JP2003186340A - Fixing device of image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a low cost and space saving by composing a releasing means and a resetting means of a swing member that is one member. <P>SOLUTION: A fixing device of an image forming apparatus 118 is provided with a releasing means 70 for releasing pressurization of a pressurizing means 50 bringing a transfer material into contact with a heating means 1 for heating the transfer material carrying a toner image with pressure. When paper is removed in paper clogging, one end constituting the releasing means 70 for releasing the pressurization of the pressurizing means 50 is made a supporting point, the swing member provided with a projection part 18 projected on a part of the swing member constituting the resetting means 180 restored to a position before pressurization releasing after clogged paper is removed is composed of a lever member 7 engaged with one end of a swinging cover member 11, two cams 17 and 18 projected in the pressurizing means side are provided at different positions, one cam 17 constitutes the releasing means 70, and the other cam 18 constitutes the resetting means 180. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to heating means for heating a transfer material carrying a toner image, pressurizing means for pressing the transfer material against the heating means, and pressurizing by the pressurizing means. The present invention relates to a fixing device of an image forming apparatus, which is provided with a releasing means for releasing the toner, and fixes the toner image on the transfer material by passing the transfer material between the heating means and the pressing means.

[0002]

2. Description of the Related Art A conventional fixing device for an image forming apparatus (Japanese Patent Laid-Open No. 9-212030) is designed to release pressure when removing paper.
The operator operates the lever to use the toothless gear K and the one-way gear O in order to maintain the released state as shown in FIG. 12, and automatically restarts the pressurization after the paper is removed. In order to perform the automatic restart, the toothless gear and the one-way gear used to hold the released state were used.

[0003]

Since the above-mentioned conventional fixing device of the image forming apparatus uses the toothless gear K and the one-way gear O, the number of parts is increased, the cost is increased, and the number of parts is increased. However, there is a problem that space is also disadvantageous because there are many cases.

Therefore, the inventor of the present invention applies heating means for heating the transfer material carrying the toner image, pressurizing means for pressing the transfer material to the heating means, and releasing the pressurizing means. In a fixing device of an image forming apparatus, which is provided with a releasing means and passes the transfer material between the heating means and the pressing means to fix the toner image on the transfer material, the releasing operation is performed when the paper, that is, the paper is sometimes removed. By means of a swing member having one end as a fulcrum, the pressure of the pressure means is released, the jammed paper is removed, and after the pressure is restored, the protrusion is projected to a part of the swing member. In view of the technical idea of the present invention of returning the position of the rocking member before the pressure is released after the pressure of the pressure means is restored, as a result of further research and development, the pressure of the pressure means is increased. The releasing means for releasing the A return means for returning the position prior to releasing the pressure, by configuring by the swing member is a single member, thereby achieving the present invention to achieve the object of realizing a low-cost, space saving.

[0005]

A fixing device of an image forming apparatus according to the present invention (a first invention according to claim 1) is a heating means for heating a transfer material carrying a toner image, and the heating means. A pressurizing means for pressing the transfer material into contact with the transfer material, and a releasing means for releasing the pressurization of the pressurizing means. The toner image is transferred by passing the transfer material between the heating means and the pressurizing means. In a fixing device of an image forming apparatus for fixing to a sheet, the releasing means for releasing the pressure of the pressing means when removing the paper, that is, sometimes the paper is constituted by a swing member having one end as a fulcrum, and the jammed paper is formed. After removing the pressure, the restoring means for returning the pressure of the pressure means to the position of the swinging member before releasing the pressure is constituted by a protruding portion projecting to a part of the swinging member. is there.

A fixing device for an image forming apparatus according to the present invention (a second invention according to claim 2) is the lever member according to the first invention, wherein the swing member is engaged with one end of a swing cover member. And two cams protruding toward the pressing means at different positions, one of the cams constitutes the releasing means, and the other cam releases the pressure of the lever member after the pressure is restored. It constitutes a returning means for returning to the front.

[0007]

According to the fixing device of the image forming apparatus of the first invention having the above-mentioned structure, when the paper, that is, the paper is sometimes removed, the adding member is constituted by the swinging member having one end constituting the releasing means as a fulcrum. After the pressure of the pressure means is released, the jammed paper is removed, and after the pressure is restored, the released pressure of the pressure means is restored by the protruding portion that is projected on a part of the swing member,
Since the position of the rocking member is returned before the pressure is released, the returning means for returning the position of the rocking member before the pressure is released after returning the pressure of the pressure means is one member. By using the swing member, it is possible to achieve an effect of realizing low cost and space saving.

In the fixing device of the image forming apparatus of the second invention having the above-mentioned structure, in the first invention, at different positions in the lever member engaging with one end of the swinging cover member constituting the swinging member. One of the cams forming the releasing means of the two cams protruding toward the pressing means releases the pressure of the pressing means, and the other cam releases the pressure of the pressing means. After the return, the position of the lever member is returned before the pressure is released. Therefore, by configuring the lever member with two cams, it is possible to achieve the effects of low cost and space saving.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The embodiments of the present invention will be described below.
This will be described with reference to the drawings.

(First Embodiment) As shown in FIGS. 1 to 9, a fixing device of an image forming apparatus according to the first embodiment includes a heating means 1 for heating a transfer material carrying a toner image.
And a pressurizing means 50 for press-contacting the transfer material with the heating means 1.
And an releasing unit 70 for releasing the pressure of the pressure unit 50, and an image forming apparatus for fixing the toner image on the transfer medium by passing the transfer material between the heating unit 1 and the pressure unit 50. In the fixing device 118, the one end of the releasing means 70 for releasing the pressure of the pressure applying means 50 when removing the paper, that is, sometimes the paper is used as a fulcrum, and after removing the jammed paper, the pressure applying means 50 is removed. Of the cover member 11 that swings, the swinging member including the protruding portion 18 protruding from a part of the swinging member that constitutes the returning means 180 that returns the pressure of the swinging member to the position before releasing the pressure. It is composed of a lever member 7 which is engaged at one end, and is provided with two cams 17 and 18 projecting toward the pressurizing means at different positions. One cam 17 constitutes the releasing means 70, and after the pressure is restored. , Lever member 7
The other cam 18 that returns the pressure to the position before the release of pressure constitutes the return means 90.

The arrangement of each functional member as seen from the front of the machine in the image forming apparatus of the first embodiment is as shown in FIG. The optical system uses the ROS 101, and 102 represents the writing laser optical path.

Black developing / drum 1 above ROS 101
03, cyan color development, drum 104, magenta color development
The drum 105 and the yellow developing / drum 106 are respectively arranged. Immediately below the cover 121 at the top of the machine, a black toner cartridge 107, a cyan toner cartridge 108, a magenta toner cartridge 109, and a yellow toner cartridge 110 are arranged.

First BTRs 111 are respectively arranged at positions facing (opposing) the developing and drums of the respective colors, with the intermediate transfer belt 113 interposed therebetween.
Second BTR on the left side of 13 so that it touches the belt
There is 112. There is a fixing device 118 above the second BTR 112 and in the upper left of the machine.

The paper 115 is stored in a paper feed tray 114, and is fed one by a feed roll 116, sent to a transfer unit by a transport roll 117, transferred by a second BTR 112, and fixed and discharged by a fixing device 118. Roll 119
Is discharged to the outside of the machine. This is represented by the paper path 120.

When a paper jam occurs in the fixing device 118,
The user opens and closes the left cover 122 by hand. At this time, the left side cover 122 rotates counterclockwise (method) about the left side cover opening / closing fulcrum 124 and stops at the position of the left side cover open state 123. After the paper is removed, the user manually returns the left cover from the position of the open state 123 to the closed state of the left cover 122.

