JPH04344716A - Small-sized radio equipment - Google Patents

Abstract

PURPOSE:To miniaturize an equipment by using a coaxial cable connected to the equipment main body as a heat sink so as to omit a heat sink at the rear side of the equipment main body. CONSTITUTION:The coaxial cable 1 of a cylindrical shape is threaded to the equipment main body 3 of a nearly rectangular parallelopiped through a connector 2 made of a material with an excellent heat conductivity. Moreover, a flat shaped heat conductor plate 4 made of a material having a high heat conductive rate made Al or the like is extended while abutting on a connector 2 in the equipment main body 3 and a heat generating body 5 such as a power transistor(TR) is fixed onto the surface of the heat conductor plate 4. When an operation section 6 is operated to set the transmission state, the heat generating body 5 is heated and the heat is transmitted to the connector 2 via the conductor plate 4 and then transmitted to the coaxial cable 1. That is, the heat from the heat generating body 4 transmitted to the connector 2 is radiated in air through a shield section 9 of the coaxial cable 1. The heat generated in the on-vehicle radio equipment is radiated to the outside of the equipment main body 3.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small wireless device such as a vehicle-mounted wireless device or a portable wireless device that has a built-in heating element.

0002

[Prior Art] Conventionally, in this type of small wireless device, a heat dissipation plate attached to the back of the device body or a case of the device body is used as a heat dissipation medium. The heat generated was dissipated.

0003

[Problems to be Solved by the Invention] However, the above-mentioned conventional small wireless device has the following problems. In other words, (1) When installing the heat sink on the back of the device, etc.
It becomes necessary to attach a heat dissipation plate with a large surface area to the back surface, etc., and there is a limit to the ability to reduce the size and weight of the main body of the device. (2) If a heat sink is attached to the back of the device, the small wireless device cannot be installed in a place where heat will accumulate, and if installed in a car etc. subject to restrictions. (3) When using the main body case of the device as a heat dissipation medium,
The main body case is manufactured using metal with high thermal conductivity,
Moreover, since heat dissipation capacity must be ensured, the weight of the device increases. (4) If the main body case is a heat dissipation medium, it will feel hot when you hold it in your hand. (5) Since the main body of the device itself becomes hot, the temperature increase inside the main body has an adverse effect on other devices. There were problems such as.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a compact wireless device that can be further reduced in size and weight without causing a deterioration in quality.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a small wireless device with a built-in heating element, characterized in that a coaxial cable connected to the main body of the device is used as a heat dissipation medium. Further, a heat conductive member is interposed between the heating element and the coaxial cable.

Furthermore, the present invention is characterized in that, in a small wireless device having a built-in heating element, an antenna connected to the main body of the device is used as a heat dissipation medium, and further, there is a space between the heating element and the antenna. It is characterized by the presence of a heat conductive member.

[0007]

[Operation] According to the above structure, the heat generated by the heating element is radiated through the coaxial cable or the antenna.

[0008] Furthermore, heat generated from the heating element is transmitted to the coaxial cable or antenna via the conductive member.

[0009]

[Embodiments] Hereinafter, embodiments of the present invention will be explained in detail based on the drawings.

FIG. 1 is an overall configuration diagram showing an outline of an in-vehicle radio device as an embodiment of a small radio device according to the present invention. The connector 2 is screwed onto a device main body 3 having a substantially rectangular parallelepiped shape via a connector 2 made of a good material. Further, a flat heat conductive plate 4 made of a material with high thermal conductivity such as Al is disposed in the device main body 3 in contact with the connector 2, and a power transistor etc. A heating element 5 is fixedly attached. Reference numeral 6 denotes an operation section for instructing the transmission/reception state, etc., and is provided on the outer surface of the device main body 1 facing the heat conduction plate 4.

Specifically, as shown in FIG. 2, the coaxial cable 1 has a signal line 7 formed in a cylindrical shape and whose outer periphery is made of an insulating member made of resin or the like to provide an electrical insulation effect. A shield portion 9 having a heat dissipation function is formed on the outer periphery of the insulating member 8, and the shield portion 9 is further covered with a covering member 10 made of resin or the like.

In the in-vehicle wireless device configured as described above, as shown in FIG. 1, when the operating section 6 is operated to enter the transmitting state, the heating element 5 built into the device body 3 generates heat. The heat from the heating element 5 is transferred to the connector 2 via the heat conduction plate 4.
The heat transferred to the connector 2 is further transferred to the coaxial cable 1. That is, the heat from the heating element 4 transmitted to the connector 2 is radiated into the air by the shield part 9 of the coaxial cable 1, which has a heat radiating effect (in the figure,
11). In this way, the heat generated within the vehicle-mounted wireless device can be radiated outside the device main body 3.

FIG. 3 is a diagram showing a state in which the above-mentioned in-vehicle wireless device is installed inside an automobile, where 12 is a car in which the in-vehicle wireless device is installed, and 13 is an antenna installed in the automobile 12.

As is clear from this figure, the heat generated in the device body 3 of the in-vehicle radio device is transferred to the coaxial cable 1,
Heat is radiated until it reaches the antenna 13 (in the figure,
14).

