JP3220643B2 - Jam handling mechanism of fixing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a jam processing mechanism of a fixing device provided in an image forming apparatus such as an electrophotographic copying machine, a printer, a facsimile, and the like.

[0002]

2. Description of the Related Art A fixing device provided in an image forming apparatus includes:
Usually, it has a heating roller and a pressure roller, and heats the sheet on which the image has been transferred by the photosensitive drum or the like under pressure to fix the transferred image on the sheet. In many cases, it can be loaded and unloaded.

[0003] In such heat fixing under pressure, the paper after transfer may be wound around the heat roller and a jam may occur. In such a case, the fixing device is often configured to be openable in order to easily perform the jam processing. There are the following types of methods for opening the inside.

[0004] Both the guide plate and the peeling claw for preventing winding are moved in parallel in the discharge direction by a guide mechanism such as a guide rail. The guide plate and the peeling claw are moved in parallel in the discharge direction using the link mechanism. The guide plate and the peeling claw are rotationally moved upward in the discharging direction. Only the guide plate is rotated downward in the discharge direction.

[0005]

The problems of the above-mentioned conventional systems are as follows. A relatively large moving amount is required to perform a jam clearance by inserting a hand between the moving unit and the main body, and the apparatus is increased in size to obtain the moving amount. The link mechanism itself is complicated,
The number of parts increases and the cost increases. A mechanism for holding the rotating unit at the top is separately required, and the visibility of the heating roller is low, and the workability of the jam clearance is not good. In a state where the peeling claw is left, the paper wound around the heating roller is hardly peeled off, and the workability of the jam processing is not good.

The present invention has been made in view of such circumstances,
It is an object of the present invention to provide a fixing device capable of performing a jam removal operation with a simple configuration with good workability.

[0007]

According to the present invention, means for solving the above-mentioned problems are constituted as follows. That is, a guide plate that supports a peeling claw for preventing paper wrapping from being pressed against the heating roller from below is supported by a guide holder rotatably supported by the apparatus main body.
A jam processing mechanism of a fixing device that is supported and configured to be able to separate the peeling claw from a heating roller during jam processing , wherein a guide groove is formed in the guide plate, The guide shaft provided in the apparatus main body is loosely fitted in the guide groove, and the guide is moved so that the initial trajectory of the guide plate for separating the peeling claw from the heating roller is slightly lower than the trajectory of the guide holder. A groove is formed obliquely downward in the direction in which the groove is turned and the separation claw is moved downward at an initial stage of separating the separation claw from the heating roller.

When the guide plate is turned (opened), the guide groove of the guide plate moves along the guide shaft fixed to the apparatus main body, so that the peeling claw is forcibly moved downward. Since the roller is separated from the roller, it is possible to prevent the occurrence of troubles such as flaws on the roller surface. Further, due to the downward movement of the peeling claw, the paper wound around the heating roller is easily peeled, and the jam processing is facilitated.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a fixing device according to an embodiment of the present invention; FIG. 1 is an explanatory view of a main part configuration of a jam processing mechanism of a unit-type fixing device. FIG. 5 is a cross-sectional view of the fixing device. In these drawings, reference numeral 1 denotes a heating roller, and 2 denotes a detachable heating roller. 3 is a bearing (bearing member) attached to both ends of the heating roller 1, 4 is a pressure roller, 5 is a lower housing supporting the pressure roller 4, and 6 is an upper housing 2. Is a pivot that supports the robot freely to rotate.

The heating roller 1 is supported by a guide plate 8 in a state where a plurality of peeling claws 7,... For preventing the paper from being wound after the transfer is urged from below (see FIG. 2). The guide plate 8 is supported on a guide holder 10 by a pivot 9, and the guide holder 10 is pivotally supported by the lower housing (apparatus body) 5 by a pivot 11. When a jam occurs, for example, The guide holder 10 can be opened in an upwardly open state as shown in FIG.

The above-mentioned peeling claw 7 is rotatably supported at its upper part by a support shaft 71 provided on a guide plate 8, and a spring 12 is stretched over its upper end. It is urged in the contacting direction, and rotation (clockwise rotation in the figure) is regulated at a predetermined position by a stopper (not shown) (see FIG. 3).

On the other hand, a guide plate 8 for supporting the peeling claws 7,.
A guide groove 81 directed obliquely downward is formed on the swinging end side of the, and a guide shaft 13 fixed to the upper housing (apparatus main body) 2 is loosely fitted in the guide groove 81. When the guide holder 10 is closed (indicated by a two-dot chain line in FIG. 1), the tips of the peeling claws 7 urge the heating roller 1 from below.
When the roller 0 is rolled open, the tips of the peeling claws 7,... Are separated from the heating roller 1 while moving downward at the initial stage (see FIG. 3).

