Welding apparatus and welding method

Abstract

A plurality of members are appropriately welded to each other. A welding device that welds a plurality of members to each other, wherein there are: a welding torch; an information acquisition unit that can acquire information of an area where the plurality of members are located as viewed from the welding torch side; a control unit that controls welding of the welding torch. The control unit has a start position decision section that decides a welding start position of the welding torch, which determines a center of gravity of the area where the plurality of members are located according to contour information of the area where the plurality of members are located, and decides the start position using the determined center of gravity.

Description

Technical Field

[0001] This invention relates to welding apparatus and welding methods. Background Technology

[0002] Patent document 1 discloses the following technology: using a 3D camera to acquire point group data of a welding reference surface, and then configuring a welding torch relative to a welding position determined based on the acquired point group data and performing welding.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2023-87928 Summary of the Invention

[0006] The determination of the welding position affects the welding quality. In the case of Patent Document 1, point group data is obtained to determine the welding position. Therefore, the processing of information obtained from the 3D camera and the processing of information required for determining the welding position are complex.

[0007] The technical problem that the invention aims to solve

[0008] When joining multiple components together by welding, it is desirable to be able to determine the welding positions more easily and to perform the welding appropriately.

[0009] Technical solutions for solving technical problems

[0010] One aspect of the present invention is a welding apparatus for welding multiple components together, wherein it comprises: Welding torch; An information acquisition unit is capable of acquiring information about the area where the plurality of components are located, as observed from the welding torch side; A control unit that controls the welding of the welding torch; The control unit has a start position determination unit that determines the welding start position of the welding torch. The start position determination unit determines the center of gravity of the region where the plurality of components are located based on the contour information of the region where the plurality of components are located, and uses the determined center of gravity to determine the start position.

[0011] One aspect of the present invention is a welding method that uses a welding torch to weld multiple components together, comprising the following steps: Obtain information about the area where the plurality of components are located, as observed from the side of the welding torch; The welding start position is determined based on the contour information of the area where the multiple components are located; The welding torch is moved to the starting position to weld the plurality of components together. In the step of determining the welding start position, the center of gravity of the region where the plurality of components are located is determined based on the contour information of the region where the plurality of components are located, and the determined center of gravity is used to determine the start position.

[0012] Invention Effects

[0013] According to one aspect of the invention, multiple components can be properly welded together. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the welding device.

[0015] Figure 2 This is a diagram illustrating the welding torch.

[0016] Figure 3 This is a schematic diagram illustrating the positional relationship between the terminals on the stator side and the terminals on the busbar side, which are the objects to be welded.

[0017] Figure 4 This diagram illustrates the configuration of the busbar-side terminals and the busbar-side terminals when the stator-side terminals and the busbar-side terminals are fused together.

[0018] Figure 5 This diagram illustrates the positional offset between the terminals on the stator side and the terminals on the busbar side.

[0019] Figure 6 This is a diagram illustrating the starting position of the welding process.

[0020] Figure 7 This is a schematic diagram illustrating the relationship between the welding start position and the molten ball formed during welding.

[0021] Figure 8 This is a schematic diagram illustrating the relationship between the welding start position and the molten ball formed during welding.

[0022] Figure 9 This is a schematic diagram illustrating the relationship between the welding start position and the molten ball formed during welding.

[0023] Figure 10 This is a diagram illustrating the configuration of a 3D camera.

[0024] Figure 11 It is a diagram illustrating images captured by a 3D camera.

[0025] Figure 12 It is a diagram that illustrates the determination of the contours of each pixel that makes up the captured image and the relationship between pixels and distance information.

[0026] Figure 13 This diagram illustrates the setting of the welding start position.

[0027] Figure 14 This diagram illustrates the setting of the welding start position.

[0028] Figure 15 This diagram illustrates the setting of the welding start position.

[0029] Figure 16 This diagram illustrates the setting of the welding start position.

[0030] Figure 17 This diagram illustrates the positional offset between the terminals on the stator side and the terminals on the busbar side.

[0031] Figure 18 This is a diagram illustrating the correction of the welding torch position.

[0032] Figure 19 This is a flowchart of the process for determining the welding start position.

[0033] Figure 20 This is a diagram illustrating the shape of the front end of the electrode rod.

[0034] Figure 21 This is a diagram illustrating a variation of setting the welding start position.

[0035] Figure 22 This diagram illustrates the setting of the welding start position when there are a total of 3 components.

[0036] Figure 23 This is a diagram illustrating a variation of the welding start position setting when there are a total of 3 components.

[0037] Figure 24 This diagram illustrates the setting of the welding start position when there are a total of 3 components.

[0038] Figure 25 This is a diagram illustrating a variation of the shape of a welded terminal assembly.

[0039] Figure 26 This is a diagram illustrating a variation of the shape of a welded terminal assembly.

[0040] Figure 27 This is a diagram illustrating a variation of the shape of a welded terminal assembly. Detailed Implementation

[0041] Hereinafter, the embodiment of the present invention will be described using welding apparatus 1, which is used to fuse (weld) the corresponding terminals Tb on the busbar side and the terminals Ts on the stator side.

[0042] Figure 1 This is a schematic structural diagram of welding device 1. Figure 2 This is a diagram illustrating welding torch 2.

[0043] like Figure 1 As shown, the welding device 1 includes a welding torch 2, a drive mechanism 3, a 3D camera 4, and a control device 5.

[0044] While the welding device 1 blows inert gas onto the welding part, it uses the welding torch 2 to perform TIG welding on the object to be welded.

[0045] like Figure 2 As shown, in the welding torch 2, the electrode rod 22 protrudes from the front end of the nozzle section 21. The front end side of the electrode rod 22 has a pointed shape that decreases in size as it moves towards the front end. The front end side of the electrode rod 22 is inclined at a predetermined angle θ relative to a straight line Za along the relative direction between the welding torch 2 and the object being welded (terminals Ts, Tb).

[0046] While releasing shielding gas from the tip of the nozzle 21, the welding torch 2 discharges an electric arc from the tip of the electrode rod 22. As a result, the workpiece is melted and welded. Here, as an example, the shielding gas is an inert gas such as argon. The shielding gas serves to transfer the energy of the plasma arc generated by the welding torch 2 (electrode rod 22) to the area to be welded and to prevent interference from atmospheric oxygen or oxygen in the weld area.

[0047] Based on instructions from the control device 5, the drive mechanism 3 positions the welding torch 2 at designated coordinates. These designated coordinates represent the initial position (welding start position Ps) of the welding torch 2 when welding the object being welded. For example, the drive mechanism 3 could be a multi-jointed robotic arm or orthogonal robot that holds the welding torch 2.

[0048] An orthogonal robot is an industrial robot consisting of three mutually orthogonal sliding axes. An orthogonal robot can also position the welding torch 2 at the welding start position Ps.

[0049] The 3D camera 4 is a conventionally known 3D camera that captures images of the object being welded and outputs image data capable of generating 3D images.

[0050] In this embodiment, the portion of the object to be welded (terminals Ts, Tb) opposite to the welding torch 2 is photographed from the straight line Za direction. Figure 2 (The upper end faces of terminals Ts and Tb). Straight line Za is a straight line along the direction relative to the welding object (terminals Ts and Tb) and welding torch 2.

[0051] In addition, the 3D camera 4 can also be attached to other multi-joint robotic arms and can be moved to designated coordinates.

[0052] The control device 5 is a control device for controlling the welding of the welding torch 2, the shooting of the 3D camera 4, and the processing of the images captured by the 3D camera 4.

[0053] In the control device 5, the processing unit 51, the storage unit 52, and the input / output port 53 are connected via a bus 50.

[0054] Input device 54 and output device 55 are connected to input / output port 53. Input device 54 is an interface that can give instructions to control device 5, such as a mouse, keyboard, touch panel, operator-held terminal, etc. Output device 55 is an interface that can output information, such as a monitor, speaker, operator-held terminal, etc.

[0055] Storage unit 52 is, for example, a recording medium capable of holding and rewriting information, such as an HDD, SSD, or memory.

[0056] The processing unit 51 is a processor such as a CPU or MPU, which executes the processing specified by the program based on the program stored in the storage unit 52.

[0057] The processing unit 51, as a functional block, includes a welding control unit 511 and a start position determination unit 512.

[0058] The welding control unit 511 controls the drive mechanism 3 to position the welding torch 2 at a specified coordinate. The welding control unit 511 positions the welding torch 2 at the welding start position Ps (specified coordinate) described later, and holds the welding torch 2 in the same position after welding begins and before welding is completed.

[0059] Furthermore, the welding control unit 511 controls the current and duration of the electrode rod 22, the amount of inert gas injected, etc., to perform TIG welding on the object to be welded.

[0060] The welding control unit 511 adjusts the current and duration of the electrode rod 22, the amount of inert gas injected, etc., according to the area of ​​the part (terminal Ts, Tb) opposite to the welding torch 2.

[0061] The start position determination unit 512 determines the initial position (welding start position) of the welding torch 2 when welding the object to be welded.

[0062] Here, we will describe the object to be welded by the welding apparatus 1 of this embodiment.

[0063] Figure 3 This is a schematic diagram illustrating the positional relationship between terminal Tb on the busbar 8 side and terminal Ts on the stator S side, which are the objects to be welded. Furthermore, in Figure 3 For ease of explanation, the illustration of the side (left side of the figure) of the busbar 8 placed in the housing HS, bounded by the diameter line Lz of the cylindrical housing HS, is omitted.

[0064] In this embodiment, the stator S-side terminal Ts and the busbar 8-side terminal Tb of the electric motor for vehicles are used as the objects to be welded together.

[0065] like Figure 3 As shown, the stator S of the electric motor M for vehicles has a cylindrical base S1 (stator core). The base S1 is fixed to the inner circumference of the cylindrical housing HS (peripheral wall portion 10).

[0066] The inner diameter side region S2 of the base S1 (in) Figure 3 The area (indicated by the crossed shading) is the region where windings, which act as electrical conductors, are installed. The windings are formed of a conductive metallic material, such as copper. In the electric motor M, the rotor R is arranged inside this region S2.

[0067] Viewed from the opening direction of the housing HS, at one end of the stator S ( Figure 3 The terminals Ts, which are connected to the busbar 8, are led out from the winding region S2 at the end of the paper near the front side. As an example, in this embodiment, a total of 24 terminals Ts are led out from the winding region S2. The led-out terminals Ts are divided into an inner diameter side and an outer diameter side, with 12 terminals on each side.

[0068] On the inner and outer diameter sides, two terminals are grouped (hereinafter also referred to as terminal groups) and arranged at predetermined intervals circumferentially around axis Z. Here, axis Z is a straight line concentric with the rotation axis of rotor R. Viewed from the opening direction of housing HS (stator S), axis Z is located at the center of stator S.

[0069] In the following description, the positional relationships of each component will be explained with reference to axis Z, as needed.

[0070] Viewed from the opening direction of the housing HS (stator S), the terminals Ts on the inner diameter side are located on the imaginary circle Im2 centered on the axis Z. The terminals Ts on the outer diameter side are located on the imaginary circle Im1 centered on the axis Z.

[0071] The terminals Ts on the inner diameter side and the terminals Ts on the outer diameter side are arranged in a phase-shifted manner around the axis Z in the circumferential direction.

[0072] In this embodiment, in order to connect each terminal Ts on the stator S side to the corresponding terminal Tb in the busbar 8, each terminal Ts on the stator S side is positioned on both the inner diameter side and the outer diameter side as follows: Figure 3 The positional relationship configuration is shown.

[0073] Busbar 8 is a component used to connect multiple terminals Ts on the stator S side to the power supply line on the inverter side (not shown).

[0074] Viewed from the front, the busbar 8 has a generally arc-shaped base 81. A contact support portion 82 is provided on the outer periphery 81a of the base 81. Multiple contact support portions 82 are provided at predetermined intervals along the length direction (left-right direction in the figure) of the base 81.

[0075] Terminals 82a for connection are exposed at the front end of the contact support portion 82. These terminals 82a are connected to the power supply line extending from the inverter (not shown).

[0076] Multiple terminal groups 83 and multiple terminal groups 84 are provided on the inner periphery 81b of the base 81. The terminal group 83 is composed of a pair of terminal pieces 831, 831. The terminal piece 831 is a columnar member that extends radially inward from the inner periphery 81b of the base 81.

[0077] Terminal groups 83 are provided at predetermined intervals along the length direction (left-right direction in the figure) of the base 81.

[0078] Terminal group 84 consists of a pair of terminal pieces 841, 841. Terminal piece 841 is a columnar member that extends radially inward from the inner periphery 81b of base 81.

[0079] Terminal groups 84 are provided at predetermined intervals along the length direction (left-right direction in the figure) of the base 81.

[0080] Terminal pieces 831 and 841 have a basic shape with their front ends bent. The front ends of terminal pieces 831 and 841 are bent in the same direction (near the front of the paper). The bent front ends of terminal pieces 831 and 841 become terminals Tb and Tb connected to terminals Ts on the stator S side.

[0081] In the base 81, the terminal Tb on the terminal group 84 side is located on the inner diameter side of the terminal Tb on the terminal group 83 side.

[0082] Here, the terminal pieces 831 and 841 constituting the terminal groups 83 and 84 are components made of a conductive metal material such as copper. The base ends of the terminal pieces 831 and 841 are embedded inside the base 81 and are respectively connected to the corresponding terminals 82a of the contact support portion 82 described above. By connecting the terminal Ts on the stator S side to the terminal Tb on the busbar 8 side, the terminal Ts on the stator S side is connected to the power supply line extending from the inverter (not shown) via the busbar 8.

[0083] Figure 4 This diagram illustrates the arrangement of terminals Ts and Tb when the stator S-side terminal Ts and the busbar 8-side terminal Tb are fused together. Additionally, in Figure 4 The diagram illustrates the direction along... Figure 3 The cross section of line AA in the diagram. Figure 5This diagram illustrates the positional offset between terminal Ts on the S side of the stator and terminal Tb on the 8 side of the busbar.

[0084] When welding the terminals Ts on the stator S side and the terminals Tb on the busbar 8 side, as an example, the terminals Tb on the busbar 8 side are positioned through the following steps: (I) The housing HS containing the stator S is arranged with its opening facing upwards (Z direction). Next, (II) the end side of the winding leading from the winding region S2 is bent, and the terminals Ts on the winding side are positioned at the engagement position with the terminals Tb on the busbar 8 side. Then, (III) the busbar 8 is placed on the upper end of the housing HS, and each terminal Tb on the busbar 8 side is positioned at the engagement position with the corresponding terminal Ts on the stator S side (see reference). Figure 3 , Figure 4 ).

