JPH0825480B2 - 4-wheel steering system for vehicles - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a four-wheel steering system for a vehicle, such as an automobile, in which the rear wheels are also steered according to the steering of the front wheels. is there.

(Prior Art) Conventionally, as a four-wheel steering system for a vehicle of this type, as disclosed in, for example, Japanese Patent Laid-Open No. 58-122259, a front wheel steering mechanism for steering wheels and a rear wheel are used. A front wheel steering mechanism for steering is provided, and the front and rear wheel steering mechanisms are mechanically connected by a shaft extending in the front-rear direction to transmit the steering amount of the front wheels to the rear wheel steering mechanism. It is known that the rear wheels are steered with a predetermined steering ratio in accordance with the above.

In the four-wheel steering system as described above, the shaft that connects the front wheel steering mechanism and the rear wheel steering mechanism is, for example, an actual open shaft.
As disclosed in No. 61-80169, it is arranged near the lower part of the passenger compartment floor and is supported slidably in the axial direction of the shaft by a supporting member fixed to the vehicle body. Further, in mounting the four-wheel steering device on the vehicle body, after mounting the front wheel steering mechanism and the rear wheel steering mechanism on the vehicle body, the support member for supporting the shaft is fixed to the vehicle body, and the front and rear wheel rolling of both ends of the shaft are performed. The connection to the rudder mechanism will be performed.

(Problems to be Solved by the Invention) Although there is no particular problem after being mounted on the vehicle body in this way, before the completion of mounting, the support member freely slides in the axial direction with respect to the shaft. Therefore, a protrusion such as a joint portion at the end of the shaft comes into contact with a seal member that is provided at the end of the support member and seals the lubricant enclosed in the support member. Careful handling of the shaft and support members is required to avoid damage.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a four-wheel steering system for a vehicle that can facilitate handling of the shaft before completion of mounting on the vehicle body.

(Means for Solving the Problems) In the four-wheel steering system for a vehicle according to the present invention, when the shaft is provided with the contact preventing member and the supporting member supporting the shaft is provided with the locking member, the shaft slides. By making the contact prevention member engage with the locking member at a sliding distance shorter than the sliding distance required for the protrusion provided on the shaft to contact the seal member provided on the support member. The purpose of the present invention is to prevent the seal member from being damaged and to achieve the above object. That is, a front wheel steering mechanism that steers the front wheels according to steering of the steering wheel, a rear wheel steering mechanism that steers the rear wheels according to steering of the front wheels by the front wheel steering mechanism, the front wheel steering mechanism, and the A shaft that is connected to a rear wheel steering mechanism and that transmits the amount of steering of the front wheels by the front wheel steering mechanism to the rear wheel steering mechanism and a shaft that is fixed to the vehicle body so that the shaft can slide in the axial direction of the shaft. A support member, which is provided with a seal member at its axial end, a locking member fixed to the support member, and the shaft, which is provided in the axial direction of the shaft. A contact preventing member that engages with the locking member when sliding and prevents the protrusion provided on the shaft from contacting the seal member of the support member. Is.

The above-mentioned "projection portion" means a portion protruding from the peripheral surface portion of the shaft, and a joint portion formed at the end portion of the shaft or a dust boot covering the joint portion, and a seal member formed by sliding between the shaft and a supporting member. It may be provided integrally with the shaft or separately provided, including all that may come into contact with the shaft.

The "locking member" may be provided by fixing another member to the support member by welding or the like, or may be formed integrally with the support member. Also, the "locking member" has a specific shape,
The material and the like are not limited, and these should be appropriately selected so as to exert an engaging action with the contact prevention member.

