JP2006035917A - Steering device for four-wheel steering vehicle - Google Patents

Steering device for four-wheel steering vehicle Download PDF

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JP2006035917A
JP2006035917A JP2004215054A JP2004215054A JP2006035917A JP 2006035917 A JP2006035917 A JP 2006035917A JP 2004215054 A JP2004215054 A JP 2004215054A JP 2004215054 A JP2004215054 A JP 2004215054A JP 2006035917 A JP2006035917 A JP 2006035917A
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steering
wheel
steer
wheels
cylinder
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JP4416594B2 (en
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Katsuhiko Shimada
克彦 島田
Kiyoyasu Hasegawa
清泰 長谷川
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TCM Corp
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TCM Corp
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Abstract

<P>PROBLEM TO BE SOLVED: To automatically change a traveling mode by switching on a traveling mode changeover switch, even if wheels are not precisely at neutral positions. <P>SOLUTION: The steering device for a four-wheel steering vehicle comprises right and left steering cylinders 8R, 8L, 18R, 18L respectively steering front wheels 1R, 1L and rear wheels 2R, 2L; a steering valve 23 and a mode selector valve 24 changing hydraulic pressure to the steering cylinders; and a controller 31 controlling the steering valve and the mode selector valve. Steering position sensors are respectively provided on the front wheels and the rear wheels. The controller 31 is provided with a neutral controlling portion 33 for controlling the steering valve 23 and the mode selector valve 24 by the traveling mode changeover switch 26 on the basis of a detection signal of the steering position sensor 41, and driving the front wheel and rear wheel steering cylinders to make the front wheels and the rear wheels neutral. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は、走行モード［二輪操舵、四輪（異相・同相）操舵など］を切換え可能な四輪操舵車両のステアリング装置に関する。   The present invention relates to a steering device for a four-wheel steering vehicle capable of switching a traveling mode [two-wheel steering, four-wheel (different phase / in-phase) steering, etc.].

従来、四輪操舵車両において走行モードを切換えるものが特許文献１に提案されている。特許文献１では、モード切換スイッチを入れて走行モードを切換えた場合、前輪および後輪が中立位置になるまでの間は、操作前の走行モードのランプを点灯させ、前輪および後輪が中立位置になると、走行モードを切換えると同時に操作後の走行モードの表示ランプを点灯させ、走行モードの切り換り時点を正確に運転者に告知することで、走行モードの誤認に基く操作ミスを防止している。
特開２００３−２５２２３０ Conventionally, Japanese Patent Application Laid-Open No. H10-228707 proposes a four-wheel steering vehicle that switches a traveling mode. In Patent Document 1, when the mode changeover switch is turned on and the driving mode is switched, the driving mode lamp before operation is turned on until the front wheel and the rear wheel are in the neutral position, and the front wheel and the rear wheel are in the neutral position. If this happens, the driving mode indicator lamp will light up at the same time as the driving mode is switched, and the driver will be notified of the time when the driving mode is switched accurately, thereby preventing operational errors based on misunderstanding of the driving mode. ing.
JP 2003-252230 A

しかしながら、上記従来装置では、前輪および後輪の中立位置表示ランプが点灯していない時には、モード切換スイッチの指示信号を無効とし、運転者がステアリングホイールを操作して中立位置になると前記指示信号を有効化している。したがって、運転者は、走行モードの切換えに際して、ステアリングホイールを操作して前輪および後輪をほぼ正確に中立位置に戻す必要があった。   However, in the above-described conventional device, when the neutral position indicator lamps for the front wheels and the rear wheels are not lit, the instruction signal of the mode changeover switch is invalidated and the instruction signal is displayed when the driver operates the steering wheel to the neutral position. Enabled. Therefore, the driver has to operate the steering wheel to return the front wheels and the rear wheels to the neutral position almost accurately when switching the traveling mode.

本発明は上記問題点を解決して、車輪が正確に中立位置になっていない状態でも、ステアリングの操作無に自動的に走行モードを切換えることができる四輪操舵車両のステアリング装置を提供することを目的とする。   The present invention solves the above problems and provides a steering device for a four-wheel steering vehicle capable of automatically switching the traveling mode without steering operation even when the wheels are not accurately in the neutral position. With the goal.

