JPS621481Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a reverse transmission device used in a tricycle, a small four-wheel vehicle, or the like.

For example, unlike conventional tricycles, tricycles with balloon tires have a simple configuration similar to motorcycles, and their transmissions use a forward-only gear shift cam system similar to motorcycles. . However, in the case of a tricycle, it is desirable to be able to move backwards in terms of mobility.

Therefore, it was considered to add a reverse transmission to the gear shift cam type transmission for general driving.
A method has been devised in which a conventional gear shift cam for general driving, such as a gear shift drum, is provided with a backing lead groove, and the backing gear is slid in the axial direction through the lead groove via a shift fork to mesh with the idle gear.

However, this method requires a sliding space for sliding the back gear, which is disadvantageous in that the width of the transmission becomes large. In addition, in the case of this method, in order to prevent the back gear from sliding accidentally, a stopper is engaged with the drum so that the drum cannot be rotated and the back gear cannot be slid unless the stopper is released. There is a need to. Therefore, in order to shift the transmission into reverse, two operations must be performed: releasing the stopper and rotating the drum, which is cumbersome.

The present invention solves the above-mentioned drawbacks of the prior art and restricts the movement of the push rod and the rotation of the gear shift cam for general driving by a recess provided in the cam and a stopper arm, thereby reducing the backlash during general driving. It is an object of the present invention to provide a reverse transmission that can prevent a shift to normal driving when reversing.

The feature of this invention is that the shift fork is operated by rotating the gear shift drum.
In a transmission device in which a sliding gear for shifting supported by a rotating shaft is manipulated in the axial direction to mesh with a predetermined shifting gear to change gears, the backing gear is rotatably supported on the axis of the rotating shaft. A push rod having a hollow portion formed on the outer circumferential surface thereof is inserted into the hollow portion, and a radial hole extending from the inside to the outside corresponding to the inner circumferential surface of the backing gear is formed in the rotating shaft. and an engaging member is disposed in the space formed by the recess of the push rod and the hole of the rotating shaft, a stopper cam for operating the push rod in the axial direction is supported on a lever shaft, and the lever is attached to the lever shaft. A stopper arm that rotates as the shaft is rotated is mounted, and a recess is formed on the outer circumferential surface of the gear shift drum that corresponds to a protruding end portion of the stopper arm when the gear shift drum is in a neutral position. , the engaging member is brought into pressure contact with the inner circumferential surface of the reverse gear via the convex portion of the push rod at a position where the protruding portion of the stopper arm engages with the concave portion of the gear shift drum, thereby operating the reverse gear. That's what I did.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.

FIG. 1 is a conceptual sectional view showing an embodiment of a reverse transmission according to the present invention, and this embodiment is attached to the above-mentioned gear shift drum type transmission for general driving.

In the figure, 1 is an intermediate shaft to which rotation is transmitted from the crankshaft of the engine via a clutch (not shown), and 2 is an output shaft installed in parallel with the intermediate shaft. A multi-speed gear (only a part of which is shown) 3 for general driving is provided. Therefore, the rotation of the intermediate shaft 1 is transmitted to the output shaft 2 after being changed by the speed change gear 3, and further transmitted to the wheels via the sprocket 4 and a chain (not shown). Further, a predetermined gear in the transmission gear 3 is slid as appropriate via a known gear shift drum 5 and a shift fork (not shown).

