JP2006036047A - Electric steering column device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric steering column device having an electric motor capable of quiet operation.
A deep groove radial ball bearing 684 is applied with preload and assembled to an intermediate portion 64B of a rotary shaft 64, so that a gap between the balls of the deep groove radial ball bearing 684 and the inner and outer rings is completely formed. Therefore, even if there is vibration of the rotating shaft 64 itself of the electric motor 6, fluctuations in the load applied to the ball nut 73, and fluctuations in the reaction force acting on the worm gear 66, quiet tilt position adjustment is possible.
[Selection] Figure 7

Description

  The present invention relates to an electric steering column apparatus, and more particularly to an electric steering column apparatus that can adjust a tilt position or a telescopic position of a steering wheel by an electric motor.

  It is necessary to adjust the tilt position and telescopic position of the steering wheel according to the driver's physique and driving posture, and this tilt position or telescopic position can be adjusted easily using an electric motor. More and more steering column devices have been adopted. As such an electric steering column apparatus, there are electric steering column apparatuses disclosed in Patent Document 1 and Patent Document 2.

  FIG. 8 is a cross-sectional view of an electric motor used in a conventional electric steering column apparatus. As shown in FIG. 8, the electric motor 6 having a conventional speed reduction mechanism has a bottomed cylindrical motor case 61, and a magnet 62 is fixed to the inner peripheral surface 611 of the motor case 61. Inside the magnet 62, an armature 63 having a rotor core and a rotor coil is rotatably accommodated.

  The armature 63 has a rotation shaft 64 at its axis. The motor case 61 also serves as a yoke for the magnet 62, and a housing 65 indicated by a two-dot chain line is coupled to the right end of the motor case 61 by a bolt (not shown). A worm gear 66 is integrally formed on the outer periphery of the front end of the rotating shaft 64 (on the right side in FIG. 8), and the worm gear 66 extends into the housing 65. The worm gear 66 meshes with a worm wheel (not shown) to form a speed reduction mechanism, which reduces the rotation of the electric motor 6 and transmits it as a column tilt motion or telescopic motion.

  In addition, a commutator 67 is formed on the rotating shaft 64, and power is supplied to the armature 63 via a brush 671 that is in sliding contact with the commutator 67. The rotary shaft 64 is rotatably supported by slide bearings 681, 682, and 683 at three positions, that is, a rear end portion (left side in FIG. 8) 64A, an intermediate portion 64B, and a front end portion (right side in FIG. 8) 64C.

  As shown in FIG. 8, in the electric motor 6 having a conventional speed reducing mechanism, the rotary shaft 64 is all supported by the slide bearings 681, 682, 683, so that the rotary shaft 64 and the slide bearings 681, 682, 683 are A gap is inevitably generated between the two. Due to this gap, the rotating shaft 64 strikes the plain bearings 681, 682, 683 due to vibration of the electric motor 6 itself, load fluctuation, reaction force acting on the worm gear 66, etc., and quiet tilt position adjustment, or The telescopic position cannot be adjusted. In particular, since the electric steering column device is disposed at a position closest to the driver, it has been desired to perform a quiet adjustment operation of the steering wheel.

International Publication No. WO03 / 078234 Pamphlet Japanese Utility Model Publication No. 5-29979

  An object of the present invention is to provide an electric steering column device having an electric motor capable of quiet operation.

  The above problem is solved by the following means. That is, the first invention is a steering shaft on which a steering wheel is mounted on the rear side of the vehicle body, the steering shaft is rotatably supported, and the tilt position is adjusted with the tilt center axis as a fulcrum, or the steering shaft Electric column equipped with a telescopic position adjustable along the central axis of the motor, an electric motor, and an electric motor equipped with a speed reducing mechanism that decelerates rotation of the rotating shaft of the electric motor and transmits it as tilt motion or telescopic motion of the column In the steering column device, the electric motor is an electric steering column device in which at least one of the bearings supporting the rotating shaft is a rolling bearing.

  According to a second aspect of the invention, in the electric steering column apparatus of the first aspect, the rotation shaft of the electric motor and the input shaft of the speed reduction mechanism are formed on the same axis, and the rotation shaft and the input shaft are supported. The electric steering column device is characterized in that at least one of the bearings is a rolling bearing.

