JPH0263973A - Rear-wheel steering mechanism - Google Patents
Rear-wheel steering mechanismInfo
- Publication number
- JPH0263973A JPH0263973A JP21617688A JP21617688A JPH0263973A JP H0263973 A JPH0263973 A JP H0263973A JP 21617688 A JP21617688 A JP 21617688A JP 21617688 A JP21617688 A JP 21617688A JP H0263973 A JPH0263973 A JP H0263973A
- Authority
- JP
- Japan
- Prior art keywords
- wheel steering
- rear wheel
- shaft
- valve
- valve element
- 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.)
- Granted
Links
- 230000007246 mechanism Effects 0.000 title claims abstract description 36
- 230000007935 neutral effect Effects 0.000 abstract description 37
- 238000006073 displacement reaction Methods 0.000 abstract description 10
- 230000033001 locomotion Effects 0.000 description 8
- 230000008859 change Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 230000009471 action Effects 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
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
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)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は４輪操舵車両の後輪操舵機構に関するものであ
る。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rear wheel steering mechanism for a four-wheel steering vehicle.
し従来の技術〕
特開昭５９−６１７１号公報に開示されるように、前輪
舵角に対応する電気信号を入力とする電子υ１ｔｌｌ装
置の出力により、サーボ制御弁ないし油量制御弁を駆動
し、これにより後輪操舵アクチュエータの油圧回路を制
御するとともに、後輪操舵アクチュエータの動作量を電
気的に検出して電子制御装置へフィードバックするもの
が知られている。この後輪操舵機構では、サーボ制御弁
ないし油量調節弁を駆動するために、前輪舵角に対応す
る機械的変位凹を電気量に変換し、この電気量に基づい
て回連とする後輪舵角を演算し、この演算結果に基づく
電気量をアクチュエータにより機械的変位惜に変換する
という制′ｎ動作を伴い、余分な電気ｌ−礪械吊変換が
加わり、構造が複雑であり、コストも高くなる。[Prior art] As disclosed in Japanese Unexamined Patent Publication No. 59-6171, a servo control valve or an oil flow control valve is driven by the output of an electronic υ1tll device that receives an electric signal corresponding to the front wheel steering angle as input. It is known that the hydraulic circuit of the rear wheel steering actuator is thereby controlled, and the amount of operation of the rear wheel steering actuator is electrically detected and fed back to an electronic control device. In this rear wheel steering mechanism, in order to drive a servo control valve or an oil flow control valve, the mechanical displacement corresponding to the front wheel steering angle is converted into an electrical quantity, and the rear wheels are rotated based on this electrical quantity. It involves a restrictive operation of calculating the steering angle and converting the electric quantity based on the calculation result into a mechanical displacement by an actuator, and an extra electric power-mechanical suspension conversion is added, making the structure complicated and increasing the cost. It also becomes more expensive.
一方、特開昭６１−１３２４６９号公報に開示される後
輪操舵機構では、前輪舵角の変化をケーブルを介して後
輪操舵アクチュエータのサーボ制御弁に連結しているの
で、電気的構成部材を含まない点でコストが節減される
が、前輪操舵部材と後輪操舵部材を連結するケーブルが
、後輪操舵の原動力となる力を伝達する役割を果すので
、高強度のケーブルが必要とされる。また、後輪操舵用
油圧を前輪操舵系から取り出しているので、後輪の操舵
時と非操舵時ではハンドルの操作力が変動し、運転者に
違和感を与える。On the other hand, in the rear wheel steering mechanism disclosed in Japanese Unexamined Patent Publication No. 61-132469, changes in the front wheel steering angle are connected to the servo control valve of the rear wheel steering actuator via a cable. Although the cost is saved by not including the front wheel steering member and the rear wheel steering member, a high-strength cable is required because the cable that connects the front wheel steering member and the rear wheel steering member plays the role of transmitting the force that is the driving force for rear wheel steering. . Furthermore, since the rear wheel steering hydraulic pressure is extracted from the front wheel steering system, the operating force of the steering wheel varies between when the rear wheels are being steered and when the rear wheels are not being steered, giving the driver a sense of discomfort.
［発明が解決しようとする問題点１
本発明の目的は身雑て高価な１子制叩装置を必要とせず
、機械的強度上に問題がなく、後輪操舵部材の動作が機
械的にフィードバックされる差動制御弁により、後輪操
舵アクチュエータが制御される後輪操舵Ｒ１Ｒを提供す
ることにある。[Problem to be Solved by the Invention 1] The purpose of the present invention is to eliminate the need for a complicated and expensive single-child control device, to avoid mechanical strength problems, and to provide mechanical feedback to the operation of the rear wheel steering member. An object of the present invention is to provide a rear wheel steering R1R in which a rear wheel steering actuator is controlled by a differential control valve.
［問題を解決するための手段１
上記目的を達成するために、本発明の構成は油圧源を差
動制御弁を経て後輪ナックルを駆動する後輪操舵アクチ
ュエータに接続し、ハンドルの切り角に関連しで回転す
る駆動軸により差ｉｏ制御弁の弁要素を往動し、後輪ナ
ックルにケーブルを介して運動連結する従動軸により弁
要素を復動させるようにしたものである。[Means for Solving the Problem 1] In order to achieve the above object, the configuration of the present invention connects a hydraulic power source to a rear wheel steering actuator that drives the rear wheel knuckle via a differential control valve, and adjusts the turning angle of the steering wheel. The valve element of the differential IO control valve is moved forward by a relatedly rotating drive shaft, and the valve element is moved backward by a driven shaft that is movably connected to the rear wheel knuckle via a cable.
［作用１
例えば、ハンドル４１を右へ切ると、前輪舵取は構３０
の出力軸２９に連ｖＪ連結する前輪ナックル３８が支軸
３４を中心として回動され、前輪４０が右へ隔向される
。同時に、出力軸２９に運動連結する＠１つの回転が直
接または舵角特性徐変機構Ａを介して、差動制御弁Ｂの
弁要素を往動させる駆動軸２４へ伝達される。油圧ポン
プ２６から圧油が管７２．７５、差動制御弁Ｂを経て、
管７６から後輪操舵アクチュエータＦの室８９へ入り、
ピストン５６と一緒にタイロッド６５が右へ駆動され、
後輪ナックル６つが支軸７０を中心として回動され、後
輪７１が左Ｉ＼偏向される。後輪操舵アクチュエータＦ
の室９′１の油は、管８０、差動制御弁Ｂ、管７９．７
７を経て油タンク２８へ戻される。[Effect 1 For example, when the steering wheel 41 is turned to the right, the front wheel steering is
A front wheel knuckle 38 connected to the output shaft 29 of the front wheel VJ is rotated about the support shaft 34, and the front wheel 40 is moved to the right. At the same time, the rotation of the output shaft 29 that is movably coupled to the output shaft 29 is transmitted directly or via the steering angle characteristic gradual change mechanism A to the drive shaft 24 that causes the valve element of the differential control valve B to move forward. Pressure oil from the hydraulic pump 26 passes through the pipe 72.75 and the differential control valve B.
enters the chamber 89 of the rear wheel steering actuator F from the pipe 76;
The tie rod 65 is driven to the right together with the piston 56,
The six rear wheel knuckles are rotated about the support shaft 70, and the rear wheel 71 is deflected to the left. Rear wheel steering actuator F
The oil in the chamber 9'1 is supplied to the pipe 80, the differential control valve B, and the pipe 79.7.
7 and is returned to the oil tank 28.
タイロッド６５が移動すると、この機械的変位量はケー
ブル５０を経て差動制御弁Ｂの弁要素を復動させる従動
軸６へ伝達される。こうして、差動制御弁Ｂの弁要素が
中立位置へ戻ると、管７５７９に対し管７６．８０が′
ａ断され、その位置に後輪操舵アクチュエータＦが停止
し、後輪７１がその舵角に保持される。When the tie rod 65 moves, this mechanical displacement is transmitted via the cable 50 to the driven shaft 6 which causes the valve element of the differential control valve B to move back. Thus, when the valve element of differential control valve B returns to the neutral position, pipe 76.80 is
a, the rear wheel steering actuator F stops at that position, and the rear wheels 71 are held at that steering angle.
差動制御弁Ｂの弁要素はハンドル操作に関連して駆動＠
２４により往動される一方、後輪のクイロッド６５にケ
ーブル５０を介して追随する従動軸６により復動される
。ケーブル５０は単に機械的変位量を伝達するだけで、
ケーブルに作用する荷重がごく小さく、強度負担が軽減
される。The valve element of differential control valve B is driven in relation to the handle operation.
24, and backward by a driven shaft 6 that follows a Quirod 65 of the rear wheel via a cable 50. The cable 50 merely transmits mechanical displacement;
The load acting on the cable is extremely small, reducing the strength burden.
［発明の実施例］
第１図は本発明に係る後輪操舵機構の概略構成図である
。本発明による後輪操舵機構は前輪舵取機構３０の出力
軸２つに関連して回転される駆動軸２４を有する差ａ制
御弁Ｂと、この差動制御弁Ｂを経て油圧ポンプ２６から
圧油を供給される後輪操舵アクチュエータＦと、後輪操
舵アクチュエータＦにより駆動されるタイロッド６５の
変位量を差動制御弁Ｂの従動軸６に伝達するケーブル５
０とを備えている。[Embodiments of the Invention] FIG. 1 is a schematic configuration diagram of a rear wheel steering mechanism according to the present invention. The rear wheel steering mechanism according to the present invention includes a differential a control valve B having a drive shaft 24 that is rotated in relation to two output shafts of the front wheel steering mechanism 30, and a hydraulic pump 26 that receives pressure through the differential control valve B. A cable 5 that transmits the displacement amount of the rear wheel steering actuator F supplied with oil and the tie rod 65 driven by the rear wheel steering actuator F to the driven shaft 6 of the differential control valve B.
0.
図示の実施例では、前輪舵角に対する後輪舵角を車速に
関連して制御するための舵角特性徐変機１ＭＡが、軸１
９と駆動軸２４の間に備えられ、軸′１つにスプライン
嵌合した制御部材２０の突片２２と駆動軸２４に結合し
た円筒部材２１の切欠２１ａとの相対位置を制御するア
クチュエータＤが、ｉ速に関連して油量を調整する油量
調整弁Ｅにより制御される。また、本発明による後輪操
舵機構には、後輪のタイロッド６５を中立位置に保持す
る中立ロック機構Ｈと、これを制御するアクチュエータ
Ｇが備えられる。In the illustrated embodiment, the steering angle characteristic gradual variable machine 1MA for controlling the rear wheel steering angle with respect to the front wheel steering angle in relation to the vehicle speed is configured to
9 and the drive shaft 24, and controls the relative position of the protrusion 22 of the control member 20 spline-fitted to one shaft ′ and the notch 21a of the cylindrical member 21 coupled to the drive shaft 24. , is controlled by an oil amount adjustment valve E that adjusts the oil amount in relation to speed i. Further, the rear wheel steering mechanism according to the present invention includes a neutral lock mechanism H that holds the rear wheel tie rod 65 in a neutral position, and an actuator G that controls the neutral lock mechanism H.
ハンドル４１を支持する操舵軸３７の回転は、公知の前
輪舵取機構３０の出力軸２つに伝達され、出力Ｉｄ１２
９と一緒に腕３−１．３２が回動される。The rotation of the steering shaft 37 that supports the handle 41 is transmitted to two output shafts of the known front wheel steering mechanism 30, and the output Id12
Arm 3-1.32 is rotated together with 9.
腕３２は前後方向のドラッグリンク３３と連結される。The arm 32 is connected to a drag link 33 in the front-rear direction.
ドラッグリンク３３の後端は、前輪４０を支持しかつ上
下方向の支＠３４により車体に支持された前輪ナックル
３８と連結される。前輪ナックル３８は左側前輪の同様
の前輪ナックル（図示−せｆ）とタイロッド３９により
運動連結される。The rear end of the drag link 33 is connected to a front wheel knuckle 38 that supports the front wheel 40 and is supported on the vehicle body by a vertical support @34. The front wheel knuckle 38 is movably connected to a similar front wheel knuckle of the left front wheel (FIG. 1-f) by a tie rod 39.
前輪舵取機構３０のイ８力１！置を駆動する油圧ポンプ
２７は、礪関により駆動される油圧ポンプ２６と連、情
される。Front wheel steering mechanism 30 has 8 forces and 1! The hydraulic pump 27 that drives the station is connected to the hydraulic pump 26 that is driven by the pump.
腕３１は前輪舵取機構３０のハウジングにブラケット１
６（第２図）により支持した軸１９の腕３６と、リンク
３５により運動連結される。軸１９にスプライン■合し
た制御部材２０の環状溝に制御レバー１８の一端部が係
合される。制御レバー１８を二股状のフォークとして環
状溝に係合してもよい。The arm 31 is attached to the bracket 1 on the housing of the front wheel steering mechanism 30.
It is connected in motion by a link 35 to an arm 36 of the shaft 19 supported by 6 (FIG. 2). One end of the control lever 18 is engaged in an annular groove in a control member 20 splined to the shaft 19. The control lever 18 may be a bifurcated fork that engages in the annular groove.
制御レバー１８は車体の固定部に軸１７により回動可能
に支持され、ばね１３の力により制御部材２０の突片２
２が円筒部材２１の切欠２１ａから軸方向に離れるよう
に回転付勢される〈第２図参照〉。制御レバー１８の他
端部はアクチュエータＤのピストンロッドと連結される
。第１図には理解を容易にするために、軸１７に結合し
た制御レバー１８ａにビスｉ〜ンロツドが連結され、ば
ね１３はアクチュエータＤのシリンダの内部に配設され
る。The control lever 18 is rotatably supported by a shaft 17 on a fixed part of the vehicle body, and the protrusion 2 of the control member 20 is rotated by the force of the spring 13.
2 is rotated and urged to move away from the notch 21a of the cylindrical member 21 in the axial direction (see FIG. 2). The other end of the control lever 18 is connected to the piston rod of the actuator D. In FIG. 1, for ease of understanding, a control lever 18a connected to a shaft 17 is connected to a screw rod, and a spring 13 is disposed inside the cylinder of an actuator D.
カップ形の円筒部材２１は周面に開口端側へ拡がりをも
つ楔形の切欠２１ａを設けられ、この切欠２１ａに突片
２２が当接すると、軸１９の回転が円筒部材２１へ伝達
され、この円筒部材２１と一緒に回転するようにスプラ
インまたはビンなどにより連結された駆動軸２４へ伝達
される。駆動軸２４は差動制御弁Ｂの弁要素を駆動する
ねじ部材にリードの大きなねじ溝で螺合される。軸１９
の回転に伴う切欠２１ａと突片２２の当接により円筒部
材２１の回転が駆動軸２４へ伝達されようとする時、駆
動軸２４は中立戻しばね１１４（第３図参照）により中
立位相を維持しようと抵抗するために、切欠２１ａと突
片２２の当接部において楔形の切欠２１ａの傾斜角に見
合った軸推力が発生する。The cup-shaped cylindrical member 21 is provided with a wedge-shaped notch 21a that widens toward the open end on its circumferential surface, and when the protruding piece 22 comes into contact with this notch 21a, the rotation of the shaft 19 is transmitted to the cylindrical member 21. The signal is transmitted to a drive shaft 24 connected to the cylindrical member 21 by splines, pins, etc. so as to rotate together with the cylindrical member 21 . The drive shaft 24 is screwed into a threaded member that drives the valve element of the differential control valve B through a threaded groove with a large lead. Axis 19
When the rotation of the cylindrical member 21 is about to be transmitted to the drive shaft 24 due to the contact between the notch 21a and the protrusion 22 due to the rotation, the drive shaft 24 maintains the neutral phase by the neutral return spring 114 (see FIG. 3). In order to resist this movement, an axial thrust corresponding to the inclination angle of the wedge-shaped notch 21a is generated at the contact portion between the notch 21a and the protruding piece 22.