[0085] Here, the terminals Ts on the outer diameter side of the stator S are further bent circumferentially after the end side of the winding leading from the winding region S2 is bent further outward than the winding region S2, and arranged in a manner where the terminal groups are arranged at approximately equal intervals in the circumferential direction. Figure 3 The location shown.

[0086] Similarly, the inner diameter side terminals Ts cause the end side of the winding leading from the winding region S2 to be bent in such a way that the terminal groups are arranged at approximately equal intervals in the circumferential direction, and are configured in... Figure 3 The location shown.

[0087] Therefore, bending stress acts on the terminals Ts on the inner diameter side and the terminals Ts on the outer diameter side. When assembling the busbar 8, there is a deviation in the relative positional relationship between each terminal Ts and the terminal Tb on the side of the busbar 8.

[0088] like Figure 4 As shown, during fusion bonding, it is preferable that the terminal Ts on the stator S side and the terminal Tb on the busbar 8 side are parallel to each other and in contact without gap. However, the terminal Ts on the stator S side and the terminal Tb on the busbar 8 side are sometimes tilted and spaced apart due to the aforementioned bending stress (see reference). Figure 5 ).

[0089] Therefore, in this embodiment, in order to make the terminal Ts on the stator S side and the terminal Tb on the busbar 8 side more closely positioned, a pair of clamping tools 9, 9 (see reference) are used. Figure 2 A pair of clamping tools 9, 9 are located in the opposite direction of terminals Ts and Tb. Figure 2 Force is applied to terminals Tb and Ts from both sides (left and right directions) in a direction that brings them closer together.

[0090] Here, we will explain the soldering start position Ps (soldering start point) when soldering terminals Ts and Tb to each other.

[0091] Figure 6 This is a diagram illustrating the welding start position Ps. Figure 6 In the middle, it is schematically indicated that from Figure 4 Observe the status of terminal Ts on the stator S side and terminal Tb on the busbar 8 side in the AA direction of view. Figures 7 to 9 This is a schematic diagram illustrating the relationship between the welding start position Ps and the molten ball C formed during welding. Figure 7 The diagram illustrates the formation process of the molten ball C when the welding start position Ps is set at the boundary line L1 between terminals Ts and Tb. Figure 8 The diagram illustrates the formation process of the molten ball C when the welding start position Ps is set on the terminal Tb side. Figure 9 The diagram illustrates the formation process of the molten sphere C when the welding start position Ps is set at a position where the molten sphere C forms in an ideal shape.

[0092] like Figure 6 As shown, in this embodiment, the terminal Ts on the stator S side and the terminal Tb on the busbar 8 side have different shapes when viewed from the welding torch 2 side.

[0093] Specifically, terminal Tb is approximately square, while terminal Ts is rectangular. Furthermore, the mating directions of terminals Tb and Ts are... Figure 6 The thicknesses Wb1 and Ws1 in the left-right direction (X direction) and the orthogonal direction of the joint direction ( Figure 6 The thicknesses Wb2 and Ws2 in the vertical direction (Y direction) are different.

[0094] Here, as Figure 7 As shown, when welding terminals Tb and Ts together, an electric arc discharge is performed from the welding torch 2 toward the upper ends of terminals Tb and Ts. This melts the base material on the upper side of terminals Tb and Ts, causing the materials to mix and form a molten sphere C. The molten sphere C then solidifies, connecting terminals Tb and Ts together.

[0095] Typically, when welding two components with the same cross-sectional area as viewed from the welding torch 2 side, the welding start position Ps is set on the boundary line of the two components in the joint direction, at a position that is approximately the center of the width direction (orthogonal direction of the joint direction) of the two components.

[0096] This is because the boundary line between the two components is visually recognizable when viewed from the two sides of the welding torch, making it easy to determine their position.

[0097] However, in this embodiment, the thicknesses Wb1 and Ws1 of terminals Tb and Ts are different in the bonding direction. Therefore, if the bonding directions of terminals Tb and Ts ( Figure 6If the welding start position Ps is set on the boundary line L1 in the left-right direction (X direction), the heating of the terminal Tb side during welding becomes insufficient, and the resulting molten ball C deviates (refer to...). Figure 7 ).

[0098] Therefore, when the welding start position Ps is directed towards the thick terminal Tb side ( Figure 6 When the welding starts (on the left side) moves, the heating range r centered on the starting position Ps moves towards the terminal Tb. As a result, the amount of base material melted at terminal Tb increases, and the deviation of the molten ball C generated during welding decreases. However, if the welding starting position Ps is too far away from terminal Ts, the deviation of the molten ball C on the terminal Tb side increases (refer to...). Figure 8 ).exist Figure 8 The text indicates that the welding start position has moved to... Figure 6 The state of the molten sphere C at the position indicated by the reference numeral Ps' in the attached figure.

[0099] Similarly, the orthogonal directions of the mating directions of terminals Tb and Ts ( Figure 6 The thicknesses Wb2 and Ws2 in the vertical direction (Y direction) are different. Therefore, if the thicknesses in the orthogonal directions of the bonding directions of terminals Tb and Ts are different... Figure 6 If the welding start position Ps is simply set on the center line C1 of the terminal Tb in the up and down direction, the molten ball C generated during welding may deviate.

[0100] Here, the molten ball C is preferably formed equally across both sides of the welded components (terminals Tb, Ts) (see reference). Figure 9 Therefore, it is preferable to heat the welded components (terminals Tb, Ts) approximately equally.

[0101] The areas of terminals Tb and Ts differ from their shapes when viewed from the welding torch side 2. That is, in this embodiment, terminals Tb and Ts with different shapes and areas are welded together. Therefore, simply moving the welding start position Ps in the joining direction (X direction) may not result in the proper formation of a molten ball C across terminals Tb and Ts.

[0102] Therefore, in this embodiment, the welding start position Ps is determined by considering the area and positional relationship of each terminal Tb and Ts region when viewed from the welding torch 2 side.

[0103] Specifically, the welding start position Ps is determined by using the center of gravity of the regions of terminals Tb and Ts when viewed from the two sides of the welding torch.

[0104] Here, we explain the determination of the welding start position Ps using the center of gravity.

[0105] Figure 10 This is a diagram illustrating the configuration of the 3D camera 4.

[0106] Figure 11 This is a diagram illustrating the images captured by the 3D camera 4.

[0107] Figure 12 It is a diagram that illustrates the determination of the contours of each pixel that makes up the captured image and the relationship between pixels and distance information.

[0108] Figure 13 This is a diagram illustrating the setting of the area enclosed by the contour and the welding start position Ps.

[0109] like Figure 10 As shown, in this embodiment, at the moment before the welding of terminals Tb and Ts begins, the 3D camera 4 captures the portion of terminals Tb and Ts that is opposite to the welding torch 2.

[0110] Specifically, with the welding torch 2 positioned away from the terminals Tb and Ts, the 3D camera 4 is positioned above the terminals Tb and Ts to capture images of the area where the terminals Tb and Ts are located, as viewed from the side of the welding torch 2.

[0111] Therefore, as Figure 11 As shown, a planar image of the upper end (opposite to the welding torch 2) of terminals Tb and Ts is obtained.

[0112] The starting position determination unit 512 of the welding apparatus 1 performs conventional image processing (e.g., image processing using an edge filter) to extract the contours of the terminal Tb and Ts regions.

