Metal-processed product, heat dissipation member, and developing device

Abstract

To provide a metal-processed product in which a joint between metal plates can be minimized, a heat dissipation member, and a developing device in an electro-photographic image forming apparatus.SOLUTION: A metal-processed product includes a first metal plate and a second metal plate. The first metal plate and the second metal plate respectively have a first end surface and a second end surface that face each other. The first end surface includes a protruding section protruding toward the second end surface. The second end surface has a notched section that has an engaging section where at least a portion thereof engages with the protruding section at a position corresponding to the protruding section of the first end surface. At least a portion of the protruding section contacts in the same shape with the engaging section. At least a portion of the protruding section overlaps in the plate thickness direction with both front and rear sides of an edge area being at least a portion of the notched section. There are also provided a heat dissipation member, and a developing device in an electro-photographic image forming apparatus.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a metal product used in a developing device in an electrophotographic image forming apparatus. [Background technology]

[0002] In a developing device in an electrophotographic image forming apparatus, an electrostatic latent image formed on an image carrier such as a photosensitive drum is developed to form a toner image. In this developing device, the developer contained therein is stirred and conveyed, so the temperature of the developer rises. Furthermore, as the speed of the image forming apparatus increases, the temperature of the developer inside tends to rise even more. Therefore, it becomes necessary to cool the developer, and some devices have a heat sink made of a highly thermally conductive material arranged in a part of a developing container that contains the developer, so as to efficiently dissipate the heat of the developer inside.

[0003] Such heat sinks are often formed mainly by extrusion or drawing, but because the processing costs are high, one method to reduce costs is to form multiple metal plates by pressing and then assemble them. However, when forming a heat sink by assembling multiple metal plates, joining the metal plates together becomes an issue.

[0004] 2. Description of the Related Art In joining metal plates together, various methods have been proposed for joining the ends of two metal plates in a state in which the ends of the plates are opposed to each other in a direction parallel to the plate surfaces.

[0005] For example, in Patent Document 1, multiple, approximately identical concave and convex shapes are formed on opposing metal plates, and after these concave and convex shapes are engaged, the plate surface of the convex part is pressed to form a concave shape on the plate surface. In the vicinity of the area where the concave shape is formed, the edge of the convex part protrudes outward. This protrusion protrudes toward the concave part of the mating metal plate, and a part of the edge of the concave part is recessed, so that they overlap in the plate thickness direction. By overlapping in the plate thickness direction in this way, dislocation in the plate thickness direction is prevented, and the two metal plates are joined.

[0006] In addition, in Patent Document 2, when a metal plate is cut with a cutting blade, the cut surface is composed of a sagging surface, a sheared surface, and a fractured surface, and the sheared surface has a shape that protrudes slightly from the fractured surface, and this is utilized to join the plates. Specifically, two metal plates cut to the same shape are overlapped and pressed together so that the sheared surface and the fractured surface face each other when joined, and the sheared surfaces overlap in the plate thickness direction, preventing them from coming apart in the plate thickness direction and joining the plates.

[0007] Furthermore, in Patent Document 3, which is mainly used for joining the end faces of cylindrical bodies, one end face is provided with a notch with an engaging portion on the inside, and the other end face is provided with a protrusion at a position corresponding to the notch, and the joining is achieved by bending the protrusion so that it catches on the engaging portion of the notch. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2003-80329 A [Patent Document 2] JP 2022-19419 A [Patent Document 3] WO2018 / 221601 publication Summary of the Invention [Problem to be solved by the invention]

[0009] However, when forming multiple uneven parts and joining them as in Patent Document 1, a space is required to form multiple uneven parts in the direction perpendicular to the direction in which the metal plates face each other. In addition, since the concave shapes formed on the sheet metal surface of the convex parts are all on the same plate surface side, the protrusions of the edges of the convex parts also face the same plate surface side. Therefore, the overlap in the plate thickness direction is in the same direction at all points, and in order to prevent the metal plates on one side from coming off when they are subjected to a force in the plate thickness direction, it is necessary to enlarge the joining area formed by the uneven shapes so that the forces applied on the concave side and the convex side are in opposite directions. For this reason, the joining part for joining two metal plates requires a large space in two directions, the direction in which the metal plates face each other and the direction perpendicular to that direction.

[0010] Furthermore, as in Patent Document 2, when two metal plates cut to the same shape are pressed together with their sheared surfaces facing each other to join them, the direction in which the two metal plates overlap in the thickness direction is the same as in Patent Document 1, so the joint needs to be made larger, as in Patent Document 1.

[0011] Furthermore, when joining is performed by bending the other protrusion so that it hooks onto a notch with an engagement part on the inside, as in Patent Document 3, joining in the plate thickness direction must be performed separately, and a space is required for the tool to bend the protrusion to enter. Therefore, a relatively large hole is created in the joined metal plates, including the part where the protrusion was located before it was bent.

[0012] In the case of heat sinks used in developing devices in electrophotographic image forming apparatuses, the developing devices must be made smaller as the image forming apparatus becomes more compact. However, the joining method requires a large joint, which is inefficient in terms of space and imposes significant design constraints.

[0013] In addition, since the heat sink itself also serves as part of the developing container, it also needs to have the function of sealing the developer inside. If a large hole were to be created at the joint, the degree of freedom in locating the joint would be limited, meaning that the joint could not be placed in the required location.

