JPS6020264Y2 - thermal response device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of an automatic return type thermal response device among thermal response devices using a combination of a temperature-sensitive magnetic material and a permanent magnet.

Magnetic materials such as ferrite are called temperature-sensitive magnetic materials because their magnetic properties change at a single point temperature, and a thermally responsive device that mechanically displaces a permanent magnet in response to this magnetic change is used as a temperature detection means. Various types are available, and the vertical cross-sectional structure of one example is shown in FIG.

In the figure, this device has a temperature-sensitive magnetic body 2 fixed to a heat-receiving plate 1 with a single Curie point corresponding to the temperature to be detected, and a permanent magnet 3 having a single Curie point sufficiently higher than the temperature to be detected is attached to the temperature-sensitive magnetic body 2. The movable plate 5, which is biased by a coil spring 4 in a direction away from the temperature-sensitive magnetic body 2, is fixed and opposed to the movable plate 5.

Reference numeral 6 denotes an operating rod connected to the movable plate 5 in order to transmit the displacement of the magnet 3 to the outside of the case 7.

Furthermore, in order to make this device an automatic return type, the biasing force of the coil spring 4 and the distance between the magnets 3 are set as follows.

In other words, the magnet 3 is separated from the temperature-sensitive magnetic body 2 only when the temperature-sensitive magnetic body 2 is heated to its single point temperature and becomes paramagnetic, and the temperature decreases and the temperature-sensitive magnetic body 2 returns to its original ferromagnetic state. When this occurs, the magnet 3 is set to automatically return to the position where it attracts the temperature-sensitive magnetic body 2 due to the magnetic attraction force.

By the way, when the magnet 3 is separated, the movable plate 5 is in contact with the bottom of the case 7, so that the biasing force of the coil spring 4 is greatest when the magnet 3 is separated from the temperature-sensitive magnetic body 2, but when it is in the separated state The biasing force is not zero, but is applied to an extent that can prevent the movable plate 5 from vibrating due to external shocks or the like.

For this reason, the temperature-sensitive magnetic body 2 decreases after the magnet 3 is separated.
The initial magnetic attraction force that acts when the magnet 3 exhibits ferromagnetism and the return operation of the magnet 3 begins is the smallest because the distance between the magnet 3 and the temperature-sensitive magnetic material 2 is the largest, whereas Since the biasing force acts to reduce this initial magnetic attraction force, the initial driving force for the automatic return operation is very small.

Of course, when the magnet 3 begins to approach the temperature-sensitive magnetic body 2, the magnetic attraction force increases rapidly, overcoming the biasing force of the coil spring 4, which only increases monotonically even when the separation distance becomes short, and the magnet 3
instantly returns to the position where it attracts the temperature-sensitive magnetic body 2.

From this, it can be said that the return operation speed during automatic return depends on the magnitude of the initial driving force.

In view of these points, the present invention aims to provide an automatic return type thermal response device that increases the initial driving force at the time of automatic return and improves the return operation speed.

This invention is based on a permanent magnet that is separated from a temperature-sensitive magnetic material.
When the temperature drops, a magnetic attraction force is applied that is independent of the separation distance from the temperature-sensitive magnetic material, and an example thereof will be described below.

FIGS. 2 and 3 respectively show a first embodiment of the present invention in longitudinal section when the permanent magnet is attracted and when it is separated.

In the figure, a temperature-sensitive magnetic body 2 having a single point corresponding to the temperature to be detected is fixed to a heat-receiving plate 1 that also serves as a lid of a case 7, and a protrusion 21 is integrally attached to the center of the lower surface of this temperature-sensitive magnetic body 2. Molded.

Further, a permanent magnet 3 with a single point sufficiently higher than the temperature to be detected is fixed to the movable plate 5, which is biased away from the temperature-sensitive magnetic body 2 by the coil spring 4, with the magnetic pole axis aligned with the moving direction. 3 has a through hole 31 in the center in the direction of movement.
When the protruding piece 21 is attracted to the temperature-sensitive magnetic body 2 by forming a
It is designed to loosely fit into 1.

The biasing force of the coil spring 4 and the position of the magnet 3 when separated from the temperature-sensitive magnetic body 2 are similar to those described above. The setting is such that the magnet 3 can automatically return to the position where it attracts the temperature-sensitive magnetic body 2 when the temperature drops below the Curie point.

Further, the thickness of the magnet 3 in the moving direction is larger than the moving distance thereof, and the length of the protruding piece 21 is made almost equal to the thickness of the magnet 3, so that even when the magnet 3 is separated, the protruding piece 21 remains in the through hole 31. The lower part of the frame is inserted into the frame.

