JPH0310937A - Steering control wheel driving device of four-wheel drive automobile - Google Patents
Steering control wheel driving device of four-wheel drive automobileInfo
- Publication number
- JPH0310937A JPH0310937A JP14568789A JP14568789A JPH0310937A JP H0310937 A JPH0310937 A JP H0310937A JP 14568789 A JP14568789 A JP 14568789A JP 14568789 A JP14568789 A JP 14568789A JP H0310937 A JPH0310937 A JP H0310937A
- Authority
- JP
- Japan
- Prior art keywords
- turning
- wheel
- gear
- wheels
- front wheel
- 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.)
- Pending
Links
- 230000007246 mechanism Effects 0.000 claims description 4
- 230000004044 response Effects 0.000 claims description 2
- 230000002093 peripheral effect Effects 0.000 abstract description 5
- 238000013016 damping Methods 0.000 abstract 1
- 238000004513 sizing Methods 0.000 abstract 1
- 238000001514 detection method Methods 0.000 description 21
- 230000005540 biological transmission Effects 0.000 description 18
- 230000009467 reduction Effects 0.000 description 9
- 238000000605 extraction Methods 0.000 description 5
- 239000002689 soil Substances 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000001125 extrusion Methods 0.000 description 2
- 230000033001 locomotion Effects 0.000 description 2
- 238000007790 scraping Methods 0.000 description 2
- 210000001015 abdomen Anatomy 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000007788 roughening Methods 0.000 description 1
Landscapes
- Arrangement And Driving Of Transmission Devices (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、四輪駆動車輌の操向輪駆動装置に関するもの
である。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a steering wheel drive system for a four-wheel drive vehicle.
従来の技術
前輪（操向輪）と後輪（非操向輪）とを駆動する農用ト
ラクタ等の四輪駆動車輌は、牽引作業性能、不整地走行
性能、舵取り性能等の点で優れているが、旋回時におい
ては、前輪と後輪との旋回半径に差があるため、前輪が
後輪に押される状態となってサイドスリップを生じ、旋
回半径が大きくなるとともに旋回時間が長くなるという
欠点がある。さらに、前輪がサイドスリップすることに
より生ずる土押出し１や、後輪が周方向にスリップする
ことにより生ずる土掻き等によって、旋回跡地を荒すと
いう欠点がある。Conventional technology Four-wheel drive vehicles such as agricultural tractors that drive front wheels (steering wheels) and rear wheels (non-steering wheels) are superior in terms of towing performance, rough terrain driving performance, steering performance, etc. However, when turning, there is a difference in the turning radius between the front wheels and the rear wheels, so the front wheels are pushed by the rear wheels, causing side slip, which increases the turning radius and lengthens the turning time. There is. Furthermore, there is a drawback that the turning area becomes rough due to dirt extrusion 1 caused by the side slip of the front wheels and dirt scraping caused by the rear wheels slipping in the circumferential direction.
そこで、特開昭５３−１１９５３１号公報、又は、特公
昭６２−３５９２９号公報に記載されたように、旋回時
における前輪の周速度を後輪の周速度より速くし、前輪
が後輪により押されることによって生ずる前輪のサイド
スリップを防止するようにしたトラクタがある。Therefore, as described in Japanese Patent Application Laid-Open No. 53-119531 or Japanese Patent Publication No. 62-35929, the circumferential speed of the front wheels is made faster than the circumferential speed of the rear wheels during turning, so that the front wheels are pushed by the rear wheels. Some tractors are designed to prevent side slips of the front wheels that occur when the front wheels are rotated.
発明が解決しようとする課題
まず、特開昭５３−１１９５３１号公報に記載されたト
ラクタにおいては、第６図に示すように、旋回内側の前
輪をＡ、旋回外側の前輪をＢ、旋回内側の後輪をＣ１旋
回外側の後輪をＤ、ホイールベースをＱ、トレッドをｋ
、旋回中心Ｏから後輪Ｃまでの距離をｒ、旋回角度をθ
とすれば、旋回時における内側前輪Ａの旋回軌跡の長さ
Ｌｌ と外側前輪Ｂの旋回軌跡の長さＬ８ との和Ｔ
１ と、旋回時における内側後輪Ｃの旋回軌跡の長さ
り、と外側後輪りの旋回軌跡の長さＬ４ との和Ｔ２と
は、となる。そして、前輪Ａ、Ｂの旋回軌跡の長さと、
後輪Ｃ，Ｄの旋回軌跡の長さとの比ｉは、となる。そこ
で、旋回時にはこのような旋回軌跡の長さ比ｉに応じた
周速度で前輪Ａ、Ｂと後輪Ｃ１Ｄとを駆動させ、前輪Ａ
、Ｂが後輪Ｃ，Ｄに押されることにより生ずる前輪Ａ、
Ｂのサイドスリップを防止するようにしている。しかし
、旋回時における前輪Ａ、Ｂの実際の旋回軌跡は、土壌
条件等によって生ずるサイドスリップによりＬ、Ｌ、
となり、理論式上のし、＋Ｌｘ より大きくなる。この
ように、特開昭５３−１１９．５３１号公報に記載され
たトラクタにおいては、Ｌ。Problems to be Solved by the Invention First, in the tractor described in JP-A-53-119531, as shown in FIG. 6, the front wheel on the inside of the turn is A, the front wheel on the outside of the turn is B, and the front wheel on the inside of the turn Turn the rear wheel C1, set the outer rear wheel D, wheelbase Q, tread k
, the distance from the turning center O to the rear wheel C is r, and the turning angle is θ.
