JP2002059851A - Tilt steering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce an operation torque of an operation lever of a tilt steering device for a better operation property without expanding a range of operation angles of the operation lever. SOLUTION: A cam 22 rotates relatively to a cam follower 21 by rotating an operation lever around an axis and the cam 22 presses the cam follower 21 against a side plate of a fixing bracket to achieve locking of tilt and telescopic motions. A cam surface 28 includes a second slope part 30 of a relatively gentle slope corresponding to a later part of a clamping stroke of the operation lever. A higher level ratio of the operation lever is employed for only the later part of the clamping stroke to reduce an operation torque.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a tilt steering apparatus capable of tilt adjustment.

[0002]

2. Description of the Related Art There is a tilt steering apparatus in which the height of a steering wheel can be changed in accordance with the physique and driving posture of a driver. Further, in the above-mentioned tilt steering apparatus, there is also a tilt steering apparatus to which a so-called telescopic adjustment function for adjusting a position of a steering wheel along an axial direction of a steering shaft is added. Conventionally, as these tilt steering devices, a support shaft that penetrates a side plate of a fixed bracket fixed to a vehicle and a side plate of a tilt bracket fixed to a column, an operation lever that is rotated around an axis of the support shaft, There is provided a camshaft having a cam surface that presses the side plates of both brackets together with each other as the operation lever rotates in the tightening direction to achieve tilt lock.

[0003]

However, there is a problem that the operating torque of the operating lever when achieving the tilt lock is larger than the operating torque of the operating lever when releasing the tilt lock. This means that as the operating lever is rotated in the tightening direction,
It is considered that since the contact load between the cam surface and the cam follower contacting the cam surface increases, the frictional force between them increases, and the operation torque of the operation lever becomes large, making it difficult to operate.

It is conceivable to reduce the inclination of the cam surface. However, in such a case, the angle range of the turning operation of the operation lever must be increased. It will take a lot. In consideration of the layout space in the vehicle, the above-mentioned angle range is limited, and it is substantially difficult to reduce the slope of the cam surface. The present invention has been made in view of the above problems, and an object of the present invention is to provide a tilt steering device that can improve the operability of an operation lever without increasing the operation range of the operation lever. is there.

[0005]

Means for Solving the Problems and Effects of the Invention In order to achieve the above object, the present invention provides a support shaft penetrating a side plate of a fixed bracket fixed to a vehicle body and a side plate of a tilt bracket fixed to a column, A tilt steering device including an operation lever that is turned around the axis of the support shaft, and a cam surface that presses the side plates of both brackets together to achieve a tilt lock as the operation lever turns in the tightening direction. Wherein the cam surface includes a plurality of gradients corresponding to the rotation stroke position of the operation lever.

[0006] By providing a plurality of slopes, the range of the operation angle of the operation lever is not so large,
The operating force of the operating lever can be reduced. In particular, the slope of the cam surface corresponding to the rear part of the stroke in the tightening direction of the operating lever is made relatively gentle, so that the lever ratio of the operating lever is increased only at the rear part of the tightening stroke of the operating lever to increase the operating torque. Can be reduced.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a longitudinal sectional view of a steering column of a tilt telescopic steering apparatus according to one embodiment of the present invention, and FIG. 2 is a partially broken side view of an operation lever and a mounting portion thereof. Referring to FIG. 1, a tilt telescopic steering apparatus 1 (hereinafter, also simply referred to as a steering apparatus 1) includes a steering column 2 that rotatably supports a steering shaft 1 having a steering wheel fixed to an upper end in an axial direction. Have.

The steering column 2 includes a tube 3 (corresponding to an upper jacket) for rotatably supporting the steering shaft 1 and a tilt bracket 4 fixed to the tube 3. The tilt bracket 4 has a groove shape that opens downward, and its left and right side plates 5 and 6 have
A horizontally long hole 7 extending in the longitudinal direction of the steering column 2 is formed. The fixing bracket 8 is fixed to the vehicle, and includes a pair of side plates 9 and 10 facing each other and an upper plate 11 that connects the middle portions of the upper ends of the side plates 9 and 10 to each other. It is shaped. Each side plate 9,
An elongated vertical hole 12 having an arc shape is formed in 10. 1
Reference numerals 3 and 14 denote mounting stays formed by bending the upper edges of a part of each of the side plates 13 and 14 outward. The mounting stays are not shown, but are inserted through screw insertion holes formed in the mounting stays 13 and 14. The fixing bracket 8 is fixed to the vehicle by the bolt.

Although not shown, a tilt center axis is supported in a support hole formed of a round hole provided in each of the side plates 9 and 10 of the fixed bracket 8, and a lower end of the steering column 2 in the axial direction is a tilt center axis. It is supported swingably around. In addition, telescopic adjustment can be performed by displacing the tilt center axis back and forth into long holes provided in the side plates 5 and 6 of the tilt bracket 4 of the steering column 2. Reference numeral 15 denotes a support shaft through which the side plates 9, 10, 5 and 6 of the fixed bracket 8 and the tilt bracket 4 are integrally inserted. The support shaft 15 supports an operation lever 16 for achieving locking and unlocking of the tilt and the telescoping so as to be integrally rotatable.

Referring to FIG. 2, operation lever 16 has an elongated main body portion 41. A connecting portion 23 is provided at one end of the main body portion 41 so as to be integrally rotatable with a cam 22 described later, and a grip portion 42 for a driver to grip is provided at the other end of the main body portion 41. Reference numeral 43 denotes a stopper plate which is screw-fixed near one end of the main body 41 and abuts on the nut 24, and serves to prevent the nut 24 from rotating. In FIG. 2, reference numeral 21 denotes a cam follower engaged with the cam 22, and reference numeral 25 denotes a shim.

