JP2011205211A - Noise filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact noise filter that includes primary and secondary line structure units detachable form a choke coil, to achieve easy and quick response to a change in specifications, while allowing easy mounting on a target device.SOLUTION: In the noise filter having capacitors disposed on the end surfaces on both sides of the choke coil 7, the primary and secondary line structures including the capacitors are configured as primary and secondary units 22, 23 which are detachable from the choke coil 7.

Description

  The present invention relates to a noise filter, and more particularly, to a noise filter configured as a unit in which primary and secondary line structure portions incorporating a capacitor can be replaced with a central choke coil.

  In general, this type of noise filter has a primary line and a secondary line drawn on both sides of the choke coil, and an interline capacitor (Cx capacitor) is provided on each of the primary and secondary lines. A line-ground capacitor (Cy capacitor) is provided on the secondary line. Specifically, such a noise filter includes a common mode choke coil wound around a toroidal magnetic core for attenuating common mode noise flowing between the line and ground, and common mode noise that cannot be removed by the common mode choke coil. And a Cx capacitor for attenuating normal mode noise flowing between the lines.

  In Patent Document 1, in a noise filter having a Cx capacitor connected between phases of a power supply line and a Cy capacitor connected between each phase of the power supply line and ground, a switch that can be opened and closed between the Cy capacitor and ground Even if the specification is such that the capacity of the Cy capacitor is large and the leakage current from the Cy capacitor is large, for example, in each country's circumstances (power supply circumstances), for example, temporarily under a power supply environment that only supports a small leakage current In use, the switch means disconnects the Cy capacitor from the ground to eliminate the leakage current and prevent the leakage breaker from operating.

  In addition, there is a three-phase noise filter in which the impedance between the AC power line of each phase to the Cx capacitor is made equal and the wiring pattern from the power line to the ground via the Cy capacitor is minimized. It is disclosed (for example, Patent Document 2).

JP 2002-252535 A JP 2005-184074 A

  Conventionally, this type of noise filter has a choke coil and a primary side and secondary side line structure that are integrally formed and housed in a case, and the specifications of filter constants and characteristic values are determined for each noise filter. Therefore, it is not possible to obtain a desired constant or characteristic value by exchanging a built-in capacitor or the like in accordance with the use location or use situation. In order to change the constants and characteristic values of the capacitors and filters, the whole had to be replaced with a noise filter of another specification, and the degree of freedom in device design was limited.

  Further, in the conventional noise filter, even when a part of the component parts, for example, a part of the built-in Cx capacitor or Cy capacitor is damaged, it is necessary to disassemble the entire noise filter and repair the failure part. There was a problem that wiring connection and assembly were newly required each time. In addition, since the capacitor and the choke coil are integrally connected by wiring, it takes time to assemble, and there are many restrictions in sharing each component of the line structure portion.

  In Patent Document 2 described above, a choke coil is accommodated in a cylindrical cap, and one end of the cap is closed with a base with an input terminal line, and a printed wiring board is installed on one side of the choke coil. In this case, the Cx capacitor and the Cy capacitor are mounted on the wiring board. In this case, the lead wires of the Cx capacitor and the Cy capacitor are solder-connected to the plated through hole connecting portion of the conductor pattern formed on the wiring board. is doing. The terminal wire of the choke coil is also solder-connected to the wiring board through a through hole, and the wiring board on which the Cx capacitor or Cy capacitor is mounted can be easily detached from the choke coil. However, when the specification is changed, the whole including the choke coil must be replaced with a new noise filter.

  The present invention solves the above-mentioned problems and unitizes the primary side line structure part and the secondary side line structure part to the choke coil so as to be detachable, thereby easily and quickly responding to changes in specifications. An object of the present invention is to provide a noise filter obtained.

  Another object of the present invention is to provide a noise filter which can compactly assemble a choke coil and primary and secondary side line structures, is small, and can be easily mounted on a target device.

It is another object of the present invention to provide a noise filter that protects the terminal portion by covering the connection terminal portion with a cylindrical case of an outer shell so as to be opened and closed.

  According to the present invention, there is provided a noise filter in which capacitors are disposed on both sides of an end face of a choke coil, and a primary side and a secondary side line structure including the capacitor can be detachably attached to the choke coil. A noise filter configured as a side and secondary side unit is provided.

  In one embodiment of the present invention, the primary side line structure is integrated as a detachable primary side unit including an inter-line capacitor (Cx capacitor), and the secondary side line structure is between lines. It is characterized by being integrated as a detachable secondary unit including a capacitor and a line-ground capacitor (Cy capacitor).

  In another embodiment of the present invention, the choke coil is constituted by a toroidal coil, the primary side and secondary side line structures are each formed in a circular unit, and the circular unit and the choke are formed. When the primary side and secondary side unit are engaged with the choke coil, the primary side and secondary side unit and the It is characterized in that electrical connection with the choke coil is made.

  In still another embodiment of the present invention, the choke coil and the primary and secondary units are housed in a cylindrical case.

  In still another embodiment of the present invention, connection terminal portions are formed in the peripheral portions of the primary side and secondary side units, and the cylindrical case is connected to the primary side and secondary side units and the choke coil. The opening is formed so as to be rotatable and the connection terminal portion can be exposed in the peripheral portion of the case, and the connection terminal portion is shielded by the rotational position of the cylindrical case.

In still another embodiment of the present invention, the primary side and secondary side line structures are each formed in a rectangular unit, and the rectangular unit and the holding frame of the choke coil are latched and engaged. So that the primary side and secondary side units are electrically connected to the choke coil when the primary side and secondary side units are engaged to the choke coil. It is characterized by that.

  In the noise filter according to the present invention, the primary side and secondary side line structures are unitized. Therefore, when the specifications such as the filter constant are changed, the choke coil can be easily replaced. The whole is compact and downsizing can be achieved.

It is a perspective view of the noise filter by Example 1 of this invention. It is a perspective view of the primary side unit of the noise filter concerning the present invention. It is the top view (A) and side view (B) of a primary side unit which are shown in FIG. It is a perspective view of the secondary side unit of the noise filter by Example 1 of this invention. It is the top view (A) and side view (B) of a secondary side unit which are shown in FIG. It is an external appearance perspective view of the columnar noise filter by Example 2 of this invention. It is a figure which shows the various attachment examples of the noise filter which concerns on Example 2 of this invention. It is the side view which partly cut off the microphone incorporating the noise filter which concerns on Example 1 of this invention. It is a figure which shows the three-phase circuit of the noise filter which concerns on Example 1 of this invention. It is a figure which shows the modification of the three-phase circuit of the noise filter which concerns on Example 1 of this invention. It is a figure which shows the single phase circuit of the noise filter which concerns on Example 1 of this invention.

Next, various embodiments of the present invention will be described with reference to the drawings.

  Next, various embodiments of the present invention will be described with reference to the drawings. The noise filter according to the present invention is configured as a three-phase circuit or a single-phase circuit. First, a three-phase circuit to which the present invention is applied will be described. In FIG. 9, a three-phase type noise filter includes three terminal portions 1 to 6 and a primary side line structure portion 10 and a secondary side line structure portion 11 respectively. Has a ground terminal. In the first embodiment of the present invention, a toroidal coil is used as a choke coil, and a toroidal coil 7 wound around a toroidal magnetic core to attenuate common mode noise flowing between the line and the ground, and normal mode noise flowing between the lines are used. Cx capacitors 12 and 13 connected between the primary and secondary lines for attenuation, and a Cy capacitor 14 connected between the secondary line and ground G for attenuating common mode noise, respectively. And a bleeder resistor 15 for discharging a capacitor connected between the respective lines on the primary side. In addition, you may provide the earth inductor etc. which suppress intrusion of the noise from a ground.

  As a modification of the three-phase circuit shown in FIG. 9, as shown in FIG. 10, a large-capacity Cy capacitor and a small-capacity Cy capacitor are connected in parallel, and three sets of Y capacitors 16 are connected between the line and the ground. Is arranged. Other configurations are the same as those in FIG.

  In the present invention, not only the three-phase circuit noise filter described above but also a single-phase circuit as shown in FIG. The single-phase circuit of the embodiment shown in FIG. 11 is basically the same as the three-phase circuit, and Cx arranged between the two terminal portions 17 and 18 and the primary side line on the primary side of the toroidal coil. A capacitor 12, a bleeder resistor 15, a Cx capacitor 12 disposed between the secondary side terminal portions 19 and 20, and the secondary side line, and a Cy capacitor 14 provided between the ground G and each secondary side line are provided. Yes.

