JPS5856247B2 - Air core reactor with magnetic shield - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a magnetically shielded air-core reactor.

In an air-core reactor, all of the generated magnetic flux becomes leakage flux, so if the generated magnetic flux is large, the winding is a rectangular coil made of laminated steel plates such as ferromagnetic silicon steel plates to form a closed magnetic circuit. Placed within an iron core magnetic shield and surrounding the outer periphery,
It has a configuration that reduces leakage magnetic flux.

In this way, for the purpose of air-core reactors to absorb the generated magnetic flux and reduce leakage magnetic flux, conventionally, the stacked thickness of the steel plates of the iron-core magnetic shield 1 shown in Part 1 is approximately equal to the outer diameter of the winding. value or a higher value.

For this reason, the winding is arranged and covered within the iron-core magnetic shield 1, and the central axis of the winding is generally supported by the magnetic shield via insulating rings provided at the upper and lower ends. It has become.

Therefore, a wedge made of insulating material is usually driven between the insulating ring and the iron-core magnetic shield to tighten the winding in the direction of the central axis.

However, since iron-core magnetic shields constantly vibrate when subjected to magnetic attraction, this vibration can cause the wedge to loosen, or the wedge itself to loosen due to dimensional changes due to aging, which can cause the winding to tighten or tighten. This has the disadvantage that the reliability of the equipment is impaired.

On the other hand, the inner part of the winding of an air-core reactor does not have an iron core like that found in a transformer and is hollow, so it is necessary to fix the position of the winding by some means to prevent it from shifting laterally. .

Further, when the stacking thickness of the iron core magnetic shield is large, the temperature rise of the iron core magnetic shield also becomes high, so it is necessary to promote the cooling effect and suppress the temperature rise within a predetermined value.

An object of the present invention is to provide an air-core reactor with a magnetic shield that allows reliable tightening and positioning of windings and effective cooling of an iron-core magnetic shield.

The present invention will be explained below with reference to an embodiment shown in FIGS. 2 to 4.

The structure of the iron-core magnetic shield according to the present invention is as shown in FIG. 2. As in the conventional case, a plurality of strip-shaped steel plates are stacked to form the iron-core magnetic shield 2 of the closed magnetic circuit.

At this time, according to the present invention, the core type magnetic shield 2 is provided with voids 3 at appropriate locations in the stacking thickness direction of the steel plates forming the core type magnetic shield 2.

In this illustrated example, the air core reactor with magnetic shield of the present invention, in which two new gaps 3 in the iron core magnetic shield 2 are provided in the stacked thickness direction of the steel plates, is shown in FIGS. 3 and 4. In this way, a winding 4 with an insulating cylinder 5 provided inside is arranged in a rectangular space of an iron-core magnetic shield 2 formed by laminating a plurality of steel plates and providing a gap 3.

The iron core type magnetic shield 2 forms a rectangular closed magnetic circuit by arranging fastening fittings 7 on both upper and lower sides thereof and fixing them together.

The fastening fittings 7 on both the upper and lower sides are connected by bolts or welding (not shown) by an upper connecting fitting piece 7a and a lower connecting fitting piece 7b arranged on the upper surface or the lower surface, respectively. Upper and lower connecting fitting pieces 7a,
7b is used for fixing the magnetic shield and tightening and fixing the winding 4 and positioning the winding 4 as will be described later.
An insulating ring 6 is inserted between the two.

A tightening wat 8 is inserted through each gap 3 of the iron-core magnetic shield 2 and is disposed so as to pass through the internal space of the insulating cylinder 5 inside the winding 4.

The upper and lower ends of the tightening rod 8 are screwed to the upper and lower connecting fitting pieces 7a and 7b, respectively, to connect them, and by tightening the tightening rod 8 with the screw, the winding 4 is insulated. Tightening is fixed via the ring 6.

The tightening rod 8 connecting the upper and lower connecting fitting pieces 7a and 7b is set so as to be in contact with the insulating cylinder 5, but if not in direct contact, a piece is placed between the two so that they are in indirect contact. In other words, each of the four tightening rods 8 inserted through the gap 3 is connected between both end surfaces of the winding 40 and the tightening fitting 7, and between the inner peripheral surface of the winding 4 and the tightening rod 8 itself. Since the winding 4 is tightened and fixed while being insulated by the insulating tube 5, the tightening rod 8 can prevent the winding 4 from shifting laterally.

In the illustrated example, the air gap 3 of the core-type magnetic shield 2 is utilized, and a well-known winding support bolt 9 passing through the air gap 3 is inserted through a screw hole (not shown) provided in the upper connecting fitting piece 7a. Since the winding support bolt 9 is screwed in toward the wire side and the tip of the winding support bolt 9 is brought into contact with the insulating ring 6 so as to be used together with the tightening rod 8, the tightening and fixing can be made even stronger.

Therefore, according to the present invention having the above-described configuration, a gap 3 is provided in the laminated portion of the iron core type magnetic shield 2, and the tightening rod 8 is inserted into the gap 3 between both end surfaces of the winding 40 and the tightening fitting. ,
Since the inner circumferential surface of the winding 4 and the tightening rod 8 can be tightened and fixed by controlling the position while insulating each other, this method was used for tightening the winding in the axial direction in the conventional structure. The disadvantage of the wedge is that the wedge becomes loose due to the iron core magnetic shield 2 vibrating under the magnetic attraction force.
Alternatively, it is possible to solve problems such as loosening of the wedge itself due to aging, and improve the reliability of the device by firmly tightening and fixing it.

Further, in the present invention, a structure is provided in which the lateral displacement of the winding 4 is prevented by each tightening rod 8, that is, the tightening rod 8 and the insulating cylinder 5 are provided so as to be in contact with each other, or if they are not in contact, a corresponding member is inserted between the two. By doing this, the tightening rod can prevent the hollow winding, which does not have an iron core such as a transformer, from shifting laterally, and the position of the winding can be fixed.

Furthermore, the air gap 3 provided in the laminated portion of the iron core magnetic shield 2
can be used as a duct for a cooling medium such as insulating oil or air, and can suppress the temperature rise of the iron-core magnetic shield 2 within a predetermined value.

As described above, in the present invention, it is possible to securely tighten and fix the winding in the axial direction in a magnetically shielded air-core reactor using a tightening rod that is inserted through the air gap, and to position the winding reliably. , lateral displacement can be prevented, and furthermore, the iron-core magnetic shield can be effectively cooled by utilizing the air gap.

Therefore, compared to conventional products of this kind, it is possible to achieve a great effect in that the reliability of the device can be improved.

[Brief explanation of drawings]

Fig. 1 is a schematic perspective view showing the structure of the magnetic shield of a conventional air-core reactor, Fig. 2 is a schematic perspective view showing the structure of the magnetic shield in the present invention, and Fig. 3 is a magnetic shield according to an embodiment of the present invention. FIG. 4 is a plan view showing the overall structure of the attached reactor, and FIG. 4 is a front view of FIG. 3. 2... Iron core type magnetic shield, 3... Air gap, 4... Winding wire, 5... Insulating cylinder, 6...
...Insulation ring, 7...Tightening fitting, 7a
... Upper connecting fitting piece, 7b... Lower connecting fitting piece, 8... Tightening rod, 9...
Winding support bolt.

Claims (1)

[Claims] 1 A rectangular iron-core magnetic shield is constructed by laminating steel plates with at least two gaps in the stacking thickness direction, and is fixed with fasteners placed on both upper and lower sides to form a closed magnetic circuit. and a winding disposed within an iron core type magnetic shield, an insulating tube is disposed inside the winding, and the upper and lower connecting bracket pieces are connected between the clamping brackets on both sides of the upper and lower sides, respectively. A winding support bolt inserted through the gap in the iron core magnetic shield is screwed into the upper connecting metal piece to tighten and fix the winding, wherein the gap in the iron core magnetic shield is connected to the insulating cylinder. A plurality of tightening rods arranged so as to pass through the internal space are inserted, and each of the tightening rods connects the upper and lower connecting fitting pieces and is arranged between both end faces of the winding and the tightening fitting. 1. A magnetically shielded air-core reactor, wherein the winding is tightened through an insulating ring, and each of the tightening rods is configured to contact an insulating cylinder arranged inside the winding.