HEAT TRANSFER PIPE, HEAT TREATMENT APPARATUS AND TREATMENT SYSTEM

Abstract

To provide a heat transfer tube and the like capable of improving heat transferring performance in a longitudinal direction in comparison with a case where a liquid transfer portion for transferring a working fluid is kept into contact with the whole area of the inner wall surface of the tube, when observed from a cross section orthogonal to the longitudinal direction of the tube.SOLUTION: A heat transfer tube 1 includes: a tube 10 closed at both end portions; a working fluid 12 sealed inside of the tube 10 to be vaporized and liquefied; and a liquid transfer portion existing in a longitudinal direction Ld of the inside of the tube 10 and transferring the liquefied working fluid 12 at least in the longitudinal direction Ld. The transfer portion has a first liquid transfer portion 15 kept into contact with at least a part of a range of an inner wall surface 10c of the tube 10, and a second liquid transfer portion 16 not kept into contact with the inner wall surface 10c of the tube 10 and the first liquid transfer portion 15, when observed from the cross section orthogonal to the longitudinal direction Ld of the tube 10.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] This invention relates to heat transfer Guidance The present invention relates to a tube, a heat treatment device and a treatment system. [Background technology]

[0002] Conventionally, heat transfer devices such as heat pipes Guidance As the tube, for example, those described in Patent Documents 1 and 2 below are known.

[0003] Patent Document 1 describes a heat pipe including a pipe body having a hollow portion with both ends sealed, in which a working fluid is contained and which performs heat exchange with the outside, and a wick that is installed in the hollow portion of the pipe body and provides a capillary force to return the working fluid condensed in the condenser to the evaporator, the wick being a heat pipe having a substantially cylindrical structure in which a number of wires are braided in a spiral shape.

[0004] Patent document 2 describes a heat pipe having a container, a working fluid sealed inside the container, and a wick provided on the inner surface of the container and made of sintered metal made by sintering metal powder, in which the wick occupies 65% to 90% of the heat absorption part of the container. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 11-337279 A (Claim 1, etc.) [Patent Document 2] JP 2017-83138 A (Claim 1, etc.) Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention provides a heat transfer tube, a heat treatment device, and a treatment system that, when viewed in a cross section perpendicular to the longitudinal direction of the tube, can improve the thermal conduction performance in the longitudinal direction compared to when a liquid transfer section that transfers a working fluid is in contact with the entire inner wall surface of the tube. [Means for solving the problem]

[0007] The heat transfer tube of the present invention (1) is Both ends are closed A circular cross section with an outer diameter of 3 mm or less Tubes and A working fluid that is sealed inside the tube and vaporizes and liquefies; a liquid transfer section that transfers the liquefied working liquid present along the longitudinal direction inside the pipe at least in the longitudinal direction; Equipped with When the liquid transfer portion is viewed in a cross section perpendicular to the longitudinal direction of the pipe, All over the country a first liquid transfer section that contacts the inner wall surface of the tube and the first liquid transfer section; and a second liquid transfer section that does not contact the inner wall surface of the tube and the first liquid transfer section. The first liquid transfer The part It is made of a mesh material of metal wires. And, The second liquid transfer section is composed only of a wire-shaped material in which metal wires are twisted together and bundled into a shape with no circular space in the entire cross section. It is something. In addition, the heat transfer tube of the present invention (2) is Both ends are closed A circular cross section with an outer diameter of 3 mm or less Tubes and A working fluid that is sealed inside the tube and vaporizes and liquefies; a liquid transfer section that transfers the liquefied working liquid present along the longitudinal direction inside the pipe at least in the longitudinal direction; Equipped with When the liquid transfer portion is viewed in a cross section perpendicular to the longitudinal direction of the pipe, Some a first liquid transfer section that contacts the inner wall surface of the tube and the first liquid transfer section; and a second liquid transfer section that does not contact the inner wall surface of the tube and the first liquid transfer section. the first liquid transfer section is made of a mesh-like material made of metal wires, The second liquid transfer section is a wire that is twisted together. The bundle is bound in a shape that has no circular space in the entire cross section. Linear material Only It is composed of。

[0008] Also, This invention ( 3 ) Heat treatment equipment teeth, A heat treatment section that exchanges heat with the workpiece passing through in contact with the workpiece, and a heat transfer tube that is installed across a portion of the heat treatment section that corresponds to a passing region through which the workpiece passes and a portion that corresponds to a non-passing region through which the workpiece does not pass, and the heat transfer tube is the heat transfer tube of the above invention (1) or (2). It is.

[0009] This invention (4 ) is the above invention ( 3 ) In the heat treatment apparatus, the first liquid transfer section in the heat conduction pipe is in contact with an area including a portion of the inner wall surface of the pipe that is to come into contact with a high-temperature section that is to absorb heat during heat exchange in the heat treatment section.

[0010] Furthermore, this invention ( 5 ) processing system, A heat treatment device having a heat treatment section which exchanges heat with a workpiece passing through the heat treatment device, and another treatment device which performs a process other than the heat exchange on the workpiece before or after the workpiece passes through the heat treatment device, and the heat treatment device is the same as the heat treatment device according to the above-mentioned invention ( 3 ) or ( 4 ) heat treatment device. Effect of the Invention

[0011] The above invention (1) and (2) According to the heat transfer tube, Even if the pipe diameter becomes smaller than 3 mm, When viewed in a cross section perpendicular to the longitudinal direction of the tube, the thermal conduction performance in the longitudinal direction can be improved compared to when the liquid transfer section that transfers the working fluid is only in contact with the entire inner wall surface of the tube. The above invention (1) and (2) According to the method, the first liquid transfer portion is not made of a mesh-like material made of metal wires. It is made up of materials In comparison with the above case, the transfer of the working fluid is faster, and the heat transfer performance in the longitudinal direction can be improved. The above invention (1) and (2) According to Second liquid transfer section Metal wire It is not composed only of linear materials that are twisted together and bundled together in a shape that has no circular space in the entire cross section. Compared to the case of The vapor liquefies faster, the thermal conductivity in the longitudinal direction can be improved. 。

[0012] The above invention ( 3 ) Heat treatment equipment According to When viewed in a cross section perpendicular to the longitudinal direction of the heat transfer tube in the heat treatment section, the heat transfer performance in the longitudinal direction can be improved and the temperature difference occurring in the heat treatment section can be suppressed compared to a case where a heat transfer tube is used in which the liquid transfer section is only in contact with the entire inner wall surface of the tube. .

[0013] The above invention (4 ), the working fluid evaporates faster and the temperature difference occurring in the heat treatment unit is further suppressed compared to when the first liquid transfer section in the heat transfer tube is not in contact with the area of ​​the inner wall surface of the tube that includes the part that comes into contact with the high-temperature part that is to absorb heat during heat exchange in the heat treatment unit.

[0014] The above invention ( 5 According to the processing system of , when viewed in a cross section perpendicular to the longitudinal direction of the heat transfer tube in the heat processing section of the heat treatment device, the heat transfer performance in the longitudinal direction can be improved compared to a case in which a heat transfer tube is used in which the liquid transfer section is only in contact with the entire inner wall surface of the tube, and the temperature difference occurring in the heat processing section of the heat treatment device can be suppressed. [Brief description of the drawings]

