JPH0430498Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a heat dissipation device for a meter installed inside a lighting lamp mounted on a vehicle, for example.

[Technical background of the invention and its problems]

Traditionally, for example, vehicle instruments have been equipped with lamps for night illumination, and in recent years, transilluminated instruments using liquid crystal cells have had to be illuminated during the day as well. Lamps are now being installed.

The increase in the number of lighting lamps causes the temperature inside the instrument case to rise significantly due to the heat generated by them, causing problems such as interfering with the indications of the instruments or, in the worst case, destroying the internal mechanism. A structure is required to suppress the rise as much as possible.

Conventionally, the general structure was to radiate the heat from the lighting lamp to the outside of the case using a heat sink or by providing ventilation holes in the case, but it was not possible to obtain a sufficient heat radiation effect, and furthermore, the ventilation holes were not provided at all times. Since it is open, there is a problem that dust can enter and contaminate the internal unit, and it also has the disadvantage that it cannot provide a heat dissipation function because it is limited by the small ventilation holes.

[Purpose of invention]

The object of the present invention is to provide a heat dissipation structure that can suppress the intrusion of dust as much as possible while providing ventilation holes in an instrument case that can properly dissipate heat according to the number of internal lighting lamps and the amount of heat generated.

[Summary of the idea]

The present invention forms a ventilation hole for heat radiation in the instrument case, provides a movable control plate for opening and closing the ventilation hole, and connects a return spring member and a shape memory alloy activation spring member to the control plate. The control plate is characterized in that the movement of the control plate is controlled by a reversal action of the spring force due to a temperature change inside the instrument case.

[Example of idea]

FIG. 1 shows a preferred embodiment of the present invention.
The instrument case 1 stores and fixes the indicator 2 inside, and has a dial 3 on its open front to enable measurement instructions by turning the pointer 4. A dial 5 hides the inner unit and provides transparent protection. It is covered by a plate 6.

Furthermore, illumination lamps 7 are installed at the bottom of the instrument case 1 in a required number and at appropriate positions to ensure the required brightness depending on the number of instruments 2 and the size of the case 1.

A vent hole 8 communicating with the outside is formed on the side wall of the instrument case 1, preferably near the location where the illumination lamp 7 is arranged, and inside the vent hole 8 is slidable along the inner wall of the case 1 to open and close the vent hole 8. A control plate 9 supported by is provided.

The vent hole 8 has a sufficient open area to suppress a significant temperature rise within the instrument case 1, and is formed, for example, by a number of parallel slits 10, as shown in FIG.

The control plate 9 has a large number of slits 11 for opening and closing corresponding to the slits 10, and has a return spring member 12 and one end of an operating spring member 13 made of a shape memory alloy on both sides in the sliding direction. The other ends of each spring member 12 and 13 are fixed to the instrument case 1 side.

The opening and closing of the ventilation hole 8, that is, the slit 10, by sliding the control plate 9 is controlled by the respective spring members 12, 1.
This is done by the reversal action of the spring force due to the ambient temperature. That is, the actuating spring member 13 made of a shape memory alloy restores to its memorized shape in a high temperature environment with a set temperature of, for example, 80° C. or higher, and the restoring force at that time resists the spring force of the restoring spring member 12 and causes the slit 10 to be restored. Move the control board 9 to the position where it opens. Also, 80℃
In the following room temperature environment, the shape memory effect of the actuating spring 13 is canceled and its restoring force is also lost, making it easy to deform. Therefore, the control plate 9 is moved to the position where the slit 10 is closed by the spring force of the return spring member 12. Moving.

3A and 3B illustrate the opening/closing state of the slit 10 by the control board 9, and show that even when the illumination lamp 7 inside the instrument case 1 is turned off or turned on, the temperature inside the case 1 will rise within the normal temperature range. , the shape memory alloy operating spring member 13 is in a state where it is easily deformed, and the spring force of the return spring member 12 pushes the control plate 9 through the slit 10 as shown in FIG.
hold in the closed position. In other words, the slit 10 on the instrument case 1 side and the slit 11 on the control panel 9 side mutually overlap with the other partition wall and block communication with the outside, and if the ventilation hole 8 is not formed, the same closed state will be maintained. Prevent dust from entering from outside.

