JP3407062B2

JP3407062B2 - Agricultural work vehicle

Info

Publication number: JP3407062B2
Application number: JP18086793A
Authority: JP
Inventors: 知晋野; 原裕昭貝
Original assignee: Yanma Agricultural Equipment Co Ltd
Current assignee: Yanma Agricultural Equipment Co Ltd
Priority date: 1993-06-25
Filing date: 1993-06-25
Publication date: 2003-05-19
Anticipated expiration: 2018-05-19
Also published as: JPH078003A

Description

【発明の詳細な説明】【０００１】【産業上の利用分野】本発明は例えばロータリ作業機を
装備させて耕耘作業などを行う農用作業車に関する。【０００２】【従来の技術】従来、実開平２−１０７９０２号公報に
示す如く、ミッションケースの外筒軸上にボールクラッ
チを介して常時噛合い変速ギヤを係脱自在に軸支させる
と共に、外筒軸の軸芯位置に内軸を摺動自在に挿通さ
せ、ボールクラッチを係合動作させる突起を内軸に設
け、該内軸一端側をミッションケース外部に突出させて
操作部材を取付ける技術がある。【０００３】【発明が解決しようとする課題】前記従来技術は、ケー
ス外側の内軸にノブを設けて押引する構造であるから、
ノブを押引操作するスペースを内軸の外側端部に確保す
る必要があり、ケースの形状または大きさが制限され易
く、例えば入力プーリ及び主変速及び副変速の各機構を
設けるミッションケースのコンパクト化または簡略化を
容易に行い得ない等の問題がある。そこで、特開昭５２
−６６０１号公報、または実開昭５０−８４６７５号公
報に示す如く、シフタフォークをミッションケースに揺
動自在に軸支させ、内軸に設けるシフタボスにシフタフ
ォークのピンを係合させ、レバーのシフタフォーク操作
によって切換える構造もあるが、シフタフォークを内装
または外装させるスペースをケースの内または外に確保
する必要があり、また切換え構造が複雑で高コストにな
る等の不具合がある。【０００４】【課題を解決するための手段】然るに、本発明は、ミッ
ションケースの外筒軸上にボールクラッチを介して常時
噛合い変速ギヤを係脱自在に軸支させると共に、外筒軸
の軸芯位置に内軸を摺動自在に挿通させ、ボールクラッ
チを係合動作させる突起を内軸に設け、該内軸一端側を
ミッションケース外部に突出させて操作部材を取付ける
農用作業車において、ボールクラッチを係合動作させる
突起を内軸に回転自在に取付けると共に、ミッションケ
ース外側の内軸にカムを設け、該カムを変速レバーにワ
イヤ連結させ、前記内軸の軸芯回りに前記カムを回転さ
せて前記突起を変速動作させるもので、前記カムの設置
スペースと、内軸の変速動作スペースをミッションケー
スの外側に確保するだけでコンパクトに構成し得、従来
のノブ構造のようにミッションケースの形状または大き
さが制限される不具合をなくし得、また従来のシフタフ
ォーク構造のように複雑で高コストになる不具合をなく
し得、例えば入力プーリ及び主変速及び副変速の各機構
を設けるミッションケースに低コストでコンパクトに設
置し得、また従来のシフトフォーク構造に比べて切換え
遊びを少なくして操作効率を向上させ得るものである。【０００５】【実施例】以下、本発明の実施例を図面に基づいて詳述
する。図１は副変速機構部の説明図、図２は管理機の側
面図、図３は同平面図、図４はミッションケース上部説
明図、図５は同下部説明図、図６は主変速機構部の説明
図、図７はミッションケース上部側面図であり、図中
（１）はエンジン、（２）は前記エンジン（１）を載せ
るエンジン台、（３）は前記エンジン台（２）を前側に
固定させるミッションケース、（４）は前記ミッション
ケース（３）両側に車軸（５）を介して取付ける左右一
対の走行輪、（６）は前記ミッションケース（３）にヒ
ッチ（７）を介して牽引連結させるロータリ作業機、
（８）は前記ミッションケース（３）上部にハンドルベ
ース（９）を介して連設させる操向ハンドル、（１０）
は前記ミッションケース（３）に前後振換え自在に支持
させる主変速レバー、（１１）は前記操向ハンドル
（８）に設ける副変速レバー、（１２）は同左右一対の
サイドクラッチレバー、（１３）は走行クラッチレバー
であり、エンジン（１）の出力プーリ（１４）とミッシ
ョンケース（３）の入力プーリ（１５）の間に走行クラ
ッチテンションローラ（１６）を介して駆動ベルト（１
