JP4114864B2 - Powder heating / cooling device, fixing device, and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, or a complex machine thereof. The present invention also relates to a fixing device that fixes an unfixed transfer image formed on a recording medium such as paper or an OHP film on the recording medium in such an image forming apparatus. In addition, the toner image is fixed by heating and cooling a powder made of a resin or a mixture of a resin and a wax, such as a toner / hot melt, and used for such a fixing device, or a granular hot melt product is produced. The present invention relates to a powder heating / cooling device for producing a sheet-like hot melt product or for producing a bonded hot melt product.
[0002]
[Prior art]
Conventionally, when making a hot melt product, a hot melt made of a resin or a mixture of resin and wax is heated and melted while being heated in a dissolution tank, and then cooled, and then cooled to a metal product when it is a granular product. In the case of a sheet-like product, it was dropped by a rolling mill.
[0003]
When making a laminated product, for example, a hot melt is coated on a base sheet such as paper or film in advance, and the hot melt melted thereon is applied by curtain coating using a T-die. A hot melt was dissolved in an organic solvent, coated with a roller or a rod, and then dried, and then heat and pressure were applied to each other with a heat roller.
[0004]
However, in these conventional manufacturing methods, there is a problem in that it adheres to a melting tank or an extruder and requires a minimum amount of hot melt to drive them, and wastes hot melt and results in poor yield. . In addition, a large space is required to install a melting tank, an extruder, etc., and a large amount of heat energy is required to maintain these devices. There were problems such as large.
[0005]
Even when making bonded products, the base sheet is pre-coated with hot melt, so a device for creating a thermal coating or solvent coating solution is required, and the equipment investment and process costs of the coating machine are large. It took.
[0006]
In addition, when the cooling is insufficient, there is a problem that hot melt adheres to a rotary conveyance member such as a roller or a belt, or, for example, in the case of a bonded product, the bonded surface is displaced. On the other hand, if the cooling is excessive, there is a problem that the hot melt contracts and curls or twists.
[0007]
[Patent Document 1]
On the other hand, in a fixing device provided in a conventional image forming apparatus, for example, as shown in FIG. 6, a pair of rotary conveying members are brought into contact with each other to form a nip n; The heating means b for heating the powder t conveyed through the nip n of the conveying means a and the cooling means c for cooling the powder t heated by the heating means b (see Patent Document 1). ).
[0008]
In this fixing device, one rotating and conveying member is constituted by a belt 3 wound around a heating roller 1 and a guide roller 2, and the other rotating and conveying member is constituted by a heating roller 4. In each of the heating rollers 1 and 4, a heater is provided as the heating means b. The powder t is toner of a toner image formed by transferring on the recording medium 5. The cooling means c is configured such that the belt 8 is wound around the two guide rollers 6 and 7, a plurality of openings are provided in the belt 8, and wind is applied through the openings to cool the powder t.
[0009]
[Problems to be solved by the invention]
However, in such a conventional fixing device, since the cooling temperature of the cooling means c is fixed, only uniform cooling can be performed. For example, depending on whether the recording medium 5 is a business document or a photograph. Optimal fixing could not be performed depending on the type of recording medium, such as changing the cooling conditions.
[0010]
And if the cooling temperature is high, the photo will be insufficiently cooled and low gloss, and if the cooling temperature is low, the business document will be too cool and high gloss, and the reflection will be large and difficult to read. There was a problem.
[0011]
Therefore, the first object of the present invention is to improve the yield, reduce the capital investment on a small scale, lower the maintenance cost, reduce the danger, and according to the type of powder, recording medium, etc. An object of the present invention is to provide a powder heating / cooling device that optimally heats and cools powder.
[0012]
A second object of the present invention is to provide a powder heating / cooling device that optimally heats and cools powder according to the type of powder, recording medium, etc., with a particularly simple configuration.
[0013]
A third object of the present invention is to provide a powder heating / cooling device that enables stable heating and cooling of powder.
