JP6596839B2 - RECORDING MEDIUM CONVEYING DEVICE, FIXING DEVICE, IMAGE FORMING DEVICE, AND RECORDING MEDIUM CONVEYING DEVICE ADJUSTING METHOD - Google Patents

Description

  The present invention relates to a recording medium conveyance device, a fixing device, an image forming apparatus, and a method for adjusting a recording medium conveyance device.

  The image forming apparatus disclosed in Patent Document 1 includes a transport unit that includes a first roll and can be attached to and detached from the housing on the apparatus main body side. The casing on the apparatus main body side is provided with a second roll that is rotationally driven by a drive unit provided on the apparatus main body side. The first roll is paired with the second roll when the transport unit is mounted on the housing, and rotates following the rotation of the second roll.

JP2013-241255A

  In a recording medium conveyance device in which a roll drive unit is provided on the apparatus main body side, when adjusting the roll torque during conveyance of the recording medium, the torque adjustment is not performed by the drive unit (inside the apparatus main body) on the apparatus main body side. It is difficult to adjust the torque.

  The present invention relates to a recording medium conveying apparatus, a fixing apparatus, an image forming apparatus, and a recording apparatus that can easily perform a torque adjustment operation as compared with a configuration that adjusts the torque of a roll when conveying a recording medium inside the apparatus main body. It is an object to obtain a method for adjusting a medium transport device.

A recording medium conveying apparatus according to a first aspect of the present invention includes a first roll provided in the apparatus main body and capable of rotating about its own axis, and a recording medium sandwiched together with the first roll provided rotatably in a casing. The apparatus main body, comprising: a second roll; a driving unit that is provided in the casing and rotationally drives the second roll; and a pressing unit that is provided in the casing and presses the second roll against the first roll. An assembly that can be attached to and detached from the assembly.

To the driving means of the recording medium conveying apparatus according to the second aspect of the present invention, the torque limiter for limiting the torque transmitted to the second roll are provided.

The torque limiter of the recording medium conveyance device according to the third aspect of the present invention is provided with a torque adjustment unit that can adjust the torque transmitted to the second roll.

The pressing means of the recording medium transporting apparatus according to the fourth aspect of the present invention is provided with a pressing force adjusting section that can adjust the pressing force of the second roll with respect to the first roll.

Fixing device according to a fifth aspect of the present invention includes a recording medium conveying device according to the first aspect one of the fourth aspect, a heating means for heating the second roll, the recording medium The upper developer is fixed on the recording medium.

An image forming apparatus according to a sixth aspect of the present invention includes the fixing device according to the fifth aspect and a forming unit that is provided on the upstream side of the fixing device in the conveyance direction of the recording medium and forms a developer image on the recording medium. And having.

According to a seventh aspect of the present invention, there is provided a method for adjusting a recording medium conveyance device, comprising: a first roll provided in the apparatus main body and capable of rotating about its own axis; and a rotation provided in a casing and recording together with the first roll. A second roll that sandwiches the medium; a drive unit that is provided on the housing and rotationally drives the second roll; a torque limiter that is provided on the drive unit and that limits torque transmitted to the second roll; and the torque A torque adjusting portion provided in the limiter for adjusting the torque transmitted to the second roll; a pressing means provided in the housing for pressing the second roll against the first roll; and the pressing means provided in the pressing means. And a pressing force adjusting unit that can adjust a pressing force of the second roll with respect to the first roll, and an assembly that is attachable to and detachable from the apparatus main body. Adjustment method Attaching the assembly removed from the apparatus main body to a jig having a rotatable adjustment roll imitating the first roll, and pressing the second roll against the first roll of the jig. In the state, the step of adjusting the pressing force by the pressing force adjusting unit, and while the second roll is pressed against the first roll of the jig while rotating the second roll by the driving means, Adjusting the torque by the torque adjusting unit.

According to the first aspect of the invention, the torque adjustment operation can be easily performed as compared with the configuration in which the torque of the roll during the conveyance of the recording medium is adjusted inside the apparatus main body.

According to the second aspect of the invention, the torque adjustment operation can be easily performed as compared with the configuration having no torque limiter.

According to the third aspect of the invention, the torque adjustment operation can be easily performed as compared with the configuration in which the torque adjustment unit is not provided.

According to the fourth aspect of the invention, the adjustment operation of the pressing force of the second roll relative to the first roll can be easily performed as compared with the configuration having no pressing force adjusting unit.

Invention of the fifth aspect, as compared with the structure having no recording medium conveying device according to the first aspect in any one of the fourth aspect, to prevent the recording medium is stretched by heating.

The invention of the sixth aspect can suppress image defects caused by the expansion of the recording medium, compared to the configuration that does not have the fixing device described in the fifth aspect .

According to the seventh aspect of the invention, the torque adjustment operation can be easily performed as compared with the method of adjusting the torque of the roll during conveyance of the recording medium inside the apparatus main body.

1 is a schematic diagram illustrating an overall configuration of an image forming apparatus according to a first embodiment. FIG. 3 is a perspective view of a fixing unit according to the first embodiment. FIG. 3 is a perspective view of a fixing unit according to the first embodiment. FIG. 3 is a perspective view illustrating a state where a fixing unit is removed from the fixing unit according to the first embodiment. FIG. 3 is a perspective view of a support frame of the fixing unit according to the first embodiment. FIG. 3 is a perspective view illustrating a state where a support frame is removed from the fixing unit according to the first embodiment. It is explanatory drawing which shows the state which adjusts a torque with the fixing unit and jig | tool which concern on 1st Embodiment. FIG. 6 is a perspective view of a paper transport device according to a second embodiment. It is a perspective view which shows the state which removed the conveyance unit in the paper conveying apparatus which concerns on 2nd Embodiment. It is a perspective view of the conveyance unit which concerns on 2nd Embodiment. It is the perspective view which looked at the conveyance unit concerning a 2nd embodiment from the 1st conveyance roll side. It is explanatory drawing which shows the state which adjusts a torque with the conveyance unit and jig | tool which concern on 2nd Embodiment.

[First embodiment]
Hereinafter, an example of the adjustment method of the recording medium conveyance device, the fixing device, the image forming apparatus, and the recording medium conveyance device according to the first embodiment will be described with reference to the drawings. First, the overall configuration of the image forming apparatus will be described, and then the configuration and operation of an example of a fixing device and a recording medium conveyance device, which are the main parts of the present embodiment, will be described.

  In the following description, the direction indicated by the arrow Y in FIG. 1 is the apparatus height direction, and the direction indicated by the arrow Z in FIG. 1 is the apparatus width direction. Further, a direction (indicated by X) orthogonal to the device height direction and the device width direction is defined as the device depth direction. When the image forming apparatus 10 is viewed from the side where a user (not shown) stands (when viewed from the front), the apparatus depth direction, the apparatus height direction, and the apparatus width direction are described as an X direction, a Y direction, and a Z direction.

  Further, when it is necessary to distinguish one side and the other side in each of the X direction, the Y direction, and the Z direction, the image forming apparatus 10 is viewed from the front, the upper side is + Y side, the lower side is -Y side, and the back side. Is described as + X side, the front side as -X side, the right side as + Z side, and the left side as -Z side.

〔overall structure〕
As shown in FIG. 1, an image forming apparatus 10 according to the present embodiment includes four image forming units 12Y, 12M, 12C, and 12K as an example of a forming unit, a transport roll 14, a preheating unit 20, and a transport roll. 28 and a fixing unit 50 as an example of a fixing device. The transport roll 14 and the transport roll 28 constitute a part of a transport device (not shown) that transports a sheet P as an example of a recording medium, and the main body (not shown) of the image forming apparatus 10 with the X direction as an axial direction. ) Is rotatably provided. Further, a main body unit 30 as an example of an apparatus main body is provided in a part of the main body of the image forming apparatus 10. Note that the subscript “Y” indicates yellow, “M” indicates magenta, “C” indicates cyan, and “K” indicates black (black).

  The transport device (not shown) is configured to transport the paper P in a direction indicated by an arrow A (transport direction) at a predetermined transport speed (for example, 60 [m / min]). The paper P is a continuous paper. Further, as an example, the paper P is transported from the −Y side to the + Y side on the upstream side of the transport roll 14 in the transport direction, and obliquely below (+ Z side and −Y side) from the transport roll 14 to the transport roll 28. To the -Y side downstream of the transport roll 28

  In the conveyance direction of the paper P, the four image forming units 12Y, 12M, 12C, and 12K are arranged on the upstream side of the conveyance roll 14. Further, in the transport direction of the paper P, the preheating unit 20 is disposed downstream of the transport roll 14 and upstream of the transport roll 28. Further, the fixing unit 50 is disposed on the downstream side of the transport roll 28. The operation of each unit of the image forming apparatus 10 is controlled by the control unit 18.

<Image forming unit>
The image forming units 12Y, 12M, 12C, and 12K shown in FIG. 1 perform charging, exposure, development, transfer, and cleaning, respectively, and an example of a developer image on the paper P using toner T as an example of the developer. As a result, a toner image TA is formed. The image forming units 12Y, 12M, 12C, and 12K have the same configuration except for the toner T to be used. For this reason, when it is not necessary to distinguish the toner colors in the following description, the four are collectively referred to as the image forming unit 12. As an example, the toner T includes a wax (not shown) and is made of powder containing a polyester resin (binder resin) as a main component.

<Preheating part>
As an example, the preheating unit 20 illustrated in FIG. 1 includes six carbon heaters 22, a cover 24 that covers the six carbon heaters 22, and a reflection plate 26. The six carbon heaters 22 are arranged so as not to contact the paper P. For example, the white background portion of the paper P is output at 90 ° C. and the toner image TA is output at 110 ° C. And the heating temperature is set. In the following description, the surface of the paper P on which the toner image TA is formed is referred to as an image surface PA, and the surface opposite to the image surface PA side is referred to as a non-image surface PB.

[Main part configuration]
Next, the main unit 30 and the fixing unit 50 will be described.

<Main unit>
As shown in FIG. 4, the main unit 30 includes, as an example, a set of first fixing frames 42 and 43, a set of first slide frames 44 and 45, four linear sliders 46, and two air cylinders. 47. The illustration of the + X side air cylinder 47 is omitted. In addition, the main body unit 30 includes, as an example, a pair of second fixing frames 32 and 33, a pair of second slide frames 34 and 35, four linear sliders 36, and two air cylinders 37. ing.

  The first fixing frames 42 and 43 are plate members that extend along the YZ plane and face each other in the X direction. The first fixing frame 42 is disposed on the −X side. In the first fixing frame 42, three cutout portions 42A opened to the + Z side are formed at three positions with a gap in the Y direction. The first fixing frame 43 is disposed on the + X side. In the first fixing frame 43, three notches opened on the + Z side are formed at three positions spaced in the Y direction. Since the three cutout portions of the first fixing frame 43 are formed in the same manner as the cutout portion 42A, the illustration is omitted.

  The height positions in the Y direction of the three notches 42A and the height positions in the Y direction of the three notches (not shown) of the first fixing frame 43 are aligned. A side plate 41A is attached to the side surface on the + Z side of the first fixing frame 42 so as to close the notch portion 42A. A bracket that supports one end of a halogen heater 64 described later is attached to the side plate 41A. A side plate 41B is attached to the side surface on the + Z side of the first fixing frame 43 so as to close a notch (not shown).

  A bracket that supports the other end portion of the halogen heater 64 to be described later is attached to the side plate 41B. The first fixing frame 42 and the first fixing frame 43 are fastened with screws (not shown) to both ends in the X direction of three coupling members 48 that are arranged with the X direction as a longitudinal direction and spaced in the Y direction. Are connected.

  The first slide frame 44 is a plate material that extends along the YZ plane, and is disposed on the −X side of the first fixing frame 42. The first slide frame 44 and the first fixing frame 42 are connected by being fastened to both ends of the two link members 39 with screws (not shown). Further, a movable portion (not shown) of the air cylinder 47 on the −X side is attached to the side surface on the −Z side of the first slide frame 44.

  The first slide frame 45 is a plate material that extends along the YZ plane, and is disposed on the + X side with respect to the first fixing frame 43. The first slide frame 45 and the first fixing frame 43 are connected by being fastened to both ends of the two link members 39 with screws (not shown). The illustration of the link member 39 on the -Y side is omitted. A movable portion (not shown) of the + X side air cylinder 47 is attached to the side surface of the first slide frame 45 on the −Z side.

  The linear slider 46 has a rail portion extending in the Z direction and a moving portion that moves in the Z direction along the rail portion. In addition, the code | symbol of a rail part and a moving part is abbreviate | omitted. The linear slider 46 has two moving parts attached to the side surface on the −X side of the first slide frame 44 with a space in the Y direction, and to the side surface on the + X side of the first slide frame 45 in the Y direction. Two moving parts are attached at intervals. Furthermore, the linear slider 46 has each rail portion attached to a frame constituting a part of a housing (not shown) of the image forming apparatus 10 (see FIG. 1).

  A movable portion (not shown) of the air cylinder 47 is retracted to the −Z side when not operating, and moves to the + Z side by air pressure when operating. Thus, the first slide frames 44 and 45 and the first fixing frames 42 and 43 are retracted to the −Z side when not operating, and move to the + Z side when operating.

  The second fixing frames 32 and 33 are plate members that extend along the YZ plane and face each other in the X direction. The second fixing frame 32 is disposed on the −X side. In the second fixing frame 32, three notches 32A that are open on the + Z side are formed at three positions with a gap in the Y direction. The second fixing frame 33 is disposed on the + X side. In the second fixing frame 33, three notches 33A opened to the + Z side are formed at three positions spaced in the Y direction.

  The height positions in the Y direction of the three notches 32A and the height positions in the Y direction of the three notches 33A are aligned. The second fixing frame 32 and the second fixing frame 33 are connected by being fastened with screws (not shown) to both ends of two coupling members 38 having the X direction as an axial direction. A screw hole 32B opened to the + Z side is formed on the side surface on the + Z side of the second fixing frame 32 and on the + Y side and the −Y side with respect to the notch 32A. A screw hole 33B opened to the + Z side is formed on the side surface on the + Z side of the second fixing frame 33 and on the + Y side and the −Y side with respect to the notch 33A.

  The second slide frame 34 is a plate material that extends along the YZ plane, and is disposed on the −X side with respect to the second fixing frame 32. The second slide frame 34 and the second fixing frame 32 are connected by being fastened with screws (not shown) to both ends of two link members 39 whose axial direction is the X direction. A movable portion (not shown) of the −X side air cylinder 37 is attached to the side surface of the second slide frame 34 on the + Z side.

  The second slide frame 35 is a plate material that extends along the YZ plane, and is disposed on the + X side with respect to the second fixing frame 33. The second slide frame 35 and the second fixing frame 33 are coupled by being fastened with screws (not shown) to both ends of the two link members 39 having the X direction as an axial direction. A movable portion (not shown) of the + X side air cylinder 37 is attached to the side surface of the second slide frame 35 on the + Z side.

  The linear slider 36 has a rail portion that extends in the Z direction and a moving portion that moves in the Z direction along the rail portion. In addition, the code | symbol of a rail part and a moving part is abbreviate | omitted. The linear slider 36 has two moving parts attached to the side surface on the −X side of the second slide frame 34 with a gap in the Y direction, and to the side surface on the + X side of the second slide frame 35 in the Y direction. Two moving parts are attached at intervals. Further, each rail portion of the linear slider 36 is attached to a frame constituting a part of a housing (not shown) of the image forming apparatus 10 (see FIG. 1).

  The movable portion (not shown) of the air cylinder 37 is retracted to the + Z side when not operating, and moves to the −Z side by air pressure when operating. Thus, the second slide frames 34 and 35 and the second fixing frames 32 and 33 are retracted to the + Z side when not operating, and move to the −Z side when operating.

{Fixing part}
Next, the fixing unit 50 will be described.

  The fixing unit 50 illustrated in FIG. 1 includes a transport unit 60 as an example of a recording medium transport device, and a halogen heater 52 as an example of a heating unit.

<Transport section>
1 includes three fixing units as an example of an assembly including three first fixing rolls 62 as an example of first rolls and second fixing rolls 72 as an example of second rolls. 70.

(First fixing roll)
The first fixing roll 62 has a metal core 62A, and is provided on the side plates 41A and 41B (see FIG. 4) of the main unit 30 via bearings (not shown). It can rotate around its own axis with the direction as the axial direction. The first fixing roll 62 has a multilayer structure including a core metal 62A, an elastic layer 62B, and a release layer (not shown) from the radially inner side to the outer side. As an example, the outer diameter of the first fixing roll 62 is 80 [mm].

  Further, the first fixing roll 62 can be brought into contact with and retracted from the paper P by the operation of the air cylinder 47 described above. The pressing force (load) applied to the second fixing roll at the nip portion where the paper P is sandwiched between the first fixing roll 62 and the second fixing roll 72 described later is a constant load system. As an example, the pressing force is 980. [N]. A halogen heater 64 (see FIG. 1) is provided inside the first fixing roll 62.

  The halogen heater 64 shown in FIG. 1 generates heat when energized from a power source (not shown), and heats the first fixing roll 62 from the inside. For example, the halogen heater 64 is a temperature sensor (not shown) that detects the temperature of the second fixing roll 72 such that the temperature (fixing temperature) of the outer peripheral surface of the second fixing roll 72 is maintained at 120 [° C.]. The feedback control is performed based on the output of (omitted).

<Fusing unit>
As shown in FIG. 2, the three fixing units 70 are arranged such that the first fixing roll 62 and the second fixing roll 72 are opposed to each other in the Z direction, and the second fixing of the main body unit 30 is spaced apart in the Y direction. Attached to the frames 32 and 33.

  As illustrated in FIG. 3, the fixing unit 70 includes a second fixing roll 72, a driving unit 80 as an example of a driving unit, and a pressing unit 90 as an example of a pressing unit. Further, the fixing unit 70 includes a frame 74 on which the second fixing roll 72 is rotatably provided, and a support frame 76 that supports the second fixing roll 72, the frame 74, the driving unit 80, and the pressing unit 90. Yes. The frame 74 and the support frame 76 are examples of a housing.

(Support frame)
As shown in FIG. 5, the support frame 76 includes a first side plate 76A, a second side plate 76C, a third side plate 76D, stop plates 76E and 76F, and support plates 76G and 76H.

  The first side plate 76A is disposed along the XY plane with the X direction as the longitudinal direction. Further, two screw holes 76B penetrating in the Z direction are formed in the + X side end portion and the −X side end portion of the first side plate 76A. Adjustment screws 79A and 79B described later are screwed into the two screw holes 76B. The −Z side end portions of the adjustment screws 79A and 79B protrude to the −Z side from the first side plate 76A. Furthermore, a plurality of brackets 77 are attached to the side surface on the + Z side of the first side plate 76A.

  The second side plate 76C is disposed along the YZ plane, and the + Z side end of the second side plate 76C is fastened with a screw to the −Z side of the −X side end of the first side plate 76A. Yes. The third side plate 76D is disposed along the YZ plane, and the + Z side end of the second side plate 76D is fastened with a screw to the −Z side of the + X side end of the first side plate 76A. . That is, the first side plate 76A, the second side plate 76C, and the third side plate 76D are assembled in a U-shape that opens to the −Z side in plan view (Y direction view).

  A stop plate 76E is attached to the end portion on the −Z side of the second side plate 76C. A stop plate 76F is attached to the end portion on the −Z side of the third side plate 76D. The stop plates 76E and 76F are arranged along the X-Y plane with an interval in the X direction, and are arranged on the + X side and the −X side of the frame 74 (see FIG. 3). That is, the stop plates 76E and 76F suppress the displacement of the frame 74 in the X direction.

  The stop plates 76E and 76F are formed with two through-holes 76I penetrating in the Z direction at intervals in the Y direction. Further, the stop plates 76E and 76F are formed with protruding portions 76J protruding toward the -Z side. The length of the protruding portion 76J in the Y direction is shorter than the length of the opening in the Y direction of the notches 32A and 33A (see FIG. 4), and is not in contact with the second fixing frames 32 and 33.

  The support plate 76G extends with the Z direction as the longitudinal direction, and the + Z side end of the support plate 76G is attached to the −X side end of the first side plate 76B. Further, the support plate 76G is disposed on the + X side and the −Y side with respect to the second side plate 76C. Further, a support pin 78A is attached to an end portion on the −Z side of the support plate 76G. The support pin 78A is a cylindrical pin whose axial direction is the X direction, and protrudes toward the −X side with respect to the support plate 76G.

  The support plate 76H extends in the Z direction as a longitudinal direction, and the + Z side end of the support plate 76H is attached to the + X side end of the first side plate 76B. The support plate 76H is disposed on the −X side and the −Y side with respect to the third side plate 76D. Further, a support pin 78B is attached to the −Z side end of the support plate 76H. The support pin 78B is a cylindrical pin whose axial direction is the X direction, and protrudes toward the + X side with respect to the support plate 76H. The shaft of the support pin 78A and the shaft of the support pin 78B are disposed substantially coaxially along the X direction.

(flame)
As shown in FIG. 6, the frame 74 includes a first side plate 74A, a second side plate 74B, a third side plate 74C, and a mounting plate 74D.

  The first side plate 74A is arranged along the XY plane with the X direction as the longitudinal direction. A second side plate 74B and a third side plate 74C are attached to the + X side end portion and the −X side end portion of the first side plate 74A and the −Z side side surface. Further, a mounting plate 74D is attached to the side surface on the −X side and the + Z side with respect to the X-direction central portion of the first side plate 74A. The mounting plate 74D extends from the first side plate 74A to the + Z side. Further, a through hole 74H that penetrates in the X direction is formed in the mounting plate 74D.

  A bracket 75A for supporting wiring (not shown) is attached to the + X side of the first side plate 74A on the + X side of the attachment plate 74D. A bracket 75B is attached to the side surface on the + Z side of the first side plate 74A and the attachment plate 74D. Both ends of a shaft 75C whose axial direction is the X direction are rotatably provided on the bracket 75B and the mounting plate 74D. Furthermore, columnar pressed members 74G that protrude from the first side plate 74A to the + Z side are provided at both ends in the X direction of the first side plate 74A.

  The second side plate 74B and the third side plate 74C extend from the first side plate 74A to the −Z side and face each other in the X direction. In addition, a through-hole 74E penetrating in the X direction is formed at the center in the Y direction of the second side plate 74B and the third side plate 74C. Furthermore, a notch 74F opened to the -Y side is formed at the end (lower end) on the -Y side of the second side plate 74B and the third side plate 74C. The notch 74F has a circular hole on the + Y side and a linear groove on the −Y side when viewed in the X direction. In addition, about the notch 74F of the 3rd side board 74C, since it is formed similarly to the notch 74F of the 2nd side board 74B, illustration is abbreviate | omitted.

  Here, the support pins 78A and 78B (see FIG. 5) of the support frame 76 are inserted into circular holes in the notch 74F of the frame 74. Thus, the frame 74 can swing (relatively move) with respect to the support frame 76 with the support pins 78A and 78B as the swing center.

  Bearings (not shown) are fitted in the two through holes 74E of the second side plate 74B and the third side plate 74C, respectively. The two bearings rotatably support both axial end portions of the second fixing roll 72.

(Second fixing roll)
As shown in FIG. 6, the second fixing roll 72 is supported by the second side plate 74B and the third side plate 74C of the frame 74, and on the + Z side of the paper P (see FIG. 1) It can rotate around its axis. Further, the second fixing roll 72 includes a cored bar 72A, an elastic layer 72B (see FIG. 1) and a release layer (not shown) coated on the outer periphery of the cored bar 72A from the radially inner side to the outer side. It has a multilayer structure.

  Further, the second fixing roll 72 can be brought into contact with and retracted from the paper P by the operation of the air cylinder 37 (see FIG. 2) described above. A halogen heater 52 is provided inside the second fixing roll 72. The first fixing roll 62 and the second fixing roll 72 have the same configuration. A cleaning blade 73 is in contact with a portion of the outer peripheral surface of the second fixing roll 72 opposite to the first fixing roll 62 side. The cleaning blade 73 removes wax and the like attached to the outer peripheral surface of the second fixing roll 72.

(Halogen heater)
The halogen heater 52 shown in FIG. 1 generates heat when energized from a power source (not shown), and heats the second fixing roll 72 from the inside. Further, as an example, the halogen heater 52 is a temperature sensor (not shown) that detects the temperature of the second fixing roll 72 so that the temperature (fixing temperature) of the outer peripheral surface of the second fixing roll 72 is maintained at 120 ° C. The feedback control is performed based on the output of (omitted). As a result, the second fixing roll 72 comes into contact with the image surface PA of the paper P and fixes the toner image TA on the paper P.

<Driver>
As shown in FIG. 6, the drive unit 80 is provided on the frame 74. The drive unit 80 includes a motor 82, a gear train 84 that transmits the rotation of the motor 82 to the second fixing roll 72, and a torque limiter 86 to which a first gear 84 </ b> A (described later) of the gear train 84 is attached. ing.

  The motor 82 includes a motor main body 82A attached to the side surface on the + X side of the attachment plate 74D, a shaft 82B that protrudes to the −X side from the attachment plate 74D through the through hole 74H, and is driven to rotate by the motor main body 82A. have. A part of the wiring (not shown) of the motor main body 82A is supported by a bracket 75, and the end of the wiring is connected to the control unit 18 (see FIG. 1). A connector portion (not shown) is provided in the middle of the wiring, and the connector portion can be divided into a wiring on the fixing unit 70 side and a wiring on the control unit 18 side.

  The gear train 84 includes a first gear 84A that is rotatably provided on the shaft 82B, a second gear 84B and a third gear 84C that are rotatably provided on the shaft 75C, and a core metal 72A of the second fixing roll 72. And a fourth gear 84D attached to the end portion on the −X side. The tooth portion of the first gear 84A meshes with the tooth portion of the second gear 84B. The tooth portion of the third gear 84C meshes with the tooth portion of the fourth gear 84D.

  The torque limiter 86 is provided on the shaft 82B and integrated with the first gear 84A. The torque limiter body 86A is provided on the torque limiter body 86A, and the adjustment screw 86B is provided on the torque limiter body 86A to adjust (set) the torque to be limited (see FIG. 7). Reference). The adjustment screw 86B is an example of a torque adjustment unit. In the present embodiment, a permahis torque controller PHT-10D manufactured by Ogura Clutch Co., Ltd. is used as an example of the torque limiter 86.

  Here, when a torque lower than the torque set in the second fixing roll 72 is generated, the torque limiter 86 transmits the driving force from the shaft 82B to the first gear 84A. That is, in the drive unit 80, when the generated torque is lower than the set torque, the rotational force of the first gear 84A is centered via the second gear 84B, the shaft 75C, the third gear 84C, and the fourth gear 84D. The second fixing roll 72 is rotated and transmitted to the gold 72A. The torque limiter 86 limits the torque during rotation of the second fixing roll 72 to less than the set value when a torque greater than the value set in the second fixing roll 72 is generated.

<Pressing part>
As shown in FIG. 3, the pressing portion 90 is provided at the + X side end and the −X side end of the support frame 76. The pressing portion 90 on the + X side is provided with the adjustment screw 79B, the pressing member 92, and the compression coil spring 94 described above. The -X side pressing portion 90 is provided with the adjusting screw 79A, the pressing member 92, and the compression coil spring 94 described above. The adjustment screws 79A and 79B are an example of a pressing force adjustment unit.

  The adjustment screws 79A and 79B are moved in the clockwise direction when viewed in the Z direction from the + Z side, and moved to the −Z side when rotated in the counterclockwise direction, and moved to the + Z side when rotated in the counterclockwise direction. . The pressing member 92 is a columnar member whose axial direction is the Z direction, and is rotatably connected to the −Z side tip portions of the adjusting screws 79A and 79B. That is, when the adjustment screws 79A and 79B are rotated, the pressing member 92 is not rotated. The compression coil spring 94 is sandwiched between the pressing member 92 and the pressed member 74G with the Z direction as the deformation direction.

  Here, in the pressing portion 90, when the adjusting screws 79A and 79B are turned and the pressing member 92 moves to the -Z side, the compression coil spring 94 is compressed, and the pressing force as a reaction force against the compression force is applied to the pressed member 74G. It comes to work. Then, when a pressing force is applied to the pressed member 74G, the pressing unit 90 moves the second fixing roll 72 together with the frame 74 to the −Z side so that the outer peripheral surface of the second fixing roll 72 is moved to the first fixing roll 62 ( (See FIG. 1).

  In the pressing portion 90, when the adjusting screws 79A and 79B are turned and the pressing member 92 moves to the + Z side, the frame 74 is pulled by the compression coil spring 94, and the second fixing roll 72 moves to the + Z side. ing. Thus, in the pressing unit 90, the pressing force of the second fixing roll 72 to the first fixing roll 62 can be adjusted by the rotation of the adjusting screws 79A and 79B.

  As shown in FIG. 2, the fixing unit 70 inserts a screw (not shown) into the above-described through hole 76I and fastens the screw to the screw holes 32B and 33B (see FIG. 4), whereby the second fixing. Attached to the frames 32 and 33. Further, the fixing unit 70 is removed (detached) from the second fixing frames 32 and 33 by removing the screws.

<Jig>
Next, the jig 100 for adjusting the torque of the second fixing roll 72 will be described.

  FIG. 7 shows a state in which the fixing unit 70 removed from the image forming apparatus 10 (see FIG. 1) is placed on the jig 100 in a plan view (viewed in the Y direction). As an example, the jig 100 includes a pedestal 102, an adjustment roll 103, a coupling member 104, and a torque sensor 106.

  The pedestal 102 includes a plate-shaped pedestal main body 102A extending in the XZ plane, a rectangular parallelepiped mounting base 102B formed on the + Y side and the + Z side of the pedestal main body 102A, and the + Y side and the −Z side of the pedestal main body 102A. The supporting walls 102C, 102D, and 102E are formed. A fixing member (not shown) for fixing the support frame 76 of the fixing unit 70 is provided on the surface on the + Y side of the mounting table 102B.

  The support wall 102C and the support wall 102D are opposed to each other with an interval in the X direction and are upright along the Y direction. Further, through holes (not shown) penetrating in the X direction are formed in the support wall 102C and the support wall 102D, and bearings 108 are fitted into the through holes, respectively. The two bearings 108 are inserted with axial end portions of a core metal 103A of an adjusting roll 103, which will be described later.

  The support wall 102E stands upright along the Y direction on the + X side of the support wall 102D. A torque sensor 106 is attached to the support wall 102E. The torque sensor 106 has a shaft 107. The shaft 107 is disposed so as to be coaxial with the core metal 62 </ b> A of the first fixing roll 62, and is connected to the core metal 62 </ b> A by the coupling member 104. As a result, when the adjustment roll 103 rotates following the rotation of the second fixing roll 72, the shaft 107 rotates and the torque is measured by the torque sensor 106.

  The adjustment roll 103 is similar to the first fixing roll 62 (see FIG. 1) (having the same configuration as the first fixing roll 62). It has a multilayer structure having a layer and a release layer (reference numeral omitted). The outer diameter of the adjustment roll 103 is 80 [mm] as an example. The adjustment roll 103 is rotatably supported by the bearing 108, the support wall 102C, and the support wall 102D. Further, the outer peripheral surface of the adjustment roll 103 is disposed so as to contact the outer peripheral surface of the second fixing roll 72 when the support frame 76 of the fixing unit 70 is fixed to the mounting table 102B.

(Torque calculation)
In the image forming apparatus 10 shown in FIG. 1, as an example, the limit torque of the torque limiter 86 (see FIG. 6) is 0.8 [N · m], and the rated torque of the motor 82 (see FIG. 6) is 1.8 [N • m]. Further, when the nip portion is formed by the first fixing roll 62 and the second fixing roll 72, the load torque at the time of rotation is 0.2 [N · m], and acts on the second fixing roll 72 by the contact of the cleaning blade 73. It is assumed that the load torque is 0.4 [N · m].

  Here, as an example, when the paper P is conveyed at 60 [m / min], 0.8− (0.2 + 0.4) = 0.2 [N · m] acts on the paper P as tension. Will do. That is, if the radius of the second fixing roll 72 is 40 [mm], 0.2 / 0.04 = 5 [N] is the tension acting on the paper P by the first fixing roll 62 and the second fixing roll 72. Become.

  In the image forming apparatus 10, the paper P is prevented from slipping at the transfer portion. In the image forming apparatus 10, even if the second fixing roll 72 rotates at a linear speed 5% faster than the conveyance speed of the paper P, the paper P becomes the rotational resistance of the second fixing roll 72. For this reason, since slip occurs between the shaft 82B and the first gear 84A, the fixing unit 50 transports the paper P at 60 [m / min]. As described above, since the tension of 5 [N] acts on the paper P, the paper P is prevented from being slackened.

[Action]
Next, the operation of the first embodiment will be described.

<Adjustment of pressing force and torque>
In the image forming apparatus 10 shown in FIG. 1, as an example, when the paper P to be used is replaced, a torque setting table created in advance based on the type of the paper P and the set temperatures in the preheating unit 20 and the fixing unit 50, A torque to be set in the fixing unit 70 is determined. Further, the pressing force to be set in the fixing unit 70 is determined based on the pressing force setting table prepared in advance based on the type of the paper P and the set temperatures in the preheating unit 20 and the fixing unit 50. The pressing force and torque are determined by the adjuster. In the following description, torque to be set in the fixing unit 70 (torque acting on the first fixing roll 62) is referred to as set torque.

  In the fixing unit 50 shown in FIG. 2, when the set torque needs to be changed, the fastening between the second fixing frames 32 and 33 and the fixing unit 70 is released, and the three fixing units 70 are removed from the main body unit 30 ( Will be withdrawn). Since the three fixing units 70 have the same configuration, the adjustment of the torque of one fixing unit 70 will be described, and the description of the remaining two fixing units 70 will be omitted.

  As shown in FIG. 7, the fixing unit 70 is attached (fixed) to the mounting base 102 </ b> B of the jig 100 using a fixing member (not shown). In the fixing unit 70, two load cells 93 are attached instead of the two pressing members 92 (see FIG. 3). The load cell 93 is a converter that converts the magnitude of the force into an electric signal. The force converted by the load cell 93 is displayed as a pressing force F [N] at the nip portion where the adjustment roll 103 and the second fixing roll 72 are in contact with each other by a measuring instrument (not shown). .

  Subsequently, in a state where the second fixing roll 72 is pressed against the adjustment roll 103 of the jig 100, the adjustment screws 79A and 79B are turned while looking at the pressing force F of a measuring instrument (not shown). The pressing force F is adjusted to be 980 [N]. That is, the pressing force of the nip portion between the first fixing roll 62 (see FIG. 1) and the second fixing roll 72 when the fixing unit 70 is attached to the main unit 30 (see FIG. 2) is the same value. The pressing force F is adjusted.

  Subsequently, in a state where the second fixing roll 72 is pressed against the adjustment roll 103, the motor 82 is operated using a power source and a controller (not shown), so that the motor 82 rotates the second fixing roll 72. At this time, the controller controls the motor so that the linear velocity of the outer periphery of the second fixing roll 72 is the same as the conveyance speed (for example, 60 [m / min]) of the paper P of the image forming apparatus 10 (see FIG. 1). The operation of 82 is controlled. Then, the adjustment roll 103 rotates following the rotation of the second fixing roll 72.

  Torque acting on the adjustment roll 103 is measured by the torque sensor 106. Here, when the torque measured by the torque sensor 106 is different from the set torque, the rotation of the second fixing roll 72 by the motor 82 is stopped, the torque is adjusted by turning the adjusting screw 86B, and then the second is driven by the motor 82. The fixing roll 72 is rotated to measure the torque. By repeating this process, the torque of the torque limiter 86 (the limit torque and the allowable torque) is adjusted, and the set torque of the fixing unit 70 is adjusted. As an example, the set torque is 0.2 [N · m].

  Subsequently, after the load cell 93 is replaced with the pressing member 92 (see FIG. 3), the fixing unit 70 is removed from the jig 100. As shown in FIG. 2, the fixing unit 70 is fastened (attached) to the second fixing frames 32 and 33 of the main body unit 30 with screws (not shown). In this manner, adjustment of the pressing force at the nip portion between the first fixing roll 62 and the second fixing roll 72 and adjustment of the set torque are performed. The adjustment of the pressing force and the adjustment of the set torque may be performed after heating so that the temperature of the first fixing roll 62 and the second fixing roll 72 becomes the fixing temperature (for example, 120 [° C.]). .

<Operation of Image Forming Apparatus>
In the image forming apparatus 10 shown in FIG. 1, after adjusting the pressing force and the set torque, the first fixing roll 62 and the second fixing roll 72 are retracted to the −Z side and the + Z side with respect to the paper P. When the image forming apparatus 10 forms an image on the paper P, as shown in FIG. 2, the air cylinders 47 and 37 are operated so that the first fixing frames 42 and 43 and the second fixing frames 32 and 33 are on the + Z side, − Move to the Z side. As a result, the second fixing roll 72 is pressed toward the first fixing roll 72, and the paper P is sandwiched with the first fixing roll 62 to form a nip portion.

  Subsequently, the second fixing roll 72 is rotationally driven by the operation of the motor 82 (see FIG. 6), and the first fixing roll 62 is driven to rotate. In the preheating unit 20, as an example, the carbon heater 22 generates heat so that the toner image TA becomes 110 [° C.]. The first fixing roll 62 and the second fixing roll 72 are heated to 120 [° C.] as an example. The toner image TA formed by the image forming unit 12 is heated by the preheating unit 20 and then heated and pressed by the fixing unit 50, thereby being fixed on the paper P.

  Here, in the transport unit 60, as described above, the driving unit 80 (see FIG. 6) and the pressing unit 90 (see FIG. 3) that determine the torque that applies tension to the paper P are provided in the fixing unit 70. Yes. Therefore, in the transport unit 60, the torque of the second fixing roll 72 can be adjusted by removing the fixing unit 70 from the main unit 30 (see FIG. 2).

  Further, the transport unit 60 adjusts the torque of the second fixing roll 72 outside the main body unit 30 to adjust the torque when transporting the paper P while the fixing unit 70 is mounted on the main body unit 30. Compared with the structure and method to perform, the adjustment operation of a torque can be performed easily. Since torque measurement and torque adjustment are performed with high accuracy, the torque acting on the paper P is managed, and the expansion of the paper P during conveyance is suppressed.

  In the transport unit 60, a torque limiter 86 is provided in the drive unit 80. For this reason, the torque can be adjusted by the torque limiter 86 without changing the entire drive unit 80 when adjusting the torque, so that the torque adjustment operation can be easily performed. Further, in the transport unit 60, when an excessive transport force acts on the paper P when transporting the paper P with low rigidity, the torque limiter 86 reduces the torque when the second fixing roll 72 rotates to a value less than the set value. Restrict. Accordingly, it is possible to suppress an excessive conveying force from acting on the paper P as compared with the configuration in which the torque limiter 86 is not provided. The stiffness is the “stiffness” of the paper P measured by JIS P 8143.

  In addition, in the transport unit 60, as shown in FIG. 7, the adjustment screw 86B is provided in the torque limiter 86. Therefore, when adjusting the torque, it is not necessary to replace the torque limiter 86 and perform torque adjustment. For this reason, torque adjustment work can be easily performed. Further, in the transport unit 60, the torque is finely adjusted by the rotation of the adjustment screw 86B. Thereby, compared with the structure in which the adjustment screw 86B is not provided in the torque limiter 86, the torque adjustment accuracy is improved.

  Further, in the transport unit 60, the adjustment screws 79 </ b> A and 79 </ b> B are provided in the pressing unit 90, so that the second fixing roll with respect to the first fixing roll 62 can be replaced without replacing the pressing unit 90 when adjusting the pressing force. The pressing force 72 can be adjusted. For this reason, it is possible to easily adjust the pressing force.

  In the fixing unit 50, since the paper P is prevented from being stretched during transport in the transport unit 60, even when the paper P is heated by the halogen heater 52, the paper P is stretched by heating as compared with the configuration without the transport unit 60. It is suppressed.

  In the image forming apparatus 10, since the sheet P is prevented from extending in the fixing unit 50, an image defect (for example, an image shift or the like) caused by the sheet P extending compared to a configuration that does not include the fixing unit 50. ) Is suppressed.

[Second Embodiment]
Next, an example of a method for adjusting the recording medium conveyance device, the image forming apparatus, and the recording medium conveyance device according to the second embodiment will be described. Note that the same reference numerals as those in the first embodiment are given to the same members and parts as those in the first embodiment described above, and the description thereof is omitted.

  FIG. 8 shows a sheet conveying apparatus 120 as an example of a recording medium conveying apparatus according to the second embodiment. The sheet conveying apparatus 120 includes a pair of support frames 122 and 123 as an example of the apparatus main body, a first conveying roll 124 as an example of a first roll, and a conveying unit 130 as an example of an assembly. .

(Support frame)
As shown in FIG. 9, the support frames 122 and 123 are plate members that extend along the YZ plane, and face each other in the X direction. The support frame 122 is disposed on the −X side, and the support frame 123 is disposed on the + X side. Further, the support frame 122 and the support frame 123 are formed with three notches 126 opened on the + Z side at intervals in the Y direction. The notch 126 has a size and shape into which the above-described protrusion 76J (see FIG. 5) fits.

  Further, the support frame 122 and the support frame 123 are formed with screw holes 122A that are open to the + Z side on the + Y side side with respect to the respective notches 126 and to the −Z side side surface. In addition, the support frame 122 and the support frame 123 are formed with three through holes 128 penetrating in the X direction on the −Z side of the notch 126. Each through-hole 128 is fitted with a bearing 132 whose axial direction is the X direction. Three sets of bearings 132 that face each other in the X direction respectively support both ends in the X direction of a shaft portion 124A, which will be described later, of the first transport roll 124.

(First transport roll)
As shown in FIG. 9, the first transport roll 124 is supported by the bearing 132 so as to be rotatable about its own axis with the X direction as the axial direction. The first transport roll 124 includes a cylindrical shaft portion 124A having the X direction as an axial direction, and three outer circumferential surfaces of the shaft portion 124A spaced apart in the X direction and projecting radially outward. And a column-shaped roll portion 124B. The three roll portions 124B have substantially the same outer diameter when viewed in the X direction.

<Transport unit>
As shown in FIGS. 10 and 11, the transport unit 130 includes a second transport roll 134 as an example of a second roll, a drive unit 80 that rotationally drives the second transport roll 134, and the second transport roll 134. And a pressing portion 90 that is pressed against one transport roll 124 (see FIG. 8). Further, the transport unit 130 includes a frame 74 on which the second transport roll 134 is rotatably provided, and a support frame 76 that supports the second transport roll 134, the frame 74, the driving unit 80, and the pressing unit 90. Yes.

(Second transport roll)
The second transport roll 134 is supported by the second side plate 74B and the third side plate 74C of the frame 74, and is rotatable on the + Z side of the paper P (see FIG. 8) about its own axis with the X direction as the axial direction. ing. In addition, the second transport roll 134 is formed with a cylindrical shaft portion 134A having the X direction as an axial direction and three outer circumferential surfaces of the shaft portion 134A spaced apart in the X direction and projecting radially outward. And a column-shaped roll portion 134B. The three roll portions 134B have substantially the same outer diameter when viewed in the X direction. A fourth gear 84 </ b> D is attached to the −X side end portion of the shaft portion 134 </ b> A of the second transport roll 134.

  As shown in FIG. 8, the transport unit 130 inserts a screw (not shown) into the through hole 76I (see FIG. 10) and fastens the screw into the screw hole 122A (see FIG. 9), thereby supporting the support frame 122. , 123 (attached). The transport unit 130 is detached from the support frames 122 and 123 by removing the screws.

<Jig>
FIG. 12 shows a jig 140 for adjusting the torque of the second transport roll 134. The jig 140 includes a jig 100 (see FIG. 7) according to the first embodiment in which an adjustment roll 136 is rotatably provided instead of the adjustment roll 103 (see FIG. 7). It is the same. Further, the shaft 107 is connected to the + X side end portion of a shaft portion 136 </ b> A (described later) of the adjustment roll 136 by the coupling member 104.

  The adjustment roll 136 is an imitation of the first transport roll 124 (see FIG. 8) (having the same configuration as the first transport roll 124). Specifically, a cylindrical shaft portion 136A having the X direction as an axial direction, and a cylindrical roll portion that is formed on the outer peripheral surface of the shaft portion 136A at intervals in the X direction and protrudes radially outward. 136B. The adjustment roll 136 is rotatably supported by the bearing 108, the support wall 102C, and the support wall 102D. Further, the outer peripheral surface of the adjustment roll 136 is disposed so as to come into contact with the outer peripheral surface of the second transport roll 134 when the support frame 76 of the transport unit 130 is fixed to the mounting table 102B.

[Action]
Next, the operation of the second embodiment will be described.

<Adjustment of pressing force and torque>
In the paper transport device 120 shown in FIG. 8, as an example, when the paper P to be used is replaced, the torque (set torque) to be set in the transport unit 130 is determined based on the torque setting table created based on the type of the paper P in advance. It is determined. Further, the pressing force to be set in the transport unit 130 is determined based on the pressing force setting table created based on the type of the paper P in advance. The pressing force and torque are determined by the adjuster.

  Subsequently, in order to adjust the pressing force and torque, the fastening between the support frames 122 and 123 and the transport unit 130 is released, and the three transport units 130 are removed (detached) from the support frames 122 and 123. Since the three transport units 130 have the same configuration, the adjustment of the torque of one transport unit 130 will be described, and the description of the remaining two transport units 130 will be omitted.

  As shown in FIG. 12, the transport unit 130 is attached (fixed) to the mounting table 102B of the jig 140 using a fixing member (not shown). In the transport unit 130, two load cells 93 are attached instead of the two pressing members 92 (see FIG. 10). The force converted by the load cell 93 is displayed as a pressing force F [N] at the nip portion where the adjustment roll 136 and the second transport roll 134 are in contact with each other by a measuring instrument (not shown).

  Subsequently, in a state where the second transport roll 134 is pressed against the adjustment roll 136 of the jig 140, the adjustment screws 79A and 79B are turned while watching the pressing force F of the measuring instrument (not shown) to adjust the pressing force F. . That is, the pressing force at the nip portion between the first transport roll 124 (see FIG. 10) and the second transport roll 134 when the transport unit 130 is attached to the support frames 122 and 123 (see FIG. 8) is the same value. Thus, the pressing force F is adjusted.

  Subsequently, in a state where the second transport roll 134 is pressed against the adjustment roll 136, the motor 82 is operated using a power source and a controller (not shown), thereby rotating the second transport roll 134. At this time, the operation of the motor 82 is controlled by the controller so that the linear velocity of the outer periphery of the second transport roll 134 is the same as the transport speed of the paper P of the paper transport device 120 (see FIG. 8). Then, the adjustment roll 136 is rotated following the rotation of the second transport roll 134.

  Torque acting on the adjustment roll 136 is measured by the torque sensor 106. Here, when the torque measured by the torque sensor 106 is different from the set torque, as described above, after the rotation of the second transport roll 124 is stopped and the torque is adjusted by turning the adjustment screw 86B, the motor 82 is adjusted. Thus, the second transport roll 124 is rotated to measure the torque. By repeating this process, the set torque of the transport unit 130 is adjusted.

  Subsequently, after the load cell 93 is replaced with the pressing member 92 (see FIG. 10), the transport unit 130 is removed from the jig 140. As shown in FIG. 8, the transport unit 130 is fastened (attached) to the support frames 122 and 123 with screws (not shown). In this way, adjustment of the pressing force of the nip portion between the first conveyance roll 124 and the second conveyance roll 134 and adjustment of the set torque are performed.

  In the paper conveyance device 120 illustrated in FIG. 8, the driving unit 80 and the pressing unit 90 are provided in the conveyance unit 130. For this reason, in the paper transport device 120, the torque of the second transport roll 134 can be adjusted even when the transport unit 130 is removed from the support frames 122 and 123.

  Further, in the paper transport device 120, the torque of the second transport roll 134 is adjusted outside the support frames 122 and 123. Thereby, compared with the structure and method which adjust a torque in the state in which the conveyance unit 130 was mounted | worn with the support frames 122 and 123, the adjustment operation of a torque can be performed easily. Since torque measurement and torque adjustment are performed with high accuracy, the torque acting on the paper P is managed, and the expansion of the paper P during conveyance is suppressed.

  In addition, this invention is not limited to said embodiment.

  The image forming unit 12 of the image forming apparatus 10 may include only the image forming unit 12K. The image forming apparatus 10 may be provided with a heating plate that contacts the non-image surface PB of the paper P or a heating roll that contacts the non-image surface PB of the paper P, instead of the preliminary heating unit 20. The number of carbon heaters 22 in the preheating unit 20 is not limited to six, and may be other numbers. Further, the toner T used in the image forming apparatus 10 is not limited to the polyester resin, but may be another resin.

  The image forming apparatus 10 is not only a dry electrophotographic image forming apparatus, but also a wet electrophotographic image forming apparatus using a liquid developer containing oil (carrier liquid) and an ink jet type image forming apparatus. Also good. Further, the configuration of the image forming apparatus 10 can be applied to a printing machine or a coating machine using a printing plate. The recording medium is not limited to paper, and a film such as a polypropylene film may be used.

  In addition, the configuration of the image forming apparatus 10 is not limited to the continuous paper P, but can be applied to a sheet-fed printer. When applied to a sheet-fed machine, a paper guide plate is provided so as to sandwich the paper in order to determine the paper transport path. In addition, a one-way clutch is attached to the second gear 84B so that the driving force is transmitted when the motor 82 rotates in the direction for conveying the paper, and the driving force is interrupted when the motor 82 rotates in the reverse direction. This improves the removability when a paper jam occurs.

  The fixing unit 50 is not limited to using three sets of the first fixing roll 62 and the second fixing roll 72, but uses one set, two sets, or four or more sets of the first fixing roll 62 and the second fixing roll 72. It may be a thing. In the fixing unit 70, a fixing belt may be used instead of the second fixing roll 72.

  The drive unit 80 may not include the torque limiter 86. In this case, the set torque may be adjusted by replacing the motor 82. Further, the torque limiter 86 may not have the adjustment screw 86B. In this case, the set torque may be adjusted by replacing the torque limiter 86. The pressing part 90 may not have the adjusting screws 79A and 79B. In this case, the compression coil spring 94 may be replaced to adjust the pressing force at the nip portion.

  The attachment of the fixing unit 70 to the main body unit 30 and the attachment of the transport unit 130 to the support frames 122 and 123 are not limited to screws. For example, a lock mechanism that rotates the lever so that the fixing unit 70 and the conveyance unit 130 are not detached, or a lock mechanism that pushes and locks the fixing unit 70 and the conveyance unit 130 and then pushes and separates again may be used. . The mounting direction of the fixing unit 70 with respect to the main unit 30 is not limited to the Z direction, and may be the X direction or the Y direction.

10 Image forming apparatus 12C Image forming unit (example of forming unit)
12K image forming unit (example of forming unit)
12M image forming unit (example of forming unit)
12Y image forming unit (example of forming unit)
30 Main unit (example of device main unit)
50 fixing unit (an example of a fixing device)
52 Halogen heater (an example of heating means)
60 Conveying section (an example of a recording medium conveying apparatus)
62 First fixing roll (an example of a first roll)
70 fixing unit (an example of an assembly)
72 Second fixing roll (an example of a second roll)
74 frames (example of housing)
76 Support frame (example of housing)
79A Adjustment screw (example of pressing force adjustment part)
79B Adjustment screw (Example of pressing force adjustment unit)
80 Drive unit (an example of drive means)
86 Torque limiter 86B Adjustment screw (Example of torque adjustment unit)
90 pressing part (an example of pressing means)
100 Jig 103 Adjustment Roll 120 Paper Conveying Device (Example of Recording Medium Conveying Device)
122 Support frame (an example of an apparatus main body)
123 Support frame (an example of the device body)
124 1st conveyance roll (an example of the 1st roll)
130 Transport unit (an example of an assembly)
134 Second transport roll (an example of a second roll)
140 Jig

Claims (7)

A first roll provided in the apparatus main body and rotatable about its own axis;
A second roll rotatably provided in the casing and sandwiching the recording medium together with the first roll; drive means provided in the casing for rotating the second roll; and the second roll provided in the casing A pressing means that presses the first roll against the first roll, and an assembly that can be attached to and detached from the apparatus main body,
A recording medium conveying apparatus having   The recording medium conveying apparatus according to claim 1, wherein the driving unit is provided with a torque limiter that limits a torque transmitted to the second roll.   The recording medium conveyance device according to claim 2, wherein the torque limiter is provided with a torque adjustment unit that can adjust a torque transmitted to the second roll.   The recording medium conveyance according to any one of claims 1 to 3, wherein the pressing unit is provided with a pressing force adjusting unit that can adjust a pressing force of the second roll with respect to the first roll. apparatus. The recording medium carrying device according to any one of claims 1 to 4,
Heating means for heating the second roll;
A fixing device for fixing the developer on the recording medium to the recording medium. A fixing device according to claim 5;
A forming unit provided upstream of the fixing device in the conveyance direction of the recording medium and forming a developer image on the recording medium;
An image forming apparatus. A method for adjusting a recording medium carrying device according to claim 4 quoting claim 3.
Attaching the assembly removed from the apparatus main body to a jig having a rotatable adjustment roll imitating the first roll;
In pressed against the second roll in said adjustment roll of the jig, the step of adjusting the pressing force by the pressing force adjustment portion,
Adjusting the torque by the torque adjuster while rotating the second roll by the driving means while pressing the second roll against the adjustment roll of the jig;
A method for adjusting a recording medium conveyance device having