JP7650064B2 - Steering gear - Google Patents

Description

This disclosure relates to a steering device.

In a device that uses an electrically operated motor as an actuator to perform a desired operation, if the motor becomes inoperable, the device will no longer operate as a device that is driven by the motor's driving force. If the operation of the device stops in this way, other operations may be affected, so some conventional devices that use motors have measures in place to deal with the situation when the motor becomes inoperable. For example, in the motor for an electric brake device described in Patent Documents 1 and 2, the end of the motor's rotating shaft is processed so that it can be engaged with a jig, and if the motor becomes inoperable, the end of the motor's rotating shaft can be engaged with the jig, allowing the rotating shaft to be manually rotated with the jig and the device to be manually operated.

JP 2002-39240 A JP 2001-234958 A

In recent years, an increasing number of steering devices mounted on vehicles use motors to perform arbitrary operations. An example of an operation using a motor in a steering device is a telescopic mechanism that moves the steering wheel in the forward and backward directions. In the case of such a telescopic mechanism, if a malfunction occurs in the motor used in the telescopic mechanism and the motor cannot be operated, the telescopic mechanism will no longer be able to use the driving force of the motor to move the steering wheel in the forward and backward directions.

However, when a driver is seated in the driver's seat inside the vehicle, the range within which the driver can reach the steering device is limited, and depending on the position of the motor, it may be difficult to manually rotate the motor's rotating shaft as in Patent Documents 1 and 2. For this reason, in telescopic mechanisms and the like that operate using the driving force generated by a motor, there is room for improvement in terms of ensuring operations that are performed using the driving force generated by the motor, such as the operation of moving the steering wheel in the forward and backward directions, even when a malfunction occurs in the motor and it becomes impossible to operate the motor.

The present disclosure has been made in consideration of the above, and aims to provide a steering device that can perform operations that were previously performed using the driving force generated by a motor, even when the motor cannot be operated.

The steering device disclosed herein comprises a steering column having a steering shaft with a steering wheel attached to one end thereof and rotated by torque input from the steering wheel, a first column member, and a second column member combined with the first column member to enable relative axial displacement therebetween, the steering column rotatably supporting the steering shaft, and a telescopic actuator for displacing the second column member in the axial direction relative to the first column member. The telescopic actuator comprises a telescopic motor as a drive source, a worm wheel that rotates by the drive force from the telescopic motor, and a worm wheel that is inserted into an insertion hole formed in the worm wheel to rotate the worm wheel. The screw shaft has a screw that rotates with the screw, and a nut that displaces in the axial direction of the screw shaft as the screw shaft rotates and is supported and fixed to the second column member by a nut support member. The screw shaft has an engagement portion formed at one end with which an operating member that inputs a rotational torque to the screw shaft engages. The screw shaft is inserted into the insertion hole via a torque limiter that is formed in an annular shape and transmits the rotation of the worm wheel from the worm wheel to the screw shaft by frictional force. When a rotational torque of a predetermined magnitude or more acts between the worm wheel and the screw shaft, the torque limiter slides against the worm wheel or the screw shaft, thereby allowing the relative rotation between the worm wheel and the screw shaft.

According to this configuration, when the telescopic motor cannot be operated due to a malfunction of the telescopic motor, the operating member is engaged with the engagement portion of the screw shaft, and a rotational torque is applied from the operating member to the screw shaft, causing slippage in the torque limiter and allowing the screw shaft to rotate relative to the worm wheel. This allows the nut screwed onto the screw shaft to be displaced in the axial direction of the screw shaft as the screw shaft rotates, and the second column member to which the nut is supported and fixed by the nut support member can be displaced in the axial direction relative to the first column member together with the nut. Therefore, even if the telescopic motor cannot be operated, the second column member can be displaced in the axial direction relative to the first column member by rotating the screw shaft using the operating member. As a result, even if the motor cannot be operated, the operation that was performed using the driving force generated by the motor can be performed.

In a preferred embodiment, the threaded shaft is arranged parallel to the steering shaft, and the engagement portion is formed at the end of the threaded shaft on the side where the steering wheel attached to the steering shaft is located.

According to this configuration, the engagement portion of the screw shaft is formed at the end of the screw shaft on the side where the steering wheel attached to the steering shaft is located, so that the operating member can be engaged with the engagement portion from a position closer to the steering wheel. Therefore, when rotating the screw shaft using the operating member, the operating member can be engaged with the engagement portion of the screw shaft, and the screw shaft can be rotated using the operating member. As a result, even if it becomes impossible to operate the motor, the operation that was previously performed using the driving force generated by the motor can be performed.

In a preferred embodiment, the engagement portion is a polygonal hole, and the portion of the operating member that engages with the engagement portion is formed in the same polygonal shape as the engagement portion, and engages with the engagement portion by being inserted into the engagement portion.

According to this configuration, the engagement portion of the screw shaft is a polygonal hole, and the portion of the operating member that engages with the engagement portion is formed in the same polygonal shape as the engagement portion, so the operating member can be inserted into the engagement portion to engage with it. This allows the operating member to be engaged with the engagement portion of the screw shaft in a state in which relative rotation is not possible, and the screw shaft can be rotated using the operating member. Therefore, even if it becomes impossible to operate the motor, the operation that was previously performed using the driving force generated by the motor can be performed.

The steering device disclosed herein has the advantage that, even if the motor cannot be operated, the operation that was previously performed using the driving force generated by the motor can still be performed.

FIG. 1 is a schematic diagram showing a steering system incorporating a steering device according to an embodiment. FIG. 2 is a side view of a steering column device included in the steering device according to the embodiment. FIG. 3 is a perspective view of a steering column device included in the steering device according to the embodiment. FIG. 4 is a perspective view of a steering column device included in the steering device according to the embodiment. FIG. 5 is a view taken along the line AA in FIG. FIG. 6 is a perspective view of the displacement bracket, and is an explanatory diagram of a tilt feed screw device disposed in the swing support bracket portion. FIG. 7 is a cross-sectional view taken along line BB of FIG. FIG. 8 is an exploded perspective view of the lower telescopic actuator. FIG. 9 is an assembled perspective view of the lower telescopic actuator. FIG. 10 is a plan view of the steering column device showing a state in which the column holder is in a forward position and the lower telescopic motor is inoperable. FIG. 11 is a perspective view of the steering column device shown in FIG. FIG. 12 is a side view of the steering column device, showing a state in which the operating member is engaged with the engaging portion of the screw shaft. FIG. 13 is a side view of the steering column device, showing a state in which the column holder is displaced relatively to the fixed bracket by using the operating member.

A detailed description of the form (embodiment) for carrying out the invention will be given with reference to the drawings. The present disclosure is not limited to the contents described in the following embodiment. Furthermore, the components described below include those that a person skilled in the art would easily imagine and those that are substantially the same. Furthermore, the components described below can be combined as appropriate.

[Embodiment]
FIG. 1 is a schematic diagram showing a steering system 120 incorporating a steering device 1 according to an embodiment. The steering device 1 according to this embodiment is incorporated in a steer-by-wire steering system 120. The steer-by-wire steering system 120 is formed by electrically connecting a steering device 1 having a steering wheel 121 and a sensor (not shown) for measuring the steering amount of the steering wheel 121, and a turning device 130 for applying a steering angle to a pair of steering wheels 135. That is, in the steer-by-wire steering system 120, the operation amount of the steering wheel 121 by the driver is measured by the sensor of the steering device 1. Then, based on the output signal of the sensor, an actuator 131 of the turning device 130 is driven to displace a linear shaft such as a rack shaft or a screw shaft arranged in the width direction of the vehicle in the width direction of the vehicle, and a pair of tie rods 132 are pushed and pulled to apply a steering angle to a pair of steering wheels 135.

The steering device 1 according to this embodiment is mounted on a vehicle capable of so-called automatic driving, in which the vehicle drives automatically without the driver's operation based on sensors and map information mounted on the vehicle, vehicle position information obtained by a GPS (Global Positioning System), and a communication device that communicates with external devices such as other vehicles. For this reason, the vehicle on which the steering device 1 is mounted is provided with a driving control unit (not shown) that switches the vehicle's driving control between automatic driving and manual driving, making it possible to switch the vehicle's driving control between automatic driving and manual driving depending on the vehicle's running state and the driver's wishes.

The steering device 1 includes a steering column device 2, a steering shaft 3, and a reaction force imparting device 70. Note that the front-rear direction, up-down direction, and width direction of the steering device 1 refer to the front-rear direction, up-down direction, and width direction of the vehicle when the steering device 1 is attached to the vehicle.

Figure 2 is a side view of the steering column device 2 of the steering device 1 according to the embodiment. Figures 3 and 4 are perspective views of the steering column device 2 of the steering device 1 according to the embodiment. Note that Figure 4 is a view in which the reaction force applying device 70 has been removed. The steering column device 2 includes a steering column 10, a lower telescopic actuator 80, an upper telescopic actuator 90, and a tilt actuator 100.

The steering column 10 includes a fixed bracket 11, a column holder 20, and an upper column 40, and is configured to be extendable and contractable in its entire length. Specifically, the steering column 10 is configured by combining the fixed bracket 11 and the column holder 20 in a manner that allows relative axial displacement, and by combining the column holder 20 and the upper column 40 in a manner that allows relative axial displacement.

The fixed bracket 11 comprises a fixed plate portion 12 and a fixed side bracket portion 15.

The fixing plate portion 12 has a rectangular shape that extends in the front-rear direction when viewed from the top-down direction, and has through holes 13 that penetrate in the up-down direction at two locations in the front-rear direction on each of both widthwise sides. The fixing bracket 11 is supported and fixed to the body (not shown) of the vehicle on which the steering column device 2 is mounted by mounting bolts 14 that are inserted from below into the through holes 13 of the fixing plate portion 12.

The fixed side bracket portion 15 has a generally U-shape when viewed from the front-rear direction, and is fixed to the front end of the fixed plate portion 12. That is, the fixed side bracket portion 15 has a pair of fixed side plate portions 16a, 16b that hang down from both ends in the width direction of the front end of the fixed plate portion 12, and a fixed side connecting portion 17 that connects the lower ends of the fixed side plate portions 16a, 16b. In other words, the fixed side connecting portion 17 is suspended between the lower ends of the pair of fixed side plate portions 16a, 16b.

The column holder 20 comprises a displacement bracket 21 supported to allow relative axial (front-to-back) displacement with respect to the fixed bracket 11, and a lower column 50 supported to allow vertical swinging with respect to the displacement bracket 21.

The displacement bracket 21 comprises a displacement plate portion 22, a pair of hanging plate portions 24a, 24b, and a swing support bracket portion 25.

The displacement plate portion 22 has a rectangular shape that extends in the front-to-rear direction when viewed from the top-to-bottom direction.

The pair of hanging plate sections 24a, 24b hang downward from the ends on both sides of the width of the portion of the displacement plate section 22 that extends from the front to the middle section.

Figure 5 is a view taken along the line A-A in Figure 2. The swing support bracket portion 25 has a generally U-shaped shape when viewed from the front-rear direction, and is fixed to the rear end of the displacement plate portion 22. That is, the swing support bracket portion 25 has a pair of displacement side plate portions 26a, 26b that hang down downward from both ends in the width direction of the rear end of the displacement plate portion 22, and a displacement side connecting portion 27 that connects the lower ends of the pair of displacement side plate portions 26a, 26b.

A linear guide 30 is disposed between the fixed bracket 11 and the column holder 20, and the fixed bracket 11 and the column holder 20 are combined via the linear guide 30 to allow relative axial displacement. The linear guide 30 is disposed between the displacement bracket 21 of the column holder 20 and the fixed bracket 11, and the displacement bracket 21 is supported by the linear guide 30 to allow relative axial displacement with respect to the fixed bracket 11. That is, in this embodiment, the fixed bracket 11 constitutes the first column member, and the column holder 20 constitutes the second column member.

The linear guide 30 comprises a guide rail 31 having a rectangular shape extending in the axial direction (front-rear direction), and a slider 32 having a substantially U-shape when viewed from the axial direction, which is combined with the guide rail 31 so as to be displaceable in the axial direction along the guide rail 31. In this embodiment, the guide rail 31 is fixedly joined to the lower surface of the fixed plate portion 12 of the fixed bracket 11. The slider 32 is fixedly joined to the upper surface of the displacement plate portion 22 of the displacement bracket 21.

The linear guide 30 may be any of a sliding linear guide, a ball circulation linear guide, and a non-circulating roller linear guide. A sliding linear guide is formed by engaging an engagement protrusion formed on a slider with a rail groove formed on a guide rail. A ball circulation linear guide is configured by arranging multiple balls in a load path provided between the guide rail and the slider so that the balls can roll, and a circulation path is provided inside the slider to return the balls that have moved to the end point of the load path due to the relative displacement between the guide rail and the slider to the start point of the load path. A non-circulating roller linear guide is configured by rolling multiple rollers supported rotatably on the slider in rolling contact with the rolling surface formed on the guide rail.

The lower column 50 has a generally cylindrical shape and is supported by the displacement bracket 21 so that it can swing up and down. The lower column 50 has a large diameter section 51 in the front portion, and a small diameter section 52 in the rear portion, the inside diameter of which is smaller than that of the large diameter section 51.

The rear portion of the lower column 50 is supported via a tilt feed screw device 102 (see FIG. 6) constituting the tilt actuator 100 so that it can be displaced in the vertical direction relative to the swing support bracket portion 25 of the displacement bracket 21. In addition, the front portion of the lower column 50 is pivotally supported via an inner column 60 and a housing 71 of a reaction force applying device 70 to a fixed bracket portion 15 of a fixed bracket 11 supported on the vehicle body.

