JP4403583B2 - Dynamic damper mechanism - Google Patents

Description

  The present invention relates to a dynamic damper mechanism for suppressing vibration of a steering wheel in a telescopic steering device for an automobile.

  Some conventional steering devices include a dynamic damper in order to suppress resonance due to vibrations of the engine or the vehicle body when the vehicle is running or idling. Such a dynamic damper is fixedly disposed on the steering device.

  On the other hand, in the case of the telescopic steering, when the telescopic length is long as shown in FIG. 11 due to the change in the telescopic length, the vibration characteristic is as indicated by symbol A, but when the telescopic length is shortened, the vibration property is indicated by symbol B. As shown in FIG.

  For this reason, for example, when the dynamic damper is set in accordance with a state in which the telescopic length is long, the peak level of the vibration characteristics can be suppressed as indicated by symbol A when the telescopic length is long as shown in FIG. When the telescopic length is shortened, the dynamic damper cannot suppress the vibration level, so that the peak level of the original vibration characteristic appears as shown by symbol B.

On the other hand, in Patent Document 1, a dynamic damper is moved and adjusted in the length direction of the steering column via a link mechanism in accordance with the telescopic length, and the damper frequency characteristic of the dynamic damper is changed. A dynamic damper mechanism is disclosed. As a result, even if the telescopic length changes as shown in FIG. 13, an appropriate vibration reduction effect can always be obtained by the movable dynamic damper. When the telescopic length is long, as shown by the symbol A, the telescopic length Is short, the peak level of the vibration characteristics is suppressed as indicated by the symbol B.
Japanese Patent Laid-Open No. 08-175399

  However, in the steering dynamic damper mechanism according to Patent Document 1, since the steering wheel itself rotates, the dynamic damper is attached to the steering column. For this reason, the mass of the dynamic damper required to suppress the vibration of the steering has increased.

  The present invention has been made in view of the above points, and an object thereof is to provide a dynamic damper mechanism of a telescopic steering device in which the mass of the dynamic damper is made as small as possible with a simple configuration.

  In order to achieve the above object, the present invention is such that a steering wheel shaft that supports a steering wheel is supported so as to be slidable in an axial direction with respect to a column post fixedly held on the vehicle body side and rotatable about the shaft. A dynamic damper mechanism for suppressing vibration of a steering wheel in a telescopic steering device, wherein the dynamic damper is clamped by a spring so as to be movable in the radial direction in the steering wheel, and the axial direction with respect to the steering wheel axis A slide piece that is slidably mounted on the shaft so as not to rotate around the shaft, a guide that supports the slide piece so that the slide piece is arranged at a fixed position in the axial direction of the steering wheel shaft, and a steering wheel Place the dynamic damper halfway through the spring Eccentric cam that is pushed in one direction to adjust the spring constant of the dynamic damper, and is connected to the slide piece arranged in the steering wheel via a wire and interlocked with the axial sliding of the steering wheel shaft And a cam drive mechanism that rotationally drives the eccentric cam.

In the dynamic damper mechanism of the telescopic steering device according to the present invention, preferably, the cam drive mechanism is a rack and pinion mechanism that operates by the advancement and retraction of the wire.
Alternatively, the cam drive mechanism may be composed of a rack and pinion mechanism that operates when the wire advances and retreats and a bevel gear that changes the rotation direction of the pinion. This cam drive mechanism may be configured to directly rotate the rotating shaft of the eccentric cam by the advancement and retraction of the wire. Alternatively, the cam drive mechanism can be configured to transmit the advance / retreat of the wire as a rotational motion to the rotating shaft of the eccentric cam via the hydraulic means.

  According to the present invention, when the steering wheel shaft is slid with respect to the column post in order to adjust the telescopic length, the slide piece is fixed at a fixed position in the axial direction with respect to the column post via the guide. For this reason, it moves in the axial direction relative to the steering wheel axis. Accordingly, since the wire advances and retreats relative to the cam drive mechanism, the cam drive mechanism rotationally drives the eccentric cam by the advance and retreat of the wire. As a result, the eccentric cam is rotationally driven to adjust the spring constant of the dynamic damper.

In this way, the vibration constant of the dynamic damper is adjusted according to the telescopic length by adjusting the spring constant of the dynamic damper in conjunction with the adjustment of the telescopic length.
Therefore, since the vibration absorption frequency of the dynamic damper varies corresponding to the telescopic length to suppress the vibration of the steering, even if the telescopic length changes, the vibration of the steering is always reliably suppressed. Furthermore, since the dynamic damper is provided in the steering wheel, the dynamic damper can exhibit the maximum vibration suppressing effect with the minimum mass.

  Further, when the steering wheel is steered, if the steering wheel and the steering wheel shaft rotate around the shaft, the slide piece also rotates integrally around the shaft as the steering wheel shaft rotates. There is no such thing as wrapping around.

Hereinafter, the present invention will be described in detail based on the embodiments shown in the drawings.
FIG. 1 is a perspective view showing a telescopic steering device 10 having a dynamic damper mechanism according to an embodiment of the present invention. The telescopic steering device 10 includes a column post 11, a steering wheel shaft 12, a steering wheel 13, and a dynamic damper mechanism 20.

  The column post 11 is fixedly arranged on the vehicle body side and is formed in a hollow cylindrical shape, and as shown in FIG. 2, the steering wheel shaft 12 can be rotated about the center via a bearing 11a and slidable in the axial direction. I support it. Here, the rotating portion 11b supported inside the bearing 11a includes a key groove 11c that engages with a key 12a extending in the axial direction along the peripheral surface of the steering wheel shaft 12, and the key groove 11c is a steering wheel. It rotates integrally with the wheel shaft 12.

  The steering wheel shaft 12 is formed in an elongated cylindrical shape, and includes the key 12a described above over a range longer than a region inserted into the column post 11 for adjusting the telescopic length.

  The steering wheel 13 is formed in a large-diameter ring shape, and a central portion that supports the ring-shaped portion is fixed to the tip of the steering wheel shaft 12. When the steering wheel 13 is rotated, the rotating portion 11b of the column post 11 is rotated from the steering wheel shaft 12 through the engagement of the key 12a and the key groove 11c in the rotational direction, and the front wheels are steered via a steering mechanism (not shown). Is done.

As shown in FIG. 1, the dynamic damper mechanism 20 includes a dynamic damper 21, a slide piece 22, a guide 23, an eccentric cam 24, and a cam drive mechanism 25.
As shown in FIG. 1, the dynamic damper 21 is supported in the steering wheel 13 so as to be movable in the radial direction.

  As shown in FIG. 3, the slide piece 22 is formed in a flat cylindrical shape, and is attached to the steering wheel shaft 12 in a region near the column post 11 of the steering wheel shaft 12. Here, the slide piece 22 includes a key groove 22a with which the key 12a of the steering wheel shaft 12 is engaged. The slide piece 22 is supported so as to be slidable in the axial direction with respect to the steering wheel shaft 12 and so as not to rotate around the shaft, that is, to rotate integrally with the steering wheel shaft 12. Furthermore, the slide piece 22 is provided with a guide groove 22b along the circumferential direction on its peripheral surface.

  As shown in detail in FIG. 3, the guide 23 is fixed to the outside of the front end portion of the column post 11. A convex portion 23 a that is bent inward is formed at the tip of the guide 23, and this convex portion 23 a engages with the guide groove 22 b on the peripheral surface of the slide piece 22. Accordingly, the guide 23 holds the slide piece 22 so as not to move in the axial direction when the steering wheel shaft 12 moves in the axial direction, and rotates together with the steering wheel shaft 12 when the steering wheel shaft 12 rotates. The rotation of the slide piece 22 is not hindered.

  As shown in FIG. 4, the eccentric cam 24 is arranged around a rotation shaft 24 a that is transverse to the pushing surface 21 a of the dynamic damper 21 so as to push the dynamic damper 21 from one side in the radial direction of the steering wheel 13. It is rotatably supported. Thereby, when the eccentric cam 24 rotates around the rotation shaft 24 a, the pushing surface 21 a of the dynamic damper 21 is moved and adjusted in the radial direction of the steering wheel 21. Further, the eccentric cam 24 is rotationally driven by a cam driving mechanism 25 described later.

  As shown in FIG. 4, the dynamic damper 21 is configured to sandwich a mass 21b as a central weight from both sides in the radial direction by springs 21c, and a pushing surface 21a that abuts on the outside of the one-side spring 21c. Is adjusted in the radial direction by the rotation of the eccentric cam 24, and each spring 21c is expanded / compressed, whereby the spring constant of each spring 21c is adjusted, and the vibration characteristic of the steering is adjusted in frequency.

