JP2001086803A - Steering apparatus for working vehicle - Google Patents
Steering apparatus for working vehicleInfo
- Publication number
- JP2001086803A JP2001086803A JP26574899A JP26574899A JP2001086803A JP 2001086803 A JP2001086803 A JP 2001086803A JP 26574899 A JP26574899 A JP 26574899A JP 26574899 A JP26574899 A JP 26574899A JP 2001086803 A JP2001086803 A JP 2001086803A
- Authority
- JP
- Japan
- Prior art keywords
- wheel
- steering
- support
- wheel support
- vehicle body
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Guiding Agricultural Machines (AREA)
- Steering-Linkage Mechanisms And Four-Wheel Steering (AREA)
Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明は、左右車輪の車体に
対する取り付け向きを変更することによって車体の操向
操作を行う作業車の操向装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering apparatus for a working vehicle that performs a steering operation of a vehicle body by changing the mounting directions of right and left wheels with respect to the vehicle body.
【0002】[0002]
【従来の技術】たとえば農用トラクタでは、枕地を小さ
い旋回半径で旋回走行すると、枕地が小さくなるとか、
枕地の移動が迅速に行えるなど有利に走行できる。この
ため、従来、たとえば実開昭56−36574号公報や
USP5046577に示される操向技術があった。こ
の操向技術は、両端側に車輪を車体上下向きの操向軸芯
まわりで揺動自在に支持する車軸部材を、車体の左右方
向での中心部に車体上下向きの軸芯まわりで回動自在に
支持させ、この車軸部材の車体に対する取り付け向きの
変更と、左右車輪の車軸部材に対する取り付け向きの変
更とによって、左右車輪の車体に対する取り付け向きを
変更して車体の操向操作を行うものである。そして、車
輪の車体に対する向き変更を、車輪の車軸部材に対する
向き変更と、車軸部材の車体に対する向き変更との両方
によって行うことにより、車輪の車軸部材に対する向き
変更だけで行うよりも、車輪の最大切れ角が大になって
旋回半径が小さくなるものである。2. Description of the Related Art In an agricultural tractor, for example, when a headland is turned with a small turning radius, the headland becomes smaller,
It can run advantageously, for example, the headland can be moved quickly. For this reason, conventionally, there has been a steering technique disclosed in, for example, Japanese Utility Model Laid-Open Publication No. 56-36574 and US Pat. No. 5,046,577. In this steering technology, an axle member that supports the wheels at both ends so as to be swingable around a vertical steering axis of the vehicle body is rotated around a vertical axis of the vehicle body at the center in the left-right direction of the vehicle body. The steering direction of the vehicle body is changed by changing the mounting direction of the left and right wheels to the vehicle body by changing the mounting direction of the axle member to the vehicle body and changing the mounting direction of the left and right wheels to the axle member. is there. By changing the direction of the wheels with respect to the vehicle body by performing both the direction change of the wheels with respect to the axle member and the direction change of the axle members with respect to the vehicle body, the maximum change of the wheels can be achieved rather than performing the direction change of the wheels only with respect to the axle members. The turning angle becomes large and the turning radius becomes small.
【0003】[0003]
【発明が解決しようとする課題】上記した従来の操向技
術の場合、操向操作を行うと、左右車輪が走行地面に対
して大きく横すべりしながら車体に対して向き変更して
いた。また、左右車輪が車体に対してローリングするこ
とを可能にするには、車軸部材を車体前後向きの軸芯ま
わりでも揺動するように車体に支持させる必要があるこ
とから、車軸部材を車体に取付ける構造が複雑になると
ともに、この取付け構造には高い支持強度を備えさせる
必要があり、コスト面や重量面で不利になっていた。本
発明の目的は、車輪の切れ角を大きくできるのみなら
ず、その割りには、車輪の横すべりを少なく抑制できる
とともに、比較的安価かつ軽量に車輪のローリングを可
能にできる作業車の操向装置を提供することにある。In the conventional steering technique described above, when a steering operation is performed, the left and right wheels change directions with respect to the vehicle body while sliding largely on the running ground. Also, in order to enable the left and right wheels to roll with respect to the vehicle body, it is necessary to support the axle member on the vehicle body so as to swing also around the longitudinal axis of the vehicle body. The mounting structure has become complicated, and the mounting structure has to be provided with high supporting strength, which is disadvantageous in terms of cost and weight. SUMMARY OF THE INVENTION An object of the present invention is to provide a steering apparatus for a working vehicle that can not only increase the turning angle of a wheel, but also reduce the side slip of the wheel, and enable relatively inexpensive and lightweight rolling of the wheel. Is to provide.
【0004】[0004]
【課題を解決するための手段】請求項1による発明の構
成、作用、効果はつぎのとおりである。The constitution, operation and effect of the invention according to claim 1 are as follows.
【0005】〔構成〕車体の左右の車輪支持部に各別に
車体上下向きの第1操向軸芯まわりで揺動自在に支持さ
れている左右一対の中間支持体と、前記左側の中間支持
体の遊端側に車体上下向きの第2操向軸芯まわりで揺動
自在に支持されているとともに左車輪を車軸芯まわりで
回動自在に支持している車輪支持体と、前記右側の中間
支持体の遊端側に車体上下向きの第2操向軸芯まわりで
揺動自在に支持されているとともに右車輪を車軸芯まわ
りで回動自在に支持している車輪支持体とを備え、前記
左右の中間支持体を前記第1操向軸芯まわりで揺動操作
するとともに前記左右の車輪支持体を前記第2操向軸芯
まわりで揺動操作して左右車輪を操向操作する操向操作
機構を備えてある作業車の操向装置。[Structure] A pair of left and right intermediate supports respectively supported by left and right wheel support portions of a vehicle body so as to be swingable around a first steering axis centering vertically on the vehicle body, and the left intermediate support member A wheel supporter rotatably supported on a free end side of the vehicle body around a second steering axis centering vertically and supporting the left wheel rotatably around the axle axis; A wheel support that is supported on the free end side of the support so as to be swingable around a second steering axis centering vertically on the vehicle body and that supports the right wheel so as to be rotatable around the axle axis; A swing operation of the left and right intermediate supports around the first steering axis and a swing operation of the left and right wheel supports around the second steering axis to steer the left and right wheels; A steering device for a work vehicle provided with a steering operation mechanism.
【0006】〔作用〕操向操作を行うと、操向操作機構
が左右の中間支持体それぞれを第1操向軸芯まわりで車
輪支持部に対して揺動操作するとともに左右の車輪支持
体それぞれを第2操向軸芯まわりで中間支持体に対して
揺動操作し、中間支持体の車体に対する向き変更と、車
輪の中間支持体に対する向き変更との両方の向き変更に
よって、左右車輪の車体に対する取り付け向きが変化す
る。これにより、左右車輪を操向操作するのに、第2操
向軸芯のまわりでの向き変更だけで操向操作するものよ
りも最大切れ角が大になるようにして操向操作できる。[Operation] When the steering operation is performed, the steering operation mechanism swings the left and right intermediate supports around the first steering axis with respect to the wheel supporting portions, and simultaneously operates the left and right wheel supports. Is pivoted about the second steering axis with respect to the intermediate support, and both the change of the orientation of the intermediate support with respect to the vehicle body and the change of the orientation of the wheels with respect to the intermediate support allow the left and right wheels to rotate. The mounting direction with respect to changes. Thus, when the left and right wheels are steered, the steering operation can be performed such that the maximum turning angle becomes larger than that when the steering operation is performed only by changing the direction around the second steering axis.
【0007】さらに、中間支持体は車体の左又は右側に
位置する車輪支持部に揺動自在に支持されているものだ
から、第2操向軸芯が車輪の揺動軸芯となり、この車輪
揺動軸芯が車体に対して前後に移動する際の支点に第1
操向軸芯がなる。すなわち、移動支点から車輪揺動軸芯
までの距離が、従来の移動支点である車軸部材の揺動軸
芯から車輪揺動軸芯までの距離よりも短距離になり、左
右車輪が向き変更する際に走行地面に対して横すべりす
る長さを従来より短くしながら、左右車輪を操向操作で
きる。Further, since the intermediate support is swingably supported by a wheel support portion located on the left or right side of the vehicle body, the second steering axis becomes a swing axis of the wheel. The fulcrum when the moving shaft center moves back and forth with respect to the body
The steering axis becomes. That is, the distance from the moving fulcrum to the wheel oscillating axis is shorter than the distance from the oscillating axis of the axle member, which is a conventional moving fulcrum, to the wheel oscillating axis, and the left and right wheels change directions. In this case, the left and right wheels can be steered while the length of the side slip on the traveling ground is shorter than before.
