JPS63275480A - Four-wheel steering device of vehicle - Google Patents

Abstract

PURPOSE:To shorten a stabilizer by coupling the front wheel suspension arms by a stabilizer, in which the tortion part is borne by a dash lower panel, and by arranging below this stabilizer a coupling member to couple the front and rear wheel steering mechanisms. CONSTITUTION:By turning a steering wheel 3, a front wheel steering mechanism 2 steers the left and right front wheels 1 through a pinion 4, rack 5, tie rod 30, and a knuckle arm 31. In response to the steering action of the front wheels 1, a steering shaft 20 of a rear wheel steering mechanism 10 is rotated through another pinion 6 and coupling shafts 15, 18 and thereby the rear wheels 9 are steered with a specified steering ratio. A stabilizer 33 is arranged so as to couple the left and right suspension arms 32, 32, and this is borne by a dash lower arm 7 behind the front wheel axle. Here the coupling shaft 18 is situated below the stabilizer 33, that provides enhanced installing easiness and service characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a four-wheel steering device in a vehicle such as an automobile that controls the steering of the rear wheels in accordance with the steering of the front wheels. The present invention relates to a rear wheel suspension mechanism related to a wheel steering device.

(Prior art) In the past, steering devices for four-wheeled vehicles such as automobiles were designed to steer only the front wheels, but recently, from the perspective of improving vehicle retrospective performance and running stability, steering devices for four-wheeled vehicles such as automobiles have been designed to steer not only the front wheels. A four-wheel steering device that also steers the rear wheels has been proposed. A vehicle equipped with such a four-wheel steering device has a front wheel steering mechanism that steers the front wheels, and a rear wheel steering mechanism that steers the rear wheels, as disclosed in Japanese Patent Publication No. 62-9076, for example. The steering mechanism for the front and rear wheels is mechanically connected by a connecting shaft extending in the longitudinal direction, and the front wheel steering torque is transmitted from the front wheel steering mechanism to the rear wheel steering mechanism, thereby controlling the steering of the front wheels. The rear wheels are configured to be steered accordingly.

By the way, in order to increase the roll rigidity of the vehicle body, general automobiles are provided with a stabilizer that connects the suspension arms of the front wheels and has a torsion portion pivoted to the vehicle body, but this stabilizer is also disclosed in the above-mentioned publication. As shown in the figure, the torsion portion is usually supported by the vehicle body in front of the front wheel axle. however,
Because the engine, radiator, etc. are installed in front of the front wheel axle, it is difficult to layout the stabilizer.Moreover, if the stabilizer is placed in front of the front wheel axle, it must be long to avoid interference with the engine, radiator, etc. Therefore, in order to obtain a predetermined spring constant, each stabilizer must be thick and heavy. Furthermore, in vehicles equipped with a four-wheel steering system, when the stabilizer is placed behind the front wheel axle, it may interfere with the connecting member that transmits torque from the front wheel steering mechanism to the rear wheel steering mechanism, resulting in poor assembly and serviceability. This results in problems that worsen sexuality.

(Object of the Invention) Therefore, an object of the present invention is to provide a four-wheel steering device for a vehicle that solves the above-mentioned problems that occur when the stabilizer is arranged behind the front wheel axle.

(Structure of the Invention) In order to achieve the above object, in the present invention, the torsion part of the stabilizer that connects the suspension arms of the front wheels is attached to the darts lower panel behind the front wheel axle, and the front wheel steering mechanism and the rear wheel steering The present invention is characterized in that a connecting member for connecting the stabilizer to the mechanism is disposed below the stabilizer.

(Effects of the Invention) According to the present invention, by arranging the stabilizer around the rear side of the front wheel axle, the overall length of the stabilizer can be made shorter than when the stabilizer is placed around the front side of the front wheel axle. This has the advantage of allowing the use of a smaller diameter and lighter stabilizer.

In addition, on the vehicle assembly line for front-wheel drive vehicles, the subassembly that integrates the engine and front wheel suspension device is placed on a lifting table, lifted up, and installed from the bottom of the vehicle body transported by an overhead conveyor. However, 1. When the stabilizer is placed above the connecting member as in the present invention, the engine/suspension subassembly including the stabilizer is first attached to the vehicle body, and toe adjustment and other suspension geometry adjustments are made. Since it becomes possible to attach the four-wheel steering device to the vehicle body after the completion of the four-wheel steering device, it is possible to improve the ease of assembly in a vehicle equipped with the four-wheel steering device. Furthermore, even when the connecting member is removed from the vehicle body during servicing, since the stabilizer is located above the connecting member, it is not necessary to remove the stabilizer, which improves serviceability.

