JP7304001B2 - Drying equipment and printing equipment - Google Patents

Description

The present invention relates to a drying device and a printing device.

2. Description of the Related Art Conventionally, a drying device for drying an object to which liquid has been applied is known. For example, Patent Literature 1 describes a drying apparatus provided with recovery means for recovering a liquid liquefied by condensation inside the drying apparatus, and a drain pipe for draining the liquid from the recovery means.

In this type of drying apparatus, it is necessary to improve the recovery efficiency of the liquid condensed and liquefied as the drying efficiency for the object to be dried is increased.

In order to solve the above-described problems, the present invention provides a drying apparatus for drying an object to which a liquid has been applied, comprising recovery means for recovering liquid condensed and liquefied inside the drying apparatus; A drain pipe for draining the liquid from the recovery means, a pump for sending the liquid through the drain pipe, and a mechanism involving sliding switching between connection and disconnection between the recovery means and the pump. It is characterized in that whether or not to perform the liquid waste operation accompanying the actuation of the connecting/disconnecting means is determined based on the liquid presence/absence information at the sliding portion.

According to the present invention, it is possible to improve the recovery efficiency of the liquid condensed and liquefied as compared with the conventional device.

1 is a front view showing a schematic configuration of an inkjet printer; FIG. FIG. 2 is a partially enlarged view of FIG. 1; FIG. 2 is an enlarged perspective view of parts of the printer; FIG. 2 is a configuration diagram of a waste liquid recovery unit of the same printer; FIG. 4 is an explanatory diagram of a rotary valve of the same printer; 4 is a flowchart of control of the same printer; FIG. 4 is a configuration diagram of a modified example of the waste liquid recovery unit of the same printer. 4 is a flow chart of another control of the same printer; Explanatory drawing of the modification of a waste-liquid collection|recovery part. The flowchart of the control of the same modification. FIG. 10 is a flow chart of another control of the same modified example; FIG.

An embodiment in which the present invention is applied to a drying device of a printing device will be described. FIG. 1 is a front view showing a schematic configuration of a printing system 100, which is a printing apparatus. The printing system 100 is configured by combining a sheet feeding device 10 , an inkjet printer 20 as a liquid applying section, a drying device 30 and a sheet winding device 40 .

The sheet feeding device 10 is a device for feeding a sheet material 11, which is a continuous recording medium. The sheet material 11 becomes an object to be dried to which a liquid is applied and which is conveyed. The sheet feeding device 10 includes a main winding roller 12 that holds the sheet material 11 and a conveying roller 13 .

The inkjet printer 20 is a device that transports the sheet material 11 to an image forming unit 21 that forms an image by ejecting liquid ink onto the sheet material 11 and transports the sheet material 11 to the drying device 30 . The inkjet printer 20 has an image forming section 21 including a liquid ejection head that ejects ink, which is a liquid of a desired color, onto the sheet material 11 conveyed from the sheet feeding device 10 .

In the image forming unit 21, for example, full-line heads 21A, 21B, 21C, and 21D for four colors are arranged so as to face the conveying guide member 22 from the upstream side in the sheet material 11 conveying direction. The heads 21A, 21B, 21C, and 21D apply liquids of black K, cyan C, magenta M, and yellow Y to the sheet material 11, respectively. The kind and number of colors are not limited to this. The inkjet printer 20 includes a control section 200 . The control unit 200 controls operations of components included in the inkjet printer 20 . The controller 200 may control the operation of the drying device 30, which will be described later.

The drying device 30 is a device that dries liquid such as treatment liquid and liquid ink adhered to the sheet material 11 . A drying section 300 and a control section 250 are provided. These will be detailed later.

The sheet winding device 40 is a device that winds and collects the sheet material 11 on which an image is formed and dried by the drying device 30 . It has guide rollers 41 and 42 , a discharge roller 43 and a take-up roller 44 .

With the above configuration, the sheet material 11 is fed from the main winding roller 12 of the sheet feeding device 10, and is sent out by the conveying roller 13 onto the conveying guide member 22 arranged facing the image forming section 21, where the sheet material 11 is guided. It is guided and transported by the member 22 . The sheet material 11 to which the liquid has been applied by the image forming section 21 passes through the drying device 30 and is guided by guide rollers 415 and 416 . Then, the sheet is sent by a discharge roller 414 provided in the sheet winding device 40 and wound up by a winding roller 405 .

The drying device 30 of this embodiment is a device that evaporates moisture by applying thermal energy such as electric heat, infrared rays, or hot air. Inside the drying device 30 , vapor such as vaporized processing liquid and liquid ink is generated, and this vapor may condense inside the drying device 30 and liquefy. If the liquid generated by this dew condensation adheres to the sheet material 11, it may stain the formed image, so it should be discharged outside the drying device 30. FIG. The liquid discharged from the drying apparatus 30 may be stored in a waste liquid tank as a waste liquid, or may be reused as a liquid within the apparatus if possible. In the following description, it is assumed that the liquid is treated as a waste liquid.

In particular, the drying device 30 used in the printing system 100 that prints at high speed is preferably one that can dry a large amount of the sheet material 11 in a short time. In this case, the processing liquid (processing liquid for improving the image quality may be supplied to the sheet material 11 prior to image formation) and the amount of vapor due to vaporization of the liquid ink also increase. Condensation will also occur at many points. If a large amount of waste liquid generated in various places cannot be collected normally, a large amount of waste liquid is generated inside the drying device 30, staining the sheet material 11, and destabilizing the operation of the drying device 30. or

Therefore, in the drying device 30 according to the present embodiment, a recovery means for recovering the liquid liquefied by condensation inside the drying device 30, a drain pipe for draining the liquid from the recovery means, and a drain pipe and a pump for sending the liquid through, and forcibly recovering the liquid by the pump. Furthermore, a plurality of recovery means are provided, and a switching means for switching which one of them is connected to the pump is provided. As a result, the liquid can be collected from various locations, and the cost can be reduced by using the pump in common.

FIG. 2 is a diagram showing the internal configuration of the drying section 300 viewed from the front side. The drying unit 300 provided in the drying device 30 dries the sheet material 11 to be dried while conveying it in the direction indicated by the white arrow in the drawing. The drying unit 300 includes heating rollers 31 (31A to 31J), which are ten heating members that heat the sheet material 11 by contacting the surface opposite to the liquid-applied surface of the sheet material 11, and the sheet material 11. A heating drum 32 that heats the sheet material 11 by contacting the surface opposite to the surface to which the liquid is applied, and a pressing roller 33 (33A to 33J) that presses the sheet material 11 against the heating roller 31 (31A to 31J). ing.

The drying section 300 includes a plurality of air blowing devices 34 for blowing air onto the opposite side of the sheet material 11 heated by the heating roller 31 and the heating drum 32 . The air blown onto the sheet material 11 from the air blowing device 34 may be the air inside the drying device 30 or the air taken in from outside, and may not be particularly heated air. The air blowing device 34 is connected to an exhaust duct 362 on the back side of the device, and has a configuration for blowing air onto the sheet material 11 and sucking air containing steam around the sheet material 11 and exhausting the air.

FIG. 3 is a perspective view of the air blowing device 34 viewed from the rear side in such a posture that the surface of the air blowing device 34 facing the sheet can be seen. A surface facing the sheet is formed with an intake port 341d that is an opening for sucking gas including steam from the sheet material 11 . Also, a blowing slit 341b for blowing air onto the sheet material 11 is formed. A rear side plate 343 positioned on the rear side of the device is provided with three openings, and three air passage portions extending to the front side plate 342 on the opposite side corresponding to the three openings are formed inside. ing. Air is blown into the central opening of the three openings as indicated by the black arrow B, and the central air flow path becomes an air supply path connected to the blowing slit 341b. Air is exhausted from the openings on both sides as indicated by white arrows A, and the air flow paths on both sides form an exhaust path connected to the intake port 341d.

A tube joint 344 as a waste liquid recovery port is arranged on the rear side plate 343 . This is for collecting the waste liquid caused by the dew condensation generated in the exhaust passage of the air blowing device 34 . A waste liquid tube is connected to this tube joint. This tube joint or tube is part of the waste collection arrangement. The tube joint 344 is arranged at a position where the corresponding exhaust flow path takes the lowest position when the air blowing device 34 is installed in the drying section 300 . In addition, the inner wall surface portion of the exhaust flow path connected to the tube joint 344 is configured so as to be inclined toward the rear side plate 343 side.

An exhaust duct for exhausting the air (including steam) in the drying device 30 is provided on the back side of the air blowing device 34 . Collection of the waste liquid due to dew condensation generated in the exhaust duct can be performed by arranging a tube joint as a waste liquid collection port in a part of the exhaust duct.

The drying section 300 also has a waste liquid collecting plate 35 around the air blowing device 34 . The waste liquid collecting plate 35 collects liquefied dew condensation generated on the exterior of the air blowing device 34 so as not to fall into the sheet material 11 or the inside of the device. The air blowing devices 34 are arranged below the respective air blowing devices 34 in the direction of gravity so that the waste liquid (condensed liquid) does not drop. The waste liquid recovery plate 35 is also formed with, for example, a gutter at the lowest position. The gutter has a slight downward slope toward one end, and waste liquid that has fallen into the gutter moves to the one end. A tube joint, which is a waste liquid recovery port, is arranged at this end.

As described above, the drying device 30 according to this embodiment includes a plurality of waste liquid recovery ports. Further, as shown in FIG. 2, a waste liquid recovery section 310 is provided as a configuration for controlling the operation of recovering the waste liquid caused by condensation generated in the drying section 300 from each waste liquid recovery port to the waste liquid tank 330 . The waste liquid recovery unit 310 is arranged near the bottom inside the drying device 30 . As a result, the vapor generated in the drying device 30 that has condensed into waste liquid is easily collected in the waste liquid tank 330 by the action of gravity.

FIG. 4 is a configuration diagram illustrating a detailed configuration of the waste liquid recovery unit 310. As shown in FIG. The waste liquid recovery unit 310 also functions as a control unit that controls the recovery operation of the waste liquid from the plurality of waste liquid recovery ports 320 such as the tube joint 344 of the rear side plate 343 . The waste liquid recovery unit 310 includes a switching valve 301 , a waste liquid pump 302 and a pressure sensor 303 . The waste liquid recovery port 320 is also an element that constitutes the recovery means.

The switching valve 301 is a device including a valve that switches connections between the plurality of waste liquid recovery ports 320 and the waste liquid pump 302 . The switching valve 301 outputs any one of a plurality of input sections 301a connected to a plurality of waste liquid recovery ports 320 via a waste liquid tube 321, one output section 301b connected to the waste liquid pump 302, and a plurality of input sections 301a. and a switching unit 301c for switching between connecting to the unit 301b. The switching valve 301 constitutes switching means.

The waste liquid pump 302 is a pump that is connected to the output portion 301 b of the switching valve 301 , causes the waste liquid to flow from each waste liquid collection port 320 , and pumps it to the waste liquid tank 330 .

The pressure sensor 303 is a sensor that measures the pressure between the output portion 301 b of the switching valve 301 and the waste liquid pump 302 . The pressure sensor 303 outputs a predetermined signal (pressure detection result signal) according to the measured pressure. The pressure detection result signal is based on the measurement result of the pressure sensor 303 and indicates whether the waste liquid is not collected (cannot be collected) or is being collected (collected). is a signal that can distinguish between

Each operation of the switching valve 301 , the waste liquid pump 302 , and the pressure sensor 303 may be controlled by the control section 200 provided in the inkjet printer 20 . In this case, the switching valve 301 , the waste liquid pump 302 and the pressure sensor 303 are connected to a control signal line or the like as a configuration for receiving control signals from the control section 200 . Then, according to a control signal from the control section 200, a predetermined operation is performed at a predetermined timing. A pressure detection result signal from the pressure sensor 303 is also output to the control unit 200 .

Further, the drying device 30 may be provided with a control section 250 (see FIG. 1). In this case, the control unit 250 may be configured to operate in conjunction with the control unit 200 of the inkjet printer 20 and control the operations of the switching valve 301 , the waste liquid pump 302 and the pressure sensor 303 .

In the example of FIG. 4, a plurality of switching valves 301 are provided, and the waste liquid recovery ports 320 for each switching valve 301 are divided into a certain number (three in the illustrated example) to form recovery port groups. This collection port group can be a location group in which collection ports that are close in position are grouped together.

FIG. 5 shows a specific example of the switching valve 301. As shown in FIG. This switching valve 301 is a rotary valve. A rotor 312, which is a hollow rotating member (switching leak valve), is coaxially inserted into a cylindrical housing 311 closed at both ends with a gap 313 between the inner surface of the housing 311 and rotatable. The housing 311 is formed with input portions 301a (through holes) to which waste liquid tubes 321 from the three waste liquid collection ports 320 are connected. The number of connected waste liquid recovery ports, that is, the number of input units 301a is not limited to three, and may be two or four or more.

A receiving port 314 is formed as a through hole at a portion of the rotor 312 that corresponds to the input portion 301a in the axial direction. The hollow inside of the rotor 312 is the output portion 301b of the rotary valve. Specifically, this hollow interior is connected to the waste liquid pump 302 . A leak prevention member 315 such as an O-ring is provided around the receiving port 314 on the surface of the rotor 312 to seal against the inner surface of the housing 311 to prevent leakage. The leak prevention member 315 is generally made of an elastic member in order to exhibit good sealing performance.

Rotation of the rotor 312 causes the leak prevention member 315 to rotate while sliding on the inner peripheral surface of the housing, and can be made to take the following rotational positions. That is, the rotor 312 is at a rotational position in which the receiving port 314 of the rotor 312 faces the input portion 301a of one of the waste liquid recovery ports 320, and the input portion 301a is connected to the output portion 301b through the receiving port 314. FIG. In addition, it is also possible to set any input portion 301a to a rotational position in which none of the input portions 301a faces the receiving port 314 and is cut off from the output portion 301b.

FIG. 5(a) shows a state in which the input portion 301a corresponding to the waste liquid recovery port 320 on the upper side (directly above) in the figure is in a rotational position connected to the output portion 301b. By operating the waste liquid pump 302 in this rotational position, the waste liquid can be recovered as indicated by the arrow X. FIG. FIG. 5(b) shows that any input section 301a is in a rotational position in which it is disconnected from the output section 301b. Arrow Y indicates an example of the direction of rotation.

The switching valve 301, which is a rotary valve, is a connecting/disconnecting means for switching between connection and disconnection between the recovery means and the pump using a mechanism involving sliding. It has been found that the following problems arise when cutting and disconnecting with such sliding. Waste liquid is collected by connecting to multiple waste liquid ports and driving a pump, but with normal printing density and ink amount, no condensation occurs and no waste liquid occurs. This is for the following reasons.

During the operation of the drying device 30, the temperature inside the drying section is high and the saturated vapor pressure is also high. In addition, in the air blowing device 34, gas including vapor from the sheet material 11 is sucked from the intake port 341d and discharged to the outside of the device through the duct (in some cases, the gas is discharged after the liquid is removed with a moisture absorbing material). ing). Therefore, the printing speed is faster than usual, and the amount of ink applied to the sheet material 11 (the amount of ink used for printing) is not too large. be.

In this way, the inside of the switching valve is dry without the generation of waste liquid, and when the switching operation is performed in the absence of liquid, the leak prevention member 315 provided on the rotor 312 slides on the dry inner surface of the housing 311 (the inner surface of the switching valve). will move. As a result, early deterioration of the leak prevention member 315 (especially when it is an elastic member) is caused, and the switching valve has a short life. This problem is not limited to rotary valves, but can occur in any connecting/disconnecting means that uses a mechanism that involves sliding at a location where waste liquid may exist.

In order to solve the above problem, in the present embodiment, it is determined whether or not to perform the draining operation that accompanies the operation of the connecting/disconnecting means based on the liquid amount related information at the sliding portion. Specifically, information about the amount of liquid to be applied to the object is used as the liquid amount-related information. The information on the liquid application amount includes at least one of printing speed, upper limit of ink application amount, and print density. The printing speed is the conveying speed of the sheet material. In a printing system that allows the user to switch the transport speed, the faster the transport speed, the greater the amount of ink brought into the drying device 30 via the sheet material 11 .

The upper limit of the amount of ink to be applied is set by the total ink amount control section normally provided in the image processing section together with the color matching section, color conversion section, γ conversion section/gradation processing section, rendering processing section, ink amount calculation means, etc. is. The total ink amount regulation unit calculates the amount of ink from the image data of each nozzle channel of the print head (printer engine), obtains the total amount of ink for each page, and performs processing to keep the total amount of ink within a predetermined regulation value. If the user wishes to print with reduced ink consumption, the regulation value can be lowered. Conversely, when using a sheet material that requires a large amount of ink to obtain a desired image quality, the upper air regulation value can be increased based on the sheet material selection information by the user. As the upper limit of ink application amount increases, the amount of ink brought into the drying device 30 via the sheet material 11 increases.

The higher the print density, the greater the amount of ink brought into the drying device 30 via the sheet material 11 . This print density can be substantially calculated by ink amount calculation means provided in the image processing section. This ink amount calculation means calculates the ink amount for each page from the data assigned to each nozzle channel. The print density may be obtained by converting per area. Instead of the print density, the ink amount itself calculated by the ink amount calculating means may be used.

FIG. 6 is a flow chart of control using the printing speed and the upper limit amount of ink application among the above liquid presence/absence information. This flowchart exemplifies the flow of the waste liquid collecting operation that is executed when the printing process in the inkjet printer 20 is started.

When the printing process is started, or when the printing process is started, the upper limit amount of ink applied (ink limit value) satisfies a predetermined threshold value or more, or the printing speed satisfies a predetermined threshold value or more. (S601). If this threshold value is equal to or greater than the threshold value, dew condensation occurs due to the continuation of the printing process for the "predetermined time", and the liquid resulting from the dew condensation slides on the sliding portion of the switching valve 301, that is, the leak prevention member 315. It has been experimentally confirmed in advance that the inner surface of the housing 311 is wetted.

If both are less than the threshold (S601/NO), the waste liquid collection process is terminated without doing anything. If any of them is equal to or greater than the threshold (S601/YES), S602 is looped until a predetermined time elapses after the printing process is started (S602/NO). "Predetermined time" is, for example, 30 minutes. During this predetermined time, the liquid resulting from condensation reaches the sliding portion of the switching valve 301 and wets the inner surface portion of the housing 311 on which the leak prevention member 315 slides. This inner surface portion corresponds to the sliding portion. Further, the determination result of S602 is liquid presence/absence information.

During this "predetermined time", the rotor 312 takes the home position. The home position is a rotational position in which all the input portions 301a are blocked from the output portion 301b and the outer peripheral surface of the rotor 312 can receive the liquid caused by condensation from all the input portions 301a. For example, it is the rotational position shown in FIG. 5(b). While this home position is taken, liquid due to condensation is received on the outer peripheral surface of the rotor 312, and the liquid adheres to the inner surface portion of the housing 311 on which the leak prevention member 315 slides and the leak prevention member 315 itself.

When the predetermined time has passed after the start of the printing process (S602/YES), the rotor 312 at the home position is rotated, and first, one of the waste liquid recovery ports 320 connected to the switching valve 301 is recovered. The input section 301a connected to the port 320 and the output section 301b are connected (S603). As the rotor 312 rotates, the leak prevention member 315 rubs against the inner surface of the housing 311. Since the inner surface or the leak prevention member 315 itself is wet with liquid, deterioration due to sliding can be suppressed.

Next, the waste liquid pump 302 is operated for a predetermined time to recover the waste liquid from the waste liquid recovery port 320 (the first waste liquid recovery port 320) connected to the output section 301b (S604). The “predetermined time” for operating the waste liquid pump 302 is, for example, 10 seconds. After operating the waste liquid pump 302 for 10 seconds, the process proceeds from S604 to the next process.

Subsequently, a process of determining whether or not the waste liquid recovery operation (S604) has been performed for all of the waste liquid recovery ports 320 is executed (S605). If there is an unexecuted waste liquid recovery port 320 (S605/NO), the switching valve 301 sequentially switches connection to the unexecuted waste liquid recovery port 320 (S606). After the switching operation in the switching valve 301 is completed, the process proceeds to S604.

The operations of S 604 , S 605 and S 606 are repeated for all waste liquid collection ports 320 . As a result, waste liquid can be recovered from all the waste liquid recovery ports 320 . After the waste liquid recovery operation from all the waste liquid recovery ports 320 is executed (S605/YES), the switching valve 301 is switched to the home position (S607).

Thereafter, the process returns to S601 until the print process is completed (S608/NO). When the printing process ends (S608/YES), the waste liquid collection process also ends. Therefore, the process is executed each time the "predetermined threshold time" (30 minutes) elapses while the print process is being executed.

As described above, according to the waste liquid recovery process in the drying device 30 according to the present embodiment, the waste liquid can be recovered periodically while the printing process is being executed. As a result, it is possible to prevent waste liquid due to dew condensation from overflowing into the apparatus and causing problems.

In the example shown in FIG. 4, the waste liquid recovery port 320 and the output section 301b are simultaneously connected to all the switching valves 301 consisting of a plurality of rotary valves to which the three waste liquid recovery ports 320 are respectively connected, and the waste liquid pump 302 Waste liquid may be simultaneously collected from the connected waste liquid collection port 320 . Alternatively, the switching valve 301 connecting the waste liquid recovery port 320 to the waste liquid pump 302 may be switched sequentially.

FIG. 7 is a configuration diagram of a modified example of the waste liquid recovery unit. In this modification, a three-way valve 304 as connection switching means is provided between the two switching valves 301 and the waste liquid pump 302 . In this modified example, in the initial leak check operation performed before starting the image forming operation in the inkjet printer 20, the leak check is performed with one pressure sensor 303 in the waste liquid recovery unit 310 having a plurality of switching valves 301. Therefore, it is possible to relatively easily identify the switching valve 301 that is out of order.

As shown in FIG. 4, when a leak check is performed with a single pressure sensor 303 in a waste liquid recovery unit 310 having a plurality of switching valves 301, it is not possible to determine which switching valve is malfunctioning. It took time to check the switching valves one by one. Therefore, a switchable three-way valve is provided at the branch point of the piping between the switching valve and the waste liquid pump so that the pressure can be checked individually in the line of a certain switching valve and the line of the other switching valve. This makes it possible to determine which switching valve has failed.

FIG. 8 is a flow chart of an initial leak confirmation operation for identifying a failed switching valve that is an abnormality target. First, the input section 301a is cut off from the output section 301b for all switching valves 301 connected to all the three-way valves 304 that share the pressure sensor 303 (S801). Except for the first target three-way valve 304, the other three-way valves 304 shut off the pressure sensor 303 side (waste liquid pump 302 side). First, for the three-way valve 304 to be examined, one of the two connected switching valves 301 to be checked for failure is connected to the pressure sensor 303 side.

Subsequently, the suction operation of the waste liquid pump 302 is started (S802). Subsequently, the measurement result of the pressure sensor 303 is detected (S803). If the measurement result of the detected pressure exceeds the preset pressure threshold (S804/YES), it can be determined that there is no liquid leakage or clogging in the waste liquid flow path, and the pressure sensor 303 is normal. A pressure detection result signal indicating that there is a pressure is sent out (S805). After that, the waste liquid pump 302 is stopped (S806).

The pressure threshold is, for example, "minus 10 kPa". If the measurement result of the pressure sensor 303 is lower than minus 10 kPa, it can be determined that the waste liquid flow path between the switching valve 301 and the waste liquid pump 302 is normal.

In S804, if the pressure threshold is not exceeded (S804/NO), it is determined whether or not the elapsed time from the start of operation of the waste liquid pump 302 exceeds a preset threshold time (S807). If the threshold time is not exceeded (S807/NO), the process returns to S803.

If the threshold time is exceeded (S807/YES), it can be determined that some kind of abnormality has occurred. In this case, the pressure sensor 303 sends out a pressure detection result signal (abnormality notification signal) that indicates abnormality (S808). After that, the waste liquid pump 302 is stopped (S806).

It is determined whether or not to execute the leak check for the switching valves 301 other than the switching valves 301 checked in the above steps (S809). If it is determined that the leak check is to be performed for the other switching valve 301 (S809/YES), the other switching valve 301 is the other switching valve 301 connected to the three-way valve 304 common to the previous leak check target. switches the three-way valve 304 to connect the other switching valve 301 to the pressure sensor 303 side. Different from this, when the switching valve 301 for executing the next leak check is connected to another three-way valve 304 (referred to as the next check three-way valve), the three-way valve connected to the pressure sensor 303 side is The three-way valve 304 at that time is switched to the next confirmation three-way valve 304, and only one of the two switching valves 301 connected to this next confirmation three-way valve 304 is connected to the pressure sensor 303 side. make sure to Thereafter, the above leak confirmation is repeated until there are no switching valves to be checked for leak in S809 (S809/NO).

As described above, according to the initial leak confirmation process in the drying device 30 according to the present embodiment, it is possible to reliably confirm that the waste liquid recovery mechanism is operating normally before executing the image forming process. In addition, in a configuration having a plurality of switching valves, it is possible to identify the failure point without the need for service personnel to check.

FIG. 9 is an explanatory diagram of a waste liquid recovery unit 310 according to a modification. The waste liquid recovery unit 310 according to this modification uses one of the plurality of waste liquid recovery ports 320 connected to the switching valve 301 as the lubricating liquid injection port 325 . The lubricating liquid injection port 325 is supplied with a lubricating liquid, which is a wetting liquid contained in a tank or the like. A connection/disconnection switching valve 326 such as an electromagnetic valve is provided between the switching valve 301 and the lubricant injection port 325 . The lubricating fluid injection port 325 is installed above (preferably directly above) the switching valve 301, and arranged at a position where it drops by its own weight. The connection/disconnection switching valve 326 is opened, and the rotor 312 is rotated for a certain period of time in a state in which the lubricating fluid enters the housing 311 through the through hole, which is the input portion 301a, as indicated by the arrow Z. As a result, the lubricating liquid can be transmitted along the inner wall, and the inner surface can be wetted, so that the leak prevention member 315 slides well. Ordinary water can be used as the lubricating liquid, but is not limited to this. The above configuration constitutes the means for wetting the sliding portion or the means for supplying the wetting liquid.

FIG. 10 is a flow chart of control for periodically wetting the inner wall of the switching valve 301 (hereinafter referred to as lubricating liquid application control). It is executed at the start of the maintenance operation, which will be described later. First, it is determined whether or not a certain period of time or more has passed since the previous injection (S1001). If the predetermined time or more has passed (S1001/YES), the connection/disconnection switching valve 326 between the lubricating fluid injection port 325 and the switching valve 301 is opened for a predetermined time. The lubricating fluid flows into the switching valve 301 while it is open. At this time, by rotating the rotor 312 of the switching valve 301 for a certain period of time, the lubricating liquid is spread over the entire inner wall surface.

FIG. 11 is an example of maintenance operation. 3 illustrates the flow of processing operations when performing maintenance on the waste liquid recovery mechanism. This maintenance operation is performed by the user operating the drying device 30 and the operation panel of the inkjet printer 20 .

When the maintenance operation is started, first, the input section 3011 and the output section 3012 connected to one waste liquid recovery port 320 among the plurality of waste liquid recovery ports 320 connected to the switching valve 301 are connected. Then, the corresponding input valve is opened and the other input sections 3011 are closed (S1101). First, the input portion 3011 and the output portion 3012 corresponding to the first waste liquid recovery port 320 are connected to open the corresponding input valve, and the other input valves are closed.

Subsequently, the suction operation of the waste liquid pump 302 is started (S1102). Subsequently, the measurement result of the pressure sensor 303 is detected (S1103). If the measurement result of the detected pressure exceeds the preset pressure threshold (S1104/YES), the waste liquid recovery operation in the waste liquid recovery port 320 corresponding to the input section 3011 connected to the switching valve 301 is performed normally. It can be determined that there is a condition to obtain. Therefore, the pressure sensor 303 sends out a pressure detection result signal indicating normality (S1105). After that, the waste liquid pump 302 is stopped (S1106).

Subsequently, it is determined whether or not the waste liquid recovery operation has been executed for all the waste liquid recovery ports 320 (S1107). If there is an unexecuted waste liquid recovery port 320 (S1107/NO), the switching valve 301 switches connection to the unexecuted waste liquid recovery port 320, and after the switching operation in the switching valve 301 is completed, the process proceeds to S1102. (S1108).

In S1104, if the measurement result of the detected pressure does not exceed the pressure threshold (S1104/NO), whether or not the elapsed time after starting the operation of the waste liquid pump 302 exceeds a preset threshold time is determined (S1109). If the threshold time is not exceeded (S1109/NO), the process returns to S1103.

If the threshold time is exceeded (S1109/YES), it can be determined that the waste liquid recovery operation in the waste liquid recovery port 320 corresponding to the input section 3011 to which the switching valve 301 is connected is in an abnormal state. Therefore, the pressure sensor 303 sends out a pressure detection result signal indicating the abnormality (S1110). After that, the waste liquid pump 302 is stopped (S1106).

The above processing is repeated until all the waste liquid collection ports 320 are executed. If the maintenance operation has been performed for all the waste liquid recovery ports 320 (S1107/YES), the switching valve 301 is switched to the home position (S1111), and the maintenance operation ends.

As described above, according to the maintenance process in the drying device 30 according to the present embodiment, it can be reliably confirmed that the state of the waste liquid recovery mechanism in the drying device 30 is normal. By performing the lubricating liquid application control in FIG. 10 prior to such a maintenance operation, deterioration of the leak prevention member caused by rotating the rotor 312 while the inside of the switching valve 301 is dry can be suppressed. Note that the lubricating liquid application control in FIG. 10 may be appropriately executed separately from the maintenance operation as shown in FIG. 11 .

Furthermore, the configuration for lubricating liquid application in FIG. 9 and the lubricating liquid application control in FIG. 10 can be used together with the control in FIG. In this case, in S601 in the control of FIG. 6, the elapsed time from the previous lubricating fluid injection due to the execution of lubricating fluid application is also taken into consideration, and the tooth sharpness recovery operation is performed also according to the elapsed time from the previous lubricating fluid injection. It is preferable to determine whether or not

What has been described above is only an example, and the present invention has specific effects in each of the following aspects.

The present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the technical scope of the invention. is the subject of the present invention. Although the above embodiment shows a preferred example, a person skilled in the art can realize various modifications from the disclosed contents. Such modifications are also included in the technical scope described in the claims.

For example, in the above-described embodiments, the liquid applied to the object to be dried was ink, but it is not limited to this. Solvents such as water and organic solvents, colorants such as dyes and pigments, functional-imparting materials such as polymerizable compounds, resins, and surfactants, biocompatible materials such as DNA, amino acids, proteins, and calcium, natural pigments, etc. Solutions, suspensions, emulsions, etc. containing food materials, etc. These are, for example, inkjet inks, surface treatment liquids, components of electronic elements and light emitting elements, liquids for forming electronic circuit resist patterns, three-dimensional modeling Liquids used for purposes such as material liquids may also be used.

10: Sheet supply device 11: Sheet material 12: Main winding roller 13: Conveyance roller 20: Ink jet printer 21: Image forming unit 22: Conveyance guide member 30: Drying device 31: Heating roller 32: Heating drum 33: Pressing roller 34: Air blowing device 35 : Waste liquid recovery plate 40 : Sheet winding device 41 : Guide roller 42 : Guide roller 43 : Discharge roller 44 : Winding roller 100 : Print system 200 : Control unit 250 : Control unit 300 : Drying unit 301 : Switching Valve 301a: Input section 301b: Output section 301c: Switching section 302: Waste liquid pump 303: Pressure sensor 304: Three-way valve 310: Waste liquid recovery section 311: Housing 312: Rotor 314: Receptacle 315: Leak prevention member 320: Waste liquid recovery port 321 : Waste liquid tube 325 : Lubricating liquid injection port 326 : Connection/disconnection switching valve 330 : Waste liquid tank 341a : Intake port 341b : Spray slit 341d : Intake port 342 : Front side plate 343 : Rear side plate 344 : Tube joint 362 : Exhaust duct 405 : Take-up roller 414 : Discharge roller 415 : Guide roller 416 : Guide roller 3011 : Input unit 3012 : Output unit

JP-A-11-014258

Claims (11)

A drying device for drying an object to which a liquid is applied,
a recovery means for recovering a liquid condensed and liquefied inside the drying device;
a drain pipe for draining the liquid from the recovery means;
a pump for sending the liquid through the drain pipe;
a connecting/disconnecting means for switching between connection and disconnection between the recovery means and the pump using a mechanism involving sliding,
A drying apparatus characterized in that the draining operation accompanied by the actuation of the connecting/disconnecting means is performed based on information related to the amount of liquid at the sliding portion. The drying apparatus of claim 1,
The drying apparatus is characterized in that the liquid amount-related information is liquid presence/absence information at the sliding location, and whether or not the liquid draining operation is performed is determined based on the presence/absence of the liquid. A drying device for drying an object to which a liquid is applied,
a recovery means for recovering a liquid condensed and liquefied inside the drying device;
a drain pipe for draining the liquid from the recovery means;
a pump for sending the liquid through the drain pipe;
a connecting/disconnecting means for switching between connection and disconnection between the recovery means and the pump using a mechanism involving sliding,
A drying apparatus according to claim 1, wherein the draining operation accompanied by the operation of the connecting/disconnecting means is performed based on information regarding the amount of liquid applied to the object. The drying apparatus of claim 3,
A drying apparatus, wherein the information on the liquid application amount includes at least one of a printing speed, an ink application upper limit amount, and a printing density. The drying apparatus according to any one of claims 1 to 4,
comprising a plurality of the recovery means,
The drying apparatus, wherein the connecting/disconnecting means is a switching means for switching which one of the plurality of recovery means is connected to the pump. The drying apparatus of claim 5,
A drying apparatus comprising a plurality of said switching means, and further comprising a means for identifying an abnormal target when an abnormality occurs in said plurality of said switching means. The drying apparatus of claim 6,
a pressure sensor that measures the pressure between the plurality of switching means and the pump;
The specifying means is configured by using connection switching means for selectively connecting the plurality of switching means provided between the plurality of switching means and the pressure sensor to the pressure sensor. drying equipment. The drying apparatus according to any one of claims 1 to 7,
A drying apparatus comprising a means for wetting the sliding portion. The drying apparatus of claim 8,
A drying apparatus, wherein said wetting means is means for supplying a wetting liquid connected between said collecting means and said cutting means. The drying apparatus of claim 8 or 9,
The drying device, wherein the wetting means performs a wetting operation at a preset timing. A printing device comprising the drying device according to any one of claims 1 to 10.

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