Welding device and welding method

Abstract

To propose a welding device and a welding method capable of preventing and correcting shaft deviation and tilting of an insertion member such as a weld bolt.SOLUTION: There is provided a welding device which is configured to weld an insertion member 7 to a plate material 15 by: inserting a vertically movable guide pin 8 to a hole 15a formed on the plate material 15 arranged to be in contact with a lower electrode 2, so as to bring a shaft part 7a of the insertion member 7 into contact with the guide pin 8; then, lowering the guide pin 8; and energizing an upper electrode 3 in a state of pressing the insertion member 7 against the plate material 15 side. An engagement recess 16 is provided at the center of an end surface 7d of the insertion member 7, a first annular plane part 17 is provided around the engagement recess. An engagement protrusion 20 that can engage with the engagement recess 16 is provided on an end surface 8a of the guide pin 8. A second annular plane part 21 is provided around the engagement protrusion, and a shoulder part 22 is provided on the outer edge of the second annular plane part.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a welding apparatus and a welding method. [Background technology]

[0002] 2. Description of the Related Art In recent years, projection welding using a weld bolt has been adopted as a method for welding and fixing a bolt to a metal plate in a state in which the bolt is in the metal plate.

[0003] A weld bolt is composed of a shaft portion with a male thread and a flange portion provided at the end of the shaft portion, with multiple protrusions provided on the side surface of the flange portion. A welding method is used in which this weld bolt is inserted into a hole formed in a metal plate material, and with the protrusions of the flange portion in contact with the plate material, pressure is applied and electricity is passed through to melt the protrusions and weld the weld bolt to the plate material.

[0004] It is common practice to clamp the weld bolt between an upper electrode that can be raised and lowered in the vertical direction and a guide pin that is biased upward, insert the weld bolt into a hole in a plate material abutting the lower electrode, and pass electricity between the upper and lower electrodes while the flange protrusion is pressed firmly against the surface of the plate material.

[0005] In order to prevent the axial misalignment of the weld bolt when it is clamped between this upper electrode and a guide pin biased upward, it has been proposed to provide a recess on the bottom surface of the shaft of the weld bolt and to form a conical pointed portion at the tip of the guide pin that fits into the recess of the weld bolt, thereby fitting them together (see Patent Document 1).

[0006] In addition, in order to prevent axial misalignment of the weld bolt when it is clamped between the upper electrode and a guide pin biased upward, it has been proposed to form a mating recess with a flat bottom surface in the center of the upper end of the guide pin and to fit the tip of the weld bolt into the mating recess (see Patent Document 2). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 62-127380 [Patent Document 2] Japanese Utility Model Application Publication No. 1-165181 Summary of the Invention [Problem to be solved by the invention]

[0008] The methods described in Patent Documents 1 and 2 above can prevent axial misalignment of the weld bolt, but cannot prevent or correct tilt of the weld bolt, which may result in welding defects due to current shunting (short circuit) or reduced installation accuracy of the weld bolt.

[0009] Therefore, an object of the present invention is to provide a welding device and a welding method capable of preventing and correcting axial misalignment and inclination of an insertion member such as a weld bolt. [Means for solving the problem]

[0010] In order to solve the above problems, the present invention provides a welding device which inserts a guide pin movable in the vertical direction into a hole formed in a plate material arranged to abut against a lower electrode, brings a shaft portion of an inserting member having a flange with a diameter larger than that of the hole into abutment against the guide pin, lowers the guide pin, inserts the inserting member into the hole, and then applies current while pressing the flange against the plate material with an upper electrode, thereby welding the inserting member to the plate material, a first annular flat portion is provided around the end surface of the shaft portion, the first annular flat portion being flat on the periphery of the engagement recess, the first annular flat portion being flat on the periphery of the engagement recess, This welding device is characterized in that an engaging convex portion capable of engaging with the engaging recess is provided at the center of the end face of the guide pin, a flat second annular flat portion is provided around the engaging convex portion, and a shoulder portion is provided on the outer edge of the second annular flat portion, the shoulder portion being positioned lower as it moves radially outward from the axis of the guide pin.

[0011] The insertion member may be a weld bolt.

[0012] Also, a welding device includes a guide pin movable in the vertical direction that is inserted into a hole formed in a plate material that is disposed so as to abut against a lower electrode, an insertion member having a flange with a diameter larger than that of the hole is abutted against the guide pin, the guide pin is then lowered to insert the insertion member into the hole, and current is passed while the flange is pressed against the plate material by an upper electrode to weld the insertion member to the plate material, a conical engagement recess is provided at the center of an end face of a shaft portion that is inserted into the hole of the insertion member, and a first annular flat portion is provided around the engagement recess; a welding device that provides an engaging protrusion that can engage with the engaging recess at the center of an end face of the guide pin, provides a second annular flat portion around the engaging protrusion, and provides a shoulder portion on an outer edge of the second annular flat portion that is positioned downward as it moves radially outward from the axis of the guide pin, This is a welding method in which the engaging recess of the inserting member is engaged with the engaging protrusion of the guide pin, and the first annular flat portion of the inserting member is maintained in contact with the second annular flat portion of the guide pin while pressure is applied and electricity is passed through, thereby welding the inserting member to the plate material. Effect of the Invention

[0013] In the present invention, an engagement recess having a conical inner surface is provided in the center of the end face of the shaft portion that is inserted into the hole of the inserting member, and a first planar first annular flat surface portion is provided around the engagement recess, and an engagement protrusion that can engage with the engagement recess is provided in the center of the end face of the guide pin, and a second planar first annular flat surface portion is provided around the engagement protrusion.As a result, when the inserting member is clamped between the upper electrode and the guide pin, the engagement recess of the inserting member engages with the engagement protrusion of the guide pin, and the first annular flat surface portion of the inserting member abuts against the second annular flat surface portion of the guide pin, making it possible to prevent and correct axial misalignment and inclination of the inserting member. [Brief description of the drawings]

[0014] [Figure 1] 1 is a partial vertical sectional view of a welding device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a partial vertical sectional view for explaining a welding method according to an embodiment of the present invention. [Diagram 3] 3 is a partial vertical cross-sectional view of a state in which an insertion member is attached to the state shown in FIG. 2; [Figure 4] FIG. 4 is a partial vertical cross-sectional view of the state in which the upper electrode is lowered from the state in FIG. 3 . [Diagram 5] FIG. 2 is a partial vertical cross-sectional view of the state shown in FIG. 1 when a current is passed between the electrodes. [Figure 6] FIG. 4 is a side view of an insertion member and a guide pin used in the embodiment of the present invention. [Figure 7] FIG. 7 is a bottom view of the insertion member of FIG. 6 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a welding device according to the present invention will be described with reference to the accompanying drawings.

[0016] FIG. 1 is a vertical cross-sectional view of a welding device 1 according to an embodiment of the present invention.

[0017] 1 and 2 to 6, the welding device 1 has a fixedly installed lower electrode 2. The lower electrode 2 is provided at its center with an insertion hole 2a that penetrates in the vertical direction.

[0018] The lower electrode 2 has a central axis XX, and the upper electrode 3, whose central axis XX is positioned coaxially with the lower electrode 2, is provided so as to be movable in the up and down direction by a moving part (not shown).

[0019] A cylindrical guide pipe 5 made of an insulating material is fixed in the insertion hole 2a, and an upper end 5a of the guide pipe 5 is located lower than an upper end 2b of the lower electrode 2. The inner diameter of a hollow portion 6, which is provided in the center of the guide pipe 5 and is open at the top and bottom, is the same as or slightly larger than the outer diameter of an insertion member 7 described later.

[0020] A cylindrical guide pin 8 is provided slidably in the vertical direction within the hollow portion 6 of the guide pipe 5. The guide pin 8 is biased upward by a biasing portion 10 such as a spring, air pressure, or hydraulic pressure.

[0021] A magnet 12 is provided radially outwardly of the lower electrode 2 about the central axis XX such that its upper end 12a is at the same height as an upper end 2b of the lower electrode 2.

[0022] A hole 15a is formed through the plate material 15 to which the inserting member 7 is welded at a position where the inserting member 7 is welded to the plate material 15. The inserting member 7 has a shaft portion 7a with a male thread on its outer circumferential surface, and a flange 7b that is provided at the end of the shaft portion 7a and has an outer diameter larger than that of the shaft portion 7a. A plurality of projections 7c are fixedly provided circumferentially on the side surface of the shaft portion 7a of the flange 7a so as to protrude toward the shaft portion 7a.

[0023] In this embodiment, a weld bolt is used as the insertion member 7, but any member can be used as long as it has a shaft portion that can be inserted into the hole 15a of the plate material 15 and a flange portion, such as a weld pin.

[0024] An engagement recess 16 formed of a conical inner surface is formed in the center of an end face 7d of the shaft portion 7a of the insertion member 7 opposite the flange 7b. A flat first annular flat portion 17 is formed around the engagement recess 16. A tapered portion 18 is formed on the outer edge of the first annular flat portion 17, which is located closer to the flange 7b as it moves outward in the radial direction centered on the central axis of the shaft portion 7a.

[0025] A conical engaging protrusion 20 that engages with the engaging recess 16 of the insertion member 7 is provided at the center of the tip surface 8a, which is the end surface of the guide pin 8. A flat second annular flat portion 21 is formed around the engaging protrusion 20. A tapered shoulder portion 22 is formed on the outer edge of the second annular flat portion 21, which is positioned lower as it moves radially outward from the axis XX of the guide pin as its center.

[0026] Next, a welding method using the welding device 1 will be described.

[0027] 2, the guide pin 8 is biased upward by a biasing unit 10, and its tip surface 8a protrudes upward from the upper end 2b of the lower electrode 2. In addition, the upper electrode 3 is disposed so as to be spaced a predetermined distance from the lower electrode 2 by a moving unit (not shown).

[0028] 2, plate material 15 is set so that guide pin 8 is positioned in hole 15a of plate material 15. The lower surface of plate material 15 abuts against upper end 2 of lower electrode 2 due to the attraction force of magnet 12, and the position is maintained.

[0029] By forming a tapered shoulder portion 22 on the outer periphery of the end face of the guide pin 8, the guide pin 8 can be smoothly inserted into the hole 15a of the plate material 15 without getting caught on the plate material 15 when the guide pin 8 is inserted into the hole 15a.

[0030] Next, as shown in FIG. 3, the inserting member 7 is attached by a moving means (not shown) so that the engagement recess 16 of the inserting member 7 engages with the engagement protrusion 20 of the guide pin 8 relative to the tip surface 8a of the guide pin 8, and so that the first annular flat surface portion 17 of the inserting member 7 abuts against the second annular flat surface portion 21 of the guide pin 8.

[0031] Next, as shown in FIG. 4, the upper electrode 3 is moved downward by a moving part (not shown) so that the lower surface of the upper electrode 3 is abutted against the surface opposite the shaft portion 7a of the flange 7b of the inserting member 7, and the inserting member 7 is clamped between the upper electrode 3 and the guide pin 8.

[0032] The inserting member 7 is attached to the guide pin 8 so that the engagement recess 16 of the inserting member 7 engages with the engagement protrusion 20 of the guide pin 8 and the first annular flat portion 17 of the inserting member 7 abuts against the second annular flat portion 21 of the guide pin 8.

[0033] Next, as shown in FIG. 1, the upper electrode 3 is moved downward along the inner surface of the hollow portion 6 of the guide pipe 5 against the inertial force of the biasing portion 10 by a moving portion (not shown), so that the protrusion 7c of the insertion member 7 is brought into contact with the upper surface of the plate material 15 and pressed downward.

[0034] With the protrusion 7c of the inserting member 7 pressed against the upper surface of the plate material 15, electricity is passed between the upper electrode 2 and the lower electrode 3 to melt the protrusion 7c and weld the flange portion 7b of the inserting member 7 to the plate material 15, as shown in Figure 5.

[0035] By attaching the inserting member 7 to the guide pin 8 so that the engaging recess 16 of the inserting member 7 and the engaging protrusion 20 of the guide pin 8 are engaged and the first annular flat portion 17 of the inserting member 7 and the second annular flat portion 21 of the guide pin 8 are abutted, when the inserting member 7 is clamped by the upper electrode 3 and the guide pin 8, the axes of the inserting member 7 can be positioned on a straight line by the upper electrode 3 and the guide pin 8, and the axial deviation and inclination of the inserting member 7 can be prevented and corrected, and the occurrence of shunting (short circuit) can be suppressed, and the occurrence of welding defects can be suppressed. Also, the attachment accuracy of the inserting member 7 to the plate material 15 can be maintained high. [Explanation of symbols]

[0036] 1 Welding equipment 2 Lower electrode 3 Upper electrode 7 Insertion member 7a Shaft 7b Flange 8 Guide pin 15 Board material 15a hole 16 Engagement recess 17 First annular flat section 20 Engagement protrusion 21 Second annular flat surface 22 Shoulder

Claims

1. A welding device comprising: a guide pin movable in a vertical direction is inserted into a hole formed in a plate material arranged to abut against a lower electrode; a shaft portion of an inserting member having a flange with a diameter larger than that of the hole is abutted against the guide pin; the guide pin is then lowered to insert the inserting member into the hole; and an electric current is then applied while the flange is pressed against the plate material by an upper electrode to weld the inserting member to the plate material, a first annular flat portion is provided around the end surface of the shaft portion, the first annular flat portion being flat on the periphery of the engagement recess, the first annular flat portion being flat on the periphery of the engagement recess, a second annular flat portion around the center of the end face of the guide pin, the second annular flat portion having a flat surface, and a shoulder portion located downward as it moves radially outward from the axis of the guide pin.

2. 2. The welding device according to claim 1, wherein the insertion member is a weld bolt.

3. A welding device comprising: a guide pin movable in a vertical direction is inserted into a hole formed in a plate material disposed so as to abut against a lower electrode; an inserting member having a flange with a diameter larger than that of the hole is abutted against the guide pin; the guide pin is then lowered to insert the inserting member into the hole; and an upper electrode is pressed against the flange toward the plate material while an electric current is applied to weld the inserting member to the plate material, a conical engagement recess is provided at the center of an end face of a shaft portion that is inserted into the hole of the insertion member, and a first annular flat portion is provided around the engagement recess; a welding device that provides an engaging protrusion that can engage with the engaging recess at the center of an end face of the guide pin, provides a second annular flat portion around the engaging protrusion, and provides a shoulder portion on an outer edge of the second annular flat portion that is positioned downward as it moves radially outward from the axis of the guide pin, A welding method in which an engagement recess of the insertion member is engaged with an engagement protrusion of the guide pin, and a first annular flat portion of the insertion member is maintained in contact with a second annular flat portion of the guide pin while applying pressure and electricity to weld the insertion member to the plate material.

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