JP4053259B2 - Shifter fork of transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shifter fork that reverses the axial movement of a shifter rod and transmits it to a shifter sleeve attached to the countershaft side.
[0002]
[Prior art]
When transmitting the axial movement of the shifter rod to the shifter sleeve mounted on the counter shaft side, conventionally, as shown in FIGS. 3 and 4, for example, an auxiliary rod B parallel to the shifter rod A is provided, and the shifter rod A and the auxiliary rod B are provided. Are coupled via an inversion lever C, and a shifter fork F engaged with a shifter sleeve E mounted on the countershaft D side is mounted on the auxiliary rod B, thereby reversing the axial movement of the shifter rod A and shifting the sleeve I was trying to communicate to E. G is a main shaft, H is a head, and I is a pin.
[0003]
However, in the case of such a conventional example, since it is necessary to provide predetermined play at the connecting portions of the shifter rod, the auxiliary rod, and the inversion lever to smooth the movement, the play as the entire speed change operation device is reduced. There is a tendency to become too large. Therefore, when an inversion lever is used as a relay part in this way, the number of parts is increased, and it is necessary to excessively increase the processing accuracy of each linking part to eliminate the play of the entire speed change device. there were.
[0004]
Also, such in order to solve the problem, although it is also effective to use a large shift fork straddling the countershaft include main shaft as seen in Japanese Unexamined Patent Publication No. 10-205618, in this case Since it is necessary to provide a space for mounting the shift fork on both sides of the main shaft, the width dimension of the transmission case becomes large.
[0005]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and is capable of reducing the number of parts and avoiding backlash as a whole speed change operation device without requiring excessive machining accuracy. The challenge is to provide a shifter fork.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, a shifter fork of a transmission according to the present invention includes a main lever portion that bypasses one side of the main shaft from the shifter rod and reaches the vicinity of the counter shaft, and the opposite of the main lever portion across the counter shaft. A sub-lever part located on the side, and a connecting part that integrates both lever parts through between the main shaft and the counter shaft, and extends above the connecting part between the intermediate part of the main lever part and the connecting part The shifter fork that operates the shifter sleeve attached to the countershaft is directly linked to the shifter rod by pivotally attaching the extended end of the sub- lever part to the transmission case via a fulcrum located on the same axis. It is characterized by.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the drawings. In FIG. 1 exemplifying the use situation of a shifter fork according to the present invention, a plurality of shifter rods 2 are arranged in parallel on the upper part of a transmission 1, and a main shaft 3 is pivoted on a central portion of the transmission 1. A counter shaft 4 is pivoted at the lower part of the machine 1.
[0008]
Then, by selectively moving the shifter rod 2 in the axial direction by operating means (not shown), the meshing state of gears (not shown) attached to the main shaft 3 and the counter shaft 4 is changed as in the case of a conventionally known gear transmission. It is possible to change and control the transmission ratio between an input shaft and an output shaft (not shown).
[0009]
Here, in the present embodiment, the shifter rod 2 and the shifter sleeve 5 attached to the counter shaft 4 are connected using a shifter fork 6 having a front h-shape . That is, the shifter fork 6 according to the present embodiment includes a main lever portion 6a that hangs down from the shifter rod 2 and bypasses one side of the main shaft 3 as shown in FIG. 4 is provided with a sub-lever portion 6b located on the opposite side of the main lever portion 6a with a pin 4 therebetween, and a connecting portion 6c that passes between the main shaft 3 and the counter shaft 4 and integrates both the lever portions 6a and 6b.
[0010]
