JP6458232B2 - Output noise reduction device - Google Patents

Description

  The technology disclosed in the present application relates to an output noise reduction device that suppresses noise mixed in an output signal, and particularly relates to a noise reduction device including an inductance element inserted in a signal path of the output signal.

  2. Description of the Related Art Conventionally, there are cases in which switching noise of an operating frequency of an electronic device or the like or a harmonic frequency thereof is mixed in an output voltage or an output signal output from a switching power supply or other electronic device via a conductive bar. Such noise may adversely affect external electronic devices and must be suppressed as necessary. In the switching power supply, an output voltage having a predetermined voltage value is output by the switching operation of the power transistor. Depending on the output rating, noise of the switching frequency and its harmonic frequency is generated by switching the current path by turning on and off the power transistor. It is conceivable that this noise is superimposed on the output voltage and propagated to an external electronic device through the conductive bar. In particular, when a switching power supply is mounted in an automobile, depending on the switching frequency, there is a problem that so-called radio noise is generated, in which noise of the switching frequency and its harmonic frequency is superimposed on an audio signal or the like, which adversely affects viewing. is there.

  In order to suppress such noise, an output noise reduction device such as an inductance element such as a choke coil or a combination of a choke coil and a capacitor is inserted in an output path such as an output voltage (Patent Documents 1 and 2, etc.). The switching power supply device described in Patent Document 1 includes an output filter including a smoothing capacitor and a smoothing reactor in an output path. Moreover, the switching power supply device described in Patent Document 2 includes a core unit configured by surrounding a bus bar serving as an output path with a magnetic core. This magnetic core functions as a noise filter.

JP 2012-210002 A JP 2005-93536 A

In the automotive field, the above-described switching power supply and other electronic devices are partitioned into a base plate and an electronic circuit board from the viewpoint of ensuring reliability in a severe surrounding environment such as vibration, dust, and temperature, or It may be housed in a metal housing such as aluminum. This is a case where the mounted component is stored separately from the outside. In this case, since the output noise reduction device for noise reduction is similarly required to ensure reliability and the like, it is generally mounted in a metal casing as well.

  However, in the above background art, noise generated by switching operation of a switching power supply or other electronic equipment propagates around signal wiring or ground wiring, and is electromagnetic coupling such as capacitive coupling or inductive coupling. Therefore, the output noise is not always sufficiently suppressed. In particular, a noise source generated due to a switching operation or the like and a conductive bar or an output terminal are close to each other in terms of circuit configuration, and may be mounted close to each other. For this reason, noise generated by the switching operation is radiated by electromagnetic coupling such as capacitive coupling and inductive coupling due to parasitic capacitive components and inductive components, etc., depending on the routing of the signal path and ground wiring and mutual arrangement Propagating around the signal path and the ground wiring may reach the conductive bar and the output terminal without going through the output path of the output noise reduction device that performs the original noise reduction function. Even if an output noise reduction device is provided on the output path such as a conductive bar toward the output terminal, noise is mixed into the conductive bar or output terminal at the end of the output noise reduction device, and sufficient noise suppression cannot be performed. There's a problem.

The technology disclosed in the present application has been proposed in view of the above-described problems, and is radiated by electromagnetic coupling caused by an electronic device housed in a metal casing or wraps around through a wiring and outputs. An object of the present invention is to provide an output noise reduction device capable of suppressing noise propagating to a terminal.

An output noise reduction device according to a technique disclosed in the present application is an output noise reduction device that suppresses noise mixed in an output signal from an electronic device housed in a metal casing . A conductive bar, a magnetic core, a mold part, and a first mounting board are provided. The conductive bar is formed of a conductive material, and one end is a connection terminal connected to the output end of the electronic device, and the other end is an output terminal. The magnetic core is formed of a magnetic material and has a through hole through which the conductive bar passes. The mold part is formed of a resin material, and molds the conductive bar excluding the connection terminal and the output terminal and the magnetic core. The first mounting substrate includes a first fixing portion that is molded by the molding portion and is fixed to the conductive bar between the magnetic core and the output terminal, and a second fixing portion that is connected to the metal housing . The first fixed part and the second fixed part are connected by a capacitive element. Electromagnetic coupling from the electronic device is separated from the output terminal of the conductive bar to at least a part of the main body portion having the capacitive component of the capacitive element of the first mounting board.

Thus, a so-called LC filter is configured. In the LC filter, at least electromagnetic coupling between a part of the capacitive element of the first mounting substrate and the electronic device is suppressed. Here, the electromagnetic coupling is capacitive coupling or inductive coupling. Radiated noise propagates through space due to electromagnetic coupling. For this reason, radioactive noise generated due to the operation of the electronic device does not enter at least a part of the output terminal side of the capacitive element of the first mounting substrate. Further, the ground potential supplied to the capacitive element of the first mounting substrate is supplied via a metal casing . Metal housing, because it is wide shape and impedance is sufficiently reduced can be a stable ground potential to which the voltage variation is suppressed. Conductive noise that wraps around through the ground potential is suppressed. Propagation of radiated noise and conductive noise to the output terminal is suppressed, and an output signal in which noise is suppressed is output.

Further, a third fixing portion fixed to the conductive bar between the magnetic core and the connection terminal, a fourth fixing portion connected to the metal housing , and a space between the third fixing portion and the fourth fixing portion. A second mounting board connected by a capacitive element may be provided. Thereby, in addition to the capacitive element of the first mounting board and the inductance element connected in series to the path of the output signal by the magnetic core through which the conductive bar penetrates, the capacitive element of the second mounting board is connected, A so-called π-type filter is configured. In addition, the ground potential supplied to each capacitive element of the first and second mounting substrates constituting the π-type filter is supplied via a metal casing . Metal housing, impedance since it is wide shape are sufficiently reduced, it is possible to a stable ground potential mixing of noise is suppressed. In the π-type filter, the influence of conductive noise propagating from the ground potential through the capacitive element can be suppressed. Further, a T-type filter is configured by further providing a second magnetic core formed of a magnetic material and having a through hole through which a conductive bar passes on the output terminal side of the first mounting substrate.

Further, formed of a conductive material, it is molded in the mold portion except for the both end portions, the mold portions and intended to comprise a base portion to be crimped into the metal housing when secured to the metal housing, the first mounting The second fixing part of the substrate and / or the fourth fixing part of the second mounting board may be fixed to the pedestal part. Accordingly, when the mold portion is fixed to the metal casing , the pedestal portion is pressed against the metal casing , and the second fixing portion of the first mounting substrate and / or the fourth fixing portion of the second mounting substrate is , Connected to ground potential.

Is further connected to the output terminal of the electronic equipment inside the conductive bar of the connecting terminal is metal housing, outwardly from the metallic chassis through the opening of the metal housing in which the output terminal of the conductive bar through the conductive bar the arrangement state in those at least a portion of the body portion having a capacitive component of the capacitive element of the first mounting substrate, which is located outward from metal housing, or positioned in the opening of the metal housing It is good. Thus, the body portion of the electromagnetic coupling is suppressed, the capacitive element of the first mounting substrate located here from the electronic device by the metal housing in the opening of the outer side or the metallic chassis of a metallic chasis The influence of radioactive noise on at least a part of is suppressed. By selecting the mounting position of the output noise reduction device with respect to the metal casing without adding new members / parts, the influence of electromagnetic coupling from the electronic device can be reduced and noise can be suppressed.

Further, the magnetic core comprises at least a portion of the output terminal side may be those located outward from metal housing, or positioned in the opening of the metal housing. Thus, in addition to the capacitive element of the first mounting substrate, outside the inductance element including the portion of the conductive bar that protrudes to the output terminal side from the magnetic core (output terminals) from the metal housing by magnetic core It is located on the side or in the opening of the metal casing . Thereby, the electromagnetic coupling from the electronic device to the conductive bar on the output terminal side is suppressed.

Furthermore, from the output terminal to at least a part of the main body portion having the capacitive component of the capacitive element of the first mounting board may be surrounded by a metal wall. Accordingly, since at least a part of the main body portion of the capacitive element of the first mounting board is surrounded by the metal wall and electromagnetically shielded from the output terminal through the conductive bar, the conductive bar reaching the output terminal and At least a part of the main body portion of the capacitive element of the first mounting substrate on the output terminal side can be arranged in a region where electromagnetic coupling is suppressed. By providing a metal wall that exhibits an electromagnetic shielding effect, it is possible to suppress electromagnetic coupling, and it can also be arranged in a metal casing that may receive radioactive noise from electronic equipment.

  Moreover, it is good also as an electromagnetic shielding board being provided in at least any one end surface among the end surfaces of the penetration direction of the electrically-conductive bar of a magnetic body core. As a result, the conductive bar penetrating the magnetic core can be shielded from the outside world. Propagation of radiant noise from the conductive bar to the outside can be suppressed by electromagnetic coupling. At the same time, it is possible to suppress the propagation of radioactive noise from the outside to the conductive bar. In particular, the shielding of the electric field can be enhanced.

  Further, at least one of the first mounting substrate and the second mounting substrate may have a shape facing the resin material molded in the mold portion when viewed from the penetrating direction or the circumferential direction of the conductive bar. . Thus, when an external force in the penetrating direction or the circumferential direction is applied to the conductive bar, each mounting substrate is molded against the relative movement of the conductive bar between the mold part in the penetrating direction or the circumferential direction. It becomes resistance which opposes the resin material with which the part was filled, and movement can be controlled.

