[Technical Field]
[0001] This invention relates to a sheet guide apparatus which is provided in a printing
press (may hereinafter be referred to as the machine) for printing a sheet, or a coater
for coating a sheet, and which transports, in a stable state, a sheet to be transported.
[Background Art]
[0002] In a multicolor sheet-fed printing press for four colors, for example, a transfer
cylinder (intermediate cylinder) 104 is disposed between respective printing units
(103a to 103d) in a printing unit section 102 located between a feeder unit 100 and
a delivery unit 101, as shown in Fig. 12. A sheet of paper (or a sheet) moves from
an impression cylinder 105 of the preceding unit past the transfer cylinder 104 to
an impression cylinder 105 of the succeeding unit via a gripper device (paper gripping
device; not shown). The printing press for thin paper adopts a cylinder-shaped shell
as the transfer cylinder 104. The printing press for thick paper, on the other hand,
adopts a skeleton shell, and is designed to avoid marked bending of tough thick paper.
[0003] In recent years, there has been a demand for a printing press suitable for both of
thin paper and thick paper, and a printing press of a skeleton configuration adaptable
to both of thin paper and thick paper has appeared. As will be understood from what
has been mentioned above, such a printing press is at a disadvantage against thin
paper. Thin paper without toughness is not supported by a cylinder, and thus moves
unstably, causing a printing trouble. The same holds true of coating on a sheet and,
if the sheet is thin, a coating failure occurs. In order to stabilize the sheet being
transported, thereby preventing the printing trouble or coating failure, therefore,
it has been common practice to provide various sheet guide devices along the transfer
cylinder, constructed as the skeleton shell, for passing the sheet on to the impression
cylinder (see Patent Document 1 and Patent Document 2).
[0004] Moreover, Patent Document 3 discloses a printing press in which an air blowing means
comprising a discharge duct and discharge nozzles is provided above a transfer position
at which the sheet is passed from the skeleton shell on to the impression cylinder,
and air is blown on the sheet received by the impression cylinder to suppress the
unstable motion of the sheet.
[Citation List]
[Patent Literature]
[Summary of Invention]
[Technical Problem]
[0006] With the printing press of Patent Document 3 mentioned above, however, the unstable
motion of the sheet is not similar depending on the type of the sheet, the size of
the sheet, a printing image, etc. Thus, an operator has adjusted the flow rate of
air by relying on the operator's experience and intuition.
[0007] Thus, a heavy burden is imposed on the operator, and a less experienced operator
has difficulty in making adjustment and cannot suppress the unstable motion of the
sheet. This has posed the problem that a printing trouble due to the unstable motion
of the sheet cannot be prevented. As a result, the operation rate of the machine is
low, and a waste sheet occurs.
[0008] US 2007/006754A1 describes that the position of a sheet 1 is measured with a sensor 18, the characteristic
value of the sheet position is obtained from the measured value, and a pneumatic device
10 is controlled for a succeeding sheet 1 in accordance with a comparison between
the characteristic value and the desired value. This document also describes that
the desired value is determined by the material for and the thickness of the sheet
1 and the printing image on the sheet 1. However, there is no description of how the
desired value is set concretely.
[0009] EP 1 352 738 A2 discloses s sheet guide apparatus which suppresses fluttering or instability in a
region which is present between the front end of a guide member and the transfer position
and where the sheet is not guided by the guide member, and thus prevents scratches
or cracks of the sheet.
[0010] DE 10 2006 019 761 A1 discloses a sheet control apparatus for a sheet fed rotary printing press, said apparatus
comprising a reflection sensor having a reflection beam transmitter and a reflection
beam receiver. The apparatus is intended to detect sheets which are travelling through
the printing machine in an uncontrolled manner.
[0011] Under these circumstances, it is an object of the present invention to provide a
sheet guide apparatus which controls an air blowing means automatically without relying
on the operator's experience and intuition, thereby sufficiently suppressing the unstable
motion of the sheet, and which enables even an operator with a limited work experience
in printing, etc. to do printing, etc. with a sense of security.
[Solution to Problem]
[0012] To solve the above-mentioned problems, the present invention provides a sheet guide
apparatus as claimed in claim 1.
[0013] The sheet guide apparatus is also
characterized in that the control means controls the air blowing means to adjust a flow rate of discharged
air so that the distance between the sheet and the detection means becomes a set distance.
[0014] The sheet guide apparatus is also
characterized in that the distance which prevents the unstable motion of the sheet differs according to
whether the sheet is a thin sheet or a thick sheet.
[0015] The sheet guide apparatus is also
characterized in that the distance, which prevents the unstable motion of the thick sheet when the sheet
is the thick sheet, is shorter than the distance which prevents the unstable motion
of the thin sheet when the sheet is the thin sheet.
[0016] The sheet guide apparatus is also
characterized in that the detection means is provided on a downstream side in a sheet transport direction
with respect to the air blowing means and on an upstream side in the sheet transport
direction with respect to a cylinder in contact with the transport cylinder.
[0017] The sheet guide apparatus is also
characterized in that the detection means is provided at a position opposing a surface of the sheet.
[0018] The sheet guide apparatus further comprises a sheet thickness input unit for inputting
a thickness of the sheet, and wherein the control means judges the sheet as a thin
sheet when the thickness of the sheet inputted by the sheet thickness input unit is
less than a given value, and judges the sheet as a thick sheet when the thickness
of the sheet inputted by the sheet thickness input unit is the given value or higher.
[0019] The sheet guide apparatus further comprises a sheet thickness input unit for inputting
a thickness of the sheet, and wherein the control means judges the sheet as a thin
sheet when the thickness of the sheet inputted by the sheet thickness input unit is
a given value or lower, and judges the sheet as a thick sheet when the thickness of
the sheet inputted by the sheet thickness input unit exceeds the given value.
[0020] The sheet guide apparatus is also
characterized in that the air blowing means includes an air discharge duct having discharge holes, and
discharge nozzles, and the control means exercises control such that air is discharged
from the discharge holes of the air discharge duct and the discharge nozzles when
the sheet is a thick sheet, and exercises control such that air is discharged only
from the discharge holes of the air discharge duct when the sheet is a thin sheet.
[0021] The sheet guide apparatus is also
characterized in that the detection means is a displacement gauge.
[Advantageous Effects of Invention]
[0022] According to the present invention, the unstable motion of the sheet is detected,
and the air blowing means is controlled automatically, whereby the flow rate of air
can be adjusted appropriately. Thus, the unstable motion of the sheet can be fully
suppressed, and the sheet can be transported stably. Hence, even a little experienced
operator can perform an operation, such as printing, with a sense of security. Since
a printing trouble due to the unstable motion of the sheet does not occur, moreover,
the rate of operation of the machine is increased, and waste sheets are also decreased.
[Brief Description of Drawings]
[0023]
[Fig. 1]
Fig. 1 is a side view of essential parts of a multicolor sheet-fed printing press
showing an embodiment of the present invention.
[Fig. 2]
Fig. 2 is a plan view of a first guide device.
[Fig. 3]
Fig. 3 is an enlarged view of a portion A in Fig. 1.
[Fig. 4]
Fig. 4 is an enlarged view of a portion B in Fig. 1.
[Fig. 5]
Fig. 5 is an enlarged view of a portion C in Fig. 1.
[Figs. 6(a) to 6(c)]
Figs. 6(a) to 6(c) are explanation drawings of the structure of a guide plate, Fig.
6(a) being a plan view, Fig. 6(b) being a side view, and Fig. 6(c) being a sectional
view.
[Fig. 7]
Fig. 7 is an enlarged side view of a second guide device.
[Fig. 8]
Fig. 8 is an enlarged plan view of the second guide device.
[Fig. 9]
Fig. 9 is a control block diagram of an air blowing device.
[Fig. 10]
Fig. 10 is an operational explanation drawing of the air blowing device for a thin
sheet.
[Fig. 11]
Fig. 11 is an operational explanation drawing of the air blowing device for a thick
sheet.
[Fig. 12]
Fig. 12 is an overall side view of a four-color sheet-fed printing press.
[Description of Embodiments]
[0024] A sheet guide apparatus according to the present invention will be described in detail
by an embodiment with reference to the accompanying drawings.
[Embodiment]
[0025] Fig. 1 is a side view of essential parts of a multicolor sheet-fed printing press
showing an embodiment of the present invention. Fig. 2 is a plan view of a first guide
device. Fig. 3 is an enlarged view of a portion A in Fig. 1. Fig. 4 is an enlarged
view of a portion B in Fig. 1. Fig. 5 is an enlarged view of a portion C in Fig. 1.
Figs. 6(a) to 6(c) are explanation drawings of the structure of a guide plate, Fig.
6(a) being a plan view, Fig. 6(b) being a side view, and Fig. 6(c) being a sectional
view. Fig. 7 is an enlarged side view of a second guide device. Fig. 8 is an enlarged
plan view of the second guide device. Fig. 9 is a control block diagram of an air
blowing device. Fig. 10 is an operational explanation drawing of the air blowing device
for a thin sheet. Fig. 11 is an operational explanation drawing of the air blowing
device for a thick sheet.
[0026] In a printing unit section of a multicolor sheet-fed printing press for four colors,
etc., an upstream-side impression cylinder 3a and a downstream-side impression cylinder
(transport cylinder) 3b are rotatably supported between right and left frames 2 erected
on a bed 1, and a transfer cylinder 4 comprising a skeleton shell is likewise rotatably
supported between these impression cylinders 3a and 3b, as shown in Fig. 1. The impression
cylinders 3a, 3b and the transfer cylinder 4 are each equipped with a gripper device
(paper gripping device) 5 as a holding means for holding a printing sheet (a sheet;
see a thin sheet Wa in Fig. 10, and a thick sheet Wb in Fig. 11). In Fig. 1, the numeral
6 denotes a blanket cylinder in contact with each impression cylinder 3a or 3b.
[0027] A first guide device 7A, which guides the printing sheet being transported in a region
ranging between transfer positions P1 and P2 of the printing sheet on the upstream
and downstream sides in the flow direction of the printing sheet, is provided below
the transfer cylinder 4. Moreover, a second guide device 7B, which guides the printing
sheet transported by the downstream-side impression cylinder 3b, is provided above
the transfer position P2 of the printing sheet on the downstream side.
[0028] The first guide device 7A, as shown in Figs. 2 to 4, is divided into two portions
in the flow direction of the printing sheet, and is furnished with guide plates 15a,
15b covering the open upper surfaces of air discharge ducts 8a, 8b spreadingly provided
over most of the space between the transfer positions P1 and P2 of the printing sheet
on the upstream and downstream sides, a plate-shaped resinous guide 22b disposed in
the vicinity of the transfer position P1 of the printing sheet on the upstream side,
and a plate-shaped resinous guide 22a disposed in the vicinity of the transfer position
P2 of the printing sheet on the downstream side.
[0029] The air discharge ducts 8a, 8b are supported, on their outer end sides, by stays
10a, 10b spanning the right and left frames 2 via holders 11a, 11b and blocks 12a,
12b, and have their inner ends bound together by bolts 14 between their bars 13a and
13b, as shown in Fig. 5.
[0030] The guide plates 15a, 15b each comprise an arcuate plate extending along the movement
trajectory S of the gripper device 5 of the transfer cylinder 4, and each have many
air jet holes 16 formed to be open so that air flows rightward and leftward symmetrically
with respect to the machine center along their guide surfaces (i.e., air flows in
the sheet width direction of the printing sheet), as shown in Fig. 6(c) as well.
[0031] The interior of the air discharge ducts 8a, 8b is supplied with pressurized air from
a blower pump 19 outside the machine via pipings 17a, 17b and collecting piping 18.
[0032] Between the forward and rearward stays 10a and 10b as a pair, subframes 20a and 20b
located on both sides of the guide plates 15a and 15b are installed to span the stays
10a and 10b. Bars 21a and 21b are installed to span the front ends and rear ends of
the subframes 20a and 20b.
[0033] The plate-shaped guide 22a extending in the sheet width direction of the printing
sheet is fixed to an upper surface part of the bar 21a on the upstream side in the
transport direction of the printing sheet with respect to the transfer position P2
of the printing sheet so as to become as close as possible to the transfer position
P2 of the printing sheet. An end of the plate-shaped guide 22a facing the transfer
position P2 of the printing sheet is formed in the shape of a comb (comb-shaped) to
have notches 27a at predetermined intervals in the sheet width direction of the printing
sheet. The notches 27a are arranged parallel in the axial direction of the gripper
device 5 of the downstream-side impression cylinder 3b, and are provided at positions
corresponding to grippers so that a plurality of the grippers protruding from the
circumferential surface of the impression cylinder 3b can pass without interfering
with the plate-shaped guide 22a.
[0034] The plate-shaped guide 22b extending in the sheet width direction of the printing
sheet is fixed to an upper surface part of the bar 21b on the downstream side in the
transport direction of the printing sheet with respect to the transfer position P1
of the printing sheet so as to become as close as possible to the transfer position
P1 of the printing sheet, as is the plate-shaped guide 22a fixed to the upper surface
part of the bar 21a. An end of the plate-shaped guide 22b facing the transfer position
P1 of the printing sheet is formed in the shape of a comb (comb-shaped) to have notches
27b at predetermined intervals in the sheet width direction of the printing sheet.
The notches 27b are arranged parallel in the axial direction of the gripper device
5 of the upstream-side impression cylinder 3a, and are provided at positions corresponding
to grippers so that a plurality of the grippers protruding from the circumferential
surface of the impression cylinder 3a can pass without interfering with the plate-shaped
guide 22b.
[0035] The second guide device 7B, as shown in Figs. 7 and 8, comprises an air discharge
duct 31 and an air discharge pipe 32 installed to span the right and left frames 2
via support members such as L-shaped brackets 30a, 30b, the air discharge duct 31
having many discharge holes 31a formed in the flow direction and the sheet width direction
of the printing sheet, and the air discharge pipe 32 having many discharge nozzles
33 in the sheet width direction of the printing sheet.
[0036] The air discharge duct 31 and the air discharge pipe 32 are supplied with pressurized
air from a blower pump 35 outside the machine via pipings 34a and 34b. This pressurized
air is blown via the discharge holes 31a and the discharge nozzles 33 toward the circumferential
surface of the downstream-side impression cylinder 3b located on the downstream side
in the flow direction of the printing sheet with respect to the transfer position
P2 of the printing sheet, the directions of blowing being a direction nearly perpendicular
to the printing surface of the printing sheet and a direction opposite to the flowing
direction of the printing sheet.
[0037] In Fig. 7, the numeral 36 denotes a valve provided midway through the piping 34b
on the discharge nozzle side for supplying pressurized air from the blower pump 35
to the discharge nozzles 33, or for stopping the supply of pressurized air. The above-described
air discharge duct 31, air discharge pipe 32, discharge nozzles 33, pipings 34a, 34b,
blower pump 35 and valve 36 constitute an air blowing device (air blowing means).
[0038] A displacement gauge (detection means) 42, which is located at an intermediate part
in the sheet width direction of the printing sheet for detecting the distance to the
printing sheet being transported by the impression cylinder 3b, is installed on the
upper surface of the air discharge duct 31. A detection signal of the displacement
gauge 42 (i.e., floating amount of the printing sheet) is inputted to a control device
(control means) 40 (to be described later). The displacement gauge 42 is provided
at a position opposed to the printing surface of the printing sheet.
[0039] That is, as shown in Fig. 9, the control device 40 also receives signals from a sheet
thickness input unit 41 provided on an operating panel or the like, in addition to
the signals from the displacement gauge 42. Based on these input signals, the control
device 40 exercises opening and closing control of the valve 36 in the air blowing
device and effects driving control of a pump drive motor 43 for the blower pump 35
in the air blowing device to adjust the flow rate of discharged air in such a manner
that the distance between the printing sheet and the displacement gauge 42 is suitable
for preventing the unstable motion of the sheet.
[0040] Because of the above features, when the printing sheet is transported from the impression
cylinder 3a of the preceding printing unit to the transfer cylinder 4, and then to
the impression cylinder 3b of the succeeding printing unit via the gripper devices
5, pressurized air gushing from the air jet holes 16 of the guide plates 15a, 15b
and flowing in the sheet width direction while being directed from the center toward
both side edges of the printing sheet (see arrows in Fig. 6(c)) causes the printing
sheet to be sucked toward the guide surfaces of the guide plates 15a, 15b and transported
in a stable state along the guide surfaces. That is, the printing sheet without toughness
(e.g., thin sheet Wa) is prevented from making an unstable motion by the action of
the transfer cylinder 4 comprising the skeleton shell, thereby causing a printing
trouble.
[0041] In leading end portions of the plate-shaped guides 22a, 22b provided to be continuous
with the guide plates 15a, 15b, moreover, the many notches 27a, 27b are formed at
predetermined intervals in the sheet width direction of the printing press to avoid
interference with the grippers of the gripper devices 5 of the impression cylinders
3a, 3b, Thus, the leading end portions of the plate-shaped guides 22a, 22b not corresponding
to the grippers can be extended all the more to sites near the transfer positions
P1, P2 of the printing sheet. As a result, the zones where the printing sheet is not
guided by the guide plates 15a, 15b are rendered as narrow as possible, and the printing
sheet is transported in a stable state.
[0042] In the present embodiment, when the printing sheet passes the transfer position P2
of the printing sheet, pressurized air gushed with a predetermined length in the flow
direction of the printing sheet from the discharge holes 31a of the air discharge
duct 31 and the discharge nozzles 33 of the air discharge pipe 32 in the air blowing
device of the second guide device 7B brings the printing sheet into intimate contact
with the circumferential surface of the impression cylinder 3b to suppress its fluttering
or unstable motion, thus preventing a printing trouble.
[0043] In detail, the air blowing device is controlled by the control device 40 in the following
manner:
When the thickness of the thin sheet Wa (see Fig. 10) with a sheet thickness less
than a given value is inputted by the sheet thickness input unit 41, the valve 36
interposed in the piping 34b is closed to stop the blowing of air from the discharge
nozzles 33 of the air discharge pipe 32, whereas pressurized air is gushed from the
discharge holes 31a of the air discharge duct 31.
[0044] That is, in accordance with the distance to the thin sheet Wa measured by the displacement
gauge 42 (indicating the amount of floating of the sheet), the pump drive motor 43
for the blower pump 35 is drivingly controlled, and the frequency to the pump drive
motor 43 is boosted to increase the flow rate of air so that the thin sheet Wa is
moved, for example, from a sheet motion instability position (NG position) indicated
by a long dashed double-dotted line to a proper position (OK position) indicated by
a solid line in Fig. 10.
[0045] In the case of the thin sheet Wa, as seen above, pressurized air is gushed only from
the discharge holes 31a of the air discharge duct 31. Thus, the thin sheet Wa is pressed
uniformly against the circumferential surface of the impression cylinder 3b and transported
in a stable state. In other words, wrinkles or the like due to local pressurization
by an air jet from the discharge nozzles 33 do not occur.
[0046] When the thickness of the thick sheet Wb (see Fig. 11) with a sheet thickness of
the given value or more is inputted by the sheet thickness input unit 41, the valve
36 interposed in the piping 34b is opened to gush pressurized air from the discharge
nozzles 33 of the air discharge pipe 32 and also gush pressurized air from the discharge
holes 31a of the air discharge duct 31.
[0047] That is, in accordance with the distance to the thick sheet Wb measured by the displacement
gauge 42 (indicating the amount of floating of the sheet), the pump drive motor 43
for the blower pump 35 is drivingly controlled, and the frequency to the pump drive
motor 43 is boosted or lowered to increase or decrease the flow rate of air so that
the thick sheet Wb is moved, for example, from a sheet motion instability position
(NG position excessively separated from the impression cylinder 3b) indicated by a
long dashed double-dotted line or an improper position (NG position excessively close
to the impression cylinder 3b) indicated by another long dashed double-dotted line
to a proper position (OK position) indicated by a solid line in Fig. 11.
[0048] In detail, when the thick sheet Wb is located at the NG position excessively separated
from the impression cylinder 3b, the frequency to the pump drive motor 43 is boosted
to increase the flow rate of air. When the thick sheet Wb is located at the NG position
excessively close to the impression cylinder 3b, by contrast, the frequency to the
pump drive motor 43 is lowered to decrease the flow rate of air. The reason why NG
is given when the thick sheet Wb becomes too close to the impression cylinder 3b is
as follows : When the thick sheet Wb passes the air blowing device and is freed from
the gush of the pressurized air, the thick sheet Wb has a possibility to rebound greatly
because of its own elasticity, eventually causing the same state as the unstable motion
of the sheet. To avoid this situation, a position which enables the above rebound
to be suppressed as much as possible and which fits the contour of the impression
cylinder 3b as much as possible is set as the above-mentioned proper position (OK
position). The distance defined by the above proper position (OK position) of the
thick sheet Wb, namely, the distance for preventing the unstable motion of the thick
sheet Wb, is shorter than the distance defined by the aforementioned proper position
(OK position) of the thin sheet Wa, namely, the distance for preventing the unstable
motion of the thin sheet Wa.
[0049] Because of the above features, for the thick sheet Wb, a combination of pressurized
air from the discharge holes 31a of the air discharge duct 31 and pressurized air
from the discharge nozzles 33 of the air discharge pipe 32 presses the thick sheet
Wb against the circumferential surface of the impression cylinder 3b as strongly as
possible, and can thereby suppress the fluttering or unstable motion of the sheet.
The control device 40 may judge the sheet as the thin sheet Wa when the thickness
of the sheet inputted by the sheet thickness input unit 41 is the given value or higher,
and may judge the sheet as the thick sheet Wb when the thickness of the sheet inputted
by the sheet thickness input unit 41 exceeds the given value.
[0050] According to the present embodiment, as described above, the unstable motion of the
sheet is detected by the displacement gauge 42, and the air blowing device is controlled
automatically, whereby the flow rate of air can be adjusted appropriately. Thus, the
unstable motion of the sheet can be fully suppressed, and the printing sheet can be
transported stably. Hence, even a little experienced operator can do printing with
a sense of security. Since a printing trouble due to the unstable motion of the sheet
does not occur, the rate of operation of the machine is increased, and waste sheets
are also decreased.
[0051] For example, even for the thin sheet Wa, pressurized air may be gushed from the nozzles
33, depending on the paper quality of the sheet or the like. Nor is it necessary to
gush pressurized air from the nozzles 33 toward the thick sheet Wb, depending on its
paper quality or the like. Moreover, the blower pump 35 may be provided for each of
the pipings 34a and 34b, and the respective blower pumps 35 may be controlled independently.
[0052] Furthermore, the plate-shaped guides 22a, 22b may each be configured to have a flat
leading end surface without the notches 27a, 27b over the sheet width direction of
the printing sheet. Alternatively, there may be a configuration in which a plurality
of rod-shaped guides are arranged parallel in the sheet width direction of the printing
sheet, instead of the plate-shaped guides 22a, 22b. There may also be a configuration
in which the plate-shaped guides 22a, 22b or the rod-shaped guides each have the front
extremity in a semispherical or arcuate shape. The plate-shaped guides 22a, 22b may
each be composed of a plurality of plates each having a strip-shaped leading end portion,
rather than a one-piece plate having the notches 27a, 27b. The transport cylinder
is not limited to the impression cylinder, and may be a blanket cylinder having a
means for holding a sheet, such as a gripper device. The means for holding the sheet
is not limited to the gripper, and may be a suction-attracting pad.
[0053] The sheet guide apparatus according to the present invention can be applied even
to a sheet which is not a printing sheet, but a film, and can also be applied to a
coater for coating the sheet.
[Reference Signs List]
[0054]
1 Bed
2 Frame
3a, 3b Impression cylinder
4 Transfer cylinder
5 Gripper device (paper gripping device)
6 Blanket cylinder
7A First guide device
7B Second guide device
8a, 8b Air discharge duct
10a, 10b Stay
11a, 11b Holder
12a, 12b Block
13a, 13b Bar
14 Bolt
15a, 15b Guide plate
16 Air jet hole
17a, 17b Piping
18 Collecting piping
19 Blower pump
20a, 20b Subframe
21a, 21b Bar
22a, 22b Plate-shaped resinous guide
27a, 27b Notch
30a, 30b L-shaped bracket
31 Air discharge duct
31a Discharge hole
32 Air discharge pipe
33 Discharge nozzle
34a, 34b Piping
35 Blower pump
36 Valve
40 Control device
41 Sheet thickness input unit
42 Displacement gauge
43 Pump drive motor
P1, P2 Transfer position of printing sheet
S Movement trajectory of gripper device
Wa Thin sheet
Wb Thick sheet
1. A sheet guide apparatus including :
a transport cylinder (3b) having holding means (5) for holding a sheet (Wa, Wb) and
adapted to transport the sheet;
air blowing means (31, 33) for blowing air on the sheet being transported by the transport
cylinder;
detection means (42) for detecting a distance to the sheet being transported by the
transport cylinder; and
control means (40) for controlling the air blowing means, based on detection results
of the detection means, such that the distance between the sheet and the detection
means becomes a distance which prevents an unstable motion of the sheet;
characterized in that :
the distance which prevents the unstable motion of the sheet when the sheet is a thick
sheet (Wb) is a distance from a position between a sheet motion instability position
and an improper position to the detection means;
the sheet motion instability position being a position at which the sheet is excessively
separated from the transport cylinder (3b);
the improper position being a position at which the sheet is excessively close to
the transport cylinder (3b); and in that
when the sheet is a thick sheet (Wb), the control means controls the air blowing means
to increase the flow rate of air from the air blowing means if the sheet is excessively
separated from the transport cylinder (3b), and the control means controls the air
blowing means to decrease the flow rate of air from the air blowing means if the sheet
is excessively close to the transport cylinder (3b).
2. The sheet guide apparatus according to claim 1, characterized in that
the control means (40) controls the air blowing means to adjust a flow rate of discharged
air so that the distance between the sheet and the detection means becomes a set distance.
3. The sheet guide apparatus according to claim 1, characterized in that
the distance which prevents the unstable motion of the sheet differs according to
whether the sheet is a thin sheet (Wa) or a thick sheet (Wb).
4. The sheet guide apparatus according to claim 3, characterized in that
the distance, which prevents the unstable motion of the thick sheet when the sheet
is the thick sheet, is shorter than the distance which prevents the unstable motion
of the thin sheet when the sheet is the thin sheet.
5. The sheet guide apparatus according to claim 1, characterized in that
the detection means (42) is provided on a downstream side in a sheet transport direction
with respect to the air blowing means (31, 33) and on an upstream side in the sheet
transport direction with respect to a cylinder (6) in contact with the transport cylinder.
6. The sheet guide apparatus according to claim 1, characterized in that
the detection means (42) is provided at a position opposing a surface of the sheet
(Wa, Wb).
7. The sheet guide apparatus according to claim 1, further comprising
a sheet thickness input unit (41) for inputting a thickness of the sheet (Wa, Wb),
and wherein
the control means (40) judges the sheet as a thin sheet when the thickness of the
sheet inputted by the sheet thickness input unit is less than a given value, and judges
the sheet as a thick sheet when the thickness of the sheet inputted by the sheet thickness
input unit is the given value or higher.
8. The sheet guide apparatus according to claim 1, further comprising
a sheet thickness input unit (41) for inputting a thickness of the sheet (Wa, Wb),
and wherein
the control means (40) judges the sheet as a thin sheet when the thickness of the
sheet inputted by the sheet thickness input unit is a given value or lower, and judges
the sheet as a thick sheet when the thickness of the sheet inputted by the sheet thickness
input unit exceeds the given value.
9. The sheet guide apparatus according to claim 1, characterized in that
the air blowing means includes an air discharge duct (31) having discharge holes (31a),
and discharge nozzles (33), and
the control means (40) exercises control such that air is discharged from the discharge
holes of the air discharge duct and the discharge nozzles when the sheet is a thick
sheet (Wb), and exercises control such that air is discharged only from the discharge
holes of the air discharge duct when the sheet is a thin sheet (Wa).
10. The sheet guide apparatus according to claim 1, characterized in that the detection means is a displacement gauge (42).
1. Bogenführungsvorrichtung mit:
einem Transportzylinder (3b), der eine Halteeinrichtung (5) zum Halten eines Bogens
(Wa, Wb) aufweist und ausgestaltet ist, um den Bogen zu transportieren;
einer Luftblaseinrichtung (31, 33) zum Blasen von Luft auf den Bogen, der durch den
Transportzylinder transportiert wird;
einer Erfassungseinrichtung (42) zum Erfassen einer Distanz zum Bogen, der durch den
Transportzylinder transportiert wird; und
einer Steuereinrichtung (40) zum Steuern der Luftblaseinrichtung, basierend auf den
Erfassungsergebnissen der Erfassungseinrichtung, so dass die Distanz zwischen dem
Bogen und der Erfassungseinrichtung eine Distanz wird, bei der eine instabile Bewegung
des Bogens verhindert wird;
dadurch gekennzeichnet, dass:
die Distanz, bei der die instabile Bewegung des Bogens verhindert wird, wenn der Bogen
ein dicker Bogen (Wb) ist, eine Distanz von einer Position zwischen einer instabilen
Bogenbewegungsposition und einer unzulässigen Position relativ zur Erfassungseinrichtung
ist;
die instabile Bogenbewegungsposition eine Position ist, bei der der Bogen übermäßig
vom Transportzylinder (3b) separiert ist;
die unzulässige Position eine Position ist, bei der sich der Bogen übermäßig nahe
am Transportzylinder (3b) befindet; und dass
wenn der Bogen ein dicker Bogen (Wb) ist, die Steuereinrichtung die Luftblaseinrichtung
steuert, um die Luftströmungsrate von der Luftblaseinrichtung zu erhöhen, wenn der
Bogen übermäßig vom Transportzylinder (3b) separiert ist, und die Steuereinrichtung
die Luftblaseinrichtung steuert, um die Luftströmungsrate von der Luftblaseinrichtung
zu verringern, wenn sich der Bogen übermäßig nahe am Transportzylinder (3b) befindet.
2. Bogenführungsvorrichtung nach Anspruch 1, dadurch gekennzeichnet, dass die Steuereinrichtung (40) die Luftblaseinrichtung steuert, um die Strömungsrate
der ausgegebenen Luft so einzustellen, dass die Distanz zwischen dem Bogen und der
Erfassungseinrichtung eine eingestellte Distanz wird.
3. Bogenführungsvorrichtung nach Anspruch 1, dadurch gekennzeichnet, dass die Distanz, bei der die instabile Bewegung des Bogens verhindert wird, abhängig
davon differiert, ob der Bogen ein dünner Bogen (Wa) oder ein dicker Bogen (Wb) ist.
4. Bogenführungsvorrichtung nach Anspruch 3, dadurch gekennzeichnet, dass die Distanz, bei der die instabile Bewegung des dicken Bogens verhindert wird, wenn
der Bogen der dicke Bogen ist, kleiner ist als die Distanz, bei der die instabile
Bewegung des dünnen Bogens verhindert wird, wenn der Bogen der dünne Bogen ist.
5. Bogenführungsvorrichtung nach Anspruch 1, dadurch gekennzeichnet, dass die Erfassungseinrichtung (42) in einer Bogentransportrichtung an einer stromabwärts
gelegenen Seite bezüglich der Luftblaseinrichtung (31, 33) und in der Bogentransportrichtung
an einer stromaufwärts gelegenen Seite bezüglich eines Zylinders (6) vorgesehen ist,
der mit dem Transportzylinder in Kontakt steht.
6. Bogenführungsvorrichtung nach Anspruch 1, dadurch gekennzeichnet, dass die Erfassungseinrichtung (42) an einer Position gegenüber einer Fläche des Bogens
(Wa, Wb) vorgesehen ist.
7. Bogenführungsvorrichtung nach Anspruch 1, außerdem mit
einer Bogendickeneingabeeinheit (41) zum Eingeben einer Dicke des Bogens (Wa, Wb),
und wobei
die Steuereinrichtung (40) den Bogen als einen dünnen Bogen einstuft, wenn die Dicke
des Bogens, die durch die Bogendickeneingabeeinheit eingegeben wird, kleiner ist als
ein gegebener Wert, und den Bogen als einen dicken Bogen einstuft, wenn die Dicke
des Bogens, die durch die Bogendickeneingabeeinheit eingegeben wird, der gegebene
Wert oder größer ist.
8. Bogenführungsvorrichtung nach Anspruch 1, außerdem mit
einer Bogendickeneingabeeinheit (41) zum Eingeben einer Dicke des Bogens (Wa, Wb),
und wobei
die Steuereinrichtung (40) den Bogen als einen dünnen Bogen einstuft, wenn die Dicke
des Bogens, die durch die Bogendickeneingabeeinheit eingegeben wird, ein gegebener
Wert oder kleiner ist, und den Bogen als einen dicken Bogen einstuft, wenn die Dicke
des Bogens, die durch die Bogendickeneingabeeinheit eingegeben wird, den gegebenen
Wert überschreitet.
9. Bogenführungsvorrichtung nach Anspruch 1, dadurch gekennzeichnet, dass
die Luftblaseinrichtung einen Luftauslasskanal (31) mit Auslasslöchern (31a) und Auslassdüsen
(33) aufweist, und
die Steuereinrichtung (40) die Steuerung so durchführt, dass Luft aus den Auslasslöchern
des Luftauslasskanals und den Auslassdüsen ausgegeben wird, wenn der Bogen ein dicker
Bogen (Wb) ist, und die Steuerung so durchführt, dass Luft nur aus den Auslasslöchern
des Luftauslasskanals ausgegeben wird, wenn der Bogen ein dünner Bogen (Wa) ist.
10. Bogenführungsvorrichtung nach Anspruch 1, dadurch gekennzeichnet, dass die Erfassungseinrichtung eine Verlagerungsmessgerät (42) ist.
1. Dispositif de guidage de feuilles comprenant :
un cylindre de transport (3b) comportant un moyen de maintien (5) pour tenir une feuille
(Wa, Wb) et adapté pour transporter la feuille ;
un moyen de soufflage d'air (31, 33) pour envoyer de l'air sur la feuille transportée
par le cylindre de transport ;
un moyen de détection (42) pour détecter une distance à la feuille transportée par
le cylindre de transport ; et
un moyen de commande (40) pour commander le moyen de soufflage d'air en se basant
sur les résultats de détection du moyen de détection, de telle manière que la distance
entre la feuille et le moyen de détection devient égale à une distance qui empêche
un mouvement instable de la feuille ;
caractérisé en ce que :
la distance qui empêche le mouvement instable de la feuille quand la feuille est une
feuille épaisse (Wb) est une distance depuis une position située entre une position
d'instabilité de mouvement de feuille et une position incorrecte par rapport au moyen
de détection ;
la position d'instabilité de mouvement de feuille étant une position dans laquelle
la feuille est excessivement distante du cylindre de transport (3b) ;
la position incorrecte étant une position dans laquelle la feuille est excessivement
proche du cylindre de transport (3b) ; et en ce que
quand la feuille est une feuille épaisse (Wb), le moyen de commande commande le moyen
de soufflage d'air pour augmenter le débit d'air du moyen de soufflage d'air si la
feuille est excessivement distante du cylindre de transport (3b), et le moyen de commande
commande le moyen de soufflage d'air pour diminuer le débit d'air du moyen de soufflage
d'air si la feuille est excessivement proche du cylindre de transport (3b).
2. Dispositif de guidage de feuilles selon la revendication 1, caractérisé en ce que le moyen de commande (40) commande le moyen de soufflage d'air pour régler un débit
d'air refoulé de telle manière que la distance entre la feuille et le moyen de détection
devient égale à une distance choisie.
3. Dispositif de guidage de feuilles selon la revendication 1, caractérisé en ce que la distance qui empêche le mouvement instable de la feuille diffère selon que la
feuille est une feuille mince (Wa) ou une feuille épaisse (Wb).
4. Dispositif de guidage de feuilles selon la revendication 3, caractérisé en ce que la distance qui empêche le mouvement instable de la feuille épaisse quand la feuille
est la feuille épaisse est inférieure à la distance qui empêche le mouvement instable
de la feuille mince quand la feuille est la feuille mince.
5. Dispositif de guidage de feuilles selon la revendication 1, caractérisé en ce que le moyen de détection (42) est placé d'un côté aval dans une direction de transport
de feuille par rapport au moyen de soufflage d'air (31, 33) et d'un côté amont dans
la direction de transport de feuille par rapport à un cylindre (6) en contact avec
le cylindre de transport.
6. Dispositif de guidage de feuilles selon la revendication 1, caractérisé en ce que le moyen de détection (42) est placé en une position opposée à une surface de la
feuille (Wa, Wb).
7. Dispositif de guidage de feuilles selon la revendication 1, comprenant en outre :
une unité de saisie d'épaisseur de feuille (41) pour entrer une épaisseur de la feuille
(Wa, Wb), et dans lequel
le moyen de commande (40) détermine que la feuille est une feuille mince quand l'épaisseur
de la feuille saisie dans l'unité de saisie d'épaisseur de feuille est inférieure
à une valeur donnée, et détermine que la feuille est une feuille épaisse quand l'épaisseur
de la feuille saisie dans l'unité de saisie d'épaisseur de feuille est supérieure
ou égale à la valeur donnée.
8. Dispositif de guidage de feuilles selon la revendication 1, comprenant en outre :
une unité de saisie d'épaisseur de feuille (41) pour entrer une épaisseur de la feuille
(Wa, Wb), et dans lequel
le moyen de commande (40) détermine que la feuille est une feuille mince quand l'épaisseur
de la feuille saisie dans l'unité de saisie d'épaisseur de feuille est inférieure
ou égale à une valeur donnée, et détermine que la feuille est une feuille épaisse
quand l'épaisseur de la feuille saisie dans l'unité de saisie d'épaisseur de feuille
est supérieure à la valeur donnée.
9. Dispositif de guidage de feuilles selon la revendication 1,
caractérisé en ce que :
le moyen de soufflage d'air comprend un conduit de refoulement d'air (31) comportant
des trous de refoulement (31a), et des buses de refoulement (33), et
le moyen de commande (40) effectue une commande de telle manière que de l'air est
refoulé par les trous de refoulement du conduit de refoulement d'air et les buses
de refoulement quand la feuille est une feuille épaisse (Wb), et effectue une commande
de telle manière que l'air n'est refoulé que par les trous de refoulement du conduit
de refoulement d'air quand la feuille est une feuille mince (Wa).
10. Dispositif de guidage de feuilles selon la revendication 1, caractérisé en ce que le moyen de détection est un capteur de déplacement (42).