JP3560201B2 - Paper peeling device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet peeling device for fixing a toner image transferred onto copy paper by heat or pressure in an image forming apparatus such as an electrophotographic copying machine.
[0002]
[Prior art]
In a roll-type fixing device, paper passing through a nip portion between a pair of fixing rolls composed of a roll and a pressure roll tends to wind around the fixing roll due to adhesiveness or the like generated when the toner is melted. is there. Conventionally, in order to prevent the paper from being wound, a peeling claw that comes into contact with the surface of the fixing roll is provided, and the sheet is peeled from the surface of the fixing roll with the tip of the peeling claw. Further, in the fixing device, when a jam (paper jam) occurs, a mechanism that allows the peeling claw to be retracted from the surface of the fixing roll is adopted so that the jam can be easily removed.
[0003]
[Problems to be solved by the invention]
However, since there is generally no space around the fixing device accommodating portion of the copying machine to sufficiently separate the peeling claw from the fixing roll, an operator touches the tip of the peeling claw when removing a jam. The hands could be touched and the hands could be injured.
[0004]
Therefore, in order to prevent the operator from being injured when removing jammed paper, when the peeling claw is retracted from the surface of the fixing roll, the tip of the peeling claw faces upward, and the operator's hand peels. Japanese Patent Publication No. 4-43268 discloses a paper peeling device that does not directly contact the tip of the nail.
[0005]
On the other hand, a fixing device or an image forming apparatus including a fixing device is unitized in order to facilitate removal of jammed paper and repair and maintenance of the copying machine. 2. Description of the Related Art A copier provided so as to be able to be pulled out in a direction is known.
[0006]
In a copying machine in which a unit including the fixing device is provided so as to be able to be pulled out from the copying machine main body, when the unit is pulled out from the copying machine main body, the upper surface of the fixing device is exposed to the outside. Therefore, when the paper peeling device described in the above publication is applied to this type of fixing device, the tip of the peeling claw faces upward when the peeling claw is retracted from the surface of the fixing roll. This is very dangerous when the operator including the fixing device pulls out the unit from the main body to perform maintenance and inspection.
[0007]
In order to prevent such a danger, it is conceivable to provide a cover member that covers the tip of the peeling claw. However, this increases the cost and increases the size of the unit including the fixing device.
[0008]
Further, in the paper peeling device described in the above publication, only the peeling claw for the heating roll can be retracted, so that when the paper is wound around the pressure roll side, it is difficult to remove the jammed paper. There is.
[0009]
Therefore, the present invention is to secure safety for an operator when a peeling claw is retracted from the surface of a fixing roll in a copying machine in which a unit including a fixing device is provided so as to be able to be pulled out from the copying machine body. Make it an issue. Another object of the present invention is to be able to easily cope with a jam on the pressure roll side.
[0010]
[Means for Solving the Problems]
The present invention is used in a fixing device in which at least one is a roll, the other is a pressure contact member that presses against the roll, and at least one is provided with a heat source and is provided so as to be able to be drawn out from the image forming apparatus main body. A paper peeling device, comprising: a roll peeling claw that contacts a surface of the roll; and a peeling claw for a pressing member that contacts a surface of the pressing member, wherein the roll and the pressing member are stored. rotatably attached to the frame, the free end side of the first support member and said first support member which may take the position to retract the roll peeling pawl from a position between the roll into contact with the roll when rotatably provided, and a second support member for supporting the roll peeling pawl, and the first support member is rotated to the retracted position of the roll peeling claws, Serial second support member the tip of the peeling claw for the rotated roll by its own weight, characterized in the direction wolfberry to the first support member side.
[0011]
Further, in the invention, it is preferable that a part of the second support member constitutes an upper paper guide plate of a pair of paper guide plates for guiding the paper passing between the roll and the pressure contact member. Features.
[0012]
The present invention, the pressure contact member for separating claw and the lower sheet guide plate of the pair of paper guide plate, and wherein the moving the second support member and to Tsu Na integrally.
[0013]
The present invention also provides a third support member rotatably provided with respect to the frame, for retracting the peeling claw for the press-contact member from the press-contact member, and a third support member rotatably provided on the third support member. A fourth support member for supporting the peeling claw for the pressure contact member, wherein when the third support member is rotated to the retracted position of the peeling claw for the pressure contact member, the fourth support member is moved by its own weight. tip of the pressure contact member for separating claw rotates is characterized the direction wolfberry to the third support member side.
[0014]
The present invention also provides a stopper for changing the direction of the fourth support member by colliding with a part of the frame when rotating the third support member to the normal position side. Is formed. Further, the present invention further includes a rotation support shaft rotatably supporting the second support member on the free end side of the first support member, wherein the roll peeling claw is provided with respect to the second support member. A coil spring is provided for urging a force in a direction in which a tip is directed to the first support member side.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the configuration of the sheet peeling device of the present invention will be described in detail based on an embodiment shown in the drawings.
[0016]
FIG. 1 is a schematic cross-sectional view showing the basic configuration of a copying machine to which the sheet peeling device of the present invention is applied. At the top of the copier, an image reader is mounted on a platen glass (not shown) to read an image of a document (not shown) whose back surface is covered with a platen cover 1 and convert the image into an electric image signal. The device 2 is arranged. The image signal from the image reading device 2 is supplied to the exposure device 3, and the exposure device 3 irradiates the photosensitive drum 4 with a laser beam modulated by the image signal. Since the surface of the photosensitive drum 4 is uniformly charged by the charging corotron 5, an electrostatic latent image is formed on the surface of the photosensitive drum 4 by exposure. This electrostatic latent image is developed by the developing device 6. In the present embodiment, a rotary developing device is used as the developing device 6, and four electrostatic latent images sequentially formed on the photosensitive drum 4 are converted into four color toners of yellow, magenta, cyan, and black. In order to form yellow, magenta, cyan, and black color toner images on the photosensitive drum 4. The transfer drum 7 is provided in pressure contact with the photosensitive drum 4.
[0017]
On the other hand, the paper fed from one of the paper feed trays 8a, 8b, 8c or the manual feed tray 8d is electrostatically attracted to the surface of the transfer drum 7 by the charging corotron 9. When the sheet passes through the nip between the photosensitive drum 4 and the transfer drum 7 according to the rotation of the transfer drum 7, the color toner image on the photosensitive drum 4 is transferred to the sheet on the transfer drum 7 by the transfer corotron 10. The paper on which the toner image of the first color (for example, yellow) has been transferred passes through the charge removing corotron 11 with the rotation of the transfer drum 7, and the charge on the transfer drum surface is erased. The toner is sent to the nip portion of the transfer drum 7, and the color toner image of the second color (for example, magenta) is transferred to the sheet on the transfer drum 7. Similarly, the color toner images of the third color (for example, cyan) and the fourth color (for example, black) are transferred to the paper on the transfer drum 7 every one rotation of the transfer drum 7, and the four color toner images are printed on the paper. The toner images are transferred in a multiplex manner to form a full-color toner image.
[0018]
The paper on which the full-color toner image is formed is peeled off from the surface of the transfer drum 7 by the peeling corotron 12, passes through the nip between the heating roll 14 and the pressure roll 15 of the fixing device 13, and undergoes a fixing process. After that, it is discharged to the copy receiver 16.
[0019]
In the copying machine shown in FIG. 1, the transfer drum 7 and its peripheral parts are integrally formed as a transfer unit 17, and the heating roll 14 and the pressure roll 15 of the fixing device 13 and the peripheral parts are formed as a fixing unit. 18 are integrally formed. Then, the transfer unit 17 and the fixing unit 18 can be pulled out in the front-rear direction with respect to the copying machine main body.
[0020]
FIG. 2 is a perspective view showing a state where the transfer unit 17 and the fixing unit 18 are pulled out from the copying machine main body. The fixing unit 18 is integrally formed with the transfer unit 17 in a state of being attached to the transfer unit 17, and the transfer unit 17 and the fixing unit 18 are copied between a lower portion of the transfer unit 17 and the copying machine main body. A telescopic rail 19 is provided to allow the front and rear sides to be pulled out of the machine body.
[0021]
The transfer unit 17 and the fixing unit 18 open the front cover 20 provided on the front surface of the copier main body so as to be openable and closable, and rotate the lever 21 in a predetermined direction to connect the transfer unit 17 and the fixing unit 18 to the copier main body. By releasing the locked state between them and pulling the lever 21 forward, the lever 21 can be pulled forward from the copier body.
[0022]
Hereinafter, several embodiments of the sheet peeling device used in the above-described fixing unit 18 will be described.
