Steering device

Abstract

To provide a steering device that can provide a wide mounting space for an on-vehicle device disposed above a gear housing fixed to a front end portion of a steering column and easily ensures a thickness of a portion of the gear housing, which is located above a speed reducer.SOLUTION: A gear housing 11 includes a recess 34 recessed radially inward of portions located on both sides in a circumferential direction in an upper end portion on the outer circumferential surface and including a deepest part P in a portion in the front-back direction. The deepest part P is located on the back side or the front side of an upper end portion of a speed reducer (on the back side in the illustrated example).SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a steering device for applying a steering angle to the steered wheels of an automobile. [Background technology]

[0002] Generally, a steering device for an automobile is configured to transmit the rotation of the steering wheel operated by the driver to the pinion shaft of a steering gear unit via a steering shaft, an intermediate shaft, etc., and to apply a steering angle to the steered wheels by converting the rotational motion of the pinion shaft into linear motion of the rack shaft of the steering gear unit.

[0003] In the field of steering devices, electric power steering devices configured to apply auxiliary power to a steering force transmission path to reduce the force required to operate the steering wheel have become widespread. Electric power steering devices are broadly classified by the structure of the auxiliary power application location. For example, a column-assist electric power steering device that applies auxiliary power to a steering shaft includes a steering column supported on a vehicle body, a steering shaft rotatably supported inside the steering column and having a steering wheel attached to its rear end, a gear housing fixed to the front end of the steering column, a torque sensor and a reducer housed inside the gear housing, and an electric motor supported by the gear housing. The torque sensor detects the direction and magnitude of torque applied from the steering wheel to the steering shaft. The electric motor is driven and controlled using a detection signal from the torque sensor and applies auxiliary power to the steering shaft via the reducer. As a result, the force required for the driver to operate the steering wheel is reduced.

[0004] Meanwhile, in recent years, development of steer-by-wire steering systems has progressed, which include a steering unit to which a steering wheel is attached and a steering unit electrically connected to the steering unit for applying a steering angle to the left and right steered wheels. In a steer-by-wire steering system, the steering unit detects the steering angle of the steering wheel using a steering angle sensor, and based on the detection signal from the steering angle sensor, an actuator of the steering unit is driven to apply a steering angle to the steered wheels. The steering unit also has a reaction force application function that applies a reaction force to the steering wheel. To achieve this, the steering unit includes a steering column supported on the vehicle body, a steering shaft rotatably supported inside the steering column and having the steering wheel attached to its rear end, a gear housing fixed to the front end of the steering column, a reducer housed inside the gear housing, an electric motor supported by the gear housing, and a torque sensor. The torque sensor detects the direction and magnitude of torque applied to the steering shaft from the steering wheel. The electric motor is controlled by using a detection signal from a torque sensor and a detection signal from a steering angle sensor, and applies a reaction force to the steering wheel via a reducer and a steering shaft.

[0005] Recently, an increasing number of vehicles are being equipped with head-up display devices (HUDs) as in-vehicle devices that allow the driver to check information such as driving speed without taking their eyes off the road. The head-up display devices project information such as driving speed from below onto a portion of the vehicle windshield that is located in front of the driver's face. For this reason, head-up display devices are disposed above the steering system, as described in, for example, DE102018202562A1 (Patent Document 1) and Japanese Patent No. 6377501 (Patent Document 2). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] DE102018202562A1 [Patent Document 2] Patent No. 6377501 Summary of the Invention [Problem to be solved by the invention]

[0007] The specific location of the head-up display device above the steering system is determined based on its relationship with other surrounding components, but one proposal under consideration is to place the head-up display device above the gear housing that constitutes the steering system. In this case, it is necessary to design the gear housing so that it does not interfere with the head-up display device.

[0008] When implementing such a design, it is conceivable to provide a recess in the upper end of the outer peripheral surface of the gear housing to avoid interference with the head-up display device, which would allow for a larger installation space for the head-up display device.

[0009] However, in the radial direction about the central axis of the steering column, the inner diameter of the portion of the gear housing located radially outward from the reducer needs to be slightly larger than the outer diameter of the reducer, which is determined by the performance required of the reducer. Therefore, depending on the type of recess provided at the upper end of the outer peripheral surface of the gear housing, it may be difficult to ensure the required thickness of the portion of the gear housing located above the reducer.

[0010] The present invention aims to provide a steering device that can secure a large installation space for an on-vehicle device placed above a gear housing fixed to the front end of a steering column, and that can easily secure the thickness of the portion of the gear housing located above a reducer. [Means for solving the problem]

[0011] A steering device according to one aspect of the present invention includes a steering column supported on a vehicle body, a gear housing fixed to a front end of the steering column, and a reducer accommodated inside the gear housing.

[0012] The gear housing has a recess at the upper end of its outer surface, which is located radially inward relative to the portions located on both sides in the circumferential direction and has a deepest portion in a portion in the front-to-rear direction, and the deepest portion is located rearward or forward relative to the upper end of the reducer.

[0013] In a steering device according to a first aspect of the present invention, the gear housing includes a front housing that houses the reducer therein and has at its rear end an annular front mating surface facing rearward, and a rear housing that has at its front end an annular rear mating surface that abuts against the front mating surface. The recess is provided in an upper end of the outer peripheral surface of the gear housing in a front-to-rear range that includes the same front-to-rear position as the abutment portion between the front mating surface and the rear mating surface, and the deepest portion is located rearward of the upper end of the reducer.

[0014] In the steering device of the first aspect of the present invention, a configuration can be employed in which the deepest portion is located at the same position in the front-to-rear direction as the contact portion between the front mating surface and the rear mating surface.

[0015] In a steering device of a first aspect of the present invention, a configuration can be adopted in which the front housing has a front mating surface on the inner peripheral surface of the rear end, the rear housing has a rear mating surface on the outer peripheral surface of the front end that matings with the front mating surface, the front mating surface having a protruding flat surface at its upper end, which is a circumferential portion located radially inside the recess, and that protrudes radially inward more than the portions located on both circumferential sides, and the rear mating surface has a retracted flat surface at its upper end that is retracted radially inward more than the portions located on both circumferential sides and that engages with the protruding flat surface.

[0016] A steering device according to a second aspect of the present invention includes a torque sensor disposed inside the gear housing. The gear housing includes a front housing that houses the reducer therein, a rear housing that is disposed adjacent to the rear side of the front housing and houses the torque sensor therein, and has an annular front mating surface facing rearward at its rear end, and a rear bracket that has an annular rear mating surface at its front end that abuts against the front mating surface. The recess is provided in an upper end of the outer peripheral surface of the gear housing in a longitudinal range that includes the same longitudinal position as the abutment portion between the front mating surface and the rear mating surface, and the deepest portion is located rearward of the upper end of the reducer.

[0017] In the steering device of the second aspect of the present invention, a configuration can be adopted in which the deepest portion is located at the same fore-and-aft position as the abutment portion between the front mating surface and the rear mating surface and / or rearward of the abutment portion.

[0018] In a steering device of a second aspect of the present invention, a configuration can be adopted in which the rear housing has a front mating surface on the inner peripheral surface of the rear end portion, the rear bracket has a rear mating surface on the outer peripheral surface of the front end portion that matings with the front mating surface, the front mating surface having, at its upper end, a circumferential portion located radially inside the recess, a protruding flat portion that protrudes radially inward beyond portions located on both circumferential sides, and the rear mating surface has, at its upper end, a retracted flat portion that is retracted radially inward beyond portions located on both circumferential sides and that engages with the protruding flat portion.

[0019] In a steering device according to a third aspect of the present invention, the gear housing includes a rear housing that houses the reducer therein and has, at its front end, an annular rear mating surface facing forward, and a front housing that has, at its rear end, an annular front mating surface that abuts against the rear mating surface. The recess is provided in an upper end of the outer peripheral surface of the gear housing in a front-to-rear range that includes the same front-to-rear position as the abutment portion between the front mating surface and the rear mating surface, and the deepest portion is located forward of the upper end of the reducer.

[0020] In the steering device of the third aspect of the present invention, a configuration can be adopted in which the deepest portion is located at the same fore-and-aft position as the abutment portion between the front mating surface and the rear mating surface and / or further forward than the abutment portion.

[0021] In a steering device of a third aspect of the present invention, a configuration can be adopted in which the rear housing has a rear mating surface on the inner peripheral surface of the front end portion, the front housing has a front mating surface on the outer peripheral surface of the rear end portion that matings with the rear mating surface, the rear mating surface having a protruding flat surface at its upper end, which is a circumferential portion located radially inside the recess, and that protrudes radially inward more than portions located on both circumferential sides, and the front mating surface has a retracted flat surface at its upper end that is retracted radially inward more than portions located on both circumferential sides and that engages with the protruding flat surface.

[0022] A steering device according to one aspect of the present invention further includes a steering shaft rotatably supported inside the steering column and having a steering wheel attached to its rear end, an output shaft connected to the front end of the steering shaft and rotatably supported inside the gear housing, and a torque sensor housed inside the rear housing and detecting torque input from the steering wheel to the steering shaft. The torque detected by the torque sensor is used to control the drive of an electric motor supported in the gear housing. The output torque of the electric motor is transmitted to the output shaft via the reducer. In the steering device according to one aspect of the present invention, the reducer is a worm reducer including a worm wheel fitted and fixed to the output shaft and a worm meshing with the worm wheel and driven to rotate by the electric motor, and the upper end of the reducer is the upper end of the worm wheel.

[0023] A steering device according to one embodiment of the present invention has a tilt shaft that is arranged in the width direction of the vehicle body and that supports the gear housing so that it can swing relative to the vehicle body, and the central axis of the tilt shaft is located at a longitudinal position that is included in the longitudinal range in which the recess is located.

[0024] In the steering device according to one aspect of the present invention, the central axis of the tilt shaft is located at the same position in the front-to-rear direction as the contact portion between the front mating surface and the rear mating surface.

[0025] In one embodiment of the steering device of the present invention, the front housing has front joining portions that protrude radially outward at multiple circumferential locations and are used to join the front housing and the rear housing to each other, and the rear housing has rear joining portions that protrude radially outward at multiple circumferential locations and are used to join the front housing and the rear housing to each other, and each of the front joining portions and the rear joining portions is positioned below the upper edge of the recess.

[0026] In a steering device according to one aspect of the present invention, each of the front joint portion and the rear joint portion is not positioned above the deepest portion of the recessed portion.

[0027] A steering device according to one aspect of the present invention is used as a steer-by-wire steering device.

[0028] A steering device according to one aspect of the present invention is used as an electric power steering device. [Effects of the Invention]

[0029] According to one aspect of the steering device of the present invention, it is possible to secure a large installation space for an on-board device that is placed above a gear housing fixed to the front end of the steering column, and it is also easy to secure a sufficient thickness for the portion of the gear housing that is located above the reducer. [Brief explanation of the drawings]

[0030] [Figure 1] FIG. 1 is a schematic diagram showing the overall configuration of a steering device according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view of the steering unit of the first example. [Figure 3] FIG. 3 is a side view of the steering unit of the first example. [Figure 4] FIG. 4 is a view of the steering unit of the first example seen from above. [Figure 5] FIG. 5 is a rear view of the steering unit of the first example. [Figure 6] FIG. 6 is a cross-sectional view taken along line AA in FIG. [Figure 7] FIG. 7 is an enlarged view of the left end of FIG. [Figure 8] FIG. 8 is a perspective view of the front housing of the first example. [Figure 9] FIG. 9 is a view of the front housing of the first example as seen from the rear side. [Figure 10] FIG. 10 is a view of the front housing of the first example seen from above. [Figure 11] FIG. 11(a) is a cross-sectional view taken along line BB in FIG. 9, and FIG. 11(b) is a view corresponding to FIG. 11(a) and relating to the structure of a comparative example. [Figure 12] FIG. 12 is a perspective view of the rear housing of the first example. [Figure 13] FIG. 13 is a view of the rear housing of the first example as seen from the front side. [Figure 14] FIG. 14 is a top view of the rear housing of the first example. [Figure 15] FIG. 15 shows a second example of the embodiment, and is a view corresponding to the left end of FIG. [Figure 16] FIG. 16 shows a second example and corresponds to the left end of FIG. [Figure 17] FIG. 17 is a diagram corresponding to FIG. 7 and shows a third embodiment of the present invention. [Figure 18] FIG. 18 is a partially enlarged view of FIG. [Figure 19]FIG. 19 is a side view of a portion corresponding to FIG. 7, relating to the third example. [Figure 20] FIG. 20 is a rear view of FIG. [Figure 21] FIG. 21 is a diagram corresponding to the upper right portion of FIG. 19 and relates to a fourth embodiment of the present invention. [Figure 22] FIG. 22 is a view corresponding to the upper end of FIG. 20 and relates to the fourth example. [Figure 23] FIG. 23 is a diagram corresponding to FIG. 7 and shows a fifth embodiment of the present invention. [Figure 24] FIG. 24 is a side view of a portion corresponding to FIG. 23, relating to the fifth example. [Figure 25] FIG. 25 is a view seen from the rear side of FIG. [Figure 26] FIG. 26 is a front view of FIG. [Figure 27] FIG. 27 is a diagram corresponding to the upper left part of FIG. 24 and related to a sixth embodiment of the present invention. [Figure 28] FIG. 28 is a view corresponding to the upper end of FIG. 26 and related to the sixth example. [Figure 29] FIG. 29 is a side view showing a steering device according to a seventh example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0031] [Example 1] A first embodiment of the present invention will be described with reference to FIGS. 1 to 14. FIG.

[0032] A steering device according to one aspect of the present invention, including the steering device of this example, is intended for a steering device in which an in-vehicle device such as a head-up display device is disposed above a gear housing fixed to the front end of a steering column. In this example, the steering device of the present invention is applied to a steer-by-wire steering device. In the following description, the "front-rear direction" refers to the front-rear direction of the vehicle, the "up-down direction" refers to the up-down direction of the vehicle, and the "width direction" refers to the width direction of the vehicle.

[0033] The overall configuration of the steer-by-wire steering device 1 of this example is shown schematically in Fig. 1 and includes a steering unit 3 to which a steering wheel 2 is attached, a steering unit 5 that steers left and right steered wheels 4, and a control device (ECU) 6. The steering unit 3 and the steering unit 5 are not mechanically connected, but are electrically connected.