Primary side unit Next, the primary side unit which becomes a primary side line structure part is demonstrated with reference to FIGS. 1-3.
FIG. 1 is a perspective view of a noise filter according to a first embodiment of the present invention, as viewed from the outer end surface side of a secondary unit described later. FIG. 2 is a perspective view of the primary unit 22 and shows a state seen from the back side thereof, that is, the side facing the toroidal coil 7 (FIG. 1). 3 is a plan view and a side view of the primary unit shown in FIG. 3A is a plan view seen from the outer end surface of the primary unit 22, and FIG. 3B is a side view seen from the arrow F in FIG. 3A. Referring to these drawings, the primary line structure portion of the noise filter has a unitized structure so as to be detachable from the toroidal coil 7. In the primary side unit 22, side pillars 32 having three arc-shaped side portions are formed around the back surface (coil side) of the primary side end plate 31 exposed to the outer surface. At the top, an engagement hole 39 is formed that is detachably engaged with the holding frame 53 of the toroidal coil 7. The holding frame 53 and the side column 32 are detachably fixed by a method such as engaging with an engaging portion of the holding frame 53 facing the engaging hole or screwing the engaging hole 39. ing. At the center of the primary unit 22, a central column 33 is formed in contact with the magnetic core of the toroidal coil 7. Reference numeral 34 denotes a heat radiating hole formed in the central column 33.

  Three conductor plates 35 are provided between the adjacent side columns, and a coil terminal screw 36 connected to the toroidal coil 7 and a line terminal connected to the primary side conductor line on the outside of the conductor plate 35, respectively. A screw 37 is provided. In addition, three resistance elements 38 and three Cx capacitors 40 are arranged between three conductor plates 35 adjacent in the circumferential direction. As shown in the figure, the coil terminal screw 36 and the line terminal screw 37 are exposed to the outer peripheral side from between the side columns 32. As described above, a plurality of primary side units 22 having the resistors 38 and the Cx capacitors 40 and having different specifications of the filter constants and the filter characteristic values provided by the resistor elements 38 and the Cx capacitors 40 are prepared. However, the outer diameter (and outer shape of the end plate) and the width L in the axial direction (FIG. 3) of the primary side unit 22 composed of the three side pillars 32 are formed to be the same for all specifications. .

  As shown in FIG. 1, the toroidal coil 7 is held by a holding frame 53, and the end face thereof is fitted with the central column 33 of the primary unit 22. The lead wire on one side of the toroidal coil is connected to a conductor plate provided on the holding frame 53. With this configuration, the primary side unit 22 can be easily latched to the end face of the toroidal coil by the engaging portion, and the coil is simultaneously with the latch by the contact between the unit side conductor plate 35 and the coil side conductor plate. 7 and the primary unit 22 are automatically connected without the need for soldering or the like.

Secondary Unit Next, the configuration of the secondary unit serving as the secondary line structure unit will be described with reference to FIGS. 4 and 5. FIG. 4 is a perspective view of the secondary unit 23 of the noise filter according to the first embodiment of the present invention, and shows a state seen from the back side thereof, that is, the side facing the toroidal coil, similarly to FIG. FIG. 5 is a plan view and a side view of the secondary unit 23 shown in FIG. 5A is a plan view seen from the outer end surface of the secondary unit 23, and FIG. 5B is a side view seen from the arrow E in FIG. 5A. Similar to the primary side unit 22, the secondary side unit 23 is structured to be detachable from the toroidal coil 7 (FIG. 1). In the secondary unit 23, side pillars 32 having three arc-shaped side portions are formed around the back surface (coil side) of the secondary end plate 41 exposed on the outer surface of the noise filter, and each arc-shaped side An engagement hole 39 is formed at the top of the part so as to be detachably engaged with the holding frame 53 that holds the toroidal coil 7. The side column 32 and the holding frame 53 are detachably engaged with each other by engaging with the engaging portion of the holding frame 53 facing the engaging hole 39 or by screwing the engaging hole 39. It is like that. Further, a central support 33 is formed at the center so as to be in contact with the magnetic core end face of the toroidal coil 7. Reference numeral 42 denotes a heat radiating hole formed in the central column 33.

  Three conductor plates 35 are provided between the adjacent side pillars 32, and a coil terminal screw 36 connected to the toroidal coil 7 and a line connected to the secondary conductor line are respectively provided on the outer side of the conductor plate 35. A terminal screw 37 is provided. Further, three Cx capacitors 40 and three sets of Cy capacitors 43 are arranged between the three conductor plates 35 adjacent in the circumferential direction. This embodiment is an example of the noise filter shown in the circuit diagram of FIG. 10, and the Cy capacitor 43 is configured by connecting three sets of two capacitors connected in parallel, but the circuit diagram of FIG. When it is configured as a noise filter according to the above, three Cy capacitors are provided as a whole. Further, an earth terminal plate 44 connected to the ground is provided on the outer surface of the end plate 41 of the secondary unit 23, and an earth terminal screw 45 (FIGS. 1 and 5) for connecting the earth conductor is provided at the center thereof. Yes.

