JPH10240058A - Thermal fixing roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal fixing roller capable of being reused by coupling a flange part and the cylindrical part by means of plasma melt-sticking, and approximately equalizing the thickness of this coupling section to the thickness of the cylindrical part. SOLUTION: This thermal fixing roller 10 is provided with the flange part 12 and the cylindrical part 11, and respective thickness of the cylindrical part 11 and a cylindrical section 12a of the flange part 12 are equal to each other. In each inner periphery at both end parts of the cylindrical part 11, annular notched part 11a is formed, and on each outer periphery on the cylindrical section 12a of the flange section 12, annular notched part 12b is formed. By coupling by means of force-fitting the annular notched part 12b on the flange section 12 into the annular notched part 11a in the cylindrical part 11, the flange section 12 and the cylindrical part 11 are joined by means of plasma welding on the respective periphery thereof. At this time, the several thickness of joint section 13 is approximately made equal to the cylindrical part 11. In such a manner, heat energy transmitted from a heater inside the cylindrical part 11 is average over the whole thermal fixing roller, therefore the temp. distribution is uniformized on the whole thermal fixing roller area, and the efficiency is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat fixing roller used in an image forming apparatus such as a copying machine.

[0002]

2. Description of the Related Art Conventionally, this type of heat fixing roller has been used in an electronic copying machine to fix an image obtained by transferring toner onto transfer paper or the like in a copying process by heat or the like. This heat fixing roller has a structure in which a flange portion and a cylindrical portion are divided, and the flange portion and the cylindrical portion are integrally joined by a friction welding method.

[0003]

Thus, when the flange portion and the cylindrical portion are friction-welded, the contact surface between the flange portion 100 and the cylindrical portion 101 is different as shown in FIG. Then, a difference occurs in the molten state between the flange portion 100 and the cylindrical portion 101, resulting in poor pressure contact. As a countermeasure against the poor pressure contact, for example, as shown in FIG. 15, the contact area between the flange portion 100 and the cylindrical portion 101 is made the same and the thickness is reduced. It will be good. However, since the thickness of the pressure contact portion 102 is different from the thickness of the other portions of the cylindrical portion 101, the roller surface temperature between the pressure contact portion 102 and the other cylindrical portion 101 becomes uneven. Further, in the friction welding, burrs are generated on the inner surface side and the surface side of the pressing surface as shown in FIG.
Since the burrs 100a and 101a on the front side are in contact with the fixing pressure contact roller disposed opposite to the heat fixing roller and serve as a sheet passing surface of the transfer paper, the burrs 100a and 101a on the front side are provided.
Post-processing is required to remove, and this post-processing is also required on the right side of FIG. Further, in the friction welding, since the pressure contact surface is melted, the dimension in the axial direction of the cylindrical portion may vary, so that a predetermined size is obtained by finishing with a margin in anticipation of a dimensional change in which the pressure contact portion 102 is shortened. The both sides of the flange portion 100 are post-processed.

In the friction welding method, as shown in a friction welding process in FIG. 17, a flange 2 is formed as shown in FIG.
00 is attached to a main shaft such as a lathe and rotated at a high speed, and the cylindrical portion 201 is pressed against the flange portion 200.
When the contact portion between the flange portion 200 and the cylindrical portion 201 is rubbed, and both are in a molten state due to frictional heat, the flange portion 200
When the rotation of the cylinder is stopped, the flange portion 200 and the cylindrical portion 201
Are pressed. As shown in FIG.
Is removed from the main shaft, the other flange portion 200 is attached to the main shaft and rotated, and the opposite side of the pressed cylindrical portion 201 is similarly pressed and pressed. Since burrs are generated on the inner surface side and the front surface side of the press-contact portion 202 after the press-contact, and the center of the flange portion 200 and the cylindrical portion 201 are misaligned, external processing is required as shown in FIG. Further, the outer diameter of the support shaft portion is damaged because the shaft support portion 200a of the flange portion 200 is tightly chucked to the main shaft, and this also requires post-processing. Furthermore,
Since a force is applied in the axial direction of the cylindrical portion at the time of pressure welding, the dimension in the axial direction of the cylindrical portion is shortened and changes. Therefore, the dimensions are given with a margin in advance, so that a process of finishing to a predetermined size is required. Even if friction welding is performed on the flange portion 200 with aluminum metal using a stainless material having relatively low thermal conductivity and excellent wear resistance of the shaft support portion 200a, the melting point is different between stainless steel and aluminum, so the pressed state is performed. Is incomplete and cannot be used.

