JP5233832B2 - Case mold type capacitor and manufacturing method thereof - Google Patents

Description

  INDUSTRIAL APPLICABILITY The present invention is used in various electronic devices, electric devices, industrial devices, automobiles, etc., and in particular, a metallized film capacitor that is optimal for smoothing, filtering, and snubbing of an inverter circuit for driving a motor of a hybrid vehicle is contained in a case. The present invention relates to a resin-molded case mold type capacitor and a method for manufacturing the same.

  In recent years, from the viewpoint of environmental protection, all electric devices are controlled by inverter circuits, and energy saving and high efficiency are being promoted. In particular, in the automobile industry, development using technologies that are friendly to the global environment has become active, such as the introduction of hybrid vehicles (hereinafter referred to as HEVs) that run on electric motors and engines.

  Such a HEV vehicle has a configuration in which an engine and an electric motor are used together, so that the number of components increases, and it is required to increase the dimensional accuracy of each component and reduce the number of assembly steps.

  FIG. 4A is a perspective view showing the configuration of this type of conventional case mold type capacitor, FIG. 4B is a plan view thereof, and FIG. 4C is a diagram of a conventional method for manufacturing a case mold type capacitor. It is the perspective view which showed the terminal positioning method.

  4 (a) and 4 (b), reference numeral 31 denotes a capacitor element. The capacitor element 31 is a metallized film in which a metal vapor-deposited electrode is formed on one or both sides of a dielectric film, and a pair of metal vapor-deposited electrodes is a dielectric. It winds so that it may oppose through a film, and it has comprised P pole and N pole in the wound both end surfaces, respectively.

  Reference numeral 32 denotes a P-pole bus bar. The P-pole bus bar 32 is provided on the main body portion 32a, a P-pole terminal 32b for external connection integrally formed by bending one end of the main body portion 32a, and the P-pole terminal 32b. The connection hole 32c is formed.

  And the main-body part 32a of the P pole bus bar 32 is joined to the P pole formed on one end face of each capacitor element 31 in a state where a plurality of the capacitor elements 31 are arranged in close contact with each other.

  The P-pole terminal 32b is pulled out above the capacitor element 31 and is exposed from a case 34 described later.

  33 is an N-pole bus bar, and this N-pole bus bar 33 is also composed of a main body portion 33a and an N-pole terminal 33b having a connection hole 33c, like the P-pole bus bar 32, and the main body portion 33a is connected to the other end face of the capacitor element. A plurality of capacitor elements 31 are connected in parallel by joining to the N poles formed on the N pole, and the N pole terminal 33 b is exposed from the case 34.

  Reference numeral 34 denotes a resin case having an open top surface. A plurality of capacitor elements 31 connected in parallel by the P-pole bus bar 32 and the N-pole bus bar 33 are accommodated in the case 34, and a P-pole terminal 32b. And the N-pole terminal 33b are exposed from the upper end surface of the case 34, respectively.

  Reference numeral 34a denotes an attachment portion for attachment to an external device integrally provided on the periphery of the case 34, and 34b denotes an attachment hole provided in the attachment portion 34a.

  The case 34 is filled with an epoxy resin, and a plurality of capacitor elements 31 connected in parallel by the P-pole bus bar 32 and the N-pole bus bar 33 are resin-molded in the case 34 with the epoxy resin.

  In such a conventional case mold type capacitor, the P-pole terminal 32b and the N-pole terminal 33b are positioned by the method shown in FIG. In FIG. 4C, using the casting jig 37, the mounting hole 34b of the mounting portion 34a provided on the periphery of the case 34, the P-pole terminal 32b of the P-pole bus bar 32, the N-pole bus bar 33, and the N extreme The connection holes 32c and 33c provided in the child 33b are inserted into the positioning pins 37a provided in the casting jig 37 for positioning, and the clamp lever 37b is operated and fixed forcibly.

  In this state, the epoxy resin is injected into the case 34 and cured, and then the clamp lever 37b is operated to release the fixed state, and the case 34 is removed from the casting jig 37. .

