JP2003236635A - Dome used for aluminum alloy pressure vessel, and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dome to be used for an aluminum alloy pressure vessel in which neither a large plate nor a large exclusive machine is used and any skill is not required when manufacturing a large dome of complicated plate thickness distribution. <P>SOLUTION: A method in which a large plate formed by friction stirring and joining of a plurality of aluminum alloy plates is formed in a substantially dome shape by the cold spinning, and the dome-shaped structure is tempered and subjected to the chemical milling and machining to manufacture a one-piece type dome having a T-shaped flange 20 on a skirt part 2, includes a spinning step of tearing a strip-like thick-walled part of the skirt part 2 of the thin-walled dome manufactured while the strip-like thick-walled part is left in a step manner on the skirt part 2 out of the large plate during the cold spinning along the circumference to a predetermined depth, forming an outer cylinder and an inner cylinder extending from a common cylinder which is left without any tear, and realizing predetermined expansion diameter and predetermined wall thickness of the outer cylinder in the direction substantially perpendicular to the axis of the cylinder. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dome (end plate) used for an aluminum alloy pressure vessel, particularly a rocket tank dome and an aircraft pressure bulkhead dome, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a tank for filling liquid hydrogen or liquid oxygen in a rocket is made of an aluminum alloy, and a dome partition wall is joined to a cylindrical portion of an isogrid structure whose inner surface is machined in a lattice pattern. .

Conventionally, such a dome has a plate thickness of 50 to 70.
It is manufactured by spinning a custom-made large plate of about 5 mm by 5 mm while heating it, and then thinning it by spinning and machining.

[0004]

[Problems to be Solved by the Invention] Not only are there few manufacturers who can manufacture custom-made large plates with a plate thickness of about 50 to 70 mm and about 5 × 5 m, but they are also expensive, and dome shapes are made from large plate materials by spinning. It is technically difficult to process. Further, in the spinning forming process that requires heating, an expensive dedicated device is required to process the large plate as described above while using the mandrel having the inner surface shape of the roller and the dome. Furthermore, it takes a huge amount of machining time to machine a thick dome material manufactured by the spinning process into a thin tank dome. In addition, the rocket dome must not be provided with an extra wall thickness, and must be provided with a cylindrical part and a joint part for connecting with other members. Is extremely complicated.

In order to solve such a problem, a step of forming a desired thickness distribution by changing the thickness from the inner shape side,
At a temperature of 200 to 250 ° C, a step of performing hot spinning forming, a solution treatment, a straightening forming treatment, a step of performing a predetermined aluminum alloy treatment including an aging treatment, and a joint or other peripheral protruding portion by chemical processing such as etching. A method of manufacturing a rocket dome by the process of forming a rock has been proposed.

However, even in such a conventional technique, there is a problem that a large-scale dedicated device must be used for the thickening processing of a large plate, and the shape precision is poor because all the shape machining is plastic working. . Especially in the state where the thickness distribution on the inner diameter side of the large plate of the thick plate is formed, since it is thick, it must be performed hot in order to spin this into a dome shape. Need.

In view of the above problems, the present invention provides a large dome (end plate) for use in an aluminum alloy pressure vessel, particularly a large dome such as a rocket tank dome having a complicated plate thickness distribution. It is an object of the present invention to provide a tank dome made of an aluminum alloy and a method for manufacturing the same, without using the plate material or the large-sized special machine and requiring no skill. Another object of the present invention is to manufacture a large dome using an aluminum plate having a width of about 3 m which is usually sold. Furthermore, the outer shell that is now subdivided in the radial direction is assembled with rivets, and the rivet holes and outer shell joints are sealed with resin, etc. The purpose is to

[0008]

In order to solve the above problems, the present invention forms a large dome shape by cold-spinning a large sized plate material formed by friction stir welding of a plurality of aluminum alloy plate materials. After that, a dome for use in an aluminum alloy pressure vessel, characterized in that the dome shape is formed by chemical milling and mechanical finishing after tempering, is proposed.