[0023]
[Example 1]
FIG. 3 is a schematic sectional view showing Embodiment 1 of the paper peeling device of the present invention. A heating roll 14 and a pressure roll 15 are provided in pressure contact with each other inside a frame 22 constituting a housing of the fixing unit 18. A plate-like first support member 23 is provided on the side surface of the fixing unit 18 in the sheet discharging direction so as to be openable and closable with respect to the fixing unit 18. The base end of the first support member 23 is rotatably supported by the upper end of the frame 22 on the sheet discharge side via a rotation support shaft 24. A second support member 25 is rotatably supported by a support plate 39 formed at the free end of the first support member 23 via a rotation support shaft 26. One end 27a of the second support member 25 is bent in an L shape, and an L-shaped peeling claw support arm 28 is attached to the other end 27b via a rotation support shaft 29. I have. At one end of the peeling claw support arm 28, a heating roll peeling claw 30 that is in contact with the surface of the heating roll 14 is attached, and is formed at the other end, the rotation support shaft 26, and the second support member 25. A tension spring 32 is stretched between the hooks 31. Further, a leaf spring 33 is provided on the second support member 25 so as to cover the other end of the peeling claw support arm 28. Further, a stopper 35 projecting from a part of the support plate 34 supported by the rotation support shaft 26 of the second support member 25 in a direction perpendicular to the paper surface is formed. Further, a tie bar 36 is provided near the rotation support shaft 26 and connected between a pair of frames 22 arranged at a certain interval in a direction perpendicular to the paper surface. The pressure roller 15 is also provided with a pressure roller peeling claw 38 about the rotation support shaft 37 as a rotation center.
[0024]
An upper paper guide plate 40 is integrally formed at the end of the second support member 25 on the side of the peeling claw 30 for the heating roll, and a lower paper guide plate 41 is provided on the side of the pressure roll 15 with a frame 22. Provided in a fixed state with respect to.
[0025]
Next, the operation of the sheet peeling apparatus according to the first embodiment of the present invention shown in FIG. 3 will be described. During normal operation, the first support member 23 and the second support member 25 are in the normal position indicated by the reference symbol A, and the tip of the peeling claw 30 for a heating roll is in a state of contacting the surface of the heating roll 14. . In addition, the tip of the pressure roll peeling claw 38 is in a state of being constantly in contact with the surface of the pressure roll 15. Therefore, even if the paper that has passed through the nip between the heating roll 14 and the pressure roll 15 is stuck to the surface of the heating roll 14 or the pressure roll 15, unless the sticking is very strong, the heating The peeling can be performed by the roll peeling claw 30 or the pressure roll peeling claw 38. The paper that has passed through the nip between the heating roll 14 and the pressure roll 15 is guided by the upper paper guide plate 40 and the lower paper guide plate 41 and discharged to the paper receiver 16.
[0026]
Next, if a paper jam occurs for some reason, the first support member 23 is rotated clockwise in the figure around the rotation support shaft 24 to rotate to the retracted position indicated by the symbol B. In the drawings, the dash is attached to the reference numeral of each member at the retracted position. At this time, the second support member 25 rotates counterclockwise by its own weight about the rotation support shaft 26, and the stopper 35 formed on the second support member 25 causes the first support member 23 to play. By colliding with the support plate 39 formed at the end, the attitude of the second support member 25 is determined. As a result, the tip of the heating roll peeling claw 30 faces the first support member 23 side, that is, the lower side. Therefore, even when the operator brings his hand close to the fixing device in order to remove the jammed sheet, his / her hand does not touch the tip of the peeling claw 30 for the heating roll, and does not get injured.
[0027]
Next, after the jammed paper is removed, the first support member 23 is rotated counterclockwise about the rotation support shaft 24 to return to the original position. The provided leaf spring 33 comes into contact with the tie bar 36 to push down the heating roll peeling claw 30 downward. Accordingly, the tip of the heating roll peeling claw 30 does not collide with the surface of the heating roll 14 at an angle close to a right angle, and it is possible to prevent the surface of the heating roll 14 from being damaged.
[0028]
[Example 2]
FIG. 4 is a schematic sectional view showing Embodiment 2 of the paper peeling device of the present invention. The members corresponding to those in the first embodiment are denoted by the same reference numerals.
[0029]
In the first embodiment, the second support member 25 is rotated by its own weight when the first support member 23 is rotated to the retreat position around the rotation support shaft 24. 2, the coil spring 42 is provided on the rotation support shaft 26, and the coil spring 42 is provided in the counterclockwise direction with respect to the second support member 25, that is, in the direction in which the tip of the heating roll peeling claw 30 faces the first support member 23 side. We are energizing. Accordingly, the second support member 25 receives not only its own weight but also the force of the coil spring 42 when in the retracted position, so that the tip of the peeling claw 30 for the heating roll is securely moved to the first support member 23 side. Can turn. However, the strength of the coil spring 42 is set to such a strength that the first support member 23 is pushed back by its own weight to the second support member 25 when returning to the normal position.
