JPS6317673B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a steering device that allows a steering wheel to be easily positioned at a normal position.

The steering system for small motorcycles, so-called motorized vehicles, consists of a steering shaft with a front fork at the lower end that is rotatably inserted into the head pipe, and a pivot shaft that rotates together with the handlebar that rotates in the axial direction inside the steering shaft. It is constructed by inserting it into the These pivots and the steering shaft are fixed to each other by tightening a bolt inserted into the pivot, expanding the diameter of the insertion tip of the pivot, and crimping the outer circumferential surface of the pivot to the inner surface of the steering shaft. ing.

By the way, when fixing the steering shaft and the pivot, it is necessary to fix the pivot at a proper position with respect to the steering shaft so that the mounting positions of the handle and the front fork do not deviate from each other. For this reason, a protrusion for positioning is provided on the circumferential surface of the pivot, and
The steering shaft is provided with a fitting groove along the axial direction that opens at one end of the steering shaft.If these protrusions and the fitting groove are fitted into each other and the bolt is tightened, the pivot shaft will be aligned properly with respect to the steering shaft. It is designed to be fixed in position.

However, the groove width between the protrusion and the fitting groove is usually formed to be larger than the outer diameter of the protrusion so that the fitting operation can be easily performed. Even if there is, there will be a backlash between the two along the circumferential direction of the steering shaft. Therefore, when the bolt is tightened, the pivot shaft rotates in the tightening direction of the bolt by the amount described above, and the steering wheel is deviated from the front fork, that is, the steering wheel that is pivotally supported by the front fork moves toward the vehicle body. Although the steering wheel is along the longitudinal direction of the vehicle, there are problems such as the steering wheel being fixed in a state where it is steered to the right with respect to the direction of travel of the vehicle body.

The present invention was made in order to eliminate the above-mentioned problems, and its purpose is to prevent the pivot shaft and the steering shaft from collapsing even though there is play between the protrusion and the fitting receiving part. The object of the present invention is to provide a steering device that can easily and reliably perform positioning.

Therefore, in the present invention, a hollow cylindrical steering shaft that rotates together with the front fork is inserted into the head pipe, and a pivot shaft that rotates together with the steering wheel is inserted into the steering shaft, and the shaft is inserted into the steering shaft. Assuming a steering device in which the fitting end of the pivot shaft is expanded in diameter by tightening a bolt inserted in the direction, and is pressed against the inner surface of the steering shaft, A protrusion is provided on either one of the outer circumferential surfaces, and a fitting receiving part is provided on the other surface along the axial direction into which the protruding part can be fitted with play in the circumferential direction. Either one is provided so as to be offset in the circumferential direction from the normal position where the front fork and the handle are in the same direction, so that when the pivot is rotated in the tightening direction as the bolt is tightened, the protrusion It is characterized in that the circumferential surface and one side of the fitting receiving part are brought into contact with each other, and the pivot shaft is positioned at a normal position where the front fork and the handlebar are aligned with each other with respect to the steering shaft.

The present invention will be explained below based on an embodiment shown in the drawings.

In the figure, 1 is a head pipe that constitutes the frame of a two-wheeled motor vehicle, and a steering shaft 3 is rotatably inserted into the head pipe 1 via ball bearings 2, which have openings at both ends. There is. The steering shaft 3 has a hollow cylindrical shape, and both ends of the steering shaft 3 protrude from the head pipe 1 in the axial direction, and a threaded portion 4 is formed on the circumferential surface of the upper end. The upper ball bearing 2 has an inner race 5 press-fitted into the inner surface of the opening of the head pipe 1, and an outer race 6 screwed onto the threaded portion 4 so as to rotate together with the steering shaft 3. Note that numerals 7 and 7 are nuts that prevent the outer race 6 from loosening. 2 of the threaded portions 4 facing each other
Fitting grooves 8, 8 serving as fitting receiving portions are provided along the axial direction at these locations, and these fitting grooves 8, 8 open at the upper edge of the steering shaft 3.
A front fork (not shown) is attached to the lower end of the steering shaft 3 via an under bracket 9 so as to rotate together with the steering shaft 3.

A hollow cylindrical stem 10 is inserted into the steering shaft 3 as a pivot shaft, and the insertion tip thereof is inserted into the steering shaft 3.
It is in contact with the stepped portion 11 on the inner surface. Therefore, the stem 10 projects from the upper end of the steering shaft 3 in the axial direction. A positioning protrusion 12 is provided on the circumferential surface of the stem 10 so as to protrude into one of the fitting grooves 8 along the groove direction. The outer diameter of this protrusion 12 is the fitting groove 8.
As shown in FIGS. 3 and 4, play along the circumferential direction of the steering shaft 3 is provided between the protrusion 12 and the fitting groove 8. There is. A handle 14 is also welded to a bracket 13 welded to the upper end of the stem 10. Note that 15 is a speedometer, and 16 is a boot that covers the nuts 7, 7.

On the other hand, the inner surface of the lower end of the stem 10 has a tapered surface 17 whose inner diameter increases as it moves downward, and slit grooves 18 are formed along the axial direction at two opposing locations on the lower peripheral surface. , 18 are formed, and these slit grooves 18, 18 open at the lower edge of the stem 10. A bolt 19 is inserted into the stem 10 along the axial direction, and the insertion end of the bolt 19 has the tapered surface 1.
A diameter-expanding member 20 is screwed so as to be located inside the tapered surface 7 and whose circumferential surface is inclined along the tapered surface 17. Therefore, when the bolt 19 is tightened, the circumferential surface of the diameter-expanding member 20 is brought into pressure contact with the tapered surface 17. In this case, since the lower end side circumferential surface of the stem 10 is divided in the radial direction by the slit grooves 18, 18, this circumferential surface is expanded in the radial direction and is crimped onto the inner surface of the steering shaft 3, and these stems 10 and steering shaft 3
are now integrally connected.

