Automobile front body structure

Abstract

In order to configure a substrate for a control unit (32) that controls a motor (31) of an electric power steering device (3) so that said substrate is a single substrate, provided is an automobile front body structure (1) comprising: a front suspension member (11) that supports a steering rack (23); and the electric power steering device that includes the motor and the control unit. A longitudinal direction (L) of a main surface (321) of the control unit is formed to be larger than the diameter (D) of an outside surface (311) of the motor. The motor and the control unit are disposed between a front cross member (111) of the front suspension member and the steering rack. The control unit is disposed so that the longitudinal direction of the main surface is non-parallel to a straight line (T) connecting the front cross member and the steering rack in a cross section perpendicular to a left-right direction of the automobile.

Description

Automobile front body structure

[0001] The present invention relates to a front body structure of an automobile.

[0002] A vehicle underbody structure is known in which an electric power steering device is fixed to a front suspension member that supports a front wheel suspension (see Patent Document 1). In this vehicle underbody structure, the drive section (motor and ECU) of the electric power steering device is located rearward of the front cross member of the front suspension member and forward of the steering rack.

[0003] Japanese Patent Application Laid-Open No. 2018-2006

[0004] However, in the above-described conventional vehicle lower body structure, if the motor and ECU that constitute the drive unit of the electric power steering device were made to have the same circular shape, the area of ​​this circle would be smaller than the area of ​​a single board that is normally required for an ECU, which poses a problem that the ECU must have multiple boards.

[0005] The problem to be solved by the present invention is to provide a front body structure for an automobile in which the control unit for controlling the motor of an electric power steering device can be constructed from a single board.

[0006] The present invention solves the above problem by forming the longitudinal direction of the main surface of the control unit of an electric power steering device that drives the steering rack to be larger than the diameter of the outer surface of the motor, arranging the motor and control unit between the front cross member of the front suspension member and the steering rack, and arranging the control unit so that the longitudinal direction of its main surface is non-parallel to the straight line connecting the front cross member and the steering rack.

[0007] According to the present invention, the control unit for controlling the motor of the electric power steering device can be configured with a single board.

[0008] 4 is a schematic diagram showing an example of a steering device included in an embodiment of an automotive front body structure according to the present invention. FIG. 5 is a perspective view showing an entire embodiment of an automotive front body structure according to the present invention. FIG. 6 is a perspective view showing an enlarged view of the front cross member, steering rack, and electric power steering device of FIG. 2. FIG. 7 is a plan view showing an enlarged view of the front cross member, steering rack, and electric power steering device of FIG. 2. FIG. 8 is a bottom view showing an enlarged view of the front cross member, steering rack, and electric power steering device of FIG. 2. FIG. 9 is a perspective view showing a state in which a harness and a connector are attached to the control unit of FIG. 2. FIG. 10 is a cross-sectional view taken along line VII-VII of FIG. 4. FIG. 11 is a cross-sectional view taken along line VIII-VIII of FIG. 10. FIG. 11 is a cross-sectional view taken along line VIII-VIII of FIG. 10. Fig. 11 is a cross-sectional view perpendicular to the left-right direction of the automobile, showing the electric power steering device and the protector of Fig. 10. Fig. 12 is a perspective view showing the first vibration-isolating rubber and the second vibration-isolating rubber of Fig. 10.

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing an example of a steering device 2 included in an embodiment of an automobile front body structure according to the present invention. Known types of electric power steering device 3 included in the steering device 2 include a column assist type, a pinion assist type, and a rack assist type. The column assist type is a type in which a reducer and a motor are provided in the column section of the steering shaft inside the vehicle cabin to drive the column shaft. The pinion assist type is a type in which a motor is mounted in a pinion case inside the engine compartment to drive a pinion gear that meshes with the rack. The rack assist type is a type in which a motor and a ball screw are mounted in the rack section of the steering inside the engine compartment to directly drive the rack.