Further, as shown in FIGS. 18 and 19, the surface temperature in the longitudinal direction of the heat fixing roller 300 is lower at both ends than at the center due to heat radiation from the end. In particular, since a drive gear 301 and other components are attached to the drive-side end of the heat fixing roller 300, the surface temperature of the drive-side end is t1, and the surface temperature of the bearing 302 is lower than t2. As a method of increasing the surface temperature at both ends, there is a method of making the arrangement of the filaments at both ends of the heater lamp 303 dense and increasing the light emission amount to make the surface temperature in the axial direction of the cylindrical portion uniform. However, when the light emission amount at both ends of the heater lamp 303 is increased, the temperature of the sealing portion at the end of the heater lamp 303 increases, and cracks and the like occur in the sealing portion, thereby shortening the life of the heater lamp 303.

The present invention has been made in view of such circumstances, and the invention according to claims 1 to 4 is a heat-fixing roller used in a fixing device for thermally fixing toner on a recording medium. The surface temperature in the axial direction of the cylindrical portion of the heat-fixing roller has been made uniform, and the flange portion with severe wear has been replaced as a rotary bearing, allowing the cylindrical portion to be reworked. It is an object of the present invention to provide a heat fixing roller that can be reused as a roller.

Further, according to the present invention, it is possible to improve the durability of the heat fixing roller, expand the material use range of the heat fixing roller, and reduce the manufacturing cost. It is an object of the present invention to provide a heat-fixing roller.

According to the present invention, the surface temperature of the heat fixing roller in the axial direction of the cylindrical portion can be made uniform, the warm-up time of the heat fixing roller can be reduced, and the time of continuous copying can be improved. It is an object of the present invention to provide a heat fixing roller capable of increasing the heat capacity of the heat fixing roller for preventing the surface temperature of the heat fixing roller from lowering.

[0009]

In order to solve the above-mentioned problems and achieve the object, the invention according to claim 1 is directed to a heat fixing roller having a flange portion and a cylindrical portion having a substantially constant thickness. The flange portion and the cylindrical portion are joined by plasma welding, and the thickness of the joined portion is substantially equal to the thickness of the cylindrical portion. Since the thickness of the cylindrical portion is constant, the thermal energy transmitted from the heater inside the cylindrical portion is averaged over the entire heat fixing roller, and the temperature distribution becomes uniform over the entire area of the heat fixing roller, thereby improving the efficiency. In addition, there is almost no burr generated by the plasma welding of the flange portion and the cylindrical portion, and the finishing process is not required or is greatly reduced. In addition, the dimensional change due to the joining is almost eliminated by the plasma welding, and a high-precision heat-fixing roller base can be obtained by a simple processing step.

The invention according to claim 2 is characterized in that the joining portion is joined by plasma welding on the outer peripheral surfaces of the flange portion and the cylindrical portion. When the flange of the flange wears, the joint between the flange and the outer surface of the cylinder is cut and the flange is replaced, and the cylinder is reworked and plasma-welded again to enable reuse of the cylinder. Become.

The invention according to claim 3 is characterized in that the thickness gauge of the flange portion and the cylindrical portion of the joint is equal to the thickness of the cylindrical portion. A uniform temperature distribution is obtained over the entire area of the heat fixing roller, and the efficiency is improved.

According to a fourth aspect of the present invention, there is provided a heat fixing roller in which the thickness of the cylindrical portion is constant, both ends of the cylindrical portion have a reduced inner diameter, and a flange portion is press-fitted to this portion. The side end portion, which is the joining portion between the cylindrical portion and the flange portion, is plasma-welded. By plasma welding the side edges, finishing is not required or is greatly reduced.

The invention according to claim 5 is characterized in that the flange portion and the cylindrical portion made of a different kind of metal or a similar kind of metal are integrated by plasma welding. Since a metal having excellent wear resistance can be used for the flange portion, the durability as a heat fixing roller is improved. In addition, it is possible to use various kinds of metals, thereby expanding the range of materials used for the heat fixing roller and reducing the manufacturing cost.

