JP2015088633A - Case mold type capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve cost reduction of a fastener as to a case mold type capacitor in which a folded lead-out terminal plate is extended to the outside of a capacitor element along the peripheral surface of the element to lower the inductance thereof.SOLUTION: A lead-out terminal plate 2 connected to metal electrodes 1a at both ends of a capacitor element 1 is folded and extended to the outside of the element along the peripheral surface thereof. A bottomed box-shaped outer case 3 having an opening part contains the capacitor element 1. The capacitor element 1 and the lead-out terminal plate 2 are covered with mold resin 4 in the outer case 3. A fastening female screw 5 is fitted to the outer case 3. A fastening male screw 6 inserted in the lead-out terminal plate 2 is threadedly engaged with the fastening female screw 5 to fix the lead-out terminal plate 2 to the outer case 3. The fastening male screw 6 protrudes to the outside of the outer case 3, and a female screw 12 for connection is threadedly attached to the fastening male screw with a wiring conductor 8 inserted in the protruded portion.

Description

  According to the present invention, positive and negative lead terminal plates connected to the metal electrodes on both end surfaces in the axial direction of the capacitor element are bent to reduce inductance and extended to the outside of the element along the outer peripheral surface of the capacitor element. The present invention relates to a case mold type capacitor in which a capacitor element with a lead terminal plate is accommodated in an outer case and filled with a mold resin.

  The case mold type capacitor includes a capacitor element, a lead terminal plate, an exterior case, and a mold resin as its constituent elements (see, for example, Patent Document 1). Above all, the case mold type capacitor that is bent to the outside of the element along the outer peripheral surface of the capacitor element by bending the lead terminal board is excellent in reducing inductance because the length of the lead terminal board is as short as possible. Yes. In particular, in high-frequency driving of an in-vehicle inverter or the like, it is important to reduce inductance in order to reduce the loss on the circuit and improve efficiency, and to suppress heat generation at the time of switching surge voltage and ripple current.

<First Conventional Example>
FIG. 11 shows a first conventional example of a case mold type capacitor in which a lead terminal plate is bent and extended to the outside of the element along the outer peripheral surface of the capacitor element. 11A is a schematic longitudinal front view of the entire capacitor, FIG. 11B is an enlarged vertical front view of a part thereof, and FIG. 11C is a perspective view of a female screw / female type special fastener. . In FIG. 11, 1 is a flat columnar capacitor element, 1a is a metal electrode formed on both end surfaces in the axial direction of the capacitor element 1, and 2 is connected to the metal electrode 1a and bent substantially at a right angle along the outer peripheral surface of the element. A lead-out terminal plate of positive and negative electrodes extended to the outside of the element 3, 3 is a bottomed box-shaped outer case having an opening, and 4 covers the capacitor element 1 and the lead-out terminal plate 2 in the outer case 3. Filled mold resin. The exterior case 3 has a case main body 3a for storing the capacitor element 1 and a side extending from the case main body 3a to the side to place the lead terminal plate 2. The lead terminal plate 2 and an external plate-like wiring It is comprised from the case overhang | projection part 3b which forms a connection part with the conductor 8. FIG.

In the case mold type capacitor B of this system, a case projecting portion 3b that forms a connection portion between the lead terminal plate 2 and the external wiring conductor 8 is provided integrally with the outer case 3, and the lead terminal plate 2 Is extended to the outside of the element along the outer peripheral surface of the capacitor element 1 and then placed on the bottom plate part 3b ₁ of the case projecting part 3b, thereby sufficiently shortening the length of the lead terminal board 2; Low inductance is achieved.

The bottom plate portion 3b ₁ of the case overhang 3b special fastener 5A of the female screw-female screw type is embedded. As shown in FIG. 11 (c), the special fastener 5A includes an upper half female screw portion 5a and a lower half female screw portion 5b, and the respective female screw portions are integrated in a coaxial state. ing. A drawer terminal plate 2 is placed on the upper surface of the bottom plate portion 3b ₁ of the case overhanging portion 3b. A through hole 2a is formed near the end of the drawer terminal plate 2 at a position corresponding to the special fastener 5A. Yes. Then, after the conductive fastening male screw 6 is inserted into the through hole 2a, it is screwed and tightened from above with respect to the female screw portion 5a of the upper half of the special fastener 5A, and the lead terminal plate 2 is extended to the case. It is fixed to the part 3b. The fastening male screw 6 is inserted into the through hole 2 a of the lead terminal plate 2 after being inserted into the washer 7. The washer 7 is interposed between the head 6 a of the fastening male screw 6 and the lead terminal plate 2, and prevents the fastening male screw 6 from loosening. The lead terminal plate 2, the fastening male screw 6 and the special fastener 5A are made of a material having excellent conductivity, and the metal electrode 1a of the capacitor element 1 is the lead terminal plate 2, the fastening male screw 6, and the special fastener. It is in a state of being electrically connected to the female screw part 5b of the lower half part via the female screw part 5a of the upper half part of 5A.

