JP7221761B2 - case mold type capacitor - Google Patents

Description

The present invention relates to a case-molded capacitor in which a capacitor unit with busbars drawn out is housed in an exterior case and molded with resin.

In a case mold type capacitor, one end (base side) of a bus bar for external connection is connected to a pair of positive and negative electrodes of a capacitor element, and most of the capacitor element and bus bar are housed in an exterior case. One ends of the capacitor element and the bus bar are embedded in the molded resin filled and solidified in the exterior case, and the other ends are pulled out from the molded resin to form external connection terminal portions. The overlapping portions of the pair of busbars (rising plate portions raised from the base embedded in the mold resin toward the outside of the molding resin) are arranged close to each other, and between the overlapping portions of the pair of busbars. An insulating plate is inserted and interposed (see Patent Document 1).

Japanese Patent Application Laid-Open No. 2010-251400 (Patent No. 5391797)

Conventionally, in case mold type capacitors configured as described above, there has been a problem that external connection terminal portions of a pair of positive and negative bus bars are broken or broken due to stress due to vibration loads in vibration tests and actual use. When we investigated the cause, we found that the external connection terminals were made of a conductive metal such as a copper plate and formed into thin plate tongues with a small width. It was thought that

The inventors of the present invention have found that this problem is not caused only by the fact that the external connection terminal portion is shaped like a tongue of thin thin plate, but that the following circumstances lie in the background.

That is, when the exterior case is filled with the molten resin that is the source of the molding resin, the molten resin is sucked up by capillary action in the minute gap between the pair of bus bars and the insulating plate. The sucked-up molten resin hardens to form a resin fixing portion, which strongly fixes the bus bar to the insulating plate. Originally, the external connection terminal part has the function of absorbing and relaxing the vibration load due to its flexibility (easiness of elastic deformation). This may lead to breakage or breakage of the external connection terminals.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a case mold type capacitor capable of preventing external connection terminal portions from being broken or broken due to vibration loads.

The present invention solves the above problems by taking the following measures.

A case-molded capacitor according to the present invention comprises:
a capacitor element;
an exterior case having an opening and housing the capacitor element;
a pair of bus bars having one end connected to a pair of positive and negative electrodes of the capacitor element and having an external connection terminal portion provided at the other end and arranged close to each other;
an insulating member inserted between the pair of bus bars;
A case mold type capacitor comprising: a mold resin filled in the outer case and embedding one end of the capacitor element and the pair of bus bars,
In a region where the bus bar is embedded in the mold resin, the bus bar and the insulating member face each other with a minute gap therebetween,
In at least a part of the area where the bus bar is exposed from the mold resin, a gap expansion portion is formed to limit the sucking up of the molten resin due to capillary action in the micro gap by expanding the gap dimension of the micro gap. It is characterized by

According to the above configuration of the present invention, the following effects are exhibited.

External connection terminals are susceptible to stress caused by vibration loads during vibration tests and actual use of case mold type capacitors. In particular, when the arm length of the external connection terminal portion is short, the influence of the stress due to the vibration load is large, and the external connection terminal portion may break or break. Here, the "arm length" is the length dimension of the movable range of the external connection terminal portion due to vibration. More specifically, the mechanical and electrical connection portion of the external connection terminal portion connected to the external terminal is used as the fastening portion, and the fixing portion is formed by fixing the bus bar and the insulating member by suction resin based on capillary action. is the resin-fixed portion, and the length from the fastening portion to the resin-fixed portion corresponds to the "arm length".

According to the present invention, the minute gap formed between the bus bar and the insulating member is formed as a gap expanded portion by expanding the size of the gap, thereby limiting the sucking up of the molten resin due to capillary action. It is configured as follows. Specifically, a gap expanding portion for limiting resin suction is formed in at least a part of the region where the bus bar is exposed from the mold resin.

The pair of positive and negative external connection terminal portions are spaced apart from each other due to the fastening relationship with the cable connection terminal from the external electrical equipment. That is, they are arranged so as not to overlap in the direction perpendicular to the plate surface. Therefore, even if there is overlap with the insulating member in the vicinity of the root portion of the external connection terminal portion connected to the rising plate portion, there is no overlap with the insulating member on the free end side (closer to the fastening portion) of the external connection terminal portion. . At least a part of the area where the busbar is exposed from the mold resin is formed with a gap expansion part, and this gap expansion part restricts the absorption of molten resin by capillary action, thereby keeping the resin-adhered part away from the fastening part. . As a result, the length of the arm of the external connection terminal becomes longer, and the influence of the vibration load can be mitigated to prevent breakage or breakage of the external connection terminal.

