JP7748264B2 - Steering device - Google Patents

Description

The present invention relates to a steering device for applying a steering angle to the steered wheels of an automobile.

Generally, automotive steering systems are configured to transmit the rotation of the steering wheel operated by the driver to the pinion shaft of the steering gear unit via a steering shaft, intermediate shaft, etc., and then 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.

In the field of steering devices, electric power steering devices that apply auxiliary power to the steering force transmission path to reduce the force required to operate the steering wheel are becoming increasingly common. Electric power steering devices are broadly categorized by the location at which the auxiliary power is applied. For example, a column-assist electric power steering device that applies auxiliary power to the steering shaft includes a steering column supported on the vehicle body, a steering shaft rotatably supported inside the steering column and with the steering wheel attached to its rear end, a gear housing fixed to the front end of the steering column, a torque sensor and reducer housed inside the gear housing, and an electric motor supported by the gear housing. The torque sensor detects the direction and magnitude of the torque applied to the steering shaft from the steering wheel. The electric motor is driven and controlled using detection signals from the torque sensor, etc., and applies auxiliary power to the steering shaft via the reducer. As a result, the force required by the driver to operate the steering wheel is reduced.

Meanwhile, in recent years, there has been progress in the development of steer-by-wire steering devices that 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 device, the steering unit detects the steering wheel's steering angle using a steering angle sensor, and based on the detection signal from the steering angle sensor, the steering unit's actuator 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 this end, the steering unit includes a steering column supported on the vehicle body, a steering shaft rotatably supported inside the steering column and with 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 driven and controlled using detection signals from the torque sensor and steering angle sensor, and applies a reaction force to the steering wheel via the reducer and steering shaft.

In recent years, an increasing number of vehicles have been equipped with head-up displays (HUDs), which allow the driver to check information such as driving speed without having to take their eyes off the road. HUDs project information such as driving speed from below onto the portion of the vehicle's windshield that is located in front of the driver's face. For this reason, head-up displays are often positioned above the steering system, as described in, for example, DE 10 2018 202 562 A1 (Patent Document 1) and Japanese Patent Publication No. 6,377,501 (Patent Document 2).

DE102018202562A1 Patent No. 6377501

The specific placement of the head-up display device above the steering system will be determined based on its relationship to other surrounding components, but one proposal under consideration is to place the head-up display device above the gear housing that makes up the steering system. In this case, the design must ensure that the gear housing and the head-up display device do not interfere with each other.

When designing in this way, it is possible to consider, for example, providing a recess at the upper end of the outer peripheral surface of the gear housing to avoid interference with the head-up display device. By providing such a recess, it is possible to ensure a large space for installing the head-up display device.

However, in the radial direction around 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 for the portion of the gear housing located above the reducer.

The objective of the present invention is to provide a steering device that ensures ample installation space for on-board devices located above a gear housing fixed to the front end of the steering column, and that makes it easy to ensure sufficient thickness for the portion of the gear housing located above the reducer.

A steering device according to one aspect of the present invention comprises a steering column supported on a vehicle body, a gear housing fixed to the front end of the steering column, and a reducer housed inside the gear housing.

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

In the steering device of the 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 a front-to-rear range that includes the same front-to-rear position as the abutment point between the front mating surface and the rear mating surface on the upper end of the outer peripheral surface of the gear housing, and the deepest part is located rearward of the upper end of the reducer.

The steering device of the first aspect of the present invention can be configured so that the deepest portion is located in the same fore-and-aft direction as the abutment portion between the front mating surface and the rear mating surface.

In a steering device according to a first aspect of the present invention, the front housing has a front mating surface on the inner peripheral surface of its rear end, and the rear housing has a rear mating surface on the outer peripheral surface of its front end that mates with the front mating surface. The front mating surface has, at its upper end, a circumferential portion located radially inside the recess, a protruding flat portion that protrudes radially inward beyond the 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 the portions located on both circumferential sides and that engages with the protruding flat portion.

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 disposed in a longitudinal range that includes the same longitudinal position as the abutment point between the front mating surface and the rear mating surface on the upper end of the outer peripheral surface of the gear housing, and the deepest portion is located rearward of the upper end of the reducer.