[0030]
[Example 3]
FIG. 5 is a schematic sectional view showing Embodiment 3 of the paper peeling device of the present invention. The members corresponding to those in the first embodiment are denoted by the same reference numerals.
[0031]
In the third embodiment, the end of the second support member 25 on the side of the peeling claw 30 for a heating roll is extended to form an extension 43. A pressure roll peeling claw 38 is provided.
[0032]
In the normal state, the first supporting member, the second supporting member, the peeling claw for the heating roll 14, and the peeling claw for the pressure roll 15 are located at positions indicated by reference numerals 23, 25, 30, and 38, respectively. When a paper jam occurs, the first support member 23 is rotated about the rotation support shaft 24 to the retracted position. At this time, the second support member 25 rotates by its own weight around the rotation support shaft 26, and the stopper 35 formed on the second support member 25 is formed at the free end of the first support member 23. The second support member 25 stops after colliding with the supported support plate 39.
[0033]
In the third embodiment, since the peeling claw 38 for the pressure roll for the pressure roll 15 also retreats together with the peeling claw 30 for the heating roll for the heating roll 14, a paper jam occurs on the pressure roll 15 side. But it can be easily removed.
[0034]
[Example 4]
FIG. 6 is a schematic sectional view showing Embodiment 4 of the paper peeling device of the present invention. The members corresponding to those in the first embodiment are denoted by the same reference numerals.
[0035]
The retracting mechanism of the heating roll peeling claw 30 for the heating roll 14 in the fourth embodiment is the same as that shown in the first embodiment.
[0036]
In the fourth embodiment, the base end of the third support member 44 is rotatably supported via a rotation support shaft 45 at the lower end of the frame 22 on the paper discharge side. A base end of a fourth support member 47 is rotatably supported via a rotation support shaft 48 at a distal end of a lever portion 46 integrated with the third support member 44. A lever 49 and a lower paper guide plate 50 are formed integrally with the fourth support member 47. A stopper 51 projecting in a direction perpendicular to the paper surface is formed at an end of the lower paper guide plate 50 on the downstream side in the paper transport direction. Further, a separation claw 38 for a pressure roll is rotatably supported by a support plate 52 formed integrally with the fourth support member 47 via a rotation support shaft 37.
[0037]
In a normal state, the peeling claw 30 for the heating roll and the peeling claw 38 for the pressure roll are in contact with the heating roll 14 and the pressure roll 15, and peel the paper from the heating roll 14 and the pressure roll 15. .
[0038]
When a paper jam occurs, the operator holds the lever unit 46 integrated with the support member 44 by hand and rotates the rotation support shaft 45 to the retreat position as shown in FIG. At this time, the fourth support member 47 rotates clockwise in the figure by its own weight around the rotation support shaft 48, so that the fourth support member 47 assumes a position indicated by reference numeral C in FIG. The leading end faces the inside of the fixing unit 18. Therefore, even if a paper jam occurs in the pressure roll 15, the jammed paper can be easily removed. In addition, the tip of the peeling claw 54 is not touched by the operator's hand, which is safe.
[0039]
Next, after removing the jammed sheet, the operator holds the lever 49 formed integrally with the fourth support member 47 by hand, and returns the lever 49 to the normal position around the rotation support shaft 45. The stopper 51 provided on the fourth support member 47 collides with the frame 22, as indicated by reference numeral D in FIG. 7, and thereafter, the fourth support member 47 contacts the frame 51 with the stopper 51. It rotates counterclockwise about the position as the center of rotation. Therefore, the direction of the tip of the peeling claw 54 changes from the lower right direction to the upper right direction, and contacts the surface of the pressure roll 15 along the surface of the pressure roll 15 as shown in FIG. Accordingly, the tip of the peeling claw 54 does not collide with the surface of the pressure roll 15 at an angle close to a right angle, and it is possible to prevent the surface of the pressure roll 15 from being damaged.
[0040]
In the above-described embodiment, the fixing unit 18 is integrally formed with the transfer unit 17 while being attached to the transfer unit 17, so that the fixing unit 18 and the transfer unit 17 are simultaneously drawn out. However, the present invention can be applied to a device in which the fixing unit and the transfer unit 17 can be pulled out independently, or a device in which only the fixing unit 18 can be pulled out.
[0041]
【The invention's effect】
According to the paper peeling apparatus of the present invention, when the peeling claw is moved to the retracted position, the tip of the peeling claw does not face upward, so that the unit including the fixing device can be pulled out from the image forming apparatus main body. Also in the apparatus, the operator's hand does not touch the tip of the peeling claw when the jammed paper is removed, so that the safety of the operator can be ensured. Also, paper jams in the pressure roll can be easily removed.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing a basic configuration of a copying machine to which a sheet peeling device of the present invention is applied.
FIG. 2 is a perspective view showing a state in which a transfer unit and a fixing unit are pulled out from a copying machine main body.
FIG. 3 is a schematic sectional view showing Embodiment 1 of the paper peeling device of the present invention.
FIG. 4 is a schematic sectional view showing a second embodiment of the paper peeling device of the present invention.
FIG. 5 is a schematic sectional view showing Embodiment 4 of the paper peeling device of the present invention.
FIG. 6 is a schematic sectional view showing a normal state of Embodiment 5 of the paper peeling device of the present invention.
FIG. 7 is a schematic sectional view showing a retracted state of a sheet peeling apparatus according to a fifth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Platen cover, 2 ... Image reading device, 3 ... Exposure device, 4 ... Photoconductor drum, 5 ... Charging corotron, 6 ... Developing device, 7 ... Transfer drum, 8a, 8b, 8c ... Feeding tray, 9 ... Charging Corotron, 10 transfer corotron ..., 11 ... Charge removing corotron, 12 ... Peeling corotron, 13 ... Fixing device, 14 ... Heating roll, 15 ... Pressing roll, 16 ... Copy receiving, 17 ... Transfer unit, 18 ... Fixing unit, 19 ... Telescopic rails, 20 ... front cover, 21 ... lever, 22 ... frame, 23 ... first support member, 24 ... rotation support shaft, 25 ... second support member, 26 ... rotation support shaft, 27a, 27b ... end , 28: peeling claw support arm, 29: rotary support shaft, 30: peeling claw, 31: hook, 32: tension spring, 33: leaf spring, 34: support plate, 35: stopper, 36: tie bar 37: rotation support shaft, 38: peeling claw, 39: support plate, 40: upper paper guide plate, 41: lower paper guide plate, 42: coil spring, 43: extension, 44: third support member, 45 ... Rotation support shaft, 46: lever portion, 47: fourth support member, 48: rotation support shaft, 49: lever portion, 50: lower paper guide plate, 51: stopper, 52: support plate

Claims (6)

At least one is a roll, the other is a pressure contact member that presses against the roll, and a paper peeling device used in a fixing device that is provided with a heat source on at least one side and that can be pulled out from the image forming apparatus main body. A paper peeling device comprising a roll peeling claw that contacts the surface of the roll and a press-contact member peeling claw that contacts the surface of the press-contact member.
Provided so as to be rotatable with respect to the roll and the frame for housing the pressing member, a first support member which may take the position to retract the roll peeling pawl from a position between the roll into contact with the roll,
A second support member rotatably provided on the free end side of the first support member and supporting the roll peeling claw;
When the first support member is rotated to the retracted position of the roll peeling claw, the second support member is rotated by its own weight, and the tip of the roll peeling claw is on the first support member side. paper stripping device comprising a countercurrent wolfberry to. A part of the second support member constitutes an upper sheet guide plate of a pair of sheet guide plates for guiding a sheet passing between the roll and the pressing member. sheet peeling apparatus according to 1. Paper stripping of claim 2 wherein the lower sheet guide plate of the pressure contact member for separating claw and the pair of paper guide plate, and wherein the moving the second support member and to integrally Tsu Na apparatus. A third support member rotatably provided with respect to the frame, for retracting the peeling claw for the pressure contact member from the pressure contact member; and a third support member rotatably provided on the third support member, A fourth support member for supporting the peeling claw;
When the third support member is rotated to the retracted position of the peeling claw for the pressing member, the fourth support member rotates by its own weight, and the tip of the peeling claw for the pressing member becomes the third support. sheet peeling device of claim 1, wherein the direction wolfberry to member. The fourth support member is provided with a stopper that collides with a part of the frame to change the direction of the fourth support member when the third support member is rotated to the normal position. The paper peeling device according to claim 4, wherein: The rotation support shaft rotatably supporting the second support member at the free end side of the first support member has a tip of the roll peeling claw with respect to the second support member. The sheet peeling device according to claim 1, further comprising a coil spring for urging a force in a direction toward the supporting member.

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