With the above configuration, in a low temperature range where the temperature of the temperature-sensitive magnetic body 2 is lower than one point, as shown in FIG. and the lower end of the magnet 3 are substantially in the same plane.

On the other hand, when the temperature of the temperature-sensitive magnetic body 2 and the protruding piece 21 exceeds that point, both exhibit paramagnetism and their magnetic attraction disappears, and the coil spring 4 causes the magnet 3 to is displaced downward, and a portion of the protruding piece 21 is fitted into the through hole 31.

When the temperature of the temperature-sensitive magnetic body 2 and the protruding piece 21 decreases and exhibits the original ferromagnetism, a magnetic attraction force acts between the magnetic pole surface of the magnet 3 and the main surface of the temperature-sensitive magnetic body 2, and the magnet 3 A magnetic attraction force that pulls the protruding piece 21 into the through hole 31 also acts between the protruding piece 21 and the protruding piece 21 .

The former attractive force is small at the start of return and rapidly increases as the magnet 3 approaches the temperature-sensitive magnetic body 2.

Although the latter attractive force is not so large, it is almost constant regardless of the positional relationship of the magnet 3, and the initial driving force at the start of return can be increased, so the automatic return operation is performed at a higher speed than before. It will be done.

In addition, since the temperature changes of the temperature-sensitive magnetic body 2 and the protruding piece 21 can be considered to be substantially simultaneous, the stability when the magnet 3 is in the separated state is not impaired.

FIG. 4 shows a second embodiment of the present invention, in which a magnetic material having a single Curie point sufficiently higher than the temperature to be detected is added to the structure of the previous embodiment so as to close the through hole 31 on the lower surface of the magnet 3. A yoke piece 8 is provided.

In this way, since an attractive force also acts between the yoke piece 8 and the protruding piece 21, it is possible to increase the magnetic attractive force that acts between the protruding piece 21 and the magnet 3, that is, the initial driving force at the time of automatic return. .

FIG. 5 is a modification of FIG. 4, in which the temperature-sensitive magnetic body 2 is held by covering its lower main surface with a non-magnetic thin plate 9, so that the magnet 3
The structure prevents damage to each other due to collision with the temperature-sensitive magnetic body 2, and the protruding piece 21 is lengthened by the thickness of the thin plate 9.
and the yoke piece 8 are in close contact with each other.

FIGS. 6 and 7 show a fourth embodiment of the present invention when the magnet 3 is attracted and separated, respectively.

In this example, as in FIG. 5, in addition to covering and holding the main surface of the temperature-sensitive magnetic body 2 with a non-magnetic thin plate 9, the magnet 3 is fixed to the inner bottom surface of a dish-shaped yoke 10 having a recess slightly deeper than its thickness. By doing this, a larger initial driving force can be obtained during automatic return than in the previous embodiment, and the length of the protrusion 21 is the total dimension of the depth of the recess of the yoke 10 and the thickness of the thin plate 9. .

FIGS. 8 and 9 respectively show the fifth embodiment of the present invention when the magnet 3 is attracted and separated.

In this example, as in FIG. 5, the main surface of the temperature-sensitive magnetic body 2 is held by covering it with a non-magnetic thin plate 9, but the protruding piece 2 is not provided with a yoke piece.
1 is shorter than the total length of the thickness t of the magnet 3 in the magnetic pole direction and the moving distance d, but longer than the larger one of the thickness t1 and the moving distance d.

As a result, when the temperature of the temperature-sensitive magnetic body 2 is less than one point, the magnet 3 is in a position where it attracts the temperature-sensitive magnetic body 2, as shown in FIG. There is no magnetic attraction force acting between the protruding piece 21 and the magnet 3 in the direction of movement.

When the temperature of the temperature-sensitive magnetic body 2 and the protruding piece 21 rises and reaches a single point, the magnetic attraction force acting on the magnet 3 disappears, and due to the biasing force of the coil spring 4, as shown in FIG. , the magnet 3 is separated from the temperature-sensitive magnetic body 2 and a portion of the protrusion 21 is in the through hole 31 of the magnet 3.

Then, while the temperature of the temperature-sensitive magnetic body 2 and the protruding piece 21 exceeds that point, the magnet 3 is stabilized by the remaining biasing force of the coil spring 4.

After that, when the temperature decreases to below the Curie point, both the temperature-sensitive magnetic body 2 and the protrusion 21 exhibit ferromagnetism, and a magnetic attraction force acts between them and the magnet 3.

Of these, the attractive force that acts between the protrusion 21 and the magnet 3 and tries to pull the protrusion 21 into the through hole 31 exists only until the lower end surface of the protrusion 21 is almost aligned with the lower surface of the magnet 3. When the lower end of the protruding piece 21 protrudes from the through hole 31, no suction force is applied.

