JP2012041034A - Electric power steering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a high degree of requirement of light-weight formation of an automobile in order to save energy and fulfill a requirement of providing a compact and light-weight, easy handling and easy assembling a steering column supporting device in an electric power steering apparatus.SOLUTION: A bracket for use in fixing a steering column to a vehicle body is applied as a separate member that comprises a lower bracket and an upper bracket, and further inhibiting segments 49 and 50 for use in inhibiting an oscillating range of the lower bracket that is attached to the steering column in such a way that it can be oscillated are arranged at a lower bracket 35 and a steering column housing 18.

Description

  The present invention relates to an electric power steering apparatus.

As a prior art, a device has been proposed in which a lower portion of a steering column is supported so as to be swingable about a tilt center axis (for example, Patent Document 1). In Patent Document 1, the steering column is supported by an upper fixing bracket and a lower fixing bracket fixed to the vehicle body. The lower bracket supports a lower column bracket fixed to the lower portion of the steering column so as to be swingable via a tilt center axis.
On the other hand, the upper fixing bracket supports the upper column bracket fixed to the upper part of the steering column so as to be slidable up and down during tilt adjustment. Further, the steering column position after tilt adjustment is locked by tightening the both side plates of the upper column bracket from the outside between the both side plates of the upper fixing bracket by operating the rotating lever.

JP 2004-136870 A

When assembling the tilt steering device as in Patent Document 1 to the vehicle, the steering column swings in the tilt direction, and the bracket is attached to the vehicle body while supporting the heavy steering column with the hand. There is a problem of being bad. In particular, in the case of the electric power steering apparatus, since the heavy electric motor is provided, the assembling property is further deteriorated.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a bracket in which a tilt steering device equipped with an electric power steering device is improved in ease of assembly to a vehicle body.

  In order to solve the above-described problem, the invention according to claim 1 is an electric power steering apparatus equipped with an electric motor in the vicinity of the steering shaft, and the steering shaft is rotatably supported, and the tilt support shaft is adjusted during tilt adjustment. A steering column that swings around and a fixed bracket that supports the steering column via a tilt support shaft. A connecting member that connects the upper and lower sides of the steering shaft, a first restricting portion that can restrict the rotation direction of the steering column in the first rotating direction around the tilt support shaft to the side plate, and the first rotating direction An electric power steering apparatus comprising a second restricting portion capable of restricting in the opposite second rotational direction It is the gist that there.

  That is, when the electric power steering apparatus is attached to the vehicle body, the first and second restricting portions can restrict relative rotation of the first fixed bracket and the steering column at an excessively large angle in the tilt direction. Assembling to the vehicle body becomes easy.

  According to a second aspect of the present invention, one of the first restricting portion and the second restricting portion is an abutting portion that can abut on a protrusion extending from the steering column from above, and the other is a steering column. The gist of the invention is that it is a contact portion that can contact the worm housing from the side surface in the column axial direction.

  That is, the first restricting portion and the second restricting portion are provided on one side plate, the structure of the bracket and the structure of the restricting portion of the column are simple, and the restricting directions are the attachment direction to the vehicle and the column shaft. Because it is oriented, the assembly of the bracket to the column can be improved.

  As described above, according to the present invention, even in the case of a tilt steering device equipped with an electric power steering device, the swing range of the steering column can be restricted, so that the assembling property to the vehicle body can be improved and the assembling workability is remarkably improved. To improve.

Schematic perspective view of electric power steering device Partially cutaway side view of an electric power steering device Partial side view of electric power steering device Schematic view of the electric power steering device as seen from below in the axial direction of the steering shaft 4 is a schematic diagram of another embodiment of FIG.

  A preferred embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic perspective view of an electric power steering apparatus according to an embodiment of the present invention. As shown in FIG. 1, an electric power steering apparatus 1 includes a universal shaft 6 connected to a steering shaft 3 connected to a steering member 2 such as a steering wheel, and an intermediate shaft 5 connected to the steering shaft 3 via a universal joint 4. And a rack shaft as a steered wheel having a rack 8a that meshes with the pinion 7a provided in the vicinity of the end of the pinion shaft 7. The rack and pinion mechanism including the pinion shaft 7 and the rack shaft 8 constitutes a turning mechanism A1. The rack shaft 8 is supported by a housing (not shown) fixed to the vehicle body so as to be movable in the vehicle width direction W1. Each end of the rack shaft 8 is connected to a corresponding steered wheel 10 via a corresponding tie rod 9 and a corresponding knuckle arm (not shown).

