JP3445526B2 - Manufacturing method of metal cylinder - Google Patents

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 metal cylinder.

[0002]

2. Description of the Related Art A metal cylinder having a small diameter portion above a large diameter portion used for an inner cylinder of a metal vacuum insulated double container made of stainless steel or the like is manufactured. In this case, a brim portion protruding in the horizontal direction is formed in the lower part of the metal cylindrical body, and the punch is inserted to press and hold the brim portion from above and below and to form a large diameter part from the lower opening of the cylindrical body. By doing so, the diameter of the cylindrical body is expanded to form a large-diameter portion (hereinafter referred to as a conventional method).

The flange portion prevents the vertical movement of the cylinder when inserting the punch through the lower opening of the cylinder, and is essential in the method of expanding the diameter by the punch.

However, in this method of manufacturing a metal cylinder,
The lower part of the cylindrical body is expanded at a stretch to form the flange portion, and then the cylindrical body is expanded in diameter.Therefore, when forming the flange portion or expanding the diameter of the cylindrical body, a crack is generated in the flange portion or the large-diameter portion. It may occur.

The present invention has been made in view of the above circumstances, and forms a metal cylinder having a small diameter portion above the large diameter portion without causing cracks in the collar portion or the large diameter portion. It is intended to provide a method for manufacturing a metal cylinder body which is excellent in practicality, productivity and low cost.

[0006]

The gist of the present invention will be described with reference to the accompanying drawings.

[0007] A method of manufacturing a metal tubular body having a small-diameter portion 2 above the large diameter portion 1 with a cylindrical body 3 made of metal, circular
A straight cylindrical body is adopted as the cylindrical body 3, and the first punch 11 having a diverging portion 10 whose diameter becomes smaller toward the front is
The cylindrical body 3 is inserted by inserting it from the lower opening of the cylindrical body 3.
A primary expanded diameter portion 4 having a tapered shape is formed in the lower part of the first punch 11, and the first punch 11 is extracted from the cylindrical body 3 and then the first punch 11 is formed.
By inserting a second punch 16 having an end widening portion 15 that is larger in diameter downward than the end widening portion 10 of the cylindrical body 3 from the lower opening of the cylindrical body 3, A secondary expanded diameter portion 6 having a taper shape with a larger inclination angle with respect to the axis of the cylindrical body 3 is formed in the lower portion of the cylindrical body 3 from the primary expanded diameter portion 4, and after the second punch 16 is extracted from the cylindrical body 3,
The final punch 12 for forming the large diameter portion 1 in the cylindrical body 3,
When the large diameter portion 1 is formed in the cylindrical body 3 by inserting it from the lower opening of the cylindrical body 3, and when the large diameter portion 1 is formed in the cylindrical body 3 by the final punch 12, the secondary expanded portion The present invention relates to a method for manufacturing a metal tubular body, characterized in that a flange 5 is formed at the lower end of the cylindrical body 3 by pressing and sandwiching the lower portion of 6 from above and below.

Further, in the method for manufacturing a metal cylinder according to claim 1 , the secondary expanded diameter portion 6 formed by the second punch 16 is substantially the same as the primary expanded diameter portion 4 formed by the first punch 11. Below the upper secondary expanded diameter portion 6 ′ having the same inclination, a lower secondary expanded diameter portion 6 ″ having a taper shape with a larger inclination angle with respect to the axis of the cylindrical body 3 is connected from the upper secondary expanded diameter portion 6 ′. The present invention relates to a method for manufacturing a metal tubular body, which is characterized in that it has an installed shape.

Further, in the method for manufacturing a metal cylinder according to any one of claims 1 and 2, when the final punch 12 is inserted from the lower opening of the cylinder 3, the metal cylinder is positioned outside the cylinder 3. And the lower die 14 which is in contact with the large diameter portion 1 and is in contact with the lower inner surface of the secondary enlarged diameter portion 6 located below the cylindrical body 3.
The present invention relates to a method for manufacturing a metal tubular body, characterized in that the flange portion 5 is formed at the lower end portion of the cylindrical body 3 by pressing and holding the lower portion of the secondary expanded diameter portion 6 from above and below.

