JPH04313470A - Manufacture of thin wall cylindrical member - Google Patents

Abstract

PURPOSE:To offer the manufacturing method for a thin wall cylindrical member, which can manufacture the thin wall cylindrical member in which strength of a weld zone is high, and also, a deformation is scarcely generated, and moreover, there are no stain, etc. CONSTITUTION:First of all, a metallic plate 1 is curved to an elliptical shape, each end part is allowed to abut on each other on the minor axis, and the metallic plate 1 is detained by jigs 2a, 2b. In this case, a ratio of the major axis L1 to the minor axis L2 is set to 1.2 to 2.0. Subsequently, each end part of the metallic plate 1 is subjected to electron beam welding. Thereafter, the jigs 2a, 2b are removed. In such a way, a cylindrical member is completed.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a method for manufacturing a thin cylindrical member from a thin metal sheet material, and in particular to a method for manufacturing a thin cylindrical member suitable for manufacturing a thin metal cylindrical member used in the manufacture of eyeglass frames. Regarding the manufacturing method.

0002

BACKGROUND OF THE INVENTION In recent years, cladding materials consisting of a titanium or titanium alloy core material and a gold surface material covering the surface of the core material have come to be used in high-end eyeglass frames and the like.

[0003] As a method for producing a composite material of titanium or titanium alloy and gold, there is a method in which gold as a surface material is directly placed around a core material of titanium or titanium alloy, and both are clad. However, the cladding material manufactured by this method does not have sufficient adhesive strength at the cladding interface between titanium or titanium alloy and gold, and also has large variations in bonding strength. For this reason, common cladding materials for eyeglass frames contain Ni(
It is manufactured by arranging a thin cylindrical member made of nickel and then cladding it.

This Ni thin cylindrical member is required to have high dimensional accuracy since it needs to be inserted between the titanium rod serving as the core material and the gold cylindrical member serving as the surface material. Furthermore, since the cylindrical member itself is subjected to heavy processing in the subsequent cladding material manufacturing process, it is also required that the strength of the cylindrical member itself is high.

FIG. 8 is a schematic diagram showing a conventional method of manufacturing a thin metal cylindrical member.

First, a thin metal plate 11 is curved into a cylindrical shape, and the metal plate 11 is wrapped around a cylinder 12 made of steel or the like, and the metal plate 1 is fixed with a fixing jig 13 so that the ends are in contact with each other.
Fix the end of 1. Next, TIG (tungsten
The ends of the metal plate 11 are welded using an arc welder 14 such as inert gas welding or plasma welding. As a result, a thin metal cylindrical member is completed.

FIG. 9 is a schematic diagram showing another method of manufacturing a conventional thin metal cylindrical member.

First, the thin metal plate 16 is curved into a substantially cylindrical shape and fixed to the fixing jig 17 so that the ends thereof overlap. Next, the ends are overlapped and welded using a resistance welder or the like. As a result, a thin metal cylindrical member is completed.

[0009]

However, the above-described conventional method for manufacturing a thin-walled cylindrical member has the following problems. That is, in the method shown in FIG. 8, if the thin metal plate 11 is curved or the ends are incompletely fixed by the fixing jig 13, the ends will not abut each other accurately, and as shown in FIG. 10(a).
, (b), a gap is created between the ends of the metal plate 11. Then, as shown in Figure 10(c),
Welding creates a dent in the welded portion 15, making it impossible to maintain the required joint strength. On the other hand, if the spacing of the fixing jig 13 is too narrow in order to prevent the generation of the void, an arc will be generated between the welder 14 and the fixing jig 13, as shown in FIG. It becomes impossible to weld the plate 11. Furthermore, if the pressing force by the fixing jig 13 is increased, the metal plate itself will be deformed, as shown in FIG. 12, and the shape of the cylindrical member 11a after welding will deteriorate. Furthermore, if the shielding of the welded part by the shielding gas during welding is incomplete, oxygen and nitrogen in the atmosphere will enter the weld metal, resulting in insufficient strength of the welded part. Furthermore, if there is an oxide film on the surface of the cylindrical member after welding, the bonding strength at the cladding interface will be insufficient when used as a cladding material.

In the method shown in FIG. 9, the welded part 15 bulges out, so when it is made into a cladding material, a step is created in the final product corresponding to this welded part 15, as shown in FIG. 13, which reduces the commercial value. resulting in a decrease in In particular, if a step occurs even in the gold part of the surface, it becomes a fatal defect.

The present invention has been made in view of the above problems, and has high dimensional accuracy of the cylinder, little deformation of the welded part, and suppresses the entrainment of atmospheric gas components into the weld metal. An object of the present invention is to provide a method for manufacturing a thin cylindrical member that can prevent oxidation of the surface of the part.

