JPH0525989Y2 - - Google Patents
Info
- Publication number
- JPH0525989Y2 JPH0525989Y2 JP1986105639U JP10563986U JPH0525989Y2 JP H0525989 Y2 JPH0525989 Y2 JP H0525989Y2 JP 1986105639 U JP1986105639 U JP 1986105639U JP 10563986 U JP10563986 U JP 10563986U JP H0525989 Y2 JPH0525989 Y2 JP H0525989Y2
- Authority
- JP
- Japan
- Prior art keywords
- steering
- steering angle
- wheel steering
- mode
- 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.)
- Expired - Lifetime
Links
- 238000001514 detection method Methods 0.000 claims description 22
- 238000010586 diagram Methods 0.000 description 12
- 101100168642 Arabidopsis thaliana CRN gene Proteins 0.000 description 4
- 101100045632 Arabidopsis thaliana TCX2 gene Proteins 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 101150103732 sol2 gene Proteins 0.000 description 4
- 101100045633 Arabidopsis thaliana TCX3 gene Proteins 0.000 description 2
- 101150037491 SOL1 gene Proteins 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000010001 crabbing Methods 0.000 description 1
- 238000009429 electrical wiring Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 230000035807 sensation Effects 0.000 description 1
- 210000002027 skeletal muscle Anatomy 0.000 description 1
Landscapes
- Steering-Linkage Mechanisms And Four-Wheel Steering (AREA)
Description
【考案の詳細な説明】
［産業上の利用分野］
本考案は、ステアリングホイールに連結された
ステアリングギヤボツクスに連動するステアリン
グユニツト、ポンプユニツト、後輪アクチユエー
タおよびモード切換バルブを油圧配管で接続し、
後輪を前輪と逆位相に操舵する逆位相４輪操舵モ
ード、後輪を前輪と同位相に操舵する同位相操舵
モードおよび後輪を非操舵とする２輪操舵モード
の走行を選択的に行うことができる４輪操舵車に
関し、特に同位相４輪操舵モード走行時に若干の
旋回運動の発生を防止する４輪操舵車に関する。[Detailed description of the invention] [Industrial application field] This invention connects a steering unit, a pump unit, a rear wheel actuator, and a mode switching valve that are linked to a steering gear box connected to a steering wheel using hydraulic piping.
The vehicle selectively operates in an anti-phase four-wheel steering mode in which the rear wheels are steered in the opposite phase to the front wheels, an in-phase steering mode in which the rear wheels are steered in the same phase as the front wheels, and a two-wheel steering mode in which the rear wheels are not steered. The present invention relates to a four-wheel steered vehicle that can be operated, and particularly relates to a four-wheel steered vehicle that prevents the occurrence of slight turning motion when traveling in the same-phase four-wheel steering mode.
［従来技術］
４輪操舵車は知られており（例えば特開昭59−
100062号公報）、その一例を第６図ないし第８図
について説明する。[Prior art] Four-wheel steering vehicles are known (for example, Japanese Patent Application Laid-Open No. 1983-1999).
100062), an example of which will be explained with reference to FIGS. 6 to 8.
第６図において、ステアリングホイール１には
ステアリングギヤボツクス２が連結され、そのス
テアリングギヤボツクスに連結されたピツトマン
アーム３は前輪のステアリングアーム４に連結さ
れていることは公知のフロントステアリング装置
と同じである。 In FIG. 6, a steering gear box 2 is connected to the steering wheel 1, and a pitman arm 3 connected to the steering gear box is connected to a steering arm 4 of the front wheel, which is the same as a known front steering device. .
そのステアリングギヤボツクス２にはベルト５
を介してリアステアリング用のステアリングユニ
ツト６が連結されている。このステアリングユニ
ツト６は油圧配管（以下配管という）L1により
エンジンに駆動されるポンプユニツト１３を介
し、また配管L2を介してそれぞれリザーブタン
ク１４に接続されており、また配管L3，L4によ
り後車軸RAに固設された後輪アクチユエータ
（図示の例では複動型の油圧シリンダ）１５に接
続されている。そして、ステアリングユニツト６
はステアリングギヤボツクス２に連動して切換わ
り、後輪アクチユエータ１５に油圧を給排するよ
うになつている。 Belt 5 is attached to the steering gear box 2.
A steering unit 6 for rear steering is connected thereto. This steering unit 6 is connected to a reserve tank 14 via a pump unit 13 driven by the engine by a hydraulic pipe (hereinafter referred to as pipe) L1 and via a pipe L2 , and is connected to a reserve tank 14 via pipes L3 and L4 . is connected to a rear wheel actuator (in the illustrated example, a double-acting hydraulic cylinder) 15 that is fixed to the rear axle RA. And steering unit 6
is switched in conjunction with the steering gear box 2 to supply and discharge hydraulic pressure to the rear wheel actuator 15.
前記配管L3，L4の途中には、モード切換バル
ブ１６が介装され、そのモード切換バルブ１６は
モード切換スイツチ（第８図）１７により切換わ
り後輪アクチユエータ１５への油の流れを切換え
て、後輪を前輪と逆位相に操舵する逆位相４輪操
舵モード（以下4WS・No.１モードという）、後輪
を前輪と同位相に操舵する同位相４輪操舵モード
いわゆるカニ走行モード（以下4WS・No.２モー
ドという）および後輪を非操舵とする２輪操舵モ
ード（以下2WSモードという）の３操舵モード
の切換えを行うようになつている。 A mode switching valve 16 is interposed in the middle of the pipes L 3 and L 4 , and the mode switching valve 16 is switched by a mode switching switch (FIG. 8) 17 to switch the flow of oil to the rear wheel actuator 15. There is an anti-phase 4-wheel steering mode (hereinafter referred to as 4WS No. 1 mode) in which the rear wheels are steered in the opposite phase to the front wheels, and an in-phase 4-wheel steering mode in which the rear wheels are steered in the same phase as the front wheels, so-called crab driving mode ( It is designed to switch between three steering modes: a two-wheel steering mode (hereinafter referred to as 2WS mode) in which the rear wheels are not steered (hereinafter referred to as 4WS No. 2 mode) and a two-wheel steering mode in which the rear wheels are not steered.
第７図に示す油圧回路図において、ステアリン
グユニツト６には、公知技術による６ポート３位
置の切換バルブ７、可逆式の油圧モータ８および
メカニカルリンク９が設けられ、ステアリングホ
イール１を例えば左切りとすると、切換バルブ７
は位置に切換わり配管L3を配管L1すなわちポ
ンプユニツト１３側に接続するとともに配管L4
を配管L2すなわちリザーブタンク１４側に接続
し、また油圧モータ８によりメカニカルリンク９
を左方に回動して位置へ切換える方向に付勢す
るサーボ機能をはたすようになつている。なお、
１０はチエツクバルブ、１１はリリーフバルブ、
１２はフイルタである。 In the hydraulic circuit diagram shown in FIG. 7, the steering unit 6 is provided with a six-port three-position switching valve 7, a reversible hydraulic motor 8, and a mechanical link 9 according to known technology, and the steering wheel 1 can be rotated, for example, to the left. Then, the switching valve 7
is switched to the position, connecting pipe L3 to pipe L1 , that is, the pump unit 13 side, and connecting pipe L4 to the pump unit 13 side.
is connected to the pipe L 2 , that is, the reserve tank 14 side, and the mechanical link 9 is connected by the hydraulic motor 8.
It has a servo function that rotates it to the left and biases it in the direction of switching the position. In addition,
10 is a check valve, 11 is a relief valve,
12 is a filter.
モード切換バルブ１６は、４ポート３位置の電
磁切換バルブであつて、電磁ソレノイドSOL１
の移動時にパラレル接続の位置に切換つて
4WS・No.１モード、電磁ソレノイドSOL２の作
動時にクロス接続の位置に切換つて4WS・No.
２モード、両ソレノイドが非差動時にリターン
（配管L3を配管L4に接続する）位置にあつて2WS
モードにそれぞれ車両の走行モードを切換るよう
になつている。 The mode switching valve 16 is a 4-port, 3-position electromagnetic switching valve with an electromagnetic solenoid SOL1.
Switch to the parallel connection position when moving the
4WS・No.1 mode, when the electromagnetic solenoid SOL2 is activated, it switches to the cross connection position and 4WS・No.
2 mode, 2WS when both solenoids are in the return position (connecting pipe L 3 to pipe L 4 ) when non-differential.
