JP5781485B2 - Electronic energy meter - Google Patents

Description

  The present invention relates to an electronic watt-hour meter that measures and displays the amount of power used by a power consumer such as a general household.

  For example, an electronic watt-hour meter is known as a watt-hour meter that measures and displays the amount of power used by power consumers such as ordinary households, buildings, and factories. This electronic watt-hour meter has a terminal part including an input terminal for supplying power and an output terminal for supplying power to the load, a voltage detection part for detecting a voltage applied to the input terminal, and an input terminal And a structure including a current detection unit that detects a current flowing between the output terminals, and a power calculation unit that measures the amount of power from the voltage detected by the voltage detection unit and the current detected by the current detection unit. It has.

  As for the current detection part of this electronic watt-hour meter, what is comprised by the Hall element or the current transformer (CT) for instruments is common (for example, refer patent document 1).

  The current detection unit using the Hall element is a component molded with an exterior resin material such as an epoxy resin together with a core made of a magnetic material, or a component housed in an exterior case together with the core. The current detection unit composed of this Hall element is a component that integrates the Hall element and the core, mounted on a wiring board attached to the watt hour meter housing, or fixed to the housing by screws or the like. In addition, a structure in which a current line is passed through the core is provided.

  On the other hand, there are current transformers in which a core on which a coil is mounted is molded with an exterior resin material, and a core on which a coil is mounted is stored in an exterior case. The current detector configured with this current transformer is mounted on the wiring board attached to the casing of the watt hour meter, or fixed to the casing by screwing or the like. It has a structure in which a current line is passed through the core.

JP 2005-345266 A

  By the way, when the current detection unit in the electronic watt-hour meter is configured with the above-described components, the Hall element and the core, the exterior resin material for molding the core on which the coil is mounted, or the Hall element and the core, An exterior case is required to store the core on which the coil is mounted. As a result, it has been difficult to reduce the constituent material of the current detection unit by using these exterior resin materials and exterior cases.

  In addition, when the current detection unit in the electronic watt-hour meter is configured with a Hall element or a current transformer as described above, the Hall element or the current transformer is separated from the casing of the watt-hour meter. It must be assembled as a part in its housing. For this reason, the work of assembling the Hall element and the current transformer is time-consuming, and there is a possibility that work efficiency may be reduced.

  Therefore, the present invention has been proposed in view of the above-described problems, and the object of the present invention is an electronic system that can easily reduce the constituent material of the current detection unit and improve the assembly workability of the current detection unit. It is to provide a watt-hour meter.

As technical means for achieving the above-described object, the present invention provides a terminal unit including an input terminal for supplying power and an output terminal for supplying power to a load, and a voltage applied to the input terminal. A voltage detection unit to detect, a current detection unit to detect a current flowing between the input terminal and the output terminal, and a power calculation unit to measure the amount of power from the voltage detected by the voltage detection unit and the current detected by the current detection unit In the electronic watt-hour meter provided in the housing, the current detection unit forms a slit in the housing unit integrally provided in the housing and forms a concave groove in communication with the slit in the housing. The core is housed in the part, and the wiring board on which the Hall element is mounted is fitted and held in the slit of the housing part and the concave groove of the housing, and the Hall element is arranged in the gap of the core and injected into the housing part Then filled The core and the Hall element fixed with an adhesive, characterized in that integrated into the housing.

  In the present invention, since the current detection unit is integrated into the housing with an adhesive, an exterior resin material for molding the current detection unit and an exterior case for storing the current detection unit are separated from the housing. Since it is not necessary to provide it with a body, it is possible to easily reduce the constituent material of the current detection unit. Further, the work for assembling the current detection unit is facilitated, and the work efficiency can be easily improved.

  In the present invention, it is desirable to use a hot melt adhesive made of a thermoplastic resin as the adhesive. This hot melt adhesive has a significantly shorter curing time than other adhesives made of epoxy resin, etc., so it is easy to shorten the work time for fixing the current detection part to the housing with the hot melt adhesive. I can plan. In addition, since the curing time of the hot melt adhesive is short, it is possible to easily improve the working efficiency in the production line of the electronic watt hour meter.

  According to the present invention, an exterior resin material for molding the current detection unit and an exterior case for storing the current detection unit are integrated with the housing by integrating the current detection unit into the housing with an adhesive. Since it is not necessary to provide a separate member, it is possible to easily reduce the constituent material of the current detection unit. Further, the work for assembling the current detection unit is facilitated, and the work efficiency can be easily improved. An inexpensive electronic watt-hour meter can be provided by reducing the constituent materials of the current detection unit and increasing the efficiency in the assembling work.

It is a partial perspective view which shows the state before a Hall element, a core, and a current line are assembled | attached to the accommodating part of a housing | casing in the electric current detection part comprised with the Hall element. It is a fragmentary perspective view which shows the state after attaching a Hall element and a core to the accommodating part of a housing | casing in the electric current detection part comprised by the Hall element. It is a fragmentary perspective view which shows the state which filled the hot-melt-adhesive in the accommodating part of the housing | casing with the electric current detection part comprised with the Hall element. It is a fragmentary perspective view which shows the state which made the electric current line penetrate to the accommodating part of a housing | casing in the electric current detection part comprised with the Hall element. It is a fragmentary perspective view which shows the state before a CT structure and a current line are assembled | attached to the accommodating part of a housing | casing in the electric current detection part comprised by CT structure. It is a fragmentary perspective view which shows the state after the CT structure was assembled | attached to the accommodating part of the housing | casing in the electric current detection part comprised with CT structure. It is a fragmentary perspective view which shows the state which filled the hot-melt-adhesive in the accommodating part of the housing | casing with the electric current detection part comprised with CT structure. It is a fragmentary perspective view which shows the state which made the electric current line penetrate to the accommodating part of a housing | casing in the electric current detection part comprised with CT structure. It is a front view which shows the external appearance of an electronic watt-hour meter in embodiment of this invention. It is a block diagram which shows schematic structure of an electronic watt-hour meter. It is a fragmentary perspective view for demonstrating the detection principle of the electric current detection part comprised with the Hall element.

  Embodiments of an electronic watt-hour meter according to the present invention will be described in detail below.

  As shown in FIGS. 9 and 10, the electronic watt-hour meter includes a terminal portion 3 including an input terminal 1 for supplying power and an output terminal 2 for supplying power to a load, and an input terminal 1. A voltage detection unit 4 that detects an applied voltage, a current detection unit 5 that detects a current flowing between the input terminal 1 and the output terminal 2, and a voltage detected by the voltage detection unit 4 and a current detection unit 5 The housing 8 includes a power calculation unit 6 that measures the amount of power from the measured current and a display unit 7 that displays the amount of power measured by the power calculation unit 6.

  An input terminal 1 (power supply side terminal) to which a lead-in wire from the power supply facility 9 is connected by screwing or the like, and an output terminal 2 (load-side terminal) to which a lead-in wire to the load 10 in the electric power consumer is connected by screwing or the like. Is attached to the lower part of the housing 8 as a terminal block. Further, the voltage detection unit 4, the current detection unit 5, the power calculation unit 6, and the display unit 7 described above are built in the upper part of the housing 8.

  The current detector 5 of this electronic watt-hour meter is configured by a Hall element or a current transformer (CT). In the following embodiments, an electronic watt-hour meter including the current detection unit 5 configured by a Hall element is illustrated. As shown in FIG. 11, the current detection unit 5 has a structure in which a Hall element 13 is disposed in a gap 12 of a core 11 made of a magnetic material, and a current line 14 is passed through the center of the core 11.

  In the current detection unit 5, when a current flows through the current line 14, a magnetic field is generated in the core 11, and the Hall element 13 detects the current by converting the voltage into a voltage proportional to the magnetic field generated in the core 11. . When the mutual positional relationship between the core 11 and the Hall element 13 changes, the current detection characteristics also change. Therefore, it is necessary to fix the core 11 and the Hall element 13 in order to maintain the mutual positional relationship between the core 11 and the Hall element 13.

