JP2017028066A - Radiator, radiation unit and image formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost and space-saving radiator with secured safety without adding extra bending and deburring pressing.SOLUTION: A radiator 50 includes, as depicted in Fig. 5(a), a plurality of radiation fins 58 as a first radiation plate and a radiation fin 62 as a second radiation plate positioned at the bottom. The radiation fin 58 includes at both end parts a bent piece 58a which is bent to the same direction. The radiation fin 62 includes a bent piece 62a which is bent to the opposite direction to the radiation fin 58. Symbols 58b, 62b indicate insertion holes through which a heat pipe 48 is inserted. A compact formation can be achieved by a size h in comparison with the prior configuration depicted in Fig. 5(b), and the edge of the bent piece 58a of the radiation fin 58 at the bottom is not exposed to a protrusion state, which enables improved safety.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a heat radiator, a heat radiating unit, and an image forming apparatus.

A large amount of heat is released from the fixing device used in the electrophotographic image forming apparatus. However, when the exhaust heat is transmitted to other image forming units, the drive system locks due to toner fluidity deterioration, and the toner Various problems such as sticking and image deterioration occur.
For this reason, a heat radiating unit for quickly radiating the exhaust heat from the fixing device to the outside of the device is mounted.
The heat radiating unit is generally composed of a shielding plate made of sheet metal such as aluminum, a radiator disposed in the air duct for quickly radiating heat to the outside, and the heat absorbed by the shielding plate. It is comprised from the heat pipe etc. for transmitting quickly to the several radiation fin to do.

Conventionally, heat sinks by extrusion molding of aluminum have been widely used, but there is a problem that the cost is high, and recently, as disclosed in Patent Document 1, low-priced thin sheet metal radiating fins are stacked. A system that constitutes a radiator is adopted.
Each radiating fin has a shape in which both end portions of the sheet metal are bent, and by stacking the radiating fins using the bent pieces as spacing members, a cylindrical space is formed between the radiating fins, and the heat radiation promoting action by the chimney effect is achieved. There is an advantage that strength is maintained while being obtained.
The heat pipe is provided so as to penetrate the flat portion of each radiating fin in the thickness direction.

In a radiator of the type in which the radiating fins having both ends bent are laminated, all the radiating fins are laminated in the same direction, so that the radiating fin located at the uppermost end or the lowermost end as shown in FIG. The bent portion will jump out to the outside without being covered with other radiating fins.
In this case, the radiating fins located at the uppermost end or the lowermost end do not contribute to the formation of the cylindrical space, so that a space is wasted from the viewpoint of the effective area of the air duct.
In addition, since the heat dissipation fin is formed by pressing a thin sheet metal, the edge of the bent part is sharp, and it is easy for the operator to touch the edge if the bent part is exposed to the outside. There are safety issues.
In order to prevent this, post-processing such as extra bending to hide the edge inside and surface pressing to reduce the sharpness of the edge has been performed. Therefore, there has been a problem that the efficiency of material acquisition is low and the cost is high, and the processing efficiency is low.

  The present invention has been made in view of such a current situation, and provides a heat radiator that is inexpensive and saves space while ensuring safety without requiring additional bending or surface pressing. Is its main purpose.

  In order to achieve the above object, the heat radiator of the present invention is laminated with one or a plurality of rod-shaped heat conductive members, in a state of crossing in the longitudinal direction of the heat conductive members, A plurality of first heat radiating plates having bent pieces extending in the laminating direction at both ends, and a second heat radiating layer that is inserted together with the first heat radiating plate through the heat conducting member in the same manner as the first heat radiating plate. A first heat radiating plate is stacked in a state where a space is held between the bent pieces so that a cylindrical space exists between the first heat radiating plates, and the second heat radiating plate is: The first heat radiating plate is laminated so that the end faces of the bent pieces do not come into contact with each other, and has a shape that forms the cylindrical space with the first heat radiating plate.

  According to the present invention, it is possible to provide a heatsink that is inexpensive and saves space while ensuring safety without requiring extra bending or surface pressing.

