JPH06266254A - Fixing device - Google Patents

Abstract

PURPOSE:To prevent the breakage of a rib and improve durability by regulating the drift of a film during conveyance with the rib provided at one end section of an endless belt, and pressing the outer periphery of the rib. CONSTITUTION:A rib 3 is provided on the outer periphery of one side end section of a fixing film 2 made of a heat-resistant resin such as polyimide by integral molding, a regulating member 16 to regulate the rib 3 is arranged inside the rib 3 along the outer periphery of a drive roller 4, and it is fixed to a fixing unit frame body. The film 2 is applied with drifting force by exciting means 8, 9 during conveyance, the rib 3 collides with the regulating member 16 to be regulated, and the drift is stopped. The regulating member 16 is fixed so that a regulating member 17 is invariably kept in contact with the outer peripheral face of the rib 3 to prevent the rib 3 from being deformed to be extended toward the outer peripheral face from the inner peripheral face. The deformation of the film 2 from the inner peripheral face toward the outer peripheral face during conveyance is suppressed, and the breakage of the rib 3 can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device used in an image forming apparatus such as a copying machine, an LBP and an electrostatic printer.

[0002]

2. Description of the Related Art Conventionally, as a means for fixing a toner image on a recording paper, Japanese Patent Laid-Open No. 63-313182 proposes a fixing method using a heat-resistant film. Endless film is used and the film is stretched between the rollers and driven by applying tension, so that the film shifts.

On the other hand, there has been proposed a method in which a rib is provided on at least one end of the film and the rib is restricted by a restricting member so as to suppress the deviation.

[0004]

However, in the above-mentioned conventional example, since the inner surface of the rib is restricted by the restriction member, the contact force causes deformation of the rib from the inner peripheral surface to the outer peripheral surface of the rib, and thus the rib itself. There is a defect that breakage or breakage of the joint portion occurs when the rib and the film are adhered.

An object of the present invention is to solve the above problems and to provide a fixing device which operates well.

[0006]

According to the present invention, in the above-mentioned mechanical structure, the outer peripheral surface of the rib is further restricted by a restricting member, so that the deformation of the rib from the inner peripheral surface to the outer peripheral surface is suppressed and a stable deviation is achieved. It is designed to be controlled.

[0007]

【Example】

<Embodiment 1> FIG. 1 shows a cross section of a fixing device according to a first embodiment of the present invention. In the figure, 1 is a heating element, 2 is a fixing film, and polyimide, polyetherimide, PE
PT on one side of 20μ thick film of heat resistant resin such as S
A release layer such as FE is coated. Generally, the total thickness of the film is preferably 50 μm or less. Reference numeral 3 denotes a rib provided on the outer periphery of one side (front side) of the film. Even if integrally formed with the same material as the film, a rib made of another material (for example, urethane rubber or silicon rubber) having good slidability afterwards. It may be formed by bonding or the like.

The fixing film 2 is stretched between the driving roller 4 and the tension roller 5, and together with the heating body 1 forms a film conveying path. Fixing film 2
Is urged by the urging means 8 (9) via the tension roller bearing 6 (7) in the direction of arrow A, thereby being given a tension and conveyed by the drive roller 4 in the direction of arrow B. It Here, the driving roller 4 is provided with a coating layer of silicon rubber or the like on the surface of a cored bar of iron or the like in order to reliably convey the film 2. Reference numeral 10 denotes a pressure roller having a rubber elastic layer having a good releasing property such as silicon rubber, and the film 2 is applied with a force necessary for fixing.
To the heating element 1. Both ends of the pressure roller 10 are supported by bearings (not shown) so as to rotate following the film 2. The heating element 1 is fixed on a stay 12 having rigidity to withstand the applied pressure via a heat insulating member 11 made of a heat resistant resin. In addition, 13 is an entrance guide, 1
4 is a separation guide, and 15 is a paper discharge roller.

FIG. 2 is a view of FIG. 1 viewed from the J direction,
The regulating member 16 for regulating the rib 3 is the driving roller 4
Is arranged inside the rib 3 (on the center side of the film) along the outer periphery of the fixing unit and is fixed to a fixing device frame (not shown).

The film 2 is constructed so that a biasing force always acts in the direction of arrow C during conveyance by adjusting the biasing force of the biasing means 8 and 9, and the rib 3 collides with the regulating member 16. , It is regulated and the stoppage stops. However, at this time, a contact force is applied to the rib 3 from the regulating member 16 in the D direction, and the rib is directed from the inner peripheral surface to the outer peripheral surface (E direction in the sectional view) like the dotted line portion in FIG. It transforms to extend. In order to hold it down, the second regulation member 17 is always in contact with the regulation member 16 along the outer peripheral surface of the rib 3.
It is fixed to. At this time, the first regulating member 16 and the second regulating member 16
It is desirable that at least the surface of the restriction member 17 that slides on the ribs is made of a material having good slidability, such as polyacetal or fluororesin.