  A steering mechanism A1 is configured by a rack and pinion mechanism including the pinion shaft 7 and the rack shaft 8. The rack shaft 8 is supported by a housing (not shown) fixed to the vehicle body so as to be movable in the vehicle width direction W1. Each end of the rack shaft 8 is connected to a corresponding steered wheel 10 via a corresponding tie rod 9 and a corresponding knuckle arm (not shown).

The steering shaft 3 includes a first shaft 11 and a second shaft 12 that are connected to each other so as to be able to transmit torque and to be relatively moved in the axial direction X1 via a torsion bar (not shown). The steering shaft 3 is rotatably supported via a bearing (not shown) by a steering column 15 fixed to a lower fixing bracket 13 as a first bracket and an upper fixing bracket 14 as a second bracket. The lower fixing bracket 13 as the first bracket and the upper fixing bracket 14 as the second bracket are made of sheet metal, for example, and are fixed to the vehicle body.
The steering column 15 includes an upper tube 16 and a lower tube 17 that are fitted so as to be relatively movable in the axial direction, and a housing 18 that is connected to a lower end in the axial direction of the lower tube 17. Above the housing 18, an electric motor 19 for assisting steering and a controller 20 for controlling the operation of the electric motor 19 are arranged side by side in the vehicle width direction W1.

As shown in FIG. 2, which is a partially cutaway side view of the electric power steering apparatus 1, a reduction mechanism 21 that reduces the power of the electric motor 19 and transmits it to the second shaft 12 is accommodated in the housing 18. . The speed reduction mechanism 21 includes a driving gear (not shown) provided so as to be able to rotate together with the rotating shaft of the electric motor 19, and a driven gear 22 that meshes with the driving gear and is connected to the second shaft 12 so as to be able to rotate together. Have. For example, a worm can be used as the drive gear, and a worm wheel can be used as the driven gear 22. As shown in FIG. 1, the drive gear is housed in a drive gear housing portion 24 provided in the housing 18. As shown in FIG. 2, the driven gear is accommodated in a driven gear accommodating portion 23 provided in the housing 18, and the housing 18 accommodates a torque sensor 25 that detects a steering torque applied to the steering shaft 3. Has been.
The controller 20 houses a power board and a control board (not shown) in the case 26. The controller 20 controls the drive of the electric motor 19 based on the torque detection result from the torque sensor and the vehicle speed detection result from the vehicle speed sensor (not shown).

Referring to FIG. 1, the electric power steering apparatus 1 is configured as a tilt steering apparatus having a tilt adjustment function. Specifically, the lower fixed bracket 13 as the first fixed bracket fixed to the vehicle body supports the steering column 15 so as to be swingable around the tilt support shaft 27 via a tilt support shaft 27 including a pivot shaft. is doing.
The electric motor 19 and the controller 20 are arranged to stand upward in a direction orthogonal to both the axial direction X1 of the steering shaft 3 and the central axis 27a of the tilt support shaft 27.

  On the other hand, the upper fixing bracket 14 as a second fixing bracket fixed to the vehicle body moves the downward groove-shaped upper column bracket 28 fixed to the steering column 15 up and down (specifically, tilt support). The shaft 27 is supported so as to be slidable in the rotation direction around the shaft 27.

  The upper fixing bracket 14 has an upper plate 142 having a pair of left and right mounting seats 141 and a pair of side plates 29 included in a downward groove shape fixed to the lower surface of the upper plate 142. Each mounting seat 141 is provided with a mounting groove 143 that opens toward the rear of the vehicle. A fixing bolt (not shown) to the vehicle body is inserted through the mounting groove 143 upward. Although not shown, the fixing bolt is fixed to the vehicle body through a so-called capsule for holding the mounting seat 141 on the vehicle body with a predetermined holding force. With the function of the capsule, the fixing bolt can be detached from the mounting groove 143 when absorbing the shock.

  In addition, a tightening mechanism 31 for tightening and fixing the pair of side plates 30 of the upper column bracket 28 is provided between the pair of side plates 29 of the upper fixing bracket 14 as the second fixing bracket after the tilt adjustment. The tightening mechanism 31 tightens and releases the tightening by rotating the operation lever 33 around the tightening shaft 32 penetrating the both side plates 29 of the upper fixing bracket 14 and the both side plates 30 of the upper column bracket 28.