1 is a schematic configuration diagram of a color copying machine as an image forming apparatus according to a first embodiment of the present invention. It is a perspective view of a thermal radiation unit. FIG. 3 is a perspective view of the shielding panel in the shape of FIG. 2 as viewed from the fixing device side. It is a perspective view of the radiation fin as a 1st heat sink. It is a side view of a radiator, (a) is a figure which shows the structure of this invention, (b) is a figure which shows a conventional structure. It is a side view which shows the modification of a heat radiator. It is a partially omitted side view showing a modification of the radiator. It is a side view of the heat radiator which concerns on 2nd Embodiment, (a) is the comparison block diagram shown in 1st Embodiment, (b) is a block diagram of this embodiment. It is a side view of the heat radiator which concerns on 3rd Embodiment. It is a side view of the heat radiator which concerns on 4th Embodiment, (a) is a figure which shows an example, (b) is a figure which shows a modification.

Embodiments of the present invention will be described below with reference to the drawings.
1 to 7 show a first embodiment. First, a schematic configuration of a tandem type color copying machine 2 as an image forming apparatus according to the present embodiment will be described with reference to FIG.
A reading unit 6 is disposed above the apparatus body 4 of the color copying machine 2, and two exposure means 8 and 10 are disposed below the reading unit 6. Below the exposure means 8 and 10, four process units 12Y, 12M, 12C and 12K as image forming units are arranged. Y, M, C, and K indicate that the toner colors are yellow, magenta, cyan, and black, respectively.

The process unit 12Y for forming a yellow toner image has a photosensitive drum 14 as an image carrier, and around the photosensitive drum 14, a charging unit 15, a developing unit 16, a cleaning unit 17, and a lubricant applying unit. 18 etc. are arranged.
The other process units 12M, 12C, and 12K have the same configuration. The process units 12Y, 12M, 12C, and 12K are process cartridges that are detachable from the apparatus main body 4.
The process units 12Y and 12M are irradiated with exposure light from the exposure unit 8 to form an electrostatic latent image on the photosensitive drum 14, and the process units 12C and 12K are irradiated with exposure light from the exposure unit 10 and the photosensitive drum. An electrostatic latent image is formed at 14.

An intermediate transfer unit 20 is disposed below the process unit. The intermediate transfer unit 20 includes an intermediate transfer belt 22, support rollers 24, 25, and 26 that rotatably support the intermediate transfer belt 22, a tension roller 27, a belt cleaning unit 28, and the like.
Inside the intermediate transfer belt 22, primary transfer rollers 29Y, 29M, 29C, and 29K are arranged facing the photosensitive drums 14 of the process units 12Y, 12M, 12C, and 12K.

A secondary transfer roller 30 is disposed opposite the support roller 26 with the intermediate transfer belt 22 interposed therebetween.
A plurality of paper feed trays 32 are arranged in the lower part of the apparatus main body 4, and the transfer paper as a recording medium fed from any one of the paper feed trays 32 is temporarily stopped by a pair of registration rollers 34 to be obliquely displaced. Will be corrected.
The toner images formed on the photosensitive drums 14 of the process units 12Y, 12M, 12C, and 12K are transferred onto the intermediate transfer belt 22 by the primary transfer rollers 29 and transferred to the secondary transfer portion at a predetermined timing. A batch transfer is performed by the secondary transfer roller 30 onto the supplied transfer paper.

  The transfer paper onto which the superimposed toner image has been transferred is conveyed by the belt conveying means 36 and enters the fixing device 38, where heat and pressure are applied to fix the unfixed toner image. After the fixing, the transfer paper is discharged out of the apparatus main body by a pair of paper discharge rollers 40 or conveyed to a refeed unit 42 to form an image on the back surface.

When the image forming apparatus is in operation, a large amount of heat is released from the fixing device 38 during standby. When the exhaust heat is transmitted to the intermediate transfer unit 20 and the process unit 12 located in the vicinity of the fixing device 38, various problems such as drive system locking due to toner fluidity deterioration, toner adhesion, and image deterioration occur.
In order to solve this problem, a heat radiating unit 44 is disposed above the fixing device 38 to discharge heat from the fixing device 38 to the outside and suppress heat transfer to the intermediate transfer unit 20 and the process unit 12. ing.

As shown in FIG. 2, the heat radiating unit 44 includes a shielding panel 46 disposed so as to partition a space between the fixing device 38 as a heat generation source and the intermediate transfer unit 20 and the process unit 12 as other members. A plurality of heat pipes 48 as rod-like heat conducting members fixed to the surface of the shielding panel 46 facing the fixing device 38, a radiator 50 integrally formed with these heat pipes 48, and the shielding panel 46 A heat absorption panel 52 as a heat absorption member provided so as to cover the heat pipe 48 on a surface facing the fixing device 38, a cooling duct 54, a cooling fan 56, and the like are provided.
In this embodiment, the cooling duct 54 and the cooling fan 56 are provided only on the downstream side in the exhaust direction of the radiator 50, but may be provided on the upstream side. In this case, only the cooling fan 56 may be provided on the upstream side.

FIG. 3 is a view of the shielding panel 46 as seen from the fixing device 38 side, and the bent shape is shown as in FIG. 2 for easy understanding.
As shown by the dot display, the heat absorption panel 52 is disposed only in a portion facing the fixing device 38 in the entire shielding panel 46. In other words, it is disposed only in a portion that can efficiently absorb the exhaust heat from the fixing device 38.

FIG. 4 shows a heat radiation fin 58 as a first heat radiation plate constituting the heat radiator 50. The heat radiating fins 58 are formed of thin metal plates, and bent pieces 58a that are bent in the same direction are formed at both ends.
A plurality of insertion holes 58b are formed in the central portion of the radiating fins 58 by burring so as to be inserted into the heat pipe 48 at intervals in the longitudinal direction. The number of the insertion holes 58b corresponds to the number of the heat pipes 48, and is formed so as to protrude on the side opposite to the bent piece 58a.
As a material of the heat radiation fin 58, an aluminum alloy plate or a copper plate is desirable from the viewpoint of thermal conductivity.

As shown in FIG. 5A, the radiator 50 has a configuration in which a plurality of radiating fins 58 are inserted into a heat pipe 48 and stacked in the same direction. In other words, the radiating fins 58 are stacked in a state of crossing (orthogonal) in the longitudinal direction of the heat pipe 48.
The bent piece 58 a of each radiating fin 58 is in contact with the upper surface of the adjacent radiating fin 58, that is, the surface opposite to the bent piece 58 a, and a cylindrical space 60 having a rectangular cross section is formed between the radiating fins 58. Has been.

That is, the 1st heat sink is laminated | stacked in the state by which the space | interval was hold | maintained by the bending piece so that a cylindrical space might exist between 1st heat sinks.
The space between the heat dissipating fins 58 is held in the stacking direction by bent pieces 58a. The bent piece 58a of each radiating fin 58 and the upper surface of the adjacent radiating fin 58 are not fixed, but are merely in contact with each other.

The insertion hole 58b is formed by burring as shown by the uppermost heat radiation fin 58, and the heat pipe 48 is press-fitted into the insertion hole 58b. Thereby, the contact thermal resistance between the insertion hole 58b and the heat pipe 48 is reduced.
That is, the contact area of the outer peripheral surface of the heat pipe 48 with respect to the inner peripheral surface of the cylindrical insertion hole 58b is increased, and heat transfer from the heat pipe 48 to the radiating fins 58 is improved.
As a result of the formation of a cylindrical space 60 extending in the depth direction between the radiating fins 58, the movement of the cooling air is promoted by the chimney effect, as shown in FIG. The heat dissipation performance is further improved as compared with the configuration in which is opened.

  As shown in FIG. 5A, heat radiating fins 62 as second heat radiating plates are provided at the lowermost part of the heat radiator 50. The radiating fin 62 has a bent piece 62 a formed in the opposite direction to the radiating fin 58. The heat dissipating fins 62 are indicated by hatching in order to distinguish them from others.

The bent piece 62 a of the radiating fin 62 is formed so as to enter the inside of the bent piece 58 a of the radiating fin 58. In other words, the bent pieces 62a of the radiating fins 62 are formed so as to be in contact with each other so that the end faces of the bent pieces do not come into contact with the radiating fins 58, in other words. The radiating fins 58 and the radiating fins 62 are not fixed to each other.
If the heat radiator 50 is configured in this manner, the occupied space can be reduced by the dimension h as compared with the conventional configuration in which only one type of heat radiating fins 58 is stacked as shown in FIG.

This means that the radiator 50 can be made compact and the cooling duct 54 can be made small. This is because the dimension h affects the cross-sectional area of the connection portion of the cooling duct 54 to the radiator 50.
In the configuration shown in FIG. 5B, the space defined by the lowermost heat radiation fin 58 is open, so that the above-described chimney effect due to the cylindrical space 60 cannot be obtained by the lowermost heat radiation fin 58. Therefore, the cooling function is lowered accordingly.

Further, in the configuration shown in FIG. 5B, the bent piece 58a, which is a sharp sheet metal edge of the lowermost radiation fin 58, remains exposed, and the operator can easily touch the edge.
On the other hand, in this embodiment, when the radiating fins 62 are fitted in the opposite direction, the bent piece 62a of the lowermost radiating fin 62 is not exposed to the outside, and the bent pieces 58a of the adjacent radiating fins 58 are also bent pieces. By overlapping with 62a, the sharpness of the edge is lowered to the extent that there is almost no problem for the operator.

  The heat radiation fin 62 as the second heat radiation plate is slightly different from the heat radiation fin 58 as the first heat radiation plate in the developed shape (blank type), but the easiness of bending is the same as the heat radiation fin 58. Further, there is no need to perform post-processing such as extra bending processing for hiding the edge inside or surface pressing for reducing the sharpness of the edge as in the conventional case.

In the present embodiment, the bent pieces 62a of the radiating fins 62 are configured to enter the inside of the radiating fins 58. However, as shown in FIG. In this case, the blank type of the heat radiating fin 62 can be made the same as that of the heat radiating fin 58, and there is an advantage that the manufacturing cost can be reduced.
In addition, as shown in FIG. 7, the bending direction of the bent pieces 62 a of the radiating fins 62 may be the same as that of the radiating fins 58, and may be configured to fit inside or outside the radiating fins 58.

FIG. 8B shows a second embodiment.
The same parts as those in the above-described embodiment are denoted by the same reference numerals, and the description on the configuration and the function already described is omitted as appropriate unless otherwise necessary (the same applies to other embodiments).
In this embodiment, the unfolded shape of the radiating fin 62 is the same as that of the radiating fin 58, and the bent position of the bent piece 62a is shifted to the inside of the radiating fin 62 by the plate thickness (dimension h1).
Compared to the radiator 50 shown in the first embodiment, a slight space expansion corresponding to the plate thickness occurs in the vertical direction, but since the blank type can be shared between the radiation fins 58 and the radiation fins 62, the manufacturing cost can be reduced. Can contribute to reduction.

FIG. 9 shows a third embodiment.
In the present embodiment, the radiating fins 58 and the radiating fins 62 have the same shape, and the respective insertion holes 58b and 62b are shifted by one plate thickness on either side of both ends.
The insertion hole 58b of the radiating fin 58 is located at the position Y from the right end and X from the left end in the figure, and the insertion hole 62b of the radiating fin 62 is located at the position X from the right end and Y from the left end in the figure.

That is, the radiating fins 62 are the same as when the radiating fins 58 are turned upside down. In other words, if a plurality of heat dissipating fins 58 are formed by shifting the position of the insertion hole 58b in a certain direction, and the one located at the bottom is turned upside down, the bottom one is used as the second heat dissipating plate. Fin 62 is formed.
Since the heat radiator 50 can be configured using the same heat radiation fins, the manufacturing cost can be reduced.

FIG. 10 shows a fourth embodiment.
In each of the above embodiments, the radiating fins 58 and 62 are configured to be bent in the same direction. However, in this embodiment, the bent pieces 64a of the radiating fins 64 as the first radiating plates are opposite to each other. It has become.
The heat radiating fins 66 and 68 as the second heat radiating plates positioned at the uppermost and lowermost positions have a shape that forms a cylindrical space between the adjacent heat radiating fins 64.

As shown in FIG. 10A, the radiating fins 66 and 68 have bent pieces 66a and 68a on only one side, and the respective bending directions are opposite to each other.
As shown in FIG. 10B, only the heat radiation fins 66 may be formed, and at the bottom, the heat radiation fins 68 may be formed by turning them over. In this case, the second heat radiating plate can be of one type, and the manufacturing cost can be reduced.
Also in the present embodiment, it is not necessary to perform post-processing such as extra bending processing for hiding the edge inside or surface pressing for reducing the sharpness of the edge as in the prior art.

  In each of the above embodiments, a plurality of heat pipes 48 are provided. Moreover, if a heat conductive member is a member with high heat conductivity, it will not be limited to a heat pipe.

The preferred embodiments of the present invention have been described above. However, the present invention is not limited to such specific embodiments, and unless specifically limited by the above description, the present invention described in the claims is not limited. Various modifications and changes are possible within the scope of the gist.
The effects described in the embodiments of the present invention are merely examples of the most preferable effects resulting from the present invention, and the effects of the present invention are limited to those described in the embodiments of the present invention. is not.

38 Fixing Device as Heat Generation Source 44 Heat Dissipation Unit 46 Shielding Panel 48 Heat Pipe as Heat Conducting Member 50 Heat Dissipator 52 Heat Absorbing Panel as Heat Absorbing Member 58, 64 Heat Dissipating Fins 58a, 62a, 64a as First Heat Dissipating Plate, 66a, 68a Bending piece 58b, 62b, 64b, 66b, 68b Insertion hole 60 Space 62, 66, 68 Radiation fin as second heat radiation plate

JP 2002-246521 A

Claims (9)

One or more rod-like heat conducting members;
A plurality of first heat radiating plates that are laminated by being inserted through the heat conducting member in a state of crossing in the longitudinal direction of the heat conducting member, and having bent pieces extending in the laminating direction at both ends;
A second heat dissipating plate inserted through the heat conducting member and laminated together with the first heat dissipating plate in the same manner as the first heat dissipating plate;
With
The first heat radiating plate is laminated in a state in which a space is held between the bent pieces so that a cylindrical space exists between the first heat radiating plates,
The second heat radiating plate is laminated with the first heat radiating plate so that the end faces of the bent pieces do not come into contact with each other, and has a shape that forms the cylindrical space with the first heat radiating plate. Has a radiator. The heat radiator according to claim 1,
A radiator in which the heat conducting member is a heat pipe. In the heat radiator according to claim 1 or 2,
The first heat radiating plate is a radiator in which the bent pieces are formed in the same direction, and the second heat radiating plate is formed in the direction opposite to the first heat radiating plate. The heat radiator according to claim 3,
A radiator in which the first radiator plate and the second radiator plate have the same developed shape. The heat radiator according to claim 4,
The insertion hole for passing through the heat conducting member is a radiator that is shifted by a plate thickness on either side of the both end portions of the first heat radiating plate and the second heat radiating plate. In the heat radiator as described in any one of Claims 1-5,
The heat radiator by which the penetration hole for penetrating the said heat conductive member formed in the 1st heat sink and the 2nd heat sink is formed by the burring process. A radiator according to any one of claims 1 to 6,
A shielding panel arranged to partition between the heat generation source and other members;
With
A heat radiating unit in which a portion of the heat conducting member extending to the outside of the radiator is held by a surface of the shielding panel facing the heat generation source. In the heat dissipation unit according to claim 7,
A heat dissipation unit in which a surface of the shielding panel facing the heat generation source and the heat conducting member are covered with a heat absorbing member.   An image forming apparatus comprising the heat dissipation unit according to claim 7.

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