JPS6235931B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a speed change operation mechanism for switching a speed change mechanism provided in a transmission case of a tractor.

In order to make it easier to get on and off the tractor and to improve comfort by creating a wide space up to the ceiling inside the cabin, a flat floor plate is provided above the transmission case, and the change lever is The applicant has proposed a speed change operation mechanism that does not protrude upward from the transmission case, but protrudes outward from one of the left and right side walls.
This is proposed in issues such as No. 091095.

In order to keep the upper surface of the transmission case as low as possible, the shifter stay of the shift part is placed near the inside of the side wall of the transmission case. In this case, the numerous engagement arms attached to the shifter stay are arranged in a concentrated manner near the upper part of the side wall, and for this reason, the upper part of the side wall of the transmission case must be formed to bulge outward. , there is a disadvantage that the left and right width of the transmission case becomes wider.

Therefore, in this invention, an operation shaft is provided which is disposed laterally and passes through one of the left and right side walls of the mission case whose ceiling is formed into a generally flat plate shape, and the two shifter stays on the first side are connected to each other. A shifter stay on the other side is arranged in the upper part of one of the side walls in the vertical direction and parallel to each other, and a shifter stay on the other side is connected to the shifter stay on the first side on the upper part of the inside of the other side wall. A shifter is fixed to each of these shifter stays in a removable manner to a slide coupling of a transmission mechanism, and an engagement arm is fixed to each of the shifter stays, and the engagement of each engagement arm is The joining head is removably connected to an engaging body fixed to an operating shaft that is linked to the change lever, and the shifter can be connected to and removed from the slide coupling ring in conjunction with the change lever, and the shift part is operated by the change lever. By arranging the shifter stay, etc., using the space near the left and right inner corners of the transmission case's ceiling and side walls, the transmission case can be made smaller while keeping its width narrow. It has been devised so that it can be done.

And if one example is explained based on a figure,
As shown in a cross-sectional rear view in FIG. 3, a small window 2 is provided in the upper part of the side wall 1b of the transmission case 1 in the left and right lateral directions. Operating bearing 3 that can be closed
is attached to the one side wall 1b with bolts 4, and the operating shaft 5 is inserted into the operating bearing 3 and the other wall 1a so that it can freely rotate around the axis and move in the axial direction. Two shifter stays 6 and 7 on the first side are placed parallel to each other and vertically in the inner corner R formed by the ceiling portion 1c formed in a roughly flat plate shape of the first side wall 1c and the upper part of the one side wall 1b. As shown in FIG. The shifter stay 8 is positioned parallel to the shifter stays 6 and 7 and loosely inserted into the partition wall 1d and the rear wall 9a of the spacer mechanism case 9, and the upper shifter stay 8 is roughly L-shaped in front view as shown in FIG. The engagement arm 10 is fixed to the upper shifter stay 6 on the first side, and the lower engagement arm 11, which has a perspective shape when viewed from the front, is fixed to the lower shifter stay 7 on the first side. The groove-shaped engaging portions 10a and 11a at the tips of 10 and 11 are brought close to each other to form an inner corner R.
Further, an engagement arm 12 having an oblique shape when viewed from the front is fixed to the shifter stay 8 on the other side, and a groove-shaped engagement portion 12a is located near the inner corner L, Engaging bodies 13 and 14 are fixed to the operating shaft 5 with bolts 15 and 16 facing downward, respectively.

Further, an operating shaft 5 protrudes outward from the operating bearing 3.
The lower part of the mounting rod 17 is attached to the end of the mounting rod 17 with a pin 18, and a small window 20 is provided in the floor plate 19 installed close to and above the ceiling 1c of the mission case 1. A connecting body 21 provided to sandwich it from the left and right protrudes upward from the small window 20, and is fixed to the mounting rod 17 with bolts 22. A change lever 23 is fixed to the upper end of this connecting body 21, and the change lever The change lever 23 is swingably supported by a truncated conical spring 25 provided between a washer 24 attached to the lower part of the handlebar 23 and a floor plate 19 near the small window 20. A support member 26 is attached to the cylindrical portion 3b formed in the cylindrical portion 3b.
The lower part of the connecting body 21 is externally fitted to the support part 26a of the support member 26, and the support part 2
Connect the fulcrum bolt 27 inserted through the connecting body 21
The elongated hole 21a (fulcrum bolt 27
There is some play in the vertical direction, but there is no play in the left and right directions, so it is long in the vertical direction so that it fits almost tightly).
The change lever 23 can reciprocate within a certain angle range around the operating shaft 5, and the fulcrum bolt 27
Since the transmission case 1 can reciprocate within a certain angle range in the left and right direction around the axis, the operation shaft 5 can reciprocate by a certain distance in the axial direction.

The transmission mechanism illustrated in FIG. 2 has a first transmission shaft 29 pivotally supported at the rear of an input shaft 28 driven by the left and right engines in the figure via a main clutch. The gear 28a of the input shaft 28 is connected to the gear 31 of the counter gear 30 provided below.
Also, the change gears 32, 33, 34 loosely fitted to the first speed change shaft 29 are always meshed with the gears 35, 36, 37 of the counter gear 30, and the shift gears 32, 33, 34, which are loosely fitted to the first speed change shaft 29, are always engaged with the gears 35, 36, 37 of the counter gear 30. If the slide coupling ring 39 is moved to the left or right via the gear 28a, the input shaft 28 and the first
4 speed with the gear shift shaft 29 as one unit, or the gear 31
are fixed to the first speed change shaft 29, and the first
The gear shift shaft 29 is driven, and if a shift member such as a slide coupling 41 is moved to the left via the shifter 40 fixed to the lower shifter stay 7, the gear 33 is moved to the left, and the gear 33 is moved to the right. When the gears 34 are moved, they are fixed to the respective first speed change shafts 29, and the first speed change shafts 29 are driven at the second speed or the first speed, respectively, and as shown in the figure, the gears 34 are fixed to the first speed change shafts 29. A known transmission mechanism such as a transmission mechanism is used.

Also, the back change gear 43 loosely fitted on the second speed change shaft 42 is connected to the counter gear 4 via a back counter gear 44 which is pivotally supported on the transmission case 1.
5, and move a shift member such as a slide coupling 47 to the right in FIG. 2 via the shifter 46 fixed to the shifter stay 8 on the other side and engage the back change gear 43 , second
A reversing mechanism is provided in which the speed change shaft 42 rotates in the opposite direction.

When the slide coupling rings 39, 41 are in the neutral position, the engaging portions 10a, 11a are arranged side by side with each other, and when the operating shaft 5 is moved in the axial direction in this neutral position, the engaging portions 10a, 11a are arranged side by side. 13
The engaging head 13a can be engaged with and disengaged from the engaging part 10a or 11a, and when the engaging head 13a is engaged with the engaging part 10a or 11a, the operating shaft 5 can be rocked around its axis. When the rotation operation is performed, the shifter 38 or 40 moves the slide coupling 39 or 41 together with the shifter stay 6 or 7, and the engagement head 14a of the engagement body 14 is engaged, and the operation is performed. When the shaft 5 is rotated about its axis, a shifter 46 is provided so that a slide coupling ring 47 is shifted.

Further, in the illustrated example, an opening 48 is provided in the ceiling 1c of the mission case 1, and the shifter stay 6,
7, 8, slide coupling rings 39, 41, etc., and engagement bodies 13, 14 and engagement portion 10.
The engagement and disengagement operations of a, 11a, and 12a can be visually observed through this opening 48. Also, code 4
9 is a lid.

In addition, in the embodiment, the change guides 50 and 51 are
Since the operation bearing 3 can be installed outside the transmission case 1 and then assembled, the installation work is easy, and these change guides 50 and 51 are
The engaging body 1 is provided at a position extremely close to the engagement/disengagement operation.
Since the movements of steps 3 and 14 are guided, the gear shifting operation is smooth and free of twisting.

The speed change operation mechanism according to the present invention has two functions as described above.
The shifter stays 6 and 7 on the 1st side of the side walls 1a and 1b
The shifter stay 8 on the other side is disposed on the inside of one of the side walls 1a, 1b in the vertical direction and parallel to each other, and the shifter stay 8 on the other side is arranged on the inside top of the other side wall 1a, 1b. Since the shifter stays 6, 7 are provided parallel to each other, the shifter stays 6, 7, or 8, etc., and the mission case 1
The width of the cabin 52 can be kept narrow, making it possible to downsize the cabin 52, increasing the space inside the cabin 52, and further improving the comfort.

[Brief explanation of the drawing]

The figures show one embodiment of the present invention, in which Fig. 1 is a plan view of a tractor, Fig. 2 is a vertical cross-sectional side view of the main part of the transmission case, and Fig. 3 is a longitudinal cross-sectional rear view of the main part of the transmission case. FIG. 4 is a sectional view taken along the line A--A in FIG. 3. Code explanation, 1...Mission case, 1a, 1
b...Side wall, 1c...Ceiling, 1d, 1e...Partition wall, 2, 20...Small window, 3...Operation bearing, 3a
...Mounting part, 3b...Cylindrical part, 4, 15, 16,
22... Bolt, 5... Operation axis, 6, 7, 8...
Shifter stay, 9...Space mechanism case, 9a...Rear wall, 10, 11, 12...Engagement arm, 10a, 11a, 12a...Engagement portion, 1
3, 14... Engaging body, 13a, 14a... Engaging head, 17... Mounting rod, 18... Pin, 19... Floor plate, 21... Connecting body, 21a... Elongated hole, 23... Change lever, 24...Washer, 2
5... Spring, 26... Supporting member, 26a... Supporting part, 27... Fulcrum bolt, 28... Input shaft, 28
a, 31, 35, 36, 37...gear, 29...
1st speed change shaft, 30, 45...Counter gear, 3
2, 33, 34... Chain gear, 38, 40,
46...Shifter, 39, 41, 47...Slide coupling, 42...Second shift shaft, 43...Back change gear, 44...Back counter gear, 48...Opening, 49...Lid, 50 ,51...
...Change Guide.

Claims (1)

[Claims] 1. An operation shaft is installed in the horizontal direction passing through one of the left and right side walls of the transmission case whose ceiling is formed into a generally flat plate shape, and the two shifter stays on the first side are connected to either of the side walls. A shifter stay on the other side is provided in the upper part of the inner side of one of the side walls in the vertical direction and parallel to each other, and a shifter stay on the other side is provided on the upper part of the inner side of the other side wall in parallel with the shifter stay on the first side. , a shifter is removably fixed to each of these shifter stays, and
An engagement arm is fixed to each shifter stay, and an engagement head of each engagement arm is detachably provided to an engagement body fixed to an operating shaft linked to a change lever, and the shifter is connected to the change lever. 1. A gear shift operation mechanism for a tractor, characterized in that the gear shift operation mechanism for a tractor is configured to be able to engage and disengage from a slide coupling ring in conjunction with each other, and to operate a shift portion using the change lever.