JP2018004379A - Electronic watt-hour meter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic watt-hour meter having excellent workability at assembly time of the electronic watt-hour meter.SOLUTION: Provided is an electronic watt-hour meter comprising: a current detection unit 4 for measuring a current flowing in a distribution line from the output signal of a current transformer provided on the outside; a printed wiring board 5 on which are mounted a measurement unit 5a for measuring electric energy from the current detected by the current detection unit 4 and the voltage of the distribution line and a power supply unit for supplying electric power to the measurement unit 5a; a nameplate 6 provided on the power supply unit apart from the printed wiring board 5 by a distance greater than or equal to the component height of the power supply unit; and a base 1 and a middle base 7, on which are provided a nameplate holding unit for holding the nameplate 6 and a guide unit 7a for guiding the printed circuit board 5 to an assembly position, for storing the current detection unit 4 and the printed circuit board 5.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an electronic watt-hour meter, and more particularly to a structure of an electronic watt-hour meter such as a printed wiring board fixing method.

The electronic watt-hour meter is composed of a display unit for displaying a measurement value, a measurement unit including a CPU for measurement, a rectifier, a smoothing capacitor, a transformer, a switching element, and the like, and supplies power to the measurement unit. A power supply unit is provided (see, for example, Patent Document 1).
In addition, an electronic watt-hour meter installed in a high-voltage consumer is connected to an instrument transformer and an instrument current transformer outside the electronic watt-hour meter. For this reason, the name plate of the high-voltage electronic watt-hour meter is printed or engraved with the rated items such as the transformation ratio of the instrument transformer and the meter current transformer, and the printed wiring board provided with a display unit. Is provided immediately behind the name plate (see, for example, Patent Document 2).

JP 2000-187049 A Japanese Patent Laid-Open No. 3-195975

In the conventional electronic watt-hour meter, since the printed wiring board of the measuring unit provided with the display unit was provided immediately behind the name plate, the measuring unit and the power supply unit were separate printed wiring boards. However, in recent years, in electronic watt-hour meters called smart meters equipped with a communication function that has become widespread, the weighing unit and the power supply unit may be mounted on the same printed wiring board for miniaturization and cost reduction. It is increasing.
However, since the power supply unit is mounted with high parts such as smoothing capacitors and transformers, the printed wiring board is named so that the parts such as smoothing capacitors and transformers do not hit the name plate. There is a problem that the workability when assembling a product is deteriorated because it is necessary not to be directly behind the plate but to be provided inside the electronic watt hour meter away from the name plate.

  The present invention has been made to solve the above-described problems, and an object thereof is to obtain an electronic watt-hour meter having good workability when a product is assembled.

  An electronic watt-hour meter according to the present invention includes a current detection unit for measuring a current flowing through a distribution line from an output signal of a current transformer provided outside, a power from a current detected by the current detection unit and a voltage of the distribution line. Weighing unit for measuring quantity, and printed wiring board on which the power supply unit that supplies power to this weighing unit is mounted, and the name provided above the power supply unit at a distance of the height of the power supply unit from the printed wiring board A plate, a name plate holding portion for holding the name plate, and a guide portion for guiding the printed wiring board to the assembly position, and a current detection portion and a case for storing the printed wiring board. is there.

  According to this invention, it is possible to obtain an electronic watt-hour meter with good workability when assembling a product.

It is a front view which shows the electronic watt-hour meter in Embodiment 1 of this invention. It is a top view which shows the electronic watt-hour meter in Embodiment 1 of this invention. It is a disassembled perspective view of the electronic watt-hour meter of implementation in Embodiment 1 of this invention. It is a disassembled perspective view which shows the state which assembled | attached the middle base and the printed wiring board to the base from the state of FIG. It is an enlarged front view which shows the state which removed the cover and the terminal cover from the state of FIG. It is a front view which shows the printed wiring board of FIG. It is a perspective view which shows the principal part of the middle base shown in FIG. It is a principal part expansion perspective view which shows the snap fit part shown in FIG. It is a front view which shows the state which removed the name plate from the state of FIG. It is explanatory drawing for demonstrating the X1-X1 arrow cross section in FIG. 9, and explaining attachment of a printed wiring board. FIG. 10 is a perspective view illustrating a state in which the printed wiring board described in FIG. 9 has been attached. It is a perspective view which shows the state which attached the nameplate from the state of FIG. It is a front view which shows the printed wiring board in Embodiment 2 of this invention. It is a perspective view which shows the state which removed the cover, the terminal cover, the printed wiring board, and the name board in the electronic watt-hour meter in Embodiment 2 of this invention. It is a principal part expansion perspective view which shows the snap fit part shown in FIG. It is a perspective view which shows the state which assembled | attached the printed wiring board from the state of FIG. It is a perspective view which shows the state which assembled | attached the name plate from the state of FIG.

Embodiment 1 FIG.
1 is a front view showing an electronic watt-hour meter according to Embodiment 1 of the present invention, FIG. 2 is a top view of FIG. 1, and FIG. 3 is an exploded perspective view showing the electronic watt-hour meter according to Embodiment 1 of the present invention. 4 is an exploded perspective view showing a state in which the middle base and the printed wiring board are assembled to the base from the state of FIG. 3, FIG. 5 is a front view showing a state in which the cover and the terminal cover are removed from the state of FIG. 3 is a front view showing the printed wiring board of FIG. 3, FIG. 7 is a perspective view showing the main part of the middle base shown in FIG. 1, and FIG. 8 is an enlarged perspective view of the main part showing the snap-fit part shown in FIG. (B) is an enlarged perspective view showing the other, FIG. 9 is a front view showing a state in which the name plate is removed from the state shown in FIG. 5, and FIG. 10 is a cross-sectional view taken along line X1-X1 in FIG. FIG. 11 is an explanatory diagram for explaining the attachment of the plate, and FIG. 11 is a print described in FIG. Perspective view showing a state in which mounting of the linear plate is completed, FIG. 12 is a perspective view showing a state of attaching the name plate from the state of FIG. 11.

  As shown in FIGS. 1 and 2, the electronic watt-hour meter 100 includes a synthetic resin base 1, a synthetic resin cover 2 fitted to the base 1, and a synthetic resin terminal cover 3. The casing is configured.

  In addition, as shown in FIG. 3, a current for measuring a current flowing through the distribution line from an output signal of a current transformer provided outside the electronic watt-hour meter 100 is provided inside the housing of the electronic watt-hour meter 100. The measuring unit 5a (shown in FIG. 6) for measuring the amount of electric power from the detection unit 4, the current detected by the current detecting unit 4 and the voltage of the distribution line, and the power source unit 5b (FIG. 6) for supplying power to the measuring unit 5a And the printed wiring board 5 on which the display unit 5c for displaying the amount of power measured by the measuring unit 5a is mounted, and the distance above the power supply unit 5b from the printed wiring board 5 on the power supply unit 5b. A name plate 6 provided apart from the base plate 1, a name plate holding portion for holding the name plate 6, and a guide portion 7 a for guiding the printed wiring board 5 to the assembly position. 4 and a base 7 that fits into the base 1 and a base 1 fitted, a cover 2 for housing the printed circuit board 5 and the name plate 6, and a terminal cover 3 which covers the communication device mounting space of the terminal portion 1a and the middle base 7 of the base 1, a.

  As shown in FIG. 4, the printed wiring board 5 is held at the assembly position by snap fit portions 7 b 1 and 7 b 2 provided on the middle base 7. Here, the terminal cover 3 is not illustrated.

As shown in FIG. 5, the current detector 4 that measures the current supplied to the load connected to the electronic watt-hour meter 100 includes the current line 4a that connects between the terminal 1a1 and the terminal 1a7, and the terminal 1a3 and the terminal The currents flowing in the current lines 4b connecting between 1a4 are detected.
The terminals 1a2, 1a5, 1a6 are terminals for voltage input, and the terminals 1a2, 1a5, 1a6 are connected to the printed wiring board 5 by electric wires (not shown). The voltage input to the printed wiring board 5 is used for measuring the amount of electric power by the measuring unit 5a and also used as a power source for the power source unit 5b.

Next, the printed wiring board 5, the name plate 6, and the middle base 7 will be described.
As shown in FIG. 6, the printed wiring board 5 includes a measuring unit 5 a that measures the amount of power from the current detected by the current detecting unit 4 and the voltage (for example, AC 100 V) input to the terminals 1 a 2, 1 a 5, and 1 a 6. A power supply unit 5b for supplying power to the measuring unit 5a, a display unit 5c for displaying the amount of power measured by the measuring unit 5a, A notch portion 5d corresponding to the guide portion 7a when assembled to the base 7 is provided.

As shown in FIG. 5, the name plate 6 includes a printing unit 6 a on which rated items of a current transformer provided outside the electronic watt-hour meter 100 are printed, and a display unit 5 c provided on the printed wiring board 5. And a display hole 6b for making the display visible to the outside.
As shown in FIG. 7, the middle base 7 has a guide portion 7 a for guiding the printed wiring board 5 to the assembly position, snap fit portions 7 b 1 and 7 b 2 for holding the printed wiring board 5, and a printed wiring board. 5 is provided on the side of the middle base terminals 1a1 to 1a7, and name plate holding portions 7d1 to 7d4 for holding the name plate 6 are provided.

As shown in FIG. 7, the guide portion 7a includes a first guide portion 7a1 provided closest to the name plate 6, a second guide portion 7a2 protruding from the first guide portion 7a1, and a second guide portion 7a2. The first guide portion 7a1 and the second guide portion 7a2 are connected with a gradient, and the gradient portion 7a3 guides the printed wiring board 5 to the assembly position. And the 1st guide part 7a1 is extended to the back surface vicinity of the printing part 6a in the name board 6 so that the printed wiring board 5 can be correctly guided to an installation position.
As shown in FIGS. 3 and 9, the gradient portion 7a3 has a first gradient 7a3a that is an inclined surface on the terminal portion 1a side, and a second gradient 7a3b that is an inclined surface on the right side of FIG.
Further, “projected from the first guide portion 7a1 to the assembly position” means the terminal portion 1a side of the first gradient 7a3a and the right side of FIG. 9 of the second gradient 7a3b.

  As shown in FIG. 8, the snap-fit portions 7b1 and 7b2 are formed of first coupling portions 7b1a and 7b2a for locking the printed wiring board 5 in the direction along the guide portion 7a, and the first coupling portions 7b1a and 7b2a. A second direction for locking the printed wiring board 5 in a direction perpendicular to the locking direction and the direction in which the first coupling portions 7b1a and 7b2 open when the printed wiring board 5 gets over the first coupling portions 7b1a and 7b2a. The coupling portions 7b1b and 7b2b, and the elastic portions 7b1c and 7b2c that are bent when the printed wiring board 5 gets over the first coupling portions 7b1a and 7b2a, respectively.

As shown in FIG. 7, when the printed wiring board 5 is assembled, the holding portion 7c holds the printed wiring board 5 before being locked to the snap-fit portions 7b1 and 7b2. It is the rib provided in the wall by the side of 1a7.
The name plate holding portions 7d1 to 7d4 are provided on the power supply portion 5b in the middle base 7 at positions separated from the printed wiring board 5 by the height of the component of the power supply portion 5b.

  In addition, the “case” described in the claims means a base 1 on which the current detection unit 4 is disposed, and covers the base 1, and guide portions 7a, snap fit portions 7b1, 7b2, and a name plate holding portion. The middle base 7 provided with 7d1 to 7d4.

Next, a procedure for assembling the printed wiring board 5 to the assembly position of the middle base 7 will be described.
As shown in FIG. 10, first, the printed wiring board 5 is inserted obliquely, and one end portion of the printed wiring board 5 on the lower side of the sheet of FIG. 10 is brought into contact with the holding portion 7c of the middle base 7 (see FIG. 10). A state shown).

Next, when the printed wiring board 5 is inserted along the first guide portion 7a1 and the gradient portion 7a3 so as to rotate the other end portion of the printed wiring board 5 around the one end portion of the printed wiring board 5, the gradient is obtained. The notched portion 5d (shown in FIG. 6) of the printed wiring board 5 abuts on the portion 7a3, and the printed wiring board 5 is pushed out in the direction of the terminal portion 1a, which is the downward direction in FIG. The other end engages with the holding portion 7c (state B shown in FIG. 10).
At the same time, as shown in FIG. 9, the printed wiring board 5 is pushed out to the right side of the sheet by the second gradient 7 a 3 b of the gradient portion 7 a 3 and comes into contact with the wall surface 7 e of the middle base 7.

  Next, when the elastic portions 7b1c and 7b2c are bent and the snap fit portions 7b1 and 7b2 are pushed and further pushed over the first coupling portions 7b1a and 7b2a, the printed wiring board 5 becomes the first coupling portion. In addition to engaging with 7b1a and 7b2a, the second coupling portions 7b1b and 7b2b are also engaged and fixed (state C shown in FIG. 10). FIG. 11 also shows a state in which the printed wiring board 5 is held by the snap fit portions 7 b 1 and 7 b 2 and fixed to the middle base 7.

  After the printed wiring board 5 is attached to the middle base 7, as shown in FIG. 12, the name board 6 is held by the name board holding portions 7 d 1 to 7 d 4 and attached to the middle base 7. Since the display hole 6b of the name plate 6 is fixed at the position of the display unit 5c, the display of the display unit 5c can be seen from the display hole 6b. Further, since the guide portion 7a is disposed directly behind the printing portion 6a, in this state, the transformation of the instrument transformer (transformer or current transformer) easily provided outside the electronic watt-hour meter 100 is achieved. Rating items such as ratio can be printed with a stamp or the like.

  According to the present embodiment, the current detector 4 that measures the current flowing through the distribution line from the output signal of the current transformer provided outside the electronic watt-hour meter 100, the current detected by the current detector 4 and A printed wiring board 5 on which a weighing unit 5a for measuring the amount of power from the voltage of the distribution line, a power supply unit 5b for supplying power to the weighing unit 5a is mounted, and a power supply unit from the printed wiring board 5 on the power supply unit 5b. A name plate 6 provided at a distance of at least the component height of 5b, name plate holding portions 7d1 to 7d4 for holding the name plate 6, and a guide portion 7a for guiding the printed wiring board 5 to the assembly position are provided. Since the base 1 and the middle base 7 that house the current detection unit 4 and the printed wiring board 5 are provided, the workability when assembling the electronic watt-hour meter 100 can be improved.

  Further, the name plate 6 has a printing portion 6a on which the rated items of the current transformers provided on the outside are printed, and the guide portion 7a extends to the back surface of the printing portion 6a, so the name plate 6 is attached. In the state, the rated items such as the transformation ratio of the instrument transformer (transformer or current transformer) can be easily printed with a stamp or the like.

  The guide portion 7a includes a first guide portion 7a1 provided closest to the name plate 6, a second guide portion 7a2 protruding from the first guide portion 7a1 to the assembly position side of the printed wiring board 5, and And a slope portion 7a3 for connecting the first guide portion 7a1 and the second guide portion 7a2 with a slope to guide the printed wiring board 5 to the assembly position. 5 can be easily inserted.

  The middle base 7 has snap-fit portions 7b1 and 7b2 that hold the printed wiring board 5 in the assembly position. The snap-fit portions 7b1 and 7b2 lock the printed wiring board 5 in the direction along the guide portion 7a. The printed wiring board 5 is locked in a direction perpendicular to the first coupling portions 7b1a and 7b2a to be engaged with the first coupling portions 7b1a and 7b2a and the direction in which the first coupling portions 7b1a and 7b2a are opened. Since the second coupling portions 7b1b and 7b2b are provided, the printed wiring board 5 can be reliably held at the assembly position.

Embodiment 2. FIG.
FIG. 13 is a front view showing a printed wiring board 51 according to the second embodiment of the present invention, and FIG. FIG. 15 is an enlarged perspective view of a main part showing a snap fit portion shown in FIG. 14, and FIG. 16 is a perspective view showing a state where a printed wiring board is assembled from the state of FIG. 17 is a perspective view showing a state in which the name plate is assembled from the state of FIG.
Depending on the model of the electronic watt-hour meter, such as when the communication unit is mounted on the same printed wiring board as the weighing unit, it is necessary to increase the effective area of the printed wiring board for mounting the components, as in the first embodiment. In some cases, the printed wiring board 5 may not be provided with the notch 5d.

The printed wiring board 51 of the electronic watt-hour meter 101 according to the present embodiment has a rectangular shape as shown in FIG. 13 and is not provided with a notch.
For this reason, the printed wiring board 51 needs to be assembled to the middle base 7 of the electronic watt-hour meter 101 from a different direction from the case of the first embodiment.
Therefore, the guide portion 7a is provided with a notch groove portion 7a4 for inserting the printed wiring board 51 from the opposite direction to the terminal portion 1a.

Further, as shown in FIG. 15, the snap-fit portions 7b3 and 7b4 are arranged in the direction opposite to the terminal portion 1a and the first coupling portions 7b3a and 7b4a for locking the printed wiring board 51 in the direction along the guide portion 7a. Second coupling portions 7b3b and 7b4b for locking the printed wiring board 51, and elastic portions 7b3c and 7b4c which are bent when the printed wiring board 51 gets over the second coupling portions 7b3b and 7b4b, respectively. .
The second coupling portions 7b3b and 7b4b are inclined surfaces 7b3b1 and 7b4b1 that bend the elastic portions 7b3c and 7b4c in a direction in which the printed wiring board 51 can easily get over the second coupling portions 7b3b and 7b4b when the printed wiring board 51 is assembled. Are provided.
Since other configurations are the same as those in the first embodiment, detailed description thereof is omitted.

Next, assembly of the printed wiring board 51 to the assembly position of the middle base 7 will be described.
Since the printed wiring board 51 does not have a notch, the printed wiring board 51 is inserted into the middle base 7 from the direction indicated by the arrow D as shown in FIG. At this time, one end of the printed wiring board 51 hits the slopes 7b3b1 and 7b4b1 of the second coupling portions 7b3b and 7b4b to bend the elastic portions 7b3c and 7b4c, thereby getting over the second coupling portions 7b3b and 7b4b.

  Furthermore, one end of the printed wiring board 51 is guided by the notch groove portion 7a4 provided in the guide portion 7a, and is inserted to the assembly position. When the other end of the printed wiring board 51 gets over the second coupling portions 7b3b and 7b4b, the printed wiring board 51 is held by the snap-fit portions 7b3 and 7b4 and fixed to the middle base 7.

    After the printed wiring board 51 is attached to the middle base 7, as shown in FIG. 17, the name board 6 is held by the name board holding portions 7 d 1 to 7 d 4 and attached to the middle base 7. Since the display hole 6b of the name plate 6 is fixed at the position of the display part 51c, the display of the display part 51c can be seen from the display hole 6b. Further, since the guide portion 7a is disposed directly behind the printing portion 6a, in this state, the transformation of the instrument transformer (transformer or current transformer) easily provided outside the electronic watt-hour meter 101 is achieved. Rating items such as ratio can be printed with a stamp or the like.

  According to the present embodiment, the current detection unit 4 that measures the current flowing through the distribution line from the output signal of the current transformer provided outside the electronic watt-hour meter 101, the current detected by the current detection unit 4 and A printed wiring board 51 on which a measuring unit 51a that measures the amount of power from the voltage of the distribution line, a power supply unit 51b that supplies power to the measuring unit 51a, and a power supply unit from the printed wiring board 51 on the power supply unit 51b are mounted. A name plate 6 provided at a distance equal to or higher than the component height of 51b, name plate holding portions 7d1 to 7d4 for holding the name plate 6, and a guide portion 7a for guiding the printed wiring board 51 to the assembly position are provided. Since the base 1 and the middle base 7 that house the current detection unit 4 and the printed wiring board 51 are provided, the workability when assembling the electronic watt-hour meter 101 can be improved.

  Further, the name plate 6 has a printing portion 6a on which the rated items of the current transformers provided on the outside are printed, and the guide portion 7a extends to the back surface of the printing portion 6a, so the name plate 6 is attached. In the state, the rated items such as the transformation ratio of the instrument transformer (transformer or current transformer) can be easily printed with a stamp or the like.

  Further, the guide portion 7a has a notch groove portion 7a4 for incorporating the printed wiring board 51 into the middle base 7. The second coupling portions 7b3b and 7b4b are formed by the printed wiring board 51 when the printed wiring board 51 is assembled. Since the slopes 7b3b1 and 7b4b1 are provided to bend the snap fitting portions 7b3 and 7b4 in a direction that makes it easy to get over the two coupling portions 7b3b and 7b4b, the workability when assembling the electronic watt-hour meter 101 is improved.

1 base, 2 cover, 3 terminal cover,
4 Current detector, 4a, 4b Current line,
5 Printed wiring board, 5a Weighing unit, 5b Power supply unit, 5c Display unit,
6 name plate, 6a printing part, 6b display hole,
7 middle base, 7a guide part, 7b1, 7b2 snap fit part,
7d1-7d4 Name plate holder, 100 electronic watt-hour meter.

Claims (5)

  A current detection unit that measures the current flowing through the distribution line from the output signal of the current transformer provided outside, a measurement unit that measures the amount of power from the current detected by the current detection unit and the voltage of the distribution line, and the measurement A printed wiring board on which a power supply unit for supplying power to the unit is mounted, a name plate provided on the power supply unit at a distance of at least a component height of the power supply unit from the printed wiring board, and the name plate An electronic watt-hour meter provided with a name plate holding portion to be held and a guide portion for guiding the printed wiring board to an assembly position and housing the current detection portion and the printed wiring board.   2. The electronic power according to claim 1, wherein the name plate has a printing portion on which rated items of the current transformer are printed, and the guide portion extends to a back surface of the printing portion. Quantity meter.   The guide portion includes a first guide portion provided closest to the name plate side, a second guide portion protruding from the first guide portion toward the assembly position, the first guide portion, and the first guide portion. The electronic watt-hour meter according to claim 2, further comprising a slope portion that connects the two guide portions with a slope and guides the printed wiring board to the assembly position.   The case includes a snap fit portion that holds the printed wiring board in the assembled position, and the snap fit portion includes a first coupling portion that locks the printed wiring board in a direction along the guide portion. And a second coupling portion that latches the printed wiring board in a direction perpendicular to the locking direction of the first coupling portion and the direction in which the first coupling portion opens. The electronic watt-hour meter as described in any one of Claims 1-3.   The guide portion has a notch groove portion for assembling the printed wiring board into the case, and the second coupling portion facilitates the printed wiring board to get over the second coupling portion during the assembly. The electronic watt-hour meter according to claim 4, further comprising a slope that deflects the snap fit portion in a direction.

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