[0010] As described in the Background Art section above, the automobile front body structure 1 of this embodiment is intended to solve the problem that occurs when the motor (electric motor) 31 of the electric power steering device 3 and its control unit 32 are mainly disposed on the steering rack 23 of the steering device 2, and is therefore preferably applicable to a pinion-assist or rack-assist electric power steering device 3. In the embodiment of the present invention shown below, the present invention will be described by exemplifying a steering device 2 that includes a pinion-assist electric power steering device 3 as a representative of these.

[0011] 1 includes a steering wheel 21, a steering shaft 22, a steering rack 23, a tie rod 24, a knuckle 25, steering wheels 26, a torque sensor 27, and an electric power steering device 3. The electric power steering device 3 of the embodiment is a pinion-assist type electric power steering device, particularly one called a double pinion type.

[0012] The steering wheel 21 is connected to a steering shaft 22, and the steering force of the driver input to the steering wheel 21 is transmitted to a steering rack 23 via the steering shaft 22. The tip of the steering shaft 22 is connected to a pinion gear 221 that meshes with a rack gear 232 provided on a rack shaft 231 of the steering rack 23. The meshing structure between the pinion gear 221 of the steering shaft 22 and the rack gear 232 of the rack shaft 231 is a rack and pinion transmission mechanism, which converts the rotational motion of the steering wheel 21 into the linear motion of the rack shaft 231.

[0013] The left and right ends of the rack shaft 231 are connected to the tie rods 24 via joints, and the other end of the tie rods 24 is connected to the knuckle 25 via a joint. As a result, the linear movement of the rack shaft 231 in either the left or right direction is transmitted to the knuckle 25 via the tie rods 24, and as a result, the steered wheels 26 are steered.

[0014] As described above, the electric power steering device 3 of this embodiment is a double-pinion type electric power steering device, and is provided at a position different from the position where the pinion gear 221 of the steering shaft 22 and the rack gear 232 of the rack shaft 231 mesh with each other. The electric power steering device 3 of this embodiment includes a motor 31, a control unit (also referred to as an electronic control unit ECU) 32 that controls the drive of this motor 31, and a speed reducer 33.

[0015] That is, in the electric power steering device 3 of this embodiment, a pinion shaft 34 that is not part of the steering shaft 22 is provided at a position different from the position where the pinion gear 221 of the steering shaft 22 and the rack gear 232 of the rack shaft 231 mesh with each other. A pinion gear 341 is provided at the tip of the pinion shaft 34, and this pinion gear 341 is provided so as to mesh with the rack gear 232 of the rack shaft 231. The other end of the pinion shaft 34 is connected to the output shaft of the motor 31 via a reducer 33 formed of a worm gear and worm wheel or the like. This reducer 33 corresponds to an example of a gear train according to the present invention.

[0016] When the driver operates the steering wheel 21, the control unit 32 reads information such as the steering torque, steering angle, and vehicle speed detected by the torque sensor 27, calculates a target value for assist based on this information, and outputs this to the motor 31. As a result, the steering force transmitted from the steering wheel 21 to the rack shaft 231 via the steering shaft 22 and pinion gear 221 is added to the driving force of the motor 31 via the pinion shaft 34 and the reducer 33 to the rack shaft 231.

[0017] Next, an automobile front body structure 1 according to this embodiment will be described. Fig. 2 is a perspective view showing one embodiment of the automobile front body structure 1 according to the present invention. Fig. 3 is an enlarged perspective view of the front cross member 111, steering rack 23, and electric power steering device 3 shown in Fig. 2. Fig. 4 is a plan view of the same, and Fig. 5 is a bottom view of the same. Parts of harnesses 322, 323 and connectors 324, 325 connected to the control unit 32, and a protector 35 attached to the front of the control unit 32 are not shown in Figs. 1 to 12 below. In Figs. 1 to 12 below, arrow FR indicates the front of the automobile, arrow RR indicates the rear of the automobile, arrow LH indicates the left side of the automobile, arrow RH indicates the right side of the automobile, arrow UP indicates the top of the automobile, and arrow DW indicates the bottom of the automobile. Furthermore, the linear direction of the arrows RH-LH is the left-right direction of the vehicle (the width direction of the vehicle), the linear direction of the arrows FR-RR is the front-rear direction of the vehicle, and the linear direction of the arrows Up-DW is the up-down direction of the vehicle (the height direction of the vehicle).

