JP2014084885A - Steering device - Google Patents

Abstract

[PROBLEMS] To provide a rolling bearing that rotatably supports a steering shaft, and is suitable for a steering device in which an upper column and a lower column are slidably fitted in an axial direction, and improve steering stability of a steering wheel during high-speed traveling. A steering apparatus is provided.
When a lock nut 61A is tightened and an inner ring 422 of an angular ball bearing 42 is pressed via a disc spring 64 and a preload is applied between the outer ring 421A and the inner ring 422 and between the outer rings 421B and 423, an angular ball bearing is obtained. 42 becomes small, and the rotational torque of the lower steering shaft 32 and the upper steering shaft 31 gradually increases. When the rotational torque of the lower steering shaft 32 and the upper steering shaft 31 reaches a predetermined magnitude, the left lock nut 61B is tightened and brought into close contact with the right lock nut 61A.
[Selection] Figure 4

Description

The present invention relates to a steering device, in particular, a telescopic steering device or a secondary collision in which an upper column and a lower column are slidably fitted in an axial direction to adjust a telescopic position of a steering wheel. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering device that collapses to the front side of a vehicle body and absorbs an impact load, and includes a rolling bearing that rotatably supports a steering shaft.

Since the rolling bearing that rotatably supports the steering shaft has a small frictional resistance and a stable frictional resistance, an extremely smooth steering operation can be performed. However, since rolling bearings have low vibration absorption characteristics, the vibration of the axle caused by road surface undulations during high-speed traveling is directly transmitted to the steering wheel, causing the steering wheel to vibrate slightly in the rotational direction, resulting in a decrease in steering stability. There is.

In the steering device of Patent Document 1, a sliding bearing is attached between an inner peripheral surface of a column and an outer peripheral surface of a steering shaft via an elastic body, thereby applying a frictional resistance to the steering shaft to thereby vibrate the steering wheel. Absorbs and improves steering stability.
However, the steering device of Patent Document 1 is applied to a slide bearing, and is not applied to a rolling bearing.

In the steering device disclosed in Patent Document 2, the outer peripheral surface of the rear end of a steering shaft that is rotatably supported by a rolling bearing is attached to a steering shaft by attaching a cylindrical friction addition member via an O-ring. It gives resistance and absorbs vibration of the steering wheel to improve steering stability. However, the steering device of Patent Document 2 is difficult to apply to a steering device in which an upper column and a lower column are fitted so as to be slidable in the axial direction.

JP-A-9-303387 JP 2005-53292 A

The present invention is suitable for a steering device that includes a rolling bearing that rotatably supports a steering shaft, and in which an upper column and a lower column are slidably fitted in an axial direction, and improves steering stability of a steering wheel during high-speed traveling. It is an object to provide an improved steering apparatus.

The above problem is solved by the following means. That is, the first invention is that the lower column, the upper column fitted to the lower column so as to be slidable in the axial direction, and the bearing provided on the upper side of the upper column are rotated to the upper column. An upper steering shaft that is pivotally supported and has a steering wheel mounted on the rear side of the vehicle body,
A rolling bearing provided on the lower side of the lower column is rotatably supported by the lower column, and is fitted to the upper steering shaft so as to be relatively movable in the axial direction, thereby rotating the steering wheel. Lower steering shaft, which transmits to
The male screw formed on the outer peripheral surface of the lower steering shaft and the lock nut screwed into the male screw are tightened to apply a load to the disc spring inserted between the lock nut and the inner ring of the bearing, and bend the disc. A steering device that presses an inner ring of a rolling bearing via a spring and applies a preload to the rolling bearing.

  A second invention is the steering device according to the first invention, wherein the lock nut is a double nut.

  A third invention is a steering device according to any one of the first to second inventions, wherein a preload is applied to the rolling bearing via a disc spring (elastic body). .

The steering device of the present invention is rotatably supported on the lower column by a rolling bearing provided on the lower side of the lower column, and is fitted to the upper steering shaft so as to be relatively movable in the axial direction. A lower steering shaft that transmits rotation to the wheels, a male screw formed on the outer peripheral surface of the lower steering shaft, and a lock nut screwed into the male screw are tightened to press the inner ring of the rolling bearing, thereby applying a preload to the rolling bearing. ing.