The cam drive mechanism 25 is configured, for example, as shown in FIG.
In FIG. 5, the cam drive mechanism 25 includes a rack and pinion mechanism including a rack 25a and a pinion 25b. The rack 25a is disposed laterally with respect to the radial direction of the steering wheel 13, one end of the rack 25a is connected to the wire 26, and the other end is biased by a tension spring 25c as a return spring. The wire 26 is bent through pulleys 26 a, 26 b, 26 c, further bent by a pulley or the like (not shown), and extends to the slide piece 22 along the steering wheel shaft 12, and the tip is fixed to the slide piece 22. Has been.

  Each pinion 25 b is attached to a rotation shaft 24 a of the eccentric cam 24. Thereby, the rack 25a is pulled to the other end side by the tension spring 25c. However, when the wire 26 is pulled relatively in the direction of the arrow X in FIG. 5, the rack 25a resists the tension of the tension spring 25c. Moves to one end, rotates the pinion 25b and the eccentric cam 24, and the eccentric cam 24 pushes the pushing surface 21a of the dynamic damper 21.

  The telescopic steering device 10 of the present embodiment is configured as described above, and the telescopic length is set to an appropriate length by sliding the steering wheel shaft 12 with respect to the column post 11 in order to adjust the telescopic length. Is set. At this time, the slide piece 22 is fixed at a fixed position in the axial direction with respect to the column post 11 via the guide 23, so that the slide piece 22 moves relative to the steering wheel shaft 12 in the axial direction, and the wire 26 advances and retreats relative to the cam drive mechanism 25.

  Therefore, when the pinion 25b rotationally drives the eccentric cam 24 by the advancement and retreat of the wire 26, the eccentric cam 24 pushes the pushing surface 21a of the dynamic damper 21 against the tension of the spring 21c by the rotation driving, or the spring Retreat according to the tension of 21c. As a result, the pushing surface 21a of the dynamic damper 21 is moved and adjusted in the radial direction of the steering wheel 21, and the spring constant of each spring 21c is adjusted in conjunction with the telescopic length by the advance and retreat of the pushing surface 21a in the radial direction. Is done.

  In this manner, the vibration absorption frequency of the dynamic damper varies in accordance with the telescopic length based on the adjustment of the spring constant of each spring 21c, thereby suppressing steering vibration. As a result, like the dynamic damper mechanism according to Patent Document 1 including the movable dynamic damper, good vibration characteristics as shown in FIG. 13 can be obtained in conjunction with the change in the telescopic length.

で与えられる。
ここで、図６に示すようにダイナミックダンパー２１はステアリングホイール１３に取り付けられていることから、コラムポスト１１の根元までのモーメント長はＬ１となる。これに対して、特許文献１に示した従来のダイナミックダンパー機構においては、ダイナミックダンパー２１が図６にて符号Ｄで示すように、コラムポスト１１の中間領域に取り付けられていることから、コラムポスト１１の根元までのモーメント長はＬ２となる。 In general, if the vibration absorption frequency of the dynamic damper 21, that is, the tuning frequency f, is K: elastic coefficient of mass 21b, M: mass, C: constant,

Given in.
Here, since the dynamic damper 21 is attached to the steering wheel 13 as shown in FIG. 6, the moment length to the base of the column post 11 is L1. On the other hand, in the conventional dynamic damper mechanism shown in Patent Document 1, the dynamic damper 21 is attached to the intermediate region of the column post 11 as indicated by reference numeral D in FIG. The moment length to the base of 11 is L2.

で与えられることになり、一定のＦを得るためには、Ｌ１＞Ｌ２であることから、Ｍ２＞Ｍ１となる。これにより、従来と比較して、ダイナミックダンパー２１の質量Ｍ１は、従来の質量Ｍ２のＬ２／Ｌ１と小さくすることができる。 Accordingly, the vibration damping force (moment) F of the dynamic damper 11 is expressed as follows, where the mass of the dynamic damper at each position is M1 and M2, respectively.

In order to obtain a constant F, since L1> L2, M2> M1. Thereby, compared with the past, the mass M1 of the dynamic damper 21 can be reduced to L2 / L1 of the conventional mass M2.