The invention as defined in claim 3 relates to a preferred manufacturing method for manufacturing the dome according to claim 1.
A step of forming a large plate material having a diameter larger than the dome by friction stir welding of a plurality of aluminum alloy plate materials, annealing the large plate material as necessary, and then cooling the large plate material in a dome shape. It has a spinning process and a heat treatment such as solution treatment and aging treatment for tempering, and finishes such as straightening, chemical milling, and machining as necessary after the tempering. A method for producing a dome for use in an aluminum alloy pressure vessel, which is characterized by comprising a step of forming a dome by processing.

Here, the friction stir welding means that the joining surfaces of the aluminum alloy plates are fixed in a state of being abutted with each other, and the protrusions are inserted between the abutting faces of the aluminum alloy sheets while rotating the rotary tool at a high speed. , Run at a constant speed.
At this time, the aluminum alloy material is heated to the recrystallization temperature by friction between the protrusion and the abutting surface of the aluminum plate, and atoms are mixed by substitution to bond the abutting surface of the aluminum alloy plate.

Since the flat plate material joined by the friction stir welding does not deform like the welded joint, it is not necessary to correct the strain, and the process directly shifts to the cold spinning step of the next step. However, since the aluminum alloy material is heated up to the recrystallization temperature, there is a possibility that the joining portion is hardened similarly to quenching. Therefore, in the present invention, a large-sized plate material is annealed as needed, and then cold-spun in accordance with a dome shape.

As shown in FIG. 1, the present invention is not limited to a two-piece dome in which the skirt portion 2 having the T-shaped flange portion 20 and the dome body 1 are separated from each other.
As shown in (A), the T-shaped flange 20 is provided on the skirt portion 2A.
It can also be applied to the case of manufacturing a one-piece dome 1A including A. As a specific example thereof, as described in claim 2, the skirt portion of a thin dome manufactured in a state in which a strip-shaped thick portion is left in the skirt portion in a step shape from a large plate material during the cold spinning. The strip-shaped thick wall portion of is cleaved along the circumference to a predetermined depth to form an outer cylinder and an inner cylinder extending from the common cylinder that remains without cleaving, and the outer cylinder is substantially aligned with the cylinder axis. We propose a one-piece dome having a T-shaped flange on the skirt, which is characterized in that a predetermined overhang diameter and thickness are formed vertically.

As a preferred example of the method for manufacturing a one-piece dome having a T-shaped flange on the skirt,
In the cold spinning step, a step of manufacturing a thin dome in a state in which a strip-shaped thick portion is left in a stepped shape on a skirt portion from a large plate material, and a predetermined step is performed along the circumference of the strip-shaped thick portion of the skirt portion. Cleavage to a depth to form an outer cylinder and an inner cylinder extending from a common cylinder that does not cleave and form a predetermined overhang diameter and wall thickness approximately perpendicular to the cylinder axis. And a step of performing a spinning process.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to the embodiments shown in the drawings. However, unless otherwise specified, the dimensions, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention thereto, but are merely illustrative examples. FIG. 1 shows an embodiment of a two-piece dome in which a skirt body having a T-shaped flange portion and a dome body are separated from each other on the upper and lower sides of a cylinder skin (cylindrical portion) 3 in a rocket tank manufactured according to the present invention. , These are individually manufactured, and then the tank is completed by welding.

Next, a method for manufacturing the dome body will be described. First, for example, three aluminum alloy plates having a thickness of 30 mm and a size of 3 meters × 6 meters are prepared. Aluminum alloy plates with a thickness of 30 mm and a width of 3 meters are manufactured by many manufacturers, and their procurement is not expensive.

