JP4281510B2 - Vacuum container manufacturing method - Google Patents

Description

The present invention, for example a method of manufacturing a vacuum container to be used in such a semiconductor device manufacturing process.

In a semiconductor manufacturing process, a vacuum container whose internal space is highly vacuum and highly clean is used. Such a vacuum vessel is made of, for example, aluminum or an alloy thereof, and each part has a thickness of several tens of millimeters. In order to manufacture such a vacuum vessel with less material and processing cost, the following proposals have been made.
That is, a pair of members made of aluminum or an alloy thereof and having a substantially channel-shaped or L-shaped cross section is prepared, and friction stir welding is performed by sliding a tool that rotates along a groove provided on these butting surfaces. A method for manufacturing a chamber has been proposed (see, for example, Patent Document 1).
There is also a method for manufacturing a vacuum chamber in which a pair of members having a substantially channel shape in cross section similar to the above are prepared, and a tool that rotates inside the square tube formed by abutting these grooves is slid and friction stir welding is performed. It has been proposed (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 11-291068 (pages 1 to 4, FIGS. 1 to 3) Japanese Patent Laid-Open No. 11-300480 (pages 1 to 4, FIGS. 1 to 3)

  However, in each of the above manufacturing methods, a pair of substantially channel-shaped or L-shaped members made of an aluminum alloy are used, so that the processing cost increases due to cutting or extrusion molding, and the friction stir welding is performed. However, there is a problem that a special restraining jig is required. Moreover, in the method of inserting a rotating tool inside the rectangular tube and sliding along the groove, it is impossible to manufacture if a lathe or milling machine that supports the tool does not enter the rectangular tube. It was.

The present invention is to solve the problems of the background art described in the above, to provide a production method capable of providing a vacuum vessel that give the inner space to facilitate a high vacuum and highly clean and securely at low cost, that Let it be an issue.

Means for Solving the Problems and Effects of the Invention

In order to solve the above-mentioned problems, the present invention forms a vacuum vessel from four corner members and four side wall plates arranged between them, and this joint and the side wall plate adjoining each other are subjected to this vacuum. It is formed with the idea that it is formed by friction stir welding from both inside and outside of the container or from the outside.
That is, in the method for manufacturing a vacuum vessel according to the present invention (Claim 1) , four corner members are applied almost symmetrically by friction stir welding from the inside and outside of the vacuum vessel to both ends of a pair of side wall plates facing each other. Friction stirring for applying a different pair of side wall plates from the outside of the vacuum vessel between the first joining step for individually joining the inner and outer paired joints and the four corner members joined to both ends of the pair of side wall plates. And a second joining step for individually joining the inner and outer two or more joints formed by joining, in the first joining step, in the first joining step, the tip ends of the pair of inner and outer joints are In the second joining step, the inner and outer two or more joints formed between a pair of different side wall plates and the corner member are formed on the butting surface of the side wall plate and the corner member. The above-mentioned insertion is performed by an FSW tool having an inner joint portion friction-stir welded, an insertion plate inserted into one or a plurality of concave portions provided symmetrically outside the butting surfaces, and a stirring pin longer than the depth of the concave portion. It is characterized by comprising at least one of an intermediate joint portion and an outer joint portion formed by performing friction stir welding on almost the entire surface of the plate .

According to this , the vacuum container which is a cylindrical box can be easily formed by the corner members of the four corners, the pair of side wall plates arranged and joined between them, and the pair of different side wall plates . For this reason, for example, an aluminum alloy material can be easily used as a corner member by cutting or extrusion, and the side wall plate of each side can be formed of a rolled plate such as an aluminum alloy, so that it can be manufactured at low cost. .
In addition, the pair of side wall plates and the corner members positioned at both ends thereof are connected to a pair of different side wall plates and the corner members positioned at both ends by a joint portion such as an inner / outer pair by friction stir welding. Even if the processing equipment to rotate this cannot be inserted inside the box during assembly, the entire thickness in the inner and outer directions is dense due to the inner and outer joints by friction stir welding performed from the outside. It can be connected by a simple metal structure .

