JPS606832B2 - car floor assembly line - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a floor assembly line for roughening the floors of automobiles.

A conventional automobile floor assembly line consists of only a large number of multi-spot welding machines installed along the line, and each multi-spot welding machine handles multiple parts that make up the floor and welds these parts. The fixture has a positioning section for mutual positioning and a welder for simultaneously spot welding the positioned members at a plurality of points.

However, such multi-spot welding machines can only be used for assembling the floor of a single type of car (specification) because the shape and structure of the fixture are completely different depending on the type (specification) of the car, and cannot be used as a dedicated machine. I had no choice. Therefore, when there is a model change, etc., it is necessary to discard the existing assembly line and install a large number of new multi-spot welding machines on the line to accommodate the changes, or to keep the assembly line for a long period of time (actually several (2013) was stopped and the fixtures were being replaced. For this reason, in the former case, not only is the equipment wasted, but a large amount of money is required each time new equipment is installed, and in the latter case, the assembly line is stopped for a long period of time, leaving equipment and personnel idle. There was a point.
Moreover, since it can only be used to assemble the floor of a single type of automobile, it is naturally impossible to assemble the floors of two different types of automobiles at the same time. This invention was made in view of the above-mentioned problems, and includes a multi-spot welding machine that spot-welds at least a tunnel portion of a floor.
A welding robot group as a general-purpose machine for spot welding welding points not welded by the multi-spot welding machine group is separated on the line, and a fixture of the multi-spot welding machine is installed on the side of the multi-spot welding machine. At the very least, we will provide another fixture that can be connected to the multi-spot welding machine and replace it in a short period of time. The purpose is to enable simultaneous assembly of different types of floors. The present invention will be explained below based on the drawings.

1 to 12 are diagrams showing an embodiment of the present invention. In Fig. 1, 1 is the welding assembly line on floor F;
This line l includes a plurality of stages 2a for performing welding assembly,
2b, 2c, 2d? 2e, 2f, 2g...
It consists of... A multi-spot welding machine 3 is installed on the stage 2a at the upstream end of the line 1 to assemble the engine conversion E by simultaneously spot-welding and temporarily joining a plurality of members at a plurality of points. 4 is a first supply line that joins the stage 2b, and the stage 4a of the first subline 4 includes a multi-spot welding machine 5 that assembles the front floor A by simultaneously spot-welding and temporarily welding a plurality of members at a plurality of points. is set up.

6 is a second sub-line that joins the stage 2b, and a multi-spot welding machine 7 is installed on the stage 6a of the second supply line 6, which assembles the rear floor R by simultaneously spot-welding and temporarily joining a plurality of members at a plurality of points. has been done.

The stage 2b is provided with an assembly pick means 8, and this assembly pick means 8 is equipped with an engine conversion E that has been preassembled by the multi-spot welding machines 3, 5, 7 on the stages 2a, 4a, 6a. , front floor A
, the rear floor R is carried in by three orderers (not shown), and is delivered in a mutually positioned state. A multi-spot welding machine 9 is installed in stage 2c, which is immediately next to stage 2b.
, the rear floors R are spot welded at least in the tunnel portion of the floors, and the engine conversion E, front floor A, and rear floor R are temporarily joined together. In the above explanation, temporary joining refers to a state in which only some welding points are melted, and in this state, the members will not separate from each other even if they are transported or the like. Stages 2d and 2e downstream from the multi-spot welding machine 9
, 2f, 2g..., a plurality of welding robots 10a, 10b, 10c, 10d..., respectively.
...... are installed, and these welding robots 103
, 1ob, 10c, 10d, . The plurality of welding robots 10a
, 10b, 10c, 10d, . . . constitute a welding robot group 11 as a whole. 21 is a continuous shuttle bar extending along line 1, and the upstream end of this shuttle bar 21 is connected to multi-spot welding machine 3.
and the assembly jig means 8, and its downstream end is located downstream of the most downstream welding robot. The shuttle bar 21 is composed of two parallel parts 22 and 23 that are spaced apart from each other by a predetermined distance in the vicinity of the assembling tool means 8 and the multi-spot welding machine 9, while the welding robots 10a,
10b, 10c, 10d.・・・・・・・・・Consists of one straight part 24 in the vicinity, parallel parts 22, 2
3 and the straight portion 24 are connected by a connecting portion 25 between the multi-spot welding machine 9 and the most upstream welding robot 10a. As shown in FIGS. 2 and 3, the assembly jig means 8 has a frame 34 installed on the floor surface 33 of the bit 32 parallel to the shuttle bar 21 formed on the floor surface 31. Parallel portions 22 and 23 of the shuttle bar 21 are movably supported at the upper end. A pair of vertical balance cylinders 35 are attached to the frame 34, and a lifting platform 37 is fixed to the tips of piston rods 36 of these balance cylinders 35. 38 is frame 3
The elevating table 37 is fixed to the tip of a piston rod 39 of this driving cylinder 38, and the elevating table 37 is raised and lowered by operating the driving cylinder 38.

The lifting platform 37 includes a pick-up member 40 for positioning and holding the engine conversion E, a jig member 41 for positioning and holding the front floor A, and a jig member 41 for positioning and holding the front floor A.
A jig member 42 for positioning and holding the engine conversion E is attached to these jigs 40, 41, 42.The front floor A and the rear floor R are attached to the front and rear ends of the front floor A. is positioned and held in a state overlapping with the rear end of the engine conversion E and the front end of the rear floor R. Each stage 2d, 2e, 2f, 2g... is provided with a lifter 51. Each lifter 51 has a frame 52 installed on the bottom surface 33 of the bit 32, and this frame 5
A linear portion 24 of the shuttle bar 21 is movably supported at the upper end of the shuttle bar 21. A pair of vertical balance cylinders 53 are attached to the frame 52, and a lifting platform 55 is attached to the tip of the piston rod 54 of these balance cylinders 52.
is fixed. Reference numeral 56 denotes a vertical drive cylinder attached to the frame 52. The elevating table 55 is fixed to the tip of a piston rod 57 of this driving cylinder 56, and when the driving cylinder 56 operates, the elevating table 55
A holder 58 is attached to support the floor F, which is assembled by temporarily joining the engine conversion E, the front floor A, and the rear floor R using the multi-spot welding machine 9, from below.

Note that 59 is a welding gun of the welding robot. Again, in FIG. 1, reciprocating means 61 for reciprocating the shuttle bar 21 in the longitudinal direction is installed on the floor 31 between the stages 2f and 2g. This reciprocating means 61
As shown in the figure, it has a base 62 fixed to the floor 31.
A motor 63 capable of forward and reverse rotation is mounted on the base 62. An output shaft 64 of the motor 63 and an input shaft 66 of a reduction gear 65 fixed on the base 62 are connected via a coupling 67. Output shaft 68 of reducer 65
A rotary shaft 70' rotatably supported by a pair of bearings 69 attached to the base 62 is connected via a coupling 71, and this continuous shaft 701 is connected to the shuttle bar 21.
A pinion 72 located directly below the straight portion 24 is fixed. A rack 73 that engages with a pinion 72 is fixed to the lower surface of the linear portion 24 of the shuttle bar 21, and this rack 73 is slightly longer than the distance between the stages. The rotational movement of the pinion 72 caused by the operation of the motor 63 is changed into linear movement by the rack 73. The multi-spot welding machine 9 has a machine frame 81 as shown in FIGS. , consisting of a pair of vertical posts 83 erected on lower bases 82 on both sides of the shuttle bar 21, and an upper base 84 attached to the upper end of the vertical posts 83 and located above the shuttle bar 21. A pair of support stands 85 and 86 are installed on the floor surface 31 on both sides of the lower base 82, that is, on both sides of the shuttle bar 21, and on the lower base 82 on the side of the support stand 85, a pair of support stands 85 and 86 are installed at a distance from each other. Support blocks 87 and 88 are attached. 91 and 92 are a pair of beams that are perpendicular to the shuttle bar 21 and parallel to each other, with one end connected to the support stand 85 and the other end connected to the support stand 86. , 92 are supported from below by support blocks 87 and 88, respectively.

A pair of rails 93' and 94 parallel to the beams 91 and 92 are provided inside the beams 91 and 92, and each rail 9
3,94 is connected to a support stand 85 at one end and a support stand 86 at the other end. The center portions of these rails 93 and 94 are also supported from below by support blocks 87 and 88, respectively. 95 is a movable table movable along the rails 93 and 94, and this movable table 95 is rotatably supported by a rectangular movable base 96 and the four corners of the lower surface of this movable base 96, and is mounted on the rails 93 and 94. rollers 97, 98 rolling on
and has.

For example, on the upper surface of this movable base 96, there is a floor F of a car type A.
A lower fixture 101 for
When assembling the car-shaped floor F, this lower fixture 101 is located directly below the shuttle bar 21. This lower fixture 101 has a support frame 102 mounted on a moving base 96, and on this support frame 102 are a plurality of pick-ups 103 that support the engine conversion E, front floor A, and rear floor R from below. is installed. Further, a pair of back electrodes 104 are installed on the support frame 102 for at least spot welding the engine conversion B, front floor A, and rear floor R to each other in the tunnel portion T, and these back electrodes 104 are connected to the shuttle. Parallel part 22 of bar 21,
It is located between 23. Note that 105 is a locate pin provided on the support frame 102 for positioning. 111
is a movable base different from the movable base 95 that is movable along rails 93 and 94 provided on the side of the movable base 95 (the right side in FIGS. 6 and 8), and this movable base 111 has a rectangular shape. It has a moving base 112, and rollers 113, 114 that are rotatably supported at the four corners of the lower surface of the moving base 112 and move on rails 93, 94.

On the upper surface of this moving base 112, a lower fixture 117, which is different from the lower fixture 101, is attached, for example, for the floor F of the B car type, and when assembling the B car type floor F, the lower fixture 117 is 101 and is located directly below the shuttle bar 21.
This lower fixture 117 includes a support frame 102 similar to the lower fixture 101, a support frame 103, a back electrode 1
04 and a locate pin 105 are provided, but since these have the same configuration except that the shape and position have been changed for the B car type, detailed explanation will be omitted. Brackets 121 and 12 are provided on the upper surfaces of the beams 91 and 92, respectively.
Guide plates 123, 124 are attached to the guide plates 123, 124 through the movable bases 96, 112, and sliders 125, 126 with low frictional resistance fixed to both sides of the movable bases 96, 112 are attached to the guide plates 123, 124. 96 and 112 are restricted from moving in the width direction. Connecting brackets 131 and 132 are attached to the end surface of the movable table 95 and one end surface of the movable table 111, respectively, and pins 133 and 1 are attached to each of the connecting brackets 131 and 132, respectively.
34 are inserted from below into pin holes 135 and 13, respectively.
6 is formed. The pins 133 and 134 are erected on a connecting block 137 provided between the moving tables 95 and 111, and are connected to the moving table 95 via this connecting block 137.
, 111 are connected to move together. Racks 140 and 141 are attached to the lower surface of both widthwise ends of the connecting block 137 via brackets 138 and 139, respectively, and the rack 140 extends parallel to the beam 91 between the beam 91 and the rule 93. extends parallel to beam 92 between beam 92 and rule 94 . Numerous rollers 142 and 143 are rotatably supported by the beam 91 and the rail 93, respectively, and these rollers 142 and 143 sandwich the rack 140 from above and below.

144 and 145 are beam 92 and rail 94, respectively.
These rollers 144 and 145 sandwich the rack 141 from above and below.

A motor 46 is attached to the upper surface of the lower base 82 on the support stand 86 side, and the output shaft 147 of this motor 146 is connected to the input shaft 1501 of a reducer 149 attached to the lower base 82 via a coupling 148. ing.
The output shaft 151 of the reducer 149 is rotatably supported at its tip by a bearing (not shown) fixed on the lower base 82. A rack 140 is attached to the output shaft 151.
, 141' are fixed, and when the motor 146 operates and the pinions 152 rotate, the movable platforms 95 and 111 move together along the rails 93 and 94. Dampers 1 are mounted on the support stands 85 and 86 via brackets 153 and 154, respectively.
55, 156 are fixed, and these dampers 155, 15
6 alleviates the collision when the movable platforms 95, 111 move to the left end or right end in FIG. 6 and collide. 161 is the rail 93, 94 below the shuttle bar 21.
This platen 16 is a rectangular platen that moves up and down between
1 includes a piston rod 164 of a pair of vertical balance cylinders 162 and 163 attached to a lower base 82.
, 165 are connected.

A drive cylinder 166 is vertically attached to the lower base 82 between the balance cylinders 162 and 163, and the tip of a piston rod 167 of the drive cylinder 166 is also connected to the platen 161. And the drive cylinder 16
6 is operated, the platen 161 moves up and down. The platen 161 is provided with a pair of positioning protrusions 168 protruding from its upper surface, and these protrusions 168 can be inserted into the holes 170' of a pair of bosses 169 attached to the lower surface of each moving platform 95, 111. It is. A pair of stopper means 181, 182 are provided on the lower base 82 between the balance cylinders 162, 163 and the drive cylinder 66.
are provided, and each stopper means 181, 182 has a ninth
As shown in FIG.
85 and 186 are swingably supported via pins 187 and 188. Reference numeral 189 is a rod having one end connected to the center of the swinging arm 185 and one end connected to the lower end of the swinging arm 186.
, 186 swing in synchronization.

Reference numeral 190 denotes a bracket erected on the lower base 82, and the rear end of the cylinder 191 is connected to the bracket 19.

The tip of the piston rod 192 of the cylinder 191 is connected to a swing arm 185, and when the cylinder 191 operates, the swing arms 185 and 186 swing. The brackets 183 and 184 have receiving surfaces 193 and 19, respectively.
4 is formed on each receiving surface 193, 194, when the swing arms 185, 186 are upright, the swing arms 185, 18
The lower end surface of 6 comes into contact. In this way, the swinging arm 185,
When the platen 186 is upright, the lower surface of the platen 161 is aligned with the swinging arms 185, 1 as shown by the imaginary line in FIG.
86, and determines the lowering limit of the platen 161 during normal operation. 6, 7, and 11, support plates 201 parallel to the rails 93 and 94 are fixed to both end surfaces of the upper base 84, and a large number of rollers 20 are respectively fixed to the opposing surfaces of these support plates 201.
2 is rotatably supported. Reference numeral 203 denotes a moving table, and both end portions of this moving table 203 are supported by the rollers 202 from below, and the moving table 203 is supported by the rollers 202.
It is movable perpendicularly to the shuttle bar 21 while being supported by the shuttle bar 21.

For example, an upper fixture 204 for the floor F of the A car type is attached to the lower surface of the moving table 203, and the moving table 203 is positioned directly above the shuttle bar 21 when the floor F of the A car type is being set up. . This upper fixture 204 is a support frame 2 attached to the lower surface of the moving table 203.
05, and this support frame 205 has the back electrode 10
A pair of spot gun groups 206 corresponding to No. 4 are installed,
Each spot gun group 206 is composed of a plurality of spot guns 207. Each spot gun group 206 is located directly above the back electrode 104, and
In collaboration with 4. At least the tunnel portion T of A F is spot welded at multiple points, and the engine conversion E, front floor A, and rear floor R are temporarily joined together. The above-mentioned lower fixture 101 and upper fixture 204 are, as a whole, of the A vehicle type in which the engine conversion E, the front floor A, and the rear floor R of the A vehicle type are spot welded at least at the tunnel portion T to temporarily join these members together. A fixture 208 is configured. Reference numeral 211 denotes a movable base separate from the movable base 203, which is provided on the side of the movable base 203, on the left side in FIG. Supported by.

Therefore, the moving table 211 can move perpendicularly to the shuttle bar 21. An upper fixture 212 for the floor F of car B type, for example, which is separate from the upper fixture 204, is attached to the lower surface of this moving platform 211. When assembling the floor F of car B type, the upper fixture 204 and is located directly above the shuttle bar 21. This upper fixture 212 is the same as the upper fixture 204 except that the shape and position have been changed from the one for vehicle type A to the one for vehicle type B, so a detailed explanation will be omitted. The above-mentioned lower fixture 117 and upper fixture 212 are for the B car type as a whole, where the engine conversion E, front floor A, and rear floor R of the B car type are spot welded at least in the tunnel part T to temporarily join these parts. A fixture 213 is configured. Connection brackets 231 and 2 are provided on opposing sides of the movable platforms 203 and 211, respectively.
32 are formed, and these connecting brackets 231, 23
2 are formed with pin holes 235 and 236 into which pins 233 and 234 are inserted from below, respectively. Said pin 2
33 and 234 are erected on a connecting block 237 provided between the movable tables 203 and 211, and this connecting block 23
The movable tables 203 and 211 are connected via 7 so that they can move together. Rotating shafts 238 and 239 are rotatably supported at both ends of the support plate 201, and sprocket wheels 240 and 241 are fixed to these rotating shafts 238 and 239, respectively. Reference numeral 242 denotes a chain with ends that is stretched between the sprocket wheels 240 and 241, and both ends of the chain 242 are connected to the connection block 237.

243 is a motor fixed on the upper base 84;
The output shaft 244 of this motor 243 is connected to a coupling 245
It is connected to an input shaft 247 of a reduction gear 246 fixed on the upper base 84 via.

A sprocket wheel 249 is fixed to the output shaft 248 of the reducer 246, and this sprocket wheel 249 and the sprocket wheel 2 fixed to the rotating shaft 238
An endless chain 250 is strung between it and 40. Then, the motor 243 operates and the chain 250,
As 242 travels, the movable platforms 203 and 211 move together. 251, 252 are support plates 20
These dampers 251 and 252 reduce the impact when the movable platforms 203 and 211 move to the left end or right end in FIG. 11 and collide.

A bracket 261 is attached to the upper base 84, and a vertical locking cylinder 2 is attached to the bracket 261.
62 is fixed. A lock pin 264 is fixed to the tip of the piston rod 263 of the cylinder 262, and this lock pin 264 is inserted into a lock hole 265 formed in each of the movable bases 203 and 211 to position and lock the movable bases 203 and 211. do. 6th, 7th, 1st
In FIG. 2, beams 271 parallel to the shuttle bar 21 are fixed on both sides of the shuttle bar 21 between intermediate portions of the vertical posts 83, and a bracket 272 is attached to each beam 271. As shown in detail in FIG. 2, a swing arm 273 is swingably supported on each bracket 272 via a pin 274. 275 is each bracket 272
A piston of this cylinder 275.

The tip of the rod 276 is connected to the upper end of the swing arm 273. A roller 277 is rotatably supported at the lower end of the swing arm 273, and this roller 277 is attached to the movable table 95.
, 111, T-shaped claws 2 attached to both ends of each
It can be caught on the locking part 279 of 78 from below. The aforementioned cylinder 275, swing arm 273, and roller 277 collectively constitute a positioning means 280 that positions the movable platform 95, 111 at its upper limit. The explanation so far has been about multi-spot welding machine 9,
Since the multi-spot welding machines 3, 5, and 7 also have the same configuration as the multi-spot welding machine 9, detailed explanation will be omitted. Also, a known welding robot is used to perform the additional welding, and its control is switched depending on the vehicle type. Next, the effect will be explained. Here, the assembly of one floor F for vehicle type A will be explained in order, but in reality, a large number of floors F are assembled at the same time.

First, in stage 2a, a plurality of members are simultaneously spot welded and temporarily joined at a plurality of points by a multi-spot welding machine 3, and the engine conversion E
is assembled. At the same time, in stages 4a and 6a, a plurality of sections are simultaneously spot welded and temporarily joined together at a plurality of points using multi-spot welding machines 5 and 7.The front floor A and the rear floor R are assembled. These pre-assembled engine conversion E, front floor A and rear floor R are transported to stage 2M by a loader. That is, "First, the front floor A is transported by the loader to the lining member 41 of the roughening jig means 8, and then transferred to the pick-up member 41. At this time, the front floor A is positioned by the jig member 41. Next, the engine conversion E and the rear floor R are transported by the loader to the jig member 40742 of the assembly pick-up means 8.
0 and 42, respectively. At this time, the rear end of engine conversion E and the front end of rear floor R are overlapped with the front and rear ends of front floor A.
are positioned and held by jig members 40 and 42. At this time, the shuttle bar 21 is located at the backward limit. Next, the loader separates from the assembly pick-up means 8 and returns to the standby position. Next, the drive cylinder 38 of the assembly jig means 8 is actuated and its piston rod 39 is retracted. As a result, the engine compartment E, the front floor A, and the rear floor R held by the jig members 40, 41, and 42, respectively, descend until they come into contact with the upper surface of the shuttle bar 21. Next, the jig members 40, 41, and 42 release the engine compartment E, front floor A, and rear floor R from being held. As a result, the engine compartment E, front floor A, and rear floor R are assembled into jig members 40 and 41.
, 42 to the shuttle bar 21, and is placed on the shuttle bar 21. Next, the motor 63 of the reciprocating means 61 is activated, and its output shaft 64 rotates. The rotation of the power shaft 64 is controlled by the coupling 67, the input shaft 66, and the reducer 6.
5. The output signal is transmitted to the pinion 72 via the output ball 68, the coupling 71, and the rotating shaft 70, causing the pinion 72 to rotate.
This rotational movement of the pinion 72 is converted into linear movement by the rack 73, thereby moving the shuttle bar 21 forward. When the engine conversion E, front floor A, and rear floor R on the shuttle bar 21 are transported to the next stage 2c and reach between the upper and lower fixtures 204 and 101, the shuttle bar 21 stops moving forward. At this time,
The multi-spot welding machine 9 has movable tables 203 and 95 located directly above and below the shuttle bar 21. Also, at this time, the piston rod 16 of the drive cylinder 166
7 protrudes slightly, and the projection 168 is inserted into the hole 1 of the boss 169.
70 respectively inserted into the movable table 95.
is supported from below by the platen 161 in a slightly raised state. Therefore, the pin 133 has come out from the pin hole 135 of the moving table 95. Also, at this time, the swinging arm 185 of each stopper means 181, 182
, 186 stands upright, and its lower end surface is connected to the bracket 183, 1.
While being in contact with the receiving surfaces 193 and 194 of 84,
Its upper end surface is in contact with the lower surface of the platen 161. Therefore, the weight of the moving table 95 and the lower fixture 101 is transferred to the bracket 183 and
184, and the downward movement of the movable table 95 is restricted. Next, the drive cylinder 16
6 is activated and its piston rod 167 protrudes. Therefore, the platen 161 rises while lifting the movable table 95 and the lower fixture 101. When the lower fixture 101 reaches a position where it can support the engine conversion E, front floor A, and rear floor R mounted on the shuttle bar 21 from below, the engine conversion E, front floor A, and rear floor R are mounted on the shuttle bar 21. It is delivered from the bar 21 to the lower fixture 101. In this state, the piston rod 167 of the drive cylinder 166 protrudes to near the stroke end. Next, the cylinder 275 of the positioning means 280 is activated and its piston rod 276 is retracted. As a result, the swinging arm 273 swings, and the roller 277 moves to the claw 2 of the movable table 95.
It is caught on the locking part 279 of 78 from below. As a result,
The movable table 95 is positioned and locked at the upper limit as shown by the imaginary line in FIG. At this time, spot gun group 20
At least the tunnel portion T of the engine conversion E, front floor A, and rear floor R is sandwiched between the spot gun 207 of No. 6 and the back electrode 104, and the engine conversion E, the front floor A, and the rear floor R are energized. The R's are temporarily joined by spot welding at least in the tunnel portion T to form the floor F. At this time, since the shuttle bar 21 is arranged so that its parallel portions 22 and 23 sandwich the back electrode 104 as described above, it does not hinder the elevation and descent of the back electrode 104 in any way. Note that in this embodiment, the lower fixture 1
01 has the back electrode 104, but if the lower fixture 101 has a plurality of spot guns, the shuttle bar 21 has two parallel parts 2.
2 and 23, it becomes easy to determine the placement of the spot gun. At this time, the reciprocating means 61 is activated and the shuttle bar 21 is returned to the backward limit. In this way, when the engine compartment E, the front floor A, and the rear floor R are temporarily joined at least in the tunnel portion T to form the floor F, each spot gun 207 of the spot gun group 206 is moved back and positioned. The cylinder 275 of the means 280 is actuated and its piston rod 276 protrudes. As a result, the roller 277 is disengaged from the locking portion 279 of the claw 278. Drive cylinder 166 is then activated and its piston rod 167 is retracted. As a result, the platen 161 descends until its lower surface abuts the upper end surfaces of the swing arms 185 and 186. During this descent, the lower fixture 101
Floor F, which was supported from below, is supported by the shuttle bar 21.
transfer to. At the same time, the engine conversion E, front floor A, and rear floor R, which will be temporarily joined next, are loaded in the same manner as described above. Next, the motor 63 of the reciprocating means 61 is activated, and the shuttle bar 21 moves forward. As the shuttle bar 21 moves forward, the floor F is transported to the stage 2d. Next, the drive cylinder 56 of the lifter 51 is actuated and its piston rod 57 protrudes. As a result, the holder 68 receives the floor F from the shuttle bar 21 while rising, and lifts the floor F to the welding position. Next, the welding robot 10a applies additional welding points to the welding points that were not welded by the multi-spot welding machine 9.
At this time, there is a shuttle bar 21 between the welding robots 10a.
Since the straight part 24 of the welding robot 10a is
The movement of the welding robot 10a can be easily controlled. Also, at this time, shuttle bar 2
1 moves backward to the backward limit. Next, the reciprocating movement of the shuttle bar 21 as described above, the operation of the lifter 51, and the welding robots 10b, 10c, 10d......
As a result of the operation, the floor F is added one after another in stages 2e, 2f, 2g, etc., and the engine conversion E, front floor A, and rear floor R are completely joined to each other, and the floor F is completed. The floor F, which has been assembled in this way, is transported to the body assembly line by an overhead conveyor. Now, A
When changing the assembly of the floor F of the car type to the assembly of the floor F of the B car type, the procedure is as follows.