The invention according to claim 6 is characterized in that the thickness of the cylindrical portion is substantially equal to the thickness of the welded portion. The heat energy transmitted from the heater inside the cylinder is averaged over the entire heat fixing roller, so that a uniform temperature distribution is obtained over the entire area of the heat fixing roller, and the efficiency is improved.

The invention according to claim 7 is characterized in that the flange portion is made of stainless steel. Since a stainless metal having excellent wear resistance can be used for the flange portion, the durability as a heat fixing roller is improved.

The invention according to claim 8 is characterized in that the cylindrical portion is made of aluminum or an aluminum alloy. When the cylindrical portion is made of aluminum or an aluminum alloy, the cylindrical portion can be reused, and the manufacturing cost of the heat fixing roller is reduced.

According to a ninth aspect of the present invention, there is provided a heat fixing roller having a flange portion and a cylindrical portion, wherein the axial direction of the cylindrical portion is divided into a central portion and both end portions by plasma welding. It is characterized by being integrated. Compared to the conventional friction welding method, there is no change in the axial direction of the cylindrical part after welding, the bulge of the cylindrical part after welding is small, and the number of man-hours for finishing the post-processing is small, and it is suitable for welding. The time required can be greatly reduced.

According to a tenth aspect of the present invention, a plurality of ribs are formed in the cylindrical portion in an axial direction of the cylindrical portion, and the shapes of the plurality of ribs are changed between the central portion and the both end portions. And The temperature distribution in the longitudinal direction of the cylindrical portion is made uniform by the plurality of ribs. Further, the ribs increase the volume of the heat fixing roller itself and increase the heat capacity, so that a decrease in the surface temperature of the heat fixing roller during continuous copying is reduced. Further, the warm-up time is shortened because the rib inside the cylindrical portion is located close to the heater lamp.

According to an eleventh aspect of the present invention, the ribs at both ends extend in the center direction of the cylindrical portion as compared with the ribs at the center. The temperature distribution in the longitudinal direction of the cylindrical portion becomes uniform by extending the ribs at both ends where the temperature drop is large toward the center of the cylindrical portion as compared to the rib at the center.

The twelfth aspect of the present invention is characterized in that the central part and both ends divided into three parts before the plasma welding are joined by press fitting. By press-fitting the central part and the both ends divided into three, the positioning is reliable and the work of plasma welding is easy.

According to a thirteenth aspect of the present invention, the joint portion between the ribs at both ends and the center rib of the three-part cylindrical portion is formed in a gentle straight line or curved shape from the center to the both ends. The height of the ribs extends toward the shaft support portions at the both ends. The temperature distribution in the longitudinal direction of the cylindrical portion is made uniform by the plurality of ribs.

According to a fourteenth aspect of the present invention, the ribs on one driving side of the both end portions have a larger volume of the ribs than the ribs on the opposite side by increasing the number of velbs or extending the height of the ribs. It is characterized by many things. The drive-side end of the heat-fixing roller is equipped with parts such as drive gears.
Although the surface temperature is lower than that of the bearing, the heat capacity is increased, so that the surface temperature of the heat fixing roller during continuous copying is less reduced.

The invention according to claim 15 is characterized in that ribs are provided only at the both ends. The ribs make the temperature distribution in the longitudinal direction of the cylinder uniform, and the provision of the ribs only at both ends lowers the manufacturing cost of the cylinder.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a heat fixing roller according to the present invention will be described below with reference to the accompanying drawings. First, an embodiment of the heat fixing roller according to claims 1 to 4 will be described.

FIG. 1 is an explanatory diagram of plasma welding of a heat fixing roller. The support device for the heat fixing roller 10 has a spindle center 1 and a tailing shaft center 2, and the heat fixing roller 10 is mounted on the spindle center 1 and the tailing shaft center 2. The heat fixing roller 10 has a cylindrical portion 11 and flange portions 12 positioned on both sides of the cylindrical portion 11.

At both ends of the heat-fixing roller 10, a U-shaped high-frequency heating device 3 is arranged. The high-frequency heating device 3 operates, and the rotation of the main shaft center 1 of the supporting device causes the heat-fixing roller 10 to rotate. Is rotated about 50 to 200 rpm. The heat fixing roller 10 includes a cylindrical portion 11 and a flange portion 1.
2 is heated to about 280 to 350 ° C. Thereafter, the number of rotations of the heat fixing roller 10 is reduced by 0.5 to 5 r.
pm, a plasma arc is generated from the welding torch 4, and the joint between the cylindrical portion 11 and the flange portion 12 is welded. The plasma welding is completed in a process in which the heat fixing roller 10 makes one rotation.

The plasma welding used in the embodiment of the heat fixing roller 10 of the present invention will be described with reference to FIG. FIG. 2 is a principle diagram of the plasma welding apparatus. The plasma welding device 30 includes a line 32 connected to one end of a power source 31.
The high frequency generator 33 and the tungsten electrode 40 of the welding torch 4 are electrically connected to each other, and the line 34 connected to the other end of the power supply 31 is electrically connected to the heat fixing roller 10 as a base material. A high-frequency bypass capacitor C is connected to the lines 32 and 34, and is in parallel with the power supply 31. Further, a resistance R is connected between the welding torch 4 and the line 324.

In the welding torch 4, a cooling water passage 42 is formed in the torch main body 41, and cooling water is supplied to the cooling water passage 42. A plasma nozzle 43 is formed at the tip of the torch main body 41, and a shielding nozzle 44 is formed on the outer periphery of the plasma nozzle 43. When the gas passes through the heat source of the discharge arc by the tungsten electrode 40, the heat causes the gas atoms to emit electrons. This state is called plasma (ultra-high temperature gas). The plasma welding apparatus 30 water-cools the discharge arc and squeezes it to the limit with the plasma nozzle 43. When the argon gas is passed through the high-temperature arc, a plasma state is created. This heat source is a linear heat source accompanied by a plasma airflow having a much higher heat concentration than other welding methods, and has a high deep permeability, a narrow welding width, a small heat influence on the material, and a stable welding with little distortion.

For welding aluminum, aluminum alloys, etc., alternating current is used, the weld is cleaned with a reverse current, and penetration is increased with a positive current. Plasma welding of the heat fixing roller 10 performed in the embodiment of the present invention is performed by using a cylindrical portion 11 and a flange portion 12 made of aluminum metal.
The aluminum metal heat-fixing roller 10 is heated from the outside to the vicinity of the melting point of the aluminum metal by means of high-frequency heating or the like in a state where the joining portions of the aluminum metal are joined and butted, and the aluminum metal is slowly rotated while the aluminum metals are slowly rotated. Irradiate the plasma arc to the bonding and butting part,
The two metals are fused and welded by the arc heat.

Heat fixing roller 1 utilizing plasma welding
In the production of No. 0, there is little change in the dimension of the heat fixing roller 10 in the axial direction and the external direction, there is no deformation such as burrs of the welded portion, and there is no dimensional change or deformation as compared with the conventional friction welding method. Therefore, there are excellent points such as little post-processing and a short overall processing time, and the welding conditions are not so affected by the shape of the cylindrical portion 11 and the shape of the flange portion 12 of the heat fixing roller 10.

FIGS. 3 to 8 show an embodiment of the heat fixing roller. FIG. 3 shows a coupling state between the cylindrical portion 11 and the flange portion 12 of the heat fixing roller 10. The heat fixing roller 10 has a flange portion 12 and a cylindrical portion 11, and the cylindrical portion 11 and the cylindrical portion 12a of the flange portion 12 have the same thickness. At both ends of the cylindrical portion 11, a notch annular 11a is formed on the inner periphery.
Is formed, and a notched annular portion 12b is formed on the outer periphery of the cylindrical portion 12a of the flange portion 12. Notched ring 11a of cylindrical part 11 and notched ring 12b of flange 12
The flange portion 12 and the cylindrical portion 1
The outer peripheral surface 1 is joined by plasma welding.

FIG. 4 shows a connection state of the cylindrical portion 11 and the flange portion 12 of the heat fixing roller 10 according to another embodiment. In this embodiment, both ends of the cylindrical portion 11 and the ends of the flange portion 12 abut against each other so that the flange portion 12
Are joined by plasma welding on the outer peripheral surface.

