JPH0224696Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a telescoping shaft joint used in a vehicle steering column or the like.

In recent years, passenger cars have been equipped with steering columns equipped with an energy absorption mechanism to reduce the impact load by contracting the steering column when the driver collides with the steering wheel in the event of a vehicle collision, for the safety of the driver. In addition, the steering column is equipped with a tilt mechanism that adjusts the angle of inclination of the steering wheel to adjust the position of the steering wheel according to the driver's driving posture, and a telescopic mechanism that allows the steering column to be adjusted freely in the axial direction. has been done. In the case of a steering column equipped with such an energy absorption mechanism and a telescopic mechanism, a shaft body with an irregular cross section and a tube body are fitted and connected as a telescopic shaft joint to enable relative sliding in the axial direction. is equipped with a steering shaft that transmits rotation. By the way, although such a steering shaft normally slides in a locked position except when the telescopic mechanism is adjusted to expand or contract, in a so-called secondary collision when the vehicle collides and the occupant hits the steering wheel, the steering shaft may move in the axial direction. The steering shaft slides and absorbs the impact energy, but at this time, the telescopic shaft joint of the steering shaft slides and bottoms out, and then the energy absorption mechanism contracts. In this case, a reaction force is generated due to the bottoming of the telescopic mechanism, resulting in an excessive impact load.
Therefore, as shown in FIG. 2, a damper 7 made of an elastic body is fitted onto the shaft body 2 and is locked with a stopper 9 such as a snap spring. Since it only fits into the damper 7, the stopper 9 may come off when the end surface 4a of the tube body 4 collides with it, or the end surface 4a of the tube body 4 may become sharp and have a small cross-sectional area and bite into the damper 7, causing damage to the damper. There were cases where it was not useful.

The present invention was developed based on the above-mentioned conventional problems, and consists of a steering column that is attached to the vehicle body, an upper shaft that is rotatably supported by the steering column and that fixes the steering wheel to its upper end, and a lower shaft that is slidably fitted into the shaft and connected to the gearbox via a joint at the lower end; the upper shaft is formed by a lower shaft connected to the lower shaft;
In a steering column device consisting of an intermediate shaft fixed to the lower shaft and an upper shaft fitted in a slidable manner into the intermediate shaft, the steering column device is formed of a partially cylindrical elastic body with hollow portions at both ends. The above-mentioned problem can be solved by fitting the damper with one hollow part in contact with the upper end of the lower shaft in the lower part of the intermediate shaft, thereby eliminating the above-mentioned problems without impairing the load mitigation in the event of a collision. purpose.

1, 3, and 4 show a telescopic shaft joint device according to the present invention. Reference numeral 1 denotes a steering column, which is composed of an upper tube 1a and a lower tube 1b. A bracket 3 is fixedly attached to the vehicle body A so as to be movable axially downward. 5 is a steering shaft, and the steering shaft 5 is rotatably supported within the steering column 1. The steering shaft 5 consists of an upper shaft 6 and a lower shaft 8, and these upper shaft 6 and lower shaft 8 transmit rotation by fitting together in a shape of a shaft tube, but can move in the axial direction when an excessive load is generated in the axial direction. It is becoming. A steering wheel 10 is fixed to the upper end of the upper shaft 6, and the lower end of the lower shaft 8 is connected to a gear box (not shown) via a joint J or the like. The upper shaft 6 is equipped with a telescoping shaft joint mechanism, so that the axial position of the steering wheel 10 can be variably adjusted. The telescopic shaft joint mechanism is explained in detail in FIG. 3. The upper shaft 6 has an upper shaft 11, an intermediate shaft 1
2. The lower shaft 13 has a lower end fitted and connected to the lower shaft 8 as described above, and an upper end fitted and fixed to the intermediate shaft 12. Intermediate shaft 1
The upper end of 2 is connected to the upper tube 1 through a bearing 15.
It is rotatably supported with respect to a. Intermediate shaft 1
A female serration 16 is formed on the inner wall of the shaft 2, and an upper shaft 11 formed with a male serration 17 that meshes with the female serration 16 is fitted to be slidable only in the axial direction. A hole 12 is provided in the lower part of the intermediate shaft 12.
a, 12a are bored to vent air when the upper shaft 11 slides in the axial direction. Further, a guide 12b is formed at the upper end to be bent toward the center and abut against the outer periphery of the upper shaft 11 to prevent the upper shaft 11 from slipping out and to prevent dust from entering. The upper shaft 11 has a hollow hole 11a into which an adjustment rod 18 is inserted, and a threaded portion 18a is formed at the upper end of the adjustment rod 18, and an adjustment lever 19 is screwed and fixed thereto. A stopper 20 having a serration 21 having the same shape as the male serration 17 formed on the upper shaft 11 on the outer periphery is screwed onto the lower end of the adjustment rod 18 . Further, the stopper 20 has an eccentric amount with respect to its axial center, and has a tapered protrusion 20a centered on this eccentric amount, which bites into the end face of the hollow hole 11a of the upper shaft 11. ing. The upper end of the upper shaft 11 is formed with a fixing portion 11b to which the steering wheel 10 is fixed as described above. Reference numeral 22 denotes a damper made of an elastic body, and has hollow portions 22a,
The damper 22 has a partially cylindrical shape with a diameter 22a, and is seated so as to fit inside the lower end of the intermediate shaft 12 so that one end of the damper 22 comes into contact with the upper end surface 13a of the lower shaft 13.