The driving mode of the vehicle can be changed depending on the mode.
第８図に示す電気回路図において、モード切換
スイツチ１７は、電源とモード切換バルブ１６の
SOL１，SOL２とを接続する並列な電気配線
（以下電線という）l1，l2にそれぞれ介装された
4WS・No.１モード用のスイツチ１７ａ、4WS・
No.２モード用のスイツチ１７ｂおよび電線l3によ
りスイツチ１７ａ，１７ｂと並列に設けられた
2WSモード用のスイツチ１７ｃからなつており、
電線l1ないしl3には、閉路時に点灯されるパイロ
ツトランプ１８ａないし１８ｃがそれぞれ設けら
れている。 In the electrical circuit diagram shown in FIG.
Interposed in parallel electrical wiring (hereinafter referred to as electric wire) l 1 and l 2 connecting SOL1 and SOL2, respectively.
Switch 17a for 4WS・No.1 mode, 4WS・
No. 2 mode switch 17b and electric wire L 3 were installed in parallel with switches 17a and 17b.
Consists of switch 17c for 2WS mode,
The electric wires l1 to l3 are respectively provided with pilot lamps 18a to 18c that are lit when the circuit is closed.
このような構成において、モード切換スイツチ
１７によりモード切換バルブ１６を切換えてステ
アリングホイール１の操作に応じ、4WS、No.１
モード4WS・No.２モードおよび2WSモードを選
択的に行うようになつている。 In such a configuration, the mode switching valve 16 is switched by the mode switching switch 17 to select 4WS, No. 1, etc. according to the operation of the steering wheel 1.
Mode 4WS/No.2 mode and 2WS mode are selectively performed.
ところで、この４輪操舵車において、後輪の操
舵機構は駆動系の制約を受けて第３図に破線で示
すように、後輪操舵角θの最大値θrmaxは前輪操
舵角θfの最大値θfmaxより小さくなつている。し
たがつて、後輪操舵角θrを両最大値の交点Ｐと原
点Ｏとを結ぶ線が直線となるように前輪操舵角θf
に比例させている。したがつて、4WS・No.２モ
ードで走行時は、前後輪の操舵角が等しいのが好
ましいのに対して前後輪の操舵角θf，θr間に差異
が生じ、その結果、4WS・No.２モード走行いわ
ゆるカニ走行でありながらカニ走行方向に若干旋
回運動が生ずるという不具合がある。 By the way, in this four-wheel steering vehicle, the rear wheel steering mechanism is limited by the drive system, and as shown by the broken line in FIG. 3, the maximum value θrmax of the rear wheel steering angle θ is equal to the maximum value θfmax of the front wheel steering angle θf. It's getting smaller. Therefore, the front wheel steering angle θf is adjusted so that the line connecting the intersection point P of both maximum values and the origin O becomes a straight line.
It is proportional to. Therefore, when driving in 4WS/No. 2 mode, it is preferable that the steering angles of the front and rear wheels be the same, but a difference occurs between the steering angles θf and θr of the front and rear wheels, and as a result, 4WS/No. Although the two-mode running is so-called crab running, there is a problem in that a slight turning movement occurs in the crab running direction.
前輪および後輪操舵に際して前後輪の操舵角を
同じにする技術は実開昭50−17137号公報に記載
されている。しかしながら、かかる公知技術では
同位相モードすなわちカニ走行時はとにかく、逆
位相モードにおいて操舵角が同じであるので、い
わゆる尻振りが大きくなり、運転感覚上、2WS
モード時の操舵と著しく相違し、危険を伴うこと
になる。 A technique for making the steering angles of the front and rear wheels the same when steering the front and rear wheels is described in Japanese Utility Model Application Publication No. 17137/1983. However, in this known technology, since the steering angle is the same in the in-phase mode, that is, when crabbing, and in the anti-phase mode, the so-called tail swing becomes large, and the 2WS
This is significantly different from steering in mode, and is dangerous.
［解決する課題］
したがつて本考案の目的は、逆位相４輪操舵モ
ード走行時には、２輪操舵時とあまり違いかな
く、かつ充分に小さい旋回半径で回転でき、同位
相４輪操舵モード時に旋回運動を防止できる４輪
操舵車を提供するにある。[Problems to be Solved] Therefore, the purpose of the present invention is to be able to rotate with a turning radius that is not much different from two-wheel steering when running in anti-phase four-wheel steering mode, and with a sufficiently small turning radius; To provide a four-wheel steering vehicle capable of preventing turning movement.
