JP2024093090A - Manufacturing method of structure, structure - Google Patents

Abstract

To weld a plurality of square pipes with high positional accuracy.
[Solution] Each of the square pipes 60 has three first corners 63a, one second corner 63b, two first side surfaces 62a, two second side surfaces 62b, and a plurality of positioning holes 66a. The second corners 63b include two edges 64 and a welded portion 65 of a metal plate. The two first side surfaces 62a are formed between two of the three first corners 63a. The plurality of positioning holes 66a are formed in one or both of the two first side surfaces 62a. The manufacturing method of the structure 6 includes positioning the plurality of target pipes 60a, 60b by inserting a plurality of protrusions 71, 72 of a jig 7 into the plurality of positioning holes 66a of the plurality of target pipes 60a, 60b. The manufacturing method further includes joining the plurality of target pipes 60a, 60b positioned by the jig 7 by welding.
[Selected figure] Figure 3

Description

The present invention relates to a method for manufacturing a structure made up of multiple joined square pipes, and a structure manufactured by this manufacturing method.

The image forming device includes a paper feed unit, a printing unit, a developer container, and a structure that houses and supports the paper feed unit, the printing unit, and the developer container.

For example, it is known that the structure is made of multiple square pipes joined by welding (see, for example, Patent Document 1). Such a structure has high strength.

JP 2000-138470 A

However, it is desirable to weld the multiple square pipes in the structure with high positional accuracy.

The object of the present invention is to provide a manufacturing method and structure that can weld multiple square pipes with high positional accuracy.

A method for manufacturing a structure according to one aspect of the present invention is a method for manufacturing a structure composed of a plurality of joined square pipes. The manufacturing method is applied when each of the plurality of square pipes has three first corners, one second corner, two first side surfaces, two second side surfaces, and a plurality of positioning holes. The three first corners are formed by bending a single metal plate. The one second corner includes two edge portions of the metal plate and a weld portion that joins the two edge portions. The two first side surfaces are formed between two of the three first corners. The two second side surfaces are formed between one of the three first corners and the second corner. The plurality of positioning holes are formed in one or both of the two first side surfaces. The manufacturing method includes preparing a positioning jig on which a plurality of protrusions are formed. The manufacturing method further includes positioning the plurality of target pipes by inserting the plurality of protrusions into the plurality of positioning holes of a plurality of target pipes that are part or all of the plurality of square pipes. The manufacturing method further includes joining the multiple target pipes positioned by the jig by welding.

The structure according to another aspect of the present invention is manufactured by the above-mentioned manufacturing method.

The present invention makes it possible to provide a manufacturing method and structure that can weld multiple square pipes with high positional accuracy.

FIG. 1 is a diagram showing the configuration of an image forming apparatus including a structure according to an embodiment. FIG. 2 is a perspective view of the structure according to the embodiment. FIG. 3 is a perspective view of one of the square pipes in the structure according to the embodiment. FIG. 4 is a perspective view of two joined square pipes in a structure according to the embodiment. FIG. 5 is a diagram showing an example of a joining form including a specific welded portion in a structure according to an embodiment. FIG. 6 is a diagram showing a specific welded portion in a structure according to an embodiment. FIG. 7 is a flowchart showing the steps of a method for manufacturing a structure according to the embodiment. FIG. 8 is a diagram illustrating a square pipe positioning step in the manufacturing method of the structure according to the embodiment. FIG. 9 is a perspective view of two square pipes positioned by the square pipe positioning step in the manufacturing method of the structure according to the embodiment.

Below, an embodiment of the present invention will be described with reference to the drawings. Note that the following embodiment is an example of the present invention and does not limit the technical scope of the present invention.

[Configuration of Image Forming Apparatus 10]
A structure 6 according to the embodiment is employed in an image forming apparatus 10. As shown in FIG.

The main unit 1 includes a paper feed section 30, a paper transport device 3, a print section 4, one or more developer containers 5, and a structure 6. The image reading unit 2 is connected to the top of the main unit 1. The image reading unit 2 is a device that reads an image of a document.

The paper feed unit 30 is a device that stores multiple sheets of paper and sends the stored sheets one by one to the paper transport path 300. The paper transport device 3 has multiple pairs of transport rollers 31 that transport the sheets along the paper transport path 300.

The printing unit 4 is a device that forms an image on the paper supplied from the paper feed unit 30 through the paper transport device 3. In the example shown in FIG. 1, the printing unit 4 forms an image on the paper using an electrophotographic method.

The electrophotographic printing section 4 includes a laser scanning unit 40, one or more image forming sections 4x, a transfer device 44, and a fixing device 45.

