Vehicle assembling-and-feeding system

A vehicle assembling-and-feeding system comprises an engine/suspension feeding line which travels through an engine assembly line and a first suspension assembly line for assembling one of front and rear suspensions to feed the engine and said one suspension, a suspension feeding line which travels through a second suspension assembly line for assembling the other suspension to feed the suspension, a body feeding line for feeding a vehicle body in indexed feed fashion, a slippage detecting station which is provided midway along the body feeding means to detect slippage in the position of the vehicle body fed by the body feeding means in indexed feed fashion, a mounting station disposed downstream of the slippage detecting station, and a mingling feed line which alternately feeds to the mounting station the material fed by the engine/suspension feeding means and the material fed by the suspension feeding means. An automatic mounting device is provided at the mounting station. The automatic mounting device has a pair of mounting tables which are three-dimensionally movable, one being adapted to receive the engine and said one suspension and the other being adapted to receive said other suspension. The automatic mounting device is controlled to compensate for the slippage of the position of the vehicle body detected at the slippage detecting station.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a vehicle assembling-and-feeding system. 
2. Description of the Prior Art 
Generally, there has been used in assembly of vehicles an 
assembling-and-feeding system in which various components are assembled on 
assembly lines and fed to a mounting station and mounted, at the mounting 
station, on a vehicle body which is fed thereto while being supported by a 
hanger. 
For example, in the vehicle assembling-and-feeding system disclosed in 
Japanese unexamined patent publication No. 60(1985)-56682, each vehicle 
body fed by a continuous feed conveyor is transferred to an indexed feed 
conveyor, while an engine on an assembly line is fed to a mounting table 
of a mounting device by a conveyor, and when the body fed in indexed feed 
fashion is stopped, the mounting table is moved upward and the engine is 
mounted on the body. Thereafter, the body equipped with the engine is 
transferred to a continuous feed conveyor. Thus, synchronization of the 
conveyors is facilitated, and the operator's mounting operation is 
facilitated. 
However, in the conventional assembling-and-feeding system, mounting of the 
engine is effected in a semi-automatic mode and slip in the position of 
the body must be corrected by the operator. Accordingly, the mounting 
operation is still complicated. Further, in order to mount the engine and 
one of the front suspension and the rear suspension at a single mounting 
station for assembly efficiency, many operators are required. 
SUMMARY OF THE INVENTION 
In view of the foregoing observations and description, the primary object 
of the present invention is to provide a vehicle assembling-and-feeding 
system in which the engine and one of the front and rear suspensions can 
be mounted on the body at a single mounting station with a high 
efficiency. 
The vehicle assembling-and-feeding system in accordance with the present 
invention comprises an engine/suspension feeding means which travels 
through an engine assembly line and a first suspension assembly line for 
assembling one of front and rear suspensions to feed the engine and said 
one suspension, a suspension feeding means which travels through a second 
suspension assembly line for assembling the other suspension to feed the 
suspension, a body feeding means for feeding a vehicle body in indexed 
feed fashion, a slippage detecting station which is provided midway along 
the body feeding means to detect slippage in the position of the vehicle 
body fed by the body feeding means in indexed feed fashion, a mounting 
station disposed downstream of the slippage detecting station, a mingling 
feed means which alternately feeds to the mounting station the material 
fed by the engine/suspension feeding means and the material fed by the 
suspension feeding means, an automatic mounting means which is provided at 
the mounting station and has a pair of mounting tables which are 
three-dimensionally movable, one being adapted to receive the engine and 
said one suspension and the other being adapted to receive said other 
suspension, and a compensating means which controls the automatic mounting 
means to compensate for the slippage in the position of the vehicle body 
detected at the slippage detecting station.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIGS. 1 to 12 show a vehicle assembling-and-feeding system in accordance 
with an embodiment of the present invention applied to the assembly of 
front-engine front-drive type vehicles. An engine assembly area 1 is 
provided with an engine dress-up line 2 which comes from the engine 
assembly area 1 and returns thereto. An engine hanging station 3 is 
disposed midway along the engine dress-up line 2. An engine/suspension 
feeding line 4 comprising an overhead conveyor passes over the engine 
hanging station 3. The engine/suspension feeding line 4 further passes 
over a perimeter rame mounting station 5 and a front-suspension assembly 
line 6. A suspension feeding line 8 comprising an overhead conveyor passes 
over a rear-suspension assembly line 7. 