  In this way, even when the telescopic length is set short as shown in FIG. 7A, and when the telescopic length is set long as shown in FIG. By adjusting the movement in the radial direction by the eccentric cam 24 in the steering wheel 13 in conjunction with the change in the telescopic length, an optimal vibration suppressing effect can always be obtained. Furthermore, since the dynamic damper 21 is provided in the steering wheel 13, the dynamic damper 21 can exhibit the maximum vibration suppressing effect with the minimum mass.

  Further, when the steering wheel 13 is steered, if the steering wheel 13 and the steering wheel shaft 12 rotate around the axis, the slide piece 22 and the rotating portion 11b of the column post 11 also move around the axis as the steering wheel shaft 12 rotates. Since it rotates integrally, the wire 26 does not wind around the steering wheel shaft 12, and the steering wheel 13 is smoothly steered.

  In the above-described embodiment, the cam drive mechanism 25 is configured by a rack and pinion mechanism. However, the present invention is not limited to this, and various mechanisms such as those shown in FIGS. 8 to 10 may be employed.

FIG. 8 shows a second configuration example of the cam drive mechanism 25.
The cam drive mechanism 25 shown in FIG. 8 includes a rack 25a, a pinion 25b, and bevel gears 25d and 25e. The rack 25a is disposed along the radial direction of the steering wheel 13. One end of the rack 25a is connected to the wire 26, and the other end is biased by a tension spring (not shown) as a return spring. ing. The wire 26 is bent by a pulley or the like (not shown), extends to the slide piece 22 along the steering wheel shaft 12, and the tip is fixed to the slide piece 22. The pinion 25b has a rotation shaft attached to the rotation shaft of one of the bevel gears 25d and 25e. Further, the other gears of the bevel gears 25 d and 25 e are respectively attached to the rotation shaft of the eccentric cam 24.

  As a result, the rack 25a is pulled to the other end side via a tension spring (not shown). However, when the wire 26 is pulled in the direction of the arrow X in FIG. 8, the rack 25a resists the tension of the tension spring. The rack 25a moves to one end side, rotates the eccentric cam 24 via the pinion 25b and then the gears 25d and 25e, and the eccentric cam 24 pushes the pushing surface 21a of the dynamic damper 21.

FIG. 9 shows a third configuration example of the cam drive mechanism 25.
The cam drive mechanism 25 shown in FIG. 9 includes pulleys 25 f and 25 g and a wire 26. In this case, the tip of the wire 26 is connected to the slide piece 22 side, and the other end is branched into two portions 26a and 26b, and the rotary shafts 24a of the eccentric cam 24 are respectively connected via pulleys 25f and 25g. After being wound around several times, they are further fixed in the steering wheel 13 via tension springs 25h and 25i as return springs.

  As a result, when the wire 26 is pulled relatively in the direction of the arrow X in FIG. 9, the eccentric portions 26a and 26b of the wire 26 are pulled against the tension of the tension springs 25h and 25i. 24 is rotated, and the eccentric cam 24 pushes the pushing surface 21 a of the dynamic damper 21.

FIG. 10 shows a fourth configuration example of the cam drive mechanism 25.
The cam drive mechanism 25 shown in FIG. 10 includes a primary hydraulic cylinder 25j, a hydraulic tube 25k, secondary hydraulic cylinders 25l and 25m, link mechanisms 25n and 25p, and a wire 26. In this case, the tip of the wire 26 is connected to the slide piece 22 side, and the other end is connected to the movable portion of the hydraulic cylinder 25j. When the movable portion of the hydraulic cylinder 25j is driven by the wire 26, the hydraulic pressure change is transmitted to the secondary hydraulic cylinders 25l and 25m via the hydraulic tube 25k. Therefore, the movement of the movable parts of the hydraulic cylinders 25l and 25m is transmitted to the rotating shaft 24a of the eccentric cam 24 via the link mechanisms 25n and 25p, respectively.

  Thus, when the wire 26 is pulled relatively in the direction of the arrow X in FIG. 10, the change in hydraulic pressure due to the movement of the movable portion of the primary hydraulic cylinder 25j is transmitted to the secondary hydraulic cylinders 25l and 25m. By driving these movable parts, the eccentric cam 24 rotates, and the eccentric cam 24 pushes the pushing surface 21 a of the dynamic damper 21.

