JP4401595B2 - Pipe body and image forming apparatus using the pipe body - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pipe body having a polygonal cross section manufactured by bending a metal plate, and an image forming apparatus using the pipe body.
[0002]
[Prior art]
As a technique for manufacturing a pipe body having a polygonal cross section by bending a metal plate, the applicant has already proposed in Japanese Patent Application No. 2000-388916. In the technique described in Japanese Patent Application No. 2000-388916 and the like, by applying a springback force to the pipe body, the edges (a pair of sides) of the metal plate are brought into close contact with each other, and welding work for the joint portion is unnecessary. It is said.
[0003]
[Problems to be solved by the invention]
By the way, a mold is usually used for manufacturing the pipe body, but since the lubricant is applied to the mold to prevent its wear, the lubricant is almost entirely attached to the pipe body immediately after completion. is doing. The adhering lubricating oil may be cleaned in the subsequent cleaning process, but in recent years, from the viewpoint of work efficiency etc., use a quick-drying lubricating oil and leave the finished pipe body in the air. The lubricating oil adhering to this may be volatilized and the cleaning process may be omitted.
[0004]
However, for example, when a pipe body 80 having a rectangular cross section as shown in FIG. 44 is manufactured, the pipe body 80 has a spring back force acting surface 81 on which a spring back force acts (the bottom constituting wall portion in Japanese Patent Application No. 2000-388916). 2) and the like, and the like are lined up in the component storage box 83 with the joint surface 82 (corresponding to the upper surface constituting wall portion 5 in the same application) facing upward. (FIG. 45), since the side surfaces 84 of the pipe bodies 80 adjacent to each other are in close contact with each other at this time, the lubricating oil (indicated by symbol L in FIG. 45) adhering to the front side of the side surface 84 is quick-drying. There is a possibility that the air will not be volatilized until the next process without touching the air (note that the lubricating oil adhering to the front side of the spring back force acting surface 81 It is absorbed Lumpur plate 85.).
[0005]
Then, when an operator in the next process handles the pipe body 80, there is a risk that the lubricant will adhere to his hand, making it difficult to work, or that the assembly robot in the next process will not be able to assemble the pipe body 80 well. In addition, for example, when the pipe body 80 is used by being incorporated in the image forming apparatus, there is a possibility that dust adheres to the pipe body 80 through the lubricating oil. There is a risk that the electronic components and other functional parts may be disturbed by flying in the air current.
[0006]
On the other hand, in order to avoid such a situation, it is necessary to wash the pipe body 80 or to wait for the packaging etc. until the lubricating oil dries after completion. Therefore, the processing efficiency of the pipe body 80 that can be efficiently manufactured is deteriorated, and the cost is increased.
[0007]
The present invention has been made in view of the above circumstances, and a pipe body that can be manufactured at low cost using a quick-drying lubricating oil and is easy to handle after completion, and this pipe body are used. It is an object of the present invention to provide an image forming apparatus.
[0008]
[Means for Solving the Problems]
  In order to solve the above-mentioned problem, the invention according to claim 1 is configured to bend a metal plate having a pair of sides parallel to each other at a plurality of locations along a straight line parallel to the pair of sides and join the pair of sides to each other. The cross-section manufactured by making the pipe body has a polygonal shape and includes a joint portion between the pair of sides among the surfaces corresponding to the sides of the polygon, and other than the joint surface When a surface is a remaining surface, the surface has one constituent wall portion corresponding to one of the remaining surfaces and an adjacent constituent wall portion corresponding to a surface adjacent to the one surface. A processing step for forming an intermediate molded product having an angle larger than a corresponding angle of the polygon and the pair of sides being in a non-contact state; and applying the external force to the adjacent constituent wall portion and the one constituent wall Forms a curved surface that bulges outward In addition, a processing step for bringing the pair of sides into close contact with each other and a processing step for deforming the curved surface into a flat shape by applying an external force to the one constituent wall portion in a state where the pair of sides are brought into close contact with each other. The pair of sides are in close contact with each other on the basis of a springback force that attempts to return to the original curved surface in which the flatly deformed portion bulges outward and either of the polygons The surface corresponding to this side is provided with a protrusion for preventing close contact with another pipe body.
  Claim 2According to the present invention, a metal plate having a pair of sides parallel to each other is bent at a plurality of locations along a straight line parallel to the pair of sides, and the cross section manufactured by joining the pair of sides is rectangular. A pipe body that includes a joint portion of the pair of sides among the surfaces corresponding to the sides of the rectangle as a joint surface, and a surface other than the joint surface as a remaining surface,One of the remaining surfaces corresponding to one surface facing the joining surface and one of the remaining surfaces corresponding to a pair of surfaces facing each other and adjacent to the one configuring wall. A processing step of forming an intermediate molded product having a pair of adjacent constituent wall portions having a right angle with respect to the one constituent wall portion and in which the pair of sides are in a non-contact state;
In order to generate a springback force at a symmetrical position of the pair of adjacent constituent wall portions while applying an external force to the pair of adjacent constituent wall portionsConvex part that protrudes inwardAnd a processing step for bringing the pair of sides into close contact with each other in this order,
  SaidThe pair of sides are in close contact with each other based on the springback force generated at the convex partdo itIn addition, the pair of surfaces are provided with protrusions for preventing close contact with other pipe bodies.
  Claim 1 or claim 2According to the invention according to the present invention, since the projecting portion for preventing the close contact with the other pipe body is provided, even if the other pipe body comes into contact with the surface before the lubricant is volatilized, An air passage corresponding to the height of the protrusion is ensured between them, and a situation where volatilization of the lubricating oil is prevented is prevented. Therefore, the pipe body can be manufactured at a low cost using the quick-drying lubricating oil, and the handling of the pipe body after completion is facilitated without the need for a cleaning process or the like.
  Claim 3The invention according toClaim 1 or claim 2In the pipe body described in item 2, the protrusion is formed by press working.
  Claim 3According to the invention, since the protrusion is formed by press working, another member for forming the protrusion (for example, the screw when the screw is attached to any surface of the pipe body to form the protrusion) And a secondary process is unnecessary and a pipe body can be manufactured at low cost.
  Claim 4The invention according toClaim 3In the pipe body described in item 2, the protrusion is formed by half-punching.
  Claim 4According to this invention, since the projection is formed by half punching, the mold structure can be simplified as compared with the case where it is formed by bending or the like. In addition, since the metal plate can be formed simultaneously when the metal plate is cut off, the cost of the pipe body can be further reduced.
  Claim 5The invention according toClaim 3In the pipe body described in the item 1, the protrusion is formed by burring.
  Claim 5According to the invention according to the above, since the protrusion is formed by burring, it is easy to increase the height of the protrusion as compared with the case of forming the protrusion by half punching. Increasing the height of this protrusion shortens the volatilization time of the lubricating oil, but the space efficiency (conveying efficiency) during conveyance tends to decrease. Decreasing the height increases the volatilization time of the lubricating oil. However, since the transport efficiency tends to improve, the height of the protrusions is increased as described above, so that protrusions with the optimum height are formed in consideration of the volatilization time of the lubricant and the transport efficiency. It becomes easy.
  Claim 6The invention according toClaim 3In the pipe body described in item 1, the protrusion is formed by bridge processing.
  Claim 6According to the invention, since the protrusion is formed by bridge processing, it is easy to increase the height of the protrusion as in the case of forming it by burring, and the volatilization time of the lubricating oil and the conveyance efficiency are taken into consideration. It is easy to form the protrusion with the optimum height.
  Claim 7The invention according toClaim 3In the pipe body described in item 2, the protrusion is formed by embossing.
  Claim 7According to the invention, since the protrusion is formed by embossing, it is easy to increase the height of the protrusion as in the case of forming it by burring or bridge processing.
  Also, embossing does not require pilot holes during burring, nor does it require relief holes as in bridge processing. Since the protrusions can be formed simultaneously, the pipe body can be further reduced in price.
  Claim 8The invention according toClaims 1 to 7In the pipe body according to any one of the above, the protrusion is provided on one end side in the longitudinal direction of the pipe body.
  Claim 8According to the invention according to the present invention, since the protrusion is provided on one end side in the longitudinal direction of the pipe body, the pipe body can be inserted and attached for convenience of use of the pipe body. If the body is inserted from the other end side in the longitudinal direction, interference between the protrusion and other parts can be avoided. That is, since the protrusion does not hinder the insertion of the pipe body, it is not necessary to provide a structure for avoiding interference with the protrusion on the other parts, and the pipe body is incorporated into the existing structure as it is. be able to.
  Claim 9The invention according toClaims 1 to 8An image forming apparatus using the pipe body according to any one of the above.
  Claim 9According to the invention according toClaims 1 to 8Since the pipe body according to any one of the above is used,Claims 1 to 8Any of the effects can be obtained. Also, by using many pipe bodies, the manufacturing cost of the image forming apparatus can be greatly reduced.
  Claim 10The invention according toClaim 8An image forming apparatus using the pipe body according to claim 1, further comprising a pipe body mounting portion to which the pipe body is inserted and attached, wherein the pipe body is attached to the pipe body from the other end side in the longitudinal direction. It is inserted in the part.
  Claim 10According to the invention, since the pipe body provided with the protrusion on one end side in the longitudinal direction is inserted and attached to the pipe body attachment section from the other end side in the longitudinal direction, the protrusion is formed on the pipe body. There is no need to obstruct the insertion, and it is not necessary to provide a structure for avoiding interference with the protrusion on the pipe body mounting portion.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
[0033]
[Pipe body production example 1]
1 is a perspective view and a partial cross-sectional view showing a schematic configuration of a pipe body having a rectangular cross section, FIG. 2 is a front view showing a cross-sectional shape of the pipe body, and FIG. 3 is a plan view of the pipe body. is there. The pipe body 1 includes, as four surfaces corresponding to each side of the rectangle shown in FIG. 2, a bottom surface constituting wall portion 2, a pair of side surface constituting wall portions 3 and 4 adjacent to the bottom surface constituting wall portion 2, and a bottom surface constituting wall. It has an upper surface constituting wall portion 5 facing the portion 2.
[0034]
Protrusions 3 a and 4 a are formed on the side surface constituting wall portions 3 and 4 so as to protrude toward the outside of the pipe body 1. The upper surface constituting wall portion 5 has a pair of seam constituting wall portions 5a and 5b in close contact with each other at the end surfaces 5c and 5d, and a seam (joining portion) 5e is formed at the center of the upper surface constituting wall portion 5. Yes.
[0035]
This pipe body 1 is formed by press working using a quick-drying lubricating oil from a rectangular metal plate 6 having a pair of parallel sides 6e, 6e shown in FIG. A screw hole 6a is formed in the metal plate 6 in advance at an appropriate place. This screw hole 6a is used to attach an engaging portion (another pipe body or the like to the pipe body 1) when the pipe body 1 is used as a frame to be described later. It is used as an engaging portion used when attaching or attaching the pipe body 1 to another member. Note that a notch or the like may be formed as such an engaging portion instead of the screw hole 6a.
[0036]
The protrusions 3a and 4a are provided by pressing between the folding lines 6c and 6c and the folding lines 6d and 6d extending in the same direction as the pair of sides 6e and 6e of the metal plate 6. Here, the protrusions 3a and 4a are formed by half-cutting simultaneously with the drilling of the screw holes 6a when the metal plate 6 is cut off.
[0037]
When the pipe body 1 is pressed, first, as a first processing step, the side portions 6b and 6b of the metal plate 6 are bent upright at a right angle (90 °) along the folding lines 6c and 6c. Thereby, the side parts 6b and 6b form a pair of seam-constituting wall parts 5a and 5b, and the primary intermediate molded product 8 having a concave cross section shown in FIG. 5 is formed. In FIG. 5, reference numeral 9 denotes an unfolded portion, and the fold lines 6 d and 6 d serve as a reference when the unfolded portion 9 is bent later. The dimensions of the metal plate 6 and the positions of the fold lines 6c and 6c and the fold lines 6d and 6d are determined in consideration of the amount of metal elongation due to press working.
[0038]
For the press working of the primary intermediate molded product 8, for example, a press device 10 shown in FIG. 6 is used. The pressing device 10 is roughly constituted by a first fixed plate 11, a first pressure punch member 12, and a movable plate 12 ′, and the first fixed plate 11 has an outer shape (joint constituting wall portion 5a) of the primary intermediate molded product 8. , 5b outer shape) is provided with a recess 13 surrounded by a peripheral wall 11a having a shape corresponding to the outer shape. The first pressure punch member 12 has a shape corresponding to the inner shape of the primary intermediate molded product 8 and is moved up and down by a hydraulic cylinder device (not shown) with respect to the recess 13. The movable plate 12 'is connected to another hydraulic cylinder device (not shown) so as to slide relative to the peripheral wall 11a of the first fixed plate 11 as the first pressure punch member 12 moves up and down. On the upper surface of the movable plate 12 ', concave relief portions 12'a and 12'b are provided.
