JP7230790B2 - electrical equipment - Google Patents

Description

The technology disclosed in this specification relates to electrical equipment. More particularly, it relates to electrical equipment with ferrite material for suppressing noise passing through conductors.

Electrical equipment may have components made of ferrite material. A typical component made of ferrite material is the core of a transformer or reactor (for example, Patent Document 1).

JP 2006-191765 A

In addition to being used in transformers and reactors, ferrite materials are also used to eliminate noise. When a conductor that is a noise source is surrounded by a ferrite material, the conductor and the ferrite material constitute an inductor and function as a low-pass filter. That is, noise, which is a high-frequency component passing through the conductor, is removed.

Ferrite material is more brittle than metal and the like, and is unsuitable for fixing with screws. Adhesives may not provide sufficient fixation. The present specification provides a structure that can firmly and reliably fix a ferrite material surrounding a conductor with a simple structure.

Many electrical devices have substrates. The electrical equipment disclosed in this specification uses a substrate or a plate member provided under the substrate to fix the ferrite material. The electrical device disclosed in this specification includes a substrate attached to a housing, a conductor arranged under the substrate through which current flows, and a conductor installed in the housing under the substrate and surrounding the conductor. It is equipped with a ferrite material. A spring is attached to the back surface of the substrate to press the ferrite material against the housing, and a hole (first hole) is provided in the substrate. The first hole is provided at a position where the ferrite material can be viewed through the substrate through the first hole.

In the electrical equipment disclosed in this specification, a spring is attached to the board, and the spring presses the ferrite material against the housing to fix it. Therefore, the ferrite material is firmly fixed. Moreover, the substrate on the ferrite material is attached after the ferrite material is installed in the housing. A spring is attached to the substrate, and the spring is compressed by a fastening force for attaching the substrate to the housing to bias the ferrite material. The ferrite material can be firmly fixed with a simple structure.

Moreover, when the spring is compressed by the fastening force of the substrate, the fragile ferrite material may crack. In order to detect cracking of the ferrite material when the substrate is pressed, a hole (first hole) is provided in the substrate so that the ferrite material can be visually recognized through the substrate. Since it is possible to check whether or not the ferrite material is cracked through the first hole, the risk of shipping an electrical device that has been cracked and fixed in an unstable state can be reduced. It is possible to provide an electrical device in which the ferrite material is reliably fixed.

The spring passes over the first hole and may be provided with a second hole or notch so that the ferrite material under the spring is visible.

Note that the ferrite material may be installed directly on the housing, or may be installed on the housing via another device, a vibration-proof sheet, or the like. Alternatively, the ferrite material may be adhered to the housing and pressed by a spring. Further, the ferrite material surrounding the conductor may be split into multiple parts.

Details and further improvements of the technique disclosed in this specification are described in the following "Mode for Carrying Out the Invention".

FIG. 1A is a plan view of the electrical equipment of the first embodiment. FIG. 1(B) is a cross-sectional view taken along line BB of FIG. 1(A). FIG. 2A is a plan view of the electrical equipment of the second embodiment. FIG. 2B is a cross-sectional view taken along line BB of FIG. 2A.

(First Embodiment) An electric device of a first embodiment will be described with reference to the drawings. The electrical equipment of the first embodiment is a power converter 2 that converts battery power into drive power for a motor for running in an electric vehicle. FIG. 1A shows a plan view of the power converter 2. As shown in FIG. FIG. 1B shows a cross-sectional view of the power converter 2 along line BB in FIG. 1A. In FIG. 1, only part of the housing 3 of the power converter 2 is shown. In addition, FIG. 1 shows only some of the components that make up the power converter 2 .

Although the details will be described later, the portion shown in gray in FIG.

A housing 3 of the power converter 2 is provided with a partition plate 4 along which two busbars 5 are arranged. The two busbars 5 are conductors for sending battery power to power conversion elements (for example, switching elements).

For example, if the busbar 5 is connected to a switching element, high-frequency noise caused by the switching operation of the switching element flows through the busbar 5 . Therefore, the bus bar 5 is surrounded by the ferrite material 30 . The bus bar 5 and the ferrite material 30 surrounding it form an inductor and function as a low-pass filter. That is, the ferrite material 30 removes high-frequency noise flowing through the bus bar 5 .