【0008】車体に車体前後向きの軸芯まわりで揺動自
在に支持される車軸部材を設け、この車軸部材の一端側
で左側の車輪支持部を、他端側で右側の車輪支持部をそ
れぞれ形成する。すると、車軸部材は、車体に対して中
間部で車体前後向きの軸芯まわりで回動自在に連結する
だけのものでありながら、左右車輪が車輪支持体の第2
操向軸芯まわりでの揺動と、中間支持体の第1操向軸芯
まわりでの揺動とによって向き変更するとともに、車輪
支持体、中間支持体及び車軸部材を介して車体に対して
ローリングする。An axle member is provided on the vehicle body so as to be swingable about a longitudinal axis of the vehicle body, and a left wheel support portion is provided at one end of the axle member and a right wheel support portion is provided at the other end. Form. Then, while the axle member is merely connected to the vehicle body at an intermediate portion so as to be rotatable around a longitudinal axis of the vehicle body, the left and right wheels are the second members of the wheel support.
The direction is changed by the swing around the steering axis and the swing of the intermediate support around the first steering axis, and the body is changed with respect to the vehicle body via the wheel support, the intermediate support and the axle member. Rolling.
【0009】〔効果〕左右車輪の車体に対する向き変更
を車輪の第2操向軸芯まわりでの揺動のみによって行う
よりも大きな切れ角まで左右車輪を操向操作できること
により、枕地で小旋回半径で旋回走行して枕地を小さく
したり、先の作業終了箇所から次の作業開始箇所まで迅
速に移動するなど有利に走行しながら作業できる。しか
も、車輪が向き変更する際の走行地面に対する横すべり
を車軸部材が車体の左右中心部で揺動する従来よりも少
なく抑制しながら車体操向を行い、その横すべりによる
操向や走行不良が発生しにくいとか少ないように安定し
た状態で走行できる。[Effect] The left and right wheels can be steered to a larger turning angle than when the directions of the left and right wheels with respect to the vehicle body are changed only by swinging of the wheels around the second steering axis. It is possible to work while traveling advantageously, such as turning around the radius to make the headland smaller, or moving quickly from the previous work end point to the next work start point. In addition, steering is performed while the axle member suppresses side slip on the running ground when the direction of the wheels changes, as compared with the conventional case where the axle member swings at the left and right center of the body, and steering and running defects due to the side slip occur. It can run in a stable state with little or no difficulty.
【0010】さらに、走行地面の凹凸や傾斜にかかわら
ず車体を水平やほぼ水平に保ちながら走行できるように
左右車輪のローリングを可能にする場合、左右の車輪支
持部を形成する車軸部材を、この車軸部材の車体に対す
る上下揺動を可能にするだけの構造簡単な取付け構造に
よって車体に連結すればよくて、安価かつ軽量に得られ
る。Further, when rolling of the left and right wheels is enabled so that the vehicle can run while keeping the vehicle body horizontal or substantially horizontal regardless of the unevenness or inclination of the running ground, an axle member forming left and right wheel support portions is provided. A structure that allows the axle member to swing up and down with respect to the vehicle body can be connected to the vehicle body by a simple mounting structure, and it is inexpensive and lightweight.
【0011】請求項2による発明の構成、作用、効果は
つぎのとおりである。The construction, operation and effect of the invention according to claim 2 are as follows.
【0012】〔構成〕請求項1による発明の構成におい
て、前記左右車輪が直進向きにある状態で前記第2操向
軸芯が前記第1操向軸芯よりも車体前後方向に位置ずれ
している。In the configuration according to the first aspect of the present invention, the second steering axis is displaced in the longitudinal direction of the vehicle body from the first steering axis in a state where the left and right wheels are in the straight traveling direction. I have.
【0013】〔作用〕車輪の取り付け向きを外向きに変
更する場合、車輪が第2操向軸芯まわりで揺動するに伴
い、車輪の前後一端側が車輪より内側に位置する車体な
どの内側部材に近づいていき、いずれはその内側部材に
当たる。車輪が前車輪である場合、車輪が直進向きにあ
る状態で第2操向軸芯が第1操向軸芯よりも車体前方側
に位置ずれしていると、車輪を直進向きから外向きに操
向操作する際、当初において車輪の接地点が第2操向軸
芯のまわりで車体外側に出ていく。これに対し、第2操
向軸芯が第1操向軸芯と車体横方向に並んでいると、車
輪を直進向きから外向きに操向操作する際、常に車輪の
接地点が第2操向軸芯のまわりで車体内側に入り込んで
いく。このため、車輪が直進向きの位置から内側部材に
当たるまでに中間支持体を第1操向軸芯まわりで揺動操
作できる角度が、前者のものの方が大になる。そして、
車輪が後車輪である場合、車輪が直進向きにある状態で
第2操向軸芯が第1操向軸芯よりも車体後方側に位置ず
れしていると、車輪を直進向きから外向きに操向操作す
る際、当初において車輪の接地点が第2操向軸芯のまわ
りで車体外側に出ていく。これに対し、第2操向軸芯が
第1操向軸芯と車体横方向に並んでいると、車輪を直進
向きから外向きに操向操作する際、常に車輪の接地点が
第2操向軸芯のまわりで車体内側に入り込んでいく。こ
のため、車輪が直進向きの位置から内側部材に当たるま
でに中間支持体を第1操向軸芯まわりで揺動操作できる
角度が、前者のものの方が大になる。これにより、車輪
が直進向きにある状態で第2操向軸芯が第1操向軸芯よ
りも車体前後方向に位置ずれしている方が、車体横方向
に並んでいる場合よりも、最大切れ角が大になるように
して左右車輪を操向操作できる。[Operation] When the mounting direction of the wheels is changed to the outward direction, as the wheels swing around the second steering axis, the front and rear ends of the wheels are located inside the wheels. And eventually hit its inner member. When the wheel is a front wheel, if the second steering axis is displaced to the front side of the vehicle body with respect to the first steering axis in a state where the wheel is in the straight traveling direction, the wheel is moved outward from the straight traveling direction. When the steering operation is performed, the ground contact point of the wheel initially goes out of the vehicle body around the second steering axis. On the other hand, when the second steering axis is aligned with the first steering axis in the lateral direction of the vehicle body, the ground contact point of the wheel always moves to the second steering point when the wheel is steered from straight ahead to outward. It penetrates the inside of the car body around the opposing axis. For this reason, the angle at which the intermediate support body can swing around the first steering axis from the position where the wheel moves straight ahead to the inner member becomes larger in the former case. And
When the wheel is the rear wheel, if the second steering axis is displaced to the rear side of the vehicle body with respect to the first steering axis in a state where the wheel is in the straight traveling direction, the wheel is moved outward from the straight traveling direction. When the steering operation is performed, the ground contact point of the wheel initially goes out of the vehicle body around the second steering axis. On the other hand, when the second steering axis is aligned with the first steering axis in the lateral direction of the vehicle body, the ground contact point of the wheel always moves to the second steering point when the wheel is steered from straight ahead to outward. It penetrates the inside of the car body around the opposing axis. For this reason, the angle at which the intermediate support body can swing around the first steering axis from the position where the wheel moves straight ahead to the inner member becomes larger in the former case. Accordingly, when the second steering axis is displaced in the front-rear direction of the vehicle body with respect to the first steering axis in a state where the wheels are in the straight traveling direction, the maximum is larger than when the wheels are aligned in the lateral direction of the vehicle body. The left and right wheels can be steered so that the turning angle is large.
【0014】〔効果〕左右車輪の切れ角を第1操向軸芯
と第2操向軸芯の配置の面からも大にしてより小さい旋
回半径で旋回走行し、枕地をより一層小さくなるなどし
て有利に走行できる。[Effect] The turning angle of the left and right wheels is increased from the plane of the arrangement of the first steering axis and the second steering axis, and the vehicle turns with a smaller turning radius, and the headland is further reduced. It is possible to run advantageously.
【0015】請求項3による発明の構成、作用、効果は
つぎのとおりである。The construction, operation and effect of the invention according to claim 3 are as follows.
