JPH0679689U - Steering column device - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve the rigidity and vibration characteristics of a steering column device having a structure capable of contracting in the axial direction. [Structure] A jacket tube 1 is supported on a vehicle body by a lower clamp 2 and an upper clamp 3, bearings 5 and 6 are arranged at both ends of the jacket tube 1, and only an upper shaft 8 made of a hollow shaft is rotatably accommodated. The lower shaft 11 is fitted to the upper shaft 8 via the serrations 9 and 12 near the lower clamp 2.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a steering column device for an automobile, and more particularly to a support structure for a steering shaft including an upper shaft and a lower shaft that are engaged with each other by axially contractible engagement with serrations.

[0002]

[Prior art]

 In the case of a vehicle frontal collision accident, when the driver's occupant moves forward and collides with the steering wheel, the steering column device of the automobile moves the steering wheel forward and absorbs the impact. A structure that shrinks in the direction is adopted. The contraction structure of the steering shaft is a two-piece construction consisting of an upper shaft and a lower shaft, which are fitted together in the axial direction by serrations or splines.

However, since the steering shaft is coaxially housed in the jacket tube supported by a clamp on the vehicle body, the jacket tube is composed of the upper jacket tube housing the upper shaft and the lower jacket tube housing the lower shaft. And they are partially fitted so as to be contractible in the axial direction. The upper jacket tube is an upper clamp that can be detached from the vehicle body, and the lower jacket tube is a lower clamp that is fixed to the vehicle body.

Furthermore, since the steering shaft rotates about the axis within the jacket tube, a bearing is interposed between the steering shaft and the jacket tube. The bearings are arranged at the upper end of the upper jacket tube and the lower end of the lower jacket tube, respectively.

[0005]

[Problems to be Solved by the Invention] However, the jacket tube has a two-piece structure that can be contracted in the axial direction, and an upper shaft is provided for the upper jacket tube, a lower shaft is provided for the lower jacket tube, and the shaft center is provided through bearings. Since the steering shaft is a cantilever structure when it is rotatably supported by, the fitting parts of the jacket tube and the steering shaft are weak against the load in the radial direction.

[0006] Therefore, the rigidity of the serration fitting portion at the intermediate portion between the bearings arranged at the upper end portion of the upper jacket tube and the bearings arranged at the lower end portion of the lower jacket tube decreases, and the vibration characteristics tend to deteriorate. In addition, the structure of the steering column device is complicated, and the number of parts is large, resulting in an increase in cost.

Therefore, an object of the present invention is to improve the rigidity and vibration characteristics of a steering column device having a structure capable of contracting in the axial direction.

[0008]

[Means for Solving the Problems]

 In the steering column device according to the present invention, a jacket tube consisting of a hollow shaft is supported on the vehicle body by an upper clamp and a lower clamp arranged at the lower end, and an upper shaft that is axially inserted into the jacket tube is hollow shaft. The upper shaft is formed with serrations or splines on the inner peripheral surface of the lower end of the upper shaft at a predetermined length in the axial direction, and the upper end is reduced in diameter so that the steering wheel can be axially attached. The upper end of the tube is rotatably supported via a bearing, and the lower end is rotatably accommodated in the lower end of the jacket tube via a bearing and is axially inserted into the lower end of the upper shaft. Serrations or splines should be provided on the outer peripheral surface of the upper end of the lower shaft with a specified length in the axial direction. And it features.

[0009]

[Action]

 Since only the upper shaft is rotatably supported about the shaft center by bearings arranged at both ends of the jacket tube, the upper shaft has a double-sided structure with high rigidity, and furthermore, the serration of the upper shaft and the lower shaft is performed. Since the engaging portion is located in the vicinity of the lower clamp, the lower shaft is inserted into the lower end portion of the upper shaft which is supported with high rigidity, and effectively prevents lowering of rigidity.