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 point between the front mating surface and the rear mating surface and/or is located rearward of the abutment point.

In a steering device according to a second aspect of the present invention, the rear housing has a front mating surface on the inner peripheral surface of the rear end, and the rear bracket 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 has, at its upper end, a circumferential portion located radially inside the recess, a protruding flat portion that protrudes radially inward beyond the 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 the portions located on both circumferential sides and that engages with the protruding flat portion.

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 a front-to-rear range that includes the same front-to-rear position as the abutment point between the front mating surface and the rear mating surface on the upper end of the outer peripheral surface of the gear housing, and the deepest portion is located forward of the upper end of the reducer.

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 longitudinal position as the contact point between the front mating surface and the rear mating surface and/or further forward than the contact point.

In a third aspect of the steering device of the present invention, the rear housing has a rear mating surface on the inner peripheral surface of its front end, and the front housing has a front mating surface on the outer peripheral surface of its rear end that matings with the rear mating surface, and the rear mating surface has a protruding flat surface at its upper end, which is a circumferential portion located radially inside the recess, that protrudes radially inward beyond the 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 beyond the portions located on both circumferential sides and that engages with the protruding flat surface.

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 this steering device, 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.

One aspect of the steering device of the present invention has a tilt shaft that is arranged in the width direction of the vehicle body and supports the gear housing so that it can swing relative to the vehicle body, and the central axis of the tilt shaft is located in a longitudinal position that is included in the longitudinal range in which the recess is located.

In one aspect of the steering device of the present invention, the central axis of the tilt shaft is located in the same longitudinal position as the abutment point between the front mating surface and the rear mating surface.

In one aspect of the steering device of the present invention, the front housing has front joint portions that protrude radially outward at multiple circumferential locations and are used to join the front housing and the rear housing together, and the rear housing has rear joint portions that protrude radially outward at multiple circumferential locations and are used to join the front housing and the rear housing together, with each of the front joint portions and the rear joint portions being positioned below the upper edge of the recess.

In one aspect of the steering device of the present invention, the front joint portion and the rear joint portion are not positioned above the deepest part of the recess.

One aspect of the steering device of the present invention is used as a steer-by-wire steering device.

The steering device of one embodiment of the present invention is used as an electric power steering device.

The steering device of one aspect of the present invention allows for ample installation space for on-board devices located above the gear housing fixed to the front end of the steering column, and also makes it easy to ensure sufficient thickness for the portion of the gear housing located above the reducer.

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

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

One aspect of the steering device of the present invention, including the steering device of this example, is a steering device in which an in-vehicle device such as a head-up display device is placed above a gear housing fixed to the front end of the 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-to-rear direction means the front-to-rear direction of the vehicle, the up-to-down direction means the up-to-down direction of the vehicle, and the width direction means the width direction of the vehicle.

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

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

As shown in Figures 2 to 7 (particularly Figure 6), the steering unit 3 includes a steering column 9, a gear housing 11, and a reducer 14.

The steering column 9 is cylindrical and supported by the vehicle body. The steering column 9 rotatably supports the steering shaft 10 on its inner side. The steering wheel 2 (see Figure 1) is attached to the rear end of the steering shaft 10. The gear housing 11 is fixed to the front end of the steering column 9. The gear housing 11 rotatably supports the output shaft 12 on its inner side and houses a torque sensor 13 and a reduction gear 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 reduction gear 14 transmits the output torque of the electric motor 15 (see Figure 5) supported by the gear housing 11 to the output shaft 12. This applies a steering reaction force to the steering wheel 2 via the output shaft 12 and the steering shaft 10.

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

The steering unit 3 in this example has a telescopic function that allows the fore-aft position of the steering wheel 2 to be adjusted. To achieve this, the steering column 9 and steering shaft 10 are configured so that their overall lengths can be extended or retracted.

Specifically, the steering column 9 comprises an outer column 17 located in the middle in the longitudinal direction, a front inner column 18 fitted into the front side of the outer column 17 to allow relative longitudinal displacement, and a rear inner column 19 fitted into the rear side of the outer column 17 to allow relative longitudinal displacement. The gear housing 11 is fixed to the front end of the front inner column 18.

