JP2007086452A - Fixing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing device in which a heat reflection plate is easily fitted, hardly falls even when heated to extend or deform, and effectively prevent heat dissipation from a heat source and then heat dissipation from an exterior cover in cooperation with the exterior cover to reduce power consumption. <P>SOLUTION: The heat reflection plate (4) is engaged and fitted to the exterior cover (5) which is arranged surrounding the outside of the heat reflection plate (4) at intervals (La, Lb) and made of synthetic resin. For example, Ends (41, 42) of the heat reflection plate (4) along the axial direction of a rotary body (2) for heating and a rotary body (3) for pressing are fitted by being hooked to lock parts 53 and 54 provided on the side of the exterior cover (5). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a heat-fixing type fixing device used in an image forming apparatus such as a printer, a copying machine, or a multi-function machine that forms an image made of toner on a sheet using an electrophotographic method, In particular, the present invention relates to an improvement of a fixing device in which measures are taken to prevent heat generated from a heating rotator or the like from being released to the outside of the device.

  In recent years, in the image forming apparatus as described above, there is an increasing demand for an increase in image forming speed, miniaturization of the apparatus, and energy saving (energy saving).

  For this reason, a thermal fixing type fixing device for fixing an unfixed toner image formed by an image forming device to a sheet-like material such as paper is most likely to require high-temperature heating during the image forming process. In order to consume electric power energy, it is said that energy saving (low power consumption) technology that leads to a reduction in environmental load is particularly necessary.

  Further, in such a fixing device, since the fixing process is performed, not only when fixing is performed but also in a standby state, a predetermined heating state is maintained. In order to reduce the size of the fixing device, a cleaning device, a toner cartridge, and the like are arranged in the vicinity of the fixing device. There may be a problem that the toner and the like are adversely affected by heat (such as a phenomenon of fusing and aggregation).

  Conventionally, in order to solve the above problems, as shown below, a heat reflecting plate, a heat insulating material, and the like are disposed around a heating rotating body such as a heating roll to suppress heat radiation from a heating source. A fixing device that enables saving of energy consumption has been proposed.

  For example, there is a fixing device in which heat reflecting means for reflecting heat radiated from a heating roller toward the roller surface is disposed in a non-contact state at a position surrounding the outer peripheral surface of the roller (Patent Document 1). Specific examples of the heat reflecting means include a reflector made of metal shaped so as to surround the outer peripheral surface of the heating roller, or a curved surface portion along the outer peripheral surface of the roller surrounding the heating roller. The thing which gave metal plating is illustrated.

  In addition, a shielding plate surrounding the heating roller, a heat insulating material to be attached to the shielding plate, a cap for closing the side surface of the heating roller, and a frame provided with a heat insulating material for housing the heating roller and the shielding plate are provided. There is a fixing device (Patent Document 2).

JP-A-9-101700 Japanese Patent Laid-Open No. 6-59596

  However, the fixing devices proposed above have the following problems.

  That is, in the fixing device proposed in Patent Document 1, when a heat reflecting plate separate from the frame is installed, the mounting structure of the heat reflecting plate is unknown, for example, bonding, screwing, etc. If this fixing means is applied, a dedicated mounting operation for only the heat reflecting plate is required, and as a result, the assembly operation for the entire fixing device becomes complicated. Also, depending on the mounting method, the heat reflecting plate may be removed due to extension or deformation due to heat, and in the worst case, the removed heat reflecting plate may come into contact with the surface of the heating roller. . Furthermore, since there is an open state between the heat reflecting plate and the frame, heat enters the gap between the heat reflecting plate and the frame to heat the frame, so that heat is released from the frame. become. On the other hand, when the heat reflecting plate is configured as a plating process part inside the frame, heat is easily conducted to the frame through the plating process part, so that heat is easily emitted from the frame.