[0113] Specifically, the starting position determination unit 512 determines the pixel Px_b located on the contour of terminal Tb and the pixel Px_s located on the contour of terminal Ts, which are among the pixels Px constituting the captured image. Then, the determined set of pixels is extracted as the contour lines Lnb and Lns of terminals Tb and Ts. Information indicating which pixel among the pixels constituting the captured image corresponds to the contour lines Lnb and Lns is equivalent to contour information.

[0114] exist Figure 12 In the case of the partial magnification example, the region of pixel Px_b corresponding to the outline of terminal Tb, the region of pixel Px_s corresponding to the outline of terminal Ts, and the region where they overlap are shown.

[0115] By extracting the pixels corresponding to the contour, such as Figure 12 As shown, the contour lines Lnb and Lns of the specified range of terminal Tb and terminal Ts are extracted in such a way that they have partially overlapping ranges.

[0116] exist Figure 12 In this case, one side of the outline Lnb of terminal Tb completely overlaps with the outline Lns of terminal Ts. That is, there is a region where the area surrounded by the outline Lnb of terminal Tb and the area surrounded by the outline Lns of terminal Ts are adjacent.

[0117] Therefore, the area enclosed by the outline Lnb of terminal Tb and the area enclosed by the outline Lns of terminal Ts can be considered as a single region.

[0118] In this case, the starting position determination unit 512 of the welding device 1 will determine the starting position by passing through the outermost periphery of the region surrounded by the outline line Lnb of terminal Tb and the region surrounded by the outline line Lns of terminal Ts (refer to...). Figure 13 The outline of the area to be welded (terminals Tb, Ts) is determined.

[0119] When a region enclosed by the contour line Ln is determined, the starting position determination unit 512 calculates the centroid G of the region enclosed by the contour line Ln. Then, the calculated centroid G is determined as the welding start position Ps. The centroid G is the centroid when the regions of terminal Tb and terminal Ts are considered as a concentrated region. If welding is performed with the centroid G as the starting position Ps, the welding heat diffuses outward from the centroid G.

[0120] Thus, at the upper ends of terminals Tb and Ts, heat diffuses approximately evenly, forming molten spheres C where the base material melts approximately evenly, and terminals Tb and Ts are then appropriately welded.

[0121] That is, even when welding terminals Ts and Tb, which have different shapes (areas) from the opposite part of the welding torch 2, to each other, the difference in shape (area) is taken into account to determine the welding start position Ps, so that terminals Tb and Ts can be welded appropriately. In addition, as an example, the center of gravity is the area center of gravity.

[0122] Here, in Figure 13 The example illustrates an ideal engagement state where one side of the engagement surface of terminal Tb engages with one side of the engagement surface of terminal Ts across the entire surface.

[0123] Considering the melting of the base material during welding, clamping tools 9 and 9 abut against terminals Tb and Ts at positions offset from their upper ends during welding.

[0124] Therefore, the positional constraints on the upper side of terminals Tb and Ts become loose, and the state before welding may not be an ideal joint state.

[0125] In this embodiment, when the region surrounded by contour line Lnb and the region surrounded by contour line Lns can be regarded as (A) a region surrounded by a contour line, the center of gravity of the region surrounded by the contour line is used to set the welding start position Ps.

[0126] Here, (A) can be considered as a region surrounded by a contour line, not only when the region surrounded by contour line Lnb is adjacent to the region surrounded by contour line Lns in a state of complete contact.

[0127] For example, even if there is a gap or positional offset between the area surrounded by the contour line Lnb and the area surrounded by the contour line Lns, the gap or positional offset between the terminal Ts and the terminal Tb is equivalent to the above (A) if it is a gap or positional offset that does not hinder welding.

[0128] Here, a gap that does not hinder welding refers to a gap between terminals Ts and Tb that is sufficient to prevent the inflow of molten balls C generated by the melting of the base material. A gap that creates an obstacle refers to a gap between terminals Ts and Tb that is too wide to prevent the inflow of molten balls C generated by the melting of the base material.

[0129] If the gap is wide, the molten ball C cannot remain at the ends of terminals Ts and Tb, and the molten ball C generated by the melting of the base material flows into the gap. In this case, welding of terminals Ts and Tb is hindered.

[0130] Furthermore, the positional offset that does not hinder welding refers to the degree of positional offset formed by the molten ball C generated by the melting of the base material across terminals Ts and Tb. Therefore, when the generated molten ball C is formed at the end of one terminal Ts or Tb, or when it is unevenly distributed between terminals Ts and Tb, it becomes a positional offset that hinders welding.

[0131] Here, the size and positional offset of the gap used in determining whether there is an obstacle or not are determined based on the surface tension, fluidity, viscosity, etc. of the molten base material. In this embodiment, the size (threshold) of the gap used in determining whether there is an obstacle or not is a value obtained through experiments and simulations.

[0132] Figures 14 to 16 This is a diagram illustrating an example of setting the welding start position Ps based on the area enclosed by the contour lines Lnb and Lns.

[0133] Figure 17 This diagram illustrates the positional offset between terminal Ts on the S side of the stator and terminal Tb on the 8 side of the busbar. Figure 18 This is a diagram illustrating the correction of the position of welding torch 2.

[0134] Here, in Figures 14 to 16 The text represents an example of a situation where the regions enclosed by contour line Lnb and Lns can be considered as (A) a region enclosed by a single contour line.

[0135] Here, the case where the area enclosed by the contour line Lnb and the area enclosed by the contour line Lns can be regarded as a single area enclosed by a single contour line is synonymous with the case where multiple components are viewed as a single component when viewed from the welding torch 2 side.

[0136] like Figure 14 As shown, when the contour lines Lnb and Lns are offset in the Y direction and have a partial overlap, the relationship described above (A) is obtained.

[0137] In this case, the start position determination unit 512 determines the maximum contour line Ln that connects the outermost periphery of the area surrounded by contour lines Lnb and Lns, and determines the centroid G of the area surrounded by the determined maximum contour line Ln as the welding start position Ps.

[0138] like Figure 15 As shown, when contour lines Lnb and Lns are in contact on one side in the Y direction, but the other side in the Y direction is offset in the X direction, the distance d at the point where the separation distance between contour lines Lnb and Lns in the X direction is the largest is calculated and compared with the threshold Tha. Then, if the distance d is less than or equal to the threshold Tha (Tha≥d), it is considered to be the relationship described in (A) above.

[0139] In this case, the start position determination unit 512 determines the maximum contour line Ln that connects the outermost periphery of the area surrounded by contour lines Lnb and Lns, and determines the centroid G of the area surrounded by the determined maximum contour line Ln as the welding start position Ps.

[0140] In this case, for example, in the part where the contour line Lnb and the contour line Lns are separated by a gap, the angle P1 of the contour line Lnb and the angle P2 of the contour line Lns are connected with the shortest distance, and the area of ​​the region surrounded by the largest contour line Ln is set to be the largest.

[0141] like Figure 16 As shown, when contour lines Lnb and Lns are separated without having a tangent point, the distance d at the point where the separation distance in the X direction between contour lines Lnb and Lns is the largest is calculated and compared with the threshold Tha. Then, if the distance d is less than or equal to the threshold Tha (Tha≥d), it is considered to be the relationship described in (A) above.

