JPH071121A - Heat transfer brazing method for hollow metal materials - Google Patents

Abstract

(57) [Summary] [Structure] Outer wall surface 12 of hollow metal member 1 and other metal member 2
The brazing filler metal 3 is interposed at the joint interface with the hollow metal member 1 by melting the brazing filler metal 3 by heat conduction from the heating element 4 to the joint portion.
When joining the other metal material 2 with the other metal material 2, at least a part of the outer peripheral portion of the hollow metal material 1 other than the joined portion is heated,
Join both parts. [Effect] The brazing material can be melted by suppressing the heat radiation from the portion of the hollow metal material other than the joint portion and preventing the heat diffusion from the joint portion. Therefore, even with a hollow aluminum material having a large heat dissipation area, sufficient and good joining can be performed. Moreover, brazing can be performed without being affected by ambient temperature conditions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat transfer brazing method used for joining metal joining members such as aluminum (including alloys thereof), and more particularly to a hollow body when at least one of the joined members is a hollow member. Heat transfer brazing method for metal materials.

[0002]

2. Description of the Related Art For example, as a joining method for partially joining aluminum materials, copper and other electrodes are placed in contact with members to be joined which are placed in a superposed state at a predetermined joining position, and the members to be joined are pressed under pressure. BACKGROUND ART Resistance spot welding is performed in which an electric current is applied to a predetermined joining portion, and resistance heating by the electric current raises the temperature of the joining portion to perform welding. In addition, brazing in the atmosphere such as torch brazing and high frequency brazing is also performed.

However, in the above resistance spot welding method, since the specific resistance of the aluminum material is small,
There are drawbacks such that a large current is required to obtain the amount of heat required for welding and that the electrode dressing interval is shortened because an alloy of copper and aluminum is easily formed at the electrode tip. On the other hand, in the torch brazing method and the high frequency brazing method, it is physically difficult to perform heating and pressurizing at the same time. It had the drawback of being long.

Therefore, as an alternative joining method, a brazing material is interposed at the joining interface, and a heating element is brought into contact with the members to be joined under pressure, and the brazing material is melted by heat conduction from the heating element. Therefore, a heat transfer brazing method for joining both members to be joined has been developed. According to this method, there is an advantage that a wide range of parts can be easily joined in the atmosphere and the energy cost is small.

[0005]

However, at least one of the members to be joined is a hollow member having a hollow portion,
When joining another metal material to the outer wall surface of the hollow portion of the hollow material by heat transfer brazing, there were the following drawbacks. That is, since it is not possible to directly heat the joint from the hollow side and the heat dissipation area is large, the amount of heat escaping from the joint is greater than the amount of heat applied to the joint, especially when the thermal diffusivity is large such as aluminum. In some cases, the brazing filler metal is not sufficiently melted, which makes bonding difficult. Therefore, in reality, joining of such hollow metal materials still depends on torch brazing or the like.

The present invention has been made in view of the above technical background, and uses a heat transfer brazing method when joining another metal material to the outer wall surface of the hollow portion of the metal material having the hollow portion. The purpose is to be able to.

[0007]

In order to achieve the above object, the present invention is directed to a hollow outer wall surface (1) of a hollow metal material (1).
By interposing the brazing filler metal (3) at the joint interface between the 2) and another metal material (2), heat conduction from the heating element (4) to the joint portion
At the time of joining the hollow metal material (1) and the other metal material (2) by melting the brazing material (3), at least a part of the hollow metal material (1) excluding the joining portion on the outer peripheral portion was heated. In the state
The gist is a heat transfer brazing method for a hollow metal material, which is characterized by joining both members.

[0008]

Since the heat radiation from the portion other than the joint of the hollow metal material (1) is suppressed and the heat diffusion from the joint can be reduced, the brazing material can be melted sufficiently and the heat radiation is large. However, sufficient and good joining is performed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will now be described with reference to the drawings. In this embodiment, as shown in FIGS. 1 and 2, the lower wall portion (11), the upper wall portion (12), and the left and right inclined side wall portions (13) and (14) have a trapezoidal hollow portion (15). ) Is formed,
In addition, the flange (16) extends from both left and right ends of the lower wall (11).
The case where the aluminum plate (2) is joined to the outer surface of the upper wall portion (12) of the aluminum hollow member (1) having a hat-shaped cross section in which (17) is formed is shown.

At the time of joining, a brazing material (3) is interposed at the joining interface between the outer surface of the upper wall portion (12) of the aluminum hollow material (1) and the aluminum plate (2). The brazing material (3) should be selected according to the type of metal material to be joined, and the specific type and composition are not limited. In this embodiment, an Al-Si based brazing material having a lower melting point than the members to be joined is used.

Flux is supplied to the joint portion if necessary. The flux may be applied to the surface of the brazing filler metal (3), but in a preferred embodiment, it is preferable to use a flux-containing brazing filler metal that does not require flux application. As an example of the flux-containing brazing filler metal, a powder of an Al alloy containing an element such as Si or Zn, or a powder of a simple substance of these component elements is mixed with a fluoride-based flux or a chloride-based flux. An example thereof is a mixture of the powder mixture that has been hot pressed and then molded into a desired shape by extrusion molding or the like. Further, as a typical composition of such a solid brazing material, A
1, Si, 3 to 15 wt% of Si based on the total content of metal components excluding fluoride flux, the total of elements excluding fluoride flux and fluoride flux. In a weight ratio of 99.9: 0.1-7
The content may be 0:30 and the density is 90% or more of the theoretical value. Further, as the brazing material, a material obtained by mixing and stirring a liquid binder with the above alloy powder or a single powder of the alloy composition and flux powder may be used.

Thus, the brazing filler metal (3) is interposed at the joint interface between the outer surface of the upper wall of the aluminum hollow member (1) and the aluminum plate (2), and then the outer surface of the aluminum plate (2) serves as a heating element. The heater head (4) is placed in contact with each other, and preferably pressure is applied in the direction of pressing the joint surfaces. The heating element is not limited to the one using a heater. Further, a heat source may be incorporated in the heater head (4) itself, or the head may be heated by an external heat source arranged close to the head (4) to generate heat.

On the other hand, below the hollow aluminum material (1), a heating device (5) is arranged closely along the lower wall portion (11) and both side flange portions (16) and (17), and both side flange portions ( The heating devices (6) and (7) are also arranged close to each other above the (16) and (17). These heating devices consist of a hollow aluminum material (1) lower wall (11), both side flanges (16) (1).
7) and part of the side wall parts (13) (14) are heated so that the brazing material (3) is removed from the heater head (4) during brazing.
When the heat conducted to the hollow aluminum material (1) is further conducted to the lower wall portion (11) and the flange portions (16) and (17) of the hollow aluminum material (1), the temperature of both ends of the joint, particularly in the width direction, decreases. This is to prevent the occurrence of heat and, by extension, maintain the temperature of the entire joint uniformly and perform good joining. Also, the effect of ambient temperature is eliminated as much as possible, and brazing is performed under constant brazing conditions. For this purpose, the entire area of the outer peripheral portion of the hollow aluminum material (1), that is, the side wall portions (13) and (14), the lower wall portion (11), and the flange portions (16) and (17) in this embodiment.
Is most preferable, but the effect is recognized even if only a part of the outer circumference is heated. In particular, it is effective to heat the portion with a large amount of heat radiation, and for this reason, in this embodiment, the lower wall portion (11) and the flange portions (16) and (17) were intensively heated.

Thus, the heat of the heater head (4) is applied to the aluminum plate (2) while heating the lower wall portion (11) and the flange portions (16) and (17) by the heating devices (5) to (7).
Is conducted to the brazing filler metal (3), and the brazing filler metal (3) is melted to join the two members. The temperature of the heater head (4) is
Although it may be set according to the types of the members to be joined and the brazing material, it is generally set to about 400 to 1000 ° C. The temperature of the heating devices (5) to (7) is 300 to 550 ° C.
Is set to a degree.

In the above embodiments, the case where the member to be joined is aluminum has been illustrated, but the member is not limited to aluminum. Also, the type of brazing material and flux is not limited.

[0016]

According to the present invention, the brazing filler metal is interposed at the joint interface between the outer wall surface of the hollow metal member and the other metal member, and the heat conduction from the heating element to the joint member causes the brazing filler metal. When melting the material and joining the hollow metal material and other metal material,
Since the two members are joined while heating at least a part of the outer peripheral portion of the hollow metal material excluding the joint portion, it is possible to suppress heat radiation from a portion other than the joint portion of the hollow metal material. As a result, heat diffusion from the joint can be prevented, and the brazing material can be melted sufficiently, so that even a hollow aluminum material having a large heat dissipation area can be sufficiently and excellently bonded. Moreover, brazing can be performed without being affected by the ambient temperature conditions, and a stable bonding state in terms of quality can be realized.

[Brief description of drawings]

FIG. 1 is a sectional perspective view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Hollow aluminum material (hollow metal material) 2 ... Aluminum plate (other metal plate) 3 ... Brazing material 4 ... Heater head (heating element) 5, 6, 7 ... Heating device

Claims (1)

[Claims] 1. An outer wall surface (12) of a hollow portion of a hollow metal material (1)
The filler metal (3) is interposed at the joint interface between the metal and the other metal material (2), and the brazing filler metal (3) is melted by heat conduction from the heating element (4) to the joint portion, thereby producing a hollow metal material ( When joining 1) and another metal material (2), at least a part of the outer peripheral portion of the hollow metal material (1) excluding the joining portion is heated,
A heat transfer brazing method for hollow metal materials, characterized in that both members are joined together.