【0016】〔構成〕請求項1又は2による発明の構成
において、前記車輪支持体と前記中間支持体の一方をス
テアリングハンドルに連係させている操作機構と、前記
車輪支持体と前記中間支持体の他方を前記操作機構に連
動させている連動機構とを、前記操向操作機構に備えて
ある。[0016] [Constitution] In the constitution of the invention according to claim 1 or 2, an operation mechanism for linking one of the wheel support and the intermediate support to a steering handle, and an operation mechanism for the wheel support and the intermediate support. An interlocking mechanism that interlocks the other with the operation mechanism is provided in the steering operation mechanism.
【0017】〔作用〕ステアンリングハンドルを操作す
ると、操作機構による連係によって車輪支持体と中間支
持体のいずれか一方が揺動し、連動機構による連動のた
めに他方が一方の揺動に連動して揺動して、左右車輪を
操向操作できる。すなわち、中間支持体と車輪支持体と
を各別にステアリングハンドルに連係させるに比して構
造面や制御面で簡単なものに操向操作機構を構成しなが
ら、ステアリングハンドルによって車輪支持体と中間支
持体とを連動させて操作できる。[Operation] When the steering ring handle is operated, one of the wheel support and the intermediate support swings by the linkage of the operating mechanism, and the other swings with one of the swings due to the linkage by the linkage mechanism. To swing and steer the left and right wheels. In other words, while the steering operation mechanism is simpler in terms of structure and control compared to separately linking the intermediate support and the wheel support to the steering handle, the wheel support and the intermediate support are formed by the steering handle. Can be operated in conjunction with the body.
【0018】〔効果〕左右車輪の最大切れ角を大にして
操向操作できるものを、操向操作機構の面から構造簡単
かつ安価に得られる。[Effect] A steering device capable of increasing the maximum turning angle of the left and right wheels and performing the steering operation can be obtained with a simple structure at a low cost in terms of the steering operation mechanism.
【0019】請求項4による発明の構成、作用、効果は
つぎのとおりである。The structure, operation and effect of the invention according to claim 4 are as follows.
【0020】〔構成〕請求項3による発明の構成におい
て、前記連動機構が、前記車輪支持体と前記中間支持体
の他方と、前記車輪支持部とにわたって取り付けた揺動
リンクを備えるリンク式である。[Structure] In the structure of the invention according to claim 3, the interlocking mechanism is a link type having a swing link attached to the other of the wheel support and the intermediate support and the wheel support. .
【0021】〔作用〕揺動リンクの長さや取り付け角な
どを適切に設定すると、たとえば中間支持体の揺動に連
動して車輪支持体が揺動するように、かつ、中間支持体
が単位角度を揺動するに伴って車輪支持体が揺動する角
度が中間支持体の揺動位置によって異なるように、中間
支持体と車輪支持体とを連動させ、ステアリングハンド
ルの単位角度の操作に伴って車輪が第2操向軸芯まわり
で揺動して向き変化する角度が、車輪の切れ角が小さい
範囲と大きい範囲とで異なるようにした状態で車輪を操
向操作することができるものである。[Operation] When the length and the mounting angle of the swing link are appropriately set, for example, the wheel support swings in conjunction with the swing of the intermediate support, and the intermediate support is rotated by a unit angle. The intermediate support and the wheel support are interlocked so that the angle at which the wheel support swings with the swing of the intermediate support depends on the swing position of the intermediate support. It is possible to steer the wheel in a state where the angle at which the wheel swings around the second steering axis and changes its direction is different between a range where the turning angle of the wheel is small and a range where the turning angle is large. .
【0022】〔効果〕ステアリングハンドルの操作量の
割りには車輪向きの変化が大になったり小になる状態が
リンクによって得られ、ステアリングハンドルをわずか
に操作するだけで車輪向きが大きく変化して小回り旋回
するとか、ステアリングハンドルをわずかに操作しただ
けでは車輪向きがあまり変化しなくて蛇行しにくいなど
の状態を構造簡単に得られる。[Effect] A state in which the change of the wheel direction becomes large or small is obtained by the link in the division of the operation amount of the steering wheel, and the wheel direction changes greatly by slightly operating the steering wheel. It is possible to easily obtain a state in which a small turning operation or a slight operation of the steering wheel does not change the direction of the wheels so much that it is difficult to meander.
【0023】請求項5による発明の構成、作用、効果は
つぎのとおりである。The structure, operation and effect of the invention according to claim 5 are as follows.
【0024】〔構成〕請求項3による発明の構成におい
て、前記連動機構が、前記車輪支持体と前記中間支持体
の他方が一体回動自在に備えるギヤと、このギヤに噛み
合う状態で前記車輪支持部に固定されているギヤとを備
えるギヤ式である。In the structure according to the third aspect of the present invention, the interlocking mechanism includes a gear provided with the other of the wheel support and the intermediate support so as to be rotatable integrally with the wheel support. And a gear fixed to the section.
【0025】〔作用〕たとえば中間支持体の揺動に連動
して車輪支持体が揺動するように、かつ、中間支持体と
車輪支持体の連動比が中間支持体の揺動位置によって変
化しないように、中間支持体と車輪支持体とを連動さ
せ、ステアリングハンドルの単位角度の操作に伴って車
輪が第2操向軸芯まわりで揺動して向き変化する角度
が、車輪の切れ角が大小如何なる範囲におていも一定に
なるようにした状態で車輪を操向操作することができる
ものである。[Operation] For example, the wheel support swings in conjunction with the swing of the intermediate support, and the interlocking ratio between the intermediate support and the wheel support does not change depending on the swing position of the intermediate support. In this way, the intermediate support and the wheel support are interlocked, and the angle at which the wheel swings around the second steering axis and changes direction with the operation of the unit angle of the steering handle is determined by the turning angle of the wheel. The steering operation of the wheels can be performed in a state where the wheel is constant regardless of the size of the vehicle.
【0026】〔効果〕ステアリングハンドルの操作量
と、車輪向きの変化量との関係が一定になる状態がギヤ
連動によって得られ、ステアリングハンドルを大きく操
作すると車輪向きが大きく変化して小回り旋回し、ステ
アリングハンドルをわずかに操作しただけでは車輪向き
があまり変化しなくて蛇行しにくいなどの状態を構造簡
単に得られる。[Effect] A state in which the relationship between the amount of operation of the steering wheel and the amount of change in the wheel direction is constant is obtained by gear interlocking. When the steering wheel is largely operated, the wheel direction changes greatly and the vehicle turns slightly. A simple operation of the steering handle can easily obtain a state in which the wheel direction does not change much and the vehicle does not meander easily.
【0027】請求項6による発明の構成、作用、効果は
つぎのとおりである。The structure, operation and effect of the invention according to claim 6 are as follows.
【0028】〔構成〕請求項1〜5のいずれか1項によ
る発明の構成において、前記左右の車輪支持部、中間支
持体及び車輪支持体を、左右車輪に駆動力を伝達する車
輪駆動ケースによって構成し、車輪支持部を構成する駆
動ケース部が備える伝動軸と、中間支持体を構成する駆
動ケース部が備える伝動軸とを連結するとともに前記第
1操向軸芯と同一の軸芯まわりで屈曲する自在継手を備
えてある。[Configuration] In the configuration of the invention according to any one of claims 1 to 5, the left and right wheel support portions, the intermediate support and the wheel support are separated by a wheel drive case for transmitting a driving force to the left and right wheels. And a drive shaft provided in a drive case section constituting a wheel support section, and a transmission shaft provided in a drive case section constituting an intermediate support body, and connected around the same axis as the first steering axis. It has a universal joint that bends.
【0029】〔作用〕中間支持体と車輪支持部とが第2
操向軸芯まわりで回動自在に連結する部分を、内部に自
在継手を収容するだけの比較的コンパクトなものにしな
がら、左右車輪を駆動輪にするものである。[Operation] The intermediate support and the wheel support portion are
The left and right wheels are used as drive wheels while the portion rotatably connected around the steering axis is made relatively compact enough to accommodate a universal joint therein.
【0030】〔効果〕左右車輪が切れ角の大きい範囲ま
で操向操作された際には、他の非操向型の駆動車輪より
も高速の周速度になる状態で駆動されるように構成し、
小旋回半径で旋回走行する際には、左右車輪の切れ角の
大きさと、左右車輪の高速駆動との両方によってより小
回り旋回できるすることができる。その割りには、中間
支持体と車輪支持部とが連結する部分をコンパクトなも
のにし、この連結部分が地上高の高いものになって接地
しにくように有利に走行したり、構造面やコスト面で有
利に得られる。[Effects] When the left and right wheels are steered to a range where the turning angle is large, the wheels are driven at a peripheral speed higher than that of the other non-steered driving wheels. ,
When turning with a small turning radius, it is possible to make a smaller turn by both the magnitude of the turning angle of the left and right wheels and the high-speed driving of the left and right wheels. For that reason, the part where the intermediate support and the wheel support part are connected is made compact, and this connected part becomes high above the ground and runs advantageously to make it difficult to touch the ground, Advantageously obtained in terms of cost.
