JPH02234178A - Fixing device - Google Patents

Abstract

PURPOSE:To attain the exchanging work of a supply roller from a front side and to improve workability by forming the leading edge of a shaft on the inserting edge side of silicone oil supplying roller conically and forming a guiding face which guides the leading edge to a receiving hole provided on a bearing part. CONSTITUTION:The silicone oil supplying roller 69 is brought into press-contact with the bottom of a pressure roller 62 and the both ends of the supplying roller 69 are protrusively provided with the shafts 75 and 76. The tip leading edge of the shaft 76 is formed conically. The shaft 75 is pivotally supported on the bearing part 79 of a front side frame 78 and the shaft 76 is pivotally supported on the bearing 81 of a rear side frame 80. the receiving hole is provided on the central part of the bearing 81 of the rearside, and an oblique guiding face which guides the shaft of the supplying roller 69 toward the receiving hole 86 is formed on the front face. Thereby, the supplying roller 69 can be attached/detached to/from the front side and the workability can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a fixing device used in, for example, an electronic copying machine or a laser printer.

(Prior Art) In general, this type of fixing device has a heating roller and a pressure roller in pressure contact with the heating roller in its main body, and the image-transferred paper is passed between these heating and pressure rollers. , the image is melted and fixed as a permanent image.

By the way, the surface of the heating roller is coated with a material with good releasability, such as PFA, to prevent developer from remaining or offset, and the surface temperature is controlled to an appropriate temperature, but the releasability is further improved. To prevent this, a release agent such as silicone oil is usually applied to the heating roller and pressure roller using a supply roller to prevent stains on the roller surface and images.

The supply roller is attached between the main body frames via a bearing section.

The bearing section is attached to the elongated hole of the main body frame to pivotally support the shaft of the supply roller, and is biased by a spring to press the supply roller against either the pressure roller or the heating roller and press the supply roller against the silicone oil. It is designed to be supplied and applied.

Further, the shaft of the supply roller is positioned and held by a fixing member such as an E-ring.

In this way, the attached supply roller is a regularly replaced part and is replaced at regular intervals.

(Problem to be Solved by the Invention) Conventionally, however, when replacing the above-mentioned supply roller, it is necessary to attach and detach both springs and to remove at least one fixing member. Needless to say, if it cannot be removed, even if it can be removed, the side with the drive device has gears, etc., making replacement work extremely difficult.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an improved fixing device that does not involve complicated and difficult work when replacing the supply roller.

[Structure of the Invention] (Means for Solving Problems) In order to solve the above problems, the present invention provides a heating roller and a pressure roller that is in pressure contact with the heating roller in the main body of the device, and The supply roller includes a supply roller that is slidably inserted along the guide body, and the supply roller has shafts at both ends thereof, and these shafts are supported by the receiving holes of the bearing part and are urged by the urging member. In the fixing device which supplies silicone oil by being pressed against at least one of the heating roller and the pressure roller, the tip of the shaft on the insertion end side of the supply roller is formed into a conical shape, and this shaft is supported by a bearing. The bearing is characterized in that a guide surface is formed on the bearing portion to guide the tip end of the shaft to the receiving hole.

(Function) With the above means, the supply roller can be replaced from the front side, which is easier to work with, and the replacement work can be done by attaching and detaching only the biasing member on the front side. .

(Example) The present invention will be described below with reference to an example shown in the drawings.

Figure 2 shows the internal configuration of the entire device.
There is a charge inside. Exposure, development. Transfer, peeling, cleaning, static elimination.
Image forming process configuration means 2 such as fixing are built in, and a movable document placement table (hereinafter referred to as a platen glass) 3 on which a document is set is provided on the top surface of the apparatus body l.

Attached to the upper surface of the apparatus main body 1 is document holding means 4 for holding down the document set on the platen glass 3.