The case mold type capacitor of the present invention having the above configuration has the following preferred aspects and variations/modifications.

[1] There is a mode that the gap expanding portion is formed in at least one of the pair of micro gaps formed between the pair of bus bars and the insulating member.

The minute gaps include a minute gap between the external connection terminal portion of the positive electrode and the insulating member and a minute gap between the external connection terminal portion of the negative electrode and the insulating member. Due to the resin-adhered portion formed by sucking up the molten resin due to capillary action in the minute gap, the external connection terminal portion may break or break due to the stress caused by the vibration load. It may be both of the terminal portions, or may be only one of them.

Depending on the specifications of the case mold type capacitor, etc., it is sufficient to form a gap expansion portion for the bus bar that requires prevention of breakage and breakage due to stress due to vibration load. That is, the gap expanding portion may be formed in the positive electrode side minute gap of both bus bars, may be formed in the negative electrode side minute gap, or may be formed in both of them. good.

[2] There is a mode in which the gap expanding portion is formed as a concave portion that is concave in the thickness direction of the insulating member.

There are two methods for forming the gap expansion part: the insulating member and the busbar, which are a pair of members facing each other with a small gap in between; It is conceivable to use a method of forming the gap expansion portion by devising in , or a combination of both methods.

In the insulating member, by forming a recess recessed in the thickness direction on the plate surface portion on the side requiring the gap expansion portion, the gap expansion portion can be easily formed without modifying the bus bar. The gap expanding portion formed by forming such a concave portion may be formed on either one of the two side plate surfaces of the insulating member, or may be formed on both plate surfaces.

[3] Further, there is a mode in which the gap widening portion as the recessed portion is formed over a width region of the insulating member protruding outward from both side edges in the width direction of the external connection terminal portion.

In the case of forming the gap expanding portion as the recessed portion in the insulating member, the forming region of the recessed portion may be within the range of the area occupied by the external connection terminal portion. Due to the fact that the entrance part is sealed by the external connection terminal part and the volume of the recessed part is limited to a small size, the molten resin that has entered due to the capillary phenomenon in the minute gap is sucked up into the recessed part (gap There may remain the possibility that the action of clipping inside the extension may be compromised.

On the other hand, if recessed portions (gap widened portions) are formed over the width regions that protrude outward from both side edges in the width direction of the external connection terminal portion, the above effect can be favorably exhibited, and the resin fixing portion can be removed. It is possible to increase the length of the arm of the external connection terminal portion by moving it away from the fastening portion, thereby ensuring the effect of preventing breakage and breakage of the external connection terminal portion.

[4] Further, there is a mode in which the gap expanding portion is formed by separating a part of the facing surface of the bus bar facing the insulating member from the insulating member.

If the recessed portion is formed in the insulating member, there is a possibility that the effective thickness of the insulation is reduced and the insulation between the pair of positive and negative bus bars is deteriorated.

On the other hand, by separating a part of the facing surface of the bus bar facing the insulating member from the insulating member, the gap widened portion can be formed without changing the thickness of the insulating member.

[5] In addition, the pair of busbars may have different arm lengths of the external connection terminal portions, and the gap may be formed between the busbar having the shorter arm length of the external connection terminal portion and the insulating member. In one aspect, an extension is formed.

For a pair of busbars with different arm lengths for the external connection terminals, there is a busbar that may break or break due to stress caused by vibration load, and a busbar that does not break or break. may exist. In such a case, it is possible to prevent breakage and breakage by forming gap widening portions in the busbars having short arm lengths of the external connection terminal portions.

[6] In addition, there is a mode in which the bus bar is fixed to the exterior case via the mold resin in a state in which it does not contact the exterior case.

If the busbar were to come into contact with the exterior case, the micro gap formed between the exterior case and the busbar would cause molten resin to be sucked up due to capillary action, and the external connection terminals would break due to the stress caused by the vibration load.・Risk of breakage increases.

