JP2536534B2 - Rear wheel steering system for front and rear wheel steering vehicles - Google Patents

Rear wheel steering system for front and rear wheel steering vehicles

Info

Publication number
JP2536534B2
JP2536534B2 JP18156287A JP18156287A JP2536534B2 JP 2536534 B2 JP2536534 B2 JP 2536534B2 JP 18156287 A JP18156287 A JP 18156287A JP 18156287 A JP18156287 A JP 18156287A JP 2536534 B2 JP2536534 B2 JP 2536534B2
Authority
JP
Japan
Prior art keywords
wheel steering
steering
wheels
input shaft
output shaft
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
Application number
JP18156287A
Other languages
Japanese (ja)
Other versions
JPS6428074A (en
Inventor
彰一 庄野
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toyota Motor Corp
Original Assignee
Toyota Motor Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Toyota Motor Corp filed Critical Toyota Motor Corp
Priority to JP18156287A priority Critical patent/JP2536534B2/en
Publication of JPS6428074A publication Critical patent/JPS6428074A/en
Application granted granted Critical
Publication of JP2536534B2 publication Critical patent/JP2536534B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D7/00—Steering linkage; Stub axles or their mountings
    • B62D7/06—Steering linkage; Stub axles or their mountings for individually-pivoted wheels, e.g. on king-pins
    • B62D7/14—Steering linkage; Stub axles or their mountings for individually-pivoted wheels, e.g. on king-pins the pivotal axes being situated in more than one plane transverse to the longitudinal centre line of the vehicle, e.g. all-wheel steering
    • B62D7/15—Steering linkage; Stub axles or their mountings for individually-pivoted wheels, e.g. on king-pins the pivotal axes being situated in more than one plane transverse to the longitudinal centre line of the vehicle, e.g. all-wheel steering characterised by means varying the ratio between the steering angles of the steered wheels
    • B62D7/1554—Steering linkage; Stub axles or their mountings for individually-pivoted wheels, e.g. on king-pins the pivotal axes being situated in more than one plane transverse to the longitudinal centre line of the vehicle, e.g. all-wheel steering characterised by means varying the ratio between the steering angles of the steered wheels comprising a fluid interconnecting system between the steering control means of the different axles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D7/00—Steering linkage; Stub axles or their mountings
    • B62D7/06—Steering linkage; Stub axles or their mountings for individually-pivoted wheels, e.g. on king-pins
    • B62D7/14—Steering linkage; Stub axles or their mountings for individually-pivoted wheels, e.g. on king-pins the pivotal axes being situated in more than one plane transverse to the longitudinal centre line of the vehicle, e.g. all-wheel steering
    • B62D7/15—Steering linkage; Stub axles or their mountings for individually-pivoted wheels, e.g. on king-pins the pivotal axes being situated in more than one plane transverse to the longitudinal centre line of the vehicle, e.g. all-wheel steering characterised by means varying the ratio between the steering angles of the steered wheels

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Steering-Linkage Mechanisms And Four-Wheel Steering (AREA)

Description

【発明の詳細な説明】 ［産業上の利用分野］ 本発明は前輪の操舵に連動して後輪をも操舵する前後
輪操舵車の後輪操舵装置に関する。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear wheel steering system for a front-rear wheel steering vehicle that steers rear wheels in conjunction with steering of front wheels.

［従来技術］ この種の装置に関する第１の従来技術としては、例え
ば実開昭61−122980号公報に示されるように、前端にて
前輪操舵機構に接続され前輪の操舵操作に応じて回転す
る回転シャフトと、回転シャフトの後端に接続され同シ
ャフトの回転運動を左右後輪を操舵可能に連結するリレ
ーロッドの往復運動に変換する変換機構とを備え、回転
シャフトの回転に応じたリレーロッドの往復運動によ
り、左右後輪を前輪の操舵に連動して操舵するようにし
たものはある。[Prior Art] As a first prior art relating to this type of device, as shown in, for example, Japanese Utility Model Laid-Open No. 61-122980, the front end is connected to a front wheel steering mechanism and rotates in response to a steering operation of the front wheels. A rotary shaft connected to the rear end of the rotary shaft, and a conversion mechanism for converting the rotary motion of the shaft into a reciprocating motion of a relay rod that connects the left and right rear wheels in a steerable manner; There is one in which the left and right rear wheels are steered in conjunction with the steering of the front wheels.

また、第２の従来技術としては、例えば特開昭58−16
4477号公報に示されるように、前記操舵機構内にて前輪
の操舵操作に応じて発生された油圧を後輪操舵機構内に
設けられ後輪を操舵する油圧アクチュエータに供給し
て、同アクチュエータによって後輪を前輪に連動させて
操舵するとともに、該油圧路にオリフィスを設けること
により前輪操舵機構から後輪操舵機構への油圧の伝達時
間を遅らせ、前輪の操舵に対する後輪の操舵を遅らせる
ことにより前輪の操舵に伴う車両の運動の応答性を良好
にし、車両の安定性、特に高速走行時の車両の操安性を
良好にするようにしたものがある。また、同種の技術と
して、同公報には、前輪操舵機構による前輪の操舵状態
を電気的に検出し、該検出した前輪の操舵状態に応じて
後輪操舵機構内に設けた電気的アクチュエータを制御す
ることにより、後輪を前輪に連動させて操舵するととも
に、前記検出した前輪の操舵状態を表す信号を遅延回路
により遅延し、前記油圧制御の場合と同様、後輪の操舵
を遅らせて車両の操安性を良好にしたものも示されてい
る。A second conventional technique is, for example, Japanese Patent Laid-Open No. 58-16.
As disclosed in Japanese Patent No. 4477, the hydraulic pressure generated in accordance with the steering operation of the front wheels in the steering mechanism is supplied to a hydraulic actuator for steering the rear wheels, which is provided in the rear wheel steering mechanism, and is driven by the actuator. By steering the rear wheels in conjunction with the front wheels and providing an orifice in the hydraulic path to delay the transmission time of hydraulic pressure from the front wheel steering mechanism to the rear wheel steering mechanism, thereby delaying the steering of the rear wheels with respect to the steering of the front wheels. There is a system in which the responsiveness of the motion of the vehicle due to the steering of the front wheels is made good, and the stability of the vehicle, especially the maneuverability of the vehicle at high speed running is made good. Further, as a technique of the same type, in the publication, a steering state of front wheels by a front wheel steering mechanism is electrically detected, and an electric actuator provided in a rear wheel steering mechanism is controlled according to the detected steering state of the front wheels. As a result, the rear wheels are steered in conjunction with the front wheels, and the signal indicating the detected steering state of the front wheels is delayed by a delay circuit, and as in the case of the hydraulic control, the steering of the rear wheels is delayed. The one with improved maneuverability is also shown.

［発明が解決しようとする問題点］ 上記第１の従来技術の装置は、前輪操舵機構と後輪操
舵機構とが機械的に連結されているために、後輪操舵装
置の誤動作に対する信頼性は上記第２の従来技術による
油圧制御又は電気制御のものよりも高いが、該第１の従
来技術の装置にあっては、後輪操舵機構が前輪操舵機構
から回転シャフト及び変換機構を介して機械的に伝達さ
れる力により後輪を前輪の操舵に比例して操舵するの
で、上記第２の従来技術の油圧制御又は電気制御による
場合のように、後輪の操舵を遅らせて（特に高速走行時
に）、前輪の操舵に伴う車両の運動の応答性を良好にし
て車両の操安性、特に高速走行時の車両の操安性を良好
にするようにすることができないという問題があった。[Problems to be Solved by the Invention] In the first prior art device, since the front wheel steering mechanism and the rear wheel steering mechanism are mechanically connected to each other, the reliability of the rear wheel steering device against malfunction is high. Although higher than the hydraulic control or electric control according to the second prior art described above, in the device of the first prior art, the rear wheel steering mechanism moves from the front wheel steering mechanism to the machine via the rotary shaft and the conversion mechanism. Since the rear wheels are steered in proportion to the steering of the front wheels by the force transmitted to the front wheels, the steering of the rear wheels is delayed (especially when traveling at high speed) as in the case of the hydraulic control or electric control of the second conventional technique. At times, there is a problem that it is not possible to improve the responsiveness of the motion of the vehicle accompanying the steering of the front wheels to improve the vehicle steerability, particularly the steerability of the vehicle during high-speed traveling.

本発明は上記問題に鑑み案出されたもので、その目的
とするところは上記第１の従来技術のような前輪操舵機
構と後輪操舵機構とを機械的に連結した後輪操舵装置に
おいて、上記車両の操安性に関する問題を解決しようと
するものである。The present invention has been devised in view of the above problems, and an object of the present invention is to provide a rear wheel steering system in which a front wheel steering mechanism and a rear wheel steering mechanism are mechanically connected, as in the above-described first conventional art. The present invention seeks to solve the above-mentioned problem related to vehicle steerability.

［問題点を解決するための手段］ 上記問題を解決して本発明の目的を達成するために、
本発明の構成上の特徴は、前端にて前輪操舵機構に接続
され前輪の操舵操作に応じた回転運動を後方に伝達する
伝達機構と、前記伝達機構の後輪に接続され該伝達され
た回転運動を左右後輪を操舵可能に連結したリレーロッ
ドの往復運動に変換して左右後輪を前輪の操舵に連動し
て操舵する後輪操舵機構とを備えた前後輪操舵車の後輪
操舵装置において、前記伝達機構を、前端にて前記前輪
操舵機構に接続され前輪の操舵操作に応じて回転する入
力軸と、後端にて前記後輪操舵機構に接続され前記入力
軸の回転を前記後輪操舵機構に接続され前記入力軸の回
転を前記後輪操舵機構に伝達する出力軸と、前記入力軸
の後端部外周上及び前記出力軸の前端部外周上に渡り軸
方向に変位可能に組付けられるとともに該後端部外周面
及び前端部外周面との係合により基準軸方向位置にある
とき前記入力軸と前記出力軸との相対的な回転変位を禁
止しかつ同基準軸方向位置から前記軸方向の一方への変
位に応じて前記入力軸と前記出力軸との相対的な許容回
転変位量を徐々に大きくする連結スリーブとにより構成
するとともに、前記連結スリーブを前輪の操舵時に前記
基準軸方向位置から前記相対的な回転変位を許容する方
向に変位させる駆動手段を設けたことにある。[Means for Solving the Problems] To solve the above problems and achieve the object of the present invention,
The structural features of the present invention include a transmission mechanism which is connected to a front wheel steering mechanism at a front end thereof and transmits a rotational movement rearward according to a steering operation of the front wheel, and a transmission mechanism which is connected to a rear wheel of the transmission mechanism and which is transmitted. Rear-wheel steering system for a front-rear wheel steering vehicle including a rear-wheel steering mechanism that converts movement into reciprocating movement of a relay rod that connects steerably the left and right rear wheels to steer the left and right rear wheels in conjunction with steering of the front wheels In the above, the transmission mechanism has an input shaft connected to the front wheel steering mechanism at a front end and rotated in response to a steering operation of front wheels, and a rear end connected to the rear wheel steering mechanism to rotate the input shaft by the rear An output shaft that is connected to a wheel steering mechanism and transmits the rotation of the input shaft to the rear wheel steering mechanism, and is displaceable in the axial direction across the rear end outer circumference of the input shaft and the front end outer circumference of the output shaft. The rear end outer peripheral surface and the front end outer peripheral surface that are assembled together Of the input shaft and the output shaft are prevented from relative rotational displacement due to the engagement of the input shaft and the input shaft in accordance with the displacement from the reference axial direction position to one of the axial directions. The connecting sleeve is configured to gradually increase the relative rotational displacement relative to the output shaft, and the connecting sleeve is arranged in a direction in which the relative rotational displacement is allowed from the reference axial direction position when steering the front wheels. The driving means for displacing is provided.

［発明の作用］ 上記のように構成した本発明においては、連結スリー
ブが基準軸方向位置にあるとき、入力軸と出力軸との回
転変位が禁止されるので、前輪の操舵に対応した入力軸
の回転変位量が連結スリーブ及び出力軸を介して後輪操
舵機構にそのまま伝達され、後輪は前輪の操舵状態に対
応した位置に固定される。また、かかる状態で、前輪を
操舵すると、該操舵時には、駆動手段が連結スリーブを
基準軸方向位置から入力軸と出力軸との相対的な回転変
位を許容する方向に変位させ、この許容回転変位量は前
記連結スリーブの変位に応じて徐々に大きくなるので、
前輪の操舵に伴う入力軸の回転運動は徐々に遅れなが
ら、すなわち入力軸の回転に対して位相遅れをもって出
力軸に伝達される。そして、後輪操舵機構がこの出力軸
の回転に応じて左右後輪を操舵するので、同後輪は前輪
の操舵に対して位相遅れをもって操舵されることにな
る。[Operation of the Invention] In the present invention configured as described above, since the rotational displacement between the input shaft and the output shaft is prohibited when the connecting sleeve is in the reference axial direction position, the input shaft corresponding to the steering of the front wheels is prohibited. Is transmitted to the rear wheel steering mechanism as it is through the connecting sleeve and the output shaft, and the rear wheels are fixed at a position corresponding to the steering state of the front wheels. Further, when the front wheels are steered in this state, the driving means displaces the connecting sleeve from the reference axial direction position in a direction in which relative rotation displacement between the input shaft and the output shaft is permitted during the steering, and the allowable rotational displacement is caused. Since the amount gradually increases with the displacement of the connecting sleeve,
The rotational movement of the input shaft due to the steering of the front wheels is gradually delayed, that is, transmitted to the output shaft with a phase delay with respect to the rotation of the input shaft. Since the rear wheel steering mechanism steers the left and right rear wheels in response to the rotation of the output shaft, the rear wheels are steered with a phase delay with respect to the steering of the front wheels.

［発明の効果］ 上記作用説明からも明らかなように、本発明によれ
ば、前輪操舵機構と後輪操舵機構とを伝達機構を介して
機械的に連結した前後輪操舵車において、上記第２の従
来技術の装置のように、前輪の操舵時に、後輪を前輪の
操舵に対して位相遅れをもって操舵するので、前輪の操
舵に伴う車両の運動の応答性を良好にでき、前輪操舵に
伴う当該車両の操安性が良好になる。[Effects of the Invention] As is apparent from the above description of the operation, according to the present invention, in the front and rear wheel steering vehicle in which the front wheel steering mechanism and the rear wheel steering mechanism are mechanically connected via the transmission mechanism, When steering the front wheels, the rear wheels are steered with a phase delay with respect to the steering of the front wheels as in the prior art device described above. Therefore, it is possible to improve the responsiveness of the motion of the vehicle accompanying the steering of the front wheels. The maneuverability of the vehicle is improved.

また、連結スリーブが基準軸方向位置にあれば、入力
軸と出力軸との回転変位が禁止されて、後輪は前輪の操
舵状態に対応した位置に固定されるので、例えば前輪が
中立位置にあって当該車両が直進状態にあるときには、
左右後輪も中立状態に固定され、左右後輪が左右にふら
つくことがなく同後輪の操舵に対する剛性が確保され
る。Further, when the connecting sleeve is at the reference axial direction position, the rotational displacement of the input shaft and the output shaft is prohibited, and the rear wheels are fixed at the position corresponding to the steering state of the front wheels, so that the front wheels are at the neutral position, for example. When the vehicle is in a straight ahead state,
The left and right rear wheels are also fixed in a neutral state, and the left and right rear wheels do not sway to the left and right, and the rigidity of the rear wheels for steering is secured.

