JP2839454B2 - Method of manufacturing brazed panel having curved surface - 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 panel having a curved shape by brazing a plurality of constituent members, and more particularly to a method for manufacturing a panel having a curved surface with respect to dimensional accuracy and brazing strength. Manufacturability or cost related to manufacturing equipment, the number of steps, work accuracy, etc. can be dramatically improved, and a brazed panel having a curved surface can be industrially mass-produced. It relates to a manufacturing method.

[0002]

2. Description of the Related Art Conventionally, as one type of panel used for various structures, various types of brazing in which a plurality of constituent members are brazed for the purpose of meeting required strength, weight, shape, and size. Panels are known. In particular, in recent years, as described in Japanese Patent Application Laid-Open No. 5-38359 and the like, two upper and lower face plates are overlapped on both sides of a frame having a predetermined shape, and a honeycomb-shaped core is provided in a region of the frame. A sandwich panel has been proposed, which is arranged and sandwiched between two face plates and assembled by brazing the frame body, face plate and honeycomb core, and has advantages in strength while securing light weight. Therefore, application to various fields such as a car body, a hull panel, and a building panel is expected.

[0003] When a brazing panel such as a honeycomb sandwich panel is used as a structural material or the like, a panel shape having a curved surface may be required. In order to obtain a brazed panel having a curved surface shape, generally, (A) a curved surface brazing method for brazing and joining components that have been formed in advance, and (B) a component formed in a flat plate shape. There are two types of manufacturing methods, a bending method of bending after attaching and joining. However, it is extremely difficult to obtain satisfactory quality, productivity, or cost by any of these methods. At present, it cannot be expected to spread as an industrial product because mass production is impossible.

In order to facilitate understanding of the present invention, a honeycomb sandwich panel made of an aluminum alloy has a (A) curved surface brazing method and (B) as a conventional technique.
Specific manufacturing methods and problems in the bending method are described below.

(A) Curved surface brazing method In the curved surface brazing method, first, a frame body is manufactured by combining extruded shapes that have been bent in advance and joining them by welding or the like, and a special curved body as a whole is bent in the frame body. Core material (honeycomb body, fin body, shaped material, etc.) having various shapes is arranged, and the frame body and the core material are sandwiched between two upper and lower face plates that have been bent into a curved surface in advance, and then sandwiched. This is performed by heating and brazing in a furnace while the body is sandwiched between jigs having a curved surface. However, such a curved surface brazing method has the following problems. (1) In order to stably obtain the joining quality between the frame body and the face plate, it is necessary to secure the curved surface shape of the frame body with high precision, and the labor, time, and time required for bending and machining the frame body are required. If the cost is high and the demands on the joining quality are severe, it is necessary to machine the upper and lower surfaces of the frame after bending to ensure the accuracy, which is enormous. (2) During heating for brazing,
In order to avoid the deformation caused by the thermal expansion difference between the panel and the jig while avoiding the deformation due to the thermal stress, it is necessary to finely adjust the clamping pressure so that the panel and the jig fit together. Is difficult and lacks stability in the brazing condition. (3)
Assembling a curved frame body by combining and welding bent profile members is more difficult than assembling a planar frame body, and requires a plurality of frame body supports corresponding to various curvatures. . (4) Since each panel component such as the frame and the face plate needs to be bent in separate steps, the number of working steps is large, the cost is high, and the probability of occurrence of scratches on the members is high. (5) In order to assemble a curved core material by combining a large number of corrugated molding materials and the like, special processing is required, and it is difficult to set the curved core material in a frame.

(B) Bending method The bending method is to form a flat panel formed by assembling a frame body, a core material, and a face plate each having a planar shape and brazing them together at room temperature to obtain a desired curved panel. For example, (a) 2 arranged in parallel
A three-roll bending method of bending a flat panel between upper and lower rollers through a flat panel between a lower roller and one upper roller arranged in parallel at an intermediate portion between the lower rollers; (B) an iso-moment method in which a bending moment is applied to both ends of the flat panel to perform bending processing;
(C) There is a press bending method in which a flat panel is pressed and bent by using an upper and lower press die having a press surface corresponding to a target curved surface. However, such a bending method has the following problems. (1) In the process of bending, excessive stress is applied to the face plate and the core material which are brazed and joined to each other, so that deformation or buckling, such as dents or bending, is likely to occur, and the bendable radius of curvature is considerable. Is limited to (2) When a flat panel to which each component is brazed and joined is bent in one direction at room temperature, it tends to bend in a direction orthogonal to the opposite direction to form a saddle type, and it is difficult to correct after bending. (3) Due to its structure, the sandwich panel has high rigidity and is hard to bend, and the unevenness of the frame and the core is liable to be uneven. difficult. (4) The bending process needs to be carefully and slowly performed, and a press correction is also required to ensure accuracy, so that it is not suitable for mass production.

[0007]

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to prevent the occurrence of partial brazing defects, deformation, etc. It is an object of the present invention to provide a method of manufacturing a brazed panel which can obtain a curved surface with high precision and has excellent manufacturability.

[0008]

A feature of the present invention to solve the problem is a method of manufacturing a panel having a curved shape by brazing a plurality of constituent members. The plurality of components, a frame,
Two upper and lower face plates superposed on both sides of the frame,
Hani sandwiched between the two face plates in the body region
And a cam-shaped core.
A step of obtaining a flat panel having a flat plate shape, which is a sandwich panel having a hollow structure, by combining materials with each other while allowing relative displacement; and (b) adapting the flat panel to a desired curved shape. (C) heating the flat panel set between the upper and lower press jigs to a softening temperature and applying a pressing force between the upper and lower press jigs; (D) deforming the flat panel along at least one of the pressing surfaces of the upper and lower press jigs into a desired curved shape, and (d) deforming the flat panel by pressing between the upper and lower press jigs. And brazing the contact portions of the plurality of constituent members to each other under pressure by the upper and lower press jigs.

The brazing material for joining the abutting portions of the plurality of constituent members may be, for example, interposed between the constituent members when the flat panel is assembled by the constituent members, or the brazing material may be adhered to the surface. It is given to the brazing joint by an appropriate method, for example, by forming a panel component such as a face plate with the member thus formed.

In a preferred first aspect of the present invention, the pressing force applied between the upper and lower press jigs is:
It said et contain altered as with the deformation of the flat panel.

