JP2983130B2 - Impact absorbing steering column and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shock-absorbing steering column used for absorbing a shock acting on a driver in the event of a vehicle collision, and a method of manufacturing the same.

[0002]

2. Description of the Related Art An impact-absorbing steering column is provided in which a cylindrical second column is press-fitted into a cylindrical first column via a cylindrical spacer, and the impact energy is absorbed by an axial relative movement of both columns. It has been proposed.
172965). The spacers prevent the columns from being squeezed from each other, and absorb the impact energy by smooth relative movement of the columns in the axial direction.

[0003]

In the shock absorbing steering column having the above structure, if the press-fit load of the first column through the spacer of the second column becomes excessive, the smooth relative movement of both columns in the axial direction is hindered. However, if the press-fitting load becomes too small, the impact energy cannot be sufficiently absorbed, and in any case, a large impact force acts on the driver. Therefore, it is necessary to set the press-fitting load in an appropriate range.

Therefore, it is conceivable to set the press-fitting load within an appropriate range by controlling the interference between the two columns and the spacer. However, since the inner diameter of the first column, the outer diameter of the second column, and the thickness of the spacer in the radial direction have large molding errors and require a certain or more dimensional tolerance,
It is difficult to set the press-fitting load within a desired range based on such management of the interference.

An object of the present invention is to provide a shock absorbing steering column and a method of manufacturing the same that can solve the above-mentioned problems of the prior art.

[0006]

Means for Solving the Problems] present first invention, possess a cylindrical first column and a second column cylindrical press-fitted over the cylindrical spacer in the first column, the press-fitting On the occasion of
The magnitude of the press-fit load is determined by the outer peripheral surface of the spacer and the first
The amount of friction between the inner peripheral surface of the column and the spacer
Less friction between the peripheral surface and the outer peripheral surface of the second column
In the shock absorbing type steering column corresponding to at least one of the outer periphery of the spacer, the inner periphery of the first column contacting the outer periphery of the spacer, the inner periphery of the spacer, and the outer periphery of the second column contacting the inner periphery of the spacer. A recess is formed in at least one part, and the spacer is
It is characterized by being formed by coating a resin .

The second invention has a step of press-fitting the cylindrical second column into the cylindrical first column via a cylindrical spacer.
However, the magnitude of the press-fit load in this press-fitting process is
Between the outer peripheral surface of the spacer and the inner peripheral surface of the first column
Size and the inner peripheral surface of the spacer and the outer peripheral surface of the second column
In the method for manufacturing the friction magnitude of the impact absorbing type steering column corresponding to at least one between, on at least one of the plurality of spacers each inner periphery, they double
The number of spacers form a recess so that the contact areas with at least one of the two columns are different from each other,
One spacer interposed between the two columns is selected from a spacer group including the plurality of spacers in accordance with a press-fit load in the press- fitting step set in advance.

[0008]

The magnitude of the press-fit load when the second column is press-fitted into the first column via the spacer depends on the magnitude of the friction between the outer peripheral surface of the spacer and the inner peripheral surface of the first column and the size of the spacer. It corresponds to at least one of the magnitudes of friction between the inner peripheral surface and the outer peripheral surface of the second column. The magnitude of the friction is the first
It corresponds to the contact area of the inner and outer peripheral surfaces of the spacer with the inner peripheral surface of the column and the outer peripheral surface of the second column. The contact area can be arbitrarily set according to the axial dimension of the spacer. However, if the axial dimension of the spacer is short, the impact columns that intersect in the axial direction of both columns will cause the two columns to be crushed. On the other hand, according to the configuration of the shock absorbing steering column of the present invention, the outer periphery of the spacer, the inner periphery of the first column that contacts the outer periphery of the spacer, the inner periphery of the spacer, and the second column that contacts the inner periphery of the spacer Since the concave portion is formed at least at a part of the outer periphery of the spacer, the inner and outer peripheral surfaces of the spacer with respect to the inner peripheral surface of the first column and the outer peripheral surface of the second column can be reduced without reducing the axial dimension of the spacer. The contact area can be set arbitrarily, and the press-fitting load can be set in a desired range without causing the columns to twist each other.

The contact area of the inner and outer peripheral surfaces of the spacer with the inner and outer peripheral surfaces of the first column and the second column is arbitrarily determined according to the area of the recess formed in at least one of the inner and outer peripheral surfaces of the spacer. Can be set. Therefore, a recess is formed on at least one of the inner and outer peripheral surfaces of the plurality of spacers so that contact areas with at least one of the two columns are different from each other, and one spacer interposed between the two columns from the spacer group including the plurality of spacers. By selecting the spacer, it is possible to set the press-fitting load within a desired range.

