JPS647917B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a steering wheel steering device that can smoothly steer the steering wheel of a motorcycle without rattling.

Prior Art In conventional steering wheel steering devices for motorcycles, in order to attach the steering wheel swing shaft to the head pipe through a bearing so that the handle swing shaft can swing freely without any play, the handlebar swing shaft is screwed onto the handle swing shaft as shown in Fig. 2. The bolts were tightly screwed together and tightened.

For this reason, a large axial tightening force is applied to the angular contact ball bearings installed in the head pipe and the handle swing shaft, and a large load is applied between the outer and inner rings of the angular contact ball bearings and the balls. It was inevitable that the resulting ball impression would be large.

Problems to be Solved From the standpoint of minimizing this ball impression, conventional methods have been to reduce the circumferential spacing between the balls interposed between the outer ring and the inner ring, increase the number of balls, and reduce the tightening load per ball. was made smaller.

However, as shown in FIG. 6, when the outer ring fitted to the head pipe is fixed and the inner ring fitted to the handle swing shaft swings in response to handle operation, the critical swing angle θc (The limit angle at which the indentation formed by one ball in contact with the inner and outer rings does not overlap with the indentation by an adjacent ball) is a concept similar to finding the rotation angle of the sun gear in a planetary gear device with a fixed ring gear. From this, it becomes as follows.

θc=360°/n (1+D+dcosβ/D−dcosβ)……
(1) Where, n is the number of balls D is the inner diameter of the groove contacting part of the outer ring D ₁ and the outer diameter of the groove contacting part of the inner ring D ₂ Average diameter D = D ₁ + D ₁ /2 d is the outer diameter of the ball β is the ball The angle formed by the line connecting the contact points of the inner and outer rings and the rotating surface of the bearing.As is clear from equation (1), this critical swing angle θc becomes smaller as the number of balls n increases,
The maximum steering angle of the steering wheel (normally 50°) is exceeded, and the impressions made by adjacent balls partially overlap.

And because there are variations in the outer diameter of the ball,
Since the depth of the indentation formed by each ball is different, when this critical swing angle θc exceeds the maximum steering angle of the steering wheel, when a ball enters the indentation formed by an adjacent ball, The swing resistance of the handle swing shaft changes in stages.

Means and Effects for Solving the Problems The present invention relates to an improvement of a steering wheel steering device for a motorcycle that eliminates such inconveniences, and provides a steering wheel for a motorcycle in which a steering wheel swing shaft is rocked by an angular ball bearing with a retainer. The steering device is characterized in that the critical swing angle of the angular ball bearing is set larger than the maximum steering angle of the steering wheel swing shaft.

The present invention provides a steering wheel steering device for a motorcycle in which a handlebar swing shaft is oscillated by an angular contact ball bearing with a retainer, in which the critical swing angle of the angular contact ball bearing is set larger than the maximum steering angle of the handlebar swing shaft. When the steering wheel is steered within a normal steering angle, the ball impressions on the contact surfaces of the inner and outer ring grooves of the angular ball bearing can be separated and prevented from overlapping.

Embodiment An embodiment of the present invention illustrated in the drawings of FIGS. 1 to 4 will be described below.

1 is a motorcycle frame, and the frame 1 is
It consists of a head pipe 2, a main pipe 3, a down tube 4, a back pipe 5, and a seat rail 6, which are integrally connected to each other.

Further, an outer ring 8 of an angular ball bearing 7 is fitted to both upper and lower ends of the head pipe 2, and a steering wheel swing shaft 12, which is a steering shaft, is fitted to an inner ring 9 of the bearing 7. A bottom bridge 16 is attached to the lower end, and a nut 13 is screwed to the upper part of the handle swing shaft 12. By tightening the nut 13, the upper and lower parts can be rotated.
The outer rings 8 of the pair of angular ball bearings 7 are press-fitted to the upper and lower ends of the head pipe 2, and the inner rings 9 of the pair of upper and lower angular ball bearings 7 are fixed to the handle swing shaft 12.

Further, a top bridge 15 is fitted to the upper end of the handle swing shaft 12, and by tightening the nut 17, the top bridge 15 is connected to the handle swing shaft 12.
The front fork 14 is fixed to the top bridge 15 and the top bridge 16 in advance, and the front fork 14 is fixed to the top end.
4 is a predetermined angle α of 50° or more about the handle swing axis 12 by a stopper mechanism (not shown).
It is designed to be able to swing within a range of, for example, within 40 degrees left and right.

Furthermore, the base ends of a pair of left and right handle pipes 18 are integrally attached to the top bridge 15, and a handle grip 1 is attached to the tips of the handle pipes 18.
A front wheel 21 is rotatably attached to the front fork 14 via a suspension unit 20.

However, a retainer 11 is interposed between the outer ring 8 and the inner ring 9 of the angular ball bearing 7 to prevent 14 or less balls 10 from coming into contact with each other at equal intervals.

In addition, the critical swing angle θc is set to the above value D ₁ , so that the following relationship holds true: θc>α (2) _D2 , D,
d, n, and β are set.

Specifically, D=36mm, d=7.0mm, n=14,
If β=45°, then θc=59.6° from equation (1), and if set angle α is 50°, equation (2) can be satisfied.

Further, when D=42 mm, d=7.9 mm, n=14, and β=45°, θc=59.4°, which also satisfies equation (2).

The embodiment shown in FIGS. 1 to 4 is constructed as described above, so that when the handle grip 19 is grasped and swung from side to side, the handle swing shaft 12 is connected to the head pipe 2 by an angular ball bearing. 7, it is swung left and right within ±25 degrees, and its center of oscillation coincides with the centers of the head pipe 2 and the handle oscillation shaft 12.

In this case, since the handle swing shaft 12 swings within the critical swing angle θc of the angular ball bearing 7,
Even if the angular ball bearing 7 wears out, the indentations made by one ball 10 rolling on the groove contact surfaces of the outer ring 8 and the inner ring do not overlap with the indentations of the adjacent balls 10, and the handle oscillating shaft 12 The swinging resistance does not change, and the handle can be operated smoothly.

Further, since the balls 10 are held by the retainer 11, the balls 10 will not be lost during assembly and disassembly, and the assembly and disassembly operations can be carried out efficiently and easily.

Further, the ball 10 has an inner ring 8 having a circularly curved groove.
Since the adjacent balls 10 do not come into frictional contact with each other, the swing resistance of the handle swing shaft 12 is small and there is no change in resistance due to contact between the balls.

In the embodiments shown in FIGS. 1 to 4, the retainer 11 is formed by providing holes equally spaced in the same direction in a conical ring, but as shown in FIG. Holes are made in the ring at equal intervals in the same direction, the inner circumference of the ring is bent upward, this is placed on the outer ring 8, the balls 10 are fitted in the holes of the ring, and the inner ring 9 is placed on top of it. After mounting, a retainer 11 may be used in which the outer periphery of the ring is curved toward the center.

Effects of the Invention As described above, in the present invention, the ball impressions on the contact surfaces of the inner and outer ring grooves of the angular shaft ball bearing can be separated and prevented from overlapping, thereby eliminating the influence of resistance change due to the ball impressions. However, the steering feeling of the steering wheel swing shaft can be maintained constant.

[Brief explanation of drawings]

FIG. 1 is a side view of a motorcycle equipped with an embodiment of the steering wheel steering device according to the present invention, and FIG.
A vertical sectional view cut along the - line in the figure, FIG. 3 is an enlarged longitudinal sectional view of the main part, FIG. 4 is a plan view of FIG. 3 with the inner ring removed, and FIG. 5 is another embodiment. FIG. 6 is an explanatory longitudinal sectional view for explaining the critical swing angle. 1... Motorcycle frame, 2... Head pipe, 3... Main pipe, 4... Down tube, 5... Back stay, 6... Seat rail,
7... Angular ball bearing, 8... Outer ring, 9... Inner ring, 10... Ball, 11... Retainer, 12...
...Handle swing axis, 13...Nut, 14...Front fork, 15...Top bridge, 16
...Bottom Bridge, 17...Natsuto, 18...
Handle pipe, 19... Handle grip, 2
0...Suspension unit, 21...Front wheel.

Claims (1)

[Claims] 1. A steering wheel steering device for a motorcycle in which a handlebar swing shaft is oscillated by an angular contact ball bearing with a retainer, characterized in that the critical swing angle of the angular contact ball bearing is set to be larger than the maximum steering angle of the handlebar swing shaft. Handle steering device for motorcycles.