円筒部材２１と駆動軸２４はスプラインまたはビンなど
により軸方向移動を許容されているので、切欠２１ａと
突片２２の当接により軸１９の回転が円筒部材２１へ伝
達されるのに先立って、まず円筒部材２１が駆動軸２４
との軸方向移０許容檄（隙間Ｓ）だけ移動し、その後に
回転が伝）７される。この時、円筒部材２１のごく僅か
な軸方向移動は、円筒部材２１の端壁に対設したスイッ
チ２３により検出される。このスイッチ２３は後ｊホす
る中立ロック機構Ｈを制御する。Since the cylindrical member 21 and the drive shaft 24 are allowed to move in the axial direction by a spline or a pin, etc., before the rotation of the shaft 19 is transmitted to the cylindrical member 21 by the contact between the notch 21a and the protrusion 22, First, the cylindrical member 21 is connected to the drive shaft 24.
It moves by the allowable axial displacement (gap S), and then rotation is transmitted)7. At this time, a very slight axial movement of the cylindrical member 21 is detected by a switch 23 provided opposite to the end wall of the cylindrical member 21. This switch 23 controls the neutral locking mechanism H that follows.
アクチュエータＤはシリンダの内部に嵌装したピストン
により、油圧が導入される端室と、ばね１３を収容する
大気宇とを区画される。アクチユ工−りＤの端室へ油圧
ポンプ２６から圧油が油量調整弁Ｅを経て供給される。The actuator D is partitioned into an end chamber into which hydraulic pressure is introduced and an atmospheric chamber in which the spring 13 is housed, by a piston fitted inside the cylinder. Pressure oil is supplied from the hydraulic pump 26 to the end chamber of the actuator D via the oil amount adjustment valve E.
油量調整弁Ｅは３つのボートを有するハウジング４６の
内部に、２つの環状溝を有するスプール４８を嵌合して
なり、ばね４９を収容する左側の端室と中央のボートと
がアクチュエータＤの端室と連通される。中立位置でス
プール４８の環状溝に連通するボートの一方が油圧ポン
プ２６に、他方が油タンク２８に連通される。スプール
４８に結合したロンドはハウジング４６の外部へ突出し
てアマチュアを構成し、電磁コイル４７の電流に対応し
て左方への付勢力を受ける。The oil amount adjusting valve E is constructed by fitting a spool 48 having two annular grooves into a housing 46 having three boats. It communicates with the end chamber. One side of the boat that communicates with the annular groove of the spool 48 in the neutral position is communicated with the hydraulic pump 26, and the other side is communicated with the oil tank 28. The rond coupled to the spool 48 protrudes to the outside of the housing 46 to form an armature, and receives a biasing force to the left in response to the current of the electromagnetic coil 47.
電磁コイル４７は車速が低いと電流が大ぎく、車速か高
くなるほど電流が小さくなるように制御される。このた
め、変速機の出力軸の回転を速度計１５へ伝達する可撓
軸４３に、歯車機構４２を介して車速比例電流発生器４
４が結合される。車速比例電流発生器４４の両端子は電
流減蓮変換器４５に接続され、電源バッテリ５１から電
磁コイル４７へのＮ流を制御する。The electromagnetic coil 47 is controlled so that the current is large when the vehicle speed is low, and the current is small as the vehicle speed increases. Therefore, a vehicle speed proportional current generator 4 is connected to a flexible shaft 43 that transmits the rotation of the output shaft of the transmission to the speedometer 15 via a gear mechanism 42.
4 are combined. Both terminals of the vehicle speed proportional current generator 44 are connected to a current reduction converter 45 to control the N current from the power source battery 51 to the electromagnetic coil 47 .
差動制御弁Ｂは中立位置開放型でもよいが、好ましくは
４ボート・中立位置ブロック型の方向切換弁であり、駆
動軸２４の回転に伴って一方の弁要素が軸方向、に移動
し、従動軸６に結合した他方の弁要素との間に相対移動
が生じると、油圧ポンプ２６から圧油が管７２．７５を
経て管７６．８０の一方へ供給され、他方の管の油が管
７９．７７を経て油タンク２８へ戻される。管７６．８
０は特殊な逆止弁５３．５４を軽で後輪操舵アクチュエ
ータＦの両端室８９．９１と連通される。The differential control valve B may be a neutral position open type, but is preferably a four-boat/neutral position block type directional switching valve, in which one valve element moves in the axial direction as the drive shaft 24 rotates, When a relative movement occurs between the driven shaft 6 and the other valve element, pressure oil is supplied from the hydraulic pump 26 via pipes 72.75 to one of the pipes 76.80, and oil in the other pipe is supplied to the pipe 76.80. It is returned to the oil tank 28 through 79.77. tube 76.8
0 communicates with both end chambers 89,91 of the rear wheel steering actuator F through special check valves 53,54.
第３図は差動制御弁Ｂの平面断面図である。車体に固定
されるハウジング１２１の内部へ嵌合した円筒形の弁ハ
ウジング１２２の内周面中央に、管７５に連通ずる環状
溝１２４が、この両側に環状溝１２３．１２５がそれぞ
れ設けられる。また、弁ハウジング１２２の環状溝１２
４の両側に径方向の通路１２７ａ、１２８ａが設けられ
る。弁ハウジング１２２に摺動可能に嵌装される弁要素
としてのスプール１２６は、外周面に前述の通路１２７
ａ、１２８ａに対向する環状溝１２７，１２８が設けら
れ、さらに両端側に前述の環状溝１２３．１２５に対向
する径方向の通路１２３ａ、１２５ａが設けられる。FIG. 3 is a plan sectional view of the differential control valve B. FIG. An annular groove 124 communicating with the pipe 75 is provided at the center of the inner peripheral surface of a cylindrical valve housing 122 fitted inside a housing 121 fixed to the vehicle body, and annular grooves 123 and 125 are provided on both sides of the annular groove 124, respectively. Additionally, the annular groove 12 of the valve housing 122
4 are provided with radial passages 127a, 128a on both sides. A spool 126 as a valve element that is slidably fitted into the valve housing 122 has the aforementioned passage 127 on its outer peripheral surface.
Annular grooves 127, 128 are provided opposite to the annular grooves 123, 128a, and radial passages 123a, 125a are provided at both ends thereof, opposing the aforementioned annular grooves 123, 125.
スプール１２６の左端面に固定した当て板１３７とハウ
ジング１２１の段部に衝合したばね座と、弁ハウジング
１２２とスプール１２６の各段部に衝合したばね座との
間に、センタリングばね１３８が介装される。また、ね
じ部材１３０にナツト１３５により固定した座板１３４
と当て板１３７に衝合するばね座と、スプール１２６と
ねじ部材１３０の各段部に衝合したばね座との間に、オ
ーバストローク吸収用ばね１３６が介装される。A centering spring 138 is installed between a backing plate 137 fixed to the left end surface of the spool 126, a spring seat that abuts against the stepped portion of the housing 121, and a spring seat that abuts against each step of the valve housing 122 and the spool 126. Intervened. Also, a seat plate 134 fixed to the screw member 130 with a nut 135
An overstroke absorbing spring 136 is interposed between a spring seat that abuts against the backing plate 137 and a spring seat that abuts each step of the spool 126 and the screw member 130.
ハウジング１２１に回転可能に嵌合した中空の駆動軸２
４に、前述の円筒部材２１が嵌合される。Hollow drive shaft 2 rotatably fitted into housing 121
4, the aforementioned cylindrical member 21 is fitted.
