阅读说明：本技术 转向装置 (Steering device ) 是由 白石善纪 于 2018-06-13 设计创作，主要内容包括：有关本发明的一技术方案的转向装置具备外轴杆、内轴杆(41)、外柱和内柱(22)。内轴杆(41)具有：滑动部(51),能够进入到外轴杆内；以及轴承装接部(52),与滑动部(51)在轴向上相连,不进入外轴杆内。后侧轴承(61、62)在轴承装接部(52)在轴向上隔开间隔而配置。(A steering device according to one aspect of the present invention includes an outer shaft, an inner shaft (41), an outer column, and an inner column (22). The inner shaft (41) has: a sliding part (51) which can enter the outer shaft rod; and a bearing attachment portion (52) axially connected to the sliding portion (51) and not entering the outer shaft. The rear bearings (61, 62) are disposed at intervals in the axial direction at the bearing attachment portion (52).)

1. A steering device is characterized in that a steering wheel is provided,

the disclosed device is provided with:

an outer shaft lever;

an inner shaft inserted into the outer shaft so as to be movable in a shaft axis direction with respect to the outer shaft, and to which a steering wheel is attached;

an outer column that supports the outer shaft via a front bearing so as to be rotatable about the shaft axis; and

an inner column that is rotatably supported via a rear bearing about the rod axis and is inserted into the outer column so as to be movable in the rod axis direction with respect to the outer column;

the inner shaft has:

an entry region accessible into the outer shaft; and

a non-entry region which is connected to the entry region in the axial direction of the shaft and does not enter the outer shaft;

the rear bearing includes a 1 st bearing and a 2 nd bearing disposed at an interval in the axial direction of the shaft in the non-entry region.

2. Steering device according to claim 1,

at least one of the front bearing, the 1 st bearing and the 2 nd bearing is a resin bush.

3. Steering device according to claim 1,

the 1 st bearing is positioned in front of the 2 nd bearing in the vehicle body;

a 1 st stopper that abuts against an outer ring of the 1 st bearing in the axial direction of the rod is formed in a portion of the inner column located forward of the vehicle body with respect to the 1 st bearing;

a 2 nd stopper that abuts against an outer ring of the 2 nd bearing in the axial direction of the rod is formed in a portion of the inner column located rearward of the vehicle body with respect to the 2 nd bearing.

4. Steering device according to any one of claims 1 to 3,

the non-entry region is formed to have a larger diameter than the entry region.

5. Steering device according to any one of claims 1 to 4,

the entry region is formed in a hollow cylindrical shape;

the non-entry region is formed in a solid cylindrical shape.

6. Steering device according to any one of claims 1 to 5,

a key lock collar externally fitted to the outer shaft to restrict rotation of the outer shaft relative to the outer column in a locked state;

the outer diameter of the key lock collar is smaller than the inner diameter of the inner post.

7. A steering device is characterized in that a steering wheel is provided,

the disclosed device is provided with:

a front side shaft lever;

a rear shaft located at the rear of the vehicle body with respect to the front shaft, configured to be movable in a shaft axis direction with respect to the front shaft, and to which a steering wheel is attached;

a front pillar that supports the front shaft via a front bearing so as to be rotatable about the shaft axis; and

a rear side column configured to rotatably support the rear side shaft around the shaft axis via a rear bearing and to be movable in the shaft axis direction with respect to the front side column;

the rear bearing has a 1 st bearing and a 2 nd bearing disposed at a predetermined interval in the axial direction of the spindle;

the distance between the 1 st bearing and the 2 nd bearing in the axial direction of the shaft is set to be 40mm or less.

8. A steering device is characterized in that a steering wheel is provided,

the disclosed device is provided with:

a steering shaft having a steering wheel mounted at a rear end thereof;

a rear bearing supporting the steering shaft;

a front bearing for supporting the steering shaft in front of the rear bearing; and

a steering column that supports the steering shaft via the rear bearing and the front bearing so as to be rotatable about a shaft axis;

the rear bearing has a 1 st bearing and a 2 nd bearing disposed at a predetermined interval in the axial direction of the spindle;

the distance between the 1 st bearing and the 2 nd bearing in the axial direction of the shaft is set to be 40mm or less.

Technical Field

The present invention relates to a steering device.

The present application claims priority based on japanese patent application No. 2017-116603 filed on 6/14/2017, the contents of which are incorporated herein by reference.

Background

Some steering devices have a telescopic function. The telescopic function adjusts the front-rear position of the steering wheel according to the difference in physique and driving posture of the driver. This type of steering device includes an outer column attached to a vehicle body, and an inner column inserted into the outer column and movable relative to the outer column. For example, in the structure of patent document 1 described below, an outer shaft is rotatably supported via a bearing in an inner column. A steering wheel is mounted at the rear end of the outer shaft lever. The inner shaft is rotatably supported in the outer column via a bearing. The inner shaft is inserted within the outer shaft.

According to the structure of patent document 1, the inner column and the outer shaft move in the axial direction with respect to the outer column and the inner shaft, respectively, during the expansion and contraction operation. In the structure of patent document 1, the outer shaft is positioned behind the vehicle body and is supported by bearings at both axial ends. Therefore, the structure of patent document 1 can improve the vibration rigidity.