  The conductive bar may include a movement restricting portion that restricts relative movement between the conductive bar and the mold portion in the penetrating direction. As a result, when an external force in the penetration direction is applied to the conductive bar, the movement restricting portion becomes a resistance facing the resin material filled in the mold portion, and the conductive bar relative to the mold portion in the penetration direction Movement can be restricted.

  In this case, the movement restricting portion may include a portion having a different cross-sectional shape as viewed from the penetrating direction in a part of the conductive bar molded in the mold portion. Thereby, when an external force in the penetrating direction is applied to the conductive bar, the difference in cross-sectional shape becomes a resistance to the external force, and the relative movement of the conductive bar between the mold part in the penetrating direction is restricted. Can do.

  In addition, since the conductive bar is formed of a single member from the connection terminal to the output terminal, a fixing member that fixes the member is not required unlike the case where the conductive bar is configured of a plurality of members. . There is no contact resistance intervening in the connection portion due to the connection between the members, and the electrical resistance from the connection terminal to the output terminal can be reduced. Further, the fixing work process is not necessary, and the manufacturing process can be simplified and the cost can be reduced. In addition, at least one of the connection terminal or the output terminal of the conductive bar may have a bolt structure. Thereby, it can fix firmly with the electronic device connected to an output noise reduction apparatus, without adding a member.

  According to the output noise reduction device according to the technology disclosed in the present application, at least a part of the capacitive element of the first mounting substrate on the output terminal side suppresses the electromagnetic coupling from the electronic device and reduces the ground potential from the ground potential. By suppressing the wraparound of the voltage fluctuation, it is possible to suppress radioactive noise and conductive noise from the electronic device mixed in the output signal.

It is a circuit diagram at the time of connecting a noise filter module to a switching power supply as an example of the output noise reduction apparatus which concerns on 1st Embodiment. It is a disassembled perspective view of the noise filter module of 1st Embodiment. 1 is a perspective view of a noise filter module according to a first embodiment ((A) a perspective view in a molded state, (B) a perspective view in a state seen through the inside). FIG. 2 shows a state in which the noise filter module of the first embodiment is assembled to a switching power supply, and is a diagram showing a cross section of the metal casing 3 cut along the axis of a conductive bar 11. It is sectional drawing which shows schematically the internal structure of the noise filter module of 1st Embodiment ((A) Sectional drawing along the electroconductive bar 11, (B) BB sectional drawing, (C) CC sectional drawing). It is a circuit diagram at the time of connecting a pi type filter module to a switching power supply as an example of the output noise reduction device concerning a 2nd embodiment. It is a perspective view of the state which saw through the inside of the pi type filter module of a 2nd embodiment. It is a figure which shows the mounting substrate of 3rd Embodiment. It is a perspective view which shows the internal structure of the noise filter module of 3rd Embodiment. It is sectional drawing which shows the state which assembled | attached the noise filter module of 3rd Embodiment to metal housings . It is a perspective view of the noise filter module of a 3rd embodiment. It is a figure which shows the mounting substrate of 4th Embodiment. It is a schematic AA sectional view of the mounting board of a 4th embodiment. It is a disassembled perspective view of the noise filter module of 5th Embodiment. It is a circuit diagram at the time of connecting a T type filter module to a switching power supply as an example of the output noise reduction device concerning a 6th embodiment. It is a disassembled perspective view of the noise filter module of 6th Embodiment. It is a perspective view in the state where the noise filter module of a 6th embodiment was molded. It is a figure which shows schematically the example of the electroconductive bar of other embodiment. It is a figure which shows schematically the example of the magnetic body core of other embodiment.

FIG. 1 is a circuit diagram of a first embodiment according to the present application. As an example of the output noise reduction device, a case where the noise filter module 1 is connected between the output terminal VX and the output terminal VO of the switching power supply 5 is shown. The switching power supply 5 is housed in a metal housing 3 made of aluminum die casting or the like. In FIG. 1, the electrical effects related to the noise filter module 1 will be described.

  The switching power supply 5 is, for example, an in-vehicle power supply. This is a step-down switching power supply that steps down a voltage value from a main battery (not shown) that supplies a drive system power supply voltage VIN in a hybrid vehicle or an electric vehicle and supplies power to an auxiliary battery (not shown). The auxiliary battery supplies power supply voltage to in-vehicle electrical equipment such as audio equipment, air conditioner equipment, and lighting equipment.

  The switching power supply 5 obtains a predetermined voltage output by controlling on / off of a power transistor (not shown) at a predetermined switching frequency f. In the switching power supply 5, depending on the switching operation, voltage fluctuation occurs alternately between a high voltage and a low voltage at the switching frequency f depending on the internal connection. In addition, a current corresponding to the load current is alternately intermittently supplied to the power supply voltage VIN and the ground potential GND to cause a current fluctuation. Voltage fluctuations and current fluctuations due to the switching operation may be noise sources and cause noise to the output terminal.

  Such noise sources may propagate to the output terminal as conductive noise that wraps around the signal path or ground wiring, and may propagate to the output terminal as radiated noise radiated by electromagnetic coupling such as capacitive coupling or inductive coupling. . Here, as the radioactive noise, for example, it may occur with the voltage fluctuation of the internal connection. This is a case where an unexpected voltage fluctuation is caused to the circuit element at the coupling destination in accordance with the capacitive coupling due to the parasitic capacitance component interposed between the circuit elements or between the wirings. Further, it may occur with the current fluctuation of the power supply voltage VIN or the ground potential GND. This is a case where unexpected voltage fluctuations are caused in the power supply voltage VIN or the ground potential GND according to the back electromotive force due to the parasitic inductive component interposed in the wiring path of the power supply voltage VIN or the ground potential GND to be wired.

  The noise filter module 1 is connected to the output terminal VX of the switching power supply 5. The noise filter module 1 has a structure in which a choke coil L1 is provided in an output voltage path connecting the output terminal VX and the output terminal VO of the switching power supply 5, and a capacitor C1 is connected between the output terminal VO and the ground potential GND. Have. This is a so-called LC filter configuration. The noise filter module 1 can suppress the noise of the switching frequency f propagating through the signal path and its harmonic frequency among the conductive noise. Here, the switching frequency f in the switching power supply 5 is determined in accordance with the output power rating, the specification and rating of each component, and the like. For example, an in-vehicle switching power supply can be operated at several hundred kHz. For this reason, the switching frequency f and its harmonic frequency may overlap with the frequency band of the in-vehicle AM radio, and the noise filter module 1 is provided to suppress conductive noise propagating in the signal path in these bands. Can do.

Further, in the noise filter module 1 of the first embodiment, a part of the choke coil L1 on the output terminal VO side and the capacitor C1 are arranged so as to be located outside the metal housing 3. Thereby, since the metal housing 3 has an electromagnetic shielding effect, it is possible to suppress the propagation of the radioactive noise generated by the switching operation in the metal housing 3 to the output terminal VO.

According to the noise filter module 1 of the first embodiment, the choke coil L1 is disposed such that a part of the choke coil L1 on the output terminal VO side and the capacitor C1 are located outside the metal housing 3. For this reason, the output terminal VO that is the connection point between the choke coil L1 and the capacitor C1, that is, the portion of the conductive bar 11 that will be described later that protrudes from the magnetic core 13 toward the output terminal VO is shielded by the metal casing 3. . Thereby, propagation of radioactive noise to the output terminal VO is suppressed. It can suppress that radioactive noise mixes in an output voltage.

  Next, the shape / structure which is the module configuration of the noise filter module 1 will be described. FIG. 2 is an exploded perspective view of the noise filter module 1. FIG. 3 is a perspective view of the noise filter module 1. FIG. 3A is a perspective view in a molded state, and FIG. 3B is a perspective view in a state in which an internal structure is seen through. In the drawing, a part of the drawing is omitted from the configuration of the mounting substrate 17.

An output voltage path connecting the output terminal VX and the output terminal VO of the switching power supply 5 shown in FIG. The conductive bar 11 has a substantially columnar shape, and is formed of a metal material such as chromium molybdenum steel or carbon steel. Anchor portions 11c are formed on both sides in the axial direction across the center portion 11b, and bolt portions 11a are formed on both outer end portions thereof. The bolt part 11a is a bolt structure provided with a male screw, and has the shape of a stud bolt. One of the bolt parts 11a (the right side in FIG. 2) is connected to the output terminal VX of the switching power supply 5 provided in the metal casing 3. The other bolt portion 11a (left side in FIG. 2) is an output terminal VO, and is connected to a subsequent electronic device or the like. The axial center of the bolt part 11a, the axial center of the central part 11b, and the axial center of the anchor part 11c are arranged in the same straight line, and the conductive bar 11 is linearly formed of a single metal member. . The cross section seen from the axial direction of the center part 11b and the anchor part 11c is a concentric circle centering on the shaft center, and the diameter of the anchor part 11c is formed larger than the diameter of the center part 11b.

  The magnetic core 13 is formed in a hollow cylindrical shape having a hollow portion 13a, and is formed of a magnetic material such as ferrite, for example. In addition, slits 13b that are cut out by passing through in the radial direction in parallel to the axial direction are provided, and a part of the path that goes around in the circumferential direction is discontinuous. This is a so-called core gap, and the magnetic resistance in the magnetic core 13 is adjusted to prevent magnetic saturation. The conductive bar 11 passes through the hollow portion 13a of the magnetic core 13, and the choke coil L1 is configured by disposing the inner side surface of the hollow portion 13a and the central portion 11b of the conductive bar 11 so as to face each other. By adjusting the width of the slit 13b, the magnetic resistance is adjusted to suppress magnetic saturation, and the inductance of the choke coil L1 necessary for removing the noise component is secured.

