Heating device and heated body utilization device

Abstract

To provide a heating device and the like that, in comparison with a case where a power supply connection part is arranged on one end part side where a caulking part of a heat pipe is present, can suppress occurrence of a short circuit in the power supply connection part caused by steam when the steam leaks from the caulking part of the heat pipe.SOLUTION: A heating device 5 comprises: heating means 54 that contacts with a heated body to be conveyed in a contact part to heat the heated body; a heat pipe 7 that is arranged along a width direction D going across a conveyance direction of the heated body in a part of the heating means 54 different from the contact part, and has a caulking part 73 in one end part 71; and a power supply connection part 64 that is arranged on other end part 72 side of the heat pipe 7, and connects to wiring for supplying power to the heating means 54.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a heating device and an apparatus for utilizing a heated object. [Background technology]

[0002] BACKGROUND ART Conventionally, heating devices in which a heat pipe is arranged are known, for example, as those described in Patent Documents 1 and 2 below.

[0003] Patent Document 1 describes a heating device that has a heating means, an endless film member that is arranged to be freely movable while sliding against the heating means, a pressure means that is arranged so as to be in pressure contact with the heating means via the film member, a heat-equalizing member such as a heat pipe that is arranged so as to be in pressure contact with the pressure means via the film member on the downstream side of the heating means in the direction of movement of the film member, a temperature detection means that detects the temperature of the heating means, and an energy control means that controls the energy supplied to the heating means, and that passes the material to be heated through the pressure contact area obtained by pressing the heating means and the heat-equalizing member against the pressure means via the film member, and applies thermal energy from the heating means to the material to be heated via the film member.

[0004] Patent document 2 describes a heating means in which a heating element is printed on a substrate made of a plate-shaped heat pipe via an insulating layer, and the top surface of the heat pipe is further coated with an insulating layer, at least one surface of the heat pipe is concave, and a heating element is printed on the surface opposite the concave surface via an insulating layer, and the top surface is further coated with an insulating layer. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2004-235001 A (Claim 2, Figures 1, 4, etc.) [Patent Document 2] JP 2013-142834 A (Claim 3, Figure 3, etc.) Summary of the Invention [Problem to be solved by the invention]

[0006] This invention provides a heating device and a heated object utilization device that can suppress the occurrence of a short circuit at the power supply connection part due to steam leaking from one end of the body of the heat conduction member, compared to when the power supply connection part is located only at one end side in the longitudinal direction of the body of the heat conduction member, where the thickness is thinner or the strength is weaker than the other parts. [Means for solving the problem]

[0007] The heating device of this invention (1) is a heating means for contacting the transported object to be heated at a contact portion and heating the object; a heating means that is disposed in a portion of the heating means different from the contact portion along a direction intersecting the conveying direction of the object to be heated, has a capillary structure therein, and has one end in the longitudinal direction along the intersecting direction; The end portion to which the a heat conduction member including a main body having a wall thickness thinner than that of the remaining portion, and a volatile working fluid sealed inside the main body; a power supply connection portion disposed only on the other end side of the main body in the longitudinal direction of the heat conduction member and connected to wiring that supplies power to the heating means; It is equipped with the following. In addition, the heating device of this invention (2) is a heating means for contacting the transported object to be heated at a contact portion and heating the object; a heating means that is disposed in a portion of the heating means different from the contact portion along a direction intersecting the conveying direction of the object to be heated, has a capillary structure therein, and has one end in the longitudinal direction along the intersecting direction; The end portion to which the a heat conduction member including a main body having a strength weaker than that of other parts, and a volatile working fluid sealed inside the main body; a power supply connection portion disposed only on the other end side of the main body in the longitudinal direction of the heat conduction member and connected to wiring that supplies power to the heating means; It is equipped with the following.

[0008] The heating device of the present invention (3) is the heating device of the above invention (1) or (2), wherein a hygroscopic member is provided in contact with or close to the one end of the main body. The heating device of this invention (4) is a heating device according to any one of the above inventions (1) to (3), in which the heating means heats the heated object being transported so as to pass from below to above, and the power supply connection part is arranged at a position corresponding to the upper end of the heating means.