Disclosure of Invention

Problems to be solved by the invention

However, in the steering apparatus, there is room for improvement in terms of securing a stroke amount at the time of expansion and contraction operation and at the time of secondary collapse (collapse) (stroke at the time of secondary collision), and obtaining a desired vibration rigidity.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a steering device capable of obtaining a desired vibration rigidity while ensuring a stroke amount.

Means for solving the problems

In order to solve the above problems, the present invention adopts the following technical means.

(1) A steering device according to an aspect of the present invention includes: an outer shaft lever; an inner shaft inserted into the outer shaft so as to be movable in a shaft axis direction with respect to the outer shaft, and to which a steering wheel is attached; an outer column that supports the outer shaft via a front bearing so as to be rotatable about the shaft axis; and an inner column that is rotatably supported via a rear bearing about the rod axis and is inserted into the outer column so as to be movable in the rod axis direction with respect to the outer column. The inner shaft has: an entry region accessible into the outer shaft; and a non-entry region which is connected to the entry region in the axial direction of the shaft and does not enter the outer shaft. The rear bearing includes a 1 st bearing and a 2 nd bearing disposed at an interval in the axial direction of the shaft in the non-entry region.

The steering device according to the present invention is configured to rotatably support an outer shaft in an outer column and rotatably support an inner shaft in an inner column. According to this structure, even when the attachment member such as the key lock collar is fitted to the outside of the outer rod positioned in front of the vehicle body, the attachment member can be prevented from being arranged on the movement locus of the inner column or the inner rod. Therefore, interference between the inner column and the inner rod and the attachment member can be suppressed during the stroke such as the expansion and contraction operation and the secondary collapse. Thus, the stroke amounts of the inner column and the inner shaft can be secured as compared with a conventional structure in which the inner shaft is rotatably supported in the outer column located at the front of the vehicle body and the outer shaft is rotatably supported in the inner column located at the rear of the vehicle body.

In particular, in the present invention, the 1 st bearing and the 2 nd bearing are disposed in the non-entry region that does not enter the outer shaft during the expansion and contraction operation and the secondary collapse. With this configuration, the bearing positioned in front of the vehicle body among the bearings can be prevented from interfering with the outer shaft or the peripheral member of the outer shaft during the stroke. The displacement of the inner shaft is suppressed, and the inner shaft is stably supported. This can improve the vibration rigidity.

Therefore, in the present invention, a desired vibration rigidity can be obtained while securing the stroke amount.

(2) In the steering device according to the aspect (1), it is preferable that at least one of the front bearing, the 1 st bearing, and the 2 nd bearing is a resin bush.

According to the technical scheme, the steering device can be simplified.

(3) In the steering device according to the above-described aspect (1), it is preferable that the 1 st bearing is located forward of the 2 nd bearing with respect to the vehicle body. Preferably, a 1 st stopper that abuts against an outer race of the 1 st bearing in the axial direction of the rod is formed in a portion of the inner column located forward of the vehicle body with respect to the 1 st bearing. Preferably, a 2 nd stopper that abuts against an outer race of the 2 nd bearing in the axial direction of the rod is formed in a portion of the inner column located rearward of the vehicle body with respect to the 2 nd bearing.

According to this aspect, since the positional deviation of the 1 st bearing and the 2 nd bearing with respect to the axial direction of the stem of the inner column can be suppressed, the steering stem can be prevented from coming loose.

In particular, the steering shaft is prevented from coming loose by the stopper formed in the inner column, and thus, a separate snap ring or the like is not required for fixing the outer ring. Therefore, the number of components can be reduced.

(4) In the steering device according to any one of the above (1) to (3), the non-entering region is preferably formed to have a larger diameter than the entering region.

According to the present invention, since the rigidity of the inner shaft can be improved, the vibration rigidity can be improved.

In the present invention, by forming only the non-entry region with a large diameter, the weight increase associated with the increase in diameter can be suppressed as much as possible, compared to the case where the entire inner shaft is formed with a large diameter.

(5) In the steering device according to any one of the above (1) to (4), preferably, the entrance area is formed in a hollow cylindrical shape. Preferably, the non-entry region is formed in a solid cylindrical shape.

According to the present invention, since the rigidity of the inner shaft can be improved, the vibration rigidity can be improved.

In particular, in the present invention, by forming only the non-entry region to be solid, the weight increase associated with the solid inner shaft can be suppressed as much as possible, compared to the case where the entire inner shaft is formed to be solid.

(6) In the steering device according to any one of the above items (1) to (5), it is preferable that a key lock collar that restricts rotation of the outer shaft with respect to the outer column in a locked state is fitted to the outer shaft. The outer diameter of the key locking collar is preferably smaller than the inner diameter of the inner post.

According to the present invention, interference between the inner column and the key lock collar can be reliably suppressed at the time of stroke of the inner column regardless of the location where the key lock collar is disposed. This ensures the stroke amount of the inner column.

