JPH071071A - Steering lock holder manufacturing method - Google Patents

Abstract

(57) [Abstract] [Purpose] When forming a groove on the side wall of a steering lock holder, prevent burrs from forming on the inner surface of the side wall. A method of manufacturing a steering lock holder (hereinafter, referred to as a lock holder) according to the present invention includes a step of forming a bottomed cylindrical member 22 having an inner diameter larger than an outer diameter of a steering shaft, and a cylindrical member 22. Of forming a through hole 24k having a diameter substantially equal to the outer diameter of the steering shaft in the center of the bottom surface of the, and inserting a cylindrical mold having the same outer diameter as the steering shaft into the inside of the cylindrical member 22 and the through hole 24k. Then, while holding the cylindrical member 22 and the mold in parallel, a part of the side wall of the cylindrical member 22 is pressed from the outside, and the inner surface of the side wall is dented until it contacts the outer peripheral surface of the mold. Forming a groove 22m that can be fitted to the tip of the lock bar on the outer surface of the cylindrical member. As described above, since the groove of the lock holder is formed by denting the side wall of the cylindrical member 22, burrs do not occur on the inner wall surface of the lock holder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a steering lock holder used in a steering lock mechanism of an automobile.

[0002]

2. Description of the Related Art A steering lock mechanism for an automobile is disclosed in Japanese Utility Model Laid-Open No. 60-60348. The steering lock mechanism is a kind of vehicle theft prevention device, the lock bar protrudes by removing the ignition key, by fitting the tip of the lock bar into the groove of the steering lock holder welded to the steering shaft, The rotation of the steering shaft is restricted. The steering lock holder (hereinafter referred to as the lock holder 2) is a cylindrical member as shown in a plan view of FIG. 4 (A) and a sectional view taken along the line BB of FIG. 4 (B). The inner diameter d is set to a value substantially equal to the outer diameter of the steering shaft so that the steering shaft (not shown) can be passed therethrough. Furthermore, on the side wall of the lock holder 2,
A substantially U-shaped notch 2k having a predetermined size is formed in the axial direction, and the notch 2k fits with the lock bar in a state where the lock holder 2 is fixed at a predetermined position on the outer peripheral surface of the steering shaft. Configure a mating groove.

The lock holder 2 is generally shown in FIG.
It is formed by forging according to the processing steps shown in. That is, in the steps of FIGS. 5 (A) to 5 (E), the material is cut, the cut end face is straightened, upset, extruded, and the bottom surface is punched, and the inner diameter ironing is performed in the step of FIG. 5 (F). Formed into a pipe shape. As a result, the inner diameter of the pipe-shaped lock holder 2 becomes substantially equal to the outer diameter of the steering shaft. Next, in the step of FIG. 5G, a substantially U-shaped notch 2k is punched in the side wall of the lock holder 2.

[0004]

However, according to the method of manufacturing the lock holder 2 described above, since the notch 2k of the lock holder 2 is formed by punching, a burr is generated at the portion of the notch 2k. Here, when punching out the notch 2k, a radial force is applied to the side wall of the lock holder 2 from the outside. For this reason, the burr generated in the portion of the notch 2k is generated so as to project inward from the inner wall surface of the lock holder 2. Since such a burr hinders the insertion of the steering shaft into the lock holder 2, a step of removing the burr is required. Further, since the burr is removed by grinding or the like, the lock holder 2
When manufacturing, the grinding machine and the like are required in addition to the forging machine. Therefore, the method of manufacturing the lock holder 2 described above has a problem that productivity is not good. A technical object of the present invention is to forge-mold a groove that fits with a lock bar on the outer surface of a lock holder so that burrs do not occur on the inner wall surface of the lock holder, and a subsequent deburring step can be omitted. It is something to do.

[0005]

The above-mentioned problems can be solved by a method for manufacturing a steering lock holder having the following features. That is, in the method for manufacturing a steering lock holder according to the present invention, the steering shaft of the steering shaft is fixed by being fixed to the outer peripheral surface of the steering shaft and fitted to the tip end portion of the lock bar approaching from the direction intersecting the steering shaft. In a method for manufacturing a steering lock holder that functions to restrict rotation, a step of forming a bottomed cylindrical member having an inner diameter larger than the outer diameter of the steering shaft, and the steering wheel at the center of the bottom surface of the cylindrical member. Forming a through hole having a diameter substantially equal to the outer diameter of the shaft, and inserting a cylindrical mold having an outer diameter equal to the outer diameter of the steering shaft into the cylindrical member and the through hole, By pressing a part of the side wall of the cylindrical member from the outside in a state where the member and the mold are held in parallel, While the inner surface of the side wall of recessed until it abuts against the peripheral surface of the mold, and a step of molding the tip portion fittable groove of the locking bar to the outer surface of the cylindrical member.

[0006]

According to the present invention, a cylindrical mold having the same diameter as the steering shaft is inserted inside the cylindrical member.
The mold is inserted into a through hole formed on the bottom surface of the cylindrical member. This keeps the cylindrical member and the mold substantially coaxial. Furthermore, since the inner diameter of the cylindrical member is larger than the outer diameter of the mold, a predetermined gap is formed between the inner wall surface of the cylindrical member and the peripheral surface of the mold. Next, with the cylindrical member and the mold held in parallel, part of the side wall of the cylindrical member is pressed from the outside. As a result, the side wall of the cylindrical member is recessed, and the inner surface of the recessed side wall is received by the peripheral surface of the mold. As a result, a groove that can be fitted with the lock bar is formed on the outer surface of the cylindrical member, and a receiving surface is formed on the back side of the groove by the peripheral surface of the mold. Since the mold has the same diameter as the steering shaft,
The receiving surface formed inside the cylindrical member can be engaged with the peripheral surface of the steering shaft in a close contact state. As described above, according to the present invention, since the groove of the lock holder is formed by recessing the cylindrical member, no burr is generated on the inner wall surface of the lock holder. For this reason, the deburring step which has been conventionally required is not necessary.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A manufacturing method of a steering lock holder 20 (hereinafter referred to as a lock holder 20) according to an embodiment of the present invention will be described below with reference to FIGS.
Here, FIG. 1 is a plan view and a cross-sectional view of a main part of a lock holder 20 manufactured by a manufacturing method according to this embodiment, and FIGS. 2 and 3 are drawings showing respective manufacturing steps of the lock holder 20. Is. The lock holder 20 is manufactured by cold forging. First, through the steps shown in FIGS. 2A to 2D, namely, the steps of cutting the material, straightening the cut end surface, upsetting, and extruding, as shown in FIG. A thin bottomed cylindrical member 22 is formed. Here, the inner diameter d of the cylindrical member 22 is set to be larger than the outer diameter of the steering shaft (not shown). Next, as shown in FIG. 2E, a through hole 24k having a diameter substantially equal to that of the steering shaft is formed in the center of the bottom surface 24 of the cylindrical member 22 by punching.

Next, the cylindrical member 22 having the through hole 24k formed therein (see FIG. 2E) is set in the forging die 30 shown in FIGS. The steering lock mechanism lock bar (not shown)
A groove 22m that fits with the tip of the is formed. The forging die 30 has a cylindrical punch 32 that axially presses a cylindrical member 22 that is a workpiece, a die 34 that forms a groove 22m on a side wall of the cylindrical member 22, and a center of the die 34. And a cylindrical inner lower die 36 for supporting the cylindrical member 22 coaxially with the die 34.
The die 34 is provided with a cylindrical inner surface-shaped forming surface 34k, and the inlet portion (upper part) of the forming surface 34k can be engaged with the punch 32. Further, the molding surface 34
A pair of ridges 34t are formed in the axial direction (longitudinal direction) at positions opposite to each other across the center at the back (lower part) of k. Here, the width of the protrusion 34t is set to be slightly larger than the width of the lock bar, and the molding surface 34 of the die 34 is
The inner diameter of k is set to a value substantially equal to the outer diameter of the cylindrical member 22.

