JPH11194569A - Cooling device for image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device for an image forming device capable of improving cooling efficiency by increasing the capacity of a duct confluence section, and smoothing the flow of air. SOLUTION: A duct stay 20 is constituted of an integrally extrusion-molded aluminum material 8 and a resin material 9, and a plurality of holes 21 are provided on the aluminum material 8 at a horizontal portion X located above a fixing unit. An exhaust tube section 22 covering an axial fan 10 and opening holes provided on the horizontal portion X is extended from the exhaust end side to the suction end side, and the capacity of a duct confluence section is increased when the hot air passing through a hollow section A is discharged to the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for an image forming apparatus having a heat fixing device.

[0002]

2. Description of the Related Art FIG. 1 is a schematic sectional view of a general copying machine. In the drawing, reference numeral 1 denotes a photosensitive drum, 2 denotes a cleaning unit, 3 denotes a developing unit (these may be collectively referred to as an image forming unit), 4 denotes a fixing unit, and a reinforcing unit is provided on the upper and right sides of the fixing unit 4 in the drawing. And stays 5a, 5 also serving as heat shields
The stay 5b prevents radiation and heat conduction from the fixing unit 4 to the photosensitive drum 1, the cleaning unit 2, and the developing unit 3 on the right side. In the drawing, reference numeral 6 denotes a transfer / transport unit.

The direction in which the stays 5a and 5b are stretched is perpendicular to the plane of the drawing and is in the direction from the front to the back of the copying machine. However, since the stays 5a and 5b of this type are usually made of sheet metal, there is a problem that the heat capacity is small, and the stays 5a and 5b become hot immediately, and the heat heats the photosensitive drum 1 and the like.

That is, in image forming apparatuses such as copying machines in recent years, the size of the image forming apparatuses has been reduced, and the spacing between the units has been narrowed.
Temperature rise of various units located in the vicinity of is a problem. For example, in the case of the developing unit 3, toner scattering or the like due to a rise in temperature of the developer causes
In the case of (1), the recovery mechanism may be locked due to toner adhesion.

In order to deal with the problem caused by heat, ventilation ducts and the like have been provided in the machine. For example, the duct stay 7 shown in FIG. 2 is made of an aluminum material 8 as a strength member that is integrally formed by extrusion and a resin material 9. The aluminum material 8 is directed to the fixing unit side, and the horizontal portion X on the left side in the figure is fixed. It is located at the upper part of the unit, and the obliquely hanging portion Y on the right side in the figure is interposed between the photoreceptor drum and the fixing unit so that the outside air flows into the hollow portion A and the resin material 9 having a different thermal conductivity is interposed. Further, heat conduction to various units located on the side of the resin material 9 (the side other than the fixing unit side) and the accompanying temperature rise are prevented.

The duct stay 7 has a horizontal portion X.
An axial fan 10 for exhaust and an exhaust cylinder 11 are provided on the upper part of the resin material 9 which forms a curved portion, and a guide portion 12 is provided in a curved shape at the exhaust side end of the hanging portion Y so as to be cooled toward the exhaust fan 10. The air is collected and flowed. That is,
The duct stay 7 warmed by the hot air above the fixing unit is cooled by flowing outside air into the hollow portion A forming the duct to prevent a temperature rise.

However, if the shape and structure of the opening 13 provided on the upper surface of the resin material 9 for flowing the air flowing through the hollow portion A to the exhaust tube portion 11 are not taken into account, the duct stay 7 The air flow in the part does not go smoothly,
Difficulty may occur in exhaust efficiency.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cooling device for an image forming apparatus which can improve the cooling efficiency by making the volume of a duct junction smoother and larger in the flow of air. Another object of the present invention is to provide a cooling device for an image forming apparatus that can improve the cooling effect by intensively cooling a high-temperature portion. Still another object of the present invention is to provide a cooling device for an image forming apparatus that can further improve the cooling effect by allowing air to flow through the entire high-temperature portion on average.

[0009]

According to a first aspect of the present invention, there is provided a cooling apparatus for an image forming apparatus, which is arranged so as to be located from an upper portion of a fixing unit to an image forming unit side. A cooling duct that also serves as a stay made of a sheet metal material and a resin member, and the cooling duct is formed from a portion that covers an upper portion of the fixing unit and a portion that is located between the fixing unit and the image forming unit. Providing an axial fan and an exhaust cylinder covering the axial fan near the exhaust side end of a part covering the upper part of the fixing unit, and providing the axial fan provided at a part covering the upper part of the fixing unit. The opening is extended and extended toward the intake side end of the cooling duct to increase the volume of the confluence of the two portions.

According to a second aspect of the present invention, the cooling duct is provided with partition ribs interposed between the two portions so that the air volume can be adjusted.