７）を張設させ、エンジン（１）出力をミッションケー
ス（３）に伝達させると共に、ロータリ作業機（６）の
ロータリ爪（１８）を回転させて耕耘作業を行わせるよ
うに構成している。【０００６】さらに、図４、図６、図７に示す如く、入
力プーリ（１５）及び主変速ギヤ（１９）及びＰＴＯ出
力プーリ（２０）を設ける入力軸（２１）と、シフトフ
ォーク（２２）を介して主変速ギヤ（１９）を摺動させ
るフォーク軸（２３）と、後進ギヤ（２４）を設けるカ
ウンタ軸（２５）と、前進１速及び２速ギヤ（２６）
（２７）を設ける主変速軸（２８）をミッションケース
（３）に軸支させ、主変速軸（２８）に遊転軸支させる
１速ギヤ（２６）をカウンタ軸（２５）にカウンタギヤ
（２９）（３０）を介して連結させ、カウンタ軸（２
５）を主変速軸（２８）にカウンタギヤ（３１）（３
２）を介して連結させ、前進２段後進１段の主変速機構
（３３）を形成するもので、フォーク軸（２３）にシフ
トアーム（３４）を介して主変速レバー（１０）を連結
させ、後進ギヤ（２４）または１速ギヤ（２６）または
２速ギヤ（２７）に変速ギヤ（１９）を択一噛合させる
主変速レバー（１０）操作を行うように構成している。【０００７】さらに、図１、図４、図６に示す如く、ボ
ールクラッチ（３５）（３６）（３７）を介して係脱自
在に常時噛合い変速ギヤである低中高速用ギヤ（３８）
（３９）（４０）を設ける外筒軸である副変速軸（４
１）をミッションケース（３）に軸支させ、前記各ギヤ
（３８）〜（４０）を主変速軸（２８）の低中高速出力
ギヤ（４２）（４３）（４４）に常時噛合させると共
に、副変速軸（４１）の軸芯位置に内軸であるフォーク
軸（４５）を摺動自在に内挿させ、各ボールクラッチ
（３５）〜（３７）を択一係合動作させる突起であるシ
フタ（４６）をフォーク軸（４５）に設け、低中高速用
３段の副変速機構（４７）を形成するもので、フォーク
軸（４５）を軸芯方向に摺動させてシフタ（４６）を変
位させ、各ボールクラッチ（３５）〜（３７）を介して
低中高速用ギヤ（３８）〜（４０）を副変速軸（４１）
に択一係合させ、低速、中速、高速の出力切換を行うよ
うに構成している。【０００８】さらに、図１、図４、図７、図８、図９に
示す如く、前記フォーク軸（４５）の一端側に圧縮バネ
（４８）を巻装させ、フォーク軸（４５）の他端部をミ
ッションケース（３）外側方に出入自在に突設させると
共に、円筒形の固定カム（４９）と回転カム（５０）を
備え、ミッションケース（３）に回り止めピン（５１）
を介して固定カム（４９）を取付け、固定カム（４９）
中心部を遊嵌挿通させるフォーク軸（４５）端部にネジ
（５２）及びナット（５３）を介して回転カム（５０）
を回転自在に取付けるもので、回転カム（５０）に一体
固定させる副変速アーム（５４）を副変速レバー（１
１）に副変速ワイヤ（５５）を介して連結させ、また前
記アーム（５４）に戻りバネ（５５ａ）を連結させると
共に、多段的に形成する固定カム（４９）の低中高速カ
ムフロア平坦面（５６）（５７）（５８）に回転カム
（５０）のカム平坦面（５９）を対向させ、副変速レバ
ー（１１）操作によって回転カム（５０）をフォーク軸
（４５）回りに回転させ、低中高速カムフロア平坦面
（５６）〜（５８）のいずれかにカム平坦面（５９）を
択一当接させ、圧縮バネ（４８）に抗してフォーク軸
（４５）を進出させ、また前記バネ（４８）によってフ
ォーク軸（４５）を退入させ、前記シフタ（４６）によ
る低中高速の出力切換を行わせるように構成している。【０００９】上記から明らかなように、ミッションケー
ス（３）の外筒軸である副変速軸（４１）上にボールク
ラッチ（３５）〜（３７）を介して常時噛合い変速ギヤ
である低中高速用ギヤ（３８）〜（４０）を係脱自在に
軸支させると共に、副変速軸（４１）の軸芯位置に内軸
であるフォーク軸（４５）を摺動自在に挿通させ、ボー
ルクラッチ（３５）〜（３７）を係合動作させる突起で
あるシフタ（４６）をフォーク軸（４５）に設け、該フ
ォーク軸（４５）一端側をミッションケース（３）外部
に突出させて操作部材であるカム（４９）（５０）を取
付ける農用作業車において、ボールクラッチ（３５）〜
（３７）を係合動作させるシフタ（４６）をフォーク軸
（４５）に回転自在に取付けると共に、ミッションケー
ス（３）外側のフォーク軸（４５）に回転カム（５０）
を設け、該回転カム（５０）を副変速レバー（１１）に
副変速ワイヤ（５５）連結させ、前記フォーク軸（４
５）の軸芯回りに前記回転カム（５０）を回転させて前
記シフタ（４６）を変速動作させる。そして、前記回転
カム（５０）の設置スペースと、フォーク軸（４５）の
変速動作スペースをミッションケース（３）の外側に確
保するだけでコンパクトに構成し、従来のノブ構造のよ