請求項１記載の発明は、左右の前輪をそれぞれ操舵する左右の前輪ステアシリンダおよび左右の後輪をそれぞれ操舵する左右の後輪ステアシリンダと、油圧供給装置から前輪ステアシリンダおよび後輪ステアシリンダへの油圧配管に介在されて前記前輪ステアシリンダおよび前記後輪ステアシリンダへの油圧を制御するステアバルブと、前記ステアバルブと後輪ステアシリンダの間の油圧配管に介在されて後輪ステアシリンダへの油圧を制御するモード切換バルブと、ステアリングホイールの操舵角に基いてステアバルブを操作するとともに、走行モード切換スイッチの操作信号に基いてモード切換バルブを操作するコントローラとを具備した四輪操舵車両のステアリング装置において、前記左右の前輪ステアシリンダおよび左右の後輪ステアシリンダに、伸縮状態を検出可能なステア位置センサをそれぞれ設け、前記コントローラに、走行モード切換スイッチによるモード切換信号により、前記ステア位置センサの検出信号に基いて左右の前輪および左右の後輪がそれぞれ中立位置になるように前輪ステアシリンダおよび後輪ステアシリンダを制御する中立制御部を設けたものである。   According to the first aspect of the present invention, the left and right front wheel steering cylinders that respectively steer the left and right front wheels and the left and right rear wheel steering cylinders that respectively steer the left and right rear wheels, and the hydraulic supply device to the front wheel steering cylinder and the rear wheel steering cylinder. A steering valve for controlling the hydraulic pressure to the front wheel steering cylinder and the rear wheel steering cylinder, and a hydraulic piping between the steering valve and the rear wheel steering cylinder to the rear wheel steering cylinder. A four-wheel steering vehicle comprising a mode switching valve that controls hydraulic pressure, and a controller that operates a steering valve based on a steering angle of a steering wheel and operates a mode switching valve based on an operation signal of a travel mode switching switch. In the steering device, the left and right front wheel steering cylinders and the left and right rear wheel steering wheels The cylinder is provided with a steer position sensor capable of detecting the expansion / contraction state, and the controller controls the left and right front wheels and the left and right rear wheels based on the detection signal of the steer position sensor by a mode switching signal by a travel mode changeover switch. A neutral control unit for controlling the front wheel steering cylinder and the rear wheel steering cylinder so as to be in the neutral position is provided.

請求項２記載の発明は、左右のステア位置センサは、ステアシリンダのピストンロッドに取り付けられた検出体と、中立位置を越えた伸長状態または中立位置未満の短縮状態のいずれか一方で前記検出体を検出可能な近接スイッチとを具備し、左右のステア位置センサにより前輪および後輪の転舵方向と中立位置とが検出可能に構成されたものである。   According to a second aspect of the present invention, the left and right steering position sensors are either a detection body attached to a piston rod of a steering cylinder, and the detection body in either an extended state exceeding a neutral position or a shortened state less than a neutral position. And a steer position sensor for detecting the steering direction of the front and rear wheels and a neutral position.

請求項３記載の発明は、コントローラの中立制御部は、走行モード切換スイッチのモード切換信号に基いて、ステアバルブおよびモード切換バルブを制御し、まず後輪の左右のステア位置センサがそれぞれ非検出の中立位置となるように後輪ステアシリンダを制御し、次いで前記モード切換バルブを二輪操舵モードとした後、前輪の左右のステア位置センサがそれぞれ非検出の中立位置となるように前輪ステアシリンダを制御するように構成されたものである。   According to a third aspect of the present invention, the neutral controller of the controller controls the steering valve and the mode switching valve on the basis of the mode switching signal of the travel mode changeover switch. First, the left and right steering position sensors of the rear wheels are not detected. After the rear wheel steer cylinder is controlled to be in the neutral position and then the mode switching valve is set to the two-wheel steering mode, the front wheel steer cylinder is adjusted so that the left and right steer position sensors of the front wheels are in the non-detected neutral positions. It is configured to control.

請求項１記載の発明によれば、中立制御部により、ステア位置センサの検出信号に基いて前輪ステアシリンダおよび後輪ステアシリンダを駆動し車輪を中立位置に自動的に戻すことができるので、運転者が走行モード変更ごとに、いちいち車輪を中立位置に戻すことなく、モード切換スイッチを入れるだけでよい。したがって、走行モードの切換えを容易に行うことができる。   According to the first aspect of the present invention, the neutral control unit can drive the front wheel steering cylinder and the rear wheel steering cylinder based on the detection signal of the steering position sensor to automatically return the wheels to the neutral position. Every time the person changes the driving mode, the mode switch is simply turned on without returning the wheel to the neutral position. Therefore, the driving mode can be easily switched.

請求項２記載の発明によれば、左右のステアシリンダで伸長位置または短縮位置の一方で近接スイッチにより検出体を検出することで、簡単な部材の追加取付で中立位置と車輪の転舵方向を正確に判断することができ、中立位置に復帰させる動作を容易かつ迅速に行うことができる。   According to the second aspect of the present invention, the detection position is detected by the proximity switch in either the extended position or the shortened position in the left and right steer cylinders, so that the neutral position and the steered direction of the wheel can be set by adding a simple member. It is possible to accurately determine and to easily and quickly perform the operation of returning to the neutral position.

請求項３記載の発明によれば、二輪操舵および四輪操舵時における車輪の位相ずれをそれぞれ確実に吸収して前後の車輪を中立位置に迅速に復帰させることができ、モード切換動作を迅速かつ正確に実施することができる。   According to the third aspect of the present invention, it is possible to reliably absorb the phase shifts of the wheels during two-wheel steering and four-wheel steering, respectively, and to quickly return the front and rear wheels to the neutral position, so that the mode switching operation can be performed quickly and easily. Can be implemented accurately.

