Sheet metal structure and method for assembling sheet metal structure

Abstract

The invention relates to a sheet metal structural body and an assembling method of the sheet metal structural body. The sheet metal structure includes a pair of first sheet metal members, a second sheet metal member, and a positioning mechanism. The second sheet metal member has a flat-plate-shaped main body part and a pair of bent parts formed by bending the two end edges of the main body part in a substantially vertical manner. The positioning mechanism has: a deep drawing part protruding inward from the inside surface of the first sheet metal member; an opening portion extending from the bent portion to the main body portion and overlapping with the draw-in portion; and a restricting part which is formed on the end edge of the opening part on the main body part side and abuts against the deep drawing part. The distance from the bent portion to the restricting portion is smaller than the protruding height of the drawing portion, the bent portion is bent and deformed in the direction approaching the first sheet metal member and comes into contact with the first sheet metal member in a state in which the drawing portion is in contact with the restricting portion, and the first sheet metal member and the bent portion are fixed at a fixed position separated from the restricting portion by a predetermined distance.

Description

Technical Field

[0001] The present invention relates to a sheet metal structure in which a plurality of sheet metal parts are mechanically joined, and an assembling method of the sheet metal structure. Background Art

[0002] A conventional image forming apparatus is a structure in which various components or devices are installed in a frame structure made of sheet metal. In addition, as a structure for improving the installation accuracy of the components or devices, a structure called a frame structure is known, wherein the frame structure includes: opposing side frames and a connecting frame connecting the side frames in a bridge-like manner. Summary of the invention 1. Technical issues to be resolved

[0003] An object of the present invention is to provide a sheet metal structure and a method for assembling the sheet metal structure, which can improve position accuracy and rigidity without requiring reinforcing parts or adjusting parts. (II) Technical solution

[0004] The sheet metal structure of the first structure of the present invention comprises: a pair of first sheet metal parts, a second sheet metal part, and a positioning mechanism arranged opposite to each other, the second sheet metal part comprises: a flat main body, and a pair of folded parts, the pair of folded parts are formed by bending the two end edges of the main body approximately vertically, overlapped with and fixed to the first sheet metal part, the second sheet metal part is connected to the pair of first sheet metal parts in a bridge shape; the positioning mechanism positions the first sheet metal part and the second sheet metal part in a direction perpendicular to the first sheet metal part, and the sheet metal structure is characterized in that the positioning mechanism has There are: a drawn portion, which protrudes inward from the inner surface of the first sheet metal component; an opening portion, which extends from the folded portion to the main body portion and overlaps with the drawn portion; and a limiting portion, which is formed at the end edge of the main body side of the opening portion and abuts against the drawn portion, and the distance from the folded portion to the limiting portion is smaller than the protruding height of the drawn portion. When the drawn portion abuts against the limiting portion, the folded portion is bent and deformed in a direction approaching the first sheet metal component and contacts the first sheet metal component. The first sheet metal component and the folded portion are fixed at a fixed position away from the limiting portion at a specified distance. In addition, the present invention is an assembly method of a sheet metal structure, the sheet metal structure having: a pair of first sheet metal parts arranged opposite to each other, and a second sheet metal part, the second sheet metal part having: a flat main body, and a pair of bent parts, the pair of bent parts being formed by bending the two end edges of the main body approximately vertically, overlapping and fixed with the first sheet metal part, the second sheet metal part being connected to the pair of first sheet metal parts in a bridge shape, with respect to the method, the first sheet metal part having a drawn part protruding inwardly from the inner surface, the second sheet metal part having: an opening extending from the bent part to the main body , and overlaps with the drawn portion; and a limiting portion, which is formed at the end edge of the main body side of the opening and abuts against the drawn portion, the method comprising: a positioning step, causing the limiting portion to abut vertically against the drawn portion to position the second sheet metal component relative to the first sheet metal component; and a fixing step, in a state in which the limiting portion abuts against the drawn portion, causing the folding portion to bend and deform in a direction close to the first sheet metal component, thereby causing the first sheet metal component to contact the folding portion, and fixing the first sheet metal component and the folding portion at a fixed position at a specified distance from the limiting portion. (III) Beneficial effects

[0005] According to the first structure of the present invention, by making the limiting portion formed on the bending portion abut against the drawn portion of the first sheet metal component, the first sheet metal component is less likely to deform compared to a structure in which the limiting portion abuts against the flat portion of the first sheet metal component. Therefore, the rigidity of the connecting portion between the first sheet metal component and the second sheet metal component can be ensured, and there is no need to provide a reinforcing component in the connecting portion. In addition, a gap is formed between the first sheet metal component and the bending portion, so that the angular tolerance (deviation) of the bending portion can be absorbed, so that the first sheet metal component and the second sheet metal component can be positioned with high precision. According to the second structure of the present invention, the sheet metal structure can be assembled by accurately positioning the pair of first sheet metal members disposed opposite to each other and the second sheet metal member connected to the pair of first sheet metal members in a bridge shape. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 1 is a schematic cross-sectional view of an image forming apparatus 100 including a main body frame 101 according to an embodiment of the present invention. Figure 2 It is a perspective view of the main frame 101. Figure 3 This is a side view of the periphery of the positioning mechanism 120 of the side frame 102 and the first connecting frame 103 as viewed from the inner side of the side frame 102 . Figure 4 This is a plan view of the periphery of the positioning mechanism 120 as viewed from above. Figure 5 This is a side view of the periphery of the positioning mechanism 120 as viewed from the second connecting frame 104 side. Figure 6 is a vertical cross-sectional view of the positioning mechanism 120 . Figure 7 1 is a horizontal cross-sectional view of the positioning mechanism 120 . Figure 8 This is a side view of the periphery of the positioning mechanism 120 as viewed from the second connecting frame 104 side, and shows a state in which the side frame 102 and the folding portion 110 are fixed. DETAILED DESCRIPTION

[0007] Embodiments of the present invention will be described below with reference to the accompanying drawings. Figure 1 1 is a schematic diagram showing the structure of an image forming apparatus 100 including a main body frame 101 according to an embodiment of the present invention.

[0008] Figure 1 The image forming apparatus 100 shown is a so-called tandem color printer and has the following structure. Figure 1 The left side in the middle is provided with four image forming units Pa, Pb, Pc, and Pd in ​​sequence. These image forming units Pa to Pd correspond to different four-color (yellow, cyan, magenta, and black) image settings, and form yellow, cyan, magenta, and black images in sequence through charging, exposure, development, and transfer processes, respectively.

[0009] The image forming sections Pa to Pd are provided with photosensitive drums 1a, 1b, 1c, and 1d that carry visible images (toner images) of respective colors. In addition, an intermediate transfer belt 8 is provided adjacent to each of the image forming sections Pa to Pd. Figure 1 The toner images formed on the photosensitive drums 1a to 1d are sequentially transferred to an intermediate transfer belt 8 that moves in contact with the photosensitive drums 1a to 1d, and then are collectively transferred to a sheet S as an example of a recording medium by a secondary transfer roller 9.

[0010] The paper S to which the toner image has been transferred is stored in a paper cassette 16 at a lower portion of the main body of the image forming apparatus 100 , and is conveyed to the secondary transfer roller 9 via a paper feed roller 12 a and a pair of registration rollers 12 b .

[0011] Next, the image forming process in the image forming apparatus 100 is described. When the user inputs an instruction to start image formation, first, the photosensitive drums 1a to 1d start rotating by a main motor (not shown), and the surfaces of the photosensitive drums 1a to 1d are uniformly charged by the charging devices 2a to 2d. Then, the surfaces of the photosensitive drums 1a to 1d are irradiated with light by a light beam (laser) emitted from the exposure device 5, and an electrostatic latent image corresponding to the image signal is formed on each of the photosensitive drums 1a to 1d.

[0012] The developing devices 3a to 3d are filled with a predetermined amount of two-component developer containing toners of yellow, cyan, magenta and black, respectively. The toner in the developer is supplied to the photosensitive drums 1a to 1d by the developing devices 3a to 3d and electrostatically adheres to the photosensitive drums 1a to 1d, thereby developing the electrostatic latent image into a toner image. In addition, when the ratio of the toner in the two-component developer filled in each developing device 3a to 3d is lower than a predetermined value, the toner is replenished from the toner container 4a to 4d to each developing device 3a to 3d.

[0013] Then, the primary transfer rollers 6a to 6d are used to apply an electric field between the primary transfer rollers 6a to 6d and the photosensitive drums 1a to 1d at a predetermined transfer voltage, and the yellow, cyan, magenta, and black toner images on the photosensitive drums 1a to 1d are primarily transferred to the intermediate transfer belt 8. These four-color images are formed in a predetermined positional relationship to form a predetermined full-color image. After that, in preparation for the subsequent formation of a new electrostatic latent image, the toner remaining on the surface of the photosensitive drums 1a to 1d is removed by the cleaning devices 7a to 7d.

[0014] The driving roller 10 is rotated by a belt driving motor (not shown). When the intermediate transfer belt 8 starts to rotate counterclockwise with the rotation of the driving roller 10, the paper S is conveyed from the registration roller pair 12b to the secondary transfer roller 9 provided adjacent to the intermediate transfer belt 8 at a predetermined timing, and a full-color image is transferred. The paper S to which the toner image is transferred is conveyed to the fixing unit 13. The toner remaining on the surface of the intermediate transfer belt 8 is removed by the belt cleaning unit 19.

[0015] The fixing roller pair 13a heats and pressurizes the paper S conveyed to the fixing section 13, and fixes the toner image on the surface of the paper S to form a predetermined full-color image. The paper S with the full-color image formed thereon is assigned a conveying direction by the branching section 14 that branches in multiple directions, and is discharged to the discharge tray 17 directly (or after being conveyed to the double-sided conveying path 18 and double-sided printing is performed) by the discharge roller pair 15.

[0016] Figure 2 It is a perspective view of a main body frame 101 constituting the image forming apparatus 100 . The main body frame 101 includes a pair of side frames 102 , a first connecting frame 103 , a second connecting frame 104 , and a third connecting frame 105 .

[0017] The side frame 102 is formed on the front surface side of the image forming apparatus 100 ( Figure 1 The front side of the paper) and the back side ( Figure 1 The first connecting frame 103, the second connecting frame 104, and the third connecting frame 105 are sheet metal components (second sheet metal components) that are arranged opposite to each other on the paper depth side. The first connecting frame 103, the second connecting frame 104, and the third connecting frame 105 are sheet metal components (second sheet metal components) that are connected in a bridge shape between the pair of side frames 102.

[0018] The first to third connection frames 103 to 105 include a flat main body 109 and a pair of bent portions 110 formed by bending both ends of the main body 109 in the longitudinal direction substantially perpendicularly. Figure 2 Only one end side of the first connecting frame 103 and the second connecting frame 104 is shown. Figure 2 The bending portion 110 of the third connecting frame 105 is bent downward, so that Figure 2 Not shown.

[0019] The bent portions 110 of the first to third connecting frames 103 to 105 are fixed to the inner surfaces of the pair of side frames 102 , respectively, so that the first to third connecting frames 103 to 105 are connected in a bridge-like manner between the pair of side frames 102 .

[0020] A positioning mechanism 120 is provided at the connection portion between the side frame 102 and the first to third connection frames 103 to 105. The positioning mechanism 120 positions the first to third connection frames 103 to 105 in the longitudinal direction (direction perpendicular to the side frame 102).

[0021] Furthermore, the first to third connecting frames 103 to 105 are positioned relative to the side frame 102 in the plane direction by fitting positioning protrusions formed on the side frame 102 and positioning holes (neither shown) formed on the bent portion 110 .

[0022] Next, the detailed structure of the positioning mechanism 120 will be described. In the following description, the side frame 102 and the one end side of the first connecting frame 103 ( Figure 2 The positioning mechanism 120 of the side frame 102 and the other end side of the first connecting frame 103 ( Figure 2 The positioning mechanism 120 of the left side of the frame 102 and the positioning mechanism 120 of the side frame 102 and the second connecting frame 104 and the third connecting frame 105 are all of the same structure.

