JP7634426B2

JP7634426B2 - Power meter

Info

Publication number: JP7634426B2
Application number: JP2021086774A
Authority: JP
Inventors: 慎一良知
Original assignee: Toshiba Toko Meter Systems Co Ltd
Current assignee: Toshiba Toko Meter Systems Co Ltd
Priority date: 2021-05-24
Filing date: 2021-05-24
Publication date: 2025-02-21
Anticipated expiration: 2041-05-24
Also published as: JP2022179947A

Description

本発明は、電力量計に関する。 The present invention relates to a watt-hour meter.

従来、電力量計は、計量装置と、計量装置に取り付けられ且つ計量装置で計量された電力量を外部に送信する通信装置と、端子ブロック、カバーを有している。図７（ａ）～図７（ｄ）は、従来の電力量計において、計量装置、端子ブロック、通信装置、カバーを組立てる手順を示した工程図である。図７（ａ）は、計量装置を端子ブロックに取付ける方向を示し、図７（ｂ）は、計量装置に端子ブロックを取り付けた状態を示し、図７（ｃ）は、計量装置に通信装置を取り付けた状態を示し、図７（ｄ）は、端子ブロックにカバーを取り付けて完成した電力量計を示す。 Conventionally, an electricity meter has a metering device, a communication device that is attached to the metering device and transmits the amount of electricity measured by the metering device to the outside, a terminal block, and a cover. Figures 7(a) to 7(d) are process diagrams showing the procedure for assembling the metering device, terminal block, communication device, and cover in a conventional electricity meter. Figure 7(a) shows the direction in which the metering device is attached to the terminal block, Figure 7(b) shows the state where the terminal block is attached to the metering device, Figure 7(c) shows the state where the communication device is attached to the metering device, and Figure 7(d) shows the completed electricity meter with the cover attached to the terminal block.

図８（ａ）、（ｂ）は、従来の電力量計の分解図を示す。図９（ａ）は、従来の電力量計用通信装置の外観を示し、図９（ｂ）は、通信装置に設けられた計量装置取付部２４ａを示す。計量装置は、図８（ａ）～図８（ｂ）に示すように、電力量を表示する表示部１ａと通信装置接続部１ｂと開閉検出部１ｃと導体接続部１ｄとセンサ接続部１ｅとベース取付部１ｆを有する回路部１、回路部１のセンサ接続部１ｅに接続するセンサ側回路接続部２ａを有し電流を測定するセンサ部２、回路部１の導体接続部１ｄに接続して電源供給する導体側回路接続部３ａと端子ブロックの端子９の端子側導体接続部９ｂと接続する導体側端子接続部３ｂを備えている導体３、通信装置接続部通し穴４ａと通信装置取付部４ｂとブロック取付部４ｃと開閉検出部通し穴４ｄとケース取付部４ｅと導体通し穴４ｆと回路取付部４ｇを備えるベース４、それらを収納し、表示窓５ａとケース側ベース取付部５ｂとケース防水用リブ収納部５ｃとケース防水用リブ５ｄとケース側固定ねじ取付部５ｅを備えているケース５で構成されている。 Figures 8(a) and (b) show exploded views of a conventional watt-hour meter. Figure 9(a) shows the appearance of a conventional communication device for a watt-hour meter, and Figure 9(b) shows a metering device mounting portion 24a provided on the communication device. As shown in Figures 8(a) and 8(b), the measuring device is composed of a circuit section 1 having a display section 1a that displays the amount of power, a communication device connection section 1b, an open/close detection section 1c, a conductor connection section 1d, a sensor connection section 1e, and a base mounting section 1f; a sensor section 2 having a sensor side circuit connection section 2a that connects to the sensor connection section 1e of the circuit section 1 and measures the current; a conductor 3 having a conductor side circuit connection section 3a that connects to the conductor connection section 1d of the circuit section 1 to supply power and a conductor side terminal connection section 3b that connects to the terminal side conductor connection section 9b of the terminal 9 of the terminal block; a base 4 having a communication device connection section through hole 4a, a communication device mounting section 4b, a block mounting section 4c, an open/close detection section through hole 4d, a case mounting section 4e, a conductor through hole 4f, and a circuit mounting section 4g; and a case 5 that houses them and has a display window 5a, a case side base mounting section 5b, a case waterproof rib storage section 5c, a case waterproof rib 5d, and a case side fixing screw mounting section 5e.

通信装置は、図９（ａ）～図９（ｂ）に示すように、計量装置接続部２１ａ、計量装置取付部２４ａを有している。 As shown in Figures 9(a) and 9(b), the communication device has a weighing device connection portion 21a and a weighing device mounting portion 24a.

端子ブロックは、図８（ａ）～図８（ｂ）に示すように、ブロック取付ねじ６、導体接続ねじ７、電線取付ねじ８、電線収納部９ａと端子側導体接続部９ｂを備える端子９、ブロック側ベース取付部１０ａとカバー取付用雌ねじ部１０ｂと電線通し穴１０ｃと端子取付部１０ｄとブロック側固定ねじ取付部１０ｅとブロック防水用リブ収納部１０ｆを備えるブロック１０で構成されている。 As shown in Figures 8(a) and 8(b), the terminal block is composed of a block mounting screw 6, a conductor connection screw 7, a wire mounting screw 8, a terminal 9 with a wire storage section 9a and a terminal side conductor connection section 9b, and a block 10 with a block side base mounting section 10a, a cover mounting female thread section 10b, a wire through hole 10c, a terminal mounting section 10d, a block side fixing screw mounting section 10e, and a block waterproof rib storage section 10f.

カバーは、図８（ａ）～図８（ｂ）に示すように、検出用凸部１１ａとカバー防水用リブ１１ｂを備えるカバー１１とカバー取付ねじ１２で構成されている。 As shown in Figures 8(a) and 8(b), the cover is composed of a cover 11 having a detection convex portion 11a and a cover waterproofing rib 11b, and a cover mounting screw 12.

このように構成された計量装置、通信装置、端子ブロック、カバーを電力量計に組立てる手順を以下に記す。まず、図７（ａ）に示すように、計量装置を端子ブロックの上方に配置して下方に移動させると、図７（ｂ）に示すように、計量装置を端子ブロックに篏合させる。 The procedure for assembling the thus configured metering device, communication device, terminal block, and cover into the electricity meter is as follows. First, as shown in Figure 7(a), the metering device is placed above the terminal block and moved downward, and then, as shown in Figure 7(b), the metering device is mated with the terminal block.

その後、計量装置の導体側端子接続部３ｂを、端子ブロックの導体接続ねじ７で端子９の端子側導体接続部９ｂに固定し、計量装置のブロック取付部４ｃを、ブロック取付ねじ６で端子ブロックのブロック側ベース取付部１０ａに固定することで、計量装置を端子ブロックに取り付けることができる。 Then, the conductor side terminal connection portion 3b of the weighing device is fixed to the terminal side conductor connection portion 9b of the terminal 9 with the conductor connection screw 7 of the terminal block, and the block mounting portion 4c of the weighing device is fixed to the block side base mounting portion 10a of the terminal block with the block mounting screw 6, thereby attaching the weighing device to the terminal block.

このとき、ケース５のケース防水用リブ５ｄは、ブロック１０のブロック防水用リブ収納部１０ｆに収納される。その後、図７（ｃ）に示すように、通信装置の計量装置取付部２４ａを、計量装置のベース４の通信装置取付部４ｂに嵌合させ、通信装置の計量装置接続部２１ａを、計量装置のベース４の通信装置接続部通し穴４ａを通して、回路部１の通信装置接続部１ｂに接続することで、通信装置を計量装置に取付ける。 At this time, the case waterproof rib 5d of the case 5 is stored in the block waterproof rib storage portion 10f of the block 10. Then, as shown in FIG. 7(c), the weighing device mounting portion 24a of the communication device is fitted into the communication device mounting portion 4b of the weighing device base 4, and the weighing device connection portion 21a of the communication device is connected to the communication device connection portion 1b of the circuit portion 1 through the communication device connection portion through hole 4a of the weighing device base 4, thereby attaching the communication device to the weighing device.

その後、図７（ｄ）に示すように、カバー１１のカバー防水用リブをケース５のケース防水用リブ収納部に挿入し、カバー１１に備えてあるカバー取付ねじ１２を、ブロック１０のカバー取付用雌ねじ部１０ｂに取り付けることで、電力量計が組み立てられることになる。 Then, as shown in FIG. 7(d), the cover waterproof rib of the cover 11 is inserted into the case waterproof rib storage portion of the case 5, and the cover mounting screw 12 provided on the cover 11 is attached to the cover mounting female thread portion 10b of the block 10, thereby assembling the watt-hour meter.

設置された端子ブロックを流用して計量装置を交換する時において、端子ブロックのブロック取付ねじ６と導体接続ねじ７を緩めて、取付けられた古い計量装置を取外し、新しい計量装置を端子ブロックに乗せた後、端子ブロック取付ねじ６と導体接続ねじ７を締付けて固定する必要がある。 When replacing a metering device by reusing an installed terminal block, it is necessary to loosen the block mounting screw 6 and conductor connection screw 7 of the terminal block, remove the old metering device, place the new metering device on the terminal block, and then tighten the terminal block mounting screw 6 and conductor connection screw 7 to secure it in place.

参考として、端子台に接続されている電源側給電用導線および負荷側給電用導線を取り外す必要がなく、給電制御装置の着脱作業を容易かつ安全に行うことができる電力量計が挙げられる。 For reference, there is a power meter that does not require the removal of the power supply conductors and load supply conductors connected to the terminal block, and allows the power supply control device to be easily and safely attached and detached.

特許第４９９１３４０号公報Patent No. 4991340

電力量計交換時において、端子ブロック取付ねじと導体接続ねじを緩めて取付けられた古い計量装置を取外し、新しい計量装置を端子ブロックに取り付ける際、計量装置の端子接続部が端子ブロックの異極端子間を短絡させる可能性がある。 When replacing an electricity meter, the terminal block mounting screws and conductor connection screws are loosened to remove the old metering device, and when attaching a new metering device to the terminal block, the terminal connection of the metering device may short-circuit the opposite pole terminals of the terminal block.

本発明は、計量装置取付時の端子ブロックの異極端子間の短絡を防止することができる電力量計を提供する。 The present invention provides an electricity meter that can prevent short circuits between different pole terminals of a terminal block when a metering device is installed.

上記課題を解決するために、本発明の請求項１は、導体側端子接続部を有する板状の導体を備える計量装置と、前記計量装置に取り付けられ且つ前記計量装置で計量された電力量を外部に送信する通信装置と、電線を接続するとともに前記導体の前記導体側端子接続部と接続する端子側導体接続部を備える端子、前記導体の前記導体側端子接続部を前記端子の前記端子側導体接続部に取り付ける導体接続ねじを備える端子ブロックと、前記計量装置、前記通信装置及び前記端子ブロックを覆うカバーとを有し、前記導体の前記導体側端子接続部を挿入する凹部である導体挿入部と前記導体の前記導体側端子接続部の先端端部を覆う先端部と前記導体接続ねじのねじ頭との当接を避ける凹部として導体接続ねじ用凹部と爪部を有するスナップフィット構造の固定部を有する絶縁体の端子先端保護部を設け、前記導体に前記端子先端保護部の前記固定部の前記爪部に篏合して固定するための穴である導体側穴部を設け、前記導体の前記導体側端子接続部を前記端子先端保護部の前記導体挿入部に挿入し、前記端子先端保護部の前記固定部の前記爪部が前記導体の前記導体側穴部に篏合することで前記端子先端保護部が前記導体に固定され、前記計量装置を前記端子ブロックに取り付ける時、前記導体の前記導体側端子接続部を前記端子の前記端子側導体接続部と前記導体接続ねじのねじ頭の間に挿入すると同時に、前記導体接続ねじのねじ頭は前記端子先端保護部の前記導体接続ねじ用凹部に挿入され、前記導体接続ねじを締め付けて前記導体の前記導体側端子接続部を前記端子の前記端子側導体接続部に接続することで前記計量装置を前記端子ブロックに取付けて組立てられる構造で、通電された電力量計の交換時において、前記導体接続ねじを緩めて取付けられた古い計量装置を取外し、新しい計量装置を端子ブロックに取り付ける際、誤って前記導体の前記導体側端子接続部の先端が隣接する異極端子間に接触した場合、前記導体の前記導体側端子接続部より先に絶縁体である前記端子先端保護部の前記先端部が接触することで、異極端子間の短絡を防止することができることを特徴とする。 In order to solve the above problem, claim 1 of the present invention provides a measuring device having a plate-shaped conductor having a conductor side terminal connection portion, a communication device attached to the measuring device and transmitting the amount of electric power measured by the measuring device to the outside, a terminal having a terminal side conductor connection portion that connects an electric wire and connects to the conductor side terminal connection portion of the conductor, a terminal block having a conductor connection screw that attaches the conductor side terminal connection portion of the conductor to the terminal side conductor connection portion of the terminal, and a cover that covers the measuring device, the communication device, and the terminal block, and a terminal tip protection part of an insulator having a snap-fit structure fixing part having a conductor insertion part that is a recess into which the conductor side terminal connection portion of the conductor is inserted, a tip part that covers the tip end of the conductor side terminal connection portion of the conductor, and a recess for a conductor connection screw and a claw part as a recess that avoids contact between the screw head of the conductor connection screw, and a conductor side hole part that is a hole for engaging and fixing to the claw part of the fixing part of the terminal tip protection part is provided in the conductor, and the conductor side terminal connection part of the conductor is inserted into the conductor insertion part of the terminal tip protection part. The claw portion of the fixing portion of the terminal tip protection portion is engaged with the conductor side hole portion of the conductor, whereby the terminal tip protection portion is fixed to the conductor. When the weighing device is attached to the terminal block, the conductor side terminal connection portion of the conductor is inserted between the terminal side conductor connection portion of the terminal and the screw head of the conductor connection screw, and at the same time, the screw head of the conductor connection screw is inserted into the conductor connection screw recess of the terminal tip protection portion, and the conductor connection screw is tightened to connect the conductor side terminal connection portion of the conductor to the terminal side conductor connection portion of the terminal. The metering device can be attached to the terminal block by connecting it to the terminal block. When replacing an energized watt-hour meter, the conductor connection screw is loosened to remove the old metering device and a new metering device is attached to the terminal block. If the tip of the conductor side terminal connection part of the conductor accidentally comes into contact with adjacent terminals of different polarity when the conductor side terminal connection part of the conductor is attached to the terminal block, the tip of the terminal tip protection part, which is an insulator, will come into contact before the conductor side terminal connection part of the conductor, preventing a short circuit between terminals of different polarity.

請求項２の発明は、導体通し穴を有するベースと導体側端子接続部を有する板状の導体を備える計量装置と、前記計量装置に取り付けられ且つ前記計量装置で計量された電力量を外部に送信する通信装置と、電線を接続するとともに前記導体の前記導体側端子接続部と接続する端子側導体接続部を備える端子、前記導体の前記導体側端子接続部を前記端子の前記端子側導体接続部に取り付ける導体接続ねじを備える端子ブロックと、前記計量装置、前記通信装置及び前記端子ブロックを覆うカバーとを有し、前記導体の前記導体側端子接続部を挿入する凹部である導体挿入部と前記導体の前記導体側端子接続部の先端端部を覆う先端部と前記導体接続ねじのねじ頭との当接を避ける凹部として導体接続ねじ用凹部と引っ掛け部を有する端子先端保護部を設け、前記ベースの前記導体通し穴に前記端子先端保護部の前記引っ掛け部に篏合する凹部であるベース側凹部を設け、前記端子先端保護部の前記先端部を前記ベースの前記導体通し穴に挿入し前記端子先端保護部の前記引っ掛け部が前記ベースの前記ベース側凹部に嵌合した後、前記導体の前記導体側端子接続部を前記端子先端保護部の前記導体挿入部に挿入して固定され、前記計量装置を前記端子ブロックに取り付ける時、前記導体の前記導体側端子接続部を前記端子の前記端子側導体接続部と前記導体接続ねじのねじ頭の間に挿入すると同時に、前記導体接続ねじのねじ頭は前記端子先端保護部の前記導体接続ねじ用凹部に挿入され、前記導体接続ねじを締め付けて前記導体の前記導体側端子接続部を前記端子の前記端子側導体接続部に接続することで前記計量装置を前記端子ブロックに取付けて組立てられる構造で、通電された電力量計の交換時において、前記導体接続ねじを緩めて取付けられた古い計量装置を取外し、新しい計量装置を端子ブロックに取り付ける際、誤って前記導体の前記導体側端子接続部の先端が隣接する異極端子間に接触した場合、前記導体の前記導体側端子接続部より先に絶縁体である前記端子先端保護部の前記先端部が接触することで、異極端子間の短絡を防止することができることを特徴とする。 The invention of claim 2 comprises a metering device having a base with a conductor through hole and a plate-shaped conductor having a conductor side terminal connection part, a communication device attached to the metering device and transmitting the amount of electric power measured by the metering device to an outside, a terminal having a terminal side conductor connection part for connecting an electric wire and connecting with the conductor side terminal connection part of the conductor, a terminal block having a conductor connection screw for attaching the conductor side terminal connection part of the conductor to the terminal side conductor connection part of the terminal, and a cover for covering the metering device, the communication device, and the terminal block, and a conductor insertion part which is a recess for inserting the conductor side terminal connection part of the conductor, a terminal tip protection part having a conductor connection screw recess and a hook part as a recess for avoiding contact between a tip part covering a tip end of the conductor side terminal connection part of the conductor and a screw head of the conductor connection screw, a base side recess which is a recess that fits with the hook part of the terminal tip protection part is provided in the conductor through hole of the base, and the tip part of the terminal tip protection part is inserted into the conductor through hole of the base, and the hook part of the terminal tip protection part is inserted into the conductor through hole of the base, and the base side recess is inserted into the base. and after the conductor side terminal connection portion of the conductor is fitted into the base-side recess of the terminal tip protection portion, the conductor side terminal connection portion of the conductor is inserted into the conductor insertion portion of the terminal tip protection portion and fixed; when the metering device is attached to the terminal block, the conductor side terminal connection portion of the conductor is inserted between the terminal side conductor connection portion of the terminal and the screw head of the conductor connection screw, and at the same time, the screw head of the conductor connection screw is inserted into the conductor connection screw recess of the terminal tip protection portion. The metering device can be attached to and assembled on the terminal block by tightening the conductor connection screw to connect the conductor side terminal connection portion of the conductor to the terminal side conductor connection portion of the terminal. When replacing an energized watt-hour meter, if the tip of the conductor side terminal connection portion of the conductor accidentally comes into contact with adjacent terminals of different poles when the conductor connection screw is loosened to remove the old metering device and a new metering device is attached to the terminal block, the tip of the terminal tip protection portion, which is an insulator, comes into contact before the conductor side terminal connection portion of the conductor, thereby preventing a short circuit between the terminals of different poles.

請求項３の発明は、導体通し穴を有するベースと導体側端子接続部を有する板状の導体を備える計量装置と、前記計量装置に取り付けられ且つ前記計量装置で計量された電力量を外部に送信する通信装置と、電線を接続するとともに前記導体の前記導体側端子接続部と接続する端子側導体接続部を備える端子、前記導体の前記導体側端子接続部を前記端子の前記端子側導体接続部に取り付ける導体接続ねじを備える端子ブロックと、前記計量装置、前記通信装置及び前記端子ブロックを覆うカバーとを有し、前記ベースに前記導体を挿入する導体挿入部と前記導体の前記導体側端子接続部の先端端部を覆う先端部と前記導体接続ねじのねじ頭との当接を避ける凹部として導体接続ねじ用凹部を有する絶縁体の端子先端保護部を設け、前記導体の前記導体側端子接続部を前記ベースの前記導体通し穴および前記ベースの前記導体挿入部に挿入して固定され、前記計量装置を前記端子ブロックに取り付ける時、前記導体の前記導体側端子接続部を前記端子の前記端子側導体接続部と前記導体接続ねじのねじ頭の間に挿入すると同時に、前記導体接続ねじのねじ頭は前記ベースの前記導体接続ねじ用凹部に挿入され、前記導体接続ねじを締め付けて前記導体の前記導体側端子接続部を前記端子の前記端子側導体接続部に接続することで前記計量装置を前記端子ブロックに取付けて組立てられる構造で、通電された電力量計の交換時において、前記導体接続ねじを緩めて取付けられた古い計量装置を取外し、新しい計量装置を端子ブロックに取り付ける際、誤って前記導体の前記導体側端子接続部の先端が隣接する異極端子間に接触した場合、前記導体の前記導体側端子接続部より先に絶縁体である前記ベースの前記端子先端保護部の前記先端部が接触することで、異極端子間の短絡を防止することができることを特徴とする。 The invention of claim 3 includes a metering device having a base with a conductor through hole and a plate-shaped conductor having a conductor side terminal connection portion, a communication device attached to the metering device and transmitting the amount of electric power measured by the metering device to an outside, a terminal having a terminal side conductor connection portion for connecting an electric wire and connecting with the conductor side terminal connection portion of the conductor, a terminal block having a conductor connection screw for attaching the conductor side terminal connection portion of the conductor to the terminal side conductor connection portion of the terminal, and a cover for covering the metering device, the communication device, and the terminal block, and a terminal tip protection part of an insulator having a conductor insertion part for inserting the conductor in the base and a conductor connection screw recess as a recess for avoiding abutment between a tip covering a tip end of the conductor side terminal connection portion of the conductor and a screw head of the conductor connection screw, and the conductor side terminal connection portion of the conductor is inserted into the conductor through hole of the base and the conductor insertion part of the base and fixed, When attaching the metering device to the terminal block, the conductor side terminal connection part of the conductor is inserted between the terminal side conductor connection part of the terminal and the screw head of the conductor connection screw, and at the same time, the screw head of the conductor connection screw is inserted into the conductor connection screw recess of the base, and the conductor connection screw is tightened to connect the conductor side terminal connection part of the conductor to the terminal side conductor connection part of the terminal, thereby attaching and assembling the metering device to the terminal block. When replacing an energized watthour meter, if the tip of the conductor side terminal connection part of the conductor accidentally comes into contact with adjacent terminals of different polarities when the conductor side terminal connection part of the conductor is loosened to remove the old metering device and a new metering device is attached to the terminal block, the tip of the terminal tip protection part of the base, which is an insulator, comes into contact before the conductor side terminal connection part of the conductor, preventing a short circuit between terminals of different polarities.

請求項１の発明によれば、導体側端子接続部の先端を絶縁体の端子先端保護部で覆うことにより、計量装置を端子ブロックに取り付ける時、誤って導体側端子接続部の先端が隣接する異極端子間に接触した場合、導体側端子接続部より先に絶縁体である端子先端保護部が接触するので、異極端子間の短絡を防止することができる。 According to the invention of claim 1, by covering the tip of the conductor side terminal connection part with the terminal tip protection part made of an insulator, if the tip of the conductor side terminal connection part accidentally comes into contact with adjacent terminals of different polarity when attaching the weighing device to the terminal block, the terminal tip protection part made of an insulator will come into contact before the conductor side terminal connection part, thereby preventing a short circuit between the terminals of different polarity.

請求項２の発明によれば、請求項１に対して、端子先端保護部がベースに固定されるので、端子先端保護部が外れることを防止することができる。 According to the invention of claim 2, unlike claim 1, the terminal tip protection part is fixed to the base, so that the terminal tip protection part can be prevented from coming off.

請求項３の発明によれば、請求項２に対して、端子先端保護部がベースに一体化しているので、製造コストを削減することができる。 According to the invention of claim 3, the terminal tip protection part is integrated into the base, which reduces manufacturing costs compared to claim 2.

本発明の第１の実施形態に係る電力量計の斜視図と断面図である。1A and 1B are a perspective view and a cross-sectional view of a watt-hour meter according to a first embodiment of the present invention; 本発明の第１の実施形態に係る電力量計の計量装置と端子先端保護部の斜視図である。1 is a perspective view of a metering device and a terminal tip protection part of an electricity meter according to a first embodiment of the present invention. FIG. 本発明の第２の実施形態に係る電力量計の斜視図と断面図である。5A and 5B are a perspective view and a cross-sectional view of a watt-hour meter according to a second embodiment of the present invention. 本発明の第２の実施形態に係る電力量計の計量装置分解図と端子先端保護部の斜視図である。11 is an exploded view of a metering device of an electricity meter according to a second embodiment of the present invention, and a perspective view of a terminal tip protection part. FIG. 本発明の第３の実施形態に係る電力量計の斜視図と断面図である。11A and 11B are a perspective view and a cross-sectional view of a watt-hour meter according to a third embodiment of the present invention. 本発明の第３の実施形態に係る電力量計のベースの斜視図である。FIG. 11 is a perspective view of a base of a watthour meter according to a third embodiment of the present invention. 従来の電力量計の斜視図である。FIG. 1 is a perspective view of a conventional watt-hour meter. 従来の電力量計の分解図である。FIG. 1 is an exploded view of a conventional watt-hour meter. 従来の電力量計用通信装置の斜視図である。FIG. 1 is a perspective view of a conventional communication device for an electricity meter.

以下、本発明の実施の形態に係る電力量計について、図面を参照しながら詳細に説明する。 The following describes in detail the electricity meter according to an embodiment of the present invention with reference to the drawings.

（第１の実施形態）
図１（ａ）～図１（ｄ）は、本発明の第１の実施形態に係る電力量計の斜視図と断面図である。図１（ａ）は、計量装置を端子ブロックに取付ける方向を示し、図１（ｂ）は、計量装置に端子ブロックを取り付けた状態を示す。図１（ｃ）は、図１（ａ）に示す電力量計の断面図を示す。図１（ｄ）は、図１（ｂ）に示す電力量計の断面図を示す。 (First embodiment)
Figures 1(a) to 1(d) are perspective and cross-sectional views of a watt-hour meter according to a first embodiment of the present invention. Figure 1(a) shows the direction in which a metering device is attached to a terminal block, and Figure 1(b) shows the state in which the terminal block is attached to the metering device. Figure 1(c) shows a cross-sectional view of the watt-hour meter shown in Figure 1(a). Figure 1(d) shows a cross-sectional view of the watt-hour meter shown in Figure 1(b).

