U.S. patent application number 11/544730 was filed with the patent office on 2007-02-08 for calender for a sheet of paper.
This patent application is currently assigned to MITSUBISHI HEAVY INDUSTRIES, LTD.. Invention is credited to Junichi Ibushi, Takeshi Matsuo, Hatsuo Mori, Fujio Shinoki, Setsuo Suzuki.
Application Number | 20070028786 11/544730 |
Document ID | / |
Family ID | 26624475 |
Filed Date | 2007-02-08 |
United States Patent
Application |
20070028786 |
Kind Code |
A1 |
Suzuki; Setsuo ; et
al. |
February 8, 2007 |
Calender for a sheet of paper
Abstract
A calender for a sheet of paper comprising a metal roll which is
rotated by a first driving unit. The calender further comprises a
rotatable cylindrical jacket, a pressurizing shoe, and a plurality
of support members. The cylindrical jacket is disposed opposite the
metal roll to form a calender nip so that the sheet of paper is
continuously passed through the calender nip. The pressurizing shoe
is provided within the jacket at the position of the calender nip
and presses the interior surface of the jacket radially outward to
pressurize the calender nip. The support members are disposed
inside the jacket so that they are equally balanced in the
peripheral direction of the jacket.
Inventors: |
Suzuki; Setsuo;
(Hiroshima-ken, JP) ; Matsuo; Takeshi;
(Hiroshima-ken, JP) ; Ibushi; Junichi;
(Hiroshima-ken, JP) ; Mori; Hatsuo;
(Hiroshima-ken, JP) ; Shinoki; Fujio;
(Hiroshima-ken, JP) |
Correspondence
Address: |
ARMSTRONG, KRATZ, QUINTOS, HANSON & BROOKS, LLP
1725 K STREET, NW
SUITE 1000
WASHINGTON
DC
20006
US
|
Assignee: |
MITSUBISHI HEAVY INDUSTRIES,
LTD.
Tokyo
JP
|
Family ID: |
26624475 |
Appl. No.: |
11/544730 |
Filed: |
October 10, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10944747 |
Sep 21, 2004 |
7134388 |
|
|
11544730 |
Oct 10, 2006 |
|
|
|
10291800 |
Nov 12, 2002 |
6837157 |
|
|
10944747 |
Sep 21, 2004 |
|
|
|
Current U.S.
Class: |
100/155R |
Current CPC
Class: |
D21G 1/00 20130101; D21G
1/0066 20130101; D21G 1/006 20130101 |
Class at
Publication: |
100/155.00R |
International
Class: |
D21G 1/02 20060101
D21G001/02 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 12, 2001 |
JP |
2001-345878 |
Sep 30, 2002 |
JP |
2002-285832 |
Claims
1. A calender for a sheet of paper comprising: a metal roll which
is rotated by a first driving unit; a rotatable cylindrical jacket
disposed opposite said metal roll to form a calender nip so that
the sheet of paper is continuously passed through said calender
nip; a pressurizing shoe, provided within said jacket at the
position of said calender nip, for pressing the interior surface of
said jacket radially outward to pressurize said calender nip; and a
plurality of support members disposed inside said jacket so that
they are equally balanced in the peripheral direction of said
jacket; wherein each of said support members comprises a shoe; and
at the position opposite to one of said support shoes through said
jacket, there is provided a driving roll which is pressed against
said jacket to rotate said jacket, wherein said one support shoe
comprises a plurality of divided type shoes divided an axial
direction.
2. The calender as set forth in claim 1, wherein a surface of said
support shoe is provided with grooves which extend in a direction
where said jacket rotates.
3. The calender as set forth in claim 1, wherein a surface of said
support shoe is provided with grooves which extend obliquely with
respect to a direction where said jacket rotates.
Description
[0001] (This application is a divisional application of Ser. No.
10/944,747, filed Sep. 21, 2004, which was a divisional application
of Ser. No. 10/291,800, filed Nov. 12, 2002, now U.S. Pat. No.
6,837,157).
BACKGROUND OF THE INVENTION
[0002] (1) Field of the Invention
[0003] The present invention relates generally to a calender for a
sheet of paper, and more particularly to a calender which performs
a surface process on paper after it is dried by a drier, to make it
smooth and glossy.
[0004] (2) Description of the Related Art
[0005] In paper mills, a layer of paper made by a paper-making
section is pressed to remove water by a press. Then, the paper is
heated and dried. Next, a calender is employed as a machine in
which paper is pressed by rollers to glaze or smooth it.
[0006] Typical examples of calenders are a chilled nip calender, a
soft nip calender, and a shoe calender. The chilled nip calender is
equipped with chilled metal rolls to form at least one pair of
nips. The soft nip calender is constructed of a metal roll and an
elastic resin roll. In the soft nip calender, only a pair of nips
is formed on the periphery of the resin roll. The shoe calender is
constructed of a metal roll, a tube sleeve disposed opposite the
metal roll and a shoe which is inside of the tube sleeve. The shoe
is pressed against the inner periphery of the sleeve to form a
nip.
[0007] Since the present invention relates to the above-described
shoe calender, two conventional shoe calenders will hereinafter be
described with reference to FIGS. 13 to 17.
[0008] FIGS. 13 and 14 show a first conventional shoe calender
described in patent reference 1. The conventional shoe calender is
constructed of an upper half part including a metal roll 10, and a
lower half part including a cylindrical stationary beam 1, a sleeve
2, etc. The cylindrical stationary beam 1 is fixedly attached to a
support leg 11. The outer periphery of the stationary beam 1 is
provided with guide members 8 at suitable intervals with respect to
the center of the stationary beam 1.
[0009] A sleeve 12 is provided to cover the cylindrical stationary
beam 1 and rotatably supported by the guide members 8. The opposite
ends of the sleeve 12 are further supported by clamp discs 9 to
make the interior airtight.
[0010] In the conventional shoe calender constructed as described
above, when a paper sheet 15 is calendered, the lower half part of
the calender with the sleeve 2 is brought into contact with the
peripheral surface of the metal roll 10 through the paper sheet 15,
as shown in FIG. 13. The sleeve 2 is pressurized by applying
pressurized oil to the pressurizing shoe 3 and utilizing the
deformation of the sleeve 2 that develops when the sleeve 2 is
pressed radially outward.
[0011] The stationary beam 1 is further provided with
lubricating-oil supply passages 4, 5 and lubricating-oil collection
passages 6, 7. The first lubricating-oil supply passage 4 is
connected to the lower portion of the pressurizing shoe 3 so that
pressurizing force is applied to the pressurizing shoe 3. The
second lubricating-oil supply passage 5 is opened at the outer
periphery of the stationary beam 1 so that lubricating oil can be
supplied to the inner periphery of the sleeve 2.
[0012] FIGS. 15 through 17 show a second conventional shoe calender
described in patent reference 2. The conventional shoe calender is
basically the same in construction as the first conventional shoe
calender shown in FIGS. 13 and 14. As in the first conventional
shoe calender, a flexible jacket 32 is pressed against a metal roll
10 to calender a paper sheet 15.
[0013] That is, to calender the paper sheet 15, a shoe roll 30 is
pressed against the metal roll 10 by a pressurizing shoe 18
provided inside the flexible jacket 32. Reference numeral 95
denotes a pressurizing unit for the metal roll 10. Reference
numeral 34 denotes a support beam for the pressurizing shoe 18, and
20 denotes a pressurizing unit.
[0014] As shown in FIG. 16, the opposite ends of the flexible
jacket 32 are fixed to end plates 24, 26. If the pressurizing unit
20 is actuated, the pressurizing shoe 18 projects in the radial
direction of the flexible jacket 32 and deforms the flexible jacket
32. As a result, the paper sheet 15 is pressurized between the
metal roll 10 and the flexible jacket 32.
[0015] In the conventional shoe calender shown in FIGS. 13 and 14,
the sleeve 2 is rotated by the rotational force of the metal roll
10 which is rotated by a driving unit (not shown). Because of this,
if the pressurizing force of the pressurizing shoe 3 is weak, the
transmission of the rotational force will be insufficient, and
consequently, the sleeve 2 will slip easily. Conversely, if it is
strong, the friction between the pressurizing shoe 3 and the sleeve
2 will increase. As a result, heat will be generated and the sleeve
2 will be elliptically deformed.
[0016] Hence, the shoe calender is provided with the
lubricating-oil supply passages 5, and lubricating oil is supplied
to the inner periphery of the sleeve 2 to prevent generation of
heat and perform lubrication. In addition, the guide members 8 are
disposed inside the sleeve 2 to prevent deformation of the sleeve
2.
[0017] However, if the pressurizing force reaches a predetermined
value or greater, deformation of the sleeve 2 will become great and
therefore gaps will be produced between the guide member 8 and the
sleeve 2. As a result, the effect of the guide members 8 will no
longer be obtained.
[0018] Because of the gaps between the guide members 8 and the
sleeve 2, the sleeve 2 is insufficiently supported and therefore
vibrates. As a result, there is a problem that because of the
vibration, the trace of vibration will occur in the paper sheet
15.
[0019] In chilled nip calenders, incidentally, paper is passed
between rolls in contact with each other. However, in soft nip
calenders, if a rubber roll is contacted with a high-temperature
metal roll without paper, the rubber will degrade. Because of this,
the rubber roll is held away from the metal roll until paper is
passed through. After paper is passed through, the rubber roll is
pressed against the metal roll through the paper.
[0020] On the other hand, in the conventional shoe calender (patent
reference 1), the sleeve 2 is of a driven type. That is, the sleeve
2 is rotated by contacting with the metal roll 10. In this shoe
calender, as with chilled nip calenders, paper is passed between
the sleeve 2 and the metal roll 10 after the sleeve 2 is contacted
with the metal roll 10. Because of this, before paper is passed
through, the outer periphery of the sleeve 2 is contacted directly
with the high-temperature metal roll 10.
[0021] However, since the outer periphery of the sleeve 2 of the
shoe calender is constructed of elastic synthetic resin, if the
sleeve 2 of the shoe calender is exposed to high temperature for a
long time and rises in temperature, then the quality will degrade
and the life will be shortened. Particularly, in such a shoe
calender, the nip passage time is long and therefore the contact
area (i.e., contact time) between the outer periphery of the sleeve
2 and the metal roll 10 is long. As a result, the temperature of
the outer periphery of the sleeve 2 becomes considerably high.
[0022] To prevent the problem of high temperature, it is
contemplated that the sleeve 2 is held away from the metal roll 10
until paper is passed through. In soft nip calenders, such a
process is often performed. However, since the sleeve 2 in the
conventional shoe calender (patent reference 1) has no driving
unit, the sleeve 2 will no longer rotate if it is moved away from
the metal roll 10. Therefore, in the case where the sleeve 2 is
contacted with the metal roll 10 after paper is passed through, it
is necessary to contact the sleeve 2 with the metal roll 10 being
rotated. In such a case, paper is broken as soon as the sleeve 2
not being rotated is contacted with paper.
[0023] Therefore, in the conventional shoe calender, the sleeve 2
must be held in contact with the metal roll 10 during operation. As
a result, the outer periphery of the sleeve 2, which is constructed
of a material whose heat-resisting temperature is low (e.g.,
polyurethane), will reach a considerably high temperature and
degrade quickly.
[0024] In the conventional shoe calender shown in FIG. 17, the
flexible jacket 32 can rotate. That is, the end plate 24 or 26 is
driven by a driving unit (not shown). A gear 56 is rotated by a
driving shaft 48. In this way, the flexible jacket 32 is rotated.
Since the moving speed of the paper sheet 15 can be synchronized
with the rotational speed of the flexible jacket 32, breaking of
the paper sheet 15 can be reduced.
[0025] However, as with the conventional shoe calender shown in
FIGS. 13 and 14, the pressurizing shoe 18 contacts with the metal
roll 10 at one point on the flexible jacket 32. Therefore, in
combination with centrifugal force, etc., the flexible jacket 32 is
elliptically deformed when it rotates.
[0026] That is, since the flexible jacket 32 is supported only at
the position of the pressurizing shoe 18, deformation of the
flexible jacket 32 becomes great and it rotates elliptically.
Because of this, vibration is generated by rotation and the runout
of the jacket 32 occurs. Thus, the calender cannot be operated at a
high speed.
SUMMARY OF THE INVENTION
[0027] The present invention has been made in view of the
above-described circumstances. Accordingly, it is an object of the
present invention to provide a calender that is capable of
preventing the elliptical deformation of a flexible jacket or
cylindrical sleeve (jacket) due to pressurization and thereby
preventing vibration which will develop due to the deformation.
Another object of the invention is to provide a calender which is
capable of suppressing a rise in temperature of the outer periphery
of the sleeve member (jacket) to suppress heat degradation.
[0028] To achieve the objects of the present invention and in
accordance with first means of the invention, there is provided a
calender for a sheet of paper comprising a metal roll which is
rotated by a first driving unit. The calender further comprises a
rotatable cylindrical jacket, a pressurizing shoe, and a plurality
of support members. The cylindrical jacket is disposed opposite the
metal roll to form a calender nip so that the sheet of paper is
continuously passed through the calender nip. The pressurizing shoe
is provided within the jacket at the position of the calender nip
and presses the interior surface of the jacket radially outward to
pressurize the calender nip. The support members are disposed
inside the jacket so that they are equally balanced in the
peripheral direction of the jacket.
[0029] According to the first means, a plurality of support members
are disposed inside the jacket so that they are equally balanced in
the peripheral direction of the jacket. With the support members
equally balanced in the peripheral direction of the jacket,
deformation of the jacket due to rotation of the jacket can be
prevented, and the occurrence of vibration due to the jacket
deformation can be prevented.
[0030] In accordance with second means of the present invention,
each of the support members comprises a shoe. At the position
opposite to one of the support shoes through the jacket, there is
provided a driving roll which is pressed against the jacket to
rotate the jacket.
[0031] According to the second means, in addition to the support
members equally balanced in the peripheral direction of the jacket,
the driving roll is disposed at the position opposite to the
support shoe through the jacket. Since the jacket is supported at
the inner and outer peripheries, deformation during rotation is
reliably prevented. In addition, because the jacket is rotated by
the driving roll, driving force is assured even if there is a gap
between the metal roll and the jacket when a sheet of paper is
passed between the metal roll and the jacket. As a result, a sheet
of paper can be easily passed between the metal roll and the
jacket.
[0032] In accordance with third means of the present invention, the
support shoe comprises a plurality of divided type shoes divided an
axial direction.
[0033] According to the third means, the support shoe is divided
into small shoes. As a result, the contact area between the support
shoes and the jacket is reduced and the friction resistance is
reduced. Therefore, the driving load of the second driving unit can
be reduced and the power of the second driving unit can be
saved.
[0034] In accordance with fourth means of the present invention, a
surface of the support shoe is provided with grooves which extend
in a direction where the jacket rotates.
[0035] Since the support shoe is provided with grooves which
extends in a direction where the jacket rotates, the lubricating
oil that is sprayed inside the jacket flows through the grooves. As
a result, there is no possibility that the lubricating oil will
stay in the bottom of the jacket. Thus, the jacket is more smoothly
rotated.
[0036] In accordance with fifth means of the present invention, a
surface of the support shoe is provided with grooves which extend
obliquely with respect to a direction where the jacket rotates.
[0037] Since the support shoe is provided with oblique grooves, the
lubricating oil that is sprayed inside the jacket flows through the
oblique grooves. As a result, there is no possibility that the
lubricating oil will stay in the bottom of the jacket. Thus, the
jacket is more smoothly rotated.
[0038] In accordance with sixth means of the present invention, one
of the support members comprises a rotatable roll. At the position
opposite to the support roll through the jacket, there is provided
a driving roll which is pressed against the jacket to rotate the
jacket.
[0039] In addition to the support members equally balanced in the
peripheral direction of the jacket, the driving roll is disposed at
the position opposite to the support shoe through the jacket. Since
the jacket is supported at the inner and outer peripheries,
deformation during rotation is reliably prevented. In addition,
because the jacket is rotated by the driving roll, driving force is
assured even if there is a gap between the metal roll and the
jacket when a sheet of paper is passed between the metal roll and
the jacket. As a result, a sheet of paper can be easily passed
between the metal roll and the jacket. Furthermore, since the
support member is constructed of a rotatable roll, the friction
resistance with the jacket is reduced. As a result, the driving
load of the second driving unit can be reduced and power can be
saved.
[0040] In accordance with seventh means of the present invention,
the support roll comprises a plurality of divided type rolls
divided an axial direction.
[0041] Since the support roll is divided into small rolls, the
contact area between the support rolls and the jacket is reduced
and the friction resistance is reduced. Therefore, the driving load
of the second driving unit can be reduced and the power of the
second driving unit can be saved.
[0042] In accordance with eighth means of the present invention,
the outer periphery of the support roll is provided with grooves
which extend in the peripheral direction.
[0043] Since the outer periphery of the support roll is provided
with grooves which extend in the circumferental direction, the
lubricating oil that is sprayed inside the jacket flows through the
grooves. As a result, there is no possibility that the lubricating
oil will stay in the bottom of the jacket. Thus, the jacket is more
smoothly rotated.
[0044] In accordance with ninth means of the present invention, the
outer periphery of the support roll is provided with grooves which
extend in spiral form.
[0045] Since the outer periphery of the support roll is provided
with spiral grooves, the lubricating oil that is sprayed inside the
jacket flows through the spiral grooves. As a result, there is no
possibility that the lubricating oil will stay in the bottom of the
jacket. Thus, the jacket is more smoothly rotated.
[0046] In accordance with tenth means of the present invention, the
driving roll comprises a plurality of divided type rolls divided in
an axial direction.
[0047] Because the driving roll is divided into small rolls, the
size is reduced. As a result, power of the driving motor for
rotating the driving roll can be saved.
[0048] In accordance with eleventh means of the present invention,
there is provided a doctor blade which abuts the jacket, at the
position opposite to one of the support members through the
jacket.
[0049] In addition to the support members equally balanced in the
peripheral direction of the jacket, the doctor blade is disposed at
the position opposite to the support shoe through the jacket.
Because the jacket is supported at the inner and outer peripheries,
deformation during rotation is reliably prevented. Furthermore,
since dust on the surface of the jacket is removed, the calender
effect can be further enhanced.
[0050] In accordance with twelfth means of the present invention,
the doctor blade comprises a plurality of divided type doctor
blades divided in an axial direction of the jacket.
[0051] Since the doctor blade is divided into small doctor blades,
the contact area between the doctor blades and the jacket is
reduced. Therefore, wear on the jacket can be saved.
[0052] In accordance with thirteenth means of the present
invention, the doctor blades are slidable in the axial direction of
the jacket.
[0053] Since the doctor blades are slidable in the axial direction
of the jacket, dust on the entire surface of the jacket can be
removed even if the contact area between the doctor blade and the
jacket is reduced. As a result, power can be saved and wear can be
prevented.
[0054] In accordance with fourteenth means of the present
invention, the calender further comprises (1) a roll-moving unit
for moving the jacket, the driving roll, and the doctor blade
between a first position where the jacket is pressed against the
metal roll and a second position where the jacket, the driving
roll, and the doctor blade are moved away from the metal roll, and
(2) a controller for controlling the roll-moving unit and a second
driving unit which drives the driving roll. The controller controls
the roll-moving unit so that until speed of the jacket is
synchronized with speed of the metal roll, the jacket is held at
the second position. The controller also controls speed of the
second driving unit so that the speed of the jacket is synchronized
with the speed of the metal roll. Furthermore, the controller
controls the roll-moving unit so that after the speed of the jacket
is synchronized with the speed of the metal roll, the jacket is
held at the first position. The controller performs drooping
control on the second driving unit after the jacket is held at the
first position.
[0055] According to the fourteenth means, the jacket is held at the
second position until speed of the jacket is synchronized with
speed of the metal roll. Therefore, heating of the jacket is
prevented and heat degradation is prevented. Furthermore, drooping
control is performed on the second driving unit after the jacket is
held at the first position. Therefore, a paper sheet can be stably
traveled.
[0056] In accordance with fifteenth means of the present invention,
the controller controls driving torque of the second driving unit
to perform load allotment control with the first driving unit as a
master side, after pressurization by the pressurizing shoe is
performed at the position of the calender nip. The controller
allots a load on the second driving unit to the first driving unit
and gradually reduces the driving torque of the second driving unit
to zero, if the load allotment between the first driving unit and
the second driving unit is stabilized.
[0057] According to the fifteenth means, the controller controls
driving torque of the second driving unit to perform load allotment
control with the first driving unit as a master side. The
controller gradually reduces the driving torque of the second
driving unit to zero. As a result, a sudden change in the driving
torque that is applied to a paper sheet of paper is avoided and
cutting of the paper sheet is prevented.
[0058] In accordance with sixteenth means of the present invention,
the controller disconnects the driving roll from the jacket after
the driving torque of the second driving unit is gradually reduced
to zero, and then stops the speed of the second driving unit.
[0059] Because the speed of the second driving unit is stopped, the
output load and control load of the second driving unit can be
saved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0060] FIG. 1 is a cross sectional view showing a calender
constructed in accordance with a first embodiment of the present
invention;
[0061] FIG. 2 is a diagrammatic rear view of the driving roll in
the first embodiment shown in FIG. 1;
[0062] FIG. 3 is a diagrammatic front view of the doctor blade in
the first embodiment shown in FIG. 1;
[0063] FIG. 4 is a diagram showing the driving roll of a calender
constructed in accordance with a second embodiment of the present
invention;
[0064] FIG. 5 is a diagram showing the doctor blade of a calender
constructed in accordance with a third embodiment of the present
invention;
[0065] FIG. 6 is a sectional view showing the support shoes of a
calender constructed in accordance with a fourth embodiment of the
present invention;
[0066] FIG. 7 is a cross sectional view showing a calender
constructed in accordance with a fifth embodiment of the present
invention;
[0067] FIGS. 8A and 8B are plan views showing the contact surfaces
of the support rolls of a calender constructed in accordance with a
sixth embodiment of the present invention;
[0068] FIG. 9 is a cross sectional view showing a calender
constructed in accordance with a seventh embodiment of the present
invention;
[0069] FIG. 10 is a diagram showing the support roll of the
calender of the seventh embodiment;
[0070] FIGS. 11A and 11B are plan views showing the contact
surfaces of the support rolls of a calender constructed in
accordance with an eighth embodiment of the present invention;
[0071] FIG. 12 is a sectional view showing the support roll of a
calender constructed in accordance with a ninth embodiment of the
present invention;
[0072] FIG. 13 is a cross sectional view showing a conventional
shoe calender;
[0073] FIG. 14 is a vertical sectional view showing the lower half
of the main body of the conventional shoe calender shown in FIG.
13;
[0074] FIG. 15 is a cross sectional view showing another
conventional shoe calender;
[0075] FIG. 16 is a vertical sectional view showing the
conventional shoe calender shown in FIG. 15; and
[0076] FIG. 17 is a perspective view showing the interior of the
shoe roll of the conventional shoe calender shown in FIG. 15.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0077] Referring now in greater detail to the drawings and
initially to FIGS. 1 through 3, there is shown a calender
constructed in accordance with a first embodiment of the present
invention. In the first embodiment, a rotatable metal roll 10 and a
pressurizing roll 100 are disposed at the opposite positions
through a paper sheet 15. The outer periphery of the pressurizing
roll 100 is provided with a resin jacket 101. Inside the jacket
101, there is provided a stationary base 102.
[0078] A recessed, pressurizing shoe 105 and support shoes 106 and
107 are provided on the base 102 for the purpose of forming a
pressuring nip (calender nip) for a calendering process. The
pressurizing shoe 105 and support shoes 106, 107 are disposed at
three positions shifted 120 degrees from each other so that they
are equally balanced. Note that the pressurizing force of the
pressurizing shoe 105 and the pressurizing forces of the support
shoes 106,107 can be independently adjusted.
[0079] The resin jacket 101 is supported at its outer periphery by
a driving roll 130 disposed opposite the second support shoe 107.
The resin jacket 101 is rotated by rotation of the driving roll
130.
[0080] A doctor blade 120 is disposed opposite the first support
shoe 106 shifted 120 degrees from the second support shoe 107, and
contacts the surface of the jacket 101 to remove paper dust
adhering to the surface of the jacket 101.
[0081] The driving roll 130, as shown in FIG. 2, extends over the
entire axial length of the pressurizing roll 100 and is rotated by
a driving motor 150. The rotation of the driving roll 130 causes
the pressurizing roll 100 to rotate.
[0082] The doctor blade 120, as shown in FIG. 3, is constructed of
a stationary doctor blade extending over the entire length of the
pressurizing roll 100. The doctor blade 120 abuts the surface of
the jacket 101 at the position opposite to the first support shoe
106 to hold the jacket 101.
[0083] In the above-described first embodiment, even when the
jacket 101 is protruded by the pressuring shoe 105 pressurized for
a calendering process, the support shoes 106, 107 protrude outward
in the radial direction of the jacket 101 at the same time so that
the circular shape of the jacket 101 is held.
[0084] In addition, even if the jacket 101 bulges due to
deformation caused by applied pressure and rotation, the driving
roll 130 and doctor blade 120 act on the outer periphery of the
jacket 101 to prevent deformation. As a result, the jacket 101 can
be held in a state near to a circle.
[0085] As shown in FIG. 2, the calender of the first embodiment is
equipped with a driving motor (second driving motor) 150 which
drives the driving roll 130 that rotates the jacket 100, and a
roll-moving unit 160 which moves the jacket 101 between a first
position where the jacket 101 is pressed against the metal roll 10
and a second position where the jacket 101 is moved away from the
metal roll 10. The calender is also equipped with a driving motor
(first driving motor) 12 which drives the metal roll 10. The motor
12 for driving the metal roll 10 will hereinafter be referred to as
a first driving motor. The motor 150 for driving the driving roll
130 will hereinafter be referred to as a second driving motor. The
first driving motor 12 functions as a master motor, while the
second driving motor 150 functions as a helper motor.
[0086] The roll-moving unit 160 is constructed, for example, of
fluid pressure cylinders such as hydraulic cylinders and air
cylinders, which are provided on the opposite ends of a center
shaft 104 which is the center shaft of the pressurizing roll 100
and on the opposite ends of a center shaft 137 which is the center
shaft of the driving roll 130. If the jacket 101 and the driving
roll 130 are moved toward and away from the metal roll 10 by the
fluid pressure cylinders (see vertical arrows in FIG. 2), the
jacket 101 can be moved between a first position where the jacket
101 is pressed against the metal roll 10 and a second position
where the jacket 101 is moved away from the metal roll 10.
Similarly, the doctor blade 120 can be moved in an up-and-down
direction by the roll-moving unit 160 (see vertical arrows in FIG.
3).
[0087] In response to an electrical signal from a controller
(control means) 170, the second driving motor 150 and roll-moving
unit 160 are controlled. The controller (control means) 170 also
controls the first driving motor 12 that drives the metal roll 10.
However, a description will be given of how the second driving
motor 150 and roll-moving unit 160 are controlled by the controller
170.
[0088] Initially, at the above-described second position, the
controller 170 controls the speed of the second driving motor 150.
That is, the rotational speed of the second driving motor 150 is
synchronized with the rotational speed of the first driving motor
12 serving as a master motor. More specifically, the peripheral
speed of the outer periphery of the jacket 101 is synchronized with
the peripheral speed of the outer periphery of the metal roll 10 by
the driving roll 130. At the second position, direct contact
between the high-temperature metal roll 10 and the jacket 101 is
avoided because the jacket 101 is held away from the metal roll
10.
[0089] Therefore, the problem of the heating of the jacket 101 by
the metal roll 10 is overcome. As a result, heat degradation of the
jacket 101 is prevented. Even if the heat-resisting temperature of
an elastic synthetic resin layer (e.g., a polyurethane resin layer)
mounted on the exterior layer of the jacket 101 is low, the
exterior layer will not reach the heat-resisting temperature. Thus,
the durability of the exterior layer of the jacket 101 can be
enhanced.
[0090] If the rotational speed of the second driving motor 150
(peripheral speed of the outer peripheral of the jacket 101)
synchronizes with the rotational speed of the first driving motor
12 (peripheral speed of the outer peripheral of the metal roll 10),
the roll-moving unit 160 is operated so that the jacket 101 is
pressed against the metal roll 10. When the rotational speed of the
jacket 101 is equal to that of the metal roll 10, there is no
difference in speed between the surface of the jacket 101 and the
paper sheet 15. Therefore, even if the paper sheet 15 is nipped by
the jacket 101 and the metal roll 10, the paper sheet 15 will not
be broken.
[0091] After the jacket 101 is pressed against the metal roll 10,
the second driving motor 150 is droop-controlled. In the drooping
control, if a load current through the second driving motor 150
increases, the speed of the second driving motor 150 is decreased.
That is, a load on the second driving motor 150 is stabilized by
controlling the speed of the second driving motor 150. Since the
drooping control stabilizes the allotment of a driving load between
the first driving motor 12 and the second driving motor 150, the
paper sheet 15 can be stably passed between the is metal roll 10
and the jacket 101.
[0092] If the load allotment between the first driving motor 12 and
the second driving motor 150 is stabilized, the paper sheet 15 is
pressurized by the pressurizing shoe 105. Thereafter, the drooping
control change to torque control. Torque control is performed to
change the load allotment (torque allotment) between the second
driving motor 150 and the first driving motor 12. The torque
control is the control of changing the load allotment between the
second driving motor 150 and the first driving motor 12. In the
first embodiment, the load allotment of the second driving motor
150 of the jacket 101 is reduced, while the load allotment of the
first driving motor 12 is increased by the amount of the reduced
load allotment of the second driving motor 150. Finally, the
driving torque of the second driving motor 150 is gradually reduced
to zero (typically for one to two minutes).
[0093] Thus, since the torque control is performed after
stabilization of the load allotment, the torque control is
prevented from being performed when the load allotment is unstable.
Therefore, a sudden change in the driving torque applied from the
jacket 101 and metal roll 10 to the paper sheet 15 is avoided, and
the breaking of the paper sheet 15 at this stage can be
prevented.
[0094] As described above, the reduced load is allotted to the
first driving motor 12. Therefore, during normal operation, the
jacket 101 is driven by the metal roll 10 instead of being driven
by the second driving motor 150. As a result, there is an advantage
that the load on the second driving motor 150 to drive the jacket
101 can be reduced. There is also an advantage that the control
load for rotating the second driving motor 150 in synchronization
with rotation of the metal roll 10 can be reduced.
[0095] A one-way clutch which does not transmit torque may be
provided between the second driving motor 150 and the driving roll
130. In this case, if the load on the jacket 101 is allotted to the
metal roll 10 after the jacket 101 is pressed against the metal
roll 10, and the speed of the second driving motor 150 is stopped
(or reduced), the jacket 101 will be driven by the metal roll 10
instead of being driven by the second driving motor 150. At this
time, there is no possibility that a torque load will be
transmitted from the second driving motor 150 to the metal roll 10.
Therefore, with a simple structure, the jacket 101 can follow the
metal roll 10 during normal operation.
[0096] That is, between the second driving motor 150 and the jacket
101, there may be provided a driving-force transmission line
changing mechanism, such as a one-way clutch, which changes a
driving-force transmission line so that the transmission of a
driving force from the second driving motor 150 to the driving roll
130 is cut off and that the jacket 101 is driven by the metal roll
10, if the rotational speed or driving force of the second driving
motor 150 is reduced when the jacket 101 is pressed against the
metal roll 10.
[0097] In this case, the driving roll 130 is rotated by rotation of
the jacket 101, and consequently, there is obtained an advantage
that the driving roll 130 functions as a support roll that prevents
vibration of the jacket 101.
[0098] Note that after the driving load of the second driving motor
150 for rotating the driving roll 130 is reduced to zero, the
driving roll 130 may be moved away from the jacket 101 by the
roll-moving unit 160. In such a case, the driving load of the first
driving motor 12 can be reduced.
[0099] In the first embodiment, the driving roll 130 and the doctor
blade 120, along with the pressurizing roll 100, are moved in the
up-and-down direction to nip the paper sheet 15 therebetween.
However, the driving roll 130 and the doctor blade 120 do not
always need to be moved in the same direction as the pressuring
roll 100. For example, they may be moved in a lateral
direction.
[0100] Now, a second embodiment of the present invention will be
described with reference to FIG. 4.
[0101] FIG. 4 shows the driving roll of a calender constructed in
accordance with the second embodiment of the present invention. In
the second embodiment, the driving roll 130 in the above-described
first embodiment is replaced with a divided type. Since the
remaining construction is the same as the first embodiment, a
description will be given of different parts. Note in FIG. 4 that
the same parts as FIG. 2 are represented by the same reference
numerals.
[0102] A driving roll 130 in the second embodiment is constructed
of a plurality of rolls 135 divided in the axial direction of a
pressurizing roll 100. The rolls 135 are rotated by a driving motor
150 through a connecting shaft 136. The weight of the rolls 135 of
the second embodiment is reduced, compared with the driving roll
130 of the first embodiment. As a result, power of the driving
motor 150 can be saved. In addition, since the jacket 101 is
supported at the interior and exterior surfaces thereof by the
support shoe 107 and the driving roll 130, vibration of the jacket
101 can be prevented.
[0103] Now, a third embodiment of the present invention will be
described with reference to FIG. 5.
[0104] FIG. 5 shows the doctor blade of a calender constructed in
accordance with the third embodiment of the present invention. In
the third embodiment, the doctor blade 120 in the above-described
first embodiment is replaced with a divided type. Since the
remaining construction is the same as the first embodiment, a
description will be given of different parts. Note in FIG. 5 that
the same parts as FIG. 3 are represented by the same reference
numerals.
[0105] A doctor blade 120 in the third embodiment is constructed of
two doctor blades divided in the axial direction of a pressurizing
roll 100. The two doctor blades 125 are disposed on a support plate
126 with a space. The doctor blades 125 are slid a predetermined
quantity in the axial direction of the pressurizing roll 100 by a
driving unit M so that paper dust, etc., are removed over the
entire surface of the jacket 101 of the pressurizing roll 100.
[0106] According to the third embodiment, the doctor blade 120 is
constructed of two divided doctor blades 125. Therefore, the
contact area between the doctor blades 125 and the jacket 101 is
reduced and wear on the jacket 101 is saved. The third embodiment
is provided with two doctor blades 125 slidable in the axial
direction of the pressurizing roll 100. However, the doctor blade
of the present invention may comprise one doctor blade slidable in
the axial direction, or it may comprise two or more doctor blades
slidable in the axial direction.
[0107] Now, a fourth embodiment of the present invention will be
described with reference to FIG. 6.
[0108] FIG. 6 shows the support shoes of a calender constructed in
accordance with the fourth embodiment of the present invention. In
the fourth embodiment, the support shoe 107 in the above-described
first embodiment is replaced with a divided type. Since the
remaining construction is the same as the first embodiment, a
description will be given of different parts. Note in FIG. 6 that
the same parts as FIG. 2 are represented by the same reference
numerals.
[0109] A support shoe 107 in the fourth embodiment is constructed
of 6 support shoes 107a divided in the axial direction of a
pressurizing roll 100. The support shoes 107a are disposed at
predetermined intervals on a pressurizing unit 107b. The support
shoes 107a support the jacket 101 along with a driving roll 130
disposed at the position opposite to the support shoes 107a through
a jacket 101. The jacket 101 is rotated by rotation of the driving
roll 130.
[0110] According to the fourth embodiment, the support shoe 107 is
constructed of 6 divided support shoes 107a. Therefore, the contact
area between the support shoes 107a and the jacket 101 is reduced
and wear on the jacket 101 is saved. As a result, the driving load
of the driving roll 130 is reduced and the power of the driving
motor 150 for driving the driving roll 130 is saved. While the
fourth embodiment is provided with 6 support shoes 107a, the
present invention is not limited to the 6 support shoes 107a.
[0111] Now, a fifth embodiment of the present invention will be
described with reference to FIG. 7.
[0112] FIG. 7 shows a calender constructed in accordance with the
fifth embodiment of the present invention. In the fifth embodiment,
the number of support shoes is increased to support a jacket 101 in
a state near to a circle. Since the remaining construction is the
same as the first embodiment, a description will be given of
different parts. Note in FIG. 7 that the same parts as FIG. 1 are
represented by the same reference numerals.
[0113] A rotatable metal roll 10 and a pressurizing roll 100 are
disposed at the opposite positions through a paper sheet 15. The
outer periphery of the pressurizing roll 100 is provided with a
resin jacket 101. Inside the jacket 101, there is provided a
statinary base 103.
[0114] A recessed, pressurizing shoe 105 and support shoes 106 to
109 are provided on the stationary base 103 for the purpose of
forming a pressuring nip (calender nip) for a calendering process.
The pressurizing shoe 105 and support shoes 106 to 109 are disposed
at 5 positions shifted 72 degrees from each other so that they are
equally balanced.
[0115] A driving roll 130 which is rotated by a driving motor 150,
a rotatable support roll 132 having no driving source, and doctor
blades 121 and 122 are disposed at the positions opposite to the
support shoes 106 to 109 through the jacket 101, respectively. With
this arrangement, the jacket 101 is reliably pressurized and held.
As a result, the vibration, runout, slippage, etc., of the jacket
101 can be prevented.
[0116] A lubricating-oil injection nozzle 140 is provided on the
upstream side of the pressurizing shoe 105 to perform lubrication
and cooling between the interior surface of the jacket 101 and the
pressurizing shoe 105. With lubricating oil 145 sprayed by the
lubricating-oil injection nozzle 140, lubrication is performed
between the jacket 101, which rotates while being pressurized and
held, and the shoes 105 to 109. As a result, the jacket is smoothly
rotated and generation of heat is prevented.
[0117] Thus, the fifth embodiment, as with the above-described
first embodiment, makes high-speed operation possible by preventing
the deformation, runout, and vibration of the jacket 101. In
addition, since the jacket 101 is pressurized and held at its
interior and exterior surfaces, smooth rotation of the jacket 101
is assured and slippage prevention is achieved. By removing dust on
the surface of the jacket 101 with the doctor blades 121 and 122,
quality is enhanced. At the same time, by reducing and preventing
the above-described vibration and runout, the life of the jacket
101 can be prolonged.
[0118] The driving roll 130 or support roll 132 in the fifth
embodiment may be an integral type, or a divided type described in
the second embodiment, or a combination type of them. Similarly,
the doctor blade 121 or 122 in the fifth embodiment may be an
integral type described in the first embodiment of FIG. 3, or a
divided type described in the third embodiment of FIG. 5, or a
combination type of them. Likewise, the support shoe 106, 107, 108,
or 109 in the fifth embodiment may be an integral type described in
the first embodiment of FIG. 1, or a divided type described in the
fourth embodiment of FIG. 6, or a combination type of them.
[0119] Although not shown in FIG. 7, in the fifth embodiment, as
with the above-described first embodiment, drooping control and
load allotment control may be performed on the first driving motor
12 and the second driving motor 150 by the roll-moving unit 160 and
controller 170. In this case, the same advantages as the first
embodiment can be obtained.
[0120] Now, a sixth embodiment of the present invention will be
described with reference to FIGS. 8A and 8B.
[0121] FIGS. 8A and 8B show the contact surfaces of the support
rolls of a calender constructed in accordance with the sixth
embodiment of the present invention. In the sixth embodiment, the
support shoe in the above-described fifth embodiment of FIG. 7 is
provided with grooves. Since the remaining construction is the same
as the fifth embodiment, a description will be given of different
parts.
[0122] A support shoe 180 shown in FIG. 8A is disposed inside the
jacket 101 of FIG. 7 at the position opposite to the driving roll
130 of FIG. 7. The outer periphery of the support shoe 180 is
provided with grooves 182, which extend in a direction where the
above-described jacket 101 rotates.
[0123] A support shoe 181 in FIG. 8B, as with the support shoe 180
of FIG. 8A, is disposed inside the jacket 101 of FIG. 7 at the
position opposite to the driving roll 130 of FIG. 7. The outer
periphery of the support shoe 181 is provided with grooves 183,
which extend obliquely with respect to the direction where the
above-described jacket 101 rotates.
[0124] According to the sixth embodiment, the lubricating oil 145
sprayed by the injection nozzle 140 of FIG. 7 flows through the
grooves 182 or 183 formed in the support roll 180 or 181 by
rotation of the jacket 101. That is, the lubricating oil 145 can
flow smoothly toward the downstream side. Therefore, since the
lubricating oil 145 does not stay in the bottom of the jacket 101,
smoother rotation of the jacket 101 becomes possible.
[0125] In the sixth embodiment, the support shoes 106, 108, and 109
of the fifth embodiment shown in FIG. 7 may also be provided with
the above-described grooves 182 or 183. In the case where all the
support shoes are provided with the grooves 182 or 183, the
lubricating oil 145 can flow along the entire interior surface of
the jacket 101 and therefore smoother rotation of the jacket 101
becomes possible. Furthermore, the support shoe 107a of the fourth
embodiment of FIG. 6 may be provided with the grooves 182 or
183.
[0126] Now, a seventh embodiment of the present invention will be
described with reference to FIGS. 9 and 10.
[0127] FIG. 9 shows a calender constructed in accordance with the
seventh embodiment of the present invention. FIG. 10 shows the
support roll of the calender. In the seventh embodiment, the number
of support shoes in the above-described first embodiment is
increased to hold a jacket 101. At the position opposite to a
driving roll 130, a support member is provided with a rotatable
roll. Since the remaining construction is the same as the first
embodiment, a description will be given of different parts. Note in
FIGS. 9 and 10 that the same parts as FIGS. 1 and 2 are represented
by the same reference numerals.
[0128] A rotatable metal roll 10 and a pressurizing roll 100 are
disposed at the opposite positions through a paper sheet 15. The
outer periphery of the pressurizing roll 100 is provided with a
resin jacket 101. Inside the jacket 101, there is provided a
stationary base 116.
[0129] A recessed, pressurizing shoe 105 and support shoes 106,
108, 109, and a support roll 110 are provided on the stationary
base 116. The support shoes 106, 108, 109, and a support roll 110
are disposed symmetrically With respect to the pressurizing shoe
105 at 4 positions shifted 90 degrees from each other so that they
are equally balanced.
[0130] A driving roll 130 which is rotated by a driving motor 150
is disposed at the position opposite to a support roll 110 through
the jacket 101. A doctor blade 120 is disposed at the position
opposite to the support shoe 106 109 through the jacket 101. With
this arrangement, the jacket 101 is reliably pressurized and held.
As a result, the vibration, runout, slippage, etc., of the jacket
101 can be prevented.
[0131] A lubricating-oil injection nozzle 140 is provided on the
upstream side of the pressurizing shoe 105 to perform lubrication
and cooling between the interior surface of the jacket 101 and the
pressurizing shoe 105, support members 106, 108, 109, 110. With
lubricating oil 145 sprayed by the lubricating-oil injection nozzle
140, lubrication is performed between the jacket 101, which rotates
while being pressurized and held, and the pressurizing shoe 105,
support members 106, 108, 109, 110. As a result, the jacket 101 is
smoothly rotated and generation of heat is prevented.
[0132] Thus, the seventh embodiment of FIG. 9, FIG. 10, as with the
above-described first embodiment, makes high-speed operation
possible by preventing the deformation, runout, and vibration of
the jacket 101. In addition, since the jacket 101 is pressurized
and held at its interior and exterior surfaces, smooth rotation of
the jacket 101 is assured and slippage prevention is achieved. The
life of the jacket 101 can be prolonged.
[0133] Further in the seventh embodiment, the support member
disposed opposite the driving roll 130 is the rotatable roll 110.
This roll 110 can reduce the friction resistance between itself and
the jacket 101 which develops when the jacket 101 is rotated by the
driving roll 130. Because the jacket 101 rotates smoothly, the
power of the driving motor 150 for driving the driving roll 130 can
be saved.
[0134] The seventh embodiment, as with the fifth embodiment of FIG.
7, may be provided with the rotatable support shoe 132 at the
position opposite to the support shoe 108 through the jacket 101.
The seventh embodiment may also be provided with the doctor blade
121 at the position opposite to the support shoe 106 through the
jacket 101.
[0135] As in the sixth embodiment of FIG. 8, the support shoes 106,
108, and 109 of the seventh embodiment may be provided with the
grooves 182 or 183.
[0136] The structure of the support shoes 106, 108, and 109 can be
made the same as the structure of the support roll 110.
[0137] Although not shown in FIG. 10, in the seventh embodiment, as
with the above-described first embodiment, drooping control and
load allotment control may be performed on the first driving motor
12 and the second driving motor 150 by the roll-moving unit 160 and
controller 170. In this case, the same advantages as the first
embodiment can be obtained.
[0138] Now, an eighth embodiment of the present invention will be
described with reference to FIGS. 11A and 11B.
[0139] FIGS. 11A and 11B show the support rolls of a calender
constructed in accordance with the eighth embodiment of the present
invention, respectively. In the eighth embodiment, the support roll
110 in the above-described seventh embodiment of FIG. 10 is
provided with grooves. Since the remaining construction is the same
as the seventh embodiment, a description will be given of different
parts.
[0140] A support roll 111 shown in FIG. 11A is disposed inside the
jacket 101 of FIG. 10 at the position opposite to the driving roll
130 of FIG. 10. The outer periphery of the support roll 111 is
provided with grooves 113, which extend in the peripheral
direction.
[0141] A support roll 112 in FIG. 11B, as with the support roll 111
of FIG. 11A, is disposed inside the jacket 101 of FIG. 7 at the
position opposite to the driving roll 130 of FIG. 7. The outer
periphery of the support roll 112 is provided with grooves 114,
which extend in spiral form.
[0142] According to the eighth embodiment, the lubricating oil 145
sprayed by the injection nozzle 140 of FIG. 7 flows through the
grooves 113 or 114 formed in the support roll 111 or 112 by
rotation of the jacket 101. That is, the lubricating oil 145 can
flow smoothly toward the downstream side. Therefore, since the
lubricating oil 145 does not stay in the bottom of the jacket 101,
smoother rotation of the jacket 101 becomes possible.
[0143] Now, a ninth embodiment of the present invention will be
described with reference to FIG. 12.
[0144] FIG. 12 shows the support roll of a calender constructed in
accordance with the ninth embodiment of the present invention. In
the ninth embodiment, the support roll 110 in the above-described
seventh embodiment is replaced with a divided type. Since the
remaining construction is the same as the seventh embodiment, a
description will be given of different parts. Note in FIG. 12 that
the same parts as FIG. 10 are represented by the same reference
numerals.
[0145] In the ninth embodiment, a support roll 110 is constructed
of rotatable rolls 115 divided in the axial direction of a
pressurizing roll 100.
[0146] According to the ninth embodiment, the support roll 110 is
constructed of divided rolls 115. Therefore, the area of the
support roll 110 that abuts the above-described jacket 101 is
reduced. Since the friction resistance that develops by rotation of
the jacket 101 is reduced, a load on the driving roll 130 is
reduced and therefore the power of the driving motor 150 for
rotating the driving roll 130 can be saved.
[0147] In FIG. 12, there are shown five support rolls. However, the
number of divided rolls is not limited to the 5 support rolls shown
in FIG. 12.
[0148] While the present invention has been described with
reference to the preferred embodiments thereof, the invention is
not to be limited to the details given herein, but may be modified
within the scope of the invention hereinafter claimed.
* * * * *