According to a third aspect of the present invention, the cross-sectional shape of the exhaust cylinder is continuously changed.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. In the following, description will be made by assigning common reference numerals to parts common to the related art. FIG. 3 is a perspective view showing a first embodiment of the cooling device of the image forming apparatus according to the present invention. The duct stay 20 of the present embodiment is made of an aluminum material 8 and a resin material 9 as in the conventional example, but a plurality of holes 2 are formed in the aluminum material 8 in the horizontal portion X located on the fixing unit side.
1, an exhaust tube portion 22 that covers an opening hole provided in the axial fan 10 and the horizontal portion X extends from the exhaust end to the intake end, and discharges the hot air that has passed through the hollow portion A to the outside. By increasing the volume of the duct junction,
A smooth flow is formed to improve the exhaust efficiency, that is, the cooling efficiency. Although illustration of an opening hole provided in the horizontal portion X is omitted, it is provided in substantially the entire mounting base of the exhaust tube portion 22 to the horizontal portion X. The same applies to the following embodiments.

FIG. 4 is a perspective view showing a second embodiment of the cooling device of the image forming apparatus according to the present invention. The duct stay 30 of the present embodiment is the same as the duct stay 20 of the previous embodiment.
However, a partition rib 31 is provided at a boundary between a horizontal portion X located above the fixing unit and an oblique hanging portion Y interposed between the photosensitive drum and the fixing unit. Thus, the air flowing from the exhaust pipe portion 22 into the exhaust pipe portion 22 is throttled to increase the air flow from the horizontal portion X inside the duct where the temperature becomes higher than that from the hanging portion Y, thereby improving the cooling efficiency.

FIG. 5 is a perspective view showing a third embodiment of the cooling device of the image forming apparatus according to the present invention. The duct stay 40 of the present embodiment is also the same as the duct stay 2 of the first embodiment.
0, but by continuously changing the shape of the exhaust tube portion 41 from the exhaust end side to the intake end side as shown in the drawing, and then to continuously expand again at the intake end side. In addition, the suction of the axial fan 10 is prevented from being biased toward a portion in the vicinity thereof, and the air flow in the hollow portion A is averaged, thereby improving the cooling efficiency.

[0015]

As described above, in the cooling device for an image forming apparatus according to the first aspect, the axial fan and the exhaust cylinder are provided near the exhaust side end of the portion covering the upper portion of the fixing unit. The opening to the axial fan provided at the part covering the upper part of the fixing unit is extended and extended toward the intake side end of the cooling duct, and is located between the part covering the upper part of the fixing unit and the fixing unit and the image forming unit. Since the volume of the confluence at the part where the air flows is increased, the flow of air inside becomes smooth and the cooling efficiency is improved.

According to a second aspect of the present invention, there is provided a cooling device for an image forming apparatus, as described above, between a portion covering an upper portion of a fixing unit in a cooling duct and a portion located between the fixing unit and the image forming unit. Since the air volume can be adjusted by providing a partition rib interposed in the cooling duct, the air flows intensively into the high-temperature portion of the cooling duct, and the cooling efficiency is further improved.

According to the third aspect of the present invention, as described above, since the cross-sectional shape of the exhaust pipe portion is continuously changed, the cooling duct has a uniform temperature over the entire high-temperature portion. There is an effect that air flows smoothly and cooling efficiency is further improved.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a general copying machine using a heat fixing device.

FIG. 2 is a perspective view illustrating an example of a conventional cooling device of an image forming apparatus.

FIG. 3 is a perspective view showing a first embodiment of a cooling device of the image forming apparatus according to the present invention.

FIG. 4 is a perspective view showing a second embodiment of the cooling device of the image forming apparatus according to the present invention.

FIG. 5 is a perspective view showing a third embodiment of the cooling device of the image forming apparatus according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 photosensitive drum 2 cleaning unit 3 developing unit 4 fixing unit 5a, 5b stay 6 transfer / transport belt 7, 20, 30, 40 duct stay 8 aluminum material 9 resin material 10 axial fan 11, 22, 41 exhaust cylinder portion 12 Guide part 13 Opening hole 21 Hole 31 Partition rib X Horizontal part Y Hanging part

Claims (3)

[Claims] A cooling duct, which is made of a sheet metal material and a resin member and serves as a stay, is disposed from the upper portion of the fixing unit to the image forming unit side, and a portion covering the upper portion of the fixing unit with the cooling duct. An axial fan and an exhaust cylinder portion covering the axial fan formed on a portion near the exhaust side of a portion covering the upper portion of the fixing unit, formed from a portion located between the fixing unit and the image forming unit; The opening to the axial fan provided at a portion covering the upper part of the fixing unit is extended toward the intake side end of the cooling duct so as to increase the volume of the confluence of the two portions. A cooling device for an image forming apparatus, comprising: 2. The cooling device for an image forming apparatus according to claim 1, wherein a partition rib interposed between the two portions is provided in the cooling duct so that the air volume can be adjusted. 3. The cooling device for an image forming apparatus according to claim 1, wherein a cross-sectional shape of said exhaust tube portion is continuously changed.