JPS61134006A - Stationary induction electric apparatus - Google Patents

Abstract

PURPOSE:To obtain a magnetic clamp having sufficiently high mechanical strength by inclining the cut surface of a gap to the laminating surface of the magnetic clamp. CONSTITUTION:Force working in parallel with a cut surface can be reduced extremely as costheta times an large as force working in the width direction by forming an angle theta in the oblique direction to the laminating surface of a magnetic clamp 8a regrading the cut surface. The sectional area of the gap 10a is brought to 1/costheta times, and frictional force between gaps sections is increased extremely, thus largely improving mechanical strength. Accordingly, strength to force working in the axial direction of the magnetic clamp 8a can be made more excellent than conventional devices.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to stationary induction electric appliances such as transformers and reactors, and particularly to stationary induction electric appliances equipped with magnetic clamps for controlling magnetic flux leakage from windings. For the improvement of: related to.

[Technical background of the invention and its problems]

In static induction appliances, the amount of magnetic flux leaking from the windings is increasing due to the reduction in size and weight. An increase in leakage magnetic flux not only increases stray loss occurring in internal structures such as tanks and iron cores, but also induces local temperature increases, which may affect product performance and reliability from various viewpoints. has been viewed as a problem. In order to eliminate or reduce such inconveniences, recently, annular magnetic clamps made of magnetic thin plates such as silicon steel plates have been installed at the upper and lower ends of the windings to actively attract magnetic flux leaking from the windings and to tighten the iron core. Measures are being taken to control leakage magnetic flux, such as allowing magnetic flux to flow into places with low magnetic resistance, such as yoke iron, to reduce the amount of magnetic flux penetrating into other structures.

A conventional core type transformer is shown in Fig. 4. Core yokes 2 are arranged at the upper and lower ends of the core legs 1 to magnetically couple the core legs of other phases.

The side faces VC of the core leg 1 and the core yoke 2 are firmly tightened with a contact plate 3 and a clamping metal fitting 4 applied thereto. This iron core leg 1 has an inner winding 6 and an outer winding 7 wound coaxially.
An annular magnetic clamp 8, shown in FIGS. 5(a) and 5(b), which is formed by winding a ferromagnetic thin plate such as a silicon steel plate, is arranged at the upper and lower ends of 't. These transformer internal elements are housed in a tank 9 together with an insulating medium.

In the above-mentioned conventional transformer, as shown in FIG. 4, the leakage magnetic flux φ from between the inner winding 6 and the outer winding 70 is attracted to the magnetic clamp 8 at the upper end of the winding, and is then passed through it. It flows in the circumferential direction and enters the lower end of the core yoke 2. Therefore, the leakage magnetic flux that enters the clamping fitting 4, the iron core leg 1, etc. is significantly reduced, and as a result, the loss generated therein is also greatly reduced. This magnetic clamp 8 also has a great effect on preventing local overheating.

However, in such a structure, the magnetic clamp 8 is subject to axial winding tightening force and strong electromagnetic force in the event of a short circuit, so there is a risk of damage.1) Mechanical strength is required, and the structure is required to support the magnetic clamp. It had the disadvantage of being complicated.

In the conventional magnetic clamp 8 shown in FIG. 5(a), Q)lK, one cut was made in parallel to the axial direction. For this reason, the gear 1o portion was designed to be easily displaced in response to an axial force.

[Purpose of the invention]

In consideration of the above points, the present invention aims to provide a stationary induction electric appliance having a magnetic clamp having a sufficiently high mechanical strength.

[Summary of the invention]

The present invention reduces the force acting parallel to the cut surface (by making the gap cut surface of the magnetic clamp inclined with respect to the laminated surface of the silicon steel strip of the magnetic clamp), thereby reducing the force acting parallel to the cut surface, thereby reducing the gap between the magnetic clamp and the insulator sandwiched therein. It is characterized by increasing the bonding area of the cut surfaces to increase the frictional force between the cut surfaces and improve the mechanical strength.

[Embodiments of the invention]

The present invention will be explained with reference to an embodiment shown in FIG. According to the present invention, as shown in FIGS. 1(a) and 1(b), the cut surface is made to have an angle θ obliquely with respect to the laminated surface of the magnetic clamp 8a. By doing this, the force acting parallel to the cutting surface can be made very small, cosθ times the force acting in the axial direction. Also, the cross-sectional area of the gear 10a is 1/cosθ
The frictional force between the gap parts is extremely large, and the mechanical strength can be greatly improved. According to the structure of the present invention, it is possible to make the magnetic clamp 8a superior in strength to the force acting in the axial direction, compared to the conventional magnetic clamp 8a.

Figure 2 (at, (bl) and Figure 3 (a), (
Other examples are shown in bl.

In FIG. 2, the cross-sectional shape of the gear 10b is shaped like a staircase as shown in the figure. According to this structure, the mechanical strength is greatly improved because the cut portions are pressed against each other in the axial direction.

Figure 3 shows two conventional magnetic clamps 8C used, and 100 parts of the gap between each unit magnetic clamp as shown in Figure 3(a).
They are arranged by moving them in the circumferential direction. The two-layer structure improves mechanical strength.

〔Effect of the invention〕

As mentioned above, according to Kinoe 5jJJvc, a core leg, a core yoke arranged at both ends of the core leg to magnetically connect the core legs, a winding wound around the core leg, and this winding. It is formed by winding a ferromagnetic plate placed at both ends of the
In a stationary induction electric appliance equipped with a magnetic clamp with a gap formed in the middle of the annular shape so as not to form a turn, and a container for storing the clamp with an insulating medium, the cut surface of the gap is laminated with the magnetic clamp. Since it is made to be inclined with respect to the plane, a stationary induction electric appliance having a magnetic clamp with sufficiently high mechanical strength can be obtained.

[Brief explanation of the drawing]

FIG. 1(a) is a plan view of the magnetic clamp in the present invention,
Figures 1 and 3) are front views of the same magnetic clamp, Figures 2 and 3.
The figures show other embodiments of the present invention, in which (a) is a plan view, (b) is a front view, FIG. 4 is a longitudinal cross-sectional view of a conventional stationary induction electric appliance, and FIG. 5 (a) is A plan view of a conventional magnetic clamp (FIGS. 5 and 5) is a front view of a conventional magnetic clamp. 1... Core legs 2... Core yoke 3... Backing plate 4... Tightening fittings 5... Tightening fittings 6.
・Inner winding 7...Outer winding 8.8a, 8b, 8c
...Magnetic clamp 9...Tank 10.1
0a, 10b, 10c...Gap agent patent attorney
Noriyuki Chika (and 1 other person) Figure 1 Figure 10L Figure 2 (Ban (b) Figure 3 (α) (b)

Claims (3)

[Claims] (1) A core leg, a core yoke arranged at both ends of the core leg to magnetically connect the core legs, a winding wound around the core leg, and a core yoke arranged at both ends of the winding. In a stationary induction electric appliance comprising a magnetic clamp formed by winding a ferromagnetic plate in an annular shape and forming a gap in the middle of the annular shape so as not to form one turn, and a tank storing the magnetic clamp together with an insulating medium, the gap is A stationary induction electric appliance characterized in that the cut surface of the magnetic clamp is inclined with respect to the laminated surface of the magnetic clamp. (2) A stationary induction electric appliance according to claim 1, characterized in that the gap is stepped. (3) The stationary induction electric appliance according to claim 1, wherein the magnetic clamp is a plurality of unit magnetic clamps stacked on top of each other, and the gaps between the unit magnetic clamps are shifted from each other.