JP2017215432A - Fixing device and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of screws to be used in a structure of coupling a reflection member to a stay.SOLUTION: A fixation device 100 comprises an endless belt 110, a heater (halogen lamp 120) disposed inside the endless belt 110, a reflection member (reflection plate 140) reflecting radiant heat coming from the heater, a stay 150, a nip member (nip plate 130) and a backup member (pressure roller 170) for forming a nip part NP between the endless belt 110 and itself. The reflection member includes supported parts (upstream extending wall 145 and downstream extending wall 147) supported by support parts F11 and F12 of the stay 150. The fixation device 100 further comprises a spring (leaf spring 190) disposed inside the endless belt 110 and having a press part 191 for pressing the supported parts against the support parts of the stay 150.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a fixing device for thermally fixing a toner image on a recording sheet and a method for manufacturing the same.

  2. Description of the Related Art Conventionally, a belt fixing type fixing device includes an endless belt, a reflecting plate that reflects radiant heat from a heater, and a stay that supports the reflecting plate (see Patent Document 1).

JP 2013-164473 A

  In the above-described conventional configuration, the reflecting plate may be coupled by being screwed to a stay at a plurality of locations. In such a case, as the number of screws increases, there is a possibility that the connecting operation between the reflector and the stay becomes complicated. In addition, since the amount of facets generated from the periphery of the screw when it is screwed into the stay increases in proportion to the number of screws, when the number of screws is large, an operator may need to remove the facets. The facet that was complicated or could not be removed adhered to the inner peripheral surface of the endless belt, and the inner peripheral surface of the endless belt might be damaged by the facet when the endless belt was rotated.

  Accordingly, an object of the present invention is to reduce the number of screws to be used in a structure in which a reflector (reflecting member) is coupled to a stay.

In order to solve the above problems, a fixing device according to the present invention includes an endless belt, a heater disposed inside the endless belt, and a reflection member disposed inside the endless belt and reflecting radiant heat from the heater. A stay disposed inside the endless belt, a nip member disposed inside the endless belt, the endless belt sandwiched between the nip member, and a nip portion between the endless belt A backup member to be formed, and the recording sheet is conveyed in a predetermined conveying direction at the nip portion.
The reflection member has a supported portion supported by the support portion of the stay.
The fixing device further includes a spring disposed inside the endless belt and having a pressing portion that presses the supported portion against the supporting portion of the stay.

  According to this configuration, the reflecting member can be coupled to the stay by pressing the supported portion of the reflecting member against the stay supporting portion by the spring, so the number of screws for coupling the reflecting member and the stay is reduced. Can be reduced (including 0) as compared with the prior art. As a result, the connecting operation between the reflecting member and the stay can be facilitated. Further, it is possible to suppress damage caused by the facets on the inner peripheral surface of the endless belt.

  The fixing device manufacturing method according to the present invention includes a step of coupling the reflecting member and the stay by a spring, and a step of inserting the reflecting member and the stay coupled by the spring into the endless belt.

  According to this manufacturing method, since the reflecting member and the stay can be coupled by the spring, the number of screws for coupling the reflecting member and the stay can be reduced (including 0) as compared with the related art. As a result, the connecting operation between the reflecting member and the stay can be facilitated. Further, it is possible to suppress damage caused by the facets on the inner peripheral surface of the endless belt.

  According to the present invention, the number of screws to be used can be reduced in the structure in which the reflecting member is coupled to the stay. As a result, the connecting operation between the reflecting member and the stay can be facilitated. Further, it is possible to suppress damage caused by the facets on the inner peripheral surface of the endless belt.

1 is a cross-sectional view illustrating a color laser printer including a fixing device according to an embodiment of the present invention. FIG. 3 is a cross-sectional view of the fixing device taken along the center in the left-right direction. It is a disassembled perspective view which decomposes | disassembles and shows a nip board etc. FIG. FIG. 4 is a cross-sectional view (a) of the fixing device cut at one end in the left-right direction, a cross-sectional view (b) showing the amount of inclination of the upstream wall, and a cross-sectional view (c) showing the amount of inclination of the downstream wall. It is a perspective view which shows a side guide. It is an expansion perspective view which shows the modification of a reflecting plate. It is an expansion perspective view which shows the modification of a protrusion and a through-hole. It is sectional drawing which shows the form which reversed the direction of the leaf | plate spring. It is sectional drawing which shows the modification of a stay, a reflecting plate, and a leaf | plate spring. It is sectional drawing which shows the modification of a convex part. It is sectional drawing which shows the modification of a convex part.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In the following description, unless otherwise specified, the vertical direction shown in FIG. 1 is up and down, the right side in FIG. 1 is front, the left side is rear, the front side of the paper is left, and the back side of the paper is right. Indicates.

  As shown in FIG. 1, the color laser printer 1 includes a paper feeding unit 5 that supplies paper 51, an image forming unit 6 that forms an image on the fed paper 51, and an image in the main body housing 2. A paper discharge unit 7 for discharging the formed paper 51.

  In the lower part of the main body housing 2, the paper feeding unit 5 supplies the image forming unit 6 with a paper feeding tray 50 that is attached to and detached from the main body housing 2 by a slide operation from the front side and the paper 51 in the paper feeding tray 50. And a sheet feeding mechanism M1 that feeds out.

  The paper feed mechanism M1 includes a pickup roller 52, a separation roller 53, a separation pad 54, and the like provided in the vicinity of the front end of the paper feed tray 50, so that one sheet of paper 51 in the paper feed tray 50 can be obtained. They are separated one by one and sent upward. The paper 51 transported upward passes between the paper dust removing roller 55 and the pinch roller 56, is then redirected through the transport path 57, and is supplied onto a transport belt 73 described later. .

  The image forming unit 6 includes a scanner unit 61, a process unit 62, a transfer unit 63, and a fixing device 100.

  The scanner unit 61 is provided in the upper part of the main body housing 2 and includes a laser light emitting unit, a polygon mirror, a plurality of lenses, and a reflecting mirror (not shown). In the scanner unit 61, a laser beam emitted from the laser beam emitting unit is scanned at high speed in the left-right direction by a polygon mirror in correspondence with each color of cyan, magenta, yellow, and black, and is passed or reflected by a plurality of lenses and reflecting mirrors. After that, each photosensitive drum 31 is irradiated.

  The process unit 62 is disposed below the scanner unit 61 and above the sheet feeding unit 5, and includes the photosensitive unit 3 that can move in the front-rear direction with respect to the main body housing 2. The photoreceptor unit 3 includes a drum subunit 30 and a developing cartridge 40 attached to the drum subunit 30.

The drum subunit 30 includes a photosensitive drum 31, a scorotron charger 32, and the like.
The developing cartridge 40 contains toner therein and includes a supply roller 41, a developing roller 42, a layer thickness regulating blade 43, and the like.

  Such a process unit 62 functions as follows. The toner in the developing cartridge 40 is supplied to the developing roller 42 by the supply roller 41, and at this time, the toner is frictionally charged between the supply roller 41 and the developing roller 42. The toner supplied to the developing roller 42 is rubbed by the layer thickness regulating blade 43 as the developing roller 42 rotates, and is carried on the surface of the developing roller 42 as a thin layer having a constant thickness.

  On the other hand, in the drum subunit 30, the scorotron charger 32 uniformly charges the photosensitive drum 31 by corona discharge. The charged photosensitive drum 31 is irradiated with laser from the scanner unit 61, and an electrostatic latent image is formed on the photosensitive drum 31.

  Thereafter, the toner carried on the developing roller 42 is supplied to the electrostatic latent image on the photosensitive drum 31. As a result, the electrostatic latent image on the photosensitive drum 31 is visualized, and a toner image by reversal development is carried on the surface of the photosensitive drum 31.

The transfer unit 63 includes a driving roller 71, a driven roller 72, a conveyance belt 73, a transfer roller 74, and a cleaning unit 75.
The driving roller 71 and the driven roller 72 are arranged in parallel apart from each other in the front-rear direction, and a conveyance belt 73 formed of an endless belt is wound around them. The outer surface of the conveyance belt 73 is in contact with each photosensitive drum 31. A transfer roller 74 is disposed inside the conveyor belt 73 so as to sandwich the conveyor belt 73 between the photosensitive drums 31. A transfer bias is applied to the transfer roller 74. At the time of image formation, the paper 51 transported by the transport belt 73 is sandwiched between the photosensitive drum 31 and the transfer roller 74, and the toner image on the photosensitive drum 31 is transferred to the paper 51.

  The cleaning unit 75 is disposed below the conveyance belt 73, removes toner adhering to the conveyance belt 73, and drops the removed toner in a toner storage unit 76 disposed below the cleaning belt 75.

  The fixing device 100 is provided behind the transfer unit 63 and thermally fixes the toner image transferred onto the paper 51 onto the paper 51. The fixing device 100 will be described in detail later.

  In the paper discharge unit 7, a paper discharge side conveyance path 91 for the paper 51 is formed so as to extend upward from the exit of the fixing device 100 and reverse to the front side. A plurality of transport rollers 92 that transport the paper 51 are disposed in the middle of the paper discharge side transport path 91. A paper discharge tray 93 for accumulating the printed paper 51 is formed on the upper surface of the main body housing 2, and the paper 51 discharged from the paper discharge side transport path 91 by the transport roller 92 is placed on the paper discharge tray 93. Accumulated.

  As shown in FIG. 2, the fixing device 100 includes an endless belt 110, a halogen lamp 120 as an example of a heater, a nip plate 130 as an example of a nip member, a reflection plate 140 as an example of a reflection member, and a stay. 150, a heat insulating member 160, a pressure roller 170 as an example of a backup member, a side guide 180, and a leaf spring 190 as an example of a spring. The leaf spring 190 is provided as a separate member from the nip plate 130.

  In the following description, the conveyance direction (substantially front-rear direction) of the paper 51 is simply referred to as “conveyance direction”, and the direction in which the halogen lamp 120 extends, that is, the longitudinal direction (substantially left-right direction) of the halogen lamp 120 is simply “longitudinal”. "Direction". The transport direction corresponds to a sliding direction in which the endless belt 110 slides on the nip plate 130, that is, a moving direction of the endless belt 110 at a nip portion NP described later. The longitudinal direction of the halogen lamp 120 is along the rotation axis of the pressure roller 170.

  The endless belt 110 is an endless (or cylindrical) belt having heat resistance and flexibility, is configured to be rotatable, and both longitudinal ends thereof are guided by side guides 180 (see FIG. 5). . The inner peripheral surface 111 of the endless belt 110 is coated with grease for reducing frictional resistance with the nip plate 130 and the like.

  The endless belt 110 may be configured as a metal belt having a metal base material and resin coated on the outer periphery of the base material, or may have a rubber layer on the metal surface. The rubber layer may further have a non-metallic protective layer formed of a fluororesin coating or the like. Further, the base material of the endless belt 110 may be a resin such as a polyimide resin.

  The halogen lamp 120 is a heating element that heats the toner on the paper 51 by heating the endless belt 110, and is disposed inside the endless belt 110 at a predetermined interval from the endless belt 110. The dimension in the longitudinal direction of the halogen lamp 120 is larger than the dimensions in the longitudinal direction of the nip plate 130, the heat insulating member 160, and the reflecting plate 140. The halogen lamp 120 is arranged so that both ends thereof protrude outward in the longitudinal direction from the nip plate 130, the heat insulating member 160, and the reflection plate 140.

