JPS645843Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a positive temperature coefficient thermistor device using a positive coefficient thermistor made of barium titanate semiconductor ceramic having a positive temperature coefficient of resistance.

Positive temperature coefficient thermistors have a self-temperature control function that allows any heat generation temperature to be obtained by appropriately selecting the Curie temperature, and that when the heat generation temperature exceeds the Curie temperature, the electrical resistance increases rapidly to control self-heat generation. Because it has excellent features such as no risk of overheating, is safe and highly reliable, it has been widely used as a heat source in various heat generating devices or as a current control element in electronic and electric circuits.

The present invention combines a positive temperature coefficient thermistor with a heat-sensitive switch via a thermal delay section, and controls the operation timing of the heat-sensitive switch and the operation time of the positive temperature coefficient thermistor according to the thermal delay characteristics of the heat delay section. An object of the present invention is to provide a positive temperature coefficient thermistor device that can heat and evaporate a chemical solution such as an insecticidal solution in accordance with the operating time of the device.

In order to achieve the above object, the positive temperature coefficient thermistor device according to the present invention includes: a flat positive temperature coefficient thermistor arranged substantially horizontally; a drug solution container mounting surface formed on the upper surface side of the positive coefficient thermistor; The heat sensitive switch is thermally coupled to the lower surface of the positive temperature coefficient thermistor via a thermal delay section, and the positive temperature coefficient thermistor and the heat sensitive switch are electrically connected in series.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The content of the present invention will be specifically explained in detail below with reference to the accompanying drawings, which are examples.

FIG. 1 is a sectional view of a thermistor device according to the present invention. In the figure, reference numeral 1 denotes a flat positive temperature coefficient thermistor arranged approximately horizontally, with ohmic or non-ohmic contact electrodes 2 and 3 provided on both sides in the thickness direction, and an electrode plate 4 on the electrodes 2 and 3. , 5 are placed opposite each other. The upper surface side where the electrode plate 4 is located is used as a mounting surface for a chemical liquid container containing a chemical liquid such as an insecticidal liquid.

6 is a heat sensitive switch. In this embodiment, the switch is constructed using a manual return type bimetal switch equipped with a push button 7 and lead terminals 8 and 9, but it may also be constructed using a bimetal switch of other structure, a temperature-sensitive ferrite reed switch, etc. Good too. Further, the switch type of the heat-sensitive switch 6 may be various contact types such as a normally open contact, a normally closed contact, or a transfer contact.

Reference numeral 10 denotes a thermal delay section formed between the lower surface side of the PTC thermistor 1 and the heat-sensitive switch 6. The heat delay section 10 is provided to cause a certain time delay in the heat transferred from the PTC thermistor 1 to the heat-sensitive switch 6, and its thermal conductivity, heat capacity, and amount of heat radiation are within a predetermined range. It is chosen to obtain the delay time. The heat delay section 10 is constructed of, for example, a heat-resistant synthetic resin, various types of porcelain, an insulated metal body, an air layer, or a combination thereof, taking into consideration the thermal conditions described above. Ru.

As described above, in the present invention, the thermal switch 6 is thermally coupled to the PTC thermistor 1 via the thermal delay section 10, so the thermal switch 6 is connected to the PTC thermistor 1 after a delay time based on the thermal conduction characteristics of the thermal delay section 10. The switch operates as a time limit switch with a relatively long delay time. Furthermore, this delay time can be set over a wide range by appropriately selecting the heat conduction characteristics of the thermal delay section 10, the heat generation temperature and heat generation amount of the positive temperature coefficient thermistor 1, or the operating temperature of the heat sensitive switch 6.

The positive temperature coefficient thermistor 1 and the heat-sensitive switch 6 are
Drive as a series connected circuit. With a series connection circuit, the positive temperature coefficient thermistor 1 can be operated to generate heat until the heat sensitive switch 6 switches, and the power supply circuit of the positive temperature coefficient thermistor 1 can be cut off at the same time as the heat sensitive switch 6 switches. It is possible to realize a positive temperature coefficient thermistor device that has no residual current, is power saving, and has high safety. Furthermore, the chemical solution container placed on the electrode plate 4 can be heated for a certain period of time during which the PTC thermistor 1 is generating heat to evaporate the chemical solution and perform an insecticidal action or the like.

Next, a specific example of a positive temperature coefficient thermistor device using a series connection method will be described.

First, in FIG. 2, a heat sink 11 made of, for example, beryllia porcelain or alumina porcelain is attached to the electrode plate 4 of the PTC thermistor device shown in FIG. It has a structure in which a container 13 containing an object, such as an insecticidal solution 12, is mounted.

FIG. 3 is an electrical circuit diagram of the PTC thermistor device. By electrically connecting the electrode plate 5 of the PTC thermistor 1 and the lead terminal 8 of the heat-sensitive switch 6, the PTC thermistor 1 and the heat-sensitive switch can be connected. 6 are connected in series. In this embodiment, the heat-sensitive switch 6 has a normally closed contact structure.

