JP2568019Y2 - Front and rear four-wheel steering system for work vehicles - Google Patents
Front and rear four-wheel steering system for work vehiclesInfo
- Publication number
- JP2568019Y2 JP2568019Y2 JP1992010777U JP1077792U JP2568019Y2 JP 2568019 Y2 JP2568019 Y2 JP 2568019Y2 JP 1992010777 U JP1992010777 U JP 1992010777U JP 1077792 U JP1077792 U JP 1077792U JP 2568019 Y2 JP2568019 Y2 JP 2568019Y2
- Authority
- JP
- Japan
- Prior art keywords
- wheel
- wheel steering
- mode
- steering
- steering mode
- 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.)
- Expired - Fee Related
Links
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- Steering-Linkage Mechanisms And Four-Wheel Steering (AREA)
- Steering Control In Accordance With Driving Conditions (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本考案は薬剤を散布する防除車や
トラクタ等の作業車両用前後４輪操舵装置に関するもの
である。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front and rear four-wheel steering device for a working vehicle such as a control vehicle or a tractor for spraying a medicine.
【０００２】[0002]
【従来の技術】一般にこの種の作業車両用前後４輪操舵
装置は前輪又は後輪の２輪操舵を切り替え、更に前後輪
の同位相又は逆位相に切り替えるものが多いが、その切
り替えが機械式のものと油圧式のものとでは、油圧式の
ものは比較的構造上の制約が少ないが、機械式に比較し
てその切り替え制御が複雑である。また、特殊な作業車
両を除いて通常の作業車両は低速車であるために上記切
り替えを車速による自動切り替えにする必要がない。そ
こで特開平３−１４８３８４号公報に記載の４輪操舵装
置では、前後輪が中立（直進）位置にあるときにのみ前
２輪操舵モード、後２輪操舵モード、前後４輪同位相操
舵モード又は逆位相操舵モードに切り替えることができ
る。しかし断線等でモード切り替え用電磁弁への通電が
断たれると自動的に前２輪操舵になってしまうので、後
輪が中立位置以外であっても前２輪操舵になり、後輪が
中立でない状態でロックされてしまう欠点がある。2. Description of the Related Art Generally, a front-rear four-wheel steering system for a work vehicle of this type generally switches between front-wheel or rear-wheel two-wheel steering, and further switches between front and rear wheels in phase or opposite phases. Although the hydraulic type has relatively few structural restrictions, the switching control is more complicated than the mechanical type. In addition, since a normal work vehicle is a low-speed vehicle except for a special work vehicle, it is not necessary to perform the above-described switching automatically based on the vehicle speed. Therefore, in the four-wheel steering device described in Japanese Patent Application Laid-Open No. 3-148384, the front two-wheel steering mode, the rear two-wheel steering mode, the front-rear four-wheel same-phase steering mode or The mode can be switched to the anti-phase steering mode. However, if energization of the mode switching solenoid valve is interrupted due to disconnection or the like, front two-wheel steering is automatically performed. Therefore, even if the rear wheel is not in the neutral position, front two-wheel steering is performed, and the rear wheel is steered. There is a drawback that it is locked in a non-neutral state.
【０００３】[0003]
【考案が解決しようとする課題】本考案は、断線等によ
りモード切り替え用電磁弁への通電が断たれても直前の
状態を維持して操舵不能状態となることを防止すると共
に、配管内部の磨耗や傷等で前後４輪操舵モード状態で
前輪と後輪の同期にズレが発生してもこれを自動的に修
正させ、簡単な電気回路と油圧回路で従来の問題を解消
することができる作業車両用前後４輪操舵装置を提供す
ることを目的とする。SUMMARY OF THE INVENTION The present invention is intended to prevent a state in which steering is impossible by maintaining a state immediately before the power supply to a mode switching solenoid valve is cut off due to a disconnection or the like, and to prevent the inside of a pipe from being steered. Even if the front and rear wheels are out of synchronization in the front and rear four-wheel steering mode due to wear, scratches, etc., this can be corrected automatically, and the conventional problems can be solved with a simple electric circuit and hydraulic circuit. It is an object to provide a front-rear four-wheel steering device for a work vehicle.
