JPH10106879A - Block capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve noise attenuation characteristics as a noise filter, and simplify mounting work, by improving frequency characteristics. SOLUTION: A block capacitor constituting a noise filter is provided with. the following; three capacitors Cy1-Cy3, a case 10 capable of accommodating the three capacitors, and a metal electrode terminal plate 14 fixed so as to close a lower part aperture of the case 10. Three lead wires La1-La3 led out from one side electrodes of the three capacitors are led out from the upper part of the case 10. Three lead wires Lb1-Lb3 led out from the other side electrodes of the three capacitors are electrically connected with the electrode terminal plate 14. When the block capacitor is mounted on an apparatus, the electrode terminal plate 14 is directly brought into contact with the cabinet, as GND, of the apparatus. In this state, screws are inserted into screw insertion holes 18 of a fixing segment 16, and screwed to the apparatus.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a block capacitor for an AC power supply obtained by blocking a plurality of capacitors, and for example, a block used for noise suppression of a power supply line of a three-phase power control device such as an inverter. Related to capacitors. Note that a device simply referred to as a device refers to all devices to which electricity is supplied, and includes electronic devices, electric devices, a control panel, a wiring board, and the like.

[0002]

2. Description of the Related Art In recent years, attention has been paid to high power use efficiency, and a DC power generation circuit using a switching regulator or an inverter circuit for driving a motor or the like has been frequently used.

[0003] Since these circuits include a switching circuit, they can be a noise source that generates conduction noise and radiation noise. For example, when the noise generation source is directly connected to an AC power supply via an AC cord, noise generated in the switching circuit (noise generation source) returns to the AC power supply side via the AC cord as conduction noise. Radiation noise from the AC code also occurs. The conduction noise affects other electric devices (electronic devices) connected to the AC power supply, and the radiated noise is
(Audio Visual) Affects equipment.

[0004] Therefore, the conducted noise and radiated noise generated from the noise source are referred to as so-called EMI in various standards such as the VCCI standard, the CISPR standard, and the FCC standard.
(Electromagnetic Interference) is subject to regulation, and it is required to suppress it to a level below a predetermined level.

In order to suppress this noise, various noise filters have been developed and put into practical use. As a noise filter, for example, a block capacitor for an AC power supply obtained by blocking a plurality of capacitors is known.

A conventional block capacitor is, for example, shown in FIG.
As shown in FIG. 7 and FIG.
Cy3 and the three capacitors Cy1 to Cy3 can be accommodated therein, and three lead wires L1 to L3 and one grounding conductor Lg respectively connected to the three capacitors Cy1 to Cy3 can be led out. For example, it has a case 100 made of synthetic resin. In the example of FIG. 17, the grounding conductor Lg has three lead wires L1 to L
3, and is routed inside the case 100 together with these three lead wires L1 to L3 so as to be led out from the same surface (upper portion in the example of FIG. 17) of the case 100. ing.

[0007] At the bottom of the case 100, a case 1
An attachment piece for attaching 00 to a device is integrally provided with a synthetic resin. Further, the three lead wires L1 to L1
L3 is used as an input terminal or an input terminal is connected, and the one grounding conductor Lg is used as a ground terminal or connected to a ground terminal.

[0008] Another conventional block capacitor is:
As shown in FIG. 18, it has substantially the same configuration as the block capacitor shown in FIG.
2 is different. Also in this case, the ground plate terminal 102
Are bent in the case 100 so as to be led out of the case 100 together with the three lead wires L1 to L3.

The block capacitor according to the conventional example and the block capacitor according to another conventional example are, for example, as shown in FIG. 19, a grounding capacitor (Y) between three input terminals φ1 to φ3 and a common terminal φc. The common terminal φc is connected to a grounding conductor Lg (see FIG. 17) or a grounding plate terminal 102.
(See FIG. 18) to connect to the ground terminal φg.

[0010]

Normally, a block capacitor is used alone or in combination with a choke coil to constitute a noise filter. The block capacitor shown in FIGS. 17 and 18 is, for example, a choke coil and a noise filter. Are connected between the output terminals. In particular,
Three output lines derived from the three-phase choke coil and three lead lines L derived from the block capacitor
1 to L3 are electrically connected through input terminals φ1 to φ3, respectively, and a ground lead Lg or a ground plate terminal 102 derived from a block capacitor is connected to GND through a ground terminal φg.

In this case, in the block capacitor according to the conventional example shown in FIG. 17, the grounding conductor Lg is a vinyl-coated conductor, and is routed inside the case 100 so as to be led out from the upper surface of the case 100. In the block capacitor according to another conventional example shown in FIG. 18, the grounding plate terminal 102 is connected to the case 10 so that the grounding plate terminal 102 is led out from the upper surface of the case 100.
Since the bending is performed within 0, the inductance of the grounding lead is inevitably increased, and there is a problem that the frequency characteristic for a high-frequency signal is poor.

When the block capacitor is mounted on a device, the case 100 is mounted on the device using a mounting jig such as a screw, and further, a grounding lead Lg or a grounding plate terminal led out from the upper surface of the case 100. In order to connect the wire 102 to GND, it is necessary to perform wiring connection work. In addition, in this wiring connection work, it may be necessary to perform wiring routing or bending work on the grounding plate terminal 102, and thus the There is a problem that mounting work becomes very complicated.

The present invention has been made in view of such problems, and can improve frequency characteristics, and can also improve noise attenuation characteristics when a noise filter is used and simplify mounting work. An object is to provide a block capacitor that can be realized.

[0014]

According to a first aspect of the present invention, there is provided a block capacitor according to the present invention, wherein a plurality of capacitors and the plurality of capacitors are housed, and a plurality of terminals respectively connected to the plurality of capacitors are external. And a device mounting portion of the case is also used as a ground terminal.

In this case, in addition to the plurality of terminals, GN
Since it is not necessary to connect a grounding lead for connecting to D to a plurality of capacitors and route it together with a plurality of terminals to, for example, the upper surface of the case, the inductance of the grounding lead can be greatly reduced. As a result, the frequency characteristics can be improved, and when the block capacitor is used as a component of the noise filter, the noise attenuation effect can be further enhanced.

When a block capacitor is mounted on a device, the ground terminal is directly connected to GND simply by attaching the case to the device. This eliminates the wiring connection work to the ground terminal, which is conventionally performed. As a result, the work of mounting the block capacitor can be simplified and the number of steps can be reduced.

In the above configuration, a mounting piece on which a mounting jig is mounted may be provided integrally with the device mounting portion (the invention according to claim 2). In this case, by attaching the mounting jig to the mounting piece, the mounting of the case to the device and the connection of the ground terminal to GND are performed at the same time. This is very advantageous in reducing the amount.

In the above configuration, a grounding capacitor may be connected between each of the plurality of terminals and the device mounting portion (the invention according to claim 3). A capacitor may be connected (the invention according to claim 4). In this case, the inductance of the leads of the grounding capacitor can be reduced, which is very advantageous in improving the frequency characteristics.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment in which the block capacitor according to the present invention is applied to a three-phase three-wire block capacitor used for noise suppression of a power line of a three-phase power control device such as an inverter (for example). Hereinafter, simply referred to as a block capacitor according to the embodiment) will be described with reference to FIGS.
This will be described with reference to FIG.

The block capacitor according to the present embodiment has three capacitors Cy as shown in FIGS.
It has a case 10 in which 1 to Cy3 can be stored. Each of the capacitors Cy1 to Cy3 is a film capacitor (capacity = 100 pF to 10 μF) in which a plastic film is used as an insulating material to be inserted between the electrodes and the outer shape is substantially cylindrical or flat. Lead wires (La1 to La3) and (Lb1 to
Lb3) is derived. These lead wires (La1 to
La3) and (Lb1 to Lb3), lead wires (hereinafter simply referred to as one lead wire) derived from one electrode (the electrode connected to the power supply line) of each of the capacitors Cy1 to Cy3. La3 is a vinyl-coated lead, and one of these three leads La1-La3 is used.
La3 is used as input terminals φ1 to φ3 (see FIG. 4), respectively, or connected to input terminals φ1 to φ3.

