JP2018155847A - Image formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the configuration in comparison to a case where functions of warpage suppression of a transfer belt and reference surface formation at the replacement of the transfer belt are realized by completely different mechanisms.SOLUTION: An oscillator 58 takes the posture fallen to the front side when a transfer belt unit 24 takes the belt operation posture. At this time, a warpage suppression part 72 constituted as a portion of the oscillator 58 protrudes upward from a depth side end of a transfer belt 38, and an abutting part 74 constituted as a member to which the oscillation motion of the oscillator 58 is transmitted takes the retreat state. The oscillator 58 takes the posture raised to the depth side (side apart from the transfer belt 38) when the transfer belt unit 24 takes the belt replacement posture. At this time, the warpage suppression part 72 takes the retreat state, and the abutting part 74 is lifted up to form a reference surface to which the depth side end of the transfer belt 38 after replacement abuts.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an image forming apparatus.

  As an electrophotographic image forming apparatus, an image forming apparatus including a transfer belt unit is widely used. Such an image forming apparatus primarily transfers a toner image formed on a photoreceptor to a transfer belt (intermediate transfer belt), and secondarily transfers the primary transferred toner image to a medium.

  Patent Document 1 discloses an image forming apparatus in which a transfer belt unit can be pulled out of a housing for maintenance. Patent Document 2 discloses a plurality of abutting portions against which a rear end portion of a transfer belt to be newly mounted in the transfer belt replacement operation is abutted. Each abutting portion is in a standing posture with the transfer belt tension being weakened, and is in a lying position with the transfer belt tension being strengthened.

JP 2012-123233 A JP 2010-217528 A

  The end of the transfer belt may be warped due to aging. When the degree of warping is large, proper transfer belt travel cannot be expected. In view of this, a member (a warpage suppressing portion) that suppresses warpage is provided on the upper side of the end portion of the transfer belt in a state of being close to and opposed to the end portion. When the end portion of the transfer belt warps upward, the warp suppressing portion suppresses the warping of the end portion.

  On the other hand, when the surface of the transfer belt deteriorates with age, image formation defects occur. Therefore, when the transfer belt reaches a predetermined life, it is replaced with a new one. During the replacement work, the transfer belt unit is generally pulled out of the housing. The replacement work is performed in the pulled-out state. In this replacement operation, an abutting portion with which the rear end of the transfer belt is abutted is used to set a newly mounted transfer belt at a correct position.

  When the warp suppressing part and the abutting part as described above are provided, the warp suppressing part is automatically installed at a predetermined position above the end of the transfer belt in a normal state, and the warp suppressing part is provided at the time of belt replacement. Is required to be automatically retracted from the vicinity of the transfer belt so as not to disturb the belt replacement work (first need). At the same time, when the belt is replaced, the abutting portion constituting the reference surface is automatically installed at a predetermined position. In the normal time, the abutting portion is automatically retracted from the vicinity of the transfer belt, and the transfer belt It is required to be configured so as not to disturb the running of the vehicle (second need). If two types of mechanisms are provided completely separately in order to satisfy these two needs, the device configuration becomes complicated.

  An object of the present invention is to realize a configuration that satisfies the two needs of warpage suppression and reference plane formation so that the configuration is simplified as compared with the case where the functions are realized by completely separate mechanisms. There is.

  The invention according to claim 1 includes a transfer belt unit that takes a belt operation posture and a belt replacement posture, and the transfer belt unit includes a transfer belt that rotates and an interlocking mechanism that is provided on the back side of the transfer belt unit. The interlocking mechanism is in a tilted forward position when the transfer belt unit takes the belt operating posture, and rises to the back side when the transfer belt unit takes the belt replacement posture. A swinging body that is in a posture, and is configured as a part of the swinging body, and protrudes above the back end of the transfer belt in the collapsed posture to suppress warping of the back end, and in a retracted state in the rising posture And a member that transmits a swinging motion of a part of the swinging body or the swinging body, and is in the rising posture. The back end portion is abutted against the reference surface of the transfer belt after the replacement form Te, including a contact portion to be retracted state in the fall-down posture, it is characterized in.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the abutting portion includes an abutting plate to which the oscillating motion of the oscillating body is transmitted, the oscillating body and the abutting plate. Is configured as a separate member.

