Conveyance device
The conveyance rollers are arranged at a predetermined roller pitch in the conveyance direction and arranged in rows so as to be capable of supporting at least the side ends of an object being conveyed. The conveyance rollers are formed along the conveyance direction by a repetition unit composed of the drive rollers and the free rollers. The roller pitch of the conveyance rollers is set based on the dimension of the object, and the smaller of distances from respective ends in the conveyance direction of the object to the position of the center of gravity of the object. The arrangement ratio of the drive rollers in the conveyance rollers is set based on the smaller of the distances from the respective ends in the conveyance direction of the object to the position of the center of gravity of the object, and the roller pitch.
1. A conveyance device comprising:
a plurality of conveyance rollers comprising a plurality of drive rollers and a plurality of free rollers, the conveyance device conveying an object by the conveyance rollers, wherein
the conveyance rollers are arranged at a predetermined roller pitch in a conveyance direction, arranged in two rows so as to be capable of supporting at least side ends of the object, and formed along the conveyance direction by a repetition unit composed of the drive rollers and the free rollers,
the roller pitch of the conveyance rollers is set on the basis of the dimension of the object, and the smaller of distances from respective ends in the conveyance direction of the object to the position of the center of gravity of the object,
an arrangement ratio of the drive rollers in the conveyance rollers is set on the basis of the smaller of the distances from the respective ends in the conveyance direction of the object to the position of the center of gravity of the object, and the roller pitch,
the repetition unit composed of the drive rollers and free rollers is set according to the arrangement ratio of the drive rollers,
the conveyance rollers are arranged in a staggered manner along the conveyance direction on the basis of the roller pitch, the arrangement ratio of the drive rollers, and the repetition unit of the conveyance rollers,
the roller pitch satisfies a first condition represented by a first equation, Equation 1,
P
<
2
YLXG
2
YL
-
YG
P
:
Roller
Pitch
XG
:
X
Coordinate
of
Center
of
Gravity
YG
:
Y
Coordinate
of
Center
of
Gravity
YL
:
Width
of
Object
(
Length
in
Direction
Perpendicular
to
Conveyance
Direction
)
and
,
a
second
condition
is
satisfied
by
a
second
equation
,
Equation
2
,
[
Equation
1
]
R
≧
Quo
(
XL
+
P
2
,
P
)
-
1
Quo
(
XL
+
P
2
,
P
)
R
:
Arrangement
Ratio
of
Drive
Rollers
P
:
Roller
Pitch
XL
:
Length
of
Object
(
Length
in
Conveyance
Direction
)
Quo
(
XL
+
P
2
,
P
)
:
Quotient
Obtained
by
Dividing
XL
+
P
2
by
P
[
Equation
2
]
wherein the arrangement ratio of the drive rollers satisfies the second condition represented by Equation 2.