Here, only the operation in the multi-spot welding machine 9 will be explained, but the same operation is performed in the multi-spot welding machines 3, 5, and 7 as well. First, each stopper means 18
1,182 cylinder 191 is actuated to project its piston rod 192, swinging the swinging arms 185, 186 from the upright position to the position shown in FIG. next,
Actuate the drive cylinder 166 to move its piston rod 16
7 to the stroke end. Therefore, the platen 161 is lowered from the position shown by the imaginary line in FIG. 10 to the position shown by the solid line. During the descent of the platen 161, the rollers 97 and 98 of the moving table 95 move onto the rail 9.
3 and 94, the movable table 95 transfers from the platen 161 to the rollers 93 and 94. At this time, the pin 133 is inserted into the pin hole 135 of the connecting bracket 131 of the moving table 95, and the moving table 95 and the moving table 111 are connected to the connecting block 1.
37. On the other hand, cylinder IJ cylinder 262 is also activated and its piston rod 263 is retracted. As a result, the lock pin 264 is pulled out from the lock hole 265 of the movable base 203, and the movable bases 203 and 211 become movable. Next, the motor 146 is operated and its output is 1.
Rotate 47. This rotation of the output shaft 147 causes the pinion 152 to rotate, and the rotational movement of the pinion 152 is converted into linear movement by the racks 140 and 141. As a result, the movable tables 95 and 111 are integrated into the rail 9.
3, 94 to the left in FIG. At the same time, the motor 243 also operates to rotate its output shaft 244. Chain 242 due to rotation of output shaft 244
The moving tables 203 and 211 move together to the right in FIG. 6 while being supported by the rollers 202 from below. When the moving platforms 95, 111 move to the left end, the motor 146 stops operating. At this time, the movable table 95 hits the damper 155, and the impact caused by the stoppage of the movable table 95 is alleviated. Also, at this time, the moving platform 111 is located directly below the shuttle bar 21, and the lower fixture 1 for the A car type is positioned directly below the shuttle bar 21.
01 to the lower fixture 117 for the B car type. On the other hand, when the movable tables 203, 211 move to the right end, the operation of the motor 243 is stopped. At this time, moving platform 2
03 hits the damper 252, and the impact caused by the stoppage of movement is alleviated. Further, at this time, the movable table 211 is located directly above the shuttle bar 21, and the upper fixture 204 for the A car type is switched to the upper fixture 212 for the B car type. Next, the drive cylinder 166 is actuated to cause its piston rod 167 to protrude slightly. As a result, the movable table 111 moves from the platen 16 from the seals 93 and 94.
1 and then raised to a predetermined position while being lifted by the platen 161. At this time, the pin 134 comes out of the pin hole 136 of the connection bracket 132. Next, the stopper means 181 and 182 are actuated so that the swing arm 18
5,186 is made to stand upright, and its upper end surface is brought into contact with the lower surface of the platen 161. Meanwhile, the cylinder 262 also operates, inserting the lock pin 264 into the lock hole of the moving table 211, and positioning and locking the moving table 211. Since such switching takes place in a short time, line A can be switched without stopping line 1 at all.
, B car type can be produced in parallel. Note that the operation after switching the fixture for the B car type is exactly the same as the operation in assembling the floor F for the A car type, so a detailed explanation will be omitted. In the above-mentioned embodiment, a case has been described in which one other fixture 213 is provided on the side of the fixture 208, but in the present invention, two or more other fixtures may be provided. For example, when two fixtures are provided, one fixture may be provided on one side of the fixture, and the other fixture may be provided on the other side of the fixture. As explained above, according to the present invention, the multi-spot welding machine and the welding robot group are arranged separately on the line, and another fixture is arranged on the side of the multi-spot welding machine so as to be connected at least during replacement. Because of this, model changes can be quickly handled by simply changing the control of the Ruto robot group and replacing the fixture of the multi-spot welding machine. Furthermore, only the fixtures of the previous model need to be discarded, which is preferable from the standpoint of capital investment and resource savings. In addition, even when parallel production is performed on one line, it can be quickly handled by simply switching the control of the welding robot group and switching the fixtures.