[0010]

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

The shock absorbing steering column 1 shown in FIGS. 1, 5 and 6 has a cylindrical first metal column 2a and a metal metal press-fitted into the first column 2a via a cylindrical spacer 3. A second column 2b is provided, and the relative movement in the axial direction between the first column 2a and the second column 2b is restricted unless a force exceeding a certain value corresponding to the press-fit load acts.

The first column 2 a supports a first cylindrical handle shaft 5 via a bearing 4. This first
A handle (not shown) is connected to one end of the handle shaft 5, and one end of the second handle shaft 7 is inserted into the other end so as to be relatively movable in the axial direction and not to rotate relatively. The bearing 4 has a step 2 formed on the inner periphery of the first column 2a.
a ′ and the retaining ring 12 attached to the outer periphery of the first handle shaft 5 prevent the first column 2 a and the first handle shaft 5 from moving in the axial direction.

A pair of circumferential grooves 8 are formed on the outer periphery of the second handle shaft 7, and a through hole 9 communicating with the circumferential groove 8 is formed in the first handle shaft 5, and the through hole 9 and the circumferential groove 8 are formed.
Then, the resin 60 is filled. As a result, relative axial movement between the first handle shaft 5 and the second handle shaft 7 is restricted unless a certain force or more acts. By making the inner peripheral shape of the first handle shaft 5 and the outer peripheral shape of the second handle shaft 7 non-circular, the relative rotation of the handle shafts 5 and 7 is restricted. The rotation of the steering wheel is transmitted to the steering wheel by connecting the steering wheel to the second handle shaft 7 via, for example, a rack and pinion type steering gear.

An upper bracket 11 is welded to the first column 2a. The upper bracket 11
Is a pair of side walls 11a, 11b and respective side walls 11a, 11b.
b, connecting walls 11c connecting one end of
Support portions 11d and 11e extend radially outward of the first column 2a from the other end of 1b. Each support 11d, 1
1e has notches 11d ', 1
1e 'is formed, and aluminum connecting members 20, 21 are inserted into the notches 11d', 11e '. That is, a pair of grooves 20a ', 20b', 21a ', 21b' is formed in each connecting member 20, 21 along the column axis direction, and the supporting portions 11d are formed in the grooves 20a ', 20b', 21a ', 21b'. , 11e are inserted along the periphery of the notches 11d ', 11e' so as to be relatively movable along the column axis direction. Notch 11 of supporting portions 11d and 11e
A plurality of through-holes are formed at portions along the periphery of d 'and 11e'. Through-holes communicating with the through-holes are formed in the connecting members 20 and 21, and both through-holes are filled with the resin 61. As a result, the axial relative movement between the upper bracket 11 and the connecting members 20 and 21 is restricted unless a certain force or more acts.

As shown in FIG. 7, a pair of screw shafts 40 implanted in the vehicle body side member 45 are inserted into bolt through holes 35 of the connecting members 20 and 21, and a nut 41 screwed to the screw shaft 40. Connecting members 20, 2
The connection members 20 and 21 are fixed to the vehicle body by the insertion of 1. The bolt holes 35 are elongated in the column axis direction in the longitudinal direction, and are capable of coping with misalignment between members due to manufacturing errors.

[0016] As shown in FIG. 2, the spacer 3 has a flange 3 'at one end with a cylindrical, or are elastically deformable in the radial direction by having a split groove 25 along the axial direction, for example, formed by quotes fin grayed Teflon resin on a metal mesh. When press-fitting the second column 2b into the first column 2a via the spacer 3, first,
The spacer 3 is inserted into the inner periphery of the first column 2a such that the flange 3 'at one end is in contact with the end surface of the first column 2a,
Thereafter, the second column 2b is pressed into the inner periphery of the spacer 3.

At the time of press-fitting, one spacer to be interposed between the two columns 1a and 2b is selected from a spacer group according to a press-fitting load set in advance. The spacer group is
It includes a plurality of spacers 3a, 3b, 3c, and 3d in a developed shape as shown in (1) to (4) of FIG. Each spacer 3
a, 3b, 3c, and 3d have the same axial dimension, inner and outer diameter dimensions, and the same material, and are different from each other in that the spacer 3a shown in (1) of FIG. The spacer 3b shown in FIG. 3 has three long holes 30 penetrating the inner and outer peripheries at the end opposite to the flange 3 ', thereby forming three concave portions on the inner and outer peripheries, respectively. The spacer 3c shown in FIG. 3) has four long holes 30 penetrating the inner and outer peripheries at the end opposite to the flange 3 'so that four concave portions are formed on the inner and outer peripheries. The spacer 3d shown in FIG.
This means that five concave portions are formed on the inner and outer peripheries by being biased toward the opposite end. Also, (2) of FIG.
The areas of the long holes 30 shown in (4) are equal to each other. Thereby, the contact areas between the spacers 3a, 3b, 3c, 3d and the columns 2a, 2b shown in (1) to (4) of FIG. 3 are different from each other.