A body continuous-feed line 9 comprises an overhead conveyor which feeds 
vehicle bodies 21 continuously. A body indexed-feed line 10 branches off 
from the body continuous-feed line 9. The body indexed-feed line 10 also 
comprises an overhead conveyor. Below the body indexed-feed line 10 is 
disposed a mounting station 13 having a pair of automatic mounting devices 
12 and a slippage detecting station 11. The engine/suspension feeding line 
4 and the suspension feeding line 8 are merged into a mingling feed line 
14 at a junction station 14a. To the mingling feed line 14 are alternately 
fed the parts from the engine/suspension feeding line 4 and the suspension 
feeding line 8 at the junction station 14a. The mingling feed line 14 
passes over the mounting station 13 and branches out into the 
engine/suspension feeding line 4 and suspension feeding line 8 at a 
separation station 14b downstream of the mounting station 13. 
The conveyor of the body indexed-feed line 10 comprises a rack-and-pinion 
mechanism 15 having a rack 16 and a pinion 19. A plurality of hanger 
holders 18 for releasably holding a hanger 17 for suspending the vehicle 
body 21 are fixed to the rack 16. The pinion 19 is driven by a driving 
motor 20 to feed the body 21 suspended by the hanger 17 in indices of a 
pitch determined by the rack 16. 
As shown in FIG. 6, the hanger holder 18 comprises a pair of opposed claws 
18a and 18b. The claws 18a and 18b are supported for rotation at an 
intermediate portion and are spring-urged away from each other, that is, 
the first claw 18c is urged counterclockwisely and the second claw 18b is 
urged clockwisely as seen in FIG. 6. Counterclockwise rotation of the 
first claw 18a and the clockwise rotation of the second claw 18b are 
limited by a downward projection 18b. When the hanger 17 approaches the 
parting of the lines, the first claw or the upstream side claw 18a is 
clockwisely rotated or brought down, overcoming the force of the spring by 
suitable means, and the hanger 17 is forced to override the first claw 18a 
by a feeder 10a. The hanger 17 is trapped between the claws 18a and 18b to 
be carried thereby. When the hanger 17 is returned to the body 
continuous-feed line 9, the second claw or the downstream side claw 18b is 
brought down, overcoming the force of the spring by suitable means, and 
the hanger is forced to override the second claw 18b by a feeder which is 
similar to the feeder 10a though not shown. On the inner surface of the 
second claw 18b is formed a cam surface so that the hanger 17 is not 
trapped between the second claw 18b and the projection 18c when the second 
claw 18b is brought down. 
In the slippage detecting station 11, four visual sensors 22 are provided, 
two on the front side and the other two on the rear side, to detect 
slippage of the position of the vehicle body 21 from the regular position 
when the body 21 is stopped at the slippage detecting station 11. 
Front and rear transfer devices 23 are provided at the mounting station 13. 
Each transfer device 23 comprises an upper conveyor 24a and a lower 
conveyor 24b. The upper and lower conveyors 24a and 24b may be of a 
rack-and-pinion mechanism or a lift-and-carry mechanism. A lifter 25 is 
disposed on one end of the conveyors 24a and 24b below the mingling feed 
line 14. The lifter 25 is movable up and down between a part-receiving 
position designated by A in FIG. 4, an upper conveyor position (designated 
by B) at the level of the upper conveyor 24a and a lower conveyor position 
(designated by C) at the level of the lower conveyor 24b. Another lifter 
26 is disposed on the other end of the conveyors 24a and 24b to be movable 
between an upper conveyor position (designated by D) at the level of the 
upper conveyor 24a and a lower conveyor position (designated by E) at the 
level of the lower conveyor 24b. 
Said automatic mounting devices 12 are disposed on the other ends of the 
respective transfer devices 23. As shown in FIGS. 7 to 11, each automatic 
mounting device 12 comprises a lift mechanism 101 for moving up and down 
an engine assembly EA (though one of the mounting devices 12 is for 
mounting the engine assembly EA and the other is for mounting the rear 
suspension, they are substantially the same in structure, and accordingly 
description will be made of the mounting device 12 for mounting the engine 
assembly EA, by way of example), a first slide mechanism 102 for sliding 
the engine assembly EA placed on a pallet 109 in a horizontal plane back 
and forth in the transverse direction of the vehicle body 1, a second 
slide mechanism 103 for sliding the engine assembly EA in a horizontal 
plane in the longitudinal direction of the vehicle body 1 or in the 
vehicle body feeding direction, and a rotating mechanism 104 for rotating 
the engine assembly EA in a horizontal plane. 
As best shown in FIG. 8, the lift mechanism 101 includes a stationary post 
116 fixedly mounted on a base 115, and an up-and-down post 117 
telescopically received in the stationary post 116. The up-and-down post 
117 is provided with a top plate 118 on the upper end thereof, and is 
connected to a hydraulic cylinder 110 by way of a connecting pin 119 to be 
driven up and down by the cylinder 110. 
The first slide mechanism 102 comprises a base plate 105 fixedly mounted on 
the top plate 118 of the lift mechanism 101, and a first slide plate 106 
disposed above the base plate 105 to be opposed thereto. A pair of guide 
bars 121 are provided on the upper surface of the base plate 105 spaced 
from each other in the longitudinal direction of the vehicle body, and two 
pairs of guide receivers 135 are provided on the lower surface of the 
first slide plate 106 spaced from each other in the transverse direction 
of the vehicle body. The guide receivers 135 in each pair are spaced from 
each other in the longitudinal direction of the vehicle body. Each guide 
receiver 135 has a receiving groove 135a and each of the guide bars 121 is 
slidably received in the receiving grooves 135a of the guide receivers 135 
aligned with each other in the transverse direction of the vehicle body so 
that the first slide plate 106 is slidable relative to the base plate 105 
in the transverse direction of the vehicle body. A rack 139 is provided on 
the lower surface of the first slide plate 106 and a pinion 127 is in mesh 
with the rack 139. The pinion 127 is connected to a driving motor 125 by 
way of a clutch mechanism 126. When the pinion 127 is rotated by the 
driving motor 125, the first slide plate 106 is slid relative to the base 
plate 105. By the clutch mechanism 126, operational mode of the first 
slide mechanism 102 is switched between an automatic operation mode and a 
manual operation mode. That is, when the clutch mechanism 126 is engaged, 
the pinion 127 is directly connected to the driving motor 125 to be driven 
by the motor 125. On the other hand, when the clutch mechanism 126 is 
released, the pinion 127 is disconnected from the driving motor 125, and 
accordingly the first slide plate 106 can be manually moved relative to 
the base plate 105. 
A pair of origin indexing cylinders 122 are provided on the base plate 105, 
one directed forward with respect to the sliding direction of the first 
sliding plate 106 and the other directed rearward with respect to the 
sliding direction of the same. Forward and rearward stops 146 are provided 
on the first slide plate 106 to abut against abutment pieces 123 on the 
free ends of the respective origin indexing cylinders 122 when the origin 
indexing cylinders 122 are extended. That is, prior to mounting operation, 
the origin indexing cylinders 122 are extended until the abutment pieces 
123 abut against the stops 146, whereby an origin or a reference position 
with respect to the transverse direction of the vehicle body is indexed. 
The first slide mechanism 102 is controlled with respect to the origin or 
the reference position. It is confirmed by a limit switch 130 on the base 
plate 105 and a limit guide 140 on the lower surface of the first guide 
plate 106 whether the origin is precisely indexed. 
The second slide mechanism 103, as shown in FIGS. 8, 10 and 11, comprises 
the first slide plate 106 and a second slide plate 107 disposed above the 
first slide plate 106 to be opposed thereto. A pair of guide bars 165 are 
provided on the lower surface of the second slide plate 107 spaced from 
each other in the transverse direction of the vehicle body, and two pairs 
of guide receivers 136 are provided on the upper surface of the first 
slide plate 106 spaced from each other in the longitudinal direction of 
the vehicle body. The guide receivers 136 in each pair are spaced from 
each other in the transverse direction of the vehicle body. Each guide 
receiver 136 has a receiving groove 136a and each of the guide bars 165 is 
slidably received in the receiving grooves 136a of the guide receivers 136 
aligned with each other in the longitudinal direction of the vehicle body 
so that the second slide plate 107 is slidable relative to the first slide 
plate 106 in the longitudinal direction of the vehicle body. A rack 160 is 
provided on the lower surface of the second slide plate 107 and a pinion 
145 is in mesh with the rack 160. The pinion 145 is connected to a driving 
motor 143 by way of a clutch mechanism 144. When the pinion 145 is rotated 
by the driving motor 143, the second slide plate 107 is slid relative to 
the first slide plate 106. By the clutch mechanism 144, operational mode 
of the second slide mechanism 103 is switched between an automatic 
operation mode and a manual operation mode. That is, when the clutch 
mechanism 144 is engaged, the pinion 145 is directly connected to the 
driving motor 143 to be driven by the motor 143. On the other hand, when 
the clutch mechanism 144 is released, the pinion 145 is disconnected from 
the driving motor 143, and accordingly the second slide plate 107 can be 
manually moved relative to the first slide plate 106. 
A pair of origin indexing cylinders 137 are provided on the first slide 
plate 106, one directed forward with respect to the sliding direction of 
the second sliding plate 107 and the other directed rearward with respect 
to the sliding direction of the same. Forward and rearward stops 162 are 
provided on the second slide plate 107 to abut against abutment pieces 138 
on the free ends of the respective origin indexing cylinders 137 when the 
origin indexing cylinders 137 are extended. That is, prior to mounting 
operation, the origin indexing cylinders 137 are extended until the 
abutment pieces 138 abut against the stops 162, whereby an origin or a 
reference position with respect to the longitudinal direction of the 
vehicle body is indexed. The second slide mechanism 103 is controlled with 
respect to the origin or the reference position. It is confirmed by a 
limit switch 141 on the first slide plate 106 and a limit guide 161 on the 
lower surface of the second guide plate 107 whether the origin is 
precisely indexed. 
The rotating mechanism 104 comprises, as shown in FIGS. 8 and 11, the 
second slide plate 107 and a rotary table 108 disposed above the second 
slide plate 107 to be opposed thereto. The second slide plate 107 and the 
rotary table 108 are horizontally located with respect to each other by 
rotatably inserting a rotational shaft 56 mounted on the second slide 
plate 107 to project upward substantially at the center of the second 
slide plate 107 into a bearing portion 59 provided on the rotary table 108 
substantially at the center thereof. Further, the rotary table 108 is 
vertically located with respect to the second slide plate 107 by seven 
support rollers 155 mounted on the second slide plate 107 to abut against 
the lower surface of the rotary table 108 for rolling motion. On the 
bearing portion 159 on the rotary table 108 is mounted a large diameter 
wheel 167, and on an electric motor 157 is mounted a small diameter wheel 
168. A belt 158 is passed around the large diameter wheel 167 and the 
small diameter wheel 168 so that the rotary table 108 is rotated in a 
horizontal plane by the motor 157. The small diameter wheel 167 is 
connected to the electric motor 157 by way of a clutch 166 so that when 
the clutch 166 is disengaged, the rotary table 108 can be freely rotated 
separate from the motor 157. 
A limit switch 163 is provided on the second slide plate and a limit guide 
164 is provided on the rotary table 108. A reference position with respect 
to the angular position of the rotary table 108 relative to the second 
slide plate 107 is defined as the position when the limit guide 164 is 
engaged with the limit switch 163. 
On the rotary table 108 is placed the pallet 109 on which the engine 
assembly EA is placed. Though not shown, the rotary table 108 is provided 
with a locating device for fixing the pallet 109 to the rotary table 108 
in a predetermined position. Further, the pallet 109 is provided with a 
locating device (not shown) for fixing the engine assembly EA to the 
pallet 109 in a predetermined position. Four nut runners 111 for clamping 
the engine assembly EA to the vehicle body are disposed along the 
peripheral edge of the rotary table 108. 
Operation of the mounting device 12 will be described hereinbelow. The 
engine assembly EA on the pallet 109 is delivered to the mounting device 
12 from the transfer device 23 and placed on the rotary table 108 with the 
slide plates 106 and 107 and the rotary plate 108 in the respective 
reference positions. When the vehicle body 21 is stopped at the mounting 
station 11, the hydraulic cylinder 110 and the driving motors 125, 143 and 
157 are operated under the control of a controller (to be described in 
detail later) according to a predetermined control program to move the 
slide plates 106 and 107 and the rotary table 108 to position the engine 
assembly EA in place with respect to the vehicle body without interference 
with parts which have been mounted on the vehicle body 21. In this 
conjunction, the controller corrects the control program according to the 
slippage in the position of the vehicle body detected in the slippage 
detecting station 11 so that the engine assembly EA can be positioned in 
place with respect to the vehicle body 21 even if the vehicle body 21 has 
slipped from a predetermined position. After the engine assembly EA is 
positioned in place with respect to the vehicle body 21, the nut runners 
111 are operated to screw nuts on mounting bolts which have been provided 
on the vehicle body 21, thereby fixing the engine assembly EA on the 
vehicle body 21. After the engine assembly EA is thus mounted on the 
vehicle body 21, the slide plates 106 and 107 and the rotary tables 108 
are returned to the original position. 
In the case of failure of the electric system, the slide plates 106 and 107 
and the rotary table 108 can be manually controlled by disengaging the 
clutches 126, 144 and 166 and switching the hydraulic control circuit of 
the hydraulic cylinder to a manual control circuit. Accordingly, the 
engine mounting operation can be continued even if the electric system 
fails. 
Now, operation of the vehicle assembling-and-feeding system of this 
embodiment will be described. When the engine 36 is assembled in the 
engine assembly line 1, the engine 36 is transferred to the dress-up line 
2 to be dressed up. When the dressed-up engine 36 is fed to the engine 
hanging station 3, the engine 36 is transferred to the engine/suspension 
feeding line 4 to be fed along the engine/suspension feeding line 4 in a 
suspended state. While the engine 36 is fed along the engine/suspension 
feeding line 4, a perimeter frame 38 is mounted on the engine 36 at the 
perimeter frame mounting station 5, and a front suspension 37 assembled in 
the front-suspension assembly line 6 is mounted on the engine 36 when the 
engine 36 is passed over the front-suspension assembly line 6. In this 
particular embodiment, the engine 36, the perimeter frame 38 and the front 
suspension 37 form said engine assembly EA. The engine assembly EA is 
further fed to the junction station 14a of the mingling feed line 14. A 
rear suspension assembled in the rear-suspension assembly line 7 is fed 
along the suspension feed line 8 to the junction station 14a. The engine 
assembly EA and the rear suspension are alternately transferred to the 
mingling feed line 14 in this order and fed to the mounting station 13. 
At the same time, the vehicle body 21 is fed along the body continuous-feed 
line 9 while suspended by the hanger 17 and is transferred to the body 
indexed-feed line 10 by the feeder 10a. Then the vehicle body 21 is fed 
along the body indexed-feed line 10 to the mounting station 13 through the 
slippage detecting station 11. When the vehicle body 21 is stopped at the 
slippage detecting station 11, the visual sensors 22 detect the slippage 
in the position of the vehicle body 21 from the regular position, and the 
outputs of the sensors 22 are input into said controller for controlling 
the hydraulic cylinder 110 and the driving motors 125, 143 and 157. That 
is, as shown in FIG. 12, a host computer 200 delivers to the visual 
sensors 22 information on the vehicle body presently fed to the slippage 
detecting station 11, and the visual sensors 22 detect the slippage in the 
position of the vehicle body 21 from the regular position on the basis of 
the information delivered from the host computer 200. The host computer 
200 also delivers to the controller 201 information on the vehicle body to 
be fed to the mounting station 13 from the slippage detecting station 11 
and on the engine assembly EA to be mounted on the vehicle body 21 at the 
mounting station 13. The outputs of the visual sensors 22 are also input 
into the controller 201. The controller 201 has a built-in memory in which 
are stored a plurality of control patterns according to which the mounting 
device 12 is to be controlled. The controller 201 selects one of the 
control patterns according to the vehicle body 21 and the engine assembly 
EA to be fed to the mounting station 13 and corrects the control pattern 
on the basis of the outputs of the visual sensors 22. 
When the engine assembly EA reaches the mounting station 13, the lifter 25 
below the mingling feed line 14 is in the part-receiving position A and 
the engine assembly EA is placed on the pallet 109 on the lifter 25. 
Thereafter, the lifter 25 is lowered to the upper conveyor position B and 
the pallet 109 is connected to the upper conveyor 24a of the transfer 
device 23. Then the engine assembly EA is fed incrementally by the upper 
conveyor 24a and is placed on the rotary table 108 of the automatic 
mounting device 12 at the other end of the transfer device 23 together 
with the pallet 109. 
When the vehicle body 21 is stopped at the mounting station 13, the 
controller 201 controls the automatic mounting device 12 according to the 
corrected pattern as described above to position the engine assembly in 
the predetermined position with respect to the vehicle body 21 taking into 
account the slippage in the position of the vehicle body 21 during feeding 
to the mounting station 13. Then the nut runners 111 are operated to fix 
the engine assembly EA to the vehicle body 21. The rear suspension is 
mounted on the vehicle body 21 in a similar manner though in the case of 
the rear suspension, the rear suspension is transferred to the rearwardly 
disposed mounting device 12 by the rear transfer means 23 and is mounted 
on the vehicle body 21 by the rearwardly disposed mounting device 12. 
The vehicle body provided with the engine assembly EA including the engine, 
the perimeter frame and the front suspension, and the rear suspension is 
fed from the mounting station 13 along the body indexing-feed line 10 and 
then returned to the body continuous-feed line 9. In the mounting station 
13, the rotary table 108 is moved downward and the pallet 109 thereon is 
transferred to the lifter 26 and then transferred to the lower conveyor 
24b. By this time, the lifter 25 on the opposite side of the transfer 
device 23 has been positioned in the lower conveyor position C and 
receives the pallet 109 from the lower conveyor 24b. Thereafter, the 
lifter 25 is moved to the part-receiving position A carrying thereon the 
pallet 109 to prepare to receive another engine assembly EA. 
As the engine assembly including the engine and the front suspension and 
the rear suspension is mounted on a vehicle body fed in indexed feed 
fashion, by respective automatic mounting devices disposed at front and 
rear portions of a single mounting station in the vehicle 
assembling-and-feeding system of this embodiment, mounting can be 
performed with high efficiency. 
Further, since, in the system of the present invention, slippage in the 
position of the vehicle body is detected at the slippage detecting station 
provided upstream of the mounting station and control on the mounting 
device is corrected on the basis of the detected slippage at the mounting 
station, the mounting operation can be performed more efficiently as 
compared with cases in which detection of slippage in the position of the 
vehicle body and correction of the control on the mounting device are both 
effected at the mounting station. 
Though the present invention is applied to assembly of front-engine 
front-drive type vehicles in the embodiment described above, the present 
invention can be applied to assembly of vehicles of other types, e.g., 
front-engine rear-drive type vehicles. 
Further, though in the embodiment described above, the mounting device is 
arranged to move the material to be mounted, e.g., the engine assembly EA, 
up and down, in the transverse direction of the vehicle body and in the 
longitudinal direction of the vehicle body and to rotate it with respect 
to the vehicle body, the mounting device may be arranged only to move the 
material to be mounted up and down, in the transverse direction of the 
vehicle body and in the longitudinal direction of the vehicle body without 
rotating it. 
Further, though in the embodiment described above, the slippage in the 
position of the vehicle body during feeding to the mounting station is 
compensated for by correcting the control patterns stored in the built-in 
memory of the controller, the slippage may be compensated for by moving 
the whole mounting device in the feeding direction of the vehicle body and 
in the direction perpendicular thereto without correcting the control 
pattern. This can be accomplished, for example, by providing between the 
mounting device and the floor a sliding member which can be slid in the 
feeding direction of the vehicle body and the direction perpendicular 
thereto and by servo-controlling the sliding member.