JP2005343261A - Press fitting structure of steering column - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive press fitting structure of a steering column with a simple constitution without finishing capable of restraining loads from increasing on a joint face of a column and a press fitting part. <P>SOLUTION: In this press fitting structure of a steering column, a tip end of a column 20 holding a steering shaft is press fit/innerly or outerly fitted with a press fitting part 3 installed to a gear box 1. At least one of the press fitting part 3 or the column 20 is coupled under a partial contact condition having a tubular variant cross section. The cross sectional shape includes a polygonal shape, a shape having a plurality of long axial projections 31a in a peripheral direction, or a cylindrical shape having recessed grooves 23a correspondingly fitted with the projections 31a in a peripheral direction. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electric power steering device for an automobile, and more particularly to a press-fitting structure of a steering column formed by press-fitting and fitting a column into a press-fitting fitting portion of a gear box of a reduction gear for a steering electric power assist mechanism. .

  2. Description of the Related Art Conventionally, an electric power steering device used in an automobile steering system uses an in-vehicle battery as a power source for an electric motor, so that there is no direct engine drive loss and the electric motor is driven only at the time of steering assist. Therefore, it has the feature that the drive loss (decrease in driving fuel consumption) of the engine related to the alternator can be suppressed.

  A steering column of an electric power steering apparatus generally has a structure in which a gear box incorporating a mechanism for transmitting the drive of an electric motor to the steering shaft and a column for rotatably holding the steering shaft are integrally connected. Yes.

  FIG. 16 is a side sectional view (a), a gear box axial direction front view (b), and a column sectional view (c) showing a conventional press-fitting structure of a steering column (when the column is male).

For example, in Patent Document 1, as shown in FIG. 16, a steering column 10 having a structure in which a column 2 is press-fitted and fitted into a cylindrical press-fitting fitting portion 3 of a gear box 1 of a reduction gear for an electric power assist mechanism. Such a structure was common. The outer diameter R2 of the column 2 is set to be slightly larger than the inner diameter R1 of the press-fitting fitting portion 3 (R1 <R2).
JP 2000-121533 A

  However, in the conventional press-fitting structure of the steering column, when the column 2 is press-fitted into the press-fitting fitting portion 3 of the gear box 1, there is no shape relief with respect to the tightening margin. A large press-fit load is generated even if a slight tightening allowance is generated. For this reason, in order to obtain an ideal press-fitting load, high dimensional accuracy is required, and finishing work is required in the press-fitting fitting portion.

  However, regarding this finishing process, as shown in FIG. 16A, the edge of the inner peripheral surface of the gear box 1 needs to be processed from the direction of the arrow A, whereas the press-fit inner diameter of the column 2 is It must be processed (finished) from the direction of arrow B, and a special machine that can change the direction of the gear box 1 once or perform processing from both is required. There was a problem.

  The present invention improves the inconvenience of the above-described conventional example, can suppress an increase in load on the joint surface between the column and the press-fitting fitting portion, and does not require finishing, and has a low cost and simple configuration. The issue is to provide a press-fit structure for the column.

  In order to achieve the above object, in the present invention, in the press-fitting structure of the steering column, in which the front end portion of the column holding the steering shaft is press-fitted / internally fitted or externally fitted to the press-fitting fitting portion provided in the gear box, at least One of the press-fitting fitting part or the column has a cylindrical shape having an irregular cross section, and is joined by partial contact.

  In the press-fitting structure of the steering column of the present invention, it is preferable that one of the press-fitting fitting portion or the column has a polygonal cross-sectional shape and the other has a cylindrical shape.

  In the press-fitting structure of the steering column of the present invention, it is preferable that one of the press-fitting fitting portion or the column has a shape in which a plurality of projections long in the axial direction are provided in the circumferential direction, and the other has a cylindrical shape.

  In the press-fitting structure of the steering column according to the present invention, one of the press-fitting fitting portion or the column has a shape in which a plurality of axially long protrusions are provided in the circumferential direction, and the other has an arrangement corresponding to these protrusions. It is preferable that it is the cylindrical shape which provided the recessed groove of the shape to fit in the circumferential direction.

