JP2014015106A - Electric power steering apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric power steering apparatus that is easily assembled to a vehicle body by preventing excessive rotation of a lower bracket in a state before being assembled to the vehicle body and has high support rigidity with respect to a steering column after being assembled to the vehicle body.SOLUTION: An engagement portion of a housing with a tilt pivot shaft is provided behind a rotation axis of an electric motor, a pair of projected portions projecting forward with predetermined spacing in a vertical direction is formed at a front side end of at least one of side plates of a lower bracket, a protrusion projecting more outward in a vehicle width direction than the pair of projected portions is formed between the projected portions in the housing, and the pair of projected portions and the protrusion constitute a rotation regulation mechanism for regulating rotation of the lower bracket with respect to a steering column with the tilt pivot shaft used as a rotation center in a state where an electric power steering apparatus has not yet been assembled to a vehicle body to a predetermined range.

Description

  The present invention relates to an electric power steering device, and more particularly to an electric power steering device capable of adjusting a tilt position.

  There is an electric power steering device including a tilt position adjusting mechanism for adjusting the vertical height of a steering wheel in accordance with the physique and driving posture of a driver. The tilt position is adjusted by rotating the steering column up and down around the tilt pivot. The tilt pivot is provided on a lower bracket that supports the steering column on the vehicle body at a front side portion of the steering column. After adjusting the tilt position, the steering column is clamped by the clamp mechanism, and the steering column is positioned at the tilt adjustment position. The clamp mechanism is provided in an upper bracket that supports the steering column on the vehicle body at a rear side portion of the steering column.

  As described above, since the upper bracket is provided with the clamp mechanism, the upper bracket prevents the upper bracket from rotating with respect to the steering column by clamping the steering column with the clamp mechanism when the electric power steering device is not attached to the vehicle body. can do. On the other hand, the lower bracket does not have a fixing mechanism for the steering column such as a clamp mechanism. Therefore, in a state before the vehicle body is attached, the lower bracket easily rotates around the tilt pivot, and rotates when an external force is applied to the lower bracket. Thus, when such an electric power steering device is attached to the vehicle body, there is a device provided with a rotation restricting portion so that the lower bracket does not rotate excessively by an external force (see, for example, Patent Documents 1 and 2).

  In Patent Document 1, a rotation restricting portion is provided on a lower bracket and a housing in which a speed reduction mechanism is accommodated. Moreover, in patent document 2, rotation to the one side of a lower bracket is controlled because the lower surface of one side plate and the 1st projection part formed in the housing contact among the pair of side plates of a lower bracket. The L-shaped restricting portion formed on the other side plate and the second protrusion formed on the housing come into contact with each other to restrict the rotation of the lower bracket to the other side.

WO2005 / 030557 JP 2011-178268 A

  A column-type electric power steering device is heavy because it includes an electric motor, a speed reduction mechanism, an electronic control unit ECU (ECU) for controlling the electric motor, and the like on the steering column. Therefore, assembling the column type electric power steering device to the vehicle body is an operation while supporting a large weight, and if the lower bracket is rotated at this time, the assembling property is deteriorated. Further, since the weight is large, the bracket for supporting the electric power steering device on the vehicle body is required to have high support rigidity with respect to the steering column.

  The present invention has been made in view of such a situation, and in the state before the electric power steering apparatus is assembled to the vehicle body, the lower bracket is prevented from being excessively rotated to facilitate the assembly to the vehicle body. It is an object of the present invention to provide an electric power steering device having high support rigidity with respect to a steering column.

  The above problem is solved by the following means. That is, the present invention provides a steering shaft to which a steering wheel is attached at a rear end, a steering column that rotatably supports the steering shaft, and a steering column that rotates about the tilt pivot shaft. A tilt adjusting mechanism capable of positioning the steering column at a desired tilt adjusting position; an electric motor for generating an auxiliary steering torque; and a worm connected to a rotating shaft of the electric motor, and a worm wheel meshing with the worm. And a pair of housings that are fixed to the vehicle body, are opposed to each other in the vehicle width direction, and support the tilt pivot shaft. And a lower bracket with side plates A housing is provided with an engaging portion with the tilt pivot shaft, and the steering column is pivotally engaged with the tilt pivot shaft through the engaging portion so that the steering column can move the tilt pivot shaft. In the electric power steering device that is rotatable as a rotation center, the engagement portion of the housing is provided in a portion of the housing on the rear side of the rotation shaft of the electric motor, and at least one of the lower brackets A pair of convex portions projecting forward at a predetermined interval in the vertical direction are formed at the front end of the side plate of the side plate, and the housing has a vehicle more than the convex portion between the pair of convex portions. A protruding portion protruding outward in the width direction is formed, and the pair of protruding portions and the protruding portion are in a state before the vehicle body is assembled to the electric power steering device. An electric power steering apparatus characterized by constituting the turn restricting mechanism for restricting a predetermined range a rotation with respect to the steering column to rotate about the tilt pivot shaft of definitive the lower bracket.

  In a preferred aspect of the present invention, the rotation restricting mechanism is configured such that when the lower bracket rotates to one side with the tilt pivot shaft as a rotation center, one of the pair of convex portions contacts the protruding portion. In the electric power steering apparatus, it is preferable that the other of the pair of convex portions comes into contact with the protruding portion when rotated to the other side.

  Moreover, the preferable aspect of this invention is an electric power steering apparatus with which it is preferable that the said pair of side plate of the said lower bracket is connected with the connection member extended in a vehicle width direction.

  Moreover, the preferable aspect of this invention is an electric power steering apparatus with which the said connection part has connected the back ends of a pair of said side plate.

  In a preferred aspect of the present invention, the pair of convex portions of the lower bracket is preferably located in front of the tilt pivot shaft.

  According to the present invention, before the electric power steering apparatus is assembled to the vehicle body, the lower bracket is prevented from being excessively rotated to facilitate the assembly to the vehicle body, and after being assembled to the vehicle body, the steering column is supported. An electric power steering apparatus having high rigidity can be provided.

It is a perspective view which shows the state which attached the electric power steering device which concerns on embodiment of this invention to the vehicle body. It is a perspective view from the back side slanting upper part of the electric power steering device concerning an embodiment. It is a perspective view from the back side right diagonal upper part of the electric power steering device concerning an embodiment. 1 is a right side view of an electric power steering apparatus according to an embodiment. It is a top view of the electric power steering device concerning an embodiment. 1 is a left side view of an electric power steering apparatus according to an embodiment. It is sectional drawing of the AA line of FIG. It is the perspective view which looked at the lower bracket from the back side. It is the perspective view which looked at the lower bracket from the front side. It is a typical partial side view which shows the assembly method of a lower bracket.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, directions related to the electric power steering apparatus in the present specification will be defined. In this specification, the direction related to the electric power steering device is the same as the front-rear, left-right, and up-down directions of the vehicle body attached to the vehicle body unless otherwise specified. The left-right direction is also called the vehicle width direction. Moreover, the definition of the direction in each figure shown below refers to the state where the paper surface is viewed in a state where the reference numerals in each figure can be read in a normal direction.

  In FIG. 1, the diagonally lower left side of the page is the front side, the diagonally upper right side of the page is the rear side, the diagonally upper left side of the page is the right side, and the diagonally lower right side of the page is the left side. In FIG. 2, the diagonally upward left direction is the front side, the diagonally downward right direction is the rear side, the diagonally upward right direction is the right side, and the diagonally downward left direction is the left side. 3 and 8, the upper right side of the drawing is the front side, the lower left side of the drawing is the rear side, the lower right side of the drawing is the right side, and the upper left side of the drawing is the left side. In FIG. 4, the right direction on the paper surface is the front side, the left direction on the paper surface is the rear side, the front side of the paper surface is the right side, and the back direction on the paper surface is the left side. In FIG. 5, the left direction on the paper surface is the front side, the right direction on the paper surface is the rear side, the upward direction on the paper surface is the right side, and the downward direction on the paper surface is the left side. 6 and 10, the left direction on the paper surface is the front side, the right direction on the paper surface is the rear side, the back direction on the paper surface is the right side, and the front direction on the paper surface is the left side. In FIG. 7, the back direction of the paper surface is the front side, the front side of the paper surface is the rear side, the right direction of the paper surface is the right side, and the left direction of the paper surface is the left side. In FIG. 9, the diagonally lower left side of the plane of the drawing is the front side, the diagonally upper side of the plane of the page is the rear side, the diagonally upper left side of the plane of the page is the right side, and the diagonally lower side of the plane of the page is the left side.

  FIG. 1 is a perspective view showing a state where an electric power steering apparatus according to an embodiment of the present invention is attached to a vehicle body. As shown in FIG. 1, an electric power steering device 1 according to an embodiment of the present invention is a column assist type power steering device. The electric power steering device 1 applies the steering assist force of the electric power assist device 22 attached to the steering column 10 to the output shaft 5 in order to reduce the operation force of the steering wheel 3, and the rack via the intermediate shaft 6. This is a power steering device of a type in which a rack of a pinion type steering gear assembly 7 is reciprocated and a steered wheel is steered via a tie rod 8.

  FIG. 2 is a perspective view of the electric power steering apparatus according to the present embodiment as viewed obliquely from the upper left of the rear side. FIG. 3 is a perspective view of the electric power steering apparatus according to the present embodiment as viewed from diagonally upward on the rear side. FIG. 4 is a right side view of the electric power steering apparatus according to the present embodiment. FIG. 5 is a plan view of the electric power steering apparatus according to the present embodiment. FIG. 6 is a left side view of the electric power steering apparatus according to the present embodiment. 7 is a cross-sectional view taken along line AA in FIG.

  As shown in FIGS. 2 to 7, the electric power steering apparatus 1 according to the present embodiment includes an upper steering shaft 2, a steering column 10 that supports the upper steering shaft 2, a distance bracket 16 attached to the steering column 10, a distance The vehicle body mounting bracket 18, the lower bracket 20, the power assist device 22, and the like disposed above the bracket 16 are configured. The steering column 10 includes an upper column 12 that is an outer column and a lower column 14 that is an inner column. The upper column 12 and the lower column 14 are steel pipes or light alloy die-cast molded products, and are each formed in a cylindrical shape.

  As shown in FIGS. 4 to 6, the inner peripheral surface of the upper column 12 is fitted on the outer peripheral surface of the rear side portion of the lower column 14 so as to be slidable in the axial direction. A lower steering shaft (not shown) is rotatably supported on the inner peripheral side of the lower column 14 via a bearing (not shown). The upper steering shaft 2 is rotatably supported on the inner peripheral side of the upper column 12 via a bearing (not shown). The upper steering shaft 2 and the lower steering shaft are fitted so as to be relatively movable in the axial direction. A switch bracket 24 for attaching a combination switch (not shown) is attached to the rear side end of the upper column 12. A steering wheel 3 is fixed to the rear end portion of the upper steering shaft 2 as shown in FIG.

  The distance bracket 16 includes a pair of left and right side plates 26 and 26 facing in the vehicle width direction, and a connecting portion 28 that connects the upper ends of the pair of side plates 26 and 26. The lower ends of the side plates 26 are fixed to the left and right side portions of the upper outer peripheral surface of the upper column 12 with the central axis of the upper column 12 in between. Thereby, the distance bracket 16 is fixed to the upper column 12.

  The vehicle body mounting bracket 18 is attached to a pair of left and right side plates 30, 30 facing in the vehicle width direction, a flat plate portion 32 connecting the upper ends of the pair of side plates 30, 30, and an upper surface of the flat plate portion 32. And an upper plate 36 having a wider width in the left-right direction. The cross section of the pair of side plates 30 and 30 and the flat plate portion 32 is substantially U-shaped with the lower side opened. The pair of side plates 30 and 30 are disposed in contact with the outer surfaces of the pair of side plates 26 and 26 of the distance bracket 16, respectively. The flat plate portion 32 and the upper plate 36 are disposed above the distance bracket 16. As shown in FIG. 5, vehicle body attachment portions 38 and 38 are formed at the left and right ends of the upper plate 36, respectively. The vehicle body mounting bracket 18 is fixed to the vehicle body by bolts (not shown) via detachment capsules 40, 40 attached to the vehicle body mounting portions 38, 38. Bolt holes 42, 42 of the release capsules 40, 40 are long holes in the front-rear direction. By making the bolt holes 42, 42 into long holes, misalignment of the vehicle body attachment portions 38, 38 can be absorbed. At the time of the secondary collision, the vehicle body mounting bracket 18 moves away from the vehicle body while collapsing the capsules 40, 40, and absorbs the impact energy of the secondary collision.