【0031】[0031]
【発明の実施の形態】図1に示すように、左右一対の駆
動自在な前車輪1,1、左右一対の駆動自在な非操向型
の後車輪2,2、エンジン3やエンジンボンネット4を
有する原動部、ステアリングハンドル5や運転座席6を
有する運転部のそれぞれを備えている車体の後部を形成
しているミッションケース7の後部に、リフトシリンダ
(図示せず)によって上下に揺動操作自在なリフトアー
ム8、動力取り出し軸9を設けて、農用トラクタを構成
してある。このトラクタは、車体の後部にロータリ耕耘
装置などの各種の作業装置を前記リフトアーム8によっ
て昇降操作自在に連結し、この連結作業装置に前記動力
取り出し軸9によって回動力を伝達するものである。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a pair of left and right drivable front wheels 1, 1, a pair of left and right drivable non-steering rear wheels 2, 2, an engine 3 and an engine hood 4 are shown. A lift cylinder (not shown) is used to freely swing up and down by a lift cylinder (not shown) at a rear portion of a transmission case 7 forming a rear portion of a vehicle body having a driving unit having a steering handle 5 and a driving seat 6. An agricultural tractor is provided by providing a simple lift arm 8 and a power take-out shaft 9. In this tractor, various working devices such as a rotary tilling device are connected to a rear portion of a vehicle body by a lift arm 8 so as to be able to move up and down freely, and rotating power is transmitted to the connected working device by the power take-out shaft 9.
【0032】図2〜図5に示すように、前記左右前輪
1,1を各別に両端側に支持する前車軸部材に兼用の車
輪駆動ケース10の長手方向での中間部を前記車体の前
部に取り付けてある。すなわち、車輪駆動ケース10の
長手方向での中間部に前後一対の筒軸型の連結軸11,
12を備えさせ、前側の連結軸11を、前記車体の前部
を形成している前車体フレーム20が支持する前側支持
体21のボス部21aに車体前後向きの軸芯Xまわりで
回動自在に内嵌させ、後側の連結軸12を、前記前車体
フレーム20が支持する後側支持体22のボス部22a
に前記軸芯Xと同一の軸芯まわりで回動自在に内嵌させ
てある。つまり、左右前輪1,1は、一方の前車輪1が
車体に対して前記軸芯Xまわりで下降すると他方の前車
輪1が車体に対して前記軸芯Xまわりで上昇するように
前記軸芯Xをローリング軸芯としてローリング自在に車
体に支持させてある。これにより、左右前輪1,1の一
方が走行地面の凹入部に入り込んだり凸部に乗り上がる
とか、走行地面が車体左右方向に傾斜していても、左右
前輪1,1がローリングし、車体の左右方向での姿勢が
水平又はそれに近い姿勢に維持される。As shown in FIGS. 2 to 5, an intermediate portion in the longitudinal direction of the wheel drive case 10, which is also used as a front axle member for supporting the left and right front wheels 1, 1 at both ends, is a front portion of the vehicle body. It is attached to. That is, a pair of front and rear cylindrical shaft type connecting shafts 11 are provided at an intermediate portion in the longitudinal direction of the wheel drive case 10.
And a boss portion 21a of a front support 21 supported by a front vehicle body frame 20 forming a front portion of the vehicle body, and the front connection shaft 11 is rotatable around an axis X in the vehicle front-rear direction. And a boss portion 22a of a rear support 22 that supports the rear connecting shaft 12 with the front body frame 20.
Is rotatably fitted around the same axis as the axis X. In other words, the left and right front wheels 1 and 1 are arranged such that when one front wheel 1 descends around the axis X with respect to the vehicle body, the other front wheel 1 rises around the axis X with respect to the vehicle body. X is the rolling axis and is supported on the vehicle body in a freely rolling manner. Thereby, even if one of the left and right front wheels 1, 1 enters into the recessed portion of the running ground or rides on the convex portion, or if the running ground is inclined in the lateral direction of the vehicle body, the left and right front wheels 1, 1 roll, and The posture in the left-right direction is kept horizontal or close to it.
【0033】前記車輪駆動ケース10を、前記前後の連
結軸11,12を中間部に備える基端駆動ケース部13
と、この基端駆動ケース部13の両端側に各別に連結す
る左右一対の中間支持体14を構成する中間駆動ケース
部と、左側の中間支持体14に連結する車輪支持体15
を構成する先端駆動ケース部と、右側の中間支持体14
に連結する車輪支持体15を構成する先端駆動ケース部
との5つのケース部によって構成して、操向装置を構成
してある。この操向装置は、左右の中間支持体14、1
4に各別に連結する一対のタイロッド31,31を有す
る操作機構30と、左右の車輪支持体15,15に各別
に連結する揺動リンク41,41を有する連動機構40
とを備える操向操作機構Sによって左右前輪1,1を操
向操作して車体の操向操作を行うものであり、詳しくは
次の如く構成してある。The wheel drive case 10 is provided with a base drive case 13 having the front and rear connecting shafts 11 and 12 at an intermediate portion.
An intermediate drive case part forming a pair of left and right intermediate supports 14 respectively connected to both ends of the base end drive case part 13; and a wheel support 15 connected to the left intermediate support 14
And the right intermediate support 14
The steering device is constituted by five cases including a front end drive case forming a wheel support 15 connected to the steering wheel. The steering device comprises left and right intermediate supports 14, 1
4, an operating mechanism 30 having a pair of tie rods 31, 31 connected separately to each other, and an interlocking mechanism 40 having swing links 41, 41 respectively connected to the left and right wheel supports 15, 15.
The left and right front wheels 1 and 1 are steered by a steering operation mechanism S having the following. The steering operation of the vehicle body is performed, and is configured in detail as follows.
【0034】前記基端駆動ケース部13の両端部に、車
体の車輪支持部16を構成する継手部材を備えさせてあ
る。左右の中間駆動ケース部それぞれの基端部14a
は、基端駆動ケース部13の前記継手部材の凹型の球面
継手部16aに摺動自在に内嵌する凸型の球面継手部1
4bを備えていて、前記継手部材に回動自在に連結して
いる。これにより、左側の中間支持体14は、車体左側
の車輪支持部16に車体上下向きの第1操向軸芯P1の
まわりで揺動自在に支持されており、右側の中間支持体
14は、車体右側の車輪支持部16に車体上下向きの第
1操向軸芯P1のまわりで揺動自在に支持されている。
左右の先端駆動ケース部それぞれの基端部は、中間駆動
ケース部の遊端部の上側支持部14cと下側支持部14
dとにわたって回動自在に連結している。これにより、
左側の車輪支持体15は、左側の中間支持体14の遊端
側に車体上下向きの第2操向軸芯P2まわりで揺動自在
に支持されているとともに遊端側で左前輪1を車軸芯ま
わりで回動自在に支持しており、右側の車輪支持体15
は、右側の中間支持体14の遊端側に車体上下向きの第
2操向軸芯P2まわりで揺動自在に支持されているとと
もに遊端側で右前輪1を車軸芯まわりで回動自在に支持
している。[0034] At both ends of the base drive case 13, joint members constituting a wheel support 16 of the vehicle body are provided. Base end 14a of each of left and right intermediate drive case parts
Is a convex spherical joint 1 slidably fitted in the concave spherical joint 16a of the joint member of the base end drive case 13.
4b, and is rotatably connected to the joint member. As a result, the left intermediate support 14 is supported by the wheel support 16 on the left side of the vehicle body so as to be swingable around the first steering axis P1 in the vertical direction of the vehicle body, and the right intermediate support 14 is The vehicle is supported by a wheel support portion 16 on the right side of the vehicle body so as to be swingable about a first steering axis P1 that is vertically directed to the vehicle body.
The base ends of the left and right distal drive case portions are respectively connected to the upper support portion 14c and the lower support portion 14 of the free end portion of the intermediate drive case portion.
and d. This allows
The left wheel support 15 is supported on the free end side of the left intermediate support 14 so as to be swingable around a second steering axis P2 that is vertically directed to the vehicle body, and the left front wheel 1 is axle-mounted at the free end side. The right wheel support 15 is rotatably supported around the center.