  In the steering column press-fitting structure of the present invention, it is preferable that the plurality of axially long protrusions provided in the one circumferential direction are arranged at unequal intervals in the circumferential direction.

  In the press-fitting structure of the steering column according to the present invention, the plurality of projections that are long in the axial direction provided at unequal intervals in the one circumferential direction have higher rigidity against bending of the steering column in the tilt adjustment direction than in the left-right direction. It is preferable that they are arranged as described above.

  In the press-fitting structure of the steering column of the present invention, the plurality of axially long projections provided at unequal intervals in the one circumferential direction have a rotational phase around one axis in the other concave groove. It is preferable that they are arranged so as to coincide with each other only.

  According to the present invention, when the column is press-fitted, since the fitting portion is in partial contact, the load applied to the tightening margin is less sensitive than before, and high accuracy is required to obtain a desired press-fit load. Never happen. Therefore, even if there is a large variation in the tightening allowance, a stable press-fit load can be obtained without increasing the press-fit load.

  In addition, the press-fitting fitting portion and the column can be press-fitted while being molded, and there is no need to perform finishing processing, which contributes to cost reduction.

  Embodiments of the present invention will be described with reference to the drawings.

  FIG. 15 is a side view of a steering column structure with an electric power assist mechanism that employs one of the cases where the column is a male of the embodiments of the present invention described below.

  In the steering column structure shown in FIG. 15, reference numeral 100 is a member for attaching a lever such as a winker, and the protrusion 102 formed integrally with the front end of the column 2 at the front end of the vehicle is a harness. It is a blanket to stop the coupler.

  A gear box 1 is attached to the vehicle front end of the column 2 as described later, and a lower column member 104 extends concentrically with the column 2 on the vehicle front side of the gear box 1.

  A steering shaft 105 is rotatably supported in the column 2, the gear box 1 and the lower column member 104, and a steering wheel (not shown) is attached to the vehicle rear end 105 a of the steering shaft 105.

  An electric motor M for power assist is attached below the gear box 1.

  FIG. 1 is a gearbox axial front view of a reduction gear for a steering electric power assist mechanism (a), side of a steering column press-fitting structure (when the column is a male) showing the first embodiment (1) of the present invention. It is sectional drawing (b) and column sectional drawing (c). Hereinafter, in all the drawings, the oblique lines of the column cross sections are omitted.

[First Embodiment (1)]
A first embodiment (1) of the present invention will be described. 1 (a) and 1 (b), the tip end portion of a column 20 is press-fitted and internally fitted into a cylindrical press-fitting fitting portion 3 provided to protrude from a gear box 1 of a reduction gear for a steering electric power assist mechanism. Thus, the steering column is configured as a whole. The column 20 is formed in a regular hexagonal shape as shown in FIG. The maximum outer diameter R2 of the column 20 is set to be slightly larger than the inner diameter R1 of the press-fitting fitting portion 3 (R1 <R2).

  In this press-fit structure, the hexagonal flat surface portion 20a of the column 20 does not come into contact with the inner peripheral surface of the press-fit fitting portion 3. Therefore, the flat surface portion 20a serves as a relief during press-fitting, and the hexagonal corner portions are press-fitted. A certain amount of elastic contact is given to the fitting part 3. For this reason, the load applied to the tightening allowance at the time of press-fitting is less sensitive than before, so that high accuracy is not required to obtain a desired press-fitting load.

  Therefore, the press-fitting fitting portion 3 and the column 20 can be stably press-fitted without performing finish processing while being molded.

  In addition, by setting only the inlet portion of the press-fitting fitting portion 3 so as to have a relationship of (R1> R2), the tip end portion of the column 20 can be easily inserted into the press-fitting fitting portion 3 and falls Thus, a stable press-fitting force can be obtained. In particular, in the molding of the press-fitting fitting portion 3 and the column 20, a draft is necessary, and this can be effectively used for the relationship (R1> R2).