In the example shown in FIG. 1, the printing unit 4 is a tandem-type color image printing device. Therefore, the printing unit 4 has four image forming units 4x corresponding to the four colors of toner. Furthermore, the image forming device 10 has four developer containers 5 corresponding to the four image forming units 4x.

In each image forming section 4x, a drum-shaped photoconductor 41 rotates, a charging device 42 charges the outer surface of the photoconductor 41, a laser scanning unit 40 writes an electrostatic latent image onto the outer surface of the photoconductor 41, and a developing device 43 develops the electrostatic latent image into a toner image.

Furthermore, in the transfer device 44, the intermediate transfer belt 440 rotates while contacting the four photoconductors 41, and the four primary transfer devices 441 corresponding to the four image forming units 4x transfer the toner image onto the intermediate transfer belt 440, and the secondary transfer device 442 transfers the toner image on the intermediate transfer belt 440 onto the paper being transported along the paper transport path 300.

The fixing device 45 fixes the toner image on the paper by applying heat and pressure to the paper. The paper transport device 3 ejects the paper on which the image has been formed from the paper transport path 300.

Each developer container 5 supplies toner to a corresponding developing device 43 in the printing unit 4. The toner is an example of a developer. Note that the printing unit 4 may be a device that forms an image on the paper using an inkjet method or another method.

The paper feed section 30, the paper transport device 3, the print section 4 and the developer container 5 are attached to the structure 6. The image reading unit 2 is connected to the upper part of the structure 6.

The structure 6 is composed of multiple square pipes 60 joined by welding (see Figure 2). In other words, the structure 6 is a single member in which multiple metal square pipes 60 are connected by welding. Such a structure 6 has high strength. Note that metal panels may also be joined to the structure 6 by welding.

However, it is desirable to weld multiple square pipes 60 in the structure 6 with high positional accuracy.

The following describes the configuration of the structure 6 for welding multiple square pipes 60 with high positional accuracy and the manufacturing method of the structure 6.

[Structure of each square pipe 60]
Each of the plurality of square pipes 60 has four side surfaces 62 and four corners 63 (see FIG. 3). The four side surfaces 62 and the four corners 63 are formed to extend in the longitudinal direction of each square pipe 60.

The four corners 63 include three first corners 63a and one second corner 63b. The three first corners 63a are three bent portions formed by bending a single metal plate. The second corner 63b includes two edge portions 64 of the metal plate and a weld portion 65 that joins the two edge portions 64.

The two edges 64 and the welds 65 are formed extending in the longitudinal direction of each square pipe 60.

Each square pipe 60 has a plurality of through holes 66 formed in one or more of the four side surfaces 62 (see Figures 3 and 4). The processing of the plurality of through holes 66 in the plurality of square pipes 60 is performed on the flat metal plate before bending processing is performed.

Some or all of the multiple through holes 66 are used to attach parts. For example, the parts are attached directly to one of the side surfaces 62 of each of the square pipes 60 by fastening members such as bolts or screws inserted into the through holes 66.

In this embodiment, the image reading unit 2, the paper transport device 3, and the printing unit 4 are attached to the structure 6 by the fixing members inserted into the through holes 66.

It is possible that two or more of the multiple square pipes 60 are the same type of components in order to standardize parts. In this case, some of the multiple through holes 66 in some of the multiple square pipes 60 of the same type may not be used for attaching parts.

In each of the square pipes 60, none of the four side surfaces 62 includes a weld 65. Therefore, it is easy to form one or more through holes 66 in each of the four side surfaces 62 in each of the square pipes 60.

For example, four or more through holes 66 are formed on the four side surfaces 62 of at least one of the multiple square pipes 60 (see Figure 3).

In each square pipe 60, the four sides 62 include two first sides 62a and two second sides 62b (see Figure 3).

The first side 62a is a surface formed between two of the three first corners 63a. On the other hand, the second side 62b is a surface adjacent to the second corners 63b. Each of the first side surfaces 62a is formed with greater precision than each of the second side surfaces 62b.

In this embodiment, the multiple through holes 66 include multiple positioning holes 66a. The positioning holes 66a are holes into which multiple protrusions 71, 72 of the positioning jig 7 are fitted when the multiple square pipes 60 are joined by welding (see Figures 8 and 9).

The multiple protrusions 71, 72 of the jig 7 are fitted into the positioning holes 66a of the multiple square pipes 60, so that the multiple square pipes 60 are positioned with high precision. The positioning holes 66a may also serve as holes for mounting parts.

By using square pipes 60 as shown in Figure 3 in the structure 6, all four sides 62 of each square pipe 60 can be used to attach parts.

