JP2021023944A - Spot welding method, welding device and vehicle - Google Patents

Abstract

To provide a spot welding method, a welding device and a vehicle which can further improve efficiency of a welding work.SOLUTION: A spot welding method, which is a method for joining a first member having a first flange part extending in a predetermined direction, a second member that has a second flange part extending in the predetermined direction, and forms a structure having a hollow part extending in the predetermined direction together with the first member by joining the second flange part to the first flange part to form a flange joint part, and a third member joined to the outside surface of the first member in the hollow part of the structure by spot welding, includes a first welding step of simultaneously performing spot welding of the first flange part and the second flange part and spot welding of the first member and the third member by indirect spot welding.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to spot welding methods, welding equipment and vehicles.

Conventionally, indirect spot welding has been performed when another member is arranged on one side of the member to be welded or when there is a space limitation (see, for example, Patent Document 1).

In Patent Document 1, in indirect spot welding, a holding member for holding a plate-shaped member to be welded is provided between the ground electrode and the plate-shaped member to ensure sufficient contact between the ground electrode and the plate-shaped member, and ground. A technique for suppressing welding and electrolytic corrosion around the contact portion between the electrode and the plate-shaped member is disclosed.

Japanese Unexamined Patent Publication No. 2016-59937

In the technique disclosed in Patent Document 1, as described in FIG. 1 of Patent Document 1, the ground electrode and the sandwiching member are integrated C-shaped members, while the welded electrode is the C-shaped member. Is configured as a separate member. Then, since the distance between the ground electrode and the welding electrode becomes long, the device becomes large and the welding work in a narrow place becomes difficult, and the invalid current at the time of welding increases, and the efficiency of the welding work is improved. There was a problem that it was difficult to make it.

Therefore, the inventors of the present application have found an indirect spot welding apparatus and a welding method capable of contributing to the miniaturization of the apparatus and improving the efficiency of welding work by integrating the welding electrode with the earth electrode, and applied for this. (Japanese Patent Application No. 2018-181295).

It is an object of the present disclosure to provide a spot welding method, a welding device and a vehicle capable of further improving the efficiency of welding work.

In order to solve the above problems, the spot welding method according to the first technique disclosed herein includes a first member having a first flange portion extending in a predetermined direction and a second flange portion extending in the predetermined direction. Then, the second flange portion is joined to the first flange portion to form a flange joint portion, so that the second member and the second member form a structure having a hollow portion extending in a predetermined direction together with the first member. , A method of joining a third member to be joined to the outer surface of the first member in the hollow portion of the structure by spot welding, wherein the first flange portion and the second flange portion are spot welded. It is characterized by including a first welding step in which the first member and the spot welding of the third member are simultaneously performed by indirect spot welding.

According to this configuration, spot welding of the first flange portion and the second flange portion and spot welding of the first member and the third member can be performed at the same time, so that the work process can be simplified and the work time can be shortened. It is possible to contribute to the improvement of work efficiency.

The second technique is characterized in that, in the first technique, a second welding step of joining the first flange portion and the second flange portion by direct spot welding is further provided.

When only the first flange portion and the second flange portion are joined, direct spot welding is performed, and when the first flange portion and the second flange portion are joined and the third member and the first member are joined at the same time, the direct spot welding is performed. Indirect spot welding may be performed. By combining these spot weldings, the joining of the first member and the second member can be strengthened, and the strength of the structure can be improved.

The third technique is characterized in that, in the second technique, the first welding step is performed after the second welding step is performed.

By performing direct spot welding collectively and then performing indirect spot welding collectively, it is possible to shorten the time required for switching between the two, which can contribute to the improvement of work efficiency. Further, by performing the direct spot welding collectively first, the joining of the first member and the second member is strengthened, and the strength of the structure is increased. Then, the positioning accuracy of the third member is improved.

The fourth technique is that in any one of the first to third techniques, the flange joint is welded at a plurality of flange welding points arranged in the predetermined direction, and the third member is the third member. The first member is welded at a plurality of welding points arranged in a predetermined direction, and the distance between adjacent flange welding points is narrower than the distance between adjacent welding points.

According to this configuration, the number of flange welding points can be larger than the number of welding points. As a result, the joint between the first member and the second member can be strengthened, and the strength of the structure can be improved.

The fifth technique is one of the first to fourth techniques, wherein the first member and the second member are side sill rain and side sill inner, respectively, and the third member is a cab side outer. It is characterized by being.

According to this configuration, it is possible to provide a vehicle side sill structure having excellent durability, strength and design.

The sixth technique further includes, in any one of the first to fifth techniques, a second welding step of joining the first flange portion and the second flange portion by direct spot welding, and the first flange portion. A plate-shaped fourth member having a notch portion is arranged between the portion and the second flange portion, and the first welding step is performed at the position where the notch portion is arranged. The second welding step is performed at a position where the notch is not arranged.

When the plate-shaped fourth member is arranged between the first flange portion and the second flange portion, three plates are spot-welded at the flange joint portion. In the direct spot welding of the second welding step, spot welding of three plates can be performed. On the other hand, in indirect spot welding in the first welding step, spot welding of three plates at the flange joint is difficult. Therefore, in the flange joint portion, a notch portion is provided in the fourth member located at the portion to be joined by indirect spot welding in the first welding step, and the plate 2 between the first flange portion and the second flange portion is substantially provided. Indirect spot welding is performed as a sheet. As a result, even when a plate-shaped fourth member is arranged between the first flange portion and the second flange portion, spot welding of the first flange portion and the second flange portion and the first member And spot welding of the third member can be performed at the same time.