  According to a third aspect of the invention, in the electric steering column device of the first or second aspect of the invention, the rolling bearing is formed of a deep groove ball bearing or an angular ball bearing. This is an electric steering column device.

  A fourth invention is the electric steering column apparatus according to any one of the first to third inventions, wherein the rotating shaft and the input shaft are integrally formed. It is.

  A fifth aspect of the invention is the electric steering column apparatus according to any one of the first to fourth aspects of the invention, wherein a worm gear is formed on the input shaft, and the column is tilted via a worm wheel meshing with the worm gear. An electric steering column device is characterized in that motion or telescopic motion is transmitted.

  In the electric steering column apparatus of the present invention, at least one of the bearings that support the rotating shaft of the electric motor having the speed reduction mechanism is a rolling bearing, so that a fitting gap between the rotating shaft and the bearing is eliminated. Therefore, it is possible to perform a quiet tilt position adjustment or a telescopic position adjustment.

* 1st Embodiment Hereinafter, the 1st Embodiment of this invention is described based on drawing. FIG. 1 is an overall perspective view showing a state in which an electric steering column apparatus 1 of the present invention is attached to a vehicle. The electric steering column apparatus 1 pivotally supports a steering shaft 2 so as to be rotatable. A steering wheel 3 is attached to the steering shaft 2 at the right end (vehicle body rear side), and a lower shaft 102 is connected to the left end (vehicle body front side) of the steering shaft 2 via a universal joint 101.

  A universal joint 103 is connected to the lower end of the lower shaft 102, and a steering gear 104 including a rack and pinion mechanism is connected to the universal joint 103.

  When the driver rotates the steering wheel 3, the rotational force is transmitted to the steering gear 104 via the steering shaft 2, the universal joint 101, the lower shaft 102, and the universal joint 103, and the tie rod is transmitted via the rack and pinion mechanism. 105 can be moved to change the steering angle of the wheel.

  FIG. 2 is a schematic configuration diagram of a main part including a partial cross section showing the electric tilt type steering column apparatus according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view taken along the line AA of FIG. FIG. 4 is an explanatory diagram illustrating a tilt operation according to the first embodiment.

  On the left side (front side of the vehicle body) of FIG. 2, an attachment portion 511 formed on the upper portion of the T-shaped lower vehicle body attachment bracket 51 is fixed to the vehicle body 53, and the pivot portion 512 is downwardly moved from the attachment portion 511. It extends. The left end of the column 4 is swingably supported by the lower vehicle body mounting bracket 51 with a pivot pin 513 pivotally supported by the pivot portion 512 as a fulcrum.

  On the right side (rear side of the vehicle body) in FIG. 2, an attachment portion 521 formed on the upper portion of the L-shaped upper vehicle body attachment bracket 52 is fixed to the vehicle body 53, and the column support portion 522 is downward from the attachment portion 521. It extends to. As shown in FIG. 3, the column support portion 522 has a long hole 523 that is long in the vertical direction, and the right end of the cylindrical column 4 extends to the right side through the long hole 523 to adjust the tilt position. Sometimes, the right end of the column 4 can freely move up and down in the slot 523. A steering shaft 2 is pivotally supported on the column 4, and a steering wheel 3 is mounted on the steering shaft 2 at the right end (rear side of the vehicle body).

  A U-shaped bracket 41 is integrally formed on the left side surface of the column 4, and the electric motor 6 is fixed to the bracket 41. In addition, the upper and lower ends of the ball screw 71 are pivotally supported by the upper shaft support portion 41A and the lower shaft support portion 41B of the bracket 41 via rolling bearings (not shown).

  A worm gear 66 is formed integrally with the rotating shaft 64 of the electric motor 6, and a worm wheel 72 fixed to the ball screw 71 is engaged with the worm gear 66. The worm wheel 72 and the worm gear 66 constitute a speed reduction mechanism, and the rotation of the electric motor 6 is decelerated and transmitted to the ball screw 71.

  A ball nut 73 that converts the rotation of the ball screw 71 into a linear motion is screwed into the ball screw 71. The feed mechanism composed of the ball screw 71 and the ball nut 73 includes a plurality of balls interposed between the spiral groove on the outer periphery of the ball screw 71 and the spiral groove on the inner periphery of the ball nut 73. This is a feed mechanism that converts the rotation into a linear motion of the ball nut 73.

