JPH06260777A - Electronic control device for electric apparatus - Google Patents

Abstract

PURPOSE:To improve heat resistant and fire proof property, to eliminate a problem of radio waves interference and also to improve heat radiation property. CONSTITUTION:A metal case 1 is formed, a circuit board 4 mounting electronic parts 2... is accommodated within the metal case 1 keeping the distance from the circumferencial wall of the case 1 through spacers 5, 5 made of an electric insulating material and the potting resin is injected thereto to wrap such electronic parts 2.... Moreover, parts which generate a large amount of heat among such electronic parts 2... is provided in contact with the metal case 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic control device for electric equipment used in a washing machine or the like.

[0002]

2. Description of the Related Art Conventionally, in an electric device such as a washing machine, a circuit board on which control electronic components are mounted is housed in a case made of synthetic resin, and a potting resin is used to wrap the electronic component in the case. Is injected to form an electronic control unit.

[0003]

However, according to the above-mentioned prior art, when any one of the electronic parts fails and generates heat or ignites, the synthetic resin case receives the heat and melts or burns. There was a problem that In addition, the case made of synthetic resin cannot prevent the electronic components from interfering with or interfere with the peripheral equipment, and further, even when the electronic components normally generate heat. However, there is a problem that the internal temperature is raised and the life of the control device is shortened.

In addition, among electronic parts, there are parts that generate a large amount of heat such as a power transistor and a diode bridge, but another large heat dissipation plate is required to promote heat dissipation of the parts, and the control device Has become larger and the cost has risen.

The present invention has been made in view of the above circumstances, and therefore an object thereof is electronic control of an electric device which is excellent in heat resistance and fire resistance, has no problem of radio interference, and has excellent heat dissipation. To provide the equipment.

[0006]

In order to achieve the above object, an electronic control device for electric equipment according to the present invention comprises a metal case, and a circuit board having electronic parts mounted on the metal case. Is housed so as to be separated from the peripheral wall of the case via a spacer made of an electrically insulating material, and potting resin is injected so as to wrap the electronic component. In that case, it is advisable to provide the electronic component, which generates a large amount of heat, in contact with the case.

[0007]

According to the above means, even if one of the electronic parts fails and generates heat or fires, the metal case does not withstand the melting and combustion. Further, the metal case has a shield function of blocking radio interference from peripheral equipment or radio interference from peripheral equipment. Further, the metal case also has a function of radiating heat against the normal heat generation of electronic components. Since the circuit board is housed in the metal case so as to be separated from the peripheral wall of the case via a spacer made of an electric insulating material, necessary electric insulation can be ensured and the potting resin You can get around easily.

[0008] In addition, in the electronic component provided with a large heat generating component in contact with the metal case, the case also functions as a heat radiating component of the large heat generating component.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. First, in FIGS. 1 to 3,
1 shows a case 1 made of a metal such as aluminum or iron, which has a rectangular box shape with an open top surface. In the case 1, a circuit board 4 including a rectangular printed wiring board on which necessary electronic components 2 ...
It is stored via spacers 5 and 5.

The spacers 5 and 5 are made of an electrically insulating material, such as plastic, and are elongated as shown in FIG. 4. Grooves 6 and 6 are formed on the inner surfaces of the spacers 5 and 5, and the outer surfaces and the bottom surface thereof are formed. Recesses 7, 7 and 8, 8 are formed on the side. Thus, the circuit board 4 has grooves 6 and 6 of the spacers 5 and 5.
Insert both short sides into the
It is stored in case 1 together with 5. As a result, the circuit board 4 is spaced from the peripheral wall of the case 1, especially the short side wall, by the depth g1 corresponding to the depth of the recesses 7 and 7, and from the bottom wall by the dimension g2 corresponding to the depth of the recesses 8 and 8. There is.

Further, a potting resin 9 is injected into the case 1 to a depth that wraps the electronic components 2 ... And exposes the connection surface of the connector 3. The potting resin 9 is made of urethane rubber, for example, and is in a liquid state at the time of injection, but it is solidified after the injection so that the electronic component 2
It has the function of preventing deterioration of ... due to moisture and outside air, or preventing damage due to impact.

According to the above structure, even if any of the electronic components 2 ...
Since is made of metal, it withstands it and does not melt or burn. The metal case 1 has a shield function of blocking electromagnetic interference from peripheral devices or electromagnetic interference from peripheral devices. Furthermore, metal case 1
Has a function of radiating the normal heat generated by the electronic components 2, ... Therefore, the internal temperature is not excessively raised, and the life of the control device can be extended.

Since the circuit board 4 is housed in the metal case 1 so as to be separated from the peripheral wall of the case 1 via the spacers 5 made of an electrically insulating material, the necessary electrical insulation is obtained. And the potting resin 9
The wraparound can also be improved by the gap of the dimensions g1 and g2.

In contrast to the above, FIGS. 5 and 6 show a second embodiment of the present invention, in which a large amount of heat is generated in the electronic component such as a power transistor or a diode bridge 2 '.
Shows a case in which the case 1 is brought into contact with the case 1 and fixed by screws and nuts (not shown). By doing so, the case 1 also functions as a heat radiating component of the component 2'which generates a large amount of heat, Since it is not necessary to use another large heat dissipation plate, it is possible to suppress an increase in size of the control device and an increase in cost.

In this case, the spacers 11 ... Are present at the four corners of the circuit board 4, and with respect to the circuit board 4,
On the side wall of the case 1, there are formed inwardly projecting projections 12 at a plurality of locations, whereby the circuit board 4 is fixed by pressing and the component 2'which generates a large amount of heat is screwed. The rattling of 4 is prevented.

Besides, the present invention is not limited to the embodiments described above and shown in the drawings, and can be implemented with appropriate modifications within the scope not departing from the gist.

[0017]

The electronic control device for electric equipment of the present invention is as described above, and has the following effects. First
In, a metal case is provided, and in this metal case, the circuit board on which electronic components are mounted is housed so as to be separated from the peripheral wall of the case via a spacer made of an electrically insulating material,
By injecting the potting resin so as to enclose the electronic component, heat resistance and fire resistance can be improved, and there is no problem of radio interference, and heat dissipation can be further improved.

Secondly, since the large heat-generating component of the electronic component is provided in contact with the metal case, the large heat-radiating component can be radiated without the need for a large radiator plate. As a result, it is possible to suppress the increase in size of the control device and the increase in cost.

[Brief description of drawings]

FIG. 1 is a plan view of the entire apparatus showing a first embodiment of the present invention.

FIG. 2 is a vertical sectional view taken along the line AA of FIG.

FIG. 3 is a vertical sectional view taken along the line BB.

FIG. 4 is a perspective view of only a spacer.

FIG. 5 is a vertical sectional view of the entire apparatus showing a second embodiment of the present invention.

FIG. 6 is a partially enlarged vertical sectional view.

[Explanation of symbols]

1 is a case, 2 is an electronic component, 4 is a circuit board, 5 is a spacer, 9 is potting resin, 2'is a component that generates a large amount of heat,
Reference numeral 11 indicates a spacer.

Claims (2)

[Claims] 1. A metal case, a circuit board in which an electronic component is mounted and is housed in the case so as to be separated from a peripheral wall of the case via a spacer made of an electrically insulating material, and the electronic component in the case. And a potting resin which is injected so as to wrap it. 2. The electronic control device for an electric device according to claim 1, wherein a part of the electronic part that generates a large amount of heat is provided in contact with the case.