JP2001108717A - Electronic wattmeter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize, to moderate restriction required for a size and weight of a current transformer, and to enhance assembling workability. SOLUTION: A packing member 6 is interposed between a side wall 1A of a case part 1 for storing a circuit board and a terminal block 3 fixed removably onto an attaching part 2 projected on an outer face of the side wall 1A to hold the each current transformer 5 in a condition where a tip side of a current terminal 4 penetrated through an opening 1B of the side wall 1A to be projected inside the case part 1 is penetrated through the center hole 5A of the each current transformer 5, and the each current transformer 5 is sandwiched between the packing member 6 and the terminal block 3.

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 provided with a current transformer for detecting a current amount, and more particularly, to an electronic watt-hour meter having a structure in which the current transformer is arranged outside a case. It is about.

[0002]

2. Description of the Related Art As an electronic watt-hour meter for measuring the power consumption of a consumer, an electronic watt-hour meter shown in FIG. In this electronic watt-hour meter, a mounting portion C is projected from an outer surface of a side wall B1 of a case portion B for housing a circuit board A and the like, and a terminal block D is detachably screwed to the mounting portion C. ing. The case portion B and the mounting portion C constitute a base. And, in this terminal block D,
The base ends of the plurality of current terminals E to which the external lead-in wires are connected are fixed, and the front ends of the respective current terminals E are connected to the primary conductor F and the like arranged in the case portion B. It penetrates the side wall B1 and protrudes into the case portion B.

In the electronic wattmeter shown in FIG. 3, a pair of current transformers G for detecting the amount of current passing through the primary conductor F is soldered to a circuit board A via lead pins G1. Have been. This current transformer G has a center hole G2 through which the primary conductor F passes.

Further, as shown in FIG. 4A, a conventional example in which the current transformer G is fixed to a mounting block H which is screwed to the bottom surface of a case B, or as shown in FIG. A conventional example in which a current transformer G is penetrated and fixed to a primary conductor F, and a conventional example in which a current transformer G is penetrated and fixed to a current terminal E inside a side wall B1 as shown in FIG. Is also known.

[0005]

In the conventional example of FIG. 3 in which the current transformer G is soldered to the circuit board A, the size of the current transformer G that can be soldered to the circuit board A is limited due to the structure of the circuit board A. There were restrictions on weight and weight. Further, in the assembling work inside the case portion B, the primary conductor F is inserted into the center hole G2 of the current transformer G soldered to the circuit board A, and the circuit board A is screwed into the case portion B. Then, it is necessary to position both ends of the primary conductor F at the distal end of the current terminal E and screw them in a narrow working space between the circuit board A and the side wall B1, and the assembling work is extremely time-consuming. It was a tedious task. Also, both ends of the primary conductor F are connected to the current terminals E.
In addition, a space for screwing is required, and the current transformer G projects below the circuit board A, which hinders miniaturization of the wattmeter.

In the conventional example shown in FIG. 4A, a current transformer mounting member called a mounting block H is newly required, and any one of FIGS. 4A, 4B and 4C is required. The structure also requires a capacity for accommodating the current transformer G in the case portion B.

Therefore, the present invention can reduce the size of the watt-hour meter, and can reduce the size and weight restrictions of the current transformer.
Moreover, an object of the present invention is to provide an electronic watt-hour meter capable of improving the assembling workability.

[0008]

In order to solve the above-mentioned problems, an electronic wattmeter according to the present invention comprises a case for accommodating a circuit board and a mounting portion projecting from an outer surface of a side wall of the case. And a terminal block detachably fixed to the mounting portion of the base, and a base end portion fixed to the terminal block, and a distal end portion protruding into the case portion through an opening in the side wall. A current terminal, and an electronic watt-hour meter including a current transformer that detects an amount of current passing through the current terminal, wherein between the side wall and the terminal block,
A packing member for holding the current transformer is provided in a state where the front end side of the current terminal passes through the center hole of the current transformer, and the current transformer is sandwiched between the packing member and the terminal block. And

Further, the packing member has a flange abutting on an outer surface of the side wall, a holding hole for fitting and holding the current transformer, and a terminal insertion hole for inserting the current terminal. And

In the electronic watt-hour meter of the present invention, the current transformer is arranged in a small gap of the mounting portion outside the case portion, so that the watt-hour meter can be reduced in size. Further, since the current transformer is sandwiched between the packing member and the terminal block on the mounting portion, restrictions on the size and weight of the current transformer are eased as compared with the case where the current transformer is soldered to the circuit board. .

On the other hand, in the assembling operation, the current transformer is held by the packing member outside the case portion, and the leading end side of the current terminal projecting from the terminal block is passed through the center hole of the current transformer using the hole as a guide. It is sufficient if the current transformer is sandwiched between the packing member and the terminal block, and the packing member is brought into contact with the side wall of the case to fix the terminal block to the mounting base.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an electronic watt-hour meter according to the present invention will be described with reference to the drawings. In the referenced drawings,
FIG. 1 is an exploded perspective view showing a main part structure of an electronic wattmeter according to one embodiment of the present invention, and FIG. 2 is an exploded perspective view showing a fixing means of a terminal block of the electronic wattmeter according to one embodiment. It is.

As shown in FIG. 1, an electronic watt-hour meter according to one embodiment includes a case portion 1 for accommodating a circuit board (not shown) and a mounting portion 2 protruding from an outer surface of a side wall 1A of the case portion 1. A base, a terminal block 3 detachably fixed to the mounting portion 2, a base end fixed to the terminal block 3, and a distal end formed in the opening 1B of the side wall 1A.
And current terminals 4 protruding into the case portion 1 through the first and second terminals 1 and 2 for detecting the amount of current passing through the current terminals 4.
And a pair of current transformers 5 and 5. And the case part 1
A packing member 6 for holding each current transformer 5 is provided between the side wall 1A and the terminal block 3 so that the front end side of the current terminal 4 passes through the center hole 5A of each current transformer 5. Each current transformer 5 is sandwiched between the packing member 6 and the terminal block 3.

The case portion 1 is formed in a substantially rectangular box shape, and has pillars 1C and 1D for screwing a circuit board (not shown) projecting from the inner bottom surface thereof. The mounting portion 2 is formed in a U-shaped cross section having substantially the same width as the side wall 1A of the case portion 1. As shown in FIG. 2, insertion holes 2A for set screws 7 for detachably fixing the terminal block 3 are formed in the left and right bottom portions of the mounting portion 2. Then, the case portion 1 and the mounting portion 2
Are integrally formed by die molding.

As shown in FIG. 2, the terminal block 3 has a substantially rectangular parallelepiped fitted inside the mounting portion 2, and is molded by a suitable synthetic resin. At the left and right bottom surfaces of the terminal block 3, insertion holes (not shown) are formed which match the insertion holes 2A of the mounting portion 2, and the set screws 7 are screwed into the left and right side walls 3A. The insertion slot 3B of the screw receiving piece 8 provided with the female screw 8A is formed.

The terminal block 3 has left and right side walls 3.
A, 3A is provided with a rear wall 3C, and a pair of partition walls 3D, 3D are provided in a recess surrounded by the rear wall 3C and the left and right side walls 3A, 3A in parallel with the left and right side walls 3A, 3A. And 1
A pair of partition walls 3E, 3E protrude. The pair of partition walls 3D, 3D are provided at the same height as the left and right side walls 3A, 3A and protrude near the center of the terminal block 3 in the left-right direction.
Further, the pair of partition walls 3E, 3E is a pair of partition walls 3D,
The side walls 3A, 3A and the partition wall 3D are about half the height of 3D,
It protrudes between 3D.

Further, in the terminal block 3, a front partition wall 3F parallel to the rear wall 3C is arranged between the side walls 3A, 3E, 3D, 3D, 3E and 3A. Each is protruding. As shown in FIG. 1, a slot-shaped wall opening 3G through which the distal end of the current terminal 4 is inserted is formed in the rear wall 3C of the terminal block 3 and is continuous with the outside of each wall opening 3G. A wall groove 3H is formed. These wall opening 3G and wall groove 3
H is formed at a position facing each front partition wall 3F.

As shown in FIG. 1, the current terminal 4 is formed in an L-shaped planar shape having an engaging portion 4A protruding in the width direction at a base end portion. At the base end of the current terminal 4, an insertion hole 4B for a set screw for connecting a lead-in electric wire (not shown) outside the electronic wattmeter is formed. Also,
At the tip of the current terminal 4, a set screw insertion hole 4 </ b> C for connecting a primary conductor or the like (not shown) arranged inside the case 1 is formed. And this current terminal 4
The distal end side is inserted into the wall opening 3G of the terminal block 3, the base end side is locked to the front partition wall 3F of the terminal block 3, and the spacer block 9 fitted into the wall groove 3H of the terminal block 3 forms an intermediate portion. Are held between the terminal block 3 and the terminal block 3.

The current transformer 5 has a ring shape having a center hole 5A through which the tip end of the current terminal 4 can be inserted, and a projection 5B used for positioning is formed on the peripheral surface thereof. The thickness of the current transformer 5 is set smaller than the protruding length of the current terminal 4 on the distal end side so that the insertion hole 4C at the distal end of the current terminal 4 faces the inside of the case portion 1.

The packing member 6 is made of an insulating rubber or resin material. This packing member 6 includes
Flange 6 abutting on the outer surface of side wall 1A of case 1
A, a holding hole 6B for fitting and holding the pair of right and left current transformers 5 and a terminal insertion for inserting the front end side of each current terminal 4 disposed between and on both sides of the left and right current transformers 5. A hole 6C is formed.