As described above, in the embodiment of FIGS. 3 and 4, the flange portion 12 and the cylindrical portion 11 are joined by plasma welding, and the thickness of the joint portion 13 is made substantially equal to the thickness of the cylindrical portion 11. Since the thickness of the cylindrical part is constant, the thermal energy transmitted from the heater inside the cylinder is averaged over the entire heat fixing roller, resulting in a uniform temperature distribution over the entire area of the heat fixing roller, improving efficiency. I do. Also, the plasma welding of the flange portion 12 and the cylindrical portion 11 hardly generates burrs due to the joining, so that finishing work is not required.
Significantly reduced. In addition, the dimensional change due to the joining is almost eliminated by the plasma welding, and a high-precision heat-fixing roller base can be obtained by a simple processing step.

FIG. 5 shows a connection state of the cylindrical portion 11 and the flange portion 12 of the heat fixing roller 10 according to still another embodiment. This embodiment is configured in the same manner as the embodiment of FIG. 3 except that a cylindrical portion is not formed in the flange portion 12 and an annular protrusion 12c is formed in the flange portion 12, and a portion of the cylindrical portion 11 is formed. Is getting longer. The notch ring 11a of the cylindrical portion 11 is connected to the annular protrusion 12c to form the flange 1
2 and the outer peripheral surface of the cylindrical portion 11 are joined by plasma welding.

FIG. 6 shows a connection state of the cylindrical portion 11 and the flange portion 12 of the heat fixing roller 10 according to still another embodiment. At both ends of the cylindrical portion 11, a notch annular
Is formed by press-fitting the outer periphery of the flange portion 12 into the notched annular portion 11b so that the outer periphery of the flange portion 12 extends into the notched annular portion 11b. In this case, the welded portion 13 is not an outer peripheral surface but a side end portion.

As described above, the thickness of the cylindrical portion 11 is constant,
Both ends of the cylindrical portion 11 are reduced in inner wall thickness, and a flange portion 12 is press-fitted and joined to this portion, and a side end, which is a joint portion 13 between the cylindrical portion 11 and the flange portion 12, is plasma-welded. Therefore, the plasma processing of the side edges eliminates or greatly reduces the need for finishing.

FIGS. 7 and 8 show an embodiment in which the cylindrical portion 11 of the heat fixing roller 10 is reused. The joining portion 13 shown in FIGS. 7 and 8 is cut by a cutting machine 14 and divided into a flange portion 12 and a cylindrical portion 11. Cylindrical part 11
, The surface of the roller, such as Teflon coating, is peeled off, and the flange 12 uses a new part.

In order to join the cylindrical portion 11 and the flange portion 12, both ends of the cylindrical portion 11 are formed with notches 11a on the inner periphery. The flange portion 12 is finished to be longer to compensate for the reduced axial size of the cylindrical portion 11 for cutting. If the dimension of the cylindrical portion 11 in the axial direction of the cylindrical portion is not formed as required, the end of the flange portion 12 is post-processed.

As described above, the joint 13 is formed by the flange 1
2 and the outer peripheral surface of the cylindrical portion 11 are joined by plasma welding. When the shaft support portion 12d of the flange portion 12 is worn, the joint portion 13 between the outer peripheral surface of the flange portion 12 and the outer peripheral surface of the cylindrical portion 11 is cut to form the flange portion 12. After replacement, the cylindrical portion 11 is reworked and plasma-welded again, so that the cylindrical portion 11 can be reused.

Next, the heat fixing roller 10 according to claims 5 to 8 will be described. In each of the embodiments shown in FIGS. 3 to 8, the heat fixing roller 10 includes a flange portion 12,
The flange portion 12 and the cylindrical portion 11 made of a dissimilar metal or a dissimilar metal are integrated by plasma welding.
The flange portion 12 is a member supported by a bearing,
Since a metal having excellent wear resistance can be used, the durability as the heat fixing roller 10 is improved. In this embodiment, since the flange portion 12 is made of stainless steel, and the flange portion 12 can be made of stainless steel having excellent wear resistance, the durability of the heat fixing roller 10 is improved.
Further, when the cylindrical portion 11 is made of aluminum or an aluminum alloy and the cylindrical portion 11 is made of aluminum or an aluminum alloy, the cylindrical portion 11 can be reused, and the manufacturing cost of the heat fixing roller 10 is reduced.