In the above structure, the transfer paper not shown is
2 is fed between the film 2 and the pressure roller 10 through the entrance guide 13 of FIG. 2, and the toner image on the transfer paper is heated and melted by the heat and pressure of the heating body 1 and the pressure roller 10, and is transferred onto the transfer paper. After being fixed, the paper passes through the separation guide 14 and is discharged to the outside of the apparatus by the paper discharge roller 15.

As described above, when the rib provided on one end of the endless film is regulated from the inside by the regulating member, the outer peripheral surface of the rib is further regulated by the second regulating member 17 to convey the film. It is possible to suppress the deformation of the inner rib from the inner peripheral surface to the outer peripheral surface, and to prevent the damage of the rib, the peeling of the bonded portion when the rib and the film are bonded or the damage in the case of one-body molding. It is possible and durability is improved.

<Second Embodiment> FIGS. 4 and 5 show a fixing device according to a second embodiment of the present invention. 4 is a cross-sectional view, and FIG. 5 is a view of FIG. 4 viewed from the K direction. The same members as those in the first embodiment are designated by the same reference numerals.

In the figure, reference numeral 18 is a regulating member, which is arranged inside the rib 3 (on the center side of the film) along the outer periphery of the driving roller 4 and is fixed to a fixing frame body (not shown).

Reference numeral 19 is a rotation restricting member which is driven by the outer peripheral surface of the rib 3 and rotates by a fixed shaft 20.
It is fixed to.

By adjusting the urging force of the urging means 8 and 9, the film 2 is always biased downward during conveyance,
Although it is configured to work, the regulating member 18 always regulates the inner surface of the rib 3, so that the deviation is stopped.

At this time, however, the regulating member 18 is attached to the rib 3.
Since the rib receives a reaction force in the direction perpendicular to the regulation surface, the rib deforms so as to extend in the direction from the inner peripheral surface to the outer peripheral surface, but the rotation regulation member 19 fixed to the regulation member 16 does not move. By regulating the outer peripheral surface while always rotating the driven surface, the sliding resistance is small, and the deformation of the rib from the inner peripheral surface to the outer peripheral surface can be suppressed without applying an excessive force to the rib 3.

At this time, at least the surface of the regulating member 18 that slides on the ribs is preferably made of a material such as polyacetal or fluororesin having good slidability.

As described above, the rib provided at one end of the endless film is regulated from the inside by the regulating member, and the outer peripheral surface of the rib is further regulated by the rotation regulating member, so that the sliding resistance is sometimes low. Thus, it is possible to suppress the deformation of the rib from the inner peripheral surface toward the outer peripheral surface during the film conveyance. Therefore, unreasonable force is applied to the rib outer peripheral surface (sliding resistance of the rib outer peripheral surface).
Since it does not need to be applied, it is possible to prevent breakage of the rib and peeling of the adhesive portion when the rib and the film are adhered, and further improve the durability of the rib.

<Third Embodiment> FIGS. 6 and 7 show a fixing device according to a third embodiment of the present invention. 6 is a cross-sectional view, and FIG. 7 is a view of FIG. 6 viewed from the L direction. The same members as those in the first embodiment are designated by the same reference numerals.

Also in this example, the regulating member 18 is the drive roller 4
Is arranged inside the rib 3 (on the center side of the film) along the outer periphery of the film, and is fixed to a fixing frame body (not shown). A biasing force acts in the direction, the rib 3 receives a contact force from the regulating member 18 in the direction perpendicular to the regulating surface, and the rib 3 deforms from the inner peripheral surface to the outer peripheral surface.

However, since it is fixed to a fixing frame (not shown),
The elastic leaf spring restricting member 21 restricts the outer peripheral surface of the rib 3 along the outer peripheral surface of the drive roller 4 so as to be in contact with the outer peripheral surface of the rib 3 at all times. The deformation of the ribs can be suppressed without applying excessive force.

At this time, the regulating member 22 and the leaf spring regulating member 21
At least the surfaces that slide with the ribs must have good slidability, the regulating member 16 is a material such as polyacetal or fluororesin, and the leaf spring regulating member is a metal material having a surface coated with fluorine or the like. Is desirable.

As described above, when the rib provided at one end of the endless film is regulated from the inside thereof, the outer peripheral surface of the rib is further regulated by the elastic leaf spring regulating member so that the film is being conveyed. Absorbs the flare of the rib outer surface,
By suppressing the deformation of the ribs from the inner peripheral surface to the outer peripheral surface without applying excessive force to the ribs, it is possible to prevent damage to the ribs or peeling of the adhesive part when the ribs and the film are adhered. The durability is further improved.

<Fourth Embodiment> FIG. 8 shows a fourth embodiment of the present invention.

FIG. 8 is a cross-sectional view of the film shift restricting portion. The same members as those in the first embodiment are designated by the same reference numerals.

In the figure, reference numeral 4 denotes a rib provided on the outer periphery of one side (front side) of the film. For the purpose of improving durability against breakage of the rib or peeling on the adhesive surface when adhered to the film. In addition, the stepped rib 4 has a convex cross section.

Reference numeral 23 denotes a regulating member, which is arranged inside the stepped rib 4 (on the center side of the film) along the outer periphery of the driving roller 4, and the inner side surface of the upper step portion of the rib is used as a regulating surface, and a fixing frame body (not shown) is provided. It is fixed to. Reference numeral 24 is a first rotation restricting member that is driven to rotate with the outer peripheral surface of the upper step portion of the stepped rib 4, and 25 is a second rotation restricting member that is driven to rotate with the outer peripheral surface of the lower step portion of the stepped rib 4. Fixed shaft 27,
It is fixed to the regulating member 23 via 28.

In the film deviation regulation as described above,
When the stepped rib 4 is used to improve the durability of the rib,
When the rib receives a contact force from the regulating member 23 in a direction perpendicular to the regulating surface (N direction), both the upper step portion and the lower step portion of the rib extend from the inner peripheral surface toward the outer peripheral surface (M direction). Because of the deformation, the first rotation regulating member 24 and the second rotation regulating member 25 regulate the outer peripheral surfaces of the upper and lower portions while being driven to rotate, thereby reducing the sliding resistance and reducing the inner peripheral surface. The deformation of the ribs 4 from the outer peripheral surface to the outer peripheral surface can be reliably suppressed. However, at this time, at least the surface of the regulating member 23 that slides on the rib 4 is preferably made of a material such as polyacetal or fluororesin having good slidability.

With the above operation, when the rib provided on one end of the endless film is changed to the stepped rib 4 to improve durability, the rib itself is damaged or peeled off at the bonded portion between the rib and the film. Durability is further improved.

[0031]

As described above, according to the present invention, when the member for regulating the deviation force is arranged on the side surface of the rib, the second regulating member is further set along the outer peripheral surface of the rib. By this, it is possible to suppress the deformation of the ribs from the inner peripheral surface to the outer peripheral surface when the endless film rotates, prevent damage to the ribs and peeling at the bonded part in the case of rib and film bonding, and durability It also has the effect of significantly improving the sex.

[Brief description of drawings]

FIG. 1 is a sectional view of a fixing device embodying the present invention.

2 is a top right view of FIG.

FIG. 3 is an enlarged view of FIG.

FIG. 4 is a sectional view of a fixing device according to a second embodiment of the present invention.

5 is a top right view of FIG.

FIG. 6 is a sectional view of a fixing device according to a third embodiment of the present invention.

7 is a top right view of FIG.

FIG. 8 is an enlarged view of a film control unit according to a fourth embodiment.

[Explanation of Codes] 1 ... Heater 2 ... Fixing endless film 3 ... Ribs provided at the end of film 4 ... Driving roller 5 ... Tension roller 6, 7 ... Tension roller bearing 8, 9 ... Film tension urging means 10 ... Pressure roller 11 ... Insulation member 12 ... Stay 16, 18, 2
2, 23 ... Restricting member 17 ... Second restricting member 19 ... Rotation restricting member 20 ... Rotating restricting member 19 is axially supported 21 ... Leaf spring restricting member 24 ... First rotation restricting member 25 ... Second rotation restricting member 26 ... Stepped ribs 27 ... 24 shafts supporting the shafts 28 ... 25 shafts supporting the shafts

Claims (2)

[Claims] 1. An apparatus for heating and fusing a toner image through a durable endless belt to fix the toner image, wherein the endless belt has a rib on at least one end thereof, and a rib is provided on a side during film conveyance. In the fixing device for performing the deviation control by restricting the side surface of the rib with a restricting member, a restricting member that further presses the outer peripheral surface of the rib is provided. 2. The fixing device according to claim 1, wherein the rib has a stepped structure, and a member for pressing not only the outer peripheral surface of the upper step but also the outer peripheral surface of the lower step is provided.