  Therefore, by tightening the lock nut and applying preload to the rolling bearing via the disc spring, the rotational torque of the lower steering shaft and upper steering shaft can be adjusted to a predetermined magnitude. The vibration of the steering wheel can be suppressed, and the steering stability of the steering wheel can be improved. In addition, preload can eliminate radial play and increase handle support rigidity.

  In addition, even if the amount of deflection of the disc spring changes due to wear of the operating part, etc., the preload due to the elastic body function of the disc spring itself remains, so the decrease in the amount of preload is covered, and the initial setting performance is maintained over a long period of time. .

1 is an overall perspective view showing a state in which a steering device according to an embodiment of the present invention is attached to a vehicle. It is a front view of the principal part which shows the steering device of the Example of this invention. It is an expanded sectional view near the rolling bearing of the reference example of the present invention. It is an expanded sectional view near the rolling bearing of Example 1 of the present invention.

  Hereinafter, reference examples and Example 1 of the present invention will be described with reference to the drawings.

FIG. 1 is an overall perspective view showing a state in which a steering device 101 according to an embodiment of the present invention is attached to a vehicle. As shown in FIG. 1, a hollow cylindrical column 102 is attached to a vehicle body, and a steering shaft 104 is rotatably supported on the column 102. A steering wheel 103 is mounted on the steering shaft 104 at the right end (rear side of the vehicle body), and an intermediate shaft 106 is connected to the left end of the steering shaft 104 (front side of the vehicle body) via a universal joint 105.

The intermediate shaft 106 is a solid intermediate inner shaft 106 in which a male spline is formed.
a and a hollow cylindrical intermediate outer shaft 106b in which a female spline is formed. The male spline of the intermediate inner shaft 106a can be expanded and contracted (slidable) with respect to the female spline of the intermediate outer shaft 106b, and the rotational torque. Are fitted so that they can be transmitted.

Furthermore, the vehicle body rear side of the intermediate outer shaft 106 b is connected to the universal joint 105, and the vehicle body front side of the intermediate inner shaft 106 a is connected to the universal joint 107. A pinion that meshes with a rack (not shown) of the steering gear 108 is connected to the universal joint 107.

When the driver rotates the steering wheel 103, the steering shaft 104
The rotational force is transmitted to the steering gear 108 through the universal joint 105, the intermediate shaft 106, and the universal joint 107, and the tie rod 109 is moved through the rack and pinion mechanism to change the steering angle of the steering wheel 110. Can do.

FIG. 2 is a front view of the main part showing the steering apparatus of the embodiment of the present invention. As shown in FIG. 2, the upper column (outer column) 1 is fixed to a vehicle body (not shown) by an upper vehicle body mounting bracket 52. On the vehicle body front side (left side in FIG. 2) of the hollow cylindrical upper column 1, the outer peripheral surface of the hollow cylindrical first lower column (inner column) 21 is axially disposed on the inner peripheral surface of the upper column 1. The telescopic sliding fits tightly.

On the vehicle body front side (left side in FIG. 2) of the first lower column 21, the outer peripheral surface of the hollow cylindrical second lower column (inner column) 22 is formed on the inner peripheral surface of the first lower column 21. They are closely fitted so that they can move in the axial direction. A vehicle body front end of the second lower column 22 is pivotally fixed to a vehicle body (not shown) by a lower vehicle body mounting bracket 51. The outer peripheral surface of the second lower column 22 is clamped to the inner peripheral surface of the first lower column 21 by caulking, and when an impact force is applied to the front side of the vehicle body during a secondary collision, the caulking portion is plastically deformed. The first lower column 21 moves in a collapsed manner relative to the second lower column 22 toward the front side of the vehicle body.

An upper steering shaft 31 is inserted into the shaft center of the upper column 1, and a right end (upper side) of the upper steering shaft 31 is inserted by a bearing (not shown) press-fitted into the right end (upper side) of the inner peripheral surface of the upper column 1. ) Is rotatably supported. A steering wheel 1 in FIG. 1 is disposed at the right end (rear side of the vehicle body) of the upper steering shaft 31.
03 is installed.

