JP5082913B2 - Electric tilt type steering device - Google Patents

Description

  The present invention includes a steering column that rotatably supports a steering shaft to which a steering wheel is attached, a tilt bracket that supports the steering column so that the steering column can be tilted, and an electric tilt mechanism that tilts the steering column. The present invention relates to an electric tilt type steering apparatus.

2. Description of the Related Art Conventionally, an electric tilt type steering device connects one end side of a steering column to a vehicle body side member via a tilt pivot, and converts the rotational driving force of an electric motor into linear motion on the other end side of the steering column. An electric tilt mechanism for tilting the column is provided (see, for example, Patent Document 1).
FIG. 13 shows a conventional electric tilt mechanism. A steering shaft denoted by reference numeral 1 has a steering wheel (not shown) attached to the rear end of the vehicle, and the steering shaft 1 is rotatably supported. The rear end of the steering column 2 is held by an electric tilt mechanism 5 disposed on a tilt bracket 4 attached to the vehicle body side member 3 so as to be movable in the vertical direction.

The tilt bracket 4 is formed in a square frame shape when viewed from the vehicle front-rear direction and includes a mounting plate portion 4a, a pair of side plate portions 4b and 4c, and a bottom plate portion 4d. The mounting plate portion 4a is attached to the vehicle body side member 3. It has been.
The electric tilt mechanism 5 includes an upper rolling bearing 5a fixedly arranged on the mounting plate portion 4a of the tilt bracket 4, a lower rolling bearing 5b fixedly arranged on the lower portion of one side plate portion 4c of the tilt bracket 4, and the upper and lower rolling members. A screw shaft 5c rotatably supported by the bearings 5a and 5b, a worm 5e meshed with a worm wheel 5d coaxially mounted on the screw shaft 5c, and an output shaft coaxially connected to the worm 5e. An electric motor (not shown), a nut 5f screwed to the screw shaft 5c, a nut holder 5g holding the nut 5f, and protruding from the nut holder 5g to the engaging portion 2a of the steering column 2 The engaging pin 5h is engaged.

When the electric motor is driven forward, for example, the screw shaft 5c rotates in the reverse direction via the worm 5e and the worm wheel 5d, the nut 5f moves upward, and the steering column 2 moves upward about the tilt pivot shaft. Tilt operation. Further, when the electric motor is driven in reverse, for example, when the worm 5e is driven in reverse, the screw shaft 5c rotates in the forward direction, the nut 5f moves downward, and the steering column 2 tilts downward about the tilt pivot shaft. It is like that.
Japanese Patent Laid-Open No. 2002-2503 (first page, FIGS. 1 and 4)

By the way, the lower part of the mounting plate part 4a and the one side plate part 4c of the tilt bracket 4 in FIG. 13 receives an axial load (axial load) input to the screw shaft 5c via the upper rolling bearing 5a and the lower rolling bearing 5b. ing.
That is, when the steering column 2 is tilted upward, the nut 5f moves upward, whereby a downward axial reaction force (force indicated by the arrow D in FIG. 13) is input to the screw shaft 5c. The lower part of the one side plate portion 4c where the bearing 5b is disposed applies an upward bracket reaction force (the force indicated by the white arrow H in FIG. 13) to the screw shaft 5c, thereby causing the screw shaft 5c. Support. In addition, when a downward load acting on the steering wheel is transmitted to the electric tilt mechanism 5 via the steering column 2, the lower portion of the one side plate portion 4c causes the bracket reaction against the axial reaction force D input to the screw shaft 5c. Force H acts.

By the way, since the mounting plate portion 4a of the rectangular frame-shaped tilt bracket 4 described above is fixed in a state of being in surface contact with the vehicle body side member 3, the support stiffness in the vertical direction with respect to the upper rolling bearing 5a is high. The lower portion of the portion 4c has a lower support rigidity in the vertical direction with respect to the lower rolling bearing 5b.
Here, when the lightweight and small tilt bracket 4 having a reduced wall thickness is used to reduce the weight of the electric tilt type steering device, the downward load applied to the steering wheel or when the steering column 2 tilts upward. Is transmitted to the electric tilt mechanism 5 via the steering column 2, the lower part of the one side plate portion 4c and the bottom plate portion 4d do not act on the axial reaction force D with the bracket reaction force H equivalent to the axial reaction force D, The lower part of one side plate part 4c and the bottom plate part 4d are bent downward, and the support rigidity of the steering column 2 may be lowered.

  Further, when the lower portion of one side plate portion 4c and the bottom plate portion 4d are bent downward during the tilting operation of the steering column 2 and the lower rolling bearing 5b and the screw shaft 5c are displaced downward, the upper rolling bearing 5a, A backlash (gap) is generated between the screw shaft 5c inserted through the inner ring of the rolling bearing 5a. When the screw shaft 5c is displaced upward so that there is no backlash between the upper rolling bearing 5a and the tilting operation of the steering column 2 below, abnormal noise is generated by the metal contact between the inner ring of the upper rolling bearing 5a and the screw shaft 5c. May occur.

  Therefore, the present invention has been made by paying attention to the unsolved problems of the above-described conventional example, and even when the rigidity of the tilt bracket is reduced for weight reduction, the support rigidity of the steering column can be ensured. In addition, an object of the present invention is to provide an electric tilt type steering apparatus that can suppress the generation of abnormal noise due to the metal contact between the screw shaft and the bearing.