0012

[Means for Solving the Problems] A method for manufacturing a thin cylindrical member according to the present invention is to curve a metal plate into an elliptical shape, bring the ends of the metal plate into contact with each other on the minor axis of the ellipse, and in this state, the metal plate and a step of welding the ends together by electron beam welding,
The ratio (L
1/L2) is set to 1.2 to 2.0.

[0013]

[Operation] In the present invention, first, a metal plate is curved into an elliptical shape, and the metal plate is restrained by a non-magnetic jig while the ends of the metal plate are in contact with each other on the minor axis of the ellipse. In this way, by curving the metal plate into an elliptical shape and making the ends contact each other on the minor axis, the ends will contact each other on a substantially flat surface, and will not contact each other on the curved surface. Unlike the case, it is possible to suppress the generation of voids between the ends.

[0014] Next, the ends of the metal plates are electron beam welded together. Electron beam welding requires smaller welding heat input than arc welding such as TIG welding, so the beat width is narrower and material deformation due to welding is less. Also,
Since electron beam welding is performed in a vacuum, oxidation of the surface of the metal plate and intrusion of gas components into the weld metal can be prevented. As a result, in the cylindrical member manufactured by the method of the present invention, the strength of the welded portion is high, and stains such as oxidation do not occur on the surface of the welded portion.

Therefore, for example, when a cylindrical member made of Ni is manufactured according to the present invention and this cylindrical member is used for manufacturing a cladding material for eyeglass frames, there is little deformation and there is no stain such as oxidation, so that the cylindrical member after manufacture is The member can be used as is and can be bonded to titanium and gold with high strength.

Furthermore, in the method of the present invention, since the jig for restraining the metal plate is made of a non-magnetic material, beam deviation (so-called beam deflection) in electron beam welding can be avoided. Note that if this jig is made of aluminum or aluminum alloy, the jig can be made lighter and therefore easier to carry. This makes it easy to manufacture a plurality of thin-walled cylindrical members at once even in a batch production system in a vacuum, resulting in good productivity. Therefore, it is preferable that the jig is made of aluminum or an aluminum alloy.

When a metal plate is restrained into an elliptical shape using a jig, if the ratio of the major axis L1 to the minor axis L2 of the ellipse (L1/L2) is less than 1.2, the edges of the metal plate are tightly bound together. It is difficult to fix them so that they are in contact with each other without creating any gaps. On the other hand, if the ratio of the major axis to the minor axis exceeds 2.0, there is a risk that the metal plate will be plastically deformed, and a process of modifying the shape may be necessary after welding. Therefore, when a metal plate is restrained into an elliptical shape by a jig, the ratio of the major axis to the minor axis of the ellipse needs to be 1.2 to 2.0.

[0018]

Embodiments Next, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing a method of manufacturing a thin cylindrical member according to an embodiment of the present invention.

First, the thin metal plate 1 is curved into an elliptical shape, and as shown in a partially enlarged view in FIG. This metal plate 1 is restrained by jigs 2a and 2b. In this case, the ratio α (L1/
L2) is set to 1.2 to 2.0.

Next, the ends of the thin metal plates 1 are electron beam welded together in a vacuum. After that, jig 2a
, 2b. Due to the elastic force of the metal,
The member is deformed from an elliptical shape to a circular shape, and a thin metal cylindrical member is completed. In addition, in order to improve the roundness of the thin cylindrical member, the cylindrical member 1a may be formed using a three-roll forming machine 3 shown in FIG.

As shown in FIG. 4, the thin-walled cylindrical member 1a manufactured in this way has a good cylindrical shape with few variations in plate thickness such as dents in the welded part 4. can. Moreover, since the ends of the metal plates 1 are in close contact with each other during welding, the clamping force by the jigs 2a and 2b may be small. Thereby, deformation of the cylindrical member 1a due to the jigs 2a and 2b can be suppressed.

The method of this embodiment can be applied not only to the production of metal cylindrical members used as cladding materials for eyeglass frames, but also to the production of thin metal cylindrical members having a desired outer diameter.

Next, the results of actually manufacturing a thin cylindrical member using the method of the present invention will be explained.

First, a Ni plate with a thickness of 0.7 mm was bent into a substantially cylindrical shape with a length of 210 mm and an outer diameter of 83 mm, and then the ratio α of the major axis to the minor axis was as shown in Table 1 below. It was restrained by an aluminum jig so as to have the same value.

Next, the ends of these Ni plates were electron beam welded under the conditions shown in Table 2 below. Then, the shape and strength of the welded portion of the cylindrical members manufactured according to these Examples and Comparative Examples were examined. The results are also shown in Table 1. However, regarding the shape of the welded part and the strength of the welded part, good cases are indicated by ○, poor cases are indicated by ×, and intermediate cases are indicated by △. Furthermore, from these results, the suitability of the cylindrical member as a cladding material was comprehensively evaluated. The results are also shown in Table 1. However, cases where the material is suitable as a cladding material are indicated by ○, and cases where it is unsuitable are indicated by ×.