Further, on the right side of the apparatus main body 1, a paper feed cassette 10 containing sheets of paper such as plain paper to be supplied to the image forming process configuration means 2 is inserted. Also, on the left side of the device main body 1, there is a tray 1 for storing fixed paper.
2 is provided.

The image forming process configuration means 2 has the following configuration. That is, a drum-shaped photoreceptor 20 as an image carrier is arranged approximately in the center of the apparatus main body 1, and around this photoreceptor 20, along the rotation direction,
A charging device 21, an exposure section 22a of an exposure device 22, a developing device 23, a transfer device 25. Peeling device 26, cleaning device 27. Static eliminators 28 and the like are sequentially arranged.

Furthermore, the paper feed cassette 10 is provided in the apparatus main body 1.
Paper fed automatically from the paper feed tray 2 or manual feed tray 2
9, the paper is manually fed through the image transfer section 30 between the photoreceptor 20 and the transfer device 25, and then transferred to the main body 1 of the apparatus.
A paper transport path 31 leading to the tray 12 provided on the left side of the paper is formed.

A pair of registration rollers 32 is arranged on the upstream side of the image transfer section 30 of the paper conveyance path 31, and a fixing device 5f is arranged on the downstream side.
33 and a pair of paper discharge rollers 34 are arranged. Also,
A conveyor belt unit 35 is disposed between the peeling device 26 and the fixing device 33.

Further, a take-out roller 36 is provided near the mounting portion of the paper feed cassette 10 to take out sheets one by one.

Further, the exposure device 22 illuminates the back of the document set on the platen glass 3 provided on the top surface of the device main body 1 with an exposure lamp 41 as a light source surrounded by a reflector 40, and uses reflected light from the document. cellhoc lens 42
It is designed to lead to the photoreceptor 20 via.

Further, in FIG. 2, reference numeral 56 denotes a cooling fan disposed above the fixing device 33.

When copying an original, the original is set on the original placing table 3 and the copy button is turned on from this state. As a result, the exposure lamp 41 is turned on, the document mounting table 3 is moved, and the document is scanned with light. The reflected light from the original is imaged on the photosensitive drum 20 via the self-hock lens 42, forming an electrostatic latent image. This electrostatic latent image is developed by a developing device 23.

On the other hand, at this time, sheets are fed from the paper feed cassette 10, aligned by the registration rollers 32, and then sent to the image transfer section 30, where the image is transferred. The paper on which this image has been transferred is placed in a peel-off charger.
26, the image is peeled off from the photoreceptor 20 and sent to the fixing device 33 via the conveyor belt unit 35, where the image is fixed. Thereafter, this paper is discharged onto the paper discharge tray 12 via the paper discharge roller 34.

Next, the fixing device 33 will be described in detail.

The fixing device 33 is the third rI! As shown in J, a pressure roller 62 is rotatably provided in the main body 61, and a heating roller 63 is pressed against the upper part of the pressure roller 62. Heaters 62a and 63a of 250W and 900W are installed inside these pressure roller 62 and heating roller 63, respectively.
is built-in. A thermal fuse 64, a thermistor 65, a peeling claw 66, a sub-cleaning felt 67, and a cleaning felt 68 are arranged around the heating roller 63 in this order along the rotation direction thereof.

The temperature of the surface of the heating roller 63 is controlled by a thermistor 65 to an appropriate temperature, for example, 200''±5''.

On the other hand, a silicone oil supply roller 69 is pressed against the lower side of the pressure roller 62. The supply roller 6
9 has a cylindrical tube 70 as shown in FIG. 1, and silicone oil 71 is accommodated inside this cylindrical tube 70.

The cylindrical tube 70 is provided with a large number of through holes 72, and the peripheral surface of the cylindrical tube 70 is covered with an oil retaining layer 73.
It is covered with felt 74 via the . Furthermore, shafts 75 and 76 are protruded from both ends of the cylindrical tube 70, and the tip of one of the shafts 76 is conical.