With the joint between the cylindrical portion 11 made of aluminum metal and the flange portion 12 made of stainless steel joined and butted, the heat fixing roller 10 is heated from the outside to the vicinity of the melting point of the metal by means such as high-frequency heating. In addition, a plasma arc is irradiated to the joining and abutting portions while being slowly rotated with residual heat, and both metals are fused and welded by the arc heat to be integrated. The flange portion 12 is a member supported by a bearing, and a metal having excellent wear resistance can be used. Therefore, the durability of the heat fixing roller 10 is improved. In addition, the use of various metals becomes possible by plasma welding, and the range of materials used for the heat fixing roller is expanded.
And the manufacturing cost is reduced.

Further, the cylindrical portion 11 and the welded portion 13 are formed so as to have substantially the same thickness by plasma welding, and the heat energy transmitted from the heater inside the cylinder is transferred to the heat fixing roller 10.
The temperature is averaged as a whole, and a uniform temperature distribution is obtained over the entire area of the heat fixing roller 10, so that the efficiency is improved.

Next, the heat fixing roller 10 according to the ninth to fifteenth aspects will be described. Heat fixing roller 10
Has a flange portion 12 and a cylindrical portion 11, and the cylindrical portion 11
The axial direction of the cylindrical portion is divided into a central portion 110 and both end portions 111. The embodiment shown in FIGS. 9 and 10 will be described. FIG. 9 shows a state before plasma welding, and FIG. 10 shows a state after plasma welding. At both ends of the central portion 110 of the cylindrical portion 11, notched annular portions 110 a are formed at the inner periphery, and at the inner ends of both end portions 111, a notched annular portion 111 a is formed at the outer periphery. The annular portion 110a and the cut-out annular portions 111a at both ends 111 are joined, and the central portion 110 and the both ends 111, which are divided into three, are joined by plasma welding to be integrated. Both ends 111
A notch annular 111b is formed on the inner periphery at the outer end of
The outer periphery of the flange portion 12 is joined to the notched annular portion 111b by plasma welding in advance. Central part 1 divided into three
By press-fitting the 10 and both ends 111, the positioning is reliable and the work of plasma welding is easy.

A plurality of ribs 112 are formed in the cylindrical portion 11 in the axial direction of the cylindrical portion.
2a and a plurality of ribs 1
Twelve shapes are changed.

In the embodiment shown in FIG. 11, the height of the rib 112a at the center 110 of the cylindrical portion 11 is the same as the height 112b1 of the rib 112b at both ends 111. Thus, in the embodiment of FIGS. 9 to 11, 3
Ribs and central portions 11 at both ends 111 of the divided cylindrical portion 11
The joint portion with the rib 112 is a gentle straight line or curved shape from the center portion 110 side to both end portions, and the height of the rib 112 extends toward the axial support portion of both end portions 111, and a plurality of ribs are formed. 112 makes the temperature distribution in the longitudinal direction of the cylindrical portion uniform.

The ribs 112b at both ends 111 extend toward the center of the cylindrical portion compared to the ribs 112a at the central portion 110, and the ribs 112b located outside the inside of the cylindrical portion 11 are closer to the heater lamp. , The temperature drop is large outside the inside of the cylindrical portion 11, but the plurality of ribs 112 make the temperature distribution in the longitudinal direction of the cylindrical portion uniform.

In the embodiment shown in FIG. 12, a rib 112b is provided only at both end portions 111 without providing a rib at the central portion 110 of the cylindrical portion 11. Thus, both ends 11
1 is provided with a rib 112b so that the temperature distribution in the longitudinal direction of the cylindrical portion becomes uniform and
By providing the ribs 112b only on the base 11, the manufacturing cost of the cylindrical part 11 can be reduced.

As described above, in the embodiment shown in FIGS. 9 to 12, the plurality of ribs 112 make the temperature distribution in the longitudinal direction of the cylindrical portion uniform. Further, the volume of the heat fixing roller 10 itself increases due to the rib 112, and the heat capacity increases, so that a decrease in the surface temperature of the heat fixing roller during continuous copying is reduced. Further, the warm-up time is shortened because the rib 112 inside the cylindrical portion 11 is located close to the heater lamp.

