JPH1162885A - Blower fan device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To easily and inexpensively detect a failure of a fan. SOLUTION: A plurality of, for example, a fan unit 1 having a fan whose rotation speed continuously varies according to the temperature, and a temperature detecting unit installed at a required position inside a PDP (Plasma Display Panel) panel, for example, to detect a temperature A temperature detecting unit 2 configured by a thermistor or the like, a rotational speed detecting unit 3 that detects a rotational speed of each fan based on a pulse output from each fan, and a fan control unit 4 that controls increase and decrease of the rotational speed of the fan unit 1. A storage unit 5 configured by a non-volatile memory for storing a fan failure detection value as a constant, a calculation unit 6 for calculating a ratio between a minimum value and a maximum value of the fan rotation speed, and a storage unit 5 storing the ratio. The determination unit 7 determines the magnitude of the detected failure value and the result calculated by the calculation unit 6, and the control unit 8 controls each unit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blower fan device having a plurality of fans.

[0002]

2. Description of the Related Art For example, a 42 inch PDP (Plasma Disp.
play panel), etc.
A blower fan device equipped with a fan such as a stand is provided, and forced air cooling is performed so that the temperature inside the panel does not become high.

FIG. 2 is a diagram for explaining the operation of the fan of the blower fan device, in which the number of rotations of the fan is switched (A) and the number of rotations of the fan is continuously varied (B).
FIG. 7C is a diagram (C) showing a maximum rotation speed and a minimum rotation speed of a plurality of fans.

As shown in FIG. 2A, a blower fan device used in a conventional PDP uses a temperature ta as a switching value based on a signal from a temperature sensor installed at a required portion in the PDP, and the fan operates at high speed. Operation is performed by switching between rotation and medium speed rotation. For example, at ta = 37 ° C. or higher, the fan rotates at high speed. Furthermore, if the fan breaks down and it becomes difficult to rotate,
The PDP side shuts off the power supply by detecting that the rotation speed at that time has decreased from the standard rotation speed to a preset value or less and outputting a failure signal. In addition, the PDP is prevented from being damaged due to temperature rise.

Actually, when the above PDP is used indoors as a flat-screen television or the like, the noise of the fan disturbs the sound of the television even at a medium speed rotation, which is annoying. Therefore, as shown in FIG. 2B, a blower fan device is provided in which a low-temperature switching value tb and a high-temperature switching value tc are provided and the number of rotations of the fan is continuously variable. This type of blower fan device, for example, by externally connecting a thermistor to the control terminal, varies the rotation speed according to the temperature detected by the thermistor, and outputs a pulse corresponding to the rotation speed from the rotation signal output terminal Is what you do. And FIG.
As shown in (b), the rotation speed of the fan is extremely low in a low-temperature region below tb, and the rotation speed gradually increases continuously in the region from tb to tc, and the fan rotates at a high speed above tc. Therefore, in a normal use condition at room temperature, the rotation speed of the fan is extremely low or low, and as a result, the operation sound of the fan is quiet.

[0006] In the blower fan device in which the rotation speed of the fan continuously varies, it is necessary to change the failure detection rotation speed for detecting the failure of the fan in accordance with the temperature. That is, as shown in FIG. 2B, a graph (indicated by a dashed line) indicating the rotation speed reduced by a required value according to the temperature is obtained from the graph indicating the standard rotation speed of the fan.

However, in order to obtain the failure detection rotational speed according to the temperature, for example, a means for numerical calculation is provided, or hardware such as a reference table for the temperature and the rotational speed is prepared. Software must be added, and there is a problem of cost increase.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to provide a blower fan device that can easily detect a failure of a fan at low cost.

[0009]

In order to achieve the above object, in a blower fan device provided with a plurality of fans,
Detects the maximum value of the fan rotation speed and the minimum value of the fan rotation speed for a plurality of fans, detects that the ratio of the minimum value to the maximum value is below a predetermined value, and outputs a signal indicating the detection result. I do.