  Referring to FIG. 3, the left and right side plates 26, 26 of the distance bracket 16 are slidable with respect to the left and right side plates 30, 30 of the vehicle body mounting bracket 18. The left and right side plates 30, 30 of the vehicle body mounting bracket 18 are formed with tilt adjusting elongated holes 44, 44 extending in the vertical direction. One round bar-shaped fastening bolt 46 is inserted through the left and right tilt adjusting long holes 44, 44 in the vehicle width direction. The fastening bolt 46 also penetrates the left and right side plates 26, 26 of the distance bracket 16 disposed inside the left and right side plates 30, 30 of the vehicle body mounting bracket 18. With such a configuration, the left and right side plates 26 and 26 of the distance bracket 16 are sandwiched by the left and right side plates 30 and 30 of the vehicle body mounting bracket 18 so as to be tilted and slidable while being guided by the long holes 44 and 44. .

  An operation lever 48 is attached to one end of the tightening bolt 46 (see FIG. 2). When the operation lever 48 is turned to one side, a cam lock mechanism (not shown) is operated, and the left and right side plates 30 of the vehicle body mounting bracket 18 are tightened in a direction approaching each other. As a result, the left and right side plates 26 and 26 of the distance bracket 16 are strongly tightened to the left and right side plates 30 and 30 of the vehicle body mounting bracket 18. By this tightening, the upper column 12 can be positioned at a desired tilt adjustment position. When the operation lever 48 is turned to the other side, the cam lock mechanism is loosened and the tightening of the left and right side plates 30, 30 of the vehicle body mounting bracket 18 is released. As a result, the tightening of the distance bracket 16 by the vehicle body mounting bracket 18 is released, and the tilt adjustment of the upper column 12 becomes possible.

  Although the electric power steering apparatus 1 according to the present embodiment is capable of tilt adjustment, an electric power steering apparatus capable of adjusting the telescopic position of the steering wheel in addition to the tilt adjustment may be used.

  An aluminum housing 50 is connected to the front end of the lower column 14. The housing 50 is assembled with a power assist device 22 that is a steering assist portion for applying an assist torque to the output shaft 5 (see FIG. 1). The power assist device 22 includes an electric motor 52, a worm 56 (see FIG. 6) connected to a rotating shaft 54 (see FIG. 6) of the electric motor 52, and a worm wheel 58 (see FIG. 4) meshing with the worm 56. And an electronic control unit ECU (Electric Control Unit: hereinafter referred to as ECU) 60 for controlling the electric motor 52, and a torque sensor (not shown). The electric motor 52 and the ECU 60 are arranged above the housing 50 in the vehicle width direction. The worm wheel 58 is stored in the storage portion 62 of the housing 50, and the worm 56 is stored in the storage portion 64 of the housing 50. The direction and magnitude of torque applied from the steering wheel 3 to the upper steering shaft 2 is detected by a torque sensor (not shown). In accordance with the detected value of the torque sensor, the electric motor 52 is driven to generate auxiliary torque with a predetermined magnitude in a predetermined direction via a speed reduction mechanism including a worm 56 and a worm wheel 58, and the output shaft 5 A steering assist torque is applied.

  Here, the column type electric power steering apparatus 1 is heavy because it includes the electric motor 52, the speed reduction mechanism, the ECU 60, and the like on the steering column. Therefore, the vehicle body mounting bracket 18 and the lower bracket 20 for supporting the electric power steering device 1 on the vehicle body are required to have high support rigidity with respect to the steering column 10. Specifically, the lower bracket 20 is required to improve the rigidity of the lower bracket 20 itself and the position of the lower bracket 20 relative to the steering column 10, that is, the position of the tilt pivot. The configuration and position of the lower bracket 20 will be described below.

  FIG. 8 is a perspective view of the lower bracket 20 as viewed from the rear side. FIG. 9 is a perspective view of the lower bracket 20 as viewed from the front side.

