JP2005019791A - Power controlling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power controlling device having superior air tightness by solving the problem that security cannot be secured under an environment using a combustible gas since the power controlling device is not airtight. <P>SOLUTION: A component mounting board 7 is accommodated in a case body 8; and a sealing resin 11 and sealant are used in the gap of a hole section 8a from which a lead wire is pulled out and the gap between the case body 8 and a case cover 10, respectively, thus achieving a closed structure of the device and hence the power controlling device can be used at ease even under the environment of the combustible gas. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power control device such as an inverter or a switching power supply for driving a motor at a variable speed.
[0002]
[Prior art]
In recent years, with the progress of power electronics, power control devices have been used in all fields. For example, an inverter is used for the purpose of energy saving in a refrigerator or an air conditioner, and induction overheating is also used in a rice cooker or the like.
[0003]
As a conventional power control device, there is one in which miniaturization has been improved particularly in consideration of heat dissipation in the power element (see, for example, Patent Document 1).
[0004]
The conventional power control apparatus will be described below with reference to the drawings.
[0005]
FIG. 7 is a cross-sectional view of a conventional power control apparatus. As shown in FIG. 7, the power converter 101 is attached to a large radiator 102, and the first substrate 103 is fixed to the radiator 102 by a first spacer 104. The first substrate 103 is electrically connected to the power converter 101, and is mounted with a smoothing capacitor 105, a voltage regulator 106 that generates a control power source, and the like.
[0006]
Control components such as a microcomputer (not shown) are mainly mounted on the second substrate 107, and are fixed to the first substrate 103 by a second spacer 108. The cover 109 is attached so as to cover these circuits.
[0007]
The operation of the conventional power control apparatus configured as described above will be described below.
[0008]
The power converter 101 is cooled by transmitting the heat from the power converter 101, which is a component that generates a large amount of heat, to the radiator 102 to dissipate the heat.
[0009]
[Patent Document 1]
JP-A-9-28383 gazette
[Problems to be solved by the invention]
However, in the conventional configuration, the radiator 102 and the cover 109 are simply assembled, and there is a gap between them. In addition, although a connection with the outside is necessary, there is no description of a specific method for connecting a lead wire or the like, and its practicality is lacking. Therefore, in this configuration, the hermeticity is not sufficient, and for example, in an environment where a flammable gas such as propane or isobutane is used, there is a drawback that safety cannot be ensured when gas enters the apparatus.
[0011]
SUMMARY OF THE INVENTION The present invention solves the conventional problem, in which a sealing resin is bonded to a hole for drawing a lead wire from a side surface of a case body, and a sealing agent is bonded to a gap between the case body and the case cover without any gap. Thus, an object of the present invention is to provide a power control device that can improve airtightness.
[0012]
Another object of the present invention is to separate the power line and the signal line by pulling out the AC high voltage lead wire from the first hole of the case body and the DC low voltage lead wire from the second hole on the opposite side. It is possible to provide a power control device that can reduce malfunction caused by noise or the like.
[0013]
Another object of the present invention is to form the case cover with a resin portion having a constant outer periphery and a shape in which a metal plate portion is insert-molded at the opening portion of the resin portion, and one surface of the radiator and the metal plate portion of the case lid, By using a high thermal conductivity material during this period, it is an object of the present invention to provide a power control device that can sufficiently dissipate heat from a heat-generating component while ensuring airtightness.
[0014]
Another object of the present invention is to miniaturize the component mounting board by minimizing the insulation distance and the spatial distance by injecting an insulating potting material with a constant thickness into the bottom surface of the case body on which the component mounting board is mounted. It is providing the power control apparatus which can do.
[0015]
[Means for Solving the Problems]
The invention according to claim 1 of the present invention includes a substrate on which a component is mounted, a heat generating component mounted on the substrate, a radiator attached so as to be in thermal contact with the heat generating component, and the substrate. A component mounting board constituted by a mounted electronic component and a lead wire electrically connected to the outside; and at least one hole portion for accommodating the component mounting board and drawing out at least the lead wire. A case main body, a sealing resin that seals a gap between the lead wire and the case main body hole, a case cover that covers an opening of the case main body, and a seal that seals a gap between the case main body and the case cover Since the sealing resin is bonded to the hole where the lead wire is pulled out from the side surface of the case body, and the sealing agent is bonded to the gap between the case body and the case cover, without any gaps, Has the effect of air-tightness can be achieved parts and equipment inside and apparatus completely blocked.
[0016]
According to a second aspect of the present invention, in the first aspect of the present invention, a second hole portion is provided on the opposite side of the first hole portion of the case body, the AC high-pressure lead wire from the first hole portion, and the second hole portion. Each of the DC low-voltage lead wires is drawn out, and the AC high-voltage lead wire and the DC low-voltage lead wire can be completely separated from each other, thereby reducing the influence of noise applied between the lead wires.
[0017]
The invention according to claim 3 is the invention according to any one of claims 1 to 2, wherein the case cover is a resin portion having a constant outer periphery, and a metal plate portion is inserted into an opening portion of the resin portion. It is configured in a molded shape and is thermally bonded between one side of the radiator and the metal plate of the case cover. Since the case cover itself is insert-molded, the metal plate part and the resin part are sufficiently airtight. In addition, the case main body and the case cover can be reliably bonded with the sealant. Moreover, since the heat generated by the radiator is thermally conducted to the case lid, it has the effect of suppressing the temperature rise inside the case.
[0018]
According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, an insulating potting material is injected at a constant thickness into the bottom surface of the case body on which the component mounting board is mounted. By covering the component mounting board with an insulating potting material with excellent electrical insulation performance, it is possible to minimize the insulation distance of the board pattern and the spatial distance between parts, and to reduce the size of the device. .
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a power control apparatus according to the present invention will be described below with reference to the drawings.
[0020]
(Embodiment 1)
FIG. 1 is a cross-sectional view of a power control apparatus according to Embodiment 1 of the present invention.
[0021]
In FIG. 1, reference numeral 1 denotes a substrate on which a control circuit including an electronic component 2, a semi-heating component 3, a microcomputer (not shown), and the like is mounted. The semi-heat generating component 3 here refers to a voltage regulator or the like for stabilizing the control power supply.
[0022]
Reference numeral 4 denotes a heat generating component, which is generally a power element that performs a main operation in a power control apparatus, and a MOSFET, an IGBT, or the like is used. Further, as a heat generating component, a rectifying diode or the like is one of these components. The heat generating component 4 is mounted on the substrate 1.
[0023]
Reference numeral 5 denotes a radiator, which is in sufficient thermal contact with the heat generating component 4, and serves to diffuse and dissipate heat generated by the heat generating component 4. Reference numeral 6 denotes a lead wire used for power supply and signal exchange with the outside, and a connector is used for the substrate 1 or is directly connected and fixed electrically.
[0024]
The component mounting board 7 is configured as described above.
[0025]
Reference numeral 8 denotes a resin case body, and the component mounting board 7 is fixed to the bottom surface with a spacer 9 and accommodated inside. There is a hole 8a on the side surface of the case body 8, from which the lead wire 6 is drawn out. A gap between the hole 8a and the lead wire 6 is filled with a sealing resin 11 to ensure internal airtightness. Here, as the sealing resin 11, by using a hot melt agent such as polypropylene or polyamide, the case body and the lead wire 6 are covered with resin, so that sufficient adhesion can be obtained instantaneously. .
[0026]
A resin case cover 10 is attached to the opening of the case main body 8 and seals the gap between the case main body 8 and the case cover 10 with a sealant 12. Here, as the sealing agent 12, by using a hot melt agent such as polypropylene or polyamide, sufficient adhesiveness and sealing properties can be obtained instantaneously.
[0027]
FIG. 2 is a circuit diagram of an example of the power control apparatus according to Embodiment 1 of the present invention. Here, an inverter that drives a motor at a variable speed will be described as an example of a power control device.
[0028]
In FIG. 2, 13 is a commercial power source, and 100V50Hz or 60Hz is generally used in a general household in Japan.
[0029]
A converter 14 converts the AC voltage of the commercial power supply 13 into a DC voltage. The converter 14 bridges the four rectifier diodes 15 a to 15 d to perform full-wave rectification of the commercial power supply 13. The electrolytic capacitor 16 is connected to the positive voltage output and the negative voltage output of the bridge-connected rectifier diodes 15a to 15d, and smoothes the full-wave rectified voltage to obtain a DC voltage.
[0030]
Reference numeral 17 denotes an inverter, which converts the DC voltage output of the converter 14 into a three-phase AC having an arbitrary frequency and an arbitrary voltage. In the inverter 17, IGBTs 18a to 18f are connected in a three-phase bridge, and high speed diodes 18g to 18l are connected in parallel to the IGBTs 18a to 18f. The high speed diodes 18g to 18l function to flow a reflux current when the IGBTs 18a to 18f are turned off.
[0031]
A motor 19 is driven by the three-phase AC output of the inverter 17. The motor 19 rotates at a rotation speed corresponding to the output frequency of the inverter 17.
[0032]
A control circuit 20 generates a waveform for driving the inverter 17 using a microcomputer or the like, or detects an abnormal operation of the inverter 17 (a detection circuit is not shown) to perform a protection operation or the like.
[0033]
Reference numeral 21 denotes a power supply circuit which receives the DC output of the converter 14 and outputs a power supply (for example, 5 V) for operating the control circuit 20. Here, the power supply circuit 21 uses a switching power supply, and a MOSFET 22a, a switching transformer 22b, a diode 22c, a capacitor 22d, a voltage regulator 22e, and the like are used.
[0034]
Here, a more detailed description will be added by comparing FIG. 2 and FIG.
[0035]
The heat generating component 4 in FIG. 1 is the rectifier diodes 15a to 15d, IGBTs 17a to 17f, and high speed diodes 17g to 17l in FIG. 2, and is particularly an element through which the electric power for driving the motor 19 passes. All of these heat generating components are mounted on the substrate 1.
[0036]
1 is the MOSFET 22a, the diode 22c, the voltage regulator 22e, and the like in FIG. 2, and the power is only the power for driving the control circuit 20. Therefore, the loss is not as great as that of the heat generating component. However, it is mounted on the substrate 1 with a component whose temperature rise is large if it is not radiated well.
[0037]
The electronic component 2 in FIG. 1 is a control circuit 20 including a microcomputer in FIG. 2, a drive circuit (not shown) for driving the IGBTs 17a to 17f, and the like, and is similarly mounted on the substrate 1.
[0038]
Further, the lead wire 6 in FIG. 1 is for connecting the commercial power source 13 and the converter 14 in FIG. 2 and for connecting the inverter 17 and the motor 19, respectively, and for exchanging signals between the outside and the control circuit 20. Mounted on the substrate 1.
[0039]
The power control device configured as described above will be described in more detail.
[0040]
Since the heat generating component 4 is an element that handles main power for power control, the heat generating component 4 has a very large loss and generates a large amount of heat. For example, when obtaining an output of 500 W, a loss of 25 W occurs even if the conversion efficiency is 95%. Such a large loss generates heat and raises the temperature in the case. At this time, if the combustible gas enters the case and the gas is sufficiently warmed and the power control device ignites due to an external cause, combustion may occur.
[0041]
However, in the present invention, all the gaps are sealed by the sealing resin 11 and the sealing agent 12 to improve the airtightness of the case.
[0042]
By doing in this way, invasion of the combustible gas into the case can be prevented.
[0043]
As described above, in the power control device according to the present embodiment, the sealing resin 11 is provided in the gap between the hole 8 a of the case body 8 and the lead wire 6, and the sealing agent 12 is provided in the gap between the case body 8 and the case cover 10. Since each device is used as a completely sealed type, safety can be ensured even in an environment where flammable gas is used. In addition, since it has a sufficient sealing property against gas, high reliability can be exhibited even in a high humidity environment.
[0044]
(Embodiment 2)
FIG. 3 is a cross-sectional view of a power control apparatus according to Embodiment 2 of the present invention.