Further, the FSW tool that rotates from the outside of the box is pushed near the butting surface located inside the corner member and the different side wall plate, and the first-stage inner joint portion that has been subjected to friction stir welding in advance is provided. And then inserting an insertion plate having substantially the same cross-section into a recess having the formed inner joint portion on the bottom surface, and performing friction stir welding on substantially the entire surface of the insert plate, and the intermediate joint portion or this An outer joint is formed .
Therefore, it is possible to reliably provide a low-cost vacuum container having a plurality of joints having a thickness of several tens of millimeters, ensuring that the internal space is highly vacuumed and highly clean .

The pair of side walls different from the pair of side walls is a relative designation indicating only that the positions are different from each other. The material of the corner member or the side wall plate is not limited to aluminum or its alloy, but also includes titanium, its alloy, copper, its alloy, or stainless steel.
Further, as the corner member, a material obtained by cutting the rectangular metal material, an extrusion process, a drawing process, a hot or cold forged object, or the like is used.

  Further, the pair of inner and outer joints are a pair of joints partially overlapping each other from the inner side and the outer side, and at least one of the inner side and the outer side is a joint portion having two or more steps inside and outside, Also included are two pairs of joints, or a form in which one of the inside or outside is a joint of two or more stages inside and outside and the other is a joint of one stage.

Further, in the vacuum chamber, said at least one different pair of side wall plates, a pair of end plates to be joined at both ends between said corner member, or Ru frame-shaped plates der having an opening on the inside. Of this, according to the embodiment using a pair of end plates, respectively joined said end plates in the longitudinal direction of both ends of the pair of corner member opposed to the parallel opening communicating with the internal space of the vacuum chamber The part is formed.
Furthermore , according to the form using the frame-shaped plate, the opening portion of the frame-shaped plate joined between the pair of corner members communicates with the internal space of the vacuum vessel. Therefore, that Do can be a inexpensive vacuum container having an opening to be used for loading and unloading of a semiconductor device to be processed or treated with a vacuum.

Further, in the present invention, in the first joining step, prior to the formation of the inner joint part, temporary joining is partially performed by a friction stir welding method on a part of the abutting surface between the side wall plate and the corner member. In addition, a manufacturing method of a vacuum vessel for positioning the side wall plate and the corner member is also included (claim 2) .
The partial temporary joining is performed by an FSW tool having a small diameter and a short stirring pin. The part of the butting surface is at least one of a part in the thickness direction and a part in the longitudinal direction of the butting surface .

Furthermore, in the present invention, after forming the cylindrical box body composed of the pair of side wall plates, the different pair of side wall plates, and the four corner members frictionally joined between them, both ends of the box body are formed. the third has a bonding step, the vacuum container manufacturing method of joining individual pair of cover plates to the opening position, the two or more stages of the joint and out by friction stir welding from the outside of the vacuum container (claim 3 ) Is also included.
According to this, a pair of cover plates are individually joined to the opening portions located at both ends of the cylindrical box body from the outside by the joint portions of two or more steps inside and outside by friction stir welding. For this reason, the vacuum container which can maintain an internal space in a high vacuum and a highly clean state easily can be provided at low cost.

In addition, in the present invention, at least one of the different pair of side wall plates is a pair of end plates joined to both ends between the corner members, or a frame-shaped plate having an opening on the inside. The manufacturing method (Claim 4 ) is also included.
According to this, it is possible to reliably provide an inexpensive vacuum container having an opening used for taking in and out a semiconductor element or the like to be processed or processed under vacuum.

The best mode for carrying out the present invention will be described below.
FIG. 1 is a schematic perspective view of a vacuum vessel 1 manufactured according to the present invention, and FIG. 2 is a plan view thereof.
As shown in FIGS. 1 and 2, the vacuum container 1 includes a pair of side wall plates 2a and 2b facing each other, four corner members 3a to 3d joined to both ends thereof, and between the corner members 3a and 3b. A pair of end plates 4a, 4b and a back wall plate 6 (different pair of side wall plates) individually joined to the two side surfaces between the corner members 3c, 3d and where the pair of side wall plates 2a, 2b are not located; It has.
As shown in FIGS. 1 and 2, a rectangular opening 5 surrounded by the corner members 3a and 3b and the end plates 4a and 4b is located. In addition, an inner space 9 having a substantially rectangular parallelepiped is located on the inner side surrounded by the side walls 2a and 2b, the corner members 3a to 3d, the end plates 4a and 4b, and the back wall plate 6.

