JP2002207384A - Fixing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately supply releasing agent to a fixing roller, even when an image forming device equipped with a fixing device tilts. SOLUTION: The fixing device is provided with the rotating fixing roller, a pressure roller which is rotated in press contact with the fixing roller, a heating member for heating at least one of the fixing roller and the pressure roller, a releasing agent supply part for supplying liquid releasing agent to one of the surfaces of the fixing roller and the pressure roller, and the releasing agent supply part is provided with a slender cylindrical container for storing the releasing agent and with several releasing agent discharge holes in an axial line, the cylindrical container is arranged above one of the fixing roller and the pressure roller in a nearly parallel state, and also, arranged making the releasing agent discharge holes face upwards, and a guiding part for guiding the releasing agent spreading in the outer peripheral surface after being discharged from the discharge holes downwards is arranged on the outer peripheral surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device,
In particular, the present invention relates to a fixing device having a function of supplying a release agent (oil) to a fixing roller or a pressure roller.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine or a printer, a fixing device for fixing a toner image on recording paper is usually a pressure roller which presses silicone oil (release agent) against a fixing roller or a fixing roller. To prevent the deviation of the fixed image and the wrapping of the recording paper so that stable image formation can be performed.

[0003] As a method of applying oil to the roller of such a fixing device, an oil pipe having a plurality of oil discharge holes in a line is installed above the roller, and oil is discharged from the discharge holes to form a rain downward. It is known that the liquid is dropped and applied to a roller (for example, Japanese Patent Application Laid-Open
-137317).

[0004]

However, when the oil discharged from the plurality of discharge holes of the pipe falls along the outer peripheral surface of the pipe and from the lower surface of the pipe, the installation state of the image forming apparatus main body is inclined. In such a case, since the pipes are also inclined together, the oil is transmitted to the lower side of the pipe, and the preset dropping position of the oil is different. Therefore, there is a problem in that the oil supply to the roller becomes uneven, and in particular, in a portion where the oil supply amount of the roller is insufficient, a deviation of the fixed image and a winding of the recording paper occur.

The present invention has been made in consideration of such circumstances, and even when the image forming apparatus main body is installed at an angle, the oil (release agent) is uniformly supplied to the fixing roller or the pressure roller. It is an object of the present invention to provide a fixing device having a releasing agent supply function.

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided a fixing roller which rotates, a pressing roller which rotates by pressing against the fixing roller, a heating member for heating at least one of the fixing and pressing rollers, a fixing and heating unit. A release agent supply unit that supplies a liquid release agent to at least one surface of the pressure roller,
The release agent supply unit includes an elongated cylindrical container that contains the release agent and has a plurality of release agent discharge holes in a line in the axial direction, and the cylindrical container is substantially above one of the fixing and pressure rollers. The fixing is characterized by being provided in parallel with the release agent discharge hole facing upward, and having a guide portion on the outer peripheral surface for guiding the release agent discharged from the discharge hole and transmitted through the outer peripheral surface downward. An apparatus is provided.

BEST MODE FOR CARRYING OUT THE INVENTION

The fixing roller and the pressure roller according to the present invention may be formed by covering a metal cylindrical core (for example, an aluminum pipe) with an elastic material layer (for example, a silicone rubber layer). As a heating member, an electric heater (for example, a halogen lamp) can be used by being mounted inside a cylindrical core of a roller.

The fixing roller is driven by a driving source (for example, a motor) and rotates at a constant peripheral speed. It is preferable that a liquid release agent is supplied from a tank to the cylindrical container of the release agent supply unit by a small pump such as a piezo-type or electromagnetic pump.

In this case, the inner diameter of the cylindrical container is determined by the discharge capacity of the pump. For example, when the pump discharge capacity is (3 to 30 g / min), the inner diameter of the cylindrical container is 5 to 10 mm. Appropriate. The material of the cylindrical container is not particularly limited, but a commercially available pipe made of aluminum, iron or brass can be used.

The release agent discharge hole of the cylindrical container is 0.5 to
It preferably has a diameter of 1.5 mmφ, and the discharge hole can be formed by, for example, press working or laser processing. The plurality of release agent discharge holes means about 3 to 10 discharge holes.

When the release agent is supplied from one end of the cylindrical container, the diameter of the release agent discharge hole is gradually increased from the upstream side to the downstream side of the cylindrical container in consideration of the pressure loss. The amount may be made uniform.

The guide portion may be an elongated projecting portion provided around each of the release agent discharge holes at both ends,
It may be an elongated projection provided around each of the plurality of release agent discharge holes. Further, the guide portion may be a groove provided along a circumference passing through the release agent discharge hole in a direction perpendicular to the axis of the cylindrical container.

The protruding portion may be formed directly on the outer peripheral surface of the cylindrical container using an adhesive or the like. In this case, a thermosetting epoxy diameter adhesive or the like is used as the adhesive. it can.

