JPS6047730B2 - reactor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic shield for suppressing induction disturbances caused by leakage magnetic flux of a reactor, particularly a reactor mounted on a vehicle.

In general, the magnetic flux in the reactor has a symmetrical distribution around the magnetic core 1-1, as shown in FIG. 1, as Φ.

Therefore, for example, if a signal detection sensor or the like is located at point A, the leakage magnetic flux of the reactor will cause an induction disturbance.

In order to suppress this induced disturbance, conventionally a shield device 2 was disposed outside the coil 1 of the reactor as shown in FIG. This shielding device 2 is usually made of a non-magnetic and highly conductive material such as an aluminum plate or a copper plate in a cylindrical or box shape, with a coil symmetrically surrounding the magnetic core 1-1 for ease of manufacture and strengthening of the structure. It was made up of materials. Therefore, it is not affected by the DC magnetic flux shielding device 2, but the pulsating magnetic field is
Bookmarked by shield device 2, Φ.

The magnetic path length is extended as follows. The magnetic flux Φ is the magnetomotive force AT
) If magnetic resistance is R, then Φ=-.

In an air-core reactor, R increases in proportion to the magnetic path length, so in the one shown in FIG. 2, the magnetic path length is increased by the shield device 2, and the magnetic flux affecting point A is reduced.

However, in such a device, although the effect is simply that the magnetic path length is lengthened, the shielding device must be made longer in the direction of the magnetic core in order to make the effect noticeable, which has the disadvantage of increasing the size of the device. It was hot. This invention attempts to eliminate such drawbacks of the conventional system by configuring the shield device asymmetrically with respect to the magnetic core to reduce the magnetic flux density at necessary positions around the reactor. .

The principle of this invention and each embodiment will be explained below based on FIGS. 3 to 6. That is, compared to the magnetic flux Φ when the sinold device 2 is installed in a symmetrical state with respect to the magnetic core as shown in FIG. In this case, the magnetic resistance decreases in the area where there is no shielding device, so the magnetic flux increases, the magnetic flux density in the magnetic core increases, and the required AT of the magnetic core increases.

Due to the increase in the required AT in the magnetic core portion, the magnetic flux Φ2 passing near point A becomes smaller, and the relationship of magnetic flux Φ>Φ2 in case A is established. Therefore, as shown in FIG. 4, the shielding device 2 is configured such that the part of the reactor coil 1 that is close to point A is long in the direction of the magnetic core, and the part that is far from point A is short. It gathers in the part far from point A where the magnetic path length is short, and the part close to point A becomes smaller like Φ2.

Incidentally, as shown in FIG. 5, the shield device 2 may be arranged only on one side with respect to the magnetic core, that is, on the point A side.

In addition, as shown in FIG. 6, in addition to the shielding device 2 for suppressing induction disturbances at the target location, a magnetic member 3 is placed at a portion far from the target location to further increase the overall magnetic flux. It may be possible to suppress leakage pulsating magnetic flux in the vicinity of . As mentioned above, the reactor according to the present invention has a magnetic shielding device made of a non-magnetic and highly conductive material arranged asymmetrically with respect to the magnetic core of the coil, thereby reducing pulsating magnetic flux at a desired location around the reactor. This can effectively suppress induction disturbances.

[Brief explanation of the drawing]

1 and 2 are side sectional views showing a conventional reactor, and FIG. 3 is a side sectional view for explaining the principle of the present invention.
4 to 6 are side sectional views showing each embodiment of the present invention. In the figure, 1 is a coil, 2 is a shield device, and 3 is a magnetic member.

Claims (1)

[Claims] 1. A reactor equipped with a coil and a magnetic shielding device made of a non-magnetic and highly conductive material arranged asymmetrically with respect to the magnetic core of the coil. 2. The reactor according to claim 1, wherein the magnetic shielding device has different lengths in the direction of the magnetic core. 3. The reactor according to claim 1, wherein the magnetic shielding device is arranged only on one side with respect to the magnetic core. 4. The reactor according to claim 3, wherein a magnetic member is disposed on the other side with respect to the magnetic core.