In the embodiment shown in FIG. 13 (a), the ribs 112b on one driving side of the both end portions 111 have a larger number of velves than the ribs 112b on the opposite side. In the embodiment of FIG. 13B, the rib 112b on one driving side of the both ends 111 has a larger volume of the rib portion than the rib 112b on the opposite side by increasing the height of the velve. . The drive-side end of the heat-fixing roller 10 has components such as drive gears attached to it, so that the surface temperature is lower than that of the bearing, but the heat capacity increases, so the surface temperature of the heat-fixing roller decreases during continuous copying. Is reduced.

[0050]

As described above, according to the first aspect of the present invention, since the thickness of the cylindrical portion is constant, the heat energy transmitted from the heater inside the cylindrical portion is averaged over the entire heat fixing roller, and the heat A uniform temperature distribution is obtained over the entire area of the fixing roller, and the efficiency is improved. In addition, there is almost no burr generated by the plasma welding of the flange portion and the cylindrical portion, and the finishing process is not required or is greatly reduced.
In addition, the dimensional change due to the joining is almost eliminated by the plasma welding, and a high-precision heat-fixing roller base can be obtained by a simple processing step.

According to the second aspect of the present invention, when the shaft supporting portion of the flange portion is worn, the joining portion between the flange portion and the outer peripheral surface of the cylindrical portion is cut to replace the flange portion. By doing so, the cylindrical portion can be reused.

According to the third aspect of the present invention, a uniform temperature distribution is obtained over the entire area of the heat fixing roller, and the efficiency is improved.

According to the fourth aspect of the present invention, by performing the plasma welding on the side end portions, the finishing is not required or is greatly reduced.

According to the fifth aspect of the present invention, since a metal having excellent wear resistance can be used for the flange portion, the durability as a heat fixing roller is improved. In addition, it is possible to use various kinds of metals, thereby expanding the range of materials used for the heat fixing roller and reducing the manufacturing cost.

According to the sixth aspect of the present invention, the thermal energy transmitted from the heater inside the cylinder is averaged over the entire heat fixing roller, and the temperature distribution becomes uniform over the entire area of the heat fixing roller, thereby improving the efficiency.

According to the seventh aspect of the present invention, since stainless steel having excellent wear resistance can be used for the flange portion, the durability as a heat fixing roller is improved.

According to the eighth aspect of the invention, since the cylindrical portion is made of aluminum or an aluminum alloy, the cylindrical portion can be reused, and the manufacturing cost of the heat fixing roller is reduced.

According to the ninth aspect of the present invention, the axial direction of the cylindrical portion is divided into a central portion and both end portions, which are joined by plasma welding to be integrated, thereby reducing the frictional welding method compared to the conventional friction welding method. There is no dimensional change in the axial direction of the cylindrical part after welding, and the bulge of the cylindrical part after welding is small, so that the number of man-hours for finishing the post-processing is small, and the time required for welding can be greatly saved.

According to the tenth aspect of the present invention, since the plurality of rib shapes are changed at the center and both ends of the cylindrical portion, the temperature distribution in the longitudinal direction of the cylindrical portion becomes uniform. Further, the ribs increase the volume of the heat fixing roller itself and increase the heat capacity, so that a decrease in the surface temperature of the heat fixing roller during continuous copying is reduced. Further, the warm-up time is shortened because the rib inside the cylindrical portion is located close to the heater lamp.

According to the eleventh aspect of the present invention, the ribs at both ends where the temperature drop is large are extended toward the center of the cylindrical portion as compared with the rib at the center, so that the temperature distribution in the longitudinal direction of the cylindrical portion becomes uniform.

According to the twelfth aspect of the present invention, since the central portion and the both end portions divided into three are press-fitted, the positioning is reliable and the plasma welding work is easy.

According to the thirteenth aspect of the present invention, since the height of the rib extends toward the axial support portions at both ends, the temperature distribution in the longitudinal direction of the cylindrical portion is made uniform by the plurality of ribs.

According to the fourteenth aspect of the present invention, the ribs on the driving side increase the number of velbs relative to the ribs on the opposite side or increase the volume of the ribs by increasing the height of the ribs. Is prevented from lowering than the bearing side, and the heat capacity is increased, so that the decrease in the surface temperature of the heat fixing roller during continuous copying is reduced.

