JPH10297503A - Steering position adjusting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the durability of the switching mechanism of a steering position adjusting device which switches a tilting motion and a telescopic motion by the switching mechanism and to improve the rigidity of the device. SOLUTION: A switching mechanism 20 has a switching nut 46 screwing onto a screw shaft 40 and a moving pin 48 which is engaged with a teeth 46b to prevent the rotation of the switching nut 46. In a state in which the switching nut 46 is prevented from rotating, the switching mechanism 20 acts as a nut to prevent the drive force of the screw shaft 40 from being transmitted to the switching nut 46. In this case, only a force for preventing the switching nut 46 from being corotated is applied to the moving pin 48. In a state in which the switching nut 46 is not prevented from being rotated, the switching mechanism 20 acts as a bearing to transmit a drive force produced by the screw shaft 40 to the switching mechanism 20. In this case, the above mentioned drive force is not applied to the moving pin 46.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a steering position adjusting device, and more particularly to a steering position adjusting device that switches between a tilt operation and a telescopic operation by using a switching mechanism.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Unexamined Patent Publication No. 7-81585
As disclosed in Japanese Patent Application Laid-Open No. H10-260, there is known a steering position adjusting device that adjusts the position of a steering wheel up and down and forward and backward with respect to a driver. The conventional steering position adjusting device includes a cylindrical column tube fixed to a vehicle body, a tilt support slidably provided in an axial direction with respect to the column tube, and a tilt support that can be tilted up and down with respect to the tilt support. And an upper tube that is supported and rotatably supports the steering wheel. When the tilt support slides with respect to the column tube, a telescopic operation in which the steering moves forward and backward is realized. On the other hand, a tilt operation in which the steering moves up and down by the upper tube swinging with respect to the tilt support is realized.

Further, the conventional steering position adjusting device includes a tilting lever connected to the upper tube, a screw shaft one end of which is swingably connected to the tilting lever, and which is rotated by a motor, a screw shaft and a tilt support. And a switching mechanism capable of switching between a state in which is engaged and a state in which it is not engaged. When the screw shaft is rotated by the motor and the screw shaft and the tilt support are engaged, the axial driving force generated by the screw shaft is transmitted to the tilt support via the switching mechanism. For this reason, the tilt support is slid with respect to the column tube, and a telescopic operation is realized. On the other hand, when the screw shaft and the tilt support are not engaged, the axial driving force generated by the screw shaft is transmitted to the tilt lever. For this reason, the tilt support is tilted via the tilt lever, and a tilt operation is realized. At this time, since the screw shaft and the tilting lever are swingably connected to each other, an excessive load is prevented from being applied to the connecting portion.

As described above, in the above-described conventional steering position adjusting device, the engagement state between the screw shaft and the tilt support is switched by the switching mechanism, so that the telescopic operation and the tilt operation are selectively realized. You.

[0005]

As described above, in the above-described conventional apparatus, the driving force is transmitted from the screw shaft to the tilt support via the switching mechanism during the telescopic operation. Generally, in order to secure the rigidity of the steering column, the sliding resistance between the column tube and the tilt support is large. Therefore, the driving force to be transmitted to the tilt support for the telescopic operation is large, and a large force acts on the switching mechanism.
For this reason, in the above-mentioned conventional apparatus, there was a problem that it was difficult to ensure sufficient durability of the switching mechanism.

Further, in the above-mentioned conventional apparatus, the upper tube is swingably connected to the screw shaft via a tilting lever. Further, as described above, the upper tube is swingably connected to the tilt support. That is, the upper tube is supported only by the swingable connection mechanism. Generally, the rigidity of the swingable connection mechanism is low, and it is difficult to support the upper tube with high rigidity by such a configuration. For this reason, in the above-described conventional apparatus, there is also a problem that the support rigidity of the steering column is low, and vibration of the vehicle body is easily transmitted to the steering.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and provides a steering position adjusting device capable of improving the durability of a switching mechanism and ensuring high rigidity of the entire device. The purpose is to provide.

[0008]

An object of the present invention is to provide a column tube fixed to a vehicle body, a tilt support slidably provided with respect to the column tube, and a tilt support capable of tilting up and down with respect to the tilt support. And an upper tube rotatably supporting a steering wheel, and the column tube, the tilt support, and
A screw shaft supported by the upper tube, a nut screwed to the screw shaft, a motor for rotating the screw shaft, and an axial driving force generated by the screw shaft; any of the tilt support or the column tube; A transmission mechanism that selectively realizes a telescopic operation in which the column tube and the tilt support are relatively displaced and a tilt operation in which the tilt support and the upper tube are relatively displaced. In the steering position adjusting device provided, the switching mechanism includes a housing, a switching nut screwed to the screw shaft, and the switching nut being rotated around the axis while preventing relative displacement in the axial direction with respect to the housing. Support means for rotatably supporting, And rotation preventing means for preventing relative rotation about the axis relative to the housing of the serial switching nut is achieved by a steering position adjusting device comprising a.

In the present invention, a nut is screwed into the screw shaft. Therefore, when the screw shaft is rotated by the motor, the screw shaft generates a driving force in the axial direction. The support means of the switching mechanism supports the switching nut so as to be rotatable around the axis while preventing relative displacement in the axial direction with respect to the housing. Accordingly, a state in which the rotation preventing means prevents the relative rotation of the switching nut around the axis with respect to the housing (hereinafter, referred to as a locked state).
Thus, the switching mechanism acts as a nut for the screw shaft. Therefore, in the locked state, the driving force generated by the screw shaft is not transmitted to the switching mechanism. On the other hand, in a state where relative rotation of the switching nut with respect to the housing is not prevented (hereinafter, referred to as an unlocked state), the switching nut rotates together with the screw shaft. In this case, since the relative displacement of the switching nut with respect to the housing in the axial direction is prevented, the driving force generated by the screw shaft is transmitted to the housing of the switching mechanism. Thus, by switching between the locked state and the unlocked state, the transmission state of the driving force generated by the screw shaft is switched. By the way, in the locked state, only the force for preventing the switching nut and the screw shaft from rotating together acts on the rotation preventing means. In the unlocked state, no external force acts on the rotation preventing means. Therefore, in the present invention, a large external force is prevented from acting on the rotation preventing means in both the locked state and the unlocked state.

According to a second aspect of the present invention, there is provided a steering position adjusting device according to the first aspect, wherein the rotation preventing means includes a recess provided in one of the switching nut or the housing, This is achieved by a steering position adjusting device including: a pin provided on the other side of the switching nut or the housing; and urging means for urging the pin toward the recess when rotation of the screw shaft is started. You.

In the present invention, the rotation of the switching nut is prevented by the engagement between the pin and the recess. When the rotation of the screw shaft is started, the pin is urged toward the recess by the urging means. Therefore, even when the pin is in the position deviated from the recess, when the rotation of the screw shaft is started, the switching nut rotates together and the pin and the recess face each other. Is prevented from rotating. Thus, according to the present invention, the rotation of the switching nut by the rotation preventing means is reliably prevented.

According to a third aspect of the present invention, in the steering position adjusting device according to the first aspect, the bending means for bending the screw shaft includes:
This is achieved by a steering position adjusting device that is provided between a support portion of the screw shaft by the column tube and a support portion by the tilt support, and the screw shaft is swingably supported by the tilt support.

In the present invention, the bending means for bending the screw shaft is provided between the support portion of the screw shaft by the column tube and the support portion by the tilt support. The screw shaft is swingably supported by the tilt support. Therefore, the part on the upper tube side from the bending means of the screw shaft,
It can be tilted following the tilting of the upper tube. In general, the column tube and the tilt support are connected with high rigidity. Therefore, by providing the bending means between the support part by the column tube and the support part by the tilt support, it is possible to prevent the rigidity of the bending means from affecting the rigidity of the entire apparatus.

Further, the above object is achieved by a worm wheel provided in the steering position adjusting device according to the first aspect, wherein the rotation preventing means is provided so as to rotate integrally with the switching nut. And a worm gear that meshes with the worm wheel, and a drive unit that rotates the worm gear.

In the present invention, the worm wheel and the worm gear mesh with each other. Therefore, rotation is transmitted from the worm gear to the worm wheel at a predetermined reduction ratio, and rotation is not transmitted from the worm wheel to the worm gear. The worm gear is provided so as to rotate integrally with the switching nut. Therefore, the rotation of the worm gear is transmitted to the switching nut, but the rotation of the switching nut is not transmitted to the worm gear. Therefore, the rotation of the switching nut is prevented when the worm gear is not rotated. On the other hand, when the worm gear is rotated by the driving means, the worm wheel rotates at a speed corresponding to the rotation speed of the worm gear. In this case, rotation of the switching nut is allowed. As described above, in the present invention, the switching between the state in which the rotation of the switching nut is blocked and the state in which the rotation is not blocked is performed by stopping and rotating the worm gear. For this reason,
It is not necessary to provide a movable part for preventing rotation of the switching nut, and accordingly, a mechanism for moving the movable part is not required. Further, by switching between a state in which the rotation of the switching nut is blocked and a state in which the rotation of the switching nut is not blocked by the stop or rotation of the worm gear,
The above switching is realized without a time delay.

In the steering position adjusting device according to the first aspect of the present invention, the rotation preventing means may include a movable pin provided on one of the switching nut or the housing. A recess provided to allow relative rotation between the switching nut and the housing only in a predetermined angle range in a state where the movable pin is inserted into the other of the switching nut or the housing, and After the rotation of the screw shaft is stopped in a state where the relative rotation between the switching nut and the housing is prevented by the rotation preventing means,
This is also achieved by a steering position adjusting device provided with reverse rotation means for rotating the screw shaft by a predetermined angle in a direction opposite to the previous rotation direction.

In the present invention, when the movable pin is inserted into the recess, the relative rotation between the switching nut and the housing is:
It is allowed only in a predetermined angle range. That is, when the movable pin is inserted into the concave portion, relative rotation between the switching nut and the housing exceeding a predetermined angle range is prevented. When the relative rotation between the switching nut and the housing is prevented, a reaction force against the rotational torque transmitted from the screw shaft to the switching nut acts between the concave portion and the movable pin. In the present invention, after the rotation of the screw shaft is stopped, the reverse rotation means rotates the screw shaft by a predetermined angle in a direction opposite to the previous rotation direction. In a state in which the relative rotation of the switching nut with respect to the housing is prevented in one direction, the relative rotation in the other direction within the predetermined angle range is allowed. Therefore, when the screw shaft is rotated by a predetermined angle in the opposite direction, the switching nut also rotates together with the screw shaft. Thereby, the above-mentioned reaction force acting between the concave portion and the movable pin is eliminated.

