JPH10197574A - Electronic watt-hour meter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce an installing height of a current transformer, and realize a thin type by arranging the axial direction of a current transformer through hole through which a short-circuit bar is penetrated, in the direction for crossing at a right angle to a bottom surface of a base. SOLUTION: A short-circuit bar 16 is integrally formed by welding a short- circuit bar 16b by bending to a plate-like short-circuit bar 16a. When a current transformer 15 is installed on a base 10, the current transformer 15 is arranged so that the axial direction of a current transformer 15 through hole 15b into which the short-circuit bar 16 is penetrated crosses at a right angle to a bottom surface 10a of the base 10. Therefore, since the current transformer 15 is arranged in a plane shape on the bottom surface 10a of the base 10, a height up to an upper end part of the current transformer 15 from the bottom surface 10a is reduced. Therefore, the whole height H of a watt-hour meter can be reduced, and even if the size of the current transformer 15 is largely changed, wiring can be performed only by changing a shape of the short-circuit bar 16, and since there is no need to change an inter-terminal dimension on the load side, the inter-terminal dimension can be standardized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure of a through-type current transformer mounted on, for example, an electronic wattmeter and detecting a current proportional to a load current.

[0002]

2. Description of the Related Art FIGS.
568 is a diagram showing a current transformer mounting structure of the conventional single-phase two-wire electronic wattmeter, FIG. 5 is a plan view, FIG. 6 is a cross-sectional view along line VI-VI, FIG. 7 is an exploded perspective view. In FIG. 5, reference numeral 1 denotes a base made of an iron plate material;
Is a terminal block made of an insulating material, which is fixed to the base 1. Power supply terminals 3a to 3c and load terminals 4a to 4c are held and fixed to the terminal block 2 at predetermined intervals. Current transformers 5a and 5c detect a current proportional to the load current. As shown in FIGS.
The through-hole 5d is vertically mounted such that the axial direction of the through-hole 5d is parallel to the bottom surface 1a of the base 1 as shown in FIG. Load side terminals 4a, 4c are current transformers 5a, 5c
Short-circuit bars 6a and 6b that penetrate through holes 5d of
Are connected to the power-supply-side terminals 3a and 3c by means of washers 7 and terminal tightening screws 8. The bottom portions 5e of the current transformers 5a and 5c are formed in a planar shape so as to be a reference surface at the time of installation. Reference numeral 9 denotes an internal terminal board, as shown in FIGS. 6 and 7, a board portion 9a and bottom portions 5e of current transformers 5a and 5c.
And a fixed reference portion 9b which is attached in contact therewith.

In the electronic watt-hour meter configured as described above, the current transformers 5a and 5c are mounted by inserting two load terminals 4a and 4c into through holes 5d of the current transformers 5a and 5c. The current transformers 5a and 5c are supported, and short-circuit bars 6a are provided at the ends of the load terminals 4a and 4c protruding from the through holes 5d.
6b, and one side surface of the current transformers 5a, 5c is supported in contact with the end of the substrate 9a. Also,
As a detent of the current transformers 5a and 5c, a fixed reference portion 9b provided on the internal terminal board 9 and a planar bottom portion 5e of the current transformers 5a and 5c abut.

[0004]

In the above-mentioned conventional electronic watt-hour meter, the current transformers 5a and 5c are provided with through holes 5d.
Is mounted vertically so as to be parallel to the bottom surface 1a of the base 1, so that the height H1 from the bottom surface 1a of the base 1 to the upper end portions of the current transformers 5a and 5c increases as shown in FIG.
In addition, there is a problem that the height of the electronic watt-hour meter increases. Further, there is a problem that the terminal distance L1 (shown in FIG. 5) between the load terminals 4a and 4c changes depending on the size of the current transformers 5a and 5c, and it is difficult to standardize the terminal distance. Further, load-side terminals 4a, 4c and short-circuit bar
Since the current transformers 5a and 5c are pressed and fixed by 6a and 6b, and the conductive portions are in contact with the cases (not shown) of the current transformers 5a and 5c, the secondary coils of the current transformers 5a and 5c ( (Not shown)), and there is a problem that it is difficult to secure a predetermined insulation performance.

The present invention has been made to solve such a problem, and a first object of the present invention is to provide a thin electronic watt-hour meter having a low current transformer mounting height. .
A second object is to obtain an electronic watt-hour meter with improved insulation performance.

[0006]

In an electronic watt-hour meter according to the present invention, an insulated housing including a base and a cover, a terminal block mounted inside the insulated housing, and an external housing mounted on the terminal block are provided. A power-supply-side terminal and a load-side terminal to which wiring is connected, a short-circuit bar connected between the power-supply terminal and the load-side terminal, and a through-hole through which the short-circuit bar penetrates as a primary coil; A current transformer is provided in which the axial direction of the hole is orthogonal to the bottom surface of the base and detects a current proportional to the current flowing through the primary coil.

