JPH05104263A - Friction welding method - Google Patents

Abstract

PURPOSE:To join materials having even cross sectional shape except round end surface and also to obtain the high joining strength. CONSTITUTION:To the end surfaces of two materials 10, 10 to be joined, the position having the necessary angle is formed in press-welding direction of the material. Then the materials are relatively reciprocated in the crossing direction to the press-welding direction of the material in the condition of butting the end surfaces of both materials 10, 10. Successively, by press-welding both materials 10, 10 in the axial direction at the timing when both end surfaces soften with the friction heat, both materials 10, 10 are joined.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction welding method, and more particularly, it relates to a friction welding method capable of joining materials having a joining end surface other than a circular shape and improving the joining strength. It is a thing.

[0002]

2. Description of the Related Art A friction welding method is known as a method for joining materials of the same kind or different kinds of materials to each other. This method is suitable for joining important parts in, for example, automobiles and machines, because it has advantages such as high joining accuracy, easy control during joining work, and excellent economical efficiency.

An outline of this friction welding method will be described. As shown in FIG. 10, first, the materials 10, 10 to be joined are to be joined.
The end faces of the above are abutted against each other, and one material 10 is rotated under a constant pressure (a). Due to the rotation of the material 10, frictional heat is generated between the contact surfaces (end surfaces), and the material ends gradually soften (b). Then, when both the materials 10 and 10 are in an appropriate softened state, the rotation of the material 10 is stopped and the required pressure force in the axial direction is applied to the both materials 10 and 10 to To perform pressure welding
(c).

[0004]

In the friction welding method described above, frictional heat is generated at the contact surface of the material 10 by relatively rotating the material 10. Therefore, at least one of the end surfaces of the material 10 is heated. Has a drawback that it is limited to a circle that is point-symmetric with respect to the center of the material. Therefore, it cannot be used for joining materials having irregular cross-sections such as rails whose end face shape is not point-symmetric with respect to the center of the material. For this reason, flash butt welding, thermite welding, etc. are used for joining rails, but the former limits the installation location of the welding equipment because sparks are scattered around it, and interferes with work near the equipment. In the latter case, the welding work is complicated and the work efficiency is lowered.

Here, when observing the internal structure of the joint where the rolled and formed rods are joined by the friction welding method, FIG.
It can be seen that the structure flows in the diametrical direction of the material 10 (direction parallel to the end face) as shown in FIG. In this case, the rolled material has a lower strength with respect to a load parallel to the flow direction of the structure, as compared with a strength with respect to a load in a direction orthogonal to the flow direction of the structure (rolling direction). For example, when the Charpy impact test is performed on the bonding material, the impact value orthogonal to the tissue flow direction shows a high value, while the impact value parallel to the tissue flow direction shows a low value. .. That is, it has been pointed out that the materials joined by the conventional friction welding method have inferior strength at other joints than the other portions and may be broken or cracked from the joints.

[0006]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above-mentioned drawbacks inherent in the friction welding method described above, and is proposed in order to suitably solve the drawbacks. Materials other than circular end faces can also be joined together. It is an object of the present invention to provide a friction welding method capable of obtaining high joining strength.

[0007]

[Means for Solving the Problems] Overcoming the above-mentioned problems,
In order to preferably solve the intended purpose, the present invention provides a method in which the end surfaces of two materials to be joined are abutted against each other and friction is applied, and when both ends thereof are softened by friction heat, the two materials are axially joined. In the friction welding method in which the welding is performed by pressing in the direction, the abutting end faces of the both materials are formed with a portion capable of contacting each other at a predetermined angle with respect to the welding direction of the materials, With both materials abutting their end faces,
It is characterized in that the material is frictionally welded by relatively reciprocating in a direction intersecting the material pressure welding direction.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a friction welding method according to the present invention will be described below with reference to the accompanying drawings with reference to preferred embodiments. In this specification, the “material pressure contact direction” refers to a direction parallel to the direction of the pressure applied to the materials to be joined.

FIG. 1 is a schematic constitutional view of an apparatus capable of suitably carrying out the method according to the present invention.
A movable frame 12 for fixing 0 is slidably mounted on a base 14, and the movable frame 12 is configured to reciprocate in a direction orthogonal to the material pressure contact direction. That is, the movable frame 12
One end of the first connecting rod 16 is rotatably supported at one side thereof, and the other end of the first connecting rod 16 is rotatably supported at one end of the second connecting rod 18. Further, at a position deviated from the rotation center of the disk 22 rotated in a predetermined direction by the motor 20,
The other end of the second connecting rod 18 is rotatably supported. Therefore, by driving the motor 20, the movable frame 12 reciprocates along the base 14 via the disc 22, the second connecting rod 18, and the first connecting rod 16.

A fixed frame 24 for fixing the other material 10 is disposed at a position opposed to the movable frame 12 in the material pressure contact direction, and the fixed frame 24 moves forward and backward with respect to the movable frame 12 in the material pressure contact direction. It is freely configured. That is, both frames 1
As shown in FIG. 2A, the opposing end faces of the materials 10 and 10 fixed to 2 and 24 can be abutted with each other in a state where their phases match. As shown in the drawing, the end surface of the material 10 is linearly inclined at a required angle with respect to the material pressure welding direction over the entire length of the height dimension of the material 10. However, it goes without saying that the inclination directions of the materials 10 facing each other are set to correspond to each other. In the embodiment, as the material 10 to be frictionally joined, a rail that is not point-symmetric with respect to the center of the material is used.

At the end of the fixed frame 24 separated from the movable frame 12, a hydraulic cylinder 26 is provided at a fixed portion (not shown).
Piston rod 26a of the hydraulic cylinder 2 is connected.
6 functions to apply a pressing force that presses the end faces of the materials 10, 10 fixed to both frames 12, 24. The hydraulic cylinder 26 is set so that the frictional pressure applied when the materials 10 and 10 are rubbed and the setup pressure applied when joining can be switched.

[0012]

Next, the operation of the friction welding method according to the present invention, which is carried out by operating the apparatus according to the embodiment, will be described. As shown in FIG. 1, one material 1 to be joined
0 is positioned and fixed to the movable frame 12, and the other material 10 is fixed to the fixed frame 24 so that the end surfaces of both materials 10 and 10 face each other. As shown in FIG. 2A, the end surfaces of both materials 10, 10 are formed so as to incline in a direction corresponding to the material pressure contact direction. Next, the fixed frame 24 is advanced to bring the end surfaces of the opposing materials 10 and 10 into contact with each other, and the hydraulic cylinder 26 is urged to apply a friction pressure between both end surfaces.

In this state, by driving the motor 20 to rotate the disk 22 in a predetermined direction, the movable frame 12 is moved to the base 1 through the second connecting rod 18 and the first connecting rod 16.
4, the contact end faces of both materials 10 and 10 are softened by frictional heat. The reciprocating movement of the movable frame 12 brings the contact end surfaces of the materials 10 and 10 into an appropriate softened state, and when the material 10 of the movable frame 12 and the material 10 of the fixed frame 24 are in phase with each other, the motor 20 Stop control. Next, the hydraulic cylinder 26 is urged to apply a setup pressure between the end faces of the two materials 10 and 10, so that the end faces come into pressure contact with each other to be joined as shown in FIG. 2B.

Observing the flow direction of the tissue at the joint portion of the materials 10 and 10 according to the first embodiment joined as described above, as shown in FIG. 3, the tissue is in the direction along the end face.
(The material 10 is a rolled material) flowing in a direction (inclined by a required angle with respect to the material pressure welding direction). That is, since the tissue is inclined with respect to the load from the direction orthogonal to the material pressure welding direction, the stress applied to the joint can be dispersed and the joint area can be increased, so that high strength can be obtained. .. As a result, the method can be sufficiently applied as a joining method for members that require high strength such as rotational twisting, bending and pulling.

Experimental Example A material 10 having an end face shape as shown in the first embodiment was joined by a friction joining method according to the present invention, and a Charpy impact test (U notch) in a direction orthogonal to the material pressure welding direction was conducted. The results obtained are shown below. Note that carbon steel is a rolled material and Mn steel is a cast material. In addition, the Charpy impact value is shown with reference to the impact value of a material obtained by joining materials whose end faces are orthogonal (perpendicular) to the pressing direction.

[0016]

As described above, the impact value of the joining material having the inclined end faces was higher than the impact value of the joining material obtained by joining the materials of the end faces orthogonal (right angle) to the material pressure welding direction. Further, it was found that the impact value was higher when the end face was inclined, regardless of whether the materials to be joined or the molding method were the same or different. The inclination angle of the material end face is 3 ° to 5 ° with respect to the direction orthogonal to the press contact direction.
If it is above, a high impact value can be obtained.

(Regarding another embodiment of the end face shape of the material) The end face shape of the material 10 is limited to the one which is linearly inclined over the entire length in the height direction of the material 10 as in the first embodiment. Instead of this, a partially inclined shape can be appropriately adopted. For example, in the second embodiment shown in FIG. 4, the end surface of one material 10 is formed in an arc shape projecting outward, and the end surface of the other material 10 is formed in an arc shape that is drawn inward. In this case, by abutting the two materials 10 and 10 together, as shown in FIG. 5, both end surfaces thereof abut in an arcuately inclined state with respect to the material pressure welding direction. In this state, one material 10 is reciprocated in the direction of the arrow in FIG. That is, in the direction of reciprocal movement, the butt end faces are always the same. Further, in the third embodiment shown in FIG. 6, the end surface of the material 10 is formed in an inverted S shape, and the joining area is set to be large.

Next, in a fourth embodiment shown in FIG. 7, a protrusion 28 whose upper surface is inclined downward is formed at the lower end of one material 10 and at the upper end of the other material 10 is formed. A protrusion 28 whose lower surface is inclined upward is formed. Then, the upper and lower inclined surfaces of the both protrusions 28, 28 are frictionally pressure-contacted with each other in a state of being in contact with each other, whereby the both inclined surfaces can be firmly joined. In addition, in the fifth embodiment shown in FIG. 8, a wedge-shaped protrusion 30 is formed at the center of the end of one material 10, and a recess 32 corresponding to the wedge-shaped protrusion 30 is formed at the end of the other material 10. Has been formed. Therefore, in this embodiment, by inserting the wedge-shaped protrusion 30 into the recess 32, it is possible to firmly bond the two materials 10, 10 on the upper and lower inclined surfaces of the wedge-shaped protrusion 30. Furthermore, in the sixth embodiment shown in FIG. 9, both materials 10, 1
By forming the wedge-shaped protrusions 30 and the recesses 32 corresponding to the wedge-shaped protrusions 30 at the end portions of 0 respectively, both materials 10, 10
It is possible to achieve a strong joint of

In the embodiment, the case where the movable frame for fixing the material is reciprocally moved through the crank mechanism has been described. However, the number of connecting rods in this case need not be two as in the embodiment, but only one. You can Further, the present invention is not limited to the crank mechanism, and for example, the movable frame may be moved (vibrated) using ultrasonic waves. Further, the surrounding atmosphere may be not only the atmosphere but also an inert gas.

[0021]

As described above, according to the friction welding method according to the present invention, even if the end surfaces of the materials to be joined are not circular in shape, friction joining can be suitably performed. Also, since the joining surface (end surface) of the material has a required angle with respect to the material pressure welding direction, it is possible to disperse the stress when a load orthogonal to the pressure welding direction is applied, and to increase the welding area. Since it is possible to earn money, there is an advantage that the strength of the joint can be increased.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an apparatus capable of suitably implementing a friction welding method according to the present invention.

FIG. 2 is an explanatory diagram showing a material according to the first embodiment.

FIG. 3 is an explanatory diagram showing an internal structure of the materials according to the first embodiment after being joined.

FIG. 4 is an explanatory perspective view showing a material according to a second embodiment.

FIG. 5 is a sectional view of a material according to a second embodiment.

FIG. 6 is a sectional view of a material according to a third embodiment.

FIG. 7 is a sectional view of a material according to a fourth embodiment.

FIG. 8 is a sectional view of a material according to a fifth embodiment.

FIG. 9 is a sectional view of a material according to a sixth embodiment.

FIG. 10 is an explanatory diagram showing a step of joining rod-shaped materials by a friction welding method according to a conventional technique.

FIG. 11 is an explanatory diagram showing an internal structure of materials joined by a friction welding method according to a conventional technique.

[Explanation of symbols]

 10 Material 12 Movable Frame 14 Base 16 First Link Rod 18 Second Link Rod 20 Motor 22 Disk 24 Fixed Frame 26 Hydraulic Cylinder

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[Procedure amendment]

[Submission date] November 25, 1991

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

Claims (1)

[Claims] 1. When the end faces of two materials to be joined are abutted against each other and friction is applied, and when both ends are softened by frictional heat, the two materials are axially pressure-welded to perform the joining. In the friction welding method described above, a part that can abut against each other is formed on the abutting end faces of the both materials at a required angle with respect to the press contact direction of the materials, and the both faces are abutted with each other. In this state, the material is frictionally welded by relatively reciprocating the material in a direction intersecting the material pressure welding direction.