  Since the ball is interposed, there is no backlash between the ball screw 71 and the ball nut 73, so the column 4 has no backlash and the steering wheel 3 feels good. In addition, since the feed resistance is small and the variation in the feed resistance is small, the tilt position can be adjusted smoothly.

  A ball 74 having a spherical projection is integrally formed on the ball nut 73 on the right side of FIG. A cylindrical sleeve 75 is integrally formed on the left end surface 522A (as viewed from FIG. 2) of the column support portion 522, and the outer periphery of the ball 74 is slidably fitted into the inner periphery 75A of the sleeve 75. It constitutes a spherical joint.

  FIG. 7 is a cross-sectional view of the electric motor 6 according to the embodiment of the present invention. The electric motor 6 has a bottomed cylindrical motor case 61, and a magnet 62 is fixed to an inner peripheral surface 611 of the motor case 61. Inside the magnet 62, an armature 63 having a rotor core and a rotor coil is rotatably accommodated.

  The armature 63 has a rotation shaft 64 at its axis. The motor case 61 also serves as a yoke for the magnet 62, and a housing 65 indicated by a two-dot chain line is coupled to the right end of the motor case 61 by a bolt (not shown). On the outer periphery of the front end (right side in FIG. 7) of the rotating shaft 64, the worm gear 66 described above is formed integrally with the rotating shaft 64, and the worm gear 66 extends into the housing 65. The worm gear 66 meshes with the worm wheel 72 to constitute a speed reduction mechanism, and the rotation of the electric motor 6 is reduced and transmitted to the ball screw 71.

  In addition, a commutator 67 is formed on the rotating shaft 64, and power is supplied to the armature 63 via a brush 671 that is in sliding contact with the commutator 67. The rotating shaft 64 is rotatably supported by slide bearings 681 and 683 at both ends of a rear end portion (left side in FIG. 7) 64A and a front end portion (right side in FIG. 7) 64C. The intermediate portion 64B of the rotary shaft 64 is rotatably supported by a rolling bearing such as a deep groove radial ball bearing 684. Since the intermediate part 64B is the place where the reaction force of the load acting on the worm gear 66 is the largest, the effect is greatest when at least one part is a rolling bearing. However, all the sliding bearings are made to be rolling bearings. Also good.

  In addition, the rotation shaft 64 may be supported by two places, that is, the rear end portion 64A and the front end portion 64C, or only two places of the rear end portion 64A and the intermediate portion 64B. What is necessary is just to pivotally support a place with a rolling bearing.

  The deep groove radial ball bearing 684 can be completely eliminated from the gap between the balls and the inner and outer rings of the deep groove radial ball bearing 684 by applying a preload to the intermediate portion 64B of the rotary shaft 64. Therefore, even if there is vibration of the rotating shaft 64 itself of the electric motor 6, fluctuations in the load applied to the ball nut 73, and fluctuations in the load acting on the worm gear 66, quiet tilt position adjustment is possible.

  Also, instead of the deep groove type radial ball bearing 684, if two angular type radial ball bearings are used in combination and preload is applied to the angular type radial ball bearing by a spacer, the balls and inner and outer rings of the angular type radial ball bearing are used. , The clearance between the inner ring of the angular radial ball bearing and the outer periphery of the intermediate portion 64B, and the clearance between the outer ring of the angular radial ball bearing and the housing 65 can be completely eliminated. This makes it possible to adjust the tilt position more silently.

  When it is necessary to adjust the tilt position of the steering wheel 3, when an unillustrated switch is operated, the electric motor 6 is rotationally driven in either the forward or reverse direction. Then, the rotation of the electric motor 6 is decelerated and transmitted from the worm gear 66 to the worm wheel 72, and the ball screw 71 integrated with the worm wheel 72 rotates, for example, so that the ball nut 73 moves along the ball screw 71 along the axis. Descend in the direction.

