JP2515980Y2 - Heat dissipation device for in-vehicle electronic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a heat dissipation device that actively cools the temperature of a heat generating portion when the temperature inside the electronic device during operation rises.

[Prior Art] Active elements such as semiconductors used in electronic devices or active components with large power consumption generate a large amount of heat in proportion to electric power. On the other hand, passive components do not generate heat by themselves,
Many of them have characteristics that are easily affected by the ambient temperature.

For example, since a vehicle-mounted cassette player is designed to be small and compact, heat generated from heat-generating components such as a motor affects not only active components but also a cassette tape used in the player.

Therefore, in such a device, structural measures are taken such as isolating the heat generating part so that the temperature of the heat generating part does not affect other parts, or the heat of the heat generating part is actively dissipated to the outside. A cooling fan may be installed.

[Problems to be solved by the invention] By the way, since the cassette tape used in the player is based on a thermoplastic resin, it is easily affected by heat, and is mounted when the temperature rise of the player exceeds a predetermined value. It may transform into a seaweed. Also,
If the user of the player feels hot when touching the tape, even if the temperature does not rise enough to deform the tape,
It will give the user a sense of distrust.

Generally, a cooling fan is attached to a device in order to solve such a problem, but a fan driving motor is required to have high durability and reliability. However, such a motor is generally expensive, and it is difficult to adopt such a motor in a consumer device in which the pursuit of cost must be considered.

The present invention has been made in view of the above circumstances, and is configured to operate the cooling fan only when the temperature rise of the device exceeds the preset temperature when the recording medium is mounted, and thereby the ambient temperature is increased. It is an object of the present invention to provide a heat dissipation device for an electronic device that protects passive components and expensive music tapes whose characteristics are easily affected by the above, and that can maintain the durability of a fan drive motor.

[Means for Solving the Problems] In order to achieve the above object, in a heat dissipation device for an on-vehicle electronic device of the present invention, a temperature sensor for detecting a temperature inside the electronic device and a determination means for detecting a mounting state of a recording medium are provided. And a control unit that operates the fan based on the output of the temperature sensor and the output of the determination unit.

[Operation] The cooling fan provided on the side of the heat generating portion is driven based on the set temperature inside the device detected by the temperature sensor. The temperature detected by the temperature sensor is preset to a predetermined value, and when the temperature inside the device exceeds the predetermined value, the sensor outputs a detection signal to the control unit and the cooling fan operates.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 and 2 are views showing an on-vehicle cassette player,
FIG. 1 is a top view of the player, and FIG. 2 is a side view thereof.

In the figure, 10 is a cassette mechanism attached to a substrate 12. The mechanism 10 is housed in a case 11. The central portion of the mechanism 10 is a tape loading portion 14 for loading the cassette tape at the reproducing position, and the tape is inserted in the longitudinal direction from the tape insertion opening 16 on the right side shown in FIG.

Reference numeral 18 denotes a pair of motors that drive the capstan shaft and the reel shaft separately, and have a drive torque characteristic required for tape running. A fan 20 for cooling the motor is provided on the side of the motor 18. The fan 20 is rotationally driven in a direction in which the air inside the device is blown out of the case 11. A temperature sensor 22 for detecting the ambient temperature of the tape is provided above the cassette tape mounting portion 14.

FIG. 3 is a block diagram of an electric circuit including the cassette mechanism 10. The same components as those shown in FIGS. 1 and 2 are designated by the same reference numerals. In the figure, reference numeral 30 is a cassette tape insertion detection unit that gives a detection signal to the control unit 36 when the cassette tape is loaded in the loading unit 14. Reference numeral 32 is a power switch of the cassette player, 34 is an operation section for performing various operations such as tape reproduction and running, and 38 is a fan power switch for supplying power to the fan 20, when a command is given from the control section 36. Power is supplied to the fan motor 20a to rotate the fan 20.

The temperature sensor 22 provided on the tape mounting portion 14 has a detection temperature set in advance so as to output a detection signal to the control portion 36 when a predetermined ambient temperature is detected. This detected temperature is set to be equal to the temperature obtained by adding 20 ° C. to the vehicle interior temperature, for example.

Next, the operation of the device will be described with reference to the flowchart of FIG. In step 1 (S-1), the cassette insertion detection unit 30 constantly monitors the tape loading state of the tape loading unit 14, and when the tape is loaded, the detection signal is sent to the control unit 36.
Give to. When the control unit 36 determines that the tape is loaded, it further determines whether the power switch 32 of the player body is turned on or not (S-2).