Then, the sum T of the length Ll of the turning trajectory of the inside front wheel A and the length L8 of the turning path of the outside front wheel B when turning.
1, the length of the turning trajectory of the inner rear wheel C during turning, and the length L4 of the turning trajectory of the outer rear wheel, the sum T2 is as follows. And the length of the turning trajectory of front wheels A and B,
The ratio i to the length of the turning trajectory of the rear wheels C and D is as follows. Therefore, when turning, the front wheels A, B and the rear wheel C1D are driven at a circumferential speed according to the length ratio i of the turning trajectory, and the front wheel A
, B is pushed by rear wheels C and D, resulting in front wheel A,
This is to prevent side slip of B. However, the actual turning trajectory of the front wheels A and B during a turn is caused by side slips caused by soil conditions, etc.
, which is based on the theoretical formula and is larger than +Lx. In this way, in the tractor described in Japanese Patent Application Laid-Open No. 53-119.531, the L.
Ｌ、′に示すような軌跡変化が考慮されておらず、従っ
て、旋回半径を十分に小さくすることができず、その分
旋回時間が長くなり、さらに、旋回外側へ向けての土押
出しにより旋回跡地を荒すという欠点がある。Changes in trajectory as shown in L and ′ are not taken into account, and therefore the turning radius cannot be made sufficiently small, which increases the turning time.Furthermore, the turning It has the disadvantage of ruining the site.
また、特公昭６２−３５９２９号公報に記載されたトラ
クタにおいては、旋回時における前輪と後輪との周速度
比を、前輪が後輪を引きするような値とし、前輪が後輪
により押されてサイドスリップすることを防止している
。しかし、前輪が後輪を引きするため、前輪が周方向に
スリップして土掻きを生じ、さらに、後輪が旋回内側へ
サイドスリップすることによって旋回跡地を荒らすとい
う欠点がある。Furthermore, in the tractor described in Japanese Patent Publication No. 62-35929, the circumferential speed ratio between the front wheels and the rear wheels during turning is set to such a value that the front wheels pull the rear wheels, and the front wheels are pushed by the rear wheels. This prevents side slips. However, since the front wheels pull the rear wheels, the front wheels slip in the circumferential direction, causing dirt, and furthermore, the rear wheels side-slip to the inside of the turn, making the turning area rougher.
課題を解決するための手段
低速側ギヤと高速側ギヤとを有するとともに操向輪操作
機構に応動して切り換えられる高低速切換装置を操向輪
駆動系に設け、直進時には前記低速側ギヤを介して操向
輪への駆動力伝達を行うとともに旋回時には前記高速側
ギヤを介して前記操向輪への駆動力伝達を行う四輪駆動
車輌において、旋回内側の非操向輪にこの非操向輪が回
転可能な範囲の抵抗を加える制動装置を設け、旋回時に
おける前記操向輪と前記非操向輪との旋回中心が略一致
するように前記操向輪と前記非操向輪との周速度比を設
定した。Means for Solving the Problems A steering wheel drive system is provided with a high/low speed switching device that has a low speed gear and a high speed gear and can be switched in response to a steering wheel operating mechanism, and when traveling straight, the steering wheel drive system is configured to switch between high and low speeds through the low speed gear when traveling straight. In a four-wheel drive vehicle that transmits driving force to the steered wheels via the high-speed gear when turning, the non-steerable wheels are connected to the non-steered wheels on the inside of the turn. A braking device is provided that applies resistance within a range that allows the wheels to rotate, and the steering wheel and the non-steering wheel are connected so that the turning centers of the steering wheel and the non-steering wheel substantially coincide with each other during turning. The peripheral speed ratio was set.
さらに、操向輪を最大操向角度の近傍に操向操作したと
きに高低速切換装置を低速側ギヤから高速側ギヤに切り
換えた。Further, when the steering wheels were steered to near the maximum steering angle, the high/low speed switching device was switched from the low speed gear to the high speed gear.
作用
四輪駆動車輌においては、差動装置より後方に最終減速
装置を設けていることが一般的であり、旋回時における
差動抵抗が最終減速装置の減速比に比例して増大し、旋
回内側の非操向輪に大きな駆動力を発生させる。そして
、この駆動力が旋回中の四輪駆動車輌を直進させようと
するために操向輪にサイドフォースが発生し、操向輪が
サイドスリップを生じて旋回半径が大きくなる。しかし
。In four-wheel drive vehicles, the final reduction gear is generally installed behind the differential, and the differential resistance during turns increases in proportion to the reduction ratio of the final reduction gear. generates large driving force to the non-steering wheels of the vehicle. Since this driving force tries to cause the turning four-wheel drive vehicle to go straight, a side force is generated on the steering wheel, causing side slip on the steering wheel and increasing the turning radius. but.
制動装置が旋回内側の非操向輪に抵抗を加えることによ
り、旋回内側の非操向輪に発生する駆動力が低減され、
従って、操向輪に発生するサイドフォースも低減される
。By applying resistance to the non-steering wheel on the inside of the turn by the braking device, the driving force generated on the non-steering wheel on the inside of the turn is reduced.
Therefore, the side force generated on the steering wheel is also reduced.
また、旋回時には、高低速切換装置が高速側ギヤ側に切
換えられ、操向輪と非操向輪との旋回中心が略一致する
周速度比で操向輪と非操向輪とが駆動される。そして、
操向輪と非操向輪との旋回中心が略一致することにより
、操向輪と非操向輪との周方向のスリップ及びサイドス
リップが防止され、四輪駆動車輌は小さな旋回半径でス
ムーズに旋回する。Also, when turning, the high-low speed switching device is switched to the high-speed gear side, and the steered wheels and non-steered wheels are driven at a circumferential speed ratio that makes the turning centers of the steered wheels and non-steered wheels approximately coincide. Ru. and,
Since the turning centers of the steered wheels and non-steered wheels almost coincide, circumferential slips and side slips between the steered wheels and non-steered wheels are prevented, and four-wheel drive vehicles can smoothly turn with a small turning radius. Turn around.