A ring-shaped ferrite material 30 surrounding the bus bar 5 is divided into a U-shaped block 32 installed on the partition plate 4 and a ferrite plate 31 connecting both ends of the U-shaped block 32 . The U-shaped block 32 is installed on the partition plate 4 so that the busbar 5 passes through the inside of the U-shape. The U-shaped block 32 is adhered to the partition plate 4 .

The ferrite plate 31 is installed on both U-shaped ends of the U-shaped block 32 so as to surround the bus bar 5 together with the U-shaped block 32 . The ferrite plate 31 is adhered to both U-shaped ends of the U-shaped block 32 .

A substrate 10 is arranged above the ferrite material 30 and the bus bar 5 . A control circuit (not shown) is mounted on the substrate 10 . The control circuit is a driving circuit that drives the switching elements described above. The bus bar 5 extends parallel to the substrate 10 , and the rectangular ring-shaped ferrite material 30 surrounding the bus bar 5 has one outer surface in contact with the partition plate 4 and the opposite outer surface of the ferrite material 30 to the substrate 10 . facing the back of the

Ferrite material is brittle and not suitable for fixing with screws. On the other hand, the ferrite material may not have sufficient fixing strength by adhesion alone. In particular, since the power converter 2 is mounted on an automobile, it is subject to vibrations. In power converter 2, ferrite material 30 is pressed from above by leaf spring 20 so that ferrite material 30 does not shift or come off even when subjected to vibration. The substrate 10 is arranged above the ferrite material 30 , and the plate spring 20 is fixed to the back surface (lower surface) of the substrate 10 with screws 21 . The leaf spring 20 is curved so as to form a convex shape toward the partition plate 4, and the top of the convex shape is in contact with the ferrite material 30 (ferrite plate 31). Since the leaf spring 20 has a hole 22 at the top of its head, the peripheral edge of the hole 22 contacts the ferrite material 30 (ferrite plate 31).

The ferrite material 30 is firmly fixed to the housing 3 by being pressed against the partition plate 4 of the housing 3 by the plate spring 20 . The board 10 is fixed to the housing 3 with a plurality of screws 11 . The tightening direction of the screw 11 is the direction from the substrate 10 toward the ferrite material 30 . Therefore, when the substrate 10 is fixed to the housing 3 with the screw 11 , the tightening force of the screw 11 compresses the leaf spring 20 and biases the ferrite material 30 . That is, in assembling the power converter 2, fixing of the substrate 10 and biasing of the ferrite material 30 can be performed at the same time.

A hole 12 is provided in the substrate 10 . The hole 12 is a viewing hole provided for checking whether the ferrite material 30 is cracked when the plate spring 20 is pressed against the ferrite material 30 and fixed. Since the ferrite material 30 is fragile, there is a risk that it will crack if biased strong force is applied. When the leaf spring 20 is pressed, biased force may be applied to the ferrite material 30 through the substrate 10 and the leaf spring 20, and the ferrite material 30 may crack at that time. When the substrate 10 is attached, it is possible to visually check whether the ferrite material 30 is cracked through the substrate 10 through the hole 12 or by an image inspection device. A thick arrow line C in FIG. 1B schematically represents the line of sight when checking the ferrite material 30 . This confirmation avoids shipping the power converter 2 with the ferrite material 30 cracked. It is possible to provide the power converter 2 in which the ferrite material 30 is securely fixed.

A part of the plate spring 20 overlaps the hole 12 of the substrate 10 when viewed from the normal direction of the substrate 10 (the Z direction of the coordinate system in the drawing). A hole 22 is provided in a portion of the leaf spring 20 overlapping the hole 12 in order to widen the range where the ferrite material 30 can be seen through the hole 12 . In FIG. 1A, the grayed portion is the portion of the ferrite plate 31 that can be visually recognized through the substrate 10 through the hole 12 of the substrate 10 and the hole 22 of the plate spring 20 . In FIG. 1A, the dashed line indicated by reference numeral 31a is the contour of the portion of the ferrite material 30 hidden behind the substrate 10. In FIG. A dashed line indicated by reference numeral 20a is an outline of a portion of the plate spring 20 hidden behind the substrate 10. As shown in FIG.

As described above, the power converter 2 includes the ferrite material 30 surrounding the conductors (busbars 5). It is sandwiched and fixed with the partition plate 4. - 特許庁The ferrite material 30, which is brittle compared to metal, can be firmly fixed by the leaf spring 20. - 特許庁

A hole 12 is provided in the substrate 10 so that it can be checked through the substrate 10 whether the ferrite material 30 fixed by the leaf spring 20 is cracked. A hole 22 is provided in a range overlapping with the hole 12 of the leaf spring 20 in order to widen the visible range. Cracked ferrite material can be detected by viewing through the holes 12, 22 (or by an image processor). If the ferrite material is cracked, shipment of the power converter 2 can be stopped. It is possible to provide the power converter 2 in which the ferrite material 30 is securely fixed. Instead of providing the leaf spring 20 with the hole 22, the leaf spring 20 may be provided with a notch.