At this time, if the main body is not powered on, the process returns to step 1 and the tape insertion state is determined again. When power is supplied to the player and tape playback is performed,
The motor 18 that drives the tape running mechanism gradually generates heat. When the tape is played for a long time, the surface temperature of the motor 18 rises, and this heat is the mechanism.
After being transmitted to the inside of the tape 10, the ambient temperature of the tape mounting portion 14 also rises.

Temperature sensor 22 mounted above the tape mounting part 14
Always monitors the temperature of the tape mounting portion 14, but when the ambient temperature exceeds a predetermined temperature set in advance, a detection signal indicating that the temperature is equal to or higher than a set value is output to the control portion 36 ( S-3).

As a result, the control unit 36 closes the fan power switch 38 and drives the fan motor 20a to operate the fan 20 (S-4).

If it is determined in step 3 that the ambient temperature of the tape loading section 14 is below the set value and the tape is being reproduced, the control section 36
Always looks at whether the fan 20 is operating (S-5).

Then, if the fan 20 is operating, the operation of the fan 20 is stopped (S-6), the process returns to step 3 again, and the observation of the ambient temperature is continued.

When the ambient temperature around the tape loading section 14 exceeds the specified value, the fan
When the driving of 20 is started, the air around the motor 18 is discharged to the outside of the case 11.

As a result, the inside of the case 11 is in a negative pressure state, and new air from the outside flows in from the opening including the tape insertion opening 16.
Cool the tape mounting section 14.

Therefore, since the motor 18, which is the heat generating portion, is rapidly cooled, the ambient temperature of the mechanism portion and the tape mounting portion 14 is gradually lowered, and the player is kept at the normal temperature and the tape reproduction is continued.

Here, when the tape reproduction is finished, the power is turned off by operating the power switch 32 of the player main body.
Further performs an operation of determining the power off state (S-
7).

When the power switch is cut off, the operation of the fan 20 also stops (S-9).

However, when the tape reproduction is continued without shutting off the power switch 32, the tape eject determination function for detecting that the tape is ejected from the mounting portion 14 operates (S
-8).

This function provides an eject signal to the control unit 36 in conjunction with the tape eject mechanism, and when the tape is ejected, the operation of the fan 20 is stopped regardless of whether the power switch of the player body is opened or closed. . Then, when the tape is mounted on the mounting portion, step 3 is performed again.
Then, if the temperature is equal to or higher than the set value, the fan 20 operates.

Therefore, according to this function, the fan 20 can operate when the tape is loaded in the loading portion 14, protects the tape from a high temperature damage given to the tape, and when the tape is not present, that is, the tape reproduction is not performed. When it is not performed, the temperature of the motor does not rise, so that useless fan operation can be stopped.

The heat dissipation device of the present invention has been described by taking a cassette player as an example, but it goes without saying that the present invention can be applied to a recording / reproducing device such as a VTR or a DAT that uses a magnetic tape.

[Advantages of the Invention] As described above, according to the heat dissipation device for a vehicle-mounted electronic device of the present invention, a temperature sensor that detects the temperature inside the electronic device, a determination unit that detects the mounting state of the recording medium, and Since the controller that operates the fan based on the output of the temperature sensor and the output of the determination means is provided, the temperature sensor monitors the internal temperature of the device when the recording medium is mounted, and the ambient temperature is a predetermined value. When this is detected, the fan can be driven to cool the heat generating portion, and electronic components that are affected by heat and whose characteristics are likely to change can be protected from temperature.

In addition, unexpected accidents such as the reproduced tape being exposed to high temperature and being damaged will not occur. Further, since the cooling fan is operated only when the temperature inside the device exceeds a predetermined value, the durability of the fan drive motor can be assured even if a fan whose cost is suppressed is adopted.

[Brief description of drawings]

FIG. 1 is a top view of the cassette player, and FIG. 2 is a side view thereof. FIG. 3 is a block diagram of an electric circuit for controlling the heat dissipation device, and FIG. 4 is a flow chart for explaining the operation. 10 …… Cassette mechanism, 14 …… Tape loading section, 18…
… Motor, 20 …… fan, 22 …… temperature sensor, 36 …… control section.

Claims (1)

(57) [Scope of utility model registration request] 1. A temperature sensor for detecting a temperature inside an electronic device, a judging means for detecting a mounting state of a recording medium, and a controller for operating a fan based on an output of the temperature sensor and an output of the judging means. And a heat dissipation device for an in-vehicle electronic device.