  As described above, the present invention can be implemented in various forms without departing from the spirit of the present invention. Four configuration examples are given as the cam drive mechanism 25. However, the present invention is not limited to this. For example, if the eccentric cam 24 is driven to rotate around the rotation axis based on the movement of the slide piece 22 in the axial direction, for example, a slide The rotational angle of the eccentric cam 24 may be calculated based on the amount of movement of the piece 22, and the rotational shaft of the eccentric cam 24 may be rotationally driven by a motor, and any configuration can be adopted.

1 is a perspective view showing a telescopic steering device including a dynamic damper mechanism according to an embodiment of the present invention. FIG. 2 is a partially broken enlarged perspective view showing a configuration of a column post in the steering device of FIG. 1. FIG. 2 is a partially enlarged perspective view showing a configuration in the vicinity of a slide piece in the steering device of FIG. 1. It is a schematic sectional drawing which shows the structural example of the dynamic damper in the steering apparatus of FIG. FIG. 2 is a schematic perspective view showing a first configuration example of a cam drive mechanism in the steering device of FIG. 1. It is the schematic explaining the moment of the dynamic damper in the steering device of FIG. 1A is a schematic perspective view showing a case where the telescopic length is long, and FIG. 1B is a schematic perspective view showing a case where the telescopic length is short. FIG. 6 is a schematic perspective view showing a second configuration example of a cam drive mechanism in the steering device of FIG. 1. FIG. 6 is a schematic perspective view illustrating a third configuration example of a cam drive mechanism in the steering device of FIG. 1. FIG. 6 is a schematic perspective view illustrating a fourth configuration example of a cam drive mechanism in the steering device of FIG. 1. It is a graph which shows the change of the vibration characteristic by the change of the telescopic length in the conventional telescopic steering device without a dynamic damper. It is a graph which shows the change of the vibration characteristic by the change of the telescopic length in the telescopic type steering device provided with the conventional fixed dynamic damper. It is a graph which shows the change of the vibration characteristic by the change of the telescopic length in the telescopic type steering device provided with the conventional movable dynamic damper.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Telescopic type steering apparatus 11 Column post 11c Key groove 12 Steering wheel shaft 12a Key 13 Steering wheel 20 Dynamic damper mechanism 21 Dynamic damper 21a Pushing surface 21b Mass 21c Spring 22 Slide piece 22a Key groove 22b Guide groove 23 Guide 23a Tip 24 Eccentricity Cam 24a Rotating shaft 25 Cam drive mechanism 26 Wire

Claims (5)

The above-mentioned steering wheel in a telescopic steering device in which a steering wheel shaft that supports the steering wheel is supported so as to be slidable in the axial direction and rotatable about the shaft with respect to a column post fixedly held on the vehicle body side A dynamic damper mechanism for suppressing vibrations of
A dynamic damper sandwiched by a spring so as to be movable in the radial direction in the steering wheel;
A slide piece mounted so as to be slidable in the axial direction with respect to the steering wheel shaft and not to rotate around the shaft;
A guide that supports the slide piece so that the slide piece is disposed at a fixed position in the axial direction of the steering wheel shaft;
An eccentric cam that is disposed in the steering wheel and pushes the dynamic damper to one side in the radial direction via the spring to adjust a spring constant of the dynamic damper;
A cam drive mechanism disposed in the steering wheel, connected to the slide piece via a wire, and configured to rotate the eccentric cam in conjunction with axial sliding of the steering wheel shaft. This is a dynamic damper mechanism.   2. The dynamic damper mechanism according to claim 1, wherein the cam drive mechanism is a rack and pinion mechanism that is operated by advancing and retreating of the wire.   2. The dynamic damper mechanism according to claim 1, wherein the cam drive mechanism includes a rack and pinion mechanism that operates by the advancement and retraction of the wire, and a bevel gear that changes a rotation direction of the pinion. 3.   2. The dynamic damper mechanism according to claim 1, wherein the cam driving mechanism is configured to directly rotate a rotating shaft of an eccentric cam by the advancement and retraction of the wire.   2. The dynamic damper mechanism according to claim 1, wherein the cam drive mechanism is configured to transmit the advance / retreat of the wire as a rotational motion to a rotation shaft of the eccentric cam via a hydraulic unit.

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