JP2009226811A - Transfer member and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a transfer medium prevented of which the temperature is prevented from rising even when a heat source of 200°C or higher is used, and an image forming device using the transfer medium. <P>SOLUTION: An ink drying drum 38 includes a plurality of disks 84 fixed to a rotary shaft 82. The surface area is increased by providing a clearance 95 between adjacent disks 84 and 84. Since the end faces of the disks 84 are equivalent to so-called heat sinks, a heat dissipation effect is obtained. Namely, by increasing the heat dissipation area of the ink drying drum 38, the temperature increase rate of the ink drying drum 38 is reduced. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a transport body that transports a recording medium and an image forming apparatus including the transport body.

  A drum for conveying a recording medium used in an image forming apparatus has various uses, and some drums do not want to raise the temperature. One example is an electrophotographic photosensitive drum, which is usually cooled by a fan, but has problems such as cost reduction, power saving, and compactness. Further, even if it is not an electrophotographic photosensitive drum, a rolling bearing is used for the rotating drum. Therefore, when the temperature around the drum exceeds 100 ° C., the grease for lubricating the bearing is softened, resulting in a failure.

  Therefore, for example, in Patent Document 1, a cylinder formed of an elastic member having an outer diameter larger than the inner diameter of the drum is inserted into the drum, and a slit is provided in the cylinder. It is in close contact. In addition, by providing fins on the inner surface of the cylinder and using a heat sink, the drum can be cooled without applying cooling air to the outer periphery of the drum.

Further, in Patent Document 2, an air suction impeller and a mixed flow impeller that allow air to strike the drum inner surface are provided inside the drum. By rotating integrally with the drum, the wind is sucked into the drum and Guide the drum to cool down.
JP 2005-10428 A JP 2007-101788 A

  However, in recent years, ink jet printers for printing presses use a technique for printing ink on a recording medium in a non-penetrating manner in order to achieve high definition. At this time, the problem is moisture drying, and it is necessary to dry much moisture in a short time as compared with normal offset printing or ink jet that penetrates the recording medium.

  For this reason, the recording medium transport drum in the drying section sometimes exceeds 200 ° C. by a heat source such as an IR heater, a halogen heater, or hot air. However, the temperature applied to the electrophotographic photosensitive drum is increased by the internal temperature of the fixing device. Contact with the recording medium that has received heat after single-sided fixing during printing is a heat source, both of which are heat sources at 100 ° C. or lower.

  When a heat source of 200 ° C. or higher is required, the method of Patent Document 1 does not have a function of guiding wind to the inner surface of the drum, and a cooling effect is insufficient when there is a heat source of 200 ° C. or higher. Further, the method of Patent Document 2 has a mechanism for guiding wind to the drum inner surface by drum rotation. However, when the rotation speed is low, a sufficient cooling effect cannot be obtained. Further, it seems that a rotational speed of at least 1000 rpm (usually about 100 rpm) is required to reduce the drum temperature to 100 ° C. or lower with respect to a heat source of 200 ° C. or higher, and is difficult to apply in an actual drive system.

  In view of the above facts, an object of the present invention is to obtain a transport body that can suppress a temperature rise even when a heat source of 200 ° C. or higher is used, and an image forming apparatus using the transport body.

  The invention according to claim 1 is a conveyance body that rotates and conveys a recording medium, and is provided with a shaft body that is rotatably supported, and a plurality of shaft bodies that are provided with a gap in the axial direction. And a disk whose surface is a conveyance surface of the recording medium.

  According to the first aspect of the present invention, a plurality of disks whose outer peripheral surfaces serve as recording medium conveying surfaces are provided on the shaft body rotatably supported with a gap in the axial direction of the shaft body. In this way, the transport body is composed of a plurality of disks, and the outer peripheral surface of the disk is the transport surface of the recording medium, so that the transport body is a cylindrical drum as compared with the case where the transport body is a cylindrical drum. Along with the rotation of the carrier, a heat dissipation effect can be obtained, and the temperature rise rate of the carrier can be reduced.

  When a cooling device such as a fan is used using a heat source of 200 ° C. or higher, there is a problem such as heat resistance, which further increases the cost compared with the case of using a 100 ° C. heat source, but a heat dissipation effect is obtained. As a result, the rate of temperature rise of the transport body can be reduced without adding a new device, so that the cost can be reduced.

  Moreover, a material can be changed with a shaft body and a disk. Furthermore, by providing a gap between the disks, the weight can be reduced correspondingly, and the load applied to the drive system for driving the transport body can be reduced, thereby saving power.