[0034] Steering unit 3 measures the operation of steering wheel 2 by the driver using torque sensor 13 (see FIGS. 6 and 7) and a steering angle sensor (not shown), and inputs the measurement results to control device 6. Control device 6 drives steering actuator 7 of steering unit 5 based on various signals indicating the driving situation, such as the steering torque measured by torque sensor 13, the steering angle measured by the steering angle sensor, vehicle speed, yaw rate, and acceleration. This displaces linearly moving members such as a rack shaft and a screw shaft in the width direction, pushing and pulling left and right tie rods 8 and applying a steering angle to the left and right steered wheels 4. Control device 6 controls the drive of electric motor 15 (shown only in FIG. 5) of steering unit 3 based on the various signals indicating the driving situation, and applies a steering reaction force to steering wheel 2 according to the driving situation.

[0035] As shown in FIGS. 2 to 7 (particularly FIG. 6), the steering unit 3 includes a steering column 9, a gear housing 11, and a reducer .

[0036] The steering column 9 is cylindrical overall and is supported by the vehicle body. The steering column 9 rotatably supports a steering shaft 10 on its inner side. The steering wheel 2 (see FIG. 1) is attached to the rear end of the steering shaft 10. A gear housing 11 is fixed to the front end of the steering column 9. The gear housing 11 rotatably supports an output shaft 12 on its inner side, and houses a torque sensor 13 and a reducer 14. The output shaft 12 is connected to the front end of the steering shaft 10. The torque sensor 13 detects the torque input from the steering wheel 2 to the steering shaft 10. The reducer 14 transmits the output torque of an electric motor 15 (see FIG. 5) supported by the gear housing 11 to the output shaft 12. As a result, a steering reaction force is applied to the steering wheel 2 via the output shaft 12 and the steering shaft 10.

[0037] In this example, the steering column 9 is supported on the vehicle body via a column support device 16 arranged above the steering column 9.

[0038] The steering unit 3 of this example has a telescopic function that allows adjustment of the front-rear position of the steering wheel 2. For this purpose, the steering column 9 and the steering shaft 10 are configured so that their entire lengths can be extended and contracted.

[0039] Specifically, the steering column 9 comprises an outer column 17 arranged in the middle in the front-to-rear direction, a front inner column 18 fitted within the front side of the outer column 17 so as to be able to move relative to the front-to-rear direction, and a rear inner column 19 fitted within the rear side of the outer column 17 so as to be able to move relative to the front-to-rear direction. The gear housing 11 is fixed to the front end portion of the front inner column 18.

[0040] The steering shaft 10 is formed by spline-engaging a front shaft 20 disposed on the front side with a rear shaft 21 disposed on the rear side to enable torque transmission and relative axial displacement. The rear shaft 21 is rotatably supported inside the rear inner column 19 using a plurality of (two in the illustrated example) rolling bearings 22a, 22b. The rear end of the rear shaft 21 protrudes rearward from the inside of the rear inner column 19, and the steering wheel 2 is attached to this rear end.

[0041] The column support device 16 includes a fixed bracket 23 that is fixed to the vehicle body, a displacement bracket 24 that is arranged below the fixed bracket 23, and a linear guide 25 (see FIG. 5) that is assembled between the lower surface of the fixed bracket 23 and the upper surface of the displacement bracket 24 and enables relative displacement of the displacement bracket 24 in the front-to-rear direction with respect to the fixed bracket 23. The outer column 17 is supported by the displacement bracket 24.

[0042] 2 to 6, the steering unit 3 of this example includes an electric front telescopic actuator 26 that is assembled so as to bridge between the fixed bracket 23 and the displacement bracket 24. The front telescopic actuator 26 is capable of displacing the displacement bracket 24 relative to the fixed bracket 23 in the front-to-rear direction.

[0043] As shown in Figures 2 to 6, the steering unit 3 of this example is equipped with an electric rear telescopic actuator 27 that is assembled so as to bridge between the outer column 17 and the rear inner column 19. The rear telescopic actuator 27 is capable of displacing the rear inner column 19 relative to the outer column 17 in the front-to-rear direction.

[0044] The steering unit 3 in this example has a tilt function that makes it possible to adjust the vertical position of the steering wheel 2. To achieve this, in this example, the steering column 9, steering shaft 10, and gear housing 11 are supported by a fixed bracket 23 that is fixed to the vehicle body so as to be able to swing up and down about a tilt shaft 28 that is arranged in the width direction. In this example, one tilt shaft 28 is provided on each side in the width direction of the front end of the fixed bracket 23, and they are coaxial with each other. Also, in this example, the outer column 17 is supported by the displacement bracket 24 so as to be able to swing up and down about the tilt shaft 28.

[0045] As shown in Figures 2 to 5, the steering unit 3 of this example is equipped with an electric tilt actuator 29 that is assembled so as to span between the displacement bracket 24 and the outer column 17. The tilt actuator 29 is capable of swinging the outer column 17 in the up and down direction relative to the displacement bracket 24 around a tilt shaft 28.

[0046] To adjust the longitudinal position of the steering wheel 2, the front telescopic actuator 26 is driven to displace the displacement bracket 24 relative to the fixed bracket 23 in the longitudinal direction, thereby displacing the outer column 17 relative to the front inner column 18 in the longitudinal direction, and / or the rear telescopic actuator 27 is driven to displace the rear inner column 19 relative to the outer column 17 in the longitudinal direction. In this way, the overall length of the steering column 9 and the overall length of the steering shaft 10 are extended or contracted, thereby adjusting the longitudinal position of the steering wheel 2.

[0047] To adjust the vertical position of the steering wheel 2, the tilt actuator 29 is driven to swing the outer column 17 up and down around the tilt shaft 28 relative to the displacement bracket 24. This causes the steering column 9 and steering shaft 10 to swing up and down around the tilt shaft 28, thereby adjusting the vertical position of the steering wheel 2.

[0048] The present invention can also be applied to steering devices that do not have a telescoping function and / or a tilting function. Furthermore, the specific structure for realizing the telescoping function and the tilting function can be a structure different from that of this example, such as various conventionally known structures. These structures also include a structure for manually adjusting the fore-aft position or the up-down position of the steering wheel.

[0049] 2, 4, 6, and 7, the gear housing 11 has a recess 34 at the upper end (top surface) of the outer circumferential surface, which is located radially inward from portions located on both circumferential sides and has a deepest portion P in a portion in the front-to-rear direction. The recess 34 is a portion for avoiding interference with an in-vehicle device 35, such as a head-up display device, which is arranged above the gear housing 11.

[0050] In this example, as shown in Figures 6 and 7, the gear housing 11 includes a front housing 30 and a rear housing 31. The front housing 30 houses the reducer 14 inside and has, at its rear end, an annular front mating surface 32 facing rearward. The rear housing 31 has, at its front end, an annular rear mating surface 33 that abuts against the front mating surface 32. In this example, the recess 34 is provided in the upper end of the outer circumferential surface of the gear housing 11, in a range in the front-rear direction that includes the same position in the front-rear direction as the abutment portion between the front mating surface 32 and the rear mating surface. In this example, the torque sensor 13 is housed inside the rear housing 31.

[0051] In this example, the recess 34 is located in the middle in the front-rear direction of the upper end of the outer peripheral surface of the gear housing 11. In this example, the front-rear range Wa of the recess 34 at the upper end of the outer peripheral surface of the gear housing 11 partially overlaps with the front-rear range Wb in which the upper end of the reducer 14 is located. In this example, the upper end of the worm wheel 37 corresponds to the upper end of the reducer in the present invention.

[0052] When implementing the present invention, the front-rear direction range Wa of the recess at the upper end of the outer peripheral surface of the gear housing may be set to a range different from that in this example. When implementing the present invention, the front-rear direction dimension of the front-rear direction range Wa of the recess can be set arbitrarily, but it is preferable to ensure that it is greater than 2 mm.

[0053] The deepest part P of the recess 34 is located rearward of the rear end edge of the upper end of the reducer 14, i.e., the rear end edge of the front-rear range Wb. More specifically, in this example, the deepest part P of the recess 34 is located at the same position in the front-rear direction as the contact point between the front mating surface 32 and the rear mating surface 33.

[0054] When implementing the present invention, the front-to-rear position of the deepest part of the recess at the upper end of the outer peripheral surface of the gear housing can be set to a different front-to-rear position from that in this example, as long as the thickness of the minimum thickness part of the part where the recess is present can be ensured to be at least the required amount (the minimum amount that satisfies the strength requirements).When implementing the present invention, under conditions where the thickness of the minimum thickness part of the part where the recess is present can be ensured to be at least the required amount, the radial depth dp of the deepest part P of the recess can be set as desired, but it is preferable to ensure that it is greater than 1 mm.

[0055] In this example, the recess 34 has a shape in which its depth increases linearly from both ends in the front-rear direction toward the position of the deepest part P in the front-rear direction.

[0056] However, when implementing the present invention, the shape of the recess may be any shape, and may be different from that of this example. For example, the recess may be shaped so that its depth curves downward from both ends in the front-rear direction toward the position of the deepest part P in the front-rear direction.

[0057] In this example, the reducer 14 housed inside the front housing 30 is a worm reducer formed by meshing a worm 36 with a worm wheel 37. When implementing the present invention, the reducer housed inside the front housing may be a reducer other than a worm reducer, such as a reducer formed by combining multiple spur gears, helical gears, friction rollers, etc.

[0058] 7 to 10, the front housing 30 includes a wheel receiving portion 38 that receives the worm wheel 37 therein and a worm receiving portion 39 that receives the worm 36 therein. In this example, the front housing 30 is made of thermoplastic resin or a light alloy such as an aluminum alloy.

[0059] The wheel accommodating section 38 has a cylindrical wheel tube portion 40 arranged around the worm wheel 37, a circular wheel bottom portion 41 extending radially inward from the front end of the wheel tube portion 40, and a substantially cylindrical support tube portion 42 connected to the radially inner end of the wheel bottom portion 41. In this example, the front portion of the support tube portion 42 protrudes forward beyond the front side surface of the wheel bottom portion 41.

[0060] The wheel tubular portion 40 has a front recess 43 that constitutes the front portion of the recess 34 at the upper end of the outer circumferential surface, in a portion from the middle in the front-rear direction to the rear end. In this example, the front recess 43 is formed by a flat surface that is inclined radially inward from the front to the rear.

[0061] The wheel tubular portion 40 has, at its rear end surface, an annular front mating surface 32 centered on the central axis of the wheel tubular portion 40. The front mating surface 32 is formed by a plane perpendicular to the central axis of the wheel tubular portion 40.

[0062] The wheel tubular portion 40 has a front mating surface 44 on the inner peripheral surface of the rear end portion. In this example, the front mating surface 44 has a protruding flat surface 45 at its upper end, which is a circumferential portion located radially inside the front recess 43, and protrudes radially inward more than the portions located on both sides in the circumferential direction. In this example, the portion of the front mating surface 44 other than the protruding flat surface 45 is formed by a cylindrical surface. The protruding flat surface 45 is formed by a flat surface parallel to the central axis of the wheel tubular portion 40.

[0063] As shown in FIG. 11(a), the structure of this example includes a protruding flat portion 45 on the upper end of the front mating surface 44z. Compared to the comparative example shown in FIG. 11(b), in which the upper end of the front mating surface 44z does not include a protruding flat portion and the entire circumference of the front mating surface 44z is a cylindrical surface, the thickness of the upper end (portion X), which is the circumferential portion of the rear end of the wheel tubular portion 40 where the front recess 43 is located, can be made larger. That is, it is easy to ensure a thickness of the upper end (portion X) greater than the required amount. In the structure of this example, the worm wheel 37 is positioned inside a portion of the wheel tubular portion 40 that is located forward of the front mating surface 44 that includes the protruding flat portion 45, as shown by the imaginary line (chain double-dashed line) in FIG. 11(a). The inner diameter of this portion is larger than the inscribed circle diameter of the front fitting surface 44 having the protruding flat portion 45, and a sufficient gap is secured over the entire circumference between the inner peripheral surface of this portion and the outer peripheral surface of the worm wheel 37. In order to place the worm wheel 37 inside this portion, during assembly, the worm wheel 37 must be inserted axially from the rear opening of the wheel cylindrical portion 40 and passed axially inside the front fitting surface 44 having the protruding flat portion 45. When implementing the present invention, to facilitate this passage operation, it is preferable to restrict the amount of radial inward protrusion of the protruding flat portion 45 so that the gap Ca between the worm wheel 37 and the protruding flat portion 45, which is required for this passage, can be secured to be 0.5 mm or more.

[0064] The worm accommodating portion 39 is configured to be generally cylindrical as a whole. The worm accommodating portion 39 is integrally connected to the radially outer end of a circumferential portion of the wheel accommodating portion 38 that is offset from the upper end. The central axis of the worm accommodating portion 39 is disposed at a skewed position with respect to the central axis of the wheel accommodating portion 38. The internal space of the worm accommodating portion 39 communicates with the internal space of the wheel accommodating portion 38. In this example, the worm accommodating portion 39 has a motor mounting flange 46 that extends radially outward at one axial end.

[0065] In this example, the front housing 30 further includes front coupling portions 47 that protrude radially outward from multiple circumferential locations. More specifically, in this example, the front housing 30 further includes front coupling portions 47 that protrude radially outward from multiple circumferential locations (three locations in the illustrated example) of the rear end of the wheel tubular portion 40, excluding the upper end. These front coupling portions 47 are used to couple the front housing 30 and the rear housing 31 to each other. In this example, the rear surfaces of these front coupling portions 47 are formed by a flat surface that exists in the same imaginary plane as the front mating surface 32. In this example, these front coupling portions 47 have coupling holes 48 that penetrate them in the front-to-rear direction.

[0066] In this example, each of the front joints 47 is disposed below the upper edge (point Q1 in FIG. 9) of the recess 34. In other words, each of the front joints 47 is disposed below a horizontal line α1 passing through point Q1 in FIG. 9.

[0067] In this example, as shown in Figures 7 and 12 to 14, the rear housing 31 includes a substantially cylindrical sensor tube portion 49 that is arranged around the torque sensor 13, and a substantially annular support wall portion 50 that extends radially inward from the front end of the sensor tube portion 49.

[0068] The sensor cylinder 49 has a rear recess 51 at the middle of the upper end of the outer circumferential surface in the front-to-rear direction, which constitutes the rear portion of the recess 34. In this example, the rear recess 51 is formed of a flat surface that is inclined radially inward from the rear side to the front side.

[0069] The sensor cylindrical portion 49 has an annular rear mating surface 33 centered on the central axis of the sensor cylindrical portion 49 in a portion adjacent to the front side of the rear recess 51 in the front-rear direction. The rear mating surface 33 is formed by a plane perpendicular to the central axis of the sensor cylindrical portion 49.

