JPH0788173B2 - Push-up prevention mechanism for steering device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a mechanism for preventing a steering shaft from being pushed up to the inside of a vehicle compartment in a frontal collision (a head-on collision) in a steering device. In particular, the present invention relates to improvement of a mechanism capable of further increasing the certainty of operation.

[Conventional technology]

2. Description of the Related Art In a steering apparatus for an automobile, it is general to provide a push-up prevention mechanism for preventing the steering shaft from being pushed up to the inside of the vehicle in a head-on collision. As such a mechanism, for example, as described in Japanese Utility Model Laid-Open No. 62-184064, a lower end of a steering shaft having a steering wheel attached to an upper end thereof and a gear box connected to a front wheel are connected by an intermediate shaft. In addition, a sliding mechanism is provided on the intermediate shaft. In this conventional device, the sliding mechanism is contracted against the load on the gear box at the time of a head-on collision to prevent the steering shaft from protruding toward the vehicle compartment.

[Problems to be solved by the invention]

In the above conventional device, when the load acts in the axial direction of the intermediate shaft as designed, a sufficient contraction operation is obtained, but when the load is input from a direction extremely different from the design direction, the sliding mechanism twists. There is a concern that the contraction operation will not be performed sufficiently. On the other hand, when the allowable range of the load input direction is set to be wide, the rigidity in the normal steering operation is insufficient and the responsiveness tends to be insufficient.

The present invention has been made in view of the above-mentioned conventional situation, and can sufficiently secure the rigidity in a normal steering operation, and hence the responsiveness, and absorb the movement of the gear box and the deformation of the frame at the time of a head-on collision, thereby steering. An object of the present invention is to provide a push-up prevention mechanism for a steering device that can surely prevent the push-up of a shaft.

[Means for solving problems]

The present invention includes a steering shaft and a gear box,
An intermediate shaft having first and second universal joints at both ends is connected to each other, and the intermediate shaft is divided into an upper shaft and a lower shaft, and the third shaft is connected to the upper shaft or the lower shaft. The slide body is mounted on either one of the side shafts so as to be slidable in the axial direction, and a stopper portion for restricting axial movement of the slide body is provided on the shaft on which the slide body is mounted. Is connected to the shaft support provided on the body frame via a connecting pin,
It is characterized in that the shaft support portion is deformed together with the body frame rearward of the vehicle body by a predetermined value or more, and the connecting pin is broken when the slide body comes into contact with the stopper portion.

[Action]

According to the thrust-up prevention mechanism of the present invention, when the shaft support together with the body frame is deformed rearward of the vehicle body due to the load at the time of a normal collision, the slide body is moved rearwardly of the vehicle body along with this, and the movement amount becomes a predetermined value. When it reaches, the movement of the slide body is restricted by the stopper portion. When the movement of the slide body is restricted, the connecting pin that connects the slide body and the shaft support portion is broken. As a result, the intermediate shaft is separated from the shaft support portion, and the lower side shaft and the upper side shaft are separated from each other. 3 The universal joint bends to prevent the steering wheel from pushing up.

Further, in the present invention, at the normal time, the lower shaft or the upper shaft is fixed to the vehicle body frame side by connecting the slide body and the shaft support portion with the connecting pin, so that the rigidity in the normal steering operation is sufficiently high. Can be secured,
Therefore, sufficient responsiveness can be secured. Further, the present invention has a structure in which the intermediate shaft is separated from the fixed position of the vehicle body in a direction perpendicular to the axis and bent when an impact load is input and the vehicle body frame is deformed. Operation is not uncertain depending on the direction.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

1 to 4 are views for explaining a push-up prevention mechanism of a steering device according to an embodiment of the present invention.

In FIG. 1 showing the overall structure, a steering shaft 1 is not shown, but the upper portion of the steering shaft 1 is rotatably supported via a bearing by a column tube attached to the vehicle body, and has an upper end. The steering wheel is attached to the. The lower end of the steering shaft 1 is pivotally supported by a support bracket 3 fixed to the dash panel 2 via a bearing 4. This steering shaft 1 and body frame 26
The gear box 5 fixed to the
They are connected via a universal joint 7 and a second universal joint 8. The intermediate shaft 6 includes an upper shaft 9 and a lower shaft 10.
It is divided into two parts, and both are connected by a third universal joint 11.

As shown in FIG. 4, the slide shaft 9a welded to the upper shaft 9 is slidably inserted into the guide shaft 12 connected to the first universal joint 7.

A slide cylinder 14 that constitutes a slide body of the breakaway 13 is axially slidably mounted near the connecting portion between the upper shaft 9 and the slide shaft 9a. 14a and upper shaft 9
A bearing 15 and an oil seal 16 are provided between and.
Further, the upper end side 14b of the slide cylinder 14 is slidably inserted into the guide cylinder 17 fitted and fixed to the guide shaft 12, and faces the stopper surface (stopper portion) 17a at a predetermined interval, Further, a dry metal 18 and an oil seal 19 are provided between them. The slide body of the breakaway 13 is, as shown in FIGS. 3 and 4,
A bracket 20 extending in a direction perpendicular to the axis of the slide cylinder 14 is fixed to the upper surface of the lower end side 14a of the slide cylinder 14. Capsules 21 are arranged on the upper surfaces of the left and right sides of the bracket 20, respectively, and a fitting portion 21a projecting downward of the capsule 21 is fitted in a groove 20a of the bracket 20. Further, the coupling hole 21c formed in the left and right flange portions 21b of the capsule 21 and the coupling hole 20b formed in the bracket 20 communicate with each other, and resin is filled in both coupling holes 21c, 20b. A resin pin (connecting pin) 22 is formed, which connects the bracket 20 and the capsule 21.

A fixing bracket 23 is located on the lower surface of the capsule 21 of the breakaway 13, and both of them are fixed by a bolt 24 inserted into a fixing hole 21d of the capsule 21.
The fixing bracket 23 is bolted and fixed to the vehicle body frame 26 via the support member 25. In this way, the support member 25, the fixing bracket 23, and the capsule 21 fixed to the fixing bracket 23 with the bolts 24 constitute the shaft supporting portion of the present invention, and the shaft supporting portion includes the resin pin 22. Is connected to the bracket 20 that constitutes the slide body.

Next, the function and effect of this embodiment will be described.

In the device of the present embodiment, the vehicle collides with the vehicle body frame 26
Is deformed rearward, this deformation acts on the intermediate shaft 6 from the gear box 5 in the axial direction, and the support member 25,
It acts on the slide cylinder 14 via the fixing bracket 23, the bolt 24, the capsule 21, and the bracket 20, and the slide cylinder 14
Slides up. Then, when the upper end side 14b of the slide cylinder 14 contacts the stopper surface 17a of the guide cylinder 17, the movement of the bracket 20 of the breakaway 13 is stopped, and only the capsule 21 and the fixed bracket 23 are moved.
The load on the resin pin 22 reaches the shear load, which shears and the capsule 21 comes off the groove 20a. Then, the breakaway 13 is separated from the fixed bracket 23 in the direction substantially perpendicular to the axis, and the intermediate shaft 6 is bent at the third universal joint 11 portion as shown by the chain double-dashed line in FIG.

As described above, in this embodiment, when the collision load due to the frontal collision is applied, the breakaway 13 is separated from the fixed bracket 23 and the intermediate shaft 6 is bent, and as a result, the thrust of the steering shaft 1 toward the vehicle interior can be prevented. Here, as described above, in the case of the conventional structure in which the push-up is prevented only by the sliding operation, there is a risk that the sliding mechanism portion may be twisted and the sliding operation may not be reliably performed depending on the load input direction. On the other hand, in this embodiment, the intermediate shaft 6 is divided into two, which are connected by the third universal joint 11, and
The upper side is fixed to the vehicle body by the breakaway 13, and part of the deformation at the time of a head-on collision is absorbed by sliding this vehicle body fixing part, and when the deformation further progresses, the breakaway 13 part is fixed. Since the intermediate shaft 6 is separated from the vehicle body side and bent, the problem of the twisting hardly occurs, the deformation and the load are reliably absorbed, and the reliability of the push-up prevention can be improved.

Further, during normal traveling, the intermediate shaft 6 is securely fixed to the vehicle body frame 26 via the slide cylinder 14, the bracket 20, the capsule 21, the bolt 24, the fixing bracket 23, and the support member 25, so that the rigidity of the portion is increased. There is no problem such as shortage of power or deterioration of responsiveness.

Although the upper side is fixed to the vehicle body frame in the above embodiment, the lower side may be fixed and the lower side portion may be provided with the above-mentioned slide mechanism and breakaway.

〔The invention's effect〕

As described above, according to the push-up prevention mechanism for a steering device of the present invention, the intermediate shaft is divided into two parts, connected by a universal joint, and fixed to the shaft support portion of the vehicle body frame via the slide body, so that the normal traveling is performed. Sometimes the intermediate shaft is securely held to ensure sufficient responsiveness and steerability, but at the time of a head-on collision, the intermediate shaft is separated from the vehicle body fixing part and bent, so that the steering shaft is pushed up toward the passenger compartment. There is an effect that it can be surely prevented and reliability can be improved.

[Brief description of drawings]

1 to 4 are views for explaining a push-up prevention mechanism of a steering device according to an embodiment of the present invention, and FIG. 1 is a side view showing the overall structure thereof, FIG. 2, and FIG.
The drawings are a plan view and a partial sectional side view of the breakaway portion, respectively, and FIG. 4 is a sectional side view of the slide cylinder and the guide cylindrical portion. In the figure, 1 is a steering shaft, 5 is a gear box, 6 is an intermediate shaft, 7 and 8 are first and second universal joints, 9 and 10 are upper and lower shafts, 11 is a third universal joint, and 14 is a universal joint. A slide cylinder constituting a slide body, 17a is a stopper surface (stopper portion), 21, 23, 24 and 25 are capsules, fixing brackets, bolts and support members constituting shaft supporting portions respectively, and 22 is a resin pin (connecting pin). , 26 are adjoining frames.

Claims (1)

[Claims] 1. A steering shaft and a gear box are connected to each other via an intermediate shaft having first and second universal joints at both ends, and the intermediate shaft is divided into an upper shaft and a lower shaft. A third universal joint is connected, and a slide body is axially slidably mounted on either the upper shaft or the lower shaft, and the shaft of the slide body is mounted on the shaft on which the slide body is mounted. A stopper portion for restricting directional movement is provided, and the slide body is deformed to a shaft support portion provided on the vehicle body frame rearward of the vehicle body together with the vehicle body frame by a predetermined value or more, and the slide body serves as the stopper portion. A push-up prevention mechanism for a steering device, wherein the push-up prevention mechanism is connected via a connecting pin that breaks when abutting.