JP3078687B2 - Electronic watt-hour meter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic watt-hour meter attached to, for example, a front door of a switchboard.

[0002]

2. Description of the Related Art FIG. 2 shows an example of an exploded perspective view of a conventional electronic watt-hour meter. This electronic watt-hour meter has a housing 6 formed of a resin containing glass fiber into a rectangular box shape. The printed circuit boards 1 and 2A housed inside the housing 6 and a transparent front cover whose rear portion is fitted and fixed to the front surface of the housing 6
It is roughly composed of ten.

The frame 6 has a frame-shaped flange portion 6a formed on the outer periphery of the front end thereof, and a guide portion 6c having an arc-shaped front end is vertically provided on the left and right sides of the flange portion 6a. A rectangular projection 6d is formed at the center of the lower end of the flange 6a, and a sealing hole is provided at the center of the projection 6d.

[0004] On the upper and lower surfaces of the housing 6, two grooves 6b are formed parallel to each other in the front-rear direction, and the upper and lower grooves 6b are also formed on the side surface of the housing 6. A convex portion 6e having a U-shaped cross section is formed in the center of the upper and lower inner surfaces of the housing 6 in the front-rear direction, and a female screw hole is provided at a front end of the convex portion 6e. A bottom is formed at the rear end of the housing 6, and a rectangular hole is formed at the center of the bottom. Small screw holes (not shown) are formed at each of the four corners of the bottom.

At four corners of the printed circuit board 2A shown on the left side of the housing 6, small screw holes 2c are provided.
Terminal blocks 15 are provided vertically on the left and right sides of the back of A.
The 15 pins penetrate through holes in the printed circuit board 2A and are soldered. Terminal screws to which connection wires of a switchboard to which the electronic watt-hour meter is attached are connected to the rear surface of each terminal block 15.

At the center of the upper and lower ends of the printed circuit board 2A,
A semicircular guide portion 2b is formed, a transformer or the like is mounted on the surface of the printed board 2A, and the terminals of each transformer are soldered to the pattern of the printed board 2A.
On the front surface of each of the four corners of the printed circuit board 2A,
The rear end of the printed circuit board 2A is abutted, and is fixed to the printed circuit board 2A with a pan-head screw 5 inserted from behind each of the small screw holes 2c at each of the four corners of the printed circuit board 2A.

The back surface of a small screw hole 1a formed at each of the four corners of the printed circuit board 1 abuts on the front surface of each of the columns 3, and is fixed to each of the columns 3 with a pan-head screw 5 inserted from the front of the small screw hole 1a. Have been. On the front surface of the printed circuit board 1, a setting portion 1c is attached from the center to the lower portion, and an electronic circuit board is attached above the setting portion 1c.

A recess 10a is formed at the center of the lower end of the front cover 10 provided on the front side of the printed circuit board 1. A small screw hole penetrating the center of the recess 10a has a sealing screw.
The tip of the sealing screw 11 is screwed into the female screw hole at the front end of the projection 6e formed at the center of the lower end of the housing 6 described above. A U-shaped groove 10 b is formed in the upper part of the left and right ends of the front cover 10, and this groove 10 b is engaged with a convex part formed in the left and right upper part of the housing 6.

At the upper right corner and lower lower corner of the housing 6,
A central bent portion of the mounting bracket 8 bent into a substantially L-shape fits loosely, and a pan screw 9 is inserted into a small screw hole provided in a bent portion 8a at the rear end of the mounting bracket 8 from behind. Has been inserted.

When this electronic watt-hour meter is mounted on a mounting square hole formed in a switchboard door or the like, a pan screw 9 is provided on the back surface of the switchboard door and screwed into a screw hole. The outer periphery of the mounting square hole of the switchboard door is fastened by the front end of the mounting bracket 8 and the flange 6 of the housing 6. When connecting the secondary wire of the instrument current transformer or the secondary wire of the instrument transformer attached to the switchboard, wind the wire end around the terminal screw provided on the rear surface of the terminal block 15. And a Philips screwdriver. The printed circuit boards 1 and 2A are first assembled to each other with the supporting column 3 and the front and rear pan-head screws 5, and then the printed circuit boards 2A are formed on the protrusions 6e formed on the upper and lower sides of the housing 6 from the front of the housing 6.
The upper and lower guide portions 2b are loosely fitted and guided and inserted.
These are inserted from the rear of the housing 6 and the tips are formed above and below the terminal block 15, so that they are fixed to the housing 6 with small pan screws that are screwed into screw holes.

[0011]

However, in the electronic watt-hour meter constructed as described above, the pressing force at the time of tightening with a Phillips screwdriver that tightens the connecting wire from behind the terminal block 15 is used together with the terminal block 15. The printed board 2A may bend and the pattern formed on the printed board 2A may be cut. Further, each of the printed circuit boards 1, 2
A: Since there are many tightening screws for the columns 3 that assemble each other, it takes time to assemble. Therefore, an object of the present invention is to provide an electronic watt-hour meter capable of shortening the assembling time and eliminating the risk of pattern breakage when connecting an external electric wire.

[0012]

According to the present invention, a first printed circuit board is housed in a rear portion of a housing, and a terminal block is mounted on a rear surface of the first printed circuit board. In an electronic watt-hour meter in which a second printed circuit board is accommodated in the front, a rear surface of the first printed circuit board is in contact with a rear surface of the first printed circuit board, and a plurality of legs protruding forward supports the second printed circuit board. A mounting bracket is provided.

[0013]

In order to connect the electric wire to the terminal block from the back of the electronic watt-hour meter, the pressing force applied to the terminal block from the rear is transmitted to the mounting bracket via the terminal block.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of an electronic watt-hour meter of the present invention will be described below with reference to the drawings. FIG. 1A is an exploded perspective view showing an example of an electronic watt-hour meter according to the present invention, which corresponds to FIG. 2 shown in the prior art, and differs from FIG. 1 (b), the rear end of the board mounting bracket 3 is inserted.

1 (a) and 1 (b), the board mounting bracket 3 has legs 3a projecting forward from four corners of a rectangle. The front end of each leg 3a is bent inward, and a small screw hole for fixing the printed circuit board 1 with a small screw 5 is formed in the center of the bent portion.

At the center of the rear part of the board mounting bracket 3, a convex part 3 b projecting rearward is formed. At each of the four corners of the rear part, a pan screw 13 into which the board mounting bracket 3 is inserted from the rear of the housing 6.
, A female screw hole 3d for fixing to the housing 6 is formed. Further inside the female screw holes 3d, female screw holes 3c for fixing the terminal block 4 to the board mounting bracket 3 are formed, respectively.
An oval hole 3e is provided further inside the female screw hole 3c. Notches 2a are provided at each of the four corners of the printed circuit board 2.
Are formed.

In the electronic watt-hour meter configured as described above, the printed circuit board 2, the board mounting bracket 3, and the terminal block 4
The pin protruding from the front surface of the terminal block 4 is soldered to a through hole formed in the printed circuit board 2 so that the printed circuit board 2 and the terminal block 4 hold the board mounting bracket 3.

The pressing force applied to the terminal block 4 by the driver when connecting the connection wire of the switchboard to the terminal portion on the rear surface of the terminal block 4 is high in rigidity with an L-shaped cross section on both sides of the board mounting bracket 3. Applied to the printed circuit board 2
Can be prevented. Further, in the conventional electronic watt-hour meter, four pillars 3 are attached with the total of eight front and rear pan screws 5 in order to attach the printed board 1 to the printed board 2. Since the printed circuit board 1 can be simply tightened with the pan head screw 5 to the front end of the leg 3a of the board mounting bracket 3,
Assembly work becomes easy.

[0019]

As described above, according to the present invention, the first printed circuit board is housed in the rear part of the inside of the housing, and the terminal block is attached to the rear surface of the first printed circuit board. In an electronic watt-hour meter in which a second printed circuit board is accommodated in the front, a rear surface of the first printed circuit board is in contact with a rear surface of the first printed circuit board, and a plurality of legs protruding forward supports the second printed circuit board. By providing the mounting bracket, in order to connect the electric wire to the terminal block from the back of the electronic wattmeter, the pressing force applied to the terminal block from the rear is transmitted to the mounting bracket via the terminal block. As a result, it is possible to obtain an electronic watt-hour meter that can reduce the assembly time and eliminate the possibility of the printed circuit board breaking when connecting an external electric wire.

[Brief description of the drawings]

FIG. 1A is an exploded perspective view showing one embodiment of an electronic watt-hour meter of the present invention. (b) is a partial detailed perspective view of (a).

FIG. 2 is an exploded perspective view showing an example of a conventional electronic watt-hour meter.

[Explanation of symbols]

1, 2 ... printed circuit board, 3 ... board mounting bracket, 4 ... terminal block, 5, 9 ... pan screw, 6 ... housing, 8 ... mounting bracket, 10
... front cover, 11 ... sealing screw.

Claims (1)

(57) [Claims] 1. A first printed circuit board is housed in a rear portion of a housing, a terminal block is attached to a rear surface of the first printed circuit board, and a second printed circuit board is provided in front of the first printed circuit board. In the electronic watt-hour meter, the rear surface of the first printed circuit board is in contact with the rear surface, and a mounting bracket for supporting the second printed circuit board with a plurality of legs protruding forward is provided. An electronic watt-hour meter characterized by the above-mentioned.