JPH09234531A - Production of aluminum honeycomb panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain necessary strength for subsequent aging treatment and to reduce temp. difference between the upper and lower face plates so as to reduce thermal strain by clamping a honeycomb core of Ai-Mg-Si base alloy and face plates with upper and lower dies, heating them, brazing them, and then, cooling them at a specific cooling velocity. SOLUTION: A honeycomb structural body composed by assembling upper and lower face plates 14, a honeycomb core 15 and a frame material 16 if necessary is clamped and fixed with upper and lower dies 11, 12 through metal 13 on the upper and lower sides, it is heated in a vacuum or an inert gas in this state, and joined with brazing, succeedingly an air is fed from the upper and lower directions with a fan, and it is cooled rapidly from the temperature of more than 500 deg.C just after brazing to 100 deg.C with the cooling velocity of >=20≡C, <=40 deg.C per minute. Because the upper and lower dies 11, 12 are composed by assembling metal plates in a grid like, the cooling air is well circulated when it is cooled with a fan, because the weight is decreased, the heat capacity is made small, and the cooling of the honeycomb panel is promoted.

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 an aluminum honeycomb panel used for structural members such as railway cars, high-speed ships and buildings, and more particularly to a cooling method after vacuum brazing.

[0002]

2. Description of the Related Art Generally, an aluminum honeycomb panel has a frame member arranged on four sides, a honeycomb core arranged in a region surrounded by the frame member, and sandwiches the upper and lower surfaces of the frame member and the honeycomb core. It is composed of face plates arranged as follows. The honeycomb core and face plate are made of a brazing sheet clad with brazing material in an aluminum alloy,
After the members are assembled in the above arrangement, the members are joined by heating in a vacuum or an inert atmosphere to melt the brazing material. Each of the brazing sheets constituting the honeycomb core has a convex surface and a concave surface along the length direction, and an intermediate surface located between the convex surface and the concave surface alternately and continuously formed in a square wave shape. The convex and concave surfaces of the brazing sheet are superposed to form a honeycomb core composed of a large number of regular hexagonal prism cells.

An example of such an aluminum honeycomb panel is shown in FIGS. 6 and 7. In this figure, 1 is a frame material, 2 is a face plate, and 3 is a honeycomb core. The honeycomb core is formed of a brazing sheet in which a convex surface 3a and a concave surface 3b and an intermediate surface 3c located between the convex surface 3a and the intermediate surface 3c are alternately formed along the length direction and are formed into an angular wave shape. Are brazed together to form a honeycomb core 3. In FIGS. 6 and 7, 4 is for making the pressure in each cell of the honeycomb core 3 equal to the pressure of the external atmosphere at the time of brazing to prevent the occurrence of inconveniences such as deformation of the honeycomb core 3 and defective brazing. (See Japanese Patent Application Laid-Open No. 7-144380).

The aluminum alloy used for the aluminum honeycomb panel desirably has a melting point considerably higher than that of the clad brazing material, and can be strengthened by post-brazing heat treatment in order to increase the fatigue strength of the panel. In general, an Al-Mg-Si alloy is used to satisfy these two requirements.
For example, as the aluminum alloy of the honeycomb core and the face plate, 6951 alloy (Al-0.35Si-0.28C
u-0.6Mg), which has 40
04 alloy (Al-10Si-1.2Mg) is clad, and the aluminum alloy of the frame material is A6N0
1 alloy (Al-0.6Si-0.6Mg) or A606
3 alloy (Al-0.4Si-0.7Mg) is used.

In Japanese Patent Laid-Open No. 4-251624, the assembled aluminum honeycomb panel is vertically clamped by a clamping device composed of a base plate having a lattice structure and a pressure jig, and the aluminum honeycomb panel is placed in a heating furnace. It is disclosed that a method of heating by heating and then cooling by blowing cold air from above and below the pressing device after brazing. Further, looking at the table of the examples of the publication, the cooling rate of the honeycomb panel is 12.5 to
It is 14.3 ° C / min.

[0006]

However, at such a cooling rate, solution treatment becomes insufficient, and even if the aging treatment is performed thereafter, high strength cannot be obtained. Therefore, in order to obtain high strength, new strength cannot be obtained. It is necessary to carry out solution hardening treatment on
There is a problem that the number of heat treatment steps is increased. Further, the above-mentioned publication aims at making the cooling rate uniform, but this is to make the cooling rates of the central portion and the outer side of the base plate side or the pressure jig side uniform, respectively. No attention is paid to the difference. When the honeycomb panel is rapidly cooled while being sandwiched between the pressing devices immediately after brazing, if the cooling rate difference between the upper and lower face plates is large, a large strength difference occurs between the upper and lower face plates, which is not desirable in terms of quality, and thermal distortion occurs in the panel. .

The present invention has been made in view of the above problems, and in a method for manufacturing an aluminum honeycomb panel in which solution treatment is carried out immediately after brazing, obtaining the required strength by subsequent aging treatment, and further The purpose is to reduce the strength difference of the face plate and to reduce the occurrence of thermal strain.

[0008]

The present invention provides a method for manufacturing an aluminum honeycomb panel in which face plates are arranged on the upper and lower surfaces of a honeycomb core, and the honeycomb core and the face plate are integrated by brazing. At least one of them is made of an Al-Mg-Si alloy, which is sandwiched between upper and lower molds composed of metal plates combined in a grid pattern and heated to be brazed, and after brazing, the upper and lower molds are Air is sent from above and below, 50
It is characterized by cooling from a temperature of 0 ° C. or higher to 100 ° C. at a cooling rate of 20 ° C. or higher and 40 ° C. or lower per minute. At this time, preferably, the cooling rate difference between the upper and lower plates of the honeycomb panel is 5 ° C. or less per minute. Further, the above manufacturing method is such that the honeycomb cores are arranged in an outer frame formed by a plurality of frame members, face plates are arranged on the upper and lower surfaces thereof, and the frame member, the honeycomb core and the face plate are integrated by brazing aluminum. It is also applied to honeycomb panels. In that case, at least one of the frame material, the honeycomb core, and the face plate is made of an Al-Mg-Si based alloy.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is applied to an aluminum honeycomb panel in which at least one of a frame material (only when it has a frame material), a honeycomb core and a face plate is made of an Al-Mg-Si alloy. . The Al-Mg-Si alloy is a heat treatment type alloy, and its strength is increased by performing an aging treatment after the solution treatment. In the present invention, cooling from a temperature of 500 ° C. or more immediately after brazing to 100 ° C. at a cooling rate of 20 ° C. or more and less than 40 ° C. per minute means that the solution treatment is performed by this cooling and the strength is increased by the subsequent aging treatment. If the cooling rate is less than 20 ° C. per minute, the strength becomes insufficient. If the cooling rate exceeds 40 ° C., the improvement in strength is saturated and cooling distortion is likely to occur in the mold and panel. Further, in the present invention, the cooling rate difference between the upper and lower face plates is set to 5 ° C. or less because thermal strain occurs in the panel when the cooling rate difference is more than this.

In the method for manufacturing an aluminum honeycomb panel of the present invention, the face plate may take the form of a well-known brazing sheet in which a brazing material is clad in an Al-Mg-Si alloy. Further, the honeycomb core is formed of a plurality of brazing sheets in which a convex surface and a concave surface along the length direction, and an intermediate surface located between the convex surface and the concave surface are alternately continuous and formed in an angular wave shape, and are adjacent to each other. It is possible to take a well-known form in which the convex and concave surfaces of the brazing sheet overlap to form a hexagonal prism cell. In the present invention, the face plate is made of Al-Mg-S.
Although it is preferable that the honeycomb panel is made of an i-based alloy, it is not necessary that all the honeycomb panels be made of the same material. Al-Mg-S
Aluminum alloys other than i-based alloys, such as Al-Mn, which satisfy the condition of having a melting point higher than that of the brazing filler metal.
The A3003 alloy of the system can be used in combination.

1 and 2 show examples of vacuum brazing dies for brazing curved honeycomb panels. The upper die 11 and the lower die 12 are made by combining metal plates in a grid pattern. Each of the lattice-shaped molding surfaces is formed into a curved surface having a desired shape. When using,
Similarly, the upper and lower face plates 14, the honeycomb core 15 and, if necessary, the frame member 1 through the metal plates 13 formed on the curved surface in the vertical direction.
The upper and lower molds 1 of the honeycomb panel structure formed by assembling 6
It is sandwiched and fixed by 1 and 12 (see Fig. 3), and in that state, it is heated in a vacuum or in an inert gas to be brazed and joined, and then air is blown by a fan from above and below to 500 ° C immediately after brazing. Quench from the above temperature. The metal plate 13 may be replaced with a ceramic plate, a carbon sheet or the like.

In the molds 11 and 12, of the metal plates forming the lattice inside the molds, the metal plates 11a and 12a in the vertical direction are used.
Has a width that reaches the rear part of the mold,
Since b and 12b are formed to be short in the height direction and have no width reaching the rear part of the mold, there is a space which is not finely divided by the vertical and horizontal lattices in the rear part of the mold, and therefore, in FIG. When cooled with a fan, the circulation of cool air is good, and the weight is reduced to reduce the heat capacity.
2. The cooling of the metal plate 13 and the honeycomb panel is promoted. The cooling speed can be easily adjusted by adjusting the capacity (wind speed and air volume) of the cooling fan, and the cooling speed can be increased by making the plate thickness as thin as possible to satisfy the required rigidity of the mold and reducing the heat capacity. it can.

4 and 5 show another example of the vacuum brazing die. The molds 21 and 22 have the same structure as the molds 11 and 12 except that they have flat molding surfaces.

[0014]

[Example] A pair of face plates and a honeycomb core (both 695
A curved honeycomb panel structure composed of 1/4004 clad material and having the dimensions shown in Table 1 is sandwiched between upper and lower molds having the structures shown in FIGS. 1 and 2, and the degree of vacuum is 8 × 10 ⁻⁵ Torr.
After holding at the brazing temperature of 580 ° C. for 20 minutes in the vacuum, the sample was cooled to 100 ° C. or lower under various cooling conditions shown in Table 2. At this time, the air volume was the same for the upper and lower fans, and as shown in FIG. 3, consideration was given so that the cold air from the upper and lower fans would hit the honeycomb panel evenly. The air volume shown in Table 2 is the air volume on one side, and the cooling rate is the cooling rate on the face plate on one side. Then 1
Aging treatment was performed at 90 ° C. for 3 hours, and the tensile strength of the face plate was measured. Table 2 shows the results.

[0015]

[Table 1]

[0016]

[Table 2]

As shown in Table 2, in Examples 1 to 3, the tensile strength after aging was 18 kg / mm ² or more and 25 kg / mm ²
However, in the case of Comparative Example 1, it is necessary to further perform solution treatment before the aging treatment in order to secure sufficient strength. In the case of Comparative Example 2, the cooling rate exceeds the regulation of the present invention, but the increase in strength is almost saturated.

Subsequently, as shown in Table 3, the curved honeycomb panel structure having the same composition and size was cooled to 100 ° C. or lower by changing the cooling rate between the upper plate and the lower plate.
The conditions of the brazing and the aging treatment are the same as those in the above-mentioned embodiment, and after the aging treatment, the curvature difference ΔR from the reference gauge of the panel is ΔR.
n and the tensile strength of the upper and lower face plates were measured. Table 3 shows the results. The curvature difference ΔRn means the maximum clearance between the reference surface of the reference gauge G and the outer surface of the honeycomb panel shown in FIG. 8, and a positive value means that the curvature of the honeycomb panel is smaller than the target value. To do.