(7) A steering device according to an aspect of the present invention includes: a front side shaft lever; a rear shaft located at the rear of the vehicle body with respect to the front shaft, configured to be movable in a shaft axis direction with respect to the front shaft, and to which a steering wheel is attached; a front pillar that supports the front shaft via a front bearing so as to be rotatable about the shaft axis; and a rear side column that supports the rear side shaft via a rear bearing so as to be rotatable about the shaft axis and is configured to be movable in the shaft axis direction relative to the front side column. The rear bearing includes a 1 st bearing and a 2 nd bearing arranged at a predetermined interval in the axial direction of the spindle. Preferably, a distance between the 1 st bearing and the 2 nd bearing in the axial direction of the spindle is set to 40mm or less.

(8) A steering device according to an aspect of the present invention includes: a steering shaft having a steering wheel mounted at a rear end thereof; a rear bearing supporting the steering shaft; a front bearing for supporting the steering shaft in front of the rear bearing; and a steering column that supports the steering shaft via the rear bearing and the front bearing so as to be rotatable about a shaft axis. The rear bearing includes a 1 st bearing and a 2 nd bearing arranged at a predetermined interval in the axial direction of the spindle. Preferably, a distance between the 1 st bearing and the 2 nd bearing in the axial direction of the spindle is set to 40mm or less.

The inventors of the present invention have studied to achieve the above object and found that: the ratio of the change in the vibration rigidity in the range in which the distance between the 1 st bearing and the 2 nd bearing is longer than 40mm is smaller than the ratio of the change in the vibration rigidity in the range in which the distance is 40mm or less. That is, it is found that if the distance exceeds the predetermined range, even if the distance is increased thereafter, it is estimated that the vibration rigidity is not greatly improved.

Therefore, according to the present invention, the distance between the 1 st bearing and the 2 nd bearing is set to 40mm or less, whereby a desired vibration rigidity can be obtained. By setting the distance between the 1 st bearing and the 2 nd bearing to 40mm or less, the stroke amount when the front side shaft and the front side column and the rear side shaft and the rear side column move in the shaft axis direction can be secured.

Effects of the invention

According to the aspects of the present invention, a desired vibration rigidity can be obtained while securing a stroke amount.

Drawings

Fig. 1 is a sectional view of a steering device according to embodiment 1.

Fig. 2 is an enlarged sectional view of the steering device according to embodiment 1.

Fig. 3 is an enlarged sectional view of the steering device according to embodiment 2.

Fig. 4 is a graph showing a relationship between the distance D between the 1 st bearing and the 2 nd bearing and the vibration rigidity.

Fig. 5 is an enlarged sectional view of the steering device according to embodiment 3.

Detailed Description

Next, embodiments of the present invention will be described with reference to the drawings.

(embodiment 1)

Fig. 1 is a sectional view of a steering device 1.

As shown in fig. 1, the steering device 1 is mounted on a vehicle. The steering device 1 adjusts the rudder angle of the wheels in accordance with the rotating operation of the steering wheel 2. In the following description, directions such as front, rear, up, down, left, and right are directions in a state of being mounted on a vehicle unless otherwise specified. In this case, arrow UP indicates the upward direction and arrow FR indicates the forward direction in the drawing.

The steering device 1 mainly includes a column unit 11 and a steering shaft 12. The column unit 11 and the steering shaft 12 are each formed in a cylindrical shape extending along the axis O. Therefore, in the following description, the direction in which the axis O of the column unit 11 and the steering stem 12 extends may be simply referred to as an axial direction (stem axial direction), the direction perpendicular to the axis O may be referred to as a radial direction, and the direction around the axis O may be referred to as a circumferential direction.

The steering device 1 of the present embodiment is mounted on a vehicle in a state where the axis O intersects with the front-rear direction. Specifically, the axis O of the steering device 1 extends upward as it goes rearward. However, in the following description, for convenience, the direction toward the steering wheel 2 in the axial direction of the steering device 1 is simply referred to as the rear direction, and the direction toward the opposite side from the steering wheel 2 is simply referred to as the front direction. In addition, the direction in the radial direction along the vertical direction in the state where the steering device 1 is mounted on the vehicle is simply referred to as the vertical direction.

< column Unit >

The column unit 11 has an outer column (front side column) 21 and an inner column (rear side column) 22.

The outer column 21 is formed in a cylindrical shape extending along the axis O. The outer column 21 is attached to the vehicle body via a bracket (not shown). An outer ring of the front bearing 28 is fitted (press-fitted) to a front end portion in the outer column 21.

The inner column 22 is formed in a cylindrical shape extending along the axis O. Specifically, the inner column 22 has a column small-diameter portion 24, a column large-diameter portion 25, and a connecting portion 26. The column large diameter portion 25 is located rearward of the column small diameter portion 24. The connecting portion 26 connects the column small-diameter portion 24 and the column large-diameter portion 25.

The outer diameter of the post small-diameter portion 24 is smaller than the inner diameter of the outer post 21. The column small-diameter portion 24 is inserted into the outer column 21 from the rear of the outer column 21. The inner column 22 is configured to be movable in the axial direction with respect to the outer column 21 while the outer peripheral surface of the column small diameter portion 24 slides on the inner peripheral surface of the outer column 21.