  In this way, even if the shrinkage caused by the hardening of the epoxy resin injected into the case 34 occurs, the P-pole bus bar 32, the N-pole bus bar 33, and the capacitor element 31 cannot move, so that no positional deviation occurs. The case mold type capacitor maintaining high dimensional accuracy can be manufactured stably.

JP 2006-216756 A

  However, in the case mold type capacitor used in the inverter circuit for driving the motor of the hybrid vehicle in particular, the positional accuracy of the external connection terminal of the bus bar is, for example, larger than the case size of 200 to 300 mm. Is required to have a high level of accuracy such as 1 mm or less, and further 0.1 mm or less.

  Furthermore, in recent years, there are bus bar shapes that are complex, such as a combination of straight and inclined parts, and those that have a long distance from the exposed location from the filled resin to the location where the external device is connected. In the case of deformation, the conventional positioning method cannot correct the positional deviation of the bus bar, and it is difficult to ensure the positional accuracy of the external connection terminals.

  In addition, since this connection hole is mechanically and electrically connected to external equipment using bolts, etc., there are many cases where the tolerance is relatively moderate. With this connection hole alone, sufficient accuracy of the terminal position is ensured. Was in a difficult situation.

  The present invention solves such a conventional problem, and provides a case mold type capacitor capable of accurately positioning a bus bar terminal with a simple configuration even if the shape of the bus bar is elongated or complicated, and a method for manufacturing the same. It is intended to provide.

In order to achieve the above object, a case mold type capacitor of the present invention comprises a capacitor element having both end faces, a pair of bus bars connected to both end faces of the capacitor element, and a case for accommodating the capacitor element together with a filling resin. In the case mold type capacitor having, the bus bar has an external connection terminal portion that is exposed from the filling resin on the opposite side connected to the capacitor element, and the external connection terminal portion is fastened to be fastened with an external device. possess a hole, the positioning round hole of smaller shape than the fastening hole, the positioning of the pair of bus bars relative to the case in the assembly process, fixed to a jig assembled casing, assembling jig into the positioning round hole and the fastening hole It is performed by inserting the positioning pin of the tool .

  Further, after the pin is inserted and fixed in two places of the fastening hole and the positioning round hole, a filling method is performed to inject and cure the filling resin, thereby manufacturing a case mold type capacitor having high bus bar position accuracy. .

  In the case mold type capacitor according to the present invention, a fastening hole and a positioning round hole having a shape smaller than the fastening hole are provided in the external connection terminal portion of the bus bar, and positioning is performed using the fastening hole and the positioning round hole. Thus, the external connection terminal portion can be positioned very easily. Even if the bus bar has a complicated shape or is long, the position of the bus bar can be adjusted by adjusting the position of the round hole for positioning and optimizing the distance between the fastening hole and the round hole for positioning. Therefore, it is possible to further increase the positional accuracy of the external connection terminal portion.

The disassembled perspective view which shows the component of the case mold type capacitor | condenser in embodiment of this invention (A) The perspective view after the assembly, (b) The front view for showing the projection part for external equipment mounting provided in the case (A) The perspective view for demonstrating the terminal positioning method in the manufacturing method of the case mold type capacitor | condenser in embodiment of this invention, (b) The side view (A) The perspective view which shows the structure of the conventional case mold type capacitor, (b) The same top view, (c) The perspective view which showed the terminal positioning method in the manufacturing method of the conventional case mold type capacitor

  A case mold type capacitor and a manufacturing method thereof according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an exploded perspective view showing components of a case mold type capacitor according to an embodiment of the present invention, and FIG. 2A is a perspective view after assembling the components shown in FIG. Filling resin (not shown) is filled up to the vicinity.

  FIG. 2B is a front view showing a structure in which a protrusion for assembling an external device (not shown) is provided on the case leg of the case mold type capacitor of FIG. By inserting and assembling into a fitting hole (not shown) provided in the device, it can be easily assembled when mounting the case mold type capacitor to the external device, and the positional relationship with the external device is accurate. It is for assembly.