In this embodiment, the three first corners 63a are chamfered (see FIG. 3). In addition, at the second corner 63b, the two edges 64 of the metal plate are bent to form a chamfered shape.

In each of the square pipes 60, the welds 65 may be formed so as to slightly protrude from the gap between the two edges 64. Even in such cases, because the two edges 64 form a chamfered shape, the welds 65 do not interfere with the parts attached to each of the second side surfaces 62b.

[Structure 6]
The structure 6 has one or more specific welds 600x, which are welded portions between one side surface 62 of the first pipe 60a and one end of the second pipe 60b (see FIGS. 2, 4 to 6). The first pipe 60a and the second pipe 60b are part of the plurality of square pipes 60 in the structure 6.

Figure 4 is a perspective view of a first pipe 60a and a second pipe 60b joined by a specific weld 600x. Figure 5 is a plan view of one first pipe 60a and two second pipes 60b joined by a specific weld 600x. Figure 6 is a front view of the specific weld 600x.

In Figures 4 to 6, the first direction D1 is the longitudinal direction of the first pipe 60a, and the second direction D2 is the longitudinal direction of the second pipe 60b. The second direction D2 is a direction that intersects with the first direction D1. The third direction D3 is a direction that intersects with the first direction D1 and the second direction D2.

In this embodiment, the second direction D2 is perpendicular to the first direction D1, and the third direction D3 is perpendicular to the first direction D1 and the second direction D2.

At the specific weld 600x, one of the two second side surfaces 62b may be welded to one end of the second pipe 60b. In this case, because the two edges 64 form a chamfered shape, the weld 65 of the first pipe 60a does not interfere with the end surface 61 of the second pipe 60b.

The specific welded portion 600x includes a pair of strip welded portions 600 (see FIG. 6). A pair of specific edges 61x along the third direction D3 among the four edges of the end face 61 of the second pipe 60b are joined to one of the side faces 62 of the first pipe 60a by the pair of strip welded portions 600 (see FIG. 6).

Each of the pair of strip welds 600 is a fused portion of a first pipe 60a and a portion of a second pipe 60b.

Of the four sides that make up the end face 61 of the second pipe 60b, the remaining two sides are non-jointed sides that are not welded to the first pipe 60a. It is also possible that three of the four sides that make up the end face 61 of the second pipe 60b are specific sides 61x, and the remaining side is the non-jointed side.

For example, the non-jointed side faces one of the side surfaces 62 of the first pipe 60a across a gap 6000 (see FIG. 4). In this case, a pair of specific sides 61x are welded to one of the side surfaces 62 of the second pipe 60b with the end face 61 of the second pipe 60b facing one of the side surfaces 62 of the first pipe 60a across a gap 6000.

Therefore, variation in the dimensions of the end face 61 of the second pipe 60b does not affect the positional relationship between the first pipe 60a and the second pipe 60b in the structure 6.

[Method of Manufacturing Structure 6]
Next, the steps of the method for manufacturing the structure 6 will be described with reference to the flow chart shown in FIG.

In the following description, S1, S2, ... represent identification symbols for multiple steps in the manufacturing method of structure 6.

<Step S1>
First, in step S1, a jig 7 used for positioning a plurality of square pipes 60 is prepared (see FIGS. 7 and 8).

The jig 7 has two first protrusions 71 corresponding to the first pipe 60a and two second protrusions 72 corresponding to the second pipe 60b.

On the other hand, the first pipe 60a has two positioning holes 66a into which the two first protrusions 71 of the jig 7 are inserted. In this embodiment, the two positioning holes 66a corresponding to the two first protrusions 71 are formed in one or both of the two first side surfaces 62a of the first pipe 60a.

Similarly, the second pipe 60b has two positioning holes 66a into which the two second protrusions 72 of the jig 7 are inserted. In this embodiment, the two positioning holes 66a corresponding to the two second protrusions 72 are formed in one or both of the two first side surfaces 62a of the second pipe 60b.

<Step S2>
Next, in step S2, the two first convex portions 71 and the two second convex portions 72 of the jig 7 are inserted into the two positioning holes 66a of the first pipe 60a and the two positioning holes 66a of the second pipe 60b (see Figures 8 and 9).

The first and second protrusions 71 and 72 are inserted into the positioning holes 66a of the first and second pipes 60a and 60b, respectively, so that the first and second pipes 60a and 60b are positioned in a predetermined positional relationship (see FIG. 9).

In this embodiment, the multiple positioning holes 66a are formed in one or both of the two first side surfaces 62a of the first pipe 60a and the second pipe 60b. As described above, each of the first side surfaces 62a is formed with greater precision than each of the second side surfaces 62b.

Therefore, in step S2, the first pipe 60a and the second pipe 60b are positioned with greater precision.

In this embodiment, one of the two positioning holes 66a in the first pipe 60a is a circular hole, and the other is an elongated hole that runs along the longitudinal direction of the first pipe 60a. Similarly, one of the two positioning holes 66a in the second pipe 60b is a circular hole, and the other is an elongated hole that runs along the longitudinal direction of the second pipe 60b.

The first pipe 60a is positioned in its longitudinal direction by fitting one of the two first protrusions 71 into the circular positioning hole 66a. The first pipe 60a is positioned in its lateral direction by inserting the other of the two first protrusions 71 into the long positioning hole 66a.

Similarly, the second pipe 60b is positioned in its longitudinal direction by fitting one of the two second protrusions 72 into the circular positioning hole 66a. The second pipe 60b is positioned in its lateral direction by inserting the other of the two second protrusions 72 into the long positioning hole 66a.

In step S2, the first pipe 60a and the second pipe 60b are positioned in a predetermined positional relationship with the end face 61 of the second pipe 60b facing the first side face 62a of the first pipe 60a across a gap 6000.

Note that step S2 is an example of a step of positioning the first pipe 60a and the second pipe 60b. The first pipe 60a and the second pipe 60b are also an example of a plurality of target pipes. The plurality of target pipes are some or all of the plurality of square pipes 60 that constitute the structure 6.

<Step S3>
Next, in step S3, only two of the four sides constituting the end face 61 of the second pipe 60b are joined by welding to one of the two first side faces 62a of the first pipe 60a.

Step S3 is performed with the first pipe 60a and the second pipe 60b positioned by the jig 7. Step S3 is a step of forming a pair of strip welds 600 at the specific weld 600x.

In addition, in step S3, it is also possible that only three of the four sides constituting the end face 61 of the second pipe 60b are joined by welding to one of the first side faces 62a of the first pipe 60a.

As shown in steps S2 and S3, the first pipe 60a and the second pipe 60b are welded with the protrusions 71 and 72 of the jig 7 inserted into the corresponding positioning holes 66a.

<Step S4>
Next, in step S4, post-processing such as deburring of the pair of strip welds 600 is performed. This completes the manufacture of the structure 6.

In addition, in step S2, three or more square pipes 60 may be positioned by one jig 7, and in step S3, three or more square pipes 60 may be welded.

In addition, steps S2 and S3 are performed once or multiple times in the manufacturing process of structure 6.

By manufacturing the structure 6 using the manufacturing method described above, multiple square pipes 60 are welded with high positional accuracy.

1: Main unit 2: Image reading unit 4: Printing section 6: Structure 7: Jig 10: Image forming device 60: Square pipe 60a: First pipe 60b: Second pipe 61: End face 61x: Specific side 62: Side 62a: First side 62b: Second side 63: Corner 63a: First corner 63b: Second corner 64: Edge 65: Welded section 66: Through hole 66a: Positioning hole 71: First protruding section 72: Second protruding section 600x: Specific welded section 6000: Gap

Claims (5)

A method for manufacturing a structure composed of a plurality of joined square pipes, comprising the steps of:
Each of the plurality of square pipes is
Three first corner portions formed by bending a single metal plate;
a second corner portion including two edges of the metal plate and a weld portion joining the two edges;
two first side surfaces each formed between two of the three first corners;
two second side surfaces each formed between one of the three first corners and the second corner;
and a plurality of positioning holes formed in one or both of the two first side surfaces,
preparing a positioning jig having a plurality of protrusions;
positioning the plurality of target pipes by inserting the plurality of protrusions into the plurality of positioning holes of a plurality of target pipes which are a part or all of the plurality of square pipes;
and joining the plurality of target pipes positioned by the jig by welding. positioning the plurality of target pipes includes inserting the plurality of protrusions into the plurality of positioning holes to position an end face of a first pipe, which is one of the plurality of target pipes, facing one of the two second side faces of a second pipe, which is another of the plurality of target pipes, across a gap;
The method for manufacturing a structure described in claim 1, wherein joining the multiple target pipes by welding includes welding only two or three of the four sides forming the end face of the first pipe to one of the two second side faces of the second pipe. Each of the plurality of protrusions has a circular cross section,
The method for manufacturing a structure according to claim 1 or 2, wherein the plurality of positioning holes include a circular hole and an elongated hole extending along a longitudinal direction of each of the plurality of target pipes. The structure according to claim 1 or 2, wherein the two edges of the metal plate in each of the plurality of square pipes are bent to form a chamfered shape. A structure manufactured by the manufacturing method described in claim 1 or claim 2.