JP6464984B2 - Electronic equipment - Google Patents

Description

  The present invention relates to an electronic device in which an electrolytic capacitor having an explosion-proof structure is sealed.

  Electrolytic capacitors may generate heat or generate gas during overvoltage, overcurrent, or rapid charge / discharge exceeding the rating. When gas generation occurs, there is a risk of explosion due to an increase in internal pressure. Therefore, many electrolytic capacitors having an explosion-proof structure have been proposed.

  For example, in an electrolytic capacitor having a cylindrical housing, a part of the surface opposite to the side on which the electrodes are provided is thinned. The electrolytic capacitor is an explosion-proof valve that breaks the thin-walled portion when the internal pressure of the housing rises, and part of the housing is turned up toward the outside, allowing the internal gas to escape.

  When an electrolytic capacitor having an explosion-proof valve is mounted on a circuit board or the like, dustproof and waterproof properties are ensured by covering the electrolytic capacitor with a cover or the like. Patent Document 1 discloses a waterproof housing structure in which an electrolytic capacitor is housed in a case. In this waterproof storage structure, a lid for closing the opening of the case is provided so as to form a pressure rise suppression space surrounding the electrolytic capacitor. By forming the pressure suppression space, it is possible to suppress an increase in pressure in the case even if gas is released.

JP 2009-32870 A

  However, since it is necessary to secure a space for the explosion-proof valve to open, it is necessary to provide a clearance between the lid and the casing of the electrolytic capacitor. In addition, since the lid also serves to close the opening of the case, if the opening is wide, the resonance frequency may be lowered due to insufficient flexural rigidity of the lid, and vibration resistance may be impaired. In order to ensure vibration resistance, the lid may be made thicker, but this increases the overall size of the case together with the clearance.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an electronic device having an electrolytic capacitor sealing structure that achieves space saving while achieving both explosion-proof and vibration resistance.

  The invention disclosed herein employs the following technical means to achieve the above object. Note that the reference numerals in parentheses described in the claims and in this section indicate a corresponding relationship with specific means described in the embodiments described later as one aspect, and limit the technical scope of the invention. Not what you want.

  In order to achieve the above object, the present invention provides an electrolytic capacitor (10) having a columnar shape and having an explosion-proof valve on the top surface, and a sealing resin for sealing a part of the electrolytic capacitor so that the top surface is exposed ( 30), a cover (40, 60, 80) fixed to the exposed surface (30a) of the sealing resin and covering the electrolytic capacitor exposed from the sealing resin, and the cover and the sealing resin Connecting portions (50, 70, 90) for carrying out the connection, and the connecting portions extend and contract so that the facing distance between the cover and the top surface of the electrolytic capacitor is variable.

  According to this, even when there is not sufficient clearance between the top surface and the cover, when the explosion-proof valve is opened, the cover can be urged to increase the opposing distance between the top surface and the cover. . Therefore, the generated gas can escape to the outside of the electrolytic capacitor.

  Further, since the cover only needs to cover the periphery of the electrolytic capacitor, the size of the cover can be about the same as the electrolytic capacitor, and the resonance frequency can be made relatively high. For this reason, vibration resistance can be secured without excessively thickening the cover.

It is sectional drawing which shows schematic structure of ISG containing the electronic device which concerns on 1st Embodiment. It is the figure which expanded a part of electronic device, and is sectional drawing which shows the detail of the area | region II in FIG. It is sectional drawing which shows the state which the explosion-proof valve opened. It is sectional drawing of the electronic device which concerns on 2nd Embodiment. It is sectional drawing of the electronic device which concerns on 3rd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same reference numerals are given to the same or equivalent parts.

(First embodiment)
Initially, with reference to FIG. 1 and FIG. 2, schematic structure of the electronic apparatus which concerns on this embodiment is demonstrated.

  The electronic device in the present embodiment is employed in, for example, an ISG (Integrated Starter Generator) that integrates a starter and an alternator. This electronic device is a control unit including an ECU that controls driving of the motor.

  As shown in FIG. 1, the ISG has an electromechanical integrated structure that integrally includes a control unit 100, a motor unit 200, and a pulley 300. The motor unit 200 is mainly composed of a stator and a rotor. The shaft fixed to the rotor rotates following the rotation of the rotor to rotate the pulley 300. A belt contacts the pulley 300, and the rotation of the pulley 300 is transmitted to the internal combustion engine via the belt.

  The control unit 100 includes an electrolytic capacitor 10, a substrate 20, a sealing resin 30, an electronic component 110, a case 120, and an outer lid 130. The electrolytic capacitor 10 and the electronic component 110 are mounted on the substrate 20. The electronic component 110 is an IC chip including a CPU in addition to resistors and capacitors, and the electrolytic capacitor 10, the electronic component 110, and the substrate 20 constitute an ECU. The substrate 20 on which the electrolytic capacitor 10 and the electronic component 110 are mounted is housed in a case 120 and is protected from external force and impact by closing the outer lid 130. Further, the substrate 20 is sealed with a sealing resin 30 together with the electrolytic capacitor 10 and the electronic component 110. Thereby, the electrolytic capacitor 10 and the electronic component 110 are protected from dust and water droplets entering the case.

  FIG. 2 is an enlarged cross-sectional view of the broken line portion shown in FIG. As shown in FIG. 2, a part of the electrolytic capacitor 10 is sealed with the sealing resin 30, but the remaining part is exposed from the sealing resin 30. The electrolytic capacitor 10 in this embodiment is columnar. An electrode (not shown) is provided on the bottom surface 10 a of the electrolytic capacitor 10 and is electrically connected to the substrate 20. On the other hand, an explosion-proof valve is provided on the top surface 10b, and in the unlikely event that the internal pressure of the electrolytic capacitor 10 increases excessively, the explosion-proof valve opens to allow the internal gas to escape. The electrolytic capacitor 10 is sealed with a sealing resin 30 so that the top surface 10b side is exposed. Thus, the explosion-proof valve can be opened without being obstructed by the sealing resin 30 in the unlikely event.

  As shown in FIG. 2, the control unit 100 as an electronic device includes a cover 40 and a connection unit 50.

  The cover 40 has a truncated cone shape and is formed so as to cover the electrolytic capacitor 10 exposed from the sealing resin 30. The upper bottom portion 40 a of the truncated cone is in contact with the top surface 10 b of the electrolytic capacitor 10. Any material may be selected for the cover 40, but a galvanized copper plate may be employed. A corrosion-resistant metal material is preferable. Further, the edge portion 40 b located at the lower bottom portion of the truncated cone is fixed to the exposed surface 30 a of the sealing resin 30 through the connection portion 50. The connection part 50 is, for example, a silicone-based adhesive and has elasticity. That is, the adhesive material serving as the connection portion 50 can be elastically deformed, and the cover 40 moves up and down in the axial direction of the electrolytic capacitor 10 along with the deformation. The upper bottom portion 40a of the cover 40 is in contact with the top surface 10b of the electrolytic capacitor 10 in a state where the adhesive as the connecting portion 50 is in a natural length. Then, the cover 40 and the top surface 10b are separated from each other in a state where the connecting portion 50 extends beyond the natural length.

  In addition, the connection part 50 in this embodiment is formed over the perimeter of the edge part 40b of the cover 40, and the space enclosed by the cover 40 and the sealing resin 30 is sealed space isolated from the external space. It has become.

  Next, with reference to FIG. 3, the effect of the electronic apparatus which concerns on this embodiment is demonstrated.

  The cover 40 is fixed to the sealing resin 30 via the connection portion 50 and covers the electrolytic capacitor 10. And since the connection part 50 has a stretching property in the axial direction of the electrolytic capacitor 10, the cover 40 can be displaced in the axial direction.

  In the cover 40 of this embodiment, the upper bottom portion 40 a is in contact with the top surface 10 b of the electrolytic capacitor 10. When the explosion-proof valve formed on the top surface 10b of the electrolytic capacitor 10 is opened, the explosion-proof valve biases the upper bottom portion 40a. At this time, since the cover 40 can be displaced in the axial direction, the displacement of the explosion-proof valve is not hindered. In other words, the gas released from the electrolytic capacitor 10 can be released into the expanded space between the electrolytic capacitor 10 and the cover 40, and unintentional breakage of the electrolytic capacitor 10 can be prevented.

  Moreover, since the top 40a of the cover 40 of this embodiment has contact | abutted to the top | upper surface 10b of the electrolytic capacitor 10 after exhibiting the said effect, the top | bottom surface 10b of the cover 40 and the top | upper surface 10b of the electrolytic capacitor 10 are contacted. The clearance between the two can be substantially eliminated. According to this, the physique in the axial direction of the electrolytic capacitor 10 can be reduced.

  Further, since the cover 40 is formed so as to cover the electrolytic capacitor 10, the upper bottom portion 40 a needs to be larger than the diameter of the electrolytic capacitor 10, but the entire opening of the case 120 is closed as in the conventional case. There is no need to secure the size. That is, the cover 40 for protecting the electrolytic capacitor 10 can be made smaller than a conventional lid. For this reason, the resonant frequency in the upper bottom part 40a can be enlarged, and vibration resistance can be improved.

  Further, in the cover 40 in the present embodiment, the space surrounded by the cover 40, the connection portion 50, and the sealing resin 30 is isolated from the external space. For this reason, it is possible to prevent the entry of corrosive liquids containing dust, moisture, especially salt, from the outside, and the corrosion reliability of the electrolytic capacitor 10 can be improved.

  As described above, by adopting this electronic device, it is possible to realize space saving while achieving both explosion-proof property and vibration resistance.

(Second Embodiment)
In the first embodiment, an example in which the substantially truncated cone cover 40 covers the electrolytic capacitor 10 is illustrated. On the other hand, the cover 60 of this embodiment is a flat plate member. As shown in FIG. 4, the edge 60 a of the cover 60 is connected to the connecting portion 70. The connection portion 70 in the present embodiment is a tube material whose side surface has a bellows shape, and is a so-called bellows-type telescopic tube. One end of the connecting portion 70 is closed by a cover 60, and the other end is embedded and fixed in one surface 30 a of the sealing resin 30. Also in this embodiment, the cover 60 can employ a corrosion-resistant metal. The cover 60 and the connection part 70 can be integrally molded.

  The cover 60 is in contact with the top surface 10b of the electrolytic capacitor 10 when the bellows shape of the connecting portion 70 is a natural length. When the explosion-proof valve formed on the top surface 10 b of the electrolytic capacitor 10 is opened, the explosion-proof valve biases the cover 60. At this time, since the cover 60 can be displaced in the axial direction by being deformed in the direction in which the bellows of the connecting portion 70 extends, the displacement of the explosion-proof valve is not hindered. In other words, the gas released from the electrolytic capacitor 10 can be released into the expanded space between the electrolytic capacitor 10 and the cover 60, and unintentional breakage of the electrolytic capacitor 10 can be prevented. In addition, the same effects as those of the first embodiment can be obtained.

  In addition, since the components other than the cover 60 and the connection portion 70 are the same as those in the first embodiment, detailed description thereof is omitted.

(Third embodiment)
The connection portion 50 in the first embodiment is an adhesive, and the connection portion 70 in the second embodiment is a bellows-shaped tube member, whereas the connection portion 90 in the present embodiment is a low elastic modulus tube member.

  The cover 80 in this embodiment is a substantially flat plate member as in the second embodiment, and as shown in FIG. The connecting portion 90 is a tube material having a lower elastic modulus than the cover 80 and the sealing resin 30. One end of the connecting portion 90 is connected to a fixing portion 80a in the cover 80 and fixed integrally therewith. The other end of the connecting portion 90 is embedded and fixed in one surface 30 a of the sealing resin 30. The cover 60 in this embodiment can employ a corrosion-resistant metal. Moreover, the connection part 90 can employ | adopt a silicone type rubber material.

  The cover 80 is in contact with the top surface 10b of the electrolytic capacitor 10 when the connecting portion 90 has a natural length. When the explosion-proof valve formed on the top surface 10 b of the electrolytic capacitor 10 is opened, the explosion-proof valve biases the cover 80. At this time, the cover 80 can be displaced in the axial direction by being deformed in the direction in which the connecting portion 90 extends, so that the displacement of the explosion-proof valve is not hindered. That is, the gas released from the electrolytic capacitor 10 can be released into the expanded space between the electrolytic capacitor 10 and the cover 80, and the unintended damage of the electrolytic capacitor 10 can be prevented. In addition, the same effects as those of the first embodiment can be obtained.

  In addition, since the components other than the cover 80 and the connection portion 90 are the same as those in the first embodiment, detailed description thereof is omitted.

(Other embodiments)
The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  In each of the above-described embodiments, the example in which the covers 40, 60, and 80 are in contact with the top surface 10b of the electrolytic capacitor 10 has been described. However, they are not necessarily in contact with each other, and a predetermined clearance may be provided.

  Further, in each of the above-described embodiments, the example in which the constituent material of the covers 40, 60, 80 is a galvanized copper plate has been described. However, it is not necessarily limited to a galvanized copper plate. Moreover, the constituent material of the connection parts 50, 70, 90 is not limited. However, it is preferable that the constituent materials of the covers 40, 60, 80 and the connection portions 50, 70, 90 have corrosion resistance.

  Further, in each of the above-described embodiments, the example in which the space surrounded by the covers 40, 60, 80 and the connection portions 50, 70, 90 and the sealing resin 30 is isolated from the external space has been described. According to this, it is possible to prevent moisture and dust that cause corrosion from the outside from reaching the electrolytic capacitor 10. However, for example, the connection portions 50, 70, and 90 may be formed only in a part around the electrolytic capacitor 10 so that the space around the electrolytic capacitor 10 communicates with the external space.

  In each of the above-described embodiments, an example in which the control unit 100 that is an electronic device is used for ISG has been described. However, this is an example, and the electrolytic capacitor 10 including the explosion-proof valve is sealed and protected. If it is an aspect, the present invention can be applied.

  Further, in each of the above-described embodiments, the form in which the electrolytic capacitor is mounted on the substrate 20 has been described, but the present invention is not limited to this example. For example, you may electrically connect to the bus-bar wiring inserted in the resin case.

DESCRIPTION OF SYMBOLS 10 ... Electrolytic capacitor, 20 ... Board | substrate, 30 ... Sealing resin, 40 ... Cover, 50 ... Connection part

Claims (7)

An electrolytic capacitor (10) having a column shape and having an explosion-proof valve on the top surface;
Sealing resin (30) for sealing a part of the electrolytic capacitor so that the top surface is exposed;
A cover (40, 60, 80) fixed to the exposed surface (30a) of the sealing resin and formed to cover the electrolytic capacitor exposed from the sealing resin;
A connection part (50, 70, 90) for connecting the cover and the sealing resin;
The connection device is an electronic device that expands and contracts so that a facing distance between the cover and the top surface of the electrolytic capacitor is variable.   The electronic device according to claim 1, wherein the space surrounded by the cover, the connection portion, and the sealing resin is a sealed space isolated from an external space.   The electronic device according to claim 1, wherein the cover abuts against a top surface (10 b) of the electrolytic capacitor when the connection portion has a natural length.   The electronic device according to claim 1, wherein the connection portion is an adhesive having elasticity in at least the axial direction of the electrolytic capacitor.   The electronic device according to claim 1, wherein a part of the connection portion is embedded and fixed in the sealing resin.   The electronic device according to claim 5, wherein the connection portion has a bellows shape at a portion exposed from the sealing resin, and the bellows shape expands and contracts.   The electronic device according to claim 5, wherein the connection portion has a portion exposed from the sealing resin having a lower elastic modulus than the cover and the sealing resin.

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