【０００４】[0004]
【課題を解決するための手段】本考案に係る作業車両用
前後４輪操舵装置は、前２輪操舵モード、前後４輪操舵
モード及び後２輪操舵モードとを備え、前輪及び後輪の
中立位相でのみ前記モード切り替えが実行されると共
に、一旦２輪操舵モードに戻して前輪及び後輪を中立位
置に同期させたうえで前後４輪操舵に復帰させるため
に、前輪及び後輪用にそれぞれ独立した油圧シリンダ式
ステアリング装置と、該ステアリング装置の油圧配管路
中に前記操舵モード切り替えのための２個の少なくとも
２ポジションを有して非通電時にも通電時に選択された
所定の操舵モード切り替え位置が保持できるデテント形
電磁弁と、前後輪の中立位置を検出しその同期操作を前
記電磁弁に実行せしめる電気的制御装置とを設けた構成
を特徴とする。The front and rear four-wheel steering system for a work vehicle according to the present invention includes a front two-wheel steering mode, a front and rear four-wheel steering mode, and a rear two-wheel steering mode, and neutralizes front and rear wheels. The mode switching is executed only in the phase, and in order to return to the two-wheel steering mode, synchronize the front wheel and the rear wheel with the neutral position, and then return to the front and rear four-wheel steering, the front wheel and the rear wheel are respectively used. separate the hydraulic cylinder steering apparatus, selected during energization at two least 2 positions have a by-energized for the steering mode switching to the hydraulic piping path of the steering device
A detent-type solenoid valve capable of holding a predetermined steering mode switching position and an electrical control device for detecting a neutral position of the front and rear wheels and causing the solenoid valve to execute a synchronous operation thereof are provided.
【０００５】[0005]
【作用】従って、本考案に係る作業車両用前後４輪操舵
装置は、前輪及び後輪用にそれぞれ独立した油圧シリン
ダ式ステアリング装置を作動させ、電気的に制御して走
路状況に応じた操舵モード切り替えスイッチにより前２
輪操舵モード、前後４輪操舵モード、後２輪操舵モード
に変更でき、前後４輪操舵中の前輪と後輪の同期ズレを
簡単な制御装置で自動的に修正させ、任意の時点で前後
４輪操舵モードと２輪操舵モードとを切換えても、前後
４輪操舵モードにおける前後輪の同期ズレ、及び２輪操
舵モードにおける非操舵輪の非中立位置での車輪のロッ
クは発生せず、モード切り替え用電磁弁にデテントタイ
プのものを使用しているので、不慮の断線等で通電が断
たれてもそのまま直前のモードで操作続行が可能であ
る。Therefore, the front and rear four-wheel steering system for a work vehicle according to the present invention operates a hydraulic cylinder type steering system for front wheels and rear wheels, respectively, and electrically controls the steering mode according to the road condition. Front 2 by changeover switch
The mode can be changed to four-wheel steering mode, front-rear four-wheel steering mode, and rear two-wheel steering mode, and a simple control device automatically corrects synchronization deviation between the front and rear wheels during front-rear four-wheel steering. Even when the mode is switched between the wheel steering mode and the two-wheel steering mode, the synchronous shift of the front and rear wheels in the front and rear four-wheel steering mode and the lock of the wheels at the non-neutral position of the non-steered wheels in the two-wheel steering mode do not occur. Since the switching solenoid valve is of a detent type, the operation can be continued in the immediately preceding mode even if the power is cut off due to an unexpected disconnection or the like.