[0018] Of the steering device 2 and electric power steering device 3 having the above-described configuration, the rack housing 233 of the steering rack 23 is fixed to a front suspension member 11 provided on the front body of the automobile as shown in Figure 2, and the electric power steering device 3 is fixed to this rack housing 233.

[0019] The front suspension member 11 of this embodiment includes a front cross member 111 extending in the left-right direction of the vehicle, a pair of side members 112, 113 extending in the front-rear direction of the vehicle from both ends of the front cross member 111, and a rear cross member 114 extending in the left-right direction of the vehicle and connecting the rear ends of the pair of side members 112, 113. The front suspension member 11 of this embodiment is fixed to structural members (such as front side members) that form an engine compartment of the vehicle body (not shown).

[0020] 2, the rack housing 233 of the steering rack 23 of this embodiment extends in the left-right direction of the vehicle and is fastened to a pair of side members 112, 113 using bolts. The rack housing 233 is disposed substantially parallel to the front cross member 111, on the rear side in the longitudinal direction of the vehicle, and on the upper side in the vertical direction of the vehicle. The components of the electric power steering device 3 of this embodiment are laid out in the space between the front cross member 111 and the rack housing 233.

[0021] 2 to 5, a gear housing 331 of the reducer 33 is fixed to the right side of a motor housing 312 of the motor 31 with bolts or the like, and a control unit housing 326 of the control unit 32 is fixed to the left side of the motor housing 312 of the motor 31 with bolts or the like. Although not shown in the drawings, the output shaft of the motor 31 meshes with one of the gears of the reducer 33 inside the motor housing 312 and the gear housing 331.

[0022] 3, 4, and 6, the gear housing 331 of the reducer 33 is firmly attached to the rack housing 233 of the steering rack 23 with bolts or the like. That is, the gear housing 331 of the reducer 33 is fixed to the rack housing 233, the motor housing 312 of the motor 31 is fixed to the gear housing 331, and the control unit housing 326 of the control unit 32 is fixed to the motor housing 312, so that the motor housing 312 and the control unit housing 326 are cantilevered by the rack housing 233.

[0023] 4, the gear housing 331 of this embodiment is disposed so that the front end of the gear housing 331 is located rearward in the longitudinal direction of the vehicle relative to the front end of the motor housing 312. Furthermore, as shown in FIG. 3, the gear housing 331 of this embodiment is disposed so that the upper end of the gear housing 331 is located higher in the vertical direction of the vehicle relative to the upper end of the motor housing 312.

[0024] The control unit housing 326, fixed to the left side of the motor housing 312 of the motor 31, has a flat, approximately rectangular parallelepiped shape and houses an electronic circuit board on which multiple electronic components and the like are mounted. The pair of opposing surfaces of the flat rectangular parallelepiped, which have the largest areas, are referred to as main surfaces 321. This electronic circuit board supplies driving power to the motor 31 and transmits control signals. FIG. 6 is a perspective view showing the control unit 32 of FIG. 2 with harnesses 322, 323 and connectors 324, 325 attached. The harness 322 and the connector 324 connected thereto are electric wires (weak voltage / small current) for transmitting control signals, and the harness 323 and the connector 325 connected thereto are electric wires (weak voltage / large current) for transmitting driving power.

[0025] Furthermore, in the control unit 32 of this embodiment, the electronic circuit board housed in the control unit housing 326 is configured as a single board, so that the longitudinal dimension L of the main surface 321 of the control unit housing 326 of the control unit 32 is larger than the diameter D of the outer surface 311 of the motor 31. FIG. 9A is a cross-sectional view perpendicular to the left-right direction of the automobile, showing the relative positions of the front cross member 111, the steering rack 23, and the electric power steering device 3 of FIG. 2. As shown in the figure, the main surface 321 of the control unit housing 326 of this embodiment is hexagonal, like a baseball home base, with a longitudinal dimension L1 and a lateral dimension S1. The outer surface 311 of the motor housing 312 of the motor 31 has a diameter D. The short-side dimension S1 of the main surface 321 of the control unit housing 326 is approximately the same length as the diameter D of the outer surface 311 of the motor housing 312, but the longitudinal dimension L1 of the main surface 321 of the control unit housing 326 is larger than the diameter D of the outer surface 311 of the motor 31.