[0018]

FIG. 1 is a block diagram of a steering position adjusting device 10 according to an embodiment of the present invention. As shown in FIG. 1, the steering position adjusting device 10 of the present embodiment includes a column tube 12. The column tube 12 is fixed in the passenger compartment. A telescopic tube 14 is connected to the column tube 12 so as to be slidable in the axial direction. A tilt support 16 is fixed to the telescopic tube 14. A switching mechanism 20 is connected to a lower side of the side surface of the tilt support 16 in FIG. 1 via a bearing 18 so as to swing up and down in FIG. An upper tube 22 is connected to the tilt support 16 so as to be tiltable up and down in FIG. A motor 26 is connected to the upper tube 22 via a bearing 24 so as to be able to swing up and down in FIG. The upper tube 22 has a steering shaft 28.
The steering wheel 30 is rotatably supported around an axis via the shaft.

A nut 34 is connected via a bearing 32 to the lower side of the side surface of the column tube 12 in FIG. The nut 34 has a screw shaft 36
Is screwed. One end (the left end in FIG. 1) of the screw shaft 40 is connected to one end (the right end in FIG. 1) of the screw shaft 36 via a hooks joint 38. The screw shaft 40 passes through the switching mechanism 20 and is connected to the motor shaft of the motor 26 at the other end (the right end in FIG. 1).

Next, referring to FIGS.
Will be described. FIG. 2 is a cross-sectional view when the switching mechanism 20 is cut along the axial direction of the screw shaft 40. FIG. 3 is a cross-sectional view taken along the line III-III shown in FIG. FIG. 4 is a diagram showing a state in which the switching nut 46 is locked in FIG. FIG.
As shown in FIG. 2, the switching mechanism 20 includes a housing 42. The switching mechanism 20 is connected to the tilt support 16 by the housing 42 being supported by the bearing 18. The housing 42 has a cylindrical through opening 42 a extending parallel to the screw shaft 40. The through-opening 42a includes a small-diameter portion 42b and a large-diameter portion 42c provided on the right side of FIG. 2 with respect to the small-diameter portion 42b, and a step 42d is formed at the boundary. The outer race of the bearing 44 is press-fitted into the small diameter portion 42b of the through-opening 42a until one end surface (the right end surface in FIG. 2) of the outer race engages with the step 42d. Further, a circlip 45 is fitted into the small diameter portion 42b so as to engage with the other end surface of the bearing 44. As a result, relative displacement of the bearing 44 in the axial direction with respect to the housing 42 is prevented.

A switching nut 46 is disposed inside the through-opening 42a of the housing 42. The switching nut 46 has a small-diameter portion 46a and a small-diameter portion
A large-diameter portion 46b is provided on the middle right side, and a step 46c is formed at the boundary. Switching nut 4
6 is pressed into the inner peripheral surface of the inner race of the bearing 44 until the step 46c engages with the right end surface of the bearing 44 in FIG. A fixed nut 47 is screwed to the left end in FIG. 2 of the small diameter portion 46a of the switching nut 46 until it engages with the left end surface of the bearing 44 in FIG. Thereby, the switching nut 46
Of the bearing 44 with respect to the bearing 44 is prevented. Therefore, the switching nut 46 is rotatably supported by the housing 42 in a state where displacement in the axial direction is prevented.

As shown in FIG. 3, the switching nut 46 has a tooth portion 46d formed of a plurality of teeth formed at an equal pitch on the outer peripheral surface of the large diameter portion 46b. A pin hole 42 is formed in the inner peripheral surface of the through opening 42a so as to face the tooth portion 46d.
e is provided. A movable pin 48 is slidably disposed inside the pin hole 42e. Teeth 48a are provided at the end of the movable pin 48 on the side facing the tooth part 46d. The teeth 48a are formed in a shape that can mesh with the teeth 46d. A solenoid 5 is provided around the movable pin 48.
0 is provided. The movable pin 48 is urged by urging means (not shown) in a direction away from the teeth 46d. Therefore, in a state where the solenoid 50 is not energized,
As shown in FIG. 3, the teeth 48a of the movable pin 48 are spaced apart from the teeth 46d of the switching nut 46 on the outer diameter side. Therefore, in such a state, the rotation of the switching nut 46 is not prevented by the movable pin 48. On the other hand, when the solenoid 50 is energized, the movable pin 48 is displaced toward the tooth portion 46d by the electromagnetic force generated by the solenoid 50, and the tooth 48a of the movable pin 48 becomes the tooth portion 46d of the switching nut 46 as shown in FIG. Mesh with the valley. In this state, the rotation of the switching nut 46 about the axis with respect to the housing 42 is prevented by the movable pin 48a, and the switching nut 46 is locked.

Next, the operation of the steering position adjusting apparatus 10 according to the present embodiment will be described with reference to FIGS. As described above, when the solenoid 50 of the switching mechanism 20 is energized (hereinafter, referred to as an energized state), the rotation of the switching nut 46 with respect to the housing 42 is prevented. Therefore, even when the screw shaft 40 is rotated, the switching nut 46 does not rotate together with the screw shaft 40. That is, the switching mechanism 20 acts as a nut for the screw shaft 40. Therefore, in the energized state, when the screw shaft 40 is rotated by driving the motor 26,
While the distance L _Te between the nut 34 and the switching mechanism 20 does not change, the distance L _Ti between the switching mechanism 20 and the motor 26 changes. Therefore, when the screw shaft 40 is rotated in a direction in which the distance L _Ti increases, the upper tube 22 faces upward in the figure with the relative position of the tilt support 16 to the column tube 12 fixed as shown in FIG. To be tilted. In addition, screw shaft 4
When 0 is rotated in the opposite direction, the upper tube 2
2 is tilted downward in the figure. Thus, in the energized state, a tilt operation in which the upper tube 22 tilts up and down according to the rotation direction of the screw shaft 40 is realized.

In the above-mentioned tilt operation, the switching nut 46
An axial reaction force to the driving force transmitted from the screw shaft 40 to the upper tube 22 acts on the meshing portion between the screw shaft 40 and the screw shaft 40. On the other hand, the movable pin 4
Only a force acts on 8 to prevent the switching nut 46 and the screw shaft 40 from rotating together. Therefore, in the steering position adjusting device 10 according to the present embodiment, the force acting on the movable pin 48 during the tilt operation is suppressed to be small.

The reaction force acting on the meshing portion between the screw shaft 40 and the switching nut 46 is transmitted to the housing 42 via the bearing 44. In this case, as described above, since the relative displacement in the axial direction between the switching nut 46, the bearing 44, and the housing 42 is prevented, a relative displacement may occur between these members due to the reaction force. Has been prevented.

On the other hand, through the solenoid 50 of the switching mechanism 20,
In the non-powered state (hereinafter referred to as the non-powered state),
As described above, the rotation of the switching nut 46 with respect to the housing 42 is performed.
Rolling is not prevented. For this reason, the screw shaft 40
Is rotated, the switching nut 46 is connected to the screw shaft.
Co-rotates with 40. That is, in the non-energized state,
The switching mechanism 20 includes a bearing for the screw shaft 40 and
Will work. Therefore, the screw shaft
When the switch 40 is rotated, the distance between the switching mechanism 20 and the motor 26 is increased.
Release L_TiDoes not change, whereas the nut 34 and the switching mechanism
Distance L to 20 _TeChanges. Therefore, the distance L_TeIs reduced
When the screw shaft 40 is rotated in a small direction,
As shown in FIG. 6, the tilt support of the upper tube 22
Tilt support with posture fixed to 16
Reference numeral 16 is slid leftward in the figure. Also, screw
When the shaft 40 is rotated in the opposite direction, the tilt support
The seat 16 is slid rightward in FIG. Thus, non-
In the energized state, the rotation of the screw shaft 40
The tilt support 16 moves right and left in FIG. 6 according to the direction.
Telescopic operation is realized.

In this telescopic operation, the driving force for sliding the tilt support 16 is transmitted from the screw shaft 40 to the switching nut 46 of the switching mechanism 20, the bearing 44,
And transmitted to the tilt support 16 via the housing 42. In this case, as described above, since the relative displacement in the axial direction between the switching nut 46, the bearing 44, and the housing 42 is prevented, the driving force of the driving force is generated without causing relative displacement between these members. Transmission can be performed efficiently.

The driving force to the tilt support 16 is transmitted from the screw shaft 40 to the switching nut 46, so that the screw shaft 40 and the switching nut 46
The frictional force against the relative rotation between and is increased. For this reason, during the telescopic operation, the screw shaft 40 and the switching nut 46 can surely rotate together without causing slippage in the relative rotation direction, whereby the transmission of the driving force to the tilt support 16 is more efficiently performed. It is possible to do. During the telescopic operation, the movable pin 48 is separated from the tooth portion 46d of the switching nut 46, so that no external force acts on the movable pin 48.

As described above, in this embodiment, the switching nut 46 of the switching mechanism 20 is locked by the movable pin 48, that is, acts on the movable pin 48 from the teeth 46d of the switching nut 46 during the tilt operation. The force is kept small. Further, during the telescopic operation, no external force acts on the movable pin 48. Thus, according to the steering position adjusting device 10 of the present embodiment, the external force acting on the movable pin 48 is suppressed, so that the movable pin 48 is hardly damaged. Further, during the tilt operation, the force acting on the movable pin 48 from the tooth portion 46d of the switching nut 46 decreases as the outer diameter of the switching nut 46 increases. Therefore, by appropriately setting the outer diameter of the switching nut 46, the movable pin 48 can be made harder to be damaged. As described above, in the present embodiment, the movable pin 48 is hardly damaged, and thus the durability of the switching mechanism 20 is improved.

Further, since the screw shaft 36 and the screw shaft 40 are connected by the hooks joint 38, the screw shaft 40 can tilt following the tilt of the upper tube 22 during the tilt operation. For this reason, the meshing portion between the screw shaft 36 and the nut 34 or the screw shut 40
It is not necessary to provide a backlash for absorbing the tilt of the screw shaft at the meshing portion of the steering mechanism with the switching nut 46 of the switching mechanism 20, thereby increasing the rigidity of the steering position adjusting device 10.

By the way, the rigidity of the swingable connecting mechanism such as the hooks joint 38 is relatively small. For this reason,
If such a coupling mechanism is arranged so as to affect the rigidity of the entire steering position adjusting device, the rigidity of the entire device is reduced, which causes inconveniences such as transmission of large vibrations to the steering during running of the vehicle. On the other hand, in the present embodiment, the hooks joint 38 is disposed between the nut 34 fixed to the column tube 12 and the switching mechanism 20 connected to the tilt support 16. That is, the hooks joint 38 is provided in parallel with the connection between the column tube 12 and the tilt support 18. Generally, the column tube 12 and the telescopic tube 14 are connected with high rigidity so as to prevent rattling in order to secure the rigidity of the steering column.
It is fixed to. That is, the column tube 12 and the tilt support 16 are connected with high rigidity. Therefore, the column tube 12 and the tilt support 1
The influence of the rigidity of the hooks joint 38 provided in parallel with the connecting portion with the steering position adjusting device 10 on the overall rigidity of the steering position adjusting device 10 is small. As described above, in the present embodiment, the rigidity of the steering position adjusting device 10 is reduced by appropriately selecting the arrangement position of the hooks joint 38 having a low rigidity despite the provision thereof. That has been prevented.

Next, a steering position adjusting device 60 according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 7 is a configuration diagram of the steering position adjusting device 60 of the present embodiment. 7, the same components as those in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted. As shown in FIG. 7, a motor 62 and a nut 64 are fixed to a lower side of the side surface of the column tube 12 in the drawing. The nut 64 is connected to the motor shaft 62a of the motor 62.
The motor 62 is disposed on the right side in FIG. A screw shaft 66 is screwed into the nut 64. One end (the left end in FIG. 7) of the screw shaft 66 is connected to a motor shaft 62a of the motor 62.

FIG. 8 is a cross-sectional view when the connection between the motor shaft 62a and the screw shaft 66 is cut along the line VIII-VIII shown in FIG. As shown in FIG. 8, an engagement portion 66a formed with two flat portions facing each other is provided at a connection portion between the screw shaft 66 and the motor shaft 62a. Further, the engaging portion 66 of the screw shaft 66 is provided on the end face of the motor shaft 62a.
engagement hole 62b having a substantially rectangular cross-sectional shape that can be fitted with a
Is provided. The screw shaft 66 and the motor shaft 62a are capable of transmitting rotation about an axis by the engagement portion 66a being fitted into the engagement hole 62b, and
They are connected so as to be relatively displaceable in the axial direction.

The screw shaft 66 extends through the switching mechanism 20 and is connected to the tilt support 22 via a connecting mechanism 68 at the other end (the right end in FIG. 7). Hereinafter, the configuration of the coupling mechanism 68 will be described with reference to FIG.
FIG. 9 is a cross-sectional view when the connecting mechanism 68 is cut along the line IX-IX shown in FIG. As shown in FIG. 9, the connection mechanism 68 includes a connection link 70. The connecting link 70 is formed by a first connecting portion 70a having a flat plate shape and a first connecting portion 70 shown in FIG.
It comprises a second connecting portion 70b branched in a U-shape toward the middle left. Pin holes 70c and 70d are provided in each branch portion of the second connecting portion 70b. Pin hole 70
Pins 72 and 74 are inserted into c and 70d, respectively. In the space between the two branch portions of the second connecting portion 70b,
A bearing holding member 76 is provided around the pins 72 and 74. The bearing bushes 80 and 82 are provided on the bearing holding member 76.
And the pins 72 and 74, and between the bearing holding member 76 and each of the branch portions of the second connecting portion 70b. The bearing bushes 80 and 82 allow the connection link 70 and the bearing holding member 76 to relatively rotate around the axes of the pins 72 and 74.

The bearing holding member 76 includes a thrust bearing 84,
86 are held coaxial with each other. The small diameter portion 66b provided at the end of the screw shaft 66 penetrates the thrust bearings 84 and 86, and a nut 90 is fastened to a protruding portion from the thrust bearing 86. When the nut 90 is tightened, the screw shaft 66 is rotatably supported around the axis by the thrust bearings 84 and 86, and the thrust bearings 84 and 86 are attached to the bearing holding member 76.
Fixed against.

The first connecting portion 70a of the connecting link 70 is sandwiched between the flange portions 22a and 22b of the upper tube 22. The first connecting portion 70a is provided with a pin hole 70e. Also, the flange portion 2 of the upper tube 22
The pin holes 22a and 22b are coaxial with the pin holes 70e.
c and 22d are provided respectively. Bolt 91
The pin holes 20b, 70e, and 20d are provided so as to penetrate them, and are fastened by nuts 92. The bearing bush 94 is provided between the bolt 90 and the pin hole 70e, and between the first connecting portion 70a of the connecting link 70 and the upper tube 22.
Are provided so as to be interposed between the flange portions 22a and 22b. With the bearing bush 94, the connecting link 7
0 and the upper tube 22 can relatively rotate around the axis of the bolt 91.

As described above, the connecting link 70 is rotatably connected to the bearing holding member 76 around the axes of the pins 72 and 74, and the screw shaft 66 is connected to the thrust bearing 80 fixed to the bearing holding member 76. , 82 so as to be rotatable about its axis. Further, as described above, the connection link 70 is connected to the upper tube 22 so as to be rotatable around the axis of the bolt 91. Therefore, the connection mechanism 68 functions as a link member that connects the screw shaft 66 to the upper tube 22 so as to rotate about its axis and swing vertically.

Next, the operation of the steering position adjusting device 60 of this embodiment will be described with reference to FIGS. 10 and 11 together with FIG. In the present embodiment, the distance between the nut 64 and the switching mechanism 20 is defined as L _Te, and the coupling between the switching mechanism 20 and the shaft 66 to the coupling mechanism 68, that is, the pins 72 and 74 The distance between the axis and L _Ti
Is defined.

As in the first embodiment, when the solenoid 50 of the switching mechanism 20 is energized, the switching mechanism 20 acts as a nut on the screw shaft 66. Therefore, when the screw 62 is rotated by driving the motor 62 in the energized state, the distance L _Te between the nut 64 and the switching mechanism 20 does not change, whereas the switching mechanism 20 and the screw shaft 66 The distance L _Ti from the connecting portion to the connecting mechanism 68 changes. For this reason, when the screw shaft 66 is rotated in the direction in which the distance L _Ti increases, the upper tube 22 moves upward in the figure with the relative position of the tilt support 16 to the column tube 12 fixed as shown in FIG. To be tilted. When the screw shaft 66 is rotated in the opposite direction, the upper tube 22 is tilted downward in FIG. Thus, in the energized state, a tilt operation in which the upper tube 22 tilts up and down according to the rotation direction of the screw shaft 66 is realized.

In this case, the tilting of the coupling mechanism 68 following the tilting of the upper tube 22 prevents the screw shaft 66 from tilting during the tilting operation. For this reason, also in this embodiment, similarly to the case of the steering position adjusting device 10 of the first embodiment, the screw shaft 66 and the nut 64 or the switching mechanism 2 are used.
It is not necessary to provide a backlash for absorbing the tilt of the screw shaft 66 at the meshing portion with the zero switching nut 46, thereby increasing the rigidity of the steering position adjusting device 60.

Further, similarly to the case of the first embodiment, at the time of the tilt operation, the reaction force against the driving force for tilting the upper tube 22 acts on the meshing portion between the switching nut 46 and the screw shaft 66, and the movable pin Only the force acting on the switch 48 prevents the switching nut 46 and the screw shaft 66 from rotating together. For this reason, it is prevented that breakage occurs due to the external force acting on the movable pin 48,
Thereby, the durability of the switching mechanism 20 is improved.

On the other hand, in the non-energized state where the solenoid 50 of the switching mechanism 20 is not energized, the switching mechanism 20 acts as a bearing for the screw shaft 66. The distance L _Ti between the coupling mechanism 20 and the connecting portion does not change, while the distance L _Te between the nut 64 and the switching mechanism 26 changes. For this reason, when the screw shaft 66 is rotated in a direction in which the distance L _Te decreases, the tilt support 16 is turned leftward in the drawing in a state where the posture of the upper tube 22 with respect to the tilt support 16 is fixed as shown in FIG. This causes the upper tube 22 to move leftward in the drawing. Further, when the screw shaft 66 is rotated in the opposite direction, the tilt support 18 is slid rightward in the drawing, whereby the upper tube 22 moves rightward in the drawing. Thus, in the non-energized state, the screw shaft 6
6, a telescopic operation in which the tilt support 18 moves right and left in the figure according to the rotation direction is realized.

In this telescopic operation, similarly to the first embodiment, the screw shaft 40 and the switching nut 4 are driven by the driving force for the tilt support 16.
6, the frictional force in the direction of relative rotation is increased. Thereby, slippage between the screw shaft 40 and the switching nut 46 is prevented, and efficient transmission of the driving force to the tilt support 16 is enabled.

Next, another embodiment of the switching mechanism according to the present invention will be described. In the following embodiment, a case where the switching mechanism is applied to the steering position adjusting device 10 will be described.
Applies exactly the same way. First, a switching mechanism 100 that is a second embodiment of the switching mechanism according to the present invention will be described with reference to FIGS. FIG. 12 shows the switching mechanism 100.
FIG. 3 is a cross-sectional view of the section taken along the axial direction of the screw shaft 40. FIG. 13 shows the movable pin 110 and the bolt 1
It is an expanded sectional view of 08. FIG. 14 shows a state in which the housing 42 is removed from the switching mechanism 100 of FIG.
FIG. 2 is a plan view seen from above in FIG. 15 and FIG.
6 is a cross-sectional view when the switching nut 46 and the movable pin 110 are cut along a plane including the axis of the movable pin 110, and FIG. FIG. 16 shows a state in which the movable pin 110 meshes with the tooth portion 46d. 12, the same components as those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIGS. 12 and 14, the switching mechanism 1
00 has a motor 102. A worm gear 104 is fixed to a motor shaft 102a of the motor 102. The worm gear 104 has a worm wheel 10
6 are engaged. At the center of the worm wheel 106, a rectangular opening 106a is provided. Bolt 108 has a head 108a and a leg 108b. Leg 108
“b” is formed in a prismatic shape having a rectangular cross section that can be fitted into the rectangular opening 106 a of the worm wheel 106. The bolt 108 is connected to the worm wheel 106 so as to be relatively displaceable in the axial direction and to transmit rotation about the axis by fitting the leg 108b into the rectangular opening 106a. On the other hand, the head 108a of the bolt 108
Is formed in a cylindrical shape, and a thread is provided on an outer peripheral surface thereof. A screw thread on the outer peripheral surface of the head 108a is screwed into a screw hole 42e provided in the housing 42.

