JPS6142264Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an automatic temperature regulator with an improved contact opening/closing structure.

BACKGROUND ART Automatic temperature regulators incorporated in various electric heating devices generally utilize bimetal, and the conventional configuration thereof is as shown in FIG. In other words, a is a bimetal, and b and c are contact terminals.
It is a contact plate with b ₁ and c ₁ . These contact plates b,
c has an elastic force in a direction that abuts each other, and both contact terminals b ₁ and c ₁ are joined by this elastic force. Further, an action point _a1 provided at the tip of a bimetal a is opposed to one contact plate c, and an adjustment rod e extending from an adjustment screw d is in contact with the other contact plate b.

As a result, the bimetal a deforms in a curved manner in response to the change in ambient temperature, deforms the contact plate c against the elastic force via the point of action _a1 , and separates the contact terminals _b1 and _c1 . It's getting old. When changing the opening timing relative to temperature, the adjusting rod e is moved up and down by operating the adjusting screw d to change the distance l between the contact plate c and the point of action _a1 . It is possible to set the timer.

However, when the contact plate c is deformed by operating the adjustment screw d to a state where it is greatly separated from the point of action _a1 as shown in Fig. 2a, and when it is made smaller as shown in Fig. 2b, the contact terminal b ₁ , c ₁
If we consider the bonding pressure state with , we find that the value is larger in the former case than in the latter case. This is because, although the contact plate c always has an elastic force in the direction of the arrow, the degree of deformation of the contact plate c in FIGS. 2a and 2b is different, resulting in a difference in its own elastic force.

In this way, conventionally, the bonding pressure of the contact terminal differs depending on the setting state, so even if the bimetal a deforms in proportion to the temperature change, an error occurs in the actual timing of opening, making it necessary to maintain strict accuracy. There was a problem that made it difficult.

In view of this, this invention aims to provide an automatic temperature controller that can always maintain high accuracy in opening timing relative to temperature by improving the opening structure of the contact terminal. It is something.

An embodiment of this invention will be described below with reference to FIGS. 3 and 4. 1 in the figure is the base axis,
The end portions of a movable contact plate 2, a fixed contact plate 3, a support plate 4, and a mounting plate 5 are attached to the base shaft 1 at a distance from each other. The movable contact plate 2 and the fixed contact plate 3 each have contact terminals 2a and 3a, and these terminals 2a and 3a are crimped together by the elastic force of the movable contact plate 2. The support plate 4 has an elastic force that allows it to rotate upward, and is bent in the middle into a step shape, with the bent portion as a boundary and the tip end serving as a receiving portion 4a. The end portion of the bimetal 6 is attached by spot welding or the like, and the bimetal 6 faces the receiving portion 4a at a distance. A protrusion 7 is provided at the tip of the bimetal 6, and the tip of the protrusion 7 serves as a point of action 7a, which is opposed to the extending tip of the movable contact plate 2. The mounting plate 5 is provided with a screw seat 5a, and an adjustment screw 8 is screwed into the screw seat 5a, and its tip abuts against the receiving portion 4a of the support plate 4 to receive the elastic force of the support plate 4. Note that 9 and 10 are lead wires connected to the movable contact plate 2 and the fixed contact plate 3.

Next, the effect will be explained. The bimetal 6 deforms in a curved manner using the connection portion with the support plate 4 as a fulcrum in response to changes in ambient temperature. And this bimetal 6
With the deformation, the point of action 7a comes into contact with the movable contact plate 2 and pushes it against the elastic force of the contact plate 2, and this pushing causes the contact terminals 2a and 3a to separate.

Therefore, both contact terminals 2a, 3a with respect to temperature
In order to change the opening timing, the adjusting screw 8 is screwed downward as shown in FIG. 4, for example. By screwing in the adjustment screw 8, the support plate 4 is bent downward about the connection with the base shaft 1 as a fulcrum, and the distance l between the point of action 7a and the movable contact plate 2 changes. In other words, the distance l becomes smaller. Therefore, due to slight deformation of the bimetal 6, the contact terminals 2a and 3a are separated. Conversely, by displacing the adjusting screw 8 upward, the distance l increases, and the separation time can be extended until the bimetal 6 is significantly deformed. In this way, by operating the adjusting screw 8, the opening timing of the contact terminals 2a, 3a can be arbitrarily set according to the temperature.

Now, if we observe the state of the movable and fixed contact plates 2 and 3, no matter what temperature setting, only the distance l changes, and both contact plates 2 and 3 are always in a constant state. will be maintained.
Therefore, the contact terminal 2a is always pressed against the other contact terminal 3a by the elastic force of the movable contact plate 2.
Therefore, the conditions under which the point of action 7a pushes the movable contact plate 2 are always constant regardless of the temperature setting. Therefore, the deformation of the bimetal 6 that is proportional to the temperature change and the opening timing of the contact terminals 2a, 3a reliably correspond, making it possible to achieve extremely high precision temperature control. Furthermore, contact terminals 2a, 3
Since the bonding pressure of a is always constant, the opening operation is stable and the lifespan can be extended, and it is also easy to calculate the timing of opening with respect to temperature.

In the above embodiment, the distance between the bimetal action point and the movable contact plate is changed by advancing and retracting the adjustment screw, but the adjustment screw is not necessarily used; other means may also be used. There is no problem even if you do so.

As explained above, this invention has the practical effect of ensuring that the degree of deformation of the bimetal corresponds to the timing of opening of the contact terminals, thereby enabling highly accurate temperature control at all times.

[Brief explanation of drawings]

Figure 1 is a side view of a conventional automatic temperature controller;
Figures 2a and b are explanatory diagrams for explaining the action of the regulator, Figure 3 is a side view showing an embodiment of the invention, and Figure 4 is an explanatory diagram for explaining the action of the embodiment. It is a diagram. 2...Movable contact plate, 3...Fixed contact plate, 2a,
3a... Contact terminal, 4... Support plate, 6... Bimetal, 7a... Point of action, 8... Adjustment screw (temperature setting mechanism).

Claims (1)

[Scope of utility model registration request] It has a fixed contact plate, a movable contact plate which is elastically joined to the fixed contact plate through a contact terminal and by its own elastic force, and a point of action that is attached to a support plate and faces the movable contact plate, and has a temperature control plate. A bimetal that pushes the movable contact plate at the point of action against the elastic force by a deforming action in response to the change, and a distance between the point of action and the movable contact plate is changed by deforming the support plate. An automatic temperature controller comprising a temperature setting mechanism.