  In order to achieve the above object, the invention according to claim 1 is directed to a steering column rotatably supported by a steering shaft to which a steering wheel is attached, and fixed to a vehicle body side member. A tilt bracket that holds the steering column so as to be tiltable, and an electric actuator that tilts the steering column, and the electric actuator extends through the bearing so as to extend in the vertical direction. A screw shaft rotatably supported by the bracket, a nut screwed to the screw shaft, a vertical movement transmitting means for transmitting the vertical movement of the nut to the steering column, and a forward / reverse drive of the electric motor A rotation transmission mechanism that transmits the rotation to the screw shaft as rotation in the forward rotation direction and the reverse rotation direction. In the electric tilt type steering apparatus, the bearing includes an upper bearing that supports an upper end shaft portion of the screw shaft, and a lower bearing that supports a lower end shaft portion of the screw shaft, and the upper bearing includes the screw The upper end shaft portion is rotatably supported while receiving an axial load acting on the shaft, and the lower bearing is configured to rotatably support the lower end shaft portion without receiving the axial load.

  Further, the invention according to claim 2 is the electric tilt type steering apparatus according to claim 1, wherein the upper bearing is constituted by a radial ball bearing having an inner ring and an outer ring whose axial core extends in the vertical direction, The inner ring of the upper bearing is inserted into the upper end shaft portion with the relative movement in the axial direction being restricted by the inner ring fixing means, and the outer ring of the upper bearing is close to the vehicle body side member of the tilt bracket by the outer ring fixing means. The relative movement in the axial direction with respect to the part was restricted and arranged.

According to a third aspect of the present invention, in the electric tilt type steering apparatus according to the second aspect, the inner ring fixing means includes a spacer fixed to a base portion of the upper end shaft portion and abutting against a lower surface of the inner ring, and the upper end It is a detachable engagement member that is mounted in an annular groove formed on the outer periphery on the tip side of the shaft portion and abuts against the upper surface of the inner ring.
According to a fourth aspect of the present invention, in the electric tilt type steering apparatus according to the third aspect, the engagement member is a C-ring.

According to a fifth aspect of the present invention, in the electric tilt type steering apparatus according to the second aspect, the inner ring fixing means is located at a base portion of the upper end shaft portion and the threaded portion of the screw shaft that is locked by the inner ring. And a male screw portion formed on the tip end side of the upper end shaft portion, and a fixing nut that is screwed into the male screw portion and comes into contact with the upper surface of the inner ring.
According to a sixth aspect of the present invention, in the electric tilt type steering apparatus according to the second aspect, the inner ring fixing means is configured such that the upper end shaft portion is press-fitted into the inner ring of the upper bearing.

According to a seventh aspect of the present invention, in the electric tilt type steering apparatus according to any one of the second to sixth aspects, the outer ring fixing means is formed in a portion of the tilt bracket adjacent to the vehicle body side member. And a detachable engaging member that is attached to the annular groove in a recess that is in contact with the upper surface of the outer ring and an annular groove that is formed at the periphery of the opening of the recess, and that contacts the lower surface of the outer ring.
According to an eighth aspect of the present invention, in the electric tilt type steering apparatus according to the seventh aspect, the engagement member is a C-ring.

According to a ninth aspect of the present invention, in the electric tilt type steering apparatus according to the fourth or eighth aspect, the C-ring regulates the axial movement of the upper bearing with respect to the upper end shaft portion. This is a member with a tapered cross section whose thickness gradually increases from the outer diameter side toward the outer diameter side.
According to a tenth aspect of the present invention, in the electric tilt type steering apparatus according to any one of the second to seventh aspects, the outer ring fixing means is formed in a portion of the tilt bracket adjacent to the vehicle body side member. And a recess into which the outer ring is press-fitted.

According to an eleventh aspect of the present invention, in the electric tilt type steering apparatus according to any one of the second to seventh aspects, the outer ring fixing means is formed in a portion of the tilt bracket adjacent to the vehicle body side member. A recessed portion in which the lower surface of the outer ring contacts, and a fixing member fixed in the recessed portion and in contact with the upper surface of the outer ring.
Further, the invention according to claim 12 is the electric tilt type steering apparatus according to any one of claims 2 to 6, wherein the outer ring fixing means is formed in a portion of the tilt bracket adjacent to the vehicle body side member. A recess that is in contact with the upper surface of the outer ring, and a crimped portion that is formed to have a reduced diameter by caulking the opening periphery of the recess and is in contact with the lower surface of the outer ring.

  According to the electric tilt type steering apparatus according to the present invention, the upper bearing receives an axial load that is input to the screw shaft during the tilt-up / tilt-down adjustment of the steering column, but the lower bearing does not receive the axial load. Therefore, in order to reduce the weight of the electric tilt type steering device, the upper bearing is fixedly arranged and supported on the vehicle body side member side even if the tilt bracket is formed to be light and small with a reduced thickness. The upper part of the highly rigid tilt bracket reliably receives the axial load input to the screw shaft during tilt up / down adjustment of the steering column. On the other hand, the support rigidity is low due to the reduced thickness, and the lower portion of the tilt bracket where the lower bearing is fixed is not subjected to an axial load. For this reason, the lower part of the tilt bracket does not bend downward during the tilt-up / tilt-down adjustment, so that the support rigidity of the steering column can be ensured.

  In addition, when the steering column is tilted up, the lower part of the tilt bracket does not bend downward. As a result, the screw shaft is not displaced in the axial direction with respect to the upper bearing, and the joint between the upper bearing and the screw shaft does not play. Since there is no site where the occurrence of the noise, it is possible to suppress the generation of noise due to the metal contact between the upper bearing and the screw shaft.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an overall configuration diagram showing a vehicle assembled with a steering device according to the present invention, FIG. 2 is a left side view showing a first embodiment of the steering device according to the present invention, and FIG. 3 is an arrow line AA in FIG. FIG. 4 is a cross-sectional view of the main part showing the upper rolling bearing supporting the upper part of the screw shaft of the first embodiment, and FIG. 5 is the lower rolling bearing supporting the lower part of the screw shaft of the first embodiment. 6 is a sectional view taken along the line B-B in FIG. 3, FIG. 7 is a sectional view showing the electric telescopic mechanism, FIG. 8 is a sectional view taken along the line C-C in FIG. 7, and FIG. The figure which shows the principal part of the electric tilt mechanism of 2nd Embodiment which concerns on this invention, FIG. 10 is the figure which shows the principal part of the electric tilt mechanism of 3rd Embodiment which concerns on this invention, FIG. 11: 4th Embodiment which concerns on this invention The figure which shows the principal part of the electric tilt mechanism of a form, FIG. 12 is a figure which shows the principal part of the electric tilt mechanism of 5th Embodiment based on this invention.