  Here, the axial direction of the conductive bar 11 corresponds to a penetration direction penetrating the magnetic core 13.

  Electromagnetic shielding plates 15 are disposed on both end surfaces of the magnetic core 13 in the penetrating direction. Similarly to the magnetic core 13, the electromagnetic shielding plate 15 is formed in an annular shape having a hollow portion 15a, and the conductive bar 11 penetrates the hollow portion 15a. The electromagnetic shielding plate 15 is formed of a conductive metal material such as copper, nickel, or iron, for example, or is formed of a conductive paint or a conductive polymer film containing powder or foil of the metal material. Further, in order to prevent contact with the conductive bar 11, the diameter of the hollow portion 15a is adjusted. The electromagnetic shielding plate 15 has an effect of electrically shielding the conductive bar 11 penetrating the hollow portion 13 a of the magnetic core 13. This has the effect of suppressing the capacitive coupling to the conductive bar 11 and suppressing the propagation of radioactive noise propagating from the conductive bar 11 to the outside. At the same time, radioactive noise propagating from the outside to the conductive bar 11 can also be suppressed. In this embodiment, the electromagnetic shielding plates 15 are provided on both end faces of the magnetic core 13, but may be provided on one end face.

The pedestal 21 has a through hole 21a into which a screw (not shown) for fixing the molded portion 23 (described later in FIG. 3A) in which the noise filter module 1 is molded to the metal housing 3 is inserted. It is a cylindrical metal member. The pedestal portion 21 is disposed at both left and right end portions of the conductive bar 11 in the flange portion 23 b (described later in FIG. 3A) of the mold portion 23.

  The mounting substrate 17 connects the conductive bar 11 and the pedestal 21. The mounting substrate 17 includes a first fixing portion 31 at the center, second fixing portions 33 at both ends, and a connecting portion 35 positioned between the first fixing portion 31 and the second fixing portions 33 at both ends. The 1st fixing | fixed part 31, the 2nd fixing | fixed part 33, and the connection part 35 are formed with the metal material (for example, brass, copper, etc.) with favorable electroconductivity. The first fixing portion 31 includes an arcuate trunk portion 31 a along the outer peripheral surface of the anchor portion 11 c of the conductive bar 11 and linear ribs 31 b extending from both end portions of the trunk portion 31 a toward the connection portion 35. The second fixing portion 33 includes an arcuate trunk portion 33 a along the outer peripheral surface of the pedestal portion 21 and a linear rib 33 b extending from the end portion of the trunk portion 33 a toward the connection portion 35. The trunk portion 31a has an arc shape covering the half circumference of the anchor portion 11c and the trunk portion 33a of the pedestal portion 21. The ribs 31 b and 33 b are provided to extend in a direction connecting the anchor portion 11 c and the pedestal portion 21, that is, in a direction substantially orthogonal to the axial direction of the conductive bar 11. The connecting portion 35 has a rectangular plate shape that is solidified for each chip capacitor 37. The rib 31b and the connecting portion 35, and the rib 33b and the connecting portion 35 are provided with slits 17a between them, and the relative positions are fixed by an insulating material such as a resin material. That is, the rib 31b and the connection part 35, and the rib 33b and the connection part 35 form a land region where each terminal of the chip capacitor 37 is fixed by soldering or the like. The body part 31a is fixed to the anchor part 11c, and the body part 33a is fixed to the base part 21 by welding or the like. Four chip capacitors 37 are mounted between the first fixing portion 31 and each second fixing portion 33. Two sets are mounted in parallel, with two chip capacitors 37 connected in series as one set. Here, the anchor portion 11c to which the first fixing portion 31 is fixed is the output terminal VO, and the ground potential GND is supplied to the pedestal portion 21 to which the second fixing portion 33 is fixed. The chip capacitor 37 constitutes the capacitor C1.

  The mounting substrate 17 can be formed by the following processes, for example. First, a metal flat plate is punched by punching or the like, and the first fixing portion 31 and the second fixing portion 33 that are still in a flat plate state are planned, the member that the first fixing portion 31 is planned and the second fixing A member in which the connection portion 35 is planned and the member in which the connection portion 35 is scheduled is formed between the members in which the portion 33 is planned, and a flat plate member in a state where they are cross-linked with a thin metal wire. Next, the first fixing part 31 and the second fixing part 33 are formed into an arc shape by press working or the like. Next, after mounting the chip capacitor 37, the first fixing portion 31 and the connecting portion 35, and the second fixing portion 33 and the connecting portion 35 are connected by an insulating member such as an epoxy resin. Thereafter, the cross-linked portion of the fine metal wire is divided.

  FIG. 3 shows a mold part 23 in which the assembled noise filter module 1 is molded with a thermosetting resin (see FIG. 3A). FIG. 3B shows the internal configuration through the mold part 23. The thermosetting resin is used so as not to apply excessive pressure to the magnetic core 13. Phenol resin, epoxy resin, unsaturated polyester, etc. are used.

  The mold part 23 includes a core part 23a and a flange part 23b. The core portion 23a has a shape in which a magnetic core 13 through which the conductive bar 11 passes is molded into a cylindrical shape together with the conductive bar 11 with the penetrating direction as an axis. The flange portion 23b is formed by exposing the anchor portion 11c on the output terminal VO side of the conductive bar 11, the mounting substrate 17, and the pedestal portion 21 by exposing both end surfaces in the axial direction of the bolt portion 11a (output terminal VO) and the pedestal portion 21. Molded as a rectangular surface orthogonal to the direction.

As shown in FIG. 4, the mold portion 23 is attached in a state where the end surface (inner end surface) of the flange portion 23 b on the core portion 23 a side faces the outer end surface of the metal housing 3. The mold part 23 is attached to the metal case 3 by being screwed into the metal case 3 with screws, bolts or the like (not shown) through the opening of the pedestal part 21. Thereby, since the both end surfaces of the flange part 23b and the metal housing | casing 3 are attached closely, the noise filter module 1 can be reliably fixed to the metal housing | casing 3 and attached. For the attachment, a general fixing method such as caulking or welding can be used in addition to screwing.

Here, the chip capacitor 37 (capacitor C1) is molded in the flange portion 23b. Further, the magnetic core 13 is molded in the core portion 23a up to the intermediate region (region (2) in FIG. 4), and the remaining region is molded in the flange portion 23b (region in FIG. 4). (1)). When the mold portion 23 is fixed to the metal housing 3, the inner end surface of the flange portion 23 b is fixed in a state of being in close contact with the outer end surface of the metal housing 3. At this time, the chip capacitor 37 (capacitor C <b> 1) is disposed on the flange portion 23 b, and the flange portion 23 b is disposed outside the metal housing 3. Further, the end (outer side end) of the region (1) of the magnetic core 13 is disposed on the flange portion 23b, and the conductive bar 11 protrudes outward from the outer end of the magnetic core 13. (Output terminal VO) is disposed outside the metal housing 3. For this reason, the conductive bar 11 (output terminal VO) protruding from the outer side end of the region (1) of the chip capacitor 37 (capacitor C1) and the magnetic core 13 due to the electromagnetic shielding effect by the metal casing 3 Is suppressed, and the propagation of radiated noise to the chip capacitor 37 (capacitor C1) and the output terminal VO is suppressed. Further, voltage fluctuations that enter the chip capacitor 37 (capacitor C1) via the ground potential GND are also suppressed, and conduction noise is suppressed from propagating to the chip capacitor 37 (capacitor C1) and the output terminal VO. The ground potential GND of the chip capacitor 37 (capacitor C1) is connected to the metal casing 3 via the pedestal 21. Since the impedance of the metal casing 3 is sufficiently low, grounding due to conductive noise is caused. This is because voltage fluctuation of the potential GND is suppressed.

  5A, 5 </ b> B, and 5 </ b> C are views showing a cross-sectional shape of the mold portion 23. 5A shows a cross section in the penetration direction, and FIGS. 5B and 5C show the surface shapes of the BB cross section and CC cross section shown in FIG. 5A, respectively. In the drawing, FIG. 5C is shown with a part of the configuration of the mounting substrate 17 omitted.

  As shown in FIG. 5A, in the conductive bar 11, the anchor portion 11c having a diameter larger than that of the bolt portion 11a is molded with the outer end surface 11c2 of the mold portion 23 exposed. And when connecting to the terminal of the electronic device of a front | former stage or a back | latter stage through the volt | bolt part 11a, the outer end surface 11c2 functions as a seat part. That is, in the connected state, a large contact area between the terminal of the electronic device and the conductive bar 11 can be ensured. Thereby, contact resistance can be made low and the heat_generation | fever etc. in a connection site | part can be reduced in the mold part 23 through which a large current flows.

  Moreover, the diameter W1 of the anchor part 11c is larger than the diameter W2 of the center part 11b. Accordingly, when an external force is applied to the conductive bar 11 so as to move in the penetrating direction, the relative movement in the penetrating direction of the conductive bar 11 with the resin material filled in the mold portion 23 is caused by the anchor portion 11c. Regulated by. For example, when an external force is applied to the conductive bar 11 so as to move in the left direction in the figure, the inner end surface 11c1 on the center part 11b side of the anchor part 11c on the right side in the figure functions as an anchor. Similarly, when an external force is applied to the conductive bar 11 so as to move in the right direction in the figure, the inner end face 11c1 on the center part 11b side of the anchor part 11c on the left side in the figure functions as an anchor. In this case, the mounting substrate 17 also functions as a member that restricts movement in the penetration direction. Unlike the shape of the other parts of the conductive bar, the shape when viewed from the penetration direction of the anchor portion 11c and the mounting substrate 17 spreads in the direction perpendicular to the penetration direction, and this shape penetrates opposite to the resin material. This is because it becomes resistance to movement in the direction.