[0014] The present invention has been made in view of the above circumstances, and aims to provide a metal processed product, a heat dissipation member, and a developing device in an electrophotographic image forming apparatus, which can reduce the size of joints between metal plates. [Means for solving the problem]

[0015] In order to achieve the above-mentioned object, the present invention provides a metal processed product, a heat dissipation member, and a developing device in an electrophotographic image forming apparatus, characterized in that the first metal plate and the second metal plate respectively have a first end face and a second end face facing each other, the first end face has a protrusion protruding toward the second end face, and the second end face has a cutout portion having an engaging portion at least a portion of which engages with the protrusion at a position corresponding to the protrusion of the first end face, at least a portion of the protrusion contacts the engaging portion in the same shape as the engaging portion, and at least a portion of the protrusion overlaps in the plate thickness direction on both the front and back sides of the edge peripheral portion of at least a portion of the cutout. Effect of the Invention

[0016] According to the present invention, it is possible to provide a metal processed product, a heat dissipation member, and a developing device for an electrophotographic image forming apparatus, which can reduce the size of joints between metal plates. [Brief description of the drawings]

[0017] [Figure 1] 1 is a perspective view of a metal processed product according to a first embodiment of the present invention; [Diagram 2] FIG. 2 is a top view of the metalwork of FIG. 1 according to the first embodiment of the present invention; [Diagram 3] 2 is a cross-sectional view taken along line AA in FIG. 1 according to the first embodiment of the present invention. [Figure 4] FIG. 2 is a process diagram showing a processing process according to the first embodiment of the present invention. [Diagram 5] FIG. 2 is a top view of the first metal plate and the second metal plate after the first step according to the first embodiment of the present invention. [Figure 6]5A and 5B are a top view and a cross-sectional view showing an engagement state between a protrusion of a first metal plate and a notch of a second metal plate in a second step according to the first embodiment of the present invention. [Figure 7] FIG. 4 is a schematic diagram illustrating a pressing step including a mold in a third step according to the first embodiment of the present invention. [Figure 8] FIG. 11 is a perspective view of a metal processed product according to a second embodiment of the present invention. [Figure 9] FIG. 9 is a top view of the metalwork of FIG. 8 according to a second embodiment of the present invention; [Figure 10] 9 is a cross-sectional view taken along line CC in FIG. 8 according to the second embodiment of the present invention. [Figure 11] FIG. 6 is a process diagram showing a processing step according to a second embodiment of the present invention. [Figure 12] FIG. 11 is a schematic diagram illustrating a pressing step including a mold in a fourth step according to the second embodiment of the present invention. [Figure 13] FIG. 11 is a perspective view of another metal processed product according to the second embodiment of the present invention. [Figure 14] FIG. 11 is a top view of a metal processed product according to a third embodiment of the present invention. [Figure 15] FIG. 11 is a schematic front sectional view of an electrophotographic image forming apparatus according to a fourth embodiment of the present invention. [Figure 16] FIG. 11 is a schematic cross-sectional view of the periphery of a developing device according to a fourth embodiment of the present invention. [Figure 17] FIG. 11 is a perspective view of a completed heat sink according to a fourth embodiment of the present invention. [Figure 18] FIG. 11 is an exploded perspective view of a heat sink according to a fourth embodiment of the present invention. [Figure 19] FIG. 11 is a cross-sectional view of a heat sink according to a fourth embodiment of the present invention. [Figure 20] FIG. 11 is a perspective view of the vicinity of a connection portion of a heat sink according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. Note that the components described in the following embodiments are merely examples, and various conditions such as the configuration, function, dimensions, materials, shape, and relative arrangement of the device to which the present invention is applied can be appropriately modified or changed without departing from the spirit of the present invention, and the present invention is not limited to the following embodiments unless otherwise specified.

[0019] [First embodiment] FIG. 1 is a perspective view of a metal processed product according to a first embodiment of the present invention, and FIG. 2 is a top view of the metal processed product of FIG.

[0020] 1 and 2, a first metal plate 101 and a second metal plate 102 are both made of an aluminum alloy and are adjacent to each other and substantially parallel with their end faces 103, 105 facing each other. A protruding portion 104 protruding from end face 103 is formed on end face 103 of first metal plate 101, and a notched portion 106 is formed on end face 105 of second metal plate 102 at a position corresponding to protruding portion 104.

[0021] The first metal plate 101 is set to have a plate thickness slightly larger than that of the second metal plate 102, and the plate surface of the first metal plate 101 protrudes by an approximately equal amount from both the front and back plate surfaces of the second metal plate 102. In this embodiment, the thickness of the first metal plate 101 is set to 1 mm, and the thickness of the second metal plate 102 is set to 0.8 mm, so that the amount of protrusion of the first metal plate 101 from both the front and back plate surfaces of the second metal plate 102 is 0.1 mm.

[0022] FIG. 3 is a cross-sectional view taken along line AA in FIG.

[0023] As shown in Fig. 3, the thickness of a portion of the protruding portion 104 of the first metal plate 101 is slightly thinner than that of the other portion of the first metal plate 101. At least a portion of the protruding portion 104 of the first metal plate 101 and the notch portion 106 of the second metal plate 102 have a first joint portion 107 that contacts them in the same shape. The first metal plate 101 also has a first protruding shape 108 in which at least a portion of the protruding portion 104 of the first metal plate 101 protrudes so as to overlap (overlap) both the front and back sides of at least a portion of the edge peripheral portion of the notch portion 106 of the second metal plate 102 in the plate thickness direction. A portion of the first protruding shape 108 on the plate surface side of the second metal plate 102 is a second joint portion 109 that contacts the second metal plate 102 in the same shape.

[0024] Due to these joints, when the first metal plate 101 and the second metal plate 102 receive a force in a direction that separates the cross sections in a direction substantially parallel to the plate surfaces, the first metal plate 101 and the second metal plate 102 are prevented from separating by the frictional force and the minute projections and recesses on the surfaces of the first joint portion 107 and the second joint portion 109. Furthermore, when a force is applied to either the first metal plate 101 or the second metal plate 102 in a direction perpendicular to the plate surfaces, the first protruding shape 108 of the first metal plate 101 is caught by the plate surfaces on both the front and back sides of the second metal plate 102, so that the first metal plate 101 and the second metal plate 102 are prevented from separating.

[0025] Next, a method for processing the above-mentioned structure will be described.

[0026] FIG. 4 is a process diagram showing an outline of the processing steps.

[0027] In Fig. 4, in the first step, a punching process is performed to form the outer shapes of the first metal plate 101 and the second metal plate 102. Fig. 5(A) shows a top view of the first metal plate 101 after the first step, and Fig. 5(B) shows a top view of the second metal plate 102 after the first step. As shown in Fig. 5(A), the protruding portion 104 of the first metal plate 101 protrudes with a substantially constant width. Also, as shown in Fig. 5(B), the notch portion 106 of the second metal plate 102 is cut out with a substantially constant width similar to the protruding portion 104 so as to engage with the protruding portion 104.

[0028] The second step is an engagement step in which the protrusion 104 of the first metal plate 101 is engaged with the notch 106 of the second metal plate 102. Fig. 6(A) shows a top view of the state in which the protrusion 104 of the first metal plate 101 is engaged with the notch 106 of the second metal plate 102. Fig. 6(B) shows a cross-sectional view taken along line BB in Fig. 6(A).

[0029] As shown in Figures 6(A) and 6(B), the first metal plate 101 is supported by the second metal plate 102 so as to protrude from both the front and back plate surfaces by approximately the same amount. The protruding portion 104 of the first metal plate 101 and the notched portion 106 of the second metal plate 102 are engaged with an engagement clearance 110 which is a minute clearance, and the thickness of the protruding portion 104 of the first metal plate 101 is the same as the thickness of other portions of the first metal plate 101. When the protruding portion 104 of the first metal plate 101 is engaged with the notched portion 106 of the second metal plate 102, the first metal plate 101 and the second metal plate 102 can be engaged from any direction, such as a direction perpendicular to the plate surfaces of the metal plates or a direction parallel to the plate surfaces of the metal plates.

[0030] The third step is a pressing step in which the thickness of a portion of the protruding portion 104 of the first metal plate 101 is reduced by pressing. Fig. 7 shows a schematic diagram of the pressing step including the die in the third step.

[0031] 7(A), in the second step, the first metal plate 101 and the second metal plate 102 are set in the mold with the protruding portion 104 of the first metal plate 101 and the notched portion 106 of the second metal plate 102 engaged with each other. At this time, the first metal plate 101 and the second metal plate 102 are supported by the lower pressing plate 111 and the upper pressing plate 112, and the lower crimping punch 113 and the upper crimping punch 114 of the mold.

[0032] Next, as shown in FIG. 7B, the upper punch fixing plate 118 moves downward, and the upper crimping punch 114, the upper pressing plate 112, the first metal plate 101, and the second metal plate 102 move downward by being pressed by the upper punch fixing plate 118. At this time, since the spring force of the lower spring 115 is set lower than that of the upper spring 116, the lower spring 115 supporting the lower pressing plate 111 also contracts, and the lower pressing plate 111 also moves downward. On the other hand, the lower crimping punch 113 does not move downward because it is fixed and supported by the lower punch fixing plate 117, and the lower crimping punch 113 protrudes relatively to the protruding portion 104 of the first metal plate 101, and presses the lower portion of the protruding portion 104 of the first metal plate 101. Due to this pressing, the protruding portion 104 of the first metal plate 101 is deformed in a direction in which the plate thickness becomes thinner. As a result, excess material from the lower portion of the protrusion 104 of the first metal plate 101 is pushed out, filling the lower portion of the engagement clearance 110 to form the lower portion of the first joint 107, and at the same time, the peripheral edge of the protrusion 104 of the first metal plate 101 protrudes into the peripheral edge of the lower surface of the cutout portion 106 of the second metal plate 102 to form the underside of the first protruding shape 108.

[0033] Furthermore, when the upper punch fixing plate 118 moves downward, as shown in Figure 7 (C), the upper spring 116 in the upper mold contracts, and the upper crimping punch 114 protrudes against the protruding portion 104 of the first metal plate 101, thereby forming the upper portion of the first joint portion 107 and the upper portion of the first protruding shape 108 in the same manner as the lower portion.

[0034] The first protruding shapes 108 formed on both the upper and lower sides are pressed against the second metal plate 102 when pressed, so that a part of the portion in contact with the second metal plate 102 has the same shape as the second metal plate 102. By contacting with the same shape in this way, a second joint 109 is formed.

[0035] In this embodiment, the material of the first metal plate 101 and the second metal plate 102 is an aluminum alloy, the thickness of the first metal plate 101 is 1 mm, and the thickness of the second metal plate 102 is 0.8 mm. However, the material and thickness are not limited to these and may be a copper alloy, stainless steel, steel plate, etc.

