JP2003161744A - Clamp sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a clamp sensor which is bonded and fixed firmly to the core holder side so that a magnetic core is not moved after an injection resin material has been filled. <P>SOLUTION: The clamp sensor is composed of a sensor 11 on one side and a sensor on another side which have been divided into two parts. The sensor 11 on the one side is constituted of at least the magnetic core 12 composed of a core piece 14 on one side and a core piece 17 on the other side to be butted in a nearly U shape, a magnetoelectric device 20 which is interposed and arranged between butting parts 13 of the magnetic core 12, the core holder 22 in which the magnetic core 12 equipped with the magnetoelectric device 20 is fixed, a shielding case in which the core holder 22 is housed and the injection resin material which fixes these constituent members integrally. In the core holder 22, slopes 25a in which one or more gaps used to reduce their gap width gradually can be formed toward the direction of the inner part between itself and the fixed magnetic core 12 are provided at their inside faces 25, pressure welding pieces 32 corresponding to the slopes 25a are press-fitted to the gap parts, and the magnetic core 12 is positioned and fixed. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for a clamp sensor which can securely and firmly position and fix a magnetic core in a core holder.

[0002]

2. Description of the Related Art A clamp type ammeter is formed with a clamp sensor formed so as to be able to clamp a conductor to be measured in a live state. FIG. 4 is a vertical cross-sectional view showing an example of a conventional clamp sensor, in which the upper sensor portion 9 is made to have a substantially rectangular shape when closed by allowing the upper sensor portion 9 to face open and close freely. Clamp sensor 1 divided into two to enable the formation of a magnetic circuit
Is formed entirely.

In this case, the lower sensor section 2 has a magnetic core 3 having one side core section 3a and the other side core section 3b, each of which has a substantially L shape and is abutted in a substantially U shape, and one side. The Hall element 4 interposed between the abutting portions of the core portion 3a and the other side core portion 3b, the core holder 5 in which the magnetic core 3 having the Hall element 4 interposed therein is placed, and the shield in which the core holder 5 is accommodated. It is formed with the case 7. In addition,
Reference numeral 8 in the figure indicates a coil wound around the magnetic core 3.

The magnetic core 3 is fixed to the core holder 5 by positioning the one side core portion 3a and the other side core portion 3b with the Hall element 4 interposed therebetween through the positioning ribs 6 provided in the core holder 5. However, after being temporarily fixed with an adhesive, the voids of the core holder are filled with an injection resin material such as epoxy resin, and the resin is cured.

[0005]

By the way, the magnetic core 3 can be placed in the core holder 5 with a relatively simple structure by the above method.

However, FIG. 5 (a) is a cross-sectional view of a corner portion located on the left side of the one side core portion 3a in FIG.
As is apparent from FIG. 5B, which is a vertical cross-sectional view in which a portion of the XX line portion in FIG. 5A is omitted, the lateral width of the one-side core portion 3a is set to a, and the core holder 5 When the distance between the positioning ribs 6 and 6 is set to b, processing accuracy and component dimensions vary, resulting in a <b, and gaps t1 and t2 between the positioning rib 6 and the one side core portion 3a. Will be formed. If the gap t1 is, for example, about several hundreds μm, there is a disadvantage that the magnetic core 3 cannot be firmly bonded and fixed to the core holder 5 side even if the injected resin material is filled.

In addition, since the core holder 5 is formed by injecting an insulative molding resin into a molding die and molding the molding die, the draft required for demolding the molded product is the molding die. Pre-assigned to the mold. The presence of this draft causes the magnetic core 3 and the core holder 5 to come into point contact with each other to relatively reduce the contact area. As a result, the magnetic core 3 is firmly bonded and fixed to the core holder 5 side like the gaps t1 and t2. There was also a problem that I could not do it.

Then, the above-mentioned voids t1, t2
When the magnetic core 3 cannot be firmly bonded and fixed to the core holder 5 side due to the above reasons, the finished product is, for example, −10.
When the change in the unbalanced voltage of the Hall element 4 is monitored under a temperature environment of 55 ° C., the magnetic core 3 moves and the change that follows the temperature change is stopped, which adversely affects its characteristics. There was a problem.

In view of the above problems of the prior art, the present invention provides a clamp sensor which can be firmly bonded and fixed to the core holder side so that the magnetic core does not move after being filled with an injection resin material such as epoxy resin. With the goal.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above-mentioned object, and the formation of a magnetic circuit that is face-to-face openable and substantially square when closed is divided into two parts. In the clamp sensor including one side sensor section and the other side sensor section, the one side sensor section is a magnetic core including one side core piece and the other side core piece that are abutted in a substantially U shape. A magnetic-electric conversion element interposed between the abutting portions of the magnetic core, a core holder in which a magnetic core having the magnetic-electric conversion element interposed is fixed, a shield case accommodating the core holder, and these constituent members. At least one of the core holder and the injected resin material is fixed, and the core holder is configured such that when the one side core piece portion and the other side core piece portion are fixed as the magnetic core before the injection resin material is filled, Behind the core The gap width is gradually reduced toward 1
The inner surface is provided with an inclined surface capable of forming the above-mentioned void portion, and the magnetic core is positionally fixed by press-fitting a press-contact piece having a slope corresponding to the inclined surface into the void portion. There are structural features in.

In this case, it is preferable that the voids are separately formed on the inner side surface of the core holder where the one side core piece portion and the other side core piece portion respectively face in the three face directions. It is desirable that the press-contact piece is formed such that the press-fitting stop position is variable in relation to the width of the space.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a book composed of a one-side sensor unit and another-side sensor unit which are freely divided into two parts so as to form a magnetic circuit which is face-to-face openable and close, and which is closed when closed. It is an exploded perspective view showing an arrangement relation between a core holder and a magnetic core which comprise a magnetoelectric conversion element and constitute one side sensor part located under, for example as an example of a clamp sensor concerning the invention.

According to the figure, the clamp sensor which constitutes the clamp type ammeter is similar to the clamp sensor 1 as the conventional example shown in FIG. The other side sensor part not shown located at
It is formed by combining the conductors to be measured in a live state so that they can be opened and closed so that they can be clamped.

In this case, the one-side sensor portion 11 has a magnetic core 12 composed of a one-side core piece portion 14 and an other-side core piece portion 17, which are substantially U-shaped and abutted against each other, and the one-side core piece portion 14. Abutting end face 16a of the other side core abutting end face 19 of the other side core piece portion
2A and 2B, a magnetoelectric conversion element 20 such as a Hall element interposed in the abutting portion 13 of the magnetic core 12 formed by a and a core holder 22 in which the magnetic core 12 with the magnetoelectric conversion element 20 interposed is fixed. The shield case 42 accommodates the core holder 22 as shown in FIG. Although not shown, similar to the clamp sensor 1 shown in FIG. 4, a coil is wound around the magnetic core 12, and an injection resin material such as epoxy resin filled in the void of the core holder 22 is used. By hardening the, the magnetic core 12 is firmly bonded and fixed.

Of these, the one-side core piece portion 1 formed of a high magnetic permeability magnetic material such as permalloy or ferrite.
4 and the other side core piece portion 17 are formed to have a substantially L shape with the vertical side portions 15 and 18 and the horizontal side portions 16 and 19, respectively, and the abutting end surfaces 16a and 19a thereof are butted against each other. As a result, the magnetic core 12 is formed by combining the magnetic cores 12 into a substantially U shape.

On the other hand, the core holder 22 is formed by injecting an insulative molding resin into a molding die and molding it. Specifically, as shown in FIG. 1, the butt end surface 16a is formed. , 19a with a magnetoelectric conversion element 20 interposed between one side core piece portion 14 and the other side core piece portion 17
And are fixed to form an internal structure capable of forming the magnetic core 12.

This will be described in more detail with reference to the illustrated example. The core holder 22 has a bottom surface 43 of the shield case 42.
It is composed of an abutment portion 23 placed on the top and a box portion 24 which is erected integrally on the abutment portion 23 and on which the magnetic core 12 is fixed.

In this case, the box portion 24 has a bottom plate portion 26.
And a side plate portion 27 standing upright around the side plate portion 27. The vertical side portion 15 of the one side core piece portion 14 and the other side core piece are formed on the bottom plate portion 26 surrounded by the side plate portion 27. Part 17
The horizontal side portions 16 and 19 are placed in a state in which the vertical side portions 18 are opposed to each other.

Further, in the box portion 24, the magnetoelectric conversion element 20 is interposed between the lateral side portion 16 of the one side core piece portion 14 and the lateral side portion 19 of the other side core piece portion 17, and then the bottom plate is provided. A support for supporting the positioning rib 29 for fixing the position of the magnetoelectric conversion element 20 and the one-side core piece portion 14 and the other-side core piece portion 17 at a plurality of positions when they are placed on the central portion of the portion 26. Rib 3
0 and are projected.

In this case, the support ribs 30 are provided at the corner portions 14 of the one side core piece portion 14 and the other side core piece portion 17, respectively.
In the example of FIG. 1, two a's and a's can be separately supported from the outside in the left-right direction, a lateral side portion 16 of the one-side core piece portion 14, and a lateral side portion 19 of the other-side core piece portion 17. Two each of which can support both sides in the front-rear direction separately are erected on the inner side surface 25 of the box portion 24.

Moreover, the inner side surface 25 located between the two support ribs 30, 30 supporting the corner portions 14a, 17a of the one side core piece portion 14 and the other side core piece portion 17, respectively, is shown in FIG. As shown in FIG. 2, an inclined surface 25a is formed between the core piece 14 on one side and the core piece 17 on the other side so that a gap 35 whose width gradually decreases in the depth direction can be formed.

The lateral side portion 16 of the one side core piece portion 14 and the other side core piece portion 1 located near the corners 14a, 17a.
The lateral side portion of the one-side core piece portion 14 is also formed on the inner side surface 25 located between the support ribs 30 for separately supporting the lateral side portion 19 of the No. 7 and the inner corner portion 24 a of the box portion 24. 16
Alternatively, an inclined surface 25a is formed between the other side core piece portion 17 and the lateral side portion 19 so that a gap portion 35 can be formed in which the gap width gradually decreases in the depth direction.

Further, the box portion 24 of the core holder 22
The press-contact piece 32, which is press-fitted separately into each void 35 formed between the magnetic core 12 and the magnetic core 12, has a vertical surface portion 3 on one side surface thereof.
3 has a substantially wedge shape, which is formed of, for example, an epoxy resin material, etc., each of which has a slope portion 34 on the other side surface.

In this case, the angle of the inclined surface 25a of the inner side surface 25 of the box portion 24 is θ as shown in FIG. 2 (b).
Then, the angle of the inclined surface portion 34 of the press contact piece 32 is also formed to be the same angle θ.

Since the present invention is constructed in this way, when the magnetic core 12 is fixedly placed in the core holder 22, first, the abutting end face 16a of the lateral side portion 16 of the one side core piece portion 14 and the other side core portion Side part 1 in piece 17
The magnetoelectric conversion element 20 is interposed between the abutting end surface 19a of 9 and the abutting end surface 19a.

Under this condition, the magnetoelectric conversion element 20 is arranged at a predetermined position via the positioning rib 29, and the one side core piece portion 14 and the other side core piece portion 17 are respectively provided with the lateral side portions 16, 19. Is placed on the bottom plate portion 26 of the box portion 24.

In this case, it is formed between the two support ribs 30, 30 for separately supporting the corner portions 14a, 17a of the one side core piece portion 14 and the other side core piece portion 17, respectively. Sloped surface 25a and one vertical core piece portion 14 or the other core piece portion 1 that faces the sloped surface 25a
Since the gap portion 35 is secured between 7 and
The press-contact piece 32 can be press-fitted in the void portion 35 in such a positional relationship that the inclined surface 25a is located on the inclined surface portion 34 side.
The supporting ribs 30, 30 located on the right side in FIG.
Since the support ribs 30 located on the left side are spaced from each other by a distance twice that of the support ribs 30, the two pressure contact pieces 32 are press-fitted.

The lateral side portion 16 of the one side core piece portion 14 and the other side core piece portion 1 located near the corners 14a and 17a.
The inner side surface 25 located between the supporting ribs 30 for individually supporting the lateral side portions 19 of the No. 7 from the front-rear direction and the inner corner portion 24a of the box portion 24 as well as the space 3 between the inclined surface 25a.
Since 5 is secured, the press-contact piece 32 can be similarly press-fitted into each void 35.

Therefore, each of the one-side core piece portion 14 and the other-side core piece portion 17 has a pressure contact piece 32 in each of the three surface directions, as is apparent from FIGS. 2 (a) to 2 (c). It is possible to fix the position in the box portion 24 under the condition that they are in surface contact with each other.

Moreover, the lateral width of the one-side core piece portion 14 (the other-side core piece portion 17) is uneven as shown in FIGS. 3 (a) to 3 (c), that is, 11 to 13 (for example, 11> 12). Even if there is some variation in the gap width of the gap portion 35 due to l3), the position can be fixed while immediately responding to the variation by press-fitting the press contact piece 32 to the stop position.

By thus fixing the magnetic core 12 together with the magnetoelectric conversion element 20 in the box portion 24, and then filling the injection resin material such as epoxy resin, the magnetic core 12 moves with respect to the core holder 22. It can be firmly bonded and fixed so that it does not exist.

Therefore, a clamp type ammeter as a completed product including the clamp sensor according to the present invention is, for example, -1.
Even when the change in the unbalanced voltage of the magnetoelectric conversion element 20 such as a Hall element is monitored under a temperature environment of 0 to 55 ° C., the magnetic core 12 and the magnetoelectric conversion element 20 are kept in an immovable state, It is possible to exhibit excellent characteristics under a change that follows the change well.

The present invention has been described above with reference to the illustrated example, and the specific embodiment thereof is not limited to this. For example, the inner surface 2 of the core holder 22
Regarding the position and the number of the inclined surfaces 25a formed on the magnetic core 5, as long as the gap 35 is formed between the magnetic core 12 and the pressure contact piece 32, the pressure contact piece 32 can surely fix the position. It can be appropriately determined as desired. The shapes of the one side core piece portion 14 and the other side core piece portion 17 are
As long as the magnetoelectric conversion element 20 is intervened and can be combined into a substantially U shape, it can be appropriately designed, for example, a combination of the I shape and the L shape.

[0034]

As described above, according to the present invention, in the core holder, the gap width between the magnetic core composed of the one side core piece and the other side core piece gradually decreases in the depth direction. 1
Since the inner surface is provided with the inclined surface capable of forming the above-mentioned void, it is possible to fix the position of the magnetic core while individually making surface contact with the press-contact pieces press-fitted into the void. In particular, it is more preferable when the pressure contact pieces are separately press-fitted into the cavities formed between the core holders where the one-side core piece portion and the other-side core piece portion face each other in each of the three directions. In this state, the magnetic core can be positionally fixed to the core holder.

Therefore, even if the change of the unbalanced voltage of the magnetoelectric conversion element is monitored under a severe temperature environment, the finished product equipped with the present invention has excellent characteristics under the change following the temperature change. Can be demonstrated.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a clamp sensor according to the present invention including a one-side sensor section and a other-side sensor section which are divided into two parts. The disassembled perspective view which shows arrangement | positioning relationship.

2A and 2B are enlarged views showing a main part structure in FIG. 1, in which FIG. 2A is a transverse sectional view, FIG. 2B is a longitudinal sectional view taken along the line AA in FIG. (c) shows the longitudinal cross-sectional view of the BB line part in (a), respectively. Cross-sectional view.

FIG. 3 is an explanatory view showing a fixing state of a magnetic core to a core holder using a pressure contact piece according to the present invention, divided into cases (a) to (c).

FIG. 4 is a vertical cross-sectional view illustrating the internal structure of a conventional clamp sensor.

5 is an enlarged view showing the structure of the main part of the clamp sensor shown in FIG. 4, in which (a) is a cross-sectional view,
(B) shows the longitudinal cross-sectional view of the XX line part in (a), respectively.

[Explanation of symbols]

11 One side sensor section 12 magnetic core 13 Butt 14 One side core part 14a Corner part 15 Vertical side 16 side 16a Butt end face 17 One side core part 18 Vertical side 19 Horizontal piece 19a Butt end face 20 Magnetoelectric conversion element 22 Core holder 23 Abutment 24 Box section 24a inner corner 25 Inside 25a inclined surface 26 Bottom plate 27 Side plate 29 Positioning rib 30 support ribs 32 Pressure contact piece 33 Vertical surface 34 Slope 35 void 42 shield case 43 Bottom

Claims (3)

[Claims] 1. A clamp sensor comprising a one-side sensor part and an other-side sensor part which are open-closed and face-to-face mate with each other to form a substantially rectangular magnetic circuit when closed. The sensor unit has a magnetic core composed of one side core piece and the other side core piece that are abutted in a substantially U shape, and a magnetoelectric conversion element interposed in the abutting portion of the magnetic core.
At least a core holder in which a magnetic core in which the magnetoelectric conversion element is interposed is fixed, a shield case in which the core holder is housed, and an injection resin material that integrally fixes these constituent members, and the core holder is When the one-side core piece and the other-side core piece are placed as the magnetic core before being filled with the injected resin material, the gap width between the magnetic core and the magnetic core gradually decreases in the depth direction 1 or more. Is provided with an inclined surface capable of forming a void portion on its inner side surface, and a pressure contact piece having a slope corresponding to the inclined surface is press-fitted into the void portion to fix the position of the magnetic core. Characteristic clamp sensor. 2. The voids are separately formed on the inner side surface of the core holder where the one side core piece portion and the other side core piece portion face in each of the three directions. Clamp sensor. 3. The press-fitting stop position of the press-contact piece is variable in relation to the gap width of the gap portion.
Clamp sensor described in.