JPH07122057A - Recording disk driving device - Google Patents

Abstract

PURPOSE:To improve the flow and cooling efficiency of air and to decrease the number of revolutions, noise and electric power consumption of a discharge fan by forming the cross sections of respective columnar members of an air intake port and of discharge port in streamline shapes. CONSTITUTION:A casing A is provided with the air intake port 6, air discharge port 7 and discharge fan 3 for passing the air for cooling heating elements, such as CPU and IC, on a circuit board part 2 for controlling a drive mechanism part. The cross sections of the columnar members 4a, 5a of the intake port 6 and discharge port 7 of the casing A through which the air flows are composed of arbitrarily curved surfaces free from angles. Namely, the cross sections of the columnar members are formed to the streamline shapes which extend slender in the direction of the flow and are extremely small in the air resistance to the flow. As a result, the recirculating region accompanying the vortexes around the members 4a, 5a are eliminated and the flow of the air is smoothed. The cooling efficiency is thus enhanced, the number of revolutions of the fan 3 is lowered and the noises and electric power consumption are reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording disk drive device for driving a recording disk such as an optical disk and a magneto-optical disk for recording / reproducing, and more particularly to an air cooling device thereof.

[0002]

2. Description of the Related Art Conventionally, it has been proposed to use an air flow to cool a circuit board portion of an optical disk drive, as disclosed in Japanese Patent Laid-Open No. 3-173989.

FIG. 10 is a vertical cross-sectional view of a conventional optical disk drive, and FIG. 11 is a horizontal cross-sectional view thereof. In a case A, information is recorded / reproduced on / from a disk-shaped recording medium by using a laser beam. An optical system for performing, a drive mechanism for this optical system, a spindle motor with a turntable, a loading mechanism for a disk-shaped recording medium, etc. (each part is not shown),
Completely sealed drive mechanism unit 1 and drive mechanism unit 1
A circuit board unit 2 which is separated from and controls the drive mechanism unit 1.
And the exhaust fan 3 arranged on the side of the circuit board portion 2.
And are housed.

On one side wall 4 of the housing A, as shown in FIG. 11, a large number of air intakes 6 are formed at predetermined intervals over the entire width. The side wall 4 is divided at predetermined intervals by the air intake port 6 to form a columnar member 4a. On the other hand, the other side wall 5 is also formed with a plurality of air discharge ports 7 at predetermined intervals in the center thereof, and the side wall 5 is formed with a columnar member 5a.

In such a structure, the outside air taken in from the air intake port 6 by the exhaust fan 3 passes only inside the circuit board portion 2, cools a heat generating element such as an IC on the circuit board, and exhausts the air. It is discharged from the outlet 7 to the outside. The arrows represent the streamlines of the air flow.

[0006]

However, in the above-mentioned optical disk drive device, the heating element on the circuit board is used.
Taking heat from the airflow (especially, an IC such as a CPU or a power transistor) to cool it requires a large amount of air to be sent.

FIG. 12 is a schematic view showing a vortex generated in a conventional air flow. Since the cross section of the columnar member 4a (or 5a) in the direction of air flow has a square shape as shown in FIG. , A recirculation region 12 in which air swirls and flows backward with respect to the direction of the air flow, thereby increasing the air resistance.

Therefore, even if the airflow is smooth, a large amount of airflow must be generated, and the increased air resistance causes the exhaust fan 3 to rotate even more. Power increases,
Power consumption and noise and vibration caused by airflow are problems.

An object of the present invention is to provide a recording disk drive device capable of efficiently cooling a heating element even if the rotation speed of an exhaust fan is reduced.

[0010]

To achieve the above object, the present invention provides an optical system for recording / reproducing information on / from a disc-shaped recording medium by using a laser beam, and a drive mechanism for this optical system. A spindle motor provided with a turntable, a loading mechanism for the disk-shaped recording medium, a drive mechanism section completely sealed by a dustproof cover, and a circuit board section for driving and controlling the drive mechanism section,
In order to allow forced cooling air to flow through the circuit board portion, a large number of air intake openings are formed on one side wall of the housing that houses the drive mechanism section and the circuit board section, and a large number of air discharge openings are formed on the other side wall. And a recording disk drive device including an air-cooling unit having an exhaust fan for flowing air, the cross-section of the columnar member between at least the air intakes adjacent to each other having a streamline shape in a direction in which the air flows. It is characterized by having done.

Further, the columnar members having a streamlined cross section are arranged in a staggered manner in the direction of air flow.

A rectifying rib for intensively cooling the heating element is provided on the circuit board portion.

Further, a protrusion having a substantially triangular cross section for intensively cooling the heating element is provided on the circuit board portion.

A rhombus-shaped projection array for intensively cooling the heating element is provided on the circuit board portion.

[0015]

According to the recording disk drive apparatus having the above construction, since the columnar member has a streamlined shape, the air resistance of the flowing air is reduced.