［実施例］ a.第１実施例 以下、本発明の第１実施例を図面を用いて説明する
と、第１図は本発明に係る前後輪操舵車の全体を概略的
に示している。この前後輪操舵車は左右前輪FW1,FW2を
操蛇する前輪操舵機構Ａと、左右後輪RW1,RW2を操舵す
る後輪操舵機構Ｂと、前輪操舵機構Ａ及び後輪操舵機構
Ｂを機械的に連結する連結装置Ｃとを備えている。[First Embodiment] a. First Embodiment Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 schematically shows an entire front and rear wheel steering vehicle according to the present invention. This front and rear wheel steering vehicle includes a front wheel steering mechanism A that steers the left and right front wheels FW1 and FW2, a rear wheel steering mechanism B that steers the left and right rear wheels RW1 and RW2, a front wheel steering mechanism A and a rear wheel steering mechanism B. And a connecting device C for connecting to.

前輪操舵機構Ａは操舵ハンドル11を有する。操舵ハン
ドル11は操舵軸12,ピニオン13,ラックバー14,左右タイ
ロッド15a,15b及び左右ナックルアーム16a,16bを介して
左右前輪FW1,FW2に連結されており、同ハンドル11の回
動に応じて左右前輪FW1,FW2の操舵されるようになって
いる。操舵軸12の下部には制御バルブ17が組付けられて
おり、同バルブ17は油圧ポンプ18により吐出され導管P1
を介して供給される作動油を操舵軸12に作用する操舵ト
ルクに応じてパワーシリンダ21の一方の油室に供給し、
かつ同シリンダ21の他方の油室からの作動油を導管P2を
介してリザーバ22に排出する。パワーシリンダ21は前記
作動油の給排に応じてラックバー14を駆動することによ
り、左右前輪FW1,FW2の前記操舵を助勢するようになっ
ている。The front wheel steering mechanism A has a steering wheel 11. The steering wheel 11 is connected to the left and right front wheels FW1 and FW2 via the steering shaft 12, the pinion 13, the rack bar 14, the left and right tie rods 15a and 15b, and the left and right knuckle arms 16a and 16b. The left and right front wheels FW1 and FW2 are steered. A control valve 17 is attached to the lower part of the steering shaft 12, and the valve 17 is discharged by a hydraulic pump 18 and is connected to the conduit P1.
The hydraulic oil supplied via the is supplied to one oil chamber of the power cylinder 21 in accordance with the steering torque acting on the steering shaft 12,
Moreover, the hydraulic oil from the other oil chamber of the cylinder 21 is discharged to the reservoir 22 via the conduit P2. The power cylinder 21 drives the rack bar 14 according to the supply and discharge of the hydraulic oil to assist the steering of the left and right front wheels FW1 and FW2.

後輪操舵機構Ｂは車体（図示しない）に固定された変
換機23を有する。変換機23は入力軸23aにて入力した回
転運動を出力軸23bの左右動に変換するとともに、図示
しないモータの制御により前記入力軸23aの回転に対す
る前記出力軸の左右動の方向及びその移動量を制御する
もので、例えば実開昭61−122980号公報に示されたもの
を利用できる。この変換機23の出力軸23bはリレーロッ
ド24に連結されており、同ロッド24は前記出力軸23bと
一体的に左右動する。リレーロッド24の両端は各々左右
タイロッド25a,25b及び左右ナックルアーム26a,26bを介
して左右後輪RW1,RW2に連結されており、前記リレーロ
ッド24の左右動により左右後輪RW1,RW2が操舵されるよ
うになっている。The rear wheel steering mechanism B has a converter 23 fixed to a vehicle body (not shown). The converter 23 converts the rotational movement input by the input shaft 23a into the left-right movement of the output shaft 23b, and the direction of the left-right movement of the output shaft with respect to the rotation of the input shaft 23a and the movement amount thereof by the control of a motor (not shown). For example, the one disclosed in Japanese Utility Model Laid-Open No. 61-122980 can be used. The output shaft 23b of the converter 23 is connected to a relay rod 24, and the rod 24 moves left and right integrally with the output shaft 23b. Both ends of the relay rod 24 are connected to the left and right rear wheels RW1 and RW2 via the left and right tie rods 25a and 25b and the left and right knuckle arms 26a and 26b, respectively, and the left and right rear wheels RW1 and RW2 are steered by the left and right movements of the relay rod 24. It is supposed to be done.

連結装置Ｃは、第１図乃至第３図に示すように、左右
前輪FW1,FW2の操舵に伴う回転運動を後輪操舵機構Ｂに
伝達する伝達機構C1と、同機構C1を制御する制御装置C2
とを有する。伝達機構C1はトーションバー27により連結
された入力軸28及び出力軸31と、同トーションバー27と
ともに両軸28,31を連結する連結スリーブ32とからな
る。入力軸28の前端は中間軸33を介してピニオン軸34の
後端に接続されているとともに、ピニオン軸34の前端は
ラックバー14に噛合っており、ラックバー14の左右動に
より入力軸28が回転するようになっている。入力軸28の
後端部には大径部28aが形成されており、同大径部28aの
外周上には軸方向に平行な複数条の溝28bが形成されて
いる。出力軸31の後端は中間軸35を介して変換機23の入
力軸23aの前端に接続されており、出力軸31の回転が変
換機23の入力軸23aに伝達されるようになっている。出
力軸31の前端部には大径部31aが形成されており、同大
径部31aの外周上には前方から後方に向けて幅が狭くな
る複数条の溝31bが形成されている。なお、これらの軸2
8,31,33,34,35は車体（図示しない）に回転可能に支持
されている。As shown in FIG. 1 to FIG. 3, the coupling device C includes a transmission mechanism C1 for transmitting the rotational motion of the left and right front wheels FW1 and FW2 to the rear wheel steering mechanism B, and a control device for controlling the mechanism C1. C2
And The transmission mechanism C1 includes an input shaft 28 and an output shaft 31 which are connected by a torsion bar 27, and a connecting sleeve 32 which connects the shafts 28 and 31 together with the torsion bar 27. The front end of the input shaft 28 is connected to the rear end of the pinion shaft 34 via the intermediate shaft 33, and the front end of the pinion shaft 34 meshes with the rack bar 14, and the left and right movements of the rack bar 14 cause the input shaft 28 to move. Is designed to rotate. A large diameter portion 28a is formed at the rear end of the input shaft 28, and a plurality of grooves 28b parallel to the axial direction are formed on the outer circumference of the large diameter portion 28a. The rear end of the output shaft 31 is connected to the front end of the input shaft 23a of the converter 23 via the intermediate shaft 35, and the rotation of the output shaft 31 is transmitted to the input shaft 23a of the converter 23. . A large diameter portion 31a is formed at the front end portion of the output shaft 31, and a plurality of grooves 31b having a width narrowing from the front to the rear are formed on the outer periphery of the large diameter portion 31a. Note that these axes 2
8, 31, 33, 34, and 35 are rotatably supported by a vehicle body (not shown).

