JPH025402B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a hair dryer with an electric leakage prevention means.

[Background technology]

Generally, a hair dryer is used to dry and style washed hair, and is placed near a bathroom vanity. By the way, recently, as lifestyles have become more diversified, people have placed washstands close to the bath so that people can do their hair on the spot after taking a bath, and they have installed a commercial power outlet near the bath. In some cases, electrical appliances can be used. However, making it easy to use electrical appliances like hair dryers near water in this way
While using the appliance, you may accidentally drop it into water such as a bathtub, and if you put your hand into the water to pick it up, you will receive an electric shock due to the leakage current from the appliance, and a minute current (50 mA) will occur. Even then, there was a risk of electrocution.

[Purpose of the invention]

The object of the present invention has been made in view of the above points, and is to provide a hair dryer that is safe even if the main body of the device is accidentally dropped into water, where current leakage is immediately prevented and there is no risk of electric shock when picked up. It is to be.

[Disclosure of the invention]

The present invention comprises: a blowing means; a heating means for heating the wind generated by the blowing means; the heating means is covered with an enclosing frame which is a non-charged metal part; and a ground wire having one end connected to the enclosing frame. , an earth leakage detection means having a zero-phase current transformer that connects the other end of the ground wire to the power supply side and detects a leakage current flowing between the charging part of the heating means and blowing means and the enclosure frame; The present invention is equipped with an earth leakage/cutoff switch means connected to the power source side of the earth leakage detection means and having a double-cut contact for cutting off current to the blowing means and the heating means in response to an earth leakage detection signal. When a hair dryer is dropped into water, a leakage current flows between the live part of the heat generating means and the surrounding frame that approaches it, and this is detected by the leakage detection means, and the power supply and disconnection switch means are activated. It works.

An embodiment of the invention is shown in FIGS. 1 to 3. That is, this hair dryer includes a blower fan 1 and a heater 2. 3 is the ventilation fan 1
4 is a temperature control thermoswitch that prevents the temperature of the heater 2 from rising too high;
5 is a temperature fuse, 6 is a diode bridge, 7
is a smoothing capacitor, 8 is a voltage dividing resistor, 9 is a power switch, 10 is a 3-core power cord consisting of a ground wire 11 and a pair of power wires 12, 13 is a power plug connected to a commercial power outlet, and 15 is a leakage The leakage current and disconnection circuit 15 includes a current leakage detection means 16 consisting of a zero-phase current transformer (ZCT);
In the embodiment, the leakage current cutoff circuit 15 is formed by a switch means 17 consisting of a trip relay (TRY) having double cut contacts ra and rb which are turned off by the leakage detection signal from the leakage detection means 16.
It is integrated within the power plug 13.

Here, the leakage current and the double cut contact of the disconnection circuit 15 are
A ground wire 11 connected between one of ra and rb and a zero-phase current transformer (ZCT) is connected via a connection terminal 19 to the surrounding frame 18 of the heater 2, which is a non-charged metal part. This connecting terminal 19 is joined to the surrounding frame 18 by grommets or spot welding as shown in FIG. is ensured.

Now, when the main body 20 of the appliance is dropped into water and water enters around the heater 2, water flows from the charged parts of the heater 2, motor 3, etc. to the surrounding frame 18 of the heater 2 and the ground wire 11. Leakage current flows. At this time, the current flowing through the power supply lines 12, 12 becomes unbalanced by the current flowing through the ground wire 11, and an earth leakage detection signal is output from the earth leakage detection means 16, which is a zero-phase current transformer (ZCT). This earth leakage detection signal drives the trip relay (TRY) that constitutes the double-ended switch means 17, and the contacts ra,
rb is turned off. At this time, the ground wire 11 is also disconnected from the power supply, so after the contact is turned off, the device body 2
0 is completely disconnected from the power supply and there will be no leakage.

Also, regardless of whether the ground wire 11 is connected to the ground side of the power supply or the live wire side, if it is dropped into water, a leakage current will flow through the ground wire 11, so a zero-phase current transformer (ZCT) is used. Since it is detected and contacts ra and rb are turned off, there is no need to pay attention to the polarity of the power supply side. Here, if the ground wire 11 is connected to the power wire 12 on the side that is directly connected to the power switch 9, even if the power switch 9 is off, a leakage current will flow in the ground wire when the appliance body is dropped into water. so the contacts
ra and rb can be turned off.

Therefore, when the main body of the hair dryer is dropped into water, the leakage current is activated and the disconnection circuit 15 is activated to instantly stop the current leakage, so there is no risk of electric shock when the user picks it up. , it can now be used safely near bathrooms, etc. In addition, since it is equipped with a ground wire 11 connected to the surrounding frame 18, which is a non-charged metal part of the device main body 20, it cannot be placed in water that is not grounded, such as in water in a sink bowl of a bathroom vanity. Electrical leakage detection means 1 even if the appliance main body 20 is dropped
Electrical leakage can be detected at step 6, and the switch means 17 can be reliably operated to prevent electric leakage. In addition,
If the device main body 20 is dropped into grounded water, a general leakage current that does not pass through the ground wire 11 will also flow.

〔Effect of the invention〕

As described above, according to the present invention, one end of the ground wire is connected to the enclosure frame of the heat generating means, and the other end of the ground wire is connected between the load side of the double-cut contact and the zero-phase current transformer. If the hair dryer is accidentally dropped into water, a leakage current will flow through the ground wire, so it can be detected by the leakage detection means and the double cut contact can be opened, so there is no risk of electric shock when picking up the hair dryer. In particular, because the other end of the ground wire is connected between the load side of the double-cut contact and the zero-phase current transformer, the hair dryer It is possible to reliably detect current leakage even when dropped into grounded or unearthed water, and the double-cut contact turns off more easily than when the other end of the ground wire is connected to the power supply side of the double-cut contact. This has the effect that no leakage current flows through the ground wire after the grounding.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of an embodiment of the present invention, FIG. 2 is a partially cutaway front view showing a hair dryer, and FIG. 3 is a perspective view of a main part of a heater portion. 1...Fan (air blowing means), 2...Heater (heating means) 11...Earth wire, 16...Earth leakage detection means, 17...Power supply cut-off switch means, 18...
...Enclosing frame, 19...Connection terminal, ra, rb...Double cut contact.

Claims (1)

[Claims] 1. A blowing means, a heating means that heats the air generated by the blowing means and is covered by an enclosure that is a non-charged metal part, a ground wire connected at one end to the enclosure, and Earth leakage detection means having a zero-phase current transformer that connects the other end of the line to a power supply side and detects a leakage current flowing between the charging part of the heating means and blowing means and the enclosure frame, and this earth leakage detection means 1. A hair dryer comprising: an electric leakage/cutoff switch means having a double-cutting contact connected to a power supply side of the air leakage means to cut off current supply to the air blowing means and the heating means in response to an earth leakage detection signal.