  Further, in the fixing device proposed in Patent Document 2, the structure for attaching the shielding plate is unknown, and in this respect, there is a problem similar to the case of the fixing device. In addition, in this fixing device, as in the case of the above fixing device, since the space between the shielding plate and the frame is open, heat enters the gap between the shielding plate and the frame to heat the frame. As a result, there is a risk of heat dissipation from the frame.

  The present invention has been made in view of the above problems, and it is easy to attach the heat reflecting plate, and it is difficult to come off even if the heat reflecting plate is heated and extended or deformed. It is an object of the present invention to provide a fixing device capable of reducing power consumption by effectively suppressing heat dissipation from a heat source and thus heat dissipation from an exterior cover in cooperation with the exterior cover.

  The fixing device according to the present invention includes a heating rotator and a pressing rotator that are pressed against each other so as to form a fixing nip portion through which a sheet-like material carrying an unfixed toner image passes, and the heating rotator and pressurizing member. In a state of surrounding each peripheral surface of the rotating body in a state surrounding the outer surface of the heat reflecting plate with a space between the heat reflecting plate and the outer surface of the heat reflecting plate in a state where the sheet-shaped material is excluded in a range excluding the passage portion. And an external cover made of synthetic resin, and the heat reflection plate is attached to the external cover in a locked state.

  Here, the state in which the heat reflecting plate is locked to the exterior cover means that at least a part of the heat reflecting plate is hooked and held on a predetermined portion of the exterior cover without using fixing means such as adhesion and screwing. It is in the state of attaching as it did. At least a part of the heat reflecting plate is, for example, all or a part of the end portion along the rotation axis direction of the heating rotator or the like, or the side along the circumferential surface (rotation) direction of the heating rotator or the like. It is the whole or a part of the end portion. However, in any case, the end of the heat reflecting plate on the side along the axial direction of the heating rotator and the pressing rotator should be in contact with the exterior cover. Is desirable. This can be realized, for example, by forming a part in contact with the corresponding end of the heat reflecting plate on the exterior cover side. Moreover, the said applicable edge part of a heat | fever reflecting plate becomes a part facing the passage part of a sheet-like thing normally.

  The heat reflecting plate is preferably attached so that all of its end portions are in contact with the exterior cover regardless of whether or not they are engaged. In this case, a sealed space (gap) is formed between the heat reflecting plate and the exterior cover arranged with a space therebetween. Note that the heat reflecting plate is not particularly limited as long as it can reflect high heat (radiant heat) generated from a heating source such as a heating rotating body to the rotating body side. Consists of composite materials with other materials. The synthetic resin constituting the exterior cover is preferably one having heat resistance or imparted with heat resistance, and more preferably exhibits a low thermal conductivity. Further, the sheet-like material may be any material that can carry out normal fixing processing by carrying a toner image and passing through the fixing nip portion.

  Further, in the fixing device, when the heat reflecting plate is bent and is rebounded using the repulsive elastic force generated when the shape is further deformed to the bending side, Good. The retaining to the exterior cover using the repulsive elastic force is formed, for example, by forming a retaining portion such as a recess to be retained on the exterior cover side, and the corresponding portion of the heat reflecting plate at the retaining portion. What is necessary is just to make it hold | maintain by pressing a part by a repulsive elastic force.

  When comprised in this way, a heat | fever reflecting plate can be attached in the state which latched easily to the exterior cover in the state using the repulsive elastic force with respect to curve deformation.

  In each of the fixing devices, the heat reflecting plate may be locked to the outer cover by inserting at least a part of the end of the heat reflecting plate into an insertion groove formed in the outer cover.

  When comprised in this way, it can attach in the state latched easily to the exterior cover by inserting the edge part of at least one part of a heat | fever reflecting plate in the insertion groove by the side of an exterior cover. In addition, in this case, since at least a part of the end portion of the heat reflecting plate is securely locked by the insertion groove on the exterior cover side, the heat reflecting plate can be held more stably.

  In each of the fixing devices, the outer cover is in contact with the outer surface of the end of the heat reflecting plate on the side along the circumferential direction of the heating rotator and the pressing rotator. It is good to form the edge part obstruction | occlusion part which obstruct | occludes the clearance gap between them. In this case, it is preferable that the entire region of the outer surface of the corresponding end portion of the heat reflecting plate is in contact with the end cover portion on the exterior cover side.

  When configured in this way, the gap between the corresponding side end of the heat reflecting plate and the outer cover is closed by the end closing portion, so that the outer cover is arranged at a distance from the heat reflecting plate. A space in a sealed state is formed between the two, and the space can function as an excellent (air) heat insulating layer.

  Further, each of the fixing devices has a pair of support frames disposed to face both ends of the heating rotator and the pressure rotator, and the exterior cover is brought into contact with the pair of support frames. It is good to attach to the said exterior cover in the state spaced apart from the said support frame while attaching in the state. The support frame at this time is usually made of metal from the viewpoint of securing support strength.

  In such a configuration, since the outer cover is in contact with the support frame but the heat reflection plate is not in contact, heat generated by heating the heat reflection plate is directly transmitted to the support frame. As a result, the support frame is heated to finally prevent the heat dissipation from the support frame itself. Further, since the exterior cover is attached in contact with the support frame, it can also function as a reinforcing arm (tie bar) that increases the strength of the support frame in the direction of the rotation axis, such as a heating rotator.

  According to the fixing device of the present invention, since the heat reflecting plate is attached to the exterior cover while being attached, it is particularly easy to attach (assemble) the heat reflecting plate, even if the heat reflecting plate is heated. Since it is not firmly fixed even if it extends or deforms, the extension or deformation can be absorbed by the displacement movement of the heat reflecting plate itself, and it becomes difficult to come off.

  In addition, the heat reflecting plate and the outer cover are disposed with a space therebetween, and in particular, at least the end of the heat reflecting plate along the axial direction of the heating rotator and the pressing rotator contacts the outer cover. By mounting in such a state, the heat generated by the heat reflector being heated due to the presence of a space layer between the heat reflector and the exterior cover becomes difficult to be transmitted to the exterior cover, and the exterior cover is heated by the heat of the heat reflector. As a result, heat radiation from the outer cover is suppressed.

  Therefore, in this fixing device, heat radiation from a heating source such as a heating rotator and hence heat radiation from the exterior cover can be effectively suppressed, and thus power consumption can be reduced. Further, even when a heat-sensitive component is arranged near the fixing device, it is possible to avoid inadvertently heating it.

[Embodiment 1]
1 and 2 show a main part of the fixing device according to the first embodiment of the present invention. FIG. 1 is a longitudinal sectional view thereof, and FIG. 2 is a schematic explanatory diagram when viewed from the lower side. .

  The fixing device 1 is installed so as to form a heating roll 2 installed so as to be driven to rotate, and a fixing nip portion N that is brought into pressure contact with the heating roll 2 and allows a sheet P carrying an unfixed toner image T to pass therethrough. Pressure belt 3, and the heat reflecting plate disposed in such a manner that each peripheral surface of the heating roll 2 and the pressure belt 3 is disposed so as to surround the paper P passing portion (E) and at a predetermined interval. 4, a pair of exterior cover 5 arranged in a state of surrounding the outside of the heat reflecting plate 4 with a predetermined interval, a heating roll 2 and a pressure belt 3 supported, and a pair of exterior cover 5 connected to each other. Side support frames 6A and 6B, and a peeling plate 7 for peeling the fixed paper P from the heating roll 2.

  In FIG. 1 and the like, reference numeral 8 denotes a space layer formed between the heat reflecting plate 4 and the exterior cover 5, and 9 denotes a paper P carrying an unfixed toner image T guided toward the fixing nip N and introduced. This is a paper introduction guide plate to be caused to move.

  The heating roll 2 has a core metal 21 formed in a relatively thin cylindrical shape with a metal such as aluminum or stainless steel, and a releasability such as tetrafluoroethylene or PFA formed on the outer peripheral surface of the core metal 21. The release layer 22 is made of a material. In addition, a plurality of halogen heaters 23 as heating sources are installed inside the heating roll 2 (the core metal 21). The heating roll 2 is heated to a predetermined temperature (fixing temperature, standby temperature, etc.) by controlling the energization state to the halogen heater 23 based on detection information from a temperature sensor (not shown) that measures the roll surface temperature. It is comprised so that it may be kept in the state kept. Further, the heating roll 2 receives rotational power from a rotational drive device (not shown) by a driven gear 25 and is rotationally driven in a direction indicated by an arrow at a predetermined speed.

  The pressure belt 3 includes an endless belt 31 having a structure in which a release layer such as PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer) is laminated on a belt base material of a heat-resistant film made of polyimide or the like, A pressure support pad structure 32 that is disposed on the inner peripheral surface side of the endless belt 31 and supports the belt 31 so as to be in pressure contact with the surface of the heating roll 2 and to be driven to rotate as the heating roll 2 rotates. It is configured. The pressure support pad structure 32 is in contact with the inner peripheral surface of the endless belt 31 and contributes to the formation of the fixing nip N. The pressure support pad structure 32 holds the pad 33 and holds the pad 33 at a predetermined pressure on the heating roll 2 side. A holder portion with a pressing mechanism for pressing, and a belt guide portion 35 for guiding the both ends of the holder portion while regulating the end position of the belt 31 are configured.

  In this example, as the heating roll 2, an elastic layer having a thickness of 1.6 mm made of silicone rubber or the like is formed on the cored bar 21 having an outer diameter of 26 mmφ, a wall thickness of 1.6 mm, and an axial length of 330 mm. The one having a release layer 22 made of PFA and having a thickness of 60 μm is used. The heating roll 2 is heated by a 1.1 kW halogen heater 23 so that the roll surface temperature during fixing is maintained at 160 ° C. As the pressure belt 3, an endless belt 31 formed by laminating a PFA release layer on the surface of a polyimide film belt having a belt circumferential length of 30 mm, a wall thickness of 60 μm, and an axial width of 344 mm was used.

  In the fixing device 1, the heating roll 2 and the pressure belt 3 are installed in a horizontal state (horizontal placement), and the fixing nip N is formed by pressing in this state. For this reason, the conveyance path of the paper P at the time of fixing is conveyed so as to rise from the lower side of the fixing device 1 toward the fixing nip N, and is also conveyed upward after passing through the fixing nip N. This is a route that travels in a substantially vertical direction.

  The heat reflecting plate 4 is a plate member made of metal such as stainless steel, and a rectangular flat plate having a length substantially corresponding to the axial length of the heating roll 2 and the pressure belt 3 is added to the heating roll 2 and the heating plate 2. It is used in a form (curved shape) bent into a curved surface shape (cross-sectional U shape) substantially along each outer peripheral surface (cylindrical side surface) of the pressure belt 3 (see FIG. 4).

  The heat reflecting plate 4A arranged on the heating roll 2 side was arranged in a state surrounding the roll peripheral surface (for the right half circumference in FIG. 1) with an interval La. Further, the heat reflecting plate 4B arranged on the pressure belt 3 side is arranged in a state of surrounding the belt outer peripheral surface (the left half circumference in FIG. 1) with an interval Lb. Then, a passage area Ein on the entrance side that passes when the sheet P before fixing is introduced into the fixing nip N, and a passage area Eout on the exit side that passes when the sheet P after fixing is discharged from the fixing nip N. , A space through which the paper P can pass is secured without the heat reflecting plate 4 being disposed.

  In this example, the heat reflecting plate 4 (A, B) is made of stainless steel (thermal conductivity: 20 W / mK) having a wall thickness of 0.2 mm and an axial length (width: W2) of 320 mm or 300 mm. . Further, the distance La from the heating roll 2 of the heat reflecting plate 4A was set to about 5 mm, and the distance Lb from the pressure belt of the heat reflecting plate 4B was set to about 5 mm.

  The exterior cover 5 is formed by molding using, for example, polycarbonate mixed with glass fiber, and has a shape that can surround the outside of the heat reflecting plate 4 with a predetermined interval. In this example, a set of exterior covers 5A and 5B having a shape having a curved surface portion (50) substantially following the curved surface shape of the heat reflecting plates 4A and 4B disposed on the heating roll 2 side and the pressure belt 3 side, respectively. It is said. In this example, the exterior cover 5 (A, B) is formed of glass-mixed polycarbonate (thermal conductivity: 0.2 W / mK). The length (width: W5) in the axial direction of the exterior cover 5 (A, B) was 380 mm.

  The pair of side support frames 6A and 6B are arranged facing each other at both ends of the heating roll 2 and the pressure belt 3, and support the heating roller 2 so as to be rotatable and The pressure support pad structure 32 is supported. Further, the exterior cover 5 (A, B) is fixedly attached to the side support frames 6A, 6B so as to connect both the frames 6 (A, B) along the rotation axis direction of the heating roll 2. Yes. As a result, the exterior cover 5 (A, B) functions as a tie bar that reinforces the mechanical strength of the side support frames 6A, 6B in the direction of the rotation axis of the heating roll 2. In this example, the support frames 6A and 6B are formed of a galvanized steel plate.

  In the fixing device 1, as shown in FIGS. 1 and 3 to 5 and the like, the heat reflecting plate 4 (A, B) is disposed at least on the side along the axial direction of the heating roll 2 and the pressure belt 3. It is attached to the exterior cover 5 (A, B) so that the end portions (hereinafter also referred to as “axial end portions”) 41 and 42 are in contact with each other.

  In this example, the entire end portion of the outer cover 5 (A, B) facing the axial end portions 41, 42 of the heat reflecting plate 4 (A, B) is placed inside the curved shape (heat reflection). Folded end portions 51 and 52 are formed in a shape that is bent on the side where the plate 4 is present, and all of the axial end portions 41 and 42 of the heat reflecting plate 4 are placed inside the front end portions of the respective bent end portions. Locking portions 53 and 54 for locking are provided. The locking portions 53, 54 have a shape in which corners inside the tip end portions of the bent end portions 51, 52 are cut out to have an L-shaped cross section over the entire region and are deeper than the thickness of the heat reflecting plate 4. .

  As a result, the heat reflecting plate 4 (A, B) is attached to the exterior cover 5 (A, B) by moving the heat reflecting plate 4 (A, B) slightly inward (the direction in which the axial end portions 41, 42 are brought closer). ) In the state of being elastically deformed so as to be bent toward the inside of the curved surface portion 50 of the exterior cover 5 (A, B), and then the axial end portions 41, 42 are bent on the exterior cover 5 (A, B). It completes by making it the state which hooked on each latching | locking part 53 and 54 in the edge parts 51 and 52 (FIG. 4). At this time, a rebound elastic force F is generated in the heat reflecting plate 4 (A, B) in an outward direction to restore (expand) the elastic deformation at the time of attachment. The direction end portions 41 and 42 are locked against each other by being strongly pressed against the locking portions 53 and 54 (FIG. 3). Thus, the heat reflecting plate 4 (A, B) can be easily attached to the exterior cover 5 (A, B) without using fixing means such as adhesion or screwing.

  In addition, in the fixing device 1, as shown in FIGS. 4 to 7, along the rotation circumferential direction of the heating roll 2 of the heat reflecting plate 4 (A, B) in the exterior cover 5 (A, B). In contact with the outer surfaces of the circumferential side end portions 43, 44 of the heat reflecting plate 4 (A, B) at portions facing the side end portions (hereinafter also referred to as “circumferential end portions”) 43, 44 End ribs 55 and 56 are formed to close gaps between the end portions 43 and 44 and the exterior cover 5 (A and B).

  In this example, the end ribs 55 and 56 are raised at a constant height inside the curved surface portion 50, and the upper surface portions 55 a and 56 a are formed in a curved surface shape having the same curvature as the curved surface portion 50. Further, the end ribs 55 and 56 are set so that the height of the upper surface portions 55a and 56a is the same as the bottom surface of the locking portions 53 and 54 cut out (FIGS. 4 and 5). .

  Further, in the fixing device 1, as shown in FIG. 2, in the exterior cover 5 (A, B) attached so as to be connected to the side support frames 6 A, 6 B along the rotation axis direction of the heating roll 2, The reflector 4 (A, B) is attached in a state of being separated from the side support frames 6A, 6B by a predetermined distance α1, α2.

  Next, the operation of the fixing device 1 will be described.

  At the time of fixing, the heating roll 2 is heated to a predetermined surface temperature (fixing temperature) by the halogen heater 23 and is rotated in the direction of the arrow. At this time, the pressure belt 3 is driven to rotate while forming the fixing nip portion N with the heating roll 2.

  The sheet P on which the unfixed toner image T formed in the image forming unit (not shown) is transferred to the fixing device 1 in such a fixable state as shown in FIG. , And is conveyed so as to be introduced into the fixing nip N. The unfixed toner image T is melted and fixed on the paper P by being heated and pressurized through the fixing nip N. The sheet P after the fixing process passes through the exit area Eout and is discharged out of the fixing device.

  Further, the fixing device 1 stands by in a state where the heating roll 2 is heated to a predetermined standby temperature until the next fixing operation is started even when the paper P to be fixed is not introduced and passed.

  Also in the fixing device 1, heat is mainly released from the heating roll 2 during fixing or standby, but the heat is reflected by the heat reflecting plates 4 (A, B) arranged around the heat roller 2. It is difficult to escape to the outside and the loss of heat energy is reduced.

  Further, the heat reflecting plates (A, B) are attached in a state where at least the axial end portions 41, 42 are in contact with the bent end portions 51, 52 of the exterior cover 5 (A, B) (see FIG. 1, 3), heat does not enter through the gap between the heat reflecting plate (A, B) and the outer cover 5 (A, B), and the outer cover 5 (A, B) is not heated.

  Further, the heat reflecting plate 4 (A, B) is in contact with the upper surface portions 55a, 56a of the end rib portions 55, 56 whose circumferential end portions 43, 44 are formed on the exterior cover 5 (A, B) side. (Figs. 4-6), the gap between the circumferential end portions 43, 44 of the heat reflecting plate 4 (A, B) and the outer cover 5 (A, B) is the end rib 55. 56, the space layer in a state of being sealed between the heat reflecting plate 4 (A, B) and the exterior cover 5 (A, B) arranged with a space therebetween. 8 is formed. As a result, the space layer 8 functions as an excellent air heat insulating layer, and even when the heat reflecting plate 4 is heated, the heat is insulated by the space layer 8, so that it is difficult to be transmitted to the exterior cover 5 side. become.

  For this reason, heat dissipation from the outer cover 5 (A, B) is prevented. When the heating state was actually examined, the surface (inner side surface) of the heat reflecting plate 4 is located at the portion where the heat reflecting plate 4 and the outer cover 5 are separated and the air layer 8 exists as shown in the upper part of FIG. When the temperature was about 150 ° C., the outer surface of the outer cover 5 was about 70 ° C. Further, in the portion where the heat reflecting plate 5 is in contact with the end rib 55 (56) of the exterior cover 5 as shown in the lower part of FIG. 5, the temperature of the inner surface of the heat reflecting plate 4 is about 150 ° C. Sometimes the outer surface of the outer cover 5 was about 130 ° C.

  Further, since the heat reflecting plate 4 (A, B) is attached in a state of being locked to the outer cover 5 (A, B), as described above, the heat reflecting plate 4 is attached (assembled) to the outer cover 5. ), And even if the heat reflecting plate 4 is heated and extended or deformed, it is not firmly fixed. Therefore, the extension or deformation is displaced (in this example, the axis of the heat reflecting plate 4). The directional end portions 41 and 42 can be absorbed in the axial direction along the locking portions 53 and 54), and the like, and are difficult to come off. Thereby, generation | occurrence | production of the malfunction which the heat reflection board 4 remove | deviates and touches the heating roll 2 grade | etc., Is prevented, and it also becomes possible to arrange | position a heat reflection board in the state which approached the heating roll 2. In addition, by performing such an attachment method, it is not necessary to request that the heat reflecting plate 4 has a high mechanical strength on the assumption that the heat reflecting plate 4 is strongly attached, and the heat reflecting plate 4 is reduced in thickness and weight. It becomes possible.

  Therefore, in the fixing device 1, the heat reflection plate 4 cooperates with the exterior cover 5 to effectively suppress the heat radiation from the heating source such as the heating roll 2 and the heat radiation from the exterior cover 5 to reduce the heat energy loss. The power consumption can be reduced.

  Further, in the fixing device 1, the heat reflecting plate 4 (A, B) is attached in a state of being separated from the side support frames 6A, 6B by a predetermined distance (FIG. 2). The heat generated by heating B) is not directly transmitted to the side support frames 6 (A, B), and the support frames 6 (A, B) are heated by heating the support frames 6 (A, B). ) Can also be prevented. This can also reduce the loss of heat energy and reduce power consumption.

[Embodiment 2]
FIG. 7 shows a main part (a part of) a fixing device according to Embodiment 2 of the present invention.

  This fixing device has the same configuration as that of the fixing device 1 according to the first embodiment, except that the manner in which the heat reflecting plate 4 (A, B) is locked to the exterior cover 5 (A, B) is changed. For this reason, in FIG. 7, the same reference numerals are given to the portions common to the fixing device 1 according to the first embodiment, and the description of the common components is omitted below. (The same applies to the following embodiments).

  That is, in this example, as shown in FIGS. 7 and 8, the heat reflecting plate 4 (A, B) is connected to the axial end portions 41, 42 of the outer cover 5 (A, B). The outer cover 5 (A, B) is locked by being inserted into insertion grooves 57, 58 formed at the front end portion of 52. The insertion grooves 57 and 58 were linearly provided along the axial direction of the heating roll 2 with a width corresponding to the thickness of the heat reflecting plate 4. Moreover, about the heat | fever reflection board 4 (A, B), the insertion parts 41a and 42a of the state bent to the outer side so that the axial direction edge parts 41 and 42 could be inserted in the insertion grooves 57 and 58 were formed.

  When attaching the heat reflecting plate 4 by such a locking, in addition to the insertion into the insertion groove, as in the case of the heat reflecting plate 4 in the first embodiment, Although it is preferable to use the rebound resilience force (F) in the outward direction generated along with the elastic deformation, only the attachment by the insertion may be used.

  Even in the fixing device locked by this insertion, the predetermined end portions (insertion end portions 41a and 42a) of the heat reflecting plate 4 are easily inserted into the insertion cover grooves 57 and 58 on the exterior cover 5 side. Can be attached in a locked state. Further, since at least a part of the end portion of the heat reflecting plate 4 is securely locked by the insertion grooves 57 and 58 on the exterior cover 5 side, the heat reflecting plate 4 can be held in a more stable state, Even if the reflecting plate 4 is extended or deformed by heating, it is difficult to come off.

[Other embodiments]
In the first and second embodiments, the case where the heat reflecting plate 4 is attached with the entire region of the end portions 41 and 42 in the axial direction locked to the exterior cover 5 is illustrated. The other end portions in the axial direction 41 and 42 may be simply attached to the exterior cover 5 in a state where the portions are locked.

  In the first and second embodiments, all or part of the circumferential end portions 43 and 44 of the heat reflecting plate 4 may be attached to the exterior cover 5 in a locked state, or the heat reflecting plate 4 may be attached. Both the axial end portions 41 and 42 and the circumferential end portions 43 and 44 may be attached to the exterior cover 5 in a locked state.

  Furthermore, an elastic member such as glass wool can be installed in the space layer 8 as necessary.

  In addition, with respect to the fixing device, the heating roll 2 and the pressure belt 3 may be arranged in a vertically placed type instead of the horizontally placed type as illustrated in the first and second embodiments. it can. Further, for example, a pressure roll can be applied instead of the pressure belt 3.

FIG. 2 is a longitudinal sectional view showing a main part of the fixing device according to the first embodiment. FIG. 2 is a schematic explanatory diagram illustrating a state when the fixing device of FIG. 1 is viewed from below. FIG. 2 is an explanatory cross-sectional view illustrating a configuration of a heat reflecting plate and an exterior cover in the fixing device of FIG. 1. It is a schematic perspective view which shows the state which the heat | fever reflecting plate of FIG. 3 and the exterior cover disassembled, and the attached (assembled) state. It is sectional drawing in alignment with the Q1-Q1 line in the state of FIG. 4, and Q2-Q2. FIG. 5 is a cross-sectional view taken along line Q3-Q3 in the attached state of FIG. FIG. 6 is a longitudinal sectional view illustrating a main part (a configuration of a heat reflecting plate and an exterior cover) of a fixing device according to a second embodiment. It is a schematic perspective view which shows the state which the heat | fever reflecting plate and exterior cover of FIG. 7 decomposed | disassembled, and the attached (assembled) state.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Fixing device, 2 ... Heating roll (rotating body for heating), 3 ... Pressure belt (rotating body for pressing), 4 ... Heat reflecting plate, 5 ... Exterior cover, 6A, 6B ... Side support frame (a pair of supports) Frame, 41, 42 ... axial end (end on the side along the axial direction), 43, 44 ... circumferential end (end on the side along the circumferential direction), 43a, 44a ... insertion end, 51 , 52 ... bent end, 53, 54 ... locking part, 55, 56 ... end rib (end closed part), T ... unfixed toner image, P ... paper (sheet-like material), N ... fixing nip part , L1, L2 ... interval, F ... repulsive elastic force, α ... separation distance, E ... paper passage portion.

Claims (5)

A heating rotator and a pressurizing rotator that are press-contacted so as to form a fixing nip portion through which a sheet-like material carrying an unfixed toner image passes, and each peripheral surface of the heating rotator and pressurizing rotator A heat reflecting plate arranged in a state surrounding the sheet-like material with a gap in a range excluding a passing portion, and a synthetic resin arranged in a state surrounding the heat reflecting plate with a space therebetween An exterior cover,
The fixing device, wherein the heat reflecting plate is attached to the exterior cover in a locked state.   2. The heat reflecting plate according to claim 1, wherein the heat reflecting plate is locked to the exterior cover using a repulsive elastic force generated when the heat reflecting plate is bent and further deformed to the bending side. Fixing device.   The fixing device according to claim 1, wherein the heat reflecting plate is locked to the outer cover by inserting at least a part of an end portion thereof into an insertion groove formed in the outer cover.   An end portion that contacts the outer surface of the end portion of the heat reflecting plate on the side along the circumferential direction of the heating rotating body and the pressurizing rotating body and closes the gap between the end portion and the outer cover. The fixing device according to claim 1, wherein a blocking portion is formed.   The heating rotating body and the pressing rotating body have a pair of support frames disposed facing both ends, and the exterior cover is attached to the pair of support frames in contact with the pair of support frames. The fixing device according to claim 1, wherein the reflection plate is attached to the exterior cover in a state of being separated from the support frame.

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