  As shown in the figure, the coil terminal screw 36 and the line terminal screw 37 are exposed to the outer peripheral side from between the side columns 32. In this way, the secondary unit 23 in which the secondary line structure unit is unitized has different specifications for the filter constants and the filter characteristic values provided by the Cx capacitor 40 and the Cy capacitor 43, as in the unit of the primary unit 22. There are several types of products, but each specification is composed of three side pillars 32 and is formed to have the same outer diameter (and outer shape of the end plate) as the primary unit and the width H in the axial direction. ing.

  As shown in FIG. 1, the toroidal coil 7 is held by a holding frame 53, and a coil side engaging portion that fits with the engaging portion 34 of the central column 33 of the secondary unit 23 is formed on the end surface thereof. Yes. The lead wire on one side of the toroidal coil facing the secondary unit 23 is connected to a conductor plate provided on the holding frame 53. With this configuration, the secondary unit 23 can be easily latched to the end face of the toroidal coil by the engaging portion, and the coil is simultaneously with the latch by the contact between the unit side conductor plate 35 and the coil side conductor plate. 7 and the secondary side unit 23 are automatically connected without the need for soldering or the like. This relationship is the same as in the case of the primary unit.

In the noise filter according to the present invention, the primary side unit and the secondary side unit are formed by unitizing the primary side and secondary side line structures so that the specifications of the constants and characteristic values of the filter are changed. This can be easily handled by exchanging 23. For example, in the power supply environment to be used, from the normal state where the capacitance of the primary and secondary Cx capacitors is 3.3 μF, respectively, and the capacitance of the secondary Cy capacitor is 1.5 μF. The need to remove large ambient noise arises. The capacitance of the primary Cx capacitor is 2.2 μF, the capacitance of the secondary Cx capacitor is 0.22 μF, and the capacitance of the secondary Cy capacitor is 0.22 μF. When there is a change in specifications, it can be quickly handled by replacing the primary side and secondary side units that employ a capacitor of the corresponding type.
Conversely, for example, in order to remove minute noise, the primary side and secondary side Cx capacitors should be 2.2 μF, and the secondary side Cy capacitor must be 3300 pF. By replacing the primary side and secondary side unit using a corresponding ceramic capacitor, it is possible to easily and quickly respond without replacing the entire noise filter. For example, a unit having a characteristic of a secondary-side Cy capacitor of 0.47 μF, a primary-side and a secondary-side Cx capacitor of 2.2 μF, and other units having various characteristic values are prepared. It can easily cope with changes in the power supply environment. Examples of combinations of the primary side and the secondary side are shown in Table 1.

  FIG. 8 is a diagram showing an application example of the cylindrical noise filter according to the first embodiment of the present invention. In this example, the cylindrical noise filter 52 is incorporated in the cylindrical grip 51 of the handheld microphone 50. Since the cylindrical grip 51 itself also serves as the cylindrical case of the noise filter 52, the noise filter 52 is The toroidal coil and the primary and secondary units are integrated into the cylindrical grip 51 of the microphone 50 in a state as shown in FIG. As another example, for example, a cylindrical noise filter can be accommodated in the holding part of an electric screwdriver or a soldering iron, and this type of hand-held compact device can be incorporated without generating useless space. Can do.

  As already described, the noise filter circuit according to the present invention is not limited to the case of the three-phase circuit shown in FIG. 9 or FIG. Similarly, in the case of a circuit, the primary and secondary line structures are configured in a circular unit, and a Cx capacitor, a Cy capacitor, a bleeder resistor, a ground inductor, and the like are provided on the side pillars and ends depending on the corresponding circuit configuration. It is attached using a board.

  FIGS. 6A and 6B are external perspective views of the cylindrical noise filter according to the second embodiment of the present invention. FIG. 6A shows the connection terminal portion exposed, and FIG. 6B shows the connection terminal portion shielded in the case. Shows the state. In the second embodiment, the primary side and secondary side units 22 and 23 provided on both ends of the toroidal coil are accommodated in a cylindrical insulating case 25 including the toroidal coil. In both the primary and secondary units, the three terminal portions 26 and 27 are formed on the circular outer periphery at equal circumferential intervals (60 ° intervals). Further, the cylindrical case 25 is formed with a notch-shaped opening 28 at both ends thereof so as to correspond to the terminal portions of the primary side and secondary side units, respectively. The case 25 can be rotated with a certain amount of frictional force in the circumferential direction with respect to the internal structure, that is, the toroidal coil and the primary side and secondary side units on both sides. Therefore, the case 25 can be rotated. Thus, the terminal screw 29 of the connection terminal portion around the line structure portion can be closed or exposed at the peripheral surface of the case. In the state where the terminal screw 29 is closed by the case 25, the connection line to the outside is drawn out from the outer end surface of each unit.

