JP2015056513A - Resin mold type capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve mechanical reliability of a fitting strength in such a structure that a capacitor is fitted to an external fixing portion, in a caseless capacitor in which an exterior resin is molded with a thermosetting resin such as an epoxy resin having an inferior mechanical strength to that of a PPS resin.SOLUTION: A resin mold type capacitor includes: an exterior resin 40 which covers the whole of a capacitor unit 30 excluding a connection terminal portion 22 of an external extraction terminal 20 with molding; and a tool 60 to be fastened which is a member fastened with a fastening member 70 for fitted into an external fixing portion 80 and is insert molded to the exterior resin 40 in the state where the end is exposed. The tool 60 to be fastened has a member 61 to be fastened which is fastened directly to the fastening member 70, and a reinforcing resin layer 62 having higher strength than that of the exterior resin 40 integrally coupled to the outer peripheral portion of the member 61 to be fastened. The tool 60 to be fastened formed of the member 61 to be fastened and the reinforcing resin layer 62 is insert molded in the exterior resin 40.

Description

  The present invention relates to a caseless resin-mold type capacitor used for industrial machines, vehicles, and the like, and relates to a technique for improving the mechanical reliability of the mounting strength to an external fixing part.

  The mold type capacitor is formed by coating the entire capacitor unit (excluding the connection terminal portion of the external lead terminal) having one or a plurality of capacitor elements and the external lead terminal with an exterior resin by molding. As described above, the mold type capacitor for resin molding the capacitor unit is roughly classified into a case storage type capacitor and a caseless resin mold type capacitor.

  A case storage type capacitor is made by storing a capacitor unit in a resin or metal outer case, and filling and curing an electrically insulating thermosetting resin such as an epoxy resin between the outer case and the capacitor unit. Is. As this type of capacitor, for example, Patent Document 1 (Japanese Patent Laid-Open No. 2009-252934), Patent Document 2 (Japanese Patent Laid-Open No. 2013-77832), Patent Document 3 (Japanese Patent Laid-Open No. 2012-243931), Patent Document 4 (Japanese Unexamined Patent Application Publication No. 2013-44341) and Japanese Unexamined Patent Application Publication No. 2011-77232 (Japanese Unexamined Patent Application Publication No. 2011-77232). In the case storage type capacitors of Patent Document 3 and Patent Document 5, those made of PPS (polyphenylene sulfide) or PBT (polybutylene terephthalate) are used as the outer case. These resins are excellent in heat resistance, moisture resistance, water resistance, oil resistance, impact resistance, environmental properties, light weight, and the like. In particular, PPS resin is superior to PBT resin of special engineering plastics in terms of mechanical strength, can withstand harsh usage conditions, and is useful for securing the strength of mounting on external fixed parts, and is most used due to its characteristics and workability One of the proven resins. The exterior case made of PPS resin or PBT resin has better mechanical strength than epoxy resin.

  On the other hand, a resin mold type capacitor is produced by housing a capacitor unit in a mold, pouring and filling a molten thermosetting resin into a cavity in the mold, and releasing the mold after waiting for its curing. There is no exterior case as in the case of a case storage type capacitor. Instead, the outer periphery of the capacitor unit is covered and protected by an exterior resin itself by molding (the outer shell of the capacitor itself is a mold resin). The epoxy resin as the material of the mold resin is excellent in heat resistance, moisture resistance, insulation, moldability (curing shrinkage characteristics), and has resistance to deterioration of capacitor characteristics due to changes in external temperature and humidity. Epoxy resins are particularly rich in fluidity, and are widely used as mold resins from the viewpoint of high quality moldability.

  However, the adhesive strength between the PPS resin and the epoxy resin is low, and there is a problem in molding with the epoxy resin after the capacitor unit is accommodated in the outer case made of PPS resin. In the case of a case storage type capacitor having an outer case made of PPS resin or PBT resin, which has higher mechanical strength than epoxy resin, there is an advantage that mechanical reliability of attachment strength to an external fixing portion is high. On the other hand, however, there is a problem in terms of productivity and cost in that an extra member called an outer case is required compared to a resin mold type capacitor. In the case of a caseless resin mold type capacitor, the capacitor unit is directly covered and protected by the mold resin, which is advantageous in terms of the number of members and the number of manufacturing steps. On the other hand, however, the mechanical strength of the attachment to the external fixing portion is weaker than that of the case storage type capacitor with the exterior case made of PPS resin or PBT resin, and there remains a problem in reliability.

