JP2017202919A - Dancer unit apparatus, treatment liquid application device, and image formation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dancer unit apparatus controlled at any of a plurality of conveyance speeds, capable of reducing a web loss amount (a waste paper amount) during conveyance at a low speed.SOLUTION: The dancer unit apparatus comprises a vertically-movable dancer unit 16 which is disposed between upstream conveyance means and downstream conveyance means being spaced apart on a web conveying path and conveying webs at a plurality of conveyance speeds including a normal speed, which absorbs the slack amount (web buffer amount) between the upstream conveyance means and the downstream conveyance means during the conveyance of a web, and which applies tension to the web by self-weight. The dancer unit apparatus changes the web buffer amount of the dancer unit 16 while the web is conveyed at the normal speed, in accordance with the plurality of conveyance speeds.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a dancer unit device, a processing liquid coating device, and an image forming system.

At least one printing device that forms an image on a continuous web, and a web processing device that performs a prescribed process on the web before or after printing, or a pre- and post-processing device that unwinds and winds a rolled web In many image forming systems, there are a plurality of web conveying means on the web conveying path in the system. In such a case, it is common to dispose a dancer unit in order to absorb the amount of web slack between the upstream web conveyance means and the downstream web conveyance means, and to apply appropriate tension to the web to be conveyed. It is. The dancer unit also has a buffer function that absorbs the difference in web conveyance speed between the upstream side and the downstream side with the dancer unit as a boundary. If the buffer amount is insufficient, when the upstream apparatus stops the web conveyance urgently due to some trouble, the web conveyance of the downstream apparatus cannot be stopped in time and the web tension increases rapidly. As a result, there is a possibility that the web breaks or an excessive load is applied to the parts constituting the dancer unit and the parts are broken.
Therefore, a dancer unit is already known in which the buffer amount is set so that the downstream apparatus can safely stop the web conveyance when the upstream apparatus stops the web conveyance in an emergency (for example, Patent Document 1).

  However, conventional dancer unit devices operate with the necessary buffer amount in the maximum speed mode among the plurality of transfer modes of the device or device system. Even a large amount of buffer is secured. For this reason, there has been a problem that an unnecessary amount of web loss (for example, waste paper) occurs when printing is started.

  The present invention relates to a dancer unit that is controlled at any one of a plurality of conveying speeds, and is capable of reducing a loss amount of a long object (for example, a web loss amount or a paper loss amount) during low-speed conveyance. The main purpose is to provide a device.

  In order to achieve the above-described object, the present invention provides upstream conveyance that conveys the long object at a plurality of conveyance speeds including a steady speed while being arranged on the conveyance path of the long object at intervals. Means for absorbing the slackness of the elongated object between the upstream conveying means and the downstream conveying means during conveyance of the elongated object; and A dancer unit apparatus comprising a dancer unit capable of raising and lowering to apply tension to the long object, wherein the long shape of the dancer unit is being transported at the steady speed. It is a dancer unit apparatus which changes the buffer amount of an object according to said some conveyance speed.

  According to the present invention, with the above configuration, in the dancer unit device controlled at any of a plurality of transport speeds, it is possible to reduce the amount of loss of long objects during low-speed transport.

1 is a schematic overall configuration diagram of an image forming system including a processing liquid coating apparatus according to Embodiment 1. FIG. 1 is an overall configuration diagram of a processing liquid coating apparatus according to Embodiment 1. FIG. (A) is a schematic front view of the dancer unit apparatus used for the process liquid coating apparatus which concerns on Embodiment 1, (b) is a schematic side view of the drive system of the dancer unit apparatus of (a). It is a figure for demonstrating the rotation direction of each member from the motor in the case of moving the dancer unit of FIG. 3 to a raising / lowering axis | shaft, (a) is a figure which shows the rotation direction of each member during web conveyance, (b) FIG. 6 is a diagram showing the rotation direction of each member when the dancer unit is raised when the web is loaded, and FIG. 8C is a diagram showing the rotation direction of each member when the dancer unit is lowered. It is a whole block diagram of the process liquid coating device which concerns on the modification 1. FIG. It is a whole block diagram of the process liquid coating device which concerns on the modification 2. FIG. It is a whole block diagram of the process liquid coating device which concerns on the modification 3. FIG.

  Hereinafter, embodiments of the present invention including examples will be described in detail with reference to the drawings. In each embodiment, components (members and components) having the same function, shape, and the like will be omitted by giving the same reference numerals after being described once unless there is a possibility of confusion. In order to simplify the drawings and the description, even if the components are to be represented in the drawings, the components that do not need to be specifically described in the drawings may be omitted as appropriate. In the case of quoting and explaining constituent elements such as published patent gazettes, the reference numerals are shown in parentheses to distinguish them from those of the embodiments and examples.

First, an image forming system 200 according to Embodiment 1 of the present invention will be described with reference to FIG. FIG. 1 is a schematic overall configuration diagram of an image forming system including a processing liquid coating apparatus according to the first embodiment.
An image forming system 200 shown in FIG. 1 is an example of forming an image by an inkjet method. An image forming system 200 illustrated in FIG. 1 sequentially includes a paper feeding device 100 as a preprocessing device, a processing liquid coating device 101, and an image forming device in order from the upstream side to the downstream side in the web conveyance direction X, which is the recording medium conveyance direction. An inkjet printer 102 as a printing apparatus is provided.
The image forming system 200 shown in FIG. 1 is basically the same as that shown in FIG. 7 of Japanese Patent Laid-Open No. 2013-224205 disclosed by the present applicant or FIG. 1 of Japanese Patent Laid-Open No. 2015-120268. The same is true. In this specification, the processing agent liquid is referred to as “processing liquid”, and the processing agent liquid coating apparatus is referred to as “processing liquid coating apparatus”.
As shown in FIG. 1, a sheet roll (for example, a sheet roll (for example, a continuous paper or a continuous paper as a long recording medium) wound around a core tube is formed in the paper feeding device 100. Roll paper or the like) is detachably provided. The sheet feeding device 100 is configured so that the web W can be fed out from the sheet roll. The long recording medium is an example of a long object.

The web W fed out from the paper feeding device 100 is sent to the processing liquid coating device 101 and ink droplets are applied to the web W in order to solve problems such as bleeding, density, color tone and show-through on the image forming surface of the web W. Before landing, a treatment liquid having a function of aggregating ink is applied. The surface on which the treatment liquid is applied may be only one side or both sides depending on the desired printed matter.
The processing liquid coating apparatus 101 shown in FIG. 1 includes a processing liquid coating unit 13r that coats the processing liquid on the back surface of the web W, a processing liquid coating unit 13f that coats the surface of the web W, and a coating liquid after the processing liquid coating. And drying means 12r and 12f for drying the web W. Further, the treatment liquid coating apparatus 101 includes a feed roller, a dancer unit 16 and the like which will be described in detail later.

In addition to the plurality of recording heads 105 that eject ink and form an image, the inkjet printer 102 includes a mechanism that detects and suppresses the meandering of the web W, and detects and suppresses the tension applied to the web W. The mechanism to do is installed. The above-described mechanism other than the recording head 105 is not shown because it is not closely related to the present invention.
The plurality of recording heads 105 as liquid ejection heads eject and eject ink jet ink from the nozzles onto the web W, for example, yellow (Y), cyan (C), magenta (M), and black (K). A full color image can be formed by discharging liquids of the respective colors. The plurality of recording heads 105 are arranged in a sub-scanning direction orthogonal to the main scanning direction with a nozzle row composed of a plurality of nozzles mounted with the ejection direction facing downward, or a so-called line type configuration example. Good. Examples of the energy generation source for ejecting ink droplets as liquid include a piezoelectric actuator, a thermal actuator using an electrothermal conversion element such as a heating resistor, and an electrostatic actuator composed of a diaphragm and a counter electrode.
Specific examples of the web W include sheets, for example, special paper such as paper, recording paper, recording paper, film, and coated paper. It includes all transported materials that can be transported in the same manner as paper in the form of sheets such as paper, recording media, OHP, prepreg, and copper foil.

When performing duplex printing, a turn unit that reverses the web W downstream of the ink jet printer 102, a second ink jet printer that prints the back surface, and a winding device or a cutter device that cuts and stacks the web downstream. Connect the aftertreatment device.
In the post-processing apparatus, a predetermined post-processing (cutting into a predetermined size, punching processing, binding processing, or collating processing is performed on a web that has been appropriately printed on the front and back surfaces of the web. Etc.) are included.

  The paper feeding device 100 and the processing liquid coating apparatus 101, the processing liquid coating apparatus 101 and the ink jet printer 102, and the ink jet printer 102 and the post processing apparatus are connected by an I / F cable (not shown). The entire image forming system 200 is controlled and managed by a print control apparatus appropriately disposed in the inkjet printer 102 or the like.

The operation of the image forming system will be described. The web W fed out from the paper feeding device 100 is fed into the processing liquid coating device 101. In the treatment liquid coating apparatus 101, the web W is dried by the drying means 12r and 12f after the treatment liquid is applied by the treatment liquid application means 13r and 13f. Further, the dried web W passes through the feed roller and dancer unit 16 and is fed into the inkjet printer 102.
In the ink jet printer 102, a plurality of recording heads 105 eject ink onto the web W coated with the processing agent liquid, thereby printing a full image or an image of one color or a plurality of colors.

  As described above, in the image forming system 200 according to the first embodiment, the processing liquid coating apparatus 101 is disposed on the upstream side of the inkjet printer 102 along the web conveyance direction X, and the processing liquid is applied to the web W to be printed in advance. doing. Accordingly, it is possible to suppress ink bleeding during printing and form an image with high image quality.

The overall configuration of the treatment liquid coating apparatus according to the first embodiment will be described with reference to FIG. FIG. 2 is an overall configuration diagram of the processing liquid coating apparatus according to the first embodiment, and shows a state when the processing liquid is applied.
As shown in FIG. 2, the processing liquid coating apparatus 101 has a bearing at the end of the roller, and a large number of rotatable guide rollers 1 are installed inside the processing liquid coating apparatus 101 to convey the web W. A transport path is secured.
As shown in FIG. 1, the web W drawn from the sheet feeding device connected upstream and passed through the treatment liquid coating means 13 r and 13 f on the front and back surfaces is applied to the front and back surface drying means. Pass 12r, 12f.

The web W that has passed through the drying means 12r and 12f is conveyed by a feed roller 10 and a feed nip roller 9 connected to a driving source such as a motor and sent to the dancer unit 16, and then the ink jet arranged downstream of FIG. Supplied to the printer.
The dancer unit 16 has a buffer function that absorbs the difference in the web transport speed between the upstream side and the downstream side (hereinafter also simply referred to as the transport speed) from the dancer unit 16 itself, and the weight of the dancer unit 16 itself. And a function of imparting tension.

The configuration and drive system of the dancer unit apparatus used in the treatment liquid coating apparatus of Embodiment 1 will be described with reference to FIGS. FIG. 3A is a schematic front view of a dancer unit device used in the treatment liquid coating apparatus according to the first embodiment, and FIG. 3B is a schematic side view of a drive system of the dancer unit in FIG. FIG.
As will be described later, the dancer unit includes at least a dancer roller. The details of the dancer unit apparatus of FIGS. 3 and 4 are substantially the same as the dancer roller mechanism (17) disclosed in FIGS. 1 and 2 of the above-mentioned Japanese Patent Application Laid-Open No. 2013-224205.
The dancer unit apparatus includes a dancer unit configured to include at least a dancer roller, various sensors appropriately provided for controlling the operation of the dancer unit, a dancer control circuit, and a motor related to the drive of the dancer unit. And the like drive means. Therefore, the treatment liquid coating apparatus 101 according to the first embodiment includes a dancer unit apparatus or a dancer roller apparatus.

  As shown in FIGS. 3A and 3B, the dancer unit 16 includes dancer rollers 15a and 15b, a movable frame 18, a shaft guide 19 and the like. Two rail shafts 20 are arranged at predetermined intervals along the vertical / vertical direction Z that is the direction of gravity, and a dancer unit 16 indicated by a one-dot chain line is arranged between the two rail shafts 20. Has been. As shown in FIG. 3A, a plurality of (three in the first embodiment) shaft guides 19 are fixed to the side surface of the movable frame 18, and the rail shaft 20 is attached to the plurality of shaft guides 19. The movable frame 18 is sandwiched and movable in the vertical direction Z.

  The movable frame 18 is connected to the timing belt 23 by a belt clamper 21. The timing belt 23 is stretched between a pair of upper and lower timing pulleys 22a and 22b. The timing pulleys 22a and 22b are phase-locked with keys or the like at both ends of the elevating shafts 24a and 24b that are rotatably supported on the main body frame (meaning that they move circularly in the forward and reverse directions).

  A drive transmission gear 35a is attached to one end of the elevating shaft 24a. The drive transmission gear 35a fixes the one-way clutch 35 inside by press-fitting. The drive transmission gear 35a meshes with the drive gear 28 attached to the drive shaft of the motor 30 that can be rotated forward and backward. The motor 30 is attached and fixed to the main body frame.

  FIG. 4 is a diagram for explaining the rotation direction of each member from the motor 30 to the lifting shaft 24a when the dancer unit 16 is moved. FIG. 4A is a diagram illustrating the rotation direction of each member during web conveyance, and FIG. 4B is a diagram illustrating the rotation direction of each member when the dancer unit 16 is raised when the web W is loaded. FIG. 4C is a diagram illustrating the rotation direction of each member when the dancer unit 16 is lowered.

  The direction in which the one-way clutch 35 is allowed to rotate is a direction in which the web W is loosened by the operation of the dancer unit 16 (the direction in which the dancer unit 16 is raised) when the drive transmission gear 35a is not rotating. That is, when the drive transmission gear 35a does not rotate, the dancer unit 16 can move in the web loosening direction (direction in which the dancer unit 16 rises), but cannot move in the web pulling direction (direction in which the dancer unit 16 descends). It is like that.

  At the time of loading the web W, it is necessary to improve the operability of loading the web by raising the dancer unit 16 and shortening the continuous path length with the guide roller 1 as shown by the solid line in FIG. .

  At this time, in order to raise the dancer unit 16, as shown in FIG. 4B, when the motor 30 (drive gear 28) is rotated in the clockwise direction B, the drive transmission gear 35a meshing with the drive gear 28 is obtained. Rotates counterclockwise in the C direction. An arrow D direction indicates a locking direction of the one-way clutch 35, and is a direction in which the housing (outer race) is locked when the shaft is fixed, and a direction in which shaft rotation is allowed when the housing is fixed.

  As described above, when the drive transmission gear 35a rotates counterclockwise in the C direction, the one-way clutch 35 is in a locked state, so that the rotational driving force is transmitted to the lift shaft 24a via the one-way clutch 35, and the lift shaft 24a is Rotate in E direction.

  When the elevating shaft 24a rotates in the direction of arrow E, the dancer unit 16 rises via the timing pulleys 22a and 22b and the timing belt 23, the web is slackened, and the path length of the web W can be shortened.

  FIG. 4C shows a case where the dancer unit 16 is lowered. When the motor 30 (drive gear 28) is rotationally driven in the counterclockwise F direction opposite to FIG. 4B, the drive gear 28 and The meshed drive transmission gear 35a rotates in the clockwise direction G, and the one-way clutch 35 also rotates in the same clockwise direction G.

  Since the clockwise direction G is not the lock D direction of the one-way clutch 35 described above, the elevating shaft 24a does not rotate forcibly. At this time, the lifting shaft 24 is also rotated by the weight / self-weight of the dancer unit 16. As a result, the lifting shaft 24 also rotates in the direction of the arrow H as the drive transmission gear 35a rotates. Descend.

  Thus, in order to switch the web path length, such as when the web is loaded, the dancer unit 16 can be moved up or down.

Next, the function of the dancer unit 16 during web conveyance will be described with reference to FIG.
As described above, the dancer unit 16 is suspended by the web W (see FIG. 2) during web conveyance. In order for the dancer unit 16 to perform the buffer function, it must be configured as follows. That is, the web length varies depending on the web conveyance speed difference between the upstream feed roller 10 (FIG. 2) and the conveyance means that determines the web feeding speed in the downstream inkjet printer 102 (FIG. 1). The dancer unit 16 must move up and down in response to changes.

Here, when the web length is short, that is, when the dancer unit 16 needs to be lifted, the one-way clutch 35 is not in the locking direction, and the dancer unit 16 can be lifted by being suspended from the web W. is there.
Conversely, when the web length becomes longer, that is, when the dancer unit 16 needs to descend, the one-way clutch 35 is in the locking direction. For this reason, in this state, the dancer unit 16 does not descend, and as a result, the web W is slackened and tension cannot be applied to the web, which is another function of the dancer unit 16.

  Therefore, in the first embodiment, the one-way clutch 35 is rotated in the direction in which the dancer unit 16 moves in the web pulling direction. 4A, the motor 30 (drive gear 28) is rotationally driven in the same counterclockwise F direction (originally the direction in which the dancer unit 16 descends) as in FIG. 4C, and meshes with the drive gear 28. The drive transmission gear 35a and the one-way clutch 35 are rotated clockwise in the G direction.

  By doing so, due to the difference in rotational speed between the lifting / lowering shaft 24 and the one-way clutch 35, when the one-way clutch 35 is used as a reference, the lifting / lowering shaft 24 rotates relatively in a direction other than the locking direction. be able to. Therefore, the dancer unit 16 can descend following the change in the web length, and can continue to apply tension to the web W.

  When the web breaks during web conveyance, the timing pulleys 22a and 22b and the timing belt are driven in accordance with the rotational speeds of the original drive transmission gear 35a, the one-way clutch 35, and the lifting shaft 24 that are rotationally driven by the motor 30. 23 will operate. As a result, the dancer unit 16 descends at a specified speed. Therefore, the impact of the collision due to the free fall of the dancer unit 16 as in the prior art does not occur, and the dancer unit 16 can be prevented from being damaged. In addition, the configuration is simpler than the conventional dancer roller mechanism and dancer unit, and the reliability is high and the cost is low.

  3 and 4, the configuration in which the one-way clutch 35 is provided in the drive transmission gear 35 a has been described as an example. However, the same effect can be obtained if the one-way clutch 35 is in the drive transmission system of the motor 30 and the dancer unit 16. Of course it is possible. For example, you may arrange | position between the drive gear 28 and the drive shaft of the motor 30, or between the timing pulley 22a and the raising / lowering shaft 24.

  3 and 4, the drive transmission from the motor 30 to the lifting shaft 24 is performed by a gear. However, a drive transmission system using a timing pulley and a timing belt may be used, and a one-way clutch may be arranged on the timing pulley. Good.

Although the description is mixed, the control of the dancer unit 16 will be described with reference to FIG. As described above, the transport speed on the upstream side of the dancer unit 16 is determined by the rotational speed of the feed roller 10, and the transport speed on the downstream side of the dancer unit 16 is provided on the downstream device (such as the ink jet printer of FIG. 1). Determined by the rotation speed of the feed roller).
Further, the buffer function secures a buffer amount sufficient to safely stop the web conveyance on the downstream side of the dancer unit 16 when the web conveyance on the upstream side of the dancer unit 16 is stopped due to some trouble.

That is, if the buffer amount is insufficient, when the upstream device stops the web transport urgently due to some trouble, the web transport of the downstream device cannot be stopped in time and the web tension increases rapidly. End up. As a result, there is a possibility that the web breaks or an excessive load is applied to the parts constituting the dancer unit and the parts are broken. Here, examples of components that may be damaged include a timing belt and a belt clamper provided in the dancer unit 16.
For example, when the downstream apparatus is stopped, when decelerating at 1 m / sec ² , 3.125 m is required to stop in the speed mode of 150 m / min (2.5 m / sec).
3.125 m = 2.5 (m / sec) × [2.5 (m / sec) ÷ 1 (m / sec ² )] / 2
Actually, the dancer unit 16 is moved up and down by the web transport amount and dancer unit control until it is detected that the web transport upstream of the dancer unit 16 has stopped urgently, and a margin is added. Length is necessary. If this length is 0.475 m, the required buffer amount is 3.6 m.

In the apparatus of FIG. 2, the lift control position (height) of the dancer unit 16 at the steady state speed from the acceleration state at the time of activation is detected by a dancer control sensor 17 as unit position determination means / unit position detection means. Yes. The dancer control sensor 17 is a reflective photosensor.
When the dancer control sensor 17 is shielded from light, that is, when the dancer unit 16 is detected by the dancer control sensor 17, the rotational speed of the feed roller 10 is decreased because the dancer unit 16 is below a specified position. .
On the contrary, when the dancer control sensor 17 is transmitted, that is, when the dancer unit 16 is not detected by the dancer control sensor 17, the rotational speed of the feed roller 10 is high because the dancer unit 16 is above a predetermined position. To speed up. By having a dancer control circuit that performs such control, the dancer unit 16 maintains a substantially constant height.

In the processing liquid coating apparatus 101 of FIG. 2, since the dancer unit 16 is hung with four webs W, the unit upper limit position where the dancer unit 16 rises to the upper limit and the web length becomes the shortest when the web is loaded. On the other hand, the dancer unit 16 is 0.9m = 3.6m ÷ 4
The control sensor 17 is mounted at the position 17a that is lowered only (when the conveyance speed is 150 m / min, which is the maximum speed / high speed mode).

In the processing liquid coating apparatus 101 of FIG. 2, before printing with the inkjet printer 102, a processing liquid that suppresses ink bleeding or the like is applied to the printing surface of the web W in order to improve print quality. Therefore, printing is not performed until the portion to which the treatment liquid is applied reaches the position of the recording head 105 of the inkjet printer 102 on the downstream side, and the portion becomes a waste paper as a web loss amount. The web buffer amount of the dancer unit 16 is also included in the length of the waste paper.
Here, in the speed mode of 30 m / min (0.5 m / sec), the buffer amount required until the downstream device (inkjet printer) that decelerates at 1 m / sec ² stops is 0.125 m. That is,
0.125 m = 0.5 (m / sec) × [0.5 (m / sec) ÷ 1 (m / sec ² )] / 2
Even if 0.475 m for the emergency stop detection, the control range, and the margin are added, the necessary buffer amount is 0.6 m.

That is, in order to support the maximum speed mode of 150 m / min, it is necessary to have a configuration in which 3.6 m is ensured as the web buffer amount, but with the same web buffer amount, 3 m (= 3.6 m) in the low speed mode of 30 m / min. -0.6 m) of extra waste paper is generated.
In order to solve this, in Embodiment 1 of the present invention, the position of the dancer control sensor 17 is made variable and is switched for each speed mode. For example, in the high speed mode 150 m / min, the dancer control sensor 17 is mounted and arranged at a position 17a that is 0.9 m lower than the unit upper limit position.
In the low speed mode of 30 / min, the dancer control sensor 17 is moved and mounted and arranged at a position 17b that is 0.15 m (= 0.6 m ÷ 4) below the unit upper limit position. By doing so, the position maintained approximately constant by the elevation control of the dancer unit 16 changes, and the web buffer amount can be reduced. That is, it is possible to reduce the amount of paper lost at the start of printing in the low speed mode 30 / min by 3 m.

  In FIG. 2, in order to make the position of the dancer control sensor 17 variable, for example, a sensor position mounting member having screw holes capable of fastening the dancer control sensor 17 with screws or the like at a plurality of positions in the vertical direction Z is provided. That's fine. With such a simple configuration, the position of the dancer control sensor 17 can be easily changed. Alternatively, there is a method in which a member movable in the vertical direction Z is installed and the dancer control sensor 17 is attached thereto.

In the case of the processing liquid coating apparatus 101 of FIG. 2, it is only necessary to change the mounting position of the dancer control sensor 17, and the dancer unit control that adjusts the rotational speed of the feed roller 10 by the light shielding / transmission of the sensor is basically Need not be changed. Further, when the web is loaded, it is necessary to move the dancer unit 16 to the unit upper limit position. However, since the distance from the dancer control position is shortened, the time for raising the dancer unit 16 to the unit upper limit position when loading the web. Further, it is possible to shorten the time for the dancer unit 16 to be lowered to the control position for printing preparation, and it is possible to suppress the machine downtime.
Furthermore, since the lift distance of the dancer unit 16 is shortened, wear of the drive system gear for driving the dancer unit 16 to be lifted can be suppressed and the life of the parts can be extended, so that the machine downtime required for parts replacement can also be suppressed.

When printing is started for double-sided printing, the path length from the processing liquid application unit 13r that applies the processing liquid to the back surface of the web W to the recording head 105 that prints on the front surface becomes waste paper. Actually, printing is started by the recording head 105 with the length of the path length plus a margin as waste paper. For example, when the buffer amount 3.6 m of the dancer unit 16 necessary for the high speed mode 150 m / min is included, the length of the waste paper is about 15 m.
According to the first embodiment of the present invention, the amount of paper loss in the low speed mode 30 m / min can be reduced by 20% (3 m), so the effect is great.

For example, if the required buffer amount at 75 m / min is calculated in the same manner, it is about 1.26 m.
1.26 m≈1.25 (m / sec) × [1.25 (m / sec) ÷ 1 (m / sec ² )] ÷ 2 + 0.475 m
In the processing liquid coating apparatus 101 of FIG. 2, the dancer control sensor 17 is mounted at a position lowered by 0.315 m (= 1.26 m ÷ 4) from the unit upper limit position, so that when the 75 m / min mode printing is started. The amount of damaged paper can be reduced by 2.3 m or more.
Speed mode, deceleration at emergency stop, dancer unit control range, etc. are examples, but even if each specification is different, the necessary buffer amount is calculated by the same calculation and the mounting position of dancer control sensor 17 is determined. By doing so, it is possible to reduce the amount of waste paper.

  As described above, according to the first embodiment, it is not necessary to change the control of the dancer unit, and the conventional control can be used as it is. Therefore, the number of control development steps can be reduced, and the number of sensors such as dancer control sensors does not increase, so that an inexpensive device can be provided.

(Modification 1)
The elevation position control of the dancer unit of the treatment liquid coating apparatus 101A according to the first modification of the first embodiment will be described with reference to FIG. FIG. 5 is an overall configuration diagram of the processing liquid coating apparatus according to the first modification.
The processing liquid coating apparatus 101A of the first modification uses a high-speed mode dancer control sensor 31 and a low-speed mode dancer control sensor 32 in place of the dancer control sensor 17 as compared with the processing liquid coating apparatus 101 of FIG. Only the point is different.

A high speed mode dancer control sensor 31 and a low speed mode dancer control sensor 32 are provided as a plurality of unit position determining means at positions where the buffer amount of the dancer unit 16 corresponding to the plurality of speed modes can be secured. The high-speed mode dancer control sensor 31 and the low-speed mode dancer control sensor 32 are reflective photosensors.
Even in the first modification, it is not necessary to change the dancer unit control itself, and it is possible to use the dancer control sensor according to the speed mode by selecting and using the dancer control sensor, and the same effect can be obtained.

  According to the modified example 1, by configuring as described above, the switching time for changing the mounting position of the dancer control sensor can be reduced, and the machine downtime can be reduced. In other words, even when a print job is executed so as to frequently switch the speed mode, the switching man-hours (downtime) can be suppressed.

When there are three or more speed modes, the maximum effect according to the speed mode can be obtained by installing a dancer control sensor for each speed mode.
However, if the number of dancer control sensors is reduced and the high-speed mode dancer control sensor 31 is used in the intermediate speed mode, a buffer amount necessary for an emergency stop can be secured. Accordingly, the function is not impaired, and when the low-speed mode is used, the use of the low-speed mode dancer control sensor 32 can reduce paper loss at the time of starting printing. Various sensor numbers and sensor mounting positions are conceivable, but it goes without saying that the effect of the first modification can be obtained.

(Modification 2)
The raising / lowering position control of the dancer unit of the process liquid coating apparatus 101B which concerns on the modification 2 of Embodiment 1 is demonstrated using FIG. FIG. 6 is an overall configuration diagram of a processing liquid coating apparatus according to Modification 2.
The treatment liquid coating apparatus 101B of Modification 2 is different from the treatment liquid coating apparatus 101 of FIG. 2 and the like in place of the dancer control sensor 17 and a dancer unit position detection sensor 41 and a large number of slits that are detection targets. The difference is that the slit member 42 is formed.

The dancer unit position detection sensor 41 is a reflection type photosensor that is mounted on the dancer unit 16 and moves together with the dancer unit 16. The slit member 42 is fixed to the main body frame.
The dancer unit position detection sensor 41 and the slit member 42 function as unit position detection means for detecting the absolute position of the dancer unit 16 in a relatively wide range within the movable range of the dancer unit 16.

  For example, the lift position of the dancer unit 16 can be recognized and controlled by adding / subtracting the number of slits of the slit member 42 detected by the dancer unit position detection sensor 41 with the above-described dancer control circuit with the unit upper limit position as the home position. There are various ways of recognizing the home position, such as a method of individually providing a home position sensor or a method of mechanically moving the position to the end as a home position.

In the second modification, by configuring as described above, it is not necessary to increase the number of sensors even when the number of speed modes is large, and a dancer control position (number of slits from the home position) suitable for each speed mode is set. Set in the dancer control circuit.
Thereby, according to the modification 2, the paper loss at the time of starting printing in each speed mode can be reduced. Further, an apparatus (system) having a large number of speed modes can be dealt with only by changing the control set value, and it is not necessary to increase the number of sensors, so that an inexpensive apparatus can be provided. Furthermore, even when a print job is executed so that the speed mode is frequently switched, the switching man-hours (downtime) can be suppressed.

(Modification 3)
The raising / lowering position control of the dancer unit of the processing liquid coating apparatus 101C according to the third modification of the second modification will be described with reference to FIG. FIG. 7 is an overall configuration diagram of a treatment liquid coating apparatus according to Modification 3.
The processing liquid coating apparatus 101C of Modification 3 detects the encoder slit member 52 mounted on the guide roller 1, which is an idler roller downstream of the dancer unit 16, as compared with the processing liquid coating apparatus 101B of FIG. The difference is that the rotation detection sensor 51 is newly used.

  The conveyance speed of the web W can be calculated using the diameter and rotation speed of the guide roller 1. What is calculated here is the web conveyance speed of the inkjet printer 102 of FIG. Accordingly, the web buffer amount of the dancer unit 16 can be varied following the acceleration / deceleration of the web W in almost real time, and the amount of paper loss at the start of printing can be minimized regardless of the speed mode at the steady speed. .

In other words, the necessary buffer amount when the web W is stopped (web speed 0 m / min) is only the emergency stop detection amount, the control range portion, and the margin portion, and this is assumed to be 0.475 m. Let the position of the dancer unit 16 be the A position. Regardless of the speed mode, the dancer unit 16 before starting printing and after stopping printing is controlled to come to the A position. The necessary buffer amount is calculated by the above-described dancer control circuit from the web conveyance speed (hereinafter simply referred to as the conveyance speed) calculated from the detection value of the rotation detection sensor 51.
When the conveyance speed is accelerated, the position of the dancer unit 16 is lowered so that the necessary web buffer amount at that time can be secured. Conversely, when the conveyance speed is decelerated, the position of the dancer unit 16 is decreased. The rotational speed of the feed roller 10 is controlled so as to increase the speed.
Also, even when printing with a combination of jobs in a plurality of speed modes, the dancer unit 16 is always in the A position when printing is stopped. There is also an effect that the time for lowering the unit 16 to the A position can be minimized.

  In the third modification, the configuration as described above has an effect that in a device or device system having a large number of speed modes, the minimum amount of paper loss can be accommodated when used in any speed mode. .

  In the third modification, the example in which the processing liquid coating apparatus 101C has the encoder slit member 52 and the rotation detection sensor 51 for detecting the web conveying speed in order to detect the web conveyance speed of the downstream ink jet printer 102 has been described. It is not limited. That is, when information on the web conveyance speed is provided in real time from the inkjet printer 102, the speed information may be used, and the encoder slit member 52 and the rotation detection sensor 51 for detecting it are unnecessary.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to such specific embodiments and examples, and is described in the claims unless otherwise limited by the above description. Various modifications and changes can be made within the scope of the present invention. For example, the above embodiment and Example 1 may be appropriately combined.

  The effects described in the embodiments and examples of the present invention only list the most preferable effects resulting from the present invention, and the effects of the present invention are limited to those described in the embodiments of the present invention. Is not to be done.

DESCRIPTION OF SYMBOLS 1 Guide roller 9 Feed nip roller 10 Feed roller 12r, 12f Drying means 13r, 13f Treatment liquid application means 15a, 15b Dancer roller (component of dancer unit)
16 Dancer unit 17 Dancer control sensor (an example of unit position determination means)
17a Mounting position of dancer control sensor in high speed mode 17b Mounting position of dancer control sensor in low speed mode 30 Motor (drive means)
31 Dancer control sensor for high-speed mode (an example of unit position determination means)
32 Dancer control sensor for low-speed mode (an example of unit position determination means)
41 Dancer unit position detection sensor (an example of unit position determination means)
42 Slit Member 51 Rotation Detection Sensor 52 Encoder Slit Member 100 Paper Feed Device 101, 101A, 101B, 101C Treatment Liquid Coating Device 102 Inkjet Printer 200 Image Forming System W Web (Elongated Material, Example of Long Recording Medium) )
X Web transport direction (an example of the recording medium transport direction)
Z Vertical direction

Japanese Patent Laid-Open No. 62-205954

Claims (7)

It is arranged between the upstream side transport means and the downstream side transport means that are arranged at intervals on the transport path of the long object and transport the long object at a plurality of transport speeds including a steady speed. During the transport of the long object, the slack of the slender object between the upstream transport means and the downstream transport means is absorbed and tension is applied to the long object. A dancer unit device with possible dancer units,
The dancer unit apparatus which changes the buffer amount of the said elongate thing of the said dancer unit when the said elongate thing is conveyed at the said steady speed according to the said some conveyance speed. The dancer unit device according to claim 1,
Unit position determining means for determining a lift control position of the dancer unit;
The dancer unit apparatus characterized by changing the mounting position of the unit position determining means for each transport speed. The dancer unit device according to claim 1,
Having at least a plurality of unit position determining means for determining the lift control position of the dancer unit;
A dancer unit apparatus characterized in that the unit position determining means is switched and used in accordance with the transport speeds. The dancer unit device according to claim 1,
Unit position detecting means for detecting the absolute position of the dancer unit in a relatively wide range within the movable range of the dancer unit;
A dancer unit apparatus, wherein the dancer unit is used by changing the control set value of the lift control position of the dancer unit based on a signal from the unit position detecting means in accordance with each transport speed. The dancer unit device according to claim 4,
A dancer unit apparatus characterized in that the slack amount of the long object of the dancer unit is controlled in real time using the transport speed information of the downstream transport means. The long object is a long recording medium,
Treatment liquid application means for applying a treatment liquid to at least one surface of the recording medium;
Upstream transport means for transporting the recording medium coated with the treatment liquid at the plurality of transport speeds;
Downstream transport means for transporting the recording medium coated with the treatment liquid at the plurality of transport speeds;
The dancer unit apparatus according to any one of claims 1 to 5, provided between the upstream transport unit and the downstream transport unit,
A treatment liquid coating apparatus comprising: A processing liquid coating device for applying a processing liquid to the recording medium before image formation is installed on the upstream side in the transport direction along the transport direction of the recording medium. In an image forming system in which a printing apparatus including an ink jet recording apparatus for forming an image by ejecting ink droplets onto a recording medium coated with a treatment liquid is installed on the downstream side.
The image forming system according to claim 6, wherein the processing liquid coating apparatus is the processing liquid coating apparatus according to claim 6.

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