In the PTC thermistor device having the above configuration, when a DC or AC voltage is applied between the electrode plate 4 and the lead terminal 9, the PTC thermistor 1 immediately starts to generate heat because the heat sensitive switch 6 is a normally closed contact. .

FIG. 4 shows an operating characteristic diagram at this time.
First, immediately after the PTC thermistor 1 starts up, its initial resistance value is low, so its heat generation temperature curves
A sharp rise along A ₁ . When the heat generation temperature reaches around the Curie temperature, its electrical resistance increases rapidly and a self-temperature control function occurs, so the heat generation temperature stabilizes at the thermal equilibrium temperature Tm. The insecticidal solution 12 and the like in the container 13 are heated and evaporated by this exothermic temperature, thereby performing an insecticidal action.

On the other hand, the heat generated in the PTC thermistor 1 is transmitted to the heat-sensitive switch 6 via the heat delay section 10 with a certain time delay. Curve A ₂ in FIG. 4 is a temperature rise characteristic curve of the thermosensitive switch 6, which rises with a gentler slope than the temperature rise characteristic curve A ₁ of the positive temperature coefficient thermistor 1.

When the temperature of the thermal switch 6 reaches its operating temperature Ts, the thermal switch 6 switches from on to off. As a result, the power supply line of the PTC thermistor 1 is cut off, and its heat generation operation is stopped. That is, the operating time of the positive temperature coefficient thermistor 1 and the container 13
The evaporation time of the insecticidal solution 12 in the switch is the time Td ₁ from the time of activation (t=o) until the temperature of the heat-sensitive switch 6 reaches the operating temperature Ts. This operation duration Td ₁ can be easily changed depending on the heat transfer characteristics of the heat delay section 10, the heat generation temperature and heat generation amount of the positive temperature coefficient thermistor 1, or the setting of the operating temperature of the heat sensitive switch 6.

FIG. 5 is a sectional view of another embodiment of the positive temperature coefficient thermistor device according to the present invention. A feature of this embodiment is that the heat retarder 10 is composed of a heat retardant 10A and an air layer 10B. The heat retardant 10A is constructed using, for example, a heat-resistant synthetic resin, various types of porcelain, or other materials having appropriate thermal conductivity. In addition, in order to provide the air layer 10B,
In this embodiment, the upper surface of a heat-resistant case 14 is fixed to the heat retardant 10A, and the heat-sensitive switch 6 is attached to the bottom of the case 14 with an air layer 10B above.

With the above structure, due to the heat insulating effect of the air layer 10B, the time delay in the transfer of heat from the PTC thermistor 1 to the heat-sensitive switch 6 becomes extremely large, significantly delaying the operation time of the heat-sensitive switch 6. I can do it. Therefore, it is possible to realize a positive temperature coefficient thermistor device in which the operation time of the positive temperature coefficient thermistor 1 and the evaporation time of the insecticidal solution 12 in the container 13 are long.

As described above, the positive temperature coefficient thermistor device according to the present invention includes a flat positive temperature coefficient thermistor arranged substantially horizontally, a drug solution container mounting surface formed on the upper surface side of the positive temperature coefficient thermistor, and the positive temperature coefficient thermistor device according to the present invention. The thermosensitive switch is thermally coupled to the lower surface side of the PTC thermistor via a thermal delay part, and the PTC thermistor and the heat sensitive switch are electrically connected in series, so that the operation of the thermosensitive switch is Provided is a positive temperature coefficient thermistor device capable of controlling the timing and operating time of a positive temperature coefficient thermistor according to the heat delay characteristics of a heat delay part, and heating and evaporating a chemical solution such as an insecticidal liquid in accordance with the operating time of the positive temperature coefficient thermistor. can do.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the positive temperature coefficient thermistor device according to the present invention, FIG. 2 is a diagram explaining its usage, FIG. 3 is its electrical circuit diagram, and FIG. 4 is its operating characteristic diagram. FIG. 5 is a sectional view in another state of use. 1... Positive characteristic thermistor, 6... Heat sensitive switch, 10... Heat delay section.

Claims (1)

[Claims for Utility Model Registration] (1) A flat plate-shaped positive temperature coefficient thermistor arranged substantially horizontally, a chemical solution container placement surface formed on the upper surface side of the positive temperature coefficient thermistor, and a lower surface side of the positive temperature coefficient thermistor. 1. A positive temperature coefficient thermistor device comprising: a heat sensitive switch thermally coupled to a positive temperature coefficient thermistor through a thermal delay section, the positive temperature coefficient thermistor and the heat sensitive switch being electrically connected in series. (2) The positive temperature coefficient thermistor device according to claim 1, wherein the heat delay section is made of a heat delay material. (3) The positive temperature coefficient thermistor device according to claim 1 or 2, wherein the heat delay section includes an air layer.