  Hereinafter, the structure of the attachment to the external fixed part in the resin mold type capacitor to which the present invention is applied will be described.

  4 is a perspective view showing a structure of a resin mold type capacitor B of a prior art example, FIG. 5 is an enlarged view of the vicinity of a fastener, and (a) is a cross-sectional view showing a state before being attached to a fixing part. b) is a cross-sectional view showing a state of attachment to a fixed portion. In these drawings, 10 is a capacitor element, 15 is a laminate of a plurality of capacitor elements 10, and 20 is an external lead terminal connected to the metal electrodes 11 at both ends in the axial direction of each capacitor element 10 in the laminate 15 of capacitor elements. , 30 is a capacitor unit comprising a multilayer body 15 of capacitor elements and an external lead terminal 20. A plurality of capacitor elements 10 are stacked in the vertical direction, and are further arranged in parallel in the horizontal direction to form a stacked body 15. The external lead terminal 20 includes a rectangular terminal plate 21 joined to the upper end surface of the laminate 15, a connection terminal portion 22 bent and connected in a hook shape from the terminal plate 21, and the terminal plate 21 and a plurality of capacitors. The connection plate (bus bar) 23 is soldered over the metal electrode 11 of the element 10.

  The capacitor unit 30 is entirely covered with an exterior resin 40 except for the connection terminal portion 22 of the external lead terminal 20, thereby forming a resin mold type capacitor B. The exterior resin 40 constitutes the outer shell of the resin mold type capacitor B.

  Reference numeral 60 denotes a fixed fastener (nut) for fixing attachment inserted into the exterior resin 40 in an exposed state of the end. The plurality of inserted fasteners 60 are screwed into fastening members (bolts) 70 when the resin-molded capacitor B is attached and fixed to a fixing portion 80 such as a frame of an electric vehicle or an industrial electric device. Part.

  In the case of a case storage type capacitor having an outer case made of PPS resin or PBT resin as an outer shell, when the outer case itself is molded and manufactured for attachment to an external fixing part, The fastener is insert-molded, or the fastener is embedded or press-fitted after molding.

  In the case storage type capacitor described in Patent Document 1 (Japanese Patent Laid-Open No. 2009-252934) and Patent Document 2 (Japanese Patent Laid-Open No. 2013-77832: divisional application of Patent Document 1), an inner resin case and an outer metal Has a double case structure. In a capacitor in which a capacitor unit is housed in a resin outer case and filled and cured with mold resin, a flange-like fastening portion projects integrally with the outer case, and the outer case is attached to a metal case as a fixing portion. A collar through which the bolt is inserted is insert-molded in the flange-like fastening portion. The bolt is screwed into an internal thread formed on the metal case itself.

  In the case storage type capacitor described in Patent Document 3 (Japanese Patent Laid-Open No. 2012-243931), a metal collar with a buffer member is embedded in a flange portion that is formed so as to protrude integrally from a resin case. The buffer member is a sheet made of a rubber-based, silicon-based, fluorine-based, or urethane-based resin, and is provided on the outer peripheral side surface of the metal collar so that the metal collar does not directly contact the flange portion. The metal case as an external mounting member of the case storage type capacitor is provided with a flange cradle for receiving the flange part of the resin case, and the screw through which the metal collar is inserted is screwed into the female thread part of the flange cradle in the metal case. Yes.

  In a resin product with a metal member described in Patent Document 4 (Japanese Patent Application Laid-Open No. 2013-44341), a metal collar is embedded in the resin product by insert molding, and a knurling process or the like is performed on the outer peripheral surface of the collar to prevent the collar from falling off The uneven processing is given.

  In the case storage type capacitor described in Patent Document 5 (Japanese Patent Laid-Open No. 2011-77232), an insert nut as a fastener is embedded in an exterior case made of PPS resin or PBT resin. An exterior case made of PPS resin or PBT resin has high mechanical strength, and has mechanical reliability of attachment strength to an external fixing portion.

JP 2009-252934 A JP 2013-77832 A JP 2012-243931 A JP2013-44341A JP 2011-77232 A

  Of the above five patent documents, only the patent document 5 is insert-molded with the fasteners (nuts), and the other patent documents 1 to 4 are not fastened but simply fastened. A member (bolt) insertion collar. Bolts are simply inserted into the collar. Since the screwing partner is a metal case, there is no problem in terms of mechanical strength.