A first projection protruding from the end face of the base and supporting one end face of the current transformer orthogonal to the axial direction of the through hole; a carrier disposed on the other end face side of the current transformer; A second projection projecting from the carrier and supporting the other end surface of the current transformer.

Further, the short-circuit bar is formed of a first flat short-circuit bar and a bar connected to the first short-circuit bar and having a bent portion penetrating a through hole of the current transformer. 2
And a short bar.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. 1 to 3 show a three-phase four-wire electronic wattmeter according to an embodiment of the present invention.
FIG. 2 is a plan view showing the inside with the cover cut away, FIG. 2 is a sectional view taken along line II-II in FIG. 1, and FIG. 3 is a sectional view taken along line III-III in FIG. In FIG. 1, reference numeral 10 denotes a base, and 11 denotes a cover, each of which is an insulating casing formed of a synthetic resin material. Reference numeral 12 shown in FIG. 3 denotes a terminal block mounted on the base 10, which is made of a synthetic resin material, and to which external wiring is connected as shown in FIG.
Are mounted at intervals of a predetermined distance L2 between terminals. Fifteen
Is a through-type current transformer for detecting a current proportional to the load current. A secondary coil is wound around a bobbin 15a having a through hole 15b and an outer peripheral portion formed of a synthetic resin material in a substantially circular shape. The core 15c is accommodated, and as shown in FIG. 2, the end portion is filled with an insulating member 15d such as silicon rubber or polyurethane rubber. Reference numeral 15e shown in FIG. 1 denotes a secondary coil outlet of the current transformer 15, and a partition wall 1 described later.
The current transformer 15 protrudes from the groove of Ob to prevent rotation. Reference numeral 16 denotes a short-circuit bar that electrically connects the power-supply-side terminal 13 and the load-side terminal 14 and serves as a primary coil of the current transformer 15, and is a first short-circuit bar 16a formed by punching and bending a flat copper plate. And a second short-circuit bar 16b formed by bending a copper round bar and passing through the through hole 15b of the current transformer 15.
Each end is connected to the power supply terminal 13 or the load terminal 14 by a bolt 17.

Reference numeral 10b denotes a partition wall, which protrudes from the bottom surface 10a of the base 10 as shown in FIG. 2 and is formed so as to surround an outer peripheral portion of the current transformer 15 as shown in FIG. A plurality of small projections 10c with which the outer peripheral portion of the current transformer 15 abuts are formed, and the current transformer 15 is housed therein. Reference numeral 10d denotes a plurality of first protrusions formed to protrude from a bottom surface 10a, which is an end surface of the base 10, as shown in FIG. I have. Reference numeral 20 denotes a substrate case, which is a carrier, preferably formed of a synthetic resin material, and supports a printed circuit board 23 to which an electronic circuit component 21 and a transformer 22 are soldered as shown in FIG. Base 10 of base 10
It is supported so as to be snap-fitted to a post 10f having a U-groove 10e protruding from a. Reference numeral 20a denotes a plurality of second protrusions protruding from the lower surface of the board case 20. The tip ends of the second protrusions are formed by an insulating member 15d as the other end face of the current transformer 15 when the board case 20 is mounted on the post 10f. The current transformer 15 is supported between the first protrusion 10 d that is pressed and protrudes from the base 10. 25 is a board cover, 26 is a nameplate, and 27 is mud glass.

FIG. 4 is a side view showing how to incorporate a current transformer into the short-circuit bar. The short-circuit bar 16 is a first flat plate.
The bent second short-circuit bar 16b is integrated with the short-circuit bar 16a by welding at a C portion. The current transformer 15 is assembled by first passing the through-hole 15b of the current transformer 15 through the second short-circuit bar 16b as shown by a dashed line, and then moving the current transformer 15 in the direction of the arrow to bend. Part 1
Pass through 6R and insert to the position indicated by the two-dot chain line. The shape of the bent portion 16R is such that the current transformer 15 can be moved from the position indicated by the dashed line to the position indicated by the dashed line, and the height H3 of the short-circuit bar 16 is the lowest.

In the electronic watt-hour meter constructed as described above, the current transformer 15 is attached to the base 10 when the through hole 15b of the current transformer 15 is oriented in the axial direction.
Since the second short-circuit bar 16b is penetrated through the through-hole 15b in a plane orthogonal to the direction perpendicular to the direction 0a, the base is provided like the conventional electronic watt-hour meter shown in FIG. 1, the height H1 from the bottom surface 1a to the upper ends of the current transformers 5a and 5c does not increase, and as shown in FIG. 2, the height H2 of the electronic wattmeter can be reduced. Even if the size of the wire 15 changes, wiring can be performed only by changing the shape of the short-circuit bar 16, and it is not necessary to change the terminal-to-terminal dimension L2 on the load side.

Further, one end face of the current transformer 15 orthogonal to the axial direction of the through hole 15b is supported by a first projection 10d projecting from the end face of the base 10, and the other end face of the current transformer 15 is carried. Second protrusion 20a protruding from substrate case 20 which is a body
, The current transformer 15 does not come into contact with the conductive part such as the load-side terminal 14, and the insulation performance between the secondary coil (not shown) of the current transformer 15 and the conductive part is improved. At the same time, the current transformer 15 can be fixed with elasticity, and the earthquake resistance and the shock resistance are improved.

Further, the short-circuit bar 16 is a second short-circuit bar 16 in which a bent portion 16R is provided in a round bar on a first short-circuit bar 16a having a flat plate shape.
Are formed by combining the short-circuit bar 16b of the second short-circuit bar 16b with the through-hole 15b of the current transformer 15.
6R, it is easy to assemble, and as shown in FIG. 4, the height H3 of the short-circuit bar 16 can be reduced, so that the height of the electronic wattmeter can be reduced.

[0015]

According to the electronic wattmeter of the present invention, the current transformer in which the axial direction of the through-hole through which the short-circuit bar penetrates as the primary coil is arranged in a direction perpendicular to the bottom surface of the base. , The height of the electronic wattmeter can be reduced, and even if the size of the current transformer changes, wiring can be done simply by changing the shape of the short-circuit bar, and the dimension between terminals can be reduced. There is no need to change, and standardization of the terminal-to-terminal dimensions is possible.

Further, according to the electronic watt-hour meter of the present invention, one end face of the current transformer orthogonal to the axial direction of the through hole is supported by the first projection protruding from the end face of the base. Since the other end surface of the current transformer is supported by the second protrusion protruding from the carrier disposed on the other end surface side, the current transformer does not contact the conductive portion, and the secondary coil of the current transformer is And the insulation between the conductive parts is improved.

Further, according to the electronic watt-hour meter of the present invention, the short-circuit bar is formed of a bar having a bent portion penetrating through the through hole of the current transformer on the first flat short-circuit bar. Because the second short-circuit bar is connected, the through-hole of the current transformer can be easily assembled by passing the bent portion of the second short-circuit bar, and the height of the electronic watt-hour meter can be reduced. Can be lower.

[Brief description of the drawings]

FIG. 1 is a front view showing the inside of a three-phase four-wire electronic watt-hour meter according to an embodiment of the present invention, with a cover cut away.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a sectional view taken along line III-III in FIG. 1;

FIG. 4 is a side view showing how to integrate a current transformer into the short-circuit bar according to the first embodiment of the present invention.

FIG. 5 is a plan view showing a structure of a current transformer mounting portion of a conventional single-phase two-wire electronic watt-hour meter.

FIG. 6 is a sectional view taken along line VI-VI in FIG.

FIG. 7 is an exploded perspective view of FIG.

[Explanation of symbols]

10 base, 10a bottom surface, 10d first protrusion, 1
1 cover, 12 terminal block, 13 power supply side terminal, 14
Load-side terminal, 15 current transformer, 15b through hole, 16 short-circuit bar, 16a first short-circuit bar, 16b second short-circuit bar, 16R bent portion, 20 substrate case (carrier),
20a Second protrusion

Claims (3)

[Claims] 1. An insulative housing comprising a base and a cover, a terminal block mounted inside the insulative housing, a power supply side terminal and a load side terminal mounted on the terminal block and connected to external wiring, A short-circuit bar connected between the side terminal and the load-side terminal, and the short-circuit bar has a through-hole penetrating as a primary coil, and the axial direction of the through-hole is orthogonal to the bottom surface of the base. A current transformer arranged in the direction and detecting a current proportional to the current flowing through the primary coil. A first projection projecting from an end face of the base and supporting one end face of the current transformer orthogonal to an axial direction of the through hole; and a carrier disposed on the other end face side of the current transformer. 2. An electronic watt-hour meter according to claim 1, further comprising a second projection projecting from the carrier and supporting the other end surface of the current transformer. 3. The short-circuit bar is formed of a first flat-plate short-circuit bar and a bar connected to the first short-circuit bar and having a bent portion penetrating a through hole of the current transformer. 3. A short-circuit bar as claimed in claim 1 or claim 2.
Electronic watt-hour meter as described.