JP2012051384A - Telescopic shaft for vehicle steering - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent a male shaft from slipping out of a female shaft.SOLUTION: The female shaft 6 includes a spiral groove 6c including an end part of a shaft end inner peripheral surface as an inlet and a circumferential groove 6b continuous to the spiral groove 6c on the shaft end inner peripheral surface expanded in diameter to be larger than a large diameter of a male spline fitting part of the fitted male shaft 5. A spiral C-shaped snap ring 30 of about one round is inserted from the spiral groove 6c, while being twisted, and is fitted in the circumferential groove 6b, and the snap ring 30 therefore is compressed and is fixed, while bracing, in the circumferential groove 6b. Since an inner diameter of the snap ring 30 is smaller than an outer diameter of a male spline sliding part of the male shaft 5, the male shaft 5 can be prevented from slipping out of the female shaft 6.

Description

  In the present invention, a male shaft and a female shaft are fitted to each other and incorporated into a steering shaft of a vehicle, and the male shaft is fitted in a non-rotatable and slidable manner with respect to the female shaft. The present invention relates to a telescopic shaft for vehicle steering that is an intermediate shaft.

  The telescopic shaft of an automobile steering mechanism, for example, an intermediate shaft, is required to have a performance that absorbs axial displacement generated when the automobile travels and does not transmit the displacement or vibration on the steering wheel. .

  For this reason, in the telescopic shaft (intermediate shaft), the male shaft and the female shaft are fitted in a non-rotatable and slidable manner, for example, spline fitting and serration fitting.

  In this case, the telescopic shaft (intermediate shaft) is required to reduce rattling noise, to reduce the rattling on the steering wheel, and to reduce the sliding resistance during the axial sliding operation. ing.

  Further, as disclosed in Patent Document 1, in the intermediate shaft (extensible shaft), a clip which is a retaining member is attached to the end of the female shaft, and the spline slide of the male shaft is attached to this clip. Thus, the male shaft is prevented from falling out of the female shaft and falling off.

JP-A-11-230184

  In the disclosed example of Patent Document 1, there is an outer peripheral groove on the outer peripheral surface of the end of the female shaft, and a clip is mounted there, and the protrusion on the inner periphery of the clip contacts the large diameter of the male shaft to prevent the shaft from coming off. ing. However, when the female shaft outer peripheral groove is processed, the inner diameter of the spline is reduced by a processing load from the outer periphery, and the sliding force may vary, and it is difficult to set the processing conditions for the outer peripheral groove. Further, since the retaining ring is mounted on the outer peripheral surface of the female shaft, the clip is frequently dropped due to a collision during the assembly work.

  The present invention has been made in view of the circumstances as described above, and by attaching a retaining ring used for retaining the spline sliding portion to the inner peripheral surface of the female shaft, it is assembled without impairing slidability. It is an object of the present invention to provide a telescopic shaft for vehicle steering having a feature that a retaining ring is difficult to fall off during transportation.

  In order to achieve the above object, a telescopic shaft for vehicle steering according to claim 1 of the present invention is incorporated in a steering shaft of a vehicle by fitting a male shaft and a female shaft to each other, and the male shaft is connected to a female shaft. In the telescopic shaft for vehicle steering that fits in a relatively non-rotatable and slidable manner, the female shaft is a shaft end inner peripheral surface that is larger than the large diameter of the male shaft of the fitting portion. , Equipped with a spiral groove with its end as an inlet and a circumferential groove connected to it, inserting a spiral C-shaped retaining ring of substantially one round while twisting from the spiral groove, and mounting to the circumferential groove By doing so, the male shaft is prevented from coming out of the female shaft.

The spiral groove and the inner peripheral groove are provided in the part where the inner diameter of the female shaft end is larger than the outer diameter of the sliding part of the male shaft. It is possible to prevent the sliding from worsening. Further, since the spiral groove and the inner peripheral groove are provided in the expanded diameter portion, the influence of deformation during the groove processing on the female spline shape is reduced, so that the sliding force can be prevented from deteriorating.
Furthermore, in the present invention, since the retaining ring is attached to the inner peripheral surface of the female shaft, there is an effect that the dropout due to the collision during the assembly work to the vehicle does not occur.

1 is a side view of a steering mechanism portion of an automobile to which a telescopic shaft for vehicle steering according to an embodiment of the present invention is applied. It is a fragmentary longitudinal cross-sectional view of the 1st Example which shows the intermediate | middle shaft (expansion / contraction axis) of the X section of FIG. It is a fragmentary perspective view which shows the inner peripheral part of the edge part by which the pipe expansion molding of the female shaft of the 1st Example was carried out. It is a perspective view which shows various retaining rings. It is the whole perspective view which described the assembly method of the retaining ring to a female shaft. It is a principal part enlarged view which shows a 1st Example. It is a principal part enlarged view which shows a 2nd Example.

  Hereinafter, a telescopic shaft for vehicle steering according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a side view of a steering mechanism portion of an automobile to which a vehicle steering telescopic shaft according to an embodiment of the present invention is applied.

  In FIG. 1, a steering shaft 2 is rotatably supported on a steering column 1, and a steering wheel 3 is attached to the rear end of the steering shaft 2.

  Connected to the front end of the steering shaft 3 through a universal joint 4 is an intermediate shaft (extensible shaft) 7 in which the male shaft 5 and the female shaft 6 are fitted so as not to rotate relative to each other and to be slidable.

  A steering gear 9 is connected to the front end of the intermediate shaft (extensible shaft) 7 via a universal joint 8. The female shaft 6 of the intermediate shaft (extensible shaft) 7 is attached to the dashboard 10 via a seal member 11 or the like.