  When wiring the case mold type capacitor B of the first conventional example configured as described above to the external connection device, the wiring conductor 8 is brought close to the lower surface of the case overhanging portion 3b, The through hole 8a is aligned with the female screw portion 5b of the lower half of the special fastener 5A, and the connecting male screw 9 passed through the washer 10 is inserted into the through hole 8a of the wiring conductor 8 before the special fastener 5A. The lower half female thread portion 5b is screwed and tightened from below.

  The effective screw length of the female screw portion 5a in the upper half of the special fastener 5A is set to a length sufficient for good and strong screwing and tightening of the fastening male screw 6 to the female screw portion 5a. The effective screw length of the half female screw portion 5b is set to a length sufficient for good and strong screw tightening of the connecting male screw 9 to the female screw portion 5b.

<Second Conventional Example>
FIG. 12 shows a second conventional example of a case mold type capacitor in which the lead terminal plate is bent and extended to the outside of the element along the outer peripheral surface of the capacitor element. 12A is a schematic longitudinal sectional front view of the entire capacitor, FIG. 12B is an enlarged longitudinal sectional front view, and FIG. 12C is a perspective view of a female screw / male thread type special fastener. In FIG. 12, the same reference numerals as those used in FIG. 11 indicate the same components, and a detailed description thereof will be omitted. In the second conventional example, instead of the special fastener 5A of the first conventional example, a special fastener 5B in which the upper half portion is a female screw portion 5c and the lower half portion is a male screw portion 5d is used. ing. The upper half female screw portion 5c and the lower half male screw portion 5d are integrated in a coaxial state. This female screw / male screw type special fastener 5B is different from the female screw / female screw type special fastener 5A of the first conventional example (FIG. 11 (c)) as shown in FIG. 12 (c). Only the upper half female screw portion 5c is embedded in the bottom plate portion 3b ₁ of the case protruding portion 3b. Male screw portion 5d of the lower half is not embedded in the bottom plate 3b _1, and projects downward in the bottom plate portion 3b _1.

  The conductive fastening male screw 6 is inserted into the through hole 2a of the lead terminal plate 2 and is then screwed and tightened from above to the female screw portion 5c of the upper half of the special fastener 5B. Is fixed to the case overhanging portion 3b. The special fastener 5B is also made of a material having excellent conductivity. The metal electrode 1a of the capacitor element 1 includes a lead terminal plate 2, a fastening male screw 6, and a female screw portion 5c in the upper half of the special fastener 5B. It is in the state electrically connected to the male screw part 5d of the lower half.

When wiring connecting to the second conventional example externally connected equipment case mold type capacitor C of which it is constructed as described above, from the bottom plate portion 3b ₁ of the through hole 8a of the case protruding portion 3b of the wiring conductor 8 The wiring conductor 8 is pressed against the lower surface of the case overhanging portion 3b by being inserted from below into the lower half male screw portion 5d protruding downward, and the washer 11 is pressed against the lower half male screw portion 5d. After the insertion, the connecting female screw 12 is screwed and tightened from the lower side to the male screw portion 5d of the lower half of the special fastener 5B.

  The effective screw length of the female screw portion 5c in the upper half of the special fastener 5B is set to a length sufficient for good and strong screw tightening of the fastening male screw 6 to the female screw portion 5c. . Further, the effective screw length of the male screw portion 5d of the lower half is set to a length sufficient for good and strong screw tightening of the connecting female screw 12 to the male screw portion 5d.

JP 2007-19136 A

  In the case mold type capacitor B of the first conventional example shown in FIG. 11, the shaft of the special fastener 5A in which the upper half female screw portion 5a and the lower half female screw portion 5b are integrated. This is the total length of the effective screw length of the female screw portion 5a and the effective screw length of the female screw portion 5b, which is considerably large. That is, each effective screw length is about 2 to 3 times the diameter of the fastening male screw 6. In the special fastener 5A of the first conventional example, the axial length of the fastening male screw 6 is The size is about 4-6 times as large as the diameter. Furthermore, the special fastener 5A has a complicated shape composed of an integral part of the female screw portion 5a in the upper half and the female screw portion 5b in the lower half, and the shaft length is considerably large as described above. Therefore, the cost required for the special fastener 5A is high.

