JP2006126412A - Image forming apparatus and assembling method for toner-scraping member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus, equipped with a toner-scraping member which has an easy-to-assembly constitution and can surely and reasonably scrape the toner adhered to the conveyor screw carrying toner and prevent a toner conveyance path from being clogged, even when a large amount of toner is transported. <P>SOLUTION: The image forming apparatus is equipped with the conveyor screw which carries the toner through the rotation of a screw blade, the toner scraping member having an abutting portion which abuts against the screw blade from the axial direction of the conveyor screw and swings, and a holding member which holds the toner-scraping member, and the abutting portion is inserted into a long hole bored in the holding member from the back surface side facing the conveyor screw. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a multifunction machine having these functions, and includes a toner scraping member that scrapes off toner adhering to a conveying screw that conveys toner. The present invention relates to an image forming apparatus and a method for assembling a toner scraping member.

  In an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a multifunction machine having these functions, an image carrier such as a uniformly charged photosensitive drum is exposed in accordance with image data. An electrostatic latent image is formed. A toner is attached to the electrostatic latent image by a developing device to make it visible and transferred directly to a recording material, or transferred to an intermediate transfer belt and then transferred to a recording material. Subsequently, the toner image transferred to the recording material is fixed by heating and pressing with a fixing device.

  When transferring the toner image, 100% transfer is impossible, and a small amount of toner (hereinafter referred to as transfer residual toner) remains on the photosensitive drum or the intermediate transfer belt. In order to continuously perform the above-described image forming process, it is necessary to remove the transfer residual toner. Therefore, a cleaning device is provided to remove and collect the transfer residual toner.

  In the cleaning device, the transfer residual toner is scraped off from the photosensitive drum or the intermediate transfer belt by a cleaning blade or the like, and the transfer residual toner scraped off falls to the bottom of the cleaning device. At the bottom of the cleaning device, a toner transport path for transporting the dropped transfer residual toner is provided, and a transport screw having screw blades formed in a spiral shape is disposed in the toner transport path, and the screw blades are rotated. The untransferred toner is conveyed by. The untransferred toner conveyed by the conveying screw is collected in a toner collection box provided outside the cleaning device and discarded, or is conveyed to the developing device and reused.

  When the image forming apparatus is placed in a high humidity environment, transfer residual toner adheres to the conveying screw due to in-machine condensation or toner absorption. As the transfer residual toner gradually increases, the toner transport path becomes clogged, and the transfer residual toner is not transported outside the cleaning device but is accumulated in the toner transport route, so that the transfer residual toner is full in the cleaning device. If this happens, the cleaning action is lost. In some cases, the cleaning device may be damaged.

  Therefore, in order to prevent the transfer residual toner from adhering to the conveying screw, a large number of elastic protruding pieces are formed at the tip of an elastic plate such as a polyester film, and the elastic protruding pieces are elastically formed from the outer peripheral direction of the conveying screw. There has been proposed a cleaner unit which is made to abut and swing so as to scrape off transfer residual toner adhering to the conveying screw (see Patent Document 1).

In addition, a swing member is provided on the side wall of the lower opening for discharging the toner in the detection container for detecting the toner concentration, and the tip of the swing member is swung by contacting the conveying screw, so that the toner discharged from the detection container A developing device that prevents clogging has been proposed (see Patent Document 2).
JP-A-5-224562 JP-A-6-282168

  In order to prevent the transfer residual toner from adhering to the conveying screw, in the configuration described in Patent Document 1, a plurality of flat elastic protruding pieces are arranged between screw blades of the conveying screw, and the elastic protruding pieces are arranged. The screw blade is deformed and swung in the outer peripheral direction of the screw blade, that is, in the plate thickness direction. However, in reality, the elastic protrusions are subjected to a force in the axial direction of the conveying screw, that is, in a direction parallel to the plate surface by the rotation of the screw blades, but the elastic protrusions are not easily deformed in the same direction. Will be evacuated. For this reason, the screw blade is subjected to a large resistance by the elastic protrusion, and particularly when a large amount of untransferred toner is conveyed, the durability of the screw blade and the elastic protrusion is greatly affected. In addition, since a large rotational torque is required for the rotation of the conveying screw due to the resistance of the elastic protrusion, the power consumption of the driving device increases. In addition, it is expected that the transfer residual toner dropped from above adheres to and accumulates on the flat elastic protrusions. As a result, the elastic protrusions are difficult to swing, and there is a problem in durability and power consumption. Will occur.

  In the configuration described in Patent Document 2, there is only one swing member, which is intended to prevent clogging of the toner discharged from the detection container, and the transfer residual toner adheres to the conveying screw. It is not intended to prevent this.

  The present invention has been made in view of the problems described above, and has a configuration that can be easily assembled, and scrapes toner adhering to a conveying screw that conveys toner reliably and without giving a large resistance to the conveying screw. An image forming apparatus having a toner scraping member that can prevent clogging of a toner transport path even when a large amount of toner is transported and that hardly deposits toner dropped from above, and toner An object is to propose a method for assembling a scraping member.

  The above object is achieved by the following means.

  [Claim 1] A conveying screw that conveys toner by rotation of a screw blade, a toner scraping member having an abutting portion that contacts and swings from the axial direction of the conveying screw, and the toner scraping An image forming apparatus comprising: a holding member that holds a member; and the contact portion is inserted into a long hole provided in the holding member from a back side with respect to the conveying screw.

  [Claim 2] The toner scraping member has a support portion for supporting the contact portion, and after the contact portion has penetrated into the elongated hole, the support portion is a back surface of the holding member with respect to the conveying screw. The image forming apparatus according to claim 1, wherein the image forming apparatus is attached to the side.

  [Claim 3] The toner scraping member is formed of a thin plate, and the surface portion of the contact portion is disposed substantially orthogonal to the axial direction of the conveying screw. The image forming apparatus described in 1.

  [Claim 4] The image forming apparatus according to any one of claims 1 to 3, wherein a surface portion of the contact portion of the toner scraping member is disposed substantially parallel to a vertical direction.

  [Claim 5] The toner scraping member is formed in a U-shape having a first abutting portion, a second abutting portion, and a support portion connecting the abutting portions. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.

  [Claim 6] A plurality of elongated holes are provided in the holding member in the axial direction of the conveying screw, and contact portions of the plurality of toner scraping members are inserted into the plurality of elongated holes. The image forming apparatus according to claim 1.

  [7] The image forming apparatus according to any one of [1] to [6], wherein the toner scraping member is made of polyethylene.

  [8] The toner is transfer residual toner collected by a cleaning means, and the transport screw, the toner scraping member, and the holding member are disposed in a toner transport path for transporting the transfer residual toner. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.

  [9] The image forming apparatus according to [8], wherein a holding member holding the toner scraping member is fixed to a side wall forming the toner conveyance path.

  [Claim 10] A method of assembling a toner scraping member that contacts a conveying screw that conveys toner by rotation of a screw blade, wherein the toner scraping member is brought into contact with the screw blade from the axial direction of the conveying screw. A method of assembling the toner scraping member, comprising: a step of penetrating the contact portion provided on the back side of the conveying screw into a long hole provided in a holding member that holds the toner scraping member.

  [11] The method according to [10], further comprising the step of abutting a support portion provided on the toner scraping member to support the abutting portion on a back side of the holding member with respect to the conveying screw. A method for assembling the toner scraping member.

  [12] A step of disposing a holding member holding the toner scraping member in a toner transport path for transporting toner, and a step of fixing the holding member to a side wall forming the toner transport path. The method for assembling the toner scraping member according to claim 10 or 11, wherein:

  [13] The toner scraping member is formed of a thin plate, and has a step of arranging the surface portion of the contact portion substantially perpendicular to the axial direction of the conveying screw. The method for assembling the toner scraping member according to any one of the above items.

  [14] The toner scraping-off according to any one of [10] to [13], further comprising a step of arranging a surface portion of the contact portion of the toner scraping member substantially parallel to a vertical direction. Assembling method of members.

  According to the image forming apparatus of the first and second aspects, the toner can be easily assembled and scraped off the toner adhering to the conveying screw for conveying the toner reliably and without giving a large resistance to the conveying screw. Therefore, even when a large amount of toner is transported, clogging of the toner transport path can be prevented.

  According to the image forming apparatus of the third aspect, since the toner scraping member is a thin plate, it is elastically rocked in the axial direction of the conveying screw, and the toner adhering to the conveying screw is reliably and reasonably scraped off. be able to. Therefore, no great resistance is applied to the conveying screw, and there is no problem in durability performance or power consumption.

  According to the image forming apparatus of the fourth aspect, since the toner dropped from above is very rarely deposited on the toner scraping member, the swinging operation of the toner scraping member is not affected.

  According to the image forming apparatus of the fifth and sixth aspects, it is possible to cope with a long conveying screw.

  According to the image forming apparatus of the seventh aspect, since the sliding performance between the toner scraping member and the conveying screw is good and the frictional resistance is small, the durability performance is improved.

  According to the image forming apparatus of the eighth and ninth aspects, the above effect is effective when the toner is the transfer residual toner collected by the cleaning unit.

  According to the method for assembling the toner scraping member according to claim 10, the toner scraping can reliably scrape off the toner adhering to the transport screw that transports the toner without giving a large resistance to the transport screw. The members can be assembled easily and reliably.

  According to the method for assembling the toner scraping member according to the thirteenth aspect, the toner scraping member can be assembled so that the toner adhering to the conveying screw can be scraped off without fail.

  According to the assembling method of the toner scraping member according to the fourteenth aspect, the toner scraping member can be assembled so that the toner dropped from the upper side is very unlikely to accumulate on the toner scraping member.

  The image forming apparatus of the present invention will be described below with reference to the drawings.

  First, an example of an image forming apparatus will be described with reference to FIG. FIG. 1 is a cross-sectional configuration diagram of an image forming apparatus for forming a color image. The present invention is not necessarily used only in an image forming apparatus that forms a color image, but is also used in an image forming apparatus that forms a monochrome image.

  The color image forming apparatus shown in FIG. 1 includes an image forming apparatus 100 and an image reading apparatus 200.

  The image forming apparatus 100 is referred to as a tandem color image forming apparatus, and includes a plurality of sets of image forming units 10Y, 10M, 10C, and 10K, a belt-shaped intermediate transfer member 6, a sheet feeding / conveying unit 20, and a belt fixing device. It consists of 30 mag.

  An image reading device 200 including an automatic document feeder 201 and a document image scanning exposure device 202 is installed on the upper part of the image forming apparatus 100.

  The document d placed on the document table of the automatic document feeder 201 is transported by a transport unit, and an image on one or both sides of the document is scanned and exposed by the optical system of the document image scanning exposure device 202, and the line image sensor CCD is scanned. Is read.

  The analog signal photoelectrically converted by the line image sensor CCD is subjected to analog processing, A / D conversion, shading correction, image compression processing, etc. in the image processing unit 101, and then to the exposure means 3Y, 3M, 3C, 3K. Entered.

  The image forming unit 10Y that forms a yellow image includes a photosensitive drum 1Y as an image carrier, a charging unit 2Y, an exposure unit 3Y, a developing unit 4Y, a cleaning device 5Y, and a primary unit arranged around the photosensitive drum 1Y. It comprises a primary transfer roller 7Y as a transfer means.

  The image forming unit 10M that forms a magenta image includes a photosensitive drum 1M as an image carrier, a charging unit 2M arranged around the photosensitive drum 1M, an exposing unit 3M, a developing unit 4M, a cleaning device 5M, a primary unit. It comprises a primary transfer roller 7M as a transfer means.

  The image forming unit 10C for forming a cyan image includes a photosensitive drum 1C as an image carrier, a charging unit 2C disposed around the photosensitive drum 1C, an exposure unit 3C, a developing unit 4C, a cleaning device 5C, a primary unit. It comprises a primary transfer roller 7C as transfer means.

  The image forming unit 10K that forms a black image includes a photosensitive drum 1K as an image carrier, a charging unit 2K arranged around the photosensitive drum 1K, an exposure unit 3K, a developing unit 4K, a cleaning device 5K, a primary transfer unit. It comprises a primary transfer roller 7K as a means.

  The developing means 4Y, 4M, 4C, 4K are yellow (Y), magenta (M), cyan (C), or black (K) charged to the same polarity as the charging polarity of the photosensitive drums 1Y, 1M, 1C, 1K. The two-component developer (which may be a one-component developer) made of each color toner is accommodated, and is formed of, for example, a cylindrical nonmagnetic stainless steel or aluminum material having a thickness of 0.5 to 1 mm and an outer diameter of 15 to 25 mm. And developing rollers 4Y1, 4M1, 4C1, and 4K1, which are developer carriers.

  The developing rollers 4Y1, 4M1, 4C1, and 4K1 are maintained in a non-contact manner by providing a predetermined gap, for example, a gap of 100 to 1000 μm, with the photosensitive drums 1Y, 1M, 1C, and 1K by an abutting roller (not shown). The drums 1Y, 1M, 1C, 1K rotate in the forward and reverse directions.

  By applying a developing bias voltage that superimposes an AC voltage on the DC voltage or DC voltage having the same polarity as the toner to the developing rollers 4Y1, 4M1, 4C1, and 4K1 during development, the photosensitive drums 1Y, 1M, 1C, and 1K are Reversal development is performed on the electrostatic latent image.

  Generally, so-called external additives are added to toners for the purpose of improving fluidity and cleaning properties. Among these, as a lubricant related to the present invention, for example, zinc stearate is used. Salt of aluminum, copper, magnesium, calcium, zinc oleate, salt of manganese, iron, copper, magnesium, etc., zinc of palmitic acid, salt of copper, magnesium, calcium, etc., zinc of linoleic acid, calcium, etc. And salts of higher fatty acids such as salts, zinc of ricinoleic acid, salts of calcium, and the like.

  The amount of these external additives added is about 0.01 to 10% by mass with respect to the toner.

  The intermediate transfer belt 6 is a semiconductive endless belt, is wound around a plurality of backup rollers 61, 62, etc., and is driven by a motor (not shown) to rotate clockwise.

  Opposite to the photosensitive drums 1Y, 1M, 1C, and 1K, primary transfer rollers 7Y, 7M, 7C, and 7K for the respective colors are provided via the intermediate transfer belt 6.

  The primary transfer rollers 7Y, 7M, 7C, and 7K are formed on the photosensitive drums 1Y, 1M, 1C, and 1K by applying a DC voltage having a polarity opposite to that of the toner and forming a transfer electric field in the transfer area. The toner images of the respective colors are primarily transferred onto the intermediate transfer belt 6.

  A secondary transfer roller 9 is provided through the intermediate transfer belt 6 so as to face the backup roller 62 for secondary transfer.

  A DC voltage having a polarity opposite to that of the toner is applied to the secondary transfer roller 9 to form a transfer electric field in the transfer area, so that the superimposed toner image carried on the intermediate transfer belt 6 is transferred onto the transfer material (paper) P. Secondary transfer to the surface of

  The transfer material P is fed from the sheet feeding cassette 21 by the sheet feeding means 20, and is conveyed to the secondary transfer position via a plurality of intermediate rollers 23, 24, 25, and 26 and a registration roller 27, and the color image is collectively transferred. Is done.

  When the size of the transfer material P is changed, the length (paper width) in the direction orthogonal to the transport direction is configured to change based on the center of the intermediate transfer belt 6.

  The transfer material P onto which the color image has been transferred is fixed by the fixing unit 30, is sandwiched by the paper discharge roller 28, and is placed on the paper discharge tray 29.

  A cleaning device 8 for removing toner remaining on the intermediate transfer belt 6 is provided on the downstream side of the secondary transfer position in the rotational direction of the intermediate transfer belt 6. The details of the cleaning device 8 will be described later.

  Here, materials of the intermediate transfer belt 6, the primary transfer roller 7, the secondary transfer roller 9 and the like in the present embodiment will be described.

The intermediate transfer belt 6 is an endless belt having a volume resistance of 10 ⁶ to 10 ¹² Ω · cm. For example, polycarbonate (PC), polyimide (PI), polyamideimide (PAI), polyvinylidene fluoride (PVDF), and etrafluoro A resin material such as ethylene-ethylene copolymer (ETFE) or a rubber material such as EPDM, NBR, CR, polyurethane, etc., in which a conductive filler such as carbon is dispersed or an ionic conductive material is contained. The thickness used is preferably about 50 to 200 μm in the case of a resin material and about 300 to 700 μm in the case of a rubber material.

The primary transfer rollers 7Y, 7M, 7C, and 7K, for example, disperse a conductive filler such as carbon in a rubber material such as polyurethane, EPDM, or silicone on the peripheral surface of a conductive core such as stainless steel having an outer diameter of 8 mm. In addition, an ionic conductive material is contained, and the volume resistance is about 10 ⁵ to 10 ⁹ Ω · cm in a solid state or a foamed sponge state, the thickness is 5 mm, and the rubber hardness is about 20 to 70 ° (Asker hardness C) is formed by coating a semiconductive elastic rubber.

The secondary transfer roller 9 is formed by dispersing a conductive filler such as carbon in a rubber material such as polyurethane, EPDM, or silicone on a peripheral surface of a conductive metal core such as stainless steel having an outer diameter of 8 mm, for example. Semi-conducting material that contains a material and has a volume resistance of about 10 ⁵ to 10 ⁹ Ω · cm in a solid state or foamed sponge state, a thickness of 5 mm, and a rubber hardness of about 20 to 70 ° (Asker-C) It is formed by covering an elastic rubber.

  Unlike the primary transfer rollers 7Y, 7M, 7C, and 7K, the secondary transfer roller 9 may come in contact with toner and may cover the surface with a good releasability such as semiconductive fluorine resin or urethane resin. The secondary transfer backup roller 62 disperses a conductive filler such as carbon in a rubber or resin material such as polyurethane, EPDM, or silicone on the peripheral surface of a conductive core metal such as stainless steel or an ionic conductive material. It is formed by coating a semiconductive material that is contained or having a thickness of about 0.05 to 0.5 mm.

  Next, the image forming process will be described.

  When the image recording is started, a drive motor (not shown) of the photosensitive drum 1Y is started, and the photosensitive drum 1Y of the yellow (Y) image forming unit 10Y is rotated counterclockwise as indicated by an arrow in FIG. Application of a potential to the photosensitive drum 1Y is started by the charging action of the charging unit 2Y.

  After the photosensitive drum 1Y is applied with an electric potential, image writing is started by the exposure means 3Y using an electrical signal corresponding to the first color signal, that is, yellow (Y) image data, and a document is formed on the surface of the photosensitive drum 1Y. An electrostatic latent image corresponding to the yellow (Y) image of the image is formed. The electrostatic latent image is reversely developed in a contact or non-contact state by the developing roller 4Y1, and a yellow (Y) toner image is formed on the photosensitive drum 1Y according to the rotation of the photosensitive drum 1Y.

  The yellow (Y) toner image thus formed on the photosensitive drum 1Y is transferred onto the intermediate transfer belt 6 by the primary transfer roller 7Y.

  Subsequently, the yellow (Y) toner image on the intermediate transfer belt 6 is synchronized, and magenta (M), cyan (C), and black (K) toner images are sequentially superimposed to form a color. A toner image is obtained.

  The transfer residual toner remaining on the peripheral surfaces of the photosensitive drums 1Y, 1M, 1C, and 1K after the transfer is removed by the cleaning devices 5Y, 5M, 5C, and 5K.

  In synchronization with the formation of the color toner image on the intermediate transfer belt 6, the transfer material P separated and conveyed one by one from the paper feed cassette 21 is fed with paper feed rollers 22, 23, 24, 25, 26 and a registration roller 27. The color toner images on the intermediate transfer belt 6 are collectively transferred onto the transfer material P by the secondary transfer roller 9.

  The transfer material P onto which the color toner image has been transferred is neutralized by a separating means (not shown), conveyed to the fixing device 30, fixed and fixed by heat and pressure, and then discharged by a paper discharge roller 28. It is discharged to the paper tray 29.

  On the other hand, residual toner remaining on the peripheral surface of the intermediate transfer belt 6 after the transfer is removed by the cleaning device 8.

  When the recording material P that has been subjected to the fixing process is reversed and discharged, the recording material P passes through the conveyance path on the right side of the branch plate 28A disposed between the belt fixing device 30 and the discharge roller 28, and the lower side. After being transported to the first transport path <1>, it is transported in the reverse direction, passes through the second transport path <2> on the left side of the branch plate 28A, and is discharged out of the apparatus by the paper discharge roller 28.

  When copying on both sides of the recording material P, after fixing the image formed on the first surface of the recording material P, the recording material P is moved to the first conveyance path <1>, and further to the fourth lower side of the branch plate 28B. After being introduced into the transport path <4>, it is transported in the reverse direction, passed through the transport path on the right side of the branch plate 28B, transported to the third transport path <3>, then detoured upward and transported by the paper feed roller . The recording material P is formed with images of the respective colors on both sides by the image forming means 10Y, 10M, 10C, and 10K, heated and fixed by the belt fixing device 30, and discharged to the outside by the paper discharge roller 28.

  Next, the detailed structure regarding the cleaning apparatus 8 concerning this invention is described.

  FIG. 2 is a cross-sectional view of a main part of the cleaning device.

  Reference numeral 81 denotes a casing, to which each member constituting the cleaning device 8 is mounted.

  A cleaning blade 82 is made of an elastic body such as polyurethane rubber, and is fixed to the blade holder 83 with an adhesive or the like. The blade holder 83 is rotatably attached to a support shaft 81A provided in the casing 81, and is urged counterclockwise by a spring (not shown). Accordingly, the edge 82A of the cleaning blade 82 is in pressure contact with the intermediate transfer belt 6 supported by the backup roller 61 in a state in which the edge 82A faces in the direction opposite to the rotation direction of the intermediate transfer belt 6 (counter direction).

  A cleaning roller 84 has a brush on the surface, and is pressed against the intermediate transfer belt 6 while being rotated counterclockwise by a rotating means (not shown).

  Reference numeral 85 denotes a flicker made of a resin plate, a stainless plate or the like, one end of which is fixed to the casing 81 and the other end is in contact with the cleaning roller 84.

  A conveyance screw 86 is provided in the toner conveyance path 81b located at the bottom of the casing 81 and conveys toner by means of a helical screw blade that is rotated by a driving source (not shown).

  Reference numeral 87 denotes a seal plate made of PET or the like, one end of which is fixed to the casing 81 and the other end abuts against the intermediate transfer belt 6 to prevent the transfer residual toner from leaking.

  In the cleaning device 8 configured as described above, the transfer residual toner remaining on the intermediate transfer belt 6 after the toner image is transferred to the recording material P by the transfer roller 9 is first applied to the cleaning roller 84 by the rotation of the intermediate transfer belt 6. Touch. Since a bias voltage opposite to the polarity of the transfer residual toner is applied to the cleaning roller 84 by a low current power source (not shown), the residual toner on the intermediate transfer belt 6 is electrostatically adsorbed to the cleaning roller 84. The transfer residual toner adsorbed by the cleaning roller 84 is scraped off by the flicker 85 and falls to the toner conveyance path 81 b below the casing 81.

  The transfer residual toner remaining on the intermediate transfer belt 6 without being removed by the cleaning roller 84 is scraped and dropped by the cleaning blade 82 and adheres to the cleaning roller 84, but is similarly scraped by the flicker 85 to remove the toner. It falls to the conveyance path 81b.

  In this way, the transfer residual toner dropped to the lower portion of the casing 81 is conveyed to the outside of the cleaning device 8 (perpendicular to the paper surface) by the rotation of the conveying screw 86, and further conveyed to the toner collection box by another conveying screw (not shown). The toner is collected as waste toner.

  Here, when the image forming apparatus is placed in a high humidity environment, transfer residual toner adheres to the conveying screw 86 due to in-machine condensation or toner absorption. As the amount of transfer residual toner gradually increases, the toner conveyance path 81b is clogged, and the transfer residual toner is not conveyed outside the cleaning device 8 but accumulated in the toner conveyance path 81b and transferred to the cleaning device 8. If the remaining toner becomes full, the cleaning action is lost. In some cases, the cleaning device may be damaged.

  Therefore, in the present invention, a toner scraping member 91 for scraping off the transfer residual toner from the conveying screw 86 is provided. One embodiment and an assembling method of the toner scraping member 91 are added to FIG. Will be described with reference to FIG. 3 is an exploded perspective view before the toner scraping member 91 is assembled, FIG. 4 is a perspective view after the toner scraping member 91 is assembled, and FIG. 5 is a diagram showing the relationship between the toner scraping member 91 and the conveying screw 86. It is.

  As clearly shown in FIG. 3, the toner scraping member 91 is formed of a thin plate of polyethylene (ultra high molecular weight polyethylene), and includes a first contact portion 91a, a support portion 91b, and a second contact portion 91c. They are connected in this order to form a U shape. The first contact portion 91a and the second contact portion 91c have the same shape and the same dimensions. PET or the like may be used as the material, but polyethylene has better sliding performance with the conveying screw 86 and less frictional resistance, so that durability performance is improved. Further, the plate thickness is preferably in the range of 0.1 mm to 0.5 mm, and particularly preferably 0.3 mm.

  Reference numeral 92 denotes a holding member that holds the toner scraping member 91, and has a plurality of long holes 92a into which the first contact portion 91a and the second contact portion 91c can be inserted.

  At the time of assembly, a large number of toner scraping members 91 are prepared, the holding member 92 is arranged on the conveying screw 86 side from the toner scraping member 91, and the toner is scraped off from the back side of the holding member 92 with respect to the conveying screw 86. The first contact portion 91 a and the second contact portion 91 c of the member 91 are respectively inserted into the long holes 92 a, and the support portion 91 b of the toner scraping member 91 is attached to the back surface of the holding member 92.

  The total number of the first contact portions 91a and the second contact portions 91c is substantially equal to a value obtained by dividing the length of the conveying screw 86 by the screw pitch. In a normal image forming apparatus, the total number of first contact portions 91a and second contact portions 91c is about 40 sheets, and the number of toner scraping members 91 is about 20.

  In some cases, the toner scraping member 91 may include only the first contact portion 91a and the support portion 91b and may be formed in an L shape.

  As described above, after the toner scraping member 91 and the holding member 92 are integrated, the back side of the support portion 91b with respect to the transport screw 86 is brought into contact with the side wall 81b1 that forms the toner transport path 81b. Subsequently, a small screw 93 is passed through a hole (not shown) provided in the side wall 81b1, a square hole 91d formed in the support portion 91b of the toner scraping member 91, and a hole 92b formed in the holding member 92. A nut 94 is screwed from the tip of 93 to fix the toner scraping member 91 and the holding member 92 to the side wall 81b1 of the toner conveyance path 81b.

  At this time, the plate surfaces (surface portions) of the first contact portion 91 a and the second contact portion 91 c of the toner scraping member 91 are arranged substantially orthogonal to the axial direction of the conveying screw 86.

  Further, the plate surfaces (surface portions) of the first contact portion 91a and the second contact portion 91c of the toner scraping member 91 are disposed substantially parallel to the vertical direction.

  Further, it is desirable to provide two or more sets of machine screws 93 and nuts 94.

  Furthermore, since the number of the small screws 93 and nuts 94 is much smaller than the number of the toner scraping members 91, it is not necessary to provide the square holes 91d in all the toner scraping members 91. For common use, all toner scraping members 91 are provided with square holes 91d.

  As shown in FIG. 4, the toner scraping member 91 is assembled, and the first contact portion 91a and the second contact portion 91c are moved from the axial direction of the transport screw 86 to the screw blades 86a of the transport screw 86. The conveying screw 86 is disposed so as to abut.

  Note that a step is provided in the first contact portion 91 a and the second contact portion 91 c of the toner scraping member 91, and the first contact portion 91 a and the second contact portion 91 c are formed in the long holes of the holding member 92. You may make it the structure which stops in the middle when it penetrates into 92a. In this case, the support portion 91 b of the toner scraping member 91 does not contact the back surface of the holding member 92.

  After the assembly as described above, the mutual positions of the screw blade 86a and the toner scraping member 91 change as shown in FIG.

  In FIG. 5, even if the first contact portion 91a (same as the second contact portion 91c) of the toner scraping member 91 and the screw blade 86a of the conveying screw 86 are separated as shown in FIG. Since the screw blade 86a moves to the right in the drawing by the rotation of the conveying screw 86, the first contact portion 91a contacts the screw blade 86a from the axial direction of the conveying screw 86 as shown in B. Thereafter, the screw blade 86a further moves to the right in the drawing. However, since the first contact portion 91a is a thin plate and has elasticity, the first contact portion 91a is spiral as shown in B to C. The transfer residual toner adhering to the screw blade 86a is scraped off. When the screw blade 86a further moves to the right in the drawing, the first contact portion 91a is greatly deformed as shown in D, and the first contact portion 91a rides on the outer periphery of the screw blade 86a as shown in E, Return to state A. In this manner, the first contact portion 91a and the second contact portion 91c swing, and the operations A to E are repeated.

  Even during such operation, the transfer residual toner falls from above the cleaning device 8, but the portion of the toner scraping member 91 that faces in the vertical direction is only the narrow plate thickness portion. The dropped transfer residual toner is very difficult to adhere to the toner scraping member 91.

  By the way, the toner scraping member described above is for scraping off the transfer residual toner adhering to the transport screw for transporting the transfer residual toner removed from the intermediate transfer belt. However, the toner scraping member of the present invention may be a member for scraping off the transfer residual toner attached to the transport screw for transporting the transfer residual toner removed from the photosensitive drum. At that time, the transfer residual toner may be collected as waste toner, or may be transported to the developing device as recycled toner and reused.

  Further, the toner scraping member of the present invention is not limited to the purpose of scraping off the transfer residual toner, but a conveying screw provided in the toner supplying device for supplying new toner to the developing device, In order to scrape off the toner adhering to the conveying screw provided in FIG.

1 is a cross-sectional configuration diagram of an image forming apparatus that forms a color image. It is principal part sectional drawing of a cleaning apparatus. FIG. 6 is an exploded perspective view before assembling a toner scraping member. It is a perspective view after assembling the toner scraping member. FIG. 6 is a diagram illustrating a relationship between a toner scraping member and a conveying screw.

Explanation of symbols

6 Intermediate transfer belt 8 Cleaning device 81b Toner conveyance path 81b1 Side wall 82 Cleaning blade 86 Conveying screw 91 Toner scraping member 91a First contact portion 91b Support portion 91c Second contact portion 92 Holding member 92a Long hole 93 Machine screw 94 nut

Claims (14)

A transport screw for transporting toner by rotation of a screw blade;
A toner scraping member having an abutting portion that abuts and swings against the screw blade from the axial direction of the conveying screw;
A holding member for holding the toner scraping member,
The image forming apparatus according to claim 1, wherein the contact portion is inserted into a long hole provided in the holding member from a back side with respect to the conveying screw. The toner scraping member has a support portion for supporting the contact portion,
2. The image forming apparatus according to claim 1, wherein after the contact portion penetrates into the elongated hole, the support portion is contacted to a back side of the holding member with respect to the conveying screw. The image forming apparatus according to claim 1, wherein the toner scraping member is formed of a thin plate, and a surface portion of the contact portion is disposed substantially orthogonal to an axial direction of the conveying screw. apparatus. The image forming apparatus according to claim 1, wherein a surface portion of the contact portion of the toner scraping member is disposed substantially parallel to a vertical direction. The toner scraping member is formed in a U-shape having a first abutting portion, a second abutting portion, and a support portion connecting the abutting portions. The image forming apparatus according to claim 1. 6. A plurality of long holes are provided in the holding member in the axial direction of the conveying screw, and abutting portions of the plurality of toner scraping members are inserted into the plurality of long holes. The image forming apparatus according to any one of the above. The image forming apparatus according to claim 1, wherein the toner scraping member is made of polyethylene. The toner is transfer residual toner collected by a cleaning unit, and the transport screw, the toner scraping member, and the holding member are disposed in a toner transport path for transporting the transfer residual toner. The image forming apparatus according to any one of 1 to 7. The image forming apparatus according to claim 8, wherein a holding member that holds the toner scraping member is fixed to a side wall that forms the toner conveyance path. A method for assembling a toner scraping member that contacts a conveying screw that conveys toner by rotation of a screw blade,
A contact portion provided on the toner scraping member to be in contact with the screw blade from the axial direction of the transport screw is provided in a long hole provided in a holding member for holding the toner scraping member. A method for assembling a toner scraping member, comprising the step of further penetrating. The toner scraping-off method according to claim 10, further comprising a step of abutting a support portion provided on the toner scraping member to support the abutting portion on a back side of the holding member with respect to the conveying screw. Assembling method of members. Disposing a holding member holding the toner scraping member on a toner conveyance path for conveying toner;
Fixing the holding member to a side wall forming the toner conveyance path;
The method of assembling the toner scraping member according to claim 10 or 11, wherein the toner scraping member is provided. The toner scraping member is formed of a thin plate, and has a step of arranging a surface portion of the abutting portion substantially orthogonal to the axial direction of the conveying screw. A method for assembling the toner scraping member. The method of assembling the toner scraping member according to claim 10, further comprising a step of arranging a surface portion of the contact portion of the toner scraping member substantially parallel to a vertical direction.

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