JPH063400Y2 - Fixing device - Google Patents

Description

[Detailed description of the device] [Industrial applications]

The present invention relates to a fixing device that heats and fixes an unfixed toner image on a transfer material such as recording paper, and fixes the unfixed toner image by conveying the transfer material by sandwiching it between a heating roller and a pressure roller that rotate in pressure contact with each other. The present invention relates to a fixing device applied to an image forming apparatus such as an electrophotographic recording device, a laser recording device, and a facsimile.

[Background of device]

In an image forming apparatus such as an electrophotographic recording apparatus, a method of fixing a toner image which is an unfixed image on a transfer material such as recording paper includes, for example, a solvent fixing method, a pressure fixing method, a heat fixing method, Generally, a toner is melted by a heating roller and adhered onto a transfer material, and a heat fixing method is often adopted. In this type of system, a transfer material supporting a toner image, which is an unfixed image, is conveyed by being sandwiched between a heating roller having a heat source such as a heater that rotates in pressure contact with each other and a pressure roller in pressure contact with the heat roller. The toner is melted by the pressure and heat of the heating roller to be thermally fixed on the transfer material. In a general heating roller type fixing device, the heating roller is located on the upper side. The heating roller has a heating means such as a heater inside a pipe-shaped metal roller. The pressure roller that comes into pressure contact with the heating roller is formed by winding, for example, silicon rubber around the peripheral surface of the core metal. The surface temperature of the heating roller is maintained at around 200 ° C. by the heating means, and is rotated in one direction by power. On the other hand, the pressure roller is pressed against the heating roller from behind the transfer material while the transfer material is fixed, and is driven to rotate. While the transfer material passes through the fixing device, the toner image is fused and fixed, and then discharged to the outside.

[Problems to be solved by the device]

Toner on the transfer material may be transferred and adhere to the surface of the heating roller. This is generally referred to as offset development, but toner adhesion to the heating roller due to this offset phenomenon transfers to the transfer material during the next fixing operation and stains the transfer material. A cleaning roller is provided to clean the surface of the heating roller.
The cleaning roller is formed of foamed silicone rubber or the like, and is provided in contact with the surface of the heating roller on the downstream side in the rotation direction of the heating roller from the pressure contact position between the heating roller and the pressure roller. The cleaning roller is more easily damaged than other members and is frequently replaced. In the conventional fixing device, the entire device must be disassembled when the cleaning roller is replaced, and thus it is difficult for a general user to perform the replacement work.

[Means for solving problems]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points and has been made to solve the drawbacks. A cleaning roller unit is configured to be rotatable and openable in a fixing device casing, and the cleaning roller can be replaced without disassembling the fixing device. The purpose is to provide a fixing device that can be easily performed. The above-mentioned purpose is to convey the transfer material on which the unfixed toner image is transferred between the heating roller 1 and the pressure roller 2 which rotate in pressure contact with each other to fix the unfixed toner image, and to pass through the rear guide portion 6. In the fixing device in which the transfer material is discharged,
A cleaning roller 8 that rotates in contact with the heating roller 1 on the downstream side in the rotation direction of the heating roller 1 from the pressure contact position between the heating roller 1 and the pressure roller 2, and a rotation shaft of the cleaning roller 8 A cleaning roller unit 20 including a bearing member 22 that supports the cleaning roller and a cleaning roller mounting plate 21 that fixes the bearing member 22 is provided, and the cleaning roller mounting plate 21 is hinged to a casing 23 of the fixing device. A fixing device is characterized in that the unit 20 is rotatably opened and closed with respect to the casing 23 of the fixing device, and the cleaning roller 8 is put in and out through an opening 23c of the casing 23 of the fixing device. To be achieved.

【Example】

One embodiment of the present invention is shown in FIGS. 1, 2a and 2b. FIG. 1 shows the structure of the fixing device of the present invention.
The heating roller 1 is forcibly driven and rotated clockwise at a fixed position by a power unit (not shown) on the main body side of the image forming apparatus. The pressure roller 2 is pressed against the heating roller 1 and is driven to rotate counterclockwise. The transfer material having the toner image transferred on the upper surface is conveyed in the direction of the arrow A through the guide of the front guide plate 3 toward the pressure contact portion of both rollers. The transfer material is nipped by both rollers and conveyed to the left in the figure. At this time, the toner image on the transfer material is
The heat generated by the heater 4 built in the heating roller 1 is melted and fixed on the transfer material. The transfer material on which the toner image has been fixed is carried out from the pressure contact portion of both rollers, and after the toner image has been cooled and fixed, it is separated from the roller surface by the separating claw 5 and guided by the rear guide member 6 in the direction of arrow B. From the fixing device casing to the outside. The heating roller 1 is a pipe-shaped metal roller having an outer diameter of about 22 mm. The pressure roller 2 is a roller having an outer diameter of about 22 mm in which a silicon rubber layer having a thickness of 6.5 mm and a hardness of about 40 ° is formed on the outside of a core metal. The heater 4 built in the heating roller 1 is
It has almost the same length as. The amount of heat generated is determined by the contact type temperature sensor 7 set on the peripheral surface of the heating roller 1.
The peripheral surface temperature of the heating roller 1 is always 20
It is controlled so that it is kept around 0 ℃. The cleaning roller 8 is attached to the heating roller 1 so that dust such as toner and paper dust attached to the peripheral surface of the heating roller 1 does not transfer to a new transfer material and contaminate the toner image.
And abutted against each other. The cleaning roller 8 is installed so as to come into contact with the vicinity of the uppermost end of the heating roller 1. The cleaning roller 8 is a roller made of foamed silicone rubber and is pressed against the peripheral surface of the heating roller 1 without being impregnated with oil or the like, and is driven to rotate to adsorb and remove the adhered toner and the like. FIG. 2a and FIG. 2b are partial side views of the fixing device casing showing an operating state of rotating and opening and closing the cleaning roller unit. In these drawings, 20 is a cleaning roller unit, 21 is a cleaning roller mounting plate, 22 is a bearing member, and 23 is a bearing member.
Is a fixing device casing. The same members as those in FIG. 1 are designated by the same reference numerals. The fixing device according to the present invention includes a cleaning roller mounting plate 21.
The cleaning roller unit 20 having the cleaning roller 8 supported therein is provided in a casing 23 of the fixing device so as to be rotatable and openable. The cleaning roller mounting plate 21 is made of a flocked steel plate in which flocking is applied to an iron plate having a thickness of 1 mm. A hinge hole 21a is formed in each of the curved surfaces of the cleaning roller mounting plate 21 on both sides. Further, bearing members 22 to be described later are fixed to inside of both ends of the cleaning roller mounting plate 21. The bearing member 22 is a sliding bearing made of a synthetic resin having a low coefficient of friction and increased rigidity. The rotation shaft support portion of the bearing member 22 has an opening on the side thereof having a length equal to the rotation shaft diameter of the cleaning roller 8. By passing the opening portion through the rotation shaft of the cleaning roller 8, the bearing The member 22 and the cleaning roller 8 can be attached and detached. The fixing device casing 23 is made of an iron plate having a thickness of 1.2 mm, and has an opening hole 23c on the upper surface for inserting and removing the cleaning roller 8. Positioning members 23a are fixed to both ends of the fixing device casing 23, and hinge pins 23b which are loosely inserted into the hinge holes 21a of the cleaning roller mounting plate 21 are planted in the positioning members 23a. When the hinge pin 23b is inserted into the hinge hole 21a, the cleaning roller mounting plate 21 can be rotated around the hinge pin 23b. If the cleaning roller 8 becomes soiled and it becomes necessary to replace the cleaning roller 8, the cleaning roller mounting plate 21
Is rotated in the direction of arrow C. The cleaning roller unit 20 having a structure in which the cleaning roller 8 is rotatably supported by the cleaning roller mounting plate 21 is rotated and opened with respect to the fixing device casing 23 to be in the state shown in FIG. 2b. In this state, the cleaning roller 8 is taken out and a new cleaning roller is attached. Then, the cleaning roller mounting plate 21 is rotated around the hinge pin 23b in the direction opposite to the direction when the cleaning pin is opened to restore the original state.

[Effect of device]

According to the present invention, the cleaning roller unit having the structure in which the cleaning roller is supported by the cleaning roller mounting plate is configured so as to be rotatable and openable and closable with respect to the fixing device casing, so that the cleaning roller can be easily replaced. It is possible to provide a fixing device that does not contaminate the surroundings because it is possible to replace the cleaning roller without opening the inside of the fixing device and only by moving the cleaning roller in and out through the upper opening.

[Brief description of drawings]

FIG. 1 is a sectional view of a fixing device showing an embodiment of the present invention.
FIG. 2a and FIG. 2b are partial side views of the fixing device casing showing the state of the rotary opening / closing operation of the cleaning roller unit. DESCRIPTION OF SYMBOLS 1 ... Heating roller, 2 ... Pressure roller 8 ... Cleaning roller, 20 ... Cleaning roller unit 21 ... Cleaning roller mounting plate, 21a ... Hinge hole 22 ... Bearing member, 23 ... Fixing device casing 23a ... Positioning member, 23b ... Hinge pin

Claims (2)

[Scope of utility model registration request] 1. A transfer material on which an unfixed toner image is transferred is conveyed between a heating roller 1 and a pressure roller 2 which rotate in pressure contact with each other to fix the unfixed toner image, and a rear guide member 6 is formed. In a fixing device in which the transfer material is ejected through, a cleaning roller that rotates in contact with the heating roller 1 on the downstream side in the rotation direction of the heating roller 1 from the pressure contact position between the heating roller 1 and the pressure roller 2. 8, a bearing member 22 that rotatably supports the rotation shaft of the cleaning roller 8, and a cleaning roller mounting plate 21 that secures the bearing member 22 are provided, and the cleaning roller mounting plate 21 is fixed to the fixing roller unit 20. The cleaning roller unit 20 is hingedly connected to a casing 23 of the apparatus, and the cleaning roller unit 20 is rotatably and openably operated with respect to the casing 23 of the fixing device. Fixing apparatus characterized by the opening hole 23c of pacing 23 was configured to and out of the cleaning roller 8. 2. A bearing member 22 of the cleaning unit 20 when the cleaning roller unit 20 is opened.
The fixing device according to claim 1, wherein the cleaning roller 8 can be removed from the utility model registration.