さらに、操向輪を最大操向角度の近傍に操向操作したと
きに高低速切換装置を低速側ギヤから高速側ギヤに切り
換えることにより、四輪駆動車輌を最も小さな旋回半径
で旋回させるような場合にのみ操向輪と非操向輪との旋
回中心が略一致する周速度比で操向輪と非操向輪とが駆
動され、四輪駆動車輌を大きな旋回半径で旋回させるよ
うな場合には、高低速切換装置は高速側ギヤに切換えら
れず、操向輪と非操向輪とは等しい周速度で駆動される
。Furthermore, when the steering wheels are steered to near the maximum steering angle, the high/low speed switching device is switched from a low speed gear to a high speed gear, so that the four-wheel drive vehicle can turn with the smallest turning radius. Only in cases where the steered wheels and non-steered wheels are driven at a circumferential speed ratio where the turning centers of the steered wheels and non-steered wheels substantially coincide, and the four-wheel drive vehicle is turned with a large turning radius. In this case, the high/low speed switching device does not switch to the high speed gear, and the steered wheels and non-steered wheels are driven at the same circumferential speed.
実施例
本発明の一実施例を第１図乃至第５図に基づいて説明す
る。まず、四輪駆動車輌であるトラクタ１の腹部には前
方から順にエンジン２、クラッチケース３、ミッション
ケース４、デフケース５が配設され、デフケース５の下
部には前輪動力取出ケース６が固定されている。前記ク
ラッチケース３内にはメインクラッチ７が収納され、前
記ミッションケース４内には前後進切換装置８と主変速
装置９と副変速装置ｌＯとが収納され、前記デフケース
５内にはクリープ装置１１と前輪動力取出装置１２と後
輪差動装置１３とＰＴＯ変速装置１４とが収納され、前
記前輪動力取出ケース６内には高低速切換装置である前
輪変速装置１５が収納されている。Embodiment An embodiment of the present invention will be explained based on FIGS. 1 to 5. First, an engine 2, a clutch case 3, a transmission case 4, and a differential case 5 are arranged in order from the front on the abdomen of a tractor 1, which is a four-wheel drive vehicle.A front wheel power extraction case 6 is fixed to the lower part of the differential case 5. There is. A main clutch 7 is housed in the clutch case 3, a forward/reverse switching device 8, a main transmission 9, and an auxiliary transmission 1O are housed in the transmission case 4, and a creep device 11 is housed in the differential case 5. A front wheel power extraction device 12, a rear wheel differential device 13, and a PTO transmission 14 are housed, and a front wheel transmission 15, which is a high-low speed switching device, is housed in the front wheel power extraction case 6.
また、前記デフケース５内にはドライブピニオン軸１６
が軸支されており、このドライブピニオン軸１６の一端
にはドライブピニオン１７が固定され、ドライブピニオ
ン軸１６の他端は前記クリープ装置１１に連結されてい
る。さらに、前記ドライブピニオン１７は前記後輪差動
装置１３のベベルギヤ１８と噛み合っており、後輪差動
装置１３には制動装置１９と最終減速装置２０とを介し
て非操向輪である後輪２１が連結されている。なお、前
記制動装置１９は、前記トラクタ１の旋回時において、
旋回内側となる前記後輪２１にこの後輪２１が回転可能
な範囲の抵抗を加えるものである。Further, a drive pinion shaft 16 is provided in the differential case 5.
A drive pinion 17 is fixed to one end of the drive pinion shaft 16, and the other end of the drive pinion shaft 16 is connected to the creep device 11. Furthermore, the drive pinion 17 is engaged with a bevel gear 18 of the rear wheel differential 13, and the rear wheel differential 13 is connected to the rear wheel, which is a non-steering wheel, via a braking device 19 and a final reduction gear 20. 21 are connected. Note that the braking device 19 is configured such that when the tractor 1 turns,
This applies resistance to the rear wheel 21, which is on the inside of the turn, within a range that allows the rear wheel 21 to rotate.
前記前輪動力取出ケース６内には前輪動力取出軸２２が
軸支され、この前輪動力取出軸２２にはギヤ２３と軸受
スリーブ２４とがスプライン嵌合されている。前記軸受
スリーブ２４には低速側ギヤ２５と高速側ギヤ２６とが
軸受２７〜２９を介して保持され、高速側ギヤ２６は電
磁クラッチ３０を介して前記前輪動力取出軸２２に連結
されている。一方、前記低速側ギヤ２５と前記軸受スリ
ーブ２４との間には、低速側ギヤ２５から前輪動力取出
軸２２へのみ駆動力を伝達するワンウェイクラッチ３１
が介装されている。また、前記低速側ギヤ２５にはクラ
ッチギヤ３２が一体的に形成され、このクラッチギヤ３
２に噛み合うことにより前記低速側ギヤ２５と前記ギヤ
２３とを連結するスライドギヤ３３が設けられている。A front wheel power take-off shaft 22 is pivotally supported within the front wheel power take-off case 6, and a gear 23 and a bearing sleeve 24 are spline-fitted to the front wheel power take-off shaft 22. A low speed gear 25 and a high speed gear 26 are held in the bearing sleeve 24 via bearings 27 to 29, and the high speed gear 26 is connected to the front wheel power take-off shaft 22 via an electromagnetic clutch 30. On the other hand, a one-way clutch 31 is provided between the low-speed gear 25 and the bearing sleeve 24, which transmits the driving force only from the low-speed gear 25 to the front wheel power take-off shaft 22.
is interposed. Further, a clutch gear 32 is integrally formed with the low speed side gear 25, and this clutch gear 3
A slide gear 33 is provided which connects the low-speed gear 25 and the gear 23 by meshing with the gear 23.