The electronic watt-hour meter according to one embodiment of the present invention can be easily assembled by an assembling operation outside the case 1 and an assembling operation inside the case 1 as described below. That is, as shown in FIG. 1, outside the case portion 1, the pair of current transformers 5 are fitted and held in the left and right holding holes 6 </ b> B of the packing member 6, respectively. Then, the distal end side of each current terminal 4 protruding from the rear wall 3C of the terminal block 3 is inserted into the center hole 5A of each current transformer 5 and each terminal insertion hole 6C of the packing member 6 using these holes as guides. The current transformer 5 is sandwiched between the packing member 6 and the terminal block 3. Then, the terminal block 3 is screwed and fixed to the mounting portion 2 in a state where the flange 6A of the packing member 6 is in contact with the outer surface of the side wall 1A of the case portion 1 so as to maintain the sandwiched state. That is, the insertion hole 2 formed in the mounting portion 2
A set screw 7 is inserted into A, and this is screwed into the female screw 8A of the screw receiving piece 8 inserted into the insertion slot 3B of the terminal block 3.

On the other hand, in the case portion 1, the side wall 1A
A set screw is inserted into an insertion hole 4C at the end of each of the current terminals 4 protruding into the case 1 from the opening 1B of the primary conductor to screw the primary conductor or the like. Also, a circuit board (not shown) is screwed to the columns 1C and 1D of the case 1. In this case, since the complicated routing of the primary conductor is unnecessary, the operation can be easily performed. Also, the assembly and disassembly properties are extremely good. In addition, since the terminal block 3, the current terminal 4, the current transformer 5, and the packing member 6 can be handled as one terminal block assembly during the manufacturing process, the number of parts to be handled at the time of final assembly of the watt hour meter is reduced, and manufacturing control is reduced. Be improved.

As described above, in the electronic watt-hour meter according to one embodiment in which the current transformers 5 and the like are assembled, the pair of current transformers 5 is arranged in a slight gap of the mounting portion 2 outside the case portion 1. ,
Its size can be reduced. Further, since the current transformer 5 is sandwiched between the packing member 6 and the terminal block 3 on the mounting portion 2, its size and weight can be increased as compared with the conventional case where it is soldered to a circuit board. , Restrictions on the size and weight of the current transformer 5 can be reduced. Further, the packing member 6 holding the current transformer 5 functions as a cushioning material that absorbs mechanical stress such as vibration and impact acting on the current transformer 5, so that the large current transformer 5 can be equipped. Become.

[0024]

As described above, according to the electronic watt-hour meter of the present invention, since the current transformer is arranged in a small gap of the mounting portion outside the case portion, the size of the watt-hour meter can be reduced. It becomes possible. Also, since the current transformer is sandwiched between the packing member and the terminal block on the mounting portion, the size and weight can be increased as compared with the case where the current transformer is soldered to the circuit board, and the size of the current transformer is increased. Weight and weight constraints can be relaxed. Further, the packing member holding the current transformer functions as a cushioning material for absorbing mechanical stress such as vibration and impact acting on the current transformer, so that a large current transformer can be provided.

On the other hand, in the assembling operation, the current transformer is held by the packing member outside the case portion, and the leading end side of the current terminal projecting from the terminal block is passed through the center hole of the current transformer using the hole as a guide. It is sufficient to clamp the current transformer between the packing member and the terminal block, abut the packing member on the side wall of the case part, and fix the terminal block to the mounting base. Workability can be improved.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a main structure of an electronic watt-hour meter according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a fixing means of a terminal block of the electronic watt-hour meter according to one embodiment.

FIG. 3 is an exploded perspective view of an electronic watt-hour meter according to a conventional example.

FIG. 4 is a plan view of the inside of a case of an electronic watt-hour meter according to another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Case part 1A ... Side wall 1B ... Opening 1C, 1D ... Column 2 ... Mounting part 2A ... Insertion hole 3 ... Terminal block 3A ... Side wall 3B ... Insertion slot 3C ... Rear wall 3D, 3E ... Partition wall 3F ... Front partition wall 3G ... wall opening 3H ... wall groove 4 ... current terminal 4A ... engaging part 4B, 4C ... insertion hole 5 ... current transformer 5A ... center hole 6 ... packing member 6A ... flange 6B ... holding hole 6C ... terminal insertion hole 7 ... Set screw 8: Screw receiving piece 8A: Female screw 9: Spacer block

Claims (2)

[Claims] 1. A base comprising a case for accommodating a circuit board, a mounting portion projecting from an outer surface of a side wall of the case, a terminal block detachably fixed to the mounting portion of the base, and the terminal block. A current terminal protruding into the case portion with a distal end portion being fixed and having a distal end portion penetrating through the opening of the side wall, and a current transformer for detecting an amount of current passing through the current terminal. An electronic watt-hour meter, wherein a packing member is provided between the side wall and the terminal block, the packing member holding the current transformer such that a front end of the current terminal passes through a center hole of the current transformer. An electronic watt-hour meter, wherein the current transformer is sandwiched between the packing member and the terminal block. 2. The electronic watt-hour meter according to claim 1, wherein the packing member has a flange that contacts an outer surface of the side wall, a holding hole that fits and holds the current transformer. An electronic watt-hour meter having a terminal insertion hole through which the current terminal is inserted.