Referring to FIG. 1 again, the support shaft 15 is guided by the vertically long hole 12 and is allowed to swing only vertically with respect to the fixed bracket 8. On the other hand, the horizontally long hole 7 allows the steering column 2 including the tilt bracket 4 to move back and forth with respect to the support shaft 15. The spindle 15 is the head 1
7. A bolt having a body 18 and a screw 19 formed of a cylinder. The body 18 penetrates the side plates 5, 6; 9, 10 of the brackets 4, 8, and the head 17 has a flat washer 20 interposed between the head 17 and the outer surface of the side plate 10 of the fixed bracket 8.

On the other hand, a screw portion 19 of the support shaft 15 and a part of the body portion 18 continuing from the screw portion project outward from the side plate 9 of the fixed bracket 8, and a part of the body portion 18 has an annular shape. The cam follower 21 is fitted. Cam Follower 21
Is in contact with the outer surface of the side plate 9 of the fixing bracket 8. Further, the cam follower 21 has a convex portion inserted into the vertically long hole 12 of the side plate 9, whereby the rotation of the support shaft 15 around the central axis C is restricted by the side plate 9 of the fixed bracket 8.

An annular cam 22 which is in contact with the cam follower 21 is fitted to the screw portion 19 so as to be relatively rotatable.
The connecting portion 23 of the operation lever 16 is connected to the cam 22 so that the operation lever 16 and the cam 22 are rotated integrally. A nut 24 with a flange is screwed into the screw portion 19, and the nut 24 positions the cam 22 in the axial direction of the support shaft 15 via an annular shim 25 and a connecting portion 23 of the operation lever 16. I have. The inner periphery of the annular connecting portion 23 may have, for example, a polygonal shape such as a hexagon or a shape having a two-sided width around the circumference.

The shim 25, the connecting portion 23, the cam 22, and the cam follower 21 are sandwiched between the side plate 9 of the fixed bracket 8 and the nut 24. Operation lever 1
6 is rotated, the cam 22 rotates with respect to the cam follower 21 so that the cam follower 21
5 is pushed or released in the direction of the center axis C of the side plate 5, and is pressed or released from the side plate 9, thereby achieving and releasing the tilt lock and the telescopic lock.

As shown in FIG. 3 (a), a first positioning portion 26 for positioning the cam follower 21 when unlocking is provided on the surface 22a of the cam 22 facing the cam follower 21, and for positioning the cam follower 21 when locking. Of the cam 22 (that is, the center axis C of the support shaft 15) are opposed to each other. With reference to FIGS. 3A and 4, a cam surface 28 is formed between the corresponding first and second positioning portions 26 and 27. On the other hand, FIG.
As shown in FIG. 5, a pair of trapezoidal projections 31 which are in sliding contact with the positioning portions 26 and 27 and the cam surface 28 of the cam 22 are formed on the surface 21a of the cam follower 21 facing the cam 22.

As shown in FIG. 4, the cam surface 28 includes a first slope portion 29 having a relatively steep slope and a second slope portion 30 having a relatively gentle slope. Is located at the rear of the stroke of the operating lever when tightening. According to the present embodiment, by providing the plurality of inclined portions 29 and 30 on the cam surface 28, it is possible to reduce the operating force of the operating lever 16 without significantly increasing the range of the operating angle of the operating lever 16. it can.

In particular, the second slope portion 3 having a relatively gentle slope to the cam surface 26 corresponding to the rear portion of the stroke in the tightening direction of the operation lever 16 where the operation torque tends to increase.
0 is provided, whereby the lever ratio of the operation lever at the rear of the tightening stroke (the displacement of the cam follower 21 and the
As a result, the operating torque can be reduced, and the operability of the operating lever 16 can be significantly improved.

The present invention is not limited to the above embodiment. For example, the cam surface may be provided with three or more different slopes having different slopes. Further, in order to make the operation smoother, a smooth curve may be continued between adjacent slope portions, or the whole may be a smooth curve. Further, the present invention may be applied to a tilt steering device having no telescopic adjustment function, and various other changes can be made within the scope of the present invention.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view of a tilt steering device according to an embodiment of the present invention.

FIG. 2 is a partially broken side view of an operation lever and a mounting portion thereof.

FIG. 3A is a front view of a cam including a cam surface,
(B) is a front view of the surface of the cam follower facing the cam surface.

FIG. 4 is a sectional view schematically showing a cam and a cam follower.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 tilt telescopic steering device 4 tilt bracket 5, 6 side plate 8 fixing bracket 9, 10 side plate 15 support shaft 16 operation lever 19 screw portion 21 cam follower 22 cam 23 connecting portion 24 nut 26 first positioning portion 27 second positioning portion 28 cam surface 29 First graded section 30 Second graded section 31 Projection

Claims (2)

[Claims] 1. A support shaft penetrating a side plate of a fixed bracket fixed to a vehicle body and a side plate of a tilt bracket fixed to a column, an operation lever pivoted around an axis of the support shaft, and tightening of the operation lever. And a cam surface for pressing the side plates of both brackets together with rotation in the direction to achieve a tilt lock, wherein the cam surface has a plurality of slopes corresponding to the rotation stroke position of the operation lever. And a tilt steering device. 2. The tilt telescopic steering apparatus according to claim 1, wherein a slope of a cam surface corresponding to a rear portion of a stroke of the operation lever in a tightening direction is relatively gentle.