When the guide holder 10 is further opened (see FIG. 4), the lower end of the flange 82 formed at the swinging end of the guide plate 8 abuts on the latching lip 101 of the guide holder 10, and the guide plate is moved. The rotation (clockwise rotation in the figure) of the 8 is regulated together with the peeling claw 7, and is rotated together with the guide holder 10 to the state of FIG.

When the guide holder 10 is turned, the guide grooves 81 of the guide plate 8 move along the fixed guide shaft 13 so that the guide plates 8 are forcibly moved. The guide groove 81 is inclined obliquely in the turning opening direction so that the initial trajectory of the guide plate 8 is slightly lower than the trajectory of the guide holder 10. This is due to being formed downward. When turning the guide holder 10 in the closing direction, the peeling claws 7,.
Is close to the heating roller 1 and moves upward and downward from below to contact the roller surface.

The downward movement of the peeling claws 7,... At the initial stage of the rotation opening makes it possible to prevent the roller surface of the heating roller 1 from being flawed, and to prevent the transfer of the transferred toner adhered to the roller surface. Is pushed down by the peeling claws 7,..., So that the paper is easily peeled off, and the jam clearing work becomes easy.

FIG. 5 shows a cross section of such a unit-type fixing device. The heating roller 1 is provided with two halogen heaters 21 and 21, and the upper portion thereof removes toner stains adhered to the roller surface. Is provided in a biased state along the roller surface, and the peeling claws 7,.
Below, a peeling claw 23 for the pressure roller 4 is provided on the guide holder 10. Explaining another configuration, reference numeral 24 denotes a pressing plate for fixing the bearing 3 of the heating roller 1 in a state of being fitted into the mounting recess 20 of the upper housing 2, and a pressing plate 24 inside the elongated hole 241 formed in the upper housing 2. Is detachably fixed to the upper housing 2 by a fastening member 242 such as a bolt loosely fitted to the upper housing 2.

Reference numeral 25 denotes a support member for pivotally supporting the support shaft 41 of the pressure roller 4, reference numeral 26 denotes the pivot, reference numeral 27 denotes a spring for urging the support member 25 upward, and reference numeral 28 denotes the spring 27.
Adjusting shaft for adjusting the tension of the nut, 29 and 30 are nuts,
31 is an E-ring for retaining.

[0018]

As described above, according to the jam processing mechanism of the fixing device of the present invention, when the guide plate is turned (opened) during jam processing or the like, the peeling claw is moved downward, and the roller surface is damaged. Can prevent the occurrence of troubles such as
In addition, the downward movement of the peeling claw facilitates peeling of the transferred paper wound around the roller surface, thereby facilitating the jam clearing operation. Particularly in the present invention, a guide holder,
The above-mentioned excellent effects are exhibited with extremely few parts such as the guide plate, the guide groove, and the guide shaft, and the structure can be simplified and compact. Therefore also
There is an advantage that it can be provided at a low price.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a main configuration of a jam processing mechanism of a fixing device of the present invention.

FIG. 2 is an explanatory diagram showing a correspondence relationship between a peeling claw and a heating roller in a state where the guide holder is closed.

FIG. 3 is an explanatory view showing an initial state in which the guide holder is slightly opened.

FIG. 4 is an explanatory view showing a state where the guide holder is further opened.

FIG. 5 is a vertical sectional view showing a configuration of the identification attachment device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Heating roller, 2, 5 ... Device main body, 7 ... Peeling claw, 8 ...
Guide plate, 10: guide holder, 81: guide groove, 13
... guide shaft.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masaya Murata 1-2-28 Tamazo, Chuo-ku, Osaka City, Osaka Prefecture Inside Mita Kogyo Co., Ltd. ) Surveyed field (Int.Cl. ⁷ , DB name) G03G 13/20 G03G 15/00 510-550 G03G 15/20

Claims (1)

(57) [Claims] 1. A guide plate for supporting in a state of being urged from below the peeling claw for preventing the winding of the paper against the heating roller, is rotatably supported on the apparatus main assembly guide
A jam processing mechanism of a fixing device supported by a holder and configured to be able to separate the peeling claw from a heating roller during jam processing , wherein a guide groove is formed in the guide plate. Along with this, the guide shaft provided in the apparatus main body is loosely fitted in the guide groove, so that the trajectory of the initial guide plate for separating the peeling claw from the heating roller is slightly lower than the trajectory of the guide holder,
The jam of the fixing device, wherein the guide groove is formed obliquely downward in the turning opening direction, and the tip of the separation claw is moved downward at an initial stage of separating the separation claw from the heating roller. Processing mechanism.