The case 10 is integrally formed (for example, by injection molding or extrusion molding) of a synthetic resin into a rectangular tube having an upper opening and a lower opening, and the three capacitors Cy1 to Cy3 housed in the case 10 are formed. Is positioned and sealed by the resin 12 filled in the case 10. In addition, as the case, in addition to the case 10 made of the synthetic resin, a conductive case, a case formed by drawing, a bent metal case, or the like can be used.

As shown in FIG. 3, a metal electrode terminal plate 14 is fixed to the lower opening of the case 10 by, for example, an adhesive so as to close the lower opening. The electrode terminal plate 14 is formed by forming a metal plate such as a copper plate, an aluminum plate, or a cold-rolled steel plate (SPCC) into a flat rectangular shape according to the shape of the lower opening of the case 10, and one long side thereof. Is integrally formed with a mounting piece 16 protruding outward in parallel with the plate surface. One screw insertion hole 18 is provided substantially at the center of the mounting piece 16.

The electrode terminal plate 14 has three lead wires (hereinafter simply referred to as the other lead wires) extending from the other electrodes (electrodes on the side connected to GND) of the three capacitors Cy1 to Cy3. The three lead wire insertion holes 20 through which Lb1 to Lb3 can be inserted are formed. The peripheral portion 22 of each of the lead wire insertion holes 20 is formed in a shape protruding upward, and the one lead wire Lb
When the three capacitors Cy1 to Cy3 are attached to the electrode terminal plate 14 by inserting the corresponding capacitors 1 to Lb3 into the corresponding lead wire insertion holes 20, the upper ends of the raised portions 22 of the electrode terminal plate 14 are connected to the other electrode of the capacitor. , And each of the capacitors Cy1 to Cy1
The attachment state of Cy3 to the electrode terminal plate 14 is firm and does not easily come off. As shown in FIG. 2, one of the lead wires Lb1 to Lb3 protruding from the back surface of the electrode terminal plate 14 to more completely prevent the detachment.
It is desirable to bend each of the front end portions of each.

When assembling this block capacitor, as shown in FIG. 3A, three capacitors Cy1 to Cy are inserted into each lead wire insertion hole 20 of the electrode terminal plate 14.
3, the other lead wires Lb1 to Lb3 are inserted,
The three capacitors Cy1 to Cy3 and the electrode terminal plate 14 are electrically connected by soldering, welding, or another method (see FIG. 3B).

Then, as shown in FIG. 3C, the case 10 is placed on the electrode terminal plate 14 so as to surround the three capacitors Cy1 to Cy3 by the case 10, and
By bonding, for example, an adhesive to the periphery except the mounting piece 16 and the lower inner periphery of the case 10, an electrode terminal plate 14 is formed.
Is fixed to the case 10. At this time, one lead wire La1-La of each of the three capacitors Cy1-Cy3.
3 is drawn out through the upper opening of the case 10.

Thereafter, the case 10 is filled with the resin 12 (see FIG. 1), and the three capacitors Cy1 to Cy3 are sealed with the resin in the case 10, thereby completing the block capacitor according to the present embodiment.

That is, in the present embodiment, case 1
The shield case 24 of the block capacitor is constituted by the zero, the resin 12 filled in the case 10, and the electrode terminal plate 14.

When the block capacitor according to the present embodiment is mounted on a device, the electrode terminal plate 14 is brought into direct contact with the housing of the device as a GND, and in this state, the screw of the mounting piece 16 is inserted. By inserting a screw through the hole 18 and screwing it into the device, the mounting of the block capacitor on the device is completed. That is, in the present embodiment, the electrode terminal plate 14 forming one part of the shield case 24 is also used as a ground terminal.