According to the fifteenth aspect, the ribs make the temperature distribution in the longitudinal direction of the cylindrical portion uniform, and the provision of the ribs only at both ends lowers the manufacturing cost of the cylindrical portion.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of plasma welding of a heat fixing roller.

FIG. 2 is a principle view of a plasma welding apparatus.

FIG. 3 is a diagram illustrating an embodiment of a heat fixing roller.

FIG. 4 is a diagram illustrating an embodiment of a heat fixing roller.

FIG. 5 is a diagram illustrating an embodiment of a heat fixing roller.

FIG. 6 is a diagram illustrating an embodiment of a heat fixing roller.

FIG. 7 is a diagram illustrating an embodiment of a heat fixing roller.

FIG. 8 is a diagram illustrating an embodiment of a heat fixing roller.

FIG. 9 is a diagram illustrating an embodiment of a heat fixing roller.

FIG. 10 is a diagram illustrating an embodiment of a heat fixing roller.

FIG. 11 is a diagram illustrating an embodiment of a heat fixing roller.

FIG. 12 is a diagram illustrating an embodiment of a heat fixing roller.

FIG. 13 is a diagram illustrating an embodiment of a heat fixing roller.

FIG. 14 is a view showing a conventional heat fixing roller.

FIG. 15 is a view showing a conventional heat fixing roller.

FIG. 16 is a view showing a conventional heat fixing roller.

FIG. 17 is a diagram illustrating a manufacturing process of a conventional heat fixing roller.

FIG. 18 is a view showing a conventional heat fixing roller.

FIG. 19 is a diagram showing the surface temperature of a conventional heat fixing roller.

[Explanation of symbols]

 10 Heat fixing roller 11 Cylindrical part 12 Flange part 13 Joining part

Claims (15)

[Claims] 1. A heat fixing roller having a flange portion and a cylindrical portion having a substantially constant thickness, wherein said flange portion and said cylindrical portion are joined by plasma welding, and said joint portion has a thickness of said cylindrical portion. A heat fixing roller having a thickness substantially equal to the thickness of the heat fixing roller. 2. The heat fixing roller according to claim 1, wherein said joining portion is joined by plasma welding on an outer peripheral surface of said flange portion and said cylindrical portion. 3. The heat fixing roller according to claim 1, wherein a thickness gauge of the flange portion and the cylindrical portion of the joining portion is equal to a thickness of the cylindrical portion. 4. A heat fixing roller in which the thickness of the cylindrical portion is constant, the inner diameter is reduced at both ends of the cylindrical portion, and the flange portion is press-fitted to this portion. A heat fixing roller characterized in that a side end portion, which is a joint portion with a flange portion, is plasma-welded. 5. A heat-fixing roller wherein a flange portion and a cylindrical portion made of a dissimilar metal or a dissimilar metal are plasma-welded to and integrated with the flange portion. 6. A heat fixing roller according to claim 5, wherein said cylindrical portion and said welded portion have substantially the same thickness. 7. A heat fixing roller according to claim 5, wherein said flange portion is made of stainless steel. 8. The heat fixing roller according to claim 5, wherein said cylindrical portion is made of aluminum or an aluminum alloy. 9. A heat fixing roller having a flange portion and a cylindrical portion, wherein the axial direction of the cylindrical portion is divided into a central portion and both end portions by plasma welding and integrated. Characteristic heat fixing roller. 10. A structure according to claim 9, wherein a plurality of ribs are formed in the cylindrical portion in the axial direction of the cylindrical portion, and the shapes of the plurality of ribs are changed between the central portion and the both end portions. Heat fixing roller. 11. The heat fixing roller according to claim 10, wherein the ribs at both ends extend toward the center of the cylindrical portion as compared with the rib at the center. 12. The heat fixing roller according to claim 9, wherein the central portion and the both end portions divided into three before the plasma welding are joined by press-fitting. 13. The joint between the ribs at both ends of the cylindrical portion divided into three and the ribs at the center is formed in a gentle straight line or curved shape from the center to the both ends. 10. The heat fixing roller according to claim 9, wherein the height of the rib extends toward the support portion. 14. The rib on one drive side of the both end portions has a larger volume of the rib portion than the rib on the opposite side by increasing the number of velves or increasing the height of the rib. The heat-fixing roller according to claim 9. 15. The heat fixing roller according to claim 9, wherein ribs are provided only at both ends.