[0070] The sensor tube portion 49 has a rear mating surface 52 on the outer peripheral surface of its front end portion, which mates with the front mating surface 44. The rear mating surface 52 extends forward from the radially inner end of the rear mating surface 33. In other words, the rear mating surface 33 is provided in a portion adjacent to the rear side of the rear mating surface 52. In this example, the rear mating surface 52 has a retracted flat portion 53 at its upper end portion, which is retracted radially inward from portions located on both circumferential sides. The retracted flat portion 53 is a portion that engages with the protruding flat portion 45 of the front mating surface 44 when the front mating surface 44 and the rear mating surface 52 are mated. In this example, the retracted flat portion 53 is formed by a flat surface parallel to the central axis of the sensor tube portion 49. The portion of the rear mating surface 52 other than the retracted flat portion 53 is formed by a cylindrical surface. That is, in this example, the front mating surface 44 and the rear mating surface 52 are configured to be non-circularly mated with each other.

[0071] In this example, the rear housing 31 has a rear-facing annular front mating surface 71 on the rear end surface of the sensor tubular portion 49, which is the rear end portion. The front mating surface 71 is formed by a plane that is perpendicular to the central axis of the sensor tubular portion 49. The rear housing 31 has a front fitting surface 72 on the inner circumferential surface of the rear end portion, which is the inner circumferential surface of the rear end portion of the sensor tubular portion 49.

[0072] In this example, the rear housing 31 further includes rear coupling portions 54 that protrude radially outward from multiple circumferential locations. More specifically, in this example, the rear housing 31 further includes rear coupling portions 54 that protrude radially outward from multiple circumferential locations (three locations in the illustrated example) on the front end of the sensor tubular portion 49. These rear coupling portions 54 are disposed at circumferential positions that align with the front coupling portions 47 of the front housing 30. In this example, the front surfaces of these front coupling portions 47 are formed by a flat surface that exists in the same imaginary plane as the rear mating surface 33. These front coupling portions 47 have coupling holes 55 that penetrate them in the front-to-rear direction.

[0073] In this example, each of the rear joints 54 is disposed below the upper edge (point Q2 in FIG. 13) of the recess 34. In other words, each of the rear joints 54 is disposed below a horizontal line α2 passing through point Q2 in FIG. 13.

[0074] In this example, when the front housing 30 and the rear housing 31 are assembled, the front mating surface 44 and the rear mating surface 52 are fitted together, and the front mating surface 32 and the rear mating surface 33 abut against each other. In particular, in this example, the protruding flat surface 45 of the front mating surface 44 and the retracted flat surface 53 of the rear mating surface 52 engage with each other, i.e., the front mating surface 44 and the rear mating surface 52 are fitted together non-circularly, thereby achieving a desired positional relationship between the front housing 30 and the rear housing 31 in the circumferential direction. Furthermore, in this example, the front housing 30 and the rear housing 31 are fixed together by bolts 56 inserted through joining holes 48 of the front housing 30 and threaded into joining holes 55 of the rear housing 31.

[0075] In this example, the gear housing 11 further includes an annular rear bracket 57. In this example, the rear bracket 57 has a cylindrical tubular portion 73 and an annular side plate portion 74 that extends radially outward from the front end of the tubular portion 73. The rear bracket 57 has an annular rear mating surface 75 that abuts against the front mating surface 71 on the front surface of the radially outer end of the side plate portion 74, which is the front end portion. The rear bracket 57 has a rear mating surface 76 on the outer circumferential surface of the front end that mates with the front mating surface 72.

[0076] In this example, when the rear housing 31 and the rear bracket 57 are combined, the front mating surface 72 and the rear mating surface 76 are mated with each other, and the front mating surface 71 and the rear mating surface 75 are in contact with each other. Furthermore, in this state, the rear housing 31 and the rear bracket 57 are coupled and fixed to each other with bolts 77.

[0077] In this example, the gear housing 11 is fixed to the front end of the steering column 9 by fitting the cylindrical portion 73 of the rear bracket 57 into the front end of the front inner column 18 and fixing it thereto.

[0078] In this example, both widthwise side portions of the rear housing 31 of the gear housing 11 are swingably supported by tilt shafts 28 on both widthwise sides. In this example, the central axis L1 of the tilt shaft 28 (see FIGS. 3, 4, and 7) is located rearward of the recessed portion 34 of the gear housing 11 in the front-rear direction, and is located at the same position as the central axis L2 (= the central axis of the output shaft 12) of the steering column 9 in the up-down direction. However, when implementing the present invention, it is preferable that the central axis L1 of the tilt shaft 28 be located at a front-rear direction position included in the front-rear direction range Wa in which the recessed portion 34 is located, in order to minimize the amount of swinging displacement of the recessed portion 34 when the gear housing 11 is swung around the tilt shaft 28, thereby enabling the on-vehicle device 35 (see FIG. 7) to be positioned closer to the surface of the recessed portion 34. From the same viewpoint, it is preferable that the central axis L1 of the tilt shaft 28 be located above the central axis L2 of the steering column 9 in the vertical direction, that is, closer to the recess 34 than the central axis L2 in the vertical direction.

[0079] In this example, the output shaft 12 includes a front output shaft 58 disposed on the front side, a rear output shaft 59 disposed on the rear side, and a torsion bar 60 connecting the front output shaft 58 and the rear output shaft 59. In this example, the rear end of the rear output shaft 59 is connected to the front end of the front shaft 20 using a cylindrical coupling member 61, thereby connecting the output shaft 12 to the front end of the steering shaft 10. That is, in this example, the output shaft 12 is connected to the front end of the steering shaft 10 via the coupling member 61.

[0080] In this example, the front output shaft 58 is rotatably supported by rolling bearings 62a and 62b with respect to the support cylinder portion 42 of the front housing 30 and the support wall portion 50 of the rear housing 31. The rear output shaft 59 is rotatably supported by the rear bracket 57 with a rolling bearing 62c.

[0081] As shown in FIG. 7, the torque sensor 13 is disposed inside the rear housing 31 and around the rear output shaft 59.

[0082] In this example, the electric motor 15 is fixedly coupled to the motor mounting flange 46 of the worm accommodating portion 39. Rotation of the motor output shaft (not shown) of the electric motor 15 is transmitted to the steering shaft 10 via the worm 36, the worm wheel 37, the output shaft 12, and the coupling member 61.

[0083] In this example, the worm 36 is rotatably supported by a rolling bearing 63 inside the worm housing portion 39, as shown in Figure 7. The worm 36 has worm teeth 64 on the outer peripheral surface of an axially intermediate portion. The worm 36 is connected to the motor output shaft of the electric motor 15, and can be rotated by the electric motor 15.

[0084] 7, the worm wheel 37 has wheel teeth 65 on its outer circumferential surface that mesh with the worm teeth 64, and is rotatably supported inside the wheel accommodating portion 38. For this reason, in this example, the worm wheel 37 is fitted and fixed to the outside of a portion of the front output shaft 58 that is located between the two rolling bearings 62a, 62b. The worm teeth 64 of the worm 36 mesh with a circumferential portion of the wheel teeth 65 of the worm wheel 37 that is off the upper end, specifically a lower portion.

[0085] According to the steering device 1 of this example, it is possible to secure a large installation space for the in-vehicle device 35 that is placed above the gear housing 11 that is fixed to the front end of the steering column 9, and it is also easy to secure a sufficient thickness for the portion of the gear housing 11 that is located above the reducer 14.