以下、本発明の実施の形態を図面に基づいて説明する。
この四輪操舵車両のステアリング装置は、四輪異相操舵により旋回半径を小さくしたり、四輪同相操舵により斜行走行を可能として狭い通路を走行可能としたもので、経済走行が可能な二輪操舵にも切換え可能で、走行モードの切換時に車輪の中立位置を把握しにくいたとえば無線操作車両などに適したものである。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.
This four-wheel steering vehicle steering device is a two-wheel steering capable of economical driving by reducing the turning radius by four-phase out-of-phase steering or by allowing the four-wheel in-phase steering to run obliquely and traveling in a narrow path. This is suitable for, for example, a radio-operated vehicle in which it is difficult to grasp the neutral position of the wheel when the traveling mode is switched.

図１および図２に示すように、たとえば荷を搭載して所定経路を搬送する搬送台車装置で、車体１０の前部に独立操舵可能な左右一対の前輪１Ｒ，１Ｌが設けられ、後部に独立操舵可能な左右一対の後輪２Ｒ，２Ｌが設けられている。   As shown in FIG. 1 and FIG. 2, for example, in a transport carriage device that carries a load and transports a predetermined route, a pair of left and right front wheels 1 </ b> R and 1 </ b> L that can be independently steered are provided at the front portion of the vehicle body 10. A pair of left and right rear wheels 2R, 2L that can be steered are provided.

すなわち、前部車体フレーム３には、キングピン４Ｒ，４Ｌを介して転舵自在な左右のナックルシャフト５Ｒ，５Ｌが取り付けられ、ナックルシャフト５Ｒ，５Ｌにホイールモータ６Ｒ，６Ｌを介して前輪１Ｒ，１Ｌが取り付けられている。また左右のナックルシャフト５Ｒ，５Ｌは、ナックルアームを介してタイロッド７がピン連結されて互いに連動されている。そして、シリンダ本体８ａが前部車体フレーム３に連結支持された左右の前輪ステアシリンダ８Ｒ，８Ｌのピストンロッド８ｂがステアアーム９Ｒ，９Ｌを介してナックルシャフト５Ｒ，５Ｌにピン連結されている。   That is, left and right knuckle shafts 5R and 5L that can be steered are attached to the front body frame 3 via king pins 4R and 4L, and the front wheels 1R and 1L are attached to the knuckle shafts 5R and 5L via the wheel motors 6R and 6L. Is attached. The left and right knuckle shafts 5R and 5L are interlocked with each other by pin-connecting tie rods 7 via knuckle arms. The piston rods 8b of the left and right front steering cylinders 8R, 8L, in which the cylinder body 8a is connected to and supported by the front body frame 3, are pin-connected to the knuckle shafts 5R, 5L via the steering arms 9R, 9L.

また後部車体フレーム１３には、キングピン１４Ｒ，１４Ｌを介して転舵自在な左右のナックルシャフト１５Ｒ，１５Ｌが取り付けられ、ナックルシャフト１５Ｒ，１５Ｌにホイールモータ１６Ｒ，１６Ｌを介して前輪１１Ｒ，１１Ｌが取り付けられている。また左右のナックルシャフト１５Ｒ，１５Ｌは、ナックルアームを介してタイロッド１７によりピン連結されて互いに連動されている。そして、シリンダ本体１８ａが前部車体フレーム３Ｆに連結支持された左右の前部ステアシリンダ１８Ｒ，１８Ｌのピストンロッド１８ｂがステアアーム１９Ｒ，１９Ｌを介してナックルシャフト１５Ｒ，１５Ｌにピン連結されている。   Further, left and right knuckle shafts 15R and 15L that can be steered are attached to the rear body frame 13 via king pins 14R and 14L, and front wheels 11R and 11L are attached to the knuckle shafts 15R and 15L via wheel motors 16R and 16L. It has been. The left and right knuckle shafts 15R and 15L are connected to each other by being pin-connected by a tie rod 17 via a knuckle arm. The piston rods 18b of the left and right front steering cylinders 18R and 18L, in which the cylinder body 18a is connected to and supported by the front body frame 3F, are pin-connected to the knuckle shafts 15R and 15L via the steering arms 19R and 19L.