The reverse transmission includes a reverse drive gear 10 provided on the intermediate shaft 1, a reverse idle gear 11 (not shown in FIG. 1, see FIG. 2) that is always meshed with the gear 10, and A back driven gear 12 that is always meshed with the gear 11, an output shaft 2 that rotatably supports the gear 12, and a hollow portion provided on the axis within the output shaft 2 so as to be movable in the axial direction. and a push rod 13 rotatably arranged with respect to the output shaft 2, and a radial direction provided on the output shaft 2 corresponding to the inner circumferential surface of the backing gear so as to penetrate inside and outside of the output shaft 2. two cylindrical holes 14
and a ball 15 serving as an engaging member disposed in a space formed by the hole 14 and a recess (described later) formed in the push rod 13,
A concave portion (concave groove in the axial direction of the gear 12) 16 is formed on the output shaft joint surface of the driven gear 12, and an uneven portion 17a (a groove with a trapezoidal cross section formed at right angles to the axial direction on the outer periphery of the push rod) 17a,
17b, and when the engaging member 15 is located on the recess 17a of the push rod, the hole 1
4 and positioned on the convex portion 17b, it protrudes from the output shaft 2 and engages with the concave portion 16 of the driven gear, so that the driven gear 12 and the output shaft 2 are connected to rotate integrally. (See FIG. 3, which shows a cross section taken along the - line in FIG. 1). Note that the numbers of the holes 14, engagement members 15, and recesses 16 can be set as appropriate.

In this embodiment, the rod 13 is further urged in one direction in the axial direction by a spring 18, which is an elastic member disposed at one end of the push rod 13.
A stopper cam 19 is disposed in contact with the tip of the rod 13 in the biasing direction, the cam 19 is fixed to a lever shaft 21 via an arm 20, and a backshift lever 22 is fixed to the shaft 21. At the same time, a gear shift drum engaging stopper arm 23 is fixedly provided. As shown in FIG. 4 when viewed from the direction of arrow A in FIG. The stopper arm 23 is formed into an L-shape, as shown in FIG. 5 when viewed from the direction of arrow B in FIG. 1, and has a protrusion 23a at its tip. Further, the gear shift drum 5 is formed with a cylindrical recess 5a at a position corresponding to the protrusion 23a when the drum is in the neutral position. The above-mentioned cam 19 and stopper arm 23 are connected when the cam 19 is in the upper position (the position where the tip of the push rod 13 is in contact with the rear plate 19b of the cam, as shown by the solid line in FIGS. 1 and 4). , the protrusion 23a of the stopper arm is positioned on the surface of the drum 5 with a slight gap, and the cam 19 is placed in the lower position (as shown by the two-dot chain line in FIG. When the lever shaft 21 is rotated so that the lever shaft 21 is in contact with the drum 5, the protrusion 23a moves toward the drum 5. 24 in the direction away from the drum 5 (the direction in which the cam 19 rotates from the lower position to the upper position), and a stopper (not shown) is provided as appropriate to position the cam 19 at the upper position.

Next, the operation of the present invention will be explained.

The state shown in FIG. 1 is a state in which the cam 19 is in neutral and not shifted backward, that is, the cam 19 is in the upper position. In addition, the operation pattern of the gear shift drum 5 is TOP, 3rd gear, 2nd gear, 1st gear,
It is marked N. To shift backwards from this state, depress the lever 22 to move the cam 19 to the lower position. In this way, the push rod 13 is pushed in the direction of arrow C by the cam 19, and the engagement member 1
5 protrudes outward from the output shaft 2 by the convex portion 17b of the push rod and engages with the concave portion 16 of the driven gear, so that the output shaft 2 and the driven gear 12 are connected to rotate integrally (see Fig. 3). . Note that when the cam 19 is rotated to the downward position to shift backward, the stopper arm 23 is rotated toward the drum 5, and the drum 5 has a position corresponding to the protrusion 23a of the stopper arm when in neutral. Since the recess 5a is provided at the position, the cam 19 can be placed in the lower position by the projection 23a entering the recess 5a. However, in cases other than neutral, the tip of the protrusion 23a contacts the surface of the drum 5, and the cam 19 cannot be rotated to the lower position. In addition, when the protrusion 23a is inserted into the recess 5a of the drum, the protrusion 23a
This prevents the drum from rotating. That is, the stopper arm 23 and the concave portion 5a of the drum allow the vehicle to be shifted backwards only when in neutral, and are regulated so that it is not possible to shift to normal driving when it is shifted backwards. It has been done.

