JP2014040207A5 - - Google Patents

Description

Steering column and manufacturing method thereof

  The present invention relates to an improvement in a steering column constituting a steering apparatus for an automobile and a manufacturing method thereof. Specifically, it is intended to achieve both the thinning of the steering column and the securing of strength.

  For example, a structure as shown in FIG. 6 is widely known as a steering device for giving a steering angle to a steered wheel (usually a front wheel except a special vehicle such as a forklift). In this steering device, a steering shaft 3 is rotatably supported on the inner diameter side of a cylindrical steering column 2 supported by a vehicle body 1. A steering wheel 4 is fixed to the rear end portion of the steering shaft 3 protruding rearward from the rear end opening of the steering column 2. When the steering wheel 4 is rotated, this rotation is transmitted to the input shaft 8 of the steering gear unit 7 via the steering shaft 3, the universal joint 5a, the intermediate shaft 6, and the universal joint 5b. When the input shaft 8 rotates, a pair of tie rods 9, 9 arranged on both sides of the steering gear unit 7 are pushed and pulled, and a steering wheel according to the operation amount of the steering wheel 4 is turned to a pair of left and right steering wheels. Give a corner. In the case of the structure shown in FIG. 6, telescopic type is used as the steering column 2 and the steering shaft 3 in order to enable adjustment of the front-rear position of the steering wheel 4.

  The steering column 2 and the steering shaft 3 are configured to displace the steering wheel 4 while absorbing impact energy in the event of a collision. That is, in the event of a collision accident, a secondary collision in which the driver's body collides with the steering wheel 4 occurs following a primary collision in which the automobile collides with another automobile or the like. In order to alleviate the impact applied to the driver's body during the secondary collision and to protect the driver, the steering shaft 3 supporting the steering wheel 4 is subjected to the secondary collision with respect to the vehicle body 1. It is necessary to support it so that it can be displaced forward by a forward impact load. For this reason, the steering column 2 is contracted by the impact load of the secondary collision, the outer column 10 is shortened by the entire length of the steering column 2, and the steering shaft 3 is contracted by the outer tube 11 by the total length of the steering shaft 3. However, a large impact is prevented from being applied to the driver's body colliding with the steering wheel 4 by being displaced forward.

  On the other hand, in recent years, theft of automobiles is increasing, and various antitheft devices are provided in automobiles. As one type, a steering lock device that disables the operation of the steering wheel unless a regular key is used is widely implemented. FIG. 7 shows an example of the steering lock device described in Patent Document 1. The steering lock device 12 is provided with a lock unit 13 at a part of the steering column 2a, and at a part of the steering shaft 3a at a position where the phase in the axial direction coincides with the lock unit 13 at at least one place in the circumferential direction. A key lock collar 15 formed with an engagement recess 14 is fixed by external fitting. During operation (at the time of key lock), the tip of the lock pin 16 constituting the lock unit 13 is passed through the lock through hole 17 formed in the intermediate portion in the axial direction of the steering column 2a. By displacing toward the inner diameter side and engaging with the engaging recess 14, rotation of the steering shaft 3a is substantially disabled.

  When the steering lock device 12 as described above is incorporated in a steering device, the lock unit 13 is provided on the outer diameter side of the steering column 2a, and the key lock collar 15 is provided on the inner diameter side of the steering column 2a. . Therefore, the key lock collar 15 is rotatably arranged on the inner diameter side of the steering column 2a, and the lock pin 16 and the key lock collar 15 are securely connected without excessively increasing the stroke of the lock pin 16. In order to engage / disengage, at least a portion of the steering device incorporating the steering lock device 12 has a small outer diameter and a larger inner diameter (the thickness of the steering column 2a is reduced). There is.