Next, the processing operation for joining the two aluminum alloy plates 10 and 10 using the friction stir welding machine shown in FIG. 3 will be described. As shown in FIG. 3, a joining disc having a protrusion in the center is attached to a rotary tool, and then, as described above, the two joining aluminum alloy plates 10 and 10 are mounted on a bed (not shown). Then, the two are fixed in a state where the joint surfaces are abutted. In this state, the protrusion 17 is formed on the aluminum alloy plate 1 while rotating the rotary tool 18 at a high speed by a servo motor (not shown).
While being inserted from the side portion of 0 between the abutting surfaces 11, the joining disc 19 is abutted on the upper surface of the aluminum alloy plate 10 and is run at a constant speed in the direction indicated by the arrow b. At this time, the aluminum alloy 10 is raised to the recrystallization temperature by friction between the protrusions 17 and the abutting surfaces 11 of the aluminum alloy plates 10 and 10, and the abutting portions are mixed by atomic replacement to form the abutting surfaces 11 of the aluminum plates 10 and 10. Join. At this time, the upper surface of the joining portion 16 is formed into a flat shape by the joining disc 19, and the lower surface thereof is pressed against the upper surface of the bed (not shown) to be a mirror surface.

In the friction stir welding method, unlike the conventional welding method, the aluminum plate 10 does not reach such a high temperature, and only the narrow range around the rotary tool 18 is in contact.
Since only a slight amount of heat is applied, it is not necessary to firmly fix the entire aluminum plates 10 and 10 and the welded portion to each other as in the case of welding. It is only necessary to fix the four corners, and the fixing of the joint is not necessary. In addition, the rotary tool 18
However, as the joining surface is pushed while joining, and the heat does not rise so much, the joint portion 16 is distorted by thermal expansion,
It is possible to join without stretching and without fixing the joining surface.

As described above, the two aluminum alloy plates 10 and 10 are joined by friction stir welding to produce a flat plate material having a wide width of 6 m, for example. In this case, the joining portion is formed into a flat shape by the joining disc, and the lower surface is pressed against the upper surface of the bed to form a mirror surface.

Next, since the wide mirror-like flat plate members joined by the friction stir welding are heated to near the melting point, the same treatment as in the quenching state is carried out. Annealing is performed to soften the joint portion 16.

Next, the wide flat plate material is machined into a disk shape and then processed into a dome shape by cold spinning as shown in FIG. Since the mirror-like flat plate material 10 joined by the friction stir welding method does not deform like welding joining, it is not necessary to correct the strain, and after the annealing treatment, it is used for cold spinning as it is. Figure 4
It is possible to set in the device shown in.

First, the cold spinning apparatus 40 is shown in FIG.
As shown in FIG. 4, the rotating main shaft 42 and the upper surface coupled to the rotating main shaft 42 are composed of a mirror-like mandrel 43, a blank support shaft 44, and a processing roller 41. The mandrel 43 is located on the lower surface of the mirror-like flat plate member 10 and The processing roller 41 rotates with the main shaft 42, is attached to the roller support arm 47, and is configured to be movable in two axial directions by the guide cylinder 48 and the arm axial movement cylinder 49 via the roller support arm 47. While rotating the aluminum alloy plate member 10 which is rotated by the support shaft 44 of the flat plate member 10
A pressure is applied to the upper surface of the processing roller 41 by the processing roller 41, and further, the processing roller 41 is moved from the inner diameter side to the outer diameter side along a locus substantially along the surface shape of the mandrel to process the flat plate material into a dome shape. A flat cylindrical rocket tank dome material as shown in 1 is formed.

Then, the dome material as described above is subjected to solution heat treatment according to a conventional method by heating at 535 ° C. for 2 hours and then rapidly cooled, and then this solution heat treated tank dome material is subjected to straightening forming processing, This is subjected to an aging treatment at 191 ° C. for 36 hours. Next, port 1b and manhole 1a of the dome
(Both see FIG. 1) and the inner side of the dome is processed to form the rocket tank dome body 1.

In this embodiment, as shown in FIG. 1, the ring-shaped skirt portion 2 having the T-shaped flange portion 20 provided on the outer periphery of the bottom of the dome and the dome body 1 above the ring-shaped skirt portion 2 are separately formed. However, as shown in FIG. 2B, it is possible to integrally form the ring-shaped skirt portion 2A having the T-shaped flange 20A provided on the outer periphery of the bottom of the dome and the dome body portion 1A above the ring-shaped skirt portion 2A. According to the invention, a dome corresponding to the intermediate stage can be manufactured.

