JP6253322B2 - Fixing device - Google Patents

Description

The present invention, copiers, printers, facsimile relates to a preferred fixing apparatus used in an image forming apparatus such as a multifunction peripheral having a plurality of functions of these.

  In recent years, as devices have become smaller, the drive unit for driving each module is required to be smaller than before, and moreover, a drive capable of performing a plurality of operations from the same drive source is required. Yes. For example, a configuration having one oscillating rotating body that meshes with a driving gear as a driving rotating body driven by a drive source capable of rotating in the forward and reverse directions and swings in accordance with the rotation direction of the driving gear is conventionally known. (For example, Patent Document 1). In this configuration, the path through which the drive is transmitted from the motor to one of the two gear trains (drive paths) is switched by swinging the swing gear.

JP 2012-200909 A

  In the case of the configuration having one swing gear as described above, the drive path can be switched by two gear trains, and switching to more drive paths cannot be performed.

  Here, it is conceivable to use a one-way clutch to switch the drive path. For example, a plurality of input gears are connected around the drive gear. Each input gear is provided with an output gear coaxially via a one-way clutch, and a gear train is connected to each output gear. When the drive gear is rotated in a predetermined direction, power is transmitted from one of the input gears to the gear train via the one-way clutch and the output gear, and the one-way clutch is used between the other input gears and the output gear. The drive transmission is cut off. As a result, the drive path can be switched according to the rotation direction of the drive gear.

However, in such a configuration using the one-way clutch, that Do need two gears and an output gear and the input gear in each drive path.

In view of such circumstances, the present invention has been invented to realize a configuration capable of switching to a plurality of drive paths.

The fixing device according to the present invention forms a first rotating body and a nip portion for fixing a toner image on the recording material while conveying the recording material in cooperation with the first rotating body. A toner image can be fixed to the first rotating body and the second rotating body by pressurizing at least one of the rotating body, the first rotating body, and the second rotating body toward the other. A pressure member capable of taking a first position where the nip portion is formed and a second position where the nip portion is released with respect to the first position; and the second position from the first position to the second position. A moving mechanism for moving the pressure member so as to be in the position, a transport rotating body for transporting the recording material transported from the nip portion, a drive gear, the drive gear, the first direction, and the first A drive source that can be driven to rotate in a second direction opposite to the direction of 1, and the rotation of the drive gear. A swing gear that swings by the first gear, and a first swing position that transmits the rotational driving force of the drive gear to the rotation of the first rotating body by meshing with the first gear, and the first gear A first oscillating gear that oscillates so as to be able to assume a second oscillating position where the rotational driving force of the driving gear is not transmitted to the rotation of the first rotating body by disengaging the gear. A third oscillating gear that oscillates by rotation of the drive gear, wherein the third oscillating position transmits the rotational driving force of the drive gear to the rotation of the conveying rotator by meshing with the second gear; A second oscillating gear that oscillates so as to obtain a fourth oscillating position that engages with a third gear to transmit the rotational driving force of the drive gear to the moving mechanism, and In conjunction with rotation of the drive gear in the first direction, the first swing gear is While the rotational driving force of the drive gear is transmitted to the rotation of the first rotating body at the first swing position, the second swing gear is the rotational driving force of the drive gear at the third swing position. Is transmitted to the rotation of the transport rotating body, and in conjunction with the drive gear rotating in the second direction, the first swing gear is positioned at the second swing position, the second swing gear to transmit the rotational driving force of said driving gear at a rocking position of the fourth to the moving mechanism, it you characterized.

According to the present invention, substantially simultaneously performed switching to the drive path to be the same timing, because the first swing gear and the second swing gear is swung by the rotation of the drive gear Switching to a plurality of drive paths can be performed at an appropriate timing . Further, it is possible to eliminate the need to provide a one-way clutch for switching these drive paths.

1 is a schematic cross-sectional view of an image forming apparatus according to a first embodiment of the present invention. 1 is a schematic cross-sectional view of a fixing device according to a first embodiment. FIG. 3 is a cross-sectional view illustrating a pressure release mechanism of the fixing device according to the first embodiment. FIG. 3 is a perspective view illustrating a state in which the fixing device according to the first embodiment is mounted on the apparatus main body. FIG. 3 is an exploded perspective view illustrating a part of the fixing device according to the first embodiment. 1 is a perspective view of a drive switching device according to a first embodiment. The perspective view of the drive switching device seen from the back side of FIG. (A) An exploded perspective view of a swing gear, (b) a plan view of the swing gear. The top view which shows the structure of the stopper part which controls rocking | fluctuation of a rocking | fluctuation gear. The top view which shows the positional relationship of each gear in the drive switching apparatus which concerns on 1st Embodiment at the time of (a) normal rotation of a motor, and (b) reverse rotation of a motor. The top view which expands and shows the drive gear periphery of a drive switching device in order to demonstrate operation | movement of a rocking | fluctuation gear, respectively at the time of (a) normal rotation of a motor, and (b) reverse rotation of a motor. The top view which shows the positional relationship of each gear in the drive switching apparatus which concerns on the 2nd Embodiment of this invention at the time of (a) normal rotation of a motor, and (b) reverse rotation of a motor. The top view of the drive switching apparatus which concerns on the 3rd Embodiment of this invention.