[0011] Furthermore, in a preferred second aspect of the present invention, plastic deformation of the flat panel does not occur until the flat panel is heated to a softening temperature.
The pressure applied between the upper and lower press jigs is adjusted.

Further, the melting and joining of the brazing material can be performed during the progress of the deformation of the panel or after the completion of the deformation of the panel, or both during the progress of the deformation and after the completion of the deformation. In the third aspect, after the deformation of the flat panel by the pressing between the upper and lower press jigs is completed, the brazing material is melted at the abutting portions of the plurality of components constituting the flat panel. The melting of the brazing material after the completion of the deformation of the flat panel is realized, for example, by adjusting the melting start temperature of the brazing material according to the material of the brazing material and appropriately setting the pressing force. obtain.

In a preferred fourth aspect of the present invention, the heating of the flat panel is performed in a vacuum or an inert gas.

Further, in a preferred fifth aspect of the present invention, a pressing force is applied between the upper and lower press jigs by the weight of the upper press jig.

In a preferred sixth aspect of the present invention, the plurality of constituent members are brazed to each other under pressure by the upper and lower press jigs and then pressurized by the upper and lower press jigs. It is made to cool as it is.

[0016]

In a preferred eighth aspect of the present invention, a honeycomb core in the sandwich panel is formed by arranging a plurality of corrugated moldings in parallel, and each of the corrugated moldings is formed by a corrugated molding. It extends substantially orthogonally to the bending direction. The bending direction refers to a direction perpendicular to the central axis of curvature of the curved surface of the target brazing panel on the panel surface.

Further, in a preferred ninth aspect of the present invention, a honeycomb core in the sandwich panel is formed by arranging a plurality of corrugated moldings in parallel, and each of the corrugated moldings is formed. Are disposed so as to extend substantially in the bending direction.

In a preferred tenth aspect of the present invention, the flat panel is formed into a curved shape while permitting relative displacement of the plurality of corrugated moldings arranged in parallel in the region of the frame. It is made to be deformed.

Further, in a preferred eleventh aspect of the present invention, the frame constituting the sandwich panel is formed so as to extend in the direction of bending from the product dimensions of the intended brazing panel, and A notch groove extending inward from the extension end of the middle portion of the face plate in the overlapping direction is provided for the extension portion of the frame. In addition, the extension part is cut after completion of bending and brazing, whereby a brazing panel having a desired shape can be obtained.

Further, in a preferred twelfth aspect of the present invention, a spacer is mounted on the notch groove formed in the extension of the frame in the bending direction, and the spacer is sandwiched between the notch grooves. Under the state, deformation processing is performed by an upper and lower press jig. As the spacer, for example, a brazing material, a member clad with the brazing material, or a member other than the brazing material, such as metal or glass, is suitably used.

In a thirteenth preferred embodiment of the present invention, the frame constituting the sandwich panel is extended in a bending direction from a product size of a target brazing panel, and the frame is formed. With respect to at least one of the surfaces in the superimposing direction of the face plate in the extended portion of
The taper is applied in a direction that tapers toward the front end portion in the extension direction.

[0023]

According to the method of the present invention, since the constituent member is deformed at the softening temperature to have the desired curved shape, the pressing force is sufficiently smaller than when deformed at normal temperature. Therefore, it is possible to bend without generating a large internal stress, and at the time of bending, since each component is deformable independently of each other and is bent without receiving unnecessary stress on each other, dents and Wrinkling, buckling, breakage, and the like are prevented, and accurate bending can be performed. Special
According to the method of the present invention, conventionally, a curved surface shape can be obtained.
The sandwich panel with a hollow structure, which was extremely difficult,
Advantageously bendable, and thereby aluminum
A hollow sandwich panel made of
Widely used for various structural materials such as road vehicles, ships, and architectural designs.
It becomes possible.

Moreover, in the method of the present invention, since the constituent members are combined and bent at the same time, a difference in the curved shape between the constituent members is prevented, and the gap at the joint surface is kept sufficiently small. Therefore, the bonding failure rate is improved, and a brazing panel with high bonding quality can be stably obtained.

According to the first preferred embodiment of the present invention, for example, even when the deformed portion of the flat panel moves and the distance between the points of application of the pressing force changes, the moment applied to the panel is kept substantially constant. It is possible to control such that the panel is maintained, whereby the panel can be bent more smoothly and the occurrence of defects such as buckling can be suppressed more effectively.

Further, according to a preferred second aspect of the present invention, it is possible to prevent a large internal stress or the like generated in the component by applying plastic deformation to the component at a temperature not reaching the softening region. This can prevent unnecessary deformation such as dents, wrinkles, and buckling of the constituent members. The limit moment Me at which plastic deformation occurs in the constituent members is expressed by the following equation. Me = Zm · σe (Zm: sum of section modulus of member, σe: yield stress of member at that temperature)

Further, according to the third preferred embodiment of the present invention, since the brazing material starts to be melted after the completion of the bending process, the outflow of the brazing material to a portion other than the joint surface is minimized. There is an advantage that it can be securely joined.

Further, according to the fourth preferred embodiment of the present invention, problems such as deterioration, corrosion, and the like during heating of the constituent members and the brazing material can be advantageously avoided.

Further, according to the fifth preferred embodiment of the present invention, since a special pressurizing device such as a hydraulic device is not required, the equipment can be simplified.

Further, according to the sixth preferred embodiment of the present invention, since the brazing connection is completed in a state where the constituent members are bent and held in a desired curved state, the displacement of the constituent members and the like are completed. Can be advantageously prevented, and the processing accuracy can be further improved.

[0031]

According to the eighth preferred embodiment of the present invention, it is possible to easily deform the honeycomb-shaped core into a desired curved shape with a relatively small pressing force during the deformation processing into a curved shape. Thus, the stress generated in each corrugated molding material constituting the core is also reduced.

Furthermore, according to a ninth preferred embodiment of the present invention, even when the core height (dimension in the thickness direction of the panel) is high or the radius of curvature of the panel is small, the honeycomb-shaped core is entirely formed. It can be bent almost uniformly, and the quality stability can be improved.

Further, according to the tenth preferred embodiment of the present invention, at the time of deformation processing into a curved shape, the generation of internal stress in the honeycomb core is reduced, and good bending workability can be exhibited.

Further, according to a preferred eleventh aspect of the present invention, a large bending moment can be applied to both ends in the bending direction of the sandwich panel by the extension portion, and the bending strength of the extension portion itself can be improved. Since it is lowered by the notch groove, the so-called "catch" phenomenon in which the pressing surface of the press jig is lifted from the panel surface on the panel convex surface side by the extension portion is prevented,
The pressing force of the upper and lower press jigs can be advantageously applied to the entire panel, so that the bending accuracy at both ends in the bending direction is particularly advantageous even for a panel having a small radius of curvature or a thick panel. In addition to the above, it is possible to prevent the brazing joint failure due to the “splice”.

Furthermore, according to a preferred twelfth aspect of the present invention, the bending strength of the extended portion is ensured until the spacer is melted or crushed, and the distal end of the extended portion is attached to the press jig. Since it is in contact with the pressure surface and becomes the point of application of the pressing force, an effective moment is exerted on the panel during panel bending performed at a temperature equal to or lower than the melting temperature of the brazing material, and favorable bending can be performed, and Since the extended portion is deformed by the action of the notch groove after the spacer is melted or crushed after the bending process is advanced, the "split" at the end stage of the bending process is also prevented, thereby improving the brazing joint property. Be demonstrated.

According to a thirteenth aspect of the present invention, a large bending moment can be applied to both ends of the sandwich panel in the bending direction by the extension portion, and the taper attached to the extension portion allows the bending moment to act on both ends. Since the bending strength of the extension portion itself is also low, the same effect as the preferred ninth aspect of the present invention can be exerted. In particular, if the projecting side surface of the panel in the extension portion is tapered, the extension portion is shaped along the pressing surface of the press jig with a small amount of bending, so that "split" can be more effectively prevented.

[0038]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

First, FIG. 1 shows a specific example of a brazing panel having a curved surface manufactured by the method of the present invention.
A brazed aluminum honeycomb panel 10 having a substantially rectangular shape as a whole and curved in the direction of one opposite side is shown. The honeycomb panel 10 includes three curved frame members 12 arranged in parallel at a predetermined distance from each other,
Straight frame material 1 for connecting two curved frame materials 12 at both ends
4 as a whole, the frame 16 is assembled in a substantially “day” shape, and the honeycomb cores 18 having a substantially honeycomb shape are housed and arranged in the respective spaces partitioned by the frame 16. In addition, the upper plate 20 and the lower plate 22 are overlapped so as to sandwich the frame 16 and the honeycomb cores 18 from both sides, and are integrally brazed.

The honeycomb panel 1 having such a structure is as follows.
In order to obtain 0, first, as shown in FIG. 2, the frame 16, the honeycomb cores 18, 18 and the upper and lower plates 20, 22 as the components of the panel as described above are combined to form a flat panel 24. To form Here, the frame body 16, the honeycomb core 18, the upper and lower face plates 2
Both 0 and 22 are not curved, and the same components as those of the conventional honeycomb panel having a flat plate shape are employed.

That is, for example, the frame 16 is formed by cutting an aluminum alloy extruded shape having a mouth-shaped hollow cross section to an appropriate length, and combining them in a Japanese character shape and partially fixing the shape by welding or the like. Formed. In addition, each shape member combined in the shape of a letter is not joined in advance, but in the final step of brazing and joining the constituent members to each other later, and is simultaneously joined by brazing and integrally joined in a letter shape. It is also possible. Further, as shown in FIG. 3, the honeycomb core 18 is, for example, corrugated into a continuous semi-hexagonal shape made of a strip-shaped aluminum material or a brazing sheet in which a brazing material is clad on both surfaces or one surface of an aluminum material. A plurality of the honeycomb forming materials 26 are used, and the honeycomb forming materials 26 are formed side by side so as to form hexagonal cells as a whole. In the present embodiment, the respective honeycomb forming materials 26 constituting the honeycomb core 18 are arranged in the space partitioned by the frame 16 without being brazed and joined to each other. It is also possible to incorporate the honeycomb core 18 which has been integrally joined by brazing in advance into the space of the frame body 16. Further, in the present embodiment, as shown in FIG.
The length direction is the direction in which the panel is to be bent (x direction in the figure)
So that the honeycomb core 18 is in a direction orthogonal to
Is formed. Furthermore, the height of the honeycomb core 18 is set to be substantially the same as the height of the frame 16, and
The outer shape of the honeycomb core 18 is set to be substantially the same as the space shape partitioned by the frame 16. Further, the upper and lower panels 2
Each of the reference numerals 0 and 22 is formed of a brazing sheet made of an aluminum alloy in which one surface is clad with a brazing material and has a rectangular flat plate shape corresponding to the outer shape of the frame body 16, and the honeycomb core 18 is incorporated therein. On both sides of the frame 16, the brazing material is overlapped with the surface on the side clad with the brazing material inside. At this time, in order to prevent the face plates 20 and 22 from being displaced from the frame 16 during a heating deformation step described later, the face plates 20 and 22 are temporarily attached to the frame 16 by welding at an appropriate number of points. You may stop it. This temporary fixing is performed so as not to hinder the free deformation of each member. For example, spot welding of the center portions of both sides of the upper and lower face plates 20 and 22 extending in the bending direction to the frame 16 is performed. Is temporarily stopped by

Next, as shown in FIG. 4, the flat panel 24 formed by combining the frame body 16, the honeycomb cores 18, 18 and the upper and lower face plates 20, 22 without bonding them together is bent as shown in FIG. Device 28
Set to. The bending apparatus 28 includes an upper press jig 32 having a concave pressing surface 30 corresponding to a target curved panel convex surface shape, and a convex pressing surface 34 corresponding to a target curved panel concave surface shape. Press jig 3 having
6 is included. The lower press jig 36
Are placed on a transport tray 38 and a pressing mass 40 is placed on the upper press jig 32. Then, as shown, the lower press jig 36
The flat panel 24 is placed on the flat panel 24, and the upper press jig 32 is further placed on the flat panel 24, so that the flat panel 2 is located between the pressing surfaces 30 and 34 of the upper and lower press jigs 32 and 36.
4 is installed. In addition, heat-resistant buffer sheets 42 and 44 are provided between the pressing surfaces 30 and 34 and the flat panel 24.
Install if necessary.

Then, as shown in FIG. 5, upper and lower press jigs 32 and 36 on which the flat panel 24 is set.
Is placed in a heating furnace 48 provided with a heater 46, and if necessary, the inside of the furnace is evacuated to a vacuum or an inert gas atmosphere, and then heating is started. Note that, before the heating is started, the frame 16 is prevented from being plastically deformed in the flat panel 24.
The weight of the pressurized mass 40 is set in consideration of the strength of the pressurized mass 40.

Thus, the flat panel 24 is heated by heating.
6 gradually rises and exceeds the softening temperature, the strength of the flat panel 24 (the bending strength exerted mainly by the frame 16) rapidly decreases, and as a result, as shown in FIG. As described above, the flat panel 24 starts to deform slowly under a constant pressing force by the upper press jig 32 and the pressing mass 40. Here, the flat panel 24
The center portion of the lower press jig 36 is in contact with the center of the convex pressing surface 34, while both ends in the bending direction (x direction in FIG. 3) Since the pressing force is applied to the center portion and both end portions of the flat panel 24 by being brought into contact with both side portions of the pressing surface 30, the deformation of the flat panel 24 is firstly performed at the center portion where the bending moment becomes maximum ( Starting from the point of contact with the lower press jig 36)
Its deformation speed once increases with increasing temperature,
Since the contact area with the lower press jig 36 begins to expand toward both sides of the panel, the contact area becomes substantially constant, and thereafter, the bending process is slowly performed with a decrease in the bending moment due to the enlargement of the contact point with the lower press jig 36. Will progress.

As a result, as shown in FIG.
The flat panel 24 is provided with upper and lower press jigs 32,
The flat panel 24 is bent along the pressing surfaces 30 and 34, and both ends of the flat panel 24 in the bending direction are brought into contact with the convex pressing surface 34 of the lower press jig 36, thereby forming a desired curved shape. It is molded and the bending process is completed. The flat panel 2
At the stage where both ends in the bending direction of 4 are substantially in contact with the convex pressing surface 34 of the lower press jig 36, the bending moment acting on the flat panel 24 becomes extremely small, so that the flat panel 24 is hardly bent. Since the yield strength of the flat panel 24 near the brazing temperature is extremely small, as long as the sectional modulus of the flat panel 24 (mainly the frame body 16) is not larger than a certain value or is smaller than a certain value, The end of the flat panel 24 can be bent along the pressing surfaces 30 and 34 of the upper and lower press jigs 36.

Thereafter, the heating temperature of the flat panel 24 is further increased, and the honeycomb forming material 26 constituting the honeycomb core 18 and the brazing material clad on the upper and lower face plates 20 and 22 are heated and melted. The melted brazing material is allowed to flow between the abutting portions of the first and second members to perform brazing. At this time, even if the honeycomb forming material 26 is a single plate (for example, A6954 material or the like) having no brazing material,
Since the brazing material clad on the face plates 20 and 22 melts and flows into the gaps between the honeycomb forming materials 26, the honeycomb forming materials 26 are also joined to each other. As a result, each honeycomb forming material 26 is brazed to integrally form the honeycomb core 18, and the honeycomb core 18 is brazed to the upper and lower face plates 20 and 22 and the frame body 16. 22 is the honeycomb core 18 and the frame 16
Brazed. Subsequently, the flat panel brazed in this manner is taken out of the heating furnace 48 while being sandwiched by applying a pressing force between the upper and lower press jigs 32 and 36, and is cooled by a cooling facility to be brazed. The joining process is completed. The curved panel 10 thus obtained can be naturally cooled, but is desirably rapidly cooled from the viewpoint of improving the strength by quenching and improving the manufacturing cycle.

After cooling, the upper and lower press jigs 32, 3
By opening the panel 6 and taking out the panel, it is possible to obtain the desired curved honeycomb panel 10 as shown in FIG.

According to such a method, the honeycomb panel 1
When manufacturing No. 0, since the bending work which was conventionally performed at normal temperature is performed hot, (1) the work hardening of the material is prevented, and there is a problem in the bending work at normal temperature. And (2) the heating temperature of the flat panel 24, which suppresses the occurrence of "wrinkles" and "buckling" due to the generation of unnecessary stress toward portions having a small amount of deformation, such as both side portions of the frame 16. By gradually increasing the bending, the bending proceeds smoothly and smoothly with the continuous decrease in the strength of the material,
Bending always proceeds with almost optimal pressure. (3)
As long as the temperature of the flat panel 24 is uniform as a whole, it proceeds in order from the central portion of the panel where the bending moment is maximized to both side portions (in order, the contact of the lower press jig 36 with the convex pressing surface 34 becomes weaker). Will be completed)
As the bending progresses, the fulcrum (the contact point to the lower press jig 36 of the flat panel 24) moves toward the end, so that a large pressing force is prevented from acting only on the central portion to the end. Thus, effects such as prevention of buckling at the central portion are exhibited.

Further, in the manufacturing method as described above, the components 16, 18 and 2 are formed at the time of bending the flat panel 24.
0 and 22 are not fixed to each other and can be freely deformed, and each component is independently subjected to bending stress. (1) The thin face plates 20 and 22 and the thin honeycomb forming material 26 Each of the formed honeycomb cores 18 is easily deformed, and most of the bending stress is received by the frame body 16, so that the sum of the section coefficients is significantly smaller than that in a case where the respective constituent members are joined, and (2) Unnecessary stress generation due to buffer between components during bending is prevented, and bending proceeds smoothly. And
Effects such as completion of bending into an ideal shape can be obtained.

Furthermore, in the manufacturing method of the present embodiment, the same jig is used at substantially the same temperature for bending and brazing, so that the bending jig and the brazing jig are used. In addition to avoiding brazing defects and a decrease in dimensional accuracy due to differences in the dimensional accuracy of the tools, the occurrence of problems due to differences in the coefficient of thermal expansion is also prevented. That is, in the present embodiment, during the heating, the bending process on the flat panel 24 is performed as follows.
It progresses in accordance with the curvature of the pressing surfaces 30, 34 of the upper and lower press jigs 32, 36, and even if the curvature radius of the flat panel 24 becomes larger than the curvature radius of the pressing surface 34 due to the subsequent thermal expansion (this embodiment) Unless a lower press jig made of a material having a larger thermal expansion coefficient than that of an aluminum alloy is used, the radius of curvature of the flat panel 24 tends to be larger than that of the pressing surface 34). From the central part of the body to the side parts. Note that this correction is performed on the flat panel 2
It is presumed that the lower press jig 4 is proceeding simultaneously with the enlargement of the contact area of the lower press jig 36 with the pressing surface 34.