[0086] That is, the steering device 1 of this example has a recess 34 at the upper end of the outer circumferential surface of the gear housing 11 to avoid interference with the in-vehicle device 35. Therefore, the presence of the recess 34 makes it possible to secure a large installation space for the in-vehicle device 35.

[0087] In particular, in this example, the longitudinal range Wa of the recess 34 is secured wide enough to partially overlap the longitudinal range Wb in which the reducer 14 is disposed. This provides an advantageous structure from the viewpoint of securing a wide installation space for the in-vehicle device 35.

[0088] The recess 34 has a deepest part P in a portion in the front-to-rear direction. The deepest part P is the part where the thickness of the upper end of the gear housing 11 is reduced the most. In this regard, in this example, the deepest part P is located rearward of the rear edge of the upper end of the reducer 14. This makes it easy to ensure the thickness of the part of the gear housing 11 located above the reducer 14.

[0089] In particular, in this example, the deepest part P of the recess 34 is located at the same position in the front-to-rear direction as the contact part between the front mating surface 32 and the rear mating surface 33. Therefore, the shape of the front recess 43 can be simplified compared to a structure in which the deepest part P is located on the outer peripheral surface of the front housing, i.e., a structure in which the deepest part P is located in the front recess. Similarly, the shape of the rear recess 51 can be simplified compared to a structure in which the deepest part P is located on the outer peripheral surface of the rear housing, i.e., a structure in which the deepest part P is located in the rear recess.

[0090] Furthermore, in this example, each of the front joints 47 and the rear joints 54 is disposed below the upper edge (point Q1 in FIG. 9, point Q2 in FIG. 13) of the recess 34. This makes it possible to prevent the in-vehicle device 35 from interfering with each of the front joints 47 and the rear joints 54.

[0091] In this example, the front joint 47 located on the right side of the upper part in Fig. 9 is disposed below the upper edge (point Q1) of the recess 34, but protrudes upward from the deepest part P of the recess 34, in other words, protrudes upward from the horizontal line β1 that is tangent to the deepest part P of the recess 34. The remaining front joints 47, i.e., the front joint 47 located on the left side of the upper part in Fig. 9 and the front joints 47 located on the lower part, are disposed below the deepest part P (horizontal line β1) of the recess 34, in other words, do not protrude upward from the deepest part P (horizontal line β1) of the recess 34.

[0092] In this example, the rear joint 54 located on the left side of the upper part in Fig. 13 is disposed below the upper edge (point Q2) of the recess 34, but protrudes upward from the deepest part P of the recess 34, in other words, protrudes upward from the horizontal line β2 that is tangent to the deepest part P of the recess 34. The remaining rear joints 54, i.e., the rear joint 54 located on the right side of the upper part in Fig. 13 and the rear joints 54 located at the lower part, are disposed below the deepest part P (horizontal line β2) of the recess 34, in other words, do not protrude upward from the deepest part P (horizontal line β2) of the recess 34.

[0093] When the present invention is implemented, the front joint 47 located on the upper right side in Fig. 9 and the rear joint 54 located on the upper left side in Fig. 13 can also be arranged so as not to protrude above the deepest part P (horizontal lines β1, β2) of the recess 34, as shown by the imaginary two-dot chain lines. In this way, it is possible to make it more difficult for the in-vehicle device 35 to interfere with each of the multiple front joints 47 and rear joints 54.

[0094] [Example 2] A second embodiment of the present invention will be described with reference to FIGS.

[0095] In this example, the central axis L1 of the tilt shaft 28, which supports the gear housing 11a to be able to swing relative to the vehicle body, is located at the same position in the front-to-rear direction as the abutment portion between the front mating surface 32 and the rear mating surface 33. More specifically, the central axis L1 of the tilt shaft 28 is located at a position that passes through the upper end of the abutment portion between the front mating surface 32 and the rear mating surface 33, i.e., the deepest portion P of the recess 34. According to the structure of this example, the amount of swinging displacement of the recess 34 when the gear housing 11a is swung around the tilt shaft 28 can be kept small. Therefore, the on-vehicle device 35 can be disposed closer to the surface of the recess 34, thereby ensuring a larger installation space for the on-vehicle device 35. The other configurations, functions, and effects are the same as those of the first example.

[0096] [Example 3] A third embodiment of the present invention will be described with reference to FIGS.

[0097] In this example, the recess 34a at the upper end of the outer peripheral surface of the gear housing 11b is located in a front-rear range Wa that includes the same front-rear position as the abutment portion between the front mating surface 71 of the rear housing 31a and the rear mating surface 75 of the rear bracket 57a. In this example, the front-rear range Wa of the recess 34a is located rearward of the front-rear range Wb in which the upper end of the reducer 14 is disposed and the abutment portion between the front mating surface 32 of the front housing 30a and the rear mating surface 33 of the rear housing 31a.

[0098] In this example, the recess 34a has a shape in which its depth increases linearly from the front end toward the front-to-rear position of the contact point between the front mating surface 71 and the rear mating surface 75, and the depth does not change from the front-to-rear position of the contact point toward the rear end. That is, in this example, the deepest part P of the recess 34a is present in an axial range Wp corresponding to the rear end of the front-to-rear range Wa, whose front end is at the same front-to-rear position as the contact point between the front mating surface 71 and the rear mating surface 75.

[0099] In this example, the recess 34a is formed by combining a front recess 43a provided at the upper end of the outer peripheral surface of the rear housing 31a and a rear recess 51a provided at the upper end of the outer peripheral surface of the side plate portion 74a of the rear bracket 57a. The front recess 43a is formed by a flat surface that slopes radially inward from the front to the rear. The rear recess 51a is formed by a flat surface that is parallel to the central axis of the rear bracket 57a.

[0100] In this example, the front mating surface 44a of the front housing 30a and the rear mating surface 52a of the rear housing 31a, which are fitted together, are formed of cylindrical surfaces over their entire peripheries.

[0101] In this example, the front mating surface 72a of the rear housing 31a and the rear mating surface 76a of the rear bracket 57a, which fit together, have an overhanging flat surface 45a at their upper end, which is a circumferential portion located radially inward of the front recess 43a, that overhangs radially inward relative to the portions located on both circumferential sides. The rear mating surface 76a has, at its upper end, a retracted flat surface 53a that is retracted radially inward relative to the portions located on both circumferential sides and that engages with the overhanging flat surface 45a.

[0102] In this example, the presence of the protruding flat surface 45a facilitates ensuring a sufficient thickness at the upper end of the rear end of the rear housing 31a, where the front recess 43a is located. Furthermore, the protruding flat surface 45a of the front mating surface 72a and the retreating flat surface 53a of the rear mating surface 76a engage with each other. That is, the front mating surface 72a and the rear mating surface 76a engage with each other in a non-circular manner, thereby achieving a desired circumferential positional relationship between the rear housing 31a and the rear bracket 57a. In FIG. 18 , the area surrounding the torque sensor 13, specifically the diagonally gridded area, indicates an area where metal parts must not enter (hereinafter referred to as a metal prohibited area) to prevent noise from entering the torque sensor 13. In this example, the deepest portion P of the recess 34a is located rearward of the metal prohibited area, making it easy to ensure a sufficient thickness at the portion of the rear housing 31a located above the metal prohibited area. The other configurations and effects are the same as those of the first example.

[0103] [Example 4] A fourth embodiment of the present invention will be described with reference to FIGS.

[0104] In this example, the deepest portion P of the recess 34az is located at the rear edge of the front-rear range Wa of the recess 34az. Therefore, in this example, the rear recess 51az provided at the upper end of the outer peripheral surface of the side plate portion 74az of the rear bracket 57az is configured as a plane that slopes radially inward from the front to the rear. In this example, the rear recess 51az is located on the same imaginary plane as the front recess 43a.

[0105] Compared to the structure of the third example, the structure of this example makes it possible to more effectively avoid interference with the in-vehicle device 35 due to the recess 34az. The other configurations and effects are the same as those of the third example.

[0106] [Example 5] A fifth embodiment of the present invention will be described with reference to FIGS.

[0107] In this example, the gear housing 11c is formed by combining a front housing 30b and a rear housing 31b.

[0108] In this example, the torque sensor 13 and the reducer 14 are accommodated inside the rear housing 31b. To this end, in this example, the rear housing 31b includes a substantially cylindrical tubular portion 78 that accommodates the torque sensor 13a inside, a wheel accommodating portion 38a that is connected to the front end of the tubular portion 78 and accommodates the worm wheel 37 inside, and a worm accommodating portion 39a that is connected to one location in the circumferential direction of the wheel accommodating portion 38a and accommodates the worm 36 inside. In this example, the wheel accommodating portion 38a includes a cylindrical wheel tubular portion 40a and a circular wheel bottom portion 41a that extends radially inward from the rear end of the wheel tubular portion 40a. The radially inner end of the wheel bottom portion 41a is connected to the front end of the tubular portion 78.

[0109] The rear housing 31b has a front-facing annular rear mating surface 33a on the front end surface of the wheel cylindrical portion 40a, which is the front end portion. The rear housing 31b has a rear fitting surface 79 on the inner circumferential surface of the front end portion. In this example, the rear end portion of the cylindrical portion 78 is fitted and fixed within the front end portion of the front inner column 18 (see FIG. 6).

[0110] In this example, the front housing 30b is generally annular, and has an annular front mating surface 32a that abuts against the rear mating surface 33a on the rear side surface of the radially outer end, which is the rear end. The front housing 30b has a front mating surface 80 on the outer circumferential surface of the rear end that mates with the rear mating surface 79.

[0111] In this example, the recess 34b at the upper end of the outer peripheral surface of the gear housing 11c is located in a front-rear range Wa that includes the same front-rear position as the contact portion between the front mating surface 32a and the rear mating surface 33a. In this example, the rear side of the recess 34b in the front-rear range Wa overlaps with the front side of the front-rear range Wb in which the upper end of the reducer 14 is located.

[0112] In this example, the recess 34b has a shape in which its depth increases linearly from the rear end toward the longitudinal position of the contact point between the front mating surface 32a and the rear mating surface 33a, and the depth does not change from the longitudinal position of the contact point toward the front end. That is, in this example, the deepest part P of the recess 34b is located in an axial range Wp corresponding to the front end of the longitudinal range Wa, whose rear end is at the same longitudinal position as the contact point between the front mating surface 32a and the rear mating surface 33a. Therefore, the deepest part P of the recess 34b is located forward of the longitudinal range Wb in which the upper end of the reducer 14 is located.

[0113] In this example, the recess 34b is formed by combining a rear recess 51b provided at the upper end of the outer peripheral surface of the rear housing 31b and a front recess 43b provided at the upper end of the outer peripheral surface of the front housing 30b. The rear recess 51b is formed by a flat surface that slopes radially inward from the rear side to the front side. The front recess 43b is formed by a flat surface that is parallel to the central axis of the front housing 30b.

[0114] In this example, of the rear mating surface 79 of the rear housing 31b and the front mating surface 80 of the front housing 30b that fit together, the rear mating surface 79 has, at its upper end, a circumferential portion located radially inward of the rear recess 51b, a protruding flat surface 45b that protrudes radially inward beyond the portions located on both circumferential sides. The front mating surface 80 has, at its upper end, a retracted flat surface 53b that is retracted radially inward beyond the portions located on both circumferential sides and that engages with the protruding flat surface 45b.

[0115] In this example, the presence of the protruding flat surface 45b makes it easier to ensure the thickness of the upper end of the front end of the rear housing 31b, where the rear recess 51b is located. Furthermore, the protruding flat surface 45b of the rear mating surface 79 and the retracted flat surface 53b of the front mating surface 80 engage with each other. In other words, the rear mating surface 79 and the front mating surface 80 are non-circularly fitted with each other, so that the rear housing 31b and the front housing 30b have a desired positional relationship relative to each other in the circumferential direction. Other configurations, functions, and effects are similar to those of the first example.

[0116] [Example 6] A sixth embodiment of the present invention will be described with reference to FIGS. 27 and 28. FIG.

[0117] In this example, the deepest portion P of the recess 34bz is located at the front edge of the front-rear range Wa of the recess 34bz. For this reason, in this example, the front recess 43bz provided at the upper end of the outer peripheral surface of the front housing 30bz is configured as a plane that slopes radially inward from the rear to the front. In this example, the front recess 43bz is located on the same imaginary plane as the rear recess 51b.

[0118] Compared to the structure of the fifth example, the structure of this example makes it possible to more effectively avoid interference with the in-vehicle device 35 due to the recess 34bz. The other configurations and effects are the same as those of the fifth example.

[0119] [Example 7] A seventh embodiment of the present invention will be described with reference to FIG.

[0120] In this example, the steering device of the present invention is applied to an electric power steering device in which the steering wheel and steered wheels are mechanically connected.

[0121] The steering device 1a of this example includes a steering unit 3 having the same structure as that of the first example, a pair of universal joints 66a and 66b, an intermediate shaft 67, a steering gear unit 68, and a pair of tie rods 69.

[0122] The front end of the output shaft 12 of the steering unit 3 is connected to a pinion shaft 70 of a steering gear unit 68 via a rear universal joint 66a, an intermediate shaft 67, and a front universal joint 66b. Therefore, when the driver turns the steering wheel 2, the rotation of the steering wheel 2 is transmitted to the pinion shaft 70 via the steering shaft 10, the output shaft 12, the rear universal joint 66a, the intermediate shaft 67, and the front universal joint 66b. The rotation of the pinion shaft 70 is converted into linear motion of a rack shaft (not shown) of the steering gear unit 68 that meshes with the pinion shaft 70. As a result, a pair of tie rods 69 are pushed and pulled, and a steering angle corresponding to the amount of rotation of the steering wheel 2 is applied to the left and right steered wheels.

[0123] In this example, in the steering unit 3, a torque sensor 13 (see FIG. 7) detects the direction and magnitude of torque applied to the steering shaft 10 from the steering wheel 2. An electric motor 15 (see FIG. 5) rotationally drives a worm 36 (see FIG. 7) based on the detection signal from the torque sensor 13, a vehicle speed signal output from a vehicle speed sensor incorporated in the transmission, and the like, thereby applying auxiliary power to the output shaft 12 via a worm wheel 37 (see FIG. 7). As a result, the force required by the driver to rotate the steering wheel 2 is reduced. The other configurations and effects are the same as those of the first example.

