JPH0243031A - Manufacture of flexible honeycomb core - Google Patents

Abstract

PURPOSE:To realize high quality flexible honeycomb core by a method wherein corrugated sheet materials with nearly trapezoidal wave-like folds are piled up, joined with amorphous soldering material and finally extended. CONSTITUTION:Each corrugated sheet material 7, in which nearly trapezoidal wave-like folds are produced by continuously bending, is corrugated by passing a flat sheet material through a corrugating device. Next, on the surface at the ridge or trough of the corrugated sheet material 7, amorphous soldering material 8 is applied at every other ridge or trough and provisionally fixed to the material 7 by spot-welding or adhesive bonding. Next, fluxing agent is used as stopping material 9 and applied to the surface, onto which no amorphous soldering material 8 is provided, of the corrugated sheet material 7. And several layers of the corrugated sheet materials, on each of which the amorphous soldering material 8 and the stopping material 9 are annexed, are piled up vertically. The respective piled up corrugated sheet materials 7 are pressed vertically and, after that, mutually and locally joined by thermally fused amorphous soldering material 8. Next, the joined corrugated sheet materials 7 are placed on a plate bed and extended by moving pins, each of which is inserted in a cell 6 at one of both side ends, with a moving mechanism, resulting in letting tensile force apply to the corrugated sheet materials 7 so as to set apart their non-joined parts through deformation and separation into the predetermined shape. As a result, a special shape honeycomb core is lightly and easily obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a method for manufacturing a flexible honeycomb core. That is, the present invention relates to a method of manufacturing a flexible honeycomb core for forming a curved surface, which is suitable for forming a curve into a complicated curved surface such as a cubic surface.

"Technical background" First, we will discuss its technical background.

Honeycomb cores generally have the characteristics of being easy to manufacture and having a high strength-to-weight ratio.As shown in FIG. It consists of a flat collection of.

By the way, when an attempt is made to form a curve into a curved surface using the conventional-g honeycomb core 3 having cells 2 such as regular hexagons, the following will occur.

In other words, when the stretching direction W (or ribbon direction L) is curved along the curved surface, the ribbon direction L perpendicular to this direction
(or the direction of expansion W) is conversely warped upwards and distorted into a saddle shape, which does not follow the curved surface and does not fit. Moreover, if force is applied to the cell wall 1 to make it fit along a curved surface, the cell wall 1 may break or peeling may occur at the joint.

As described above, conventionally, it has been difficult to form a curve into a complex curved surface such as a cubic curved surface by using a general honeycomb core 3.

Therefore, firstly, an over-extended core has been conventionally provided.

That is, this overextended core is made of a planar assembly of substantially rectangular cells obtained by further expanding the above-described general honeycomb core 3 in the expansion direction W by a predetermined amount.

When this overextended core is curved in the ribbon direction along a curved surface, no problem occurs. However, if you try to curve the direction of expansion along a curved surface, the direction of expansion will be as if it were a straight line.
The cell walls are located like a plate and have high bending rigidity, making it extremely difficult to curve the expansion direction along a curved surface. Therefore, even if such an overextended core is used, it is difficult to accurately curve a complex curved surface such as a cubic curved surface.

Therefore, secondly, an improved version of the overextended core has been conventionally provided.

In other words, this improved honeycomb core holds the overextended core fixedly in one direction of expansion,
It is formed by gradually applying a uniform predetermined load in the direction of the ribbon from the other side, and the cell walls in the stretching direction are slightly bent inward midway, so that the cells form an approximately drum shape.

With this honeycomb core, it has become possible to form curves into complex curved surfaces such as cubic surfaces with high precision, regardless of whether it is in the ribbon direction or the stretching direction.
It has been pointed out that the manufacturing problem is that the molding is troublesome as described above.

Especially when the thickness of the overextended core before molding is thin or its size is large, it is extremely difficult to gradually apply a predetermined load, which is a fatal flaw in that the shape of each cell becomes uneven. was pointed out.

The technical background is as above.

"Prior Art" Therefore, as a third conventional technique, a honeycomb core similar to the flexible honeycomb core 4 shown in FIG. 3 has been provided.

That is, in a honeycomb core similar to this flexible honeycomb core 4, each cell wall 5 is entirely bent in the middle, and each cell 6 has a rounded, substantially convex shape.

Because of this shape, the honeycomb core obtained by adding W44 to the flexible honeycomb core 4 is extremely flexible, and can be processed to form curves into complex curved surfaces such as cubic curved surfaces with high precision in any direction. .

[Problems to be Solved by the Invention] By the way, a honeycomb core similar to the conventional flexible honeycomb core 4 has the following problems. Second
．． A third problem was pointed out.

First of all, there was a problem that molding was extremely troublesome.

In other words, a honeycomb core similar to this flexible honeycomb core 4 is made by first preparing a corrugated sheet material in which a predetermined shape with special unevenness is continuously bent by corrugating a flat sheet material, and then preparing a plurality of such corrugated sheet materials. , they were formed by stacking them one on top of the other and bonding and bonding predetermined parts with an adhesive or brazing material.

In other words, as mentioned above, a honeycomb core similar to the flexible honeycomb core 4 having a special shape in which each cell wall 5 is bent in the middle and each cell 6 is rounded and has a substantially convex shape is made with a high height. The stretching method was considered difficult to obtain in a stable and uniform shape with good quality. Conventionally, corrugated sheets of a predetermined shape were first made as described above, and then they were bonded together one by one to form the corrugated sheet.

Therefore, although honeycomb cores similar to this flexible honeycomb core 4 can be formed into curves with high precision after the fact, the manufacturing problem is that the forming is extremely troublesome and extremely costly. It had been pointed out.

Secondly, various problems have been pointed out due to the adhesives commonly used in manufacturing.

That is, a honeycomb core similar to this flexible honeycomb core 4 has been formed by joining predetermined corrugated sheet materials with an organic adhesive.

Therefore, (1) a honeycomb core similar to the flexible honeycomb core 4 has a low heat resistance temperature, and therefore is not suitable for use at high temperatures, for example, as a heat-resistant member. (2) The bonding strength of a honeycomb core similar to the flexible honeycomb core 4 was determined by the generally low strength of an organic adhesive, and there were also difficulties in terms of strength.

(3) Since the organic adhesive is applied in the form of a paste, it often flows out from the fixed position after application, resulting in quality problems such as poor dimensional accuracy of honeycomb cores similar to flexible honeycomb core 4. .

Furthermore, (4) since an organic solvent or the like is used in combination, phenomena such as generation of voids and shrinkage are observed, and from this point of view as well, the strength of the honeycomb core similar to the flexible honeycomb core 4 is poor. (5) Similarly, since organic solvents and the like are used in combination, if a honeycomb core similar to the post-flexible honeycomb core 4 is used at high temperatures, harmful gases may be generated, which poses a safety problem.

Secondly, various problems have been pointed out in honeycomb cores similar to the conventional flexible honeycomb core 4 due to the use of adhesives in this way.

Thirdly, instead of such adhesives, brazing materials such as silver solder and nickel solder have often been used for bonding, but various problems have been pointed out due to such brazing materials.

In other words, a honeycomb core similar to this flexible honeycomb core 4 can also be formed by attaching a crystalline brazing material such as limited brazing material or nickel brazing material to a predetermined location and then heating it to its melting temperature to join corrugated sheet materials. Ta.

(a) First, there was a problem with bonding strength. In other words, crystalline brazing filler metal has a crystal structure that is not a single phase, so as the temperature rises due to heating during the brazing process, it separates into a low melting point phase and a high melting phaseless phase. As a result, compositional segregation occurred, and so-called melt separation phenomenon also occurred. Therefore, the brazing filler metal has a negative effect on the mechanical strength and chemical properties of the joints of corrugated sheet materials.
The quality of the honeycomb core is unstable and the bonding strength is weak, and problems have been pointed out regarding the strength of the honeycomb core similar to the flexible honeycomb core 4 manufactured therewith.

Furthermore, (b) there was also a problem with the subsequent brazing of the surface plate.

That is, in general, the manufactured flexible honeycomb core 4 is formed into a predetermined curved surface, and then a surface plate is brazed to its outer surface using a brazing material, and then used for various purposes. By heating the surface plate for brazing, the brazing material that forms the honeycomb core joint similar to the previously brazed flexible honeycomb core 4 also has the same melting temperature. Adverse effects often result in melting again, and from this point of view, a problem has been pointed out regarding its strength. It was pointed out that it has poor heat resistance and is difficult to heat treat.

Thirdly, in a honeycomb core similar to the conventional flexible honeycomb core 4, various problems have been pointed out due to the use of such a crystalline brazing material.

In the conventional example, the first. Second. A third problem was pointed out.

The present invention has been made in view of the above-mentioned circumstances in order to solve the problems of the above-mentioned conventional examples.

First, by stacking and bonding corrugated sheet materials in a predetermined manner and then stretching them, a high-quality flexible honeycomb core with a uniform and stable shape can be easily obtained. In addition, by not using adhesives for bonding, it has excellent heat resistance, bonding strength, dimensional accuracy, etc., and is free from voids and shrinkage.

There is no generation of harmful gases, and thirdly, by using a non-crystalline amorphous brazing material for joining, it has particularly excellent joint strength, is not adversely affected by subsequent brazing of the surface plate, and is heat resistant. The purpose of this study is to propose a manufacturing method for flexible honeycomb cores that is excellent in terms of manufacturing efficiency.

"Means for Solving the Problem" The technical means of the present invention to achieve this object are as follows.

This manufacturing method includes the following preparation process, brazing material application process, stop agent application process, lamination process, brazing process, spreading process, etc.

In the preparation step, a corrugated sheet material in which approximately trapezoidal wave-like unevenness is continuously bent is prepared in advance.

In the brazing material application step, amorphous brazing material is provided every other row on the top or valley surface of the corrugated sheet material.

In the stop agent application step, a stop agent is applied to the surface of the corrugated sheet material on which the amorphous brazing material is not provided.

In the lamination step, a plurality of corrugated sheet materials are stacked such that the positions where the amorphous brazing material is provided are alternately shifted between the upper and lower corrugated sheet materials.

In the brazing process, the stacked corrugated sheets are pressurized.

Heat and partially join by soldering.

In the stretching step, the joined corrugated sheet material is stretched by applying a tensile force in the stacking direction, so that each cell wall is bent in the middle, and each cell forms a rounded substantially convex shape. A flexible honeycomb core is formed.

"Function" Since the manufacturing method according to the present invention includes such means, it works as follows.

First, the corrugated sheet material prepared in the preparation step has a simple substantially trapezoidal wave shape and is continuously bent. In the brazing material application step, amorphous brazing material may be simply provided every other row on the surface of the top or valley portion of the corrugated sheet material. In the stop agent application step, the stop agent may be applied to other surfaces.

Also, in the stacking of corrugated sheet materials in the lamination process, it is sufficient to simply shift the positions of the amorphous brazing filler metals upward and downward.

The brazing process also uses −C pressure.

This is done by heating.

In this way, each step is performed simply, easily and reliably.

In the final stretching step, a flexible honeycomb core in which each cell wall is bent in the middle and each cell has a rounded, substantially convex shape is obtained all at once by stretching without bonding them together one by one. In other words, a flexible honeycomb core with a special shape can be easily and stably obtained with a uniform shape.

As described above, firstly, a flexible honeycomb core can be obtained easily, uniformly, and stably.

In Brush 2, an amorphous brazing material is used for joining in the brazing material attachment process and the brazing process, and no adhesive is used.

Therefore, this flexible honeycomb core has excellent heat resistance, bonding strength, etc., does not flow out, and has excellent dimensional accuracy.
In addition, no voids or shrinkage are observed, and from this point of view, the bonding strength is excellent, and no harmful gases are generated even when used at high temperatures.

Third, a non-crystalline brazing filler metal is used for bonding, and no crystalline brazing filler metal is used.

Therefore, in this flexible honeycomb core, the amorphous brazing material melts all at once during the brazing process, causing no segregation, and is diffused and alloyed with the corrugated sheet material.
Since its melting temperature is higher than that of ordinary amorphous brazing filler metal, it has significantly superior bonding strength. Also, since such alloying makes the melting temperature higher than that of ordinary alloys, subsequent brazing of the surface plate will not have any adverse effects. It also has excellent bonding strength and general heat resistance after the process.

Now, after the fact, such a flexible honeycomb core has 3
Curve formation processing is performed with high accuracy on complex curved surfaces such as curved surfaces.

"Example" The present invention will be described in detail below based on the example shown in the drawings.

FIG. 1, FIG. 2, and FIG. 3 are explanatory diagrams each used to explain an embodiment of a method for manufacturing a flexible honeycomb core 4 according to the present invention. This manufacturing method includes the following preparation process, brazing material application process, stop agent application process, lamination process, brazing process, spreading process, etc.

First, let's talk about the preparation process.

In this preparatory step, 1, the corrugated sheet material 7 is corrugated by passing the flat sheet material through a corrugating machine (not shown), so that approximately trapezoidal irregularities are continuously bent as shown in FIG. is prepared in advance.

The corrugated sheet material 7, which is the base material, is made of aluminum.

Thin plates, foils, etc. of nickel, various alloys, other metals, etc. are appropriately selected and used.

The preparation process is as follows.

Next, the process of attaching the brazing material will be described.

FIG. 1 is a perspective explanatory view of a corrugated sheet material 7 on which an amorphous brazing filler metal 8 is provided and a stop agent 9 is applied in a brazing filler metal attaching step and a stop agent attaching step to be described later.

In this brazing material application step, the amorphous brazing material 8 is applied to every other row of the top or trough surface of the corrugated sheet material 7 prepared in the above-mentioned preparation step. In the illustrated example, an amorphous brazing filler metal 8 is applied to every other top surface of the corrugated sheet material 7.

This amorphous brazing filler metal 8 has a layered thickness and is temporarily fixed by spot welding or adhesion.

By the way, the amorphous brazing filler metal 8 refers to a nickel-based alloy or a cobalt-based alloy to which iron, silicon, boron, phosphorus, chromium, molybdenum, tungsten, etc. have been appropriately added as additional elements, by liquid quenching, that is, after being in a high-temperature molten state. A non-crystalline brazing filler metal manufactured by rapid cooling at ultra-high speeds.

The brazing material attachment process is as follows.

Next, the stop agent application process will be described.

The stop agent 9 is generally a flux agent, and is applied in a layer to the surface of the corrugated sheet material 7 on which the amorphous brazing material 8 is not provided.

This stop agent 9 is used to stop the amorphous brazing material 8 heated and melted in the brazing process described below so that it does not exceed a predetermined brazing portion and cause brazing. The stop agent 9 may be provided, for example, on the surface of the corrugated sheet material 7, as shown in FIG.
Irrespective of the example shown in the drawings, on the surface of the corrugated sheet material 7, only a part of the brazing prevention range between the amorphous brazing filler metals 8, that is, only on both sides of the amorphous brazing filler metal 8 may be provided.

Note that this stop agent application step is performed before or after the above-mentioned brazing material application step.

The stop agent application process is as follows.

Next, the lamination process will be described.

FIG. 2 is an explanatory front view of the corrugated sheet materials 7 stacked in the stacking process. In other words, in this lamination step, each corrugated sheet material 7 to which the amorphous brazing material 8 and stop agent 9 are attached in the above-mentioned brazing agent attaching step and stop agent attaching step,
It is stacked in layers one above the other. Then, the surfaces of the tops or troughs on which the amorphous brazing filler metal 8 is provided are alternately shifted left and right between the upper and lower corrugated plates 7, that is, shifted horizontally by one peak for each layer stacked. The corrugated sheet materials 7 are stacked one on top of the other with their unevenness, that is, the top and valley portions corresponding to each other.

The lamination process is as follows.

Next, the brazing process will be described.

In the brazing process, the corrugated sheets 7 stacked in the above-described lamination process are brazed by pressure and heating, and are partially joined. That is, each corrugated sheet material 7 stacked in a predetermined manner is -
After first being pressurized from above and below, they are partially joined together using heated and melted amorphous brazing filler metal 8.

This brazing is performed, for example, by a so-called vacuum heating method, and the corrugated sheet materials 7 stacked in the above-mentioned lamination process are placed in a vacuum furnace.
This is done by placing the amorphous brazing filler metal 8 and heating it to the melting temperature of the amorphous brazing filler metal 8. Since the purpose of heating in vacuum is to prevent oxidation, the so-called atmosphere heating method of heating in an inert gas atmosphere may be used instead of the vacuum heating method.

The brazing process is like this.

Next, we will discuss the expansion process.

The corrugated sheet material 7 joined in the above-mentioned brazing process is appropriately cut and then stretched by applying a tensile force in the stacking direction, that is, the stretching direction. This stretching is carried out using, for example, a stretching device, by placing the joined corrugated sheet material 7 on the plate stand, inserting pins into the cells 6 at both ends, and then moving the pins using a moving mechanism. It will be done.

In this way, a predetermined tensile force is applied to the corrugated sheet material 7 partially joined by the amorphous brazing filler metal 8, and the opposing non-joint portions are deformed and separated and separated into a predetermined shape.

FIG. 3 is an explanatory plan view of the flexible honeycomb core 4 formed by such a stretching process. In this flexible honeycomb core 4, each cell wall 5 is bent in the middle, and each cell 6 has a rounded substantially convex shape.

The expansion process is as follows.

The method for manufacturing the flexible honeycomb core 4 according to the present invention is as described above.

The operation etc. will be explained below.

First, the corrugated sheet material 7 prepared in the preparation step has a simple substantially trapezoidal wave shape, and is easily formed by continuous bending from a flat sheet material. Next, in the step of applying the brazing material, it is sufficient to simply provide the amorphous brazing material 8 every other row on the top or valley surface of the corrugated sheet material 7 (see FIG. 1). In the stop agent application step, the stop agent 9 may be applied to surfaces other than the amorphous brazing material 8 (see FIG. 1).

When stacking the corrugated sheet materials 7 in the next lamination step, it is sufficient to simply shift the positions of the amorphous brazing filler metals 8 between the upper and lower corrugated sheet materials 7 (see FIG. 2). The brazing process is also carried out by pressure and heating.

In this way, the preparation process, brazing material application process, stop agent application process, lamination process, brazing process, etc. are performed simply, easily and reliably.

In the final expansion process, the flexible honeycomb core 4, in which each cell wall 5 is bent in the middle and each cell 6 has a rounded, substantially convex shape, is expanded all at once without being pasted together one by one. can be obtained. In other words, the specially shaped flexible honeycomb core 4 can be obtained easily and extremely stably with the cells 6 etc. having a uniform shape and density (see FIG. 3).

As mentioned above, firstly, the flexible honeycomb core 4 is
It is simple, uniform and stably obtained.

In the writing 2, the joining in the brazing material attaching step and brazing step is performed by brazing with an amorphous brazing material 8, and no organic adhesive or organic solvent is used.

Therefore, (1) this flexible honeycomb core 4 has a high heat resistance temperature, and therefore can be used at high temperatures, and is suitable for use as a heat-resistant member, for example. (2) The bonding strength of the flexible honeycomb core 4 is guaranteed by the strength of the amorphous brazing filler metal 8, so there is no concern about its strength.

(3) The amorphous brazing material 8 is reliably brazed only in a predetermined brazing range by the stop agent 9. Therefore, the dimensional accuracy of the flexible honeycomb core 4 is good, and there is no concern in terms of quality.

In addition, (4) the amorphous brazing filler metal 8 does not cause phenomena such as generation of voids or shrinkage after the fact (from this point of view, there is no concern about the strength of the flexible honeycomb core 4). No harmful gas is generated even when used in the flexible honeycomb core 4, and there is no problem in terms of safety of the flexible honeycomb core 4.

As mentioned above, secondly, the harm caused by the use of adhesives, etc. is -
be swept away.

Third, a non-crystalline brazing filler metal 8 is used for bonding, and no crystalline brazing filler metal is used.

Therefore, by being pressurized and heated in the brazing step (a), the amorphous brazing filler metal 8 melts all at once and diffuses into the corrugated sheet material 7. First, since the amorphous brazing filler metal 8 does not have a crystalline structure, it melts all at once at a constant melting temperature and no segregation occurs. Alloyed between. Therefore, the joint of the corrugated sheet material 7 formed in this way has a high mechanical strength.

