JP3304149B2 - Structure of image forming apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an image forming apparatus.

[0002]

2. Description of the Related Art An image forming apparatus configured as an electronic copying machine, a printer, a facsimile, or the like has various process units such as an optical unit, a photosensitive member, a developing unit, a cleaning unit, a fixing unit, and a paper feeding device. These are assembled to the structure of the image forming apparatus. The structure of a conventional image forming apparatus is constituted by fixing a side plate of a unit on a base member, and the structure has a side plate made of a plate material and a base member (for example, Japanese Utility Model Application Laid-Open No. 58-149745). Gazette
051, JP-A-63-194345, JP-A-64-2247, and JP-A-4-26863.

Incidentally, many of the above-described image forming apparatuses are configured such that each unit can be pulled out to the front side so that maintenance and inspection work such as component replacement and cleaning can be easily performed. In order to be able to pull out the unit in this manner, a large opening or notch is formed in the front side plate constituting the structure so that the unit does not interfere with the front side plate when the unit is pulled out. Need to be prevented.

However, if the above-described large access port is formed in a side plate made of a sheet material such as a sheet metal, its rigidity is reduced, and sufficient strength may not be obtained. In particular, as the number of units increases, such as an image forming apparatus in which a plurality of developing units are provided around a photoreceptor and can be pulled out, a larger entrance port must be formed in the front side plate. And its rigidity is remarkably reduced.

Conventionally, however, the rigidity of the structure has been compensated for by increasing the thickness of the side plate constituting the structure or by reinforcing the side plate by adding a large number of reinforcing members. According to the body, the structure becomes complicated, and the work for assembling the structure has to be very complicated.

On the other hand, in developing a recent image forming apparatus, a plurality of types of image forming apparatuses having different image forming speeds are simultaneously developed so that a user can purchase a product most suited to his or her own needs. I have. At that time, if the image forming speed increases, the load applied to each unit of the image forming apparatus and the operating speed of the unit itself also increase, so that the size and weight increase. That is, the weight and size of each unit differs depending on the performance of the image forming apparatus. In this case, since the conventional structure is configured to support each unit by the side plate, if the size or weight of the unit changes, the structure and strength of the side plate, that is, the structure itself must also be changed. . For this reason,
Not only does the manufacturing operation become complicated, but a common structure cannot be used for many types of image forming apparatuses. Recently, the idea that common parts should be used as much as possible for different types of image forming apparatuses in order to reduce costs and increase manufacturing efficiency has become mainstream. The inability to use a common structure for these models violates such a requirement.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a structure of an image forming apparatus which overcomes the above-mentioned drawbacks.

[0008]

According to the present invention, in order to achieve the above object, a base member and a plurality of channel-shaped frame members having a U-shaped cross section are assembled, and these members are assembled. The frame member is fixed by at least one of spot welding and plug welding to form a skeleton, and the base member is constituted by an upper sheet metal member and a lower sheet metal member assembled to each other, and these sheet metal members are spot-welded. And an at least one welding method of plug welding, and a lower surface of the upper sheet metal member is used as a caster mounting surface.

[0009]

[0010]

Further, in the above configuration, it is advantageous that the optical unit of the image forming apparatus is positioned and supported on the skeleton via at least two pins.

In each of the above structures, it is advantageous that the opening and closing body of the image forming apparatus is pivotally mounted on the upper part of the skeleton.

Further, in each of the above structures, it is desirable that the channel-shaped frame member is disposed with its opening side facing the inside of the structure.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram schematically showing an electronic copying machine which is an example of an image forming apparatus. In order to understand the present invention, first, the overall configuration and operation will be briefly described.

The copying machine shown in FIG. 1 is generally called a console-type copying machine, and has a high overall height so that the copying machine can be mounted on the floor surface and used as a whole. 1 and a lower part 2. Top one
Is an optical unit 4 containing an optical element in a case 3
The lower part 2 has a plurality of paper feeders 5, and the copying machine shown in FIG. Transfer device (AD
F) 6 is mounted.