また、前記デフケース５内には前記前輪動力取出ケース
６から上方に突出した支持部３４によって支軸３５が保
持さｈ、この支軸３５゛には一対のギヤ３６．３７を有
する中間ギヤ３８が軸支され、さらに、支軸３５の端部
には前記スライドギヤ３３をスライドさせるシフター３
９が保持されている。なお、前記ギヤ３６は前記高速側
ギヤ２６と常時噛み合い、前記ギヤ３７は前記低速側ギ
ヤ２５と常時噛み合っている。また、前記ドライブピニ
オン軸１６には前輪動力取出ギヤ４０がスライド自在に
スプライン嵌合され、この前輪動力取出ギヤ４０は前記
ギヤ３７に選択的に噛み合っている。A support shaft 35 is held within the differential case 5 by a support portion 34 projecting upward from the front wheel power extraction case 6, and an intermediate gear 38 having a pair of gears 36 and 37 is mounted on the support shaft 35'. A shifter 3 is rotatably supported and further has a shifter 3 at the end of the support shaft 35 that slides the slide gear 33.
9 is retained. The gear 36 is always in mesh with the high-speed gear 26, and the gear 37 is always in mesh with the low-speed gear 25. Further, a front wheel power take-off gear 40 is slidably spline-fitted to the drive pinion shaft 16, and this front wheel power take-off gear 40 selectively meshes with the gear 37.
前記前輪動力取出軸２２は伝動軸カバー４１に被覆され
た前輪動力伝動軸４２の一端に連結され、前輪動力伝動
軸４２の他端は前輪差動装置４３に連結されている。さ
らに、前記前輪差動装置４３には操向減速装置４４を介
して操向輪である前輪４５が連結されている。ここで、
前記低速側ギヤ２５を介して前記前輪４５への駆動力伝
達が行われる場合には、前輪４５と後輪２１との周速度
が略等しくなるように設定されており、一方、前記高速
側ギヤ２６を介して前輪４５への駆動力伝達が行われる
場合は、前輪４５と後輪２１との旋回中心が略一致する
周速度比となるように前輪４５の周速度が上昇する。The front wheel power output shaft 22 is connected to one end of a front wheel power transmission shaft 42 covered by a transmission shaft cover 41, and the other end of the front wheel power transmission shaft 42 is connected to a front wheel differential device 43. Further, a front wheel 45, which is a steering wheel, is connected to the front wheel differential device 43 via a steering speed reduction device 44. here,
When the driving force is transmitted to the front wheels 45 via the low-speed gear 25, the circumferential speeds of the front wheels 45 and the rear wheels 21 are set to be approximately equal, while the high-speed gear When the driving force is transmitted to the front wheels 45 via the front wheels 26, the circumferential speed of the front wheels 45 increases so that the circumferential speed ratio of the turning centers of the front wheels 45 and the rear wheels 21 substantially coincide with each other.
前記電磁クラッチ３０は、第３図に示すように、前輪４
５が最大操向角度の近傍まで操向操作されたことを検出
して閉路する旋回検出スイッチ４６と、前記副変速装置
１０が高速変速状態以外の変速位置に操作されていると
きに閉路する副変速検出スイッチ４７と、前記副変速検
出スイッチ４７に対して並列に配設されるとともに前記
クリープ装置１１がクリープ状態時に閉路するクリープ
検出スイッチ４８と、前記前後進切換装置８が前進状態
時に閉路する前進検出スイッチ４９と、前記前輪動力取
出ギヤ４０が前記ギヤ３７と噛み合って前輪４５を駆動
している時に閉路する前輪駆動検出スイッチ５０と、前
記スライドギヤ３３が前記クラッチギヤ３２と噛み合っ
ていない時に閉路する前輪自動変速切換スイッチ５１と
を介してバッテリ５２に電気的に接続されている。The electromagnetic clutch 30 is connected to the front wheel 4 as shown in FIG.
A turning detection switch 46 that closes when detecting that the steering wheel 5 has been operated close to the maximum steering angle; A shift detection switch 47, a creep detection switch 48 which is arranged in parallel to the auxiliary shift detection switch 47 and is closed when the creep device 11 is in the creep state, and a creep detection switch 48 which is closed when the forward/reverse switching device 8 is in the forward state. A forward movement detection switch 49, a front wheel drive detection switch 50 that is closed when the front wheel power take-off gear 40 is engaged with the gear 37 and driving the front wheels 45, and a front wheel drive detection switch 50 that is closed when the slide gear 33 is not engaged with the clutch gear 32. It is electrically connected to a battery 52 via a front wheel automatic transmission changeover switch 51 which is closed.
このような構成において、まず、エンジン２からの駆動
力は、メインクラッチ７から前後進切換装置８に伝達さ
れ、前後進切換装置８から主変速装置９と副変速装置１
ｏとクリープ装置１１とを介してドライブピニオン軸１
６に伝達され、さらに、後輪差動装置１３と最終減速装
置２０とを介して後輪２１に伝達され、後輪２】が回転
駆動される。In such a configuration, first, the driving force from the engine 2 is transmitted from the main clutch 7 to the forward/reverse switching device 8, and then from the forward/reverse switching device 8 to the main transmission 9 and the sub-transmission 1.
drive pinion shaft 1 via o and creep device 11
6, and is further transmitted to the rear wheels 21 via the rear wheel differential 13 and the final reduction gear 20, so that the rear wheels 2] are rotationally driven.
