JPH028302Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a fixing device in an image forming apparatus such as a copying machine or a facsimile machine, and more particularly to a fixing device that performs fixing using a pair of rollers.

Prior Art For complex jam paper removal processing or maintenance (parts replacement, cleaning), the fixing device is removed from the machine body to facilitate jam paper removal and maintenance.
(see Japanese Patent Publication No. 2003-111100), attempts have been made to remove jam paper or to facilitate maintenance. In these devices, the support means for the fixing roller and the support means for the pressure roller are provided separately, but a method for directly positioning the fixing roller and the pressure roller is to provide support means for the respective support means. This is done using bearings, etc.

For this reason, not only are multiple bearings required, but the accuracy of the axes between the fixing and pressure rollers is affected by the assembly accuracy of each support means, and not only is this adjustment complicated, but also special Providing an adjustment means would further increase the number of parts.

Purpose The present invention was created in view of the drawbacks of the above-mentioned conventional technology, and by providing separate and independent support members for the fixing and pressure rollers in the fixing device, it is easy to remove jam paper, etc. It is an object of the present invention to provide a fixing device that is easy to maintain and easy to maintain, and also allows easy position adjustment between fixing and pressure rollers.

Configuration The configuration of the present invention will be described below based on examples. FIG. 1 is an overall schematic diagram of a fixing device when the present invention is applied to a copying machine of a type in which the entire fixing device can be exposed by sliding the entire fixing device from the copying machine main body.

The transfer paper carrying the unfixed toner image is guided by the entrance guide plate 1 to the nip portion 4 of the heat fixing roller 2 and the pressure roller 3, and as it passes between both rollers, it is fixed by applying heat and pressure. Ru. The fused transfer paper is transferred between the transport roller pair 5, 5', the driving reversing roller 6 and the driven reversing roller 7, 7', and the paper ejection roller pair 8,
8' and is discharged outside the machine. During double-sided copying, back-side copying, and reverse paper ejection, the upper reversing rollers 7 and 7' are opened and the transfer paper is sent to the upper part once, and the transfer paper is sent according to each mode. (Detailed explanation will be omitted since it is not directly related to the present invention.) The fixing device is composed of the following five units. The first is a main body unit A having a pressure arm 9 and a pressure roller 3; 3 is a driven reversing roller pair 7,
7' Reversing unit C having a reversing mechanism, the fourth is a left cover 13, a cleaning blade 14, an oil application felt 15, a metering blade 16,
Oil application unit D having an oil sump 17, the fifth is a heat insulating material 18, a cover 19, a separating claw 20
This is a heat insulating cover unit E having the following.

Each unit will be explained below. The main body unit A includes a pair of side plates 40a and 40b (hereinafter referred to as a first side plate pair) fixedly held on a rail member that slidably supports the entire fixing device from the copying machine main body.
A pressure arm 9, a pressure roller 3, a lower fixing conveyance roller 5', a drive reversing roller 6, and a pair of paper discharge rollers 7,
7' and so on. The pressure arm 9 has one end rotatably supported by the side plates 40a and 40b, and the other end supported by the pressure cam 21. A recess 22 is formed in the pressure arm 9, and the shaft portion of the pressure roller 3 is placed here. Further, since the pressure roller 3 is only placed on the pressure arm 9, it can be easily removed upward when other units are removed. Here, only the upper front side of the drawing has been described, but similar pressure arms and pressure cams are provided on the upper back side of the drawing, and both pressure cams are accurately fixedly supported on the same shaft. Therefore, the rotation of the shaft causes the pressure arm to swing via the pressure cam, and the pressure roller 3 can move up and down.