When an external force that rotates the conductive bar 11 in the circumferential direction is applied, the relative movement in the circumferential direction of the conductive bar 11 between the resin material filled in the mold part 23 is caused by the mounting substrate 17. Be regulated. The case where an external force that rotates the conductive bar 11 in the circumferential direction is applied, for example, when an electronic device is connected to the conductive bar 11 or when vibration is applied during use after being connected. is there. As shown in FIGS. 5B and 5C, since the cross-sectional shapes of the central portion 11b and the anchor portion 11c of the conductive bar 11 are both circular, the movement of the conductive bar 11 in the circumferential direction when an external force is applied. It is easy to produce. However, as shown in FIG. 5C, the substrate surfaces of the first fixing portion 31, the second fixing portion 33, and the connecting portion 35 (FIG. 2) of the mounting substrate 17 are filled with the resin material filled in the circumferential direction. Opposite. For this reason, since the opposing surface of the mounting substrate 17 becomes resistance with respect to the circumferential direction, the relative movement of the conductive bar 11 in the circumferential direction between the resin material filled in the mold part 23 is restricted. . Further, since the second fixing portion 33 of the mounting substrate 17 is fixed to the pedestal portion 21, the pedestal portion 21 also opposes the resin material toward the circumferential direction and becomes a resistance in the circumferential direction, so Regular movements. Further, since the mounting substrate 17 fixed to the conductive bar 11 in the anchor portion 11c is also fixed to the pedestal portion 21, if the pedestal portion 21 is fixed to the metal casing 3, the circumference of the conductive bar 11 will be described. Movement in the direction is restricted.

  FIG. 6 is a circuit diagram of a second embodiment according to the present application. As an example of the output noise reduction device, a case where a π-type filter module 1A is provided instead of the noise filter module 1 (see FIG. 1) in the first embodiment will be described. In addition to the configuration of the noise filter module 1 of the first embodiment, the π-type filter module 1A includes a capacitor C2 in the module. The same configurations as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and description thereof will be omitted below.

The π-type filter module 1 </ b> A is connected to the output terminal VX of the switching power supply 5 as in the case of the noise filter module 1. In addition to the choke coil L1 provided on the output voltage path connecting the output terminal VX and the output terminal VO, the π-type filter module 1A includes capacitors C1 and C2 between each terminal of the choke coil L1 and the ground potential GND. It is a configuration provided. Further, the choke coil L1 and the capacitors C1 and C2 are arranged so as to be located outward from the metal casing 3A.

  As in the case of the noise filter module 1 of the first embodiment, the π-type filter module 1A of the second embodiment propagates radiated noise and conductive noise caused by the switching operation of the switching power supply 5 to the output terminal VO. Suppress.

That is, in the choke coil L1 constituting the π-type filter module 1A, the conductive bar 11 projecting from both ends of the magnetic core 13 is outward from metal housing 3A, electromagnetic shielding effects of metal housing 3A Thus, electromagnetic coupling is suppressed. As a result, propagation of radioactive noise to this portion of the conductive bar 11 is suppressed.

Further, the propagation of radioactive noise due to electromagnetic coupling is also suppressed for the capacitors C1 and C2 constituting the π-type filter module 1A. This is because capacitors C1, C2 are electromagnetic coupling is suppressed by electromagnetic shielding effect of the metal housing 3A located outward from metal housing 3A. In addition, wraparound of voltage fluctuations via the ground potential GND is also suppressed. The ground potential GND supplied to the capacitors C1 and C2 is supplied from the metal casing 3A via the pedestal portion 21. Since the metal casing 3A has a wide plate shape, the impedance is sufficiently high. Because it is low. Since the impedance is low, it is possible to suppress voltage fluctuations from being supplied to the supplied ground potential GND, and it is possible to maintain a stable ground potential GND in which conductive noise is suppressed.

  As a result, the radiated noise and the conductive noise generated with the switching operation of the switching power supply 5 are both suppressed from propagating to the output terminal VO, and the noise is suppressed from propagating to the output voltage.

  Next, the shape and structure, which is the module configuration of the π-type filter module 1A, will be described. FIG. 7 is a perspective view of a state in which the internal structure of the resin-molded π-type filter module 1A is seen through. The same configurations as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and description thereof will be omitted below. In the drawing, a part of the drawing is omitted from the configuration of the mounting substrate 17.

  Two mounting boards 17 arranged in the first embodiment are arranged in the second embodiment. That is, in addition to the mounting substrate 17 (the mounting substrate of the first embodiment) that is fixed to the outer peripheral surface of the outer anchor portion 11c of the two anchor portions 11c provided in the conductive bar 11, the inner anchor It is also fixed to the outer peripheral surface of the portion 11c. The chip capacitor 37 mounted on the inner mounting board 17 is the capacitor C2 (see FIG. 6), and the chip capacitor 37 mounted on the outer mounting board 17 is the capacitor C1 (see FIG. 6). is there.

  The mold part 23A has a shape in which a flange part 23b (see FIG. 3A) extends in the axial direction instead of the core part 23a (see FIG. 3A) in the mold part 23 of the first embodiment. Yes. The pedestal portion 21A and the anchor portion 11c penetrating both the inner and outer end surfaces have a prismatic shape in which each end surface is exposed from the end surface of the mold portion 23A.

The mold part 23A is screwed with a screw, a bolt, or the like through the opening of the pedestal part 21A with the exposed end face of the pedestal part 21A in close contact with the outer end face of the metal housing 3A. Thereby, the mold part 23A that constitutes the π-type filter module 1A is disposed outside the metal housing 3A. Further, the bolt part 11a protruding from the mold part 23A on the inner side of the conductive bar 11 is inserted into the inside of the casing through an opening (not shown) of the metallic casing 3A. Here, the opening of the metal housing 3A is a smaller diameter opening than the opening 30 of the metal housing 3 (see FIG. 4). This is because the core portion 23a including the magnetic core 13 is inserted into the metal housing 3 in the first embodiment, whereas the bolt portion 11a protruding from the mold portion 23A is sufficient in the second embodiment. .

Since the entire molded portion 23A is disposed outside the metal housing 3A, the portions of the conductive bar 11 protruding from both ends of the magnetic core 13 constituting the choke coil L1, and the capacitor C1, The chip capacitor 37 constituting C2 is also disposed outside the metal housing 3A. Thereby, the electromagnetic coupling from the inside of the metal housing 3A to the conductive bars at both ends of the choke coil L1 and the capacitors C1 and C2 is suppressed. Transmission of radiated noise due to electromagnetic coupling to the output terminal VO (bolt portion 11a) is suppressed.

When the π-type filter module 1A is mounted, the inner end face of the pedestal portion 21A is fixed in a state of being in close contact with the outer end face of the metal housing 3A. Thereby, the capacitors C1 and C2 are connected to the ground potential GND via the base portion 21A and the metal casing 3A. Since the metal casing 3A has a stable ground potential GND, voltage fluctuations that flow from the ground potential GND to the output terminal VO via the capacitors C1 and C2 are suppressed. It is suppressed that conductive noise is transmitted to the output terminal VO (bolt portion 11a) due to the sneak voltage fluctuation.

  The relative movement in the penetration direction of the conductive bar 11 between the resin material filled in the mold part 23A due to the external force applied to the conductive bar 11 in the penetration direction is the same as in the first embodiment. Similarly, it is regulated by the anchor portion 11c. Further, the mounting substrate 17 functions as a member that restricts movement in the penetrating direction as in the first embodiment. In the second embodiment, since two mounting boards 17 are arranged at both end portions in the penetration direction, movement restriction in the penetration direction is strengthened compared to the first embodiment.

  The relative movement in the circumferential direction of the conductive bar 11 between the resin material filled in the mold part 23A due to the application of an external force in the circumferential direction to the conductive bar 11 is the same as in the case of the first embodiment. Similarly, it is regulated by the mounting substrate 17. In the second embodiment, since two mounting substrates 17 are arranged at both end portions in the penetration direction, movement restriction in the circumferential direction is strengthened compared to the first embodiment.

Moreover, as for the mold part 23A, the thickness of the conductive bar 11 in the penetrating direction is the combined thickness of the core part 23a and the flange part 23b in the mold part 23 of the first embodiment, and this part is the thickness of the metal casing 3A. Project outward. However, considering the size of the metal casing 3A in which the electronic device such as the switching power supply 5 is accommodated, the thickness of the mold portion 23A protruding outward from the metal casing 3A is the same as that in the first embodiment. Similarly, it can be said that it is very small. Compared with the case where the π-type filter module 1A is built in the metal casing 3A, an increase in mounting volume can be suppressed to a slight extent.

FIG. 8 shows a configuration of the noise filter module 1 of the third embodiment according to the present application. The circuit configuration is the same as the noise filter module 1 (see FIG. 1) of the first embodiment, but the shape and structure are different. FIG. 8 shows the structure of the mounting substrate 17B, as viewed from the direction of attachment to the metal housing 3B. FIG. 9 is a perspective view of the assembled internal configuration. FIG. 10 is a view showing a cross-sectional structure in a state of being attached to the metal casing 3B. FIG. 11 is a perspective view of the noise filter module 1 in a molded state. The same configurations as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and description thereof will be omitted below.