駆動軸２４の７ランジ２４ａと円筒部材２１のフランジ
２１ｂがビン１３９により一緒に回転し、カリ円筒部材
２１の軸方向に隙間Ｓだけ移動可能に連結される。円筒
部材２１はばね１１５により駆動軸２４に対し軸方向へ
押され、ハウジング１２１に当接している。この時、切
欠２１ａの斜面がスイッチ２３を押して１回路を開いて
いる。ビン１３９とハウジング１２１に固定したビン１
４０との間に中立戻しばね（捩りばね）１１４が介装さ
れ、この中立戻しばね１１４により駆動軸２４の回転位
相が中立位置へ回転付勢される。The seven flange 24a of the drive shaft 24 and the flange 21b of the cylindrical member 21 rotate together by a pin 139, and are connected so as to be movable by a gap S in the axial direction of the pot cylindrical member 21. The cylindrical member 21 is pushed in the axial direction with respect to the drive shaft 24 by the spring 115 and is in contact with the housing 121. At this time, the slope of the notch 21a pushes the switch 23 and opens one circuit. Bin 1 fixed to bin 139 and housing 121
A neutral return spring (torsion spring) 114 is interposed between the drive shaft 24 and the drive shaft 24, and the neutral return spring 114 rotationally biases the rotational phase of the drive shaft 24 to the neutral position.
駆動軸２４の内端部に設けたリードの大きなねじ穴１３
１に、円筒形のねじ部材１３０が螺合される。ねじ部材
１３０の内空部は適当な手段により油タンク２８に接続
される一方、径方向の通路１３３、通路１２３ａを経て
環状溝１２３に連通し、また通路１２５ａを経て環状溝
１２５にも連通ずる。ねじ部材１３０に設けたスプライ
ン穴１３２に、従動軸６のスプライン軸部が嵌合される
。A large lead screw hole 13 provided at the inner end of the drive shaft 24
1, a cylindrical screw member 130 is screwed together. The inner cavity of the threaded member 130 is connected to the oil tank 28 by suitable means, while communicating with the annular groove 123 via a radial passage 133 and a passage 123a, and also with the annular groove 125 via a passage 125a. . A spline shaft portion of the driven shaft 6 is fitted into a spline hole 132 provided in the screw member 130 .
図示の中立位置では、スプール１２６の環状溝１２７の
両側縁は弁ハウジング１２２の環状溝１２４の側縁と環
状溝１２３の側縁とにごく僅かな隙間を存して接し、同
様に環状溝１２８の両側縁は環状溝１２４の側縁と環状
溝１２５の側縁とにごく僅かな隙間を存して接し、各隙
間の量がほぼ同量であるので、圧油は管７６と管８０の
何れにも均等に油圧を加えることとなり、後輪操舵アク
チュエータＦは室８９．９１の油圧が平衡してピストン
は移動しない。In the illustrated neutral position, both side edges of the annular groove 127 of the spool 126 touch the side edges of the annular groove 124 and the annular groove 123 of the valve housing 122 with a very small gap, and similarly the annular groove 128 The side edges of the annular groove 124 and the annular groove 125 are in contact with the side edges of the annular groove 124 and the annular groove 125 with very small gaps between them, and since the amount of each gap is almost the same, the pressure oil flows through the pipes 76 and 80. Hydraulic pressure is applied equally to both, and the hydraulic pressure in the chambers 89 and 91 of the rear wheel steering actuator F is balanced, and the piston does not move.
なお、各隙間から洩れ出た管７５の圧油は管７６．８０
に均等の圧力を加えながら、通路１２３ａ、１２５ａを
経て管７９へ入り、管７７を経て油タンク２８へ戻る。In addition, the pressure oil leaking from the pipe 75 from each gap is contained in the pipe 76.80.
While applying equal pressure to the oil, it enters the pipe 79 through the passages 123a and 125a, and returns to the oil tank 28 through the pipe 77.
駆動軸２４が回転されると、その回転力はねじ穴１３１
に螺合するねじ部材１３０に伝達され、ねじ部材１３０
の回転はスプライン穴１３２を経て従動軸６へ伝達され
る。しかし、駆動軸２４の回転量に対応した後輪ナック
ルの動きがないと従動軸６は回転しないので、駆動軸２
４から従動軸６に至る回転伝達経路のねじ穴１３１にお
いて、ねじのリード角に見合った軸推力がねじ部材１３
０に発生する。ねじ部材１３０に生じた軸推力によりセ
ンタリングばね１３８の力に抗してねじ部材１３０と一
体的にスプール１２６が例えば右方へ移動すると、管７
５の圧油が環状溝１２４、環状溝１２７、通路１２７ａ
を経て管７６へ流れる。When the drive shaft 24 is rotated, the rotational force is applied to the screw hole 131.
The transmission is transmitted to the screw member 130 that is screwed into the screw member 130 .
The rotation is transmitted to the driven shaft 6 through the spline hole 132. However, the driven shaft 6 will not rotate unless the rear wheel knuckle moves in accordance with the amount of rotation of the drive shaft 24.
4 to the driven shaft 6, an axial thrust commensurate with the lead angle of the screw is applied to the screw member 13.
Occurs at 0. When the spool 126 moves, for example, to the right together with the screw member 130 against the force of the centering spring 138 due to the axial thrust generated in the screw member 130, the pipe 7
No. 5 pressure oil is connected to the annular groove 124, the annular groove 127, and the passage 127a.
and into pipe 76.
方、管８０の油は通路１２８ａ、環状１ｍ１２８、環状
溝１２５、通路１２５ａ、通路１３３を経てねじ部材１
３０の内空部へ流れ、さらに図示してない通路を経て油
タンク２８へ戻される。逆に、スプール１２６が左方へ
移動すると、管７５が管８０に連通され、管７６がねじ
部材１３０の内空部へ連通される。On the other hand, the oil in the pipe 80 passes through the passage 128a, the annular 1 m 128, the annular groove 125, the passage 125a, and the passage 133 to the threaded member 1.
30 and is further returned to the oil tank 28 via a passage (not shown). Conversely, when the spool 126 moves to the left, the tube 75 is communicated with the tube 80, and the tube 76 is communicated with the inner cavity of the threaded member 130.
上述のように、管７５の圧油が管７６と管８０の一方に
流れると、後述の後輪操舵アクチュエータＥによりタイ
ロッド６５が駆動され、これに伴ってケーブル５０を介
して従動軸６が回転する。As described above, when the pressure oil in the pipe 75 flows into one of the pipes 76 and 80, the tie rod 65 is driven by the rear wheel steering actuator E, which will be described later, and the driven shaft 6 is accordingly rotated via the cable 50. do.
ねじ部材１３０が駆動軸２４と同方向に回転することに
より両者の相対回転位相差が減少し、スプール１２６が
中立位置へ戻される。この時、ハンドル４１の切り角に
対応した舵角に後輪７１が保持される。By rotating the screw member 130 in the same direction as the drive shaft 24, the relative rotational phase difference between the two is reduced, and the spool 126 is returned to the neutral position. At this time, the rear wheels 71 are held at a steering angle corresponding to the turning angle of the steering wheel 41.
第４図に示すように、後輪操舵アクチュエータＦはアク
スルハウジング８４に取付部材８５により支持される。As shown in FIG. 4, the rear wheel steering actuator F is supported by a mounting member 85 on the axle housing 84. As shown in FIG.
タイロッド６５の両端が球継手６６により補助ロッド６
７と連結され、補助ロッド６７は後輪７１を支持する後
輪ナックル６９と球継手６８により連結される。公知の
ように、差動Ｒ８４ａを結合するアクスルハウジング８
４の両端は板ばね８３により車枠８１に支持される。板
ばね８３は前端部の目玉部を車枠８１のブラケット８２
にビンにより連結される一方、後端部をシャックルと連
結され、このシャックルが車枠８１のブラケット８６に
ビンにより連結される。アクスルハウジング８４に支持
された車軸は等速自在継手により、後輪ナックル６９に
支持された後輪７１の軸と連結される。後輪ナックル６
９は２分割された上下方向の支軸７０（第１図）により
アクスルハウジング８４の端部に回動可能に支持される
。Both ends of the tie rod 65 are connected to the auxiliary rod 6 by a ball joint 66.
