ROLLER DEVICE AND PRINTER

A roller device includes a cylindrical body, a thermoelectric converter, a first heatsink and a second heatsink that are disposed adjacent to each other, and a press-fitting member. The thermoelectric converter is disposed on an inner peripheral surface of the cylindrical body. The first heatsink and the second heatsink each dissipate heat of the thermoelectric converter. The press-fitting member is disposed between the first heatsink and the second heatsink. The press-fitting member makes the thermoelectric converter be held between the cylindrical body and at least one of the first heatsink and the second heatsink.

TECHNICAL FIELD

The present disclosure relates to a roller device that can control temperature by using a thermoelectric converter such as a Peltier element and relates to a printer including the roller device.

BACKGROUND

Conventionally, in an offset printer of the flat plate method, there are used various types of rollers such as an ink roller, a plate cylinder, a blanket, and an impression cylinder. Regarding the ink roller among these rollers, a plurality of ink rollers are disposed between an ink storage to the plate cylinder to guide ink from the ink storage to the plate cylinder while being in rotational contact with ink. During this operation, temperature of each ink roller rises due to frictional heat between the roller and the ink. Therefore, the temperature of the ink rollers needs to be appropriately controlled to a temperature in conformity with a specification of the ink.

PTL 1 describes a configuration in which a ventilation device is used to flow air inside the ink roller to cool the ink roller. In more detail, the cylinder is configured by fitting an inner cylinder into an outer cylinder. On an inner peripheral surface of the inner cylinder, there are formed a plurality of heat dissipation fins. Further, on an outer circumferential surface of the inner cylinder, there are disposed electronic cooling elements. The outer cylinder is configured such that an inner diameter of the outer cylinder becomes large when the outer cylinder is heated. After the outer cylinder is expanded by heating, the inner cylinder whose outer circumferential surface is provided with the electronic cooling elements is inserted and fitted into the outer cylinder. After that, the outer cylinder shrinks by being cooled. In this manner, surfaces of the electronic cooling elements come into close contact with an inner peripheral surface of the outer cylinder by letting an inner diameter of the outer cylinder be small.

CITATION LIST

Patent Literature

SUMMARY

A first aspect of the present disclosure relates to a roller device. A roller device according to the first aspect includes a cylindrical body, a thermoelectric converter, a first heatsink and a second heatsink that are disposed adjacent to each other, and a press-fitting member. The thermoelectric converter is disposed on an inner peripheral surface of the cylindrical body. The first heatsink and the second heatsink each dissipate heat of the thermoelectric converter. The press-fitting member is disposed between the first heatsink and the second heatsink. The press-fitting member makes the thermoelectric converter be held between the cylindrical body and at least one of the first heatsink and the second heatsink.

In the roller device according to present aspect, by a really simple work, for example, by inserting a press-fitting member between the adjacent heatsinks, the heatsinks and a thermoelectric converter can be smoothly disposed in a cylindrical body.

A second aspect of the present disclosure relates to a printer. The printer according to the second aspect includes the roller device according to the first aspect and transfers ink onto a sheet-shaped print medium by using the roller device.

Since the printer according to the present aspect includes the roller device according to the first aspect, the same effect as in the first aspect can be provided.

As described above, the present disclosure can provide a roller device in which a thermoelectric converter and heatsinks can be smoothly disposed inside the cylindrical body by a simple work, and can provide a printer using the roller device.

An effect or a meaning of the present disclosure will be further clarified in the following description of the exemplary embodiment. However, the exemplary embodiment shown below is merely one example of implementation of the present disclosure, and the present disclosure is not at all limited to the example described in the following exemplary embodiment.

DESCRIPTION OF EMBODIMENT

Before an exemplary embodiment of the present disclosure is described, problems with the conventional art will be briefly described. In the configuration of PTL 1 described above, cumbersome and time-consuming work such as heating and cooling the outer cylinder is required when the inner cylinder is attached to the outer cylinder. Further, since the inner cylinder provided with the electronic cooling elements is fit into the outer cylinder, it is extremely difficult to appropriately fit the inner cylinder into the outer cylinder.

In view of the above, the present disclosure provides a roller device in which a thermoelectric converting element and heatsinks can be smoothly disposed inside a cylindrical body by a simple work, and provides a printer using the roller.

Hereinafter, the exemplary embodiment of the present disclosure will be described with reference to the drawings. For the sake of convenience, X-axis, Y-axis, and Z-axis which are perpendicular to each other are added to the drawings. Note that in the following description, the term “ink” in the terms “ink roller” has the same meaning as “ink”.

FIG. 1is a diagram schematically illustrating a configuration of printer1. Here, a configuration example of printer1configured to perform printing on one side of printing paper P1is shown.

As shown inFIG. 1, printer1includes paper feed unit2, four printing units3, and accumulation unit4. Paper feed unit2stores printing paper P1of a predetermined size, which is a print medium, and feeds stored printing paper P1in sequence to printing unit3on the most Y-axis negative side. Printing paper P1sent out from paper feed unit2is transferred in sequence to four printing units3by a conveying mechanism of each printing unit3.

Each of four printing units3prints a pattern image in a predetermined color on printing paper P1sent out from paper feed unit2. For example, each of four printing units3prints a pattern image in each of yellow, cyan, magenta, and black on printing paper P1.

Each of three printing units3on the Y-axis negative side feeds printing paper P1having been printed to adjacent printing unit3in a Y-axis positive direction by the conveying mechanism. Printing unit3on the most Y-axis positive side sends out printing paper P1after printing to accumulation unit4by the conveying mechanism. Accumulation unit4conveys sent-out printing paper P1to an accumulation part in sequence. In this manner, printing paper P1having been printed in all the colors is accumulated in accumulation unit4.

Each of four printing units3has a similar configuration to each other. Each printing unit3includes ink storage3afor storing ink of a corresponding color. Each printing unit3includes four ink rollers10, plate cylinder21, blanket22, and impression cylinder23. Ink rollers10, plate cylinder21, blanket22, and impression cylinder23each have a columnar shape, and rotate about a rotation axis parallel to an X-axis in a direction parallel to a Y-Z plane.

Four ink rollers10guide ink from ink storage3ato plate cylinder21while being in rotational contact with the ink. In this manner, the ink guided to plate cylinder21is transferred to an outer circumferential surface of plate cylinder21in a predetermined drawing pattern. The ink transferred to the outer circumferential surface of plate cylinder21is transferred to blanket22at a contact position between plate cylinder21and blanket22. The ink thus transferred to blanket22is printed on printing paper P1fed between blanket22and impression cylinder23.

FIG. 2Ais a side view schematically illustrating a configuration of printing unit3near plate cylinder21.FIG. 2Bis a diagram schematically illustrating a printing method of printing unit3.

As shown inFIG. 2A, printing unit3further includes water roller24at a position close to plate cylinder21. Water roller24applies water32along the outer circumferential surface of the plate cylinder21. In this case, on the outer circumferential surface of plate cylinder21, there is previously mounted a plate for image formation. The plate is so configured that water is attached to a non-image-forming region. Therefore, the water applied to the outer circumferential surface of plate cylinder21by water roller24remains only in the non-image-forming region and does not remain in the image-forming region. Therefore, ink31guided to the outer circumferential surface of plate cylinder21from ink roller10is adhered only to the image-forming region, in which no water remains, of the outer circumferential surface of plate cylinder21.

FIG. 2Bshows a state where ink31and water32are adhered to the outer circumferential surface of plate cylinder21. Ink31thus transferred to the outer circumferential surface of plate cylinder21is transferred to blanket22as described above, and is then transferred to printing paper P1. In this manner, a pattern image corresponding to the plate mounted on the outer circumferential surface of plate cylinder21is printed on printing paper P1.

FIG. 3Ais a diagram illustrating a configuration of ink roller10.

Ink roller10includes roller main body10a, and support members10b,10c. Roller main body10ais constituted by a columnar structure body. An outer circumferential surface of roller main body10acomes into contact with the ink. Support members10b,10care cylindrical members, and respectively have holes10d,10epenetrating through in an X-axis direction. Support members10b,10chave a shape symmetric with respect to a central axis parallel to the X-axis. Support members10b,10care each made of a metallic material. Support members10b,10care mounted on roller main body10ain such a manner that circular flanges10fand10gcover both ends of roller main body10a.

FIG. 3Bis a diagram illustrating how ink roller10is mounted on frames41,42of printer1. For the sake of convenience, inFIG. 3B, junctions between frames41,42and support members10b,10care shown transparently in a Y-axis direction.

Ink roller10is supported by frames41,42with support members10b,10cbeing fit into bearings41aand42a. Ink roller10is movable in the X-axis direction and is rotatable about an axis parallel to the X-axis, respectively. Ink roller10is driven in the X-axis direction by a drive mechanism (not shown), and is rotated about the axis parallel to the X-axis. In this manner, damping water (diluting liquid) is supplied to the outer circumferential surface of ink roller10while ink roller10is being driven, so that the damping water is mixed with the ink being in contact with ink roller10, and, as a result, the ink is adjusted to be in an appropriate emulsified state, which is in an appropriate viscosity.

Note that such an operation of ink roller10generates frictional heat between ink roller10and the ink, whereby a temperature of ink roller10is increased. On the other hand, because the ink used for printing is mainly ultraviolet curable ink, the ink has high viscosity and requires strict temperature control. In particular, when inexpensive ink, which requires high intensity ultraviolet irradiation for curing, is used, the viscosity of the ink is high, and frictional heat generated between ink roller10and the ink is accordingly high. This requires a configuration to efficiently remove heat generated in ink roller10and to thus adjust the temperature of ink roller10to a predetermined temperature accurately.

In view of the above, in the present exemplary embodiment, ink roller10includes a plurality of thermoelectric converters arranged on an inner peripheral surface of roller main body10a. Thermoelectric converters are supplied with electric power through a slip ring (not shown). On heat dissipation surfaces of the thermoelectric converters, a heatsink is disposed. The heat generated on the outer circumferential surface of roller main body10ais transferred to the heatsink by the thermoelectric converters. A ventilation device (not shown) causes cooling wind to flow inside roller main body10athrough support members10b,10c. This removes the heat transferred to the heatsink by the thermoelectric converters.

Hereinafter, a structure of roller main body10awill be described with reference toFIGS. 4 to 10B.

FIG. 4is a perspective view illustrating the configuration of roller main body10awhen viewed from an entrance side of the cooling wind.FIG. 5is a perspective view illustrating the configuration of roller main body10a, in which cylindrical body100is omitted.

As shown inFIGS. 4 and 5, roller main body10aincludes cylindrical body100, two heatsinks200, four heat pipes300, four press-fitting members400, and a plurality of thermoelectric converters500.

Cylindrical body100has a cylindrical shape and is made of a metallic material such as copper or aluminum, which is excellent in thermal conductivity. Alternatively, iron is used for cylindrical body100in some cases in consideration of strength of cylindrical body100. In cylindrical body100, circular through hole101passing through in the X-axis direction is formed. At an end part in an X-axis negative side and an end part in an X-axis positive side, through hole101has a diameter slightly larger than a diameter at the other part of through hole101. Cylindrical body100has six bolt holes102in each of an end face on the X-axis negative side and an end face of the X-axis positive side. Bolt holes102are used for fixing support members10b,10cshown inFIG. 3A.

Heatsink200has a semi-columnar shape and is configured of a material such as copper or aluminum, which has an excellent thermal conductive property. Heatsink200has a length slightly shorter than a length of cylindrical body100. Both of two heatsinks200have the same shape with each other. Two heatsinks200configure an approximately columnar structure body by stacking in up-down direction. An outer diameter of this columnar structure body is smaller than an inner diameter of cylindrical body100.

FIG. 6is an exploded perspective view illustrating heatsink200on an upper side (Z-axis positive side) as well as thermoelectric converters500and heat pipes300that are mounted on this heatsink200. Note that a configuration of heatsink200on a lower side (Z-axis negative side) and thermoelectric converters500and heat pipes300mounted on this heatsink200is similar to the configuration shown inFIG. 6.

In heatsink200, top surface201, two holes202, groove203, a plurality of fins204, and two recesses205are integrally formed.

Top surface201is a circular arc-shaped curved surface. On top surface201, ten thermoelectric converters500are provided at approximately equal intervals. As will be described later, each thermoelectric converter500can be curved in a direction parallel to the Y-Z plane. Thermoelectric converters500are disposed on top surface201with a bonding means such as adhesive or heat dissipation grease in a state where thermoelectric converters500are curved in a shape along top surface201.

Two holes202have a circular cross-sectional shape, extend in the X-axis direction, and penetrate through heatsink200. Each hole202has a diameter slightly larger than a diameter of heat pipe300. Two holes202are provided at positions symmetric in the Y-axis direction. In each of two holes202, heat pipe300is inserted and attached. Heat pipe300is inserted in hole202to extend from the vicinity of one end part of heatsink200in a longitudinal direction to the vicinity of the other end part. Specifically, heat pipe300extends over mounting positions of all ten thermoelectric converters500disposed on top surface201of heatsink200.

Heat pipe300is provided in order to make temperature of top surface201of heatsink200uniform in the X-axis direction. In heat pipe300, heat is transferred from a high temperature part to a low temperature part by an operating fluid circulating in heat pipe300while repeating vaporization and condensation. This approximately makes uniform the temperature of top surface201of heatsink200. Since the temperature of top surface201is made uniform, the temperature of the heat dissipation surfaces of ten thermoelectric converters500is made to be approximately the same temperature, and cooling performances of all thermoelectric converter500can be maintained high.

Groove203is provided to regulate a position of press-fitting member400. Groove203has an approximately V-shaped cross-sectional shape and extends in the X-axis direction from the end face of heatsink200on the X-axis negative side to the end face of the X-axis positive side. Groove203has two planar-shaped wall surfaces203a,203bfor receiving press-fitting member400. When a virtual plane parallel to an X-Z plane is set at the deepest position of groove203, two wall surfaces203a,203bare inclined in an opposite direction to each other at almost the same angle with respect to this virtual plane. A bottom part of groove203is slightly rounded.

By a plurality of notches being approximately radially formed from a central position of a bottom surface of heatsink200in the Y-axis direction, a plurality of fins204are formed. Each fin204extends in the X-axis direction from the end face, on the X-axis negative side, of heatsink200to the end face on the X-axis positive side. The cooling wind flowing in the X-axis direction through gaps between these fins204removes the heat transferred from cylindrical body100to heatsink200.

Recesses205are provided to draw out lead wires for supplying electric power to thermoelectric converters500. Each recess205has a shape in which an outer circumferential surface of heatsink200is cut out in a circular arc shape. Each recess205extends in the X-axis direction from the end face, on the X-axis negative side, of heatsink200to the end face on the X-axis positive side. The lead wires drawn out from each thermoelectric converter500are drawn out to outside while being housed in recess205.

FIG. 7is a partially exploded perspective view illustrating: a structure body configured with heatsink200on the upper side (Z-axis positive side), thermoelectric converters500, and heat pipes300; and press-fitting members400.

Press-fitting members400are each made up of a rod-shaped member having a circular cross-section, and are each configured with a material such as stainless steel, which has high rigidity. In the present exemplary embodiment, four press-fitting members400are used. A length of each press-fitting member400is half a length of heatsink200. Four press-fitting members400all have the same shape.

End part401of press-fitting member400in an insertion direction has a conical-shape (a tapered shape toward a tip), whose width becomes narrow toward the tip. Two press-fitting members400are disposed in one groove203of heatsink200, being arranged in line in the X-axis direction. Therefore, two press-fitting members400disposed in line in the X-axis direction are disposed to cover approximately an entire range of heatsink200in a longitudinal direction. In other words, press-fitting members400are disposed in substantially the entire range of heatsink200in the longitudinal direction.

Next, a structure of thermoelectric converter500will be described with reference toFIGS. 8A to 9B. Note that for the sake of convenience, x-axis, y-axis, and z-axis which are perpendicular to each other are newly added toFIGS. 8A to 9B. An x-axis direction, a y-axis direction, and a z-axis direction are respectively correspond to a width direction, a length direction, and a thickness direction of thermoelectric converter500.

FIG. 8Ais a perspective view illustrating a configuration of thermoelectric converter500, andFIG. 8Bis a perspective view illustrating the configuration of thermoelectric converter500before second substrate550is attached.FIG. 9Ais a perspective view illustrating a partially enlarged view of an electrode group arranged on first substrate510, andFIG. 9Bis a perspective view illustrating how thermoelectric converting elements520are connected when thermoelectric converting elements520are arranged on the electrode group ofFIG. 9A.

Note that inFIG. 9B, each of P-type thermoelectric converting elements520is appended with the character “P”, and each of N-type thermoelectric converting elements520is appended with the character “N”. Further, inFIG. 9B, the broken line arrows each represent an electrical connection route. For the sake of convenience, inFIG. 9B, support members530are not shown, and electrodes551disposed on a lower surface of second substrate550are shown.

First substrate510and second substrate550have, in a plan view, a rectangular outline whose corners are rounded. First substrate510and second substrate550are made of a material that has an excellent thermal conductive property and are deformable. For example, a thin copper plate can be used as first substrate510and second substrate550. Other than this material, first substrate510and second substrate550may be formed of, for example, aluminum, silicone resin, or epoxy resin.

As shown inFIGS. 8B and 9A, on an upper surface (a surface on the z-axis positive side) of first substrate510, there is provided an electrode group constituted by electrodes511and bridging electrodes512,513. On edges of the upper surface of first substrate510, there are provided first patterns514to517and second patterns518,519. Electrodes511, bridging electrodes512,513, first patterns514to517, and second patterns518,519are formed of, for example, copper or aluminum. In a case where first substrate510is configured of a conductive material, a flexible insulating layer is provided between first substrate510and each of electrodes511, bridging electrodes512,513, first patterns514to517, and second patterns518,519.

To upper surfaces of electrodes511and bridging electrodes512,513, there are bonded lower surfaces of thermoelectric converting elements520with solder. To upper surfaces of second patterns518,519, there are bonded lower surfaces of support members530with solder. Further, to second patterns518,519, there are connected lead wires541,542with solder. On first patterns514to517, none of thermoelectric converting elements520and support members530is provided.

Electrodes511are arranged along a plurality of columns extending in a y-axis direction. Bridging electrodes512,513are respectively disposed on an end on a y-axis negative side and on an end on a y-axis positive side so as to bridge two columns.

Bridging electrode512includes: two areas512a,512b; and area512cconnecting these areas512a,512b. Two areas512a,512bof bridging electrode512have the same thickness as electrodes511. Area512cof bridging electrode512has a smaller thickness and larger surface area than electrode511. Areas512a,512b,512care integrally formed. Further, bridging electrode512has notches512d,512einside bridging electrode512, and notches512d,512eare each recessed in a circular arc shape toward inside and parallel to the y-axis direction. Notches512d,512eare formed on a separator line that separates adjacent columns, and are formed to be recessed along the separator line.

As shown inFIG. 8B, on edge parts on the y-axis positive side and on the y-axis negative side of the upper surface of first substrate510, first patterns514to517are formed to extend in the x-axis direction. Further, on edge parts on the x-axis positive side and on the x-axis negative side of the upper surface of first substrate510, second patterns518,519are formed to extend in the y-axis direction. Second pattern518on the right side is integrally connected to bridging electrode513on the right most end, and second pattern519on the left side is integrally connected to bridging electrode513on the most left end. On the upper surface of first substrate510, the electrode group and a group of patterns are disposed to be symmetric in the x-axis direction.

A thickness of first patterns515to517is slightly thinner than a thickness of areas512c. First patterns515to517are for giving tension to first substrate510when first substrate510is bent in a direction parallel to an x-z plane. This configuration enables first substrate510to be smoothly bent in the direction parallel to the x-z plane.

Note that the thickness of first patterns515to517may be another thickness as long as first patterns515to517can apply a desired tension to first substrate510. Further, the first patterns formed on the edge, of substrate510, on the Y-axis negative side do not have to be separated into three parts in the x-axis direction and may be separated into another number of parts, or may not be separated like first pattern514formed on an end of first substrate510on the y-axis positive side.

A thickness of second pattern519is approximately the same as the thickness of areas512a,512band electrodes511. A width, in the x-axis direction, of second pattern519is approximately the same as a width, in the x-axis direction, of areas512a,512band electrodes511. Other than a function to connect lead wire542and thermoelectric converting elements520as described above, second pattern519has a function as a reinforcing function to make first substrate510less bendable in a direction parallel to a y-z plane.

Seven bridging electrodes513as central electrodes shown inFIG. 8Balso have a similar configuration to bridging electrodes512. These seven bridging electrodes513have a structure that is line-symmetric to bridging electrode512in the y-axis direction. Bridging electrode513on the leftmost side is integrally connected to second pattern519, and bridging electrode513on the rightmost side is integrally connected to second pattern518.

First pattern514on the y-axis positive side has the same thickness and width as first patterns515to517on the y-axis negative side. First pattern514on the y-axis positive side is, similarly to first patterns515to517on the y-axis negative side, for giving tension to first substrate510when first substrate510is bent in the direction parallel to the x-z plane. First pattern514on the y-axis positive side may be made of a plurality of parts separated in the x-axis direction. Further, second pattern518on the x-axis positive side has the same thickness and width as second patterns519on the x-axis negative side.

As shown inFIGS. 8B and 9B, on each electrode511, two thermoelectric converting elements520, which are each P type and N type, are disposed to be arranged in line in the y-axis direction. Further, on each of bridging electrodes512,513, two thermoelectric converting elements520, which are each P type and N-type, are disposed to be arranged in line in the X-axis direction. On each of second patterns518,519, there are disposed four support members530.

Thermoelectric converting elements520have an approximately cubic shape. Thermoelectric converting elements520are each made up of an element such as a Peltier element that controls heat by electric power. Support members530have a similar shape to thermoelectric converting elements520. Support members530have a height that is the same as a height of thermoelectric converting elements520. Support members530are each made of a highly rigid material. Support members530are each made of such a material that the patterns of first substrate510and second substrate550(seeFIG. 6) can be soldered to an upper surface and a lower surface of each support member530. For example, support members530can be configured of a zinc alloy. Alternatively, each support member530may be configured by plating a surface of a structure body made of metal, resin material, or other materials.

P-type thermoelectric converting elements520and N-type thermoelectric converting elements520that are disposed in line in the y-axis direction are series-connected by electrodes511and electrodes551. Electrodes551are disposed on the lower surface of second substrate550. Further, on the most y-axis negative side, P-type thermoelectric converting elements520and N-type thermoelectric converting elements520that are disposed in line in the x-axis direction are series-connected by bridging electrodes512. Similarly, on the most y-axis positive side, P-type thermoelectric converting elements520and N-type thermoelectric converting elements520that are disposed in line in the x-axis direction are series-connected by bridging electrodes513(seeFIG. 8B) on first substrate510. In this manner, all thermoelectric converting elements520on first substrate510are series-connected between lead wires541,542.

Thermoelectric converter500having the above configuration is flexible in the direction parallel to the x-z plane. Specifically, first substrate510is flexible; and on first substrate510there are gaps G1generated between the columns of electrodes511disposed in line in the y-axis direction as shown inFIG. 9A. Further, since each of bridging electrodes512,513disposed on first substrate510has a small thickness and is provided with notches512d,512e, first substrate510can be easily bent at positions of the straight lines extending along gaps G1. Therefore, first substrate510can be bent in the direction parallel to the x-z plane, at the positions of the straight lines extending along gaps G1.

Further, second substrate550is also flexible; and on second substrate550there are gaps G2generated between electrodes511disposed in line in the y-axis direction as shown inFIG. 9B. Therefore, second substrate550can also be bent in the direction parallel to the x-z plane, at the positions of the straight lines extending along gaps G2. As described above, first substrate510and second substrate550can be bent in the direction parallel to the x-z plane, at the positions of the straight lines extending along gaps G1and G2, respectively. Therefore, thermoelectric converter500shown inFIG. 8Ais flexible in the direction parallel to the x-z plane.

In the structure body shown inFIG. 5, thermoelectric converters500are provided (temporarily fixed) on top surface201of heatsink200with adhesive or the like in such a manner that thermoelectric converters500are bent along top surface201of heatsink200. Lead wires541,542are drawn out to outside while being housed in recesses205formed in the side surface of heatsink200.

Next, an assembly process of roller main body10awill be described.

First, as shown inFIG. 6, heat pipe300is attached to each of two holes202of heatsink200, and ten thermoelectric converters500are disposed on top surface201of heatsink200. By this process, the structure body shown in the upper part ofFIG. 7is formed. Also on another heatsink200, sheet pipes300and thermoelectric converters500are disposed to configure the other structure body. The thus-configured two structure bodies are stacked on each other and inserted inside cylindrical body100. Further, two press-fitting members400are inserted into each groove203of heatsink200. In this manner, assembly of roller main body10ais completed.

FIG. 10Ais a side view illustrating roller main body10abefore press-fitting members400are inserted. Specifically,FIG. 10Ashows a state where two structure bodies S10each constituted by heatsink200, heat pipes300, and thermoelectric converters500are stacked on each other and inserted inside cylindrical body100.

As shown inFIG. 10A, when two structure bodies S10are stacked, a diameter of two structure bodies S10, which is defined from an outer circumferential surface of upper thermoelectric converters500to an outer circumferential surface of lower thermoelectric converters500, is slightly smaller than the inner diameter of cylindrical body100, which is a diameter of through hole101. Hence, there is gap G11, which is shown by the broken line inFIG. 10A, between upper thermoelectric converters500and an inner peripheral surface of cylindrical body100. Due to this gap G11, two structure bodies S10can be smoothly inserted into through hole101.

After two structure bodies S10, which are stacked on each other, are positioned at a predetermined position in through hole101in this manner, press-fitting members400are inserted into grooves203of heatsinks200. In this case, for example, after two press-fitting members400are inserted into one of two grooves203, two other press-fitting members400are inserted into another groove203. Note that, two press-fitting members400may be inserted into each of both two grooves203simultaneously.

By inserting press-fitting members400into two grooves203, a distance between two heatsinks200becomes wide. Accordingly, heatsink200on the upper side is displaced upward (positive direction in the Z-axis), so that upper thermoelectric converters500are pressed against the inner peripheral surface of cylindrical body100. Further, reaction force applied from the inner peripheral surface of cylindrical body100to heatsink200on the upper side presses lower thermoelectric converters500against the inner peripheral surface of cylindrical body100. In this manner, upper and lower thermoelectric converters500are each held between the inner peripheral surface of cylindrical body100and heatsinks200while being in close contact with the inner peripheral surface of cylindrical body100.

In this case, the diameter of press-fitting member400is set so as to generate enough pressure to bring each of upper and lower thermoelectric converters500into close contact with the inner peripheral surface of cylindrical body100in the state shown inFIG. 10B.

Note that it is preferable that press-fitting members400be inserted into groove203simultaneously from both sides of heatsinks200in the longitudinal direction.

FIG. 11Ais a transparent view schematically illustrating a state of the inside of cylindrical body100when press-fitting member400is inserted from only one side of heatsinks200.

As shown inFIG. 11A, if press-fitting member400is inserted from only one side of heatsinks200, an end part on an insertion side of heatsink200on the upper side is lifted up, and this heatsink200is inclined. Accordingly, a large load is locally applied to thermoelectric converters500disposed on the end part on the insertion side of heatsink200. As a result, damage can be caused on such thermoelectric converters500. The broken line circle inFIG. 11Arepresents the part to which the large load is locally applied.

FIGS. 11B and 11Care transparent views each schematically illustrating the state of the inside of cylindrical body100when press-fitting members400are simultaneously inserted from both sides of heatsinks200.

In a case where press-fitting members400are inserted simultaneously from both sides of heatsinks200as shown inFIG. 11B, heatsink200on the upper side is evenly lifted up without being inclined. Therefore, a large load is not locally applied to any of thermoelectric converters500, and a load is appropriately applied to all of thermoelectric converters500approximately evenly. As a result, damage cannot be caused on any of thermoelectric converters500.

When press-fitting members400are completely inserted as shown inFIG. 11C, press-fitting members400are disposed in substantially the entire range of heatsinks200in the longitudinal direction. Therefore, in the entire range of the longitudinal direction, upper and lower heatsinks200are evenly pressed in up-down direction. Therefore, all of thermoelectric converters500disposed on each of upper and lower heatsinks200are pressed against the inner peripheral surface of cylindrical body100by an approximately uniform load. Therefore, all thermoelectric converters500are appropriately in close contact with the inner peripheral surface of cylindrical body100. In this case, the expression “substantially the entire range” means a range that can exhibit an effect of evenly pressing upper and lower heatsinks200in the entire range of the longitudinal direction by inserting press-fitting members400.

FIG. 12Ais a diagram schematically illustrating how an end edge of groove203is deformed and widened due to the insertion of press-fitting member400.

When press-fitting member400is inserted into groove203as shown inFIG. 12A, the end edge on the insertion side of groove203is deformed and widened by a large load applied at the time of starting insertion, and recesses A1, A2are created on the end edge on the insertion side of groove203. Similarly, also in a surface, of heatsink200, facing groove203there is recess A3created, due to a load, at a position on the end edge on the insertion side. Therefore, in the case where press-fitting members400are inserted into groove203from both side of heatsinks200as shown inFIGS. 11B and 11C, recesses A1, A2due to the deformation at the time of insertion are created in the end edges on the both sides of groove203in the longitudinal direction, and, in addition, recesses A3are created at positions approximately facing these recesses A1, A2.

FIG. 12Bis a diagram schematically illustrating a state of the end edge, of groove203, on a side opposite to an insertion side when press-fitting member400is inserted from only one side of heatsinks200.

In the case where press-fitting member400is inserted into groove203from only one side of heatsinks200, a load applied to the end edge, of groove203, on the side opposite to the insertion side is not as large as the load applied to the end edge on the insertion side. Therefore, on the end edge, of groove203, on the side opposite to the insertion side, two wall surfaces203a,203bare only slightly deformed due to the insertion of press-fitting member400; and the end edge, of groove203, on the side opposite to the insertion side is not so largely deformed to create recesses as the other part of groove203.

As described above, depending on whether press-fitting members400are inserted from the both sides of heatsinks200or inserted from only one side, the end edges on the both sides of groove203are widened differently. In the case where press-fitting members400are inserted into groove203from the both sides of heatsinks200as shown inFIGS. 11B and 11C, the both end edges of groove203are widened compared with the other part of groove203because of deformation due to insertion of press-fitting members400, so that recesses A1, A2are created in the both end edges of groove203. Therefore, from how the end edges on the sides of groove203are widened, it can be seen whether press-fitting members400are inserted from the both sides of heatsinks200or inserted from only one side.

<Advantageous Effects of Exemplary Embodiment>

The present exemplary embodiment provides the following effects.

As already described with reference toFIGS. 10A and 10B, by a really simple work, for example, by inserting press-fitting member400between upper and lower heatsinks200, heatsinks200and thermoelectric converters500can be smoothly disposed in cylindrical body100.

As shown inFIG. 6, in each of upper and lower heatsinks200, there is provided groove203for regulating a position of press-fitting member400. Therefore, it is possible to smoothly insert press-fitting members400at predetermined positions without any positional displacement.

As shown inFIG. 7, each press-fitting member400is constituted by a rod-shaped member having a circular cross-section, and groove203receives press-fitting member400by two planar-shaped wall surfaces203a,203bthat are inclined in an opposite direction to each other. Therefore, an area on which press-fitting member400is in contact with groove203at the time of insertion can be small, so that friction at the time of insertion can be made small. Therefore, press-fitting member400can be smoothly inserted into groove203.

As shown inFIGS. 5, 10A, and 10B, groove203for regulating the position of press-fitting member400is provided in one of upper and lower heatsinks200, and the flat surface is provided on the area, of the other of upper and lower heatsinks200, facing groove203. With this arrangement, when press-fitting member400is inserted, press-fitting member400and the flat surface come in slide-contact with each other. Hence, the position of heatsink200in a direction parallel to a boundary plane dividing between upper and lower heatsinks200can be adjusted. This can improve contactivity between the inner peripheral surface of cylindrical body100and thermoelectric converters500, which are disposed between the inner peripheral surface of cylindrical body100and heatsinks200.

As shown inFIG. 7, end part401of each press-fitting member400in the insertion direction has a conical-shape that is a tapered shape toward a tip. Therefore, end part401of press-fitting member400can be smoothly inserted into groove203at the time of insertion. Hence, as insertion of press-fitting member400proceeds, groove203can be smoothly displaced along the conical-shape of end part401. Therefore, work at the time of insertion can be more easily performed.

As already described with reference toFIGS. 11B and 11C, by approximately simultaneously inserting press-fitting members400from the both sides of heatsinks200in the longitudinal direction, it is possible to prevent or reduce inclination of heatsink200at the time of insertion. Hence, it is possible to prevent or reduce damage to thermoelectric converters500caused by a large load applied to thermoelectric converters500disposed on heatsink200. In this case, as already described with reference toFIGS. 12A and 12B, the fact that press-fitting members400are approximately simultaneously inserted from the both sides of heatsinks200in the longitudinal direction can be confirmed by recesses A1, A2being created on each of the both end edges of groove203in the longitudinal direction. Here, recesses A1, A2are created by deformation of the both end edges of groove203in the longitudinal direction being widened more than the other part of groove203, which is caused by insertion of press-fitting members400.

As shown inFIG. 7, two press-fitting members400aligned in the X-axis direction are disposed over substantially an entire range of heatsink200in the longitudinal direction. Therefore, as already described with reference toFIG. 11C, upper and lower heatsinks200are pressed apart in up-down direction evenly in the entire range in the longitudinal direction. Hence, all of thermoelectric converters500disposed on each of upper and lower heatsink200are pressed against the inner peripheral surface of cylindrical body100by an approximately uniform load. Therefore, all thermoelectric converters500can be appropriately in close contact with the inner peripheral surface of cylindrical body100.

Note that, not limited to the case where two press-fitting members400are disposed for one groove203as in the above exemplary embodiment, the above effect can also exhibit in a case where one press-fitting member having the same length as the overall length of groove203is disposed for one groove203, as well as in a case where three or more press-fitting members are disposed in one groove203so as to approximately cover the overall length of one groove203. The present disclosure can include these forms.

In roller main body10aaccording to the present exemplary embodiment, heatsinks200and thermoelectric converters500are fixed on cylindrical body100from inside of cylindrical body100by using press-fitting members400. Hence, the outer circumferential surface of cylindrical body100can be a uniform and smooth curved surface over the entire circumference as shown inFIG. 4. Accordingly, ink can be uniformly distributed over the outer circumferential surface of roller main body10a. Therefore, damping water and ink can be well kneaded, and a uniform ink film can be formed on plate cylinder21.

Modified Example

The exemplary embodiment of the present disclosure can be variously modified.

For example, elastic bodies601may be disposed between press-fitting members400and heatsinks200as shown inFIG. 13A, or elastic bodies602may be disposed between thermoelectric converters500and the inner peripheral surface of cylindrical body100as shown inFIG. 13B.

By disposing elastic bodies601,602in this manner, it is possible to prevent or reduce the occurrence of pressing thermoelectric converters500against the inner peripheral surface of cylindrical body100by an excessive load even when there is a variation in the inner diameter of cylindrical body100, the diameters of press-fitting members400, or the like. Hence, thermoelectric converters500can be in close contact with the inner peripheral surface of cylindrical body100by an appropriate load.

In a first modified example ofFIG. 13A, each of elastic bodies601is a plate-shaped member made of rubber, sponge, or the like, and has approximately the same length as groove203. For example, each of elastic bodies601is fixed on a surface, of heatsink200, facing corresponding groove203with an adhesive or the like. Further, in a second modified example ofFIG. 13B, each of elastic bodies602is constituted by a heat dissipation sheet, a heat dissipation grill, or the like which are excellent in thermal conductivity, and are disposed over an approximately overall length of press-fitting member400. Elastic bodies601,602may be each divided in the X-axis direction.

Note that although elastic body601is disposed at each of the two positions facing grooves203in the first modified example ofFIG. 13A, elastic body601may be disposed only at any one of the positions. Further, although each of elastic bodies602is disposed between thermoelectric converters500and the inner peripheral surface of cylindrical body100in the second modified example ofFIG. 13B, each of elastic bodies602may be disposed between thermoelectric converters500and top surface201of heatsink200.

Alternatively, as shown inFIG. 14A, press-fitting member400inserted in groove203on the left side (on the Y-axis negative side) may be omitted, and projecting ridge211may be formed on an upper surface of lower heatsink200so as to be engaged in this groove203. In this case, projecting ridge211extends in the X-axis direction along the approximately overall length of groove203. An upper surface of projecting ridge211preferably has a circular arc shape when viewed in the X-axis direction such that a contact area between the upper surface and groove203is reduced.

In the third modified example ofFIG. 14A, upper and lower structure bodies S10are inserted into through hole101of cylindrical body100while being stacked such that projecting ridge211is engaged in groove203. After that, press-fitting member400is inserted into groove203to configure roller main body10aofFIG. 14A. Also in this case, as shown inFIGS. 11B and 11C, it is preferable to insert press-fitting member400simultaneously from the both sides of heatsinks200.

In the third modified example ofFIG. 14A, projecting ridge211is configured to be engaged in groove203. Meanwhile, projecting ridge211and groove203may be replaced by a hinge, and upper and lower heatsinks200may be rotatably connected to each other by the hinge. In this case, it is not necessary to accurately align and stack two structure bodies S10when two structure bodies S10are inserted into through hole101of cylindrical body100. Hence, a work of assembling roller main body10acan be simpler.

Further, as shown inFIG. 14B, the shape of groove203when viewed in the X-axis direction may be a circular arc shape. Also in this modified example, since the insertion position of press-fitting member400is regulated by groove203, press-fitting member400can be smoothly inserted at a predetermined position without any positional displacement. In addition to this shape, the shape of groove203may be another shape such as an elliptic arc shape.

Note that, in a fourth modified example ofFIG. 14B, since a contact area between press-fitting member400and groove203is larger than in the case where groove203has a V shape having two planar-shaped wall surfaces203a,203bas shown in the above exemplary embodiment, friction between press-fitting member400and groove203is accordingly greater when press-fitting member400is inserted. Therefore, in the present modified example, it is difficult to insert press-fitting member400into groove203compared with the above exemplary embodiment. Accordingly, in order to perform insertion work more easily, groove203preferably has a V shape having two planar-shaped wall surfaces203a,203bas in the above exemplary embodiment.

Alternatively, as shown inFIG. 14C, groove203may be formed in one of upper and lower heatsinks200, and guide groove212may be formed in an area, of another heatsink200, facing the end edge on the insertion side of groove203such that guide groove212becomes shallower toward an insertion direction of press-fitting member400. In this case, end part401of press-fitting member400can be inserted into groove203more smoothly. In a fifth modified example ofFIG. 14C, the shape of guide groove212when viewed in the X-axis direction is a V shape. Meanwhile, the shape of guide groove212is not limited to the V shape and may be another shape such as a circular arc shape.

Note that guide groove212does not have to be provided in both of the areas each facing corresponding groove203and may be provided in only one of the areas. For example, in a case where, after press-fitting member400is inserted into one of two grooves203, press-fitting member400is inserted into another groove203, the gap between upper and lower heatsinks200can be widened at the position of the one of grooves203, and press-fitting member400can be therefore inserted into this one groove203relatively easily. Therefore, in this case, guide groove212does not have to be particularly provided in the area facing this one groove203, and guide groove212only has to be provided only in the area facing another groove203.

Note that, in the above exemplary embodiment, groove203is formed at the insertion position of press-fitting member400in one heatsink200, and another heatsink200has a flat surface with no groove provided. Meanwhile, groove203may be formed at a press-fitting position of press-fitting member400in each of the both heatsinks200so that press-fitting member400is held in each of two grooves203.

Further, as shown inFIGS. 15A and 15B, plate-shaped press-fitting members411,412may be disposed between two heatsinks200. In a sixth modified example ofFIG. 15A, a shape of press-fitting member411when viewed in the Y-axis direction is a trapezoid. In a seventh modified example ofFIG. 15B, a shape of press-fitting member412when viewed in the Y-axis direction is a rectangle that has longer side along the Y-axis direction. In the sixth and seventh modified examples ofFIGS. 15A and 15B, groove203is provided on neither upper nor lower heatsinks200.

In the sixth and seventh modified examples ofFIGS. 15A and 15B, an end part, of each of press-fitting members411,412, on a front side in an insertion direction preferably have a shape whose width in the Z-axis direction become narrow toward a tip. This shape enables press-fitting members411,412to be smoothly inserted into a gap between upper and lower heatsinks200. Further, press-fitting members411,412are preferably inserted between upper and lower heatsinks200from both sides in the longitudinal direction of heatsinks200, and press-fitting members411,412are preferably disposed in substantially in the entire range of heatsinks200in the longitudinal direction. Similar to the case ofFIGS. 11B and 11C, this configuration enables thermoelectric converter500to prevent from being damaged and enables all thermoelectric converters500to be appropriately in close contact with the inner peripheral surface of cylindrical body100.

In the above exemplary embodiment, two heatsinks200are disposed inside cylindrical body100. Meanwhile, a number of heatsinks200disposed inside cylindrical body100is not limited to two, and the number may be three or more. In this case, not all of top surfaces201of heatsinks200have to be disposed with thermoelectric converters500, but in order to improve cooling efficiency of ink roller10, all of top surfaces201of heatsinks200are preferably disposed with thermoelectric converters500. Further, press-fitting member400does not have to be inserted between all joint positions between adjacent two heatsinks200, and a press-fitting member does not have to be inserted at a predetermined joint position as long as all of thermoelectric converters500can be appropriately in close contact with the inner peripheral surface of cylindrical body100.

In the above exemplary embodiment, thermoelectric converters500can be deformable to be curved. Meanwhile, it is possible to use thermoelectric converters500that cannot be curved. In this case, for example, by using a first support member whose one surface is a flat surface and whose the other surface is a curved surface, and a second support member whose one surface is a curved surface and whose the other surface is a flat surface, thermoelectric converters500can be disposed on top surface201of heatsink200. Here, the curved surface of the first support member is curved along top surface201of heatsink200. And the curved surface of the second support member is curved along the inner peripheral surface of cylindrical body100. Specifically, first, a unit including thermoelectric converters500, the first support member, and the second support member is formed so that thermoelectric converters500are sandwiched between the flat surface of the first support member and the flat surface of the second support member. And then this unit is disposed on top surface201of heatsink200in such a manner that the curved surface of the first support member is in contact with top surface201of heatsink200. With this configuration, thermoelectric converters500are disposed on the top surface of heatsink200, being sandwiched between the first support member and the second support member. However, in this configuration, two support members are required to sandwich thermoelectric converters500. Therefore, for a simpler configuration and higher working efficiency, it is preferable that thermoelectric converters500can be curved as in the above exemplary embodiment.

In the above exemplary embodiment, two press-fitting members400are inserted in one groove203. Meanwhile, one or more than two press-fitting members400may be inserted in one groove203. When a plurality of press-fitting members400are inserted in one groove203, there may be a gap between adjacent press-fitting members400.

In addition, heat pipe300may be omitted, as appropriate. A number of ink rollers10disposed on printing unit3is not limited to four. Other than the configuration for printing on one side of printing paper P1, printer1may be configured to print on both sides. In this case, a number of installed printing units3is changed as appropriate. Note that the present disclosure can be applied not only to ink rollers but also to other roller devices that can control cooling temperatures or heating temperatures.

The exemplary embodiment of the present disclosure can be modified in various manners as appropriate within the scope of the technical idea recited in the claims.

REFERENCE MARKS IN THE DRAWINGS