JP4000783B2 - Tilt steering device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tilt steering apparatus capable of tilt adjustment.
[0002]
[Background Art and Problems to be Solved by the Invention]
Some tilt steering devices are provided with a cam mechanism in order to maintain the position of the adjusted steering column. This cam mechanism presses the side plate of the tilt bracket fixed to the vehicle body and the side plate of the column bracket fixed to the steering column together with the rotation of the operation lever to achieve tilt lock. The cam mechanism includes a cam that rotates integrally with the operation lever, and a cam follower that rotates relative to the cam. When the operation lever is operated, the cam surface and the cam follower surface rotate relative to each other, and the side plates of both brackets move away from each other or approach each other, thereby allowing the tilt lock or the tilt lock to be released. At this time, since the cam surface and the cam follower surface slide with each other, the surfaces are easily worn.
[0003]
In order to suppress sliding friction, the cam mechanism has a rotatable roller provided on the cam, and the outer peripheral surface of this roller and the cam follower surface roll (Japanese Patent Laid-Open No. Hei 6). -219283). The roller is supported via a shaft, and the shaft is slidably held in a support groove of the cam. However, in order to prevent interference between the shaft and the cam follower surface, the roller requires a radius larger than the length corresponding to the cam height, and the roller has been enlarged.
[0004]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a small-sized tilt steering device that solves the above-described technical problems and that can suppress wear of the cam mechanism.
[0005]
[Means for Solving the Problems and Effects of the Invention]
According to the first aspect of the present invention, there is provided a support shaft penetrating the side plate of the tilt bracket fixed to the vehicle body and the side plate of the column bracket provided in the steering column, an operation lever rotated around the axis of the support shaft, The tilt steering device includes a cam mechanism that presses the side plates of the brackets together to achieve tilt lock as the operation lever rotates, and the cam mechanism rotates relative to the operation lever as the operation lever rotates. first and second members to be dynamic, a cam surface formed on the first member, and a roller which thus held in the second member, the rollers are needle roller outer diameter is smaller than the width Tona is, the cam surface includes an inverse slope portion straight in correspondence with the rear part of the stroke of the clamping direction of the operation lever, the second member, the holding groove for holding side by side a plurality of rollers radially The Seen, the roller is Yes so as to roll against the bottom of the cam surfaces and the holding groove of the second member of the first member, that the bottom of the holding groove that is parallel to the inverse gradient portion A tilt steering device is provided.
[0006]
According to this invention, since the roller is in rolling contact with both the first and second members, the frictional resistance during the turning operation of the operation lever can be suppressed, so that the first and second members are worn. Can be difficult. In addition, since the needle rollers that roll on both members are used, the cam mechanism can be reduced in size. Furthermore, the above-described needle rollers can be stably held during tightening .
[0007]
Further, the reverse gradient portion makes it difficult for the roller to roll in the direction of the tilt lock release direction, so that inadvertent lock release can be prevented. In addition, it is possible to change the operating force for causing the roller to roll the reverse gradient portion linearly .
[0008]
Further, the bottom of the holding groove is parallel to the reverse gradient portion. As a result, the load per roller can be lowered in a tilt lock state in which the normal roller is stopped and held for a long time, and as a result, wear can be further suppressed.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a tilt telescopic steering device (hereinafter also referred to as a steering device) according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view of a steering column of the above-described steering apparatus. FIG. 2 is a partial cross-sectional view of the operating lever of the steering device and its mounting portion.
The steering device 60 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, and a vehicle body 61 for attaching the steering column 2 to a vehicle body 61 (partially shown). And a tilt bracket 8 fixed to the head.
[0010]
The steering column 2 includes a tube 3 (corresponding to an upper jacket) that rotatably supports the steering shaft 1 and a column bracket 4 fixed to the tube 3. The column bracket 4 has a groove shape that opens downward, and left and right side plates 5 and 6 are formed with horizontally elongated holes 7 extending in the longitudinal direction of the steering column 2 (the direction perpendicular to the paper surface in FIG. 1). Yes.
The tilt bracket 8 is fixed to the vehicle and has a groove shape that opens downward. The tilt bracket 8 has a pair of side plates 9 and 10 that face 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. Each side plate 9, 10 is formed with an elongated hole 12 having an arc shape. Further, the side plates 9 and 10 are provided with mounting stays 13 and 14 formed by bending a part of the upper edge outward. Although not shown, the tilt bracket 8 is fixed to the vehicle by bolts that are inserted through screw insertion holes formed in the mounting stays 13 and 14.
