JP3359737B2 - Manufacturing method of honeycomb panel - 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 of manufacturing a honeycomb core for assembling a honeycomb panel used for a vehicle, a building wall material and a floor material by vacuum brazing.

[0002]

2. Description of the Related Art Aluminum alloy honeycomb panels are:
As shown in FIG. 1, a reinforcing material 4 is arranged around a honeycomb core 3, and the honeycomb core 3 and the reinforcing material 4 are sandwiched between a pair of face plates 1 and 2. Then, the honeycomb core 3, the reinforcing member 4, the upper plate 1 and the lower plate 2 are assembled into the shape shown in FIG. 1, and the brazing material is arranged on the joint end or the joint surface thereof, and these are placed in a vacuum chamber. And the members are joined by heating and melting the brazing material.

[0003] As described above, the honeycomb panel has the face plate 1,
2 and honeycomb core 3, honeycomb cores 3, face plates 1 and 2
And the reinforcing material 4, and the honeycomb core 3 and the reinforcing material 4 are joined to each other in one brazing step.

[0004] However, in particular, since the face plates 1 and 2 and the reinforcing member 4 are joined by brazing in a state where the wide faces are in contact with each other, the contact faces cannot be uniformly joined, and local However, there is a problem that it can only be joined.

The reinforcing member 4 is also a member for connecting the panels by welding after the honeycomb panel is assembled by brazing, and the brazing between the face plates 1 and 2 and the reinforcing member 4 is insufficient. If there is, swelling and peeling occur at the time of welding, and the strength of the connection portion cannot be secured after welding, and the strength of the panel becomes insufficient.

As described above, in order to secure the strength of the brazed honeycomb panel made of aluminum alloy,
Although brazing between the face plate and the reinforcing material is extremely important, it can be said that it is difficult to obtain satisfactory brazing strength.

For this reason, in order to improve the brazing property between the face plate and the reinforcing material, a large number of grooves are provided on the surface of the reinforcing material to reduce the contact area between the reinforcing material and the face plate. No. 143668), and a technique of applying a large pressing force during brazing has been proposed, but the brazing properties have not yet been sufficiently improved.

[0008]

As described above, it has been conventionally difficult to uniformly join a wide contact area when brazing between a face plate and a reinforcing member, and therefore, after assembling a honeycomb panel. However, if they are connected by welding, there is a problem that swelling and peeling occur, and that the strength of the connection portion after welding cannot be sufficiently ensured.

The present invention has been made in view of such a problem, and it is possible to increase a bonding area between a face plate and a reinforcing material to improve a bonding strength.
An object of the present invention is to provide a method for manufacturing a honeycomb panel, which can prevent defects such as swelling and peeling from occurring, and can further increase the bonding strength between panels by welding.

[0010]

According to the method for manufacturing a honeycomb panel according to the present invention, a pair of face plates are arranged with a honeycomb core and a rectangular tubular reinforcing material interposed therebetween, and aluminum or aluminum is assembled by brazing. Aluminum alloy
In the method for manufacturing a honeycomb panel, prior to brazing, the joining surface of the reinforcing material with the face plate is subjected to chemical etching or mechanical polishing including a step of using an acid solution as a final treatment to a thickness of 1 μm or more. And oxidized
The film and the Mg-enriched layer are removed .

[0011]

According to the present invention, the surface of the reinforcing member is subjected to chemical etching or mechanical polishing to a thickness of 1 μm before brazing.
It is removed over the above thickness. After this chemical etching or mechanical polishing step, the members are assembled and vacuum brazing is performed. As a result, the brazing area between the face plate and the reinforcing material becomes extremely large, at 80% or more, as a percentage of the area joined by brazing to the contact area, and excellent brazing is obtained.

In vacuum brazing aluminum,
About 1 to 2% of Mg added to the brazing material evaporates from the material during the brazing heating process, and is combined with H ₂ O and O ₂ in the atmosphere and exhausted. As a result, the concentration of H ₂ O and O ₂ in the atmosphere decreases, and the oxidation of the surface where cracks have occurred due to the difference in thermal expansion can be suppressed. Furthermore, the so-called Mg getter function of reducing or altering the aluminum oxide film on the material surface can enhance the wettability of the brazing material,
Thereby, brazing property can be improved.

On the other hand, when the evaporation of Mg is extremely suppressed,
The surface of the aluminum material becomes more active against oxidation due to the presence of Mg, and as a result of the progress of oxidation, brazing properties deteriorate.

In the brazing between the face plate and the reinforcing material, the brazing surface is in a state close to blockage because of the contact in a wide area, and the evaporation of Mg in the brazing material is suppressed. Since the brazing surface is close to clogging, the progress of oxidation of the surface is also suppressed, but since the getter effect of Mg is hardly obtained,
It is considered that the oxide film on the surface remains and sufficient brazing cannot be obtained.

In particular, in brazing the face plate and the reinforcing material,
Although the effect of surface alteration due to Mg is obtained on the surface of the face plate, the effect is hardly obtained on the surface of the reinforcing material. Therefore, it is considered that the oxide film on the surface of the reinforcing material greatly affects the reduction in brazing property.

In the present invention, attention is paid to the oxide film on the surface of the reinforcing material, and by removing the film on the surface of the reinforcing material by chemical etching or mechanical polishing, the oxide film on the surface of the reinforcing material is removed even at the melting temperature of the brazing material. It is intended to suppress the thickness and obtain good brazing properties.

The surface of the reinforcing material is covered with an oxide film. Particularly, in the case of a material containing Mg, M
A g-enriched layer has formed. For this reason, when brazing is performed in such a surface state, these surface films are not broken and the wettability of the brazing material cannot be obtained, so that brazing with sufficient strength cannot be obtained.

On the other hand, in the present invention, before brazing,
The oxide film and the Mg-enriched layer are chemically removed to make the surface of the reinforcing material an extremely thin oxide film. Thereby, the oxide film is easily broken at the time of brazing, whereby good brazing properties can be obtained.

The thickness of the portion to be removed by etching is 1
If it is less than μm, the oxide film can be removed, but Mg
Since the removal of the enriched layer may be incomplete, the thickness of the portion removed by etching needs to be 1 μm or more.

The acid solution is used at least in the final step of the etching in order to remove the Mg-rich layer with the acid solution. Such an Mg-enriched layer cannot be removed with an alkaline solution, and further etching with an alkaline solution causes smut to remain, thereby deteriorating brazing properties.

In the chemical etching step, for example, after etching with an alkali solution, an acid solution may be used as a final treatment, and a treatment with an acid solution may be performed as a final treatment.

[0022]

Next, an embodiment of the present invention will be described. As a face plate, a brazing sheet (thickness: 1.0 mm) in which 6951 material is used as a core material and 4004 brazing material is clad on one surface at a cladding ratio of 10% is used, and the honeycomb core has a thickness of 0.1 mm. Using a brazing sheet of 2 mm, a honeycomb panel was assembled using 6063 material as a reinforcing material, vacuum brazing was performed, and a brazing condition between the face plate after brazing and the reinforcing material was examined by an ultrasonic flaw detection method.

The reinforcing material and the face plate were subjected to a pre-brazing treatment shown in Table 1 below, and then brazing was performed under the following conditions. Brazing conditions; brazing temperature: 280 ° C. (holding for 20 minutes) Heating time: 8 hours Vacuum degree: 8 × 10 ⁻⁵ Torr

[0024]

[Table 1]

However, all the core materials were degreased by immersion in trichloroethane. However, no etching was performed.

In Table 1, NaOH → HNO ₃ is Na
This shows that etching with HNO ₃ was performed after etching with OH. Also, the joint area ratio is determined by examining the entire area of the contact area by ultrasonic flaw detection, and by image processing.
It is calculated as a percentage of the total area of the contact area of the bonding area where the bonding is obtained.

As is clear from Table 1, by removing the surface layer portion of 1 μm or more by chemical etching or mechanical polishing as in the embodiment of the present invention, a bonding area ratio of 90% or more can be obtained. . On the other hand, when the etching thickness of the reinforcing material is 0.5 μm (Comparative Example 7) or when the etching is not performed (Comparative Example 8), the bonding area ratio is 65%.
% And 23%.

[0028]

As described above, according to the present invention, before brazing, the surface of the reinforcing material is chemically etched or mechanically polished by using an acid solution for at least the final treatment. The area ratio (joining area ratio) can be significantly increased. Thereby, the joining strength between the face plate and the reinforcing material can be increased, and the occurrence of defects such as swelling and peeling during welding of the honeycomb panel can be prevented, and the joining strength between the panels can be increased.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a honeycomb panel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1; Top plate 2; Bottom plate 3; Honeycomb core 4;

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshihiko Sasaki 14-1, Chofu Minatomachi, Shimonoseki City, Yamaguchi Prefecture Inside of Kobe Steel's Chofu Works, Ltd. Kobe Steel, Ltd., Chofu Works (72) Inventor Haruo Kato 14-1, Nagafu Minato-cho, Shimonoseki, Yamaguchi Prefecture, Japan Inside of Kobe Steel, Chofu Works (72) Inventor Atsushi Takigawa, 15 Address Kobe Steel, Ltd. Moka Works (56) References JP-A-62-273840 (JP, A) JP-A-5-31574 (JP, A) JP-A-2-303676 (JP, A) JP-A Sho 50-149546 (JP, A) JP-A-5-248031 (JP, A) JP-A-61-291982 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C23F 1/00 -1/46 B21D 47/00 B23K 1/20 B32B 3/12

Claims (3)

(57) [Claims] 1. A method for manufacturing a honeycomb panel made of aluminum or an aluminum alloy, in which a pair of face plates is arranged with a honeycomb core and a rectangular tubular reinforcing material interposed therebetween and assembled by brazing, prior to brazing. The joint surface of the reinforcing material with the face plate is subjected to chemical etching including a step of using an acid solution as a final treatment to obtain 1 μm.
A method for manufacturing a honeycomb panel, comprising removing an oxide film and an Mg-enriched layer by removing over a thickness of at least m. 2. The honeycomb panel according to claim 1, wherein the chemical etching is performed by sequentially performing an etching process using NaOH, a washing process, an etching process using HNO ₃ , a washing process, and a drying process. Production method. 3. A method of manufacturing a honeycomb panel made of aluminum or an aluminum alloy in which a pair of face plates is arranged with a honeycomb core and a rectangular tubular reinforcing material interposed therebetween and assembled by brazing, prior to brazing. Manufacturing a honeycomb panel, wherein a bonding surface of the reinforcing material with the face plate is removed over a thickness of 1 μm or more by mechanical polishing as a final treatment to remove an oxide film and a Mg-enriched layer. Method.