[0026] In particular, in the automotive front body structure 1 of this embodiment, the motor 31, control unit 32, and reducer 33 that constitute the electric power steering device 3 are disposed in the space between the front cross member 111 of the front suspension member 11 and the rack housing 233 of the steering rack 23, as shown in Fig. 4. The control unit housing 326 of the control unit 32 is disposed so that, in a cross section perpendicular to the left-right direction of the vehicle (corresponding to a side view of the vehicle), the longitudinal direction L of the main surface 321 of the control unit housing 326 is non-parallel to a line T connecting the front cross member 111 and the rack housing 233 of the steering rack 23. Fig. 7 is a view taken along line VII-VII in Fig. 4, and Fig. 8 is a view taken along line VIII-VIII in Fig. 4, both of which are cross sections perpendicular to the left-right direction of the vehicle (corresponding to a side view of the vehicle).

[0027] Here, "arranging the control unit housing 326 so that the longitudinal direction L of the main surface 321 is non-parallel to the line T connecting the front cross member 111 and the rack housing 233 of the steering rack 23" means that, in a cross section perpendicular to the left-right direction of the vehicle, as shown in FIGS. 7 and 9A , the angle θ1 formed between the longitudinal direction L of the main surface 321 of the control unit housing 326 and the line T connecting the front cross member 111 and the rack housing 233 of the steering rack 23 satisfies 0° < θ1 < 180°. Note that the line T is a line connecting the cross-sectional center of the front cross member 111 and the cross-sectional center of the rack housing 233. In this case, the angle θ1 formed between the longitudinal direction L and the line T can preferably be 45°≦θ1≦135°, more preferably 60°≦θ1≦120°, and even more preferably 80°≦θ1≦100°.

[0028] Furthermore, in terms of the short side direction S of the main surface 321 of the control unit housing 326, which is orthogonal to the longitudinal direction L of the main surface 321 of the control unit housing 326, the short side direction S may be arranged so as to follow the straight line T in a cross section perpendicular to the left-right direction of the automobile. Here, "arranging the short side direction S so as to follow the straight line T" not only includes the short side direction S being parallel to the straight line T, but also includes the short side direction S being arranged at an angle within a relatively small range with respect to the straight line T. Specifically, the angle θ2 formed between the short side direction S of the main surface 321 and the straight line T may be -45°≦θ2≦45°, preferably -30°≦θ2≦30°, and more preferably -15°≦θ2≦15°.

[0029] As described above with reference to Fig. 6, the control unit 32 of this embodiment has a harness 322 for transmitting control signals and a connector 324 connected thereto, and a harness 323 for transmitting drive power and a connector 325 connected thereto. Fig. 9B is a cross-sectional view showing an example of the positional relationship between the front cross member 111 and the connectors 324, 325 of the electric power steering device 3 in a cross section perpendicular to the left-right direction of the vehicle. In the control unit 32 of this embodiment, as shown in the figure, some or all of the connectors are arranged so as to be located above the vehicle with respect to the upper end of the front cross member 111.

[0030] 9B, the entire connector 325 and connector 324 on the right side of the drawing are positioned above the vehicle relative to the upper end of the front cross member 111, and a portion of the connector 325 on the left side of the drawing is positioned above the vehicle relative to the upper end of the front cross member 111. The remaining portion of the connector 325 on the left side of the drawing is positioned so as to overlap the front cross member 111 in the vertical direction of the vehicle. This is to prevent direct interference between the front cross member 111 and the connectors 324, 325 in the event of a frontal collision.

[0031] 9C is a cross-sectional view perpendicular to the left-right direction of the vehicle, showing another example of the positional relationship between the front cross member 111 in FIG. 2 and the connectors 324, 325 of the electric power steering device 3. In the control unit 32 of the embodiment shown in the figure, the connectors 324, 325 are arranged so as to overlap with the front cross member 111 in the direction X of an object that has fallen on the road surface. In other words, the connectors 324, 325 are arranged in positions that will be hidden by the back surface of the front cross member 111 if an object that has fallen on the road surface flies in the direction X. In this case, the connectors 324, 325 may be arranged so that at least a portion of them overlap with the front cross member 111.

[0032] 10 is a perspective view showing the state in which a protector 35 is attached to the electric power steering device 3 of FIG. 2, FIG. 11 is a cross-sectional view perpendicular to the left-right direction of the automobile showing the electric power steering device 3 and protector 35 of FIG. 10, and FIG. 12 is a perspective view showing the first vibration-isolating rubber 36 and the second vibration-isolating rubber 37 of FIG. 10.

[0033] The electric power steering device 3 of this embodiment further includes a protector 35 provided on the front side in the longitudinal direction of the vehicle of the connectors 324, 325. This protector has a bent plate-like shape that is C-shaped in a cross section perpendicular to the left-right direction of the vehicle as shown in Figure 11, and is formed in a shape having a front side surface 351, a rear side surface 352, and a top surface 353. Furthermore, this protector 35 includes a covering portion 356 that extends from the front side surface 351 so as to face the main surface 321 of the control unit 32, as shown in Figure 10.

[0034] The protector 35 of this embodiment has a first fixing portion 354 attached to the steering rack 23 at the bottom of the rear side surface 352, and a second fixing portion 355 attached to the gear housing 331 at the rear of the top surface 353, and is attached by bridging between the rack housing 233 of the steering rack 23 and the gear housing 331 of the reducer 33 by means of these first fixing portion 354 and second fixing portion 355.

[0035] Furthermore, a first vibration-isolating rubber 36 is provided between a top surface 353 of the protector 35 and a side surface of the control unit housing 326 of the control unit 32, in front of the top surface 353. Furthermore, a second vibration-isolating rubber 37 is provided between a front side surface 351 of the protector 35 and a side surface of the control unit housing 326 of the control unit 32. This is to suppress vibrations in the front-to-rear direction of the protector 35. The first vibration-isolating rubber 36 and the second vibration-isolating rubber 37 are made of an elastic body such as synthetic rubber, and are fixed to the back surface of the protector 35 using double-sided tape, adhesive, or the like.

[0036] As described above, according to the automotive front body structure 1 of this embodiment, the automotive front body structure 1 includes the front suspension member 11 supporting the steering rack 23 and the electric power steering device 3 having the motor 31 and the control unit 32. In this structure, the longitudinal direction L of the main surface 321 of the control unit 32 is larger than the diameter D of the outer surface 311 of the motor 31. The motor 31 and the control unit 32 are disposed between the front cross member 111 of the front suspension member 11 and the steering rack 23. The control unit 32 is disposed such that the longitudinal direction L of the main surface 321 is non-parallel to the line T connecting the front cross member 111 and the steering rack 23 in a cross section perpendicular to the left-right direction of the vehicle. This allows the control unit 32 to be disposed between the front cross member 111 and the steering rack 23 even if the main surface 321 of the control unit 32 is enlarged. As a result, the control unit 32 can be configured using a single circuit board.

[0037] Furthermore, according to the automotive front body structure 1 of this embodiment, the control unit 32 is disposed so that, in a cross section perpendicular to the left-right direction of the vehicle, the short side direction S of the main surface 321 is aligned with the straight line T connecting the front cross member 111 and the steering rack 23. Therefore, even if the main surface 321 of the control unit 32 is made even larger, the control unit 32 can be disposed between the front cross member 111 and the steering rack 23. As a result, the control unit 32 can be configured with a single circuit board.

[0038] Furthermore, according to the automobile front body structure 1 of this embodiment, the control unit 32 has connectors 324, 325 to which the harnesses 322, 323 are connected, and part or all of the connectors 324, 325 are positioned above the automobile relative to the upper end of the front cross member 111. This prevents the front cross member 111 from deforming and interfering with the connectors 324, 325 even in the event of a head-on collision of the automobile. As a result, the risk of a short circuit occurring due to damage to the connectors is reduced.