  In the case mold type capacitor C of the second conventional example shown in FIG. 12, the shaft of the special fastener 5B in which the upper half female screw portion 5c and the lower half male screw portion 5d are integrated. This is the total length of the effective screw length of the internal female screw portion 5c and the effective screw length of the external screw portion 5d, which is considerably large. Moreover, the special fastener 5B has a complicated shape in which the upper half constitutes the internal thread portion 5c, the lower half constitutes the external thread portion 5d, and both are integral. However, the cost required for the special fastener 5B is high.

  The present invention was created in view of such circumstances, and in order to reduce inductance, the positive electrode and negative electrode lead terminal plates connected to the metal electrodes on both axial ends of the capacitor element were bent to surround the outer periphery of the capacitor element. An object of the present invention is to reduce the cost required for a fastener with respect to a case mold type capacitor that extends to the outside of the element along the surface.

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

The case mold type capacitor according to the present invention is:
A capacitor element;
A positive electrode and a negative electrode lead terminal plate which are bent after being connected to the metal electrodes on both end surfaces of the capacitor element in the axial direction and extended to the outside of the element along the outer peripheral surface of the element;
A bottomed box-shaped outer case having an opening and storing the capacitor element;
Mold resin filled so as to cover the capacitor element and the lead terminal plate in the outer case,
A fastening female screw fitted in the outer case;
A conductive fastening male screw inserted near the end of the lead terminal plate and screwed into the fastening female screw to fix the lead terminal plate to the exterior case;
The fastening male screw is screwed to the fastening female screw and further protrudes to the outside of the outer case, and the protruding length is inserted into the protruding portion through the external wiring conductor. It is characterized in that it is set to be longer than the effective screw length sufficient for screwing the female screw.

In the above configuration, the parts related to the capacitor element, the lead terminal plate, the outer case, and the mold resin described in the first half are not particularly different from the conventional example, and conceptually follow the conventional technology. It has become. The features of the present invention are described in the latter half. That is,
[1] The fastener fitted in the exterior case is a female screw (fastening female screw).

  [2] A conductive fastening male screw for fixing the lead terminal plate to the exterior case is inserted into the lead terminal plate and then screwed into the fastening female screw.

  [3] The fastening male screw protrudes further outside the outer case after being screwed onto the fastening female screw.

  [4] The projecting length is set to be equal to or greater than the effective thread length sufficient to screw the connecting female screw (external element) after the wiring conductor (external element) is inserted into the projecting portion.

  In the above configuration, the fastening male screw has the following three functions. The first function is to fix the lead terminal board to the outer case by screwing and tightening from the upper side to the fastening female screw fitted in the outer case, and the second is a connection that is an external component. This is a function of fixing the wiring conductor (external element) to the exterior case by screwing and tightening the female screw to the protruding portion of the fastening male screw from below. The third is the fastening male screw. This is a function of electrically connecting the lead terminal board to the wiring conductor via the wire.

  In the case of the first conventional example (FIG. 11), there is a female screw portion 5a in the upper half of the special fastener 5A as a portion supporting the fastening male screw 6, and special fastening as a portion supporting the connecting male screw 9. There is a female screw portion 5b in the lower half of the tool 5A. That is, the special fastener 5A requires two elements of the female screw portion 5a of the upper half portion and the female screw portion 5b of the lower half portion of each individual function. The fastening male screw 6 has a single function of fixing the lead terminal plate 2 to the outer case 3 by being screwed into the upper half female screw portion 5a. The connecting male screw 9 has a single function of fixing the wiring conductor 8 to the outer case 3 by being screwed into the female screw portion 5b of the lower half.

  In the case of the second conventional example (FIG. 12), there is a female screw portion 5c in the upper half of the special fastener 5B as a portion for supporting the male screw 6 for fastening, and special fastening as a portion for supporting the female screw 12 for connection. There is a male screw portion 5d of the lower half of the tool 5B. That is, the special fastener 5B requires two elements, that is, the female screw portion 5c of the upper half part and the female screw part 5d of the lower half part, each having an individual function. The fastening male screw 6 has a single function of fixing the lead terminal plate 2 to the outer case 3 by being screwed into the upper half female screw portion 5c. The connecting female screw 12 has a single function of fixing the wiring conductor 8 to the outer case 3 by screwing into the lower half male screw portion 5d.

  In the case of the present invention with respect to these conventional examples, there is a fastening female screw fitted as a part for supporting a fastening male screw, and a fastening male screw as a part for supporting a connecting female screw (external element) There is a protruding part. In other words, the fitted fastening female screw has a function of supporting the fastening male screw, and the fastening male screw is screwed to the fitted fastening female screw to fix the lead terminal board to the exterior case. It has both the function and the function of fixing the wiring conductor to the exterior case by screwing the connecting female screw (external element).