  Therefore, as shown in FIG. 1 to FIG. 4, the current detection unit 5 of the electronic watt-hour meter in this embodiment attaches the core 11 and the hall element 13 constituting the current detection unit to each other by using a thermoplastic resin. It has a structure integrated with a part of the casing 8 of the electronic watt-hour meter with a hot melt adhesive 15 as an agent. The adhesive may be made of a thermoplastic resin other than the hot melt adhesive 15, or a thermosetting resin or a photocurable resin.

  That is, the core 11 is stored in the cylindrical housing portion 17 provided integrally with the bottom portion 16 of the housing 8 and the hall element 13 is disposed in the gap 12 of the core 11. Stored. The hot melt adhesive 15 is injected into the accommodating portion 17 in which the core 11 and the hall element 13 are stored. The core 11 and the Hall element 13 are fixed by the hot melt adhesive 15 filled in the housing portion 17.

  The hot melt adhesive 15 is a 100% solid adhesive that does not contain any organic solvent mainly composed of a thermoplastic resin, and is solid or semi-solid at room temperature. The hot melt adhesive 15 is melted by heating and solidifies by cooling for about several minutes to complete the bonding.

  As shown in FIG. 1, the Hall element 13 is mounted below the wiring board 18. On the other hand, the bottom 16 of the casing 8 of the electronic watt-hour meter is integrally provided with a rectangular cylindrical housing portion 17 that matches the shape of the core 11 as described above. Is formed with a rectangular hole 21 through which the belt-like current line 14 passes.

  A slit 23 into which the above-described wiring board 18 is fitted is formed in the side wall part 22 of the housing part 17, and a concave groove 24 into which the wiring board 18 is fitted into the bottom part 16 of the housing 8. It is formed in communication.

  As shown in FIG. 2, the core 11 is stored in the housing portion 17 of the bottom portion 16 of the housing 8, and the wiring board 18 on which the Hall element 13 is mounted is connected to the slit 23 and the bottom portion 16 of the housing portion 17 of the housing 8. It is held upright by being fitted into the groove 24. In this manner, the Hall element 13 is stored in the accommodating portion 17 in a state where the Hall element 13 is disposed in the gap 12 of the core 11.

  As shown in FIG. 3, hot melt adhesive 15 is injected into the accommodating portion 17 in which the core 11 and the hall element 13 of the wiring board 18 are stored. The core 11 and the Hall element 13 are fixed by the hot melt adhesive 15 filled in the housing portion 17. Then, as shown in FIG. 4, the current detection unit 5 is formed by passing the current line 14 through the rectangular hole 21 of the housing unit 17. In the current detection unit 5, when a current flows through the current line 14, a magnetic field is generated in the core 11, and the current is detected by the Hall element 13 by converting the voltage into a voltage proportional to the magnetic field generated in the core 11.

  In the current detection unit 5 described above, the core 11 and the Hall element 13 are molded into a part of the casing 8 with the hot melt adhesive 15 by molding the core 11 and the Hall element 13 as in the past. For this reason, it is not necessary to provide the exterior resin material for housing and the exterior case for storing the core 11 and the hall element 13 separately from the housing 8, and therefore, the constituent materials of the current detection unit 5 can be easily reduced. Further, the work for assembling the core 11 and the hall element 13 is facilitated, and the working efficiency can be easily improved.

  The hot melt adhesive 15 for fixing the core 11 and the hall element 13 in the housing portion 17 of the housing 8 is made of an adhesive made of another thermoplastic resin such as an epoxy resin (curing time is about 12 hours). Since the curing time (about 5 minutes) is remarkably short, it is possible to easily shorten the work time for fixing the core 11 and the hall element 13 in the housing portion 17 of the housing 8 with the hot melt adhesive 15. . Thus, since the curing time of the hot melt adhesive 15 is short, it is possible to easily improve the working efficiency in the production line of the electronic watt-hour meter.

  As described above, the hot melt adhesive 15 is filled in the housing portion 17 in which the core 11 and the hall element 13 are stored, so that the core 11 and the hall element 13 can be fixed inside the housing portion 17. Thereby, it becomes easy to maintain the mutual positional relationship between the core 11 and the Hall element 13, and it is possible to prevent characteristic changes due to positional deviation between the core 11 and the Hall element 13. As described above, after the core 11 and the hall element 13 are fixed, the current is detected with the characteristics based on the mutual positional relationship between the core 11 and the hall element 13.