また、前輪動力取出ギヤ４０をスライドさせてギヤ３７
に噛み合わせると、前輪駆動検出スイッチ５０が閉路す
るとともにドライブピニオン軸１６の回転が中間ギヤ３
８に伝達され、低速側ギヤ２５と高速側ギヤ２６とが回
転する。ここで、スライドギヤ３３をスライドさせてク
ラッチギヤ３２に噛み合わせると、低速側ギヤ２５の回
転はスライドギヤ３３を介してギヤ２３に伝達され、さ
らに、ギヤ２３から前輪動力取出軸２２に伝達される。Also, slide the front wheel power take-off gear 40 to shift the gear 37.
When engaged, the front wheel drive detection switch 50 closes and the rotation of the drive pinion shaft 16 shifts to the intermediate gear 3.
8, and the low speed gear 25 and the high speed gear 26 rotate. Here, when the slide gear 33 is slid and engaged with the clutch gear 32, the rotation of the low speed gear 25 is transmitted to the gear 23 via the slide gear 33, and further transmitted from the gear 23 to the front wheel power take-off shaft 22. Ru.
そして、前輪動力取出軸２２からの駆動力伝達により前
輪４５が回転駆動され、トラクタ１は四輪駆動状態で走
行する。なお、この状態においては、前輪４５の周速度
と後輪２１の周速度とは略等し状態に維持されている。The front wheels 45 are rotationally driven by the driving force transmitted from the front wheel power extraction shaft 22, and the tractor 1 runs in a four-wheel drive state. In this state, the circumferential speed of the front wheel 45 and the circumferential speed of the rear wheel 21 are maintained substantially equal.
また、スライドギヤ３３をクラッチギヤ３２に噛み合わ
せることにより、前輪自動変速切換スイッチ５１が開路
し、電磁クラッチ３０は非通電状態に維持されている。Furthermore, by engaging the slide gear 33 with the clutch gear 32, the front wheel automatic transmission changeover switch 51 is opened, and the electromagnetic clutch 30 is maintained in a non-energized state.
つぎに、スライドギヤ３３をスライドさせてクラッチギ
ヤ３２との噛み合いを解除すると、前輪自動変速切換ス
イッチ５１が閉路するが、前輪４５が最大操向角度の近
傍まで操向操作されていない場合には旋回検出スイッチ
４６が開路しており、電磁クラッチ３０は非通電状態と
なっている。このため、スライドギヤ３３とクラッチギ
ヤ３２との噛み合いを解除してトラクタ１を直進状態又
は緩やかな旋回状態で走行させる場合は、低速側ギヤ２
５の回転はワンウェイクラッチ３１を介して前輪動力取
出軸２２に伝達され、前輪４５の周速度と後輪２１の周
速度とが略等しい状態に維持される。Next, when the slide gear 33 is slid to release the engagement with the clutch gear 32, the front wheel automatic transmission changeover switch 51 is closed, but if the front wheels 45 are not steered to near the maximum steering angle, The turning detection switch 46 is open, and the electromagnetic clutch 30 is in a de-energized state. Therefore, when the sliding gear 33 and the clutch gear 32 are disengaged and the tractor 1 is driven straight or in a gentle turning state, the low speed gear 2
5 is transmitted to the front wheel power take-off shaft 22 via the one-way clutch 31, and the circumferential speed of the front wheel 45 and the circumferential speed of the rear wheel 21 are maintained substantially equal.
ここで、スライドギヤ３３とクラッチギヤ３２との噛み
合いを解除することにより前輪自動変速切換スイッチ５
１を閉路し、前輪動力取出ギヤ４０をギヤ３７に噛み合
わせることにより前輪駆動検出スイッチ５０を閉路し、
前後進切換装置８を前進状態に操作することにより前進
検出スイッチ４９を閉路し、さらに、副変速装置１０を
高速状態以外の変速位置に操作するかクリープ装置１１
をクリープ状態に操作することによって副変速検出スイ
ッチ４７とクリープ検出スイッチ４８との少なくともい
ずれか一方を閉路した状態でトラクタ１を走行させてい
る際に、ハンドル（図示せず）の操向操作により操向輪
操作機構（図示せず）を介して前輪４５を最大操向角度
の近傍まで操向操作し、トラクタｌを急旋回させる。す
ると、前輪４５が最大操向角度の近傍まで操向操作され
たことを検出して旋回検出スイッチ４６が閉路する。Here, by releasing the engagement between the slide gear 33 and the clutch gear 32, the front wheel automatic transmission changeover switch 5
1, the front wheel drive detection switch 50 is closed by engaging the front wheel power take-off gear 40 with the gear 37,
The forward motion detection switch 49 is closed by operating the forward/reverse switching device 8 to the forward state, and the creep device 11 is further operated to shift the auxiliary transmission device 10 to a shift position other than the high speed state.
When the tractor 1 is running with at least one of the sub-shift detection switch 47 and the creep detection switch 48 closed by operating the auxiliary shift detection switch 47 and the creep detection switch 48 to the creep state, the The front wheels 45 are steered to near the maximum steering angle via a steering wheel operating mechanism (not shown), causing the tractor I to make a sharp turn. Then, it is detected that the front wheels 45 have been steered to near the maximum steering angle, and the turning detection switch 46 is closed.
