JP7245592B2 - Dissimilar metal bonding hollow part manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a dissimilar metal-joined hollow part, which is formed by joining dissimilar metal members having a hollow structure.

2. Description of the Related Art Conventionally, as a shaft having a hollow structure in which dissimilar metals are joined together, there is one disclosed in Patent Document 1. This dissimilar metal joint shaft press-fits and joins the second shaft inside the first shaft having a hollow structure. Therefore, the inner peripheral surface of the first shaft and the outer peripheral surface of the second shaft have a structure in which they overlap in the axial direction.

JP 2017-32131 A

However, since the joining method is press-fitting, there is a problem that shafts having a small thickness cannot be joined together.

SUMMARY OF THE INVENTION The present invention was made in view of the above problems, and an object of the present invention is to provide a method for manufacturing a dissimilar metal-bonded hollow part suitable for manufacturing thin-walled dissimilar-metal-bonded hollow parts.

The above-mentioned problems include a diffusion bonding step of forming a solid-structure dissimilar-metal bonded body by diffusion-bonding a first metal member and a second metal member having a solid structure, and forming a hollow hole in the solid-structured dissimilar-metal bonded body. A method for manufacturing a dissimilar metal-bonded hollow part comprising a cutting step of drilling.

As a pre-process of the diffusion bonding process, a mechanical bonding process of mechanically bonding the solid-structured first metal member and the second metal member is preferably added.

In the mechanical joining step, the convex portion provided at one end of the second metal member is fitted to the concave portion provided at one end of the first metal member, and both members are moved in a direction to increase the fitting strength. Bonding by compression is preferred.

According to the present invention, since hollow holes are formed after diffusion bonding of metal members having a solid structure, it is possible to manufacture hollow parts in which dissimilar metals are bonded together regardless of thickness.

It is a figure which shows the mechanical joining process of the manufacturing method of the dissimilar metal joining hollow component which concerns on this invention. It is a figure which shows the diffusion-bonding process of the manufacturing method of the dissimilar-metal-bonded hollow component which concerns on this invention. It is a figure which shows the cutting process of the manufacturing method of the dissimilar metal joint hollow component which concerns on this invention. FIG. 5 is a view showing another embodiment of a method for manufacturing a dissimilar metal-bonded hollow component according to the present invention;

Hereinafter, a mode for carrying out a method for manufacturing a dissimilar metal-bonded hollow part according to the present invention will be described with reference to the drawings. This manufacturing method includes a mechanical bonding process, a diffusion bonding process, and a cutting process.

FIG. 1 shows a mechanical joining process, which is a process of joining a first metal member 10 made of a copper material and a second metal member 20 made of iron. The first metal member 10 and the second metal member 20 are separately molded and prepared in advance, and are rod-shaped members having a solid structure. The first metal member 10 has a concave portion 11 at one end, and the second metal member 20 has a convex portion 21 at one end.

The concave portion 11 of the first metal member 10 and the convex portion 21 of the second metal member 20 are inserted into the insertion hole 1a of the receiving mold 1 in a state of being fitted. At this time, since the knockout pin 2 is arranged below the insertion hole 1a of the receiving die 1, both members 10 and 20 are positioned.

Subsequently, the punch pin 3, which can be inserted into the insertion hole 1a of the receiving die 1, is advanced downward to compress the first metal member in the axial direction. By plastically deforming in a direction to increase the fitting strength of the fitting portion with the convex portion 21, the members are brought into close contact with each other. In this way, a mechanically joined dissimilar metal joined body A having a solid structure is formed.

Finally, by advancing the knockout pin 2 upward, the dissimilar metal joined body A is ejected from the receiving die.

Next, as shown in FIG. 2, in the diffusion bonding process, the bonded body A bonded in the mechanical bonding process is put into the heating furnace 4 . The heating furnace 4 may have any structure as long as it heats one or a plurality of joined bodies A that have been put in, and the heated furnace 4 is heated at 400 to 500° C. for 2 hours or more, preferably about 4 hours, in an air atmosphere to heat the joined bodies A. It is configured to generate a diffusion layer on the new surface generated at the bonding interface. In this manner, a dissimilar metal joined body A having a solid structure that is diffusion-bonded is formed. In the diffusion bonding process of the present invention, both members are not pressurized in the heating furnace 4, unlike known diffusion bonding.

Finally, as shown in FIG. 3, in the cutting step, the dissimilar metal joined body A taken out from the heating furnace after the diffusion bonding step is perforated by, for example, a machining center (not shown). A through hole 30 is drilled on the center line between the metal member 10 and the second metal member 20 . The through-hole 30 is formed with an inner diameter that allows the protrusion 21 of the second metal member 20 to be completely cut. In this way, a dissimilar metal bonded hollow part is produced.

The holes drilled in the cutting step may be non-through holes.

In the conventional diffusion bonding method, a hot press for diffusion bonding was required as dedicated equipment capable of performing both pressure adhesion and heat treatment between members. On the other hand, according to the above-described method for manufacturing a dissimilar metal bonded hollow component, the first metal member 10 and the second metal body 20 are brought into close contact with each other in the mechanical bonding step, and then put into the heating furnace 4 . Therefore, in the diffusion bonding process, pressure adhesion is not required, and diffusion bonding can be realized in a general-purpose heating furnace.

In addition, in the above-described embodiment, an example of joining two parts was shown, but joining of three parts is also possible. As an example, as shown in FIG. 4, a first metal member 110 made of a copper material, a second metal member 120 made of an iron material, and a third metal member 130 made of steel are all solid bar-shaped members. It is a member. The first metal member 110 has a recess 111 at one end, the second metal member 20 has protrusions 121a and 121b at both ends, and the third metal member 130 has a recess 131 at one end.

First, the concave portion 111 of the first metal member 110 and the convex portion 121a at one end of the second metal member 120 are fitted together, and the convex portion 121b at the other end of the second metal member 120 and the concave portion 131 of the third metal member 130 are fitted together. are inserted into the insertion hole 1a of the receiving mold 1 in a state where they are fitted together, and a dissimilar metal joined body B having a solid structure is formed by the same procedure as the mechanical joining process described above.

Subsequently, the dissimilar metal bonded body B is heat-treated in the same procedure as the diffusion bonding step described above to form a diffusion bonded solid structure dissimilar metal bonded body B.

Finally, by drilling a through hole 140 on the center line of the dissimilar metal bonded body B, a dissimilar metal bonded hollow component is manufactured.

It should be noted that the present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the scope of the present invention.

1 receiving mold 1a insertion hole 2 knockout pin 3 punch pin 4 heating furnace 10 first metal member 11 concave portion 20 second metal member 21 convex portion 30 through hole

Claims (2)

a diffusion bonding step of diffusion bonding the solid-structured first metal member and the second metal member to form a solid-structured dissimilar metal bonded body;
a cutting step of drilling a hollow hole in a solid dissimilar metal joint ;
A dissimilar metal bonded hollow part characterized in that a mechanical bonding step of mechanically bonding a first metal member and a second metal member of a solid structure is added as a pre-process of the diffusion bonding step. Production method. In the mechanical joining step, a concave portion provided at one end of the first metal member is fitted with a convex portion provided at one end of the second metal member, and both members are compressed in a direction to increase the fitting strength. 2. The method for manufacturing a dissimilar metal-bonded hollow part according to claim 1, characterized in that the dissimilar metal-bonded hollow part is bonded by

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