[0039]
The metal plate 6 is placed on the movable plate 12 ′ that is higher than the fixed plate 11 by H with the first pressure punch member 12 and the movable plate 12 ′ positioned upward (FIG. 6A). The first intermediate punch 8 is formed by lowering the first pressure punch member 12 and sandwiching and pressing the metal plate 6 with the movable plate 12 ′ (FIG. 6B). At this time, the protrusions 3a and 4a of the metal plate 6 are positioned in the recesses 12'a and 12'b, respectively, so that the protrusions 3a and 4a and the movable plate 12 'do not interfere with each other.
[0040]
Next, as a second processing step, the unbent portion 9 of the primary intermediate molded product 8 is bent at an angle θ1 slightly larger than a right angle along the bending lines 6d and 6d and sandwiched between the bending lines 6d and 6d. The portion is curved so as to be convex upward. As a result, as shown in FIGS. 7 and 8, the secondary intermediate molded product 14 is formed as an intermediate molded product having the seam-constituting wall portions 5a and 5b, the one-constituting wall portion 15 and the adjacent constituent wall portions 16a and 16b. Is done.
[0041]
For example, a press device 17 shown in FIG. 9 is used to press the secondary intermediate molded product 14. The press device 17 is generally configured by a second fixed plate 19 having a recess 18 and relief portions 19b and 19c, a second pressure punch member 20, and a movable plate 20 '. The recess 18 is surrounded by a peripheral wall 19a having a shape corresponding to the outer shape of the secondary intermediate molded product 14 (the outer shape of the adjacent constituent wall portions 16a and 16b). The escape portions 19b and 19c are provided in a groove shape from the upper surface of the second fixed plate 19 to the peripheral wall 19a. The second pressurizing punch member 20 is moved up and down by a hydraulic cylinder device (not shown) with respect to the recess 18, and the lower part thereof has an inner shape of the constituent wall portion 15 of the secondary intermediate molded product 14 and an adjacent constituent wall portion 16 a. , 16b is provided with a punch portion 20a having a shape corresponding to the lower inner shape. The movable plate 20 ′ is connected to another hydraulic cylinder device (not shown) so as to slide relative to the second fixed plate 19 as the second pressure punch member 20 moves up and down. The upper surface 20 a ′ of the movable plate 20 ′ is finished in a shape corresponding to the outer shape of the constituent wall portion 15 of the secondary intermediate molded product 14.
[0042]
The primary intermediate molded product 8 is placed on the movable plate 20 ′ that is higher than the fixed plate 19 by H ′ in a state where the second pressure punch member 20 and the movable plate 20 ′ are positioned upward (FIG. 9). (A)) The second pressure punch member 20 is moved down to enter the concave shape of the primary intermediate molded product 8 and is not moved by the punch portion 20a of the second pressure punch member 20 and the upper surface 20a ′ of the movable plate 20 ′. By sandwiching and pressurizing the bent portion 9, the secondary intermediate molded product 14 is formed (FIG. 9B). During this processing, the protrusions 3a and 4a are positioned at the escape portions 19b and 19c, respectively, so that the protrusions 3a and 4a and the second fixing plate 19 do not interfere with each other.
[0043]
The secondary intermediate molded product 14 is removed from the press device 17 by raising the second pressure punch member 20 to release the pressurized state, and then moving the secondary intermediate molded product 14 in the longitudinal direction (perpendicular to the paper surface in FIG. 9). Direction). However, for example, when the curvature of one constituent wall 15 is increased as shown in FIG. 10 or when the ratio of the length of the adjacent constituent walls 16a and 16b to the one constituent wall 15 is large as shown in FIG. Can be pulled out between the pair of sides 6e and 6e simply by raising the second pressure punch member 20. Thereby, the work process of pulling out the secondary intermediate molded product 14 in the longitudinal direction can be omitted, and the efficiency of the molding work and the reduction of the work space can be achieved.
[0044]
In addition, by using the press apparatus 17 shown in FIG. 12, the secondary intermediate molded product in which the one constituent wall portion 15 shown in FIG. 13 is flat (not curved) may be formed. The angle θ2 formed by the wall portion 15 and the adjacent constituent wall portions 16a and 16b is a larger obtuse angle than the angle θ1 shown in FIG. Further, considering the flatness of the bottom surface constituting wall portion 2 when the pipe body 1 is completed, or the removal of the secondary intermediate molded product 14 from the press device 17 merely raises the second pressure punch member 20. In view of this, it is preferable that the one structural wall 15 is curved as shown in FIGS. However, in FIG. 7 and FIG. 8, one component wall portion 15 in a curved state is composed of a central flat portion 15b, curved portions 15c and 15c on both sides thereof, and flat portions 15a and 15a. For example, the one constituent wall portion 15 may be curved with a uniform curvature throughout.
[0045]
Next, in order to form the secondary intermediate molded product 14 into the pipe body 1 as a finished product, a press molding apparatus 21 shown in FIG. 14 is used. The press molding apparatus 21 is generally composed of a lower mold (fixed mold) 22 and an upper mold (movable mold) 23. The lower mold 22 has a third fixed plate 24, and the upper mold 23 is formed by a cylinder device (not shown). It has a movable plate 25 that moves up and down.
[0046]
The third fixed plate 24 is provided with a pair of stopper members 26 and 26 and third pressure punch members 27 and 27 as punch members. The pair of third pressure punch members 27, 27 are slidably provided on a slide rail (not shown) extending in the left-right direction in FIG. 14, and interlocked in a direction approaching or separating from each other by a cam mechanism (not shown). To move. In the state where the lower die 22 and the upper die 23 are separated as shown in the figure, the third pressure punch members 27 and 27 are urged away from each other by a spring member (not shown). .
[0047]
Punch surfaces 27b and 27b for pressing the adjacent constituent wall portions 16a and 16b of the secondary intermediate molded product 14 are formed on the surfaces of the third pressure punch members 27 and 27 that face each other. The punch surfaces 27b and 27b are provided with recessed relief portions 27d and 27e.