The auxiliary rod 67 is connected to a rear wheel knuckle 69 that supports the rear wheel 71 by a ball joint 68. As is known, the axle housing 8 that connects the differential R84a
Both ends of 4 are supported by the vehicle frame 81 by leaf springs 83. The leaf spring 83 connects the eye of the front end to the bracket 82 of the vehicle frame 81.
The rear end portion is connected to a shackle by a pin, and the shackle is connected to a bracket 86 of the vehicle frame 81 by a pin. The axle supported by the axle housing 84 is connected to the shaft of the rear wheel 71 supported by the rear wheel knuckle 69 by a constant velocity universal joint. rear wheel knuckle 6
9 is rotatably supported at the end of the axle housing 84 by a vertical support shaft 70 (FIG. 1) that is divided into two parts.
第５図に示すように、後輪操舵アクチュエータＦはシリ
ンダ５７にピストン５６を嵌合して室８９９１を区画さ
れる。ピストン５６に結合したタイロッド６５がシリン
ダ５７の両＠壁９２．９３に摺動可能に支持される。ビ
ス１〜ン５Ｇを中立位置（後輪の直進位＠）に戻すため
に、タイロッド６５に係止した止め輪８８に当接するば
ね座８７と、ピストン５６に当接するばね座９０との間
にばね５５が介装される。円筒形のばね座８７は端部フ
ランジを端壁９２に当接される。円筒形のばね座９０も
端部フランジをシリンダ５７の中間壁９８に当接される
。管７６と室８９とを結ぶ端壁９２の通路に逆止弁５３
が、管８０とｖ９１に連なる管８０ｂとを結ぶ中間壁９
８に逆止弁５４がそれぞれ配設される。逆止弁５３，５
４は同じ構成のものである。As shown in FIG. 5, the rear wheel steering actuator F has a cylinder 57 fitted with a piston 56 to define a chamber 8991. A tie rod 65 connected to the piston 56 is slidably supported on both walls 92,93 of the cylinder 57. In order to return the screws 1 to 5G to the neutral position (straight forward position of the rear wheel), a spring seat 87 that comes into contact with a retaining ring 88 that is engaged with the tie rod 65 and a spring seat 90 that comes into contact with the piston 56 are installed. A spring 55 is interposed. A cylindrical spring seat 87 has an end flange abutted against an end wall 92 . A cylindrical spring seat 90 also bears with its end flange against the intermediate wall 98 of the cylinder 57 . A check valve 53 is provided in the passageway of the end wall 92 connecting the pipe 76 and the chamber 89.
is the intermediate wall 9 connecting the pipe 80 and the pipe 80b connected to v91.
A check valve 54 is provided at 8, respectively. Check valve 53,5
4 has the same configuration.
第６図に示すように、端壁９３はタイロッド６５を中立
位置にロックする中立ロック機構Ｈのハウジング９４と
一体に構成される。ハウジング９４の内部において、タ
イロッド６５に円錐形の穴６０または環状溝を備えた受
入部材５８が結合され、かつハウジング９４に沿って摺
動可能に案内される。一方、ハウジング９４にスイッチ
６２を備えたアクチュエータＧが固定される。アクチュ
エータＧはシリンダ６３にピストン６４を嵌合して下側
に室９６を、上側にばね６１を収容する大気室を区画さ
れる。ピストン６４に結合したロック部材５９が、ハウ
ジング９４の壁部を貫通して受入部材５８の円錐穴６ｏ
に係合可能とされる。As shown in FIG. 6, the end wall 93 is constructed integrally with a housing 94 of a neutral locking mechanism H that locks the tie rod 65 in the neutral position. Inside the housing 94 , a receiving member 58 with a conical hole 60 or an annular groove is connected to the tie rod 65 and is slidably guided along the housing 94 . On the other hand, an actuator G including a switch 62 is fixed to the housing 94. The actuator G has a piston 64 fitted into a cylinder 63 to define a chamber 96 on the lower side and an atmospheric chamber accommodating the spring 61 on the upper side. A locking member 59 coupled to the piston 64 passes through the wall of the housing 94 and is inserted into the conical hole 6o of the receiving member 58.
can be engaged with.
室９６に管７４から圧油を供給すると、ロック部材５つ
が押し上げられ、受入部材５８との係合が解除される。When pressure oil is supplied to the chamber 96 from the pipe 74, the five locking members are pushed up and the engagement with the receiving member 58 is released.
ロック解除動作を検出するスイッチ６２は、可動接片６
２ａをピストン６４に当接され、ピストン６４が図示の
ロック位置から解除方向に移動し始めると、すぐ回路を
閉じる。A switch 62 that detects a lock release operation is a movable contact piece 6
2a is brought into contact with the piston 64, and as soon as the piston 64 begins to move from the illustrated locking position in the release direction, the circuit is immediately closed.
第７図は逆止弁５３の構成を示す断面図である。FIG. 7 is a sectional view showing the structure of the check valve 53.
端壁９２に管７６に連通する通路と交差して管８０ａに
連通するシリンダ１０２と、室８９に連通する弁孔１０
６とが形成される。シリンダ１０２に嵌合したピストン
１０４は管８０ａと管７６との間を遮断し、シリンダ１
０２に油圧が作用すると、弁孔１０６に嵌合したステム
１０７に当接するロッド１０５により弁体１０８が端壁
９２から押し離される。弁体１０８を支持するステム１
０７は、管７６と至８９を連通する軸方向溝を備えてい
る。弁体１０８から室８９△、突出するステム１１１に
ばね座１１０が摺動可能に嵌合され、かつ止め輪１０３
ａによりステム１１１から扱けないように支持される。A cylinder 102 that intersects the passage communicating with the pipe 76 and communicates with the pipe 80a is provided in the end wall 92, and a valve hole 10 that communicates with the chamber 89.
6 is formed. The piston 104 fitted into the cylinder 102 blocks the pipe 80a and the pipe 76, and the piston 104 fits into the cylinder 102.
When hydraulic pressure is applied to valve 02, valve element 108 is pushed away from end wall 92 by rod 105 that abuts stem 107 fitted in valve hole 106. Stem 1 supporting valve body 108
07 is provided with an axial groove that communicates between the tube 76 and the to 89. A spring seat 110 is slidably fitted to a stem 111 protruding from the chamber 89Δ from the valve body 108, and the retaining ring 103
a so that it cannot be handled from the stem 111.
弁体１０８とばね座１１０との間にばね１１２が介装さ
れる。このばね１１２により弁体１０８が端壁９２へ押
し付けられる。A spring 112 is interposed between the valve body 108 and the spring seat 110. This spring 112 presses the valve body 108 against the end wall 92 .
ばね座８７が右方へ移動すると、ばね座１１０と端壁９
２との間に介装したばね１０９により、弁体１０８は端
壁９２から離れる。When the spring seat 87 moves to the right, the spring seat 110 and the end wall 9
2, the valve body 108 is separated from the end wall 92.
第１図に示すように、中立ロック機構Ｈの受入部材５８
にケーブル５０の一端が連結され、他端は第２図に示す
クラッチ板つと一体のレバー９ａと連結される。ケーブ
ル５０は一端を車体側に、他端を後輪操舵アクチュエー
タＦのハウジング５７にそれぞれ固定したアウタチュー
ブく図示せず）に挿通され、受入部材５８を支持するタ
イロッド６５の変位闇をレバー９ａに伝達する。第２図
に示すように、車体に軸４により回動可能に支持したベ
ルクランク１０とレバー９ａとの間にばね５が掛は渡さ
れ、このばね５によりベルクランク１０がストッパ１１
に当接されるとともに、レバー９ａが回動されてケーブ
ル５ｏが弛みのないように緊張される。As shown in FIG. 1, the receiving member 58 of the neutral locking mechanism H
One end of the cable 50 is connected to the lever 9a, and the other end is connected to a lever 9a integrated with the clutch plate shown in FIG. The cable 50 is inserted into an outer tube (not shown) that has one end fixed to the vehicle body side and the other end fixed to the housing 57 of the rear wheel steering actuator F, and is connected to the lever 9a by the displacement of the tie rod 65 that supports the receiving member 58. introduce. As shown in FIG. 2, a spring 5 is applied between a lever 9a and a bell crank 10 rotatably supported on the vehicle body by a shaft 4.