[0014]
A fourth object of the present invention is to provide a powder heating / cooling device having good heat conduction and good thermal efficiency.
[0015]
A fifth object of the present invention is to provide a powder heating / cooling apparatus having a long life.
[0016]
A sixth object of the present invention is to provide a fixing device including a powder heating / cooling device that achieves the above-mentioned objects.
[0017]
A seventh object of the present invention is to provide an image forming apparatus provided with a fixing device that achieves the sixth object.
[0019]
[Means for Solving the Problems]
According to the first aspect of the present invention, in order to achieve the first object described above, a pair of rotating conveying members are brought into contact with each other to form a nip, and the conveying means is supplied onto the rotating conveying member. Alternatively, in a powder heating and cooling apparatus, comprising: a heating unit that heats the powder that is supplied onto the sheet conveyed by the conveying unit and conveyed through the nip; and a cooling unit that cools the powder heated by the heating unit. ,
The cooling means is provided with a plurality of surfaces with different lengths in the rotation direction on the outer periphery, and the cooling degree of the powder can be changed by changing the surface that is rotatably supported and faces the rotary conveying member. It is comprised with the cooling body to be characterized by the above-mentioned.
[0023]
According to a second aspect of the invention, the third object described above is also to achieve, in the powder heating and cooling device according to claim 1, at least one of the pair of rotating conveying members is an endless belt, the endless belt It is characterized by a constant tension.
[0025]
According to a third aspect of the invention, the fourth object described above is also to achieve, in the powder heating and cooling apparatus according to claim 2, the metallic endless belt at least one of the pair of rotating conveying members, It is characterized by that.
[0026]
According to a fourth aspect of the present invention, in order to achieve the fifth object described above, in the powder heating / cooling device according to the second aspect , at least one of the pair of rotary conveying members is an endless belt made of a heat resistant resin. It is characterized by that.
[0027]
According to a fifth aspect of the present invention, in order to achieve the sixth object described above, the powder heating / cooling device according to any one of the first to fourth aspects is used. The recording medium on which the toner image is formed is conveyed through a nip by a conveying means, heated by a heating means, the powder after the heating is cooled by a cooling means, and an unfixed toner image is fixed on the recording medium. Device.
[0028]
According to a sixth aspect of the present invention, there is provided an image forming apparatus comprising the fixing device according to the fifth aspect in order to achieve the seventh object described above.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a schematic configuration of a powder heating and cooling apparatus according to the present invention for producing a granular hot melt product.
[0030]
Reference numeral 10 in the drawing denotes a heating endless belt that constitutes one of a pair of rotary conveying members. The heating endless belt 10 is wound around a driving roller 11 and driven rollers 12 and 13 and presses a tension roller 14 from the outside. Inside the heating endless belt 10, along the horizontally stretched portion between the driving roller 11 and the driven roller 13, a heating body 16 that is the heating means 15 and two coolings that are the cooling means 17. The bodies 18 and 19 are arranged.
[0031]
One cooling body 18 is movable and can be moved up and down in the drawing by using a driving means such as a solenoid / micro motor (not shown), a cam, etc., and can be moved closer to or far away from the heating endless belt 10. Like that. The other cooling body 19 is fixed to a bracket or the like (not shown) using screws or the like so that the movement cannot be adjusted.
[0032]
Reference numeral 20 in the drawing denotes a pressure endless belt constituting the other of the pair of rotary conveying members. The pressure endless belt 20 is wound around the driving roller 21 and the driven rollers 22 and 23. One driven roller 22 is urged by a spring 24 and pressed against the heating body 16 via the endless belts 10 and 20. Thus, the heating endless belt 10 and the pressure endless belt 20 constituting the pair of rotary conveying members are provided with conveying means 25 that forms a nip N by contacting each other. A supply nozzle 27 for supplying hot melt resin powder 26 is provided on the heating endless belt 10 and beside the pressure endless belt 20.
