JP2872989B1 - Vehicle steering system - Google Patents

Abstract

An object of the present invention is to firmly fix a connecting pipe of a handle to an upper end of a steering shaft of a vehicle and to reduce the number of man-hours during an assembling operation. In a steering wheel in which a connecting pipe (22) of a handle portion is fitted and connected to a steering shaft (1) fixed to a front fork supporting a front wheel, a radial through hole (23) is provided in the connecting pipe (22). A radial screw insertion hole 12 is formed in the steering shaft 1 and the screw insertion hole 1
2, a flat seating surface 13 orthogonal to the screw insertion hole 12 is formed, and the screw body 30 is screwed into the screw hole 24 through the screw insertion hole 12, thereby forming the screw body 30. The collar portion 31 connected to the head 30a is pressed against the seating surface 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering device for attaching a handle shaft to an upper end of a steering shaft in a vehicle such as a motorcycle.

[0002]

2. Description of the Related Art A structure shown in FIG. 6 is known as a structure for fixing a connecting pipe of a handle portion to an upper end of a steering shaft in a relatively small-sized motorcycle steering apparatus such as a so-called moped type. Japanese Utility Model Laid-Open No. 63-16284 discloses a related technique.

[0003] In the structure shown in Fig. 6, a keyway 2 (Fig. 8) is formed in the upper end surface 1A of a steering shaft 1 connected to a front fork (not shown). A pin 3 fitted in the key groove 2 is fixed by welding or the like, and a split groove 4 in the axial direction is provided at a distal end portion 5A, so that the steering shaft is fitted in the key groove 2 (FIG. 8). After the connecting pipe 5 is fitted to the outside of the connecting pipe 5 and fully inserted, a tightening member 6 is fitted and welded to a distal end portion 5A of the connecting pipe 5 provided with a split groove 4 as shown in FIG. In this configuration, the steering shaft 1 is prevented from falling out of the connecting pipe 5 and is prevented from rotating.

[0004]

When the connecting pipe 5 is fitted to the steering shaft 1, in order to improve workability, the keyway 2 is usually exaggerated as shown in FIG.
Is larger than the outer diameter d of the pin 3.

For this reason, the relative rotation between the steering shaft 1 and the connecting pipe 2 cannot be completely prevented only by tightening with the bolts and nuts 7. (B−d>
0) results in a relative rotation R as shown by the dotted line in FIG. This relative rotation is slight around the steering shaft 1, but the radius of rotation becomes large at the tip of the handle, so that the deviation in the rotation direction is amplified.

In addition, in the case of the above structure, when assembling the steering wheel, it is necessary to attach the connecting pipe 5 to the steering shaft 1, then weld the tightening member 6 and tighten the bolt and nut 7, so that the number of working steps is large. In addition, the number of components increases by the amount of the pins 3 and the tightening members 6.

The present invention solves the above-mentioned problems, and fixes a steering shaft and a connecting pipe of a steering wheel so that they cannot rotate relative to each other.
In addition, it is an object of the present invention to provide a vehicle steering device capable of reducing the number of parts and the number of work steps during assembly work.

[0008]

According to a first aspect of the present invention, there is provided a steering apparatus for a vehicle, wherein a connecting pipe fitted and connected to a steering shaft is provided with a radial screw hole.
A radial screw insertion hole is formed in the steering shaft, and a seating surface is formed at one end of the screw insertion hole and formed of a plane orthogonal to the screw insertion hole, and the screw body passes through the screw insertion hole. By being screwed into the screw hole, the collar portion connected to the head of the screw body is pressed against the seating surface.

According to this structure, the head of the screw that passes through the steering shaft and is screwed to the connecting pipe is pressed against the flat seat surface formed on the steering shaft, so that the steering shaft and the connecting pipe are relatively positioned. Rotation can be prevented.

[0010] Further, since the above-mentioned fastening structure prevents relative movement in the axial direction, pins and tightening members as in the prior art are not required, so that the number of parts and work processes are reduced, and productivity is improved. I do.

According to a second aspect of the present invention, the screw hole according to the first aspect is formed by a welding nut provided in the connecting pipe. According to this configuration, it is not necessary to form a boss portion for providing a screw hole in the connecting pipe, so that a standard straight pipe can be used as the connecting pipe, and cost reduction is realized.

[0012]

Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an exploded side view, partially broken away, showing a main part of a vehicle steering system according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of a main part showing a state in which the vehicle steering system is assembled. It is.

In FIG. 1, a steering shaft 1 is connected via a bracket 11 to a front fork 10 supporting a front wheel (not shown). The handle part 20 is composed of a handlebar 21 and a connecting pipe 2 fixed at the center thereof.
And 2. The connecting pipe 22 is provided with radial through holes 23 </ b> A and 23 </ b> B concentrically, and a nut 24 located opposite the through hole 23 </ b> A on one side (in this example, the rear side) is welded to the connecting pipe 22. ing. The inner diameter of the through hole 23B on the other side is formed to be larger than the diameter of the through hole 23A on the one side, and the collar portion 31 fitted under the head 30a of the screw 30 screwed into the screw hole 25 of the nut 24 is formed. The diameter is such that it can be inserted.

The steering shaft 1 connected to the connecting pipe 22 is a solid shaft in the illustrated example.
A screw hole 12 in the radial direction, and a flat seating surface 13 orthogonal to the screw hole 12 at one end of the screw hole 12.
Are formed.