Fig. 2 is an enlarged sectional view of the steering device 1.

As shown in fig. 2, the connecting portion 26 connects the rear end edge of the column small-diameter portion 24 and the front end edge of the column large-diameter portion 25. In the illustrated example, the outer diameter of the connecting portion 26 gradually increases toward the rear. However, the connecting portion 26 may be orthogonal to the axis O.

The column large diameter portion 25 extends rearward from the rear end edge of the connecting portion 26. The outer diameter of the column large diameter portion 25 is larger than the inner diameter of the outer column 21. In the inner column 22 of the present embodiment, the column small-diameter portion 24 is an entry region into which the outer column 21 can enter. In the inner column 22, the column large diameter portion 25 and the connecting portion 26 are non-entry regions that cannot enter the outer column 21.

The front end of the column large diameter portion 25 constitutes a thick portion 25a having an inner diameter larger than a portion located rearward of the front end (hereinafter referred to as a thin portion 25 b). A step surface (1 st stopper) 25c orthogonal to the axis O is formed at a boundary portion between the thick portion 25a and the thin portion 25 b. The outer diameter and the inner diameter of the column large diameter portion 25 can be appropriately changed as long as the column large diameter portion has at least the stepped surface 25 c.

< steering shaft >

As shown in fig. 1, the steering shaft 12 includes an outer shaft (front shaft) 40 and an inner shaft (rear shaft) 41.

The outer shaft 40 is formed in a hollow cylindrical shape extending along the axis O. The outer shaft 40 is inserted within the outer post 21. A gap is provided between the outer peripheral surface of the outer shaft 40 and the inner peripheral surface of the outer column 21 in the radial direction. The rear end of the outer shaft 40 enters the inner post 22. The front end of the outer shaft 40 is press-fitted into the inner race of the front bearing 28. Thereby, the outer shaft 40 is supported rotatably about the axis O inside the outer column 21 via the front bearing 28. The front end of the outer shaft 40 projects forward from the outer column 21. The front end portion (portion protruding forward from the outer column 21) of the outer shaft 40 is coupled to, for example, a steering gear box (not shown) via a free joint (not shown) or the like.

A key lock collar 45 is fitted to the outside of the outer shaft 40 at an axially intermediate portion thereof (fitted to the outer peripheral surface of the outer shaft 40). The key locking collar 45 is formed in a cylindrical shape. The key locking collar 45 has an outer diameter smaller than the inner diameter of the post small diameter portion 24. A groove 46 extending in the axial direction is formed in the key lock collar 45. The groove portion 46 is formed in plurality at intervals in the circumferential direction. A slit 48 is formed in the outer column 21 at a portion located below the key lock collar 45 to pass through the outer column 21. When the vehicle is turned off, the locking member (not shown) passes through the slit 48 and enters one of the groove portions 46 (locked state). Thereby, the rotation of the steering shaft 12 with respect to the column unit 11 is restricted.

The inner shaft 41 is formed in a hollow cylindrical shape extending along the axis O. Specifically, the sliding portion (entering region) 51, the bearing attachment portion (non-entering region) 52, and the disk coupling portion (non-entering region) 53 are connected from the front to the rear to form the inner shaft 41. In the present embodiment, the sliding portion 51, the bearing attachment portion 52, and the disk coupling portion 53 are formed to have the same diameter.

The sliding portion 51 is inserted into the outer shaft 40 from the rear. The inner shaft 41 is configured to be movable in the axial direction relative to the outer shaft 40 while the outer peripheral surface of the sliding portion 51 slides on the inner peripheral surface of the outer shaft 40 in accordance with the axial movement of the inner column 22 relative to the outer column 21. Further, male splines (not shown) are formed on the outer peripheral surface of the sliding portion 51, for example. The male spline is engaged with a female spline (not shown) formed on the inner circumferential surface of the outer shaft 40. As a result, the inner shaft 41 moves in the axial direction relative to the outer shaft 40 while the relative rotation with respect to the outer shaft 40 is restricted. However, the telescopic structure and the rotation restricting structure of the steering shaft 12 may be appropriately modified.

The disc coupling portion 53 protrudes rearward from the inner column 22. The steering wheel 2 is connected to the wheel connecting portion 53.

As shown in fig. 2, rear bearings 61, 62 are attached to both axial end portions of the bearing attachment portion 52. Thereby, the inner shaft 41 is configured to be rotatable about the axis O with respect to the inner column 22.

The rear bearings 61 and 62 are a 1 st bearing 61 and a 2 nd bearing 62 located rearward of the 1 st bearing 61. The inner rings of the rear bearings 61 and 62 are press-fitted into the bearing attachment portion 52 with the spacer 65 interposed between the rear bearings 61 and 62. The spacer 65 is formed in a cylindrical shape surrounding the inner shaft 41. Both end surfaces of the spacer 65 in the axial direction abut against the inner rings of the rear bearings 61 and 62, respectively. In addition, the spacer 65 may be integrally formed with the inner shaft 41.

