JPH04184381A - Cooling device - Google Patents

Abstract

PURPOSE:To obtain high ventilating efficiency without making a device larger by providing a long duct opposed to a member to be cooled which radiates heat so that it may include at least the upper part of the member and an exhaust means which is disposed on one end side of the duct and exhausts air in the duct to the outside of a machine and setting the cross-sectional area of the duct smaller as it goes away from a fan. CONSTITUTION:The air which absorbs heat radiated from a heating roller 1 is sucked to the inside of the duct 2 in a direction shown by an arrow A. Since the cross-sectional shape of the duct 2 is set to become smaller as it goes away from the fan 3, the air is introduced inside to a part opposite to a fan 3 side in a longitudinal direction in the duct 2 by sufficient suction force and exhausted from an exhaust window 4a in a direction shown by an arrow B by the fan 3, so that the air which absorbs the radiated heat is not retained, and the ventilating efficiency is improved. When the air is exhausted to the outside of a machine body, the circumference of the roller 1 becomes in a negative pressure state, and the cool air of the circumference is gathered to the circumference of the roller 1, then the heat radiated by the roller 1 is absorbed. This action is repeated with the high ventilating efficiency, and the air which absorbs the radiated heat is exhausted to the outside to cool the heating roller.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a cooling mechanism, and more particularly, to a cooling mechanism optimal for image forming apparatuses such as copying machines, facsimile machines, and page printers.

<Prior Art> Generally, this type of cooling device is employed in a copying machine 40 shown in FIG. 4, for example.

Inside the body 41 of the copying machine 40 shown in FIG. 4, there is a paper feed mechanism 43 that conveys paper P stored in a paper feed cassette 42 to the downstream side, and a developing unit disposed downstream of the paper feed mechanism 43. 44, and a heat fixing device 45 disposed downstream of the developing unit 44.

The heat fixing device 45 includes a heating roller 46, and the heating roller 46 (an example of a member to be cooled) and a guide roller 46g paired therewith nip and hold the paper P on which the toner image has been transferred by the developing unit 44. The configuration is such that the toner image is fixed on the paper P by conveying it.

Due to the above-described fixing process, the temperature of the heating roller 46 is considerably high while the copying machine 40 is powered on.

Therefore, conventionally, as shown in FIG.
A long duct 47 is placed oppositely above the duct 47.
The heating roller 46 is heated by a fan 48 arranged on one end side.
The air that has absorbed the emitted heat is discharged to the outside of the copying machine 40.

<Problems to be Solved by the Invention> However, since the duct 47 explained in FIGS. 4 and 5 has the same cross-sectional area,
The farther away from the fan 48, the weaker the suction force of the duct 47, and the worse the ventilation efficiency becomes.

As a result, the farther away from the fan 48 the air that has absorbed the emitted heat accumulates, and the heating roller 46 is not sufficiently cooled, leading to the risk of thermal effects on the components built into the fuselage 41, especially the photoreceptor. .

In order to solve such a problem, a structure in which fans are placed on both sides of the duct 47 can be considered, but this not only increases the size of the entire device, but also increases power consumption because two fans must be rotated. , undesirable.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an inexpensive cooling device with good ventilation efficiency without requiring an increase in the size of the device.

Means for Solving the Problems> In order to solve the above problems, the cooling device of the present invention includes a long duct that faces a member to be cooled that emits heat, including at least the upper part, and one end side of the duct. The duct is characterized in that the cross-sectional area of the duct is set to become smaller as the distance from the fan increases.

In the present invention, the cross-sectional area of the duct is set to become smaller as it moves away from the fan, so the duct of the present invention sucks air with a predetermined suction force regardless of its distance from the fan. do. Therefore, the air that has absorbed the heat emitted from the cooled member is discharged to the outside with sufficient suction force up to the side opposite to the fan in the longitudinal direction within the duct. As a result, the air that has absorbed the emitted heat no longer stagnates, and the member to be cooled is cooled with high ventilation efficiency.

<Example> Hereinafter, an example of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view of the main parts of an image forming apparatus employing an embodiment of the present invention, in which a heating roller 1 (cooled member) is shown.
A long duct 2 whose cross section opens in a downward U-shape is opposed above the guide roller 1a that is paired with the guide roller 1a. An exhaust fan 3 is arranged at one end of the duct 2 so as to face the duct 2 in the longitudinal direction. Note that the fan 3 only needs to be disposed on one end side of the duct 2; for example, the fan 3 may be disposed in a position where its axis is perpendicular to the longitudinal direction of the duct 2.

