JP6297875B2 - Peeling member - Google Patents

Description

  The present invention relates to a peeling member that peels a sheet from various rollers installed in an electrophotographic apparatus such as a copying machine or a laser beam printer, and more particularly to a peeling member for a fixing member such as a fixing roller.

  Various types of rollers are provided in electrophotographic apparatuses such as copying machines and laser beam printers for developing electrostatic latent images formed on photosensitive drums onto paper using a developer such as toner and then fixing them. It has been. Except for the photosensitive drum and the dry electrophotographic apparatus, the developing unit includes an oil application roller, and the fixing unit includes a fixing roller and a pressure roller. Conventionally, a photosensitive drum, a fixing roller, a pressure roller, and the like are provided with a separation claw to prevent a sheet from being wound around the roller and hindering smooth operation. The separation claw prevents the paper from being wound around the roller by scooping up the edge of the paper while sliding the tip of the separation claw on the outer peripheral surface of the roller. The width of the contact portion of the separation claw with the roller is about 1 to 10 mm, and 4 to 16 pieces are arranged for one roller. Since the separation claw is in local contact with the roller, the roller is inevitably partially worn and a good image cannot be obtained. Also, since the paper is locally contacted with the paper, it is easy to scrape off the developer transferred to the paper, and the paper that is scraped off may adhere to the separation claw and the paper may be easily soiled. .

  For such a problem, as a peeling member capable of line contact with a roller of an electrophotographic apparatus, a peeling sheet made of a thin metal plate that peels paper from the roller is joined to a metal support member by laser spot welding. A peeling member has been proposed (see Patent Document 1). This release member can be in line contact with the roller by a release sheet, and can prevent local wear of the roller.

  Also, as the separation plate (peeling member) of the electrophotographic apparatus, in order to roll the leading end portion of the separation plate and provide a gap with the mating roller at both end portions, abutting portions made of the same metal plate as the separation plate are provided. A provided separating plate has been proposed (see Patent Document 2).

JP 2002-91222 A JP 2006-171551 A

  The peeling member of Patent Document 1 is a structure that supports the precision of the leading edge of the peeling sheet by supporting the peeling sheet, which is a thin plate, by a support member that is a metal base plate. Is possible. Moreover, since the support member and the release sheet are joined by laser spot welding, the joining force is thermally stabilized as compared with the case where the release sheet and the support member are joined by an adhesive. For this reason, generation | occurrence | production of the corrugation phenomenon of this peeling sheet can be suppressed, using the peeling sheet which is a thin plate. Note that the undulation phenomenon refers to a phenomenon in which the release sheet and the support member are partially peeled to cause undulations in the release sheet and the paper cannot be smoothly peeled off.

  However, in order to weld the release sheet to the support member by laser spot welding, equipment such as a laser irradiation device and a dedicated jig is required, which increases the manufacturing cost. In addition, depending on the material of the release sheet and the support member, it is difficult to weld with sufficient bonding strength, and the undulation phenomenon may not be suppressed.

  On the other hand, in patent document 2, since a peeling part (front-end | tip part) and its support part are comprised from the same metal plate, the problem relevant to joining does not arise. However, the separation plate of Patent Document 2 cannot be finely adjusted because the gap amount with the mating roller is determined by the height of the abutting portions at both ends. For this reason, depending on the accuracy of the mating roller or the like, it is necessary to perform assembly by matching after measuring the dimensional accuracy for each assembly, which takes man-hours. Further, even if a problem occurs in which the mating roller wears at the abutting portion, the gap amount cannot be changed and cannot be dealt with.

  The present invention has been made in order to cope with such a problem, suppresses the undulation phenomenon of the release sheet portion, makes sufficient line contact with the roller, and does not damage the counterpart roller at the contact portion, and is excellent. It is an object of the present invention to provide a peeling member that can exhibit the paper peeling performance.

  The peeling member of the present invention is a peeling member that peels paper from a roller of an electrophotographic apparatus, and the peeling member is made of a single metal plate, and has a tip portion (long side opposite to the support portion) on the roller. A release sheet portion that contacts or approaches an end portion) and a support portion that is thicker than the release sheet portion, and the release sheet portion is formed by rolling one long side of the metal plate, The thickness is constant in the longitudinal direction, and the sheet passing surface is a flat surface.

  Here, “contact” means that one side (tip portion) of the release sheet portion is in line contact with the axial direction of the roller. Further, “close” means that one side (tip portion) of the release sheet portion is arranged close to the roller to such an extent that the paper can be prevented from being wound around the roller. The rollers of the electrophotographic apparatus are, for example, a photosensitive drum, a fixing roller (including a belt roll), a pressure roller, and the like.

  The thickness of the most advanced portion of the release sheet portion is 0.05 to 0.4 mm.

  In the support portion, a plurality of concave portions having a shape fixed to a mating member and opened to the outside of the end portion are formed apart from each other along the longitudinal direction at an end portion opposite to the release sheet portion. It is characterized by.

  The release sheet portion is formed by rolling the short side and the long side to a predetermined dimension after rolling to the short side and the long side which is the tip. .

  The release member is formed by attaching a non-adhesive resin film to at least a paper passing surface of the release sheet portion via a silicone adhesive, and the non-adhesive resin film is made of polytetrafluoroethylene (PTFE) resin, tetra At least one fluorine selected from fluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) resin, tetrafluoroethylene-hexafluoropropylene copolymer (FEP) resin, and tetrafluoroethylene-ethylene copolymer (ETFE) resin It is a resin film.

  Since the peeling member of the present invention is composed of a single metal plate having a peeling sheet portion that makes the tip portion contact or approach the roller of the electrophotographic apparatus and a support portion that is thicker than the peeling sheet portion, laser welding is performed. No special jig or a laser generator is required, and the peeling member can be manufactured at low cost. In addition, there is no influence of heat, there is no variation in the bonding force due to a problem when joining a plurality of members, and no undulation phenomenon occurs. For this reason, the front-end | tip part of a peeling sheet part can be stably contacted or adjoined to a roller over a long period of time, and a paper can be peeled smoothly. Further, the release sheet portion is formed by rolling one long side of the metal plate, and has a constant thickness in the longitudinal direction, and its sheet passing surface is a flat surface. Does not damage the roller.

  Since the thickness of the foremost portion of the release sheet portion is 0.05 to 0.4 mm, it is possible to apply a pressure contact force to the roller for securing the release force and to prevent the occurrence of jamming.

  In the support portion, a plurality of concave portions having a shape fixed to the mating member and opened to the outside of the end portion are formed apart from each other in the longitudinal direction at the end opposite to the seat portion. Therefore, when fixing to a support part using a some recessed part, the distance between a front-end | tip part and a roller can be adjusted separately.

  The release sheet portion is formed by cutting the short side and the long side into predetermined dimensions after being rolled to the short side and the long side which is the tip. Can be prevented, and the accuracy of the tip 2a of the release sheet 2 is excellent.

  The release member has a non-adhesive resin film affixed to at least the sheet-passing surface of the release sheet portion via a silicone-based adhesive, so it can be firmly adhered to the release sheet portion and the adhesive effect can be maintained even at the fixing temperature. Excellent in high temperature durability. Moreover, the cushion effect by an adhesive can also be expected. Furthermore, since this non-adhesive resin film is at least one fluororesin film selected from PTFE resin, PFA resin, FEP resin, and ETFE resin, the effect of preventing adhesion of toner is very high and low friction with the paper. Excellent characteristics.

It is a schematic diagram of a fixing device using the peeling member of the present invention. It is a partial perspective view which shows an example of the peeling member of this invention. It is a partial perspective view which shows the example which stuck the non-adhesive resin film to the peeling member of FIG. FIG. 4 is a cross-sectional view (end view) of the peeling member of FIG. 3. It is the schematic which shows the manufacturing process of the peeling member of this invention.

