JP2008302425A - Hollow steel plate welding equipment and welding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To weld a hollow steel plate part in which a welding current in a plate thickness direction is applied to a steel plate at a welding location and an abnormal deformation of the hollow steel plate part is prevented by pressurization of an electrode so that a welding state having a high welding strength is obtained An apparatus and a welding method are provided.
Parts 9 and 60 are welded to the outer surface of a steel plate part 8 having an internal space 20 by electric resistance welding, the deformation of the steel plate part 8 due to electrode pressurization is prevented, and the welding current is supplied to the plate of the steel plate. A reinforcing conducting member 33 that is energized in the thickness direction and inserted into the internal space 20 is provided, and the welding current is energized by pressurizing the components 9 and 60 on the outer surface of the steel plate component 8 facing the reinforcing conducting member 33. A movable electrode 6 is provided.
[Selection] Figure 1

Description

  The present invention relates to a welding apparatus and a welding method for a hollow steel plate part for welding a part to an outer surface of a steel sheet part provided with an internal space by electric resistance welding.

A steel plate component is inserted between the movable electrode and the fixed electrode, and the component is welded or the steel plates are welded to each other. By the way, there are various shapes of steel plate components, and depending on the shape, the electrode may not be inserted into a predetermined location. In preparation for such a case, as shown in JP-A-2005-238317, an auxiliary electrode is inserted into a predetermined location and the electrode is pressurized thereto.
JP 2005-238317 A

  The auxiliary electrode as described above assists in applying a welding current by pressurizing the welding local part, and cannot solve the problems peculiar to the hollow steel plate part having the internal space. When parts such as projection bolts, projection nuts or clamp fittings are welded to the outer surface of such hollow steel plate parts by electric resistance welding, heat is generated efficiently at the weld local area, and the hollow shape of the steel plate parts is also achieved. Therefore, it should be ensured that no abnormal deformation occurs due to electrode pressurization. At the same time, the welding process must proceed smoothly to improve productivity.

  The present invention is provided in order to solve the above-described problems, and applies a welding current in the plate thickness direction to a steel plate at a welding location, and prevents abnormal deformation of the hollow steel plate component by pressing the electrode. An object of the present invention is to provide a welding apparatus and a welding method for a hollow steel plate part capable of obtaining a welding state with high welding strength.

Means to solve the problem

  The invention according to claim 1 is an invention of a welding apparatus for welding a part to an outer surface of a steel sheet part having an internal space by electric resistance welding, and preventing the deformation of the steel sheet part due to electrode pressurization. A movable conducting member is provided to energize the plate in the thickness direction of the steel plate component and a reinforcing conducting member to be inserted into the internal space, and pressurize the component on the outer surface of the steel plate component facing the reinforcing conducting member to energize the welding current. An apparatus for welding hollow steel plate parts, wherein an electrode is provided.

The invention's effect

  When the movable electrode is pressed against the outer surface of the steel plate component and a welding current is applied by the operation of the movable electrode, the steel plate of the steel plate component is sandwiched between the component and the reinforcing conductive member. The current flows in a direction penetrating the plate thickness of the steel plate part. Therefore, the current density of the welding current can be maintained high, and Joule heat generation is performed efficiently. If the current is applied in the plane direction of the steel sheet without being energized in the thickness direction in this way, the current density in the steel plate portion where the part is pressed decreases, so that sufficient heat generation cannot be obtained. . Therefore, it is necessary to increase the current value or lengthen the energization time, which is uneconomical because productivity is not improved.

  Since the reinforcing conducting member is inserted into the internal space, deformation of the steel sheet component due to electrode pressurization can be prevented, and a sufficient pressure can be obtained. For this reason, the fusion | melting part of a component and a steel plate becomes a predetermined fusion | melting area and fusion | melting depth, and is effective in improving welding strength.

  Furthermore, since heat at the time of welding is transferred from the inner surface of the steel plate to the reinforcing conductive member, overheating of the molten portion is suppressed. In other words, if the energizing time of the welding current is lengthened or the current value of the welding current is increased depending on the shape of the part, etc., the steel sheet will be melted excessively and the entire plate thickness will be melted, ensuring the welding strength of the part. It will not be possible. However, according to the present invention, the reinforcing conductive member that is in close contact with the inner surface of the steel sheet performs a function of taking away excessive heat, that is, a function like a cooling metal, thereby preventing the entire plate thickness from melting. it can. In particular, such a cooling function is important when the thickness of the steel plate is thin, and is useful when welding a part having a large thermal mass to the thin steel plate.

  According to a second aspect of the present invention, a pressure receiving member that is in close contact with the inner surface of the internal space is provided on the reinforcing conductive member, and an expansion means is provided for bringing the pressure receiving member into close contact with the inner surface of the internal space. It is a welding apparatus of the hollow steel plate components of description.

  As described above, since the pressure receiving member is brought into close contact with the inner surface of the internal space by the expansion operation of the expansion means, the steel plate at the welded portion is securely sandwiched between the component and the pressure receiving member, and the welding current is reliably supplied in the thickness direction of the steel plate. The And, due to the close contact of the pressure receiving member, deformation of the steel plate part is prevented and sufficient pressurizing force is obtained, and the melted part between the part and the steel plate has a predetermined melt area and melt depth, which is effective for increasing the welding strength. It is.

  Furthermore, the expansion means can be inserted into the internal space in a contracted state and expanded at a predetermined location. By performing such an operation, it is possible to smoothly insert the reinforcing conductive member even in the case of an internal space where the passing dimension of the reinforcing conductive member at the entrance location is small and the depth is large. Thus, energization in the plate thickness direction and a predetermined molten state can be secured.

  According to a third aspect of the present invention, the reinforcing conduction member is provided with a pressure receiving member that is in close contact with the inner surface of the internal space, and disappears due to elastic deformation of the steel plate by pressurization of an electrode between the pressure receiving member and the inner surface of the internal space. The hollow steel plate part welding apparatus according to claim 1, wherein an air gap is provided.

  When the steel plate is elastically deformed by pressurization of the electrode and the gap disappears, the steel plate is sandwiched between the component and the pressure receiving member, so that the melted portion of the component and the steel plate has a predetermined melting area and melting depth. It is effective to increase the welding strength. When the pressurization of the electrode is released, the steel plate elastically returns to a predetermined shape, and a predetermined part shape can be secured. Further, since the reinforcing conductive member is smaller in size than the internal space, it can be smoothly inserted into and extracted from the internal space.

  According to a fourth aspect of the present invention, the component includes a shaft portion on which a male screw is formed, a flange portion provided integrally with the shaft portion, and a welding protrusion formed on a flange surface opposite to the shaft portion. It is a projection bolt which has this. It is a welding apparatus of the hollow steel plate components in any one of Claims 1-3.

  As described above, since the steel plate is securely sandwiched between the welding projection and the reinforcing conductive member, the welding projection portion and the steel plate are properly melted to obtain a normal welding state. And by such a welding state, a flange part will closely_contact | adhere to a steel plate, or it will be a grade which a slight space | gap exists between a flange part and a steel plate surface. Therefore, the welding strength of the projection bolt can be sufficiently obtained.

  The invention of claim 5 is the hollow steel plate part welding apparatus according to any one of claims 1 to 4, wherein the steel plate part is a pipe member having a circular cross section.

  Normal welding can be obtained without deforming the circular cross-sectional shape by interposing the reinforcing conductive member.

  A sixth aspect of the present invention is the hollow steel plate part welding apparatus according to any one of the first to fourth aspects, wherein the steel plate part is formed by integrating a plurality of steel plate members.

  In the case of a steel plate part in which a plurality of steel plate members are integrated by spot welding or the like, the steel plate part itself has a complicated shape and the internal space has various shapes. However, according to the present invention, even in such an internal space, good energization and component pressurization are possible as described above.

  The invention according to claim 7 is an invention of a welding method, wherein a part is welded to an outer surface of a steel sheet part having an internal space by electric resistance welding, and the deformation of the steel sheet part due to electrode pressurization is prevented and welding is performed. A reinforcing conducting member for energizing current in the plate thickness direction of the steel plate part is inserted into the internal space, the part is pressed by pressing a part with a movable electrode on the outer surface of the steel plate part facing the reinforcing conducting member and energizing the welding current. A welding method for a hollow steel plate part, characterized by welding to an outer surface of the steel plate part.

  The effect of the welding method according to the invention is the same as the effect of the welding device according to the invention. The operational effects of the method invention described in claims 8 to 12 are the same as the operational effects of the device invention described in claims 2 to 6.

  Next, the best mode for carrying out the welding apparatus and welding method for hollow steel plate parts of the present invention will be described.

  The basic structure of the welding apparatus will be described.

  There are various types of welding equipment, such as those in which movable and fixed electrodes are arranged on a column that stands up from the floor, and those in which movable and fixed electrodes are arranged on a C-shaped member and operated by a robot device. There is. The thing of a present Example is the former stationary welding apparatus. The entire welding apparatus is indicated by reference numeral 100.

  This will be described with reference to FIG. Arm members 3, 4 extending in the lateral direction are provided on the support column 2 standing on the floor 1, and the movable electrode 6 is advanced and retracted in a substantially vertical direction by an air cylinder 5 fixed to the arm member 3. The other arm member 4 is provided with a fixed electrode 7 on which a steel plate component 8 is held.

  As parts to be welded to the steel plate part 8, there are various parts such as a projection bolt, a projection nut, and an elongated clamp fitting. Here, it is a projection bolt indicated by reference numeral 9. In the following description, the projection bolt may be simply expressed as a bolt.

  The bolt 9 is inserted into and held in a substantially vertical receiving hole 10 provided in the movable electrode 6. The receiving hole 10 opens downward in the center of the lower end surface of the movable electrode 6.

  In order to insert the bolt 9 into the receiving hole 10, a component supply unit 200 is provided. A holding head 13 that holds the bolt 9 is attached to the tip of the supply rod 12 that moves forward and backward in an oblique direction. The supply rod 12 advances and stops at a position where the bolt 9 is coaxial with the receiving hole 10. Thereafter, the entire supply rod 12 is raised and the bolt 9 is inserted into the receiving hole 10.

  In order to perform the operation as described above, the supply rod 12 is moved back and forth by the air cylinder 14 disposed in an oblique direction. And the raising / lowering air cylinder 16 is fixed to the stationary member 15, The piston rod 17 advances / retreats to a substantially perpendicular direction. A bracket 18 is fixed to the air cylinder 14, and a piston rod 17 is coupled thereto.

  Next, the shape of the steel plate part will be described.

  As the steel plate component 8, there are various types as shown in FIG. A pipe material 21 having a circular cross section having an internal space 20 is shown in FIG. In FIG. 5B, a plurality of steel plate members 22, 23 are integrated by spot welding or the like, the steel plate member 22 is flat, and the steel plate member 23 has a hat-shaped cross section having flanges on both sides. It is. The internal space 20 is formed by such a combination. Furthermore, what is shown in FIG. 5C is a steel plate member 24 having a bowl shape, and an internal space 20 is formed between the flange portion and the steel plate member 22.

  Next, the projection bolt will be described.

  The bolt 9 is made of iron. As shown in FIG. 7D, the shaft portion 25 formed with a male screw, the circular flange portion 26 provided integrally with the shaft portion 25, and the shaft portion 25 are opposite to each other. It has a welding protrusion 27 that is circular and concentric with the shaft portion 25 formed on the side flange surface. And the end surface of the welding protrusion 27 is made into the taper surface 28, and the top part 29 is formed in the center part. An annular inclined surface 30 is provided on the outer periphery of the tapered surface 28. The top portion 29 has a sharp shape, but may be a circular flat portion having a small diameter. As for the dimensions of each part, the diameter D1 of the shaft part 25 is 6 mm, the length L of the shaft part 25 is 23 mm, the diameter D2 of the flange part 26 is 11 mm, the diameter D3 of the tapered surface 28 is 5.5 mm, and the root of the welding protrusion 27 The diameter D4 of the portion is 7.5 mm, the thickness T of the flange portion 26 is 1 mm, and the height H of the welding protrusion 27 is 1.5 mm.

  Next, the reinforcing conductive member will be described.

  The reinforcing conducting member prevents the deformation of the steel plate part, that is, the pipe member 21 due to the pressurization of the movable electrode 6 and allows the welding current to flow in the plate thickness direction of the steel plate and is inserted into the internal space 20. There are various structures, such as those in which the effective dimension of the reinforcing conductive member is changed by the expansion means, and those in which the dimension of the internal space is made smaller in advance. The case shown in FIGS. 1 and 2 is a case having an expansion means.

  As shown in FIG. 1, the steel plate component 8 here is the pipe member 21 having a circular cross section shown in FIG. The outer diameter of the pipe member 21 is 50 mm, and the thickness of the steel plate is 2 mm. A V-shaped receiving surface 31 is formed on the fixed electrode 7 so that the pipe member 21 does not roll and be displaced. Further, a permanent magnet 32 is fixed in the back of the receiving hole 10 of the movable electrode 6 so that the bolt 9 does not fall from the receiving hole 10 due to the attractive force.

  The entire reinforcing conductive member is denoted by reference numeral 33. A cylindrical main body 34 to be inserted into the pipe member 21 is provided. The main body 34 is arranged such that the axis of the cylinder faces the diameter direction of the pipe member 21. A piston 35 is inserted into the main body 34 in a slidable state. A pressure receiving member 37 is attached to a piston rod 36 coupled to the piston 35. The pressure receiving member 37 is slidably inserted into a through hole 39 formed in the end plate 38 of the main body 34, and its upper surface is an arc surface that can be in close contact with the inner cylindrical surface of the pipe member 21. This sliding portion is conductive.

  An eccentric cam 40 is brought into contact with the lower surface of the piston 35, and a support shaft 41 is installed on the main body 34. When the eccentric cam 40 rotates about the support shaft 41, the piston 35 and the pressure receiving member 37 advance and retreat by the lift of the eccentric cam 40. An operating rod 42 is fixed to the main body 34 so that the entire reinforcing conductive member 33 can be inserted into or extracted from the internal space 20. The operating arm 43 is attached to the eccentric cam 40, and the eccentric cam 40 rotates by swinging the operating arm 43. An actuator 44 composed of an electromagnetic solenoid, an air cylinder, or the like is coupled to the operation rod 42, and its output is transmitted to the operation arm 43 via the transmission rod 45. Here, the actuator 44 is composed of an air cylinder.

  A seat portion 47 having a thick structure is formed in the lower portion of the main body 34. The lower surface of the seating portion 47 is an arc surface so as to be in close contact with the inner cylindrical surface of the pipe member 21. A notch 48 is formed in a part of the seat 47, and the transmission rod 45 moves forward and backward through this. In order to impart conductivity to the reinforcing conducting member 33, at least the pressure receiving member 37 and the main body 34 are made of a copper alloy having good conductivity.

  A compression coil spring 49 is inserted between the inner surface of the end plate 38 and the upper surface of the piston 35, and the piston 35 is always in pressure contact with the eccentric cam 40 by its tension.

  In addition, the code | symbol 50 is a transformer and welding current is supplied with the conducting wires 51 and 52. FIG.

  The operation of the reinforcing conductive member 33 will be described.

  When the rotational position of the eccentric cam 40 is a position where the lift is small, the pressure receiving member 37 is retracted by the tension of the compression coil spring 49 as shown by a two-dot chain line in FIG. That is, the reinforcing conductive member 33 is in a contracted state. In such a state that the pipe member 21 is contracted outside the pipe member 21, the operating rod 42 is moved to insert the reinforcing conductive member 33 into the internal space 20, and the insertion is stopped at a position facing the movable electrode 6. Since the reinforcing conductive member 33 is thus contracted, the reinforcing conductive member 33 can be easily inserted into the internal space 20.

  After the insertion of the reinforcing conducting member 33 is stopped as described above, when the eccentric cam 40 is rotated by the operation of the actuator 44, the piston 35 is pushed out from the main body 34 while compressing the compression coil spring 49, The pressure receiving member 37 is in pressure contact with the inner cylindrical surface of the pipe. At the same time, the lower surface of the seat 47 is pressed against the inner cylindrical surface of the pipe. In this way, the reinforcing conductive member 33 and the movable electrode 6 are in a positional relationship facing each other, and the welding projection 27 of the bolt 9 is pressurized on the outer surface of the pipe steel plate facing the reinforcing conductive member 33 and the welding current is applied. It becomes.

  As described above, the steel plate of the pipe member 21 is securely sandwiched between the welding protrusion 27 of the bolt 9 and the pressure receiving member 37. When a welding current is passed in this state, the current flows through the steel plate in a direction penetrating the plate thickness. Therefore, the current density in the steel plate portion is increased, and effective welding heat is obtained.

  After the welding is completed, the eccentric cam 40 is turned to reduce the reinforcing conductive member 33 again, and is extracted from the internal space 20.

  As apparent from the structure and operation as described above, the expansion means is formed by the main body 34, the piston 35, the piston rod 36, the pressure receiving member 37, the eccentric cam 40, the actuator 44, the transmission rod 45, and the like.

  Another reinforcing conductive member will be described.

  The reinforcing conducting member 33 shown in FIG. 1 operates with the eccentric cam 40, whereas the reinforcing conducting member 33 shown in FIG. 2 operates with fluid pressure. Here, it is hydraulically operated. That is, a hydraulic cylinder 54 is provided in the main body 34, a hydraulic piston 55 is inserted therein, and a pressure receiving member 37 is attached to the upper end of the piston 55. A seating portion 47 is formed below the hydraulic cylinder 54.

  An oil passage 56 communicating with the hydraulic cylinder 54 is provided in the seating portion 47, and a hydraulic hose 57 is connected thereto. An operation rod 42 is coupled to the hydraulic cylinder 54.

  When the hydraulic pressure is lowered, the hydraulic piston 55 is lowered and the reinforcing conducting member 33 is contracted. Further, when the hydraulic pressure is increased, the hydraulic piston 55 rises and the reinforcing conductive member 33 is expanded. The other configuration is the same as that of the embodiment shown in FIG. 1 including the parts not shown, and the same reference numerals are given to members having similar functions. The operational effects are also the same as in the embodiment shown in FIG.

  As is apparent from the structure and operation as described above, the expansion means is formed by the main body 34, the hydraulic cylinder 54, the hydraulic piston 55, the pressure receiving member 37, and the like.

  Furthermore, another reinforcing conductive member will be described.

  Differences from the reinforcing conductive member described above will be described. The reinforcing conductive member 33 shown in FIG. 3 is of a type that does not include expansion means. The height of the reinforcing conductive member 33 is set to a value slightly smaller than the inner diameter of the pipe member 21. Therefore, when the reinforcing conducting member 33 is inserted into the internal space 20, a slight gap S is formed between the inner cylindrical surface of the pipe member 21. Here, the gap S is 0.5 mm. Other configurations are the same as those of the embodiments shown in FIGS. 1 and 2 including the portions not shown, and members having the same functions are denoted by the same reference numerals.

  Since the gap S is thus provided, the reinforcing conductive member 33 can be smoothly inserted into the internal space 20. When the movable electrode 6 is pressurized, the pipe member 21 is elastically deformed so that the gap S disappears. Thereafter, a welding current is applied and the bolt 9 is welded. When the pressurization of the movable electrode 6 is released, the pipe member 21 returns to its original shape due to its elasticity. Other functions and effects are the same as those of the embodiments shown in FIGS.

  Next, the welding state will be described.

  FIG. 6 is a cross-sectional view showing a welded state. As described above, since the steel plate of the pipe member 21 is reliably pressurized between the welding protrusion 27 and the pressure receiving member 37, the penetration portion 58 has a sufficient depth. This depth is indicated by reference numeral T1 on the flange portion 26 side and indicated by reference numeral T2 on the steel plate side. Observing the melting phenomenon over time, when the welding projection 27 is melting, there are few places where the heat of fusion escapes in the vicinity of the flange portion 26, so that a larger amount of metal is melted. On the other hand, since the heat of fusion diffuses in the surface direction on the steel plate side, the amount of molten metal on the steel plate side is smaller than that on the flange portion 26 side. When the pressurization proceeds reliably in the state of such a phenomenon, this time, the molten metal on the flange portion 26 side flows while being pushed into the steel plate side, and finally, as shown in FIG. Is T1 <T2. Thus, welding strength can be raised by the penetration depth to the steel plate side becoming large. Furthermore, the gap formed between the outer peripheral portion of the flange portion 26 and the surface of the pipe member 21 is eliminated or made as small as possible by flowing more molten metal on the flange portion 26 side toward the steel plate side. Is possible.

  The embodiment shown in FIG. 5 is a case where a block-shaped reinforcing conducting member 33 is inserted into the internal space 20 of the steel plate part 8 shown in FIG. Although not shown here, a gap corresponding to the aforementioned gap S is provided. The operational effects in this embodiment are the same as those in FIG.

  It is also possible to provide a receiving hole on the fixed electrode 7 side, insert the shaft portion 25 therein, and dispose the steel plate component 8 thereon for welding. A nut 60 described later may be disposed in place of the shaft portion 25.

  The operational effects of the first embodiment described above are as follows.

  When the welding protrusion 27 of the bolt 9 is pressed on the outer surface of the steel plate and the welding current is applied by the operation of the movable electrode 6, the steel plate of the pipe member 21 is welded to the welding protrusion 27 and the pressure receiving member 37 of the reinforcing conducting member 33. Therefore, the welding current flows in a direction penetrating the plate thickness of the steel plate. Therefore, the current density of the welding current can be maintained high, and Joule heat generation is performed efficiently. If it is not energized in the sheet thickness direction and energized in the surface direction of the steel sheet in this way, the current density in the steel sheet portion where the welding protrusions 27 are pressed decreases, so that sufficient heat generation cannot be obtained. It will be. Therefore, it is necessary to increase the current value or lengthen the energization time, which is uneconomical because productivity is not improved.

  Since the reinforcing conducting member 33 is inserted into the internal space 20, it is possible to prevent deformation of the steel sheet component due to the electrode pressurization, to perform a sufficient reinforcing function, and to obtain an appropriate pressurizing force. For this reason, the penetration part 58 of the welding protrusion 27 and the steel plate has a predetermined melting area and melting depths T1 and T2, which is effective in increasing the welding strength.

  Furthermore, since heat at the time of welding is transferred from the inner surface of the steel plate to the reinforcing conductive member, overheating of the molten portion is suppressed. In other words, if the energizing time of the welding current is lengthened or the current value of the welding current is increased depending on the shape of the part, etc., the steel sheet will be melted excessively and the entire plate thickness will be melted, ensuring the welding strength of the part. It will not be possible. However, according to the present embodiment, the pressure receiving member 37 that is in close contact with the inner surface of the steel plate performs a function of taking away excessive heat, that is, a function like a cooling metal, thereby preventing the entire plate thickness from melting. Can do. In particular, such a cooling function is important when the thickness of the steel plate is thin, and is useful when welding a part having a large thermal mass to the thin steel plate.

  The reinforcing conduction member 33 is provided with a pressure receiving member 37 that is in close contact with the inner surface of the internal space 20, and an expansion means is provided for bringing the pressure receiving member 37 into close contact with the inner surface of the internal space 20.

  Since the pressure receiving member 37 is brought into close contact with the inner surface of the internal space 20 by the expansion operation of the expansion means in this way, the steel plate at the welded portion is securely sandwiched by the welding protrusion 27 and the pressure receiving member 37 and welded in the thickness direction of the steel plate. The current is reliably energized. Then, due to the close contact of the pressure receiving member 37, deformation of the steel plate part 8 is prevented and sufficient pressurizing force is obtained, so that the melted portion 58 between the part and the steel plate has a predetermined melting area and melting depths T1 and T2, and welding strength is increased. It is effective to raise.

  Furthermore, the expansion means can be inserted into the internal space 20 in a contracted state and expanded at a predetermined location. By performing such an operation, it is possible to smoothly insert the reinforcing conductive member 33 even in the case of the internal space 20 in which the passing dimension of the reinforcing conductive member 33 at the entrance portion is small and the depth is large. Thus, energization in the thickness direction as described above and a predetermined molten state can be secured.

  The reinforcing conduction member 33 is provided with a pressure receiving member 37 that is in close contact with the inner surface of the internal space 20, and disappears due to elastic deformation of the steel plate due to pressurization of the movable electrode 6 between the pressure receiving member 37 and the inner surface of the internal space 20. A space S is provided.

  When the steel plate is elastically deformed by the pressurization of the movable electrode 6 and the gap S disappears, the steel plate is sandwiched between the welding protrusion 27 and the pressure receiving member 37, so that the welded portion 58 between the flange portion 26 and the steel plate 58. Has a predetermined melting area and melting depths T1 and T2, which is effective in increasing the welding strength. When the pressurization of the movable electrode 6 is released, the steel plate elastically returns to a predetermined shape, and a predetermined part shape can be secured. Further, since the reinforcing conductive member 33 is smaller in size than the internal space 20, it can be smoothly inserted into and extracted from the internal space 20.

  The component includes a shaft portion 25 formed with a male screw, a flange portion 26 provided integrally with the shaft portion 25, and a welding projection 27 formed on a flange surface opposite to the shaft portion 25. It is a bolt 9.

  As described above, since the steel plate is securely sandwiched between the welding projection 27 and the pressure receiving member 37, the portion of the welding projection 27 and the steel plate are appropriately melted to obtain a normal welding state. In such a welded state, the flange portion 26 comes into close contact with the surface of the pipe member 21, or a slight gap exists between the flange portion 26 and the surface of the pipe member 21. Therefore, the welding strength of the projection bolt 9 can be sufficiently obtained.

  The steel plate part 8 is a pipe member 21 having a circular cross section.

  Normal welding can be obtained without deforming the circular cross-sectional shape by interposing the reinforcing conductive member 33.

  The steel plate component 8 is obtained by integrating a plurality of steel plate members 22, 23, 24.

  In the case of the steel plate part 8 in which the plurality of steel plate members 22, 23, 24 are integrated by spot welding or the like, the steel plate part 8 itself has a complicated shape, and the internal space 20 also has various shapes. However, according to the present embodiment, even in such an internal space 20, good energization and component pressurization are possible as described above.

  The invention of the welding method is to weld a part to the outer surface of a steel sheet part having an internal space by electric resistance welding, preventing deformation of the steel sheet part due to electrode pressurization, and causing the welding current to flow in the thickness direction of the steel sheet part. Inserting a reinforcing conductive member to be energized into the internal space, pressurizing the component with a movable electrode on the outer surface of the steel plate component facing the reinforcing conductive member, and energizing the welding current to weld the component to the outer surface of the steel plate component It is characterized by.

  The operational effects of the embodiment of the welding method are the same as the operational effects of the embodiment of the welding apparatus.

  FIG. 4 shows a second embodiment.

  In the second embodiment, the component in the above-described embodiment is changed to a projection nut 60. In the following description, the projection nut may be simply expressed as a nut. The structure of the reinforcing conductive member 33 shown in FIG. 4A is the same as that of the reinforcing conductive member 33 shown in FIG. And the steel plate component 8 is the bowl-shaped thing shown in FIG.7 (C). A pilot hole 62 is formed in the steel plate member 24, and a guide pin 61 provided in the pressure receiving member 37 passes therethrough. The nut 60 is skewed by the supply rod 63 and slides down, and is fitted to the protruding guide pin 61. Other configurations are the same as those of the first embodiment including the portions not shown, and members having the same functions are denoted by the same reference numerals. In addition, other functions and effects are the same as those of the first embodiment.

  FIG. 4B shows a case where the nut 60 is held on the movable electrode 6. A permanent magnet 64 is disposed inside the movable electrode 60, and the nut 60 is attracted and held in a holding recess 65 provided on the end face of the electrode. A positioning pin 65 is provided in the holding recess 66 for centering the nut 60. The rest of the configuration is the same as that of the embodiment shown in FIG. 4A including the parts not shown, and the same reference numerals are given to members having the same functions. In addition, other functions and effects are the same as those in the embodiment shown in FIG.

  As described above, according to the present invention, a welding current in the plate thickness direction is passed through the steel plate at the welding location, and abnormal deformation of the hollow steel plate part is prevented by pressurization of the electrode, so that the welding state has a high welding strength. Therefore, it can be used in a wide range of industrial fields such as automobile body welding processes and home appliance sheet metal welding processes.

It is sectional drawing which shows an eccentric cam type reinforcement conduction member. It is sectional drawing which shows a hydraulic cylinder type reinforcement conduction member. It is sectional drawing which shows a clearance provision type reinforcement conduction | electrical_connection member. It is sectional drawing which shows the case of projection nut welding. It is sectional drawing which shows another reinforcement conduction member. It is sectional drawing which shows a welding state. It is a perspective view which shows the kind of steel plate component. It is a side view which shows the whole welding machine.

Explanation of symbols

6 movable electrode 7 fixed electrode 8 steel plate part 9 projection bolt 10 receiving hole 20 internal space 21 pipe member 22 steel plate member 23 steel plate member 24 steel plate member 25 shaft portion 26 flange portion 27 welding projection 33 reinforcing conduction member 34 main body 37 pressure receiving member 47 Seating section 60 Projection nut S Clearance 100 Welding device 200 Parts supply unit

Claims (12)

  Parts are welded to the outer surface of a steel plate part having an internal space by electric resistance welding, the steel plate part is prevented from being deformed by electrode pressurization, and a welding current is passed in the thickness direction of the steel plate part and the internal space A hollow steel plate part is provided with a movable conducting member inserted into the outer surface of the steel plate part, and a movable electrode that pressurizes the part and applies a welding current to the outer surface of the steel sheet part facing the reinforcing conduction member. Welding equipment.   2. The welding apparatus for a hollow steel plate part according to claim 1, wherein a pressure receiving member that is in close contact with the inner surface of the internal space is provided on the reinforcing conductive member, and an expansion means is provided for bringing the pressure receiving member into close contact with the inner surface of the internal space. .   A pressure receiving member that is in close contact with the inner surface of the internal space is provided on the reinforcing conductive member, and a gap that disappears due to elastic deformation of the steel sheet due to pressurization of an electrode is provided between the pressure receiving member and the inner surface of the internal space. Item 2. A welding apparatus for hollow steel plate parts according to Item 1.   The component is a projection bolt having a shaft portion on which a male screw is formed, a flange portion provided integrally with the shaft portion, and a welding protrusion formed on a flange surface opposite to the shaft portion. The welding apparatus of the hollow steel plate components in any one of Claims 1-3.   The said steel plate part is a pipe member with a circular cross section, The welding apparatus of the hollow steel plate part in any one of Claims 1-4.   The said steel plate component integrates several steel plate members, The welding apparatus of the hollow steel plate component in any one of Claims 1-4.   A reinforcing conductive member for welding a part to the outer surface of a steel sheet part having an internal space by electric resistance welding, preventing deformation of the steel sheet part due to electrode pressurization, and passing a welding current in the thickness direction of the steel sheet part. A hollow steel plate which is inserted into the inner space and presses the component with a movable electrode on the outer surface of the steel plate component facing the reinforcing conducting member and energizes the welding current to weld the component to the outer surface of the steel plate component. How to weld parts.   The method for welding hollow steel plate parts according to claim 7, wherein the reinforcing conduction member is provided with a pressure receiving member that is in close contact with the inner surface of the internal space, and an expansion means is provided for bringing the pressure receiving member into close contact with the inner surface of the internal space. .   A pressure receiving member that is in close contact with the inner surface of the internal space is provided on the reinforcing conductive member, and a gap that disappears due to elastic deformation of the steel sheet due to pressurization of the movable electrode is provided between the pressure receiving member and the inner surface of the internal space. The method for welding hollow steel plate parts according to claim 7.   The component is a projection bolt having a shaft portion on which a male screw is formed, a flange portion provided integrally with the shaft portion, and a welding protrusion formed on a flange surface opposite to the shaft portion. The welding method of the hollow steel plate components in any one of Claims 7-9.   The method for welding a hollow steel plate part according to any one of claims 7 to 10, wherein the steel plate part is a pipe member having a circular cross section.   The method for welding hollow steel plate components according to any one of claims 7 to 10, wherein the steel plate components are obtained by integrating a plurality of steel plate members.

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