JPH0298670A - Current transformer - Google Patents

Abstract

PURPOSE:To improve a workability for connecting secondary taps and to make a countermeasure easy to the manifold of the secondary taps by constituting a secondary terminal part in the manner of fixing the secondary terminals in the desired quantity to an insulating component and providing a fitting part of the secondary terminal part in a case. CONSTITUTION:The secondary terminal part 12 provided with the secondary terminals 5 in the desired quantity is selected, and leading wires 6 of a low voltage coil part are press-fixed to crimp type terminals 14 of the secondary terminals 5. After that, the low voltage coil part is housed in the case 11, and the secondary part 12 is fitted by inserting to a chamfered part of the case 11, then an opening part of the case 11 is sealed with a cover 8 applied, and also the part inserted to the chamfered part of the secondary terminal part 12 is similarly sealed. Next, spaces between the case 11, cover 8 and low voltage coil part are filled with a synthetic resin injected from an injecting part which is provided on the cover 8. The workability for connecting the secondary taps is thereby improved, and even for a current transformer having the same shape but different secondary taps, the same case can be used by only changing the secondary terminal part 12; therefore, the countermeasure can be easily made for the manifold of the secondary taps.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention provides an iron core and a secondary coil wound around the iron core, which are housed in a case made of synthetic resin, and a connection between the case and the coil. The present invention relates to a current transformer made by casting synthetic resin into a mold.

(Prior art) As is well known, the method of manufacturing a resin molded current transformer includes:
The iron core, coil, etc. are assembled into a mold, a synthetic resin is injected into the mold, and after the injected synthetic resin hardens, the mold IX! There is a method of releasing the mold and taking out the resin molded part, and a method of storing the iron core, coil, etc. in a case made of synthetic resin, and injecting synthetic resin between the case and the coil to produce a product. In the former case, the entire mold is made of injected synthetic resin, so the insulation properties can be improved by the properties of the injected synthetic resin, but it requires a mold, the manufacturing equipment becomes larger, and the manufacturing There is a drawback that there are restrictions on the molding die. On the other hand, the latter method can simplify manufacturing equipment and is suitable for small-scale mass production.

The present invention relates to a current transformer in which an iron core, a coil, etc. are housed in a case made of the latter synthetic resin, and then a synthetic resin is injected and molded.

6 to 8 show the conventional structure of the latter current transformer mentioned above, and FIG. 6 is a top view, FIG. 7 is a side view,
FIG. 8 is a partial sectional view. Its structure consists of a secondary coil 2 wound around the outer periphery of an annular iron core 1 to form a low-voltage coil part, and made of thermoplastic synthetic resin such as polyethylene terephthalate, thermosetting resin such as polyester 1limix, etc. It is housed in a case 4 formed in a shell shape and having a through hole 3. Note that one side of the case 4 is open. When stored in this case 4, the lead wire 6 of the secondary coil 2 is connected to the secondary terminal 5 provided on one surface (upper surface) of the case 4, and then,
A cover 8 having a resin-injected lower part on one side of the case 1
After that, the synthetic resin 9 was injected from the injection lower and stored in the secondary mold 2. Case 4. After the synthetic resin 9 is sufficiently filled between the covers 8, the synthetic resin is cured. Note that the through hole 3 is for passing the primary conductor through, and 10 indicates a mounting base.

(Problems to be Solved by the Invention) The current transformer configured as described above has the following drawbacks. That is, (1) Since the secondary terminal 5 is provided in a part of the case 4, when the secondary coil 2 is housed in the case 4 as described above, the connection work must be performed in a very narrow area at the same time. As a result, workability was extremely poor. Further, it was necessary to pay sufficient attention to the processing of the lead wire 6 within the case 4, particularly to insulation properties.

(2) Current transformers usually have multiple secondary taps, so they must be varied depending on the application.
As described above, if a part of the case 4 is provided with a mounting hole for the secondary terminal 5, a large number of cases 4 are required due to the number of secondary taps, which becomes a factor in increasing the cost of the product. Ta.

(3) As a countermeasure for the above-mentioned item (2), we have manufactured the case 4 with a large number of secondary tapped holes in advance.
Secondary tapped holes that are more than necessary need to be filled during casting, which has the drawback of increasing manufacturing man-hours. Furthermore, since it has a large number of secondary tapped holes, it may cause connection errors.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a current transformer housed in a resin case that can improve the workability of connecting secondary taps and easily accommodate a variety of secondary taps.

[Structure of the Invention] (Means for Solving the Problems) The present invention consists of a shell-shaped case made of synthetic C1 resin with an open surface on one side, an iron core, and a secondary coil wound around the iron core. A current transformer that houses a low-voltage coil section, attaches multiple secondary terminals to the case to connect the lead wires of this low-voltage coil section, and seals the front face of the case with a cover, then injects synthetic resin and hardens it. In this case, a desired number of secondary terminals are fixed to an insulating member to form a secondary terminal portion, and a mounting portion for the secondary terminal portion is provided in the case.

(Function) Connect the lead wire of the low voltage coil section to the secondary terminal section in advance, store the low voltage coil section in the case, attach the secondary terminal 8 (5) to the case, and cover the opening surface of the case. By injecting the synthetic resin into the case and curing it after drying, it is possible to facilitate the work and improve the quality.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

1 shows a top view of an embodiment of the present invention, FIG. 2 shows a side view of FIG. 1, and FIG. 3 shows a cross-sectional view taken along the line A--A of FIG. 1.

