JP2010034400A - Electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To normally operate an explosion-proof valve while preventing moisture or dust from contacting an electrolytic capacitor, in an electronic apparatus having structure where a circuit board with an electrolytic capacitor having an explosion-proof valve mounted thereon is arranged in a case, and a resin is filled in the case. <P>SOLUTION: In this electronic apparatus 1, a through-hole 23 making the internal region of a case 7 communicate with the outside is formed on the case 7 to face the other end face 5b of the electrolytic capacitor 5 with the explosion-proof valve formed thereon; a bottomed tubular cap 31 closing the through-hole 23 is attached thereto; and the cap 31 includes a thin-plate-like easily-rupturable wall part 32 arranged opposite to the explosion-proof valve, a tubular circumferential wall part 33 erected on an edge in the surface direction of the easily-rupturable wall part 32 and arranged opposite to the circumferential surface of the electrolytic capacitor 5, and an elastic holding part 34 embedding a space between the circumferential wall part 33 and the circumferential surface of the electrolytic capacitor 5 over the circumferential direction. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronic device including an electrolytic capacitor having an explosion-proof valve.

Conventionally, in an electronic device such as an inverter power supply device, as in Patent Document 1, for example, an electrolytic capacitor is housed in a case in a state where it is mounted on a mounting surface of a circuit board together with other electronic components, and the case is filled with resin. And there is a hermetically sealed one.
The electrolytic capacitor provided in this electronic device has improved airtightness so that the internal electrolyte does not leak, but overvoltage or reverse voltage is applied to the electrolytic capacitor for some reason, or the electrolytic capacitor is subjected to severe charge / discharge conditions. If the battery is used at a higher temperature than allowable, the internal pressure of the electrolytic capacitor may increase. For this reason, an explosion-proof valve is formed on the outer surface of the electrolytic capacitor, and the explosion-proof valve is ruptured before the internal pressure of the electrolytic capacitor rises excessively. That is, when the electrolytic capacitor includes the explosion-proof valve, it is necessary to secure a space for bursting the explosion-proof valve on the outer surface side of the electrolytic capacitor so that the explosion-proof valve operates normally.

Therefore, as shown in FIG. 5, some of the conventional electronic devices have an explosion-proof valve exposed to the outside of the case 101 through a window portion 102 formed in the case 101. In this configuration, the electrolytic capacitor 103 is disposed so that the peripheral edge of the explosion-proof valve of the electrolytic capacitor 103 is in close contact with the inner surface of the case 101 located at the peripheral edge of the window portion 102, and the inside of the case 101 is resin-sealed. .
In addition, as shown in FIG. 6, the above-mentioned conventional electronic device includes a chimney 105 formed in a cylindrical shape and covered on an explosion-proof valve. In this configuration, the chimney 105 is mounted on the electrolytic capacitor 103 and disposed in the case 101, and the resin 101 is filled in the case 101 with the opening portion of the chimney 105 exposed, so that the electrolytic capacitor 103 and the chimney 105 are filled. 105 is sealed.
JP-A-8-154377

However, in the above-described conventional electronic device, when the periphery of the explosion-proof valve is disposed in close contact with the inner surface of the case 101 located at the periphery of the window portion 102, the resin 107 is filled when the resin 107 is filled in the case 101. High accuracy is required for the relative positioning of the window 102 and the explosion-proof valve so that the resin 107 does not leak from the window 102 to the outside of the case 101. For this reason, there exists a problem that positioning of the electrolytic capacitor 103 with respect to the window part 102 of case 101 becomes troublesome.
In addition, in the configuration in which the cylindrical chimney 105 is placed on the explosion-proof valve, care should be taken so that the resin 107 does not enter the chimney 105 from the opening of the chimney 105 when the resin 107 is filled. There is a possibility that the filling of 107 becomes troublesome.
Furthermore, it is desirable that moisture and dust do not contact the electrolytic capacitor 103. However, in the above-described conventional electronic device, the explosion-proof valve is exposed to the outer space of the case 101 through the window portion 102, or chimney. Since the opening portion 105 is exposed to the outside of the case 101 and the filled resin 107, there is a possibility that moisture and dust may reach the electrolytic capacitor 103.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide an electronic device that can normally operate an explosion-proof valve while preventing moisture and dust from contacting an electrolytic capacitor. To do.

  In order to solve this problem, an electronic apparatus according to the present invention is an electronic apparatus having a configuration in which a circuit board on which an electrolytic capacitor having an explosion-proof valve is mounted is accommodated in a case, and the resin is filled in the case. The case is formed with a through-hole that communicates the inner region of the case outwardly so as to face the explosion-proof valve, and the bottomed cylinder that closes the through-hole by being inserted into the through-hole. A cap is attached, and the cap is a thin plate-like easy-to-break wall portion disposed opposite to the explosion-proof valve, and is provided on the periphery in the surface direction of the easily-breakable wall portion to face the outer peripheral surface of the electrolytic capacitor A cylindrical peripheral wall portion to be disposed, and an elastic holding portion that fills a gap between the peripheral wall portion and the outer peripheral surface of the electrolytic capacitor in the circumferential direction are provided.

  When manufacturing the electronic apparatus according to the present invention, the through hole of the case can be easily closed only by inserting the cap into the through hole of the case. Accordingly, it is possible to easily prevent the case from leaking outward from the through hole of the case when the case is filled with resin. For example, just insert the cap into the through-hole of the case with the cap attached to the electrolytic capacitor so as to cover the explosion-proof valve, or simply attach the electrolytic capacitor to the cap after attaching the cap to the through-hole of the case. In addition, the electrolytic capacitor can be easily positioned with respect to the through hole of the case.

  Furthermore, when manufacturing the electronic device, when the circuit board on which the electrolytic capacitor is mounted is filled in the case with the circuit board being accommodated in the case, the circuit board and the electrolytic capacitor are covered with a cap. The part that is not sealed is sealed with resin. On the other hand, the outer peripheral surface covered with the cap and the explosion-proof valve of the electrolytic capacitor are not sealed with resin. This is because the gap between the peripheral wall portion of the cap and the outer peripheral surface of the electrolytic capacitor is blocked by the elastic holding portion, thereby preventing the resin from entering the gap.

And in the electronic device manufactured as mentioned above, since the electrolytic capacitor is sealed with respect to the outer space of the electronic device by the cap, it can prevent reliably that a water | moisture content and dust contact an electrolytic capacitor.
In this electronic apparatus, when the internal pressure of the electrolytic capacitor is excessively increased, the explosion-proof valve can be normally operated. Here, the easily breakable wall portion of the cap is disposed opposite to the explosion-proof valve. Since the easily breakable wall portion is formed in a thin plate shape and easily breaks when the explosion-proof valve bursts, the explosion-proof valve Can be operated normally.

  And in the said electronic device, an uneven | corrugated shape is formed in at least one of the outer peripheral surface of the said cap, and the internal peripheral surface of the said through-hole, and the fitting part which fits the said cap to the said through-hole is comprised by the said uneven | corrugated shape. In this case, it is possible to reliably close the through hole with the cap.

In the electronic device, the case may be formed with a cylindrical wall portion that protrudes outward and into which the electrolytic capacitor is inserted, and the through-hole is configured by the cylindrical wall portion.
In this case, it is possible to reduce the volume of the electronic device by reducing the volume in the case in which the circuit board and the electrolytic capacitor are accommodated. That is, various electronic components are mounted on the circuit board (mounting surface thereof) in addition to the electrolytic capacitor, and the height dimension of these electronic components is often lower than the height dimension of the electrolytic capacitor. Therefore, by forming a cylindrical wall portion for the electrolytic capacitor in the case, it is possible to prevent an extra space from being formed in the case, and thus it is possible to reduce the size of the electronic device as described above. .

Furthermore, in the electronic device, the elastic holding portion may be configured by an annular inward protrusion that protrudes inward in the radial direction of the peripheral wall from the inner peripheral surface of the peripheral wall. The portion may be tapered toward the protruding direction.
In these cases, since the area where the elastic holding portion abuts on the outer peripheral surface of the electrolytic capacitor can be reduced, the cap can be attached to the electrolytic capacitor with a small force.

  In the electronic device, the easily breakable wall portion, the peripheral wall portion, and the elastic holding portion constituting the cap may be integrally formed of an elastic material that can be elastically deformed.

According to the present invention, the through hole of the case can be easily closed by the cap, and the electrolytic capacitor can be easily positioned with respect to the case. In addition, when filling the case with resin, the explosion-proof valve can be prevented from being sealed with the resin even if care is not required, and thus the electronic device can be easily manufactured.
Further, the explosion-proof valve can be normally operated when the internal pressure of the electrolytic capacitor is excessively increased while reliably preventing moisture and dust from coming into contact with the electrolytic capacitor.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the electronic apparatus 1 according to this embodiment includes two circuit boards 2 and 3, a columnar electrolytic capacitor 5 mounted on the first circuit board 2, and these two circuit boards. 2 and 3 and a case 7 for accommodating the electrolytic capacitor 5, and a resin 9 filled in the case 7 in which the circuit boards 2 and 3 and the electrolytic capacitor 5 are accommodated.
The electrolytic capacitor 5 is, for example, an existing aluminum electrolytic capacitor, and an electrode 11 for electrical connection with the first circuit board 2 is formed on one end surface 5a, and an explosion-proof valve (not shown) is formed on the other end surface 5b. Configured.

The case 7 includes a connector portion 13 having a plurality of terminals 12 electrically connected to the electrolytic capacitor 5, and a housing portion 15 that houses the two circuit boards 2 and 3 and the electrolytic capacitor 5.
The accommodating part 15 is formed in the box shape which has the opening part 15a opened to the thickness direction. The second circuit board 3 is disposed on the bottom surface 16 a of the housing portion 15, and the first circuit board 2 is disposed above the bottom surface 16 a of the housing portion 15 with a space therebetween. And the area | region where the electrolytic capacitor 5 is not mounted is opposed to the 2nd circuit board 3 among the mounting surfaces 2a of the 1st circuit board 2. FIG. The first circuit board 2 is electrically connected to the terminals 12 of the connector portion 13 via the first connector 17, the second circuit board 3 and the second connector 18.

  Further, the case 7 is formed with a cylindrical tubular wall portion 21 that protrudes outward from the bottom wall portion 16 of the housing portion 15 that forms the bottom surface 16a. A through hole 23 is formed to communicate the region outward. In a state where the first circuit board 2 is housed in the case 7, the electrolytic capacitor 5 mounted on the first circuit board 2 is inserted into the cylindrical wall portion 21. In this inserted state, the other end surface 5 b of the electrolytic capacitor 5 is disposed to face the outer opening 23 a of the through hole 23 located at the tip of the cylindrical wall portion 21 in the protruding direction.

A bottomed cylindrical cap 31 that closes the through hole 23 by being inserted into the through hole 23 of the cylindrical wall portion 21 is attached to the case 7 configured as described above.
As shown in FIG. 3, the cap 31 is made of a thin plate-like easily breakable wall portion 32 and an easily breakable wall portion, which are opposed to the other end surface 5b of the electrolytic capacitor 5 by an elastically deformable elastic material such as rubber. The cylindrical peripheral wall portion 33 standing on the peripheral edge of the surface direction 32 and disposed opposite to the outer peripheral surface of the electrolytic capacitor 5 and the elasticity that fills the gap between the peripheral wall portion 33 and the outer peripheral surface of the electrolytic capacitor 5 in the circumferential direction. The holding part 34 is formed integrally.
The easily breakable wall portion 32 is disposed in the outer opening 23a of the through hole 23 in a state where the cap 31 is attached to the case 7, and the thickness dimension and shape of the easily breakable wall portion 32 are determined when the explosion-proof valve is ruptured. The strength is set so as to easily break.

  And the uneven | corrugated shape in alignment with the standing direction of the surrounding wall part 33 is formed in the outer peripheral surface of the cap 31 from the easily breakable wall part 32 to the surrounding wall part 33, The cyclic | annular recessed part 35 recessed in radial direction inner side by this uneven | corrugated shape. Is configured. The annular recess 35 is formed in an annular shape over the circumferential direction of the outer peripheral surface of the peripheral wall 33. On the other hand, as shown in FIGS. 1 and 4, the inner circumferential surface of the through hole 23 located in the outer opening 23 a of the through hole 23 is formed with an uneven shape along the protruding direction of the cylindrical wall portion 21. Due to the uneven shape, an annular protrusion 25 is formed that protrudes radially inward from the inner peripheral surface of the through hole 23. The annular protrusion 25 is formed along the circumferential direction of the inner peripheral surface of the through hole 23.

The annular protrusion 25 of the cylindrical wall 21 is fitted into the annular recess 35 of the cap 31 described above, whereby the cap 31 is fixed to the case 7 and the outer opening 23a of the through hole 23 is closed by the cap 31. The That is, the annular recess 35 of the cap 31 and the annular protrusion 25 of the case 7 constitute a fitting portion 37 for fitting the cap 31 into the through hole 23. In this embodiment, since the entire cap 31 is made of an elastic material, the annular protrusion 25 of the cylindrical wall portion 21 is easily formed in the annular recess 35 of the cap 31 while the cap 31 is elastically deformed. In addition, the cap 31 can reliably close the through hole 23.
Further, in the state where the cap 31 is fixed to the case 7, the annular recess 35 is located on the proximal end side in the standing direction of the peripheral wall portion 33, and the peripheral wall portion 33 is raised more than the formation position of the annular recess 35. A gap is formed between the outer peripheral surface of the peripheral wall 33 located on the front end side in the installation direction and the inner peripheral surface of the through hole 23.

The elastic holding portion 34 is configured by an annular inward projection 39 that protrudes inward in the radial direction of the peripheral wall portion 33 from the inner peripheral surface of the peripheral wall portion 33. The inward projecting portion 39 is formed between the distal end and the proximal end of the peripheral wall portion 33 on the inner peripheral surface of the peripheral wall portion 33, and is tapered toward the protruding direction.
As shown in FIGS. 1 and 2, the inner diameter dimension of the inward projection 39 is smaller than the outer diameter dimension of the electrolytic capacitor 5. That is, the inward protruding portion 39 has an electrolytic capacitor facing the inner peripheral surface of the peripheral wall portion 33 in a state where the end portion on the other end surface 5b side of the electrolytic capacitor 5 is inserted into the cap 31 so as to cover the explosion-proof valve. 5 constitutes a closing means for filling the gap with the outer peripheral surface of 5.

In the state where the end portion of the electrolytic capacitor 5 is inserted into the cap 31, as shown in FIG. 4, the peripheral wall located on the distal end side with respect to the inward projection portion 39 and on the proximal end side with respect to the inward projection portion 39. A gap is formed between the inner peripheral surface of the portion 33 and the outer peripheral surface of the electrolytic capacitor.
In the illustrated example, when the electrolytic capacitor 5 mounted on the first circuit board 2 is inserted into the cap 31 fixed to the case 7, the other end surface 5b of the electrolytic capacitor 5 and the easily breakable wall portion of the cap 31 are used. A gap is also formed between the cap 32 and the other end surface 5b of the electrolytic capacitor 5 may be in contact with the easily breakable wall portion 32 of the cap 31, for example.

As shown in FIGS. 1 and 4, the resin 9 includes the two circuit boards 2 and 3, the electrolytic capacitor 5, and the two connectors 17 and 18 in the case 7 as described above, and the cap 31 is formed in the case. 7, the container 15 is filled, and the two circuit boards 2 and 3 and the two connectors 17 and 18 are sealed.
In addition, the resin 9 seals only a portion of the electrolytic capacitor 5 that is not covered by the cap 31, and a portion covered by the cap 31 is not sealed by the resin. In the present embodiment, the portion covered by the cap 31 indicates a portion of the electrolytic capacitor 5 on the side of the other end surface 5b with respect to the portion that is in contact with the inward projection 39.
Further, the resin 9 is formed so that the clearance between the inner peripheral surface of the peripheral wall portion 33 and the outer peripheral surface of the electrolytic capacitor 5 located on the front end side with respect to the inward projecting portion 39 and the standing position of the peripheral wall portion 33 with respect to the formation position of the annular recess 35. A gap between the outer peripheral surface of the peripheral wall 33 located on the front end side in the installation direction and the inner peripheral surface of the through hole 23 is also filled.

Next, a method for manufacturing the electronic apparatus 1 configured as described above will be described.
When manufacturing the electronic apparatus 1, first, the electrolytic capacitor 5 is mounted on the first circuit board 2, and the cap 31 is attached to the case 7.
Next, the second circuit board 3 is placed on the bottom surface 16 a of the housing part 15, and then the first circuit board 2 on which the electrolytic capacitor 5 is mounted is housed in the housing part 15. In this accommodation, the electrolytic capacitor 5 is inserted into the cylindrical wall portion 21, and the end portion on the other end surface 5 b side of the electrolytic capacitor 5 is further inserted into the cap 31. At this time, for example, the tapered inward projection 39 is elastically deformed so as to bend in the insertion direction of the electrolytic capacitor 5, and the tip of the inward projection 39 is brought into contact with the outer peripheral surface of the electrolytic capacitor 5 by this elastic force. Pressed. That is, the gap between the inner peripheral surface of the peripheral wall portion 33 and the outer peripheral surface of the electrolytic capacitor 5 facing the inner projecting portion 39 is filled.

  As described above, by inserting the electrolytic capacitor 5 mounted on the first circuit board 2 into the cap 31 attached to the case 7, the end of the electrolytic capacitor 5 can be easily inserted into the cap 31. it can. That is, even if the mounting position of the electrolytic capacitor 5 with respect to the first circuit board 2 is displaced, the displacement can be eliminated by elastic deformation of the cap 31 during insertion. That is, the electrolytic capacitor 5 can be easily positioned with respect to the through hole 23 of the case 7.

After the accommodation of the first circuit board 2 is completed, the first circuit board 2 and the second circuit board 3 are electrically connected by the first connector 17 and the second circuit board 3 and the connector are connected by the second connector 18. The terminal 12 of the unit 13 is electrically connected. Finally, the molten resin 9 is poured into the accommodating portion 15 from the opening 15a side, and the resin 9 is cured, whereby the manufacture of the electronic device 1 is completed.
In this resin filling, the first circuit board 2 is disposed so as to cover most of the opening 15a of the accommodating portion 15, but the first circuit board 2 has a thickness direction as shown in FIG. Since an opening 2b penetrating through the first circuit board 2 is formed, and a gap is formed between the peripheral edge of the mounting surface 2a of the first circuit board 2 and the side wall of the housing portion 15, the resin 9 is added to the first circuit board 2. And the bottom wall portion 16 of the case 7 or into the cylindrical wall portion 21 can be smoothly guided.

Further, since the outer opening 23a of the through hole 23 is closed by the cap 31, the resin 9 guided into the cylindrical wall portion 21 can easily leak out of the case 7 from the outer opening 23a. Can be prevented.
Further, as shown in FIG. 4, since the gap between the inner peripheral surface of the peripheral wall portion 33 and the outer peripheral surface of the electrolytic capacitor 5 is filled with the inward protruding portion 39, the resin 9 introduced into the cylindrical wall portion 21. Can also be prevented from entering the gap. That is, the resin 9 does not enter the gap between the electrolytic capacitor 5 and the cap 31 located on the other end surface 5 b side of the electrolytic capacitor 5 with respect to the contact portion between the electrolytic capacitor 5 and the inward projection 39.

  The resin 9 introduced into the cylindrical wall portion 21 has a gap between the inner peripheral surface of the peripheral wall portion 33 and the outer peripheral surface of the electrolytic capacitor 5 positioned on the tip side of the inward projecting portion 39, and the annular concave portion 35. The gap between the outer peripheral surface of the peripheral wall portion 33 and the inner peripheral surface of the through hole 23 that is located on the distal end side in the standing direction of the peripheral wall portion 33 with respect to the formation position is filled. Thereby, since the peripheral wall part 33 located in the front end side rather than the inward protrusion part 39 is inserted | pinched by the resin 9 from both the inner side and the outer side, the cap 31 can be firmly fixed to the resin 9.

As described above, according to the electronic device 1 according to the above embodiment, the cap 31 can easily close the through hole 23 of the case 7, and the electrolytic capacitor 5 can be easily positioned with respect to the case 7. In addition, when filling the case 9 with the resin 9, the explosion-proof valve can be prevented from being sealed with the resin 9 without requiring caution, so that the electronic device 1 can be easily manufactured. .
Further, according to the electronic device 1, since the electrolytic capacitor 5 is sealed with respect to the outer space of the electronic device 1 by the cap 31, it is possible to reliably prevent moisture and dust from coming into contact with the electrolytic capacitor 5. In the electronic device 1, when the internal pressure of the electrolytic capacitor 5 rises excessively, the explosion-proof valve can be operated normally. Here, the easily breakable wall portion 32 of the cap 31 is disposed opposite to the explosion-proof valve. However, the easily breakable wall portion 32 is formed in a thin plate shape so that it easily breaks when the explosion-proof valve bursts. The explosion-proof valve can be operated normally.