Figure 6 is a perspective view of the displacement bracket 21, and is an explanatory diagram of the tilt feed screw device 102 arranged on the swing support bracket portion 25. The tilt feed screw device 102 constituting the tilt actuator 100 is arranged on the displacement bracket 21. The tilt feed screw device 102 includes a screw shaft 103 having a male thread on its outer circumferential surface, and a nut 105 having a female thread formed on its inner circumferential surface that screws into the male thread of the screw shaft 103, and the nut 105 has a cylindrical pivot shaft portion 104 on its outer circumferential surface.

The screw shaft 103 is rotatably supported via a bearing device 106 on the inside of a groove 28 formed in the displacement side plate portion 26a on one side in the width direction of the swing support bracket portion 25 and a circular hole formed in the displacement side connecting portion 27. In detail, a groove 28 extending in the vertical direction is formed on the inner side surface in the width direction of one of the pair of displacement side plate portions 26a, 26b of the swing support bracket portion 25 of the displacement bracket 21. In addition, a circular hole penetrating in the vertical direction is formed in one side portion in the width direction of the displacement side connecting portion 27 of the swing support bracket portion 25 of the displacement bracket 21, that is, the portion on the side where the displacement side plate portion 26a on which the groove 28 is formed is located. The screw shaft 103 is supported via a bearing device 106 on the inside of the groove 28 formed in this way and the circular hole of the displacement side connecting portion 27.

For example, a radial rolling bearing or a sliding bearing is used as the bearing device 106. In addition, the pivot shaft portion 104 formed on the nut 105 that screws into the male thread portion of the screw shaft 103 is rotatably engaged with a pivot recess formed on the rear portion of the lower column 50, i.e., the outer peripheral surface of the small diameter portion 52 of the lower column 50, and pivots the lower column 50. Therefore, when the screw shaft 103 rotates, the nut 105 is displaced along the screw shaft 103 in the axial direction (up and down direction) of the screw shaft 103 as the screw shaft 103 rotates, and the rear portion of the lower column 50 is displaced up and down relative to the swing support bracket portion 25 of the displacement bracket 21.

The inner column 60 (see FIG. 4) has a flange portion 62 that is bent radially outward from the front end of the inner column 60. The inner column 60 is assembled to the lower column 50 in a manner that allows the lower column 50 to move relative to the axial direction. In other words, the steering column device 2 fits the inner column 60 within the lower column 50 in a manner that allows the lower column 50 to move relative to the axial direction.

The housing 71 of the reaction force applying device 70 is fixed to the flange portion 62 of the inner column 60 by a fixing bolt 64 (see FIG. 4), and is supported and fixed to the inner column 60. The housing 71 is also pivotally supported to the fixed bracket 11 by a pivot bolt 65 that passes through a through hole formed in the fixed side plate portions 16a and 16b of the fixed bracket portion 15.

As a result, when the nut 105 is displaced in the vertical direction as the screw shaft 103 of the tilt feed screw device 102 rotates, the rear portion of the lower column 50 is displaced in the vertical direction relative to the swing support bracket portion 25 of the displacement bracket 21, and the lower column 50 swings in the vertical direction around the pivot bolt 65. In other words, the pivot bolt 65 serves as the swing axis when the lower column 50 swings in the vertical direction.

The upper column 40 has a generally cylindrical shape and is assembled to the column holder 20 so as to be displaceable relative to the column holder 20 in the axial direction. Specifically, the front portion of the upper column 40 is fitted into the small diameter portion 52 of the lower column 50 with a clearance fit. This allows the upper column 40 to be fitted into the lower column 50 so as to be displaceable relative to the lower column 50 in the axial direction.

The lower telescopic actuator 80 has a lower telescopic motor 81, and the lower telescopic motor 81 is used as a drive source to displace the column holder 20 in the axial direction relative to the fixed bracket 11. In this embodiment, the lower telescopic actuator 80 constitutes the telescopic actuator, and the lower telescopic motor 81 constitutes the telescopic motor. The lower telescopic motor 81 is located closer to the steering wheel 121 (see FIG. 1) than the pivot bolt 65, which is the pivot axis when the lower column 50 oscillates, in the axial direction of the steering shaft 3. In other words, the steering wheel 121 can be attached to the steering wheel attachment portion 3a located at the rear end of the steering shaft 3, and the lower telescopic motor 81 is located closer to the steering wheel attachment portion 3a of the steering shaft 3 than the pivot bolt 65 in the axial direction of the steering shaft 3. In other words, the lower telescopic motor 81 is located behind the pivot bolt 65 in the axial direction of the steering shaft 3.

The lower telescopic actuator 80 further includes a lower feed screw device 82 for converting the rotational motion of the output shaft of the lower telescopic motor 81 into linear motion. The lower feed screw device 82 includes a screw shaft 83 having a male thread on its outer circumferential surface and driven to rotate by the lower telescopic motor 81, and a nut 84 having a female thread on its inner circumferential surface that screws into the male thread.

In the steering column device 2 according to this embodiment, the screw shaft 83 is supported so as to be rotatable only relative to the fixed bracket 11, and the nut 84 is supported and fixed to the displacement bracket 21 of the column holder 20. Specifically, the screw shaft 83 is fixed so as to be rotatable only relative to the widthwise outer surface of the fixed side plate portion 16b of the fixed side bracket portion 15 constituting the fixed bracket 11, and the nut 84 is supported and fixed to the widthwise outer surface of the hanging plate portion 24b of the displacement bracket 21.

The lower telescopic motor 81 is supported and fixed to the fixed bracket portion 15, and the rotational driving force generated by the lower telescopic motor 81 can be transmitted to the screw shaft 83 via a reduction mechanism. In this embodiment, a worm reducer is used as the reduction mechanism. The nut 84 can be displaced in the front-rear direction along the screw shaft 83 as the screw shaft 83 is rotated by the rotational driving force transmitted from the lower telescopic motor 81 to the screw shaft 83 via the reduction mechanism. Since the nut 84 is supported and fixed to the hanging plate portion 24b of the displacement bracket 21, the displacement bracket 21 can be displaced in the axial direction of the fixed bracket 11, i.e., in the front-rear direction, relative to the fixed bracket 11 as the nut 84 displaces in the front-rear direction.

Figure 7 is a cross-sectional view taken along line B-B in Figure 5. Figure 8 is an exploded perspective view of the lower telescopic actuator 80. Figure 9 is an assembled perspective view of the lower telescopic actuator 80. To explain the configuration of the lower feed screw device 82 in detail, in this embodiment, the rotational driving force generated by the lower telescopic motor 81 can be transmitted to the screw shaft 83 via the worm reducer, so that one end of the screw shaft 83 is located in the housing 86 in which the worm reducer is arranged. In the housing 86, a worm wheel 87 constituting the worm reducer, a rolling bearing 88 that rotatably supports the screw shaft 83, and a torque limiter 89 interposed between the worm wheel 87 and the screw shaft 83 are arranged.