Is supported on the free end side of the right intermediate support member 14 so as to be swingable about a second steering axis P2 that is vertically directed to the vehicle body, and the right front wheel 1 is freely rotatable around the axle center on the free end side. I support it.
【0035】つまり、左前輪1においても右前輪1にお
いても、中間支持体14を第1操向軸芯P1のまわりで
車輪支持部16に対して車体前後方向に揺動操作し、車
輪支持体15を第2操向軸芯P2まわりで中間支持体1
4に対して車体前後方向に揺動操作することにより、車
輪1の車体に対する取り付け向きが直進向きになった
り、直進向きよりも左や右側に向く横向きになる。That is, in both the left front wheel 1 and the right front wheel 1, the intermediate support 14 is swung about the first steering axis P1 with respect to the wheel support 16 in the front-rear direction of the vehicle body. 15 around the second steering axis P2 to the intermediate support 1
By swinging the vehicle wheel 4 in the vehicle front-rear direction, the mounting direction of the wheel 1 with respect to the vehicle body becomes a straight-ahead direction, or a lateral direction that is more leftward or rightward than the straight-ahead direction.
【0036】前記操作機構30は、前記左右の中間支持
体14から延出しているナックルアーム14eに一端側
が各別に連結している前記タイロッド31と、この一対
のタイロッド31,31それぞれの他端側が遊端側に回
動自在に連結しているピットマンアーム32を軸芯32
aまわりで揺動操作自在に備えているとともに前記ステ
アリングハンドル5によって操作される油圧式のパワー
ステアリング装置34とによって構成してある。すなわ
ち、操作機構30は、左右の中間支持体14、14それ
ぞれのナックルアーム14eをステアリングハンドル5
に連係させることにより、左右の中間支持体14をステ
アリングハンドル5にこれの回動操作によって第1操向
軸芯P1のまわりで揺動操作できるように連係させてい
る。The operating mechanism 30 includes a tie rod 31 whose one end is separately connected to a knuckle arm 14 e extending from the left and right intermediate supports 14, and the other end of each of the pair of tie rods 31, 31. The pitman arm 32 rotatably connected to the free end side
and a hydraulic power steering device 34 which is provided so as to be swingable around a and is operated by the steering handle 5. That is, the operating mechanism 30 connects the knuckle arms 14 e of the left and right intermediate supports 14, 14 to the steering handle 5.
The left and right intermediate supports 14 are linked to the steering handle 5 such that the left and right intermediate supports 14 can be pivotally operated around the first steering axis P1 by the turning operation thereof.
【0037】前記連動機構40は、左側の車輪支持体1
5からこれを第2操向軸芯P2まわりで揺動操作するよ
うに延出している操作アーム部15aに一端側が回動自
在に連結している前記揺動リンク41を備える左側連動
機構部と、右側の車輪支持体15からこれを第2操向軸
芯P2まわりで揺動操作するように延出している操作ア
ーム部15aに一端側が回動自在に連結している前記揺
動リンク41を備える右側連動機構部とによって構成し
てある。左側連動機構部と右側連動機構部のいずれも
は、車輪支持体15の前記操作アーム部15aと、車体
の前記車輪支持部16が備えるアーム部16bと、前記
両アーム部15a,16bにわたって取り付けた前記揺
動リンク41とで成るリンク機構に構成するとともに、
中間支持体14が揺動操作されると、この操作力によ
り、車輪支持体15を中間支持体14の揺動に連動させ
て中間支持体14の揺動方向と同方向に揺動操作するよ
うに構成してある。これにより、連動機構40は、左右
の車輪支持体15,15を操作機構30によって左右の
中間支持体14,14と連動させて揺動操作されるよう
に操作機構30に連動させている。The interlocking mechanism 40 includes the left wheel support 1
5, a left-side interlocking mechanism including the swing link 41 having one end rotatably connected to an operation arm 15a extending so as to swing around the second steering axis P2. The swing link 41, one end of which is rotatably connected to an operation arm 15a extending from the right wheel support 15 so as to swing it around the second steering axis P2. And a right-side interlocking mechanism provided. Both the left and right interlocking mechanisms are mounted over the operation arm 15a of the wheel support 15, the arm 16b of the wheel support 16 of the vehicle body, and the two arms 15a, 16b. A link mechanism comprising the swing link 41 and
When the intermediate support 14 is rocked, the operating force causes the wheel support 15 to swing in the same direction as the rocking direction of the intermediate support 14 in conjunction with the rocking of the intermediate support 14. It is configured in. Accordingly, the interlocking mechanism 40 is interlocked with the operation mechanism 30 so that the left and right wheel supports 15 are swingably operated by the operation mechanism 30 in conjunction with the left and right intermediate supports 14.
【0038】これにより、操向操作機構Sは、左右側そ
れぞれの中間支持体14と車輪支持体15のうちの中間
支持体14を操作機構30によってステアリングハンド
ル5に連係させるとともに、左側の車輪支持体15を左
側の中間支持体14に、右側の車輪支持体15を右側の
中間支持体14にそれぞれ連動機構40によって連動さ
せて、ステアリングハンドル5の回動操作による左右前
輪1,1の操向操作を可能にしている。Thus, the steering operation mechanism S causes the intermediate support 14 of the left and right intermediate supports 14 and the intermediate support 14 of the wheel supports 15 to be linked to the steering handle 5 by the operation mechanism 30 and to the left wheel support. The body 15 is interlocked with the left intermediate support 14 and the right wheel support 15 is interlocked with the right intermediate support 14 by an interlocking mechanism 40, and the left and right front wheels 1, 1 are steered by turning the steering handle 5. Operation is enabled.
【0039】したがって、車体の操向操作を行うに当た
り、ステアリングハンドル5を回動操作すると、その操
作力と操向操作機構Sの作用とのために、左右の中間支
持体14が第1操向軸芯P1まわりで車体に対して前後
方向に揺動するとともに左右の車輪支持体15が第2操
向軸芯P2まわりで中間支持体14に対して車体前後方
向に揺動し、左右前輪1,1の車体に対する取り付け向
きがステアリングハンドル5の操作位置に対応する取り
付け向きになる。Therefore, when the steering handle 5 is turned to perform the steering operation of the vehicle body, the left and right intermediate supports 14 are moved in the first steering direction due to the operating force and the operation of the steering operation mechanism S. The left and right wheel supports 15 swing about the axis P1 in the front-rear direction with respect to the vehicle body, and the left and right wheel supports 15 swing about the second steering axis P2 with respect to the intermediate support 14 in the front-rear direction of the vehicle body. , 1 with respect to the vehicle body corresponds to the operating position of the steering handle 5.
【0040】すなわち、ステアリングハンドル5を回動
操作して直進位置に操作すると、左右の中間支持体1
4,14が、図5に明示する如く中間支持体14の上端
側の横向き部分における軸芯14fが基端駆動ケース部
13の軸芯13aに対して約15度の傾斜角度Aで車体
前方向きに傾斜する連結姿勢になり、左右の車輪支持体
15,15が、図6(イ)に示す如く車軸1aが車体横
向きになる連結姿勢になり、左右前輪1,1が車体に対
して直進向きになる。このとき、中間支持体14が車輪
支持部16に対してやや前向きになることにより、左右
それぞれの第2操向軸芯P2が第1操向軸芯P1よりも
やや車体前方側に位置する。That is, when the steering handle 5 is turned to the straight running position, the left and right intermediate supports 1 are moved.
5, the shaft center 14f in the horizontal portion on the upper end side of the intermediate support body 14 is directed toward the front of the vehicle body at an inclination angle A of about 15 degrees with respect to the shaft center 13a of the base end drive case portion 13, as clearly shown in FIG. 6A, the left and right wheel supports 15, 15 are in a connected posture in which the axle 1a is in the lateral direction of the vehicle body as shown in FIG. become. At this time, since the intermediate support 14 is slightly forward facing the wheel support 16, the left and right second steering axes P2 are located slightly forward of the first steering axis P1 with respect to the vehicle body.
