JPS6149328A - Temperature overrise preventing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an overtemperature rise prevention device that opens the electric circuit of an iron or other appliance when the temperature rises to ensure safety.

2. Description of the Related Art Conventional Structures and Problems Generally, in electrical equipment, a thermostat having a bimetal as an operating element is used as a means for adjusting the temperature of the electrical equipment. However, since the thermostat is mechanical, malfunctions such as malfunction or seizure of contacts may occur, and there is a risk that the device may be burnt out due to excessive temperature rise. As a means for preventing this excessive temperature rise, a temperature fuse is used, and when the temperature rises excessively, the temperature fuse blows out, for example, cutting off the heater circuit to ensure safety.

Figure 8 shows an iron as an example of an electric device.A base 1 made of metal such as aluminum is equipped with a heater 2 for heating the iron. A thermostat 4 operated by a bimetal 3 is provided, and the thermostand 4 maintains the surface temperature of the base 1 at a set value. Further, a temperature heater 5 is provided in the current supply circuit of the heater 2 as a means for preventing excessive temperature rise.

Note that 6 in the figure indicates a thermostat adjustment member. Moreover, FIG. 9 shows an electric circuit.

The temperature fuse 5 has a temperature sensing element made of a crystalline organic compound or an easily fusible metal sealed inside a tube body, and when the temperature rises, the temperature sensing element melts and opens an energizing circuit.

By the way, the melting point of the temperature sensing element in the temperature fuse 5 is about 220° C. at most, and if the base 1 is directly connected to heat reception, there is no margin during normal use, and there is a problem that premature breakage occurs. Therefore, in order to reduce malfunctions, it has been necessary to locate it in a position where there is a large degree of margin, that is, on the back side of the pace cover 7 or in a space where it is difficult to receive the heat of the base 1 directly. This arrangement of the temperature fuse 5 has poor heat receiving sensitivity, and the maximum temperature of the base 1 when the temperature fuse 6 is activated is abnormally high, resulting in serious problems such as melting of the base 1, dielectric breakdown of the heater 2, fire, electric shock, etc. There was a risk of an accident. In addition, in the case of an iron, there is a problem in that the temperature rise inside the iron differs depending on its use condition, that is, when it is placed horizontally and when it is placed upright, making it prone to malfunctions such as premature cutting.

Purpose of the Invention The present invention has been made in consideration of the above-mentioned problems, and an object of the present invention is to provide an over-temperature rise prevention device that promptly detects over-temperature rises in equipment and operates accurately to improve safety and reliability. be.

Structure of the Invention In order to achieve the above object, the overtemperature rise prevention device of the present invention includes a switch of an energized circuit, a thermally responsive member that is pressurized by an opening/closing member of the switch and supports the opening/closing member;
The actuator receives the thermally responsive member and has a conductive relationship with the heated member, the thermally responsive member is made of a material that melts or melts when a predetermined temperature is reached, and the actuator applies the thermally responsive member. The second
The overtemperature rise prevention device has a pin corresponding to the opening/closing member, and the shape of the hole through which the pin passes is sufficiently larger than the external shape of the pin. It is possible to react sensitively and open the switch for safety, and to smoothly displace the opening/closing member that fits into the pin of the actuator, thereby achieving the desired operation.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 7.

In the figure, reference numeral 8 denotes the base of the iron, which is made of die-cast aluminum and has a sheath-shaped heater 9 embedded therein, so that the iron can be heated to a desired temperature by the heater 9. A space 1 formed between the base 8 and the cover 10
1 is provided with a thermostat 14 having contacts 13 that are opened and closed by a bimetal 12. Specifically, it is supported by a mounting base 16 made of ceramic or the like fixed to a part of the cover 10, and the bimetal 12 is connected by an adjustment member. The position of the can be adjusted.

One end of a first conductive plate 16 for a switch formed in a long shape is fixed to the mounting base 15, and an insulating plate 17 is interposed on the upper surface of the first conductive plate 16. Second
conductive plates 18 are stacked on top of each other.

A contact rO is provided on the corresponding surfaces near the tips of the first conductive plate 16 and the second conductive plate 18.

Ru. The first conductive plate 16 has elasticity, and its tip is given a force toward the inside of the base 8.

Moreover, the second conductive plate 18 is also elastic and has a force in the direction of the first conductive plate 16, that is, the contact points 19,
I am given the power to close 20.

An actuator 21 is provided inside the base 8 and at a position corresponding to the tip of the first conductive plate 16 . This actuator 21 is made of heat-resistant and insulating ceramic.

Moreover, this actuator 21 has a plate-like part 21b having a recess 21& on the upper surface, a protrusion 21c protruding from the center of the lower surface of the plate-like part 21b, and a cylindrical part protruding from the center of the upper surface of the plate-like part 21b. It consists of a pin 21d.

The protrusion 21c of the actuator 21 fits into a holding hole 22 formed on the inner surface of the base 8, and the protrusion 23 formed at the entry line of the holding hole 22 abuts the lower surface of the plate-shaped portion 21b of the actuator 21. , there is a heat transfer relationship between the base 8 and the actuator 21.

A cylindrical thermally responsive member 24 is provided on the upper surface of the plate-like portion 21b of the actuator 21 so as to surround the pin 21d. This thermal response sound B'24 is made of a fusible alloy, and is designed to melt due to excessive temperature rise.

The thermally responsive member 24 may be made of thermoplastic synthetic resin or low melting point metal instead of the fusible alloy. The pin 21d of the actuator 21 is inserted into the hole 16a formed at the tip of the first conductive plate 16.
The tip thereof corresponds to the inner surface of the second conductive plate 18 . The hole 16a has a shape sufficiently larger than the outer diameter of the pin 21d, for example, a round hole or a square hole as shown in FIGS. 2 and 3, so as to reduce the sliding resistance with the pin 21d. . The tip of the first conductive plate 16 presses the thermally responsive member 24 in the direction of the base 8. Said 1st. The switch formed by the second conductive plate 16,18 is connected in series with the thermostat 14, and the switch is inserted into the energizing circuit of the heater 9.

Next, the operation of the overtemperature rise prevention device having the above structure will be explained.The thermally responsive member 24 is designed not to melt or soften at the operating temperature of a normal iron. For example, when using eutectic No./Da, the bath melting temperature is adjusted by changing the blending ratio of the materials to increase the margin.

In normal use of the iron, the thermally responsive member 24 maintains its original shape, and therefore is in the state shown in FIG. That is, 1st. The contacts 19.20 of the second conductive plate 16.18 are closed, and the energization circuit of the heater 9 is closed. The temperature is adjusted by opening and closing the thermostand 14. In this state, a distance A is maintained between the first conductive plate 16 and the line of the plate-like portion 21b of the actuator 21, and a distance B is maintained between the tip of the pin 21d of the actuator 21 and the second conductive plate 18. ,A
〉There is a relationship of B. Further, the heat of the base 8 is transmitted from the protrusion 23 to the thermally responsive member 24 via the plate-like portion 21b of the actuator 21.

If the thermostat 14 fails and its contacts remain closed, and the temperature of the base 8 becomes abnormally high, the thermally responsive member 24 will melt. Therefore, the tip of the first conductive plate 16 that presses the thermally responsive member 24 loses its support and is displaced by the distance A in the direction of the base 8, as shown in FIG. In response to this, the second conductive plate 18 also tries to displace, but since the tip position of the pin 21d of the actuator 21 does not change, the second conductive plate 18 is displaced by the distance B, and further displacement is prevented. be done. Since the interval A) is B, the first. If the spacing between the second conductive plates 16 and 18 is not wide, the contacts 19 and 20 will open to cut off the current to the heater 9 and ensure its safety.

The overtemperature rise prevention device of the above embodiment has a configuration in which the conductive plate 16 serving as a switch element pressurizes the thermally responsive member 24, and the thermally responsive member 24 melts or collapses to displace the conductive plate 16 and open the switch. This ensures reliable operation and improves safety. Further, the thermally responsive member 24 has a good heat transfer relationship with the base 8 due to the pressurizing force, so that the thermally responsive member 24 can reliably respond to an excessive temperature rise. Furthermore, the heat-responsive member 24 is quickly melted, crushed, and deformed by pressurization, contributing to rapid operation of the switch.

SWIN-1 of the first conductive plate 16? During the opening operation, when the elongated conductive plate 16 is displaced, the position of the hole 16a moves slightly in the axial direction, but the twill shape is aligned with the pin 21d.
Since it is sufficiently larger than that, the sliding resistance will not increase.
Operates smoothly. Moreover, if the hole 16a is a square hole, the number of contact points with the pin 21d will be reduced, allowing for a more effective displacement operation of the conductive plate 16.

In addition, although an iron was used as the device in the above embodiment,
The device may be an electric heating device other than an iron, such as an electric cooker or an electric stove. Further, the base 9 may be an electrically insulating material such as a cover other than a metal body.

Effects of the Invention As is clear from the description of the above embodiments, the temperature overrise prevention device of the present invention reduces the supporting force of the switch member which is pressurized by bath melting or bath crushing of the heat sensitive member when the temperature reaches a predetermined temperature. Since the switch is configured to open, the device operates without malfunction as an overtemperature rise prevention device, and provides a highly safe and reliable device. Further, the heat sensitive member is pressed against the heated member such as the base by the switch member and has a good heat receiving relationship, and responds sensitively to an excessive rise in temperature of the heated member. In particular, the opening/closing member of the switch that presses the heat sensitive member can be smoothly displaced and accurately opened by adjusting the fitting hole with the actuator.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of essential parts of an iron equipped with an overtemperature rise prevention device according to an embodiment of the present invention, FIGS. 2 and 3 are plan views of a switch conductive plate, and FIG. Figure 5 is a plan view of the temperature rise prevention device, Figure 6 is its sectional view, Figure 7 is its sectional view in the same operating state, and Figure 8 is the conventional temperature rise prevention device. A sectional view of the attached iron and FIG. 9 are its electric circuit diagrams. 8...Pace of iron (heated member), 9.
... Heater, 14 ... Thermostat,
16...First conductive plate of the switch, 16a...
...hole, 18 ... second conductive plate of switch, 19, 20 ... contact, 21 ... actuator, 21d ... pin , 24...thermally responsive member. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 Figure 4

Claims (2)

[Claims] (1) A switch of an energizing circuit, a thermally responsive member that is pressurized by the switching member of the switch and supports the switching member, and an actuator that receives the thermally responsive member and has a heat conducting relationship with the heated member. The thermally responsive member is made of a material that melts or melts when it reaches a predetermined temperature, and the actuator passes through a hole in the opening/closing member of the switch that pressurizes the thermally responsive member and corresponds to the second opening/closing member. 1. An overtemperature rise prevention device, comprising a pin that passes through the pin, and a hole through which the pin passes is formed to be sufficiently larger than the external shape of the pin. (2) The overtemperature rise prevention device according to claim 1, wherein the pin has a circular outer shape and the hole is a square hole.