Furthermore, combining the functions in this way brings about an effect of shortening the axial length of the inserted female screw for fastening. In the case of the second conventional example, the reaction point when the connecting female screw 12 is tightened is the joint surface portion of the outer case 3 with the outer peripheral surface of the upper half female screw portion 5c with respect to the bottom plate portion 3b ₁ (FIG. 12 ( (See x) in b). That is, when the connecting female screw 12 is rotated in the tightening direction, the male screw portion 5d of the lower half of the special fastener 5B receives a forced pulling force along the axis. Opposing this is a joint surface portion (reaction point) with the outer peripheral surface of the female screw portion 5c in the upper half portion with respect to the bottom plate portion 3b ₁ . If the connecting female screw 12 is further rotated in the tightening direction beyond the specified value, the counter action at the reaction point breaks down and the bonding at the bonding surface is lost. The compulsory pulling-down force along the axis acting on the male screw portion 5d of the lower half is a force for tightening the special fastener 5B from above and below with the head 6a of the fastening male screw 6 and the connecting female screw 12. Must not. Therefore, the effective thread length of the upper half female thread part 5c must be considerably large. In this regard, the same applies to the first conventional example (see the cross in FIG. 11B).

  On the other hand, in the case of the present invention, the reaction point when the connecting female screw (external element) is tightened is the pressing portion from the fastening female screw fixed to the exterior case to the head of the fastening male screw. . That is, when the connecting female screw is rotated in the tightening direction, the fastening male screw receives a forced pull-down force along the axis. Opposing this is a pressing portion (reaction point) from the fixed fastening female screw to the head of the fastening male screw. Therefore, the connecting female screw and the fastening male screw exhibit a reaction force action so as to sandwich the fitted female screw from both sides in the axial direction. Therefore, the bonding strength between the outer peripheral surface of the fastening female screw and the outer case is not required to be as strong as the conventional example. Therefore, the effective thread length of the fastening female thread may be relatively small.

  According to the present invention, in order to reduce the inductance, the positive and negative lead terminal plates connected to the metal electrodes on both end surfaces in the axial direction of the capacitor element are bent and extended to the outside of the element along the outer peripheral surface of the capacitor element. In the case mold type capacitor, it is possible to employ a simple fastening female screw for a fastener fitted in the outer case as a fastening male screw counter part (one of a pair) for fixing the lead terminal plate. . In addition, since the fastening female screw is sandwiched and tightened between the head of the fastening male screw and the connecting female screw (external element), the effective screw length of the fastening female screw can be shortened. As a result, it is possible to advantageously reduce the cost required for the fastener.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic longitudinal front view (a) of a whole case mold type capacitor according to a first embodiment of the present invention, a vertical front view (b) in which a part thereof is enlarged, and a perspective view of a female screw for fastening to be inserted. c) The perspective view which looked at the capacitor | condenser element to which the drawer terminal board was connected in the case mold type capacitor of the 1st Example of this invention from diagonally downward from upper direction The perspective view which looked at the exterior case from diagonally downward from upper direction in the case mold type capacitor of the 1st example of the present invention The perspective view which looked at the state which accommodated the capacitor | condenser element with a drawer terminal board in the exterior case in the case mold type capacitor of the 1st Example of this invention from diagonally downward from upper direction FIG. 4 is a perspective view of the case mold type capacitor according to the first embodiment of the present invention viewed obliquely upward from below corresponding to FIG. 4. The perspective view which looked at the case mold type capacitor formed by filling mold resin in the case mold type capacitor of the 1st example of the present invention diagonally downward from the upper part FIG. 6 is a perspective view of the case mold type capacitor according to the first embodiment of the present invention when the case mold type capacitor is viewed obliquely upward from below corresponding to FIG. 6. 1 is a longitudinal front view showing a state in which a wiring conductor is connected to the case mold type capacitor of the first embodiment of the present invention. Schematic longitudinal front view of the entire case mold type capacitor of the second embodiment of the present invention FIG. 9 is a perspective view of the case mold type capacitor according to the second embodiment of the present invention as seen obliquely upward from below, corresponding to FIG. 9. 1 is a schematic longitudinal front view (a) of the entire case mold type capacitor of the first conventional example, a longitudinal front view (b) in which a part is enlarged, and a perspective view (c) of a female screw / female screw type special fastener. Overall schematic longitudinal front view (a) of the second conventional case-molded capacitor (a), a partially enlarged longitudinal front view (b), and a perspective view of a female screw / male thread type special fastener (c)

  In the case mold type capacitor of the present invention having the above-described configuration, the outer case and the fastening female screw configured as follows are one preferred mode. That is, with respect to the outer case, the case body and the lead terminal plate are placed integrally with the case body so as to project laterally, and a connection portion between the lead terminal plate and the external wiring conductor is formed. It consists of a case overhanging part. In addition, the fastening female screw is inserted into the case projecting portion. The fastening male screw is configured to project further outward and downward from the case projecting portion after being screwed onto the fastening female screw.