A cover 4 is arranged around the fan 3. The cover 4 is equipped with an exhaust window 4a on the front, and this exhaust window 4
It is configured such that air from the duct 2 can be discharged to the outside from a. Note that on the upstream side of the heating roller 1 in the paper feeding direction, a photosensitive drum 6 built in the developing unit 5 is arranged parallel to the duct 2, and the drum 6 of the duct 2
The wall 2a facing the photoreceptor drum 6 has a length such that the heat of the heating roller 1 is not released to the photoreceptor drum 6.

As shown in FIG. 2, the duct 2 of the present invention is configured such that the left side of the duct 2 in plan view inclines toward the right as the distance from the fan 3 increases, so that the cross section becomes gradually narrower. As a result, the air that has absorbed the heat emitted by the heating roller 1 is
As will be described later, the air is discharged to the outside with sufficient suction force up to the side of the fan 3 in the direction of the longitudinal force inside the duct 2, so that the ventilation efficiency is increased. Note that the planar shape of the duct 2 may be such that the left and right sides thereof are inclined toward the center of the duct 2 as the distance from the fan 3 increases, as shown in FIG. 3, for example. Further, the cross section of the duct 2 does not necessarily have to be U-shaped, opening downward.

According to the above structure, as shown in FIG. 1, air that has absorbed heat emitted from the heating roller 1 is sucked into the duct 2 as shown by arrow A. Here, the cross-sectional shape of the duct 2 is set to become smaller as it moves away from the fan 3, so that the air has sufficient suction power to reach the part of the duct 2 on the side opposite to the fan 3 in the longitudinal direction. The air is introduced into the duct 2 and further discharged by the fan 3 from the exhaust window 4a of the cover 4 in the direction shown by arrow B. As a result, air that has absorbed emitted heat no longer stagnates, improving ventilation efficiency.

When the above air is discharged to the outside of the aircraft by fan 3,
Since the area around the heating roller 1 becomes negative pressure, the surrounding cold air is collected around the heating roller 1 and absorbs the heat emitted by the heating roller 1. By repeating the above operation with high ventilation efficiency, the air that has absorbed the emitted heat is exhausted to the outside, and the heating roller 1 is cooled.

Note that the cooling member of the present invention is not limited to the heating roller 1, but should be understood to include other members built into the image forming apparatus together with the heating roller 1, such as a cover that covers the periphery of the heating roller 1. It is.

Further, the cooling device to which the present invention is applied can be employed in various image forming devices such as facsimile machines and page printers in addition to copying machines.

Furthermore, the present invention is not limited to image forming apparatuses, but can also be applied to apparatuses having a heating element as a member to be cooled, or a member that becomes high temperature by receiving heat from the heating element, and is otherwise within the scope of the claims. It goes without saying that various design changes can be made.

<Effects of the Invention> As explained above, according to the present invention, the cross-sectional area of the duct is set to become smaller as the distance from the fan increases. Inhale air with suction power. Therefore, the air that has absorbed the heat emitted from the cooled member is discharged to the outside with sufficient suction force up to the side opposite to the fan in the longitudinal direction within the duct. As a result, the air that has absorbed the released heat no longer stagnates,
Components to be cooled are cooled with high ventilation efficiency.

Moreover, since the present invention can be easily adopted by simply changing the shape of the duct, it can be implemented with the same number of parts as the conventional structure, and the entire device does not become larger, reducing manufacturing costs. It can be carried out in

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the main parts of the present invention, Fig. 2 is a plan view of the duct of the invention, Fig. 3 is a plan view showing another shape of the duct of the invention, and Fig. 4 is a general view. A schematic side sectional view showing the structure of the copying machine. FIG. 5 is a perspective view of the cooling device employed in FIG. 4. 1... Heating roller (cooled member), 2... Duct,
3...Fan.

Claims (1)

[Scope of Claims] 1. A long duct facing a cooled member that emits heat, including at least the upper part, and disposed at one end of the duct to discharge air in the duct to the outside of the machine. and an exhaust means, wherein the cross-sectional area of the duct is set to become smaller as the distance from the fan increases. 2. The cooling device according to claim 1, wherein the member to be cooled is a heating roller built into an image forming apparatus including an image forming mechanism and an image fixing mechanism.