The pair of side wall plates 2a, 2b, end plates 4a, 4b, and back wall plate 6 are made of a rolled plate having a thickness of about 60 mm made of, for example, an Al—Mg-based aluminum alloy (for example, JIS: A5052). The corner members 3a to 3d are formed by cutting a square material having a substantially square cross section made of the same aluminum alloy as described above. The corner members 3a to 3d have a rounded surface R on the inner side and adjacent side walls (a pair of long sides). The thickness is the same as the thickness of the plates 2a and 2b.
As shown in FIGS. 1 and 2, the pair of side wall plates 2 a and 2 b and the corner members 3 a to 3 d at both ends thereof are a pair of inner and outer joints by friction stir welding performed almost symmetrically from the inner and outer directions of the container 1. It is joined by the parts w1 and w2. Further, the end plates 4a and 4b and the back wall plate 6 and the corner members 3a to 3d at both ends of the end plates 4a and 4b are respectively connected by outer and outer three-stage joint portions w3 to w5 by friction stir welding performed from the outside of the container 1. It is joined. As will be described later, a pair of end plates are individually joined to the openings 7a and 7b opened at the upper and lower ends (both ends) of the vacuum vessel 1 in the same manner as the above-described three-stage joining portions w3 to w5. Thus, the openings 7a and 7b may be closed.

According to the vacuum container 1 as described above, the corner members 3a to 3d at the four corners, the pair of side wall plates 2a and 2b, the end plates 4a and 4b, and the back wall plate 6 that are arranged and joined therebetween. Thus, the vacuum container 1 which is a cylindrical box is formed. For this reason, the aluminum alloy material can be easily used as the corner members 3a to 3d by cutting or extrusion, and the side wall plates 2a, 2b, etc. on each side can be formed by the aluminum alloy rolled plate, so that the cost can be reduced. It becomes.
Moreover, the pair of side wall plates 2a and 2b and the corner members 3a to 3d located at both ends thereof are connected to the end plates 4a and 4b and the back wall plate 6 by a pair of inner and outer joints w1 and w2 by friction stir welding. The corner members 3a to 3d located at both ends are connected by a dense metal structure in a solid state in the entire thickness in the inner and outer directions by the inner and outer three-stage joint portions w3 to w5 by friction stir welding performed from the outside. ing.
Accordingly, the vacuum container 1 has a plurality of joints w1, w2, w3 to w5 whose inner and outer thicknesses reach about 60 mm, and the internal space 9 can be reliably made high vacuum and highly clean, and can be made at a low cost. Can do.

Below, the manufacturing method of the said vacuum vessel 1 by this invention is demonstrated .
3-8 shows the 1st joining process in the manufacturing method of this invention .
FIG. 3 shows a first joining step for joining the corner members 3a (3c) and 3b (3d) to both ends (long sides) of the side wall plate 2a (2b). As shown in FIG. 3, the side wall plate 2a and the corner members 3a and 3b are abutted and restrained in advance at the abutting surface p.
As illustrated in FIG. 4 in which the one-dot chain line portion X in FIG. 3 is enlarged, the FSW tool 10 is prepared above the vicinity of the abutting surface p between the side wall plate 2a and the corner member 3a. The FSW tool 10 is made of, for example, tool steel, and as shown in FIG. 4, a cylindrical rotating body 12 and a cylindrical shape that hangs down from the vicinity of the center of the bottom surface 14 that is slightly curved and recessed upward. The stirring pin 16 is provided. On the peripheral surface of the stirring pin 16, uneven portions along the axial direction and radial direction such as screw threads and screw valleys (not shown) are engraved, and a plurality of fine irregularities are also engraved on the tip surface 18 thereof. You may do it.

As indicated by the arrows in FIG. 4, the stirring pin 16 of the FSW tool 10 that is mounted on a head such as a lathe (not shown) and rotates at high speed is pushed near the abutting surface p and moved along the abutting surface p.
At this time, the rotation speed of the FSW tool 10 is 300 to 1000 rpm, the feed rate is 0.05 to 500 mm / min, and the pushing force applied in the axial direction of the FSW tool 10 is about 10 kN to 30 kN.
Then, as shown in the vertical cross-sectional view of FIG. 5, the tip surface 18 of the stirring pin 16 moves to the left side in the drawing while reaching the vicinity of the middle in the thickness direction of the butting surface p.

