JPH0114037Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a heat fixing device in which copy paper having a toner image passes between a pair of rollers and the toner image is fixed by heating. The present invention relates to a heat fixing device in which oil is attached to the peripheral surface of a roller in order to remove oil and prevent copy paper from being wrapped around the roller.

Conventionally, in such a heat fixing device,
After fixing, scrape off the oil on the circumferential surface of the roller with a blade,
An oil tray is arranged below the roller to receive oil dripping from the roller, and the oil dripping from the roller is stored in the oil pan. When disposing of the oil stored in the oil pan, the oil pan is removed from the body of the electrostatic copying machine and the oil is discharged from the oil pan. In such prior art, when the oil pan is removed from the fuselage, there is a risk that the oil in the oil pan may be spilled into or around the fuselage. Furthermore, since the oil has a high viscosity, it is impossible to completely drain the oil from the oil pan. Moreover, while the copying machine is being transported, there is a risk that the oil in the oil pan may spill inside the machine.

The prior art to solve this problem is
30939, and it is shown in FIG.
Fixing is performed by passing the copy paper on which the toner image has been formed between rollers 41 and 43. An oil application roller 45 is in pressure contact above the roller 41, and an oil supply roller 47 is in pressure contact above the oil application roller 45. A felt 52 that contacts the roller 43 is arranged below the roller 43, and the felt 52 is housed in an oil pan 51.

In the prior art shown in FIG. 7, after the copy paper passes between the rollers 41 and 43 and is fixed, the stained oil is absorbed by the felt 52, and the stained oil is transferred to the roller 43. It remains attached to the copy paper again, and as a result, the rollers 41 and 43
Copy paper passing through the gap will be soiled. Another problem with this prior art is that the felt 52 is in contact with the roller 43. Therefore, in order to prevent the felt 52 from coming off the oil pan 51 as the roller 43 rotates, the felt 52 must be removed. It is necessary to fix it to the oil pan 51. This makes it difficult to remove and replace the felt 52 from the oil pan 51. felt 5
2, it is necessary to separate the roller 43 and the felt 52, and a configuration for that purpose is required.Alternatively, if the roller 43 and the felt 52 are kept in pressure contact and the felt 52 is pulled, the felt 5
There is a risk that the oil absorbed by the oil may spill outward from the oil pan.

The purpose of the present invention is to prevent copying paper passing between rollers from being soiled by oil in the oil pan in a heat fixing device, and to utilize the oil effectively and remove undesirable oil in the oil pan. To provide a heat fixing device which can be easily disposed of without spilling.

The present invention provides a heat fixing device that has a heat source 8 on at least one side and a pair of rollers 4 and 5 disposed above and below, and heats and fixes copy paper 1 by passing it between these rollers 4 and 5. , the upper and lower rollers 4 and 5 are at their contact position 15
The upper and lower casings 9 and 10 are open facing the
The upper roller 4 is provided at both ends of the first central thermal fixing section 4a and the first central thermal fixing section 4a, and is surrounded by a first central thermal fixing section 4a.
Oil guide portions 27, 2 having a smaller diameter than the central heat fixing portion 4a
8, and the first central heat fixing section 4a of the upper roller 4 has a
An oil coating piece 22 is applied over the entire length of the central heat fixing section 4a.
An oil application means 20 is provided for applying oil by contacting the first central heat fixing section 4a of the upper roller 4, and a blade 24 is provided for scraping off oil applied to the circumferential surface of the first central heat fixing section 4a of the upper roller 4. Means 20 is
along the rotational direction in a range that is forward of the rotational direction of the upper roller 4 than a vertical line passing through the axis of the upper roller 4 and rearward of the contact position 15 of the upper and lower rollers 4 and 5 in the rotational direction. The ends 29 and 30 of the blade 24 extend halfway in the longitudinal direction of the oil guide parts 27 and 28, and the lower roller 5 connects the second central heat fixing part 5a and the second central heat fixing part 5a. Lower roller shafts 47 and 48 are provided at both ends in the longitudinal direction of the second central heat fixing section 5a and have a smaller diameter than the second central heat fixing section 5a. , is arranged in the casing 10 directly below the oil guide parts 27 and 28 via a support member, and the second central heat fixing part 5a of the lower roller 5 is formed shorter than the first central heat fixing part 4a of the upper roller 4. The second central heat fixing section 5a of the lower roller 5 is connected to the first central heat fixing section 4 of the upper roller 4 over its entire length.
a, is removably disposed inside the lower casing 10 and horizontally directly below the lower roller 5, is spaced downward from the lower roller 5, and extends in the axial direction over the entire length of the upper and lower rollers 4 and 5. an oil pan 25 that extends and spreads on both sides of the axes of the upper and lower rollers 4 and 5; and an oil absorbent that is disposed within the oil pan 25 at a distance from the lower roller 5 and below, and that is removable from the oil pan 25. The heat fixing device is characterized in that the oil receiving tray 25 is positioned within the lower casing 10 at a position where it can receive oil dripping from the rollers 4 and 5.

FIG. 1 is a sectional view of an embodiment of the present invention.
In an electrostatic copying machine, copy paper 1 on which a toner image has been formed corresponding to a document is guided in the direction of arrow 2 and is heat-fixed by a heat-fixing device 3 according to the present invention. A toner image is formed on the upper surface of the copy paper 1.

FIG. 2 is a partially cutaway perspective view of the heat fixing device shown in FIG. 1, and FIGS. 3 and 4 are simplified sectional views taken along the cutting plane line - and - of FIG. 1. In this heat fixing device 3, a heat roller 4 and a pressure roller 5 are arranged above and below, respectively. The heat roller 4 is rotationally driven by a sprocket wheel 36 in the direction of arrow 6. Further, the central heat fixing portion 5a of the pressure roller 5 contacts the central heat fixing portion 4a of the heat roller 4 at a contact position 15, and is rotated in the direction of arrow 7. A heat source 8 fixed to the machine body is inserted into the heat roller 4 over the entire length of the roller 4 .

The heat roller 4 and the pressure roller 5 are partially surrounded by upper and lower casings 9 and 10, respectively. The casings 9 and 10 are open as indicated by reference numerals 11 and 12, facing the contact position 15 of the central heat fixing portions 4a and 5a of the heat roller 4 and the pressure roller 5, respectively. Openings 11, 1 in casings 9, 10
The portions 13, 14 in the vicinity of 2 perform the function of guiding the copy paper 1. The central heat fixing portion 4a of the heat roller 4 is formed by coating the outer periphery of a metal cylindrical body 16 with a coating layer 17 made of Teflon (trade name). The central heat fixing portion 5a of the pressure roller 5 is formed by covering the outer periphery of a metal cylindrical body 18 with heat-resistant rubber 19.

In the upper casing 9, a coating means 20 is provided for applying silicone oil to the circumferential surface of the central heat fixing portion 4a of the heat roller 4. The application means 20 for this application is located forward of the rotation direction 6 of the heat roller 4 with respect to a vertical line 21 passing through the axis of the heat roller 4 (see FIG. 1), and behind the contact position 15 in the rotation direction 6. . The application means 20 is applied to the casing 9
A support piece 35 fixed to the heat roller 4 and extending horizontally over the entire length of the heat roller 4, and a material such as felt that is supported by the support piece 35 and contacts the circumferential surface over the entire length of the central heat fixing portion 4a of the heat roller 4. and a storage tank 23 in which the end of the application piece 22 is immersed and stores silicone oil. The application piece 22 contacts the heat roller 4 in parallel with its axis. The viscosity of silicone oil is, for example, 500~ at room temperature.
It is 5000 centistokes.

The blade 2 is used to scrape off the silicone oil applied to the circumferential surface of the central heat fixing part 4a of the heat roller 4.
4 is provided in the range from the vertical line 21 to the application means 20 in front of the rotational direction 6 of the heat roller 4, and the silicone oil that has passed through the mutual contact position 15 between the central heat fixing parts 4a and 5a of the rollers 4 and 5. scrape off. The blade 24 is made of a material such as fluorine rubber. The heat roller 4 and the pressure roller 5 have horizontal axes, and the tip 24a of the blade 24 extends parallel to these axes and comes into contact with the circumferential surface of the central heat fixing portion 4a of the heat roller 4.

Silicone oil is applied to heat roller 4 and pressure roller 5.
By applying it to the circumferential surface of each central heat fixing section 4a, 5a, the copy paper 1 is prevented from being wrapped around the heat roller 4 and pressure roller 5, and is easily peeled off. Further, the toner adhering to the circumferential surface of the central thermal fixing section 4a of the thermal roller 4 from the top of the copy paper 1 is scraped off together with silicone oil by the blade 24.
The peripheral surface of a is cleaned, and copy quality is improved.

The heat roller 4 is provided at both ends of the central heat fixing section 4a.
Oil guide portions 27 and 28 having a smaller diameter than the central heat fixing portion 4a of the heat roller 4 are provided. Both end portions 29 and 30 of the blade 24 extend halfway in the longitudinal direction of the oil guide portions 27 and 28. The central heat fixing part 5a of the pressure roller 5 is formed slightly shorter than the central heat fixing part 4a of the heat roller 4, and the central heat fixing part 5a of the pressure roller 5 is formed slightly shorter than the central heat fixing part 4a of the heat roller 4.
The silicone oil that falls from the center heat fixing portion 5a of the pressure roller 5 does not adhere to the center heat fixing portion 5a of the pressure roller 5. As mentioned above, both ends 29 and 30 of the blade 24 extend halfway in the longitudinal direction of the oil guide parts 27 and 28, so the oil scraped off by the blade 24 is transferred to the upper heat roller 4. The bearing 4 flows from the central heat fixing part 4a to both ends in the axial direction, passes through the oil guide parts 27 and 28, and supports the shafts 47 and 48 of the pressure roller 5.
9,50, and the oil pan 25 which will be described next.
fall on top. The bearings 49 and 50 are connected to the casing 1
0 via support members 49a and 50a,
It is arranged directly below the oil guide parts 27 and 28.

The lower casing 10 has its casing 1
An oil pan 25 is arranged horizontally so as to be removable from the oil pan 25. This oil pan 25 is connected to the heat roller 4 and the oil guide section 2.
7, 28 and the pressure roller 5, it extends in the axial direction over their entire length, and spreads on both sides (left and right in FIG. 1) of the axes of the heat roller 4 and the pressure roller 5. Inside the oil pan 25, an oil-absorbing sheet 2 is placed over almost the entire bottom of the oil pan 25.
6 is provided. This sheet 26 may be made of felt, for example, or may be porous or fibrous with heat resistance, and therefore has the property of easily absorbing oil dripping from the heat roller 4 and the pressure roller 5. This sheet 26 is arranged below the pressure roller 5 at a distance, and therefore does not come into contact with the pressure roller 5. Therefore, the copy paper will not be soiled. Further, since the sheet 26 is not in contact with the roller 5, the sheet 26 will not come off the oil pan 25 due to the rotation of the pressure roller 5, and there is no need to fix the sheet 26 to the oil pan 25. This makes it easy to replace the sheet 26.

The silicone oil scraped off by the blade 24 flows from the central heat fixing portion 4a of the heat roller 4 to both ends in the axial direction, and flows from the oil guide portions 27 and 28 through the bearings 49 and 50 onto the oil pan 25. to fall. This fallen oil is absorbed by the sheet 26. To drain oil from the oil pan 25, remove the oil pan 25 from the machine body, discard the sheet 26, place a new sheet on the oil pan 25, and install the oil pan 25 as shown in the figure. .

As is clear from Figures 1 to 4, the oil pan 2
5 is positioned in a substantially snug manner within the lower casing 10. Therefore, the oil pan 25 is in a position to reliably receive the oil dripping from the rollers 4 and 5, and does not shift from that position within the casing 10.

Note that other oils may be used instead of silicone oil.

As described above, according to the present invention, the following effects (1) to (10) are achieved.
is achieved.

(1) An oil-absorbing sheet 26 is removably provided in the oil pan 25, and when the oil is to be disposed of, it is only necessary to replace this sheet 26 with a new one. Therefore, the operation for removing oil from the oil pan 25 is easy, and moreover, it is possible to almost completely drain high viscosity oil from the oil pan 25. Further, when the oil pan 25 is taken out from the machine body or when the machine body vibrates during transportation, the oil in the oil pan 25 does not spill inside or outside the machine body and become dirty.

(2) Particularly in the present invention, the oil-absorbing sheet 26 provided in the oil pan 25 is placed below and apart from the lower roller 5 of the pair of rollers 4 and 5, and therefore absorbs oil. The elastic sheet 26 never comes into contact with the lower roller 5. Therefore, the soiled oil absorbed by the oil-absorbing sheet 26 does not adhere to the rollers, thereby preventing the copy paper 1 passing between the rollers 4 and 5 from becoming soiled.

(3) Furthermore, since the oil-absorbing sheet 26 is not in contact with the lower roller 5, there is no risk that the oil-absorbing sheet 26 will come off from the oil pan 25 due to the rotation of the lower roller 5. There is no need to fix the oil absorbent sheet 26 to the oil pan 25, and the oil absorbent sheet 26 can be easily replaced.

(4) The oil pan 25 is removable from the lower casing 10, so when replacing the oil absorbent sheet 26, first remove the oil pan 25 from the lower casing 10, and then replace the oil pan 25. By removing the inner oil-absorbing sheet 26, the oil contained in the oil-absorbing sheet 26 is prevented from dripping into and around the lower casing 10 and staining it.

(5) The oil pan 25 is positioned within the lower casing 10 at a position where it can receive the oil dripping from the rollers 4 and 5, so it can reliably receive the oil dripping from the rollers 4 and 5. This also prevents the inside of the lower casing 10 from becoming soiled. Furthermore, by storing the oil pan 25 in the lower casing 10, it is positioned as described above, so that the operation of storing the oil pan 25 in the lower casing 10 can be easily performed. I can do it.

(6) Each roller 4, 5 is connected to the upper and lower casings 9, 1
0, even if the oil dripping from the rollers 4, 5 is scattered, it will be received within the casings 9, 10. Therefore, oil does not scatter outside the casings 9, 10, and it is possible to suppress contamination to the smallest possible range.

(7) Furthermore, since the central heat fixing part 5a of the lower roller 5 is formed shorter than the central heat fixing part 4a of the upper roller 4, the oil scraped off by the blade 24 may cause the central heat fixing part 5a of the lower roller 5 to Heat fixing section 5a
There is no risk of contaminating the surrounding surface. Therefore, the peripheral surfaces of the central heat fixing parts 4a, 5a of the rollers 4, 5 are always kept clean, new oil can be reapplied, and copy paper is reliably prevented from adhering to the rollers 4, 5. At the same time, copy quality can be improved without staining the copy paper.

(8) Also, the blade 24 and the oil application means 2
0 refers to the vertical line 2 passing through the axis of the upper roller 4.
1 in the rotational direction of the upper roller 4 and behind the contact position 15 of the upper and lower rollers 4 and 5 in the rotational direction, and arranged in this order along the rotational direction. Therefore, the oil scraped off by the blade 24 (that is, the oil contaminated by toner) is prevented from flowing down the circumferential surface of the central heat fixing section 4a of the upper roller 4, and the oil scraped off by the blade 24 is prevented from flowing down. It is possible to prevent the peripheral surface of the central heat fixing section 4a from being soiled.

That is, if the above configuration is not adopted and the blade 24 is placed to the left of the vertical line 21 in FIG. but,
The oil that has flowed down the circumferential surface of the central heat fixing part 4a of the upper roller 4 and has been scraped off is removed by the blade 24 to the oil guide part 27,
28 becomes impossible. With the above-described configuration according to the present invention, such problems can be solved.

(9) Both end portions 29 and 30 of the blade 24 extend halfway in the longitudinal direction of the oil guide portions 27 and 28, so that the oil applied on the circumferential surface of the central heat fixing portion 4a of the upper roller 4 is transferred to the blade 24. This makes it possible to reliably scrape off the oil and guide it to the oil guide parts 27 and 28. That is, the reason why the ends 29 and 30 of the blade 24 extend to the middle of the oil guide parts 27 and 28 is the central heat fixing part 4a of the heat roller 4.
This is to remove silicone oil from the peripheral surface and guide the removed silicone oil to the oil guide portions 27 and 28.

(10) In addition, in the present invention, the bearing of the lower roller is placed directly below the oil guide, thereby cooling the bearing of the lower roller, thereby improving the durability of the bearing. The lubricating action of the bearing can be promoted, and oil can be used effectively.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is a partially cutaway perspective view of the heating fixing device shown in FIG. 1, and FIGS. 3 and 4 are cross-sectional views of FIG. 1. A simplified cross-sectional view taken from lines - and -, respectively, FIG. 5 is a prior art cross-sectional view. DESCRIPTION OF SYMBOLS 1... Copy paper, 4... Heat roller, 5... Pressure roller, 9, 10... Casing, 20... Oil application means, 24... Blade, 25... Oil pan, 26...
...Sheet, 31...Positive characteristic thermistor, 32...
Power switch, 33...Control device, 34...Plug.

Claims (1)

[Claims for Utility Model Registration] It has a heat source 8 on at least one side, and a pair of rollers 4 and 5 arranged above and below, and the copy paper 1 is passed between these rollers 4 and 5 to heat and fix it. In the heat fixing device, the upper and lower rollers 4 and 5 are at their contact position 15.
The upper and lower casings 9 and 10 are open facing the
The upper roller 4 is provided at both ends of the first central thermal fixing section 4a and the first central thermal fixing section 4a, and is surrounded by a first central thermal fixing section 4a.
Oil guide portions 27, 2 having a smaller diameter than the central heat fixing portion 4a
8, and the first central heat fixing section 4a of the upper roller 4 has a
An oil coating piece 22 is applied over the entire length of the central heat fixing section 4a.
An oil application means 20 is provided for applying oil by contacting the first central heat fixing section 4a of the upper roller 4, and a blade 24 is provided for scraping oil applied to the circumferential surface of the first central heat fixing section 4a of the upper roller 4, and the blade 24 and the oil application Means 20 is
along the rotational direction in a range that is forward of the rotational direction of the upper roller 4 than a vertical line passing through the axis of the upper roller 4 and rearward of the contact position 15 of the upper and lower rollers 4 and 5 in the rotational direction. The ends 29 and 30 of the blade 24 extend halfway in the longitudinal direction of the oil guide parts 27 and 28, and the lower roller 5 connects the second central heat fixing part 5a and the second central heat fixing part 5a. Lower roller shafts 47 and 48 are provided at both ends in the longitudinal direction of the second central heat fixing section 5a and have a diameter smaller than that of the second central heat fixing section 5a. , is arranged in the casing 10 directly below the oil guide parts 27 and 28 via a support member, and the second central heat fixing part 5a of the lower roller 5 is formed shorter than the first central heat fixing part 4a of the upper roller 4. The second central heat fixing section 5a of the lower roller 5 is connected to the first central heat fixing section 4 of the upper roller 4 over its entire length.
a, is removably disposed inside the lower casing 10 and horizontally directly below the lower roller 5, is spaced downward from the lower roller 5, and extends in the axial direction over the entire length of the upper and lower rollers 4 and 5. an oil pan 25 that extends and spreads on both sides of the axes of the upper and lower rollers 4 and 5; and an oil absorbent that is disposed within the oil pan 25 at a distance from the lower roller 5 and below, and that is removable from the oil pan 25. a sheet 26, and an oil pan 25 is positioned within the lower casing 10 at a position where it can receive oil dripping from the rollers 4 and 5.