JPH0243071Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a liquid displacement switch used, for example, to discharge a drain from a drain tank of an air conditioner when a predetermined amount of drain is accumulated in the tank.

A conventional switch of this type is as shown in Fig. 2, in which floats 6 and 7 each having a permanent magnet 4 and 5 built inside are attached to the outer periphery of a sealed protective tube 3 that houses reed switches 1 and 2. It is provided to correspond to the switch. A power source 8, a main switch 9, a self-holding relay 10, and a motor 11 are connected to these reed switches as shown in the figure.

Therefore, when the protective tube 3 is placed in a drain tank (not shown), the float 6 first floats due to the increase in the drain, and the reed switch 1 is closed by the magnetic field distribution of the permanent magnet 4 inside.

When the drain increases further, the float 7 floats and the reed switch 2 is closed due to the magnetic field distribution of the permanent magnet 5 inside. When each reed switch is closed, the motor 11 is operated to pump out drain from the drain tank by a pump (not shown), and the main switch 9 is closed by the relay 10.

As the level of the drain decreases, the float 7 gradually lowers, and when it reaches a certain position, the magnetic field of the internal permanent magnet 5 no longer acts on the reed switch 2.
Reed switch 2 opens. However, the main switch 9
is still closed by relay 10, so motor 1
1 continues to rotate and pumping out the drain continues.

Note that when the level of the drain drops, the float 6 descends, and the magnetic field of the permanent magnet 4 ceases to act on the reed switch 1, and the reed switch 1 is opened at this point.

Therefore, the main switch 9 is opened and the motor 11 is stopped, so that pumping out of the drain is also stopped.

However, as is clear from the above, in such a conventional device, two reed switches are required, and a relay 10 must also be provided, and the number of parts is large and the interconnection is complicated.

This proposal was developed in view of the above drawbacks.According to this proposal, one reed switch is provided inside the tubular sealed protection tube, and its position is adjusted in the vertical direction with respect to the protection tube so as to surround the protection tube above the protection tube. A ring-shaped permanent magnet that can be attached to the drain tank is attached, and a ring-shaped float with a ring-shaped permanent magnet inside is installed to surround the protective tube, and when the protective tube is inserted into the drain tank. As the drain increases, the ring-shaped float with the ring-shaped permanent magnet rises along the protective tube, and together with the upper permanent magnet, a magnetic field is formed, and this magnetic field acts on the reed switch, closing it. It operates the motor and pump connected to the reed switch.

An embodiment shown in FIG. 1 will be described below.

20 is a tubular sealed protection tube made of glass or the like and houses a reed switch 21 therein.
A ring-shaped permanent magnet 22 is provided above the protection tube 20. The permanent magnet 22 has a support portion 23 made of a non-magnetic material at its center, and a threaded portion 24 into which a nut 25 is screwed.

26 is a disc-shaped magnetic body that expands the magnetic path as described later.

A ring-shaped float 27 is provided below the protection tube 20.
is provided, and can move up and down along the protection tube 20 according to changes in the water level of the drain in the drain tank of the air conditioner (not shown). A ring-shaped permanent magnet 28 is provided inside the float 27.

A stopper 29 is provided at the lower end of the protective tube 20 to prevent the float 27 from descending any further.

One end of lead wires 32 and 33 are connected to the contacts 30 and 31 of the reed switch 21, respectively, and each lead wire is guided outside from the protective tube 20 and connected to a motor connected to a pump (not shown).

Since the present plan is configured as described above, when there is little drain in the drain tank, float 2
7 does not rise, and since there is an appropriate distance between it and the magnet 22, no magnetic field is generated during this time, and therefore the contacts 30 and 31 of the reed switch 21 do not close.
Therefore, the motor does not rotate and the pump connected to this motor does not operate.

However, as the amount of drain in the drain tank increases, the float 27 rises along the protective tube 20 and approaches the permanent magnet 22 above.

And the permanent magnet 28 inside the float 27 and the permanent magnet 2
When the distance from the reed switch 2 reaches a predetermined value, a magnetic field is generated, and this magnetic field causes each contact 30, 3 of the reed switch 21 to
1 closes. When the reed switch 21 is closed, the motor and hence the pump are driven to start discharging the drain from the drain tank.

For this reason, the drain in the drain tank decreases, but as the drain decreases, the float 27 moves to the protective tube 20.
, the distance between the permanent magnets 28 and 22 gradually increases, and when this distance reaches a predetermined value, the magnetic field disappears. Therefore, reed switch 21
The motor opens and the pump stops.

In the above operation, when the nut 25 is rotated to adjust the position of the permanent magnet 22, the distance between the permanent magnet 28 in the float 27 is adjusted, and the timing of generation and extinction of the magnetic field is adjusted, as well as the reed switch. The timing of opening and closing can also be adjusted.

Further, by providing the disk-shaped magnetic body 26, it is possible to expand the magnetic path, and the difference between the opening and closing points of the reed switch can be increased.

As described above, according to the present invention, not only can the timing of generation and extinction of the magnetic field be adjusted, but also the timing of opening and closing of the reed switch, compared to the conventional system, only one reed switch is required.
Also, since there is no need for relays, the number of parts is small.
Mutual connections are simple, and therefore this type of switch can be provided at low cost.

[Brief explanation of drawings]

FIG. 1 is a schematic longitudinal sectional view of the displacement switch of the present invention, and FIG. 2 is a schematic circuit diagram using a conventional switch. 20... Protection tube, 21... Reed switch, 2
2, 28...Permanent magnet, 27...Float.

Claims (1)

[Scope of utility model registration request] A reed switch, a long and thin protection tube that hermetically surrounds the reed switch, and a ring-shaped ring that is attached above the protection tube so as to cover it and whose position can be adjusted vertically with respect to the protection tube. A liquid displacement switch comprising a permanent magnet and a ring-shaped permanent magnet housed in a ring-shaped float covering the protection tube so as to move up and down the protection tube.