[0142] In this case, the start position determination unit 512 determines the maximum contour line Ln that connects the outermost periphery of the area surrounded by contour lines Lnb and Lns, and determines the centroid G of the area surrounded by the determined maximum contour line Ln as the welding start position Ps.

[0143] In this case, for example, in the part where the contour line Lnb and the contour line Lns are separated by a gap, the angles P1 and P4 of the contour line Lnb and the angles P2 and P3 of the contour line Lns are connected by the shortest distance, and the area of ​​the region enclosed by the largest contour line Ln is set to be the largest.

[0144] Here, if the distance d is greater than the threshold Tha (Tha < d = ), it is determined that proper welding of the terminals to each other is not possible based on the current configuration of terminals Tb and Ts. This is because the area enclosed by the contour line Lnb is too wide to be properly welded to the area enclosed by the contour line Lns, causing the generated molten sphere C to fall into the gap.

[0145] In this case, the area enclosed by contour line Lnb and the area enclosed by contour line Lns cannot be considered as a single concentrated area. That is, the distance d exceeds the threshold at which terminals Tb and Ts can be considered as a single component. In this case, an alarm sound is output from output device 55, and the welding device 1 is stopped automatically or upon waiting for an instruction input from input device 54.

[0146] As mentioned above, the relative positional relationship between terminals Tb and Ts may shift not only in the X and Y directions but also in the Z direction. Therefore, even when obtaining... Figure 11 In the case of the captured image shown, such as Figure 17 As shown, there are also cases where terminals Tb and Ts are configured with a Z-direction position offset.

[0147] Therefore, the starting position determination unit 512 calculates the distance Dz in the Z direction between the region enclosed by the contour line Lnb and the region enclosed by the contour line Lns.

[0148] As described above, the processed image obtained by processing the captured image (refer to...) Figure 12 For each pixel that makes up the image, there is distance information that can determine the distance to the 3D camera 4.

[0149] Therefore, in processing images ( Figure 12 In the paper, by referring to the distance information of each pixel, the deviation (separation distance Dz) between the region surrounded by the contour line Lnb and the region surrounded by the contour line Lns in the forward depth direction of the paper can be determined.

[0150] Here, as an example, the interval distance Dz is calculated using the following method: (a) Calculate the difference between the average distance to each pixel contained in the region enclosed by the contour line Lnb and the average distance to each pixel contained in the region enclosed by the contour line Lns, and set the calculated difference as the interval distance Dz. (b) Extract the combination with the largest separation distance from the combination of pixels contained in the region enclosed by the contour line Lns and pixels contained in the region enclosed by the contour line Lnb, and set the Z-direction distance between the pixels in the extracted combination as the separation distance Dz.

[0151] The start position determination unit 512 compares the calculated interval distance Dz with the threshold Th_z. If the calculated interval distance Dz is greater than the threshold Th_z (Dz > Th_z), the start position determination unit 512 does not determine the welding start position Ps. This is because if the separation distance between terminal Tb and terminal Ts is too large, welding may not be able to be performed properly.

[0152] In this embodiment, even if the above (A) is met, the welding start position Ps is not determined when the interval distance Dz is greater than the threshold Th_z.

[0153] Furthermore, if the calculated separation distance Dz is below the threshold Th_z (Dz≤Th_z), the welding start position Ps is determined and welding is performed.

[0154] Thus, when welding terminals Ts and Tb, which have different shapes (areas) from the opposite part of the welding torch 2, even if there is a positional offset between terminals Ts and Tb, the welding start position Ps is determined by taking into account the difference in shape (area) and positional offset, provided that welding is possible.

[0155] Therefore, terminals Ts and Tb can be soldered more appropriately.

[0156] Here, when welding torch 2 is positioned at the starting position Ps for welding, welding torch 2 is set at a position where it is at a height ha away from terminals Tb and Ts (see reference). Figure 18 ).

[0157] However, depending on the degree of positional offset of terminals Tb and Ts in the Z direction, there are cases where the initial position Ps is configured too close to terminals Tb and Ts, or too far away from terminals Tb and Ts. In these cases, the melting amount of terminals Tb and Ts may sometimes deviate.

[0158] Here, as an example, when the calculated Dz is equal to or greater than the threshold Th_z1 and equal to or less than the threshold Th_z (Th_z1≤Dz≤Thz), the starting position determination unit 512 can correct the position of the starting position Ps in the Z direction according to the interval distance Dz.

[0159] like Figure 18 As shown, when the welding start position Ps is set above the terminal Tb, the start position Ps is configured at an initial position that is a height ha away from the terminal Tb.

[0160] Here, when the terminal Tb is positioned with its height hb offset upwards from a predetermined position, the position of the welding torch 2 is offset upwards from its initial position by the height hb, and the separation distance between the welding torch 2 (electrode rod 22) and the terminal Tb is adjusted to a predetermined height ha (refer to...). Figure 18 (The image in the upper right corner).

[0161] Furthermore, when the terminal Tb is positioned with its height hb offset downwards from a predetermined position, the position of the welding torch 2 is offset downwards from its initial position by the height hb, and the separation distance between the welding torch 2 (electrode rod 22) and the terminal Tb is adjusted to a predetermined height ha (refer to...). Figure 18 (The image at the bottom right).

[0162] Therefore, it is possible to properly prevent the welding of terminals Ts and Tb from being hindered due to the different melting amounts of terminals Tb and Ts during welding caused by the positional offset of terminal Tb in the Z direction.

[0163] Figure 19 This is a flowchart of the basic process for determining the welding start position Ps.

[0164] When the terminals Ts and Tb to be welded together are held by clamping tools 9 and 9, and the welding preparation using welding torch 2 is completed (step S101, yes), the 3D camera 4 takes a picture (step S102).

[0165] Specifically, a 3D camera 4 positioned above terminals Tb and Ts captures images of the portion of terminals Tb and Ts that is opposite to the welding torch 2. The captured image is then input to the processing unit 51 of the welding apparatus 1 (see reference). Figure 11 ).

[0166] In the starting position determination unit 512 of the processing unit 51, the outline of the region (multiple components to be soldered) of the terminals Tb and Ts is extracted by processing the input captured image (step S103).

[0167] Therefore, the contour line Lnb of the region surrounding terminal Tb and the contour line Lns of the region surrounding terminal Ts are extracted (refer to...). Figure 12 , Figure 14 , Figure 15 , Figure 16 ).

[0168] Next, the starting position determination unit 512 calculates the distance Dz in the Z direction between the region enclosed by the contour line Lnb and the region enclosed by the contour line Lns (step S104).

[0169] If the calculated interval distance Dz is greater than the threshold Th_z (Dz > Th_z) (step S105, No), the start position determination unit 512 moves to step S106 and performs error handling. This is because, in this case, the separation distance Dz between terminal Tb and terminal Ts is too large, and soldering may not be performed properly. In error handling, for example, the output device 55 outputs a message indicating that soldering may not be performed properly (error notification).

[0170] Therefore, the welding device 1 stops automatically or upon receiving an instruction from the input device 54.

[0171] If the calculated interval distance Dz is below the threshold Th_z (Dz≤Th_z) (step S105, yes), the starting position determination unit 512 confirms whether the region surrounded by the contour line Lnb and the region surrounded by the contour line Lns can be captured as a concentrated region (S107).

[0172] If it is possible to capture a concentrated area (step S107, yes), the outermost contour line Ln, which is surrounded by contour lines Lnb and Lns, is determined as the contour line of the area of ​​the specified welding object (terminal Tb, Ts).