The outer ring of each of the rear bearings 61 and 62 is press-fitted into the thin portion 25b of the column large diameter portion 25. The outer ring of the 1 st bearing 61 abuts against the stepped surface 25c from the rear. On the other hand, a caulking portion (2 nd stopper) 67 formed at the rear end portion of the column large diameter portion 25 abuts against the outer ring of the 2 nd bearing 62 from the rear.

In the present embodiment, the distance D between the rear bearings 61 and 62 (the distance between the rear bearings 61 and 62) is preferably set to 40mm or less, and more preferably set to 20mm to 40 mm.

The steering device 1 of the present embodiment includes a telescopic adjustment mechanism (not shown). The telescopic adjustment mechanism is switched between a locked state in which the axial movement of the inner column 22 (inner shaft 41) relative to the outer column 21 (outer shaft 40) is restricted, and an unlocked state in which the axial movement is allowed. The telescopic adjustment mechanism fastens the inner column 22 via the outer column 21 in a locked state, for example. Thereby, the movement of the inner column 22 relative to the outer column 21 is restricted.

On the other hand, the telescopic adjustment mechanism releases the fastening of the inner column 22 in the lock released state. Thereby, the movement of the inner column 22 relative to the outer column 21 is permitted. For example, in the unlocked state, the steering wheel 2 is pushed forward, whereby the steering wheel 2 moves forward together with the inner column 22 and the inner shaft 41. In the unlocked state, the steering wheel 2 is pulled in rearward, whereby the steering wheel 2 moves rearward together with the inner column 22 and the inner rod 41. Then, by switching the telescopic adjustment mechanism to the locked state again, the front-rear position of the steering wheel 2 can be set to an arbitrary position.

At the time of a secondary collision, a collision load directed forward is applied to the steering wheel 2 from the driver. When the collision load is equal to or greater than a predetermined value, the steering wheel 2 moves forward relative to the outer column 21 (outer shaft 40) together with the inner column 22 and the inner shaft 41. At this time, the impact load applied to the driver at the time of a secondary collision is relaxed by the sliding resistance between the outer column 21 and the inner column 22.

However, in the structure of patent document 1, the inner rod is rotatably supported in the outer column disposed at the front of the vehicle body, and the outer rod is rotatably supported in the inner column disposed at the rear of the vehicle body. In this case, if an attachment member such as a key lock collar is attached to the front of the vehicle body, there is a possibility that the attachment member interferes with the outer shaft when the inner column (outer shaft) advances. Therefore, in the structure of patent document 1, it is difficult to secure the stroke amount in the expansion and contraction operation and the secondary collapse.

Therefore, in the present embodiment, the outer rod 40 is rotatably supported in the outer column 21 disposed at the front of the vehicle body, and the inner rod 41 is rotatably supported in the inner column 22 disposed at the rear of the vehicle body.

According to this structure, it is possible to suppress the attaching member (e.g., the key lock collar 45 or the like) from being arranged on the moving locus of the inner column 22 or the inner shaft 41. Therefore, during the stroke such as the expansion and contraction operation and the secondary collapse, the interference between the inner column 22 and the inner rod 41 and the attachment member can be suppressed. This can ensure the stroke amounts of the inner column 22 and the inner shaft 41 as compared with the conventional art.

In particular, in the present embodiment, the rear bearings 61 and 62 are attached to the bearing attachment portion 52 with a gap therebetween in the axial direction.

According to this configuration, the plurality of rear bearings 61 and 62 can be attached to the rear portion of the inner shaft 41 at a portion that does not enter the outer shaft 40 during the expansion and contraction operation and the secondary collapse. This can prevent the 1 st bearing 61 from interfering with the outer shaft 40 or the peripheral member of the outer shaft 40 during the stroke. The displacement of the inner shaft 41 is suppressed by the rear bearings 61 and 62, and the inner shaft 41 is stably supported. This can improve the vibration rigidity.

Therefore, in the present embodiment, a desired vibration rigidity can be obtained while securing the stroke amount.

In the present embodiment, the outer diameter of the key lock collar 45 is smaller than the inner diameter of the inner column 22.

According to this configuration, interference between the inner column 22 and the key lock collar 45 can be reliably suppressed at the time of stroke of the inner column 22 regardless of the position where the key lock collar 45 is disposed. This ensures the stroke amount of the inner column 22.

(embodiment 2)

Next, embodiment 2 of the present invention will be explained. Fig. 3 is an enlarged sectional view of the steering device 100 according to embodiment 2. The present embodiment is different from the above-described embodiments in that the bearing attaching portion 52 is formed to have a larger diameter than the sliding portion 51. In the following description, the same reference numerals are given to the same components as those of the above-described embodiment, and the description thereof is omitted.

In the steering device 100 shown in fig. 3, the inner shaft 41 has a cylindrical portion 101 and a solid portion 102. The cylinder 101 constitutes the sliding portion 51. The solid portion 102 is joined to the rear end portion of the tube portion 101. The solid portion 102 constitutes the bearing attaching portion 52 and the disk attaching portion 53. That is, in the present embodiment, the sliding portion 51 is formed in a hollow cylindrical shape as in the above-described embodiment 1. On the other hand, the bearing attachment portion 52 and the disk coupling portion 53 are integrally formed in a solid cylindrical shape.