The steering shaft 10 consists of a front shaft 20 located at the front and a rear shaft 21 located at the rear, which are spline-engaged to enable torque transmission and relative axial displacement. The rear shaft 21 is rotatably supported inside the rear inner column 19 using multiple (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.

The column support device 16 includes a fixed bracket 23 fixed to the vehicle body, a displacement bracket 24 positioned below the fixed bracket 23, and a linear guide 25 (see Figure 5) assembled between the lower surface of the fixed bracket 23 and the upper surface of the displacement bracket 24, allowing the displacement bracket 24 to be displaced relative to the fixed bracket 23 in the fore-and-aft direction. The outer column 17 is supported by the displacement bracket 24.

As shown in Figures 2 to 6, the steering unit 3 in this example is equipped with an electric front telescopic actuator 26 that is assembled so as to span between the fixed bracket 23 and the displacement bracket 24. The front telescopic actuator 26 can displace the displacement bracket 24 in the fore-and-aft direction relative to the fixed bracket 23.

As shown in Figures 2 to 6, the steering unit 3 in this example is equipped with an electric rear telescopic actuator 27 that is assembled so as to span 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 longitudinal direction.

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

As shown in Figures 2 to 5, the steering unit 3 in 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 can swing the outer column 17 up and down relative to the displacement bracket 24 around the tilt axis 28.

To adjust the fore-and-aft 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 fore-and-aft direction, thereby displacing the outer column 17 relative to the front inner column 18 in the fore-and-aft 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 fore-and-aft direction. This extends or contracts the overall length of the steering column 9 and the overall length of the steering shaft 10, thereby adjusting the fore-and-aft position of the steering wheel 2.

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 axis 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 axis 28, thereby adjusting the vertical position of the steering wheel 2.

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

As shown in Figures 2, 4, 6, and 7, the gear housing 11 has a recess 34 at the upper end (top surface) of its outer circumferential surface, which is located radially inward relative to the 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 located above the gear housing 11 to avoid interference with an on-board device 35, such as a head-up display device.

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-to-rear direction that includes the same position in the front-to-rear direction as the abutment point 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.

In this example, the recess 34 is located in the middle of the upper end of the outer peripheral surface of the gear housing 11 in the front-to-rear direction. In this example, the front-to-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-to-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 this invention.

When implementing this invention, the longitudinal range Wa of the recess at the upper end of the outer peripheral surface of the gear housing can be set to a different longitudinal range than in this example. When implementing this invention, the longitudinal dimension of the longitudinal range Wa of the recess can be set as desired, but it is preferable to ensure that it is greater than 2 mm.

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

When implementing this invention, the longitudinal 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 longitudinal position from that in this example, as long as the minimum thickness of the part where the recess is present can be ensured to be at least the required amount (the minimum amount that meets the strength requirements). When implementing this invention, the radial depth dp of the deepest part P of the recess can be set as desired, provided that the minimum thickness of the part where the recess is present can be ensured to be at least the required amount, but it is preferable to ensure that it is greater than 1 mm.

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

However, when implementing the present invention, the shape of the recess is arbitrary and can be different from that of this example. For example, the recess can be shaped so that its depth curves upward from both front-to-rear ends toward the front-to-rear position of the deepest part P.

In this example, the reducer 14 housed inside the front housing 30 is a worm reducer consisting of a worm 36 and a worm wheel 37 meshed together. When implementing the present invention, the reducer housed inside the front housing can also be a reducer other than a worm reducer, such as a reducer made up of a combination of multiple spur gears, helical gears, friction rollers, etc.

In this example, as shown in Figures 7 to 10, the front housing 30 has a wheel accommodating portion 38 that accommodates the worm wheel 37 inside, and a worm accommodating portion 39 that accommodates the worm 36 inside. In this example, the front housing 30 is made of thermoplastic resin or a light alloy such as an aluminum alloy.