  In FIG. 1, reference numeral 1 denotes a metallized film capacitor element (hereinafter referred to as capacitor element 1) having an oval cross-sectional shape. The capacitor element 1 is formed by winding a metallized film (not shown) in which a metal vapor-deposited electrode is formed on one or both sides of a dielectric film such as a polypropylene film so that the metal vapor-deposited electrode faces the dielectric film. Thereafter, a flat shape with an oval cross-section is formed by pressing, and a pair of extraction electrodes including a P-electrode 1a and an N-electrode 1b are provided on both end surfaces by metal spraying of zinc or the like.

  Reference numeral 2 denotes a P pole bus bar connected to a P pole electrode 1a which is one take-out electrode of the capacitor element 1. The P pole bus bar 2 is formed by punching a conductive metal plate such as a copper plate and bending it. Has been.

  One end (one end) of the P-pole bus bar 2 is provided with an external connection terminal portion 2b. The external connection terminal portion 2b has a fastening hole 2c for connecting to an external device, and a shape smaller than the fastening hole 2c. Thus, a positioning round hole 2d with high dimensional accuracy (small dimensional tolerance) is provided, and a connecting portion 2a connected to the P-electrode 1a is provided at the other end (referred to as the other end). It has been.

  In addition, the connection part 2a of the P pole bus bar 2 connected with the P pole electrode 1a of the capacitor | condenser element 1 is formed in multiple places so that it may branch from a P pole bus bar, and is connected with the P pole electrode 1a by soldering.

  Reference numeral 3 denotes an N pole bus bar connected to the N pole electrode 1b which is the other extraction electrode of the capacitor element 1. The N pole bus bar 3 is punched out of a metal plate such as a copper plate and bent in the same manner as the P pole bus bar 2 described above. It is a thing. The other end is provided with a connecting portion 3a (not shown) connected to the N-electrode 1b, and one end is provided with an external connecting terminal portion 3b. The external connecting terminal portion 3b is connected to an external device. A fastening hole 3c to be connected and a positioning round hole 3d having a shape smaller than the fastening hole 3c and high dimensional accuracy (small dimensional tolerance) are provided.

  4 is a case made of resin such as polyphenylene sulfide, and both ends of the case 4 are provided with leg portions 4a for attachment to an external device. A cylindrical metal ring 4b is inserted into the leg portion 4a. It is fastened with external equipment by bolts.

  This cylindrical metal ring 4b eliminates loosening when the bolts are mounted on the vehicle, and makes the mounting reliability of the case 4 resistant to external vibrations and mechanical stress caused by thermal expansion and contraction differences with external devices. It is provided to improve.

  In this case 4, the element unit 5 in which the P-pole bus bar 2 and the N-pole bus bar 3 are connected to the capacitor element 1 is housed, and the metal ring 4 b of the leg portion 4 a of the case 4, the fastening hole 2 c of the P-pole bus bar 2, The positioning round hole 2d, the fastening hole 3c of the N pole bus bar 3 and the positioning round hole 3d are assembled to the assembly jig 6, filled with an insulating mold resin, and hardened. A case mold type capacitor is produced.

  A manufacturing method of the case mold type capacitor thus manufactured will be described in detail below with reference to FIG.

  First, the connection portion 2a of the P-pole bus bar 2 is connected to the P-pole electrode 1a of the capacitor element 1 by soldering, and the connection 3a (not shown) of the N-pole bus bar 3 is soldered to the N-pole electrode 1b of the capacitor element 1. Then, the element unit 5 is manufactured.

  Here, with respect to the mounting position of the P pole bus bar 2 and the N pole bus bar 3 with respect to the capacitor element 1, while fixing the capacitor element 1, the P pole bus bar 2 and the N pole bus bar 3 are fixed by soldering, At this time, the position accuracy can be further increased by fixing and soldering using the fastening holes 2c and 3c and the positioning round holes 2d and 3d.