  The capacitor of Patent Document 5 is a case storage type capacitor (the insert nut is embedded in an outer case of PPS or PBT), and is not a resin mold type capacitor. The capacitor disclosed in Patent Document 5 has the above-described problem in the resin mold type capacitor (the subject of the present invention) whose outer shell is an outer resin formed by molding (as compared with a case storage type capacitor with an outer case of PPS or PBT). The problem that the mechanical strength of the attachment to the fixed part of this is weak is not inherent.

  In the conventional resin mold type capacitor B shown in FIG. 4, there is a problem in the mechanical reliability of the mounting strength with respect to the external fixing portion 80. That is, it is the exterior resin 40 that is inserted with a tubular fastener 60 into which a fastening member (bolt) is screwed in order to attach and fix the resin mold type capacitor B to the fixing portion 80. It is not the exterior case that inserts the fastener 60. In the first place, a resin mold type capacitor does not use an outer case. In the case of a molded capacitor using an outer case, a fastener (insert nut) is embedded in the outer case. A preferred example of this is the case storage type capacitor disclosed in Patent Document 5. Other Patent Literatures 1 to 4 merely embed a collar (metal collar) having a smooth inner peripheral surface that does not have a female screw portion, not a fastener (insert nut) having a female screw portion for screwing. The collar is not a fastener.

  In the case of a case storage type capacitor, it is a general tendency in recent years to use a PPS resin or a PBT resin as a mold resin for insert-molding a fastener (insert nut) when the outer case itself is produced by molding. The PPS resin or PBT resin has high mechanical strength, and the mechanical coupling force between the inserted fastener to be fastened and the mold resin (PPS resin or PBT resin) becomes sufficiently large. Therefore, when the fastening member (bolt) inserted through the through hole of the external fixing part (frame or plate) is screwed to the fastener and the case storage type capacitor is attached and fixed, the mechanical reliability of the attachment strength is It will be high enough.

  However, in the case of the resin mold type capacitor of the caseless object of the present invention, the exterior resin for embedding the fastener (insert nut) is an epoxy resin or urethane resin whose mechanical strength is inferior to that of the PPS resin or PBT resin. And other thermosetting resins. As a result, the mechanical reliability around the fastener is greatly reduced.

  More specifically, when the capacitor expands or contracts with a change in temperature, peeling occurs at the interface between the fastener (insert nut) and the exterior resin due to the difference in linear expansion coefficient between the resin and the metal. In particular, when the exterior resin is an epoxy resin, interfacial delamination is likely to occur due to a large difference in linear expansion coefficient from the fastener and a low mechanical strength. Details are as follows. As shown in FIG. 5B, the fastener 60 is firmly fixed to the fixing portion 80 via a fastening member (bolt) 70. Therefore, the fastener 60 itself does not move (no change in position) even when the capacitor is expanded or contracted due to a temperature change. However, the portion of the exterior resin 40 made of an epoxy resin or the like is not directly fixedly connected to the fastening member 70, and is occupied with a large expansion / contraction because the occupied volume ratio is large. That is, the exterior resin 40 is greatly displaced with respect to the stationary fastener 60 that is not moved, and the exterior resin 40 results in interfacial peeling with the fastener 60. Once the interface peeling occurs, as illustrated in FIG. 6, the crack 90 enters the surface portion 40 a of the exterior resin 40 made of an epoxy resin or the like having a low mechanical strength starting from the interface peeling point P. The crack 90 has progressed, and the fastener 60 may eventually fall off the exterior resin 40.

  In the molded capacitors disclosed in Patent Documents 1 and 2, it is a collar that is insert-molded into the flange-like fastening portion of the inner resin case, and is not an insert-type fastener to be inserted like an insert nut. Further, the metal collar is inserted into the inner resin case, and is not inserted into an exterior resin made of a resin mold. In this sense, there is a difficulty in applying the techniques of Patent Documents 1 and 2 to the resin mold type capacitor that is the subject of the present invention. This is because an exterior resin made of a resin mold has higher fluidity from the viewpoint of moldability (curing shrinkage characteristics), and therefore is made using an epoxy resin, a urethane resin, or the like that is inferior in mechanical strength. Therefore, there is a problem of low mechanical strength around the insert-type fastener when the insert-type fastener is embedded in an exterior resin made of a resin mold having relatively low mechanical strength. However, the resin case is made of PPS resin or PBT resin having excellent mechanical strength. When a metal collar is embedded in the resin case having high mechanical strength, the above-described problem (the machine around the collar) This is because a low strength is less likely to occur.