In this way, during the return operation of the magnets 3, a nearly constant attractive force that is not affected by the separation distance is applied only while the initial separation distance between the magnets 3 is large, increasing the initial driving force and speeding up the return operation. be able to.

Of course, the magnitude of the attractive force acting between the protruding piece 21 and the magnet 3 can be arbitrarily set by changing the size of the cross-sectional area of the protruding piece 21, making it easy to balance the driving force during operation and return operation. can be taken.

FIGS. 10 and 11 show a sixth embodiment of the present invention when the magnet 3 is attracted and separated, respectively.

The difference from the fifth embodiment described above is that the temperature-sensitive magnetic body 2 is integrally provided with two protruding pieces 21 and 21' having a length that protrudes from the movable piece 5 when the magnet 3 is attracted. 3 is also provided with two through holes 31.31', and the movable plate 5 is also provided with two through holes 51.51'.

According to such a structure, the initial driving force can be further increased, and the two projecting pieces 21 and 21' also serve as guides for the magnet 3.

FIG. 12 shows a seventh embodiment of the present invention when the magnet 3 is separated.

This example can be considered as a combination of the embodiments shown in FIGS. 6 and 8, in which the magnet 3 is fixed to a dish-shaped yoke 10 having a slightly deeper recess, A through hole 101 is also provided at the bottom of the yoke 10, and the yoke 10 also increases the attractive force between the protrusion 21 and the magnet 3, increasing the initial driving force during automatic return. .

In each of the embodiments, the projecting piece 21 is integrally molded with the same material as the temperature-sensitive magnetic body 2, but it is also possible to integrally fix a magnetic material with a single Curie point that is substantially the same as the temperature-sensitive magnetic body 2. It's okay.

As explained above, according to the present invention, the magnetic attraction force at the initial stage of automatic return operation, that is, the initial driving force, is increased to increase the return operation at high speed without impairing the stability of the permanent magnet in the separated state. In particular, since a nearly constant magnetic attraction force can be added only while the distance between the magnets is large, it is easy to balance the initial driving force of the operating rod during thermal response operation and return operation. A thermally responsive device that can directly and reliably drive a switch mechanism or a motion conversion mechanism can be provided.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional structural diagram of an example of a conventional thermally responsive device;
3 and 3 are vertical cross-sectional structural diagrams showing the first embodiment of the present invention when the magnet is attracted and separated, respectively. Hereinafter, FIG. 4 is the second embodiment, and FIG. 5 is the third embodiment. Example 6
7 and 7 are for the fourth embodiment, and FIGS. 8 and 9 are for the fifth embodiment.
10 and 11 are the sixth embodiment and the first embodiment.
FIG. 2 shows the seventh embodiment when the magnet is attracted and separated, respectively. In the figure, 1 is a heat receiving plate, 2 is a temperature-sensitive magnetic material, 3 is a permanent magnet, 4 is a coil spring, 5 is a movable plate, 6 is an operating rod, 7 is a case, 8
is a yoke piece, 9 is a non-magnetic thin plate, 10 is a yoke, 21, 2
1' is a protrusion.

Claims (1)

[Claims for Utility Model Registration] 1. One magnetic pole is opposed to a temperature-sensitive magnetic body having a predetermined single point fixed to a heat-receiving plate, and a permanent magnet is urged in a direction away from the temperature-sensitive magnetic body by a spring member. The permanent magnet is provided with an automatic return mechanism having a thermal response mechanism configured to separate from the temperature-sensitive magnetic body when the temperature of the temperature-sensitive magnetic body exceeds the Curie point, and to attract each other when the temperature of the temperature-sensitive magnetic body falls below the Curie point. In the thermo-responsive device, at least one through hole is provided in the permanent magnet in the direction of movement thereof, and the temperature-sensitive magnetic body corresponding to the through-hole has a curve substantially the same as the temperature-sensitive magnetic body itself or the single point of Curie. 1. A thermally responsive device, characterized in that a protruding piece made of a magnetic material having one point is provided so as to loosely fit into the through hole when the magnet is attracted. 2. The thermal response device according to claim 1, wherein the length of the projection is substantially the same as the thickness t of the permanent magnet in the magnetic pole direction, which is greater than the moving distance d of the permanent magnet. Device. 3 The length of the protruding piece is the thickness t of the permanent magnet in the magnetic pole direction.
and its movement distance d, and the thickness t
The thermal response device according to claim 1, wherein the thermal response device is longer than the larger one of the moving distances d.