うにミッションケース（３）の形状または大きさが制限
される不具合をなくし、また従来のシフタフォーク構造
のように複雑で高コストになる不具合をなくし、例えば
入力プーリ（１５）及び主変速及び副変速の各機構（３
３）（４７）を設けるミッションケース（３）に低コス
トでコンパクトに設置し、また従来のシフトフォーク構
造に比べて切換え遊びを少なくして操作効率を向上させ
る。【００１０】さらに、図４、図５、図７に示す如く、前
記副変速軸（４１）にスプロケット（６０）を一体形成
し、またボールクラッチ型サイドクラッチ（６１）（６
２）を介して車軸（５）にスプロケット（６３）を軸支
させ、各スプロケット（６０）（６３）をチェン（６
４）によって連結させると共に、サイドクラッチ（６
１）（６２）をバネ（６５）（６６）に抗して切操作す
るサイドクラッチアーム（６７）（６７）を設け、前記
サイドクラッチレバー（１２）にサイドクラッチワイヤ
（６８）を介してサイドクラッチアーム（６７）を連結
させ、前記レバー（１２）操作によってサイドクラッチ
（６１）（６２）を切動作させるように構成している。【００１１】上記のように、ミッションケース（３）の
副変速軸（４１）上にボールクラッチ（３５）〜（３
７）を介して変速ギヤである低中高速用ギヤ（３８）〜
（４０）を係脱自在に軸支させると共に、副変速軸（４
１）の軸芯位置にフォーク軸（４５）を挿通させ、ボー
ルクラッチ（３５）〜（３７）を係合動作させるシフタ
（４６）をフォーク軸（４５）に回転自在に取付け、、
該フォーク軸（４５）一端側をミッションケース（３）
外部に突出させて操作部材である固定カム（４９）及び
回転カム（５０）を取付けたもので、ミッションケース
（３）の左右幅略中央に前記フォーク軸（４１）のスプ
ロケット（６０）を配置させ、フォーク軸（４１）の左
半分に低中高速用ギヤ（３８）〜（４０）を取付け、フ
ォーク軸（４１）の右半分の周辺スペースを確保して主
変速１速ギヤ（２６）及び２速ギヤ（２７）などを配設
させると共に、前記フォーク軸（４５）とシフタ（４
６）の間で回転切れを行うことにより、フォーク軸（４
５）が回転しなくなり、従来のシフタボス及びシフタフ
ォークなどの操作手段に比べて操作効率が良くて部品数
が少ない前記カム（４９）（５０）によってフォーク軸
（４５）をミッションケース（３）外部から切換動作さ
せるように構成している。【００１２】【発明の効果】以上実施例から明らかなように本発明
は、ミッションケース（３）の外筒軸（４１）上にボー
ルクラッチ（３５）〜（３７）を介して常時噛合い変速
ギヤ（３８）〜（４０）を係脱自在に軸支させると共
に、外筒軸（４１）の軸芯位置に内軸（４５）を摺動自
在に挿通させ、ボールクラッチ（３５）〜（３７）を係
合動作させる突起（４６）を内軸（４５）に設け、該内
軸（４５）一端側をミッションケース（３）外部に突出
させて操作部材（４９）（５０）を取付ける農用作業車
において、ボールクラッチ（３５）〜（３７）を係合動
作させる突起（４６）を内軸（４５）に回転自在に取付
けると共に、ミッションケース（３）外側の内軸（４
５）にカム（５０）を設け、該カム（５０）を変速レバ
ー（１１）にワイヤ（５５）連結させ、前記内軸（４
５）の軸芯回りに前記カム（５０）を回転させて前記突
起（４６）を変速動作させるもので、前記カム（５０）
の設置スペースと、内軸（４５）の変速動作スペースを
ミッションケース（３）の外側に確保するだけでコンパ
クトに構成でき、従来のノブ構造のようにミッションケ
ース（３）の形状または大きさが制限される不具合をな
くすことができ、また従来のシフタフォーク構造のよう
に複雑で高コストになる不具合をなくすことができ、例
えば入力プーリ（１５）及び主変速及び副変速の各機構
（３３）（４７）を設けるミッションケース（３）に低
コストでコンパクトに設置でき、また従来のシフトフォ
ーク構造に比べて切換え遊びを少なくして操作効率を向
上させることができるものである。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an agricultural work vehicle equipped with, for example, a rotary work machine for tilling work. 2. Description of the Related Art Conventionally, Japanese Utility Model Laid-Open No. 2-107902 discloses
As shown in the figure, the ball
, And always engages and disengages the gearshift gear