As shown in FIG. 8, the mounting board 17B is different in shape from the mounting board 17 of the first embodiment. Each of the first fixing portion 31B, the second fixing portion 33B, and the connecting portion 35B has a flat plate shape and is formed of a metal material having good conductivity (for example, brass, copper, etc.). The mounting board 17B has a symmetrical shape divided by the first fixing portion 31B. Each first fixing portion 31B has a shape in which a tip end portion covering the left half circumferential surface or the right half circumferential surface of the outer end surface of the anchor portion 11Bc of the conductive bar 11B is cut out in a semicircular shape. The anchor portion 11Bc has a shape in which cylinders of different diameters, each having a short cylindrical shape on the outer side in the penetrating direction and an enlarged cylindrical shape on the inner side, are stacked in two stages. The first fixed portion 31B covers the outer end surface of the columnar shape on the enlarged diameter side of the anchor portion 11Bc and is fixed by spot welding (indicated by a black circle on the first fixed portion 31B) or the like. The semi-circular inner diameter side of the first fixed portion 31B has a short-diameter columnar shape in the anchor portion 11Bc, and further a short-diameter bolt portion 11Ba protrudes outward in the penetration direction. When the second fixing portion 33B is attached to the metal casing 3B, a through hole 33Ba for inserting a bolt or the like is opened. The connection part 35B has the same configuration as the connection part 35 of the first embodiment. Each chip capacitor 37 has a rectangular plate shape separated into pieces, and is disposed between the first fixed portion 31B and the second fixed portion 33B, and the chip capacitor 37 is mounted thereon. 9 and 10, the mounted chip capacitor 37 is resin-molded with a primary mold 38.

  As shown in FIG. 10, unlike the conductive bar 11 of the first embodiment, the conductive bar 11B does not include an anchor portion on the inward side. In addition, a terminal portion 11Bd is provided instead of the inward bolt portion 11a. The terminal portion 11Bd has a wide plate-like rectangular shape and has a connection hole at the center. The conductive bar 11B is disposed through the magnetic core 13 and the electromagnetic shielding plate 15 as in the first embodiment. The electromagnetic shielding plates 15 are disposed on both end surfaces of the magnetic core 13.

The mounting substrate 17B molded by the molding part 23B is attached to the metal housing 3B by being screwed with a bolt or the like. The metal housing 3B has a protruding portion 3Ba that protrudes outward so as to be in close contact with the second fixing portion 33B in accordance with the position and diameter of the through hole 33Ba of the mounting substrate 17B. The mold part 23B has the through holes 33Ba and the peripheral second fixing parts 33B at both ends so that the second fixing part 33B of the mounting substrate 17B is attached in close contact with the metal housing 3B at the convex part 3Ba. Opened to be exposed. The diameter of the opening at this time is such that the bolt for screwing or the like or the convex portion 3Ba does not interfere with the flange portion 23Bb. Then, the convex portion 3Ba is inserted into the opening of the mold portion 23B, and is screwed in a state where the convex portion 3Ba is in close contact with the exposed second fixing portion 33B. For the attachment, a general fixing method such as caulking or welding can be used in addition to screwing.

As shown in FIG. 11, the mold part 23B includes a core part 23Ba and a flange part 23Bb. The core portion 23Ba has a shape in which the magnetic core 13 through which the conductive bar 11B passes is molded in a cylindrical shape together with the conductive bar 11B with the penetration direction as an axis. The flange portion 23Bb has a rectangular surface shape orthogonal to the penetrating direction, and the anchor portion 11Bc of the conductive bar 11B and the mounting substrate 17B are molded. Similarly to the case of the first embodiment (see FIG. 4), the magnetic core 13 has a conductive bar 11B (output terminal VO) protruding from the outer side end protruding outward of the metal housing 3B. It is molded to the flange portion 23Bb. From the outer side end portion of the flange portion 23Bb, a part of the anchor portion 11Bc of the short diameter cylinder and the bolt portion 11Ba protrude.

Here, the chip capacitor 37 (capacitor C1) is molded in the flange portion 23Bb. The flange portion 23Bb is disposed outside the metal housing 3B. For this reason, a conductive bar 11B (output terminal VO) and a chip capacitor 37 (capacitor C1) protruding from the outer end of the magnetic core 13 are disposed outside the metal housing 3B. As a result, the electromagnetic coupling from the inside of the metal housing 3B to the conductive bar 11B (output terminal VO) and the chip capacitor 37 (capacitor C1) is suppressed. In addition, since the ground potential GND connected to the chip capacitor 37 (capacitor C1) is supplied from the metal casing 3B, voltage fluctuations that flow into the chip capacitor 37 (capacitor C1) via the ground potential GND are also suppressed. . Therefore, it is possible to suppress both radiated noise and conductive noise to the output terminal VO.

  In the noise filter module 1 according to the third embodiment, the pedestal portion 21 is unnecessary as compared with the first embodiment. Further, in the process of forming the mounting substrate 17B, the process of forming the first fixing part 31 and the second fixing part 33 in the arc shape, which is necessary in the first embodiment, becomes unnecessary. Thereby, manufacturing cost can be reduced.

Further, as in the case of the first embodiment, the relative movement of the conductive bar 11B in the penetration direction and the circumferential direction is restricted. This is because the conductive bar 11B is provided with an anchor portion 11Bc whose diameter is larger than that of the bolt portion 11Ba, and the shape when viewed from the penetrating direction is different from the shapes of other portions. Further, the mounting substrate 17B also regulates the relative movement of the conductive bar 11B with respect to the penetration direction and the circumferential direction. This is because the shape of the mounting substrate 17B viewed from the penetrating direction and the circumferential direction becomes resistance to the respective directions. Further, the mounting board 17B is fixed to the metal casing 3B, and movement of the conductive bar 11B in the circumferential direction is restricted.

FIG. 12 shows the configuration of the noise filter module 1 of the fourth embodiment according to the present application. The circuit configuration is the same as the noise filter module 1 (see FIG. 1) of the first embodiment, but the shape and structure are different. FIG. 12 shows the structure of the mounting substrate 17 </ b> C as viewed from the direction of attachment to the metal housing 3. For example, printed wiring such as copper is formed on a hard rectangular printed circuit board obtained by processing epoxy resin or the like. A through hole 17Ca into which the bolt part 11a of the conductive bar 11 is inserted is opened at the center. Through holes 17Cb into which the pedestals 21 are inserted are opened on the left and right sides of the through holes 17Ca.

  On the surface of the mounting substrate 17C, the conductive wiring 39a that surrounds the outer periphery of the through hole 17Ca and goes from the through hole 17Ca to the through hole 17Cb on the left and right, and the conductive wiring 39b that surrounds the outer periphery of the through hole 17Cb and goes from the through hole 17Cb to the through hole 17Ca. And conductive wiring 39c sandwiched between conductive wiring 39a and conductive wiring 39b. Further, as illustrated in the cross-sectional view of the through hole 17Cb in FIG. 13, a conductive wiring 39d is formed on the back surface of the mounting substrate 17C so as to surround the outer periphery of each of the through holes 17Ca and 17Cb. A slit 17Cc is provided between the conductive wiring 39a and the conductive wiring 39c, and between the conductive wiring 39b and the conductive wiring 39bc. Chip capacitors 37 are mounted between the conductive wiring 39a and the conductive wiring 39c and between the conductive wiring 39b and the conductive wiring 39c, respectively, across the slit 17Cc. The conductive wiring 39a and the conductive wiring 39c sandwiching the slit 17Cc, and the conductive wiring 39b and the conductive wiring 39c each form a land region for mounting the chip capacitor 37 by soldering or the like. Between the conductive wiring 39a and the conductive wiring 39b, two sets of two chip capacitors 37 connected in series are connected in parallel.

  FIG. 13 shows an AA cross-sectional view of the through hole 17Cb. A cylindrical conductive wiring 39e is formed in the through hole 17Cb so as to cover the inner surface. The cylindrical conductive wiring 39e is connected to the conductive wiring 39b on the front surface of the mounting substrate 17C and the conductive wiring 39d on the back surface. Although not shown, the inner surface of the through-hole 17Ca is similarly covered with a cylindrical conductive wiring, and the cylindrical conductive wiring is connected to the conductive wiring 39a on the front surface and the conductive wiring 39d on the back surface of the mounting substrate 17C. The conductive bar 11 is fitted into the through hole 17Ca, and the pedestal portion 21 is fitted into the through hole 17Cb and fixed thereto. Further, the inserted conductive bar 11 and pedestal portion 21 are connected to the conductive wiring 39a or 39b on the front surface of the mounting substrate 17C and the conductive wiring 39d on the back surface by soldering or the like. Thereby, firm fixation and sufficient conduction can be achieved. Here, the outer end face of the anchor portion 11c of the conductive bar 11 is in close contact with the mounting substrate 17C. For attaching the conductive bar 11 and the pedestal 21 to the through holes 17Ca and 17Cb, a general fixing method such as caulking or welding can be used in addition to press-fitting.

