JPH07218553A - Printed circuit board - Google Patents

Abstract

PURPOSE:To provide a printed circuit board of uniform quality, which can be assembled easily and whose contour is designed small. CONSTITUTION:Grooves 2a, 2b are parallel provided at the right side face of a printed circuit board 2. A coil-form primary conductor 5 is inserted in these grooves 2a, 2b, and the end face of the coiled portion of this primary conductor 5 is contacted with the bottom surface of the groove 2a. A magneto-electric transducing element 3 is installed in advance in the center of that part of printed circuit board 2 which is pinched by the grooves 2a, 2b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring instrument such as a voltmeter or an ammeter using a magnetoelectric conversion element, and more particularly to a print provided with a magnetoelectric conversion element and a coil for applying a magnetic field to the magnetoelectric conversion element. Regarding the substrate.

[0002]

2. Description of the Related Art A front view of a printed circuit board and a terminal block of an ammeter incorporated in a conventional ammeter for detecting a current by a magnetoelectric conversion element is shown in FIG. 9 (a), and the right part of FIG. 9 (a) is shown. A plan view is shown in FIG.

In FIGS. 9 (a) and 9 (b), a printed circuit board 2C is attached to the front surface of the housing 1 not shown in detail with fixing screws 11, and a pair of terminal blocks 4 are provided at the lower end of the housing 1. It is attached with machine screws 11A.

Of these, the magnetoelectric conversion element 3 has its lead wire in the lower central portion of the printed circuit board 2C.
It is attached in a state of being soldered to the pattern C. Similarly, a primary conducting wire 5C formed in a coil shape is placed in the lower central portion of the printed circuit board 2C, and the lead wires 5x and 5y of the primary conducting wire 5C are terminals 1S and 1L provided on the terminal block 4. Respectively connected to. Of these terminals 1S and 1L, the terminal 1S is connected to the power source side,
The terminal 1L is connected to the load side.

The primary conductor wire 5C is wound in advance so that only the central portion has a wide interval, and the lead wire of the magnetoelectric conversion element 3 is mounted between the conductor wires having the wide interval with a predetermined gap. Has been.

Next, FIG. 10 is a perspective view showing an example of a conventional printed circuit board in which a core is used as a magnetizing means of a magnetoelectric conversion element. In FIG. 10, an annular core 6A made of ferrite is placed at the center of the right end of the printed circuit board 2D, and this core 6A is a pair of bundled band.
It is fixed to the printed circuit board 2D at 12. Further, the primary conductor 9 penetrates through the core 6A, and both ends of the primary conductor 9 have terminals 1S, 1 (not shown) provided on the terminal block 4B.
It is connected to L.

In the core 6A, a groove 3a is previously formed in the center portion on the left end in FIG. 10, and the magnetoelectric conversion element 3 is previously soldered to the through hole of the printed board 2D in the center portion of the groove 3a.

[0008]

[Problems to be Solved by the Invention]
In the printed circuit board shown in FIG. 9, since the center of the primary conductor 5C is widened, this clearance may increase the leakage of the magnetic flux that magnetizes the magnetoelectric conversion element. Also, when attaching the primary conducting wire 5C, it is confirmed that the lead wire of the magnetoelectric conversion element 3 is located in the middle part of the central clearance, but this magnetoelectric converting element 3 is blocked at the front side portion of the primary conductor wire 5C. Since it is difficult to see, it may not only take a long time to confirm, but also the mounting accuracy may deteriorate (Note; in FIG. 9A, the magnetoelectric conversion element 3 is shown between the conductors on the front side of the primary conductor 5C. However, it is actually located between the conductors on the rear side of the primary conductor 5C).

Furthermore, for large currents, the primary conductor 5C
Since the outer diameter of the printed circuit board becomes larger (about 3 cm), the height from the mounting surface of the printed circuit board 2C becomes higher than other resistors and capacitors mounted on the printed circuit board 2C.
As a result, there is a drawback that the outer shape of the ammeter increases.

Therefore, a method of increasing the clearance formed in the center of the primary conducting wire 5C can be considered, but then not only the leakage magnetic flux further increases but also the outer shape of the printed circuit board 2C increases. Further, if the lead wire of the magnetoelectric conversion element 3 is not located in the center of the clearance formed in the center of the primary conductor wire 5C, the withstand voltage value between them is lowered and the insulation is broken, and the detection circuit is also damaged. The main circuit voltage may be applied.

On the other hand, also in the printed circuit board shown in FIG. 10, the magnetoelectric conversion element 3 is provided in the center of the groove 3a of the annular core 6A.
When fixing with the bundling band 12 so that
Careful attention is required so that the groove 6a of the core 6A is not displaced, and it takes time.

That is, when the bundle band 12 is tightened, the core 6A may be displaced or slightly rotated, so that re-tightening must be repeated many times, which takes time and results in variation in quality. There is a fear. Therefore, although the position of the groove 3a is fixed by using a jig, it takes time to attach and detach the jig. Therefore,
An object of the present invention is to obtain a printed circuit board which has a small outer shape, is easy to assemble, and can prevent quality variations.

[0013]

According to a first aspect of the present invention, there is provided a coil-shaped primary conductor to which a measurement current is applied and a magnetoelectric conversion element through which a magnetic flux generated by the measurement current applied to the primary conductor penetrates. In a printed circuit board provided with, at least a pair of grooves, one side of which is opened, is formed in the printed circuit board, a primary conductor is inserted into the pair of grooves, and the magnetoelectric conversion element is inserted in the center of the printed circuit board sandwiched by the pair of grooves. Is fixed.

Further, the invention according to claim 2 is provided with a magnetic field applying core in which the primary conducting wire through which the measuring current is passed passes through the through hole, and a magnetoelectric conversion element between the groove formed in the magnetic field applying core. In the printed circuit board, a U-shaped recess is formed in the printed circuit board, and a core fixture having a magnetic field applying core is inserted in the recess, and a magnetic field is applied to the center of the bottom of the recess of the printed circuit board. It is characterized in that the conversion element is fixed.

[0015]

According to the first aspect of the invention, the position of the primary conductor attached to the printed circuit board is determined by the groove formed in the printed circuit board and the bottom of this groove.
Further, in the invention described in claim 2, the position and direction of the magnetic field applying core attached to the printed circuit board are determined by an end portion of the core fixture into which the magnetic field applying core is inserted and a concave portion formed on the printed circuit board. Positioned by the bottom.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing an embodiment of a printed circuit board according to the present invention, wherein (a) is a front view and (b) is a right side view of (a). It is a figure corresponding to FIG. 9 shown by.

In FIG. 1, grooves 2a and 2b parallel to each other are horizontally formed on the lower right side of the printed circuit board 2. The primary conductors 5 wound at equal intervals are loosely fitted in the grooves 2a, 2b from the right side, and the lead wire 5a on one side of the primary conductor 5 is connected to the terminal 1S of the terminal block 4 and the leads on the other side are connected. The line 5b is connected to the terminal 1L.

On the other hand, the magnetoelectric conversion element 3 is previously attached to the central portion of the substrate sandwiched by the upper and lower grooves 2a and 2b. On the printed circuit board 2, a capacitor, a resistor and the like (not shown) are attached to the left side and the upper side of the primary conductor 5 in the same manner as in the conventional case.

In the printed board thus constructed, the magnetoelectric conversion element 3 is first attached to the printed board 2 together with other resistors and the like, and after soldering, the primary conducting wire 5 is inserted from the right side. By making the left end of the coil portion of the primary conductor 5 lightly contact the bottom of the groove 2a, the primary conductor 5
The mounting position can be determined by the upper and lower grooves 2a and 2b and the bottom of the upper groove 2a.

Therefore, unlike the conventional printed circuit board, the work of assembling the magnetoelectric conversion element 3 from the narrow gap formed in the central portion of the primary conducting wire 5C is not required, so that not only the assembly is facilitated but also the primary conducting wire is provided. Since it is not necessary to form a clearance in the middle part of 5, the outer shape can be made smaller, the leakage magnetic flux can be reduced, and the detection accuracy of the ammeter can be improved.

Next, FIG. 2 is a front view showing another embodiment of the printed circuit board according to the present invention, which corresponds to FIG. 1 (a). In FIG. 2, printed circuit board 2A
A pair of grooves 2C are formed vertically symmetrically in the lower part of the left and right, and the primary conductors 5A and 5B are loosely fitted in the left and right grooves 2C from below. On the other hand, the magnetoelectric conversion element 3 is previously attached to the central portion of the substrate sandwiched by the grooves 2c.

Of these, the lead wire of the left primary conductor 5A is connected to the terminals 1S and 1L provided on the terminal block 4A, and the lead wire of the right primary conductor 5B is the terminals 3S and 3L.
The terminals 1S and 1L are connected between the three-phase power supply and the first phase of the three-phase load, and the terminals 3S and 3L are connected between the three-phase power supply and the third phase of the three-phase load.

Also in the printed circuit board thus configured, the current supplied to the three-phase load is detected by increasing the height of the casing 1A by separating the distance between the terminal block 4A and the lower end of the printed circuit board 2A. It can be applied to a printed circuit board that detects a current component of an electric power meter.

Next, FIG. 3 is a partial front view showing an embodiment of the printed circuit board according to the present invention, which corresponds to FIG. 10 shown in the prior art, and FIG. 5 shows FIG. It is a partial rear view. In FIG. 3, the core 6 has a substantially square outer shape, and a groove 6a is formed on one side as shown in FIG. 4 showing a state before assembly. On the other hand, printed circuit board 2
At the center of the lower end of B, a recess 2a is formed as shown in FIG.

The core 6 is fixed to the printed circuit board 2B in a state of being inserted into a core fixing tool 8 which is previously molded of ABS resin. That is, the core fixture 8 is formed with a U-shaped recess 8e in FIG.

Grooves 8a are formed symmetrically on the left and right of the recess 8e, and the width between the bottoms of the grooves 8a is slightly wider than the width of the core 6. A groove 8d shown by a broken line in FIG. 4 is also formed on the bottom of the recess 8e. Grooves 8c are formed symmetrically on the outer surfaces of both sides of the core fixing tool 8 as shown in FIG. 5, and the width of the groove 8c in the front-back direction of the drawing in FIG. 5 is the thickness of the printed board 2B. Is slightly wider than.

Further, on both sides of the rear end of the core fixing tool 8,
Arrow-shaped claws 8b whose tips protrude inward are symmetrically projected, and triangular protrusions are formed symmetrically inside the tips of these claws 8b.

In the printed board thus constructed, the core 6 is first fixed to the core fixture 8 through the grooves 8a and 8b before being inserted into the printed board 2B. When the core 6 is inserted up to the groove 8d, the rear end surface is gripped by the convex portion due to the elastic return of the claw 8b that was opened at the time of insertion.

In the printed board thus constructed, the core fixture 8 having the core 6 inserted therein is inserted into the recess 2a with the groove 8c fitted to both sides of the front end of the recess 2a of the printed board 2. Insert. Then, the core fixture 8
The inside of the rear end of the groove 8c comes into contact with the bottom of the recess 2a and is positioned. Therefore, the magnetoelectric conversion element 3 previously attached to the printed circuit board 2 has the groove 6 a of the core 6.
Since it can be located at the center of the board, no adjustment is required, and the attention and skill of the operator are not required, it is possible to obtain a printed circuit board with easy assembly and constant quality.

Next, FIG. 6 shows a case where two cores and a magnetoelectric conversion element are attached to the printed circuit board 2B and the present invention is applied to a printed circuit board for detecting a current component of a three-phase load.
In FIG. 6, a pair of recesses 2a is formed on the printed circuit board 2C as shown in FIG. 7 (a) showing a partial front view of FIG. 4, and a magnetic field is provided at a position facing the center of the bottom of each recess 2a. The conversion element 3 is fixed to the printed circuit board 2C.

As shown in FIGS. 4 and 5, a core fixing tool 8 having a core 6 inserted therein is inserted into each recess 2a. In FIG. 4, the core 6 on the left side is
The primary conductor 9A penetrates, and the core 6 on the right side has the primary conductor 9
B penetrates, of which both ends of the primary conductor 9A are connected to terminals 1S and 1L of the terminal block 4B, and both ends of the primary conductor 9B are connected to terminals 3S and 3L. Note that FIG.
(B) shows the AA sectional view of FIG. Also, reference numeral 12
Shows nails for fixing the printed circuit board 2C to the housing 1A.

Next, FIG. 8 is a partial front view showing another embodiment of the printed circuit board according to the second aspect of the present invention and corresponds to FIG. In FIG. 8, a fixed leg 6b is projectingly provided on the rear end of the annular core 6B as shown in FIG. 8 (b). On the other hand, a protrusion is formed at the center of one end of the core fixture 8A, and the foot 6 is provided at the center of the protrusion.
A through hole into which b is loosely fitted is formed.

In this way, the core 6B and the core fixture 8A
Also in the printed circuit board on which the core is formed, the core 6B is
By inserting the foot 6b of the core 6B into the convex portion of the core fixture 8A, the core 6B with respect to the printed circuit board 2B is inserted.
Since the position and the direction of can be regulated, it is possible to easily assemble, and it is possible to obtain a printed board having no variation in quality and characteristics.

[0034]

As described above, according to the invention of claim 1,
In a printed circuit board provided with a coil-shaped primary conductor to which a measurement current is applied and a magnetoelectric conversion element through which a magnetic flux generated by the measurement current supplied to the primary conductor penetrates, at least one pair of openings on one side of the printed circuit board Forming a groove,
By inserting the primary conductor wire into the pair of grooves and fixing the magnetoelectric conversion element to the central portion of the printed board sandwiched by the pair of grooves, the position of the primary conductor wire attached to the printed board is
Since the positioning is performed by the groove formed on the printed board and the bottom of the groove, it is possible to obtain a printed board which has a small outer shape, is easy to assemble, and can prevent quality variations.

According to the second aspect of the present invention, the primary conducting wire through which the measuring current is passed is provided between the magnetic field applying core penetrating the through hole and the groove formed in the magnetic field applying core. In a printed circuit board provided with a magnetoelectric conversion element, a U-shaped recess is formed in this printed circuit board, and a core fixing tool having a magnetic field applying core inserted therein is inserted into this recess, and the bottom of the recess of the printed circuit board is attached. By fixing the magnetoelectric conversion element in the central part, the position and direction of the magnetic field applying core attached to the printed circuit board can be determined by determining the position and direction of the magnetic field applying core, the end of the core fixing tool into which the magnetic field applying core is inserted, and the recess formed in the printed circuit board. Since the positioning is performed by the bottom portion of the printed circuit board, it is possible to obtain a printed circuit board having a small outer shape, easy assembling, and preventing variations in quality.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a printed circuit board according to the first aspect of the present invention.

FIG. 2 is a front view showing another embodiment of the printed circuit board according to the first aspect of the present invention.

FIG. 3 is a partial front view showing an embodiment of the printed circuit board according to the second aspect of the present invention.

FIG. 4 is a partial front view showing the operation of the printed circuit board according to the second aspect of the invention.

FIG. 5 is a rear view showing a main part of the printed circuit board according to the second aspect of the invention.

FIG. 6 is a front view showing another embodiment of the printed circuit board according to the present invention.

FIG. 7A is a partial front view showing another embodiment of the printed circuit board according to the present invention. (B) is A of FIG.
-A sectional view.

FIG. 8A is a partial front view showing the operation of another embodiment of the printed circuit board according to the present invention. (B) is
The front view which shows the principal part of (a).

FIG. 9A is a front view showing an example of a conventional printed circuit board. (B) is a partial right side view of (a).

FIG. 10 is a perspective view showing an example of a conventional printed circuit board different from FIG.

[Explanation of symbols]

1, 1A, 1B ... Casing, 2, 2A, 2B, 2C ... Printed circuit board, 3 ... Magnetoelectric conversion element, 4, 4A ... Terminal block, 5, 5
A, 5B ... Primary conductor wire, 6, 6A, 6B ... Core, 8 ... Core fixture, 9, 9A, 9B ... Primary conductor wire.

Claims (2)

[Claims] 1. A printed circuit board comprising a coil-shaped primary conductor to which a measurement current is applied and a magnetoelectric conversion element through which a magnetic flux generated by the measurement current applied to the primary conductor penetrates. Is formed, at least a pair of grooves are formed, the primary conductor is inserted into the pair of grooves, and the magnetoelectric conversion element is fixed to the central portion of the printed board sandwiched between the pair of grooves. Printed board. 2. A printed circuit board comprising a magnetic field applying core, through which a primary conductor to which a measuring current is applied passes through a through hole, and a magnetoelectric conversion element between grooves formed in the magnetic field applying core. A U-shaped recess was formed, and a core fixture having the magnetic field applying core was inserted into the recess, and the magnetoelectric conversion element was fixed to the center of the bottom of the recess of the printed circuit board. A printed circuit board characterized by the above.