JP2006334628A - Welding apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the productivity by simply controlling the posture of a workpiece to be welded. <P>SOLUTION: When a plurality of car body frames 11, which are arranged in a line and have the same shape and are welded as workpieces, are held by means of a workpiece holding device 12, and are welded at the same time, the car body frames 11 are vertically and horizontally moved via the workpiece holding device 12 such that the welding portions of the car body frames 11 are opposed to welding torches 13 corresponding to the respective car body frames 11 respectively, and the posture of all of the car body frames 11 is changed at the same time by turning the workpiece holding device 12 about a straight line 161 arranged in parallel with the row of the workpieces. In addition, a welding apparatus comprises a workpiece holding mechanism 18 for holding the car body frames 11 such that a welding plane is provided on a plane approximately arranged in parallel with the direction of the row of the car body frames 11, and a welding mechanism 14 having the welding torches 13 arranged so as to be in one line arranged in parallel with the direction of the row of the car body frames 11 and so as to be opposed to the car body frames 11 respectively. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a welding apparatus that simultaneously welds a plurality of workpieces using a plurality of welding torches.

As a conventional welding device, when welding a motorcycle frame, which is a workpiece, in order to prevent the weld bead from being biased or drooping, the welding torch is not moved but the workpiece is moved and welded. (For example, refer to Patent Document 1).
Moreover, what welds several welding torches with respect to one welding target object is known (for example, refer patent document 2).
JP-A 64-78676 JP 2003-334775 A

FIG. 2 of Patent Document 1 will be described with reference to FIG. 15 below. In addition, the code | symbol was reassigned.
FIG. 15 is a perspective view showing a conventional welding apparatus. The welding apparatus 301 holds an articulated robot 302 and a front frame 303 for a motorcycle as a work at the arm end of the robot 302. A welding jig 304 attached to the welding torch 306 and a welding torch 306 are provided, and welding is performed by moving the front frame 303 while changing its posture by the robot 302 so that the welding location faces the welding torch 306.

FIG. 1 of Patent Document 2 will be described with reference to FIG. In addition, the code | symbol was reassigned.
FIG. 16 is a cross-sectional view showing a conventional welding apparatus. A welding robot apparatus 311 as a welding apparatus has a traveling carriage 313 movably attached to a support frame 312, and a turning frame is attached to the traveling carriage 313 via a θ axis 314. 316 is attached, and two manipulators 317 and 317 each provided with a welding torch are attached to the swivel frame 316, and a welding object 318 positioned below is welded by these manipulators 317 and 317.

  In FIG. 15, when a plurality of front frames 303 are moved and a plurality of front frames 303 are welded in one step using a plurality of welding torches 306, each front frame 303 is individually separated. It is necessary to move / rotate the robot frame 302, and the control when the robot 302 performs such an operation for each front frame 303 becomes complicated.

Further, since the front frame 303 is moved and welded, the front frames 303 may interfere with each other when the front frame 303 is rotated around a plurality of axes. If the robot 302 is controlled to prevent such interference, more complicated control is required.
Further, when the front frame 303 is rotated around a plurality of axes, the welding path becomes complicated, and it becomes difficult to calculate the welding posture of the front frame 303 in the control device that controls the operation of the robot 302, resulting in a slow welding speed. Become.

  In FIG. 16, when welding one welding object 318 with two manipulators 317 and 317, the traveling carriage 313 is moved to weld a plurality of welding objects 318 sequentially. There is a limit to increasing the moving speed of 313, and it is difficult to increase the number of units that can be welded per unit time.

  An object of the present invention is to improve the productivity by improving the welding apparatus so as to simplify the posture control of the workpiece to be welded.

  According to the first aspect of the present invention, when a plurality of workpieces having the same shape arranged in a row are held by a workpiece holder and the plurality of workpieces are welded at the same time, the welding locations of the workpieces are respectively connected to the welding torch corresponding to each workpiece. The workpieces are moved up and down and horizontally through the workpiece holders so as to face each other, and the workpiece holders are rotated around a workpiece rotation axis parallel to the direction of the workpiece rows to change the postures of all the workpieces simultaneously. In addition, a work holding mechanism that holds the workpiece so that a welding surface is provided on a plane that is substantially parallel to the direction of the workpiece row, and a welding torch that is arranged in parallel with the workpiece row direction so as to face the workpiece in a row. And a mechanism.

By rotating the workpiece holder around a single workpiece rotation axis, the workpiece rotation is simplified compared to rotating the workpiece posture around multiple rotation axes. In addition, since it is possible to perform welding by changing the postures of a plurality of workpieces simultaneously and in the same manner, the control becomes simpler than controlling the postures of the workpieces separately.
Furthermore, since a plurality of workpieces are welded simultaneously, the number of welds per unit time can be increased.

