JPH026049A - Method of brazing metallic material - Google Patents

Abstract

PURPOSE:To allow secure brazing of two metallic members by coating paste consisting of brazing filler metal powder having the m.p. lower than the m.p. of an annular brazing filler metal, flux and base material to the section desired to be joined over the prescribed length so as to include at least the uppermost part thereof. CONSTITUTION:Annular solder 60 is fitted onto a main pipe 20 and the open end of the pipe 20 is inserted into the large-diameter part 43 of a throttle body mounting body 40. A liquid suspension is then coated to the part desired to be joined of the main pipe 20 and the mounting body 40 as well as the annular brazing filler metal 60. The paste 61 consisting of the brazing filler metal powder having the m.p. lower than the m.p. of the annular brazing filler metal 60, liquid paraffin as the base material and the fluoride flux is thereafter coated over the angular range inclusive of the uppermost part and 45% central angle around the perpendicular over the entire part desired to be joined at the main pipe insertion side end face of the mounting body 40. Brazing is then executed by heating in a gaseous nitrogen atmosphere. The run-out of the solder is obviated in this way and the good brazing is executed.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a method for brazing metal materials.

In this specification, the term "aluminum" includes aluminum alloys in addition to pure aluminum.

Conventional technology For example, as shown in FIG. 7, a metal tube (100),
Conventionally, when brazing the metal part (101) having a hole (102) into which the end of the metal pipe (100) can be inserted, the end of the metal pipe (100) is conventionally brazed with the metal part (101) having a hole (102) into which the end of the metal pipe (100) can be inserted.
101) into the hole (102), and the metal tube (
100) was fitted and covered with a ring-shaped brazing filler metal.

Problems to be Solved by the Invention However, in products manufactured by brazing a large number of members, there are cases where the metal tube (IQO) must be placed sideways. If brazing is carried out using the conventional method in such a case, when the ring-shaped filler metal melts,
The brazing filler metal over a predetermined length in the circumferential direction including the top part of the entire planned joining area flows down, and as shown in FIG. 7, the outer peripheral surface of the metal tube (100) and the metal part (101)
There was a problem in that the fillet (log) between the end surface of the metal tube insertion side and the planned joining site became small, making it impossible to obtain sufficient brazing strength.

Means for Solving the Problems In the method for brazing metal materials according to the present invention, a ring-shaped brazing filler metal is fitted onto one metal material in a substantially vertical position, and in this state, the metal material is attached to another metal material. When brazing two metal materials by the brazing method in which they are placed in contact with the metal materials, a paste consisting of a brazing powder having a lower melting point than the ring-shaped brazing material, flux, and a base material is applied to the two metal materials. It is characterized in that it is applied over a predetermined length in the circumferential direction so as to include at least the top of the entire area where the materials are to be joined, and then brazed.

In the above, it is preferable that the range to which the paste is applied includes the uppermost part of the entire area to be joined and is within an angular range of 45 degrees centering on a perpendicular line. If the above-mentioned center angle exceeds 45 degrees, the area wetted by the filler metal in the paste at the part where the metal materials are to be joined becomes too wide, and when the ring-shaped filler metal melts, the entire area that is wetted by the molten solder metal in advance becomes This is because there is a risk that it will spread and flow.

Function: According to the method of the present invention, during brazing, the filler metal in the paste is first melted, and this melted solder spreads at least the top portion of the area where two metal materials are to be joined. is wetted over a predetermined length in the circumferential direction, including
After that, when the ring-shaped brazing material melts, it blends into the wetted area and stays there, thereby preventing the molten brazing material of the ring-shaped brazing material from flowing down.

Example Embodiments of the present invention will be described below with reference to the drawings.

Example 1 In this example, the method of the present invention is applied to the manufacture of an automobile intake manifold.

3 and 4 show an automobile intake manifold. The intake manifold (10) has one end open and the other end closed, and has a plurality of holes (21) formed in the peripheral wall and a cylindrical outward protrusion for connecting a branch pipe around the hole (2). A main pipe (20) made of a wrought aluminum material with portions (22) facing in one direction, and a wrought aluminum pipe with each end connected in a fitted state to a cylindrical outward protrusion (22) for connecting a branch pipe. It is equipped with a plurality of branch pipes (30) made of material. A throttle body mounting body (40) made of an aluminum casting is fixed to the open end of the main pipe (20). A throttle body (not shown) is attached to the throttle body attachment (40), and an air supply pipe from an air cleaner is connected to this.

The other end of each branch pipe (30) is connected to a flange (50) for attachment to one aluminum casting cylinder head. For attachment, each branch pipe (30) is connected to a cylinder head of an engine (not shown) via a flange (50).

The main pipe (20) is made from a wrought aluminum material, such as an impact extrusion vibrator or an extrusion vibrator. The closing wall (23) at the other end of the main pipe (20) has an outwardly projecting hemispherical shape, and its inner surface is a concave spherical surface. This can be expected to have a silencing effect. The inner diameter of the branch pipe connecting cylindrical outward protrusion (22) is the same as the inner diameter of the branch pipe (30). Furthermore, an enlarged tube portion (24) having an inner diameter larger than the outer diameter of the branch pipe (30) is integrally formed at the tip of the cylindrical outward protrusion (22).

The branch pipe (30) is made from wrought aluminum, for example an extruded vibrator. Main pipe (20) of branch pipe (30)
One end to be connected to the branch pipe connection cylindrical outward protrusion (
22) It is fitted into the expanded tube part (24) at the tip so that the axes of the two are aligned and is attached to the expanded tube part (24).

For the main pipe (20) and branch pipe (30), for example, J I 5A6063, JISA6061, etc.
It is preferable to use a material made of I5A6000 series aluminum material.

The throttle body mounting body (40) has a cylindrical shape, and is provided with an outwardly projecting flange (41) at one end thereof. As shown in detail in Fig. 4, the through hole (
42) A large diameter portion (43) is provided at the other end over a predetermined length. The inner diameter of the through hole (42) other than the large diameter portion (43) is the same as the inner diameter of the main pipe (20). The inner diameter of the large diameter portion (43) is slightly larger than the outer diameter of the main pipe (20). In addition, the throttle body mounting body (40
) is a cast product, so there is a surface film (45) containing oxides and contaminants on the surface of the as-cast product. (43), the surface of the step (44) between the large-diameter part (43) and other parts of the through-hole (42), and the main pipe (20) on the outer peripheral surface. ) The surface film (45) of a predetermined width portion of the insertion side end is removed. One open end of the main pipe (20) is inserted into the large diameter portion (43) from the end of the throttle body mounting body (40) on the side where the flange (41) is not provided, and the end surface thereof is inserted into the large diameter portion (43). 44) and is brazed to the throttle body mounting body (40). Main manager (2
0) and the throttle body mounting body (40), the brazing material (60) is used to braze the throttle body mounting body (40)
) is interposed between the insertion side end surface of the main pipe (20) and the outer peripheral surface of the main pipe (20).

Although not shown, the brazing filler metal also enters between the inner circumferential surface of the large diameter portion (43) and the outer circumferential surface of the main pipe (20).

The throttle body mounting body (40) is cast without a large-diameter portion (43), and then cut to form a large-diameter portion (43).
43) and a stepped portion (44), and further removes the surface coating (45) on both end faces, the through hole (42), and predetermined portions of the outer peripheral surface.

For attachment to the cylinder head, the flange (50) is made of either a wrought aluminum material or a cast aluminum product. For installation, the flange (50) has a horizontal rectangular shape with 4
It has two holes (not shown) and a cylindrical protrusion (51) for connecting a branch pipe that is integrally provided around the hole. An enlarged tube portion (53) is formed integrally at the tip of the protrusion (51). Further, for mounting, an insertion part (52) for a fuel injection device is provided above the six holes of the flange (50) in one direction. The branch pipe (30) has a protrusion (51)
The tube is inserted into the expanded tube portion (53) of the tube and is brazed.

A specific method for manufacturing such an intake manifold is as follows.

First, the main pipe (20) made of Jl5A6063, which has four holes (21) and four cylindrical outward protrusions for connecting branch pipes (22) with expanded pipe parts (24), JISA6063
AA7 having a through hole (42) with a hairpin branch pipe (30), a flange (41) and a large diameter portion (43).
12.0 throttle body mounting body (40) and a mounting flange (50) having a hole, a protrusion (51), and an insertion part (52) were prepared. Next, the host (20
) and both ends of the branch pipe (30) were cleaned. Further, as described above, after brazing the throttle body mounting body (40), the brazing material (60
In addition to the surface coating (45) on the insertion side end surface of the main pipe (20), the inner circumferential surface of the large-diameter portion (43), and the surface of the step portion (44), which are the parts to be joined that are in contact with the brazing filler metal ( The surface film (45) on the inner circumferential surface of the through-hole (42) and the predetermined portions of the outer circumferential surface that are not to be joined and are not in contact with (60) were also removed.

A surface film (4
The reason for removing 5) is as follows.

In other words, if the surface film (45) on the outer peripheral surface of the throttle body mounting body (40) on the insertion side end of the main pipe (20) is not removed, the molten wax will spread into the brazing material and cause the throttle body mounting body (40) to As a result, this molten solder flows into the space between the surface coating (45) on the outer peripheral surface of the throttle body mounting body (40) and the skin by capillary action, and the melted wax flows into the main pipe (2o) of the main pipe (2o). This is because there is a risk that the amount of solder that should be present at the connection between the throttle body attachment body (40) and the throttle body attachment body (40) is insufficient, resulting in poor brazing.

This phenomenon occurs because the capillary penetration force between the surface film and the bare surface of the casting is greater than the capillary penetration force in the joint gap between the inner peripheral surface of the large diameter part (43) and the outer peripheral surface of the main pipe (20). This is thought to be because it is better. As mentioned above, if the surface film on the outer circumferential surface of the throttle body mounting body (40) is removed, the solder melted in the brazing filler metal will be removed from the outside of the end surface on the insertion side of the main pipe (20) of the throttle body mounting body (40). Even if it spreads to the periphery, it does not reach the surface film. Therefore, the molten solder does not flow between the coating (45°) and the surface, resulting in good brazing. The above-mentioned film removal treatment may be performed by a mechanical method using a grinder, file, machining, brush, etc., or by an electrochemical method.

Next, the main pipe (20) and the mounting flange (50) are arranged so that the cylindrical protrusions (22) and (51) face vertically upward, and one end of the branch pipe (30) is connected to the outside of the main pipe (20). The other end is attached to the tube-shaped protrusion (51) on the flange (50), and the other end is attached to the expanded tube part (24) at the tip of the protrusion (22).
) were respectively inserted into the expanded tube portions (53) at the tips, and the brazing material was placed inside the expanded tube portions (24) (53).

Further, a ring-shaped wax (80) made of J I 5BA4045 was fitted onto the main pipe (20), and the open end of the main pipe (20) was inserted into the large diameter portion (43) of the throttle body attachment (40). Next, 50 wt% fluoride flux,
A suspension consisting of 50 wt% ethanol was added to the main pipe (20).
The mixture was applied to the planned joint portion of the throttle body mounting body (40) and the ring-shaped brazing filler metal (60). After that, #48 to 100, which has a lower melting point than the ring-shaped brazing filler metal, is used.
Metsu's JISBA4047 brazing filler metal powder 40vt%
A paste (6%) consisting of 30vt% liquid paraffin as a base material and 30vt% fluoride flux binder
1) was applied to the end surface of the main pipe insertion side of the throttle body mounting body (40), including the uppermost part of the entire joint area to be joined, and over an angular range of 45 degrees centering on the perpendicular line (see Figures 1 and 2). (see figure). Then, brazing was performed by heating at 605°C for 3 minutes in a nitrogen gas atmosphere with a dew point of -40°C and an oxygen concentration of 50 ppal.

When we examined the brazing parts between the main pipe (20) and the throttle body attachment body (40), we found that there was no breakage in the solder all around, and that they were well brazed.

Further, as shown in FIG. 5, the paste (61) is applied to a ring-shaped brazing material (60) so as to touch both the end surface of the main pipe insertion side of the throttle body mounting body (40) and the outer peripheral surface of the main pipe (20). May be covered and applied.

For comparison, when an intake manifold (10) was manufactured as described above without applying the paste, the main pipe (2
A small fillet was found in a part of the entire circumference of the brazed joint between the throttle body mounting body (40) and the throttle body mounting body (40).

Example 2 In this example, the method of the present invention was applied to the manufacture of a heat exchanger.

FIG. 6 shows a heat exchanger. The heat exchanger (90) includes a pair of headers (91) arranged at a predetermined interval in the left-right direction.
), a plurality of flat tubes made of wrought aluminum (92) arranged vertically at predetermined intervals between both headers (91) and connected to both headers (91〉), and adjacent flat tubes ( 92) Aluminum corrugated fins (93) placed between the two and brazed to the flat tube (92), and a horizontal heat medium inlet tube made of wrought aluminum connected to one header (91). 94) and a heat medium inlet pipe (9
4) and an aluminum casting joint member (95) brazed to the tip. The header (91) consists of an electric resistance welded tube formed from an aluminum plating sheet coated on both sides with brazing material.

In manufacturing such a heat exchanger (90),
The heat medium inlet pipe (94) and the joint member (95) are brazed in the same manner as the main pipe (20) and the throttle body mounting body (40) in the first embodiment.

Effects of the Invention According to the method of the present invention, a paste consisting of a brazing filler metal powder having a melting point lower than that of the ring-shaped brazing filler metal, flux, and a base material is applied to at least the entire area where the two metal materials are to be joined. The paste is characterized in that it is applied over a predetermined length in the circumferential direction, including the topmost part, and then brazed. With this molten solder, the area where the two metal materials are to be joined is wetted over a predetermined length in the circumferential direction, including at least the top part of the entire area, and then when the ring-shaped solder metal is melted, the area where the two metal materials are to be joined is wetted. It adapts to the wet area and stays there, thereby preventing the molten solder of the ring-shaped filler metal from flowing down. Therefore, the formation of a small fillet in the upper part of the joint between the two metal materials is prevented, and as a result, both metal materials are firmly brazed.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 show a first embodiment of the present invention.
The figure is a perspective view showing the method of brazing the main pipe and the throttle body in the intake manifold to the body, Figure 2 is an enlarged sectional view of the same, and Figure 3 is the method of this invention to braze the main pipe and the throttle body to the body. A perspective view of the brazed intake manifold; FIG. 4 is an enlarged sectional view taken along the line IV-IV in FIG. 3;
FIG. 5 is a partially enlarged sectional view showing a modified example of the paste application method, and FIG. 6 shows a second embodiment of the present invention, in which the heat medium inlet pipe and the joint member are attached with solder by the method of the present invention. The front view of the heat exchanger, FIG. 7, is a cross-sectional view of two metal materials brazed together in a conventional manner. (20)...Main pipe, (40)...Throttle body mounting body, (60)...Ring shaped wax, (61)...
・Paste, (94)...heat medium inlet pipe, (95)・
...Joint parts. Figure 1

Claims (1)

[Claims] A ring-shaped brazing filler metal is fitted onto one of the metal materials in an almost vertical position, and in this state, the two metal materials are brazed together by placing the metal material in contact with the other metal material. In this process, a paste consisting of a brazing filler metal powder having a melting point lower than that of the ring-shaped brazing filler metal, flux, and a base material is applied in a circular shape so as to include at least the top of the entire area where the two metal materials are to be joined. A method for brazing metal materials characterized by applying the coating over a predetermined length in the circumferential direction and then brazing.