JP2014166646A - Solid-phase welding method for metal workpiece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid-phase welding method for a metal workpiece, which can properly remove a scale and can easily properly weld metal other than iron, such as aluminum.SOLUTION: A solid-phase welding method for a metal workpiece includes the step of pressing a pair of electrodes 3 on the exterior surface of a first metal workpiece 1 in a state where the first metal workpiece 1 is overlapped with a second metal workpiece 2, and energizing the pair of electrodes 3. In the energizing step, a portion heated by the energization is deformed by the pressing force of the electrodes 3 to destroy scales in the surface layers of the first and second workpieces, thereby making the newly-generated surfaces of the first and second workpieces to be weld to each other in a solid phase. Further, in the energizing step, the electrodes 3 are subjected to supersonic oscillation.

Description

  The present invention relates to a solid phase bonding method for metal workpieces.

The present applicant has previously proposed a solid-phase joining method for a metal workpiece called a one-side welding method (see, for example, Patent Document 1).
In this method, in a state where the first and second workpieces made of metal are superposed, a pair of electrodes are pressed from one side of the first workpiece to the outer surface of the first workpiece, and energization is performed between these electrodes. How to do it. At the time of this energization, the place where each electrode is pressed and the vicinity thereof generate heat with resistance heat, and the generated and softened portion is deformed by the pressing force of the electrode. Thus, in the deformed portion, the surface scale of the first and second workpieces (a film covering the new metal surface such as an oxide film) can be destroyed, and the new surfaces can be brought into close contact with each other for solid phase bonding. it can.
According to such a configuration, unlike the normal spot welding, the joint portion of the first and second workpieces is not melted, so that the formation of intermetallic compounds is prevented, the quality of the joint portion is deteriorated, and the joint strength is reduced. It is possible to prevent deterioration. In addition, since the energization by the electrodes can be performed from only one side of the first and second workpieces, workability is good.

  However, the prior art still has room for improvement as described below.

  That is, in the above-described solid-phase bonding method, there is no particular problem when bonding irons to each other, but appropriate bonding is difficult when, for example, iron and aluminum are bonded. The reason for this is that the oxide scale (natural oxide film) on the surface layer of aluminum is strong. Therefore, it is difficult to accurately destroy the oxide scale by simply heating the aluminum by energization to cause pressure deformation. Because. Therefore, it is desired that the solid phase bonding method as described above can be appropriately applied not only to the bonding of irons but also to other metals such as aluminum.

JP 2011-31266 A

  The present invention has been conceived under the circumstances described above, can remove scale appropriately, and can easily and appropriately join metals other than iron such as aluminum. An object of the present invention is to provide a solid phase bonding method for metal workpieces.

  In order to solve the above problems, the present invention takes the following technical means.

In the solid phase joining method for metal workpieces provided by the present invention, a pair of electrodes are pressed against the outer surface of the first workpiece and energized in a state where the first and second workpieces made of metal are overlapped. And having an energization step, and in this energization step, by deforming a portion that generates heat by energization by the pressing force of the electrode, the scale of the surface layer of the first and second workpieces is destroyed in the deformation portion, A solid-phase joining method for metal workpieces, in which the new surfaces of the first and second workpieces are solid-phase joined, wherein the electrodes are ultrasonically vibrated in the energizing step.

  According to such a configuration, a mechanical impact by ultrasonic vibration can be applied to a portion to be joined among the first and second workpieces, and the destruction and removal of the scale can be promoted. For this reason, for example, the oxide scale on the aluminum surface layer, which has been difficult in the prior art, can be appropriately destroyed, and solid phase bonding of metals other than iron, such as solid phase bonding between iron and aluminum, can be realized. On the other hand, when solid phase bonding between irons is attempted, the destruction and removal of the scale is promoted, so that the working time can be shortened and the reliability of solid phase bonding can be improved.

  Other features and advantages of the present invention will become more apparent from the following description of embodiments of the present invention with reference to the accompanying drawings.

(A) is principal part schematic explanatory drawing which shows an example of the solid-phase joining method of the metal workpiece | work which concerns on this invention, (b) shows the state at the time of implementing the solid-phase joining method of (a). It is a principal part expanded sectional view.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

  In the solid phase bonding method for metal workpieces according to this embodiment, as shown in FIG. 1, the first and second workpieces 1 and 2 are stacked one above the other. The first and second workpieces 1 and 2 are both metal plates, and one of these materials is, for example, iron such as mild steel or high-strength steel, and the other is aluminum. Of course, the specific material is not limited to this.

  The pair of electrodes 3 used in the method of the present embodiment is connected to the power supply circuit 4 for energization, and is held by an elevating device (not shown) using a reciprocating cylinder or the like so as to be movable up and down. However, the ultrasonic transducer 6 is connected to the holder portion 30 that holds each electrode 3 via the horn 5, and the ultrasonic vibration generated by the ultrasonic transducer 6 is connected to the holder portion via the horn 5. 30 and the electrode 3 can be transmitted. The vibration direction of the electrode 3 is, for example, the thickness direction of the first and second workpieces 1 and 2.

  In order to join the first and second workpieces 1 and 2, the pair of electrodes 3 is pressed against the outer surface (upper surface) of the first workpiece 1, and energization is performed between the pair of electrodes 3. Along with this, the ultrasonic transducer 6 is driven to ultrasonically vibrate each electrode 3. This ultrasonic vibration is not intended to heat the joining target portion, but is intended to promote scale removal as will be described later.

  When energization is performed between the pair of electrodes 3, a current flows in a region between the pair of electrodes 3 in the first workpiece 1, but the contact portion between each electrode 3 and the first workpiece 1 has a large resistance. For this reason, the vicinity of those contact points generates heat. Since this heat is transmitted also to the 2nd workpiece | work 2, the opposing part of each electrode 3 is efficiently heated among the 1st and 2nd workpieces 1 and 2, and it softens. At that time, the first and second workpieces 1 and 2 are not melted. On the other hand, when each electrode 3 is pressed against the first workpiece 1, the heated portions of the first and second workpieces 1 and 2 are deformed downward as shown in FIG. In the figure, reference numeral 7 denotes a gap between the first and second workpieces 1 and 2. Actually, the gap 7 is considerably small, but is shown in a slightly exaggerated manner in the figure for the sake of understanding.

As described above, when the portions of the first and second workpieces 1 and 2 facing the electrodes 3 are softened by heat generation and are pressed and deformed downward, the first surface and the second workpiece 1 and 2 are elongated.
And the effect | action which destroys the oxide scale which existed in the surface layer of the mutually opposing surface of the 2nd workpieces 1 and 2 is acquired. In this embodiment, since mechanical impact due to ultrasonic vibration is further applied to this part, the destruction action of the oxide scale is further improved, and not only the iron oxide scale but also the oxidation of the aluminum surface layer. It is possible to properly destroy and remove the scale. As a result, the metal surfaces of the first and second workpieces 1 and 2 facing each other are used as new surfaces at locations facing each electrode 3, and these portions are appropriately solid-phase bonded by heating and pressing. can do.

  According to the solid phase bonding method of the present embodiment, it is possible to appropriately solid phase bond the first and second workpieces 1 and 2 made of iron and aluminum, which has been difficult in the past. Since the joining location of the 1st and 2nd workpieces 1 and 2 is not melted, there is no quality deterioration of the joining location.

  The present invention is not limited to the contents of the above-described embodiment. The specific configuration of each part of the solid-phase joining method for metal workpieces according to the present invention can be variously modified within the scope intended by the present invention.

In the above-mentioned embodiment, although the example which joins iron and aluminum is shown, the specific material of the 1st and 2nd work of the present invention is not limited to this. The first and second workpieces may be either the same material or different materials.
As described above, the ultrasonic vibration in the present invention is intended for scale removal by impact. Therefore, the application of the ultrasonic vibration is performed only during a specific period in the joining operation process, for example, limited to a predetermined time after the work target portion of the workpiece is heated to a predetermined temperature or more by energization. You may make it let. The direction of the ultrasonic vibration is preferably the thickness direction of the first and second workpieces, but is not limited to this, and may be, for example, the surface direction of the first and second workpieces.

1, 2 1st and 2nd work 3 Electrode 5 Horn 6 Ultrasonic vibrator

Claims (1)

In a state where the first and second workpieces made of metal are overlapped, an energization step of energizing by pressing a pair of electrodes against the outer surface of the first workpiece,
In this energization step, a portion of the surface layer of the first and second workpieces is destroyed at the deformed portion by deforming a portion that generates heat by energization by the pressing force of the electrode, and the first and second workpieces are destroyed. A solid-phase joining method for metal workpieces, in which the new surfaces are solid-phase joined,
In the energization step, the electrode is ultrasonically vibrated, and the method for solid phase bonding of metal workpieces is characterized.

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