[0045]
3, the same components as those of the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.
[0046]
In the present embodiment, a second hole portion 8b is provided on the opposite side of the first hole portion 8a of the case body 8 in the first embodiment, and the AC high voltage lead wire 6a of the lead wire 6 is connected to the DC hole from the first hole portion 8a. The low pressure lead wire 6b is pulled out from the second hole 8b. In addition, the 2nd hole part 8b is filled with the sealing resin 11 similarly to the 1st hole part 8a, and the inside airtightness is ensured.
[0047]
By doing so, the AC high voltage lead 6a used as a power supply line that is a source of noise generation and noise intrusion is completely separated from the DC low voltage lead 6b used as a signal line for controlling other devices. can do.
[0048]
As described above, the power control device of the present embodiment separates the lead wire 6 into the AC high voltage side and the DC low voltage side and draws it to the outside, so that the influence of noise from the power supply can be transmitted to the signal side. This can reduce the occurrence of malfunction of the apparatus.
[0049]
(Embodiment 3)
FIG. 4 is a sectional view of a power control apparatus according to Embodiment 3 of the present invention. FIG. 5 is a perspective view of a case cover of the power control apparatus according to the third embodiment.
[0050]
4 and 5, the same reference numerals are given to the same configurations as those in the first and second embodiments shown in FIGS. 1 to 3, and detailed descriptions thereof are omitted.
[0051]
In the present embodiment, the case cover 10 according to the first and second embodiments has an insert molding configuration in which the outer periphery of the metal plate portion 10a is sandwiched between resin portions 10b having a certain width as shown in FIG. The case cover 10 is attached to the opening of the case body 8, and the gap between the resin portion 10 a of the case cover 10 and the case body 8 is sealed with a sealant 12.
[0052]
Further, in the present embodiment, the shape of the radiator 5 is an L-shaped radiator 5 a that is L-shaped, and the upper surface of the L-shaped radiator 5 a and the metal plate portion 10 b of the case cover 10 are thermally coupled. Here, a high thermal conductivity material 23 is used as a material to be thermally coupled. As the specific high heat conductive material 23, non-flowable silicone resin, elastic heat conductive sheet and the like are preferable.
[0053]
By doing in this way, the heat generated from the heat generating component 4 is transferred from the L-type radiator 5a to the highly heat-conductive material 23, and the case, while ensuring sufficient airtightness between the case body 8 and the case cover 10. The heat is conducted to the cover metal plate portion 10a, and further radiated to the outside of the case.
[0054]
As described above, in the power control device of the present embodiment, the case cover resin portion 10b ensures airtightness with the case main body 8, and the case cover metal plate portion 10a and the L-shaped radiator 5a are connected to the high thermal conductivity material 23. In this case, the temperature rise in the case can be reduced, and the safety in a combustible gas environment can be further improved. In addition, since the high thermal conductivity material 23 is used, uneven heat conduction due to surface roughness and assembly variations of the L-type radiator 5a and the case cover metal plate portion 10a can be eliminated, and highly efficient heat radiation can be performed.
[0055]
(Embodiment 4)
FIG. 6 is a sectional view of a power control apparatus according to Embodiment 4 of the present invention.
[0056]
In FIG. 6, the same components as those in the first to third embodiments shown in FIGS. 1 to 5 are denoted by the same reference numerals, and detailed description thereof is omitted.
[0057]
In the present embodiment, the insulating potting material 24 is exposed on the bottom surface of the case main body 8 on which the component mounting board 7 in the first to third embodiments is mounted (a mounting component on the component mounting board 7 is exposed). It is injected and hardened at such a height that the electrically charged metal part is hidden. Here, the insulating potting material 24 is preferably an epoxy, urethane, or silicone resin having a dielectric breakdown strength of 18 kV / mm or more.
[0058]
As described above, the power control apparatus according to the present embodiment injects the insulating potting material 24 directly into the case main body 8 and pots the component mounting board 7 without using a dedicated jig or the like. It is possible to work, minimizing the insulation distance and the spatial distance at the time of designing the component mounting board 7, and the apparatus can be miniaturized.
[0059]
【The invention's effect】
As described above, the invention described in claim 1 includes a board on which a component is mounted, a heat generating component mounted on the board, a radiator attached to be in thermal contact with the heat generating component, A component mounting board composed of an electronic component mounted on the board and a lead wire electrically connected to the outside; and at least one hole for accommodating the component mounting board and pulling out at least the lead wire A case body having a portion, a sealing resin that seals a gap between the lead wire and the case body hole, a case cover that covers an opening of the case body, and a gap between the case body and the case cover is sealed By providing the sealing agent, the device can be made completely sealed, and even if used in a flammable gas environment, there is an effect that an explosion-proof specification structure can be made excellent in safety.
[0060]
Moreover, in addition to the invention of Claim 1, the invention of Claim 2 provides the 2nd hole part in the facing of the 1st hole part of a case main body, AC lead wire for AC high voltage | pressure from the 1st hole part, By pulling out the DC low-voltage lead wires from the second hole portions, it is possible to reduce the influence of noise from the power supply line to the signal line, and to reduce the occurrence of malfunction.
[0061]
In addition to the inventions described in claims 1 and 2, the invention described in claim 3 is an insert molding of the case cover with a resin portion having a constant outer periphery and a metal plate portion at an opening portion of the resin portion. The heat rise between one side of the radiator and the metal plate of the case cover can suppress the temperature rise inside the case while ensuring a completely sealed type of equipment, and is explosion-proof. There is an effect that further safety of the structure can be improved.
[0062]
In addition to the inventions described in claims 1 to 3, the invention described in claim 4 injects an insulating potting material with a certain thickness into the bottom surface of the case body on which the component mounting board is mounted. As a result, it is possible to minimize the design of the component mounting board, and it is possible to reduce the size of the entire apparatus.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a power control apparatus according to Embodiment 1 of the present invention. FIG. 2 is a circuit diagram of an example of a power control apparatus according to Embodiment 1. FIG. 3 is a power control according to Embodiment 2 of the present invention. FIG. 4 is a cross-sectional view of a power control apparatus according to Embodiment 3 of the present invention. FIG. 5 is a perspective view of a case cover of the power control apparatus according to Embodiment 3. FIG. Sectional view of power control apparatus according to embodiment 4 [FIG. 7] Cross-sectional view of conventional power control apparatus [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Board | substrate 2 Electronic component 3 Semi-heating component 4 Heat generating component 5 Radiator 5a L-type radiator 6 Lead wire 6a AC high voltage lead wire 6b DC low voltage lead wire 7 Component mounting substrate 8 Case main body 8a First hole 8b Second Hole 10 Case cover 10a Case cover metal plate 10b Case cover resin 11 Sealing resin 12 Sealing agent 23 High thermal conductivity material 24 Insulating potting material

Claims (4)

A substrate on which the component is mounted; a heat generating component mounted on the substrate; a radiator attached so as to be in thermal contact with the heat generating component; an electronic component also mounted on the substrate; A component mounting board composed of a lead wire to be connected; a case main body that houses the component mounting board and has at least one hole for drawing out the lead wire; and the lead wire and the case main body A power control comprising: a sealing resin that seals a gap between the holes; a case cover that covers the opening of the case body; and a sealant that seals the gap between the case body and the case cover. apparatus. A second hole portion is provided on the opposite side of the first hole portion of the case body, and an AC high voltage lead wire is drawn out from the first hole portion, and a DC low voltage lead wire is drawn out from the second hole portion, respectively. The power control apparatus according to claim 1. The case cover is formed of a resin portion having a constant outer periphery, and a metal plate portion is formed by insert molding at an opening portion of the resin portion, and heat is applied between one surface of the radiator and the metal plate portion of the case cover. The power control device according to claim 1, wherein the power control device is combined. 4. The power control device according to claim 1, wherein an insulating potting material is injected with a constant thickness into the bottom surface of the case body on which the component mounting board is mounted. 5.

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