Title: Transfer system
Abstract: A transfer system includes transfer lines (L) each of which forms a closed loop and has transfer-in stations (S1 and S3) and transfer-out stations (S2 and S4) for assembling parts to a work, while circulating the work along the transfer line (L); and a work and part transfer passage (51) for transferring the work and the parts. Transfer-in stations (S1 and S3) and the transfer-out stations (S2 and S4) are disposed at each of the longitudinal ends of each of the transfer lines (L). Sub-transfer-passages (521 and 522) branching out rightward and leftward from the work and part transfer passage (51), are disposed along longitudinal sides of the transfer lines (L). With this layout, a plurality of the transfer lines (L) can be disposed in a required minimum space, while securing a smooth supply and discharge of the works and parts with respect to the plurality of the transfer lines L.
Patent Number: 6,986,417 Issued on 01/17/2006 to Nishizawa, et al.
| Inventors:
|
Nishizawa; Yoshihiro (Saitama, JP);
Mitsuhashi; Masami (Saitama, JP);
Kubota; Keiichi (Saitama, JP);
Ikeda; Kouichi (Saitama, JP);
Murakami; Hideo (Saitama, JP)
|
| Assignee:
|
Honda Giken Kogyo Kabushiki Kaisha (Tokyo, JP)
|
| Appl. No.:
|
661507 |
| Filed:
|
September 15, 2003 |
Foreign Application Priority Data
| Nov 04, 1998[JP] | 10-313524 |
| Nov 30, 1998[JP] | 10-340550 |
| Current U.S. Class: |
198/370.01; 414/285 |
| Current Intern'l Class: |
B65G 47/10 (20060101) |
| Field of Search: |
198/37001
414/285
|
References Cited [Referenced By]
U.S. Patent Documents
| 4307988 | Dec., 1981 | Page et al.
| |
| 5012917 | May., 1991 | Gilbert et al.
| |
| 5125782 | Jun., 1992 | Goldschmidt et al.
| |
| 5271490 | Dec., 1993 | Sticht.
| |
| 5468110 | Nov., 1995 | McDonald et al.
| |
| 5593018 | Jan., 1997 | Gosdowski et al.
| |
| 6139240 | Oct., 2000 | Ando.
| |
| 6629592 | Oct., 2003 | Bernard et al.
| |
| Foreign Patent Documents |
| A-61-81320 | Apr., 1988 | JP.
| |
| B2-4-57555 | Sep., 1992 | JP.
| |
| A-4-306162 | Oct., 1992 | JP.
| |
| 58-71049 | Apr., 1993 | JP.
| |
| A-8-215944 | Aug., 1996 | JP.
| |
| A-10-1662/30 | Jun., 1998 | JP.
| |
| A-10-2170/47 | Aug., 1998 | JP.
| |
| 1351749 | Nov., 1987 | RU.
| |
Primary Examiner: Dillon, Jr.; Joe
Attorney, Agent or Firm: Arent Fox PLLC
Parent Case Text
This is a Continuation-in-Part of application Ser. No. 09/807,988 filed Aug.
10, 2001 U.S. Pat. No. 6,626,282. The disclosure of the prior application(s) is
hereby incorporated by reference herein in its entirety. This application is a
371 and claims the priority of foreign application No. PCT/JP99/06130 filed Nov.
4, 1999 in Europe, Application No. 10-313524 filed Nov. 4, 1998 in Japan and application
Ser. No. 10-340550 filed Nov. 30, 1998 in Japan are claimed under 35 U.S.C. §119
and/or §365(b).
Claims
The invention claimed is:
1. A transfer system comprising:
a plurality of transfer lines, each transfer line forming a closed loop and having
transfer-in stations and transfer-out stations for assembling parts to a work,
while circulating the work along the transfer line;
a work and part transfer passage for transferring the work and the parts; and
sub-transfer-passages branching out from the work and part transfer passage;
wherein the work and part transfer passage completely separates the plurality
of transfer lines into first and second groups of transfer lines, wherein longitudinal
ends of each transfer line faces a side of the work and part transfer passage;
wherein the transfer-in stations and the transfer-out stations are disposed at
each of the longitudinal ends of each of the transfer lines; and
wherein the sub-transfer-passages completely separate the plurality of transfer
lines into third and fourth groups of transfer lines, which are different from
the first and second groups of transfer lines and wherein the sub-transfer-passages
are disposed on longitudinally sides of the transfer lines.
2. A transfer system according to claim 1, wherein longitudinal ends of a pair
of the transfer lines face opposite sides of the work and part transfer passage.
3. A transfer system according to claim 2, wherein transfer directions of the
pair of the transfer lines disposed on the opposite sides of the work and part
transfer passage are reverse to each other; the transfer-in stations of one transfer
line oppose to the same of the other transfer line, with the work and part transfer
passage therebetween; and the transfer-out stations of one transfer line oppose
to the same of the other transfer line, with the work and part transfer passage therebetween.
4. A transfer system according to claim 1, wherein a pair of the transfer lines
are disposed along one side of the sub-transfer-passages, and another pair of the
transfer lines are disposed along the other side of the sub-transfer-passages.
Description
FIELD OF THE INVENTION
The present invention relates to a transfer system for carrying out the assembling
of parts to a work, while circulating the work along a transfer line forming a
closed loop.
BACKGROUND ART
Such a transfer system for carrying out the assembling of parts, while circulating
a pallet with a work placed thereon along a transfer line forming a closed loop
is conventionally known (see Japanese Patent Publication No. 4-57555). In the above
known transfer system, a pallet-shaped carriage on which a work can be placed is
circulated on rails placed along a quadrilateral transfer line. In this case, the
carriage is allowed to travel by connecting and disconnecting an endless chain,
circulatively driven along the rails by a drive source, to or from the carriage,
or the carriage is allowed to travel pitch by pitch by bringing the carriage into
and out of engagement with a rack which is reciprocally driven through a predetermined
distance along the rails by a drive source, and during this time, the assembling
of parts to the work placed on the carriage is carried out.
However, since it is necessary to supply parts to be assembled to a work
from the outside, to the carriage in succession, the above known system suffers
from a problem that, when a plurality of transfer lines are additionally provided
in the system, it is difficult to secure a space for smoothly supplying the parts
to these transfer lines and to enhance the working efficiency.
DISCLOSURE OF THE INVENTION
The present invention has been accomplished in view of the above circumstances,
and it is an object of the present invention to provide a transfer system for assembling
parts to a work while circulating the work along a plurality of transfer lines
each forming a close loop, in which the transfer lines can be disposed in a required
minimum space while securing smooth supply and discharge of the works and parts
with respect to the transfer lines.
To achieve the object, according to a first feature of the present invention,
there is provided a transfer system comprising transfer lines each of which forms
a closed loop and has transfer-in stations and transfer-out stations for assembling
parts to a work, while circulating the work along the transfer line; a work and
part transfer passage for transferring the work and the parts; and sub-transfer-passages
branching out from the work and part transfer passage; wherein longitudinal ends
of each of the transfer lines face a side of the work and part transfer passage;
wherein the transfer-in stations and the transfer-out stations are disposed at
each of the longitudinal ends of each of the transfer lines; and wherein the sub-transfer-passages
are disposed on longitudinally sides of the transfer lines.
With the above arrangement, the longitudinal ends of each of the plural transfer
lines face a side of the work and part transfer passage, and the transfer-in stations
and the transfer-out stations are disposed at each of the longitudinal ends of
each of the transfer lines. Therefore, the plurality of the transfer lines can
be compactly disposed in a required minimum space while facilitating smooth supply
and discharge of the works and parts, from the common work and part transfer passage,
with respect to the plurality of the transfer lines. Further, the sub-transfer-passages
branching out from the work and part transfer passage are disposed on longitudinally
sides of the transfer lines. Therefore, it is possible to easily supply the parts
to the intermediate portions of the transfer lines.
According to a second feature of the present invention, in addition to
the first feature, there is provided a transfer system wherein longitudinal ends
of a pair of the transfer lines face opposite sides of the work and part transfer passage.
With the above arrangement, since the longitudinal ends of the pair of the transfer
lines face opposite sides of the work and part transfer passage, it is possible
to effectively utilize a narrow long space to compactly dispose therein the pair
of the transfer lines.
According to a third feature of the present invention, in addition to the
second feature, there is provided a transfer system, wherein transfer directions
of the pair of the transfer lines disposed on the opposite sides of the work and
part transfer passage are reverse to each other, the transfer-in stations of one
transfer line oppose to the same of the other transfer line, with the work and
part transfer passage therebetween; and the transfer-out stations of one transfer
line oppose to the same of the other transfer line, with the work and part transfer
passage therebetween.
With the above arrangement, the transfer directions of the pair of the transfer
lines disposed on the opposite sides of the work and part transfer passage are
reverse to each other, the transfer-in stations of one transfer line oppose to
the same of the other transfer line, with the work and part transfer passage therebetween;
and the transfer-out stations of one transfer line oppose to the same of the other
transfer line, with the work and part transfer passage therebetween. Therefore,
it is possible to further smoothly perform the supply and discharge between the
work and part transfer passage and the transfer lines.
According to a fourth feature of the present invention, in addition to
the first feature, there is provided a transfer system, wherein a pair of the transfer
lines are disposed along one side of the sub-transfer-passages, and another pair
of the transfer lines are disposed along the other side of the sub-transfer-passages.
With the above arrangement, since the pair of the transfer lines are disposed
along one side of the sub-transfer-passages, and another pair of the transfer lines
are disposed along the other side of the sub-transfer-passages, it is possible
to smoothly perform the supply and discharge between the work and part transfer
passage and the total four transfer lines while compactly disposing the four transfer lines.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 to 9 show one embodiment of the present invention, wherein FIG. 1 is
a plan view of a sub-line for sub-assembling a door of an automobile; FIG. 2 is
a sectional view taken along a line 2—2 in FIG. 1; FIG. 3 is
a view taken along a line 3—3 in FIG. 1; FIG. 4 is a sectional
view taken along a line 4—4 in FIG. 1; FIG. 5 is an enlarged
view of a portion indicated by 5 in FIG. 1; FIG. 6 is a view taken in the
direction of an arrow 6 in FIG. 5; FIG. 7 is a view taken in the direction
of an arrow 7 in FIG. 5; and FIGS. 8A and 8B are views for explaining the
operation of a traverser. FIG. 9 is a view showing a combination of four sub-lines
for sub-assembling a rear door, a tail gate, a front door and a bonnet hood.
BEST MODE FOR CARRYING OUT THE INVENTION
As shown in FIG. 1, a transfer system of this embodiment is utilized in a sub-line
provided sideways of a main line for assembling an automobile, and is operable
to assemble parts by an operator riding on a pallet P, while circulating left and
right rear doors D
L and D
R as works removed from a vehicle
body of an automobile flowing in a main line on a closed transfer line L in a state
in which they have been placed on the pallet P. The left and right rear doors D
L
and D
R having the parts assembled thereto are returned to the
main line where they are attached again to the vehicle body of the automobile.
The transfer line L in the transfer system is comprised of a first conveyer C
1
and a second conveyer C
2 disposed in parallel to each other, a first
traverser T
1 extending from a terminal end of the first conveyer C
1
toward a start end of the second conveyer C
2, and a second traverser
T
2 extending from a terminal end of the second conveyer C
2 toward
a start end of the first conveyer C
1. The entire transfer line L is
formed into a rectangular shape having long sides along transferring directions
of the first and second conveyers C
1 and C
2 and short sides
along transferring directions of the first and second traversers T
1 and T
2.
A work transfer-in station S
1 and a work transfer-out station S
2
are disposed adjacent each other sideways of the first conveyer C
1.
The doors D
L and D
R transferred from the main line by a carriage
(not shown) are temporarily stored in the work transfer-in station S
1,
and a pair of the left and right doors D
L and D
R are sequentially
transported from the work transfer-in station S
1 onto each of the pallets
P of the transfer system at a transporting device B
1. The pallet P which
has received the pair of the left and right doors D
L and D
R in
the work transfer-in station S
1 is circulated from the terminal end
of the first conveyer C
1 on the first traverser T
1, the second
conveyer C
2, the second traverser T
2 and the first conveyer
C
1. When the doors D
L and D
R to which the parts
have been attached during this time reach the work transfer-out station S
2,
they are expelled from the pallet P by a transporting device B
2. A predetermined
numbers of the doors D
L and D
R are placed onto the carriage
and returned to the main line.
The structure of the pallet P will be described with reference to FIGS. 5 to 7.
The pallet P includes a base plate
11 formed into a quadrilateral plate-shape,
and four casters
12 are mounted on a lower surface of the base plate
11.
Each of the first and second conveyers C
1 and C
2 has a pair
of rails
13,
13, so that the four casters
12 are guided on
the rails
13,
13. A pair of guide rollers
14,
14 are
respectively provided in the vicinity of the two casters
12,
12 on
laterally one side of the pallet P, so that the casters
12 is prevented
from being derailed from the rails
13,
13 by rolling of the guide
rollers
14,
14 along opposite side surfaces of either one of the
rails
13.
Two door supporting jigs
15 and
16 forming work supporting jigs
of the present invention are raised on an upper surface of the pallet P. The left
door D
L is supported in a righted attitude on a support arm
152
which is provided on one of the door supporting jigs
15 and lifted
and lowered by an air cylinder
151, and the right door D
R
is supported in a righted attitude on a support arm
162 which
is provided on the other door supporting jig
16 and lifted and lowered by
an air cylinder
161. A tray support
17 forming a part
support of the present invention is provided at laterally one side of the pallet
P to protrude in a lateral direction, so that a multi-stage part tray
18,
on which parts p
1 to p
5 (a window glass, an inner panel,
a small-size part and the like) to be assembled to each of the doors D
L and
D
R placed on the pallet P have previously been set, can be placed on
the tray support
17.
An air tank
19 filled with air is mounted on the pallet P, so that air
for driving the air cylinders
151 and
161 and
air for driving an air tool T such as an impact wrench for assisting in the assembling
of the parts p
1 to p
5 on the pallet P are supplied from the
air tank
19. More specifically, a piping L
1 extending from the
air tank
19 is connected to the air cylinder
151 of the
door support jig
15 for the left door D
L and to an air tool connection
39 provided in the vicinity of the air cylinder
151, and
the air tool T is releasably connected to the air tool connection
39 through
an air hose
40. Likewise, a piping L
2 extending from the air
tank
19 is connected to the air cylinder
161 of the door
support jig
16 for the right door D
R and to an air tool connection
41 provided in the vicinity of the air cylinder
161, and
the air tool T is releasably connected to the air tool connection
41 through
an air hose
42.
A coupling
20 and a piping L
3 for supplementing air to the
air
tank
19 from the outside are mounted on the tray support
17 of the
pallet P.
The structures of the first and second conveyers C
1 and C
2 will
be described below with reference to FIGS. 1,
2 and
4. The first
and second conveyers C
1 and C
2 are disposed point-symmetrical
with respect to the center of the transfer system and have substantially the same
structure and hence, the structure of the first conveyer C
1 will be
described below as a representative.
The first conveyer C
1 includes the pair of left and right rails
13,
13 for guiding the four casters
12 of the pallet P, and opposite
ends of the rails
13,
13 extend within the first and second traversers
T
1 and T
2. A pair of left and right transfer-in drive rollers
21,
21 and a pair of main drive rollers
22,
22 are
mounted at the start end of the first conveyer C
1, and a pair of left
and right brake rollers
23,
23 and a pair of left and right transfer-out
drive rollers
24,
24 are mounted at the terminal end of the first
conveyer C
1. Each of the rollers
21,
21;
22,
22;
23,
23; and
24,
24 forming friction rollers of the
present invention is formed of a elastic material such as a rubber, and driven
by a motor
25 mounted at a lower portion thereof to abut against the left
and right long sides of the pallet P to generate a driving force or a braking force.
The pallets P are moved by abutment of the rollers
21,
21;
22,
22;
23,
23; and
24,
24 formed of such an elastic
material and hence, the structure of the drive system for the first and second
conveyers C
1 and C
2 can be extremely simplified, and also
the generation of a vibration and a noise can be maintained to the minimum to drive
the pallets P smoothly.
A plurality of the pallets P are disposed without gaps on the first conveyer
C
1,
and the main drive rollers
22,
22 urge the plurality of pallets P
laying on the first conveyer C
1 from the rear to move them simultaneously
by continuously driving one pallet P located at the start end of the first conveyer
C
1 at a low speed. The brake rollers
23,
23 apply a braking
force to one of the plurality of pallets P moved by the main drive rollers
22,
22, which is located at the terminal end of the first conveyer C
1,
thereby preventing the pallet P from overrunning onto the first traverser T
1.
The transfer-out drive rollers
24,
24 are driven at a speed higher
than that of the main drive rollers
22,
22, when one pallet P located
at the terminal end of the first conveyer C
1 is to be separated from
the succeeding pallet P and moved to the start end of the first traverser T
1.
The transfer-in drive rollers
21,
21 are driven at a speed higher
than that of the main drive rollers
22,
22, when one pallet P located
at the terminal end of the second traverser T
2 is to be moved to the
start end of the first conveyer C
1 to catch up with the final pallet
P on the first conveyer C
1.
A loaded tray transfer-in station S
3 is provided at the start end
of
the second conveyer C
2 for supplying the part tray
18 on which
the parts p
1 to p
4 to be assembled to the doors D
L and
D
R placed on the pallet P have been set.
The structures of the first and second traversers T
1 and T
2 will
be described below with reference to FIGS. 1,
3 and
4. The first
and second traversers T
1 and T
2 are disposed point-symmetrically
with respect to the center of the transfer system and have substantially the same
structure and hence, the structure of the first traverser T
1 will be
described below as a representative.
The first traverser T
1 has three roller conveyers
26,
27
and
28 capable of supporting the lower surface of the pallet P. The roller
conveyers
26,
27 and
28 are disposed in line from the terminal
end of the first conveyer C
1 toward the start end of the second conveyer
C
2. Each of the roller conveyers
26,
27 and
28
is capable of being lifted and lowered synchronously by cylinders
29, and
the level of the transfer surface thereof in a lifted position is higher than the
level of the lower surface of the pallet P on the first and second conveyers C
1
and C
2, while the level of the transfer surface thereof in a lowered
position is lower than the level of the lower surface of the pallet P on the first
and second conveyers C
1 and C
2.
Each roller of the roller conveyers
26,
27 and
28 is a
free roller having no drive source, and the movement of the pallet P is carried
out by a rodless cylinder
30 disposed along one side of the first traverser
T
1. An output member
31 reciprocally movable along the rodless
cylinder
30 is capable of being righted up and tilted down. The righted-up
output member
31 is engaged with one of short sides of the pallet P, and
the tilted-down output member
31 is retreated downwards, so that it does
not interfere with the pallet P.
Two stoppers
32,
32 are provided at the start end of the first
traverser T
1 and capable of abutting against the front short side of
the pallet P in an advancing direction of the pallet P to stop the pallet P moved
from the first conveyer C
1 to the start end of the first traverser T
1.
Two stoppers
33,
33 are provided at the terminal end of the first
traverser T
1 and capable of abutting against the front long side of
the pallet P in the advancing direction of the pallet P to stop the pallet P moved
from the start end of the first traverser T
1 to the terminal thereof.
Provided at one side of the first traverser T
1 are two guide rollers
34,
34 for guiding the right short side of the pallet P in the advancing
direction, and a single guide rail
35.
A rodless cylinder
36 is mounted between the terminal end of the first
traverser
T
1 and the start end of the second conveyer C
2, and an output
member
37 reciprocally movable along the rodless cylinder
36 is capable
of being righted up and tilted down between a position in which it engages the
lower surface of the pallet P and a position in which it does not interfere with
the lower surface of the pallet P.
An empty-tray transfer-out station S
4 for discharging the empty part
tray
18 from the pallet P is provided at the terminal end of the first traverser
T
1. An air supply means
38 is provided in the empty-tray transfer-out
station S
4 and connected to the coupling
20 mounted on the pallet
P for supplying air.
The operation of the embodiment of the present invention having the above-described
arrangement will be described below.
When empty one of the plurality of pallets P moved on the first conveyer C
1
at a low speed, which is first in the advancing direction, is passed through the
work transfer-in station S
1, a pair of left and right doors D
L
and D
R are transported to the door support jigs
15 and
16 of such empty pallet P by the transporting device B
1. At this
time, the plurality of pallets P are connected together in close contact with one
another on the first conveyer C
1, and the pallet P lying at the terminal
end of the second traverser T
2 is in succession behind a pallet P
1
in the advancing direction, which lies at the end of the plurality of pallets
P in the advancing direction (namely, behind the pallet P lying at the start end
of the first conveyer C
1).
When the pallet P having the doors D
L and D
R transported
thereto in the work transfer-in station S
1 reaches the position at the
transfer-out drive rollers
24,
24 which are being rotated at a high
speed, such pallet P is separated from the succeeding pallet P and moved to the
start end of the first traverser T
1. At this time, the three roller
conveyers
26,
27 and
28 of the first traverser T
1 are
in their lowered positions and hence, the roller conveyer
26 laying between
the two rails
13,
13 of the first conveyer C
1 and the
pallet P cannot interfere with each other. The pallet P which has newly reached
the work transfer-in station S
1 of the first conveyer C
1 is
braked by contact with the brake rollers
23,
23 generating the braking
force and thus, is prevented from overrunning to the start end of the first traverser
T
1. The leading pallet P in the advancing direction on the second conveyer
C
2 is separated from the succeeding pallet P in parallel with the operation
of the first conveyer C
1 and is moved to the start end of the second
traverser T
2.
Now, when the pallet P moved from the terminal end of the first conveyer C
1
to the start end of the first traverser T
1 is put into abutment against
the stoppers
32,
32 and thus stopped, the cylinders
29 are
expanded to lift the three roller conveyers
26,
27 and
28
synchronously, whereby the pallet P is lifted by the roller conveyer
26
on the side of the start end (see FIG. 8A). Then, when the output member
31
is righted up to engage one of the long sides of the pallet P, the pallet P pushed
by the output member
31 driven by the rodless cylinder
30 is moved
on the roller conveyers
26,
27 and
28 and put into abutment
against the stoppers
33,
33 at the terminal end of the first traverser
T
1 and thus stopper (see FIG. 8B). At this time, there is no possibility
that the pallet P may interfere with the rails
13 of the first and second
conveyers C
1 and C
2, because the roller conveyers
26,
27 and
28 are in their lifted positions.
When the pallet P has reached the terminal end of the first traverser T
1,
the cylinders
29 are contracted to lower the roller conveyers
26,
27 and
28, whereby the pallet P carried on the roller conveyer
28
is transported onto the rails
13,
13 of the second conveyer C
2.
When the pallet P is moved from the start end to the terminal end of the first
traverser T
1 in the above manner, the pallet P is moved in a similar
action from the start end to the terminal end of the first traverser T
1 in
parallel with the above-described movement.
In this manner, the roller conveyers
26,
27 and
28 of the
first and second traversers T
1 and T
2 are lifted and lowered
to deliver the pallets P between the first and second conveyers C
1 and
C
2. Therefore, it is possible to prevent the pallets P from interfering
with the first and second conveyers C
1 and C
2 to smoothly
transport the pallets P between the first and second conveyers C
1 and
C
2 and the first and second traversers T
1 and T
2.
The central roller conveyer
27 need not be necessarily lifted and lowered,
and may be fixed in the lifted position.
The empty-tray transfer-out station S
4 is provided at the terminal
end of the first traverser T
1, and the empty part tray
18 supported
on the tray support
17 on the pallet P is removed and discharged to the
empty-tray transfer-out station S
4 by an automatic discharge conveyer
39. At the same time, the air supply means
38 provided in the empty-tray
transfer-out station S
4 is connected to the coupling
20 of the
pallet P, and air is filled into the air tank
19.
Since the air tank
19 is mounted on the pallet P, as described above,
the handling of the air hose can be simplified, as compared with a case where air
is supplied from the outside of the pallet P. Moreover, even if the pallet P is
moved, the same air tool T can be used continuously, leading to an enhanced operability.
Further, air can be supplied to the air tank
19, while the pallet P is being
circulated along the transfer line L, and hence, it is extremely easy to supply
air to the air tank
19.
Then, the pallet P at the terminal end of the first traverser T
1
is moved to the start end of the second conveyer C
2 by the transfer-in
drive rollers
21,
21 and connected to the pallet P at the end of
the plurality of pallets P moved at a low speed on the second conveyer C
2
in the advancing direction. At this time, the rodless cylinder
36
is operated to cause the output member
37 to urge the pallet P, thereby
assisting in the operation of the transfer-in drive rollers
21,
21.
In parallel with this, the pallet P at the terminal end of the second traverser
T
2 is also moved on the first conveyer C
1 by the transfer-in
drive rollers
21,
21 and the rodless cylinder
36 and is connected
to the pallet P at the end of the plurality of pallets P moved at a low speed on
the first conveyer C
1 in the advancing direction.
When the pallet P which has moved from the terminal end of the first traverser
T
1 to the start end of the second conveyer C
2 is passed through
the loaded tray transfer-in station S
3, the part tray
18, on
which the parts p
1 to p
5 to be assembled to the doors D
L
and D
R have been set, is placed on the tray support
17
of the pallet P by an automatic supply conveyer
44.
Two operators riding on the pallet P complete the operation of assembling the
parts p
1 to p
5 on the part tray
18 to the doors D
L
and D
R within a period of movement of the pallet P from the first
conveyer C
1 via the second traverser T
2 to the work transfer-out
station S
2 of the first conveyer C
1. During this time, air
for operating the air tool T such as the impact wrench is supplied from the air
tank
19 mounted on the pallet P, and air for operating the air cylinders
151 and
161 for lifting the doors D
L and
D
R to a level suitable for the operation is also supplied from the air
tank
19. When the pallet P has reached the work transfer-out station S
2
of the first conveyer C
1, the doors D
L and D
R
which have been assembled are discharged from the pallet P to the work transfer-out
station S
2, thus finishing the process of one cycle.
By previously mounting the part tray
18, on which the parts p
1
to p
5 to be assembled to the doors D
L and D
R have
been set, on the pallet P, it is unnecessary to conduct the sequential supplying
of the parts to the pallet P which is being moved, leading to a remarkably enhanced operability.
As described above, the first and second conveyers C
1 and C
2
can
collectively drive the plurality of pallets P connected in contact with one another
forwards by driving the rearmost pallet P by the main drive rollers
22,
22. Therefore, if it is necessary to prolong the lengths of the first and
second conveyers C
1 and C
2, only the lengths of the rails
13 of the first and second conveyers C
1 and C
2 may
be prolonged, and it is unnecessary to provide any change to the main drive rollers
22,
22 and the other rollers
21,
21;
23,
23;
and
24,
24. Therefore, it is extremely easy to modify the length
of the transfer line L.
Most of the closed transfer line L for circulation of the pallets P are utilized
for the operation of assembling the parts p
1 to p
5 and hence,
a portion of the transfer line L required for only the returning of the empty pallets
P is nearly eliminated, thereby providing an effective utilization of a space.
On the contrast, in the prior art in which a return line for returning an empty
pallet P is provided separately from an operating line for transferring a loaded
pallet P having doors D
L and D
R, a space in which the returning
line is provided is useless. In a system in which a returning line is provided
within a pit made by drilling a floor surface in order to avoid the uselessness
of a space, there is a problem that the making of the pit by drilling becomes of
a large scale and hence, the working cost is increased remarkably. With the transfer
system according to the present invention, however, it is extremely easy to change
the length of the transfer line L, and also an assembling line having a high operability
can be constructed at a minimum space and a minimum equipment cost.
Further, a working space W
0 is provided inside the transfer line
L surrounded by the first and second conveyers C
1 and C
2 and
the first and second traversers T
1 and T
2 (see FIGS. 1 and
2), and hence, it is possible for the operator to easily access any of the pallets
P on the transfer line L through the working space W
0, leading to a
further enhanced operability.
In the above-described transfer lines L, for convenience, the work transfer-in
stations S
1 and the work transfer-out stations S
2 are disposed
on the side of the first conveyers C
1; the loaded tray transfer-in station
S
3 is disposed at the start end of the second conveyers C
2;
the empty-tray transfer-out station S
4 is disposed at the terminal end
of the first traversers T
1. However, the locations of the station S
1
to S
4 may be changed as desired.
As shown in FIG. 9, four transfer lines L are disposed in a distributed manner
on opposite left and right sides of a work and part transfer passage
51
extending vertically through the center. The left upper transfer line L is used
for assembling rear doors; the left lower transfer line L is used for assembling
a tail gate; the right upper transfer line L is used for assembling front doors;
and the right lower transfer line L is used for assembling a bonnet hood. The transfer
line L for assembling rear doors and the transfer line L for assembling front doors
are disposed along one longitudinal side of sub-transfer-passages
521
and
522 which branch out from opposite sides of the work and
part transfer passage
51, and the transfer line L for assembling a tail
gate and the transfer line L for assembling a bonnet hood are disposed along the
other longitudinal side of the sub-transfer-passages
521 and
522. The work transfer-in stations S
1 and the loaded
tray transfer-in station S
3 as well as the work transfer-out stations
S
2 and the empty-tray transfer-out station S
4 are disposed
at the ends, facing the work and part transfer passage
51, of each of the
transfer lines L.
As described above, the longitudinal ends of the plurality of the transfer lines
L face the work and part transfer passage
51, and the transfer-in stations
S
1 and S
3 as well as the transfer-out stations S
2 and
S
4 are disposed at the longitudinal ends of each of the transfer lines
L. Therefore, the plurality of the transfer lines L can be arranged in a required
minimum space, while facilitating the supply and discharge of the works and parts
with respect to the plurality of the transfer lines L.
Particularly, since the pair of the right and left transfer lines L
(the transfers line L for assembling rear doors and the transfers line L for assembling
front doors, or the transfer line L for assembling a tail gate and the transfers
line L for assembling a bonnet hood) are deposed in line in right and left directions,
the right and left transfer lines L can be compactly disposed in a narrow long
space. Also, since the four transfer lines L are disposed in four directions from
the intersection point of the work and part transfer passage
51, the sub-transfer-passages
521 and
522, it is possible to achieve a further
space reduction. Moreover, since the sub-transfer-passages
521 and
522 branch out from the work and part transfer passage
51
and extend in the longitudinal direction along all the transfer lines L, it is
possible to easily supply the parts to the intermediate portions of the transfer
lines L.
Further, the transfer direction is the clockwise in the transfer lines L
for assembling rear doors and a tail gate on the right side of the work and part
transfer passage
51, and the transfer direction is the counterclockwise
in the transfer lines L for assembling front doors and a bonnet hood on the left
side of the work and part transfer passage
51. Therefore, in the transfer
line L for assembling rear doors and the transfer line L for assembling front doors
which oppose to each other with the work and part transfer passage
51 therebetween,
the transfer-in stations S
1 and S
3 of one transfer line L
oppose to the same of the other transfer line L, and the transfer-out stations
S
2 and S
4 of one transfer line L oppose to the same of the
other transfer line L. As a result, the transfer-in and transfer-out operations
of the works and parts can be smoothly performed, as compared with the case where
the transfer-in stations S
1 and S
3 face the transfer-out
stations S
2 and S
4. This advantage is also provided by the
layout of the transfer lines L for assembling a tail gate and the transfer lines
L for assembling a bonnet hood which oppose to each other with the work and part
transfer passage
51 therebetween.
As described above, the employment of this layout ensures that the work and part
transfer passage
51 can commonly be used by the four transfer lines L and
a space can be utilized further effectively, and also the length of the transfer
lines L can be increased or decreased as required. Therefore, it is possible to
easily accommodate to the change in type of the system or the like. If each of
the transfer-in stations S
1 and S
3 and the transfer-out stations
S
2 and S
4 is formed of a lifter, and works and parts are
transferred in and out through an overhead conveyer, the area for the transfer
lines L can be reduced. Further, since the working spaces W
1 to W
4
are provided inside the four transfer lines L, an operator can easily access
any of the pallets P through the working spaces W
1 to W
4,
leading to a further enhanced operability.
Although the embodiments of the present invention have been described in
detail, it will be understood that the present invention is not limited to the
above-described embodiments, and various modifications in design may be made without
departing from the spirit and scope of the invention defined in the claims.
For example, in the present embodiments, the plurality of the transfer lines
L are disposed on opposite sides of the work and part transfer passage
51,
however, they may be disposed on one side of the work and part transfer passage
51.
Also, the present invention is applicable to a line for assembling any works
other than a door, a tail gate and a bonnet hood of an automobile.
INDUSTRIAL APPLICABILITY
As described above, such transfer system according to the present invention is
useful for carrying out the operation of assembling parts to any work on the pallet
of the conveyer, and particularly, is suitably applicable to a sub-line for assembling
sub-assemblies for a four-wheel or two-wheel vehicle.
*