  Then, the ball 74 integral with the ball nut 73 is also lowered with respect to the column 4, and the ball 74 is fitted to the sleeve 75, so that the column 4 is tilted upward as shown in FIG. Further, when the ball 74 rises, the column 4 tilts downward. When the column 4 is tilted, the ball 74 is freely rotated and slid within the inner circumference 75A of the sleeve 75, so that the tilt movement of the column 4 is obstructed and is unnecessary between the ball 74 and the sleeve 75. There is no stress or friction.

* Second Embodiment Next, a second embodiment of the present invention will be described. FIG. 5: is a principal part schematic block diagram including a partial cross section which shows the electric telescopic type steering column apparatus of the 2nd Embodiment of this invention. FIG. 6 is a bottom view of FIG. In the following description, only structural parts different from the above embodiment will be described, and redundant description will be omitted. The second embodiment is an example in which the electric motor 6 described in the first embodiment is applied to a telescopic steering column device.

  An inner column 43 is fitted to the hollow cylindrical outer column 42 so as to be telescopically slidable in the axial direction (left-right direction in FIG. 5). A rectangular opening 45 is formed in the lower part of the outer column 42, and a sleeve 75 fixed to the inner column 43 protrudes outward through the opening 45. The opening 45 functions as a stopper when the outer periphery of the sleeve 75 abuts against the front end 45A and the rear end 45B of the opening 45 when adjusting the telescopic position, and also functions to prevent the inner column 43 from rotating in the rotational direction. Also plays.

  A steering shaft 2 is rotatably supported on the inner column 43, and a steering wheel 3 is mounted on the steering shaft 2 at the right end (rear side of the vehicle body). A front shaft support portion 44A and a rear shaft support portion 44B are integrally formed on the lower surface of the outer column 42 so as to protrude forward and backward with the opening 45 therebetween, and both front and rear ends of the ball screw 71 are connected via a rolling bearing (not shown). Are pivotally supported. Further, the electric motor 6 described in FIG. 7 is fixed to the side surface of the outer column 42.

  A worm gear 66 formed integrally with the rotating shaft 64 of the electric motor 6 is engaged with a worm wheel 72 fixed to the ball screw 71. The worm wheel 72 and the worm gear 66 constitute a speed reduction mechanism, and the rotation of the electric motor 6 is decelerated and transmitted to the ball screw 71.

  A ball nut 73 that converts the rotation of the ball screw 71 into a linear motion is screwed into the ball screw 71. Since the ball is interposed, there is no backlash between the ball screw 71 and the ball nut 73, so that the inner column 43 does not feel loose and the steering wheel 3 feels good. Further, since the feed resistance is small and the fluctuation of the feed resistance is small, it is possible to adjust the telescopic position smoothly.

  A ball 74 having a spherical protrusion on the upper side is integrally formed on the ball nut 73, and the outer periphery of the ball 74 is slidably fitted into the inner periphery 75A of the sleeve 75, so that a spherical joint is attached. It is composed.

  When it is necessary to adjust the telescopic position of the steering wheel 3, when the switch (not shown) is operated, the electric motor 6 is rotationally driven in either the forward or reverse direction. Then, the rotation of the electric motor 6 is decelerated and transmitted from the worm gear 66 to the worm wheel 72, and the ball screw 71 integrated with the worm wheel 72 rotates, for example, the ball nut 73 moves along the ball screw 71. Move to the left (front side of the car).

  Then, the ball 74 integral with the ball nut 73 also moves leftward, and the ball 74 is fitted to the sleeve 75, so that the inner column 43 telescopically moves leftward. Further, when the ball 74 moves in the right direction (rear side of the vehicle body), the inner column 43 moves telescopically in the right direction. When the inner column 43 moves telescopically, the ball 74 freely rotates and slides within the inner circumference 75A of the sleeve 75, so that the telescopic movement of the inner column 43 is hindered, or between the ball 74 and the sleeve 75, Unnecessary stress and friction are not generated.

  In the second embodiment described above, the rotating shaft 64 of the electric motor 6 is pivotally supported with a preload applied by a rolling bearing such as a deep groove radial ball bearing 684 or an angular radial ball bearing. The telescopic position can be quietly adjusted even if there is vibration of the rotary shaft 64 itself, fluctuations in the load applied to the ball nut 73, and fluctuations in the reaction force acting on the worm gear 66.