  In this embodiment, the column 20 is hexagonal. However, the present invention is not limited to this, and it is considered that a desired effect can be obtained if the column 20 is a polygon having a square to octagonal position.

[First Embodiment (2)]
FIG. 2 is a front view (a) of a reduction gear for the steering electric power assist mechanism in the press-fitting structure of the steering column (when the column is a knife) showing the first embodiment (2), and a side sectional view ( It is b) and column sectional drawing (c).

  In the first embodiment (1), a hexagonal column 20 (male, hereinafter referred to as press fit) is fitted into a cylindrical press-fitting fitting portion 3 (female, hereinafter referred to as a “female”). 2 is press-fitted, but a cylindrical column 2 (female) can be press-fitted and externally fitted to a hexagonal press-fitting fitting 30 (male) as shown in FIG. The same effect as the above configuration can be expected.

  In the first embodiment (2), the cylindrical column 2 (female) is press-fitted and externally fitted to the polygonal press-fitting fitting part 30 (male), but the polygonal press-fitting fitting part (female) The same effect can be expected even if a cylindrical column 2 (female) is fitted and press-fitted into the inner surface side plane.

  FIG. 3: is a gear box axial front view (a) of the reduction gear for steering electric power assist mechanisms of the press-fitting structure of the steering column (column is male and protrusion is female side) which shows 2nd Embodiment (1). FIG. 4 is a side sectional view (b), a column sectional view (c), and FIG. 4 showing a modification of the second embodiment (1) of a steering column press-fitting structure (column is male and projection is female side). It is a gear box axial direction front view (a), side sectional view (b), and column sectional view (c).

  Next, a second embodiment will be described with reference to FIGS. This embodiment is substantially the same as the first embodiment described above, and the same members are denoted by the same reference numerals, and redundant description is omitted. The difference is that a plurality of axially long projections are provided on either the press-fitting portion of the gearbox 1 or the column, and the press-fitting load is merely abutting between the projections and the surface facing the projections. It is a point that gives rise to.

[Second Embodiment (1)]
First, a second embodiment (1) will be described with reference to FIG. In this embodiment, on the inner peripheral surface of the press-fitting fitting portion 31 (female) of the gear box 1, four axially long protrusions 31a are provided at equal intervals in the circumferential direction, and the column 2 (male) is usually used. It has a cylindrical shape. The outer diameter R2 of the column 2 is set to a minute amount (R1 <R2) larger than the inscribed circle diameter R1 of the protrusion 31a of the press-fitting fitting portion 31.

  In this press-fit structure, when the column 2 is press-fitted, the column 2 strongly abuts against the protrusion 31a of the press-fit fitting portion 31, but the portion 31b where the protrusion 31a of the press-fit fitting portion 31 is not provided becomes a relief and the column 2 2 gives a certain amount of elastic contact to the protrusion 31a. For this reason, the load applied to the tightening allowance during press-fitting is less sensitive than before, so high accuracy is not required to obtain the desired press-fitting load, and stable press-fitting is possible without performing finishing processing. It becomes.

  In other respects, the same effect as in the first embodiment can be expected, and a duplicate description is omitted.

  In the second embodiment (1), the protrusions 31a on the inner peripheral surface of the press-fitting fitting portion 31 (female) of the gear box 1 are provided at four locations at equal intervals in the circumferential direction, as shown in FIG. Although not equally spaced, the distance between the protrusions 31a positioned above and below can be narrowed so as to be symmetrical with respect to the axial center line.

  Even in this configuration, the same effect as that of the second embodiment (1) can be expected, but in particular, when the column 2 is press-fitted and fitted into the press-fitting fitting portion 31, the vertical direction of the column 2 is improved. Since bending rigidity becomes high, durability against tilt adjustment of the steering wheel can be enhanced.

[Second Embodiment (2)]
FIG. 5 is a front view (a) in a gear box axial direction of a reduction gear for a steering electric power assist mechanism of a steering column press-fitting structure (column is male and projection is male side) showing the second embodiment (2). FIG. 6 is a side sectional view (b), a column sectional view (c), and FIG. 6 of a steering column press-fitting structure (column is male and projection is male side) showing a modification of the second embodiment (2). It is a gear box axial direction front view (a), side sectional view (b), and column sectional view (c).