At the same time, the lever 9a is rotated and the cable 5o is tightened so that it does not become loose.
万一、ケーブル５０が折損すると、ベルクランク１０と
車体との間に掛は渡した弱いばね１２により、ベルクラ
ンク１０が軸４を中心として回動され、リンクロッド３
により後述する油圧回路の常閉型の開閉弁２（第１図）
が開かれる。In the unlikely event that the cable 50 is broken, the bell crank 10 is rotated about the shaft 4 by the weak spring 12 that is passed between the bell crank 10 and the vehicle body, and the link rod 3
A normally closed on-off valve 2 (Fig. 1) of a hydraulic circuit, which will be described later.
will be held.
レバー９ａはクラッチ板９と一体をなし、従動軸６に遊
回転回能に支持される。電磁クラッチＣの電磁コイル８
が励磁されると、クラッチ板９が従動軸６に結合した円
板７に摩擦係合され、レバー９ａの回動が従動軸６へ伝
達される。The lever 9a is integral with the clutch plate 9 and supported by the driven shaft 6 for free rotation. Electromagnetic coil 8 of electromagnetic clutch C
When the clutch plate 9 is excited, the clutch plate 9 is frictionally engaged with the disk 7 connected to the driven shaft 6, and the rotation of the lever 9a is transmitted to the driven shaft 6.
第１図に示すように、中立ロック機構Ｈを解除するアク
チュエータＧを駆動するために、油圧ポンプ２６の吐出
口は管７２，７３、電磁切換弁５２、管７４を経てアク
チュエータＧの室９６に連通される。中立ロック機構Ｈ
をロックする時、室９６は管７４、電磁切換弁５２、管
７８．７７を経て油タンク２８と連通される。電磁切換
弁５２は舵角特性徐変機構Ａの円筒部材２１の作動を検
出するスイッチ２３と運動して切り換えられる。As shown in FIG. 1, in order to drive the actuator G that releases the neutral lock mechanism H, the discharge port of the hydraulic pump 26 is connected to the chamber 96 of the actuator G via pipes 72, 73, the electromagnetic switching valve 52, and the pipe 74. communicated. Neutral lock mechanism H
When locked, the chamber 96 is communicated with the oil tank 28 via the pipe 74, the electromagnetic switching valve 52, and the pipes 78 and 77. The electromagnetic switching valve 52 is switched by movement with the switch 23 that detects the operation of the cylindrical member 21 of the steering angle characteristic gradual change mechanism A.
車速が所定値（例えば２０ｋｍ／ｈ）を超えた時、後輪
操舵機構の油圧回路を開放して中立位置へ戻すために、
ｍ源バッテリ５１に対し、管７２と管７７の間に挿入接
続した常閉型の電磁開閉弁２５と、速度計１５の針が所
定値を超えた時閉じるスイッチ１４とが直列に接続され
る。When the vehicle speed exceeds a predetermined value (for example, 20 km/h), the hydraulic circuit of the rear wheel steering mechanism is opened to return it to the neutral position.
A normally closed electromagnetic on-off valve 25 inserted and connected between pipes 72 and 77 and a switch 14 that closes when the needle of the speedometer 15 exceeds a predetermined value are connected in series to the m-source battery 51. .
次に、本発明による後輪操舵機構の作動について説明す
る。例えばハンドル４１を右へ切ると、前輪舵取機構３
０の出力軸２９が回動され、腕３２によりドラッグリン
ク３３が前方へ引かれ、前輪ナックル３８が支軸３４を
中心として時計方向へ回動され、前輪４０が右へ偏向さ
れる。同時に、出力軸２９の回動が軸１９へ伝達され、
この時車速が所定値以下にあり、前輪舵角が所定値を超
えると、突片２２が円筒部材２１の切欠２１ａに当接し
、駆動軸２４が矢印方向へ回転される。同時に、スイッ
チ２３が閉じ、電磁切換弁５２が管７３と管７４を連通
する状態に切り換わる。Next, the operation of the rear wheel steering mechanism according to the present invention will be explained. For example, when the steering wheel 41 is turned to the right, the front wheel steering mechanism 3
0 output shaft 29 is rotated, the drag link 33 is pulled forward by the arm 32, the front wheel knuckle 38 is rotated clockwise about the support shaft 34, and the front wheel 40 is deflected to the right. At the same time, the rotation of the output shaft 29 is transmitted to the shaft 19,
At this time, when the vehicle speed is below a predetermined value and the front wheel steering angle exceeds a predetermined value, the protrusion 22 comes into contact with the notch 21a of the cylindrical member 21, and the drive shaft 24 is rotated in the direction of the arrow. At the same time, the switch 23 is closed, and the electromagnetic switching valve 52 is switched to a state where the pipes 73 and 74 are communicated with each other.
電磁切換弁５２が切り換わると、油圧ポンプ２６の圧油
が管７２，７３．７４を経てアクチュエータＧの室９６
へ供給され、ピストン６４が上方ｌ＼移動し、ロック部
材５つがタイロッド６５の受入部材５８から外れる。こ
の時、スイッチ６２が閉じ、電源バッテリ５１から電磁
クラッチＣ、スイッチ６２へ通電される。When the electromagnetic switching valve 52 is switched, the pressure oil from the hydraulic pump 26 flows through the pipes 72, 73, and 74 to the chamber 96 of the actuator G.
is supplied, the piston 64 moves upward l\, and the five locking members are disengaged from the receiving member 58 of the tie rod 65. At this time, the switch 62 is closed, and power is supplied from the power source battery 51 to the electromagnetic clutch C and the switch 62.
方、差動ｉｌｌ Ｉ弁Ｂにおいて、弁要素の軸移動が生
じ、管７５が管７６に、管７９が管８０にそれぞれ連通
する。後輪操舵アクチュエータＥの字８９に圧油が供給
され、室９１の油は油タンク２８１＼戻される。タイロ
ッド６５が右方へ移動し、後輪ナックル６９が支軸７０
を中心として反時計方向に回動し、後輪７１が左（前輪
と反対方向）へ偏向される。こうして、車両の低速走行
での小回り性が向上される。On the other hand, in the differential ill I valve B, an axial movement of the valve element occurs, and the pipe 75 communicates with the pipe 76 and the pipe 79 communicates with the pipe 80, respectively. Pressure oil is supplied to the rear wheel steering actuator E-shaped 89, and the oil in the chamber 91 is returned to the oil tank 281\. The tie rod 65 moves to the right, and the rear wheel knuckle 69 moves to the support shaft 70.
The rear wheel 71 is rotated counterclockwise around , and the rear wheel 71 is deflected to the left (in the opposite direction to the front wheel). In this way, the turning ability of the vehicle when traveling at low speeds is improved.
タイロッド６５の右移動はケーブル５０を経てクラッチ
板つと一体のレバー９ａに伝達され、従動軸６を回転さ
せる。作動制御弁Ｂの弁要素が中立位置に至ったところ
で、管７５が管７６から遮断され、管８０が管７つから
遮断されるので、後輪操舵アクチュエ〜りＦはその位１
に停止する。The rightward movement of the tie rod 65 is transmitted via the cable 50 to the lever 9a integrated with the clutch plate, thereby rotating the driven shaft 6. When the valve element of the actuation control valve B reaches the neutral position, the pipe 75 is cut off from the pipe 76 and the pipe 80 is cut off from the pipes 7, so that the rear wheel steering actuator
Stop at.
上述のように、ハンドル４１の切り角に対応して後輪操
舵アクチュエータＦが作動し、後輪７１が操舵される。As described above, the rear wheel steering actuator F operates in accordance with the turning angle of the steering wheel 41, and the rear wheels 71 are steered.