A plurality of fans, a temperature detecting unit for detecting a temperature, a rotational speed detecting unit for detecting a rotational speed for each fan, a fan control unit for increasing / decreasing a rotational speed of the fan,
A storage unit that stores a fan failure detection value, a calculation unit that calculates a ratio between the minimum value and the maximum value of the fan rotation speed, and a failure detection value that is stored in the storage unit and a result calculated by the calculation unit. And a judgment unit for judging the magnitude of

The arithmetic unit calculates an average rotation speed based on the rotation speed of each fan, further calculates a ratio of the minimum value of the fan rotation speed to the average rotation speed, and stores the ratio of the fan rotation number in the storage unit. The two failure detection values are stored, and the determination unit determines the magnitude of the second failure detection value and the result calculated by the calculation unit.

Further, the rotation number detecting section is configured to sequentially calculate the average rotation number of the rotation number for a predetermined time for each fan.

[0013] Further, the fan is operated so that the number of revolutions is continuously variable according to the temperature.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS With the above configuration, a blower fan device according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an example of a blower fan device according to the present invention. Reference numeral 1 denotes a fan unit including a plurality of fans, for example, whose rotation speed continuously varies according to the temperature. 2 is, for example, a PDP (Plasma Display Pane)
l) A temperature detector that is installed at a required position inside the panel and consists of a thermistor that detects temperature. Reference numeral 3 denotes a rotation speed detection unit that detects the rotation speed of each fan based on the pulse output from each fan. Reference numeral 4 denotes a fan control unit that controls the number of revolutions of the fan unit 1 to increase or decrease. Reference numeral 5 denotes a storage unit that stores a fan failure detection value that is a constant and that is configured by a nonvolatile memory. Reference numeral 6 denotes a calculation unit for calculating a ratio between the minimum value and the maximum value of the fan speed. Reference numeral 7 denotes a determination unit that determines the magnitude of the failure detection value stored in the storage unit 5 and the result calculated by the calculation unit 6. Reference numeral 8 denotes a control unit that controls the above units.

The temperature detected by the temperature detector 2 is transmitted to the controller 8
Is transmitted to the fan control unit 4 via the control unit, and the fan control unit 4 controls the rotation speed of the fan unit 1 to increase or decrease.

The rotation speed detector 3 detects the rotation speed of each fan based on the pulse output from the fan, and for example, from the fan 1 to the fan n, the average rotation speed such as one second of the rotation speed for each fan. Ask for. The calculation unit 6 detects the minimum value and the maximum value of the fan rotation speed based on the average rotation speed and calculates a ratio therebetween. The determination unit 7 determines the magnitude of a failure detection value stored in the storage unit 5 based on, for example, an error in the number of rotations of the fan, and a result calculated by the calculation unit 6. As a result, when the ratio according to the determination result, for example, the ratio calculated by the arithmetic unit 6 is smaller than the failure detection value, the control unit 8 outputs a signal indicating that there is a failure, for example, “high” in voltage.

The operation of judging the result performed by the judging unit 7 is as follows.
This will be specifically described with reference to FIG. For example, if the allowable rotation error of the fan used by the blower fan device is ± 10%, the maximum rotation speed (max: A) of the plurality of fans within the allowable range is + 10%, The number of revolutions (mini: B) is minus 10%. Therefore,
The ratio (B / A) of the minimum rotation speed to the maximum rotation speed is “0.9
÷ 1.1 = 0.818 ... ”, and good products are within the variation range of 1 to 0.818 ... Therefore, the failure detection value is 0.82, and if less than this value, it is determined that a failure has occurred. For example, 1
Assuming that 70% of the standard rotation speed is reached due to the failure of one of the fans, the ratio of the minimum rotation speed to the maximum rotation speed at this time is "0.7 / 1.1 = 0.636 ... to 0.7 / 0.9 = 0.777 ..." Is less than about 0.78, and is less than the failure detection value (0.82), so that a failure can be determined. The ratio (B / A) between the minimum rotation speed and the maximum rotation speed is based on the allowable rotation error, and takes a constant value independent of the temperature. Value.