さらに図３に示すように、車体１０に設けられた油圧ポンプ（油圧供給装置）２１から油圧が油圧配管２２Ａ，２２Ｂを介して各ステアシリンダ８Ｒ，８Ｌ，１８Ｒ，１８Ｌに給排出されている。すなわち、エンジン（図示せず）により駆動される油圧ポンプ２１と前輪ステアシリンダ８Ｒ，８Ｌとの間に接続された第１油圧配管２２に電磁式ステアバルブ２３が介在され、ステアバルブ２３と前輪ステアシリンダ８Ｒ，８Ｌの間の油圧配管２２Ａから分岐されて後輪ステアシリンダ１８Ｒ，１８Ｌに接続された第２油圧配管２２Ｂに電磁式モード切換バルブ２４が介在されている。   Further, as shown in FIG. 3, hydraulic pressure is supplied to and discharged from each of the steer cylinders 8R, 8L, 18R, and 18L via hydraulic pipes 22A and 22B from a hydraulic pump (hydraulic supply device) 21 provided in the vehicle body 10. That is, an electromagnetic steer valve 23 is interposed in a first hydraulic pipe 22 connected between a hydraulic pump 21 driven by an engine (not shown) and the front wheel steer cylinders 8R and 8L, and the steer valve 23 and the front wheel steer are interposed. An electromagnetic mode switching valve 24 is interposed in a second hydraulic pipe 22B branched from the hydraulic pipe 22A between the cylinders 8R and 8L and connected to the rear wheel steering cylinders 18R and 18L.

車体１０に設けられたコントローラ３１には、ステアリングホイール２５に設けられた操舵角検出器２７の信号に基いてステアバルブ２３を制御し、車輪１Ｒ，１Ｌ，２Ｒ，２Ｌを転舵するステアリング制御部３２と、走行モード切換スイッチ２６の操作信号に基いて車輪１Ｒ，１Ｌ，２Ｒ，２Ｌを中立位置に戻すとともにモード切換バルブ２４を制御して走行モード（二輪操舵、四輪異相操舵、四輪同相操舵）を切換える中立制御部３３が具備されている。また前輪１Ｒ，１Ｌと後輪２Ｒ，２Ｌとがリンクなどで結合されていないため、油圧配分の誤差などに起因して後輪２Ｒ，２Ｌに舵角異常が発生するのを防止するために、前記ステアリング制御部３２には、前輪１Ｒ，１Ｌが中立位置の時にモード切換バルブ２４を操作して後輪２Ｒ，２Ｌを中立位置に復帰させるリセット機能が具備されている。   A controller 31 provided in the vehicle body 10 controls a steering valve 23 based on a signal from a steering angle detector 27 provided in the steering wheel 25 to steer the wheels 1R, 1L, 2R, 2L. 32, the wheels 1R, 1L, 2R, 2L are returned to the neutral position based on the operation signal of the travel mode changeover switch 26, and the mode switch valve 24 is controlled to control the travel mode (two-wheel steering, four-wheel different phase steering, four-wheel in-phase steering). A neutral control unit 33 for switching (steering) is provided. In addition, since the front wheels 1R, 1L and the rear wheels 2R, 2L are not connected by a link or the like, in order to prevent a steering angle abnormality from occurring in the rear wheels 2R, 2L due to an error in hydraulic pressure distribution, etc. The steering control unit 32 has a reset function for operating the mode switching valve 24 to return the rear wheels 2R and 2L to the neutral position when the front wheels 1R and 1L are in the neutral position.

車輪１Ｒ，１Ｌ，２Ｒ，２Ｌの中立位置をそれぞれ検出するステア位置センサ４１は、図４、図５に示すように、ステアシリンダ８Ｒ，８Ｌ，１８Ｒ，１８Ｌのピストンロッド８ｂの側部に支持金具４２を介して出退方向に沿って検出体（プレート）４３が出退方向に沿って取り付けられている。一方、ステアシリンダ８Ｒ，８Ｌ，１８Ｒ，１８Ｌの本体８ａには、検出体４３が挿通可能なコの字形のブラケット４４が取付金具４５を介して取り付けられ、ブラケット４４に検出体４３を検出可能な近接スイッチ４６が取付けられている。そして検出体４３の長さと近接スイッチ４６に対する位置関係は、車輪１Ｒ，１Ｌ，２Ｒ，２Ｌの中立位置を越えてステアシリンダ８Ｒ，８Ｌ，１８Ｒ，１８Ｌが伸長される全伸長ストロークにわたって近接スイッチ４６が検出体４３を検出可能の構成される。したがって、左右のステアシリンダ８Ｒ，８Ｌ，１８Ｒ，１８Ｌの一方のステア位置センサ４１がオン（近接スイッチ４６が検出体４３を検出）されると、車輪１Ｒ，１Ｌ，２Ｒ，２Ｌの転舵方向を判断することができ、中立位置に復帰させる補正動作を容易に行うことができる。なお、中立位置未満の全短縮ストロークを検出するようにしてもよい。   As shown in FIGS. 4 and 5, the steering position sensor 41 for detecting the neutral positions of the wheels 1R, 1L, 2R, and 2L is supported on the side of the piston rod 8b of the steering cylinders 8R, 8L, 18R, and 18L. A detection body (plate) 43 is attached along the exit / retreat direction via 42. On the other hand, a U-shaped bracket 44 through which the detection body 43 can be inserted is attached to the main body 8a of the steer cylinders 8R, 8L, 18R, 18L via a mounting bracket 45, and the detection body 43 can be detected by the bracket 44. A proximity switch 46 is attached. The positional relationship between the length of the detection body 43 and the proximity switch 46 is such that the proximity switch 46 extends over the entire extension stroke in which the steering cylinders 8R, 8L, 18R, 18L extend beyond the neutral positions of the wheels 1R, 1L, 2R, 2L. The detection body 43 can be detected. Therefore, when one of the steering position sensors 41 of the left and right steering cylinders 8R, 8L, 18R, 18L is turned on (the proximity switch 46 detects the detection body 43), the steering direction of the wheels 1R, 1L, 2R, 2L is changed. It is possible to make a determination, and it is possible to easily perform a correction operation for returning to the neutral position. In addition, you may make it detect all the shortening strokes less than a neutral position.

