JP5363892B2 - Capacitor device - Google Patents

Description

  The present invention relates to an assembly structure of a capacitor device that is applied to an induction heating device, an electric resistance welder, and the like, and is intended for a matching capacitor connected to an output circuit of the high-frequency power source (inverter device).

  As is well known, in the induction heating device described above, a matching capacitor is connected to the main circuit conductor (bus bar) wired between the output end of the high frequency power supply and the induction heating coil (work coil). A matching circuit (matching resonance circuit) corresponding to fluctuations in load impedance is configured by the capacitor for work and the work coil so as to increase the efficiency of power supplied to the work coil (for example, see Non-Patent Document 1). ).

  In order to secure a capacity corresponding to the output (power, current) of the induction heating device, a capacitor device in which a plurality of capacitor elements are mounted on a conductor plate and connected in parallel is used as this matching capacitor. Next, the assembly structure of the conventional example is shown in FIGS. In each figure, (a) is a plan view of the assembly structure, (b) is a side sectional view thereof, and 1 is a cylindrical or rectangular tube capacitor element (for example, a film) having external electrodes at both ends. (Capacitors), 2 and 3 are L-shaped conductor plates provided with input / output terminal portions 2a and 3a connected to the bus bars of the main circuit at the conductor ends, respectively, and 4 is arranged in the middle of the terminal portions 2a and 3a. Represents a connecting plate for series connection.

  In the illustrated example, twelve capacitor elements 1 are arranged between the conductor plates 2 and 3 and the U-shaped cross connection plate 4 to form “6 parallel” and “2 series” capacitor units (unit assembly of capacitor elements). This capacitor device is connected to the bus bar of the main circuit (for example, the output circuit of the high frequency power source of the induction heating device) via the terminal portions 2a and 3a of the terminal conductor plates 2 and 3 and used. To do. The terminal portions 2a and 3a are sized to match the bus bar conductor width of the main circuit, and the conductor width of the portion where the capacitor element 1 is mounted is fanned from the terminal portions 2a and 3a corresponding to the number of capacitor elements in parallel. It is expanding.

  In the configuration of FIG. 7, six capacitor elements 1 are mounted in a horizontal row between the conductor plates 2 and 3 and the cross connection plate 4. On the other hand, in the configuration of FIG. 8, the six capacitor elements 1 are arranged in two upper and lower stages to make the apparatus compact.

  In addition to the above structure, with the aim of lowering the inductance of the entire capacitor device, the conductor plates of the input and output terminals are arranged in close proximity to each other, and a capacitor element connected in parallel to this conductor plate is arranged on the conductor plate. Adjacent to each other along the longitudinal direction, and the mutual inductance cancellation between the input and output terminal conductor plates and between the conductor plate and the capacitor element is increased to reduce the inductance value of the entire capacitor device. An assembly structure is also known (see Patent Document 1).

JP-A-9-260180

Atsushi Kurata and two others, "High Frequency Inverter for Induction Heating", Fuji Jiho, Vol.80 No.2 P.135-140 March 2007, published by Fuji Electric Holdings Co., Ltd.

  By the way, in the assembly structure of the conventional device described above, the current flowing through the capacitor elements 1 via the conductor plates 2 and 3 of the input / output terminals becomes unbalanced, and the current concentrates on some capacitor elements. The ripple current flowing through the element may exceed a permissible value, leading to a problem that the life of the element is reduced or destroyed.

  That is, in the configuration of FIGS. 7A and 7B, the current I flowing from the input / output terminal portion to each capacitor element 1 through the conductor plates 2 and 3 and the cross connection plate 4 is a route represented by an arrow in the figure. Follow. Here, when comparing the distances of the routes passing through the capacitor elements 1 starting from the input / output terminal portions 2a and 3a, it is clear that the outer side of the conductor plate is larger than the capacitor elements 1 arranged on the center side of the conductor plates 2 and 3. The distance of the route that passes through the capacitor elements arranged on both sides is large. On the other hand, since the inductance value of the conductor along each route is proportional to the distance of the route, the current I is caused by the difference in the inductance value in the central portion of the conductor plates 2 and 3 (region P indicated by the dotted line in the figure). ) Flow in a concentrated manner on the capacitor elements 1 arranged in a row. Such a current concentration phenomenon becomes prominent particularly when a high-frequency current is passed through the main circuit.