  According to a third aspect of the present invention, in the image forming apparatus according to the second aspect, the oscillating body includes a main body and a plurality of arms branched from an upper portion of the main body, and the plurality of arms are the warps. A first arm having a portion that functions as a restraining portion, and a second arm having a working end portion that directly or indirectly transmits the rising motion of the rocking body to the butting plate. It is characterized by.

  According to a fourth aspect of the present invention, in the image forming apparatus according to the third aspect, the abutting plate is lifted when the working end portion of the second arm moves upward, whereby one surface of the abutting plate. Functions as the reference surface, and the abutting plate sinks when the working end of the second arm moves downward, whereby the abutting plate enters the retracted state. It is.

  According to a fifth aspect of the present invention, in the image forming apparatus according to the first aspect, the abutting portion is configured as a part of the oscillating body, and the main body of the oscillating body, the warp suppressing portion, and the abutting portion are integrated. It is characterized by that.

  According to a sixth aspect of the present invention, in the image forming apparatus according to the fifth aspect, the image forming apparatus includes a plurality of arms branched from an upper portion of the main body, and the plurality of arms includes a portion that functions as the warp suppressing portion. And a second arm provided with a portion functioning as the abutting portion.

  According to a seventh aspect of the present invention, in the image forming apparatus according to the first aspect, the belt operating posture is a non-inclined posture, and the belt replacement posture is a rotational motion around a rotational shaft located on the back side of the transfer belt unit. It is characterized in that it is an inclined posture generated by.

  According to an eighth aspect of the present invention, in the image forming apparatus according to the first aspect, a plurality of interlocking mechanisms are provided on the back side of the transfer belt unit in the transport direction of the transfer belt, and the plurality of interlocking mechanisms are provided. It operates in synchronism.

  According to the first aspect of the present invention, when realizing a configuration for suppressing warpage and forming a reference surface, the configuration is simplified as compared with a case where these functions are realized by completely separate mechanisms.

  According to the invention which concerns on Claim 2, the freedom degree of the movement of a butting board can be raised.

  According to the invention which concerns on Claim 3, it becomes easy to determine separately the position and attitude | position of a curvature suppression part and an action | operation end part with respect to a main body.

  According to the fourth aspect of the present invention, the reference surface forming state and the retracted state are selectively formed by a simple movement of the abutting plate, ie, a vertical movement.

  According to the invention which concerns on Claim 5, it becomes unnecessary to provide an abutting part as another member.

  According to the invention which concerns on Claim 6, it becomes easy to determine separately the position and attitude | position of a curvature suppression part and an abutting part with respect to a main body.

  According to the invention which concerns on Claim 7, the attitude | position of a rocking | fluctuation body can be changed using the rotational motion at the time of a transfer belt unit changing from a non-inclination attitude | position to an inclination attitude | position.

  According to the eighth aspect of the invention, the warp of the transfer belt can be effectively suppressed, and the parallel state of the transfer belt after replacement can be easily formed.

1 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention. FIG. 6 is a diagram for explaining a state of the transfer belt unit when the transfer belt is replaced in the embodiment of the present invention. FIG. 4 is a perspective view showing a belt operating posture of a transfer belt unit in an embodiment of the present invention. It is a perspective view showing a belt exchange posture of a transfer belt unit in an embodiment of the present invention. It is a perspective view which shows the state of the interlocking mechanism in the belt operation attitude | position of embodiment of this invention. It is a side view which shows the state of the interlocking mechanism in the belt operation attitude | position of embodiment of this invention. It is a side view which shows the state of the interlocking mechanism in the belt exchange attitude | position of embodiment of this invention. It is a side view which shows the state of the said interlocking mechanism in the belt operation attitude | position in the interlocking mechanism of another embodiment of this invention. It is a side view which shows the state of the said interlocking mechanism in the belt replacement | exchange attitude | position in the interlocking mechanism of another embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of an image forming apparatus 10 of the present embodiment. In FIG. 1, the left-right direction of the image forming apparatus 10 is described as the X direction, the depth direction (front-rear direction) is described as the Y direction, and the height direction is described as the Z direction. The same applies to the other drawings.

  The image forming apparatus 10 includes two paper cassette units 12 that accommodate media, a conveyance path 14 that conveys the medium, and an image formation unit 16 that forms a toner image on the medium conveyed by the conveyance path 14. It consists of As shown in FIG. 1, the paper cassette unit 12, the conveyance path 14, and the image forming unit 16 are arranged in this order from the bottom.

  Each of the two paper cassette units 12 accommodates a medium according to the size and type of the medium, for example. The uppermost medium among the plurality of media accommodated in the paper cassette unit 12 is sent out to the transport path by the delivery roller 18. One end of the conveyance path 14 is connected to each sheet cassette unit 12, and the other end (the right side in FIG. 1) is connected to a conveyance path of a fixing device (not shown) through the image forming unit 16. Thus, the medium sent out from the paper cassette unit 12 to the conveyance path is conveyed toward the image forming unit 16 and then conveyed toward the fixing device.

  The image forming unit 16 includes an exposure unit 20, an image forming unit 22, and a transfer belt unit 24. Among these, the exposure unit 20 and the image forming unit 22 are provided for each color of yellow (Y), magenta (M), cyan (C), and black (K).

  The exposure unit 20 forms an electrostatic latent image on the photoconductor 26 by irradiating the surface of the photoconductor 26 described later with exposure light corresponding to each color. The image forming unit 22 includes a photoreceptor 26 that is driven to rotate. As an example, a corona discharge type (non-contact charging type) charger 28 that charges the photosensitive member 26 and the exposure light charged by the charger 28 and irradiated from the exposure unit 20 are provided around the photosensitive member 26. A developing device 30 for developing the electrostatic latent image formed on the toner 26 with toner of each color and a cleaning blade 32 for cleaning the surface of the photoreceptor after transfer are provided. The developing device 30 includes a developer containing member filled with a developer containing toner, and a developing roll that moves the toner filled in the developer containing member to the surface of the photoreceptor 26. . Toner is supplied from a toner cartridge (not shown) to the developer accommodating member.

  The transfer belt unit 24 is provided below each image forming unit 22. The transfer belt unit 24 multiplex-transfers a transfer belt 38 (intermediate transfer belt) in contact with each photoconductor 26 and a toner image formed on each photoconductor 26 inside the transfer belt 38 onto the transfer belt 38. The structure includes four primary transfer rolls 40, a drive roll 42 driven by a motor (not shown), and a support roll 46 disposed so as to face the secondary transfer roll 44 with the transfer belt 38 interposed therebetween.

  The transfer belt 38 is an endless member, and is wound around four primary transfer rolls 40, a drive roll 42, a support roll 46, and a plurality of other rolls. The transfer belt 38 circulates (rotates) as the drive roll 42 rotates. Each primary transfer roll 40 is disposed to face the photoconductor 26 of each image forming unit 22 with the transfer belt 38 interposed therebetween, so that the toner image formed on the photoconductor 26 is transferred to the transfer belt 38. Primary transcription.

  A conveyance path 14 is provided so that the medium passes between the transfer belt 38 and the secondary transfer roll 44, and the medium is fed between the transfer belt 38 and the secondary transfer roll 44. The secondary transfer roll 44 sandwiches the medium with the transfer belt 38 and transfers the toner image onto the medium. In other words, the toner images of the respective colors that have been multiplex-transferred onto the transfer belt 38 are secondarily transferred by the secondary transfer roll 44 onto the medium that has been transported on the transport path 14. Thereby, a toner image is formed on the medium.

  Although omitted in FIG. 1, the image forming apparatus 10 is provided with a fixing device for fixing a toner image formed on a medium. The conveyance path 14 extends to the right side from the image forming unit 16 and is connected to a conveyance path of a fixing device (not shown).

  With this configuration, the medium is sent out from the paper cassette unit 12 to the conveyance path 14, and after a toner image is formed by the image forming unit 16 on the conveyance path 14, the medium is fed into the fixing device. The medium is discharged from the image forming apparatus 10 after the toner image is fixed by the fixing device.

  The image forming apparatus 10 of the present embodiment can pull out the transfer belt unit 24 to the front side (the front side of the apparatus), thereby enabling the transfer belt 38 to be replaced. . In FIG. 1, the position of the transfer belt unit 24 that can be pulled out is indicated by a broken line.

  FIG. 2 is a side view showing a state in which the transfer belt unit 24 is pulled out to the front side (front side, Y direction side in FIG. 2) of the image forming apparatus 10. In FIG. 2, the broken line indicates the position of the transfer belt unit 24 in the posture (belt replacement posture) taken when the transfer belt unit 24 replaces the transfer belt 38. In FIG. 2, each lowercase x, y, z direction indicates an axial direction based on the transfer belt unit 24 in the belt replacement posture, and the same applies to the drawings described below. As shown in FIG. 2, a drawer 50 constituting a slide frame is provided below the transfer belt unit 24, and the transfer belt unit 24 is mounted on the drawer 50. When the drawer 50 is pulled out to the near side of the image forming apparatus 10, the transfer belt unit 24 provided thereon is also pulled out to the near side at the same time. The transfer belt unit 24 that has been drawn out is rotated counterclockwise in FIG. 2 with the back side as a rotation axis (moved upward) in FIG. It is supposed to be. In this belt replacement posture, the transfer belt 38 is replaced.

  FIG. 3 is a diagram illustrating the drawer 50 and the transfer belt unit 24 provided on the drawer 50. The belt operating posture, which is the normal posture of the transfer belt unit 24 (the posture when forming a toner image on a medium), is illustrated. FIG. As shown in FIG. 3, the belt operating posture is a non-tilting posture. As shown in FIG. 3, the transfer belt unit 24 is provided with two interlocking mechanisms 54. The two interlocking mechanisms 54 are provided on the back side (left side in FIG. 3) of the transfer belt unit 24 side by side in the transfer belt conveyance direction. The two interlocking mechanisms 54 operate in synchronization. Only one interlocking mechanism 54 may be provided, or three or more interlocking mechanisms 54 may be provided. The interlocking mechanism 54 is provided with a warp suppressing portion that suppresses warping of the back end portion of the transfer belt 38. Although not shown in the drawing, a warpage suppressing member for suppressing warpage of the front end portion of the transfer belt 38 is provided on the front side of the transfer belt 38.

  A structure 110 is provided on the back side of the transfer belt unit 24. The structure 110 is connected to the lower member 112 fixed to the drawer 50, three intermediate members 114 extending upward (Z direction) from the lower member 112, and connected to the intermediate member 114 of the transfer belt unit 24. And an upper member 116 located on the side. As will be described in detail later, the interlocking mechanism 54 comes into contact with the upper member 116 when the transfer belt unit 24 is in a posture for replacing the transfer belt 38 (belt replacement posture).

  Although not shown, a sensor for detecting the position of the end portion of the transfer belt is provided on the back side of the transfer belt unit 24. When the transfer belt 38 is replaced and a new transfer belt 38 is attached, it is required to attach the transfer belt 38 to an appropriate position where the sensor can read. As will be described later, the image forming apparatus 10 of the present embodiment uses an abutting plate on which the rear end of the new transfer belt 38 is abutted when the transfer belt 38 is replaced. Accordingly, a new transfer belt 38 can be easily attached to an appropriate position where the sensor can read.

  FIG. 4 is a view showing a posture for replacing the transfer belt 38 of the transfer belt unit 24 (belt replacement posture). In FIG. 4, the interlocking mechanism 54 and the roller of the transfer belt unit 24 are omitted. As shown in FIG. 4, when the transfer belt is replaced, the front side (right side in FIG. 4) of the transfer belt unit 24 is lifted up. Then, the tension of the transfer belt is loosened, and the old transfer belt is removed from the front side. Then, a new transfer belt is attached from the front side.

  As shown in FIG. 4, the belt replacement posture is an inclined posture generated by a rotational movement around the rotation axis on the back side (left side in FIG. 4) of the transfer belt unit.

  FIG. 5 is a perspective view showing the interlocking mechanism 54 and its surroundings in the belt operating posture which is a normal posture. The interlocking mechanism 54 includes a base portion 56 and an oscillating body 58. The base portion 56 is a member for fixing the interlocking mechanism 54 to the transfer belt unit 24. The base portion 56 is attached to the outer flat plate member 64 provided in the transfer belt unit 24 with two screws 66 (however, only one screw 66 is depicted in FIG. 5). The rocking body 58 has a main body 59 and a plurality of arms. A main body 59 of the oscillating body 58 is rotatably attached to a rotary shaft mechanism 68 provided in the base portion 56. Thereby, the posture of the oscillating body 58 changes. Specifically, the posture changes from the posture (falling posture) that is tilted toward the transfer belt 38 shown in FIG. 5 to the rising posture during the rising motion from the back side (side away from the transfer belt 38). Thereafter, during the falling-down movement toward the near side, the posture changes from the standing posture to the falling posture. The rocking body 58 is provided with a spring mounting hole 70, and a spring (not shown in FIG. 5) to be described later is attached to the spring mounting hole 70. The plurality of arms branch from the upper part of the main body 59 in a row. The plurality of arms include a first arm 60 having a portion functioning as a warp suppressing portion 72 of the transfer belt 38, and two second end portions having action end portions for transmitting the rising motion of the swinging body 58 to a butting plate described later. Arm 62. Each of the second arms 62 exists on the left and right sides with the first arm 60 interposed therebetween.

  As described above, the main body of the rocking body 58 is configured by branching the plurality of arms (including the warp suppressing portion 72 and the action end portion transmitting to the abutting plate) from the upper portion of the main body 59 of the rocking body 58. With respect to 59, it becomes easy to individually determine the position and posture of the warp suppressing portion 72 and the working end portion.

  On the side of the lower portion of the main body 59 of the rocking body 58, there is an upper member 116 that extends from the drawer. The transfer belt unit 24 is provided with an inner flat plate member 75 along the transfer belt 38. A part of the inner flat plate member 75 is cut out, and an abutting portion 74 used when the transfer belt 38 is replaced is slidable in the vertical direction. The abutting portion 74 includes an abutting plate 76 that forms a reference surface, and a projecting plate 78 that projects outward from the abutting plate 76. The two second arms 62 of the rocking body 58 are in contact with the protruding plate 78 of the abutting portion 74. An intermediate flat plate member 80 is provided between the inner flat plate member 75 and the outer flat plate member 64, and a part of the intermediate flat plate member 80 is located below the protruding plate 78 of the abutting portion 74.

  FIG. 6 is a side view of the interlocking mechanism 54 in the belt operating posture. In the interlocking mechanism 54, a spring 86 is held by a spring mounting hole 70 (not shown in FIG. 6) provided in the rocking body 58 and a spring mounting hole 84 provided in the base portion 56. The spring 86 urges the swinging body 58 to be in a posture (falling posture) in which the swinging body 58 falls to the transfer belt 38 side. A biasing member 88 is provided between the lower portion of the butting plate 76 of the butting portion 74 and the inner flat plate member 75. The urging member 88 urges the abutting portion 74 so as to jump upward.

  As shown in FIG. 6, in a normal posture (belt operating posture) in which a toner image is formed on the medium, the swinging body 58 is in a posture (falling posture) that is tilted toward the transfer belt 38 side. Accordingly, the warp suppressing portion 72 of the first arm 60 is disposed above the rear end portion of the transfer belt 38, and the warp suppressing portion 72 functions to suppress the warp of the transfer belt 38. Further, the second arm 62 presses the protruding plate 78 of the abutting portion 74 downward, so that the abutting portion 74 is retracted below the transfer belt 38. Specifically, the upper end of the abutting plate 76 of the abutting portion 74 is positioned below the transfer belt 38 by α.

  FIG. 7 is a side view of the interlocking mechanism 54 in the belt replacement posture. When the transfer belt unit 24 is tilted in order to replace the transfer belt 38 (S100), the lower part of the main body 59 of the rocking body 58 of the interlocking mechanism 54 contacts the upper member 116 arranged extending from the drawer. Will do. The lower part of the main body 59 of the oscillating body 58 rotates counterclockwise by contacting the upper member 116 (S102), and the upper part of the main body 59 of the oscillating body 58 also rotates counterclockwise (S104). That is, as shown in FIG. 7, the swinging body 58 is in a rising state (a rising posture). In this manner, the posture of the rocking body 58 is changed using the rotational motion when the transfer belt unit 24 changes from the non-tilt posture to the tilt posture. When the swinging body 58 is raised, the warp suppressing portion 72 of the first arm 60 is retracted from the transfer belt 38. Further, the two second arms 62 that have pressed down the protruding plate 78 of the abutting portion 74 are raised, so that the abutting portion 74 jumps upward due to the urging force of the urging member 88 (S106). ). Thereby, a part of the abutting plate 76 of the abutting portion 74 is positioned above the transfer belt 38. As a result, when the new transfer belt 38 is attached, the transfer belt 38 is abutted against the abutment plate 76, so that the transfer belt 38 can be easily attached at an accurate position.

  As described above, the rocking body 58 and the butting plate 76 are configured as separate members, and the rocking motion of the rocking body 58 is transmitted to the butting plate 76. By configuring the rocking body 58 and the butting plate 76 as separate members, the butting plate 76 can freely move independently from the rocking body 58 (the degree of freedom of movement is increased).

  After the transfer belt 38 is replaced, the transfer belt unit 24 is returned to the normal non-inclined state. That is, the transfer belt unit 24 is returned to the belt operating posture. When the transfer belt unit 24 is returned to the normal non-inclined state, the lower portion of the main body 59 of the oscillating body 58 does not come into contact with the upper member 116, and the oscillating body 58 is urged by the urging force of the spring 86 provided in the interlocking mechanism 54. Returns to the posture of falling onto the transfer belt 38 side. Accordingly, the warp suppressing portion 72 is positioned on the upper side of the transfer belt 38, and the abutting portion 74 returns to a state where it is retracted below the transfer belt 38.

  In this way, when the working end of the second arm 62 moves upward, the abutting plate 76 floats, and thereby one surface of the abutting plate 76 functions as a reference surface, and the working end of the second arm 62 When the part moves downward, the abutting plate 76 sinks, and the abutting plate 76 is in a retracted state. A reference surface formation state and a retracted state are selectively formed by a simple movement of the abutting plate 76, ie, a vertical movement.

  In the image forming apparatus 10 of the present embodiment described above, the transfer belt unit 24 includes the interlocking mechanism 54, and the interlocking mechanism 54 includes the swinging body 58. When the transfer belt unit 24 takes the belt operating posture, the swinging body 58 takes the posture of tilting forward, and when the transfer belt unit 24 takes the belt replacement posture, the swinging body 58 takes the posture of rising up. The warp restraining part 72 configured as a part of the rocking body 58 protrudes above the back end of the transfer belt 38 in the tilted position, suppresses warping of the back end, and is in the retracted state in the rising position. In addition, the abutting portion 74 configured as a member to which the swinging motion of the swinging body 58 is transmitted forms a reference surface against which the rear end of the transfer belt 38 after replacement is abutted in the rising posture, and the tilted posture. In evacuation state.

  With this configuration, when realizing a configuration that satisfies the two needs of suppressing the warpage of the transfer belt 38 in the operating state of the transfer belt 38 and forming the reference surface when the transfer belt 38 is replaced, The configuration can be simplified as compared with the case where the functions are realized by completely separate mechanisms.

  More specifically, the above two needs (first need and second need) are as follows. The first need is that the warp suppression unit 72 is automatically installed at a predetermined position above the end of the transfer belt 38 in a normal state, and the warp suppression unit 72 automatically starts from the vicinity of the transfer belt 38 when the belt is replaced. Therefore, it is necessary to configure so as not to disturb the belt replacement work. The second need is that the abutting portion 74 constituting the reference surface is automatically installed at a predetermined position when the belt is replaced, and the abutting portion 74 is automatically retracted from the vicinity of the transfer belt 38 in the normal time. Therefore, it is a need to configure so as not to disturb the running of the transfer belt 38. These first needs and second needs are in a complementary relationship. The image forming apparatus 10 of the present embodiment has a configuration that effectively utilizes the property of the complementary relationship.

  As shown in FIG. 3, a plurality of interlocking mechanisms 54 of this embodiment are provided side by side in the conveyance direction of the transfer belt 38. Thereby, the warp of the transfer belt 38 can be effectively suppressed, and the parallel state of the transfer belt 38 after replacement can be easily formed.

  In the embodiment described above, the working end portion of the second arm 62 of the rocking body 58 causes the rising motion of the rocking body 58 indirectly (via the protruding plate 78 of the butting portion 74). Had been communicated to. However, as long as it can be transmitted to the butting plate 76, it may be transmitted directly. Moreover, as long as it can transmit to the butting plate 76, it may be transmitted via one or more members.

  Next, an interlocking mechanism 90 according to another embodiment will be described. FIG. 8 is a side view showing the belt operating posture of the interlocking mechanism 90 of another embodiment. In FIG. 8, the same members as those in FIG. 6 are denoted by the same reference numerals. Hereinafter, description of the same members as those in FIG. 6 will be omitted. In the interlocking mechanism 90 shown in FIG. 8, the abutting portion 98 is configured as a part of the rocking body 58. That is, the main body 59, the warp suppressing portion 92, and the abutting portion 98 of the rocking body 58 are integrated. Thereby, it is not necessary to provide the abutting part as a separate member.

  As shown in FIG. 8, the rocking body 58 has a main body 59 and a plurality of arms branched from the upper part of the main body 59. The plurality of arms are a first arm 94 including a portion that functions as a warp suppressing portion 92 and a second arm 96 including a portion that functions as an abutting portion 98. The second arm 96 extends from the rotary shaft mechanism 68 side toward the transfer belt 38 side, and extends while changing its angle downward. The abutting portion 98 functions by a portion 100 of the second arm 96 that extends downward. The entire second arm 96 is inclined downward as compared with the first arm 94. Although not shown, two second arms 96 are provided on the left and right (X direction in FIG. 8) with the first arm 94 interposed therebetween. That is, it is the same structure as the 2nd arm 62 in the interlocking mechanism 54 demonstrated using FIGS.

  As described above, the plurality of arms (including the warp suppressing portion 92 and the abutting portion 98) are branched from the upper portion of the main body 59 of the rocking body 58. It becomes easy to individually determine the positions and postures of the warp suppressing portion 92 and the abutting portion 98.

  As shown in FIG. 8, in the belt operating posture, which is a normal posture for forming a toner image on the medium, the swinging body 58 is in a tilted posture, and the warp suppressing portion 92 of the first arm 94 is placed on the transfer belt 38. The abutting portion 98 of the second arm 96 is positioned above the transfer belt 38 and positioned above. That is, the warp suppressing portion 92 functions to suppress the warp of the transfer belt 38, and the abutting portion 98 is retracted so as not to disturb the normal belt operation.

  FIG. 9 is a side view showing the belt replacement posture of the interlocking mechanism 90 of another embodiment. When the transfer belt unit 24 is tilted in order to replace the transfer belt 38 (S200), the lower part of the main body 59 of the rocking body 58 comes into contact with the upper member 116 that extends from the drawer. . The lower part of the main body 59 of the oscillating body 58 rotates counterclockwise by contacting the upper member 116 (S202), and the upper part of the main body 59 of the oscillating body 58 also rotates counterclockwise (S204). That is, as shown in FIG. 9, the swinging body 58 is in a rising state (a rising posture). When the swinging body 58 is raised, the warp suppressing portion 92 of the first arm 94 is retracted from the transfer belt 38. Further, when the second arm 96 rises, a part of the abutting portion 98 is positioned above the transfer belt 38. Thus, when the new transfer belt 38 is attached, the transfer belt 38 can be easily attached to an accurate position by abutting the transfer belt 38 against the abutting portion 98 (reference surface).

  The interlocking mechanism 90 of another embodiment described above also realizes a configuration that satisfies the two needs of suppressing the warpage of the transfer belt 38 in the operating state of the transfer belt 38 and forming a reference surface when the transfer belt 38 is replaced. In this case, the configuration can be simplified as compared with the case where these functions are realized by completely separate mechanisms.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus, 16 Image forming part, 24 Transfer belt unit, 38 Transfer belt, 40 Primary transfer roll, 42 Drive roll, 44 Secondary transfer roll, 46 Support roll, 50 Drawer, 54 Interlock mechanism, 58 Oscillator, 59 Oscillating body main body, 60, 94 first arm, 62, 96 second arm, 72, 92 warpage suppressing portion, 74, 98 abutting portion, 76 abutting plate, 110 structure, 116 upper member.

Claims (8)

Including a transfer belt unit that takes a belt operating posture and a belt replacement posture,
The transfer belt unit is
A transfer belt that rotates,
An interlocking mechanism provided on the back side of the transfer belt unit;
Including
The interlocking mechanism is
An oscillating body that is in a forward-facing posture when the transfer belt unit takes the belt operating posture, and a rising-up posture in the back side when the transfer belt unit takes the belt replacement posture;
A warp suppressor configured as a part of the swinging body, protruding above the back end of the transfer belt in the collapsed posture to suppress warping of the back end, and being in a retracted state in the rising posture;
A part of the oscillating body or a member to which the oscillating motion of the oscillating body is transmitted is formed to form a reference surface against which the rear end portion of the transfer belt after replacement is abutted in the rising position, and in the falling position A butting portion that is in a retracted state;
An image forming apparatus comprising: The image forming apparatus according to claim 1.
The abutting portion includes an abutting plate to which the swing motion of the swing body is transmitted,
The rocking body and the butting plate are configured as separate members.
An image forming apparatus. The image forming apparatus according to claim 2.
The oscillator includes a main body and a plurality of arms branched from an upper portion of the main body,
The plurality of arms are
A first arm including a portion that functions as the warp suppressing portion;
A second arm having a working end for transmitting the rising motion of the rocking body directly or indirectly to the abutting plate;
An image forming apparatus comprising: The image forming apparatus according to claim 3.
When the working end of the second arm moves up, the abutment plate rises, and thereby one surface of the abutment plate functions as the reference surface,
When the working end of the second arm moves downward, the abutting plate sinks, whereby the abutting plate is in the retracted state.
An image forming apparatus. The image forming apparatus according to claim 1.
The abutting portion is configured as a part of the rocking body,
An image forming apparatus, wherein a main body of the rocking body, the warp suppressing portion, and the abutting portion are integrated. The image forming apparatus according to claim 5.
A plurality of arms branched from the upper part of the main body;
The plurality of arms are
A first arm including a portion that functions as the warp suppressing portion;
A second arm including a portion functioning as the abutting portion;
An image forming apparatus comprising: The image forming apparatus according to claim 1.
The belt operating posture is a non-tilting posture,
The belt replacement posture is an inclined posture generated by a rotational movement around a rotation axis on the back side of the transfer belt unit.
An image forming apparatus. The image forming apparatus according to claim 1.
A plurality of interlocking mechanisms are provided on the back side of the transfer belt unit in the transport direction of the transfer belt,
The plurality of interlocking mechanisms operate synchronously;
An image forming apparatus.

Images