A movable pin 110 is provided inside the screw hole 42e of the housing 42 above the bolt 108 in FIG.
Are arranged. As shown in FIG.
Has a through hole 110a penetrating in the axial direction. The through hole 110a has a step such that the upper side in FIG. 13 has a large diameter. One end of the bolt 10 is inserted into the through hole 110a.
The retaining pin 112 connected to the head 108a of the eighth pin 108 penetrates. The other end of the retaining pin 112 has a retaining portion 11 formed with a larger diameter than the smaller diameter side of the through hole 110a.
2a is provided. The tip of the movable pin 110 is chamfered so that no interference occurs when the tip of the movable pin 110 meshes with the teeth 46 d of the switching nut 46. Also, the movable pin 110 and the head 1 of the bolt 108 inside the housing 42.
08a is provided with a spring 114.

According to the configuration of the switching mechanism 100, the rotation of the motor shaft 102a is reduced in speed via the worm gear 104 and transmitted to the worm wheel 106. As described above, the bolt 108 is connected to the worm wheel 1
06 is connected so as to be relatively displaceable in the axial direction and to transmit rotation about the axis. Therefore, the rotation of the worm gear 106 is transmitted to the bolt 108, and the bolt 108 is displaced in the screw hole 42e of the housing 42 in a direction corresponding to the rotation direction. When the bolt 108 is displaced in a direction toward the switching nut 46 (hereinafter, referred to as a forward direction), the movable pin 110 is displaced toward the switching nut 46 via the spring 114. When the displacement amount of the movable pin 110 reaches a predetermined amount, the movable pin 110 is moved to the tooth portion 46 d of the switching nut 46 as shown in FIG.
Meshes with Thereby, the rotation of the switching nut 46 is blocked by the movable pin 110, and the switching nut 46 is locked. The movable pin 110 is connected to the tooth 46a of the switching nut 46.
Is completely engaged with the motor 102, an overcurrent occurs due to an increase in the load on the motor 102, and the motor 102 is stopped by detecting the overcurrent.

On the other hand, when the bolt 108 is displaced in a direction opposite to the forward direction (hereinafter, referred to as a backward direction), the movable pin 110 becomes a retaining portion 112a of the retaining pin 112.
As a result, the switching nut 46 is displaced in a direction to be separated from the tooth portion 46a. Thereby, the lock of the switching nut 46 by the movable pin 110 is released. As described above, in the present embodiment, locking and unlocking of the switching nut 46 can be realized by displacing the bolt 108 in the forward or backward direction according to the rotation direction of the motor 102.

When the movable pin 110 is displaced in the forward direction in order to lock the switching nut 46, depending on the positional relationship between the tooth 46a of the switching nut 46 and the movable pin 110, as shown in FIG. 110 is tooth 4
The rotation of the switching nut 46 may stop while riding on the mountain of 6d. In this case, since the movable pin 110 is urged toward the tooth portion 46a by the spring 114, when the switching nut 46 starts rotating next, the movable pin 110 moves to the valley adjacent to the crest on which the tooth portion 46d rides. The switching nut 46 is automatically locked. Thus, in the present embodiment, the movable pin 110
Is urged toward the switching nut 46 by the spring 114, so that the switching nut 46 can be reliably locked even when the movable pin 110 stops riding on the mountain of the tooth portion 46a. It has been.

As in this embodiment, instead of providing a spring 114 for urging the movable pin 110 between the bolt 108 and the movable pin 110, the bolt 108 and the movable pin 110 are directly connected, and the screw shaft 40 is When the rotation is started, that is, when the switching nut 46 starts rotating together, the movable nut 110 is slightly displaced in the forward direction, so that the switching nut 46 can be reliably locked. That is, by providing a means for urging the movable pin 110 in the forward direction when the switching nut 46 starts to rotate, the locking of the switching nut 46 can be ensured.

In the switching mechanism 20 described above,
When the switching nut 46 is locked, the movable pin 48
Is urged toward the switching nut 46 by the solenoid 50, so that the same effect as the above-described urging means is provided. Next, a switching mechanism 150 which is a third embodiment of the switching mechanism according to the present invention will be described with reference to FIGS. FIG. 18 is a cross-sectional view when the switching mechanism 150 is cut along the axial direction of the shaft 40. FIG. 19 is a diagram showing a state in which the switching nut 166 is locked in FIG. In addition,
18 and 19, the same components as those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted. Also,
FIG. 20 is a front view of the switching nut 166 as viewed from the right in FIG.

As shown in FIG. 18, in the present embodiment, the switching nut 16 is
6 are supported. The fixed portion of the bearing 44 to the housing 152 and the fixed portion of the switching nut 166 to the bearing 44 are the same as in the case of the switching mechanism 20 of the above-described embodiment, and a description thereof will be omitted. In this embodiment,
The housing 152 has a pin hole 152a extending parallel to the screw shaft 40. An operating nut 154 is provided in the pin hole 152a so as to be slidable in the axial direction and to prevent rotation around the axis. The operating nut 154 is a cylindrical member having one end (the right end in FIG. 19) closed, and has a thread on its inner peripheral surface. An outer peripheral surface of a bolt 158 fixed to a motor shaft 156 a of the motor 156 is screwed into a thread on an inner peripheral surface of the operation nut 154.

The operating nut 154 inside the pin hole 152a
A movable pin 160 is provided on the right side in FIG. Similar to the movable pin 110 shown in FIG. 13, the movable pin 160 includes a through hole 160a that penetrates in the axial direction and has a step with a large diameter on the right side in FIG. Through hole 16
A retaining pin 162, one end of which is connected to the closed end face of the operation nut 154, penetrates through 0a. The other end of the retaining pin 162 is provided with a retaining portion 162a formed to have a larger diameter than the smaller diameter side of the through hole 110a.
A spring 164 is provided in a portion between the movable pin 160 and the operation nut 154 inside the pin hole 152a of the housing 152.

The switching nut 166 has a disk-shaped flange portion 166a at one end (the right end in FIG. 18).
A plurality of lock holes 166b are formed in the flange 166a at equal intervals in the circumferential direction. When the switching nut 166 rotates, the lock hole 166b is sequentially inserted in the housing 15.
It is provided so as to face the second pin hole 152a.

According to the structure of the switching mechanism 150, when the motor 156 is driven, the rotation of the shaft 156a is transmitted to the bolt 158, and the operating nut 154 moves in the pin hole 152a in FIG. Displaced left and right. When the operation nut 154 is displaced in the direction toward the flange portion 166a of the switching nut 166 (hereinafter, referred to as the forward direction), the movable pin 160 is displaced in the forward direction via the spring 164. And this movable pin 1
When the displacement amount of 60 reaches a predetermined amount, as shown in FIG.
The tip of the movable pin 166 is inserted into the lock hole 166b of the switching nut 166. Thereby, the switching nut 166
Is prevented by the movable pin 166 and the switching nut 1
66 is locked. The movable pin 110 has the lock hole 166
When inserted to the maximum, the load on the motor 156 increases and an overcurrent occurs, and the motor 156 is stopped by detecting the overcurrent.

On the other hand, when the operation nut 154 is displaced in a direction opposite to the forward direction (hereinafter, referred to as a backward direction), the movable pin 160
By 2a, the switching nut 166 is displaced in a direction to be separated from the lock hole 166b. Thus, the locked state of the switching nut 166 is released. in this way,
In the present embodiment, locking and unlocking of the switching nut 166 can be realized by displacing the operating nut 154 in the forward or backward direction according to the rotation direction of the motor 156.

In the switching mechanism 150 of this embodiment, similarly to the switching mechanism 100, the movable pin 16
0 is urged by the spring 164 in the direction for locking the switching nut 166, so that even when the movable pin 160 stops while riding on the gap between the locking holes 166b, the switching nut 166 is reliably locked. It is possible.

Incidentally, as described above, the switching nut 166 is used.
Is prevented by inserting the movable pin 160 into the lock hole 166b. Therefore, the switching nut 166
Is locked, the screw shaft 4
A reaction force against the rotation torque transmitted from 0 to the switching nut 166 acts between the movable pin 160 and the lock hole 166b. To release the lock of the switching nut 166, the movable pin 160
Must be driven in the reverse direction. Therefore, as the reaction force increases, the force to be applied to the movable pin 160 to unlock the switching nut 166 increases, and a higher output is required of the motor 156.

On the other hand, in this embodiment, the lock hole 166b is provided with the flange portion 166b of the switching nut 166.
, The distance between the engagement portion between the lock hole 166b and the movable pin 160 and the rotation axis of the screw shaft 40 is increased. When the rotational torque transmitted from the screw shaft 40 to the switching nut 166 is constant, the force acting between the movable pin 160 and the lock hole 166b decreases as the distance increases. Therefore, the force required to unlock the switching nut 166 is reduced, and the output required of the motor 156 is suppressed. Thus, the switching mechanism 150 of the present embodiment
In, the size of the motor 156 is reduced by suppressing the output required for the motor 156.

Next, a switching mechanism 200 as a fourth embodiment of the switching mechanism according to the present invention will be described with reference to FIGS. FIG. 21 is a perspective view of the switching mechanism 200. As shown in FIG. 21, the housing 2 of the switching mechanism 200
A switching nut 206 is supported at 02 via a bearing 204 so as to be rotatable about the axis and in a state where relative displacement in the axial direction is prevented. The switching nut 206 has a screw portion on the inner peripheral surface thereof and a tooth portion 206a formed with a plurality of teeth formed at an equal pitch on the outer peripheral surface, similarly to the switching nut 46 of the switching mechanism 20 described above. I have. A screw shaft 40 is screwed into a screw portion on the inner peripheral surface of the switching nut 206.