  FIG. 7C is a diagram showing a constant circuit in which the above-described current route is modeled. L2, L3, and L4 shown in the figure are the capacitor elements 1 of the conductor plates 2 and 3 and the transition connection plate 4, respectively. Represents the conductor inductance along the route leading to, and the shading represents the magnitude of the inductance value (the darker the shading, the larger the inductance value).

  8A and 8B, the current flowing through each capacitor element 1 mounted between the L-shaped conductor plates 2 and 3 and the U-shaped cross-connecting plate 4 is divided into two upper and lower stages. As for the routes, when the distances of the routes through the capacitor elements starting from the input / output terminal portions 2a and 3a of the conductor plates 2 and 3 are compared in the same manner as described above, the route passing through the capacitor elements on the upper stage side compared to the lower stage side. , And the current concentrates on the capacitor elements arranged on the lower side due to the difference in the length of the current path.

  Further, in the assembly structure disclosed in the above-mentioned Patent Document 1, the distance of the current path passing through the capacitor elements arranged in parallel in the longitudinal direction of the input / output terminal conductor starting from the terminal portion of the input / output terminal conductor, Therefore, since the inductances of the conductors are different, current tends to concentrate on the capacitor element connected to the region close to the terminal portion due to the difference in inductance.

  The present invention has been made in view of the above points, and an object of the present invention is to reduce the unbalance of the current flowing through each capacitor element in a capacitor element that is mounted on a conductor plate connected to an input / output terminal and connected in series and in parallel. Another object of the present invention is to provide a capacitor device having an improved assembly structure so as to prevent current from concentrating on some capacitor elements.

In order to achieve the above object, according to the present invention, a capacitor device in which a plurality of capacitor elements each having external electrodes on both upper and lower ends are mounted on a conductor plate and the capacitor elements are connected directly and in parallel. Because
The number of capacitor elements corresponding to the number in parallel is divided into two parallel groups, the capacitor elements are divided into left and right columns, and the lower electrode is in contact with the main conductor plate and mounted in parallel, with the main conductor plate sandwiched in the center. in the series conductor plate closely placed on the left and right sides, a capacitor element connected in series with the capacitor element of the right and left columns mounted in the series conductor plate on each of the main body plate, mounted in contact with the terminals of the lower end The capacitor assembly is formed by disposing a connecting plate in contact with the upper terminal of each capacitor across the capacitor elements mounted on the series conductor plate and the left and right capacitor elements mounted on the main conductor plate. configure unit, one terminal of the input and output terminals drawn out from one end of the main body plate, the other terminal portion, the drawer from the side opposite the terminal portion of the main body plate, these input and output Connected to the main circuit via the terminal portion (claim 1).

In addition, according to the present invention, the capacitor device can be configured in the following manner on the basis of the capacitor aggregate unit configured as described above.
(1) One terminal portion of the input / output terminal described above is provided at one end in the longitudinal direction of the main conductor plate, and the other terminal portion is arranged on the outermost side among the serial conductor plates arranged on the left and right sides of the main conductor plate. It is drawn out to the opposite side of the terminal portion of the main conductor plate across the series conductor plates (Claim 2).
(2) Two sets of capacitor aggregate units are placed close to each other with the back surfaces of the main conductor plate and series conductor plate facing each other, and each set of aggregate units is connected to the main via the input / output terminal section provided on the unit. It is used by being connected in series with the forward conductor and the return conductor of the circuit.
(3) Two sets of capacitor assembly units are placed close to each other with the back surfaces of the main conductor plate and the series conductor plate facing each other, and a connection plate is interposed between the series conductor plates arranged on the outermost side of each set of assembly units. The units are connected to each other and then used in parallel with the main circuit via input / output terminal portions provided on the main conductor plate of each set of capacitor assembly units.
(4) After dividing the series conductor plates arranged on the left and right sides of the main conductor plate into a plurality of conductor plates, a series capacitor element is mounted on each conductor plate, and between adjacent conductor plates A connecting plate is disposed between the capacitor elements mounted on the conductor plate across the gap (Claim 5).

The above-described configuration of the present invention provides the following effects.
(1) Current flowing through each capacitor element while suppressing variations in conductor inductance corresponding to the route of the current path passing through each capacitor element mounted on the main conductor plate and series conductor plate starting from the input / output terminal portion of the capacitor assembly unit This improves the balance and improves the reliability by preventing the trouble that current flows through some capacitor elements.
(2) Further, according to the configuration of claims 3 and 4, two capacitor aggregate units are arranged close to each other and connected to the main circuit via an input / output terminal portion provided in the aggregate unit. For example, it is possible to reduce the inductance of the entire capacitor device by increasing the amount of cancellation of the conductor inductance between the conductor plates of the capacitor assembly units that are close to each other.
(3) Furthermore, the series conductor plates arranged on the left and right sides of the main conductor plate are divided into a plurality of conductor plates, and a series capacitor element is mounted on each conductor plate, and straddles between adjacent conductor plates. According to the structure of claim 5 in which the connecting plate is disposed between the capacitor elements mounted on the conductor plate, the number of capacitor elements connected in series can be increased or decreased in accordance with the number of divisions of the conductor plate. .

It is a figure showing the capacitor | condenser apparatus by 1st Example of this invention, (a) is a perspective view of an assembly structure, (b) is a front view of (a), (c) is an equivalent circuit schematic. FIG. 2 is a constant circuit diagram corresponding to FIG. It is a circuit diagram showing the state which connected the capacitor | condenser apparatus of FIG. 1 to the output circuit of the induction heating apparatus as a matching capacitor. It is a figure showing the capacitor | condenser apparatus by 2nd Example of this invention, (a) is a perspective view of an assembly structure, (b) is a front view of (a), (c) is connected to the output circuit of the induction heating apparatus. It is an equivalent circuit diagram of a capacitor device. It is a schematic plan view of the application Example which changed the transition connection board in FIG. FIG. 2 is a configuration diagram of an application example in which the number of series conductor plates in FIG. 1 is changed, (a) is a schematic plan view showing an arrangement of conductor plates and capacitor elements, and (b) is an equivalent circuit diagram thereof. It is a block diagram of the prior art example of a capacitor | condenser apparatus, (a) is a top view, (b) is side sectional drawing, (c) It is a constant circuit diagram. It is a block diagram of the prior art example different from FIG. 7, (a) is a top view, (b) is side sectional drawing.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a capacitor device according to the present invention will be described below based on the examples shown in FIGS.

  First, the assembly structure of Embodiment 1 corresponding to claims 1, 2, and 4 of the present invention is shown in FIGS. In this embodiment, two capacitor assembly units A and B having the same assembly structure are arranged close to each other back to back to constitute a capacitor device. An equivalent circuit of this capacitor device is shown in FIG.

  Here, in the capacitor assembly units A and B, 12 capacitor elements 1 are distributed and mounted on the main conductor plate 5 and the series conductor plate 6 as described below, as in the conventional apparatus shown in FIGS. The capacitor elements are connected in series by the connecting plate 7 to form “6-parallel” and “2-series” capacitor circuits. Next, the detailed structure will be described.

  That is, the main conductor plate 5 is a strip-shaped copper plate that is long in the front-rear direction, and a terminal portion 5a of an input / output terminal is formed at one end in the longitudinal direction. (6) capacitor elements 1 are divided into two groups of three, and the capacitor elements 1 of each group are divided into left and right rows and mounted side by side on the main conductor plate 5. Soldered to the conductor plate. Further, two series conductor plates 6 are arranged in close proximity with the main conductor plate 5 sandwiched in the center on the left and right sides, and three series capacitor elements 1 are arranged on each series conductor plate 6. They are mounted side by side in the front-rear direction.