The spot welding apparatus according to the seventh technique disclosed herein has a first member having a first flange portion extending in a predetermined direction and a second flange portion extending in the predetermined direction, and the second flange portion is the said. A second member that forms a structure having a hollow portion extending in a predetermined direction together with the first member by forming a flange joint portion by being joined to the first flange portion, and the hollow portion of the structure. A device for joining a third member to be joined to the outer surface of the first member by spot welding, a columnar first electrode that is pressure-contacted to the first flange portion, and the first. A columnar second electrode that is arranged coaxially with the electrode and sandwiches the first flange portion and the second flange portion at a flange welding point between the first electrode and the first of the third member. A columnar third electrode that is in pressure contact with a welding point with a member and a first circuit that electrically connects the second electrode and the third electrode are provided, and the first electrode is the first electrode. The two electrodes and the third electrode are insulated from each other, and the second electrode or the third electrode is grounded so that the first electrode and the second electrode sandwich the flange welding point and the first electrode. By energizing the first circuit with the three electrodes in pressure contact with the welding point, the first member and the second member are spot-welded at the flange welding point, and at the same time, the welding point. It is characterized by performing indirect spot welding in which the first member and the third member are spot welded.

According to this configuration, spot welding at the flange welding point and the welding point can be performed at the same time, so that the work process can be simplified and the work time can be shortened, which can contribute to the improvement of work efficiency.

The eighth technique is that in the seventh technique, the first electrode is grounded when the third electrode is grounded, while it is grounded when the second electrode is grounded. Instead, a second circuit that electrically connects the first electrode and the second electrode, and a switching device that switches between the electrical connection of the first circuit and the electrical connection of the second circuit. In addition to disconnecting the electrical connection of the first circuit, direct spot welding is performed at the flange welding point by energizing the second circuit, and the switching device electrically supplies the first circuit. By switching between the connection and the electrical connection of the second circuit, it is possible to switch between indirect spot welding in which the flange welding point and the welding point are welded at the same time and direct spot welding at the flange welding point. It is characterized by.

If only the flange welding points are joined, direct spot welding is performed using the second circuit, and if the flange welding points and welding points are joined at the same time, indirect spot welding is performed using the first circuit. Good. Since these spot welding can be performed by one device, it can contribute to further improvement of work efficiency.

The ninth technique is that in the seventh or eighth technique, the first electrode, the second electrode, and the third electrode are physically integrated, and the third electrode is the first electrode. It is characterized in that it is configured to be movable in the circumferential direction and / or the radial direction of the axis of.

According to this configuration, the position of the welding point with respect to the flange welding point can be adjusted by making the third electrode movable in the circumferential direction and / or the radial direction of the axis of the first electrode.

The vehicle according to the tenth technique disclosed herein has a side sill rain that extends in the front-rear direction and has first flange portions at both ends in the vertical direction, and a flange joint portion that extends in the front-rear direction and is joined to the first flange portion. A side sill inner that has a second flange portion that forms a hollow portion that extends inward in the front-rear direction while being joined to the side sill rain, and a cab that is joined to the outer surface of the hollow portion of the side sill rain. A vehicle provided with a side outer, and the first flange portion and the second flange portion are spot welded at a plurality of flange welding points arranged at regular intervals in the front-rear direction, and the cab side outer is provided. Is spot-welded to the side sill rain at a plurality of welding points arranged at regular intervals in the front-rear direction, and the distance between adjacent flange welding points is narrower than the distance between adjacent welding points. It is a feature.

According to this configuration, it is possible to obtain a vehicle having a side sill structure having excellent durability, strength and design.

As described above, according to the present disclosure, spot welding of the first flange portion and the second flange portion and spot welding of the first member and the third member can be performed at the same time, so that the work process can be simplified. The work time can be shortened, which can contribute to the improvement of work efficiency.

It is a figure which shows typically the spot welding apparatus which concerns on Embodiment 1. It is a figure which shows the circuit structure of the spot welding apparatus of FIG. It is a top view of the 1st electrode, the 3rd electrode and the connection part of the spot welding apparatus of FIG. It is a perspective view which shows an example of the vehicle which concerns on this embodiment. It is a bottom view of the side sill structure part of FIG. FIG. 5 is a cross-sectional view taken along the line AA of FIG. It is sectional drawing in BB line of FIG. FIG. 5 is a cross-sectional view taken along the line CC of FIG. It is a right side view of the side sill structure part of FIG. 9 is a perspective view of the right side view of FIG. 9 seen from slightly below. 9 is a diagram showing a state in which the side step is removed in FIG. It is a flowchart for demonstrating the process of the spot welding method which concerns on Embodiment 1. FIG. 2 is a view corresponding to FIG. 2 of the spot welding apparatus according to the second embodiment. FIG. 2 is a view corresponding to FIG. 2 of the spot welding apparatus according to the second embodiment. It is a flowchart for demonstrating the process of the spot welding method which concerns on Embodiment 2. It is a top view for demonstrating the spot welding method which concerns on Embodiment 3. 16 is a cross-sectional view taken along the line EE of FIG. It is sectional drawing in the DD line of FIG. It is a figure which shows typically the state which the 3rd electrode was brought into pressure contact with the work which concerns on another Embodiment.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The following description of preferred embodiments is merely exemplary and is not intended to limit the disclosure, its application or its use.

(Embodiment 1)
<Spot welding equipment>
As shown in FIGS. 1 to 3, the spot welding apparatus 1 according to the first embodiment includes a first electrode 11, a second electrode 12, and a third electrode 13. The work 100 is arranged between the first electrode 11 and the third electrode 13 and the second electrode 12.

≪Work and vehicle≫
As shown in FIGS. 4 to 11, the work 100 is a part of the side sill structure of the vehicle 900 according to the present embodiment.

FIG. 4 is a perspective view showing a rear lower structure of the vehicle 900 according to the present embodiment. Note that in FIG. 4, the detailed configuration of tires and the like is not shown. FIG. 5 is a bottom view of the side sill structure portion of FIG. 6 to 8 are cross-sectional views taken along the line AA, BB and CC of FIG. 5, respectively. FIG. 9 is a right side view of the side sill structure portion of FIG. FIG. 10 is a perspective view of the right side view of FIG. 9 as viewed from slightly below. FIG. 11 is a diagram showing a state in which the side step is removed in FIG.