As shown in FIG. 1, the fixing device 118 according to the first embodiment of the present invention, which is in a pressed state during copying or standby, includes a heat roll 1 and a pressure belt 2, a bracket 3 and a bracket 4, and a fulcrum. It is composed of a spring 5 and a screw 6 on both sides of the screw 16.

In this state, the NIP release lever 7 is in the free state position of 13. The NIP release lever 7 rotates around a fulcrum 9 provided on the cover 8 of the fixing device, and a rotation locus 100.
Move up.

The machine cover 11 is provided with the NIP releasing lever 7 in the free position 13 so as to project vertically downward in FIG. 1 at regular intervals so as to realize a shape 14 for sandwiching the NIP releasing lever 7. Left and right engaging parts 141,
142 is provided. Engagement part 1 of machine cover 11
41 moves on the rotation locus 150 with the mounting portion 12 of the machine cover 11 as a fulcrum.

As shown in FIG. 2, the NIP releasing lever 7 includes a cam 17 which constitutes a releasing means for releasing the pressurized state, and a returning means for returning to the free state position after returning to the pressurized state. Is provided.

In the fixing device of the first embodiment having the above-mentioned structure, when a paper jam occurs in the fixing portion, the machine cover 11 is opened as shown in FIG. At this time, since the right engaging portion 141 of the machine cover 11 moves counterclockwise on the rotation locus 150, the NIP release lever 7
The NIP release lever 7 is caught by the tip of the fixing device, and the NIP release lever 7 is provided on the cover 8 of the fixing device.
Move 0 counterclockwise.

At this time, the cam 17 of the NIP release lever 7
However, since it rotates counterclockwise around the fulcrum of the bracket 4, it is pressurized by the spring 5 and the screw 6.
The pressure applied to the heat roll 1 and the pressure belt 2 is released. When the machine cover 11 is completely opened as shown in FIG.
The cam 17 of the release lever 7 further pushes the bracket 4, and at the position 190 where the rotation loci 100 and 150 intersect,
The machine cover 11 receives no force from the fixing device.

The NIP release lever 7 pushes the bracket 4, but at a position 190 where the rotation loci 100 and 150 intersect.
Then, it leaves the machine cover 11. In this state, the shape of the cam 17 is unstable, so that the shape of the cam is stable.
Return to the position of the NIP release lever 7 shown in.

When the paper, that is, the removal, is completed, the machine cover 11 is closed as shown in FIG.
The NIP release lever 7 is pushed by the engaging portion 141 on the right side of the to return to the pressurized state. When the machine cover 11 is completely closed, the NIP release lever 7 must return to the free state 13 shown in FIG. 1 to release the pressure when the next sheet of paper is removed.

Therefore, as shown in FIG. 7, when the NIP release lever 7 is rotated clockwise from the position 130 shown by the solid line in the free state, the right side engaging portion 141 of the machine cover 11 causes Push the NIP release lever 7 clockwise. Then, the cam 18 of the NIP release lever 7
Is rotated clockwise about the fulcrum 16 of the bracket 3.

The NIP release lever at this time is 220-2.
The position is indicated by the dashed line. Since the reaction force of the spring 5 is generated in the NIP release lever 7 via the bracket 3, a counterclockwise rotational force is generated. Rotation loci 100 and 1
When the machine cover 11 passes the point 210 at which 50 intersects, the NIP release lever 7 returns to the free position 130 indicated by the solid line due to the counterclockwise rotational force.

As shown in FIG. 8, when paper, that is, when no paper is generated, when the machine cover 11 is opened, the pressure is released, but a point 19 where the rotation loci 100 and 150 intersect.
By the time it reaches the position where it passes 0, the machine cover 11
When the machine is closed, the engaging portion 1 on the left side of the machine cover 11
The NIP release lever 7 is pushed by 42 to return to the pressurized state.