  In the mold capacitor of Patent Document 3, the insert type fastener is embedded in an exterior case made of PPS resin having excellent mechanical strength. Here, a resin mold having relatively low mechanical strength. There is no problem of low mechanical strength around the insert-type fasteners when the insert-type fasteners are embedded in the exterior resin made in the above.

  Therefore, there is a difficulty in applying the technique of Patent Document 3 to the resin mold type capacitor that is the subject of the present invention.

  In the molded capacitor disclosed in Patent Document 4, what is insert-molded into a resin product is a collar, not an insert-type fastener to be inserted like an insert nut. In this sense, there is a difficulty in applying the technique of Patent Document 4 to the resin mold type capacitor that is the subject of the present invention.

  In the molded capacitor disclosed in Patent Document 5, the insert type fastener is embedded in an outer case made of PPS resin or PBT resin having excellent mechanical strength. Therefore, there is no problem of low mechanical strength around the insert-type fastener when the insert-type fastener is embedded in an exterior resin made of a weak resin mold.

  Therefore, there is a difficulty in applying the technique of Patent Document 5 to the resin mold type capacitor that is the subject of the present invention.

  The present invention was created in view of such circumstances, and for a resin mold type capacitor in which an exterior resin is molded, a fastening member is fastened to a member to be fastened and the resin mold type capacitor is attached to an external fixing portion. An object of the present invention is to prevent the occurrence of cracks in the exterior resin and improve the mechanical reliability of the mounting strength.

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

The resin mold type capacitor according to the present invention is:
A capacitor unit having one or more capacitor elements and an external lead terminal;
An exterior resin that covers the entire capacitor unit by molding except the connection terminal portion of the external lead terminal; and
It is a member fastened with the fastening member for attaching to an external fixing part, Comprising: The to-be-fastened tool insert-molded in the edge part exposure state to the said exterior resin is provided.

  And the said to-be-fastened tool has the to-be-fastened member directly fastened with the said fastening member, and the reinforcement resin layer stronger than the said exterior resin integrally joined to the outer peripheral part of this to-be-fastened member, A fastener to be fastened comprising a member to be fastened and a reinforcing resin layer is insert-molded in the exterior resin.

  In the fastener to be fastened in the present invention, a reinforcing resin layer having a strength higher than that of the exterior resin is integrally bonded to the outer peripheral portion of the member to be fastened. This increases the mechanical strength (action of a high-strength reinforcing resin layer). As a result, despite the fact that the exterior resin that is inferior in mechanical strength compared to the reinforcing resin layer is molded (the outer shell is not the exterior case but the mold resin itself involved in the molding), In the structure in which the fastening member is fastened to the fastening member and the resin mold type capacitor is attached to the external fixing portion, the mechanical reliability of the attachment strength can be greatly improved.

  In particular, the reinforcing resin layer that is integrally bonded to the outer periphery of the member to be fastened and has a higher strength than the exterior resin has a difference between the linear expansion coefficient and the linear expansion coefficient of the exterior resin. It becomes smaller than the difference in coefficient of linear expansion between the member and the exterior resin. In other words, the reinforcing resin layer having a strength higher than that of the exterior resin interposed between the exterior resin and the member to be fastened exerts a buffering effect on thermal stress against the expansion / contraction of the exterior resin due to temperature change. It has a function to prevent peeling. As a result, generation of cracks due to temperature changes is prevented in the exterior resin.

  According to the present invention, regarding a resin mold type capacitor in which an exterior resin having a mechanical strength inferior to that of a reinforcing resin layer is molded, a fastening member is fastened to a member to be fastened and the resin mold type capacitor is connected to an external fixing portion. In the attached structure, it is possible to prevent cracking of the exterior resin due to temperature change and improve the mechanical reliability of the attachment strength.

The perspective view which shows the whole structure of the resin mold type capacitor of the Example of this invention The resin mold type | mold capacitor of the Example of this invention expands and shows the vicinity of a to-be-fastened tool, and is sectional drawing (a) which shows the state before attaching to a fixing | fixed part, and sectional drawing which shows the attachment state to a fixing | fixed part ( b) The perspective view (a), front view (b), and top view (c) which show the structure of a to-be-fastened fastener in the resin mold type capacitor | condenser of the Example of this invention. The perspective view which shows the whole structure of the resin mold type capacitor of a prior art example In the resin mold type capacitor of the prior art example, an enlarged view of the vicinity of the fastener is shown, a cross-sectional view showing a state before being attached to the fixed portion (a) and a cross-sectional view showing the state of being attached to the fixed portion (b) Front view to point out problems in the resin mold type capacitor of the prior art example

  The resin mold type capacitor of the present invention having the above configuration has several preferred embodiments as follows.