  Referring to FIG. 3, which is a perspective view of the electric power steering apparatus 1 viewed from an angle different from FIG. 1, and FIG. 4, which is a schematic view viewed from below the axial direction X 1 of the steering shaft 3, as a first fixed bracket The lower fixing bracket 13 sandwiches the steering shaft 3, more specifically, a pair of side plates 34 and 35 facing each other with the housing 18 of the steering column 15 sandwiched in the vehicle width direction W1, and the pair of side plates 34, And a connecting member 36 that connects between the upper and lower portions of the second shaft 12 of the steering shaft 3 (in this embodiment, the upper portion of the second shaft 12 of the steering shaft 3 as shown in FIG. 1). Yes.

  Attachment plates 37 and 38 to the vehicle body are extended outward from the upper ends of the pair of side plates 34 and 35, respectively. As shown in FIGS. 3 and 4, mounting grooves 39 and 40 are formed in the mounting plates 37 and 38. The lower fixing bracket 13 is fixed to the vehicle body by fixing bolts (not shown) passing through the mounting grooves 39 and 40.

  As shown in FIGS. 1 and 3, the tilt support shaft 27 is inserted into the lower portions 41 and 42 of the side plates 34 and 35. Although not shown, insertion holes for inserting the tilt support shafts 27 are formed in the lower portions 41 and 42 of the side plates 34 and 35, and the tilt support shafts 27 inserted through the insertion holes are as shown in FIG. Is inserted into an insertion hole (not shown) of a tilt support shaft connecting portion 43 provided in the housing 18. Accordingly, the housing 18 is supported by the lower fixing bracket 13 so as to be swingable around the tilt support shaft 27.

  As shown in FIG. 4, one side plate 34 is close to the side portion 19 a of the electric motor 19, and the other side plate 35 is along the case 26 of the controller 20. Regarding the vehicle width direction W1, the distance L1 between one side plate 34 and the central axis C1 of the steering shaft 3 is the distance L1 between the other side plate 34 and the central axis C1 of the steering shaft 3, and the other side plate 35 and the steering shaft 3 are steered. The distance from the center axis C1 of the shaft 3 is longer than the distance L2. (L1> L2).

  The electric motor 19 is fixed to a pedestal 44 formed on the top of the housing 18. On the other hand, the case 26 of the controller 20 is fixed to the inner side surface 35 a of the other side plate 35, and a gap 45 is formed between the case 26 and the pedestal 44.

  On the other hand, at the lower end of the side plate 35 to which the controller 20 is fixed, a contact portion 49 as a first restricting portion that can be contacted from above is provided on a protrusion 48 extending from the driven gear accommodating portion 24 of the housing 18. It has been. When the electric power steering apparatus 1 is assembled to the vehicle, the abutting portion 49 as the first restricting portion abuts on the protrusion 48 from above, so that the second rotating direction Z2 (the opposite direction to the first rotating direction Z1) The rotation of the steering column 15 around the tilt support shaft 27 with respect to (see FIG. 3) is restricted.

  A contact portion 50 as a second restricting portion that can be contacted from a side surface of the housing 18 from a direction parallel to the column shaft is provided. When the electric power steering device 1 is assembled to the vehicle, the contact portion 50 as the second restricting portion contacts the second rotation direction Z2 (see FIG. 3) opposite to the first rotation direction Z1. The rotation of the steering column 15 around the tilt support shaft 27 is restricted.

  When the electric power steering apparatus 1 is assembled to the vehicle, the contact portion 49 as the first restricting portion and the contact portion 50 as the second restricting portion restrict the swing range of the steering column 15 around the tilt support shaft 27. Since the electric power steering apparatus 1 is assembled to the vehicle after the electric power steering apparatus 1 is assembled to the vehicle, the range is larger than the swinging range of the steering column 15 by tilt adjustment. However, it does not disturb the tilt adjustment.

  The protrusion 48 may be replaced with a protrusion 70 having a shape as shown in FIG. A thinning 70a is provided at the base of the projection 70 to enable elastic deformation. In order to absorb the impact force at the time of collision described below, the width and thickness are selected to be appropriate sizes for elastic deformation. With such a configuration, when an impact force at the time of a collision is applied, a rotational force is applied to lift the steering column around the tilt support shaft 27, and the tip portion 70a of the projection 70 of the gear housing 23 is connected to the bracket side plate. When the projection 70 is bent at the elastic deformation portion 70a, the impact force is absorbed.