Further, in the method for manufacturing a metal cylinder body according to any one of claims 1 to 3 , a plurality of final punches each having a different diameter are adopted as the final punch 12, and the plurality of final punches have a diameter different from each other. A method for manufacturing a metal cylinder body, characterized in that the cylinder body 3 is gradually expanded in diameter to form a large-diameter portion 1 by inserting and withdrawing the cylinder body 3 from the lower opening in ascending order. is there.

Further, in the method for manufacturing a metal cylinder body according to any one of claims 1 to 4, when the large diameter portion 1 of the cylinder body 3 is formed by the final punch 12, the final punch 12 is cooled. The present invention relates to a method for manufacturing a metal cylinder body, which is characterized by expanding the diameter.

[0012]

The action and effect of the present invention: After the diameter of the lower portion of the cylindrical body 3 is expanded by the first punch 11 to form the primary expanded portion 4, the secondary punch is expanded by expanding the primary expanded portion 4 Forming the expanded portion 6,
After that, since the lower portion of the cylindrical body 3 is further expanded in diameter to form the collar portion 5, the collar portion 5 is gradually formed by a three-step process. The portion 1 is less likely to be cracked, and the metal cylinder having the small diameter portion 2 above the large diameter portion 1 can be manufactured even better.

Therefore, it is easy and inexpensive to form the cylindrical body 3.
A straight cylindrical body is adopted, and a metal cylinder body is available at low cost.
It can be manufactured.

Since the present invention is as described above, it is possible to form a metal cylinder having a small-diameter portion above the large-diameter portion without causing cracks in the collar portion and the large-diameter portion. The manufacturing method of the metal cylinder body is excellent in productivity and cost.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The drawings illustrate an embodiment of the present invention, which will be described below.

In this embodiment, a metal cylinder 7 having a small diameter portion 2 above a large diameter portion 1 used for the inner cylinder of a metal vacuum insulated double container is formed from a metal cylindrical body 3. It is a thing.
The same applies to the case of forming a metal cylinder having a small diameter portion above a large diameter portion used for other purposes, such as an outer cylinder of a metal vacuum insulation double container.

Pre-Process (Formation of Metal Cylindrical Body 3, See FIG. 1) The metal (usually stainless steel is used) cylindrical body 3 is a rectangular metal plate material using an automatic winding machine. Curl to give a cylindrical shape, weld the joint of the cylinder, crush the raised portion of the weld using roller processing, and cut the upper and lower ends of the cylinder with a lathe. Formed by means.

By the way, the cylindrical body 3 shown in the figure is a straight cylindrical body having the same diameter in the vertical direction. This straight cylinder is easier to form and less expensive than a tapered cylinder that widens downward. In this embodiment, the metal cylindrical body 7 having the small diameter portion 2 above the large diameter portion 1 can be formed from this straight cylindrical body . In the conventional example, when the metal cylinder 7 having the small diameter portion 2 is formed above the large diameter portion 1 from the straight cylindrical body, there is a problem that cracks are likely to occur, In practice, a method of forming a metal cylindrical body 7 having a small diameter portion 2 above a large diameter portion 1 from a tapered cylindrical body has often been adopted.

First step (diameter expansion at the first punch 11, FIG.
3) The first punch 11 is inserted from the lower opening of the cylindrical body 3, and is located below the insertion guide portion 17 having the same diameter as the inner diameter of the cylindrical body 3 and has a diverging portion that increases in diameter downward. Ten are lined up.

On the other hand, on the upper part of the cylindrical body 3, the first punch
A first pressing body 18 for pressing and sandwiching the cylindrical body 3 from above and below is provided together with 11.

The first pressing body 18 is inserted from the upper opening of the cylindrical body 3, and is provided with an insertion supporting portion 19 having the same diameter as the inner diameter of the cylindrical body 3.

With this configuration, in the first step, the insertion guide portion 17 of the first punch 11 is inserted into the lower opening of the cylindrical body 3 before the diameter expansion.
And then insert the first pressing body into the upper opening of the cylindrical body 3.
By inserting the insertion support portion 19 of 18 and then narrowing the distance between the first punch 11 and the first pressing body 18 by means such as a press, the diverging portion 10 of the first punch 11 is moved to the lower part of the cylindrical body 3. The primary diameter expansion part 4 is formed in the lower part of the cylindrical body 3 by inserting it in a press-fit state from the opening.

