JPH01106773A - Telescopic steering device - Google Patents

Abstract

PURPOSE:To reduce the number of necessary parts by making a motor which is assembled in a fixed case and has a hollow rotor engage an inner shaft to reduce a space necessary for fixing an electric telescopic steering device. CONSTITUTION:A motor 5 is fitted in a fixed case 1, and has a hollow cylindrical rotor 5b, which is formed with a driving female trapezoidal screw thread 5d, which engages with a driving male screw thread 3a of an inner shaft 3. Thus when the motor 5 is turned on, the rotor 5b rotates to make the trapezoidal screw thread of the female screw thread 5d function, and the rotary motion of the rotor 5b is thereby transformed into the linear motion of the inner shaft 3. The inner shaft 3 can therefore move telescopically and axially toward the outer shaft 4 to produce an electric telescopic steering device simple in structure and less in the number of required parts.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a telescopic steering device capable of telescopically adjusting the axial length of a shaft of a steering wheel.

[Prior art]

The so-called tilt type and telescopic type are well known as devices that can adjust the position of the steering wheel according to the physique of the driver. A tilt steering device is a device that can adjust the installation inclination angle of a steering wheel, and a telescopic steering device is a device that can adjust the axial length of a steering shaft in a telescopic manner.

Manual telescopic steering devices are disclosed in Japanese Patent Publication No. 59-51471, Japanese Patent Publication No. 61-25581, etc. These components are composed of an inner shaft and an outer shaft fitted onto the inner shaft. It is fixed using a screw mechanism, and its expansion/contraction position is adjusted manually.

In other words, in order to adjust the telescopic position of the steering wheel, it is necessary to manually perform two operations: telescopic and fixing. It was very complicated because it required three operations: , unfixing, expanding/contracting, and fixing.

To solve this problem, an electric telescopic steering device has been devised (Japanese Unexamined Patent Publication No. 18449/1983). FIG. 2 is a sectional view of the device described in the publication, and shows the inner shaft 1 constituting the steering shaft.
5 and the outer shaft 14 are connected by serrations so as to be able to rotate integrally and to be slidable in the axial direction.

The inner shaft 15 has a cylindrical shape, has a threaded inner circumferential surface, and is supported rotatably and immovably in the axial direction by a movable bracket (19) having a hollow disk fixed to the end surface on the steering wheel 16 side via a bearing. has been done. Therefore, the movable bracket 19 and the inner shaft 15 are rotatable,
It also moves integrally with the outer shaft 14 in the axial direction.

The fixed bracket 17 has a cylindrical shape and has a threaded outer peripheral surface.
One end thereof is fixed to the front part of the driver's seat of the vehicle body (not shown), and its outer circumferential surface is threadedly engaged with the inner circumferential surface of the movable bracket 19. Further, a spur gear is formed on the outer peripheral surface of the movable bracket 19, and the pinion shaft 24 meshes with the spur gear. Gear teeth are formed on the pinion shaft 24 at a portion where it meshes with the movable bracket and at one shaft end thereof, and a motor (not shown) disposed on the outer peripheral bracket of the steering shaft is connected to the shaft end. The pinion shafts are engaged, and the rotation of the motor causes the pinion shaft 24 to rotate.

In the electric telescopic pink steering device having the above structure, the pinion shaft 24 rotates, thereby rotating the movable bracket 19 that meshes with the pinion shaft 24, and the bracket 19 moves forward and backward in the axial direction of the steering shaft by screwing with the fixed bracket 17. In addition, the movable bracket 19
The inner shaft 15, which is fixed in the axial direction, moves forward and backward with respect to the outer shaft 14, thereby causing the steering shaft to expand and contract in the axial direction.

[Problem that the invention seeks to solve]

In the above-mentioned electric steering device, the motor is placed outside the steering shaft, which makes the structure of the drive means complicated, requires a large number of parts, and requires a large installation space, which is why it is not very popular. That was the reality. The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a telescopic steering device with a simple structure, a reduced number of parts, and a small installation space.

[Means for solving problems]

A telescopic steering device according to the present invention is a telescopic steering device in which a part of a steering shaft consisting of an inner shaft and an outer shaft is fixed to a case fixed to a vehicle body, and the axial length of the steering shaft can be adjusted telescopically. , an outer shaft rotatably installed inside the case, an inner shaft fitted inside the outer shaft, rotatable integrally therewith, and movable in the axial direction with respect to the outer shaft; a rotor, an inner shaft thereof, an engagement means for converting rotational movement of the rotor into axial movement of the inner shaft, and a motor fitted and fixed in the case. It is characterized by

[Operation] When the motor rotates, the inner shaft is moved toward the steering shaft by means of an engaging means provided inside the hollow rotor and the inner shaft, which converts the rotary motion of the rotor into axial movement of the inner shaft. The outer shaft telescopically slides in the axial direction of the outer shaft. This causes the steering shaft to expand and contract in its axial direction.

〔Example〕

The present invention will be described in detail below based on drawings showing embodiments thereof. FIG. 1 is a sectional view of the telescopic steering device according to the present invention, in which the fixed case l is the fixed case main body 1a.
and motor fixed case lb, fixed case body 1
A has a cylindrical shape and is fixed in the axial direction at the front of the driver's seat of a vehicle body (not shown), and its end face on the side of the steering wheel 11 is flange-connected to the motor fixing case 1b.

The motor fixed case lb has a cylindrical shape with the same diameter as the fixed case main body 1a, the diameter of which is reduced on the steering wheel 11 side, and a bearing 6a is built into the end thereof.