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

The wheel tubular portion 40 has a front recess 43 that forms the front portion of the recess 34 at the upper end of the outer peripheral surface, from the middle in the fore-and-aft direction to the rear end. In this example, the front recess 43 is formed by a flat surface that slopes radially inward from the front to the rear.

The wheel tubular portion 40 has an annular front mating surface 32 at its rear end face, 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.

The wheel tubular portion 40 has a front mating surface 44 on the inner peripheral surface of the rear end. 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 inward of the front recess 43, and which protrudes radially inward further 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 as a cylindrical surface. The protruding flat surface 45 is formed as a flat surface parallel to the central axis of the wheel tubular portion 40.

As shown in FIG. 11(a), the structure of this example includes a protruding flat surface 45 on the upper end of the front mating surface 44. Compared to the comparative example structure shown in FIG. 11(b), in which the upper end of the front mating surface 44z does not include a protruding flat surface 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. In other words, it is easier to ensure a thickness of this upper end (portion X) greater than the required amount. In the structure of this example, the worm wheel 37 is positioned inside the portion of the wheel tubular portion 40 that is forward of the front mating surface 44 that includes the protruding flat surface 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 mating surface 44, which includes the protruding flat surface 45, and a sufficient gap is maintained around the entire circumference between the inner peripheral surface of this portion and the outer peripheral surface of the worm wheel 37. To position the worm wheel 37 inside this portion, during assembly, the worm wheel 37 must be inserted axially through the rear opening of the wheel cylindrical portion 40 and pass axially inside the front mating surface 44, which includes the protruding flat surface 45. When implementing the present invention, to facilitate this passage, it is preferable to limit the radial inward protrusion of the protruding flat surface 45 so that the gap Ca between the worm wheel 37 and the protruding flat surface 45, which is required for this passage, is maintained to be 0.5 mm or more.

The worm accommodating portion 39 is configured to be approximately cylindrical overall. It is integrally connected to the radially outer end of the 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 positioned at a skew relative to the central axis of the wheel accommodating portion 38. The internal space of the worm accommodating portion 39 is connected to the internal space of the wheel accommodating portion 38. In this example, the worm accommodating portion 39 has a motor mounting flange 46 at one axial end that extends radially outward.

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 fore-and-aft direction.

In this example, each of the multiple front joints 47 is positioned below the upper edge of the recess 34 (point Q1 in Figure 9). In other words, each of the multiple front joints 47 is positioned below the horizontal line α1 that passes through point Q1 in Figure 9.

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.

The sensor cylinder 49 has a rear recess 51 that forms the rear portion of the recess 34 at the middle of the upper end of the outer peripheral surface in the front-to-rear direction. In this example, the rear recess 51 is formed by a flat surface that slopes radially inward from the rear to the front.

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

The sensor tube portion 49 has a rear mating surface 52 on the outer peripheral surface of its front end, 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 recessed flat surface 53 at its upper end, which is recessed radially inward from the portions located on both circumferential sides. The recessed flat surface 53 is a portion that engages with the protruding flat surface 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 recessed flat surface 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 recessed flat surface 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 fit together in a non-circular manner.

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 its rear end. The front mating surface 71 is formed by a plane perpendicular to the central axis of the sensor tubular portion 49. The rear housing 31 has a front mating surface 72 on the inner circumferential surface of the rear end, which is the inner circumferential surface of the rear end of the sensor tubular portion 49.

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 positioned in 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.

In this example, each of the multiple rear joints 54 is positioned below the upper edge of the recess 34 (point Q2 in Figure 13). In other words, each of the multiple rear joints 54 is positioned below the horizontal line α2 that passes through point Q2 in Figure 13.

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 mated with each other, 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 recessed flat surface 53 of the rear mating surface 52 engage with each other. In other words, the front mating surface 44 and the rear mating surface 52 are non-circularly mated with each other, thereby achieving the desired circumferential positional relationship between the front housing 30 and the rear housing 31. Furthermore, in this state, the front housing 30 and the rear housing 31 are fixed together by a bolt 56 inserted through the connecting hole 48 of the front housing 30 and threaded into the connecting hole 55 of the rear housing 31.