[0173] When a region enclosed by the contour line Ln is determined, the start position determination unit 512 determines the center of gravity G of the region enclosed by the contour line Ln as the welding start position Ps (step S108).

[0174] On the other hand, if a concentrated area cannot be captured (step S107, no), the process moves to step S106 and performs error handling (error notification).

[0175] Thus, when welding terminals Ts and Tb, which have different shapes (areas) from the opposite part of the welding torch 2, even if there is a positional offset between terminals Ts and Tb, the welding start position Ps is determined by taking into account the difference in shape (area) and positional offset, provided that welding is possible.

[0176] Therefore, terminals Ts and Tb can be soldered more appropriately.

[0177] Figure 20 This is a diagram illustrating the shape of the front end side of electrode rod 22.

[0178] In the above embodiment, an example is given where the front end of the electrode rod 22 of the welding torch 2 has a pointed shape that is inclined at a predetermined angle θ relative to the straight line Za.

[0179] The angle (θ) of the electrode rod 22 relative to the straight line Za can also be changed according to the area of ​​the terminals Tb and Ts that are the objects to be welded.

[0180] Here, when the angle θ between the tip of the welding torch 2 (electrode rod 22) and the straight line Za (vertical line) along the relative directions of the welding torch 2 and the terminals Tb and Ts is small, the current moving from the tip of the welding torch 2 toward the base material diffuses. In this case, the area for current transmission increases, resulting in the ability to melt and join the terminals Tb and Ts even when there are gaps between them or when there is some positional misalignment between them. That is, the robustness of the weld is improved.

[0181] On the other hand, when the angle θ between the tip of the welding torch 2 and the straight line Z2 is large, the current moving from the tip of the welding torch 2 toward the base material is concentrated within a limited area. In this case, the narrowing of the current transmission area results in a local concentration of energy at the terminals Ts and Tb (increased energy density). Therefore, if there is a gap between the terminals Ts and Tb, or if there is a positional misalignment between the terminals Ts and Tb, the welding may be insufficient.

[0182] Therefore, by taking into account the possible gaps between terminals Ts and Tb and the positional offsets between terminals Ts and Tb, the angle θ of the front end of the welding torch 2 (electrode rod 22) can be set so that even if there are some gaps or positional offsets between terminals Ts and Tb, terminals Ts and Tb can be properly welded to each other.

[0183] Here, as Figure 20 As shown, when the angle θ decreases to θ', the diameter W of the area reached by the current (arc) emitted from the electrode rod 22 expands to W'.

[0184] Therefore, when the area of ​​the part opposite to the welding torch 2 of the object to be welded (terminals Tb, Ts) is small, by increasing the angle θ, the current can be concentrated on the necessary part of the object to be welded (terminals Tb, Ts), and the welding time can be shortened.

[0185] Furthermore, when the area of ​​the part of the object to be welded (terminals Tb, Ts) opposite to the welding torch 2 is large, by reducing the angle θ to expand the arc's reach area, the object to be welded (terminals Tb, Ts) can be melted approximately uniformly. This effectively prevents incomplete welding.

[0186] In the above embodiment, an example is shown where the area of ​​a group of terminals (terminals Ts, Tb) that are soldered together is photographed in step S102. Multiple groups of terminals can also be photographed simultaneously.

[0187] For example, in Figure 3 The area surrounded by the thin line contains four sets of terminals (Ts, Ts) that are soldered together, and this area can also be used as the shooting range. Alternatively, all terminal sets can be shot simultaneously.

[0188] In particular, when the terminal Ts on the side of the electric motor M for vehicles is connected to the terminal Tb on the side of the busbar 8, the fewer times the terminal groups that are soldered together are photographed, the shorter the processing time can be, and thus a reduction in the manufacturing cost of the electric motor M can be expected.

[0189] In the above embodiment, an example of taking pictures using a 3D camera 4 is illustrated. Alternatively, two cameras can be used to photograph the opposing portions of terminals Tb and Ts that are opposite to the welding torch 2, and a conventionally known stereoscopic-based three-dimensional measurement method can be used to generate a processed image with distance information from the obtained images.

[0190] Alternatively, a LiDAR sensor can be used instead of a 3D camera to obtain processed images with distance information.

[0191] Figure 21 This is a diagram illustrating a variation of the case where the welding start position Ps is set based on the area enclosed by contour lines Lnb and Lns.

[0192] In the above embodiment, when the region surrounded by contour line Lnb and the region surrounded by contour line Lns can be regarded as a region surrounded by a single contour line, the center of gravity of the region surrounded by a single contour line is set as the welding start position Ps.

[0193] Specifically, if the distance d at the point where the separation distance between the region enclosed by contour line Lnb and the region enclosed by contour line Lns is the largest is less than the threshold Tha (Tha≥d), the region enclosed by contour line Lnb and the region enclosed by contour line Lns are considered as a region enclosed by a single contour line.

[0194] Here, when the distance d is the size at which the molten ball C can stay at the ends of terminals Ts and Tb, i.e., when the distance d is below the threshold Tha, the welding start position Ps can also be determined as follows.

[0195] like Figure 21As shown, when contour lines Lnb and Lns are separated without a tangent point, the distance d at the point where the separation distance in the X direction between contour lines Lnb and Lns is the largest is calculated and compared with a threshold Tha. Then, if the distance d is less than the threshold Tha (Tha≥d), the start position determination unit 512 determines the centroid G of contour line Lnb and the centroid G of the region enclosed by contour line Lns. Then, the midpoint of the straight line Lg connecting the determined centroids G and G is determined as the welding start position Ps.

[0196] With this configuration, even if there is some gap or positional misalignment between terminals Ts and Tb, terminals Ts and Tb can be properly soldered to each other.

[0197] In the above embodiment, an example is given of multiple components welded together as a pair of terminals Ts and Tb. The number of components can also be three or more.

[0198] Figures 22 to 24 This diagram illustrates the determination of the welding start position Ps when there are a total of 3 components.

[0199] As the total number of components increases, the outlines (Ln_TG1, Ln_TG2, Ln_TG3) of each component (TG1, TG2, TG3) are determined. Furthermore, if the area enclosed by the outlines (Ln_TG1, Ln_TG2, Ln_TG3) can be considered as (A) a region enclosed by a single outline Ln, the centroid G of the region enclosed by a single outline Ln is set as the welding start position Ps (refer to...). Figure 22 ).

[0200] The region enclosed by the contour lines (Ln_TG1, Ln_TG2, Ln_TG3) can be considered as a region enclosed by two contour lines. Furthermore, if the separation distance between the regions within the two contour lines Ln and Ln is a distance that does not hinder welding, the centroid G of the region enclosed by contour line Ln and the centroid G of the region enclosed by contour line Ln are determined. Then, the midpoint of the line segment connecting the determined centroids G and G is determined as the welding start position Ps (refer to...). Figure 23 ).

[0201] If the area enclosed by the contour lines (Ln_TG1, Ln_TG2, Ln_TG3) is considered as a different area enclosed by the three contour lines, welding will not be performed (see [reference]). Figure 24 ).

[0202] In this way, even when three components (TG1, TG2, TG3) are welded together, the center of gravity is determined based on the contour information of the area where the three components (TG1, TG2, TG3) are located in the captured image, and the determined center of gravity is used to determine the welding start position Ps. Thus, the three components (TG1, TG2, TG3) that are welded together can be welded appropriately.