A ring-shaped skirt portion 2A having a T-shaped flange 20A provided on the outer periphery of the bottom of such a dome.
FIG. 2B shows a completed perspective view of what is integrally formed with the dome main body portion 1A above it. The drawings are attached to the upper and lower sides of the cylinder skin 3 in the rocket tank manufactured according to the present invention.
It is an embodiment of a one-piece dome in which a skirt portion having a T-shaped flange portion 20A and a dome body 1A are integrated, and a large number of radial ribs 61 are extended on the upper surface of the dome body 1A, and between the ribs 61. A cylindrical hole 62 such as a port or manhole is formed in the center.

FIG. 5 shows a method of manufacturing an aluminum alloy tank dome having a T-flange according to the present invention. The two aluminum alloy plates 10 are joined by friction stir welding to produce a wide flat plate material, which is annealed to soften the joining portion and then machined into a disc shape. Next, the upper surface is processed into a dome shape together with the ribs 61 by cold spinning processing shown in FIG. Further, a T-shaped flange 20A is manufactured on the skirt portion 2A by the following spinning process. Figure 5 shows T of the skirt 2A
It is a conceptual diagram which shows the outline of the manufacturing process of 20 A of mold flanges. FIG. 6 is a schematic sectional view showing a spinning molding device. 5 to 6, 12 is a spinning roller for cleaving, 14 is a spinning roller for molding, 21 is a mandrel for a dome, 22 is a mandrel for a flange, and 23 is a center of rotation with the material fixed together with the mandrel. It is a disk part.

FIG. 6 shows a state in which the skirt portion of the dome is chucked in the spinning molding machine. Figure 5 (A)
In the above, after the dome was produced by the cold spinning process so that the skirt portion had a thickness of 24 mm, the skirt portion 11 was formed into a spinning molding machine as shown in FIGS. 5 (B) and 6 (A). The dome mandrel 21 and the flange mandrel 22 together with a disk portion 23 having a rotating means (not shown) by a fixing means (not shown),
While rotating around the center of the cylinder, 1
While rotating the cleaving roller 12 by a rotating means (not shown) along a circumference of 2 mm, the cleaving roller 12 is pressed and cut to a depth of 30 mm to form a cleaving groove, and the inner cylinder 2B having a wall thickness of approximately 12 mm and the meat are formed. The outer cylinder 20A 'having a thickness of approximately 12 mm was divided.

Next, as shown in FIGS. 5 (C) and 6 (B), the outer cylinder 20A 'is spread at a right angle to the central axis of the cylinder by a molding spinning roller 14 rotated by a rotating means (not shown), and an overhang of 45 mm. , Molding a 12mm thick tsuba,
A near net shape material was produced.

Then, the dome material as described above is applied at 535 ° C.
After heating for 2 hours, it was rapidly cooled for solution treatment. Next, the solution-treated dome material is subjected to a straightening forming process, and then subjected to an aging treatment at 191 ° C. for 36 hours.

Finally, after processing the ports, manholes, etc. of the dome and the inner shape side, the inner cylindrical portion 2B and the outer cylindrical portion 20A 'are finished to a design shape as the T-shaped flange portion 20A by machining with a lathe. It was As a result, FIG.
A high-strength aluminum alloy tank dome 1A having a T-shaped flange 20A, in which a collar of 40 mm in radial direction and a thickness of 10 mm is projected from a skirt portion 2A having a thickness of 10 mm shown in (D), is manufactured.

In any of the above embodiments, the material cost and processing time can be reduced without using a thick and large aluminum alloy material, and a dome (end plate) used for an aluminum alloy tank, particularly a rocket tank. Tanks made of aluminum alloy without using a large plate material or a large dedicated machine when manufacturing a large dome with a complicated plate thickness distribution like the dome It became possible to easily manufacture the dome. A dome manufactured by the same manufacturing method is an aircraft pressure bulkhead that is currently manufactured by assembling outer shells that are currently subdivided in the radial direction with rivets and sealing the rivet holes and outer shell joints with resin or the like. It can also be applied as a single dome component.

