JP2555472Y2 - Misshift prevention device for speed change operation mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a shift operating mechanism of a transmission in which one forward gear and a reverse gear are on the same shift operating line, and the gear is directly shifted from the forward gear to the reverse gear. The present invention relates to a device for preventing misshifting.

[Conventional technology]

Conventionally, a shift operation mechanism in which a shift select lever and a misshift prevention device are provided coaxially, for example, is disclosed in
It is known from the publication 1355.

The shift operation mechanism includes an inner shift lever rotatably supported on a shift lever shaft and movable in the axial direction, a shift guide plate rotatably supported on the shift lever shaft and slidably in the axial direction, A torsion spring biases the shift guide plate in the forward gear shift direction and biases the shift guide plate toward the inner shift lever, and presses the shift guide plate by moving the inner shift lever toward the shift guide plate. A shift portion provided on one of a fixed body or a shift guide plate, and a latch portion of the inner shift lever that engages with the shift guide plate so that the pressing is released by the rotation of the inner shift lever toward the forward stage. The inner shift lever engages with an engaging portion provided on the other of the guide plate or the fixed body to adjust the engagement range between the engaging portion and the shift guide plate. It is from a forward gear that a stopper for restricting the range that leads to a neutral position.

Although not shown in the above publication, components such as a return spring for elastically supporting the inner shift lever at a neutral position and an interlock plate for preventing a double gear are mounted on the shift lever shaft.

[Problems to be solved by the invention]

However, in the case of the above-mentioned misshift prevention device, all the components such as the return spring and the interlock plate, in addition to the inner shift lever, the shift guide plate and the torsion spring, are arranged in series on the shift lever shaft. Not only the size in the direction becomes longer and the speed change operation mechanism becomes larger, but also the support rigidity of the shift lever shaft is reduced, and play between the components is likely to occur due to the bending of the shift lever shaft.

SUMMARY OF THE INVENTION An object of the present invention is to provide a device for preventing a shift operation mechanism of a shift operation mechanism, in which components can be compactly arranged on a shift shaft and the support rigidity of the shift shaft is improved.

[Means for solving the problem]

To achieve the above object, the present invention provides a shift shaft rotatably supported at a fixed position in a transmission case, one end of which is selectively engaged with a fork head, and is axially moved with respect to the shift shaft. A shift select lever that is operated by a relative movement and is shifted by rotating integrally with the shift shaft, and two return springs that are inserted through the shift shaft and elastically support the shift select lever at a neutral position. In a speed change mechanism of a transmission in which one forward gear and one reverse gear are on the same shift operation line, the shift gear is inserted through a shift shaft to support one end of one return spring, and shifts along the outer periphery of the return spring. It has a cylindrical portion that extends cylindrically to the select lever side, and a shift select lever A spring seat integrally formed with a flange for defining a select operation limit position in a retreating direction, and is slidably inserted in the rotating direction and the axial direction around the outer periphery of a cylindrical portion of the spring seat to fix a transmission case and the like. The rotation angle is defined in a certain angle range by the part,
A restrict cam having a locking portion for preventing a shift operation of the shift select lever from the forward gear to the reverse gear;
It is arranged on the outer periphery of the cylindrical portion of the spring seat and on the outer periphery side of the return spring, and urges the restricting cam to rotate in the shift direction of the forward gear, and pushes the restricting cam toward the shift select lever side. And a torsion spring that urges axially to a position where it comes into contact with the torsion spring.

[Action]

When the shift select lever is operated to select the forward gear and the reverse gear, the shift select lever pushes the locking portion of the restrict cam against the torsion spring. When the shift select lever is shifted to the forward gear from this state, the engagement between the locking portion and the shift select lever is released, and the gear can be shifted to the forward gear. Also,
When attempting to shift directly from the forward gear to the reverse gear, the shift select lever hits the locking portion of the restrict cam and cannot be rotated to the reverse gear, so that misshifting can be reliably prevented.

〔Example〕

The figure shows an example of a shift operation mechanism of a manual transmission having five forward speeds and one reverse speed.