  In the above embodiment, the case where the core 11 and the Hall element 13 are used as the current detection unit has been described. However, a current transformer (CT) for a meter can also be used as another current detection unit. In the embodiment shown in FIGS. 5 to 8, an electronic watt hour meter including the current detection unit 5 configured by the CT structure 28 is illustrated. As shown in FIGS. 5 to 8, the current detection unit 5 of the electronic watthour meter in this embodiment includes a CT structure 28 in which a coil 30 is attached to a core 29 made of a magnetic material. It has a structure integrated with a hot melt adhesive 35 in a state of being stored in the accommodating portion 31 of the housing 8.

  As shown in FIG. 5, the CT structure 28 is obtained by winding a coil 30 around the outer periphery of the core 29. On the other hand, as described above, a circular cylindrical housing 31 that matches the shape of the CT structure 28 is integrally projected from the bottom 16 of the casing 8 of the electronic watt-hour meter. A rectangular hole 32 for penetrating the belt-like current line 14 is formed in the center of the.

  As shown in FIG. 6, the CT structure 28 is stored in the accommodating portion 31 of the bottom portion 16 of the housing 8. At this time, the winding start end 33 and the winding end end 34 of the coil 30 in the CT structure 28 are derived. As shown in FIG. 7, hot melt adhesive 35 is injected into the accommodating portion 31 in which the CT structure 28 is stored. The CT structure 28 is fixed by the hot melt adhesive 35 filled in the accommodating portion 31. Then, as shown in FIG. 8, the current detection unit 5 is formed by passing the current line 14 through the rectangular hole 32 of the housing unit 31.

  In the current detection unit 5 described above, the CT structure 28 is integrated into a part of the housing 8 with the hot melt adhesive 35, so that the exterior resin for molding the CT structure 28 as in the past is used. Since it is not necessary to provide a material and an exterior case for storing the CT structure 28 separately from the housing 8, it is possible to easily reduce the constituent material of the current detection unit 5. Further, the work for assembling the CT structure 28 is facilitated, and the work efficiency can be easily improved.

  Also, the hot melt adhesive 35 for fixing the CT structure 28 in the housing portion 31 of the housing 8 has a significantly shorter curing time than an adhesive made of another thermoplastic resin such as an epoxy resin. The working time for fixing the CT structure 28 in the housing portion 31 of the housing 8 with the hot melt adhesive 35 can be easily reduced. Thus, since the curing time of the hot melt adhesive 35 is short, it is possible to easily improve the working efficiency in the production line of the electronic watt-hour meter.

  The present invention is not limited to the above-described embodiments, and can of course be implemented in various forms without departing from the gist of the present invention. It includes the equivalent meanings recited in the claims and the equivalents recited in the claims, and all modifications within the scope.

DESCRIPTION OF SYMBOLS 1 Input terminal 2 Output terminal 3 Terminal part 4 Voltage detection part 5 Current detection part 6 Power operation part 8 Case 11 Current detection element (core)
13 Current detection element (Hall element)
15 Adhesive (hot melt adhesive)
17 Housing portion 28 Current detection element (CT structure)
29 Current detection element (core)
30 Coil 31 Housing part 35 Adhesive (hot melt adhesive)

Claims (2)

A terminal unit including an input terminal for supplying power and an output terminal for supplying the power to a load; a voltage detection unit for detecting a voltage applied to the input terminal; and the input terminal and the output terminal. An electronic watt-hour meter provided with a current detection unit that detects a flowing current, and a power calculation unit that measures a power amount from the voltage detected by the voltage detection unit and the current detected by the current detection unit The current detection unit includes a slit formed in a housing unit provided integrally with the housing, a concave groove communicating with the slit is formed in the housing, a core is stored in the housing unit, and a Hall element The wiring board mounted with is fitted and held in the slit of the housing part and the groove of the housing, and the Hall element is arranged in the gap of the core, and injected into the housing part and filled with the adhesive. Core Electronic electricity meter, characterized in that integrated into the housing to secure the Hall element and.   The electronic watt-hour meter according to claim 1, wherein the adhesive is a hot melt adhesive made of a thermoplastic resin.

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