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 a circular ring-shaped 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 side surface of the radially outer end of the side plate portion 74, which is its front end. The rear bracket 57 has a rear mating surface 76 on the outer peripheral surface of its front end that mates with the front mating surface 72.

In this example, when the rear housing 31 and rear bracket 57 are assembled, 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 abutted against each other. Furthermore, in this state, the rear housing 31 and rear bracket 57 are fastened together by bolts 77.

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.

In this example, both widthwise sides of the rear housing 31 of the gear housing 11 are pivotally 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 recess 34 of the gear housing 11 in the front-to-rear direction and is aligned with the central axis L2 of the steering column 9 (= the central axis of the output shaft 12) in the up-down direction. However, when implementing the present invention, it is preferable to position the central axis L1 of the tilt shaft 28 in a front-to-rear direction within the front-to-rear range Wa in which the recess 34 is located, in order to minimize the amount of pivotal displacement of the recess 34 when the gear housing 11 is pivoted around the tilt shaft 28, thereby enabling the on-board device 35 (see FIG. 7) to be positioned closer to the surface of the recess 34. From a similar perspective, 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, i.e., closer to the recess 34 than the central axis L2 in the vertical direction.

In this example, the output shaft 12 includes a front output shaft 58 located at the front, a rear output shaft 59 located at the rear, 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. In other words, in this example, the output shaft 12 is connected to the front end of the steering shaft 10 via the coupling member 61.

In this example, the front output shaft 58 is rotatably supported by rolling bearings 62a and 62b relative to the support tube 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 rolling bearing 62c relative to the rear bracket 57.

As shown in Figure 7, the torque sensor 13 is arranged inside the rear housing 31 around the rear output shaft 59.

In this example, the electric motor 15 is fixedly coupled to the motor mounting flange 46 of the worm housing 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, worm wheel 37, output shaft 12, and coupling member 61.

In this example, as shown in Figure 7, the worm 36 is rotatably supported inside the worm housing 39 by a rolling bearing 63. The worm 36 has worm teeth 64 on the outer peripheral surface of the axially middle 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.

As shown in Figure 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 front output shaft 58 at a portion located between the two rolling bearings 62a, 62b. The worm teeth 64 of the worm 36 mesh with the circumferential portion of the wheel teeth 65 of the worm wheel 37 that is off the upper end, specifically the lower portion.

The steering device 1 of this example ensures ample installation space for the on-board device 35 located above the gear housing 11, which is fixed to the front end of the steering column 9, and also makes it easy to ensure sufficient thickness for the portion of the gear housing 11 located above the reducer 14.

In other words, the steering device 1 of this example has a recess 34 at the upper end of the outer peripheral 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 ensure a large installation space for the in-vehicle device 35.

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

The recess 34 has a deepest point P in a portion in the front-to-rear direction. The deepest point 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 point P is located rearward of the rear edge of the upper end of the reducer 14. This makes it easier to ensure the thickness of the part of the gear housing 11 located above the reducer 14.

In particular, in this example, the deepest part P of the recess 34 is located in the same longitudinal position as the abutment point 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.

Furthermore, in this example, each of the multiple front joints 47 and rear joints 54 is positioned below the upper edge of the recess 34 (point Q1 in Figure 9, point Q2 in Figure 13). This makes it less likely that the in-vehicle device 35 will interfere with each of the multiple front joints 47 and rear joints 54.

In this example, the front joint 47 located on the right side of the upper part in Figure 9 is positioned below the upper edge (point Q1) of the recess 34, but protrudes above the deepest part P of the recess 34; in other words, it protrudes above 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 Figure 9 and the front joints 47 located at the lower part, are positioned below the deepest part P (horizontal line β1) of the recess 34; in other words, they do not protrude above the deepest part P (horizontal line β1) of the recess 34.

In this example, the rear joint 54 located on the left side of the upper part in Figure 13 is positioned below the upper edge (point Q2) of the recess 34, but protrudes above the deepest part P of the recess 34; in other words, it protrudes above 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 Figure 13 and the rear joints 54 located at the lower part, are positioned below the deepest part P (horizontal line β2) of the recess 34; in other words, they do not protrude above the deepest part P (horizontal line β2) of the recess 34.

