitates relative movement between the inner shaft 21 and the outer shaft 22. Furthermore, since the synthetic resin layer 23 is formed over the entire inserted portion of the inner shaft 21, the telescopic shaft 2
No matter what length the shaft 0 is adjusted to, rattling between the shafts 21 and 22 is always prevented at the maximum span. Therefore, play in the bending direction between both shafts 21 and 22 can be efficiently prevented.

Moreover, the synthetic resin layer 23 has key grooves 22a, 2
Since the protrusions 23a, 23a that engage with the ridges 2b are provided, rattling in the rotational direction is reliably prevented. Further, a key piece 2 is provided in each of the protrusions 23a, 23a.
4 and 25, even if the protrusions 23a and 23a are damaged, the key piece 2
4 and 25, the state in which both shafts 21 and 22 can rotate together is maintained.

[Brief explanation of drawings]

FIG. 1 is a front view of one embodiment of the present invention, and FIG.
The figure and Figure 3 are the - lines and - of Figure 1.
FIG. 4 is an exploded perspective view of an embodiment before the synthetic resin layer 23 is formed, and FIG. 5 is a front view of a conventional device. 20... Telescopic shaft, 21... Inner shaft, 22... Outer shaft, 22a, 22b... Keyway, 23... Synthetic resin layer, 24, 25... Key piece.

Claims (1)

[Claims] 1. An inner shaft is slidably disposed within an outer shaft, and a key mechanism or a spline mechanism is disposed between both shafts, so that both shafts can rotate integrally and extend and contract so that they can move relative to each other. In the flexible shaft, the inner shaft is disposed within the outer shaft with a predetermined gap, the gap is filled with a synthetic resin, the synthetic resin is formed using the inner shaft and the outer shaft as a mold, and the synthetic resin layer is formed. is fixed to the inner shaft, and a clearance is formed between the shaft and the outer shaft due to mold contraction.