  About the to-be-fastened member of the said insert-type to-be-fastened tool, it is preferable to set it as the insert nut in which the fastening effect | action part was formed in the internal thread. However, it is not limited to the insert nut, but may be an insert bolt. In the case of an insert bolt, a nut is used as the fastening member. Rivet fastening or caulking fastening may be used.

  About the said reinforced resin layer, what the uneven | corrugated | grooved part is formed in the outer surface part is preferable. The uneven portion formed on the outer surface of the reinforcing resin layer increases the bonding area between the fastener and the exterior resin to increase the joint strength, and prevents relative displacement of the fastener to the exterior resin. The mechanical reliability of the mounting strength with respect to the fixed part of the mold capacitor can be further improved.

  About the uneven | corrugated | grooved part formed in the said reinforcement resin layer, the thing by which the cyclic | annular bulging part and circumferential groove part around the axis line of the said to-be-fastened member are alternately arrange | positioned along an axial direction is preferable. When the concavo-convex portion is configured by the annular bulging portions and the circumferential groove portions alternately arranged along the axial direction, the displacement along the axial direction of the fastener can be prevented with respect to the prevention of relative displacement of the fastener to the exterior resin. (Retaining effect).

  As for the reinforcing resin layer, it is also preferable that a protruding portion that protrudes outward in the radial direction and is integrally formed with a protrusion that is prevented from rotating in the circumferential direction around the axis by fitting with the exterior resin. In the case of the annular bulging portion and the circumferential groove portion described above, there is a retaining effect in the axial direction, but it is difficult to expect a detent effect around the axial line. Therefore, if a protrusion is provided on the reinforcing resin layer and fitted with the exterior resin, the effect of preventing rotation is exhibited.

  Further, with respect to the reinforcing resin layer, annular bulges and circumferential grooves around the axis of the fastened member are alternately arranged along the axial direction, and each of the annular bulges is radially outward. There is also an aspect in which a protruding portion that protrudes in the direction and is prevented from rotating in the circumferential direction around the axis by fitting with the exterior resin is integrally formed. In this case, both the retaining effect and the non-rotating effect can be exhibited, and the mechanical reliability of the mounting strength can be further improved.

  In forming the rotation-preventing protrusions on the reinforcing resin layer, it is preferable that a plurality of the protrusions be spaced along the axial direction of the fastened member. By using a plurality of protrusions, the bonding area between the fastener and the exterior resin can be increased, and the mechanical reliability of the mounting strength can be further improved.

  The exterior resin is preferably an epoxy resin or a urethane resin. Epoxy resins and urethane resins are extremely excellent in moldability, and the mechanical reliability of the mounting strength can be improved while taking advantage of this advantage.

  The reinforcing resin layer is preferably PPS (polyphenylene sulfide) or PBT (polybutylene terephthalate). PPS resin and PBT resin are superior in mechanical strength to epoxy resin and urethane resin, and this reinforcing resin layer made of PPS resin or PBT resin is placed between the fastening member and the exterior resin of epoxy resin or urethane resin. By interposing it in, it becomes possible to rationally strengthen the mechanical strength around the fastener.

  Hereinafter, embodiments of a resin mold type capacitor according to the present invention will be described in detail with reference to FIGS.

  FIG. 1 is a perspective view showing the overall structure of a resin mold type capacitor, FIG. 2 is an enlarged view of the vicinity of a fastener, (a) is a cross-sectional view showing a state before being attached to a fixing portion, and (b) is Sectional drawing which shows the attachment state to a fixing | fixed part, FIG. 3 shows the structure of a to-be-fastened tool, (a) is a perspective view, (b) is a front view, (c) is a top view.

  In the resin mold type capacitor A according to the embodiment of the present invention, main members are the capacitor unit 30, the exterior resin 40, and the fastener 60, and the capacitor unit 30 includes the capacitor element 10 and the external lead terminal 20 as main components. The fastened tool 60 includes a fastened member 61 and a reinforcing resin layer 62 as main components.

  For the capacitor element 10 in the capacitor unit 30, a capacitor element laminate 15 is used in this embodiment. That is, a plurality of capacitor elements 10 are stacked in the vertical direction, and are arranged in parallel in the horizontal direction to form the stacked body 15. The laminated body 15 may be one in which the capacitor elements 10 are laminated in the vertical direction, or may be laminated in three or more rows. Further, the capacitor unit 30 may be composed of only one capacitor element 10 instead of a laminated body. Reference numeral 11 denotes a metal electrode, 21 denotes a terminal plate, 22 denotes a connection terminal portion, and 23 denotes a connection plate. Since these are not directly related to the gist of the present invention, they will be described together. Reference numeral 70 denotes a fastening member as a related external component, and specifically uses a fastening bolt.

  The capacitor unit 30 is entirely covered by molding of a molten resin except for the connection terminal portion 22 of the external lead terminal 20, and the exterior resin 40 as a result of curing of the molten resin forms the outer shell of the resin mold type capacitor A. Yes.

  In the resin mold type capacitor A of the present embodiment, an adhesive (material) and an adhesive (material) are preliminarily provided at predetermined locations on the inner peripheral surface of a molding frame (not shown) at the time of molding. The fasteners 60 are fastened using an adhesive tape or the like. Therefore, after molding, the plurality of fasteners 60 are insert-molded into the exterior resin 40 with the end portions exposed.

  As described above, the capacitor unit 30 having the capacitor element laminate 15 and the external lead terminals 20 is coated with the exterior resin 40 by molding, and the fasteners 60 are embedded in the exterior resin 40 in an exposed state. When the resin mold type capacitor A is attached and fixed to an external fixing part (frame or the like) 80 in actual use, the following structure is implemented. That is, the end surface of the resin mold type capacitor A is brought into contact with the fixing portion 80, the exposed end portion of the fastener 60 is aligned with the through hole 80a in the fixing portion 80, and the fastening member 70 is aligned with the through hole 80a. Then, the resin mold type capacitor A is attached and fixed to the fixing portion 80.

  Next, the fastener 60 will be described in detail with reference to FIGS.

  As shown in FIGS. 2 (a) and 2 (b) and FIGS. 3 (a) and 3 (b), the fastener 60 according to the present embodiment is a member to which a fastening member (bolt) 70 is directly actuated (screwed). The fastening member 61 and the reinforcing resin layer 62 integrally coupled to the outer peripheral portion of the fastened member 61 are configured. The reinforcing resin layer 62 is made of a material having higher strength than the exterior resin 40. The constituent material of the exterior resin 40 is an epoxy resin or a urethane resin excellent in moldability, whereas the constituent material of the reinforcing resin layer 62 is a PPS (polyphenylene sulfide) resin or PBT (polybutylene terephthalate) excellent in mechanical strength. ) Resin. PPS resin and PBT resin have higher mechanical strength than general-purpose epoxy resin and urethane resin. A fastener 60 including a member to be fastened (nut) 61 and a reinforcing resin layer 62 integrally coupled to the outer periphery thereof is insert-molded in the exterior resin 40 in an exposed state. In this embodiment, the fastened tool 60 is a nut (insert nut) whose fastening action portion is formed on a female screw.

  In the present invention, the form of the reinforcing resin layer 62 on the outer peripheral portion of the fastened member (nut) 61 is not questioned. However, in this embodiment, the uneven portion 63 is formed on the outer peripheral surface of the reinforcing resin layer 62. Has been. The concavo-convex portion 63 is formed by alternately arranging annular bulging portions 63a and annular circumferential groove portions 63b around the axis of the fastened member (nut) 61 along the axial direction. Further, in each of the plurality of annular bulges 63a, a protrusion 63c protruding outward in the radial direction is integrally formed. Here, the plurality of protrusions 63c are linearly arranged along the axial direction at two locations in the circumferential direction so as to face each other in the diameter direction. The plurality of protrusions 63c are spaced along the axial direction. In addition, about the arrangement | positioning of the projection part 63c, you may arrange | position to three or more places in the circumferential direction, or may be one place in the circumferential direction. In the arrangement in a plurality of places in the circumferential direction, it is preferable to make the arrangements uniform, but they may be unequal. Moreover, it may replace with linearly along an axial direction, and may arrange | position helically. Further, instead of disposing the protrusions 63c on all of the plurality of annular bulges 63a, the protrusions 63c may be selectively disposed on the plurality of annular bulges 63a. Further, the protrusion 63c is not particularly required, and at least one protrusion may be provided.