[0033]
Then, the driving rollers 11 and 21 are rotated together by a driving means (not shown) to rotate the driven rollers 12 and 13 and the driven rollers 22 and 23, respectively. The heating endless belt 10 is rotated counterclockwise, and the pressure endless belt 20 is rotated. Each continuously running clockwise. At the same time, the hot melt resin powder 26 is intermittently supplied from the supply nozzle 27 onto the heating endless belt 10 by a predetermined amount, and a small crest of the resin powder 26 is intermittently formed.
[0034]
Thereby, the small crest of the resin powder 26 is conveyed through the nip N by the conveying means 25 as the both endless belts 10 and 20 travel, and is heated and melted by the heating means 15 while being pressed between the both endless belts 10 and 20. The resin powder 26 heated by the heating means 15 is cooled by the cooling means 17.
[0035]
At this time, the degree of cooling can be changed by moving the movable cooling body 18 closer to or farther away from the heating endless belt 10, and the moving distance is adjusted according to the type of the powder 26 with a particularly simple configuration. Thus, the powder 26 can be optimally heated and cooled. If the fixed cooling body 19 alone is insufficiently cooled, the movable cooling body 18 is also pressed against the heating endless belt 10 and cooled by both cooling bodies 18 and 19 to form a granular hot melt product 30. Then, the paper is discharged from between both endless belts 10, 20.
[0036]
FIG. 2 shows a case where a sheet-like hot melt product is produced using the powder heating / cooling apparatus shown in FIG.
[0037]
When producing a sheet-like hot melt product, a predetermined amount of hot melt resin powder 26 is continuously supplied from the supply nozzle 27 as both endless belts 10 and 20 run, and the resin powder 26 is applied onto the heated endless belt 10. Form a layer.
[0038]
Then, the layer of the resin powder 26 is conveyed through the nip N by the conveying means 25 as the both endless belts 10 and 20 travel, and is heated and melted by the heating means 15 while being pressed between the both endless belts 10 and 20, The powder 26 heated by the heating means 15 is cooled by the cooling means 17.
[0039]
At this time, similarly, the degree of cooling can be changed by moving the movable cooling body 18 closer to or away from the heating endless belt 10, and the moving degree can be changed depending on the type of the powder 26 with a particularly simple configuration. By adjusting, the powder 26 can be optimally heated and cooled. If the fixed cooling body 19 alone is insufficiently cooled, the movable cooling body 18 is also added and the both cooling bodies 18 and 19 are used to form a sheet-like hot melt product 31 to form both endless belts 10. Discharge from 20 to 20 minutes.
[0040]
FIG. 3 shows a case where a bonded hot melt product is produced using the powder heating / cooling apparatus shown in FIG. In this case, the conveyance roller 33 is provided at the nip upstream position of the heating endless belt 10, and the supply roller 34 is provided at the nip upstream position of the pressure endless belt 20.
[0041]
Then, the sheet 35 is supplied onto the heating endless belt 10 by the conveying roller 33, and the hot melt resin powder 26 is continuously supplied from the supply nozzle 27 to the sheet 35 by a predetermined amount to form a layer of the resin powder 26. Thereafter, another sheet 36 is supplied onto the hot melt resin powder 26 by the supply roller 34.
[0042]
Then, the two endless belts 10 and 20 are transported through the nip N by the transport means 25 and heated and melted by the heating means 15 while being pressed between the two endless belts 10 and 20, and the resin powder 26 is used for the sheet 35 and the sheet. 36 are pasted together, and the powder 26 after being heated by the heating means 15 is cooled by the cooling means 17.
[0043]
At this time, similarly, the degree of cooling can be changed by moving the movable cooling body 18 closer to or away from the heating endless belt 10 which is a rotary conveying member. Accordingly, the powder 26 can be optimally heated and cooled by adjusting the near-retreat movement. If the fixed cooling body 19 alone is insufficiently cooled, the movable cooling body 18 is also added and the both cooling bodies 18 and 19 are cooled to form a bonded hot melt product 37 to form both endless belts 10 and 20. Drain from between.
[0044]
In the above-described example, the degree of cooling can be changed by moving the movable cooling body 18 closer or far away. However, the cooling body is provided with a long surface and a short surface, and the cooling body can be rotated. Then, the degree of cooling may be changed by selectively changing the surface facing the heating endless belt 10 by rotating the cooling body.
[0045]
For example, as shown in FIG. 4A, the cooling means 17 is constituted by a rectangular parallelepiped cooling body 40, and the cooling body 40 is provided with a long surface 40a having a length L1 and a short surface 40b having a length L2. The cooling body 40 is supported so as to be rotatable about a shaft 41. Then, by rotating the cooling body 40, the surface facing the heating endless belt 10 is changed so that the cooling degree can be changed. That is, when the cooling is insufficient, the long end surface 40a is pressed against the heating endless belt 10, and when the cooling is excessive, the short end surface 40b is pressed. Reference numeral 42 in the drawing denotes a spring that presses the cooling body 40 against the heating endless belt 10.
[0046]
In the example shown in FIG. 4A, the cooling body 40 has a rectangular parallelepiped shape and two surfaces, a long surface and a short surface, are prepared. However, as shown in FIG. A plurality of surfaces 43 a having different lengths are provided, and the cooling body 43 is supported so as to be rotatable about a shaft 44.
[0047]
Then, the cooling body 43 is rotated to select a surface having an appropriate length, and the surface of the polyhedron facing the heating endless belt 10 can be changed so as to be optimally cooled according to the type of the powder 26. You may make it press on the heating endless belt 10. FIG. That is, the longer end surface 43a is pressed against the heating endless belt 10 when the cooling is insufficient, and the shorter end surface 43a is pressed when the cooling is excessive. Reference numeral 45 in the drawing is a spring that presses the cooling body 43 against the heating endless belt 10.
[0048]
FIG. 5 shows a case where the powder heating / cooling device according to the present invention is applied to a fixing device of an image forming apparatus.
[0049]
Similarly, the heating endless belt 10 is wound around the driving roller 11 and the driven roller 12 and presses the tension roller 14 from the outside. Inside the heating endless belt 10, a heating body 16 that is a heating means 15 and a cooling means 17 are 2 so that the heating endless belt 10 is horizontally stretched between the driving roller 11 and the driven roller 12. Two cooling bodies 18 and 19 are arranged.
[0050]
One cooling body 18 is movable and can be moved up and down in the drawing by using a driving means such as a solenoid / micro motor (not shown), a cam, etc., and can be moved closer to or far away from the heating endless belt 10. Like that. The other cooling body 19 is fixed to a bracket or the like (not shown) using screws or the like so that the movement cannot be adjusted.
[0051]
The pressure endless belt 20 is wound around the driving roller 21 and the driven rollers 22 and 23. One driven roller 22 is urged by a spring 24 and pressed against the heating body 16 via the endless belts 10 and 20. Thus, the heating endless belt 10 and the pressure endless belt 20 constituting the pair of rotary conveying members are provided with conveying means 25 that forms a nip N by contacting each other.
[0052]
Then, the driving rollers 11 and 21 are rotated together by a driving means (not shown) to rotate the driven roller 12 and the driven rollers 22 and 23 respectively, and the heating endless belt 10 is rotated clockwise and the pressure endless belt 20 is counterclockwise. Each of the recording media 51 travels continuously around the nip N, and a recording medium 51 on which an unfixed toner image is formed by transferring toner powder 50 is inserted into the nip N.
[0053]
As a result, the recording medium 51 is conveyed through the nip N by the conveying means 25 as the both endless belts 10 and 20 travel, and is heated and melted by the heating means 15 while being pressed between the both endless belts 10 and 20, and the heating is performed. The toner 50 heated by the means 15 is cooled by the cooling means 17 and the unfixed toner image is fixed on the recording medium 51.