Further, in the manufacturing method of this embodiment,
It is manufactured using the same components as the flat panel, and since the hot bending process is performed during the heating process for brazing, the same preparation process as the conventional flat panel manufacturing process and By performing the heating step, the honeycomb panel 10 having the target curved surface can be obtained. (1) The honeycomb panel 10 having the curved surface with substantially the same operation personnel and work efficiency as in the production of the flat panel can be obtained. (2) As long as heating and pressurization are performed to perform sound brazing, bending is automatically performed by the heating furnace 4.
8 and does not require any special skills or the like of the worker relating to the bending process, and does not require any special management. (3) The "necessary for manufacturing the curved panel during the manufacturing process of the flat panel" The "bending process" is rationally incorporated, and an increase in the load on the process is suppressed as much as possible, and an effect such as an excellent economic effect is exhibited.

In the manufacturing method according to the present embodiment, the manufacturing equipment requires a press jig 3 which is used for both curved surface forming and brazing as compared with flat panel manufacturing.
Since it is only a product related to 2,36, it does not require any special equipment such as a curved surface gauge, and since stable brazing properties can be obtained, it is necessary to check whether bending processing has an adverse effect on the bonding quality and strength of the panel. There is no particular need for an inspection process or an inspection device for checking. Therefore, the honeycomb panel 10 having a curved surface can be obtained without requiring a significant change, expansion, investment, or the like of manufacturing equipment. In addition, in this embodiment, since the pressing force is applied to the flat panel 24 by the weight of the upper press jig 32, there is an advantage that a hydraulic press mechanism or the like is not required.

Furthermore, in the manufacturing method of the present embodiment, since bending and brazing are continuously performed in the same heating furnace 48, energy consumed is limited to the case of manufacturing a flat panel. Since the temperature rises of the upper and lower press jigs 32, 36, etc. are only added and are substantially the same,
(1) Regardless of whether the bending in the furnace is performed only by the weight of the upper press jig 32 or the like, or the case where a hydraulic or mechanical press device installed in the furnace is used, It does not require a load exceeding the load required for brazing (the load for uniformly applying a pressing force to the flat panel 24), and almost no extra energy is consumed for the bending process. ) The energy consumed for raising the temperature of the upper and lower press jigs 32 and 36, etc.
The bending processed retrieval and the next set of processing panels 24 of the flat panel 24 from 36 can also be saved by carrying out a high temperature region, the panel with the upper and lower press jig 32, 36 as in the present embodiment 24 In the case where cooling is performed in a state in which pressure is applied, a large amount of energy can be saved by introducing a heat recycling system that uses the heat taken from the press jigs 32 and 36 at the time of cooling. There are advantages.

Further, in the manufacturing method of this embodiment,
In a state in which the constituent members 16, 18, 20, 22 are combined, they are integrally bent by a single upper and lower press jigs 32, 36, and the bending process is performed for the next brazing process. Since it is performed rationally and continuously, the "clearance at the joint" important for brazing is suppressed to a very small value, and there is an effect that occurrence of defective brazing is drastically reduced.

Further, in the manufacturing method of the present embodiment, the bent flat panel 24 is sandwiched between the upper and lower press jigs 32 and 36 having the pressurized surfaces 30 and 34 machined with high precision in advance. By cooling, the curved shape of the panel comes into contact with the panel, so that the curvature accuracy of the obtained honeycomb panel 10 substantially matches the curvature of the pressing surfaces 30 and 34, and the curved shape of the panel is extremely high. And there is also an effect that the curvature correction by a press machine or the like is not required.

Incidentally, according to the present embodiment, a honeycomb panel was actually manufactured by the following specific steps, and the obtained honeycomb panel was evaluated.

In such an experiment, first, four hollow members (width: 37 mm, height: 28 mm, wall thickness: 2 mm) having a mouth-shaped cross section, which are extruded materials of No. 6000 series, were used and brazed by combining them. By joining, length: 840mm,
A frame 16 having a rectangular frame shape with a width of 540 mm is formed.
% Brazing sheet (thickness: 0.2 mm) clad with a 70% brazing material was corrugated into a continuous semi-hexagonal shape (corrugated shape) in the same manner as in the above-described embodiment. The honeycomb core 18 having a cell size (diameter of the inscribed circle of the cell): 30 mm as a whole is installed in parallel, and the frame 16 and the honeycomb core 18 are sandwiched from both sides so that they are on the inside. No. 6000 brazing sheet (thickness: 1.0) with a brazing material having a cladding ratio: 10%
mm) upper and lower panels (length: 840mm, width: 540m)
The flat panel assembled by superimposing m) was used. Then, the flat panel is set between the upper and lower press jigs as in the above embodiment, and the pressing force applied to the flat panel by the upper press jig and the pressing mass is set to 105.
kg. Under the action of the pressing force, only a slight elastic deformation occurred on the flat panel. Next, the upper and lower press jigs on which the flat panels were set were set in a vacuum heating furnace, and heated in a vacuum at about 5 ° C./min. According to another experiment in which heating was stopped halfway, bending of the panel was started at about 400 ° C and about 460 ° C.
C. was almost complete (about 12 minutes during this time). Then, the panel was heated to about 600 ° C. to complete the brazing. After the brazing was completed, the upper and lower press jigs 32 and 36 were taken out of the heating furnace with the panel sandwiched therebetween, and rapidly cooled by a dedicated cooling facility. The above process is total 1
The test was repeated 0 times to obtain Examples Nos. 1 to 10, and the quality was inspected for each. The results obtained are shown in Table 1 below.

For reference, according to a conventional curved surface brazing method, a separately bent frame body is used, a honeycomb core is incorporated in the inside thereof, and a pre-bent upper and lower face plate is overlapped. The resulting curved panel was sandwiched between upper and lower press jigs, heated under pressure, and brazed to obtain a honeycomb panel having a structure similar to that of the above embodiment. The same quality inspection as that of the above-mentioned example was performed on them, and the obtained results are shown in Table 1 below as Comparative Examples Nos. 1 to 3. In Comparative Examples 1, 2, and 3, 10
5 kg (Comparative Example 1), 360 kg (Comparative Example 2), 520 kg
Brazing was performed under the pressure of (Comparative Example 3).

[0059]

[Table 1]

As is clear from the results in Table 1,
The honeycomb panel having the curved surface manufactured according to the present invention was excellent in both the brazing condition and the dimensional (shape) accuracy, and was more beautiful in appearance than the honeycomb panel of the comparative example. Further, in the honeycomb panel manufactured according to the present invention, defects such as turbulence and deformation of the core material were not recognized,
It was confirmed that a honeycomb panel having a curved surface of the same quality as that of a flat panel could be stably obtained.

Next, FIGS. 9 to 11, FIGS. 13 to 15, and FIGS.
18 to 19 and FIGS. 19 to 21 show steps as another embodiment of the manufacturing method according to the present invention, respectively.
In each of these embodiments, the frame 16
It is characterized by its structural point and the function based on it, and the manufacturing process is the same as that of the first embodiment. In the drawings, members and portions having the same structure as in the first embodiment will be denoted by the same reference numerals as those in the first embodiment, and detailed description thereof will be omitted.

First, in the second embodiment shown in FIGS. 9 to 11, the frame members 50, 50 extending in the bending direction (x direction), 50,
Both the upper and lower plates 50 and 22 are respectively extended at both ends from a target edge of the honeycomb panel in the bending direction by a predetermined length: A in the bending direction. In addition, these extension portions 52 each include:
As shown in FIG. 10, a notch groove extending in a width: d from the extended front end toward the inside in a substantially central portion of the upper and lower face plates 20 and 22 in the overlapping direction (the thickness direction of the panel). 54 are formed. The length of the cutout groove 54 is shorter than that of the extended portion 52 so as not to reach the target product portion of the honeycomb panel.

The extension portion 5 having such a cutout groove 54
When the bending process is performed using the flat panel 24 provided with the second embodiment according to the process of the first embodiment, first, as shown in FIG. The distal end portion of the extended portion 52 is brought into contact with the concave pressing surface 30 of the jig 32 and serves as a pressing force application point. Here, since the distal end portion of the extension portion 52 is easily deformed by the notch groove 54, a portion of the extension portion 52 above the notch groove 54 (the upper press jig 32 side) Portion) is bent downward (toward the lower press jig), whereby the upper surface 56 of the extension portion 52 is tapered so as to be inclined in substantially the same direction as the concave pressing surface 30 of the upper press jig 32. It has a tapered shape.

Then, the bending process by the upper and lower press jigs 32 and 36 progresses, and when the bending process approaches the end, FIG.
As shown in FIG. 1, the upper surface 56 of the tapered extension 52 before the lower surface 58 of the extension 52 is bent into a shape along the convex pressing surface 34 of the lower press jig 36. Of the concave pressing surface 30 of the upper press jig 32
And the distal end portion and the base end portion of each extension portion 52 are in contact with the concave pressing surface 30 of the upper press jig 32, whereby the product portion of the honeycomb panel is removed. The upper side surface of the frame member 50 is brought into contact with the concave pressing surface 30 of the upper press jig 32 over the entire surface, and the bending process is completed. After the completion of the bending and brazing, each extension 52 is cut into a honeycomb panel of a desired size.

Therefore, in the present embodiment, the bending moment acting on each of the contact points of the upper press jig 32 and the lower press jig 36 with respect to the frame member 50 at the stage before the end of the bending is reduced. At both end portions of the frame member 50, extension portions 52 are provided, each of which is easily deformed by the notch groove 54 into a shape along the concave pressing surface 30 of the upper press jig 32. Even if the extended portion 52 is not bent into a shape along the pressing surfaces 30 and 34 of the upper and lower press jigs 32 and 36, the panel portion to be a product is formed on the entire upper and lower surfaces of the panel by the upper and lower press jigs. 3
2, 36 pressing surfaces 30, 34 can be brought into contact with each other. That is, both ends of the frame body 16 cannot be bent because the bending moment is reduced, and FIG.
As shown in FIG. 2, it is possible to advantageously prevent the occurrence of a "knot" in which the upper press jig 32 is lifted up from the upper surface of the panel by the both end portions of the frame body 16 as if it were pulled. In FIGS. 10 and 11, etc., the panel is schematically shown, and the illustration of the face plate and the like is omitted. Also, in FIGS. 8 and 9, only the frame members 50 and 50 are extended from the product dimensions of the panel.
22 may also be formed with the frame members 50, 50 in an extended manner.

Therefore, according to the method of this embodiment, when the flat panel 24 is bent, the part of the panel 24 which is to be a product is advantageously formed over the entire surface of the upper and lower press jigs 32 and 36.
Are pressed into contact with the pressing surfaces 30 and 34, so that the workpiece is processed with higher accuracy so as to have a desired curved surface shape, and the pressing force is advantageously reduced over the entire upper and lower surfaces of the product portion. Therefore, stable brazing can be performed.

According to the method of this embodiment, the extension 5
2 also has the advantage that a larger bending moment can be exerted on the frame 16.

In particular, the method of the present embodiment can be advantageously applied to a honeycomb panel having a curved surface with a small radius of curvature, a thick honeycomb panel, or the like, whereby a desired curved surface shape can be formed with excellent quality. It can be manufactured. Further, the formation of the extended portion 52 in the frame member 50 only requires appropriately setting the dimensions of the frame member 50, and the notch groove 54 can be easily formed by simple cutting or the like. Therefore, there is also an advantage that the above-described excellent effects can be obtained.

Next, in the third embodiment shown in FIGS. 13 to 15, similarly to the second embodiment shown in FIGS. Are formed, and a spacer 60 such as a brazing sheet formed of a brazing material is provided in each of the notch grooves 54 of each of the extension portions 52. It is sandwiched and assembled.

When bending is performed in accordance with the process of the first embodiment by using the flat panel 24 having the extended portion 52 in which the spacer 60 is assembled in the notch groove 54, first, the brazing material is melted. In the bending step performed at a temperature equal to or lower than the temperature, as shown in FIG. 14, the notch groove 54 does not function due to the spacer 60, and a large bending strength is secured in the extension portion 52. Is guaranteed to be the point of action of the pressing force, and a large bending moment acts on the flat panel. Then, when the brazing material is heated to the melting temperature at the end stage of the bending process, as shown in FIG. And the upper surface of the extended portion 52 is
Is deformed along the pressing surface 30 of the
Squeezing of the upper press jig 32 is prevented.

Therefore, according to the method of this embodiment, since the extension 52 is excessively deformed from the beginning of the bending process, the base end of the extension 52 comes into contact with the pressing surface 30 of the upper press jig 32. As a result, the bending moment exerted on the flat panel 24 due to the base end portion acting as a pressing force acting point can be effectively prevented, and good bending accuracy in a part to be a product is secured. In addition, during brazing, since the extended portion 52 is easily deformed and an effective pressing force is applied to the entire surface of the flat panel 24, excellent brazing accuracy can be exhibited.

In the fourth embodiment shown in FIGS. 16 to 18, similarly to the second embodiment shown in FIGS. Are formed, and the upper surface 56 of each of the extended portions 52 is provided with a taper 62 in a direction in which the height of the frame member 50 decreases toward the distal end. Have been. That is, the taper 6
2, each extension 52 has a smaller section modulus and is more easily bent toward the distal end.
The upper side surface 56 of each extension portion 52 has a shape just after the extension portion 52 is deformed in the second embodiment, and has a shape along the press surface of the upper press jig 32. From this, the cutting of the upper press jig 32 by the extension portion 52 can also be effectively prevented.

Therefore, even in the method of the present embodiment in which the extended portion 52 provided with the taper 62 is provided, the same effects as those of the second embodiment can be effectively exhibited. .

Further, in the fifth embodiment shown in FIGS. 19 to 21, each extension 5
2, the taper 62 in the direction in which the height dimension of the frame member 50 decreases toward the distal end side.
Is attached. That is, due to the taper 62, each extension portion 52 has a small section modulus, and is more easily bent toward the distal end side.

Accordingly, even in the method of the present embodiment in which the extended portion 52 provided with the taper 64 is provided, the same effects as those of the second embodiment can be effectively exhibited.

Although the embodiments of the present invention have been described in detail above, these are literal examples, and the present invention is not construed as being limited to only these specific examples.

For example, in the above-described embodiment, the length direction of each honeycomb forming material 26 corresponds to the direction in which the panel is to be bent (in FIG. 3,
The honeycomb core 18 is formed so as to be orthogonal to (x direction), but in addition, as shown in FIGS. 22 and 23, the length direction of each honeycomb forming material 26 is The honeycomb core 18 can be formed so as to be in the bending direction (the x direction in FIG. 23). When such a honeycomb core 18 is employed, even when the core height is high and the bending radius of curvature is small, the adjacent honeycomb forming materials 26, 26 due to the sagging of the respective honeycomb forming materials 26 during the heating deformation process. Can effectively be prevented from occurring, and the honeycomb core 18 which is substantially uniformly curved as a whole can be advantageously obtained.
When such an arrangement direction of the honeycomb forming materials 26 is employed, in the bending deformation step, both ends of the honeycomb forming materials 26 in the longitudinal direction (particularly, the corners on the outer peripheral side (panel convex surface side)). On the other hand, since the pressing force continues to be applied, the thin honeycomb forming material 26 may be deformed. To prevent such partial deformation, for example, as shown in FIG. , Each honeycomb forming material 2
It is desirable to form the reinforcing portion 70 by, for example, bending both end portions in the length direction of 6.

In the above embodiment, an example of manufacturing a honeycomb panel having a single curved surface has been described. However, when manufacturing a sandwich panel having various curved surface shapes such as a composite curved surface and a spherical curved surface, The present invention can be applied effectively.

Further, in the above-described embodiment, the honeycomb panel 1 having the honeycomb core 18 having the hexagonal cells formed therein is used.
Although the manufacturing method of 0 has been described, in addition to the manufacture of honeycomb panels having triangular cells that can be easily spherically processed, square cells that can be easily formed, and the like, further, corrugation fin materials that do not have a honeycomb structure, The present invention can be similarly applied to the manufacture of various types of panels joined by brazing, such as sandwich panels in which a shape member or the like is sandwiched between face plates, or other than sandwich panels.

Further, contrary to the above embodiment, the upper press jig 32 is provided with a convex pressing surface corresponding to the concave side surface shape of the curved panel, and the lower press jig 36 is provided with a convex pressing surface. A concave pressing surface corresponding to the side surface shape may be provided. However, if the upper press jig 32 having the concave pressing surface 30 and the lower press jig 36 having the convex pressing surface 34 are used as in the above-described embodiment, the center of the panel to be formed is upwardly convex. Therefore, there is an advantage that the excess brazing material is prevented from accumulating in the central portion of the panel, and uniform brazing property can be obtained.

In the present invention, heating in the panel deformation or brazing step is performed in the atmosphere, or a pressurizing method using a hydraulic device is used in the panel deformation step.
Of course, it is possible.

Further, the material of the panel to which the present invention is applied is not limited to the aluminum alloy, and various materials such as steel and stainless steel can be adopted.
It goes without saying that the heating temperature, the material of the brazing material, and the like are appropriately set depending on the material.

Further, the extension portion 5 formed on the frame material 50
The number, length, etc. of 2 are not limited and are appropriately set according to the bending rigidity and size of the panel, and three or more extending portions from both side edges in the bending direction. It is also possible to form

Further, the notch groove formed in the extension portion 52 of the frame member 50 may have a wedge shape or the like which spreads toward the opening side.

In addition, although not enumerated one by one, the present invention
Based on the knowledge of those skilled in the art, various changes, modifications, improvements, and the like can be made, and unless such embodiments depart from the spirit of the present invention.
Both are included in the scope of the present invention,
Needless to say.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing a specific example of a honeycomb panel to which a manufacturing method of the present invention is applied.

FIG. 2 is a perspective view for explaining a flat panel assembling step when manufacturing the honeycomb panel shown in FIG. 1 according to the present invention.

FIG. 3 is a plan view for explaining a process of assembling a honeycomb core in the flat panel shown in FIG. 2;

FIG. 4 is a side view showing a state where the flat panel shown in FIG. 2 is mounted on a press jig.

FIG. 5 is an explanatory view showing a state where the press jig shown in FIG. 4 is set in a heating furnace.

FIG. 6 is an explanatory view showing a middle of bending of a flat panel.

FIG. 7 is an explanatory view showing an end state of bending processing of the flat panel.

FIG. 8 is a perspective view showing a flat panel for explaining a second embodiment of the present invention.

FIG. 9 is an enlarged side view showing a main part of the flat panel shown in FIG. 8;

FIG. 10 is an explanatory diagram for explaining a bending step in manufacturing a honeycomb panel having a curved surface according to the present invention using the flat panel shown in FIG. 8;

FIG. 11 is an explanatory diagram showing an end state of the bending process shown in FIG. 10;

FIG. 12 is an explanatory view showing a next state of a flat panel in a bending direction edge portion.