The above "contact prevention member" is
If the protrusion provided on the shaft engages with the locking member at a sliding distance shorter than the sliding distance required to contact the seal member provided on the support member, its mounting position and shape The material and the like are not particularly limited. That is, the contact prevention member may be provided on the shaft portion on the side where the protrusion is provided with respect to the support member, or may be provided on the opposite side. When provided between the protrusion and the support member on the protrusion side, the contact prevention member may be fixed to the shaft or may be slidably fitted thereto. Also, since the contact prevention member is interposed between the protrusion and the seal member, it is possible to prevent the protrusion from contacting the seal member. In this case, it is also possible to act as a locking member on a portion of the support member other than the member provided with the seal member, without newly providing a locking member to be engaged with the contact prevention member. It is possible.
On the other hand, when the contact prevention member is provided on the side opposite to the protrusion,
Or if it is provided behind the protrusion on the protrusion side,
Since the contact prevention member does not exist between the protrusion and the seal member, it is necessary to fix this to the shaft.
When there is a structural restriction such as when there is no space for providing the contact prevention member between the support member and the protrusion, it is effective to provide it at the above position.

The “shaft” may be composed of one piece, or may be formed by connecting a plurality of pieces to each other. In any of these cases, the number of supporting members may be one. A plurality of them may be provided, or in other words, it suffices that the engagement of the locking member and the contact prevention member prevents the seal member provided on each of the support members from contacting the projection of the shaft. .

(Operation) With the above configuration, it is possible to prevent the protrusion provided on the shaft from coming into contact with the seal member provided on the support member even if the shaft and the support member supporting the shaft slide. There is no risk of damaging the seal member even in a situation where the shaft and the support member can freely slide, such as before mounting the shaft on the vehicle body or during mounting work.

(Effect of the invention) Therefore, according to the present invention, it is not necessary to pay special attention to the handling of the shaft before the completion of mounting on the vehicle body, and the assembling workability can be improved.

(Examples) Examples of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a plan view 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, in which the left side is the front part of the vehicle and the right side is the rear part. The front wheel steering mechanism 2 that steers the left and right front wheels 1 includes a rack member 4 that converts the rotational movement of the steering handle 3 into a linear reciprocating movement, and a pinion 5 that converts the linear reciprocating movement into a rotational movement. There is.
The rack member 4 is provided in front of the dash lower panel 6 and behind the engine 7, and is supported by the dash lower panel 6 via a bracket 8. On the other hand, a rear wheel steering mechanism 10 that steers the left and right rear wheels 9 includes a rack and pinion mechanism 13 supported by a rear cross member 11 and provided with a power steering mechanism 12.

The front wheel steering mechanism 2 and the rear wheel steering mechanism 10 are provided with a plurality of mutually connected shafts 15 and 16 extending in the vehicle front-rear direction, which are disposed in the tunnel portion 14a of the floor member 14 that constitutes the floor of the passenger compartment. And 17 are linked together. That is, the front end of the shaft 15 is connected to the drive shaft 18 that is provided coaxially with the pinion 5 of the front wheel steering mechanism 2 and rotates with the rotation of the pinion 5 by the universal joint 19, and the rear end of the shaft 17 is A universal joint 21 connects the steering shaft 20 of the rack and pinion mechanism 13 of the end steering mechanism 10 with a rear end of the shaft 15 and the shaft 17.
The front ends of the shafts are connected to the front and rear ends of the shaft 16 by universal joints 22 and 23, respectively.
By the plurality of shafts 15, 16 and 17, the steering amount of the front wheel 1 by the front wheel steering mechanism 2 is transmitted to the rear wheel steering mechanism 10,
The rear wheels 9 are steered at a predetermined steering ratio. In addition,
Front and rear wheel steering mechanism 2,1 with multiple shafts 15, 16 and 17
The configuration in which 0s are connected is to avoid undulations of the floor member 14, the fuel tank 24, and the like, and increase the degree of freedom in layout.

The shaft 16 located between the shafts 15 and 17 is
In order to maintain the illustrated position, it is supported by the vehicle body near its front end and rear end. Ie shaft 16
Near the front end of the tunnel member 14 of the floor member 14.
A shaft is slidably supported in the axial direction of the shaft 16 by a bearing 28 welded to a bracket 27 fixed to a U-shaped member 25 (see FIG. 3) welded to the side surface of a by a bolt 26, On the other hand, in the vicinity of the rear end, a bearing welded to a bracket 31 fixed by a bolt 30 to a U-shaped member 29 welded to the upper surface of the tunnel portion 14a of the floor member 14.
It is rotatably supported by 32 so as to be slidable in the axial direction of the shaft 16.