The protruding portion is formed into a ring shape with a resin having excellent heat resistance such as PPS (polyphenylene sulfide), PET (polyethylene terephthalate), PAI (polyamide imide), and PEEK (polyether ether ketone). You may use what was done. The protruding portion may have a trapezoidal, square, semicircular, or polygonal cross section, but preferably has a height of about 1 to 3 mm.

Further, the guide portion may be a groove provided corresponding to each of the release agent discharge holes at both ends, or may be provided corresponding to each of the plurality of release agent discharge holes. Groove may be used. Further, the guide portion may be a groove provided along a circumference passing through the release agent discharge hole in a direction perpendicular to the axis of the cylindrical container.

The above-mentioned groove can be formed on the outer peripheral surface of the cylindrical container by machining, and the cross-sectional shape may be a U-shaped or V-shaped. Preferably, the width and depth of the groove are determined in consideration of the discharge amount of the release agent and the thickness of the cylindrical container.

As the release agent, dimethyl silicone oil having a viscosity of 100 CS to 300 CS can be used, but modified silicone oil (for example, reactive silicone oil, non-reactive silicone oil, etc.) can be used. good. However, if the viscosity is high, it becomes difficult to suck up the pump, which is not preferable.

Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings. Note that the present invention is not limited to this. FIG. 1 is a perspective view of a main part of a fixing device according to an embodiment of the present invention, and FIG. 2 is a side view thereof. As shown in these drawings, the fixing device 100 has a fixing roller 1 and a pressure roller 2 arranged so as to be in pressure contact with each other. Each of the fixing roller 1 and the pressure roller 2 has a rubber layer made of silicone rubber on an aluminum pipe, and has heaters 3 and 4 formed of halogen lamps inside the pipe.

Around the fixing roller 1, an upper peeling claw 11,
An upper cleaning roller 9, a fixing roller temperature detector 5, and an oil application roller 7 are provided. Pressure roller 2
Around the lower peeling claw 12, the lower cleaning roller 1
0, a pressure roller temperature detector 6 is provided.

The upper and lower peeling claws 11 and 12 are
The recording paper wound around the roller 2 is peeled off from the surfaces of the rollers 1 and 2. Upper and lower cleaning rollers 9 and 10
Is a roller having a felt surface, which is in sliding contact with the surfaces of the rollers 1 and 2, and collects the offset toner adhered to the surfaces of the rollers 1 and 2.

The oil application roller 7 is a roller whose surface is made of rubber, and applies oil as a release agent to the surface of the fixing roller 1 that comes into contact. The fixing and pressure roller temperature detectors 5 and 6 are composed of thermistors and detect the surface temperatures of the fixing and pressure rollers 1 and 2 with which the fixing and pressure roller contact. The temperature detection results of the fixing and pressure roller temperature detectors 5 and 6 are sent to a fixing controller (not shown).

The fixing control section controls the operation of the power supply unit based on the detection results of the fixing and pressure roller temperature detectors 5 and 6, and heats the heaters 3 and 4 as heat sources in the rollers 1 and 2.
Is turned ON / OFF to adjust the temperature of the rollers 1 and 2.

Next, a method of supplying oil to the oil application roller 7 for applying oil (liquid has been released) to the fixing roller 1 in the fixing device 100 will be described in detail.

Oil is stored in an oil tank 20 provided below the fixing device 100. The pump 21 installed on the upper part of the oil tank 20
Oil is supplied from 0 to one end of the pipe member 22 through the tube 26. The pipe member 22 is installed above the fixing roller 1 in parallel with the fixing roller 1.

As shown in FIG. 1, the pipe member 22 has a plurality of oil discharge holes 22a in a row at the top of the outer peripheral surface. When the pump 21 operates, a plurality of discharge holes 2 of the pipe member 22 are formed.
The oil is discharged from 2a and drops along the outer circumference of the pipe member 22 onto the felt 23 for oil supply in the form of rain. The oil may be dropped directly onto the application roller 7. The other end of the pipe member 22 is sealed.

The dropped oil passes through the felt 23,
The oil is applied to the oil application roller 7. Oil application roller 7
The oil adhering to the film is made uniform by a coating blade 24 made of rubber.

Excess oil that has not adhered to the oil application roller 7 is collected by a dish-shaped oil pan 25 installed at the lower part, and is formed in a tubular shape 28 connected to the oil pan.
As a result, the oil is returned to the oil tank 20.

The oil is stored in the oil tank 20 and the pipe member 2.
The oil circulates between the two, and the amount of oil in the oil tank 20 is detected by an oil remaining amount detection sensor 27 and displayed on a display panel (not shown).

Next, the structure and operation of the pipe member 22 will be described in detail. FIG. 3 is an explanatory view of a main part configuration of the fixing device shown in FIG. 2. The pipe member 22 has substantially the same length as the fixing roller 1 and the pressure roller.
Oil discharge holes 22a are provided at equal intervals, and the distance Do between the oil discharge holes 22a at both ends is equal to the length D of the felt 23.
f and the width Dp of the recording paper P are set slightly shorter.