The magnitude of the press-fitting load when the second column 2b is press-fitted into the spacer 3 inserted into the inner circumference of the first column 2a depends on the inner peripheral surface of the spacer 3 and the outer peripheral surface of the second column 2b. It corresponds to the magnitude of the friction between them. The magnitude of the friction corresponds to the contact area between the inner peripheral surface of the spacer 3 and the inner peripheral surface of the first column 2a and the outer peripheral surface of the second column 2b. The contact area can be arbitrarily set according to the area of the concave portion formed on the inner and outer periphery of the spacer 3 by the through hole 30. That is, as shown in FIG. 4A, the contact area is proportional to the press-fit load, and as shown in FIG.
The contact area is maximum at the end point E of the press-fitting stroke of the second column 2b into the spacer 3 as shown by the solid line in FIG. 3 (1), and then as shown in FIG. 3 (2). The spacer 3b is large as shown by the broken line,
Next, the spacer 3c shown in FIG. 3 (3) is large as shown by the dashed line, and the spacer 3d shown in FIG. 3 (4) is the smallest as shown by the dashed line. Therefore, (3) in FIG.
As shown in FIG. 3, at the end point E of the press-fitting stroke of the second column 2b into the spacer 3, the spacer 3a shown in (1) of FIG.
Next, the spacer 3b shown in FIG. 3 (2) is large as shown by the broken line, the spacer 3c shown in FIG. 3 (3) is large as shown by the dashed line, and the spacer 3d shown in FIG. It is the smallest as shown by the two-dot chain line. Thus, the first through the spacers 3 selected from the spacer group.
When the second column 2b is press-fitted into the column 2a, the press-fit load is measured, and when the measured value is out of a range based on a preset value, a different spacer 3 is selected from the spacer group and the press-fit load is selected. Can be set within a desired range. The number of types of spacers 3 having different contact areas with the columns 2a and 2b and the specific value of the contact area are not particularly limited, and may be appropriately determined according to the press-fit load to be set.

According to the above construction, the impact force along the column axis acts at the time of a vehicle collision, so that the resin 60, 6
1 is sheared to absorb the impact energy, and the two columns 2a and 2b move relative to each other in the axial direction to absorb the impact energy corresponding to the press-fit load of the two columns 2a and 2b. At this time, by setting the press-fitting load within an appropriate range, a large impact force can be prevented from acting on the driver.
In addition, without reducing the axial dimension of the spacer 3, the first
The contact area of the spacer 3 with the inner peripheral surface of the column 2a and the outer peripheral surface of the second column 2b can be reduced.
Of the two columns 2a, 2b can be made large enough to prevent the two columns 2a, 2b from squeezing each other.
Even if an impact force intersecting in the axial direction is applied, the two columns 2a and 2b can smoothly move relative to each other in the axial direction and absorb the impact energy.

The present invention is not limited to the above embodiment. For example, in the above-described embodiment, the concave portions are formed on the inner and outer circumferences of the spacer 3 by the long holes 30, but (2) to (4) in FIG.
As shown in the figure, a predetermined press-fitting is performed from a spacer group 3a, 3b ', 3c', 3d 'including spacers 3b', 3c ', 3d' having recesses formed on the inner and outer circumferences of the spacer 3 by the circular through holes 30 '. One spacer interposed between the columns 1a and 2b may be selected according to the load. At this time,
The relationship diagram corresponding to FIG. 4 in the embodiment of FIG. 8 is as shown in FIG. 9, and the bending point of the press-fit load can be shifted or the inclination can be changed. Further, a concave portion may be formed on the inner and outer periphery of the spacer 3 by a square hole. Further, a concave portion may be formed in only one of the inner circumference and the outer circumference of the spacer 3 by the bottomed hole. In addition, as shown in FIG.
A recess is formed on the outer periphery of the first column 2b by a through hole 71, a recess is formed on the outer periphery of the second column 2b by a bottomed hole, and a recess is formed on the inner periphery of the first column 2a by a through hole or a bottomed hole. The recess may be formed in at least a part of the outer periphery of the spacer, the inner periphery of the first column in contact with the outer periphery of the spacer, the inner periphery of the spacer, and the outer periphery of the second column in contact with the inner periphery of the spacer. I just need. The flange 3 'of the spacer 3 is not essential, and the impact energy may be absorbed by friction between the outer peripheral surface of the spacer 3 and the inner peripheral surface of the first column 2a. Further, in the above-described embodiment, the spacer group includes the one in which the recess is not formed on the inner and outer circumferences of the spacer, but the spacer group may not be included.