The bearing attachment portion 52 has small diameter portions (the 1 st small diameter portion 110 and the 2 nd small diameter portion 111) located at both end portions in the axial direction, and a large diameter portion 112 located between the small diameter portions 110 and 111.

The outer diameters of the small diameter portions 110 and 111 are larger than the outer diameter of the sliding portion 51.

A 1 st boundary surface 114 orthogonal to the axis O is formed at a boundary portion between the 1 st small diameter portion 110 and the large diameter portion 112.

On the other hand, a 2 nd boundary surface 115 perpendicular to the axis O is formed at a boundary portion between the 2 nd small diameter portion 111 and the large diameter portion 112.

The 1 st small diameter portion 110 is fitted around the inner ring of the 1 st bearing 61 (fitted to the outer peripheral surface of the 1 st small diameter portion 110). The inner ring of the 1 st bearing 61 hits the 1 st boundary surface 114 from the front. On the other hand, the outer ring of the 1 st bearing 61 abuts against the stepped surface 25c from the rear.

The 2 nd small diameter portion 111 is fitted around the inner ring of the 2 nd bearing 62 (fitted to the outer peripheral surface of the 2 nd small diameter portion 111). The inner race of the 2 nd bearing 62 hits against the 2 nd boundary surface 115 from the rear. On the other hand, the outer ring of the 2 nd bearing 62 abuts against the caulking portion 67 from the front.

In the present embodiment, the distance D (the length in the axial direction of the large diameter portion 112) between the rear bearings 61 and 62 is also preferably set to 40mm or less, and more preferably set to 20mm to 40 mm.

The method of assembling the inner shaft 41 to the inner column 22 is as follows.

First, the 1 st bearing 61 is press-fitted into the 1 st small diameter portion 110. Subsequently, the inner shaft 41 is pushed into the inner column 22 from behind. The inner shaft 41 is pressed in until the outer race of the 1 st bearing 61 abuts against the step surface 25 c. Thereby, the 1 st bearing 61 is press-fitted into the inner column 22.

Next, the 2 nd bearing 62 is press-fitted into between the 2 nd small diameter portion 111 and the thin wall portion 25b of the inner column 22 from behind. Then, the rear end portion of the inner column 22 is caulked to form a caulked portion 67. Thereby, the inner shaft 41 is rotatably assembled to the inner column 22.

With this configuration, positional deviation of the rear bearings 61 and 62 with respect to the axial direction of the inner post 22 can be suppressed, and loosening of the inner shaft 41 can be prevented.

In particular, the stepped surface 25c and the caulking portion 67 formed in the inner column 22 prevent the steering stem 12 from coming loose, and thus it is not necessary to separately use a snap ring or the like for fixing the outer ring. Therefore, the number of components can be reduced.

The disk connecting portion 53 is provided so as to gradually decrease in diameter from the rear end edge of the 2 nd small-diameter portion 111 toward the rear and then extend further rearward. The steering wheel 2 is coupled to a rear end of the wheel coupling portion 53.

In the present embodiment, the bearing attaching portion 52 is formed by the solid portion 102.

According to this structure, since the rigidity of the bearing attachment portion 52 can be improved, the vibration rigidity can be further improved.

In particular, in the present embodiment, only the bearing attachment portion 52 and the disk coupling portion 53 are formed by the solid portion 102. Thus, in the present embodiment, the increase in weight associated with the use of the solid portion 102 can be suppressed as much as possible, compared to the case where the entire inner shaft 41 is formed solid.

In the present embodiment, the bearing attachment portion 52 has an outer diameter larger than that of the sliding portion 51.

According to this configuration, since the rigidity of the inner shaft 41 can be improved, the vibration rigidity can be improved.

In the present embodiment, only the bearing attachment portion 52 is formed to have a large diameter. Thus, in the present embodiment, the increase in weight associated with the increase in diameter can be suppressed as much as possible, compared to the case where the entire inner shaft 41 is formed to have a larger diameter.

In embodiment 2 described above, the case where the bearing attaching portion 52 and the disk connecting portion 53 are formed to be solid has been described, but the present invention is not limited to this configuration. At least one of the bearing attachment portion 52 and the disk connection portion 53 may be formed to be hollow.

In embodiment 2 described above, the structure in which the inner shaft 41 is made solid and has a larger diameter in order to ensure rigidity has been described, but the structure is not limited to this, and a part of the inner shaft 41 may be made thick.

Here, the inventors of the present application studied the relationship between the distance D between the rear bearings 61 and 62 and the vibration rigidity by simulation. Fig. 4 is a graph showing a relationship between the distance D and the vibration rigidity. In fig. 4, the solid line indicates the vibration rigidity in the left-right direction, and the broken line indicates the vibration rigidity in the up-down direction.