次に図６を参照してモード切換動作を説明する。
（二輪操舵）
走行モード切換スイッチ２６が操作され(ＳＴＥＰ１)、二輪操舵が選択される（ＳＴＥＰ２）と、コントローラ３１の中立制御部３３では、後輪２Ｒ，２Ｌのステア位置センサ４１，４１の検出信号に基いて後輪２Ｒ，２Ｌが中立位置かどうかが判断される（ＳＴＥＰ３）。そして後輪２Ｒ，２Ｌが中立位置でない場合には、中立制御部３３の操作信号によりステアバルブ２３が中立位置（非接続位置）以外に、モード切換バルブ２４が四輪操舵位置にそれぞれ操作されて後輪２Ｒ，２Ｌが中立位置となる方向に転舵される（ＳＴＥＰ４）。そして後輪２Ｒ，２Ｌが中立位置になる（ＳＴＥＰ５）と、モード切換バルブ２４が二輪操舵位置（非接続位置）に切換えられる（ＳＴＥＰ６）。さらにステアバルブ２３から前輪ステアシリンダ８Ｒ，８Ｌに送られる油圧により前輪１Ｒ，１Ｌが転舵されており、前輪１Ｒ，１Ｌが中立位置になる（ＳＴＥＰ７）と、前輪１Ｒ，１Ｌが中立位置になると、既にモード切換バルブ２４が二輪操舵位置に操作されているので、二輪操舵の切換動作が完了する（ＳＴＥＰ８）。
（四輪異相操舵）
走行モード切換スイッチ２６が操作され(ＳＴＥＰ１)、四輪異相操舵が選択される（ＳＴＥＰ１２）と、コントローラ３１の中立制御部３３では、後輪２Ｒ，２Ｌのステア位置センサ４１，４１の検出信号に基いて後輪２Ｒ，２Ｌが中立位置かどうかが判断される（ＳＴＥＰ１３）。そして後輪２Ｒ，２Ｌが中立位置でない場合には、中立制御部３３の操作信号によりステアバルブ２３が中立位置（非接続位置）以外に、モード切換バルブ２４が四輪操舵位置にそれぞれ操作されて後輪２Ｒ，２Ｌが中立位置となる方向に転舵される（ＳＴＥＰ１４）。そして後輪２Ｒ，２Ｌが中立位置となる（ＳＴＥＰ１５）と、モード切換バルブ２４が二輪操舵位置（非接続位置）に切換えられる（ＳＴＥＰ１６）。さらにステアバルブ２３から前輪ステアシリンダ８Ｒ，８Ｌに送られる油圧により前輪１Ｒ，１Ｌが転舵されており、前輪１Ｒ，１Ｌが中立位置かどうかが判断される（ＳＴＥＰ１７）。前輪１Ｒ，１Ｌが中立位置となると、モード切換バルブ２４が四輪異相操舵位置に操作され（ＳＴＥＰ１８）、四輪異相操舵の切換動作が完了する（ＳＴＥＰ１９）。
（四輪異相操舵）
走行モード切換スイッチ２６が操作され(ＳＴＥＰ１)、四輪同相操舵が選択される（ＳＴＥＰ２２）と、コントローラ３１の中立制御部３３では、後輪２Ｒ，２Ｌのステア位置センサ４１，４１の検出信号に基いて後輪２Ｒ，２Ｌが中立位置かどうかが判断される（ＳＴＥＰ２３）。そして後輪２Ｒ，２Ｌが中立位置でない場合には、中立制御部３３の操作信号によりステアバルブ２３が中立位置（非接続位置）以外に、モード切換バルブ２４が四輪操舵位置にそれぞれ操作されて後輪２Ｒ，２Ｌが中立位置となる方向に転舵される（ＳＴＥＰ２４）。そして後輪２Ｒ，２Ｌが中立位置となる（ＳＴＥＰ１５）と、モード切換バルブ２４が二輪操舵位置（非接続位置）に切換えられる（ＳＴＥＰ１６）。さらにステアバルブ２３から前輪ステアシリンダ８Ｒ，８Ｌに送られる油圧により前輪１Ｒ，１Ｌが転舵されており、前輪１Ｒ，１Ｌが中立位置かどうかが判断される（ＳＴＥＰ２７）。前輪１Ｒ，１Ｌが中立位置となると、モード切換バルブ２４が四輪同相操舵位置に操作され（ＳＴＥＰ２８）、四輪同相操舵の切換動作が完了する（ＳＴＥＰ２９）。 Next, the mode switching operation will be described with reference to FIG.
(Two-wheel steering)
When the travel mode changeover switch 26 is operated (STEP 1) and two-wheel steering is selected (STEP 2), the neutral control unit 33 of the controller 31 is based on detection signals from the steer position sensors 41 and 41 of the rear wheels 2R and 2L. It is determined whether or not the rear wheels 2R and 2L are in the neutral position (STEP 3). When the rear wheels 2R, 2L are not in the neutral position, the steering valve 23 is operated to the four-wheel steering position in addition to the steering valve 23 other than the neutral position (disconnected position) by the operation signal of the neutral control unit 33. The rear wheels 2R and 2L are steered in a direction where the rear wheels 2R and 2L are in the neutral position (STEP 4). When the rear wheels 2R and 2L are in the neutral position (STEP 5), the mode switching valve 24 is switched to the two-wheel steering position (non-connection position) (STEP 6). Further, the front wheels 1R, 1L are steered by the hydraulic pressure sent from the steer valve 23 to the front wheel steering cylinders 8R, 8L. When the front wheels 1R, 1L are in the neutral position (STEP 7), the front wheels 1R, 1L are in the neutral position. Since the mode switching valve 24 has already been operated to the two-wheel steering position, the two-wheel steering switching operation is completed (STEP 8).
(Four wheel out of phase steering)