As a result of the above configuration, its operation will be explained. During normal driving, the stopper 20 is adjusted by rotating the adjustment lever 19 in order to match the driver's driving posture.
moves in the axial direction to connect the stopper 20 and the upper shaft 11.
The amount of eccentricity between the upper shaft 11 and the backlash between the male serrations 17 and 21 and the female serrations 16 is offset.
is in a state where it can slide on the intermediate shaft 12 together with the stopper 20, and when the operator is in an appropriate driving position, the operator performs the opposite operation to the above, that is, reverses the adjustment lever 19 and screws the adjustment rod 18 and the stopper 20 together. When the stopper 20 rotates in the tightening direction, the protrusion 20a of the stopper 20 bites into the hollow hole 11a of the upper shaft 11, and the stopper 2
A radial deviation occurs with respect to the upper shaft 11 by an amount of eccentricity of 0, and the upper shaft 11 and the intermediate shaft 12 slide and lock.
If the vehicle collides in this state, the driver collides with the steering wheel 10, and due to this collision force, the upper shaft 11 and the intermediate shaft 12 move in the axial direction, although they are in a sliding lock, and the stopper 20 is moved. The lower surface portion 20b comes into contact with the damper 22. In this case, the damper 22 includes a hollow portion 22a,
22a is formed, so that the cylindrical portion 2 of the damper 22
2b, 22b can be transformed into hollow parts 22a, 22a.

As is clear from the above description, even if the upper shaft moves to the bottom of the intermediate shaft and bottoms out during a collision or sliding position adjustment, the damper is always used, so no metal contact occurs and the collision force is alleviated. In addition, since the damper is formed of a partially cylindrical elastic body with hollow parts at both ends, when the upper shaft collides with the damper, the damper deforms so that the hollow part disappears and absorbs the impact, allowing the bottom of the upper shaft to absorb the impact. No excessive impact load will be generated due to attachment. Moreover, the damper does not come off, there is no need for a stopper, and there is no need to form a groove in the upper shaft into which the stopper is fitted.

[Brief explanation of the drawing]

Figure 1 is a side view of a typical steering device.
FIG. 2 is a sectional view of a main part of a conventional telescopic shaft joint, FIG. 3 is a sectional view of a main part of a telescopic shaft joint of the present invention, and FIG. 4 is a perspective view showing the structure of a damper. 1... Steering column, 5... Steering shaft, 10... Steering wheel, 1
1... Upper shaft, 12... Intermediate shaft, 13... Lower shaft, 22... Damper.

Claims (1)

[Scope of utility model registration request] A steering column is attached to the vehicle body, an upper shaft is rotatably supported by the steering column and fixes the steering wheel to the upper end thereof, and a gearbox is slidably fitted to the upper shaft and is connected to the gearbox via a joint at the lower end. a lower shaft connected to the upper shaft, and a steering shaft formed of a lower shaft connected to the lower shaft, an intermediate shaft fixed to the lower shaft, and a steering shaft that can be slidably fixed within the intermediate shaft. In a steering column device comprising a fitted upper shaft, a damper formed of a partially cylindrical elastic body having hollow portions at both ends is provided, and one hollow portion is applied to the upper end of the lower shaft in the lower part of the intermediate shaft. A telescopic shaft joint that is characterized by being fitted in contact with each other.