  FIG. 8 shows an outer column 10a described in Patent Document 2 that constitutes a steering column. In the outer column 10a, the end portion of the cylindrical inner column is fitted into the end portion in the axial direction (left end portion in FIG. 8) so as to be relatively displaceable in the axial direction. The outer column 10a is made of a light alloy such as an aluminum alloy or a magnesium alloy, and is integrally formed by casting. The outer column 10a is a lock for incorporating a steering lock device 12 (see FIG. 7) in an intermediate portion in the axial direction. A through hole 17a is provided. When the thickness of the outer column 10a of such a steering column is reduced, there is a possibility that sufficient strength of the outer column 10a required in a state where the steering lock device 12 is operated cannot be secured. That is, in a state where the lock pin 16 protruded to the inner diameter side of the outer column 10a through the lock through hole 17a is engaged with the engagement recess 14 (see FIG. 7) of the key lock collar 15, the steering wheel 4 is moved. When attempting to rotate with a large force, an excessively large force is applied to the peripheral portion of the locking through hole 17a, and this peripheral portion may be deformed. On the other hand, it is conceivable to form the outer column 10a from an iron-based material, but this causes problems such as an increase in the weight of the entire steering column.

JP 2008-265646 A JP 2007-223383 A

In view of the circumstances as described above, the present invention is to realize a steering column and a method for manufacturing the same that can ensure the strength of the steering column while reducing the thickness of a part of the hollow cylindrical steering column. It is a thing.

Among the steering column and the manufacturing method thereof according to the present invention, the steering column according to claim 1 is entirely hollow and cylindrical , and includes a cylindrical inner column and a cylindrical column member. A telescopic mechanism is provided on the inner side of the member. The telescopic mechanism is configured by fitting the inner column in an axially displaceable state.
Further, the column members constituting the steering column, the light alloy of the body portion such as an aluminum alloy or magnesium alloy, and a cylindrical member made of iron-based material such as carbon steel and other iron-based alloys I have.
Of these, the cylindrical member is axially coupled to the main body portion by fitting and fixing the other side end portion to one end portion of the main body portion. In addition, the cylindrical member is provided with a locking through-hole that constitutes a steering lock device in a part of the axial direction thereof, and by swaging the other side end surface, the other side edge The inner diameter of the portion is smaller than the inner diameter of the portion of the other side end portion that is axially removed from the other end edge portion, and the outer diameter of the other end edge portion is the other side end portion. It is larger than the outer diameter of the portion of the end portion that is axially removed from the other end edge portion.
Further, in the case of the steering column of the present invention, one or more convex portions are provided on the inner peripheral surface of the one end portion of the main body portion, and the outer peripheral surface of the other end portion of the cylindrical member is provided. One or a plurality of concave portions that engage with the convex portions are provided.

When implementing the steering column of the present invention as described above, preferably, as in the invention described in claim 2, the inner diameters of the other end portion of the cylindrical member and the one end portion of the main body portion are set as follows : It is more than the internal diameter of the part which remove | deviated from the coupling | bond part with this cylindrical member among this main body part to an axial direction.

When implementing the steering column of the present invention, the inner diameter of the other end face (the other end edge) of the cylindrical member is set to the inner diameter of the one end face of the main body portion of the cylindrical member. It should be smaller than the inner diameter of the portion located on the side. After the main body portion and the cylindrical member are coupled in the axial direction, at least the inner diameter side portion of the other end edge portion of the cylindrical member is subjected to a cutting process, and the second end portion of the cylindrical member is closer to the other end portion. the inner diameter of a portion, and more inner diameter of the body portion. By adopting such a configuration, it is possible to make the inner diameter dimension of the portion near the other end of the cylindrical member out of the column members constituting the steering column equal to or smaller than the inner diameter dimension of the main body portion. Moreover, since the portion located on the inner diameter side of the one end face of the main body portion is not cut out of the inner diameter side portion of the thin cylindrical member, the coupling strength between the main body portion and the cylindrical member and It can prevent that the torsional strength and bending strength of this cylindrical member decline.

Although outside the technical scope of the steering column of the present invention, 1 to convex portion provided at a plurality of locations of the other side end portion outer peripheral surface, one side end portion inner peripheral surface of the body portion of the cylindrical member The main body portion and the cylindrical member can be coupled in the axial direction by engaging with concave portions provided at one or a plurality of locations.

According to a third aspect of the present invention, there is provided a steering column manufacturing method comprising: a hollow cylindrical shape as a whole; and at least a part of a column member comprising a light alloy main body portion, a ferrous material cylindrical member; The cylindrical member is connected to the main body portion in the axial direction by internally fitting and fixing the other side end portion to the one side end portion of the main body portion, An inner diameter of the other side edge is smaller than an inner diameter of a portion of the other side edge that is axially removed from the other side edge, and an outer diameter of the other side edge is This is a method for manufacturing a steering column that is larger than the outer diameter of a portion of the other side end portion that is axially deviated from the other side edge portion.
In particular, in the method for manufacturing a steering column according to claim 3, after forming a recess in the outer peripheral surface of the other end portion of the cylindrical member, the other end portion of the cylindrical member is attached to a mold. The insertion is made through an insertion hole that opens at one end, and the other end of the cylindrical member is projected into the mold. Next, the one end of the core is inserted into the other end of the cylindrical member. Thereafter, the molten metal is fed into the mold to mold the main body portion, and a part of the molten metal is allowed to enter the concave portion to form a convex portion on the inner peripheral surface of one end portion of the main body portion. Thus, there is provided a step of connecting the one end portion of the main body portion and the other end portion of the cylindrical member in the axial direction and the circumferential direction to obtain the column member.

Preferably, when the method for manufacturing a steering column according to claim 3 as described above is carried out, as in the invention according to claim 4 , the shaft portion is connected to the cylindrical member from the coupling portion with the cylindrical member. The main body portion is formed such that the inner diameter of the other end edge portion of the cylindrical member is smaller than the inner diameter of the portion deviated in the direction. Thereafter, the other end edge portion of the cylindrical member is subjected to cutting, and the inner diameter of the portion subjected to the cutting is set to a portion of the main body portion that is axially removed from the coupling portion with the cylindrical member. The method further includes a step of setting the inner diameter or more.

Preferably, as in the invention described in claim 5, before the other end portion of the cylindrical member is inserted into the insertion hole of the mold, it is swallowed to the other end surface of the cylindrical member. Apply. And the inside diameter of the other side edge of this cylindrical member is made smaller than the inside diameter of the portion of the other side edge that is axially removed from this other side edge, and the other side edge The method further includes a step of making the outer diameter of the portion larger than the outer diameter of the portion of the other side end portion that is axially deviated from the other end edge portion.

Further, when carrying out the method for manufacturing a steering column of the present invention, for example, in a state where the inner diameter dimension of the other end surface of the cylindrical member is smaller than the inner diameter dimension of the axial intermediate portion of the cylindrical member, The other end portion of the cylindrical member is inserted into an insertion hole provided on one end surface of the mold. And, in a state where one end of the core is inserted into the end of the cylindrical member, and the stepped portion provided in the axial intermediate portion of the core is abutted against the other end surface of the cylindrical member, The melted light alloy can be fed into the mold to form the main body portion. In this case, the inner diameter dimension of the other end face of the cylindrical member is further set to be larger than the inner diameter dimension of the cylindrical member located on the inner diameter side of the portion forming the one end face of the main body portion. Make it smaller. Then, after feeding the light alloy melt into the mold and forming the main body portion, at least the inner diameter side portion of the other end edge portion of the cylindrical member is subjected to cutting, and the other end of the cylindrical member is The inner diameter of the portion near the side end can be made equal to or larger than the inner diameter of the main body.

Furthermore, when carrying out the production method of the steering column of the present invention, provided with an axial groove and the outer flange at a plurality of locations on the other side end portion outer peripheral surface of the cylindrical member, the other side end portion inner peripheral surface Has an inner flange. Here, the outer flange and the inner flange are formed by upsetting of the end portion of the cylindrical member. Then, the time of feeding the molten metal into the mold, a portion of the molten metal, by which enter into the axial groove is the recess forming a convex portion on one side end portion inner peripheral surface of the body portion.

According to the steering column of the present invention configured as described above, the strength of the steering column can be ensured while reducing the thickness of a part of the steering column.
That is, the half of the column member constituting the steering column is formed of a cylindrical member made of an iron-based material. Therefore, even if the thickness of the half is reduced, Strength can be secured. On the other hand, since the other half of the column member is composed of a light alloy main body such as an aluminum alloy or a magnesium alloy, the weight of the entire steering column is excessively increased. Absent.
In the case of the present invention, since the convex portion formed on the inner peripheral surface of the main body portion and the concave portion formed on the outer peripheral surface of the cylindrical member are engaged, the main body portion and the cylindrical member are It is possible to improve the coupling strength in the axial direction and the circumferential direction.

Further , according to the method for manufacturing a steering column of the present invention, the steering column of the present invention as described above can be manufactured industrially efficiently.

The fragmentary sectional view which shows the manufacturing method of the member for columns of a steering column which shows embodiment of this invention in order of a process. Similarly, sectional drawing (A) which shows the state which took out only the cylindrical member and provided the axial direction groove | channel of several places in the front-end part outer periphery. Cross-sectional view (B) showing a state where an outer flange is provided on the outer periphery of the front end and an inner flange is provided on the inner periphery of the front end. Figure (D). Sectional drawing for demonstrating the problem when not implementing the manufacturing method of this invention. The side view which shows an example of the steering device which assembled | attached the member for columns which concerns on this invention. Similarly, the top view seen from the upper part of FIG. The side view which shows one example of the steering device conventionally known in the state which cut | disconnected a part. 1 is a schematic cross-sectional view showing an example of a conventional structure of a steering lock device. The side view which shows one example of the conventional structure of the steering column which provided the through-hole for a lock | rock.

[ Example of Embodiment]
1 and 2 show an example of an embodiment of the present invention . Incidentally, including the present example, the steering column and the manufacturing method thereof according to the present invention are characterized by the thickness of the rear end portion (right side in FIG. 1) of the outer column 10b that is a column member constituting the steering column. It is in the point of realizing a structure capable of ensuring the strength even when it is thinned and a manufacturing method thereof. Since the structure and operation of the other parts are the same as those of a conventionally known steering column including the structure shown in FIG. 10, the illustration and explanation of the equivalent parts are omitted or simplified. The description will focus on the features of the example.

In the case of this example, the outer column 10b includes a main body portion 18 made of a light alloy such as an aluminum alloy or a magnesium alloy, and a cylindrical member 19 made of an iron material such as carbon steel or other iron alloy. Are combined in the axial direction. That is, (the edge portion in the traveling direction front side in a state assembled with the vehicle body, the left end edge in Fig. 1-2) the front edge of the cylindrical member 19 by providing the inner flange 28b, a of the cylindrical member 19 The inner diameter dimension of the front end surface is a portion of the cylindrical member 19 where the rear end surface of the main body portion 18 (the end surface on the rear side in the traveling direction in the assembled state on the vehicle body, the left end surface in FIG. 1) is formed {described later. During casting, the inner diameter of the portion located on the inner diameter side of the inner end surface (left side surface in FIG. 1) of the mold 21 is made smaller than the inner diameter dimension. Here, in order to prevent rotation of the cylindrical member 19 with respect to the main body portion 18 and prevent rotation, a concave portion or a convex portion is formed on the outer periphery of the front end portion of the cylindrical member 19. Specifically, of the cylindrical member 19, the axial grooves 20 at a plurality of positions of the front end outer peripheral surface, an outer flange 28a at a front edge portion periphery, the inner flange 28b in the circumferential front edge portion, respectively provided. The step, after forming by drawing or rolling the axial grooves 20b of the plurality of locations in the front end outer peripheral surface, and more giving a molded swaging the front end face, each outer flange 28a, an inner front edge portion The flange 28b is formed, and finally the small diameter portion 32 is formed. The upsetting at this time may be by so-called press molding or by so-called spatula drawing by rotation. Since the outer flange 28a and the inner flange 28b are formed by swaging at the same time, the cost is low. Then, as shown in FIG. 1A, the portion near the front end of the cylindrical member 19 is inserted into the insertion hole 23 opened in the end surface 22 of the mold 21, and the portion near the front end is inserted into the mold 21. Protrude in. The one side and the other side described in the claims correspond to the rear side and the front side in the present embodiment, respectively.