[0019]

[Table 3]

As shown in Table 3, in the case of Examples 4 to 6,
The strength difference between the upper and lower plates is small and the curvature accuracy is good, but in Comparative Examples 3 and 4, the strength difference between the upper and lower plates is large and the curvature accuracy is remarkably lowered.

[0021]

According to the present invention, since sufficient solution treatment can be performed by cooling immediately after brazing, even if the solution treatment is not carried out separately from brazing as in the conventional case, the subsequent solution treatment is not necessary. The required strength can be obtained by aging treatment. Further, the difference in strength between the upper and lower face plates can be reduced and the panel accuracy can be secured.

[Brief description of drawings]

FIG. 1 is an example of a mold (upper mold) used in the present invention, and is a plan view (a), a sectional view taken along the line AA (b) and a side view (c).

FIG. 2 is a lower mold corresponding to the upper mold, and is a plan view (a), a sectional view taken along the line BB (b), and a side view (c).

[Fig. 3] Fig. 3 is a cross-sectional view illustrating a state in which a honeycomb panel sandwiched by the upper and lower molds is cooled immediately after brazing.

FIG. 4 is another example of the mold (upper mold) used in the present invention, and is a plan view (a), a cross-sectional view taken along the line CC (b) and a side view (c).

FIG. 5 is a lower die corresponding to the upper die, and is a plan view (a), a sectional view taken along the line DD (b) and a side view (c).

FIG. 6 is a partially cutaway perspective view showing an example of an aluminum honeycomb panel.

FIG. 7 is a plan view showing the arrangement of honeycomb cores.

FIG. 8 is a diagram illustrating a method of measuring a curvature difference.

[Explanation of Codes] 11, 21 Upper mold 12, 22 Lower mold 13 Metal plate 14 Face plate 15 Honeycomb core 16 Frame material

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshihiko Sasaki 14-1 Chofu Minatomachi, Shimonoseki City, Yamaguchi Prefecture Kobe Steel Works, Ltd. Chofu Works (72) Inventor Masato Kobayashi 1-5 Takatsukadai, Nishi-ku, Kobe City, Hyogo Prefecture No. 5 Inside Kobe Research Institute of Kobe Steel, Ltd. (72) Shinichiro Takahashi 1-5-5 Takatsukadai, Nishi-ku, Kobe City, Hyogo Prefecture Inside Kobe Research Institute of Kobe Works, Ltd.

Claims (3)

[Claims] 1. A face plate is arranged on upper and lower surfaces of a honeycomb core,
In a method of manufacturing an aluminum honeycomb panel in which a honeycomb core and a face plate are integrated by brazing, at least one of the honeycomb core and the face plate is Al-
A Mg-Si alloy is used, which is sandwiched between upper and lower molds formed by combining metal plates in a grid pattern and heated to be brazed, and after the brazing is finished, air is blown in from above and below the upper and lower molds. 2 minutes per minute from the temperature of 500 ℃ or more immediately after attachment
A method for manufacturing an aluminum honeycomb panel, which comprises cooling to 100 ° C. at a cooling rate of 0 ° C. or higher and 40 ° C. or lower. 2. An aluminum honeycomb panel in which honeycomb cores are arranged in an outer frame formed by a plurality of frame members, face plates are arranged on upper and lower surfaces thereof, and the frame member, the honeycomb core and the face plates are integrated by brazing. In the manufacturing method of, at least one of the frame material, the honeycomb core, and the face plate is made of an Al-Mg-Si-based alloy, and this is sandwiched between upper and lower molds formed by combining metal plates in a grid pattern. After heating and brazing, air is blown in from the vertical direction of the upper and lower molds after the brazing is completed, and the temperature is maintained at 500 ° C or higher immediately after brazing at a cooling rate of 20 ° C to 40 ° C per minute.
A method for manufacturing an aluminum honeycomb panel, which comprises cooling to 0 ° C. 3. The method according to claim 1, wherein the cooling rate difference between the upper and lower plates of the honeycomb panel is 5 ° C. or less per minute.
A method for manufacturing an aluminum honeycomb panel described in 1.