Further, by arranging the streamlined columnar members in a staggered arrangement, the air resistance of the flowing air is further reduced.

Further, the components which generate a particularly large amount of heat on the circuit board are intensively cooled by the rectifying ribs for intensively guiding the air flow, the cooling efficiency is enhanced, and the use of the flowing air is efficient. Done

Further, a substantially triangular protrusion is provided in front of the flow of the air flow of a component on the circuit board having a particularly large amount of heat generation, and the air flow separated by the substantially triangular protrusion is redeposited on the circuit board. The efficiency of cooling is increased by installing the parts at the points where the cooling is performed.

Further, by arranging the diamond-shaped projection row in front of the flow of the air flow of the component having a particularly large heat generation amount on the circuit board, the air flow near the component is disturbed and the air flow from the component is disturbed. The efficiency of convective heat transfer to the is improved and the efficiency of cooling is increased.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. The same parts as those in the conventional example are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 1 is a transverse cross-sectional view of a first embodiment of a recording disk drive device of the present invention. The cross-sections of the columnar members 4a and 5a at the air intake port 6 and the air exhaust port 7 are arbitrary curved surfaces without corners. It has a streamlined shape that is elongated in the flow direction and has very low air resistance to the flow.

FIG. 2 is a schematic diagram showing the flow and velocity distribution of air in the first embodiment. When the air taken into the apparatus for cooling the circuit board portion 2 is taken in and when it is discharged, Around the columnar members 4a, 5a forming the lattice-shaped air intake port 6 and the air exhaust port 7, a recirculation region accompanied by a vortex does not occur, the flow becomes smooth, and the air resistance is reduced. .

FIG. 3 is a cross-sectional view of a second embodiment of the present invention, and FIG. 4 is a schematic view showing the air flow and velocity distribution thereof. The columnar members 4a and 5a are arranged one by one in the air flowing direction. And they are arranged in a staggered pattern.

As shown in FIG. 2, when streamline-shaped columnar members 4a and 5a are arranged in one row, the velocity distribution has a large drop in velocity (a portion that is slower than the ambient flow velocity). However, when the streamlined columnar members 4a and 5a are arranged in a zigzag manner as shown in FIG. 4, the speed drop portion is smaller than that in FIG. 2, and the drop rate is also small. . The large drop in velocity causes resistance to the flow of the air flow, so
By arranging the streamlined columnar members 4a and 5a as shown in FIG. 4, the flow of the air flow becomes smoother than in the first embodiment, and the air resistance is reduced.

FIG. 5 is a perspective view of a circuit board portion according to a third embodiment of the present invention, and 8 is a circuit component which generates a particularly large amount of heat. The arrows in the figure represent the flow of air flow for cooling the circuit board 2. Two rectifying ribs 9 are mounted on the circuit board 2 on the upstream side of the air flow of the component 8 so as to intensively guide the air flow to the component 8. The shape of the rectification rib 9 is configured by a straight line or an arbitrary curve, and the interval between the two is wide on the upstream side of the air flow, and is narrowed to substantially the same width as the width of the component 8 immediately before the component 8. The structure is such that a large amount of cooling air is guided to the component 8. As a result, the components 8 are intensively cooled by the cooling air, and the cooling efficiency of the entire apparatus is improved.

When the heat is taken by the air flow to perform cooling, the heat transfer coefficient is generally used to represent the efficiency. The heat transfer coefficient h (Kcal / m ² · h · ° C) is the surface temperature of the substrate T
If w (℃), the temperature of flowing air is Tf (℃), and the heat flux on the substrate surface is q (Kcal / m ² · h),

[0027]

## EQU1 ## h = (Tf-Tw) / q. The larger the heat transfer coefficient h, the better the cooling effect.

FIG. 6 is a perspective view of a circuit board portion according to a fourth embodiment of the present invention, in which a substantially triangular protrusion is provided on the upstream side with respect to the air flow of the component 8 having a particularly large heat generation amount in the circuit components.
10 is installed on the circuit board unit 2. The shape of the protrusion 10 is a slope shape in which the upstream side is formed by a straight line or an arbitrary curve, and the downstream side, that is, the component 8 side is vertically cut off.

FIG. 7 is a schematic diagram showing the state of the air flow and the heat transfer coefficient in the fourth embodiment. The cooling air flow flows on the circuit board portion 2 and reaches the protrusions 10, and after the protrusions 10. It peels off at the end, becomes a downward flow toward the circuit board portion 2, and hits the upper surface of the component 8. This phenomenon is called reattachment, and the interval between the protrusion 10 and the component 8 is set so that the component 8 is installed at the point where the air flow reattaches.

By doing so, as shown in the figure, the heat transfer coefficient on the component 8 becomes large. With this configuration, the component 8 is intensively cooled by the cooling air. The efficiency of cooling the entire device is improved.

FIG. 8 is a perspective view of a circuit board portion according to a fifth embodiment of the present invention. A diamond-shaped projection array 11 is provided on the upstream side of the air flow of the component 8, and the diamond-shaped diagonal line indicates the air flow. Several are installed at appropriate intervals so as to be parallel to the flow direction of.

FIG. 9 is a schematic view showing the state of the air flow and the heat transfer coefficient in the fifth embodiment. When the cooling air flow flows on the circuit board portion 2 and reaches the projection row 11, after that, On the one hand, it becomes a flow with a three-dimensional disturbed vortex. Due to this three-dimensional disturbance, convection heat transfer is promoted, and as shown in the figure, the heat transfer coefficient on the component 8 becomes large. With this configuration, the component 8 is concentrated by the cooling air. Cooling improves the efficiency of cooling of the entire device.

[0033]

As described above, in the recording disk drive apparatus of the present invention, according to the invention described in claim 1, at least the cross section of the columnar member on the air intake side with respect to the air flowing direction is streamlined. As a result, the air resistance of the flowing air can be reduced. Therefore, even if the rotation speed of the exhaust fan is reduced, a relatively large amount of air can be sent to the circuit board portion, so that it is possible to reduce power consumption and prevent noise and vibration caused by the air flow. It will be possible.

According to the second aspect of the present invention, the streamlined columnar members are arranged in a staggered arrangement, whereby the air resistance of the flowing air can be further reduced, and therefore the same effect as described above can be obtained. You can

According to the third aspect of the present invention, the components that generate a particularly large amount of heat on the circuit board are intensively cooled by the rectifying ribs for intensively guiding the air flow to enhance the cooling efficiency. Since the flowing air can be used efficiently,
The same effect as the above can be exhibited.

According to the fourth aspect of the present invention, a substantially triangular protrusion is provided in front of the air flow of a component having a particularly large heat generation amount on the circuit board, and the air separated by the substantially triangular protrusion is used. Since the cooling efficiency can be increased by providing the component at the point where the flow reattaches to the circuit board, the same effect as described above can be obtained.

According to the fifth aspect of the present invention, by disposing the diamond-shaped projection row in front of the air flow of the component having a particularly large heat generation amount on the circuit board, the air flow in the vicinity of the component is eliminated. Since the efficiency of convection heat transfer from the components to the air flow can be improved and the efficiency of cooling can be improved, the same effect as described above can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a first embodiment of a recording disk drive device of the present invention.

FIG. 2 is a schematic diagram showing an air flow and velocity distribution in the first embodiment.

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

FIG. 4 is a schematic diagram showing an air flow and a velocity distribution in the second embodiment.

FIG. 5 is a perspective view of a circuit board portion according to a third embodiment of the present invention.

FIG. 6 is a perspective view of a circuit board portion according to a fourth embodiment of the present invention.

FIG. 7 is a schematic diagram showing an air flow and a heat transfer coefficient in a fourth embodiment.

FIG. 8 is a perspective view of a circuit board portion according to a fifth embodiment of the present invention.

FIG. 9 is a schematic diagram showing an air flow and a heat transfer coefficient in the fifth embodiment.

FIG. 10 is a vertical cross-sectional view of a conventional optical disk drive device.

FIG. 11 is a cross-sectional view of a conventional optical disk drive device.

FIG. 12 is a schematic diagram showing vortices generated in a conventional air flow.

[Explanation of symbols]

A ... Case, 1 ... Drive mechanism section, 2 ... Circuit board section,
3 ... Exhaust fan, 4a, 5a ... Columnar member, 6 ... Air intake port, 7 ... Air discharge port, 9 ... Straightening rib, 10 ...
Protrusion, 11 ... Protrusion row.

Claims (5)

[Claims] 1. An optical system for recording / reproducing information on / from a disc-shaped recording medium by using laser light, a drive mechanism of the optical system, a spindle motor having a turntable, and the disc-shaped recording. A medium loading mechanism, a drive mechanism section completely sealed by a dustproof cover, a circuit board section for driving and controlling the drive mechanism section,
In order to allow forced cooling air to flow through the circuit board portion, a large number of air intake openings are formed on one side wall of the housing that houses the drive mechanism section and the circuit board section, and a large number of air discharge openings are formed on the other side wall. And a recording disk drive device including an air-cooling unit having an exhaust fan for flowing air, the cross-section of the columnar member between at least the air intakes adjacent to each other having a streamline shape in a direction in which the air flows. A recording disk drive device characterized by the above. 2. The recording disk drive device according to claim 1, wherein the columnar members having a streamlined cross section are arranged in a staggered manner in a direction in which air flows. 3. The recording disk drive device according to claim 1, further comprising a rectifying rib provided on the circuit board portion for intensively cooling the heating element. 4. The recording disk drive device according to claim 1, wherein a protrusion having a substantially triangular cross section for intensively cooling the heating element is provided on the circuit board portion. 5. The recording disk drive device according to claim 1, wherein a diamond-shaped projection array for intensively cooling the heating element is provided on the circuit board portion.