これにより、直列に配列されたスイッチ４５〜５０が閉
路されて電磁クラッチ３０が作動し、高速側ギヤ２６の
回転は電磁クラッチ３０を介して前輪動力取出軸２２に
伝達され、前輪４５が回転駆動される。As a result, the switches 45 to 50 arranged in series are closed and the electromagnetic clutch 30 is activated, and the rotation of the high-speed gear 26 is transmitted to the front wheel power take-off shaft 22 via the electromagnetic clutch 30, and the front wheels 45 are rotationally driven. be done.
前輪４５への駆動力伝達が高速側ギヤ２６及び電磁クラ
ッチ３０を介して行われている急旋回時においては、前
輪４５の周速度が上昇し、前輪４５と後輪２１との旋回
中心が略一致する周速度比で前輪４５と後輪２１とが駆
動される。ここで、トラクタ１のように後輪差動装置１
３より後方に最終減速装置２０が設けられている場合は
、旋回時における差動抵抗が最終減速装置２０の減速比
に比例して増大し、旋回内側の後輪２１に大きな駆動力
が発生する。そして、この駆動力が旋回中のトラクタｌ
を直進させようとするために前輪４５にサイドフォース
が発生し、前輪４５がサイドスリップを生じて旋回半径
が大きくなる。しかし、制動装置１９が旋回内側の後輪
２１に抵抗を加えることにより、旋回内側の後輪２１に
発生する駆動力が低減され、前輪４５に発生するサイド
フォースも低減され、前輪４５のサイドスリップが防止
される。During sharp turns when the driving force is transmitted to the front wheels 45 via the high-speed gear 26 and the electromagnetic clutch 30, the circumferential speed of the front wheels 45 increases, and the turning center between the front wheels 45 and the rear wheels 21 is approximately The front wheels 45 and the rear wheels 21 are driven at the same peripheral speed ratio. Here, like the tractor 1, the rear wheel differential device 1
If the final reduction gear 20 is provided behind the wheel 3, the differential resistance during turning increases in proportion to the reduction ratio of the final reduction gear 20, and a large driving force is generated at the rear wheel 21 on the inside of the turn. . This driving force is applied to the turning tractor l.
In order to make the vehicle go straight, side force is generated on the front wheels 45, causing side slip in the front wheels 45 and increasing the turning radius. However, since the braking device 19 applies resistance to the rear wheel 21 on the inside of the turn, the driving force generated on the rear wheel 21 on the inside of the turn is reduced, the side force generated on the front wheel 45 is also reduced, and the side slip of the front wheel 45 is reduced. is prevented.
そこで、制動装置１９により旋回内側の後輪２１に抵抗
を加えながらトラクタ１を急旋回させると、トラクタ１
の旋回中心“０′”は、第５図に示すように後輪２１の
車軸延長線より前方に移動するとともに、前輪４５と後
輪２１との旋回中心が“Ｏ”となるような周速度比で前
輪４５と後輪２１とが駆動され、トラクタｌの旋回進行
方向“Ｆ”に対する垂線は旋回中心“○”と一致し、ト
ラクタ１は小さな旋回半径でスムーズに旋回する。また
、旋回軌跡に対して前輪４５と後輪２１とが傾いた状態
となっているが、前輪４５と後輪２１とは旋回軌跡の距
離比に応じた周速度で回転駆動されているため、前輪４
５や後輪２１が周方向にスリップすることによる土掻き
ゃ、前輪４５や後輪２１がサイドスリップすることによ
る土押出し等が防止され、旋回跡地が荒されない。Therefore, when the tractor 1 is made to make a sharp turn while applying resistance to the rear wheel 21 on the inside of the turn using the braking device 19, the tractor 1
The turning center "0'" of the front wheel 45 moves forward from the axle extension line of the rear wheel 21 as shown in FIG. The front wheels 45 and the rear wheels 21 are driven at the same ratio, the perpendicular to the turning direction "F" of the tractor 1 coincides with the turning center "○", and the tractor 1 turns smoothly with a small turning radius. In addition, although the front wheels 45 and the rear wheels 21 are in a state of inclination with respect to the turning trajectory, the front wheels 45 and the rear wheels 21 are rotationally driven at a circumferential speed according to the distance ratio of the turning trajectory. front wheel 4
Scraping of soil due to circumferential slip of the front wheels 45 and rear wheels 21, and extrusion of soil due to side slip of the front wheels 45 and rear wheels 21 are prevented, and the turning site is not disturbed.
また、トラクタ１が旋回を開始してから前輪４５の操向
角度が最大操向角度の近傍に至るまでの間は、前輪４５
と後輪２１との旋回半径の差によって前輪４５が後輪２
１に押される状態となる。Further, from the time when the tractor 1 starts turning until the steering angle of the front wheels 45 reaches the vicinity of the maximum steering angle, the front wheels 45
Due to the difference in turning radius between the front wheel 45 and the rear wheel 21, the front wheel 45
It will be pressed to 1.
すると、低速側ギヤ２５にワンウェイクラッチ３１を介
して連結されている前輪動力取出軸２２は低速側ギヤ２
５より高速で回転するため、前輪動力取出軸２２は自由
回転状態となり、前輪４５の周速度が前輪４５と後輪２
１との旋回軌跡の距離比に応じて速くなる。従って、旋
回を開始した直後であって前輪４５が高速状態に切換え
られる以前においても、前輪４５が後輪２１に押されて
転動するためにサイドスリップするということが防止さ
れ、前輪４５がサイドスリップすることにより旋回半径
が大きくなるということが防止される。Then, the front wheel power take-off shaft 22 connected to the low speed gear 25 via the one-way clutch 31 is connected to the low speed gear 25.