【０００６】[0006]
【実施例】本考案一実施例の作業車両用前後４輪操舵装
置の主要部を図１に示す。ハンドル１の操舵方向に応じ
た向きに操舵角に比例した量の高圧オイルをオービット
ロール（油圧操舵制御弁）２を介して油圧ポンプ３より
操舵モード切り替え用電磁弁ＳＶ１，ＳＶ２に供給す
る。この電磁弁ＳＶ１，ＳＶ２は２ポジション・デテン
ト形であり、前輪Ｆ及び後輪用として同じものを２個用
いている。本実施例の前記電磁弁ＳＶ１，ＳＶ２は、図
２に示す３種類の操舵モードＩ、II、III 、即ち、前輪
Ｆのみを操作する前２輪操舵モードＩ、前輪Ｆ及び後輪
Ｒを操作する前後逆相４輪操舵モードII、後輪Ｒのみを
操作する後２輪操舵モードIII のいずれかに切り替える
ために、それぞれのソレノイドＳＯＬ ａ１及びｂ１，
ＳＯＬ ａ２及びｂ２に通電して、前後２本の複動式油
圧シリンダ４，５を作動せしめる。図３はその切り替え
時における、前２輪操舵モードＩ、前後逆相４輪操舵モ
ードII、後２輪操舵モードIII における各電磁弁の状態
を示す。なお、前記２個の２ポジション・デテント形電
磁弁のうち、例えば前輪用のＳＶ１を図４の３ポジショ
ン・デテント形電磁ＳＶ３に置き代えると、前後４輪操
舵の同相・逆相の切換えが可能になる。図１における６
はキングピン、７はタイロッドアーム、８Ｌ及び８Ｒは
左右それぞれのタイロッド、９Ｌ及び９Ｒは左右それぞ
れのベルクランク、そして１０はセンターアーム、Ｓ１
は電源スイッチ、Ｓ２は操舵モード切り替えスイッチで
ある。FIG. 1 shows a main part of a front and rear four-wheel steering system for a working vehicle according to an embodiment of the present invention. An amount of high-pressure oil proportional to the steering angle in a direction corresponding to the steering direction of the steering wheel 1 is supplied from the hydraulic pump 3 to the steering mode switching solenoid valves SV1 and SV2 via the orbit roll (hydraulic steering control valve) 2. The solenoid valves SV1 and SV2 are of a two-position detent type, and two identical ones are used for the front wheel F and the rear wheel. The solenoid valves SV1 and SV2 of this embodiment operate three types of steering modes I, II, and III shown in FIG. 2, that is, a front two-wheel steering mode I in which only the front wheel F is operated, a front wheel F and a rear wheel R. Solenoids SOL a1 and b1 to switch between the front-rear four-wheel steering mode II and the rear two-wheel steering mode III in which only the rear wheel R is operated.
The SOLs a2 and b2 are energized to operate the front and rear two double-acting hydraulic cylinders 4,5. FIG. 3 shows the state of each solenoid valve in the front two-wheel steering mode I, the front-rear reversed four-wheel steering mode II, and the rear two-wheel steering mode III at the time of the switching. It should be noted that, for example, when the front-wheel SV1 of the two 2-position detent solenoid valves is replaced with the 3-position detent solenoid SV3 in FIG. 4, in-phase and out-of-phase switching of front and rear four-wheel steering is possible. become. 6 in FIG.
Is a kingpin, 7 is a tie rod arm, 8L and 8R are tie rods on each side, 9L and 9R are bell cranks on each side, and 10 is a center arm, S1
Is a power switch, and S2 is a steering mode switch.
【０００７】図５は本実施例の作業車両用前後４輪操舵
装置の操舵モード切り替えを制御する制御装置の図１に
示す制御盤Ｃの電気回路を示し、前後逆相４輪操舵モー
ドIIになっている。前後の油圧シリンダ４，５のソレノ
イドＳＯＬ ａ１，ＳＯＬａ２が共に通電状態で、表示
ランプＳＬ１，ＳＬ２が共に点灯し、油圧回路は図１の
前後逆相４輪操舵状態となる。この状態で断線等により
ソレノイドＳＯＬａ１，ＳＯＬ ａ２への通電が断たれ
ても、この状態は維持される。図５の前後逆相４輪操舵
モードIIでハンドル１を左右に連続して操舵する場合に
おいて、前輪Ｆと後輪Ｒの位相が正しく同期していれ
ば、前輪Ｆと後輪Ｒは同時に中立（直進）→非中立（変
向）→中立（直進）→・・・・と支障なく操舵される。
また、前輪操舵制御用リレーコイルＣＲ１及び後輪操舵
制御用リレーコイルＣＲ２の前後にそれぞれ接続されて
ベルクランク９の接離で作動する一回路二接点の前輪中
立検出用リミットスイッチＬＳ１及び後輪中立検出用リ
ミットＬＳ２の接点が同時に導通することがないので、
図５の非中立状態では、前輪操舵用ソレノイドＳＯＬａ
１と後輪操舵用ＳＯＬ ａ２とが常にＯＮであり、前輪
中立（ロック）用ソレノイドＳＯＬ ｂ１と後輪中立
（ロック）用ＳＯＬ ｂ２とが常にＯＦＦとなって逆相
前後４輪操舵状態が維持される。なお、リレー接点ＣＲ
１１は前輪操舵制御用リレーコイルＣＲ１の自己保持通
電用であり、リレー接点ＣＲ１１１はリレーコイルＣＲ
１への通電がＯＦＦの時に導通し、リレー接点ＣＲ２２
は後輪操舵制御用リレーコイルＣＲ２の自己保持用であ
り、リレー接点ＣＲ２２２はリレーコイルＣＲ２への通
電がＯＦＦの時に導通する。またリミット接点ＬＳ１１
は前輪中立検出用リミットスイッチＬＳ１が前輪中立位
置検出時に導通し、リミット接点ＬＳ１２はリミットス
イッチＬＳ１が前輪非中立時に導通し、リミット接点Ｌ
Ｓ２１は後輪中立検出用リミットＬＳ２が後輪中立位置
検出時に導通し、リミット接点ＬＳ２２はリミットスイ
ッチＬＳ２が後輪非中立時に導通する。FIG. 5 shows the electric circuit of the control panel C shown in FIG. 1 of the control device for controlling the switching of the steering mode of the front and rear four-wheel steering system for a work vehicle according to this embodiment. Has become. When the solenoids SOL a1 and SOLa2 of the front and rear hydraulic cylinders 4 and 5 are both energized, the display lamps SL1 and SL2 are both turned on, and the hydraulic circuit is in the front-rear four-wheel steering state of FIG. In this state, even if the power supply to the solenoids SOLa1 and SOL a2 is cut off due to disconnection or the like, this state is maintained. When the steering wheel 1 is continuously steered left and right in the front-rear four-wheel steering mode II shown in FIG. 5, if the phases of the front wheel F and the rear wheel R are correctly synchronized, the front wheel F and the rear wheel R are simultaneously neutralized. (Straight) → Non-Neutral (Diversion) → Neutral (Straight) →...
Further, a one-circuit, two-contact front-wheel neutral detection limit switch LS1 and a rear-wheel neutral, which are connected before and after the front-wheel steering control relay coil CR1 and the rear-wheel steering control relay coil CR2, respectively, and operate by the contact and separation of the bell crank 9. Since the contacts of the detection limit LS2 do not conduct at the same time,
In the non-neutral state shown in FIG. 5, the front wheel steering solenoid SOLa
1 and the rear wheel steering SOL a2 are always on, the front wheel neutral (locking) solenoid SOL b1 and the rear wheel neutral (locking) SOL b2 are always off, and the four-phase front-rear four-wheel steering is maintained. Is done. The relay contact CR
Numeral 11 is for self-holding energization of the front wheel steering control relay coil CR1, and relay contact CR111 is for the relay coil CR1.
1 is turned off when the power is turned off, and the relay contact CR22
Is for self-holding of the rear wheel steering control relay coil CR2, and the relay contact CR222 is conductive when the power supply to the relay coil CR2 is OFF. In addition, limit contact LS11
Is turned on when the front wheel neutral detection limit switch LS1 detects the front wheel neutral position, and the limit contact LS12 is turned on when the limit switch LS1 is non-neutral.
S21 is conducted when the rear wheel neutral detection limit LS2 detects the rear wheel neutral position, and the limit contact LS22 is conducted when the limit switch LS2 is not neutral.
【０００８】したがって、オービットロール２または油
圧シリンダ４，５等でのオイルリーク等による同期ズレ
が生じると、連続操舵中に前後の中立検出用リミットス
イッチＬＳ１，ＬＳ２のいずれか一方が先に中立位置と
なる。仮に、前輪側リミットスイッチＬＳ１が先に中立
になったとすると、後輪側リミットスイッチＬＳ２は非
中立なので、前輪操舵制御用リレーコイルＣＲ１がＯＮ
となる。従って前輪操舵用ソレノイドＳＯＬ ａ１がＯ
ＦＦ、後輪操舵用ソレノイドＳＯＬ ｂ２がＯＮとなっ
て後２輪操舵モードIII に自動的に切り替えられる。続
いて後輪側リミットスイッチＬＳ２が中立になれば前輪
操舵制御用リレーコイルＣＲ１がＯＦＦとなり、前後４
輪操舵モードIIに自動的に復帰する。また、後輪側リミ
ットスイッチＬＳ２が先に中立になると、これと逆に後
輪操舵制御用リレーコイルＣＲ２が動作する。Therefore, if a synchronous deviation occurs due to an oil leak or the like in the orbit roll 2 or the hydraulic cylinders 4, 5 or the like, one of the front and rear neutral detection limit switches LS1 and LS2 is first turned to the neutral position during continuous steering. Becomes If the front wheel side limit switch LS1 becomes neutral first, since the rear wheel side limit switch LS2 is non-neutral, the front wheel steering control relay coil CR1 is turned on.
Becomes Therefore, the front wheel steering solenoid SOL a1 is
FF, the rear-wheel steering solenoid SOL b2 is turned ON, and the mode is automatically switched to the rear-two-wheel steering mode III. Subsequently, when the rear wheel side limit switch LS2 becomes neutral, the front wheel steering control relay coil CR1 is turned off,
Automatically returns to wheel steering mode II. When the rear-wheel limit switch LS2 becomes neutral first, the rear-wheel steering control relay coil CR2 operates in reverse.
【０００９】図５に示すブザーＢＺ１，ＢＺ２は、前後
４輪操舵モードII時の前後輪同期修正が自動的に実施さ
れている間にオペレーターの注意を喚起するためのもの
で、ランプでも良い。また、モード切換えスイッチＳ２
は２回路連動スイッチで、「Ｉ」に切り替えると後輪側
リミットスイッチＬＳ２が中立になるまでは後輪操舵制
御用リレーコイルＣＲ２がＯＦＦのままなので、前後４
輪操舵モードIIを後輪中立まで維持した後で前２輪操舵
モードＩに自動的に切り替えられる。そして後２輪操舵
モードIII の時は、前輪側リミットスイッチＬＳ１が中
立になった時点で後２輪操舵モードIII の状態へ自動的
に切り替えられる。The buzzers BZ1 and BZ2 shown in FIG. 5 are for raising the operator's attention while the front and rear wheel synchronization correction in the front and rear four-wheel steering mode II is automatically performed, and may be lamps. Also, a mode changeover switch S2
Is a two-circuit interlock switch. When the switch is switched to "I", the rear wheel steering control relay coil CR2 remains OFF until the rear wheel limit switch LS2 becomes neutral.