And the front-end | tip part 25 of the core 24 is inserted in the front-end part of the said cylindrical member 19, and the level | step difference surface 27 provided between the front-end | tip part 25 of this core 24 and the base end part 26 is made into the said cylindrical member. 19 is abutted against an inner flange 28b provided on the front end face of 19. Here, the inner diameter dimension of the inner flange 28b is made smaller than the inner diameter dimension of the portion of the cylindrical member 19 located on the inner diameter side of the portion where the rear end surface of the main body portion 18 is formed .

Then, a molten metal of a light alloy such as an aluminum alloy or a magnesium alloy is fed into the mold 21 with the stepped surface 27 of the core 24 abutted against the front end surface of the cylindrical member 19. The body portion 18 is formed. At this time, by projecting a part of the molten metal into a plurality of axial grooves 20 formed on the outer peripheral surface of the front end portion of the cylindrical member 19, a convex portion is formed on the inner peripheral surface of the rear end portion of the main body portion 18. 29 is formed. And after taking out from the said metal mold | die 21, it cuts in the inner peripheral edge of the said inner flange 28b which protruded in radial direction rather than the inner peripheral surface of the said main-body part 18 among the said cylindrical members 19. , At least the front end portion of the cylindrical member 19 {formed to fit and fix the outer ring of the rolling bearing 31 (see FIG. 7) for rotatably inserting the inner column 30 to the inner diameter side of the outer column 10b. The inner diameter of the portion excluding the small diameter portion 32 is set to be equal to or larger than the inner diameter of the main body portion 18. At this time, if necessary, cutting is also applied to a portion near the rear end of the inner peripheral surface of the main body portion 18. By such a cutting process, there is no step surface facing forward between the inner peripheral surface of the main body portion 18 inserted through the inner column 30 and the front end edge of the cylindrical member 19, so It is possible to smoothly move the outer column 10b forward at the time of a collision, and to enhance the protection of the driver in the event of a collision. Note that the diameter of the inscribed circle having the apex at the groove bottom of the axial groove 20 on the inner peripheral surface of the front end portion of the cylindrical member 19 is equal to or larger than the inner diameter of the main body portion 18, and the tips of these projections are The main body portion 18 should not protrude inward in the radial direction from the inner peripheral surface.

  In the case of the steering column manufacturing method of the present example configured as described above, of the outer column 10b configuring the steering column, for example, the thickness of the portion near the rear end into which the steering lock device 12 (see FIG. 7) is incorporated. The outer column 10b that can secure the strength while reducing the thickness can be manufactured industrially and efficiently. That is, the portion near the rear end of the outer column 10b is constituted by a cylindrical member 19 made of an iron-based material, which is easy to ensure strength. For this reason, even if a lock through hole 17 is provided in order to reduce the thickness of the portion for attaching the lock unit 13 or the key lock collar 15 or to insert the lock pin 16, the portion closer to the rear end. The strength of the outer column 10b can be ensured.

