JPH10161511A - Mechanism for preventing reverse air-blowing of cooling fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent malfunction caused by reversely attaching a cooling fan in a device. SOLUTION: This mechanism is provided with a rotation preventing means preventing the rotation of the cooling fan 1 only in the case the fan 1 is reversely attached to the device. The rotation preventing means is a string-like member 31 hung down between the exhaust port 22 of the device and the fan 1. Then, the rotation preventing means is a means provided between the exhaust port 22 of the device and the fan 1 and set as a pressing member pressing the center part of the fan 1. Furthermore, the rotation preventing means is a means provided between the exhaust port 22 of the device and the fan 1 and set as a projecting member projecting toward a position corresponding to the blade of the fan 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backflow prevention mechanism for a cooling fan attached to a device that generates heat in a copying machine or the like.

[0002]

2. Description of the Related Art A device for generating heat in a copying machine or the like has a cooling fan near a heat source. The cooling fan discharges the air heated by the heat source out of the device.
This prevents the temperature inside the device from rising and protects heat-sensitive components.

FIG. 5A is a front view showing an exhaust side of a cooling fan, and FIG. 5B is a rear view showing an intake side of the cooling fan. The cooling fan 1 rotates and sends an impeller 11 for pumping air, a motor (not shown) for driving the impeller 11, and a housing 1 for housing the impeller 11.
2 Then, the cooling fan 1 is attached by screwing a mounting hole 12 c provided through the housing 12. However, the shape of the housing 12 is as follows.
As shown in the figure, the exhaust side and the intake side are almost symmetric. For this reason, the cooling fan 1 can be attached in either direction. Therefore, the mounting direction of the cooling fan 1 may be erroneously set at the time of manufacturing and assembling or maintaining the apparatus.

A cooling fan mounted in the opposite direction pumps air in the opposite direction when the device is turned on. For this reason,
Air heated by the heat source is not exhausted out of the device,
Sprays on components located around the heat source. Then, problems such as damage and deformation of heat-sensitive parts are caused.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to prevent problems caused by mounting a cooling fan on a device in a reverse direction as described above.

[0006]

In order to solve the above problems, the present invention has the following structure. That is, the rotation preventing means for preventing the rotation of the cooling fan only when the cooling fan is attached to the device in the opposite direction is provided. Further, the rotation preventing means is a string-shaped member vertically provided between an exhaust port of the apparatus and the cooling fan.
The rotation preventing means is provided between the exhaust port of the apparatus and the cooling fan, and is a pressing member for pressing a central portion of the cooling fan. Further, the rotation preventing means is provided between an exhaust port of the apparatus and the cooling fan, and is a projecting member projecting toward a position corresponding to a blade of the cooling fan.

[0007]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a first embodiment of the present invention, and FIG. 2 is a diagram showing a configuration of a cooling fan.

Prior to the description of an embodiment of the present invention, an outline of a configuration of a cooling fan will be described. As described above, the cooling fan 1 includes the impeller 11, the motor (not shown) for driving the impeller 11, and the housing 12 that houses the impeller 11. The impeller 11 includes a rotating shaft 13 and a plurality of blades 14 disposed around the rotating shaft 13. A motor for driving the impeller 11 is built in the rotating shaft 13. On the other hand, the housing 12 has a substantially square exhaust surface 12a and intake surface 12b, and mounting holes 12c are formed at four corners thereof. Further, a fixed shaft 15 is provided at the center of the exhaust surface 12a of the housing 12, and the fixed shaft 15 is supported by a plurality of support members 16 connecting the housing 12 and the fixed shaft 15. The rotating shaft 13 is rotatably connected to the fixed shaft 15. The cooling fan 1 causes air to flow from the rotation shaft 13 to the fixed shaft 15 by rotation of the impeller 11, that is, from right to left in FIG. 2B.

The parts of the device to which the cooling fan 1 is attached are as follows. As shown in FIG. 1A, an exhaust port 22 is provided on the side surface 21 of the apparatus. The exhaust port 22 includes a plurality of small holes, slits, and the like to prevent foreign matter from entering. An air passage 23 is provided inside the exhaust port 22, and the air passage 23 is provided with a mounting surface 24 for mounting the cooling fan 1. The cooling fan 1 has its exhaust surface 12a abutting against the mounting surface 24 and is mounted by screws (not shown).

A string-shaped member 31 formed of a string, a ribbon, or the like is provided vertically from the upper portion of the air passage 23 between the exhaust port 22 and the cooling fan 1. The material of the string-like member 31 is desirably light and strong, and its length is set to a length suitable for obtaining the operation described later. Moreover, the string-shaped member 31 may be plural.

The operation of the cord-like member 31 will be described below.
FIG. 1A shows a state in which the cooling fan 1 is mounted in a correct direction and rotated. At this time, the air flows from the inside of the apparatus to the outside of the apparatus, that is, flows in the direction of arrow Q1 in the figure. The string-like member 31 is stuck to the back surface of the exhaust port 22 by the flow of air, but the cooling fan 1 can rotate as it is.

FIG. 1B shows a state in which the cooling fan 1 is mounted in the opposite direction and rotated. At this time, the air flows from outside the device to the inside of the device, that is, flows in the direction of arrow Q2 in the figure. The string-like member 31 is used to cool the cooling fan 1 by the flow of air.
And entangled with the impeller 11 to stop its rotation.

