JPH0430701B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention relates to a vibration-resistant thermostat that opens and closes electrical contacts by thermal response of a bimetal.

b. Prior Art Figure 4 is a longitudinal cross-sectional view of a conventional thermostat taken along arrows C to C in the cross-sectional view of Figure 5, and shows the thermostat in a state where the electrical contacts are normally closed. be. This thermostat has already been proposed by the present applicant in Japanese Patent Application No. 59-50097. That is, in the figure, the case 16 of the thermostat has a slightly rectangular parallelepiped shape with a thin thickness, and one end surface thereof is open. An insulating paper 17 is disposed on the inner surface of the case 16, and a movable member support plate 18, a movable plate 19, a bimetal 20, etc. are housed in a space A surrounded by this insulating paper 17.

The movable member support plate 18 is formed from a single metal plate, and one end 18 of this support plate 18
One end 1 of a movable plate 19 made of a plate spring member is shown at a.
9a is fixed by spot welding or the like. Also,
A disc-shaped bimetal 20 is held on both sides of the support plate 18 by four bent pieces 18b bent at substantially right angles in the same direction. That is, the peripheral edge of the bimetal 20 is connected to the bent piece 18.
They are inserted and fixed at predetermined positions into notches 18c formed in the respective portions b.
Note that this bimetal 20 is disposed opposite to the movable plate 19 described above with a slight distance therebetween.
A convex portion 19b formed at the middle portion of the movable plate 19 corresponds to approximately the center portion of the bimetal 20.

Further, a fixed terminal plate 21 is disposed on the insulating paper 17, and an insulating material 22 is interposed between the fixed terminal plate 21 and the supporting plate 18 facing thereto. A fixed contact 23 is provided on the fixed terminal plate 21, and this fixed contact 23 is arranged corresponding to a movable contact 24 provided at the free end of the movable plate 19. Note that, under normal conditions, the movable contact 24 is pressed into engagement with the fixed contact 23 by the spring pressing force of the movable plate 19.

On the other hand, a covered electric wire 25a is connected to the fixed terminal plate 21. In addition, the support plate 18 has covered electric wires 2
Therefore, this electric wire 25b is connected to the movable plate 19 via the support plate 18. Note that the connecting portions of the pair of covered wires 25a and 25b are fixed with a synthetic resin filler 26.

Further, the bimetal 20 is arranged corresponding to an opening 27 formed in the support plate 18. Note that this opening 27 is formed to quickly transmit changes in ambient temperature to the bimetal.

Next, to explain the operation, first, when the bimetal 20 is curved downward as shown by the solid line in FIG. The electric wires 25a and 25b are connected to each other by crimping and engaging the fixed contact 23. Furthermore, if the ambient temperature becomes high and the bimetal 20 reverses its warping direction and curves upward as shown by the imaginary line in FIG.
9, the movable contact 24 is separated from the fixed contact 23 against the spring force of the movable plate 19. As a result, the electric wire 25
The connection between a and 25b is opened, and these electric wires 2
A circuit (not shown) connected to 5a and 25b is switched to a predetermined state.

c. Problems to be Solved by the Invention According to the conventional thermostat described above, if it is placed in a stationary state, it is possible to reliably open and close the electrical contacts depending on the ambient temperature. However, the movable plate 19 has one end 19a fixed to one end 18a of the movable member support plate 18 as a fulcrum.
The length is structurally long as shown in FIG.
Since the distance is considerably larger than the distance from the fulcrum of the movable contact 24, the contact pressure due to the spring pressing force of the movable plate 19 applied to the movable contact 24 becomes small. Therefore, when external vibrations are applied to this thermostat, the movable contact 24 vibrates, and the normally closed state of the contact often becomes instantaneously open. That is, this thermostat has a problem in that it is susceptible to external vibrations because it is structurally unable to maintain a large contact pressure at the electrical contacts and a large force for driving the contacts.

d. Means for Solving the Problems The present invention was made in view of the above points, and its purpose is to solve the problems of the conventional thermostat and to maintain its performance against external vibrations, that is, to improve vibration resistance. Our goal is to provide a thermostat with a

To achieve the above object, the present invention provides a thermostat that opens and closes electrical contacts by transmitting the thermal response of a bimetal to a movable member having a spring property and having movable contacts, in which the movable members are parallel to each other. It consists of a movable contact plate and a movable plate, each of which has one end fixed to the other, and is supported by a fixed member via an insulating member so that the vicinity of the fixed member serves as a fulcrum, and the two points of the fixed member are The bimetal, which is fitted through an insulating member, is disposed between the movable contact plate and the movable plate, and one of the movable contact plates is provided with substantially the bimetal at both ends on its free end side. A support piece is provided vertically from a place corresponding to the central part, and is latched to the movable plate so that the movable contact plate is interlocked with the one-way movement of the movable plate, and the other movable plate has the above-mentioned support piece. A convex portion is provided to protrude from approximately the center of the bimetal, and further, the distance from the fulcrum on the free end side of the movable contact plate is approximately the same as the distance from the fulcrum of the convex portion of the movable plate. The movable contact provided at the same position and the fixed contact provided on the fixed member opposite to the movable contact constitute the electrical contact, and the thermal response of the bimetal causes the movement of the movable plate to be controlled. The movable contact plate is interlocked to bring the movable contact into contact with the fixed contact with a pressing force approximately equal to the pressing force on the movable plate necessary to separate the movable contact from the fixed contact. It is characterized by

e Embodiments Hereinafter, preferred embodiments of the present invention will be described in detail by way of example based on the drawings.

FIG. 1 is a cross-sectional explanatory diagram of a thermostat showing one embodiment of the present invention (a cross-sectional view taken along the line A-A in FIG. 2), and FIG. 2 is a cross-sectional view taken along the line B-B in FIG. FIG. 3 is an explanatory cross-sectional view of the electrical contact in the open state after the bimetal inversion operation in FIG. 1.

In FIG. 1, a thermostat case 1 has a thin rectangular parallelepiped shape with one end open. A movable member 2, a fixed member 7, a bimetal 4, etc. are housed in the space therein.

The movable member 2 has a movable contact plate 3a and a movable plate 3b each having spring properties, and a movable plate 3b and a movable plate 3b on the upper side.
Movable contact plates 3a are arranged on the lower side in parallel with a constant interval, and one ends are fixed to each other and the vicinity thereof is used as a fulcrum and supported by a fixed member 7. Furthermore, a movable part terminal 12 is formed in the extended part. These two movable contact plates 3a and movable plate 3b
A bimetal plate 4 is disposed between them, straddled between the two points of the insulating members 10a and 10b constituting the fixing member 7, and fitted with a slight clearance. on the other hand,
The movable plate 3b is provided with a long convex portion 5b protruding in a direction perpendicular to its longitudinal direction, as shown in FIG. 2, corresponding to approximately the center of the bimetal plate 4. On the other hand, support pieces 5a are bent upward and suspended from positions corresponding to approximately the center of the bimetal plate 4 on both sides of the movable contact plate 3a in the longitudinal direction, and the movable contact plate 3b
By bending parallel to the upper surface of the movable plate 3b so as to overlap it,
Regarding the one-way movement of the movable plate 3b, the movable contact plate 3a
are linked. Furthermore, a movable contact 6 is provided at the other end of the movable contact plate 3a, and forms an electric contact together with a fixed contact 9 provided on a fixed plate 8, which will be described later. The distance from the fulcrum of the movable contact 9 provided on the movable contact plate 3a is approximately equal to the distance from the fulcrum of the center of the long convex portion 5b protruding from the movable plate 3b.

The fixed member 7 supports the movable member 2,
and an insulating member 10a made of synthetic resin to which one end 4a of the bimetal plate 4 is fitted is provided on the fixed plate 8,
The movable member 2 is supported and fixed together with a support member 11 also made of synthetic resin disposed thereon. Further, the other end 4 of the bimetal plate 4 is attached to one end of the fixed plate 8.
Insulating member 10b made of synthetic resin for fitting b
is provided. A fixed portion terminal 13 is formed by extending to the other end of the fixed plate 8, and together with the movable portion terminal 12, covered electric wires 14a and 14 for external connection are provided.
b, and the opening of the case 1, including the connecting portion, is filled with a synthetic resin filler 17.

Next, to describe the operation of the above-mentioned thermostat, first, when the bimetal 4 is normally curved downward as shown in FIG. Therefore, the electric contact is in a closed state by being crimped and engaged with the fixed contact. When the ambient temperature changes and the bimetal 4 reverses due to thermal response and curves upward as shown in FIG. 3, the bimetal 4 is pressed and moved by the long protrusion 5b of the movable plate 3b, so the movable contact plate 3a The movable contact 6 is interlocked with the movable plate 3b by the support piece 5a.
It is separated from the fixed contact 9 against the spring pressing force of a. As a result, the covered electric wires 14a, 1 for external connection
The electrical contact output of 4b becomes an open circuit.