<First Embodiment>
A first embodiment of the present invention will be described with reference to FIGS. First, a schematic configuration of the image forming apparatus of the present embodiment will be described with reference to FIG.

[Image forming apparatus]
The image forming apparatus 10 of the present embodiment is a full color printer that employs an electrophotographic system. Such an image forming apparatus 10 includes an image forming unit 11 that forms a toner image, and a recording material transport unit 12 that transports a recording material to which a toner image formed by the image forming unit 11 is transferred. Examples of the recording material include a sheet material such as a transfer sheet, electrofax sheet, electrostatic recording paper, OHP sheet, printing paper, and format paper. The image forming unit 11 has a so-called tandem configuration in which a plurality of image forming stations 1 a, 1 b, 1 c, and 1 d are arranged in the running direction of the intermediate transfer belt 13. In each of the image forming stations 1a, 1b, 1c, and 1d, yellow, magenta, cyan, and black toner images are formed, respectively. In the present embodiment, each of the image forming stations 1a, 1b, 1c, and 1d is constituted by a process cartridge.

  Each image forming station forms a toner image as follows. First, the surface of the photosensitive drum 14 is charged by a charging device such as a charging roller, and an electrostatic latent image is formed by exposing the charged surface of the photosensitive drum 14 by a laser according to image information by the exposure device 15. . Next, the electrostatic latent image is developed with toner by a developing device, thereby forming a toner image on the surface of the photosensitive drum 14.

  The toner image formed on the surface of the photosensitive drum 14 of each image forming station is sequentially transferred to the intermediate transfer belt 13 by the primary transfer unit T1, and a full-color toner image is formed on the intermediate transfer belt 13. It is formed. In the primary transfer portion T1, a primary transfer roller 16 is disposed as a primary transfer portion that is disposed to face the photosensitive drum 14 and the intermediate transfer belt 13 therebetween. A toner image on the photosensitive drum 14 is transferred to the intermediate transfer belt 13 by applying a primary transfer bias between the primary transfer roller 16 and the photosensitive drum 14.

  The toner image on the intermediate transfer belt 13 is transferred to the recording material P conveyed by the recording material conveyance unit 12 at the secondary transfer unit T2. In the secondary transfer portion T2, a secondary transfer inner roller 17a and a secondary transfer outer roller 17b are disposed so as to face each other with the intermediate transfer belt 13 therebetween. The toner image on the intermediate transfer belt 13 is transferred to the recording material P by applying a secondary transfer bias between the secondary transfer inner roller 17a and the secondary transfer outer roller 17b. The recording material P to which the toner image has been transferred is heated and pressed by a fixing device 100 as a heating device, whereby the toner image is fixed. Details of the fixing device 100 will be described later. The recording material P on which the toner image is fixed is discharged to a discharge tray 19 by a discharge roller 18.

  The recording material conveyance unit 12 includes a plurality of conveyance rollers. The recording material P accommodated in the cassette 20 is picked up by the pickup roller 21 and conveyed to the conveyance path 22. The recording material P transported to the transport path 22 is transported to the secondary transfer section T2 in synchronization with the toner image formed on the image forming section 11 by the registration roller pair 23. Further, the recording material P discharged from the fixing device 100 is discharged to the discharge tray 19 as described above, and is reversed and conveyed to the reverse conveyance path 30 to perform duplex printing. The recording material P transported through the reverse transport path 30 joins the transport path 22 and is transported to the secondary transfer portion T2 as described above.

  In the case of the present embodiment, an opening / closing door 25 is provided in an openable / closable manner on the apparatus main body 24 in which various apparatuses as described above are arranged. The open / close door 25 is provided on the side on which the conveyance path 22 and the fixing device 100 are arranged so as to be rotatable about a rotation shaft 26. By opening the opening / closing door 25, the fixing device 100 and the conveyance path 22 are exposed, and the fixing apparatus 100 can be attached and detached and the recording material jammed in the conveyance path 22 can be removed. For this purpose, the fixing device 100 is detachably attached to the apparatus main body 24. Further, a roller on one side of a pair of conveyance rollers such as the registration roller pair 23 arranged in the conveyance path 22 and a secondary transfer outer roller 17b constituting the secondary transfer portion T2 are provided on the opening / closing door 25 side. . When the open / close door 25 is opened, it is separated from the opposing roller and the intermediate transfer belt 13.

[Fixing device]
Next, details of the fixing device 100 as the heating device of the present embodiment will be described with reference to FIGS. 2 and 3. The fixing device 100 includes a fixing film 101 as a rotating body, and a counter roller 102 that is disposed to face the fixing film 101 as a nip forming member. A nip portion N for nipping and conveying the recording material is formed between the fixing film 101 and the opposing roller 102, and a toner image formed on the recording material passing through the nip portion N by a heater 104 as a heating source is formed. Heat. The nip portion N can be released from pressure by the pressure release mechanism 103. Further, the recording material that has passed through the nip portion N is discharged from the fixing device 100 by a discharge portion 400 as discharge means (see FIG. 1). The discharge unit 400 includes a pair of discharge rollers 401 and 402 as shown in FIG.

  The fixing film 101 is a cylindrical heat-resistant member in which an elastic layer is formed on a cylindrical thin metal base layer. The fixing film 101 is loosely fitted on a track regulating member 105 disposed at both ends of the fixing film 101. It is. Such a fixing film 101 has a film thickness of 100 μm or less, preferably 20 μm or more and 50 μm or less in order to reduce the heat capacity and improve the quick start property. The fixing film 101 may be a base layer made of a metal such as SUS or a single layer film made of heat-resistant PTFE, PFA, or FEP. Alternatively, a composite layer film in which the base layer is made of polyimide, polyamideimide, PEEK, PES, PPS, or the like and the outer peripheral surface thereof is coated or covered with PTFE, PFA, FEP, or the like may be used.

  The opposing roller 102 is composed of a cored bar made of metal such as iron, and a heat-resistant / elastic material layer such as silicone rubber, fluororubber, and fluororesin that is concentrically formed and coated around the cored bar. A release layer is provided on the surface layer. For example, the release layer may be made of a material having good release properties and heat resistance such as fluororesin, silicone resin, fluorosilicone rubber, fluororubber, silicone rubber, PFA, PTFE, FEP. A pressure member support member (not shown) made of a heat resistant resin such as PEEK, PPS, or liquid crystal polymer is attached to both ends of the core metal, and is supported rotatably. Further, the opposing roller 102 is driven via a drive switching device 130 by a motor 131 as a drive source (described later) provided in the apparatus main body 24. The fixing film 101 is driven to rotate by rotating the counter roller 102, and conveys the recording material sandwiched by the nip portion N.

  As described above, the track regulating member 105 that externally fits both ends of the fixing film 101 is a member made of heat-resistant resin such as PET, PPS, or LCP. Such a trajectory regulating member 105 is movably supported on the side plate of the fixing device 100, supports the fixing film 101 so as to be rotatable, and is disposed in the case of the fixing device 100. The track regulating member 105 guides the rotation of the fixing film 101 and functions as an abutting portion in the longitudinal direction of the fixing film 101 (direction intersecting the recording material conveyance direction at the nip portion N).

  Inside the fixing film 101, stays 106 are arranged in the longitudinal direction, and both ends of the stays 106 are supported by the track regulating member 105. Such a stay 106 is a member mainly made of metal such as iron or SUS. A pressure contact member 107 is disposed on the opposite roller 102 side of the stay 106. Then, the stay 106 is pressed against a relatively soft pressure contact member 107 made of resin, so that the pressure contact member 107 has strength in the longitudinal direction (direction intersecting the recording material conveyance direction at the nip portion N) and is pressed. The member 107 is corrected.

  The pressure contact member 107 is a heat-resistant and heat-insulating member having a substantially semicircular cross section. For example, it is formed of a material having good insulation and heat resistance such as phenol resin, polyimide resin, polyamide resin, polyamideimide resin, PEEK resin, PES resin, PPS resin, PFA resin, PTFE resin, and LCP resin. The pressure contact member 107 backs up the fixing film 101, pressurizes the nip portion N formed by pressure contact with the opposing roller 102 via the fixing film 101, and transport stability during rotation of the fixing film 101. To play a role.

  The pressure contact member 107 supports a ceramic heater (hereinafter referred to as a heater) 104 as a heating source. The heater 104 is fitted and supported in a groove formed along the longitudinal direction on the surface of the pressure contact member 107 on the nip portion N side. The heater 104 is basically composed of a long and thin plate-like ceramic substrate and an energization heating resistor layer provided on the surface of the substrate, and the temperature rises with a steep rise characteristic as a whole by energizing the heating resistor layer. It is a low heat capacity heater.

  In the present embodiment, the nip portion N is formed by pressing the fixing film 101 toward the opposing roller 102 by the pressing member 108. As shown in FIG. 3, such a pressure member 108 stretches a spring 109 as a pressure elastic member, and presses (presses) the track regulating member 105 in the direction of the opposing roller 102 by the elastic force of the spring 109. ) Therefore, the pressure member 108 presses the pressure contact member 107 toward the opposing roller 102 via the track regulating member 105 and the stay 106. When the pressure contact member 107 is pressed, the above-described nip portion N is formed between the fixing film 101 and the opposing roller 102.

  The pressure release mechanism 103 moves the pressure member 108 as described above to switch the nip portion N between a pressure state and a pressure release state. Such a pressure release mechanism 103 includes a cam 103 a and a cam contact surface 103 b that comes into contact with the cam surface of the cam 103 a formed on the pressure member 108. The cam 103a is driven via a drive switching device 130 by a motor 131, which will be described later, provided in the apparatus main body 24, and the cam surface is brought into contact with or separated from the cam contact surface 103b of the pressurizing member 108. Pressurization and release of the nip N are performed.

  At the time of pressurization of the nip portion N, as shown in FIG. 3, the phase of the cam 103a is set so that the cam contact surface 103b of the pressurizing member 108 does not contact the cam surface of the cam 103a. As a result, the pressing member 108 presses the track regulating member 105 by the elastic force of the spring 109, and the nip portion N is pressed.

  On the other hand, when the pressure is released, the cam 103a rotates approximately 180 ° from the state shown in FIG. 3, the cam surface of the cam 103a comes into contact with the cam contact surface 103b of the pressure member 108, and the pressure member 108 is moved to the spring 109. Push up against the elastic force. Thereby, the pressurization of the nip portion N is released.

  As shown in FIG. 4, the fixing device 100 configured as described above is mounted on the apparatus main body 24 and driven by the drive switching device 130. The drive switching device 130 is provided in the vicinity of the fixing device 100 attached to the device main body 24, and is connected to a gear as each drive unit provided in the fixing device 100 when the fixing device 100 is attached to or detached from the device main body 24. Or separate. That is, as shown in FIG. 5, the fixing device 100 includes gears 142, 143, and 144 as drive units. The gear 142 is a conveyance driving unit that transmits driving force to the opposing roller 102 as a member that conveys the recording material at the nip portion N. The gear 143 is a pressure release driving unit that transmits driving to the cam 103 a of the pressure release mechanism 103. The gear 144 is a discharge drive unit that transmits driving to the discharge roller 401 of the discharge unit 400. These gears 142, 143, and 144 are connected to each drive path of the drive switching device 130 described below so as to be able to transmit the drive, and the drive is transmitted according to the operation of the drive switching device 130.

[Drive switching device]
Next, the drive switching device 130 will be described with reference to FIGS. The drive switching device 130 includes a motor 131 as a drive source, a drive gear 132 as a drive rotator, a first swing gear 133 and a second swing gear 134 as a plurality of swing rotators, and a plurality of drives. And each gear train as a path. Further, the drive switching device 130 has a box-shaped first frame 151 as shown in FIG. In the illustrated example, one side of the first frame 151 is opened, but in actual use, the open side of the first frame 151 is covered with a flat second frame 152 as shown in FIG. And each gear mentioned later is arrange | positioned between the 1st flame | frame 151 and the 2nd flame | frame 152, and the both ends of the rotating shaft of a gear are rotatably supported by these each flame | frame, respectively.

  The motor 131 is a DC brushless motor capable of rotating in the forward and reverse directions, and is positioned and fixed with respect to the back side of the first frame 151 (the side opposite to the second frame 152). Such a motor 131 is driven to rotate by being fed from a power source (not shown). The motor 131 is not limited to a DC brushless motor, and may be another motor such as a stepping motor as long as it can rotate forward and backward.

  As shown in FIG. 6, the drive gear 132 is rotatably supported on the open side of the first frame 151. As shown in FIGS. 10 and 11 to be described later, such a drive gear 132 is rotationally driven by the motor 131 with the peripheral surface of the motor 131 meshing with an output shaft 131a processed into a gear shape. Note that the output shaft 131a may be one in which the peripheral surface is not processed into a gear shape, and the gear is fixed to the shaft by press fitting or the like.

  The first oscillating gear 133 as the first oscillating rotator and the second oscillating gear 134 as the second oscillating rotator are meshed with (in contact with) the drive gear 132 and driven to rotate. Each of the drive gears 132 swings around the rotation center according to the rotation direction. In the present embodiment, the first oscillating gear 133 and the second oscillating gear 134 have the same rotation radius that oscillates around the rotation center of the drive gear 132. That is, the first oscillating gear 133 and the second oscillating gear 134 oscillate on the same circle α around the rotation center of the drive gear 132 as shown in FIGS.

[Oscillating gear]
Here, the structure of the 1st rocking gear 133 and the 2nd rocking gear 134 is demonstrated using FIG. The first swing gear 133 and the second swing gear 134 have the same configuration. As shown in FIG. 8A, the first swing gear 133 (second swing gear 134) includes a gear member 139, a holder member 140, and an elastic member 141.

  The gear member 139 is formed in a cylindrical shape, has gear teeth formed on the outer peripheral surface thereof, and meshes with an adjacent gear such as the drive gear 132. In the present embodiment, the first rocking gear 133 and the second rocking gear 134 use the same gear member 139, so that the modules and the number of teeth are the same.

  The holder member 140 is inserted into the gear member 139 and rotatably supports the gear member 139. Specifically, the inner peripheral surface of the gear member 139 has a stepped shape in which the large diameter portion and the small diameter portion are arranged in the axial direction. As shown in FIG. A rib 140c having a circular contour shape provided on the holder member 140 is fitted into the surface 139a. As a result, the gear member 139 is rotatably supported by the rib 140c.

  The elastic member 141 is configured by a leaf spring, and as shown in FIG. 8B, one end is fixed to the holder member 140 and the other end is an arrow on the inner peripheral surface 139 b of the large diameter portion of the gear member 139. It is made to contact | abut in the state elastically biased to the F direction. Then, when the gear member 139 is swung, a rotation load is applied to the gear member 139 to generate a swinging force on the first swinging gear 133 (second swinging gear 134).

  The holder member 140 is formed with a long hole portion 140a that penetrates in the axial direction of the gear member 139 and is long in a direction perpendicular to the axial direction. As shown in FIG. 6, the holder member 140 can move in the direction perpendicular to the shaft 151 a with respect to the first frame 151 by passing the shaft 151 a protruding from the first frame 151 through the long hole portion 140 a. Retained.

  When the driving gear 132 rotates, the rotational driving force is transmitted to the gear member 139 that meshes with the driving gear 132. Since the gear member 139 is given a rotational load by the elastic member 141, when the gear member 139 is rotating, a force that pushes the tooth surface according to the rotational load from the drive gear 132 that rotationally drives the gear member 139. This is a swinging force that causes a swinging motion. The swinging force causes the holder member 140 to move due to the engagement between the long hole portion 140a and the shaft 151a, and the gear member 139 supported by the holder member 140 also moves in the same direction. As a result, the first oscillating gear 133 (second oscillating gear 134) is oscillated by the rotation of the drive gear 132.

  Further, as shown in FIG. 8A, the holder member 140 is provided with a protruding portion 140b. As shown in FIG. 9, the protruding portion 140b is formed in the restriction groove 152a formed in the second frame 152. I try to enter. The restricting groove 152a restricts the swing range of the first swing gear 133 (second swing gear 134) by engagement with the protrusion 140b. Therefore, the first swing gear 133 (second swing gear 134) does not swing any further when the protrusion 140b hits a part of the restriction groove 152a. Thereafter, the gear member 139 rotates at the position about the rib 140c provided on the holder member 140 as a rotation axis regardless of the rotational load of the elastic member 141. In the case of the present embodiment, the first swing gear 133 and the second swing gear 134 have the same swing range restricted by the restriction groove 152a, so that the respective swing distances, that is, the centers of the respective swing gears are the same. The moving distance is the same.

[Drive path]
Further, the drive switching device 130 has a plurality of drive paths as shown in FIGS. 6 and 10. That is, the first gear train 138a serving as a first drive path transmitted from the first swing gear 133, the second gear train 138b serving as a second drive path transmitted from the second swing gear 134, and the third A third gear train 138c is provided as a drive path. In each of these gear trains, the first oscillating gear 133 and the second oscillating gear 134 are oscillated to transmit and disconnect the driving force, respectively. That is, the drive switching device 130 switches the path through which the drive from the motor 131 is transmitted to each gear train.

[Switch drive path]
Next, such switching of drive paths will be described with reference to FIGS. As shown in FIG. 10A, when the output shaft 131a of the motor 131 is rotated in the direction of arrow A (hereinafter referred to as forward rotation), the drive gear 132 is rotationally driven by the output shaft 131a in a predetermined direction (arrow B direction). Is done. Then, the rotational driving force is transmitted to the first oscillating gear 133 and the second oscillating gear 134 that mesh with the driving gear 132, respectively.

  At this time, since the rotational load is applied to the first swing gear 133 by the elastic member 141 described above, a force is applied in the direction of arrow C during driving rotation. As a result, the first swing gear 133 starts swinging in the direction of arrow P1 around the drive gear 132 from the position shown in FIG. 11A and moves to the position shown by the solid line in FIG. To do. What is indicated by a two-dot chain line in FIG. 11B represents the position before the swinging operation.

  At the same time, the second oscillating gear 134 receives a force in the direction of the arrow D as shown in FIG. 10A when the drive gear 132 is rotationally driven in a predetermined direction. As a result, the second swing gear 134 starts swinging in the direction of arrow P2 around the drive gear 132 from the position shown in FIG. 11A, and moves to the position shown by the solid line in FIG. To do. What is indicated by a two-dot chain line in FIG. 11B represents the position before the swinging operation.

  By such a swinging operation, as shown in FIG. 10A, the first swinging gear 133 meshes with (in contact with) the idler gear 135 of the first gear train 138a, and drives the first gear train 138a. introduce. At the same time, the second swing gear 134 meshes with (in contact with) the idler gear 136 of the second gear train 138b, and transmits the drive to the second gear train 138b.

  On the other hand, as shown in FIG. 10B, when the output shaft 131a of the motor 131 is rotated in the direction opposite to the normal rotation (direction of arrow E) (hereinafter, reverse rotation), the drive gear 132 is connected to the output shaft 131a. Is rotated in the direction opposite to the predetermined direction (the direction of arrow F). As a result, the first swing gear 133 swings in the direction of the arrow P3 around the drive gear 132, and as a result, reaches the position shown in the figure. At this time, the first swing gear 133 is disengaged away from the idler gear 135, and the drive transmission between the first swing gear 133 and the first gear train 138a is cut off. And the gear which meshes with the 1st rocking gear 133 will be in the state of only the drive gear 132 which is an input gear. In such a state, the first swing gear 133 is rotated by the drive gear 132 and is in a state of only idling on the spot.

  At the same time, the second swing gear 134 swings in the direction of the arrow P4 around the drive gear 132, meshes with (in contact with) the idler gear 137 of the third gear train 138c, and moves to the third gear train 138c. Transmit drive. At this time, the second swing gear 134 is disengaged away from the idler gear 136, and the drive transmission between the second swing gear 134 and the second gear train 138b is cut off.

  As described above, the gear train is switched at the same time as the plurality of gear trains are selectively switched according to the forward / reverse motion of the motor 131 by the swing motion of the two swing gears, that is, according to the rotation direction of the drive gear 132. The drive connection to and release from can be performed.

  In the present embodiment, the drive gear 132 rotates in a predetermined direction and the second swing gear before the drive is transmitted (drive coupled) between the first swing gear 133 and the first gear train 138a. The drive transmission between 134 and the third gear train 138c is cut (released). Further, before the drive gear 132 rotates in the direction opposite to the predetermined direction and the drive is transmitted between the second swing gear 134 and the third gear train 138c, the first swing gear 133 and the first gear train are transmitted. The drive transmission with 138a is cut off. That is, the first gear train 138a and the third gear train 138c are prevented from being driven simultaneously.

  Furthermore, when the drive gear 132 rotates in a predetermined direction, the timing at which the drive is transmitted between the first swing gear 133 and the first gear train 138a, and the second swing gear 134 and the second gear train 138b. The timing at which the drive is transmitted to is the same. For this reason, in this embodiment, as described above, the relationship between the first swing gear 133 and the second swing gear 134 is restricted.

  That is, the first swing gear 133 and the second swing gear 134 have the same swing distance. Further, the first oscillating gear 133 and the second oscillating gear 134 have the same rotation radius that oscillates around the rotation center of the drive gear 132. Therefore, (module) × (number of teeth) of the gear member 139 of the first swing gear 133 is the same as (module) × (number of teeth) of the gear member 139 of the second swing gear 134. . In this embodiment, since the gear member 139 is shared, the module and the number of teeth are the same.

  Thus, the first rocking gear 133 and the second rocking gear 134 are rotated by the drive gear 132 that is the same input gear, and the rotation radius and the rocking distance are the same. Therefore, the first oscillating gear 133 and the second oscillating gear 134 perform substantially the same operation and can perform drive switching at almost the same timing. As a result, when the motor 131 is rotated forward, the timing at which the load shaft of the first gear train 138a begins to rotate and the timing at which the load shaft of the second gear train 138b begins to rotate can be made substantially the same. On the other hand, when the motor 131 is rotated in the reverse direction, the drive connection of the second gear train 138b is released at approximately the same timing as the connection of the first gear train 138a is released, and the drive connection to the third gear train 138c is made. Will come to be.

  In order to match the timing of drive connection and release as described above, at least the swing distance between the first swing gear 133 and the second swing gear 134 is the same. Thereby, the timing of drive connection and release can be made closer. Further, by making the rotation radii of the first oscillating gear 133 and the second oscillating gear 134 the same, this timing can be made closer, and the (module) × (the number of teeth) of the gear should be made the same. Thus, this timing can be made almost the same.

  When the drive switching device 130 configured as described above is connected to the fixing device 100, the first gear train 138a meshes with (couples to) the gear 142 that transmits driving to the opposing roller 102. Further, the second gear train 138 b meshes with a gear 144 that transmits driving to the discharge roller 401. Further, the third gear train 138 c meshes with the gear 143 that transmits the drive to the pressure release mechanism 103. Therefore, the gear 142 that is the conveyance drive unit and the gear 143 that is the pressure release drive unit are transmitted from different swing gears among the plurality of swing gears. That is, drive is transmitted to the gear 142 from the first swing gear 133 via the first gear train 138a. In addition, driving is transmitted to the gear 143 from the second swing gear 134 via the third gear train 138c.

  In the case of the present embodiment, the gear 144 that is the discharge drive unit is configured so that the other swinging gear among the plurality of swinging gears transmits the drive to the gear 142 that is the transport driving unit. Drive is transmitted from the moving gear. That is, when the drive is transmitted from the first swing gear 133 to the gear 142, the drive is transmitted to the gear 144 from the second swing gear 134 that is another swing gear.

  Therefore, when the motor 131 is rotated forward, the first swing gear 133 is connected to the first gear train 138a, and the driving force of the motor 131 is transmitted to the gear 142 connected to the first gear train 138a. . As a result, the opposing roller 102 to which the drive is transmitted from the gear 142 rotates, and the recording material is conveyed at the nip portion N. At this time, the second swing gear 134 is connected to the second gear train 138b, and the driving force of the motor 131 is also transmitted to the gear 144 connected to the second gear train 138b. As a result, the discharge roller 401 to which driving is transmitted from the gear 144 rotates, and the recording material that has passed through the nip portion N is discharged.

  Here, since the drive switching device 130 has substantially the same drive connection timing as described above, the opposing roller 102 and the discharge roller 401 rotate at substantially the same timing. At this time, since the driving connection of the second rocking gear 134 with the third gear train 138c is released, no driving force is transmitted to the gear 143 connected with the third gear train 138c, and the pressurization is performed. The release mechanism 103 is not driven.

  On the other hand, when the motor 131 is rotated in the reverse direction, the drive connection between the first swing gear 133 and the first gear train 138a is released, and the rotation of the opposing roller 102 is stopped. At the same time, the drive connection between the second swing gear 134 and the second gear train 138b is released, and the second swing gear 134 is connected to the third gear train 138c. Thereby, the rotation of the discharge roller 401 is stopped, and the driving force of the motor 131 is transmitted to the gear 143 connected to the third gear train 138c. As a result, the cam 103a of the pressure release mechanism 103 to which the drive is transmitted from the gear 143 rotates to perform the pressure release operation.

  In the case of this embodiment configured as described above, a plurality of swing gears, the first swing gear 133 and the second swing gear 134, are swung around the rotation center of the drive gear 132. Therefore, it is possible to switch from one motor 131 to the first gear train 138a, the second gear train 138b, and the third gear train 138c, which are many drive paths. That is, in this embodiment, it is possible to switch to three gear trains. Further, since it is not necessary to provide the one-way clutch as described above for switching the driving path, it can be configured with a small space. That is, when a one-way clutch is used, two gears of an output gear and an input gear are required for each drive path. On the other hand, in this embodiment, since the swing gear is used to switch the drive path, the number of gears can be reduced, the space occupied by the drive switching device 130 can be reduced, and the number of parts can be reduced. Cost reduction can be achieved.

  Here, when trying to operate by switching more drive paths, the drive switching error can be reduced and the drive switching can be performed at an appropriate timing so that each drive does not start to move apart. Is required. On the other hand, in the present embodiment, by configuring as described above, it is possible to switch to the drive path where the timing is to be the same, and to perform the drive switching operation at an appropriate timing.

  That is, in the present embodiment, since the first gear train 138a and the third gear train 138c are not driven at the same time, the opposing roller 102 and the pressure release mechanism 103 respectively connected thereto are driven simultaneously. Never happen. Further, when the second swing gear 134 is connected to the third gear train 138c, the drive connection with the second gear train 138b is released. Accordingly, the pressure release operation of the fixing device 100 can be performed after the drive transmission to the opposing roller 102 and the discharge roller 401 is released. Similarly, after the drive transmission to the pressure release mechanism 103 is released, the opposing roller 102 and the discharge roller 401 can be rotated.

  Further, since the drive connection and release timings are substantially the same, the rotation of the opposing roller 102 and the discharge roller 401 can be started simultaneously, and for example, the recording material can be prevented from being jammed between them. That is, in the case of this embodiment, it is possible to switch to many drive paths, and to switch to a drive path that you do not want to drive at the same time and to switch to a drive path that you want to drive at the same time. It is possible to reduce the switching timing error.

<Second Embodiment>
A second embodiment of the present invention will be described with reference to FIG. In the present embodiment, as a drive path for driving transmission from the first swing gear 133, in addition to the first gear line 138a, a fourth gear line 138d as a fourth drive path is provided. Since other configurations and operations are the same as those in the first embodiment described above, the following description will focus on portions that are different from the first embodiment.

  In the present embodiment, when the motor 131 (see FIGS. 6 and 7) rotates forward, as shown in FIG. 12A, the first swing gear 133 swings in the direction of the arrow P1. The motor 131 is connected to the idler gear 135 to transmit the drive of the motor 131 to the first gear train 138a. On the other hand, when the motor 131 rotates in the reverse direction, as shown in FIG. 12 (b), the first swing gear 133 swings in the direction of the arrow P3 to be connected to the idler gear 160, and the fourth gear. The drive of the motor 131 is transmitted to the row 138d. As with the first embodiment, the second swing gear 134 transmits driving to the second gear train 138b and the third gear train 138c in accordance with the forward / reverse rotation of the motor 131, respectively.

  In the case of this embodiment, when the motor 131 rotates forward and backward as described above, there are two gear trains that are switched by each swing gear, so that a total of four loads to be rotated can be provided. Can be provided. That is, it is possible to switch from one motor 131 to four drive paths.

<Third Embodiment>
A third embodiment of the present invention will be described with reference to FIG. In the case of the present embodiment, there are three swing gears that swing around the drive gear 132. In other words, in addition to the first swing gear 133 and the second swing gear 134, a third swing gear 161 as a third swing rotating body is provided. The third rocking gear 161 also includes a fifth gear train 138e as a fifth drive path and a sixth gear train 138f as a sixth drive path in accordance with forward and reverse rotation of the motor 131 (see FIGS. 6 and 7). And drive to each. Thus, the drive path | route which can be switched can be increased further by increasing a rocking | fluctuation gear. Other configurations and operations are the same as those in the second embodiment described above.

<Other embodiments>
The present invention is not limited to the configuration of each of the embodiments described above, and the number of swing gears can be further increased as long as the load that is simultaneously rotated is within the range that can be simultaneously driven by the installed drive source. And the drive path | route which can be switched can be increased further.

  In addition, as an example of a gear that performs a swinging operation, a swinging gear including a gear member, a holder member, and an elastic member has been described. However, in the present invention, the configuration is not limited to this, and the swinging gear may be configured in other configurations. Any device that performs dynamic motion may be used.

  The drive gear as the drive rotator and the oscillating gear as the oscillating rotator may have other configurations as long as they can contact and transmit rotation. For example, a friction wheel that transmits rotation by friction may be used. In this case, the drive path is also constituted by a friction wheel. However, with regard to the drive path, the member that contacts the gear or friction wheel as the oscillating rotating body is constituted by the gear or friction wheel, but the other parts are other power transmission members such as pulleys and belts. You may comprise by these.

  In addition to the fixing device as described above, the object to be switched by the drive / separation switching device of the present invention can be applied to other configurations such as a device for conveying a recording material. Furthermore, the present invention can be applied to other configurations that perform drive switching other than the image forming apparatus.

  DESCRIPTION OF SYMBOLS 10 ... Image forming apparatus / 100 ... Fixing apparatus (heating apparatus) / 101 ... Fixing film (rotating body) / 102 ... Opposite roller (nip forming member) / 103 ... Pressure release mechanism / 130 ... Drive switching device / 131 ... Motor (drive source) / 132 ... Drive gear (drive rotator) / 133 ... First swing gear (first swing rotator) / 134 ... Second oscillating gear (second oscillating rotating body) / 138a ... First gear train (first drive path) / 138b ... Second gear train (second drive path) / 138c Third gear train (third drive path) / 142... Gear (conveyance drive unit) / 143... Gear (pressure release drive unit) / 144... Gear (discharge drive unit) / 400.・ Discharge part (discharge means)

Claims (8)

A first rotating body;
A second rotating body that forms a nip portion for fixing a toner image on the recording material while conveying the recording material in cooperation with the first rotating body;
The nip portion capable of fixing a toner image to the first rotating body and the second rotating body by pressurizing at least one of the first rotating body and the second rotating body toward the other. A pressure member capable of taking a first position to be formed and a second position at which the nip portion is released with respect to the first position;
A moving mechanism that moves the pressure member from the first position to the second position;
A transport rotating body for transporting a recording material transported from the nip portion;
Drive gear,
A drive source capable of rotationally driving the drive gear in a first direction and a second direction opposite to the first direction;
A swing gear that swings by rotation of the drive gear, and a first swing position that transmits the rotational driving force of the drive gear to the rotation of the first rotating body by meshing with the first gear; Oscillating so as to be able to assume a second oscillating position where the rotational driving force of the driving gear is not transmitted to the rotation of the first rotating body by disengagement from the first gear. Oscillating gear
A swing gear that swings by rotation of the drive gear, and a third swing position that transmits the rotational driving force of the drive gear to the rotation of the transport rotating body by meshing with the second gear; A second swinging gear that swings so as to be able to take a fourth swinging position that meshes with the gear 3 and transmits the rotational driving force of the drive gear to the moving mechanism,
In conjunction with the rotation of the driving gear in the first direction, the first rocking gear rotates the driving force of the driving gear at the first rocking position. The second oscillating gear transmits the rotational driving force of the driving gear to the rotation of the conveying rotator at the third oscillating position.
In conjunction with the rotation of the drive gear in the second direction, the first rocking gear is positioned at the second rocking position, while the second rocking gear is the fourth rocking gear. Transmitting the rotational driving force of the drive gear to the moving mechanism at the swing position;
A fixing device. In conjunction with the rotation of the drive gear in the second direction, the rotation of the first rotating body and the transport rotating body stops.
The fixing device according to claim 1. The second oscillating gear is disengaged from the third gear when positioned at the third oscillating position, and the second gear when positioned at the fourth oscillating position. Is disengaged,
The fixing device according to claim 1, wherein If rotation of the drive gear is switched to the first direction from the second direction, before the first swing gear you positioned in the first pivoted position, the second swing Transmission of the rotational driving force of the driving gear to the moving mechanism by the gear is released ,
The fixing device according to any one of 請 Motomeko 1 to 3 you wherein a. The first swing gear and the second swing gear have the same swing distance, respectively.
The fixing device according to any one of 請 Motomeko 1 to 4 you wherein a. The first oscillating gear and the second oscillating gear have the same rotation radius that oscillates around the rotation center of the drive gear .
The fixing device according to 請 Motomeko 5 you wherein a. The first swing gear and the second swing gear are gears having the same (module) × (number of teeth),
The fixing device according to any one of 請 Motomeko 1 to 6 you, characterized in that. The second rotating body is a cylindrical film and is rotated by the first rotating body.
The fixing device according to claim 1, wherein

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