  Next, the metal rings 4 b and 4 b provided on the legs 4 a and 4 a at both ends of the case 4 are assembled to the pins 6 a and 6 a which are the first positioning pins of the assembly jig 6, and the case 4 is attached to the assembly jig 6. Fix and fix the reference position of case 4.

  The element unit 5 in which the capacitor element 1, the P-pole bus bar 2 and the N-pole bus bar 3 are connected is accommodated in the case 4, and the pin 7 a which is the second positioning pin of the assembly jig 6 is inserted into the fastening hole 2 c of the P-pole bus bar 2. And a pin 7b, which is the third positioning pin of the assembly jig 6, is inserted into the positioning round hole 2d of the P-pole bus bar 2.

  As a result, the P-pole bus bar 2 is fixed to the case 4 with high accuracy, and the P-pole bus bar 2 is fixed by the two pins 7a and 7b, so that no positional deviation (swing) occurs in the surface direction. Even if the P-pole bus bar 2 is a long bus bar with a long length protruding from the case 4 or a complex irregular shaped bus bar, the positional accuracy of the fastening hole 2c with respect to the case 4 can be set high.

  Similarly to the P-pole bus bar 2, the N-pole bus bar 3 is also provided with a pin 7c, which is the second positioning pin of the assembly jig 6, and a pin 7d, which is the third positioning pin, respectively, as a fastening hole 3c and a positioning round hole 3d. The N-pole bus bar 3 is fixed to the case 4 with high positional accuracy.

  Here, since the fastening holes 2c (3c) are mechanically and electrically connected to external devices by bolts or the like, there are many cases where they have relatively moderate tolerances, and other bus bars such as external devices In order to increase the contact area between the bus bars, an irregular shape such as an octagon is also used.

  Therefore, it is difficult to ensure sufficient positional accuracy of the bus bar only with this fastening hole, but the positioning hole 2d (3d) with high dimensional accuracy (small dimensional tolerance) is the main positioning means, and the fastening hole 2c (3c) is the bus bar. Positioning can be performed as an auxiliary role for suppressing only the rotation direction.

  Therefore, the pin 7a (7c) inserted through the fastening hole 2c (3c) does not need to have the same shape as the fastening hole 2c (3c). For example, when the fastening hole 2c (3c) is an octagon, The shape of a round bar inscribed in an octagonal hole may be smaller.

  Even if the P-pole bus bar 2 (N-pole bus bar 3) is deformed when the element unit 5 is assembled by fixing the two positions of the positioning round hole 2d (3d) and the fastening hole 2c (3c). The terminal position can be corrected to ensure accuracy.

  The reason why the round hole for positioning 2d (3d) is a round hole is that it is suitable for processing with high dimensional accuracy, and the pin can be inserted with high accuracy by making the positioning pin described later into a round bar shape. Because.

  The positioning round hole 2d (3d) needs to be smaller in shape than the fastening hole 2c (3c), and if the shape (diameter) of the positioning round hole 2d (3d) is large, a large current flows. This is because the resistance value of the P-pole bus bar 2 (N-pole bus bar 3) increases, causing heat generation, which is not preferable.

  The shape of the positioning round hole 2d (3d) preferably has a diameter equal to or larger than the thickness (about 0.5 to 1.0 mm) of the P-pole bus bar 2 (N-pole bus bar 3) from the viewpoint of processing accuracy. .

  From the above, the diameter of the positioning circular hole 2d (3d) is preferably about 1 to 5 times the thickness when the thickness of the P pole bus bar 2 (N pole bus bar 3) is used as a reference.

  The pins 7a (7c) and 7b (7d) are moved in the direction of the arrow shown in the side view of FIG. 3B by an unillustrated built-in spring or the like, so that the fastening holes 2c (3c) and the positioning round holes are obtained. Insertion and release into 2d (3d) can be performed easily.