In this case, the position of the long convex portion 5b of the movable plate 3b and the position of the movable contact 6 provided on the movable contact plate 3a are as follows.
Since it is located at approximately the same distance from the fulcrum, the movable contact 6
The contact pressure due to the movable plate 3b and movable contact plate 3a
The relationship is approximately equal to the force that drives the movable plate 3b against the spring pressing force. As a result, the force outputted by the central portion of the bimetal 4 when reversing is the same as that of a conventional type thermostat, and is required to separate the movable contacts 6 at the positions of the long convex portions 5b of the movable plate 3b of the present invention. Force (movable plate 3b at the same location
Even if the force required to separate the movable contact 24 at the position of the protrusion 19b of the movable plate 19 in the conventional case is equal to
The contact pressure caused by the movable contact can be made considerably larger than in the past.

Therefore, the contact pressure of the movable contact 6 and the force for driving the movable contact 6 of this thermostat can be made considerably larger than those of the conventional thermostat, so even if vibrations greater than the conventional level are applied to this thermostat from the outside, it is easily suppressed. There is no need to worry about the movable contact opening (under normal conditions).

Even if the normal contact pressure of the movable contact is increased to about 50 grams, the force that drives the movable contact can be obtained relatively easily by the reversing force caused by the thermal response of this type of bimetal.

As a result of the above, this thermostat can exhibit sufficient performance even when installed in a place where vibrations are relatively high. Furthermore, since the contact pressure can be increased, the contact resistance between the electrical contacts can be lowered, so there is an advantage that the contact current can be increased.

It should be noted that the technology of the present invention is not limited to the technology in the above embodiments, but can also be applied to means of other modes that perform the same function, or even when the open/close states of the electrical contacts are reversed. Of course.

f Effect As is clear from the above description, according to the thermostat according to the present invention, the movable members are arranged parallel to each other, one end of each is fixed to each other, and the movable members are supported so that the vicinity thereof serves as a fulcrum. A bimetal consisting of a movable contact plate and a movable plate, which are fitted at two points on the fixed part, is disposed between the movable contact plate and the movable plate, and due to the thermal response of the bimetal,
The movable contact plate is interlocked with the movement of the movable plate, and the movable contact is fixed in place with a pressing force approximately equal to the pressing force on the movable plate necessary for separating the movable contact from the fixed contact. Since it is brought into contact with the contact point, it has the effect of realizing a vibration-resistant thermostat that can maintain its performance against vibrations applied from outside the thermostat.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional explanatory diagram of a thermostat showing one embodiment of the present invention (a cross-sectional view taken along the line A-A in Fig. 2), and Fig. 2 is a cross-sectional view taken along the line B-B in Fig. 1. , FIG. 3 is a cross-sectional explanatory diagram of the state where the electrical contacts are open after the bimetal reversal operation in FIG.
The figure is a longitudinal cross-sectional view of a conventional thermostat (a cross-section taken along the line C--C in FIG. 5), and FIG. 5 is a cross-sectional view of FIG. 4. 1... Case, 2... Movable member, 3a... Movable contact plate, 3b... Movable plate, 4... Bimetal plate,
4a, 4b...One end of the bimetal plate, 5a...Support piece, 5b...Long protrusion, 6...Movable contact, 7...
Fixed member, 8... Fixed plate, 9... Fixed contact, 10
a, 10b...Insulating member, 11...Supporting member, 1
2...Movable part terminal, 13...Fixed part terminal, 14
a, 14b... Covered electric wire.

Claims (1)

[Scope of Claims] 1. A thermostat that opens and closes electrical contacts by transmitting the thermal response of a bimetal to a movable member having a spring property and having movable contacts, wherein the movable members are disposed parallel to each other, and each It consists of a movable contact plate and a movable plate that are fixed to each other at one end and are supported by a fixed member through an insulating member so that the vicinity of the fixed member serves as a fulcrum, and the movable contact plate and the movable plate are supported at two points of the fixed member through the insulating member. The above-mentioned bimetal that is fitted with the above is disposed between the above-mentioned movable contact plate and the movable plate, and one of the above-mentioned movable contact plates is provided with a portion corresponding to approximately the center of the above-mentioned bimetal at both ends of the free end side. A support piece is provided vertically from each of the movable plates, and the movable contact plate is latched to the movable plate so as to be interlocked with the movement of the movable plate in one direction. a convex portion is provided to protrude from the movable contact plate; The movable contact and a fixed contact provided on the fixed member opposite to the movable contact constitute the electric contact, and the movable contact plate is linked to the operation of the movable plate by the thermal response of the bimetal. necessary to separate the movable contact from the fixed contact by
A vibration-resistant thermostat characterized in that the movable contact is brought into contact with the fixed contact with a pressing force substantially equal to the pressing force applied to the movable plate.