In the first conventional example (FIG. 11), the axial length of the special fastener 5A is also a bottom plate 3b ₁ of the thickness of the case overhang 3b embed special fastener 5A, becomes its thickness considerably larger Yes. When the thickness of the bottom plate portion 3b ₁ is large, the height H of the space portion X that can be secured below the bottom plate portion 3b ₁ is small. This means that the space for space is reduced when the case mold type capacitor B is connected to the external connection device by wiring.

In the case of the second conventional example (FIG. 12), the thickness of the bottom plate portion 3b ₁ of the case overhanging portion 3b in which the special fastener 5B is embedded is only the effective screw length of the upper half female screw portion 5c. conventional but is smaller than that of (11), in order from the bottom plate portion 3b ₁ of the presence of the male screw portion 5d of the lower half portion protruding downward, below the bottom plate 3b ₁ of the case extending portion 3b The height H of the space X that can be ensured is as large as that of the first conventional example.

  On the other hand, in the case of the present invention, as described above, the fastening female screw is effective since the female fastening screw is clamped and clamped between the head of the fastening male screw and the connecting female screw (external element). The screw length is shortened. As a result, in the case of the configuration of the above-described embodiment, the thickness of the case overhanging portion into which the fastening female screw is inserted can be reduced, and the space of the space portion below the case overhanging portion can be expanded, while the case mold type The effect of increasing the degree of freedom of capacitor placement is obtained.

  Moreover, in the case mold type capacitor of the present invention having the above-described configuration, the outer case and the fastening female screw configured as follows are a preferred embodiment. That is, the fastening female screw is inserted into the bottom plate portion of the exterior case. In addition, the fastening male screw is configured to protrude further outward and downward from the bottom plate portion of the exterior case after being screwed onto the fastening female screw. In this embodiment, unlike the configuration of the above-described embodiment, the outer case is not provided with a case overhanging portion, but an outer case having a structure that is simply expanded laterally is used.

  In the case of this embodiment, although it does not reach the effect of expanding the space, the effect of reducing the fastener cost is the same as described above under the condition that the connection portion with the wiring conductor is disposed at the portion corresponding to the bottom surface of the outer case. While maintaining the above, the effect of reducing the inductance can be exhibited by the configuration in which the bent lead terminal plate is extended to the outside of the capacitor element along the outer peripheral surface of the capacitor element.

  Moreover, in the case mold type capacitor of the present invention having the above-described configuration, it is preferable that the pair of lead terminal plates of the positive electrode and the negative electrode extend in parallel in the same direction. An antiparallel type extending in the opposite direction may be used, but a parallel type extending in the same direction can be configured more compactly.

<First embodiment>
Hereinafter, a first embodiment of a case mold type capacitor according to the present invention will be described in detail with reference to FIGS. FIG. 1 (a) is a schematic longitudinal front view of the entire case mold type capacitor of the first embodiment of the present invention, FIG. 1 (b) is a partially enlarged longitudinal front view, and FIG. 1 (c) is an insert. It is a perspective view of a female screw for fastening to be done. 2 is a perspective view of the capacitor element to which the lead terminal plate is connected viewed obliquely from above, FIG. 3 is a perspective view of the exterior case viewed obliquely from above, and FIG. 4 is a capacitor with a lead terminal plate attached to the exterior case. FIG. 5 is a perspective view of the element housed obliquely downward from above, FIG. 5 is a perspective view of obliquely upward from the bottom corresponding to FIG. 4, and FIG. 6 is a case mold type capacitor filled with mold resin. FIG. 7 is a perspective view of the case mold type capacitor viewed obliquely upward from below corresponding to FIG. 6. FIG. 8 is a longitudinal front view showing a state in which a wiring conductor is connected to a case mold type capacitor.

  In these drawings, A is a case mold type capacitor, 1 is a capacitor element, 1a is a positive electrode and a negative metal electrode formed on both end faces in the axial direction of the capacitor element 1, and 2 is connected to the metal electrode 1a and bent at a right angle. A positive and negative lead terminal plate extending in the same direction along the horizontal direction from the outer peripheral surface of the device to the outside of the device, 3 is a bottomed box-shaped outer case having an opening, and 4 is an outer case 3 The mold resin is filled so as to cover the capacitor element 1 and the lead terminal plate 2.

The outer case 3 includes a deep box-shaped case main body 3a that houses the capacitor element 1, and a shallow box-shaped case projecting portion 3b that projects from the case main body 3a to the side in the horizontal direction. The case overhanging portion 3b is integrally connected to the case main body 3a in an overhanging state. The depth dimension of the case body 3a is the same as the depth dimension of the case overhang portion 3b. A portion corresponding to the lateral lateral outer side of the case body 3a and the lower side of the case overhanging portion 3b is a space portion X. The capacitor element 1 to which the positive and negative lead terminal plates 2 and 2 are attached is accommodated in the outer case 3, but the capacitor element 1 is accommodated in the case body 3 a and the positive and negative lead terminal plates 2 and 2. Is placed on the upper surface of the bottom plate portion 3b ₁ of the case overhang portion 3b. The thickness of the bottom plate portion 3b ₁ of the case protruding portion 3b is larger than the thickness of the bottom plate portion 3a ₁ of the case body 3a. However, the thickness may be the same. Each of the positive and negative lead terminal plates 2 and 2 is connected to one of the metal electrodes 1a and 1a at both ends in the axial direction of the capacitor element 1 and is parallel to each other. The lengths of the vertical portions of the two lead terminal plates 2 and 2 are equal to each other, but one of the horizontal portions is longer and the other is shorter. The difference in length between the two lead terminal plates 2 and 2 coincides with the axial length of the capacitor element 1. The placement lengths of the lead terminal plates 2 and 2 on the case overhanging portion 3b are equal to each other. Through-holes 2a and 2a are formed in the vicinity of the end portions of the two lead terminal plates 2 and 2, respectively. The longitudinal direction of the horizontal portions of the lead terminal plates 2 and 2 is in a state orthogonal to the longitudinal direction of the case overhanging portion 3b. That is, the longitudinal direction of the horizontal portion of the two lead terminal plates 2 and 2 is the projecting direction of the case projecting portion 3b. This direction also coincides with the axial direction of the capacitor element 1. The case protruding portion 3b forms a connection portion between the lead terminal plates 2 and 2 and the external plate-like wiring conductors 8 and 8 (see FIG. 8).

Reference numeral 5 denotes a fastening female screw inserted into the bottom plate portion 3b ₁ of the case overhang portion 3b in a state where the axial direction is the vertical direction. The fastening female screw 5 is the upper end surface is positioned slightly above the upper surface of the bottom plate portion 3b _1, positioned below the slightly its lower end surface the underside of the bottom plate 3b _1. However, both surfaces may be flush. 6 is a conductive material that is vertically inserted into a through hole 2a formed in the vicinity of the end of the lead terminal plate 2 and is screwed into the fastening female screw 5 to fix the lead terminal plate 2 to the case overhanging portion 3b. It is a male screw for fastening. The fastening male screw 6 is screwed onto the fastening female screw 5 and further projects downward downward in the vertical direction to the outside of the bottom plate portion 3b ₁ of the case projecting portion 3b. The effective screw length is set to be equal to or longer than the effective screw length enough to screw the connecting female screw 12 through the external wiring conductor 8 (see FIG. 8). In this way, the lead terminal plate 2 is fixed to the case overhanging portion 3b by screwing and tightening the fastening male screw 6 and the fastening female screw 5.

Case projecting part 3b fastening female thread 5 which is inserted in the bottom plate 3b ₁ of, as shown in FIG. 1 (c), has a small cylindrical with axial length (thickness), the inner periphery of the through hole in the center The surface is threaded, and the outer peripheral surface is a smooth cylindrical surface. Its axial length is about the same as the diameter of the through hole. That is, the axial length is substantially the same as the diameter of the fastening male screw 6 and is sufficiently small, and is about one third of the diameter of the fastening female screw 5 itself. Along with this, the thickness of the bottom plate portion 3b ₁ of the case overhang portion 3b is substantially the same as the axial length of the fastening female screw 5 and is significantly thinner than the conventional example. 2 the lower portion of the fastening male screw 6 from the bottom plate portion 3b ₁ but projects downward, about a third of the effective thread length of the fastening male screw 6 the length of the projecting portion (screw portion total length) It has become.

Next, the operation of connecting the case mold type capacitor A to the positive and negative wiring conductors 8 and 8 extended from the circuit board or the like of the external connection device will be described with reference to FIG. The wiring conductor 8 for each of the positive electrode and the negative electrode is turned to the lower side of the bottom plate portion 3b ₁ of the case protruding portion 3b. Then, pressing the wiring conductor 8 fitted from the lower side from the bottom plate 3b ₁ relative fastening male screw 6 projecting downwardly through holes 8a of the wiring conductor 8 to the lower surface of the case overhang 3b, Further, after the washer 11 is fitted into the fastening male screw 6, the connecting female screw 12 is screwed and tightened from below to the fastening male screw 6. In this way, the wiring conductor 8 is fixed to the case projecting portion 3b by screwing and tightening the connecting female screw 12 and the fastening male screw 6.

Fastening the male screw 6 fixes the lead terminal plate 2 by screwing and tightening the fastening female thread 5 which is inserted in the bottom plate 3b ₁ of the case protruding portion 3b to the case protruding portion 3b. The fastening male screw 6 fixes the wiring conductor 8 to the case overhanging portion 3b by screwing and tightening the connecting female screw 12 with the wiring conductor 8 inserted. Further, the fastening male screw 6 is conductive together with the connecting female screw 12 and washers 7 and 11, and electrically connects the lead terminal plate 2 to the wiring conductor 8. Note that at least one of the washers 7 and 11 may be omitted.

The reaction point when the connecting female screw 12 is tightened becomes a contact surface portion of the head 6a of the fastening male screw 6 with respect to the case overhanging portion 3b. That is, when the connecting female screw 12 is rotated in the tightening direction, the fastening male screw 6 receives a forced pull-down force along the axis. It is to counter this a contact surface portion of the bottom plate portion 3b ₁ of the case protruding portion 3b with respect to the head 6a of the fastening male screw 6 (anti force point). Therefore, the connecting female screw 12 and the fastening male screw 6 exhibit a reaction force action so as to sandwich the fastening female screw 5 from both sides in the axial direction. Therefore, the insert junction surface of the bottom plate portion 3b ₁ of the outer peripheral surface and the case projecting portion 3b of the fastening female screw 5 is the bonding strength is not required as the prior art. Therefore, the effective screw length of the fastening male screw 6 may be relatively small.

As described above, according to the case mold type capacitor A of the first embodiment of the present invention, the following effects are exhibited. That is, in order to reduce the inductance of the lead terminal plate 2, the outer peripheral surface of the capacitor element 1 is formed by bending the positive and negative lead terminal plates 2, 2 connected to the metal electrodes 2, 2 on both axial end faces of the capacitor element 1. In the case mold type capacitor A that extends to the outside of the element along the outer surface of the outer case, the outer case is used as a counter part (one of the pair) of the fastening male screw 6 that fixes the lead terminal plate 2 to the outer case 3 (case protruding portion 3b). For the fastener to be inserted into 3 (the bottom plate portion 3b ₁ of the case overhang portion 3b), a simple fastening female screw 5 can be employed, and cost reduction can be advantageously promoted. In addition, since the fastening female screw 5 is clamped and clamped between the head 6a of the fastening male screw 6 and the connecting female screw 12, the effective screw length of the fastening female screw 5 can be shortened. It is done. Therefore, it is possible to adopt a fastening female screw 5 with a simple form and a sufficiently small effective screw length, and the cost can be advantageously reduced.

In the first embodiment, in particular, a case projecting portion 3b to the side is integrally provided in the outer case 3, and the fastening female screw 5 is inserted into the case projecting portion 3b. Since the thickness of the bottom plate portion 3b ₁ of the case overhanging portion 3b can be reduced, the height H of the space portion X below the case overhanging portion 3b is made larger than that of the conventional example to increase the space space. The effect of increasing the degree of freedom of arrangement of A is obtained.

<Second embodiment>
FIGS. 9 and 10 relate to the second embodiment of the present invention, FIG. 9 is a schematic longitudinal front view of the entire case mold type capacitor, and FIG. 10 is a diagonally upward view of the case mold type capacitor corresponding to FIG. FIG.

In the second embodiment, the outer case 3 is not provided with the case overhanging portion 3b as in the first embodiment, but instead of the outer case 3 having a structure (rectangular shape) that is simply expanded laterally. Use. The bottom plate portion 3b ₁ of the outer case 3 is thicker than the side plate portion. The capacitor element 1 to which the positive and negative lead terminal plates 2 and 2 are attached is upside down from the first embodiment, and the lead terminal plates 2 and 2 are in contact with the bottom plate portion 3b _1. The capacitor element 1 is accommodated in the outer case 3. There is a relatively large space on the lateral side of the capacitor element 1 in the outer case 3, and fastening is performed at a position below the space corresponding to the through holes 2 a and 2 a of the free end portions of the lead terminal plates 2 and 2. Female screws 5 and 5 are inserted into the bottom plate portion 3b ₁ . The fastening male screw 6 is screwed into the fastening female screw 5 and further projects downward downward in the vertical direction to the outside of the bottom plate portion 3b ₁ of the exterior case 3. As in the case of the first embodiment, the effective length of the fastening male screw 6 is sufficient to screw the connecting female screw 12 after the external wiring conductor 8 is inserted into the protruding portion. It is set to be longer than the screw length. In this way, the lead terminal plate 2 is fixed to the bottom plate portion 3b ₁ of the outer case 3 by screwing and tightening the fastening male screw 6 and the fastening female screw 5. Further, the capacitor element 1 and the lead terminal plate 2 are covered and protected by the mold resin 4 filled in the outer case 3 including the relatively large space portion on the lateral side of the capacitor element 1 described above.