  In the present embodiment, the assembly work to the vehicle is facilitated. Specifically, the assembly work of the electric power steering apparatus 1 is as follows. That is, the upper end of the intermediate shaft 5 whose lower end is connected to the pinion shaft 7 of the steering mechanism A1 is positioned in the vehicle compartment through the dash panel (not shown). Next, the steering column 15 supporting the steering shaft 3 is assembled to the vehicle body, and then the lower end of the steering shaft 3 is inserted into the universal joint 4 at the upper end of the intermediate shaft 5 and fixed by fastening with a bolt (not shown). To do.

  When the steering column 15 is assembled to the vehicle body with the bolts temporarily fixed to the vehicle body, first, the lower fixing bracket 13 is assembled to the vehicle body using bolts in the mounting grooves 39 and 40 of the lower fixing bracket 13. At the time of this assembly, with the steering column 15 supported by hand, the swing range of the lower fixed bracket 13 around the tilt support shaft 27 is the contact portion 49 as the first restricting portion and the second restricting portion. Therefore, the lower fixing bracket 13 can be easily aligned and attached to the attachment portion on the vehicle body side, and the assemblability is good.

  In a state where such a lower fixing bracket 13 is assembled to the vehicle body, the contact portion 49 as the first restricting portion contacts the side surface of the housing 18 of the steering column 15, so that the load on the steering column is increased. Since it can be supported, the assembly workability when the fixing bracket 14 is next assembled to the vehicle body is remarkably improved.

  Moreover, since the lower fixing bracket 13 as the first fixing bracket has a simple structure in which the pair of side plates 34 and 35 are connected by the connecting member 36, it is possible to contribute to weight reduction of the electric power steering apparatus.

  The present invention is not limited to the above-described embodiment. For example, the connecting member 36 of the lower fixing bracket 13 may connect the pair of side plates 34 and 35 across the lower side of the steering shaft 3. Further, a connecting member that crosses the upper side of the steering shaft 3 and a connecting member that crosses the lower side of the steering shaft may be provided. In addition, various modifications can be made within the scope of the claims of the present invention.

DESCRIPTION OF SYMBOLS 1 Electric power steering device, 2 Steering member, 3 Steering shaft, 5 Intermediate shaft, 7 Pinion shaft, 8 Rack shaft, 10 Steering wheel, 11 1st shaft, 12 2nd shaft, 13 Lower fixed bracket (1st fixed bracket) , 14 Upper fixing bracket (second fixing bracket), 15 Steering column, 16 Upper tube, 17 Lower tube, 18 Housing, 19 Electric motor, 20 Controller, 21 Reduction mechanism, 26 (Controller) case, 27 Tilt support shaft, 27a Center axis (of tilt support shaft), 28 Upper column bracket, 34, 35 Side plate, 34a, 35a Inner side surface, 36 Connecting member, 44 Base, 48 Protrusion, 49 Contact part (first regulating part), 50 Contact Part (second regulating part), A1 steering mechanism, C The central axis (the steering shaft), W1 vehicle width direction, (the steering shaft) X1 axis direction, (the tilt around the support shaft) Z1 first rotational direction, Z2 second rotational direction (the tilt support axis)

Claims (2)

In an electric power steering apparatus equipped with an electric motor in the vicinity of a steering shaft, a steering column that rotatably supports the steering shaft and swings around a tilt support shaft during tilt adjustment, and a steering column via the tilt support shaft The fixed bracket includes a pair of side plates facing each other across the steering shaft in the vehicle width direction, a connecting member that connects the pair of side plates across the upper or lower portion of the steering shaft, and a side plate. A first restricting portion capable of restricting the rotation direction of the steering column in the first rotation direction around the tilt support shaft and a second restricting portion capable of restricting in the second rotation direction opposite to the first rotation direction are provided. An electric power steering device. One of the first restricting portion and the second restricting portion is an abutting portion capable of abutting on a protrusion extending from the steering column from above, and the other is an abutting portion capable of abutting on the housing of the steering column from the side. The electric power steering apparatus according to claim 1, which is a contact portion.