The housing 86 is attached to the output shaft (not shown) side of the lower telescopic motor 81. More specifically, a screw hole 86a for a fixing bolt 81a is formed on the surface of the housing 86 on which the lower telescopic motor 81 is attached, and the lower telescopic motor 81 is attached to the housing 86 by inserting the fixing bolt 81a through a through hole (not shown) formed in the lower telescopic motor 81 and screwing it into the screw hole 86a. As a result, the lower telescopic motor 81 is attached to the housing 86 with the output shaft, to which a worm (not shown) constituting a worm reducer is attached, inserted into the housing 86. The housing 86 is attached to the fixed side plate portion 16b (see FIG. 2) of the fixed bracket portion 15 (see FIG. 2) of the fixed bracket 11.

The worm wheel 87 is disposed in the housing 86, meshing with a worm attached to the output shaft of the lower telescopic motor 81, and is capable of rotating by the driving force from the lower telescopic motor 81. The worm wheel 87 has an insertion hole 87a formed in the thickness direction in the part toward the center of rotation. The screw shaft 83 has a portion near one end inserted into the insertion hole 87a formed in the worm wheel 87 inside the housing 86, which allows the screw shaft 83 to rotate together with the worm wheel 87.

The rolling bearing 88 is disposed inside the housing 86 on the side opposite the side where the nut 84 is located in the axial direction of the screw shaft 83. The outer peripheral surface side of the rolling bearing 88 is fitted into the housing 86, and the screw shaft 83 passes through the inner peripheral surface side. In this way, the rolling bearing 88 supports the screw shaft 83 so that the screw shaft 83 can rotate freely relative to the housing 86.

The torque limiter 89 is formed in a circular shape with an outer diameter approximately equal to the inner diameter of the insertion hole 87a formed in the worm wheel 87, and an inner diameter approximately equal to the outer diameter of the portion of the screw shaft 83 that is inserted into the insertion hole 87a of the worm wheel 87. The torque limiter 89 is fitted into the insertion hole 87a of the worm wheel 87, and the screw shaft 83 is fitted into the insertion hole 87a and inserted into the torque limiter 89, so that it is inserted into the insertion hole 87a of the worm wheel 87 via the torque limiter 89. The torque limiter 89, which is disposed between the insertion hole 87a of the worm wheel 87 and the screw shaft 83, is capable of transmitting the rotation of the worm wheel 87 from the worm wheel 87 to the screw shaft 83 by frictional force.

In addition, when a rotational torque of a predetermined magnitude or more acts between the worm wheel 87 and the screw shaft 83, the torque limiter 89 slips on the worm wheel 87 or the screw shaft 83, thereby allowing relative rotation between the worm wheel 87 and the screw shaft 83. In other words, the torque limiter 89 is not in a state where relative rotation is prohibited with respect to at least one of the worm wheel 87 and the screw shaft 83, and when a rotational torque of a predetermined magnitude or more acts between the worm wheel 87 and the screw shaft 83, slip occurs. As a result, the torque limiter 89 can allow relative rotation between the worm wheel 87 and the screw shaft 83 when a rotational torque of a predetermined magnitude or more acts. The rotational torque at which slip occurs in the torque limiter 89 is set to, for example, 5 to 10 Nm, and when a rotational torque of this magnitude or more acts, the torque limiter 89 slips and allows relative rotation between the worm wheel 87 and the screw shaft 83. A tolerance ring can also be used as the torque limiter 89.

In this case, the predetermined rotational torque is greater than the rotational torque when the worm wheel 87, which rotates due to the rotational driving force received from the lower telescopic motor 81, transmits the rotational driving force to the screw shaft 83. Therefore, when transmitting the rotational driving force from the worm wheel 87, which rotates due to the rotational driving force received from the lower telescopic motor 81, to the screw shaft 83, the torque limiter 89 can transmit the rotational driving force by frictional force without slippage.

The screw shaft 83, which is inserted into the insertion hole 87a of the worm wheel 87 via the torque limiter 89, is arranged parallel to the steering shaft 3 and extends from the end side that is inserted into the insertion hole 87a of the worm wheel 87 toward the rear side. In other words, the screw shaft 83 extends parallel to the steering shaft 3 from inside the housing 86 in which the worm wheel 87 is installed toward the side where the steering wheel 121 attached to the steering shaft 3 is located.

The nut 84 that screws into the male thread of the screw shaft 83 is capable of being displaced relatively in the axial direction of the screw shaft 83 as the screw shaft 83 rotates, and is supported and fixed to the column holder 20 by a nut support member 85. More specifically, the nut 84 is supported and fixed to the hanging plate portion 24b (see FIG. 3) of the displacement bracket 21 of the column holder 20 by the nut support member 85.

The screw shaft 83 also has an engagement portion 83a formed at one end with which an operating member 110, which is a member that inputs a rotational torque to the screw shaft 83, engages. The engagement portion 83a is formed at the end of the screw shaft 83 on the side where the steering wheel 121 attached to the steering shaft 3 is located, i.e., the rear end of the screw shaft 83. In this embodiment, the engagement portion 83a is formed as a polygonal hole at the end of the screw shaft 83, and specifically, the engagement portion 83a is formed in the shape of a hexagonal hole.

The upper telescopic actuator 90 (see FIG. 4) has an upper telescopic motor 91, and displaces the upper column 40 in the axial direction relative to the column holder 20 using the upper telescopic motor 91 as a drive source. In this embodiment, the upper telescopic actuator 90 further has an upper feed screw device 92 (see FIG. 2) for converting the rotational motion of the output shaft of the upper telescopic motor 91 into linear motion.

The upper feed screw device 92 is equipped with a screw shaft 93 having a male thread on its outer circumferential surface and driven to rotate by the upper telescopic motor 91, and a nut 94 having a female thread on its inner circumferential surface that screws into the male thread.

In this embodiment, the screw shaft 93 is supported so as to be rotatable only relative to the lower column 50 of the column holder 20, and the nut 94 is supported and fixed to the upper column 40. Specifically, the screw shaft 93 is supported so as to be rotatable only relative to the lower surface of the front part of the large diameter portion 51 of the lower column 50, and the nut 94 is supported and fixed to the lower surface of the front part of the upper column 40 by a connecting member 95 consisting of multiple members. In detail, a long hole extending in the axial direction is formed in the lower surface of the lower column 50, and the connecting member 95 is disposed so as to penetrate the long hole formed in the lower column 50. The lower part of the connecting member 95 is connected to the nut 94 located below the lower column 50, and the upper part of the connecting member 95 is connected to the upper column 40 located within the lower column 50. As a result, the connecting member 95 supports and fixes the nut 94 located below the lower column 50 to the upper column 40 located within the lower column 50. Additionally, the upper telescopic motor 91 is supported and fixed to the lower column 50.

The rotational driving force generated by the upper telescopic motor 91 can be transmitted to the screw shaft 93 via a reduction mechanism such as a worm reducer. Therefore, the rotational driving force generated by the upper telescopic motor 91 is transmitted to the screw shaft 93 via the reduction mechanism, and the screw shaft 93 is rotated by the driving force transmitted to the screw shaft 93, so that the nut 94 screwed onto the screw shaft 93 is displaced in the front-rear direction along the screw shaft 93. As a result, the upper column 40 to which the nut 94 is fixed can be displaced in the axial direction of the lower column 50, i.e., in the front-rear direction, relative to the lower column 50, in accordance with the front-rear displacement of the nut 94.