[0124] The present invention can be implemented by appropriately combining the configurations of the above-described embodiments within the scope of not causing any contradiction. [Explanation of symbols]

[0125] 1, 1a Steering device 2 steering wheels 3 Steering unit 4 steering wheels 5. Steering unit 6. Control device 7 Steering actuator 8 tie rods 9. Steering column 10. Steering shaft 11, 11a, 11b, 11c gear housing 12 Output shaft 13, 13a Torque sensor 14 Reducer 15 Electric motor 16 Column support device 17 Outer Column 18 Front inner column 19 Rear inner column 20 Front shaft 21 Rear shaft 22a, 22b Rolling bearings 23 Fixing bracket 24 Displacement Bracket 25 Linear guide 26 Front telescopic actuator 27 Rear telescopic actuator 28 Tilt Axis 29 Tilt actuator 30, 30a, 30b, 30bz Front housing 31, 31a, 31b Rear housing 32, 32a Front mating surface 33, 33a Rear mating surface 34, 34a, 34az, 34b, 34bz recesses 35 Onboard equipment 36 Warm 37 Worm Wheel 38, 38a Wheel housing 39, 39a Worm housing 40, 40a Wheel tube 41, 41a Wheel bottom 42 Support cylinder part 43, 43a, 43b, 43bz Front recess 44, 44a Front mating surface 45, 45a, 45b Overhanging plane part 46 Motor mounting flange 47 Anterior joint 48 Binding hole 49 Sensor tube 50 Support wall section 51, 51a, 51az, 51b Rear recess 52, 52a Rear mating surface 53, 53a, 53b Evacuation plane section 54 Posterior joint 55 Binding hole 56 volts 57, 57a, 57az rear bracket 58 Front output shaft 59 Rear output shaft 60 Torsion bar 61 Joint member 62a, 62b, 62c Rolling bearings 63 Rolling bearings 64 worm teeth 65 wheel teeth 66a, 66b Universal joint 67 Intermediate shaft 68 Steering gear unit 69 tie rod 70 Pinion shaft 71 Front mating surface 72, 72a Front mating surface 73 Cylindrical part 74, 74a, 74az side plate part 75 Rear mating surface 76, 76a Rear mating surface 77 volts 78 Cylindrical part 79 Rear mating surface 80 Front mating surface

Claims

1. a steering column supported by a vehicle body; a gear housing fixed to a front end of the steering column; a reducer accommodated inside the gear housing, the gear housing has a recess at an upper end of an outer circumferential surface, the recess being located radially inward relative to portions located on both circumferential sides and having a deepest portion in a portion in the front-rear direction, The deepest part is located rearward or forward of the upper end of the reducer. Steering device.

2. the gear housing accommodates the reducer therein and includes a front housing having an annular front mating surface facing rearward at a rear end thereof, and a rear housing having an annular rear mating surface abutting against the front mating surface at a front end thereof, the recess is provided in an upper end portion of the outer peripheral surface of the gear housing in a range in the front-rear direction that includes the same position in the front-rear direction as a contact portion between the front mating surface and the rear mating surface, The deepest part is located rearward of the upper end of the reducer. The steering device according to claim 1 .

3. The steering device according to claim 2 , wherein the deepest portion is located at the same position in the front-to-rear direction as a contact portion between the front mating surface and the rear mating surface.

4. the front housing has a front fitting surface on an inner peripheral surface of a rear end portion thereof, the rear housing has a rear mating surface on an outer peripheral surface of a front end portion thereof, the rear mating surface mating with the front mating surface; the front fitting surface has, at an upper end portion thereof which is a circumferential portion located radially inward of the recess, a protruding flat portion that protrudes radially inward further than portions located on both sides in the circumferential direction, the rear fitting surface has, at an upper end thereof, a retracted flat surface portion that is retracted radially inward from portions located on both circumferential sides and that engages with the protruding flat surface portion; The steering device according to claim 2 or 3.

5. a torque sensor disposed inside the gear housing; the gear housing includes: a front housing that houses the reducer therein; a rear housing that is disposed adjacent to the rear side of the front housing and houses the torque sensor therein, and has an annular front mating surface facing rearward at its rear end; and a rear bracket that has an annular rear mating surface at its front end that abuts against the front mating surface, the recess is provided in an upper end portion of the outer peripheral surface of the gear housing in a range in the front-rear direction that includes the same position in the front-rear direction as a contact portion between the front mating surface and the rear mating surface, The deepest part is located rearward of the upper end of the reducer. The steering device according to claim 1 .

6. The steering device according to claim 5 , wherein the deepest portion is located at the same position in the front-to-rear direction as a contact portion between the front mating surface and the rear mating surface and / or is located rearward of the contact portion.

7. the rear housing has a front mating surface on an inner peripheral surface of a rear end portion, the rear bracket has a rear mating surface on an outer peripheral surface of a front end portion thereof, the rear mating surface mating with the front mating surface; the front fitting surface has, at an upper end portion thereof which is a circumferential portion located radially inward of the recess, a protruding flat portion that protrudes radially inward further than portions located on both sides in the circumferential direction, the rear fitting surface has, at an upper end thereof, a retracted flat surface portion that is retracted radially inward from portions located on both circumferential sides and that engages with the protruding flat surface portion; 7. A steering device according to claim 5 or 6.

8. the gear housing accommodates the reducer therein and includes a rear housing having, at a front end thereof, an annular rear mating surface facing forward, and a front housing having, at a rear end thereof, an annular front mating surface abutting against the rear mating surface; the recess is provided in an upper end portion of the outer peripheral surface of the gear housing in a range in the front-rear direction that includes the same position in the front-rear direction as a contact portion between the front mating surface and the rear mating surface, The deepest part is located forward of the upper end of the reducer. The steering device according to claim 1 .

9. The steering device according to claim 8 , wherein the deepest portion is located at the same position in the front-to-rear direction as a contact portion between the front mating surface and the rear mating surface and / or located forward of the contact portion.

10. the rear housing has a rear mating surface on an inner peripheral surface of a front end portion, the front housing has a front mating surface on an outer peripheral surface of a rear end portion thereof, the front mating surface mating with the rear mating surface; the rear fitting surface has, at an upper end portion which is a circumferential portion located radially inward of the recess, a protruding flat portion which protrudes radially inward further than portions located on both sides in the circumferential direction, the front fitting surface has, at an upper end thereof, a retracted flat surface portion that is retracted radially inward from portions located on both circumferential sides and that engages with the protruding flat surface portion; 10. A steering device according to claim 8 or 9.

11. a tilt shaft disposed in the width direction of the vehicle body and supporting the gear housing so that the gear housing can swing relative to the vehicle body; a central axis of the tilt shaft is located at a position in the front-rear direction included in a range in the front-rear direction in which the recess is located; A steering device according to any one of claims 1 to 10.

12. a central axis of the tilt shaft is located at the same position in the front-rear direction as a contact portion between the front mating surface and the rear mating surface; A steering device according to claim 11 which cites any one of claims 2 to 10.

13. the front housing has front joining portions, which protrude radially outward at a plurality of circumferential locations and are used to join the front housing and the rear housing together, the rear housing has rear joining portions, which protrude radially outward at a plurality of circumferential locations and are used to join the front housing and the rear housing together, The front joint portion and the rear joint portion are each disposed below an upper edge of the recessed portion. A steering device according to any one of claims 2 to 10, claim 11 which relies on any one of claims 2 to 10, and claim 12.

14. Each of the front joint portion and the rear joint portion is not positioned above a deepest portion of the recessed portion. A steering device according to claim 13.

15. The steering device according to any one of claims 1 to 14, which is used as a steer-by-wire steering device.

16. The steering device according to any one of claims 1 to 14, which is used as an electric power steering device.

Images