前輪４０の舵角に対する後輪７１の舵角は第８図に線ａ
１で表される。ここで、車速が増加すると、舵角特性徐
変機構への作用によりハンドル４１がその切り角に保持
されている場合でも、第８図の線ａ２の方へ乗り移り、
後輪舵角が小さくなる。つまり、突片２２を支持する制
御部材２０が軸１９に対して右方へ移動し、突片２２と
切欠２１ａとの間に隙間が生じるので、中立戻しばね〈
図示せず〉の作用により円筒部材２１が逆方向に回動し
、差動制御弁Ｂの弁要素に軸移動が生じ、管７５が管８
０に、管７９が管７６にそれぞれ連通され、後輪操舵ア
クチュエータＦによりタイロッド６５が左方へ移動し、
後輪７１の舵角が小さくなる。The steering angle of the rear wheels 71 relative to the steering angle of the front wheels 40 is shown by line a in FIG.
It is represented by 1. Here, when the vehicle speed increases, even if the steering wheel 41 is held at the steering angle due to the action on the steering angle characteristic gradual change mechanism, it shifts toward the line a2 in FIG.
The rear wheel steering angle becomes smaller. In other words, the control member 20 supporting the protruding piece 22 moves to the right with respect to the shaft 19, and a gap is created between the protruding piece 22 and the notch 21a, so that the neutral return spring
The cylindrical member 21 rotates in the opposite direction due to the action of
0, the pipes 79 are communicated with the pipes 76, and the tie rod 65 is moved to the left by the rear wheel steering actuator F.
The steering angle of the rear wheels 71 becomes smaller.
こうして、低速では前輪舵角に対する後輪舵角の割合が
大きいが、高速になると自動的に小さくなり、車両の安
全性が確保される。車速が所定値以上では着初制御弁Ｂ
は作動せず、後輪操舵アクチュエータＦは中立位置にあ
り、中立ロック機構Ｈが働き、後輪７１は直進位置に保
持される。In this way, the ratio of the rear wheel steering angle to the front wheel steering angle is large at low speeds, but automatically decreases at high speeds, ensuring vehicle safety. When the vehicle speed exceeds a predetermined value, the arrival control valve B
is not activated, the rear wheel steering actuator F is in the neutral position, the neutral locking mechanism H is activated, and the rear wheels 71 are held in the straight-ahead position.
第５．７図に示すように、接輪操舵アクチュエータＦが
中立位置にある時、逆止弁５３．５４は閉じていて管７
６と７８９との間を′ａ断し、管８０とＷ９１との間を
遮断する。タイロッド６５が右方へ駆動される時、管７
６の油圧は逆止弁５３の弁体１０８に圧力を及ぼし、ば
ね１１２の力に抗して逆止弁５３を押し開く。同時に、
管７６の圧油は管７６ａを経て逆止弁５４の端部からピ
ストン１０４に圧力を及ぼし、弁体１０８をばね１１２
の力に抗して押し開く。この時ばね座１１０はばね５５
の力を受けるばね座９０により、中間壁９８に支持した
ロッド９０ａを介して押えられる。ピストン５６が左方
へ駆動される場合も同様に逆止弁５３，５４が管８０ａ
、８０の油圧により押し開かれる。As shown in Figure 5.7, when the contact wheel steering actuator F is in the neutral position, the check valves 53, 54 are closed and the pipe 7
6 and 789, and the pipe 80 and W91 are cut off. When the tie rod 65 is driven to the right, the tube 7
6 exerts pressure on the valve body 108 of the check valve 53 and pushes the check valve 53 open against the force of the spring 112. at the same time,
The pressure oil in the pipe 76 exerts pressure on the piston 104 from the end of the check valve 54 through the pipe 76a, causing the valve body 108 to be compressed by the spring 112.
Push open against the force of. At this time, the spring seat 110 is the spring 55
It is held down by the spring seat 90 which receives the force of the rod 90a supported on the intermediate wall 98. Similarly, when the piston 56 is driven to the left, the check valves 53 and 54 are connected to the pipe 80a.
, 80 hydraulic pressure.
後輪操舵中に油圧回路の油圧が失陥した（例えば管７６
の亀裂）場合は、ピストン５６ばばね５５の力によりゆ
っくりと中立位置へ戻される。例えばピストン５６が左
方へ戻る時、ばね座８７は端壁９２と逆止弁５３のばね
座１１０から離れているので、ばね１０９の力により弁
体１０８が端壁９２から離れ、室８９と管７６を連通さ
せ、ピストン５６の中立位置への戻りを妨げない。逆止
弁５４は閉じたままであるから、後輪７１に路面からの
外乱入力が加わり、後輪舵角が増大する方向（中立位置
から離れる方向）へタイロッド６５が移動しようとして
も、室９１が閉鎖状態になっているので、タイロッド６
５の移動が阻止され、後輪が勝手に操舵されることはな
く、これにより安全が確保される。Hydraulic pressure in the hydraulic circuit fails while steering the rear wheels (e.g. pipe 76
crack), the piston 56 is slowly returned to the neutral position by the force of the spring 55. For example, when the piston 56 returns to the left, the spring seat 87 is separated from the end wall 92 and the spring seat 110 of the check valve 53, so the force of the spring 109 causes the valve body 108 to separate from the end wall 92, and the chamber 89 The tube 76 is brought into communication and the return of the piston 56 to the neutral position is not obstructed. Since the check valve 54 remains closed, even if disturbance input from the road surface is applied to the rear wheels 71 and the tie rod 65 attempts to move in a direction that increases the rear wheel steering angle (away from the neutral position), the chamber 91 will not close. Since it is in the closed state, tie rod 6
5 is prevented from moving, and the rear wheels are not steered without permission, thereby ensuring safety.
上述の実施例において、中立ロック機構日は後輪操舵ア
クチュエータＦの内部へ配設することができる。また、
舵角特性徐変機構Ａを廃止して軸１９を駆動軸２４に直
接連結すれば、第８図に破線すで示す舵角特性が得られ
る。この場合、中立ロックＩｆｌ＊Ｈと１！磁クラツチ
Ｃは設けないで、ケーブル５０の端部を従動軸６のレバ
ー９ａに連結することが好ましい。In the embodiment described above, the neutral locking mechanism can be arranged inside the rear wheel steering actuator F. Also,
If the steering angle characteristic gradual change mechanism A is abolished and the shaft 19 is directly connected to the drive shaft 24, the steering angle characteristic already shown by the broken line in FIG. 8 can be obtained. In this case, neutral lock Ifl*H and 1! It is preferable to connect the end of the cable 50 to the lever 9a of the driven shaft 6 without providing the magnetic clutch C.
また、後輪操舵アクチュエータＦにおいて、逆出弁５３
．５４がタイロッド６５と平行に配設され、ばね座８７
．９０により作動されるように構成したが、逆止弁５３
．５４をタイロッド６５に対し垂直に配設し、タイロッ
ドに形成したカムにより作動させることができる。In addition, in the rear wheel steering actuator F, the backflow valve 53
．． 54 is arranged parallel to the tie rod 65, and the spring seat 87
．． The check valve 53 is configured to be operated by the check valve 90.
．． 54 is disposed perpendicularly to the tie rod 65 and can be actuated by a cam formed on the tie rod.
上述の差Ｄ ｔｉｌｌ ｍ弁では、駆Ｏ＠と従動軸の回
転位相差を、ねじとスプラインの作用でねし部材の移動
量に変換し、これを通常のスプールに伝達することによ
り油量を静１ｔｌＤｌ、ているが、駆動軸と従動軸の回
転位相差により直接油量を制御する回転スプール型の差
動１ｉ１１ｙＡ弁を用いてもよい。In the above-mentioned differential D till m valve, the rotational phase difference between the driving shaft and the driven shaft is converted into the amount of movement of the screw member by the action of the screw and spline, and this is transmitted to the normal spool to control the oil amount. However, a rotary spool type differential 1i11yA valve that directly controls the oil amount based on the rotational phase difference between the drive shaft and the driven shaft may be used.