Further, on the outer peripheral surface of the front end portion of the cylindrical member 19, the engagement area between the cylindrical member 19 and the main body portion 18 is increased by forming the axial groove 20 and the outer flange 28a . . Since the cylindrical member 19 is formed with an outer flange 28a, which is engaged with the rear end portion of the main body portion 18, the axial coupling strength between the main body portion 18 and the cylindrical member 19 is determined. Can be secured more sufficiently. Here, since the outer flange 28a is a means for ensuring the axial coupling strength by increasing the plate thickness of the cylindrical member 19, the outer flange 28a has high rigidity, and there is no fear of breakage at the part, and the reliability is high. Also in the circumferential direction, the axial groove 20 can be used even when the steering wheel 4 is rotated with a large force with the lock pin 16 engaged with the engagement recess 14 of the key lock collar 15. By engaging the projection 29, the torsional rigidity of the joint between the main body portion 18 and the cylindrical member 19 can be increased.

Moreover, subjected to shaping swaging a front end portion of the cylindrical member 19, the inner diameter of the front end surface of the cylindrical member 19, of the cylindrical member 19, the portion which the rear end surface of the body portion 18 is formed The main body portion 18 is formed by casting in a state where it is smaller than the inner diameter dimension of the portion located on the inner diameter side. Therefore, it is possible to effectively ensure the strength of the joint portion between the main body portion 18 and the cylindrical member 19. The inner diameter dimension of the front end surface of the cylindrical member 19 is smaller than the inner diameter dimension of the portion of the cylindrical member 19 located on the inner diameter side of the portion where the rear end surface of the main body portion 18 is formed. The advantage of forming the main body portion 18 will be described with reference to FIG. 3 in addition to FIG. In FIG. 3, the inner diameter dimension of the front end surface of the cylindrical member 19a is made smaller than the inner diameter dimension of the portion of the cylindrical member 19a located on the inner diameter side of the portion where the rear end surface of the main body portion 18a is formed. A method of manufacturing the outer column 10c by connecting the main body portion 18a and the cylindrical member 19a in the axial direction without making the inner diameter dimension of the cylindrical member 19a larger than the inner diameter dimension of the main body portion 18a is shown. ing. As described with reference to FIG. 1 above, in order to prevent the molten metal from leaking when casting with the main body portions 18 and 18a, a mating surface for abutting the stepped surface 27 of the core 24 is required. Become. In the case of the present invention, the inner diameter dimension of the front end face of the cylindrical member 19 which is the mating face is set to the part of the cylindrical member 19 located on the inner diameter side of the part where the rear end face of the main body portion 18 is formed. It is smaller than the inner diameter.

  On the other hand, in the case of the reference example shown in FIG. 3, the inner diameter of the front end surface of the cylindrical member 19a is set to the portion of the cylindrical member 19a where the rear end surface of the main body portion 18a is formed. The inner diameter of the portion located on the inner diameter side is the same. Under such conditions, as shown in FIG. 3A, the inner peripheral surface of the portion near the rear end of the main body portion 18a is engaged with the outer peripheral surface of the portion near the front end of the cylindrical member 19a. The main body portion 18a is molded by casting. Next, in order to make the inner diameter of the cylindrical member 19a equal to or larger than the inner diameter of the main body portion 18a, as shown in FIG. 3 (B), at the connecting portion between the main body portion 18a and the cylindrical member 19a, Cutting is performed on the inner diameter side portion of the front end portion of the cylindrical member 19a. At this time, the inner diameter dimension of the front end surface of the cylindrical member 19a is made smaller than the inner diameter dimension of the portion of the cylindrical member 19a located on the inner diameter side of the portion where the rear end surface of the main body portion 18a is formed. Therefore, the inner diameter side portion of the cylindrical member 19a located on the rear end side of the coupling portion (the portion on which the rear end surface of the main body portion 18a is formed) is also scraped. Since the cylindrical member 19a is thin, if the inner diameter side portion is scraped, the thickness of the cylindrical member 19a is reduced at the coupling portion and the portion located on the rear end side of the coupling portion. Accordingly, the joint strength of the joint portion and the torsional strength and bending strength of the portion located on the rear end side of the joint portion cannot be ensured.