On the other hand, such a risk can be avoided by fixing the bus bar to the exterior case via the mold resin in a state where the bus bar does not come into contact with the exterior case as described in this section.

According to the present invention, since the gap widened portion is formed in the area where the bus bar is exposed from the mold resin, the sucking up of the molten resin due to the capillary action in the minute gap is restricted, thereby alleviating the vibration load and thus the bus bar. Breakage and breakage can be prevented.

1 is a see-through perspective view showing the structure of a case mold type capacitor (excluding mold resin) in an embodiment of the present invention; FIG. 1 is a perspective view showing the structure of a case mold type capacitor (excluding mold resin) in an embodiment of the present invention; FIG. 1 is a perspective view showing the structure of a case mold type capacitor (excluding mold resin) in an embodiment of the present invention; FIG. FIG. 1 is a vertical cross-sectional side view showing the structure of a case mold type capacitor in an embodiment of the present invention; FIG. 2 is a side view of a longitudinal section showing the detailed structure of the main part of the case mold type capacitor in the embodiment of the present invention; FIG. 2 is a longitudinal cross-sectional side view for explaining the action of the main part of the case mold type capacitor in the embodiment of the present invention; FIG. 2 is a side view of a vertical cross section for explaining the problem of a case mold type capacitor in a comparative example with respect to the embodiment of the present invention; FIG. 2 is a front view showing the relationship between the insulating plate of the case mold type capacitor and the rising plate portion/external connection terminal portion of the bus bar in the embodiment of the present invention; A perspective view, a plan view, and a front view showing an insulating plate of a case mold type capacitor in an embodiment of the present invention. FIG. 2 is a vertical cross-sectional side view showing the detailed structure of the main part of a case mold type capacitor in another embodiment of the present invention; FIG. 10 is a side view of a vertical cross section showing the detailed structure of the main part of a case mold type capacitor according to still another embodiment of the present invention; FIG. 11 is a schematic configuration diagram of a main part of a case mold type capacitor according to still another embodiment of the present invention;

Embodiments of the case mold type capacitor of the present invention having the above configuration will be described below in detail at the level of specific examples.

1 to 12, 1 is a capacitor element, 2, 3 are a pair of first and second bus bars, 4 is an insulating plate (corresponding to the "insulating member" of the present invention), 5 is an exterior case, and 6 is a mold. Resin, A ₁ and A ₂ are minute gaps, and B is a gap expanding portion.

Capacitor element 1 is placed so that its axial direction is the vertical direction. One ends of a pair of first and second bus bars 2 and 3 are connected to a pair of positive and negative electrodes 1a and 1b of a P pole (anode) and an N pole (cathode) on both axial end surfaces of the capacitor element 1 . Each of the pair of busbars 2 and 3 is made entirely of a sheet of conductive metal such as a copper plate, and is bent into a generally crank shape. It has external connection terminal portions 2c and 3c at the bottom and raised plate portions 2b and 3b between the base portions 2a and 3a and the external connection terminal portions 2c and 3c. Each of the rising plate portions 2b and 3b is bent substantially perpendicular to the base portions 2a and 3a, and each of the external connection terminal portions 2c and 3c is bent substantially perpendicular to the rising plate portions 2b and 3b. .

The horizontal base portion 2a of the first bus bar 2 is overlapped with the electrode 1a on the upper surface side of the capacitor element 1, and the horizontal base portion 3a of the second bus bar 3 is overlapped with the electrode 1b on the lower surface side of the capacitor element 1. The connecting projections integrally projected from the bases 2a and 3a are electrically and mechanically connected to the electrodes 1a and 1b by soldering.

The rising plate portion 2b of the first busbar 2 and the rising plate portion 3b of the second busbar 3 are arranged close to each other so as to face each other in a vertical posture parallel to each other. An insulating plate 4 is inserted between them.

The insulating plate 4 is arranged in a state extending to both sides of the pair of bus bars 2 and 3, including the full width range of the overlapped region of the rising plate portions 2b and 3b facing each other (especially FIG. 1). (See FIGS. 3 and 8). The insulating plate 4 is also arranged to extend from a position higher than the upper edge 2b1 to a position lower than the lower edge of the rising plate portion _2b of the upper first bus bar 2 (see FIG. 4). ). A plate-like member made of resin is used as the insulating plate 4, but insulating paper may be used instead of the insulating plate, and any material may be used as long as it has insulating properties. As the insulating plate 4, for example, PPS (polyphenylene sulfide) is used.