Subsequently, the first pressing body 18 is pulled out from the upper opening of the cylindrical body 3, and the first punch 11 is pulled out from the lower opening of the cylindrical body 3.

Second step (diameter expansion with second punch 16, FIG.
5) The second punch 16 is inserted from the lower opening of the cylindrical body 3 to further expand the primary expanded diameter portion 4 formed by the first punch 11 and has the same diameter as the inner diameter of the cylindrical body 3. Insertion guide part
On the lower side of 20, a diverging end portion 15 having a larger diameter downward than the diverging end portion 10 of the first punch 11 is continuously provided.

Further, the diverging portion 15 of the second punch 16 includes an upper diverging portion 15 'having substantially the same inclination as the diverging portion 10 provided on the first punch 11, and an axis of the cylindrical body 3 rather than the upper diverging portion 15'. This is a configuration in which a lower end flared portion 15 "having a large inclination angle with respect to the heart is continuously provided.

On the other hand, on the upper part of the cylindrical body 3, the second punch
A second pressing body 21 for pressing and sandwiching the cylindrical body 3 from above and below is provided together with 16.

The second pressing body 21 is inserted from the upper opening of the cylindrical body 3 like the first pressing body 18, and is provided with an insertion supporting portion 22 having the same diameter as the inner diameter of the cylindrical body 3. ing.

Further, on the upper portion of the insertion support portion 22, the cylindrical body 3
An inclined portion 23 for forming the upper expanded portion 8 is provided in the upper opening of the. When the cylindrical body 3 is provided with the upper expanded portion 8, when the metal cylinder body 7 formed from the cylinder body 3 is formed on the inner cylinder of the metal vacuum heat insulation double container, the upper opening portion of the inner cylinder is formed. It is possible to make it easier to insert the inner plug into the.

With this structure, in the second step, after the first punch 11 and the first pressing body 18 are extracted from the cylindrical body 3 having the primary expanded portion 4 formed below in the first step, the cylindrical body is extracted. 3, the insertion guide portion 20 of the second punch 16 is inserted into the lower opening portion of the second punch 16, the insertion support portion 22 of the second pressing body 21 is inserted into the upper opening portion of the cylindrical body 3, and then the second punch 16 is inserted. By narrowing the space between the second pressing body 21 and the second pressing body 21 by means such as a press, the divergent portion 15 of the second punch 16 is inserted from the lower opening of the cylindrical body 3 in a press-fitted state, Below the primary expanded diameter portion 4 formed by the first punch 11 and the upper secondary expanded diameter portion 6'which is substantially inclined, the inclination angle with respect to the axis of the cylindrical body 3 is larger than the upper secondary expanded diameter portion 6 '. Secondary expanding portion 6 having a shape in which a lower secondary expanding portion 6 "having a tapered shape is continuously provided.
And the upper expanded portion 8 is formed in the upper opening of the cylindrical body 3. The upper secondary expanded diameter portion 6 ′ may be expanded more than the primary expanded diameter portion 4 by expanding the diameter of the second punch 16.

Subsequently, the second pressing body 21 is extracted from the upper opening of the cylindrical body 3, and the second punch 16 is extracted from the lower opening of the cylindrical body 3.

Third step (formation of collar 5 and final punch 12)
(See FIGS. 6, 7 and 8) The final punch 12 is inserted from the lower opening of the cylindrical body 3, and the secondary expanded portion 6 formed by the second punch 16 and the secondary expanded portion 6 is formed by enlarging the diameter above 6 to form a large-diameter portion 1 in the cylindrical body 3, and an insertion guide portion having the same diameter as the inner diameter of the cylindrical body 3.
A large-diameter insertion portion 25 that can form the large-diameter portion 1 on the cylindrical body 3 is provided below the lower side 24.

The final punch 12 is a lower die 14 for forming a collar for forming the collar portion 5 on the lower portion of the cylindrical body 3 (the lower die referred to in the claims).
It can be installed freely from 14).