As a result, as shown in FIGS. 5 and 6, both metal materials are heated by frictional heat with the agitating pin 16 along substantially the upper half of the abutting surface p between the side wall plate 2a and the corner member 3a. It is plasticized and fluidized (mass transfer) in the solid phase to form the frictionally stirred inner joint w1.
For example, when the thickness of the butting surface p is 60 mm, the rotating body 12 has a diameter of 30 mm, and the stirring pin 16 has a length of 30 mm and a diameter of 16 to 20 mm. As shown in FIGS. 4 and 5, the FSW tool 10 is used in an inclined state with an advance angle θ of about 2 to 3 degrees on the opposite side to the moving direction, but the advance angle θ is omitted and made vertical. May be.
Further, prior to the formation of the inner joint portion w1, an FSW tool having a small diameter and a short stirring pin on a part (at least one of the thickness direction and the longitudinal direction) of the abutting surface p of the side wall plate 2a and the corner member 3a. The temporary bonding to be used may be partially performed to position the side wall plate 2a and the corner member 3a.

Further, the side wall plate 2a (2b) and the corner members 3b (3c) and (3d) are friction stir welded in the same manner as described above, and an inner joint portion w1 is formed therebetween.
Next, as shown in FIG. 7, from the lower side of the abutting surface p between the side wall plate 2a and the corner member 3a, the same friction stir welding is performed using the FSW tool 10, thereby substantially lowering the abutting surface p. An outer joint w2 is formed along the half. The tip of the joint w2 overlaps with the tip of the inner joint w1. That is, the side wall plate 2a and the corner member 3a are joined via a pair of inner and outer joints w1 and w2. The friction stir welding is facilitated when the side wall plate 2a and the corner member 3a are turned upside down in FIG. 7 and the FSW tool 10 is used from above.
By the first joining process as described above, as shown in FIG. 8, the unit u1 (u2) in which the corner members 3a (3c) and 3b (3d) are joined to both ends of the side wall plate 2a (2b) is formed. .

FIGS. 9-17 shows the 2nd joining process in the manufacturing method of the said vacuum vessel 1. FIG.
As shown in FIG. 9, the end plates 4a and (4b) are placed between the corner members 3a and 3b of the units u1 and u2 formed in the first joining step, and the end plates 4c and 3d of the units u1 and u2 are placed between the corner members 3c and 3d. The wall plates 6 are arranged respectively. Note that the end plates 4a and (4b) are individually disposed between both ends of the corner members 3a and 3b in the longitudinal direction.
As illustrated in FIG. 10 in which the one-dot chain line portion Y in FIG. 9 is enlarged, between the rear wall plate 6 and the corner member 3d, the inner and outer two-stage recesses h1 are symmetrically formed on the outside in advance by cutting. h2 is provided, and the butting surface q of the back wall plate 6 and the corner member 3d is located closer to the inside thereof. The depths of the recesses h1 and h2 and the thickness of the abutting surface q are set to be approximately equal.
Therefore, as shown in FIG. 10, the unit u2 and the back wall plate 6 are restrained on a table (not shown) or the like in a state in which the abutting surface q between the former corner member 3d and the back wall plate 6 is formed. In addition, between the corner member 3c of the unit u2 and the end plates 4a and (4b), the concave portions h1 and h2 are formed on the outer side, and are constrained in a state where the abutting surface q is formed.

Next, the friction stir welding similar to the above is performed using the FSW tool 10 from the outside along the abutting surface q between the corner member 3d and the back wall plate 6. At this time, a jig for receiving the pushing force of the tool 10 (not shown) is set below the abutting surface q (inside the internal space).
As a result, as shown in FIG. 11, the inner joint portion w3 is formed along the abutting surface q. Prior to the formation of the joint w3, provisional joining using an FSW tool having a small diameter and a short stirring pin on a part (thickness direction and longitudinal direction) of the abutting surface p of the corner member 3d and the back wall plate 6 is used. The corner member 3d and the back wall plate 6 may be positioned by performing the above.
Next, as shown in FIG. 12, an insertion plate 20 having substantially the same cross section as this and made of the same aluminum alloy as described above is inserted and restrained in an inner recess h1 where the surface of the joint portion w3 is located on the bottom surface. To do. Note that the surface of the bonding portion w3 is polished flat in advance.