When the travel mode changeover switch 26 is operated (STEP 1) and four-wheel different phase steering is selected (STEP 12), the neutral control unit 33 of the controller 31 uses the detection signals of the steer position sensors 41 and 41 of the rear wheels 2R and 2L. Based on this, it is determined whether or not the rear wheels 2R and 2L are in the neutral position (STEP 13). When the rear wheels 2R, 2L are not in the neutral position, the steering valve 23 is operated to the four-wheel steering position in addition to the steering valve 23 other than the neutral position (disconnected position) by the operation signal of the neutral control unit 33. The rear wheels 2R and 2L are steered in a direction where they become neutral positions (STEP 14). When the rear wheels 2R and 2L are in the neutral position (STEP 15), the mode switching valve 24 is switched to the two-wheel steering position (non-connection position) (STEP 16). Further, the front wheels 1R and 1L are steered by the hydraulic pressure sent from the steering valve 23 to the front wheel steering cylinders 8R and 8L, and it is determined whether or not the front wheels 1R and 1L are in the neutral position (STEP 17). When the front wheels 1R and 1L are in the neutral position, the mode switching valve 24 is operated to the four-wheel different phase steering position (STEP 18), and the four-wheel different phase steering switching operation is completed (STEP 19).
(Four wheel out of phase steering)
When the travel mode changeover switch 26 is operated (STEP 1) and four-wheel in-phase steering is selected (STEP 22), the neutral control unit 33 of the controller 31 uses the detection signals of the steer position sensors 41 and 41 of the rear wheels 2R and 2L. Based on this, it is determined whether or not the rear wheels 2R and 2L are in the neutral position (STEP 23). When the rear wheels 2R, 2L are not in the neutral position, the steering valve 23 is operated to the four-wheel steering position in addition to the steering valve 23 other than the neutral position (disconnected position) by the operation signal of the neutral control unit 33. The rear wheels 2R and 2L are steered in the direction where they are in the neutral position (STEP 24). When the rear wheels 2R and 2L are in the neutral position (STEP 15), the mode switching valve 24 is switched to the two-wheel steering position (non-connection position) (STEP 16). Further, the front wheels 1R and 1L are steered by the hydraulic pressure sent from the steering valve 23 to the front wheel steering cylinders 8R and 8L, and it is determined whether or not the front wheels 1R and 1L are in the neutral position (STEP 27). When the front wheels 1R and 1L are in the neutral position, the mode switching valve 24 is operated to the four-wheel in-phase steering position (STEP 28), and the four-wheel in-phase steering switching operation is completed (STEP 29).