連結スリーブ32の内周面の前半分には軸方向に平行な
複数条の凸部32aが形成されており、同凸部32aと溝28b
との係合により、同スリーブ32は入力軸28の大径部28a
に回転不能かつ軸方向に変位可能に組付けられている。
また、連結スリーブ32の内周面の後半分には前方から後
方に向けて幅が狭くなる複数条の凸部32bが形成されて
おり、同凸部32bと溝31bとの係合により、同スリーブ32
は出力軸31の大径部31aに軸方向に変位可能に、かつ最
後方位置（基準位置）から前方に変位するに従って同大
径部31aに対して許容回転変位量が徐々に増加するよう
に組付けられている。A plurality of projections 32a parallel to the axial direction are formed on the front half of the inner peripheral surface of the connecting sleeve 32, and the projections 32a and the grooves 28b are formed.
Due to the engagement with the sleeve 32, the sleeve 32 becomes the large diameter portion 28a of the input shaft 28.
It is attached so that it cannot rotate but can be displaced in the axial direction.
In addition, a plurality of projections 32b having a width narrowing from the front to the rear are formed on the rear half of the inner peripheral surface of the connecting sleeve 32, and the projections 32b and the grooves 31b are engaged with each other to form the same projection. Sleeve 32
Is so as to be axially displaceable to the large diameter portion 31a of the output shaft 31, and the permissible rotational displacement amount gradually increases with respect to the large diameter portion 31a as it is displaced forward from the rearmost position (reference position). It is assembled.

制御装置C2は車体（図示しない）に組付けられたシリ
ンダ36を有する。シリンダ36はその内周上を液密的に摺
動するピストン36aにより左右室36b,36cに区画されてい
る。右室36cは導管P3を介して制御バルブ17の上流に位
置する導管P1に連通している。左室36bにはピストン36a
を第２図の左方向に押圧するスプリング37が収容されて
おり、ピストン36aは導管P1の油圧が低いときスプリン
グ37の付勢力により第２図右方向に変位し、かつハンド
ル11の回動に伴って導管P1の油圧が高くなって、該油圧
による力がスプリング37の付勢力より大きくなると、第
２図左方向に変位する。このピストン36aに固定される
とともにシリンダ36の底面を貫通したピストンロッド38
は連結ロッド41を介してフォーク42に接続されている。
フォーク42は連結スリーブ32の外周上に周方向に形成し
た溝32cに回転可能に嵌合されており、連結スリーブ32
がピストン36aの変位に応じて前後方向に変位するよう
になっている。The control device C2 has a cylinder 36 mounted on a vehicle body (not shown). The cylinder 36 is divided into left and right chambers 36b and 36c by a piston 36a that slides on the inner circumference of the cylinder 36 in a liquid-tight manner. The right chamber 36c communicates with the conduit P1 located upstream of the control valve 17 via the conduit P3. The left ventricle 36b has a piston 36a
2 is accommodated in the spring 37 which pushes to the left in FIG. 2, the piston 36a is displaced to the right in FIG. 2 by the urging force of the spring 37 when the hydraulic pressure in the conduit P1 is low, and the handle 11 is rotated. Along with this, when the hydraulic pressure of the conduit P1 becomes higher and the force due to the hydraulic pressure becomes larger than the urging force of the spring 37, it is displaced leftward in FIG. A piston rod 38 fixed to this piston 36a and penetrating the bottom surface of the cylinder 36
Is connected to a fork 42 via a connecting rod 41.
The fork 42 is rotatably fitted in a groove 32c formed in the circumferential direction on the outer circumference of the connecting sleeve 32.
Is displaced in the front-rear direction according to the displacement of the piston 36a.

次に、上記のように構成した実施例の動作を説明す
る。今、当該車両が直進走行していて、ハンドル11が中
立状態に保たれていれば、油圧ポンプ18により、リザー
バ22から汲み上げられかつ吐出される作動油は導管P1、
制御バルブ17及び導管P2を介して還流しているので、制
御バルブ17の上流すなわち導管P1内における油圧は低く
保たれる。このため、シリンダ36の右室36c内の油圧も
低く、ピストン36aはスプリング37の付勢力により第２
図の右方向に変位した状態にある。このピストン36aの
右方向の変位により、連結スリーブ32も第２図及び第３
図の右方向すなわち車体に対し最後方位置（基準位置）
にある。この場合、出力軸31の大径部31aに形成した溝3
1bに嵌合された連結スリーブ32の凸部32bは第4A図に示
す状態にあり、連結スリーブ32と出力軸31との相対的な
回転変位が禁止される。これにより、後輪操舵機構Ｂに
おける変換器23の入力軸23aも堅固に固定され、左右後
輪WR1,WR2は外力等によつてふらつくこともなく、当該
車両の直進性は良好に保たれる。Next, the operation of the embodiment configured as described above will be described. Now, when the vehicle is traveling straight ahead and the handle 11 is kept in the neutral state, the hydraulic oil pumped up and discharged from the reservoir 22 by the hydraulic pump 18 is the conduit P1,
Since the oil is recirculated through the control valve 17 and the conduit P2, the hydraulic pressure upstream of the control valve 17, that is, in the conduit P1 is kept low. Therefore, the hydraulic pressure in the right chamber 36c of the cylinder 36 is also low, and the piston 36a moves to the second position by the urging force of the spring 37.
It is in the state of being displaced to the right in the figure. Due to the displacement of the piston 36a in the right direction, the connecting sleeve 32 is also moved as shown in FIGS.
In the right direction of the figure, that is, the rearmost position with respect to the vehicle body (reference position)
It is in. In this case, the groove 3 formed in the large diameter portion 31a of the output shaft 31
The convex portion 32b of the connecting sleeve 32 fitted to the 1b is in the state shown in FIG. 4A, and the relative rotational displacement between the connecting sleeve 32 and the output shaft 31 is prohibited. As a result, the input shaft 23a of the converter 23 in the rear wheel steering mechanism B is also firmly fixed, the left and right rear wheels WR1, WR2 do not fluctuate due to external force, etc., and the straightness of the vehicle is kept good. .