  In the second embodiment, although there is no space-expanding effect, under the condition that the connection portion with the wiring conductor is disposed at a position corresponding to the bottom surface of the outer case 3, the first embodiment is different from the first embodiment. Similarly, while maintaining the effect of reducing the fastener cost, the effect of reducing inductance is exhibited by the configuration in which the bent lead-out terminal plates 2 and 2 extend to the outside of the element along the outer peripheral surface of the capacitor element 1. Become. Other configurations and operational effects are the same as in the first embodiment.

  In each of the above-described embodiments, the capacitor element 1 is originally cylindrical but is pressed in the diameter direction to form an oblong flat columnar body. The capacitor element 1 is configured as follows. That is, a metallized film comprising a dielectric film and a metal vapor-deposited electrode is wound to form a cylindrical metallized film wound body, and the outer film is further provided on the outer peripheral portion of the metallized film wound body. Is wound and fixed by thermal welding to obtain a composite film wound body, and this composite film wound body is pressed in the diametrical direction to form a capacitor element 1 having an oblong flat columnar body, and both axial ends thereof The metal electrodes 1a and 1a are formed by spraying metal fine particles. However, in the present invention, the structure of the capacitor element 1 is not necessarily limited to the one configured as described above, and any type of capacitor element 1 may be used.

  The fastening female screw 5 may be a hexagonal nut specification in addition to the cylindrical nut specification in the above embodiments.

  In each of the embodiments described above, the pair of lead terminal plates 2 and 2 for the positive electrode and the negative electrode are extended in parallel in the same direction, but may be extended in opposite directions.

  In each of the above embodiments, a plate-like conductor is used as the external wiring conductor, but a linear wiring conductor may be used instead.

  In each of the above embodiments, from the viewpoint of simplifying the manufacturing process and reducing the cost, the fastening female screw 5 is fitted into the outer case 3 by molding (insert molding) simultaneously with the resin. The fastening female screw 5 may be fitted to the outer case 3 by press-fitting (outsert) the female screw 5.

  The present invention relates to a case mold type capacitor in which a bent lead terminal plate is extended to the outside of the element along the outer peripheral surface of the capacitor element in order to reduce inductance, and the lead terminal plate and the wiring conductor (external element) are provided. This is useful as a technique for reducing the cost required for a fastener for fixing.

DESCRIPTION OF SYMBOLS 1 Capacitor element 1a Metal electrode 2 Leading terminal board 3 Exterior case 3a Case main body 3b Case overhanging part 4 Mold resin 5 Fastening female screw 6 Fastening male screw 8 Conductor for wiring A Case mold type capacitor X Space part

Claims (4)

A capacitor element;
A positive electrode and a negative electrode lead terminal plate which are bent after being connected to the metal electrodes on both end surfaces of the capacitor element in the axial direction and extended to the outside of the element along the outer peripheral surface of the element;
A bottomed box-shaped outer case having an opening and storing the capacitor element;
Mold resin filled so as to cover the capacitor element and the lead terminal plate in the outer case,
A fastening female screw fitted in the outer case;
A conductive fastening male screw inserted near the end of the lead terminal plate and screwed into the fastening female screw to fix the lead terminal plate to the exterior case;
The fastening male screw is screwed to the fastening female screw and further protrudes to the outside of the outer case, and the protruding length is inserted into the protruding portion through the external wiring conductor. A case mold type capacitor characterized in that it is set to have an effective screw length that is sufficient for screwing a female screw. The exterior case includes a case main body and a case protruding portion that integrally protrudes laterally from the case main body and mounts the lead terminal plate and forms a connection portion between the lead terminal plate and an external wiring conductor Consists of
The fastening female screw is fitted to the case projecting portion,
2. The case mold type capacitor according to claim 1, wherein the fastening male screw is further screwed into the fastening female screw and further protrudes outwardly from the case projecting portion. The fastening female screw is fitted to the bottom plate portion of the exterior case,
2. The case mold type capacitor according to claim 1, wherein the fastening male screw is screwed onto the fastening female screw and further protrudes outward and downward from a bottom plate portion of the exterior case.   The case mold type capacitor according to any one of claims 1 to 3, wherein the pair of lead terminal plates of the positive electrode and the negative electrode are extended in parallel in the same direction.

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