JPH0449026Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to a four-wheel steering system for vehicles such as automobiles, which controls the steering of the rear wheels in response to the steering of the front wheels. be.

(Prior Art) Conventionally, as a four-wheel steering system for this type of vehicle, a front wheel steering mechanism for steering the front wheels and a front wheel steering mechanism for steering the rear wheels have been used, for example, as disclosed in Japanese Patent Application Laid-open No. 58-122259. The front and rear wheel steering mechanisms are mechanically connected by a shaft extending in the longitudinal direction to transmit the amount of front wheel steering to the rear wheel steering mechanism, thereby steering the front wheels. It is known that the rear wheels are steered at a predetermined steering ratio depending on the situation.

In the above-mentioned four-wheel steering system, the shaft is arranged near the lower part of the vehicle interior floor and is supported by a support member attached to the vehicle body, as disclosed in, for example, Japanese Utility Model Application Publication No. 61-80169. It is gaining support. This support member prevents situations such as when the shaft receives an impact load from the front or rear, such as in the case of a head-on collision, where the shaft bends due to the reaction force of the support member and deforms the cabin floor. It is desirable to have a configuration that allows avoidance. As a countermeasure to this problem, it is conceivable to form an engagement groove in the support member that extends in the axial direction of the shaft. That is, a projecting member such as a bolt provided on the vehicle body is fitted into the engagement groove, thereby allowing the support member to move relative to the vehicle body together with the shaft.

(Problems to be solved by the invention) However, forming the above-mentioned engagement grooves in the support member also causes a decrease in work efficiency when mounting the four-wheel steering device on the vehicle body. You could think so. In other words, when mounting a four-wheel steering device on a vehicle body, the front wheel steering mechanism and the rear wheel steering mechanism are mounted on the vehicle body, while a support member that supports the shaft is attached to the vehicle body, and both the front and rear ends of the shaft are mounted on the vehicle body. This is done by connecting it to the steering mechanism, but since the shaft is long, it is necessary to temporarily attach the support member to the vehicle body before connecting it to both steering mechanisms. However, if the support member is formed with an engagement groove extending in the axial direction of the shaft, the protruding member can move within the engagement groove even after the support member is attached to the vehicle body, so the position of the support member and the vehicle body may be affected. It is conceivable that the relationship is not constant, and therefore it becomes difficult to connect the shaft supported by the support member to both the front and rear steering mechanisms. In particular, if the shaft is made up of a plurality of shafts connected to each other, it becomes even more difficult to perform the work, and if the ends of the engagement grooves are open, the shaft may become attached to the supporting member during the work. At the same time, there is a possibility that the vehicle may fall off the vehicle. These phenomena can also occur when the shaft is supported by a support member so as to be slidable in the axial direction of the shaft.

The present invention was devised in view of the above circumstances, and it is possible to easily perform mounting work on a vehicle body even when a support member in which an engagement groove extending in the axial direction of the shaft is formed is adopted. 4 vehicles that can
The present invention aims to provide a wheel steering device.

(Means for Solving the Problems) The four-wheel steering system for a vehicle according to the present invention has hook grooves projecting laterally from the engagement grooves in the support member, so that both the front and rear ends of the shaft can be During the connection work to the steering mechanism, a projection member on the vehicle body side is engaged with the hook groove to maintain a constant positional relationship between the support member and the vehicle body, thereby achieving the above purpose. This is what I did.
That is, a front wheel steering mechanism that steers the front wheels in response to steering wheel steering, a rear wheel steering mechanism that steers the rear wheels in response to the front wheel steering by the front wheel steering mechanism, the front wheel steering mechanism, and the front wheel steering mechanism. A shaft that is connected to the rear wheel steering mechanism and transmits the amount of steering of the front wheels by the front wheel steering mechanism to the rear wheel steering mechanism, and an engagement groove that supports the shaft and extends in the axial direction of the shaft are formed. and a protrusion member provided on the vehicle body that is fitted into the engagement groove and supports the support member so as to be movable in the axial direction of the shaft, and the support member includes: It is characterized in that a hook groove is formed that projects laterally from the engagement groove.

The above-mentioned "engaging groove" may be a long hole or an open groove with one or both ends open, as long as it extends in the axial direction of the shaft.

The above-mentioned "projection member" may be provided integrally with the vehicle body, or may be provided separately by attaching a separate member such as a bolt. In addition, the "projection member" may be a member that fixes the support member after being fitted into the engagement groove, as long as it can support the support member in a movable manner in the axial direction of the shaft. Good and
It may be something that is not done.