  The noise filter according to the second embodiment having the cylindrical insulating case 25 can be directly accommodated in a cylindrical space in the electronic / electrical device. It can be easily attached to an external mounting base. FIG. 7 (A) is a suspension type attachment example. A belt member 46 is wound around the periphery of the cylindrical case 25, and the belt member 46 is connected to a suspension rod 47 and suspended from the outer surface of an external device. Can do. FIG. 7B shows an example in which a strip 46 fastened to the periphery of the case is fixed to a mounting base or mounting seat. By rotating the internal line structure part and the toroidal coil side with respect to the case 25, the connection terminal part can be opened and closed.

  In each of the above-described embodiments, the choke coil and the primary side and the secondary side unit have a circular shape. However, the present invention is not necessarily limited to such a circular shape, and the entire outer shape is formed in a square shape. It is also possible. In this case as well, the rectangular primary side and secondary side line structures are configured as a unit that can be attached to and detached from the choke coil, and the primary side and secondary side units are latched to the choke coil with one touch. It is configured to be able to match. When each unit is engaged with the choke coil, the choke coil and the primary side and secondary side units are electrically connected simultaneously and automatically. As a result, when changing the specification, the primary side and / or the secondary side unit can be exchanged with other specifications for the choke coil and can be dealt with easily and quickly.

  The noise filter according to the present invention is not only capable of responding to specification changes by unitizing the line structure part, but is also reduced in size as a whole, so that, for example, in a large facility such as a power control room in a factory, the complex electric power inside There is a device and electrical wiring, but when you do not want to influence the noise between these internal devices, the noise filter according to the present invention does not take up a large space and can be used as a simple relay for the wiring cable. , Can be distributed inside the equipment. In addition, the noise filter according to the present invention can be built in a frame portion such as a flat-screen television and an inverter fluorescent lamp, or an in-vehicle device without generating a useless space.

7 Toroidal coil 10, 22 Primary side line structure 11, 23 Secondary side line structure 12, 13, 40 Cx capacitor 14, 16, 43 Cy capacitor 15 Bleeder resistance 17, 18, 19, 20 Terminal part 25 Cylindrical Insulating case 26 Terminal portion 27 Terminal portion 29 Terminal screw 31 End plate 32 Side column 33 Center column 34 Engaging portion 35 Conductor plate 36 Coil terminal screw 37 Line terminal screw 38 Resistive element 39 Engaging hole 40 Cx capacitor 41 End plate 42 Radiation hole 43 Cy capacitor 44 Ground terminal plate 45 Ground terminal screw 46 Band material 47 Rod 50 Microphone 51 Tubular grip 52 Noise filter 53 Holding frame 60 Noise filter

Claims (6)

  A noise filter in which capacitors are arranged on both sides of an end face of a choke coil, and a primary side unit and a secondary side unit capable of detaching the primary side and secondary side line structures including the capacitor from the choke coil, respectively. A noise filter characterized by comprising as follows.   The primary side line structure is integrated as a detachable primary unit including a line-to-line capacitor, and the secondary line structure is detachable 2 including a line-to-line capacitor and a line-ground capacitor. The noise filter according to claim 1, wherein the noise filter is integrated as a secondary unit.   The choke coil is composed of a toroidal coil, the primary and secondary line structure portions are formed in circular units, respectively, and the circular primary and secondary units and the choke coil When the primary side and the secondary side unit are engaged with the choke coil, the primary frame and the secondary side unit are engaged with the choke coil by releasably engaging the holding frame with the latching engagement portion. The noise filter according to claim 1, wherein an electrical connection is made.   The noise filter according to claim 1, wherein the choke coil and the primary side and secondary side units are accommodated in a cylindrical case.   Connection terminal portions are formed on the peripheral portions of the primary and secondary units, the cylindrical case is formed to be rotatable with respect to the primary and secondary units and the choke coil, and the periphery of the case 5. The noise filter according to claim 4, wherein an opening portion through which the connection terminal portion can be exposed is formed, and the connection terminal portion is shielded by a rotational position of the cylindrical case.   The primary side and secondary side line structures are respectively formed in a rectangular unit, and the rectangular unit and the holding frame of the choke coil are releasably engaged by a latching engagement part, The electrical connection between the choke coil and the line-to-line capacitor and the line-to-ground capacitor is made when the secondary and secondary units are engaged with the choke coil. Item 3. The noise filter according to Item 1 or 2.

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