JPS5841696Y2 - thermal responsive switch - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a thermally responsive switch that combines a thermally responsive mechanism that is a combination of a permanent magnet and a temperature-sensitive magnetic material, and a switch.

Conventionally, this type of thermal response mechanism has been used, that is, the fact that the magnetic properties of a temperature-sensitive magnetic material change rapidly at a single point temperature, and this has been combined with a permanent magnet so that it can be attracted and separated. As a result, various types of thermal response mechanisms have been provided that can extract temperature changes as mechanical displacements, and devices that combine these mechanisms with switches to form thermal response switches are also widely used. .

The present invention aims to realize this type of thermally responsive switch with a simple structure, and one embodiment will be described below with reference to the drawings.

FIG. 1 shows a cross-sectional view of an embodiment of the present invention.

In the figure, a temperature-sensitive magnetic body 1 having a Curie point corresponding to the temperature to be detected and a concave surface having an arcuate cross section on its upper surface is fixed to a heat receiving plate 2. a disc-shaped rotating portion 3a having a diameter approximately the same as the diameter of the concave surface;
A permanent magnet 3 consisting of the temperature-sensitive magnetic body 1 side and a knob 3b extending in the opposite direction is pivotally supported by a shaft 4 at the circular center so that it can freely rotate while contacting the recess.

Here, the distance between the end faces of the permanent magnet 3 facing the temperature-sensitive magnetic body 1 is N
The pole is magnetized so that the upper end side of the knob 3b becomes the S pole,
A claw portion 3C is located at a position substantially horizontal to the shaft 4 in the rotating portion 3a.
is formed.

Of course, the magnetization direction may be reversed, and the Curie point is selected to be sufficiently higher than the Curie point of the temperature-sensitive magnetic body 1.

These mechanisms include an insulating case 5 with an opening 5a at the top end.
The knob 3b is housed in such a manner that the upper part of the knob 3b protrudes from the opening 5a so as to be able to rotate by a predetermined angle.

Two electrode plates 6 and 7 are fitted and fixed on the side wall of the case 5, and contacts 5a and 7a are located at positions corresponding to the claw portion 3C, and as the claw portion 3C rotates, the contact 5a , 7a are opened and closed.

That is, the upper electrode plate 6 is made of an elastic material and is movable, and its tip slightly protrudes from the lower electrode plate 7 and engages with the claw portion 3C. When the electrode plate 6 is slightly rotated counterclockwise in the figure, the electrode plate 6 is bent and the contact portion is closed.

Next, the operation of this thermally responsive switch will be explained.

When the temperature of the heat-receiving portion is lower than the temperature at the single point of the temperature-sensitive magnetic body 1, an adsorption force acts between the concave surface of the temperature-sensitive magnetic body 1 and the convex surface of the rotating portion 3a.

FIG. 1 shows a state in which the contacts 6a and 7a are closed, and the movable electrode plate 6 is
The knob 3b is stabilized in the illustrated state by overcoming the elastic force, but of course, if the knob 3b is rotated clockwise as shown by the dashed line in the diagram against this contact attraction force, Since the claw portion 3C also rotates and the movable electrode plate 6 returns as shown by the dashed line in the figure, the contacts 6a and 7a can be opened, and conversely, they can be closed.

Then, while the attraction force is acting, the permanent magnet 3, that is, the contacts 6a, 7a maintain their state unless an external force acts on the knob 3b.

Now, the elastic force of the movable contact plate 6 is determined by the claw portion 3C in a state where almost no adsorption force is acting between the temperature-sensitive magnetic body 1 and the permanent magnet 3, that is, in a state where the temperature-sensitive magnetic body 1 is a paramagnetic body.
The setting is such that a sufficient repulsion force can be obtained to engage the knob 3b and rotate the knob 3b to the position indicated by the dashed line in the figure.

Therefore, when the temperature of the heat-receiving part exceeds the Curie point of the temperature-sensitive magnetic body 1 and changes to paramagnetism, the temperature-sensitive magnetic body 1 and the permanent magnet 3
Since the adsorption force acting between them becomes very small, the knob 3b together with the rotating part 3a is rotated from the position of the solid line to the position of the dashed-dotted line in the figure due to the elastic force of the movable electrode plate 6 in the clockwise direction in the figure. 6a and 7a are separated.

If the temperature of the heat-receiving part continues to be higher than the one point of the temperature-sensitive magnetic body 1, even if the knob 3b is rotated counterclockwise, if you release your hand from the knob 3b, the elastic force of the movable electrode plate 6 will open the contact. Even if the temperature-sensitive magnetic body 1 changes from paramagnetic to ferromagnetic due to the temperature of the heat-receiving part decreasing, the contact will remain closed unless force is applied counterclockwise to the knob 3b. There's nothing wrong with that.

As described above, it can be operated as a thermal response switch that opens the electric circuit when it detects that the temperature of the temperature-detected part has reached a certain value, especially when the temperature is higher than the Curie point of the temperature-sensitive magnetic body 1. Even if the knob 3b is turned to the contact closing side, it will return to the opening side when the hand is released, so there is no risk of overheating and it is safe.

Note that since the permanent magnet 3 is made of a material close to an insulator, there is no risk of electric shock, but it will be safer if an insulating coating is applied to the knob 3b.

FIG. 2 shows the external appearance of the heat-responsive switch shown in FIG. A heater and other electric circuits whose opening and closing should be controlled are connected to the electrode plates 6 and 7 which protrude outside.

Of course, characters such as ON and OFF are attached to the edge of the opening 5a of the case 5 so that the open/closed state of the contact can be determined by the position of the knob 3b.

FIG. 3 shows the shape of another embodiment of the permanent magnet 3, in which a flange 3d closes the opening 5a from the inside of the case to prevent dust from entering the opening 5a of the case 5 in FIG.
is formed integrally with the knob 3b.

In addition, a similar effect can be obtained by holding a cap 8 made of plastic or the like as shown in FIG.
By covering from the top of the cap 8, it prevents dirt from entering and increases safety, and even if magnetic foreign matter adheres through the cap 8, it can be easily removed, and the appearance can be improved by applying an appropriate color. You can also do that.

FIG. 5 shows another embodiment on the temperature-sensitive magnetic body 1 side, in which a rib l-11 is provided in the center of the concave surface of the temperature-sensitive magnetic body 1 across the width direction, so that the movement changes when the permanent magnet 3 rotates. It is something that we try to give.

That is, the distribution of magnetic flux between the concave surface of the temperature-sensitive magnetic body 1 and the convex surface of the rotating part 3a changes near the slit 1a, and therefore, the center line connecting both magnetic poles of the permanent magnet 3 moves across the slit 1a. As the adsorption force increases and the sliding resistance increases, more force than before is required for rotation, which allows confirmation of the contact opening/closing by the response and prevents the contact from being closed by mistake. be able to.

The present invention is not limited to the embodiments described above, and can be further modified in various ways.

That is, in order to increase the heat receiving efficiency of the temperature-sensitive magnetic body 1, a part of the heat-receiving plate 2 is opened, and a part of the temperature-sensitive magnetic body 1 is exposed through this opening and brought into direct contact with the temperature-detected part. The concave surface of the temperature-sensitive magnetic body 1 is made spherical, and the rotating part 3a of the permanent magnet 3 is also made spherical, and furthermore, only the rotating part 3a is made a permanent magnet, and the knob 3b is integrated with other insulating members. You can do it like this.

In addition, as the temperature-sensitive magnetic material 1, other metal elements such as ferrite, etc.
For example, a Fe-Ni-Cr-Co alloy may be used, and since this has a saturation magnetic flux density approximately twice that of a ferrite element, a paramagnetic thin layer may be used on the contact surface with the ferrite permanent magnet 3. By doing so, it is possible to take measures to prevent wear caused by sliding between the two.

As explained above, the thermally responsive switch according to the present invention has a very simple structure and can be manufactured at low cost.
This is an excellent small switch that operates safely and reliably.

[Brief explanation of the drawing]

Fig. 1 shows an embodiment of the present invention in a sectional view, Fig. 2 shows its external appearance in a perspective view, Fig. 3 shows another embodiment of the permanent magnet 3, and Fig. 4 shows a knob portion. FIG. 5 is a diagram showing the shape of the cap to be placed upside down, and FIG. 5 is a diagram showing another embodiment of the temperature-sensitive magnetic material. 1...Temperature-sensitive magnetic material, 2...Heat receiving plate, 3
...Permanent magnet, 5...Case, 6...
...Movable electrode plate, 7...Fixed electrode plate, 8.
·····cap.

Claims (1)

[Scope of utility model registration request] A concave surface with an arcuate cross section is formed on the upper surface side of the temperature-sensitive magnetic material and is fixed to the heat receiving part, and a convex surface that fits into the concave surface is formed on one magnetic pole end of the permanent magnet so that these two surfaces come into contact with each other. In this state, the permanent magnet is rotatably supported, and a knob is provided on the permanent magnet so as to extend on a side opposite to the convex surface, and a claw portion is provided at a position substantially horizontal to the shaft support. A thermal response mechanism is provided in which a movable contact portion and a fixed contact portion having elastic properties are arranged at positions corresponding to the claw portions so as to open and close with the rotation of the claw portions. switch.