The point where the magnetic core 13 and the electromagnetic shielding plate 15 are attached to the conductive bar 11 to which the mounting substrate 17C is fixed, the point where the whole is molded, the attachment of the molded part to the metal casing , etc. The configuration is the same as in the case of the first embodiment. Therefore, the propagation of the radiated noise and the conductive noise due to electromagnetic coupling such as capacitive coupling and inductive coupling and the routing of the ground wiring is suppressed to the mounting substrate 17C and the conductive bar (output terminal VO), and the noise is suppressed. In addition, the effects such as that the movement of the conductive bar 11 in the circumferential direction and the penetration direction can be restricted by providing the mounting substrate 17C are the same as in the case of the first embodiment.

  According to the mounting substrate 17C of the fourth embodiment, the inner surface of the through hole 17Cb is covered with metal to form the cylindrical conductive wiring 39e, and the cylindrical conductive wiring 39e is conductive on the front and back surfaces of the mounting substrate 17C. The wirings 39b and 39d are connected. Therefore, if the pedestal portion 21 is inserted into the through hole 17Cb, it can be connected to the conductive wirings 39b and 39d on the front surface and the back surface of the mounting substrate 17C to be conductive. The same applies to the through hole 17Ca. That is, the conductive wiring on the front surface and the back surface of the mounting substrate 17C is connected by the cylindrical conductive wiring covering the inner surface of the through-hole 17Ca, so that the conductive bar 11 can be electrically connected to the front surface and the back surface of the mounting substrate 17C. . Thus, one end of the chip capacitor 37 connected in series with the conductive bar 11 and the other end of the chip capacitor 37 connected in series with the pedestal 21 are connected, and the chip capacitor 37 connected in series is grounded to the output terminal VO. It can be connected between the potential GND.

  When the inner side surface of the through hole is not covered with the cylindrical conductive wiring, the conductive wiring 39b and 39d cannot be electrically connected only by inserting the pedestal into the through hole. For this reason, the pedestal portion is provided with a flange portion having an enlarged diameter in a portion protruding from the through hole to the front and back surfaces of the substrate in a state of being inserted into the through hole, and the conductive wiring 39b on the front surface and the back surface of the mounting substrate 17C in the flange portion. It was necessary to establish conduction with 39d. In order to use both ends of the pedestal portion as flange portions, the configuration of the pedestal portion has to be a two-member configuration of a bolt-shaped member and a nut-shaped member, leading to an increase in the number of parts. Further, when assembling, it is necessary to first insert a bolt-shaped member into the through hole, and then connect the nut-shaped member to the bolt-shaped member, which is complicated.

  On the other hand, in the fourth embodiment, only by inserting the columnar pedestal portion 21 into the through hole 17Cb, the conductive wirings 39b and 39d on the front surface and the back surface of the mounting substrate 17C can be connected and conductive. . It is possible to reduce the number of parts and improve the efficiency of assembly work.

  In addition, the cylindrical conductive wiring is formed by covering the entire inner surface of the through holes 17Ca and 17Cb with metal. For this reason, it is possible to secure a contact area sufficient to establish conduction with the conductive bar 11 and the pedestal portion 21, and to reduce the contact resistance.

  Since the noise filter module 1 of the fourth embodiment is composed of one mounting board 17C, the number of parts and the assembly process are fewer than in the case of the first embodiment, and the manufacturing cost can be reduced. .

  FIG. 14 shows the configuration of the noise filter module 1 of the fifth embodiment according to the present application. The circuit configuration is the same as the noise filter module 1 (see FIG. 1) of the first embodiment, but the shape and structure are different. In other words, the mounting substrate 17 of the first embodiment is not provided, a lead type capacitor 41 such as a film capacitor or a multilayer ceramic capacitor is provided instead of the chip capacitor 37, and a pedestal portion 21D is provided instead of the pedestal portion 21. ing. Here, the lead type capacitor 41 is a general capacitor element having a lead wire as a terminal.

  FIG. 14 is an exploded perspective view. The pedestal portion 21D is a metal member obtained by processing a part of a cylindrical shape into a flat plate shape, and has a through hole through which a screw or the like is screwed. The lead type capacitor 41 is connected to the anchor portion 11c of the conductive bar 11 and the flat portion of the base portion 21D by welding such as soldering or resistance welding.

  In the fifth embodiment, the lead type capacitor 41 is directly connected to the conductive bar 11 and the pedestal portion 21D, and no mounting board is required. Further, the capacitor element used in the LC filter can be replaced with a general-purpose lead component instead of the surface mount component. As a result, the cost of parts can be reduced by reducing the number of parts and using inexpensive parts. In addition, about another structure and an effect, it is the same as that of 1st Embodiment.

  15 to 17 show a sixth embodiment according to the present application. This is a case where the T-type filter module 1B is provided. The magnetic core 14 (choke coil L2) is added to the configuration of the third embodiment (FIG. 8). Here, instead of the conductive bar 11B provided in the configuration of the third embodiment (FIG. 8), a conductive bar 11C is provided. FIG. 15 shows a circuit diagram, FIG. 16 shows an exploded perspective view of the main part, and FIG. 17 shows a perspective view of the module.

  The T-type filter module 1B shown in FIG. 15 has a configuration in which a choke coil L2 is added between a connection point between the choke coil L1 and the capacitor C1 of the noise filter module 1 of the first embodiment and the output terminal VO.

  As shown in FIG. 16, the magnetic core 14 is mounted on the outer surface side of the mounting board 17B in order to form the added choke coil L2. The inner surface of the magnetic core 14 is mounted so as to cover the anchor portion 11Cc of the conductive bar 11C. In this case, the anchor part 11Cc has a shape in which the length in the penetrating direction of the columnar shape of the short diameter is expanded in the anchor part 11Bc of the conductive bar 11B. FIG. 16 shows the configuration of a primary mold 38 in which a surface mounted chip capacitor (see FIG. 8) is resin-molded. Prior to a resin mold for constituting the module 23C shown in FIG. 17, a chip capacitor mounted for the purpose of protecting surface-mounted components is preceded by a primary mold 38.

  A portion of the anchor portion 11Cc that is covered with the magnetic core 14 is longer than the anchor portion 11Bc of the conductive bar 11B. For this reason, in the module 23 </ b> C shown in FIG. 17, the portion where the magnetic core 14 is mounted is molded by protruding outward from the flange portion 23 </ b> Cb.

  Here, the switching power supply 5 is an example of an electronic device. The output voltage is an example of an output signal. The output voltage path is an example of a conductive bar. The bolt portions 11a and 11Ba of the conductive bars 11, 11B, the bolt portions 111a, 112a, 113a, 115a of the conductive bars 111, 112, 113, 115 described later, and the terminal portions 113d, 114d of the conductive bars 113, 114 are connected. It is an example of a terminal and an output terminal. The magnetic cores 13, 131, 132, and 133 are examples of the first magnetic core, and the magnetic core 14 is an example of the second magnetic core. The mounting boards 17, 17B, and 17C are examples of the first mounting board and the second mounting board. In the second embodiment, the third fixing portion and the fourth fixing portion of the mounting boards 17, 17B, and 17C on the inner side are respectively the first fixing of the mounting boards 17, 17B, and 17C on the outer side. And the second fixing portion. Also, conductive bars 11, 11B, anchor portions 11c, 11Bc of conductive bars 112, 113, 114, 115 described later, anchor portions 112c, 113c described later, body portions 111b of conductive bars 111, 115 described later, 115b, a groove 115c described later of the conductive bar 115, and the mounting boards 17, 17B, and 17C are examples of the movement restricting portion.

As described above in detail, according to the noise filter module 1 of the first embodiment disclosed in the present application, the chip capacitor 37 (capacitor C <b> 1) is located outside the metal housing 3. Further, since a part of the magnetic core 13 on the output terminal VO side is outside the metal housing 3, a portion corresponding to the output terminal VO in the conductive bar 11 is located outside the metal housing 3. Thereby, the electromagnetic coupling between the capacitor C1 and the output terminal VO and the switching power supply 5 is suppressed from the metal casing 3. Propagation of radioactive noise caused by the switching operation to the capacitor C1 and the output terminal VO is suppressed.

Further, since the ground potential GND of the capacitor C1 accommodated in the flange portion 23b is supplied from the metal casing 3 via the pedestal portion 21, voltage fluctuations associated with the switching operation mixed in the ground potential GND are suppressed. The Since the metal casing 3 has a sufficiently low impedance, it is possible to suppress voltage fluctuations accompanying the flow of the transient operating current that occurs in association with the switching operation from passing through the metal casing 3. It is. Thereby, it is possible to suppress propagation of conductive noise from the ground potential GND to the output terminal VO via the capacitor C1.

Here, it has been described that the supply of the ground potential GND to the chip capacitor 37 (capacitor C <b> 1) is performed via the metal housing 3. However, the present application is not limited to this. Any configuration may be used as long as voltage fluctuation caused by the switching operation is prevented from flowing into the ground potential GND supplied to the capacitor C1. For example, in a ground line path through which an operating current that flows due to a switching operation passes, even if the impedance of the path is low, a voltage drop may occur depending on the flowing operating current, and voltage fluctuation may occur in the ground line path. is there. In addition, if there is a parasitic inductance component in the ground line path, back electromotive force is generated by electromagnetic induction according to the intermittent operation current, potential difference may occur in the ground line path, and voltage fluctuation occurs in the ground line path There is also. In order not to propagate the voltage fluctuation of the ground line path to the ground potential GND supplied to the capacitor C1, the ground potential GND should be supplied through a path having a sufficiently low impedance like the metal casing 3. It is an example. As another example, for example, a ground line path for supplying the ground potential GND to the switching power supply 5 and a ground line path for supplying the ground potential GND to the capacitor C1 are connected from the ground terminal at the base end supplying the ground potential GND. It is possible to branch and connect. As a result, the operating current flowing to the ground potential GND according to the switching operation flows through the ground line path branched from the ground line path that supplies the ground potential GND to the capacitor C1. The influence of the operating current on the ground potential GND supplied to the capacitor C1 can be eliminated. As a result, it is possible to prevent the voltage fluctuation of the ground potential GND due to the switching operation from flowing around.

Further, depending on the positional relationship between components in the metal housing 3 and the routing of the wiring, the magnitude and the degree of propagation of radioactive noise and conductive noise may differ. For this reason, in order to suppress noise, it is necessary to determine the positioning of the arrangement and the wiring by variously considering the arrangement and the routing of the wiring. On the other hand, by mounting the noise filter module 1 on the metal housing 3 as the mold part 23, it is possible to suppress noise without considering these arrangements and wiring routing. This is because the electronic device such as the switching power supply 5 and the noise filter module 1 are connected via the metal casing 3. In other words, the metal casing 3 can provide an electromagnetic shielding effect and reduce the resistance value of the ground potential to suppress the sneak in the voltage fluctuation. Therefore, it is not necessary to optimize the individual circuit arrangement and wiring routing in the metal housing 3 according to the noise situation at the output terminal VO and the specifications and ratings of the electronic device and the housing . According to the noise band to be suppressed, the effect can be obtained by using it for general purposes. It is possible to easily and easily suppress radiation noise and conductive noise mixed in the output signal for general purposes.

Further, the mold thickness of the flange portion 23 b of the mold portion 23 is defined by the thickness of the anchor portion 11 c or the pedestal portion 21. This thickness can be made very small in view of the size of the metal casing 3 in which electronic equipment such as the switching power supply 5 is accommodated. In the noise filter module 1 of the embodiment, the flange portion 23b protrudes outward from the metal housing 3 instead of being built in, but the thickness of the flange portion 23b is very small, and the noise filter module 1 is mounted on the metal housing. Compared with the case where it is built in the body 3, an increase in mounting volume can be suppressed to a slight extent.

  In addition, since the noise filter module 1 is configured by the mold part 23 filled with the mold resin, it is possible to ensure reliability with respect to the surrounding environment such as vibration, dust, and temperature. In particular, it is possible to improve reliability by applying it to an automobile application used in a harsh surrounding environment.

  In addition, by providing the electromagnetic shielding plates 15 on both end surfaces in the penetration direction of the magnetic core 13, the conductive bar 11 inserted through the magnetic core 13 can be shielded from the outside. Thereby, it is possible to suppress the propagation of radioactive noise from the conductive bar 11 to other electronic components or external electronic devices. At the same time, it is possible to prevent radioactive noise from being mixed into the conductive bar 11 from other electronic components or from the outside.

  In addition, the conductive bar 11 is provided with a bolt part 11a which is a connecting part for connecting an external member at both ends, and the straight line from one bolt part 11a to the other bolt part 11a is a single metal member. It is formed. Unlike a general configuration in which the conductive bar is composed of a plurality of members and a fixing member for fixing each of the conductive bars is also required, the contact resistance between the members can be reduced. In addition, the number of parts can be reduced and the assembling work can be simplified. Manufacturing cost can be reduced.

  Moreover, since each of the bolt part 11a, the center part 11b, and the anchor part 11c is formed in the column shape in the conductive bar 11, the conductive bar 11 is formed from one columnar base material by cold heading. be able to. Therefore, the conductive bar 11 can be easily manufactured.

  Further, by providing the conductive bar 11 with the anchor portion 11c having a diameter larger than that of the bolt portion 11a and the central portion 11b, when a force in the penetration direction is applied to the conductive bar 11, the conductive bar between the mold portion 23 and the conductive bar 11 is provided. The relative movement in the penetration direction of 11 can be controlled. In addition, since the mounting substrate 17 is fixed to the conductive bar 11 and the shapes of the mounting bar 17 are different from each other when viewed from the penetration direction, the mold portion 23 is also formed by the mounting substrate 17 when a force in the penetration direction is applied to the conductive bar 11. Relative movement in the penetration direction of the conductive bar 11 can be restricted. Furthermore, by providing the mounting substrate 17, when a circumferential force is applied to the conductive bar 11, the relative movement of the conductive bar 11 with respect to the mold part 23 in the circumferential direction is restricted. Can do.

  Moreover, by providing the bolt part 11a at both ends of the conductive bar 11, the molded part 23 in which the noise filter module 1 is molded is connected to the switching power source 5 without adding a member, and the output provided in the molded part 23 The terminal VO can be connected to an external electronic device. For example, when bolting is recommended when fixing the noise reduction device in applications such as automobiles, the conductive bar 11 includes the bolt portion 11a, so that it can be attached integrally. When fixing, additional parts such as a fixing member are not required, the number of work steps can be reduced, and the manufacturing cost can be reduced.

Moreover, the electromagnetic coupling between the capacitors C1 and C2 and the choke coil L1 constituting the π-type filter module 1A of the second embodiment disclosed in the present application is suppressed with the switching power supply 5. When the π-type filter module 1A is installed and attached outward from the metal casing 3A, the capacitors C1, C2 and the choke coil L1 housed in the mold part 23A are outward from the metal casing 3A. This is because they are arranged and electromagnetically shielded by the metal casing 3A.

Further, since the ground potential GND of the capacitors C1 and C2 accommodated in the mold portion 23A is supplied from the metal casing 3A via the pedestal portion 21A, it is accompanied by the operation of the switching power supply 5 mixed in the ground potential GND. Voltage fluctuation is suppressed. Since the metal casing 3A has a sufficiently low impedance, it is possible to suppress the voltage fluctuation accompanying the flow of the transient operating current that is caused by the operation of the switching power supply 5 from propagating to the metal casing 3A. This is because that. Thereby, wraparound of voltage fluctuation to the capacitors C1 and C2 via the ground potential GND is suppressed.

  By suppressing the electromagnetic coupling to the capacitors C1 and C2 and suppressing the wraparound of the voltage fluctuation via the ground potential GND, the propagation of the radiated noise and the conductive noise to the output terminal VO is suppressed.

  Further, in the π-type filter module 1A of the second embodiment, the two mounting substrates 17 are arranged on the conductive bar 11, so that the conductive bar 11 is relatively relative to the through direction and the circumferential direction as compared with the first embodiment. Movement can be further restricted.

The flange portion of the mold part 23A of the π-type filter module 1A of the second embodiment, the flange portion 23b of the first embodiment, but increases the thickness of the portion projecting outwardly of the metal housing 3A, switching The size of the metal casing 3A in which the electronic device such as the power source 5 is housed can be reduced to a small amount. Compared with the case where the π-type filter module 1A is built in the metal casing 3A, an increase in mounting volume can be suppressed to a slight extent.

  Further, in the noise filter module 1 of the third embodiment disclosed in the present application, the first fixing portion 31B and the second fixing portion 33B of the mounting substrate 17B have a flat plate shape. Unlike the first fixing portion 31 and the second fixing portion 33, the step of forming the mounting substrate 17B into an arc shape is not necessary. Thereby, manufacturing cost can be reduced.

  Further, in the noise filter module 1 of the fourth embodiment disclosed in the present application, the inner surface of the through hole 17Cb is covered with the cylindrical conductive wiring 39e connected to the conductive wirings 39b and 39d on the front surface and the back surface of the mounting substrate 17C. Therefore, by inserting the columnar pedestal portion 21 into the through hole 17Cb, the pedestal portion 21 and the conductive wirings 39b and 39d can be electrically connected. The same applies to the through hole 17Ca. By inserting the bolt part 11a of the conductive bar 11 into the through hole 17Ca, the conductive bar 11 and the conductive wirings 39a and 39d can be electrically connected. In addition, since the cylindrical conductive wiring covering the inner side surfaces of the through holes 17Ca and 17Cb is connected to the conductive bar 11 and the pedestal portion 21, a sufficient contact area can be secured to reduce conduction and contact resistance can be reduced. .

  In addition, unlike the first embodiment, the noise filter module 1 of the fifth embodiment disclosed in the present application does not have the mounting substrate 17, so that the number of parts can be reduced and the manufacturing process can be simplified, and the manufacturing cost can be reduced. Can be reduced.

In the second to sixth embodiments, configurations and operational effects that are not particularly mentioned have the same configurations and operational effects as those in the first embodiment.

Needless to say, the technology disclosed in the present application is not limited to the above-described embodiment, and various improvements and modifications can be made without departing from the spirit of the present invention.
For example, in the first embodiment, in addition to the chip capacitor 37 (capacitor C1) being located outward from the metal housing 3, a part of the magnetic core 13 on the output terminal VO side is accommodated in the flange portion 23b. The case where the portion related to the output terminal VO of the conductive bar 11 is located outside the metal housing 3 is illustrated. Thus, by utilizing the metal housing 3, it has been described to reduce the contamination of the radiation noise to suppress electromagnetic coupling between the interior of the metal housing 3 of 5 such as a switching power supply. However, the present application is not limited to this. Even the tip portion of the output terminal VO side of the magnetic core 13 is not protruded to the outside of the metal housing 3, positioned within the opening 30 of the conductive bar metal housing 3 which projects from the output terminal VO side If so, the portion of the conductive bar 11 related to the output terminal VO is shielded by the metal casing 3. Thereby, electromagnetic coupling can be suppressed and mixing of radioactive noise can be reduced. Further, even if the magnetic core 13 is located inward of the metal housing 3, a chip capacitor 37 (capacitor C1) is metallic chassis 3 from the outside or metal housing 3 of the opening 30 If it is located in, the noise filter module by which the chip capacitor 37 (capacitor C1) was shielded from the radioactive noise can be comprised. Here, the chip capacitor 37 to be shielded does not have to be all the capacitors C1 constituting the noise filter module. When a plurality of chip capacitors 37 are connected in series or in parallel, in series or in parallel the connected chip capacitor 37 at least one of the metallic casing 3 from the outside or metal housing 3 of the opening 30 of the If it is located in, it can show a shielding effect.