FIG. 6 shows another embodiment of the stopper cam 19, in which a stopper 25 engages a ball with two recesses provided in the cam arm 20 in order to position the cam 19 in two positions, an upper position and a lower position. It consists of In the embodiment shown in FIGS. 1 to 5, the spring 24 biases the cam 19 to the upper position, so the lever 22 must be kept depressed while moving backward. . However, in the embodiment shown in FIG. 6, the cam 19 is positioned at each of the two positions, so that even if the lever 22 is released, the backward movement state is maintained, which is convenient.

In the present invention, as described above, the back gear and the rotating shaft (in the above embodiment, the back driven gear and the output shaft) are connected to each other via the engaging member by the movement of the push rod. Therefore, it is possible to shift backwards without sliding the reverse gear on the rotating shaft, and there is no need to secure a sliding space for the reverse gear within the transmission.
It is possible to reduce the width of the transmission and is advantageous when increasing the number of gears.

In addition, by regulating the movement of the push rod and the rotation of the gear shift cam for general driving by the recess provided in the cam and the stopper arm, it is possible to shift to reverse during normal driving and to shift to normal driving when reversing. shift can be prevented.

Note that the reverse transmission according to the present invention can be modified in various ways without departing from the gist thereof, and is not limited to what is shown in the embodiments. Further, the present invention can be applied to things other than automatic tricycles, and can be attached to things other than the gear shift cam type general driving transmission shown in the embodiment.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional conceptual diagram showing an embodiment of the reverse transmission according to the present invention, FIG. 2 is a cross-sectional conceptual diagram showing the reverse drive gear, idle gear, and driven gear in FIG. 1, and FIG. Figure 4 is a conceptual diagram of a cross-sectional view taken along the - line in the figure, Figure 4 is a conceptual diagram seen from the direction of arrow A in Figure 1, Figure 5 is a conceptual diagram seen from the direction of arrow B in Figure 1, and Figure 6 is a conceptual diagram of the back shift of the present invention. It is a cross-sectional conceptual diagram which shows another Example of the lever part for use. 1... Intermediate shaft, 2... Output shaft (rotating shaft), 5...
... Gear shift cam, 5a... Recess, 10... Back drive gear, 11... Back idle gear, 12... Back driven gear (back gear), 13... Push rod, 14... Hole, 1
5... Engaging member, 16... Recessed portion of back gear, 1
7a, 17b... uneven portion of push rod, 18
...Elastic member, 19... Stopper cam, 21...
... Lever shaft, 22 ... Back shift lever, 23 ... Stopper arm.

Claims (1)

[Scope of utility model registration request] In a transmission device in which a shift fork is actuated by rotation of a gear shift drum, and a sliding gear for shifting supported on a rotating shaft is operated in the axial direction to mesh with a predetermined gear for shifting, thereby changing gears. A hollow part is formed on the axis of a rotating shaft that rotatably supports a back gear, and a push rod having an uneven part on its outer circumferential surface is inserted into the hollow part and corresponds to the inner circumferential surface of the back gear. forming a radial hole in the rotating shaft that penetrates the inner and outer sides thereof, and disposing an engaging member in the space formed by the recess of the push rod and the hole of the rotating shaft, and operating the push rod in the axial direction. A stopper cam is supported on a lever shaft, and a stopper arm that rotates as the lever shaft is rotated is attached to the lever shaft, and the tip of the stopper arm protrudes when the gear shift drum is in the neutral position. A concave portion corresponding to the push rod is formed on the outer circumferential surface of the gear shift drum, and the engaging member is moved to the back via the convex portion of the push rod at a position where the protruding portion of the stopper arm engages with the concave portion of the gear shift drum. A reverse transmission device characterized in that a reverse gear is operated by being pressed against the inner peripheral surface of the gear.