JP6217622B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus including a housing that houses an image forming unit.

  In the image forming apparatus, the housing in which the image forming unit is accommodated has a structure in which pillars are erected at the four corners of a rectangular bottom plate, and front and rear and left and right side plates are arranged between the pillars to form a rectangular parallelepiped shape. Things are common. In such a case, each column and each side plate are rigidly fixed to the bottom plate so that rigidity is obtained. In addition, with the demand for weight reduction of image forming apparatuses, weight reduction of housings has been promoted.

  One of the measures for reducing the weight of the housing is to reduce the weight of the bottom plate. However, when the weight of the bottom plate is reduced, there is a concern about a decrease in rigidity of the entire housing.

  In Patent Document 1, a pair of support columns having a U-shaped cross section are erected on the bottom plate so that the U-shaped openings face each other, and the front plate is supported by both columns, thereby improving the rigidity of the front plate. An image forming apparatus configured to enhance is disclosed. Patent Document 2 discloses a quadrangular columnar columnar structure by fastening a bent portion obtained by bending a side end portion of a front side plate or a rear side plate into a L-shaped cross section and a support column having a L-shaped cross section. An image forming apparatus having a body is disclosed.

JP 2009-265540 A JP 2010-210897 A

  However, in the image forming apparatus described in Patent Document 1, the front plate is supported by the pair of support columns above the opening from which the paper feed cassette is attached and detached. In the image forming apparatus described in Patent Document 2, the bent portion formed on the front side plate or the rear side plate is formed only above the opening from which the paper feed cassette is attached and detached. Therefore, in the image forming apparatuses described in Patent Document 1 and Patent Document 2, sufficient rigidity is ensured when the weight of the conveying device, the fixing device, or the like is applied to the support column or an impact is applied to the support column from below. There is a possibility that it cannot be done.

  SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide an image forming apparatus including a casing that has high rigidity and can be reduced in weight.

  In order to solve the above problems, an image forming apparatus according to the present invention is an image forming apparatus including a transport frame that forms a transport path of a sheet from a sheet storage unit toward the image forming unit, and the transport frame includes two support columns. A columnar protrusion extending in the vertical direction is formed on at least one end of the support frame side end of the transport frame, and the columnar protrusion is integrated with the column. It is characterized by.

  By adopting such a configuration, the connection strength between the conveyance frame and the support can be increased, so that the conveyance frame can also be used as a side plate arranged on the side surface of the image forming apparatus, and by reducing the number of parts Cost reduction is possible.

  In the image forming apparatus of the present invention, the support column has a substantially U-shaped cross section having a hollow portion, and the columnar protrusion has a rectangular pipe shape with a rectangular cross section. The columnar protrusion may be integrated with the column by entering the hollow portion of the column and fastening to the column.

  By adopting such a configuration, the columnar protrusion and the support column partially form a double structure, so that the rigidity of the support column can be increased.

  In the image forming apparatus of the present invention, a support member that supports the weight of the support column is provided at the lower end of the support column, and the lower end of the columnar protrusion is in contact with the support member. It is also good.

  By adopting such a configuration, the load applied to the conveyance frame and the column and the impact applied to the conveyance frame and the column from below are dispersed and absorbed in the conveyance frame and the column. Can be prevented.

  The image forming apparatus according to the present invention includes an exterior cover that is rotatably provided outside the transport frame, and a rotation fulcrum portion of the exterior cover is formed integrally with the transport frame. Also good.

  By adopting such a configuration, the positioning accuracy between the transport frame and the exterior cover can be increased, so that the sheet transport accuracy can be improved and a high-quality image can be formed. In addition, the number of parts can be reduced and the cost can be reduced.

  In the image forming apparatus of the present invention, the support column may be formed of a metal material, and the transport frame may be formed of a resin material.

  By adopting such a configuration, the conveyance frame can be easily formed in a complicated structure and can be formed at low cost while increasing the rigidity of the support column.

  In the image forming apparatus of the present invention, the image forming apparatus includes a front side plate and a rear side plate respectively disposed before and after the image forming unit, and the support column is at least one end of the left and right end portions of the front side plate and the rear side plate. The transport frame may be supported by the support column and fastened to the front side plate and the rear side plate.

  By adopting such a configuration, the rigidity of the transport frame can be further increased.

  According to the present invention, the bottom plate of the housing can be deleted, and the conveyance frame can also be used as the side plate disposed on the side surface of the image forming apparatus, so that the image forming apparatus can be reduced in weight.

1 is a schematic diagram illustrating an outline of a color printer according to an embodiment of the present invention. 1 is a perspective view showing an overall structure of a housing in a color printer according to an embodiment of the present invention. In the color printer which concerns on one Embodiment of this invention, it is a cross-sectional perspective view which shows the structure of the support | pillar of a housing | casing. FIG. 4 is a perspective view illustrating a conveyance frame of a housing in the color printer according to the embodiment of the invention. In the color printer which concerns on one Embodiment of this invention, it is a cross-sectional perspective view which shows the lower end part of the support | pillar of a housing | casing. In the color printer which concerns on one Embodiment of this invention, it is a cross-sectional perspective view which shows the support | pillar and conveyance frame of a housing | casing.

  Hereinafter, an image forming apparatus according to an embodiment of the present disclosure will be described with reference to the drawings.

  First, the overall main configuration of the color printer 1 (image forming apparatus) will be described with reference to FIG. FIG. 1 is a schematic diagram showing an outline of a printer according to an embodiment of the present invention. Hereinafter, the front side in FIG. 1 is the front side (front side) of the color printer 1, and the left and right directions will be described with reference to the direction viewed from the front of the printer 1.

  The color printer 1 includes a housing 3 having a substantially rectangular parallelepiped hollow portion 2. A paper discharge tray 5 is provided on the upper surface of the housing 3. A sheet feeding cassette 6 (sheet storing section) for storing sheets is provided below the hollow section 2, and a process unit 7 (image forming section) for forming an image on the sheet is disposed above the sheet feeding cassette 6. ) Is provided. The process unit 7 is arranged in parallel along an exposure apparatus 8 constituted by a laser scanning unit (LSU), an intermediate transfer belt 9 installed between rollers, and a lower part of the intermediate transfer belt 9. The image forming apparatus 10 and the transfer roller 12 which forms the secondary transfer part 11 between the intermediate transfer belts 9 are included. The image forming device 10 is rotatably provided with a photosensitive drum 13 that is an image carrier. Around the photosensitive drum 13, a charging device 14, a developing device 15, a transfer roller 16, and a cleaning device are provided. The device 17 and the static eliminating device 18 are sequentially arranged along the rotation direction of the photosensitive drum 13.

  Further, on the right side of the process unit 7, a conveying device 20 that conveys a sheet fed from the sheet feeding cassette 6 to the secondary transfer unit 11 is accommodated, and four color toners are placed above the process unit 7. The accommodated toner container 21 is accommodated.

  Further, in the hollow portion 2, a fixing device 22 is accommodated above the secondary transfer portion 10, and a paper discharge device 23 facing the paper discharge tray 5 is accommodated above the fixing device 22. A sheet conveyance path 24 is provided along the right side surface of the hollow portion 2 from the conveyance device 20 to the paper discharge device 23 through the secondary transfer unit 11 and the fixing device 22.

  An image forming operation of the printer 1 having such a configuration will be described. In each image forming device 10, after the surface of the photosensitive drum 13 is charged by the charging device 14, an electrostatic latent image is formed on the surface of the photosensitive drum 13 by the laser light (see arrow P) from the exposure device 8. The The electrostatic latent image is developed into a corresponding color toner image by the developing device 15 using the toner supplied from the toner container 21. This toner image is primarily transferred onto the surface of the intermediate transfer belt 9 by the transfer roller 16. Each image forming apparatus 10 sequentially repeats the above operation, whereby a full-color toner image is formed on the intermediate transfer belt 9. The toner and the charge remaining on the photosensitive drum 13 are removed by the cleaning device 17 and the charge removal device 18.

  On the other hand, the sheet fed from the sheet feeding cassette 6 is conveyed to the secondary transfer unit 11 by the conveying device 20 in synchronism with the image forming operation described above, and in the secondary transfer unit 11 on the intermediate transfer belt 9. The full-color toner image is secondarily transferred to the sheet. The sheet on which the toner image is secondarily transferred is conveyed downstream in the conveyance path 24 and enters the fixing device 22, and the toner image is fixed on the sheet in the fixing device 22. The sheet on which the toner image is fixed is discharged from the paper discharge device 23 onto the paper discharge tray 5.

  Next, the housing 3 will be described with reference to FIGS. 2 is a perspective view of the entire housing as viewed from the right front, FIG. 3 is a cross-sectional perspective view illustrating the structure of the support column of the housing, FIG. 4 is a cross-sectional perspective view illustrating the transport frame of the housing, and FIG. FIG. 6 is a cross-sectional perspective view showing the lower end portion of the support post, and FIG.

  As shown in FIG. 2, the housing 3 includes support columns 31, 32, 33, and 34 disposed at four corners (front left corner, front right corner, rear left corner, rear right corner) of the hollow portion 2, and the hollow portion 2. A rectangular partition plate 35 that divides the lower space 2a and the upper space 2b, a front plate 36 disposed on the front surface of the hollow portion 2, a rear plate 37 disposed on the rear surface of the hollow portion 2, and a hollow portion 2 has a left side plate 38 disposed on the left surface, and a transport frame 39 disposed on the right side of the hollow portion 2. The periphery of the front side plate 36, the rear side plate 37, and the left side plate 38 is covered with an exterior cover (not shown). An exterior cover 40 (see FIG. 1) covering the outer side of the transport frame 39 is rotatably supported.

  The four struts 31, 32, 33, 34 are formed of a metal material, and the front right strut 32 and the rear right strut 34 are channel-like members having a U-shaped cross section that is open on the left side. It is. As shown in FIG. 3, the front left column 32 includes a front plate portion 32a, a right plate portion 32b bent at a right angle rearward from the right side of the front plate portion 32a, and a right angle from the rear side of the right plate portion 32b to the left. And a rear plate portion 32c bent. The front plate portion 32a and the right plate portion 32b have substantially the same width, and the rear plate portion 32c has a width of about 1/3 of the width of the front plate portion 32a and the right plate portion 32b. Further, the front plate portion 32a is formed with a left plate portion 32d bent at a right angle rearward from the left side and a folded portion 32e folded at a right angle from the rear side of the left plate portion 32d to the right. The left plate portion 32d has a width of about 1/3 of the width of the front plate 32a, and the folded portion 32e has a narrower width than the left plate portion 32d. With such a configuration, an opening 32f opened on the left side is formed between the rear plate portion 32c and the folded portion 32e, and the hollow portion is surrounded by the front plate portion 32a, the right plate portion 32b, and the rear plate portion 32c. 32g is formed. The rear right column 34 also has the same structure as the front right column 32.

  The front left column 31 and the rear left column 33 are formed of an angle material member having a substantially L-shaped cross section, a channel material member having a U-shaped cross section, a square pipe-shaped member, or the like. The

  The front right column 32, the rear left column 33, and the rear right column 34 are formed longer than the front left column 31 and extend above the hollow portion 2.

  As shown in FIG. 2, the partition plate 35 includes a horizontally long rectangular base portion 41 and a step portion (not shown) that rises stepwise from the right edge of the base portion 41. A plurality of reinforcing recesses 42 are formed in the base portion 41 by pressing, along the diagonal or outer periphery. The partition plate 35 is made of, for example, a sheet metal material.

  The partition plate 35 is disposed with a space between the right side surface of the hollow portion 2, and the front left corner and the rear left corner are supported at substantially the center in the vertical direction of the front left column 31 and the rear left column 33, respectively. Has been.

  The front plate 36 has a horizontally long rectangular shape, and a substantially rectangular opening 45 is formed at the center. A rectangular front mounting plate 47 is fastened with screws at the right end of the upper edge of the front plate 36. The front side plate 36 and the front mounting plate 47 are made of, for example, a sheet metal material. The front side plate 36 is disposed on the front side surface of the upper space 2b and fastened with screws to the front left column 31 and the front right column 32, and the front mounting plate 47 is fastened to the front right column 32 with screws. Yes.

  The rear side plate 37 has a rectangular shape, and a rectangular rear mounting plate 48 corresponding to the front mounting plate 47 of the front side plate 36 is fastened with screws at the right end of the upper edge. The rear side plate 37 and the rear mounting plate 48 are made of, for example, a sheet metal material. The rear plate 37 is disposed over the entire rear side surface of the upper and lower spaces 2b and 2a, and is fastened to the rear left column 33 and the rear right column 34 with screws. The rear mounting plate 48 is screwed to the rear right column 34. It is concluded with.

  The left side plate 38 has a rectangular shape, and a lower edge portion 38a bent rightward is formed at the lower end. The left side plate 38 is disposed over the entire left side of the upper and lower spaces 2b and 2a and fastened to the front left column 31 and the rear left column 33 with screws.

  The conveyance frame 39 is a member that forms a conveyance path 23 from the sheet cassette 6 to the secondary transfer unit 9 for the sheet fed. As shown in FIGS. 2 and 4, the transport frame 39 has an L-shaped shape when viewed from the front. The transport frame 39 extends substantially horizontally and extends downward from the right edge of the upper frame portion 51. A bent right frame portion 52, and is formed of a resin material. The upper frame portion 51 has lattice-like ribs formed on the upper surface. An opening 52 a through which a sheet fed from the sheet feeding cassette 6 passes is formed in the lower portion of the right frame portion 52. Further, at the lower portion of the right surface of the right frame portion 52, the rotation fulcrum portions 54 of the exterior cover 40 are provided to protrude in the right direction on both sides of the opening 52a. Each rotation fulcrum portion 54 is formed with a shaft hole 54a extending in the front-rear direction on the same axis.

  Furthermore, a columnar protrusion 55 extending in the height direction of the right frame portion 52 is formed on the right surface of the right frame portion 52 on the front side and the rear side of the front and rear rotation fulcrum portions 54. As shown in FIG. 3, the columnar protrusion 55 is formed in a square pipe shape having a rectangular parallelepiped cross section that is long in the left-right direction. Further, as shown in FIG. 5, at the lower end of the columnar protrusion 55, a trapezoidal notch 58 is formed at the lower end of the pair of opposed long side plates, and at the lower end of the pair of opposed short side plates. A rectangular cutout 59 is formed. Further, as shown in FIGS. 3, 4, and 5, an outer frame portion 56 extending in the right direction is provided on the right surface of the right frame portion 52 on the front side of the front columnar protrusion 55. It is formed along the height direction. The outer frame portion 56 is formed with a support portion for an exterior cover that covers the periphery of the front side plate 36.

  Further, as shown in FIG. 2, the housing 3 has a channel-like shape between the lower ends of the front left column 31 and the front right column 32 and between the lower left columns of the rear left column 33 and the rear right column 34. A front stay 61 (support member) and a rear stay 62 are installed. The front left column 31 and the front right column 32, the rear left column 33 and the rear right column 34 are supported at their lower ends by rubber feet 64 via front stays 61 and rear stays 62, respectively. As shown in FIG. 5, a shallow recess 61 a is formed above the rubber foot 64 at the right end of the bottom of the front stay 61.

  Further, an upper plate 71 is installed between the front mounting plate 47 and the rear mounting plate 48. A front plate 72 is installed between the left side plate 38 and the front mounting plate 47 along the upper edge of the front side plate 36, and along the upper edge of the rear side plate 37, A rear plate 73 is installed between the mounting plate 48. Further, an upper stay 75 is installed between the rear left column 33 and the rear right column 34.

  In the housing 3 having the above-described configuration, the paper feed cassette 6 is accommodated in the lower space 2 a below the partition plate 35, and the process unit 7 is accommodated in the upper space 2 b above the base portion 41 of the partition plate 35. The partition plate 35 prevents the developer scattered from the process unit 7 from falling on the sheet accommodated in the paper feed cassette 6. Further, the transport device 20 is disposed between the step portion of the partition plate 35 and the upper frame portion 51 of the transport frame 39, and the fixing device 22 is disposed in the space between the front and rear mounting plates 47 and 48 and the upper plate 71. And a paper discharge device 23 are arranged. An image reading unit (not shown) can be disposed above the upper plate 71 and the upper stay 75.

  Further, the bottom surface of the housing 3 has a rectangular opening 77 surrounded by the front stay 61, the lower edge of the rear side plate 37, the lower edge portion 38 a of the left side plate 38, and the lower edge of the transport frame 39. It is formed, and the bottom plate which has existed conventionally is not provided.

  In the transport frame 39, the upper frame portion 51 is disposed below the stepped portion of the partition plate 35, and the right frame portion 52 is disposed slightly inside the right side surface of the lower space 2a. The front and rear columnar protrusions 55 enter the hollow portions of the columns 32 and 34 from the left openings of the front right column 32 and the rear right column 34, respectively. With reference to FIG. 3, the front columnar protrusion 55 will be described. The front columnar protrusion 55 is formed from the opening 32 f between the rear plate portion 32 c and the folded portion 32 e of the front right column 32, and the front plate portion 32 a. It enters the space 32g surrounded by the right plate portion 32b and the rear plate portion 32c. The columnar protrusion 55 enters 32g until the right side surface abuts the inner surface of the right plate portion 32b of the front right column 32 (see FIG. 6), and the pin formed on the right side surface of the columnar projection 55 is the front right column. 32 is inserted into a positioning hole formed in the right plate portion 32b. Further, the rear side surface and the front side surface of the columnar protrusion 55 are in contact with the inner surface of the rear plate portion 32c of the front right support column 32 and the outer surface of the folded portion 32e, respectively. Further, the outer frame portion 56 of the transport frame 39 overlaps the outer surface of the front plate portion 32 a of the front right column 32, and the left plate portion 32 d of the front right column is sandwiched between the outer frame portion 56 and the columnar protrusion 55. It is.

  Further, as shown in FIG. 5, the lower end of the front right column 32 is in contact with the periphery of the recess 61 a of the front stay 61, and the lower end of the columnar protrusion 55 of the transport frame 39 is the recess 61 a of the front stay 61. Abut. Specifically, in the columnar protrusion 55, the four corners outside the notches 58 and 59 are in contact with the recess 61 a of the front stay 61. As a result, the load of the front right column 32 and the columnar protrusion 55 is applied to the rubber foot 64 via the front stay 61.

  In the transport frame 39, the upper frame portion 51 is fastened to the front side plate 36 and the rear side plate 37 with screws, and the front and rear columnar protrusions 55 are inserted into the hollow portions of the front right column 32 and the rear right column 34. Each is fastened with screws.

  Furthermore, the exterior cover 40 is configured to rotate about the shaft hole 54 a of the rotation fulcrum portion 54 provided in the conveyance frame 39, and between the right frame portion 52 of the conveyance frame 39 and the exterior cover 40. In addition, a sheet conveyance path 23 is formed.

  As described above, in the case 3 of the image forming apparatus 1 of the present invention, the bottom plate and the front side plate of the lower space 2a, which are conventionally formed of a sheet metal material, do not exist. it can. However, when the bottom plate and the front side plate of the lower space 2a are not provided, there is a concern that the rigidity of the housing 3 is lowered. In particular, since the resin-made transport frame 39 is also used as the right side plate on the right side surface of the housing 3, there is a concern that the rigidity of the front right corner of the housing 3 is lowered. In the present invention, at the front right corner of the housing 3, the columnar protrusion 55 provided on the conveyance frame 39 is integrated by being inserted into the hollow portion of the front right support column 32 and partially has a double structure. By forming, the rigidity of the right front corner of the housing 3 can be increased. Furthermore, since the conveyance frame 39 is fastened to the front side plate 36 and the rear side plate 37, the rigidity of the right side surface of the housing 3 can be further increased, and the cost can be reduced by using both the conveyance frame 39 and the right side plate. .

  In addition, as the front right support 32, an angle-shaped member having an L-shaped cross-section can be used, but a channel-shaped member having a U-shaped cross-section is more This is preferable in that the number of structures becomes greater and rigidity can be obtained.

  Further, the lower end of the columnar protrusion 55 is in contact with the front stay 61 on which the lower end of the front right support column 32 is supported, and the front right support column 32 and the columnar protrusion 55 are supported on the rubber foot 64 via the front stay 61. It is configured to be. Accordingly, the weight of the housing 3 is dispersed and absorbed by the front right support column 32 and the columnar protrusion 55, and the impact applied from below is distributed and absorbed by the front right support column 32 and the columnar protrusion 55. Therefore, deformation of the front right column 32 and the transport frame 39 can be suppressed. In particular, the columnar protrusion 55 is supported by the recess 61a of the front stay 61 at four corners having high rigidity, so that the rigidity of the columnar structure can be further increased.

  Furthermore, since the rotation fulcrum portion 54 of the outer cover 40 is formed integrally with the transport frame 39, the accumulated tolerance can be reduced, and the positioning accuracy between the transport frame 39 and the outer cover 40 is improved. Therefore, the sheet can be conveyed with high accuracy, and a high-quality image can be formed. In addition, the transport frame 39 has a complicated structure including the rotation fulcrum portion 54, the columnar protrusion 55, and the like, but by forming them with a resin, these can be integrally formed, so the number of parts can be reduced, Cost can be reduced.

  In the present embodiment, the case where the columnar protrusions 55 are formed at both end portions in the front-rear direction of the transport frame 39 has been described, but the columnar protrusions 55 may be formed only at the front side end portions. In addition, the conveyance frame 39, the front right column 32, and the rear right column 34 are integrated by fastening each columnar protrusion 55 to the front right column 32 and the rear right column 34 with screws. It may be integrated by, for example.

  In order to prevent dust and the like from entering from the opening 77 on the bottom surface, a bottom plate made of a light material such as resin can be provided in the opening 77. In this case as well, the weight can be reduced as compared with the bottom plate made of sheet metal material.

  Further, in the embodiment of the present invention, the case where the configuration of the present invention is applied to the color printer 1 has been described. However, in another different embodiment, an image forming apparatus other than the color printer 1 such as a copying machine, a facsimile machine, or a multifunction machine. The configuration of the present invention may be applied to.

  Furthermore, since the above description of the embodiment of the present invention describes a preferred embodiment of the image forming apparatus according to the present invention, there may be various technically preferable limitations. The technical scope of the present invention is not limited to these embodiments unless specifically described to limit the present invention. That is, the above-described components in the embodiment of the present invention can be appropriately replaced with existing components and the like, and various variations including combinations with other existing components are possible. The description of the embodiment of the present invention described above does not limit the contents of the invention described in the claims.

1 Color printer (image forming device)
6 Paper cassette (sheet storage)
7 Process unit (image forming unit)
32 Front right column 32g Hollow portion 34 Rear right column 36 Front side plate 37 Rear side plate 39 Transport frame 40 Exterior cover 54 Rotating fulcrum 55 Columnar protrusion 61 Front stay (support member)

Claims (6)

An image forming apparatus including a transport frame that forms a transport path of a sheet from a sheet storage unit to an image forming unit,
The transport frame is disposed between two support columns, and at least one end portion of the support frame side end portion of the transport frame is formed with a columnar protrusion extending in the vertical direction. An image forming apparatus that is integrated with a support. The column has a substantially U-shaped cross-sectional shape having a hollow portion,
The columnar protrusion is in the shape of a rectangular pipe having a rectangular cross-section, and the columnar protrusion enters the hollow portion of the column and is fastened to the column to be integrated with the column. The image forming apparatus according to claim 1. A support member for supporting the weight of the support column is provided at the lower end of the support column.
The image forming apparatus according to claim 1, wherein a lower end of the columnar protrusion is in contact with the support member. An exterior cover provided rotatably on the outside of the transport frame;
The image forming apparatus according to claim 1, wherein a rotation fulcrum portion of the exterior cover is formed integrally with the transport frame.   The image forming apparatus according to claim 1, wherein the support column is formed of a metal material, and the transport frame is formed of a resin material. A front plate and a rear plate disposed on the front and rear sides of the image forming unit, respectively, and the support column is disposed on at least one end of the front plate and the rear plate in the left-right direction;
The image forming apparatus according to claim 1, wherein the transport frame is supported by the support column and fastened to the front side plate and the rear side plate.

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