[0048]
The movable plate 25 is provided with drive members 29 and 29 for driving the third pressure punch members 27 and 27, and a fourth pressure punch for pressing the pair of seam constituting wall portions 5a and 5b. A member 30 is provided. Tapered portions 29a, 29a are formed inside the lower portions of the drive members 29, 29, and tapered portions 27a, 27a that engage with the tapered portions 29a, 29a are formed outside the upper portions of the third pressure punch members 27, 27. ing.
[0049]
As a third processing step, the secondary intermediate molded product 14 is first set in the facing space 28 of the third pressure punch members 27 and 27 so that the one constituent wall portion 15 faces downward (FIG. 14). When the upper mold 23 is lowered from this state as indicated by an arrow A, the taper portions 29a and 29a of the drive members 29 and 29 engage with the taper portions 27a and 27a of the third pressure punch members 27 and 27, and The three pressure punch members 27 and 27 are driven in a direction approaching each other against the biasing force of the spring member (FIG. 15). As a result, the punch surfaces 27b, 27b of the third pressure punch members 27, 27 come into contact with the bent portions 31a, 31b that form the boundary between the adjacent constituent wall portions 16a, 16b and the joint constituent wall portions 5a, 5b, and are adjacent to each other. The constituent wall portions 16a and 16b are pressurized in a direction approaching each other by an external force applied by the punch surfaces 27b and 27b.
[0050]
When the third pressure punch members 27 and 27 are further driven in a direction approaching each other, the bent portions 31a and 31b slide upward along the punch surfaces 27b and 27b, and the one constituent wall portion 15 is located outside (lower side). Then, the end surfaces 5c and 5d come close to each other and finally come into close contact with each other to form the upper surface constituting wall 5 (FIG. 17). At this time, the protrusions 3a and 4a are positioned at the escape portions 27d and 27e, respectively, and do not interfere with the third pressure punch members 27 and 27, and the adjacent constituent wall portions 16a and 16b stand up completely and the side constituent wall Portions 3 and 4 are formed.
[0051]
Subsequently, when the upper die 23 is further lowered as the fourth machining step, the engagement between the tapered portions 27a, 27a of the third pressure punch members 27, 27 and the tapered portions 29a, 29a of the drive members 29, 29 is released. Then, the third pressure punch members 27, 27 are stopped at that position. When the upper die 23 is lowered in this state (that is, with the pressure applied to the side surface constituting wall portions 3 and 4 maintained), the fourth pressure punch member 30 comes into contact with the upper surface constituting wall portion 5 and the upper surface constituting wall. The part 5 is pressurized (FIG. 18). By pressurization of the fourth pressure punch member 30, the one constituent wall portion 15 that is convexly curved downward is pressed by the third fixing plate 24, and is deformed into a flat shape to form the bottom constituent wall portion 2. .
[0052]
Then, when the upper die 23 is raised and separated from the lower die 22, the third pressure punch members 27 and 27 move again in the direction away from each other, and the completed pipe body 1 is obtained.
[0053]
By the way, in general, when a workpiece is deformed by pressing (bending), a springback (a phenomenon in which the deformation is somewhat restored by the elasticity of the workpiece after the machining force is removed) is produced. Further, the bottom-constituting wall portion 2 of the pipe body 1 tends to return to the curved surface as shown by a chain line in FIG. 19 due to the stress (spring back force) generated with the spring back. That is, since the springback force f1 acts in the direction in which the joint 5e is closed, it is possible to prevent the end faces 5c and 5d from coming into close contact with each other without performing welding or the like so that a gap is generated between them.
[0054]
As shown in FIG. 20, the pipe body 1 manufactured in this way is adsorbed by a robot finger (air sucker) 87 that is provided on the robot arm 86 and moves in the direction of arrow B, and is conveyed onto a belt conveyor 88. . The robot arm 86 connects the press device 10, the press device 17, and the press molding device 21 with the belt conveyor 88, and when the primary intermediate molded product 8 manufactured by the press device 10 is conveyed to the press device 17, and the press It is also used when the secondary intermediate molded product 14 manufactured by the device 17 is conveyed to the press molding device 21.
[0055]
The pipe body 1 conveyed to the belt conveyor 88 is sequentially conveyed onto the work table 89 where the worker M waits. When a certain number of pipe bodies 1 are collected on the work table 89, the worker M holds them together from the side with his / her left and right hands and stores them in the resin component storage box 90. The storage in the component storage box 90 may be performed one by one instead of grouping the plurality of pipe bodies 1 as described above, but it is preferable to perform grouping as described above from the viewpoint of work efficiency. Further, this storage may be performed not by the worker M but by a robot.
[0056]
The pipe bodies 1 stored in the component storage box 90 are arranged on the cardboard plate 91 in the component storage box 90 as shown in FIG. Here, since the projecting portions 3a and 4a are provided on the side surface constituting wall portions 3 and 4 of each pipe body 1, a plurality of pipe bodies 1 are accommodated together and adjacent to each other as described above. Even if the side wall portions of each other come into contact with each other, a gap s corresponding to the height h (see FIG. 2) of the projections 3a and 4a is secured between them, and the lubricant adhering to the pipe body 1 volatilizes. This prevents the situation from being hindered. In this embodiment, the size of the gap s is about 0.5 mm, but this is sufficient for volatilizing the lubricating oil. The number of pipe bodies 1 that can be stored is not changed compared to the case where there is no gap (when the projections 3a and 4a are not formed).
[0057]
Further, since the protrusions 3a and 4a are provided on the side surface constituting wall portions 3 and 4 different from the bottom surface constituting wall portion 2 on which the springback force acts, the springback force is increased with the formation of the protrusions 3a and 4a. In particular, since the protrusions 3a and 4a are formed by half-punching when the metal plate 6 is cut off, an extra step for forming the protrusion does not occur. The cost can be reduced.
[0058]
[Usage example of manufactured pipe body]
The pipe body 1 stored in the component storage box 90 is used for a frame (supporting member) of a facsimile / copier as an image forming apparatus. That is, a mounting frame 39 is attached to the pipe body 1 as shown in FIG. 22, thereby forming a cantilevered frame body 38 as a frame. As shown in FIG. 23, the cantilevered frame body 38 is attached to a pipe body mounting portion 94 formed as a facing space between the side plate 92 and the plate material 93. The pipe body 1 is inserted into the pipe body mounting portion 94 while 3 and 4 are brought into sliding contact with the plate member 93 and the side plate 92, respectively. Then, the screw hole 6 a of the pipe body 1, the side plate 92, and the plate material 93 are screwed using the screws 95, and the scanner unit 96 is placed on the placement frame 39.