In the present specification, when the vehicle 900 and its parts are described, as shown in FIG. 4, the vehicle 900 is referred to in the front-rear direction, the left-right direction, and the up-down direction. The front-rear direction, left-right direction, and up-down direction of the vehicle 900 are perpendicular to each other.

As shown in FIG. 6, the work 100 includes a side sill rain 110 (first member), a side sill inner 120 (second member), and a cab side outer 130 (third member). A side step 160 (exterior member) is provided on the outer side of the work 100.

-Side sill rain-
The side sill rain 110 is a member extending in the front-rear direction (predetermined direction). The side sill rain 110 has a first main body portion 111 and a first flange portion 112.

The first main body portion 111 has a U-shaped cross section convex to the right side, and is a half-pipe type portion extending in the front-rear direction. The first flange portion 112 is a plate portion connected to both ends in the vertical direction of the first main body portion 111 and extends in the front-rear direction.

-Side sill innerr-
The side sill inner 120 is a member extending in the front-rear direction like the side sill rain 110. The side sill inner 120 has a second main body portion 121 and a second flange portion 122. The second main body portion 121 has a U-shaped cross section that is convex on the left side, and is a half-pipe type portion that extends in the front-rear direction. The second flange portion 122 is a plate portion connected to both ends in the vertical direction of the second main body portion 121 and extends in the front-rear direction.

-Structure-
The side sill rain 110 and the side sill inner 120 form a pipe-shaped structure 140 extending in the front-rear direction by joining the first flange portion 112 and the second flange portion 122 to each other. The structure 140 is a component that forms the skeleton of the lower side of the vehicle 900. Specifically, for example, as shown in FIG. 11, the first flange portion 112 and the second flange portion 122 are the first flange welding point 145 and the second flange welding point as a plurality of flange welding points arranged in the front-rear direction. Spot welding is performed at 147 (hereinafter collectively referred to as "flange welding points 145, 147"). Then, the first flange portion 112 and the second flange portion 122 form the flange joint portion 142 of the structure 140. As shown in FIGS. 6 to 8, the main body 141 of the structure 140 is formed by the first main body 111 and the second main body 121 in a state where the first flange portion 112 and the second flange portion 122 are joined. To.

The main body portion 141 includes a hollow portion 143 extending in the front-rear direction formed by the inner side surfaces of the first main body portion 111 and the second main body portion 121. That is, the structure 140 becomes a member having a closed cross-sectional structure including the hollow portion 143 by forming the flange joint portion 142.

-Cab side outer
The cab side outer 130 is an exterior member on the side surface of the vehicle 900. The cab side outer 130 is joined to the outer surface of the first main body 111 of the side sill rain 110.

The cab side outer 130 has a plate-shaped third flange portion 131 extending in the front-rear direction. The third flange portion 131 is spot-welded to the outer surface of the first main body portion 111 of the side sill rain 110 at a plurality of welding points 149 arranged in the front-rear direction.

-Side step-
A side step 160 is arranged on the side sill rain 110 side of the work 100 so as to protect the cab side outer 130 and the flange joint 142. The side step 160 covers the side sill structure of the vehicle 900 and contributes to improving the design of the vehicle 900, suppressing damage to the side sill structure, and the like.

As shown in FIGS. 4, 5 and 7, the side step 160 includes a mounting portion 162. The mounting portion 162 is provided with a bolt hole 163. The side step 160 is fixed to the side sill rain 110 by a bolt (not shown) inserted into the bolt hole 163.

As shown in FIGS. 4 and 5, the side step 160 has a recess 161 for attaching a jack (not shown) when jacking up the vehicle 900. As shown in FIGS. 4, 6 to 8, and the like, the portion of the side step 160 other than the recess 161 covers the flange joint portion 142. On the other hand, the flange joint portion 142 is exposed at the portion of the side step 160 where the recess 161 is arranged. That is, the flange joint portion 142 of the structure 140 includes a covering portion 142A (part) covered with the side step 160 and an exposed portion 142B (other part) not covered with the side step 160.

≪Device configuration≫
The spot welding device 1 according to the present embodiment is for simultaneously performing spot welding of the first flange portion 112 and the second flange portion 122 and spot welding of the side sill rain 110 and the cab side outer 130 by indirect spot welding. It is a device. Specifically, the first flange portion 112 and the second flange portion 122 are spot welded at the second flange welding point 147. Further, the side sill rain 110 and the cab side outer 130 are spot welded at the welding point 149.

-Electrical circuit and power supply-
As shown in FIG. 2, the spot welding device 1 includes a first circuit 16 and a power supply device 15 electrically connected to the second electrode 12 and the third electrode 13. Although not shown, the power supply device 15 includes a control unit and the like that control the amount of current flowing between the electrodes.

-First electrode and second electrode-
The first electrode 11 and the second electrode 12 are brought into pressure contact with the flange joint 142. A flange joint 142 is sandwiched between the first electrode 11 and the second electrode 12.

As shown in FIGS. 1 and 2, the first electrode 11 is a columnar counter electrode arranged on the first flange portion 112 side of the flange joint portion 142 and insulated from the second electrode 12 and the third electrode 13. is there. The second electrode 12 is a columnar welding electrode arranged on the second flange portion 122 side of the flange joint portion 142. The shape of the first electrode 11 and the second electrode 12 is not limited to a columnar shape, and may be a columnar shape such as an elliptical columnar shape or a polygonal columnar shape.

As shown in FIG. 1, the second electrode 12 is physically integrated with the first electrode 11 to form a C-shaped gun. Specifically, as shown in FIG. 1, the second electrode 12 is connected to the base 2a. The base 2a is connected to the support portion 2c. A columnar first electrode gun 11b is connected to the tip of the support portion 2c. The first electrode 11 is connected to the tip of the gun 11b for the first electrode. That is, the first electrode 11 and the second electrode 12 form a C-type gun together with the base 2a, the support portion 2c, and the gun 11b for the first electrode.

The central axis of the gun 11b for the first electrode and the first electrode 11 is the axis L1. The second electrode 12 is arranged coaxially with the first electrode 11 so as to face each other. That is, the first electrode 11 and the second electrode 12 have the same axis L1.

The first electrode driving means 2b is provided on the side of the gun 11b for the first electrode opposite to the side to which the first electrode 11 is connected.

The first electrode gun 11b moves in the axial center L1 direction as shown by the arrow G1 in FIG. 1 in accordance with the operation of the first electrode driving means 2b. Then, as the first electrode gun 11b moves, the first electrode 11 also moves in the axial center L1 direction. That is, the first electrode 11 moves so as to approach the second electrode 12 as the first electrode driving means 2b operates. Then, the first electrode 11 is pressure-contacted with the position of the second flange welding point 147 on the outer surface of the first flange portion 112 of the flange joint portion 142. On the other hand, the second electrode 12 is pressure-contacted with the position of the second flange welding point 147 on the outer surface of the second flange portion 122 of the flange joint portion 142. In this way, the second electrode 12 sandwiches the second flange welding point 147 at the flange joint 142 with the first electrode 11.

The first electrode driving means 2b is not particularly limited, but for example, a driving mechanism using an air cylinder, a ball screw mechanism driven by a motor, a robot arm, or the like can be adopted.

The first electrode 11 comes into pressure contact with the side silrain 110 on the tip surface 11a of the first electrode. The shape of the tip surface 11a of the first electrode is circular with the axis L1 as the center (see FIG. 3), but the shape is not limited to the shape as long as a sufficient amount of electricity can be secured. It may have an elliptical shape or a rectangular shape centered on the axis L1. The maximum diameter of the tip surface 11a of the first electrode can be, for example, 5 mm or more and 16 mm or less from the viewpoint of ensuring a sufficient amount of energization.

Further, the second electrode 12 comes into contact with the side silin inner 120 on the tip surface 12a of the second electrode. The shape of the tip surface 12a of the second electrode is also not particularly limited, but is the same as the center of the tip surface 11a of the first electrode from the viewpoint of reliably sandwiching the flange joint 142 with the first electrode 11. It can be a circular shape, an elliptical shape, a rectangular shape, or the like. The maximum diameter of the tip surface 12a of the second electrode can be, for example, 3 mm or more and 8 mm or less from the viewpoint of securely sandwiching the flange joint 142 with the first electrode 11. It is desirable that the maximum diameter of the second electrode tip surface 12a is smaller than the maximum diameter of the first electrode tip surface 11a. As a result, slippage when the flange joint portion 142 is sandwiched between the first electrode tip surface 11a and the second electrode tip surface 12a can be suppressed.

The pressing force of the first electrode 11 is, for example, 1.5 kN or more and 6 kN or less from the viewpoint of ensuring sufficient contact with the side sill rain 110 and securely sandwiching the flange joint 142 with the second electrode 12. be able to.

-Third electrode-
The third electrode 13 is a columnar ground electrode grounded as shown in FIG. The third electrode 13 is pressure-contacted with the welding point 149 on the outer surface of the cab side outer 130. The shape of the third electrode 13 is not limited to a columnar shape, and may be a columnar shape such as an elliptical columnar shape or a polygonal columnar shape.

The third electrode 13 is connected to the first electrode 11 and is further physically integrated with the C-shaped gun including the first electrode 11 and the second electrode 12.

Specifically, the first electrode gun 11b is provided with a columnar third electrode gun 13b via a connecting portion 4. The columnar third electrode 13 is provided at the tip of the third electrode gun 13b. The central axis of the third electrode 13 and the gun 13b for the third electrode is the axis L2. The axis L2 is parallel to the axis L1 of the first electrode 11 and the gun 11b for the first electrode, and is located at a position deviated from the axis L1.

The third electrode driving means 3 is provided on the third electrode gun 13b. By the third electrode driving means 3, the gun 13b for the third electrode can be moved in the axial center L2 direction as shown by the arrow G2 in FIG. The movement of the third electrode gun 13b is independent of the movement of the first electrode gun 11b. That is, the third electrode 13 is configured to be movable in the axial center L2 direction independently of the movement of the first electrode 11 in the axial center L1 direction. As the third electrode driving means 3, for example, a driving mechanism using an air cylinder, a ball screw mechanism driven by a motor, or the like can be adopted.

By physically integrating the third electrode gun 13b with the first electrode gun 11b, the distance between the first electrode 11 and the third electrode 13 can be shortened. Specifically, the distance between the center of the tip surface 11a of the first electrode and the center of the tip surface 13a of the third electrode, that is, the shortest distance between the axis L1 and the axis L2, shortens the electric path and reduces the amount of electricity and the welding time. From the viewpoint of enabling efficient welding, for example, the thickness can be 30 mm or more and 150 mm or less. With this configuration, the electric circuit can be shortened and the energizing time required for welding can be shortened. As a result, deformation of the work 100 due to pressure contact between the third electrode 13, the first electrode 11, and the second electrode 12 can be suppressed. In addition, it is possible to suppress excessive welding of the welded portion due to energization. In addition, it can bring about cost reduction and simplification of the welding process.

As shown in FIG. 1, the third electrode 13 comes into pressure contact with the cab side outer 130 on the tip surface 13a of the third electrode. The shape of the tip surface 13a of the third electrode is a circle centered on the axis L2 (see FIG. 3). The shape of the tip surface 13a of the third electrode is not limited to the circular shape as long as a sufficient amount of energization can be secured, and may be, for example, an elliptical shape or a rectangular shape centered on the axis L2. The maximum diameter of the tip surface 13a of the third electrode can be, for example, 3 mm or more and 16 mm or less from the viewpoint of narrowing the electric circuit while ensuring a sufficient amount of energization.

Further, the pressing force of the third electrode 13 can be, for example, 0.4 kN or more and 2.0 kN or less from the viewpoint of suppressing damage to the cab side outer 130 while ensuring sufficient contact with the cab side outer 130.

Since the third electrode 13 is physically integrated with the first electrode 11, the relative position of the third electrode 13 in the axial L2 direction with respect to the first electrode 11 can be maintained with high accuracy. Then, the pressing force of the third electrode 13 can be controlled with high accuracy. Then, while suppressing the deformation of the side sill rain 110 and the side sill inner 120, the contact resistance of the third electrode 13 can be stably controlled, and excellent welding quality can be brought about with good reproducibility.

In the spot welding apparatus 1 according to the present embodiment, as shown by the arrow of the reference numeral G3 in FIG. 3, the third electrode 13 is rotatable in the circumferential direction of the axis L1 of the first electrode 11. Further, the third electrode 13 can also move in the radial direction of the axial center L1 of the first electrode 11, as shown by the arrow of reference numeral G4 in FIG.

<Spot welding method>
As shown in FIG. 12, the indirect spot welding method according to the present embodiment includes a sandwiching step S1, a pressure contact step S2, and a first energizing step S3 (first welding step).

-Pinching process-
First, in the sandwiching step S1, the flange joint portion 142 is sandwiched by the first electrode 11 and the second electrode 12.

Specifically, for example, with the first electrode 11 and the second electrode 12 sufficiently separated from each other, the second flange in the flange joint 142 of the structure 140 is placed on the second electrode tip surface 12a of the second electrode 12. A welding point 147 is arranged. Then, the first electrode 11 is moved in the axial direction L1 by the operation of the first electrode driving means 2b, and the tip surface 11a of the first electrode is brought into pressure contact with the second flange welding point 147 of the flange joint 142. Then, the second flange welding point 147 of the flange joint portion 142 is sandwiched by the first electrode 11 and the second electrode 12.

-Pressure contact process-
Next, in the pressure contact step S2, the third flange portion 131 of the cab side outer 130 is brought into contact with the outer surface of the first main body portion 111 of the side sill rain 110 of the structure 140. Then, the third electrode driving means 3 is driven to move the third electrode 13 in the axial L2 direction, and the third electrode 13 is brought into pressure contact with the welding point 149 at the third flange portion 131 of the cab side outer 130. ..

-First energization process-
Then, in the first energization step S3, a current is passed between the second electrode 12 and the third electrode 13. From the second electrode tip surface 12a of the second electrode 12, through the second flange portion 122, the second flange welding point 147, the side silrain 110, and the welding point 149, to the third electrode tip surface 13a of the third electrode 13. An electric circuit C1 to reach is formed. Then, spot welding at the second flange welding point 147 and the welding point 149 is performed at the same time. The control unit of the power supply device 15 adjusts the appropriate amount of current and welding time while maintaining the appropriate pressing force of the first electrode 11 and the third electrode 13, and the first flange portion 112 and the second flange portion 122. And the welding of the cab side outer 130 and the side sill rain 110 is completed.

-Characteristics and effects-
The spot welding apparatus 1 and the method according to the present embodiment are characterized by the following. That is, the first circuit 16 is energized with the second flange welding point 147 sandwiched between the first electrode 11 and the second electrode 12 and the third electrode 13 being in pressure contact with the welding point 149. Then, indirect spot welding is performed by energizing between the second electrode 12 and the third electrode 13. As a result, at the second flange welding point 147, the first flange portion 112 of the side sill rain 110 and the second flange portion 122 of the side sill inner 120 are spot welded. At the same time, the side sill rain 110 and the cab side outer 130 are spot welded at the welding point 149.

According to this configuration, spot welding of the first flange portion 112 and the second flange portion 122 and spot welding of the side sill rain 110 and the cab side outer 130 can be performed at the same time, so that the work process can be simplified and the work time can be reduced. It can be shortened. As a result, it is possible to contribute to the improvement of work efficiency of spot welding work. Then, it is possible to obtain a vehicle having a side sill structure having excellent durability, strength and design.

As shown in FIG. 11, it is desirable that the second flange welding point 147 is arranged at a position different from that of the first flange welding point 145, for example, between adjacent first flange welding points 145.

Since the first flange welding point 145 has already been spot-welded, if the second flange welding point 147 is set at the same location as the first flange welding point 145, the second electrode 12 and the second flange portion 122 will be connected. It can be difficult to secure a sufficient contact area between them. Then, it becomes difficult to secure a sufficient amount of current in the first energization step S3. According to this configuration, by arranging the second flange welding point 147 at a position different from that of the first flange welding point 145, a sufficient contact area between the second electrode 12 and the second flange portion 122 can be secured. As a result, sufficient joint strength can be ensured at the second flange welding point 147 and the welding point 149.

Further, as shown in FIG. 11, it is preferable that the flange welding points 145 and 147 are arranged side by side in substantially one line in the front-rear direction with a certain distance from each other. It is more preferable that the distance between the adjacent flange welding points 145 and 147 is constant. If the distance between the adjacent flange welding points 145 and 147 is constant, the joint strength of the side sill rain 110 and the side sill inner 120 becomes uniform throughout the front-rear direction.

Further, the welding points 149 are also arranged in a substantially line in the front-rear direction with a certain distance from each other. It is desirable that the distance between adjacent welding points 149 is constant. If the distance between the adjacent welding points 149 is constant, the joint strength of the cab side outer 130 and the side sill rain 110 becomes uniform throughout the front-rear direction.

It is desirable that the distance between the adjacent flange welding points 145 and 147 is narrower than the distance between the adjacent welding points 149. However, indirect spot welding is easier to divide into adjacent spot welding points than normal direct spot welding, so from the viewpoint of guaranteeing welding quality, the spacing between adjacent flange welding points 145 and 147 should be sufficient. And. As described above, the structure 140 including the side sill rain 110 and the side sill inner 120 is a skeleton component of the vehicle 900. Therefore, it is required that the joint strength of the side sill rain 110 and the side sill inner 120 is higher than the joint strength between the cab side outer 130 and the side sill rain 110. According to this configuration, the number of flange welding points 145 and 147 can be larger than the number of welding points 149. As a result, the joint between the side sill rain 110 and the side sill inner 120 can be strengthened, and the strength of the structure 140 can be improved.

Further, in the spot welding apparatus 1 according to the present embodiment, as shown in FIGS. 1 and 3, the third electrode 13 can move in the axial center L2 direction, the circumferential direction of the axial center L1, and the radial direction of the axial center L1. It is configured in. With this configuration, the position of the welding point 149 with respect to the second flange welding point 147 can be adjusted.

Specifically, FIG. 11 shows the corresponding second flange welding points 147 and welding points 149 with broken lines. That is, for example, when the first electrode 11 and the second electrode 12 sandwich the second flange welding point 147A, the third electrode 13 is brought into contact with the welding point 149A to perform indirect spot welding.

By the way, since the length of the electric circuit and the amount of current are different between the first flange welding point 145 and the second flange welding point 147, the sizes may not be the same. Then, from the viewpoint of designability, it is conceivable that only the first flange welding point 145 is provided in the portion that can be visually recognized from the outside.

Specifically, the side sill rain 110 side of the exposed portion 142B of the flange joint portion 142 is not covered by the side step 160, so that it can be visually recognized from the outside. On the other hand, since the covering portion 142A of the flange joining portion 142 is covered by the side step 160, it is difficult to be visually recognized from the outside. Therefore, the design of the side sill structure of the vehicle 900 can be improved by forming the second flange welding point 147 on the covering portion 142A but not forming the second flange welding point 147 on the exposed portion 142B.

More specifically, as shown in FIG. 11, consider, for example, a case where the second flange welding point 147A is sandwiched between the first electrode 11 and the second electrode 12. In FIG. 11, it is assumed that welding is performed at the welding point 149 in order from the front side. With the second flange welding point 147A sandwiched between the first electrode 11 and the second electrode 12, the third electrode 13 is brought into contact with the welding point 149A, and welding is performed at the second flange welding point 147A and the welding point 149A. After that, the sandwiching of the second flange welding point 147A by the first electrode 11 and the second electrode 12 is released. Then, as shown in FIG. 3, the third electrode 13 is rotated in the circumferential direction of the axis L2 of the first electrode 11. Then, the second flange welding point 147A is sandwiched again by the first electrode 11 and the second electrode 12, and the third electrode 13 is brought into contact with the welding point 149B to perform welding at the welding point 149B.

Further, the sandwiching of the second flange welding point 147A by the first electrode 11 and the second electrode 12 is released, the third electrode 13 is further rotated in the circumferential direction of the axial center L2 in the first electrode 11, and the radial direction and the first electrode 13 are further rotated. 1 Move in the direction away from the electrode 11. Then, the second flange welding point 147A is sandwiched again by the first electrode 11 and the second electrode 12, and the third electrode 13 is brought into contact with the welding point 149C to perform welding at the welding point 149C. In this way, by adjusting the position of the axial center L1 of the first electrode 11 of the third electrode 13 in the circumferential direction and / or the radial direction, the position of the welding point with respect to the flange welding points 145 and 147 can be adjusted. ..

(Embodiment 2)
Hereinafter, other embodiments according to the present disclosure will be described in detail. In the description of these embodiments, the same parts as those of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

<Spot welding equipment>
-Electrical circuit and power supply-
13 and 14 are views corresponding to FIG. 2 of the spot welding apparatus 1 according to the present embodiment.

As shown in FIGS. 13 and 14, the spot welding apparatus 1 according to the present embodiment includes a second circuit 17 that electrically connects the first electrode 11 and the second electrode 12 in addition to the first circuit 16 described above. Have. The first circuit 16 and the second circuit 17 are connected to a common power supply device 15. The spot welding device 1 includes a switch 18 (switching device) that switches between the electrical connection of the first circuit 16 and the electrical connection of the second circuit 17. When the switch 18 is in the state of reference numeral 18A shown in FIG. 13, the electrical connection of the first circuit 16 is cut off and the electrical connection of the second circuit 17 is turned on. On the other hand, when the switch 18 is in the state of reference numeral 18B shown in FIG. 14, the electrical connection of the second circuit 17 is disconnected and the electrical connection of the first circuit 16 is turned on.

As shown in FIGS. 13 and 14, the first electrode 11 and the third electrode 13 are ground electrodes grounded in the second circuit 17 and the first circuit 16, respectively. The second electrode 12 is a welded electrode in any circuit. Although not shown, the second electrode 12 may be used as the ground electrode. In this case, in the first circuit 16 and the second circuit 17, the third electrode 13 and the first electrode 11 serve as welding electrodes, respectively.

<Spot welding method>
The spot welding method according to the present embodiment includes the sandwiching step S11 and the second energization step S12 (second welding step) as the direct spot welding step SII shown in FIG. 15, and the above-described embodiment as the indirect spot welding step SI. Each step S1 to S3 of 1 (see FIG. 12) is included.

Specifically, in the direct spot welding step SII shown in FIG. 15, in the sandwiching step S11, the first flange welding point 145 of the first flange portion 112 and the second flange portion 122 is formed by the first electrode 11 and the second electrode 12. Hold it. The pinching step S11 is the same as the pinching step S1 of FIG. 12 except that the pinching position is set to the first flange welding point 145.

Next, in the second energization step S12, the switch 18 is set to the state shown in FIG. 13, the electrical connection of the first circuit 16 is cut off, and the electrical connection of the second circuit 17 is turned on. Then, by energizing the second circuit 17, direct spot welding is performed at the first flange welding point 145. In the second energization step S12, spot welding at the welding point 149 is not performed. Although it is described in FIG. 13 that the third electrode 13 is in contact with the cab side outer 130, it may not be in contact with the third electrode 13.

As described above, according to the spot welding apparatus 1 and the method according to the present embodiment, spot welding at the first flange welding point 145 can be performed by the direct spot welding step SII.

Indirect spot welding can also be performed by setting the switch 18 to the state shown in FIG. 14 and simultaneously welding the second flange welding point 147 and the welding point 149 by the method described in the first embodiment (see FIG. 12).

That is, according to the spot welding apparatus 1 and the method according to the present embodiment, by switching the switch 18, direct spot welding at the first flange welding point 145 and indirect spot at the second flange welding point 147 and welding point 149 You can switch between welding. As a result, two types of spot welding can be performed with one device, which can contribute to the improvement of work efficiency.

It is desirable to perform the indirect spot welding step SI after performing the direct spot welding step SII. In particular, it is desirable to perform the direct spot welding step SII at all the first flange welding points 145 and then perform the indirect spot welding step SI at all the second flange welding points 147 and 149.

By performing direct spot welding collectively and then performing indirect spot welding collectively, it is possible to shorten the time required for switching between the two, and it is possible to contribute to further improvement in work efficiency. Further, by performing the direct spot welding together first, the joint between the side sill rain 110 and the side sill inner 120 is strengthened, and the strength of the structure 140 is increased. As a result, the positioning accuracy of the cab side outer 130 is improved.

(Embodiment 3)
As shown in FIGS. 16 to 18, a plate-shaped spacer 170 (fourth member) may be arranged between the side sill rain 110 and the side sill inner 120 from the viewpoint of improving the rigidity of the structure 140. Then, as shown in FIG. 17, the flange joint portion 142 has a structure in which three plates are laminated.

If the first flange welding point 145 is welded in advance by direct spot welding in the first embodiment, or if the direct spot welding shown in FIG. 13 of the second embodiment is performed, welding can be performed even in a three-sheet laminated structure. .. However, in the indirect spot welding shown in FIG. 2 of the first embodiment and FIG. 14 of the second embodiment, since the second flange welding point 147 has a three-sheet laminated structure, the second flange welding point 147 and the welding point 149 are welded. It is difficult to do at the same time.

Therefore, as shown in FIGS. 16 to 18, the spot welding method according to the present embodiment is characterized in that the spacer 170 is provided with a notch portion 171 at a position corresponding to the second flange welding point 147. That is, the spacer 170 includes the notch portion 171 and a flat portion 172 provided at a position corresponding to the first flange welding point 145.

In the spot welding method according to the first embodiment, as shown in FIG. 17, direct spot welding is performed in advance at the position of the first flange welding point 145 where the flat portion 172 is arranged. Then, the position of the second flange welding point 147 in which the notch portion 171 is arranged is sandwiched between the first electrode 11 and the second electrode 12, and the indirect spot welding of FIG. 2 is performed.

The same applies to the spot welding method according to the second embodiment. Specifically, as shown in FIG. 17, the position of the first flange welding point 145 on which the flat portion 172 is arranged is sandwiched between the first electrode 11 and the second electrode 12, and the second energization step S12 is performed. Then, the position of the second flange welding point 147 in which the notch portion 171 is arranged is sandwiched between the first electrode 11 and the second electrode 12, and the first energization step S3 is performed. Although not intended to be limited, it is desirable to perform the indirect spot welding step SI after performing the direct spot welding step SII at all the first flange welding points 145 even when the spacer 170 is arranged. .. By performing the direct spot welding step SII first, the spacer 170 is fixed between the side sill rain 110 and the side sill inner 120. As a result, the accuracy of the welding work in the indirect spot welding process SI is improved.

(Other embodiments)
In the above embodiment, the work 100 has been described as an example of parts used in the side sill structure of the vehicle 900. The spot welding apparatus 1 and the method according to the present embodiment are not limited to the relevant parts, and can also be used for spot welding of other parts.

Specifically, for example, one of the first member and the second member may be a half-pipe type member and the other one may be a plate-shaped member as in the above embodiment.

Further, the shape of the third member is not particularly limited as long as spot welding is possible at a plurality of welding points arranged in a predetermined direction on the outer surface of the first main body. The third member is, for example, a plate-shaped member, a member having a plate-shaped flange portion, or the like.

Specific examples of the first member, the second member, the third member, and the exterior member include the following. That is, specifically, the first member and the second member are vehicle parts that can be joined to each other, such as a front panel, a floor panel, a rear panel, a side sill, a tunnel rain, a cross member, a frame, and an outer panel. Further, the third member and the exterior member are parts such as an outer that are further joined to the vehicle parts.

The first member, the second member, and the third member may be metal members that can be energized and generally spot welded. Specifically, for example, iron, steel, aluminum, alloys thereof and the like, and surface-plated metal members. The material of the exterior member is not particularly limited, and is appropriately determined according to the use of the exterior member.

In the above embodiment, the flange joint portion 142 may be formed by spot welding in combination with various other joining methods such as adhesives and rivets.

Further, in the configuration of the first embodiment, the second electrode 12 may be a ground electrode and the third electrode 13 may be a welding electrode. In the configuration of the second embodiment, the second electrode 12 may be a ground electrode, and the first electrode 11 or the third electrode 13 may be a welded electrode. The same applies to the configuration of the third embodiment.

As shown in FIG. 19, a convex portion 133 is provided on the side of the third flange portion 131 of the cab side outer 130 at the welding point 149 facing the side sill rain 110 from the viewpoint of promoting welding in the first energization step S3. You may. The convex portion 133 is a convex protrusion from the cab side outer 130 side toward the side sill rain 110 side at the welding point 149. Due to the presence of the convex portion 133, the electric path C1 is restricted within the convex portion 133 when the cab side outer 130 is brought into contact with the side sill rain 110 and energized. As a result, nugget formation, which is the starting point of welding, is promoted, and efficient and rapid welding becomes possible.

The size of the convex portion 133 is not particularly limited, but from the viewpoint of promoting nugget formation and shortening the welding time, for example, the maximum diameter of the convex portion 133 can be 1 mm or more and 5 mm or less. The method for forming the convex portion 133 is not particularly limited, but the convex portion 133 can be formed by press molding, punching, or the like. Further, in FIG. 13, the convex portion 133 is formed on the cab side outer 130, but may be formed on the side sill rain 110.

Further, instead of forming the convex portion 133, another member such as a metal piece may be arranged. Further, as another method, the diameter of the third electrode tip surface 13a of the third electrode 13 may be minimized to increase the energization density of the cab side outer 130 and the side sill rain 110. Separate members such as convex portions and metal pieces may be provided between the members at the flange welding points 145 and 147.

Further, in the above-described embodiment, a configuration using a direct current is described as an example, but an alternating current can also be used.

The present disclosure is extremely useful because it can provide spot welding methods, welding devices and vehicles that can further improve the efficiency of welding operations.

1 Spot welding device 2a Base 2b 1st electrode driving means 2c Supporting part 3 3rd electrode driving means 4 Connecting part 11 1st electrode 11a 1st electrode tip surface 11b 1st electrode gun 12 2nd electrode 12a 2nd electrode tip Surface 13 Third electrode 13a Third electrode tip surface 13b Gun for third electrode 15 Power supply device 16 First circuit 17 Second circuit 18 Switch (switching device)
100 Work 110 Side Sill Rain (1st member)
111 1st main body 112 1st flange 120 Side sill inner (2nd member)
121 2nd main body 122 2nd flange 130 Cab side outer (3rd member)
131 3rd flange part 133 Convex part 140 Structure 141 Main body part 142 Flange joint part 142A Covering part 142B Exposed part 143 Hollow part 145 1st flange welding point (flange welding point)
147 Second flange welding point (flange welding point)
149 Welding point 160 Side step (exterior member)
C1 Electric circuit L1 Axis L2 (for guns for 1st electrode and 1st electrode) Axis SI Indirect spot welding process S1 Holding process S2 Pressurized contact process S3 1st energization Process SII Direct spot welding process S11 Holding process S12 Second energizing process

Claims (10)

A first member having a first flange portion extending in a predetermined direction,
A hollow portion extending in a predetermined direction together with the first member is formed by having a second flange portion extending in a predetermined direction and joining the second flange portion with the first flange portion to form a flange joint portion. The second member forming the provided structure and
A third member joined to the outer surface of the first member in the hollow portion of the structure,
Is a method of joining by spot welding.
It is characterized by including a first welding step in which spot welding of the first flange portion and the second flange portion and spot welding of the first member and the third member are simultaneously performed by indirect spot welding. Spot welding method. In claim 1,
A spot welding method further comprising a second welding step of joining the first flange portion and the second flange portion by direct spot welding. In claim 2,
A spot welding method characterized in that the first welding step is performed after the second welding step is performed. In any one of claims 1 to 3,
The flange joint is welded at a plurality of flange welding points arranged in the predetermined direction.
The third member is welded to the first member at a plurality of welding points arranged in the predetermined direction.
A spot welding method characterized in that the distance between adjacent flange welding points is narrower than the distance between adjacent flange welding points. In any one of claims 1 to 4,
The first member and the second member are side sill rain and side sill inner, respectively, of the vehicle.
A spot welding method characterized in that the third member is a cab side outer. In any one of claims 1 to 5,
A second welding step of joining the first flange portion and the second flange portion by direct spot welding is further provided.
A plate-shaped fourth member having a notch is arranged between the first flange portion and the second flange portion.
At the position where the notch is arranged, the first welding step is performed.
A spot welding method characterized in that the second welding step is performed at a position where the notch portion is not arranged. A first member having a first flange portion extending in a predetermined direction,
A hollow portion extending in a predetermined direction together with the first member is formed by having a second flange portion extending in a predetermined direction and joining the second flange portion with the first flange portion to form a flange joint portion. The second member forming the provided structure and
A third member joined to the outer surface of the first member in the hollow portion of the structure,
Is a device for joining by spot welding.
A columnar first electrode that is in pressure contact with the first flange portion and
A columnar second electrode that is coaxially opposed to the first electrode and sandwiches the first flange portion and the second flange portion at a flange welding point with the first electrode.
A columnar third electrode that is in pressure contact with the welding point of the third member with the first member,
A first circuit that electrically connects the second electrode and the third electrode,
With
The first electrode is insulated from the second electrode and the third electrode.
The second electrode or the third electrode is grounded.
The flange welding point is sandwiched between the first electrode and the second electrode, and the first circuit is energized with the third electrode in pressure contact with the welding point. The spot welding apparatus is characterized in that, at the same time as spot welding the first member and the second member, indirect spot welding is performed by spot welding the first member and the third member at the welding point. In claim 7,
The first electrode is grounded when the third electrode is grounded, while it is not grounded when the second electrode is grounded.
A second circuit that electrically connects the first electrode and the second electrode,
A switching device that switches between the electrical connection of the first circuit and the electrical connection of the second circuit.
With
Direct spot welding at the flange welding point is performed by disconnecting the electrical connection of the first circuit and energizing the second circuit.
Indirect spot welding, in which the flange welding point and the welding point are simultaneously welded by switching between the electrical connection of the first circuit and the electrical connection of the second circuit by the switching device, and the flange. A spot welding device characterized in that it can be switched between direct spot welding at a welding point. In claim 7 or 8,
The first electrode, the second electrode, and the third electrode are physically integrated.
The spot welding apparatus, wherein the third electrode is configured to be movable in the circumferential direction and / or the radial direction of the axis of the first electrode. Side sill rain that extends in the front-rear direction and has first flanges at both ends in the vertical direction,
A side sill inner that extends in the front-rear direction and has a second flange portion that is joined to the first flange portion to form a flange joint portion, and forms a hollow portion that extends inward in the front-rear direction while being joined to the side sill rain. When,
A cab side outer bonded to the outer surface of the hollow portion of the side sill rain,
It is a vehicle equipped with
The first flange portion and the second flange portion are spot welded at a plurality of flange welding points arranged at regular intervals in the front-rear direction.
The cab side outer is spot-welded to the side sill rain at a plurality of welding points arranged at regular intervals in the front-rear direction.
A vehicle characterized in that the distance between adjacent flange welding points is narrower than the distance between adjacent flange welding points.

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