かかる車両の直進走行中、ハンドル11が回動される
と、左右前輪FW1,FW2は同ハンドル11の回動に応じてパ
ワーシリンダ21により助勢されながら操舵される。この
左右前輪FW1,FW2の操舵に伴うラックバー14の左右動は
ピニオン軸34の回転に変換され、該ピニオン軸34の回転
は中間軸33を介して伝達機構C2の入力軸28に伝達され
る。伝達機構C2においては、入力軸28の回転がトーショ
ンバー27及び連結スリーブ32を介して出力軸31に伝達さ
れる。かかる場合、左右前輪FW1,FW2の操舵に伴う制御
バルブ17の作用により、同バルブ17の上流すなわち導管
P1内における油圧が上昇し、同油圧が導管P3を介してシ
リンダ36の右油室36cに伝達されるので、ピストン36aは
スプリング37の付勢力に抗して第２図左方向に変位す
る。この変位はピストンロッド38及び連結ロッド41を介
してフォーク42に伝達され、フォーク42が連結スリーブ
32を第２図及び第３図の左方向すなわち車体に対して前
方に駆動し、同スリーブ32はその凸部32aと溝28bとの係
合によって入力軸28との相対的な回転変位なく大径部28
aの外周上を前方に移動する。一方、この連結スリーブ3
2の移動により、同スリーブ32の凸部32bの外側面と出力
軸31の大径部31aに形成した溝31bの内側面との間には隙
間ができ、連結スリーブ32と出力軸との間には相対的な
回転変位が許容される状態となる。そのため、上述の入
力軸28から出力軸31への回転力の伝達においては、トー
ションバー27が捩れかつ連結スリーブ32の凸部32bの外
側面が、第４図及び第4C図に示すように、溝31bの内側
面に沿って摺動しながら、入力軸28の回転に応じて出力
軸31が回転することになる。このことは、出力軸31の回
転が入力軸28の回転に対し位相遅れをもつことを意味
し、左右前輪FW1,FW2が操舵された場合、出力軸31は同
前輪FW1,FW2の操舵に対し若干遅れながら回転する。When the steering wheel 11 is rotated while the vehicle is traveling straight, the left and right front wheels FW1 and FW2 are steered while being assisted by the power cylinder 21 in response to the rotation of the steering wheel 11. The lateral movement of the rack bar 14 due to the steering of the left and right front wheels FW1, FW2 is converted into rotation of the pinion shaft 34, and the rotation of the pinion shaft 34 is transmitted to the input shaft 28 of the transmission mechanism C2 via the intermediate shaft 33. . In the transmission mechanism C2, the rotation of the input shaft 28 is transmitted to the output shaft 31 via the torsion bar 27 and the connecting sleeve 32. In such a case, due to the action of the control valve 17 accompanying the steering of the left and right front wheels FW1 and FW2, the upstream side of the valve 17, that is, the conduit
Since the hydraulic pressure in P1 rises and the hydraulic pressure is transmitted to the right oil chamber 36c of the cylinder 36 via the conduit P3, the piston 36a is displaced leftward in FIG. 2 against the biasing force of the spring 37. This displacement is transmitted to the fork 42 via the piston rod 38 and the connecting rod 41, and the fork 42 is connected to the connecting sleeve.
The sleeve 32 is driven leftward in FIGS. 2 and 3, that is, forward with respect to the vehicle body, and the sleeve 32 is engaged with the convex portion 32a and the groove 28b of the sleeve 32 so that the sleeve 32 does not have a large rotational displacement relative to the input shaft 28. Diameter 28
Move forward on the outer circumference of a. Meanwhile, this connecting sleeve 3
By the movement of 2, a gap is formed between the outer surface of the convex portion 32b of the sleeve 32 and the inner surface of the groove 31b formed in the large diameter portion 31a of the output shaft 31, and the gap between the connecting sleeve 32 and the output shaft is formed. Is in a state where relative rotational displacement is allowed. Therefore, in the transmission of the rotational force from the input shaft 28 to the output shaft 31 described above, the torsion bar 27 is twisted and the outer surface of the convex portion 32b of the coupling sleeve 32 is, as shown in FIGS. 4 and 4C, The output shaft 31 rotates according to the rotation of the input shaft 28 while sliding along the inner surface of the groove 31b. This means that the rotation of the output shaft 31 has a phase lag with respect to the rotation of the input shaft 28, and when the left and right front wheels FW1 and FW2 are steered, the output shaft 31 does not respond to the steering of the front wheels FW1 and FW2. Rotate with a slight delay.

この出力軸31の回転は中間軸35を介して変換機23の入
力軸23aに伝達され、変換器23がこの回転を往復運動に
変換するとともに、外変換した往復運動を出力軸23bを
介してリレーロッド24に伝達する。その結果、リレーロ
ッド24が左又は右に変位され、左右後輪RW1,RW2が伝達
機構C1から伝達される回転運動すなわち左右前輪FW1,FW
2の操舵に応じて操舵される。かかる左右後輪RW1,RW2の
操舵においては、上述のように、変換器23に入力される
回転が左右前輪FW1,FW2の操舵に対して位相遅れをもつ
ので、変換器23にて変換された変位すなわちリレーロッ
ド24の左右方向の変位も左右前輪FW1,FW2の操舵に対し
て位相遅れをもつことになり、左右後輪RW1,RW2が左右
前輪FW1,FW2に対して位相遅れをもって操舵される。The rotation of the output shaft 31 is transmitted to the input shaft 23a of the converter 23 via the intermediate shaft 35, the converter 23 converts the rotation into reciprocating motion, and the externally converted reciprocating motion via the output shaft 23b. It is transmitted to the relay rod 24. As a result, the relay rod 24 is displaced left or right, and the left and right rear wheels RW1, RW2 are rotated by the transmission mechanism C1, that is, the left and right front wheels FW1, FW.
It is steered according to the steering of 2. In the steering of the left and right rear wheels RW1 and RW2, as described above, the rotation input to the converter 23 has a phase delay with respect to the steering of the left and right front wheels FW1 and FW2, and thus is converted by the converter 23. The displacement, that is, the horizontal displacement of the relay rod 24 also has a phase delay with respect to the steering of the left and right front wheels FW1, FW2, and the left and right rear wheels RW1, RW2 are steered with a phase delay with respect to the left and right front wheels FW1, FW2. .

このように、前輪操舵機構Ａと後輪操舵機構Ｂとを連
結装置Ｃにより機械的に連結した前後輪操舵車において
も、左右前輪FW1,FW2の操舵時には、伝達機構C1及び制
御装置C2の作用により、左右後輪RW1,RW2を左右前輪FW
1,FW2に対して位相遅れをもちながら同前輪FW1,FW2に連
動して操舵できるので、左右前輪FW1,FW2の操舵に伴う
車両の応答性を良好にでき、同前輪FW1,FW2の操舵時に
おける当該車両の操安性が良好になる。As described above, even in the front and rear wheel steering vehicle in which the front wheel steering mechanism A and the rear wheel steering mechanism B are mechanically connected by the connecting device C, the operation of the transmission mechanism C1 and the control device C2 is performed when the left and right front wheels FW1 and FW2 are steered. The left and right rear wheels RW1 and RW2 to the left and right front wheels FW
Since there is a phase lag with respect to 1 and FW2, steering can be performed in conjunction with the front wheels FW1 and FW2, so the responsiveness of the vehicle accompanying steering of the left and right front wheels FW1 and FW2 can be improved, and when steering the front wheels FW1 and FW2. The maneuverability of the vehicle is improved.

また、ハンドル11の回動が終了されると、制御バルブ
17の作用により同バルブ17の上流すなわち導管P1内の油
圧が低くなり、シリンダ36のピストン36aはスプリング3
7の付勢力により第２図右方向に再び変位する。このピ
ストン36aの変位により、上記のように連結スリーブ32
は車体に対して後方に変位して基準位置にて停止する。
かかる場合、連結スリーブ32の凸部32bと溝31bとの係合
により、同スリーブ32は第4C図の状態から第4B図の状態
を経て第4A図の状態に変位する。その結果、出力軸31は
連結スリーブ32により入力軸28に対して回転変位不能に
固定されるようになり、左右後輪RW1,RW2が外力等によ
りふらつくことがなくなる。すなわち、左右前輪FW1,FW
2の非操舵時における左右後輪RW1,RW2の操舵に対する剛
性が確保される。また、この実施例によれば、トーショ
ンバー27により入力軸28と出力軸31とが機械的に連結さ
れているので、伝達機構C1の故障時における信頼性も高
くなる。When the rotation of the handle 11 is completed, the control valve
Due to the action of 17, the hydraulic pressure upstream of the valve 17, that is, the hydraulic pressure in the conduit P1 is lowered, and the piston 36a of the cylinder 36 is set to the spring 3
It is displaced again to the right in Fig. 2 by the urging force of 7. Due to this displacement of the piston 36a, the connecting sleeve 32
Moves rearward with respect to the vehicle body and stops at the reference position.
In this case, due to the engagement between the convex portion 32b of the connecting sleeve 32 and the groove 31b, the sleeve 32 is displaced from the state of FIG. 4C to the state of FIG. 4B to the state of FIG. 4A. As a result, the output shaft 31 is fixed to the input shaft 28 by the connecting sleeve 32 so that it cannot be rotationally displaced, and the left and right rear wheels RW1, RW2 do not wobble due to external force or the like. That is, the left and right front wheels FW1, FW
The rigidity of the left and right rear wheels RW1 and RW2 against steering when 2 is not steered is secured. Further, according to this embodiment, since the input shaft 28 and the output shaft 31 are mechanically connected by the torsion bar 27, the reliability at the time of failure of the transmission mechanism C1 is also increased.

b.第２実施例 次に、伝達機構C1における連結スリーブ32の移動制御
を車両の高速走行時にのみ行うように、上記第１実施例
の制御装置C2を変形した本発明の第２実施例を図面を用
いて説明する。b. Second Embodiment Next, a second embodiment of the present invention in which the control device C2 of the first embodiment is modified so that the movement control of the connecting sleeve 32 in the transmission mechanism C1 is performed only when the vehicle is traveling at high speed. This will be described with reference to the drawings.