  In FIG. 1, a steering column device 10 includes a steering column 12 that supports a steering shaft 11 so as to be rotatable. A steering wheel 13 is mounted at the rear end of the steering shaft 11, and an intermediate shaft 15 is connected to the front end of the steering shaft 11 via a universal joint 14. A steering gear 17 composed of a rack and pinion mechanism or the like is connected to the intermediate shaft 15 through a universal joint 16 at the front end thereof. The output shaft of the steering gear 17 is connected to the steering wheel 19 via a tie rod 18.

When the driver steers the steering wheel 13, the rotational force is transmitted to the steering gear 17 via the steering shaft 11, the universal joint 14, the intermediate shaft 15, and the universal joint 16, and the rack and pinion mechanism rotates the vehicle. The steering wheel 19 is steered through the tie rod 18 after being converted into a linear motion in the width direction.
In addition, peripheral parts P such as a control switch, a combination switch, a column cover, and the like for driving an electric tilt mechanism 30 and an electric telescopic mechanism 50 described later are disposed at a rear portion of the steering column 12 in the vehicle.

(First embodiment)
As shown in FIG. 2, the steering column device 10 includes a steering shaft 11 to which a steering wheel 13 (not shown in FIG. 2) is attached, and a steering column 12 that rotatably supports the steering shaft.

The steering column 12 includes an outer column 12a and an inner column 12b that is slidably held by the outer column 12a, and is a rolling bearing disposed on the inner peripheral surface of the side end portion of the inner column 12b on the handle side. The steering shaft 11 is supported by a rolling bearing (not shown) disposed in the gear housing 71 and a gear housing 71.
The outer column 12a is mounted with an electric power steering device 70, which will be described later, on the vehicle front end side (left end in FIG. 2) on the universal joint 14 side, and in an insertion hole 71a formed in the gear housing 71 of the electric power steering device 70. As shown in FIG. 2, the tilt pivot shaft 72 inserted through is fixed to a vehicle body side bracket 73 attached to the vehicle body side member 21.

Further, the rear end (right end in FIG. 2) of the outer column 12a on the steering wheel 13 side is attached to the vehicle body side member 21 and supported by the tilt bracket 24 so as to be movable in the vertical direction.
As shown in FIG. 3, the tilt bracket 24 includes a mounting plate portion 24b having a bulging portion 24a with a central portion bulging upward as viewed from the front, and the mounting plate portion 24b. The guide plate portions 24c and 24d for guiding the steering column 12 extending downward from the left and right positions of the bulge portion 24a and the bottom plate portion 24e connecting the lower end portions of the guide plate portions 24c and 24d form a rectangular frame shape. Is formed.

  Further, the steering column 12 is held so as to be movable in the vertical direction by an electric tilt mechanism 30 disposed on the vehicle front side (left side in FIG. 2) of the guide plate portions 24c and 24d of the tilt bracket 24.

  As shown in FIG. 3, the electric tilt mechanism 30 includes a radial ball bearing fixedly disposed in a substantially rectangular frame-shaped gear housing 31 formed integrally with the lower end portion of the guide plate portion 24 c of the tilt bracket 24. The lower rolling bearing 33, the upper rolling bearing 34 composed of a radial ball bearing fixedly disposed below the mounting plate portion 24b of the tilt bracket 24, and the guide plate portion 24c extend in the vertical direction and extend in the axial direction. Both end portions are provided with a lower rolling bearing 33 and a screw shaft 35 rotatably supported by the upper rolling bearing 34.

  The upper and lower ends of the screw shaft 35 are formed with a cylindrical upper bearing engaging portion 35a and a lower bearing engaging portion 35b having a diameter smaller than the outer diameter of the screw, and at positions adjacent to the lower bearing engaging portion 35b. A large-diameter portion 35c for mounting a worm wheel 36, which will be described later, is formed.

  As shown in FIG. 4, a cylindrical spacer 80 in which an annular notch is formed on the outer periphery of the upper portion is fitted on the upper bearing engaging portion 35 a of the screw shaft 35. Then, the upper bearing engaging portion 35a is inserted into the inner ring 34a of the upper rolling bearing 34, and the first C ring 81 is attached to the annular groove formed in the upper portion of the upper bearing engaging portion 35a, whereby the inner ring 34a with respect to the screw shaft 35 is mounted. The movement in the axial direction is restricted.

  A through hole 24b1 is formed in the mounting plate portion 24b, and an annular step surface 24b2 facing downward is formed on the inner peripheral surface of the through hole 24b1. An annular recess 82 is formed in the lower portion of the through hole 24b1 in a direction orthogonal to the axis of the screw shaft 35. And the upper rolling bearing 34 is arrange | positioned from the downward direction of the through-hole 24b1 so that the outer ring | wheel 34b may contact | abut on the level | step difference surface 24b2. In addition, by mounting the second C ring 83 between the annular recess 82 and the annular notch of the spacer 80 facing the annular recess 82, the vertical movement of the outer ring 34b relative to the mounting plate portion 24b is restricted, An upper rolling bearing 34 is fixedly disposed below the mounting plate portion 24b.

Thus, the upper end of the screw shaft 35 is rotatably supported by the upper rolling bearing 34 while the relative movement in the axial direction is restricted.
The lower rolling bearing 33 is also a radial ball bearing, and is fixedly arranged by a screw cover 32 screwed into the gear housing 31 from below as shown in FIG.