  The nip plate 130 is disposed below the halogen lamp 120 inside the endless belt 110 and is in contact with the inner peripheral surface 111 of the endless belt 110. The nip plate 130 has a metal plate, and is formed by bending the metal plate into a substantially U shape in cross-sectional view. The metal plate may be an aluminum plate or a SUS plate.

  More specifically, the nip plate 130 includes, in a cross section orthogonal to the longitudinal direction, a base portion 131 extending along the transport direction, and a side wall portion extending in a direction away from the pressure roller 170 from each end portion in the transport direction of the base portion 131. 132. Here, the direction away from the pressure roller 170 refers to a direction that intersects with the conveyance direction of the paper 51 in the nip portion NP and is away from the pressure roller 170.

The base 131 is formed in a rectangular flat plate shape (see FIG. 3) that is long in the longitudinal direction, and the lower surface thereof is in contact with the inner peripheral surface 111 of the endless belt 110.
The side wall 132 is formed in a rectangular flat plate shape (see FIG. 3) that is long in the longitudinal direction.

  The heat insulating member 160 is a resin frame for suppressing heat from being transmitted from the nip plate 130 to the stay 150, and is disposed between the nip plate 130 and the stay 150. It is formed into a shape. More specifically, the heat insulating member 160 extends in a cross section perpendicular to the longitudinal direction, a base portion 161 extending along the transport direction, and a direction away from the pressure roller 170 from each end portion in the transport direction of the base portion 161. It mainly has a side wall 162. The heat insulating member 160 is made of, for example, LCP (Liquid Crystal Polymer) which is a heat resistant resin.

  Each end portion 161A of the base portion 161 in the conveying direction is in contact with the nip plate 130 as a convex portion protruding downward from the central portion 161B. As a result, an air layer is formed between the central portion 161B and the nip plate 130.

  The pressure roller 170 is a member that sandwiches the endless belt 110 with the nip plate 130 and forms a nip portion NP with the endless belt 110, and is disposed below the nip plate 130. The pressure roller 170 includes a cylindrical roller main body 171 and a shaft 172 that is covered with the roller main body 171 and can be rotated together with the roller main body 171. The roller body 171 includes a rubber layer that covers the shaft 172 and a release layer that covers the outer periphery of the rubber layer.

  The pressure roller 170 is configured to rotate by being driven by a driving force transmitted from a motor (not shown) provided in the main body casing 2, and is endless due to frictional force with the endless belt 110 by being rotationally driven. The belt 110 is driven to rotate.

  The reflection plate 140 is a member that reflects the radiant heat (light) from the halogen lamp 120 toward the inner peripheral surface 111 of the endless belt 110 and applies it to the inner peripheral surface 111. It arrange | positions between the board | plates 130 (The nip part NP mentioned later in detail). In other words, the reflector plate 140 is disposed so as to cover the halogen lamp 120 from below, and reflects the radiant heat from the halogen lamp 120 upward, that is, in a direction away from the nip plate 130.

  The reflection plate 140 includes a metal plate, and is formed by bending the metal plate into a substantially U shape when viewed in cross section. The metal plate may be an aluminum plate or a SUS plate.

  More specifically, as shown in FIG. 2, the reflecting plate 140 includes an upstream wall 141 disposed on the upstream side in the transport direction and a transport direction with respect to the upstream wall 141 in a cross section cut at the center in the longitudinal direction. It has the downstream wall 142 arrange | positioned at intervals in the downstream, and the center wall 143 which connects the lower end part of the upstream wall 141 and the downstream wall 142. The upstream wall 141 is inclined toward the downstream side in the transport direction as it approaches the central wall 143, specifically toward the lower side. In other words, the upstream wall 141 is inclined at a predetermined inclination amount θ1 (angle) with respect to a side wall portion 152 of the stay 150 described later (specifically, an upstream support portion F11 shown in FIG. 4B).

  The downstream wall 142 is inclined toward the upstream side in the transport direction as it approaches the central wall 143, specifically toward the lower side. In other words, the downstream wall 142 is inclined at a predetermined inclination amount θ2 (angle) with respect to a side wall portion 152 of the stay 150 described later (specifically, the downstream support portion F12 shown in FIG. 4C).

  As shown in FIG. 3, the upstream wall 141, the downstream wall 142, and the central wall 143 are formed in a rectangular plate shape that is elongated in the longitudinal direction. Therefore, the upstream wall 141, the downstream wall 142, and the central wall 143 form a recess 140A that is long in the longitudinal direction. Moreover, each upper end and each lower end of the upstream wall 141 and the downstream wall 142 are along the longitudinal direction.

  The reflection plate 140 includes two upstream intermediate walls 144 and 144 connected to the longitudinal ends of the upstream wall 141, and two upstream extensions connected to the longitudinal outer ends of the upstream intermediate walls 144 and 144, respectively. And exit walls 145 and 145. In other words, the upstream extension wall 145 is connected to the longitudinal end of the upstream wall 141 via the upstream intermediate wall 144.

  Further, the reflecting plate 140 includes two downstream intermediate walls 146 and 146 connected to the longitudinal ends of the downstream wall 142 and two downstream extensions connected to the longitudinal outer ends of the downstream intermediate walls 146 and 146, respectively. And exit walls 147, 147. In other words, the downstream extension wall 147 is connected to the longitudinal end portion of the downstream wall 142 via the downstream intermediate wall 146.