[0036] Second Embodiment Next, a metal processed product according to a second embodiment of the present invention will be described. In this embodiment, the first metal plate and the second metal plate have substantially the same plate thickness (0.8 mm).

[0037] FIG. 8 is a perspective view of a metal processed product according to a second embodiment of the present invention, and FIG. 9 is a top view of the metal processed product of FIG.

[0038] In Figures 8 and 9, a first metal plate 201 and a second metal plate 202 are both made of an aluminum alloy, and similarly to the first embodiment, they are arranged close to each other and approximately parallel with their respective end faces 203, 205 facing each other, and a protrusion 204 and a cutout portion 206 are formed.

[0039] FIG. 10 is a cross-sectional view taken along line CC in FIG.

[0040] 10, as in the first embodiment, at least a portion of the protruding portion 204 of the first metal plate 201 and the notched portion 206 of the second metal plate 202 are in contact with each other in the same shape as in the first embodiment, and a first joint portion 207 is provided. In addition, in this embodiment, a concave shape 219 is provided on both sides of the ridgeline of at least a portion of the edge periphery of the notched portion 206 of the second metal plate 202, where the plate thickness becomes thinner toward the end. Furthermore, a recess 220 is provided on both sides of the plate surface of the protruding portion 204 of the first metal plate 201, where the plate thickness becomes thinner. At least a portion of the peripheral edge of the protrusion 204 of the first metal plate 201 forms a first protruding shape 208 that protrudes toward the concave shape 219 of the cutout portion 206 of the second metal plate 202 so as to overlap (overlap) both the front and back sides of the concave shape 219, and a portion of the first protruding shape 208 forms a second joint 209 that contacts the concave shape 219 of the second metal plate 202 in the same shape.

[0041] When the first metal plate 201 and the second metal plate 202 are subjected to a force that separates them in a direction approximately parallel to the plate surfaces, the first joint 207 and the second joint 209 prevent the first metal plate 201 and the second metal plate 202 from separating due to the frictional force and the minute projections and recesses on the respective surfaces that catch on each other. Also, when either the first metal plate 201 or the second metal plate 202 is subjected to a force in a direction perpendicular to the plate surfaces, the first protruding shape 208 of the first metal plate 201 is caught by the recessed shape 219 of the cutout portion 206 of the second metal plate 202, thereby preventing the first metal plate 201 and the second metal plate 202 from separating.

[0042] Next, a method for processing the above-mentioned structure will be described.

[0043] FIG. 11 is a process diagram showing an outline of the processing steps.

[0044] In FIG. 11, the first step is omitted since it is the same as in the first embodiment.

[0045] The second process is a face-chamfering process for forming a concave shape 219 on a part of the ridgeline of the edge periphery of the cutout portion 206 of the second metal plate 202 in a direction in which the plate thickness becomes thinner toward the end. In the face-chamfering process, the concave shape 219 is often formed on a part of the ridgeline of the surface that will become the punch burr side, but the concave shape 219 may also be formed on the ridgeline on the punch sagging side.

[0046] The third step is an engagement step in which the protrusion 204 of the first metal plate 201 is engaged with the notch 206 of the second metal plate 202. This engagement step is similar to the engagement step in the first embodiment, but since the plate thicknesses of the first metal plate 201 and the second metal plate 202 are approximately the same, both the front and back surfaces of the first metal plate 201 and the second metal plate 202 are aligned to be approximately the same.

[0047] The fourth step is a pressing step for forming the recesses 220 in the protrusions 204 of the first metal plate 201. Fig. 12 shows a schematic diagram of the pressing step including the mold in the fourth step.

[0048] 12(A), in the second step, the protrusion 204 of the first metal plate 201 and the notch 206 of the second metal plate 202 are set in the die in an engaged state. At this time, the first metal plate 201 and the second metal plate 202 are supported by a lower pressure plate 211 and an upper pressure plate 212, and a lower crimping punch 213 and an upper crimping punch 214, and both plate surfaces of the first metal plate 201 and the second metal plate 202 are supported in a substantially flush state.

[0049] 12(B), the die moves downward in the same manner as in the first embodiment, and the lower crimping punch presses the protruding portion 204. A part of the protruding portion 204 of the first metal plate 201 pressed by the lower crimping punch 213 is deformed in a direction in which the plate thickness becomes thinner, and a lower recess 220 is formed. The excess material created by the formation of the lower recess 220 is pushed out from the protruding portion 204, filling in the lower part of the engagement clearance 210 to form the lower part of the first joint portion 207, and at the same time, the lower side of the first protruding shape 208 is formed by protruding toward the recessed shape 219 at the edge periphery of the lower surface of the cutout portion 206 of the second metal plate 202.

[0050] 12(C), the protruding portion 204 of the first metal plate 201 is pressed by the upper crimping punch 214, and an upper recess 220 is formed in the same manner as the lower portion. The excess material created by forming the upper recess 220 forms the upper portion of the first joint 207 and the upper first protruding shape 208 in the same manner as the lower portion. The first protruding shapes 208 formed on both the upper and lower sides are pressed against the second metal plate 202 when pressed, so that a part of the portion in contact with the second metal plate 202 has the same shape as the second metal plate 202, and a second joint 209 is formed.

[0051] In this embodiment, the first metal plate 201 and the second metal plate 202 are described as being made of aluminum alloy and both have a thickness of 0.8 mm, but the material and thickness are not limited to these and may be copper alloy, stainless steel, steel plate, etc.

[0052] Furthermore, the first metal plate 201 and the second metal plate 202 are not limited to being different metal plates, and may be surfaces formed by bending the same metal plate multiple times, as shown in Fig. 13. In this case, the joining according to this embodiment has the effect of reinforcing the bending of each other, making it possible to form a bent shape with higher rigidity. As shown in Fig. 13, the end faces of the metal plate described in this embodiment may be not only end faces formed by the punching process of the metal plate, but also surfaces formed by bending.

[0053] Third Embodiment Next, a metal processed product according to a third embodiment of the present invention will be described. The feature of this embodiment is that the shape of the notch 206 of the second metal plate 202 is different from that of the second embodiment. In the following description, the same components as those of the second embodiment are denoted by the same reference numerals. FIG. 14(A) is a top view of a metal processed product according to the third embodiment of the present invention.

[0054] 14(A), the notch 206 of the second metal plate 202 includes an engagement portion 224 that engages with the protrusion 204 of the first metal plate 201 in the width direction, and a separation portion 221 that is wider than the engagement portion 224 in the width direction of the protrusion 204 of the first metal plate 201 at a position closer to the tip of the protrusion 204 than the engagement portion 224 with respect to the protrusion 204 of the first metal plate 201 that engages with the protrusion 204 of the first metal plate 201. The protrusion 204 of the first metal plate 201 includes a second protrusion shape 222 that protrudes toward the separation portion 221 in addition to the first protrusion shape 208 formed in the same manner as in the second embodiment, and at least a part of the second protrusion shape 222 is in contact with a part of the separation portion 121 in the same shape, thereby forming a third joint portion 223.

[0055] The processing steps in this embodiment are the same as those in the second embodiment. Fig. 14(B) is a top view showing a state in which the protrusion 104 of the first metal plate 201 and the notch 106 of the second metal plate 202 are engaged with each other in the third step.

[0056] 14(B), the protruding portion 204 of the first metal plate 201 protrudes with a substantially constant width having a minute engagement clearance 210 with the engagement portion 224 of the notch portion 206 of the second metal plate 202. Therefore, in the process of the first metal plate 201 and the second metal plate 202 engaging with each other, the first metal plate 201 and the second metal plate 202 can engage with each other in any direction, such as a direction perpendicular to the metal plates or a direction parallel to the plate surfaces of the metal plates.

[0057] The next fourth step is also similar to that of the second embodiment, but the excess material pushed out by the formation of the recess 220 fills the engagement clearance 210 and at the same time protrudes in the direction of the recessed shape 219 and the spaced apart portion 221, forming a second protruding shape 222 in addition to the first protruding shape 208. Since a part of the second protruding shape 222 is pressed against the spaced apart portion 221, a third joint portion 223 is formed in a part of the portion that contacts the spaced apart portion 221.

[0058] When the first metal plate 201 and the second metal plate 202 are subjected to a force that separates them in a direction approximately parallel to the plate surfaces, the second protruding shape 222 provides an interference fit in addition to the frictional force and snagging caused by the minute surface irregularities generated at the first joint 207 and the second joint 209, making it possible to suppress separation even in the face of a stronger force than in the first and second embodiments.

[0059] [Fourth embodiment] Next, a developing device in an electrophotographic image forming apparatus using a heat dissipation member made of a metal processed product according to a fourth embodiment of the present invention will be described.

[0060] FIG. 15 is a schematic front sectional view of an electrophotographic image forming apparatus according to a fourth embodiment of the present invention.

[0061] 15, image forming apparatus 300 is an electrophotographic full-color laser printer. Image forming apparatus 300 forms toner images of four different colors, yellow, magenta, cyan, and black, through processes of charging, exposing, developing, and transferring, using first, second, third, and fourth image forming units Py, Pm, Pc, and Pk arranged side by side inside image forming apparatus 300.

[0062] Reference numeral 19 denotes a control unit serving as a control means. The control unit 19 is composed of a CPU and memories such as ROM and RAM. When the control unit 19 receives a print command signal output from an external device (not shown) such as a host computer, the control unit 19 sequentially operates the image forming units Py, Pm, Pc, and Pk in accordance with an image formation control sequence stored in the memory.

[0063] In each of the image forming portions Py, Pm, Pc, and Pk, the photosensitive drums 1y, 1m, 1c, and 1k serving as image carriers are rotated at a predetermined peripheral speed (process speed).The intermediate transfer belt 7, which is stretched across a driving roller 6a, a driven roller 6b, and a tension roller 6c so as to straddle the photosensitive drums 1y, 1m, 1c, and 1k of each of the image forming portions Py, Pm, Pc, and Pk, is rotated in the direction of arrow L by the driving roller at a peripheral speed corresponding to the rotation peripheral speed of each of the photosensitive drums 1.

[0064] Then, in the image forming station Py for the first color, yellow, the outer peripheral surface (surface) of the photosensitive drum 1y is uniformly charged to a predetermined polarity and potential by the charger 2y. Next, the exposure device 3y scans and exposes the charged surface of the photosensitive drum 1y with laser light generated based on image information from an external device. As a result, an electrostatic latent image according to the image information is formed on the charged surface of the photosensitive drum 1y. Then, the developing device 4y develops this electrostatic latent image using yellow toner (developer), and a yellow toner image (developed image) is formed on the surface of the photosensitive drum 1y.

[0065] Similar charging, exposure, and development processes are also performed in the magenta image forming unit Pm, the cyan image forming unit Pc, and the black image forming unit Pk, which are the second and third colors, respectively. Note that the components of the magenta image forming unit Pm, the cyan image forming unit Pc, and the black image forming unit Pk corresponding to the yellow image forming unit Py are shown by replacing the suffix "y" of the reference numerals given to the components of the yellow image forming unit Py with m, c, and k, and their explanations will be omitted.

[0066] The toner images of each color formed on the surfaces of the photosensitive drums 1y, 1m, 1c, 1k in the image forming units Py, Pm, Pc, Pk are transferred in sequence onto the outer circumferential surface (surface) of the intermediate transfer belt 7 by primary transfer rollers (transfer members) 8y, 8m, 8c, 8k arranged opposite the photosensitive drums 1y, 1m, 1c, 1k with the intermediate transfer belt 7 interposed therebetween. As a result, a full-color toner image is formed on the surface of the intermediate transfer belt 7. After the toner images are transferred to the photosensitive drums 1y, 1m, 1c, 1k, residual toner remaining on the surfaces of the photosensitive drums 1y, 1m, 1c, 1k is removed by drum cleaners 5y, 5m, 5c, 5k, and the photosensitive drums 1y, 1m, 1c, 1k are used for the next image formation.

[0067] Meanwhile, the recording material P is transported from the feeding cassette 10 by the delivery roller 11 through the transport path 12a to the registration roller 13. The recording material P is then transported by the registration roller 13 to the secondary transfer nip portion Tn between the intermediate transfer belt 7 and the secondary transfer roller 14. The recording material P is then nipped and transported in the secondary transfer nip portion Tn, and during this transport process, the toner image on the surface of the intermediate transfer belt 7 is transferred onto the recording material P by the secondary transfer roller 14. After the toner image is transferred, residual toner remaining on the surface of the intermediate transfer belt 7 is removed by the belt cleaner 9 from the intermediate transfer belt 7, and the intermediate transfer belt 7 is prepared for the next image formation.

[0068] The recording material P carrying the unfixed toner image transferred from the intermediate transfer belt 7 by the secondary transfer roller 14 is introduced into the nip portion of the fixing device 15 with the image carrying surface facing up. The recording material P is then sandwiched and conveyed through the nip portion of the fixing device 15, whereby the toner image is heated and fixed onto the recording material P.

[0069] When an image is formed on only one side of the recording material P, the recording material P discharged from the fixing device 15 is guided to a discharge roller 17 by a switching flapper 16 and discharged onto a discharge tray 18 provided on the side of the image forming device 300.

[0070] When images are formed on both sides of the recording material P, the recording material P discharged from the fixing device 15 is guided to the lower reversing conveying path 12b by the switching flapper 16. When the trailing end of the recording material P reaches the reversing point Rp, the recording material P is switched back in the reversing conveying path 12b, and is sent to the double-sided conveying path 12c with the image bearing surface facing up.

[0071] In the double-sided conveying path 12c, the recording material P is conveyed through the conveying path 12a to the registration rollers 13. The recording material P is conveyed to the secondary transfer nip portion Tn by the registration rollers 13, and is sandwiched and conveyed in the secondary transfer nip portion Tn. During this conveying process, the toner on the surface of the intermediate transfer belt 7 is transferred onto the recording material P by the secondary transfer rollers 14.

[0072] The recording material P carrying the unfixed toner image transferred from the intermediate transfer belt 7 by the secondary transfer roller 14 is introduced into the nip portion of the fixing device 15 with the image carrying surface facing up. The recording material P is then sandwiched and conveyed through the nip portion of the fixing device 15, whereby the toner image is heated and fixed onto the recording material P. The recording material P discharged from the fixing device 15 is guided by a switching flapper 16 to discharge rollers 17 and discharged onto a discharge tray 18.

[0073] FIG. 16 is a schematic cross-sectional view of the developing device 4 (4y, 4m, 4c, 4k) and its surroundings.

[0074] 16, the developing device 4 includes a developing container 40 that contains a developer as a housing, and rotatably supports a first screw 41, a second screw 42, and a third screw 43 that are disposed in the developing container. The first screw 41, the second screw 42, and the third screw 43 agitate and transport the developer inside the developing container 40.

[0075] A first developing roller 44 and a second developing roller 45 are disposed on the surface of the developing container 40 facing the photosensitive drum 1 (1y, 1m, 1c, 1k), and a developing blade 47 is provided at a predetermined distance from the developing roller 44 at a position upstream of the photosensitive drum facing surface of the first developing roller 44. The developer transported by the second screw 42 and the first screw 41 is transported along the surface of the first developing roller 44 and is limited to a predetermined thickness by the developing blade 47, and then faces the photosensitive drum 1 to develop the electrostatic latent image drawn on the surface of the photosensitive drum 1.

[0076] The developer remaining on the first developing roller 44 is transported by the first developing roller 44, then handed over to the second developing roller 45, and transported along the surface of the second developing roller 45, and then collected between the second developing roller 45 and the collection roller 46 into the developing container 40. The developer collected in the developing container 40 is stirred and transported by the third screw 43 and the second screw 42, and is handed over to the first screw 41.

[0077] A temperature sensor 48 is disposed below the developing container 40 at a position facing the developer being stirred and transported by the second screw 42 , and detects the temperature of the developer in the developing container 40 .

[0078] A heat sink 400 is disposed on the upper part of the developing device 4 as a heat dissipating member made of a material having a higher thermal conductivity than the developing container. A contact surface 401 of the heat sink 400 facing the inside of the developing container 40 comes into contact with the developer transported from the first screw 41 toward the developing roller 44 at the upper part of the first screw 41, and exchanges heat. The heat received from the developer is transferred by thermal conduction to a heat dissipating surface 402 of the heat sink 400 facing the outside of the developing container, and is cooled by heat exchange with an airflow introduced from outside the main body of the apparatus. A plurality of fins 403 and 404 are disposed on the heat dissipating surface 402 of the heat sink 400 to increase the surface area, and the increased surface area increases the efficiency of heat exchange.

[0079] A duct wall 501 is disposed at a position facing a heat sink 400 inside the image forming apparatus. A duct top surface 502 is provided on the upper surface of the duct wall 501, and duct side walls 503, 504 are disposed on both ends of the duct top surface 502 in a direction perpendicular to the extension direction of the fins 403, 404. The duct side walls 503, 504 are in contact with duct joint walls 405, 406 provided on the sides of the heat sink 400, with flexible seal materials 407, 408 attached to the duct joint walls 405, 406 sandwiched therebetween. A space 504 serving as a duct is formed inside by the duct top surface 502 and the duct side walls 503, 504, and by the heat dissipation surface 402 of the heat sink 400 and the duct joint walls 405, 406. The heat sink 400 dissipates heat received from the developer by passing an air current introduced from outside the image forming apparatus main body through the space 504. In this embodiment, the air current flows from the front to the back of the page in FIG.

[0080] Next, we will explain the configuration of the heat sink 400. The heat sink 400 is constructed by combining and bonding a plurality of metal plates formed by pressing.

[0081] FIG. 17 is a perspective view of the heat sink 400 in a completed state, and FIG. 18 is an exploded perspective view of the heat sink 400 in FIG. 17 disassembled into its individual components.

[0082] 17 and 18, the heat sink 400 is composed of three metal plates: a base member 410 that forms the bottom of the heat sink 400, a first side wall member 411 that forms the side walls and fins for heat dissipation, and a second side wall member 412.

[0083] In order to increase the contact area with the developer, the base member 410 has a heat receiving portion 414 formed by step bending relative to the mounting portion 413 so as to enter the inside of the developing device. When the base member 410 is attached to the developing device 4, the surface of the heat receiving portion 414 on the developer side becomes the contact surface 401 shown in Fig. 16, and the surface on the air flow side becomes the heat dissipation surface 402 shown in Fig. 16. In addition, a connection portion 415 that connects the mounting portion 413 formed by bending and the heat receiving portion 414 is formed in a direction approximately perpendicular to the mounting portion 413 and the heat receiving portion 414.

[0084] The fins 403 and first sidewall 416 of the first sidewall member 411 and the fins 404 and second sidewall 417 of the second sidewall member 412 are arranged so as to be approximately perpendicular to the heat receiving portion 414 and connecting portion 415 of the base member 410. Both ends of the first sidewall 416 contact the connecting portion 415, and both ends of the second sidewall 417 contact the connecting portion 415 via bent surfaces 418 formed by bending the fins 404 of the second sidewall member. In this way, the connecting portion 415 and the sidewalls do not necessarily need to be in direct contact with each other, and a member may be interposed therebetween.

[0085] The first side wall member 411 further has a top surface portion 419 that is approximately flush with the mounting portion 413 of the base member 410, and the mounting portion 413 and the top surface portion 419 form a flange surface that serves as a lid when the heat sink 400 is attached to the developing container 40.

[0086] The heat sink 400 used in the developing device 4 is formed as a part of the developing container 40, and therefore needs to be sealed so as not to leak the developer to be cooled to the outside. Therefore, the joints between the base member 410, the first side wall member 411, and the second side wall member 412 need to be in close contact with each other so as not to leak the developer.

[0087] FIG. 19 is a cross-sectional view of the heat sink 400.

[0088] 19, bottom surfaces 420, 421 of the first side wall member 411 and the second side wall member 412 are joined to the heat receiving portion 414 of the base member 410 by crimping portions 421, 422. The crimping portions 421, 422 are crimped so as not to create holes so that the developer does not leak. Since the heat receiving portion 414 extends in the longitudinal direction of the developing device, the crimping portions 421, 422 can be arranged in a plurality of locations. This allows the heat receiving portion 414 and the bottom surfaces 420, 421 of the first side wall member 411 and the second side wall member 412 to adhere relatively firmly to each other.

[0089] Next, a method for closely bonding the connection portion 415 to the first side wall 416 and the second side wall 417 will be described.

[0090] FIG. 20 is a perspective view of the vicinity of the connection portion 415 of the heat sink 400. As shown in FIG.

[0091] 20, first side wall 416 is disposed so that its end face contacts connecting portion 415, and second side wall 417 contacts connecting portion 415 via bent surface 418. Top surface portion 419 is adjacent to mounting portion 413 with their end faces facing each other. Top surface portion 419 has protruding portion 422 that protrudes from top surface portion 419 toward mounting portion 413, and engages with notch portion 423 provided in mounting portion 413 at a position corresponding to protruding portion 422.

[0092] The cutout portion 423 includes an engagement portion 424 that engages with the protrusion 422, and a separation portion 425 that is wider than the engagement portion 424 in the width direction of the protrusion 422 at a position on the tip side of the engagement portion 424 of the protrusion 422 that engages with it. In addition, a concave shape 426 is provided on both sides of the ridge line of at least a part of the edge periphery of the cutout portion 423, the plate thickness of which is reduced toward the end. A recess 427 is provided on a part of both the front and back sides of the protrusion 422. As in the third embodiment, at least a part of the edge periphery of the protrusion 422 includes a first joint portion having the same shape as the cutout portion 423, a first protruding shape 429 that protrudes so as to overlap (overlap) both the front and back sides of the concave shape 426 so that at least a part of the shape is the same as the concave shape 426, and a second protruding shape 430 that protrudes so as to have the same shape as the separation portion 425. A first protruding feature 429 defines a second junction, and a second protruding feature 430 defines a third junction.

[0093] The protrusion 422 and the notch 423 are joined by the first joint, the second joint, and the third joint. This prevents the attachment portion 413 and the top surface 419 from moving apart. The heat receiving portion 414 and the bottom surfaces 420 and 421 are also joined by crimping portions.

[0094] If there is no connection between the mounting portion 413 and the top surface portion 419, the support of the bend 432 between the heat receiving portion 414 and the connecting portion 415 is only due to work hardening caused by the bending process, and the bend 432 is easily deformed even with a small force. For example, if the bend 432 is deformed in the opening direction, a gap is created between the connecting portion 415 and the first side wall 416, which may cause the developer inside to leak.

[0095] Furthermore, when a force is applied to the bend 432 in an opening direction, the top surface 419 would be pulled together with the bend 432 if only the joint between the mounting portion 413 and the top surface 419 was not sufficient, but the side wall 416 formed approximately perpendicular to the connection portion 415 and the joint between the bottom surface 420 and the heat receiving portion 414 allow the top surface 419 to withstand deformation. This, in addition to the joint between the protrusion 422 and the notch 423 by the first joint, the second joint, and the third joint, makes it possible to prevent the bend 432 from succumbing to the force and deforming.

[0096] Regarding the second side wall member 412 and the connecting portion 415, since the bend 432 is reinforced by joining the mounting portion 413 and the top surface portion 419, it is not necessarily required to join them.

[0097] Heat sinks are often made of aluminum alloys, which have high thermal conductivity. Because aluminum alloys are relatively soft materials, for example, when assembling a heat sink, a strong force is applied to the mounting surface, which can cause the bent parts that form the connection to deform, creating a gap between the connection and the side wall. If developer leaks out from the gap, it can contaminate the inside of the image forming device, which can cause poor images and breakdowns.

[0098] In contrast, the configuration of this embodiment makes it possible to join the mounting portion 413 and the top surface portion 419 with a small space, and reinforces the bending. By suppressing bending deformation with a small space, the heat sink can be sealed with multiple metal plates formed by pressing. [Explanation of symbols]

[0099] 4...Developing device 101…first metal plate 102...second metal plate 103...end face 104...Protrusion 105...End face 106…Notch 107…First joint 108…First protruding shape 109…Second joint 110…Engagement clearance 201…First metal plate 202...Second metal plate 203...End face 204...Protrusion 205...End face 206…Notch 207…First joint 208…First protruding shape 209…Second joint 210…Engagement clearance 219…Concave shape 220…Recess 221...Separation part 222…Second protruding shape 223…Third junction 224...Engagement portion 400…Heat sink 422...Protruding part 424…Notch 425…Separation part 426…Concave shape

Claims

1. A first metal plate; A second metal plate; the first metal plate and the second metal plate each have a first end surface and a second end surface facing each other, the first end surface includes a protrusion protruding toward the second end surface, the second end surface includes a notch having an engagement portion at a position corresponding to the protrusion of the first end surface, the engagement portion being at least partially engaged with the protrusion; A metal processed product characterized in that at least a portion of the protrusion contacts the engaging portion in the same shape, and at least a portion of the protrusion overlaps in the thickness direction of the plate with both the front and back sides of the edge peripheral portion of at least a portion of the cutout portion.

2. The second metal plate has a recessed shape recessed in a plate thickness direction on a part of a ridge line of an edge peripheral portion on both sides of the front and back of the cutout portion, 2. The metal processed product according to claim 1, wherein at least a part of the protruding portion of the first metal plate is in contact with the concave shape in the same shape.

3. The second metal plate has a recessed shape recessed in a direction in which the plate thickness becomes thinner toward the end portion on a part of a ridge line of the peripheral portion of the front and back sides of the notch portion of the second metal plate, 2. The metal processed product according to claim 1, wherein at least a part of the protruding portion of the first metal plate is in contact with the concave shape in the same shape.

4. the second metal plate is provided with a separation portion in the notch portion, the separation portion being wider than the engagement portion; 4. The metal processed product according to claim 2, wherein at least a part of the protruding portion of the first metal plate is in contact with the spaced portion in the same shape as the spaced portion.

5. the second metal plate is provided with a separation portion in the notch portion, the separation portion being wider than the engagement portion; 2. The metal processed product according to claim 1, wherein at least a part of the protruding portion of the first metal plate is in contact with the spaced portion in the same shape as the spaced portion.

6. 2. The metal processed product according to claim 1, wherein the first metal plate has a recess in a direction in which the plate thickness becomes thinner on both sides of the plate surface of the protruding portion.

7. 2. The metal processed product according to claim 1, wherein the metal processed product is made of an aluminum alloy or a copper alloy.

8. A heat dissipation member comprising the metal processed product according to claim 1.

9. A developing device in an electrophotographic image forming apparatus, comprising the heat dissipating member according to claim 8.

Images