  The lower bearing engaging portion 35b of the screw shaft 35 is inserted into the inner ring 33a while providing a predetermined gap δ between the aforementioned large diameter portion 35c and the upper end surface of the inner ring 33a of the lower rolling bearing 33. Thus, the lower end of the screw shaft 35 is rotatably supported by the lower rolling bearing 33 while being relatively movable in the axial direction.

  As shown in FIG. 3, a worm wheel 36 is attached to the large diameter portion 35 c of the screw shaft 35, and a worm 37 is engaged with the worm wheel 36. As shown in FIG. 6, the worm 37 is rotatably held by rolling bearings 38 and 39 disposed in the gear housing 31, and one end of the worm 37 is formed on the guide plate portion 24c of the tilt bracket 24. The output shaft 40a of the electric motor 40 fixed to the plate portion 24h is connected via a coupling 40b.

On the other hand, a ring-shaped damper 84 made of a synthetic resin such as polyurethane having elasticity locked to the screw end portion of the screw shaft 35 is disposed below the spacer 80 described above.
A cylindrical cover 41 that covers the screw shaft 35 is disposed in an insertion hole 31 a through which the screw shaft 35 of the gear housing 31 is inserted, and a large elasticity that slides on the outer peripheral surface of the screw shaft 35 at the tip of the cylindrical cover 41. A damper 42 formed of a synthetic resin such as polyurethane having

  A nut 45 held by a nut holder 44 having a square cross section is screwed between the dampers 42 and 84 of the screw shaft 35. Further, an engagement pin 47a formed to project from the nut holder 44 toward the outer column 12a engages with an elongated hole 12e formed in the outer column 12a and extending in the axial direction, and the nut holder 44 extends from the outer column 12a. An engaging pin 47b that protrudes in a direction away from the engaging member engages with a guide hole 49a of a guide member 49 (see FIG. 2) integrated with the outer periphery of the outer column 12a. The screw shaft 35 is moved in the vertical direction by the forward and reverse rotation of the screw shaft 35 while the rotational motion around the axis of the screw shaft 35 is restricted. As shown in FIG. 3, a bulging portion 12d having a flat guide surface 12c that is close to and faces the guide plate portion 24d is formed on the outer periphery of the outer column 12a.

According to the electric tilt mechanism 30 having the above configuration, when the worm 37 is driven forward and backward by the electric motor 40, the screw shaft 35 is driven forward and backward via the worm wheel 36, whereby the nut holder 44 is moved up and down, and the outer The column 12a can be swung up and down about the tilt pivot shaft 72 to exert a tilt function.
Further, as shown in FIG. 2, an electric telescopic mechanism 50 as an electric actuator is provided between the outer column 12a and the inner column 12b of the steering column 12.

  As shown in FIG. 7, the electric telescopic mechanism 50 includes a gear housing 51 fixed to the steering wheel 13 side of the outer column 12 a of the steering column 12. A worm wheel 53 is rotatably supported on the gear housing 51 by ball bearings 52a and 52b arranged to face each other at a predetermined distance in the axial direction of the steering column 12.

  As shown in FIGS. 7 and 8, the worm wheel 53 is engaged with a worm 56 connected to an output shaft of an electric motor 55 attached to the gear housing 51. Here, the worm 56 is rotatably supported by rolling bearings 56a and 56b disposed in the gear housing 51, and is connected to the output shaft 55a of the electric motor 55 via a coupling 55b.

Further, a connecting plate 57 extending in the same direction as the gear housing 51 in the circumferential direction is attached in the vicinity of the steering wheel 13 side end portion of the inner column 12 b of the steering column 12, and the connecting plate 57 is connected between the connecting plate 57 and the gear housing 51. A rod 58 is provided.
The connecting rod 58 includes an outer rod 58a having one end rigidly fixed to the lower end of the connecting plate 57, and an inner rod 58b slidably engaged with the other end of the outer rod 58a.

  In the engaging portion between the outer rod 58a and the inner rod 58b, the relative movement between the outer rod 58a and the inner rod 58b is restricted by a human force at a normal time, but an impact load is applied to the steering wheel 13, the inner rod 58 during a secondary collision. A connection holding member 60 that allows relative movement between the outer rod 58a and the inner rod 58b when being transmitted to the outer rod 58a via the column 12b and the connection plate 57 is disposed.

The connection holding member 60 has a structure in which a thin leaf spring material formed in a ring shape in which the cross section is uneven in the circumferential direction is formed in a ring shape, and a collapse load that allows relative movement of the outer rod 58a and the inner rod 58b is, for example, It is set to about 2 kN or more.
The inner rod 58b is formed with a male screw 58c on the opposite side of the outer rod 58a. The male screw 58c is screwed into a female screw 53a of a worm wheel 53 rotatably supported by the gear housing 51, thereby connecting rod 58. Is arranged so as to be parallel to the steering column 12 at a position separated by a distance L.

  According to the electric telescopic mechanism 50 having the above configuration, the worm wheel 53 can be driven forward and backward via the worm 56 by driving the electric motor 55 forward and backward, and the inner rod 58b is moved back and forth in the axial direction of the steering column 12. By advancing, the inner column 12b is expanded and contracted in the axial direction via the outer rod 58a and the connecting plate 57, thereby exhibiting a telescopic function.

  Further, as shown in FIG. 2, the electric power steering device 70 includes a gear housing 71 including a worm reduction gear integrally connected to the vehicle front side end portion of the outer column 12 a, and the gear housing 71. The electric motor 75 and a control unit 76 having a drive control unit for driving and controlling the electric motor 75 are provided. The gear housing 71 is formed with the insertion hole 71a through which the tilt pivot shaft 72 is inserted, as described above.