[0015] By using the coaxial cable 1 as a heat dissipation medium in this way, it is possible to omit the heat dissipation plate as described in the [Prior Art] section, and it is possible to achieve a reduction in size and weight.

FIG. 4 is a sectional view of another embodiment of a coaxial cable as a heat dissipation medium in a vehicle-mounted wireless device, and the coaxial cable 15 has its covering member removed. In the coaxial cable 1 shown in FIG. 2, the heat dissipation effect in the shield portion 9 is blocked by the sheathing member 10, so there is a risk that a sufficient heat dissipation effect cannot be obtained.However, according to the coaxial cable 15, the sheathing member Since this is removed, it is possible to further improve the heat dissipation effect. In particular, it is expected that the heat dissipation effect will be further enhanced when it comes into contact with metal parts of a car.

FIG. 5 is an overall configuration diagram schematically showing a portable radio device as another embodiment (second embodiment) of the small radio device according to the present invention. A heating element 17 such as a power transistor built in the heat conductive plate 1 is made of a material having high thermal conductivity such as Al.
It is fixed to 8. Further, the heat conductive plate 18 is bent as appropriate to form a recess 19, and the recess 19 is filled with a liquid or solid heat conductive material 20, and the antenna 2
1 is fitted into the thermally conductive material 22. Further, one end of the antenna 21 is connected to a coaxial cable 22 through a small hole provided through the heat conduction plate 18.

FIG. 6 is a diagram showing the state of heat radiation when the portable wireless device is in a transmitting state, with FIG. 6(a) showing the present embodiment and FIG. 6(b) showing the conventional example. Further, in the figure, 23 indicates radio waves transmitted from the antenna 21.

In the conventional example (FIG. 6(b)), the main body case of the device main body 16 was used as a heat sink;
The device main body 16 acts as a heat dissipation medium (indicated by 24 in the figure), and the device main body 16 itself is in a high temperature state. On the other hand, in this embodiment (FIG. 6(a)), heat is radiated into the air using the antenna 21 as a heat radiating medium (
25 in the figure), the device main body 16 itself, and the device main body 1
6. Internal temperature rise can be suppressed to a low level.

FIG. 7 is an overall configuration diagram showing another embodiment of the portable radio device, in which the antenna 21 has good thermal conductivity through a connector 26 that has good thermal conductivity. One end of the joint 27 is in contact with a heat conductive plate 26 having an L-shaped cross section.

Even when the antenna 21 and the device main body 16 are disposed at a considerable distance from each other in this way, as in the first embodiment, the heat generated by the heating element 17 in the device main body 16 is transferred to the heat conductive plate 28 and the joint. 27, the heat is transmitted to the antenna 21 via the connector 26, and the heat can be radiated into the air, thereby achieving the intended purpose.

[0022]

As described in detail above, the present invention provides a small wireless device with a built-in heating element, in which the coaxial cable connected to the device body is used as a heat dissipation medium.
It becomes possible to omit the heat dissipation plate provided on the back side of the device main body, and the device can be made smaller and lighter.

[0023] Furthermore, since the heat generation within the device main body is suppressed to a low level, the degree of freedom in installation is increased when installing the device in a car or the like.

Furthermore, in the present invention, in a small wireless device with a built-in heating element, the antenna connected to the device main body is used as a heat dissipation medium, so that temperature rise inside the device main body can be suppressed to a low level, and It is possible to avoid adverse effects on other devices in the main body of the apparatus, and the sensible temperature is felt to be low even when held by hand, which is convenient when carrying by hand.

Furthermore, in the present invention, since a conductive member is interposed between the heating element and the coaxial cable or antenna, there is no need to conduct heat to the case of the main body of the device as in the conventional case. This eliminates the need to use metals with high thermal conductivity, which helps reduce weight.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment (first embodiment) of a small wireless device according to the present invention.

FIG. 2 is an enlarged sectional view taken along line AA in FIG. 1;

FIG. 3 is a schematic diagram showing a state in which the above-mentioned small wireless device is installed in an automobile.

FIG. 4 is a sectional view showing another example of a coaxial cable.

FIG. 5 is another embodiment of the small wireless device according to the present invention (second embodiment).
FIG.

FIG. 6 is a diagram showing the heat dissipation situation of the second embodiment together with the conventional example.

FIG. 7 is an overall configuration diagram showing still another embodiment of the second embodiment.

[Explanation of symbols]

1 Coaxial cable 2 Connector (thermal conduction member) 4 Heating element 5 Heat conduction plate (heat conduction member) 17 Heating element 18 Heat conduction plate (heat conduction member) 20 Thermal conductive material (thermal conductive member) 21 Antenna 24 Connector (thermal conduction member) 25 Joint (thermal conduction member) 26 Heat conduction plate (heat conduction member)

Claims (4)

[Claims] 1. A small wireless device with a built-in heating element, characterized in that a coaxial cable connected to the device body serves as a heat dissipation medium. 2. The small wireless device according to claim 1, wherein a heat conductive member is interposed between the heating element and the coaxial cable. 3. A small radio device with a built-in heating element, characterized in that an antenna connected to the main body of the device is used as a heat dissipation medium. 4. The small wireless device according to claim 3, wherein a heat conductive member is interposed between the heating element and the antenna.