JPH05275876A - Cooling apparatus - Google Patents

Abstract

PURPOSE:To make it possible to place an electric part near to an ultrasonic motor and cool an inside of electric equipment with low power consumption, by providing a driving circuit on a board for supplying the ultrasonic motor with an electric signal to rotate a fan-shaped rotor thereof. CONSTITUTION:An ultrasonic motor as a cooling unit is made up of an oscillator 1 having a plurality of electrodes, a first rotor 2, and a second rotor 3. A voltage of sine wave signal or cosine wave signal is applied to each electrode so that the oscillator 1 is expanded or shrunk by distortion in accordance with the frequency of the signals. Then, the first and second rotors 2 and 3 are rotated when the oscillator 1 is fitted to the first and second rotors 2 and 3 through the expanding or shrinking operation. The ultrasonic motor is mounted on a board 6, and air pipe holes 5A to 5C are also formed on the board. Consequently, the heat from an electric part is diffused on the board by rotating the fan-shaped rotor 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device which is arranged in an electric device and cools the temperature inside the electric device caused by heat generation of an electric component or the like.

[0002]

2. Description of the Related Art Generally, in portable electric equipment, components such as ICs are mounted at high density on a control board provided inside in order to reduce the size and thickness. When the components are mounted at a high density in this manner, it is necessary to handle not only electromagnetic noise but also heat generated from the components. In particular, in the case of portable electric equipment, since the board on which the components are mounted is sealed inside the equipment, heat tends to be trapped inside, and even if an attempt is made to dissipate the heat, the space becomes narrow due to the high-density mounting of the components. Therefore, air convection is less likely to occur.

[0003]

For this reason, if the components that generate a large amount of heat are dispersed and the components that are weak to heat are placed away from the vicinity of the components that generate a large amount of heat, the board becomes large and the device becomes large. There was a problem to do. If a cooling fan that operates with a DC motor is attached to the casing of an electric device to remove heat from the inside, electromagnetic noise from the DC motor will affect the internal parts and cause malfunctions. Therefore, separate the parts from the DC motor. Need to be placed. Therefore, in order to cool the parts away from these DC motors, it is necessary to apply a large amount of electric power to the DC motors to increase the cooling capacity, which makes it difficult to reduce the power consumption of the device.

[0004]

In order to solve such a problem, the present invention uses an ultrasonic motor as a cooling device and disposes the ultrasonic motor on a substrate on which electric parts are mounted. A fan-shaped rotor provided in the motor and a drive circuit for applying an electric signal to the ultrasonic motor to rotate the rotor are provided.

[0005]

Since the ultrasonic motor having the fan-shaped rotor is arranged on the substrate as a cooling device, it is not necessary to consider the arrangement of the electric parts on the substrate, and electromagnetic noise is not generated. Since electric parts can be arranged near the motor, the electric equipment can be cooled with a small amount of electric power.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 3 is a diagram showing an embodiment of the present invention and is a diagram showing a configuration of an ultrasonic motor used as a cooling device. As shown in (a) of the same figure, this ultrasonic motor is composed of a vibrator 1, a first rotor (rotor) 2, and a second rotor 3 that is in contact with the first rotor 2. Has been done. The vibrator 1 is provided with a plurality of electrodes, and when voltages of a sine wave signal and a cosine wave signal are applied to each of these electrodes, the vibrator 1 is distorted and expanded according to the frequency of the signal. When the vibrator 1 comes into contact with the first rotor 2 and the second rotor 3 by the expansion and contraction operation of the vibrator 1, the first rotor 2 and the second rotor 3 rotate.

This ultrasonic motor has an I
The first rotor 2 is arranged on a substrate on which electric components such as C are mounted, and is formed in a fan shape. Further, three air circulation holes 5A to 5C are provided on the substrate so that the heat generated by the electric component can be diffused by the rotation of the fan-shaped rotor 2. FIG. 3B is a cross-sectional view of the ultrasonic motor arranged on the substrate. 5 is the above-mentioned air circulation hole, 6 is the substrate, and 7 is rubber for bonding the vibrator 1 and the substrate 6 together. A system adhesive, 8 is a shaft for fixing the ultrasonic motor to the substrate, 9 is a nut, and 10 is a spring. In this case, if the outer diameter and the thickness of the vibrator 1 are 8 mm and 1 mm, respectively, the fan-shaped rotor 2
The outer diameter and height of are 11 mm and 8.5 mm, respectively,
The outer diameter and thickness of the vibrator 1 are 15 mm, 1.
When the thickness is 5 mm, it is desirable that the outer diameter and the height of the fan-shaped rotor 2 are 20 mm and 9 mm, respectively. In this way, the ultrasonic motor is mounted on the substrate 6, the air circulation holes 5A to 5C are provided on the substrate, and the fan-shaped rotor 2 is rotated, so that the heat generated from the electric components mounted on the substrate 6 is generated. It is designed to diffuse.

Next, FIG. 4 is a diagram showing the arrangement of components on the substrate 6. In FIG. 4, IC1 to IC6 are electrical components such as integrated circuits, and 20 is an ultrasonic motor 20 having a fan-shaped rotor 2. Is shown. This ultrasonic motor 20
Since it does not generate electromagnetic noise, each electric component can be freely arranged nearby. Therefore, it is possible to arrange the electric components in the order of increasing heat generation in the vicinity of the ultrasonic motor 20, and it is possible to diffuse the heat generated by the electric components with less electric power. Further, the ultrasonic motor 20 is thinner and smaller than the DC motor, and even if it is applied as a cooling device for a portable electric device, the thinning of the portable device is not impaired.

Next, FIG. 1 is a block diagram of a driving device for driving an ultrasonic motor provided on a substrate 6 as a cooling device. In the figure, the CPU 21 outputs the pulse signals having different phases from the timer output terminals A and B to the driver unit 23 via the buffer unit 22 by the built-in timer. The driver section 23 receives these two pulse signals having different phases and gives them to the electrodes provided on the vibrator 1 in the ultrasonic motor 20. As a result, the fan-shaped first rotor 2 rotates.

Next, FIG. 2 is a block diagram showing another embodiment of the above-mentioned driving device, in place of the CPU 21, a timer section 25, an inverter 26 and a binary counter section 27.
Is provided and the two pulse signals having different phase differences as described above are given to the driver section 23 to rotate the ultrasonic motor 20. The driver unit 23
Can be simply configured by the two transistors Q1 and Q2.

[0011]

As described above, according to the present invention, the ultrasonic motor having the fan-shaped rotor is arranged as the cooling device on the substrate on which the electric parts are mounted, and as a result, the heat generation amount can be adjusted. Since distributed arrangement of electric parts is not required and electric equipment can be downsized, and electromagnetic noise is not generated, electric parts can be arranged in the vicinity of the ultrasonic motor, and therefore the electric equipment can be cooled with less electric power. It will be possible.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a cooling device according to the present invention.

FIG. 2 is a block diagram showing another embodiment of the cooling device.

FIG. 3 is a diagram showing a configuration of an ultrasonic motor used as a cooling device.

FIG. 4 is a diagram showing an arrangement state of the ultrasonic motor and electric components cooled by the ultrasonic motor on a substrate.

[Explanation of symbols]

 1 Vibrator 2,3 Rotor 5A-5C Air flow hole 6 Substrate 20 Ultrasonic motor 21 CPU 22 Buffer part 23 Driver part 25 Timer part 26 Inverter 27 Binary counter part

Claims (1)

[Claims] 1. A cooling device for diffusing heat generated by an electric component mounted on a board in an electric device to cool the temperature in the electric device, wherein an ultrasonic motor is used as the cooling device. A cooling characterized by comprising a fan-shaped rotor provided on the substrate and provided inside the ultrasonic motor, and a drive circuit for applying an electric signal to the ultrasonic motor to rotate the rotor. apparatus.