  And between the three capacitor elements 1 in the left column mounted on the main conductor plate 5 and the three capacitor elements 1 mounted in the left series conductor plate 6 and in the right column 3 mounted on the main conductor plate 5. A single jumper connection plate 7 is disposed between the capacitor elements 1 and the three capacitor elements 1 mounted on the right series conductor plate 6. Bonded to the electrode of the capacitor element 1. Further, an input / output terminal plate which is formed of a U-shaped conductor at the end opposite to the terminal portion 5a of the main conductor plate 5 and straddling between the series conductor plates 6 arranged on the left and right sides of the main conductor plate 5. The capacitor assembly units A and B are constructed by joining 8 together.

  Here, in contrast to the constant circuit of the conventional example shown in FIG. 7C, the constant circuit of the capacitor aggregate units A and B configured as shown in FIGS. 1A and 1B is shown in FIG. become. In FIG. 2, L5, L6, and L7 are conductor inductances of the main conductor plate 5, the series conductor plate 6, and the crossover connection plate 7 corresponding to the route (current path) passing through the capacitor elements 1 connected in series and in parallel, respectively. Represents. In this constant circuit, the total of the conductor inductances (L5 + L6 + L7) along each route starting from the input / output terminal portions 5a, 8 is constant regardless of the route, and as a result, the conventional circuit shown in FIGS. It is possible to solve the problem that current concentrates on some capacitor elements 1 due to current imbalance as described in the example.

  Further, as described above, a capacitor device (capacitor assembly unit A and B are arranged in close proximity to each other with the back surfaces of the main conductor plate 5 and the series conductor plate 6 (opposite the mounting surface of the capacitor element 1) facing each other (see FIG. 1) is applied to, for example, an induction heating device, and a bar conductor wired between an output end of a high frequency power source (inverter device) 9 of the induction heating device and an induction heating coil (work coil) 10 as shown in FIG. The following effects can also be obtained by configuring the matching circuit by connecting the forward path and the backward path in series. That is, in the circuit of FIG. 3, currents flow in the opposite directions to the collective unit A and the collective unit B, so the conductor inductance is canceled between the collective units A and B due to the proximity effect between the conductors, and the inductance of the entire capacitor device Can be reduced.

  In this embodiment, the two capacitor assembly units A and B are combined so as to be closely arranged and connected to the circuit of the induction heating device. However, the arrangement and application are not limited to this, for example, a capacitor The collective units A and B may be individually used separately. Also, the number of capacitor elements 1 connected in parallel does not necessarily need to be divided into equal parts on the left and right sides of the main conductor plate 5 and mounted in half as in the illustrated embodiment. The number of capacitor elements 1 to be distributed and mounted on the left and right rows of the main conductor plate 5 may be different.

  Next, a second embodiment according to the fourth aspect of the present invention will be described with reference to FIGS. In this embodiment, the capacitor element 1 is mounted on the main conductor plate 5 and the series conductor plate 6 in the same manner as in the first embodiment, and the capacitor elements 1 are connected to each other by the crossover connection plate 7. Unit connection plates 11 (same as the series conductors 5), the capacitor assembly units A and B of the first and second units are arranged close to each other back to back, and the assembly units A and B of each set are interposed between the series conductor plates 6. The capacitor device is constructed by interconnecting the conductor pieces with a length). Then, the capacitor device of this embodiment is used as a matching capacitor for an induction heating device, for example, connected in parallel to the output circuit of the high frequency power supply circuit 9 as shown in FIG.

  In this embodiment as well, as described in the first embodiment, it is possible to reduce the unbalance of the current flowing through each capacitor element 1 to prevent the current from being concentrated on some capacitor elements. By arranging the capacitor assembly units A and B close to each other back to back, the inductance of the capacitor device can be reduced.

  Next, FIG. 5 shows an application example in which the connecting plate 7 is changed in the assembly structure of the capacitor assembly units A and B described in the first and second embodiments. That is, in the assembly structure shown in FIG. 1 and FIG. 4, the cross connection plate 7 disposed on the three capacitor elements 1 across the main conductor plate 5 and the series conductor plate 6 is provided as a single plate. However, as shown by a broken line in FIG. 5, it is also possible to individually connect the capacitor elements 1 that are connected in series by dividing into a plurality (three) of the transition connection plates 7 a to 7 c.

  Next, in each of the embodiments described above, the number and arrangement of the series conductors 6 arranged close to the left and right sides of the main conductor plate 5 are changed to change the number of series connection of the capacitor elements. An embodiment corresponding to the above will be described with reference to FIGS.