The switching arm 2 is located above the switching nut 206.
08 is provided. FIG. 22 shows the switching arm 208 and the switching nut 206 as viewed from the near side in the axial direction diagram 21 of the screw shaft 44. As shown in FIGS. 21 and 22, the switching arm 208 is rotatably supported by an arm shaft 210 at one end (the left end in FIG. 22). Then, the switching arm 208 is moved by the torsion spring 212 to the tooth portion 2 of the switching nut 206.
06a. The switching arm 208 includes a lock pin 208a provided to face the tooth portion 206b of the switching nut 206.

A slider 214 is provided near the other end (right end in FIG. 22) of the switching arm 208. FIG. 23 shows a view of the slider 214 as viewed from the right in FIG. As shown in FIGS. 22 and 23, the slider 214
Is a rectangular planar member provided with a slider groove 214a. The slider groove 214a is provided with an inclined portion 214b inclined from the lower left to the upper right in FIG. In the state shown in FIG. 22, when the switching arm 208 is biased by the torsion spring 212 as described above, the right end of the switching arm 208 in the figure is pressed toward the inclined portion 214b of the slider groove 214a.

On the upper side of the slider 214 in FIG. 23, a screw portion 214c is provided. Screw part 214
Are formed such that a cross section in a direction perpendicular to the axis becomes a semicircle. A slider drive screw 216 is screwed into the screw portion 214c of the slider 214. The slider 214 is located near the lower side in FIG.
Guided by a guide shaft 218. The slider drive screw 216 and the guide shaft 218 are both provided parallel to the screw shaft 40. As described above, since the screw portion 214c of the slider 214 is formed in a semicircular shape, the slider driving screw 2c is formed.
16 can be displaced in a direction away from the screw portion 214c. Thereby, the slider drive screw 2
When an error occurs in the parallelism between the guide shaft 216 and the guide shaft 218, a change in the distance between the two can be absorbed.

As shown in FIG. 21, the slider driving screw 2
A spur gear 220 is fixed to one end (the front end in FIG. 21) of 16. The spur gear 220 meshes with a gear 224 fixed to a motor shaft 222 a of a motor 222. According to the configuration of the switching mechanism 200, when the motor 222 is driven, the rotation of the motor shaft 222a is transmitted to the slider driving screw 216 while being reduced by the gear 224 and the spur gear 224. The rotation of the slider drive screw 216 drives the slider 214 in a direction corresponding to the rotation direction of the motor shaft 22a. As described above, one end of the switching arm 208 is pressed toward the inclined portion 214b of the slider groove 214b provided in the slider 214. For this reason, even when the slider 214 is driven as described above, the state where the switching arm 208 and the inclined portion 214b are engaged is maintained. Therefore, when the slider 214 is driven rightward in FIG. 23, the switching arm 208 rotates toward the switching nut 206. On the other hand, when the slider 214 is driven leftward in FIG. Nut 20
6 in a direction away from 6. Therefore, according to the driving direction of the motor 222, the lock pin 208 a of the switching arm 208 meshes with the tooth portion 206 a to lock the switching nut 206 and the lock pin 2.
A state in which the lock of the switching nut 206 is released by the release of the 08a from the tooth portion 206a is realized.

By the way, the tooth portion 206 of the switching nut 206
a and the lock pin 208a of the switching arm 208 can be regarded as constituting a ratchet mechanism. That is, even when the lock pin 208a is in mesh with the tooth portion 206a, when a rotational torque acting on the switching nut 206 overcomes the urging force of the switching arm 208 toward the switching nut 206, the lock pin 280a is turned on. The switching nut 206 rotates while getting over the tooth portion 206a. In this embodiment, in order to prevent the rotation of the switching nut 206, the urging force of the torsion spring 212 is provided sufficiently large. However, when the urging force of the torsion spring 212 increases,
The force required to rotate the switching arm 208 in a direction to separate from the switching nut 206, that is, the force to be applied to the switching arm 208 to unlock the switching nut 206 increases.

On the other hand, in the present embodiment, the rotation of the motor 222 is reduced by the set of the gear 224 and the spur gear 220, and then the rotation of the slider drive shaft 216 is performed.
After being decelerated by a set of the screw portion 214c of the slider 214, the inclined portion 214 of the slider groove 214a is further reduced.
The speed is reduced by b and transmitted to the switching arm 208. Thus, the output of the motor 222 is reduced in three stages and transmitted to the switching arm 208, so that a large reduction ratio is obtained. Therefore, in the present embodiment, it is possible to drive the switching arm 208 against a large urging force of the torsion spring 212 by using the motor 222 having a relatively small output.

Further, since the switching mechanism according to the present invention is provided in the driver's cab, it is required to reduce the size of the switching mechanism from the viewpoint of enhancing the driver's comfort. On the other hand, in the switching mechanism 200 of the present embodiment, the motor 222 is arranged such that the motor shaft 222a is parallel to the screw shaft 40 and is arranged side by side with the arm shaft 210 and the slider driving screw 216. It is arranged in. For this reason, the motor 222 can be provided between the arm shaft 210 and the slider drive screw 216, and as a result, the switching mechanism 2
00 has been realized.

When the switching nut 206 is locked, a reaction force against the rotational torque transmitted from the screw shaft 40 to the switching nut 206 acts between the lock pin 208a of the switching arm 208 and the tooth portion 206a. doing. The direction of the reaction force is substantially perpendicular to the moving direction of the lock pin 208a of the switching nut 206.
For this reason, when the lock pin 208a is directly driven by the screw mechanism, the screw mechanism may be twisted, preventing the smooth operation of the switching mechanism.

On the other hand, in the present embodiment, the transmission of the force between the slider driving screw 216 and the switching arm 208 is performed by the slider groove 2 provided in the slider 214.
This is performed via an engaging portion between the inclined portion 214b of 14a and the switching arm 208. For this reason, the slider drive screw 2
16 and the switching arm 208, the slider 2
14, that is, the tooth portion 206a and the lock pin 2
08a is not transmitted, and no external force that causes the slider drive screw 216 to twist is applied. Thus, in the switching mechanism 200 of the present embodiment, the slider driving screw 21
6 is prevented from occurring, whereby a smooth operation of the switching mechanism 200 is realized.

In this embodiment, as described above,
The switching arm 208 is urged toward the switching nut 206 by the torsion spring 212, so that the rotation of the screw shaft 40 is stopped in a state where the lock pin 208a of the switching arm 208 rides on the peak of the tooth portion 206a of the switching nut 206. Then, when the rotation of the screw shaft 40 is started, the lock pin 20
8a meshes with the valley adjacent to the crest of the tooth portion 206a. Therefore, also in the switching mechanism 200 of the present embodiment,
As with the switching mechanisms 20, 100, and 150, the switching nut 206 can be reliably locked.

Further, in the switching mechanism 200 of the present embodiment, similarly to the switching mechanisms 20, 100 and 150, when the switching nut 206 is locked, the switching pin 206a of the switching arm 208 is attached to the switching nut 206. Only the force for preventing co-rotation of the lock pin 208a acts, and no external force acts on the lock pin 208a when the lock is released. Therefore,
Also in the present embodiment, the lock pin 208a is prevented from being damaged, thereby improving the durability of the switching mechanism 200.

In the above-described embodiment, the hooks joint 38 is provided with the bearings 44, 2
04 is the support means described above, the valleys of the teeth 46d and 206a, and the lock hole 166b are in the recesses of the rotation prevention means described above, and the movable pins 48, 110, 160 and the lock pin 208a are the The pins 114 and the springs 114 and 164 and the torsion spring 112 correspond to the above-mentioned urging means, respectively.

Next, a switching mechanism 300 as a fifth embodiment of the switching mechanism according to the present invention will be described with reference to FIGS. 24 and 25. FIG. 24 shows the switching mechanism 300
It is sectional drawing at the time of cutting along the axial direction of 0. Also,
FIG. 25 is a cross-sectional view when the switching mechanism 300 is cut along the line XXV-XXV shown in FIG. As shown in FIGS. 24 and 25, the switching mechanism 300 includes a housing 302. The housing 302 is vertically swingably connected to the tilt support 16. The housing 302 is a substantially cylindrical member having one end (the right end in FIG. 24) closed.
An opening 302a is provided on the closed end surface. The housing 302 is disposed around the screw shaft 40 so that the screw shaft 40 passes through the opening 302a.

The housing 302 has an engagement protrusion 302b on its inner peripheral surface. The outer race of the bearing 304 is press-fitted into the inner peripheral surface of the housing 302 from the left side in FIG. A circlip 306 is fitted on the inner peripheral surface of the housing 302 so as to engage with the other end surface of the outer race of the bearing 304. As described above, the outer race of the bearing 304 is sandwiched between the engagement protrusion 302b and the circlip 306, so that the housing 3
The displacement relative to 02 is prevented.

A switching nut 308 is provided inside the housing 302. The switching nut 308 is screwed to the screw shaft 40. The switching nut 308 includes a small-diameter portion 308a and a large-diameter portion 308b provided on the right side in FIG. 24 of the small-diameter portion 308a. The right end of the switching nut 308 in FIG. 24 has a worm wheel 308c formed to have a larger diameter than the large diameter portion 308b.
Are provided coaxially and integrally with the switching nut 308.

A step 308d is formed at the boundary between the small diameter portion 308a and the large diameter portion 308b of the switching nut 308. The small diameter portion 308a of the switching nut 308 is
24, the step 308d is pressed into the inner race of the bearing 304 until it contacts the right end surface of the inner race of the bearing 304 in FIG. Further, a fixing nut 310 is screwed to the left end of the small diameter portion 308a in FIG. 24 until it comes into contact with the left end surface of the inner race of the bearing 304 in the drawing. Thus, the relative displacement of the switching nut 308 in the axial direction with respect to the bearing 304 is prevented. Therefore, the switching nut 308 is rotatably supported around the axis in a state where relative displacement in the axial direction with respect to the housing 302 is prevented.

A worm gear 312 meshes with the worm wheel 308c. The worm gear 312 is disposed so that its axial direction is oriented in a tangential direction of the worm wheel 312. As shown in FIG.
2 has journal portions 312a at both ends. The worm gear 312 is rotatably supported by a bearing 314 in a journal portion 312 a around an axis, and is connected to a shaft of a switching motor 316 fixed to the housing 302. The reduction ratio when the rotation is transmitted from the worm gear 312 to the worm wheel 308c is set to a predetermined value 1 / R. The inclination of the tooth surfaces of the worm wheel 308c and the worm gear 312 is as follows.
The rotation is set so as not to be transmitted from the worm wheel 308c to the worm gear 312.