As shown in fig. 4, it is understood that the vibration rigidity becomes higher as the distance D increases. However, the rate of change in the vibration rigidity in the range where the distance D is longer than 40mm is smaller than the rate of change in the vibration rigidity in the range where the distance D is 40mm or less. That is, it is found that if the distance D exceeds the predetermined range, even if the distance D is increased thereafter, it is estimated that the vibration rigidity is not greatly improved.

Therefore, even if the portion of the inner shaft 41 located rearward of the sliding portion 51 is set as the bearing attachment portion 52 as in the present embodiment, it is not necessary to largely secure the axial length of the bearing attachment portion 52 in order to secure the vibration rigidity.

The distance D is preferably set as appropriate because the required vibration rigidity differs depending on the vehicle to be mounted. In the present embodiment, the distance D between the rear bearings 61 and 62 is set to be 20mm to 40 mm. Thus, while the 1 st bearing 61 is prevented from interfering with the attachment member to secure the stroke amount, a desired vibration rigidity can be obtained. The distance D is more preferably set to 25mm to 35 mm. This improves the balance between the weight and the vibration rigidity of the bearing attachment portion 52, and can improve the vibration rigidity without increasing the weight more than necessary. The steering shaft 12 is not limited to the structure including the outer shaft 40 and the inner shaft 41. Even with a configuration including a single steering column, desired vibration rigidity can be obtained by similarly setting the distance D between the rear bearings 61 and 62. That is, in the structure in which the steering column rotatably supports the steering column via the rear bearings 61 and 62 and the front bearing 28, it is also preferable that the rear bearings 61 and 62 are disposed apart from each other by the distance D.

(embodiment 3)

Next, embodiment 3 of the present invention will be explained. Fig. 5 is an enlarged sectional view of the steering device 200 according to embodiment 3. The present embodiment differs from the above-described embodiments in that a resin bush is used for at least one of the bearings (in the present embodiment, the 1 st bearing 61) of the rear bearings 61 and 62.

In the steering device 200 shown in fig. 5, the inner shaft 41 is formed in a hollow cylindrical shape over the entire axial direction. The inner shaft 41 has a cylindrical portion 201 and a support portion 202. The cylindrical portion 201 constitutes the sliding portion 51.

The support portion 202 extends rearward from the rear end of the tube portion 201. The support portion 202 constitutes the bearing attachment portion 52 and the disk attachment portion 53.

The bearing attachment portion 52 has tapered portions (first tapered portion 1 and second tapered portion 211) located at both end portions in the axial direction, and a large diameter portion 212 located between the tapered portions 210 and 211.

The 1 st tapered part 210 gradually expands in diameter toward the rear. The front end of the 1 st tapered part 210 is connected to the rear end of the tube 201. The rear end of the 1 st tapered portion 210 is connected to the front end of the large diameter portion 212.

The diameter of the second tapered portion 211 gradually increases toward the front. The front end of the second tapered portion 211 is connected to the rear end of the large diameter portion 212.

A reduced diameter portion 215 having an outer diameter smaller than that of a front portion (an enlarged diameter portion 214) is formed at a rear end portion of the large diameter portion 212. The rear end surface of the enlarged diameter portion 214 (the stepped surface between the enlarged diameter portion 214 and the reduced diameter portion 215) forms a 2 nd boundary surface 221 perpendicular to the axis O.

The inner column 22 has a column large diameter portion 225, a connecting portion 226, and a column small diameter portion 227. The post large diameter portion 225 is located forward of the post small diameter portion 227. The connecting portion 226 connects the rear end portion of the column large-diameter portion 225 and the front end portion of the column small-diameter portion 227.

The outer diameter of the column large-diameter portion 225 is smaller than the inner diameter of the outer column 21. The column large diameter portion 225 is inserted into the outer column 21 from the rear of the outer column 21.

As shown in fig. 5, the 1 st bearing 61 of the present embodiment is a resin bush. The 1 st bearing 61 is formed in a multi-stage cylindrical shape disposed coaxially with the axis O. Specifically, the 1 st bearing 61 includes a shaft support portion 231, a connecting cylinder 232, and a column support portion 233.

The stem support portion 231 is formed smaller in diameter than the column support portion 233. The stem support portion 231 surrounds the distal end of the large diameter portion 212 (the enlarged diameter portion 214). A sliding support portion 235 is formed on the inner peripheral surface of the stem support portion 231. The slide support portion 235 protrudes radially inward from the inner peripheral surface of the shaft support portion 231. The plurality of sliding support portions 235 are arranged at intervals in the circumferential direction. Each of the sliding support portions 235 slidably supports the outer peripheral surface of the large diameter portion 212. Therefore, the rod support portion 231 rotatably supports the inner rod 41 via the sliding support portion 235. The stem support 231 may directly support the inner stem 41.

The connecting tube 232 is gradually expanded in diameter toward the rear. The connecting cylinder 232 may connect the rod support 231 and the column support 233 to each other via a step.