[0015] [Figure 1] FIG. 2A is a schematic cross-sectional view along the longitudinal direction of a heat transfer tube according to the first embodiment, and FIG. 2B is a schematic cross-sectional view along line II of the heat transfer tube of FIG. [Diagram 2] FIG. 1 is a schematic diagram showing the measurement device used in the evaluation test as viewed from three directions. [Diagram 3] FIG. 2A is a cross-sectional view showing a heat transfer tube of an embodiment used in an evaluation test, FIG. 2B is a cross-sectional view showing a heat transfer tube of a comparative example used in an evaluation test, and FIG. 2C is a graph showing the results of the evaluation test. [Figure 4] 4A is a schematic cross-sectional view along the longitudinal direction of a heat transfer tube according to a modified example of the first embodiment, and FIG. 4B is a schematic cross-sectional view along the line IV-IV of the heat transfer tube of FIG. [Diagram 5] FIG. 11 is a schematic diagram showing the inside of a processing system according to a second embodiment. [Figure 6]FIG. 11 is a schematic diagram showing the inside of a heat treatment apparatus according to a second embodiment. [Figure 7] 7 is a schematic diagram showing, in partial cross section, the heat treatment apparatus of FIG. 6 as viewed from another direction. FIG. [Figure 8] 7A is a schematic cross-sectional view showing a part of a heating unit applied to the heat treatment apparatus of FIG. 6, and FIG. 7B is an exploded view of the heating unit of FIG. [Figure 9] FIG. 9(A) is a schematic diagram showing a part of the heating unit in FIG. 8, and FIG. 9(B) is a schematic diagram showing a heat transfer pipe. [Figure 10] FIG. 9 is a schematic diagram showing a part of the heating unit of FIG. 8. [Figure 11] FIG. 2A is a graph showing the heating state in the longitudinal direction of each heating device of the present invention and a conventional example, and FIG. 2B is a graph showing the warm-up time in each heating device using the heat transfer tubes of the embodiment and the comparative example. [Figure 12] FIG. 13(A) is a schematic diagram showing the inside of a cooling device according to a modified example of the second embodiment, and FIG. 13(B) is a schematic diagram showing a partial cross-section of a part of the cooling device of (A). [Figure 13] 13A is a conceptual diagram showing a processing system according to a modified example of the second embodiment, and FIG. 13B is a conceptual diagram showing another configuration example of the processing system according to the modified example of the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention (simply referred to as an embodiment in this specification) will be described with reference to the drawings.

[0017] Embodiment 1 FIG. 1 shows a heat transfer device according to the first embodiment. Guidance A heat pipe 1 is shown as an example of a pipe. In the drawings such as Fig. 1, the symbol Ld indicates the longitudinal direction of the heat pipe 1, and the symbol Sd indicates the transverse direction of the heat pipe 1 that intersects with the longitudinal direction Ld (actually, perpendicular to the longitudinal direction Ld).

[0018] <Heat transfer tube> Heat Transfer GuidanceA heat pipe 1, which is an example of a tube, comprises a tube 10 having both ends 10a, 10b closed, a working fluid 12 sealed inside the tube 10 and vaporizing and liquefying, and a first liquid transfer section 15 and a second liquid transfer section 16 which are present along the longitudinal direction Ld inside the tube 10 and transport the liquefied working fluid 12 in the longitudinal direction Ld.

[0019] The tube 10 is a hollow tube made of a metal with a relatively high thermal conductivity, which has a circular cross section and is elongated in one direction. The circular cross section is not limited to a perfect circle, but may be a slightly distorted circle. A slightly distorted circle has a circularity of, for example, 200 μm or less. There is no particular limitation on the closing type or structure of both ends 10a, 10b of the tube 10, as long as they are sealed to such an extent that there is no risk of the working fluid 12 leaking. One of the ends 10a, 10b may have an end structure that is closed from the beginning.

[0020] For example, from the viewpoint of making the cross-sectional area of ​​the entire heat pipe 1 in the short direction Sd relatively small, a small-diameter cylindrical tube having a circular cross section with an outer diameter of 3 mm or less is used. Incidentally, from the viewpoint of manufacturability and securing a minimum strength, it is preferable that the outer diameter of the tube 10 is, for example, 2 mm or more. Moreover, it is preferable that the tube 10 is thin-walled, with the wall thickness being in the range of 0.05 mm or more and 0.2 mm or less. When the tube 10 is made smaller in diameter and thinner in this way, the installation space and heat capacity are reduced, and the thermal conductivity is improved.

[0021] Furthermore, the tube 10 may be made of metal materials such as stainless steel, aluminum, etc., but from the standpoint of obtaining high thermal conductivity and ease of processing, it is preferable to make it of oxygen-free copper (high-purity copper with a purity of 99.96% or more, containing almost no oxides). In addition, if there is a risk of the surface of the tube 10 being oxidized, it is preferable that the surface of the tube 10 is treated to prevent oxidation. Examples of the treatment to prevent oxidation include plating, application of an antioxidant, and coating.

[0022] The working fluid 12 is a medium that vaporizes (mainly evaporates) and liquefies (condenses) depending on the temperature distribution inside the tube 10. A required amount of the working fluid 12 is sealed inside the tube 10. In the first embodiment, for example, pure water is used as the working fluid 12. In addition, in Fig. 1 and the like, the working fluid 12 is illustrated in an exaggerated manner to facilitate understanding.

[0023] 1(A), both the first liquid transfer section 15 and the second liquid transfer section 16 are disposed so as to be present along the longitudinal direction Ld inside the tube 10, and are made of a material capable of transferring the liquefied working liquid 12 inside the tube 10 at least along the longitudinal direction Ld of the tube 10. The transfer of the liquefied working liquid 12 in the first liquid transfer section 15 and the second liquid transfer section 16 is performed by capillary force generated from a low temperature region in the tube 10 toward a high temperature region that is relatively higher in temperature.

[0024] As shown in Fig. 1(B), the first liquid transfer section 15 is disposed in a state of contacting the entire circumferential range of the inner wall surface 10c when viewed in a cross section perpendicular to the longitudinal direction Ld of the tube 10. In addition, the first liquid transfer section 15 is also disposed in a state of contacting a portion along the longitudinal direction Ld of the inner wall surface 10c of the tube 10 as shown in Fig. 1(A). The state in which the first liquid transfer section 15 contacts the entire inner wall surface 10c is not limited to the case where the first liquid transfer section 15 is in complete contact with the entire circumferential range of the inner wall surface 10c, but strictly speaking also includes the case where a part of the first liquid transfer section 15 is close to the inner wall surface 10c but is slightly floating and not in contact.

[0025] Such a first liquid transport section 15 is made of a material such as a plurality of wires made of metal, a metal mesh made by crossing a plurality of metal wires to form a mesh, or a sintered metal made by sintering metal powder. The first liquid transfer section 15 in the first embodiment is made of a mesh material (such as a wire net) made of metal wires. The first liquid transfer section 15 made of this mesh material is configured so that the mesh size is, for example, about 0.1 to 0.5 mm. The first liquid transfer section 15 made of this mesh material is formed as a material having a substantially cylindrical shape as a whole so that it can be inserted into the inside of the tube 10.

[0026] On the other hand, as shown in Figure 1 (B), the second liquid transfer section 16 is arranged in a non-contact state with both the inner wall surface 10c of the tube 10 and the first liquid transfer section 15 when viewed in a cross section perpendicular to the longitudinal direction Ld of the tube 10. The second liquid transfer section 16 is not in contact with either the inner wall surface 10c of the tube 10 or the first liquid transfer section 15, and thus the total surface area is increased by the amount of the non-contact with other parts, and a continuous space is secured along the longitudinal direction Ld. In addition, it is presumed that the heat received by the tube 10 from the external thermal environment is not conducted directly or via the first liquid transfer section 15, and the temperature tends to be kept relatively lower than that of the first liquid transfer section 15. In this case, the second liquid transport section 16 is also disposed in a state in which it exists along the longitudinal direction Ld of the inner wall surface 10c of the tube 10, as shown in FIG. 1(A).

[0027] Such a second liquid transfer section 16 is made of a material such as a plurality of wires made of metal, a bundle of a plurality of metal wires, a metal net made by crossing a plurality of metal wires into a net shape, etc. Among these, a bundle of a plurality of metal wires can be, for example, a twisted one. The second liquid transport section 16 in the first embodiment is made of a wire-shaped material obtained by twisting and bundling a plurality of metal wires. The second liquid transport section 16 made of the twisted wire-shaped material may be disposed so as to be in a non-contact state with the inner wall surface 10c of the pipe 10 and the first liquid transport section 15, but it is preferable that the occupancy rate (=(S1 / S2)×100) of the cross-sectional area S2 (the total area of ​​the cross-sectional areas of the wires) of the second liquid transport section 16 in the short-side direction Sd of the inside of the pipe 10 is 50% or less.

[0028] In addition, when both the first liquid transfer section 15 and the second liquid transfer section 16 are constructed using a material composed of a plurality of wires, it is preferable to use an extremely fine wire having an outer diameter of 0.06 mm or less. The first liquid transfer section 15 and the second liquid transfer section 16 composed of a plurality of extremely fine wires have a larger surface area and are more likely to obtain capillary force. In addition, when a small-diameter tube 10 having an outer diameter of 3 mm or less is applied, the first liquid transfer section 15 and the second liquid transfer section 16 composed of extremely fine wires are effective because they facilitate installation work such as inserting the tube 10 into the small-diameter tube 10.

[0029] Furthermore, when the first liquid transfer part 15 and the second liquid transfer part 16 are constructed using a material composed of a plurality of wires, both ends of the wires are fixed to both ends 10a, 10b of the pipe 10. In addition, for the first liquid transfer part 15, a method of contacting the inner wall surface 10c of the pipe 10 via a contact assistant such as grease having thermal conductivity can be applied.

[0030] Next, a test carried out to examine the thermal conduction performance of this heat pipe 1 will be described.

[0031] In the test, a heat pipe 1 of the embodiment having the configuration shown in FIG. 3(A) and a heat pipe 1X of the comparative example having the configuration shown in FIG. 3(B) were prepared, and each of the heat pipes 1 and 1X was placed in the measuring device 200 shown in FIG. 2. After that, the temperature difference between two points near the heat pipes when the measuring device 200 was operated was measured as an evaluation index for thermal conduction performance.

[0032] The heat pipe 1 of the embodiment was prepared by preparing an oxygen-free copper tube 10 (length in the longitudinal direction Ld: 320 mm) having an outer diameter of 2 to 3 mm, a circular cross section, and a wall thickness of approximately 0.1 to 0.2 mm, with a first liquid transfer section 15 arranged in contact with the entire circumference of the inner wall surface 10c of the tube 10, as shown in Figure 3(A), and a second liquid transfer section 16 arranged in a non-contact state with both the inner wall surface 10c of the tube 10 and the first liquid transfer section 15. A mesh material (mesh thickness: 0.01-0.10 mm) made of copper wire (wire diameter: 0.01-0.05 mm) was used as the first liquid transfer section 15. A linear material made of 100 copper wires (wire diameter: 0.01-0.05 mm) twisted together was used as the second liquid transfer section 16. The heat pipe 1 of this example had a heat capacity of 1.35 (J / K). This heat capacity was determined using information obtained by measuring the specific heat, density, and volume of the heat pipe 1.

[0033] A comparative heat pipe 1X was prepared by arranging a tube 10 having the same configuration as the tube 10 in the heat pipe 1 of the embodiment without disposing the first liquid transport part 15 and only disposing the second liquid transport part 16 so as to be in a non-contact state with the inner wall surface 10c of the tube 10 as shown in Fig. 3(B). The second liquid transport part 16 was made of the same linear material as the second liquid transport part 16 in the heat pipe 1 of the embodiment. The heat capacity of the heat pipe 1X of the comparative example was 1.5 (J / K). The reason that the heat capacity of the heat pipe 1X of the comparative example was larger than that of the heat pipe 1 of the embodiment is considered to be due to the difference in density caused by the difference in the liquid transfer part (wick).

[0034] 2, the measuring device 200 is composed of a measuring stage 201 made of a rectangular aluminum plate, a heat sink plate 202 made of aluminum arranged in the center of the underside of the measuring stage 201, heating plates 203A and 203B made of aluminum arranged on both ends of the underside of the measuring stage 201 in the longitudinal direction adjacent to the heat sink plate 202, heaters (sheet heaters) 205A and 205B arranged on the undersides of the heating plates 203A and 203B, respectively, a pressing member 206 that presses and holds the heat pipe 1 etc. against the measuring stage 201, and thermocouples 207a and 207b that measure temperature. The numbers in parentheses in FIG. 2 indicate the dimensions (mm) of each of the above components. The heat sink 202 and the heating plate 203 are both aluminum plates, with the only difference being that the thickness (TBD: 100 mm) of the heat sink 202 is thicker than that of the heating plate 203.

[0035] In this test, the measurements were carried out as follows.

[0036] First, the heat pipe 1, 1X to be measured is prepared by placing it on the measurement stage 201 of the measurement device 200 in a position where the first liquid transfer part 15 is located at the lowest part of the pipe 10 and faces the measurement stage 201, as shown in Fig. 2. At this time, the heat pipe 1, 1X is held on the measurement stage 201 via thermally conductive grease 204. As the grease 204, for example, one having a thermal conductivity of 1 to 10 W / m / K is used.

[0037] Next, the output of heaters 205A, 205B is adjusted to obtain a first measured temperature by inner thermocouple 207b, which is located inside the end of measurement stage 201, when the measured temperature by outer thermocouple 207a, which is located on the end side of measurement stage 201, stabilizes at the first test temperature of 150°C. Also, the outputs of heaters 205A and 205B are adjusted to obtain a second measured temperature by inner thermocouple 207b when the measured temperature by outer thermocouple 207a is stabilized at a second test temperature of 230°C.

[0038] Then, the temperature difference between the first test temperature and the first measured temperature and the temperature difference between the second test temperature and the second measured temperature for one heat pipe 1 (or 1X) were averaged over a certain period of time to obtain the temperature difference (characteristic) of the measured heat pipe 1 (or 1X). The measurement results of the heat pipes 1 and 1X are shown in Fig. 3(C). The smaller the temperature difference, the better the thermal conduction, and it is desirable that the temperature difference T is at an acceptable level, for example, 37°C or less.

[0039] 3(C), the heat pipe 1 of the embodiment met the allowable level of temperature difference T of 37° C. or less. On the other hand, the heat pipe 1X of the comparative example did not meet the allowable level of temperature difference T.

[0040] Also, the smaller the temperature difference measured in this test, the smaller the temperature difference between the part heated by heater 205A etc. and the unheated part on the inside adjacent to the heated part tends to be due to good heat transfer (heat transport) by the heat pipe, indicating good thermal conductivity. Conversely, the larger the measured temperature difference, the less heat is transferred by the heat pipe, indicating relatively poor thermal conductivity. In other words, it seems that there is a correlation between the magnitude of the temperature difference measured in this test and the quality of the thermal conductivity performance in the longitudinal direction Ld of the heat pipe.

[0041] Therefore, it is recognized from this test that the heat pipe 1 having the configuration of the embodiment can improve the thermal conduction performance in the longitudinal direction Ld compared to the heat pipe 1X of the comparative example. In other words, it was found that when the first liquid transport section 15 and the second liquid transport section 16 are arranged as in the heat pipe 1 of the embodiment, the temperature difference can be suppressed and the thermal conduction performance in the longitudinal direction Ld is improved compared to the heat pipe 1X of the comparative example in which only the second liquid transport section 16 is arranged.

[0042] <Modification of the first embodiment> The heat pipe 1 according to the first embodiment may be arranged so that the first liquid transfer section 15 is in contact with a part of the inner wall surface 10c of the tube 10 in the circumferential direction, as shown in FIG. 4(A), the first liquid transfer section 15 is disposed so as to be present also along the longitudinal direction Ld inside the tube 10. In this heat pipe 1, the second liquid transfer section 16 may be formed of, for example, the above-mentioned mesh material.

[0043] The heat pipe 1 of this modified example is used with the portion where the first liquid transport section 15 is arranged in contact with the portion to which heat is to be transferred. Moreover, when the above test was also carried out on the heat pipe 1 of this modified example, results with approximately the same tendency were obtained.

[0044] Embodiment 2 5 and 6 show configuration examples according to the embodiment 2. Fig. 5 shows a processing system 7 according to the embodiment 2, and Fig. 6 shows a heat treatment apparatus 5 according to the embodiment 2. In the following description, the direction indicated by the arrow X in the drawings is the width direction of the device, the direction indicated by the arrow Y is the height direction of the device, and the direction indicated by the arrow Z is the depth direction of the device perpendicular to the width and height directions. The circle at the intersection of the arrows X and Y in the drawings indicates that the depth direction of the device (arrow Z) faces downward perpendicular to the drawing.

[0045] The processing system 7 includes a heat treatment device 5 having a heat treatment section which exchanges heat with the workpiece 9 passing through in contact with it, and another processing device 2 which performs processing other than the heat exchange on the workpiece 9 before or after it passes through the heat treatment device 5. The heat treatment device 5 also includes a heat treatment section 5h that exchanges heat with the workpiece 9 passing through it in contact with it, and a heat conduction pipe 1 that is installed across a portion of the heat treatment section 5h that corresponds to a passing region E1 through which the workpiece 9 passes and a portion that corresponds to a non-passing region E2 through which the workpiece 9 does not pass.

[0046] In the second embodiment, an image forming apparatus 7A that performs a process of forming an image on a workpiece 9 is applied as an example of a processing system 7. In the second embodiment, since the processing system 7 is the image forming apparatus 7A, a heating apparatus 5A having a heat processing section that performs heat exchange to heat the workpiece 9 is applied as an example of a heat processing apparatus 5, an image forming apparatus 2A that performs an image forming process, which is a process other than a heating process, on the workpiece 9 before it passes through the heating apparatus 5A is applied as an example of another processing apparatus 2, and a recording sheet 9A on which an image is formed is applied as an example of the workpiece 9.

[0047] <Processing System> The image forming apparatus 7A, which is an example of the processing system 7, is an apparatus that forms an image by forming an image made of a developer, which is an example of powder, on a recording sheet 9A and then fixing the image by heating. 5, this image forming apparatus 7A has a housing 70 having a required external shape, and is configured by arranging an image forming device 2A, a sheet supplying device 4, a heating device 5A, etc. in the internal space of the housing 70. The dashed dotted lines in FIG. 5 indicate the main transport path along which the recording sheet 9A is transported within the housing 70.

[0048] The image forming device 2A is a device that forms a toner image made of toner as a developer and transfers it to a recording sheet 9A. The image forming device 2A has a photosensitive drum 21 that rotates in the direction indicated by the arrow A, and is configured by arranging devices such as a charging device 22, an exposure device 23, a developing device 24, a transfer device 25, and a cleaning device 26 around the photosensitive drum 21.

[0049] Among these, the photosensitive drum 21 is an example of an image holding means, and is a photosensitive body in the form of a drum having an image forming surface and a photosensitive layer that becomes the image holding surface. The charging device 22 is a device that charges the outer peripheral surface (image forming surface) of the photosensitive drum 21 to a required surface potential. The charging device 22 is configured to include a charging member in the form of, for example, a roll that is brought into contact with the image forming surface of the outer peripheral surface of the photosensitive drum 21 and is supplied with a charging current.

[0050] The exposure device 23 is a device that exposes the charged outer peripheral surface of the photosensitive drum 21 based on image information to form an electrostatic latent image. The exposure device 23 operates by receiving an image signal generated by performing required processing on image information input from the outside by an image processing means (not shown). The image information is information on the image to be formed, such as characters, figures, photographs, patterns, etc. The development device 24 is a device that develops the electrostatic latent image formed on the outer peripheral surface of the photosensitive drum 21 with a developer (toner) of a corresponding predetermined color (e.g., black) to visualize it as a monochromatic toner image.

[0051] Next, the transfer device 25 is a device that electrostatically transfers the toner image formed on the outer peripheral surface of the photosensitive drum 21 to the recording sheet 9A. This transfer device 25 is configured to include a transfer member in the form of a roll or the like that comes into contact with the outer peripheral surface of the photosensitive drum 21 and is supplied with a transfer current. The cleaning device 26 is a device that cleans the outer peripheral surface of the photosensitive drum 21 by removing unnecessary toner, paper powder, and other unnecessary matters that adhere to the outer peripheral surface of the photosensitive drum 21. In the image forming device 2A, the portion where the photosensitive drum 21 and the transfer device 25 face each other is the transfer position TP where the toner image is transferred.

[0052] The sheet supplying device 4 is a device that stores and sends out recording sheets 9A to be supplied to a transfer position TP in the image forming device 2A. This sheet supplying device 4 is configured by arranging devices such as one or more containers 41 that store recording sheets 9A and one or more feeders 43 that feed out recording sheets 9A.

[0053] The container 41 is a container member having a loading plate (not shown) for loading and storing a plurality of recording sheets 9A in a required orientation. The delivery device 43 is a device for feeding the recording sheets 9A loaded on the loading plate of the container 41 one by one using a device such as a plurality of rolls. The sheet supply device 4 in the second embodiment has, for example, two containers 41a and 41b capable of individually storing recording sheets 9Aa and 9Ab having different widths during transport, and two delivery devices 43a and 43b for individually delivering the recording sheets 9Aa and 9Ab stored in the containers 41a and 41b, respectively.

[0054] The sheet supply device 4 is connected to the transfer position TP in the image forming device 2A by a supply conveying path 45, which is an example of a conveying means. The supply conveying path 45 is a conveying path that conveys and supplies the recording sheet 9A (9Aa or 9Ab) sent out from the sheet supply device 4 to the transfer position TP, and is configured by arranging a plurality of conveying rolls 46a, 46b that clamp and convey the recording sheet 9A, a plurality of guide members (not shown) that ensure a conveying space for the recording sheet 9A and guide the conveyance of the recording sheet 9A, and the like. Furthermore, the recording sheet 9A is not particularly limited in terms of its material, shape, etc., so long as it is a sheet-like recording medium that can be transported within the housing 70 and onto which a toner image can be transferred and thermally fixed.

[0055] The heating device 5A is a device that applies heat and pressure to thermally fix the unfixed toner image transferred at the transfer position TP of the imaging device 2A onto the recording sheet 9A. The heating device 5A is configured by arranging devices such as a heating rotor 51 and a pressure rotor 52 in the internal space of a housing 50 in which an inlet 50a and an outlet 50b for the recording sheet 9A are provided. 5 and 6, in the heating device 5A, the heating rotator 51 and the pressurizing rotator 52 are arranged to rotate in contact with each other, and the recording sheet 9A passing through is heated and pressurized at the contact portion FN. In the heating device 5A, the portion consisting of the heating rotator 51 and the pressurizing rotator 52 is a heat treatment portion 5h. The heating device 5A will be described in detail later.

[0056] In the image forming apparatus 7A, an image is formed, for example, as follows.

[0057] That is, in the image forming device 7A, when a control means (not shown) receives a command to form an image, the image creating device 2A performs charging, exposing, developing and transferring operations, while the sheet supplying device 4 sends out the required recording sheet 9A (9Aa or 9Ab) and transports it via the supply conveying path 45 to the transfer position TP for supply. As a result, a toner image corresponding to the image information is formed on the photosensitive drum 21, and the toner image is transferred to the recording sheet 9A supplied from the sheet supply device 4 to the transfer position TP. At this time, the recording sheet 9A to which the toner image has been transferred is peeled off from the photosensitive drum 21 while being sandwiched between the rotating photosensitive drum 21 and the transfer device 25, and is sent toward the heating device 5A.

[0058] Next, in the image forming apparatus 7A, the heating device 5A performs a fixing operation in which the recording sheet 9A onto which the toner image 92 has been transferred is heated and pressurized when the recording sheet 9A is introduced into and passes through the contact portion FN as shown in Fig. 6. As a result, the unfixed toner image 92 is melted under pressure and fixed onto the recording sheet 9A. At this time, the heating rotator 51 and the pressurizing rotator 52 function as a conveying means for conveying the recording sheet 9A.

[0059] After fixing, the recording sheet 9A is discharged from the housing 50 while sandwiched between the heating rotor 51 and the pressure rotor 52 in the heating device 5A, then transported to the discharge outlet 72 via the discharge conveying path, and finally sent by the discharge roll 48 to a sheet storage section 73 provided in part of the housing 70 and stored therein.

[0060] This completes the basic image forming operation of the image forming apparatus 7A for forming a monochrome image on one side of one recording sheet 9A.

[0061] <Heat treatment equipment> Next, the heating device 5A, which is an example of the heat treatment device 5, will be described in detail.

[0062] As shown in Figures 6, 7, etc., the heating device 5A of embodiment 2 uses a belt-nip type heating unit 55 as the heating rotor 51, which is composed of a rotatable heating belt 53 and a heating element 54, which is an example of a heating means that presses the heating belt 53 from its inner surface against the pressurizing rotor 52 to form a contact part (nip) FN and generates heat to heat the heating belt 53, and uses a roll-shaped pressure roll 56 as the pressurizing rotor 52.

[0063] Of these, the heating unit 55 performs a heat treatment to heat the recording sheet 9A at a portion FN that contacts the recording sheet 9A in a width direction Wd (FIG. 7, etc.) that intersects with the conveying direction C of the recording sheet 9A. The heating unit 55 is configured so that the heating element 54 is held in contact with the inner circumferential surface of the heating belt 53 by a contact holder 61, and the heating belt 53 is rotatably held by a part of the contact holder 61 and left and right end holders 62A, 62B. The heating unit 55 supports the contact holder 61 and the left and right end holders 62A, 62B by a support 63.

[0064] The heating belt 53 is an endless belt for heat conduction that has flexibility and heat resistance. For example, a belt formed into a cylindrical shape using a synthetic resin material such as polyimide or polyamide is used as the heating belt 53.

[0065] As shown in Figures 8, 9, etc., the heating element 54 is composed of a substrate 541, multiple (three in this example) heating portions 542A, 542B, 542C provided on one side 541a of the substrate 541 that contacts the inner surface of the heating belt 53, and a wiring portion 543 for supplying power to the heating portions 542A, 542B, 542C.

[0066] The substrate 541 is a rectangular plate-like member having a width W in a passing width direction Wd intersecting with the conveying direction C of the recording sheet 9A that is longer than the maximum width W1. The substrate 541 is made of an electrically insulating material, and for example, a ceramic substrate is used. A surface (one surface) 541a of the substrate 541 that contacts the inner circumferential surface of the heating belt 53 is covered with a coating layer formed thereon after the heat generating portions 542A, 542B, and 542C are provided.

[0067] As shown in FIG. 9(A), the heat generating portions 542A, 542B, and 542C are heating wire portions that are linearly arranged on one side 541a of the substrate 541 along its longitudinal direction (the direction along the passing width direction Wd of the recording sheet 9A) and are parallel to and spaced apart from each other in the passing width direction Wd of the recording sheet 9A. 9(A) is a drawing showing a state seen from the back surface (other surface) 541b of one surface 541a of the substrate 541 of the heat generating element 54, and therefore heat generating portion 542 provided on one surface 541a is not actually visible. However, in FIG. 9(A), for the convenience of explaining heat generating portion 542, heat generating portion 542 is drawn in a state where it can be seen through other surface 541b.

[0068] Furthermore, the heat generating portions 542A, 542B, and 542C have approximately the same length in the longitudinal direction of the substrate 541, but are configured to have areas that generate relatively more heat in different positions to accommodate differences in the width size W of the recording sheet 9A when it is transported. That is, as shown in Fig. 9(A), the first heat generating portion 542A is configured such that a central portion excluding both end portions in the longitudinal direction becomes a region where a large amount of heat is generated. This first heat generating portion 542A is used when a recording sheet 9A having an intermediate width size W2 (<W1) in the width size W passes through. Further, the second heat generating portion 542B is configured such that a portion corresponding to both end portions of the first heat generating portion 542A becomes a region where a large amount of heat is generated. Furthermore, the third heat generating portion 542C is configured such that a central portion in the longitudinal direction (for example, a portion about 1 / 3 of the entire length) becomes a region where a large amount of heat is generated. The third heat generating portion 542C is used when a recording sheet 9A having a minimum size W3 (<W2) in the width size W passes through.

[0069] Incidentally, the configuration of the regions where the heat generating portions 542A, 542B, and 542C in Embodiment 2 relatively generate a large amount of heat is such that the central position in the passing width direction Wd during the conveyance of the recording sheet 9A passes through, for example, the central position serving as a reference for the passing region width of the recording sheet 9A at the contact portion FN of the heating device 5A. This is the case when adopting a central reference conveyance method (center registration method) in which the recording sheet 9A is guided and conveyed. Also, for the regions where the heat generating portions 542A, 542B, and 542C relatively generate a large amount of heat, for example, at least one of the width and thickness of the heating wire portion is made narrower or thinner or both than other portions (portions where heat generation is suppressed) so that the electrical resistance value becomes relatively higher. Furthermore, regarding the temperature of the heating element 54 due to the heat generation of the heat generating portions 542A, 542B, and 542C, it is measured by a temperature sensor (not shown) arranged to contact necessary locations on the other surface 541b of the substrate 541 of the heating element 54, and the measurement information is fed back to a heating control unit (not shown).

[0070] As shown in Fig. 9(A) and the like, the wiring portion 543 is provided such that its bus bar portion exists at one end portion in the longitudinal direction of the heating element 54 and outside one of the end holders 62A and 62B. The wiring portion 543 in Embodiment 2 is configured as an end portion obtained by extending one end portion of the substrate 541 to the outside of the right end holder 62B. Furthermore, the wiring section 543 is composed of an electrically insulating substrate 543a, individual wiring sections 543b, 543c, and 543d which are individually connected to one end of each of the heat generating sections 542A, 542B, and 542C as shown by dashed lines in Figure 9(A), and a common wiring section 543e which is commonly connected to the other end of each of the heat generating sections 542A, 542B, and 542C as shown by the dotted areas and dashed lines in Figure 9(A).

[0071] The heating element 54 is connected to a power supply connection part 64 that supplies power to the wiring part 543 and thus to the heating part 542 as shown in FIG.

[0072] The power supply connection section 64 in embodiment 2 is composed of a housing (connector body) 641 having a detachable shape for connection, and a plurality of contact terminals 642 that are provided on one side of the housing 641 and connected to the connection ends of each wiring of the wiring section 543 in an exposed state. This power supply connection section 64 is connected to a power supply source connection section 14 that is routed and extends from a power supply section (not shown) in an image forming apparatus 7A as shown in FIG. 9A, for example, and is placed in a state in which electricity can be passed therethrough.

[0073] As shown in Figure 8 (B) etc., the contact holder 61 is a plate-shaped member that is long in one direction and has a accommodating recess 61a that accommodates and holds the heating element 54 on one side that comes into contact with the inner surface of the heating belt 53. Moreover, the contact holder 61 is provided on the other surface opposite to the one surface thereof with a mounting groove portion 61b and a mounting contact portion 61c that are used when mounting the contact holder 61 to the support body 63. Furthermore, one long side end of the contact holder 61 on the side on which the accommodating recess 61a is provided is formed as an introduction guide portion 61d consisting of a curved surface that guides the heating belt 53 to be introduced into the contact portion FN, and the other long side end of the same side is formed as an extraction guide portion 61e consisting of a curved surface that guides the heating belt 53 in a direction away from the contact portion FN.

[0074] Both the left and right end holders 62A, 62B are members in which curved guide holders 622 that guide and hold both ends in the width direction of the heating belt 53 so that they can rotate from their inner peripheral surface are provided on the inner surface of a disk-shaped main body 621 that is partially cut off from the portion facing the pressure roll 56. Also, the left and right end holders 62A, 62B are provided with mounting recesses (not shown) on the inside of the belt guide holders 622 of the main body 621 for mounting to the ends of the support body 63.

[0075] As shown in Fig. 7 and other figures, the support 63 is a member that is longer than the longitudinal length of the heating element 54. As shown in Fig. 8 and other figures, for example, a member in the form of a flat plate that is long in one direction and has a long side end bent at a substantially right angle in the same direction so that the cross section has a concave shape is used as the support 63. 8(B) and other figures, when the contact holder 61 is attached, one bent end 63b of the support 63 is fitted into the attachment groove 61b of the contact holder 61, while the other bent end 63c is kept in contact with the attachment contact portion 61c of the contact holder 61. In this way, the support 63 supports a part of the contact holder 61 by clamping it in the longitudinal direction.

[0076] The pressure roll 56 serving as the pressure rotating body 52 is, for example, a columnar or cylindrical roll base made of metal or the like, on the outer circumferential surface of which an elastic layer and a release layer are provided.

[0077] As shown in Fig. 7, shafts 56c and 56d at both axial ends of the pressure roll 56 are rotatably supported by a pressure mechanism (not shown) disposed in the housing 50. The pressure roll 56 receives pressure from the pressure mechanism to press the pressure roll 56 against the heating unit 55. As a result, the pressure roll 56 is kept in a state in which its outer circumferential surface is pressed against one surface 541a of the heating element 54 at a required pressure across the longitudinal direction via the heating belt 53 in the heating unit 55, as shown in Figs. The portion where the pressure roll 56 is in pressure contact with the heating unit 55 becomes the contact portion FN.

[0078] 7, the pressure roll 56 has a power-driven gear 75, which is an example of a drive input means, attached to one shaft portion 56c, and the power-driven gear 75 meshes with a power transmission gear (not shown) of a drive transmission device 76 arranged on the housing 70 side of the image forming apparatus 7A. As a result, when a required time for an image forming operation or the like arrives, the pressure roll 56 is driven to rotate at a required speed in the direction indicated by arrow B1 by receiving a rotational force transmitted and input from the drive transmission device 76, as shown in FIG. When the pressure roll 56 rotates and drives, as shown in FIG. 6, the heating belt 53 in the heating unit 55 rotates accordingly in the direction indicated by the arrow B2.

[0079] In addition, the heating device 5A is configured such that, when an image forming operation is performed, the heated area of ​​the heating element 54 of the heating unit 55 is adjusted in accordance with the difference in the width size W of the recording sheet 9A passing through the contact portion FN.

[0080] For example, when a recording sheet 9A having a maximum width W1 during conveyance is passed, power is supplied to both the first heating section 542A and the second heating section 542B to heat the area corresponding to the maximum width W1. When a recording sheet 9A having a minimum width W3 is passed, power is supplied only to the third heating section 542C to heat the area corresponding to the minimum width W3. When a recording sheet 9A having a medium width W2 is passed, power is supplied only to the first heating section 542A to heat the area corresponding to the medium width W2. Thus, the heating device 5A is adapted so that the heating element 54 of the heating unit 55 is adapted to the difference in the width W of the recording sheet 9A and efficiently generates heat.

[0081] On the other hand, even in this heating device 5A, when recording sheets 9A with a width size W (sizes including intermediate width size W2 and minimum size W3) smaller than the maximum width size W1 are continuously passed through and heated, a non-passage area E2 is generated in the contact portion FN (actually the heating element 54) where the recording sheets 9A do not pass through. Therefore, the non-passage area E2 continues to be heated from the portion of the heating section 542 where heat generation is suppressed without heat being taken away by the passing recording sheets 9A, and the temperature is likely to rise. In this case, the portion of the heating element 54 corresponding to the non-passage area E2 becomes relatively hotter than the passage area E1 through which the recording sheet 9A passes, resulting in a temperature difference.As a result, when a wider width recording sheet 9A is subsequently passed and heated, uneven heating may be induced, or the contact holder 61 may be adversely affected by localized heating.

[0082] That is, in the heating device 5A, when the above-mentioned heat treatment is performed, the heating element 54 in the heat processing section 5h of the heating device 5A is in a state in which an unnecessary temperature difference occurs between the passing region E1 through which the recording sheet 9A passes and the non-passing region E2 of the recording sheet 9A, as shown in Figures 7 and 10. At this time, the portion of the heating element 54 corresponding to the non-passing region E2 becomes a high-temperature portion that is heated during the heat treatment and causes the temperature difference, while the portion of the heating element 54 corresponding to the passing region E1 becomes a low-temperature portion that is relatively lower in temperature than the portion (high-temperature portion) corresponding to the non-passing region E2 during the heat treatment and causes the temperature difference.

[0083] Therefore, in the heating device 5A, from the viewpoint of suppressing the occurrence of a temperature difference due to an unnecessary rise in temperature in a portion (high temperature portion) corresponding to the non-passage area E2 of the heating element 54, two heat pipes 1A and 1B are arranged in contact with a surface (back surface) 541b opposite to a surface 541a of the heating element 54 in the heating unit 55 that contacts the heating belt 53, as shown in Figures 6, 7, 10, etc. Here, the high temperature portion is a portion that generates a temperature at least high enough to vaporize the working fluid 12 sealed in the heat pipes 1A and 1B, for example, a portion that reaches a temperature of 150°C or higher.

[0084] The heat pipe 1 having the configuration according to the first embodiment is applied to both the heat pipes 1A and 1B. 9 and other figures, the heat pipes 1A, 1B have approximately the same length as the heat generating portion 542 of the heat generating element 54. Furthermore, since the two heat pipes 1A, 1B are arranged in parallel in a location with limited installation space, heat pipes with a relatively small diameter (for example, an outer diameter in the range of 2 to 3 mm) are used.

[0085] As shown in Figures 7, 10, etc., these heat pipes 1A, 1B are in contact along the longitudinal direction (the direction along the passing width direction Wd of the recording sheet 9A) of the other surface 541b of the heating element 54, and are arranged so as to be parallel with a required gap in the conveying direction C of the recording sheet 9A.

[0086] In the second embodiment, the heat pipes 1A and 1B are arranged as follows. That is, as shown in FIG. 8 and the like, first, mounting grooves 65A and 65B for mounting the heat pipes 1A and 1B are provided in the accommodating recess 61a of the contact holder 61, and the heat pipes 1A and 1B are mounted so as to be accommodated in the mounting grooves 65A and 65B. Next, the heat generating element 54 is accommodated in the accommodating recess 61a of the contact holder 61, so that the other surface 541b of the heat generating element 54 comes into contact with the heat pipes 1A and 1B and presses them into the mounting grooves 65A and 65B. The heat pipes 1A and 1B may be fixed by partially adhering them to the other surface 541b of the heat generating element 54 with a thermally conductive material such as adhesive or grease.

[0087] 7, etc., of the heating element 54 in the heat treatment section 5h, the heat pipes 1A and 1B are arranged so as to be in contact with a portion (low temperature portion if there is a non-passage area E2) of the heating element 54 corresponding to the passage area E1 through which the recording sheet 9A of the maximum width size W1 passes, including at least a portion (high temperature portion) corresponding to the non-passage area E2. In this case, the heat pipes 1A and 1B are arranged so that the second liquid transfer section 16 is not in contact with either the inner wall surface 10c of the tube 10 or the first liquid transfer section 15 in the region in contact with the portion (high temperature portion) corresponding to the passage area E1 through which the recording sheet 9A of the maximum width size W1 passes, including the portion (high temperature portion) corresponding to the non-passage area E2. Furthermore, in this heating device 5A, the heat pipes 1A and 1B are positioned so that the first liquid transfer section 15 is in contact with the portion of the inner wall surface 10c (Figure 1, etc.) inside the tube 10 that faces the heating element 54.

[0088] In the heating device 5A in which the heat pipes 1A, 1B are arranged, even if a portion of the heating element 54 at the contact point FN corresponds to a non-passage area E2 through which the recording sheet 9A does not pass and the temperature rises, the heat of the portion of the heating element 54 corresponding to the non-passage area E2 is transferred by the heat transfer action of the heat pipes 1A, 1B to a portion (low temperature portion) corresponding to the passage area E1 of the recording sheet 9A, which becomes relatively lower in temperature than the portion (high temperature portion) corresponding to the non-passage area E2.

[0089] At this time, heat transfer between the heat pipes 1A and 1B is roughly as follows.

[0090] For example, in both heat pipes 1A and 1B, heat is conducted in a portion of tube 10 that contacts the portion of heating element 54 that corresponds to non-passage area E2 of recording sheet 9A (high temperature portion), and working fluid 12 inside that portion of tube 10 is heated and vaporized. At this time, the corresponding portion of heat pipes 1A and 1B absorbs heat required for vaporization. Then, the vaporized working fluid 12 moves toward a portion of tube 10 where the temperature and pressure are relatively low due to the increase in temperature and pressure accompanying the vaporization (mainly evaporation). At this time, the portion of tube 10 where the temperature and pressure are relatively low is the portion located toward the center of tube 10 that contacts the portion of heating element 54 that corresponds to pass area E1 of recording sheet 9A (low temperature portion). Meanwhile, in the portion of tube 10 that contacts the portion (low temperature portion) of tube 10 that corresponds to passage area E1 of recording sheet 9A, vaporized working liquid 12 (vapor) is cooled and condenses to liquefy. At this time, the corresponding portion of heat pipes 1A, 1B releases the heat of condensation generated by liquefaction and dissipates heat. Then, the liquefied working liquid 12 moves by the capillary force of first liquid transfer section 15 substantially along the longitudinal direction Ld of tube 10 to the portion (high temperature portion) that contacts the portion that corresponds to non-passage area E2 of recording sheet 9A.

[0091] In the heat pipes 1A and 1B, the above operation is repeated, so that heat is transferred from relatively high-temperature parts to relatively low-temperature parts in the tube 10 substantially along the longitudinal direction Ld of the tube 10. As a result, in the heating element 54 with which the heat pipes 1A and 1B come into contact, heat is transferred from the part (high-temperature part) corresponding to the non-passage area E2 to the part (low-temperature part) corresponding to the passage area E1 of the recording sheet 9A, where heat exchange occurs.

[0092] As a result, in the heating device 5A, as shown in Fig. 11(A), compared to a case where the heat pipes 1A, 1B are not provided (conventional), the temperature in the non-passage area E2 is prevented from rising higher than the temperature in the pass-through area E1, and the temperature difference Δt occurring in the heating element 54 constituting the main part of the heat treatment section 5h is suppressed. This temperature difference Δt is at least an unnecessary temperature difference.

[0093] In particular, in the heat pipes 1A and 1B, the first liquid transfer section 15 is disposed in contact with the inner wall surface 10c inside the tube 10, so that the heat received by the tube 10 is rapidly conducted to the first liquid transfer section 15, and the working liquid 12 attached to or near the first liquid transfer section 15 is easily vaporized, and the vaporized working liquid 12 is also easily moved through the space between the first liquid transfer section 15 and the second liquid transfer section 16. In addition, the second liquid transfer section 16 is disposed in a state of not contacting both the inner wall surface 10c inside the tube 10 and the first liquid transfer section 15, so that the heat received by the tube 10 is conducted more slowly than the first liquid transfer section 15, but the temperature is kept relatively low, and the vaporized working liquid 12 (vapor) is quickly liquefied when it comes into contact with the second liquid transfer section 16, and the transfer of the working liquid 12 is also facilitated by the capillary force of the second liquid transfer section 16. Therefore, in the heat pipes 1A and 1B, the working fluid 12 circulates efficiently inside the pipe 10, and heat is also transferred efficiently.

[0094] As a result, in the heating device 5A, the temperature difference occurring in the passing width direction Wd of the heat generating element 54 of the heat processing part 5h, that is, the unnecessary temperature difference occurring between the high temperature part corresponding to the non-passing area E2 and the low temperature part corresponding to the passing area E1 generated by the heat generating element 54, is efficiently suppressed. In particular, in this heating device 5A, the heat generating element 54 heats the toner image to a range of, for example, 150 to 230°C in order to heat and melt the image and fix it well on the recording sheet 9A, and the unnecessary temperature difference occurring in the heat generating element 54 is also effectively suppressed, despite the use of the above-mentioned relatively small diameter heat pipes 1A and 1B. It is clear from the above test results that this temperature difference suppression effect can be obtained.

[0095] Therefore, in the heating device 5A, even when recording sheets 9A of a width size W (including intermediate width size W2 and minimum size W3) smaller than the maximum width size W1 are successively passed, and then recording sheets 9A of a width size W (W1 or W2) relatively wider than the smaller width size W (W2 or W3) are passed for heating processing, heating can be performed with little variation in heating temperature due to the above-mentioned unnecessary temperature difference.

[0096] In addition, in the image forming device 7A, even when recording sheets 9A with relatively small width sizes W (W2, W3) are used in succession and then a recording sheet 9A with width sizes W (W1, W2) relatively wider than the small width sizes W (W2, W3) is used to form an image, the toner image formed by the imaging device 2A is fixed satisfactorily by heating in the heating device 5A with less variation in heating temperature caused by the above-mentioned unnecessary temperature difference. As a result, the image forming device 7A can obtain a homogeneous image with less fixing unevenness (heating unevenness) caused by the above-mentioned unnecessary temperature difference.

[0097] Incidentally, the warm-up time, which is the time required for the heating device 5A to be heated to a predetermined temperature when the power is turned on, was investigated. The warm-up time was measured by measuring the time required for the temperature to reach the predetermined temperature of 200° C. using the outer thermocouple 207a (FIG. 2) in the measuring device 200 that simulates the main part (heating element 54) of the heat treatment part 5h of the heating device 5A. For comparison, a similar measurement was also performed using the heat pipe 1X of the comparative example. The measurement results at this time are shown in FIG.

[0098] From the results shown in FIG. 11(B), it is understood that when the heat pipe 1 of the embodiment is used, the warm-up time can be shortened compared to when the heat pipe 1X of the comparative example is used. For this reason, with this heating device 5A, in addition to obtaining the effect of suppressing the above-mentioned temperature difference (Δt) (FIG. 3(C)), the effect of shortening the warm-up time is also obtained.

[0099] <Modification of the second embodiment> In the second embodiment, a heating device 5A is exemplified as the heat treatment device 5. However, the heat treatment device 5 may also be, for example, a cooling device 5B equipped with a heat treatment section 5j that performs heat exchange to cool the workpiece 9 passing through in contact therewith, as shown in FIG. 12.

[0100] This cooling device 5B is configured by arranging, in the internal space of a housing 50 in which an inlet 50a and an outlet 50b for the workpiece 9 are provided, equipment such as a transport device 57 for the workpiece 9, a cooling section 58 which is an example of a heat treatment section 5j that cools the workpiece 9 transported by the transport device 57, and a pressing rotor 59 that presses the workpiece 9 against the cooling section 58.

[0101] Among these, for example, a sheet-like or plate-like object to be cooled is applied as the workpiece 9. In the cooling device 5B, for example, the workpiece 9 is targeted for those whose feed width W is the maximum width size W1 and those whose feed width W is an intermediate width size W2 narrower than the maximum width size W1. For example, a belt conveying type device is used as the conveying device 57. Specifically, the conveying device 57 is composed of an endless conveying belt 57a having thermal conductivity, support rolls 57b and 57c that support the conveying belt 57a so as to rotate it in the direction indicated by the arrow, and a driving device (not shown) that transmits rotational power to one of the support rolls 57b and 57c. For example, a roller-shaped pressing rotor 59 is used as the pressing rotor 59. The pressing rotor 59 is disposed so as to press the conveyor belt 57a of the conveyor device 57 against the cooling unit 58 and rotate in response to the pressing.

[0102] The cooling section 58 is arranged in contact with the inner surface of the conveyor belt 57a of the conveyor device 57 and configured as a processing section for performing cooling. Specifically, the cooling section 58 is configured with a thermally conductive support 58a and a cooling body 58b that continuously sends or circulates a cooling medium (gas or liquid) (not shown) through a pipe, passage, or the like along the feed pass width direction Wd of the workpiece 9 to the support 58a. In this cooling section 58, the part that comes into contact with the inner surface of the conveyor belt 57a functions as the main cooling section. The support 58a is a member having an elongated shape along the feed width direction Wd and having a size longer than the maximum width size W1 of the workpiece 9. The cooling body 58b is a cooling section that is provided linearly along the longitudinal direction of the support 58a (the direction along the pass width direction Wd of the recording sheet 9A) and in a parallel state spaced apart from each other in the pass width direction Wd of the workpiece 9. The cooling body 58b is also connected to a device (not shown) that generates and sends a cooling medium.

[0103] In this cooling device 5B, the workpiece 9 is cooled as it passes through the cooling section 58 while being conveyed by the conveyor belt 57a of the conveyor device 57. At this time, the workpiece 9 passes through the cooling section 58 while being pressed against the cooling section 58 by the pressing rotor 59.

[0104] In this cooling device 5B, when workpieces 9 having a width size W (intermediate width size W2) smaller than the maximum width size W1 are continuously passed through and cooled, a non-passage area E2, which is an area where the workpieces 9 do not pass through, is generated in the cooling section 58. For this reason, in the cooling section 58, the part corresponding to the pass area E1 through which the workpieces 9 pass absorbs heat by cooling during heat treatment and the temperature rises, whereas the part corresponding to the non-passage area E2 of the workpieces 9 does not absorb heat by cooling during heat treatment and tends to be in a low temperature state. In this case, the portion of the cooling section 58 corresponding to the passing region E1 becomes relatively hot, while the portion corresponding to the non-passing region E2 becomes locally cold, causing a temperature difference throughout the cooling section 58. As a result, uneven cooling may be induced when the workpiece 9 having a large width size W (W1) is subsequently passed through and cooled.

[0105] That is, in the cooling device 5B, when the above-mentioned cooling heat treatment is performed, the cooling section 58, which is the heat treatment section 5j, enters a state in which an unnecessary temperature difference occurs between a portion corresponding to the pass region E1 of the workpiece 9 and a portion corresponding to the non-pass region E2 of the workpiece 9, as shown in Fig. 12(B). At this time, the portion of the cooling section 58 corresponding to the pass region E1 of the workpiece 9 rises in temperature and becomes a high-temperature portion that is a cause of the temperature difference, while the portion of the cooling section 58 corresponding to the non-pass region E2 becomes a low-temperature portion that is a cause of the temperature difference, being relatively lower in temperature than the portion (high-temperature portion) corresponding to the pass region E1.

[0106] Therefore, also in this cooling device 5B, from the viewpoint of suppressing an unnecessary temperature difference occurring between a portion (high temperature portion) of the cooling section 58 corresponding to the pass area E1 of the workpiece 9 and a portion (low temperature portion) corresponding to the non-pass area E2 of the workpiece 9, two heat pipes 1A, 1B are arranged in contact with the surface (back surface) of the cooling section 58 opposite to the surface contacting the conveyor belt 57a, as shown in Fig. 12. Here, the high temperature portion is a portion that generates a temperature at least high enough to vaporize the working fluid 12 sealed in the heat pipes 1A, 1B, for example, a portion that reaches a temperature of 100°C or higher.

[0107] The heat pipe 1 having the configuration according to the first embodiment is applied to both the heat pipes 1A and 1B. In the cooling device 5B, the heat pipes 1A and 1B are arranged so as to be in contact with at least a portion of the cooling section 58 in the heat treatment section 5j that corresponds to a passing area E1 through which the workpiece 9 having the maximum width size W1 passes, as shown in Fig. 12(B). In the heat pipes 1A and 1B at this time, the second liquid transfer section 16 is also arranged in a non-contact state with both the inner wall surface 10c of the tube 10 and the first liquid transfer section 15.

[0108] In the cooling device 5B in which these heat pipes 1A, 1B are arranged, even if a portion corresponding to the non-passage area E2 of the workpiece 9 occurs in the cooling section 58 with which the workpiece 9 comes into contact (via the conveying belt 57a) and a temperature difference occurs, the heat of the portion corresponding to the pass-through area E1 of the cooling section 58 is transferred and heat exchanged by the heat transfer action of the heat pipes 1A, 1B to the portion corresponding to the non-passage area E2 of the workpiece 9 (low temperature portion), which has a relatively lower temperature than the portion corresponding to the pass-through area E1 (high temperature portion).

[0109] As a result, in the cooling device 5B, compared to a case in which the heat pipes 1A, 1B are not arranged, the temperature in the passing area E1 is prevented from increasing when a portion of the workpiece 9 that corresponds to the non-passing area E2 occurs, and unnecessary temperature differences occurring in the cooling section 58 are suppressed. In addition, in the cooling device 5B, even if the cross-sectional area S1 of the tube 10 in the short direction Sd is reduced, the thermal conductivity performance in the longitudinal direction Ld of the heat pipes 1A, 1B is improved, and the occurrence of uneven cooling due to unnecessary temperature differences is suppressed.

[0110] Another example of the heat treatment device 5 may be a drying device including a heat treatment section 5h that performs heat treatment to dry the workpiece 9, and a heat conduction tube 1 such as a heat pipe that is disposed in a portion of the heat treatment section 5h where a temperature difference occurring in the passage width direction Wd of the workpiece 9 should be suppressed. The heat treatment for drying in this case is a heat treatment for heating.

[0111] Furthermore, the heat transfer pipe 1 represented by the heat pipe arranged in the heat treatment device 5 may be the heat transfer pipe 1 (FIG. 4) having the configuration shown in the modified example of the first embodiment. The number of heat transfer pipes 1 arranged in the heat treatment device 5 is not limited to two, and may be one, or three or more. The transport device 57 arranged in the heat treatment device 5 may be a transport device using a transport method other than the belt transport method.

[0112] In the second embodiment, the image forming apparatus 7A including the image forming device 2A and the heating device 5A is exemplified as the processing system 7, but the processing system 7 may have a different configuration.

[0113] 13(A), another example of the processing system 7 may be a processing system including a powder coating device, a printing device, another image forming device, etc., which employs a processing device 2 that performs another process such as powder coating, printing, or image formation by another image forming method on a workpiece 9 as another processing device 2 that performs another process other than heat treatment. In this case, as the heat processing device 5, a suitable device such as the heating device 5A, the cooling device 5B, or the drying device described above is used. In addition, the processing system 7 can also be applied to a device in which the processing device 2 performs processing other than heat exchange in the heat treatment device 5 on the workpiece 9 after it has passed through the heat treatment device 5, as shown in Figure 13 (B). [Explanation of symbols]

[0114] 1. Heat pipe (an example of a heat transfer tube) 2 … Another processing device 2A... Imaging device (an example of another processing device) 5. Heat treatment equipment 5A…Heating device (an example of a heat treatment device) 5B: Cooling device (an example of a heat treatment device) 5h, 5j…Heat treatment section 7. Processing system 7A: Image forming apparatus (an example of a processing system) 10...Pipe (an example of a pipe) 10c…Inner wall surface 12...Hydraulic fluid 15...First liquid transfer section 16...Second liquid transfer section Ld…Longitudinal direction

Claims

1. a tube having a circular cross section, both ends of which are closed, and an outer diameter of 3 mm or less; A working fluid that is sealed inside the tube and vaporizes and liquefies; a liquid transfer section that transfers the liquefied working liquid present along the longitudinal direction inside the pipe at least in the longitudinal direction; Equipped with the liquid transfer section has a first liquid transfer section that contacts the entire area of ​​the inner wall surface of the tube when viewed in a cross section perpendicular to the longitudinal direction of the tube, and a second liquid transfer section that is not in contact with the inner wall surface of the tube and the first liquid transfer section; the first liquid transport portion is made of a mesh-like material made of metal wires, The second liquid transport portion is a heat transfer tube composed only of a linear material obtained by twisting metal wires together and bundling them into a shape with no circular space in the entire cross section.

2. a tube having a circular cross section, both ends of which are closed, and an outer diameter of 3 mm or less; A working fluid that is sealed inside the tube and vaporizes and liquefies; a liquid transfer section that transfers the liquefied working liquid present along the longitudinal direction inside the pipe at least in the longitudinal direction; Equipped with the liquid transfer section has a first liquid transfer section that contacts a portion of an inner wall surface of the tube when viewed in a cross section perpendicular to the longitudinal direction of the tube, and a second liquid transfer section that is not in contact with the inner wall surface of the tube and the first liquid transfer section; the first liquid transport portion is made of a mesh-like material made of metal wires, The second liquid transport portion is a heat transfer tube composed only of a linear material obtained by twisting metal wires together and bundling them into a shape with no circular space in the entire cross section.

3. A heat treatment section that exchanges heat with a workpiece passing through the heat treatment section in contact with the workpiece; A heat conduction pipe is installed across a portion of the heat treatment section corresponding to a passing region through which the workpiece passes and a portion corresponding to a non-passing region through which the workpiece does not pass; Equipped with 3. A heat treatment apparatus using the heat conduction tube according to claim 1 or 2 as the heat conduction tube.

4. A heat treatment device as described in claim 3, wherein the first liquid transfer section in the heat transfer tube is in contact with a range including a portion of the inner wall surface of the tube that is to come into contact with a high-temperature section that should absorb heat during heat exchange in the heat treatment section.

5. A heat treatment device having a heat treatment section that exchanges heat with a workpiece passing through the heat treatment section in contact with the workpiece; Another treatment device that performs a treatment other than the heat exchange on the object to be treated before or after passing through the heat treatment device; Equipped with 5. A processing system comprising the heat treatment apparatus according to claim 3.

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