As shown in FIG. 2, the bracket 27 is fastened by the bolts 26 at two locations, and the bolts 26 are fastened through the groove portions 27a that are open to the front. On the other hand, the fastening of the bracket 31 with the bolt 30 is performed by passing the bolt 30 through the round hole formed in the bracket 31.

Both the bearings 28 and 32 have the structure shown in FIG. That is, a plurality of bearing needles 33 arranged on the circumference of the shaft 16, bearing holders 34 supporting these, and oil seals provided on both sides of the bearing holder 34 to seal the lubricant enclosed in the bearings. 35 and an outer ring 36 that accommodates these.

As shown in FIGS. 1 and 2, disk-shaped stopper members 37 and 38 having substantially the same diameter as the outer diameters of the bearings 28 and 32 are provided in front of the respective portions of the shaft 16 supported by the bearings 28 and 32. Each is fixed by welding. These stopper members 37, 38 are provided in order to improve safety in the event of a collision. That is, when the shaft 16 slides rearward in the axial direction due to the abutting action of the engine 7 and the front wheel steering mechanism 2 at the time of a vehicle collision, the stopper members 37 and 38 are moved to the outer rings 36 of the bearings 28 and 32, respectively. The sliding movement of the shaft 16 is regulated to a predetermined amount or less by contacting the shaft 16, and when the shaft 16 slides a predetermined distance, a forward reaction force is applied to the shaft 16 to move the front wheel steering mechanism 2 backward. Also, the rearward movement of the dash lower panel 6 that supports this is regulated to protect the occupant.

The shaft 17 is provided with an axial stroke absorbing mechanism 39. This axial stroke absorbing mechanism 39 has a fifth
As shown in the figure, the shaft 17 is divided into two parts, the front end part of the shaft front part 17a is formed into a tubular shape, and the front end part of the shaft rear part 17b is slidably inserted therein, and the both ends are cut pins. 40
When the load more than a predetermined value is applied to the shaft 17 in the axial direction, the cutting pin 40 is cut to contract the shaft 17, thereby absorbing the stroke.

As shown in FIG. 2, the front end of the bracket 31 welded to the bearing 32 has a locking portion 31a bent downward.
Further, the joint portion 23 located at the rear of the bearing 32 is provided with a bellows-shaped rubber dust boot 41 that covers the joint portion 23 and serves as a protrusion of the shaft 16. There is. Although not shown, the other joint parts 19, 21 and 22 are also provided with dust boots similar to the dust boot 41.

FIG. 6 is an enlarged view of part VI of FIG.
It is a figure which shows 32 vicinity in detail.

The locking portion 31a of the bracket 31 is formed so as to be positioned a predetermined distance ahead of the stopper member 38 fixed to the shaft 16 when the shaft 16 is mounted on the vehicle body. That is, the gap A between the stopper member 38 and the locking portion 31a is formed to be narrower than the gap B between the oil seal 35 of the bearing 32 and the front end portion 41a of the dust boot 41.

 Next, the operation of this embodiment will be described.

The work for mounting the four-wheel steering system on the vehicle body is as shown in FIG. 2 after mounting the front wheel steering mechanism 2 and the rear wheel steering mechanism 10 and then connecting the shafts 15, 16, 1 connected by the joints 22, 23.
It is a procedure to mount 7, and these shafts 15,1
Bearings 6 that support the shaft 16
8 and 32 are fixed to the vehicle body by bolting brackets 27 and 31 fixed to them, and then the shaft 15 is connected to the drive shaft 18 of the front wheel steering mechanism 2 and the shaft 17
And the steering shaft 20 of the rear wheel steering mechanism 10 are connected.