The exterior case 5 has a rectangular parallelepiped shape, has an upward opening 5a, and is made of resin. The exterior case 5 accommodates the capacitor element 1, which is the main part of the capacitor unit, and one end of the pair of busbars 2 and 3 (the entire base except for the external connection terminals and most of the rising plate). and fixed with a molding resin 6 such as an epoxy resin. In the region where the pair of busbars 2 and 3 are embedded in the mold resin 6, the pair of busbars 2 and 3 and the insulating plate 4 face each other with a minute gap therebetween. The molding resin 6 is filled up to a position slightly lower than the height position of the opening 5a of the exterior case 5. As shown in FIG. In fixing the capacitor element 1 and the bus bars 2 and 3, the posture of the capacitor element 1 is performed in a state in which predetermined parallelism and orthogonality are ensured with respect to the exterior case 5 as shown in the drawing.

In the case mold type capacitor, first and second bus bars 2 and 3 are indirectly fixed to exterior case 5 via capacitor element 1 and mold resin 6 . However, both bus bars 2 and 3 are not directly supported by the exterior case 5, but are fixed by the mold resin 6 directly supported by the exterior case 5. As shown in FIG. Therefore, the first and second pairs of external connection terminal portions 2c and 3c, which are in the form of thin plate tongues and are susceptible to stress due to vibration loads, are not supported by the side plates of the exterior case 5 in their vicinity. The external connection terminal portions 2c and 3c are configured so as not to be directly connected to the exterior case 5. As shown in FIG. Therefore, both the external connection terminal portions 2c and 3c are susceptible to the stress caused by the vibration load. This aspect of the case mold type capacitor is the premise of the present invention (the base of the problem to be solved).

The upper edges 2b 1 and 3b 1 of the raised plate portions 2b and 3b of the pair of busbars ₂ and ₃ are located slightly lower than the upper edge 4a of the insulating plate 4. External connection terminal portions _2c and 3c having a small width and having a thin plate shape, that is, a tongue-like shape, project integrally from upper edges 2b ₁ and 3b 1 of the housing. One of the pair of external connection terminal portions 2c and 3c is a positive electrode, and the other is a negative electrode. Instead, the two external connection terminal portions 2c and 3c are arranged at different positions in the horizontal direction so as not to overlap each other to ensure insulation. The thin plate tongue-shaped external connection terminal portions 2c and 3c have flexibility (easiness of elastic deformation). As for the positive electrode and the negative electrode, in this embodiment, the first bus bar 2 is the negative electrode, and the second bus bar 3 is the positive electrode. The relationship between the positive electrode and the negative electrode may be reversed.

Both of the external connection terminal portions 2c and 3c are bent to a horizontal posture with a small radius of curvature from the vertical raised plate portions 2b and 3b. The external connection terminal portions 2c and 3c, except for their bent bases, are in a posture that is substantially perpendicular to the rising plate portions 2b and 3b. Screw insertion holes (fastening holes) 2d and 3d for fastening with are formed.

As shown in FIG. 5, the external connection terminal portion 3c of the second bus bar 3 having the lower base portion 3a is positioned higher than the external connection terminal portion 2c of the first bus bar 2 having the higher base portion 2a. are doing. In the case of the illustrated example, this is only due to the connection with the cable connection terminal from the external electrical equipment, and there is no necessity to do so. However, as a result of such an interlocking relationship, there is a difference in arm length between the pair of external connection terminal portions 2c and 3c. 2 is shorter than the length of the arm of the external connection terminal portion 3c in the bus bar 3 of No. 2.

Since the arm length of the first external connection terminal portion 2c is short, the first external connection terminal portion 2c is susceptible to the risk of breakage or breakage due to vibration load. On the other hand, the second external connection terminal portion 3c with the longer arm is less likely to be damaged or broken.

Here, the relationship between the length of the arm and the risk of breakage or breakage due to vibration load will be explained.