  FIG. 2 is a partial vertical cross-sectional view of the first embodiment showing an intermediate shaft (expandable shaft) in the X part of FIG. FIG. 3 is a partial perspective view showing an inner peripheral portion of the end portion of the intermediate shaft (expandable shaft) of FIG. FIG. 4 is a perspective view showing various retaining rings.

  FIG. 5 is an overall perspective view showing a method of assembling the retaining ring to the female shaft. FIG. 6 is an enlarged view of a main part showing a first embodiment showing a mounting state of the retaining ring. FIG. 7 is an enlarged view of a main part showing the second embodiment.

  As shown in FIGS. 2, 3 and 5, a female spline 6a is formed on the inner peripheral surface of the female shaft 6, and the male shaft 5 is a spline slide having a male spline formed on the outer peripheral surface thereof. And a shaft portion 21 having a diameter smaller than that of the spline sliding portion 20, and the spline sliding portion 20 of the male shaft 5 is coated with a resin and further has a spline-shaped exposed portion 20a. Yes. Resin is coated on the exposed portion 20a to prevent the play in the rotational direction of the steering shaft system while reducing the sliding force while ensuring the strength of the steering shaft system. Here, the male shaft 5 may have no exposed portion 20a and the entire spline may be resin-coated.

  The female shaft 6 has a retaining ring in a circumferential groove 6b formed on the inner peripheral surface of the end portion of the diameter-expanded portion 62 of the female shaft 6 as a retaining member for preventing the male shaft 5 from coming out. 30 is installed. As shown in FIG. 4, the retaining ring 30 has a spiral C-shape that is substantially one round, and its inner diameter is smaller than the outer diameter of the spline sliding portion 20 of the male shaft 5. When pulling out from the male shaft 5, the outer diameter of the male shaft 5 spline abuts against the inner diameter of the clip 30, thereby preventing the shaft from coming off.

  As shown in FIGS. 3 and 5, the spiral groove 6 c having the end portion as an inlet is continuously formed on the inner peripheral surface of the end portion of the diameter-expanded portion 62 of the female shaft 6 which has been expanded. It is provided to do. The outer diameter of the spiral groove 6c is a height that allows the retaining ring 30 to pass through, and the retaining ring 30 is inserted into the spiral groove 6c from the end of the female shaft 6.

  The spiral groove 6c and the circumferential groove 6b are cut after the small diameter portion 61 is expanded and the expanded diameter portion 62 is formed. Thereafter, the female spline 6a is formed (drawing, extruding, etc.), so that it can be processed while removing large burrs around the grooves that hinder sliding. Further, the small burr does not affect the sliding because the diameter of the female shaft 6 is enlarged.

  As shown in FIG. 5, when the retaining ring 30 is inserted into the spiral groove 6c from the end of the female shaft 6 and rotated in the T direction, the retaining ring 30 reaches the circumferential groove 6b and further rotates in the T direction. In this case, the retaining ring 30 is fixed while being stretched by compressing the free length S (see FIG. 4) between the axial surfaces 6b ′ and 6b ′ of the circumferential groove 6b. As a result, it is possible to prevent displacement due to vibration and dropout due to a collision during assembly work.

  Further, as shown in FIG. 6, the retaining ring 30 of this embodiment is a retaining ring 30b having a rectangular cross section obtained by press-punching a plate material. However, as shown in FIG. A retaining ring 30c having an oval cross section that is crushed up and down may be used. The fixing force of the retaining ring 30 in the circumferential groove can be adjusted by appropriately combining the retaining ring 30 and the distance between the axial surfaces 6b 'and 6b' of the circumferential groove 6b.

  FIG. 7 is an enlarged view of a main part showing the second embodiment. In the second embodiment, instead of providing the enlarged diameter portion 62 at the end of the female shaft, an enlarged inner diameter portion 63 for boring with a larger diameter than the outer diameter of the male spline sliding portion 20 is provided.

  Similarly to the first embodiment, the second embodiment forms the female spline 6a after processing the enlarged inner diameter portion 63, so that it can be processed while removing large burrs around the groove that inhibits sliding. it can. Further, the small burr does not affect the sliding because the diameter of the female shaft 6 is enlarged.

  The present invention prevents the slidable telescopic shaft from slipping out, and can be applied mainly to a steering mechanism portion of an automobile.

DESCRIPTION OF SYMBOLS 1 Steering column 2 Steering shaft 3 Steering wheel 4 Universal joint 5 Male shaft 6 Female shaft 6a Female spline 6b Circumferential groove 6c Spiral groove 61 Small diameter part 62 Expanded diameter part 63 Expanded inner diameter part 7 Intermediate shaft (telescopic shaft)
8 Universal joint 9 Steering gear 10 Dashboard 11 Seal member 20 Male spline sliding part 20a Exposed part (background part)
21 Shaft part 30, 30a, 30b, 30c Retaining ring

Claims (1)

A male shaft and a female shaft are fitted to each other and incorporated in a vehicle steering shaft. The male shaft has a sliding portion that is slidably fitted to the female shaft so as not to rotate relative to the female shaft. In the shaft, the female shaft is formed on a shaft end inner peripheral surface whose diameter is larger than the large diameter of the male shaft of the fitting portion, a spiral groove having the end portion as an inlet, and a circumferential groove connected to the spiral groove. A spiral C-shaped retaining ring having a substantially round circumference is inserted while being twisted from the spiral groove and is attached to the circumferential groove, thereby preventing the male shaft from slipping out of the female shaft. A telescopic shaft for vehicle steering.

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