JP2002148972A - Fixing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a belt supporting member to be easily disassembled, assembled and miniaturized for a fixing device with a heating roll, a pressure belt to come in pressurized contact therewith and the belt supporting member to rotatably support the pressure belt. SOLUTION: The fixing device is provided with a belt supporting frame 7 constituted by coupling a first plate member 8 folded so as to form three walls 8a, 8b, 8c among an upstream wall 8b, a downstream wall 8c, an upper wall 9 and a lower wall 8a with a tabular plate member 9 to form one remaining wall 9, a fixing pad 21 made of elastic materials to be supported by the belt supporting frame 7 and to pressurize the rear surface of the pressure belt FP toward the heating roll Fh, an upstream side guide belt 12 and a downstream side guide belt 13 to be attachably/detachably mounted on the upstream wall 8b and the downstream wall 8c, respectively and to guide an inner surface of the heat belt FP and belt supporting members (5 to 22) to rotatably support the heating belt FP.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device for fixing a toner image formed on a recording sheet in an image forming apparatus. The present invention also relates to a fixing device for fixing toner on a recording sheet passing through a fixing area which is a pressure contact area.

[0002]

2. Description of the Related Art Techniques described in the following publications (J01) and (J02) are conventionally known as a fixing device of an image forming apparatus. (J01) JP-A-6-19344 discloses a fixing device having a configuration in which a heater inside an endless belt is pressurized by a pressure roll and toner is fixed by a pressure contact portion. In this fixing device, the mechanism for pressing the pressure roll is composed of a separate component from the belt supporting member that supports the endless belt.
There is also a problem that the belt support member cannot be easily manufactured and disassembled. (J02) Japanese Patent Application Laid-Open No. 10-20691 In this publication, the guide for restricting the movement of the belt in the axial direction is simplified, but the pressure mechanism and the belt circumferential direction regulating member are separately configured. Therefore, the structure becomes complicated,
The number of parts increases, and it is difficult to reduce cost and size.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object the contents described in (O01) below. (O01) In a fixing device including a heating roll, a pressing belt pressed against the heating roller, and a belt supporting member rotatably supporting the pressing belt, a belt supporting member which is easy to disassemble, assemble, and easy to miniaturize. To provide.

[0004]

Next, the present invention devised to solve the above-mentioned problems will be described. The elements of the present invention facilitate the correspondence with the elements of the embodiments described later. For this reason, the components of the embodiment that are denoted by parentheses are added. The reason why the present invention is described in correspondence with the reference numerals of the embodiments described below is to facilitate understanding of the present invention, and not to limit the scope of the present invention to the embodiments.

(1st invention) In order to solve the aforementioned problem,
The fixing device according to the first invention has the following constitutional requirements (A01) to (A0).
5). (A01) A fixing area (Q5) is formed by areas that are in pressure contact with each other, and a heating roll (Fh) and an endless roller that rotate in the recording sheet transport direction while sandwiching the recording sheet (S) that has entered the fixing area (Q5). Pressure belt (Fp),
(A02) An upstream wall (8b) arranged along the belt width direction inside the endless pressure belt (Fp) and arranged upstream in the sheet conveyance direction, and the upstream wall (8).
b) a pair of side walls (8b, 8c) having a downstream wall (8c) disposed opposite to the downstream side, and an upper wall (9) and a lower wall connecting the pair of side walls (8b, 8c). A cylindrical belt support frame (7) having a wall (8a)
A fixing pad (21) supported by the belt support frame (7) and pressing the back surface of the pressure belt (Fp) toward a heating roll (Fh); and the upstream wall (8b).
And an upstream belt guide (1) mounted on the downstream wall (8c) and guiding the inner peripheral surface of the pressure belt (Fp).
2) and a downstream belt guide (13), a belt supporting member (5-22) rotatably supporting the pressure belt (Fp), (A03) the cylindrical belt supporting frame (7). , And movably supported by moving member support frames (1, 2) arranged adjacent to both ends in the width direction of the pressure belt (Fp), and the pressure belt (Fp) is A pair of moving members (3, 4), (A04) that can move between a pressing position for pressing against the heating roll (Fh) and a separating position for separating the pressing belt (Fp) from the heating roll (Fh); Guide mounting part (8b
1, 8c2) provided with the pair of side walls (8
(b, 8c), (A05) Mounted portions (12a, 13a) which are detachably mounted on the guide mounting portions (8b1, 8c2) of the upstream wall (8b) and the downstream wall (8c) are provided. A pair of belt guides (12, 13) constituted by an upstream belt guide (12) and a downstream belt guide (13).

(Operation of the First Invention) In the fixing device of the first invention having the above-mentioned constitutional requirements, the fixing device is disposed inside the endless pressure belt (Fp) along the belt width direction and upstream in the sheet conveying direction. A pair of side walls (8b, 8) having an upstream wall (8b) arranged on the side and a downstream wall (8c) arranged facing the upstream wall (8b) on the downstream side thereof.
c) and a cylindrical belt support frame (7) having an upper wall (9) and a lower wall (8a) connecting the pair of side walls (8b, 8c) are composed of a fixing pad (21) and a high rigidity pad (22). ), Supporting the upstream belt guide (12) and the downstream belt guide (22). The belt support frame (7), the fixing pad (21), the upstream belt guide (12), and the downstream belt guide (22) rotatably support the pressure belt (Fp). The fixing pad (21) made of the elastic material presses the back surface of the pressure belt (Fp) toward the heating roll (Fh).

[0007] The moving member supporting frames (1, 1) arranged adjacent to both ends in the width direction of the pressure belt (Fp), respectively.
2) a pair of movable members (3,
4) supporting the cylindrical belt support frame (7), and pressing the pressure belt (Fp) to the heating roll (Fh).
The pressing belt (Fp) is moved between a pressing position where the pressing belt (Fp) is pressed and a separating position where the pressing belt (Fp) is separated from the heating roll (Fh). The pressure belt (Fp) moved to the pressure contact position conveys the recording sheet (S) having entered the fixing area (Q5) formed by the pressure contact area with the heating roll (Fh) while rotating while nipping the recording sheet (S). The toner image on the sheet (S) is fixed.

Attached portions (12a, 13a) provided on an upstream belt guide (12) and a downstream belt guide (13) constituting a pair of belt guides (12, 13).
Are a pair of side walls (8) of the belt support frame (7).
Guide mounting parts (8b1, 8c2) provided in (b, 8c)
Removably attached to. Therefore, the work of attaching and detaching the pair of belt guides (12, 13) to and from the side walls (8b, 8c) of the belt support frame (7) can be easily performed.

(Embodiment 1) Embodiment 1 of the fixing device of the present invention is characterized in that the fixing device of the present invention is provided with the following constituent element (A06). (A06) Projecting members (12a, 1) each having one through hole (8b1, 8c2) and the other penetrating through the through hole (8b1, 8c2).
3a) the guide mounting portions (8b1, 8)
c2) and the mounted parts (12a, 13a). (Operation of the First Embodiment) In the first embodiment of the fixing device of the present invention having the above-described configuration, the guide mounting portion (8b1,
8c2) and the mounted portions (12a, 13a) are formed by projecting members (12a, 13a), one of which is formed by a through hole (8b1, 8c2) and the other of which is penetrated through the through hole (8b1, 8c2). Since it is formed, it can be easily manufactured.

(Second Embodiment) A second embodiment of the fixing device according to the present invention is characterized in that the first embodiment of the present invention has the following configuration requirement (A07). (A07) When the belt is moved in the belt width direction while penetrating the through holes (8b1, 8c2), the side walls (8b, 8c2,
8c) The protruding member (12a, 13a) having a back surface contact portion that comes into contact with the back surface of 8c). (Effect of Embodiment 2) In Embodiment 2 of the fixing device of the present invention having the above-described configuration, the protrusion members (12a, 13
a) is the side wall (8b, 8b2, 8c2) when it is moved in the belt width direction while penetrating the through hole (8b1, 8c2).
Since the belt guide (12, 13) has a back surface contact portion that comes into contact with the back surface of 8c), the belt guides (12, 13) can be detachably and securely attached to the side walls (8b, 8c).

(Embodiments) Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to the following embodiments. To facilitate understanding of the following description, in the drawings, the front-rear direction is the X-axis direction, the left-right direction is the Y-axis direction, the up-down direction is the Z-axis direction, and arrows X, -X, Y, -Y, The directions indicated by Z, -Z or the sides indicated are forward, rearward, rightward, leftward, upward, downward,
Or, the front side, the rear side, the right side, the left side, the upper side, and the lower side.
Also, in the figure, those with “•” in “○” mean arrows pointing from the back of the paper to the front, and those with “x” in “○” indicate the arrow on the paper. From the back to the back.

(Embodiment 1) FIG. 1 is an explanatory view of a color image forming apparatus having a fixing device provided with a fixing device according to Embodiment 1 of the present invention. In FIG. 1, an image forming apparatus U includes an automatic document feeder U1 and a platen glass PG supporting the same.
And an image forming apparatus main body (copier) U2 having The automatic document feeder U1 includes a document feed tray TG1 on which a plurality of documents Gi to be copied are placed in a stack.
And the platen glass PG from the document feed tray TG1.
A document discharge tray TG2 from which the document Gi conveyed through the upper copy position (document reading position) is discharged. The image forming apparatus main body U2 includes a UI (user interface) through which a user inputs an operation command signal such as a copy start signal, an exposure optical system A, and the like. Reflected light from a document conveyed on the platen glass PG by the automatic document feeder U1 or a document (not shown) manually placed on the platen glass PG is transmitted through the exposure optical system A to the CCD (CCD). R (red), G (green), B
(Blue) electrical signal. The IPS (image processing system) converts the RGB electrical signals into Y signals.
(Yellow), M (magenta), C (cyan), K
The image data is converted into (black) image data, temporarily stored, and output to the laser drive circuit DL at a predetermined timing.

An image carrier PR that rotates and moves in the direction of the arrow Ya.
Is uniformly charged by the charging roll CR, and sequentially passes through the latent image writing position Q1, the developing area Q2, and the primary transfer area Q3. An ROS (latent image writing device) driven by the laser driving circuit DL performs exposure scanning with the laser beam L at the latent image writing position Q1 to form an electrostatic latent image on the surface of the image carrier PR. When a full-color image is formed, electrostatic latent images corresponding to four color images of Y (yellow), M (magenta), C (cyan), and K (black) are sequentially formed. Only the electrostatic latent image corresponding to the (black) image is formed.

The rotary type developing device G is rotated Y in the developing area Q2 in accordance with the rotation of the rotating shaft Ga.
(Yellow), M (magenta), C (cyan), K
It has developing units GY, GM, GC, and GK for four colors (black). Each of the developing units GY, GM, GC, and GK has a developing roll GR for transporting a developer to the developing area Q2, and forms an electrostatic latent image on the image carrier PR passing through the developing area Q2. Develop into a toner image Tn.

Below the image carrier PR, a slide frame F1 is provided by a pair of left and right slide rails SR, SR.
(Indicated by a two-dot chain line) is supported so as to be slidable back and forth (in a direction perpendicular to the paper surface). Slide frame F1
Supports a belt frame F2 of the belt module BM so as to be rotatable up and down around a hinge axis F2a. The belt module BM includes a plurality of belt support rolls (Rd, Rd,
Rt, Rf, T2a), a primary transfer roll T1, a contact roll T2c, and the belt frame F2 supporting them. The plurality of belt support rolls (Rd, Rt, Rf, T2a) include a belt drive roll Rd, a tension roll Rt, an idler roll (free roll) Rf, and a backup roll T2a,
The backup roll T2a has the contact roll T
2c is in contact.

The belt module BM is rotatable up and down around the hinge axis F2a. When the belt module BM is rotated downward, the belt module BM does not come into frictional contact with the image carrier PR together with the slide frame F1 to form an image. Device body U
2 can go in and out. To the primary transfer device T1, a transfer voltage having a polarity opposite to the polarity of the charged toner is applied by a power supply circuit E controlled by a controller C.
The toner image Tn on the front surface is primarily transferred to the intermediate transfer belt B in the primary transfer area Q3. For full color images,
Toner images Tn of each color sequentially formed on the surface of image carrier PR
Are sequentially superimposed on the surface of the intermediate transfer belt B in the primary transfer area Q3, and a full-color multiple toner image is finally formed on the intermediate transfer belt B. When a single-color mono-color image is formed, only one developing unit is used, and a single-color toner image is primarily transferred onto the intermediate transfer belt B. After the primary transfer, the surface of the image carrier PR is cleaned of residual toner by the image carrier cleaner CLp, and is discharged by the discharging roller JR.

Below the backup roll T2a, a secondary transfer slide frame Fs slidable forward and backward (in a direction perpendicular to the paper surface) by a pair of left and right slide rails SR, SR with respect to the image forming apparatus main body U2. It is supported detachably. A secondary transfer lifting frame Ft of the secondary transfer unit Ut is supported on the secondary transfer slide frame Fs so as to be rotatable up and down around a hinge axis Fta. When the secondary transfer unit Ut is rotated downward, the secondary transfer unit Ut does not come into frictional contact with the belt module BM.
The user can enter and exit the image forming apparatus main body U2. 2 above
The secondary transfer unit Ut includes a secondary transfer roll T2b, a secondary transfer roll cleaner CLt, a roll support lever Lr,
Sheet guide SG2 after transfer and sheet transport belt BH
And the secondary transfer elevating frame Ft supporting them.
And

The roll support lever Lr is a lever that supports the secondary transfer roll T2b and the secondary transfer roll cleaner CLt. The roll support lever Lr is rotated around a hinge axis La by a motor (not shown) to rotate the secondary transfer roll T2b. The intermediate transfer belt B is moved between a secondary transfer position in contact with the intermediate transfer belt B and a standby position separated from the intermediate transfer belt B. A secondary transfer area Q4 is formed by the contact area between the secondary transfer roll T2b and the intermediate transfer belt B, and a secondary transfer unit T2 is formed by the secondary transfer roll T2b, the backup roll T2a, and the contact roll T2c. I have.

The recording sheets S stored in the paper feed tray TR1 are taken out by a pickup roll Rp at a predetermined timing, separated one by one by a separation roll Rs, and conveyed to a registration roll Rr. The cashier roll Rr
The recording sheet S conveyed to the pre-transfer sheet guide S is timed to move the primary-transferred multi-toner image or single-color toner image to the secondary transfer area Q4.
The sheet is conveyed from G1 to the secondary transfer area Q4. When the recording sheet S passes through the secondary transfer area Q4, a secondary transfer voltage having the same polarity as the toner charging polarity is applied to the contact roll T2c of the secondary transfer unit T2 from the power supply circuit E controlled by the controller C. Is done. The secondary transfer unit T2 collectively transfers the color toner image primarily transferred onto the intermediate transfer belt B onto the recording sheet S in the secondary transfer area Q4.
Next transfer. The residual toner is removed from the intermediate transfer belt B after the secondary transfer by the belt cleaner CLb. Further, the secondary transfer roll T2b is a secondary transfer roll cleaner CLt.
As a result, the toner adhered to the surface is collected.

The secondary transfer roller T2b and the belt cleaner CLb are disposed so as to be able to freely contact (separate and contact) with the intermediate transfer belt B, and when a color image is formed, the final color is not determined. It is separated from the intermediate transfer belt B until the applied toner image is primarily transferred to the intermediate transfer belt B. The secondary transfer roll cleaner CLt
Performs the separation / contact movement together with the secondary transfer roll T2b. The recording sheet S on which the toner image has been secondarily transferred is conveyed to the fixing area Q5 by the post-transfer sheet guide SG2 and the sheet conveying belt BH. The fixing area Q5 is an area formed by the pressure contact area between the heating roll Fh and the pressure belt Fp. The recording sheet S is heated and fixed by a fixing device F having the heating roll Fh and the pressure belt Fp when passing through the fixing area Q5. The recording sheet S on which the toner image has been fixed is placed on a recording sheet discharge tray TR2.
Is discharged. The codes Rp, Rs, Rr, SG1, S
The sheet conveying device SH is constituted by the elements indicated by G2 and BH.

(Fixing Apparatus) FIG. 2 is an overall explanatory view of the fixing apparatus shown in FIG. 1 and is a perspective view. FIG. 3 is an explanatory view of a main part of a section taken along line III-III of FIG. 2 (or a sectional view taken along line III-III of FIG. 9).
FIG. 3 is a diagram illustrating a state in which a pressure belt is in pressure contact with a heating roll. FIG. 4 is an explanatory view of a main part of a cross section taken along the line IV-IV in FIG. 2 (or a cross-sectional view taken along the line IV-IV in FIG. 9B), and is a view showing a state where the pressing belt is separated from the heating roll. FIG.
FIG. 9B is an explanatory view of a main part of a cross section taken along line VV of FIG. 2 (or FIG. 9B).
FIG. 5 is a diagram showing a state in which the pressure belt is pressed against the heating roll and the sheet peeling member is held at the fixing operation position. FIG. 6 is an explanatory view of a main part of a cross section taken along line VI-VI in FIG. 2 (or a sectional view taken along line VI-VI in FIG. 9B), in which a pressure belt is pressed against a heating roll and a sheet peeling member is separated from the surface of the fixing roll. FIG. 6 is a diagram showing a state where the camera is held at a separated position.

2 to 6, a fixing device F includes a front plate 1 and a rear plate 2 as a pair of lever supporting frames (moving member supporting frames), a connecting member T1 connecting upper portions thereof, and a connecting member T1 thereof. It has a connecting member T2 and the like (not shown) for connecting the lower left portions. The front plate 1 and the rear plate 2 connected by the connecting members T1, T2 and the like are detachably fixed to a fixed frame (not shown) of the image forming apparatus U. A heating roll Fh is rotatably supported by the front plate 1 and the rear plate 2, and a rotating force is transmitted to a rear end of the heating roll Fh by a motor and a rotating force transmitting member (not shown). I have.

FIG. 7 is a plan view of the front plate 1 and the rear plate 2 and rotating levers 3 and 4 as moving members supported on the inner surfaces thereof. 2, 3, and 7
, The front plate 1 and the rear plate 2 are provided with rod connecting portions 1a, 2a bent at right angles at their upper ends, and the lever supporting shafts 1b, 1b, 2b is provided.
FIG. 8 is a perspective view of the rotating levers 3 and 4. 7 and 8, a rotating lever 3 rotatably supported by a lever support shaft 1b is formed by bending a metal plate, and includes a pin fitting portion 3a, a rod penetrating portion 3b, and a pair of guide edges. 3
end mounting member insertion groove 3c formed by c1, 3c1,
It has a locking member 3d and an interval holding portion 3e. The width D of the rod penetrating portion 3b and the interval holding portion 3e in the X-axis direction (see FIG. 7) are the same, and as shown by a two-dot chain line in FIG. When supported by the rod connecting portion 1a in a fitted state and in contact with the inner surface of the front plate 1, the side surface of the rotating lever 3 and the side surface of the front plate 1 are configured to be parallel. The rotation lever 4 rotatably supported by the lever support shaft 2b is also configured in the same manner as the rotation lever 3, and includes the same elements 4a to 4e as the elements indicated by the reference numerals 3a to 3e.
4e.

FIG. 9 is an explanatory view of a belt supporting member supported by the rotating lever and a pressing belt rotatably supported by the belt supporting member. FIG. 9A is a plan view, and FIG. 9B is IXB of FIG. 9A. It is a IXB line sectional view. FIG.
Is a plan view of the pressure belt Fp on the right side of the pressure belt Fp (Y
9A is a plan view of the pressing belt Fp, and FIG. 9A is a view of the pressing belt Fp viewed from the left (−Y side) position. FIG. 10 is an exploded view of the member shown in FIG. 9B. FIG. 11 is a sectional view of a main part of FIG. 9B, FIG. 11A is a sectional view taken along line XIA-XIA of FIG. 9B, and FIG.
FIG. 6B is a sectional view taken along line XIB-XIB of FIG. FIG.
3 is an exploded view of the member shown in FIG.

FIG. 13 is an explanatory view of an end mounting member mounted on the front end of the belt support frame and supported by the front rotating lever 3, and FIG. 13A is a perspective view of the end mounting member.
13B is a front view of the end mounting member, FIG. 13C is a top view of the end mounting member, and FIG. 13D is a rear view of the end mounting member. FIG. 14 is an explanatory view of the end mounting member shown in FIG. 13, and FIG. 14A is a side sectional view showing XIVA-X of FIG. 13B.
FIG. 14B is a cross-sectional view taken along a line VIA, FIG. 14B is a cross-sectional view taken along a line XIVB-XIVB in FIG. 13B, and FIG. 14C is a cross-sectional view taken along a line XIVC-XIVC in FIG. FIG.
In FIG. 10, the front end mounting member 5 and the rear end mounting member 6 are respectively rotated by the rotating levers 3 and 4.
Is supported. Since the end mounting members 5 and 6 are configured symmetrically, the front end mounting member 5 will be described with reference to FIGS.

In FIG. 13 and FIG.
Are a pair of parallel guide edges 3c1, 3c1 of the end mounting member insertion groove 3c of the rotating lever 3 (see FIGS. 7 and 8).
A pair of guided grooves 5a, 5a guided by the shaft and a locked hole (locked portion) 5b locked by the locking member 3d (see FIGS. 7 and 8) (see FIGS. 14A and 14B). ), And is supported in a predetermined posture by the rotating lever 3 when the rotating lever 3 is inserted into the end mounting member insertion groove 3c. The end mounting member 5 has a frame insertion hole 5c on the rear end surface (-X end surface) side into which a front end portion of a belt support frame 7 described later is inserted.
A frame positioning recess 5c1 is formed at the upper right side of c.

The end mounting member 5 includes a pressure belt Fp.
It has a belt outer end position regulating surface 5d for regulating the position of the end in the belt width direction and a belt end guide surface 5e formed by a partial cylindrical surface for guiding the inner peripheral surface of the pressure belt end. A plurality of grooves 5e1 (see FIGS. 13C, 14A and 14B) are formed on the belt end guide surface 5e along the rotation direction. The belt outer end position regulating surface 5d is formed to be rough like a file surface, and when the pressure belt Fp rotates, it comes into frictional contact with the width direction end surface of the pressure belt Fp and the width direction end surface of the pressure belt Fp. Are configured to wear. Accordingly, since the widthwise end surface of the pressure belt Fp is worn during frictional contact with the belt outer end position regulating surface 5d during rotation, the position of the widthwise end surface of the pressure belt Fp gradually moves in the width direction. For this reason, the pressing belt F
p, the position of the edge of the recording sheet S in the width direction gradually moves, so that the pressure belt F by the edge of the recording sheet S
The wear of p can be prevented. The belt end guide surface 5e is formed in a tapered shape whose inner end has a small diameter, so that the endless pressure belt Fp can be easily inserted into the end.

On the front end surface (X end surface) of the end mounting member 5,
The spacing maintaining projections 5f1 and 5f2 are provided so as to project in the X-axis direction, and the distance D between the front end surfaces of the spacing maintaining projections 5f1 and 5f2 and the front wall of the guided groove 5a (see FIG. 14B) is 7 is the same as the width D in the X-axis direction of the rod penetrating part 3b and the spacing part 3e shown in FIG. In this way, by making the distance D and the width D the same, as shown in FIG. 9, the front end surfaces of the interval maintaining projections 5f1, 5f2, the rod penetrating portion 3b
In addition, the front end of the space holding portion 3e can be arranged close to the space holding portion 3e. In this case, as can be seen from FIG. 9B, the rotation lever 3 can be prevented from falling down (tilting), and the rotation lever 3 can be held substantially parallel to the front plate 1.

The end mounting member 6 (see FIGS. 9 and 10) mounted on the rear end of the belt support frame 7 is the same as the end mounting member 5 (see FIGS. 13 and 14) mounted on the front end. The end mounting member 5 has a symmetrical configuration.
It has elements 6a to 6f2 similar to the elements indicated by a to 5f2.

FIG. 15 is an explanatory view of the belt support frame.
15A is a plan view, and FIG. 15B is an arrow XV in FIG. 15A.
FIG. 15C is a view from the arrow XVC of FIG. 15A. FIG. 16 is an enlarged view of a main part of FIG.
FIG. 16A is a diagram showing the shape of the plate 9 at the portion indicated by the arrow XVIA in FIG. 15A, and FIG. 16B is a diagram showing the shape of the upstream wall 8b of the frame main body at the portion indicated by the arrow XVIB in FIG. 16A. FIG. 17 is a cross-sectional view of a main part of FIG. 15A, FIG. 17A is a view as viewed from an arrow XVIIA of FIG. 15A, FIG. 17B is a cross-sectional view of the XVIIB-XVIIB line of FIG. 15A, and FIG. 17D is a sectional view taken along the line XVIID, and FIG. 17D is a sectional view taken along the line XVIID-XVIID in FIG.
17E is a sectional view taken along the line XVIIE-XVII in FIG. 15A.
FIG. 17F is a sectional view taken along the line E of FIG.
It is IIF line sectional drawing. 9 to 12 and 15,
Inside the thin-film endless pressure belt Fp (see FIG. 11), the width direction of the pressure belt Fp (the heating roll Fh
The belt support frame 7 extending in the axial direction of FIG. 11, 12, and 17, the belt support frame 7 includes a metal frame body 8 having a J-shaped cross section and a plate 9 welded to the frame body 8.

The frame body 8 having the J-shaped cross section is bent 90 ° at both ends thereof so as to be opposed to each other at both ends thereof in a cross-sectional view perpendicular to the longitudinal direction (see FIGS. 11 and 12). It has an arranged upstream wall (sidewall arranged on the upstream side in the sheet conveyance direction) 8b and a downstream wall (sidewall arranged on the downstream side in the sheet conveyance direction) 8c.
Lower wall 8a, upstream wall 8b, downstream wall 8 of frame body 8
c and the upper wall 9 formed by the plate 9 constitute a cylindrical belt support frame 7. The downstream wall 8c is formed to be longer than the upstream wall 8b, and the tip portion protrudes more toward the heating roll Fh than the tip of the upstream wall 8b. That is, the downstream wall 8c is
8c projecting toward the heating roll Fh from the tip of
Have one. In FIG. 15C, four upstream guide mounting holes (guide mounting portions) 8b1 formed in the upstream wall 8b by through holes for mounting a belt guide (described later) on the upstream side of the fixing area (FIG. 16B, FIG. 17B) and two positioning projections 8b2 (see FIG. 17F) are formed apart in the longitudinal direction. In addition, unevenness (see FIG. 16B) is formed at the upper end (Z end) of the upstream wall 8b.
The plate 9 is configured to be fitted with unevenness (see FIG. 16A) on the left end (−Y end) of the plate 9 described later.

In FIG. 15B, the downstream wall 8c has four downstream guide mounting holes (guide mounting portions) 8c2 (see FIG. 15) formed by through holes for mounting a belt guide (described later) on the downstream side of the fixing area. 15B, see FIG. 17D) are formed apart in the longitudinal direction. The downstream wall 8c has a plurality of fitting projections 9e at the right end (Y end) of the plate 9 described later.
A convex fitting hole 8c3 in which is fitted, two screw holes 8c4,
Two positioning projections 8c5 (see FIG. 17F) are formed. In FIG. 15, a plate 9 welded to the upper end of the frame body 8 has a plurality of through-holes 9a formed along the longitudinal direction and a plurality of pad receiving holes 9b (see FIGS. 10 and 10). 15A), a plurality of leg member mounting grooves 9c, and two leg mounting grooves 9d with engagement holes. One of the two pad receiving holes 9b is formed as a circular hole and the other is formed as an oblong hole, and the two leg mounting grooves 9d with the engaging holes are formed with other plural leg mounting grooves. 9c, but has a slightly longer length in the X-axis direction. The right end edge of the plate 9 has a plurality of fitting projections 9e arranged at intervals along the longitudinal direction.
(See FIG. 16A), and the fitting projection 9e is fitted into the projection fitting hole 8c3 (see FIG. 15B). A high-rigidity rectangular tube having a rectangular cross section is formed by a part of the frame main body 8 having the J-shaped cross section (the portion excluding the protruding portion 8c1) and the plate 9.

The belt supporting frame 7 composed of the frame body 8 and the plate 9 having the J-shaped cross section is attached to each of the rotating levers 3 and 4 supported on the front plate 1 and the rear plate 2 by an end mounting member. 5,
6 are connected. The belt support frame 7 whose longitudinal ends are supported by the rotating levers 3 and 4 moves between a position close to the heating roll Fh and a position separated from the heating roll Fh when the rotating levers 3 and 4 rotate. I do.

On the lower surface of the central portion 8a of the frame main body 8 constituting the belt support frame 7, an oil absorbing member 11 (FIG. 11) formed of felt or the like along its longitudinal direction (axial direction of the heating roll Fh). , See FIG. 12)
Is glued. Belt guides 12 and 13 are attached to the belt support frame 7 on the outer surfaces of the upstream wall 8b and the downstream wall 8c, respectively, along the longitudinal direction.

FIG. 18 is an explanatory view of an upstream belt guide arranged on the upstream side of the fixing area along the rotation direction of the pressure belt Fp. FIG. 18A is a top view, and FIG. 18B is a view from the arrow XVIIIB in FIG. 18A. FIG. 18C is a sectional view taken along the line XVIIIC-XVIIIC of FIG. 18A, and FIG.
B is a cross-sectional view taken along line XVIIID-XVIIID, FIG. 18E is a cross-sectional view of a main part of the state in which the upstream belt guide is being mounted on the belt support frame, and FIG. 18F is a main part of the state in which the upstream belt guide is mounted on the belt support frame. It is sectional drawing. In FIG. 18, the belt guide 12 has four L-shaped projections (attached portions) 12a and two long holes 12b arranged at intervals along the longitudinal direction thereof. As shown in FIG. 18E, the mold projection 12a is formed in the guide mounting hole 8 of the belt support frame 7 (see FIGS. 15 to 17).
b1 and the long holes 12b are fitted into the positioning projections 8b2, and then moved in the longitudinal direction to the state shown in FIG. 18F, so that they can be detachably attached to the outer surface of the upstream wall 8b of the frame body 8. Is done. In FIG. 18, the tip of the L-shaped projection 12a is configured as a back surface contact portion that contacts the back surface of the upstream wall 8b.

The outer surface of the belt guide 12 is formed by a partial cylindrical surface, and a plurality of concave grooves 12c are formed along the circumferential direction of the partial cylindrical surface. This concave groove 12
c is formed to prevent the oil applied to the inner peripheral surface of the pressure belt Fp, which is guided in the circumferential direction of the outer surface of the belt guide 12 and rotates, from moving to the outer end of the belt guide 12. I have.

FIG. 19 is an explanatory view of a downstream belt guide arranged downstream of the fixing area along the rotation direction of the pressure belt Fp. FIG. 19A is a top view, and FIG. 19B is a view from the arrow XIXB in FIG. 19A. FIG. 19C shows XI of FIG. 19B.
It is an XC-XIXC line sectional view. In FIG. 19, the belt guide 13 also has four L-shaped projections (attached portions) 13a, two long holes 13b, and four It has a groove 12c formed on the side surface for preventing oil movement. Then, the L-shaped projection 13a is inserted into the guide mounting hole 8c2 of the belt support frame 7, and the elongated hole 13b is fitted into the positioning projection 8c5, and then moved in the longitudinal direction, whereby the downstream wall 8c of the frame body 8 is moved. Removably mounted on the outer surface of the. Further, the belt guide 13 is formed with two screw head receiving holes 13d (see FIG. 19B) arranged at intervals in the longitudinal direction. A screw N5 (see FIG. 11A) that penetrates through the screw head receiving hole 13d and is screwed into the screw hole 8c4 (see FIG. 15) has its head housed in the screw head receiving hole 13d, and has a tip end portion of the screw N5. Is accommodated in a screw tip accommodation hole 22c formed in a fixing leg member 22b of the high rigidity pad 22 described later.

FIG. 20 shows a pressure belt F passing through the fixing area.
It is explanatory drawing of the low friction sheet arrange | positioned at the back of p. 10 and 20, the low-friction sheet 16 has a plurality of through-holes 16a for the spring housing cylinder and two through-holes 16b for projecting the pad support member along the longitudinal direction. As can be seen from FIGS. 12 and 20, the low friction sheet 1
6 has a plate supported portion 16c supported on the upper surface of the plate 9, and a belt contact portion 16d arranged along the inner peripheral surface of the pressure belt Fp. Are formed with the through holes 16a and 16b.

10 to 12, a spring supporting member 17 is supported on the upper surface of the plate 9 constituting the belt supporting frame 7, and the spring supporting member 17 extends along its longitudinal direction (see FIG. 10). It has a plurality of spring accommodating cylinders 17a and two pad support member mounting holes 17b arranged at intervals. The plurality of spring receiving cylinders 17a
Is formed so as to project downward, and the low friction sheet 1
6 through the through-hole 16a of the cylinder and the through-hole 9a of the cylinder 9 and the belt support frame 7.
(See FIG. 9B). The spring receiving cylinder 17
The depth a is formed deep at both ends in the longitudinal direction of the spring support member 17 and shallow at the center. A pad support member guide surface 17c is formed on the upper end of the spring support member 17.

9B to 12, a plurality of spring accommodating cylinders 17 are arranged along the width direction of the pressure belt Fp.
The same coil springs (pad pressing members) 18 are housed in the insides a, respectively, and a pad receiver 19 is supported on the upper surface of each coil spring 18. The pad receiver 19 has two protrusions 1 spaced apart in the longitudinal direction thereof.
9a (see FIG. 10) are provided, and the protruding portions 19a are provided.
Is inserted into the pad support member mounting hole 17b of the spring support member 17. The pad receiver 19 extends along the width direction of the pressure belt Fp, and a left side surface 19c of the pad receiver 19 (FIG. 1).
1) is vertically guided by the pad support member guide surface 17c.

On the upper surface of the pad receiver 19, an elastic fixing pad 21 is supported. The surface of the fixing pad 21 is subjected to a fluorine coating process (latex process). Since the surface of the fixing pad 21 that has been subjected to the fluorine coating is coated with a fluorine compound, it is possible to prevent a lubricant such as silicone oil applied or adhered to the back surface of the pressure belt Fp from penetrating into the fixing pad 21.

As described above, the same coil spring 18
Since the spring support member 17 is inserted into the spring accommodating cylinder 17a which is deep at both ends and shallow at the center, the lower surface of the pad receiver 19 supported by the coil spring 18 is smaller than its longitudinal end. And receive great power in the center.
Generally, since both ends of the belt support frame 7 supported by the pressure belt Fp are pressed toward the heating roll Fh, the pressing force at both ends of the fixing area Q5 tends to be larger than that at the center. Pad receiving 19 by 18
By applying a larger force at the center portion than at the end portion in the longitudinal direction, a uniform pressing force can be obtained over the entire area in the longitudinal direction (width direction) of the fixing region Q5.

In FIG. 11, on the right side (Y side) of the pad receiver 19, a hard high-rigidity pad 22 is arranged. FIG. 21 is an explanatory view of the high-rigidity pad 22, and FIG.
21B is a left side view of the high-rigidity pad 22, and FIG.
FIG. 21C is a view from the arrow XXIB of FIG.
XXIC-XXIC sectional view of FIG. 10 to 12, the high-rigidity pad 22 extends in the X-axis direction, and has a plurality of leg members 22a and two fixing leg members 22b extending downward at predetermined intervals in the longitudinal direction on the lower surface thereof. Are provided. Each of the two fixing leg members 22 is formed with a screw tip receiving hole 22c. In FIG. 21, the high-rigidity pad 22 has a lower step 22d and an upper step 22e formed on the left side (−Y side portion). The lower step portion 22 d is provided on the plate 9 of the belt support frame 7.
The upper step portion 22e is a portion in contact with the upper right end of the pad receiver 19. Upper step 22
e is a pad receiver 19 and a fixing pad 2 supported thereon.
Fixing pad movement restricting member 2 for restricting upward movement of fixing pad 1
2e. Further, a flat belt pressing surface 22f is formed on the upper end of the high rigidity pad 22.

In FIG. 21A, a plurality of leg members 22a and two fixing leg members 22b extend below the lower step portion 22d.
A height adjusting portion 22g extending in the longitudinal direction of the high-rigidity pad 22 and having the same thickness as each of the leg members 22a and 22b is provided at the upper portion of the upper portion. As can be seen from FIG. 21A, the height of the height adjusting portion 22g is set higher at the center in the longitudinal direction of the high-rigidity pad 22, and set to zero at both ends in the longitudinal direction. The plurality of leg members 22a and 22b are shown in FIG.
A, The plate 9 is inserted and mounted in the plurality of leg member mounting grooves 9c and two engagement hole-equipped leg mounting grooves 9d of the plate 9 shown in FIG. When the belt pressing surface 22f of the high-rigidity pad 22 is pressed down over the entire length in the longitudinal direction in the mounted state, the high-rigidity pad 22 is moved by the height adjusting portion 22g in the plate 9 along the longitudinal direction. Curved to abut the upper surface of the In this case, the height adjusting portion 22g has a higher height at the center in the longitudinal direction and a lower height toward both ends.

FIG. 5 showing a section taken along line VV of FIG. 9B.
In this case, the pressure belt Fp is pressed against the heating roll Fh, and at this time, the high-rigidity pad 22 is pushed down, and the lower end of the height adjusting portion 22g is placed on the plate 9 of the belt support frame 7.
Is engaged with the upper surface. Also, in FIG. 6 showing a cross section taken along the line VV in FIG. 9B (that is, a cross section taken along the line VI-VI), the pressure belt Fp is separated from the heating roll Fh. The pad spring 19 is moved upward by the coil spring 18 which pushes up the pad receiver 19 abutting on the pad 22e. At this time, the lower end of the height adjusting portion 22g has risen from the upper surface of the plate 9, and at this time, FIG.
A, as shown in FIG.
The lower surface of 2c is engaged with the screw N5, and the rising position of the high-rigidity pad 22 is regulated.

A plurality of leg members 22 of the high rigidity pad 22
a is inserted into the leg member mounting groove 9c of the plate 9, and the two fixing leg members 22b are inserted into the threaded leg portion mounting groove 9d. With this configuration, the high rigidity pad 2
Numeral 2 is supported by a belt support frame 7 (see FIGS. 10 and 15) so as to be able to move up and down and not to move left and right and back and forth. 3 to 7, the right side surface of the high-rigidity pad 22 comes into contact with the inner side surface of the downstream wall 8 c of the frame body 8 having the J-shaped cross section, and is guided vertically by the inner side surface. FIG.
A, a screw N5 fixed to the screw hole 8c4 of the downstream wall 8c of the frame body is inserted into the screw tip receiving hole 22c.
Is inserted. The outer diameter of the screw N5 is smaller than the inner diameter of the pin insertion hole 8, and the high-rigidity pad 22 can move up and down with respect to the frame body by the difference between the diameters (for play). Note that a pin and a pin press-in hole can be used instead of the screw N5 and the screw hole 8c4.

The pad receiver 19 and the fixing pad 21 are pressed against the heating roll Fh by the respective coil springs 18 accommodated in the plurality of spring accommodating cylinders 17a. As shown in FIGS. Pressure belt Fp is heated roll F
h, the respective coil springs 18 are extended and the upper right end of the pad receiver 19 is in contact with the upper step 22e of the high-rigidity pad 22. At this time, the high-rigidity pad 22 is Although it is lifted by the receiver 19, the ascending position is regulated by the screw N5. As shown in FIGS. 3 and 5, when the pressure belt Fp is moved to the pressure contact position where the pressure belt Fp is pressed against the heating roll Fh, the respective coil springs 18 are compressed and the upper right end of the pad receiver 19 is located above the high rigid pad 22. At this time, the high-rigidity pad 22 is moving downward, but the lower end of the height adjusting portion 22g is in contact with the upper surface of the plate 9 and the lowering position is regulated.

In the state shown in FIGS. 3 and 5, the high rigidity pad 22 and the fixing pad 21 press the pressure belt Fp against the heating roll Fh from the back side thereof. Since the high-rigidity pad 22 is formed of a harder material than the heating roll Fh, a portion of the surface of the heating roll Fh pressed by the hard high-rigidity pad 22 is deformed into a concave shape. Due to this deformation, the heating roll Fh and the pressure belt F
The recording sheet S passing through the fixing area Q5 which is the pressure contact area of p is easily peeled off from the surface of the heating roll Fh. The belt support members (5 to 22) are constituted by the elements indicated by the reference numerals 5 to 22 and the like.
The fixing members (Fp, 5-2)
2) is configured.

2 to 6, plate-like rod penetration portions 3b, 4b of the rotary levers 3, 4 rotatably supported by lever support shafts 1b, 2b of the front plate 1 and the rear plate 2. Have rod through holes 3f, 4f through which rods 26 slidably penetrate in the axial direction.
(See FIG. 7). The upper ends of the rods 26, 26 are press-fitted and fixed in rod press-fit holes formed in the rod connecting portions 1a, 2a of the front plate 1 and the rear plate 2. The lower ends of the rods 26, 26 are provided with spring seats 26a.
6a, 26a and the rod penetrating portions 3b of the rotating levers 3, 4;
4b, a compression spring (lever biasing member) 27 is disposed. The rod springs 3b, 4b of the rotary levers 3, 4 are always lifted upward by the compression spring 27.

A rotary operation shaft 29 is rotatably supported by the front plate 1 and the rear plate 2, and an operation handle (lever rotation operation member) 31 (FIG. 2) is provided at the front end of the rotary operation shaft 29. See) has been fixed. Elevating cams 32 for raising and lowering a pressure belt (a pressure rotation member for fixing) Fp are screwed at both ends of the rotary operation shaft 29 at positions adjacent to the inner surface of the front plate 1 or the rear plate 2, respectively. It is fixed by N1. The elements indicated by the reference numerals 29 and 32 constitute lever rotation position adjusting members (29, 32). 5 and 6, a cam 33 for moving a peeling member is provided on the rotation operation shaft 29 inside the lifting cam 32.
2 fixed. The operation handle 31 is shown in FIG.
In this state, the lifting cam 32 is held at the position shown in FIG. 3, and the peeling member moving cam 33 is held at the position shown in FIG. When the operation handle 31 rotates counterclockwise from FIG. 2, the elevating cam 32 rotates from the position shown in FIG. 3 to the position shown in FIG.
From the position shown in FIG. 6 to the position shown in FIG.

2, 5, and 6, a peeling member supporting member 36 rotatably supported by the rotary operation shaft 29.
Has a cross-sectional shape in which U is laid sideways, and has a rotation operation shaft 2
9 has a central portion 36a (see FIG. 2) disposed so as to surround the three directions, and shaft mounting portions 36b and 36b (see FIG. 2) provided at both ends thereof. The shaft mounting portions 36b, 36b
Is rotatably fitted to the rotary operation shaft 29. A guide roll supporting leaf spring 37 and a leaf spring fixing member 38 are fixed to the peeling member supporting member 36 by screws N3. 5 and 6, the guide roll supporting leaf spring 3 is used.
A plurality of guide rolls 39 are rotatably supported at the lower end of 7.

5 and 6, a plurality of nuts 41 are fixed to the lower surface of the lower portion of the central portion 36a of the peeling member supporting member 36 at intervals in the longitudinal direction. A connection bolt 42 is screwed into the nut 41 from below. A nut 43 is screwed to the connection bolt 42 above the bolt head 42a. The release member 44 connected to the lower end of each of the connection bolts 42 includes a sheet-like release member (that is, a release sheet) 45 for releasing the recording sheet S from the surface of the heating roll Fh, and the release sheet 4.
And a plate-shaped elastic release sheet support plate 46 for supporting the support 5. The release sheet support plate 46 is sandwiched between the bolt head 42 a and the nut 43.

The nuts 43 are loosened to connect the connecting bolts 42.
By rotating, the vertical position of the peeling member 44 can be adjusted, and by tightening the nut 43 in this state, the vertical position of the peeling member 44 can be fixed. Therefore, the release sheet support plate 46 and the release sheet 4
A release sheet position adjusting member (42 + 43) capable of adjusting the position 5 with respect to the heating roll Fh is configured.

5 and 6, the central portion 36a
And a shaft mounting portion 36 rotatable around the rotation operation shaft 29.
b, 36b (see FIG. 2)
6 rotates around the rotation shaft 29, the guide roll supporting leaf spring 37, the leaf spring fixing member 38, the screw N3 and the plurality of guide rolls 39 connected to the side surface of the central portion 36a; The peeling member 44 and the like supported at the lower part of the rotary member are rotated around the rotary operation shaft 29 together with the peeling member supporting member 36. 5 and 6, one end of a leaf spring 47 is supported on the front plate 1 and the rear plate 2 by a screw N4. The free end of the leaf spring 47 is connected to the central portion 36a of the peeling member supporting member 36. Locked. And the rotary operation shaft 2
The peeling member supporting member 36 rotatably supported on the
Normally, it is held at the position shown in FIGS. 3 and 5 by the leaf spring 47. Then, the peeling member supporting member 36
6, when the rotation operation shaft 29 moves from the rotation position of FIG. 5 to the rotation position of FIG. 6, and the peeling member moving cam 33 presses the central portion 36a of the peeling member support member 36 downward (FIG.
), And is configured to rotate counterclockwise around the rotation operation shaft 29.

(Operation of the First Embodiment) In the fixing device of the first embodiment having the above-described configuration, by rotating the operation handle 31 of FIG. 2, the pressing position (the heating roll Fh and the heating roll Fh) shown in FIGS. (The position where the pressure belt Fp is pressed)
The pressing belt Fp can be moved between the position shown in FIGS. 4 and 6 (the position where the heating roll Fh and the pressing belt Fp are separated). When the fixing operation is performed at the pressing position (FIGS. 3 and 5), first, silicone oil as a lubricant is applied to the surface of the low friction sheet 16. At the pressing position, the coil spring 18 as a pad pressing member presses the pad receiver 19 and the fixing pad 21 toward the heating roll Fh. When the heating roll Fh rotates at this pressure contact position, the pressure belt Fp rotates with the rotation of the heating roll Fh. The inner surface of the pressure belt Fp is kept in a state of low frictional resistance by silicone oil (lubricant) applied to the surface of the low friction sheet 16.

The belt guides 12, 13 mounted on the belt support frame 7 guide the inner peripheral surface of the pressure belt Fp when the pressure belt Fp rotates. Belt guide 12, 1
On the outer surface of the groove 3, concave grooves 12c and 13c are formed along the rotation direction of the pressure belt Fp. This concave groove 12c,
13c prevents the silicone oil adhering to the inner peripheral surface of the pressure belt Fp from moving in the longitudinal direction on the surfaces of the belt guides 12, 13. The belt support frame 7
The end mounting members 5, 6 respectively mounted on both ends of the pressure belt Fp and connected to the rotating levers 3, 4 are positioned in the belt width direction at the end of the pressure belt Fp by the belt outer end position regulating surfaces 5d, 6d. , And the inner peripheral surface of the end portion of the pressure belt Fp is guided by the belt end guide surfaces 5e and 6e. In this manner, the end mounting members 5 and 6 have the function of connecting the belt support frame 7 and the rotating levers 3 and 4, the function of regulating the position of the pressing belt Fp in the width direction, and the inner periphery of the end of the pressing belt Fp. By providing a surface guiding function, the number of components can be reduced.

When the operation handle 31 is at the position shown in FIG. 2, the rotary operation shaft 29 and the elevating cam 32 fixed to the rotary operation shaft 29 are held at the position shown in FIG.
Further, at this time, the pressure fixing members (Fp, 7 to 22) are held at fixing positions (positions shown in FIGS. 3 and 5) in pressure contact with a heating roll (fixing heating rotating member) Fh. In the state shown in FIGS. 3 and 5, the fixing pad 21 and the high-rigidity pad 22 are pressed downward by the heating roll Fh via the pressure belt Fp. At this time, the high rigidity pad 2
2, the lower end of the height adjusting portion 22g (see FIGS. 10, 12, and 21) abuts on the upper surface of the plate 9 (see FIG. 5);
The lowering position is regulated, and each coil spring 18 that pushes up the pad receiver 19 is compressed, and the upper right end of the pad receiver 19 moves downward away from the upper step 22 e of the high-rigidity pad 22.

In the state shown in FIG. 3, the high-rigidity pad 22 supported by the belt support frame 7 at a position downstream of the fixing pad 21 in the sheet conveyance direction extends in the belt width direction and the rotation lever 3 , 4 move to the pressing position, the pressing belt Fp is pressed against the heating roll Fh by the belt pressing surface 22f which presses against the back surface of the pressing belt Fp. Belt pressing surface 22f of the high rigidity pad 22
Since the surface of the heating roll Fh is depressed at the downstream end of the fixing region Q5, the recording sheet S discharged from the fixing region Q5 easily peels off from the surface of the heating roll Fh. The high-rigidity pad 22 is formed such that the height adjusting portion 22g is formed such that its height is high at the center in the longitudinal direction (the center in the belt width direction) and becomes lower toward both ends. The pressure is high at the center in the belt width direction of the region, and the pressure is low at both ends. Therefore, the fixing area Q5
Pressure distribution can be made appropriate.

When the operation handle 31 is rotated counterclockwise from the position shown in FIG. 2, the rotary operation shaft 29 rotates from the position shown in FIGS. 3 and 5 to the position shown in FIGS. At this time, the elevating cam 32 rotates counterclockwise together with the rotary operation shaft 29, and rotates from the position in FIG. 3 to the position in FIG. At this time, since the rod penetrating portions 3b and 4b of the rotating levers 3 and 4 are pressed downward by the lifting cam 32, the rotating levers 3 and 4 rotate clockwise around the lever support shafts 1b and 2b, and The pressure fixing member (Fp, 7 to 22) moves from a fixing position (a position in pressure contact with the heating roll Fh) in FIG. 3 to a separation position (a position separated from the heating roll Fh) in FIG. At this time, the force of the heating roll Fh separating from the pressure belt Fp and pressing the fixing pad 21 and the high-rigidity pad 22 downward is released, so that the coil spring 18 is extended. Due to the extension of the coil spring 18, the pad receiver 19 and the fixing pad 21 rise, and the upper right end of the pad receiver 19 pushes up the upper step portion 22e (see FIGS. 6 and 11) of the high-rigidity pad 22. At this time, the high-rigidity pad 22 rises, and the lower step 22 d separates from the upper surface of the plate 9. However, the lower end of the screw tip accommodation hole 22c of the high-rigidity pad 22 abuts on the lower surface of the screw N5, so that the rising position of the high-rigidity pad 22 from the upper surface of the plate 9 is regulated. Therefore, the fixing pad 21 and the high-rigidity pad 22 are held at the positions shown in FIGS.

That is, the upper step portion (part functioning as a fixing pad movement restricting member) 22e of the belt pressing member 22 supported by the belt supporting frame 7 is connected to the heating roll Fh by the coil spring (pad pressing member) 18. The movement of the fixing pad 21 pressed toward the heating roll Fh is restricted. Therefore, by separating the belt support frame 7 from the heating roll Fh, the upper step (fixing pad movement restricting member) 22e and the fixing pad 21 can be separated from the heating roll Fh. At this time, the pressure belt Fp is separated from the heating roll Fh together with the fixing pad 21 and the high-rigidity pad 22.

At the same time when the rotary operation shaft 29 and the elevating cam 32 move from the position shown in FIG. 3 to the position shown in FIG.
The cam 33 for moving the peeling member shown in FIG. 5 rotates counterclockwise together with the rotary operation shaft 29 to rotate to the position shown in FIG. In the position shown in FIG. 6, the peeling member moving cam 33 presses the central portion 36a of the peeling member supporting member 36 downward, so that the peeling member supporting member 36 is moved from the position shown in FIG. The above rotates counterclockwise to rotate to the position shown in FIG. At this time, the release member 44 is moved from the fixing position in FIG. 5 (the position where the tip of the release sheet 45 is close to the surface of the heating roll Fh) to the separation position (release sheet 45) shown in FIG.
(A position where the tip is separated from the surface of the heating roll Fh). Therefore, by rotating the operation handle 31 shown in FIG. 2, the pressure fixing member (Fp, 7 to 22) is separated and approached to the surface of the heating roll (fixing heating rotating member) Fh, and at the same time, the release sheet 45 The tip can be separated and approached to the surface of the heating roll (fixing heating rotating member) Fh.

The release sheet position adjusting member (42)
+43) (see FIGS. 5 and 6) using the release sheet support plate 4 with respect to the central portion 36a of the release member support member 36.
6 to adjust the position of the leading end of the release sheet 45 to the heating roll Fh and the pressure belt Fp.
A fixing area (recording sheet clamping section) formed by a pressure contact area of the pair of recording sheet clamping rotation members Fh and Fp.
It can be arranged at an appropriate position with respect to Q5. For this reason, the recording sheet S discharged from the fixing area (recording sheet holding portion) Q5 is transferred to the heating roll Fh and the pressure belt Fp (a pair of recording sheet holding rotating members Fh, Fp).
Can be reliably separated from the surface of the substrate. The rotation levers 3 and 4 can be rotated simultaneously with the rotation of the rotation operation shaft 29, the lifting / lowering cam 32 and the peeling member moving cam 33, and at this time, the belt supported by the rotation levers 3 and 4 The support members (5 to 22) can be easily moved to the pressure contact position where the pressure belt Fp and the fixing roll Fh are pressed against the separated position. At the same time,
The peeling member 44 can be separated or approached from the heating roll Fh. Therefore, when a jam (paper jam) occurs in the fixing device, the rotation operation shaft 29
By simply rotating, the jam processing can be easily performed.

The rotating levers 3 and 4 rotatably supported by the front plate 1 and the rear plate 2 as lever supporting frames are formed by bending a metal plate, and have a pair of parallel open ends. Guide edge 3c1,
3c1, 4c1, 4c1 and the pair of guide edges 3c1, 3
c1; 4c1, 4c1, an end mounting member insertion groove 3c; 4c having a bottom edge connected thereto, and locking members 3d, 4d provided at the bottom edge. 4
d locks the end mounting member inserted into the end mounting member insertion groove 3c; 4c in a non-rotatable manner. The turning levers 3 and 4 formed by bending the metal plate in this manner can be easily manufactured. When the end mounting members 5, 6 are inserted into the end mounting member insertion grooves 3c; 4c of the rotating levers 3, 4, a pair of parallel guide edges 3 of the rotating levers 3, 4 are provided.
c1, 3c1; 4c1, 4c1 are the end mounting members 5, 6 respectively.
Are guided in the pair of guided grooves 5a. End mounting members 5, 6 inserted into end mounting member insertion grooves 3c; 4c.
The locking member 5b of the rotating levers 3 and 4
d and 4d, and are supported by the rotating levers 3 and 4 in a predetermined posture. Therefore, the connecting work between the end mounting members 5 and 6 mounted on the belt support frame 7 and the rotating levers 3 and 4 is easy.

(Embodiment 2) FIG. 22 is an explanatory view of a main part of Embodiment 2 of the fixing device according to the present invention, and corresponds to FIG. 18 of Embodiment 1 above, and FIG. 22A shows the rotation of the pressure belt Fp. 22A is an explanatory diagram of an upstream belt guide disposed on the upstream side of the fixing region along the direction, FIG. 22A is a top view, and FIG.
FIG. 22B is a view from arrow XXIIB of FIG.
FIG. 22D is a sectional view taken along the line XXIIC-XXIIC of FIG.
B is a cross-sectional view taken along the line XXIID-XXIID, and FIG. 22E is a cross-sectional view of a main part in a state where the upstream belt guide is mounted on the belt support frame. FIG. 23 is an explanatory view of a main part of a second embodiment of the present invention and corresponds to FIG. 11 of the first embodiment. In the description of the second embodiment, components corresponding to the components of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. The second embodiment differs from the first embodiment in the following points, but has the same configuration as the first embodiment in other points. 22 and 23, the belt guide 12 is different from the first embodiment having four L-shaped projections in FIG. 18 in that the belt guide 12 has four columnar projections 12a whose tip ends are swollen. In addition, one circular projection locking hole 8b1 shown in FIG. 22D and three elliptical projection locking holes corresponding to the four columnar projections 12a are formed in the frame body portion 8b constituting the belt supporting frame 7. Hole 8b1 '(FIG. 22D
(Only one is shown). In the second embodiment, when the four columnar projections 12a of the belt guide 12 are inserted into the projection locking holes 8b1 and 8b1 ', the columnar projections 12a are elastically deformed and can be detached from the projection locking holes 8b1 and 8b1'. Can be installed. Therefore, in the second embodiment, the belt guide 12 can be easily attached to and detached from the belt support frame 7 as in the first embodiment. Therefore, the work of attaching and detaching the belt guide to and from the belt support frame can be easily performed in a short time.

(Modification) Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above-described embodiments, but includes the gist of the present invention described in the claims. Various changes can be made within the scope. Modified embodiments of the present invention will be exemplified below. (H01) Belt guide 1 for belt support frame 7
The attachment / detachment structures 2 and 13 can adopt a configuration other than the configuration shown in the embodiment. For example, in the second embodiment, the columnar projection 12a can be formed with a cross-shaped slit in the axial direction. In addition, as the belt guide mounting portion (H02) formed on the belt support frame 7, metal tubular members having various cross-sectional shapes can be used. (H03) The rotation of the rotary operation shaft can be performed by using a drive motor or a solenoid instead of using the operation handle. (H04) In FIGS. 4 and 6 of the first embodiment, although the pressing belt Fp is lowered to a position completely separated from the heating roll Fh, the pressing belt Fp comes into contact with the heating roll Fh, but the pressing force is reduced. It is also possible to configure so as to descend to a position where it becomes almost zero.

[0065]

The above-described image forming apparatus of the present invention has the following effects. (O01) In a fixing device including a heating roll, a pressure belt pressed against the heating roller, and a belt supporting member rotatably supporting the pressure belt, a belt-shaped belt support frame is used, so that the belt is supported. The frame can be configured with high rigidity and small size.
Also, a guide mounting portion is provided on a pair of side walls of the cylindrical belt support frame, and a mounted portion of the belt guide can be removably mounted on the guide mounting portion, and the guide mounting portion is configured by a through hole. Since the mounting portion can be formed by a projection penetrating the through-hole, assembly and disassembly of the belt support member can be performed in a short time.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a color image forming apparatus having a fixing device including a fixing device according to a first embodiment of the present invention.

FIG. 2 is an overall explanatory view of the fixing device shown in FIG. 1 and is a perspective view.

FIG. 3 is an explanatory view of a main part of a section taken along line III-III of FIG. 2 (or a sectional view taken along line III-III of FIG. 9), and is a view showing a state in which a pressure belt is pressed against a heating roll.

4 is an explanatory view of a main part of a cross section taken along the line IV-IV of FIG. 2 (or a cross-sectional view taken along the line IV-IV of FIG. 9B), showing a state in which the pressure belt is separated from the heating roll. It is.

FIG. 5 is an explanatory view of a main part of a cross section taken along line VV in FIG. 2 (or a sectional view taken along line VV in FIG. 9B). It is a figure showing the state held at the operation position.

FIG. 6 is an explanatory view of an essential part of a cross section taken along line VI-VI in FIG. 2 (or a sectional view taken along line VI-VI in FIG. 9B), in which a pressure belt is pressed against a heating roll and a sheet peeling member is fixed. It is a figure showing the state where it was held at the separation position apart from the roll surface.

FIG. 7 shows the front plate 1 and the rear plate 2 and pivot levers 3 and 4 supported on the inner surfaces thereof.
FIG.

FIG. 8 is a perspective view of the rotating levers 3 and 4.

9 is an explanatory view of a belt supporting member supported by the rotating lever and a pressing belt rotatably supported by the belt supporting member. FIG. 9A is a plan view, and FIG. 9B is a drawing of FIG. 9A. It is an IXB-IXB line sectional view.

FIG. 10 is an exploded view of the member shown in FIG. 9B.

FIG. 11 is a sectional view of a main part of FIG. 9B, and FIG.
1A is a sectional view taken along the line XIA-XIA in FIG. 9B, and FIG. 11B is a sectional view taken along the line XIB-XIB in FIG. 9B.

FIG. 12 is an exploded view of a cross-sectional view taken along the line IIIA-IIIA of FIG. 9B (see FIG. 3A).

FIG. 13 is an explanatory view of an end mounting member mounted on the front end of the belt support frame and supported by the front rotation lever 3, FIG. 13A is a perspective view of the end mounting member,
13B is a front view of the end mounting member, FIG. 13C is a top view of the end mounting member, and FIG. 13D is a rear view of the end mounting member.

14 is an explanatory view of the end mounting member shown in FIG. 13; FIG. 14A is a side sectional view showing the XIV of FIG. 13B;
FIG. 14B is a cross-sectional view taken along the line A-XVIA, and FIG.
FIG. 14C is a sectional view taken along line XIVC-XIVC of FIG. 3B, and FIG. 14C is a sectional view taken along line XIVC-XIVC of FIG.

FIG. 15 is an explanatory diagram of a belt support frame.
15A is a plan view, and FIG. 15B is an arrow XV in FIG. 15A.
FIG. 15C is a view from the arrow XVC of FIG. 15A.

FIG. 16 is an enlarged view of a main part of FIG. 15, and FIG.
6A is a view showing the shape of the plate 9 at the portion indicated by the arrow XVIA in FIG. 15A, and FIG. 16B is a view showing the arrow X in FIG. 16A.
It is a figure which shows the shape of the upstream wall 8b of the frame main body of the part shown by VIB.

FIG. 17 is a sectional view of a main part of FIG. 15A, and FIG. 17A is a view seen from the arrow XVIIA of FIG.
7B is a sectional view taken along the line XVIIB-XVIIB in FIG. 15A, FIG. 17C is a sectional view taken along the line XVIIC-XVIIC in FIG. 15A,
17D is a sectional view taken along the line XVIID-XVIID of FIG. 15A, FIG. 17E is a sectional view taken along the line XVIIE-XVIIE of FIG. 15A, and FIG. 17F is a sectional view taken along the line XVIIF-XVIIF of FIG.

18 is an explanatory view of an upstream belt guide disposed on the upstream side of the fixing area along the rotation direction of the pressure belt Fp. FIG. 18A is a top view, and FIG. 18B is a view from the arrow XVIIIB in FIG. 18A. FIG. 18C is a sectional view taken along line XVIIIC-XVIIIC of FIG. 18A, and FIG.
B is a cross-sectional view taken along line XVIIID-XVIIID, FIG. 18E is a cross-sectional view of a main part of the state in which the upstream belt guide is being mounted on the belt support frame, and FIG. 18F is a main part of the state in which the upstream belt guide is mounted on the belt support frame. It is sectional drawing.

19 is an explanatory view of a downstream belt guide disposed downstream of the fixing area along the rotation direction of the pressure belt Fp. FIG. 19A is a top view, and FIG. 19B is a view from the arrow XIXB of FIG. 19A. FIG. 19C shows the XI of FIG. 19B.
It is an XC-XIXC line sectional view.

FIG. 20 shows a pressure belt F passing through a fixing area.
It is explanatory drawing of the low friction sheet arrange | positioned at the back of p.

21 is an explanatory view of the high-rigidity pad 22, FIG. 21A is a left side view of the high-rigidity pad 22, FIG. 21B is a view from the arrow XXIB of FIG. 21A, and FIG. 21C is XXIC of FIG. 21A. It is -XXIC sectional drawing.

FIG. 22 is an explanatory view of a main part of a fixing device according to a second embodiment of the present invention, corresponding to FIG. 18 of the first embodiment, and FIG. 22A is a view along the rotation direction of the pressure belt Fp. FIG. 22A is a top view, FIG. 22B is a view from arrow XXIIB in FIG. 22A, and FIG. 22B is XXII in FIG. 22A.
22D is a sectional view taken along line C-XXIIC, and FIG.
FIG. 22E is a cross-sectional view taken along the line IID-XXIID. FIG.

FIG. 23 is an explanatory view of a main part of a second embodiment of the present invention, and corresponds to FIG. 11 of the first embodiment.

[Explanation of symbols]

F: fixing device, Fh: heating roll, Fp: pressure belt,
Q5: fixing area, S: recording sheet, 1: moving member support frame (lever support frame, front plate), 2
... moving member supporting frame (lever supporting frame, rear plate), 3, 4 ... moving member (rotating lever), 3c1,
3c1, 4c1, 4c1 ... guide edge, 3c; 4c ... end mounting member insertion groove, 3d, 4d ... locking member, 5, 6 ... end mounting member, 5a, 5a ... guided groove, 5b ... engaged Stop,
5d, 6d: belt outer end position regulating surface, 5e, 6e: belt end guide surface, 5e1, 6e1: groove, 7: belt support frame, 8a: lower wall, 8b: upstream wall, 8c: downstream wall,
(8b, 8c) ... a pair of side walls, 8b1, 8c2 ... guide mounting portion (through hole), 9 ... upper wall (plate), 12, 13 ...
Belt guide, 12a, 13a: mounted portion (projecting member), 12c, 13c, concave groove, 18: pad pressing member,
21: fixing pad, 22: high rigidity pad, 22e: fixing pad movement restricting member (upper step), 22f: belt pressing surface, 27: lever urging member, 31: operating handle (operating member for lever rotation), 45 ... Release sheet, (5-22)
... belt support member, (29, 32) ... lever rotation position adjustment member,

Continued on the front page (72) Inventor Tomofumi Suzuki 2274 Hongo, Fuji Xerox Co., Ltd., Ebina City, Kanagawa Prefecture (72) Inventor Kazumi Inaba 2274 Hongo, Hongo Ebina City, Kanagawa Prefecture, Fuji Xerox Co., Ltd. (72) Inventor Nagaoka Okegawa 2274 Hongo, Ebina-shi, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Inventor Shuichi Suzuki 2274 Hongo, Ebina-shi, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. Address Fuji Xerox Co., Ltd. (72) Inventor Masayuki Kono 2274 Hongo, Ebina-shi, Kanagawa Prefecture F-Xerox Co., Ltd. F-term (reference) 2H033 AA21 AA31 BA11 BA12 BB34

Claims (3)

[Claims] 1. A fixing device having the following constitutional requirements (A01) to (A05): (A01) a fixing area is formed by areas which are in pressure contact with each other, and a recording sheet which has entered the fixing area is sandwiched between the recording sheets. A heating roll and an endless pressure belt rotating in the conveyance direction; (A02) an upstream wall disposed along the belt width direction inside the endless pressure belt and disposed upstream in the sheet conveyance direction; A cylindrical belt support frame having a pair of side walls having a downstream wall disposed on the downstream side of the wall and an upper wall and a lower wall connecting the pair of side walls, and supported by the belt support frame; A fixing pad that presses the back surface of the pressure belt toward a heating roll, and an upstream belt that is attached to the upstream wall and the downstream wall and guides the inner peripheral surface of the pressure belt. (A03) a belt support member rotatably supporting the pressure belt, supporting the cylindrical belt support frame, and being adjacent to both ends in the width direction of the pressure belt. Movably supported by the moving member supporting frames respectively disposed and moved between a pressing position for pressing the pressing belt against the heating roll and a separating position for separating the pressing belt from the heating roll. A pair of movable members, (A04) a pair of side walls provided with guide mounting portions, respectively, and (A05) mounted portions detachably mounted on the guide mounting portions of the upstream wall and the downstream wall, respectively. A pair of belt guides constituted by the provided upstream belt guide and downstream belt guide. 2. The method according to claim 1, wherein the following component requirements (A06) are provided.
(A06) The guide mounting portion and the mounted portion, one of which is formed by a through hole and the other of which is formed by a protruding member penetrating the through hole. 3. The method according to claim 2, wherein the following component requirement (A07) is provided.
(A07) The protruding member having a back surface contact portion that comes into contact with the back surface of the side wall when moved in the belt width direction while passing through the through hole.