JP2002035880A - Manufacturing method of hollow parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out precisely and easily a rolling forming from the outer periphery of a hollow stock. SOLUTION: In the manufacturing method for a hollow parts in which a rolling forming tool is put against the outer peripheral face of a rotating hollow stock 1, a material such as metal, non ferrous metal, resin, etc, melting at 200 deg.C or lower temperature which can easily flow in injection and discharging is filled as a core member 7, 7'.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a hollow component having a hollow shaft portion in order to reduce the weight.

[0002]

2. Description of the Related Art Drive shafts, intermediate shaft joints and the like used as automobile parts have a hollow structure using a tubular member as a material in order to reduce the weight and prevent resonance control. There is something. However, there are cases where serrations or the like are provided on the outer periphery of the shaft portion in this type of component, but since the material is a hollow material, when the above serration is processed using the rolling method of roller rolling or flat die rolling, the hollow is formed. Since a pressing force perpendicular to the radial axis of the material is applied, the cross-sectional shape of the hollow material is deformed, and the roundness cannot be obtained.

Conventionally, for this type of molding, a method of press-molding in the axial direction has been generally used. However, when the work is long, the press machine becomes long, so the cost is reduced. Will be high. Further, it is difficult to process serrations with improved functions having a twist angle.

[0004] The same applies to the case where a gear is provided on the outer periphery of a hollow part. In particular, the bevel gear cannot be processed by a rolling process that presses from the outer peripheral surface.

The present invention has been made in view of the above, and it is possible to perform a process in which a pressing force acts in a direction perpendicular to the axis, for example, an outer peripheral surface rolling process and a spinning process, even for a hollow component. It is an object of the present invention to provide a method for manufacturing a hollow component that can easily perform plastic working.

[0006]

In order to achieve the above object, a method for manufacturing a hollow part according to the present invention is directed to a method for forming a hollow part, which is formed by pressing a rolling tool against an outer peripheral surface of a rotating hollow material. In the manufacturing method, 2
Metals that melt below 00 ° C, or non-ferrous metals, resins, etc.
The plastic working is performed by filling a material that can easily flow at the time of injection and discharge as a core member.

According to this manufacturing method, the core member backs up the inner diameter of the rolled portion. The shape of the hollow portion is not limited, because the core member has fluidity when it is injected into the hollow portion and when it is discharged from the hollow portion.

[0008]

Embodiments of the present invention will be described with reference to the drawings. In this embodiment, a hollow bevel gear shaft is manufactured, and a hollow material 1 shown in FIG. 1 is used. As the hollow material 1, a pipe material made of high carbon steel containing S35C or more carbon suitable for induction hardening was used.

The hollow material 1 is spinned by a spinning roll 2 to form a large diameter portion 3 and a shaft portion 4.

Then, as shown in FIG. 3, the tapered mold 5 is rotated from the distal end side of the large-diameter portion 3 while being pressed in the axial direction, and the outer peripheral side of the large-diameter portion 4 is swaged into a tapered shape. As shown in FIG. 4, a bevel gear material 6 in which a bevel gear portion 3a is formed at the tip of the shaft portion 4 is obtained.

Thereafter, in FIG. 4, a core member 7 made of a metal, for example, tin-bismuth or a resin, for example, nylon 66 (registered trademark), which melts at a temperature of 200 ° C. or less, is injected into the hollow portion of the bevel gear material 6. And solidify by cooling.

Next, as shown in FIG.
Of the bevel gear rolling roll 8 rotating on the outer peripheral surface of the bevel gear portion 3a while the bevel gear material 5 is synchronously rotated via the gripper.
The bevel gear is roll-formed on the outer peripheral surface of the bevel gear portion 3 by pressing the bevel gear from three directions or three directions. Bevel gear part 3 at this time
The rolling pressure acting on "a" is backed up by the core member 7 filled therein, and irregularities of this member are prevented from deformation (distortion).

[0013] The roll forming is performed in a cold state. In the final step, the core member 7 is heated and melted and discharged.

In this embodiment, the inner space of the bevel gear portion 3a of the bevel gear material 6 shown in FIG. 4 is larger in diameter than the opening diameter thereof. Although the solid core having the inner space shape cannot be inserted, the core member 6 described above can be injected and discharged in a molten state, that is, a state having fluidity. The inner space can be densely filled as a member.

FIGS. 6 to 8 show a method of manufacturing the hollow intermediate shaft joint 10 shown in FIG. Both ends of the intermediate shaft joint 10 are smaller in diameter than the intermediate portion, and serrations 11 are formed on both ends.

In manufacturing the intermediate shaft joint 10, first, both ends of the hollow material 12 shown in FIG. 6 are reduced to a predetermined diameter by a spinning roll 13 as shown in FIG. 7, and then as shown in FIG. The same core member 7 ′ as that shown in FIG. 4 in the hollow material 12 is melt-injected and solidified by cooling. Next, the serration die roll 14 is pressed against the outer peripheral surface of the small diameter portion of the rotating hollow material 12, and the serration 11 is roll-formed on this portion. The rolling pressure acting on the small diameter part at this time is
It is backed up by the core member 6 'filled inside, and irregular deformation (distortion) of this portion is prevented, and a perfect circle is maintained.

In each of the above embodiments, an example is shown in which a fixed material that can be melted at a low temperature, such as tin bismuth, is used for the core members 6, 6 '. Alternatively, a fluid material such as water or mud lumps may be used by being sealed inside the hollow.

[0018]

According to the present invention, at the time of rolling of the outer peripheral surface of the hollow portion, the core is backed up by the core member and can be roll-formed without irregular deformation. In particular, by using a material that allows the core member to have fluidity at the time of injection and discharge, the hollow shape inside the rolled portion may have any shape, for example, the deep side is larger than the diameter of the opening end. Even in the case of a hollow shape having a diameter, it can be filled with a core member, and the rolling process of such a hollow member can be performed accurately and easily.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a hollow material.

FIG. 2 is a cross-sectional view showing a spinning process.

FIG. 3 is a cross-sectional view showing a swaging process.

FIG. 4 is a sectional view showing a state in which a core member is filled in a bevel gear material.

FIG. 5 is a cross-sectional view showing a rolling process.

FIG. 6 is a partially broken sectional view showing a hollow material according to another embodiment.

FIG. 7 is a cross-sectional view showing spinning processing according to another embodiment.

FIG. 8 is a cross-sectional view showing a rolling process according to another embodiment.

FIG. 9 is a partially broken sectional view showing a product in another embodiment.

[Explanation of symbols]

1 ... hollow material, 2 ... spinning roll, 3 ... large diameter part, 3
a: bevel gear portion, 4: small diameter portion, 5: taper type, 6: bevel gear material, 7, 7 ': core member, 8: bevel gear roll, 1
0: Intermediate shaft joint, 11: Serration, 12: Hollow material, 13: Spinning roll, 14: Serration die roll.

Claims (1)

[Claims] 1. A method for producing a hollow part, in which a rolling tool is pressed against an outer peripheral surface of a rotating hollow material to perform rolling, wherein a metal or a non-ferrous metal that melts at 200 ° C. or lower in a hollow portion of the hollow material. A method for manufacturing a hollow component, characterized by filling a core member with a material such as resin that can easily flow during injection and discharge.