[0011]
Although not shown, the tilt center axis is supported in a support hole made of a round hole provided in each of the side plates 9 and 10 of the tilt bracket 8. The lower end of the steering column 2 in the axial direction is supported so as to be swingable around the tilt center axis. Further, telescopic adjustment is possible by displacing the tilt center axis back and forth in the long holes provided in the side plates 5 and 6 of the column bracket 4 of the steering column 2.
The steering device 60 is tilted around a support shaft 15 that integrally penetrates the side plates 9 and 10 of the tilt bracket 8 and the side plates 5 and 6 of the column bracket 4 and a central axis C of the support shaft 15. And a cam mechanism for achieving tilt lock and telescopic lock by pressing the side plates of the brackets 4 and 8 with each other as the operation lever 16 is rotated. 50.
[0012]
As shown in FIG. 2, the operation lever 16 has a long main body 41. One end of the main body 41 is provided with a connecting portion 23 that is connected to a cam 22 described later so as to be integrally rotatable, and the other end of the main body 41 is provided with a grip 42 for a driver to hold. . Further, a stopper plate 43 is screwed near one end of the main body 41. The stopper plate 43 abuts on the nut 24 and functions to prevent the nut 24 from rotating.
[0013]
Referring again to FIG. 1, the support shaft 15 is guided by the vertically long hole 12 and is only allowed to swing in the vertical direction with respect to the tilt bracket 8. On the other hand, the horizontally elongated hole 7 allows the steering column 2 including the column bracket 4 to move back and forth with respect to the support shaft 15.
The support shaft 15 is composed of a bolt having a head portion 17, a body portion 18 made of a cylinder, and a screw portion 19. The body 18 passes through the side plates 9 and 10 of the tilt bracket 8 and the side plates 5 and 6 of the column bracket 4, and the head 17 has a plain washer 20 interposed between the outer surface of the side plate 10 of the tilt bracket 8. I am letting.
[0014]
On the other hand, the threaded portion 19 of the support shaft 15 and a part of the body portion 18 continuing to the protruding portion protrude from the side plate 9 of the tilt bracket 8 outward. An annular cam follower 21 is fitted into a part of the protruding body portion 18. The cam follower 21 is in contact with the outer surface of the side plate 9 of the tilt bracket 8. Further, the cam follower 21 has a convex portion that is inserted into the vertically long hole 12 of the side plate 9, and thereby the rotation of the support shaft 15 around the central axis C is restricted by the side plate 9 of the tilt bracket 8.
[0015]
An annular cam 22 is fitted to the threaded portion 19 so as to be relatively rotatable side by side in a direction along the cam follower 21 and the central axis C. A connecting portion 23 of the operating lever 16 is connected to the cam 22 so that the operating lever 16 and the cam 22 are rotated together. In addition, a flanged nut 24 is screwed into the screw portion 19. The nut 24 positions the cam 22 in the axial direction of the support shaft 15 through an annular shim 25 and a connecting portion 23 of the operation lever 15.
[0016]
In the present invention, as shown in FIG. 3, the cam mechanism 50 includes the above-described cam 22 as the first member that rotates relative to the operation lever 16 and the cam follower 21 as the second member. The cam surface 31 formed in the cam 22 and the some roller 51 hold | maintained at the cam follower 21 so that rolling is possible are included. The roller 51 is a needle roller having an outer diameter (dimension L2) smaller than the width (dimension L1), and rolls on the cam surface 31.
As shown in FIG. 1, the shim 25, the connecting portion 23, the cam 22, the roller 51, and the cam follower 21 are sandwiched between the side plate 9 of the tilt bracket 8 and the nut 24. When the operation lever 16 is rotated, the cam 22 is rotated with respect to the cam follower 21, so that the cam follower 21 is advanced and retracted in the extending direction of the central axis C of the support shaft 15 through the rollers 51. Is pressed or released, and tilt lock and telescopic lock are achieved and released.
[0017]
In the present invention, as the operation lever 16 is rotated, the roller 51 is brought into rolling contact with both the cam 22 and the cam follower 21. As a result, the friction resistance during the rotation operation of the operation lever 16 can be suppressed. The cam follower 21 and the roller 51 can be made hard to wear. In addition, since the needle rollers 51 that roll on both the members 21 and 22 are used, the outer diameter of the rollers 51 is substantially equal to the cam height (the amount of movement of the cam follower 21 is the amount of movement of the cam follower 21 and the protrusion height of the protrusion 34 described later). Therefore, the cam mechanism 50 and, consequently, the steering device 60 can be reduced in size. Furthermore, the operating force of the operating lever 16 can be reduced by rolling contact.