  In the second embodiment, the protrusion 31a is provided on the press-fitting portion 31 (female). However, the present invention is not limited to this, and as shown in FIG. Protrusions 21a are provided at four positions at intervals, and the press-fitting fitting portion 3 can be formed in a normal cylindrical shape. The circumscribed circle diameter R2 of the protrusion 21a of the column 2 is set to be slightly larger than the inner diameter R1 of the press-fit fitting portion 31 (R1 <R2). Even in this configuration, the same effect as in the above embodiment can be expected.

  In the second embodiment (2), the protrusions 21a on the outer peripheral surface of the column 21 are provided at four positions at equal intervals in the circumferential direction. However, as shown in FIG. The distance between the protrusions 21a to be narrowed can also be provided at a position that is symmetrical with respect to the axial center line. Even in this configuration, the same effect as that of the second embodiment (2) shown in FIG. 5 can be expected, and the bending rigidity in the vertical direction of the column 21 is increased. Can be increased.

[Second Embodiment (3)]
FIG. 7 is a front view (a) in the gearbox axial direction of the reduction gear for the steering electric power assist mechanism of the steering column press-fitting structure (the column is a knife and the protrusion is the knife side) showing the second embodiment (3). FIG. 8 is a side sectional view (b), a column sectional view (c), and FIG. 8 showing a modification of the second embodiment (3) of a steering column press-fitting structure (column is a knife and projection is a knife side). It is a gear box axial direction front view (a), side sectional view (b), and column sectional view (c).

  In the second embodiment (1) and (2), the columns 2 and 21 (male) are fitted in the press-fitting fitting portions 31 and 3, but in the second embodiment (3), the column 22 ( The female) is fitted on the press-fitting fitting portion 3. On the inner peripheral surface side of the column 22, projections 22a that are long in the axial direction are provided at equal intervals in the circumferential direction, and the press-fitting fitting portion 3 (male) has a normal cylindrical shape. The outer diameter R2 of the press-fitting fitting portion 3 is set to be slightly larger than the inscribed circle diameter R1 of the protrusion 22a of the column 22 (R1 <R2). Even in this configuration, the same effect as in the above embodiment can be expected.

  In the second embodiment (3), the protrusions 22a on the inner peripheral surface side of the column 22 are provided at four locations at regular intervals in the circumferential direction. However, as shown in FIG. The distance between the upper and lower protrusions 22a can be narrowed so as to be symmetrical with respect to the axial center line. Even in this configuration, the same effect as that of the second embodiment (3) can be expected, and the bending rigidity in the vertical direction of the column 22 is increased, so that the durability against tilt adjustment of the steering wheel can be enhanced. .

[Second Embodiment (4)]
FIG. 9 is a front view (a) in a gear box axial direction of a reduction gear for a steering electric power assist mechanism of a steering column press-fitting structure (a column is a female and a projection is a male side) showing the second embodiment (4). FIG. 10 is a side sectional view (b), a column sectional view (c), and FIG. 10 showing a modification of the second embodiment (4) of a steering column press-fitting structure (the column is a female and the projection is a male side). It is a gear box axial direction front view (a), side sectional view (b), and column sectional view (c).

  In the second embodiment (3) (FIG. 7), the protrusion 22a is provided on the column 22 (female) side, but not limited to this, as shown in FIG. 9, the press-fitting fitting portion 32 (male) side. The column 2 can be formed in a normal cylindrical shape by providing a protrusion 32a. The circumscribed circle diameter R2 of the protrusion 32a of the press-fitting fitting portion 32 is set to be slightly larger than the inner diameter R1 of the column 2 (R1 <R2). Even in this configuration, the same effect as in the above embodiment can be expected.