As is clear from Table 1, the cylindrical members manufactured according to Examples 1 to 9 of the present invention are used as cylindrical members disposed between the core material and the surface material when manufacturing the cladding material. The shape and strength were good. On the other hand, the cylindrical members manufactured in Comparative Examples 1 and 2, in which the ratio of the major axis to the minor axis was small, had unsatisfactory joint shapes and strengths.

[0028]

[Table 1]

[0029]

[Table 2]

Next, the results of manufacturing thin cylindrical members using various jigs made of different materials will be explained. First of all,
A Ti plate with a thickness of 0.6 mm and a length of 180 mm.
It was curved into a substantially cylindrical shape with an outer diameter of 76 mm, and was restrained with a jig made of the material shown in Table 3 below so that the ratio α of the major axis to the minor axis was 1.5.

Next, the ends of these Ti plates were electron beam welded together under the conditions shown in Table 4 below. Then, the deviation of the beam during welding and the weight of the jig were investigated. The results are also shown in Table 3. However, in the beam deviation column, cases where the beam was successfully welded without any beam deviation during welding are indicated by ○, and cases where beam deviation occurred during welding are indicated by ×. In addition, in the weight column, cases where the item is lightweight and easy to carry are indicated by ○, and cases where it is not easy to carry are indicated by x.

[0032]

[Table 3]

[0033]

[Table 4]

As is clear from Table 3, in Example 10, which uses an aluminum jig, there is no beam shift during welding, and it is lightweight and easy to carry.
It is extremely excellent as a jig used for manufacturing cylindrical members. On the other hand, in Comparative Example 4 in which a jig made of a magnetic material (carbon steel) was used, beam deviation occurred during welding, and good welding could not be performed. Furthermore, in Comparative Examples 3 and 5, in which non-magnetic materials such as copper and austenitic stainless steel were used, respectively, no beam deviation occurred during welding. However, the jigs used in Comparative Examples 3 and 5 were not suitable as jigs for use in manufacturing cylindrical members because the jigs were heavy and not easy to carry. .

Next, a comparative example will be described in which a metal plate is curved into an elliptical shape and welding is performed such that the ends abut each other on the major axis of the ellipse.

First, a Ti plate with a thickness of 0.6 mm was curved into a substantially cylindrical shape with a length of 180 mm and an outer diameter of 76 mm, and then bent so that the ratio α of the major axis to the minor axis was 0.8. Then, as shown in FIG. 5, the Ti plate 21 was fixed with a jig 22. In this case, as shown in the partially enlarged view of FIG.
A void was formed between the ends. Next, the ends were electron beam welded together. As a result, as shown in FIG. 7, a dent occurred in the welded portion 23, and the joint strength was insufficient.

[0037]

As explained above, according to the method of the present invention, a metal plate is curved into an elliptical shape and restrained in this state, and the ends of the metal plate are welded together by electron beam welding.
A thin cylindrical member made of metal can be manufactured with high dimensional accuracy. This produces the effect that a high-quality cladding material with high bonding strength and no deformation can be manufactured.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a method for manufacturing a thin cylindrical member according to an embodiment of the present invention.

FIG. 2 is a partially enlarged view of the same.

FIG. 3 is a schematic diagram showing a three-roll molding machine.

FIG. 4 is a schematic cross-sectional view showing a welded portion of a cylindrical member manufactured by an example method of the present invention.

FIG. 5 is a schematic diagram showing a method for manufacturing a thin cylindrical member according to a comparative example method of the present invention.

FIG. 6 is a partially enlarged view of the same.

FIG. 7 is a schematic cross-sectional view showing the welded portion.

FIG. 8 is a schematic diagram showing a conventional method for manufacturing a thin-walled cylindrical member.

FIG. 9 is a schematic diagram showing another method of manufacturing a conventional thin-walled cylindrical member.

FIGS. 10(a), (b), and (c) are all schematic diagrams showing problems in the conventional manufacturing method of a thin-walled cylindrical member.

FIG. 11 is a schematic diagram illustrating problems in the conventional thin-walled cylindrical member manufacturing method.

FIG. 12 is a schematic diagram showing problems in the conventional method for manufacturing a thin-walled cylindrical member.

FIG. 13 is a schematic diagram illustrating problems in the conventional thin-walled cylindrical member manufacturing method.

[Explanation of symbols]

1, 11, 16, 21; metal plate 2a, 2b, 13, 17, 22; jig 3; Molding machine 4, 15, 23; Welded part 14; Welder

Claims (2)

[Claims] 1. A step of curving a metal plate into an elliptical shape, bringing the ends of the metal plate into abutment on the minor axis of the ellipse, and restraining the metal plate in this state with a jig made of a non-magnetic material; and a step of welding the parts together by electron beam welding,
The ratio (L
1/L2) is set to 1.2 to 2.0. 2. The method of manufacturing a thin cylindrical member according to claim 1, wherein the jig is made of aluminum or an aluminum alloy.