It has excellent chemical properties, stable quality, and extremely strong bonding strength. Therefore, the flexible honeycomb core 4 has extremely excellent strength.

(b) Furthermore, as mentioned above, the amorphous brazing filler metal 8 of the joint part
is diffused and alloyed, so its melting temperature is higher than that of ordinary amorphous brazing filler metal. So after the fact,
Even if a surface plate is brazed to such a flexible honeycomb core 4 using an amorphous brazing filler metal by heating it to its melting temperature, there is no possibility that the amorphous brazing filler metal 8 in the joint that has been alloyed previously will melt again. Definitely prevented. Therefore, the flexible honeycomb core 4 maintains extremely excellent strength without any change in its bonding strength.

(C) Since the bonding strength is strong as described above, it also has excellent heat resistance and ease of heat treatment.

Thirdly, as described above, by using the amorphous brazing filler metal 8, the harmful effects caused by the crystalline brazing filler metal are eliminated.

Now, since the flexible honeycomb core 4 has a special shape, such as each cell wall 5 being bent in the middle and each cell 6 forming a rounded, substantially convex shape, it will be possible to create a ribbon in the expanding direction after the fact. Curves can be formed into complex curved surfaces such as cubic curved surfaces with high precision regardless of the direction.

The above is the explanation of the operation, etc.

"Effects of the Invention" The method for manufacturing a flexible honeycomb core according to the present invention includes:
As explained above, the following effects are achieved by stacking approximately trapezoidal corrugated sheets in a predetermined manner, joining them using an amorphous brazing material, and then expanding them.

Firstly, a specially shaped flexible honeycomb core that can be processed to form curves on complex curved surfaces such as three-dimensional curved surfaces with high precision is easy to obtain and is cost effective, and the shape of its cells is also uniform and stable. You can get high quality products.

By not using adhesives for bonding, text box 2 has excellent heat resistance, strength, dimensional accuracy, etc., and also prevents voids, shrinkage, etc.
There is no generation of harmful gases, and from this aspect as well, a high quality flexible honeycomb core with uniform and stable cell shapes can be obtained.

Third, by using a non-crystalline amorphous brazing filler metal for joining, it has excellent strength, has no adverse effects even if the surface plate is brazed afterward, and has excellent heat resistance. A quality flexible honeycomb core can be obtained.

In this way, the problems that existed in this type of conventional example are completely eliminated, and the effects of the present invention are remarkable and great.

[Brief explanation of the drawing]

FIG. 1, FIG. 2, and FIG. 3 each serve to explain an embodiment of the method for manufacturing a flexible honeycomb core according to the present invention.
It is an explanatory diagram. FIG. 1 is a perspective explanatory view of a corrugated sheet material provided with an amorphous brazing material and coated with a stop agent in the brazing material application step and the stop agent application step, respectively. FIG. 2 is an explanatory front view of the corrugated sheet materials stacked in the stacking process. FIG. 3 is an explanatory plan view of a flexible honeycomb core formed by the stretching process. FIG. 4 is an explanatory plan view of a conventional honeycomb core. 4... 5... 6... 7... 8... 9... Flexible honeycomb core Cell wall Cell corrugated sheet material Amorphous brazing filler metal Stop agent Fig. 4/'''1 3''''

Claims (1)

[Claims] A corrugated sheet material in which substantially trapezoidal wave-like unevenness is continuously bent,
a preparatory step for preparing in advance; a brazing material attaching step for providing an amorphous brazing material every other row on the top or valley surface of the corrugated sheet material; and a stop agent on the surface of the corrugated sheet material on which the amorphous brazing material is not provided. a layering step of stacking a plurality of corrugated sheet materials such that the position where the amorphous brazing filler metal is provided is alternately shifted between the upper and lower corrugated sheet materials; A brazing step in which the corrugated sheet material is pressurized and heated and partially joined by brazing, and the joined corrugated sheet material is expanded by applying a tensile force in the stacking direction, thereby forming each cell wall. 1. A method for manufacturing a flexible honeycomb core, comprising: a stretching step of forming a flexible honeycomb core in which each cell is bent in the middle so that each cell has a rounded, substantially convex shape.