The invention according to claim 2 is characterized in that the welding torch is rotated about a rotation axis of the torch parallel to the direction of the row of the welding torch to prevent the welding torch from interfering with the workpiece.
By ensuring that the workpiece does not interfere with the welding torch, welding can be performed smoothly.

The invention according to claim 3 is characterized in that the workpiece is a frame having a closed cross section by combining plate materials having a U-shaped cross section.
For example, a plate material having a U-shaped cross section can be easily formed by press molding. Further, by combining two U-shaped plate materials, a frame having a closed cross section can be easily formed, and the frame can be made lightweight and highly rigid. Furthermore, since the weld surfaces of the lap joint are formed on the upper and lower surfaces of the workpiece, welding can be performed with simple control of the posture of the workpiece.

The invention according to claim 4 is characterized in that the workpiece is a frame of a motorcycle.
The motorcycle having a closed cross-sectional shape makes the motorcycle lighter and more rigid.

  In the invention according to claim 1, since the posture of the workpiece is changed only by rotation around one workpiece rotation axis and movement in the vertical and horizontal directions, the posture control of the workpiece can be simplified and the welding speed is improved. Thus, the cycle time of one process can be shortened. Furthermore, since it becomes possible to weld a some workpiece | work simultaneously, the number of production per unit time can be increased. Therefore, productivity can be improved.

  In the invention according to claim 2, since the welding torch is rotated around the torch rotating shaft to prevent interference between the workpiece and the welding torch, the workpiece can be welded smoothly, and the welding cycle time can be shortened. it can.

  In the invention according to claim 3, the plate material can be easily formed into a U-shaped cross section, and a frame having a closed cross section can be easily formed by combining two plate materials having a U-shaped cross section. Therefore, the cost can be reduced, and the workpiece can be made light and highly rigid. Furthermore, since welding surfaces are formed on the upper and lower surfaces, welding can be performed with simple control of the posture of the workpiece.

  In the invention according to claim 4, since the work has a closed cross-sectional shape, it is possible to reduce the weight and rigidity of the motorcycle, and further, it is possible to reduce the cost of the motorcycle by a frame that can be easily formed. .

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a perspective view showing a welding apparatus according to the present invention. A welding apparatus 10 is used for welding a workpiece holder 12 that holds a body frame 11 for a motorcycle as a workpiece and a body frame 11 that is held. It comprises a welding mechanism 14 having welding torches 13 for MIG welding, a holder driving device 16 for driving the work holder 12, and a controller 17 for controlling the welding mechanism 14 and the holder driving device 16. . The workpiece holder 12 and the holder driving device 16 constitute a workpiece holding mechanism 18.

The vehicle body frame 11 includes a plurality of press-formed plate materials and pipe materials, and the plate materials are tailored blank materials in which steel plates having different plate thicknesses are joined in advance.
The workpiece holder 12 includes a first workpiece holding portion 21 and a second workpiece holding portion 22 that can hold a plurality of body frames 11 having the same shape, here two arranged in a row in the X-axis direction.

  The first work holding portion 21 includes a horizontal bar 81 on which the vehicle body frame 11 is placed, a head pipe holding portion 82 that holds the head pipe 31 that is the front end portion of the vehicle body frame 11, and a pair of left and right members that are positioned substantially at the center of the vehicle body frame 11. The pivot holding portion 83 holds the left pivot support plate 32 and the right pivot support plate 33 (not shown), and the rear end holding portion 84 holds the rear end portion of the vehicle body frame 11. The second work holding part 22 has the same structure as the first work holding part 21, and a description thereof will be omitted. Reference numeral 86 denotes a driving device connecting portion that connects to the holder driving device 16.

  The welding mechanism 14 includes a welding torch 13, 13 provided for each vehicle body frame 11, a torch first drive motor 203 that rotates these welding torches 13, 13 around the X axis in the figure, and one welding torch 13. A torch second drive motor 204 that moves in the X-axis direction and torch third drive motors 206 and 207 that rotate the welding torches 13 and 13 around the Z-axis in the figure are provided.

  The holder driving device 16 is an articulated robot, and moves the workpiece holder 12 horizontally (moving in the X-axis direction and Y-axis direction), vertically moving (moving in the Z-axis direction), and rotating (rotating around the X-axis). ).