As shown in FIG. 3, the supply roller 69 is provided slidably along a guide 77, and its shaft
As shown in FIG. 4, 5 is rotatably supported by a bearing 79 of a front frame 78 of the main body 61, and the shaft 76 is rotatably supported by a bearing 81 of a rear frame 80. The bearing portion 79
．． 81 is a long hole 84 bored in the frame 78.80.
, 85 and is slidably attached to the spring 82,
83, so that the supply roller 69 is brought into pressure contact with the pressure roller 62.

By the way, the rear side bearing portion 81 is shown in FIGS. 5 and 6.
As shown in the figure, it has a receiving hole 86 at its center, and an inclined guide surface 87 for guiding the shaft 76 of the supply roller 69 to the receiving hole 86 is formed on the front surface.

Further, the tip portion 76 of the shaft 76 of the supply roller 69
As shown in 1rI4, the tip 76a is formed into a conical shape, and the tip 76a is guided into the receiving hole 86 along the guide surface 87 of the bearing 81.

Therefore, when replacing the supply roller 69, the front spring 82 is first removed, the frame 78 is removed, and the bearing portion 79 is removed from the shaft 75.

Thereafter, the supply roller 69 is pulled out to the front side along the guide 77. As a result, the shaft 7 on the rear side
6 comes off from the bearing part 81 and the supply roller 69 is taken out from inside the main body 61.

Next, insert the new supply roller 69 into the main body 6 from the front side.
1 along the guide 77.

As a result, the conical tip 7 of the shaft 76 on the rear side
6a comes into contact with the guide surface 87 of the bearing part 81, but if it is pushed in as it is, it will be guided upward and inserted into the receiving hole 86, where it will be pivotally supported. Thereafter, the front side frame 78 is attached, the shaft 75 is inserted into the bearing part 79 to receive the shaft, and then the spring 82 is attached. As a result, the bearing portion 79 is urged upward, and the supply roller 69 is brought into pressure contact with the pressure roller 62.

The supply roller 69 attached in this way rotates as the pressure roller 62 rotates, causing the silicone oil 71 inside to flow out from the through holes 72 of the cylindrical tube 70 and to release the silicone holder 73. The silicone oil 71 secreted from the felt 74 is supplied to the surface of the pressure roller 62 and applied thereto.

As described above, when replacing the supply roller 69, the supply roller 69 can be attached and detached from the front side while the rear spring 83 is still attached, which significantly improves work efficiency.

[Effect of the Invention 1] As explained above, according to the present invention, when replacing the supply roller, there is no need to remove the biasing members at both ends.
This has the effect that replacement work can be performed from the front side, and work efficiency can be significantly improved.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is a side sectional view showing a supply roller, FIG. 2 is an internal configuration diagram showing an electronic copying machine, FIG. 3 is a configuration diagram showing a fixing device, and FIG. FIG. 4 is a configuration diagram showing the support structure of the supply roller, FIG. 5 is a sectional view showing the bearing portion, and FIG. 6 is a front view thereof. 1... Device main body, 62... Pressure roller, 63...
Heating roller, 69... Supply roller, 71... Silicone oil, 75.76... Shaft, 77... Guide body, 79.81... Bearing part, 82.83... Spring (with 86... Receiving hole, 87... Guide surface. Applicant's agent Patent attorney Takehiko Suzue Figure 3 Figure 4

Claims (1)

[Claims] A heating roller and a pressure roller that comes into pressure contact with the heating roller are disposed in the main body of the device, and a supply roller for supplying silicone oil is slidably inserted along a guide body, and the supply roller has both ends thereof. The shaft has a shaft in the bearing part, and these shafts are supported by the receiving hole of the bearing part, and are urged by the urging member to be pressed against at least one of the heating roller and the pressure roller to supply silicone oil. The fixing device is characterized in that the tip of the shaft on the insertion end side of the supply roller is formed into a conical shape, and a guide surface that guides the tip of the shaft to the receiving hole is formed on a bearing portion that bears the shaft. Fixing device.