At the same time, the inner shaft is slidably inserted into the shaft center position of the outer cylinder shaft.
On the inner shaft to engage the ball clutch.
The one end of the inner shaft to the outside of the transmission case
There is a technique for attaching an operation member . [0003] The object of the invention is to be Solved by the prior art, cable
Because it is a structure that pushes and pulls by providing a knob on the inner shaft outside the
Secure space for pushing and pulling the knob at the outer end of the inner shaft
And the shape or size of the case is likely to be limited.
For example, the input pulley and each mechanism of the main transmission and the auxiliary transmission
Make the mission case compact or simple
There is a problem that it cannot be easily performed. Therefore, JP
No.-6601 or Japanese Utility Model Laid-Open No. 50-84675
As shown in the report, swing the shifter fork into the transmission case.
The shifter boss is movably supported, and the shifter boss provided on the inner shaft is
Engage the fork pin and operate the lever shifter fork
There is also a structure to switch by, but a shifter fork is installed
Or secure the space for the exterior inside or outside the case
And the switching structure is complicated and costly.
Trouble . SUMMARY OF THE INVENTION Accordingly, the present invention provides a transmission gear that is always engaged with an outer cylinder shaft of a transmission case via a ball clutch so that the transmission gear can be freely engaged and disengaged. slidably is inserted the inner shaft in the axial position, provided on the inner shaft projections for engaging operation of the ball clutch, Ru attaching the operation member to protrude the inner shaft at one end to the transmission case outside
Engage ball clutch in agricultural work vehicle
The projection is rotatably mounted on the inner shaft,
A cam is provided on the inner shaft on the outside of the gear, and the cam is
The cam is rotated around the axis of the inner shaft.
The cam is installed by shifting the projection.
Space and the space for the shifting operation of the inner shaft
Can be made compact simply by securing it outside the
The shape or size of the transmission case like the knob structure of
Can be eliminated and the conventional shifter
Eliminates complicated and expensive defects like oak structure
For example, the input pulley and the main transmission and auxiliary transmission mechanisms
Low cost and compact installation in the mission case
Switchable and switchable compared to conventional shift fork construction
The operation efficiency can be improved by reducing the play . Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 is an explanatory view of a sub-transmission mechanism, FIG. 2 is a side view of a control device, FIG. 3 is a plan view of the same, FIG. 4 is an explanatory view of a transmission case upper part, FIG. 5 is an explanatory view of a lower part thereof, and FIG. FIG. 7 is an upper side view of a transmission case, in which (1) is an engine, (2) is an engine mount on which the engine (1) is mounted, and (3) is a front side of the engine mount (2). A transmission case (4) is mounted on both sides of the transmission case (3) via an axle (5), and a pair of left and right running wheels is mounted. (6) is mounted on the transmission case (3) via a hitch (7). Rotary working machine to be connected by traction,
(8) a steering handle connected to the upper part of the transmission case (3) via a handle base (9); (10)
Is a main shift lever that is supported by the transmission case (3) so as to be able to swing back and forth, (11) is a sub shift lever provided on the steering handle (8), (12) is a pair of left and right side clutch levers, (13) ) Is a traveling clutch lever, which is provided between an output pulley (14) of the engine (1) and an input pulley (15) of the transmission case (3) via a traveling clutch tension roller (16).
7), the output of the engine (1) is transmitted to the transmission case (3), and the rotary pawl (18) of the rotary working machine (6) is rotated to perform the tilling operation. . Further, as shown in FIGS. 4, 6, and 7, an input shaft (21) provided with an input pulley (15), a main transmission gear (19) and a PTO output pulley (20), and a shift fork (22). , A fork shaft (23) that slides the main transmission gear (19), a counter shaft (25) provided with a reverse gear (24), and first and second forward gears (26).
The main transmission shaft (28) provided with (27) is supported on the transmission case (3), and the first speed gear (26) supported on the main transmission shaft (28) by idle rotation is connected to the counter shaft (25) by the counter gear (25). 29) and (30), and the counter shaft (2
5) is connected to the main transmission shaft (28) by the counter gears (31) and (3).
The main transmission lever (10) is connected to the fork shaft (23) via the shift arm (34) to form a main transmission mechanism (33) of two forward steps and one reverse step. The main transmission lever (10) is operated to selectively engage the transmission gear (19) with the reverse gear (24), the first gear (26) or the second gear (27). Further, as shown in FIGS. 1, 4 and 6, a low-medium high-speed gear (38) which is a constantly meshing transmission gear that can be engaged and disengaged via ball clutches (35), (36) and (37).
(39) The auxiliary transmission shaft (4) which is an outer cylinder shaft provided with (40)
1) is rotatably supported by the transmission case (3), and the gears (38) to (40) are always meshed with the low, medium and high speed output gears (42), (43), and (44) of the main transmission shaft (28). A fork shaft (45), which is an inner shaft, is slidably inserted into the shaft center position of the auxiliary transmission shaft (41), and the ball clutches (35) to (37) are selectively engaged. A shifter (46) is provided on the fork shaft (45) to form a three-stage auxiliary transmission mechanism (47) for low, medium and high speeds. The shifter (46) is slid in the axial direction of the fork shaft (45). And the low, medium and high speed gears (38) to (40) are connected to the auxiliary transmission shaft (41) via the ball clutches (35) to (37).
To perform low-speed, medium-speed, and high-speed output switching. Further, as shown in FIGS. 1, 4, 7, 8, and 9, a compression spring (48) is wound around one end of the fork shaft (45), and the other end of the fork shaft (45) is The end is protruded to the outside of the transmission case (3) so as to be able to freely move in and out, and a cylindrical fixed cam (49) and a rotating cam (50) are provided.
The fixed cam (49) is attached via the fixed cam (49).
A rotary cam (50) is inserted through a screw (52) and a nut (53) into the end of a fork shaft (45) through which a central portion is loosely inserted.
The sub-transmission arm (54), which is integrally fixed to the rotating cam (50), is attached to the sub-transmission lever (1).
1) is connected via a sub-transmission wire (55), and a return spring (55a) is connected to the arm (54). 56) The flat cam surface (59) of the rotating cam (50) is opposed to (57) and (58), and the rotating cam (50) is rotated around the fork shaft (45) by operating the sub-transmission lever (11), and The cam flat surface (59) is selectively brought into contact with any of the medium to high speed cam floor flat surfaces (56) to (58), and the fork shaft (45) is advanced against the compression spring (48). The fork shaft (45) is retracted by (48) and low, medium and high speed output switching by the shifter (46) is performed. As is clear from the above, the mission case
Ball (3) on the auxiliary transmission shaft (41)
Constant meshing transmission gear via latches (35)-(37)
Gears (38) to (40) that can be freely disengaged
While supporting the shaft, the inner shaft is positioned at the center of the auxiliary transmission shaft (41).
Slidably inserted through the fork shaft (45)
Lugs (35)-(37)
A shifter (46) is provided on the fork shaft (45),
One end of the fork shaft (45) is outside the transmission case (3)
And cams (49) and (50) as operating members.
Agricultural work vehicle attached, ball clutch (35) ~
The shifter (46) for engaging the (37) with the fork shaft
(45) and freely attach
(3) Rotating cam (50) on outer fork shaft (45)
And the rotary cam (50) is attached to the sub-transmission lever (11).
The auxiliary transmission wire (55) is connected to the fork shaft (4).
5) rotate the rotary cam (50) around the axis of
The shifter (46) is shifted. And the rotation
Space for the cam (50) and the fork shaft (45)
Make sure that the shifting space is outside the transmission case (3).
It is compact just by holding it,
The shape or size of the mission case (3) is limited
Conventional shifter fork structure
Eliminates complicated and expensive problems such as
The input pulley (15) and the main transmission and auxiliary transmission mechanisms (3
3) Low cost for mission case (3) with (47)
Installation and compact design.
The switching play is reduced compared to the structure and the operation efficiency is improved.
You. Further, as shown in FIGS. 4, 5 and 7, a sprocket (60) is formed integrally with the auxiliary transmission shaft (41), and a ball clutch type side clutch (61) (6) is formed.
The sprocket (63) is supported on the axle (5) via 2), and each sprocket (60) (63) is connected to the chain (6).
4) and the side clutch (6)
1) A side clutch arm (67) (67) for disengaging the (62) against the springs (65) and (66) is provided, and the side clutch lever (12) is connected to the side clutch wire (68) via a side clutch wire (68). The clutch arm (67) is connected, and the side clutches (61) and (62) are disengaged by operating the lever (12). As described above, the ball clutches (35) to (3) are mounted on the auxiliary transmission shaft (41) of the transmission case (3).
7) through low-, medium-, and high-speed gears (38) through
(40) is supported so as to be freely disengageable and the auxiliary transmission shaft (4
The fork shaft (45) is inserted through the shaft center position of 1), and the shifter (46) for engaging the ball clutches (35) to (37) is rotatably mounted on the fork shaft (45),
Attach one end of the fork shaft (45) to the transmission case (3).
A fixed cam (49) and a rotating cam (50), which are operation members, are mounted so as to protrude to the outside, and the sprocket (60) of the fork shaft (41) is arranged at substantially the center in the left and right width of the transmission case (3). Gears (38) to (40) are attached to the left half of the fork shaft (41), and a space around the right half of the fork shaft (41) is secured to secure the first speed gear (26) for the main transmission and A second speed gear (27) and the like are provided, and the fork shaft (45) and the shifter (4) are arranged.
6), the fork shaft (4
5) does not rotate, and the fork shaft (45) is moved outside the transmission case (3) by the cams (49) and (50) which have a higher operation efficiency and a smaller number of parts than conventional operation means such as a shifter boss and a shifter fork. , The switching operation is performed. As is apparent from the above embodiments, the present invention provides a constant mesh transmission on the outer cylinder shaft (41) of the transmission case (3) via the ball clutches (35) to (37). The gears (38) to (40) are rotatably supported and the inner shaft (45) is slidably inserted into the axial center position of the outer cylinder shaft (41), and the ball clutches (35) to (37). ) is provided to the inner shaft projections (46) for engaging operation (45), said inner shaft (45) one end side of the transmission case (3) operation to protrude to the outside member (49) (50) to install them for agricultural and Work vehicle
, The ball clutches (35) to (37)
The rotatable projection (46) is rotatably mounted on the inner shaft (45).