FIG. 2 is a perspective view showing a state before joining of workpieces according to the present invention, and a body frame before welding as a workpiece is 11A here.
The body frame 11A includes a left frame half body 34 and a right frame half body 35 coupled to the left and right, and a rear frame part 36 coupled to the inner side of each of the left frame half body 34 and the right frame half body 35. And the above-described head pipe 31, a cylindrical pivot support portion 37, and a rear cross frame 38 attached to the rear end of the rear half frame body 36. In addition, 41 and 42 are cross pipes, 43 is a cross member.
The left frame half 34 and the right frame half 35 described above are members constituting the front frame half 44.

  The left frame half 34 includes a left main frame portion 45, a left outer seat rail portion 46 provided at a rear portion of the left main frame portion 45, and a connecting portion between the left main frame portion 45 and the left outer seat rail portion 46. And a left pivot support plate 32 extending downward from the bottom.

  The right frame half 35 includes a right main frame portion 51, a right outer seat rail portion 52 provided at a rear portion of the right main frame portion 51, and a connecting portion between the right main frame portion 51 and the right outer seat rail portion 52. The head pipe 31 is temporarily joined to the right main frame portion 51 in advance.

  The pivot support portion 37 is a member that is joined by welding through pivot mounting holes 32a and 33a formed in the left pivot support plate 32 and the right pivot support plate portion 33, respectively.

  The cross pipe 42 is a member that is joined to the left pivot support plate 32 and the right pivot support plate portion 33 by welding through the cross pipe mounting holes 32b and 33b that are respectively opened.

The rear half frame body 36 is a member formed by integrally forming a wide front portion 55 and a left inner seat rail portion 56 and a right inner seat rail portion 57 extending rearward from the left and right of the front portion 55.
The rear cross frame 38 is a member made up of a plurality of plates, and includes a pair of left and right rear protrusions 38a, 38a.

FIG. 3 is a perspective view showing a state after the workpieces according to the present invention are joined. Here, the body frame after welding as the workpiece is 11B.
The body frame 11B is welded together with the left main frame portion 45 and the right main frame portion 51, and the rear end portion of each of the left main frame portion 45 and the right main frame portion 51 and the front portion of the rear half frame body 36. The members 55 are welded together, the left outer seat rail portion 46 and the left inner seat rail portion 56 are welded together, and the right outer seat rail portion 52 and the right inner seat rail portion 57 are welded together. .

  The left main frame portion 45 and the right main frame portion 51 constitute a main frame 61, the left outer seat rail portion 46 and the left inner seat rail portion 56 constitute a seat rail 62, and the right outer seat rail portion 52. The right inner seat rail portion 57 is a portion constituting the seat rail 63.

FIG. 4 is a cross-sectional view of a vehicle body frame according to the present invention.
3A is a cross-sectional view taken along the line aa of FIG. 3, and the main frame 61 has a left main body having a substantially C-shaped cross section outside the right main frame portion 51 having a substantially C-shaped cross section. Covering the frame portion 45, the upper wall 51a of the right main frame portion 51 and the upper wall 45a of the left main frame portion 45 are overlapped, and the lower wall 51b of the right main frame portion 51 and the lower wall 45b of the left main frame portion 45 are These are the members welded by fillet welding. The welding torch 13 is welded with an inclination of 45 ° with respect to the upper walls 51a and 45a and the lower walls 51b and 45b. This angle is the same for the seat rails 62 and 63 (see FIG. 3).

  3B is a cross-sectional view taken along the line bb in FIG. 3, and the seat rail 63 covers the right inner seat rail portion 57 on the outer side of the right outer seat rail portion 52 whose cross section is formed in a U shape, and the right outer seat. The upper wall 52a of the rail portion 52 and the upper wall 57a of the right inner seat rail portion 57 are overlapped, and the lower wall 52b of the right outer seat rail portion 52 and the lower wall 57b of the right inner seat rail portion 57 are overlapped, respectively. This is a fillet welded member.

  3C is a cross-sectional view taken along the line cc of FIG. 3, and the seat rail 62 covers the left inner seat rail portion 56 on the outer side of the left outer seat rail portion 46 having a U-shaped cross section, and the left outer seat. The upper wall 46a of the rail portion 46 and the upper wall 56a of the left inner seat rail portion 56 are overlapped, and the lower wall 46b of the left outer seat rail portion 46 and the lower wall 56b of the left inner seat rail portion 56 are overlapped, respectively. This is a fillet welded member.

  FIG. 5 is a perspective view of the workpiece holder according to the present invention. The workpiece holder 12 includes a vertical frame 90, a horizontal frame 91 and a vertical frame 92 attached to both ends of the vertical frame 90, and both ends of the horizontal frame 91. The above-mentioned head pipe holding parts 82 and 82 attached to the parts, side holding mechanisms 94 and 96 arranged on both sides of the vertical frame 90 and the vertical frame 92, a rear holding mechanism 97 attached to the upper part of the vertical frame 92, It comprises a drive device connecting portion 86 connected to the holder drive device 16 (see FIG. 1). Reference numeral 98 denotes a connecting frame included in the driving device connecting portion 86, which extends from the lower part of the vertical frame 92 to one side.

  The head pipe holding portion 82 includes a pedestal 101 attached to the horizontal frame 91, a head pipe lower holding member 102 and a column 103 attached to the pedestal 101, a cylinder device 104 attached to a side portion of the column 103, and a column 103. And an arm 107 having a rod device 106 coupled to one end thereof and a head pipe upper holding member 108 attached to the other end of the arm 107.

  The cylinder device 104 includes a cylinder main body 111, a piston (not shown) movably inserted into the cylinder main body 111, and a rod 106 attached to the piston. By supplying oil from one of the outlets 113 and 114 and discharging oil from the other, the rod 106 is moved forward and backward, the arm 107 is swung, and the head pipe lower holding member 102 and the head pipe upper holding member 108 are In between, the head pipe 31 (see FIG. 2) is clamped or unclamped.

  The side holding mechanism 94 includes side plates 116 and 116 attached to both side surfaces of the vertical frame 90 and the vertical frame 92, a horizontal bar 81 and a pivot holding portion 83 attached to the side plate 116. The side holding mechanism 96 has the same structure as the side holding mechanism 94, and a description thereof will be omitted.

  The pivot holding portion 83 includes an inner holding portion 118 that is directly attached to the side plate 116 and an outer holding portion 122 that is attached to the side plate 116 via two support columns 121 and 121.

  The inner holding portion 118 includes a base portion 124, a pin cradle 126 attached to a side end portion of the base portion 124, and one end of the pivot support portion 37 (see FIG. 2). It consists of an inner pivot support pin 127 attached to the tip.

  The outer holding portion 122 includes a base plate 131 attached to the tips of the columns 121 and 121, two cylinder devices 132 and 132 (only one symbol 132 is shown) attached to the base plate 131, and these cylinder devices 132. , 132, a pin receiving plate 134 attached to rods 133, 133 (not shown), and an outer pivot support pin 136 attached to the pin receiving plate 134 to support the other end of the pivot support portion 37. .

  The cylinder device 132 includes a cylinder body 138, a piston (not shown) that is movably inserted into the cylinder body 138, and a rod 133 (not shown) attached to the piston. By supplying, the pin receiving plate 134 is moved via the rod 133, and both end portions of the pivot support portion 37 are supported by the inner pivot support pin 127 and the outer pivot support pin 136.

  The rear holding mechanism 97 includes an inclined frame 141 extending obliquely rearward and upward from the back surface of the vertical frame 92, a rear horizontal frame 142 attached so as to be orthogonal to the tip of the inclined frame 141, and both ends of the rear horizontal frame 142. The rear end holding portions 84 and 84 are provided.

FIG. 6 is a perspective view showing the rear holding mechanism of the work holder according to the present invention, and the rear end holding portion 84 of the rear holding mechanism 97 is a lower plate attached to both ends of the rear horizontal frame 142 via the base plate 144. 145 and the cylinder device 146, a swing arm 147 swingably attached to the upper part of the lower plate 145, and a pair of guides attached to the lower plate 145 with a space left and right to serve as a guide for holding the vehicle body frame Plate 148, 151 (see also FIG. 5).
The lower plate 145 includes teeth 152, 152 on the upper side, and the swing arm 147 includes teeth 153, 153 that mesh with the teeth 152, 152 on the lower side.

  The cylinder device 146 includes a cylinder body 155, a piston (not shown) movably inserted into the cylinder body 155, and a rod 156 attached to the piston. The tip of the rod 156 is connected to one end of the swing arm 147. By connecting, when oil is supplied into the cylinder body 155 from the oil supply / discharge port 157 (or the oil supply / discharge port 158), the rod 156 is extended and the swing arm 147 is swung, so that the rear cross frame of the vehicle body frame. 38 (see FIG. 2), specifically, the rear protrusions 38a and 38a (see FIG. 2) are sandwiched between the tooth portions 152 and the tooth portions 153 and fixed.

  FIG. 7 is a plan view of the work holder according to the present invention. The work holder 12 is arranged with respect to a straight line 160 passing on the vertical frame 90 except for the head pipe holding portions 82 and 82 and the drive device connecting portion 86. It has a symmetrical structure and can be rotated around a straight line 161 by a holder driving device 16 (see FIG. 1). The first work holding part 21 and the second work holding part 22 are symmetrical with respect to the straight line 160 except for the head pipe holding parts 82 and 82.

  FIG. 8 is a front view of the welding mechanism according to the present invention. The welding mechanism 14 includes a column 211 raised from the floor, and a torch first drive motor 203 attached to the upper portion of the column 211 with brackets 212 and 213. , Bearings 215 and 215 attached to the upper end of the column 211 to rotatably support the rotary shaft 203a of the first drive motor 203, an L-shaped frame 216 attached to the tip of the rotary shaft 203a, A torch third drive motor 206 attached to the tip of the L-shaped frame 216, one welding torch 13 attached to the rotating shaft 206a of the torch third drive motor 206 via an arc-shaped bracket 217, and an L-shape The torch second drive motor 204 and the torch moving rail 218 attached to the frame frame 216, and attached to the torch moving rail 218 so as to be movable. The torch third drive motor 207, the other welding torch 13 attached to the rotation shaft 207a of the torch third drive motor 207 via the arc-shaped bracket 217, and the rotation shaft 204a of the torch second drive motor 204 are connected. A feed screw member 221 that is screw-coupled to a nut member (not shown) provided on the torch third drive motor 207 side, a beam member 222 that extends laterally from the top of the column 211, and a welding surface of the workpiece during welding In order to support the work surface on the other side, work support members 223 and 223 attached to the upper surface of the beam member 222 so as to be extendable and contractable.

  The torch third drive motor 206 is fixed to the L-shaped frame 216, and the torch third drive motor 207 drives the torch second drive motor 204 to rotate the feed screw member 221, thereby rotating the L-shaped frame 216. The torch moving rail 218 is movable, and the welding torch 13 can be moved in accordance with the interval between the workpieces held by the workpiece holder 12 (see FIG. 7).

The arc-shaped bracket 217 is a member that can change the angle of the welding torch 13 with respect to the workpiece by changing the mounting position of the welding torch 13.
In the figure, reference numeral 225 denotes an axis of the rotation shaft 203a of the torch first drive motor 203, which is an axis on which the L-shaped frame 216 rotates. As the L-shaped frame 216 rotates, the welding torches 13 and 13 rotate around the X axis.

The welding procedure of the vehicle body frame 11A by the welding apparatus 10 described above will be described with reference to FIGS.
9 (a) and 9 (b) are first operational views showing the welding procedure of the vehicle body frame according to the present invention.
In (a), first, the welding torch 13 is inclined by 45 ° with respect to the vertical direction relative to the body frame 11A (that is, the Y-axis direction) (and as shown in FIG. The direction of the row of the vehicle body frames (that is, the X-axis direction) is also inclined by 45 ° with respect to the vertical direction.) The welding start point (main frame) of the main frame 61 that is a welding point at the tip of the welding torch 13 61, the workpiece holder 12 is moved by the holder driving device 16 so that the welding pipe faces the head pipe 31 side, and the welding surface with respect to the welding torch 13 is 45 ° in a side view. As shown by an arrow A from the state in which the head pipe 31 shown in FIG. 1 is upright, the workpiece holder 12 is rotated around a straight line 161 (straight line 161 is indicated by a black circle; the same applies hereinafter) 16. Rotated with That. Thereafter, the welding surface of the body frame 11 </ b> A is always inclined with respect to the welding torch 13 in the direction of 45 ° welding. That is, the welding surface at the time of welding the body frame 11A always faces upward. In this way, by directing the welding surface upward, it is possible to prevent the molten metal from dripping during welding and to obtain good welding quality.

  (B) moves the workpiece holder 12 from the state of (a) in the Y-axis direction, the Z-axis direction and the X-axis direction (front and back in the figure) and rotates around the straight line 161 as an arrow B. The welding torch 13 is moved relative to the vehicle body frame 11A as indicated by the dashed arrow C to weld the upper surface of the main frame 61.

10 (a) and 10 (b) are second operational views showing the welding procedure of the vehicle body frame according to the present invention.
(A) After the upper surface of the main frame 61 is welded, the torch third drive motors 206 and 207 (see FIG. 8) are driven to rotate the welding torch 13 about the vertical axis by 180 ° and the workpiece holder 12. Is moved in the Y-axis direction, the Z-axis direction, and the X-axis direction (front and back directions in the figure), and rotated about the straight line 161 so that the body frame 11A is rotated by approximately 180 ° so that the lower surface of the main frame 61 faces upward. The welding torch 13 is exposed to the welding start position on the lower surface of the main frame 61.

  That is, the welding torch 13 is inclined by 45 ° with respect to the vertical direction in the direction of travel relative to the body frame 11A (that is, the Y-axis direction), and as shown in FIG. (Ie, the X-axis direction) is also inclined by 45 ° with respect to the vertical direction, and as shown in FIG. 10, the welding surface of the vehicle body frame 11 </ b> A always faces upward.

  From this state, the work holder 12 is moved in the Y-axis direction, the Z-axis direction, and the X-axis direction (front and back directions in the figure) and rotated around the straight line 161 so that the welding torch 13 is broken with respect to the vehicle body frame 11A. The relative movement as shown by the arrow E indicates that the lower surface of the main frame 61 is welded.

  (B) After the lower surface of the main frame 61 is welded, the work holder 12 is rotated around the straight line 161 and moved in the Y-axis direction, the Z-axis direction, and the X-axis direction (front and back directions in the figure) The rear end portion that is the welding start position of one of the seat rails 63 is allowed to face the welding torch 13. Then, the work holder 12 is moved in the Y-axis direction, the Z-axis direction, and the X-axis direction (front and back directions in the figure) and rotated around the straight line 161 so that the welding torch 13 is indicated by a broken arrow F with respect to the vehicle body frame 11A. Move relative to the center as shown.

FIGS. 11 (a) and 11 (b) are third operational views showing the welding procedure of the vehicle body frame according to the present invention.
(A) shows the state which welds the upper surface of the seat rail 63 in the direction of arrow G following FIG.10 (b). As the work holder 12 moves, the head pipe 31 side of the vehicle body frame 11 </ b> A is greatly raised by the rotation around the straight line 161.

  (B), after the welding of the upper surface of one seat rail 63 is completed and the upper surface of the other seat rail 63 is welded in the same manner as the upper surface of one seat rail 63, the torch third drive motors 206, 207 (Refer to FIG. 8), the welding torch 13 is rotated by 180 ° around the vertical axis, the work holder 12 is moved in the Y-axis direction, the Z-axis direction, and the X-axis direction (front and back in the figure), and The body frame 11A is rotated approximately 180 ° so that the lower surface of the seat rail 63 faces upward by rotating around the straight line 161, and the welding torch 13 is the welding start position of the lower surface of one seat rail 63. Let the rear end face.

Then, the work holder 12 is moved in the Y-axis direction, the Z-axis direction, and the X-axis direction (the front and back directions in the figure) and rotated around the straight line 161 so that the welding torch 13 is indicated by the broken arrow H with respect to the vehicle body frame 11A. It is shown that the lower surface of the seat rail 63 is welded toward the center part by relative movement as described above.
Next, similarly to the lower surface of one seat rail 63, the lower surface of the other seat rail 63 is welded from the rear end portion toward the center portion.

FIGS. 12A and 12B are fourth operation views showing the welding procedure for the vehicle body frame according to the present invention, and the welding procedure for the seat rail 63 is shown again in plan view.
In (a), the rear end portion of the seat rail 63 of the body frame 11 </ b> A is caused to face the front end of the welding torch 13.

  In (b), the work holder 12 is moved in the X-axis direction, the Y-axis direction, and the Z-axis direction (front and back in the figure) and rotated around a straight line 161 (see FIG. 10B), so that the welding torch 13 is rotated. Is moved relative to the vehicle body frame 11A toward the center as shown by the broken arrow K. In the figure, 65 is a weld line on the upper surface of the main frame 61, 66 is a weld line on the upper surface of the seat rail 62, and 67 is a weld line on the upper surface of the seat rail 63. (See FIGS. 4A to 4C for the weld lines 71 to 73 on the lower surfaces of the main frame 61 and the seat rails 62 and 63.)

The welding sequence and the welding direction described in FIGS. 9 to 12 will be described again with reference to FIG.
FIG. 13 is an operation diagram showing the welding sequence and the welding direction of the vehicle body frame according to the present invention.
The body frame 11A is welded in the following order and direction so that the welding distortion is minimized.
(1) The upper surface 61a of the main frame 61 is welded from the front end portion 61c toward the center portion 11c as indicated by an arrow.
(2) The lower surface 61b (not shown) of the main frame 61 is welded from the front end portion 61c toward the central portion 11c as indicated by an arrow.

(3) The upper surface 63a of the seat rail 63 is welded from the rear end portion 63c toward the central portion 11c as indicated by an arrow.
(4) The upper surface 62a of the seat rail 62 is welded from the rear end portion 62c toward the center portion 11c as indicated by an arrow.
(5) The lower surface 63b (not shown) of the seat rail 63 is welded from the rear end portion 63c toward the central portion 11c as indicated by an arrow.
(6) The lower surface 62b (not shown) of the seat rail 62 is welded from the rear end portion 62c toward the central portion 11c as indicated by an arrow. Note that the welding order of the seat rail 62 and the seat rail 63 may be reversed.