The steering column device 2 configured as above is capable of appropriately displacing the relative position of the steering shaft 3 with respect to the fixed bracket 11 in the front-rear direction by operating the lower telescopic actuator 80 and the upper telescopic actuator 90.

The tilt actuator 100 (see FIG. 4) has a tilt motor 101, which is the driving source for the tilt actuator 100, and a tilt feed screw device 102 (see FIG. 6).

The tilt actuator 100, which is composed of a tilt motor 101 and a tilt feed screw device 102, is capable of swinging the steering shaft 3 around a swing axis that is located at the end of the steering column 10 opposite the end where the steering wheel mounting portion 3a of the steering shaft 3 is located and is perpendicular to the axial direction of the steering shaft 3. In this embodiment, the pivot bolt 65 is used as the swing axis that is the center of swing caused by the tilt actuator 100.

The pivot bolt 65, which is the pivot axis, is located on the end side of the steering column 10 opposite the side where the steering wheel mounting part 3a is located, i.e., on the front end side of the steering column 10, so the tilt actuator 100 including the tilt motor 101 is located in a position rearward of the position of the pivot bolt 65 in the axial direction of the steering shaft 3. In other words, the tilt actuator 100 having the tilt motor 101 is located in the axial direction of the steering shaft 3 closer to the steering wheel 121 (see FIG. 1) than the position of the pivot bolt 65.

The tilt actuator 100 configured as above is capable of transmitting the rotational driving force generated by the tilt motor 101 to the screw shaft 103 (see FIG. 6) of the tilt feed screw device 102 via a speed reduction mechanism such as a worm reducer. Therefore, the rotational driving force generated by the tilt motor 101 is transmitted to the screw shaft 103 of the tilt feed screw device 102 via the speed reduction mechanism, and the screw shaft 103 is rotated by the driving force transmitted to the screw shaft 103, so that the nut 105 (see FIG. 6) screwed onto the screw shaft 103 moves vertically along the screw shaft 103. As a result, the tilt actuator 100 displaces the rear portion of the lower column 50, which is pivotally supported by the pivot shaft portion 104 formed on the nut 105, vertically relative to the displacement bracket 21.

The steering shaft 3 is supported rotatably on the radially inner side of the steering column 10 of the steering column device 2.

The steering shaft 3 has a steering wheel 121 (see FIG. 1) attached to one end, and rotates due to torque input from the steering wheel 121. More specifically, the steering wheel 121 is attached to a steering wheel attachment portion 3a formed at the rear end of the steering shaft 3, and is supported by the steering shaft 3. A reaction force imparting device 70 (see FIG. 2) is connected to the front end of the steering shaft 3 for imparting an operation reaction force to the steering wheel 121. In other words, the reaction force imparting device 70 is disposed on the end side of the steering column 10 opposite the side where the steering wheel 121 attached to the steering shaft 3 is located.

The reaction force applying device 70 includes a housing 71, a reaction force applying motor 72 which is the driving source of the reaction force applying device 70, and a reduction gear. The reaction force applying motor 72 is indicated by a two-dot chain line in FIG. 2. When the driver operates the steering wheel 121, the reaction force applying device 70 drives the reaction force applying motor 72, and the torque of the reaction force applying motor 72 is increased by the reduction gear housed inside the housing 71, and then applied to the steering shaft 3.

The reducer is disposed in the housing 71 and is a worm reducer having a worm gear and a worm wheel that meshes with the worm gear. The reaction force applying motor 72 is disposed so that its rotation shaft is directly connected to the worm gear of the reducer disposed in the housing 71, that is, the reaction force applying motor 72 has its output shaft directly connected to the worm gear of the reducer. As a result, the reaction force applying motor 72 is disposed so that its rotation shaft is perpendicular to the axial direction of the steering shaft 3. In other words, the reaction force applying motor 72 is disposed so that its rotation shaft is perpendicular to the axial direction of the steering shaft 3 by applying the torque generated by the reaction force applying motor 72 to the steering shaft 3 via a reducer having a worm gear and a worm wheel.

At that time, the reaction force applying motor 72 is disposed such that the position of the rotation axis of the reaction force applying motor 72 in the axial direction of the steering shaft 3 is on the opposite side to the side where the steering wheel 121 is located, relative to the pivot bolt 65 used as the swing axis that is the center of swing in the tilt actuator 100. In other words, the pivot bolt 65 is disposed such that the position of the pivot bolt 65 in the axial direction of the steering shaft 3 is located rearward of the position of the rotation axis of the reaction force applying motor 72.

The torque applied to the steering shaft 3 from the reaction force applying device 70 configured as above is in the opposite direction to the rotational direction of the operation performed by the driver on the steering wheel 121, that is, the torque is in a direction that acts as a reaction force against the rotational operation of the steering wheel 121 by the driver. Therefore, the reaction force applying device 70 is capable of applying to the steering shaft 3 a torque whose rotational direction is opposite to the torque input from the steering wheel 121 to the steering shaft 3. This makes it possible for the reaction force applying device 70 to apply an operation reaction force against the driver's operation to the steering wheel 121 operated by the driver.

The magnitude of the reaction force applied to the steering wheel 121 by the reaction force applying device 70 is determined according to the steering angle of the steering wheel 121 acquired by the sensor and the torque applied to the steering shaft 3. The reduction gear is, for example, a worm reduction gear.

In the steering device 1 according to this embodiment, when adjusting the front-rear position of the steering wheel 121, the displacement bracket 21 is displaced relative to the fixed bracket 11 in the axial direction, i.e., in the front-rear direction, based on the energization of the lower telescopic motor 81, thereby displacing the column holder 20 relative to the front-rear direction. Alternatively, the upper column 40 is displaced relative to the lower column 50 of the column holder 20 in the axial direction, i.e., in the front-rear direction, based on the energization of the upper telescopic motor 91. Alternatively, when adjusting the front-rear position of the steering wheel 121, both the column holder 20 may be displaced relative to the front-rear direction based on the energization of the lower telescopic motor 81, and the upper column 40 may be displaced relative to the front-rear direction based on the energization of the upper telescopic motor 91.

In detail, when the lower telescopic motor 81 is energized, the rotational driving force of the lower telescopic motor 81 is transmitted from a worm attached to the output shaft of the lower telescopic motor 81 to the worm wheel 87, causing the worm wheel 87 to rotate. The rotational driving force transmitted from the lower telescopic motor 81 to the worm wheel 87 is transmitted to the screw shaft 83 via the torque limiter 89. That is, the torque limiter 89 rotates together with the worm wheel 87 due to the frictional force between the worm wheel 87 and the torque limiter 89, and transmits the rotational driving force to the screw shaft 83 due to the frictional force between the screw shaft 83 and the torque limiter 89, causing the screw shaft 83 to rotate.

