JPH09326225A - Thermo-relay - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low cost delay thermo-relay. SOLUTION: Contacts 5 are adapted to stand face to face opposite to each other on a surface of an insulation board 6 and a bimetallic strip 2 is placed over between these contacts 5. ON-type relay wherein a free end of the bimetallic strip 2 extending from one contact 5 normally keeps contact with the other contact 5 or OFF-type one wherein the free end keeps apart are sellected. A heat emitting body 3 such as a resistor or a PTC heating body is formed on a back side surface of this insulation board 6 and two lead wires 7 extending therefrom are connected to a voltage limiting side via a limit switch. The dimetallic strip 2 is blipped by turning on the limit switch. A low cost delay relay used as a delay switch and the like is thereby made possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a thermorelay that directly delays and controls a load by turning off.

[0002]

2. Description of the Related Art A conventional relay is composed of a magnetic material, a magnet coil, a spring, etc., and instantaneously controls the load by energizing the coil.

[0003]

The conventional type relay has a large number of parts and is costly. The present invention provides a low-cost relay that utilizes the convenience of a ceramic substrate and the delay property of a bimetal, and will be described in detail below with reference to the drawings.

[0004]

Means for Solving the Problems A contact is formed on the upper side surface of a thin ceramic substrate, a bimetal is laid between both contacts, and a PTC heating element is formed on the back surface of the ceramic substrate. The bimetal is always set to on or off, and it is inverted by heating. The delay time to reach the Curie temperature is significantly shortened by miniaturization.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Insulating substrate 6 made of ceramic or the like
Contact points 5 and 5 are formed to face each other on the upper side surface, and a bimetal 2 is laid between these contact points. The free end of the bimetal 2 extending from one contact 5 is set so as to be always in contact with or away from the other contact 5. The bimetal, which is always in contact, leaves the contact 5 only after reaching a predetermined temperature. The heating element 3 is formed on the back side of the insulating substrate 6, and the lead wires 7, 7 are extended from this. The heating element 3 is made of a resistance or PTC material. In the case of a PTC heating element, the bimetal 2 is set to operate below the Curie temperature. An example of the use of the thermo-relay main body 1 thus configured is shown in FIGS.

In FIG. 1, an always-on bimetal 2 is arranged in a load circuit. When the control switch 4 is turned on, a control voltage is applied to the heating element 3 to raise the temperature. The temperature rising rate differs depending on the heat capacity of the thermo-relay body 1. If the heat capacity is made extremely small by using today's integrated technology, the rate of temperature rise will be remarkably high, and it will be a fast response type. When the predetermined temperature is reached, the free end of the bimetal 2 separates from the contact 5 as shown in FIG. In the case of a PTC heating element, the bimetal 2 separates below the Curie temperature. When the PTC heating element reaches the Curie temperature, it exhibits a steep resistance value, and excessive heat generation is suppressed.
When the control switch 4 is opened, the temperature of the heating element 3 drops and the bimetal 2 returns to the on state.

FIG. 3 shows an embodiment of the shunt control system (extension switch), in which a series circuit of the control switch and the heating element 3 is arranged in parallel with the load. The bimetal 2 inserted in the load side circuit is always off. When the control switch 4 is turned on, the heating element 3 is heated and the bimetal 2 is turned on. Acts as a delay relay. The transient response depends on the heat capacity of the thermorelay body 1 and the surrounding thermal environment. In the embodiment of FIG. 2, one bimetal 2 is arranged on one ceramic substrate 6, but a plurality of bimetals 2 may be arranged to control a large number of loads. Further, a plurality of pairs with the PTC heating element 3 can be arranged to individually control the load.

[0008]

In summary, according to the present invention, the contacts 5 and 5 are formed facing each other on the upper surface of the thin ceramic substrate, the bimetal 2 is laid between both contacts, and the heating element 3 such as a resistor is attached to the back surface of the ceramic substrate. Since this heating element 3 is connected to the control voltage via the control switch 4, a low-cost delay relay can be provided.

[Brief description of drawings]

FIG. 1 is a circuit diagram when a thermo-relay body made of bimetal which is always on is arranged in a load circuit.

FIG. 2 is a front view of the thermorelay body.

FIG. 3 is a circuit diagram when a thermo-relay body made of bimetal which is always off is arranged in a load circuit.

[Explanation of symbols]

 1 Thermo-relay body 2 Bimetal 3 Heating element 4 Control switch 5 Contact point 6 Insulation board 7 Lead wire

Claims (3)

[Claims] 1. A thermorelay in which a bimetal 2 and a heating element 3 for supplying operating heat thereto are arranged on the surface of an insulating substrate 6. 2. A contact 5, on the upper surface of the thin ceramic substrate.
5 is formed facing each other, and the bimetal 2 is laid between both contacts,
A thermorelay in which a PTC heating element 3 is formed on the back surface of a ceramic substrate. 3. A contact 5, on the upper surface of the thin ceramic substrate.
5 is formed facing each other, and the bimetal 2 is laid between both contacts,
Attach a heating element 3 such as a resistor to the back surface of the ceramic substrate,
A thermorelay that connects this heating element 3 to a control voltage via a control switch 4.