The gap dimension of the first micro gap _A1 formed between the first external connection terminal portion 2c and the insulating plate 4 and the second micro gap between the second external connection terminal portion 3c and the insulating plate 4 Assuming that there is no substantial difference from the gap dimension of the gap _A2 , and _furthermore , as _shown in FIG. Assume that A ₁ and the second minute gap A ₂ are substantially at the same height. That is, it is assumed that the highest position X ₁ of the first resin fixing portion 7 ₁ and the highest position X ₂ of the second resin fixing portion 7 ₂ are at the same height. In FIG. 7, the rows of "x" marks indicate the ranges of the resin fixing portions _{71 and 72} .

Since the second external connection terminal portion 3c has a long arm, it is less likely to be affected by stress due to vibration load, and the risk of breakage or breakage due to vibration load is small. On the other hand, since the first external connection terminal portion 2c has a short arm length, it is easily affected by stress due to vibration load, and there is a high risk of breakage or breakage due to vibration load. This is because the shorter the arm length, the greater the stress applied per unit length of the external connection terminal portion, and the longer the arm length, the smaller the stress per unit length (stress absorption and relaxation properties increase).

From this point of view, the first external connection terminal portion 2c, which is susceptible to the risk of breakage or breakage due to vibration load, is configured as follows in order to compensate for the lack of arm length. That is, the uppermost position X ₁ of the first resin fixing portion 7 ₁ shown in FIG. 7 is displaced downward as shown in FIG. , As a specific measure, as shown in the figure, in the vicinity of the upper end portion of the first minute gap _A1 formed between the insulating plate 4 and the first external connection terminal portion 2c, the insulating plate 4 is provided with a thickness direction. By forming a recessed portion 4b that is recessed into the gap, a gap expanded portion B that expands the gap dimension of the first micro gap _A1 is formed. In this embodiment, the gap widening portion B is realized as a recessed portion 4b formed in the insulating plate 4. As shown in FIG. The recessed portion 4b as the gap expanding portion B is a region where the first bus bar 2 is exposed from the mold resin 6 (a region higher than the upper surface of the mold resin 6), in this embodiment, near the root portion of the external connection terminal portion 2c. is formed in

In the second external connection terminal portion 3c with the longer arm, the uppermost position _X2 of the second resin fixing portion ₇₂ , which is the resin fixing portion between the insulating plate 4 and the insulating plate 4, is The first external connection terminal portion 2c, which has the shorter arm length, is positioned at approximately the same height as the upper edge 4a, and a gap expansion portion B is formed by the recessed portion 4b. Therefore, the highest position X ₁ of the first resin fixing portion 7 ₁ corresponds to the lowest position of the recessed portion 4 b and is located lower than the upper edge 4 a of the insulating plate 4 . That is, the widened gap portion B suppresses the mold resin from being sucked up. The recessed portion 4b extends from the upper region (upper edge 2b ₁ ) to the lower region of the rising plate portion 2b of the first bus bar 2 . As a result, the recessed portion 4b faces not only the first rising plate portion 2b, but also the root portion of the first external connection terminal portion 2c.

Due to the formation of the widened gap portion B, the uppermost position X of the first resin fixing portion 7 ₁ where the first external connection terminal portion 2c and the insulating plate 4 are fixed by the molten resin sucked up by capillary action. ₁ , as shown in FIG. 6, the second external connection terminal portion 3c and the insulating plate 4 are displaced downward from the uppermost position _X2 of the second resin fixing portion ₇₂ , where the second resin fixing portion 72 is fixed with the molten resin. , the length of the arm in the first external connection terminal portion 2c is lengthened (expanded). As a result, the risk of breakage or breakage of the first external connection terminal portion 2c due to the vibration load is suppressed satisfactorily.

In the above description, it has been explained that the length of the arm is extended by forming the recessed portion 4b as the gap expanding portion B in order to avoid the risk of breakage and breakage due to the vibration load. do.

The liquid level height h raised by capillary action is expressed as h=2T cos θ/(γ·r), where T is the surface tension, θ is the contact angle, γ is the specific gravity of the liquid, and r is the tube radius. That is, the lifted liquid level h is proportional to the surface tension T and cos θ, and inversely proportional to the specific gravity γ and the tube radius r. As r becomes smaller, h becomes larger. Further, as r becomes smaller, θ approaches 0 degrees and cos θ increases and approaches 1. Conversely, as r increases, h decreases and cos θ decreases and approaches zero. When r exceeds a certain limit, the capillary action stops working and the liquid level stops rising.

When the recessed portion 4b is formed in the insulating plate 4 to increase the size of the gap, the following phenomenon occurs. In other words, when the gap dimension of the gap expanded portion B by the recessed portion 4b increases beyond a certain limit, the capillary phenomenon does not occur. In the region of the first minute gap A ₁ below the lowest position of the recessed portion 4b, capillary action works and the molten resin is sucked up. Stops sucking up more.

In this embodiment, when the minute gap between the insulating plate 4 and the bus bar 2 is set to 0.15 mm, the gap dimension of the expanded gap portion B is expanded to 0.4 to 0.55 mm (the depth of the recessed portion 4b is increased to 0.25 to 0.4 mm), it was possible to suppress the sucking up of the molten resin into the gap expansion part B, but the gap dimension between the insulating plate and the bus bar, the material of the insulating plate and the mold resin etc. can be optimized.

In the embodiment of FIGS. 5 and 6, as for the formation of the recessed portion 4b as the gap expanding portion B, the horizontal center line of the recessed portion 4b and the first external connection terminal portion are aligned as shown in FIGS. The center line in the width direction (horizontal direction) of the first external connection terminal portion 2c is aligned with the center line of the first external connection terminal portion 2c, and the recessed portion 4b is formed over a width region protruding outward from both side edges in the width direction of the first external connection terminal portion 2c (especially in the figure). 8(c)). As a result, both ends in the width direction of the recessed portion 4b are in a state of being open to the space on the lateral sides toward the inside of the exterior case 5. As shown in FIG. Further, the recessed portion 4b is formed in an upward direction along the plate surface of the insulating plate 4 so as to be open to the upper space from the upper edge 4a of the insulating plate 4 (see FIG. 9 in particular).

Since the space of the recessed portion 4b communicates with the external space and is open in this way, the volume of the recessed portion 4b can be secured sufficiently large, and the action of blocking the sucking up of the molten resin by the capillary phenomenon in the recessed portion 4b is achieved. becomes sufficient. As a result, as described above, the uppermost position X ₁ of the first resin fixing portion 7 ₁ is lowered to extend the length of the arm of the first external connection terminal portion 2c, and the external connection terminal portion It is possible to secure the effect of preventing breakage and breakage of 2c.

In the above embodiment, the recessed portion 4b as the gap expanding portion B is formed in the insulating plate 4, but the side facing the first rising plate portion 2b instead of the second rising plate portion 3b is formed. A recessed portion 4b is formed in the side surface of the insulating plate 4 of . However, the present invention is not limited to this, and if the second external connection terminal portion 3c also has a risk of breakage or breakage due to vibration load, the recessed portion 4c (not shown) serving as a gap expanding portion may be used. ) is formed in the insulating plate 4, the recessed portion 4c is formed in the side surface of the insulating plate 4 facing the second rising plate portion 3b instead of the first rising plate portion 2b. .

Further, as another embodiment, recessed portions 4b and 4c (not shown) may be formed on both side surfaces of the insulating plate 4 as gap widening portions B. As shown in FIG.

In the embodiment shown in FIG. 10, the first and second pairs of external connection terminal portions 2c and 3c extend from the first and second rising plate portions 2b and 3b, respectively, in a posture substantially along the plate surface. It is In other words, both external connection terminal portions 2c and 3c extend almost straight up. In the case mold type capacitor having such a configuration, a concave portion 4b can be formed as a gap widening portion B on the side surface of the insulating plate 4 near the upper edge 4a, as in the above-described embodiment. Of the two side surfaces near the upper edge 4a of the insulating plate 4, the opposite side surface may be formed with a recessed portion 4c (not shown) as the gap expanding portion B, or the recessed portions 4b, 4c (not shown) may be formed on both side surfaces. (illustration omitted) may be formed.