Furthermore, the cylindrical wall portion 21 into which the electrolytic capacitor 5 is inserted is formed in the case 7, thereby reducing the volume in the case 7 in which the first circuit board 2 and the electrolytic capacitor 5 are accommodated, thereby reducing the size of the electronic device 1. Can be achieved. That is, in addition to the electrolytic capacitor 5, various electronic components may be mounted on the mounting surface 2 a of the first circuit board 2. The height dimensions of these electronic components are compared with the height dimension of the electrolytic capacitor 5. Often low. Therefore, by forming the cylindrical wall portion 21 for the electrolytic capacitor 5 in the case 7, it is possible to prevent an extra space from being formed in the case 7, so that the electronic device 1 can be downsized as described above. Can be achieved.
In addition, since the elastic holding portion 34 is configured by the tapered inward projection portion 39, the area of the elastic holding portion 34 that contacts the outer peripheral surface of the electrolytic capacitor 5 can be reduced. It can be attached to the electrolytic capacitor 5.

As mentioned above, although the electronic device 1 which is embodiment of this invention was demonstrated, the technical scope of this invention is not limited to this, It can change suitably in the range which does not deviate from the technical idea of this invention.
For example, the electronic apparatus 1 includes the two circuit boards 2 and 3, but may include the first circuit board 2 on which at least the electrolytic capacitor 5 is mounted. In this case, what is necessary is just to connect the 1st circuit board 2 and the terminal 12 of the connector part 13 only with a connector.
Further, the cylindrical wall portion 21 and the cap 31 of the case 7 are formed in a cylindrical shape, but the present invention is not limited to this, and it is sufficient that the cylindrical wall portion 21 and the cap 31 are formed in a cylindrical shape corresponding to at least the shape of the electrolytic capacitor 5.

Furthermore, although the inward projection 39 is formed between the distal end and the proximal end of the peripheral wall 33, the resin does not enter at least the gap between the other end surface 5b of the electrolytic capacitor 5 and the easily breakable wall 32. What is necessary is just to be formed. Therefore, the inward projection 39 may be formed at the distal end of the peripheral wall 33, for example, or may be formed at the proximal end of the peripheral wall 33.
In addition, the circumferential wall portion 33 of the cap 31 is formed with an annular inward projection 39 that protrudes inward in the radial direction of the circumferential wall portion 33 from the inner circumferential surface, but at least the outer circumference of the circumferential wall portion 33 and the electrolytic capacitor 5 The elastic holding part 34 which fills up the clearance gap between the surfaces over the circumferential direction should just be formed. Therefore, the elastic holding portion 34 may be formed on the entire inner peripheral surface of the peripheral wall portion 33, for example, the entire peripheral wall portion 33 may be pressed against the outer peripheral surface of the electrolytic capacitor 5.

Further, the annular protrusion 25 is formed in the outer opening 23a of the through hole 23. However, the present invention is not limited to this. For example, the annular protrusion 25 may be formed closer to the first circuit board 2 than the outer opening 23a. Good. In this case, the easily breakable wall portion 32 of the cap 31 is also positioned closer to the first circuit board 2 than the outer opening 23a.
Further, although the fitting portion 37 for fitting the cap 31 into the through hole 23 is configured by the annular recess 35 of the cap 31 and the annular protrusion 25 of the through hole 23, the outer peripheral surface of the cap 31 and the through hole 23. What is necessary is just to be comprised by the uneven | corrugated shape formed in at least one of the internal peripheral surface of this. For example, the fitting portion includes an annular protrusion that protrudes radially outward from the outer peripheral surface of the cap 31, and an annular recess that is recessed radially outward from the inner peripheral surface of the through hole 23 and fits into the protrusion. It may be constituted by. The protrusion can be formed by forming an uneven shape on the outer peripheral surface of the cap 31, and the concave portion of the through hole 23 can be formed by forming an uneven shape on the inner peripheral surface of the through hole 23. .

Furthermore, the cylindrical wall portion 21 into which the electrolytic capacitor 5 is inserted is formed in the case 7, but the internal region of the case 7 is communicated outward at least at a position facing the explosion-proof valve of the electrolytic capacitor 5. The through-hole 23 should just be formed. That is, if the thickness dimension of the accommodating portion 15 of the case 7 is set to such an extent that the electrolytic capacitor 5 mounted on the first circuit board 2 can be accommodated, for example, of the electrolytic capacitor 5 in the bottom wall portion 16 of the case 7. A through hole may be formed at a position facing the other end surface 5b.
When the case 7 does not have the cylindrical wall portion 21 as described above, for example, an annular recess 35 similar to that in the above embodiment is formed in the cap 31, and the annular recess 35 is formed at the bottom of the through-hole periphery. What is necessary is just to make it fit in the wall part 16. FIG. In this case, a fitting portion for fitting the cap 31 into the through hole can be configured only by the uneven shape formed on the outer peripheral surface of the cap 31.

Further, the cap 31 is configured by integrally forming the easily breakable wall portion 32, the peripheral wall portion 33, and the elastic holding portion 34 with an elastic material. However, at least the elastic holding portion 34 is formed so as to be elastically deformable. The easily breakable wall portion 32 and the peripheral wall portion 33 may be formed of other resin materials, for example.
Further, when the electronic device 1 is manufactured in the above embodiment, the electrolytic capacitor 5 mounted on the first circuit board 2 is inserted into the cap 31 attached to the case 7. After being inserted into the cap 31, the cap 31 may be inserted into the through hole 23. For example, after the electrolytic capacitor 5 mounted on the first circuit board 2 is attached to the case 7, the cap 31 is attached to the case 7. The electrolytic capacitor 5 may be inserted into the cap 31. Even in these cases, the electrolytic capacitor 5 can be easily positioned with respect to the through hole 23 of the case 7 as in the above embodiment.

It is a schematic sectional drawing which shows the electronic device which is one Embodiment of this invention. In the electronic device of FIG. 1, it is a schematic sectional drawing which shows the state before filling with resin. It is an expanded sectional view which shows the cap with which the electronic device of FIG. 1 is equipped. In the electronic device of FIG. 1, it is a principal part expanded sectional view which shows the structure of the outer side opening part vicinity of a through-hole. It is a schematic sectional drawing which shows an example of the conventional electronic device. It is a schematic sectional drawing which shows the other example of the conventional electronic device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electronic device 2 1st circuit board 5 Electrolytic capacitor 5b Other end surface 7 Case 9 Resin 21 Cylindrical wall part 23 Through-hole 31 Cap 32 Easy-to-break wall part 33 Peripheral wall part 34 Elastic holding part 37 Fitting part 39 Inward protrusion part

Claims (6)

An electronic device having a configuration in which a circuit board on which an electrolytic capacitor having an explosion-proof valve is mounted is accommodated in a case, and resin is filled in the case.
The case is formed with a through-hole that communicates the inner region of the case outward so as to face the explosion-proof valve, and has a bottomed cylindrical shape that closes the through-hole by being inserted into the through-hole. The cap is attached,
The cap is a thin plate-shaped easily breakable wall portion disposed opposite to the explosion-proof valve, and a cylindrical peripheral wall that is erected on the peripheral edge in the surface direction of the easily breakable wall portion and is disposed opposite to the outer peripheral surface of the electrolytic capacitor. And an elastic holding portion that fills a gap between the peripheral wall portion and the outer peripheral surface of the electrolytic capacitor in the circumferential direction.   An uneven shape is formed on at least one of an outer peripheral surface of the cap and an inner peripheral surface of the through hole, and a fitting portion for fitting the cap into the through hole is configured by the uneven shape. Item 2. The electronic device according to Item 1.   3. The case according to claim 1, wherein the case is formed with a cylindrical wall portion that protrudes outward and into which the electrolytic capacitor is inserted, and the through-hole is formed by the cylindrical wall portion. The electronic device as described in.   The said elastic holding part is comprised by the cyclic | annular inward protrusion part which protrudes in the radial inside of the said surrounding wall part from the internal peripheral surface of the said surrounding wall part, The any one of Claims 1-3 characterized by the above-mentioned. The electronic device as described in.   The electronic device according to claim 4, wherein the inward protrusion is tapered toward the protruding direction.   The easily breakable wall portion, the peripheral wall portion, and the elastic holding portion constituting the cap are integrally formed of an elastic material that can be elastically deformed. The electronic device as described in the paragraph.

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