According to the configuration of the switching mechanism 300, the rotation of the worm wheel 308c is not transmitted to the worm wheel 312 when the switching motor 316 is stopped. That is, the rotation of the worm wheel 308 c is locked by the worm gear 312.
Therefore, when the screw shaft 40 rotates,
The switching nut 308 is prevented from rotating together with the screw shaft 40. Therefore, when the switching motor 316 is stopped, the switching nut 308 acts as a nut on the screw shaft 40, and the tilt operation is realized by changing the distance L _Ti .

On the other hand, when the switching motor 316 is driven, the worm gear 312 rotates.
8c. That is, when the switching motor 316
_When driven at _M , the worm wheel 308c rotates at a rotation speed N _M / R. Therefore, when the screw shaft 40 rotates, the rotation speed N _S of the screw shaft 40 and the rotation speed N _M /
When R and the rotation direction coincide with each other, the switching nut 308
Rotates together with the screw shaft 40. Therefore, in this case, the switching mechanism 300 acts as a bearing for the screw shaft 40, and the telescopic operation is realized by changing the distance L _Te . Thus, according to the switching mechanism 300 of the present embodiment, the switching motor 3
16 while the screw shaft 40 is tilt operation is realized by being rotated while is stopped, the switching motor 31 with respect to the rotational speed N _M of the screw shaft 40
The telescopic operation is realized by driving the motor 6 at the rotation speed N _M / R.

Incidentally, a frictional force exists in the rotational direction between the screw shaft 40 and the switching nut 308. Therefore, in order to rotate the switching nut 308 relative to the screw shaft 40, the screw shaft 4
0 and the maximum static friction torque T _s between the switching nut 308
Must be applied to the switching nut 308. Therefore, be driven switching motor 316 so that the rotational speed N _M / R of the worm wheel 308c is larger than the rotational speed N _S of the screw shaft 40, the rotational torque applied to the worm wheel 308c still smaller than the friction torque T _s, never relative rotation occurs between the switching nut 308 and the screw shaft 40, both will continue to co-rotation.

_Assuming that the rotation torque of the switching motor 312 is T _M , the rotation torque applied to the worm wheel 308c is T _M · R. Therefore, assuming that the command value of the number of revolutions for the switching motor 312 is N _M ^C , N _M ^C / R> N _S (1) and T _M R <T _S (2) are satisfied. When the switching motor 312 is driven as described above, the rotation speed N _M / R of the worm wheel 308c matches the rotation speed N _s of the screw shaft 40. Therefore, in the present embodiment, the rotation speed of the switching motor is set to N _m / R
It is not necessary to control precisely to match,
By using the switching motor 312 having a torque characteristic that satisfies the expression (2) and setting the command value N _M ^C of the rotation speed for the switching motor 312 so as to satisfy the expression (1), the worm wheel is used. Rotational speed N _{M of} 308c
/ A rotational speed N _s of the R and the screw shaft 40 can be matched.

As described above, the switching mechanism 3 of this embodiment is
00 is the worm wheel 308c and the worm gear 31
2 to lock the switching nut 308. In this regard, the switching mechanism 20 of the above embodiment,
The configuration is different from the configuration in which the switching nut is locked by the engagement of the movable pin and the switching nut as in 100, 150, and 200. Due to such a difference in the configuration, the switching mechanism 300 of the present embodiment is different from the switching mechanism 20, 100,
It has further improved performance compared to 150 and 200. Hereinafter, representatively, the superior performance of the switching mechanism 300 of the present embodiment as compared with the switching mechanism 100 will be described.

That is, the switching mechanism 100 is provided with a bolt 108 for converting the rotation of the motor 102 into a linear motion of the movable pin and a spring 114 for ensuring locking of the switching nut 46. In the housing 42, a screw hole 42e screwed with the bolt 108 is provided.
Has been processed. On the other hand, in the switching mechanism 300 of the present embodiment, since the movable pin is eliminated,
A bolt for realizing the linear movement of the movable pin is also eliminated, and accordingly, it is not necessary to form a screw hole in the housing 302. In the switching mechanism 300, the worm wheel 308c and the worm gear 312
Is always engaged. Therefore, the worm wheel 3
08c and the worm gear 312 cannot be stopped in an incomplete meshing state, and it is not necessary to provide a means such as a spring for securely locking the switching nut 308. As described above, in the switching mechanism 300 according to the present embodiment, cost reduction and space saving are achieved by reducing the number of components, and it is not necessary to form a screw hole in the housing 302. The processing cost is reduced, and the cost is further reduced.

In the switching mechanism 100, when switching between the tilt operation and the telescopic operation, the movable pin 110 is moved between the position where the movable pin 110 meshes with the tooth portion 46d of the switching nut 46 and the position where the movable pin 110 is disengaged from the tooth portion 46d. It will take time to move. On the other hand, in the switching mechanism 300 of the present embodiment, the tilting operation is realized by stopping the switching motor 316, while the telescopic operation is realized by driving the switching motor 316. That is, the time required for this switching is suppressed to substantially zero by switching between the tilt operation and the telescopic operation by stopping and driving the switching motor 316. Thus, in this embodiment,
A switching mechanism 300 capable of switching between a tilt operation and a telescopic operation with high responsiveness is realized.

In the switching mechanism 100, the operation sound generated when switching between the tilt operation and the telescopic operation is generated by the motor 102 and the worm wheel 106.
Between the bolt 108 and the bolt 108, the bolt 108 and the screw hole 42
e, the movable pin 110 and the switching nut 46
This occurs from a total of four positions of meshing portions with the tooth portions 46d. On the other hand, in the switching mechanism 300 according to the present embodiment, during the telescopic operation, the motor 316 main body and the two meshing portions of the worm wheel 308 c and the worm gear 312 are engaged.
Only the operating noise is generated from the location, and the switching mechanism 1
The operation sound is suppressed as compared with 00. As described above, the switching mechanism 300 of this embodiment has excellent characteristics in terms of quietness.

When adjusting the position of the steering wheel, the driver often tries to gradually set the steering wheel to a desired position while alternately repeating the tilt operation and the telescopic operation. In such a case, the switching mechanism 10
According to 0, the motor 102 is driven every time the tilt operation and the telescopic operation are switched, and the power consumption increases. On the other hand, according to the switching mechanism 300 of the present embodiment, the switching motor 316 is driven only during the telescopic operation, and the switching motor 316 is not driven during the tilt operation. The power consumption in the case of repeating the above is suppressed. As described above, the switching mechanism 300 according to the present embodiment has excellent characteristics in saving power consumption.

Further, according to the switching mechanism 100, at the time of tilting operation, a force corresponding to a torque for preventing the movable pin 110 from rotating together with the screw shaft 40 and the switching nut 46 is applied to the axis of the movable pin 110. Acts perpendicular to the direction. Although the force is small, the bolt 108 and the screw hole 42e
There is no possibility that prying will occur between them. On the other hand, in the switching mechanism 300 of the present embodiment, the torque for preventing the screw shaft 40 and the switching nut 308 from rotating together is supplied from the worm wheel 308 c to the worm gear 312 via the tooth surface, and the worm gear 3
12 is transmitted as a force in the rotational direction and the axial direction. That is, since no force acts on the worm gear 312 in a direction perpendicular to the axis thereof, the possibility of occurrence of a twist between the worm gear 312 and the bearing 314 is eliminated. As described above, according to the switching mechanism 300 of the present embodiment, switching between the tilt operation and the telescopic operation can be performed with higher reliability.

Next, a switching mechanism 350 which is a sixth embodiment of the switching mechanism according to the present invention will be described with reference to FIGS. FIG. 26 is a cross-sectional view when the switching mechanism 350 is cut along the axial direction of the screw shaft 40. FIG. 27 is a view when viewed from the direction of arrow XXVII shown in FIG. FIG. 28 is a graph showing a straight line XXVIII shown in FIG.
It is an expanded sectional view at the time of cutting along -XXVIII. 26 to 28, the same components as those in FIG. 18 are denoted by the same reference numerals, and description thereof will be omitted. The switching mechanism 350 according to the present embodiment is generally configured by using a solenoid instead of the motor 156 in the switching mechanism 150 according to the third embodiment.

As shown in FIG. 26, in the switching mechanism 350, the switching nut 166 is rotatably supported inside the housing 354 by a pair of bearings 352. The switching mechanism 350 also includes a plunger 356. The plunger 356 is a member made of a magnetic material. The plunger 356 is slidably supported by the bush 358 in a direction substantially parallel to the axial direction of the screw shaft 40.

A solenoid 3 is provided on the outer periphery of the housing 354.
60 is fixed. The solenoid 360 has an electromagnetic coil 362. When energized, the electromagnetic coil 362 generates an electromagnetic attraction force that pulls the plunger 356 into the interior thereof. Further, the solenoid 360 is provided with a spring 364 for urging the plunger 356 toward the flange portion 166a of the switching nut 166. For this reason, when the electromagnetic coil 362 is not energized, the plunger 356 is displaced toward the flange portion 166a and locks the switching nut 166 by engaging with the lock hole 166b of the switching nut 166. on the other hand,
When the electromagnetic coil 362 is energized, an electromagnetic attraction force is applied to the plunger 356, and the plunger 356 is displaced in a direction to separate from the lock hole 166 b against the urging force of the spring 364, thereby locking the switching nut 166. To release.

As described above, in the switching mechanism 350 of this embodiment, the switching nut 166 can be locked and unlocked by switching between energizing and de-energizing the electromagnetic coil 362 of the solenoid 360. Thus, the switching between the tilt operation and the telescopic operation of the steering position adjusting device can be realized. Next, a switching mechanism 400 which is a seventh embodiment of the switching mechanism according to the present invention will be described. Switching mechanism 400 of the present embodiment
The magnitude of the driving force to be applied to the plunger (or the movable pin) for unlocking the switching nut in comparison with the switching mechanism 350 of the sixth embodiment and the switching mechanism 150 of the third embodiment. Is characterized in that the switching mechanism can be reduced in size and cost.

That is, for example, in the switching mechanism 350 of the sixth embodiment, when the switching nut 166 is not locked, the screw shaft 40 and the switching nut 1
Rotational torque is transmitted from the screw shaft 40 to the switching nut 166 due to friction between the switching nut 166 and the switching nut 166. Hereinafter, the torque transmitted from the screw shaft 40 to the switching nut 166 is referred to as co-rotating torque T. On the other hand, when the switching nut 166 is locked, the switching nut 1
66 is prevented by the plunger 356,
A reaction force against the co-rotating torque T acts on the plunger 356 from the lock hole 166b. Due to the force acting on the plunger 356 from the lock hole 166b, it is necessary to apply a large electromagnetic force to the plunger 356 in order to release the plunger 356 from the lock hole 166b.