On the other hand, in the case of the structure of this example, when the inner diameter side portion of the joint portion between the main body portion 18 and the cylindrical member 19 is cut, the portion to be cut is the front end of the cylindrical member 19. Of the inner peripheral edge of the edge and the inner diameter side portion of the main body portion 18, only the portion adjacent to the inner peripheral edge of the front end edge is sufficient. Of course, the portion of the cylindrical member 19 that is located on the rear end side with respect to the coupling portion and the portion other than the front end edge portion of the coupling portion need not be shaved. Therefore, as shown in FIG. 1C, even when the inner peripheral edge of the front end edge portion of the cylindrical member 19 is cut, the strength of the joint portion between the main body portion 18 and the cylindrical member 19 and this The torsional strength and bending strength of the cylindrical member 19 can be sufficiently secured.

Further, the inner peripheral edge of the front end edge of the cylindrical member 19 is cut, and the inner diameter of the portion near the front end of the cylindrical member 19 is equal to or larger than the inner diameter of the main body portion 18. A cylindrical inner column 30 is fitted into the front end portion (left end portion in FIG. 1) of the outer column 10b in such a manner as to be displaceable in the axial direction, thereby forming a telescopic steering column. The inner diameter of the outer column 10b increases from the front side (the left side in FIG. 1) in the order of the main body portion 18 and the cylindrical member 19, so that the outer column is adjusted in accordance with the front-rear position adjustment and secondary collision of the steering wheel. When the column 10b is relatively displaced axially forward with respect to the inner column 30, the rear end edge of the inner column 30 interferes with a portion protruding from the inner peripheral surface of the outer column 10b, and the steering wheel It is possible to suppress the possibility that the forward displacement is hindered. Note that the axial position of the small-diameter portion 32 is set so that the rear end edge of the inner column 30 does not interfere with the inner peripheral surface of the small-diameter portion 32 even when the secondary collision has progressed.

  In addition, since the inner diameter dimension of the front end surface of the cylindrical member 19 is smaller than the portion of the cylindrical member 19 located on the inner diameter side of the portion where the rear end surface of the main body portion 18 is formed, When the molten metal of the light alloy is fed into the mold 21 to form the main body portion 18, the molten metal does not enter the inner peripheral surface side of the cylindrical member 19, and the inner peripheral surface of the cylindrical member 19. However, it is possible to prevent the light alloy from becoming rough due to adhesion of the light alloy.

The column member in each example of the above-described embodiment is used as the outer column 10d of the steering column 2b that constitutes an impact absorption type steering apparatus as shown in FIGS. This steering column device has a telescopic mechanism. That is, the rear end portion of the inner column 30a is fitted into the front end portion of the outer column 10d so that the outer column 10d and the inner column 30a can be displaced in the axial direction. A housing 38 for housing a reduction gear or the like constituting the electric power steering apparatus is coupled and fixed to the front end portion of the steering column 2b (the inner column 30a). Such a steering column 2b has a rear bracket 39 that supports the outer column 10d and front brackets 40 that are provided on the left and right sides of the front end of the housing 38. Support.
Although outside the technical scope of the present invention, a member for a column, such as described above, not only the outer column of a steering column with a telescopic mechanism, it is also possible to apply to the steering column with no telescopic mechanism It is.