  As shown in FIGS. 8 and 9, the lower bracket 20 includes a pair of left and right side plates 66 and 66 that face each other in the vehicle width direction, and a reinforcing bridge 68 that connects the pair of side plates 66 and 66 in the vehicle width direction. ing. The pair of side plates 66, 66 are arranged on the outer side in the vehicle width direction of the housing 50, as shown in FIGS. 2 to 7. That is, they are arranged on the left and right sides in the vehicle width direction with the housing 50 therebetween. The electric motor 52 and the ECU 60 are disposed between the pair of side plates 66 and 66. The side plates 66 and 66 are provided with through holes 72 and 72 in the vehicle width direction. The through holes 72 and 72 are coaxial. A tilt pivot shaft 70 that is a rotation center axis of tilt adjustment is inserted into the through holes 72 and 72. That is, the tilt pivot shaft 70 is supported by the pair of side plates 66 and 66. Car body attachment parts 74 and 74 for attaching and fixing the lower bracket 20 to the vehicle body are formed at the upper ends of the side plates 66 and 66, respectively. The vehicle body attachment portions 74, 74 are formed to extend from the upper ends of the side plates 66, 66 outward in the vehicle width direction, and are formed with bolt holes 76, 76 through which bolts (not shown) for fixing are inserted from below. . Bolt holes 76 and 76 are long holes in the front-rear direction. By making the bolt holes 76 and 76 long holes, misalignment of the vehicle body mounting portions 74 and 74 can be absorbed.

  The reinforcing bridge 68 connects the upper portions of the rear side end portions of the side plates 66 and 66, and is arranged on the rear side of the electric motor 52 and the ECU 60 arranged in the housing 50 in the assembled state. In addition, the reinforcing bridge 68 is located on the rear side of the tilt pivot shaft 70 in the assembled state, as shown in FIGS. The reinforcing bridge 68 connects the pair of side plates 66 and 66 to increase the rigidity of the lower bracket 20 itself. Thus, by increasing the rigidity of the lower bracket 20 itself, the support rigidity of the lower bracket 20 with respect to the steering column 10 can be increased. When the rigidity of the lower bracket 20 itself is increased, the lower bracket 20 becomes difficult to be deformed at the time of a secondary collision, and the impact energy is absorbed smoothly.

  As shown in FIG. 7, the housing 50 is formed with a through hole 78 extending in the vehicle width direction. The through hole 78 is provided in the upper part of the portion of the housing 50 on the rear side of the rotating shaft 54 of the electric motor 52. A metal sleeve 80 is disposed inside the through hole 78. A tilt pivot shaft 70 is inserted into the through hole 78 via a sleeve 80. The tilt pivot shaft 70 is a single shaft member, and penetrates the through hole 78 in the vehicle width direction. The tilt pivot shaft 70 is fixed to the pair of side plates 66 and 66 of the lower bracket 20 by tightening one end portion with a nut 82. The peripheral portions of the openings on both sides of the through-hole 78 are formed in a planar shape and serve as a rotating seat surface of the lower bracket 20. As described above, the through hole 78 is provided at a position between the rotating shaft 54 of the electric motor 52 and the vehicle body mounting bracket 18 as shown in FIGS. 6 and 7.

  Resin spacers 86 and 86 are press-fitted into openings on both sides of the through-hole 78. The spacer 86 is made of a material having high strength and low sliding characteristics such as polyacetal (POM). The spacer 86 includes a cylindrical portion 88 and a flange portion 90 formed at one end of the cylindrical portion 88. Cylindrical portions 88 and 88 are press-fitted into both openings of the through hole 78, and both ends of the sleeve 80 are supported by the cylindrical portions 88 and 88 of the spacers 86 and 86, thereby preventing the sleeve 80 from rattling. The flange portions 90, 90 are interposed between the opening peripheral portion of the through hole 78 and the side plates 66, 66 of the lower bracket 20 to reduce friction on the sliding surface with the lower bracket 20.

  The housing 50 is rotatably supported by the lower bracket 20 with the tilt pivot shaft 70 as a rotation center. Thus, the lower column 14 connected to the housing 50 is supported on the vehicle body by the lower bracket 20 via the housing 50 and is rotatable about the tilt pivot shaft 70 as a rotation center.