In the figure, a shift shaft 3 is slidably inserted into lateral support holes 2a and 2b formed in a transmission case 1, and a shift outer lever 4 is provided at an end of the shaft 3 protruding outside the case. Are fixed by welding. The shift outer lever 4 is connected to a change lever (not shown) via a cable or the like. The other end of the shift shaft 3 is formed with a semicircular groove 3a that is screwed into the transmission case 1 and engages with the guide bolt 5, so that the shift shaft 3 is allowed to rotate only at a certain angle. A spline 3b is provided at an intermediate portion of the shift shaft 3, and a shift select lever 6 is slidably fitted in the spline 3b only in the axial direction.

The shift select lever 6 has a disk-shaped engaging projection 6a protruding in the radial direction. The engaging projection 6a is a fork head 7 for 1-2 speed, a fork head 8 for 3-4 speed or a 5 speed. -R fork head 9 can be selectively engaged. In addition, a detent lock ball 10 and a spring 11 are provided inside a convex portion 6b having a rectangular cross section projecting in a direction perpendicular to the engaging protrusion 6a. The lock ball 10 engages with a detent groove 3c formed on the outer surface of the shift shaft 3, and holds the shift select lever 6 at a neutral position with a sense of moderation. An engagement groove 6c is formed on the surface on the side opposite to the protrusion 6b so as to engage the tip of the select inner lever 12 in the entire shift stroke range. The select inner lever 12 is fixed to one end of a select shaft 13, and the other end of the select shaft 13 projects outside the transmission case 1, and a select outer lever 14 is welded and fixed to the end thereof.
The select outer lever 14 is also connected to a change lever (not shown) via a cable or the like. The select shaft 13 is a guide bolt screwed into the transmission case 1.
By 15 only rotation is allowed. When the select inner lever 12 is selected (rotated), the shift select lever 6 moves in the axial direction along the spline 3b of the shift shaft 3, and the engaging protrusion 6a engages with any one of the fork heads 7 to 9. I do. When the shift shaft 3 is shifted (rotated) by the shift outer lever 4, the shift select lever 6 is also rotated integrally, and only the selected fork head can be operated in the axial direction.

An interlock plate 16 having a substantially U-shaped cross section is inserted through the shift shaft 3 so as to be relatively rotatable and axially movable. The interlock plate 16 is formed to have a substantially U-shaped cross section so as to embrace both left and right surfaces of the shift select lever 6, and the engagement pieces 16 a and 16 b bent inward are engagement protrusions of the shift select lever 6. 6a is engaged with another unengaged fork head. Interlock plate
A rear surface 16c, which is a surface parallel to the axial direction of the transmission case 16, faces the guide surface 1a provided on the inner surface of the transmission case 1 in a close state, and the rear surface 16c and the guide surface 1a define an interlock plate 16a. Is prevented from rotating, and is movable in the axial direction together with the shift select lever 6. Therefore, the interlock plate 16 stops the movement of the other fork heads to which the shift select lever 6 is not engaged,
Has a function to prevent double gear.

Return springs 18 and 19 are disposed in a compressed state between one side of the interlock plate 16 and the inner surface of the transmission case 1 and between the other side of the interlock plate 16 and the spring seat 17, respectively. I have. The shift select lever 6 is connected to these two return springs 18,1.
When the shift select lever 6 is selectively operated, the right and left return springs 18 and 19 are compressed, so that the select return force to the neutral position can be exerted.

A spring seat 17 supporting one return spring 19 is inserted through the shift shaft 3, and an inner flange 17b at one end is pinched between a step of the spline portion 3b and the transmission case 1 so that it cannot move in the axial direction. Has become. The spring seat 17 is a cylindrical portion that extends cylindrically in the direction of the shift select lever 6 along the outer periphery of the return spring 19.
17c, and an outer flange is provided on the outer periphery of the tip of the cylindrical portion 17c.
17a is integrally formed. When the shift select lever 6 is operated in the fifth speed-R direction, the side surface of the interlock plate 16 hits the outer end surface of the outer flange 17a, and the operation limit position of the shift select lever 6 is defined. A restrict cam on the outer peripheral surface of the spring seat 17
20 is slidably supported in the rotation direction and the axial direction. This restrict cam 20 is substantially annular as shown in FIG.
Two protrusions 20a and 20b projecting to the side are formed at substantially symmetrical positions, and a stopper piece 20c that contacts the guide surface 1a of the transmission case 1 is formed. The wide projection (locking portion) 20a of the projections can be brought into contact with the stopper surface 1b of the transmission case 1 facing the guide surface 1a, and this projection 20a will be described later (FIG. 5). (See FIG. 8) A reverse misshift prevention mechanism is configured. Above stopper piece
In the vicinity of 20c, one end 21a of a torsion spring 21 arranged on the outer periphery of the restrict cam 20 is locked,
The other end 21b of the torsion spring 21 is locked to the transmission case 1. Therefore, the restrict cam 20 is
As shown in FIG. 2, the stopper piece 20c comes into contact with the guide surface 1a of the transmission case 1 and is stopped. The restrict cam 20 is urged in the direction of the shift select lever 6 by the compression force of the torsion spring 21, and stops on the inner end surface of the outer flange 17 a of the spring seat 17. When the restrict cam 20 stops at the initial position in this manner, the protrusions 20a and 20b of the restrict cam 20 form a certain gap with respect to one side surface of the shift select lever 6 in the neutral position as shown in FIG. They are facing each other. This gap is for preventing the shift select lever 6 from being erroneously engaged with the projections 20a and 20b when shifting to the third speed and the fourth speed.

As described above, the spring seat 17 functions as a spring seat of the return spring 19, a function as a stopper surface of the shift select lever 6 at the time of selection, a function as a guide surface of the restrict cam 20, and a restrict cam. It also has a function as a stopper surface that defines the 20 initial positions. Since the return spring 19, the spring seat 17, the restrict cam 20, and the torsion spring 21 constituting the misshift prevention mechanism are sequentially arranged in the radial direction on the outer periphery of the shift shaft 3, the axial dimension can be greatly reduced. In addition, since all the shift operation mechanism components are provided on the shift shaft 3, the shift operation mechanism can be configured to be extremely compact.

Here, the restrict cam shown in FIGS.
The operation of No. 20, that is, the operation of the reverse misshift prevention mechanism will be described.

First, as shown in Figs. 5a and 5b, select inner lever
When the shift select lever 6 is operated in the fifth speed-R direction by using 12, the side surface of the shift select lever 6 hits the projections 20a and 20b of the restrict cam 20, and the restrict cam 20 is laterally integrated with the shift select lever 6. Is pushed to. As described above, the restrict cam 20 is pushed by the shift select lever 6 at two substantially symmetrical points, so that the inclination of the restrict cam 20 is prevented, and the restrict cam 20 moves smoothly. Accordingly, the return spring 19 on one side of the shift select lever 6 is compressed, and the torsion spring 21
Is also compressed. Then, the side surface of the interlock plate 16 comes into contact with the outer end surface of the outer flange 17a of the spring seat 17 and stops, and the engagement projection 6a of the shift select lever 6 engages with the fifth speed-R fork head 9.

In this state, when the shift select lever 6 is shifted in the fifth speed direction as shown in FIGS. 6A and 6B, the side surfaces of the shift select lever 6
Then, the guide bolt 5 rotates clockwise until the tip of the guide bolt 5 comes into contact with the edge of the meniscus groove 3a. By the clockwise rotation of the shift select lever 6, the engagement protrusion 6a shifts the fifth speed-R fork head 9 in the fifth speed direction. At this time, the restrict cam 20 is moved to the fifth position by the compression force of the torsion spring 21.
Pressed downward in the figure, the outer flange 17a of the spring seat 17
And returns to the initial position. Since the shift select lever 6 is separated from the protrusion 20a of the restrict cam 20 first and then the protrusion 20a, the shift feeling of the shift select lever 6 does not suddenly change, and the operability is improved.