In the fixing device of the image forming apparatus of the first embodiment having the above-described operation, the NIP releasing lever as a swinging member having one end constituting the releasing means 70 as a fulcrum when removing the paper, that is, the paper is removed. 7, the pressing means 50
As the swinging member which constitutes a returning means for releasing the pressurization of the spring 5, removing the jammed paper and returning the pressurization, and returning the position of the NIP release lever 7 to before the pressure release.
After the pressure of the pressure-applying means 50 is released by the protrusion 18 which is made to protrude to a part of the IP release lever 7, the NIP is released.
Since the position of the release lever 7 is returned before the pressure is released and the return means 180 for the next release of the pressure is configured by the NIP release lever 7 as the swing member which is one member, the cost is reduced. This has the effect of realizing space saving.

In the fixing device of the image forming apparatus of the first embodiment, the NIP release lever 7 as a lever member that engages with one end of the swinging cover member that constitutes the swinging member.
After releasing the pressure of the pressure applying means 50 by the one cam 17 constituting the releasing means 70 of the two cams 17, 18 protruding toward the pressure applying means 50 at different positions in , The other cam 18 constituting the return means 180 for returning to the position before the pressure release is the pressure means 5
After the pressure is returned to 0, the position of the NIP release lever 7 is returned to the state before the release of the pressure to prepare for the next release of the pressure. The NIP release lever 2 is one lever member provided with two cams.
Since it is configured by 0, there is an effect of realizing low cost and space saving.

(Second Embodiment) As shown in FIG. 10, the fixing device of the image forming apparatus according to the second embodiment has the first and second positions when the NIP release lever 7 and the cams 17, 18 are shaped and arranged. Differences from the embodiment are the main differences, and the differences will be mainly described below.

FIG. 10 shows the fixing unit 1 in the second embodiment.
18 shows a sectional view of 18. Bracket B and bracket H are
It is attached to fulcrum A. The center of the belt B is located at the position (X, Y) = (-16, 17) from the fulcrum A, and the outer diameter is Φ30 mm. The center of the heat roll C is located at the position (X, Y) = (10, 23) from the fulcrum A, and the outer diameter is Φ26 mm.

The rotation fulcrum D of the NIP release lever 7 is located at a position (X, Y) = (11.5, 70) from the fulcrum A.
The surface of the bracket B with which the cam of the NIP release lever 7 contacts is at a position connecting the points B1 and B2. Regarding the coordinates from the fulcrum A, B1 is (X, Y) = (5, 88), and B2 is (X, Y) = (2, 63). The amount of bite between the belt B and the heat roll C is 1.5 mm.

In this state, the relationship between the cams 17 and 18 of the NIP release lever 7 and the surface of the bracket B at the position connecting the points B1 and B2 is shown in the diagram of FIG. . The graph shows how the NIP release lever 7 is rotated and the cams 17 and 18 of the NIP release lever interfere with each other assuming that the cam contact surface of the bracket B does not move.

The rotation angle of 0 degrees of the NIP release lever 7 is the initial position of the cam, which is the position during the printing operation. The cam 18 of the NIP release lever 7 is in contact with the cam contact surface of the bracket B.

Paper clogging occurs and the NI is removed to remove the paper.
Since the NIP release lever 7 is rotated to release P, the interference amount of the cam 17 increases from 15 degrees to 53 degrees. The NIP cancellation operation range is from 15 degrees to 53 degrees. The amount of interference is 0 mm from 0 degree to 15 degrees because there is a gap until the cam 17 contacts the cam contact surface of the bracket B.

From 53 degrees to 73 degrees, the NIP release lever 7 comes out of the hooking part of the left cover of the machine,
This is the range to return to the IP release position. The interference amount from 53 degrees to 73 degrees is increased as compared with the interference amount from 15 degrees to 53 degrees. This is the cam position when NIP is released.
After contacting the cam contact surface of the bracket B on the surfaces 171 and 172 of No. 7, 1 of the cam 17 having a distance from the fulcrum of rotation.
This is because the surface 72 contacts the cam contact surface of the bracket B.

When the paper, that is, the removal is completed, the machine left side cover is closed. Then, the hook portion of the machine left side cover pushes the NIP release lever 7 located at the 53 degree position in the graph to restore the NIP. The NIP release lever 7
It is pushed by the hook on the left side cover of the machine, rotates to -13 degrees, and then returns to the initial position of 0 degrees. By rotating it to -13 degrees, the reaction force that returns to the initial position of 0 degrees is obtained.

In the fixing device of the image forming apparatus of the second embodiment having the above-described structure and operation, the releasing means 70 and the returning means 180 are constituted by the NIP releasing lever 7 having the cams 17 and 18, so that the number of parts is reduced. Less,
Since the function of releasing pressure and returning is realized, it is inexpensive and can save space in the device.

In the fixing device of the image forming apparatus of the second embodiment, the shape of the NIP release lever 7 and the cams 17, 1 are used.
The shape and arrangement position of 8 are modified to realize the rotation angle of the NIP release lever 7 and the amount of cam interference shown in FIG. 11, thereby achieving a predetermined release operation and return operation.

The embodiments described above are merely examples for explanation, and the present invention is not limited to them. Those skilled in the art will recognize from the claims, the detailed description of the invention and the description of the drawings. Modifications and additions can be made without departing from the technical idea of the present invention.

[Brief description of drawings]

FIG. 1 is a side view illustrating a fixing device of an image forming apparatus according to a first exemplary embodiment of the present invention.

FIG. 2 is a side view showing an NIP release lever, a release cam, and a return cam in the fixing device of the first embodiment.

FIG. 3 is a side view showing a state in which the machine cover of the fixing device of the first exemplary embodiment is slightly opened.

FIG. 4 is a side view showing a state in which a machine cover of the fixing device according to the first exemplary embodiment is completely opened.

FIG. 5 is a side view showing a state where the NIP release lever in the fixing device of the first embodiment has returned to a stable state.

FIG. 6 is a side view showing a state in which the machine cover of the fixing device according to the first embodiment has begun to be closed.

FIG. 7 is a side view showing a returning state by the NIP release lever and the returning cam in the fixing device of the first embodiment.

FIG. 8 is a side view showing a pressure released state in the fixing device of the first embodiment.

FIG. 9 is a side view showing the image forming apparatus of the first embodiment.

FIG. 10 is a side view illustrating a fixing device of an image forming apparatus according to a second exemplary embodiment of the present invention.

FIG. 11 is a diagram showing a relationship between a rotation angle of a NIP release lever 7 and a cam interference amount in the fixing device of the second embodiment.

FIG. 12 is a perspective view showing a fixing device of a conventional image forming apparatus.

[Explanation of symbols]

1 heating means 7 Lever member 17, 18 cam 50 Pressurizing means 70 Release means 118 fixing device 180 Recovery means

Claims (2)

[Claims] 1. A heating means for heating a transfer material carrying a toner image, a pressurizing means for press-contacting the transfer material to the heating means, and a releasing means for releasing the pressurization of the pressurizing means. In a fixing device of an image forming apparatus for fixing the toner image on the transfer material by passing the transfer material between the heating means and the pressure means, when the paper, that is, the paper is removed, the pressure means is applied. The releasing means for releasing the pressure is constituted by a swinging member having one end as a fulcrum, and after removing the jammed paper, the pressure of the pressing means is restored,
A fixing device for an image forming apparatus, wherein a returning means for returning the position of the swinging member before releasing the pressure is constituted by a projecting portion projecting to a part of the swinging member. 2. The rocking member according to claim 1, wherein the rocking member includes a lever member that engages with one end of a rocking cover member, and includes two cams that project toward the pressing means at different positions. A fixing device for an image forming apparatus, wherein one cam constitutes the releasing means, and the other cam constitutes returning means for returning the position of the lever member to the position before releasing the pressure after returning to the pressure.