Metal material, welded metal material, and welding method

Abstract

To provide a metal material configured so that sputter is suppressed from jumping thereinto, a welded metal material welded so that sputter does not adhere thereto, and a welding method that can perform welding while preventing sputter from adhering to the metal material.SOLUTION: The metal material has a penetration hole penetrating through front and rear surfaces of the metal material, which is high enough to prevent sputter generated when the metal material is welded to the other metal material from jumping into the penetration hole, in which a protrusion is formed around the penetration hole, where the protrusion protrudes to the front surface of the metal material. In the welded metal material, a welding protrusion is formed at a rear surface of a head part of a weld bolt, which is an outer periphery of a screw shaft, and a recessed part is formed between a root side of the screw shaft and the welding protrusion, where the recessed part is formed wide and deep enough to prevent the protrusion from contacting the rear surface of the head part of the weld bolt. In the welding method, the screw shaft of the weld bolt is inserted into the penetration hole of the metal material, the welding protrusion formed on the rear surface of the head part of the weld bolt is contacted with the metal material, the protrusion formed around the penetration hole is stored in the recessed part formed on the rear surface of the head part of the weld bolt to prevent the protrusion from contacting the rear surface of the head part, and electricity is distributed to the metal material and the weld bolt to weld the metal material to the welding protrusion of the weld bolt.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to metal materials to be welded, welded metal materials to which metal materials have been welded, and a method for welding metal materials. [Background technology]

[0002] It is common to weld two or more metal materials together using spot welding, arc welding, laser welding, or other welding methods. One example is welding a weld bolt to a metal plate (see Patent Document 1). As shown in Figure 4, this welding method involves inserting a weld bolt C into a through hole B that penetrates the front and back surfaces of metal plate A, bringing a welding protrusion E protruding from the back surface of head D of weld bolt C into contact with metal plate A, and then passing a welding current through weld bolt C and metal plate A, causing the resulting Joule heat to melt and weld weld the weld protrusion E and metal plate A.

[0003] In the above-mentioned welding, spatter can be generated when welding metal plate A to weld projection E of weld bolt C, and this spatter can fly into through hole B in metal plate A and adhere to the screw shank F of weld bolt C inside through hole B. Spatter adhesion occurs not only when welding weld bolt C to metal plate A, but also when welding a metal material such as a nut to metal plate A. In this case, spatter can adhere to the threads of the nut, making it impossible to screw the bolt onto the nut. In addition, spatter generated during welding can adhere to other metal materials near the metal material being welded, making the metal material unusable. The adhesion of scattered spatter can occur not only in spot welding, but also in other welding processes. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 09-047884 Summary of the Invention [Problem to be solved by the invention]

[0005] The problem to be solved by the present invention is to provide a metal material that can solve the problem caused by spatter intrusion, a welded metal material, and a welding method that can prevent spatter adhesion. [Means for solving the problem]

[0006] The metal material of the present invention may be of any shape or structure as long as it is weldable, but the following description will be given as an example of a case in which one metal material is plate-shaped and the other metal material is a weld bolt.

[0007] One of the metal materials has a through hole that penetrates the front and back surfaces, with protrusions around the through hole. The protrusions are to prevent spatter from entering the metal material, and are protruding from the surface of the metal material at a height that prevents spatter generated when welding with the welding protrusions of the weld bolt, which is another metal material, from entering the through hole.

[0008] The other metal material is a weld bolt, which has weld protrusions at several points around the periphery of the backside of the head, and a recess between the outside of the base of the screw shaft and the weld protrusions. The recess is for protrusion contact avoidance, preventing the protrusions on the outer periphery of the through hole in the metal material from coming into contact with the backside of the head of the weld bolt (making it non-contact), and is sized in width and depth so that the protrusions do not come into contact.

[0009] The welded metal material of the present invention is obtained by welding a plate-shaped metal material to a weld bolt (the other metal material) with a screw shaft inserted into a through hole in the metal material. In this case, a protrusion (hereinafter simply referred to as a "protrusion") for preventing spatter from flying in, provided on the outside of the through hole in the metal material, is housed in a protrusion contact avoidance recess (hereinafter simply referred to as a "recess") of the weld bolt, thereby avoiding contact with the head of the weld bolt (maintaining non-contact).

[0010] The welding method of the present invention is a method for welding a metal material having a protrusion on the outer periphery of a through hole to a weld bolt having a recess, in which the weld bolt's threaded shaft is inserted into the through hole of the other metal material, and the weld protrusion on the back surface of the head is brought into contact with the outside of the protrusion on the outside of the through hole, thereby welding the metal material and the weld bolt. [Effects of the Invention]

[0011] The metal material of the present invention has the following effects. (1) The protrusion on the outside of the through hole prevents spatter from flying into the through hole, and spatter does not adhere to the threaded shaft of the weld bolt inserted into the through hole, so that the nut can be screwed onto the threaded shaft. (2) Because there is a recess on the back of the head of the weld bolt, even when the threaded shaft of the weld bolt is inserted into a through-hole in a metal material with a protrusion, the protrusion does not come into contact with the bolt (contact is avoided and it becomes non-contact). As a result, the current flowing between the metal material and the welding protrusion of the weld bolt does not flow (be shunted) to the protrusion, and the current density does not become insufficient, resulting in weak heat generation and insufficient welding.

[0012] The welded metal material of the present invention has the following effects. The screw shaft of the weld bolt is inserted into a through hole in a metal material with a protrusion and welded, and since no spatter adheres to the screw shaft, the nut can be securely screwed onto the screw shaft.

[0013] The welding method of the present invention has the following effects. The threaded shaft of the weld bolt is inserted into a through hole in a metal material that has a protrusion on the outside of the through hole for welding, so even if spatter is generated when welding the metal material and the weld bolt, the spatter cannot enter the through hole and can be welded without adhering to the threads of the screw material. Also, because the protrusion is positioned within the recess of the weld bolt and welding is performed without contact with the head of the weld bolt, the current flowing between the metal material and the welding protrusion of the weld bolt is not diverted to the protrusion, and there is no insufficient current density that results in weak heat generation and insufficient welding. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 2 is an explanatory diagram of a weld bolt according to the present invention. [Figure 2] 1 is an explanatory diagram of a welding method according to the present invention; [Figure 3] 10(a) to 10(c) are partial cross-sectional views of different examples of recesses in a weld bolt and protrusions in a plate-shaped metal material. [Figure 4] Explanatory diagram of conventional welding method DETAILED DESCRIPTION OF THE INVENTION

[0015] (Embodiment of Metal Material) The two metal materials to be welded in the present invention may be of any shape. For example, one metal material may be a flat metal plate or a metal plate formed by pressing a flat metal plate into various shapes (hereinafter referred to as a "plate-shaped metal material"), and the other metal material may be a metal part such as a weld bolt or a bolt or nut of another shape. In the following embodiment, one metal material is a plate-shaped metal material 1 (FIG. 2) and the other is a weld bolt 2 (FIG. 1).

[0016] [Metal plate material] The plate-shaped metal material 1 in Figure 2 has through-holes 3 that penetrate both the front and back surfaces, with protrusions 4 around the holes to prevent spatter from entering. The through-holes 3 are of a size that allows the screw shaft 5 of the weld bolt 2 to be inserted, and may be a circular hole, a horizontally elongated hole, or any other shape.

[0017] The protrusions 4 prevent spatter generated when spot welding the plate-shaped metal material 1 and the welding protrusions 6 of the weld bolt 2 inserted into the through hole 3 from flying into the through hole 3. The protrusions 4 can be provided in a ring shape around the entire outer circumference of the through hole 3, or they can be provided discontinuously around the through hole 3 at locations inside the weld bolt 2 inserted into the through hole 3.

[0018] The cross-sectional shape of the protrusion 4 can be a tapered, pointed shape as shown in Fig. 2, a rectangular shape with a square tip as shown in Fig. 3(a), an arc shape with an arc-shaped tip as shown in Fig. 3(b), a sloped tip with a downward slope from the outside to the inside as shown in Fig. 3(c), or any other shape. In any case, the shape and height are designed to prevent spatter from flying into the through-hole 3.

[0019] The protrusions 4 can be formed when the through holes 3 are drilled in the plate-shaped metal material 1, or can be formed in a separate process. In either case, as shown in Figures 3(a) to 3(c), the back side peripheral portion 9 (Figures 3(a) to 3(c)) of the through holes 3 is pressed to push the front side peripheral portion of the through holes 3 upward beyond the through holes 3, thereby forming the protrusions 4.

[0020] [Weld Bolt] As shown in Figure 1, the weld bolt 2 has a head 7 and a screw shaft 5. There are weld protrusions 6 at several locations (three locations in Figure 1) around the circumference of the back surface of the head 7, and there is a recess 8 (Figures 1 and 2) between the outside of the base of the screw shaft 5 and the weld protrusions 6 to prevent contact with the protrusions.

[0021] The welding projections 6, like the welding projections of a general-purpose weld bolt, generate Joule heat when electricity is passed through them, and are welded to the plate-shaped metal material 1.

[0022] 1 and 2, the recess 8 is provided on the back surface of the head 7, outside the base of the screw shaft 5 and inside the weld projection 6 (between the screw shaft 5 and the weld projection 6). The recess 8 in FIGS. 1 and 2 is a ring-shaped circular groove provided around the entire periphery of the back surface of the head 7.

[0023] The recess 8 prevents the protrusion 4 from contacting the back surface of the head 7 of the weld bolt 2 when the screw shank 5 of the weld bolt 2 is inserted into the through hole 3 of the plate-shaped metal material 1, as shown in Figure 1. The recess 8 does not necessarily have to be provided around the entire back surface of the head 7, but can also be provided partially between the screw shank 5 and the welding protrusion 6. Whether provided around the entire circumference or partially, the recess 8 has a shape and depth that allows the protrusion 4 to fit without contacting (non-contacting) the back surface of the head 7 of the weld bolt 2. Furthermore, the recess 8 does not have to be a ring-shaped groove, and may be, for example, a hole, a short ring-shaped depression, or some other shape.

[0024] (Embodiment of welded metal material) The welded metal material of the present invention is obtained by welding two metal materials, for example, a plate-shaped metal material 1 and a weld bolt 2, as shown in FIG.

[0025] 2 is spot-welded by inserting the threaded shaft 5 of the weld bolt 2 into the through hole 3 of the plate-shaped metal material 1 and bringing the weld protrusion 6 of the weld bolt 2 into contact with the surface of the plate-shaped metal material 1. In this case, the protrusion 4 of the plate-shaped metal material 1 is accommodated (placed) in the recess 8 on the back surface of the head 7 of the weld bolt 2 so as not to come into contact with the back surface of the head 7.

[0026] (Embodiment of welding method) The welding method of the present invention is a method for welding two metal materials, and as an example, a method for welding a plate-shaped metal material 1 and a weld bolt 2 as shown in FIG. 2 by spot welding or other welding methods.

[0027] In the present invention, spot welding can be performed as follows. (1) The threaded shaft 5 of the weld bolt 2 is inserted into the through hole 3 of the plate-shaped metal material 1, and the welding protrusion 6 of the weld bolt 2 is brought into contact with the surface of the plate-shaped metal material 1. In this case, the protrusion 4 of the plate-shaped metal material 1 is housed in the recess 8 on the back surface of the head 7 of the weld bolt 2 so that the protrusion 4 does not come into contact with the back surface of the head 5. (2) In the contact state of (1), the head 7 of the weld bolt 2 and the plate-shaped metal material 1 are clamped with welding electrodes and pressure is applied, and electricity is passed between the two metal materials to generate Joule heat at the contact point between the welding protrusion 6 of the weld bolt 2 and the plate-shaped metal material 1, and the heat melts and joins the contact point (welds it).

[0028] In the above welding method, even if spatter occurs during welding, the protrusions 4 prevent the spatter from entering the through hole 3, and therefore the spatter does not adhere to the screw shaft 5 of the weld bolt 2. [Industrial Applicability]

[0029] Because the present invention prevents spatter generated during welding from adhering to metal materials, the metal materials to be welded are not limited to plate-shaped metal material 1 and weld bolt 2, but may be metal materials of other shapes and structures. This invention can be applied to all metal materials where spatter adhesion would cause problems. In this case, it can also be applied when welding is done using a welding method other than spot welding. [Explanation of symbols]

[0030] 1. Plate-shaped metal material 2 Weld Bolts 3 Through holes 4 protrusions 5 screw shaft 6 Welding protrusions 7 head 8 recess 9 Back edge of (through hole) A Metal plate B Through hole C Weld Bolt D head E Welding protrusion F screw shaft

Claims

1. It is one of the two or more metal materials to be welded, The metal material has through holes that penetrate the front and back surfaces, and protrusions for preventing spatter from flying in around the through holes. The protrusions protrude from the surface of the metal material and have a shape and height that can prevent spatter generated when welding with other metal materials from flying into the through holes. A metal material characterized by:

2. It is one of the two or more metal materials to be welded, The metal material is a weld bolt, the back surface of the head, there is a weld protrusion on the outer periphery of the screw shaft, and there is a recess between the root side of the screw shaft and the weld protrusion, The recess is for preventing contact with the protrusions, and is wide and deep enough that the protrusions for preventing spatter from flying in, which are provided on the outer periphery of the through hole of the other metal material to be welded to the weld bolt, do not come into contact with the back surface of the head of the weld bolt. A metal material characterized by:

3. A welded metal material in which two metal materials are welded together, One of the metal materials has a through hole, and a protrusion on the outside of the through hole to prevent spatter from entering. The other metal material is a weld bolt, which has a welding protrusion on the backside of the head and a recess between the outside of the base of the screw shaft and the welding protrusion. The recess is wide and deep enough that the protrusion for preventing spatter from flying in does not come into contact with the screw shaft even when it is inserted into the through-hole of one metal material. The screw shaft of the weld bolt is inserted into the through hole of one metal material, and the protrusion for preventing spatter from flying into the other metal material is housed in the recess on the back surface of the head of the weld bolt so that it does not come into contact with the head, and in this state the head of the one metal material and the weld bolt are welded. A welded metal material characterized by:

4. This is a welding method for a metal material having a through hole and a protrusion on the outside thereof for preventing spatter from flying in, and a weld bolt having a recess for avoiding contact with the protrusion, The threaded shaft of the weld bolt is inserted into the through hole of the metal material, so that the welding protrusion on the back surface of the head of the weld bolt comes into contact with the metal material, and the protrusion on the outer periphery of the through hole is accommodated in the recess on the back surface of the head of the weld bolt so that it does not come into contact with the back surface of the head, In this state, current is passed through the metal material and the weld bolt to weld the metal material and the weld protrusion of the weld bolt. A welding method characterized by:

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