【0041】ステアリングハンドル5を直進位置から左
又は右側に回動操作すると、図6(ロ)に示す如く左右
の中間支持体14,14のうちの旋回内側に位置する方
の中間支持体14が車輪支持部16に対して、車輪支持
体15が中間支持体14に対してそれぞれ直進走行のと
きよりも車体後方側に揺動し、旋回外側に位置する方の
中間支持体14が車輪支持部16に対して、車輪支持体
15が中間支持体14に対してそれぞれ直進走行のとき
よりも車体前方側に揺動し、左右前輪1、1が車体に対
してステアリングハンドル5の操作方向に等しい左向き
又は右向きの横向きになる。このとき、ステアリングハ
ンドル5の操作角度を大にするほど、左右前輪1、1の
直進向きからの切れ角が大になり、旋回内側に位置する
前輪1の直進向きからの最大切れ角が約90度になり、
旋回外側に位置する前輪1の直進向きからの最大切れ角
が約75度になる。When the steering handle 5 is rotated left or right from the straight traveling position, as shown in FIG. 6B, the left or right intermediate support 14, which is located on the inner side of the turn, is turned. The wheel support 15 swings toward the rear side of the vehicle body relative to the wheel support 16 with respect to the intermediate support 14 when the vehicle is traveling straight, and the intermediate support 14 located on the outer side of the turning is the wheel support. 16, the wheel support 15 swings forward relative to the intermediate support 14 compared to when the vehicle is traveling straight, and the left and right front wheels 1, 1 are equal to the operating direction of the steering handle 5 with respect to the vehicle body. It can be left or right sideways. At this time, as the operation angle of the steering wheel 5 increases, the turning angle of the left and right front wheels 1 and 1 from the straight running direction increases, and the maximum turning angle of the front wheel 1 located inside the turning from the straight running direction is about 90. Once again
The maximum turning angle of the front wheel 1 located outside the turning from the straight running direction is about 75 degrees.
【0042】図3〜図5に示すように、前記車輪駆動ケ
ース10の前記後側の連結軸12の内部に、前記軸芯X
と同芯状に配置した入力軸50を設けるとともに、この
入力軸50の回動力を左右前輪1,1に伝達する車輪駆
動機構51を車輪駆動ケース10の内部に設けてある。
前記入力軸50は、前記ミッションケース7から前方に
延出する回転軸7aに連結することにより、ミッション
ケース7の内部に位置する走行用ミッション(図示せ
ず)から前輪用の回転動力を導入するように構成してあ
る。As shown in FIGS. 3 to 5, the shaft center X is provided inside the rear connecting shaft 12 of the wheel drive case 10.
An input shaft 50 is provided concentrically with the input shaft 50, and a wheel drive mechanism 51 for transmitting the rotational power of the input shaft 50 to the left and right front wheels 1, 1 is provided inside the wheel drive case 10.
The input shaft 50 is connected to a rotating shaft 7 a extending forward from the transmission case 7, thereby introducing rotational power for front wheels from a traveling mission (not shown) located inside the transmission case 7. It is configured as follows.
【0043】前記車輪駆動機構51のうちの左前輪1の
ための駆動機構部も、右前輪1のための駆動機構部も、
車輪駆動ケース10のうちの前記基端駆動ケース部13
の内部に設けた伝動筒軸52、分配伝動軸53、前輪用
クラッチ54、伝動軸55のそれぞれと、前記中間支持
体14を構成している中間駆動ケース部の内部に設けた
入力側の横向き伝動軸56、出力側の上下向き伝動軸5
7のそれぞれと、前記車輪支持体15を構成している先
端駆動ケース部の内部に設けた車軸駆動ギヤ58とによ
って構成してある。The drive mechanism for the left front wheel 1 and the drive mechanism for the right front wheel 1 of the wheel drive mechanism 51 are:
The base drive case portion 13 of the wheel drive case 10
, A transmission cylinder shaft 53, a distribution transmission shaft 53, a front wheel clutch 54, and a transmission shaft 55, and an input-side horizontal direction provided inside an intermediate drive case portion forming the intermediate support 14. Transmission shaft 56, output-side vertical transmission shaft 5
7 and an axle drive gear 58 provided inside a front end drive case part constituting the wheel support 15.
【0044】前記伝動筒軸52は、これの一端側にスプ
ライン係合によって一体回動するようにして備えさせた
ベベルギヤ52aと、前記入力軸50の基端駆動ケース
部13の内部に位置する部分に備えてあるベベルギヤ部
50aとの噛み合いによって入力軸50に連動してい
る。分配伝動軸53は、伝動筒軸52に内嵌するととも
にスプライン係合していることによって伝動筒軸52と
一体回動する。分配伝動軸53の端部が前輪用クラッチ
54の入力筒軸54aに内嵌しているとともにスプライ
ン係合によって一体回動するように連結し、前輪用クラ
ッチ54の出力体54bが前記伝動軸55の端部に外嵌
するとともにスプライン係合によって一体回動するよう
に連結していることにより、分配伝動軸53の回動力が
前輪用クラッチ54を介して伝動軸55に伝達する。こ
の伝動軸55の他端側は、中間駆動ケース部の前記入力
側の横向き伝動軸56の端部に備えさせた自在継手59
によって横向き伝動軸56に一体回動するように連結し
ている。中間駆動ケース部の前記横向き伝動軸56は、
これの端部に外嵌するとともにスプライン係合によって
一体回動自在に連結するようにして備えさせたベベルギ
ヤ56aと、前記上下向き伝動軸57の上端側に外嵌す
るとともにスプライン係合によって一体回動自在に連結
するようにして備えさせたベベルギヤ57aとの噛み合
いによって、上下向き伝動軸57に連動している。この
上下向き伝動軸57の下端側に外嵌するとともにスプラ
イン係合によって一体回動するようにして備えてあるベ
ベルギヤ57bが前記車軸駆動ギヤ58に噛み合ってい
る。前記左右の自在継手59は、前記第1操向軸芯P1
と同一の軸芯まわりで屈曲するボール式の自在継手に構
成してある。The transmission cylinder shaft 52 has a bevel gear 52a provided at one end of the transmission cylinder shaft 52 so as to rotate integrally by spline engagement, and a portion located inside the base end drive case portion 13 of the input shaft 50. The gear is interlocked with the input shaft 50 by meshing with the bevel gear portion 50a provided for the motor. The distribution transmission shaft 53 is internally fitted to the transmission cylinder shaft 52 and is spline-engaged to rotate integrally with the transmission cylinder shaft 52. The end of the distribution transmission shaft 53 is fitted inside the input cylinder shaft 54a of the front wheel clutch 54 and connected so as to rotate integrally by spline engagement, and the output body 54b of the front wheel clutch 54 is connected to the transmission shaft 55. Of the distribution transmission shaft 53 is transmitted to the transmission shaft 55 via the front wheel clutch 54 by being externally fitted to the end of the transmission shaft 55 and connected so as to rotate integrally by spline engagement. The other end of the transmission shaft 55 is connected to a universal joint 59 provided at an end of the lateral transmission shaft 56 on the input side of the intermediate drive case.
Thus, it is connected to the lateral transmission shaft 56 so as to rotate integrally. The lateral transmission shaft 56 of the intermediate drive case portion is
A bevel gear 56a which is externally fitted to the end of the shaft and which is integrally rotatably connected by spline engagement, and which is externally fitted to the upper end of the vertical transmission shaft 57 and integrally rotated by spline engagement. By meshing with a bevel gear 57a provided so as to be movably connected, it is interlocked with the vertical transmission shaft 57. A bevel gear 57b which is fitted to the lower end of the vertical transmission shaft 57 and is integrally rotated by spline engagement is meshed with the axle drive gear 58. The left and right universal joints 59 are connected to the first steering axis P1.
And a ball-type universal joint that bends around the same axis.
【0045】これにより、車輪駆動機構51は、中間支
持体14の車輪支持部16に対する第1操向軸芯P1ま
わりでの揺動を自在継手59によって許容しながら、車
輪支持体15の中間支持体14に対する第2操向軸芯P
2まわりでの揺動をベベルギヤ56a,57aによって
許容しながら入力軸50の回動力を左右前輪1、1に伝
達する。したがって、左右前輪1,1は駆動可能な車輪
に成っている。Thus, the wheel drive mechanism 51 allows the universal joint 59 to allow the intermediate support 14 to swing about the first steering axis P1 with respect to the wheel support 16, while supporting the intermediate support 14 with the intermediate support 14. Second steering axis P for body 14
The rotation of the input shaft 50 is transmitted to the left and right front wheels 1 and 1 while allowing the swinging motion around the second 2 by the bevel gears 56a and 57a. Therefore, the left and right front wheels 1 and 1 are drivable wheels.