In FIG. 10, the recess formed in the outer periphery of the second column 2b by the through hole 71 is subjected to an impact as shown in FIGS.
The contact area between the inner peripheral surface of the spacer 3 and the outer peripheral surface of the second column 2b when the first and second columns 2a and 2b are moved relative to each other in the axial direction, as shown in FIG. As compared with before the movement, the relative movement stroke increases as the relative movement stroke increases (in FIG. 10, a triangle in plan view). As a result, the load generated due to the friction between the inner peripheral surface of the spacer 3 and the outer peripheral surface of the second column 2b at the time of the impact is initially small and gradually increased. The initial peak load acting on the driver can be reduced in combination with the shearing of 61, and thereafter, the impact column can be prevented from hitting the vehicle body by sufficiently absorbing the impact energy. The recess having such an effect is provided at least at a part of the outer periphery of the spacer, the inner periphery of the first column in contact with the outer periphery of the spacer, the inner periphery of the spacer, and the outer periphery of the second column in contact with the inner periphery of the spacer. Can be formed.

[0022]

According to the present invention, when the second column is press-fitted into the first column via the spacer, the press-fitting load is set in an appropriate range to prevent a large impact force from acting on the driver. it can.

[Brief description of the drawings]

FIG. 1 is a sectional view of a steering column according to an embodiment of the present invention.

FIG. 2 is a perspective view of a spacer according to the embodiment of the present invention.

FIGS. 3 (1) to (4) are development views of a spacer according to an embodiment of the present invention in which contact areas with first and second columns are different from each other.

4A is a diagram showing the relationship between the contact area between the spacer and the column and the press-fit load, FIG. 4B is a diagram showing the relationship between the press-fit stroke between the spacer and the column and the contact area, and FIG. 4B is a diagram showing the relationship between the spacer and the column. Between press-fit stroke and press-fit load

FIG. 5 is a plan view of the steering column according to the embodiment of the present invention.

FIG. 6 is a sectional view taken along line VI-VI of FIG. 5;

FIG. 7 is a sectional view taken along line VII-VII of FIG. 1;

8 (1) to 8 (4) are development views of a spacer according to a modified example of the present invention in which contact areas with the first and second columns are different from each other.

9 is a diagram corresponding to FIG. 4 corresponding to FIG. 8, wherein (1) is a diagram showing the relationship between the contact area between the spacer and the column and the press-fit load,
(2) is a diagram showing the relationship between the press-fit stroke of the spacer and the column and the contact area, and (3) is a diagram showing the relationship between the press-fit stroke of the spacer and the column and the press-fit load.

FIGS. 10A to 10C are cross-sectional views of first and second columns and a spacer according to a modification of the present invention.

[Explanation of symbols]

 2a first column 2b second column 3 spacer 30 through hole

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-18563 (JP, A) JP-A 1-172965 (JP, U) JP-A 55-104576 (JP, U) JP-A 53-185 29029 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) B62D 1/04-1/20

Claims (2)

(57) [Claims] [1 claim: a tubular first column, the size of this first column have a cylindrical second column is press fitted through a cylindrical spacer, press-fit load of when the press-fitting, the S
Large friction between the outer surface of the pacer and the inner surface of the first column
Between the inner surface of the spacer and the outer surface of the second column
The outer periphery of the spacer, the inner periphery of the first column that contacts the outer periphery of the spacer, the inner periphery of the spacer, and the second column that contacts the inner periphery of the spacer. a recess in at least one site of the outer periphery of forming, the spacer
Is to coat the metal mesh with Teflon resin
A shock-absorbing steering column, characterized by being formed of: Wherein the tubular second column in a cylindrical first column have a step of press-fitting through the cylindrical spacer, to the press fit
The size of the press-fit load during the process
The magnitude and friction of the friction between the peripheral surface and the inner peripheral surface of the first column
Large friction between the inner peripheral surface of the pacer and the outer peripheral surface of the second column
In come of the manufacturing method of the impact absorbing type steering column corresponding to at least one of the, at least one of the inner periphery of each of the plurality of spacers <br/>, the plurality of spacers <br/> said at least one of the two column bets of such contact area is mutually different, a recess, the spacer group including the plurality of spacers, said press-fit preset
A method of manufacturing an impact-absorbing steering column, wherein one spacer interposed between both columns is selected according to a press-fit load in a process.