[0054]
At this time, the degree of cooling can be changed by moving the movable cooling body 18 closer to or away from the heating endless belt 10 which is a rotary conveying member, and it has a particularly simple configuration, depending on the type of the recording medium 51. The toner 50 can be optimally heated and cooled by adjusting the near and backward movement. That is, when high gloss is desired, such as in the case of a photograph, the cooling body 19 alone is not enough for cooling, and the movable cooling body 18 is also pressed against the heating endless belt 10, and both cooling bodies 18, 19 are used. Fix and discharge by cooling. When low gloss is desired, such as for business documents, the movable cooling body 18 is separated and cooled only by the fixed cooling body 19 to be fixed and discharged.
[0055]
In the example described above, the cooling means 17 is composed of the cooling bodies 18, 19, 40, and 43, respectively. The cooling body is configured such that a cooling medium such as water flows through a cooling pipe fixed by brazing or press-fitting, for example. It is good also as a structure which can change a cooling degree by changing the flow rate of the cooling medium which flows through the inside of the heat pipe by making a cooling body into a heat pipe.
[0056]
In addition, the cooling means 17 changes the cooling time by bringing the cooling body into contact with or away from the rotating conveyance member as described above, or changing the length of the surface that rotates and faces the rotating conveyance member, In addition, it is not limited to the case where the cooling degree can be changed by adjusting the flow rate of the cooling medium flowing in the heat pipe, for example, the air blowing device, and the cooling degree can be changed by changing the air blowing amount of the air blowing device. Also good.
[0057]
In the above-described example, the cooling body 18, 19, 40, 43 is pressed against the heating endless belt 10 that is a rotary conveying member, the pressing is released, or the contact surface is changed. For example, the tension of the heating endless belt 10 may be kept constant so as not to fluctuate. It is preferable that the tension of the pressure endless roller 20 is not limited to the heating endless belt 10 but also constant.
[0058]
The endless belts 10 and 20 may be made of metal or heat-resistant resin, and if made of metal such as nickel or stainless steel, heat conductivity is increased to improve thermal efficiency, and heat-resistant resin such as polyimide resin or polybenzimidazole resin. If it is made, the life can be extended.
[0059]
【The invention's effect】
As described above, according to the first aspect of the present invention, the pair of rotary transport members are brought into contact with each other to form a nip, and the transport means is supplied to or transported by the transport means. Since the heating means for heating the powder supplied onto the sheet and conveyed through the nip and the cooling means for cooling the powder heated by the heating means are provided, while conveying the powder through the nip by the conveying means, After heating by the heating means, cooling is performed by the cooling means, and the used powder can be used for a product close to 100%, and the yield can be improved.
[0060]
Since a large apparatus such as a dissolution tank or an extruder is not required, a small installation space is required, and since it is not necessary to heat and melt the hot melt in advance, a small-scale equipment investment can be reduced. Moreover, since a large amount of energy is not required to maintain the equipment and it is not necessary to keep the heat, the heat energy can be reduced and the maintenance cost can be reduced. In addition, since it is not necessary to handle a large amount of hot-melted hot melt, safety is improved and danger is reduced.
[0061]
According to the first aspect of the present invention, the degree of cooling by the cooling means can be changed, so that the powder is optimally heated and cooled according to the type of the powder, the recording medium, etc. It is possible to prevent the sticking to the rotary conveying member, or the possibility that the bonded surface is displaced in the case of a bonded product, for example. On the other hand, it is possible to prevent the hot melt from shrinking due to overcooling and causing the product to curl or twist. Further, the glossiness of the image can be changed by adjusting the finished state, for example, depending on whether it is a business document or a photograph.
[0066]
According to the invention of claim 2 , in addition to the effect of the invention of claim 1, at least one of the pair of rotary conveying members is an endless belt, and the tension of the endless belt is made constant. Heating and cooling can be performed stably without variation.
[0068]
According to the invention of claim 3 , in addition to the effects of the invention described above, since at least one of the pair of rotary conveying members is a metal endless belt, the heat conduction is good and the heat efficiency is improved to heat and cool the powder. Can be made possible.
[0069]
According to the invention of claim 4 , in addition to the effects of the invention described above, at least one of the pair of rotary conveying members is an endless belt made of a heat-resistant resin, so that the durability can be improved and the powder can be heated and cooled. It can be.
[0070]
According to a fifth aspect of the present invention, a recording medium on which an unfixed toner image is formed with toner which is powder using a powder heating and cooling device according to any one of the first to fourth aspects is conveyed by a conveying means. A fixing device provided with a powder heating / cooling device having the above-mentioned effects, since the powder after heating is cooled by a cooling means and the unfixed toner image is fixed on a recording medium. Can be provided.
[0071]
Then, the gloss of the toner image can be adjusted by the fixing device. For example, in the case of a photographic image, the quality is improved as a high gloss, and in the case of a business document, the reflection is reduced as a low gloss, so that it can be easily read.
[0072]
According to the sixth aspect of the present invention, it is possible to provide an image forming apparatus provided with a fixing device having such an effect.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a powder heating and cooling apparatus according to the present invention for forming a granular hot melt product.
FIG. 2 shows a case where a sheet-like hot melt product is formed using the powder heating / cooling apparatus shown in FIG.
FIG. 3 shows a case where a bonded hot melt product is formed using the powder heating / cooling apparatus shown in FIG. 1;
FIGS. 4A and 4B are diagrams illustrating use of a cooling unit, in which FIG. 4A shows a case where a rectangular parallelepiped cooling body is used, and FIG. 4B shows a case where a polyhedral cooling body is used.
FIG. 5 is a schematic configuration diagram of a powder heating / cooling device according to the present invention applied to a fixing device of an image forming apparatus.
FIG. 6 is a schematic configuration diagram of a conventional powder heating / cooling apparatus.
[Explanation of symbols]
10 Heating endless belt (rotary conveying member)
DESCRIPTION OF SYMBOLS 15 Heating means 16 Heating body 17 Cooling means 18 Movable cooling body 19 Fixed cooling body 20 Pressure endless belt (rotating conveyance member)
25 Conveying means 26 Powder 40 Cooling body (cooling means)
43 Cooling body (cooling means)
50 Toner (powder)
51 Recording medium N Nip

Claims (6)

A conveying means for forming a nip by bringing a pair of rotating conveying members into contact with each other, and a powder supplied to the rotating conveying member of the conveying means or supplied onto the sheet conveyed by the conveying means and conveyed through the nip In a powder heating and cooling device comprising a heating means for heating the powder and a cooling means for cooling the powder after heating by the heating means,
The cooling means is provided with a plurality of surfaces with different lengths in the rotation direction on the outer periphery, and the cooling degree of the powder can be changed by changing the surface that is rotatably supported and faces the rotary conveying member. A powder heating / cooling device, comprising: a cooling body. The powder heating / cooling device according to claim 1, wherein at least one of the pair of rotary conveying members is an endless belt, and the tension of the endless belt is constant. The powder heating / cooling device according to claim 2 , wherein at least one of the pair of rotary conveying members is a metal endless belt. The powder heating / cooling device according to claim 2 , wherein at least one of the pair of rotary conveying members is an endless belt made of a heat-resistant resin. A recording medium on which an unfixed toner image is formed with toner that is powder is conveyed through the nip by the conveying means using the powder heating and cooling device according to any one of claims 1 to 4 , and the heating means A fixing device, characterized in that the heated powder is cooled by the cooling means to fix an unfixed toner image on a recording medium. An image forming apparatus comprising the fixing device according to claim 5 .

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