The inner diameter of the column support 233 is larger than the outer diameter of the inner shaft 41. The outer diameter of the post support 233 is equal to or smaller than the inner diameter of the inner post 22 (post small diameter portion 227). Therefore, the outer peripheral surface of the column support portion 233 approaches or abuts the inner peripheral surface of the inner column 22 (the column small-diameter portion 227). The column support 233 has a positioning projection 240. The positioning protrusion 240 is formed in a hemispherical shape protruding outward in the radial direction from the column support 233. The positioning projection 240 is fitted into a positioning hole 241 formed in the inner column 22. Thereby, the 1 st bearing 61 is restricted from rotating about the axis O with respect to the inner column 22. In the present embodiment, a plurality of positioning protrusions 240 are arranged at intervals in the circumferential direction.

The 1 st bearing 61 is formed with a front slit 250 and a rear slit 251. Each slit 250, 251 extends in the axial direction. The slits 250, 251 are arranged alternately (staggered) in the circumferential direction.

The front slit 250 is open at the front end surface of the shaft support portion 231 and reaches the front of the column support portion 233 through the connecting cylinder 232.

The rear side slit 251 is open at the rear end surface of the column support 233 and reaches the rear of the spindle support 231 through the connecting cylinder 232.

In the 1 st bearing 61, portions (mainly, the stem support portion 231 and the connecting cylinder 232) located between the front side slits 250 adjacent in the circumferential direction are configured to be elastically deformable in the radial direction.

In the 1 st bearing 61, portions (mainly, the column support portions 233 and the connecting cylinder 232) located between the rear side slits 251 adjacent in the circumferential direction are configured to be elastically deformable in the radial direction.

The inner race of the 2 nd bearing 62 is press-fitted into the reduced diameter portion 215 of the inner shaft 41. The inner ring of the 2 nd bearing 62 abuts on the 2 nd boundary surface 221 from the rear.

The outer race of the 2 nd bearing 62 is pressed into the inner post 22. The caulking portion 67 abuts against the outer ring of the 2 nd bearing 62 from the rear.

In the present embodiment, the distance D between the rear bearings 61 and 62 (the distance between the rear bearings 230 and 62) is also preferably set to 40mm or less.

In the present embodiment, in addition to the same operational effects as those of the above-described embodiment, the structure can be simplified by using the resin bush for the 1 st bearing 61.

In the above embodiment, the case where the resin bush is used for the 1 st bearing 61 has been described, but the present invention is not limited to this configuration. At least one of the front bearing 28 and the rear bearing (the 1 st bearing 61 and the 2 nd bearing 62) may be configured by a resin bush. In the case where the 2 nd bearing 62 uses a resin bush, for example, it is preferable that the stem support portion 231 is assembled to the inner stem 41 in a state of being oriented rearward.

The preferred embodiments of the present invention have been described above, but the present invention is not limited to these embodiments. Additions, omissions, substitutions, and other changes in the structure can be made without departing from the spirit of the invention. The invention is not limited by the foregoing description, but is only limited by the appended claims.

For example, in the above-described embodiment, the description has been given of the structure in which the axis line O intersects the front-rear direction, but the present invention is not limited to this structure. The axis O may be aligned with the front-rear direction of the vehicle 3 or may be inclined in the left-right direction.

In the above-described embodiment, the configuration in which the outer column 21 supports the outer rod 40 and the inner column 22 supports the inner rod 41 behind the outer column 21 has been described, but the configuration is not limited to this configuration. For example, the outer column 21 may support the inner rod 41, and the inner column 22 may support the outer rod 40 at the rear of the outer column 21.

The outer column (rear side column) 21 may be located behind the inner column (front side column) 22. In this case, the outer column 21 may support one of the outer rod 40 and the inner rod 41 (rear rod). The inner column 22 may support the other (front side shaft) of the outer shaft 40 and the inner shaft 41.

In the above-described embodiment, the configuration in which the rear bearings 61 and 62 are disposed in the rear portion of the inner column 22 located at the vehicle body rear side has been described, but in the case where the outer column 21 is disposed at the vehicle body rear side, a configuration in which two front bearings are disposed may be employed. In this case, the distance between the front bearings is preferably set to 40mm or less, more preferably 20mm to 40mm, and still more preferably 25mm to 35 mm. This can provide a desired vibration rigidity while ensuring the stroke amount.

In the above-described embodiment, the configuration in which the key lock collar 45 is fitted to the outside of the outer shaft 40 has been described, but the present invention is not limited to this configuration. For example, the steering device 1 may be a structure without the key lock collar 45. The outer shaft 40 may be provided with an attachment member other than the externally fitted key locking collar 45.

In addition, the components of the above embodiment may be replaced with known components as appropriate without departing from the scope of the present invention, and the above modifications may be combined as appropriate.

Description of the reference numerals

1 … steering device

2 … steering wheel

21 … outer column (front side column, rear side column)

22 … inner column (rear side column, front side column)

25c … level difference surface (stop No. 1)

28 … front bearing

40 … external shaft rod (front shaft rod, rear shaft rod)

41 … inner shaft lever (rear shaft lever, front shaft lever)

45 … key locking collar

51 … sliding part (entering area)

52 … bearing attachment (non-entry area)

53 … disk junction (non-entry zone)

61 … bearing 1 (rear bearing)

62 … bearing 2 (rear bearing)

67 … caulking portion (2 nd stop).