JPH0712825B2 - Telescopic steering device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a telescopic steering device in which a part of a steering column can be telescopically expanded and contracted so that an optimum driving position of a steering wheel can be set.

[Prior Art] In general, a steering wheel of a vehicle is not limited to a tilt type structure in which a driver can set an optimum driving position in the vertical direction within a certain range, and the steering wheel in front of and behind the driver is also used. It often adopts a configuration that telescopically expands and contracts within a certain range in the direction.

In this type of telescopic steering device, the steering column is divided into an upper column and a lower column with a tilt bracket, and the upper column is composed of an inner cylinder and an outer cylinder that are fitted coaxially, and the steering shaft is tilted. It is composed of a tubular body to be connected with a universal joint arranged in the bracket and a shaft rod coaxially fitted to the tubular body, and is provided with a drive mechanism for simultaneously expanding and contracting both of them. . As a drive mechanism,
A device for converting the rotary motion of an electric motor into a linear motion, which mainly uses gears and screws (see, for example, JP-A-60-
No. 18449).

[Problems to be Solved by the Invention] However, in a conventional drive mechanism using a torque transmitting means such as a gear or a screw, an unreasonable force acts on the meshing surface of the gear or the screw that converts the rotational motion into the linear motion. In addition to the difficulty of smooth movement, the wear is severe, and this wear easily causes rattling, which causes the steering wheel to vibrate in the axial direction during traveling, which causes the driver to feel uncomfortable.
Further, in this type of drive mechanism, since the upper column rotates, it is not possible to attach a combination switch such as a signal switch, a lamp switch and a wiper switch to the end of the upper column.

[Means for Solving Problems] In order to solve the above problems, the present invention axially expands and contracts a steering shaft to which a steering wheel is attached and a column jacket coaxially surrounding the steering shaft. It is made possible, and a rotation stopper is provided between the movable-side and fixed-side column jackets, and a screw portion is formed on the outer peripheral surface thereof, and a screw portion which is screwed with the screw portion is formed on the inner peripheral surface. The cylinder body is fitted so that one end thereof is rotatably locked to the outer peripheral surface of the fixed-side column jacket, a ring gear is provided on the outer peripheral surface of the cylinder body, and the ring gear is further rotated in the circumferential direction. A telescopic steering device provided with a driving means is constructed.

[Operation] According to the above configuration of the present invention, when the ring gear rotates the tubular body about the axis via the drive means, the movable side of the movable body is screwed into the threaded portion of the inner peripheral surface of the tubular body. The column jacket expands and contracts in the axial direction. At this time, the movable column jacket has a rotation stopper and can be expanded and contracted in the axial direction without rotating.

[Examples] The present invention will be described below with reference to illustrated examples.

1 is a plan sectional view of an essential part, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is a sectional view taken along the line BB of FIG.

In the figure, 1 is a fixed bracket fixed to the vehicle body,
Reference numeral 2 is a rotary bracket that is rotatably connected to a fixed bracket 1 and a tilt hinge 3. Reference numeral 4 is a universal joint having a trunnion in the fixed bracket 1 that is the same as that of the tilt hinge 3. The steering shaft 6 is a steering shaft which is engaged with the steering shaft 5 at the spline 7. The column shaft 8 has one end fixed to the movable bracket 2 and the column shaft 9 is coaxially fitted to the column jacket 8 in the axial direction. A column jacket which is telescopically engaged, a bearing 10 which supports the steering shafts 5 and 6 in the column jacket 8 and 11 in the column jacket 9, respectively, and a snap ring 1
It is fixed at 2 so that it will not come out of the steering shafts 5 and 6, respectively. 13 is a handle, 14 is a combination switch, and 15 is a switch operating lever.

On the other hand, as a drive mechanism for expanding and contracting the column jackets 8 and 9 and the steering shafts 5 and 6, a threaded portion 16 is formed on the outer peripheral surface of the movable column jacket 9 and is screwed with the threaded portion 16. A cylindrical body 18 having a threaded portion 17 formed on the inner peripheral surface is fitted. One end of the tubular body 18 is rotatably engaged with the fixed column jacket 8 via a bearing 19 and does not move in the axial direction. Further, a ring gear 20 is fitted or formed on the outer peripheral surface of the cylindrical body 18, and the worm wheel 21 of the ring gear 20 is formed.
A worm 22 is provided in mesh with the worm 22, the worm 22 is rotatably attached to an output shaft 24 of an electric motor 23 capable of rotating in the forward and reverse directions directly or through a speed reducer, and the tubular body 18 is centered around the steering shafts 5 and 6. It is freely rotatable. In addition to the worm 22 and the worm wheel 21, the cylindrical body 18 may be rotated by engaging the spur gears 26 and 27 with each other as shown in FIG. Cylinder 18
The rotation of the column jacket 9 prevents the column jacket 9 from rotating following the rotation of the cylindrical body 18. Therefore, as shown in FIG. 3, the rotation stopper pin 28 is attached to the column jacket 9 and the column jacket 9 is rotated. It is provided so as to be fitted in a long hole 29 bored at a constant length in the axial direction of 8.

Explaining the operation of the above embodiment, if the electric motor 23 is started and the worm 22 is rotated in either forward or reverse direction,
The worm wheel 21 causes the cylinder 18 to rotate about its axis, and the threaded portion 17 rotates to cause the column jacket 9 to follow the threaded portion 16 to rotate. The rotation stopper pin 28 of the jacket 9 engages with the long hole 29 of the column jacket 8, and the cylindrical body 18 is rotatably locked to the fixed-side column jacket 8 and cannot move in the axial direction. The jacket 9 moves in the axial direction.
Therefore, if the electric motor 23 is rotated in the normal direction, the column jacket 9 moves in the direction away from the movable bracket 2 and the total length of the column jackets 8 and 9 extends, and vice versa. Then, the column jacket 9 is close to the movable bracket 2 and the total length of the column jackets 8 and 9 can be shortened.

[Effects of the Invention] According to the present invention described above, the steering shaft to which the steering wheel is attached and the column jacket that coaxially surrounds the steering shaft are formed so as to be expandable and contractable in the axial direction, and are movable. A cylindrical body in which a rotation stopper is provided between the fixed-side and fixed-side column jackets, a threaded portion is formed on the outer peripheral surface of the movable-side column jacket, and a threaded portion that is screwed into the threaded portion is formed on the inner peripheral surface. One end of which is rotatably engaged with the outer peripheral surface of the fixed-side column jacket, a ring gear is provided on the outer peripheral surface of the cylindrical body, and drive means for rotating the ring gear in the circumferential direction is provided. Since it is provided, the structure is extremely simple, and since the column jacket on the movable side does not rotate, there is no hindrance to the attachment of the combi switch, etc. The play of meshing at the threaded portion with the ram jacket is pushed downward by the weight of the steering wheel or the like and is offset, so that there is no rattling and the driver does not feel uncomfortable during traveling. Further, since the cylinder body is fitted to the outer peripheral surface of the column jacket, the cylinder body and the ring gear do not move in the axial direction. Therefore, the meshing between the ring gear and the gear on the drive means side always has a constant contact area, so that the rigidity of the gear meshing portion is kept constant. Further, since the size of the gears is sufficient to allow the gears to mesh with each other, the ring gear and the driving means can be downsized.

[Brief description of drawings]

FIG. 1 is a sectional plan view of a main part, FIG. 2 is a sectional view taken along the line AA of FIG. 1, FIG. 3 is a sectional view taken along the line BB of FIG. 1, and FIG. It is a schematic diagram. 5, 6 ... Steering shaft, 7 ... Spline, 8, 9 ... Column jacket, 13 ... Steering wheel, 14 ... Combination switch, 16, 17 ... Screw part, 18 ... Cylindrical body, 20 ...
Ring gear, 21 ... worm wheel, 22 ... worm, 23
… Electric motor, 28… Rotation stop pin, 29… Long hole.

Claims (1)

[Claims] 1. A steering shaft to which a steering wheel is attached and a column jacket coaxially surrounding the steering shaft are formed so as to be expandable and contractable in the axial direction, and between the movable side and fixed side column jackets. A rotation stopper is provided on the movable side column jacket, and a threaded portion is formed on the outer peripheral surface of the movable side column jacket, and a cylindrical body having a threaded portion that engages with the threaded portion is formed on the inner peripheral surface. The telescopic device is characterized in that it is fitted to the outer peripheral surface of the jacket so as to be rotatably locked, a ring gear is provided on the outer peripheral surface of the cylindrical body, and drive means for rotating the ring gear in the circumferential direction is provided. Tsuk steering device.