In this state, the stirring pin 16 of the FSW tool 10 that rotates at a high speed is pushed into the vicinity of the butting surface r between the left side of the insertion plate 20 and the back wall plate 6 that forms the left side of the recess h1 in FIG. Move along. At this time, the rotating body 12 of the FSW tool 10 is not prevented from rotating and moving by the outer concave portion h2. For example, when the thickness of the butting surface r is 20 mm, the diameter of the rotating body 12 is 27 mm, and the stirring pin 16 is 22 mm long × 12 to 16 mm in diameter.
As a result, as shown in FIG. 13, an intermediate joint w <b> 4 equivalent to the depth of the recess h <b> 1 is formed along the abutting surface r between the left side of the insertion plate 20 and the back wall plate 6. The tip (bottom) of the intermediate joint w4 is at a slightly deeper position than the bottom of the recess h1.

The FSW tool 10 moved to the front side in FIG. 13 makes a U-turn near the front end of the abutting surface r, moves to the right side of the insertion plate 20, and then moves along the longitudinal direction of the insertion plate 20 and to the back side in FIG. Move along. The FSW tool 10 that has reached the vicinity of the rear end of the insertion plate 20 due to such movement makes a U-turn and moves further to the right side of the insertion plate 20, and then along the longitudinal direction of the insertion plate 20 and along the front side of FIG. Move. The linear movement and the U-turn are alternately repeated a predetermined number of times to perform the zigzag movement in a plan view over almost the entire surface of the insertion plate 20.
As a result, as shown in FIG. 14, four intermediate joints w <b> 4 are formed along substantially the entire surface of the insertion plate 20. Among these, the right joining portion w4 in FIG. 14 is formed along the abutting surface r between the right side of the insertion plate 20 and the corner member 3d. At this time, the four intermediate joints w4 overlap each other on the side surface, and the two intermediate joints w4 closer to the center are formed to partially overlap the inner joint w3. Furthermore, the surface of the joint w4 exposed on the bottom surface of the recess h2 is polished flat. Incidentally, most of the insertion plate 20 becomes the four intermediate joints w4.

Next, as shown in FIG. 15, an insertion plate 22 made of the same aluminum alloy having the same cross-section as this is placed in the outer recess h <b> 2 having the surface of the four intermediate joints w <b> 4 on the bottom surface. Insert and restrain.
In this state, the stirring pin 16 of the FSW tool 10 that rotates at a high speed is pushed into the butting surface r in the vicinity of the butting surface s between the left side of the insertion plate 22 and the back wall plate 6 that forms the left side of the recess h2 in FIG. Move along.
Further, as shown in FIG. 16, U-turns near the front end and the rear end of the insertion plate 22 and linear movement along the longitudinal direction of the insertion plate 22 are performed on the FSW tool 10. A zigzag movement is performed in which the linear movement and the U-turn are alternately repeated a predetermined number of times.

  As a result, as shown in FIG. 17, seven outer joint portions w <b> 5 are formed over almost the entire surface of the insertion plate 22. Among these, the right end joining portion w5 in FIG. 17 is formed along the abutting surface s between the right side of the insertion plate 22 and the corner member 3d. At this time, the seven outer joints w5 also overlap each other on the side surface, and the five outer joints w5 closer to the center are formed so as to partially overlap the intermediate joint w4. The surface of each joint portion w5 is flatly polished to be flush with the outer side surfaces of the back wall plate 6 and the corner member 3d. As a result, the corner member 3d and the back wall plate 6 of the unit u2 are joined via the inner and outer three-stage joining portions w3, w4, and w5 that are sequentially formed from the outside. Incidentally, most of the insertion plate 22 becomes the seven inner joints w5.

Further, a single inner joint w1 is formed along the abutting surface q between the corner member 3b of the unit u2 and the end plates 4a and 4b, and is inserted into the recesses h1 and h2 formed outside thereof. Four intermediate joints w4 and seven outer joints w5 are similarly formed along substantially the entire surface of the insertion plates 20 and 22.
Further, along the abutting surface q between the corner members 3a, 3c and the end plates 4a, 4b or the back wall plate 6 of the unit u1, the same inner and outer three-stage joints w3, w4, w5 are the same. Formed.
As a result, as shown in FIG. 18, the pair of opposing side walls 2a and 2b and the corner members 3a to 3d are joined via a pair of inner and outer joints w1 and w2, and both ends (between the corner members 3a and 3b) The end plates 4a and 4b are joined to the upper and lower ends via the inner and outer three-stage joining portions w3, w4 and w5 formed from the outside, and the back wall plate 6 is similar between the corner members 3c and 3d. It joins via joining part w3, w4, w5.