  In the second embodiment (4) (FIG. 9), the protrusions 32a on the outer peripheral surface of the press-fitting fitting portion 32 (female) of the gear box 1 are provided at four locations at equal intervals in the circumferential direction. As shown in FIG. 6, the distance between the protrusions 32a positioned vertically is narrow, but it can also be provided at a position that is symmetrical with respect to the axial center line. Even in this configuration, the same effect as in the second embodiment (4) can be expected, and the bending rigidity in the vertical direction of the column 2 in the drawing is increased, so that the durability against the steering wheel tilt adjustment is enhanced. Can do.

  FIG. 11 is a front view (a) in a gear box axial direction of a reduction gear for a steering electric power assist mechanism of a steering column press-fitting structure (column is male and projection is female) showing the third embodiment (1). FIG. 5 is a side sectional view (b) and an enlarged sectional view (c) of a column.

  Next, a third embodiment will be described with reference to FIGS. The third embodiment is substantially the same as the second embodiment, and the same members are denoted by the same reference numerals, and redundant description is omitted. The difference is that a plurality of protrusions provided on the press-fitting fitting part or column of the gear box 1 of the reduction gear for the steering electric power assist mechanism are located at the corresponding positions on the side facing the protrusions when pressed. This is a point where a recessed groove having a fitting shape is provided. When the column is press-fitted, the protrusion and the concave groove are fitted, and a press-fitting load is generated only by contact of this portion.

[Third embodiment (1)]
First, a third embodiment (1) will be described with reference to FIG. On the inner peripheral surface of the press-fitting fitting portion 33 (female) of the gear box 1 of the reduction gear for the steering electric power assist mechanism, three axially long projections 33a are provided at irregular intervals in the circumferential direction, and the cylinder The column 23 (male, enlarged view) having a shape is also provided with a groove 23a having a shape that fits the projection 33a at a position corresponding to the projection 33a of the press-fitting fitting portion 33. When the column 23 is press-fitted and fitted into the press-fitting fitting portion 33, the concave groove 23 a of the column 23 is fitted to the protrusion 33 a of the press-fitting fitting portion 33. The minimum outer diameter R2 of the concave groove 23a of the column 23 is set to a minute amount (R1 <R2) larger than the inscribed circle diameter R1 of the protrusion 33a of the press-fitting fitting portion 33.

  Further, the circumferential arrangement angles θ1, θ2, and θ3 of the protrusions 33a of the press-fitting fitting portion 33 have at least one angle as an unequal angle (θ1 = θ2 ≠ θ3, θ1 ≠ θ2 = θ3, or θ1 = θ3 ≠). θ2, or θ1 ≠ θ2 ≠ θ3), and the concave groove 23a of the column 23 is also set to an arrangement angle corresponding thereto.

  As a result, the phase around the axis of the column 23 coincides only at one place. Therefore, when the column 23 is press-fitted and fitted into the press-fit fitting portion 33, The position is determined and the assembly phase on the circumference is regulated. Therefore, when the column 23 is press-fitted, phase out using a jig becomes unnecessary.

  In this press-fitting structure, the concave groove 23a of the column 23 is fitted into the protrusion 33a of the press-fit fitting portion 33 and strongly abuts when the column 23 is press-fitted and fitted to the press-fit fitting portion 33. The portion 33b of the 33 where the protrusion 33a is not provided becomes a relief, and the column 23 gives a certain amount of elastic contact to the protrusion 33a. For this reason, the load applied to the tightening allowance during press-fitting is less sensitive than before, so high accuracy is not required to obtain the desired press-fitting load, and stable press-fitting is possible without performing finishing processing. It becomes.

  In other respects, the same effect as in the second embodiment (1) can be expected, and a duplicate description is omitted.

[Third embodiment (2)]
FIG. 12 is a front view (a) in a gear box axial direction of a reduction gear for a steering electric power assist mechanism of a steering column press-fitting structure (column is male, projection is male side) showing the third embodiment (2); It is side sectional drawing (b) and column sectional drawing (c).

