JP2002001549A - Jointing method for die casting product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To joint die casting products with no defect. SOLUTION: In a jointing method for die casting products, a pair of die castings 2 and 2 are jointed by friction stin jointing 31 along an abutted surface 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for joining die cast products, and is used when joining separately cast products.

[0002]

2. Description of the Related Art In a die casting, the core is easily broken because the injection pressure of the molten metal is high. Therefore, conventionally, when casting a member having a shape that is difficult to cast integrally (for example, a closed cross-sectional shape), the target member is divided into a plurality of constituent members, and each of these is die-cast, Thereafter, welding was performed so as to become a target member.

[0003]

Incidentally, in the die casting, since the molten metal is driven at a high pressure together with air, the casting has relatively many pinholes. For this reason, when attempting to join the components cast by die casting using the conventional joining method, the joining portion is melted, so that the effect of the heat causes the surrounding pinholes to be deserted and defects are likely to occur at the joining portion. I had.

An object of the present invention is to eliminate these disadvantages.

[0005]

Means for Solving the Problems In order to achieve this object, in a method for joining a die cast casting according to the present invention, the butting surfaces of a pair of die cast castings are joined by friction stir welding. That is, since a pair of castings are joined in the state of coexistence of each solid and liquid, the joint is less affected by heat than in the past.

[0006]

FIG. 1 is a perspective view showing an embodiment of a method for joining a die cast product according to the present invention.

In FIG. 1, reference numeral 1 denotes a final target member,
It has a closed cross-section that is difficult to cast in one piece. In order to manufacture the final target member 1 by die casting, first, each of the pair of components 2 and 2 is cast by die casting.

Then, these components 2 and 2 are fixed so as not to move while facing each other. 21 is the butt surface.

Reference numeral 3 denotes a rotary tool, and 31 denotes a projection attached to the tip. The rotary tool 3 while rotating about its axis together with the projection 31 (about 800 rpm / s), the rotary tool at a pressure of abutment surfaces 21 to about 750 kg / cm ² of said pair of members 2 Is moved along the abutting surface 21 (in the direction indicated by the mark) while the leading end 31 of the is invading. Then, since the butting surfaces 21 of the two components 2 and 2 are stirred at high speed, the butting surfaces 21 are joined without melting. That is, friction stir welding is performed.

Table 1 shows the tensile strength (Mpa) of the component 2 before and after joining. In addition, the conventional example is a measured value when the constituent members 2 are joined by fusion joining. From this table, it is found that the tensile strength is extremely reduced in the conventional example, whereas the tensile strength is slightly reduced in the present invention.

[0011]

[0012]

In the method for joining die-cast castings according to the present invention, the butting surfaces of the pair of die-cast castings are joined by friction stir welding, that is, the pair of castings are made to coexist with each other. Since the joints are made in the state described above, the joints are less affected by heat than in the past.

Therefore, if this method for joining a die cast product is used, the pinhole in the cast product does not expand, so that a defect-free die cast product can be joined. Further, as shown in Table 1, unlike the conventional method, the mechanical properties of the die cast product are not reduced by the joining.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a method for joining a die cast product according to the present invention.

[Explanation of symbols]

 2… Constituent member (die cast product) 21… Butt surface 3… Rotary tool 31… Projection

Claims (1)

[Claims] 1. A method for joining die-cast products, wherein butting surfaces of a pair of die-cast products are joined by friction stir welding.