5, the front wheel power take-off shaft 22 is in a free rotation state, and the circumferential speed of the front wheel 45 is equal to that of the front wheel 45 and the rear wheel 2.
The speed increases according to the distance ratio of the turning trajectory to 1. Therefore, even immediately after starting a turn and before the front wheels 45 are switched to a high-speed state, side slip due to the front wheels 45 being pushed by the rear wheels 21 and rolling is prevented, and the front wheels 45 are prevented from moving sideways. This prevents the turning radius from increasing due to slipping.
さらに、電磁クラッチ３０が作動して前輪４５が高速状
態に切換えられる直前においては、前輪４５の周速度が
かなり速くなっており、高速状態への切換えを作業者に
ショックを与えることなくスムーズに行える。Furthermore, just before the electromagnetic clutch 30 is activated and the front wheels 45 are switched to a high-speed state, the circumferential speed of the front wheels 45 is considerably high, and the switch to a high-speed state can be smoothly performed without shocking the operator. .
トラクタ１の旋回が終了して前輪４５の操向角度が小さ
くなると、旋回検出スイッチ４６が開路して電磁クラッ
チ３０への通電が遮断される。そして、高速側ギヤ２６
から前輪動力取出軸２２への駆動力伝達が遮断され、ト
ラクタｌが直進走行状態に戻った際に再び低速側ギヤ２
５からワンウェイクラッチ３１を介して前輪動力取出軸
２２への駆動力伝達が行われ、前輪４５は後輪２１と略
等しい周速度で回転駆動される。When the turning of the tractor 1 is completed and the steering angle of the front wheels 45 becomes small, the turning detection switch 46 is opened and the energization to the electromagnetic clutch 30 is cut off. And high speed side gear 26
When the transmission of driving force from
5 to the front wheel power take-off shaft 22 via the one-way clutch 31, and the front wheels 45 are rotationally driven at substantially the same circumferential speed as the rear wheels 21.
なお、前後進切換装置８を後進位置に操作している場合
、又は、副変速装置１０を高速状態に操作するとともに
クリープ装置１１を非クリープ状態に操作している場合
は、前進検出スイッチ４９、又は、副変速検出スイッチ
４７とクリープ検出スイッチ４８とが開路されている。Note that when the forward/reverse switching device 8 is operated to the reverse position, or when the auxiliary transmission 10 is operated to a high speed state and the creep device 11 is operated to a non-creep state, the forward detection switch 49, Alternatively, the sub-shift detection switch 47 and the creep detection switch 48 are open.
従って、後進時や高速走行時において、最大操向角度に
操向操作してもトラクタ１が前輪４５の周速度を速くし
て急旋回するということが防止され、これらのスイッチ
４６〜４８は急旋回によるトラクタ１の転倒を防止する
安全機構としての働きをする。Therefore, when driving in reverse or at high speed, the tractor 1 is prevented from increasing the circumferential speed of the front wheels 45 and turning suddenly even if the steering operation is performed to the maximum steering angle. It functions as a safety mechanism to prevent the tractor 1 from falling due to turning.
発明の効果
本発明は、上述のように旋回内側の非操向輪にこの非操
向輪が回転可能な範囲で抵抗を加える制動装置を設けた
ことにより、旋回時において旋回内側の非操向輪に発生
する駆動力を低減させることができ、従って、この駆動
力により発生する操向輪のサイドフォースを低減して操
向輪のサイドスリップを防止することができ、さらに、
旋回時における操向輪と非操向輪との旋回中心が略一致
するように操向輪と非操向輪との周速度比を設定したこ
とにより、旋回時における操向輪と非操向輪との周方向
へのスリップやサイドスリップを防止して四輪駆動車輌
を小さな旋回半径でスムーズに旋回させることができ、
従って、周方向のスリップによる土掻きゃサイドスリッ
プによる土押出しを防止することができるとともに旋回
跡地を荒すことなく四輪駆動車輌を旋回させることがで
き、さらに、操向輪を最大操向角度の近傍に操向操作し
たときに高低速切換装置を低速側ギヤから高速側ギヤに
切換えるようにしたことにより、圃場内での旋回のよう
に急旋回を要する場合にのみ操向輪の周速度を上昇させ
て急旋回を行うことができる等の効果を有する。Effects of the Invention As described above, the present invention provides a braking device that applies resistance to the non-steered wheel on the inside of the turn within the range in which the non-steered wheel can rotate, thereby preventing the non-steered wheel on the inside of the turn when turning. The driving force generated in the wheels can be reduced, and therefore the side force of the steering wheels generated by this driving force can be reduced to prevent side slips of the steering wheels, and further,
By setting the circumferential speed ratio of the steered wheels and non-steered wheels so that the turning centers of the steered wheels and non-steered wheels when turning are approximately the same, the steered wheels and non-steered wheels when turning It prevents slips in the circumferential direction of the wheels and side slips, allowing four-wheel drive vehicles to turn smoothly with a small turning radius.
Therefore, it is possible to prevent dirt from being pushed out due to circumferential slips and side slips, and it is also possible to turn the four-wheel drive vehicle without roughening the turning area. By making the high-low speed switching device switch from low-speed gear to high-speed gear when a steering operation is performed nearby, the circumferential speed of the steering wheel can be changed only when a sharp turn is required, such as when turning in a field. It has the effect of being able to rise and make sharp turns.
ので、第１図は駆動力の伝達経路の全体を示す説明図、
第２図は前輪動力取出部を示す縦断側面図、第３図は電
磁クラッチ制御部を示す説明図、第４図はトラクタの全
体を示す側面図、第５図は旋回時における旋回作用の説
明図、第６図は従来例における旋回作用の説明図である
。Therefore, Figure 1 is an explanatory diagram showing the entire driving force transmission path.
Fig. 2 is a longitudinal side view showing the front wheel power take-off section, Fig. 3 is an explanatory view showing the electromagnetic clutch control section, Fig. 4 is a side view showing the entire tractor, and Fig. 5 is an explanation of the turning action during turning. 6 are explanatory diagrams of the turning action in the conventional example.
１・・・四輪駆動車輌、１５・・・高低速切換装置、１
９・・・制動装置、２１・・・非操向輪、２５・・・低
速側ギヤ、２６・・・高速側ギヤ、４５・・・操向輸出
願 人 石川島芝浦機械株式会社1... Four-wheel drive vehicle, 15... High/low speed switching device, 1
9...Brake device, 21...Non-steering wheel, 25...Low speed side gear, 26...High speed side gear, 45...Steering export Applicant: Ishikawajima Shibaura Machinery Co., Ltd.
第１図乃至第５図は本発明の一実施例を示すも、ｙ３３
図
３
図1 to 5 show an embodiment of the present invention.
Figure 3
Claims (1)
操作機構に応動して切り換えられる高低速切換装置を操
向輪駆動系に設け、直進時には前記低速側ギヤを介して
操向輪への駆動力伝達を行うとともに旋回時には前記高
速側ギヤを介して前記操向輪への駆動力伝達を行う四輪
駆動車輌において、旋回内側の非操向輪にこの非操向輪
が回転可能な範囲の抵抗を加える制動装置を設け、旋回
時における前記操向輪と前記非操向輪との旋回中心が略
一致するように前記操向輪と前記非操向輪との周速度比
を設定したことを特徴とする四輪駆動車輌の操向輪駆動
装置。 ２、操向輪を最大操向角度の近傍に操向操作したときに
高低速切換装置を低速側ギヤから高速側ギヤに切り換え
たことを特徴とする請求項１記載の四輪駆動車輌の操向
輪駆動装置。[Claims] 1. A high/low speed switching device having a low speed gear and a high speed gear and switching in response to a steering wheel operating mechanism is provided in the steering wheel drive system, and the low speed gear is switched when traveling straight. In a four-wheel drive vehicle, the driving force is transmitted to the steering wheel through the steering wheel, and when turning, the driving force is transmitted to the steering wheel through the high-speed side gear. A braking device is provided that applies resistance within a range that allows the steered wheels to rotate, and the steered wheels and the non-steered wheels are arranged so that the turning centers of the steered wheels and the non-steered wheels substantially coincide with each other during turning. A steering wheel drive device for a four-wheel drive vehicle, characterized in that a circumferential speed ratio of . 2. The four-wheel drive vehicle according to claim 1, wherein the high-low speed switching device is switched from a low-speed gear to a high-speed gear when the steering wheels are steered near a maximum steering angle. Wheel drive device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14568789A JPH0310937A (en) | 1989-06-08 | 1989-06-08 | Steering control wheel driving device of four-wheel drive automobile |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14568789A JPH0310937A (en) | 1989-06-08 | 1989-06-08 | Steering control wheel driving device of four-wheel drive automobile |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0310937A true JPH0310937A (en) | 1991-01-18 |
Family
ID=15390771
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14568789A Pending JPH0310937A (en) | 1989-06-08 | 1989-06-08 | Steering control wheel driving device of four-wheel drive automobile |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0310937A (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63162332A (en) * | 1986-12-26 | 1988-07-05 | Kubota Ltd | Agricultural tractor |
-
1989
- 1989-06-08 JP JP14568789A patent/JPH0310937A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63162332A (en) * | 1986-12-26 | 1988-07-05 | Kubota Ltd | Agricultural tractor |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPS59176121A (en) | Front wheel drive control unit for 4-wheel-drive car | |
| JP2007045177A (en) | Front wheel acceleration controller | |
| JPH0310937A (en) | Steering control wheel driving device of four-wheel drive automobile | |
| JPH0739700Y2 (en) | Turning control device for four-wheel drive vehicle | |
| JPH0310936A (en) | Steering control wheel driving device of four-wheel drive automobile | |
| JPS6235929B2 (en) | ||
| JP2622107B2 (en) | Front wheel drive control device for four-wheel drive agricultural tractor | |
| JP2908542B2 (en) | Steering device for four-wheel drive vehicle | |
| JPH0223449Y2 (en) | ||
| JP2507944B2 (en) | Front-wheel drive control device for four-wheel drive type power vehicle | |
| JP3318973B2 (en) | Tractor steering wheel drive | |
| JPH0624266Y2 (en) | Center differential device between front and rear wheels | |
| JP3489971B2 (en) | Work vehicle travel control device | |
| JP2513763Y2 (en) | Front wheel speed increasing device for four-wheel drive vehicle | |
| JP3368597B2 (en) | Traveling gear for mobile agricultural machines | |
| JP2694057B2 (en) | Travel transmission structure of work vehicle | |
| JP2538711B2 (en) | Transmission structure of work vehicle | |
| JP2861351B2 (en) | Front wheel acceleration control device for powered vehicle | |
| JPH0495580A (en) | Steering system for four-wheel drive vehicle | |
| JPS63306924A (en) | Front wheel speed-increasing mechanism for four-wheel-drive tractor | |
| JPH10129287A (en) | Traveling control device of moving vehicle | |
| JP2004189182A (en) | Steering turning controller for full crawler | |
| JP2808668B2 (en) | Front wheel drive for powered vehicles | |
| JPH02290725A (en) | Turning control device of tractor | |
| JPH02234843A (en) | Transmission for front-wheel of tractor |