JP2018205383A - Image formation device - Google Patents

Abstract

To provide an image formation device capable of securing safety in such a constitution that a toggle arms presses an interlock switch.SOLUTION: At a toggle arm 3, an action part 3c acting on an interlock switch 5 is provided. Between a first phase that is at a position of the toggle arm 3 when an opening/closing member 1 is opened, and a second phase that is at the position of the toggle arm 3 when the opening/closing member 1 is closed, an ON/OFF state of the interlock switch 5 is different. In a third phase that the toggle arm 3 turns in a reverse direction to a first phase side with respect to the second phase, the ON/OFF state of the interlock switch 5 is identical to that in the first phase.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an image forming apparatus such as a copying machine or a printer.

  The image forming apparatus is provided with a door for removing jammed paper in case the paper to be printed is jammed in the conveyance path. When the door is opened, the paper transport path is opened to the user. At this time, the user may be able to access the high voltage application portion in the apparatus. Therefore, in general, the image forming apparatus includes an interlock switch that shuts off the power supply in conjunction with the opening of the door (Patent Document 1).

JP 2009-198708 A

  By the way, the reaction force of the interlock switch applied to the door causes an increase in the level difference in the gap portion between the door and the surrounding exterior cover, and causes creep deformation of the door. Therefore, it is conceivable to prevent the door from being deformed by adopting a configuration in which the reaction force of the interlock switch does not act on the door. For example, it can be considered that the door is pulled into the main body using a toggle mechanism. A toggle arm is provided on the main body and a toggle hook is provided on the door. When the door is closed, the toggle hook pushes the toggle arm, and when the toggle arm exceeds the critical point (dead point), the toggle arm generates a force for pulling the door. Then, by providing the toggle arm with a portion that acts on the interlock switch provided on the main body, the reaction force of the interlock switch does not act on the door.

  However, the case where the original function of the interlock switch does not work due to the fact that the interlock switch is pushed by the toggle arm must be avoided.

  An object of the present invention is to provide an image forming apparatus that ensures safety in a configuration in which an interlock switch is pushed by a toggle arm.

  The present invention for solving the above-described problems includes a main body of an image forming apparatus, an opening / closing member provided to be openable / closable with respect to the main body, and the opening / closing member provided on the main body by a biasing force of a toggle spring. A toggle mechanism that generates a pulling force to a closed position, an engagement member that is provided on the opening / closing member and engages a toggle arm of the toggle mechanism, and an interlock switch provided on the main body. In accordance with opening / closing of the opening / closing member, the engagement state of the toggle arm and the engaging member is switched, whereby the rotation phase of the toggle arm is switched, and the urging direction by the toggle spring is switched. In the device, the toggle arm is provided with an action portion acting on the interlock switch, and the first action phase is a phase of the action portion when the opening / closing member is in an open position The ON / OFF state of the interlock switch is different between the phase and the second phase that is the phase of the action portion when the opening and closing member is in the closed position, and the action portion is more than the second phase. In the third phase rotated in the direction opposite to the first phase side, the ON / OFF state of the interlock switch is the same as that in the first phase.

  According to the present invention, it is possible to provide an image forming apparatus that ensures safety in a configuration in which an interlock switch is pushed by a toggle arm.

Cross section of image forming apparatus The figure which showed the relationship between a toggle mechanism and an interlock switch based on Example 1. FIG. FIG. 6 is a perspective view of an image forming apparatus according to a second embodiment. The figure which showed the relationship between a toggle mechanism and an interlock switch based on Example 2. FIG.

Example 1
FIG. 1 is a cross-sectional view of a color laser printer which is an example of an image forming apparatus. Reference numeral 100 denotes a main body of the image forming apparatus. Reference numeral 100A denotes an image forming unit that is provided in the main body 100 of the image forming apparatus and forms an image on the sheet S by an electrophotographic method. 101Y, 101M, 101C, and 101B are drum-shaped photoconductors for four colors of yellow, magenta, cyan, and black. Reference numerals 104Y, 104M, 104C, and 104B denote developing devices that supply toner to the photoreceptor and develop the latent image formed on the surface of the photoreceptor. An intermediate transfer belt 102 is in contact with each photoconductor and onto which the toner images formed on the photoconductors 101Y, 101M, 101C, and 101B are primarily transferred. 106Y, 106M, 106S, and 106B are primary transfer rollers that primarily transfer a toner image by generating a potential difference between the photoreceptors 101Y, 101M, 101C, and 101B and the intermediate transfer belt 102. Reference numeral 105 denotes a secondary transfer roller that forms a nip with the outer peripheral side of the intermediate transfer belt 102 and secondarily transfers the image transferred to the intermediate transfer belt 102 onto the sheet S. The image forming unit 100A includes these components.