The above-mentioned "hook groove" engages with the protrusion member and can maintain a constant positional relationship between the support member and the vehicle body to the extent that it does not interfere with the connection work of the shaft to both the front and rear steering mechanisms. If there is, there are no particular limitations on the position, depth, width, shape, etc. of the side protrusion from the engagement groove.

Note that the above-mentioned "shaft" may be composed of one shaft, or may be composed of a plurality of shafts connected to each other.

(Function) With the above configuration, when connecting the shaft to both the front and rear steering mechanisms, the positional relationship between the support member and the vehicle body can be maintained constant by engaging the protruding member in the hook groove. It is possible to perform the connection work in this state, which improves work efficiency. Then, when this connection work is completed, if the protrusion member is disengaged from the hook groove and positioned within the engagement groove, the four-wheel steering device mounted on the vehicle can be attached to the shaft support member. When an axial load is applied to the support member, it is possible to allow the support member to move relative to the vehicle body in the axial direction of the shaft.

(Effect of the invention) Therefore, according to the invention, when the shaft receives an impact load from the front or rear due to a vehicle collision, etc., a situation where the shaft bends due to the reaction force of the supporting member can be avoided. It is possible to avoid this, and improve the workability when mounting the four-wheel steering device on a vehicle body, and the above effects can be achieved with a simple configuration.

(Embodiments) Hereinafter, embodiments of the present invention will be described 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 of the same, where the left side of both figures is the front part of the vehicle and the right side is the rear part. A front wheel steering mechanism 2 that steers left and right front wheels 1 includes a rack member 4 that converts rotational motion of a steering handle 3 into linear reciprocating motion, and a pinion 5 that converts the linear reciprocating motion into rotational motion. . The rack member 4 is located in front of the dart lower panel 6 and behind the engine 7, and is attached to a bracket 8.
It is supported by the dart lower panel 6 via. 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 to which 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, 16 extending in the longitudinal direction of the vehicle body and disposed within a tunnel portion 14a of a floor member 14 constituting the floor of the vehicle interior. and 17. That is, the front end of the shaft 15 is connected to the pinion 5 of the front wheel steering mechanism 2.
The rear end of the shaft 17 is connected to the steering shaft 20 of the rack and pinion mechanism 13 of the rear wheel steering mechanism 10 by a universal joint 19 to a drive shaft 18 which is provided coaxially with the pinion 5 and rotates with the rotation of the pinion 5. The rear end of the shaft 15 and the shaft 17
The front end of the shaft 16 is connected to the front end and the rear end of the shaft 16 by universal joints 22 and 23, respectively. The plurality of shafts 15,1
6 and 17, the front wheel 1 is controlled by the front wheel steering mechanism 2.
The amount of steering is transmitted to the rear wheel steering mechanism 10, and the amount of steering is transmitted to the rear wheel steering mechanism 10.
is steered at a predetermined steering ratio. In addition,
The structure in which the front and rear wheel steering mechanisms 2 and 10 are connected by a plurality of shafts 15, 16, and 17 is because
This is to avoid the undulations of the floor member 14, the fuel tank 24, etc., and to increase the degree of freedom in layout.

The shaft 16 located between the shafts 15 and 17 is supported by the vehicle body near its front and rear ends to maintain the illustrated position. That is, near the front end of the shaft 16, a U-shaped member 25 (see FIG. 3) is welded to the side surface of the tunnel portion 14a of the floor member 14.
The shaft 16 is rotatably supported slidably in the axial direction of the shaft 16 by a bearing 28 integrally formed with a bracket 27 fixed to the shaft 16 with a bolt 26 (that is, the bracket 27 and the bearing 28 constitute a support member; In the vicinity of the rear end, a bearing 32 integrally formed with a bracket 31 fixed with a bolt 30 to a U-shaped member 29 welded to the upper surface of the tunnel portion 14a of the floor member 14 allows the shaft 16 to be rotated in the axial direction. It is slidably and rotationally supported.

As shown in FIG. 2, the bracket 27 is fastened by the bolt 26 at two places, and grooves 27a and 2, which are engagement grooves that open forward, respectively.
A bolt 26 is passed through 7b and fastened. On the other hand, the bracket 31 is fastened with the bolt 30 by passing the bolt 30 through a circular hole formed in the bracket 31. The brackets 27 and 31 themselves each have sufficient rigidity. Therefore, the fixing strength of the bracket 27 to the vehicle body is determined by the groove portions 27a, 2.
Since the bracket 7b is open to the front, the load from the front is reduced due to the strength of fixing the bracket 31 to the vehicle body.

