JPS589571B2 - Contactless power supply device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a new power supply device intended for power supply to mobile equipment, machine tools, etc. whose installation locations are frequently changed.

Conventionally, there are methods for this type of power supply, such as using a long power cord and using a trolley.
The present invention aims to provide a new θ゜ power supply device using a transformer.

That is, the present invention provides a transformer with a plurality of cores with a primary winding arranged in parallel, and a core with a secondary winding facing the appropriate number of cores with a primary winding at a minute gap from the core row. The cores are arranged, and current is applied to the primary winding of the core with the primary winding that faces the core with the secondary winding.An example of this will be explained based on the drawings as follows. It is as follows.

Fig. 1 is a front view of the embodiment, and Fig. 2 is an electric circuit diagram. 1 is a sill-shaped primary core (3 Plan view shown in Figure 4
2 is the length of S3 [S3=5(S
1+82)] is also a sill-shaped secondary core (see the bottom view shown in FIG. 5).

The primary core 1, secondary core 2, and dummy core 3 are made of non-quality magnetic materials such as laminated silicon steel plates, ferrite cores, and amorphous. are wound with a primary winding 1a and a secondary winding 2a, respectively, and when power is supplied, the secondary core 2 is placed in close contact with the five primary cores 1 or faces the five primary cores 1 with a small gap between them. It is located.

As shown in FIG. 2, each primary winding 1a is connected to a high frequency signal via a proximity switch S or a manual switch that is turned on while the secondary core 2 faces the primary core 1. The AC power source E is connected to, for example, a high frequency inverter.

The reason why the high frequency AC power source E is used is to make the cores 1 and 2 smaller and lighter.
Each winding is made of fine stranded wire wound with 2 to 3 turns in order to reduce the skin effect caused by high frequencies.

With the above structure, the secondary core 2 having the secondary winding 2a can be brought into close contact with or close to the primary core 1 as shown in the first figure, and the primary winding 1a can be energized. For example, power can be supplied to the load H using the principle of a transformer.

Therefore, although this device has the following limitations, it is effective for supplying power to machine tools that are frequently moved and used, and as a new means of contactless power supply to mobile equipment.

As is well known, the performance of power transmission by a transformer is better as the voltage fluctuation rate due to load is smaller, that is, as the magnetic coupling between the primary and secondary windings is higher. It is also necessary to make the gap small to prevent the power factor from decreasing due to the excitation current.

Although a detailed explanation will be omitted in this section, the leakage inductance can be reduced by making the slot shape of the core shallower and wider, increasing the diameter of the winding bundle, and designing the number of turns to be smaller.

As shown in the figure, this power supply device needs to supply power to the primary windings 2a (five in the embodiment) facing the secondary core 2.

At this moment, for example, one primary winding is de-energized (four are energized)
In this case, since the 20th factor of the secondary magnetic flux does not interlink with the primary, this magnetic flux acts in the same way as the secondary leakage magnetic flux, worsening the voltage fluctuation rate and significantly reducing transmission performance.

However, if you energize one extra piece (6 pieces),
Since the primary winding equivalently has a large gap or acts as an actor, it becomes an inverter load with a value almost equal to the leakage inductance of a single unit, resulting in an overcurrent, which is protected against the protection normally provided in high-frequency inverter E. The shutoff device operates,
Power transmission and reception will be suspended.

Therefore, it is necessary to be careful about energizing when driving.

This energization problem can be solved by the operator's attention in the case of machine tools that do not move continuously (stationary power supply), but when applying the present invention to moving equipment, the primary winding Proximity switch jl-0, 4-1 connected to
, 4-2, 4-3, etc. must be switched on in sequence, so an abnormal inrush current flows into the primary winding 1a at the time of switch-on, causing a high wave If the inverter stops transmitting power, the transmission performance becomes unstable, making it impossible to put it to practical use.

The second invention discloses one means for solving this problem, in which the secondary core 2 is not magnetically coupled with the secondary core in the forward and backward direction of movement, but is interlinked with the adjacent primary winding. A dummy core is provided.

To explain this using an example, as shown in Fig. 6,
Dummy cores 3, 3 that move together with the secondary core 2 are provided before and after the secondary core 2 with a distance of S2.

If the dummy cores 3 and 3 are installed on the secondary side in this way, even if the extra primary winding mentioned above is energized, the primary winding will still be able to operate at a high frequency with a value equivalent to the self-inductance. Since this becomes a load on the inverter and is limited to an increase of about 20 times the excitation current, the high-frequency inverter is able to continue operating without stopping.

That is, in FIG. 6, when the secondary moves to the right, the dummy core placed on the right side (front in the direction of movement) first faces the primary winding 1a, and as a result, the primary core 1 and the dummy core 3 A magnetic path is prepared through the gap between them, and as the approach progresses further, the proximity switch S is turned on and 1
In the next winding, a reverse induced voltage is generated due to this magnetic path, so that no excessive current flows, and only the excitation current of this magnetic path flows.

Then, approaching further to the right, primary core 1 and secondary core 2
When the two face each other, the primary side already has magnetic flux, so the length S3 of the secondary side core 2 is set to 5 as shown in the figure.
If S1+5S2 is selected, the total magnetic flux of the secondary core 2 will not change, right? .

In the case of the embodiment, the total length of the secondary side is S,=781+782.

Generally, the dimension (length) 83 of the secondary core 2 is the same as that of the primary core 1.
When the dimension (length) of is 81 and the interval is 82, S3-n
(S1+82), total length S4 is (n+2) (S1+82)
It is expressed as

However, n is the number of secondary cores facing the primary core 1.

In design, the average magnetic flux density B1 of the primary core 1 is B1 = B
It is expressed as maxX, but since it is necessary to reduce the magnetic flux density, S2 should be made as small as possible.

For the same reason, it is desirable that the proximity switch 4 is turned on or off when S1-82 faces each other.

Therefore, the length of the dummy core 3 is the length S1 of the primary core 1.
It is best to arrange them before and after the secondary core 2 with an interval equal to the primary core interval S2.

As described above, by providing the dummy core 3, it is possible to prevent an inrush current when the proximity switch closes, and also to reduce the voltage fluctuation rate due to movement, and it is possible to reduce it to zero by design.

The above two embodiments are both single-phase cases, but they can also be applied to three-phase cases, although the windings become more complicated.

FIG. 7 is a bottom view of the secondary core 2' in the case of three phases, and FIG. 8 is an end view thereof. Three slots may be provided.

In the case of three-phase, the transmission capacity is as follows if the core volume and area are the same:
It increases about 1.5 times.

[Brief explanation of drawings]

Fig. 1 is a front view of an embodiment of the present invention, Fig. 2 is an electric circuit diagram,
Fig. 3 is a plan view of the primary core, Fig. 4 is a side view of the same, and Fig. 5 is a plan view of the primary core.
The figure is a bottom view of the secondary core, FIG. 6 is a front view of a different embodiment, FIG. 7 is a bottom view of the secondary core in the case of three phases, and FIG. 8 is a side view of the same. 1...Primary side core, 2...Secondary side core, 3...Dummy core.

Claims (1)

[Claims] 1 A plurality of 1s each having a primary winding connected in parallel to a power supply.
Cores with secondary windings are arranged in parallel, and an appropriate number of cores with secondary windings are arranged facing the primary winding cores with a small gap from the core row, and the current is supplied to the secondary side. A contactless power supply device characterized in that the contactless power feeding device is applied to a primary winding of a core with a primary winding that faces a core with a winding. 2. Multiple 1s with their respective primary windings connected in parallel to the power supply.
Cores with secondary windings are arranged in parallel, and an appropriate number of cores with secondary windings are arranged facing the primary winding cores with a small spacing between the core rows and the primary winding cores. The secondary winding core is configured to be relatively movable in a straight line, and the secondary winding core faces the primary winding core array with a small gap in front and rear in the moving direction of the secondary winding core. A contactless power supply device characterized in that a dummy core that moves linearly together with the core is provided, and current is applied to a primary winding of a core with a primary winding that faces the core with a secondary winding.