FIG. 13 is an enlarged side view of a main part of a flat panel corresponding to FIG. 9 for explaining a third embodiment of the present invention.

FIG. 14 is an explanatory diagram for explaining a bending step in manufacturing a honeycomb panel having a curved surface according to the present invention using the flat panel having the structure shown in FIG. 13;

FIG. 15 is an explanatory diagram showing an end state of the bending step shown in FIG. 14;

FIG. 16 is an enlarged explanatory view of a main part of a flat panel for explaining a fourth embodiment of the present invention.

FIG. 17 is an explanatory diagram for explaining a bending step in manufacturing a honeycomb panel having a curved surface according to the present invention using the flat panel having the structure shown in FIG. 16;

FIG. 18 is an explanatory diagram showing an end state of the bending step shown in FIG. 17;

FIG. 19 is an enlarged explanatory view of a main part of a flat panel for explaining a fifth embodiment of the present invention.

20 is an explanatory diagram illustrating a bending step in manufacturing a honeycomb panel having a curved surface according to the present invention using the flat panel having the structure illustrated in FIG. 19;

FIG. 21 is an explanatory view showing an end state of the bending step shown in FIG. 20;

FIG. 22 is a partially cutaway perspective view corresponding to FIG. 1 and showing still another specific example of the honeycomb panel to which the manufacturing method of the present invention is applied.

FIG. 23 is a plan view, corresponding to FIG. 3, for explaining a process of assembling the honeycomb core when the honeycomb panel shown in FIG. 22 is manufactured according to the present invention.

24 is an enlarged perspective view showing an end structure of a honeycomb forming material suitably used in the honeycomb panel shown in FIG. 22.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Honeycomb panel 16 Frame 18 Honeycomb core 20 Upper surface plate 22 Lower surface plate 24 Flat panel 26 Honeycomb forming material 32 Upper press jig 36 Lower press jig 48 Heating furnace 52 Extension part 54 Notch groove 60 Spacer 62, 64 Taper

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Isao Ezawa 5-1-1-3 Shimbashi, Minato-ku, Tokyo Inside Sumitomo Light Metal Industries Co., Ltd. (72) Inventor Masaki Kumagaya 5-3-1, Shimbashi, Minato-ku, Tokyo No. Sumitomo Light Metal Industries Co., Ltd. (72) Inventor Yuji Hisatomi 5-11-3 Shimbashi, Minato-ku, Tokyo Sumitomo Light Metal Industries Co., Ltd. (56) References JP-A-6-7865 (JP, A) Kaihei 6-182532 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) B21D 47/00

Claims (13)

(57) [Claims] 1. A method for manufacturing a panel having a curved shape by brazing a plurality of constituent members, wherein the plurality of constituent members are overlapped on a frame and on both sides of the frame.
Two upper and lower face plates, and the two face plates in the region of the frame body.
And a honeycomb-shaped core interposed between the face plates of
By combining these components with each other while allowing relative displacement, a hollow structure support is provided.
A step of obtaining a flat panel having a flat plate shape, which is a sandwich panel; a step of setting the flat panel between upper and lower press jigs each having a pressing surface corresponding to a desired curved shape; By heating the flat panel set in between to the softening temperature and applying a pressing force between the upper and lower press jigs, the flat panel is deformed along at least one of the pressing surfaces of the upper and lower press jigs. And brazing the contact portions of the plurality of components deformed by pressurization between the upper and lower press jigs under pressure by the upper and lower press jigs. Bonding the brazed panel having a curved surface. 2. The method for manufacturing a brazed panel having a curved surface according to claim 1, wherein the pressing force applied between the upper and lower press jigs is changed according to the deformation of the flat panel. 3. The method according to claim 1, wherein the pressing force applied between the upper and lower press jigs is adjusted so that plastic deformation does not occur in the flat panel until the flat panel is heated to a softening temperature. A method for producing a brazed panel having the above-mentioned curved surface. 4. After the deformation of the flat panel by the press between the upper and lower press jigs is completed, the brazing material is melted and joined at the abutting portions of the plurality of constituent members constituting the flat panel. 4. A method for manufacturing a brazed panel having a curved surface according to any one of claims 3 to 3. 5. The method for manufacturing a brazed panel having a curved surface according to claim 1, wherein the heating of the flat panel is performed in a vacuum or an inert gas. 6. The method for manufacturing a brazed panel having a curved surface according to claim 1, wherein a pressing force is applied between the upper and lower press jigs by the weight of the upper press jig. 7. The method according to claim 1, wherein the plurality of components are brazed to each other under pressure by the upper and lower press jigs, and then cooled while being pressed by the upper and lower press jigs.
7. A method for manufacturing a brazed panel having a curved surface according to any one of claims 1 to 6. 8. A honeycomb core is formed by arranging a plurality of corrugated moldings in parallel, and each of the corrugated moldings is arranged to extend substantially orthogonal to the bending direction. A method for manufacturing a brazed panel having a curved surface according to claim 1 . By 9. be arranged in parallel a plurality of corrugated profiled, with composing the honeycomb core, according to claim 1, arranged so as to extend their respective corrugated profiled substantially song adult direction 9. A method for manufacturing a brazed panel having a curved surface according to any one of claims 1 to 8 . 10. While allowed allow relative displacement of the corrugated profiled said plurality arranged in parallel to the frame in the area, according to claim 8 for deforming said flat panel to a curved shape
Or a method for producing a brazed panel having a curved surface according to item 9 . 11. A frame constituting said sandwich panel, or said frame and said at least one face plate are extended in a bending direction from a product size of a target brazing panel, and said frame is extended. The method for manufacturing a brazed panel having a curved surface according to any one of claims 1 to 10, wherein a notch groove extending inward from an extension end portion of an intermediate portion of the face plate in the overlapping direction is provided for the portion. 12. The method for manufacturing a brazed panel having a curved surface according to claim 11 , wherein a spacer is mounted in the cutout groove. 13. A frame constituting said sandwich panel, or said frame and said at least one face plate are extended in a bending direction more than a product size of a target brazing panel, and said frame is extended. The curved surface according to any one of claims 1 to 12 , wherein at least one surface in the overlapping direction of the face plates in the portion is tapered in a direction tapering toward the front end side in the extension direction. A method for manufacturing a brazed panel having the same.