JPH02371Y2 - - Google Patents

Description

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

(Prior art) Some four-wheel steering devices for vehicles that steer both front and rear wheels are equipped with a method disclosed in Japanese Patent Laid-Open No. 58-122259 to transmit the displacement of the steering wheel to the rear wheel steering mechanism.
As shown in the publication, there is a vehicle in which this rear wheel steering mechanism is linked to a front wheel steering mechanism linked to a steering handle via a connecting rod extending in the longitudinal direction of the vehicle body.

The above-mentioned connecting rod is generally arranged below the floor panel, but in the event of a vehicle collision, especially when the vehicle is traveling forward with a large impact, the connecting rod may be bent and protrude upward. It is also possible to do this. Therefore, some kind of countermeasure is desired to protect the occupants inside the vehicle in anticipation of such a case.

(Purpose of the invention) This invention was made in consideration of the above-mentioned circumstances, and when a vehicle collides, the connecting rod is bent in an arbitrary direction and deforms protrudingly, especially upward. An object of the present invention is to provide a four-wheel steering device for a vehicle that can reliably prevent the above.

(Structure of the invention) In order to achieve the above-mentioned object, the present invention focuses on the fact that the connecting rod is displaced relative to the vehicle body in the event of a collision, and the force that tends to cause this relative displacement is The connecting rod is replaced by a force that presses the connecting rod downward through a kind of tracing action.

Specifically, a guide part is provided on either the vehicle body side or the connecting rod, and an abutting part is provided on the other side near the guide part, so that when the guide part and the abutting part come into contact with each other, In this case, the connecting rod is pushed downward by the guiding action of the abutting part by the guide part.

(Example) In FIG. 1, A is a front wheel steering mechanism, B is a rear wheel steering mechanism, and the tie rod 1 of the front wheel steering mechanism A is
is connected via a swing arm (lower arm) 2 to a front wheel 3 held on the vehicle body. Also,
A tie rod 1' of a rear wheel steering mechanism B is connected to a rear wheel 5 held on a cross member 4 of the vehicle body via a swing arm 2'.

The front wheel steering mechanism A is of a so-called rack-and-pinion type, in which a rack shaft (not shown) is slidably inserted into a rack housing 6, and a pinion (not shown) disposed in a pinion housing 7. ) are engaged with each other, and a steering handle 9 is connected to the pinion in the pinion housing 7 via a steering shaft 8. As a result, the tie rod 1 is displaced upward or downward in FIG. 1 in response to a rotational operation of the steering handle 9, and the front wheels 3 are steered. Further, the rear wheel steering mechanism B is also of the rack-and-pinion type like the front wheel steering mechanism A, and components corresponding to the front wheel steering mechanism A are indicated by additionally adding a symbol "'". , the duplicate explanation will be omitted.
Note that 10 is a tension rod.

As shown in FIG. 2, the front wheel steering mechanism A and the rear wheel steering mechanism B are linked via a connecting rod 11 extending in the longitudinal direction of the vehicle body. In this embodiment, the connecting rod 11 is divided into two parts, a front rod 12 and a rear rod 13, each of which is elongated.
Both 12 and 13 are connected by a universal joint 14. This connecting rod 11 and front wheel steering mechanism A
In order to connect the front wheel steering mechanism A, a pinion housing 15 is attached to the front wheel steering mechanism A, and an interlocking pinion (not shown) housed in the pinion housing 15 is meshed with the rack shaft in the rack housing 6. . A short output rod 16 integrated with the interlocking pinion extends toward the rear of the vehicle body and is connected to the front end of the front rod 12 via a universal joint 17. Also,
In order to connect the connecting rod 11 and the rear wheel steering mechanism B, a short input rod 18 with an integrated pinion inside the pinion housing 7' extends toward the front of the vehicle body and is connected to the rear end of the front and rear rods 13. and are connected via a universal joint 19. This results in
The rear wheels 5 are connected to a steering wheel 9 via a front wheel steering mechanism A, a connecting rod 11, and a rear wheel steering mechanism B.
It is steered according to the rotation operation.

The connecting rod 11 is disposed below the floor panel 20, as shown in FIG. 2, and the rear end of the front rod 12 is rotatably supported by the floor panel via a bearing 21. Of course, floor panel 2
In addition to the front seat 22, a rear seat 23 is provided on the 0, and in the embodiment, a fuel tank 24 is arranged on the lower surface side of the floor panel 20 so as to be located above the rear rod 13. .

Front and rear rods 12, 1 forming the connecting rod 11
Of the three, the front rod 12 is said to be extremely long,
Since the amount of protruding deformation in the radial direction due to bending during a collision increases, between this front rod 12 and the floor panel 20 on the vehicle body side,
A guide mechanism C consisting of a guide member and an abutment member, which will be described later, is provided. Also, the rear rod 13
It is said to be considerably shorter than the previous Rod 12,
The amount of protruding deformation in the radial direction due to bending during a collision is small, and therefore, a plurality of buffer members 25 made of elastic cylinders are fitted at intervals in the axial direction without providing the guide mechanism C. This prevents damage to the fuel tank 24.

Regarding the guide mechanism C, FIGS. 3 to 5
To explain with reference to the drawings, in this embodiment, an abutment member 26 is provided at approximately the middle of the front rod 12, and a guide member 27 is provided on the lower surface of the floor panel 20 located directly above the abutment member 26. is fixed. This guide member 27 includes a top wall portion 27a,
It has a pair of front and rear walls 27b, 27c and a pair of left and right walls 27d, 27e, and is shaped like a box opening downward, and each inner surface of the front, left and right walls 27b to 27e extends from above to below. The guide surfaces 27b' to 27e' widen toward the guide surface. The abutting member 26 is constructed by, for example, fitting a rectangular cylinder having a larger diameter than the front rod 12 and integrating the rod by welding or the like, and includes an intermediate portion 26a having a hexagonal outer peripheral surface. The intermediate portion 26a is composed of front and rear end portions 26b and 26c, each of which has a hexagonal pyramidal outer circumferential surface that is connected to both ends of the intermediate portion 26a and whose diameter gradually decreases as the distance from the intermediate portion 26a increases.
The abutment member 26 is housed in a space within the guide member 27 at a distance slightly apart from each of the guide surfaces 27b' to 27e' of the guide member 27. Note that the front and rear walls 2 of the guide member 27
7b, 27c have cutout portions 27f, 27g each having a width smaller than the outer diameter of the abutment member 26.
is formed to prevent interference between the guide member 27 and the front rod 12.

Next, the operation of the above configuration will be explained. Now, when a vehicle collides, as soon as the distance between the front wheel steering mechanism A and the rear wheel steering mechanism B becomes smaller, the connecting rod 11 receives a large force in the axial direction, and the abutment member 26 is moved against the guide member 27. On the other hand, it is relatively displaced forward or backward. At this time, the contact member 2
6 is relatively displaced rearward with respect to the guide member 27, it comes into contact with the rear guide surface 27c' of the guide member 27, and due to the guiding action of this guide surface 27c', the contact member 26 and the fifth As shown by arrow X in the figure,
Pressed downward. As a result, the front rod 26 is always bent in such a way that it protrudes downward, and is prevented from protruding upward. Of course,
When the abutment member 26 is relatively displaced forward with respect to the guide member 27, the front rod 1 is moved in the same manner as described above due to the guiding action of the guide surface 27b'.
2 is deformed to protrude downward (see arrow Y in FIG. 5). Further, when the abutment member 26 is displaced relative to the guide member 27 in the left-right direction (vehicle width direction), the front rod 12 is deformed and protrudes downward due to the guiding action of the left and right guide surfaces 27d' and 27e'. be done. In addition, if the abutting member is relatively displaced in the left-right direction, upward protruding deformation is unlikely to occur, so there is no particular problem in terms of passenger protection, but in this case as well, the front rod 12 is forcibly moved downward. If it is made to protrude and deform, the front rod 1 for peripheral equipment can be
This is preferable in terms of preventing unnecessary contact of 2. Furthermore, if the end of the abutment member 26 is made into a tapered surface, such as a pyramidal shape as in the embodiment, the guiding action of the guide member 27 will be further promoted.

FIGS. 6 to 8 show other embodiments of the present invention, and the same components as in the previous embodiments are given the same reference numerals and their explanations will be omitted.

In this embodiment, a pair of guide members 28 are provided for the front rod 12, and a contact member 29 is provided for the floor panel 20. That is, the pair of guide members 28 are arranged with a slight distance from each other in the axial direction, and are configured in the shape of a cone whose diameter increases as they move away from each other. It is configured as a thin plate in the vertical direction. In the case of this embodiment, the outer circumferential surface of the conical guide member 28 serves as a guide surface 28a, and the guiding action of this guide surface allows the front rod to move in the event of a collision, as in the previous embodiment. 12 will be deformed to protrude downward.

In the above embodiment, the case where the connecting rod 11 is composed of two rods 12 and 13 has been explained.
It can also be composed of one rod or three or more rods. Furthermore, the present invention is not limited to the one in which the front wheel steering mechanism A and the rear wheel steering mechanism B are always linked in a fixed steering ratio relationship; for example, the connecting rod 11 and the front wheel steering mechanism A
or between the connecting rod 11 and the rear wheel steering mechanism B
A steering ratio changing mechanism is interposed between the vehicle and the vehicle to change the rear wheel steering angle relative to the front wheel steering angle depending on the vehicle speed (including switching the steering direction of the rear wheels relative to the front wheels).
It is also possible to do so.

(Effects of the invention) As is clear from the above, the invention has the following effects:
Since the connecting rod is reliably prevented from being deformed upward in the event of a vehicle collision, it is possible to provide favorable protection for occupants from the connecting rod.

[Brief explanation of drawings]

Figure 1 is a plan view showing one embodiment of the present invention;
The figure is a simplified side view of Figure 1, Figure 3 is an enlarged side view of the guide mechanism consisting of a guide member and a contact member, viewed from below, and Figure 4 shows the guide mechanism member facing the front side of the vehicle body. Figure 5 is the front view seen from
Figure-line sectional views and Figures 6 to 8 show other embodiments of the present invention, Figure 6 is a simplified side view of the main parts, and Figure 7 is a view of the guide mechanism from the contact member side. The plan view and FIG. 8 are enlarged side views of the guide mechanism. A...Front wheel steering mechanism, B...Rear wheel steering mechanism, C
... Guide mechanism, 3 ... Front wheel, 5 ... Rear wheel, 9 ...
...Steering handle, 11...Connection rod,
12...Front rod, 13...Rear rod, 26,2
9... Contact member, 27, 28... Guide member, 2
7' to 27e', 28a...Guide surface.

Claims (1)

[Scope of Claim for Utility Model Registration] A rear wheel steering mechanism and a front wheel steering mechanism linked to a steering wheel are linked via a connecting rod extending in the longitudinal direction of the vehicle body, and either one of the vehicle body side and the connecting rod A guide portion is provided, and a contact portion is provided on the other side near the guide portion, and the connecting rod is displaced relative to the vehicle body in the front-rear direction so that the guide portion and the contact portion come into contact with each other. A four-wheel steering system for a vehicle, characterized in that when the connecting rod is pressed downward, the connecting rod is pushed downward by the guiding action of the abutting portion by the guide portion.