  According to a second aspect of the present invention, in the carrier according to the first aspect, a plurality of first through holes penetrating in the thickness direction of the disk are provided along the circumferential direction.

  In invention of Claim 2, the heat dissipation effect of a conveyance body can be raised by making a 1st through-hole penetrate in the thickness direction of a disk, and weight reduction can be achieved.

  According to a third aspect of the present invention, in the transport body according to the second aspect, the respective disks are connected together at the central portion.

  In invention of Claim 3, each disk is connected so that it may become united in the center part, for example, you may form an annular recessed part along the circumferential direction on the outer peripheral surface of a cylindrical body.

  Invention of Claim 4 is the conveyance body in any one of Claims 1-3, The connection member which connects the said disks was provided along the axial direction of the said shaft body, It is characterized by the above-mentioned. To do.

  In the invention according to claim 4, it is possible to prevent the disk from being deformed or shaken by providing the connecting member for connecting the disks along the axial direction of the shaft body. By making the surface of the connecting member flush with the outer peripheral surface of the disk, it is possible to reduce the deflection of the recording medium due to the blowing of wind on the outer peripheral surface of the carrier.

  The invention according to claim 5 is characterized in that in the transport body according to any one of claims 1 to 3, a cooling plate is provided that projects in a radial direction from the shaft body and connects the disks. .

  In the invention according to claim 5, by providing a cooling plate that protrudes in the radial direction from the shaft body and connects the disks, the area for heat dissipation can be increased as compared with the case where the cooling plate is not provided. In addition, the cooling effect of the transport body can be increased. By making the end surface of the cooling plate flush with the outer peripheral surface of the disk, it is possible to reduce the deflection of the recording medium due to the blowing of wind onto the outer peripheral surface of the carrier.

  The invention according to claim 6 is the conveying body according to claim 5, wherein the cooling plate provided on one surface of the disk and the cooling plate provided on the other surface are arranged in the circumferential direction of the shaft body. It is characterized by being displaced.

  Since the cooling plate is fixed to at least the disk, in the invention according to claim 6, the cooling plate is arranged by shifting the cooling plates in the circumferential direction of the shaft body on one surface and the other surface of the disk. The workability when fixing to the disk is improved. Further, as compared with the invention described in claim 5, it is possible to further reduce the deflection of the recording medium due to the blowing of hot air to the outer peripheral surface of the carrier.

  The invention described in claim 7 is characterized in that, in the transport body according to claim 5 or 6, a second through hole penetrating in the thickness direction of the cooling plate is provided.

  In the invention according to claim 7, by providing the second through-hole penetrating in the thickness direction of the cooling plate, there is an effect of suppressing wind generated by the rotation of the cooling plate by the rotation of the conveyance body.

  According to an eighth aspect of the present invention, there is provided an image forming apparatus comprising: a recording head that ejects droplets onto a recording medium; and a drying device that dries the droplets ejected from the recording head. The recording medium is transported by the transport body according to any one of 7 to 7.

  In the invention according to the eighth aspect, it is possible to obtain substantially the same effect as the effect of the invention according to any one of the first to seventh aspects. By reducing the weight of the conveyance body that conveys the recording medium, it is possible to reduce the load on the drive system that drives the conveyance body and to save power.

  According to a ninth aspect of the present invention, in the image forming apparatus according to the eighth aspect, the transport body is a drying transport body facing the drying apparatus.

  According to the ninth aspect of the invention, substantially the same effect as that of any one of the first to seventh aspects can be obtained. In particular, by applying to the drying transport body facing the drying device, the heat dissipation effect of the transport body can be used to reduce the temperature rise rate of the drying transport body due to the thermal energy emitted from the drying device. .

  Since this invention was set as the said structure, even when a 200 degreeC or more heat source is used, the temperature rise of a conveyance body can be suppressed.

  Hereinafter, an image forming apparatus provided with a conveyance body according to an embodiment of the present invention will be described.

First, the overall configuration of the image forming apparatus 10 will be described.
[Image forming apparatus]
As shown in FIG. 1, the image forming apparatus 10 according to the present embodiment feeds and feeds paper to the upstream side in the transport direction of a sheet as a recording medium (hereinafter referred to as “paper”). A portion 12 is provided. On the downstream side of the paper feeding / conveying unit 12, a processing liquid applying unit 14 for applying a processing liquid to the recording surface of the paper along the paper conveying direction, an image forming unit 16 for forming an image on the recording surface of the paper, An ink drying unit 18 that dries an image formed on the recording surface, an image fixing unit 20 that fixes the dried image on a sheet, and a discharge unit 21 that discharges the sheet on which the image is fixed are provided.

Hereinafter, each processing unit will be described.
(Paper feed section)
The paper feeding / conveying unit 12 is provided with a stacking unit 22 on which sheets are stacked, and downstream of the stacking unit 22 in the sheet conveying direction (hereinafter, the “sheet conveying direction” may be omitted). A paper feeding unit 24 is provided for feeding the papers stacked on the stacking unit 22 one by one.The paper fed by the paper feeding unit 24 is transported by a plurality of pairs of rollers 26. After passing through the part 28, it is conveyed to the treatment liquid application part 14.
(Processing liquid application part)
In the treatment liquid application unit 14, a treatment liquid application drum 30 is rotatably disposed. The processing liquid coating drum 30 is provided with a holding member 32 that holds the paper by sandwiching the leading end of the paper, and the paper is held on the surface of the processing liquid coating drum 30 via the holding member 32. In this state, the sheet is conveyed downstream by the rotation of the treatment liquid coating drum 30.

  Note that an intermediate conveying drum 34, an image forming drum 36, an ink drying drum 38, and a fixing drum 40, which will be described later, are also provided with a holding member 32 in the same manner as the processing liquid coating drum 30. The holding member 32 transfers the paper from the upstream drum to the downstream drum.

  A processing liquid coating device 42 and a processing liquid drying device 44 are disposed above the processing liquid coating drum 30 along the circumferential direction of the processing liquid coating drum 30. The treatment liquid is applied to the surface, and the treatment liquid is dried by the treatment liquid drying device 44.

  Here, the treatment liquid reacts with the ink to aggregate the color material (pigment) and has an effect of promoting separation of the color material (pigment) and the solvent. The treatment liquid application device 42 is provided with a storage portion 46 for storing the treatment liquid, and a part of the gravure roller 48 is immersed in the treatment liquid.

  A rubber roller 50 is disposed in pressure contact with the gravure roller 48, and the rubber roller 50 contacts the recording surface (front surface) side of the paper to apply the processing liquid. Further, a squeegee (not shown) is in contact with the gravure roller 48 to control the amount of treatment liquid applied to the recording surface of the paper.

  Ideally, the treatment liquid film thickness is sufficiently smaller than the droplets of the head droplets. For example, when the droplet volume is 2 pl, the average diameter of the droplets of the head droplet is 15.6 μm, and when the treatment liquid film thickness is thick, the ink dots float in the treatment liquid without contacting the recording surface of the paper. To do. In order to obtain a landing dot diameter of 30 μm or more with a droplet ejection amount of 2 pl, it is preferable to set the treatment liquid film thickness to 3 μm or less.

  On the other hand, in the treatment liquid drying device 44, a hot air nozzle 54 and an infrared heater 56 (hereinafter referred to as “IR heater 56”) are disposed close to the surface of the treatment liquid application drum 30. The hot air nozzle 54 and the IR heater 56 evaporate a solvent such as water in the processing liquid to form a solid or thin film processing liquid layer on the recording surface side of the paper. By thinning the treatment liquid in the treatment liquid drying step, the dots deposited by ink in the image forming unit 16 come into contact with the surface of the paper to obtain the required dot diameter, and react with the thinned treatment liquid. It is easy to obtain an action of agglomerating color materials and fixing to the paper surface.

In this way, the paper on which the processing liquid has been applied and dried on the recording surface by the processing liquid application unit 14 is conveyed to an intermediate conveyance unit 58 provided between the processing liquid application unit 14 and the image forming unit 16.
(Intermediate transport section)
An intermediate transport drum 58 is rotatably provided in the intermediate transport unit 58, and a sheet is held on the surface of the intermediate transport drum 34 via a holding member 32 provided in the intermediate transport drum 34. The sheet is conveyed downstream by the rotation of 34.
(Image forming part)
An image forming drum 36 is rotatably provided in the image forming unit 16, and a sheet is held on the surface of the image forming drum 36 via a holding member 32 provided on the image forming drum 36. The sheet is conveyed downstream by the rotation of 36.

  Above the image forming drum 36, a head unit 66 composed of a single-pass inkjet line head 64 is disposed adjacent to the surface of the image forming drum 36. In this head unit 66, at least the basic color YMCK inkjet line heads 64 are arranged along the circumferential direction of the image forming drum 36, and are formed on the processing liquid layer formed on the recording surface of the paper by the processing liquid coating unit 14. An image of each color is formed.

  The treatment liquid has the effect of aggregating the color material (pigment) and latex particles dispersed in the ink into the treatment liquid, and forms an aggregate that does not generate color material flow on the paper. As an example of the reaction between the ink and the treatment liquid, acid is contained in the treatment liquid, pigment dispersion is destroyed by PH down, and the color material bleeds using a mechanism of aggregation, color mixing between each color ink, liquid mixture at the time of ink droplet landing Avoids droplet-interference caused by

  The ink jet line head 64 performs droplet ejection in synchronization with an encoder (not shown) that detects the rotational speed disposed on the image forming drum 36, thereby determining the landing position with high accuracy and at the same time. Irregular droplet ejection can be reduced without depending on the shake, the accuracy of the rotary shaft 68, and the drum surface speed.

  The head unit 66 can be retracted from the upper part of the image forming drum 36, and maintenance operations such as cleaning the nozzle surface of the inkjet line head 64 and discharging the thickened ink, the head unit 66 is moved to the upper part of the image forming drum 36. It is carried out by evacuating from.

The sheet on which the image is formed on the recording surface is conveyed to an intermediate conveyance unit 70 provided between the image forming unit 16 and the ink drying unit 18 by the rotation of the image forming drum 36. Since the configuration is substantially the same as that of the intermediate conveyance unit 58, description thereof is omitted.
(Ink drying section)
An ink drying drum 38 (described later) is rotatably provided in the ink drying unit 18, and a hot air nozzle 72 and an IR heater are disposed above the ink drying drum 38 in the vicinity of the surface of the ink drying unit 18. A plurality of 74 are arranged.

  Here, as an example, the pair of IR heaters 74 arranged in parallel with the hot air nozzles 72 are alternately arranged so that the hot air nozzles 72 are arranged on the upstream side and the downstream side. In addition to this, a large number of IR heaters 74 are arranged on the upstream side to irradiate a large amount of heat energy on the upstream side to increase the temperature of moisture, and a large number of hot air nozzles 72 are arranged on the downstream side to blow off saturated water vapor. Also good.

  Here, the hot air nozzle 72 is arranged so that the blowing angle of the hot air is inclined toward the rear end side of the paper. Accordingly, the flow of hot air from the hot air nozzle 72 can be collected in one direction, and the paper is pressed against the ink drying drum 38 side, and the state where the paper is held on the surface of the ink drying drum 38 can be maintained. it can.

  With the hot air generated by the hot air nozzle 72 and the IR heater 74, the solvent separated by the color material aggregating action is dried in the paper image forming unit, and a thin image layer is formed.

  Although the warm air varies depending on the paper conveyance speed, it is usually set to 50 ° C. to 70 ° C., and the ink surface temperature is set to 50 ° C. to 60 ° C. by setting the temperature of the IR heater 74 to 200 ° C. to 600 ° C. It is set to be. The evaporated solvent is discharged together with air to the outside of the image forming apparatus 10, but the air is recovered. This air may be cooled by a cooler / radiator or the like and recovered as a liquid.

The sheet on which the image on the recording surface is dried is conveyed to an intermediate conveyance unit 76 provided between the ink drying unit 18 and the image fixing unit 20 by the rotation of the ink drying drum 38. Since the configuration is substantially the same as that of the intermediate conveyance unit 58, description thereof is omitted.
(Image fixing part)
An image fixing drum 40 is rotatably provided in the image fixing unit 20. In the image fixing unit 20, latex particles in a thin image layer formed on the ink drying drum 38 are heated / pressurized. And has a function of fixing and fixing on the paper.

  A heating roller 78 is disposed above the image fixing drum 40 in the vicinity of the surface of the image fixing drum 40. The heating roller 78 has a halogen lamp incorporated in a metal pipe made of aluminum or the like having a good thermal conductivity. The heating roller 78 applies heat energy equal to or higher than the Tg temperature of the latex. As a result, the latex particles are melted and pressed into the irregularities on the paper for fixing, and the irregularities on the image surface are leveled to obtain glossiness.

  A fixing roller 80 is provided on the downstream side of the heating roller 78. The fixing roller 80 is disposed in pressure contact with the surface of the image fixing drum 40 so as to obtain a nip force with the image fixing drum 40. I have to. Therefore, at least one of the fixing roller 80 and the image fixing drum 40 has an elastic layer on the surface and a uniform nip width with respect to the paper.

  The sheet on which the image on the recording surface is fixed by the above-described process is conveyed to the discharge unit 21 side provided on the downstream side of the image fixing unit 20 by the rotation of the image fixing drum 40.

  In this embodiment, the image fixing unit 20 has been described. However, the image fixing unit 20 is not necessarily required because it is sufficient that the image formed on the recording surface can be dried and fixed by the ink drying unit 18.

  Next, the drum according to the embodiment of the present invention will be described.

As shown in FIG. 1, in the processing liquid coating unit 14, the image forming unit 16, the ink drying unit 18, and the image fixing unit 20, the processing liquid coating drum 30, the image forming drum 36, the ink drying drum 38, and the fixing drum 40, respectively. However, since a plurality of hot air nozzles 72 and an IR heater 74 are provided in the ink drying unit 18, the surface temperature of the ink drying drum 38 is higher than that of the other drums. For this reason, the conveyance body according to one embodiment of the present invention will be described by applying it to the ink drying drum 38.
(First embodiment)
As shown in FIGS. 2 to 4, the ink drying drum 38 includes a rotating shaft 82 and a plurality (six in this case) of disks 84 that are fixed to the rotating shaft 82 and have the same outer diameter. The A large-diameter portion 86 is provided on one end side of the rotating shaft 82, and the key is provided along the axial direction on the outer peripheral surface of the rotating shaft 82 from the other end portion of the rotating shaft 82 to the large-diameter portion 86. A portion 88 is projected.

  On the other hand, the disk 84 is provided with circular through holes 90 (six in this case) that penetrate in the thickness direction of the disk 84 at a predetermined pitch along the circumferential direction of the disk 84. Further, the disk 84 is provided with a key groove 92 that can be engaged with the key portion 88. By engaging the key portion 88 of the rotating shaft 82 with the key groove 92, the disk 84 is attached to the rotating shaft 82. It is prevented from rotating and rotates together with the rotating shaft 82.

  Further, a cylindrical spacer 94 is disposed between the disk 84 and the disk 84 so that a gap 95 is provided. The spacer 94 is also formed with the same keyway 96 as the disk 84, is prevented from rotating around the rotating shaft 82, and rotates together with the rotating shaft 82.

  Further, on the outer peripheral surface of the disk 84, there are provided mounting recesses 98 (six in this case) penetrating in the axial direction of the disk 84 at predetermined intervals along the circumferential direction of the disk 84. The positions of the mounting recesses 98 of the plurality of disks 84 coincide with each other in the axial direction of the ink drying drum 38 in a state where the key groove 92 of the disk 84 is engaged with the key portion 88 of the rotating shaft 82. These mounting recesses 98 can be fitted with a single bar-shaped connecting member 100, and the disks 84 are connected and integrated with the connecting member 100 with a gap 95.

  A housing recess 106 that can receive the head 102A of the fixing screw 102 is formed on the surface of the connecting member 100, and a screw hole 108 into which the fixing screw 102 can be screwed is formed at the center of the housing recess 106. Has been. Further, a screw hole 110 into which the fixing screw 102 can be screwed is formed on the bottom surface of the mounting recess 98. When the fixing screw 102 is screwed into the screw hole 108 and the screw hole 110, the connecting member 100 is attached to the mounting recess 98. Fixed within.

  In a state where the connecting member 100 is fixed to the mounting recess 98, the surface of the connecting member 100 is substantially flush with the outer peripheral surface of the disk 84. Further, the head 102A of the fixing screw 102 in the accommodating recess 106 provided in the connecting member 100 is prevented from protruding from the surface of the connecting member 100 in a state where the fixing screw 102 is fixed.

  Next, a method for manufacturing the ink drying drum 38 will be described.

  First, the key groove 92 of the disk 84 is engaged with the key portion 88 of the rotating shaft 82, and the disk 84 is moved along the axial direction of the rotating shaft 82. When the disk 84 comes into surface contact with the large-diameter portion 86, the movement of the disk 84 is restricted. Next, the key groove 96 of the cylindrical spacer 94 is engaged with the key portion 88 of the rotating shaft 82, and the spacer 94 is moved along the axial direction of the rotating shaft 82. When the spacer 94 comes into surface contact with the disk 84, the movement of the spacer 94 is restricted. Then, the above insertion operation is repeated so that the disk 84 and the spacer 94 are last in the order of the disk 84 and the spacer 94.

  The positions of the mounting recesses 98 formed on the outer peripheral surfaces of the six disks 84 in a state of being inserted through the rotating shafts 82 are aligned along the axial direction of the rotating shaft 82, and one mounting recess 98 is provided in each of these mounting recesses 98. The connecting member 100 is fitted. Next, the fixing screw 102 is screwed to fix the connecting member 100 to the disk 84. Finally, the annular flange 112 is fixed to the rotating shaft 82 and the disk 84 is prevented from coming off.

  Here, the rotating shaft 82 is preferably hardened steel or SUS440C, and it is preferable that the surface hardness of the bearing portion is HRC58 or higher by induction hardening. Further, the material of the disk 84 and the connecting member 100 is preferably an aluminum material in consideration of workability, assemblability, and weight reduction. In order to reduce the outer diameter change due to thermal expansion, it is possible to use iron or SUS material.

  Next, the operation of the carrier according to the present embodiment will be described.

  As shown in FIG. 2, the ink drying drum 38 includes a plurality of disks 84 fixed to the rotating shaft 82, and a gap 95 is provided between adjacent disks 84. Thereby, since the end surface of the disk 84 corresponds to what is called a heat sink with respect to the heat energy emitted from the hot air nozzle 72 and the IR heater 74, a heat radiation effect can be obtained. That is, by increasing the heat radiation area of the ink drying drum 38, the temperature increase rate of the ink drying drum 38 can be reduced.

  Further, in the case of a cylindrical drum, the air inlet / outlet is limited to the end surface of the cylindrical drum, and heat tends to be trapped inside, but by configuring the outer shape with a plurality of disks 84 as in this embodiment, Air can be caused to flow into a gap 95 provided between the disks 84 and 84, and the disk 84 can be directly cooled, so that the cooling efficiency is good.

  When a cooling device such as a fan is used using a heat source of 200 ° C. or higher, there is a problem such as heat resistance, and the cost is further increased compared to the case of using a heat source of 100 ° C., but the ink drying drum 38 is used. Since the temperature rise rate of the ink drying drum 38 can be reduced without adding a new device by suppressing the temperature rise itself and increasing the heat radiation effect of the ink drying drum 38 itself, Cost can be reduced.

  Further, since the weight can be reduced as compared with the case where a cylindrical drum is used, the load on the drive system for driving the ink drying drum 38 can be reduced, and the power can be saved. Further, by reducing the weight of the ink drying drum 38, it is possible to reduce the size of the motor that drives the ink drying drum 38, thereby reducing costs.

  Furthermore, by providing the through hole 90 in the thickness direction of the disk 84, the heat dissipation effect of the ink drying drum 38 can be increased, and the weight can be further reduced. Here, the shape of the through hole 90 is circular, but other shapes may be used.

  Further, in the present embodiment, the mounting recess 98 is formed in the outer peripheral surface of the disk 84, the connecting member 100 is fixed to the mounting recess 98, and the plurality of disks 84 are connected by the connecting member 100. Thereby, a deformation | transformation, a blurring, etc. of the disk 84 can be prevented.

  Further, in a state where the connecting member 100 is fixed to the mounting recess 98, the surface of the connecting member 100 is substantially flush with the outer peripheral surface of the disk 84, so that the connecting member 100 is not present. In addition, it is possible to reduce the deflection of the paper due to the blowing of air to the outer peripheral surface of the ink drying drum 38. Depending on the gap between the disk 84 and the disk 84, the surface of the connecting member 100 may not be substantially flush with the outer peripheral surface of the disk 84.

  Moreover, in this embodiment, since a material can be changed with the rotating shaft 82 and the disk 84, it can respond individually in consideration of a specification, cost, etc., and can aim at cost reduction.

  Here, a cylindrical drum having an outer diameter of 450 mm × a length of 800 mm and six disks having a width of 50 mm are used, and hot air of 70 ° C. and an IR heater of 600 ° C. are applied to the surface of the disk drum having a space between the disks of 100 mm. As a result of measuring the temperature of the drum when sprayed for 2 hours, the temperature was 105 ° C. for the cylindrical drum, but it was 50 ° C. for the disk drum, and it was 70 ° C. even after 10 hours.

  In other words, it was found that the ink drying drum 38 according to the present embodiment does not exceed 100 ° C. with 70 ° C. warm air and a 600 ° C. IR heater heat source. Accordingly, since the grease for bearing lubrication of the ink drying drum 38 is not softened with a hot air of 70 ° C. and a heat source of an IR heater of 600 ° C. or less, the durability of the rotary shaft 82 is enhanced.

  As described above, in the ink drying drum 38 in the present embodiment, the six discs 84 are provided on the rotating shaft 82, but it is only necessary to increase the heat radiation area of the ink drying drum 38, and the present invention is not limited to this.

For example, as shown in FIG. 5, an annular recess 116 may be provided on the surface of the cylindrical body 114 along the circumferential direction. A plurality of flange portions (disks) 117 are formed by forming the concave portions 116, and the above-mentioned mounting concave portions 98 (see FIG. 3) are formed in the end face of the flange portions 117, and the connecting member 100. The flange portion 117 is reinforced so as to be fixed. In this embodiment, since each flange part 117 is connected by the center part, an assembly operation | work is reduced compared with the case where the some disc 84 is used.
(Second Embodiment)
Next, the transport body according to the second embodiment will be described. In addition, description is abbreviate | omitted about the content substantially the same as 1st Embodiment.

  As shown in FIG. 6, three disks 84 are used, and a long plate-shaped cooling plate (so-called heat sink) 118 is provided between the disks 84 and 84. An insertion groove 122 is provided on the outer peripheral surface of the rotating shaft 120 along the axial direction of the rotating shaft 120 from one end side to the center of the rotating shaft 120.

  By inserting the cooling plate 118 into the rotating shaft 120 along the insertion groove 122, the cooling plate 118 is disposed so as to expand radially from the rotating shaft 120 in the radial direction. Here, eight cooling plates 118 are provided at a predetermined pitch along the circumferential direction of the disk 84.

  Further, an insertion groove (not shown) is provided along the axial direction of the rotating shaft 120 from the center portion to the other end portion of the rotating shaft 120, and the rotating shaft 120 rotates between one end side and the other end side. The position of the insertion groove is shifted along the circumferential direction of the shaft 120.

  That is, the cooling plate 118 fixed to one surface of the disk 84 located at the center between one end side and the other end side of the rotating shaft 120 and the cooling plate 124 fixed to the other surface, The positions are shifted in the direction (here, the cooling plate 118 and the cooling plate 124 are shifted by 22.5 degrees). The cooling plates 118 and 124 are provided with through holes 126 (three in this case) that penetrate in the thickness direction.

  Here, screw holes 128 and 130 are formed in the disk 84 and the cooling plate 118, respectively, and the fixing screw 132 can be screwed. The disks 84 are connected to each other by fixing the cooling plates 118 and 124 by the fixing screws 132. Further, the side end surfaces of the cooling plates 118 and 124 are flush with the outer peripheral surface of the disk 84, and hold the paper together with the outer peripheral surface of the disk 84.

  Next, a method for manufacturing the ink drying drum will be described.

  First, the disk 84 is inserted into the rotating shaft 120, and the disk 84 is fixed by a set screw (not shown) at the center of the rotating shaft 120. Next, the cooling plate 118 is inserted into the insertion groove 122 of the rotating shaft 120 from one end side of the rotating shaft 120. When the cooling plate 118 is moved along the insertion groove 122, the position of the insertion groove is changed at the center of the rotating shaft 120, and the movement of the cooling plate 118 is restricted. At this time, the cooling plate 118 is moved to the disk 84. In surface contact.

  Then, each cooling plate 118 is fixed to the disk 84 by a fixing screw 132. Next, the disk 84 is further inserted from one end side of the rotating shaft 120. The disk 84 is fixed to the cooling plate 118 with fixing screws 132. And the other end side of the rotating shaft 120 is also fixed with the fixing screw 132 in the order of the cooling plate 124 and the disk 84 as described above.

  Here, the material of the cooling plate 118 is preferably an aluminum material in consideration of workability and assemblability (weight). In order to reduce the outer diameter change due to thermal expansion, it is possible to use iron or SUS material.

  Next, the operation of the carrier according to the present embodiment will be described.

  As shown in FIG. 6, the cooling plates 118 and 124, which connect the disks 84 and hold the paper on the side end surfaces along the radial direction of the rotating shaft 120, are not provided. In comparison, the area for heat dissipation can be increased.

  For this reason, the cooling effect of the ink drying drum 134 can be further increased. Further, by making the side end surfaces of the cooling plates 118 and 124 flush with the outer peripheral surface of the disk 84, the outer periphery of the ink drying drum 134 can be compared with the case where the cooling plate 118, 124 is provided inside the outer peripheral surface of the disk 84. It is possible to reduce the deflection of the paper due to the wind blowing on the surface. Depending on the gap between the disk 84 and the disk 84, the side end surfaces of the cooling plates 118 and 124 may not be substantially flush with the outer peripheral surface of the disk 84.

  By the way, since the cooling plates 118 and 124 are fixed to the disk 84 by the fixing screws 132, the cooling plates 118 and 124 are disposed by shifting the cooling plate 118 and the cooling plate 124 along the circumferential direction of the rotating shaft 120. The workability at the time of fixing to the disk 84 is improved.

  Further, by disposing the cooling plate 118 and the cooling plate 124 along the circumferential direction of the rotating shaft 120, it is possible to further reduce the deflection of the sheet due to the blowing of hot air to the outer peripheral surface of the ink drying drum 134.

  On the other hand, the cooling plates 118 and 124 are provided with through holes 126 penetrating in the thickness direction. Accordingly, there is an effect of suppressing wind generated by the rotation of the cooling plates 118 and 124 by the rotation of the ink drying drum 134. Here, in order to reduce the influence of the wind on the paper, it is better that the through hole 126 is larger, and although not shown, it is more preferable to use punching metal.

  In this example, three disks 84 and eight cooling plates 118 and 124 are used between the disks 84 and 84. However, the heat radiation area can be changed by changing the number and width of the disks and cooling plates. Because it can, it is not limited to this.

  For example, as shown in FIG. 8, six disks 84 are used as in the first embodiment, and eight cooling plates 136 and 138 are disposed between the disks 84 and 84 (note that fixing screws are not shown). is doing). In this case, the cooling plate 136 and the cooling plate 138 are arranged in a staggered manner. That is, the cooling plate 136 and the cooling plate 138 are shifted by 22.5 deg.

  According to this, since the space between the disks 84 is narrower than in the second embodiment, there is less deflection of the paper due to the blowing of hot air. In addition, since the number of cooling plates 136 and 138 is increased as compared with the second embodiment, the heat dissipating effect is large, and the deflection of the paper due to hot air is small.

  In the above embodiment, the ink drying drums 38 and 134 have been described. However, according to the present invention, the weight of the drum for conveying paper can be reduced, so that the drive system for driving the drum can be used. Such a load can be reduced to save power. You may make it apply to another drum.

  In the above-described embodiment, the image forming apparatus that discharges ink and forms an image on a sheet has been described. However, the liquid to be discharged is not limited to ink. For example, drying for various industrial applications, such as forming bumps for component mounting by discharging molten solder onto the substrate, and forming EL display panels by discharging organic EL solution onto the substrate The present invention can be applied to all devices.

1 is an overall configuration diagram illustrating a configuration of an image forming apparatus according to an exemplary embodiment. It is a perspective view which shows the conveyance body which concerns on this 1st Embodiment. The conveyance body which concerns on this 1st Embodiment is shown, (B) is sectional drawing, (A) is a left view of (B). It is a partially exploded perspective view which shows the conveyance body which concerns on this 1st Embodiment. It is sectional drawing which shows the 1st modification of the conveyance body which concerns on this 1st Embodiment. It is a perspective view which shows the conveyance body which concerns on this 2nd Embodiment. It is sectional drawing which shows the conveyance body which concerns on this 2nd Embodiment. It is sectional drawing which shows the 1st modification of the conveyance body which concerns on this 2nd Embodiment.

Explanation of symbols

10 Image Forming Device 18 Ink Drying Unit (Drying Device)
38 Ink drying drum (conveyor)
66 Head unit (recording head)
72 Hot air nozzle (heating means)
74 IR heater (heating means)
82 Rotating shaft (shaft body)
84 Disc 90 Through hole (first through hole)
100 connecting member 114 cylindrical body (conveyance body)
117 Flange (disk)
118 Cooling plate 120 Rotating shaft (shaft body)
124 Cooling plate 126 Through hole (second through hole)
128 Screw hole 134 Ink drying drum 136 Cooling plate 138 Cooling plate

Claims (9)

A carrier for rotating and carrying a recording medium,
A shaft body rotatably supported;
A plurality of discs provided in the shaft body with a gap in the axial direction, the outer peripheral surface of which is a transport surface of the recording medium,
A carrier having the following characteristics.   The transport body according to claim 1, wherein a plurality of first through holes penetrating in a thickness direction of the disk are provided along a circumferential direction.   3. The carrier according to claim 2, wherein the disks are connected together at the center.   The transport body according to any one of claims 1 to 3, wherein a connecting member that connects the disks is provided along an axial direction of the shaft body.   The carrier according to any one of claims 1 to 3, further comprising a cooling plate that projects in a radial direction from the shaft and connects the disks.   The transport body according to claim 5, wherein the cooling plate provided on one surface of the disk and the cooling plate provided on the other surface are arranged so as to be shifted in the circumferential direction of the shaft body. .   The transport body according to claim 5 or 6, wherein a second through-hole penetrating in the thickness direction of the cooling plate is provided. An image forming apparatus comprising: a recording head that discharges droplets to a recording medium; and a drying device that dries droplets discharged from the recording head.
An image forming apparatus that transports a recording medium by the transport body according to claim 1.   The image forming apparatus according to claim 8, wherein the transport body is a transport body for drying facing the drying device.

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