The lower mold 14 for forming a collar has a mounting portion 26 on which the cylindrical body 3 having the secondary expanded diameter portion 6 formed by the second step is mounted.
And an upper die 13 for forming a collar that descends from above the cylindrical body 3 (upper die 13 in the claims), and a lower portion of the lower secondary expanded portion 6 "of the cylindrical body 3 from above and below. The flange portion 5 is formed at the lower part of the cylindrical body 3 by being pressed and sandwiched.

When the diameter of the cylindrical body 3 is expanded by the final punch 12, the upper collar forming die 13 is located outside the cylindrical body 3 and contacts the large diameter portion 1 to keep the large diameter portion 1 in a good condition. It also has the function of shaping.

With this configuration, in the third step, the second punch 16 and the second pressing body 21 are extracted from the cylindrical body 3 having the secondary expanded portion 6 formed below in the second step, and then the cylindrical body is extracted. The body 3 is placed on the placing portion 26 of the lower collar forming die 14, and then the upper collar forming die 13 is lowered from above the cylindrical body 3 to form the upper collar forming die 13 and the lower collar forming die. 14 and the lower part of the lower secondary expanded portion 6 "of the cylindrical body 3 is pressed and sandwiched from above and below to form the collar portion 5, and subsequently, the collar forming upper die 13 and the collar forming lower die 14 form a collar. While the portion 5 is being pressed and held from above and below, the final punch 12 is inserted from the lower opening portion of the cylindrical body 3 to form the large diameter portion 1 in the cylindrical body 3.
The remaining portion is the small diameter portion 2.

Further, reference numeral 27 in the drawing is a cooling section for cooling the final punch 12 in the third step, and a refrigerant is passed through the cooling section 27. The cylindrical body 3 is expanded by a method of expanding the diameter of the cylindrical body 3 while cooling the final punch 12 with this refrigerant (a warm drawing method. In this embodiment, the final punch 12 is cooled to about 5 to 6 ° C.). It is possible to prevent evaporation of the attached oil and to prevent the cylindrical body 3 from becoming too soft and breaking.

As described above, by performing the first to third steps, the metal cylindrical body 3 having the small diameter portion 2 above the large diameter portion 1 as shown in FIG. Can be formed.

By the way, when the metal cylinder 7 is manufactured from the stainless cylinder 3, the final punch 12 may not be able to expand the diameter all at once because stainless is a material that is not easily deformed. For example, if SUS304 material with a plate thickness of 0.4 mm is adopted, the diameter expansion that can be performed with one final punch 12 is a radius of 5
mm is the limit, and if the diameter is expanded further, the large diameter part 1
Cracks will occur.

Therefore, when a material used as the cylindrical body 3, for example, stainless steel is used as the material, a plurality of final punches having different diameters are used as the final punches 12, and the plurality of final punches are arranged in the order of decreasing diameter. The cylindrical body 3 is inserted and pulled out from the lower opening of the cylindrical body 3, respectively.
It is advisable to adopt a method in which the large-diameter portion 1 is gradually expanded to form the large-diameter portion 1 on the cylindrical body 3. In this case, instead of the upper collar forming die 13 and the lower collar forming die 14, an upper die and a lower die (not shown) that press and hold the collar portion 5 from above and below may be adopted.

After the third step, the collar portion 5 formed in the lower opening of the metal cylinder body 7 is cut off by means of a lathe or the like (reference numeral 31 is a cutting line), and the metal cylinder body is cut. A bottom body 28 is formed by a process different from the body 7 (for example, by pressing from a metal plate material), and the bottom body 28 is formed in the lower opening of the large diameter portion 1 of the metal cylinder body 7. Attached or
The inner cylinder a of the metal vacuum insulation double container is formed by forming a screwing portion 30 for screwing the inner plug 29 to the small diameter portion 2 of the metal cylindrical body 7. Further, the outer cylinder b of the metal vacuum insulation double container is formed by the same method, and the outer cylinder b and the inner cylinder a are formed.
And the upper opening are integrated by welding or the like, and the outer cylinder b
A metal vacuum adiabatic double container is formed by placing a gap between the inner cylinder a and the inner cylinder a in a vacuum state by an appropriate means (FIG. 9).
reference).

The experimental results of this example are shown below .