上記実施の形態によれば、コントローラ３１に設けられた中立制御部３３により、ステア位置センサ４１の検出信号に基いて前輪ステアシリンダ８Ｒ，８Ｌおよび後輪ステアシリンダ１８Ｒ，１８Ｌを駆動し車輪１Ｒ，１Ｌ，２Ｒ，２Ｌを中立位置に自動的に戻すことができるので、運転者がいちいち車輪を中立位置に戻す必要が無くなり、走行モード切換スイッチ２６を入れるだけでよい。したがって、走行モードの切換えを容易に行うことができる。   According to the above embodiment, the neutral control unit 33 provided in the controller 31 drives the front wheel steer cylinders 8R, 8L and the rear wheel steer cylinders 18R, 18L based on the detection signal of the steer position sensor 41, and the wheels 1R, Since 1L, 2R, and 2L can be automatically returned to the neutral position, it is not necessary for the driver to return the wheel to the neutral position one by one, and only the traveling mode changeover switch 26 is turned on. Therefore, the driving mode can be easily switched.

ステア位置センサ４１により左右のステアシリンダ８Ｒ，８Ｌ，１８Ｒ，１８Ｌの伸長位置または短縮位置の一方をそれぞれ検出することで、車輪１Ｒ，１Ｌ，２Ｒ，２Ｌの転舵方向を正確に判断することができ、車輪１Ｒ，１Ｌ，２Ｒ，２Ｌを中立位置に復帰させるステアバルブ２３およびモード切換バルブ２４の動作を容易かつ迅速に行うことができる。   By detecting one of the extended or shortened positions of the left and right steering cylinders 8R, 8L, 18R, and 18L by the steering position sensor 41, the steering direction of the wheels 1R, 1L, 2R, and 2L can be accurately determined. In addition, the steering valve 23 and the mode switching valve 24 that return the wheels 1R, 1L, 2R, and 2L to the neutral position can be easily and quickly operated.

後輪２Ｒ，２Ｌを中立位置に戻した後、前輪１Ｒ，１Ｌを中立位置に戻す動作により、二輪操舵および四輪操舵時における車輪１Ｒ，１Ｌ，２Ｒ，２Ｌの位相ずれをそれぞれ確実に吸収して前後の車輪１Ｒ，１Ｌ，２Ｒ，２Ｌを迅速に中立位置に復帰させることができ、モード切換動作を迅速かつ正確に実施することができる。   After returning the rear wheels 2R, 2L to the neutral position, the operation of returning the front wheels 1R, 1L to the neutral position reliably absorbs the phase shift of the wheels 1R, 1L, 2R, 2L during two-wheel steering and four-wheel steering. Thus, the front and rear wheels 1R, 1L, 2R, 2L can be quickly returned to the neutral position, and the mode switching operation can be performed quickly and accurately.

本発明に係るステアリング装置を有する四輪操舵車両の実施の形態を示す全体平面図である。1 is an overall plan view showing an embodiment of a four-wheel steering vehicle having a steering device according to the present invention. 同四輪操舵車両のステアリング状態を示す全体平面図である。It is a whole top view which shows the steering state of the same four-wheel steering vehicle. 同ステアリング装置を示す全体構成図である。It is a whole lineblock diagram showing the steering device. 同ステア位置センサの取付状態を示す側面図である。It is a side view which shows the attachment state of the same steer position sensor. 図４に示すＡ−Ａ断面図である。It is AA sectional drawing shown in FIG. ステアリング装置における走行モード切換動作を説明するフロー図である。It is a flowchart explaining the driving mode switching operation in a steering device.

符号の説明Explanation of symbols

１Ｒ，１Ｌ 前輪
２Ｒ，２Ｌ 後輪
６Ｒ，６Ｌ ホイールモータ
８Ｒ，８Ｌ 前輪ステアシリンダ
８ａ シリンダ本体
８ｂ ピストンロッド
９Ｒ，９Ｌ ステアアーム
１８Ｒ，１８Ｌ 前輪ステアシリンダ
２０ エンジン
２１ 油圧ポンプ
２２Ａ 第１油圧配管
２２Ｂ 第２油圧配管
２３ ステアバルブ
２４ モード切換バルブ
２５ ステアリングホイール
２６ 走行モード切換スイッチ
２７ 操舵角検出器
３１ コントローラ
３２ ステアリング制御部
３３ 中立制御部
４１ ステア位置センサ
４３ 検出体
４６ 近接スイッチ 1R, 1L Front wheel 2R, 2L Rear wheel 6R, 6L Wheel motor 8R, 8L Front wheel steer cylinder 8a Cylinder body 8b Piston rod 9R, 9L Steer arm 18R, 18L Front wheel steer cylinder 20 Engine 21 Hydraulic pump 22A First hydraulic piping 22B Second Hydraulic piping 23 Steer valve 24 Mode switching valve 25 Steering wheel 26 Travel mode switching switch 27 Steering angle detector 31 Controller 32 Steering control unit 33 Neutral control unit 41 Steer position sensor 43 Detector 46 Proximity switch

Claims (3)