When implementing the present invention, the front joint 47 located on the upper right in Figure 9 and the rear joint 54 located on the upper left in Figure 13 can also be positioned so that they do not protrude above the deepest part P (horizontal lines β1, β2) of the recess 34, as shown by the imaginary two-dot chain lines. This makes it possible to make it less likely that the on-board device 35 will interfere with each of the multiple front joints 47 and rear joints 54.

[Second Example]
A second embodiment of the present invention will be described with reference to FIGS. 15 and 16. FIG.

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 longitudinal position 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 the upper end of the abutment portion between the front mating surface 32 and the rear mating surface 33, i.e., at a position passing through the deepest portion P of the recess 34. This structure of this example minimizes the amount of swing displacement of the recess 34 when the gear housing 11a is swung around the tilt shaft 28. This allows the on-board device 35 to be positioned closer to the surface of the recess 34, thereby ensuring a larger installation space for the on-board device 35. Other configurations, functions, and effects are the same as those of the first example.

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

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-to-rear range Wa that includes the same front-to-rear position as the abutment point 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-to-rear range Wa of the recess 34a is located rearward of the front-to-rear range Wb in which the upper end of the reducer 14 is located, and the abutment point between the front mating surface 32 of the front housing 30a and the rear mating surface 33 of the rear housing 31a.

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

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.

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 fit together, are cylindrical surfaces along their entire periphery.

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

In this example, the presence of the protruding flat surface 45a facilitates ensuring the thickness of 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 recessed 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 the desired circumferential positional relationship between the rear housing 31a and the rear bracket 57a. In Figure 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 the 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 easier to ensure the thickness of the portion of the rear housing 31a located above the metal prohibited area. Other configurations and effects are the same as those of the first example.

[Fourth Example]
A fourth embodiment of the present invention will be described with reference to FIGS. 21 and 22. FIG.

In this example, the deepest part P of the recess 34az is located at the rear edge of the front-to-rear range Wa of the recess 34az. For this reason, 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.

Compared to the structure of the third example, the structure of this example allows the recess 34az to more effectively avoid interference with the in-vehicle device 35. Other configurations and effects are the same as those of the third example.

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

In this example, the gear housing 11c is made up of a front housing 30b and a rear housing 31b.

In this example, the torque sensor 13 and the reducer 14 are housed inside the rear housing 31b. To this end, in this example, the rear housing 31b includes a substantially cylindrical tubular portion 78 that houses the torque sensor 13a inside, a wheel accommodating portion 38a that is connected to the front end of the tubular portion 78 and houses the worm wheel 37 inside, and a worm accommodating portion 39a that is connected to one location circumferentially of the wheel accommodating portion 38a and houses 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.

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

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

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

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 abutment 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 abutment point toward the front end. That is, in this example, the deepest part P of the recess 34b is located in the axial range Wp corresponding to the front end of the longitudinal range Wa, whose rear end is at the same longitudinal position as the abutment 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.

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 to the front. The front recess 43b is formed by a flat surface that is parallel to the central axis of the front housing 30b.

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

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 recessed 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 engage with each other in a non-circular manner, thereby achieving the desired positional relationship between the rear housing 31b and the front housing 30b in the circumferential direction. Other configurations, functions, and effects are the same as those of the first example.

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

In this example, the deepest part 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.

Compared to the structure of the fifth example, the structure of this example allows the recess 34bz to more effectively avoid interference with the in-vehicle device 35. Other configurations and effects are the same as those of the fifth example.

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

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.

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

The front end of the output shaft 12 of the steering unit 3 is connected to the pinion shaft 70 of the steering gear unit 68 via the rear universal joint 66a, the intermediate shaft 67, and the front universal joint 66b. Therefore, when the driver rotates 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 the rack shaft (not shown) of the steering gear unit 68, which is meshed with the pinion shaft 70. As a result, a pair of tie rods 69 are pushed and pulled, imparting a steering angle to the left and right steered wheels according to the amount of rotation of the steering wheel 2.