When the screw shaft 83 rotates, the nut 84 that screws onto the screw shaft 83 is displaced in the axial direction of the screw shaft 83, i.e., in the front-rear direction, as the screw shaft 83 rotates. As a result, the displacement bracket 21 of the column holder 20, to which the nut 84 is supported and fixed by the nut support member 85, is displaced in the front-rear direction together with the nut 84. When the lower telescopic motor 81 is energized, the nut 84 is displaced in the front-rear direction in this way, and the displacement bracket 21 is displaced relative to the fixed bracket 11 in the axial direction of the fixed bracket 11, i.e., in the front-rear direction.

When the upper telescopic motor 91 is energized, the upper telescopic motor 91 rotates and drives the screw shaft 93 of the upper feed screw device 92 to displace the nut 94 in the front-rear direction. This displaces the upper column 40, to which the nut 94 is fixed, relative to the lower column 50 in the axial direction of the lower column 50, i.e., in the front-rear direction. This causes the overall length of the steering column 10 to expand and contract, and also the overall length of the steering shaft 3 to expand and contract, thereby adjusting the front-rear position of the steering wheel 121. After the front-rear position of the steering wheel 121 has been adjusted to the desired position, the energization of the lower telescopic motor 81 and the upper telescopic motor 91 is stopped.

When adjusting the vertical position of the steering wheel 121, the rear part of the lower column 50 is displaced vertically relative to the displacement bracket 21 based on the energization of the tilt motor 101. That is, the tilt motor 101 is energized, and the screw shaft 103 of the tilt feed screw device 102 is rotated by the tilt motor 101 to displace the nut 105 screwed onto the screw shaft 103 in the vertical direction. As a result, the lower column 50 pivoted by the pivot shaft portion 104 formed on the nut 105 is swung about the pivot bolt 65, and the rear part of the lower column 50 is displaced in the vertical direction. In this way, in the steering column device 2 according to this embodiment, the rear end of the steering shaft 3 rotatably supported on the radial inside of the steering column 10 is displaced in the vertical direction to adjust the vertical position of the steering wheel 121. After the vertical position of the steering wheel 121 is adjusted to the desired position, the energization of the tilt motor 101 is stopped.

The adjustment of the fore-aft position and the up-down position of the steering wheel 121 can be performed simultaneously or independently at different times. When adjusting the fore-aft position of the steering wheel 121, for example, the column holder 20 is largely displaced in the axial direction relative to the fixed bracket 11 at high speed, and then the axial displacement amount of the column holder 20 relative to the fixed bracket 11 and the axial displacement amount of the upper column 40 relative to the column holder 20 can be finely adjusted to adjust the fore-aft position of the steering wheel 121 to the desired position.

In the steering device 1 according to this embodiment, when adjusting the fore-aft position of the steering wheel 121, the fore-aft position is adjusted based on energization of the lower telescopic motor 81 or the upper telescopic motor 91. However, if a malfunction occurs in these motors and they cannot be operated, it becomes impossible to adjust the fore-aft position of the steering wheel 121 using the driving force of the motor. In this embodiment, in such a case, it is possible to manually adjust the fore-aft position of the steering wheel 121.

For example, when the driving control of the vehicle equipped with the steering device 1 is set to automatic driving, the driving control unit that switches the driving control of the vehicle between automatic driving and manual driving displaces the steering wheel 121 forward by controlling the lower telescopic actuator 80 and the upper telescopic actuator 90. As a result, during automatic driving, the distance between the driver and the steering wheel 121 is increased, and the space in front of the driver is increased, making it easier for the driver to relax.

When switching the vehicle's driving control from an automatic driving state to a manual driving state, the driving control unit displaces the steering wheel 121 rearward by controlling the lower telescopic actuator 80 and the upper telescopic actuator 90. As a result, during manual driving, the steering wheel 121 is displaced to a position where the driver can appropriately operate the steering wheel 121.

In this way, when switching the vehicle's driving control from automatic driving to manual driving, if a malfunction occurs in the motor used as a drive source for displacing the steering wheel 121 in the fore-and-aft direction and the motor cannot be operated, the steering wheel 121 cannot be displaced rearward. In such a case, in this embodiment, the vehicle is temporarily stopped in a position where it can be stopped, such as on the shoulder of the road, and the fore-and-aft position of the steering wheel 121 is manually adjusted, so that the steering wheel 121 can be displaced to a position where the driver can properly perform driving operations.

Next, a method for manually displacing the steering wheel 121 will be described. FIG. 10 is a plan view of the steering column device 2 showing a state in which the lower telescopic motor 81 cannot be operated when the column holder 20 is in a forward position. FIG. 11 is a perspective view of the steering column device 2 shown in FIG. 10. As shown in FIGS. 10 and 11, when the lower telescopic motor 81 cannot be operated when the column holder 20 is in a forward position, the steering wheel 121 attached to the steering shaft 3 stops in a forward position. In this case, in the steering device 1 according to this embodiment, the driver of the vehicle can manually displace the column holder 20 by engaging the operating member 110 with the engaging portion 83a formed on the end of the screw shaft 83.

The portion of the operating member 110 that engages with the engaging portion 83a of the screw shaft 83 is formed in the same polygonal shape as the engaging portion 83a, and the operating member 110 is a member that can engage with the engaging portion 83a by being inserted into the engaging portion 83a. Since the engaging portion 83a of the screw shaft 83 is formed in the shape of a hexagonal hole, the operating member 110 is a hexagonal rod-shaped member that is inserted into the engaging portion 83a and engages with the engaging portion 83a. For example, a so-called hexagonal wrench is used as the operating member 110.

Figure 12 is a side view of the steering column device 2 showing the state in which the operating member 110 is engaged with the engagement portion 83a of the screw shaft 83. The operating member 110 is engaged with the engagement portion 83a formed on the rear end of the screw shaft 83 by inserting it from the rear side into the engagement portion 83a. That is, the operating member 110 is engaged with the engagement portion 83a of the screw shaft 83 from the side where the steering wheel 121 attached to the steering shaft 3 is located. After engaging the operating member 110 with the engagement portion 83a, the driver applies a force to the operating member 110 to rotate the screw shaft 83 in a direction that displaces the column holder 20 in the desired direction.

For example, when the steering wheel 121 is positioned forward and a malfunction occurs in the lower telescopic motor 81, making it impossible to operate the lower telescopic motor 81, a force is applied to the operating member 110 engaged with the engaging portion 83a of the screw shaft 83 to rotate the screw shaft 83 in a direction that displaces the column holder 20 rearward. As a result, a rotational torque is input from the operating member 110 to the screw shaft 83, which is engaged with the engaging portion 83a of the operating member 110.

The portion of the screw shaft 83 near the end opposite the end where the engagement portion 83a is formed is inserted into the insertion hole 87a of the worm wheel 87 via the torque limiter 89, but the worm reducer has a so-called self-locking characteristic that makes it difficult to transmit rotation from the worm wheel 87 to the worm. Therefore, even if a rotational torque is applied to the screw shaft 83 by the operating member 110, the worm wheel 87 does not rotate due to self-locking, and a relatively large rotational torque acts between the screw shaft 83 and the worm wheel 87.

Here, the screw shaft 83 is inserted into the insertion hole 87a of the worm wheel 87 via the torque limiter 89, and the torque limiter 89 transmits rotation between the worm wheel 87 and the screw shaft 83 by frictional force. Therefore, when a relatively large rotational torque acts between the screw shaft 83 and the worm wheel 87, the torque limiter 89 causes slippage between the screw shaft 83 and the torque limiter 89, or between the worm wheel 87 and the torque limiter 89, due to the rotational torque. In other words, when the rotational torque acting from the screw shaft 83 to the worm wheel 87 side is equal to or greater than the torque that the torque limiter 89 can transmit without causing slippage, slippage occurs between the screw shaft 83 and the torque limiter 89, or between the worm wheel 87 and the torque limiter 89. As a result, the screw shaft 83 rotates relative to the worm wheel 87 due to the rotational torque applied to the screw shaft 83 by the operating member 110, and the screw shaft 83 can be rotated even if the worm wheel 87 is in a non-rotatable state.

Figure 13 is a side view of the steering column device 2 showing the state in which the column holder 20 is displaced relative to the fixed bracket 11 using the operating member 110. When the screw shaft 83 rotates due to the rotational torque applied from the operating member 110 to the screw shaft 83, the nut 84 screwed onto the screw shaft 83 is displaced in the axial direction of the screw shaft 83 as the screw shaft 83 rotates. As a result, the displacement bracket 21 of the column holder 20 to which the nut 84 is supported and fixed by the nut support member 85 is also displaced in the axial direction of the screw shaft 83 together with the nut 84. For this reason, for example, when the screw shaft 83 is rotated in a direction to displace the column holder 20 rearward by the force applied from the operating member 110 to the screw shaft 83, the nut 84 screwed onto the screw shaft 83 is displaced rearward as the screw shaft 83 rotates, and the column holder 20 to which the nut 84 is supported and fixed is also displaced rearward as shown in Figure 13.

As a result, the steering wheel 121 attached to the steering shaft 3 is also displaced rearward together with the column holder 20, and the steering wheel 121 can be displaced to a position where the driver can easily perform steering operations. Therefore, when the vehicle's driving control is switched from automatic driving to manual driving, if the lower telescopic motor 81 cannot be operated, the steering wheel 121 can be displaced in the fore-and-aft direction by rotating the screw shaft 83 using the operating member 110, and the steering wheel 121 can be positioned to a position where the driver can easily perform steering operations.

In the steering device 1 according to the present embodiment, the screw shaft 83 of the lower telescopic actuator 80, which displaces the column holder 20 axially relative to the fixed bracket 11, has an engagement portion 83a formed at one end with which the operating member 110 engages, and the screw shaft 83 is inserted into an insertion hole 87a of the worm wheel 87 via a torque limiter 89. When a rotational torque of a predetermined magnitude or more acts between the worm wheel 87 and the screw shaft 83, the torque limiter 89 interposed between the worm wheel 87 and the screw shaft 83 slides against the worm wheel 87 or the screw shaft 83, thereby allowing the relative rotation between the worm wheel 87 and the screw shaft 83.

Therefore, when the lower telescopic motor 81 cannot be operated due to a malfunction of the lower telescopic motor 81, the operating member 110 is engaged with the engagement portion 83a of the screw shaft 83, and a rotational torque is applied from the operating member 110 to the screw shaft 83, causing slippage in the torque limiter 89 to rotate the screw shaft 83 relative to the worm wheel 87. As a result, the nut 84 screwed onto the screw shaft 83 can be displaced in the axial direction of the screw shaft 83 as the screw shaft 83 rotates, and the column holder 20, to which the nut 84 is supported and fixed by the nut support member 85, can be displaced in the axial direction together with the nut 84 relative to the fixed bracket 11. Therefore, even when the lower telescopic motor 81 cannot be operated, the operation of displacing the column holder 20 in the axial direction relative to the fixed bracket 11 can be performed by rotating the screw shaft 83 using the operating member 110. As a result, even if it becomes impossible to operate the lower telescopic motor 81, the operation that was previously performed using the driving force generated by the lower telescopic motor 81 can still be performed.

In addition, in the steering device 1 according to this embodiment, the engagement portion 83a of the screw shaft 83 is formed at the end of the screw shaft 83 on the side where the steering wheel 121 attached to the steering shaft 3 is located, so that the operating member 110 can be engaged with the engagement portion 83a from a position closer to the steering wheel 121. Therefore, when rotating the screw shaft 83 using the operating member 110, the operating member 110 can be engaged with the engagement portion 83a of the screw shaft 83, and the screw shaft 83 can be rotated using the operating member 110. As a result, even if the lower telescopic motor 81 cannot be operated, the operation that was performed using the driving force generated by the lower telescopic motor 81 can be performed.

In addition, in the steering device 1 according to this embodiment, the engagement portion 83a of the screw shaft 83 is a polygonal hole, and the portion of the operating member 110 that engages with the engagement portion 83a is formed in the same polygonal shape as the engagement portion 83a, so that the operating member 110 can be inserted into the engagement portion 83a to engage with the engagement portion 83a. This allows the operating member 110 to be engaged with the engagement portion 83a of the screw shaft 83 in a state in which relative rotation is not possible, and the screw shaft 83 can be rotated using the operating member 110. As a result, even if the lower telescopic motor 81 cannot be operated, the operation that was previously performed using the driving force generated by the lower telescopic motor 81 can be performed.

In addition, the steering device 1 according to this embodiment can ensure the axial displacement of the column holder 20 in the event that the lower telescopic motor 81 becomes inoperable. As a result, even if the lower telescopic motor 81 cannot be operated in an automatically driven vehicle and therefore the steering wheel 121 cannot be displaced in the fore-and-aft direction by the lower telescopic motor 81, the steering wheel 121 can be displaced to a position suitable for manual driving. As a result, when the steering device 1 is installed in an automatically driven vehicle, the operability of steering by manual driving can be ensured.

In addition, in the steering device 1 according to this embodiment, the steering column 10 is configured by combining the fixed bracket 11 and the column holder 20 in a manner that allows relative axial displacement, and by combining the column holder 20 and the upper column 40 in a manner that allows relative axial displacement. In other words, the steering column 10 has a two-stage telescopic structure. This makes it possible to prevent the axial dimensions of the screw shaft 83 of the lower feed screw device 82 and the screw shaft 93 of the upper feed screw device 92 from becoming excessively large, while ensuring a sufficient amount of telescopic movement of the entire length of the steering column 10.

In addition, in the steering device 1 of this embodiment, by simultaneously energizing the lower telescopic motor 81 of the lower telescopic actuator 80 and the upper telescopic motor 91 of the upper telescopic actuator 90, the column holder 20 can be displaced in the axial direction relative to the fixed bracket 11, and at the same time, the upper column 40 can be displaced in the axial direction relative to the column holder 20. Therefore, it is easier to increase the extension and retraction speed of the steering column 10 compared to a structure in which the entire length of the steering column is extended and retracted by a single electric motor.

