JP3628542B2 - Fixing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fixing roller, a pressure roller that makes a pair with the fixing roller and contacts the fixing roller, a liquid storage tank that stores an anti-offset liquid, and an anti-offset liquid applied to the peripheral surface of the fixing roller. And a liquid supply means for supplying the anti-offset liquid in the liquid storage tank to the application member, and the liquid supply means is inserted into a tube insertion port formed in the liquid storage tank. The present invention relates to a fixing device that has a tube and passes a recording material carrying a toner image between the rotating fixing roller and the pressure roller, and fixes the toner image on the surface of the recording material.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, it is well known to employ a fixing device of the above type in an image forming apparatus configured as a copying machine, a printer, a facsimile, or a copying machine having at least two functions thereof. According to this type of fixing device, since the offset prevention liquid is applied to the fixing roller, it is possible to suppress the occurrence of the offset phenomenon in which the toner moves to the surface thereof, and to suppress the problem that the recording material is stained with the toner.
[0003]
The offset preventing liquid is stored in the liquid storage tank, and the offset preventing liquid is supplied to the application member by the liquid supply means and applied to the fixing roller by the application member. In this way, the liquid storage tank contains the anti-offset liquid, but when an impact is applied to the liquid storage tank, the internal anti-offset liquid spills from the tube insertion port into which the tube is inserted, and the liquid storage tank is fixed. There is a possibility that the periphery of the apparatus is soiled by the offset prevention liquid.
[0004]
[Problems to be solved by the invention]
An object of the present invention is to provide a fixing device of the type described at the beginning, which can effectively suppress the above-mentioned conventional drawbacks with a simple configuration.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, in the fixing device of the type described at the beginning, the tube insertion port is defined by a tube tubular portion of a liquid storage tank, and the tube tubular portion A sensor insertion port into which the liquid end sensor is inserted is formed in the liquid storage tank, and the sensor insertion port is also defined by a sensor tubular portion of the liquid storage tank. A cylindrical portion projects into the liquid storage tank, a slit extending in the axial direction is formed in the sensor cylindrical portion, and an outer wall of the liquid end sensor is formed on an inner wall surface of the sensor cylindrical portion. A fixing device is proposed in which an annular convex portion is formed to engage with an annular groove formed on the surface (claim 1).
[0008]
Further, in the fixing device according to claim 1, it is advantageous that the tubular portion for tube and the tubular portion for sensor are each constituted by a separate member from the tank body (claim 2). .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the drawings.
[0010]
FIG. 1 is a front view of the fixing device 2 mounted on the image forming apparatus main body 1 as viewed from the front side. The fixing device 2 is on the front side of the image forming apparatus main body 1, that is, on the paper surface of FIG. On the other hand, it is supported so that it can be pulled out vertically. The fixing device 2 includes a fixing roller 10 and a pressure roller 11 that makes a pair with the fixing roller 10 and contacts the fixing roller 10, and these rollers 10 and 11 are attached to the frame 9 of the fixing device 2. It is supported rotatably. In FIG. 1, the support plate of the frame body 9 that supports the front end portions of the fixing roller 10 and the pressure roller 11 is omitted.
[0011]
FIG. 2 is a vertical sectional view cut along the fixing roller 10 and the pressure roller 11. As can be seen from this figure, heaters 16 and 17 are provided inside the fixing roller 10 and the pressure roller 11, respectively. The fixing roller 10 and the pressure roller 11 are heated by the heaters 16 and 17. Further, the fixing roller 10 and the pressure roller 11 are rotationally driven in directions indicated by arrows in FIG. 2 by a driving device (not shown) while being pressed against each other.