[0203] Figures 25 to 27 This is a diagram illustrating a variation of the shape of the terminal assembly being welded.

[0204] In the above embodiment, an example is shown where a generally square terminal Tb and a generally rectangular terminal Ts are welded. The shape of the terminals is not limited to the shapes described above.

[0205] like Figure 25 As shown, the terminals Tb1 and Ts1 can also be thin in the bonding direction (X direction). In this case, by increasing the crossing angle (angle θ) of the electrode rod 22 relative to the straight line Za, or by reducing the current value to reduce the heat input energy, the terminals Tb1 and Ts1 can be properly welded to each other.

[0206] It should be noted that if the welding range is reduced by increasing the angle θ or decreasing the current value to reduce the heat input energy, it may result in only a part of the contact surface being welded, resulting in insufficient strength.

[0207] In this case, a new welding position can also be set in the area of ​​the terminals (terminals Ts, Tb) at a position different from the position of the center of gravity, and the position around the center of gravity can be welded.

[0208] For example, in Figure 25 Alternatively, an arc discharge can be performed at a position different from the welding start position Ps to perform a new weld on the part that is different from the welding start position Ps, thereby ensuring the weld strength of the terminals (terminals Ts, Tb) that are welded to each other.

[0209] In addition, such as Figure 26 As shown, the terminals Tb2 and Ts2 can also have significantly different widths in the Y direction. In this case, by reducing the angle θ of the electrode rod 22 relative to the straight line Za, or by increasing the current value to increase the heat input energy, the heating range can be expanded, and the terminals Tb2 and Ts2 can be properly welded together.

[0210] In addition, such as Figure 27 As shown, a recess Re can also be provided on one terminal Tb3, allowing at least a portion of another terminal Ts to be inserted. In this case, terminals Tb3 and Ts3 can also be properly soldered to each other.

[0211] As described above, the welding apparatus 1 of one aspect of the present invention has the following structure.

[0212] (1) Welding device 1 is a welding device for welding terminals Ts and Tb to each other (multiple components to each other).

[0213] Welding device 1 has welding torch 2, A 3D camera 4 (information acquisition unit) capable of acquiring information about the areas where terminals Ts and Tb are located, as observed from both sides of the welding torch. And the control device 5 (control unit) for controlling the welding of the welding torch 2.

[0214] The control device 5 has a start position determination unit 512 that determines the welding start position Ps of the welding torch 2.

[0215] The starting position determination unit 512 determines the center of gravity of the area where terminals Ts and Tb are located based on the contour information of the area where terminals Ts and Tb are located, and uses the determined center of gravity to determine the starting position.

[0216] According to one aspect of the invention, the welding start position Ps is determined using the centroid G of the terminals Ts and Tb (the areas where multiple components are located). Compared to simply setting the start position Ps on the boundary lines between the terminals Ts and Tb, the displacement of the molten ball C caused by the melting of the base material of the terminals Ts and Tb during welding can be suppressed, thus enabling proper welding of the terminals Ts and Tb.

[0217] (2) In (1) above, when the starting position determination unit 512 can identify the area where the terminals Ts and Tb (multiple components) are located as an area surrounded by a contour line Ln based on the contour information, it determines the center of gravity G of the area surrounded by the contour line Ln and determines the determined center of gravity as the starting position Ps.

[0218] According to one aspect of the invention, even if there are gaps between the regions of terminals Ts and Tb (multiple components) defined by contour lines Lns and Lnb, if the gaps are to the extent that the molten ball C does not flow in, the region surrounded by contour lines Lns and Lnb is identified as the region surrounded by a single contour line Ln.

[0219] Thus, by determining the starting position Ps as the centroid G of the region surrounded by a contour line Ln, the molten sphere C generated during welding due to the melting of the base material of terminals Ts and Tb (each component) is generated across multiple components with the centroid G as the center.

[0220] Therefore, the molten base materials of terminals Ts and Tb are partially mixed and solidified in the molten sphere C. As a result, in the area where terminals Ts and Tb (multiple components) are welded, the components are mixed with each other, which reduces the possibility of poor bonding caused by insufficient mixing of the components.

[0221] Here, if the welding start position Ps deviates from the center of gravity, the position of the molten sphere C generated during welding due to the melting of the base material of terminals Ts and Tb will deviate. In this case, the molten base material will detach from the area where the terminals Ts and Tb are gathered and fall, and the amount of base material mixed in the molten state may be insufficient. As a result, welding defects may occur in the terminals Ts and Tb being welded. As in one aspect of this embodiment, by setting the welding start position Ps to the center of gravity, this situation can be appropriately prevented. In the welding area of ​​a pair of terminals Ts and Tb, terminals Ts and Tb are mixed with each other, which can reduce the possibility of poor bonding caused by insufficient mixing of terminals Ts and Tb.

[0222] (3) In (1) above, when the start position determination unit 512 can identify the area of ​​the terminals Ts and Tb (multiple components) defined by the contour lines Lns and Lnb as an independent area surrounded by two contours, it determines the midpoint of the line connecting the centroid G of one area and the centroid G of the other area as the start position Ps.

[0223] Even if a pair of components (terminals Ts, Tb) are arranged with a gap before welding, and the gap between the two regions is such that the molten ball C will not fall, the midpoint of the line connecting the center of gravity G of one component and the center of gravity G of the other component will be taken as the welding start position Ps.

[0224] Therefore, the molten spheres C generated during welding due to the melting of the base material of terminals Ts and Tb (each component) can be generated across multiple components without falling into the gaps. Thus, terminals Ts and Tb can be properly welded to each other.

[0225] (4) In (2) or (3) above, the 3D camera 4 (information acquisition unit) is able to acquire distance information to terminals Ts and Tb (multiple components) respectively.

[0226] The starting position determination unit 512 corrects the position of the starting position Ps in the direction relative to the welding torch 2 (the straight line Za direction) based on distance information.

[0227] When welding terminals Ts and Tb (multiple components), if the position of the welding torch 2 is fixed in the relative direction between terminals Ts and Tb and the welding torch 2, then if one of the terminals Ts and Tb is positioned closer to the welding torch 2 than the other, the current flowing through one component will be greater than the current flowing through the other component. As a result, sometimes insufficient welding of terminals Ts and Tb may occur.

[0228] Additionally, it is possible that the welding torch 2 is too far away from terminals Ts and Tb, or that the welding torch 2 interferes with one of the terminals. In such cases, the welding of terminals Ts and Tb may be insufficient.

[0229] Specifically, if the distance between the welding torch 2 and terminals Ts and Tb is too large, the energy input to each terminal Ts and Tb during welding will decrease. In this case, the amount (volume) of the base material of terminals Ts and Tb melts will decrease, resulting in a lower weld strength. Conversely, if the distance between the welding torch 2 and terminals Ts and Tb is too short, the energy input to each terminal Ts and Tb during welding will be too large. In this case, the molten spheres C generated by the melting of the base material of terminals Ts and Tb will exceed the surface tension limit and move from the welding points of terminals Ts and Tb, resulting in a lower weld strength.

[0230] In one of the above methods, the distance information of each terminal Ts and Tb is obtained, and based on the obtained distance information, the welding start position Ps (the position of the front end of the welding torch 2) in the relative direction between the welding torch 2 and the terminals Ts and Tb is corrected.