図２（ａ）～図２（ｃ）は、電力量計の計量装置と端子先端保護部の斜視図である。図２（ａ）は、ケースにベースが取り付けられた状態を示し、図２（ｂ）、図２（ｃ）は、端子先端保護部の斜視図を示す。 Figures 2(a) to 2(c) are perspective views of the metering device and terminal tip protection part of the electricity meter. Figure 2(a) shows the state in which the base is attached to the case, and Figures 2(b) and 2(c) show perspective views of the terminal tip protection part.

電力量計は、計量装置と、計量装置に取り付けられ且つ計量装置で計量された電力量を外部に送信する通信装置（図９に示す上ケース２３と下ケース２４）と、端子ブロックと、カバーと、端子先端保護部１０１とを有している。 The electricity meter has a metering device, a communication device (upper case 23 and lower case 24 shown in FIG. 9) that is attached to the metering device and transmits the amount of electricity measured by the metering device to the outside, a terminal block, a cover, and a terminal tip protection part 101.

計量装置は、ケース５と、ケース５に収納されるベース４と、ベース４に取り付けられる導体３Ａとを備える。導体３Ａは、端子９に接続される先端が二手になった導体側端子接続部３Ａｂと、端子先端保護部１０１の固定部１０１ｅの爪部１０１ｄに篏合する導体側穴部３Ａ１が設けられている。 The weighing device includes a case 5, a base 4 housed in the case 5, and a conductor 3A attached to the base 4. The conductor 3A has a conductor-side terminal connection portion 3Ab with a two-pronged tip connected to the terminal 9, and a conductor-side hole portion 3A1 that fits into the claw portion 101d of the fixing portion 101e of the terminal tip protection portion 101.

端子ブロックは、電線を接続するとともに導体３Ａと接続する端子側導体接続部９ｂを備える端子９、導体側端子接続部３Ａｂを端子側導体接続部９ｂに取り付ける導体接続ねじ７を備えている。カバーは、計量装置、通信装置及び端子ブロックを覆う。 The terminal block includes a terminal 9 having a terminal side conductor connection portion 9b for connecting the electric wire and the conductor 3A, and a conductor connection screw 7 for attaching the conductor side terminal connection portion 3Ab to the terminal side conductor connection portion 9b. The cover covers the weighing device, the communication device, and the terminal block.

端子先端保護部１０１は、絶縁体からなり、図２（ｂ）、図２（ｃ）に示すように、導体側端子接続部３Ａｂを覆う先端部１０１ａと、導体接続ねじ７のねじ頭を避ける導体接続ねじ用凹部１０１ｂと、導体３Ａを挿入する導体挿入部１０１ｃと、爪部１０１ｄを有するスナップフィット構造の固定部１０１ｅを有している。 The terminal tip protection part 101 is made of an insulator, and as shown in Figs. 2(b) and 2(c), has a tip part 101a that covers the conductor side terminal connection part 3Ab, a conductor connection screw recess 101b that avoids the screw head of the conductor connection screw 7, a conductor insertion part 101c into which the conductor 3A is inserted, and a fixing part 101e with a snap-fit structure having a claw part 101d.

次に、このように構成された第１の実施形態の電力量計の動作を説明する。まず、図２（ａ）に示す導体側端子接続部３Ａｂを、図２（ｃ）に示す端子先端保護部１０１の導体挿入部１０１ｃに挿入すると、図１（ｃ）に示すように、端子先端保護部１０１の爪部１０１ｄが導体側穴部３Ａ１に篏合することで端子先端保護部１０１が固定される。 Next, the operation of the electricity meter of the first embodiment configured in this manner will be described. First, when the conductor side terminal connection portion 3Ab shown in FIG. 2(a) is inserted into the conductor insertion portion 101c of the terminal tip protection portion 101 shown in FIG. 2(c), the claw portion 101d of the terminal tip protection portion 101 fits into the conductor side hole portion 3A1 as shown in FIG. 1(c), thereby fixing the terminal tip protection portion 101.

通信装置を計量装置から取外した状態で計量装置を端子ブロックに取り付ける時、図１（ｃ）に示すように、導体接続ねじ７のねじ頭と端子側導体接続部９ｂの間に隙間がある状態にあり、上方から計量装置を端子ブロックに下ろすと、導体側端子接続部３Ａｂの二手の間に導体接続ねじ７のねじ部が挿入されると同時に、図１（ｂ）、図１（ｄ）に示すように、端子先端保護部１０１の導体接続ねじ用凹部１０１ｂは、導体接続ねじ７のねじ頭を避けることとなる。 When the weighing device is attached to the terminal block with the communication device removed from the weighing device, there is a gap between the head of the conductor connection screw 7 and the terminal side conductor connection part 9b, as shown in Figure 1 (c). When the weighing device is lowered onto the terminal block from above, the threaded part of the conductor connection screw 7 is inserted between the two ends of the conductor side terminal connection part 3Ab, and at the same time, the conductor connection screw recess 101b of the terminal tip protection part 101 clears the head of the conductor connection screw 7, as shown in Figures 1 (b) and 1 (d).

次に、導体接続ねじ７を締め付けて導体側端子接続部３Ａｂを端子側導体接続部９ｂに接続することで、計量装置を端子ブロックに取付けることができる。 Then, the conductor side terminal connection part 3Ab can be connected to the terminal side conductor connection part 9b by tightening the conductor connection screw 7, thereby attaching the weighing device to the terminal block.

このように第１の実施形態に係る電力量計によれば、導体側端子接続部３Ａｂの先端を絶縁体からなる端子先端保護部１０１で覆うことにより、計量装置を端子ブロックに取り付ける時、誤って導体側端子接続部３Ａｂの先端が隣接する異極端子間に接触した場合、導体側端子接続部３Ａｂより先に絶縁体である端子先端保護部１０１が接触するので、異極端子間の短絡を防止することができる。 In this way, with the electricity meter according to the first embodiment, the tip of the conductor side terminal connection part 3Ab is covered with the terminal tip protection part 101 made of an insulator. If the tip of the conductor side terminal connection part 3Ab accidentally comes into contact with adjacent terminals of different polarity when the metering device is attached to the terminal block, the terminal tip protection part 101, which is an insulator, will come into contact before the conductor side terminal connection part 3Ab, preventing a short circuit between the terminals of different polarity.

なお、端子先端保護部１０１において、爪部１０１ｄを有するスナップフィット構造の固定部１０１ｅではなく、爪部１０１ｄ（凸部）のみを有することに変更し、導体３Ａにおいて、導体側穴部３Ａ１ではなく、凹部に変更することでも同様の効果が得られる。 The same effect can be obtained by changing the terminal tip protection part 101 to have only the claw part 101d (convex part) instead of the fixing part 101e of the snap-fit structure having the claw part 101d, and changing the conductor 3A to a concave part instead of the conductor side hole part 3A1.

（第２の実施形態）
図３（ａ）～図３（ｄ）は、本発明の第２の実施形態に係る電力量計の斜視図と断面図である。図３（ａ）は、計量装置を端子ブロックに取付ける方向を示し、図３（ｂ）は、計量装置に端子ブロックを取り付けた状態を示す。図３（ｃ）は、図３（ａ）に示す電力量計の断面図を示す。図３（ｄ）は、図３（ｂ）に示す電力量計の断面図を示す。 Second Embodiment
Figures 3(a) to 3(d) are perspective and cross-sectional views of a watt-hour meter according to a second embodiment of the present invention. Figure 3(a) shows the direction in which the metering device is attached to the terminal block, and Figure 3(b) shows the state in which the terminal block is attached to the metering device. Figure 3(c) shows a cross-sectional view of the watt-hour meter shown in Figure 3(a). Figure 3(d) shows a cross-sectional view of the watt-hour meter shown in Figure 3(b).

図４（ａ）～図４（ｃ）は、電力量計の計量装置と端子先端保護部の斜視図である。図４（ａ）は、ベース周囲の組立図を示し、図４（ｂ）、図４（ｃ）は、端子先端保護部の斜視図を示す。 Figures 4(a) to 4(c) are perspective views of the metering device and terminal tip protection part of the electricity meter. Figure 4(a) shows an assembly diagram of the base and its surroundings, and Figures 4(b) and 4(c) show perspective views of the terminal tip protection part.

電力量計は、計量装置と、計量装置に取り付けられ且つ計量装置で計量された電力量を外部に送信する通信装置と、端子ブロックと、カバーとを有している。 The electricity meter has a metering device, a communication device that is attached to the metering device and transmits the amount of electricity measured by the metering device to the outside, a terminal block, and a cover.

計量装置は、ケース５と、ケース５に収納されるベース４Ｂと、ベース４Ｂに取り付けられる端子先端保護部２０１と、端子先端保護部２０１に取り付けられる導体３とを備える。図４（ａ）に示すように、ベース４Ｂは、導体通し穴４Ｂｆと、ベース側凹部４Ｂ１を有し、導体３は、導体側端子接続部３ｂを有している。 The weighing device includes a case 5, a base 4B housed in the case 5, a terminal tip protection part 201 attached to the base 4B, and a conductor 3 attached to the terminal tip protection part 201. As shown in FIG. 4(a), the base 4B has a conductor passing hole 4Bf and a base side recess 4B1, and the conductor 3 has a conductor side terminal connection part 3b.

端子先端保護部２０１は、絶縁体からなり、図４（ｂ）、図４（ｃ）に示すように、導体側端子接続部３ｂを覆う先端部２０１ａと、導体接続ねじ７のねじ頭を避ける導体接続ねじ用凹部２０１ｂと、導体３を挿入する導体挿入部２０１ｃと、ベース側凹部４Ｂ１に篏合する引っ掛け部２０１ｆを有している。 The terminal tip protection part 201 is made of an insulator, and as shown in Figs. 4(b) and 4(c), has a tip part 201a that covers the conductor side terminal connection part 3b, a conductor connection screw recess 201b that avoids the head of the conductor connection screw 7, a conductor insertion part 201c into which the conductor 3 is inserted, and a hook part 201f that engages with the base side recess 4B1.

端子ブロックは、電線を接続するとともに、導体３と接続する端子側導体接続部９ｂを備える端子９、導体側端子接続部３ｂを端子側導体接続部９ｂに取り付ける導体接続ねじ７を備えている。カバーは、計量装置、通信装置及び端子ブロックを覆う。 The terminal block is provided with terminals 9 each having a terminal-side conductor connection portion 9b for connecting to the conductor 3, and a conductor connection screw 7 for attaching the conductor-side terminal connection portion 3b to the terminal-side conductor connection portion 9b. The cover covers the weighing device, the communication device, and the terminal block.

次に、このように構成された第２の実施形態の電力量計の動作を説明する。まず、図４（ａ）に示すように、端子先端保護部２０１の先端部２０１ａをベース４Ｂの導体通し穴４Ｂｆに挿入し、端子先端保護部２０１の引っ掛け部２０１ｆがベース４Ｂのベース側凹部４Ｂ１に篏合し、導体側端子接続部３ｂを端子先端保護部２０１の導体挿入部２０１ｃに挿入して固定し、基板１、ケース５を取付けることで計量装置が組立てられる。 Next, the operation of the second embodiment of the watt-hour meter configured in this manner will be described. First, as shown in FIG. 4(a), the tip 201a of the terminal tip protection part 201 is inserted into the conductor through hole 4Bf of the base 4B, the hook part 201f of the terminal tip protection part 201 is engaged with the base side recess 4B1 of the base 4B, the conductor side terminal connection part 3b is inserted and fixed into the conductor insertion part 201c of the terminal tip protection part 201, and the board 1 and case 5 are attached to assemble the metering device.

通信装置を計量装置から取外した状態で計量装置を端子ブロックに取り付ける時、図３（ｃ）に示すように、導体接続ねじ７のねじ頭と端子側導体接続部９ｂの間に隙間がある状態にあり、上方から計量装置を端子ブロックに下ろすと、導体側端子接続部３ｂの二手の間に導体接続ねじ７のねじ部が挿入されると同時に、図３（ｂ）、図３（ｄ）に示すように、端子先端保護部２０１の導体接続ねじ用凹部２０１ｂは、導体接続ねじ７のねじ頭を避けることとなる。 When the weighing device is attached to the terminal block with the communication device removed from the weighing device, there is a gap between the head of the conductor connection screw 7 and the terminal side conductor connection part 9b, as shown in Figure 3 (c). When the weighing device is lowered onto the terminal block from above, the threaded part of the conductor connection screw 7 is inserted between the two ends of the conductor side terminal connection part 3b, and at the same time, the conductor connection screw recess 201b of the terminal tip protection part 201 clears the head of the conductor connection screw 7, as shown in Figures 3 (b) and 3 (d).

次に、導体接続ねじ７を締め付けて導体側端子接続部３ｂを端子側導体接続部９ｂに接続することで、計量装置を端子ブロックに取付けることができる。 Then, the conductor side terminal connection part 3b can be connected to the terminal side conductor connection part 9b by tightening the conductor connection screw 7, thereby attaching the weighing device to the terminal block.

このように第２の実施形態に係る電力量計によれば、第１の実施形態に係る電力量計に対して、端子先端保護部２０１の引っ掛け部２０１ｆがベース４Ｂのベース側凹部４Ｂ１に篏合する。即ち、端子先端保護部２０１がベース４Ｂに固定されるので、端子先端保護部２０１が外れることを防止することができる。 As described above, in the watthour meter according to the second embodiment, unlike the watthour meter according to the first embodiment, the hook portion 201f of the terminal tip protection portion 201 fits into the base side recess 4B1 of the base 4B. In other words, since the terminal tip protection portion 201 is fixed to the base 4B, it is possible to prevent the terminal tip protection portion 201 from coming off.

（第３の実施形態）
図５（ａ）～図５（ｄ）は、本発明の第３の実施形態に係る電力量計の斜視図と断面図である。図５（ａ）は、計量装置を端子ブロックに取付ける方向を示し、図５（ｂ）は、計量装置に端子ブロックを取り付けた状態を示す。図５（ｃ）は、図５（ａ）に示す電力量計の断面図を示す。図５（ｄ）は、図５（ｂ）に示す電力量計の断面図を示す。図６は、電力量計のベースの斜視図である。 Third Embodiment
Figures 5(a) to 5(d) are perspective and cross-sectional views of a watt-hour meter according to a third embodiment of the present invention. Figure 5(a) shows the direction in which a metering device is attached to a terminal block, and Figure 5(b) shows the state in which the terminal block is attached to the metering device. Figure 5(c) shows a cross-sectional view of the watt-hour meter shown in Figure 5(a). Figure 5(d) shows a cross-sectional view of the watt-hour meter shown in Figure 5(b). Figure 6 is a perspective view of the base of the watt-hour meter.

計量装置は、ケース５と、ケース５に収納されるベース４Ｃと、導体側端子接続部３ｂを有する導体３とを備える。 The weighing device includes a case 5, a base 4C stored in the case 5, and a conductor 3 having a conductor side terminal connection portion 3b.

図６に示すように、ベース４Ｃは、導体通し穴４Ｃｆと、導体側端子接続部３ｂを覆う先端部４Ｃ３、導体接続ねじ７のねじ頭を避ける導体接続ねじ用凹部４Ｃ４、導体３を挿入する導体挿入部４Ｃ５を有する端子先端保護部４Ｃ２を備えている。 As shown in FIG. 6, the base 4C has a conductor through hole 4Cf, a tip portion 4C3 that covers the conductor side terminal connection portion 3b, a conductor connection screw recess 4C4 that avoids the screw head of the conductor connection screw 7, and a terminal tip protection portion 4C2 that has a conductor insertion portion 4C5 into which the conductor 3 is inserted.

次に、このように構成された第３の実施形態の電力量計の動作を説明する。まず、図５（ｃ）に示すように、導体側端子接続部３ｂをベース４Ｃの導体通し穴４Ｃｆおよび導体挿入部４Ｃ５に挿入して固定し、基板１、ケース５を取付けることで計量装置が組立てられる。 Next, the operation of the watt-hour meter of the third embodiment configured in this manner will be described. First, as shown in FIG. 5(c), the conductor side terminal connection portion 3b is inserted and fixed into the conductor through hole 4Cf and the conductor insertion portion 4C5 of the base 4C, and the substrate 1 and case 5 are attached to assemble the metering device.

通信装置を計量装置から取外した状態で計量装置を端子ブロックに取り付ける時、図５（ｃ）に示すように、導体接続ねじ７のねじ頭と端子側導体接続部９ｂの間に隙間がある状態にあり、上方から計量装置を端子ブロックに下ろすと、導体側端子接続部３ｂの二手の間に導体接続ねじ７のねじ部が挿入されると同時に、図５（ｂ）、図５（ｄ）に示すように、端子先端保護部４Ｃ２の導体接続ねじ用凹部４Ｃ４は、導体接続ねじ７のねじ頭を避けることとなる。 When the weighing device is attached to the terminal block with the communication device removed from the weighing device, there is a gap between the head of the conductor connection screw 7 and the terminal side conductor connection part 9b, as shown in Figure 5 (c). When the weighing device is lowered onto the terminal block from above, the threaded part of the conductor connection screw 7 is inserted between the two ends of the conductor side terminal connection part 3b, and at the same time, the conductor connection screw recess 4C4 of the terminal tip protection part 4C2 clears the head of the conductor connection screw 7, as shown in Figures 5 (b) and 5 (d).

このように第３の実施形態に係る電力量計によれば、第２の実施形態に対して、端子先端保護部４Ｃ２がベース４Ｃに一体化しているので、製造コストを削減することができる。 In this way, with the electricity meter according to the third embodiment, the terminal tip protection portion 4C2 is integrated into the base 4C, which is different from the second embodiment, and therefore manufacturing costs can be reduced.

１回路部
１ａ表示部
１ｂ通信装置接続部
１ｃ開閉検出部
１ｄ導体接続部
１ｅセンサ接続部
１ｆベース取付部
２センサ部
２ａセンサ側回路接続部
３，３Ａ導体
３ａ，３Ａａ導体側回路接続部
３ｂ，３Ａｂ導体側端子接続部
３Ａ１導体側穴部
４，４Ｂベース
４ａ，４Ｂａ，４Ｃａ通信装置接続部通し穴
４ｂ，４Ｂｂ，４Ｃｂ通信装置取付部
４ｃ，４Ｂｃ，４Ｃｃブロック取付部
４ｄ，４Ｂｄ，４Ｃｄ開閉検出部通し穴
４ｅ，４Ｂｅ，４Ｃｅケース取付部
４ｆ，４Ｂｆ，４Ｃｆ導体通し穴
４ｇ，４Ｂｇ，４Ｃｇ回路取付部
４Ｂ１ベース側凹部
４Ｃ２端子先端保護部
４Ｃ３先端部
４Ｃ４導体接続ねじ用凹部
４Ｃ５導体挿入部
５ケース
５ａ表示窓
５ｂケース側ベース取付部
５ｃケース防水用リブ収納部
５ｄケース防水用リブ
５ｅケース側固定ねじ取付部
６ブロック取付ねじ
７導体接続ねじ
８電線取付ねじ
９端子
９ａ電線収納部
９ｂ端子側導体接続部
１０ブロック
１０ａブロック側ベース取付部
１０ｂカバー取付用雌ねじ部
１０ｃ電線通し穴
１０ｄ端子取付部
１０ｅブロック側固定ねじ取付部
１０ｆブロック防水用リブ収納部
１１カバー
１１ａ検出用凸部
１１ｂカバー防水用リブ
１２カバー取付ねじ
２１ケーブル
２１ａ計量装置接続部
２２ＬＥＤ導光部
２３上ケース
２４下ケース
２４ａ計量装置取付部
１０１，２０１端子先端保護部
１０１ａ，２０１ａ先端部
１０１ｂ，２０１ｂ導体接続ねじ用凹部
１０１ｃ，２０１ｃ導体挿入部
１０１ｄ爪部
１０１ｅ固定部
２０１ｆ引っ掛け部 1 Circuit section 1a Display section 1b Communication device connection section 1c Open/close detection section 1d Conductor connection section 1e Sensor connection section 1f Base mounting section 2 Sensor section 2a Sensor side circuit connection section 3, 3A Conductor 3a, 3Aa Conductor side circuit connection section 3b, 3Ab Conductor side terminal connection section 3A1 Conductor side hole section 4, 4B Base 4a, 4Ba, 4Ca Communication device connection section through hole 4b, 4Bb, 4Cb Communication device mounting section 4c, 4Bc, 4Cc Block mounting section 4d, 4Bd, 4Cd Open/close detection section through hole 4e, 4Be, 4Ce Case mounting section 4f, 4Bf, 4Cf Conductor through hole 4g, 4Bg, 4Cg Circuit mounting section 4B1 Base side recess 4C2 Terminal tip protection section
4C3 Tip 4C4 Conductor connection screw recess 4C5 Conductor insertion section 5 Case 5a Display window 5b Case side base mounting section 5c Case waterproof rib storage section 5d Case waterproof rib 5e Case side fixing screw mounting section 6 Block mounting screw 7 Conductor connection screw 8 Wire mounting screw 9 Terminal 9a Wire storage section 9b Terminal side conductor connection section 10 Block 10a Block side base mounting section 10b Cover mounting female thread section 10c Wire through hole 10d Terminal mounting section 10e Block side fixing screw mounting section 10f Block waterproof rib storage section 11 Cover 11a Detection protrusion 11b Cover waterproof rib 12 Cover mounting screw 21 Cable 21a Weighing device connection section 22 LED light guide section 23 Upper case 24 Lower case 24a Weighing device mounting section 101, 201 Terminal tip protection section 101a, 201a Tip portion 101b, 201b Conductor connecting screw recess 101c, 201c Conductor insertion portion 101d Claw portion 101e Fixing portion 201f Hook portion

Claims

a terminal block including a conductor connection screw for attaching the conductor side terminal connection portion of the conductor to the terminal side conductor connection portion of the terminal; and a cover for covering the metering device, the communication device, and the terminal block, wherein a terminal tip protection part of an insulator is provided having a snap-fit structure fixing part having a conductor insertion part which is a recess for inserting the conductor side terminal connection portion of the conductor , a tip part covering a tip end of the conductor side terminal connection portion of the conductor and a conductor connection screw recess and a claw part as a recess for preventing contact between the tip end of the conductor side terminal connection portion of the conductor and a screw head of the conductor connection screw, and a conductor side hole part which is a hole for engaging with the claw part of the fixing part of the terminal tip protection part and fixing the conductor, the conductor side terminal connection portion of the conductor is inserted into the conductor insertion part of the terminal tip protection part, and the fixing part of the terminal tip protection part is provided with a conductor side hole part which is a hole for engaging with the claw part of the fixing part of the terminal tip protection part and fixing the conductor side terminal connection portion of the conductor to the outside, a terminal block for connecting the conductor side terminal connection portion of the conductor to the terminal side conductor connection portion of the terminal; a terminal block for connecting the conductor side terminal connection portion of the conductor to the terminal side conductor connection portion of the terminal; a terminal block for connecting the conductor side terminal connection portion of the conductor to the terminal side conductor connection portion of the terminal;

a terminal block including a conductor connection screw for attaching the conductor side terminal connection portion of the conductor to the terminal side conductor connection portion of the terminal; and a cover for covering the metering device, the communication device, and the terminal block, wherein a conductor insertion portion is a recess into which the conductor side terminal connection portion of the conductor is inserted, and a terminal tip protection portion is provided having a conductor connection screw recess and a hook portion as a recess for preventing abutment between a tip portion covering a tip end of the conductor side terminal connection portion of the conductor and a screw head of the conductor connection screw, and a base side recess is provided in the conductor through hole of the base which is a recess that fits with the hook portion of the terminal tip protection portion, and the tip portion of the terminal tip protection portion is inserted into the conductor through hole of the base, and the hook portion of the terminal tip protection portion is attached to the base side recess of the base . and after the tip of the conductor side terminal connection part of the conductor is fitted into the terminal side recess of the terminal tip protection part , the conductor side terminal connection part of the conductor is inserted into the conductor insertion part of the terminal tip protection part and fixed; and when the metering device is attached to the terminal block, the conductor side terminal connection part of the conductor is inserted between the terminal side conductor connection part of the terminal and the screw head of the conductor connection screw, and at the same time, the screw head of the conductor connection screw is inserted into the conductor connection screw recess of the terminal tip protection part. The metering device can be attached to and assembled with the terminal block by tightening the conductor connection screw to connect the conductor side terminal connection part of the conductor to the terminal side conductor connection part of the terminal. When replacing an energized watthour meter, if the tip of the conductor side terminal connection part of the conductor accidentally comes into contact with adjacent terminals of different poles when the conductor connection screw is loosened to remove the old metering device and the new metering device is attached to the terminal block, the tip of the terminal tip protection part, which is an insulator, comes into contact before the conductor side terminal connection part of the conductor, thereby preventing a short circuit between the terminals of different poles .

a terminal block having a conductor connection screw for attaching the conductor side terminal connection portion of the conductor to the terminal side conductor connection portion of the terminal; and a cover for covering the metering device, the communication device, and the terminal block. The metering device includes a conductor insertion portion for inserting the conductor into the base, and a terminal tip protection portion of an insulator having a conductor connection screw recess as a recess for preventing abutment between a tip portion covering a tip end of the conductor side terminal connection portion of the conductor and a screw head of the conductor connection screw . The conductor side terminal connection portion of the conductor is inserted into the conductor insertion portion of the base and fixed in place in the conductor insertion portion of the base . When attaching the watt-hour meter to the terminal block, the conductor side terminal connection portion of the conductor is inserted between the terminal side conductor connection portion of the terminal and the screw head of the conductor connection screw, and at the same time, the screw head of the conductor connection screw is inserted into the conductor connection screw recess of the base, and the conductor connection screw is tightened to connect the conductor side terminal connection portion of the conductor to the terminal side conductor connection portion of the terminal, thereby attaching and assembling the metering device to the terminal block. When replacing an energized watt-hour meter, if the tip of the conductor side terminal connection portion of the conductor accidentally comes into contact with adjacent terminals of different poles when the conductor connection screw is loosened to remove the old metering device and the new metering device is attached to the terminal block, the tip of the terminal tip protection portion of the base, which is an insulator, comes into contact before the conductor side terminal connection portion of the conductor, thereby preventing a short circuit between the terminals of different poles .