  When an image forming operation is started in the image forming unit 100A, the laser scanner 103 irradiates light corresponding to the image signal onto the photoconductors 101Y, 101M, 101C, and 101B charged by a charger (not shown). Thereby, electrostatic latent images are formed on the photoreceptors 101Y, 101M, 101C, and 101B. The latent image is developed with toner stored in the developing devices 104Y, 104M, 104S, and 104B. The toner images formed on the photoreceptors 101Y, 101M, 101C, and 101B are primarily transferred to the intermediate transfer belt 102. The toner image transferred to the intermediate transfer belt 102 is conveyed by the intermediate transfer belt 102 to the secondary transfer portion.

  In parallel with the toner image forming operation, the sheet S is fed from the sheet storage unit 107 by the pickup roller 108 one by one. The sheet S is conveyed to a secondary transfer portion formed by a nip between the intermediate transfer belt 102 and the secondary transfer roller 105 by a feed roller 109 and a registration roller 110 that performs skew correction of the sheet S. Here, the sheet S needs to be aligned with the toner image formed on the intermediate transfer belt 102 in the sheet conveyance direction. Therefore, the sheet S is aligned with the toner image by controlling the conveying speed of the registration roller 110 and the feed roller 109. The toner image is transferred from the intermediate transfer belt 102 to the sheet S by applying a bias to the secondary transfer roller 105 at the secondary transfer portion. Thereafter, the sheet S on which the toner image is transferred is conveyed to the fixing unit 111. The toner image is fixed on the sheet S by being heated and pressed by the fixing unit 111. After fixing, the sheet S is discharged to the tray 113 at the top of the apparatus by the discharge roller 112.

  FIG. 1B is a cross-sectional view showing a state in which a door (opening / closing member) 1 provided to be openable / closable with respect to the main body 100 is opened. The door 1 is opened when the sheet S is jammed in the sheet conveyance path in the main body 100 and it is necessary to remove the jammed paper inside.

  The main body 100 has a toggle arm 3 of a toggle mechanism that generates a force for pulling the door 1 to the closed position by the urging force of the toggle spring 4, and the door 1 has a toggle hook (engagement member) that engages with the toggle arm 3 of the toggle mechanism. 2 is provided. When the door 1 is closed, the toggle hook 2 pushes the toggle arm 3, and when the toggle arm 3 exceeds the critical point (dead point), the toggle arm 3 generates a force that pulls the door 1 into the main body 100. That is, the engagement state of the toggle arm 3 and the toggle hook 2 is switched according to the opening and closing of the door 1, whereby the rotation phase of the toggle arm 3 is switched and the urging direction by the toggle spring 4 is switched. The main body 100 is provided with an interlock switch 5 (see FIG. 2). By providing the toggle arm 3 with a portion (action portion) that acts on the interlock switch 5, the reaction force of the interlock switch 3 does not act on the door 1.

  When the door 1 is opened, the sheet conveyance path from the vicinity of the registration roller 110 to the second transfer unit is exposed. The toggle hook 2 provided on the door 1 is pulled in by the toggle arm 3 provided on the main body, whereby the door 1 is maintained in the closed state of FIG.

  FIG. 2 is a cross-sectional view showing the operation of the toggle mechanism and the interlock switch 5 that pulls the door in the direction in which the door 1 is closed. The interlock switch 5 is a switch that shuts off the power supply in conjunction with the opening of the door, and is a safety device that, when turned off, stops the main power supply flowing to the actuator, motor, bias contact, and the like.

  FIG. 2A is a diagram illustrating a state in which the door 1 is closed. At this time, the toggle arm 3 rotatably held around the rotation shaft 3a generates a force that rotates counterclockwise in FIG. 2 due to the tension of the toggle spring 4 hung on the spring hanging shaft 3b. Yes. With this force, the toggle hook 2 is pushed in the left direction in the figure (retracted), and the door 1 is urged in the closing direction. Since the contact cam 3c provided on the toggle arm 3 pushes the lever of the interlock switch 5, the interlock switch 5 is turned on. At this time, the hook engaging portion 3d of the toggle arm 3 abuts against the engaging portion 2a provided on the toggle hook 2. Thereby, the counterclockwise rotation of the toggle arm is restricted. The phase of the toggle arm 3 at this time is defined as a second phase.

  FIG. 2B is a diagram showing a state in which the door 1 is opened. When shifting from the state shown in FIG. 2A to the state shown in FIG. 2B, the toggle arm 3 is rotated clockwise by the toggle hook 2 as the opening angle of the door 1 increases. At the time of FIG. 2 (b), the toggle arm 3 is moved in the clockwise direction in FIG. 2 from the critical point (dead point) of the toggle arm 3 in which the rotation shaft 3a, the spring hook 3b and the spring hook 6 are aligned. Waiting in the rotated position. At this time, since the contact cam 3c is separated from the interlock switch 5, the interlock switch 5 is turned off. When the door 1 is closed from this state where the door 1 is opened, the toggle arm 3 is rotated counterclockwise by the toggle hook 2 pushing the hook engaging portion 3d. When the toggle arm 3 exceeds the critical point, the door 1 is pulled toward the state shown in FIG. The phase of the toggle arm 3 when the door is in the open position is defined as a first phase.

  FIG. 2C is a diagram illustrating a case where the user accidentally damaged the engaging portion 2 a of the toggle hook 2 when the door 1 is opened. FIG. 2C shows the state of the toggle arm 3 and the interlock switch 5 when the door 1 is closed. As shown in FIG. 2A, when the door 1 is closed in a state where the engaging portion 2a of the toggle hook 2 is not damaged, the toggle arm 3 is rotated counterclockwise by the urging force of the toggle spring 4. It is regulated by the engaging portion 2a. However, when the engaging portion 2a of the toggle hook 2 is broken as shown in FIG. 2C, the rotation of the toggle arm 3 in the counterclockwise direction cannot be restricted by the engaging portion 2a. Accordingly, the toggle arm 3 is rotated beyond the position shown in FIG. 2A by the urging force of the toggle spring 4. Even in the position beyond the position of FIG. 2A, the toggle switch 5 may be pushed by the toggle arm 3 and the switch may be turned on. Even if the door 1 is opened in this state, the toggle arm 3 cannot be rotated clockwise because the engaging portion 2a is broken. Therefore, a state occurs in which the interlock switch 5 is turned on even though the door 1 is open.

  Therefore, in this embodiment, as shown in FIG. 2C, when the toggle arm 3 is rotated beyond the position (second phase) of FIG. 2A by the biasing force of the toggle spring 4, the interlock switch 5 Is turned off. In other words, when the toggle arm 3 overruns without stopping at the normal stop position (second phase) where the interlock switch is turned on, the interlock switch 5 or the toggle arm 3 is turned off so that the interlock switch 5 is turned off. The layout is set. 2 in FIG. 2 is a stopper (regulating member) that regulates the rotation of the toggle arm 3. The stopper 7 also has a role of a positioning unit that determines the phase of the toggle arm 3 to the third phase (phase where the interlock switch 5 is turned off) shown in FIG.

  In this way, the toggle arm 3 that is not locked by the toggle hook 2 rotates to a position where it abuts against the stopper 7. When the toggle arm 3 rotates to this phase, the contact cam 3c moves to a position away from the contact with the lever of the interlock switch 5, so that the interlock switch is turned OFF.

  As described above, the apparatus of this example has the first phase that is the phase of the action part 3c when the door 1 is in the open position and the second phase that is the phase of the action part 3c when the door 1 is in the closed position. The ON / OFF state of the interlock switch 5 differs depending on the phase. In the third phase in which the action part 3c is rotated in the direction opposite to the first phase side relative to the second phase, the ON / OFF state of the interlock switch 5 is the same as in the first phase. become.

  Therefore, it is possible to prevent the interlock switch 5 from being turned on even though the door 1 is open.

(Example 2)
The same configurations and operations as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted. FIG. 3 is a perspective view of the image forming apparatus according to the second embodiment. The image forming apparatus according to the second exemplary embodiment is opened when a CRG (cartridge: a unit in which a photosensitive member and a developing device are unitized) is replaced in addition to the door 1 (first door, first opening / closing member). Door (second opening / closing member) 10. The door 10 is provided on the front surface of the main body 100.

  FIG. 4 explains the operation of the toggle mechanism that performs ON / OFF switching of the interlock switch 5 and the toggle mechanism that pulls in the first door 1 in the closing direction of the first door 1 as in the first embodiment. It is sectional drawing. The interlock lever mechanism turns on the interlock switch 5 only when both the first door 1 and the second door 10 are closed, and turns off when one or both doors are open. Mechanism. The interlock lever mechanism includes an interlock lever (first lever) 8 and an interlock lever (second lever) 9. The first lever 8 and the second lever 9 are provided in the main body 100 of the image forming apparatus. The second lever 9 is held by the first lever 8 so as to be rotatable around the lever rotation shaft 9a, and the first lever 8 is held by the main body frame so as to be able to swing around the swing shaft 8a. Yes. The second lever 9 is an action portion that acts on the interlock switch 5.

  FIG. 4A shows a state where both the first door 1 and the second door 10 are closed. The swing position of the first lever 8 changes depending on the presence or absence of the protrusion 11 provided on the second door 10. When the second door 10 is in a closed state, the first lever 8 moves to the first swing position shown in FIG. And the 2nd lever 9 hold | maintained at the 1st lever 8 is lifted by the contact cam 3c of the toggle arm 3, and rotates around the rotating shaft 9a. As a result, the interlock switch 5 is turned on.

  FIG. 4B shows a state where the first door 1 of the main body 100 is closed and a state where the second door 10 is opened. When the second door 10 is opened, the abutment of the protrusion 11 holding the first lever 8 is released. As a result, the first lever 8 moves to the second swing position shown in FIG. Since the second lever 9 also swings together with the first lever 8, the contact state between the second lever 9 and the interlock switch 5 is released. As a result, the interlock switch 5 is turned off.

  FIG. 4C shows a state where the first door 1 of the main body 100 is opened and a state where the second door 10 is closed. At this time, the first lever 8 comes into contact with the protrusion 11 and the first lever 8 is located at the first swing position. When the first door 1 is opened, the toggle arm 3 rotates to a position slightly beyond the critical point of the toggle arm 3 in which the rotation shaft 3a, the spring hooking portion 3b, and the spring hooking shaft 6 are aligned. And since the contact cam 3c leaves | separates from the 2nd lever 9, the force which presses the interlock switch 5 to an ON position is released, and the interlock switch 5 moves to OFF by the force of the spring incorporated in itself.

  FIG. 4D shows that the user accidentally damaged the engaging portion 2a of the toggle hook 2 when the second door 10 of the main body 100 is closed and the first door 1 is opened. Shows the case. Since there is no rotation restriction of the toggle arm 3 by the engaging portion 2 a of the toggle hook 2, the toggle arm 3 rotates to a position where it abuts against the stopper 7. At this time, since the contact of the contact cam 3c that presses one end of the second lever 9 is released, the second lever 9 can be freely rotated. Thereby, since the urging force to the interlock switch 5 is lost, the interlock switch 5 moves to the OFF position by the force of the spring built in itself. Therefore, it is possible to prevent the interlock switch 5 from being turned on even though the door 1 is open.

DESCRIPTION OF SYMBOLS 1 Door 2 Toggle hook 2a Engagement part 3 Toggle arm 3c Contact cam 4 Toggle spring 5 Interlock switch 7 Stopper

Claims (2)

A main body of the image forming apparatus;
An opening and closing member provided to be openable and closable with respect to the main body;
A toggle mechanism that is provided in the main body and generates a force for pulling the opening and closing member to a closed position by a biasing force of a toggle spring;
An engagement member provided on the opening / closing member and engaged with a toggle arm of the toggle mechanism;
An interlock switch provided in the main body;
The engagement state of the toggle arm and the engagement member is switched according to the opening / closing of the opening / closing member, whereby the rotation phase of the toggle arm is switched, and the biasing direction by the toggle spring is switched. In the image forming apparatus
The toggle arm is provided with an action portion that acts on the interlock switch,
A first phase that is a phase of the action portion when the opening and closing member is in an open position and a second phase that is a phase of the action portion when the opening and closing member is in a closed position are included in the interlock switch. ON / OFF state is different,
In the third phase in which the operating portion is rotated in the direction opposite to the first phase side than the second phase, the ON / OFF state of the interlock switch is the first phase. An image forming apparatus characterized by being the same.   The image forming apparatus according to claim 1, further comprising a regulating member that determines the phase of the toggle arm as the third phase.

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