DESCRIPTION OF SYMBOLS 1 Car body 2, 2a-2b Steering column 3, 3a Steering shaft 4 Steering wheel 5a, 5b Universal joint 6 Intermediate shaft 7 Steering gear unit 8 Input shaft 9 Tie rod 10, 10a-10d Outer column 11 Outer tube 12 Steering lock device 13 Lock Unit 14 Engaging recess 15 Key lock collar 16 Lock pin 17, 17a Locking hole 18, 18a Main body portion 19, 19a Cylindrical member 20 Axial groove 21 Mold 22 End face 23 Insertion hole 24 Core 25 Tip portion 26 Base End portion 27 Step surface 28a Outer flange 28b Inner flange 29 Protruding portion 30, 30a Inner column 31 Rolling bearing 32 Small diameter portion 33 Small diameter portion 34 Annular portion 35 Projection piece portion 36 Step portion 37 Locking portion 38 Housing 39 Rear side bracket 40 Front bracket 41 Notch

Claims (5)

The whole is a hollow cylinder , and includes a cylindrical inner column and a cylindrical column member. The inner column is fitted inside the column member so as to be axially displaceable. a steering column with a telescopic mechanism that is,
The column member is
It has a light alloy main body and a cylindrical member made of iron-based material,
Of these, the cylindrical member is coupled to the main body portion in the axial direction by internally fitting and fixing the other side end portion to the one side end portion of the main body portion. In addition, a locking through-hole that constitutes a steering lock device is provided, and the other side end surface is subjected to upset molding so that the inner diameter of the other side end edge is the same as that of the other side end. It is smaller than the inner diameter of the portion axially deviated from the other side edge, and the outer diameter of the other side edge is axial from the other side edge of the other side edge. Is larger than the outer diameter of the part
A convex portion is provided on the inner peripheral surface of the one end portion of the main body portion, and a concave portion that engages with the convex portion is provided on the outer peripheral surface of the other end portion of the cylindrical member.
Steering column. The inner diameter of the other end portion of the cylindrical member and the one end portion of the main body portion is equal to or larger than the inner diameter of a portion of the main body portion that is axially removed from the coupling portion with the cylindrical member. The steering column according to Item 1. The whole is a hollow cylindrical shape, and at least a part of the column member includes a light alloy main body portion and a cylindrical member made of an iron-based material,
Of these, the cylindrical member is axially coupled to the main body portion by internally fitting and fixing the other side end portion to the one side end portion of the main body portion. The inner diameter of the other end is smaller than the inner diameter of the portion of the other end that is axially removed from the other end edge, and the outer diameter of the other end is equal to that of the other end. Of these, it is larger than the outer diameter of the portion that is axially removed from the other edge
A method for manufacturing a steering column,
After forming a recess in the outer peripheral surface of the other side end of the cylindrical member,
The other end portion of the cylindrical member is inserted into an insertion hole that opens to the one end portion of the mold, and the other end portion of the cylindrical member is protruded into the mold.
Next, the one end of the core is inserted into the other end of the cylindrical member,
Thereafter, the molten metal is fed into the mold to mold the main body portion, and a part of the molten metal is allowed to enter the concave portion to form a convex portion on the inner peripheral surface of one end portion of the main body portion. By combining the one side end portion of the main body portion and the other side end portion of the cylindrical member in the axial direction and the circumferential direction, the step of obtaining the column member is provided.
A method for manufacturing a steering column. The main body portion is molded so that the inner diameter of the other end edge portion of the cylindrical member is smaller than the inner diameter of the portion of the main body portion that is axially removed from the coupling portion with the cylindrical member, Thereafter, the other end edge portion of the cylindrical member is subjected to cutting, and the inner diameter of the portion subjected to the cutting is set to a portion of the main body portion that is axially removed from the coupling portion with the cylindrical member. The method for manufacturing a steering column according to claim 3, further comprising a step of setting the inner diameter or more. Before the other end portion of the cylindrical member is inserted into the insertion hole of the mold, the other end surface of the cylindrical member is swept and the inner diameter of the other end edge portion of the cylindrical member is formed. Is smaller than the inner diameter of the portion of the other side end portion axially deviated from the other end edge portion, and the outer diameter of the other side end edge portion is set to The method for manufacturing a steering column according to claim 3, further comprising a step of making the outer diameter of a portion deviated in the axial direction from the other end edge portion larger .