Therefore, after the shafts 15, 16 and 17 are mounted on the vehicle body as shown in the figure, the shaft 16 and the bearings 28 and 32 do not slide except in special cases such as a vehicle collision. In, you can slide freely. Therefore, in FIG.
When 16 slides forward, the front end portion 41a of the dust boot 41 may come into contact with and damage the oil seal 35 of the bearing 32, but according to the present embodiment, the front end portion of the dust boot 41 is damaged. The stopper member 38 has a sliding distance shorter than the sliding distance required for 41a to contact the oil seal 35.
Since the lock portion 31a of the bracket 31 is engaged with the lock portion 31, the oil seal 35 is not likely to be damaged. When the shaft 16 slides rearward with respect to the bearing 32, the stopper member 38 contacts the bearing 32, but since it contacts the outer ring 36 of the bearing 32, the oil seal 35 is not damaged. Absent. Also,
As for the bearing 28, as shown in FIG. 2, when the shaft 16 slides backward, the stopper member 37 and the outer ring 36 of the bearing 28 come into contact with each other, while the shaft 28
When 16 slides forward, there is no member in the vicinity of the bearing 28 that abuts on it, but even if the sliding amount is large, the locking portion 31a of the bracket 31 and the outer linder 36 of the bearing 28 abut. Therefore, there is no possibility that the oil seal 35 will be damaged.

As described above, in this embodiment, the oil seal 35 is prevented from being damaged by the engaging action of the contact prevention member fixed to the shaft 16 and the locking member fixed to the bearings 28 and 32. However, the stopper member 37 functions as the contact preventing member and the locking member with respect to the sliding of the bearing 28 and the shaft 16.
And the outer ring 36 of the bearing 28, and with respect to the sliding of the bearing 32 and the shaft 16, the bracket 31 is provided with a stopper member 38 and a locking portion 31a, respectively.

As described in detail above, according to this embodiment, the bearing
Even if 28 and 32 slide on the shaft 16, the oil seal 35 is not damaged, so the shafts 15, 16, 17 and the bearings 28, 32 that slide with the shaft 15 before the completion of mounting on the vehicle body It becomes extremely easy to handle the intermediate process product.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of a four-wheel steering system for a vehicle according to the present invention, FIG. 2 is a side view of the system, FIG. 3 is a sectional view taken along the line III-III of FIG. 2, and FIG. FIG. 5 is a side sectional view showing the structure of FIG. 5 in detail, FIG. 5 is a side sectional view showing the stroke absorbing mechanism in detail, and FIG. 6 is an enlarged detailed view of a VI portion of FIG. 1 …… Front wheel, 2 …… Front wheel steering mechanism 9 …… Rear wheel, 10 …… Rear wheel steering mechanism 15,16,17 …… Shaft 28 …… Bearing (supporting member, locking member) 31 …… Bracket ( Locking member 32 32 Bearing (supporting member) 35 Sealing member 37, 38 Stopper member (contact prevention member) 41 Dust boot (projection)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuhiro Nakajima 3-1, Shinchi Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Co., Ltd. (56) References: 61-80169 (JP, U) 1475 (JP, U)

Claims (1)

[Claims] 1. A front wheel steering mechanism for steering front wheels according to steering of a steering wheel, a rear wheel steering mechanism for steering rear wheels according to steering of front wheels by the front wheel steering mechanism, and the front wheel steering mechanism. A shaft that is connected to a mechanism and the rear wheel steering mechanism and that transmits the amount of steering of the front wheels by the front wheel steering mechanism to the rear wheel steering mechanism; and a shaft that is fixed to the vehicle body and slides the shaft in the axial direction of the shaft. A support member, which is movably supported, is provided with a seal member at the end in the axial direction, a locking member fixedly provided on the support member, and the shaft, the shaft being provided on the shaft. And a contact prevention member that engages with the locking member when sliding in the axial direction and prevents the protrusion provided on the shaft from contacting the seal member of the support member. A four-wheel steering system for a vehicle.