The basis for setting the welding direction shown in FIG. 13 will be described below.
FIGS. 14A to 14D are operation diagrams showing the basis for setting the welding direction.
In the comparative example (a), for example, welding is performed by moving the welding torch 336 relative to the vehicle body frame 331 from the center portion 332 of the vehicle body frame 331 to the front end portion 334 of the main frame 333 constituting the vehicle body frame 331. In this case, since the center portion 332 has high rigidity and the front end portion 334 side of the main frame 333 has low rigidity, when welding is started from the center portion 332 having high rigidity, the electrode wire of the welding torch 336 and the base material of the vehicle body frame 331 are used. Is melted and solidified, and when the melting and solidification are repeated as the welding torch 336 is relatively moved, (A) the amount of contraction from the high rigidity side to the low rigidity side, and (B) the low rigidity side. (B)> (A) (see arrow) because the lower stiffness side is more likely to shrink than the higher stiffness side. That.

  Accordingly, the lower rigidity portion in the vicinity is deformed on the basis of the high rigidity portion, and then the lower rigidity portion is deformed on the basis of the deformed portion, so that the deformation approaches the low rigidity portion. It is considered that the amount of deformation on the front end portion 334 side of the main frame 333, that is, the welding strain increases when the front end portion 334 of the main frame 333 is welded. During actual welding, since the body frame 331 is fixed to the work holder, the deformation does not appear. However, when the body frame 331 is removed from the work holder, the force inherent in the body frame 331 tries to deform, The front end 334 of the main frame 333 largely warps upward as indicated by an imaginary line.

  In the example (this embodiment) of (b), welding is performed by moving the welding torch 13 relative to the vehicle body frame 11A from the front end portion 61c side to the center portion 11c side of the main frame 61 of the vehicle body frame 11A. Since the central portion 11c has high rigidity and the front end portion 61c side of the main frame 61 has low rigidity, when welding is started from the front end portion 61c side having low rigidity, the electrode wire and The base material of the body frame 11A is repeatedly melted and solidified. (A) An amount of contraction from a high rigidity side to a low rigidity side and (B) An amount of contraction from a low rigidity side to a high rigidity side. In comparison, since the absolute value of rigidity is low and it is far from the highly rigid part, it contracts almost uniformly regardless of the directions of (A) and (B). 11c Hardly deformed before reaching the portion with high rigidity cumulative amount of deformation of the front end portion 61c side (the welding strain) is considered not large.

  In the comparative example (c), for example, the welding torch 336 is moved relative to the vehicle body frame 331 from the center portion 332 of the vehicle body frame 331 to the rear end portion 342 of the seat rail 341 constituting the vehicle body frame 331. This is an example in the case of welding, and the central portion 332 has high rigidity, and the rigidity gradually decreases from the central portion 332 toward the rear end portion 342 side of the seat rail 341. Therefore, the rigidity from the central portion 332 having high rigidity is low. When welding toward the rear end portion 342, as in the case of (a), when the vehicle body frame 331 is removed from the work holder, the rearward of the seat rail 341 is caused by the force that tends to deform in the vehicle body frame 331. The end 342 side is greatly deformed, that is, greatly warps upward as indicated by an imaginary line.

  The embodiment of (d) is an example in which welding is performed by moving the welding torch 13 relative to the vehicle body frame 11A from the rear end 62c side of the seat rail 62 of the vehicle body frame 11A to the center portion 11c. If welding is performed from the rear end portion 62c with low rigidity toward the central portion 11c with high rigidity, the deformation on the rear end portion 62c side of the seat rail 62 does not increase as in the case of (c), and the upward Warpage is suppressed.

  As described above with reference to FIGS. 1 and 4, according to the present invention, first, a plurality of identically shaped body frames 11 arranged in a row are held by a workpiece holder 12, and a plurality of body frames 11 are held. When welding at the same time, the body frame 11 is moved up and down and horizontally through the work holder 12 so that the welded portions of the body frame 11 face the welding torches 13 corresponding to the body frames 11, respectively, and a row of workpieces. The workpiece holder 12 is rotated about a straight line 161 as a workpiece rotation axis parallel to the direction of the workpiece to change the postures of all the vehicle body frames 11 simultaneously and on a plane substantially parallel to the row direction of the vehicle body frames 11. A workpiece holding mechanism 18 for holding the vehicle body frame 11 so as to provide the welding surfaces 61a, 61b, 62a, 62b, 63a, 63b; A welding mechanism 14 respectively to the body frame 11 in parallel to a row and a direction of the columns so as to face to place the welding torch 13, characterized in that it has a.