Thus, the vacuum container 1 shown in FIGS. 1 and 2 has a substantially rectangular parallelepiped internal space 9 inside and a rectangular opening 5 between the end plates 4a and 4b and the corner members 3a and 3b. Can be obtained.
Further, as shown in FIG. 19, the side wall plates 2a and 2b, the end plates 4a and 4b, the corner members 3a to 3d, and the openings 7a (7b) at the upper and lower ends of the rear wall plate 6 are substantially similar to this. You may perform the 3rd joining process obstruct | occluded with the cover plate 24 which consists of an aluminum alloy similar to the above in the form.

That is, as shown on the right side of FIG. 19, the end face of the side wall plates 2a, 2b and the like facing the four sides of the lid plate 24 having rounded corners in advance as shown on the right side of FIG. h2 is formed in advance. Next, using the FSW tool 10 in the same manner as described above and inserting the insertion plates 20 and 22 into the recesses h1 and h2, as shown on the left side of FIG. The joint portion w5 and the seven outer joint portions w5 are formed in the same manner as described above.
As a result, the upper and lower openings 7 a and 7 b are closed by the cover plate 24, and the internal space 9 is in communication with the outside only through the opening 5.

According to the manufacturing method of the vacuum vessel 1 of the present invention as described above, the side wall plates 2a and 2b, the end plates 4a and 4b, and the back wall plate 6 made of thick rolled plates, and relatively few cutting processes, etc. Can be manufactured easily and at low cost by the corner members 3a to 3d that can be formed. Moreover, a pair of inner and outer joints w1 and w2 by friction stir welding from both inside and outside of the vacuum vessel 1 and the inside and outside 3 by friction stir welding sequentially applied from the outside of the vacuum vessel 1 are provided between the above-described constituent members. The steps can be easily and densely joined by the step joining portions w3 to w5. Therefore, it is possible to reliably provide the vacuum container 1 that can easily maintain the internal space 9 in a high vacuum or a high clean state.
The opening 5 can be opened and closed by an airtight door (not shown).

FIG. 20 is a perspective view showing an outline of different types of vacuum vessels 1a that can be manufactured according to the present invention .
As shown in FIG. 20, in the vacuum vessel 1a, a pair of opposing side walls 2a, 2b and corner members 3a-3d are joined in the same manner as described above via a pair of inner and outer joints w1, w2, and the corner member 3c, The back wall plate 6 is joined in the same manner as described above via the joint portions w3, w4, and w5 similar to the above.
Between the corner members 3a and 3b, as shown in FIG. 20, a frame-shaped plate 26 which is rectangular in front view and has a rectangular opening 28 formed in advance on the inside is the same as described above, and has three inner and outer steps which are long in the vertical direction. It joins similarly to the above via joining part w3, w4, w5. By using this frame-shaped plate 26, the number of steps of the friction stir welding (second joining step) is slightly increased, but the restraining work performed before that becomes easy. Moreover, since the dimensional accuracy of the opening part 28 is also high, the airtightness of the internal space 9 is further improved.

The present invention is not limited to the embodiments described above.
For example, in the manufacturing method, the back wall plate 6 and the corner members 3c and 3d are first joined via the pair of inner and outer joints w1 and w2 in the first joining step, and the end plates 4a and 4b or the frame are joined. The shape plate 26 and the corner members 3a and 3b may be joined together via a pair of inner and outer joints w1 and w2 to form the units u1 and u2. In this case, the side wall plates 2a and 2b and the corner members 3a to 3d are joined through inner and outer three-stage joining portions w3, w4, and w5 that are sequentially formed from the outside in the second joining step. Ie upon the present invention, the a pair of side walls different from the pair of side walls, a relative called pointing only positions are different from each other.