In the previous step, SUS with a plate thickness of 0.4 mm
From 304 material, a straight cylindrical body 3 having a height of 220 mm, an outer diameter of φ41 mm, and an inner diameter of φ40.2 mm and having the same upper and lower diameters was formed by welding.

In the first step, the lower portion of the cylindrical body 3 is opened by the first punch 11 to have an outer diameter of 56.3 mm and an inner diameter of 5 mm.
The diameter was expanded to 5.5 mm. Further, the primary expanded portion 4 has a height of 35
mm, and the inclination angle was 13 ° with respect to the axis of the cylindrical body 3.

In the second step, the second punch 16 opens the lower opening of the cylindrical body 3 to an outer diameter of 65 mm and an inner diameter of 64.
The diameter was expanded to 2 mm. Also, the secondary expanded portion 6 has a height of 32 m.
m, the height of the upper secondary expanded portion 6'is 24 mm, the height of the lower secondary expanded portion 6 "is 8 mm, the inclination angle of the upper secondary expanded portion 6'is relative to the axis of the cylindrical body 3. 13 °, lower secondary expanded section 6 "
The inclination angle of was set to 37 ° with respect to the axis of the cylindrical body 3. Further, as the upper expanded portion 8, the upper opening of the cylindrical body 3 has an outer diameter φ.
The diameter was expanded to 43.3 mm.

In the third step, the final punch 12 uses the collar portion 5 (the lower opening portion of the cylindrical body 3) to have an outer diameter of 65 mm and an inner diameter of 6 mm.
4.2 mm, the height of the large diameter portion 1 of the cylindrical body 190 mm (as shown, the upper portion of the large diameter portion 1 is formed in a gentle shape), the outer diameter φ59.4 mm, the inner diameter φ58.6 m
m, the distance from the cylindrical body 3 to the tip of the collar 5 is 3.2 mm,
A metal cylinder 7 having a diameter of 30 mm and a height of 30 mm was obtained. As the final punch 12, three third punches each having a different diameter are adopted, the first final punch has an inner diameter of 46.2 mm, the second final punch has an inner diameter of 52.4 mm, and the third final punch. The inner diameter was gradually increased to 58.6 mm.

The diameter expansion ratio (cylindrical body after diameter expansion / cylindrical body-1 before diameter expansion ) × 100 (%) in this embodiment is (5
8.6 / 40.2-1) × 100 = about 46%, but in the present embodiment, the metal cylinder body 7 is satisfactorily free from cracks and the like.
Could be manufactured.

Further, as a comparative example, when the same diameter expansion ratio as the above-mentioned diameter expansion ratio was applied by the above-mentioned prior art, cracks and distortions were observed in the lower opening of the collar portion 5 and the large-diameter portion 1 in the cylindrical body having the same diameter in the vertical direction. It was found that there was something that occurred and the defect rate was high.

Further, the second step in this embodiment is omitted,
Even if the metal cylinder body 7 was manufactured only in the previous step, the first step, and the third step, the metal cylinder body 7 could be satisfactorily manufactured without cracks and the like. However, if the diameter expansion ratio is increased, it is possible to manufacture a good metal cylinder body 7 with no defective products by gradually expanding the diameter of the lower opening of the cylinder body 3 by including the second step. Become.

Since this embodiment is as described above, the collar 5
Practical use in which a metal cylinder 7 having a small diameter portion 2 above the large diameter portion 1 can be easily formed from a straight cylindrical body 3 having the same diameter in the vertical direction without causing cracks or the like in the large diameter portion 1. sex,
This is a method for manufacturing a metal cylinder body which is excellent in productivity and cost.

The flange portion 5 is formed by the upper collar forming die 13 and the lower collar forming die 14 when the large diameter portion 1 is formed on the cylindrical body 3 by the final punch 12. The upper die 13 is located outside the cylindrical body 3 and abuts against the large diameter portion 1,
Since it has a good shape, the collar portion 5 and the large-diameter portion 1 can be formed in a continuous flow operation. It becomes a manufacturing method.

Further, since the method of forming the upper secondary expanded diameter portion 6'and the lower secondary expanded diameter portion 6 "on the cylindrical body 3 by the second punch 16 is adopted, the portion to be the flange portion 5 and its portion. This is a method of manufacturing a metal cylinder body which is less likely to be affected by a deformation moment or the like in the vicinity thereof and can form the collar portion 5 satisfactorily, and which is further excellent in practicality and productivity.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a pre-process of this example.