【0046】前記ミッションケース7の内部に位置する
走行用ミッション(図示せず)に、等速側と増速側とに
切り換え自在な前輪変速装置60を設けてある。この前
輪変速装置60は、等速側に切り換えると、左右前輪
1,1の平均周速度が左右後輪2,2の平均周速度にほ
ぼ等しくなる状態で左右前輪1,1を駆動し、増速側に
切り換えると、左右前輪1,1の平均周速度が左右後輪
2,2の平均周速度より約2倍の高速になる状態で左右
前輪1,1を駆動する。これにより、左右前輪1,1を
左向きは右向きに操向操作するとともにその切れ角を大
にして小旋回半径で旋回走行する際、前輪1の操向角検
出に基づいて自動作動する変速速制御手段によって前輪
変速装置60を増速側に自動的に切り換え操作させると
か、人為操作によって前輪変速装置60を増速側に切り
換えて左右前輪1,1を増速駆動させることにより、よ
り一層小旋回半径で旋回走行できる。A traveling transmission (not shown) located inside the transmission case 7 is provided with a front wheel transmission 60 that can be switched between a constant speed side and a speed increasing side. When switched to the constant speed side, the front wheel transmission 60 drives the left and right front wheels 1, 1 in a state where the average peripheral speed of the left and right front wheels 1, 1 is substantially equal to the average peripheral speed of the left and right rear wheels 2, 2. When switching to the high speed side, the left and right front wheels 1, 1 are driven in a state where the average peripheral speed of the left and right front wheels 1, 1 is about twice as high as the average peripheral speed of the left and right rear wheels 2, 2. Thus, when the left and right front wheels 1 and 1 are steered to the left and to the right, and the turning angle is increased and the vehicle is turned with a small turning radius, the shift speed control automatically operated based on the detection of the steering angle of the front wheels 1. By turning the front wheel transmission 60 automatically to the speed increasing side by means or by manually switching the front wheel transmission 60 to the speed increasing side to drive the left and right front wheels 1 and 1 to perform further small turning. You can make a turn with a radius.
【0047】〔別実施形態〕図7は、別の実施形態を有
する操向装置及び車輪駆動機構51を示し、この操向装
置においては、基端駆動ケース部13の両端部に、車体
の車輪支持部16を構成するケース部を備えさせてあ
る。左右の中間支持体14を構成する中間駆動ケース部
それぞれの基端部14aを、基端駆動ケース部13の上
支持部13bと、中支持部13cと、下支持部13dと
にわたって車体上下向きの第1操向軸芯P1のまわりで
回動するように連結してある。[Other Embodiment] FIG. 7 shows a steering device and a wheel drive mechanism 51 according to another embodiment. A case part constituting the support part 16 is provided. The base end portion 14a of each of the intermediate drive case portions forming the left and right intermediate support members 14 is vertically oriented across the upper support portion 13b, the middle support portion 13c, and the lower support portion 13d of the base drive case portion 13. The first steering axis P1 is connected so as to rotate around the first steering axis P1.
【0048】操向操作機構Sの操作機構30と連動機構
40のうちの連動機構40を、図7及び図8に示す如く
車輪支持体14を構成する先端駆動ケースの上端部に設
けた設けたギヤ42と、前記車輪支持部16の上端部に
設けたギヤ43とで成るギヤ式に構成してある。支持体
側のギヤ42は、中間支持体14に対して第2操向軸芯
P2のまわりで車輪支持体15と共に回動するように配
置するとともに車輪支持体15に回動不能に固定してあ
る。車体側のギヤ43は、車輪支持部16に回動不能に
固定してある。中間支持体14が前記操作機構30によ
って第1操向軸芯P1のまわりで車輪支持部16に対し
て車体前後方向に揺動操作されると、両ギヤ42,43
が互いに噛み合っていることにより、支持体側のギヤ4
2が車体側のギヤ43に沿って第1操向軸芯P1のまわ
りで公転しながら自転し、この自転のために、車輪支持
体15が第2操向軸芯P2のまわりで中間支持体14に
対して車体前後方向に揺動する。これにより、連動機構
40は、中間支持体14が揺動操作されると、この操作
力により、車輪支持体15を中間支持体14の揺動に連
動させて中間支持体14の揺動方向と同方向に揺動操作
する。中間支持体14が揺動する角度と、車輪支持体1
5が揺動する角度との比が、中間支持体14の揺動位置
が変化しても両ギヤ42,43の連動比によって決まる
一定の比になる状態で揺動操作する。The interlocking mechanism 40 of the operation mechanism 30 and the interlocking mechanism 40 of the steering operation mechanism S is provided at the upper end of the tip end drive case constituting the wheel support 14 as shown in FIGS. The gear type is constituted by a gear 42 and a gear 43 provided at the upper end of the wheel support 16. The gear 42 on the support side is arranged so as to rotate with the wheel support 15 around the second steering axis P2 with respect to the intermediate support 14 and is fixed to the wheel support 15 so as not to rotate. . The gear 43 on the vehicle body side is fixed to the wheel support 16 so as not to rotate. When the intermediate support 14 is swung by the operating mechanism 30 around the first steering axis P1 with respect to the wheel support 16 in the vehicle longitudinal direction, the two gears 42, 43
Are meshed with each other, so that the gear 4 on the support body side
2 revolves around the first steering axis P1 along the gear 43 on the vehicle body side, and due to this rotation, the wheel support 15 is rotated around the second steering axis P2 by the intermediate support. It swings in the longitudinal direction of the vehicle body with respect to 14. Accordingly, when the intermediate support 14 is rocked, the interlocking mechanism 40 causes the wheel support 15 to interlock with the rocking of the intermediate support 14 by this operating force, thereby changing the rocking direction of the intermediate support 14. Swing in the same direction. The angle at which the intermediate support 14 swings and the wheel support 1
The swing operation is performed in a state where the ratio of the swing angle of the gear 5 to the swing angle of the intermediate support 14 changes to a constant ratio determined by the interlocking ratio of the two gears 42 and 43 even when the swing position of the intermediate support 14 changes.
【0049】車輪駆動機構51のうちの左前輪1のため
の駆動機構部も、右前輪1のための駆動機構部も、前記
入力軸50のベベルギヤ部50aに入力ギヤが噛み合う
差動機構と、この差動機構の出力ギヤに一端側が連動し
ている伝動軸62と、この伝動軸62の他端側にベベル
ギヤ機構63によって下端側が連動している車体上下向
きの伝動軸64と、この伝動軸64の上端側にベベルギ
ヤ機構65によって一端側が連動している横向きの伝動
軸66と、この伝動軸66の他端側にベベルギヤ機構6
7によって上端側が連動している車体上下向きの伝動軸
68と、この伝動軸68の下端側に一体回動自在に備え
てあるベベルギヤ69に噛み合う状態で車軸1aに一体
回動自在に連結している車軸駆動ギヤ58とのそれぞれ
によって構成してある。The drive mechanism for the left front wheel 1 and the drive mechanism for the right front wheel 1 of the wheel drive mechanism 51 include a differential mechanism in which the input gear meshes with the bevel gear section 50a of the input shaft 50; A transmission shaft 62 whose one end is interlocked with the output gear of the differential mechanism; a vehicle-body vertical transmission shaft 64 whose lower end is interlocked with the other end of the transmission shaft 62 by a bevel gear mechanism 63; A lateral transmission shaft 66 whose one end is interlocked by a bevel gear mechanism 65 on the upper end side of the transmission shaft 64, and a bevel gear mechanism 6 on the other end side of the transmission shaft 66.
The transmission shaft 68 is vertically connected to the axle 1a in a state in which the transmission shaft 68 is vertically engaged with the transmission shaft 68 whose upper end is interlocked with the bevel gear 69 provided on the lower end of the transmission shaft 68 so as to be integrally rotatable. And an axle drive gear 58 that is provided.
【0050】操向操作機構Sの操作機構30と連動機構
40のうちの操作機構30としては、上記実施形態に示
した如く、左右の中間支持体14の方をステアリングハ
ンドル5に連係させるよう構成したもの他、左右の車輪
支持体15の方をステアリングハンドル5に連係させる
よう構成したものを採用して実施してもよい。この場
合、連動機構40としては、車輪支持体15が揺動する
に連動して中間支持体14が揺動するように構成するも
のを採用することになる。The operation mechanism 30 of the operation mechanism 30 of the steering operation mechanism S and the interlocking mechanism 40 is configured such that the left and right intermediate supports 14 are linked to the steering handle 5 as shown in the above embodiment. In addition to the above, a configuration in which the left and right wheel supports 15 are linked to the steering handle 5 may be employed. In this case, as the interlocking mechanism 40, a mechanism configured to swing the intermediate support 14 in conjunction with the swing of the wheel support 15 is adopted.
