JP2606933B2 - Fixing device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fixing device of an image forming apparatus such as a copying machine or a laser beam printer that employs an electrophotographic system.

(Prior Art) In an image forming apparatus such as a copying machine, when a toner image is transferred from an image carrier onto a transfer sheet, the transfer sheet is conveyed to a fixing device, and the toner image is fixed on the transfer sheet as a permanent image. Is done.

An example of the fixing device will be described with reference to FIG.
Reference numeral 100 denotes a heating roller in which a heater is provided and the outer surface temperature of which is maintained at a predetermined fixing temperature.
A pressure roller 101 is pressed against 100. The heating and pressing roller 10 is a fixing roller that rotates in a certain direction.
When the transfer paper P carrying the toner image is transported between 0 and 101, the transfer paper P is transported while being nipped between the heating and pressure rollers 100 and 101, and the toner image is heated and melted and fixed on the transfer paper. Be established.

The heating roller 100 is provided with a cleaner 110 in the axial direction to clean the toner and the like adhered by the fixing operation around the heating roller 100, and to apply an oil such as silicon oil around the heating roller 100 to heat the heating roller 100. The adhesion of the toner to the roller 100 is prevented.

After the felt portion 111 is positioned in the hole portion 121 of the fixing device main body 120 so that the felt portion 111 comes into contact with the heating roller 100, the cleaner 110 is rotated by a fixing cover 130 that rotates vertically about a support shaft 131. , And is pressed down by the heating roller 100.

On the other hand, the cleaner 110 generally needs to be replaced every 3,000 to 4,000 sheets of the transfer paper P, and the replacement frequency is low. Once the cleaner 110 is mounted in the fixing device, the fixing cover 130 is raised and the cleaner 110 is removed. Is slight.

(Problems to be Solved by the Invention) However, despite the fact that the number of replacements of the cleaner 110 is small, the attachment / detachment mechanism of the cleaner 110 is not simple.

That is, the fixing cover 130 and the spring member 132 are required, and the fixing cover 130 is required to have a stopper (not shown) for preventing the fixing cover 130 from opening against the elastic force of the spring member 132. The number of parts was large and there was a problem in cost. In addition, when the cleaner 110 is replaced by opening the fixing cover 130, a sufficient gap is required between the cleaner 110 and the fixing cover 130 for attaching and detaching the cleaner 110, and thus there is a disadvantage that the apparatus becomes larger.

Also, as in the fixing device shown in FIG.
In the clamshell type in which the upper unit 200 of the image forming apparatus is pressed via the spring member 132, the fixing cover 130 as described above is unnecessary, and the cleaner 110 can be easily replaced. When the upper unit 200 is opened around the support shaft 201 for jam processing or the like, the pressing of the cleaner 110 against the heating roller 100 is also released.
When the unnecessary transfer paper P is pulled out from between the positions 0 and 101, the unfixed toner on the transfer paper P adheres to the heating roller 100 without being sufficiently cleaned, and the subsequent transfer paper P is contaminated on several sheets. there were.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a fixing device in which a cleaner of a fixing roller can be attached and detached with a simple mechanism, and the function of the cleaner can be sufficiently exerted even in the case of a jam clearance. To be.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes a cleaner which is detachably provided to a fixing device main body and which is pressed by a fixing roller to clean an outer surface of the fixing roller. In the fixing device, a cam portion is formed on the cleaner main body itself or a handle portion pivotally supported by the cleaner main body, and a first spring member for pressing the cleaner is fixed on the fixing device main body side to fix the first spring member and the fixing member. The cleaner positioned between the rollers is rotated by rotating the cleaner main body or the handle portion to engage the cam portion with the spring member, and the cleaner is attached to the fixing device main body.

According to a second aspect of the present invention, there is provided a fixing device having a cleaner which is detachably provided to a fixing device main body and is pressed by a fixing roller to clean an outer surface of the fixing roller. A handle portion movably supported is provided, and a cam portion is provided on the handle portion for pressing the cleaner body downward via a second spring member by the rotation thereof, and the handle portion is locked to the fixing device body. In this state, the cleaner body is pressed against the fixing roller by the rotation of the handle portion, and the cleaner is attached to the fixing device body.

(Operation) In the first invention, when the cleaner is attached to the fixing device main body, the cleaner is positioned between the fixing roller and the first spring member, and then the cleaner main body or the handle portion is rotated so that the cam portion is connected to the first spring member. To attach the cleaner to the fixing device main body. The operation of removing the cleaner from the fixing device main body may be the reverse of the above operation.

Further, in the second invention, in order to attach the cleaner to the fixing device main body, first, the cleaner main body is placed on the fixing roller,
The handle is stopped on the fixing device body. Thereafter, when the handle portion is rotated and the fixing portion is pressed downward by the cam portion via the second spring member, the cleaner body is vertically movable with respect to the handle portion and is pressed toward the fixing roller. The cleaner can be attached to the fixing device main body.
The operation of removing the cleaner from the fixing device main body may be the reverse of the above operation.

(Example) Hereinafter, an example of the present invention will be described with reference to the accompanying drawings.

First, a first embodiment of the present invention will be described with reference to FIGS.

First, an outline of an image forming operation by an image forming apparatus such as a laser beam printer will be described with reference to FIG.
Reference numeral 1 denotes a photosensitive drum serving as an image carrier that rotates in a fixed direction. Around the photosensitive drum 1, a primary charger 2, a developing device 3, a transfer charger 4 and a cleaning device 5 are provided. A fixing device 6 is disposed on the side of the sheet 1.

That is, when the photosensitive drum 1 uniformly charged by the primary charger 2 is exposed to image light L from a scanner unit or the like (not shown), an electrostatic latent image is formed on the photosensitive drum 1.
The electrostatic latent image is directed toward the developing device 3 with the rotation of the photosensitive drum 1, and toner is supplied by the developing device 3 to be visualized as a toner image.
Is transferred onto the transfer device P.

On the other hand, the transfer paper P is conveyed toward the photosensitive drum 1 and the transfer charger 4 at a timing adjusted by a paper supply system (not shown), and the toner image on the photosensitive drum 1 is transferred through the transfer charger 4. When the toner image is transferred, the toner image is conveyed toward the fixing device 6, and the toner image is fixed on the transfer paper P as a permanent image by the fixing device 6. After the transfer, the photosensitive drum is cleaned of residual toner by the cleaning device 5 and is prepared for the next image formation.

Next, the fixing device 6 according to the present invention will be described with reference to FIG. In the figure, reference numerals 12 and 13 denote a pair of fixing rollers including heating and pressing rollers, which have a function of fixing the toner image on the transfer paper P as a permanent image. The heating roller 12 is driven to rotate in the direction of the arrow shown in the figure, has a halogen heater 12a inside, and the outer surface temperature is heated to a fixed fixing temperature.
14 is contacted, and the outer surface temperature of the heating roller 12 is detected by the thermistor 14 to control the halogen heater 12a. A pressure roller 13 disposed below the heating roller 12 is urged toward the heating roller 12 by a spring member or the like (not shown), and is pressed against the heating roller 12 to form a nip between the heating roller 12 and the heating roller 12. 19 is formed, and is rotated following the heating roller 12.

Separation claws 17 for separating the transfer paper P attached to the heating roller 12 via the toner image from the heating roller 12 are provided on the discharge side of the heating and pressing rollers 12 and 13, and the transfer on which the toner image is fixed is provided. An unloading roller pair 15,1 for unloading the paper P out of the fixing device 6
6 and an intermediate guide 18 for guiding the transfer paper P unloaded from the heating and pressing rollers 12 and 13 toward the unloading roller pair 15 and 16, and the like. Transfer paper P on paper side
An inlet guide 11 is provided to guide the heat toward the nip 19 between the heating and pressure rollers 12, 13.

That is, when the transfer paper P carrying the toner image on its upper surface is conveyed toward the fixing device 6, the transfer paper P is guided by the entrance guide 11 and the nip portion 1 of the heating and pressing rollers 12, 13 is provided.
Sent to 9. Then, the toner image on the transfer paper P is heated and melted by the heating and pressure rollers 12 and 13 and fixed on the transfer paper P as a permanent image. In this case, the transfer sheet P adheres to the heating roller 12 via the toner image. However, the transfer sheet P is peeled off from the heating roller 12 by the separation claw 14, and the transfer sheet pair And is carried out of the fixing device 6 by the carry-out roller pairs 15 and 16.

If the toner on the transfer sheet P adheres to the outer surface of the heating roller 12 during the fixing operation, the image on the transfer sheet P is disturbed, and the adhered toner is transferred to the transfer sheet P in the next fixing operation.
There is a disadvantage that it adheres to the top. Because of this heating roller
12 is provided with a cleaner 20 for wiping toner adhered to the surface of the heating roller 12 and applying oil such as silicone oil to the surface of the heating roller 12 to reduce the adhesion of the toner to the heating roller 12. ing.

The cleaner 20 is provided in the axial direction of the heating roller 12, and is provided with a pad 21 pressed by the heating roller 12, a cleaner main body 22 holding the pad 21, and a cleaner main body 22.
And a handle 23 and the like fixed in an ax shape to the fixing roller body 10 so that it can be attached to and detached from the outer surface of the heating roller 12 from the cleaner mounting portion 30 on the upper right side of FIG. It has become.

Guide pins 24, 24 having a circular cross section protrude from both ends of the cleaner body 22 in the axial direction of the heating roller 22, and the cleaner body 22 near the guide pins 24, 24 is on the opposite side to the heating roller 22, Cam portions 25, 25 whose central portions project in a mountain shape are formed. In FIG. 1, the guide pins 24, 24 and the cam 2
Both 5, 25 are shown on only one side. On the other hand, the side walls 10a, 10a of the fixing device main body 10 forming the cleaner mounting portion 30 are engaged with the guide pins 24, 24 of the cleaner 20, and
Side grooves 31, 31 for guiding 0 toward the heating roller 12 are formed. Further, supporting springs 32, 32 for pressing the cleaner 20 are mounted on the sheet feeding side front wall 10b of the fixing device main body 10 on the lower side of the cleaner mounting section 30 at positions facing the cam sections 25, 25 of the cleaner 20. I have. The upper portion of the support spring 32 extends upward along the side groove 31 of the side wall 10a of the fixing device main body 10, and the distal end thereof has a pressing shape bent in the shape of a triangle toward the inside of the cleaner mounting portion 30. The pressing portion 32a is engaged with the cam portion 25 of the cleaner 20 and the cleaner 20 is
Has the function of pressing the pressure.

In order to replace the cleaner 20 of the fixing device 6 with a new one, the handle 23 in FIG.
The cleaner 20 can be removed from the cleaner mounting portion 30 by raising the 4, 24 along the side grooves 31, 31. in this case,
Since the pressing portions 32a, 32a of the support springs 32, 32 are pushed outward by the cam portions 25, 25 as the cleaner body 22 rotates, the cleaner 20 can be easily removed from the cleaner mounting portion 30. it can.

When attaching a new cleaner 20 to the cleaner mounting portion 30, the guide pins 24, 24 of the cleaner body 22 are lowered while engaging the guide pins 24, 24 of the cleaner main body 22 with the side grooves 31, 31 of the cleaner mounting portion 30 with the pad portion 21 facing downward. In this case, the pressing portion 32a of the support spring 32 hinders the lowering of the cleaner main body 22, but the pressing portion 32a of the support spring 32 is pressed outward by the lower portion of the cleaner main body 22, and the support spring 32 is bent outward. Therefore, the cleaner body 22 can be easily lowered.) When the handle 23 is turned downward around the guide pins 24 at the stage where the cleaner body 22 has been lowered to the predetermined position, the pad portion 21 And the cam portions 25, 25 of the cleaner body 22 are engaged with the pressing portions 32a, 32a of the support springs 32, 32, and the cleaner body 20 is pressed toward the heating roller 12 by the support springs 32, 32. Is positioned and fixed.

As described above, the cleaner 20 moves the guide pins 24, 24 along the side grooves 31, 31 of the cleaner mounting portion 30, and engages and disengages the cams 25, 25 with the support springs 32, 32 by simple means. The apparatus can be attached to and detached from the fixing device main body 10, and the size and simplification of the apparatus and the cost can be reduced as compared with a conventional apparatus using a fixing cover or the like. In addition, a large space is not required for attaching and detaching the cleaner 20.

Next, a second embodiment of the present invention will be described with reference to FIG. Components having the same functions as those of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the fixing device 6 according to the present embodiment, the cleaner mounting portion 30 is provided on the upper side of the fixing device main body 10, and the thermistor 14 for detecting the temperature of the heating roller 12 is disposed at a position close to the paper feeding side of the heating roller 12. Have been.

Support protrusions 22a, 22a are formed at both ends of the cleaner main body 22 holding the pad portion 21, and holes 22 of the support protrusions 22a, 22a are formed.
Both ends of a horizontal portion 23a of a T-shaped handle 23 are pivotally supported at a-1, 22a-1. The horizontal portion 23a of the handle 23 has a handle 23 near the support protrusions 22a and 22a of the cleaner body 22.
Cam portions 25, 25 are formed toward the center grip portion 23b. Also, the support springs 32, 32
, One end of which is supported by the upper wall 10c of the fixing device main body 10, and the other end is a free end and extends above the cleaner mounting portion 30. And support spring
Pressing portions 32a, 32a slightly inclined to the free end side are formed in portions of the 32, 32 disposed above the cleaner mounting portion 30.

Thus, the gripper 23b of the handle 23 of the cleaner 20 is bent in a hook shape with respect to the cleaner main body 22, that is, in a horizontal state, and the cleaner 20 is positioned in the cleaner mounting portion 30 of the fixing device main body 10. . In this state, the pad section 21 is in a state of lightly contacting the surface of the heating roller 12. Next, handle
If the rotating member 23 is rotated by 90 degrees counterclockwise in FIG. 3 with respect to the cleaner main body 22 so that the grip portion 23b is in a vertical state as shown by a chain line, the cam portions 25, 25 are in an upwardly convex state. And engage with the pressing portions 32a, 32a of the support springs 32, 32. Thus, the support springs 32, 32 are lifted slightly upward.
Is pressed and fixed.

In order to remove the cleaner 20 from the fixing device main body 10, the operation exactly opposite to the above operation may be performed.

As described above, also in this embodiment, the cleaner 20 can be attached to and detached from the fixing device main body 10 with a small and simple mechanism, and the same effect as that of the first embodiment can be obtained.

Next, a third embodiment of the present invention will be described with reference to FIGS. Note that components having the same functions as those according to the first and second embodiments are denoted by the same reference numerals, and description thereof is omitted.

In this embodiment, the cleaner 23 has a pad portion 21, a cleaner body 22 having the pad portion 21, and T-shaped members rotatably supported by support protrusions 22a provided at both ends of the cleaner body 22. Of the handle 23 etc.,
A hole 22a-1, which is provided on the support projection 22a and in which the horizontal portion 23a of the handle 23 engages, is a vertically oriented elongated hole, and both outer ends 23a-1, 23a of the handle horizontal portion 23a. Reference numeral -1 protrudes outward from the support protrusions 22a, 22a, and its shape is a cross section that is substantially circular and has a shape similar to a substantially rectangular shape having a width of 1 on both sides thereof.

Further, cam portions 25, 25 protruding in a direction orthogonal to the center grip portion 23b are formed in the handle horizontal portion 23a near the support protrusions 22a, 22a, and the cam portion 25 is formed on the upper side of the cleaner main body 22. , 25 are fitted with U-shaped spring members 33, 33.

On the other hand, at both ends of the cleaner mounting portion 30 provided on the upper side of the fixing device main body 10, the guide groove 34a and the locking groove 34b of the cleaner 20 are provided.
There is provided a pair of cleaner guide plates 34 each formed with. The guide groove 34a is formed slightly larger than the length l of one side of both outer end portions 23a-1, 23a-1 of the handle horizontal portion 23a of the cleaner 20, and the locking groove 34b is formed at the lower end of the guide groove 34a. It is provided and is formed in a circular shape slightly larger than the outer shape of the handle horizontal portion 23a.

Thus, the cleaner 20 is connected to the cleaner mounting portion of the fixing device main body 10.
In order to attach the handle 23, as shown in FIG. 5, the handle 23b of the handle 23 is turned upward, and the horizontal size of the outer ends 23a-1, 23a-1 of the handle horizontal portion 23a is set to l. To engage the outer ends 23a-1, 23a-1 of the handle horizontal portion 23a with the guide grooves 34a, 34a of the cleaner guide plates 34, 34.
The cleaner 20 is lowered into the cleaner mounting portion 30 along 34a.

When the pad portion 21 is placed on the heating roller 12, the outer ends 23a-1, 23a-1 of the handle horizontal portion 23a are positioned in the cleaner guide plate and the locking grooves 34b, 34b of the 34, 34. However, when the handle 23 is turned 90 degrees clockwise in FIG. 4 in this state, the handle horizontal portion 23a also turns 90 degrees as shown by the chain line in FIG. The handle 23 is also positioned and supported by the cleaner guide plates 34, 34 because -1, 23a-1 is locked in the locking grooves 34b, 34b. In this case, the cam portion 2 is
5, 25 presses the cleaner main body 22 downward through the spring members 33, 33, so that the cleaner main body 22 is pressed downward along the holes 22a-1, 22a-1 of the support protrusions 22a, 22a, and Pad part 21
Is pressed by the heating roller 12.

As described above, also in this embodiment, the cleaner 20 of the fixing device 6 can be attached to the fixing device main body 10 with a simple mechanism, and the same effect as in the first embodiment can be obtained.

As shown in FIGS. 6 and 7, a horizontal through hole 40 is provided in the handle horizontal portion 23a in a direction orthogonal to the handle portion 23b, and a pin 41 having both ends expanded in the through hole 40 is provided. The spring member 4 is slidably provided between the pin 41 and the handle horizontal portion 23a.
A similar effect can be obtained even when the cleaner body 22 is pressed against the heating roller 12 by the spring member 42 and the pin 41 with the mounting member 2.

(Effects of the Invention) As is apparent from the above description, according to the present invention, the cleaner can be attached to and detached from the fixing device main body by a simple structure including the cleaner side cam portion and the first spring member on the fixing device main body side. Cost and size can be reduced.

Further, according to the second aspect of the invention, the cleaner can be attached to and detached from the fixing device main body by a simple configuration in which a rotatable handle portion having a cam portion is provided on the cleaner side and a locking portion of the handle portion is provided on the fixing device main body side. Therefore, the same effect as the first invention can be obtained in the second invention.

Further, according to the first and second aspects of the present invention, the cleaner is pressed against the fixing roller regardless of the jam processing of the apparatus, so that the cleaner can sufficiently function as a cleaner even during the jam processing.

[Brief description of the drawings]

FIG. 1 is a sectional view of a fixing device according to a first embodiment, FIG. 2 is a diagram for explaining an outline of an image forming operation by an image forming apparatus, and FIG. 3 is a cross section of a fixing device according to a second embodiment. FIG. 4 is a sectional view of the fixing device according to the third embodiment. FIG. 5 is a diagram showing a state in which the cleaner is about to be attached to the fixing device main body in the identification fixing device. FIG. FIG. 7 is a side view of a cleaner according to an example, FIG. 7 is a cross-sectional view of a horizontal portion of a handle of the cleaner according to the modified embodiment, and FIGS. 8 and 9 are views for explaining the prior art. 6 fixing device, 10 fixing device body, 12 heating roller (fixing roller), 20 cleaner, 22 cleaner body, 23 handle portion (handle), 25 cam portion, 32
...... Support spring (first spring member), 33 ... Spring member (second spring member)
Spring member).

Claims (2)

(57) [Claims] A fixing device having a cleaner which is detachably mounted on a fixing device main body and which is pressed by a fixing roller to clean an outer surface of the fixing roller, wherein the cleaner main body or the cleaner main body is pivotally supported. A cam portion is formed on the handle portion, and a first spring member for pressing the cleaner is fixed to the fixing device main body side, and the cleaner positioned between the first spring member and the fixing roller is moved to the cleaner main body or the handle portion. A fixing device wherein the cleaner is attached to a fixing device main body by rotating the cam portion to engage with a spring member. 2. A fixing device having a cleaner which is detachably provided to a fixing device main body and which is pressed by a fixing roller to clean an outer surface of the fixing roller, wherein the cleaner main body is rotatable and vertically movable. And a cam portion for pressing the cleaner body downward through the second spring member by the rotation thereof is provided on the handle portion, and the handle portion is locked to the fixing device body. ,
A fixing device characterized in that the cleaner body is pressed against the fixing roller by the rotation of the handle portion, and the cleaner is attached to the fixing device body.