In addition, in order to ensure the amount of extension and retraction of the steering column 10 while increasing the extension and retraction speed, if the steering column 10 has a two-stage telescopic structure, the axial movement amount of the column holder 20 and the upper column 40 can be reduced. In other words, if the steering column 10 has a two-stage telescopic structure, the axial movement amount of the column holder 20 by the lower side feed screw device 82 and the axial movement amount of the upper column 40 by the upper side feed screw device 92 can be reduced compared to when the telescopic structure of the steering column 10 has a single stage. This makes it possible to prevent the manual movement amount of the column holder 20 from becoming too large when manually rotating the screw shaft 83 to manually adjust the front-rear position of the steering wheel 121 when the lower side telescopic motor 81 cannot be operated. As a result, even if the lower side telescopic motor 81 cannot be operated, the operation that was performed using the driving force generated by the lower side telescopic motor 81 can be easily performed.

[Modification]
In the steering device 1 according to the embodiment described above, the screw shaft 83 of the lower telescopic actuator 80 is inserted through a torque limiter 89 into an insertion hole 87a of a worm wheel 87 that rotates by the driving force from a lower telescopic motor 81, but actuators other than the lower telescopic actuator 80 may have a similar configuration.

For example, the column holder 20 may constitute the first column member, the upper column 40 may constitute the second column member, and the upper telescopic actuator 90 may be configured to have a torque limiter. In this case, the upper telescopic actuator 90 has a screw shaft 93 (see FIG. 2) of the upper feed screw device 92, which is inserted into an insertion hole of a worm wheel (not shown) that rotates by a driving force from the upper telescopic motor 91 (see FIG. 4) via a torque limiter (not shown) similar to the torque limiter 89 of the lower telescopic actuator 80. In addition, the screw shaft 93 has an engagement portion similar to the engagement portion 83a formed at the end of the screw shaft 83 of the lower telescopic actuator 80, formed at the rear end of the screw shaft 93. The screw shaft 93 is arranged with its rear end exposed toward the rear side, similar to the screw shaft 83 of the lower telescopic actuator 80, so that an operating member can be engaged with the engagement portion.

Because the upper telescopic actuator 90 is configured as described above, even if the upper telescopic motor 91 cannot be operated, the torque limiter can be slipped and the screw shaft 93 can be rotated by engaging the operating member with the engagement portion of the screw shaft 93 to apply a rotational torque to the screw shaft 93. Therefore, even if the upper telescopic motor 91 cannot be operated, the operation of displacing the upper column 40 in the axial direction relative to the column holder 20 can be performed by rotating the screw shaft 93 using the operating member. As a result, even if the upper telescopic motor 91 cannot be operated, the operation that was performed using the driving force generated by the upper telescopic motor 91 can be performed.

In the steering device 1 according to the embodiment described above, the engagement portion 83a formed on one end of the screw shaft 83 is a polygonal hole, and the operating member 110 engages with the engagement portion 83a by forming the portion that engages with the engagement portion 83a in the same polygonal shape as the shape of the engagement portion 83a, but the engagement portion 83a and the operating member 110 may have other shapes. For example, a hole into which the engagement portion 83a formed on the screw shaft 83 enters may be formed on the operating member 110 side, and the engagement portion 83a formed on the screw shaft 83 may be configured to engage with the operating member 110 by the engagement portion 83a formed on the screw shaft 83 entering a hole formed on the operating member 110. The configuration of the engagement portion 83a formed on one end of the screw shaft 83 and the operating member 110 is not important as long as they can be engaged with each other and the screw shaft 83 can be rotated by the operating member 110 engaged with the engagement portion 83a.

In addition, while the steering column 10 according to the embodiment described above has a two-stage telescopic structure, the present disclosure can also be applied to a steering column device in which the steering column has a one-stage telescopic structure.

In the above embodiment, as an example of the present disclosure, a case has been described in which the present disclosure is applied to a steering column device 2 that has both a telescopic mechanism for adjusting the fore-aft position of the steering wheel 121 and a tilt mechanism for adjusting the up-down position, but the present disclosure can also be applied to a steering column device that has only a telescopic mechanism.

Although preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to those described in the above embodiments. The configurations described as embodiments and modified examples may be combined as appropriate.

REFERENCE SIGNS LIST 1 steering device 2 steering column device 3 steering shaft 10 steering column 11 fixed bracket 12 fixed plate portion 20 column holder 21 displacement bracket 22 displacement plate portion 30 linear guide 40 upper column 50 lower column 60 inner column 65 pivot bolt 70 reaction force applying device 71 housing 72 reaction force applying motor 80 lower telescopic actuator 81 lower telescopic motor 82 lower feed screw device 83 screw shaft 83a engagement portion 84 nut 85 nut support member 86 housing 87 worm wheel 87a insertion hole 89 torque limiter 90 upper telescopic actuator 91 upper telescopic motor 92 upper feed screw device 100 tilt actuator 101 tilt motor 102 Tilt feed screw device 110 Operation member 120 Steering system 121 Steering wheel 130 Steering device 131 Actuator 132 Tie rod 135 Steering wheel

Claims (3)

a steering shaft having a steering wheel attached to one end thereof and rotated by torque input from the steering wheel;
a steering column including a first column member and a second column member combined with the first column member so as to be displaceable relative to the first column member in an axial direction, the steering column supporting the steering shaft in a freely rotatable manner;
a telescopic actuator that displaces the second column member in an axial direction relative to the first column member;
Equipped with
The telescopic actuator includes:
A telescopic motor as a drive source;
a worm wheel that rotates by a driving force from the telescopic motor;
a screw shaft that is inserted into an insertion hole formed in the worm wheel and rotates together with the worm wheel;
A nut that displaces in the axial direction of the screw shaft as the screw shaft rotates and is supported and fixed to the second column member by a nut support member;
having
The screw shaft has an engagement portion formed at one end with which an operating member that inputs a rotational torque to the screw shaft engages,
The screw shaft is inserted into the insertion hole via a torque limiter that is formed in an annular shape and transmits the rotation of the worm wheel from the worm wheel to the screw shaft by frictional force,
The torque limiter is a steering device that allows relative rotation between the worm wheel and the screw shaft by slipping against the worm wheel or the screw shaft when a rotational torque equal to or greater than a predetermined magnitude acts between the worm wheel and the screw shaft. The screw shaft is disposed parallel to the steering shaft,
The steering device according to claim 1 , wherein the engagement portion is formed at an end of the threaded shaft on a side where the steering wheel attached to the steering shaft is located. The engagement portion is a polygonal hole,
The steering device according to claim 1 or 2, wherein the operating member has a portion that engages with the engaging portion, the portion being formed in the same polygonal shape as the engaging portion, and the operating member is engaged with the engaging portion by being inserted into the engaging portion.

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