JPH1122823A - Gear shift mechanism of transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate an impact load applied to a fork support shaft at shift finish time by arranging stoppers with which a shift lever comes into contact on the shift rotation end of the shift lever, in an upper cover housing. SOLUTION: Stoppers 13a and 13b with which a shift lever 5 comes into contact on the shift rotation end of the shift lever 5, are arranged in an upper cover housing 6. In shift actuation of the shift lever 5 by rotation of a shift select shaft 4, the shift lever 5 is regulated by coming into contact with the stoppers 13a and 13b on its rotation end. Therefore, an impact load is not applied to a fork support shaft at shift finish time, and impact force does not act on a first pin and a second pin arranged in the fork support shaft. The action of a bending load on the fork support shaft by shift force can also be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear shift mechanism for a transmission that eliminates an impact load applied to a fork support shaft at the end of a shift.

[0002]

2. Description of the Related Art As shown in FIG. 4, a gear shift mechanism of a transmission has a fork support shaft 2 supporting a fork 2a in a case of a transmission 1 movably in an axial direction (shift). A shift select shaft 4 that rotates around an axis orthogonal to the fork support shaft 2.
The shift lever 5 provided with the shift claw 5a on the select shaft 4 is integrally rotated in the rotation direction by spline fitting, and is slidably supported in the axial direction. The fork support shaft 2 is shifted by the shift claw 5a via the fork 2a, and the select operation is performed by moving the shift lever 5 in the axial direction.

As shown in FIG. 5, the fork support shaft 2 shifted by the shift lever 5 has a first pin 8 for coupling the fork 2a and the fork support shaft 2, and a lower half for regulating the shift end. A stopper 10 that contacts the wall 7 is fixed to the end of the fork support shaft 2 by a second pin 9.

[0004]

In the gear shift mechanism of the conventional transmission, an impact load is applied to the fork support shaft 2 at the end of the shift, and the impact force acts on the first pin 8 and the second pin 9, so that the shift is performed. Depending on the output of the cylinder, it was necessary to consider increasing the strength of the first pin 8 and the second pin 9. In addition, as shown in FIG. 6, a bending load acts on the fork support shaft 2 due to the shift force, which may affect the shift operation.

An object of the present invention is to provide a gear shift mechanism for a transmission in which an impact load applied to a fork support shaft at the end of a shift is eliminated and a smooth shift operation is obtained.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a shift lever which is operated in a rotational direction and an axial select operation by a shift / select shaft in an upper cover housing. A stopper is provided in the upper cover housing at a shift rotation end of the shift lever, the stopper being in contact with the shift lever.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 4 denotes a shift / select axis. The shift / select shaft 4 is rotatably supported on the upper cover housing 6 only in the rotational direction.

As shown in FIG. 2, the shift / select shaft 4 is provided with a shift lever 5 having a shift claw 5 which engages with a fork 2a (see FIG. 4) on the fork support shaft 2 by spline fitting. They are integrally rotated and slidably supported in the axial direction.

The shift lever 5 on the shift / select shaft 4 is urged leftward in FIG. 2 by a spring 16, and is selectively operated in the axial direction by a select arm 11 and an operating rod 12. A shift arm (not shown) is connected to the end of the shift / select shaft 4 to shift the shift / select shaft 4 in the rotation direction.

As shown in FIG. 4, the shift / select shaft 4 is rotated by a shift lever 5 which rotates about an axis perpendicular to the fork support shaft 2, so that the fork support shaft 2 moves and shifts in the axial direction. .

Therefore, in the present invention, stoppers 13a and 13b are provided in the upper cover housing 6 at the shift rotation end of the shift lever 5 so that the shift lever 5 abuts.

As shown in FIGS. 1 and 2, the stoppers 13a and 13b have a configuration in which a protrusion is provided at a predetermined position inside the upper cover housing 6.

Further, as shown in FIG. 3, a stopper 13a, 13b may be provided on the screw shaft 14 and fixed to the upper cover housing 6 by a nut 15 screwed to the screw shaft 14. In this case, the height of the stoppers 13a and 13b due to the protrusion is fixed, but the nut 1
5, the height H of the stoppers 13a and 13b can be adjusted arbitrarily and appropriately.

Since the present invention has the structure as described above, in the shifting operation of the shift lever 5 by the rotation of the shift / select shaft 4, the shift lever 5 comes into contact with the stoppers 13a and 13b at the rotation end thereof and is regulated. .

Therefore, no impact load is applied to the fork support shaft 2 at the end of the shift, and an impact force acts on the first pin 8 and the second pin 9 provided on the fork support shaft 2. Absent. In addition, the effect of the bending load on the fork support shaft 2 due to the shift force is also eliminated.

[0016]

As described above, according to the present invention, the shift rotation end of the shift lever is regulated by the stopper provided in the upper cover housing, so that the shift lever is attached to the fork support shaft at the end of the shift. The impact load effect is eliminated, and it is no longer necessary to consider the strength of the pin that connects the fork to the fork support shaft, and the number of parts that eliminate the stopper fixed to the fork support shaft is reduced, resulting in a smooth shift operation. It has the advantage that it can be secured.

[Brief description of the drawings]

FIG. 1 is a sectional view of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG. 1;

FIG. 3 is a sectional view showing an example of a design change of a stopper.

FIG. 4 is a fragmentary sectional view of a transmission.

FIG. 5 is an explanatory view of a problem with a fork support shaft in a conventional mechanism.

FIG. 6 is an explanatory view of another problem of the fork support shaft in the conventional mechanism.

[Explanation of symbols]

 4 shift / select shaft 5 shift lever 5a shift claw 6 upper cover housing 13a stopper 13b stopper

Claims (1)

[Claims] 1. A shift mechanism in an upper cover housing.
A shift lever, which is operated by a select shaft to perform a shift operation in a rotational direction and a select operation in an axial direction, wherein a stopper is provided in the upper cover housing at the shift rotation end of the shift lever so that the shift lever abuts. Gear shift mechanism.