A document (not shown) placed on a document table 7 of the automatic document feeder 6 is automatically fed onto a contact glass 8 supported by the case 3 of the optical unit 4 and stopped. Next, the light source 9 of the optical unit 4 moves rightward from the position shown in FIG. 1, and at this time, the original surface is illuminated by the light source 9, and the original image is formed on the photoreceptor 11 by the imaging optical system 10. Is done.

The photoreceptor 11 rotates clockwise in FIG. 1. At this time, the surface of the photoreceptor is uniformly charged by the charging charger 12, and the original image is formed on the charged surface as described above. As a result, an electrostatic latent image is formed on the photoconductor 11, and this latent image is visualized as a toner image by the developing unit 13.

On the other hand, the transfer paper 14 is fed toward the photoreceptor 11 from one of the paper feeding devices 5 arranged in the lower part 2,
The toner image on the photoconductor 11 is transferred to the transfer paper 14 by the transfer charger 15. This transfer paper is in the fixing unit 1
6, the toner image transferred at this time is fixed on the transfer paper, and then the transfer paper is discharged outside the machine as copy paper. Although the copying machine shown in FIG. 1 is configured to be capable of performing double-sided copying, its description is omitted here.

The toner remaining on the photosensitive member 11 after the transfer of the toner image is removed by the cleaning unit 53.

As described above, the copying machine shown in FIG. 1 has various parts and units, which are supported by the structure according to the present invention. FIG. 2 is a perspective view showing an example of the structure during the manufacturing process.

The structure shown in FIG. 2 has an upper skeleton 17 and a lower skeleton 18. The upper skeleton 17 is a structure for the above-described upper part 1, and includes the above-described photoreceptor 11, developing Unit 13, cleaning unit 53 and fixing unit 1
6 and the like. The lower skeleton 18 is a structure for the lower part 2 of the copying machine and supports the sheet feeding device 5 and the like.

First, the lower skeleton body 18 includes a base member 19 located at the bottom thereof and a plurality of skeleton members 20, 21, 22, 23, 24, 25, 26,
27 and 28, which are integrally fixed by welding. As shown in FIGS. 4 to 7, the base member 19 is formed by assembling an upper sheet metal member 29 and a lower sheet metal member 30 which have been subjected to a drawing process and fixing them together by welding. At the four corners of the member 29, the lower portions of the four frame members 20, 21, 22, and 23, which stand vertically, are fixed by welding as shown in FIG.

The direction indicated by arrow A in FIG. 2 is the front side of the copying machine, that is, the side facing the normal operator, and the side indicated by arrow B is the back side. When the operator faces the copying machine, the horizontal direction is indicated by an arrow C in FIG.

As described above, of the four frame members 20, 21, 22, 23 fixed to the base member 19, the upper part of the two members 20, 22 on the near side and the two members on the rear side. 2
Frame members 24, 25 extending in the left-right direction are fixed to the upper portions of the upper and lower portions by welding, respectively.
Each end of a frame member 26 extending forward and backward is fixed to the two frame members 20 and one frame member 21 on the back side by welding. Similarly, the ends of the two skeleton members 27 and 28 extending forward and backward are also fixed to the front and rear skeleton members 24 and 25 by welding. At the time of actual production, the four frame members 24, 25, 27, 28 are integrally assembled and connected as shown in FIG.
The work efficiency is good if it is fixed to the upper part of 22,22.

On the other hand, the upper skeleton body 17 also has four framing members 31, 32, 33 and 34 assembled in a rectangular shape, and if necessary, a reinforcing framing member 35 is assembled thereto, and these are welded together. A lower structure part fixed to each other, four vertically standing frame members 36, 37, 38, 39 fixed to the structure part by welding;
Frame members 40 fixed by welding to the upper portions of 8, 39
A frame member 50 welded to the upper portions of the front frame members 36 and 37; and a front and rear frame members 36, 38 and 37, 3
9 has frame members 41 and 42 integrated by welding.

The frame member 25 on the back side of the lower skeleton body 18
At least two pins 46 projecting upward are fixed to the left and right of the upper part of the upper frame 17. These pins 46 are attached to the mounting holes 4 formed in the upper frame 17 at the back of the frame members 31 and 33.
7 (only one of them is shown in FIG. 2).
In this way, the two skeletons 17 and 18 are connected to each other via the pins 46 and positioned. At this time, one of the pair of mounting holes 47 may be an elongated hole.

The optical unit 4 shown in FIG. 1 is supported on the upper skeleton 17 of the structure constructed as described above as shown in FIG. At this time, at least two pins 48 projecting upward are fixed to the frame members 41 and 42 constituting the beams of the upper skeleton body 17, as shown in FIG. And the optical unit is positioned with respect to the structure. Also in this case, one of the holes can be a long hole. In this manner, the optical unit 4 is positioned and supported by the upper skeleton 17 via at least two pins 48. Thereafter, the tongue piece 49 formed by cutting and raising the case 3 and the frame member of the lower skeleton body 18 are fixed by screws (not shown), and the optical unit 4 is immovably supported by the structure.

Next, another part of the upper skeleton 17 is formed.
One frame member 43 is fixed to the upper portion of the frame members 38 and 39 by welding. The reason that the frame member 43 is fixed after the optical unit 4 is assembled is that the scanner motor 51 protrudes to a portion on the back side of the optical unit 4.
If the frame member 43 is attached first, the optical unit 4
Can not be assembled. When a flat scanner motor with a small amount of protrusion is used, the frame member 4
The optical unit 4 may be assembled after the 3 is fixed to the upright frame members 38 and 39. Rather, this can increase the rigidity of the structure.

The automatic document feeder 6 shown in FIG. 1 and the respective units or parts inside the copying machine are respectively assembled to the above-described structure, and an outer cover is attached to the outer peripheral portion of the copying machine. Is completed. Photoconductor 11, developing unit 13, fixing unit 6 or cleaning unit 5
To assemble each unit such as 3 into the structure, for example,
These units or their side plates may be directly attached to a vertically standing frame member of the structure, or another sheet metal member may be fixed to the structure, and each unit may be attached to this. Good. In any case, the photoconductor 11, the developing unit 13, the fixing unit 16 and the like are supported so as to be able to be pulled out to the near side with respect to the structure.

As described above, the structure of the copying machine shown in FIG. 1 is composed of the frame members 17 and 18 to which the frame members are assembled as shown in FIGS. 2 and 3, so that the overall rigidity is reduced. It can be significantly higher than before. Therefore, although the copier is configured so that each unit can be pulled out to the front side, the rigidity of the structural body does not become insufficient, and the structure can be simplified as compared with the related art.

Further, the side plate of each unit does not substantially bear the rigidity for supporting the unit, but the overall rigidity is maintained by the structure formed by assembling the frame members. The same structure can be used for a wide variety of copying machines from high-speed to high-speed models, and common parts can be widely used.

Further, in the conventional console type image forming apparatus, it is necessary to arrange an intermediate sheet metal made of a large plate material between the upper and lower structural parts to increase the rigidity of the structural body. According to this configuration, for example, when there are parts that protrude upward at the lower part of the copier, or when there are parts that protrude downward at the upper part, the upper part and the lower part do not interfere with the intermediate sheet metal. A large space had to be taken between the lower part. For this reason, the height of the image forming apparatus is unnecessarily large, and it has been difficult to reduce the size of the apparatus.

On the other hand, when a structure having a skeleton as shown in FIGS. 2 and 3 is used, the rigidity of the entire structure is increased, and the intermediate sheet metal required for the conventional structure is unnecessary. Since the space S (FIG. 3) originally exists in the structure between the upper part 1 and the lower part 2 shown in FIG.
Parts of the upper part 1 or the lower part 2 can protrude into this space, and there is no need to particularly consider the interference between these parts and the structure. Therefore, it is not necessary to form a large space serving as a dead space between the upper part and the lower part as in the related art, and the height of the copying machine can be reduced.

As described above, the automatic document feeder 6 is assembled to the structure, and the transfer device is supported to be freely openable and closable with the back side of the copying machine as a fulcrum. 6, the original can be manually placed on the contact glass 8 (FIG. 1).
As described above, the automatic document feeder 6 constitutes an example of the opening / closing body of the image forming apparatus.

As shown in FIG. 3, the automatic document feeder 6 has support members 54 and 55 fixed to the upper surfaces of the frame members 40 and 43 of the upper skeleton 17 by, for example, screws.
, Via a hinge (not shown). In this manner, the rear base end of the automatic document feeder constituting the opening / closing body is pivotally attached to the upper part of the skeleton body.
The skeletal body portion to which 55 is fixed is frame members 38, 39, 4
0, 43, the rigidity is greatly increased. Therefore, when the automatic document feeder 6 is opened and closed, a load or a torsional moment applied to the hinge of the automatic document feeder 6 acts on the optical unit 4 located near the hinge. Absent. For this reason,
The case 3 of the optical unit 4 is not deformed and the imaging characteristics are not deteriorated, and the scanning operation of the scanner is not adversely affected.

In place of the automatic document feeder, a pressure plate for pressing a document on the contact glass 8 may be used.
Such a pressure plate also constitutes an opening / closing body which is opened and closed with the back side of the copying machine as a fulcrum. In the same manner as described above, this pressure plate also has a skeletal body via the base members 54 and 55 and hinges, for example. 17 can be pivoted. This also prevents a problem that the opening and closing operation of the pressure plate adversely affects the optical unit 4.

Conventionally, the automatic document feeder unit and the pressure plate have been directly pivoted to the optical unit by means of hinges, so that the load and torsional moment generated at the hinges when opening and closing these opening and closing members directly act on the optical unit. Although there was a risk of deteriorating the imaging characteristics, in the configuration shown in the figure, since the opening and closing body of the image forming apparatus was pivotally mounted on the upper part of the skeleton 17,
It is possible to avoid the conventional problems.

The structure of the present embodiment is divided into an upper skeleton 17 and a lower skeleton 18, which are connected via pins 46.
8 can be easily removed. For example, when the copier supplier brings the copier to the user, or when inspecting or repairing the inside of the copier, the two skeletons 1 are used.
If the members 7 and 18 are separated from each other, a predetermined operation can be easily performed. When assembling the two skeletons 17 and 18 again, it is only necessary to fit the pin 46 and the mounting hole 47, and the operation is not only extremely simple, but also the two can be correctly positioned and assembled.

Since the optical unit 4 is also positioned above the skeleton 17 via the pins 48, in the case of an analog type copying machine as shown in FIG. Can be positioned with high accuracy, and a high-quality image can be formed. In the case of a digital image forming apparatus, it is not necessary to directly accurately position the optical system (reading scanning system) and the image forming system. For example, it is also possible to arrange a damper (not shown) on the upper surface of the frame members 41 and 42 shown in FIG. 2 and to couple the optical unit 4 to the structure via the damper.

By the way, as described above, each skeleton 17, 1
Reference numeral 8 denotes a method of assembling a plurality of framing members and joining them by welding. The framing members are made of, for example, a mild steel plate, and are formed by bending or using this in combination with drawing. Thereby, it is formed in a channel shape. In FIG. 2, the cross-sectional shape of each framing member is shown by adding a broken line, and as can be seen, most of the framing members have a U-shaped cross-sectional shape. No. Only the two frame members 38, 39 of the upper skeleton 17 have a cross-sectional shape in which two U-shaped cross sections are continuous, and holes 44, 45 for reducing the weight are cut out at the center thereof. It is formed as follows.

In any case, each framing member is formed in a channel shape and they are assembled to each other. When the framing members are formed in such a shape, the welding is performed to fix them together. As a method, spot welding or plug welding can be adopted, and such welding can be performed using a simple welding machine. In other words, the framework members can be joined by a simple welding machine without using a large-scale welding facility, and the skeleton bodies 17, 18 and thus the structure can be manufactured. For example, it is possible to install a welding machine on the side of a production line of a copying machine and efficiently assemble the skeletons 17 and 18 while performing a flow operation.

As described above, the frame members of the structure according to the present invention are joined by at least one of spot welding and plug welding, where spots where welding electrodes enter are spot welding, and where they are not, fastening is used. For example, an elongated hole may be formed in one of the frame members to be plug-welded. Any of the frame members illustrated in FIG. 2 can be easily fixed by plug welding.

The lower skeletal body 18 is formed by assembling a base member 19 in addition to a plurality of channel-shaped frame members and fixing them by welding. The sheet metal member 29 and the lower sheet metal member 30 are assembled. As described above, if the base member 19 is constituted by the sheet metal members 29 and 30, these members 29 and 30 can also be fixed by at least one of the spot welding and the plug welding. , The base member 19 can be manufactured simply and at low cost. The welding location of the two sheet metal members 29, 30 is indicated by X in FIG. 4, and in the case of FIG. 4, the two members 29, 30 are integrally fastened by spot welding and plug welding.

When each frame member is formed in a channel shape, the bending rigidity can be increased, and the rigidity of the structure can be improved.

In the structure of this embodiment, as can be seen from FIG. 2, each of the channel-shaped frame members is arranged so that the opening side of the U-shaped cross section faces the inside of the structure, and many of the members are formed. The openings are opposed to each other. For this reason, the edge of each framing member does not face outward, and even if the worker hands on the framing member of the structure when transporting the copier, the sharp edge of the framing member is not Without touching it, ensuring safety for workers.

By the way, as shown in FIGS. 1 and 6, casters 56 are attached to the base member 19 below the structure so that the copying machine can be easily moved on the floor. At this time, if the position where the substrate 57 of the caster 56 is attached to the base member 19 is low, the position of the structure is relatively high, and if the height position of the top of the copying machine is determined, The volume of the lower skeleton 18 in the vertical direction must be reduced.
Must be reduced in size, and the number of transfer papers 14 that can be stored here is reduced.

Therefore, in the structure of the present embodiment, the lower surface of the upper sheet metal member 29 of the base member 19 is used as a mounting surface of the caster 56, thereby preventing the above-described problem. The configuration related to this will be described below.

As shown in FIG. 4, the lower sheet metal member 30 of the base member 19 is formed as a recessed portion 58 having four corners inward, and as shown in FIGS. 5 and 6, these recessed portions 58 are formed. Is also covered by the upper sheet metal member 29. The substrate 57 of each caster 56 is fixed to the lower surface of the upper sheet metal member 29 corresponding to each recess 58. As described above, since the lower surface of the upper sheet metal member 29 is used as the mounting surface of the caster 56, the substrate 57 occupies a position above the lower sheet metal member 30. Therefore, the base member 19 occupies a lower position near the floor surface, and the volume in the vertical direction inside the lower skeleton 17 can be increased. As a result, a large amount of transfer paper 14 can be stored in the lower part 2 (FIG. 1) of the copying machine.

When the recessed portion 58 is formed in the lower sheet metal member 30, the hanging flange portions of the upper and lower sheet metal members 29 and 30 cannot be aligned at this portion, so that it becomes impossible to weld them. As shown in FIG.
A tongue 59 is protruded from a portion of the lower sheet metal member 30 in the vicinity of 6, and this and the upper sheet metal member 29 are welded to each other to prevent a reduction in the bonding strength between the two sheet metal members 29, 30.

In this embodiment, as shown in FIGS. 5 and 7, holes 60 are formed at the four corners of the base member 19, that is, at the portion of the base member 19 near each caster 56. Are fitted non-rotatably, and the upper male screw of the stand 62 is screwed to these nuts 61. By rotating the stand 62, the height thereof can be adjusted, and the grounding portion 63 under the stand 62 can be brought into contact with the floor to support the copying machine immovably on the floor.

In the above-described embodiment, the structure is constituted by the upper skeleton 17 and the lower skeleton 18. However, the structure may be constituted by one or three or more skeletons. At that time, in the case of a structure having one skeleton,
For example, the lower portion of the upper skeleton 17 shown in FIG. 2 may be constituted by the base member 19 instead of the frame members 31, 32, 33, 34, 35.

The present invention can be applied to structures of various image forming apparatuses other than the electronic copying machine.

[0054]

According to the first aspect of the present invention, it is possible to increase the rigidity of the entire structure and to use the structure as a common structure for many types of image forming apparatuses. . In addition, since the frame member is formed in a channel shape, it is possible to reduce the weight of the structure while obtaining high rigidity. Further, since the frame member can be fixed by spot welding or plug welding, a large-scale welding facility is not required, and the manufacturing cost of the structure can be suppressed. In addition, since the casters are attached to the upper sheet metal member of the base member, the height of the lower sheet metal member, which is the lower surface of the structure, can be reduced, and the effective volume inside the structure can be increased accordingly.

[0055]

According to the structure of the second aspect, the optical unit can be correctly positioned and assembled to the structure.

According to the third aspect of the present invention, since the opening / closing body is pivotally attached to the stiff skeleton, when the opening / closing body is opened / closed, the load and the torsional moment of the opening / closing body are elements of the image forming apparatus, for example, optical elements. The possibility of adversely affecting the unit can be eliminated.

According to the fourth aspect of the present invention, the edge of the channel-shaped frame member is not exposed to the outside, so that when the image forming apparatus is lifted or transported, sharp edges are formed in the hands of the operator. It is not possible to secure the safety for workers.

[0059]

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus to which the present invention is applied.

FIG. 2 is a perspective view showing an example of a structure.

FIG. 3 is a perspective view showing an upper skeleton body after an optical unit is assembled.

FIG. 4 is an exploded perspective view of an upper sheet metal member and a lower sheet metal member of a base member.

FIG. 5 is a plan view showing a state in which an upper sheet metal member and a lower sheet metal member are fixed to each other and attached to a caster and a stand.

6 is a sectional view taken along line VI-VI of FIG.

FIG. 7 is a sectional view taken along line VII-VII of FIG. 5;

[Explanation of symbols]

 Reference Signs List 4 optical unit 17 upper skeleton body 18 lower skeleton body 19 base member 20 skeleton member 21 skeleton member 22 skeleton member 23 skeleton member 24 skeleton member 25 skeleton member 26 skeleton member 27 skeleton member 28 skeleton member 29 upper sheet metal member 30 lower sheet metal member 31 Frame member 32 Frame member 33 Frame member 34 Frame member 35 Frame member 36 Frame member 37 Frame member 38 Frame member 39 Frame member 40 Frame member 41 Frame member 42 Frame member 43 Frame member 46 Pin 48 Pin 50 Frame member 56 Caster

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-188160 (JP, A) JP-A-54-62832 (JP, A) JP-A-62-279772 (JP, A) JP-A-54-628 JP-A-57-147657 (JP, A) JP-A-57-133040 (JP, U) JP-A-56-1442044 (JP, U) JP-A-3-47556 (JP, U) Japanese Utility Model Application No. Sho 63-152288 (JP, U) Japanese Utility Model Application No. Sho 62-5295 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 15/00 550 G03G 21/14 B41J 29 / 00-29/02

Claims (4)

(57) [Claims] 1. A base member and a plurality of channel-shaped frame members having a U-shaped cross section are assembled, and these members are fixed by at least one of spot welding and plug welding. The base member is constituted by an upper sheet metal member and a lower sheet metal member assembled together, and these sheet metal members are connected by at least one of a spot welding and a plug welding. A structure of an image forming apparatus, wherein a lower surface of a sheet metal member is a mounting surface of a caster. 2. The structure of the image forming apparatus according to claim 1, wherein an optical unit of the image forming apparatus is positioned and supported on the skeleton via at least two pins. 3. The structure of an image forming apparatus according to claim 1, wherein an opening / closing body of the image forming apparatus is pivotally mounted on an upper portion of the skeleton. 4. The structure of the image forming apparatus according to claim 1, wherein the channel-shaped frame member is arranged with its opening side facing the inside of the structure.