And the inner shaft (4) outside the transmission case (3).
5) is provided with a cam (50), and the cam (50) is
-(11) is connected to the wire (55) and the inner shaft (4
The collision is rotated around its axis said cam (50) of 5)
Force (46) in the one which shift operation, the cam (50)
Installation space and inner shaft (45) speed change operation space
Just secure outside the transmission case (3)
And a mission case like a conventional knob structure.
There is no problem that the shape or size of the case (3) is restricted.
It can be combed and has the same structure as a conventional shifter fork.
Can eliminate complicated and expensive problems
For example, the input pulley (15) and each mechanism of the main speed change and the auxiliary speed change
(33) Low on mission case (3) with (47)
It can be installed compactly at low cost, and can
Switching play and operating efficiency
Are those that can Rukoto to above.

【図面の簡単な説明】【図１】副変速機構部の説明図。【図２】管理機の側面図。【図３】同平面図。【図４】ミッションケース上部説明図。【図５】同下部説明図。【図６】主変速機構部の説明図。【図７】ミッションケース上部側面図。【図８】副変速カム部の分解図。【図９】同展開説明図。【符号の説明】（３）ミッションケース（１１）副変速レバー（３５）〜（３７）ボールクラッチ（３８）〜（４０）低中高速用ギヤ（変速ギヤ）（４１）副変速軸（外筒軸）（４５）フォーク軸（内軸）（４６）シフタ（突起）（４９）固定カム（操作部材）（５０）回転カム（操作部材）（５５）副変速ワイヤ BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram of a subtransmission mechanism. FIG. 2 is a side view of the management device. FIG. 3 is a plan view of the same. FIG. 4 is an explanatory view of a transmission case upper part. FIG. 5 is an explanatory view of the lower part. FIG. 6 is an explanatory diagram of a main transmission mechanism. FIG. 7 is a top view of a transmission case. FIG. 8 is an exploded view of a sub speed change cam portion. FIG. 9 is a development explanatory view of the same. [Description of Signs] (3) Transmission case (11) Sub-transmission levers (35) to (37) Ball clutches (38) to (40) Low, medium and high-speed gears (transmission gear) (41) Sub-transmission shaft (outer cylinder) Shaft) (45) Fork shaft (inner shaft) (46) Shifter (projection) (49) Fixed cam (operating member) (50) Rotating cam (operating member) (55) Sub-transmission wire

フロントページの続き (56)参考文献特開昭52−6601（ＪＰ，Ａ) 実開平２−107902（ＪＰ，Ｕ) 実開昭50−84675（ＪＰ，Ｕ) (58)調査した分野(Int.Cl.⁷，ＤＢ名) A01B 33/08 B60K 17/08 F16D 15/00 Continuation of the front page (56) References JP-A-52-6601 (JP, A) JP-A 2-107902 (JP, U) JP-A 50-84675 (JP, U) (58) Fields investigated (Int) .Cl. ⁷ , DB name) A01B 33/08 B60K 17/08 F16D 15/00

Claims

(57) [Claims 1] An outer cylinder shaft (4) of a transmission case (3).
1) The normally meshing transmission gears (38) to (40) are rotatably supported on the upper side via ball clutches (35) to (37), and the transmission gears (38) to (40) are supported at the center of the outer cylinder shaft (41). Shaft (4
5) is slidably inserted through the ball clutch (35) ~
The protrusion (46) for engaging the (37) is operated by the inner shaft (45).
To provided, in the inner shaft (45) one end side of the transmission case (3) projecting to the outside operating member (49) (50) preparative <br/> with that agricultural work vehicle, a ball clutch (35) -
The protrusion (46) for engaging the (37) is operated by the inner shaft (45).
And the transmission case (3)
A cam (50) is provided on the outer inner shaft (45), and the cam (5) is provided.
0) is connected to the transmission lever (11) by the wire (55),
The cam (50) is rotated around the axis of the inner shaft (45).
The agricultural work vehicle wherein the protrusion (46) is operated to change the speed .