  The upper end of the upstream intermediate wall 144 extends in the longitudinal direction from the upper end of the upstream wall 141, and the lower end of the upstream intermediate wall 144 extends obliquely from the lower end of the upstream wall 141 toward the outside in the longitudinal direction and the upstream side in the transport direction. That is, the upper end of the upstream intermediate wall 144 and the upper end of the upstream wall 141 are aligned in a straight line, and the lower end of the upstream intermediate wall 144 is inclined with respect to the lower end along the longitudinal direction of the upstream wall 141. Yes.

  The upstream extension wall 145 extends from the upstream intermediate wall 144 outward in the longitudinal direction. Specifically, the upstream extension wall 145 extends along the vertical direction, and the upper end thereof extends along the longitudinal direction from the upper end of the upstream intermediate wall 144, and the lower end thereof extends along the longitudinal direction from the lower end of the upstream intermediate wall 144. It extends. Accordingly, as shown in FIGS. 4A and 4B, the upstream extension wall 145 is formed along an upstream support portion F <b> 11 of the stay 150 described later. That is, the inclination amount of the upstream extension wall 145 with respect to the upstream support portion F11 is substantially 0 °, which is smaller than the inclination amount θ1 of the upstream wall 141 with respect to the upstream support portion F11.

  As shown in FIG. 3, the outer surface of the upstream extension wall 145 on the outer side in the transport direction is a supported surface FA as an example of a supported portion. That is, the upstream extending wall 145 has a supported surface FA as an example of a supported portion. The upstream extension wall 145 is formed with a through hole H1 as an example of a first opening that fits into a protrusion B1 of a stay 150 described later. The through hole H1 is formed in a circular shape. In the present specification, the term “fitting” includes fitting the protrusion B1 and the through hole H1 with some play between them (free fitting).

  The downstream intermediate wall 146 and the downstream extension wall 147 are symmetrical to the upstream intermediate wall 144 and the upstream extension wall 145 in the transport direction. Specifically, the downstream intermediate wall 146 has an upper end extending from the upper end of the downstream wall 142 along the longitudinal direction, and a lower end extending obliquely from the lower end of the downstream wall 142 toward the outside in the longitudinal direction and downstream in the transport direction. Yes. That is, the upper end of the downstream intermediate wall 146 and the upper end of the downstream wall 142 are continuously arranged in a straight line, and the lower end of the downstream intermediate wall 146 is inclined with respect to the lower end along the longitudinal direction of the downstream wall 142. Yes.

  The downstream extension wall 147 extends from the downstream intermediate wall 146 outward in the longitudinal direction. Specifically, the downstream extension wall 147 extends along the vertical direction, and the upper end thereof extends along the longitudinal direction from the upper end of the downstream intermediate wall 146, and the lower end thereof extends along the longitudinal direction from the lower end of the downstream intermediate wall 146. It extends. Accordingly, as shown in FIGS. 4A and 4C, the downstream extending wall 147 is formed along the downstream support portion F12 of the stay 150 described later. That is, the inclination amount of the downstream extension wall 147 with respect to the downstream support portion F12 is substantially 0 °, and is smaller than the inclination amount θ2 of the downstream wall 142 with respect to the downstream support portion F12.

  As shown in FIG. 3, the outer surface of the downstream extension wall 147 on the outer side in the conveyance direction is a supported surface FA as an example of a supported portion. That is, the downstream extending wall 147 has a supported surface FA as an example of a supported portion. The downstream extension wall 147 is formed with a through hole H2 as an example of a first opening that fits with a protrusion B2 of a stay 150 to be described later. The through hole H2 is formed in a circular shape.

  The central wall 143 extends from an end portion on the outer side in the longitudinal direction of one upstream extension wall 145 to an end portion on the outer side in the longitudinal direction of the other upstream extension wall 145. The central portion of the central wall 143 in the longitudinal direction is formed in a rectangular plate shape extending along the longitudinal direction, and the width in the transport direction gradually increases from each longitudinal end portion of the central portion toward the outside in the longitudinal direction. Later, it extends along the longitudinal direction. That is, both end portions of the central wall 143 have a larger width in the transport direction than the central portion, and protrude upstream and downstream in the transport direction with respect to the central portion.

  The reflecting plate 140 includes an upstream flange 141 148 extending upstream from the upper ends of the upstream wall 141, the upstream intermediate walls 144, 144, and the upstream extending walls 145, 145, the downstream wall 142, and the downstream intermediates. A downstream flange portion 149 extending downstream from the upper ends of the walls 146 and 146 and the downstream extension walls 147 and 147 in the transport direction.

  As shown in FIG. 2, the stay 150 is a metal frame for ensuring the rigidity of the nip plate 130, and is disposed on the side opposite to the halogen lamp 120 with respect to the reflection plate 140 inside the endless belt 110. The nip plate 130 is supported via the heat insulating member 160. The stay 150 is formed by bending a relatively rigid metal, such as a steel plate, into a substantially U shape in cross section. Note that in this specification, the metal may be an alloy containing a nonmetal such as carbon.

  More specifically, the stay 150 has, in a cross section orthogonal to the longitudinal direction, a base 151 extending along the transport direction, and a side wall 152 extending in a direction away from the pressure roller 170 from each end in the transport direction of the base 151. And mainly. As shown in FIG. 3, a recess portion 150 </ b> A that is long in the longitudinal direction is formed by the base portion 151 and the inner surface F <b> 1 of each side wall portion 152. Note that the longitudinal dimension of the stay 150 is larger than the longitudinal dimension of the nip plate 130, the heat insulating member 160, and the reflecting plate 140. The stay 150 is arranged so that both ends thereof protrude outward in the longitudinal direction from the nip plate 130, the heat insulating member 160, and the reflection plate 140.

  The inner surface F <b> 1 has a support portion F <b> 10 for supporting each upstream extending wall 145 and each downstream extending wall 147 of the reflecting plate 140. Specifically, the support portion F10 includes two planar upstream support portions F11 that support each upstream extension wall 145 and two planar downstream support portions F12 that support each downstream extension wall 147. ing. The upstream support portion F <b> 11 is disposed at both longitudinal ends of the upstream side wall portion 152. The downstream support portions F12 are disposed at both longitudinal ends of the downstream side wall portion 152.

  As shown in FIG. 4A, the upstream support portion F11 is formed with a columnar protrusion B1 as an example of a first protrusion and a second protrusion protruding from the upstream support portion F11 toward the inside in the transport direction. ing. In addition, a columnar protrusion B2 as an example of a first protrusion and a second protrusion protruding from the downstream support F12 inward in the transport direction is formed on the downstream support F12. The protrusions B1 and B2 are formed by embossing a part of the side wall 152 of the stay 150.

  The leaf spring 190 has a recessed shape that is recessed upward (on the opposite side of the stay 150 from the recessed portion 150 </ b> A), and is disposed at a position away from the nip plate 130 inside the endless belt 110. Specifically, the leaf springs 190 are provided at both ends in the longitudinal direction of the reflector 140 so as to cover part of both ends of the halogen lamp 120 from the opposite side of the stay 150 (see FIG. 3). The dimension in the longitudinal direction of the leaf spring 190 is less than half of the dimension in the longitudinal direction of the nip plate 130.

  The leaf spring 190 is in contact (direct contact) with the upstream extension wall 145 and the downstream extension wall 147 of the reflector 140 and pushes the upstream extension wall 145 and the downstream extension wall 147 toward the upstream side and the downstream side in the transport direction. A pressing portion 191 that spreads and presses each side wall portion 152 of the stay 150 is provided.

  Specifically, the pressing portion 191 includes an upstream pressing portion 191A that presses the upstream extending wall 145 of the reflecting plate 140 against the upstream supporting portion F11 (inner surface F1) of the stay 150, and the downstream extending wall 147 of the reflecting plate 140 that stays on the stay 150. A downstream pressing portion 191B that presses against the downstream support portion F12 (inner surface F1).

  The upstream pressing portion 191A has a through hole H3 as an example of a second opening portion into which the protrusion B1 formed on the upstream support portion F11 of the stay 150 is fitted. The downstream pressing portion 191B has a through hole H4 as an example of a second opening portion into which the protrusion B2 formed on the downstream support portion F12 of the stay 150 is fitted. Each through-hole H3, H4 is formed in a circular shape (see FIG. 3).

  As shown in FIG. 5, the side guide 180 is a member that guides the endless belt 110 and is disposed so as to sandwich the endless belt 110 in the longitudinal direction. The side guide 180 has a guide main body 181 for supporting the stay 150 and the like, and an inner peripheral guide 182 for guiding the inner peripheral surface 111 of the endless belt 110.

  The guide body 181 has a support recess 181A that opens toward the inside in the longitudinal direction, and the end of the stay 150 is fixed in the support recess 181A. Further, a metal plate (not shown) is provided in the support recess 181A, and the halogen lamp 120 is supported by the metal plate.

  The inner peripheral guide portion 182 is a wall having a circular arc shape in cross section that protrudes inward in the longitudinal direction from the inner surface in the longitudinal direction of the guide main body portion 181, and the outer peripheral surface guides the inner peripheral surface 111 of the endless belt 110. It is a surface 182A.

  Each side guide 180 is pressed downward by the compression coil spring SP. In this way, each side guide 180 is pressed by the compression coil spring SP, so that a downward pressing force acts on the stay 150, and this pressing force is transmitted via the heat insulating member 160, the nip plate 130 and the endless belt 110. It is transmitted to the pressure roller 170. Further, a reaction force against the pressing force is generated upward from the pressure roller 170, and this reaction force is received by the stay 150 via the endless belt 110, the nip plate 130 and the heat insulating member 160. .

  On the contrary, by pressing the pressure roller 170 upward by an elastic member such as a spring, the pressing force from the pressure roller 170 is passed through the endless belt 110, the nip plate 130, and the heat insulating member 160. You may comprise so that it may receive in stay 150.

Next, an assembling method (manufacturing method) of the fixing device 100, specifically, an assembling method of a structure arranged on the pressure roller 170 will be described.
As shown in FIGS. 3 and 4A, the reflector plate 140 is inserted inside the stay 150 so that the through holes H1 and H2 of the reflector plate 140 are fitted in the protrusions B1 and B2 of the stay 150, respectively. . Thereafter, the one leaf spring 190 is bent slightly inward so that the through holes H3 and H4 of the one leaf spring 190 are fitted in the protrusions B1 and B2 of the stay 150, and the inside of the reflector 140 is inserted. .

  Thereafter, when the finger is released from one of the leaf springs 190, the extending walls 145 and 147 of the reflecting plate 140 are pushed outward in the conveying direction by the urging force when the one leaf spring 190 returns to its original shape. The extended walls 145 and 147 are pressed against the support portions F11 and F12 of the stay 150. The other leaf spring 190 is assembled to the reflector 140 and the stay 150 in the same manner. As described above, the reflecting plate 140 is attached to the stay 150 in a state where the through holes H1 and H2 of the reflecting plate 140 and the projections B1 and B2 of the stay 150 are maintained by the urging force of the two leaf springs 190. Combined. In this specification, the term “coupled” includes coupling that maintains the positional relationship between the reflector 140 and the stay 150 when no force is applied to the reflector 140 or the stay 150. It also includes being held by the stay 150 with rattling. In addition, when the reflector is “coupled” to the stay by the spring, the elastic force (restoring force) of the reflector itself prevents the reflector from being fitted into each protrusion of the stay in the state where there is no spring. In the temporarily held configuration, the fitting is more reliably held by the elastic force of the spring, and the reflector and the stay are more reliably coupled.

  After the reflection plate 140 is coupled to the stay 150 by the leaf spring 190, the heat insulating member 160 is assembled to the stay 150, and the nip plate 130 is assembled to the heat insulating member 160. Accordingly, the plate spring 190, the reflecting plate 140, the stay 150, the heat insulating member 160, and the nip plate 130 are configured as one assembly. Thereafter, one end of the assembly in the longitudinal direction and one end of the halogen lamp 120 are attached to the side guide 180. Next, the assembly with the side guide 180 attached to one end is inserted into the endless belt 110, and the side guide 180 is attached to the other end in the longitudinal direction of the assembly protruding from the endless belt 110.

According to the above, the following effects can be obtained in the present embodiment.
The reflecting plate 140 can be coupled to the stay 150 by pressing the extension walls 145 and 147 of the reflecting plate 140 against the support portions F11 and F12 of the stay 150 by the plate spring 190. The screw for joining 150 can be eliminated. By eliminating the number of screws in this way, the connecting work between the reflector 140 and the stay 150 can be facilitated, and damage due to the face of the inner peripheral surface 111 of the endless belt 110 can be suppressed.

  Since the through holes H1 and H2 of the reflecting plate 140 are fitted into the protrusions B1 and B2 of the stay 150, the positional deviation of the reflecting plate 140 with respect to the stay 150 can be suppressed.

  Since the through holes H3 and H4 of the leaf spring 190 are fitted into the protrusions B1 and B2 of the stay 150, it is possible to suppress the leaf spring 190 from being detached from the stay 150.

  Since the upstream wall 141 is inclined at a predetermined inclination with respect to the upstream support portion F11 (vertical surface) along the substantially vertical direction, the upstream wall 141 can efficiently reflect the radiant heat. Further, since the amount of inclination of the upstream extension wall 145 with respect to the upstream support portion F11 is smaller than the amount of inclination of the upstream wall 141 with respect to the upstream support portion F11, specifically about 0 °, the upstream extension wall 145 and the upstream support portion. The contact area with F11 can be increased, and the upstream extension wall 145 can be favorably supported by the upstream support portion F11.

  Since the downstream wall 142 is inclined at a predetermined inclination with respect to the downstream support portion F12 (vertical surface) along the substantially vertical direction, the downstream wall 142 can efficiently reflect the radiant heat. In addition, since the amount of inclination of the downstream extension wall 147 with respect to the downstream support portion F12 is smaller than the amount of inclination of the downstream wall 142 with respect to the downstream support portion F12, specifically, approximately 0 °, the downstream extension wall 147 and the downstream support portion. The contact area with F12 can be increased, and the downstream extension wall 147 can be favorably supported by the downstream support portion F12.

  Since the leaf spring 190 covers a part of the halogen lamp 120 from the side opposite to the stay 150, it is possible to suppress the temperature at each end of the endless belt 110 from becoming higher than the central portion. Further, since the leaf spring 190 biases the extending walls 145 and 147 of the reflecting plate 140 so as to spread, the leaf spring can be obtained without providing the projections B1 and B2 and the through holes H1 to H4 of the present embodiment, for example. The reflector 140 can be coupled to the stay 150 with only the urging force 190.

  In addition, this invention is not limited to the said embodiment, It can utilize with various forms so that it may illustrate below. In the following description, the same reference numerals are given to members having substantially the same structure as in the above embodiment, and the description thereof is omitted.

  In the above embodiment, the lower end of the upstream extension wall 145 and the lower end of the downstream extension wall 147 are connected to the central wall 143. However, the present invention is not limited to this, for example, as shown in FIG. The wall 145 and the downstream extension wall 147 may be separated from the central wall 243. Specifically, in this structure, the central wall 243 is formed from the end portion on the outside in the longitudinal direction of one upstream intermediate wall 144 to the end portion on the outside in the longitudinal direction of the other upstream intermediate wall 144 (not shown). .

  According to this, since the upstream extension wall 145 and the downstream extension wall 147 are easily deformed by being separated from the central wall 243, the upstream extension wall 145 and the downstream extension wall 147 are stayed by the leaf spring 190. It can press well to each support part F11, F12 of 150. In addition, the structure which isolate | separates each extension wall from a center wall is not restricted to the structure of FIG. 6, A various structure is employable. For example, each extending wall may be separated (separated) from the central wall together with each intermediate wall by forming the central wall from one end to the other end in the longitudinal direction of the upstream wall. 3, a slit is formed between the upstream extending wall 145 and the central wall 143, or between the downstream extending wall 147 and the central wall 143, and the extending walls 145 and 147 are arranged in the center. It may be separated from the wall 143. In this case, the extended walls 145 and 147 may be in contact with the central wall 143. That is, it is only necessary that the extending walls 145 and 147 can be deformed independently of the central wall 143.

  In the above embodiment, the cylindrical protrusions B1 and B2 are exemplified as the protrusions, but the present invention is not limited to this, and the protrusions are elongated in the longitudinal direction of the halogen lamp 120, for example, as shown in FIG. It may be protrusions B3 and B4. The protrusions B3 and B4 protrude from the support portions F11 and F12 of the stay 150 to the inside in the transport direction, and the dimensions in the left-right direction are larger than the dimensions in the up-down direction and the front-rear direction (transport direction). In this structure, the through holes H5 and H6 of the reflecting plate 140 and the through holes H7 and H8 of the leaf spring 190 are formed so as to be elongated in the longitudinal direction according to the shape of the protrusions B3 and B4. do it.

  According to this, since the projections B3 and B4 are elongated in the longitudinal direction of the halogen lamp 120, the reflector 140 or the leaf spring 190 is perpendicular to the longitudinal direction with respect to the stay 150, specifically in the vertical direction. It is possible to satisfactorily suppress movement.

  In the above-described embodiment, the plate spring 190 is disposed so as to have a concave shape that is recessed to the opposite side of the concave portion 150A of the stay 150. However, the present invention is not limited to this, and for example, as shown in FIG. May be arranged so as to form a concave shape that is recessed to the same side as the concave portion 150 </ b> A of the stay 150.

  Even in this embodiment, the extending walls 145 and 147 of the reflector plate 140 can be pushed outwardly in the conveying direction by the urging force of the leaf spring 190 and pressed against the support portions F11 and F12 of the stay 150. The same effect can be obtained.

  In the above-described embodiment, the number of screws for connecting the reflector 140 and the stay 150 is set to 0. However, the present invention is not limited to this, and the number is less than that of the conventional example, for example, about 1 or 2 screws. In addition, a screw for connecting the reflecting plate 140 and the stay 150 may be provided.

  The shapes of the reflecting member, the stay, and the leaf spring are not limited to the above embodiment, and may be, for example, a shape as shown in FIG. Specifically, in the structure shown in FIG. 9, a flange portion 153 as an example of a support portion is formed at the upper end of each side wall portion 152 of the stay 150 and extends outward in the transport direction.

  The reflecting plate 240 as an example of the reflecting member includes a base portion 241 having a concave shape that is recessed to the opposite side of the concave portion 150A of the stay 150, and extending from each end of the base portion 241 in the transport direction toward the outside in the transport direction. And a flange portion 242 as an example of a support portion. The leaf spring 290 has a U shape in a sectional view, and includes a pressing portion 291 that contacts the flange portion 242 of the reflecting plate 240 from above, an engaging portion 292 that contacts the flange portion 153 of the stay 150 from below, and a pressing portion 291. And a connecting portion 293 that connects each end portion of the engaging portion 292 on the outer side in the transport direction.

  Even in this structure, since the pressing portion 291 presses the flange portion 242 of the reflecting plate 240 against the flange portion 153 of the stay 150, the same effect as in the above embodiment can be obtained.

  Note that the shape of the stay does not have to be a U shape in a sectional view, and may be a rectangular plate shape, for example. In the embodiment, each side wall 152 of the stay 150 is formed along the vertical direction, but each side wall may be inclined with respect to the vertical direction.

  In the embodiment, the protrusions B1 and B2 are formed by embossing. However, the present invention is not limited to this, and for example, as shown in FIG. 10, a part of the side wall 152 of the stay 150 is formed using a press die. The protrusions B5 and B6 may be formed by cutting and raising. As other processing methods, for example, burring or casting may be employed. For example, as shown in FIG. 11, the cylindrical protrusions B7 and B8 may be formed as convex portions by burring a part of the side wall portion 152 of the stay 150. In other words, the protrusions B7 and B8 have through holes B71 and B72 that penetrate in the protruding direction of the protrusions B7 and B8.

  In the said embodiment, although the leaf | plate spring 190 was illustrated as a spring, this invention is not limited to this, For example, a compression coil spring, a wire spring, etc. may be sufficient.

  In the embodiment, the halogen lamp 120 is exemplified as an example of the heater, but the present invention is not limited to this, and the heater may be a carbon heater or the like.

  In each of the embodiments, the plate-shaped nip plate 130 is illustrated as an example of the nip member. However, the present invention is not limited to this, and the nip member may be, for example, a thick pad member or block member that is not plate-shaped. Good. Further, a sliding sheet for smooth sliding of the endless belt with respect to the nip member may be interposed between the nip member and the inner peripheral surface of the endless belt. In this case, the sliding sheet is, for example, a woven sheet and may be attached to the nip member. Further, in this case, the nip member may be a plate member made of resin.

  The reflecting plate 140 may also be a thick reflecting member instead of a plate-like member. Furthermore, the reflecting plate may be disposed so as to reflect the radiant heat toward the nip plate. The stay supports the nip member via the heat insulating material, but may support the nip member directly.

  In the above embodiment, the present invention is applied to the color laser printer 1, but the present invention is not limited to this, and the present invention may be applied to other image forming apparatuses such as a copying machine and a multifunction machine.

  In the embodiment, the pressure roller 170 is exemplified as a backup member that sandwiches the endless belt with the nip member. However, the present invention is not limited to this, and may be a belt-like pressure member, for example. .

  In the embodiment, the paper 51 such as a thick paper, a postcard, and a thin paper is exemplified as an example of the recording sheet. However, the present invention is not limited to this, and may be an OHP sheet, for example.

  In the said embodiment, although protrusion B1, B2 was illustrated as a 1st convex part and a 2nd convex part, this invention is not limited to this. For example, a first protrusion that fits in the through holes H1 and H2 of the reflector plate 140 and a second protrusion that fits in the through holes H3 and H4 of the leaf spring 190 are formed on the stay 150 as separate protrusions. May be.

  In the said embodiment, although the through-holes H1-H4 were illustrated as a 1st opening part and a 2nd opening part, this invention is not limited to this, A 1st opening part and a 2nd opening part are one of the periphery of a hole. It may be a notch or the like in which the part opens to the outside. Further, an opening may be formed in the stay, and a convex portion that engages with the opening may be provided on the reflecting member or the spring. Specifically, for example, in the case where an opening is formed in the stay and a convex portion that fits into the opening of the stay is provided in the reflecting member, a structure that does not form the opening or the convex portion in the spring is adopted. be able to. Further, for example, an opening may be formed in the stay and the reflecting member, and a convex portion that fits into the opening of the stay and the opening of the reflecting member may be provided on the spring.

  In the said embodiment, although the spring was arrange | positioned inside the endless belt, this invention is not limited to this, The spring may be arrange | positioned outside the endless belt.

51 Paper 100 Fixing device 110 Endless belt 120 Halogen lamp 130 Nip plate 140 Reflecting plate 145 Upstream extending wall 147 Downstream extending wall 150 Stay 170 Pressure roller 190 Leaf spring 191 Pressing portion F11 Upstream supporting portion F12 Downstream supporting portion NP Nip portion

Claims (17)

Endless belt,
A heater disposed inside the endless belt;
A reflective member that is disposed inside the endless belt and reflects radiant heat from the heater;
A stay arranged inside the endless belt;
A nip member disposed inside the endless belt;
And a backup member that sandwiches the endless belt with the nip member and forms a nip portion with the endless belt, and is a fixing device that conveys a recording sheet in the predetermined conveyance direction at the nip portion. And
The reflection member has a supported portion supported by the support portion of the stay,
A fixing device further comprising a spring disposed inside the endless belt and having a pressing portion that presses the supported portion against the supporting portion of the stay. A first convex portion is formed on the support portion of the stay,
The supported portion of the reflective member is formed with a first opening that fits with the first convex portion,
The fixing device according to claim 1, wherein the supported portion of the reflecting member is pressed against the support portion of the stay by the pressing portion of the spring. A second convex part is formed on the support part of the stay,
The spring is a leaf spring;
The fixing device according to claim 1, wherein the pressing portion of the leaf spring has a second opening portion into which the second convex portion is fitted.   The fixing device according to claim 2, wherein the convex portion is elongated in a longitudinal direction of the heater.   The fixing device according to claim 2, wherein the convex portion has a through-hole penetrating in a protruding direction of the convex portion. The reflective member includes an upstream wall, a downstream wall disposed at a distance downstream from the upstream wall in the transport direction, and a central wall that connects ends of the upstream wall and the downstream wall; And forming an elongated recess in the longitudinal direction of the heater with the upstream wall, the downstream wall, and the central wall,
The reflective member further includes an upstream extending wall that is connected to one end of the upstream wall in the longitudinal direction and separated from the central wall,
The upstream extension wall has the supported portion,
The support portion of the stay has an upstream support portion that supports the upstream extension wall,
6. The fixing according to claim 1, wherein the pressing portion of the spring includes an upstream pressing portion that presses the upstream extending wall against the upstream support portion of the stay. apparatus. The reflective member further includes a downstream extension wall connected to one end portion of the downstream wall in the longitudinal direction and separated from the central wall,
The downstream extension wall has the supported portion,
The support portion of the stay has a downstream support portion that supports the downstream extension wall,
The fixing device according to claim 6, wherein the pressing portion of the spring includes a downstream pressing portion that presses the downstream extending wall against the downstream support portion of the stay. The reflective member includes an upstream wall, a downstream wall disposed at a distance downstream from the upstream wall in the transport direction, and a central wall that connects ends of the upstream wall and the downstream wall; And forming an elongated recess in the longitudinal direction of the heater with the upstream wall, the downstream wall, and the central wall,
The reflective member further includes a downstream extension wall connected to one end portion of the downstream wall in the longitudinal direction and separated from the central wall,
The downstream extension wall has the supported portion,
The support portion of the stay has a downstream support portion that supports the downstream extension wall,
6. The fixing according to claim 1, wherein the pressing portion of the spring includes a downstream pressing portion that presses the downstream extending wall against the downstream support portion of the stay. 7. apparatus. The upstream wall is inclined toward the downstream side in the transport direction as it approaches the central wall,
The fixing device according to claim 6, wherein the upstream extension wall has a smaller amount of inclination of the stay with respect to the upstream support portion than the upstream wall. The downstream wall is inclined toward the upstream side in the transport direction as it approaches the central wall,
9. The fixing device according to claim 7, wherein the downstream extension wall is smaller in inclination amount with respect to the downstream support portion of the stay than the downstream wall. The stay has an inner surface that forms a recess that is elongated in the longitudinal direction of the heater,
The inner surface of the stay has the support part,
11. The fixing according to claim 1, wherein the pressing portion of the spring presses the supported portion of the reflecting member against the supporting portion of the inner surface of the stay. 11. apparatus.   The spring has a concave shape that is recessed toward the opposite side of the concave portion of the stay, covers a part of the heater from the opposite side of the stay, and the supported portion of the reflecting member is located upstream in the transport direction. The fixing device according to claim 11, wherein the fixing device presses against the support portion of the stay by spreading and downstream.   The spring has a concave shape that is recessed to the same side as the concave portion of the stay, and pushes the supported portion of the reflecting member to the upstream side and the downstream side in the transport direction to press the support portion of the stay. The fixing device according to claim 11. The reflective member is disposed between the heater and the nip portion,
14. The fixing according to claim 1, wherein the reflection member is disposed so as to reflect radiant heat from the heater toward an inner peripheral surface of the endless belt. apparatus.   The fixing device according to claim 1, wherein the spring is separated from the nip member.   The fixing device according to claim 1, wherein a dimension of the spring in the longitudinal direction of the heater is less than half of a dimension of the nip member in the longitudinal direction. Connecting the reflecting member and the stay with a spring;
A method of manufacturing a fixing device, comprising: a step of inserting a reflecting member coupled with a spring and a stay into an endless belt.

Images