  That is, in the first and second embodiments, the number of series of capacitor elements 1 is “2”, and the two series conductors 6 are distributed and arranged on the left and right sides of the main conductor plate 5. On the other hand, in the embodiment of FIG. 6, in order to change the number of capacitor elements 1 connected in series from “2” to “4”, the main conductor plate 5 and the series conductor plates 6b arranged on the left and right sides thereof are arranged. A new series conductor plate 6a is interposed in between, so that the total number of series conductor plates is four, and six capacitor elements 1 are mounted on the newly added series conductor plate 6a in two left and right rows. Thus, the capacitor elements 1 are connected in series via the cross connection plate 7 disposed between the main conductor plate 5 / the series conductor plate 6a / the series conductor plate 6b. Thereby, an equivalent circuit of the capacitor device is as shown in FIG.

  In the embodiment of FIG. 6, the total number of series connection plates is 4 and the number of series of capacitor elements 1 is “4”. However, by changing the number of series conductor plates further, the same as in the previous embodiment. The number of capacitor elements in series can be increased or decreased according to the number of series conductor plates while suppressing unbalance and local concentration of currents flowing through the capacitor elements.

DESCRIPTION OF SYMBOLS 1 Capacitor element 5 Main conductor plate 5a Input / output terminal part of main conductor plate 6, 6a, 6b Series conductor plate 7, 7a, 7b, 7c Cross connection plate 8 Input / output terminal plate of series conductor plate 9 Connection between capacitor assembly units Plate A, B Capacitor assembly unit

Claims (5)

A capacitor device in which a plurality of capacitor elements each having external electrodes on both upper and lower ends are mounted on a conductor plate, and the capacitor elements are connected directly and in parallel,
The number of capacitor elements corresponding to the number in parallel is divided into two parallel groups, the capacitor elements are divided into left and right columns, and the lower electrode is in contact with the main conductor plate and mounted in parallel, with the main conductor plate sandwiched in the center. in the series conductor plate closely placed on the left and right sides, a capacitor element connected in series with the capacitor element of the right and left columns mounted in the series conductor plate on each of the main body plate, mounted in contact with the terminals of the lower end The capacitor assembly is formed by disposing a connecting plate in contact with the upper terminal of each capacitor across the capacitor elements mounted on the series conductor plate and the left and right capacitor elements mounted on the main conductor plate. configure unit, one terminal of the input and output terminals drawn out from one end of the main body plate, the other terminal portion, the drawer from the side opposite the terminal portion of the main body plate, these input and output Capacitor and wherein the connecting to the main circuit through the terminal part.   2. The capacitor device according to claim 1, wherein one terminal portion of the input / output terminal is provided at one end in the longitudinal direction of the main conductor plate, and the other terminal portion is a series conductor plate disposed on the left and right sides of the main conductor plate. The capacitor | condenser apparatus characterized by pulling out on the opposite side to the terminal part of the main conductor board across between the serial conductor boards arranged in the outermost among them.   3. The capacitor device according to claim 1 or 2, wherein two sets of capacitor aggregate units are arranged close to each other with the back surfaces of the main conductor plate and the series conductor plate facing each other, and each set of capacitor aggregate units is set to the aggregate unit. A capacitor device, wherein the capacitor device is used by being connected in series to the forward conductor and the return conductor of the main circuit via the input / output terminal portion provided in the circuit.   2. The capacitor device according to claim 1, wherein two sets of capacitor assembly units are arranged close to each other back to back with the main conductor plate and the back surface of the series conductor plate facing each other, and are arranged on the outermost side of each set of capacitor assembly units. The unit connecting plates are inserted between the plates to connect the collective units, and then connected in parallel to the main circuit via the input / output terminal portions provided on the main conductor plate of each set of capacitor collective units. Capacitor device.   5. The capacitor device according to claim 1, wherein a series conductor plate arranged on the left and right sides of the main conductor plate is divided into a plurality of conductor plates, and a capacitor element in series with each conductor plate. And a connecting plate disposed between the capacitor elements mounted on the conductor plate across the adjacent conductor plates.

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