A lower steering shaft 32 is inserted into the inner peripheral surface 221 of the second lower column 22, and is lowered by an angular ball bearing 41 press-fitted into the left end (lower side) of the inner peripheral surface 221 of the second lower column 22. The left end (lower side) of the steering shaft 32 is rotatably supported. A male spline (not shown) is formed on the right side of the lower steering shaft 32, and a female spline (on the left side of the upper steering shaft 31).
(Not shown) is movably splined.

FIG. 3 is an enlarged sectional view of the vicinity of the rolling bearing of the reference example of the present invention. As shown in FIG. 3, the right end surface of the outer ring 411 of the angular ball bearing 41 is in contact with a shoulder 222 formed on the inner peripheral surface 221 of the second lower column 22. Further, the right end surface of the inner ring 412 of the angular ball bearing 41 is in contact with a shoulder portion 321 formed on the lower steering shaft 32. The lower steering shaft 32 has a male thread 322 formed on the outer peripheral surface on the left side of the shoulder 321.
Two lock nuts 61A and 61B are screwed.

A first spacer 62 and a second spacer 63 are interposed between the right lock nut 61 </ b> A and the left end surface of the outer ring 411. The first spacer 62 has sufficient rigidity not to bend and deform when the lock nuts 61A and 61B are tightened. The second spacer 63 is made of a material having a small coefficient of friction and having a surface coated with a fluoroethylene resin. Accordingly, when the right lock nut 61A is tightened, the frictional force between the right lock nut 61A and the second spacer 63 is reduced. Therefore, it becomes easy to tighten the lock nuts 61A and 61B with a predetermined tightening torque.

When the lock nut 61A is tightened and the outer ring 411 of the angular ball bearing 41 is pressed through the second spacer 63 and the first spacer 62, and a preload is applied between the outer ring 411 and the inner ring 412, the angular ball The backlash of the bearing 41 is reduced, and the rotational torque of the lower steering shaft 32 and the upper steering shaft 31 is gradually increased. When the rotational torque of the lower steering shaft 32 and the upper steering shaft 31 reaches a predetermined magnitude, the left lock nut 61B is tightened and brought into close contact with the right lock nut 61A.

  The lock nuts 61A and 61B constitute a double nut. In this way, the rotational torque of the lower steering shaft 32 and the upper steering shaft 31 can be adjusted to a predetermined magnitude, so that the steering stability of the steering wheel 103 during high-speed traveling can be improved.

Next, Example 1 of the present invention will be described. FIG. 4 is an enlarged cross-sectional view of the vicinity of the rolling bearing according to the first embodiment of the present invention. In the following description, only structural parts and operations different from the above-described reference example will be described, and redundant description will be omitted.

  Example 1 is an example in which two angular ball bearings of the reference example are used and are combined in a back-to-back state. Here, the configuration of the angular ball bearing 42 will be described. Angular contact ball bearings consist of a combination of one outer ring and one inner ring, rolling element balls and retainers (ball cages). The feature is that the straight line connecting the contact points of the outer ring, the ball, and the inner ring has a certain angle (contact angle) with respect to the radial direction, so that one bearing can receive a load in two directions (radial direction and axial direction). The bearing is also characterized by having a load capacity of moment load by combining two. That is, as shown in FIG. 4, a lower steering shaft 32 is inserted into the inner peripheral surface 221 of the second lower column 22, and the inner peripheral surface 221 of the second lower column 22. The left end (lower side) of the lower steering shaft 32 is rotatably supported by an angular ball bearing 42 that is press-fitted in a state where two are combined back to back at the left end (lower side).

  As shown in FIG. 4, the right end surface of the outer ring 421 </ b> B of the angular ball bearing 42 is in contact with a shoulder 222 formed on the inner peripheral surface 221 of the second lower column 22. Further, the right end surface of the right inner ring 423 of the angular ball bearing 42 is in contact with a shoulder portion 321 formed on the lower steering shaft 32. The lower steering shaft 32 is formed with a male screw 322 on the outer peripheral surface on the left side of the shoulder portion 321, and two lock nuts 61 </ b> A and 61 </ b> B are screwed into the lower steering shaft 32. A disc spring 64 is inserted between the lock nut 61 </ b> A and the angular ball bearing 42.