Next, the fixing roller unit B will be explained using FIG. 2. A pair of side plates 41a, 41b having a spacing slightly narrower than the spacing between the first pair of side plates.
(hereinafter referred to as the second side plate pair), a fixing entrance guide plate 1;
It supports a fixing roller 2 having an internal heater and a temperature detecting means 11 on the surface of the fixing roller. The fixing roller 2 is connected to the second side plate 41a through a bearing.
41b, and rotates as a result of the pressure roller. A recess 23 is formed below the fixing roller bearing of the second side plates 41a, 41b. The recess 23
The width in the horizontal direction is set to be slightly larger than the shaft diameter of the pressure roller 3, and when the main body unit A and the fixing roller unit B are assembled, the shaft of the pressure roller 3 is set within the recess 23. Horizontal positioning is performed. Therefore, the second side plates 41a, 41b
If the position and horizontal width of the recess 23 are set accurately, the fixing roller 2 and the pressure roller 3 can be
Accurate positioning can be achieved by assembling units that support each shaft. The fixing roller unit B is attached to the main body unit A using the second side plate 4.
1a, 41b between the first side plates 40a, 40b, screw holes 24', 25' into screw holes 24, 25 of the main unit, and screw holes 26', 27' into screw holes 26, 25 of the main unit. 27 and fixed with screws. Therefore, the main body unit and the fixing roller unit are in contact only at a small part of the side plate where these four pairs of screw holes are provided, and the heat energy generated by the fixing roller 2 is transferred through the main unit to the copying machine main body side. The risk of running away is kept to a minimum. To further completely prevent heat leakage, a heat insulating piece may be inserted into the contact portion, or the connecting portion itself may be made of a heat insulating material.

Next, the oil application unit D will be explained.
The oil application unit D supports an oil sump 17, a cleaning blade 14, an oil application felt 15, and a metering blade 16 between a pair of side plates, and has a screw hole 28' and a positioning pin hole 29' provided in the back plate. align them with the screw holes 28 and positioning pins 29 on the fixing roller unit side, respectively, and fix them with screws. The same applies to the opposite side of FIG. 2, which is not explained.

Next, the heat insulating cover unit E will be explained.
The heat insulating cover holds a shaft 30 that supports a separation claw 20 having the function of separating the transfer paper from the pressure roller, and has a forked metal plate 31 which is an engaging member with the oil application unit D. By sandwiching the inclined metal plate 32 provided in the oil applicator unit between the two prongs of the bifurcated metal plate 31, one end of the fixing cover is engaged, and the entire fixing cover unit E is attached to the engaging portion. It can be freely swung around the center. On the other hand, the fixing cover unit is fixed by placing the shaft 30 on a curved portion 33 provided on the second side plate of the fixing roller unit B.

Next, the reversing unit C will be explained with reference to FIG. The reversing unit C supports a reversing mechanism including an upper fixing conveyance roller 5 and a pair of reversing rollers 7, 7' between a pair of side plates, and rotates around the support shaft of an upper paper ejection roller 8 provided on the main unit A side. One end is freely supported. Therefore, the entire reversing unit E can swing around the support portion.

As mentioned above, each unit is divided into its own side plates, so the fixing roller, pressure roller,
It is easy for service personnel to perform maintenance such as replacing consumables such as the cleaning blade and cleaning the cleaning roller and thermistor used for temperature detection, and it is also easy to remove jammed transfer paper. Further, since maintenance can be carried out by disassembling or opening only the parts that suit the purpose by swinging the unit, the time required for maintenance can be shortened.

Effects According to the present invention, by providing separate and independent means for supporting the fixing roller and the pressure roller, it is easy to remove jam paper, etc., and the positions of the fixing roller and the pressure roller can be easily and accurately adjusted. You can obtain a fixing device. Furthermore, when the second pair of side plates that support the fixing roller are removed, the pressure roller is no longer restricted in the horizontal direction and can move in the horizontal direction. Even when it is necessary to wrap the pressure roller in a heat insulating material such as a waste cloth and handle it, the pressure roller can be removed after being moved horizontally to a position where there are no obstructing parts or the like to make it easier to handle.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an embodiment of the present invention, and FIG. 2 is an exploded view of the fixing device shown in FIG. 2... Fixing roller, 3... Pressure roller, 8...
Pressure arm.

Claims (1)

[Claims for Utility Model Registration] Consisting of a fixing roller and a pressure roller that are supported so as to rotate with their circumferential surfaces pressed against each other, with rotating shafts provided parallel to each other, and supporting the pressure roller. In a fixing device in which a first pair of side plates and a second pair of side plates that support the fixing roller are configured separately and independently from each other, the second pair of side plates support the rotation shaft of the fixing roller from both sides, and A concave groove is formed to position the rotation axis of the pressure roller in the horizontal direction, and a pressure arm is provided on the first pair of side plates, and the pressure arm has a groove that positions the rotation axis of the pressure roller in the vertical direction. A recessed groove is formed so that the rotating shaft can be moved in the horizontal direction, and when the second pair of side plates is removed, the pressure roller can be moved in the horizontal direction. A fixing device characterized by: