JP2018142025A - Structure of image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a configuration capable of enhancing rigidity of a bottom part 400 of a structure at low cost.SOLUTION: A bottom part 400 comprises: a bottom plate part 410 formed of a plate-shape member; and a reinforcement plate 401 for reinforcing the bottom plate part 410. The bottom plate part 410 comprises: three or more installation parts 411 to which a caster is attached; and a recess part 414 for connecting the plural installation parts 411. The recess part 414 connects the plural installation parts 411 so that the respective installation parts cross in inside of a range which is surrounded by lines interconnecting the adjacent installation parts by shortest distance, and the recess part is formed by plastically deforming so as to recess a part of the plate-shape member. The reinforcement plate 401 is respectively fixed to plural areas 419A-419D of the bottom plate part 410 so as to interconnect the plural areas 419A-419D, which are divided by the recess part 414.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a structure of an image forming apparatus such as a printer, a facsimile machine, a copying machine, or a multifunction machine having a plurality of functions.

  The image forming apparatus is installed at, for example, four locations by a member such as a caster on the installation surface of the apparatus such as a floor. However, when the flatness of the installation surface is not good, the plane formed by three points is stable with respect to the installation surface even when the four installation portions are provided. At this time, if the rigidity of the structure of the image forming apparatus constituted by a frame or the like is insufficient, a portion where the image forming apparatus is not installed may sink, and the structure may be bent or twisted. Even if the configuration is such that the installation surface is installed at three locations, the load acting on each point in contact with the installation surface varies depending on the flatness of the installation surface, and the structure may be bent or Twisting can occur. If the structure is bent or twisted in this way, the accuracy of each part for image formation is lowered, which may affect the image quality.

  Thus, a configuration has been conventionally proposed in which the rigidity of the bottom portion of the structure in which the installation part for installing the device on the installation surface is formed is improved. For example, instead of a single sheet metal, the bottom is a box-shaped combination of two or more sheets (see Patent Document 1). Moreover, the structure which formed the bottom part by connecting the base reinforcement body which joined the intermediate member diagonally to the base main body is also proposed (refer patent document 2).

JP 2002-217560 A JP-A-2005-221905

  However, the configurations described in Patent Documents 1 and 2 as described above have the following problems. That is, as in the configuration of Patent Document 1, when the sheet metal is stacked in a box shape at the bottom, the weight of the structure increases and the material cost also increases.

  In addition, in the case of the configuration of Patent Document 2, it is necessary to join the intermediate member diagonally and to connect the base reinforcing body formed thereby to the base body, which increases the number of processing steps and the number of parts and material cost. Will also increase. Therefore, in any case, the manufacturing cost is inevitably increased. In the case of the configuration of Patent Document 2, it is considered that the rigidity is lower than that of the box-shaped configuration described in Patent Document 1.

  The image forming apparatus is often grounded so as to be movable by a caster or the like, and it is desired to increase not only the rigidity of the bottom of the structure but also the rigidity of the installation part to which the caster or the like is attached.

  In view of such circumstances, the present invention has been invented to realize a configuration that can increase the rigidity of the bottom portion or the installation portion of the structure at low cost.

  The present invention includes a frame in which an image forming unit is disposed, and a bottom portion that supports the frame. The bottom portion is a bottom plate portion formed of a plate-like member, and a reinforcing member that reinforces the bottom plate portion. The bottom plate portion is provided with a member to be installed on the installation surface of the apparatus, or a plurality of three or more installation portions formed integrally with the member, and the adjacent installation portions as short as possible. A concave formed by connecting the plurality of installation parts so as to intersect inside a range surrounded by a line connected by a distance, and plastically deforming the plate-like member so as to dent a part of the plate-like member. The reinforcing member is fixed to each of the plurality of regions so as to connect the plurality of regions divided by the concave shape portion of the bottom plate portion, and the area of the reinforcing member is Smaller than the area of the range In the structure of the image forming apparatus according to symptoms.

  The present invention further includes a frame in which an image forming unit is disposed, and a bottom portion that supports the frame, and the bottom portion includes a bottom plate portion formed of a plate-like member, and the bottom plate portion The plate-like member is plasticized so as to connect the plurality of installation portions at three or more places to which the member to be installed on the installation surface of the apparatus is attached and to dent a part of the plate-like member. A concave-shaped portion formed by deformation, the concave-shaped portion from a bottom surface portion and a side wall portion that continues the bottom-surface portion and a planar portion around the concave-shaped portion of the bottom plate portion. Each of the plurality of installation portions has an attachment surface portion formed by plastically deforming the plate-like member and an attachment side wall portion, and the attachment surface portion is formed in a substantially rectangular shape, The side opposite to the side where the concave portion is recessed with respect to the bottom surface portion A member to be installed and installed on the installation surface of the apparatus is attached, and the attachment side wall portion is continuous so as to surround at least two sides around the attachment surface portion while continuing the attachment surface portion and the concave shape portion. In the structure of the image forming apparatus, the image forming apparatus is formed in a flat surface.

  According to the present invention, since the plate-shaped member is plastically deformed to form the concave portion and the installation portion, the rigidity of the bottom portion or the installation portion of the structure can be increased at low cost.

1 is a schematic configuration diagram of an image forming apparatus according to a first embodiment of the present invention. 1 is a perspective view of a structure of an image forming apparatus according to a first embodiment. The perspective view of the baseplate part which concerns on 1st Embodiment. The disassembled perspective view of the bottom part concerning 1st Embodiment. The top view seen from the lower part in the state which attached the caster to the bottom part which concerns on 1st Embodiment. The perspective view which shows the state which attached the caster to the installation part which concerns on 1st Embodiment. The figure which shows the shape of the recessed part which concerns on (a) 1st Embodiment, (b) Another 1st example of the shape of a recessed part, (c) Another 2nd example of the shape of a recessed part, respectively. The top view which looked at the baseplate part which concerns on 1st Embodiment from upper direction. The figure which shows the effect of the Example which employ | adopted the structure which concerns on 1st Embodiment. The top view which looked at the bottom which concerns on the 2nd Embodiment of this invention from upper direction. The top view which looked at the baseplate part which concerns on the 3rd Embodiment of this invention from upper direction. The top view seen from the lower part in the state which attached the caster to the bottom part which concerns on 3rd Embodiment. The perspective view which looked at the installation part which concerns on 3rd Embodiment from the downward direction. The perspective view which shows the state which attached the caster to the installation part which concerns on 3rd Embodiment. The perspective view which shows the state which attached the caster to the installation part which concerns on the 4th Embodiment of this invention.

<First Embodiment>
A first embodiment of the present invention will be described with reference to FIGS. First, a schematic configuration of the image forming apparatus 100 of the present embodiment will be described with reference to FIG.

[Image forming apparatus]
The image forming apparatus 100 of the present embodiment is a full color printer that employs an electrophotographic system. Such an image forming apparatus 100 includes an image forming unit 110, a recording material transport unit 200, and a structure 300 (see FIG. 2). The image forming unit 110 has a so-called tandem configuration in which a plurality of image forming stations are arranged in the traveling direction of the intermediate transfer belt 111. In each image forming station, yellow (Y), magenta (M), cyan (C), and black (K) toner images are formed. The recording material conveyance unit 200 conveys a recording material (a sheet material such as a sheet or an OHP sheet) to which the toner image formed by the image forming unit 110 is transferred. In the structure 300, an image forming unit 120 configured by the image forming unit 110, the recording material transport unit 200, and the like is disposed inside. A detailed configuration of the structure 300 will be described later.

  Each image forming station forms a toner image as follows. Since the configuration of each image forming station is the same, the image forming station at the left end in FIG. 1 will be described with reference numerals, and the reference numerals and descriptions of the other image forming stations will be omitted.

  First, the surface of a photosensitive drum (photosensitive member) 112 as an image carrier is charged by a charging device (not shown), and the charged surface of the photosensitive drum 112 is exposed by a laser or the like according to image information by an exposure device 113. To form an electrostatic latent image. The exposure apparatus 113 includes a light emitting unit 113a that emits a laser, a mirror 113b, an fθ lens, and the like. Next, the developing device 114 develops the electrostatic latent image with toner, thereby forming a toner image on the surface of the photosensitive drum 112. The toner image formed on the surface of the photosensitive drum 112 of each image forming station is transferred to the intermediate transfer belt 111 when a primary transfer bias is applied by the primary transfer device 115.

  Such toner image formation is processed in parallel by the Y, M, C, and K image forming stations. Then, the toner images formed at the respective image forming stations are sequentially superimposed and transferred onto the intermediate transfer belt 111 that is conveyed and driven in the direction of arrow A in the drawing. The image forming process for each color is performed at a timing for superimposing the upstream toner image that has been primarily transferred onto the intermediate transfer belt 111. As a result, a full-color toner image is finally formed on the intermediate transfer belt 111 and conveyed to the secondary transfer unit. The toner image on the intermediate transfer belt 111 conveyed to the secondary transfer unit is transferred to the recording material conveyed by the recording material conveyance unit 200.

  The recording material conveyance unit 200 includes a plurality of conveyance rollers and picks up the recording material accommodated in the cassette 201 and conveys it to the image forming unit 110. Specifically, the recording material S is stored in a form of being stacked on a lift-up device included in a cassette (feeding device) 201, and is synchronized with the image forming timing of the image forming unit 110 by the feeding roller 202. Are sent. Here, the feeding means for feeding the recording material may employ a method using separation adsorption by air, in addition to a method using frictional separation by the feeding roller 202 or the like.

  The recording material S sent out by the feeding roller 202 is conveyed to the registration roller 203. Then, after skew correction and timing correction are performed by the registration roller 203, the sheet is sent to the secondary transfer unit. In the secondary transfer unit, the toner image formed on the intermediate transfer belt 111 is transferred to the recording material while the recording material is nipped and conveyed by the intermediate transfer belt 111 and the secondary transfer outer roller 204. A secondary transfer inner roller 111a is provided at a position facing the secondary transfer outer roller 204 across the intermediate transfer belt 111. By applying a secondary transfer bias between these rollers, the toner image on the intermediate transfer belt 111 is transferred to a recording material conveyed by the secondary transfer unit.

  In the illustrated example, the recording material is transported upward from the cassette 201 disposed at the lower portion of the apparatus main body. For this purpose, the recording material transport unit 200 is arranged in a substantially vertical direction on one side of the apparatus main body (the right side as viewed from the front of the apparatus).

  The recording material onto which the toner image has been transferred is heated and pressed by the fixing device 130, whereby the toner image is fixed. The fixing device 130 melts and fixes the toner on the recording material S by applying a predetermined pressing force by the roller pair and a heating effect by a heat source such as a heater. In addition to the roller pair, the fixing device may employ other conventionally known configurations such as a belt pair or a combination of a roller and a belt.

  The recording material S on which the toner image has been fixed passes through the post-fixing conveyance unit 150 and is directly discharged onto the discharge tray 140. In this embodiment, since the plurality of discharge trays 140 are provided, the recording material S is discharged to one of the discharge trays 140. Alternatively, when double-sided image formation is required, the recording material S is conveyed to the reverse conveying device 160, and a toner image is formed on the back surface by the process as described above, and is discharged to one of the discharge trays 140. .

  Further, in the image forming apparatus 100, various units such as a process cartridge including a developing device and a photosensitive drum can be inserted into or removed from the apparatus main body by opening a door (not shown) on the front surface of the apparatus. Yes. Therefore, large openings and cutouts as shown in FIG. 2 are formed on the front surface of the structure 300 of the image forming apparatus 100 in order to exchange various units and insert / remove the cassette 201 in this manner.

[Structure of image forming apparatus]
Next, the structure 300 of the image forming apparatus 100 will be described with reference to FIGS. First, a schematic configuration of the structure body 300 will be described with reference to FIG. The structure 300 includes a frame 301 in which the image forming unit 120 as described above is disposed, and a bottom portion 400 that supports the frame 301. The frame 301 includes a front plate 302 and a rear plate 303 which are a pair of frame bodies arranged to face each other, a plurality of various stays 304, and the like. The frame 301 configured as described above is installed on the bottom portion 400.

[bottom]
Next, the configuration of the bottom 400 will be described with reference to FIGS. As shown in FIGS. 3 and 4, the bottom portion 400 includes a bottom plate portion 410 formed from a plate-like member, and a reinforcing plate 401 that is a reinforcing member that reinforces the bottom plate portion 410. As shown in FIG. 4, the bottom plate portion 410 and the reinforcing plate 401 are formed separately, and the reinforcing plate 401 is fixed to the bottom plate portion 410 by caulking or the like. In addition, in the case of this embodiment, the bottom plate portion 410 and the reinforcing plate 401 are formed by a processing line by a press such as drawing or punching. Since it can process on a processing line, it is preferable. Further, although fixing with screws may be used, there is a possibility that deformation of the bottom portion 400 may increase due to the displacement of the seating surface, so that it is easier to secure rigidity by caulking or welding.

  Further, as shown in FIG. 5, a plurality of installation portions 411 are formed on the bottom surface of the bottom plate portion 410. In the present embodiment, installation portions 411 are provided at four corners (four locations) of the bottom plate portion 410 formed in a substantially rectangular shape when viewed from the lower surface side. As shown in FIGS. 5 and 6, each installation unit 411 is attached with a caster 412 that is a member installed on the installation surface of the apparatus such as a floor surface.

  The member to be installed may be a member such as a foot that is simply placed on the installation surface, other than the member that supports the apparatus movably like the caster 412. Moreover, such a member may be integrally formed with respect to each installation part 411. Further, in the present embodiment, as shown in FIGS. 3 and 4, the anti-slip 413 is provided on the lower surface of the bottom plate portion 410. The anti-slip 413 is for preventing the device from inadvertently moving by contacting the floor (installation surface) after the device is installed, and does not support the load of the device.

[Bottom plate]
Such a bottom plate portion 410 is formed of, for example, a metal plate (plate-like member) such as an electrogalvanized steel plate having a thickness of 1.2 mm. Specifically, a metal plate punched into a predetermined shape and size is subjected to drawing processing by a press to form a concave portion 414, a bent portion 415, and the above-described installation portion 411 as concave shape portions described below. Yes.

  The bent portion 415 is formed by bending the peripheral edge portion of the bottom plate portion 410 downward. Then, the rigidity of the bottom plate portion 410 is increased. Note that the direction in which the bent portion 415 is bent may be upward.

  As shown in FIG. 7A, the recess 414 includes a bottom surface portion 416 and side wall portions 417 on both sides of the bottom surface portion 416 by plastically deforming the metal plate so that a part of the metal plate is recessed. It is formed in the shape to be. The direction in which the concave portion 414 is recessed is the same as the direction in which the bent portion 415 is bent. In the present embodiment, the recess 414 is formed by drawing so as to be recessed downward.

  FIG. 7A is a schematic view of a recess cut by a plane orthogonal to the longitudinal direction of the recess 414. The concave portion 414 is formed so as not to protrude from the lower edge of the bent portion 415 so that the installation portion 411 is within the width of the bottom surface portion 416. In addition, since the rigidity of the baseplate part 410 can be made high, so that the depth of the recessed part 414 is deep, you may make it protrude from the lower end edge of the bending part 415. However, if it does in this way, the dimension of the thickness direction of the baseplate part 410 will become large, and an apparatus will enlarge. Therefore, the depth of the concave portion 414 is preferably set as appropriate in consideration of securing the rigidity of the bottom plate portion 410 and increasing the size of the apparatus. In the present embodiment, the depth H of the recess 414 is set to 22.2 mm, for example.

  The width of the bottom surface portion 416 is not necessarily the same as the whole. For example, the width of the installation portion 411 may be increased and the width of other portions may be decreased. This width is also set as appropriate in consideration of the rigidity of the bottom plate 410. In the present embodiment, the width W of the bottom surface portion 416 is set to 92.5 mm, for example.

  Further, the side wall portion 417 is formed so as to be inclined at an angle θ with respect to the bottom surface portion 416. That is, the pair of side wall portions 417 formed on both sides of the bottom surface portion 416 are inclined in a direction away from each other as the distance from the bottom surface portion 416 increases. The concave portion 414 is formed by pressing a metal plate, but the side wall portion 417 is inclined as described above so that the mold can be easily removed during pressing. In this embodiment, the angle θ is 45 °. Such a side wall part 417 is formed so that the plane part 418 and the bottom face part 416 which are around the recessed part 414 of the bottom plate part 410 may be continuous.

  In addition to the concave portion 414 shown in FIG. 7A, the concave shape portion formed by the bottom plate portion has other shapes such as the concave portion 601 shown in FIG. 7B and the concave portion 602 shown in FIG. 7C. It is also good. The recess 601 of the first example shown in FIG. 7B is recessed so as to be curved, and the recess 602 of the second example shown in FIG. 7C is formed so that a part of the recess protrudes. Has been. As described above, various shapes can be adopted as the concave shape portion as long as the shape of the bottom plate portion 410 can be increased by denting the metal plate.

  In the case of the present embodiment, as shown in FIG. 8, the recesses 414 as described above include a plurality of installation parts 411 so as to intersect inside a range α surrounded by a line connecting adjacent installation parts at the shortest distance. It is formed to tie. In the present embodiment, the shortest distance between the installation parts is the distance between the centers of the installation parts 411.

  In the present embodiment, since the plurality of installation portions 411 are provided at four locations on the bottom plate portion 410, the recesses 414 are formed on a rectangular diagonal formed by the four installation portions 411. That is, the recess 414 is formed by intersecting the first recess 414A and the second recess 414B. The first recessed portion 414A is formed so as to connect the upper right installation portion 411 and the lower left installation portion 411 with a straight line, and has a shape as shown in FIG. The second concave portion 414B is formed so as to connect the upper left installation portion 411 and the lower right installation portion 411 of FIG. 8 with a straight line, and has a shape as shown in FIG. And the part which 414A of 1st recessed parts and 2nd recessed part 414B cross | intersect is formed so that it may be located in the above-mentioned range (alpha).

  In addition, the part where 414A of 1st recessed parts and 2nd recessed part 414B cross | intersect is the range of the area | region (beta) enclosed by the line | wire which connected the innermost points (point nearest to the center of the baseplate part 410) of each installation part 411. It is preferable to be inside. Furthermore, it is preferable that the position of the center of gravity of the image forming apparatus 100 falls within a range γ where the first recess 414A and the second recess 414B intersect. For this reason, when the center of gravity is configured to deviate from the region γ shown in FIG. 8, the region where the first recess 414A and the second recess 414B intersect may be shifted from the position shown in FIG. . For example, at least one of the first concave portion 414A and the second concave portion 414B is not connected by connecting the installation portions with a straight line, but is connected by bending or bending, so that the center of gravity position of the apparatus Shift it so that it falls within that area.

[Reinforcement plate]
The reinforcing plate 401 is a metal plate (plate member) such as an electrogalvanized steel plate having a plate thickness of 1.55 mm, for example. In the present embodiment, a metal plate made of the same material as the bottom plate portion 410 is used as the reinforcing plate 401, but the material can be selected as appropriate. Further, regarding the plate thickness, the reinforcing plate 401 is thicker than the bottom plate portion 410, but this can also be set as appropriate. In order to increase the rigidity of the bottom 400, it is preferable to increase the thickness of the bottom plate 410. On the other hand, in order to achieve cost reduction while ensuring rigidity, the plate thickness of the reinforcing plate 401 that is smaller in area than the bottom plate portion 410 and is not subjected to drawing or the like is larger than the plate thickness of the bottom plate portion 410. It is preferable to do.

  Such a reinforcing plate 401 is fixed to the bottom plate portion 410 by caulking or the like as described above. Specifically, the reinforcing plate 401 is fixed to the plurality of regions 419A to 419D so as to connect the plurality of regions 419A, 419B, 419C, and 419D divided by the recess 414 in the bottom plate portion 410, respectively. . That is, the bottom plate portion 410 is divided into four regions 419A to 419D as shown in FIG. 8 by forming the concave portion 414 as described above. In these four regions 419A to 419D, step surfaces 420A, 420B, 420C formed so as to be recessed in the same direction as the concave portion 414 with respect to the flat portion 418 on the far side near the region γ where the concave portion 414 intersects. 420D. And the reinforcement board 401 is being fixed to these level | step difference surfaces 420A-420D as a fixing | fixed part, respectively.

  The level difference surfaces 420A to 420D are formed in parallel to the virtual plane so as to be positioned between the horizontal plane (virtual plane) passing through the upper end and the lower end of the bent portion 415 of the bottom plate portion 410. In other words, the step surfaces 420A to 420D are formed within a range in the thickness direction of a substantially rectangular parallelepiped in which the dimension of the bent portion 415 in the bending direction is the thickness dimension. The amount of the reinforcing plate 401 fixed to the step surfaces 420A to 420D protrudes from the virtual plane (substantially rectangular parallelepiped thickness direction) is reduced or eliminated, and the dimension of the bottom portion 400 in the thickness direction is made as small as possible. Like to do. In the present embodiment, the step surfaces 420A to 420D are formed so that the reinforcing plate 401 does not protrude from the virtual plane (substantially rectangular parallelepiped thickness direction). In other words, the depth of the step surfaces 420 </ b> A to 420 </ b> D is greater than or equal to the thickness of the reinforcing plate 401.

  In addition, the reinforcing plate 401 is formed in an octagonal shape in the present embodiment so as to be fixed to the step surfaces 420A to 420D, respectively. However, the shape of the reinforcing plate 401 is not limited to such an octagonal shape, and may be other shapes such as a rectangular shape as long as the stepped surfaces 420A to 420D can be connected to each other. However, since the reinforcing plate 401 is formed by punching a plate-like member, it is preferable that the reinforcing plate 401 has a shape with good yield. Further, regarding the area of the reinforcing plate 401, it is preferable to make it as small as possible within a range where the rigidity of the bottom portion 400 can be sufficiently increased, so that the cost can be reduced, and the area of the reinforcing plate 401 is within the above-described range shown in FIG. It is preferable to make it smaller than α. More preferably, the area of the reinforcing plate 401 is made smaller than the area occupied by the region β connecting the innermost points of each installation portion 411. More specifically, the area of the reinforcing plate 401 is preferably 50% or less with respect to the entire area of the bottom plate portion 410. More preferably, the area of the reinforcing plate 401 is 30% or less with respect to the entire area of the bottom plate portion 410. The reinforcing plate 401 is preferably provided within the range α described above. In the present embodiment, the reinforcing plate 401 is provided within the range of the above-described region β, which is a range narrower than the range α, so that both rigidity can be secured and cost can be reduced.

[Effect of this embodiment]
In the case of the present embodiment, as described above, the bottom 400 is formed by fixing the bottom plate 410 and the reinforcing plate 401, which are formed by forming the concave portion 414 that is a concave shape by plastically deforming the plate-like member. Yes. For this reason, the rigidity of the bottom 400 of the structure 300 can be increased at low cost. That is, as in the present embodiment, when the image forming apparatus 100 is installed on an installation surface such as a floor surface at four points, the image forming apparatus 100 is stable on a plane formed by three points with respect to the installation surface. For this reason, at least one of the installation positions of the installation parts 411 is different, and the bottom part 400 is likely to be bent or twisted. Therefore, in this embodiment, by connecting the installation portions 411 with the recesses 414, the rigidity in the twisting direction caused by the different installation positions of the installation portions 411 connected by the recesses 414 can be increased. At the same time, by providing the reinforcing plate 401, the rigidity with respect to the torsional direction centered on the line in the direction along the recess 414 can be increased.

  More specifically, the deformation that occurs in the vicinity of the installation portion 411 due to the stress received from the installation surface is suppressed by tying each installation portion 411 to the recess 414. At this time, if only the recess 414 is formed, it is difficult to suppress deformation around the lines in the longitudinal direction (direction along the recess 414) of the first recess 414A and the second recess 414B constituting the recess 414. . For this reason, the deformation | transformation of this direction can be efficiently suppressed by fixing the reinforcement board 401 to the baseplate part 410 so that several area | region 419A-419D divided | segmented by the recessed part 414 may be mutually connected.

  Further, the bottom plate portion 410 is merely formed by drawing a plate-like member to form the installation portion 411, the concave portion 414, the bent portion 415, and the like. The reinforcing plate 401 is simply formed by punching a plate-like member, has a simple plate shape that is not subjected to drawing processing, and has a sufficiently smaller area than the bottom plate portion 410. Specifically, the area occupied by the reinforcing plate 401 is more than the area occupied by the region α connecting the innermost points of each installation part 411 than the area occupied by the range α connecting each installation part 411. Is small. For this reason, the rigidity of the bottom part 400 can be made high, reducing processing cost and material cost. In addition, the weight can be reduced by reducing the amount of the material.

[Example]
Next, an experiment conducted for examining the effect of this embodiment will be described. In the experiment, a configuration (comparative example) using a bottom portion formed in a box shape by combining two sheet metals as described in Patent Document 1 described above and the bottom portion 400 described in the above-described embodiment were used. The configuration (Example) was compared. In addition, it was set as the structure installed in four points similarly to this embodiment also in a comparative example. Specifically, the structure of the example and the structure of the comparative example were respectively created by combining the frame shown in FIG. 2 described above, the bottom of the example, and the bottom of the comparative example. Then, the image forming unit shown in FIG. 1 described above was incorporated into each structure, and the image forming apparatus of the example and the image forming apparatus of the comparative example were respectively configured. That is, the conditions other than the bottom are the same in the example and the comparative example. Then, when viewed from the front side of the image forming apparatus (left front side in FIG. 2), when installed at an installation unit other than the left front installation unit, and when installed at an installation unit other than the left rear installation unit The maximum amount of deformation at the bottom was compared. Moreover, each weight of the bottom part of an Example and a comparative example was compared. The result is shown in FIG.

  In FIG. 9, a white bar graph indicates a comparative example, and a hatched bar graph indicates an example. Moreover, the deformation amount and weight of the example when the comparative example is 100% are shown. “Left front” shown at the left end of FIG. 9 is a deformation amount when installed in an installation portion other than the left front installation portion, and in the example, it was 88% of the comparative example. The “left rear” shown in the center of FIG. 9 is the amount of deformation when installed in an installation part other than the installation part with the left rear, and in the example, it was 93% of the comparative example. The “weight” shown at the right end of FIG. 9 is the weight of the bottom, and in the example, it was 54% of the comparative example. As is clear from this experiment, it was confirmed that the deformation amount and the weight of the bottom portion can be sufficiently reduced in the case of the example having the configuration of the present embodiment compared to the comparative example. That is, it was confirmed that the rigidity of the bottom can be increased with a small amount of material.

  As described above, in the present embodiment, the deformation in the twisting direction due to the force applied to the installation portion 411 by the concave portion 414 of the bottom plate portion 410 is suppressed. In addition, the rigidity in the twist direction is further improved by adding a reinforcing plate 401 having a minimum size that reinforces the bottom plate portion 410 in which the concave portion 414 is formed. Accordingly, the cost including the number of parts of the bottom portion 400, the material cost, and the processing cost can be reduced while realizing rigidity equal to or higher than that of the box-shaped double bottom plate as in the comparative example.

<Second Embodiment>
A second embodiment of the present invention will be described with reference to FIG. The bottom portion 400a of the present embodiment has three installation portions 411 formed on the bottom plate portion 410a, and in accordance therewith, the shape of the concave portion 414a that is a concave shape portion and the shape of the reinforcing plate 401a are the same as those of the first embodiment. It is different. Since other configurations and operations are the same as those of the first embodiment, the description and illustration of the same configurations as those of the first embodiment are omitted or simplified, and hereinafter, different parts from the first embodiment are mainly described. Explained.

  In the case of this embodiment, the some installation part 411 is provided in three places of the baseplate part 410a. Of the three installation portions 411, the two installation portions 411 are provided on the side where the weight of the image forming apparatus 100 (see FIG. 1) is increased, and the remaining one installation portion 411 is provided on the opposite side. It has been. In the image forming apparatus 100 according to the present embodiment, heavy objects such as a substrate, a power source, and various motors are arranged on the back side, so that the center of gravity is located on the back side. For this reason, the two installation portions 411 on the lower side in FIG. 10 are provided on the back side of the image forming apparatus 100, and the one installation portion 411 on the upper side in FIG. 10 is provided on the front side.

  Then, a plurality of installation portions are formed such that the concave portion 414a having the shape as shown in FIG. 7A described above intersects the inside of a range α ′ surrounded by a line connecting adjacent installation portions at the shortest distance. 411 is formed. Specifically, the recesses 414a intersect with each other on the inner side of the triangle formed by the three installation portions 411. That is, the first concave portion 414aA, the second concave portion 414aB, and the third concave portion 414aC are formed along a line extending from one installation portion 411 toward the opposite side of the triangle. The first concave portion 414aA, the second concave portion 414aB, and the third concave portion 414aC are made to intersect inside the above-described range α ′. In other words, the concave portion 414a is configured by a three-pronged aperture shape extending from the approximate center of the triangle formed by the three installation portions 411 to each installation portion 411.

  The position where the recesses 414a intersect is preferably the position of the center of gravity of the triangle formed by the three installation portions 411 (first condition). In the case of the present embodiment, it is preferable that the position of the center of gravity of the image forming apparatus 100 falls within a region γ ′ where the first recess 414aA, the second recess 414aB, and the third recess 414aC intersect (second condition). It is preferable to satisfy both the first condition and the second condition, but it is preferable to satisfy at least one of the conditions depending on the shape of the bottom plate portion 410a and the installation position of the installation unit 411.

  The reinforcing plate 401a is fixed to the plurality of regions 419aA to 419aC so as to connect the plurality of regions 419aA, 419aB, and 419aC divided by the recess 414a in the bottom plate portion 410a. That is, the bottom plate portion 410a is divided into three regions 419aA to 419aC by forming the concave portion 414a as described above. In these three regions 419aA to 419aC, step surfaces 420aA, 420aB, and 420aC formed so as to be recessed in the same direction as the recessed portion 414a with respect to the flat portion 418 on the side farther from the region γ ′ where the recessed portion 414a intersects. Have And the reinforcement board 401a is being fixed to these level | step difference surfaces 420aA-420aC as a fixing | fixed part, respectively.

  In addition, the reinforcing plate 401a is formed in a pentagonal shape in this embodiment so as to be fixed to the step surfaces 420aA to 420aC, respectively. However, the shape of the reinforcing plate 401a is not limited to such a pentagonal shape, and may be other shapes such as a triangular shape and a trapezoidal shape as long as the stepped surfaces 420aA to 420aC can be connected to each other. Further, with respect to the area of the reinforcing plate 401a, it is preferable to make it as small as possible within a range where the rigidity of the bottom portion 400a can be sufficiently increased, so that the cost can be reduced, and the reinforcing plate 401a is in the above range α ′ shown in FIG. It is preferable to provide within the range. In this embodiment, a part of the reinforcing plate 401a protrudes beyond the range α ′, but the area occupied by the reinforcing plate 401a is 80% or more, preferably 90% or more, more preferably 95% or more within the range α ′. It only has to be inside. This is the same in the first embodiment.

  Also in this embodiment, the bottom plate portion 410a is plastically deformed to form the recess 414a and the installation portion 411. Along with this, a plurality of regions 419aA to 419aC divided by the recess 414a of the bottom plate portion 410a of the reinforcing plate 401a having a simple plate shape are fixed to each other. Thereby, the rigidity of the bottom 400a can be increased at low cost.

<Third Embodiment>
A third embodiment of the present invention will be described with reference to FIGS. The configuration of the bottom portion 400b of this embodiment is substantially the same as that of the first embodiment, but this embodiment is characterized by the configuration of the installation portions 411 and 411a, and this will be described in detail below. In addition, about the part similar to 1st Embodiment, illustration and description are abbreviate | omitted or simplified.

  Also in the present embodiment, four installation portions 411 and 411a are formed on the bottom plate portion 410b of the bottom portion 400b. The installation part 411 on the lower side of FIGS. 11 and 12 has the same shape as the installation part 411 of the first embodiment. On the other hand, the upper installation portion 411a in FIGS. 11 and 12 is formed so that the region 500 to which the caster 412 is fixed and the region 501 to which the anti-slip 413 (see FIG. 3 and the like) is fixed are continuous. . Each such installation part 411, 411a is tied by the recessed part 414 similarly to 1st Embodiment. Since the configuration of the portions to which the casters 412 of the respective installation portions 411 and 411a are fixed is the same, the lower installation portion 411 in FIG. 11 will be described below with reference to FIG.

  As shown in FIG. 13, the plurality of installation portions 411 (411 a) include an attachment surface portion 510 formed by plastically deforming a metal plate (plate-like member) that is a material of the bottom plate portion 410 b, and an attachment sidewall portion. 520. The attachment surface portion 510 is formed in a substantially rectangular shape, and a caster 412 that is a member to be installed on the installation surface of the apparatus is attached to the bottom surface portion 416 on the opposite side of the concave portion 414. For this purpose, the attachment surface portion 510 is formed with attachment holes 511 for attaching the casters 412 and a plurality of fixing holes 512 for fastening the casters 412 with screws.

  The attachment side wall portion 520 is formed in a continuous plane so as to make the attachment surface portion 510 and the concave portion 414 continuous and surround at least two sides around the attachment surface portion 510. In the present embodiment, the attachment side wall portion 520 is erected so as to be inclined at an angle of, for example, 45 ° with respect to the attachment surface portion 510 so as to surround two sides around the attachment surface portion 510. One end side of the mounting side wall portion 520 in the standing direction is continuous to the mounting surface portion 510 via the smooth curved portion, and the other end side is continuous to the bottom surface portion 416 of the concave portion 414 via the smooth curved portion.

  In addition, the mounting side wall 520 includes a first side wall 521 and a second side wall 522 arranged so as to be orthogonal to each other, and a curved portion 523 that smoothly connects the first side wall 521 and the second side wall 522. And have. Each of the first side wall portion 521 and the second side wall portion 522 is provided along one side of a substantially rectangular attachment surface portion 510. The end portions of the first side wall portion 521 and the second side wall portion 522 opposite to the curved portion 523 are continuous via the side wall portion 417 of the concave portion 414 and the smooth curved portions 524 and 525, respectively. As shown in FIG. 14, a caster 412 is attached to the attachment surface portion 510 of the installation portion 411 (411a) configured as described above.

  In the case of this embodiment configured as described above, the plate-shaped member is plastically deformed to form the installation portions 411 and 411a. Therefore, the rigidity of the installation portions 411 and 411a can be increased at low cost. That is, the installation part 411 (411a) has the attachment side wall part 520 formed in a continuous plane so as to surround two sides around the substantially rectangular attachment surface part 510 to which the caster 412 is attached. For this reason, the deformation | transformation which generate | occur | produces with the stress which acts on the installation part 411 via the caster 412 can be suppressed. Moreover, since the attachment side wall part 520 is continuously formed with the recessed part 414, a deformation | transformation can be suppressed more.

  Further, the first side wall part 521 and the second side wall part 522 of the attachment side wall part 520 are continuous by the curved part 523. Further, the attachment side wall portion 520 is continuous with the attachment surface portion 510, the bottom surface portion 416 of the concave portion 414, and the side wall portion 417 through smooth curved portions, respectively. For this reason, even when a force is applied to the installation portion 411 (411a), the concentration of stress can be reduced and the durability can be improved.

<Fourth Embodiment>
A fourth embodiment of the present invention will be described with reference to FIG. In the case of this embodiment, the attachment side wall part 520a which comprises the installation part 411b is formed in the continuous plane so that the surroundings (4 sides) of the substantially rectangular attachment surface part 510 may be enclosed. Thereby, the rigidity of the installation part 411b can be made higher. However, the installation portion 411b becomes larger by surrounding the entire periphery of the attachment surface portion 510 with the attachment side wall portion 520a. Therefore, it is suitable for a configuration in which the shape of the bottom portion is larger than in the case of the third embodiment described above and the weight of the device is large. Other configurations and operations are the same as those of the above-described third embodiment.

<Other embodiments>
The third and fourth embodiments described above can of course be applied to the configuration of the second embodiment. Further, the configuration of the installation portions 411, 411a, and 411b described in the third and fourth embodiments can be applied to a bottom plate portion having a concave shape portion such as a concave portion. In this case, the first and second configurations are not necessarily required. It does not have to be a configuration having a reinforcing plate as in the embodiment. Further, in this case, the present invention can be applied to a configuration in which the concave portions formed in the bottom plate portion do not intersect and a configuration of the installation portions 411, 411a, and 411b.

  Further, in each of the above-described embodiments, the concave shape portion such as the concave portion 414 is made to intersect within the range α, but the concave shape portion may be formed in another portion in addition to this. Further, the reinforcing plate is not limited to the plate-like member, and may be constituted by a plurality of rod-like members, for example. In this case, the rod-shaped member is provided so that all of the plurality of regions divided by the recesses are connected to each other in the bottom plate portion. For example, if there are four areas, one area is connected to all three other areas. Furthermore, the installation part should just be formed in three or more places of a baseplate part, and the installation part may be five or more places.

  The image forming apparatus to which the present invention can be applied is not limited to the tandem configuration shown in FIG. 1, for example, a plurality of developing devices are arranged in a cylindrical shape to form a toner image on one photosensitive drum. Other configurations such as a rotary system may be used. In addition to the intermediate transfer method using an intermediate transfer member such as an intermediate transfer belt as shown in FIG. 1, the image forming apparatus to which the present invention can be applied is a direct transfer method that transfers directly from a photosensitive drum to a recording material. There may be.

  DESCRIPTION OF SYMBOLS 100 ... Image forming apparatus / 120 ... Image forming unit / 300 ... Structure / 301 ... Frame / 400 ... Bottom / 401, 401a ... Reinforcing plate (reinforcing member) / 410, 410a, 410b ... bottom plate part / 411, 411a, 411b ... installation part / 412 ... caster (member to install) / 414, 601, 602 ... concave part (concave part) / 415 ... Bending part / 416 ... Bottom part / 417 ... Side wall part / 418 ... Plane part / 419A, 419B, 419C, 419D, 419aA, 419aB, 419aC ... Area / 420A, 420B, 420C, 420D, 420aA, 420aB, 420aC ... Step surface (fixed portion) / 510 ... Mounting surface portion / 520 ... Mounting side wall portion

Claims (1)

A frame in which an image forming unit is disposed;
A bottom portion for supporting the frame,
The bottom portion includes a bottom plate portion formed from a plate-like member, and a reinforcing member that reinforces the bottom plate portion,
The bottom plate portion is a line in which a member to be installed on the installation surface of the apparatus is attached, or a plurality of three or more installation portions formed integrally with the member and the adjacent installation portions are connected at a shortest distance. And connecting the plurality of installation portions so as to intersect each other inside a range surrounded by a concave portion formed by plastically deforming the plate-like member so that a part of the plate-like member is recessed. And
The reinforcing member is fixed to each of the plurality of regions so as to connect the plurality of regions divided by the concave portion of the bottom plate portion,
The area of the reinforcing member is smaller than the area of the range;
A structure of an image forming apparatus.

Images