  Since the inner rings 422 and 423 of the angular ball bearing 42 have sufficient rigidity not to bend and deform when the lock nuts 61A and 61B are tightened, it is easy to tighten the lock nuts 61A and 61B with a predetermined tightening torque. It becomes.

  The lock nut 61A is tightened to load the disc spring 64 and the disc spring 64 is deflected to press the left inner ring 422 of the angular ball bearing 42. When a preload is applied between them, the play of the angular ball bearing 42 is reduced, and the rotational torque of the lower steering shaft 32 and the upper steering shaft 31 is gradually increased. When the rotational torques of the lower steering shaft 32 and the upper steering shaft 31 reach predetermined magnitudes, the left lock nut 61B is tightened and brought into close contact with the right lock nut 61A.

  In this way, the friction of the bearing portion can be adjusted by adjusting the tightening force with the double nut, and the rotational torque of the lower steering shaft 32 and the upper steering shaft 31 can be adjusted to a predetermined magnitude. Vibrations such as shimmies during high-speed traveling can be suppressed, and the steering stability of the steering wheel 103 can be improved. In addition, preload can eliminate radial play and increase handle support rigidity. Further, even if the deflection amount of the disc spring 64 changes due to wear of the operating part, etc., the preload due to the elastic body function of the disc spring 64 itself remains, so that a decrease in the preload amount is covered, and the initial setting performance is maintained for a long time. Be drunk.

In the embodiment described above, the upper column is an outer column and the lower column is applied to the inner column steering device. However, the upper column may be an inner column and the lower column may be applied to the outer column steering device. In addition, in the embodiment, a double nut is used as a lock nut, but it is not limited to this as long as it has a function of preventing the nut from loosening. For example, the nut is caulked, a nylon nut is used, and the thread portion is Any means such as applying an adhesive or using a retainer ring can be used.
The disc spring is used as an example of an elastic body, but a commercially available wire spring, spring washer, rubber, resin, or the like having the same function can be used.

DESCRIPTION OF SYMBOLS 101 Steering device 102 Column 103 Steering wheel 104 Steering shaft 105 Universal joint 106 Intermediate shaft 106a Intermediate inner shaft 106b Intermediate outer shaft 107 Universal joint 108 Steering gear 109 Tie rod 110 Steering wheel 1 Upper column (outer column)
21 First lower column (inner column)
22 Second lower column (inner column)
221 Inner peripheral surface 222 Shoulder 31 Upper steering shaft 32 Lower steering shaft 321 Shoulder 322 Male thread 41 Angular ball bearing 411 Outer ring 412 Inner ring 42 Angular ball bearing (two back to back)
421A Outer ring (left side)
421B Outer ring (right side)
422 Inner ring (left side)
423 inner ring (right side)
51 Lower body mounting bracket 52 Upper body mounting bracket 61A, 61B Lock nut 62 First spacer 63 Second spacer 64 Belleville spring

Claims (3)

  A lower column, an upper column fitted to the lower column so as to be relatively slidable in the axial direction, and a bearing provided on the upper side of the upper column so as to be rotatably supported by the upper column, An upper steering shaft with a steering wheel mounted on the lower column is rotatably supported on the lower column by a rolling bearing provided on the lower side of the lower column, and is fitted to the upper steering shaft so as to be relatively movable in the axial direction. The lower steering shaft that transmits the rotation of the steering wheel to the wheel, the male screw formed on the outer peripheral surface of the lower steering shaft, and the lock nut screwed into the male screw are tightened to be inserted between the lock nut and the inner ring. Apply a load to the disc spring that is Pressing the inner ring of the rolling bearing via the disc spring, the steering apparatus characterized by applying a preload to the rolling bearing.   The steering apparatus according to claim 1, wherein the lock nut is a double nut.   The steering apparatus according to any one of claims 1 to 2, wherein the rolling bearing is configured by using a combination of a plurality of angular ball bearings.

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