左右の前輪をそれぞれ操舵する左右の前輪ステアシリンダおよび左右の後輪をそれぞれ操舵する左右の後輪ステアシリンダと、油圧供給装置から前輪ステアシリンダおよび後輪ステアシリンダへの油圧配管に介在されて前記前輪ステアシリンダおよび前記後輪ステアシリンダへの油圧を制御するステアバルブと、前記ステアバルブと後輪ステアシリンダの間の油圧配管に介在されて後輪ステアシリンダへの油圧を制御するモード切換バルブと、ステアリングホイールの操舵角に基いてステアバルブを操作するとともに、走行モード切換スイッチの操作信号に基いてモード切換バルブを操作するコントローラとを具備した四輪操舵車両のステアリング装置において、
前記左右の前輪ステアシリンダおよび左右の後輪ステアシリンダに、伸縮状態を検出可能なステア位置センサをそれぞれ設け、
前記コントローラに、走行モード切換スイッチによるモード切換信号により、前記ステア位置センサの検出信号に基いて左右の前輪および左右の後輪がそれぞれ中立位置になるように前輪ステアシリンダおよび後輪ステアシリンダを制御する中立制御部を設けた
ことを特徴とする四輪操舵車両のステアリング装置。 The left and right front wheel steering cylinders that respectively steer the left and right front wheels, the left and right rear wheel steering cylinders that respectively steer the left and right rear wheels, and the hydraulic piping from the hydraulic supply device to the front wheel steering cylinder and the rear wheel steering cylinder A steering valve for controlling the hydraulic pressure to the front wheel steering cylinder and the rear wheel steering cylinder, and a mode switching valve for controlling the hydraulic pressure to the rear wheel steering cylinder interposed in the hydraulic piping between the steering valve and the rear wheel steering cylinder; A steering device for a four-wheel steering vehicle comprising a controller for operating a steering valve based on a steering angle of a steering wheel and operating a mode switching valve based on an operation signal of a travel mode switching switch.
The left and right front wheel steer cylinders and the left and right rear wheel steer cylinders are each provided with a steer position sensor capable of detecting a telescopic state,
The controller controls the front wheel steering cylinder and the rear wheel steering cylinder based on the detection signal of the steering position sensor so that the left and right front wheels and the left and right rear wheels are in the neutral position based on a detection signal from the steering mode sensor. A steering device for a four-wheel steering vehicle, characterized in that a neutral control unit is provided. 左右のステア位置センサは、ステアシリンダのピストンロッドに取り付けられた検出体と、中立位置を越えた伸長状態または中立位置未満の短縮状態のいずれか一方で前記検出体を検出可能な近接スイッチとを具備し、左右のステア位置センサにより前輪および後輪の転舵方向と中立位置とが検出可能に構成された
ことを特徴とする請求項１記載の四輪操舵車両のステアリング装置。 The left and right steering position sensors include a detection body attached to the piston rod of the steering cylinder and a proximity switch that can detect the detection body in either an extended state exceeding the neutral position or a shortened state less than the neutral position. The steering device for a four-wheel steering vehicle according to claim 1, wherein the steering device is configured to detect the steering direction and the neutral position of the front and rear wheels by left and right steering position sensors. コントローラの中立制御部は、走行モード切換スイッチのモード切換信号に基いて、ステアバルブおよびモード切換バルブを制御し、まず後輪の左右のステア位置センサがそれぞれ非検出の中立位置となるように後輪ステアシリンダを制御し、次いで前記モード切換バルブを二輪操舵モードとした後、前輪の左右のステア位置センサがそれぞれ非検出の中立位置となるように前輪ステアシリンダを制御するように構成された
ことを特徴とする請求項２記載の四輪操舵車両のステアリング装置。 The neutral controller of the controller controls the steering valve and the mode switching valve based on the mode switching signal of the travel mode selector switch. First, the rear wheel left and right steering position sensors are respectively set to the non-detected neutral positions. After the wheel steer cylinder is controlled and then the mode switching valve is set to the two-wheel steering mode, the front wheel steer cylinder is controlled so that the left and right steer position sensors of the front wheels are in neutral positions that are not detected. The steering device for a four-wheel steering vehicle according to claim 2.
JP2004215054A 2004-07-23 2004-07-23 Steering device for four-wheel steering vehicle Expired - Fee Related JP4416594B2 (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2537733A1 (en) 2011-06-20 2012-12-26 Jtekt Corporation Rear wheel steering system
WO2013129090A1 (en) * 2012-02-29 2013-09-06 日立建機株式会社 Steering device for vehicle

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2537733A1 (en) 2011-06-20 2012-12-26 Jtekt Corporation Rear wheel steering system
US8672084B2 (en) 2011-06-20 2014-03-18 Jtekt Corporation Rear wheel steering system
WO2013129090A1 (en) * 2012-02-29 2013-09-06 日立建機株式会社 Steering device for vehicle
JPWO2013129090A1 (en) * 2012-02-29 2015-07-30 日立建機株式会社 Vehicle steering system
US9272729B2 (en) 2012-02-29 2016-03-01 Hitachi Construction Machinery Co., Ltd. Steering device for vehicle
DE112013001210B4 (en) * 2012-02-29 2017-01-19 Hitachi Construction Machinery Co., Ltd. Steering device for a vehicle

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