[0031]

As described above, according to the present invention, when manufacturing a dome (end plate) used for an aluminum alloy pressure vessel, especially a large dome having a complicated plate thickness distribution such as a dome of a rocket tank. In addition, it is possible to obtain an aluminum alloy tank dome without using a large plate material or a large dedicated machine and without requiring any skill level. Especially, an aluminum plate with a width of about 3 m which is usually sold. Can be used to manufacture large domes.

[Brief description of drawings]

FIG. 1 shows an embodiment of a two-piece dome in which a skirt body having a T-shaped flange portion and a dome body are separated from each other on the upper and lower sides of a cylinder skin in a rocket tank manufactured according to the present invention. .

FIG. 2 shows an embodiment of a one-piece dome in which the skirt portion and the dome body are integrated, (A) is a schematic sectional view, and (B) is a perspective view.

FIG. 3 is a schematic diagram illustrating a processing operation when friction stir welding two aluminum alloy plates.

FIG. 4 is a conceptual diagram showing a cold spinning processing apparatus for forming a dome from a flat plate material.

FIG. 5 is a conceptual diagram showing the outline of the manufacturing process of the T-flange of the skirt portion.

FIG. 6 is a schematic cross-sectional view showing a spinning molding device.

[Explanation of symbols]

2-piece type dome (20: T-type flange +2: skirt + 1: dome body) 1-piece dome (20A: T-type flange +2)
A: Skirt + 1A: Dome body) Friction stir welding machine (18: Rotating tool +20: Protrusion) Cold spinning machine for dome forming (42: Spindle main spindle +43: Mandrel +44: Blank support shaft +4
1: Processing roller)

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B64C 1/10 B64C 1/10 F02K 9/60 F02K 9/60 // B23K 101: 12 B23K 101: 12 103 : 10 103: 10 (72) Inventor Takayuki Tsuzuki 10 Oe-cho, Minato-ku, Nagoya Mitsubishi Heavy Industries Ltd. Nagoya Aerospace Systems Works F-term (reference) 4E067 AA05 BG00 DD02 EA06 EB06 EC01

Claims (4)

[Claims] 1. A large sized plate material formed by friction stir welding of a plurality of aluminum alloy plate materials is formed into a substantially dome shape by cold spinning, and after the dome shape is tempered, chemical milling and machining are performed. A dome used for aluminum alloy pressure vessels, characterized by being formed by finishing. 2. A thin dome manufactured in a state in which a strip-shaped thick portion is left in a skirt portion from a large-sized plate material during the cold spinning, and the strip-shaped thick portion of the skirt portion is formed along a circumference. To a predetermined depth to form an outer cylinder and an inner cylinder extending from the common cylinder that remains without being cleaved, and the outer cylinder has a predetermined overhang diameter and wall thickness that are substantially perpendicular to the cylinder axis. The skirt is characterized by being formed with T
The one-piece dome according to claim 1, further comprising a mold flange. 3. A step of forming a large plate material having a diameter larger than the dome diameter by friction stir welding of a plurality of aluminum alloy plate materials, a step of cold spinning the large plate materials in a dome shape, and tempering A method for producing a dome for use in an aluminum alloy pressure vessel, comprising a step of forming a dome by a finishing process including a chemical milling process and a machining process after the heat treatment. 4. A method for manufacturing a one-piece dome having a T-shaped flange on a skirt portion, wherein the cold spinning step leaves a thick plate portion in a step shape on the skirt portion from a large plate material. A step of manufacturing a thin dome, and an outer cylinder and an inner cylinder extending from a common cylinder that remains without cleaving, by cleaving the band-shaped thick part of the skirt to a predetermined depth along the circumference 4. The aluminum alloy pressure vessel according to claim 3, further comprising a step of spinning the outer cylinder so as to form a predetermined overhanging diameter and wall thickness substantially perpendicular to the cylinder axis. Dome manufacturing method.