When the temperature inside the instrument case 1 rises significantly due to continued lighting of the illumination lamp 7, the function of restoring the shape memory alloy actuating spring member 13 to the memorized shape is activated, and the restoring force is applied to the spring force of the restoring spring member 12. The control plate 9 is moved to the open position of the rim 10 as shown in FIG. In other words, instrument case 1
The side slit 10 and the slit 11 of the control plate 9 overlap to establish communication with the outside, and communication with the outside is maintained until the surrounding environment of the actuating spring member 13, that is, the temperature inside the case 1 drops to the normal temperature range. do.

Therefore, a large number of slits 10 and slits 1
By opening the vent hole 8 formed by the vent hole 8, the high-temperature air layer inside the instrument case 1 is dissipated to the outside, and the circulation with the external cold air through the vent hole 8 reduces the significant temperature inside the instrument case 1 for a long time. The rise can be suppressed.

When the temperature inside the case 1 drops due to heat dissipation from inside the case 1 through the open ventilation holes 8, the restoring force of the shape memory alloy operating spring member 13 is lost and the control plate 9 becomes easily deformed. The vent hole 8 is moved to the closed position by the spring force of the return spring member 12, and returned to the closed state shown in FIG.

In this way, due to the reversal of the spring force of the return spring member 12 and the actuation spring member 13 due to the ambient temperature, the vent hole 8 is closed in a room temperature environment to prevent dust from entering from the outside, and in a high temperature environment, the vent hole 8 is closed. Automatic opening/closing control is performed to open the instrument case 1 and suppress a significant rise in temperature within the instrument case 1.

In addition, in order to ensure the opening/closing sliding position of the control plate 9, it is sufficient to form a stopper on the case 1 side, and each spring member 12, 13 does not have to be directly connected to the control plate 9, but can be connected to a cam or a connecting rod, for example. It may also be configured to be indirectly connected to the control board 9 via the control board 9.

[Effect of idea]

As described above, the present invention automatically controls the opening and closing of the vent hole in the instrument case by moving the control board by reversing the spring force due to temperature changes between the return spring member and the shape memory alloy active spring member. With this configuration, it is possible to effectively suppress the significant temperature rise caused by lighting the lighting lamp inside the instrument case.
Furthermore, by opening the ventilation holes only when necessary, it is possible to provide a heat dissipation device with extremely high practical value, which can effectively prevent dust from entering from the outside.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an embodiment of an instrument device equipped with a heat dissipation device according to the present invention, Fig. 2 is a structural diagram of a main part of the heat dissipation device with a part of the heat dissipation device in cross section, and Figs. 3A and B are It is an explanatory view explaining operation of the heat dissipation device. DESCRIPTION OF SYMBOLS 1... Instrument case, 2... Indication instrument, 5... End plate, 6... Transparent protection plate, 7... Lighting lamp, 8... Ventilation hole, 9... Control board, 10, 11...
...slit, 12... spring member for return, 13...
A dynamic spring member made of shape memory alloy.

Claims (1)

[Scope of utility model registration request] A vent hole communicating with the outside formed in an instrument case containing a lighting lamp, and a control board movably disposed to control closing and opening of the vent hole;
a return spring member connected to the control plate and fixed to the case side to restrain the control plate in the closed position of the vent; and a return spring member connected to the control plate and fixed to the case side to memorize the shape in a high temperature environment. When the control plate is moved to the vent open position against the spring force of the return spring member, and when the memory is canceled in a normal temperature environment, the shape memory alloy is made of a shape memory alloy that can be deformed to the vent open position by the spring force of the return spring member. A heat dissipation device for an instrument consisting of a dynamic spring member.