Both bearings 28 and 32 have a structure shown in an axial cross section in FIG. 4. That is, a plurality of bearing needles 33 arranged around the circumference of the shaft 16, a bearing holder 34 that supports them, an oil seal 35 provided on both sides of this bearing holder 34, and an outer ring 36 that accommodates them. It is made up of

As shown in FIGS. 1 and 2, in front of each portion of the shaft 16 supported by the bearings 28 and 32, there are disk-shaped stopper members 37 and 38 having approximately the same outer diameter as the outer diameter of the bearings 28 and 32. Each is fixed by welding. Both stopper members 37 and 38 are fixed to the shaft 16 in a positional relationship such that the distance A between the bearing 28 and the stopper member 37 and the distance B between the bearing 32 and the stopper member 38 satisfy A<B. .

The shaft 17 is provided with an axial stroke absorption mechanism 39. This axial stroke absorbing mechanism 39 is connected to the shaft 1 as shown in FIG.
7 into front and rear parts, the rear end part of the shaft front part 17a is formed into a cylindrical shape, and the front end part of the shaft rear part 17b is slidably inserted into this, and both parts are connected with a cutting pin 40.
When a predetermined load or more is applied to the shaft 17 in its axial direction, the shaft 17 is contracted by cutting the cutting pin 40, thereby absorbing the stroke.

In FIGS. 1 and 2, when the engine 7 receives an impact force from the front due to a frontal collision of the vehicle and moves backward, and comes into contact with the rack member 4 and pinion 5 that constitute the front wheel steering mechanism 2, the engine 7 A bracket 8 fixed to the pinion 6 and supporting the rack member 4, and a drive shaft 18 extending rearwardly from the pinion 5 are pushed rearward. Bracket 8
When the pressing force acting on the drive shaft 18 exceeds a predetermined value, the dart lower panel 6 that supports it deforms and starts to move backward. On the other hand, when the pressing force acting on the drive shaft 18 exceeds a predetermined value, the shaft 15
and the cutting pin 40 of the stroke absorption mechanism 39 provided on the shaft 17 connected via 16.
is cut, and as the dart lower panel 6 moves backward, the drive shaft 18 also moves backward.

As the drive shaft 18 retreats, the shaft 15 also retreats, and at the same time the bearings 28,
The shaft 16 supported by 32 also slides rearward. However, the rearward sliding of the shaft 16 is
If the pressing force acting on the drive shaft 18 is less than a predetermined value, the support reaction force of the bearing 28 is reduced when the stopper member 37 fixed to the shaft 16 comes into contact with the bearing 28, that is, when the shaft 16 retreats by the dimension A. is prevented by If the pressing force is equal to or greater than the predetermined value, the bolt 26 that is engaged with the groove 27a and fixed to the bracket 27 is inserted into the groove 27.
a relative to the front to separate from the groove 27a,
Shaft 16 continues to move backward. However, the retreat of the shaft 16 is caused by a bearing 3 that is integrally formed with a bracket 31 that is firmly fixed to the vehicle body.
When the stopper member 38 comes into contact with the shaft 16, that is, when the shaft 16 moves backward by the dimension B, the supporting reaction force of the bearing 32 completely stops the movement.

Therefore, the retreat of the darts lower panel 6 is as follows:
If the pressing force acting on this is less than a predetermined value, the shaft 16 will stop when it slides in the A dimension, and if the pressing force is more than the predetermined value, it will stop when the shaft 16 slides in the B dimension. . That is, the retraction distance of the darts lower panel 6 can be kept below dimension B at worst. As is clear from the figure, this B dimension is not a retraction distance of the darts lower panel 6 that would pose a danger to the occupants in the front seat 41, and it goes without saying that it does not pose a danger to the occupants in the rear seat 42. stomach.

In this case, the bracket 27 is designed to separate from the vehicle body with a pressing force greater than a predetermined value, so when the stopper member 37 comes into contact with the bearing 28, the support reaction force of the bearing 28 causes the bracket 27 to be positioned in front of the vehicle body. It is possible to avoid a situation where the shaft 15 bends and deforms the tunnel portion 14a of the floor member 14. On the other hand, since the bracket 31 itself has high rigidity and is firmly fixed to the vehicle body, it is not only possible to reliably prevent the shaft 16 from moving backward by the contact of the stopper member 38 with the bearing 32, but also to prevent the shaft 16 from moving backward. A fuel tank 24 arranged behind the bracket 31
In addition, it is possible to prevent the bracket 31, bearing 32, universal joint 23, etc. from coming into contact with each other, thereby avoiding situations such as damage to the fuel tank 24, and further improving safety.

As shown in Figures 1 and 6, bracket 2
Of the pair of grooves 27a and 27b formed in 7, a hook groove 27c extending upward is formed at the rear end of one groove 27b.

Next, the operation of this embodiment will be explained.