As shown in FIG. 3, oil discharge holes 22 at both ends are provided.
The annular rings 30 made of PPS resin are fitted and adhered to a, respectively, as guides for guiding the oil downward.
As shown in the cross-sectional view of FIG. 4, the ring 30 is provided around a portion passing through the oil discharge hole 22a in a direction perpendicular to the axis of the pipe member 22 except for the oil discharge hole 22a.

The oil discharged from the oil discharge holes 22a at both ends is guided by the ring 30 and drops downward as shown in FIG. 3, and the oil discharged from the other oil discharge holes 22a is a pipe member. 22 and falls down along the outer peripheral surface.

In such a configuration, the image forming apparatus provided with the fixing device is installed inclined for some reason,
When the pipe member 22 inclines accordingly, the oil discharged from the oil discharge holes 22a at both ends is guided by the ring 30 and falls downward as shown in FIG. 5, but is discharged from the other oil discharge holes 22a. Oil is pipe member 22
Part of the pipe member 22
The cross flow occurs due to the inclination of However, since the ring 30 on the downstream side prevents the lateral flow, the oil is prevented from dropping to unnecessary parts.

FIG. 6 is a front view showing a modified example of the pipe member 22 shown in FIG. 3. In this case, the rings 30 are provided in all the oil discharge holes 22a of the pipe member 22, respectively. It is equivalent to FIG.

In this example, even if the pipe member 22 is inclined,
The oil discharged from the five oil discharge holes 22a is guided downward by each ring 30, as shown in FIG. 6, so that the oil is evenly distributed on the felt 23 (FIG. 3) with almost no lateral flow. In addition to dropping, it is prevented from dropping to an unnecessary part.

The guide for guiding the oil downward is
Instead of the ring 30 shown in FIGS. 3 and 6, a U-shape or a circle formed along the circumference passing through the oil discharge hole 22a in a direction perpendicular to the axis of the pipe member 22 as shown in FIGS. It may be constituted by a V-shaped groove 30a. The groove 30a shown in FIGS. 7 and 8 has the same operation and effect as the ring 30 shown in FIGS. 3 and 6, respectively.

[0036]

According to the present invention, even if the image forming apparatus equipped with the fixing device is installed at an angle, the release agent supply section prevents the lateral flow of the release agent, so that the release agent is unnecessary. It is not supplied to the place but is supplied appropriately.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a main part of a fixing device according to an embodiment of the present invention.

FIG. 2 is a side view of the fixing device shown in FIG.

FIG. 3 is an explanatory diagram of a main configuration of the fixing device shown in FIG. 1;

FIG. 4 is a sectional view of the pipe member shown in FIG. 3;

FIG. 5 is an explanatory diagram illustrating an operation of the fixing device illustrated in FIG. 3;

6 is a main part front view showing a modification of the embodiment shown in FIG. 1;

FIG. 7 is a front view of a main part showing still another modified example of the embodiment.

FIG. 8 is a front view of a main part showing still another modified example of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixing roller 2 Pressure roller 3 Heater 4 Heater 7 Oil application roller 20 Oil tank 21 Pump 22 Pipe member 22a Oil discharge hole 23 Felt 25 Oil pan 26 Tube 27 Oil remaining amount detection sensor 28 Tube 30 Ring

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Atsushi Ide 22-22, Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Inside (72) Inventor Yasunori Mizuguchi 22-22, Nagaike-cho, Abeno-ku, Osaka-shi, Osaka (72) Inventor Kazuhiro Matsuyama 22-22 Nagaike-cho, Abeno-ku, Osaka City, Osaka F-term (reference) 2H033 AA09 BA43 BA44 4F040 AA05 AB20 AC01 BA14 CB21 CB29

Claims (7)

[Claims] A fixing roller configured to heat at least one of the fixing and pressure rollers; a heating member configured to heat at least one of the fixing and pressure rollers; A release agent supply unit for supplying a liquid release agent, the release agent supply unit including an elongated cylindrical container containing the release agent and having a plurality of release agent discharge holes in a line in the axial direction. The cylindrical container is installed substantially parallel to one of the fixing and pressure rollers, and the release agent discharge hole is directed upward, and the release agent discharged from the discharge hole and transmitted along the outer peripheral surface is downwardly moved. A fixing portion provided on an outer peripheral surface of the fixing device. 2. The guide portion comprises elongated protrusions provided around the release agent discharge holes at both ends, respectively.
The fixing device as described in the above. 3. The fixing device according to claim 1, wherein the guide portion comprises an elongated protrusion provided around each of the plurality of release agent discharge holes. 4. The guide portion comprises an elongated projection provided at a portion other than the release agent discharge hole along a circumference passing through the release agent discharge hole in a direction perpendicular to the axis of the cylindrical container. 4. The fixing device according to 2 or 3. 5. The fixing device according to claim 1, wherein the guide portion is formed by a groove provided in a manner corresponding to each of the release agent discharge holes at both ends. 6. The fixing device according to claim 1, wherein the guide portion is formed by a groove provided corresponding to each of the plurality of release agent discharge holes. 7. The fixing device according to claim 5, wherein the guide portion comprises a groove provided along a circumference passing through the release agent discharge hole in a direction perpendicular to the axis of the cylindrical container.