In this example, in the steering unit 3, the torque sensor 13 (see Figure 7) detects the direction and magnitude of the torque applied to the steering shaft 10 from the steering wheel 2. The electric motor 15 (see Figure 5) applies auxiliary power to the output shaft 12 via the worm wheel 37 (see Figure 7) by driving the worm 36 (see Figure 7) to rotate based on the detection signal from the torque sensor 13, a vehicle speed signal output from a vehicle speed sensor built into the transmission, and the like. 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.

The present invention can be implemented by appropriately combining the configurations of the above-mentioned embodiments to the extent that no contradictions arise.

REFERENCE SIGNS LIST 1, 1a Steering device 2 Steering wheel 3 Steering unit 4 Steering wheel 5 Steering unit 6 Control device 7 Steering actuator 8 Tie rod 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 bearing 23 Fixing bracket 24 Displacement bracket 25 Linear guide 26 Front telescopic actuator 27 Rear telescopic actuator 28 Tilt shaft 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 Recess 35 On-vehicle device 36 Worm 37 Worm wheel 38, 38a Wheel accommodating portion 39, 39a Worm accommodating portion 40, 40a Wheel tubular portion 41, 41a Wheel bottom portion 42 Support tubular portion 43, 43a, 43b, 43bz Front recess 44, 44a Front fitting surface 45, 45a, 45b Projecting flat portion 46 Motor mounting flange 47 Front coupling portion 48 Coupling hole 49 Sensor tubular portion 50 Support wall portion 51, 51a, 51az, 51b Rear recess 52, 52a Rear fitting surface 53, 53a, 53b Retreat flat portion 54 Rear coupling portion 55 Coupling hole 56 Bolt 57, 57a, 57az Rear bracket 58 Front output shaft 59 Rear output shaft 60 Torsion bar 61 Joint member 62a, 62b, 62c Rolling bearing 63 Rolling bearing 64 Worm tooth 65 Wheel tooth 66a, 66b Universal joint 67 Intermediate shaft 68 Steering gear unit 69 Tie rod 70 Pinion shaft 71 Front mating surface 72, 72a Front fitting surface 73 Cylindrical portion 74, 74a, 74az Side plate portion 75 Rear mating surface 76, 76a Rear fitting surface 77 Bolt 78 Cylindrical portion 79 Rear fitting surface 80 Front mating surface

Claims (16)

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 peripheral 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. the gear housing accommodates the reducer therein and includes a front housing having, at a rear end thereof, an annular front mating surface facing rearward, and a rear housing having, at a front end thereof, an annular rear mating surface abutting against the front mating surface;
the recess is provided in a front-rear direction range including the same front-rear direction position as a contact portion between the front mating surface and the rear mating surface, in an upper end portion of the outer peripheral surface of the gear housing,
The deepest part is located rearward of the upper end of the reducer.
The steering device according to claim 1 . A steering device as described in claim 2, wherein the deepest portion is located at the same longitudinal position as the abutment portion between the front mating surface and the rear mating surface. 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. 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 a front-rear direction range including the same front-rear direction position as a contact portion between the front mating surface and the rear mating surface, in an upper end portion of the outer peripheral surface of the gear housing,
The deepest part is located rearward of the upper end of the reducer.
The steering device according to claim 1 . A steering device as described in claim 5, wherein the deepest portion is located at the same longitudinal position as and/or rearward of the contact point between the front mating surface and the rear mating surface. 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. 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 a front-rear direction range including the same front-rear direction position as a contact portion between the front mating surface and the rear mating surface, in an upper end portion of the outer peripheral surface of the gear housing,
The deepest part is located forward of the upper end of the reducer.
The steering device according to claim 1 . A steering device as described in claim 8, wherein the deepest portion is located at the same longitudinal position as and/or forward of the contact point between the front mating surface and the rear mating surface. 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 sides in the circumferential direction and that engages with the protruding flat surface portion.
10. A steering device according to claim 8 or 9. a tilt shaft disposed in the width direction of the vehicle body and supporting the gear housing so as to be swingable 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. 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. 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.
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. The steering device according to any one of claims 1 to 14, used as a steer-by-wire steering device. The steering device according to any one of claims 1 to 14, used as an electric power steering device.