［課題を解決する手段］
本考案によれば、ステアリングホイールに連結
されたステアリングギヤボツクスに連動するステ
アリングユニツト、ポンプユニツト、後輪アクチ
ユエータおよびモード切換バルブを油圧配管で接
続し、後輪を前輪と逆位相に操舵する逆位相４輪
操舵モード、後輪を前輪と同位相に操舵する同位
相操舵モードおよび後輪を非操舵とする２輪操舵
モードの走行を選択的に行い、そして前輪操舵角
と後輪操舵角とが異なつている４輪操舵車におい
て、ステアリングギヤボツクスに枢着されたピツ
トマンアームに前輪操舵角が後輪操舵角最大値に
達したことを検出する操舵角検出スイツチと、前
後輪の操舵角を等しくする手段と、同位相４輪操
舵モード走行時に前記操舵角検出スイツチの検出
信号に基づきモード切換バルブを切換制御する制
御回路を設け、該制御回路は操舵角検出スイツチ
の検出信号に基づき前輪操舵角が後輪操舵角最大
値に達するまではモード切換バルブを同位相４輪
操舵モード位置に切換え、前輪操舵角が後輪操舵
角最大値に達した後にモード切換バルブをリター
ン位置にする機能を有し、前記前後輪の操舵角を
等しくする手段は、ステアリングギヤボツクスと
ステアリングユニツトを連結するベルトのステア
リングユニツト側プーリに小径のプーリを有して
いる。[Means for solving the problem] According to the present invention, a steering unit, a pump unit, a rear wheel actuator, and a mode switching valve that are linked to a steering gear box connected to a steering wheel are connected by hydraulic piping, and the rear wheels are connected to the front wheels. The system selectively operates in an anti-phase four-wheel steering mode in which the rear wheels are steered in opposite phases, an in-phase steering mode in which the rear wheels are steered in the same phase as the front wheels, and a two-wheel steering mode in which the rear wheels are not steered. In a four-wheel steering vehicle in which the front and rear wheel steering angles are different, a steering angle detection switch is provided on a pitman arm pivotally connected to the steering gear box to detect when the front wheel steering angle has reached the maximum rear wheel steering angle. A means for equalizing the steering angles of the wheels, and a control circuit for switching and controlling the mode switching valve based on the detection signal of the steering angle detection switch when traveling in the same-phase four-wheel steering mode, and the control circuit controls the detection of the steering angle detection switch. Based on the signal, the mode switching valve is switched to the same-phase 4-wheel steering mode position until the front wheel steering angle reaches the maximum rear wheel steering angle, and the mode switching valve is returned after the front wheel steering angle reaches the maximum rear wheel steering angle. The means for equalizing the steering angles of the front and rear wheels has a small diameter pulley on the steering unit side pulley of the belt connecting the steering gear box and the steering unit.
［作用効果の説明］
したがつて、逆位相４輪操舵時には従来と同様
に前輪操舵角より後輪操舵角の方が小さく、いわ
ゆる尻振りの程度も小さく、２輪駆動の運転感覚
とあまり差異のない安全な操舵走行を行うことが
できる。[Explanation of effects] Therefore, during anti-phase four-wheel steering, the rear wheel steering angle is smaller than the front wheel steering angle as before, and the degree of so-called tail swing is also small, so there is not much difference from the driving sensation of two-wheel drive. It is possible to perform safe steering operation without any problems.
そして、同位相４輪操舵モードで走行する際に
は、前輪操舵角が後輪操舵角の最大値に達するま
では、後輪操舵角は前後輪の操舵角を等しくする
手段によつて、等しい操舵角で操舵される。そし
て前輪操舵角が後輪操舵角最大値に達した後は、
操舵角検出スイツチはモード切換バルブをリター
ン位置にするので、後輪操舵角は最大値にホール
ドされて前輪操舵角が増大する。 When driving in the same-phase four-wheel steering mode, the rear wheel steering angle is equalized by means of equalizing the front and rear wheel steering angles until the front wheel steering angle reaches the maximum value of the rear wheel steering angle. It is steered by the steering angle. After the front wheel steering angle reaches the maximum rear wheel steering angle,
Since the steering angle detection switch sets the mode switching valve to the return position, the rear wheel steering angle is held at the maximum value and the front wheel steering angle increases.
このように本考案によれば、逆位相４輪操舵時
は従来と同様に安全な操舵ができ、同位相４輪操
舵時は後輪操舵角最大値までは前後輪が同じ角度
で操舵されるので、いわゆるカニ走行において、
旋回が生じない。前輪操舵角が後輪操舵角の最大
値以上に操舵されると、後輪操舵角は最大値にホ
ールドされるので、若干の旋回運動は生ずるが、
操舵角が大きい場合は、運転者は慎重に運転し、
若干の旋回運動が生じても問題がない。 As described above, according to the present invention, when steering four wheels in opposite phase, the steering can be performed safely as before, and when steering four wheels in same phase, the front and rear wheels are steered at the same angle until the maximum rear wheel steering angle is reached. Therefore, in the so-called crab run,
No turning occurs. When the front wheel steering angle is steered to a value greater than or equal to the maximum value of the rear wheel steering angle, the rear wheel steering angle is held at the maximum value, so some turning movement occurs, but
If the steering angle is large, the driver should drive carefully and
There is no problem even if a slight turning movement occurs.
［実施例］
以下図面を参照して本考案の実施例を説明す
る。[Examples] Examples of the present invention will be described below with reference to the drawings.
これら図面において、第６図ないし第８図に対
応する部分については、同じ符号を付して重複説
明を省略する。 In these drawings, parts corresponding to FIGS. 6 to 8 are designated by the same reference numerals, and redundant explanation will be omitted.
第１図において、ピツトマンアーム３には、ピ
ツトマンアーム３の回動角度すなわち前輪の操舵
角θfを検出する操舵角検出スイツチ２０が設けら
れている。この検出スイツチ２０は第２図に示す
ように、ピツトマンアーム３のボス部３ａに中立
位置から左右に中心角θ1づつ突設されたカム３ｂ
にスイツチのローラ２０ａが乗り上げているとき
に閉じるようになつており、この中心角θ1は第３
図において、前輪操舵角が後輪操舵角θrmaxに等
しくなる点Ｑに対応している。したがつて、直線
OQ上では前輪操舵角θfと後輪操舵角θrの比は
１：１である。そして操舵角検出スイツチ２０
は、前輪操舵角が＋θ1°〜−θ1°の間でONとな
る。 In FIG. 1, the pitman arm 3 is provided with a steering angle detection switch 20 for detecting the rotation angle of the pitman arm 3, that is, the steering angle θf of the front wheels. As shown in FIG. 2, this detection switch 20 has a cam 3b protruding from the boss portion 3a of the Pittman arm 3 by a center angle θ 1 from the neutral position to the left and right.
It is designed to close when the roller 20a of the switch is riding on the switch, and this central angle θ 1 is the third
In the figure, this corresponds to a point Q where the front wheel steering angle becomes equal to the rear wheel steering angle θrmax. Therefore, straight line
On the OQ, the ratio between the front wheel steering angle θf and the rear wheel steering angle θr is 1:1. And steering angle detection switch 20
is ON when the front wheel steering angle is between +θ 1 ° and −θ 1 °.
第４図において、ベルト５のステアリングユニ
ツト６側のプーリ５ａの外径は第７図に示すもの
より小径に形成されていて、ハンドルホイール１
の同一回転角度で後輪の操舵角度θrを大きくし
て、操舵角検出スイツチ２０のON時に前輪操舵
角θfに等しくする手段となつている。 In FIG. 4, the outer diameter of the pulley 5a of the belt 5 on the steering unit 6 side is formed to be smaller than that shown in FIG.
The steering angle θr of the rear wheels is increased at the same rotation angle of , and the steering angle θr of the rear wheels is made equal to the front wheel steering angle θf when the steering angle detection switch 20 is turned on.
第５図に示す電気回路図において、電源には電
線l4，l5により操舵角検出スイツチ２０、リレー
２１が並列に接続されている。そして、電線l4は
リレー２１のコイルに接続され、電線l5は電線l2，
l1に介装されたリレー２２，２３のコイルに直列
に接続されている。これら操舵角検出スイツチ２
０、リレー２１ないし２３、電磁ソレノイド
SOL１，２およびこれらを接続する電線により
全体をＡで示す制御回路が構成される。 In the electrical circuit diagram shown in FIG. 5, a steering angle detection switch 20 and a relay 21 are connected in parallel to the power source by electric wires l4 and l5 . Then, the electric wire l 4 is connected to the coil of the relay 21, the electric wire l 5 is connected to the electric wire l 2 ,
It is connected in series to the coils of relays 22 and 23 installed in l1 . These steering angle detection switches 2
0, Relays 21 to 23, Electromagnetic solenoid
The entire control circuit indicated by A is constituted by the SOLs 1 and 2 and the electric wires connecting them.
次に作用について説明する。 Next, the effect will be explained.
4WS・No.２モード走行に際し、モード切換ス
イツチ１７のスイツチ１７ｂを閉じる。その状態
ではローラ２０ａがカム３ｂに乗り上げていて操
舵角検出スイツチ２０は閉じている。したがつて
リレー２２が閉じ、電磁ソレノイドSOL２が作
動してモード切換スイツチ１６は位置に切換わ
る。そのため、例えばステアリングホイール１を
後輪操舵角最大値θrmaxより小さく例えば10度だ
け右切りすると、ステアリングユニツト６の切換
バルブ７は位置に切換わり、その結果、ポンプ
ユニツト１３からの圧油は配管L1を通つて油圧
モータ８をまわし、油圧モータ８からの吐出油が
切換バルブ７を介して配管L4に流れ、モード切
換バルブ１６が位置に切換わつているので油は
矢印と反対方向に流れて配管L4ｂを通つて後輪
アクチユエータ１５の右側圧力室１５ｂに流れ、
後輪を右側に前輪操舵角10度に等しい操舵角10度
だけ操舵し、カニ走行が行われる（直線Ｏ→Ｑ）。
そして左側の圧力室１５ａの油は位置にあるモ
ード切換バルブ１６を矢印と反対方向に流れ、配
管L3から位置にある切換バルブ７を通つて配
管L2に流れてドレンされる。さらにステアリン
グホイール１を右切りして、前輪操舵角θfが後輪
操舵角最大値θrmaxになつた時点、すなわち前輪
操舵角がθ1になると、ローラ２０ａがカム２０ｂ
から外れ、操舵角検出スイツチ２０はOFFとな
る。したがつて、リレー２１が消勢し、これによ
つてリレー２２が消勢し、スイツチ１７ｂが閉じ
ていても電磁ソレノイドSOL２への電流は断た
れ、モード切換バルブ１６は位置に戻る。この
ため、それ以降は前輪操舵角θfが増して、最大値
θfmaxに至つても（直線Ｏ→θ1→θfmax）、後輪
操舵角は最大値θrmaxにホールドされる（第３図
の直線Ｑ→Ｐ）。 When traveling in the 4WS/No. 2 mode, close the switch 17b of the mode changeover switch 17. In this state, the roller 20a rides on the cam 3b and the steering angle detection switch 20 is closed. Therefore, the relay 22 is closed, the electromagnetic solenoid SOL2 is operated, and the mode changeover switch 16 is switched to the position. Therefore, for example, when the steering wheel 1 is turned to the right by 10 degrees to a value smaller than the maximum rear wheel steering angle θrmax, the switching valve 7 of the steering unit 6 is switched to the position, and as a result, the pressure oil from the pump unit 13 is transferred to the piping L. The oil discharged from the hydraulic motor 8 flows through the switching valve 7 to the pipe L 4 , and since the mode switching valve 16 has been switched to the position, the oil flows in the opposite direction to the arrow . and flows through the pipe L4b to the right pressure chamber 15b of the rear wheel actuator 15,
The rear wheels are steered to the right by a steering angle of 10 degrees, which is equal to the front wheel steering angle of 10 degrees, and crab running is performed (straight line O→Q).
The oil in the left pressure chamber 15a flows in the direction opposite to the arrow through the mode switching valve 16 located at the position, flows from the pipe L3 through the switching valve 7 located at the position, flows to the pipe L2 , and is drained. Furthermore, when the steering wheel 1 is turned to the right and the front wheel steering angle θf reaches the maximum value θrmax of the rear wheel steering angle, that is, when the front wheel steering angle reaches θ1 , the roller 20a is turned to the cam 20b.
The steering angle detection switch 20 is turned OFF. Therefore, relay 21 is deenergized, which in turn deenergizes relay 22, and even if switch 17b is closed, the current to electromagnetic solenoid SOL2 is cut off, and mode switching valve 16 returns to its position. Therefore, even if the front wheel steering angle θf increases after that and reaches the maximum value θfmax (straight line O → θ 1 → θfmax), the rear wheel steering angle is held at the maximum value θrmax (straight line Q in Figure 3). →P).
したがつて、前輪操舵角が後輪操舵角最大値ま
では前輪操舵角θfと後輪操舵角θrとの間には差が
なく、旋回運動の発生が防止され、それ以上では
若干の旋回運動が発生するが、操舵角が大な場合
は運転者は慎重に運転するので、危険は生ぜず、
また通常後輪操舵角の最大値は前輪のそれより小
さく設計されているので、実際上、好ましい操舵
ができる。 Therefore, until the front wheel steering angle reaches the maximum value of the rear wheel steering angle, there is no difference between the front wheel steering angle θf and the rear wheel steering angle θr, and turning movement is prevented from occurring, and beyond that, there is a slight turning movement. However, if the steering angle is large, the driver drives carefully, so there is no danger.
Furthermore, since the maximum value of the rear wheel steering angle is normally designed to be smaller than that of the front wheels, it is possible to achieve favorable steering in practice.
なお、4WS・No.１モード走行に際し、スイツ
チ１７ａを閉じた場合も、上述と同じように、前
後輪の操舵角間の差はなく、従来より旋回半径が
小さくなることは自明である。 Note that even when the switch 17a is closed when driving in the 4WS/No. 1 mode, it is obvious that there is no difference between the steering angles of the front and rear wheels, and the turning radius is smaller than before, as described above.
［考案の効果］
以上の如く本考案によれば下記のすぐれた効果
を奏する。[Effects of the invention] As described above, the present invention provides the following excellent effects.
(i) 逆位相４輪操舵モード走行時は従来通りの尻
振りの少ない運転ができる。(i) When driving in anti-phase four-wheel steering mode, the vehicle can be driven with less wobbling as before.
(ii) 同位相４輪操舵モード走行時には、後輪操舵
角最大値までは前後輪が同じ角度で操舵され、
その間に旋回が生じない。(ii) When driving in same-phase four-wheel steering mode, the front and rear wheels are steered at the same angle until the rear wheel steering angle reaches the maximum value.
No turning occurs during that time.
(iii) 後輪操舵角最大値以上の角で前輪が操舵され
ると、後輪はその最大値にホールドされ、若干
の旋回は生ずるが、問題はなく、通常の後輪操
舵角が前輪操舵角より小さい車両に対して好適
なカニ走行ができる。(iii) When the front wheels are steered at an angle greater than the maximum rear wheel steering angle, the rear wheels will be held at the maximum value and a slight turning will occur, but there is no problem and the normal rear wheel steering angle will be the same as the front wheel steering angle. A suitable crab run is possible for vehicles smaller than the angle.
第１図は本考案の一実施例を示す全体構成図、
第２図は操舵角検出スイツチの説明図、第３図は
前後輪の操舵角特性図と操舵角検出スイツチの動
作特性図、第４図は油圧回路図、第５図は電気回
路図、第６図は従来の４輪操舵車を示す全体構成
図、第７図は油圧回路図、第８図は電気回路図で
ある。
Ａ……制御回路、１……ステアリングホイー
ル、２……ステアリングギヤボツクス、３……ピ
ツトマンアーム、５ａ……ベルトのステアリング
ユニツト側プーリ、６……ステアリングユニツ
ト、７……切換バルブ、１３……ポンプユニツ
ト、１５……後輪アクチユエータ、１６……モー
ド切換バルブ、１７……モード切換スイツチ、２
０……操舵角検出スイツチ、２１ないし２３……
リレー。
FIG. 1 is an overall configuration diagram showing an embodiment of the present invention;
Fig. 2 is an explanatory diagram of the steering angle detection switch, Fig. 3 is a diagram of the steering angle characteristics of the front and rear wheels and an operation characteristic diagram of the steering angle detection switch, Fig. 4 is a hydraulic circuit diagram, Fig. 5 is an electric circuit diagram, FIG. 6 is an overall configuration diagram showing a conventional four-wheel steering vehicle, FIG. 7 is a hydraulic circuit diagram, and FIG. 8 is an electric circuit diagram. A... Control circuit, 1... Steering wheel, 2... Steering gear box, 3... Pitman arm, 5a... Belt pulley on the steering unit side, 6... Steering unit, 7... Switching valve, 13... Pump Unit, 15... Rear wheel actuator, 16... Mode switching valve, 17... Mode switching switch, 2
0...Steering angle detection switch, 21 to 23...
relay.
Claims (1)
グギヤボツクスに連動するステアリングユニツ
ト、ポンプユニツト、後輪アクチユエータおよび
モード切換バルブを油圧配管で接続し、後輪を前
輪と逆位相に操舵する逆位相４輪操舵モード、後
輪を前輪と同位相に操舵する同位相操舵モードお
よび後輪を非操舵とする２輪操舵モードの走行を
選択的に行い、そして前輪操舵角と後輪操舵角と
が異なつている４輪操舵車において、ステアリン
グギヤボツクスに枢着されたピツトマンアームに
前輪操舵角が後輪操舵角最大値に達したことを検
出する操舵角検出スイツチと、前後輪の操舵角を
等しくする手段と、同位相４輪操舵モード走行時
に前記操舵角検出スイツチの検出信号に基づきモ
ード切換バルブを切換制御する制御回路を設け、
該制御回路は操舵角検出スイツチの検出信号に基
づき前輪操舵角が後輪操舵角最大値に達するまで
はモード切換バルブを同位相４輪操舵モード位置
に切換え、前輪操舵角が後輪操舵角最大値に達し
た後にモード切換バルブをリターン位置にする機
能を有し、前記前後輪の操舵角を等しくする手段
は、ステアリングギヤボツクスとステアリングユ
ニツトを連結するベルトのステアリングユニツト
側プーリに小径のプーリを有することを特徴とす
る４輪操舵車。 The steering unit, pump unit, rear wheel actuator, and mode switching valve that are linked to the steering gear box connected to the steering wheel are connected by hydraulic piping, and the rear wheels are steered in an anti-phase four-wheel steering mode in which the rear wheels are steered in the opposite phase to the front wheels. Four-wheel steering in which driving is selectively performed in an in-phase steering mode in which the wheels are steered in the same phase as the front wheels and a two-wheel steering mode in which the rear wheels are not steered, and the front wheel steering angle and the rear wheel steering angle are different. In a vehicle, a steering angle detection switch for detecting when a front wheel steering angle has reached a maximum rear wheel steering angle is mounted on a pitman arm pivotally connected to a steering gear box, a means for equalizing the steering angles of the front and rear wheels, and a same phase 4 A control circuit is provided to control switching of a mode switching valve based on a detection signal of the steering angle detection switch when driving in wheel steering mode,
The control circuit switches the mode switching valve to the same-phase 4-wheel steering mode position until the front wheel steering angle reaches the maximum rear wheel steering angle based on the detection signal of the steering angle detection switch, so that the front wheel steering angle reaches the maximum rear wheel steering angle. The means for equalizing the steering angles of the front and rear wheels, which has a function of setting the mode switching valve to the return position after reaching the specified value, has a small diameter pulley on the steering unit side pulley of the belt connecting the steering gear box and the steering unit. A four-wheel steering vehicle characterized by having:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1986105639U JPH0525989Y2 (en) | 1986-07-11 | 1986-07-11 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1986105639U JPH0525989Y2 (en) | 1986-07-11 | 1986-07-11 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6312474U JPS6312474U (en) | 1988-01-27 |
| JPH0525989Y2 true JPH0525989Y2 (en) | 1993-06-30 |
Family
ID=30980261
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1986105639U Expired - Lifetime JPH0525989Y2 (en) | 1986-07-11 | 1986-07-11 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0525989Y2 (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5017137U (en) * | 1973-06-08 | 1975-02-24 |
-
1986
- 1986-07-11 JP JP1986105639U patent/JPH0525989Y2/ja not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5017137U (en) * | 1973-06-08 | 1975-02-24 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6312474U (en) | 1988-01-27 |
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