As shown in FIG. 27, the screw shaft 4
Assuming that the distance between the center axis of the switching nut 166 and the lock hole 166b of the switching nut 166 is r, when the co-rotation torque T is transmitted to the switching nut 166 while the switching nut 166 is locked, the locking hole 166b From above, the force F ₀ acting on the plunger 356 is expressed by the following equation. F ₀ = T / r (3) The direction of the force F ₀ acting on the plunger 356 corresponds to the rotation direction of the switching nut 166, and therefore, the plunger 3
The direction becomes substantially perpendicular to the displacement direction of 56. Hereinafter, the force F ₀ acting on the plunger 356 as a reaction force to the co-rotating torque T is referred to as “torsion force”. Such torsional force F
₀ acts on the plunger 356 and the plunger 35
6 is displaced, as shown in FIG.
6, frictional forces μ ₁ · F and μ ₂ · F act from the lock hole 166b and the bush 358, respectively. However, mu ₁ and mu ₂ are respectively a coefficient of friction between the plunger 356 and the locking hole 166b and the bushing 358. Therefore, in order to disengage the plunger 356 from the lock hole 166b to unlock the switch nut 166, the friction force μ ₁ · F ₀ in addition to the biasing force F _s which spring 364 is emitted, and μ ₂ · F ₀ In opposition, the plunger 356 must be displaced. That is, in order to unlock the switching nut 166, the electromagnetic coil 36
Electromagnetic attraction force to be applied from the 2 to the plunger 356 F _r will be expressed by the following equation.

F _r = F _s + (μ ₁ + μ ₂ ) · F ₀ = F _s + (μ ₁ + μ ₂ ) · (T / r) (4) It is expressed by the above equation (3). The torsional force F ₀ is a force acting on the plunger 356 in a state where the co-rotating torque T is applied to the switching nut 166, that is, in a state where the screw shaft 40 is rotating. However, after the rotation of the screw shaft 40 is also stopped, the plunger 356 torsional force F ₀ with a range of up to (3) is likely to continue to act. Therefore, in order to reliably disengage the plunger 356 from the locking hole 166b, the plunger 3 an electromagnetic attraction force F _r represented by the equation (4)
It is necessary to act on 56.

As described above, the switching mechanism 350 of the sixth embodiment is used.
In the state where the switching nut 166 is locked,
Friction force (μ ₁ +) on plunger 356 with torsional force F ₀
μ ₂ ) · F ₀ acts, and due to this frictional force, the electromagnetic coil 362 is used to unlock the switching nut 166.
Electromagnetic attracting force F _r to be applied to the plunger 356 from increases by _{(μ 1 + μ 2) ·} F 0. As a result, the size and cost of the solenoid 360 are increased.

Electromagnetic attractive force to be applied to plunger 356
F_r356 and lock hole 1
It is conceivable to form the engagement surface with 66b in a tapered shape.
You. FIG. 29 shows the plunger 356 and the lock hole 166b.
When the engaging surface is formed in a tapered shape with an inclination angle α / 2
FIG. 28 is a sectional view similar to 28. As shown in FIG.
By forming the mating surface in a tapered shape, the plunger 356 is formed.
Torsional force F acting on₀Locks the plunger 356
Component F in a direction to separate from 166b_k(= F ₀・ Ta
n (α / 2)). Therefore, the plunger 35
Plunger to release 6 from lock hole 166b
Electromagnetic attraction force F to be applied to 356_rIs F _kOnly decrease
Will be.

However, in this case, the plunger 35
In a state where the twisting force F ₀ is applied to 6, in order to lock the switching nut 166 by the plunger 356, it is necessary for urging the lock hole 166b of the plunger 356 against the component F _k. Therefore, the urging force F _S of the spring 364 must satisfy the following equation.

F _S > F _k − (μ ₁ + μ ₂ ) · F ₀ (5) In the equation (5), the friction coefficients μ ₁ and μ ₂ are the temperature and the surface state of the plunger 356 and the lock hole 166b. Therefore, in order to reliably lock the switching nut 166 by the plunger 356, the equation (5) must be satisfied even if μ ₁ and μ ₂ are zero. Therefore, the urging force F _S must satisfy the following equation.

F _S > F _k (6) As described above, when the engagement surface between the plunger 356 and the lock hole 166b is formed in a tapered shape, the spring 36
It is necessary to secure the urging force F _S of No. 4 at least to a value larger than F _k . On the other hand, as can be seen from equation (4), when the urging force F _S increases, the electromagnetic attraction force _Fr also increases. Therefore, the result, even when forming the engagement surface tapering, can not be sufficiently reduced for the electromagnetic attracting force F _r required to withdraw the plunger 356 from the lock hole 166b.

On the other hand, the switching mechanism 400 of this embodiment
According to this, the reaction force against the co-rotating torque T is prevented from acting on the plunger 356 in a state where the switching nut is locked, so that the size and cost of the solenoid 360 can be reduced. Hereinafter, the configuration and operation of the switching mechanism 400 of the present embodiment will be described with reference to FIGS.

FIG. 30 is a cross-sectional view when the switching mechanism 400 is cut along the axial direction of the screw shaft 40. FIG. 31 is a diagram when the switching mechanism 400 is viewed from the direction of the arrow XXXI shown in FIG. The switching mechanism 400 of this embodiment is realized by using the switching nut 402 instead of the switching nut 166 in the switching mechanism 350 of the sixth embodiment. The components other than the switching nut are the same as those of the switching mechanism 350 of the sixth embodiment, and a description thereof will be omitted.

As shown in FIG. 30, a switching nut 402 has a disk-shaped flange portion 402a at one end (the right end in the drawing).
It has. As shown in FIG. 31, the flange portion 402a
Has a plurality of lock holes 402b formed at equal intervals in the circumferential direction. The lock hole 402b is arranged so as to sequentially face the plunger 356 when the switching nut 402 rotates. Each lock hole 402b has a central angle β in a circumferential direction about the rotation center of the switching nut 402.
Is formed in the shape of a long hole extending over the range. Therefore, in a state where the plunger 356 has entered the lock hole 402b, the switching nut 402 can rotate within the range of the central angle β.

According to the configuration of the switching mechanism 400, when the power is supplied to the electromagnetic coil 362, the plunger 35
6 is detached from the lock hole 402b by being attracted by the electromagnetic coil 362. When the screw shaft 40 is driven to rotate in this state, the switching nut 402 rotates together with the screw shaft 40. In this case, a telescopic operation in which the tilt support 16 translates in the axial direction according to the rotation direction of the screw shaft 40 is realized.

In this state, when the power supply to the electromagnetic coil 362 is stopped, the electromagnetic attraction acting on the plunger 356 disappears.
64, the flange 40 of the switching nut 402
Displaced toward 2a. Then, the switching nut 402
When any of the lock holes 402b reaches the rotation position facing the plunger 356, the plunger 356 enters the lock hole 402b. Then, when the switching nut 402 is rotated until one end of the lock hole 402b (the end on the rear side in the rotation direction of the switching nut 402) is engaged with the plunger 356, the rotation of the switching nut 402 is thereafter performed by the plunger 356. The switching nut 402 is locked and a state in which the switching nut 402 is locked is formed. In this state, the upper tube 2 depends on the rotation direction of the screw shaft 40.
Thus, a tilt operation in which 2 tilts up and down is realized.

FIG. 31 shows that the switching nut 402 is rotated in the counterclockwise direction in FIG. 31 so that the plunger 356 enters the locking hole 402b.
Is locked. As shown in FIG. 31, the end 402 c of the lock hole 402 b on the rear side with respect to the rotation direction of the screw shaft 40 is
By engaging with 6, the switching nut 402 is locked. When the rotation of the screw shaft 40 is continued in such a state, the plunger 3 is moved from the end 402c of the lock hole 402b as described in the sixth embodiment.
Against 56, torsional force F ₀ is a reaction force against co-rotation torque T acts in a direction substantially perpendicular to the displacement direction, the torsional force F _0, even after the rotation of the screw shaft 40 is stopped It may continue to act on the plunger 356. In this case, it is necessary to apply a large electromagnetic attraction force to the plunger 356 to separate the plunger 356 from the lock hole 402b due to the frictional force associated with the torsional force F _0, and as a result, the solenoid 360 becomes larger. As described above, the cost increases.

On the other hand, the switching mechanism 400 of this embodiment
In the above, after the rotation of the screw shaft 40 is stopped in a state where the switching nut 402 is locked by the plunger 356, the screw shaft 40 is rotated by a predetermined angle θ in a direction opposite to the rotation direction up to that time. In this case, since the lock hole 402b is formed in the shape of a long hole extending in the circumferential direction, the switching nut 402 is turned in the opposite direction (FIG. 3).
1 is rotated clockwise).
6 is not blocked. Therefore, when the screw shaft 40 is rotated in the opposite direction by the predetermined angle θ, the switching nut 402 rotates together with the screw nut 40.

FIG. 32 is a view showing a state in which the switching nut 402 rotates in the opposite direction by a predetermined angle θ after the screw shaft 40 is stopped. Also, FIG.
FIG. 3 is a sectional view taken along a straight line XXXIII-XXXIII shown in FIG. As shown in FIG. 32, when the switching nut 402 rotates in the opposite direction, the plunger 356 is
02b from the end 402c. As a result, FIG.
As shown in the torsional force F ₀ exerted on the plunger 356 is eliminated, the frictional force acting from the lock hole 402b and the bushing 358 to the plunger 356 is substantially zero.

As described above, in this embodiment, when the rotation of the screw shaft 40 is stopped while the switching nut 402 is locked by the plunger 356,
It is possible to eliminate the torsional force F ₀ acting from the lock hole 402b on the plunger 356. Therefore, when the plunger 356 is disengaged from the lock hole 402b, the frictional force acting between the plunger 356, the lock hole 402b, and the bush 358 can be made substantially zero,
Thus, it is possible to reduce suppress electromagnetic attraction force F _r to be applied from the solenoid 360 to the plunger 356. Therefore, according to the switching mechanism 400 of this embodiment, the switching nut 402 can be used without increasing the size of the solenoid 360.
Is locked and only the screw shaft 40 rotates (that is, the tilt operation state), the switching nut 4
Switching to a state where 02 rotates together with the screw shaft 40 (that is, a telescopic operation state) can be reliably performed.

Note that the telescopic operation is performed while the switching nut 402 rotates reversely by the predetermined angle θ. However, the predetermined angle theta, by setting smaller within the range that can eliminate the torsional force F ₀ exerted on the plunger 356, it is possible to prevent the discomfort to the driver with the telescopic operation during reverse rotation. Also,
For the central angle β of the lock hole 402b, the switching nut 4
02 so that the plunger 356 does not engage with the end on the opposite side of the lock hole 402b even if the 02 rotates in the reverse direction by the predetermined angle θ.
What is necessary is just to set it larger than (theta).

As described above, according to the switching mechanism 400 of the present embodiment, the switching from the tilt operation to the telescopic operation can be reliably performed while the size and cost of the solenoid 360 are reduced. For this reason, together with the fact that both the tilt operation and the telescopic operation can be performed by the single motor 26, the degree of freedom in designing the steering position adjusting device is improved, and the size and cost of the steering position adjusting device are reduced. Can be achieved.

The switching mechanism 400 of this embodiment is different from the switching mechanism 350 of the sixth embodiment in that the lock holes 402
b is formed into an elongated hole, and the screw shaft 40
After the motor stops rotating, the motor 26 is rotated in the reverse direction.
Is realized only by changing a control program for controlling the control. Therefore, according to the present embodiment, the switching mechanism 350
As described above, it is possible to enjoy the above-mentioned benefits without increasing the cost.

The timing at which the screw shaft 40 is reversely rotated is not limited to immediately after the screw shaft 40 stops, and the screw shaft 40 may be reversely rotated after a predetermined period has elapsed after the screw shaft 40 has stopped.
That is, for example, when the tilt operation in the same direction is intermittently repeated at short time intervals, if the screw shaft 40 is rotated in the reverse direction each time each tilt operation is completed, the tilt operation is started until the next tilt operation is started. There will be a delay. Therefore, in such a case, after the end of the tilt operation, the screw shaft 40 is rotated reversely at a point in time when it is determined that the next tilt operation is not performed, thereby delaying the start of the tilt operation. Can be prevented.

In the seventh embodiment, the plunger 356 is driven by the solenoid 360. However, the present invention is not limited to this. The plunger 356 may be driven by a motor and a screw as in the third embodiment. Good. In addition, any known driving means may be used as the plunger 356.
Can be used for driving. In the seventh embodiment, the plunger 356 corresponds to the movable pin described in claim 5, the lock hole 166b corresponds to the recess described in claim 5, and the switching nut 166 is locked. After the rotation of the screw shaft 40 is stopped in the retracted state, the screw shaft 40 is reversely rotated, thereby realizing the reverse rotation means described in claim 5.

[0114]

As described above, according to the first aspect of the present invention, the force acting on the rotation preventing means of the switching mechanism is suppressed to a force sufficient to prevent the switching nut and the screw shaft from rotating together. Can be. Thereby, the durability of the switching mechanism can be improved.

Further, according to the second aspect of the invention, the rotation of the switching nut by the rotation preventing means can be reliably prevented. According to the third aspect of the invention, the rigidity of the steering position adjusting device can be improved. Further, according to the invention, the number of components of the switching mechanism can be reduced, and the switching operation of the switching mechanism can be realized with high responsiveness.

According to the fifth aspect of the present invention, after the relative rotation between the switching nut and the housing is prevented, the screw shaft is rotated in the reverse direction to eliminate the force acting between the concave portion and the movable pin. Can be done. Therefore, according to the present invention, it is possible to suppress the driving force to be applied to the movable pin in order to switch from the state where the relative rotation between the switching nut and the housing is prevented to the state where the relative rotation is not prevented. Can be achieved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a steering position adjusting device according to an embodiment of the present invention.

FIG. 2 is an axial cross-sectional view of the switching mechanism of the embodiment.

FIG. 3 shows the switching mechanism of the present embodiment taken along a straight line III-III shown in FIG.
It is sectional drawing at the time of cutting by.

FIG. 4 is a view showing a state in which a switching nut is locked in FIG. 3;

FIG. 5 is a diagram illustrating a state where the steering position adjusting device according to the embodiment performs a tilt operation.

FIG. 6 is a diagram illustrating a state in which the steering position adjusting device according to the present embodiment performs a telescopic operation.

FIG. 7 is a configuration diagram of a steering position adjusting device according to a second embodiment of the present invention.

FIG. 8 is a cross-sectional view of the connecting portion between the screw shaft and the motor shaft according to the present embodiment, taken along a line VIII-VIII shown in FIG.

FIG. 9 is an axial cross-sectional view of the connection mechanism of the present embodiment.

FIG. 10 is a diagram illustrating a state in which the steering position adjusting device according to the present embodiment performs a tilt operation.

FIG. 11 is a diagram illustrating a state in which the steering position adjusting device according to the present embodiment performs a telescopic operation.

FIG. 12 is a configuration diagram of a second embodiment of the switching mechanism according to the present invention.

FIG. 13 is an enlarged sectional view of a movable pin and a bolt according to the present embodiment.

FIG. 14 is a plan view showing a state where a housing is removed from the switching mechanism of the present embodiment, as viewed from above in FIG.

FIG. 15 is a cross-sectional view when the movable pin and the switching nut of the present embodiment are cut along a plane including the axis of the movable pin.

FIG. 16 is a view showing a state in which the switching nut is locked in FIG.

FIG. 17 is a view showing a state in which the movable pin rides on the peak of the tooth portion of the switching nut in FIG.

FIG. 18 is a configuration diagram of a third embodiment of the switching mechanism according to the present invention.

19 is a view showing a state in which the switching nut is locked in FIG.

FIG. 20 shows a flange portion of the switching nut according to the present embodiment in FIG.
It is the figure seen from the middle right.

FIG. 21 is a configuration diagram of a fourth embodiment of the switching mechanism according to the present invention.

FIG. 22 is a view of a switching nut and a switching arm of the switching mechanism according to the present embodiment as viewed from an axial direction.

FIG. 23 is a view of the slider of the switching mechanism according to the present embodiment as viewed from the right in FIG. 22;

FIG. 24 is an axial sectional view of a fifth embodiment of the switching mechanism according to the present invention.

FIG. 25 illustrates a switching mechanism according to the present embodiment using a straight line XXV- shown in FIG.
It is sectional drawing at the time of cutting along XXV.

FIG. 26 is an axial sectional view of a sixth embodiment of the switching mechanism according to the present invention;

FIG. 27 illustrates a switching mechanism according to the present embodiment with an arrow XXVI shown in FIG. 26;
FIG. 4 is a diagram when viewed from an I direction.

FIG. 28 shows the switching mechanism of the present embodiment in a straight line XXVI shown in FIG.
It is sectional drawing cut | disconnected along II-XXVIII.

FIG. 29 is a cross-sectional view similar to FIG. 28 when an engagement surface between the plunger and the lock hole is formed in a tapered shape.

FIG. 30 is an axial sectional view of a seventh embodiment of the switching mechanism according to the present invention.

FIG. 31 shows the switching mechanism of the present embodiment with the arrow XXXI shown in FIG.
It is a diagram when viewed from the -XXXI direction.

FIG. 32 In this embodiment, the screw shaft is
FIG. 9 is a diagram illustrating a state in which rotation is stopped by a predetermined angle θ in a reverse direction after rotation is stopped.

FIG. 33 is a sectional view taken along a line XXXIII-XXXIII shown in FIG. 32;

[Explanation of symbols]

10, 60 Steering position adjusting device 12 Column tube 16 Tilt support 20, 100, 150, 200, 300, 350, 40
0 Switching mechanism 22 Upper tube 26 Motor 34, 64 Nut 38 Fox joint 36, 40, 66 Screw shaft 46, 166, 206, 308, 402 Switching nut 46d, 206a Teeth 48, 110 Movable pin 166b, 402b Lock hole 208 Switching Arm 208 Lock pin 308c Worm wheel 312 Worm gear 316 Switching motor

Claims (5)

[Claims] 1. A column tube fixed to a vehicle body, a tilt support slidably provided with respect to the column tube, and supported to be tiltable up and down with respect to the tilt support and rotating a steering wheel. An upper tube to be supported, the column tube, the tilt support, and a screw shaft supported by the upper tube, a nut screwed to the screw shaft, a motor for rotating the screw shaft, and the screw By transmitting an axial driving force generated by a shaft to either the tilt support or the column tube, a telescopic operation in which the column tube and the tilt support are relatively displaced, and the tilt support and the upper tube Is relatively displaced A switching mechanism that selectively implements a switching operation, the switching mechanism comprising: a housing; a switching nut screwed onto the screw shaft; and the switching nut, with respect to the housing. Support means for supporting relative rotation about the axis while preventing relative displacement in the axial direction, and rotation preventing means for preventing relative rotation of the switching nut about the axis with respect to the housing. Steering position adjustment device. 2. The steering position adjusting device according to claim 1, wherein the rotation preventing means includes a recess provided in one of the switching nut or the housing and a pin provided in the other of the switching nut or the housing. Means for urging the pin toward the recess when rotation of the screw shaft is started. 3. The steering position adjusting device according to claim 1, wherein a bending means for bending the screw shaft is provided between a support portion of the screw shaft by the column tube and a support portion by the tilt support. A steering position adjusting device, wherein the screw shaft is swingably supported by the tilt support. 4. The steering position adjusting device according to claim 1, wherein the rotation preventing means is a worm wheel provided to rotate integrally with the switching nut; a worm gear meshing with the worm wheel; and the worm gear. And a driving means for rotating the steering wheel. 5. The steering position adjusting device according to claim 1, wherein the rotation preventing means includes a movable pin provided on one of the switching nut or the housing, and a movable pin provided on the other of the switching nut or the housing. And a recess provided so as to allow relative rotation between the switching nut and the housing only within a predetermined angle range when the switching nut and the housing are inserted. After the rotation of the screw shaft is stopped in a state where the relative rotation of the screw shaft is stopped, reverse rotation means for rotating the screw shaft by a predetermined angle in a direction opposite to the previous rotation direction is provided. Steering position adjustment device.