JPH0244617Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a four-wheel steering device for a vehicle.

(Prior Art) Conventionally, a four-wheel steering system for a vehicle includes a steering device that steers the front wheels, a steering amount from the steering device through the rotational movement around the axis of a rod member, and a steering device that steers the front wheels. A vehicle equipped with a rear wheel steering mechanism that steers the rear wheels in response to steering is generally well known (for example, see Japanese Patent Application Laid-Open No. 112875/1983).

(Problem to be solved by the invention) However, in a vehicle equipped with the above-mentioned four-wheel steering system, when trying to adjust the front wheel alignment during mass production or service, for example, it is difficult to adjust the front wheel alignment through the above-mentioned rod member. There was a problem in that the steering force generated when adjusting the front wheel alignment was input to the rear wheel steering mechanism, causing the rear wheel alignment to shift. Conversely, when attempting to adjust the rear wheel alignment, there is a problem in that the front wheel alignment becomes misaligned, and there has been an urgent need for some kind of solution.

In view of these points, the purpose of the present invention is to provide a device that enables independent adjustment of front wheel alignment and rear wheel alignment in the above-mentioned four-wheel steering system during mass production or service. We aim to provide the following.

(Means for Solving the Problems) In order to achieve the above object, the solving means of the present invention includes a steering device that steers the front wheels, and a rotational movement around the axis of a rod member that converts the amount of steering from the steering device into and a rear wheel steering mechanism that steers the rear wheels according to the steering of the front wheels.
In the wheel steering device, the rod member is divided into front and rear parts, and the divided rods each have a fastening member that tightens the connected state, and by tightening the fastening member, relative rotation around the axis between the two rods is prevented. The two rods are connected by a joint that allows relative rotation about the axis between the two rods while maintaining the connected state by loosening the fastening member.

(Function) With the above configuration, in the present invention, when adjusting front or rear wheel alignment during mass production or service, the fastening member is loosened in advance at the joint to maintain the connected state of both split rods. By allowing relative rotation about the axis between the two split rods, the alignment of one wheel can be adjusted independently without affecting the alignment of the other wheel.

On the other hand, after adjusting the wheel alignment, tightening the fastening member prevents relative rotation between the split rods around the axis, so the rod members can be fixed without being affected by the splitting of the rod members. It is possible to reliably perform the function of transmitting the steering amount from the steering device to the rear wheel steering mechanism through rotational motion.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

1 and 2 show the overall configuration of a four-wheel steering system for a vehicle according to the present invention, in which reference numeral 1 denotes a steering system for steering left and right front wheels 2; 3, and a rack and pinion mechanism 4 at the tip of the steering wheel 3.
A tie rod connecting rod 5 is connected through the steering wheel 3 and reciprocates in the vehicle width direction by the steering force of the steering wheel 3.
and a pair of left and right tie rods 6, 6 whose base ends are each connected to the end of the tie rod connecting rod 5, and which transmit the reciprocating motion of the tie rod connecting rod 5 to the front wheel 2 to steer the front wheel 2 left and right. There is.

A rear wheel steering mechanism 7 steers left and right rear wheels 8, and the front end of the rear wheel steering mechanism 7 is connected to the tie rod connecting rod 5 of the steering device 1 via a rack and pinion mechanism 9. A rod member 10 serves as a steering input shaft, and a tie rod connecting rod (not shown) is connected to the rear end of the rod member 10 via a rack and pinion mechanism 11 and reciprocates in the vehicle width direction by the rotational force of the rod member 10. ), and a pair of left and right tie rods 12, 12 whose base ends are respectively connected to the ends of the tie rod connecting rods and which transmit the reciprocating motion of the tie rod connecting rods to the rear wheels 8. (The reciprocating motion of the tie rod connecting rod 5) is received through the rotational motion of the rod member 10 about the axis, and the rear wheels 8 are steered left and right in response to the steering of the front wheels 2.

The rear wheel steering mechanism 7 also includes a hydraulic actuator 1 whose tie rod connecting rod is an operating rod.
It has 3. The hydraulic actuator 13 is
Although not shown, it has a left-turning hydraulic chamber and a right-turning hydraulic chamber inside, and pressure oil is supplied to both hydraulic chambers through a control valve 14 that is switched depending on the rotation direction of the rod member 10. The tie rod connecting rod is moved in the vehicle width direction by rotation of the rod member 10.

On the other hand, the rod member 10 is attached to the vehicle body floor portion 1.
5 are arranged in the longitudinal direction of the vehicle body along the lower surface, and are divided into four parts in the middle, and are divided into first, second, third and fourth divided rods 16a to 16 from the front side.
It has 6d. The first divided rod 16a and the second divided rod 16 and the second divided rod 1
6b and the third divided rod 16c are connected to each other by universal joints 17a and 17b, respectively, and the third divided rod 16c and the fourth divided rod 16d are connected to each other by a flange joint 18.

As shown in detail in FIGS. 3 and 4, the flange joint 18 has a first flange 20 having a pair of arc-shaped elongated holes 19, 19 centered on the axis.
and a second flange 23 having two threaded holes 22, 22 into which bolts 21, 21 as fastening members are screwed and fastened through each elongated hole 19 of the first flange 20. By loosening the first flange 20, the flanges 20 and 23 can rotate relative to each other around the axis within the length range of the elongated hole 19 of the first flange 20. The second flange 23 is connected at its axial center to the front end of the fourth split rod 16d. On the other hand, a cylindrical boss portion 24 is integrally formed at the axial center of the first flange 20, a spline surface 25 is formed on the inner peripheral surface of the boss portion 24, and a spline surface 25 is formed on the inner peripheral surface of the boss portion 24. A spline surface 26 corresponding to the spline surface 25 is formed on the outer peripheral surface of the rear end.
5 and 26, the first flange 20 is spline connected to the rear end of the third split rod 16c. In FIG. 3, 27 is a bellows member provided to cover the spline joint between the first flange 20 and the third split rod 16c.

Therefore, in the above embodiment, when adjusting the wheel alignment during mass production, the bolts 21, 21 of the flange joint 18 are loosened in advance, so that the front wheel alignment (the steering device 1) is adjusted. The steering adjustment of the front wheels 2) and the rear wheel alignment (the steering adjustment of the rear wheels 8 using the rear wheel steering mechanism 7) can be adjusted independently, and the above-mentioned flange joint 18 can be adjusted independently after adjusting the wheel alignment. bolt 2
Steering device 1 just by tightening 1 and 21
Phase matching can be easily performed between the rear wheel steering mechanism 7 and the rear wheel steering mechanism 7.

Further, when the phase alignment between the steering device 1 and the rear wheel steering mechanism 7 is fixed by tightening the bolts 21, the split rod 16 is fixed at the flange joint 18.
Since the relative rotation around the axis between the wheels c and 16d is reliably prevented, no phase shift occurs between the steering device 1 and the rear wheel steering mechanism 7 after adjustment.

Furthermore, the length of the rod members 10 may vary during mass production assembly, and the length between the rod members 10 (that is, the tie rod connecting rod 5 of the steering device 1 and the tie rod connecting rod of the rear wheel steering mechanism 7) may vary due to deformation of the vehicle body while driving. When the length between the rod member 13 and the hydraulic actuator 13 changes, the length of the rod member 10 expands and contracts at the spline joint between the flange joint 18 and the third divided rod 16c of the rod member 10, and the length of the rod member 10 changes. Variations in the rod members 10 and changes in the length between the rod members 10 can be absorbed in the axial direction.

Moreover, the mechanism that exhibits the above-mentioned axial relief function is provided at the same location as the flange joint 18 as a phasing mechanism, and the first flange 20 of the flange joint 18 is one component of the spline connection. Therefore, both of the above mechanisms can be compactly integrated. Therefore, the degree of freedom in terms of layout can be increased in securing both the phase combination function and the axial relief function, and the optimal layout can effectively exhibit both the functions.

Note that the present invention is not limited to the above-mentioned embodiments, but includes various other modifications. For example, in the above embodiment, the rod member 10 is divided into four parts, and the third divided rod 16c from the front side and the fourth divided rod 16d are connected by the flange joint 18. , by loosening the fastening member connecting the other split rods that are adjacent to each other, relative rotation around the axis between the two rods is allowed while the connected state of both rods is maintained. They may be connected by a joint. Further, it goes without saying that the number of divisions of the rod member 10 is not limited to four as in the above embodiment.

(Effects of the invention) As described above, according to the four-wheel steering system for a vehicle according to the present invention, the divided rods of the rod member are connected to each other by a joint having a fastening member so that the position of the rod member can be adjusted around the axis. The front and rear wheel alignments can be performed independently without impairing the function of transmitting the steering amount from the steering device to the rear wheel steering mechanism through the rotational movement of the steering wheel. In addition, since it has a simple structure in which the rod member is divided and a mechanism that allows position adjustment around the axis is incorporated into the joint that connects the two, there is no increase in costs, and the above mechanism can be incorporated into the rod member. Therefore, there is a high degree of freedom in the installation position, and if it is installed in a position where a working space is secured, work efficiency can be improved, and excellent practical effects can be achieved.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a plan view showing the overall configuration of a four-wheel steering system for a vehicle, Fig. 2 is a side view of the same, and Fig. 3 is a longitudinal side view showing the main parts. FIG. 4 is a sectional view taken along the - line in FIG. 3. 1...Steering device, 2...Front wheel, 7...
Rear wheel steering mechanism, 8... Rear wheel, 10... Rod member, 16a to 16d... Split rod, 18... Flange joint, 20... First flange, 21... Bolt (fastening member).

Claims (1)

[Scope of utility model registration request] A steering device that steers a front wheel, and a rear wheel steering mechanism that receives a steering amount from the steering device through a rotational movement about an axis of a rod member and steers a rear wheel in accordance with the steering of the front wheel. In a four-wheel steering system for a vehicle equipped with a four-wheel steering system, the rod member is divided into front and rear parts, and the divided rods each have a fastening member that tightens the connected state, and by tightening the fastening member, the connection between the two rods is Connected by a joint that prevents relative rotation around the axis and allows relative rotation around the axis between both rods while maintaining the connected state of both rods by loosening the fastening member. A four-wheel steering device for a vehicle characterized by: