JPH0641313Y2 - thermostat - Google Patents

Description

[Detailed Description of the Invention] a. Field of Industrial Application The present invention relates to a thermostat that opens and closes electrical contacts by thermal reaction of a bimetal.

b. Conventional Technology FIG. 3 shows a conventional type thermostat 21, in which 22 is a synthetic resin casing, and 23 is a disc formed by joining two metal plates having different expansion coefficients. Shaped bimetal, 24 is a blanker (pin), 25 is a cover, 26 is a switch means, and 27a and 27b are terminals and leg portions. The switch means 26 has the leaf spring member 29 having one end attached to the movable terminal plate 28, the movable contact 30 provided at the free end of the plate spring member 29, and the fixed contact provided on the fixed terminal plate 31.
It consists of 32 and. Further, the plunger 24 is slidably supported in the vertical direction by a synthetic resin support member 33 disposed on the upper portion of the casing 22, and is set in the forward or backward position depending on the reversal direction of the bimetal 23. It is configured to be moved. With the movement of the plunger 24, the movable contact 30 is separated from the fixed contact 32 or both of them come into contact with each other.

Now, in the state of FIG. 3, when the bimetal 23 is turned over in response to a temperature change, there is a slow-moving section S and a fast-moving section Q as shown in FIG. In the thermostat, the leaf spring member 29 is constantly pressed via the plunger 24 even during the slow-moving section S, and the bimetal 23 and the leaf spring member 29 are in a state of interfering with each other. That is, the bimetal 23 always receives the spring pressure in the opposite direction of the leaf spring member 29, and acts to prevent the reversal of the spring force. And
Further, the deformation of the bimetal 23 progresses, reaches the high-speed section Q, and is rapidly reversed to open the electrical contact. Japanese Unexamined Patent Publication No. 57-157423 discloses a metal member in which a fixing plate and a leg are integrally formed, a metal member in which a contact fixing plate and a leg are integrally formed, and an electrically insulating fixing part for connecting both the metal members. When,
An elastically deformable spring-like movable plate whose one end is fixed to the fixed plate, a movable contact provided at the other end of the spring-like movable plate, and a position corresponding to the movable contact of the contact fixing plate. Fixed contact, and a plurality of mounting pieces provided on the surface of the spring movable plate opposite to the metal members,
A bimetal, both ends of which are loosely fitted and held by the plurality of mounting pieces; and a protrusion that abuts on the bimetal,
In a thermostat in which the movable contact and the fixed contact are brought into contact with or separated from each other by deforming the spring movable plate when the bimetal is reversed, the bimetal does not have a through hole, and the central portion of the bimetal of the spring movable plate is There is disclosed a thermostat in which the protruding portion is provided at a position corresponding to, and the protruding portion contacts the bimetal.

c. Problems to be solved by the invention In the conventional thermostat, it is unavoidable that there is some variation in the operating temperature, but one of the major factors causing this variation is the bimetal, which is a temperature sensitive element. Will affect the mounting structure.

In the structure of such a conventional thermostat 21,
The disc-shaped bimetal 23 disposed on the synthetic resin support member 33 is attached such that the entire peripheral surface thereof is in contact with the support member 33 and is covered with a cover 25 from the top.
Therefore, the entire peripheral surface of the disk-shaped bimetal 23 is a supporting member.
It is also in a state of being sandwiched between 33 and the cover 25.

Therefore, not only is there a temperature difference between the temperature of the bimetal alone, which responds to the inversion of the bimetal, and the operating temperature after the thermostat is assembled, but also due to the assembled state,
There is a problem in that the operating temperature of the thermostat varies considerably.

Further, when the bimetal 23 is turned over in response to the temperature change, in the slow movement section S, the movable contact 30 is replaced by the fixed contact 32.
There is also a problem that a chattering phenomenon often occurs when trying to separate from the. In the thermostat described in JP-A-57-157423, since the bimetal is not provided with a through hole and is supported by being loosely fitted, the influence of the stress of the bimetal is small, and the bimetal can be arranged outside. Therefore, there is an advantage that the thermal response speed is fast.

However, a protrusion is provided on the movable plate to assist in reversing the bimetal. As a result, the deformation of the movable plate when the bimetal is reversed is distributed to the bimetal and the movable plate. Therefore, there is a problem that the amount of deformation of the movable plate is small. In addition, indeterminacy remains in the relative positions of the movable contact and the fixed contact. As a result, a so-called chattering phenomenon tends to occur in which the movable contact and the fixed contact are intermittent when the bimetal is inverted.

The present invention, in a thermostat using a bimetal, does not have a through hole in the bimetal, there is no stress due to the support of the bimetal, and the bimetal can be placed on the outside. The challenge is to propose a thermostat that does not cause a phenomenon.

d. Means for solving the problem The above-mentioned problem is a metal member integrally formed with a fixing plate and legs,
A metal member integrally formed with a contact fixing plate and a leg portion, an electrically insulating fixing portion that connects the both metal members, an elastically deformable spring movable plate whose one end is fixed to the fixing plate, and the spring. Movable contact provided at the other end of the flexible movable plate, a fixed contact provided at a position corresponding to the movable contact of the contact fixing plate, and a fixed contact of the spring movable plate opposite to the metal members. A plurality of mounting pieces provided on the surface, and a bimetal in which both ends are loosely fitted and held by the plurality of mounting pieces,
In a thermostat having a protrusion contacting the bimetal, wherein the movable contact and the fixed contact are brought into contact with or separated from each other when the spring movable plate is deformed when the bimetal is inverted, the bimetal does not have a through hole, The movable spring plate has a through hole at a position corresponding to the central portion of the bimetal, the fixed plate is provided with the pillar, and the pillar penetrates the through hole and abuts the bimetal. Was solved by a thermostat.

e. Action Since there is no through-hole in the bimetal, there is no stress due to the through-hole, and the characteristics do not change over time.

The support column is provided in the fixed portion through the movable plate. That is, since the bimetal can be arranged outside, the thermal response speed can be increased. Also, the limitation on the size of the bimetal is smaller than that when the bimetal is placed inside.

Since the support column is projected on the fixed portion, there is no indefinite position of the movable contact of the movable plate with respect to the fixed contact when the bimetal is inverted. Further, unlike the prior art, the deformation of the movable plate when the bimetal is reversed occurs in the entire bimetal, and the movable plate follows this, so that the displacement of the movable contact with respect to the fixed contact is large. Therefore, the chattering phenomenon can be prevented.

f. Embodiment Hereinafter, a preferred embodiment of the present invention will be exemplarily described in detail with reference to the drawings.

FIG. 1 and FIG. 2 are a cross-sectional explanatory view of a main part and a plan view thereof in the case of a normally closed contact of a thermostat according to an embodiment of the present invention.

In the figure, 1 is a main part at the time of normally closed contact of the thermostat, 2 is a fixed part made of synthetic resin, a metal member integrally forming a fixing plate 8 and a leg portion 7a also serving as a terminal, a contact fixing plate 9 and a terminal. A metal member integrally formed with the dual-purpose leg portion 7b is formed integrally with a synthetic resin at intervals so as to be electrically insulated from each other.

At one end of the fixed plate 8, there is a spring movable plate 4 whose one end is spot-welded. The movable part has a width substantially equal to the width of the bimetal 3, and mounting pieces 5a are provided at two positions on the movable part. The bimetal 3 is fitted at two points with some play, and the falling prevention pieces 5b are provided at two places to prevent the fitted bimetal 3 from falling off in the lateral direction. A movable contact 10 is provided at the other end of the spring movable plate 4, and a switch means 6 is configured with a fixed contact 11 provided on a fixed contact plate 9 to open and close an electric contact by thermal reaction of a bimetal 3. . Further, a through hole 13 for a projection 12 is formed near the center of the spring movable plate 4, and a column 12 protruding from the other end of the fixed plate 8 penetrates the through hole 13, The tip of the bimetal 3 comes into contact with the vicinity of the center of the bimetal 3.
Especially when the bimetal 3 is not inverted, the tip of the protrusion 12 must be the bimetal 3 when inverted due to thermal reaction.
It has a structure that abuts near the center of. The case and the coated lead wire for external connection are omitted.

In the switch means 6 of the thermostat 1, the electric contact is always closed by the pressing force of the spring of the spring movable plate 4, but in the process in which the bimetal 3 thermally reacts with a temperature change, the bimetal 3 begins to thermally react. Spring movable plate 4
Against the pressing force of, the movable contact 10 is separated from the fixed contact 11 until the electric contact forms an opening.
It is set within the distance of the fast-moving section Q of the bimetal 3 shown in the figure. That is, in the slow-moving section S of the bimetal 3,
The tensile force of the bimetal via the spring movable plate 4 does not act because the bimetal 3 itself is fitted into the mounting piece 5a of the spring movable plate 4 with some play.

Therefore, when the bimetal 3 reacts with the temperature change, the spring movable plate 4 is not deformed during the gradual movement section S, and the force due to the reaction of the bimetal 3 does not occur when the bimetal 3 enters the fast movement section Q. Acts on the spring movable plate 4. Then, as indicated by the phantom line in FIG. 1, the bimetal 3 is rapidly inverted to deform the spring movable plate 4 and separate the movable contact 10 from the fixed contact 11 to form an electric contact open. .

It should be noted that the section in which the spring function of the spring movable plate 4 does not interfere with the thermal response of the bimetal 3 may be included in the entire slow-moving section, or in part in the fast-moving section.

When the bimetal 3 is inverted due to thermal reaction, the tip of the column 12 protruding from the other end of the fixed plate 8 has a through hole 13 in the spring movable plate 4.
Since it penetrates through and contacts the vicinity of the center of the bimetal, the movement distance of the bimetal 3 near the center when reversing is expanded with the fixed end of the spring movable plate 4 to which the bimetal is attached as a fulcrum. Then, the movable contact 10 is largely moved, so that the movable contact 10 is reliably separated from the fixed contact 11. In the thermostat of JP-A-57-157423, deformation occurs when the bimetal is inverted,
Since the movable plate is distributed to the movable plate, the deformation amount of the movable plate due to the reversal of the bimetal is small, whereas in the present invention, the deformation occurs along the entire length of the bimetal, and the movable plate follows this, so that the deformation amount of the movable plate is large. .

Further, the structure of attaching the bimetal 3 to the spring movable plate 4 is not limited to the attachment of the two parts and the structure thereof in the above-mentioned embodiment, and other means having the same function may be used. Of course.

g. Effect of the Invention As is clear from the above description, according to the thermostat of the present invention, the temperature difference between the reversal temperature of the bimetal alone and the operating temperature of the thermostat is eliminated or minimized, and the operation of the thermostat is minimized. It has the effect of minimizing the temperature variation.

Furthermore, since the opening and closing of the electrical contact is performed in the rapid motion section of the bimetal, and the moving distance of the movable contact is large, the chattering phenomenon of the electrical contact is eliminated and the electrical contact can be opened and closed with high accuracy. It can provide a stable thermostat.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of a thermostat according to an embodiment of the present invention, FIG. 2 is a plan view of FIG. 1, FIG. 3 is a sectional view of a conventional thermostat, and FIG. 4 is a bimetal thermal reaction. It is explanatory drawing of a characteristic. 1 ...... main part of thermostat, 2 ... fixed part of synthetic resin molding, 3 ... bimetal, 4 ... spring movable plate, 5a ... mounting piece, 5b ... falling prevention piece, 6 ... switch means, 7a, 7b …… Legs that also serve as terminals, 8 …… fixing plate, 9 …… contact fixing plate, 10 …… movable contact, 11 …… fixed contact, 12 …… support, 13 …… through hole, 21 …… conventional Thermostat, 22 …… synthetic resin casing, 23 …… bimetal, 24 …… plunger (pin), 25 …… cover, 26 …… switch means, 27a, 27b …… leg part, 28 …… movable terminal board, 29: leaf spring member, 30: movable contact, 31: fixed terminal plate, 32: fixed contact, 33: synthetic resin support member.

Claims (1)

[Scope of utility model registration request] 1. A metal member in which a fixing plate (8) and a leg portion (7a) are integrally formed, a metal member in which a contact fixing plate (9) and a leg portion (7b) are integrally formed, and the both metal members are combined. An electrically insulating fixed portion (2), an elastically deformable spring movable plate (4) having one end fixed to the fixed plate (8), and the other end of the spring movable plate (4). Movable contact (10), a fixed contact (11) provided at a position of the fixed contact plate (9) corresponding to the movable contact (10), and the both metals of the spring movable plate (4). A plurality of mounting pieces (5a) provided on the surface opposite to the member, and a bimetal (3) having both ends loosely fitted and held by the plurality of mounting pieces (5a),
In a thermostat having a column (12) which comes into contact with the bimetal, and when the bimetal is inverted, the spring movable plate (4) is deformed to bring the movable contact (10) and the fixed contact (11) into or out of contact with each other. The bimetal (3) does not have a through hole, the spring movable plate (4) has a through hole (13) at a position corresponding to the center of the bimetal, and the fixed plate (8) has the support column. A thermostat, wherein (12) is provided in a protruding manner, and the column (12) penetrates the through hole (13) and abuts on the bimetal (3).