In FIG. 1, FIG. 2, and FIG. 3, the case 11 houses the low-voltage coil section as in the conventional case described above, and is made of thermoplastic resin such as polyethylene terephthalate or thermosetting resin such as polyester premix. It is formed in a shell shape, and one side is open to accommodate the low-voltage coil section, a shell hole 3 for the primary conductor is provided in the center, and a secondary terminal section 12 is attached to the top surface. It will be done. The secondary terminal portion 12 is composed of a secondary terminal mounting bar 13 and a desired number of secondary terminals 5 that are integrally fixed to the secondary terminal mounting bar 13 by molding or the like. Here, since the desired number of secondary terminals 5 is determined by the number of taps required for the current transformer, there are a plurality of types of secondary terminal sections 12. However, even if the number of secondary terminals 5 changes,
The size of the secondary terminal mounting bar 13 is made constant.

Further, the secondary terminal 5 has a crimp terminal 1 to which the lead wire 6 is connected.
4 is fixed by brazing or the like. Secondary terminal mounting bar 13
is formed into a plate shape from synthetic resin, and grooves 1 are formed on both sides along its length in order to attach it to the case 11 as shown in Fig. 4.
5 is set. In this case, for r7M15, the width of one end in the cutting direction is A1, and the width of the other end is A1.
2, the width dimension is changed along the length direction so as to have the relationship A1>A2. On the other hand, the case 11 is provided with a notch corresponding to the groove 15. That is,
As shown in Fig. 5, a notch 16 is provided with one end as an opening (shaded part), and the width of the end on the opening side is △, and the width on the other side is A2. Similarly, there is a relationship of AI>A2, and the width dimension changes along the length direction. By setting a width difference of 59 between the secondary terminal portion and the cutout portion 16 of the case 11, which will be described later, the tap position can be accurately determined and quality can be improved.

Next, the assembly order will be explained. First, the secondary terminal section 12 is
A number of secondary terminals 5 corresponding to the required number of taps are set (select one) from separately manufactured ones.The crimp terminal 1 of the secondary terminal 5 of the selected secondary terminal part
4, the lead wire 6 of the low voltage coil section is crimped. After this,
The low voltage coil 81S is housed in the case 11, and at the same time, the secondary terminal part 12 is inserted into the notch part 16 of the case 11 and attached. After that, the cover 8 is placed on the opening surface of the case 11 and sealed with an adhesive or a sealing material. Secondary terminal part 1
The insertion portion into the notch 16 of No. 2 is also sealed in the same manner. Next, the synthetic resin 9 is injected from the injection lower provided in the cover 8, and the synthetic resin 9 is injected into the case 11. After filling the space between the cover 8 and the low voltage coil portion, the filled synthetic resin 9 is cured.

[Bright Effects in 5] As explained above, according to the present invention, the following effects can be obtained. In other words, (1) The secondary terminal section is separated from the case, and the low voltage coil section can be inserted and stored in the case with the low voltage coil lead wire connected to the secondary terminal in advance, making it possible to store the low voltage coil section in a narrow space unlike the conventional case. This eliminates the need to connect parts, greatly improving work efficiency, and when the low-voltage coil is housed in the case, it is very easy to handle the lead wire to the secondary terminal, and there is no problem with insulation. , the quality can be improved.

(2) Even in current transformers with the same shape but different secondary taps,
Since the same case can be used by simply changing the secondary terminal part, there is no need to prepare many types of cases as in the past, and it is possible to reduce product costs.

(3) Conventionally, the method used was to use a case with a large number of holes for attaching secondary terminals in advance, or to additionally machine holes for attaching secondary terminals, but the former method requires unnecessary filling of holes. In the latter case, drilling requires work, which increases the number of man-hours for manufacturing, but in the present invention, this is not necessary and the number of man-hours can be significantly reduced.

[Brief explanation of drawings]

FIG. 1 is a top view showing one embodiment of the present invention, and FIG. 2 is a top view showing one embodiment of the present invention.
3 is a side view of an embodiment of the present invention shown in the figure, FIG. 3 is a sectional view taken along the line 8-1 in FIG. Figure J: and side view; Figure 5 is a top view showing other essential parts of an embodiment of the present invention; Figure 6 is a top view showing a conventional current transformer; Figure 7 is Figure 6. 8 is a side view of a conventional current transformer shown in FIG. 8, which is a sectional view taken along line A--A in FIG. 1... Iron core 2... Secondary coil 5... Secondary terminal 6... Lead wire 8... Cover 11... Case 12... Secondary terminal part 13... Secondary terminal Mounting bar 15... Groove 16... Notch

Claims (1)

[Claims] A low-voltage coil section consisting of an iron core and a secondary coil wound around the iron core is housed in a shell-shaped case made of synthetic resin with an opening on one side. In the current transformer, a secondary terminal is attached to the case, the opening surface of the case is sealed with a cover, and then a synthetic resin is injected and cured, and a desired number of the secondary terminals are fixed to an insulating member. Before configuring a secondary terminal part and providing an attachment part for the secondary terminal part in the case, and storing the low voltage coil part in the case,
A current transformer characterized in that the lead wire is connected to the secondary terminal portion.