FIG. 2 is an explanatory diagram of a first step of this example.

FIG. 3 is an explanatory diagram of a first step of this example.

FIG. 4 is an explanatory diagram of a second step of this example.

FIG. 5 is an explanatory diagram of a second step of this example.

FIG. 6 is an explanatory diagram of a third step of this example.

FIG. 7 is an explanatory diagram of a third step of this example.

FIG. 8 is an explanatory cross-sectional view of a metal tubular body 7 of this embodiment.

FIG. 9 is an explanatory cross-sectional view of a metal vacuum insulated double container of this embodiment.

[Explanation of symbols]

1 large part 2 small diameter part 3 cylindrical body 4 Primary expansion part 5 collar part 6 Secondary expansion part 6'Upper secondary expanded part 6 "lower secondary expansion section 10 End spread part 11 first punch 12 final punch 13 Upper mold 14 Lower mold 15 End spread part 16 Second punch

─────────────────────────────────────────────────── --Continued from the front page (56) Reference JP-A-7-256346 (JP, A) JP-A-60-222607 (JP, A) JP-A-7-32073 (JP, A) JP-A-49- 65974 (JP, A) JP-A-62-296923 (JP, A) Fukuihei 2-32317 (JP, U) Fukuikaihei 2-16229 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B21D 19/08 B21D 22/10 B21D 22/26-22/28 B21D 39/20 B21D 41/02 B21D 51/02 B21D 51/18

Claims (5)

(57) [Claims] 1. A method for manufacturing a metal cylinder having a small diameter portion above a large diameter portion using a metal cylindrical body, the method comprising :
A straight cylindrical body is employed as a first punch having a flared portion which becomes large diameter downwardly, the lower tapered primary enlarged diameter portion of the cylindrical body by inserting the lower opening of the cylindrical body And pulling out the first punch from the cylindrical body, the second punch having a diverging portion that becomes larger in diameter downward than the diverging portion of the first punch is formed in the lower opening portion of the cylindrical body. From the primary expanded portion, a secondary expanded portion having a taper shape with a larger inclination angle with respect to the axis of the cylindrical body is formed in the lower portion of the primary expanded portion of the cylindrical body. After extracting the second punch from the final punch for forming a large diameter portion in the cylindrical body,
A large diameter portion is formed in the cylindrical body by inserting it from the lower opening of the cylindrical body, and when the large diameter portion is formed in the cylindrical body by this final punch, the lower part of the secondary expanded diameter portion is pressed from above and below. A method for manufacturing a metal tubular body, characterized in that a collar portion is formed at a lower end portion of the cylindrical body by sandwiching. 2. The method of manufacturing a metal cylinder according to claim 1 , wherein the secondary expanded portion formed by the second punch has an upper portion that is substantially the same slope as the primary expanded portion formed by the first punch. It is characterized in that a lower secondary expanded portion having a taper shape with a larger inclination angle with respect to the axis of the cylindrical body than the upper secondary expanded portion is continuously provided below the secondary expanded portion. A method for manufacturing a metal cylinder. 3. The method for manufacturing a metal cylinder according to claim 1 , wherein when the final punch is inserted from the lower opening of the cylinder, the diameter is set outside the cylinder. By pressing the lower part of the secondary expanded part from above and below by the upper mold that contacts the large part and the lower mold that is located below the cylindrical body and the inner surface of the lower part of the secondary expanded part contacts A method for manufacturing a metal tubular body, comprising forming a collar portion at a lower end portion of the cylindrical body. 4. The method for manufacturing a metal cylinder according to any one of claims 1 to 3, wherein a plurality of final punches each having a different diameter are adopted as final punches, and the plurality of final punches have a small diameter. Insert in order from the lower opening of the cylindrical body.
A method for manufacturing a metal tubular body, characterized in that a large diameter portion is formed by gradually expanding the cylindrical body by extracting. 5. The method for manufacturing a metal cylinder according to claim 1 , wherein, when forming the large diameter portion of the cylinder by the final punch, the final punch is expanded while being cooled. And a method for manufacturing a metal cylinder body.