［発明の効果］
本発明は上）！のように、油圧源を着初制御弁を経てタ
イロッドを駆動する後輪操舵アクチュエータに接続し、
車速に関連して回転量が変化する駆動軸により差動制ｍ
＋井の弁要素を従動させ、タイロッドにケーブルを介し
て運動連結した従動軸により弁要素を復動させるように
したから、前輪の舵角に応じて差ａυ制御弁の弁要素が
駆動され、後輪操舵アクチュエータへの油圧回路が生じ
、後輪が前輪と反対方向に偏向されるので、低速走行で
の小回り性が向上される。[Effect of the invention] The present invention is above)! Connect the hydraulic power source to the rear wheel steering actuator that drives the tie rod via the first control valve, as shown in the figure below.
Differential braking using a drive shaft whose rotation amount changes in relation to vehicle speed
Since the valve element of the +well is driven and the driven shaft is movably connected to the tie rod via a cable, the valve element of the differential aυ control valve is driven in accordance with the steering angle of the front wheels. A hydraulic circuit is generated to the rear wheel steering actuator, and the rear wheels are deflected in the opposite direction to the front wheels, thereby improving turning ability at low speeds.
後輪のタイロッドの変位はケーブルを通じて弁要素を復
ｅさせる従動軸に回転として伝達され、弁要素が中立位
置へ戻ると、油圧回路がａ！Ｆｉまたは中立状態とされ
、その偏向位置に後輪が保持される。The displacement of the tie rod of the rear wheel is transmitted as rotation through the cable to the driven shaft that returns the valve element, and when the valve element returns to the neutral position, the hydraulic circuit a! Fi or neutral state is established, and the rear wheels are held at that deflection position.
弁要素を復動させるものは、後輪のタイロッドの変位を
伝達するケーブルであるから、構成か定、常に簡単であ
り、また弁要素の動作抵抗は極めて小さいから、ケーブ
ルが伸びるなどの強度上に問題はなく、円滑で安定した
後輪舵角制御が達せられる。What makes the valve element move back is a cable that transmits the displacement of the tie rod of the rear wheel, so the structure is fixed and always simple, and the operating resistance of the valve element is extremely small, so there is no need for strength issues such as stretching of the cable. There are no problems with this, and smooth and stable rear wheel steering angle control can be achieved.
第１図は本発明に係る後輪操舵機構の概略構成図、第２
図はハンドル操作と車速に関連して後輪操舵アクチュエ
ータへの油量を制御する制御部の斜視図、第３図は差動
制御弁の平面断面図、第４図は後輪操舵アクチュエータ
が配設される後輪懸架機構の平面図、第５図は後輪操舵
アクチュエータの平面断面図、第６図は後輪のタイロッ
ドの中立ロック機構を示す平面断面図、第７図は後輪操
舵アクチュエータに備えられる逆止弁の平面断面図、第
８図は後輪操舵機構の舵角特性線図である。
Ａ：舵角特性徐変機構 Ｂ：差動制御弁 Ｃ：電磁クラ
ッチ Ｄニアクチュエータ Ｅ；油量調整弁 Ｆ：後輪
操舵アクチュエータ Ｇ：アクチュエータ Ｈ：中立ロ
ック機構 ９：クラッチ板２つ二円筒部材 ・２２：突
片 ２６：油圧ポンプ３０：前輪舵取機構 ４０：前輪
４１；ハンドル ４５：電流減譚変換器 ５０：ケー
ブル ５１：電源バッテリ ５２：電磁切換弁 ５３，
５４：逆止弁 ５９：ロック部材 ６５：タイロッド
７１：後輪
特許出願人 いすず自動車株式会社FIG. 1 is a schematic configuration diagram of a rear wheel steering mechanism according to the present invention, and FIG.
The figure is a perspective view of the control unit that controls the amount of oil to the rear wheel steering actuator in relation to steering wheel operation and vehicle speed, Figure 3 is a plan cross-sectional view of the differential control valve, and Figure 4 is a diagram showing the arrangement of the rear wheel steering actuator. 5 is a plan view of the rear wheel steering actuator, FIG. 6 is a plan view of the neutral locking mechanism for the rear wheel tie rod, and FIG. 7 is the rear wheel steering actuator. FIG. 8 is a cross-sectional plan view of a check valve provided in the vehicle, and FIG. 8 is a steering angle characteristic diagram of the rear wheel steering mechanism. A: Steering angle characteristic gradual change mechanism B: Differential control valve C: Electromagnetic clutch D near actuator E: Oil amount adjustment valve F: Rear wheel steering actuator G: Actuator H: Neutral lock mechanism 9: Two clutch plates and two cylindrical members・22: Protruding piece 26: Hydraulic pump 30: Front wheel steering mechanism 40: Front wheel 41; Handle 45: Current reduction converter 50: Cable 51: Power battery 52: Solenoid switching valve 53,
54: Check valve 59: Lock member 65: Tie rod
71: Rear wheel patent applicant Isuzu Motors Co., Ltd.
Claims (1)
輪操舵アクチュエータに接続し、ハンドルの切り角に関
連して回転する駆動軸により差動制御弁の弁要素を往動
し、後輪ナックルにケーブルを介して運動連結する従動
軸により弁要素を復動させることを特徴とする後輪操舵
機構。The hydraulic power source is connected to the rear wheel steering actuator that drives the rear wheel knuckles through the differential control valve, and the valve element of the differential control valve is moved forward by the drive shaft that rotates in relation to the turning angle of the steering wheel. A rear wheel steering mechanism characterized in that a valve element is moved back by a driven shaft that is movably connected to a knuckle via a cable.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63216176A JP2778045B2 (en) | 1988-08-30 | 1988-08-30 | Rear wheel steering mechanism |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63216176A JP2778045B2 (en) | 1988-08-30 | 1988-08-30 | Rear wheel steering mechanism |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0263973A true JPH0263973A (en) | 1990-03-05 |
| JP2778045B2 JP2778045B2 (en) | 1998-07-23 |
Family
ID=16684478
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63216176A Expired - Lifetime JP2778045B2 (en) | 1988-08-30 | 1988-08-30 | Rear wheel steering mechanism |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2778045B2 (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61134956A (en) * | 1984-12-06 | 1986-06-23 | Matsushita Electric Ind Co Ltd | Driving device of magnetic tape |
-
1988
- 1988-08-30 JP JP63216176A patent/JP2778045B2/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61134956A (en) * | 1984-12-06 | 1986-06-23 | Matsushita Electric Ind Co Ltd | Driving device of magnetic tape |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2778045B2 (en) | 1998-07-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5147008A (en) | Four-wheel vehicle steering apparatus | |
| US3876030A (en) | Power steering system | |
| JPH07117694A (en) | Power steering device | |
| JPH0263973A (en) | Rear-wheel steering mechanism | |
| US4880073A (en) | Four-wheel steering system of a motor vehicle | |
| JP2712351B2 (en) | Rear wheel steering device | |
| JPH02124381A (en) | Steering angle ratio control device | |
| JPH0285076A (en) | Rear wheel steering controller | |
| JPS62227822A (en) | Change-over controller of central differential gear for vehicle | |
| JP2706786B2 (en) | Four-wheel steering system | |
| JPH0137978Y2 (en) | ||
| JPH022749B2 (en) | ||
| JP2705137B2 (en) | Actuator feedback mechanism | |
| JPS60226369A (en) | Steering-force controller for power steering apparatus | |
| JPH02124377A (en) | Rear wheel steering device of vehicle | |
| JPH0121031B2 (en) | ||
| JPH0263976A (en) | Steering angle ratio controller for four-wheel steered vehicle | |
| JPS6371481A (en) | Power transmission device for vehicle | |
| JP2880303B2 (en) | Differential limiter | |
| JPH0263974A (en) | Rear-wheel steering controller for four-wheel steered vehicle | |
| JPS61207274A (en) | Power steering device for 4-wheel-drive-vehicle | |
| JPS60174364A (en) | Rack/pinion steering system | |
| JP2503540B2 (en) | Hydraulic rear wheel steering mechanism for 4-wheel steering vehicle | |
| JPH0263975A (en) | Rear-wheel steering angle slow variable mechanism | |
| JPH036645Y2 (en) |