[0009] In addition, the heated object utilization device of this invention (5) is a conveying means for conveying the object to be heated; a heating device that heats the object to be heated that is transported by the transport means; Equipped with The heating device is configured as any one of the heating devices according to the above inventions (1) to (4). [Effects of the Invention]

[0010] According to the heating device of the above inventions (1) and (2), the power supply connection part is Joined The thickness of the heat conducting member at one end is thinner than that of the other portion, or the strength of the heat conducting member is weaker than that of the other portion. Joined When steam leaks from one end, it is possible to prevent a short circuit from occurring at the power supply connection portion due to the steam.

[0011] According to the above invention (3), steam leaking from one end of the main body can be temporarily collected. According to the above invention (4), even if steam leaking from one end of the main body diffuses and moves to the side where the power supply connection is located and condenses, there is no risk of the droplets remaining on the power supply connection, compared to when the power supply connection is located at a position corresponding to the lower end of the heating means.

[0012] According to the heated object utilization device of the above invention (5), when steam leaks from one end of the main body of the heat conduction member in the heating device, it is possible to prevent a short circuit from occurring at the power supply connection part due to the steam, and the heated object can be utilized while being stably heated. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic diagram illustrating an image forming apparatus according to a first embodiment. [Figure 2] 1 is a schematic partial cross-sectional view showing a heating device according to a first embodiment. [Figure 3] FIG. 3 is a schematic diagram showing the heating device of FIG. 2. [Figure 4] 3(A) is a schematic cross-sectional view showing a part of a heating unit applied to the heating device of FIG. 2, and FIG. 3(B) is an exploded view of the heating unit of FIG. [Figure 5] FIG. 3 is a schematic diagram showing a part of the heating device of FIG. 2. [Figure 6] (A) is a schematic diagram showing a part of the heating unit, and (B) is a schematic diagram showing the heat pipe. [Figure 7] FIG. 10 is a schematic diagram showing a main part of a modified example of the heating device. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0015] Embodiment 1 1 and 2 show a configuration example of a first embodiment of the present invention. Fig. 1 shows an image forming apparatus 1 according to the first embodiment, and Fig. 2 shows a heating device 5 according to the first embodiment. The arrows indicated by the symbols X, Y, and Z in each drawing, such as Figure 1 and Figure 2, indicate the left-right direction (horizontal direction), the up-down direction (vertical direction), and the front-back direction (horizontal direction), respectively. Also, the circle at the point where the arrows of the X and Y directions intersect in the drawing indicates that the Z direction points vertically downward in the drawing.

[0016] <Image forming device> 1 is an apparatus for forming an image by forming an image made of a developer, which is an example of a powder, on a sheet of paper 9, which is an example of a heated object, and then heating the sheet. This image forming apparatus 1 also corresponds to an example of a heated object utilizing apparatus that utilizes a heated object.

[0017] 1, the image forming apparatus 1 according to the first embodiment has a housing 10 having a required external shape, and is configured by arranging an image forming device 2, a paper feeder 4, a heating device 5, etc. in the internal space of the housing 10. The dashed dotted lines in FIG. 1 indicate the main transport paths along which paper 9 is transported within the housing 10.

[0018] The image forming device 2 is a device that forms a toner image made of toner as a developer and transfers it onto paper 9. This image forming device 2 has a photosensitive drum 21 that rotates in the direction indicated by 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.

[0019] Of these, the photosensitive drum 21 is an example of an image carrying means, and is a photosensitive member in the form of a drum having an image forming surface and a photosensitive layer that serves as the image carrying 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 with 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 to which a charging current is supplied.

[0020] 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. This exposure device 23 operates by receiving an image signal that is generated by performing required processing on image information input from the outside using an image processing means (not shown) or the like. The image information is information related to the image to be formed, such as characters, figures, photographs, and patterns. 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 monochrome toner image.

[0021] 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 onto the paper 9. 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 unwanted toner, paper dust, and other unwanted matter adhering to the outer peripheral surface of the photosensitive drum 21. In the image forming device 2, the position where the photosensitive drum 21 and the transfer device 25 face each other is the transfer position TP where the toner image is transferred.

[0022] The paper feeder 4 is a device that stores and sends out paper 9 to be supplied to the transfer position TP in the image forming device 2. This paper feeder 4 is configured by arranging devices such as one or more containers 41 that store paper 9 and one or more feeders 43 that feed out paper 9. Container 41 is a container member having a stacking plate (not shown) that stores multiple sheets of paper 9 stacked in a required orientation. Feed device 43 is a device that uses multiple rolls or other devices to pay out the paper 9 loaded on the stacking plate of container 41 one sheet at a time. Paper feed device 4 in embodiment 1 has two containers 41A and 41B that can individually store, for example, paper sheets 9A and 9B that have different widths during transport, and two feed devices 43A and 43B that individually feed out the paper sheets 9A and 9B stored in containers 41A and 41B, respectively.

[0023] The paper feed device 4 is connected to the transfer position TP in the image forming device 2 by a paper feed conveying path 45, which is an example of a conveying means. This paper feed conveying path 45 is a paper conveying path that conveys and supplies the paper 9 (9A or 9B) sent out from the paper feed device 4 to the transfer position TP, and is configured by arranging a plurality of conveying rolls 46a, 46b that clamp and convey the paper 9, and a plurality of guide members (not shown) that ensure a conveying space for the paper 9 and guide the conveyance of the paper 9, etc. The paper 9 may be any sheet-like recording medium that can be transported within the housing 10 and onto which a toner image can be transferred and thermally fixed, and there are no particular restrictions on the material, shape, etc. of the paper 9.

[0024] The heating device 5 is a device that applies heat and pressure to fix the unfixed toner image transferred at the transfer position TP of the image forming device 2 onto the paper 9. The heating device 5 is configured by arranging devices such as a heating rotor 51 and a pressure rotor 52 in the internal space of a housing 50 that is provided with an inlet 50a and an outlet 50b for the paper 9. In addition, in the heating device 5, as shown in Figures 1 and 2, the heating rotor 51 and the pressure rotor 52 are arranged to rotate in contact with each other, and the paper 9 etc. passing through at the contact point FN is heated and pressurized. The heating device 5 will be described in detail later.

[0025] In this image forming apparatus 1, an image is formed, for example, as follows.

[0026] That is, in the image forming device 1, when a control means (not shown) receives a command to form an image, the image forming device 2 performs charging, exposure, development and transfer operations, while the paper feed device 4 performs a paper feed operation in which the required paper 9 (9A or 9B) is sent out and transported to the transfer position TP via the paper feed conveying path 45 and supplied. As a result, a toner image corresponding to the image information is formed on the photosensitive drum 21, and the toner image is transferred onto the paper 9 supplied to the transfer position TP from the paper feeder 4. At this time, the paper 9 onto which the toner image has been transferred is separated from the photosensitive drum 21 while being sandwiched between the rotating photosensitive drum 21 and the transfer device 25, and is sent towards the heating device 5.

[0027] Next, in the image forming apparatus 1, the heating device 5 performs a fixing operation in which the paper 9 onto which the toner image 92 has been transferred is heated and pressurized as it is introduced into and passes through the contact area FN, as shown in FIG. After fixing, the paper 9 is ejected from the housing 50 while sandwiched between the heating rotor 51 and the pressure rotor 52 in the heating device 5, and then transported to the paper ejection port 12 via the paper ejection transport path, and finally sent by the ejection rolls 48 to the ejection paper storage section 13 provided in part of the housing 10 and stored therein. At this time, the heating rotor 51 and the pressure rotor 52 function as a transport means for transporting the paper 9.

[0028] With the above, the basic image forming operation of the image forming apparatus 1 for forming a monochrome image on one side of one sheet of paper 9 is completed.

[0029] <Heating device> Next, the heating device 5 will be described in detail.

[0030] As shown in Figures 2, 3, etc., the heating device 5 of embodiment 1 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 generates heat by pressing the heating belt 53 from its inner surface against the pressure rotor 52 to form a contact part (nip) FN and heat the heating belt 53, and uses a roll-type pressure roller 56 as the pressure rotor 52.

[0031] Of these, the heating unit 55 heats the paper 9 at a portion FN (an example of a contact portion) that contacts the paper 9 in a width direction D (FIG. 3, etc.) that intersects with the conveyance direction C of the paper 9. This 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. In addition, the heating unit 55 supports the contact holder 61 and the left and right end holders 62A, 62B by a support 63.

[0032] The heating belt 53 is an endless heat-conducting belt that is flexible and heat-resistant. The heating belt 53 is made of a material such as a synthetic resin, such as polyimide or polyamide, and is formed into a cylindrical shape.

[0033] The heating element 54 is composed of a substrate 541, multiple (three in this example) heating portions 542A, 542B, and 542C provided on one surface 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, and 542C.

[0034] The substrate 541 is a rectangular plate-like member having a width W in a width direction D intersecting with the conveyance direction C of the paper 9 that is longer than the maximum size W1. The substrate 541 is made of an electrically insulating material, and for example, a ceramic substrate is used. One surface 541a of the substrate 541 that comes into contact with the inner circumferential surface of the heating belt 53 is covered with a coating layer formed after the heat generating portions 542A, 542B, and 542C are provided.

[0035] As shown in Figure 6(A), the heat generating portions 542A, 542B, and 542C are heating wire portions that are arranged in a straight line on one side 541a of the substrate 541 along its longitudinal direction (the direction along the width direction D of the paper 9) and are parallel to and spaced apart from each other in the width direction D of the paper 9. FIG. 6(A) is a drawing showing a state as viewed from the back surface (the other surface) 541b of one surface 541a of the substrate 541 of the heating element 54. Therefore, in reality, the heating part 542 provided on the side of the one surface 451a cannot be seen or appear. However, in FIG. 6(A), for the convenience of explaining the heating part 542, the heating part 542 is depicted in a state where it can be seen through from the other surface 541b.

[0036] Further, these heating parts 542A, 542B, 542C have the same length with respect to the longitudinal direction of the substrate 541, but are configured such that regions that generate relatively more heat are present at different positions so as to conform to the difference in the width size W during the conveyance of the sheet 9. That is, the first heating part 542A is configured such that a central part excluding the end parts on both ends in the longitudinal direction becomes a region that generates relatively more heat. This first heating part 542A is used when the sheet 9 with a width size W of the intermediate size W2 (<W1) passes through. Also, the second heating part 542B is configured such that a part corresponding to the end parts on both ends of the first heating part 542A becomes a region that generates relatively more heat. Furthermore, the third heating part 542C is configured such that a central part in the longitudinal direction (for example, a part about 1 / 3 of the total length) becomes a region that generates relatively more heat. This third heating part 542C is used when the sheet 9 with a width size W of the minimum size W3 (<W2) passes through.

[0037] Incidentally, the configuration of the regions that generate relatively more heat of the heating parts 542A, 542B, 542C in the first embodiment is such that the central position in the width direction D during the conveyance of the sheet 9 guides and conveys the sheet so as to pass through the central position that is the reference for the passing region width of the sheet 9 at the contact part FN of the heating device 5. This is the case when adopting the center reference conveyance method (center registration method). Also, for the regions that generate relatively more heat of these heating parts 542A, 542B, 542C, for example, at least one of the width and thickness of the heating wire part is made narrower or thinner or both than the other parts (parts for suppressing heat generation) so that the electrical resistance value becomes relatively higher. Furthermore, the temperature in the heating element 54 due to the heat generated by the heating portions 542A, 542B, and 542C is measured by a temperature sensor (not shown) that is arranged to contact a required location on the back 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).

[0038] 6(A) and other figures, wiring section 543 is provided so that its wire concentration portion is located at one end in the longitudinal direction of heating element 54 and outside one of end holders 62A, 62B. Wiring section 543 in the first embodiment is configured as an end portion obtained by extending one end of substrate 541 to the outside of right end holder 62B. In addition, this wiring section 543 is composed of an electrically insulating substrate 543a, individual wiring sections 543b, 543c, and 543d that are individually connected to one end of each of the heat generating sections 542A, 542B, and 542C as shown by dashed lines in Figure 6(A), and a common wiring section 543e that is commonly connected to the other end of each of the heat generating sections 542A, 542B, and 542C as shown by the dotted area and dashed lines in Figure 6(A).

[0039] 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.

[0040] The power supply connection section 64 in embodiment 1 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 in an exposed state and connected to the connection ends of each wiring of the wiring section 543. This power supply connector 64 is connected to the power supply connector 14 that extends from a power supply unit (not shown) in the image forming apparatus 1 as shown in FIG. 6(A), for example, and is in a state where it can be energized.

[0041] Furthermore, this power supply connection portion 64 is arranged at a position where it can be connected to the connection end portions of each wire in the wiring portion 543, and is arranged so as to be located outside one of the left and right end holders 62A, 62B. In the first embodiment, as shown in Figures 3, 5, 6, etc., the power supply connection portion 64 is located outside the right end holder 62B, and is provided at, for example, one end of the wiring portion 543 of the heating element 54 or one end of the contact holder 61. 5 and 6(A), the power supply connection part 64 heats the paper 9 or the like that is transported so that the heating unit 55 passes from below to above as shown in the transport direction C, and therefore is disposed at a position corresponding to the upper end of the heating unit 55. Specifically, the power supply connection part 64 is disposed so as to be present at the end of the wiring part 543 of the heating element 54 or the contact holder 61 on the downstream side (corresponding to the upper side) in the transport direction C.

[0042] The contact holder 61 is a plate-like member that is long in one direction and has a recessed portion 61 a for receiving and holding the heating element 54 on one side of the contact holder 61 that comes into contact with the inner circumferential surface of the heating belt 53 . The contact holder 61 is provided on one side thereof with an attachment groove 61b and an attachment contact portion 61c, which are used when attaching the contact holder 61 to the support body 63, on the other side opposite to the one side thereof. Furthermore, one long side end of the contact holder 61 on one side where 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 the direction of exiting from the contact portion FN.

[0043] Each of the left and right end holders 62A, 62B is a member having curved belt guide holders 622 provided on the inner surface of a disk-shaped main body 621, which is partially missing the portion facing the pressure roll 56. The curved belt guide holders 622 guide and hold both widthwise ends of the heating belt 53 so that they can rotate from the inner peripheral surface. Each of the left and right end holders 62A, 62B has 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.

[0044] As shown in Fig. 3 etc., the support 63 is a member that is longer than the longitudinal length of the heat generating element 54. As shown in Fig. 4(A) etc., for example, the support 63 may be a member in the form of a flat plate that is long in one direction and has the long side end bent at a substantially right angle in the same direction so that the cross section has a concave shape. 4(B), one bent end 63b of the support body 63 is fitted into the mounting groove 61b of the contact holder 61, while the other bent end 63c is kept in contact with the mounting contact portion 61c of the contact holder 61. In this way, the support body 63 supports a part of the contact holder 61 by sandwiching it in the longitudinal direction.

[0045] The heating unit 55 is assembled, for example, as follows. First, the contact holder 61 with the heating element 54 attached is attached to the bent ends 63b, 63c of the support 63 and inserted into the heating belt 53, and then the left and right end holders 62A, 62B are attached to the support 63 at positions slightly inside both longitudinal ends so as to sandwich the heating belt 53 from both ends. At this time, the left and right end holders 62A, 62B are attached so as to be located at or outside the ends of the heating part 542 of the heating element 54, as shown in Fig. 6(A). This completes the assembly of the heating unit 55. The heating unit 55 is disposed in the heating device 5 by attaching and fixing both longitudinal end portions 63d, 63e of the support body 63 to attachment portions (not shown) provided on the inner wall surface of the housing 50.

[0046] 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 surface of which an elastic layer and a release layer are provided. As shown in Fig. 3, 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 is also subjected to pressure from the pressure mechanism to press it against the heating unit 55. As a result, the outer circumferential surface of the pressure roll 56 is kept in a state in which it is pressed against one surface 541a of the heating element 54 with a required pressure across the longitudinal direction via the heating belt 53 of the heating unit 55, as shown in Figs. The portion where the pressure roll 56 comes into pressure contact with the heating unit 55 is the contact portion FN.

[0047] 3, a powered passive gear 57 is attached to one shaft portion 56c of the pressure roll 56, and the powered passive gear 57 meshes with a powered passive gear (not shown) in the drive transmission device 15 arranged on the housing 10 side of the image forming apparatus 1. As a result, when the time comes for an image forming operation or the like, the pressure roll 56 receives a rotational force transmitted from the drive transmission device 15 and is driven to rotate at a required speed in the direction indicated by arrow B1, as shown in FIG. When the pressure roll 56 rotates and is driven, the heating belt 53 in the heating unit 55 rotates accordingly in the direction indicated by the arrow B2, as shown in FIG.

[0048] The heating device 5 is configured so that when an image forming operation is performed, the heat generating area of the heating element 54 of the heating unit 55 is adjusted according to the difference in the width size W of the paper 9 passing through the contact portion FN.

[0049] For example, when passing a sheet of paper 9 whose width W during transport is the maximum size W1, power is supplied to both the first heating element 542A and the second heating element 542B to heat the area corresponding to the maximum size W1. When passing a sheet of paper 9 whose width W is the minimum size W3, power is supplied only to the third heating element 542C to heat the area corresponding to the minimum size W3. Furthermore, when passing a sheet of paper whose width W2 is medium, power is supplied only to the first heating element 542A to heat the area corresponding to the medium size W2. This allows the heating device 5 to efficiently generate heat by adjusting the heating element 54 of the heating unit 55 to the difference in width W of the paper 9 .

[0050] However, even in this heating device 5, when paper sheets 9 having a width size W (including intermediate size W2 and minimum size W3) smaller than the maximum size W1 are passed through continuously to be heated, a so-called non-paper passing area is created in the contact portion FN where the paper sheets 9 do not pass, and the non-paper passing area continues to be heated by the suppressed heat generation portion of the heat generating section 542 without heat being taken away by the paper sheets 9 passing through, resulting in an elevated temperature. In this case, the non-paper passing area of the contact portion FN becomes locally hot, which may result in the contact holder 61 being locally heated and adversely affected, or may induce uneven heating.

[0051] Therefore, in the heating device 5, in order to suppress unnecessary temperature increases in non-paper passing areas, as shown in Figures 2 to 4, two heat pipes 7A and 7B are arranged in contact with the surface (back surface) 541b opposite to the surface 541a of the heating element 54 in the heating unit 55 that contacts the heating belt 53. Here, the surface 541a of the heating element 54 that comes into contact with the heating belt 53 is also the portion that corresponds to the contact portion when it comes into contact with and heats the paper 9. The opposite surface (back surface) 541b of the heating element 54 is an example of a portion that is different from the contact portion when it comes into contact with and heats the paper 9.

[0052] Both heat pipes 7A and 7B are sealed tubes with both ends closed, made of a material with excellent thermal conductivity such as copper or stainless steel, and have a main body 70 with an inner wall having a capillary structure (a so-called wick), and a volatile working fluid (such as pure water) is sealed inside the main body 70. 5 and other figures, the heat pipes 7A, 7B have approximately the same length as the heat generating portion 542 of the heat generating element 54. Furthermore, since the two heat pipes 7A, 7B are used in parallel arrangement, heat pipes with a relatively small diameter (for example, an outer diameter of several millimeters) are used.

[0053] The heat pipes 7A and 7B are arranged along the longitudinal direction (along the width direction D of the paper 9) of the rear surface 541b of the heat generating element 54, and are arranged parallel to each other with a required gap in the conveyance direction C of the paper 9. 4 and other figures, in the first embodiment, mounting grooves 65A and 65B for the heat pipes 7A and 7B are provided in the accommodating recess 61a of the contact holder 61, and the heat pipes 7A and 7B are mounted in the mounting grooves 65A and 65B, respectively, and then the heating element 54 is accommodated in the accommodating recess 61a, with the back surface 541b of the heating element 54 pressing against the heat pipes 7A and 7B. The heat pipes 7A and 7B may be partially adhered and fixed to the back surface 541b of the heating element 54 with a thermally conductive adhesive.

[0054] In the heating device 5 in which the heat pipes 7A and 7B are arranged, even if a non-paper passing area occurs at the contact part FN and the temperature rises, the heat in the area corresponding to the non-paper passing area of the heating element 54 is transferred to the paper passing area where the paper 9 of the heating element 54 passes and the temperature becomes relatively lower than that of the non-paper passing area due to the heat transfer action of the heat pipes 7A and 7B.

[0055] As a result, in the heating device 5, the temperature rise in the non-sheet passing areas is suppressed compared to when the heat pipes 7A and 7B are not provided. Furthermore, in this heating device 5, two heat pipes 7A, 7B are arranged parallel to and spaced apart in the conveying direction C of the paper 9 at the heating element 54, so that, compared to when a single heat pipe 7 is arranged, the temperature rise is evenly and efficiently suppressed both before and after the conveying direction C of the paper 9 in the non-paper passing area.

[0056] Furthermore, the heat pipes 7A and 7B used in this heating device 5 have a crimped portion 73 at one end 71 of the main body 70, as shown in FIG. 6(B). The crimped portion 73 is a portion obtained after processing to close the cylindrical end portion by crushing and joining the end portion in a vacuum, and is a portion that is thinner and weaker than the main body 70. The external shape of the crimped portion 73 is not particularly limited. The other end portion 72 of the main body 70 has an end shape that is closed by joining processing such as welding.

[0057] On the other hand, heat pipes 7A and 7B are subjected to thermal stress from heating element 54 and vapor pressure generated when the working fluid evaporates during the fixing operation of heating device 5. Furthermore, during the fixing operation of heating device 5, the temperature of the non-paper passing area of heating element 54 often reaches a high temperature of around 200°C and is transferred to heat pipe 7, creating an environment susceptible to the effects of thermal stress and vapor pressure. Therefore, in the case of heat pipes 7A and 7B having a crimped portion 73 at one end 71 of the main body 70, if the crimped portion 73 continues to be subjected to such stresses of heat and vapor pressure, there is a risk that vapor of the working fluid (such as water vapor) will leak from the crimped portion 73. There is also a concern that stress will be concentrated on the crimped portion 73 due to repeated heating and cooling of the main body 70, making the crimped portion 73 more susceptible to damage, including deformation that loosens the joint.

[0058] 2, 3, 5, etc., in the heating device 5, the power supply connection portion 64 is disposed on the other end portion 72 side of the main body 70 of the heat pipes 7A, 7B in the longitudinal direction. In other words, the heat pipes 7A, 7B are disposed so that the one end portion 71 with the crimped portion 73 is located on the opposite side of the power supply connection portion 64 in the longitudinal direction of the heating element 54.

[0059] In this case, the heat pipes 7A, 7B are accommodated and attached in the accommodation recess 61a of the contact holder 61 while paying attention to the position of the crimped portion 73. In addition, at this time, the heat pipes 7A, 7B are arranged with their longitudinal ends sandwiched closely between the inner surfaces of the left and right end holders 62A, 62B, as shown in Figures 3 and 5.

[0060] Therefore, in this heating device 5, even if steam leaks from the crimped portions 73 of the heat pipes 7A and 7B, the occurrence of a short circuit at the power supply connection portion 64 due to steam leaking from the crimped portions 73 of the heat pipes 7A and 7B is suppressed compared to a case in which the heat pipes 7A and 7B are not positioned so that the crimped portions 73 are on the opposite side of the power supply connection portion 64.

[0061] Furthermore, in this heating device 5, as shown in Figure 5 etc., the power supply connection part 64 is arranged at a position corresponding to the end part on the upper side of the heating unit 55 (downstream side in the conveying direction C in which the paper 9 is conveyed so as to pass from below to above). Therefore, compared to when the power supply connection part 64 is arranged at a position corresponding to the end part on the lower side of the heating unit 55, even if steam leaking from the crimping part 73 diffuses within the heating unit 55 or the housing 50 and moves to the side where the power supply connection part 64 is located and condenses, there is no risk of the liquid droplets dripping down and remaining on the power supply connection part 64. This also ensures that the heating device 5 can reliably prevent the occurrence of the short circuit at the power supply connection part 64.

[0062] Variant. In the heating device 5 according to the first embodiment, as illustrated in FIG. 7, a hygroscopic member 75 may be provided around one end 71 of the main body 70 having the crimped portions 73 of the heat pipes 7A and 7B. This hygroscopic member 75 may be any heat-resistant member capable of absorbing the vapor of the working fluid sealed in the heat pipes 7A and 7B. Furthermore, this member 75 may be disposed in contact with or close to one end 71 of the main body 70 having the crimped portion 73, but may be disposed out of contact with the back surface 541b of the heating element 54.

[0063] The heating device 5 according to embodiment 1 is an example of a configuration in which a heating unit 55, which is an example of a heating rotor 51, and a pressure roll 56, which is an example of a pressure rotor 52, are arranged side by side in a substantially horizontal direction and rotate in contact with each other, but this is not limited to this. That is, the heating device 5 may be configured, for example, so that the heating unit 55 and the pressure roll 56 are arranged vertically (in the direction of gravity) and in contact with each other while rotating, or the heating unit 55 and the pressure roll 56 are arranged diagonally in a direction that is inclined, and in contact with each other while rotating. Furthermore, the pressurizing rotor 52 is not limited to a roll type, and may be, for example, a belt-nip type. The heating device 5 is a so-called heating and pressurizing device that includes the pressurizing rotor 52, but it may not include the pressurizing rotor 52 as long as the object to be heated can be moved so as to come into contact with the heating portion of the heating unit 55 and be heated. Also, the heating unit 55 may also include the heating belt 53 as an example or part of the object to be heated. Furthermore, the heating unit 55 may not include the heating belt 53.

[0064] Furthermore, the number of heat pipes 7 arranged in the heating unit 55 may be one or three or more. The heat pipes 7 are not limited to those having a cylindrical shape, and may be, for example, those having a flat plate shape.

[0065] The power supply connection portion 64 may be disposed at a position outside the left end holder 62A. In this configuration, the heat pipes 7A and 7B are disposed so that their crimped portions 73 are located on the opposite side from the power supply connection portion 64. Furthermore, when it is difficult to secure the space for placement, the power supply connection part 64 may be placed at a position corresponding to the lower end of the heating unit 55 .

[0066] In addition, in the first embodiment, an example in which the heating device 5 is applied to the image forming apparatus 1 is shown, but the present invention is not limited to this. In other words, the heating device 5 can also be applied to devices using other image forming methods, paper drying devices (an example of a device using a heated object) that heat or dry paper 9 transported by a paper transport means, and devices (an example of a device using a heated object) that have a process of heating or drying a sheet-like object (an example of a heated object) on which an image is not formed while transporting it by a transport means. Furthermore, the image forming apparatus 1 may be an apparatus that forms a multi-color image by combining toners of multiple colors, and is not particularly limited in terms of its type. [Explanation of symbols]

[0067] 1...Image forming device (an example of a device using a heated object) 5...Heating device 7...heat pipe 9...Paper (an example of a heated object) 54...heating element (an example of heating means) 64...Power supply connection 70...Main body 71...One end 72...Other end 73...Crimped part 75... Moisture-absorbing materials 541a...the surface of the heating element that comes into contact with the heating belt (an example of a contact portion) C...Transport direction D…Width direction FN: Contacting part (an example of a contact part)

Claims

1. a heating means for contacting the transported object to be heated at a contact portion and heating the object; a heat conduction member including a main body that is disposed in a portion of the heating means different from the contact portion along a direction intersecting the conveyance direction of the heated object, has a capillary structure therein, and has one end joined at a longitudinal direction along the intersecting direction, the end having a thickness thinner than the remaining portion; and a volatile working liquid sealed inside the main body; a power supply connection portion disposed only on the other end side of the main body in the longitudinal direction of the heat conduction member and connected to wiring that supplies power to the heating means; A heating device comprising:

2. a heating means for contacting the transported object to be heated at a contact portion and heating the object; a heat conduction member including a main body that is disposed in a portion of the heating means different from the contact portion along a direction intersecting the transport direction of the heated object, has a capillary structure therein, and has one end joined at a longitudinal direction along the intersecting direction, the strength of the one end being weaker than the remaining portion; and a volatile working liquid sealed inside the main body; a power supply connection portion disposed only on the other end side of the main body in the longitudinal direction of the heat conduction member and connected to wiring that supplies power to the heating means; A heating device comprising:

3. 3. The heating device according to claim 1, wherein a hygroscopic member is provided in contact with or close to the one end of the body.

4. The heating means heats the object to be heated as it is conveyed so as to pass from below to above, 4. The heating device according to claim 1, wherein the power supply connection portion is disposed at a position corresponding to an upper end of the heating means.

5. a conveying means for conveying the object to be heated; a heating device that heats the object to be heated that is transported by the transport means; Equipped with 5. An apparatus for utilizing a heated object, wherein the heating device is configured as the heating device according to claim 1.

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