The work of installing the four-wheel steering system on a vehicle is as shown in FIGS. 1 and 2, after mounting the front wheel steering mechanism 2 and the rear wheel steering mechanism 10 on the vehicle body,
5, 16, and 17, but the procedure for installing these series of shafts 15, 16, and 17 is to first attach the bracket 27 of the bearing 28 that supports the front end of the shaft 16 to the vehicle body, and then The procedure is to connect the joint part 19 at 1, then attach the bracket 31 of the bearing 32 that supports the rear end of the shaft 16 to the vehicle body, and then connect the joint part 21. After the bearing 28 is installed, the dimensional relationship A< shown in FIG.
Bracket 2 while making fine adjustments to satisfy B.
7 is tightened with a bolt 26 to be fixed to the vehicle body. That is, the initial attachment of the bearing 28 to the vehicle body is performed as a temporary holdover to facilitate subsequent mounting work.

FIG. 6 is a diagram showing how the bearing 28 is initially attached to the vehicle body.

A bracket 27 is attached to the U-shaped member 25 on the vehicle body side.
The bolt 26 for fixing the U-shaped member 25
The upper screw hole 25b of the pair of upper and lower screw holes 25a and 25b with weld nuts formed in the
It is screwed together with its head raised. The bracket 27 has the bolt 26 in the groove 27.
It is inserted from the open front end of b and is supported by the bolt 26 while abutting against the upper end of the hook groove 27c formed to extend to the rear end, so that it can be temporarily stored. .

As shown in FIG. 7, the front and back width of the hook groove 27c is set to be the same as the diameter of the bolt 26, so that the bracket 27 can be held in the temporarily stored state.
is designed to prevent rattling in the axial direction of the shaft 16.

After carrying out the above-mentioned mounting work in this temporarily stored state, lift the bracket 27 upward, return the bolt 26 from the hook groove 27c to the groove 27b, and then move the bracket 27 onto the shaft 16.
The bearing 28 is movable in the axial direction.
After positioning, the screw hole 25 of the bolt 26 is
b, and then another bolt 26 is tightened into the threaded hole 25a, thereby fixing the bracket 27 to the vehicle body. Two circles indicated by two-dot chain lines in FIG. 7 indicate the positions of the pair of bolts 26 when the bracket 27 is fixed to the vehicle body.

As described in detail above, according to this embodiment, when connecting the series of shafts 15, 16, 17 to the front and rear steering mechanisms 2, 10, the bolts 26 are inserted into the hooks of the brackets 27 as shown in FIG. By engaging with the groove 27c, the bracket 27 can be temporarily stored in the vehicle body without being able to move in the axial direction of the shaft 16. For example, in FIG. When the shaft 15 moves backward in the state shown in FIG.
is removed and the shaft 15,1 is removed together with the bracket 27.
It is possible to avoid a situation where the numbers 6 and 17 fall off. On the other hand, after the four-wheel steering system has been installed on the vehicle body, the bolts 26 are engaged with the grooves 27a and 27b, as shown in FIG. It is possible to improve safety in the event of a vehicle collision, etc.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an example of a four-wheel steering device for a vehicle according to the present invention, FIG. 2 is a side view of the device, and FIG.
The figure is a cross-sectional view taken along the line 2 in Figure 2, Figure 4 is a side cross-sectional view showing the structure of the bearing in detail, Figure 5 is a side cross-sectional view showing the stroke absorption mechanism in detail, and Figure 6 is a section of the part shown in Figure 1. Detailed perspective view, FIG. 7 is a side view showing the bracket in detail. 1...Front wheel, 2...Front wheel steering mechanism, 9...Rear wheel, 10...Rear wheel steering mechanism, 15, 16, 17...
...Shaft, 26... Bolt (protruding member), {27
... Bracket, 28 ... Bearing (supporting member), 27b ... Groove (engaging groove), 27c ... Hook groove (hook groove), 37, 38 ... Stopper member.

Claims (1)

[Scope of utility model registration request] a front wheel steering mechanism that steers the front wheels in response to steering wheel steering; a rear wheel steering mechanism that steers the rear wheels in response to the steering of the front wheels by the front wheel steering mechanism; and the front wheel steering mechanism and the rear wheel steering mechanism. A shaft is connected to the rudder mechanism and transmits the amount of steering of the front wheels by the front wheel steering mechanism to the rear wheel steering mechanism, and an engagement groove that supports the shaft and extends in the axial direction of the shaft is formed. a support member; and a protrusion member provided on the vehicle body that is fitted into the engagement groove and supports the support member movably in the axial direction of the shaft, and the support member includes the engagement groove. A four-wheel steering device for a vehicle, characterized in that a hook groove is formed that projects laterally from a matching groove.