第５図は該変形部分と概略的に示しており、この第２
実施例による制御装置C2は電磁切換え弁51を有する。電
磁切換え弁51は電磁ソレノイド51a及びスプリング51bを
備えており、同ソレノイド51aの非励磁状態にてスプリ
ング51bの付勢力により第１状態（図示状態）に設定さ
れ、シリンダ36の右室36cを導管P4及び導管P5を介して
リザーバ22に連通させる。電磁ソレノイド51aが励磁さ
れると、電磁切換え弁51は第２状態に設定され、制御バ
ルブ17の上流すなわち導管P1を導管P6及び導管P4を介し
てシリンダ36の右室36cに連通させる。FIG. 5 schematically shows this modified part, and this second part
The control device C2 according to the embodiment has an electromagnetic switching valve 51. The electromagnetic switching valve 51 includes an electromagnetic solenoid 51a and a spring 51b. When the solenoid 51a is in a non-excited state, the solenoid 51a is set to the first state (the state shown in the figure) by the urging force of the spring 51b, and the right chamber 36c of the cylinder 36 is piped. It communicates with the reservoir 22 through P4 and the conduit P5. When the electromagnetic solenoid 51a is excited, the electromagnetic switching valve 51 is set to the second state, and the upstream of the control valve 17, that is, the conduit P1 is connected to the right chamber 36c of the cylinder 36 via the conduits P6 and P4.

この電磁切換え弁51は車速センサ52及び電気制御回路
53によって制御されるようになっている。車速センサ52
は変速機（図示しない）、各車輪FW1,FW2,RW1,RW2等の
回転をピックアップすることにより当該車両の車速Ｖを
検出して、該車速Ｖを表す車速信号を出力する。電気制
御回路53は電磁ソレノイド51aの励磁、非励磁を制御す
るもので、車速センサ52からの車速信号により表された
車速Ｖが所定車速VO（例えば毎時40〜50キロメートル）
以上のとき電磁ソレノイド51aを励磁し、かつ車速Ｖが
所定車速VO未満のとき電磁ソレノイド51aを励磁しな
い。残りの部分は上記第１実施例と同じである。This electromagnetic switching valve 51 is a vehicle speed sensor 52 and an electric control circuit.
It is controlled by 53. Vehicle speed sensor 52
Detects the vehicle speed V of the vehicle by picking up rotations of a transmission (not shown), wheels FW1, FW2, RW1, RW2, etc., and outputs a vehicle speed signal representing the vehicle speed V. The electric control circuit 53 controls the excitation and non-excitation of the electromagnetic solenoid 51a, and the vehicle speed V represented by the vehicle speed signal from the vehicle speed sensor 52 is a predetermined vehicle speed V O (for example, 40 to 50 kilometers per hour).
Exciting the electromagnetic solenoid 51a when the above and the vehicle speed V is not energized the electromagnetic solenoid 51a when less than the predetermined vehicle speed V O. The remaining part is the same as in the first embodiment.

上記のように構成した第２実施例においては、当該車
両が低速走行中、すなわち車速センサ52により検出され
た車速Ｖが所定車速VO未満であれば、電磁ソレノイド51
aは非励磁状態に保たれて電磁切換え弁51が第１状態
（図示状態）に設定されるので、シリンダ36の右室36c
は導管P4、電磁切換え弁51及び導管P5を介してリザーバ
22に連通する。その結果、かかる状態においては、ピス
トン36aはスプリング36bにより常に第５図右方向に変位
していて、連結スリーブ32は最後方位置（基準位置）に
位置するので、連結スリーブ32と出力軸31との相対的な
回転変位は、第4A図に示すように、禁止される。これに
より、かかる車両の低速走行中においては、左右後輪RW
1,RW2は左右前輪FW1,FW2の操舵に即座に応答して操舵さ
れることになる。このように左右前輪FW1,FW2の操舵に
伴う車両の運動応答性が問題にならない低速走行時にお
いては、左右後輪RW1,RW2の操舵応答を速くすることに
より、車両の走行性能が向上する。In the second embodiment configured as described above, if the vehicle is traveling at a low speed, that is, if the vehicle speed V detected by the vehicle speed sensor 52 is less than the predetermined vehicle speed V O , the electromagnetic solenoid 51
Since a is kept in the non-excited state and the electromagnetic switching valve 51 is set to the first state (state shown in the figure), the right chamber 36c of the cylinder 36 is
Is a reservoir via conduit P4, electromagnetic switching valve 51 and conduit P5.
Connect to 22. As a result, in this state, the piston 36a is always displaced rightward in FIG. 5 by the spring 36b, and the connecting sleeve 32 is located at the rearmost position (reference position). Relative rotational displacement of is prohibited, as shown in Figure 4A. As a result, the right and left rear wheels RW
1, RW2 will be steered in immediate response to the steering of the left and right front wheels FW1, FW2. As described above, during low-speed traveling in which the vehicle motion responsiveness associated with steering of the left and right front wheels FW1 and FW2 does not pose a problem, the traveling performance of the vehicle is improved by increasing the steering response of the left and right rear wheels RW1 and RW2.

一方、当該車両が高速走行中、すなわち車速センサ52
により検出される車速Ｖが所定車速VO以上であれば、電
気制御回路53による電磁ソレノイド51aの励磁によって
電磁切換え弁51は第２状態に設定されるので、シリンダ
36の右室36cは導管P4、電磁切換え弁51及び導管P6を介
して導管P1に連通する。この状態は上記第１実施例の場
合と全く同じであり、連結スリーブ32は、上記第１実施
例の場合と同様に、左右前輪FW1,FW2の操舵に応じて前
後方向に変位制御される。その結果、かかる車両の高速
走行中においては、上記第１実施例と同等な効果が期待
される。On the other hand, the vehicle is traveling at high speed, that is, the vehicle speed sensor 52
If the vehicle speed V detected by is greater than or equal to the predetermined vehicle speed V O , the electromagnetic switching valve 51 is set to the second state by the excitation of the electromagnetic solenoid 51a by the electric control circuit 53.
The right chamber 36c of 36 communicates with the conduit P1 via the conduit P4, the electromagnetic switching valve 51 and the conduit P6. This state is exactly the same as in the case of the first embodiment, and the displacement of the connecting sleeve 32 is controlled in the front-rear direction in accordance with the steering of the left and right front wheels FW1, FW2, as in the case of the first embodiment. As a result, while the vehicle is traveling at high speed, the same effect as that of the first embodiment is expected.

c.第３実施例 次に、伝達機構C1における連結スリーブ32の移動制御
を油圧を用いないで電気的に行うように、上記第２実施
例の制御装置C2を変形した本発明の第３実施例を図面を
用いて説明する。c. Third Embodiment Next, a third embodiment of the present invention in which the control device C2 of the second embodiment is modified so that the movement control of the connecting sleeve 32 in the transmission mechanism C1 is electrically performed without using hydraulic pressure. An example will be described with reference to the drawings.

第６図は該変形部分を概略的に示しており、この第３
実施例による制御装置C2は電動モータ61を有する。伝動
モータ61の回転軸61aの先端にはピニオン62が固定され
ており、同ピニオン62はラックバー63に噛合している。
ラックバー63は連結ロッド41に接続されており、同バー
63の第６図左右方向の移動によって連結ロッド41及びフ
ォーク42を介して連結スリーブ32が第６図左右方向すな
わち車体に対して前後方向に移動するようになってい
る。FIG. 6 schematically shows the deformed portion.
The control device C2 according to the embodiment has an electric motor 61. A pinion 62 is fixed to the tip of the rotary shaft 61a of the transmission motor 61, and the pinion 62 meshes with the rack bar 63.
The rack bar 63 is connected to the connecting rod 41,
When 63 is moved in the left-right direction in FIG. 6, the connecting sleeve 32 is moved in the left-right direction in FIG. 6, that is, the front-rear direction with respect to the vehicle body via the connecting rod 41 and the fork 42.