  Further, the entire mold part 23, or the flange part 23b with the chip capacitor 37 (capacitor C1), or the core part 23a or the flange part 23b with a part on the output terminal VO side of the magnetic core 13 is made of a metal member ( It is also possible to enclose with a metal wall. As a result, the chip capacitor 37 (capacitor C1) surrounded by the metal member (metal wall) and the conductive bar 11 relating to the output terminal VO protruding from the magnetic core 13 are electromagnetically shielded, so that the radiation noise is propagated. Can be suppressed. In this case, the portion to be subjected to electromagnetic shielding may be a region from the output terminal VO to at least a part of the chip capacitor 37 (capacitor C1). Thereby, electromagnetic coupling is suppressed and it can suppress that radioactive noise mixes in an output voltage.

  In the first embodiment, the case where a thermosetting resin is used as the resin for molding the noise filter module 1 has been described. However, a thermoplastic resin such as PPS (Polyphenylene Sulfide) or PBT (PolyButylene Terephthalate) is used. Needless to say, you can.

  In the second embodiment, the case where two mounting substrates 17 are used as an example of the configuration of the π-type filter module 1A has been described. However, the present application is not limited to this. At least one of the mounting boards 17 can be replaced with a mounting board 17B (FIG. 8) and a mounting board 17C (FIG. 12). Furthermore, a lead type capacitor such as a multilayer ceramic capacitor can be mounted instead of the mounting substrate.

  18A to 18E show other embodiments of the conductive bar. A conductive bar 111 shown in FIG. 18A includes a bolt part 111a and a body part 111b. The conductive bar 111 has a structure in which the central portion 11b of the conductive bar 11 of the first embodiment is not provided, that is, the anchor portion 11c of the first embodiment is not provided. Moreover, by providing the mounting substrate 17 shown in the first embodiment, movement in the penetration direction and the circumferential direction can be restricted.

  The conductive bar 112 shown in FIG. 18B has a bolt portion 112a, a central portion 112b, and an anchor portion 112c. The central portion 112b of the conductive bar 112 is formed in a flat plate shape. In the case of this conductive bar 112, a magnetic core having a rectangular inner wall as shown in FIG. 19 (for example, a U-shaped magnetic core 132 (see FIG. 19B)), If the magnetic core 133 (see FIG. 19C) is used, the distance from each surface of the central portion 112b of the conductive bar 112 to the inner surface of the magnetic core can be made uniform. Moreover, in order to form the center part 112b, it can shape | mold by crushing the center part 11b of the electrically conductive bar 11 illustrated in 1st Embodiment by a forge process etc.

  A conductive bar 113 illustrated in FIG. 18C includes a bolt portion 113a, a central portion 113b, an anchor portion 113c, and a terminal portion 113d. A terminal portion 113d is provided instead of the bolt portion 11a on one side (side connected to the switching power supply 5) in the conductive bar 11 of the first embodiment. The terminal portion 113d has a flat plate shape and is provided with a connection hole. The shape of the terminal portion 113d is the same as that of a general conductive bar, and the conductive bar 113 of the present invention can be applied to an existing electronic device.

  The conductive bar 114 shown in FIG. 18D has the same shape as the central portion 112b of the conductive bar 112 (see FIG. 18B) instead of the central portion 113b of the conductive bar 113 (see FIG. 18C). It is the structure provided with the center part 114b which has. As in the case of the conductive bar 112, it is convenient to use a U-shaped magnetic core 132 as shown in FIG. 19B or a separate magnetic core 133 as shown in FIG. 19C. As in the case of the conductive bar 113, the terminal portion 114d has a flat plate shape with a connection hole, and can be applied to an existing electronic device using a general conductive bar.

  The conductive bar 115 in FIG. 18E has a bolt part 115a and a body part 115b. The body part 115b has a groove part 115c formed inwardly. In addition to the body portion 115b having a larger diameter than the bolt portion 115a, the mold member enters the groove portion 115c, whereby relative movement in the penetration direction can be restricted. Furthermore, relative movement in the circumferential direction can be restricted by the groove 115c. Note that the shape is not limited to the groove shape as long as it has a shape that is recessed toward the inner diameter side of the body portion 115b instead of the groove portion 115c. By providing the above, the same effect can be obtained. Moreover, it is good also as a structure attached so that a hole may be a screw hole and a small volt | bolt which can be covered with a mold member protrudes from the trunk | drum 115b. Moreover, you may form the structure which becomes convex outward from the trunk | drum 115b by processing the trunk | drum 115b.

  FIGS. 19A to 19C show other embodiments of the magnetic core. A magnetic core 131 shown in FIG. 19A is a split magnetic core that combines a first core 131a and a second core 131b formed in a semi-annular shape to form a hollow portion 131c and a slit 131d. is there. A magnetic core 132 shown in FIG. 19B is a U-shaped magnetic core having a hollow portion 132c and a slit 132d. A magnetic core 133 shown in FIG. 19C is a split-type magnetic core in which a hollow portion 133c and a slit 133d are formed by combining the first core 133a and the second core 133b. In FIG. 19, slits 131d, 132b, and 133d are provided at one place on a magnetic path around which the magnetic flux of the magnetic core circulates.

  Further, the magnetic cores 13 and 131 to 133 are illustrated as an example, and the slits 13b and 131d to 133d are provided in parallel to the axis. However, the present application is not limited to this. The slits 13b and 131d to 133d are provided in order to prevent magnetic saturation by adjusting the magnetic resistance in the magnetic cores 13 and 131 to 133. Therefore, it goes without saying that depending on the physique of the magnetic core and the rating of the flowing current, it is possible to adopt a configuration that does not cause magnetic saturation without providing a slit. Moreover, about FIG. 19 (A) and (C), it can also be set as the structure provided with two slits in each connection part which combines two cores.

DESCRIPTION OF SYMBOLS 1 Noise filter module 1A pi type filter module 3, 3A, 3B Metal housing | casing 5 Switching power supply 11, 11B, 111, 112, 113, 114, 115 Conductive bar 11a, 11Ba, 111a, 112a, 113a, 115a Bolt part 11b 111b, 112b, 113b, 114b Central part 111b, 115b Body part 11c, 11Bc, 112c, 113c Anchor part 115c Groove part 11Bd, 113d, 114d Terminal part 11c1 Inner end face 11c2 Outer end face 13, 14, 131, 132, 133 Magnetic body Core 13a, 15a, 131c, 132c, 133c Hollow part 15 Electromagnetic shielding plate 17, 17B, 17C Mounting board 21, 21A, 21D Base part 23, 23A, 23B Mold part 23a, 23Ba Core part 23b, 23Bb Flange 30 Openings 31, 31B First fixed portions 33, 33B Second fixed portions 31a, 33a Body portions 31b, 33b Ribs 35, 35B Connection portion 37 Chip condenser 41 Lead type capacitors C1, C2 Capacitor L1 Choke coil VO Output terminal VX Output terminal of switching power supply 5

Claims (5)

An output noise reduction device that reduces noise mixed in an output signal from an electronic device housed in a metal housing ,
A conductive bar formed of a conductive material, with one end serving as a connection terminal connected to the output end of the electronic device, and the other end serving as an output terminal;
A first magnetic core formed of a magnetic material and having a through-hole through which the conductive bar passes; a conductive bar formed of a resin material excluding the connection terminal and the output terminal; and the first magnetic core. A mold part to mold,
A first fixing part molded by the mold part and fixed to the conductive bar between the first magnetic core and the output terminal; a second fixing part connected to the metal casing ; A first mounting substrate that connects a first fixing portion and the second fixing portion with a capacitive element;
The output noise reduction device, wherein electromagnetic coupling from the electronic device is separated from the output terminal to at least a part of a main body portion having a capacitive component of the capacitive element of the first mounting substrate.   A third fixing portion molded by the mold portion and fixed to the conductive bar between the first magnetic core and the connection terminal; a fourth fixing portion connected to the metal casing; 2. The output noise reduction device according to claim 1, further comprising: a second mounting substrate that connects a third fixing portion and the fourth fixing portion with a capacitive element. The connection terminal of the conductive bar is connected to the output end of the electronic device inside the metal casing, and the output terminal of the conductive bar passes through the opening of the metal casing through the conductive bar. in a state of being disposed outward from the metallic casing Te, at least a portion of the body portion having a capacitive component of the capacitive element of the first mounting substrate is positioned outward from the metal housing, or The output noise reduction device according to claim 1, wherein the output noise reduction device is located in an opening of the metal casing. The first magnetic core is located outward from a portion of at least the output terminal side the metal housing, or at least a part of said output terminal located in the opening of the metal housing The output noise reduction device according to claim 3.   5. The output noise according to claim 1, wherein an electromagnetic shielding plate is provided on at least one of the end faces of the first magnetic core in the penetrating direction of the conductive bar. Reduction device.

Images