  As described above, the metal rings 4b, 4b provided on the legs 4a, 4a at both ends of the case 4 are assembled to the pins 6a, 6a to fix the case 4, and the fastening holes 2c of the P pole bus bar 2 and the N pole bus bar 3 are fixed. 3c and positioning round holes 2d and 3d are inserted and fixed in pins 7a, 7b, 7c and 7d, respectively, and the case 4 is filled with a filling resin and cured by heating.

  After the pins 7a, 7b, 7c and 7d are released after the filling resin is cured, a case mold type capacitor having high dimensional accuracy is manufactured by removing the case from the pins 6a and 6a.

  In the present embodiment, the case of one capacitor element 1 is shown. However, the present invention is not limited to this, and a plurality of capacitor elements 1 may be used. In this case, a plurality of capacitor elements 1 are connected to each other by a P-pole bus bar 2 and an N-pole bus bar 3 extending from the connecting portions 2a and 2b.

  In the present embodiment, the pin 7b, 7d is a round bar having a uniform diameter. However, the present invention is not limited to this, and the pin 7b, 7d is a positioning round hole 2d, 3d. The diameter of the portion inserted through the head may be continuously narrowed toward the tip (toward the left in FIG. 3B).

  By continuously reducing the diameter of the portion to be inserted toward the tip, the pins 7b and 7d can be easily inserted, and the pins 7b and 7d are fitted in the positioning round holes 2d and 3d. Since the bus bar can be fixed, the positional accuracy can be further increased.

  The case mold type capacitor according to the present invention is provided with a positioning round hole near the bus bar fastening hole, assembled by inserting two positioning pins into both the fastening hole and the positioning round hole, and fixed by curing the filling resin. With such an extremely simple configuration, the dimensional system of the fastening hole position can be improved. This improved position accuracy facilitates assembly to external equipment and has the effect of reducing the number of assembly steps because there is no need for position correction. Especially, a case mold type used for hybrid vehicles. Useful for capacitors and the like.

DESCRIPTION OF SYMBOLS 1 Capacitor element 1a P pole electrode 1b N pole electrode 2 P pole bus bar 2a Connection part 2b External connection terminal part 2c Fastening hole 2d Round hole for positioning 3 N pole bus bar 3b External connection terminal part 3c Fastening hole 3d Round hole for positioning 4 Case 4a Leg 4b Metal ring 5 Element unit 6 Assembly jig 6a, 7a, 7b, 7c, 7d Pin

Claims (4)

A capacitor element having both end faces;
A pair of bus bars connected to both end faces of the capacitor element;
In a case mold type capacitor having a case for accommodating the capacitor element together with a filling resin,
The bus bar has an external connection terminal portion exposed from the filling resin on the opposite side connected to the capacitor element,
The external connection terminal portion possess the positioning round hole of smaller shape than the fastening hole and the fastening hole for fastening with an external device,
The positioning of the pair of bus bars with respect to the case in the assembly process is performed by fixing the case to an assembly jig and inserting a positioning pin of the assembly jig into the fastening hole and the positioning round hole. A case mold type capacitor. The case-molded capacitor according to claim 1, wherein the case has a leg portion provided with a mounting hole for mounting to the external device, and a protrusion for mounting the external device is provided in the vicinity of the mounting hole. The case mold type capacitor according to claim 1, wherein there are a plurality of capacitor elements. A step of connecting the other end of a pair of bus bars having an external connection terminal portion at one end to both end faces of the capacitor element; a step of housing the capacitor element and the bus bar in a case; and a mounting hole provided in the case A step of fixing the case by inserting a first positioning pin provided in the casting jig, and a second step provided in the casting jig in a fastening hole provided in the external connection terminal portion of the bus bar. And a step of inserting and fixing a third positioning pin provided in the casting jig into the positioning round hole, and then filling the case with a filling resin and curing And a step of releasing the first, second and third positioning pins and removing the case from the casting jig after the filling resin is cured. Law.

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