【0051】また、操向操作機構Sの操作機構30とし
ては、左右の中間支持体14と車輪支持体15との一方
を油圧式パワーステアリング装置34によってステアリ
ングハンドル5に連係させるもの他、機械式のステアリ
ング装置や、電動式のパワーステアリング装置によって
連係させる手段を採用して実施してもよい。As the operation mechanism 30 of the steering operation mechanism S, one of the left and right intermediate supports 14 and the wheel support 15 is linked to the steering handle 5 by a hydraulic power steering device 34, and the other is a mechanical type. The present invention may be implemented by adopting a steering device of the type described above or a unit linked by an electric power steering device.
【0052】本発明は、農用トラクターの他、芝刈り機
など各種の作業車にも適用できる。The present invention can be applied to various work vehicles such as lawn mowers in addition to agricultural tractors.
【図1】農用トラクタ全体の側面図FIG. 1 is a side view of an entire agricultural tractor.
【図2】前輪取り付け構造の平面図FIG. 2 is a plan view of a front wheel mounting structure.
【図3】前輪駆動ケース支持部の断面図FIG. 3 is a sectional view of a front wheel drive case supporting portion.
【図4】中間支持体及び車輪支持体の支持部の縦断面図FIG. 4 is a longitudinal sectional view of a support portion of an intermediate support and a wheel support.
【図5】中間支持体の支持部の横断面図FIG. 5 is a cross-sectional view of a support portion of the intermediate support.
【図6】前輪操向状態の説明図FIG. 6 is an explanatory diagram of a front wheel steering state.
【図7】別の実施形態を備える中間支持体及び車輪支持
体の縦断面図FIG. 7 is a longitudinal sectional view of an intermediate support and a wheel support according to another embodiment.
【図8】ギヤ式連動機構の平面図FIG. 8 is a plan view of a gear-type interlocking mechanism.
1 車輪 5 ステアリングハンドル 14 中間支持体 15 車輪支持体 16 車輪支持部 30 操作機構 40 連動機構 41 揺動リンク 42,43 ギヤ 55,56 伝動軸 59 自在継手 P1 第1操向軸芯 P2 第2操向軸芯 S 操向操作機構 Reference Signs List 1 wheel 5 steering handle 14 intermediate support 15 wheel support 16 wheel support 30 operating mechanism 40 interlocking mechanism 41 swing link 42, 43 gear 55, 56 transmission shaft 59 universal joint P1 first steering axis P2 second operation Direction axis S Steering operation mechanism
Claims (6)
下向きの第1操向軸芯まわりで揺動自在に支持されてい
る左右一対の中間支持体と、前記左側の中間支持体の遊
端側に車体上下向きの第2操向軸芯まわりで揺動自在に
支持されているとともに左車輪を車軸芯まわりで回動自
在に支持している車輪支持体と、前記右側の中間支持体
の遊端側に車体上下向きの第2操向軸芯まわりで揺動自
在に支持されているとともに右車輪を車軸芯まわりで回
動自在に支持している車輪支持体とを備え、 前記左右の中間支持体を前記第1操向軸芯まわりで揺動
操作するとともに前記左右の車輪支持体を前記第2操向
軸芯まわりで揺動操作して左右車輪を操向操作する操向
操作機構を備えてある作業車の操向装置。1. A pair of left and right intermediate supports respectively supported on left and right wheel support portions of a vehicle body so as to be swingable around a first steering axis centering vertically on the vehicle body, and a pair of left and right intermediate support members. A wheel support that is supported at the free end side so as to be swingable about a second steering axis centering vertically on the vehicle body and that supports the left wheel rotatably around the axle axis; A wheel supporter which is supported on the free end side of the body so as to be swingable around a second steering axis centering vertically on the vehicle body and which supports the right wheel rotatably around the axle axis; Steering for swinging left and right intermediate supports around the first steering axis and swinging the left and right wheel supports around the second steering axis to steer left and right wheels. A steering device for a work vehicle equipped with an operation mechanism.
記第2操向軸芯が前記第1操向軸芯よりも車体前後方向
に位置ずれしている請求項1記載の作業車の操向装置。2. The operation of a work vehicle according to claim 1, wherein the second steering axis is displaced in the vehicle longitudinal direction from the first steering axis when the left and right wheels are in the straight traveling direction. Equipment.
をステアリングハンドルに連係させている操作機構と、
前記車輪支持体と前記中間支持体の他方を前記操作機構
に連動させている連動機構とを、前記操向操作機構に備
えてある請求項1又は2記載の作業車の操向装置。3. An operating mechanism that links one of the wheel support and the intermediate support to a steering handle;
The steering device for a work vehicle according to claim 1 or 2, wherein the steering operation mechanism includes an interlocking mechanism that interlocks the other of the wheel support and the intermediate support with the operation mechanism.
中間支持体の他方と、前記車輪支持部とにわたって取り
付けた揺動リンクを備えるリンク式である請求項3記載
の作業車の操向装置。4. The steering of a work vehicle according to claim 3, wherein the interlocking mechanism is a link type including a swing link attached to the other of the wheel support and the intermediate support and the wheel support. apparatus.
中間支持体の他方が一体回動自在に備えるギヤと、この
ギヤに噛み合う状態で前記車輪支持部に固定されている
ギヤとを備えるギヤ式である請求項3記載の作業車の操
向装置。5. The interlocking mechanism includes a gear provided with the other of the wheel support and the intermediate support so as to be rotatable integrally with the wheel support, and a gear fixed to the wheel support in a state of meshing with the gear. The steering device for a working vehicle according to claim 3, wherein the steering device is a gear type.
車輪支持体を、左右車輪に駆動力を伝達する車輪駆動ケ
ースによって構成し、車輪支持部を構成する駆動ケース
部が備える伝動軸と、中間支持体を構成する駆動ケース
部が備える伝動軸とを連結するとともに前記第1操向軸
芯と同一の軸芯まわりで屈曲する自在継手を備えてある
請求項1〜5のいずれか1項に記載の作業車の操向装
置。6. The drive shaft, wherein the left and right wheel support portions, the intermediate support member, and the wheel support member are configured by a wheel drive case that transmits a driving force to the left and right wheels, and a transmission shaft provided in a drive case portion that configures the wheel support portion. 6. A universal joint which connects a transmission shaft provided in a drive case part constituting an intermediate support and is bent about the same axis as the first steering axis. The steering device for a working vehicle according to item 7.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP26574899A JP3594519B2 (en) | 1999-09-20 | 1999-09-20 | Work vehicle steering system |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP26574899A JP3594519B2 (en) | 1999-09-20 | 1999-09-20 | Work vehicle steering system |
Publications (2)
Publication Number | Publication Date |
---|---|
JP2001086803A true JP2001086803A (en) | 2001-04-03 |
JP3594519B2 JP3594519B2 (en) | 2004-12-02 |
Family
ID=17421465
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP26574899A Expired - Fee Related JP3594519B2 (en) | 1999-09-20 | 1999-09-20 | Work vehicle steering system |
Country Status (1)
Country | Link |
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JP (1) | JP3594519B2 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2003002212A (en) * | 2001-06-20 | 2003-01-08 | Yanmar Agricult Equip Co Ltd | Agricultural working machine |
GB2409441A (en) * | 2003-12-23 | 2005-06-29 | Agco Gmbh & Co | Suspension arrangement for proper steering angle for agricultural vehicles |
EP3263371A1 (en) | 2016-06-27 | 2018-01-03 | Kubota Corporation | Axle device |
-
1999
- 1999-09-20 JP JP26574899A patent/JP3594519B2/en not_active Expired - Fee Related
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2003002212A (en) * | 2001-06-20 | 2003-01-08 | Yanmar Agricult Equip Co Ltd | Agricultural working machine |
GB2409441A (en) * | 2003-12-23 | 2005-06-29 | Agco Gmbh & Co | Suspension arrangement for proper steering angle for agricultural vehicles |
EP3263371A1 (en) | 2016-06-27 | 2018-01-03 | Kubota Corporation | Axle device |
US10703409B2 (en) | 2016-06-27 | 2020-07-07 | Kubota Corporation | Work vehicle axle device |
Also Published As
Publication number | Publication date |
---|---|
JP3594519B2 (en) | 2004-12-02 |
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