Thus, when the protrusion 12 is inserted into the insertion groove 8, it positions the stem 10 and the steering shaft 3, but in the present invention, the protrusion position of the protrusion 12 is set between the front fork and the handle 14. The bolts 19 are deviated toward the direction in which the bolts 19 are tightened, as indicated by arrow A, relative to the normal position where the directions of the bolts 19 coincide with each other. That is, as shown in FIG. 3, the protrusion 12 bolts a line B from its axis toward the center of the stem 10 to a reference line C passing through the widthwise center of the fitting groove 8 and toward the center of the stem 10. The bolt 19 is inclined at an angle of, for example, about 1° toward the tightening direction of the bolt 19, and the circumferential surface of the protrusion 12 and the inner surface of the fitting groove 8 are in contact with each other on the tightening direction side of the bolt 19. There is. In this contact state, the attachment attitude of the handle 14 to the front fork is in the normal position, and the steering shaft 3 and the stem 10 are mutually positioned in the normal position.

According to such a configuration, when fixing the stem 10 to the steering shaft 3, the bolt 19
When tightened, the diameter expanding member 20 comes into pressure contact with the tapered surface 17 at the lower end of the stem 10, so the lower end of the stem 10 is expanded in diameter, and the steering shaft 3
begins to press against the inner surface of the At this time, since there is play between the protrusion 12 and the fitting groove 8 to facilitate the fitting of both, as the bolt 19 is tightened, the stem 10 moves by the amount of play. It tries to rotate in the tightening direction.

However, in the above configuration, the protrusion 12 of the stem 10 is moved in advance from the bolt 19 to the normal position where the front fork and the handlebar 14 are aligned.
is provided so as to be offset in the tightening direction of the bolt 19, so that when the stem 10 is rotated in the tightening direction of the bolt 19 as described above, the circumferential surface of the protrusion 12 is brought into contact with one side of the fitting groove 8. Therefore, this protrusion 12 and the insertion groove 8
In the state where they are in contact with each other, even if the bolt 19 is tightened thereafter, the stem 10 will not rotate together with the bolt 19.

Moreover, when the protrusion 12 and the fitting groove 8 are in contact with each other, the stem 10 and the steering shaft 3
Since the position along the circumferential direction is positioned at the normal position, the stem 10 and the steering shaft 3 are reliably fixed at the normal position even though there is play between the protrusion 12 and the fitting groove 8. can do.

Therefore, there is no need to correct the orientation of the front fork and the handlebar 14 each time the bolt 19 is tightened, and the work of fixing the stem 10 and the steering shaft 3 can be easily performed.

In addition, in the above embodiment, a protrusion was provided on the stem and a fitting groove was provided on the steering shaft, but conversely, a fitting groove may be provided on the stem and a protrusion on the inner surface of the steering shaft. It is also possible to implement the fitting groove in the same manner by deviating the fitting groove in the opposite direction to the direction in which the bolt is tightened.

Further, the fitting receiving portion is not limited to a groove, but may be any recess into which the protrusion can be fitted.

According to the present invention described in detail above, when the protrusion and the fitting receiving part are in contact with each other, the positions along the circumferential direction of the pivot and the steering shaft are positioned at the normal positions, so that the protruding part and the fitting receiving part Even if there is play between the steering shaft and the pivot shaft, the steering shaft and the pivot shaft can be reliably fixed in the correct position by simply tightening the bolts. Therefore, there is no need to correct the orientation of the front fork and the steering wheel each time a bolt is tightened, and there is an advantage that the work of fixing the steering shaft and the pivot can be easily performed.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which FIG. 1 is a cross-sectional view of the whole, FIG. 2 is a cross-sectional view showing a state in which the protrusion and the fitting receiving part are fitted into each other, and FIG. FIG. 4 is a sectional view taken along the line ``--'' in FIG. 2. DESCRIPTION OF SYMBOLS 1... Head pipe, 3... Steering shaft, 8... Fitting receiving part (fitting groove), 10... Pivot (stem), 12... Projection, 14... Handle, 1
9...Bolt.

Claims (1)

[Claims] 1. A hollow cylindrical steering shaft that rotates together with the front fork is inserted into the head pipe, and a pivot shaft that rotates together with the steering wheel is inserted into the steering shaft, and a pivot shaft that rotates together with the steering wheel is inserted into the steering shaft. By tightening the bolt inserted along the direction, the diameter of the insertion tip of the pivot is expanded,
In a steering device that is crimped onto the inner surface of a steering shaft, a protrusion is provided on either the inner surface of the steering shaft or the outer peripheral surface of the pivot shaft, and the protrusion is provided on the other surface with play in the circumferential direction. A fitting receiving part that can be fitted is provided along the axial direction, and either the protruding part or the fitting receiving part is provided circumferentially offset from the normal position where the front fork and the handle are aligned in the same direction, and the above-mentioned When the pivot is rotated in the tightening direction as the bolt is tightened, the circumferential surface of the protrusion and one side of the fitting receptacle are brought into contact with each other, and the pivot is moved between the front fork and the steering wheel against the steering shaft. A steering device characterized in that the steering device is positioned at a regular position with the same orientation.