After fitting the connecting pipe 22 to the outside of the steering shaft 1 as shown by the arrow X, a screw 30 such as a bolt is inserted into the screw hole 25 through the screw insertion hole 12 as shown in FIG. The collar portion 31 is pressed against the flat seating surface 13 by the screwing and the pressing force of the head portion 30a of the screw body 30.

As shown in FIG. 3, a head pipe 18 is fixed to the front end of the body frame 17, and the steering shaft 1 is rotatably supported by the head pipe 18 via thrust bearings 15, 16. Heavy nuts 20, 21
Thus, the upper bearing 15 is prevented from falling off.

In the above-described steering apparatus for a vehicle, the screw portion 30 is strongly tightened so that the collar portion 31 is attached to the flat seating surface 13 via the head portion 30a of the screw member 30 as shown in FIG. Since the steering shaft 1 is strongly pressed, the steering shaft 1 is strongly pressed against the inner surface of the connecting pipe 22, and is firmly held between the inner surface of the connecting pipe 22 and the collar portion 31. There is no relative rotation. Further, since the screw body 30 is inserted into the screw insertion hole 12 of the steering shaft 1, the connection pipe 22 is prevented from coming off in the axial direction with respect to the steering shaft 1.

On the other hand, when the end surface of the collar portion 31 is pressed against the steering shaft 1 without providing the flat seating surface 13 on the steering shaft 1, as shown in FIG.
The steering shaft 1 in the connecting pipe 22 is
Due to a difference in diameter between the screw body 2 and the screw body 30, there is a possibility of relative rotation as shown by an arrow R1, and the seating surface 1 of FIG.
3 prevents such relative rotation.

In the case where a nut is used as the screw hole 25, as shown in FIG. 4B, unless the nut 24A is fixed to the connecting pipe 22 by welding or the like, the connecting pipe 22 is connected to the through hole 23B and the collar portion 11 by the welding. Due to the difference in diameter between them, there is a possibility of relative rotation as indicated by an arrow R2, and the welding nut 24 of FIG. 2 of the present invention prevents such relative rotation.

As described above, the structure in which the screw body 30 is fastened between the flat seating surface 13 and the welding nut 24 has the following features.
Since the steering shaft 1 and the connecting pipe 22 can be firmly connected and fixed, the pin 3 and the tightening member 6 attached to the conventional connecting pipe 5 shown in FIG.

In the above embodiment, the welding nut 24 is used to provide the screw hole 25 in the connecting pipe 22 shown in FIG. 2, but as shown in FIG.
b may be integrally formed, and the screw hole 25 may be formed in the boss portion 22b.

In addition to using a normal bolt as shown in the figure, an Allen bolt having a long bolt head axial length can also be used as the screw body 30. In this case, since the lower portion of the Allen bolt head also serves as the collar portion 31, the collar portion 31 is not required as a separate component, and the number of components is reduced.

[0023]

As described above, according to the present invention, the head of the screw body for fastening the steering shaft and the connecting pipe is
The two are firmly connected to each other because they are pressed against the flat seating surface formed on the steering shaft. Also, since the connection is made firmly only by fastening the screw body, the pins and tightening members of the connecting pipe, which were required in the past, are unnecessary, so the number of parts is smaller than in the conventional steering device of the vehicle, and the assembly work is also easier. Simplified.

[Brief description of the drawings]

FIG. 1 is an exploded side view, partially broken away, showing a vehicle steering system according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part showing a state where the steering device is assembled.

FIG. 3 is a longitudinal sectional view showing an assembled state of the steering device.

4A and 4B show a comparative example, in which FIG. 4A is a cross-sectional view showing a case where a flat seat is not provided on a steering shaft, and FIG. 4B is a cross-sectional view showing a case where a nut is not welded.

FIG. 5 is a cross-sectional view of a main part of a vehicle steering apparatus according to another embodiment of the present invention.

FIG. 6 is a longitudinal sectional view of a main part showing a conventional vehicle steering apparatus.

FIG. 7 is a front view of a main part showing a conventional vehicle steering device.

FIG. 8 is a cross-sectional view showing a main part of a conventional vehicle steering device.

[Explanation of symbols]

1 ... steering shaft, 10 ... front fork, 11 ...
Bracket, 12: insertion hole, 13: flat seating surface, 20
... handle part, 21 ... handlebar, 22 ... connecting pipe, 23 ... radial through hole, 23A ... one side through hole,
23B: other side through hole, 24: nut, 25: screw hole, 30: screw, 30a: screw head, 31: collar part

Claims (2)

(57) [Claims] 1. A steering device comprising a steering shaft fixed to a front fork supporting a front wheel and a connecting pipe of a handle part fitted and connected thereto, wherein the connecting pipe is provided with a radial screw hole, The shaft is formed with a radial screw insertion hole and a flat seating surface located at one end of the screw insertion hole and orthogonal to the screw insertion hole, and the screw body passes through the screw insertion hole. A steering device for a vehicle, wherein a collar portion connected to a head of a screw body is pressed against the seat surface by being screwed into the screw hole. 2. The vehicle steering apparatus according to claim 1, wherein the screw hole is formed by a welding nut provided in a connecting pipe.