電動モータ61は車速センサ64、前輪操舵角センサ65及
びマイクロコンピュータ66により制御されるようになっ
ている。車速センサ64は上記第２実施例の場合と同様に
構成され、車速Ｖを表す信号を出力する。前輪操舵角セ
ンサ65は操舵軸12（第１図）の回転角又はラックバー14
（第１図）の変位量を検出することにより、左右前輪FW
1,FW2の操舵角θｆを表す信号を出力する。マイクロコ
ンピュータ66は入出力インタフェース、読出し専用メモ
リ（ROM）、中央処理装置（CPU）、書込み可能メモリ
（RAM）等により構成され、読出し専用メモリに記憶さ
れている第７図のフローチャートに対応したプログラム
の実行により、車速Ｖ及び前輪操舵角θｆに基づき電動
モータ61を駆動制御する。The electric motor 61 is controlled by a vehicle speed sensor 64, a front wheel steering angle sensor 65 and a microcomputer 66. The vehicle speed sensor 64 has the same structure as that of the second embodiment, and outputs a signal representing the vehicle speed V. The front wheel steering angle sensor 65 is the rotation angle of the steering shaft 12 (FIG. 1) or the rack bar 14
By detecting the displacement amount (Fig. 1), the left and right front wheels FW
A signal indicating the steering angle θf of 1 and FW2 is output. The microcomputer 66 is composed of an input / output interface, a read-only memory (ROM), a central processing unit (CPU), a writable memory (RAM), etc., and is a program stored in the read-only memory and corresponding to the flowchart of FIG. By executing the above, the electric motor 61 is drive-controlled based on the vehicle speed V and the front wheel steering angle θf.

上記のように構成した実施例の動作を第７図のフロー
チャートを参照しながら説明する。イグニッションスイ
ッチ（図示しない）の閉成により、マイクロコンピュー
タ66はステップ70にてプログラムの実行を開始し、ステ
ップ71にて前輪操舵角センサ65により検出された前輪操
舵角θｆを新前輪操舵角θfNEWとして取込み記憶する。
このステップ71の処理後、マイクロコンピュータ66はス
テップ72〜78からなる循環処理を実行しながら、電動モ
ータ61を制御する。ステップ72〜74においては、マイク
ロコンピュータ66は旧後輪操舵角θfOLDを新前輪操舵角
θfNEWで一循環処理毎に更新し、かつ新前輪操舵角θf
NEWを前輪操舵角センサ65により検出された前輪操舵角
θｆで一循環処理毎に更新しながら、演算θＶ＝（θf
NEW−θfOLD）／△ｔを実行することにより左右前輪FW
1,FW2の操舵速度θＶを計算するとともに、車速Ｖを車
速センサ64により検出された車速で一循環処理毎に更新
していく。なお、前記演算式中の△ｔはステップ72〜78
からなる一循環処理に要する時間である。The operation of the embodiment configured as described above will be described with reference to the flowchart of FIG. When the ignition switch (not shown) is closed, the microcomputer 66 starts executing the program in step 70, and in step 71 the front wheel steering angle θf detected by the front wheel steering angle sensor 65 is changed to the new front wheel steering angle θf NEW. It is taken in and memorized as.
After the processing in step 71, the microcomputer 66 controls the electric motor 61 while executing the circulation processing including steps 72 to 78. In steps 72 to 74, the microcomputer 66 updates the old rear wheel steering angle θf OLD with the new front wheel steering angle θf NEW for each cycle processing, and the new front wheel steering angle θf
While updating NEW with the front wheel steering angle θf detected by the front wheel steering angle sensor 65 for each cycle, the calculation θ V = (θf
NEW- θf OLD ) / △ t by executing FW
The steering speed θ V of 1 and FW2 is calculated, and the vehicle speed V is updated with the vehicle speed detected by the vehicle speed sensor 64 every cycle processing. It should be noted that Δt in the above equation is calculated in steps 72 to 78.
It is the time required for one circulation process consisting of.

次に、このようにして設定した操舵速度θＶ及び車速
Ｖに基づき、マイクロコンピュータ66はステップ75,76
にて当該車両の高速走行中における左右前輪FW1,FW2の
操舵を検出する。すなわち、車速Ｖが所定車速VO以上で
ありかつ操舵速度θＶが所定操舵速度θVO以上であれ
ば、両ステップ75,76にて「YES」と判定されて、プログ
ラムはステップ77に進められる。また、それ以外の場合
には、両ステップ75,76のいずれかにて「NO」と判定さ
れて、プログラムはステップ78に進められる。ステップ
77においては、マイクロコンピュータ66は電動モータ61
を駆動制御して連結スリーブ32を第６図左方向へ移動さ
せる。また、ステップ78においては、マイクロコンピュ
ータ66は電動モータ61を駆動制御して連結スリーブ32を
第６図右方向へ移動させる。Next, based on the steering speed θ V and the vehicle speed V thus set, the microcomputer 66 executes steps 75 and 76.
Detects the steering of the left and right front wheels FW1, FW2 while the vehicle is traveling at high speed. That is, if the vehicle speed V is equal to or higher than the predetermined vehicle speed V O and the steering speed θ V is equal to or higher than the predetermined steering speed θ VO , it is determined to be “YES” in both steps 75 and 76, and the program proceeds to step 77. . In other cases, the determination is “NO” in either of steps 75 and 76, and the program proceeds to step 78. Step
In 77, the microcomputer 66 is an electric motor 61
Is controlled to move the connecting sleeve 32 to the left in FIG. In step 78, the microcomputer 66 drives and controls the electric motor 61 to move the connecting sleeve 32 to the right in FIG.

このようなステップ72〜78からなる循環処理の結果、
連結スリーブ32は、上記第２実施例の場合と同様、高速
走行中における左右前輪FW1,FW2の操舵時には第６図左
方向（車体に対し前方）に移動され、それ以外の場合に
は第６図右方向（車体に対し後方）に移動されるので、
この第３実施例においても上記第２実施例と同等な効果
が期待される。As a result of the cyclic processing including steps 72 to 78,
Similar to the case of the second embodiment, the connecting sleeve 32 is moved leftward in FIG. 6 (front of the vehicle body) when steering the left and right front wheels FW1 and FW2 during high-speed traveling, and in other cases, the sixth sleeve is used. Since it is moved to the right of the figure (to the rear of the vehicle),
Also in the third embodiment, the same effect as that of the second embodiment is expected.

d.その他の変形例 上記第１乃至第３実施例の伝達機構C1においては、連
結スリーブ32と出力軸31と相対的な回転変位を許容する
ことによって出力軸31の回転位相遅れを実現するように
したが、連結スリーブ32と入力軸28との相対的な回転変
位を許容することによって出力軸31の回転位相遅れを実
現するようにしてもよい。この場合、連結スリーブ32の
凸部32a及び入力軸28の大径部28aの溝28bを前方へいく
に従って幅が狭くなるように形成しておくとともに、連
結スリーブ32の凸部32b及び出力軸31の大径部31aの溝31
bを一定幅に形成しておき、左右前輪FW1,FW2の非操舵時
（又は低速走行時）には連結スリーブ32を前方へ移動さ
せておくようにし、かつ左右前輪FW1,FW2の操舵時（及
び高速走行時）には連結スリーブ32を後方へ移動させる
ように制御すればよい。d. Other Modifications In the transmission mechanism C1 of the first to third embodiments, the rotational phase delay of the output shaft 31 is realized by allowing the rotational displacement relative to the coupling sleeve 32 and the output shaft 31. However, the rotational phase delay of the output shaft 31 may be realized by allowing relative rotational displacement between the connecting sleeve 32 and the input shaft 28. In this case, the convex portion 32a of the connecting sleeve 32 and the groove 28b of the large diameter portion 28a of the input shaft 28 are formed so that the width becomes narrower toward the front, and the convex portion 32b of the connecting sleeve 32 and the output shaft 31 are formed. Groove 31 of large diameter part 31a of
b is formed to have a constant width, the connecting sleeve 32 is moved forward when the left and right front wheels FW1 and FW2 are not steered (or when traveling at low speed), and when the left and right front wheels FW1 and FW2 are steered ( And during high-speed traveling), the connecting sleeve 32 may be controlled to move rearward.