[0039] Furthermore, according to the automobile front body structure 1 of this embodiment, the remaining portions of the connectors 324, 325 are positioned so as to overlap the front cross member 111 in the vertical direction of the automobile, or the connectors 324, 325 are positioned so as to overlap the front cross member 111 in the direction F of the impact of an object that has fallen on the road surface. Therefore, even if an object that has fallen on the road surface attempts to fly toward the connectors 324, 325, it will collide with the front cross member 111, thereby preventing damage to the connectors 324, 325. As a result, the risk of a short circuit occurring due to damage to the connectors 324, 325 can be reduced.

[0040] Furthermore, according to the automobile front body structure 1 of this embodiment, the electric power steering device 3 further has housings 312, 331 that accommodate the motor 31 and the reducer (gear train) 33 connected to the output shaft of the motor 31, and a protector 35 provided in front of the connectors 324, 325, and the protector 35 is attached by spanning the steering rack 23 and the housings 312, 331.

[0041] By providing the protector 35, the connectors 324, 325 are protected even in the event of a head-on collision of the vehicle, thereby reducing the risk of a short circuit occurring due to damage to the connectors 324, 325. In addition, by attaching the protector 35 across the steering rack 23 and the housings 312, 331, the support rigidity of the housings 312, 331 with respect to the steering rack 23 is improved compared to when the protector 35 is attached only to the housings 312, 331. As a result, the resonant frequency of the steering rack and housings 312, 331 can be made higher than the resonant frequency of the powertrain (drive motor, gear, inverter), preventing these resonant frequencies from overlapping and suppressing deterioration of noise and vibration performance. Furthermore, if the protector 35 is attached only to the housings 312, 331, it would be necessary to provide a separate bracket or the like between the steering rack 23 and the housings 312, 331 in order to improve the support rigidity of the housings 312, 331 relative to the steering rack 23. However, if the protector 35 is provided, there is no need to provide such a bracket.

[0042] Furthermore, according to the automobile front body structure 1 of this embodiment, the housings 312, 331 include a motor housing 312 that houses the motor 31 and a gear housing 331 that houses the reducer (gear train) 33, and the gear housing 331 is arranged so that the front end of the gear housing 331 is located rearward of the front end of the motor housing 312 in the longitudinal direction of the automobile, and the upper end of the gear housing 331 is located higher in the vertical direction of the automobile than the upper end of the motor housing 312, and the protector 35 has a bent plate-like member so that its cross section perpendicular to the left-right direction of the automobile is C-shaped, and is formed into a shape having a front side surface 351, a rear side surface 352 and a top surface 353, and has a first fixing portion 354 attached to the steering rack 23 at the bottom of the rear side surface 352, and a second fixing portion 355 attached to the gear housing 331 at the rear of the top surface 353. By providing the first fixing portion 354 attached to the steering rack 23 at the bottom of the rear side surface 352 and the second fixing portion 355 attached to the gear housing 331 at the rear of the top surface 353, the protector 35 can be attached to span the steering rack 23 and the housings 312, 331 while satisfying the layout and ease of tightening bolts, etc. Furthermore, by providing the second fixing portion 355 on the gear housing 331 instead of the motor housing 312, the distance between the first fixing portion 354 and the second fixing portion 355 in the left-right direction of the vehicle can be increased, and vibration of the protector 35 in the left-right direction of the vehicle with the first fixing portion 354 as a fulcrum can be suppressed.

[0043] Furthermore, according to the automobile front body structure 1 of this embodiment, a first vibration-isolating rubber 36 is provided between the top surface 353 of the protector 35 and the control unit 32, in front of the top surface 353. In the protector 35 of this embodiment, the distance in the front-to-rear direction between the first fixing portion 354 and the second fixing portion 355 is short, so the protector 35 vibrates in the front-to-rear direction with the first fixing portion 354 as a fulcrum. However, by providing the first vibration-isolating rubber 36, the vibration of the protector 35 in the front-to-rear direction can be suppressed.

[0044] Furthermore, according to the automobile front body structure 1 of this embodiment, a second vibration-damping rubber 37 is provided between the front side surface 351 of the protector 35 and the control unit 32, so that when the protector 35 vibrates in the fore-and-aft direction with the first fixing portion 354 as a fulcrum, the provision of the second vibration-damping rubber 37 can further suppress the fore-and-aft vibration of the protector 35.