  In the above-described embodiment, an example is shown in which the present invention is applied to an electric steering column apparatus capable of tilt position adjustment or telescopic position adjustment. However, in the electric steering column apparatus capable of both tilt position adjustment and telescopic position adjustment, You may apply. Moreover, in the said embodiment, although the ball bearing is used as a rolling bearing, you may use a roller bearing. Furthermore, in the said embodiment, although the worm gear 66 which is an input shaft of a reduction mechanism is integrally shape | molded by the rotating shaft 64 of the electric motor 6, the rotating shaft 64 and the input shaft of a reduction mechanism are shape | molded separately, You may combine with connection means, such as a key and a serration.

  In the above-described embodiment, the ball screw 71 and the ball nut 73 with a ball interposed therebetween are used, but a combination of a screw and a nut without a ball may be used. Moreover, in the above-mentioned embodiment, although applied to the electric motor with a brush, you may apply to a brushless electric motor. Further, the speed reduction mechanism composed of the worm gear 66 and the worm wheel 72 according to the above-described embodiment changes the crossing angle between the rotating shaft 64 of the electric motor 6 and the ball screw 71, so that a spur gear, a helical gear, It can be replaced with a speed reduction mechanism such as a mackerel gear.

1 is an overall perspective view showing a state where an electric steering column device of the present invention is attached to a vehicle. It is a principal part schematic block diagram including the partial cross section which shows the electric tilt type steering column apparatus of the 1st Embodiment of this invention. It is AA sectional drawing of FIG. It is explanatory drawing which shows the tilt operation of 1st Embodiment. It is a principal part schematic block diagram including the partial cross section which shows the electric telescopic type steering column apparatus of the 2nd Embodiment of this invention. FIG. 6 is a bottom view of FIG. 5. It is sectional drawing of the electric motor of embodiment of this invention. It is sectional drawing of the electric motor used for the conventional electric steering column apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric steering column apparatus 101 Universal joint 102 Lower shaft 103 Universal joint 104 Steering gear 105 Tie rod 2 Steering shaft 3 Steering wheel 4 Column 41 Bracket 41A Upper shaft support part 41B Lower shaft support part 42 Outer column 43 Inner column 44A Front shaft support part 44B Rear Shaft support 45 Opening 45A Front end 45B Rear end 51 Lower body mounting bracket 511 Mounting section 512 Pivoting section 513 Pivot pin 52 Upper body mounting bracket 521 Mounting section 522 Column support section 522A Left end surface 523 Long hole 53 Car body 6 Electric motor 61 Motor case 611 Inner peripheral surface 62 Magnet 63 Armature 64 Rotating shaft 64A Rear end portion 64B Intermediate portion 64C Front end portion 65 Ujingu 66 worm gear 67 commutator 671 brush 681, 682, 683 sliding bearing 684 deep groove form radial ball bearing 71 Ball screw 72 worm wheel 73 the ball nut 74 ball 75 sleeve 75A inside peripheral

Claims (5)

A steering shaft with a steering wheel mounted on the rear side of the vehicle body,
A column capable of pivotally supporting the steering shaft and adjusting a tilt position with a tilt center axis as a fulcrum or a telescopic position adjustment along the center axis of the steering shaft,
Electric motor,
In the electric steering column apparatus provided with a speed reduction mechanism that decelerates the rotation of the rotating shaft of the electric motor and transmits the tilt motion or telescopic motion of the column,
The electric motor is
An electric steering column apparatus characterized in that at least one of the bearings supporting the rotating shaft is a rolling bearing. In the electric steering column apparatus according to claim 1,
The electric steering characterized in that the rotating shaft of the electric motor and the input shaft of the speed reduction mechanism are formed on the same axis, and at least one of the bearings supporting the rotating shaft and the input shaft is a rolling bearing. Column device. In the electric steering column apparatus according to any one of claims 1 and 2,
An electric steering column device characterized in that the rolling bearing is constituted by a deep groove ball bearing or an angular ball bearing. In the electric steering column device according to any one of claims 1 to 3,
An electric steering column apparatus, wherein the rotating shaft and the input shaft are integrally formed. In the electric steering column apparatus according to any one of claims 1 to 4,
A worm gear is formed on the input shaft, and a tilting motion or a telescopic motion is transmitted to the column via a worm wheel meshing with the worm gear.

Images