JPS62165824A - Thermostat - 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 The present invention relates to a thermostat 1711 configured to form a circuit in response to a change in temperature, and more particularly to a thermostat 1711 configured to form a circuit in response to a change in temperature. This relates to a thermostat equipped with a thermostat.

An example of a well-known resin mostat is that one end of a bimetallic switch element is fixed to one of two mutually parallel plate-shaped contacts forming a frame, and a bimetallic switch element is connected to a fixed contact provided on the other contact carrier. The base body is constructed in such a way that an electrical contact provided at the other end of the switch element engages, and two pins are passed through the frame in a close and sliding manner to connect the contact carrier, and the two pins are inserted into the frame in a sliding manner. However, there are thermostats that are mounted so that they are kept parallel to each other. This thermostat can be provided with external heating means and/or internal heating means, or can have a different heat capacity, and can also be equipped with various embodiments of contact carrier connection terminals. .

For this type of thermostat, US Pat. No. 45'2
It is listed in 8540@.

The thermostats disclosed in various embodiments of the above patents are configured to affect current sensitivity, the on/off switch time of the thermostat, or both. This patent also discloses various connection and attachment possibilities.

For example, various embodiments are shown as connection terminals for contact carriers. Also disclosed is an external heating element energized with switched current, which element can be placed in a means of selected heat capacity. Also disclosed are contact carriers made of resistors on one or both sides, which can be combined with special shapes of the carrier and means of selected heat capacities.

Furthermore, in order to keep the thermostat in the open circuit state until the main current is cut off after it becomes an open circuit state, a heat source with PTC characteristics is connected in parallel with the above embodiment, so that a so-called manual reset function can be obtained. The possibility of doing so is also described in the above patent.

The disadvantage of this configuration is the additional parts (requires additional space)
The two problems are that a contact means is required, and special attention must be paid to photographing, etc. Another disadvantage is that when the automatic reset function is activated without using an additional heat source, the switchback time is greatly affected by the ambient temperature, and the range of the switchback time is limited by the switchback temperature, ambient temperature, etc. .

SUMMARY OF THE INVENTION The present invention aims to take advantage of the advantages and eliminate the disadvantages of the known thermostats described in the aforementioned patents. For this purpose, at least one pin is made of PTC material, a material that is characterized by a positive temperature resistance coefficient and, in particular, a sharp resistance rise characteristic at the Curie temperature, and is often used for that purpose. The heat generated electrically during energization is transferred from this pin to the thermostat's heat-sensitive switching element by convection and radiation.

By using the above n'eli, the range of switchback time and reset function is widened, and the field of application is widened. Additionally, it can be easily installed without any additional parts, and can even be installed in narrow spaces. This thermostat is reliable in terms of manufacturing technology and can accurately determine the switchback time to return to the on state.

A simple and strong structure can be obtained by making one or both pins using PTC material with a certain Curie temperature. Heat generated at the PTC pin is transferred to the thermostat switch member by radiation, conduction, and convection. Due to the dense structure, the temperature of the switch member during energization is determined primarily by the Curie temperature of the pin, providing self-control of the heat generated in the pin. At relatively low temperatures, an artificial direct ambient temperature occurs. If the Curie temperature of the PTC pin is selected between the thermostat's switch-on and switch-off temperatures, the thermostat will not return to the on state even if the ambient temperature drops. The thermostat will not return to the on state unless the current is interrupted from an external source, a so-called manual reset function.

However, if the Curie temperature is selected so that this artificial direct ambient temperature can be used when the temperature drops in a situation where thermal equilibrium is obtained at a temperature close to or below the switch-on temperature, the time required for the switch to reclose will be reduced. It becomes very long. In this case, it switches on automatically and the switch-on time is less affected by the ambient temperature. As the Curie temperature approaches the switch-on temperature, the cooling time of the thermostat increases.

If only one pin is made of PTC material, safety against overheating of the pin due to pin shorting is guaranteed.

The other pin made of insulating material allows the thermostat to maintain its functionality and structure.

Example The present invention will be described in detail below using the accompanying drawings.

The base body 1 is provided with mutually parallel plate-shaped contact carriers 2, 3. These carriers are preferably made of metal and are fixed on two parallel pins 4.5.

Preferably, at least one pin is made of ceramic PTCO.

The pin extends through a deep hole in the contact carrier.

The contact carriers are adapted to slide back and forth and are held in equilibrium with each other by pins during assembly and adjustment of the thermostat. Each contact carrier carries a connecting terminal 6, which extends in the longitudinal direction of the basic body and extends on opposite ends of the basic body.

A switch element 7 is fixed to the inner side surface of one of the contact carriers 2, 3 at a position 8 on the corresponding carrier by welding or the like. This switch element is made of bimetal and is provided with a setting part 9 that enables a self-switching function by a snap action at a predetermined switch-on temperature, and is configured so that it can be switched back at low temperatures. It is preferable to do so.