  A fixing device using the peeling member of the present invention will be described with reference to FIG. FIG. 1 is a schematic diagram of a heat roller type fixing device using a peeling member. The fixing device includes a heater 6a, and includes a fixing roller 6 that rotates in the direction of arrow A, a pressure roller 7 that contacts the fixing roller 6 and rotates in the direction of arrow B, and the fixing roller 6 and the pressure roller 7 It is comprised from the peeling member 1 arrange | positioned in the vicinity of the nip part 8 formed in contact. The toner image formed on the paper 9 is fixed at the nip portion 8 and becomes a fixed image. The support part 3 of the peeling member 1 is fixed to the support member 10 which is another member with a bolt 5. The leading end portion of the release sheet portion 2 constituting the release member 1 is disposed at a position in contact with or close to the fixing roller 6 so that the sheet 9 that has passed through the nip portion 8 can be released from the fixing roller 6.

  An example of the peeling member of the present invention will be described with reference to FIG. FIG. 2 is a partial perspective view of the peeling member. As shown in FIG. 2, the peeling member 1 is composed of a single metal plate (substantially long flat plate), and includes a peeling sheet portion 2 that is a rolled portion and a support portion 3 that is thicker than the peeling sheet portion 2. Composed. The planar shape of the peeling member 1 is a substantially rectangular shape. The black arrow in the figure is the sheet passing direction, and the longitudinal direction of the peeling member 1 and the sheet passing direction are orthogonal to each other. The front end portion 2a of the release sheet portion 2 is an upstream side in the sheet passing direction, and is an end portion on the one long side of the release sheet portion. The release sheet portion 2 has a flat sheet passing surface 2b and does not have an uneven portion such as an abutting portion. The sheet passing surface 3 b of the support portion 3 is flush with the sheet passing surface 2 b of the release sheet portion 2, and these constitute the sheet passing surface of the release member 1. The peeling member 1 arranges the front end portion 2a of the peeling sheet portion 2 at a position in contact with or close to various rollers such as a fixing roller, and picks up an end portion of the paper peeled off from the roller (see FIG. 1).

  The release sheet portion 2 is formed by rolling one long side of a metal plate, and has a constant thickness in the longitudinal direction. One long side of the metal plate is rolled in the longitudinal direction with a press and then cut into a predetermined dimension. At this time, in the metal plate, not only the long side of the rolled part (the end part side of the release sheet part) but also the short side is subjected to slit processing and then rolled with a press. It is preferable to cut the side (tip side) to a predetermined dimension. Thereby, the deformation | transformation at the time of use etc. can be prevented and the precision of the front-end | tip part 2a of the peeling sheet part 2 is excellent.

  The thickness of the support part 3 is constant and is the thickness of the metal plate before rolling. In the support portion 3, a plurality of concave portions 3 c which are fixing portions to the support member are spaced apart along the longitudinal direction at an end portion 3 a (an end portion on the downstream side in the paper passing direction) opposite to the release sheet portion 2. Is formed. The number and interval of the recesses 3c are set as appropriate. The recess 3c is formed by drawing or the like. The recess 3c has a shape opened to the outside of the end 3a. The longitudinal deformation of the recess 3c due to the drawing process is preferably cut to a predetermined size, so that the accuracy of the support portion is not deteriorated during the drawing process. The recess 3c has a bolt hole 3d for fixing the bolt, and the depth of the recess 3c is preferably deeper than the height of the head of the bolt (see FIG. 4C described later).

  As a material of the metal plate constituting the peeling member 1, iron, aluminum, copper, stainless steel, or the like can be used. In particular, stainless steel is preferable because it does not rust, is easy to process, and is inexpensive. The thickness of the metal plate is preferably in the range of 1 to 5 mm, and the thickness of the most advanced portion of the release sheet portion 2 that is a rolled portion is preferably in the range of 0.05 to 0.4 mm. If it is less than 0.05 mm, there is a possibility that the pressure contact force to the roller for securing the peeling force may not be applied. If it exceeds 0.4 mm, the paper to be peeled will hit the leading end 2 a of the peeling sheet portion 2. This may cause jamming. The thickness of the release sheet portion is constant in the longitudinal direction, but may be constant in the sheet passing direction (same as the most advanced portion) or may gradually increase in thickness toward the support portion 3. Further, the width of the release sheet portion (width in the paper passing direction) is preferably long, preferably 2 to 20 mm, and more preferably 3 mm or more and less than 10 mm.

  The release sheet portion 2 has a contact width that is substantially the same as the axial length of the roller. Since the contact width is large, the contact pressure per unit area to the roller is reduced, and local wear on the roller surface can be prevented. The length substantially the same as the length of the roller in the axial direction refers to a length to the extent that the above effect can be obtained. Specifically, the length is at least about half of the length in the axial direction of the roller. Same or slightly longer.

  The release sheet portion 2 is preferably applied with a lubricating coating or a non-adhesive resin film so as to improve the paper release performance on at least the paper passing surface of the front end portion 2a. In particular, it is preferable to apply a non-adhesive resin film because of excellent paper peeling performance and high temperature durability.

  3 and 4 show an example in which a non-adhesive resin film is attached to the peeling member of FIG. FIG. 3 is a partial perspective view of a peeling member to which a non-adhesive resin film is attached, and FIG. 4A is a cross-sectional view (end view) including a concave portion for fixing a bolt of the peeling member. ) Is a cross-sectional view (end view) of a portion without the concave portion, and FIG. 4C is a cross-sectional view (end view) including a support member. In the example shown in FIGS. 3 and 4, the non-adhesive resin film 4 is pasted from the paper passing surface 2 b to the anti-paper passing surface 2 c so as to cover the front end portion 2 a of the release sheet portion 2. Furthermore, the non-adhesive resin film 4 is affixed over the paper passing surface 3b of the support part 3 which is flush.

  The non-adhesive resin film is a resin film having non-adhesive properties to such an extent that developer adhesion can be prevented. For example, a polyethylene resin film, a polypropylene resin film, and PTFE resin, PFA resin, FEP resin, ETFE resin A film made of a known fluororesin such as polychlorotrifluoroethylene resin, chlorotrifluoroethylene-ethylene copolymer resin, polyvinylidene fluoride resin, polyvinyl fluoride resin, or the like can be used. In particular, a fluororesin film made of PTFE resin, PFA resin, FEP resin, or ETFE resin is excellent in non-adhesiveness to color toner (such as toner using a polyester binder resin) and has sufficient heat resistance. Have. If the non-adhesive property for the toner can be ensured, the non-adhesive resin film is formed from a non-adhesive resin blended with fine carbon powder such as ketjen black or acetylene black, thereby removing the paper due to static electricity. It is also possible to prevent a decrease in performance.

  The thickness of the non-adhesive resin film such as a fluororesin is preferably in the range of 10 to 200 μm, and more preferably in the range of 40 to 80 μm. When the thickness is less than 10 μm, there is a risk of tearing due to friction with the developer, or there is a possibility that the tip of the release sheet portion is exposed due to slight wear. Moreover, it becomes easy to become a wrinkle in the sticking process to a peeling member, and handling becomes difficult. When the thickness exceeds 200 μm, the paper peeling performance deteriorates.

The non-adhesive resin film is preferably attached to the release member by interposing an adhesive, particularly a silicone adhesive, on the application surface. For example, a non-adhesive resin film in which a silicone-based adhesive is previously attached to the surface to be attached to the peeling member is used. Examples of the silicone-based pressure-sensitive adhesive include pressure-sensitive adhesives obtained by condensing a copolymer composed of SiO ₂ units and (CH ₃ ) ₃ SiO units and diorganopolysiloxane raw rubber. By interposing the silicone-based pressure-sensitive adhesive, it is firmly bonded to the peeling member and can maintain the bonding effect even at the fixing temperature, and a cushioning effect by the pressure-sensitive adhesive can also be expected. In addition, in order to enhance the adhesion effect, it is desirable to perform surface treatment such as corona discharge treatment, sputter etching treatment, plasma etching treatment, TOS treatment with metallic sodium, and ultraviolet irradiation treatment on the surface to be attached to the peeling member.

  The thickness of the silicone pressure-sensitive adhesive layer may be in the range of 5 to 50 μm. If the thickness is less than 5 μm, a sufficient adhesion effect cannot be obtained. On the other hand, if the thickness is greater than 50 μm, the thickness of the peeling member becomes relatively large, and the paper peeling performance may be deteriorated. In addition, the non-adhesive resin film can be attached to the release sheet portion without interposing an adhesive. For example, after roughening the pasting surfaces (paper passing surfaces 2b, 3b) of the peeling member by plasma etching or the like, a method of thermocompression bonding the non-adhesive resin film can be mentioned.

  A fixing structure between the peeling member and the support member will be described with reference to FIG. As shown in FIG. 4C, in the peeling member 1, the support portion 3 is fixed to the support member 10 that is another member with a bolt 5. The bolt 5 is fixed to the support member 10 through the bolt hole 3d of the recess 3c. By preventing the head of the bolt 5 from protruding from the recess 3c when the bolt is fastened, it is possible to prevent the paper peeling performance from being deteriorated. When the peeling member is a thin plate or the like, it is necessary to support the vicinity of the tip with a support member in order to ensure the accuracy of the tip that contacts the roller. On the other hand, since the peeling member 1 of the present invention has the release sheet portion 2 and the support portion 3 integrated, if only the support portion 3 is supported by the support member 10 of another member, the peeling member 1 can be peeled stably. The sheet part 2 is also supported. For this reason, the horizontal precision of the front-end | tip part 2a of the peeling sheet part 2 which has a big influence on peeling performance can be maintained high, and the outstanding paper peeling performance can be exhibited.

[Example 1]
A peeling member was manufactured by processing a stainless steel (SUS304CSP) coil having a thickness of 1.5 mm with a progressive press die. A manufacturing process is demonstrated based on FIG. FIG. 5 is a schematic view of the manufacturing process, the left side (A) to (G) are plan views, and the right side (a) to (g) are cross-sectional views. First, slits 21 were formed on the steel plate 20 shown in FIG. The slit 21 was formed by punching the steel plate 20 with a press die over both the long side 22a and both short sides 22b of the rolling region 22. Next, the rolling area | region 22 was pressed with the press die 30 shown to (a), and thickness was rolled to 0.2 mm, and the rolling part 23 shown to (B) and (b) was formed.

  In order to form a recess for fixing the peeling member, a portion corresponding to the slit was punched out with a press die 31 shown in (c) in order to form a slit 24 shown in (C) on the counter-rolling side. Next, the recess 3c shown in (D) was formed by drawing using the press dies 32 and 33 shown in (d). Thereafter, a bolt hole 3d in the recess 3c shown in (E) was formed by punching with a press die 34 shown in (e).

  In order to obtain the accuracy of the tip of the rolled portion, the long side and both short sides of the rolled portion are punched into the shape shown in (F) with the press die 35 shown in (f), and at the same time the anti-rolled side is pressed with the press die 36. Punched out. Note that this step does not have to be performed at the same time, and may be a separate step. Finally, as shown in (G) and (g), the peeling member 1 which is a product was separated from the steel plate 20. The peeling sheet part 2 consists of the rolling part 23 rolled to 0.2 mm.

  Next, a fluororesin film was pasted across the paper passing surface of the release sheet portion 2 and the paper passing surface of the support portion 3. As the fluororesin film, a PTFE film having a thickness of 50 μm (Bearly FL3090 manufactured by NTN Precision Resin Co., Ltd.) was prepared, and an etching process was performed in which the surface to be attached to the peeling member was immersed in an ammonia solution of metallic sodium. A silicone-based pressure-sensitive adhesive solution containing dimethylpolysiloxane raw rubber (KR101 manufactured by Shin-Etsu Chemical Co., Ltd.) was uniformly applied to the etched surface of this fluororesin film and dried by heating at 120 to 200 ° C. Thereafter, it was naturally cooled to room temperature to form a silicone adhesive layer having a thickness of about 30 μm.

  In the pasting process, the fluororesin film is laid on a smooth plate so that the surface having the pressure-sensitive adhesive layer does not become wrinkled, and then the tip of the release sheet is chamfered and thoroughly degreased with petroleum benzine. After that, a roller contact part (tip part of the release sheet part) with rounded corners was arranged at a substantially central part of the fluororesin film. The film was affixed to the surface of the release sheet portion with this roller contact portion as a boundary. Thus, the peeling member which adhered the fluororesin film through the silicone adhesive as shown in FIG. 4 was obtained.

  This peeling member is set in a fixing portion of a test copying machine (fixing temperature 190 ° C., A4 copying speed 57 sheets / min), a line chart with an image ratio of 30% is used as a document, and A4 plain paper is used to print 5000 sheets. The copying test by continuous paper passing was performed up to 30000 sheets. The test machine was stopped every 5000 sheets and the presence or absence of image degradation was confirmed by visual observation of the copied paper. Further, the peeling member was removed from the fixing portion, and the wear of the fluororesin film, the presence or absence of toner adhesion, and the wear state of the fixing roller were confirmed.

  As a result of the test, the image of the peeling member of Example 1 was not lowered until the end of the 30000 sheet passing test, and the fluororesin film confirmed after the end of the sheet passing test was not damaged. Further, no toner adhered to the release sheet portion, and no wear of the fixing roller was observed.

[Comparative Example 1]
A thin metal plate (release sheet) made of stainless steel (SUS304CSP) having a thickness of 200 μm was cut into a contact width (L) of 310 mm and a width of 25 mm, and the inner width of 5 mm and the length of 310 mm were bent at right angles. Next, recesses were provided at five locations on the bent metal sheet so that the bolt heads did not completely protrude from the 20 mm wide surface of the metal sheet, and bolt holes were provided on the bottom surface of the recess. The thin plate and the metal support plate were joined to each other with RTV-KE1800ABC made by Shin-Etsu Chemical, which is a silicone rubber adhesive, and a fluororesin film was attached in the same manner as in Example 1. The same evaluation as in Example 1 was performed. When the test was conducted, the entire joint of the release sheet was peeled off.

  The peeling member of the present invention suppresses the undulation phenomenon of the peeling sheet portion, can sufficiently make line contact with the roller, and can exhibit excellent paper peeling performance without damaging the partner roller at the contact portion. It can be suitably used as a peeling member for peeling paper from various rollers such as a fixing roller installed in the apparatus.

DESCRIPTION OF SYMBOLS 1 Release member 2 Release sheet part 3 Support part 4 Non-adhesive resin film 5 Bolt 6 Fixing roller 7 Pressure roller 8 Nip part 9 Paper 10 Support member 20 Steel plate (metal plate)
21, 24 Slit 22 Rolling region 23 Rolling part 30-36 Press die

Claims (4)

A peeling member for peeling paper from a roller of an electrophotographic apparatus,
The release member is made of a single metal plate, and has a release sheet portion that contacts or approaches a tip portion of the roller, and a support portion that is thicker than the release sheet portion,
The release sheet portion is a rolled portion formed by rolling one long side of the metal plate, and has a constant thickness in the longitudinal direction, and a flat surface having no protrusions on the paper passing surface and the anti-paper passing surface. der is,
In the support portion, a plurality of concave portions having a shape fixed to a mating member and opened to the outside of the end portion are formed apart from each other along the longitudinal direction at an end portion opposite to the release sheet portion. peeling member, wherein Tei Rukoto.   The peeling member according to claim 1, wherein a thickness of the most distal portion of the peeling sheet portion is 0.05 to 0.4 mm. The release sheet portion is formed by rolling the short side and the long side to a predetermined dimension after rolling to the short side and the long side which is the tip. The peeling member according to claim 1 or 2. The release member is formed by attaching a non-adhesive resin film via a silicone-based adhesive to at least the paper passing surface of the release sheet portion,
The non-adhesive resin film is composed of a polytetrafluoroethylene resin, a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin, a tetrafluoroethylene-hexafluoropropylene copolymer resin, and a tetrafluoroethylene-ethylene copolymer resin. The release member according to any one of claims 1 to 3 , wherein the release member is at least one fluororesin film selected.

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