  As described above, the tilt pivot shaft 70 is disposed in the through hole 78 provided in the upper portion of the housing 50 on the rear side of the rotating shaft 54 of the electric motor 52. That is, the tilt pivot shaft 70 is located on the rear side of the central cross section in the axial direction of the worm wheel 58 accommodated in the storage portion 62 of the housing 50. The axial central cross section of the worm wheel 58 is specifically a cut surface when the worm wheel 58 is cut in a direction perpendicular to the axial direction at the axial center. In other words, the tilt pivot shaft 70 is disposed between the rotating shaft 54 of the electric motor 52 and the upper body mounting bracket 18. By providing the tilt pivot shaft 70 at this position, many parts of heavy members such as the electric motor 52, the speed reduction mechanism, and the ECU 60 are positioned on the front side of the tilt pivot shaft 70. If it does so, the weight of the back side rather than the tilt pivot shaft 70 among the weights of the electric power steering device 1 becomes relatively small.

  When the tilt pivot shaft 70 is on the front side of the electric motor 52 as in the prior art, almost all of the weight of the electric power steering device 1 is on the rear side of the tilt pivot shaft 70, and the upper-side vehicle body mounting bracket 18 needed to support a large weight. If the weight on the front side of the tilt pivot shaft 70 is increased by providing the tilt pivot shaft 70 as in this embodiment, the weight on the rear side of the tilt pivot shaft 70 is reduced, and the upper-side vehicle body mounting bracket 18 is The supporting weight is small. As a result, even if the vehicle body mounting bracket 18 is equivalent to the conventional one, the support rigidity of the vehicle body mounting bracket 18 with respect to the steering column 10 can be relatively increased. When the support rigidity with respect to the steering column 10 is increased, it is possible to prevent vibration during idling and vibration during traveling from being transmitted to the steering column 10 and causing the steering column 10 to resonate with these vibrations. As a result, such vibration is not transmitted to the steering wheel 3, and the electric power steering apparatus 1 with a good steering feeling can be obtained.

  Further, when the support rigidity of the vehicle body mounting bracket 18 is increased as described above, the steering column 10 is not easily deformed at the time of a secondary collision. As a result, the steering column 10 smoothly moves in a collapsed manner, whereby the impact energy at the time of the secondary collision is absorbed smoothly. Furthermore, in this embodiment, since the rigidity of the lower bracket 20 itself is high as described above, the impact energy can be absorbed more smoothly. Here, the collapse movement means that the steering column moves while absorbing the impact energy while collapsing the energy absorbing member toward the front of the vehicle body at the time of the secondary collision.

  The electric power steering apparatus 1 according to the present embodiment is provided with a rotation restricting mechanism for the lower bracket 20 in a state before the electric power steering apparatus 1 is mounted on the vehicle body. That is, the lower bracket 20 is regulated so as not to rotate more than a predetermined range with respect to the steering column 10 around the tilt pivot shaft 70.

  As shown in FIGS. 8 and 9, the side plate 66 (left side in FIG. 8, right side in FIG. 9) on one side of the lower bracket 20 (left side in the vehicle width direction in the present embodiment) has an edge on the front side. A concave portion 91 that is recessed backward is formed in the central portion in the vertical direction. The inner side surfaces of the concave portions 91 facing in the vertical direction are spaced apart from each other by a predetermined distance. In other words, a pair of convex portions 92 and 92 projecting forward at a predetermined interval in the vertical direction are formed at the front edge portion of the side plate 66, and the concave portion 91 is interposed between the pair of convex portions 92 and 92. Is formed. The pair of convex portions 92, 92 are located in front of the tilt pivot shaft 70. A reinforcing rib 93 is formed on the front side edge of the left side plate 66 in the vehicle width direction from the upper end to the vicinity of the convex portion 92. A reinforcing rib 93 is also formed on the front side edge portion of the side plate 66 on the right side in the vehicle width direction (on the right side in FIG. 8 and on the left side in FIG. 9) from the upper end portion to the lower side edge portion. The left side plate 66 may also be formed with reinforcing ribs 93 on the front side edge portion from the upper end portion to the lower side edge portion.

  As shown in FIGS. 2 and 6, a protruding portion 94 that protrudes outward in the vehicle width direction is formed on the left side surface of the housing 50. The protrusion 94 is formed integrally with the aluminum housing 50. Here, the term “integrally formed” means that the housing 50 may be integrally formed by being molded simultaneously with other parts of the housing 50 as a part of the housing 50, or the housing 50. After the molding, the protruding portion 94 molded separately from the housing 50 may be integrally formed by welding, bolting, or fixing to the housing 50 by other methods.

  The protruding portion 94 is located between the surfaces of the pair of convex portions 92, 92 that face each other in the vertical direction in a state where the lower bracket 20 is assembled to the housing 50. That is, it is located inside the recess 91. In other words, the pair of convex portions 92 and 92 are arranged to face each other in the vertical direction with the protruding portion 94 therebetween. The protrusion 94 protrudes outward in the vehicle width direction from the protrusions 92, 92 of the lower bracket 20. The distance between the pair of convex portions 92 is provided so that the lower bracket 20 can rotate within a predetermined range. That is, the pair of convex portions 92 and 92 are in a state in which the convex portion 92 on one side is in contact with the protruding portion 94 and the convex portion 92 on the other side is in contact with the protruding portion 94 depending on the rotational position of the lower bracket 20. In this state, none of the protrusions 92 is in contact with the protrusion 94. The pair of convex portions 92 and 92 of the lower bracket 20 and the protruding portion 94 of the housing 50 constitute a rotation restricting mechanism for the lower bracket 20. The operation of the rotation restricting mechanism will be described below.

  In a state before the electric power steering device 1 is attached to the vehicle body, when the lower bracket 20 rotates to the one side with respect to the steering column 10 about the tilt pivot shaft 70, one convex portion 92 of the lower bracket 20 is formed. Contacting the protrusion 94 of the housing 50, the further rotation of the lower bracket 20 to one side is restricted. Further, when the lower bracket 20 rotates to the other side, the other convex portion 92 comes into contact with the protruding portion 94 of the housing 50, and further rotation of the lower bracket 20 to the other side is restricted. Thus, the rotation of the lower bracket 20 with respect to the steering column 10 is restricted to a predetermined range. As a result, when the electric power steering apparatus 1 is assembled to the vehicle body, the lower bracket 20 does not rotate greatly, and the lower bracket 20 can be easily attached to the vehicle body. The allowable rotation range of the lower bracket 20 in the state before the vehicle body is attached is set to a range slightly larger than the rotation range corresponding to the tilt adjustable range after the vehicle body is attached to the one side and the other side. ing. Since the setting is made in this way, the convex portions 92 and 92 of the lower bracket 20 do not come into contact with the protruding portion 94 of the housing 50 at the time of tilt adjustment after mounting the vehicle body.

  FIG. 10 is a schematic partial side view showing a method for assembling the lower bracket 20 to the housing 50. As shown by the arrow in FIG. 10, the lower bracket 20 is assembled to the housing 50 by inserting the lower bracket 20 into the lower bracket mounting position from obliquely above the rear side of the lower bracket mounting position. At this time, the reinforcing bridge 68 does not come into contact with the electric motor 52, the ECU 60, the vehicle body mounting bracket 18, or the like, and the reinforcing bridge 68 does not hinder assembly. Further, the convex portions 92 and 92 of the lower bracket 20 are only inserted with the protruding portion 94 of the housing 50 interposed therebetween. Thus, the assembly of the lower bracket 20 to the housing 50 can be easily performed.

  In this embodiment, since the tilt pivot shaft 70 is provided on the rear side of the rotating shaft 54 of the electric motor 52, the method of assembling the lower bracket 20 to the housing 50 is the easiest method shown in FIG. It is a method of attaching. If the rotation restricting mechanism is configured as in this embodiment, the ease of assembling the lower bracket 20 to the housing 50 as shown in FIG. 10 is not impaired. As a result, it is possible to restrict the rotation of the lower bracket 20 while maintaining the support rigidity of the vehicle body mounting bracket 18 with respect to the steering column 10 and without further impairing the assembling property of the lower bracket 20 to the housing 50. That is, the electric power steering device 1 can be easily assembled to the vehicle body. Further, since the assembly of the lower bracket 20 to the housing 50 is easy, an increase in cost related to the assembly of the electric power steering apparatus 1 can be suppressed.

  Thus, according to the present embodiment, in the state before the electric power steering device 1 is assembled to the vehicle body, excessive rotation of the lower bracket 20 can be restricted, and the assembly to the vehicle body can be facilitated. Further, after being mounted on the vehicle body, the support rigidity with respect to the steering column 10 is high, and as a result, the steering feeling is good, and impact energy can be absorbed smoothly at the time of a secondary collision. Furthermore, since the assembly of the lower bracket 20 to the housing 50 is easy, the effect that the assembly cost of the electric power steering apparatus 1 can be suppressed is also exhibited.

  In the above embodiment, the convex portions 92 and 92 are provided on one side plate 66 of the lower bracket 20 as a rotation preventing mechanism, and the protruding portion 94 is provided on one side of the housing 50 corresponding thereto. A pair of protrusions 92 and 92 may be provided on both side plates 66 and 66 of the bracket 20, and corresponding protrusions 94 and 94 may be provided on both sides of the housing 50. In the present embodiment, the housing 50 is provided with a through hole 78 and a single tilt pivot shaft 70 is inserted therethrough. Instead of the through hole 78, coaxial female screws are provided on the left and right side surfaces of the housing. Bolts may be inserted into the respective female screws via the side plates 66 and 66 of the lower bracket 20, and these bolts may be used as tilt pivot shafts.

DESCRIPTION OF SYMBOLS 1 Electric power steering device 2 Upper steering shaft 3 Steering wheel 5 Output shaft 6 Intermediate shaft 7 Steering gear assembly 8 Tie rod 10 Steering column 12 Upper column 14 Lower column 16 Distance bracket 18 Car body mounting bracket 20 Lower bracket 22 Power assist device 24 Switch bracket 26 Side plate 28 Connecting portion 30 Side plate 32 Flat plate portion 36 Upper plate 38 Car body mounting portion 40 Capsule 42 Bolt hole 44 Tilt adjusting long hole 46 Tightening bolt 48 Operation lever 50 Housing 52 Electric motor 54 Rotating shaft 56 Worm 58 Worm wheel 60 ECU
62, 64 Storage portion 66 Side plate 68 Reinforcement bridge 70 Tilt pivot shaft 72 Through hole 74 Car body mounting portion 76 Bolt hole 78 Through hole 80 Sleeve 82 Nut 86 Spacer 88 Cylinder portion 90 Flange portion 91 Recess portion 92 Protrusion portion 93 Reinforcement rib 94 Protrusion portion

Claims (5)

A steering shaft to which a steering wheel is mounted at the rear end;
A steering column that rotatably supports the steering shaft;
A tilt adjustment mechanism capable of rotating the steering column about a tilt pivot shaft and positioning the steering column at a desired tilt adjustment position;
An electric motor for generating an auxiliary steering torque is mounted, and a speed reduction mechanism comprising a worm connected to the rotating shaft of the electric motor and a worm wheel meshing with the worm is housed therein, and is connected to the front end portion of the steering column. Housing
A lower bracket fixed to the vehicle body side, facing the vehicle width direction with the housing in between, and having a pair of side plates that support the tilt pivot shaft;
The housing is provided with an engaging portion with the tilt pivot shaft, and the steering column is pivotally engaged with the tilt pivot shaft via the engaging portion so that the steering column is tilted with the tilt pivot shaft. In the electric power steering device that is rotatable about the rotation center,
The engaging portion of the housing is provided in a portion of the housing on the rear side of the rotating shaft of the electric motor,
A pair of convex portions projecting forward at a predetermined interval in the vertical direction are formed at a front end portion of at least one side plate of the lower bracket, and the housing is provided between the pair of convex portions. A protrusion that protrudes outward in the vehicle width direction from the protrusion is formed, and the pair of protrusions and the protrusion are formed on the tilt pivot of the lower bracket in a state before the vehicle body is assembled to the electric power steering device. An electric power steering apparatus comprising a rotation restricting mechanism for restricting a rotation of the steering column about a shaft to a predetermined range.   The rotation restricting mechanism is configured such that when the lower bracket rotates to one side with the tilt pivot shaft as a rotation center, one of the pair of convex portions contacts the protruding portion and rotates to the other side. The electric power steering apparatus according to claim 1, wherein the other of the pair of convex portions is in contact with the protruding portion.   The electric power steering apparatus according to claim 1 or 2, wherein the pair of side plates of the lower bracket are connected by a connecting member extending in a vehicle width direction.   The electric power steering apparatus according to claim 3, wherein the connecting portion connects rear ends of the pair of side plates. The electric power steering apparatus according to claim 3, wherein the pair of convex portions of the lower bracket are located on the front side of the tilt pivot shaft.

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