After maintaining the wheel steering mode II until the rear wheel is neutral, the mode is automatically switched to the front two-wheel steering mode I. Then, in the rear two-wheel steering mode III, the state is automatically switched to the rear two-wheel steering mode III when the front wheel limit switch LS1 becomes neutral.
【００１０】[0010]
【考案の効果】以上の説明から明らかな通り、本考案の
構成によれば、前輪及び後輪用に独立した２系統の油圧
シリンダでステアリング装置を作動させるので設計にお
ける自由度が大きく、また電気的に制御しているのでセ
ンサー類の使用も容易であり、走路状況に応じた自動的
な操舵モードの変更制御が容易であり、前後４輪操舵中
に配管内部の磨耗や傷等で前輪と後輪の同期にズレが発
生しても、これをごく簡単な電気回路等の制御装置で自
動的に修正させることができ、任意の時点で前後４輪操
舵モードと２輪操舵モードとを切換えても、前後４輪操
舵モードにおける同期ズレ及び２輪操舵モードにおける
非操舵輪の非中立状態での車輪のロック現象は発生せ
ず、更には電磁弁にデテントタイプのものを使用してい
るので、不慮の断線等で通電が断たれてもそのまま直前
のモードで操作が可能である。As is apparent from the above description, according to the structure of the present invention, the steering device is operated by two independent hydraulic cylinders for the front wheel and the rear wheel, so that the degree of freedom in the design is large and the electric power is increased. It is easy to use sensors because it is controlled, and it is easy to automatically control the change of the steering mode according to the road condition. Even if there is a deviation in the synchronization of the rear wheels, this can be automatically corrected by a very simple control circuit such as an electric circuit, and the mode can be switched between the front and rear four-wheel steering mode and the two-wheel steering mode at any time. However, there is no synchronous displacement in the front-rear four-wheel steering mode and no locking phenomenon of the wheels in the non-neutral state of the non-steered wheels in the two-wheel steering mode, and furthermore, since a detent type solenoid valve is used. Accidental disconnection In even energization is cut off are possible as operated in the previous mode.
【図１】本考案の一実施例である作業車両用前後４輪操
舵装置を示す簡略平面図。FIG. 1 is a simplified plan view showing a front and rear four-wheel steering device for a work vehicle according to an embodiment of the present invention.
【図２】各操舵モードを示す図。FIG. 2 is a diagram showing each steering mode.
【図３】電磁弁と操舵モードとの関係を示す図。FIG. 3 is a diagram showing a relationship between a solenoid valve and a steering mode.
【図４】３ポジション・デテント形電磁弁を示す図。FIG. 4 is a view showing a three-position detent type solenoid valve.
【図５】本考案の一実施例である作業車両用前後４輪操
舵装置の電気回路図。FIG. 5 is an electric circuit diagram of the front and rear four-wheel steering device for a work vehicle according to one embodiment of the present invention.
１ ハンドル ２ オービットロール ４ 前輪操舵用油圧シリンダー ５ 後輪操舵用油圧シリンダー Ｆ 前輪 Ｒ 後輪 ＳＶ１ 前輪操舵モード切り替え用電磁弁 ＳＶ２ 後輪操舵モード切り替え用電磁弁 ＳＯＬ ａ１ ソレノイド ＳＯＬ ａ２ ソレノイド ＳＯＬ ｂ１ ソレノイド ＳＯＬ ｂ２ ソレノイド ＬＳ１ 前輪中立検出用リミットスイッチ ＬＳ２ 後輪中立検出用リミットスイッチ REFERENCE SIGNS LIST 1 handle 2 orbit roll 4 front wheel steering hydraulic cylinder 5 rear wheel steering hydraulic cylinder F front wheel R rear wheel SV1 front wheel steering mode switching solenoid valve SV2 rear wheel steering mode switching solenoid valve SOL a1 solenoid SOL a2 solenoid SOL b1 solenoid SOL b2 Solenoid LS1 Front wheel neutral detection limit switch LS2 Rear wheel neutral detection limit switch
Claims (2)
モード（ＩＩ）及び後２輪操舵モード（ＩＩＩ）とを備
え、前輪（Ｆ）及び後輪（Ｒ）の中立位相でのみ前記モ
ード切り替えが実行されると共に、一旦２輪操舵モード
に戻して前輪及び後輪を中立位置に同期させたうえで前
後４輪操舵に復帰させるために、前輪及び後輪用にそれ
ぞれ独立した油圧シリンダ式ステアリング装置（４，
５，６，７，８Ｌ，８Ｒ，９Ｌ，９Ｒ，１０）と、該ス
テアリング装置の油圧配管路中に前記操舵モード切り替
えのための２個のそれぞれ少なくとも２ポジションを有
して非通電時にも通電時に選択された所定の操舵モード
切り替え位置が保持できるデテント形電磁弁（ＳＶ１，
ＳＶ２）と、前後輪の中立位置を検出しその同期操作を
前記電磁弁に実行せしめる電気的制御装置（Ｃ，ＬＳ
１，ＬＳ２）とを設けたことを特徴とする作業車両用前
後４輪操舵装置。1. A front two-wheel steering mode (I), a front-rear four-wheel steering mode (II), and a rear two-wheel steering mode (III), and only in a neutral phase of the front wheels (F) and the rear wheels (R). In addition to the mode switching being performed, the hydraulic pressures for the front wheel and the rear wheel are independently set to return to the two-wheel steering mode, synchronize the front wheel and the rear wheel with the neutral position, and then return to the front and rear four-wheel steering. Cylinder steering device (4
5, 6, 7, 8L, 8R, 9L, 9R, 10) and at least two positions each for switching the steering mode in the hydraulic piping of the steering device.
The detent solenoid valve (SV1, SV1) can hold the predetermined steering mode switching position selected at the time of energization even when the power is not energized .
SV2) and an electric control device (C, LS) for detecting the neutral position of the front and rear wheels and causing the solenoid valve to execute a synchronous operation thereof.
1, LS2) are provided.
ポジションを有することを特徴とする請求項１の作業車
両用前後４輪操舵装置。2. At least one of said two solenoid valves is 3
The front and rear four-wheel steering device for a work vehicle according to claim 1, wherein the steering device has a position.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1992010777U JP2568019Y2 (en) | 1992-03-04 | 1992-03-04 | Front and rear four-wheel steering system for work vehicles |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1992010777U JP2568019Y2 (en) | 1992-03-04 | 1992-03-04 | Front and rear four-wheel steering system for work vehicles |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0572656U JPH0572656U (en) | 1993-10-05 |
| JP2568019Y2 true JP2568019Y2 (en) | 1998-04-08 |
Family
ID=11759768
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1992010777U Expired - Fee Related JP2568019Y2 (en) | 1992-03-04 | 1992-03-04 | Front and rear four-wheel steering system for work vehicles |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2568019Y2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4843765B2 (en) * | 2001-06-22 | 2011-12-21 | 株式会社タダノ | Hydraulic suspension device for traveling crane |
| JP2014201291A (en) * | 2013-04-09 | 2014-10-27 | アイシン精機株式会社 | Vehicle behavior control device and vehicle behavior control system |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63232064A (en) * | 1987-03-19 | 1988-09-28 | Komatsu Ltd | Two-system hydraulic brake device for vehicle |
| JP2888442B2 (en) * | 1989-10-31 | 1999-05-10 | 井関農機株式会社 | Powered vehicle four-wheel steering system |
-
1992
- 1992-03-04 JP JP1992010777U patent/JP2568019Y2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0572656U (en) | 1993-10-05 |
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| LAPS | Cancellation because of no payment of annual fees |