Moreover, the intermediate | middle junction part w4 formed at a said 2nd joining process should just be at least 2 or more at least, and the outer side junction part w5 should be at least 4 or more.
Furthermore, the rounded surface R inside the corner members 3 a to 3 d may be formed by cutting after the vacuum vessel 1 is manufactured. Alternatively, instead of the rounded surface R, an inclined chamfer or a staircase shape portion may be located on the inner surface.
Further, the agitation pin 16 of the FSW tool 10 may have a substantially conical shape with a taper that is thicker toward the proximal end on the rotating body 12 side and narrower toward the distal end.
The present invention can be modified as appropriate without departing from the spirit of the present invention.

The perspective view which shows the outline of the vacuum vessel obtained by this invention. The schematic plan view of the said vacuum vessel. Schematic which shows the 1st joining process of the manufacturing method of this invention which obtains the said vacuum vessel. The enlarged view of the dashed-dotted line part X in FIG. Schematic which shows the 1st joining process following FIG. Schematic which shows the 1st joining process following FIG. 4 in an angle different from FIG. Schematic which shows the 1st joining process following FIG. Schematic which shows the unit obtained by the 1st joining process. Schematic which shows the 2nd joining process of the manufacturing method of this invention which obtains the said vacuum vessel. The enlarged view of the dashed-dotted line part Y in FIG. Schematic which shows the 2nd joining process following FIG. Schematic which shows the 2nd joining process following FIG. Schematic which shows the 2nd joining process following FIG. Schematic which shows the 2nd joining process following FIG. Schematic which shows the 2nd joining process following FIG. Schematic which shows the 2nd joining process following FIG. Schematic which shows the 2nd joining process following FIG. The top view which shows the vacuum vessel obtained by the manufacturing method of this invention. Schematic which shows the 3rd joining process of the manufacturing method of this invention which obtains the said vacuum vessel. The perspective view which shows the outline of the vacuum vessel of a different form.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1a ... Vacuum container 2a, 2b ... Side wall plate 3a-3d ... Corner member 4a, 4b ... End plate (different side wall)
6 …………… Back wall board (different side walls)
7a, 7b ... opening
10 ………… FSW tools 20, 22… Insertion plate 24 ………… Lid plate 26 ………… Frame shape plate (different side walls)
28 ............ Opening part of frame-shaped plate w1, w2 ... Pair of inner and outer joints w3 ………… Inner joint part w4 ………… Intermediate joint part w5 ………… Outer joint part q …………… Butting surface h1, h2 ... concave

Claims (4)

A first joining step in which four corner members are substantially symmetrically applied to both ends of a pair of side wall plates facing each other by friction stir welding from the inside and outside of the vacuum vessel, and individually joined by a pair of inner and outer joints;
A second pair of inner and outer joints formed by friction stir welding in which a different pair of side wall plates are applied from the outside of the vacuum vessel between the four corner members joined to both ends of the pair of side wall plates. A method of manufacturing a vacuum vessel including two joining steps,
In the first joining step, the tip ends of the pair of inner and outer joints overlap each other,
In the second joining step, the inner and outer two or more joint portions formed between a pair of different side wall plates and the corner member are friction stir welded along the abutting surfaces of the side wall plates and the corner member. Friction stir welding to almost the entire surface of the insertion plate by an FSW tool having a joining portion, an insertion plate inserted symmetrically on one or more recesses provided outside the butting surface, and an agitation pin longer than the depth of the recess Consisting of at least one of an intermediate joint and an outer joint formed by applying
A manufacturing method of a vacuum vessel characterized by the above. In the first joining step, prior to the formation of the inner joining portion, temporary joining is partially performed by a friction stir welding method on a part of the abutting surface between the sidewall plate and the corner member, and the sidewall plate and the corner are joined. Positioning the member,
The manufacturing method of the vacuum container of Claim 1 characterized by the above-mentioned. After forming the cylindrical box body composed of the pair of side wall plates, the different pair of side wall plates, and the four corner members frictionally joined between them, a pair is formed at the openings located at both ends of the box body. A third joining step in which the end plates are individually joined from the outside of the vacuum vessel by joints of two or more stages inside and outside by friction stir welding .
The manufacturing method of the vacuum vessel of Claim 1 or 2 characterized by the above-mentioned . At least one of the different pair of side wall plates is a pair of end plates joined to both ends between the corner members, or a frame-shaped plate having an opening on the inside .
The manufacturing method of the vacuum vessel as described in any one of Claims 1-3 characterized by the above-mentioned.

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