  In this embodiment, in the interrelationship between the concavo-convex portion 63 and the exterior resin 40 in the reinforcing resin layer 62, a plurality of annular bulge portions 63a ... bite into the exterior resin 40, and a part of the exterior resin 40 is ... Bite into the plurality of annular circumferential groove portions 63 b... And a plurality of protrusions 63 c. Therefore, the fastened tool 60 with the reinforcing resin layer 62 on the fastened member (nut) 61 exhibits a high retaining effect in the axial direction with respect to the exterior resin 40 and also exhibits a high anti-rotation effect in the circumferential direction. Will do.

  The annular bulging portions 63a and the circumferential groove portions 63b are effective mainly for preventing the slipping off in the axial direction. However, since the joining area with the exterior resin 40 in the circumferential direction is large, the rotation preventing effect in the circumferential direction is effective. Also have. Also, the bonding strength is enhanced. The protrusion 63c is mainly for preventing the rotation in the circumferential direction, but also has the effect of preventing the removal in the axial direction. In this embodiment, the plurality of annular bulges 63a, circumferential grooves 63b, and projections 63c are combined, and the fastener 60 is placed in the exterior resin 40 in an extremely stable state. It will be firmly fixed and held.

  The reinforcing resin layer 62 is firmly bonded to the exterior resin 40 at the concavo-convex portion 63 on the outer periphery thereof, and the position / posture occupied by the reinforcing resin layer 62 in the exterior resin 40 becomes sufficiently stable. The to-be-fastened member (nut) 61 embedded in the reinforcing resin layer 62 having sufficiently high position / posture stability is also sufficiently stable in position / posture within the exterior resin 40. It will be expensive. The resin mold type capacitor A is attached to the fixing portion 80 by fastening the fastening member (bolt) 70 inserted through the through hole 80a of the fixing portion 80 to the member (nut) 61 to be fastened. Fix it.

  As described above, since the mechanical strength and stability of embedding the fasteners 60 to the exterior resin 40 are sufficiently high, relative displacement of the fasteners 60 to the exterior resin 40 is strongly prevented. In particular, the reinforcing resin layer 62 integrally bonded to the outer peripheral portion of the fastened member 61 is stronger than the outer resin 40 and has an intermediate strength between the outer resin 40 and the fastened member 61. The difference between the linear expansion coefficient of the reinforcing resin layer 62 and the linear expansion coefficient of the exterior resin 40 is smaller than the difference between the linear expansion coefficients of the fastened member 61 and the exterior resin 40, and the reinforcement resin layer 62 is accompanied by a temperature change. The buffering action against the expansion / contraction stress of the exterior resin 40 is exhibited. Therefore, the interface resin 40 and the reinforcing resin layer 62 are prevented from being peeled off against expansion and contraction of the exterior resin 40 due to temperature change, and as a result, cracks caused by temperature changes in the exterior resin 40 such as epoxy resin. Is prevented from occurring. That is, it is possible to improve the mechanical reliability of the mounting strength of the resin mold type capacitor A with respect to the fixed portion 80.

  Further, in this embodiment, the chamfering is performed on the protruding end edge (ridge) of the annular bulging portion 63a and the protruding end edge (ridge) of the protruding portion 63c integrally coupled to the bulging portion 63a. Processing has been applied. As this chamfering process, the chamfered surface may be an R curved chamfer, the chamfered surface may be a C chamfer on a flat surface, or may be a thread chamfer narrower than the C chamfer. As described above, since the chamfering process is performed on the protruding edge portions (ridge portions) of the bulging portion 63a and the protruding portion 63c, the state of the bonding interface between the exterior resin 40 and the reinforcing resin layer 62 becomes smooth. As a result, interfacial peeling between the exterior resin 40 and the reinforcing resin layer 62 can be more effectively prevented against expansion / contraction of the exterior resin 40 due to temperature changes. That is, it is possible to reliably suppress the occurrence of interface peeling and reliably prevent cracks in the exterior resin 40 such as an epoxy resin.