[0018]
In addition, the above-described needle roller 51 is not easily collapsed even when receiving a load during locking, and can be stably held. Here, the needle roller 51 may be any roller 51 having an outer diameter smaller than the width (dimension in the direction along the central axis).
As shown in FIG. 3, the cam 22 is formed in a cylindrical shape having a center hole 28 through which the support shaft 15 is inserted, and a cam surface 31 is formed on a surface 30 facing the cam follower 21. A connecting boss connected to the connecting portion 23 is formed on the rear surface of the facing surface 30 so that the operation lever 16 and the cam 22 can rotate integrally.
[0019]
As shown in FIGS. 4 and 5, a plurality of convex portions 34 having a fan shape are formed at equal intervals in the circumferential direction, and a cam surface 31 is formed by the slope of each convex portion 34.
The cam surface 31 includes a flat part 44, a forward slope part 37 with a forward slope, and a reverse slope part 39 that slopes in a reverse direction with respect to the forward slope part 37. Between the forward gradient portion 37 and the reverse gradient portion 39 is the top of the convex portion 34. This top part is formed with a smooth curved surface, and the reverse gradient part 39 and the forward gradient part 37 are connected continuously. The reverse gradient portion 39 has a function of increasing the torque at the time of release. The reverse gradient portion 39 is formed corresponding to the rear portion of the stroke in the tightening direction of the operation lever 16 (see arrow L4). The reverse gradient portion 39 has a length that allows the plurality of rollers 51 to contact each other side by side, and is inclined linearly.
[0020]
On the other hand, the cam follower 21 has a facing surface 45 that faces the cam 22. The facing surface 45 is formed with a holding groove 52 corresponding to the convex portion 34 of the cam 22 and comprising a plurality of concave portions having a fan shape. The holding groove 52 is for holding the roller 51. Both end portions of the holding groove 52 in the circumferential direction restrict movement of the rollers 51 in the circumferential direction. Both ends of the holding groove 52 in the radial direction restrict the movement of the roller 51 in the radial direction. The single holding groove 52 holds a plurality of, for example, two rollers 51 adjacent to each other in the circumferential direction and arranged radially. The bottom 53 of the holding groove 52 is inclined in parallel with the reverse gradient portion 39.
[0021]
In the locked state, as shown in FIG. 5, the holding groove 52 and the reverse gradient portion 39 face each other, and all the rollers 51 are sandwiched between the reverse gradient portion 39 and the bottom 53 of the holding groove 52. When the operating lever 16 is rotated in the release direction from this state, the roller 51 is rolled in contact with the reverse gradient portion 39 of the cam surface 31 and the bottom 53 of the holding groove 52, and the top of the convex portion 34 is placed on the roller 51. You can get over and release it.
In the released state, the holding groove 52 and the flat portion 44 are arranged to face each other. At this time, a part of the roller 51 and the flat part 44 are in contact with each other, but a part of the cam surface 31 and the facing surface 45 may be in contact with each other. Further, the distance between the flat portion 44 and the facing surface 45 is made smaller than the outer diameter of the roller 51, and the flat portion 44 prevents the roller 51 from falling off the holding groove 52. When the operating lever 16 is rotated in the tightening direction from this released state, the roller 51 is rolled by the forward gradient portion 37 of the cam surface 31 and the bottom 53 of the holding groove 52, and the top of the convex portion 34 is placed on the roller 51. You can get over and lock.
[0022]
The reverse gradient portion 39 makes it difficult for the roller 51 to roll in the tilt unlocking direction in the locked state, and further facilitates the roller to roll in the tightening direction. As a result, inadvertent unlocking can be prevented. And if it is the linear reverse gradient part 39, the operation force for making the roller 51 roll the reverse gradient part 39 can be changed to a linear form.
Further, since the holding groove 52 holds the plurality of rollers 51, in particular, since the single holding groove 52 holds the plurality of rollers 51 in proximity, the normal roller 51 stops. Thus, the load per roller 51 can be lowered in a tilt lock state that is held for a long time, and as a result, wear can be further suppressed.
[0023]
Since the needle roller 51 can be stably held in the holding groove 52, the holding groove 52 can be made shallow, which is preferable for downsizing of the cam mechanism 50.
In addition, when the bottom 53 of the holding groove 52 is parallel to the reverse gradient portion 39 and there is a play in the circumferential direction in which the roller 51 can roll and move in the holding groove 52, the operation lever 16 in the tightening direction can be moved. During operation, the roller 51 descends the bottom 53 of the holding groove 52 and retracts deeply, so that the roller 51 can easily get over the convex portion 34 and can be tilt-locked easily. Conversely, when operating in the release direction, the force for releasing can be increased.
[0024]
In addition, since the rollers 51 are held by the holding grooves 52, it is not necessary to use a shaft that supports the rollers 51 or a cage that regulates the interval between the rollers 51. As a result, the roller 51 having a smaller diameter can be used as compared with the case of using a cage. This is because when a shaft or a cage is used, in order to prevent interference between the shaft or the cage and the cam surface 31, it is necessary to hold the roller 51 by the shaft or the cage at a position higher than the cam height. This is because the outer diameter of the is increased. Further, if the holding groove 52 is used, the structure can be simplified.
[0025]
In addition, as a shape of the roller 51, a cylindrical roller may be used and a tapered roller may be used. When using a tapered roller, it is preferable to form the bottom 53 of the holding groove 52 and the cam surface 31 in a curved surface correspondingly. Further, if it is a tapered roller, it can rotate around the central axis C while rolling, so that the operation lever 16 can be operated smoothly. Further, when cylindrical rollers are used, the shape of the bottom 53 of the holding groove 52 and the cam surface 31 can be simplified.
[0026]
As described above, according to the embodiment of the present invention, the rolling of the roller 51 can suppress the wear of the cam mechanism 50 for tilt-locking, and can further reduce the resistance when the operation lever 16 is rotated. Miniaturization can be achieved.
In addition, the needle roller 51 can use bearing parts, and since the outer diameter is usually as small as 5 mm or less, it is comparable to a conventional steering apparatus having a sliding cam mechanism. It can be downsized to a certain extent.
[0027]
In particular, since the roller 51 rolls with respect to the cam 22 and the cam follower 21, the frictional resistance can be lowered.
In the above-described embodiment, the plurality of rollers 51 are held in the single holding groove 52, but the single rollers 51 may be held. In this case, it is preferable to arrange the plurality of rollers 51 equally in the circumferential direction.
The holding groove 52 is provided in the cam follower 21 on the driven side, but is not limited thereto. For example, the relationship between driving and following of the member provided with the holding groove 52 and the cam surface 31 may be reversed. Further, the holding groove 52 may be formed in both the cam 22 and the cam follower 21. In this case, the bottom of one holding groove functions as the cam surface 31.
[0028]
In the above-described embodiment, the steering device 60 is configured as a tilt telescopic steering device. However, the steering device 60 may include only a mechanism for tilt adjustment and omit the mechanism for telescopic adjustment. .
In addition, various design changes can be made without changing the gist of the present invention.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a steering column of a tilt telescopic steering device according to an embodiment of the present invention.
FIG. 2 is a partial cross-sectional view of an operation lever and a mounting portion of the tilt telescopic steering device shown in FIG.
3 is a partial cross-sectional front view of the cam mechanism shown in FIG. 1, showing the same cross section as FIG.
4 is a side view of the cam mechanism of FIG. 3, in which cam followers and rollers are illustrated by solid lines, and a cam surface at a position corresponding to a locked state is illustrated by a one-dot chain line.
5 is a partial cross-sectional view of the cam mechanism of FIG. 3, showing the AA cross section of FIG. 4, with the cam in the tightened state shown by a solid line, and the cam in the loosened state shown by a one-dot chain line.
[Explanation of symbols]
2 Steering column 4 Column brackets 5 and 6 Column bracket side plate 8 Tilt brackets 9 and 10 Tilt bracket side plate 15 Support shaft 16 Operation lever 21 Cam follower (second member)
22 Cam (first member)
31 Cam surface 39 Reverse gradient portion 50 Cam mechanism 51 Roller 52 Holding groove 53 Holding groove bottom 60 Tilt steering device 61 Vehicle body C Center axis L1 Roller width L2 Roller outer diameter L4 Stroke, operation lever tightening direction

Claims (1)

A support shaft penetrating the side plate of the tilt bracket fixed to the vehicle body and the side plate of the column bracket provided on the steering column;
An operating lever that rotates about the axis of the spindle;
In a tilt steering device including a cam mechanism that presses the side plates of both brackets together to achieve tilt lock as the operation lever rotates.
The cam mechanism is
First and second members that rotate relative to each other as the operating lever rotates;
A cam surface formed on the first member;
And a result rollers held in the second member,
Days, Ri Do from needle roller outer diameter is smaller than the width,
The cam surface includes a linear reverse slope portion corresponding to the rear portion of the stroke in the tightening direction of the operation lever,
The second member includes a holding groove that holds a plurality of rollers arranged radially,
The roller is adapted to roll with respect to the cam surface of the first member and the bottom of the holding groove of the second member,
2. A tilt steering device according to claim 1, wherein the bottom of the holding groove is parallel to the reverse gradient portion .

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