[0012]
A recording material P made of, for example, transfer paper to which a toner image T has been transferred in a transfer unit (not shown) in the image forming apparatus main body is disposed between the fixing roller 10 and the pressure roller 11 as indicated by an arrow A in FIG. Is conveyed between the rotating fixing roller 10 and the pressure roller 11. At this time, the toner image T on the recording material P is fixed on the recording material P by the action of heat and pressure from the fixing roller 10 and the pressure roller 11. The recording material P passes between the fixing roller 10 and the pressure roller 11 and is discharged from the fixing device 2 by the discharge roller pair 23 and is stacked on a discharge tray (not shown). As described above, the fixing device 2 serves to fix the toner image on the surface of the recording material by passing the recording material P carrying the toner image T between the rotating fixing roller 10 and the pressure roller 11.
[0013]
Further, the fixing device 2 has a liquid storage tank 25 supported by the frame body 9, and an offset prevention liquid S made of, for example, silicone oil is stored in the liquid storage tank 25 as shown in FIG. Yes. Further, the fixing device 2 includes an application member 29 that applies an offset prevention liquid to the peripheral surface of the fixing roller 10, and a liquid supply unit 3 that supplies the offset prevention liquid S in the liquid storage tank 25 to the application member 29. Have. The application member 29 is made of felt, for example, and is in contact with the peripheral surface of the fixing roller 10. The liquid supply means 3 has a tube 4 made of metal, resin, rubber, or the like, and a pump 5 interposed in the middle of the tube 4, and as shown in FIG. It is inserted into a tube insertion port 6 formed in the storage tank 25. The tube 4 extends to above the application member 29, and the pump 5 operates to pump up the offset prevention liquid S in the liquid storage tank 25, and the pumped offset prevention liquid passes through the tube 4 and is applied to the application member 29. It is sent upward and is supplied onto the application member 29 from here. The offset prevention liquid supplied to the application member 29 is applied to the peripheral surface of the fixing roller 10.
[0014]
Further, the regulating blade 12 is pressed against the peripheral surface of the fixing roller 10, whereby the anti-offset liquid applied to the peripheral surface of the fixing roller 10 is scraped off, and an appropriate amount of the anti-offset liquid is left on the peripheral surface of the fixing roller. . In this way, an appropriate amount of offset prevention liquid is applied to the peripheral surface of the fixing roller 10, and the occurrence of an offset phenomenon in which the toner on the recording material P is transferred to the peripheral surface of the fixing roller 10 is suppressed. Some of the toner adhering to the peripheral surface of the fixing roller 10 is removed by the cleaning roller 13 in contact with the peripheral surface of the fixing roller 10. The toner adhering to the cleaning roller is scraped off by the scraper 14.
[0015]
Excess offset prevention liquid supplied to the application member 29 is collected in the receiving member 31 through the support member 30 of the application member 29 and is similarly scraped off from the peripheral surface of the fixing roller 10 by the regulating blade 12. The liquid also travels through the support member 33 and is collected in the receiving member 31. The collected anti-offset liquid is received from the lower opening of the receiving member 31 at the inlet 16 formed in the upper part of the liquid storage tank 25 (see FIG. 3). And returned to the liquid storage tank 25.
[0016]
Further, as shown in FIG. 3, the liquid storage tank 25 has a sensor insertion port 18 into which the liquid end sensor 17 is inserted, and the sensor 17 eliminates the offset prevention liquid S in the liquid storage tank 25, or It is detected that the remaining amount has decreased, and the fact is displayed on a display unit (not shown). Accordingly, the cap 19 of the liquid storage tank 25 is opened, and the offset prevention liquid is supplied into the liquid storage tank 25 from the liquid supply port.
[0017]
As described above, since the tube insertion port 6 and the sensor insertion port 18 are formed in the liquid storage tank 25, in the conventional fixing device, when an impact is applied thereto, each of the insertion ports 6 and 18 is provided. There was a risk of spilling the internal anti-offset solution. For example, when the recording material P is jammed and the fixing device 2 is pulled out to handle this, and the fixing device 2 is pushed into the image forming apparatus main body after the processing, the fixing device 2 is moved vigorously. In some cases, the anti-offset liquid in the fixing device spills due to the impact.
[0018]
Therefore, in the fixing device 2 of the present example, as clearly shown in FIG. 3, the tube insertion opening 6 is defined by the tube tubular portion 15 of the liquid storage tank 25, and the tube tubular portion 15. Projecting into the liquid storage tank 25. Further, the above-described sensor insertion port 18 is formed in the liquid storage tank 25 of the fixing device 2 of this example, and this sensor insertion port 18 is also partitioned by the sensor tubular portion 20 of the liquid storage tank 25. The sensor tubular portion 20 also protrudes into the liquid storage tank 25. In the example shown in FIG. 3, both cylindrical portions 15 and 20 protrude from the inner wall surface of the liquid storage tank 25 to the inner side of the liquid storage tank 25 by a length indicated by L.
[0019]
With the above-described configuration, even when an impact is applied to the liquid storage tank 25, it is difficult for the offset prevention liquid in the liquid storage tank to spill from each of the insertion ports 6 and 18. FIG. 4A is a diagram for explaining this, and in the state in which the tube 4 is extracted from the tube insertion port 6 of the liquid storage tank 25, the liquid storage tank 25 is shaken, and the offset prevention liquid S inside. The behavior is shown. By shaking the liquid storage tank 25, when the internal offset prevention liquid S moves in the direction of the arrow B, the movement of the offset prevention liquid S is mitigated by the tube tubular portion 15 protruding into the liquid storage tank 25, The force with which the offset preventing liquid S hits the inner wall surface of the liquid storage tank 25 is reduced, and the offset preventing liquid is prevented from jumping out from the tube insertion opening 6.
[0020]
FIG. 4B shows a conventional liquid storage tank 25 that does not have a tube tubular portion protruding into the liquid storage tank 25. In this case, the offset prevention liquid S that has moved in the direction of arrow B is It jumps out from the tube insertion opening 6 along the inner wall surface of the liquid storage tank 25.
[0021]
As described above, by projecting the tube cylindrical portion 15 into the liquid storage tank 25, the offset prevention liquid S in the liquid storage tank 25 is effectively prevented from spilling outside through the tube insertion port 6. it can. The same applies to the sensor tubular portion 20.
[0022]
In addition, it is desirable that the receiving port 37 for returning the anti-offset liquid into the liquid storage tank 25 is also partitioned by a cylindrical portion, and the cylindrical portion 21 is projected into the liquid storage tank 25.
[0023]
Incidentally, in the illustrated liquid storage tank 25, as shown in FIG. 3, the tube tubular portion 15 and the sensor tubular portion 20 are each formed of a separate member from the tank body 25A. The tank body 25A is blow-molded with a material having excellent heat resistance and chemical resistance, such as polycarbonate, for example, but both cylindrical portions 15 and 20 are molded separately from the tank body 25A, and an adhesive is used later. Thus, the liquid storage tank 25 is configured by being joined and integrated with the tank body 25A. By adopting such a configuration, even when each of the cylindrical portions 15 and 20 has a complicated form, it can be molded, and the degree of freedom in setting the shapes of the cylindrical portions 15 and 20 Is increased.
[0024]
5A is a perspective view of the sensor tubular portion 20 and the liquid end sensor 17 inserted therein, and FIG. 5B is a horizontal sectional view of the sensor tubular portion 20. . As can be seen from this figure, the sensor tubular portion 20 has a plurality of slits 26 extending in the axial direction thereof, and an annular convex portion 27 is formed on the inner wall surface of the sensor tubular portion 20. ing. On the other hand, an annular groove 28 is formed on the outer peripheral surface of the liquid end sensor 17. When the liquid end sensor 17 is inserted into the sensor insertion port 18 inside the sensor tubular portion 20, the liquid end sensor 17 presses the sensor tubular portion 20 in the radial direction, and opens the sensor end portion in that direction. Finally, the annular concave groove 28 of the liquid end sensor 17 and the annular convex portion 27 of the sensor tubular portion 20 are engaged, and these are strongly engaged by the elasticity of the sensor tubular portion 20. . As a result, the liquid end sensor 17 is firmly held in the liquid storage tank 25.
[0025]
Conventionally, it has been necessary to hold the liquid end sensor inserted into the sensor insertion port of the liquid storage tank on the frame of the fixing device via the mounting member. However, according to the fixing device 2 of this example, the cylindrical shape for the sensor is used. An annular convex portion 27 that engages with an annular concave groove 28 formed on the outer peripheral surface of the liquid end sensor 17 is formed on the inner wall surface of the portion 20, and both are firmly engaged. No member is required, and the cost of the fixing device 2 can be reduced.
【The invention's effect】
According to the first aspect of the present invention, the tube insertion port is defined by the tube cylindrical portion of the liquid storage tank, and the tube cylindrical portion protrudes into the liquid storage tank. It is possible to prevent the anti-offset liquid in the liquid storage tank from spilling from the mouth. In addition, the sensor insertion port is also defined by the sensor cylindrical portion of the liquid storage tank, and the sensor cylindrical portion protrudes into the liquid storage tank, so that the anti-offset liquid in the liquid storage tank from the sensor insertion port. Prevents spills. Furthermore, the liquid end sensor can be firmly held in the liquid storage tank without using an independent mounting member for the liquid end sensor.
[0029]
According to the invention which concerns on Claim 2, since the said cylindrical part for tubes and the cylindrical part for sensors are comprised by the member separate from the tank main body, respectively, the cylindrical part for tubes and the cylindrical form for sensors The degree of freedom in designing the part can be increased.
[Brief description of the drawings]
FIG. 1 is a front view of a fixing device.
FIG. 2 is a vertical sectional view of the fixing device.
FIG. 3 is a partial cross-sectional view of a liquid storage tank.
FIG. 4 is a diagram for explaining the effect of preventing the spillage of the offset preventing liquid.
FIG. 5 is a diagram showing a liquid end sensor and a sensor tubular portion.
[Explanation of symbols]
2 Fixing device 3 Liquid supply means 4 Tube 6 Tube insertion port 10 Fixing roller 11 Pressure roller 15 Tube tubular portion 18 Sensor insertion portion 20 Sensor tubular portion 25 Liquid storage tank 26 Slit 27 Annular convex 28 Annular concave groove 29 Coating member P Recording material S Offset prevention liquid T Toner image

Claims (2)

A fixing roller; a pressure roller that makes a pair with the fixing roller and contacts the fixing roller; a liquid storage tank that stores an anti-offset liquid; and an application member that applies the anti-offset liquid to the peripheral surface of the fixing roller. A liquid supply means for supplying the anti-offset liquid in the liquid storage tank to the coating member, and the liquid supply means has a tube inserted into a tube insertion port formed in the liquid storage tank. In a fixing device for passing a recording material carrying a toner image between the rotating fixing roller and the pressure roller, and fixing the toner image on the surface of the recording material,
The tube insertion port is defined by a tube cylindrical portion of the liquid storage tank, the tube cylindrical portion protrudes into the liquid storage tank, and a liquid end sensor is inserted into the liquid storage tank. A sensor insertion port is formed, the sensor insertion port is also defined by a sensor cylindrical portion of the liquid storage tank, the sensor cylindrical portion protrudes into the liquid storage tank, and the sensor cylindrical portion includes: A slit extending in the axial direction is formed, and on the inner wall surface of the cylindrical portion for the sensor, an annular convex portion that engages with an annular groove formed on the outer peripheral surface of the liquid end sensor is formed. A fixing device characterized by the above. 2. The fixing device according to claim 1, wherein each of the tube tubular portion and the sensor tubular portion is formed of a member separate from the tank body.

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