[0010]

【Example】

 An embodiment of this invention will be described below with reference to the drawings. As shown in FIG. 1, a jacket tube 1 is a hollow shaft having a predetermined length, and a lower end portion of a front side of a vehicle is supported by a lower clamp 2 having an energy absorbing function fixed to a vehicle body, The vicinity of the central portion is supported by an upper clamp 3 which is detachably engaged with and fixed to the vehicle body. Inside the upper clamp 3, there is arranged a distance bracket 4 which is connected to the jacket tube 1 and is vertically movable.

Bearings 5 and 6 are fixed to both ends of the jacket tube 1, and a steering shaft 7 coaxially and rotatably inserted into the jacket tube 1 has an upper shaft composed of a hollow shaft slightly longer than the jacket tube 1. The lower end of the shaft 8 is housed without protruding from the lower end of the jacket tube 1. The upper shaft 8 is provided with serrations 9 or splines on the inner peripheral surface of a lower end 8a having a predetermined length in the axial direction by a predetermined length, and then an upper portion having a predetermined length is expanded to form a diameter expansion portion 8b. At the same time, the diameter of the upper end is reduced so that the steering wheel can be axially attached to form a reduced diameter portion 8c. At the tip of the reduced diameter portion 8c, a serration and a screw portion 10 for pivotally mounting a steering wheel (not shown) are formed.

On the other hand, the lower shaft 11 fitted in the upper shaft 8 in the axial direction has a diameter increased at its upper end portion, and a serration 12 engaging with the serration 9 is engraved on the outer peripheral surface thereof with a predetermined length. The upper shaft 8 and the lower shaft 11 engage with each other via the serrations 12 so as to be contractible in the axial direction. The lower end portion of the lower shaft 11 has a diameter smaller than that of the upper end portion, and an intermediate shaft (not shown) is connected to the lower shaft 11 via the universal joint portion 14. Therefore, the serrations 9 and 12 are located near the lower end of the jacket tube 1, and the upper shaft 8 and the lower shaft 11 are engaged with each other in the axial direction so as to be contractible in the vicinity of the lower clamp 2.

The resin molds 15 and 15 are injected into the engaging portions of the serrations 9 and 12 at a constant interval. The resin molds 15 and 15 are provided with through holes 16 and 16 at the lower end portion of the upper shaft 8 and the resin is injected from the through holes 16 so that the resin is interposed between the serrations 9 and 12 and the serrations 9 and 15. It prevents rattling (misalignment) of 12 and prevents the upper shaft 8 and the lower shaft 11 from moving in the axial direction by generating a predetermined frictional force except when the steering shaft 7 contracts. is there.

As shown in FIGS. 2 and 3, the upper clamp 3 has a plate 31 integrated with an inverted U-shaped bracket 30 that holds the distance bracket 4 fixed to the jacket tube 1 by welding. Are connected to each other. The bracket 30 has a vertically elongated hole 34 into which a tightening bolt 33 penetrating the distance bracket 4 is inserted. The tightening bolt 33 has a rotation stopper member 35 and a tightening block 36 fitted at the ends, and a screw portion 38 to which a tightening nut 37 is screwed is formed on the tightening block 36 side. An operating lever 39 is connected integrally with the nut 37. The plate 31 has a substantially triangular notch 41 into which a slide block 40 that penetrates a bolt for fixing to the vehicle body is detachably fitted. The notch 41 is open to the steering wheel side.

Further, as shown in FIGS. 2 and 4, the lower clamp 2 rotatably holds a bracket 18, which is fixed to the jacket tube 1 and has a U-shaped cross section in plan view, by shafts 19 and 19. It includes a bracket 20 having a U-shaped front cross section, an energy absorbing member 21 integrally formed with the bracket 20, and a plate 22 in which the energy absorbing member 21 is connected by pivot welding or the like. The plate 22 is a rectangular plate having through holes 23, 23 through which bolts for fixing to the vehicle body pass, and square holes 25 with which the hook portions 24, 24 of the energy absorbing member 21 engage on the left and right of the upper surface. , 25 are formed. The energy absorbing member 21 has a bent portion 27 formed in a central portion of a substantially rectangular metal plate 26, which has a U-shaped cross section, and is formed on both left and right sides of the bent portion 27. Vertically bent hook portions 24 are formed.

In FIGS. 1 and 2, reference numeral 42 denotes a key lock unit which is connected to the jacket tube 1 in a crossed manner, and a through hole for locking is formed in the upper shaft 8 in the axial direction. There is.

The operation of the above embodiment will be described. When the steering wheel is rotated, the upper shaft 8 rotates about its axis, and the lower shaft 11 rotates via the serrations 9 and 12. Since the fitting portion between the lower shaft 11 and the upper shaft 8 is engaged almost directly under the lower clamp 2, it is supported with high rigidity without being subjected to a radial load.

Therefore, in FIG. 1, when an occupant collides with the steering wheel and the steering shaft 7 receives a load input F in the direction of the arrow, the resin molds 15 and 15 are broken and the upper shaft 8 moves to the lower shaft 9 side. Then, the steering shaft 7 contracts. The upper end of the lower shaft 11 having the serration 9 moves into the enlarged diameter portion 8b of the upper shaft 8 and the reduced lower end moves into the serration 9 to form a contraction stroke.

Therefore, a load is input to the jacket tube 1 via the bearing 5, and a load is input from the jacket tube 1 to the upper shaft 8 via the tightening bolt 33, whereby the upper clamp 3 is separated from the slide blocks 40, 40. To do. Further, the energy absorbing member 21 is curled at the bent portion 27 first through the bracket 18 connected to the lower end portion of the jacket tube 1, and then the plate is torn from the base of the bent portion 27. To absorb energy.

At this time, since the lower clamp 2 covers the upper surface of the energy absorbing member 21 and the metal plate 26 of the energy absorbing member 21 is fixed to the lower clamp 2 by pivot welding, the metal plate 26 is turned up. Without going up, smooth ripping is done under the guidance of the lower lamp 2. A roller may be interposed in the bent portion 27 in order to stabilize the curling action of the energy absorbing member 21.

Further, since the diameter of the upper shaft 8 above the fitting portion is expanded and the diameter of the lower shaft 11 below is reduced, there is no risk of adversely affecting the contraction stroke of the steering shaft, and any contraction stroke is possible. It enables various settings.

[0022]

[Effect of device]

 According to the invention described above, the jacket tube is supported on the vehicle body by the upper clamp and the lower clamp, the bearings are arranged at both ends of the jacket tube to rotatably accommodate only the upper shaft, and The rigidity of the fitting part was improved by fitting the lower shaft to the upper shaft through a selection near the clamp, so that there is no part that becomes weak against the load in the radial direction and the steering column that can contract in the axial direction. The rigidity is improved.

Therefore, the vibration characteristic of the steering column device is improved, the number of parts of the steering column device is reduced, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a half sectional side view of a steering column device showing an embodiment of the present invention.

FIG. 2 is a plan view of an essential part of FIG.

3 is a sectional view taken along the line AA of FIG.

4 is a sectional view taken along line BB of FIG.

[Explanation of symbols]

 1 ... jacket tube 2 ... lower clamp 3 ... upper clamp 5,6 ... bearing 7 ... steering shaft 8 ... upper shaft 8a ... lower end 8b ... expanding part 8c ... reducing part 9,12 ... serration 11 ... lower shaft

Claims (1)

[Scope of utility model registration request] 1. A jacket tube made of a hollow shaft is supported on a vehicle body by an upper clamp and a lower clamp arranged at a lower end, and an upper shaft for axially inserting into the jacket tube is formed by the hollow shaft. A serration or spline is formed on the inner peripheral surface of the lower end of the upper shaft in a predetermined length in the axial direction, and the upper end is reduced in diameter so that the steering wheel can be axially attached. The lower shaft is rotatably supported via a bearing, the lower end is rotatably housed in the lower end of the jacket tube via a bearing, and the outer periphery of the upper end of the lower shaft is inserted axially into the lower end of the upper shaft. Steering column device characterized in that serrations or splines are engraved on the surface in a predetermined length in the axial direction. .