In this case, as shown in FIG. 4, the block capacitor comprises three input terminals φ1 to φ3 and a common terminal φc.
, The grounding capacitors (Y capacitors) Cy1 to Cy3 are respectively connected between the electrode terminal plates 14, and the common terminal φc is directly connected to GND.

As described above, in the block capacitor according to the present embodiment, the electrode terminal plate 14 constituting one part of the shield case 24 is also used as the ground terminal φg, so that one of the three lead wires is used. La1 to La3
In addition to this, it is not necessary to route a grounding conductor for connecting to GND, and the inductance of the grounding lead can be greatly reduced. As a result, the frequency characteristics can be improved, and when the block capacitor is used as a component of the noise filter, the noise attenuation effect can be further enhanced.

Here, an example having the same configuration as the block capacitor according to the present embodiment and a comparative example having the same configuration as the block capacitor according to the conventional example shown in FIG. 17 are prepared. The result of examining the attenuation characteristics will be described.

First, in the embodiment, as shown in FIG. 5, the resonance frequency is 7,064, 664.621 Hz (about 7 Hz).
MHz), and in the comparative example, as shown in FIG.
996, 490.102 Hz (about 3 MHz)
The resonance frequency of the example is higher than that of the comparative example. In general, the impedance of a block capacitor decreases in proportion to the frequency, but the impedance has a resonance frequency determined by a minimum value determined by the resistance component of the block capacitor and an inductance component. Instead, it works as an inductor.

Therefore, when looking at the noise attenuation characteristics when a noise filter (EMI filter) is manufactured using a block capacitor, the embodiment (see FIG. 7) has a higher frequency than the comparative example (see FIG. 8). It can be seen that the noise attenuation effect is improved.

In the block capacitor according to the present embodiment, when the block capacitor is mounted on a device, only the electrode terminal plate 14 side of the shield case 24 is attached to the device housing, and the three capacitors Cy1 to Cy1 are mounted.
Since each of the other electrodes in Cy3 is directly connected to GND through the electrode terminal plate 14, the operation of connecting the wiring to the ground terminal, which has been conventionally performed, can be omitted, and the mounting operation of the block capacitor can be simplified and the number of steps can be reduced. Reduction can be realized.

In particular, in this embodiment, since the attachment piece 16 is provided integrally with the electrode terminal plate 14, it is very difficult to attach the electrode terminal plate 14 side of the shield case 24 to the housing of the device. This is advantageous in simplifying the mounting operation of the block capacitor and reducing the number of steps.

In the block capacitor according to the above-described embodiment, by displaying, for example, printing or engraving of a content indicating "grounding" on a portion of the outer peripheral surface of the case 10 close to the electrode terminal plate 14. Thus, the efficiency of the mounting operation can be further improved.

In the block capacitor according to the embodiment, when three capacitors Cy1 to Cy3 are attached to the electrode terminal plate 14, the other lead wires Lb1 to Lb1 are inserted into the lead wire insertion holes 20 formed in the electrode terminal plate 14. Lb
3 was inserted and electrically connected by soldering or welding. In addition, as shown in FIG.
The other electrodes of the two capacitors Cy1 to Cy3 are brought into direct contact with the electrode terminal plate 14, and these electrodes and the electrode terminal plate 14
May be electrically connected by soldering, welding, or other methods. In this case, the size in the height direction can be reduced, and the lead wires Lb1 to Lb3 for leading out from the other electrode are not required, which is advantageous in reducing the manufacturing cost.

As another mounting structure, as shown in FIG. 10, among the three capacitors Cy1 to Cy3, for example, the other lead wires Lb1 and Lb2 of the two capacitors Cy1 and Cy2 are bent to the right, for example.
The other lead wire Lb3 of the remaining one capacitor Cy3 may be bent leftward, and these bent portions may be electrically connected to the electrode terminal plate 14 by soldering, welding, or other methods.

In the above-described embodiment, an example is shown in which the mounting piece 16 is integrally formed on one long side of the electrode terminal plate 14 (see FIG. 11A). In addition, as shown in FIG. 11B, The mounting pieces 16 may be formed integrally on one short side, or the mounting pieces 16 may be formed integrally on both short sides.

In the above-described embodiment, the case 10 has a rectangular tube shape having an upper opening and a lower opening. However, as shown in FIGS. From the bottom to the bottom, and the metal electrode terminal plate 14 may be fixed with an adhesive, for example, so as to close the bottom opening. In this case, one of the three lead wires La1 to La3 is drawn out from the front side of the case 10. The position at which the mounting piece 16 is formed on the electrode terminal plate 14 is determined by the long side of the front side of the electrode terminal plate 14 (FIG.
2A), a long side portion on the back side of the electrode terminal plate 14 (see FIG. 12B), and both long side portions of the electrode terminal plate 14 (FIG. 12C).
), Both short sides of the electrode terminal plate 14 (see FIG. 12D).
and so on.

As one of the three lead wires La1 to La3 drawn out of the shield case 24,
There are a one-terminal type shown in FIG. 13 and a two-terminal type shown in FIG. 14, and in each case, a lead wire type (FIG. 13A and FIG.
4A), coated lead wire type (including a shielded wire. FIG. 1)
3B and FIG. 14B), faston terminal type (FIG. 13C)
And FIG. 14C), a bolt / nut type (see FIGS. 13D and 14D), and a board terminal type (FIGS. 13E and 14E).
See).

In the above embodiment, as shown in FIG. 4, three input terminals φ1
Φ3 and three Y capacitors Cy1 to Cy3 connected between the electrode terminal plate 14 (common terminal φc)
Although a circuit configuration having a line structure is adopted, as shown in FIG. 15A, a terminal-to-terminal capacitor (X capacitor: capacitance = 100 pF to 100 μm) is provided between three input terminals φ1 to φ3.
F) Cx1 to Cx3 are connected and three input terminals φ1 to φ
3 and the electrode terminal plate 14 (common terminal φc)
A circuit configuration of a three-phase three-wire structure in which two Y capacitors Cy1 to Cy3 are connected, or as shown in FIG.
X is applied between each of the three input terminals φ1 to φ3 and the common contact a.
A circuit configuration of a three-phase three-wire structure in which capacitors Cx1 to Cx3 are connected and one Y capacitor Cy is connected between the common contact a and the electrode terminal plate 14 may be adopted.

In the above embodiment, the three-phase three-wire structure has been mainly described. However, as shown in FIG. 16, the present invention is also applied to a single-phase two-wire block capacitor having two input terminals φ1 and φ2. Can be done. Specifically, as shown in FIG. 16A, two input terminals φ1 and φ1
A circuit having a single-phase two-wire structure in which one X capacitor Cx is connected between the two and two Y capacitors Cy1 and Cy2 are connected between the two input terminals φ1 and φ2 and the electrode terminal plate 14 (common terminal φc), respectively. It may be configured as shown in FIG.
As shown in FIG. 2B, X capacitors Cx1 and Cx2 are connected between the two input terminals φ1 and φ2 and the common contact a, respectively, and one Y capacitor Cy is connected between the common contact a and the electrode terminal plate 14. A circuit configuration having a line structure may be used. Further, as shown in FIG. 16C, two input terminals φ1
And a circuit configuration in which Y capacitors Cy1 and Cy2 are respectively connected between .phi.2 and the electrode terminal plate 14 (common terminal .phi.c).

It should be noted that the present invention is not limited to the above-described embodiment, but can adopt various configurations without departing from the gist of the present invention.

[0045]

As described above, according to the block capacitor of the present invention, a plurality of capacitors and the plurality of capacitors can be accommodated, and a plurality of terminals respectively connected to the plurality of capacitors are externally provided. A case that can be led out is provided, and a device mounting portion of the case is also used as a ground terminal.

As a result, the frequency characteristics can be improved, and further, the noise attenuation characteristics in the case of a noise filter can be improved and the mounting operation can be simplified.