[0023] Figure 3The periphery of the positioning mechanism 120 of the side frame 102 and the first connecting frame 103 is viewed from the inner side of the side frame 102 ( Figure 2 side view of the device (within the dotted circle). Figure 4 This is a plan view of the periphery of the positioning mechanism 120 as viewed from above. Figure 5 From the second connecting frame 104 side ( Figure 2 A side view of the periphery of the positioning mechanism 120 observed from the lower left direction). Figure 6 and Figure 7 They are vertical cross-sectional views of the positioning mechanism 120 ( Figure 3 AA section view) and horizontal section view ( Figure 5 In addition, Figure 3 to Figure 7 The side frame 102 and the first connecting frame 103 are shown in a state where they are positioned, but the side frame 102 and the first connecting frame 103 are not fixed.

[0024] like Figure 3 to Figure 7 As shown, the positioning mechanism 120 includes a drawn portion 121, an opening 122, and a restricting portion 123. The drawn portion 121 protrudes inward from the inner surface of the side frame 102 and is trapezoidal in side view. The drawn portion 121 is formed by drawing the side frame 102.

[0025] The opening 122 extends from the main body 109 of the first connecting frame 103 across the bent portion 110a to the bent portion 110. The opening 122 is arranged to overlap with the drawn portion 121. The opening 122 has a first region 122a formed on the main body 109 and a second region 122b formed on the bent portion 110. The limiting portion 123 is formed at the end edge of the opening 122 on the main body 109 side (first region 122a).

[0026] like Figure 3 As shown, the opening width w1 of the opening 122 is larger than the width w2 of the drawn portion 121 . Therefore, when the opening 122 is arranged to overlap with the drawn portion 121 , the peripheral edge of the opening 122 (second region 122 b ) does not contact the drawn portion 121 .

[0027] like Figure 7 As shown in FIG. 1 , the depth h1 of the first region 122a of the opening 122 (the distance from the bent portion 110 to the limiting portion 123) is smaller than the height h2 of the drawn portion 121. Therefore, when the opening 122 is arranged to overlap with the drawn portion 121, the limiting portion 123 abuts against the drawn portion 121. Figures 4 to 7 As shown, a gap d is formed between the side frame 102 and the bent portion 110. The gap d is equivalent to the difference h2 between h2 and h1. ― h1.

[0028] Figure 8 1 is a side view showing a state where the side frame 102 and the folding portion 110 are fixed. Figure 8 As shown, when the side frame 102 and the folded portion 110 are fixed at the fixing position P above the positioning mechanism 120 , the gap d disappears due to the folded portion 110 bending toward the side frame 102 , and the side frame 102 and the folded portion 110 come into surface contact.

[0029] There is no particular limitation on the fixing method at the fixing position P, and known existing methods such as screw fixing, spot welding, and riveting can be used. As the riveting fixing method, the Stokes (registered trademark) riveting method is preferred, that is, two metal plates are sandwiched and compressed using a convex and concave mold, and the metal plate on the convex side protrudes outward along the groove provided on the circumference of the concave bottom surface, thereby fixing the two metal plates together.

[0030] In this embodiment, the side frame 102 is provided with the drawn portion 121 , and the restricting portion 123 of the opening 122 abuts against the drawn portion 122 , thereby positioning the first connecting frame 103 in the longitudinal direction (direction perpendicular to the side frame 102 ).

[0031] Thus, when the limiting portion 123 is pressed against the side frame 102 by the pressure when the side frame 102 and the folding portion 110 are fixed, the side frame 102 is less likely to be deformed compared to a structure in which the limiting portion 123 abuts against the flat portion of the side frame 102. Therefore, the rigidity of the connection portion between the side frame 102 and the first connection frame 103 can be ensured, and it is not necessary to provide a reinforcing member at the connection portion. In addition, when the exposure device 5, the intermediate transfer unit, etc. are installed, it is not necessary to perform position adjustment work using an adjustment member.

[0032] In addition, since a gap d is formed between the side frame 102 and the bent portion 110, the angular tolerance (deviation) of the bent portion 110 can be absorbed, and the side frame 102 and the first connecting frame 103 can be positioned with high accuracy. The gap d between the side frame 102 and the bent portion 110 can be appropriately set according to the size of the bent portion 110 and the protrusion amount of the drawn portion 121.

[0033] In addition, when the distance between the drawn portion 121 and the fixing position P is short, the bending amount of the bending portion 110 when fixing the bending portion 110 to the side plate frame 102 is large, so it is necessary to increase the pressing force of the bending portion 110 on the side frame 102. As a result, there is a possibility that the working efficiency is reduced or the side frame 102 is deformed.

[0034] Therefore, in the present embodiment, the fixed position P is offset from the drawn portion 121 so that the drawn portion 121 and the fixed position P are separated from each other by a predetermined distance or more. Figure 7As shown, the distance x between the drawn portion 121 and the fixed position P closest to the drawn portion 121 is greater than a certain distance. The distance x can be appropriately set according to the size of the bent portion 110 and the gap d between the side frame 102 and the bent portion 110.

[0035] In addition, the present invention is not limited to the above-mentioned embodiment, and various changes can be made without departing from the scope of the present invention. For example, although in the above-mentioned embodiment, the positioning mechanism 120 of the side frame 102 and the first connecting frame 103 to the third connecting frame 105 constituting the main frame 101 of the image forming device 100 is described, it is of course also applicable to the frames of other electronic devices other than the image forming device.

Claims

1. A sheet metal structure comprising: a pair of first sheet metal components, a second sheet metal component, and a positioning mechanism arranged opposite to each other, The second sheet metal component has a flat plate-shaped main body and a pair of bent portions. The pair of bent portions are formed by vertically bending both end edges of the main body, overlapped with and fixed to the first sheet metal component, The second sheet metal component is connected to the pair of first sheet metal components in a bridge shape. The positioning mechanism positions the first sheet metal component and the second sheet metal component in a direction perpendicular to the first sheet metal component. The sheet metal structure is characterized in that The positioning mechanism has: a drawn portion protruding inwardly from an inner surface of the first sheet metal component; An opening portion extending from the bent portion to the main body portion and overlapping with the drawn portion; and a restricting portion formed at an end edge of the opening on the main body side and abutting against the drawn portion, The distance from the bending portion to the limiting portion is smaller than the protruding height of the drawn portion. When the drawn portion is in contact with the limiting portion, the bending portion is bent and deformed in a direction approaching the first sheet metal component and contacts the first sheet metal component. The first sheet metal component and the bending portion are fixed at a fixed position at a specified distance from the limiting portion.

2. The sheet metal structure according to claim 1, characterized in that: The first sheet metal component and the folded portion are fixed at the fixed position by any one of screw fixing, welding and riveting.

3. The sheet metal structure according to claim 2, characterized in that: It is the main frame of the image forming device, including: a pair of side frames disposed opposite to each other with a predetermined interval therebetween as the first sheet metal member; and One or more connecting frames are connected between the pair of side frames in a bridge shape and serve as the second sheet metal member.

4. A method for assembling a sheet metal structure, The sheet metal structure comprises: a pair of first sheet metal parts arranged opposite to each other, and a second sheet metal part, the second sheet metal part comprises: a flat main body part, and a pair of bent parts, the pair of bent parts are formed by vertically bending the two end edges of the main body part, overlapped with and fixed to the first sheet metal part, and the second sheet metal part is connected to the pair of first sheet metal parts in a bridge shape, The method is characterized in that The first sheet metal component has a drawn portion protruding inward from the inner surface, The second sheet metal component has: An opening portion extending from the bent portion to the main body portion and overlapping with the drawn portion; and a restricting portion formed at an end edge of the opening on the main body side and abutting against the drawn portion, The method has: a positioning step of positioning the second sheet metal component relative to the first sheet metal component by making the limiting portion vertically abut against the drawing portion; and In a fixing process, when the limiting portion is in contact with the drawn portion, the bending portion is bent and deformed in a direction approaching the first sheet metal component, thereby making the first sheet metal component contact with the bending portion, and fixing the first sheet metal component and the bending portion at a fixed position away from the limiting portion at a specified distance.

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