[0231] Therefore, considering the deviation in the distance between each terminal Ts and Tb, that is, the deviation in the position of each terminal Ts and Tb, the welding start position Ps is corrected, so that the welding of terminals Ts and Tb can be performed appropriately.

[0232] (5) In (4) above, the information acquisition unit is a 3D camera 4.

[0233] According to one embodiment of the present invention, the distances to terminals Ts and Tb can be determined based on images of the areas where terminals Ts and Tb are located. Therefore, considering the positional deviations of terminals Ts and Tb, the soldering start position Ps is corrected, and thus the soldering of terminals Ts and Tb can be performed appropriately.

[0234] The processing of images captured by the 3D camera 4 has a low processing burden in the control device 5. As a result, the welding position can be determined more easily, and welding can be performed appropriately.

[0235] (I) In any of the above (1)-(5), the areas of the opposite portions of terminals Ts and Tb and welding torch 2 are different.

[0236] If the boundary between the terminals Ts and Tb to be welded is set as the welding start position Ps, the areas of the portions of terminals Ts and Tb opposite to the welding torch 2 are different. Therefore, sometimes the start position Ps is determined to be the position of one of the terminals Ts. In this case, there is a possibility that the other terminal Tb will not melt sufficiently, resulting in a poor weld. According to one aspect of the present invention, by determining the centroid of the area where terminals Ts and Tb are located as the start position Ps, the possibility of this happening can be reduced.

[0237] (II) In any of (1) to (5) and (I) above, the terminals Ts and Tb include multiple terminals Ts on the stator S (stator coil) side and multiple terminals Tb on the busbar 8 side.

[0238] There are multiple terminal groups consisting of a terminal Ts on the S side of the stator and a terminal Tb on the 8 side of the busbar.

[0239] The 3D camera 4 is capable of simultaneously acquiring information about the areas of each terminal group contained in a specified number of terminal groups.

[0240] The start position determination unit 512 determines the start position Ps for each terminal group based on the outline information of each terminal group obtained at the same time.

[0241] The welding control unit 511 (control unit) sequentially performs welding on the terminal group whose starting position Ps is determined.

[0242] With this configuration, when there are multiple terminal groups to be soldered, the soldering start position Ps can be determined for a specified number of terminal groups at once. Compared to determining the start position Ps by obtaining information about the area of ​​each terminal group, it is expected that the time required to complete soldering of all terminal groups can be reduced.

[0243] This invention can be understood as a welding method that uses a welding torch 2 to weld terminals Ts and Tb (multiple components) together.

[0244] (6) The welding method has the following steps: obtaining information about the area where the terminals (Ts, Tb) are located as observed from the welding torch (2) side; determining the welding start position (Ps) based on the contour information of the area where the terminals (Ts, Tb) are located; moving the welding torch (2) to the start position (Ps) and welding the terminals (Ts, Tb) to each other.

[0245] In the step of determining the welding start position Ps, the centroid G of the area where terminals Ts and Tb are located is determined based on the contour information of the area where terminals Ts and Tb are located, and the determined centroid G is used to determine the start position Ps.

[0246] According to one aspect of the present invention, compared to simply setting the starting position Ps on the boundary line between terminals Ts and Tb, it is possible to suppress the offset of the molten ball C caused by the melting of the base material of terminals Ts and Tb during welding, and thus terminals Ts and Tb can be welded properly.

[0247] (III) In (6) above, in the step of determining the welding start position Ps, if the area where the terminals Ts and Tb are located can be identified as an area surrounded by a contour line Ln based on the contour information, the centroid G of the area surrounded by a contour line Ln is determined, and the determined centroid G is determined as the start position Ps.

[0248] According to one aspect of the invention, even if there are gaps between terminals Ts and Tb (multiple components), if the gaps are small enough that the molten balls C do not flow in, they are considered to be areas enclosed by a contour line Ln. Thus, even if the center of gravity G of the area enclosed by the contour line Ln is determined as the starting position Ps, the molten balls C generated during welding due to the melting of the base material of terminals Ts and Tb (each component) are generated across multiple components with the center of gravity G as the center, thereby enabling the terminals Ts and Tb to be properly welded together.

[0249] (IV) In (6) above, in the step of determining the welding start position Ps, if the area where the terminals Ts and Tb are located can be identified as an area surrounded by two contours based on the contour information, the midpoint of the line segment Lg connecting the centroid G of one area and the centroid G of the other area is determined as the start position Ps.

[0250] According to one aspect of the invention, even when a pair of components (terminals Ts, Tb) are arranged with a gap before welding, and the gap between the two regions is such that the molten ball C will not fall, the midpoint of the line connecting the center of gravity G of one component and the center of gravity G of the other component is taken as the welding start position Ps.

[0251] Therefore, the molten spheres C generated during welding due to the melting of the base material of terminals Ts and Tb (each component) can be generated across multiple components without falling into the gaps. Thus, terminals Ts and Tb can be properly welded to each other.

[0252] The embodiments of the present invention have been described above, but the present invention is not limited to the embodiments shown therein. The above embodiments exemplify an electric motor for a vehicle, but can also be applied to electric motors other than those used in vehicles. The present invention can be appropriately modified within the scope of its inventive concept.

[0253] Explanation of reference numerals in the attached figures

[0254] 1: Welding equipment

[0255] 2: Welding torch

[0256] 22: Electrode rod

[0257] 3: 3D Camera (Information Acquisition Department)

[0258] 5: Control device (control unit)

[0259] 512: Starting Position Determination Department

[0260] C: Molten spheres

[0261] G: Center of gravity

[0262] Lns, Lnb: Contour lines (contour information)

[0263] Ps: Starting position (welding start position)

[0264] Ts, Tb: Terminals (multiple components)

Claims

1. A welding apparatus for welding multiple components together, the welding apparatus characterized by having: Welding torch; An information acquisition unit is capable of acquiring information about the area where the plurality of components are located, as observed from the welding torch side; A control unit that controls the welding process of the welding torch. The control unit has a start position determination unit that determines the welding start position of the welding torch. The starting position determination unit determines the center of gravity of the region where the multiple components are located based on the contour information of the region, and uses the determined center of gravity to determine the starting position.

2. The welding apparatus according to claim 1, characterized in that, When the region where multiple components are located can be identified as a region surrounded by a single contour based on the contour information, the starting position determination unit determines the center of gravity of the region surrounded by the single contour and determines the determined center of gravity as the starting position.

3. The welding apparatus according to claim 1, characterized in that, When the region where multiple components are located can be identified as a region surrounded by two contours based on the contour information, the starting position determination unit determines the starting position as the midpoint of the line connecting the center of gravity of one region and the center of gravity of another region.

4. The welding apparatus according to claim 2 or 3, characterized in that, The information acquisition unit is able to acquire the distance information of each of the multiple components. The starting position determination unit corrects the starting position in the relative direction opposite to the welding torch based on the distance information.

5. The welding apparatus according to claim 4, characterized in that, The information acquisition unit is a 3D camera.

6. A welding method for welding multiple components together using a welding torch, the welding method being characterized by comprising the following steps: Obtain information about the area where the plurality of components are located, as observed from the side of the welding torch; The welding start position is determined based on the contour information of the area where the multiple components are located; The welding torch is moved to the starting position to weld the plurality of components together. In the step of determining the welding start position, the center of gravity of the region where the plurality of components are located is determined based on the contour information of the region where the plurality of components are located, and the determined center of gravity is used to determine the start position.

Images