The motor 5 is fitted into a fixed case L, and a coil is wound thereon.
Bearings 6b, 6b are built in the hollow stator 5a, the reduced diameter end of the motor fixed case lb, and the terminal end whose inner peripheral surface is enlarged in diameter from the flange end of the fixed case main body 1a.
This is a direct drive motor consisting of a hollow rotor 5b supported by a rotor 5b, and is particularly characterized by being hollow.

In this embodiment, the rotor 5b has a hollow cylindrical shape, and the rotor 5b has a drive female screw portion 5d of an appropriate length formed with a trapezoidal screw on the inner circumferential surface on the steering wheel 11 side. The threaded portion 5d is screwed into the drive male threaded portion 3a of the inner shaft. Further, the remaining inner circumferential surface of the rotor 5b is expanded in diameter to be larger than the outer diameter of the outer shaft 4, which will be described later.

The inner shaft 3 has serrations 3c and screws 3d on the steering wheel 11 side, and the steering wheel 11 is coupled with the serrations 3c and fastened with the screws 3d. Further, in the intermediate portion of the shaft 3, a driving male screw portion 3a formed of, for example, a trapezoidal screw screws with the rotor 5b.
Further, an axial sliding portion 3b made of, for example, a Hall spline is formed at the end of the shaft opposite to the steering wheel 11. The inner shaft 3 having such a shape has its intermediate portion supported by the bearing 6a.
The shaft end opposite to the steering wheel 11 is supported by an axial sliding portion 4b of the outer shaft 4.

The outer shaft 4 has a hollow portion into which the inner shaft 3 on the steering wheel 11 side is inserted, and the axial sliding portion 3 of the inner shaft 3 is formed on the inner peripheral surface of the hollow portion.
An axial sliding portion 4b is formed that engages with b, so that the inner shaft 3 can freely rotate together with the outer shaft 4, and can also expand and contract in the axial direction with respect to the outer shaft 4.

Further, the outer shaft 4 is adjacent to the bearing 6b built into the fixed case 1, and includes a bearing 6C disposed on the inner circumferential surface of the fixed case whose diameter is reduced in diameter, and a steering portion from the bearing 6c of the fixed case. The shaft is fixed and supported in the axial direction by a bearing (not shown) built into the side.

And the steering wheel 11 of the outer shaft 4
The shaft end on the opposite side is connected to a handle joint (not shown), and further continues to a steering section (not shown) consisting of, for example, a rank and a pion.

The telescopic steering device configured in this manner operates as follows. That is, when a predetermined current is applied to the motor 5 and the rotor 5b rotates, the rotational motion of the rotor 5d is converted into a linear motion of the inner shaft 3 by the action of the trapezoidal thread of the drive female screw portion 5d. In other words, the inner shaft 3 moves forward and backward in the axial direction with respect to the outer shaft 4 in a freely expandable and retractable manner. Further, when the steering wheel 11 is steered, the inner shaft 3 and the outer shaft 4 are slidable in the axial direction by a ball spline and are rotatable together, so that they turn together. Since the inner shaft 3 is inserted into and removed from the outer shaft 4 in this manner, the overall length of the steering shaft, that is, the axial position of the steering wheel 11 can be adjusted.

Although a direct drive motor is used as the motor 5 in this embodiment, the present invention is not limited to this, and any motor such as a DC motor or a stainless steel motor may be used as long as it is hollow.

In addition, in this embodiment, the rotor 5b and the drive female screw portion 5d
Although these are integrated, they may be separated and fastened together with bolts or the like.

Further, the means for engaging the inner shaft 3 and the outer shaft 4 is a ball spline in this embodiment, but it may also be possible to use a serration, a parallel key, a spline, etc., which can rotate freely as a unit and can slide in the axial direction. Any engaging means may be used.

Furthermore, in this embodiment, the means for engaging the rotor 5b and the inner shaft 3 is a trapezoidal screw, but any means such as a ball screw may be used as long as it can convert rotational motion into linear motion.

〔effect〕

As described in detail above, according to the device of the present invention, the axial expansion and contraction of the inner shaft is performed by engagement with the motor built in the fixed case and having a hollow rotor. An electric telescopic pink steering device in which the drive means is concentric with the steering shaft can be provided at low cost and in a small installation space, and the axial expansion and contraction can be performed electrically, so the operability is significantly improved compared to manual operation. Furthermore, by combining appropriate storage means and position control means, a known electric tilt steering device is provided, and after retracting the steering system heel position so as not to become an obstacle when getting off the vehicle, the steering system can be operated at the time of starting driving after getting on the vehicle. The present invention has excellent effects such as being able to be developed into a system that allows a person to return to an optimal position.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention, and FIG. 2 is a sectional view showing a conventional example. ! ...Fixed case 3...Inner shaft 4.
... Outer shaft 5 ... Motor 6 ... Bearing 11 ... Steering wheel patent applicant
Koyo Seiko Co., Ltd. Representative Patent Attorney Noboru Kono

Claims (1)

[Claims] 1. A telescopic steering device in which a part of a steering shaft consisting of an inner shaft and an outer shaft is fixed to a case fixed to a vehicle body, and the axial length of the steering shaft can be adjusted telescopically, an outer shaft that is rotatably installed inside the case; an inner shaft that is fitted inside the outer shaft, is rotatable integrally therewith, and moves axially with respect to the outer shaft; and an inner shaft that is hollow. A rotor, an inner surface thereof, and the inner shaft include an engaging means for converting rotational movement of the rotor into axial movement of the inner shaft, and a motor fitted and fixed in the case. A telescopic steering device characterized by: