JPH07168511A - Exhaust heat structure for housing - Google Patents

Abstract

PURPOSE:To provide an exhaust heat structure for a housing, which can reduce the size of the housing and whose components do not cost very much. CONSTITUTION:Air sucked from outside by means of a suction fan 24 is sent outside by means of an exhaust fan 25, so that the air flows through in contact with the internal wall 20 of a heat exchange chamber 21. Thus, the heat transmitted to the internal wall 20 from a heat source 5 is cooled by heat exchange between airs via the internal wall 20. Because the heat from the heat source 5 is cooled by means of the heat-exchange chamber 21, it is not transmitted to a cover 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust heat structure for a housing having a heat source inside.

[0002]

2. Description of the Related Art Conventionally, in a case of an electronic device or the like having a heat source inside, the heat generated by the heat source is discharged to the outside by discharging the air inside the case to the outside by a heat exhaust fan. .

FIG. 6 is a sectional view of a conventional electrophotographic printer as seen from the side, and FIG. 7 is a sectional view taken along line XX of FIG. The paper P inserted from the paper feed port 1 is transferred by the transfer unit 4A immediately below the photoconductor drum 4 in the process of being transferred in the direction of the arrow A1 by the transfer means such as the tractor feeder 2 and the transfer roller 3. Next, fixer 5
After being fixed by, the sheet is discharged from the sheet discharge port 6. Case 7
Are entirely covered by the cover 8.

Usually, the fixing device 5 generates high heat as surplus heat. Therefore, in order to release this heat, a heat exhaust port 9 opened to the outside is opened in the cover 8 above the fixing device 5, and the heat is discharged. Four heat fans 10 are provided, and the air sucked from the paper discharge port 6 rises around the fixing device 5, reaches the upper end of the cover 8, and is discharged to the outside from the heat discharge port 9 by the heat discharge fan 10. It is designed to generate an air flow. Therefore,
The air warmed by the heat radiation of the fixing device 5 is discharged to the outside of the housing 7 as indicated by an arrow A2.

Further, since the transfer section 4A is easily affected by heat, a partition wall 8a for cutting off heat transferred from the fixing device 5 due to convection and radiation of air is provided inside the cover 8. Since the control unit 11 is provided with a power supply device, a control circuit, and the like, a slight amount of heat is generated here as well. For this reason, a free flow fan 13 is provided that sucks the air inside the housing 7 in the direction of the arrow A3 and exhausts the air to the outside of the housing 7 through the directional heat exhaust port 12.

As described above, the exhaust heat fan 10 and the free-flow fan 13 discharge the air inside the housing 7 to the outside. In addition to 6, the paper feed port 1 and the paper discharge port 6 are formed from the openings formed in the housing 7.

By the way, since the fixing device 5 heats and fixes the toner, it is necessary to maintain a predetermined temperature inside thereof. Therefore, if the fixing device 5 is cooled too much, the fixing performance will be unfavorably affected.
Also, the air volume by the free flow fan 13 needs to be suppressed so that the internal temperature of the fixing device 5 is maintained at an appropriate value.

For this reason, the heat transmitted from the fixing device 5 to the cover 8b in the vicinity thereof cannot be completely eliminated, so that the cover 8b is heated. For this reason, when a hand or a body comes into contact with the cover 8b, there is a possibility that the user feels a considerable amount of heat and causes discomfort. Therefore, it is necessary to separate the cover 8b and the fixing device 5 from each other and to use a resin material having a low thermal conductivity for the cover 8b or to attach a heat insulating material to the inside of the cover 8b.

[0009]

As a result, the former measure has a drawback that the housing cannot be downsized, and the latter measure has a drawback that the parts cost is high. The present invention has been made based on such a situation, and an object thereof is to make a housing compact, and
An object of the present invention is to provide an exhaust heat structure for a housing that does not require component costs.

[0010]

The heat exhausting structure for a housing of the present invention forms a heat exchange chamber by providing an inner wall between a heat source and a cover that covers the outside of the housing having a heat source inside. An intake port and an exhaust port opened to the outside of the housing are opened in the heat exchange chamber, and an intake fan that sucks air into the heat exchange chamber from the outside of the housing is provided at each of the intake port and the exhaust port. A discharge fan for discharging the air in the exchange chamber to the outside of the housing is provided. Further, the heat exhausting structure of the casing of the present invention is characterized in that a flow passage is formed inside the heat exchange chamber so that air flows uniformly in the heat exchange chamber.

[0011]

The air sucked from the outside by the suction fan is discharged to the outside by the discharge fan, so that the air comes into contact with the inner wall of the heat exchange chamber and flows. Thus, the heat transmitted from the heat source to the inner wall is cooled by exchanging heat with the air via the inner wall. The efficiency of heat exchange can be further improved by forming a flow passage on the inner surface of the heat exchange chamber so that air can uniformly flow in the heat exchange chamber.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing an embodiment in which the heat exhausting structure of the housing of the present invention is applied to the housing of an electrophotographic printer, and FIG. 2 is a Y1-Y1 sectional view of FIG. , FIG.
FIG. 4 is a sectional view taken along line Y2-Y2 of FIG. 1, and FIG.
FIG. 5 is a sectional view, and FIG. 5 is a perspective view showing an inner wall. 1 to 4, members that are the same as or correspond to those of FIGS. 1 and 2 showing a conventional example are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIGS. 1, 3 and 4, a cover 8
An inner wall 20 having a substantially J-shaped cross section as shown in FIG. 5 is provided between the heat source and the fixing device 5 (not shown in FIG. 1). By the above, a heat exchange chamber 21 having a space that covers the vicinity of the fixing device 5 and the upper part thereof is formed. A first suction port (suction port) 22 is provided at one end of the heat exchange chamber 21 in the longitudinal direction (the horizontal direction of the cover 8), and a first discharge port (discharge port) 23 is provided at the other end of the cover 8. ing. The inner wall 20 has a first
Mounting portions 26 and 27 for mounting a fan are formed near the suction port 22 and the first discharge port 23, and a first suction fan (suction fan) 24 and a first discharge fan (discharge fan) are formed in each mounting portion, respectively. 25 is attached.

As shown in FIGS. 1 and 3, the cover 7 above the first suction port 22 and the first discharge port 23 is provided with a housing 7
Has a second inlet 28 and a second outlet 29 for opening the inside of the container to the outside. A second suction fan 30 and a second discharge fan 31 are attached to the second suction port 28 and the second discharge port 29, respectively.

Next, the operation will be described. When the first suction fan 24 rotates, air is sucked into the heat exchange chamber 21 from the outside of the cover 8, and when the first discharge fan 25 rotates, the air inside the heat exchange chamber 21 moves outside the cover 8. Is discharged to. That is, the air is forcibly distributed as shown by the arrow F1 in FIG.

The surplus heat from the fixing device 5 is transmitted to the inner surface 20a of the housing of the inner wall 20 by convection and radiation, and then,
The heat is conducted from the inner surface 20a of the housing to the inner surface 20b of the heat exchange chamber. When this heat exchange inner surface 20b comes into contact with the air sucked from the outside, heat is exchanged and the inner wall 20 is cooled. Therefore, the heat transferred from the fixing device 5 is cooled via the inner wall 20 and the heat exchange chamber 21. Therefore, the inner wall 20 is preferably made of a material having a high thermal conductivity, for example, a metal such as iron or aluminum in order to increase the heat exchange efficiency.

On the other hand, when the second suction fan 30 rotates, air is sucked in from the outside of the cover 8, and when the second discharge fan 31 rotates, the air inside the housing 7 is discharged to the outside. To be done. That is, in the vicinity of the fixing device 5, the air is forced to flow as shown by the arrow F2 in FIG. By circulating the air in the vicinity of the fixing device 5, the air warmed by the excess heat of the fixing device 5 is discharged to the outside.

By the way, the heat exchange chamber 21 formed by the inner surface of the cover 8 and the heat exchange chamber inner surface 20b of the inner wall 20.
Is a space sandwiched by substantially uniform curved surfaces, so that the air sucked from the first suction port 22 flows unilaterally to the first discharge port 23. However, as shown in FIG.
If the air flow is stagnant at the corner A, there is a concern that the efficiency of heat exchange will decrease. Therefore, the guide member 20c is connected to the heat exchange inner surface 20b of the inner wall 20.
It is preferable to form the flow passage L through which the air flows to the corner A by standing upright. In this case, the air sucked from the first suction port 23 is divided into the orthogonal direction F1a and the detour direction F1b by the guide member 20c, and the air divided in the detour direction F1b flows to the corner A. Since the air evenly contacts and flows over the entire surface of the heat exchange inner surface 20b of the inner wall 20, heat exchange can be performed more efficiently.

The number and shape of the guide members 20c may be changed according to the shape and size of the heat exchange chamber 21. Also,
Instead of providing the guide member 20c on the inner wall 20 side, it may be provided on the inner surface side of the cover 8 or on both sides. Further, the guide member 20c may be formed integrally with a part of the inner wall 20 or the cover 8 instead of being formed separately from the inner wall 20 or the cover 8. Further, the inner wall 20 is not limited to the shape shown in this embodiment, but may be any shape that allows air to flow through the heat exchange chamber 21, such as the cover shape of the housing and the arrangement state of the heat source and the cover. It can be appropriately modified according to the above.

Further, although the case of the electrophotographic printer has been described in the present embodiment, the scope of application of the present invention is not limited to this, and a case having a heat source, for example,
It goes without saying that it can be widely applied to electronic devices in general.

In this embodiment, in order to circulate the air in the heat exchange chamber 21, the first suction fan 24 and the first discharge fan 25, and the first suction port 22 and the first discharge port 2 are provided.
3 is provided for each one, but the present invention is not limited to this. The intake fan and the exhaust fan, and the intake port and the exhaust port can be appropriately modified in number, arrangement, and the like according to the heat source.

Further, in the present embodiment, the second suction fan 30 and the second discharge fan 31 for discharging the air whose temperature has been raised by the surplus heat from the fixing device (heat source) 5 are provided. In the above, the fans 30 and 31 can be omitted depending on the heat source, and the number and arrangement thereof can be appropriately modified.

According to the above-described embodiment, the air sucked from the outside by the first suction fan (suction fan) 24 is discharged to the outside by the first discharge fan (discharge fan) 25, so that the heat exchange of the air occurs. It contacts the inner wall 20 of the chamber 21 and circulates. As a result, the heat transferred from the fixing device (heat source) 5 to the inner wall 20 is cooled by exchanging heat with the air via the inner wall 20. Further, if the guide member 20c that forms the flow passage L that allows the air to uniformly flow in the heat exchange chamber 21 is formed on the heat exchange chamber inner surface 20b,
The efficiency of heat exchange is further improved.

Therefore, since the surplus heat of the fixing device 5 can be effectively cooled, unlike the conventional case, the cover 8b and the fixing device 5 are
It is not necessary to separate the space between the cover 8b and the cover 8b, and it is not necessary to use a resin material having a low thermal conductivity for the cover 8b or to attach a heat insulating material inside the cover 8b. Further, it is not necessary to take a measure to provide a partition wall between the fixing device 5 and the transfer portion 4A. As a result, there is an advantage that the housing 7 can be downsized and the cost of parts can be reduced.

[0025]

As described above, according to the exhaust heat structure of the housing of the present invention, the air sucked from the outside by the suction fan is discharged to the outside by the discharge fan, whereby the air is exchanged with the heat exchange chamber. It comes into contact with the inner wall of the and distributes. Thus, the heat transmitted from the heat source to the inner wall is cooled by exchanging heat with the air via the inner wall. Also,
The efficiency of heat exchange can be further improved by forming a flow passage on the inner surface of the heat exchange chamber so that air can uniformly flow in the heat exchange chamber.
Therefore, since the heat of the heat source can be effectively cooled, unlike the conventional method, the cover and the heat source are separated from each other, the cover is made of a resin material having a low thermal conductivity, and a heat insulating material is attached to the inside of the cover. You don't have to. As a result, there is an advantage that the housing can be downsized and the cost of parts can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a case in which a heat exhausting structure of a casing of the present invention is applied to a casing of an electrophotographic printer.

2 is a cross-sectional view taken along line Y1-Y1 of FIG.

3 is a cross-sectional view taken along line Y2-Y2 of FIG.

FIG. 4 is a sectional view taken along line ZZ in FIGS. 3 and 4.

FIG. 5 is a perspective view showing an inner wall.

FIG. 6 is a side sectional view showing a conventional heat exhaust structure of a housing.

7 is a sectional view taken along line XX of FIG.

[Explanation of symbols]

 5 Fixing Device (Heat Source) 7 Housing 8 Cover 20 Inner Wall 20c Guide Member 21 Heat Exchange Chamber 22 First Intake Port (Intake Port) 23 First Exhaust Port (Exhaust Port) 24 First Intake Fan (Intake Fan) 25 First Exhaust fan (exhaust fan) L Flow passage

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display area H05K 7/20 HG

Claims (2)

[Claims] 1. A heat dissipation structure of a housing having a heat source inside, wherein a heat exchange chamber is formed by providing an inner wall between the heat source and a cover covering the outside of the housing, A suction fan that opens a suction port and a discharge port open to the outside of the heat exchange chamber, and sucks air into the heat exchange chamber from outside the housing at each of the suction port and the discharge port. And a discharge fan for discharging the air in the heat exchange chamber to the outside of the case, respectively. 2. The exhaust heat structure for a casing according to claim 1, wherein a flow passage is formed inside the heat exchange chamber so that air can uniformly flow in the heat exchange chamber.