[Brief description of the drawings]

FIG. 1 shows an embodiment in which a block capacitor according to the present invention is applied to, for example, a three-phase three-wire block capacitor used for noise suppression of a power line of a three-phase power control device such as an inverter (hereinafter simply referred to as an embodiment). FIG. 2A is a plan view, and FIG. 2B is a front view.

FIG. 2 is a two-sided view showing a configuration of the block capacitor according to the present embodiment, particularly a configuration before resin sealing, and FIG.
Is a plan view, and FIG. B is a longitudinal sectional view.

FIGS. 3A and 3B are perspective views of three modes showing a configuration of a block capacitor according to the present embodiment, wherein FIG. 3A is an exploded perspective view, and FIG. 3B is a perspective view when three capacitors are attached to an electrode terminal plate. FIG. C is a transparent perspective view when the case is attached.

FIG. 4 is an equivalent circuit diagram of the block capacitor according to the present embodiment.

FIG. 5 is a diagram illustrating frequency characteristics (resonance points) of a block capacitor according to an example.

FIG. 6 is a diagram illustrating frequency characteristics (resonance points) of a block capacitor according to a comparative example.

FIG. 7 is a diagram illustrating frequency characteristics (noise attenuation characteristics) of the block capacitor according to the example.

FIG. 8 is a diagram illustrating frequency characteristics (noise attenuation characteristics) of a block capacitor according to a comparative example.

FIG. 9 is a two-sided view showing a modified example of the block capacitor according to the present embodiment, particularly showing an example of a structure for attaching three capacitors to an electrode terminal plate.
Shows a plan view, and FIG. B shows a longitudinal sectional view.

FIG. 10 is a two-sided view showing a modification of the block capacitor according to the present embodiment, particularly showing another example of a structure for attaching three capacitors to an electrode terminal plate. Shows a plan view, and FIG. B shows a longitudinal sectional view.

FIG. 11 is a view showing a modified example of the block capacitor according to the present embodiment, particularly showing a modified example of a formation position of a mounting piece.

FIG. 12 is a diagram showing a modification of the block capacitor according to the present embodiment, and particularly showing a modification of the case.

FIG. 13 is a view showing a modification of the block capacitor according to the present embodiment, and particularly showing a modification of the one-terminal type of one lead wire.

FIG. 14 is a view showing a modification of the block capacitor according to the present embodiment, and particularly showing a modification of a two-terminal type of one lead wire.

FIG. 15 is a diagram illustrating a modification of the block capacitor according to the present embodiment, and is an equivalent circuit diagram particularly illustrating a modification of the three-phase three-wire structure.

FIG. 16 is a diagram illustrating a modification of the block capacitor according to the present embodiment, and in particular, is an equivalent circuit diagram illustrating a modification of the single-phase two-wire structure.

FIG. 17 is a front view showing a configuration of a block capacitor according to a conventional example.

FIG. 18 is a perspective view showing the configuration of a block capacitor according to another conventional example.

FIG. 19 is an equivalent circuit diagram of a block capacitor according to a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Case 12 ... Resin (for sealing) 14 ... Electrode terminal plate 16 ... Mounting piece 18 ... Screw insertion hole 20 ... Lead wire insertion hole 24 ... Shield case Cy, Cy1-Cy
3 Y capacitor Cx, Cx1 to Cx3 X capacitor La1 to La3 One lead Lb1 to Lb3 The other lead

Claims (4)

[Claims] A plurality of capacitors; and a case in which the plurality of capacitors can be housed and a plurality of terminals respectively connected to the plurality of capacitors can be led out to the outside. A block capacitor characterized in that the terminal also serves as a ground terminal. 2. The block capacitor according to claim 1, wherein a mounting piece for mounting a mounting jig is provided integrally with the device mounting portion. 3. The block capacitor according to claim 1, wherein a grounding capacitor is connected between each of the plurality of terminals and the device mounting portion. 4. The block capacitor according to claim 3, wherein an inter-terminal capacitor is connected between the plurality of terminals.