[0059]
As is clear from the above-described drawings, here, the projecting portions 3a and 4a are provided on one end side in the longitudinal direction of the pipe body 1, and the mounting frame 39 is attached to the one end side. When being attached to the pipe body attaching portion 94 from the other end side in the longitudinal direction, the protrusions 3a and 4a do not interfere with the plate material 93 and the side plate 92, and therefore do not hinder the insertion of the pipe body 1 and the pipe body attaching portion 94. It is not necessary to provide a structure for avoiding interference with the protrusions 3a and 4a.
[0060]
[Other examples of protrusions]
In the pipe body 1 described above, the protrusions 3a and 4a are formed by half-punching. However, even if these are formed by burring as shown in FIG. 24, for example, they are formed by bridge processing as shown in FIGS. It may be formed, or may be formed by embossing as shown in FIG.
[0061]
If the protrusions 3a and 4a are formed by burring, the height of the protrusions 3a and 4a can be easily increased as compared with the case where they are formed by half punching. Thus, the height of the protrusions 3a and 4a is increased. By increasing the degree of freedom, it becomes easy to form a protrusion having an optimum height in consideration of the volatilization time of the lubricating oil and the conveyance efficiency.
[0062]
On the other hand, if the protrusions 3a and 4a are formed by bridge processing, the height of the protrusions 3a and 4a can be easily increased as in the case of burring, and the protrusions 3a and 4a can be formed by embossing. Also, it is easy to increase its height. Furthermore, the embossing does not require a pilot hole at the time of processing as in burring, nor does it require an escape hole as in the bridge processing, so the processing process is not bulky, and when taking a metal plate Since the protrusions can be formed simultaneously, the cost of the pipe body 1 can be reduced extremely effectively.
[0063]
Further, in the pipe body 1, the protrusions 3 a and 4 a are formed on one end side in the longitudinal direction of the pipe body 1. However, unless the transport efficiency by the component storage box 90 is remarkably deteriorated, or the pipe body at the time of insertion As long as interference with the attachment portion 94 is dealt with, the formation position of the protrusion is not necessarily limited to the above. For example, as shown in FIG. 28, the protrusions 3a, 4a may be aligned in the longitudinal direction, and the protrusion 3b may be provided on the side wall 3 instead of the protrusion 4a as shown in FIG. As shown in FIG. 30, the position of the protrusion 4a may be shifted to the other end in the longitudinal direction.
[0064]
[Pipe body production example 2]
FIG. 31 shows another example of a press molding apparatus for molding the secondary intermediate molded product 14 into the pipe body 1. In the press molding apparatus 97, unlike the press molding apparatus 21, the pressure punch member 30 is not provided, and the friction contact members 27c, 27c are provided on the punch surfaces 27b, 27b of the third pressure punch members 27, 27. ing.
[0065]
As in the press molding apparatus 21, the secondary intermediate molded product 14 is set in the facing space 28 of the third pressure punch members 27, 27 so that the one constituent wall portion 15 faces downward (FIG. 31). When the upper mold 23 is lowered from this state as indicated by an arrow A, the taper portions 29a and 29a of the drive members 29 and 29 engage with the taper portions 27a and 27a of the third pressure punch members 27 and 27, and The three pressure punch members 27, 27 are driven in a direction approaching each other against the biasing force of a spring member (not shown) (FIG. 32). As a result, the friction contact members 27c and 27c of the third pressure punch members 27 and 27 come into contact with the bent portions 31a and 31b, and the adjacent constituent wall portions 16a and 16b are brought into contact with each other by the external force applied by the friction contact members 27c and 27c. Pressurized in the approaching direction.
[0066]
With the pressurization by the third pressurizing punch members 27, 27, the bent portions 31a, 31b try to slide upward with respect to the punch surfaces 27b, 27b, but receive a frictional resistance force from the friction contact members 27c, 27c. As a result, a downward force acts on the flat portion 15b of the one constituent wall portion 15 and the boundary portion between the one constituent wall portion 15 and the adjacent constituent wall portions 16a and 16b is fixed to the third portion. Reaction force R1, R1 is received from the plate 24 (FIG. 33).
[0067]
When the third pressurizing punch members 27 and 27 are further driven in a direction approaching each other, the adjacent constituent wall portions 16a and 16b stand while the bent portions 31a and 31b are slightly displaced upward along the punch surfaces 27b and 27b. . At the same time, the flat portion 15b of the one constituent wall portion 15 bulges downward and comes into contact with the third fixed plate 24, and receives a reaction force R2 from the third fixed plate 24 (FIG. 34). If the maximum static frictional force between the frictional contact members 27c and 27c and the bent portions 31a and 31b is almost the same as the sum of the reaction force R2 and the reaction forces R1 and R1, the addition of the third fixed plate 24 to the flat portion 15b. The one structural wall portion 15 is deformed so as to approach the third fixed plate 24 as a whole while maintaining the pressure state.
[0068]
Subsequently, when the upper die 23 is further lowered, the engagement between the tapered portions 27a, 27a of the third pressure punch members 27, 27 and the tapered portions 29a, 29a of the drive members 29, 29 is released, and the third additional punch 23 is released. The pressure punch members 27 and 27 are stopped, and the end surfaces of the seam constituting wall portions 5a and 5b are completely brought into close contact with each other, and the deformation of the one constituting wall portion 15 into the flat shape is completed (FIG. 35).
[0069]
Then, when the upper die 23 is raised and separated from the lower die 22, the third pressure punch members 27 and 27 move again in the direction away from each other, and the completed pipe body 1 is obtained.
[0070]
The bottom-constituting wall portion 2 of the pipe body 1 manufactured in this way has a tendency to bulge outward in the direction opposite to the direction in which the reaction force R2 acts, that is, outward, by removing the reaction force R2. . This means that a springback force is acting in the opposite direction, and the contact state of the joint 5e is thereby maintained.
[0071]
Since the pipe body 1 manufactured in this way is also provided with the projections 3a and 4a on the side wall portions 3 and 4 thereof as described above, even if the pipe body 1 is stored in the component storage box 90 immediately after completion, the lubricating oil Does not interfere with volatilization. Further, since the protrusions 3a and 4a are provided on the side surface constituting wall portions 3 and 4 different from the bottom surface constituting wall portion 2 on which the springback force acts, the springback force is increased with the formation of the protrusions 3a and 4a. It does not stop working well, and a decrease in yield due to the formation of the protrusions is prevented.
[0072]
In the press molding apparatus 97, friction contact members 27c and 27c are provided on the third pressure punch members 27 and 27 to prevent the bending portions 31a and 31b from slipping, thereby pressing one component wall portion 15. As shown in FIG. 36, engagement protrusions 27f and 27g may be provided instead of the friction contact members 27c and 27c, and the bending portions 31a and 31b may be suppressed from above by the engagement protrusions 27f and 27g to prevent the slippage. .
[0073]
[Pipe body production example 3]
FIG. 37 is a perspective view showing a schematic configuration of a pipe body 1 ′ having a rectangular cross section, and FIG. 38 is a front view showing a cross sectional shape of the pipe body 1 ′. This pipe body 1 ′ has four surfaces corresponding to each side of the rectangle shown in FIG. 38 as a bottom surface constituting wall portion 2 ′ and a pair of side surface constituting wall portions 3 ′ and 4 ′ adjacent to the bottom surface constituting wall portion 2 ′. And the upper surface constituting wall portion 5 facing the bottom surface constituting wall portion 2 ′.
[0074]
The pipe body 1 ′ is manufactured in substantially the same manner as the pipe body 1, but a plurality of convex portions 3 are formed on the side surface constituting wall portions 3 ′ and 4 ′ so as to protrude toward the inside of the pipe body 1 ′. 'a, 4'a are formed at equal intervals along the longitudinal direction. The convex portions 3 ′ a and 4 ′ a are positioned symmetrically with respect to the center line O <b> 1 passing through the joint line 5 e of the upper surface constituting wall portion 5 and the axis of the pipe body 1 ′.
[0075]
When the pipe body 1 ′ is pressed, the metal plate 6 is first processed into a primary intermediate molded product 8 by the press device 10, and the primary intermediate molded product 8 is processed into the secondary intermediate molded product 14 by the press device 17. . However, the secondary intermediate molded product 14 is different from the secondary intermediate molded product 14 shown in FIGS. 7 and 8 in that the angle formed by the one constituent wall portion 15 and the adjacent constituent wall portions 16a and 16b is a right angle. The press device 17 used here is also different from the above-mentioned one only in that respect.
[0076]
The secondary intermediate molded product 14 is processed into a pipe body 1 'by a press molding apparatus 98 shown in FIG. In the press molding apparatus 98, unlike the press molding apparatus 21, the frictional contact members 27c, 27c are not provided on the punch surfaces 27b, 27b of the third pressure punch members 27, 27, but instead the convex portions 3′a, Convex portion forming portions 27h and 27i for forming 4'a are provided.
[0077]
In the press molding apparatus 98, the secondary intermediate molded product 14 is set in the facing space 28 of the third pressure punch members 27, 27 so that the one constituent wall portion 15 faces downward (FIG. 39). When the upper mold 23 is lowered from this state as indicated by an arrow A, the taper portions 29a and 29a of the drive members 29 and 29 engage with the taper portions 27a and 27a of the third pressure punch members 27 and 27, and The three pressure punch members 27 and 27 are driven in a direction approaching each other against the biasing force of a spring member (not shown) (FIG. 40). Thereby, the punch surfaces 27b and 27b of the third pressure punch members 27 and 27 come into contact with the bent portions 31a and 31b, and the adjacent component wall portions 16a and 16b approach each other by an external force applied by the punch surfaces 27b and 27b. Pressurized in the direction.
[0078]
When the third pressure punch members 27 and 27 are further driven in a direction approaching each other, the bottom surface constituting wall portion 2 ′ is formed while the curvature of the one constituting wall portion 15 is removed, and the end surfaces 5 c and 5 d are approached. Finally, the upper surface constituting wall portion 5 is formed in close contact (FIG. 41). Further, at this time, the convex portion forming portions 27h and 27i are close to the one constituent wall portion 15 of the adjacent constituent wall portions 16a and 16b (the lower portion from the center in the height direction of the adjacent constituent wall portions 16a and 16b). Convex portions 3′a and 4′a are formed.
[0079]
Subsequently, when the upper die 23 is further lowered, the engagement between the tapered portions 27a, 27a of the third pressure punch members 27, 27 and the tapered portions 29a, 29a of the drive members 29, 29 is released, and the third additional punch 23 is released. The pressure punch members 27, 27 are stopped at that position. When the upper die 23 is lowered in this state, the fourth pressure punch member 30 comes into contact with the upper surface constituting wall portion 5 and the upper surface constituting wall portion 5 is pressurized (FIG. 42). Although the upper surface constituting wall portion 5 and the bottom surface constituting wall portion 2 ′ can be more reliably flattened by the pressurization of the fourth pressure punch member 30, this final processing step is not necessarily essential.
[0080]
Then, when the upper die 23 is raised and separated from the lower die 22, the third pressure punch members 27 and 27 are moved again in the direction away from each other to obtain a completed pipe body 1 '.
[0081]
The pipe body 1 ′ is formed with convex portions 3′a and 4′a, and a springback force f2 is generated at the convex portions 3′a and 4′a as shown in FIG. The force f2 cancels the springback force generated on the bottom surface constituting wall portion 2 'or acts to close the seam 5e with a larger magnitude so that the end faces 5c and 5d are brought into close contact without welding or the like. Thus, it is possible to prevent a gap between the two. On the other hand, since the projecting portions 3a and 4a are provided on the side surface configuration wall portions 3 'and 4' by half-punching or the like, even if the pipe body 1 'is stored in the component storage box 90 immediately after completion, the lubricating oil Does not interfere with volatilization of
[0082]
Further, since the convex portions 3'a and 4'a are provided near the bottom surface constituting wall portion 2 ', that is, on the side far from the joint 5e, near the joint constituting wall portion 5, that is, near the joint 5e. A force in the direction of closing the end surfaces 5c and 5d can be applied more efficiently than when provided on the side. Further, since the convex portions 3'a and 4'a are in a symmetrical position with respect to the joint 5e, the force in the direction in which the end surfaces 5c and 5d are closed can be applied in a balanced manner.
[0083]
In addition, this invention is not restricted to the form mentioned above, For example, the cross-sectional shape of a pipe body may be other squares, such as a parallelogram and a trapezoid, even if it is not a rectangle. Alternatively, the cross-sectional shape of the pipe body may be a triangle, a hexagon, an octagon, or the like if the surfaces may be in close contact with each other. Further, the joint portion on the joint surface does not need to be in the vicinity of the center of the joint surface, and may be in the vicinity of the boundary with other surfaces (near the ridgeline).
[0084]
【The invention's effect】
  As explained above,Claim 1 or claim 2According to the invention according to the present invention, since the projecting portion for preventing the close contact with the other pipe body is provided, even if the other pipe body comes into contact with the surface before the lubricant is volatilized, An air passage corresponding to the height of the protrusion is ensured between them, and a situation where volatilization of the lubricating oil is prevented is prevented. Therefore, the pipe body can be manufactured at a low cost using the quick-drying lubricating oil, and the handling of the pipe body after completion is facilitated without the need for a cleaning process or the like.
  Claim 3According to this invention, since the projection is formed by press working, a separate member or a secondary process for forming the projection is unnecessary, and the pipe body can be manufactured at low cost.
  Claim 4According to this invention, since the projection is formed by half punching, the mold structure can be simplified as compared with the case where it is formed by bending or the like. In addition, since the metal plate can be formed simultaneously when the metal plate is cut off, the cost of the pipe body can be further reduced.
  Claim 5According to the invention according to the above, since the protrusion is formed by burring, it is easy to increase the height of the protrusion as compared with the case of forming the protrusion by half punching. Increasing the height of this protrusion shortens the volatilization time of the lubricating oil, but the space efficiency (conveying efficiency) during conveyance tends to decrease. Decreasing the height increases the volatilization time of the lubricating oil. However, since the transport efficiency tends to improve, the height of the protrusions is increased as described above, so that protrusions with the optimum height are formed in consideration of the volatilization time of the lubricant and the transport efficiency. It becomes easy.
  Claim 6According to the invention, since the protrusion is formed by bridge processing, it is easy to increase the height of the protrusion as in the case of forming it by burring, and the volatilization time of the lubricating oil and the conveyance efficiency are taken into consideration. It is easy to form the protrusion with the optimum height.
  Claim 7According to the invention, since the protrusion is formed by embossing, it is easy to increase the height of the protrusion as in the case of forming it by burring or bridge processing.
  Also, embossing does not require pilot holes during burring, nor does it require relief holes as in bridge processing. Since the protrusions can be formed simultaneously, the pipe body can be further reduced in price.
  Claim 8According to the invention according to the present invention, since the protrusion is provided on one end side in the longitudinal direction of the pipe body, the pipe body can be inserted and attached for convenience of use of the pipe body. If the body is inserted from the other end side in the longitudinal direction, interference between the protrusion and other parts can be avoided. That is, since the protrusion does not hinder the insertion of the pipe body, it is not necessary to provide a structure for avoiding interference with the protrusion on the other parts, and the pipe body is incorporated into the existing structure as it is. be able to.
  Claim 9According to the invention according toClaims 1 to 8Since the pipe body according to any one of the above is used,Claims 1 to 8Any of the effects can be obtained. Also, by using many pipe bodies, the manufacturing cost of the image forming apparatus can be greatly reduced.
  Claim 10According to the invention, since the pipe body provided with the protrusion on one end side in the longitudinal direction is inserted and attached to the pipe body attachment section from the other end side in the longitudinal direction, the protrusion is formed on the pipe body. There is no need to obstruct the insertion, and it is not necessary to provide a structure for avoiding interference with the protrusion on the pipe body mounting portion.
[0085]
According to the fourth aspect of the present invention, the protrusions for preventing adhesion to the other pipe body on at least one of the pair of parallel surfaces that are parallel to each other and sandwiching the springback force acting surface and the joining surface. Since the pipe is provided, even if another pipe body comes into contact with the parallel surface before the lubricant is volatilized, an air passage according to the height of the protrusion is secured between the two and lubrication. The situation where the volatilization of oil is prevented is prevented. Here, the parallel surface has better flatness than the spring back acting surface and the joint surface, and when the pipe bodies are arranged in a space-efficient manner, there is a high probability of coming into contact with other pipe bodies. By providing, it is possible to effectively secure a gap between the pipe bodies in parallel.
[Brief description of the drawings]
FIG. 1 shows a pipe body according to the present invention, in which (a) is a perspective view thereof, and (b) is an enlarged sectional view of a protrusion.
FIG. 2 is a front view showing the pipe body of FIG. 1;
FIG. 3 is a plan view showing the pipe body of FIG. 1;
4 is a plan view showing a metal plate used for manufacturing the pipe body of FIGS. 1 to 3; FIG.
FIG. 5 is a front view showing a primary intermediate molded product.
6A and 6B show a pressing device used for forming the primary intermediate molded product of FIG. 5, in which FIG. 6A is an explanatory diagram of a state where a metal plate is placed on a movable plate, and FIG. 6B is a state where the metal plate is pressurized. It is explanatory drawing of.
FIG. 7 is a front view showing a secondary intermediate molded product.
8 is a perspective view showing the secondary intermediate molded product of FIG. 7. FIG.
9A and 9B show a press device used for forming the secondary intermediate molded product of FIGS. 7 and 8, wherein FIG. 9A is an explanatory view of a state where the primary intermediate molded product is placed on a movable plate, and FIG. It is explanatory drawing of the state which pressurized the intermediate molded product.
FIG. 10 is an explanatory view showing another example of a secondary intermediate molded product and a press device used for the molding.
FIG. 11 is a front view showing still another example of the secondary intermediate molded product.
FIG. 12 is an explanatory view showing still another example of a press device used for forming a secondary intermediate molded product.
13 is a front view showing a secondary intermediate molded product formed by the pressing device of FIG. 12. FIG.
14 is an explanatory view showing a state in which the secondary intermediate molded product of FIGS. 7 and 8 is set in a press molding apparatus. FIG.
15 is an explanatory view showing a state in which a third pressure punch member is in contact with a bent portion of a secondary intermediate molded product set in the press molding apparatus of FIG.
16 is an explanatory diagram showing a state in which one constituent wall portion of the secondary intermediate molded product set in the press molding apparatus of FIG. 14 is curved outward.
17 is an explanatory view showing a state where driving of the third pressure punch member is completed in the press molding apparatus of FIG. 14. FIG.
18 is an explanatory view showing a state in which the fourth pressure punch member presses the upper wall portion in the press molding apparatus of FIG. 14;
19 is an explanatory view conceptually showing a springback force acting on a pipe body manufactured by the press molding apparatus of FIG.
FIG. 20 is an explanatory view showing a state in which the manufactured pipe body is stored in the component storage box.
FIG. 21 is a plan view showing a pipe body stored in a component storage box.
FIGS. 22A and 22B show a cantilever frame body of a facsimile / copier according to the present invention, wherein FIG. 22A is a perspective view and FIG. 22B is a side view.
FIG. 23 is a perspective view showing a fax / copier incorporating the cantilevered frame body of FIG. 22;
24A and 24B show an example in which a protrusion is formed by burring, FIG. 24A is an external view thereof, and FIG. 24B is a cross-sectional view.
25A and 25B show an example in which a protrusion is formed by bridge processing, in which FIG. 25A is an external view thereof, and FIG. 25B is a cross-sectional view taken along line BB in FIG.
FIG. 26 is an external view showing another example of a protrusion formed by bridge processing.
27A and 27B show an example in which a protrusion is formed by embossing, in which FIG. 27A is an external view thereof, and FIG. 27B is a cross-sectional view.
FIG. 28 is a plan view showing an example in which the formation position of the protrusion is changed.
FIG. 29 is a plan view showing another example in which the formation position of the protrusion is changed.
FIG. 30 is a plan view showing still another example in which the formation position of the protrusion is changed.
FIG. 31 is an explanatory view showing another example of the press molding apparatus and showing a state in which a secondary intermediate molded product is set in the press molding apparatus.
32 is an explanatory view showing a state in which a third pressure punch member is in contact with a bent portion of a secondary intermediate molded product set in the press molding apparatus of FIG. 31. FIG.
33 is an explanatory view showing a state in which one constituent wall portion of the secondary intermediate molded product set in the press molding apparatus of FIG. 31 swells outward.
34 is an explanatory view showing a state in which a reaction force acts on one constituent wall portion swelled outward in the press molding apparatus of FIG. 31. FIG.
35 is an explanatory view showing a state where driving of the third pressure punch member is completed in the press molding apparatus of FIG. 31. FIG.
36 is an explanatory view showing another example of a press forming apparatus that realizes a forming process similar to that of the press forming apparatus of FIG. 31. FIG.
FIG. 37 is a perspective view showing another example of a pipe body according to the present invention.
38 is a front view showing the pipe body of FIG. 37. FIG.
FIG. 39 shows still another example of the press molding apparatus and is an explanatory view showing a state in which a secondary intermediate molded product is set in the press molding apparatus.
40 is an explanatory view showing a state in which a third pressure punch member is in contact with a bent portion of a secondary intermediate molded product set in the press molding apparatus of FIG. 39. FIG.
41 is an explanatory view showing a state where driving of the third pressure punch member is completed in the press molding apparatus of FIG. 39. FIG.
42 is an explanatory view showing a state where driving of the fourth pressure punch member is completed in the press molding apparatus of FIG. 39. FIG.
43 is an explanatory diagram conceptually showing a springback force acting on a pipe body manufactured by the press molding apparatus of FIG. 39. FIG.
FIG. 44 is a perspective view showing a pipe body that has already been proposed.
45 shows a state where the pipe body of FIG. 44 is housed in the component housing box, wherein (a) is a perspective view thereof, and (b) is a cross-sectional view taken along the line CC of (a).
[Explanation of symbols]
1,1 'pipe body
2 Bottom wall (remaining surface)
3,4 side wall (remaining surface)
3a, 4a Projection
5 Upper surface configuration wall (joint surface)
6 Metal plate
6c Folding line
6d fold line
6e A pair of sides
14 Secondary intermediate product (intermediate product)
f1, f2 Springback force

Claims (10)

A metal plate having a pair of sides parallel to each other is bent at a plurality of locations along a straight line parallel to the pair of sides, and the cross-section manufactured by joining the pair of sides is a polygonal pipe body. And
Of the surfaces corresponding to the sides of the polygon, one including the joint between the pair of sides is defined as a joint surface, and a surface other than the joint surface is a remaining surface. An angle formed between the one wall and the adjacent wall corresponding to the surface adjacent to the one surface is larger than the corresponding angle of the polygon. Processing steps for forming an intermediate molded product in which the sides of the two are in a non-adherent state;
A processing step of applying an external force to the adjacent constituent wall portion to form a curved surface bulging outward on the one constituent wall portion and bringing the pair of sides into close contact with each other;
A process step of deforming the curved surface into a flat shape by applying an external force to the one constituent wall portion in a state in which the pair of sides are in close contact with each other is manufactured in this order,
The pair of sides are in close contact with each other on the basis of a springback force that causes the flatly deformed portion to return to the original curved surface that bulges outward, and corresponds to one of the sides of the polygon A pipe body, characterized in that a projecting portion is provided on the surface to prevent contact with another pipe body. A metal plate having a pair of sides parallel to each other is bent at a plurality of locations along a straight line parallel to the pair of sides and the pair of sides are joined together to form a rectangular pipe body. And
Of the surfaces corresponding to the sides of the rectangle, a surface including the joint between the pair of sides is a bonding surface, and a surface other than the bonding surface is a remaining surface. One constituent wall portion corresponding to one surface facing the surface and a pair of opposing surfaces among the remaining surfaces, and adjacent to the one constituent wall portion and with respect to the one constituent wall portion A processing step of forming an intermediate molded product having a pair of adjacent constituent wall portions having a right angle and the pair of sides being in a non-contact state;
While applying an external force to the pair of adjacent constituent wall portions and forming a convex portion that protrudes inward in order to generate a springback force at a symmetrical position of the pair of adjacent constituent wall portions, the pair of sides Are formed in this order through the processing steps to adhere
The pair of sides are in close contact with each other based on a springback force generated at the boundary of the convex portion, and a protrusion for preventing close contact with another pipe body is provided on the pair of surfaces. And pipe body. The pipe body according to claim 1 or 2 , wherein the protrusion is formed by press working. The pipe body according to claim 3 , wherein the projection is formed by half-punching. 4. The pipe body according to claim 3 , wherein the protrusion is formed by burring. The pipe body according to claim 3 , wherein the protrusion is formed by bridge processing. The pipe body according to claim 3 , wherein the protrusion is formed by embossing. The pipe body according to any one of claims 1 to 7 , wherein the protrusion is provided on one end side in a longitudinal direction of the pipe body. An image forming apparatus using the pipe body according to any one of claims 1 to 8 . An image forming apparatus using the pipe body according to claim 8 , further comprising a pipe body mounting portion to which the pipe body is inserted and attached, and the pipe body from the other end side in the longitudinal direction. An image forming apparatus, wherein the image forming apparatus is inserted into a pipe body attaching portion.

Images