Now, when the change lever is directly shifted in the R direction from the fifth gear state, the shift select lever 6 tries to rotate counterclockwise as shown in FIG. Along with this, the convex portion 6b of the shift select lever 6 hits the side edge of the wide projection 20a of the restrict cam 20, and the restrict cam 20 also rotates counterclockwise. However, since the projection 20a of the restrict cam 20 hits the stopper surface 1b of the transmission case 1 when the neutral position is exceeded, the projection 20a is sandwiched between the stopper surface 1b and the protrusion 6b of the shift select lever 6. ,
The rotation of the shift select lever 6 in the R direction is prevented. Therefore, the shift to the R position cannot be performed, and the reverse miss shift is reliably prevented.

When the change lever is operated from the neutral position to the R position, the shift select lever 6 is moved from the state shown in FIG. 5a.
Is rotated counterclockwise, so that the shift select lever 6 is
It rotates while sliding on 20b, and can be easily shifted to the R position as shown in FIG.

The present invention is not limited to the speed change operation mechanism as in the above embodiment, but can be applied to other types of speed change operation mechanisms. For example, the locking projection 20a of the restrict cam 20 is sandwiched between the shift select lever 6 and the stopper surface 1b of the transmission case 1 so as to prevent a misshift in the reverse step direction. Alternatively, another fixing member (not shown) may be used.

[Effect of the invention]

As is apparent from the above description, according to the present invention, since the spring seat is arranged on the outer peripheral side of the return spring and the restrict cam is arranged on the outer peripheral side of the spring seat, each component constituting the misshift prevention mechanism is provided. Are arranged radially with respect to the shift shaft. Therefore, the axial dimension of the speed change operation mechanism can be greatly reduced, and the problem of the deflection of the shift shaft can be solved, so that a highly reliable misshift prevention device with little backlash or the like can be realized.

[Brief description of the drawings]

FIG. 1 is a sectional view of an example of a speed change operation mechanism according to the present invention;
2 is a sectional view taken along the line II-II of FIG. 1, and FIG. 3 is a sectional view taken along the line II of FIG.
FIG. 4 is a plan view of the restrict cam,
5 to 8 are explanatory views showing the operation of the reverse misshift prevention mechanism. DESCRIPTION OF SYMBOLS 1 ... Transmission case, 1b ... Stopper surface, 3 ... Shift shaft, 6 ... Shift select lever, 7-9 ... Fork head, 16 ... Interlock plate, 17 ... Spring seat, 17a ... Outer flange, 18, 19: Return spring, 20: Restricted cam, 20a: Projection (locking portion), 21: Torsion spring.

Claims (1)

(57) [Scope of request for utility model registration] A shift shaft rotatably supported at a fixed position in a transmission case, and one end is selectively engaged with a fork head, and is selectively moved relative to the shift shaft in the axial direction. A shift select lever operated and shifted by rotating integrally with the shift shaft; and two return springs inserted through the shift shaft and elastically supporting the shift select lever at a neutral position, and including one forward gear. In the speed change operation mechanism of a transmission in which the reverse gear is on the same shift operation line, the shift operation mechanism is inserted into the shift shaft to support one end of the return spring, and is cylindrically formed along the outer periphery of the return spring toward the shift select lever. The select lever has a cylindrical portion that extends to the outer periphery of the tip of the cylindrical portion. A spring seat integrally formed with a flange for defining an operation limit position, and slidably inserted in the rotation direction and the axial direction around the outer periphery of a cylindrical portion of the spring seat, and the rotation angle is fixed by a fixed portion such as a transmission case. A restrict cam defined by a fixed angle range and having a locking portion for preventing a shift operation of the shift select lever from the forward gear to the reverse gear, and a return cam which is an outer periphery of a cylindrical portion of the spring seat and A torsion spring which is arranged on the outer peripheral side of the spring and biases the restricting cam in the shift direction of the forward gear and axially biases the restricting cam toward the shift select lever to a position where the restrict cam comes into contact with the flange; A shift preventing device for a shift operation mechanism, comprising: