JPH08146801A - Heating and fixing device - Google Patents

Abstract

PURPOSE: To prevent light and heat from being leaked from an engaging part, to improve the strength of the engaging part, to thin a heating roller and to contrive uniform heating by engaging the recessed part or the projected part of the heating roller with the projected part or the recessed part of a driving transmitting means. CONSTITUTION: At the end of a hollow cylindrical heating roller 1, the outer peripheral surface 50 of the roller 1 has the recessed part 51 which is constituted by displacing from the peripheral surface 50 to the center 54 side of the roller 1 and having a surface formed continuously from the surface 50 at least at one part; and at a position corresponding to the recessed part 51, the inner peripheral surface 52 of the roller 1 has the projected part 53 constituted by displacing from the inner peripheral surface 52 to the center 54 side of the roller 1, thereby constituting a key way part 55. Meanwhile, the projected part 56 from the inner peripheral surface 57 to the center is formed at one part of the inner peripheral part of a gear being the driving transmitting means 7 at a position where it is fitted in the recessed part 51 of the roller 1, and the projected part 56 is engaged with the recessed part 51 so as to decide the relative positions of both of them and transmit the rotating driving force.

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 an image formed on a sheet material of a printer, a facsimile, a copying machine or the like, and more particularly to a heating roller driving structure of a heating and fixing device.

[0002]

2. Description of the Related Art A heating roller fixing device has been conventionally used as a heating fixing device for fixing an unfixed image in an electrophotographic recording device, and as disclosed in Japanese Utility Model Laid-Open No. 56-145061, aluminum is used. It is known that a heat insulating member or a gear made of a heat-resistant resin is fitted to the end of the heating roller, and then fixed and joined to the heating roller with a set screw. However, with such a configuration, the following 1),
There were problems 2), 3) and 4).

1) Since the heating roller rotates while being heated from approximately 150 ° C. to 200 ° C., due to the difference in the coefficient of thermal expansion between the heating roller and the gear, a gap is created between the heating roller and the gear, and the fastening force by the set screw is applied. Is lost, the gears spin idle, and stable drive cannot be transmitted to the heating roller, causing image blurring, jitter, uneven fixing, wrinkles, abnormal noise, etc. It became a serious defect such as falling off.

2) The set screw portion must be provided on the boss portion excluding the gear portion, which not only hinders downsizing of the fixing device due to the large gear component, but also the end portion of the heating roller due to heat transfer to the gear. And the fixing strength was insufficient at the edge of the fixed image. In particular, it was remarkable with a thin heating roller.

3) The thin screw heating roller is deformed into an elliptical shape due to the thrust of the set screw, which causes the heating roller to swirl and change the conveyance speed of the object to be fixed (sheet material), resulting in image blurring and fixing. Mura and wrinkles occurred. In addition, the heating roller may be seriously damaged.

4) In contrast to 2) and 3), the thickness of the heating roller made of aluminum or the like is increased to, for example, 2 mm.
Although we have tried to improve by doing the above, on the other hand, it took a very long time to warm up. It is effective to reduce the wall thickness of the heating roller in order to speed up the warm-up, but the wall thickness becomes thin, particularly 1.0 mm or less, and particularly 0.
If it is 8 mm or less, the temperature of the end portion of the heating roller is very remarkable, the strength is insufficient, and the accuracy is deteriorated due to deformation, which hinders the thinning of the heating roller. As a result, the wait time is not shortened. .

Further, FIG. 9 is an explanatory view of an embodiment of a conventional heat fixing device. As a drive unit mechanism that has been conventionally used, a key groove 101 is formed at the end of the heating roller 1 by cutting, etc., and a gear 7 having a key 102 (projection) is fitted to a portion corresponding to the key groove 101 to rotate it. Methods of transmitting driving force have been known. A halogen lamp (hereinafter referred to as a halogen lamp 3) as a heating means 3 is installed in the heating roller 1, and the heating roller 1 is rotatably supported by a support frame 6 by a bearing 40. The gear 7 is a train wheel 10.
The driving force is transmitted by 3.

As disclosed in Japanese Patent Publication No. 4-13711, etc., in order to block light and heat from the heating means, a shading means (heat insulating cap) 10 is provided at the end of the heating roller 1.
4 may be arranged. Further, the photoconductor 24 is arranged close to the heating roller 1.

In such a structure, since the heating roller 1 made of aluminum or the like is maintained at a high temperature, it also thermally expands in the roller axis direction. Therefore, in order to absorb this, the key 102 is arranged with a gap 105 in the axial direction with respect to the key groove 101. Light from the halogen lamp 3 leaks from the gap 105. The light blocking means 104 includes the train wheel 103 and the gear 7.
Due to the engagement of the above, there is an opening in part and a complete light shielding structure cannot be taken. Therefore, the photothermal flux of the halogen lamp 3 may directly hit the photoconductor 24, the train wheel, the transfer means, etc. through this opening, and the photoheat flux may be partially exposed or heated to a high temperature. There were problems 5), 6) and 7).

5) When the photoconductor 24 is locally exposed to the light and heat from the gap 105 or further heated, the charge state and the sensitivity of the photoconductor may be uneven, and uneven printing may occur or may be serious. In some cases, the life of the device was significantly reduced due to heat deterioration. Further, when the transfer roller as the transfer means is heated, the resistance value changes, and uneven transfer occurs. On the other hand, when a plastic member such as a train wheel in the vicinity is heated, the heat-resistant temperature is low, so that deformation and melting occur, which causes problems such as image distortion and abnormal noise due to uneven feeding speed.

6) Further light-shielding means was required to prevent this.

7) The key portion 102 of the gear 7 made of heat-resistant plastic is directly heated by the light heat from the halogen lamp 3. The parts other than the key part 102 are heated by heat conduction from the heating roller. When the heat conductivity of the gear 7 is low, the temperature becomes locally high only near the key portion 102, heat distribution occurs, and the gear deforms. This fluctuates the rotation speed of the heating roller and causes image blurring and wrinkles in the fixing section. Further, since the driving torque of the fixing device fluctuates, the load on the entire train wheel fluctuates, which causes image disturbance due to fluctuations in the feed speed.

On the other hand, the conventional constructions described so far have the mechanical problems shown in 8), 9), 10) and 11) below.

Since the end portion of the heating roller is the key groove portion 101,
Unlike other parts, it has a hollow open cross-section structure. This portion receives the rotational torque from the gear 7 and the axial force caused by the gear pressure angle. Generally, in a hollow cross section such as the heating roller 1, when a constant torque is applied, the shear stress in the open cross section with slits is ten times more than that in the closed cross section without slit (when the heating roller diameter is 20 mm and the wall thickness is 1 mm. ), The shear stress is increasing as the heating roller becomes thinner.

Further, since the heating roller rotates while being heated from approximately 150 ° C. to 200 ° C., a gap is created between the heating roller and the gear due to the difference in the coefficient of thermal expansion between the heating roller and the gear, and the heating roller 1 and the gear. The fitting portion 7 rotates with a gap. Therefore, the key portion 102 and the key groove portion 101 repeat the relative sliding motion in the radial direction depending on the rotation angle.

When a radial force is applied to the end portion of the slit such as the key groove portion 101 in such a state, the heating roller is deformed into an elliptical shape to increase the gap. Further, this force is periodically applied to the key groove portion 101 while changing its direction depending on the rotation angle of the roller. Therefore, the key groove portion is periodically deformed up to the gap between the gear 7 and the heating roller 1. This is a major cause of fatigue failure because a repeated bending load of both swings is applied near the key groove portion 101 of the heating roller 1. From these, 8) The bending stress in the key groove portion 101 of the heating roller 1 was superimposed on the shear stress due to the torque, and the heating roller was damaged particularly near the key groove portion, and the apparatus became inoperative. In particular, it was remarkable when the thickness of the heating roller 1 was 1 mm or less.

9) When the thin open cross-section structure having the key groove portion 101 is used, the end portion of the heating roller 1 is deformed, and as a result, whirling of the heating roller 1 occurs, and uneven fixing strength occurs.
Wrinkles and image blur.

10) The key portion 102 deforms the heating roller to increase the gap, and the key portion 102 and the key groove portion 10
Both of them are worn by the slip of 1, and the edge of the key groove portion 101 scrapes off the key portion 102, the drive transmission becomes unstable, and the rotation of the heating roller fluctuates. There has occurred. In addition,
Due to wear, power transmission cannot be transmitted and heating roller 1
Was sometimes stopped.

11) Further, a large noise is periodically generated due to slippage or the edge of the key groove portion 101 being caught by the key portion 102, which reduces the quietness of the device and makes the user feel uncomfortable. .

In order to improve these problems, US Pat. No. 4,952,782 discloses an opening made of a heat resistant resin containing heat resistant grease between a heating roller having a key groove and a gear having a key. A configuration is disclosed in which a spacer is installed, the sliding characteristics of the key portion and the key groove portion are improved, and the device life due to wear is extended. However, even with this configuration, the sliding characteristics are improved, but the gap is rather increased due to the thickness tolerance of the spacer, so 8),
The problem of 9) was not solved and became worse. In addition, it is difficult to improve the sliding characteristics for a long time due to the scattering of grease, and the scattering grease adheres to the halogen lamp 3 to shorten the life of the lamp, or adheres to the photoconductor to cause image deterioration. There was a problem.

Further, in US Pat. No. 5,184,952, the heating roller has key groove portions arranged at a plurality of positions,
It discloses a configuration in which a plurality of key portions are installed at the corresponding portion of the gear. As a result, the deformation of the gear is made uniform, and an increase in the gap between the gear and the heating roller due to the deformation of the gear is suppressed. However, since the heating roller has key groove portions at a plurality of locations, the strength is extremely insufficient, and the gap due to deformation of the heating roller increases, and the problems 8), 9), 10), and 11) cannot be solved. In addition, unless high-precision machining that perfectly matches the relative positional relationship between the plurality of key portions and the key groove portion is performed, the load concentrates at one place and the deformation is promoted due to one-sided contact.

In another embodiment of US Pat. No. 5,184,952, a plurality of key groove portions are provided in a gear portion, and a plurality of key portions are arranged at positions corresponding to the key groove portions on the outer circumference of the heating roller. A configuration is disclosed. In the examples, there is no detailed description of the key part, and only the example in which the heating roller has a protrusion on the outer circumference and the inner circumference has a non-uniform wall thickness is disclosed. However, in this structure, the heat capacity of the end portion of the heating roller is increased, so that the temperature is decreased at the end portion. Further, since the heat distribution also changes, thermal deformation also occurs, which adversely affects the image.

12) Further, it is extremely difficult to form a solid protrusion on the outer periphery in the production of the heating roller, and it is impossible to easily and accurately process the roller by centerless polishing or grinding by one chucking. . Therefore, not only is the heating roller molded through multiple steps to become expensive, but it is difficult to process and the processing tolerances are piled up, making it difficult to obtain the accuracy of the heating roller. Printing defects such as uneven fixing and wrinkles occurred.

[0024]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned conventional problems, and an object thereof is to eliminate light heat leaked from the engaging portion of the heating roller with the drive transmission means, and particularly to reduce the thickness. By improving the strength of the engaging part of the heating roller to prevent problems such as damage, and reducing the amount of deformation, it is possible to obtain an image of high print quality without image blurring, fixing unevenness, and wrinkles, and to reduce the thickness of the heating roller. The present invention is to provide a heating and fixing device that enables uniform heating, realizes sufficient strength and precision with a simple structure and processing of a thin heating roller, has a quick warm-up, and consumes less power.

[0025]

A heating and fixing device of the present invention comprises a hollow cylindrical heating roller which is brought into contact with an unfixed image and heated by the heating means, and a drive transmission means which is fitted to the outer periphery of the heating roller. In the heat fixing device, the outer peripheral surface of the heating roller has a recess having a surface continuously formed from at least one outer peripheral surface displaced from the outer peripheral surface toward the center of the heating roller. The means has a convex portion, which is directed toward the center from the inner peripheral surface corresponding to the concave portion, is formed in a part of the inner peripheral portion fitted to the outer periphery of the heating roller, and when the heating roller and the drive transmission means are fitted, the concave portion is formed. It is characterized in that the convex portions are engaged with each other.

Further, the heat fixing device of the present invention is characterized in that the concave portion is a diaphragm portion formed on the heating roller.

Further, the heat fixing device of the present invention is characterized in that the concave portion has no opening with respect to the outer periphery of the heating roller.

Further, the heat fixing device of the present invention has a hollow cylindrical heating roller which comes into contact with an unfixed image and is heated by the heating means, and a drive transmitting means which is fitted to the outer periphery of the heating roller. In the above, the outer peripheral surface of the heating roller has at least one convex portion having a surface formed by a squeezed portion continuous from the outer peripheral surface displaced from the outer peripheral surface with respect to the center of the heating roller. The transmission means has a concave portion, which corresponds to the convex portion and which is directed outward from the inner peripheral surface, is formed in a part of the inner peripheral portion fitted to the outer periphery of the heating roller, and the heating roller and the drive transmission portion are fitted to each other. At this time, the convex portion and the concave portion are engaged with each other.

Further, the heat fixing device of the present invention is characterized in that the convex portion has no opening with respect to the outer periphery of the heating roller.

[0030]

According to the above-mentioned structure of the present invention, the concave portion or the convex portion on the outer peripheral surface of the heating roller is not cut off by cutting or the like like the conventional key groove, and the flange is radially formed around the concave portion or the convex portion. With the additional structure, the mechanical strength in the vicinity of the concave portion or the convex portion is improved, the stress is relieved, and the deformation is reduced against the torque and the axial force from the drive transmission means.

Further, the concave portion or the convex portion of the heating roller is
Since the outer peripheral surface of the heating roller is formed by a narrowed portion having no opening, it has a thin closed cross-section structure, and 1) prevents leakage of light heat from the concave portion or the convex portion of the heating roller to the periphery of the photoconductor or the transfer unit.

2) In order to prevent light heat from directly hitting the concave portion or the convex portion of the heating roller to the convex portion or the concave portion of the drive transmitting means engaging with the heating roller, the drive transmitting means is uniformly heated and the heat distribution is uniform. To prevent local thermal deformation.

3) Shear stress and bending stress are relieved to prevent damage or fatigue damage at the concave or convex portion of the heating roller.

4) The rigidity of the heating roller is improved, and whirling due to deformation of the end portion is prevented.

5) Since the deformation of the heating roller is small and the gap between the driving roller and the driving force transmitting means is not increased, the abrasion between the convex portion or the concave portion of the driving force transmitting means and the concave portion or the convex portion of the heating roller is reduced. Further, since the engaging portion has no edge portion, neither is caught.

6) It has sufficient strength and rigidity even if a large radial thrust is applied to the end portion of the heating roller.

7) Since the end portion of the heating roller is formed by drawing, the drawing portion can be configured to have substantially the same thickness as the other portions, and the heating roller has a thin wall closed cross-section structure of substantially uniform thickness. , The heat capacity of the end of the heating roller is also uniform in the circumferential direction and the axial direction, and the temperature drop at the end can be prevented,
Thermal deformation due to heat distribution can also be suppressed.

[0038]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view of an apparatus for explaining the overall structure of an image forming apparatus equipped with a heat fixing device of the present invention.
The general operation of this device will be described.

In FIG. 1, there is a charging roller 28 as a charging means on the outer periphery of the photoconductor 24 which rotates in the direction of arrow A by a drive source (not shown). The charging roller 28 is the photoconductor 2
4, a voltage is applied from a high voltage power source (not shown) to uniformly charge the surface of the photoconductor. The charged photoconductor 24 is selectively exposed by a laser scanning optical system 29, which is an exposing unit, to form a latent image on the photoconductor 24.

The latent image formed on the surface of the photoconductor 24 is visualized by the toner supplied by the developing roller 30 which is a developing means. The transfer roller 26, which is a transfer unit, comes into contact with the photosensitive member 24 on the downstream side of the developing unit, and a voltage is applied from a high voltage power source (not shown).

On the other hand, the recording paper 21 which is sequentially separated and fed by the paper feeding roller 22 which is a paper feeding means is the photosensitive member 2.
4 and the transfer roller 26, the toner image is transferred to the recording paper 21. The recording paper 21 on which the toner image is transferred onto the photoconductor 24 by the transfer means is a support frame for supporting the heating roller 1 having a halogen lamp as the heating means 3 therein and the pressure roller 10 which is in pressure contact with the heating roller 1. The toner image is fixed on the recording paper 21 by being nipped and conveyed by the heating and fixing device constituted by 6.

Further, the developed toner image is transferred to the photosensitive member 24.
Cleaning blade 44, which is a cleaning unit that removes the transfer residual toner on the photoconductor 24 after the transfer.
Are disposed in contact with each other on the photoconductor 24. The toner circulation path is connected to the toner circulation path 42a on the cleaning means side and the toner circulation path 42b on the developing means side by a connection path (not shown) to form a one-way connection path.
Although not shown, a toner conveying means including a screw conveyor and a coil spring is arranged in the toner circulation path, and the toner is circulated and conveyed between the cleaning means and the developing means.

Although not shown, a toner replenishing means is connected to a part of the toner circulation path to replenish the toner consumed by printing. The transfer residual toner scraped off by the cleaning blade 44 accumulates in the toner circulation transport path 42a on the cleaning means side due to gravity, is transported and transported in the toner circulation path by the toner transport means, and reaches the toner transport path 42b on the developing means side. Although not shown, the toner is supplied to the developing means through an opening provided in the toner transport path 42b.

Here, the drive transmission portion of the heat fixing device of the present invention will be described.

FIG. 2 is an explanatory view of an embodiment of the drive transmission portion of the heat fixing device of the present invention.

At the end of the hollow cylindrical heating roller 1, at least one outer peripheral surface 50 of the heating roller 1 is continuous from the outer peripheral surface 50 which is displaced from the outer peripheral surface 50 toward the center 54 side of the heating roller 1. Recessed portion 51 having a formed surface
The inner peripheral surface 52 of the heating roller 1 has a convex portion 53 displaced toward the center 54 side of the heating roller 1 from the inner peripheral surface 52 at a position corresponding to the concave portion 51, and the key groove portion 55.
Is composed.

In the case of the present embodiment, the key groove portion 55 is formed by total drawing, and the concave portion 51 is a drawing portion which is continuous with the outer peripheral surface 50 of the heating roller 1 and is formed on the outer peripheral surface 50 of the heating roller 1. It has a thin-walled closed-section structure with no openings.

On the other hand, at a position fitted into the concave portion 51 of the heating roller 1, a convex portion 56 (hereinafter referred to as a key portion 56) directed toward the center from the inner peripheral surface 57 is formed on a part of the inner peripheral portion of the gear which is the drive transmission means 7. Is described), the convex portion 56 engages with the concave portion 51, determines the relative position between the two, and transmits the rotational driving force. Further, the inner peripheral surface of the drive transmission means 7 and the heating roller 1
The outer peripheral surface 50 has substantially the same diameter, but has a gap necessary for fitting and absorbing the dimensional change of thermal expansion.

Further, the heating roller 1 rotates while being supported by a support frame by a bearing (not shown). The heating means 3 is arranged so as to penetrate through the hollow inside of the heating roller 1.
The heating unit 3 is supported by a support frame or a terminal fixed to the image forming apparatus, receives the supply of electric power to heat the heating roller 1, and detects a temperature-sensitive element on the outer periphery of the heating roller 1 (not shown). The heating roller 1 is maintained at a predetermined temperature necessary for melting the toner by guiding the signal to the control means and controlling the input voltage to the heating means. Although not shown, the pressure roller 10 is rotatably supported by bearings, and is pressed against the heating roller 1 at least during fixing by a known pressing means to form a pressure contact portion with the heating roller. .

Here, the heating roller 1 comprises a tetrafluoroethylene resin (PTFE), a tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) on the outer periphery of a hollow cored bar made of aluminum alloy, stainless steel, copper alloy or the like. ), A tetrafluoroethylene-hexafluoropropylene copolymer (FEP) or other heat-resistant mold-releasing resin is provided in a thickness of about 10 to 40 μm, and a heat-resistant black paint is applied to the inner circumference. Increasing the efficiency of radiant heat absorption. Furthermore, as another example, the hollow core metal may be formed of a heat-resistant resin such as polyimide resin, polyamide resin, or polyamide-imide resin, or a thin-walled cylindrical belt such as a nickel alloy, and a heat-resistant release layer may be provided on the hollow core metal. good.

The pressure roller 10 comprises a metal shaft and silicone rubber, fluororubber, or fluorosilicone rubber provided relatively thickly on the outer circumference of the roller. As still another example, a belt made of resin such as silicone or fluorine, or rubber may be used.

As the heating means 3, a halogen lamp is used as an example. Tungsten is used for the filament which is the light emitting portion, and a foil portion made of molybdenum is provided at the end portion, and these are enclosed in a quartz glass tube by adding a slight amount of halogen gas to an inert gas. The foil portion is connected to the contact, which is further supported by the terminal, so that heat can be generated by energization. As another example of the heating means, a sheath heater or a resistance heating element may be used.

Gears which are an example of the drive transmission means 7 are made of polyimide resin, polyamide resin, polyamide-imide resin,
A resin gear made by adding a filler such as glass fiber, glass beads, graphite, carbon fiber, fluororesin, molybdenum disulfide, or titanium oxide to a heat resistant resin such as polyphenylene sulfide resin is used. Alternatively, a metal gear in which graphite is added to a copper-based, copper-iron-based, or iron-based metal is used.

Next, the reason why the structure of the drive transmission portion in the present invention has improved strength and reduced deformation as compared with the conventional example will be described.

FIG. 10 is an explanatory view showing the deformation of the heating roller of the conventional heating and fixing device due to the load.

Conventionally, the outer periphery of the end portion of the heating roller 1 is provided with an opening portion 60 for engaging a key, a torque T61 for rotational drive is applied, and a train wheel (not shown) and a gear which is the drive transmission means 7 are provided. Since it is gear transmission, force F62 is applied in the direction of the pressure angle of the gear. The heating roller 1 has an opening 60.
And a torque T61 generates a shear stress τ in the circumferential direction of the heating roller 1.

The shear stress τ when a torque T is applied to a thin open section having an average diameter D and a wall thickness t is τ = 3T / (π
It is represented by Dt ² ).

As shown in the lower diagram of FIG. 10, the force F62 can be decomposed into a circumferential component F1 and a radial direction F2, and F1 increases the shear stress τ, and it is easy to form a thin open cross-section structure by the action of widening the opening. It has been transformed. Further, it is inevitable that the gear and the opening are inclined and hit against each other at the tip of the opening, but in this case, F2 tries to deform the opening in the radial direction, and when the thin open cross-section structure is adopted. It is easily deformed near the opening to generate bending stress σ. Therefore, the heating roller 1 is deformed into a substantially elliptical shape as indicated by a broken line 66 in the figure, and a gap L67 is generated. Further, the opening 6
0 moves due to the rotation of the roller, but the force F2 has a constant direction, so that both the deformation and the stress fluctuate periodically. As described in the related art, the stress, the deformation, and the increase in the gap have an adverse effect.

FIG. 3 is an explanatory view for explaining the deformation due to the load of the heating roller of the embodiment of the heat fixing device of the present invention.

The heating roller 1 receives a torque T61 from the gear which is the drive transmission means 7 and a force F62 caused by the pressure angle of the gear.
Rotate while receiving. The key groove portion 55 is formed by total drawing, is a continuous drawn portion on the outer peripheral surface 50 of the heating roller 1, and has a thin-walled closed cross-section structure with no opening to the outer peripheral surface 50 of the heating roller 1. At this time, in the key groove portion of the heating roller, a shear stress τ1 is generated in the roller outer peripheral direction by the torque T, and a bending stress σ1 is generated when the force F is applied near the tip of the key groove portion 55 by one-sided contact. Also,
The shear stress τ when the torque T is applied to the thin closed section having the average diameter D and the wall thickness t is represented by τ1 = 2T / (πD ² t).

The ratio K of the shear stress τ1 of the thin wall closed cross section and the shear stress τ of the thin wall open cross section is expressed as K = τ1 / τ = 2t / 3D.

Conventionally, t / D is usually 1/10 to 1 /
Often set to about 20, K is 1/15 to 1
/ 30. Also, as a relatively thin heating roller,
Taking the average diameter D = 20 mm and the wall thickness of 0.6 mm as an example,
K = 1/50. As described above, since the structure of the present embodiment has a thin wall closed cross-section structure, the shear stress is 1/10 that of the conventional one.
From the above, it was reduced to 1/50 or less, and it was possible to improve the strength and reduce the deformation amount.

The same applies to the deformation due to the force F62. In the thin wall closed cross-section structure of this embodiment, the force F62 is decomposed into a circumferential component force F1 and a radial component force F2, as shown in the lower diagram of FIG. However, because of the closed cross-section structure with no opening for F1, the key groove 55 is hardly deformed and does not open. Further, it is inevitable that the key groove portion 55 is inclined with respect to the gear and hits against the gear at the tip end, but in this case as well, in the thin closed cross-section structure, F2 is received not only in the vicinity of the key groove portion but also in the entire closed cross section. As a result, the bending rigidity becomes high, and the radial deformation of the key groove portion 55 is very small. Therefore, the bending stress σ1 also decreases. Therefore, the heating roller is slightly deformed as shown by the broken line 68 in the figure, and the gap L16
9 is greatly reduced.

As described above, in the structure of this embodiment, the heating roller 1 has a thin wall closed cross-section structure.
Shear force τ due to torque T and force resulting from gear pressure angle
1. Furthermore, bending stress σ due to the force caused by the gear pressure angle
As a result, the damage to the heating roller 1 and the fatigue damage to the heating roller 1 can be greatly improved, the occurrence of malfunctions such as inoperability of the apparatus can be reduced, and the mechanical reliability can be improved.

Further, because of the thin closed cross-section structure, the amount of elliptical deformation at the end of the heating roller 1 is small, the whirling of the heating roller 1 is reduced, and the conveyance speed of the object to be fixed (paper) does not change. Since stable fixing is possible, good print quality without image blurring, uneven fixing, and wrinkles can be achieved.

Since the heating roller 1 is little deformed and the gap is not increased, the convex portion (key portion) of the drive transmission means 7 is formed.
Wear of both 56 and the key groove 55 due to slippage is small.

Further, the key groove portion 55 is composed of a squeezing portion which is continuous with the outer peripheral surface of the heating roller 1 and has no opening portion. Since there is no edge portion, the convex portion (key portion) 56 of the drive transmission means 7 may be scraped off. Absent. Therefore, the stability of the drive transmission is ensured for a long period of time, the mechanical durability of the apparatus is improved, and the disturbance of the fixed image due to the rotation fluctuation of the heating roller 1, the unevenness of the fixing strength, the occurrence of wrinkles are reduced, and the printing is performed. Stabilized quality.

Further, since there is little slippage and there is no edge portion of the key groove portion 55 and it is arcuate, it does not get caught by the convex portion 56 of the drive transmission means 7, suppresses the generation of a large abnormal noise, and enhances the quietness performance of the device. .

Furthermore, abrasion resistance and quietness can be secured with a simple structure, and additional parts such as spacers and grease are not required, and the mechanical reliability of the device is improved.

Since the strength around the key groove portion 55 is large, it is not necessary to form a plurality of highly accurate cutouts for suppressing deformation, and if the key groove portion 55 is at one position in the circumferential direction, sufficient drive torque can be transmitted. Therefore, the heating roller 1 can be easily processed.

Further, in recent years, there is an increasing demand for lowering the power consumption of the image forming apparatus by operating the fixing device only during printing and stopping the fixing device during non-printing. In this case, it is necessary to raise the temperature of the heating roller 1 from a low temperature to a predetermined fixing temperature each time printing is started. Therefore, the thickness of the heating roller 1 should be reduced to a low heat capacity to shorten the warm-up time. Is required.

In the configuration of this embodiment, even a thin heating roller 1 having a thickness of less than 1 mm has sufficient strength and rigidity and can transmit drive, so that the heating roller 1 can be made thin and have a low heat capacity. , The warm-up time can be greatly shortened, and the speed of the device and power consumption have been reduced. On the other hand, the key groove portion 55 of the heating roller 1 is configured to be slightly longer in the roller axial direction than the convex portion 56 of the gear, which is the drive transmission means 7, in order to absorb thermal expansion. Further, since the key groove portion 55 is composed of a diaphragm portion which is continuous with the outer peripheral surface of the heating roller 1 and has no opening,
The high heat flow velocity of the heating means 3 inside the heating roller 1 never leaks from the cylindrical portion of the heating roller 1, and the leaked light heat is prevented from locally heating the photoconductor, the train wheel, the transfer means, etc. High-quality printing is achieved by reducing unevenness in transfer, uneven transfer, uneven feed speed, and image distortion, while preventing melt deformation of the plastic member and improving mechanical reliability.

Further, only the convex portion (key portion) of the gear, which is the drive transmission means made of heat-resistant plastic or the like, is directly heated by the photothermal flow rate from the heating means, so that the vicinity of the convex portion (key portion) becomes locally high in temperature. The gear is heated substantially uniformly by the heat conduction from the heating roller 1 without generating a uniform heat distribution. Therefore, the thermal deformation of the gear becomes uniform, and the heating roller 1
Since the rotation speed of was kept constant and the load change on the train wheel was small, good quality images were obtained without image distortion, uneven fixing, and wrinkles. Further, melting deformation and the like of the protruding portion (key portion) of the drive transmission means could be suppressed.

Next, processing of the heating roller 1 will be described.

As an example, the heating roller 1 is formed into a predetermined outer shape and inner diameter by drawing aluminum and cut into a predetermined length to finish the core metal. After that, both ends are centrally supported, and the outer periphery is cut or ground into a predetermined size or an inverted crown shape to finish the cored bar. next,
The key groove portion 55 is formed by continuous drawing with a press, the inner periphery is black-painted, and the outer periphery is coated with a heat-resistant release resin layer such as PTFE or PFA. At this time, since the key groove portion 55 is formed after cutting and finishing, the surface shape of the heating roller 1 can be formed into a free shape including a straight shape and an inverted crown, and since the center support is used, the deflection accuracy can be processed with good precision. Further, by optimizing the press die, the coaxiality between the central fixing area of the heating roller 1 and the end squeezed portion can be processed with high accuracy, and the roundness of the end squeezed portion can be improved. Can be processed.

Further, as compared with the conventional method in which the key groove (slit) is formed by milling or the like, only one press work is required, and deburring and cutting debris (cutting) processing are unnecessary. Processing time can be greatly reduced. Further, since there is no opening on the outer peripheral surface of the heating roller 1 when the inner surface is coated with black, laborious steps such as masking can be omitted and the cost can be further reduced.

As another example, after the core metal is laid out, the key groove portion 55 is pressed, and the inner surface is painted black,
If the outer circumference is centerless polished, the concentricity and roundness of the end portion and the central portion of the heating roller 1 are further improved, and the highly accurate heating roller 1 can be produced in a further process-saving process, and the processing time is further increased. A reduction was achieved.

FIG. 4 is an explanatory view of another embodiment of the heating roller of the heat fixing device of the present invention.

At the end portion of the heating roller 1, a part of the circumference of the heating roller 1 is displaced toward the center side, and a key groove portion 75 is formed by drawing into a D-character shape. On the other hand, the gear, which is the drive transmission means 7, has a D-shaped protrusion 76, which engages with the key groove 75, determines the relative position between the two, and transmits the rotational driving force. Further, the inner circumference of the drive transmission means 7 and the outer circumference of the heating roller 1 have substantially the same diameter, but since the fitting between them and the dimensional change due to thermal expansion are absorbed,
There is a slight gap.

In this case, the key groove portion 75 of the heating roller 1
Since the (concave portion) is formed by a D-shaped straight line, the drawing process is easy and the dimensional accuracy is easy to obtain.

Further, the gear and the heating roller 1 rotate with a gap, but both of them rotate by the gap, the rotation is stopped by the contact of the linear portion, and the driving force is transmitted. Therefore, wear due to slipping and catching of both is excellent, durability is excellent, and stable drive transmission is possible. Further, since no abnormal noise is generated, the quietness of the device is improved.

FIG. 5 is an explanatory view of another embodiment of the heating roller of the heat fixing device of the present invention.

At the end of the heating roller 1, a part of the circumference of the heating roller 1 is displaced toward the center side, and the recess 79 is formed by drawing into a D shape. On the other hand, the gear which is the drive transmission means 7 has a boss portion 77 integrated with the side surface portion, and the inner peripheral surface 80 is circular. The boss portion 79 is provided with a screw portion, and the set screw 78 is attached thereto. The set screw 78 fastens and fixes the concave portion 79 of the heating roller 1 to determine the relative position between the two and to transmit the rotational driving force. Although the inner circumference of the drive transmission means 7 and the outer circumference of the heating roller 1 have substantially the same diameter, a slight gap is provided between them in order to absorb the dimensional change due to fitting and thermal expansion.

The set screw 78 applies a large thrust to the concave portion of the heating roller 1. However, even if the heating roller 1 is thin, since it has a thin closed cross-section structure with no opening, the rigidity and strength are high and the generated stress is reduced. There was no damage or deformation, and mechanical reliability was improved. At the same time, elliptical deformation can be reduced and whirling can be eliminated, so that the conveyance speed of the object to be fixed is stable, and a high-quality image free from uneven fixing and wrinkles can be obtained.

FIG. 6 is an explanatory view of another embodiment of the heating roller of the heat fixing device of the present invention.

At the end portion of the heating roller 1, the outer peripheral surface 50 of the heating roller 1 is closer to the center 5 of the heating roller 1 than the outer peripheral surface 50.
The concave portion 81 and the concave portion 82 each have a surface continuously formed from the outer peripheral surface 50 which is displaced toward the fourth side.
At positions corresponding to Nos. 1 and 82, the inner peripheral surface 52 of the heating roller 1 has convex portions 83 and 84 which are displaced from the inner peripheral surface 52 toward the center 54 side of the heating roller 1 to form a key groove portion 85. ing.

In the case of this embodiment, the key groove portion 85 is formed by drawing and has a circumferential opening 86 and an axial opening 87. These openings 86 and 87 are provided to alleviate the stress at the time of the drawing process, so that the drawing process can be further simplified and high-precision processing can be performed even with a simple drawing die. Although the heating roller 1 has a thin open cross-section structure having an opening with respect to the outer peripheral surface 50, the concave portions 81 and 82 and the convex portion 8 are formed.
Since 3 and 84 reinforce the periphery of the opening as a flange of the opening 86, the heating roller 1 and the key groove portion 85 have high strength and high rigidity, and the breakage and the deformation are largely relieved.

Although not shown, the convex portion 56 (hereinafter referred to as a key portion) of the gear, which is the drive transmission means 7, engages with the key groove portion 85 to determine the relative position between the two and to transmit the rotational driving force. . Further, the drive transmission means and the outer peripheral surface 50 of the heating roller 1 have substantially the same diameter, but are provided with a gap required for fitting and absorbing a dimensional change due to thermal expansion.

FIG. 7 is a sectional view of still another embodiment of the heat fixing device of the present invention.

The heating roller 1 has a second surface 31 on the outer peripheral surface of the end portion.
And the first surface 3 of the inner peripheral surface of the cylindrical shaft 4 made of heat-resistant resin.
Mating with 2. The first surface 32 and the second surface 31 have substantially the same diameter, but a gap necessary for absorbing a dimensional change due to fitting and thermal expansion is provided, and the diameter of the second surface 31 is slightly smaller. Further, at the end of the heating roller 1, at least one portion of the outer peripheral surface has a concave portion displaced from the outer peripheral surface to the center side of the heating roller 1, and at the position corresponding to this, the inner peripheral surface of the heating roller 1 is A key groove portion 90 having a convex portion displaced to the center side from the peripheral surface is provided. The convex portion 91 (key portion) provided on the inner surface of the cylindrical shaft 4 which is the drive transmission means engages with the key groove portion 90, determines the relative position of the both, and transmits the driving force. The heating roller 1 and the cylindrical shaft 4 are fitted together at a fitting portion formed by the first surface 32 and the second surface 31, and rotate integrally. The outer peripheral surface of the cylindrical shaft 4 has a third surface 33 that is a sliding surface. With respect to the axial direction (longitudinal direction) of the cylindrical shaft 4, the third surface 33 is provided at a position where it at least partially overlaps the first surface 32.

A drive gear 92 for driving the cylindrical shaft 4 is fitted on the outer periphery of the cylindrical shaft 4 by means of a key or the like to transmit the rotation from the drive source to the cylindrical shaft 4. The fourth surface 3 which is a sliding surface of the support frame 6 of the fixing device is located at a position facing the third surface 33 of the cylindrical shaft 4.
4 is arranged, and the supporting frame 6 rotatably supports the cylindrical shaft 4 by the contact sliding of the third surface 33 and the fourth surface 34. Furthermore, the cylindrical shaft 4
On the outer periphery of the third surface 33, a fifth surface 35 is provided at a position different from the third surface 33 and sandwiching the drive gear 92. The support frame 6 is the fourth
The sixth surface 36 is provided at a position different from the surface and facing the fifth surface. The fifth surface and the sixth surface slide with each other to form a sliding surface.

The cylindrical shaft 4 has a cap shape having an opening. That is, the inner peripheral surface of the cylindrical shaft 4 is composed of the first surface 32 and the seventh surface 37. 7th surface 37 is 1st surface 3
2 is a surface 37a connected to the surface 2, a surface 37c that is substantially orthogonal to the surface 37b and an extension surface of the first surface 32, and a surface 37 that constitutes the opening
d.

The heating means 3 penetrates the opening formed by the surface 37d with a slight gap. Other configurations are the same as those of the embodiments described so far.

Since the heating roller 1 receives a large thrust force in the radial direction by a pressure roller (not shown), the key groove portion 90 of the heating roller 1 is pressed in addition to the axial force resulting from the driving torque and the gear pressure angle. A large pressure contact force from the roller acts. However, as described above, the end of the heating roller has a thin-walled closed cross-section structure, so it has sufficient strength and rigidity, prevents damage and fatigue damage, suppresses whirling due to deformation, and causes wear and damage due to slippage. It became possible to prevent noise.

Due to the surface 37c, the cylindrical shaft 4 has a cap structure and prevents the hot air inside the heating roller 1 and the leakage of the halogen lamp, which is the heating means 3, from leaking to the outside. Therefore, the thermal efficiency of the fixing device is further improved, and there is almost no high heat leakage from the inside of the heating roller 1 to the outside, and the leaked light heat is prevented from locally heating the photoconductor, the train wheel, the transfer means, etc. It realizes high quality printing by reducing unevenness of transfer, uneven transfer, uneven feeding speed and image distortion, and further prevents melting deformation of the plastic member and further improves mechanical reliability. Further, it is not necessary to add a cap component as a separate component to the outside of the halogen lamp, which contributes to downsizing and cost reduction of the fixing device.

FIG. 8 is an explanatory view of another embodiment of the drive transmission portion of the heat fixing device of the present invention.

At the end of the hollow cylindrical heating roller 1, the outer peripheral surface 50 of the heating roller 1 is continuous from the outer peripheral surface 50 which is displaced from the outer peripheral surface 50 to the center 54 of the heating roller 1 at one location. It has a convex portion 93 having a surface formed by the narrowed portion, and at a position corresponding to the convex portion 93,
The inner peripheral surface 52 of the heating roller 1 has a concave portion 94 which is displaced outward from the inner peripheral surface 52 with respect to the center 54 of the heating roller 1, and constitutes a diaphragm portion (key portion) 95.

In the case of the present embodiment, this diaphragm portion (key portion) 9
5 is formed by total drawing, and the convex portion 93 is formed on the heating roller 1.
The outer peripheral surface 50 has a continuous narrowed portion, and the outer peripheral surface 50 of the heating roller 1 has a thin wall closed cross-section structure with no opening.

On the other hand, at a position where it fits into the convex portion 93 of the heating roller 1, a concave portion (key groove portion) is formed in a part of the inner peripheral portion of the gear, which is the drive transmitting means 7, from the inner peripheral surface 97 toward the outside. ) 96 is formed, and the concave portion 96 of the drive transmission means 7 engages with the convex portion 93 of the heating roller 1 to determine the relative position between the two and to transmit the rotational driving force. Further, the drive transmission means 7 and the outer peripheral surface 50 of the heating roller 1 have substantially the same diameter,
A gap is provided for fitting and absorbing dimensional changes due to thermal expansion.

Although not shown, the heating roller 1 is rotated by a bearing while being supported by a support frame. The heating means is arranged so as to penetrate the hollow inside of the heating roller 1. The heating means 3 is supported by a support frame or a terminal fixed to the image forming apparatus, receives the supply of electric power to heat the heating roller 1, and controls the detection signal of the temperature sensitive element on the outer circumference of the heating roller 1. The heating roller 1 is maintained at a predetermined temperature necessary for melting the toner by controlling the input voltage to the heating means. Although not shown, the pressure roller is rotatably supported by bearings, and the heating roller 1 is fixed at least during fixing by a known pressure means.
To form a pressure contact portion with the heating roller.

Since the squeezing portion (key portion) 95 of the heating roller 1 is formed by the squeezing process, the convex portion 93 on the outer peripheral surface and the concave portion 94 on the inner peripheral surface can be configured to have substantially the same thickness as the other portions, The heating roller 1 has a thin closed cross-sectional structure with a substantially uniform thickness. Therefore, the heat capacity of the end portion of the heating roller 1 becomes uniform in the circumferential direction and the axial direction, and the temperature decrease at the end portion can be prevented, and
The thermal deformation due to the heat distribution was also suppressed, and good printing without fixing unevenness due to whirling, image blurring, and wrinkles could be realized.

Next, processing of the heating roller 1 shown in FIG. 7 will be described.

As an example, the heating roller 1 is formed into a predetermined outer diameter and inner diameter by drawing aluminum and cut into a predetermined length to finish the core metal. After that, both ends are centrally supported, and the outer periphery is cut or ground into a predetermined size or an inverted crown shape to finish the cored bar. Further, it may be finished by centerless polishing. Next, by pressing, the drawn portion (key portion) 95 is subjected to total drawing processing on a continuous surface, black coating is applied to the inner circumference, and a heat-resistant release resin layer such as PTFE or PFA is applied to the outer circumference. To do.

At this time, since the squeezing portion (key portion) 95 is formed after the cutting finish, the surface shape of the heating roller 1 is a straight shape, a free shape including an inverted crown, and the center support provides good runout accuracy. Is possible. Further, by optimizing the press die, the coaxiality between the central fixing area of the heating roller 1 and the end squeezed portion can be processed with high accuracy, and the roundness of the end squeezed portion can be improved. Can be processed. Therefore, there was no whirling of the heating roller 1, and a good image was obtained.

Further, in comparison with the conventional method in which the key had to be formed by milling or the like, only one press work was required, and deburring and cutting waste (grid) treatment were unnecessary. Processing time can be greatly reduced. In addition, since there is no opening on the outer periphery of the heating roller 1 when the inner surface is painted black, it is possible to save time and labor, and further reduce costs.

[0107]

As described above, according to the present invention, the heating roller has the concave portion or the convex portion formed by the squeezing portion having no opening and having the surface continuously formed from the outer peripheral surface. The drive transmission means has a convex portion or a concave portion corresponding to the concave portion or the convex portion of the heating roller formed in a part of the inner peripheral portion fitted to the outer peripheral surface of the heating roller. By being configured to engage with the convex portion or the concave portion of the drive transmission means, 1) leakage light heat from the concave portion or the convex portion of the heating roller to the periphery of the photoconductor, the transfer means, etc. is prevented, and a good image without unevenness is realized. In addition, deformation and melting and abnormal noise were prevented, and the mechanical reliability of the device was improved. Further, it is not necessary to add a special light-shielding means, which contributes to downsizing and cost reduction of the device.

2) In order to prevent light heat from directly hitting the concave portion or the convex portion of the heating roller to the convex portion or the concave portion of the driving force transmitting means engaging with the heating roller, the driving force transmitting means is uniformly heated and is not affected by the heat distribution. Uniform deformation was prevented, whirling of the heating roller was prevented, and good images were realized.

3) Since the heating roller has a thin-wall closed cross-section structure, shear stress and bending stress are relieved, damage to the concave portion or convex portion of the heating roller and fatigue damage are prevented, and the mechanical reliability of the device is greatly increased. Improved.

4) Since the heating roller has a thin wall closed cross-section structure, the rigidity of the heating roller is improved, whirling due to the deformation of the end portion is prevented, and a good image is realized.

5) Since the heating roller has a thin-wall closed cross-section structure, the heating roller is less deformed and the gap between the heating roller and the driving force transmitting means does not increase. Both wear due to slippage is small. Also, the concave portion or the convex portion of the heating roller is constituted by a diaphragm portion which is continuous with the outer peripheral surface of the heating roller and has no opening, and since there is no edge portion, the convex portion or the concave portion of the drive transmission means is not scraped off. Therefore, the stability of the drive transmission is ensured for a long period of time, the mechanical durability of the device is improved, and the disturbance of the fixed image due to the rotation fluctuation of the heating roller, the uneven fixing strength and the occurrence of wrinkles are reduced, and the print quality is improved. Stabilized.

6) Also, since there is little slippage and there is no concave or convex edge portion of the heating roller and it is arcuate, it does not get caught in the convex or concave portion of the drive transmitting means, and suppresses the generation of a large abnormal noise. Improved quietness.

Furthermore, abrasion resistance and quietness can be secured with a simple structure, and additional parts such as spacers and grease are not required, and the mechanical reliability of the device is improved.

7) Since the strength of the periphery of the concave portion or the convex portion of the heating roller is large, it is not necessary to form a plurality of highly accurate notches for suppressing the deformation, and the concave portion or the convex portion of the heating roller is 1 in the circumferential direction. It is possible to transmit sufficient drive torque at any number of locations, making it easy to process the heating roller.

8) Since the end portion of the heating roller has a thin wall closed cross-section structure, sufficient strength and rigidity can be realized even if a large radial thrust is applied to the end portion.

9) In 3) to 8), the wall thickness is 1
Even a thin heating roller with a thickness of less than mm has sufficient strength and rigidity and can transmit drive, so that the heating roller can be made thinner and the heat capacity can be reduced, and the warm-up time can be greatly shortened and the device speed can be increased. Realized low power consumption.

10) The concave or convex portions of the heating roller are formed by drawing such as pressing, deburring and cutting debris treatment, and masking at the time of coating are not required, and the number of processing steps and processing time are greatly reduced. It has become possible. In addition, the coaxiality between the end portion and the central portion is secured, and the whirling accuracy is improved.

11) Since the end portion of the heating roller is formed by drawing, the drawing portion can be configured to have substantially the same thickness as the other portions, and the heating roller has a thin-wall closed cross-section structure with substantially uniform thickness. Therefore, the heat capacity of the end portion of the heating roller becomes uniform in the circumferential direction and the axial direction, the temperature decrease at the end portion can be prevented, the thermal deformation due to the heat distribution can be suppressed, and the fixing unevenness due to whirling, image blurring, and wrinkles can be suppressed. Good print quality was realized.

It is particularly effective if the heat fixing device of the present invention is applied to a printer, a facsimile, and a copying machine.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an apparatus for explaining the overall configuration of an image forming apparatus equipped with a heat fixing device of the present invention.

FIG. 2 is an explanatory diagram of an embodiment of a drive transmission unit of the heat fixing device of the present invention.

FIG. 3 is an explanatory view for explaining deformation of a heating roller according to an embodiment of the present invention due to a load on a heating roller.

FIG. 4 is an explanatory view of another embodiment of the heating roller of the heat fixing device of the present invention.

FIG. 5 is an explanatory view of another embodiment of the heating roller of the heat fixing device of the present invention.

FIG. 6 is an explanatory view of another embodiment of the heating roller of the heat fixing device of the present invention.

FIG. 7 is a sectional view of still another embodiment of the heat fixing device according to the present invention.

FIG. 8 is an explanatory view of another embodiment of the drive transmission unit of the heat fixing device of the present invention.

FIG. 9 is an explanatory diagram of an example of a conventional heat fixing device.

FIG. 10 is an explanatory view showing a deformation of a heating roller of a conventional heat fixing device due to a load.

[Explanation of symbols]

 1 ... Heating roller 2 ... Emitting part 3 ... Heating means 4 ... Cylindrical shaft 6 ... Support frame 7 ... Driving gear 10 ... Pressure roller 11 ... Terminal 12 ... Foil 21 ... Recording paper 22 ... Feeding roller 24 ... Photoreceptor 26 ... Transfer roller 28 ... Charging roller 29・ ・ ・ Laser scanning optical system 30 ・ ・ ・ Developing roller 31 ・ ・ ・ ・ Second surface 32 ・ ・ ・ ・ First surface 33 ・ ・ ・ ・ Third surface 34 ・ ・ ・ ・ ・ ・ Fourth surface 35 ・ ・ ・・ ・ Fifth surface 36 ・ ・ ・ ・ Sixth surface 37 ・ ・ ・ ・ Seventh surface 40 ・ ・ ・ ・ Sliding bearings 42a, 42b ・ ・ ・ ・ Toner circulation transport path 44 ・ ・ ・ ・ ・ ・ Cleaning blade 50 ・ ・ ・・ Outer peripheral surface 51 ・ ・ ・ ・ Concave portion 52 ・ ・ ・ ・ ・ ・ Inner peripheral surface 53 ・ ・ ・ ・ Convex portion 54 ・ ・ ・ ・ Center 55, 75 ・ Key groove portions 56, 7 -Convex portion of drive transmission means 57 ... Inner peripheral surface of drive transmission means 60 ...- Opening portion 61 ...- Torque T 62 ... Force F 77 ... Boss portion 78 ... Set screw 79 Recess 80 Inner peripheral surface 81 82 Recess 83 83 Convex 85 Key groove 86 87 Open 93 Convex 94 ··· Recess 95 ··· Narrowed portion 96 ··· Recess of drive transmission means 97 ··· Convex portion of drive transmission 101 · · Key groove portion 102 · · Key portion 103 · · Row 104 ... Shading means

Claims (5)

[Claims] 1. A heating and fixing device comprising: a hollow cylindrical heating roller which is brought into contact with an unfixed image and heated by a heating means; and a drive transmission means which is fitted to an outer periphery of the heating roller. The outer peripheral surface has a recess having a surface continuously formed from the outer peripheral surface formed by displacing at least one portion from the outer peripheral surface toward the center side of the heating roller, and the drive transmission means includes A convex portion directed toward the center from the inner peripheral surface corresponding to the concave portion is formed in a part of the inner peripheral portion fitted to the outer periphery, and when the heating roller and the drive transmission means are fitted, the concave portion and the A heating and fixing device characterized in that the convex portions are engaged with each other. 2. The heat fixing device according to claim 1, wherein the concave portion is a narrowed portion formed on the heating roller. 3. The heat fixing device according to claim 2, wherein the recess has no opening with respect to the outer periphery of the heating roller. 4. A heating and fixing device comprising: a hollow cylindrical heating roller which is brought into contact with an unfixed image and heated by a heating means; and a drive transmission means which is fitted to the outer periphery of the heating roller. The outer peripheral surface of at least one portion has a convex portion having a surface formed by a squeezing portion continuous from the outer peripheral surface, the convex portion being displaced outward from the outer peripheral surface with respect to the center of the heating roller, and the drive transmission means. In a part of the inner peripheral portion fitted to the outer periphery of the heating roller, a concave portion is formed corresponding to the convex portion, the concave portion facing outward from the inner peripheral surface toward the center,
A heating and fixing device characterized in that the convex portion and the concave portion are engaged with each other when the heating roller and the drive transmission means are fitted to each other. 5. The heat fixing device according to claim 4, wherein the convex portion has no opening with respect to the outer periphery of the heating roller.