  Here, the vertical movement transmission means of the present invention corresponds to the engagement pin 47a and the long hole 12e, the rotation transmission mechanism of the present invention corresponds to the worm wheel 36 and the worm 37, and the upper bearing of the present invention is the upper rolling bearing 34. The lower bearing of the present invention corresponds to the lower rolling bearing 33, the concave portion of the present invention corresponds to the through hole 24b1, the upper end shaft portion of the present invention corresponds to the upper bearing engaging portion 35a, and the lower end of the present invention. The shaft portion corresponds to the lower bearing engaging portion 35b.

Next, the operation of the above embodiment will be described.
Now, in order for the driver to adjust the tilt of the steering column 12 of the steering column device 10, the control for the tilt mechanism provided in the peripheral part P provided in the rear part of the steering column 12 shown in FIG. When the switch is operated in the tilt-up direction (or tilt-down direction), the electric motor 40 of the electric tilt mechanism 30 is driven forward (or reverse), for example.

  In response to this, when the screw shaft 35 is driven in reverse (or forward) via the worm 37 and the worm wheel 36, the nut 45 moves in the lateral direction while moving upward (or downward). The engaging pin 47a protruding from the nut holder 44 engages with the elongated hole 12e of the outer column 12a, and the engaging pin 47b protruding from the nut holder 44 is integrated with the outer periphery of the outer column 12a. Since the outer column 12a is rotated upward (downward) about the tilt pivot shaft 72, tilt up (or tilt down) adjustment is performed.

  In addition, in order for the driver to perform telescopic adjustment of the steering column 12 of the steering column device 10, a control for a telescopic mechanism provided in a peripheral part P disposed in the vehicle rear portion of the steering column 12 shown in FIG. When the switch is operated in the expansion direction (or contraction direction), the electric motor 55 of the electric telescopic mechanism 50 is driven forward (or reverse), for example.

  As a result, the worm wheel 53 is driven to rotate forward (or reversely) via the worm 56, whereby the connecting rod 58 moves to the steering wheel 13 side (or the side opposite to the steering wheel 13). For this reason, the inner column 12b is pulled out from the outer column 12a via the connecting plate 57 (or the inner column 12b is inserted into the outer column 12a), and the steering column 12 is expanded (or contracted) to perform telescopic adjustment. Is called.

  At this time, along with the movement of the inner column 12b, the outer shaft 11a of the steering shaft 11 moves relative to the inner shaft 11b. As described above, when the connecting rod 58 is moved by the electric motor 55 by the electric telescopic mechanism 50, the outer rod 58 a and the inner rod 58 b of the connecting rod 58 are connected and held by the connecting holding member 60, whereby the steering column 12. In FIG. 7, when an impact load in the horizontal direction of the vehicle acts on the steering wheel 13 due to a secondary collision, the inner column 12b and the inner shaft 11b are moved by the impact load. Pushing to the left in the column axial direction, the outer rod 58a of the connecting rod 58 is moved to the left via the connecting plate 57 in response to this, whereby an impact load is transmitted to the connecting and holding member 60. When the impact load transmitted to the connecting and holding member 60 reaches a set collapse load, the holding state of the outer rod 58a and the inner rod 58b by the connecting and holding member 60 is released, and the inner rod 58b is inserted into the outer rod 58a. As a result, a predetermined collapse stroke can be secured.

  On the other hand, in the electric power steering device 70, the drive control unit in the control unit 76 calculates a steering assist command value based on a steering torque detected by a steering torque sensor (not shown), and the electric power steering device 70 is electrically operated based on the calculated steering assist command value. By driving and controlling the motor 75, the electric motor 75 generates a steering assist force, and this steering assist force is transmitted to the inner shaft 11b of the steering shaft 11 via the worm speed reducer. Can be steered with a light steering force.

Thus, when the electric power steering device 70 generates a steering assist force for the steering shaft 11, a reaction force against the steering assist force is transmitted to the outer column 12 a via the gear housing 71.
For this reason, the outer column 12a rotates, but in the vehicle body side bracket 73, the outer column 12a is displaced by its elastic deformation to allow the rotation.

Next, the effect of this embodiment is demonstrated.
When the nut 45 moves upward along with the rotation of the screw shaft 35 by adjusting the tilt-up of the outer column 12a, a downward axial reaction force (force indicated by an arrow D in FIG. 3) is input to the screw shaft 35.
At this time, the upper rolling bearing 34 is fixedly arranged at the lower portion of the mounting plate portion 24b while restricting the relative movement in the axial direction with respect to the upper end (upper bearing engaging portion 35a) of the screw shaft 35. An upward bracket reaction force (force indicated by a white arrow H in FIG. 3) is applied to the screw shaft 35. On the other hand, in the lower rolling bearing 33, the lower bearing engaging portion 35b is inserted into the inner ring 33a in a state where a predetermined gap δ is provided between the large diameter portion 35c and the upper surface of the inner ring 33a. Since the lower end (lower bearing engaging portion 35b) of 35 is supported so as to be relatively movable in the axial direction with respect to the lower rolling bearing 33, the axial reaction force D of the screw shaft 35 is not received.

Further, when an upward axial reaction force (not shown) is input to the screw shaft 35 by the tilt-down adjustment of the outer column 12a, the upper rolling bearing 34 has a downward bracket reaction force (with respect to the upward axial reaction force ( The screw shaft 35 is received by acting (not shown). Further, the lower rolling bearing 33 does not receive the upward axial reaction force input to the screw shaft 35.
As described above, the upper rolling bearing 34 of the present embodiment receives an axial load (downward axial reaction force D, upward axial reaction force) input to the screw shaft 35 during tilt-up / tilt-down adjustment of the outer column 12a. However, the lower rolling bearing 33 has a structure that does not receive the axial load.

  Therefore, in order to reduce the weight of the steering column device 10, the gear housing 31 and the tilt bracket 24 are fixed and supported while being in surface contact with the vehicle body side member 21 even if the gear housing 31 and the tilt bracket 24 are formed to be light and small in thickness. The mounting plate portion 24b side of the tilt bracket 24 having high rigidity reliably receives the axial load input to the screw shaft 35 during the tilt-up / tilt-down adjustment of the outer column 12a, and has a structure with low support rigidity due to a reduction in the thickness. Since the gear housing 31 in which the lower rolling bearing 33 is fixed is not subjected to an axial load, the gear housing 31 and the bottom plate portion 24e are not bent downward during tilt-up / tilt-down adjustment, and the outer column 12a is supported. Rigidity can be ensured.

  Further, the gear housing 31 and the lower rolling bearing 33 do not bend downward during the tilt-up adjustment of the outer column 12a, and the screw shaft 35 is not displaced in the axial direction with respect to the upper rolling bearing 34. Since there is no portion where play occurs at the connecting portion with the shaft 35, it is possible to suppress the generation of noise due to the metal contact between the upper rolling bearing 34 and the screw shaft 35.

(Second Embodiment)
Next, what is shown in FIG. 9 shows a second embodiment of the electric tilt mechanism 30 according to the present invention. In addition, the same code | symbol is attached | subjected to the same component as FIGS. 3-5 which showed 1st Embodiment, and the description is abbreviate | omitted.

The upper bearing engaging portion 35a of the screw shaft 35 of the present embodiment includes a shaft portion 35a1 inserted into the inner ring 34a and a male screw portion 35a2 formed from the shaft portion 35a1 to the tip.
A through hole 85 is also formed in the mounting plate portion 24 b of the present embodiment, and an annular step surface 86 facing upward is formed at the lower part of the inner peripheral surface of the through hole 85. The inner peripheral surface of the hole 85 is formed as a female screw portion 87.

  In the upper rolling bearing 34, the inner ring 34a into which the shaft portion 35a1 is inserted is brought into contact with the base portion of the upper bearing engaging portion 35a, the fixing nut 88 is screwed into the male screw portion 35a2, and the lower surface of the outer ring 34b is brought into contact with the step surface 86. After the contact, the screw cover 89 is screwed into the female thread portion 87 from above, so that the inner ring 34a is restricted from moving in the vertical direction by the base portion of the upper bearing engaging portion 35a and the fixing nut 88, and the outer ring 34b is The screw cover 89 restricts vertical movement. Thus, the upper end of the screw shaft 35 is rotatably supported by the upper rolling bearing 34 while the relative movement in the axial direction is restricted.

The concave portion of the present invention corresponds to the through hole 85.
Accordingly, in the present embodiment, similarly to the first embodiment, the upper rolling bearing 34 is disposed below the mounting plate portion 24b while restricting the relative movement in the axial direction with respect to the upper end (upper bearing engaging portion 35a) of the screw shaft 35. Since the lower rolling bearing 33 is fixedly disposed and supports the lower end (lower bearing engaging portion 35b) of the screw shaft 35 so as to be relatively movable in the axial direction, the gear housing 31 and the tilt bracket 24 are thickened. Even when the weight is reduced and the size is reduced, the gear housing 31 and the bottom plate portion 24e do not bend downward during tilt-up / tilt-down adjustment, and the support rigidity of the outer column 12a can be ensured. In addition, since no play occurs at the connecting portion between the upper rolling bearing 34 and the screw shaft 35, it is possible to suppress the generation of noise due to the metal contact between the upper rolling bearing 34 and the screw shaft 35.

(Third embodiment)
Next, FIG. 10 shows a third embodiment of the electric tilt mechanism 30 according to the present invention.
The mounting plate portion 24b of the present embodiment is formed with a fitting recess 90 that opens downward in a circular shape.
In the upper rolling bearing 34, the upper bearing engaging portion 35a is press-fitted into the inner ring 34a, and the outer ring 34b is press-fitted into the fitting recess 90. Thus, the upper end of the screw shaft 35 is rotatably supported by the upper rolling bearing 34 while the relative movement in the axial direction is restricted.

The concave portion of the present invention corresponds to the fitting concave portion 90.
Accordingly, in the present embodiment, similarly to the first embodiment, the upper rolling bearing 34 is disposed below the mounting plate portion 24b while restricting the relative movement in the axial direction with respect to the upper end (upper bearing engaging portion 35a) of the screw shaft 35. Since the lower rolling bearing 33 is fixedly disposed and supports the lower end (lower bearing engaging portion 35b) of the screw shaft 35 so as to be relatively movable in the axial direction, the gear housing 31 and the tilt bracket 24 are thickened. Even when the weight is reduced and the size is reduced, the gear housing 31 and the bottom plate portion 24e do not bend downward during tilt-up / tilt-down adjustment, and the support rigidity of the outer column 12a can be ensured. In addition, since no play occurs at the connecting portion between the upper rolling bearing 34 and the screw shaft 35, it is possible to suppress the generation of noise due to the metal contact between the upper rolling bearing 34 and the screw shaft 35.

(Fourth embodiment)
Next, what is shown in FIG. 11 shows a fourth embodiment of the electric tilt mechanism 30 according to the present invention.
In the present embodiment, the third C ring 92 is attached to the annular groove 91 formed in the upper bearing engaging portion 35 a of the screw shaft 35. The third C ring 92 is a member having a single-sided tapered cross section in which the ring thickness is gradually increased from the inner diameter side toward the outer diameter side.
In this embodiment, an O-ring 93 is mounted at a position where a gap δ is provided between the large-diameter portion 35 c and the upper end surface of the inner ring 33 a of the lower rolling bearing 33.

  Therefore, according to the present embodiment, even if there is a slight dimensional error between the annular groove 91 and the upper surface of the spacer 80, the diameter of the third C ring 92 that enters the annular groove 91 changes to change the inner ring of the upper rolling bearing 34. The axial thickness of the upper rolling bearing 35 with respect to the upper bearing engaging portion 35a can be restricted while absorbing the error by appropriately changing the thickness of the ring abutting on 34a, so that the upper rolling bearing 34 with respect to the screw shaft 35 can be restricted. The fixing structure may not be formed with high accuracy.

  In addition, since the O-ring 93 is mounted at a position where a gap δ is provided between the large diameter portion 35c and the upper end surface of the inner ring 33a of the lower rolling bearing 33, the difference between the large diameter portion 35c and the inner ring 33a due to metal contact. Sound generation can be prevented.

(Fifth embodiment)
Further, FIG. 12 shows a fifth embodiment of the electric tilt mechanism 30 according to the present invention.
In the present embodiment, for example, the spacer 80 and the second C ring 83 arranged in the lower portion of the upper rolling bearing 34 in the fourth embodiment of FIG. 11 are not used, and the inner ring 34a of the upper rolling bearing 34 is the upper bearing engaging portion 35a. It is in contact with the base. Further, the crimping portion 94 is formed by reducing the diameter by caulking (plastically deforming) the periphery of the lower opening of the through hole 24b1. Thereby, the axial movement of the outer ring 34 b of the upper rolling bearing 34 is restricted by the step surface 24 b 2 and the caulking portion 94.

Therefore, in the present embodiment, the upper rolling bearing 34 can be fixed to the mounting plate portion 24b without using the spacer 80 or the second C ring 83, so that the manufacturing cost can be reduced by reducing the number of parts. it can.
In each of the above embodiments, the lower rolling bearing 33 of the electric tilt mechanism 30 is a radial ball bearing. However, the lower rolling bearing 33 is connected to the screw shaft 35 when the steering column 12 is tilted up / down. Since the input axial load is not received, the lower rolling bearing may be constituted by a sliding bearing. Moreover, although the lower part of the lower rolling bearing 33 of each embodiment is supported by the screw cover 32, this screw cover 32 is not used, and the bottom rolling bearing 33 is formed in a bottomed hole formed in the lower part of the gear housing 31. You may make it arrange | position and support a lower part. Further, when an elastic member such as rubber is disposed between the inner ring of the lower rolling bearing 33 and the outer periphery of the lower bearing engaging portion 35b, the positioning of the lower rolling bearing 33 is made rough and the generation of abnormal noise is prevented. Can do.

Although the case where the outer column 12a of the steering column 12 is fixed to the vehicle body side member 21 has been described, the present invention is not limited to this, and the inner column 12b is attached to the vehicle body side member 21 by the vehicle body side bracket 73 and the tilt bracket 24. The steering wheel 13 may be attached to the outer column 12a.
Moreover, in each said embodiment, although the case where the connection holding member 60 was arrange | positioned to the connection rod 58 of the electric telescopic mechanism 50 was demonstrated, it is not limited to this, The connection holding member 60 of the connection rod 58 is used. The connecting rod 58 is omitted and is constituted by a single rod. Instead, the motor housing that supports the electric motor 55 is detached from the outer column 12a when an impact load greater than the collapse load is applied to the outer column 12a. You may make it connect via a connection holding member.

In each of the above embodiments, the steering column device 10 including the electric telescopic mechanism 50 and the electric power steering device has been described. However, the device may include only the electric tilt mechanism.
Further, in each of the above embodiments, the worm wheel 36 is attached to the large diameter portion 35c of the screw shaft 35. However, if a helical gear is used instead of the worm wheel 36, positioning relative to the large diameter portion 35c may be rough. it can.

1 is an overall configuration diagram showing a vehicle in which a steering device according to the present invention is assembled. 1 is a left side view showing a first embodiment of a steering device according to the present invention. It is an AA arrow directional view of FIG. It is principal part sectional drawing which shows the upper rolling bearing which is supporting the upper part of the screw shaft of 1st Embodiment. It is principal part sectional drawing which shows the lower rolling bearing which is supporting the lower part of the screw shaft of 1st Embodiment. It is a BB line arrow directional view of FIG. It is sectional drawing which shows an electric telescopic mechanism. It is CC line arrow line view of FIG. It is a figure which shows the principal part of the electric tilt mechanism of 2nd Embodiment which concerns on this invention. It is a figure which shows the principal part of the electric tilt mechanism of 3rd Embodiment which concerns on this invention. It is a figure which shows the principal part of the electric tilt mechanism of 4th Embodiment which concerns on this invention. It is a figure which shows the principal part of the electric tilt mechanism of 5th Embodiment which concerns on this invention. It is a figure which shows the electric tilt mechanism of the conventional steering apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Steering column apparatus, 11 ... Steering shaft, 11a ... Outer shaft, 11b ... Inner shaft, 12 ... Steering column, 12a ... Outer column, 12b ... Inner column, 12c ... Guide surface, 12d ... Swelling part, 12e ... Long Hole: 13 ... Steering wheel, 14 ... Universal joint, 15 ... Intermediate shaft, 16 ... Universal joint, 17 ... Steering gear, 18 ... Tie rod, 19 ... Steering wheel, 21 ... Body member, 24 ... Tilt bracket, 24a ... Swell Protruding part, 24b ... Mounting plate part, 24b1 ... Through hole, 24b2 ... Stepped surface, 24c ... Guide plate part, 24e ... Bottom plate part, 24h ... Mounting plate part, 30 ... Electric tilt mechanism, 31 ... Gear housing, 31a ... Insertion Hole, 32 ... Screw cover, 33 ... Lower rolling bearing, 33a ... Inside 34 ... Upper rolling bearing, 34a ... Inner ring, 34b ... Outer ring, 35 ... Screw shaft, 35a ... Partial bearing engagement part, 35a1 ... Shaft part, 35a2 ... Male thread part, 35b ... Lower bearing engagement part, 35c ... Large diameter 36, worm wheel, 37 ... worm, 38, 39 ... bearing, 40 ... electric motor, 40a ... output shaft, 40b ... coupling, 41 ... cylindrical cover, 42 ... damper, 44 ... nut holder, 45 ... nut , 47a ... engaging pin, 47b ... engaging pin, 49 ... guide member, 49a ... guide hole, 50 ... electric telescopic mechanism, 51 ... gear housing, 52a ... ball bearing, 53 ... worm wheel, 55 ... electric motor, 55a ... Output shaft, 55b ... Coupling, 56 ... Worm, 56a ... Bearing, 57 ... Connection plate, 58 ... Connection rod, 58a ... Outer rod, 58b ... Innero 59 ... Pivot pin, 60 ... Connection holding member, 70 ... Electric power steering device, 71 ... Gear housing, 71a ... Insertion hole, 72 ... Tilt pivot shaft, 73 ... Body-side bracket, 75 ... Electric motor, 76 ... Control Unit: 80 ... Spacer, 81 ... 1st C-ring, 82 ... Annular recess, 83 ... 2nd C-ring, 84 ... Damper, 85 ... Through-hole, 86 ... Stepped surface, 87 ... Female thread, 88 ... Fixing nut, 89 ... Screw Cover, 90 ... fitting recess, 91 ... annular groove, 92 ... 3rd C ring, 93 ... O-ring, 94 ... caulking part

Claims (12)

A steering column that rotatably supports a steering shaft to which a steering wheel is attached and is supported so as to be swingable by a tilt pivot shaft, and a tilt bracket that is fixed to a vehicle body side member and that holds the steering column so that it can be tilted. And an electric actuator for tilting the steering column, the electric actuator being rotatably supported by the tilt bracket via a bearing so as to extend in the vertical direction, and a screw shaft A screwed nut, a vertical movement transmitting means for transmitting the vertical movement of the nut to the steering column, and forward / reverse driving of the electric motor are transmitted to the screw shaft as rotation in the forward / reverse direction. In the electric tilt type steering apparatus provided with the rotation transmission mechanism,
The bearing comprises an upper bearing that supports an upper end shaft portion of the screw shaft, and a lower bearing that supports a lower end shaft portion of the screw shaft,
The upper bearing rotatably supports the upper end shaft portion while receiving an axial load acting on the screw shaft, and the lower bearing supports the lower end shaft portion rotatably without receiving the axial load. An electric tilt type steering apparatus characterized by the above. The upper bearing is constituted by a radial ball bearing having an inner ring and an outer ring whose shaft core extends in the vertical direction,
The inner ring of the upper bearing is inserted into the upper end shaft portion with the relative movement in the axial direction being restricted by the inner ring fixing means, and the outer ring of the upper bearing is close to the vehicle body side member of the tilt bracket by the outer ring fixing means. 2. The electric tilt type steering apparatus according to claim 1, wherein the electric tilt type steering apparatus is arranged such that relative movement in the axial direction with respect to the portion is restricted.   The inner ring fixing means is attached to a spacer fixed to the base portion of the upper end shaft portion and abutting against the lower surface of the inner ring, and an annular groove formed on the outer periphery on the distal end side of the upper end shaft portion, and contacts the upper surface of the inner ring. 3. The electric tilt type steering apparatus according to claim 2, wherein the electric tilt type steering apparatus is a detachable engaging member that comes into contact therewith.   The electric tilt type steering apparatus according to claim 3, wherein the engaging member is a C-ring.   The inner ring fixing means includes a screw portion of the screw shaft that is positioned at a base portion of the upper end shaft portion and is locked by the inner ring, a male screw portion formed on a distal end side of the upper end shaft portion, and a threaded engagement with the male screw portion. The electric tilt type steering apparatus according to claim 2, further comprising a fixing nut that abuts on an upper surface of the inner ring.   The electric tilt type steering apparatus according to claim 2, wherein the inner ring fixing means is configured such that the upper end shaft portion is press-fitted into an inner ring of the upper bearing.   The outer ring fixing means is mounted in an annular groove on a recess formed on a portion of the tilt bracket adjacent to the vehicle body side member and in contact with an upper surface of the outer ring, and an annular groove formed on an opening peripheral edge of the recess. The electric tilt type steering apparatus according to any one of claims 2 to 6, wherein the electric tilt type steering apparatus is a detachable engaging member that comes into contact with a lower surface of the outer ring.   The electric tilt type steering apparatus according to claim 7, wherein the engaging member is a C-ring.   The C-ring is a member having a tapered section that gradually increases in thickness from the inner diameter side toward the outer diameter side, which restricts axial movement of the upper bearing with respect to the upper end shaft portion. The electric tilt-type steering apparatus according to claim 4 or claim 8.   The electric motor according to any one of claims 2 to 7, wherein the outer ring fixing means is a recess formed in a portion of the tilt bracket adjacent to the vehicle body side member and into which the outer ring is press-fitted. Tilt-type steering device.   The outer ring fixing means is a recess formed at a portion of the tilt bracket adjacent to the vehicle body side member and abutted against the lower surface of the outer ring, and a fixing member fixed within the recess and abutted against the upper surface of the outer ring. The electric tilt type steering apparatus according to any one of claims 2 to 7, wherein   The outer ring fixing means is formed at a portion close to the vehicle body side member of the tilt bracket and formed with a reduced diameter by caulking the opening peripheral edge of the recess with a concave portion with which the upper surface of the outer ring contacts. The electric tilt type steering device according to any one of claims 2 to 7, wherein the electric tilt type steering device is a caulking portion that abuts against a lower surface of the outer ring.

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