Support structure for filter substrate and harmonic wave restraining device

Abstract

To allow even a large and heavy choke coil to be stably supported vertically inside a case.SOLUTION: A support structure supports a filter substrate 12 including a choke coil 201 having a coil body 211, coil winding, and a base portion 212, and a wiring board 124, inside a case 101. An inward extension portion 301 extending from a wall portion 101r of the case 101 to the inside of the case 101 is provided, and the wiring board 124 has an opening portion Q that penetrates through the front and back sides of the case 101 and allows the inward extension portion 301 to be inserted therethrough. The inward extension portion 301 passes through the opening portion Q and reaches the base portion 212, and the base portion 212 has an engagement portion 212a that engages with a tip portion 301a of the inward extension portion. The filter substrate 12 is supported on the wall portion 101r of the case 101 by the inward extension portion 301.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a support structure for a filter substrate and a harmonic suppression device. [Background technology]

[0002] In various electrical devices that contain harmonic generating sources such as motor inverters, inductance elements such as choke coils are used as filters to remove harmonics, which are noise. As the power consumption of the device increases, the size and weight of the choke coil also increases, which may result in restrictions on the placement of the choke coil.

[0003] For example, when a filter substrate having a choke coil, an electrical component mounted on a printed wiring board (a so-called bare board), is housed in a case, if the filter substrate is placed horizontally inside the case, it is possible to stably support the choke coil, which is a heavy object mounted on the top surface of the filter substrate.

[0004] However, in this case, an installation area large enough to accommodate the filter substrate laid flat (i.e., the bottom projection area) is required, and if the choke coil is enlarged, the filter substrate also becomes larger accordingly, and the installation area for the filter substrate also expands. This increases the internal bottom area of ​​the case, raising concerns that space efficiency may worsen. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 5483728 Summary of the Invention [Problem to be solved by the invention]

[0006] In contrast, by installing the filter substrate vertically (perpendicularly), it is possible to reduce the installation area (so-called footprint) of the filter substrate inside the case and to make effective use of the space inside the case.

[0007] Generally, the choke coil is joined to a wiring board at multiple points by soldering, and the wiring board is then fixed to the case, so that the choke coil is indirectly supported by the case via the wiring board.

[0008] When the filter board is installed vertically, the choke coil, which is large and heavy compared to the wiring board, is in an unbalanced cantilevered state, which puts stress on the wiring board supporting the choke coil, causing it to bend. In addition, the load due to the weight of the choke coil is concentrated on the soldered joint, making this joint prone to damage over long-term use.

[0009] In view of the above circumstances, an object of the present invention is to provide a filter substrate support structure and a harmonic suppression device that enable stable support in a vertical position even for a large and heavy choke coil. [Means for solving the problem]

[0010] In order to solve the above-mentioned problems, a support structure for a filter substrate according to one embodiment of the present invention is a support structure for a filter substrate that supports, inside a case, a filter substrate comprising: a wiring board having an electrical wiring pattern, a coil body, a coil winding wound around the coil body, and a base portion supporting the coil body, the base portion facing the wiring board, and a choke coil fixed to the wiring board with the coil winding connected to the electrical wiring pattern, the support structure for a filter substrate having an inward extension portion extending from a wall portion extending vertically of the case into the case, the wiring board having an opening through which the inward extension portion can be inserted, the inward extension portion passing through the opening to reach the base portion, the base portion having an engagement portion that engages with a tip portion of the inward extension portion, and the filter substrate being supported on the wall portion of the case by the inward extension portion.

[0011] A harmonic suppression device according to another embodiment of the present invention is a harmonic suppression device that is connected to a system line that connects an AC system and an electrical appliance, and reduces harmonic components of a current flowing through the system line, and includes a voltage converter connected to the system line, a controller that detects the harmonic components and controls the output voltage of the voltage converter so as to supply a compensation current of opposite phase to the harmonic components to the system line, a noise filter connected between the system line and the voltage converter, and reduces noise components based on the switching operation of the voltage converter, and a case that houses the voltage converter, the controller, and the noise filter, and the noise filter has the choke coil and the wiring board, and is supported by the support structure relative to the case. Effect of the Invention

[0012] According to the present invention, the choke coil on the filter board is directly supported by the vertically extending wall of the case, which reduces the load on the joint between the choke coil and the wiring board and on the wiring board, making it possible to support a filter board equipped with a large and heavy choke coil in a vertical position without stress. [Brief description of the drawings]

[0013] [Figure 1] 1 is a circuit diagram illustrating a circuit configuration of a harmonic suppression device according to a first embodiment of the present invention. [Diagram 2] 2 is a front view showing the arrangement of filter substrates inside a case of the harmonic suppression device according to the first embodiment. FIG. [Diagram 3] 3 is a cross-sectional view taken along line AA shown in FIG. 2. [Figure 4] 3 is a cross-sectional view taken along line BB in FIG. 2, showing a partial cross-section of the support structure for the filter substrate according to the first embodiment. [Diagram 5] 5 is a cross-sectional view taken along line CC shown in FIG. 4. [Figure 6] 5 is an enlarged cross-sectional view showing a modified example of the inward extension portion according to the first embodiment. FIG. [Figure 7] 10 is a front view showing the arrangement of filter substrates inside a case of a harmonic suppression device according to a second embodiment of the present invention. FIG. [Figure 8] 8 is a cross-sectional view taken along line DD in FIG. 7, showing a partial cross-section of a support structure for a filter substrate according to a second embodiment. FIG. [Figure 9] 9 is a cross-sectional view taken along line EE shown in FIG. 8. [Figure 10] 11A and 11B are cross-sectional views showing modified examples of the arrangement of filter substrates inside the case. [Figure 11] FIG. 11 is a partial cross-sectional view showing a modified example of the support structure of the filter substrate in accordance with the second embodiment. [Figure 12] 12 is a cross-sectional view taken along line FF shown in FIG. 11. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0015] The configuration of a harmonic suppression device 1 using a filter substrate 12 according to a first embodiment of the present invention will be described with reference to FIG.

[0016] The harmonic suppression device 1 according to the first embodiment is connected to system lines Lr, Ls, and Lt that connect an AC power source E and an air conditioner 2. The AC power source E is a power system or a power distribution system, and in the first embodiment, is a commercial three-phase AC power source rated at 200 V. The air conditioner 2 is an example of a load that generates harmonics during its operation.

[0017] The air conditioner 2 includes a rectifier circuit 21 , a DC reactor 22 , a smoothing capacitor 23 , a compressor inverter 24 , a compressor motor 25 , a blower inverter 26 , and a fan motor 27 .

[0018] The rectifier circuit 21 is, for example, a three-phase full-wave rectifier, and converts the AC voltage supplied through the system lines Lr, Ls, and Lt into a DC voltage by full-wave rectification. The DC output of the rectifier circuit 21 is connected to one input terminal of each of the compressor inverter 24 and the blower inverter 26 via a DC reactor 22, and the other output terminal of the rectifier circuit 21 is connected to the other input terminal of each of the compressor inverter 24 and the blower inverter 26. A smoothing capacitor 23 is connected between a power line connecting one output terminal of the rectifier circuit 21 via the DC reactor 22 to one input terminal of each of the inverters 24 and 26, and a power line connecting the other output terminal of the rectifier circuit 21 to the other input terminal of each of the inverters 24 and 26. The input terminals of each phase of the compressor motor 25 are connected to the output terminal of the compressor inverter 24, and the input terminals of each phase of the fan motor 27 are connected to the output terminal of the blower inverter 26. A permanent magnet synchronous motor can be used for the compressor motor 25 and the fan motor 27.

[0019] The compressor inverter 24 and the blower inverter 26 convert the DC voltage applied to the smoothing capacitor 23 into an AC voltage of a predetermined frequency by switching operation, and output this output voltage as a drive voltage for the compressor motor 25 and the fan motor 27. As a result, the compressor motor 25 and the fan motor 27 are driven at variable speeds, and the air conditioner 2 operates.

[0020] In the first embodiment, the input terminals of the compressor inverter 24 and the blower inverter 26 are commonly connected to the output terminal of the rectifier circuit 21, and the rectifier circuit 21 is configured as a common DC power supply for these inverters 24, 26. However, without being limited to this, it is also possible to provide a rectifier circuit serving as a DC power supply for the compressor inverter 24 and a rectifier circuit serving as a DC power supply for the blower inverter 26 separately, and to configure the DC power supplies for these inverters 24, 26 separately.

[0021] The harmonic suppression device 1 reduces harmonic components (hereinafter referred to as "harmonic currents") of currents (hereinafter referred to as "load currents") Ir, Is, It flowing through system lines Lr, Ls, Lt, which are generated by the operation of each inverter 24, 26. In the first embodiment, the harmonic suppression device 1 is embodied as an active filter, and offsets the harmonic currents with compensation currents Icr, Ics, Ict of opposite phases by superimposing these compensation currents on the harmonic currents of each phase.

[0022] The harmonic suppression device 1 includes a converter 11 that generates compensation currents Icr, Ics, and Ict, a passive filter 12, and, as a control system, a controller 13 and various detectors 14. In the first embodiment, current detectors 141 and 142 and a voltage detector 143 are provided as the detector 14.

[0023] The converter 11 is, for example, a modular multilevel converter (MMC), and is connected in parallel with the air conditioner 2 to the system lines Lr, Ls, and Lt.

[0024] The passive filter 12 is a type of filter, and is disposed in the power line between the system lines Lr, Ls, and Lt and the converter 11.

[0025] Specifically, the passive filter 12 is configured by arranging a total of three sets of filter reactors 121r, 121s, 121t and converter reactors 122r, 122s, 122t in parallel with each other, with one filter reactor 121 (121r, 121s, 121t) and one converter reactor 122 (122r, 122s, 122t) connected in series to each other, and connecting the filter reactors 121r, 121s, 121t to the system lines Lr, Ls, Lt of the corresponding phase at one end of each set, and further connecting the converter reactors 122r, 122s, 122t to the output terminals of the converter 11 of the corresponding phase at the other end.

[0026] The passive filter 12 further includes three filter capacitors 123r, 123s, and 123t that are connected to the power lines of the corresponding phases among the power lines that connect the filter reactors 121r, 121s, and 121t and the converter reactors 122r, 122s, and 122t, and that are connected to each other by star connection. Here, the filter reactors 121r, 121s, and 121t and the filter capacitors 123r, 123s, and 123t form a noise removal filter.

[0027] As described later, the filter reactors 121r, 121s, 121t, the converter reactors 122r, 122s, 122t, and the filter capacitors 123r, 123s, 123t are mounted on a common printed wiring board 124 to form the filter substrate 12. The filter reactors 121r, 121s, 121t, the converter reactors 122r, 122s, 122t, and the filter capacitors 123r, 123s, 123t form an LCL circuit for each phase. For example, the filter reactor 121r, the converter reactor 122r, and the filter capacitor 123r form an LCL circuit for the r-phase.

[0028] The noise removal filter removes high-frequency noise generated by the switching operation of the converter 11 and prevents the high-frequency noise from spreading to other electrical devices via the system lines Lr, Ls, and Lt. The converter reactors 122r, 122s, and 122t suppress current ripples generated by the switching operation of the converter 11.

[0029] The controller 13 controls the operation of the converter 11 based on the current and voltage detected by the first and second current detectors 141 , 142 and the voltage detector 143 .

[0030] The first current detector 141 detects the load currents Ir, Is, It flowing in the system lines Lr, Ls, Lt between the connection position of the passive filter 12 and the air conditioner 2. Specifically, it detects the load currents Ir, Is flowing in the two system lines Lr, Ls from the AC power source E toward the rectifier circuit 21 of the air conditioner 2.

[0031] The second current detector 142 detects the compensation currents Icr, Ics, and Ict flowing through the power lines connecting the passive filter 12 and the converter 11. Specifically, the second current detector 142 detects the compensation currents Icr and Ics flowing through the two power lines from the converter 11 to the passive filter 12.

[0032] The voltage detector 143 is connected to the system lines Lr, Ls, and Lt, and detects the power supply voltages Vr, Vs, and Vt of the respective phases of the AC power supply S.

[0033] Here, the controller 13 controls the output voltage of the converter 11 based on the detected currents Ir, Is, Icr, Ics and voltages Vr, Vs, Vt so as to supply the system lines Lr, Ls, Lt with compensation currents Icr, Ics, Ict of opposite phases capable of canceling out the harmonic currents. Of the load currents Ir, Is, It flowing through the system lines Lr, Ls, Lt, the load current It of the t phase, which is not subject to direct detection, can be calculated from the detection result (currents Ir, Is) of the first current detector 141. Similarly, of the compensation currents Ir, Is, It of each phase, the compensation current It of the t phase, which is not subject to direct detection, can be calculated from the detection result (currents Icr, Ics) of the second current detector 141.

[0034] In the first embodiment, the converter 11 constitutes a “voltage converter,” and the passive filter 12 constitutes a “noise filter.” As described later, the passive filter 12 is embodied as a filter substrate, and the controller 13 is embodied as, for example, a control substrate on which a microcomputer and its peripheral circuits are mounted.

[0035] 2 and 3 show the internal configuration of the case 101 of the harmonic suppression device 1 that houses each component, and for convenience of explanation, the converter 11 is omitted in FIG. 2, which is a front view. FIG. 2 shows the case 101 with the front part 101f removed, and the position where the control board 13 is disposed is shown by a two-dot chain line. The converter 11 can be disposed in an appropriate manner by utilizing the remaining space of the space S inside the case 101, excluding the space occupied by the filter board 12 and the control board 13. In the example shown in FIG. 2 etc., for example, the space between the filter board 12 and the front part 101f of the case 101 inside the case 101 can be used to dispose the converter 11 equipped with a plurality of switching elements and a capacitor. Patent application No. 2023-015179, previously submitted by the applicant of the present application, discloses an example in which multiple cluster boards mounted with modular multilevel converters, a type of converter 11, are arranged vertically inside a case, and the structure disclosed here can be applied to the arrangement of converter 11 according to the first embodiment.

[0036] As shown in Fig. 3, the case 101 is formed from a thin metal plate by a suitable method such as bending, and has a front-open box shape having a back surface 101r, a top surface 101t, a bottom surface 101b, and left and right side surfaces 101sr, 101sl (see Fig. 2). A front surface 101f, which serves as a lid for closing the opening, is fixed to the front surface of the case 101 by suitable fasteners 101g such as screws to ribs continuing from the top surface 101t, the bottom surface 101b, and the left and right side surfaces 101sr, 101sl, thereby forming an airtight structure having a vertically long rectangular parallelepiped shape as a whole. The back surface 101r, the top surface 101t, the bottom surface 101b, the left and right side surfaces 101sr, 101sl, and the front surface 101f are all walls of the case 101. Of these walls, the rear portion 101r, the side portions 101sr, 101sl, and the front portion 101f correspond to walls extending in the vertical direction, but in the first embodiment, the rear portion 101r is used as a "wall extending in the vertical direction" that serves as a base for supporting the filter substrate 12. Such a harmonic suppression device 1 is housed, for example, inside the housing of the outdoor unit of the air conditioner 2 together with refrigeration cycle parts such as a compressor, a blower, and an outdoor heat exchanger.

[0037] The case 101 has a shape in which the front part 101f and the rear part 101r, which is the back wall of the case 101, have a larger area than the other parts (i.e., the top part 101t, the bottom part 101b, and the left and right side parts 101sr, 101sl), in other words, a shape in which the depth dimension is smaller than the height and width. The case 101 has a shape in which the depth dimension is smaller than the height and width, in other words, the depth dimension is smaller than the height and width. By removing the fastener 101g and removing the front part 101f, it is possible to perform maintenance and management of various components such as the filter board 12 housed inside the case 101. Although not shown in the figure, the converter 11, the filter board 12, and the control board 13 housed in the case 101 each include heat-generating components, and therefore, for cooling them, through-holes penetrating from the inside to the outside are formed in the rear part 101r, the bottom part 101b, and the side part (for example, the left side part 101sl), etc., and the through-holes allow outside air to enter and exit through the through-holes, thereby promoting ventilation inside the case 101.

[0038] The filter board 12 and the control board 13 are arranged side by side on the left and right sides inside the case 101 with each being upright.

[0039] The filter substrate 12 includes a filter reactor 121, a converter reactor 122, and a printed wiring board 124. The filter reactor 121 and the converter reactor 122 are fixed by soldering to the surface of the printed wiring board 124. For ease of explanation, the filter capacitor 123, which is relatively small in size, is not shown.

[0040] As shown in Fig. 3, the filter substrate 12 is arranged vertically inside the case 101, that is, the printed wiring board 124 is parallel to the rear surface 101r of the case 101, and the soldering surface, which is the rear surface of the printed wiring board 124, faces the rear surface 101r. The filter reactors 121r, 121s, 121t and the converter reactors 122r, 122s, 122t are arranged on the front side of the printed wiring board 124, and are arranged such that the filter reactors 121r, 121s, 121t are arranged on the left side and the converter reactors 122r, 122s, 122t are arranged on the right side in the front view shown in Fig. 2. In the first embodiment, the filter and converter reactors 121r, 121s, 121t, 122r, 122s, 122t have the same basic configuration, and all of them employ the choke coil 201.

[0041] 4, filter reactors 121r, 121s, 121t and converter reactors 122r, 122s, 122t are arranged vertically with the central axis of core 2111 (see FIG. 4) of choke coil 201 horizontal. Six choke coils 201 are supported by a similar support structure on rear part 101r of case 101. Therefore, the following description of the configuration of filter substrate 12 and the description of the support structure of the entire filter substrate 12 including choke coil 201 described later can be applied to both filter reactor 121 and converter reactor 122.

[0042] The filter substrate 12 includes a choke coil 201, a printed wiring board (bare board before components are mounted) 124, and various capacitors (not shown). The choke coil 201 includes a coil body 211 having a circular core 2111 and a coil winding 2112 formed by winding a conductive wire around the core 2111, and a base 212 made of a synthetic resin with high heat resistance and strength, which supports the coil body 211 when it is installed on the printed wiring board 124. The coil body 211 forms a reactor. The coil body 211 and the base 212 are joined to each other by an adhesive. The printed wiring board 124 has an electric wiring pattern formed by a printing technology. Choke coil 201 is arranged such that the back surface of base portion 212 faces the front surface of printed wiring board 124, and the conductor wire drawn from coil winding 2112 via base portion 212 passes through an insertion hole formed in printed wiring board 124 from the front surface side to the rear surface side, and is soldered to the rear surface of printed wiring board 124 and connected to the electrical wiring pattern.

[0043] Furthermore, choke coil 201 includes one or more metal fixing protrusions 213 extending from base portion 212 to its back surface side. When choke coil 201 is mounted on printed wiring board 124, fixing protrusions 213 pass through insertion holes formed in printed wiring board 124 in the same manner as the conductor wire drawn from coil winding 2112, and are joined by soldering on the back surface of printed wiring board 124, thereby fixing choke coil 201 to printed wiring board 124. Choke coil 201 and printed wiring board 124 are firmly fixed and held to each other by soldering at multiple points using these multiple fixing protrusions 213 and the conductor wire drawn from coil winding 2112. Then, after the choke coil 201 and the printed wiring board 124 are fixed by soldering, the filter substrate 12 is supported on the wall of the case 101, specifically, on the rear portion 101r, which is a wall portion extending in the vertical direction, by an inward extension portion 301 extending from the wall portion of the case 101 into the inside of the case 101.

[0044] Here, the support structure of the filter substrate 12 according to the first embodiment (hereinafter, may be simply referred to as the "support structure") will be described in detail with reference to FIGS. 4 and 5. FIG.

[0045] In the first embodiment, the inward extending portion 301 is formed separately from the rear portion 101r, and when supporting the filter substrate 12, the base end portion 301b is joined and fixed to the rear portion 101r of the case 101. The joining of the base end portion 301b can be performed by any appropriate method.

[0046] As shown in FIG. 4, the rear portion 101r of the case 101 extending in the vertical direction of the case 101 is provided with an inward extending portion 301 that protrudes from the rear portion 101r toward the inside of the case 101 and extends in a direction perpendicular to the rear portion 101r, that is, in a horizontal direction. The filter substrate 12 is supported by the inward extending portion 301 relative to the rear portion 101r of the case 101. In the first embodiment, one inward extending portion 301 is provided for each choke coil 201, and the number of the inward extending portions 301 and the number of the choke coils 201 are the same, that is, six. This is not limiting, and the number of the inward extending portions 301 may be less than the number of the choke coils 201. However, in order to stably support the entire filter substrate 12, it is desirable to provide at least two inward extending portions 301.

[0047] When the filter substrate 12 is installed, the printed wiring board 124 has an opening Q penetrating the front and back of the printed wiring board 124 at a position opposite the inward extension portion 301 coupled to the rear surface portion 101r. The opening Q has a circular cross section, and its size, i.e., its inner diameter, is smaller than that of the tip portion 301a of the inward extension portion 301. The inward extension portion 301 has an overall circular shape in a cross section perpendicular to the central axis, has a notch at the tip portion 301a extending along the central axis, and is elastically deformable in the radial direction at least at the tip portion 301a. The inward extension portion 301 passes through the opening Q from the rear surface side to the front surface side of the printed wiring board 124 with the tip portion 301a being reduced and deformed, reaches the pedestal portion 212 of the choke coil 201, and engages with the engagement portion 212a formed on the pedestal portion 212.

[0048] The base portion 212 has a hollow portion H at its center, that is, directly beside the center of the core of the coil body 211 (directly below the coil body 211 when the back surface of the base portion 212 is facing downward), and the hollow portion H opens toward the printed wiring board 124 on the back surface side of the base portion 212 through a through hole V. The hollow portion H has an inner diameter capable of receiving the tip portion 301a of the inward extension portion 301, while the inner diameter of the through hole V is smaller than that of the hollow portion H, and the engagement portion 212a is formed as a step portion due to the difference between these inner diameters. As shown in FIG. 5, the hollow portion H has an inner diameter capable of receiving the tip portion 301a of the inward extension portion 301 when the base portion 212 is viewed from the coil body 211 side of the choke coil 201, and has a circular shape concentric with the opening portion Q of the printed wiring board 124, and the through hole V is concentric with the opening portion Q and has approximately the same diameter. After passing through opening Q and through hole V in that order in the contracted and deformed state, tip end 301a of inwardly extending portion 301 restores its original shape in cavity H and expands radially to engage with engaging portion 212a.

[0049] As a result, the inward extension portion 301 is fixed to the rear portion 101r of the case 101 at the base end 301b, while the tip portion 301a abuts against the engagement portion 212a and the locking surface facing the base end of the tip portion 301a abuts against the locking receiving surface of the engagement portion 212a facing the base end, thereby regulating or restricting the movement of the choke coil 201 including the base portion 212 in a direction away from the printed wiring board 124.

[0050] In the first embodiment, an example in which an anchor member (support fixing member) ANC1 is used as the inwardly extending portion 301 is shown.

[0051] A through hole W that penetrates from the inside to the outside is formed in the rear portion 101r of the case 101, and the inward extending portion 301 can be connected to the rear portion 101r by screwing or driving an appropriate fixing member F, such as a screw or pin, through this through hole W into the base end portion 301b.

[0052] The inwardly extending portion 301 has an intermediate portion 301c connecting the base end portion 301b and the tip end portion 301a. The intermediate portion 301c has a larger diameter than both the opening portion Q and the through hole W. As a result, the intermediate portion 301c is interposed between the rear portion 101r of the case 10 and the printed wiring board 124, and functions as a spacer to maintain the distance between them. The intermediate portion 301c holds the engagement portion 212a and the printed wiring board 124 between itself and the tip end portion 301a.

[0053] With this configuration, the inward extension portion 301 not only supports the choke coil 201, but also supports the filter substrate 12, in which the choke coil 201 and the printed wiring board 124 are coupled to each other, on the rear portion 101r of the case 101 by clamping the engagement portion 212a and the printed wiring board 124 between the tip portion 301a and the middle portion 301c.

[0054] The intermediate portion 301c may have a smaller diameter than the opening Q and the through hole W of the back surface portion 101r of the printed wiring board 124. Fig. 6 shows an anchor member ANC2 in which the intermediate portion 301c is formed to have a smaller diameter than both the opening Q and the through hole W, as a modified example of the inward extending portion 301 according to the first embodiment.

[0055] The anchor member ANC2 has a first outward protrusion P1 that is elastically pressed against the inner surface of the rear surface portion 101r with the filter substrate 12 mounted thereon, and has a second outward protrusion P2 that is elastically pressed against the rear surface of the printed wiring board 124. The first outward protrusion P1 closer to the base end 301b holds the rear surface portion 101r between itself and the fixing member F driven into the base end 301b of the inward extending portion 301, and the second outward protrusion P2 closer to the tip end 301a holds the engagement portion 212a and the printed wiring board 124 between itself and the tip end 301a.

[0056] The inward extension portion 301 may be attached to the wall portion of the case 101 not only by a separate means such as a fixing member F, but also by a form that is elastically deformable, like the tip portion 301a, and engages with the rear portion 101r by shrinking and deforming when passing through the through hole W of the rear portion 101r, and then recovering and expanding after passing through.

[0057] The effects obtained by the first embodiment will be described below.

[0058] First, the wall of case 101 and base portion 212 (specifically, engagement portion 212a) are connected by inward extension portion 301 which extends inward from the wall of case 101, passes through opening Q of printed wiring board 124, and reaches base portion 212 of choke coil 201, and filter substrate 12 is directly supported against the wall of case 101.

[0059] Here, when filter substrate 12 is installed vertically inside case 101, choke coil 201 is supported on the wall of case 101, and the weight of choke coil 201 is applied to the wall of case 101 via inward extension portion 301, so that the load on printed wiring board 124 is significantly reduced or becomes essentially zero.

[0060] Therefore, it is possible to stably support filter substrate 12, which has large and heavy choke coil 201 mounted thereon, in a vertical position, and to reduce vulnerability to vibrations and shocks.

[0061] Secondly, in addition to tip portion 301a, inward extending portion 301 is provided with base end portion 301b and intermediate portion 301c, and base end portion 301b is coupled to the wall of case 101, while tip portion 301a and intermediate portion 301c sandwich engaging portion 212a and printed wiring board 124, thereby making it possible to determine the position of filter substrate 12 including choke coil 201 relative to the wall of case 101 and to support filter substrate 12 relative to the wall of case 101. This makes it possible to reduce separate components required for installing filter substrate 12, such as spacers for determining the position of filter substrate 12 inside case 101, and improve workability.

[0062] Thirdly, inward extension portion 301 is formed by anchor members ANC1, ANC2 that are separate from the wall portion of case 101, and tip portions 301a of anchor members ANC1, ANC2 pass through opening Q of printed wiring board 124 to reach base portion 212 and deploy outside opening Q, in the first embodiment, in hollow portion H, to be able to engage with engagement portion 212a. This makes it possible to attach the entire filter substrate 12 to anchor members ANC1, ANC2 attached to the wall portion of case 101 in one step, via opening Q of printed wiring board 124, thereby further improving workability.

[0063] Fourth, by providing the same number of choke coils 201 and inwardly extending portions 301, it becomes possible to support choke coils 201 more stably.

[0064] The inward extensions constituting the support structure can also be formed integrally with the wall of case 101. Below, as a second embodiment of the present invention, an example in which inward extensions 401 are formed integrally with the wall of sheet metal case 101 will be described with reference to Figs. 7 to 9. The support structure according to the second embodiment differs from that of the first embodiment in the configurations of inward extensions 401 and engagement portion 212b of base portion 212 that engages with inward extensions 401, but other configurations are similar to those of the first embodiment, so only the configurations of the different parts will be described.

[0065] In the second embodiment, the inwardly extending portion 401 has a base end portion 401b that rises from the rear portion 101r and continues toward the inside of the case 101, and has an intermediate portion 401c that connects the base end portion 401b and the tip end portion 401a. The inwardly extending portion 401 is formed in a vertically elongated thin piece by cutting a part of the plate material that forms the rear portion 101r by cutting and bending the plate material by 90° toward the inside of the case 101 in a substantially L-shape. As in the first embodiment, the number of the inwardly extending portions 401 and the number of the choke coils 201 may be the same or different. In the example of FIG. 7, six inwardly extending portions 401 are provided in accordance with the number and positions of the choke coils 201.

[0066] As shown in Fig. 7, the base portion 212 of the choke coil 201 is provided with an engagement portion 212b at one of its left and right side ends. In Fig. 7, the choke coils 201 (filter reactors 121r, 121s, 121t) arranged on the left side of the paper (i.e., the right side of the case 101) are provided with an engagement portion 212b at the left side end (right side end of the base portion 212) in the figure, and the choke coils 201 (converter reactors 122r, 122s, 122t) arranged on the right side of the paper (i.e., the left side of the case 101) are provided with an engagement portion 212b at the right side end (left side end of the base portion 212) in the figure.

[0067] If choke coils 201 with the same characteristics can be used for filter reactor 121 and converter reactor 122, then each choke coil 201 can be rotated 180° and attached to the left and right, promoting the standardization of parts and reducing procurement costs. Depending on conditions such as the board area, engagement portions 212b may be formed on both the left and right sides of base portion 212, which eliminates the need to consider the orientation of choke coil 201 when mounting on printed wiring board 142 and simplifies the process.

[0068] 8 and 9, printed wiring board 124 has six openings Q that are long in the up-down direction (depth direction in FIG. 9) following the cross-sectional shape of thin-plate-like inwardly extending portion 401, and are formed in accordance with the positions of inwardly extending portion 401. When filter substrate 12 is installed on rear surface portion 101r, inwardly extending portion 401 passes through openings Q from the rear surface side to the front surface side of printed wiring board 124, reaches base portion 212 of choke coil 201, and engages at tip portion 401a with engaging portion 212b formed on the side end of base portion 212.

[0069] The engaging portion 212b is a part of the base portion 212 and has a generally vertically long rectangular parallelepiped shape, with a notch C formed by cutting out a part of the side connecting the upper and lower side end corners. Here, the notch C forms a front-rear locking receiving surface Cf1 facing the front of the case 1, and a pair of upper and lower upper and lower locking receiving surfaces Cf2 facing downward and upward of the case 101. FIG. 9 shows the upper upper and lower locking receiving surface Cf2 facing downward of the case 101. The tip portion 401a of the inward extending portion 401 engages with the engaging portion 212b to restrict the movement of the entire filter substrate 12 including the choke coil 201 in a direction away from the rear surface portion 101r, and also restricts the movement of the filter substrate 12 in the up-down direction, i.e., the vertical direction, relative to the rear surface portion 101r.

[0070] To explain in detail the configuration of the portion where the inward extending portion 401 and the engaging portion 212b engage, a first locking claw N1 that protrudes laterally toward the base portion 212 or the engaging portion 212b is formed at the tip portion 401a of the inward extending portion 401 by cutting and raising the inward extending portion 401, and the tip portion 401a engages with the engaging portion 212b at the first locking claw N1. In other words, the tip portion 401a engages with the engaging portion 212b by fitting the first locking claw N1 into the notch C and being disposed therein. The first locking claw N1 has its lower surface (the end surface facing toward the rear portion 101r) which faces and forms front and rear locking surfaces that abut against the front and rear locking receiving surfaces Cf1 of the notch C, and its upper and lower end surfaces (the end surfaces in the depth direction in Figure 9) which face and form upper and lower locking surfaces that abut against the upper and lower locking receiving surfaces Cf2 of the notch C.

[0071] Here, when the filter substrate 12 moves downward due to its own weight, the upper end face of the first locking claw N1 comes into contact with the upper upper and lower locking receiving surfaces Cf2 of the notch C (i.e., the upper and lower locking receiving surfaces Cf2 facing downward), suppressing displacement of the filter substrate 12 and maintaining its position. Furthermore, even if the filter substrate 12 moves upward due to vibration during transportation, etc., the lower end face of the tip portion 401a comes into contact with the lower upper and lower locking receiving surfaces Cf2 of the notch C, preventing further movement of the filter substrate 12.

[0072] In addition to the first locking claw N1, the inwardly extending portion 401 is provided with a second locking claw N2 that protrudes in the same direction as the first locking claw N1 at the middle portion 401c. The second locking claw N2 abuts against the back side of the printed wiring board 124 to restrict the movement of the printed wiring board 124 toward the back portion 101r, that is, in the direction away from the choke coil 201, and cooperates with the first locking claw N1 to clamp the engagement portion 212b and the printed wiring board 124 from the front and rear. The second locking claw N2 is formed by cutting and raising a part of the middle portion 401c in the same manner as the first locking claw N1, and curving the cut portion in the same direction as the first locking claw N1. Here, a remaining portion 401d that remains after the cutting and raising of the locking claws N1 and N2 is formed between the first locking claw N1 and the second locking claw N2 of the inwardly extending portion 401.

[0073] In this way, the inwardly extending portion 401 determines the distance of the choke coil 201 and the entire filter substrate 12 from the rear surface portion 101r of the case 101 by the first and second locking claws N1 and N2, and can determine the position of the filter substrate 12 in the vertically placed state in the front-rear and up-down directions. The first locking claw N1 and the second locking claw N2 may be formed to protrude in opposite directions. Specifically, the first locking claw N1 protrudes to the left or right to engage with the engaging portion 212b, while the second locking claw N2 protrudes in the opposite direction and abuts against the rear surface of the printed wiring board 124 on the side opposite to the engaging portion 212b, and the two cooperate to determine the position of the filter substrate 12 in the front-rear direction.

[0074] 7, the first and second locking claws N1 and N2 are formed in mutually opposite directions, that is, inward directions, between the choke coil 201 arranged on the left side and the choke coil 201 arranged on the right side when the case 101 is viewed from the front, in this embodiment, they are formed in mutually opposite directions (i.e., inward). Specifically, in the inward extension portion 401 provided for the choke coil 201 on the left side in the figure, the first and second locking claws N1, N2 are provided so as to protrude to the right in the figure (left side of the case 101) toward the base portion 212 located on the right side, and in the inward extension portion 401 provided for the choke coil 201 on the right side in the figure, the first and second locking claws N1, N2 are provided so as to protrude to the left in the figure (right side of the case 101) toward the base portion 212 located on the left side.

[0075] As shown in FIG. 9, the engagement portion 212b and the printed wiring board 124 are clamped by the first and second locking claws N1, N2, thereby determining the position of the filter substrate 12 in a direction perpendicular to the rear portion 101r, i.e., in the front-to-rear direction, while the remaining portion 401d of the inward extension portion 401 that remains between the first and second locking claws N1, N2 abuts against the engagement portion 212b, thereby restricting the movement of the filter substrate 12 in the left-to-right direction and determining its position in the left-to-right direction.

[0076] Specifically, in FIG. 7, for the choke coil 201 on the left side of the figure, the remaining portion 401d of the left-side inward extension portion 401 abuts against the side surface of the engagement portion 212b (i.e., the right side surface), and for the choke coil 201 on the right side of the figure, the remaining portion 401d of the right-side inward extension portion 401 abuts against the side surface of the engagement portion 212b (i.e., the left side surface).

[0077] In the second embodiment, the inward extension 401 is integrally formed with the rear part 101r made of sheet metal, which is the wall part of the case 101, and the wall part of the case 101 and the tip part 401a of the inward extension 401 are connected by the base part 401b continuing from the rear part 101r and the intermediate part 401c continuing therefrom, and the tip part 401a is locked to the engagement part 212b by the cooperation of the first and second locking claws N1 and N2 so that the distance of the choke coil 201 from the rear part 101r can be determined. This makes it possible to directly support the choke coil 201 against the wall part of the case 101 via the inward extension 401, and to significantly reduce or substantially eliminate the load on the printed wiring board 124.

[0078] Furthermore, by forming inward extension portion 401 integrally with the wall portion of case 101, there is no need to prepare a separate part to support choke coil 201. In addition, by giving inward extension portion 401 the function of a spacer that maintains the distance between rear portion 101r and filter substrate 12, it is possible to reduce the number of parts.

[0079] Furthermore, by forming inwardly extending portion 401 by cutting and raising it from rear portion 101r, the effort required to form inwardly extending portion 401 is reduced, the number of parts is reduced, and work efficiency when installing filter substrate 12 is improved.

[0080] In the above description, the inward extending portions 301, 401 are provided on the back surface portion 101r, which is a wall portion of the case 101. However, the wall portion on which the inward extending portions 301, 401 are provided may be any wall portion that extends in the vertical direction of the case 101. For example, the wall portion of the case 101 may be the right or left side surface portion 101sr, 101sl of the case 101, or may be an inner wall portion 101w separately provided inside the case 101.

[0081] Fig. 10 shows an example in which an inner wall portion 101w made of sheet metal is provided to divide the space S inside the case 101 into front and rear portions, and the filter substrate 12 is installed on this inner wall portion 101w. The choke coil 201 can be supported on the inner wall portion 101w by any of the support structures described above. Specifically, the inward extension portions 301, 401 can be configured separately from the inner wall portion 101w by the inward extension portion 301 (anchor members ANC1, ANC2) shown in Fig. 4 and Fig. 6, or can be formed integrally with the inner wall portion 101w by the inward extension portion 401 shown in Fig. 9, etc.

[0082] Furthermore, in the above description, a male locking surface is formed on tip portions 301a, 401a of inwardly extending portions 301, 401, while a female locking surface for receiving tip portions 301a, 401a is formed on engaging portion 212b of base portion 212. The relationship between the tip portions and the engaging portion is not limited to this, and it is also possible to form a female locking surface on the tip portion and a male locking surface on the engaging portion.

[0083] 11 and 12, the engagement portion 212b is provided on the base portion 212 as a protrusion 212b protruding laterally from a side end portion of the base portion 212. Specifically, in an arrangement similar to that shown in Fig. 7, the choke coil 201 arranged on the left side is integrally formed with a protrusion 212b protruding leftward in the figure from the left side end portion of the base portion 212, and the choke coil 201 arranged on the right side is integrally formed with a protrusion 212b protruding rightward in the figure from the right side end portion of the base portion 212.

[0084] On the other hand, inwardly extending portion 401 formed by cutting and raising in the same manner as in the example shown in Fig. 9 has receiving portion R formed to penetrate tip portion 401a in the thickness direction. In the examples shown in Fig. 11 and Fig. 12, receiving portion R is a hole penetrating tip portion 401a in the thickness direction.

[0085] Here, by inserting engagement portion 212b into receiving portion R of tip portion 401a and positioning it therein, movement of the entire filter substrate 12 including choke coil 201 is restricted in both the front-to-rear direction of case 101 perpendicular to rear portion 101r and the up-to-down direction of case 101 parallel to rear portion 101r.

[0086] That is, in this modification, the receiving portion R of the tip portion 401a is formed with a front / rear locking surface Rf1 facing the rear of the case 101 and a pair of upper and lower locking surfaces Rf2 facing downward and upward of the case 101. Then, of the locking portion 212b, an end face facing the front of the case 101 forms a front / rear locking receiving surface that faces and abuts against the front / rear locking surface Rf1 of the receiving portion R, and its upper and lower end faces (end faces in the depth direction in FIG. 12) form upper and lower locking receiving surfaces that face and abut against the upper and lower locking surfaces Rf2 of the receiving portion R.

[0087] Furthermore, similar to the examples shown in Figures 8 and 9, the inward extension portion 401 abuts against the side end portion of the base portion 212 at the intermediate portion 401c, thereby restricting the movement of the filter substrate 12 in the left-right direction and determining its position in the left-right direction.

[0088] The support structure according to this modification has a relatively simple configuration in which a protrusion is formed as the locking portion 212b on the base portion 212 and a receiving portion R (hole) is formed on the tip portion 401a of the inward extending portion 401, so that the processing effort and cost can be reduced. Furthermore, the opening Q of the printed wiring board 124 through which the inward extending portion 401 passes when the filter substrate 12 is installed can be a relatively small opening having an opening area slightly larger than the cross-sectional area of ​​the thin inward extending portion 401 extending straight from the rear portion 101r of the case 101, so that the influence on the printed wiring board 124 can be kept small, and for example, it is possible to avoid a situation in which the mounting area of ​​the circuit pattern is excessively reduced. Furthermore, the choke coil 201 (base portion 212) and the printed wiring board 124 are fixed by soldering the conductor drawn from the coil winding 2112 and the fixing protrusion 213, so that no separate member is required to maintain and regulate the distance and positional relationship between them. In addition, components other than the choke coil mounted on printed wiring board 124, such as the three filter capacitors 123r, 123s, and 123t, are relatively small and lightweight, so these components do not impose excessive load on the soldered portion between the conductor drawn from coil winding 2112 and fixing protrusion 213.

[0089] The receiving portion R can be formed not only as a through portion as shown in FIG. 12, but also as a concave portion converging near the side surface of the tip portion 401a by recessing or drilling the inward extending portion 401 in the thickness direction at the tip portion 401a, in other words, by forming a recess in the thickness direction. [Explanation of symbols]

[0090] 1...Harmonic suppression device, 11...Converter, 12...Passive filter (filter board), 121 (121r, 121s, 121t)...Filter reactor, 122 (122r, 122s, 122t)...Converter reactor, 124...Printed wiring board, 101...Case, 101...Case, 101r...Rear part (wall part), 101w...Inner wall part (Wall portion), 212...base portion, 212a, 212b...engagement portion, 301, 401...inward extension portion, 301a, 401a...tip portion, 301b, 401b...base end portion, 301c, 401c...middle portion, H...hollow portion, ANC1, ANC2...anchor member, P1, P2...outward protrusion portion, N1...first locking claw, N2...second locking claw, C...notch, R...receiving portion.

Claims

1. A wiring board having an electrical wiring pattern; A support structure for a filter substrate, which supports, within a case, a filter substrate including a choke coil having a coil body, a coil winding wound around the coil body, and a base portion supporting the coil body, the base portion facing the wiring board, and the coil winding being connected to the electrical wiring pattern and fixed to the wiring board, an inward extending portion is provided extending inwardly of the case from a wall portion extending in a vertical direction of the case; the wiring board has an opening through which the inwardly extending portion can be inserted, The inward extension portion passes through the opening and reaches the base portion, The base portion has an engagement portion that engages with a tip end portion of the inward extending portion, The filter substrate is supported on the wall portion by the inward extending portion.

2. The support structure for a filter substrate according to claim 1 , wherein the engagement portion is engaged with a tip end of the inwardly extending portion in a manner capable of restricting movement of the filter substrate in a direction perpendicular to the wall portion.

3. The inward extending portion has a locking surface at the tip portion that faces in a direction perpendicular to the wall portion, The support structure for a filter substrate according to claim 2 , wherein the engaging portion has an engagement receiving surface that faces and abuts against the engaging surface when engaged with the tip end of the inward extending portion.

4. The support structure for a filter substrate according to claim 2 , wherein the engagement portion further engages with the inward extending portion so as to restrict movement of the filter substrate in a direction parallel to the wall portion.

5. The inward extension portion is a base end portion coupled to a wall portion of the case, a tip end portion, and an intermediate portion connecting the base end portion and the tip end portion and being interposed between the wall portion and the wiring board to maintain a distance between the wall portion and the wiring board, The support structure for a filter substrate according to claim 1 , wherein the engaging portion and the wiring board are sandwiched between the tip portion and the intermediate portion.

6. the inwardly extending portion is constituted by an anchor member provided separately from the wall portion of the case, The support structure for a filter substrate as described in claim 5, wherein the anchor member has a base end connected to the wall portion and a tip end having radially deformable elasticity to pass through the opening and deploy outside the opening to engage with the engagement portion.

7. 6. The support structure for a filter substrate according to claim 5, wherein the base end of the inwardly extending portion continues from the wall portion and is formed integrally with the wall portion of the case.

8. 8. The support structure for a filter substrate according to claim 7, wherein the wall portion is made of a sheet metal member, and the inward extending portion is formed integrally with the wall portion by cutting and raising the sheet metal member.

9. 2. The support structure for a filter substrate according to claim 1, wherein the number of said choke coils and said inward extending portions is the same.

10. A harmonic suppression device that is connected to a system line that connects an AC system and an electrical device and reduces harmonic components of a current flowing through the system line, A voltage converter connected to the system line; a controller that detects the harmonic components and controls an output voltage of the voltage converter so as to supply a compensation current having an opposite phase to the harmonic components to the system line; a noise filter connected between the system line and the voltage converter, the noise filter reducing noise components due to a switching operation of the voltage converter; a case that houses the voltage converter, the controller, and the noise filter, 10. A harmonic suppression device, wherein the noise filter includes the choke coil and the wiring board, and is supported on the case by the support structure according to claim 1.

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