JPH04356322A - Electromagnetic joining method for each metallic member having tubular joint part - Google Patents

Abstract

PURPOSE:To improve the reliability of a joined part by fitting tubular joint parts by placing a metallic member whose hardness is low to the inside, placing an electromagnetic coil in the inside of these joint parts and allowing a pulsative large current to flow, and welding by pressure and joining each of both the joint parts. CONSTITUTION:Metallic members 1, 2 having a tubular joint part 1c are joined mutually in its joint part. As for said both metallic members, those which have different hardness are used, and said both tube joint parts are fitted to each other so that the metallic member whose hardness is low become the inside. By placing an electromagnetic coil 3 in the inside of these joint parts and allowing a pulsative large current to flow to this coil, both the joint parts are welded by pressure and joined mutually. In such a way, it is possible to join them in any position, and also, a brazing failure which follows a flux entrapment phenomenon is not generated either, and also, troublesome dew-point management and temperature management, etc., become unnecessary.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is applicable, for example, when a pipe member made of a wrought aluminum alloy is joined to a tubular joint of an intake manifold (AIM) made of an aluminum alloy casting, which is a component of an automobile engine. In addition, there is a method of joining metal members having a tubular joint part, such as an aluminum alloy casting and a co-stretched aluminum alloy material, or an aluminum alloy extrusion material, at the tubular joint part, in particular, a method of joining using electromagnetic force. The present invention relates to a method for electromagnetically joining metal members having tubular joints.

0002

[Prior Art and its Problems] Conventionally, for example, the connection between a tubular joint in an intake manifold (AIM), which is a component of an automobile engine, and a pipe member, etc., was all done by brazing. Ta. However, such brazing has the following problems.

That is, when attempting to braze the joints of metal members to be joined in a horizontal state, the brazing filler metal wraps downward under the joint due to gravity, resulting in poor joining on the upper side of the joint. There is a risk that this may occur. In addition, when this type of brazing is performed by brazing, there is a risk that flux may be caught between the joint parts, resulting in poor joining. Furthermore, the flow phenomenon of the brazing filler metal is controlled by the groove gap between the joints, the surface condition of the joints, etc., and it is somewhat difficult to control this. For these reasons, the reliability of joints formed by brazing has not always been high.

[0004] Furthermore, in the case of brazing, the dew point and temperature of the heating furnace must be strictly controlled, which is somewhat troublesome.

[0005] This invention was made to solve the above-mentioned problems, and it is possible to quickly and reliably join in any posture without using a heating furnace that requires troublesome dew point control or temperature control. It is an object of the present invention to provide a method for joining metal members having tubular joints to each other, which enables the following.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention involves fitting together tubular joints to be connected to each other,
By applying an electromagnetic force from the inner joint part to the outer joint part, the two joint parts are crimped and joined.

That is, the present invention is a method for joining metal members each having a tubular joint at the joint, wherein both metal members have different hardness, and the metal member with lower hardness is on the inside. The tubular joints are fitted together as shown in FIG. The gist of this invention is a method for electromagnetically joining metal members having joints.

[0008] The type of metal of the metal members to be joined, which is the object of the present invention, is not particularly limited, but aluminum and its alloys are preferably used. For example, an aluminum casting with a tubular joint part and the same wrought material,
Alternatively, it can be suitably employed for joining aluminum extrusions together.

[0009] In the present invention, metal members having different hardnesses are used as the metal members to be joined. Then, these tubular joint parts are fitted together so that the metal member with low hardness is on the inside. Next, electromagnetic coils are placed inside these joints, and a large pulsed current is passed through the coils. This pulsed large current can be generated, for example, by storing a large electric charge in a capacitor and instantaneously causing the large electric charge to flow through the electromagnetic coil. Such an instantaneous large current generates a pulsed instantaneous strong magnetic field. This causes an induced current to flow in the surface layer of the inner joint member located outside the coil. Then, a repulsive force acts between this induced current and the current flowing through the coil, and the inner joint part is pressed against the outer joint part by the repulsive force. Here, since the inner joint part has a lower hardness than the outer joint part, the inner joint part is crimped and joined to the outer joint part.

[0010] The shape and arrangement of the electromagnetic coil, and the magnitude and duration of the pulse current flowing through the coil are appropriately set depending on the type of alloy of the metal member and the thickness or hardness of the tubular joint. Thereby, the joint parts to be joined can be reliably joined to each other.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained based on the embodiments shown in FIGS. 1 and 2.

The illustrated embodiment shows a case where an extruded pipe (metal member) (2) made of aluminum alloy is connected to a cylindrical pedestal (metal member) (1) made of aluminum alloy casting.

The cylindrical pedestal (1) has a through hole (1a) in the center along the axial direction, and an enlarged diameter stepped portion (1b) is formed inside the tip. Joint part (
1c). On the other hand, the pedestal (
The extruded pipe (2) to be joined to the pipe (1) has an outer diameter slightly smaller than the inner diameter of the enlarged diameter step (1b) of the through hole (1a), and one end thereof is connected to the joint. Part (2a)
It constitutes.

[0014] The cylindrical pedestal (1) is an extruded pipe (2)
It is made of an aluminum alloy that is harder than the aluminum alloy.

[0015] The joining of the two is performed as follows.

That is, the cylindrical base (1) and the extruded pipe (
2) are arranged horizontally on the same axis, and the joint part (2a) of the extruded pipe (2) is fitted into the joint part (1c) of the pedestal (1). Then, insert the electromagnetic coil (3) from the base end side of the pedestal (1), and connect the coil (3) to the joint part (
1c) Located near (2a). Then, the coil (
A large pulsed current is applied to 3) from an AC high voltage power supply (4). This pulsed large current can also be generated by discharging a large charge stored in a capacitor (not shown) into the coil (3). In this way, a large pulsed current is applied to the coil (3
), a pulse-like instantaneous strong magnetic field is generated, which causes the joint (2) of the extruded pipe (2) near the coil (3) to
An induced current flows in the surface layer of a). Then, a repulsive force acts between this induced current and the current flowing through the coil (3), and as a result, the joint part (2a) of the extruded pipe (2) touches the joint part (1c) of the pedestal (1). They are momentarily pressed toward each other, and the two are crimped and joined. Thereafter, the joining operation is completed by extracting the electromagnetic coil (3).

In the above embodiment, the pedestal (1) and the extruded pipe (2) are joined in a horizontally arranged state, but as shown in FIG. Of course, joining is also possible.

In order to efficiently and reliably join only the joint parts (1c) and (2a), it is effective to concentrate the magnetic flux generated by the electromagnetic coil (3).

[0019] In the above embodiments, the case where a cast material made of an aluminum alloy and an extruded material thereof are joined is explained as an example, but the present invention is not limited to this, and may be applied to any other arbitrary metal member. It can also be applied when joining the buttocks.

[0020]

[Effects of the Invention] As described above, the method of electromagnetic joining of metal members having tubular joints according to the present invention utilizes electromagnetic force to join the tubular joints of metal members by pressure bonding. Since there is no need to consider the flow phenomenon of the brazing material as in the case of brazing, it is possible to join in any position. In addition, since brazing failure due to flux entrainment does not occur, the reliability of the joint can be improved. Furthermore, it is possible to eliminate the need for troublesome dew point control, temperature control, etc. as in the case of brazing.

As described above, according to the present invention, joining can be performed reliably, quickly, and easily in any posture.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the joining method according to the present invention, and is a schematic explanatory cross-sectional view showing a case where joint parts of metal members to be joined are joined in a horizontal state.

FIG. 2 is a schematic explanatory diagram showing, in cross section, a case in which joint parts of metal members to be joined are joined in a vertical state.

[Explanation of symbols]

1...Metal member (pedestal) 1c...Tubular joint part 2...Metal member (extruded pipe) 2a...Tubular joint part 3...Electromagnetic coil

Claims (1)

[Claims] 1. A method for joining metal members each having a tubular joint at the joint, wherein both metal members have different hardnesses, and the metal members having a lower hardness are placed on the inside. The tubular joint parts are fitted together, an electromagnetic coil is arranged inside the joint parts, and a large pulsed current is passed through the coil, thereby crimping and joining the two joint parts to each other. A method of electromagnetic bonding between metal parts.