(Embodiments) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view schematically showing an embodiment of a four-wheel steering system for a vehicle according to the present invention, and FIG. 2 is a side view thereof.

A front wheel steering mechanism 2 that steers left and right front wheels l includes a rack member 5 that converts the rotational motion of a pinion 4 rotated by a steering wheel 3 into a linear reciprocating motion, and a rack member 5 that converts the linear reciprocating motion into a rotary motion. It is equipped with a pinion 6. The rack member 5 is provided in front of the darts lower panel 7 and at the rear of the engine E, and is supported by the darts lower panel 7 via a bracket 8. In the front wheel steering mechanism 2, a tie rod 30 is connected to both ends of the rack member 5, and the tie rod 30 is connected to a knuckle arm 31. 32 is an A-type suspension arm (lower arm).

With this configuration, the rack member 5 moves in the vehicle width direction by operating the steering wheel 3, and this movement is transmitted to the knuckle arm 31 via the tie rod 30, so that the front wheel 1 is steered. In addition, stabilizers 33 are installed on both suspension arms 3 to increase the roll rigidity of the vehicle body.
The torsion portion 33a in the middle is supported by the ζ dart lower arm 7 at the rear of the axle of the front wheel 1 (its axis is shown by a dashed line). There is.

On the other hand, a rear wheel steering mechanism 10 that steers the left and right rear wheels 9 is supported by a rear cross member 11 extending in the width direction of the vehicle, and a power steering mechanism 12 is attached.

The front wheel steering mechanism 2 and the rear wheel steering mechanism 10 include a plurality of mutually connected shafts 15 and 16 that extend in the longitudinal direction of the vehicle body and are disposed within the tunnel portion 14a of the floor member 14 that constitutes the floor of the vehicle interior. .17 and 18. That is, as is clear from FIG. 3, the connecting shaft 18 that projects rearward from the pinion 6 of the front wheel steering mechanism 2 passes below the stabilizer 33 and is connected to the front end of the shaft 15 via the universal joint 19. The rear end of the shaft 17 is connected to the steering shaft 20 of the rear wheel steering mechanism 10 by a universal joint 21, and the rear end of the shaft 15 and the front end of the shaft 17 are connected to the front end of the shaft 16 and the rear end of the shaft 17. The ends are connected by universal joints 22 and 23, respectively. The amount of steering of the front wheels 1 by the front wheel steering mechanism 2 is controlled by the plurality of shafts 18, 15, 16 and 17.
The rear wheels 9 are steered at a predetermined steering ratio. Note that the front and rear ends of the shaft 16 are supported on the floor panel 14 by hair rings 28 and 29, respectively.

The rear wheel suspension mechanism consists of a strut type.
It is equipped with an I-type suspension arm (lower arm) 35 and a trailing link 36, and as shown in detail in FIG. 2, the inner end of this summer-type suspension arm 35 is
It is connected to the cross member 11 so as to be swingable in the vertical direction, extends in the vehicle width direction, and supports the rear wheel 9 at its outer end. 3
Reference numeral 7 denotes a tie rod for steering the rear wheels 9. The inner end of this tie loft 37 is connected to the rear wheel steering mechanism 10, and the outer end of the tie rod 37 is connected to a knuckle arm 38. The front end of the trailing link 36 is connected to the outer end of the vehicle body avoiding the fuel tank 24 so as to be able to swing vertically, and the rear end of the trailing link 36 is connected to the vicinity of the outer end of the I-type suspension arm 35. has been done.

The above is the configuration of the embodiment of the four-wheel steering system for a vehicle according to the present invention.As is clear from the above description, since the connecting shaft 18 is disposed below the stabilizer 33, the four-wheel steering system can be operated. It is possible to improve the ease of assembly and serviceability of a vehicle equipped with the present invention.

[Brief explanation of the drawing]

FIG. 1 is a plan view schematically showing an embodiment of a four-wheel steering system for a vehicle according to the present invention, FIG. 2 is a side view thereof, and FIG. 3 is a longitudinal front view for explaining the characteristic parts of the present invention. It is. 2.-Front wheel steering mechanism 3.-Steering wheel 7..Datsush lower panel 10.-Rear wheel steering mechanism 18 Connection shaft 32..Suspension arm 33.-Stabilizer

Claims (1)

[Scope of Claims] A front wheel steering mechanism that steers a front wheel, a rear wheel steering mechanism that steers a rear wheel, and a connecting member that connects the front wheel steering mechanism and the rear wheel steering mechanism. The four-wheel steering system for a vehicle includes a stabilizer that connects front wheel suspension arms and whose torsion portion is supported by a dash lower panel behind the front wheel axle, and the connecting member is disposed below the stabilizer. A four-wheel steering device for a vehicle, characterized in that: