JPS59127982A - Joining by frictional pressure welding of member of different kind - Google Patents

Abstract

PURPOSE:To form a metallurgically and mechanically strong joint by pressing a projected part provided on the end face of a hard member in the end face of a soft member at the time of frictional pressure welding, and deforming the projected part in the soft member by pressure after pressing in. CONSTITUTION:A concentric annular projected part 2 is provided on the joined end face 1a of a rodlike hard member 1, and a tapered part is formed on the outer periphery of the tip 2b to face the joined end face 3a of a rodlike soft member 3, and pressure welding is performed while rotating them relatively. At this time, the projected part 2 is pressed in the end face 3a of the member 3. At the same time, the member 3 enters the hollow part 2a, and pressure due to the flow of the member 3 presses the tapered part on the outer periphery of the tip 2b and the projected part 2 is swelled out in the middle. A small hole is provided on the bottom of the projected part 2 to discharge air. Thus, a strong joint of combined metallurgical joining and mechanical joining can be obtained. This method is applicable not only to metals of different kind but also to thermoplastic resin.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of joining dissimilar members by friction welding.

Methods such as fusion bonding and solid phase bonding have been attempted to join dissimilar parts, such as dissimilar metals, but in general, joining dissimilar metals produces intermetallic compounds and the joints are brittle. Therefore, solid phase bonding is more advantageous than fusion bonding. Among solid phase welding, friction welding is a highly efficient joining method that provides high joint strength and short joining time, and is suitable for joining dissimilar metals.

However, even when joining by friction welding as described above, for example, in combinations of dissimilar metals such as steel and aluminum alloy, copper alloy and aluminum alloy, etc., even if joining is possible, the strength of the joint may not be sufficient or it may not be usable. There was a problem in that an intermetallic compound layer could be formed inside the joint, resulting in deterioration of joint strength. In addition, as a method for joining dissimilar members, a joint flange stepped portion and four annular portions following this are provided on the outer peripheral side of one member, and the other member is fitted into the one member, and the joining flange stepped portion and the other There is also a method in which the fluid bulge of the other member is butted and friction welded to fill the annular recess (see Utility Model Application Publication No. 50-7365), but in this case, the fluid bulge is attached to its outer periphery. It is not subject to any restraints from the sides, which further increases the joint strength.
Two were desired.

This invention was made with attention to the above-mentioned problems, and it is an object of the present invention to enable strong joining of dissimilar members for which it is difficult to obtain sufficient joint strength by conventional friction welding. For the purpose of This joining method is characterized in that the protrusion is press-fitted into the joining end surface of the soft member, and the protrusion is deformed within the soft member by applying pressure after the press-fitting, thereby joining both members.

The present invention will be explained below based on the drawings.

FIGS. 1(a) to (d) and FIG. 2 are cross-sectional views illustrating the first embodiment of the present invention, in which ■ is a round bar-shaped annular protrusion 2 that is approximately concentric with the joint end surface 1a. a hard member having;
3 is a round rod-shaped soft member having a planar joint end surface 3a.

First, as shown in FIG. 1(a), the joining end surfaces 1a and 3a of both members 1.3 are faced to each other, and when they are pressed together while rotating relative to each other, as shown in FIG. 1(b). Then, the protrusion 2 on the hard member 1 side bites into the joint end surface 3a on the soft member 3 side, and the @:\!! 1 member 3 enters. Next, as shown in Figure 1(c),
When further pressure is applied after the hollow part 2a is filled with the soft member 3, the pressure of the soft member 3 in the hollow part 2a becomes a force that pushes the protruding part 2 outward, and then the first
As shown in Figure (d), the protruding portion 2 is deformed into a shape in which the tip thereof expands outward within the soft member 3.

That is, since the protrusion 2 formed on the hard member 1 is deformed so as to be latched within the soft member 3, the strength is particularly high against tensile force, and the metallurgical bonding force obtained by the normal friction welding method is achieved. It is possible to obtain a strong joint having the mechanical bonding force due to the deformed protrusion 2.

Note that the joint of the joint obtained by this embodiment is as follows:
As mentioned above, it is a high-strength bond that combines metallurgical and mechanical bonding, but as shown in FIG. Since the deformation amount becomes large, there is a possibility that cracks may occur near the joint, which may impair the mechanical joint strength.

Therefore, it is necessary to apply pressure to control the amount of deformation of the protrusion 2.

FIG. 3 and FIGS. 4(a) to (C) are diagrams illustrating a second embodiment of the present invention, and as shown in FIG.
A case is shown in which a tapered portion 2c is formed on the outer peripheral side of the tip portion 2b of the annular protrusion 2 on the joint end surface 1a of the hard member 1.

The hard member 1 and the soft member 3 having the above-mentioned protrusion 2 are joined together by placing the joint end surfaces 1a and 3a of both members 1 and 3 facing each other and subjecting them to relative rotation, as shown in FIG. 4(a). As shown in Fig. 4(b), the hard member l
The protruding portion 2 is press-fitted into the joint end surface of the soft member 3, and the soft member 3 also enters into the hollow portion 2a of the protruding portion 2. At this time, since the tapered part 2C is formed on the outer circumferential side of the tip 2b of the protrusion 2, as shown in FIG. direction), and the tip part 2
Figure 4 (c) has the same effect as fixing b.
), the protrusion 2 after joining becomes a bulge,
The tip portion 2b is deformed into a state where it is rolled inward. Therefore, the same effect as the first embodiment can be obtained, and since the amount of outward deformation of the tip 2b is small due to the tapered portion 2c of the tip 2b, sudden deformation does not occur. The range of appropriate pressure welding conditions can be expanded.

FIG. 5 is a diagram showing a third embodiment of the present invention,
Another example of the shape of the joint end surface will be explained.

In the figure, 4 is a disk-shaped hard member, 5 is a pipe-shaped soft member, and the joint end surface 4a of the hard member 4 has an annular protrusion corresponding to the diameter and wall thickness of the joint end surface 5a of the soft member 5. The portions 4b and 4c are formed double. The tips of both protrusions 4b and 4c also have tapered portions on the outside for the outer protrusion 4b and on the center side for the inner protrusion 4c in accordance with the second embodiment. Parts 4b, 4c
Both the protrusions 4b and 4c are deformed while enveloping the soft member 5 filled with clay between them, and the same effects as in the previous embodiment can be obtained.

FIG. 6 is a diagram showing a fourth embodiment of the present invention, and is for explaining still another example of the shape of the joint end surface.

That is, in the figure, 6 is a hard member that is disk-shaped and has an annular protrusion 6b on the joint end surface 6a, 7 is a soft member that is shaft-shaped and has a planar joint end surface 7a, and the projection 6b is deformed by pressure welding. By doing so, it is possible to obtain the same effect as the above-mentioned embodiment.

In addition, in the first to fourth embodiments of "-", the inside of the hollow part of each protrusion 2.6b or the protrusion 4b.

Since air is sealed between the parts 4c and 4c, a gap is created between the hard member and the soft member after pressure welding, and it may be difficult to obtain metallurgical bonding over the entire surface. Therefore, as shown in FIG. 7, a protrusion 8b formed on the joint end surface 8a of the hard member 8
If a small-diameter through hole 8c is drilled in the root of the joint, the air inside the hollow part 8d will be discharged to the outside by the pressure during welding, and a metallurgical joint will be obtained over the entire surface, improving the strength of the joint. be able to. Further, as shown in FIG. 8, a similar effect can be obtained by forming a hole 8e on the side surface near the tip of the hard member 8, and further forming a through hole 8f communicating with the hole 8e from the bottom surface of the protrusion 8b. be able to.

A joint of dissimilar members obtained by the joining method described in each of the above-mentioned embodiments may be manufactured as a push rod for an automobile engine, for example, and the push rod may have wear resistance. The engine efficiency can be improved by using steel for both ends, which require high efficiency, and by making the shaft part an aluminum alloy for monomerization. In addition, it is possible to jointly form a camshaft in which the cam part is made of wear-resistant steel and the shaft part is made of a thick aluminum alloy. In addition, a combination with a thermoplastic resin may be considered as a different type of member in this invention.

Next, examples of the present invention will be described together with comparative examples. Moreover, FIGS. 9(a) to 9(d) show the shapes of test materials according to comparative examples and examples.

In FIGS. 9(a) to (d), 10-13 is a solid round bar-shaped hard member made of mild steel (JIS, 520C);
0 is also a solid round bar-shaped aluminum alloy (JIS; A
3052), and both members 10
-13.20 are all straight 1'ld = 30mm.

In addition, for comparative examples, as shown in FIG. 9(a),
Each member 1 having conventional planar joint end surfaces 10a and 20a
0.20, as an example, one having a non-tapered protrusion 11b on the joint end surface 11a of the hard member 11 as shown in FIG. 9(b), and the other as shown in FIG. 9(c). As shown, there is also a tapered part 12c on the outside of the tip of the protruding part 12b.
As shown in FIG. 9(d), three types are used: one having a tapered part 13c on the outer peripheral side of the tip of the protruding part 13b and one having a through hole 13d for air discharge at the root. , the dimensions of each of the protrusions 11b, 12b, and 13b are: outer diameter fJdl = 18 mm, inner diameter d2 = 12 mm.
, the length is −10 mm (see (b)). Note that the joint end surfaces 2'Oa of the soft member 20 are both planar.

Next, the friction welding method is a so-called brake method in which the end surfaces are butted against each other and rotated relative to each other to generate heat due to mutual friction, and then they are joined by applying upset pressure, which is axial thrust. Shaft rotation speed 180 Or,
p, m, , preheating pressure 5 kgf/mm2. Upset pressure 1
Pressure welding was carried out under conditions of 0 kgf/mm 2 with several different preheating times for each sample material.

After friction welding, each sample material was subjected to a tensile test, and as a result, the values shown in the following table were obtained.

Note that the soft member 20 is made of aluminum alloy (A505
The tensile strength of 2) was approximately 30 kgf 7 mm2.

As is clear from this table, a joint that is pressure-welded using a hard member that has a protrusion on the joint end surfaces can obtain a tensile strength that is 2 to 3 times that of a joint that is pressure-welded with planar joint end surfaces. did it.

In the examples, mild steel and aluminum alloy were used as the test materials, but it goes without saying that the present invention can also be applied to joining other materials such as aluminum alloy and copper, titanium alloy and aluminum alloy, etc. Further, a combination with a thermoplastic resin is also possible.

As explained above, according to the present invention, when joining dissimilar members by friction welding, an annular protrusion is formed in advance on the joining end surface of the hard member of both γ73 materials, and the two members are moved relative to each other. In the process of pressing the joining end surfaces together while rotating, the protruding portion is press-fitted into the joining end surface of the soft member, and the protruding portion is deformed within the soft member by applying pressure after the press-fitting. Therefore, friction welding is used. In addition to the metallurgical bonding force, it is possible to create a joint that has mechanical bonding force due to the deformation of the protruding portion, and it is possible to create a joint that has mechanical bonding force due to the deformation of the protrusion, and is suitable for dissimilar parts for which it is difficult to obtain sufficient joint strength by conventional general friction welding. This has a significant effect in that a strong bond can be obtained.

[Brief explanation of the drawing]

1(a) to (d) and FIG. 2 are cross-sectional explanatory diagrams sequentially explaining the pressure welding process according to the first embodiment of the present invention, cross-sectional explanatory diagrams in the case of excessive pressurization, FIG. 3, and FIG. 4
Figures (a) to (C) are enlarged cross-sectional explanatory views of a protrusion according to a second embodiment of the present invention and cross-sectional explanatory views sequentially explaining the pressure welding process, and Fig. 5 is an explanatory cross-sectional view of a joining member according to a third embodiment of the present invention. 6 is a sectional view illustrating still another shape example of the joining member according to the fourth embodiment of the present invention, and FIGS. 7 and 8 show that the base of the protruding portion is 9(a) to 9(d) are cross-sectional explanatory views showing the case where air exhaust holes are formed at the bottom, and FIGS. 9(a) to 9(d) show the shapes of the test materials used in the examples according to the present invention. FIG. 4 is a cross-sectional explanatory diagram illustrating dimensions. 1.4, 6, 8, 10, 11, 12.13...hard member, la, 4a, 6a, 8a, 10a. 11a, 12a, 13a... joint end surfaces of hard members, 2
．． 4b, 4c, 6b, 8b, llb, 12b. 13b... Projection portion, 3, 5, 7. 20... Soft member, 3a, 5a, 7a, 20a... Joint end surface of soft member. Patent Applicant Nissan Motor Co., Ltd. Representative Patent Attorney Toyofue Koshio ζM:QJ L/ White Figure 6 Figure 7-8

Claims (1)

[Claims] (1) When joining dissimilar members by friction welding, a process in which an annular protrusion is formed in advance on the joining end surfaces of a hard member among both members, and the joining end surfaces are pressed against each other while relatively rotating the two members. A friction welding method for joining dissimilar members, characterized in that the protruding portion is press-fitted into the joining end surface of a soft member, and the protruding portion is deformed within the soft member by applying pressure after the press-fitting, thereby joining both members. .