The cylindrical inner lower die 36 is manufactured so that its outer diameter is equal to the outer diameter of the steering shaft, and further, it is substantially equal to the inner diameter of the cylindrical punch 32. Therefore, the through hole 24 of the cylindrical member 22 that is the work
With the inner and lower molds 36 passed through k, the cylindrical member 22 is supported coaxially with the inner and lower molds 36.
A predetermined gap is formed between the inner wall surface of 2 and the peripheral surface of the inner lower mold 36. Further, when the punch 32 descends while pressing the cylindrical member 22, the inner lower die 36 enters the inside of the punch 32, so that the inner lower die 36 may prevent the lowering of the punch 32. Absent. Such a forging die 3
0, as shown in FIG. 3 (A), the cylindrical member 2
When the punch 32 descends with 2 being set, the cylindrical member 22 is pressed downward by the punch 32,
The space between the molding surface 34k of the die 34 and the inner lower mold 36 is moved inward (downward). As a result, as shown in FIG. 3B, a part of the side wall of the cylindrical member 22 has a pair of protrusions 34t formed on the molding surface 34k of the die 34.
Are pressed in the radial direction from both sides to be recessed, and the inner surface of the recessed side wall is received by the peripheral surface of the inner lower mold 36. As a result, a groove 22m is formed in the vertical direction on the outer surface of the cylindrical member 22, and a receiving surface 22e is formed on the back side of the groove 22m by the peripheral surface of the inner lower mold 36. To be done.

As described above, since the inner lower mold 36 is a cylindrical mold having the same diameter as the steering shaft, the receiving surface 22e formed inside the cylindrical member 22 is the same as the peripheral surface of the steering shaft. Engagement is possible in close contact.
Further, since the inner lower mold 36 is inserted into the through hole 24k of the cylindrical member 22, the receiving surface 22e is concentric with the through hole 24k as shown in FIG. 1 (A). Further, since the cross-sectional area of the groove 22m and the cross-sectional area of the side wall portion which is recessed inward are designed to be substantially equal to each other, the projection 22x protruding from the end surface of the cylindrical member 22 can be suppressed to some extent small. In this way, the groove 22m for fitting with the lock bar is formed on the outer surface of the cylindrical member 22, and the lock holder 20 is completed. Then, the completed lock holder 20 is engaged with a predetermined position of the steering shaft and welded to the outer peripheral surface of the steering shaft. As described above, according to the method of manufacturing the lock holder 20 according to the present embodiment, the groove 2 of the lock holder 20 is formed.
Since 2 m is formed by denting the side wall of the cylindrical member 22, burrs do not occur on the inner wall surface of the lock holder 20. For this reason, the deburring process or the like which has been conventionally required becomes unnecessary. Further, since the cross-sectional area of the groove 22m and the cross-sectional area of the portion where the side wall is recessed inward are designed to be substantially equal to each other, there is almost no surplus and the material yield is good.

[0011]

According to the present invention, since the groove of the steering lock holder is formed by denting the side wall of the cylindrical member, burrs do not occur on the inner wall surface of the steering lock holder. For this reason, the deburring step which has been conventionally required is not necessary, and the productivity is improved.

[Brief description of drawings]

FIG. 1 is a plan view and a cross-sectional view of relevant parts of a steering lock holder manufactured by a method for manufacturing a steering lock holder according to an embodiment of the present invention.

FIG. 2 is a drawing showing each manufacturing process in a manufacturing method of a steering lock holder according to an embodiment of the present invention.

FIG. 3 is a vertical cross section of a forging die used in a method for manufacturing a steering lock holder according to an embodiment of the present invention.

FIG. 4 is a plan view of a conventional steering lock holder,
FIG.

FIG. 5 is a view showing each manufacturing process in a conventional steering lock holder manufacturing method.

[Explanation of symbols]

 20 Steering Lock Holder 22 Cylindrical Member 22m Groove 24k Through Hole 30 Casting Mold 32 Punch 34 Die 36 Inner Lower Mold (Cylindrical Mold)

Claims (1)

[Claims] 1. A steering lock fixed to an outer peripheral surface of a steering shaft and fitted to a tip end portion of a lock bar approaching in a direction intersecting with the steering shaft to restrict rotation of the steering shaft. In the method for manufacturing a holder, a step of forming a bottomed cylindrical member having an inner diameter larger than the outer diameter of the steering shaft, and a step of forming a diameter substantially equal to the outer diameter of the steering shaft at the center of the bottom surface of the cylindrical member. Forming a through hole; inserting a cylindrical mold having an outer diameter equal to the outer diameter of the steering shaft into the inside of the cylindrical member and into the through hole, and holding the cylindrical member and the mold in parallel. In this state, a part of the side wall of the cylindrical member is pressed from the outside, and the inner surface of the side wall is dented until it contacts the peripheral surface of the mold. While letting
And a groove formed on the outer surface of the cylindrical member so that the tip end of the lock bar can be fitted into the groove, the manufacturing method of the steering lock holder.