  Hereinafter, a specific structure of the capacitor unit 30 will be supplemented. The capacitor unit 30 is a metallized film capacitor. The capacitor element 10 generally has the following configuration. That is, a metal film formed by forming a metal vapor deposition electrode on at least one surface of a dielectric film is rolled or laminated in a diametric direction to form a flat columnar body having an oval cross section, and at both axial ends thereof Capacitor element 10 is formed by forming positive electrode / negative electrode metal electrodes 11 and 11 (preferably metal spray electrodes by spraying metal fine particles). Here, the odd-numbered metal vapor deposition electrodes are connected to the positive electrode metal electrode 11 on one axial end side, and the even-numbered metal vapor deposition electrodes are connected to the negative electrode metal electrode 11 on the other axial end side. Positive and negative terminal plates 21 and 21 are mounted on the upper surface of the capacitor element laminate 15. The terminal plates 21 and 21 are electrically insulated from the capacitor element 10. The metal electrodes 11 of the plurality of stacked capacitor elements 10 are joined together in parallel by a connection plate (bus bar) 23 by soldering or the like, and the terminal plate 21 on the upper surface of the laminate 15 is joined to the connection plate 23 by soldering or the like. Has been. A hook-shaped connection terminal portion 22 for connecting an external power supply line is integrally formed at an end portion of the terminal plate 21. The terminal plate 21 with the connection terminal portion 22 and the connection plate 23 constitute the external lead terminal 20, and a pair of such external lead terminals 20 are provided for the positive electrode and the negative electrode. The capacitor unit 30 is formed by connecting the external lead terminals 20 and 20 to the metal electrodes 11 and 11 at both ends in the axial direction of the plurality of capacitor elements 10 as described above. The entire capacitor unit 30 is covered with the exterior resin 40 except for the bowl-shaped connection terminal portions 22 and 22 of the external lead terminals 20 and 20 to form a resin mold type capacitor (metallized film capacitor) A.

  The present invention is a resin mold mold for caseless industrial machines, vehicles and the like in which an exterior resin is molded with a thermosetting resin such as an epoxy resin or a urethane resin which is inferior in mechanical strength to a PPS resin or a PBT resin. Regarding the capacitor, it is useful as a technique for improving the mechanical reliability of the mounting strength with respect to the external fixing portion.

A Resin mold type capacitor 10 Capacitor element 20 External lead terminal 22 Connection terminal part 30 Capacitor unit 40 Exterior resin 60 Fastener 61 Fastened member (nut)
62 Reinforcing resin layer 63 Concavity and convexity 63a Annular bulging part 63b Annular circumferential groove 63c Projecting part 70 Fastening member (bolt)
80 fixed part

Claims (9)

A capacitor unit having one or more capacitor elements and an external lead terminal;
An exterior resin that covers the entire capacitor unit by molding except the connection terminal portion of the external lead terminal; and
It is a member fastened with a fastening member for attaching to an external fixing part, and includes a fastener to be insert-molded in an exposed state on the exterior resin,
The fastened member includes a fastened member that is fastened directly to the fastening member, and a reinforcing resin layer that is stronger than the exterior resin and is integrally coupled to the outer peripheral portion of the fastened member. A resin-molded capacitor, wherein a fastener to be formed of a member and a reinforcing resin layer is insert-molded in the exterior resin.   The resin mold type capacitor according to claim 1, wherein the member to be fastened of the insert-type fastener to be fastened is an insert nut having a fastening action portion formed on a female screw.   The resin-molded capacitor according to claim 1, wherein the reinforcing resin layer has an uneven portion formed on an outer surface portion thereof.   The resin-molded capacitor according to claim 3, wherein the concavo-convex portion is configured such that annular bulge portions and circumferential groove portions around the axis of the fastened member are alternately arranged along the axial direction.   3. The protruding portion according to claim 1, wherein the reinforcing resin layer is integrally formed with a protruding portion that protrudes outward in a radial direction and is prevented from rotating in a circumferential direction around an axis by fitting with the exterior resin. Resin mold type capacitor.   In the reinforcing resin layer, annular bulging portions and circumferential groove portions around the axis of the fastened member are alternately arranged along the axial direction, and project radially outward from each of the annular bulging portions. 3. The resin mold type capacitor according to claim 1, wherein a protrusion that is prevented from rotating in a circumferential direction around an axis by fitting with the exterior resin is integrally formed. 4.   The resin mold type capacitor according to claim 5, wherein a plurality of the protrusions for preventing rotation are spaced apart along the axial direction of the member to be fastened.   The resin-molded capacitor according to any one of claims 1 to 7, wherein the exterior resin is an epoxy resin or a urethane resin.   The resin-molded capacitor according to any one of claims 1 to 8, wherein the reinforcing resin layer is PPS (polyphenylene sulfide) or PBT (polybutylene terephthalate).

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