In the above description, the gap widening portion B is formed by forming the recessed portion 4b (4c) in the insulating plate 4. However, as shown in FIG. The widening portion B may be formed by forming a recessed portion _2b2 recessed in the thickness direction by pressing or cutting a flexible metal plate. Alternatively, instead of the first external connection terminal portion 2c, the second external connection terminal portion 3c is formed with a recessed portion 2c ₂ (not shown) that is recessed in the thickness direction by pressing or the like to serve as the gap expansion portion B. Alternatively, recessed portions 2c ₁ and 2c ₂ (not shown) may be formed in both the first and second pairs of external connection terminal portions 2c and 3c.

Alternatively, the gap expanding portion B may be formed by bending the first external connection terminal portion 2c in a direction away from the plate surface of the insulating plate 4 . Alternatively, instead of the first external connection terminal portion 2c, the second external connection terminal portion 3c may be bent away from the plate surface of the insulating plate 4 to form the gap expansion portion B (not shown).

Further, various application modifications are possible with respect to the mode of forming the gap expanding portion B. As shown in FIG. A gap widening portion B may be formed by further spacing. For example, by bending the second rising plate portion 3c (or the first rising plate portion 2c) halfway in a crank shape, the upper side of the second rising plate portion 3c and the insulating plate 4 are separated. (FIG. 12(a)), or the lower side of the second rising plate portion 3c and the insulating plate 4 may be separated. Alternatively, the second external connection terminal portion 3c (or the first rising plate portion 2c) may be curved in a semicircular shape to separate it from the insulating plate 4 (FIG. 12(c)). Furthermore, the insulating plate 4 extending in the vertical direction is bent in the horizontal direction (bent at a substantially right angle) and extended, and the space between the second rising plate portion 3b and the second external connection terminal portion 3c is rounded. By bending, the second bus bar and the insulating plate 4 may be spaced apart at the bent portion. In the case of forming a recessed portion in the busbar to form the gap expanding portion, it is necessary to subject the busbar to press working or cutting, but bending can be achieved relatively easily.

INDUSTRIAL APPLICABILITY The present invention is useful as a technique for preventing breakage and breakage of tongue-shaped external connection terminals caused by vibration loads in case mold type capacitors.

REFERENCE SIGNS LIST 1 capacitor element 1a, 1b electrode 2 first bus bar 3 second bus bar 2a, 3a base portion 2b, 3b rising plate portion 2c, 3c external connection terminal portion 4 insulating plate 4b recessed portion (gap expansion portion)
5 Exterior case 5a Opening 6 Mold resin _A1 , _A2 minute gap B Expanded gap

Claims (5)

a capacitor element;
an exterior case having an opening and housing the capacitor element;
a pair of busbars having one end connected to a pair of positive and negative electrodes of the capacitor element and having an external connection terminal portion provided at the other end and arranged close to each other;
an insulating member inserted between the pair of bus bars;
A case mold type capacitor comprising: a mold resin filled in the outer case and embedding one end of the capacitor element and the pair of bus bars,
In a region where the bus bar is embedded in the mold resin, the bus bar and the insulating member face each other with a gap therebetween,
In at least a part of the region where the bus bar is exposed from the mold resin, there is provided a gap expanding portion that limits sucking up of the molten resin in the gap due to capillary action by expanding the gap dimension of the gap. formed as a recess recessed in the thickness direction of the insulating member ,
From the end face of the insulating member so that the thickness of the end face of the insulating member on the other end side of the pair of bus bars is thinner than the thickness of the non-formed portion of the insulating member where the recessed portion is not formed. A case mold type capacitor , wherein the recessed portion is formed over a predetermined region on one end side of a pair of bus bars . 2. The case mold type capacitor according to claim 1 , wherein said gap expanding portion as said recessed portion is formed over a width region of said insulating member that protrudes outward from both side edges in the width direction of said external connection terminal portion. 3. The case mold type capacitor according to claim 1, wherein said gap expanding portion is formed by separating a part of the facing surface of said bus bar facing said insulating member from said insulating member. The pair of bus bars have different arm lengths of the external connection terminal portions, and the gap expanding portion is formed between the bus bar having the shorter arm length of the external connection terminal portion and the insulating member. 4. The case mold type capacitor according to any one of claims 1 to 3 . 5. The case mold type capacitor according to claim 1, wherein the bus bar is fixed to the exterior case via the mold resin in a state in which it does not abut on the exterior case.

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