Generally, when the cooling fan 1 is stopped during operation of the apparatus, a signal called a lock signal or a fail signal is output. Thus, the apparatus can detect the stop of the cooling fan 1. The device that detects the stop of the cooling fan 1 stops its operation to avoid a problem. After that, the apparatus notifies the cooling fan 1 of the stoppage by an error message or the like, so that the cooling fan 1 may be checked.

Next, a second embodiment of the present invention will be described. The second embodiment focuses on the form of the cooling fan 1. Specifically, as shown in FIG. 2B, the exhaust surface 12a and the end surface 15a of the fixed shaft 15 are substantially in the same plane, and the intake surface 12b and the end surface 13a of the rotating shaft 13 are in substantially the same plane. It pays attention to.

FIG. 3 is a view showing a second embodiment of the present invention. In the figure, a pressing member 32 made of an elastic material such as urethane rubber is provided on the back surface of the exhaust port 22. The shape of the pressing member 32 is set so as to press the central portion of the cooling fan 1, that is, the end surface 15 a of the fixed shaft 15 when the cooling fan 1 is attached.

The operation of the pressing member 32 will be described below. FIG. 3A shows a state in which the cooling fan 1 is mounted in a correct direction. At this time, the pressing member 32 is connected to the end face 1 of the fixed shaft 15.
Press 5a. However, since the rotation of the cooling fan 1 is not prevented, the cooling fan 1 rotates when the apparatus is operated.

FIG. 3B shows a state in which the cooling fan 1 is mounted in the opposite direction. At this time, the pressing member 32 is
The third end 13a is pressed. For this reason, since the rotation of the cooling fan 1 is prevented, the cooling fan 1 does not rotate even when the apparatus is operated. Also in this case, since the cooling fan 1 is stopped when the apparatus is operating, the apparatus stops operating for the purpose of avoiding trouble as in the first embodiment.

It should be noted that the pressing member 32 only needs to press the central portion of the cooling fan 1 when the cooling fan 1 is mounted, and therefore the material and the configuration are not limited to the above-described embodiment. Therefore, a leaf spring or a coil spring may be used as the elastic material, or a combination thereof may be used.

Next, a third embodiment of the present invention will be described. The third embodiment also focuses on the form of the cooling fan 1. Specifically, as shown in FIG. 2B, the distance L1 from the exhaust surface 12a to the blade 14 is changed to the intake surface 12b.
From the distance L2 to the blade 14.

FIG. 4 is a view showing a third embodiment of the present invention. In the drawing, a projecting member 33 having a length L is provided at the exhaust port 22 with its tip protruding toward the blade 14. Exhaust port 2
Assuming that the distance from the back surface of the second member 2 to the mounting surface 24 is L3, the length L of the protruding member 33 is L <L1 + L3 and L> L.
Set to be 2 + L3.

The operation of the projecting member 33 will be described below. FIG. 4A shows a state in which the cooling fan 1 is mounted in a correct direction. At this time, the protruding member 33 protrudes toward the blade 14 but does not abut. Therefore, since the rotation of the cooling fan 1 is not prevented, the cooling fan 1 rotates when the apparatus is operated.

FIG. 4B shows a state in which the cooling fan 1 is mounted in the opposite direction. At this time, the protruding member 33 is
Protrude toward and abut. For this reason, since the rotation of the cooling fan 1 is prevented, the cooling fan 1 does not rotate even when the apparatus is operated. Also in this case, since the cooling fan 1 is stopped when the apparatus is operating, the apparatus stops operating for the purpose of avoiding trouble as in the first embodiment.

The structure of the projecting member 33 is not limited to the above embodiment, since the projecting member 33 only needs to project toward the blade 14 of the cooling fan 1 when the cooling fan 1 is mounted. Therefore, a configuration in which the protruding member 33 is provided in the air passage 23 and the tip thereof is bent toward the blade 14 may be adopted.

[0024]

As described above, according to the present invention, the rotation preventing means for preventing the rotation of the cooling fan is provided only when the cooling fan is mounted on the apparatus in the reverse direction. Therefore, it is possible to prevent a problem that occurs when the cooling fan is attached to the device in the opposite direction, that is, damage or deformation of a heat-sensitive component.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a front view and a sectional view of a cooling fan.

FIG. 3 is a sectional view showing a second embodiment of the present invention.

FIG. 4 is a sectional view showing a third embodiment of the present invention.

FIG. 5 is a front view and a rear view of the cooling fan.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cooling fan 14 Blade 22 Exhaust port 31 String member 32 Pressing member 33 Projecting member

Claims (4)

[Claims] 1. A backflow prevention mechanism for a cooling fan, comprising: a rotation prevention means for preventing rotation of the cooling fan only when the cooling fan is mounted in an opposite direction to the apparatus. 2. The mechanism according to claim 1, wherein said rotation preventing means is a string-shaped member suspended from an exhaust port of the apparatus and said cooling fan. 3. The cooling device according to claim 1, wherein the rotation preventing means is provided between an exhaust port of the apparatus and the cooling fan, and is a pressing member for pressing a central portion of the cooling fan. Cooling fan backflow prevention mechanism. 4. The rotation preventing means is provided between an exhaust port of the apparatus and the cooling fan, and is a projecting member projecting toward a position corresponding to a blade of the cooling fan. A backflow preventing mechanism for a cooling fan according to claim 1.