Since the posture of the vehicle body frame 11 is changed by only rotating around one straight line 161 and moving in the vertical and horizontal directions, the posture control of the vehicle body frame 11 can be simplified, the welding speed is improved, and one process is performed. Cycle time can be shortened. Furthermore, since a plurality of body frames 11 can be welded simultaneously, the number of units produced per unit time can be increased. Therefore, productivity can be improved.
That is, as the number of body frames 11 increases, the number of production per unit time can be further increased.

  Secondly, the present invention prevents the welding torch 13 from interfering with the vehicle body frame 11 by rotating the welding mechanism 14 about the axis 225 as a torch rotation axis parallel to the direction of the row of the welding torch 13. It is characterized by doing so.

  Since the welding torch 13 is rotated around the axis 225 to prevent interference between the vehicle body frame 11 and the welding torch 13, the vehicle body frame 11 can be welded smoothly, and the cycle time of welding can be shortened.

Thirdly, the present invention is characterized in that the vehicle body frame 11 is a frame having a closed cross section by combining plate members having a U-shaped cross section.
The plate material can be easily formed into a U-shaped cross section, and the body frame 11 having a closed cross section can be easily formed by combining two plate materials having a U-shaped cross section. Therefore, the cost can be reduced, and the body frame 11 can be made lightweight and highly rigid. Furthermore, since welding surfaces are formed on the upper and lower surfaces of the vehicle body frame 11, welding can be performed with simple control of the posture of the vehicle body frame 11.

Fourthly, the present invention is characterized in that the body frame 11 is a frame of a motorcycle.
Since the vehicle body frame 11 has a closed cross-sectional shape, the motorcycle can be reduced in weight and rigidity, and the vehicle frame 11 that can be easily formed can reduce the cost of the motorcycle.

  In the present embodiment, as shown in FIG. 1, the vehicle body frames 11 as the workpieces are arranged in one row. However, the present invention is not limited to this, and the vehicle body frames 11 may be arranged in a plurality of rows.

  The welding apparatus of the present invention is suitable for mass production equipment because it can simultaneously weld a plurality of workpieces having the same shape.

It is a perspective view which shows the welding apparatus which concerns on this invention. It is a perspective view which shows the state before the coupling | bonding of the workpiece | work which concerns on this invention. It is a perspective view which shows the state after the coupling | bonding of the workpiece | work which concerns on this invention. It is sectional drawing of the vehicle body frame which concerns on this invention. It is a perspective view of the workpiece holder which concerns on this invention. It is a perspective view which shows the rear part holding | maintenance mechanism of the workpiece holder which concerns on this invention. It is a top view of the workpiece holder which concerns on this invention. It is a front view of the welding mechanism which concerns on this invention. It is the 1st operation view showing the welding point of the body frame concerning the present invention. It is a 2nd operation | movement figure which shows the welding procedure of the vehicle body frame which concerns on this invention. It is the 3rd operation figure showing the welding point of the body frame concerning the present invention. It is the 4th operation view showing the welding point of the body frame concerning the present invention. It is an effect | action figure which shows the welding order and welding direction of the vehicle body frame which concern on this invention. It is an effect | action figure which shows the basis of the setting of a welding direction. It is a perspective view which shows the conventional welding apparatus. It is sectional drawing which shows the conventional welding apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Welding apparatus, 11 ... Workpiece (body frame), 12 ... Work holder, 13 ... Welding torch, 14 ... Welding mechanism, 18 ... Work holding mechanism, 61a, 61b, 62a, 62b, 63a, 63b ... Weld surface 161... Work rotation axis (straight line), 225... Torch rotation axis (axis line).

Claims (4)

When holding a plurality of identically-shaped workpieces arranged in a row with a workpiece holder and welding a plurality of the workpieces simultaneously, the workpieces are placed so that the welding locations of the workpieces face the welding torches corresponding to the workpieces, respectively. While vertically moving and horizontally moving through the workpiece holder and rotating the workpiece holder around a workpiece rotation axis parallel to the direction of the row of workpieces, and simultaneously changing the posture of all the workpieces, A workpiece holding mechanism for holding the workpiece so as to provide a welding surface on a plane substantially parallel to the direction of the workpiece row;
A welding mechanism in which a welding torch is arranged to face each of the workpieces in a row parallel to the direction of the workpiece rows;
A welding apparatus comprising:   2. The welding apparatus according to claim 1, wherein the welding mechanism prevents the welding torch from interfering with the workpiece by rotating the welding torch about a rotation axis of the torch parallel to the direction of the row of the welding torches. .   The welding apparatus according to claim 1, wherein the workpiece is a frame having a closed cross-section by combining plate materials having a U-shaped cross-section.   The welding apparatus according to claim 1, wherein the workpiece is a frame of a motorcycle.

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