  In the said 3rd Embodiment (1) (FIG. 11), although the protrusion 33a was provided in the press-fit fitting part 33 (female) side, as shown in FIG. 12, as shown in FIG. Protrusions 24a are provided at three locations at irregular intervals in the circumferential direction on the outer peripheral surface side, and a groove 34a is provided at a position corresponding to the protrusion 24a of the column 24 on the inner peripheral surface side of the press-fitting fitting portion 34. You can also. The circumscribed circle diameter R2 of the protrusion 24a of the column 24 is set to be a minute amount (R1 <R2) larger than the maximum inner diameter R1 of the concave groove 34a of the press-fitting fitting portion 34. Even in this configuration, the same effect as in the above embodiment can be expected.

[Third embodiment (3)]
FIG. 13 is a front view (a) in the gearbox axial direction of the reduction gear for the steering electric power assist mechanism of the steering column press-fitting structure (the column is a knife and the protrusion is the knife side) showing the third embodiment (3). FIG. 5 is a side sectional view (b) and an enlarged sectional view (c) of a column.

  In the third embodiment (1) and (2) (FIGS. 11 and 12), the columns 23 and 24 (both male) are fitted in the press-fitting fitting portions 33 and 34, but this third embodiment ( In 3), as shown in FIG. 13, the column 25 (female, enlarged view) is externally fitted to the press-fitting fitting portion 35. On the outer peripheral surface side of the press-fitting fitting portion 35 (male), there are provided projections 35a which are not spaced apart in the circumferential direction and are long in the axial direction at three locations. It can also be set as the structure which provided the concave groove 25a concave on the outer peripheral surface side in the position corresponding to the protrusion 35a of the joint part 35. The circumscribed circle diameter R2 of the protrusion 35a of the press-fitting fitting portion 35 is set to be slightly larger than the maximum inner diameter R1 of the concave groove 25a of the column 25 (R1 <R2). Even in this configuration, the same effect as in the above embodiment can be expected.

[Third embodiment (4)]
FIG. 14 is a front view (a) in a gear box axial direction of a reduction gear for a steering electric power assist mechanism of a steering column press-fitting structure (a column is a female and a projection is a male side) showing a third embodiment (4). FIG. 3 is a side sectional view (b) and a column sectional view (c).

  In the third embodiment (3), the protrusion 35a is provided on the press-fitting fitting portion 35 (male) side. However, the present invention is not limited to this, and as shown in FIG. Protrusions 26a protruding on the peripheral surface side may be provided, and the groove 36a may be provided on the press-fitting fitting portion 36 side at a position corresponding to the protrusions 26a. The minimum outer diameter R2 of the concave groove 36a of the press-fitting fitting portion 36 is set to be slightly larger than the inscribed circle diameter R1 of the protrusion 26a of the column 26 (R1 <R2). Even in this configuration, the same effect as in the above embodiment can be expected.

  In the third embodiment (1), (2), (3), (4), the protrusion and the groove are all press-fitted. However, the present invention is not limited to this, and the protrusion and the groove are only positioned. The cylindrical surfaces of the other portions can also be clamped by press fitting. In this case, it is preferable to perform clearance fitting so that only the press-fitting fitting portion and both tip portions (biting portions) of the column are easily inserted.

  All of the embodiments described above are for electric power steering without a tilt mechanism that can adjust the position of the handle up and down, but the present invention can also be applied to an electric power steering mechanism with a tilt mechanism.

Gearbox axial front view (a), side sectional view (b), and column sectional view (c) of a steering column press-fitting structure (when the column is male) showing the first embodiment (1) of the present invention It is. Gearbox axial front view (a), side sectional view (b), and column sectional view (c) of the steering column press-fitting structure (when the column is a knife) showing the first embodiment (2) of the present invention It is. Gear box axial front view (a), side cross-sectional view (b), and column cross-section of steering column press-fitting structure (column is male and projection is female side) showing the second embodiment (1) of the present invention It is a figure (c). Gear box axial front view (a), side sectional view (b) of a press-fitting structure of a steering column (column is male and projection is female side) showing a modification of the second embodiment (1) of the present invention, It is a column sectional view (c). Gearbox axial front view (a), side sectional view (b), and column cross-section of a steering column press-fitting structure (column is male and projection is male side) showing the second embodiment (2) of the present invention It is a figure (c). Gearbox axial front view (a), side cross-sectional view (b) of a steering column press-fitting structure (column is male, projection is male side) showing a modification of the second embodiment (2) of the present invention, It is a column sectional view (c). Gearbox axial front view (a), side sectional view (b), and column cross-section of a steering column press-fitting structure (column is a knife and projection is a female side) showing a second embodiment (3) of the present invention It is a figure (c). Gearbox axial front view (a), side cross-sectional view (b) of a press-fitting structure of a steering column (column is a knife, projection is a knife side) showing a modification of the second embodiment (3) of the present invention, It is a column sectional view (c). Gearbox axial front view (a), side cross-sectional view (b), and column cross-section of steering column press-fitting structure (column is female and projection is male side) showing the second embodiment (4) of the present invention It is a figure (c). Gear box axial front view (a), side cross-sectional view (b) of a steering column press-fitting structure (column is a female, projection is a male side) showing a modification of the second embodiment (4) of the present invention, It is a column sectional view (c). Steering column press-fitting structure (column is male and projection is female side) showing a third embodiment (1) of the present invention (a) in a gear box axial direction front view, a side sectional view (b), and a column It is an expanded sectional view (c). Gearbox axial front view (a), side cross-sectional view (b), and column cross-section of a steering column press-fitting structure (column is male and projection is male side) showing the third embodiment (2) of the present invention It is a figure (c). Gear box axial front view (a), side sectional view (b), and column of the press-fitting structure of a steering column (column is a knife and projection is a knife side) showing a third embodiment (3) of the present invention. It is an expanded sectional view (c). Gearbox axial front view (a), side cross-sectional view (b), and column cross-section of steering column press-fitting structure (column is female and projection is male side) showing the third embodiment (4) of the present invention It is a figure (c). It is a side view which shows the steering column structure incorporating the embodiment (when a column is a male) of this invention. FIG. 5 is a side sectional view (a), a gear box axial front view (b), and a column sectional view (c) showing a conventional steering column press-fitting structure (when the column is male).

Explanation of symbols

1: Gearbox
2, 20 etc .: Columns 3, 30 etc .: Press-fit fitting portions 31a, 21a etc .: projection
23a, 34a, etc .: concave groove

Claims (7)

In the press-fitting structure of the steering column in which the tip end portion of the column holding the steering shaft is press-fitted / internally fitted or externally fitted to the press-fitting fitting portion provided in the gear box,
At least one of the press-fitting fitting portion or the column has a cylindrical shape with an irregular cross section, and is joined by partial contact. 2. The press-fitting structure for a steering column according to claim 1, wherein one of the press-fitting fitting part or the column has a polygonal cross-sectional shape, and the other of the press-fitting fitting part or the column has a cylindrical shape. The one of the press-fitting fitting part or the column has a shape in which a plurality of projections long in the axial direction are provided in the circumferential direction, and the other of the press-fitting fitting part or the column has a cylindrical shape. 1 is a press-fitting structure of a steering column. One of the press-fitting fitting part or the column has a shape in which a plurality of axially long protrusions are provided in the circumferential direction, and the other one of the press-fitting fitting part or the column is arranged in correspondence with these protrusions. 2. The press-fitting structure for a steering column according to claim 1, wherein the fitting is a cylindrical shape provided with a recessed groove in the circumferential direction. 5. The steering column press-fitting structure according to claim 3, wherein the plurality of axially long projections provided in the circumferential direction of the cylindrical shape are arranged at unequal intervals in the circumferential direction. 6. The plurality of axially long protrusions provided at unequal intervals in the one circumferential direction are arranged such that the rigidity of the steering column against bending is higher in the tilt adjustment direction than in the left-right direction. 6. A press-fitting structure for a steering column according to claim 5. The plurality of axially long projections provided at unequal intervals in the one circumferential direction are arranged such that the phase in the rotational direction around the axis coincides with the other concave groove only at one location. 6. The press-fitting structure for a steering column according to claim 4 or 5, wherein

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