Further, instead of the maximum rotation speed (max: A),
The calculation unit 6 may calculate an average rotation speed based on the rotation speed of each fan, and calculate a ratio using the average rotation speed and the minimum rotation speed. For example, the ratio between the minimum number of rotations and the average number of rotations is “0.9 ÷ 1.0 = 0.9”.
In the range of 0.9 to 0.9. Therefore, the second failure detection value in this example is 0.9. If this is the case, the average speed can often be considered equal to the standard speed. In this case, the second failure detection value (0.9) of the fan is stored in the storage unit 5, and the determination unit 7 determines the magnitude of the second failure detection value and the value of the ratio calculated by the calculation unit 6.

[0019]

As described above, the present invention provides a blower fan device capable of easily detecting a failure of a fan at low cost. In summary, according to the present invention, the number of rotations corresponding to a decrease from the standard number of rotations for detecting the failure of the fan (failure detection rotation number)
Without directly calculating the ratio between the minimum rotation speed and the maximum rotation speed,
Since the failure can be determined based on the value of the ratio and the failure detection value as a constant, there is no need for a means for numerical calculation or a reference table for temperature and rotation speed. Therefore, there is no need to change to the conventional blower fan device, and it can be realized by adding a microcomputer program.

Further, the present invention is applicable to any one of a blower fan device having a fixed fan rotation speed, a variable rotation blower fan device, and a continuously variable operation blower fan device.
There is a merit that can be used in a wide range of fields.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an example of a blower fan device according to the present invention.

FIG. 2 is a diagram for explaining the operation of the fan of the blower fan device, in which the number of rotations of the fan is switched (A);
FIG. 6 is a diagram (b) illustrating an example in which the rotation speed of the fan is continuously variable (b) and the maximum rotation speed and the minimum rotation speed of a plurality of fans.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fan part 2 Temperature detection part 3 Revolution number detection part 4 Fan control part 5 Storage part 6 Calculation part 7 Judgment part 8 Control part

Claims (5)

[Claims] In a blower fan device having a plurality of fans, means for detecting a maximum value and a minimum value of a fan rotation speed for a plurality of fans, and calculating a ratio between the minimum value and the maximum value. Means, a means for storing a reference value, and means for comparing the ratio between the minimum value and the maximum value with the reference value, wherein when the ratio between the minimum value and the maximum value becomes equal to or less than the reference value, a failure occurs. A fan device that outputs a signal indicating the following. 2. A plurality of fans, a temperature detecting unit for detecting a temperature, a rotation speed detecting unit for detecting a rotation speed for each fan, a fan control unit for controlling increase and decrease of the rotation speed of the fan, and a failure of the fan. A storage unit for storing the detection value, a calculation unit for calculating a ratio between the minimum value and the maximum value of the fan rotation speed, and a magnitude of the failure detection value stored in the storage unit and a value of the ratio calculated by the calculation unit; The blower fan device provided with a determination unit for determining the condition. 3. The operation unit calculates an average rotation speed based on the rotation speed of each fan, further calculates a ratio between a minimum value of the fan rotation speed and the average rotation speed, and stores a ratio of the fan rotation number in the storage unit. 3. The blower fan device according to claim 2, wherein the two failure detection values are stored, and the determination unit determines the magnitude of the second failure detection value and the value of the ratio calculated by the calculation unit. 4. The blower fan device according to claim 2, wherein the rotation speed detecting section is configured to sequentially calculate an average rotation speed of the fan for a predetermined time for each fan. 5. The blower fan device according to claim 2, wherein the fan is configured to continuously change the number of revolutions according to the temperature.