【図面の簡単な説明】[Brief description of drawings]

第１図は本発明の第１実施例に係る前後輪操舵車の全体
概略図、第２図は第１図の伝達機構及び制御装置の詳細
図、第３図は第２図の伝達機構の破断図、第4A図乃至第
4C図は第２図の伝達機構の作用説明図、第５図は本発明
の第２実施例に係る前後輪操舵車の部分図、第６図は本
発明の第３実施例に係る前後輪操舵車の部分図、並びに
第７図は第６図のマイクロコンピュータにて実行される
プログラムのフローチャートである。 符号の説明 Ａ……前輪操舵機構、Ｂ……後輪操舵機構、Ｃ……連結
装置、C1……伝達機構、C2……制御装置、FW1,FW2……
前輪、RW1,RW2……後輪、11……ハンドル、14……ラッ
クバー、17……制御バルブ、18……油圧ポンプ、21……
パワーシリンダ、23……変換器、24……リレーロッド、
27……トーションバー、28……入力軸、28b……溝、31
……出力軸、31b……溝、32……連結スリーブ、32a,32b
……凸部、36……シリンダ、37……スプリング、42……
フォーク、51……電磁切換え弁、52,64……車速セン
サ、53……電気制御回路、61……電動モータ、65……前
輪操舵角センサ、66……マイクロコンピュータ。FIG. 1 is an overall schematic view of a front and rear wheel steering vehicle according to a first embodiment of the present invention, FIG. 2 is a detailed view of a transmission mechanism and a control device of FIG. 1, and FIG. 3 is a transmission mechanism of FIG. Cutaway views, Figures 4A through 4
FIG. 4C is an explanatory view of the operation of the transmission mechanism of FIG. 2, FIG. 5 is a partial view of a front and rear wheel steering vehicle according to a second embodiment of the present invention, and FIG. 6 is a front and rear wheel according to a third embodiment of the present invention. FIG. 7 is a partial view of the steered vehicle, and FIG. 7 is a flowchart of a program executed by the microcomputer shown in FIG. Explanation of symbols A ... front wheel steering mechanism, B ... rear wheel steering mechanism, C ... coupling device, C1 ... transmission mechanism, C2 ... control device, FW1, FW2 ...
Front wheel, RW1, RW2 …… Rear wheel, 11 …… Handle, 14 …… Rack bar, 17 …… Control valve, 18 …… Hydraulic pump, 21 ……
Power cylinder, 23 …… converter, 24 …… relay rod,
27 ... torsion bar, 28 ... input shaft, 28b ... groove, 31
...... Output shaft, 31b …… Groove, 32 …… Coupling sleeve, 32a, 32b
...... Convex part, 36 …… Cylinder, 37 …… Spring, 42 ……
Fork, 51 …… electromagnetic switching valve, 52, 64 …… vehicle speed sensor, 53 …… electric control circuit, 61 …… electric motor, 65 …… front wheel steering angle sensor, 66 …… microcomputer.

Claims (1)

(57)【特許請求の範囲】(57) [Claims] 【請求項１】前端にて前輪操舵機構に接続され前輪の操
舵操作に応じた回転運動を後方に伝達する伝達機構と、
前記伝達機構の後端に接続され該伝達された回転運動を
左右後輪を操舵可能に連結したリレーロッドの往復運動
に変換して左右後輪を前輪の操舵に連動して操舵する後
輪操舵機構とを備えた前後輪操舵車の後輪操舵装置にお
いて、前記伝達機構を、前端にて前記前輪操舵機構に接
続され前輪の操舵操作に応じて回転する入力軸と、後端
にて前記後輪操舵機構に接続され前記入力軸の回転を前
記後輪操舵機構に伝達する出力軸と、前記入力軸の後端
部外周上及び前記出力軸の前端部外周上に渡り軸方向に
変位可能に組付けられるとともに該後端部外周面及び前
端部外周面との係合により基準軸方向位置にあるとき前
記入力軸と前記出力軸との相対的な回転変位を禁止しか
つ同基準軸方向位置から前記軸方向の一方への変位に応
じて前記入力軸と前記出力軸との相対的な許容回転変位
量を徐々に大きくする連結スリーブとにより構成すると
ともに、前記連結スリーブを前輪の操舵時に前記基準軸
方向位置から前記相対的な回転変位を許容する方向に変
位させる駆動手段を設けたことを特徴とする前後輪操舵
車の後輪操舵装置。1. A transmission mechanism, which is connected to a front wheel steering mechanism at a front end thereof and transmits a rotational movement rearward according to a steering operation of the front wheels,
Rear wheel steering that is connected to the rear end of the transmission mechanism and converts the transmitted rotational movement into reciprocating movement of a relay rod that connects the left and right rear wheels so that the left and right rear wheels can be steered in conjunction with steering of the front wheels. In the rear-wheel steering system for a front-and-rear-wheel steering vehicle including a mechanism, the transmission mechanism includes an input shaft that is connected to the front-wheel steering mechanism at a front end and that rotates in response to a steering operation of front wheels, and a rear end at the rear end. An output shaft that is connected to a wheel steering mechanism and transmits the rotation of the input shaft to the rear wheel steering mechanism, and is displaceable in the axial direction across the rear end outer circumference of the input shaft and the front end outer circumference of the output shaft. When assembled, it prohibits relative rotational displacement between the input shaft and the output shaft when in the reference axial direction position due to engagement with the rear end outer peripheral surface and the front end outer peripheral surface, and the same reference axial position. From the input shaft according to the displacement in one of the axial directions The connecting sleeve is configured to gradually increase the relative rotational displacement relative to the output shaft, and the connecting sleeve is arranged in a direction in which the relative rotational displacement is allowed from the reference axial direction position when steering the front wheels. A rear-wheel steering device for a front-rear wheel steering vehicle, comprising a drive means for displacing the front-rear wheel steering vehicle.
JP18156287A 1987-07-21 1987-07-21 Rear wheel steering system for front and rear wheel steering vehicles Expired - Lifetime JP2536534B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP18156287A JP2536534B2 (en) 1987-07-21 1987-07-21 Rear wheel steering system for front and rear wheel steering vehicles

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP18156287A JP2536534B2 (en) 1987-07-21 1987-07-21 Rear wheel steering system for front and rear wheel steering vehicles

Publications (2)

Publication Number Publication Date
JPS6428074A JPS6428074A (en) 1989-01-30
JP2536534B2 true JP2536534B2 (en) 1996-09-18

Family

ID=16102967

Family Applications (1)

Application Number Title Priority Date Filing Date
JP18156287A Expired - Lifetime JP2536534B2 (en) 1987-07-21 1987-07-21 Rear wheel steering system for front and rear wheel steering vehicles

Country Status (1)

Country Link
JP (1) JP2536534B2 (en)

Also Published As

Publication number Publication date
JPS6428074A (en) 1989-01-30

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