Further, the transmission case 1 is connected to the intermediate lever portion of the main lever portion 6a and the extended end of the sub lever portion 6b extended from the connecting portion with the connecting portion 6c via fulcrums 7a and 7b located on the same axis. The shift fork 6 is swung around the fulcrums 7a and 7b as the shifter rod 2 moves in the axial direction, so that the shifter sleeve is engaged with the lower ends of the main lever portion 6a and the sub lever portion 6b. 5 is moved in the direction opposite to the shifter rod 2 to obtain a predetermined gear ratio. Reference numerals 6d and 6e denote pads attached to the lower ends of the main lever portion 6a and the sub lever portion 6b. The pads 6d and 6e are slidably fitted into the engaging grooves of the shifter sleeve 5.
[0011]
In the shifter fork configured as described above, the movement of the shifter rod 2 is transmitted only to the main lever portion 6a. However, after the main lever portion 6a and the sub lever portion 6b are coupled and integrated through the connecting portion 6c, both lever portions 6a and 6b are connected to the transmission case 1 via fulcrums 7a and 7b located on the same axis. Since the main lever portion 6a and the sub lever portion 6b are not twisted, the sub lever portion 6b swings integrally with the main lever portion 6a to smoothly move the shifter sleeve 5. Move to.
[0012]
Further, since one end of the shifter fork 6 is directly engaged with the shifter rod 2, there is no need to provide a relay part such as an inversion lever, and accordingly, the number of parts and the number of connecting parts are reduced. For this reason, there is no need to excessively increase the processing accuracy of each connecting portion to eliminate the feeling of rattling.
[0013]
Further, only the main lever portion 6a of both lever portions 6a and 6b is protruded greatly from the fulcrum 7a and engaged with the shifter rod 2, while the extended end of the sub lever portion 6b is pivotally attached to the transmission case. Therefore, it is only necessary to secure a space for disposing the main lever portion 6a (shift fork 6) on only one side of the main shaft 3, and an increase in the width dimension of the transmission case can be suppressed.
[0014]
In the embodiment, the upper surface of the connecting portion 6c is recessed in a U shape, and the sub lever portion 6b is extended upward (shifter rod side) from the connecting portion with the connecting portion 6c, and the extended end thereof is the transmission case 1. The fulcrum 7a and 7b are set at the intermediate part of the main lever part 6a while securing the coupling rigidity of the main lever part 6a and the sub-lever part 6b by being pivotally attached to the fulcrum 7b. Is not limited to that of the embodiment.
[0015]
【The invention's effect】
As is clear from the above description, the present invention is such that the shifter fork for operating the shifter sleeve is directly connected to the shifter rod, so there is no need to use a relay part such as an inversion lever, and the number of parts is reduced. In addition to being able to reduce the amount of play, it is possible to avoid the play caused by the accumulated play of the connected portions. Moreover, since it is sufficient to secure the shifter fork mounting space only on one side of the main shaft, an increase in the width dimension of the transmission case can be suppressed.
[Brief description of the drawings]
FIG. 1 is a schematic side view of a transmission illustrating the use of a shifter fork according to the present invention.
FIG. 2 is a front view of the shifter fork shown in FIG.
FIG. 3 is a schematic side view of a transmission showing a conventional example of a shifter fork.
4 is a front view of FIG. 3;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Transmission 2 Shifter rod 3 Main shaft 4 Counter shaft 5 Shifter sleeve 6 Shifter fork 6a Main lever part 6b Sub-lever part 6c Connection part 6d, 6e Pad 7a, 7b A fulcrum

Claims (1)

A main lever portion (6a) that bypasses one side of the main shaft (3) from the shifter rod (2) and reaches the vicinity of the counter shaft (4), and the opposite of the main lever portion (6a) across the counter shaft (4) A sub-lever portion (6b) located on the side, and a connecting portion (6c) that integrates the lever portions (6a) and (6b) through the space between the main shaft (3) and the counter shaft (4), The fulcrums (7a) and (7b) where the extended ends of the sub- lever part (6b) extended upward from the connecting part between the intermediate part of the main lever part (6a) and the connecting part (6c) are located on the same axis. The shifter fork (6) for operating the shifter sleeve (5) attached to the countershaft (4) is linked directly to the shifter rod by being pivotally attached to the transmission case via Shifter fork of the speed machine.

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