If the direct ambient temperature remains above the switchback temperature, switchback will not occur until mechanically reset or the direct ambient temperature decreases. As is well known, the switchover temperature is determined by the setting shape and bimetal mounting method.

In this embodiment, the bimetallic setting portion 9 is circular, but it may have a different shape.

A fixed contact is provided at the movable end of the switch element,
This contact engages with a fixed contact 11 fixed to the inner side of the other contact carrier. The contact carrier may have any shape. For example, an opening 12 as shown in FIG. 1 may be provided so that almost the entire switch element 7 is laterally exposed. Also, if the contact carrier is made of a resistive material, the current sensitivity of the thermostat will be increased. The two contact carriers can be made of the same material or of different materials. The contact may have three layers, for example, Ni, Cu, and AO (Cdo). Further, it is not necessary to provide a setting section on the switch element. The connection terminal can be configured in various shapes and its position may be changed. Also,
It is possible to utilize heat as well as external or internal heating means.

In such a configuration, terminal 6.6 is connected to an electrical circuit, and the circuit is opened when contact 10.11 is engaged.

On the other hand, when the bimetal 7 is displaced due to a selected temperature change and the contacts are separated, the circuit is opened. The temperature at which the circuit opens is mainly determined by the temperature response characteristics of the bimetal or the temperature! Il
l determined by temperature. As described in the said patent, the operating temperature of the thermostat, ie the circuit opening temperature, is calibrated and adjusted by selective relative movement of the carrier 2.3 on the pin 4.5. When the temperature of the bimetal falls to a reset temperature below the operating temperature, the bimetal and contacts io, 1i re-engage to close the re-q circuit.

According to the present invention, the PTC pins 4 and 5 are made of ceramic material or the like.
Made of a material with positive temperature resistance properties.

Although this material is selected to have a relatively low room temperature resistance, the material is selected such that the pin exhibits a higher electrical resistance than the bimetal 7 and the corresponding contacts. However, although the pin material is a material that exhibits a sharp resistance increase characteristic at a certain temperature, it is preferable that the temperature is selected between the operating temperature and the reset temperature of the bimetal. In other words, when the pin generates self-heating due to the current flowing through the pin, the pin acts as a self-regulating electric resistance heater, and even if the ambient temperature fluctuates, the bimetal 7
It is preferable to stabilize at an appropriate temperature to keep it between the operating temperature and the reset temperature.

In such a configuration, if the terminals 6, 6 are connected to a circuit in which the thermostat detects the normal temperature within the temperature range monitored by the thermostat, the contact io
, i1 are in their normal engaged position, the circuit is open, and normal current flows between the carrier 2.3 via the pin 4.5. However, when the temperature monitored by the mostat exceeds a predetermined value and the bimetal 7 is heated to the operating temperature, that is, the open circuit temperature, a large current momentarily flows through the pin.
The pin material is rapidly heated to a high resistance temperature and the circuit is opened by displacement of the bimetal, completing the opening action between the carriers 2.3. However, after that, the temperature monitored by the thermostat returns to the initial level, that is, the normal level.
At a stable temperature of the pin, the bimetal 7 is kept above the reset temperature due to the heat generated by the small current flowing through the high resistance pin. Therefore, the thermostat is, for example, pin 4
It remains open until a manual reset is applied to disconnect the thermostat from the circuit, such as when the thermostat is cooled back to normal room temperature resistance.

Although specific embodiments of the present invention have been described above, the present invention includes all modifications and equivalents that can be implemented within the scope of the claims described in the specification.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the thermostat according to the present invention, and FIG. 2 is a top front view of the thermostat shown in FIG. 1.

Claims (3)

[Claims] (1) having a bimetallic switch element responsive to temperature changes, one end of which is fixed to a frame, and a movable electrical contact provided at the other end of the bimetallic switch element connected to a fixed contact provided on the frame; the frame has two parallel plate-shaped contact carriers which constitute a base body, the frame carries a bimetallic switch element and a fixed contact;
In a thermostat in which two parallel pins extend through the carriers to connect them, the carriers remain parallel to each other with the carriers sliding closely back and forth against each other. At least one of them is made of PTC material, and the heat generated electrically during energization is conducted through conduction, convection,
Thermostat characterized in that the transmission is by radiation to a bimetallic switch element. (2) In claim 1, a PTC material having an appropriate Curie temperature is used so that the electrically energized pin is stabilized at an appropriate temperature by self-control, and when the ambient temperature decreases. The thermostat is characterized in that the temperature of the bimetallic switch element settles between its operating temperature and its reset temperature. (3) The thermostat according to claim 1, characterized in that the temperature of the bimetal switch element settles at a point closer to the reset temperature than the operating temperature.