[0045] Furthermore, according to the automobile front body structure 1 of this embodiment, the protector 35 includes a covering portion 356 that extends from the front side surface 351 to face the main surface 321 of the control unit 32, thereby preventing the front cross member 111 from interfering with the control unit 32 even in the event of a head-on collision of the automobile. As a result, the risk of a short circuit occurring due to damage to the control unit 32 can be reduced.

[0046] DESCRIPTION OF SYMBOLS 1...Automobile front body structure 11...Front suspension member 111...Front cross member 112, 113...Side member 114...Rear cross member 2...Steering device 21...Steering wheel 22...Steering shaft 221...Pinion gear 23...Steering rack 231...Rack shaft 232...Rack gear 233...Rack housing 24...Tie rod 25...Knuckle 26...Steering wheel 27...Torque sensor 3...Electric power steering device 31...Motor 311...Outer surface 312...Motor housing 32...Control unit L...Longitudinal direction S...Shortitudinal direction 321...Main surface 322, 323...Harness 324, 325...Connector 326...Control unit housing 33...Reduction gear 331...Gear housing 34...Pinion shaft 341...Pinion gear 35...Protector 351...Front side surface 352...Rear side surface 353...Top surface 354...First fixing portion 355...Second fixing portion 356...Covering portion 36...First vibration-isolating rubber 37...Second vibration-isolating rubber T...Straight line connecting the front cross member and the steering rack

Claims

1. A front body structure for an automobile including a front suspension member that supports a steering rack, and an electric power steering device having a motor and a control unit, wherein the longitudinal direction of the main surface of the control unit is formed larger than the diameter of the outer surface of the motor, the motor and the control unit are arranged between the front cross member of the front suspension member and the steering rack, and the control unit is arranged so that the longitudinal direction of the main surface is non-parallel to the line connecting the front cross member and the steering rack in a cross section perpendicular to the left-right direction of the automobile.

2. A front body structure for an automobile as described in claim 1, wherein the control unit is arranged so that the short side of the main surface is aligned with a straight line connecting the front cross member and the steering rack in a cross section perpendicular to the left-right direction of the automobile.

3. A front body structure for an automobile as set forth in claim 1 or 2, wherein the control unit has a connector to which a harness is connected, and the connector is positioned so that part or all of it is located above the automobile relative to the upper end of the front cross member.

4. A front body structure for an automobile according to claim 3, wherein the remaining portion of the connector is positioned so as to overlap the front cross member in the vertical direction of the automobile.

5. A front body structure for an automobile as set forth in claim 3 or 4, wherein the connector is positioned so as to overlap the front cross member in the direction of an object that has fallen to the road surface.

6. The front body structure for an automobile according to any one of claims 3 to 5, wherein the electric power steering device further comprises a housing that houses the motor and a gear train connected to the output shaft of the motor, and a protector provided in front of the connector, the protector being attached so as to span between the steering rack and the housing.

7. The front body structure of an automobile as described in claim 6, wherein the housing includes a motor housing that houses the motor and a gear housing that houses the gear train, the gear housing is arranged so that the front end of the gear housing is located rearward of the front end of the motor housing in the longitudinal direction of the automobile and the upper end of the gear housing is located above the upper end of the motor housing in the vertical direction of the automobile, the protector is shaped like a bent plate member so that its cross section perpendicular to the left-right direction of the automobile is C-shaped, and is formed into a shape having front and rear sides and a top surface, the protector having a first fixing part attached to the steering rack at the bottom of the rear side surface, and a second fixing part attached to the gear housing at the rear of the top surface.

8. The automobile front body structure according to claim 7, wherein a first vibration-isolating rubber is provided between the top surface of the protector and the control unit and in front of the top surface.

9. The automobile front body structure according to claim 7 or 8, wherein a second vibration-isolating rubber is provided between the front side surface of the protector and the control unit.

10. An automobile front body structure according to any one of claims 6 to 9, wherein the protector includes a covering portion extending from the front side surface to face the main surface of the control unit.

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