[Brief explanation of the drawing]

Fig. 1 is a schematic plan view showing one embodiment of the present invention, Fig. 2 is a plan view of the vicinity of the multi-spot welding machine, Fig. 3 is a view taken from the direction of the m-plate arrow in Fig. 2, and Fig. 4 is a plan view of the vicinity of the multi-spot welding machine. 5 is a plan view of the reciprocating means; FIG. 5 is a view taken along the V-V arrow in FIG. 4; FIG. Sectional view, No. 8
The figure is a partially cutaway front view of the vicinity of the lower fixture, Figure 9 is a sectional view taken along arrow K-K in Figure 8, and Figure 10 is a cross-sectional view taken along line X-X in Figure 9.
11 is a partially cutaway front view of the vicinity of the upper fixture, and FIG. 12 is a front view of the positioning means. E...Engine conversion, A...Front floor, R...Rear floor, T...Tunnel section, F...
...Floor, 1...Line, 9...
Multi-spot welding machine, 10a, 10b, 10c, 10
d... Welding robot, 11... Welding robot group, 208... Fixture, 213... Another fixture. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 2 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11

Claims (1)

[Claims] 1. A multi-spot welding machine is installed on the line to spot-weld the pre-assembled engine compartment, front floor, and rear floor together at least in the tunnel section to temporarily join these parts together, and the welding process using the multi-spot welding machine is A group of welding robots consisting of a plurality of welding robots for increasing welding points that have not been welded is installed on the line downstream from the multi-spot welding machine, and a fixture different from the fixture of the multi-spot welding machine is used at least when replacing the welding robot. Connect it to the fixture of the multi-spot welding machine and place it on the side of the multi-spot welding machine, and use it as appropriate depending on the type of floor.
An automobile floor assembly line characterized by the ability to replace fixtures.