(Second Embodiment) A power converter 2a of a second embodiment will be described with reference to FIG. 2(A) is a plan view of the power converter 2a, and FIG. 2(B) is a cross-sectional view taken along line BB of FIG. 2(A). FIG. 2 also shows only part of the housing 3 and only part of the components of the power converter 2a.

The power converter 2a differs from the power converter 2 of the first embodiment in that a coil spring 120 is attached to the rear surface (lower surface) of the substrate 110 and that the substrate 110 is provided with a circular hole 112. (The holes 12 in the substrate 10 of the first embodiment are rectangular). The coil spring 120 is compressed by the fastening force when the substrate 110 is fixed to the housing 3 with the screws 11 , and biases the ferrite material 30 toward the partition plate 4 .

The hole 112 in the substrate 110 is circular and the coil spring 120 is cylindrical with a larger diameter than the hole 112 . Coil spring 120 contacts the back surface of substrate 110 around hole 112 . In FIG. 2A as well, the gray range indicates the range where the ferrite material 30 can be visually recognized through the substrate 110 . A dashed line indicated by reference numeral 31a indicates the outline of a portion of the ferrite material 30 which is hidden behind the substrate 110 and cannot be seen.

Since the diameter of the coil spring 120 is larger than the diameter of the hole 112 , the entire range of the hole 112 becomes the visible range of the ferrite material 30 . By providing the cylindrical coil spring 120 and the circular hole 112 , in the power converter 2 a, the entire range of the hole 112 becomes the range of the ferrite material 30 visible through the substrate 110 .

Points to note regarding the technology described in the embodiment will be described. Since the ferrite material may crack when the spring (substrate) is pressed against the ferrite material, the ferrite material may not be visible through the hole in the substrate after the spring (substrate) is attached. That is, after mounting the spring (substrate), another component may be placed over the hole in the substrate.

Bus bar 5 is an example of a conductor. The hole 12 provided in the substrate 10 (the hole 112 provided in the substrate 110) is an example of the first hole. The hole 22 provided in the leaf spring 20 is an example of the second hole. The holes provided in the substrate may be rectangular, circular or other shapes. The spring that is attached to the back surface of the substrate and biases the ferrite material may be a leaf spring or a coil spring. A plurality of springs are attached to the back surface of the substrate, and the plurality of springs may press the ferrite material against the housing.

In the power converter 2 ( 2 a ) of the embodiment, the ferrite material 30 is placed directly on the partition plate 4 that is part of the housing 3 . The ferrite material may be mounted on the housing via another component attached to the housing 3 . For example, the ferrite material may be placed on the housing 3 with anti-vibration sheets interposed therebetween. A plurality of conductors may pass under the substrate, each conductor surrounded by a separate ferrite material, each ferrite material being biased by a separate spring attached to the back surface of the substrate.

The power converters 2 and 2a are examples of electrical equipment. The technology disclosed in this specification may be applied to electrical equipment other than power converters. Another plate member may be provided below the substrate 10 (110), and the ferrite material may be arranged below the plate member. In that case, the plate member is also provided with a hole, and the ferrite material should be visible through the first hole of the substrate and the hole of the plate member.

Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or in the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims as of the filing. In addition, the techniques exemplified in this specification or drawings can simultaneously achieve a plurality of purposes, and achieving one of them has technical utility in itself.

2, 2a: power converter 3: housing 4: partition plate 5: bus bar 10, 110: board 11, 21: screw 12, 22, 112: hole 20: leaf spring 30: ferrite material 31: ferrite plate 32: U-shaped block 120: Coil spring

Claims (2)

a substrate attached to the housing;
a conductor, located under the substrate, through which current flows;
a ferrite material located in the housing under the substrate and surrounding the conductor;
and
A spring that presses the ferrite material against the housing is attached to the back surface of the substrate, and the substrate is provided with a first hole. An electrical device in which the ferrite material is provided at a visible position. 2. The electrical spring of claim 1, wherein said spring passes through said first hole and is provided with a second hole or notch so that said ferrite material under said spring is visible. device.

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