JPH0449800Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a temperature-sensitive reed switch used as a variety of temperature control switches.

[Technical background of the invention and its problems] A conventional example of this type of temperature-sensitive reed switch is described in the 10th article.
This will be explained with reference to the figures.

The temperature-sensitive reed switch 20 shown in the figure includes a reed switch 1 configured such that the contact portions of magnetic lead pieces 1a and 1b are normally open, and a reed switch 1 surrounding the outer periphery of the contact portion of the reed switch 1. An annular temperature-sensitive magnetic body (for example, thermal ferrite) 2 is arranged as shown in FIG. Annular permanent magnet (e.g. ferrite magnet) 3a, 3
It is composed of b.

As shown in the figure, the permanent magnets 3a and 3b are respectively magnetized so that the side of the magnetic lead piece 1a of the reed switch 1 is the north pole, and the side of the magnetic lead piece 1b is the south pole. In addition, as shown in FIG. 11, each of the temperature-sensitive magnetic bodies 2 has a saturation magnetic flux density that gradually decreases as the temperature rises, and at a certain temperature (Cuyuri temperature) Tc, it often loses its magnetism and changes to a paramagnetic body. It is a well-known place.

The temperature-sensitive reed switch 20 having the above configuration has a temperature-sensitive magnetic body 2 whose ambient temperature T is lower than the Curie temperature Tc.
has sufficient magnetism, the N pole of the permanent magnet 3b → the temperature-sensitive magnetic body 2 as shown in FIG.
→ S pole of permanent magnet 3a → N pole of permanent magnet 3a → Magnetic lead piece 1a → Magnetic lead piece 1b → Magnetic flux passing through the magnetic path leading to S pole of permanent magnet 3b, and N pole of permanent magnet 3b → Magnetism Since the magnetic flux passing through the magnetic path from the body lead piece 1b to the magnetic lead piece 1a to the S pole of the permanent magnet 3a is canceled out, the magnetic flux passing through the contact portion is small, and as a result, the temperature-sensitive reed switch 20
remains open (OFF).

Next, when the ambient temperature T becomes higher than the Curie temperature Tc and the temperature-sensitive magnetic body 2 becomes paramagnetic, the main magnetic flux passing through the temperature-sensitive magnetic body 2 disappears and the permanent magnet 3
Since the main magnetic flux from b passes through the contact portion of the reed switch 1 in the axial direction and reaches the S pole of the permanent magnet 3a, a magnetic pole is formed at this contact portion, and as a result, the magnetic lead pieces 1a and 1b are It becomes closed (ON) state due to the attractive force of the magnetic pole.

That is, the temperature-sensitive reed switch 20 at this time
As shown in Figure 9, when a magnetic field greater than PI (pull-in ampere-turn) acts on the contact, the contact becomes ON, and when a magnetic field less than DO (drop-out ampere-turn) acts, it becomes OFF. As a result, non-bandwidth operation is performed.

However, the temperature-sensitive reed switch 20 has a problem in that the permanent magnets 3a and 3b must be placed at operating points on both ends of the reed switch 1, respectively, resulting in an increase in overall size.

Furthermore, in order to widen the interval (hysteresis) between DO and PI shown in Fig. 9, the temperature-sensitive magnetic body 2 shown in Fig. 10 was divided into two temperature-sensitive magnetic bodies with different Kuuri points. However, this also has the problem of increasing the overall size.

In addition, in the temperature-sensitive reed switch 20, due to its structure, there is a gap between the end face of the permanent magnet 3a and the magnetic lead piece 1a exposed from the glass tube, and a gap between the end face of the permanent magnet 3b and the magnetic lead piece 1b exposed from the glass tube. The distance (insulation distance) α between the two is short, which poses a problem in terms of withstand voltage.

This is shown in Figure 12 a, b and Figure 13 a, b.
Please refer to for further details.

12a and 12b show a make-type temperature-sensitive reed switch 30 mounted on a printed circuit board 31. FIGS. That is, this temperature-sensitive reed switch 30 has a temperature-sensitive magnetic body 2 arranged around the outer periphery of the contact portion of the reed switch 1, and spacers 32 made of aluminum, for example, are placed on both sides of the temperature-sensitive magnetic body 2.
Permanent magnets 33a, 33 with a, 32b interposed
b.

Both magnetic lead pieces 1a and 1b of the reed switch 1 are passed through the wiring pattern 31a and the printed circuit board 31, and their respective ends are fixed to the back side of the printed circuit board 31 by soldering or the like.

In such a connection structure of the temperature-sensitive reed switch 30, the temperature-sensitive magnetic body 2 or the permanent magnet 33
a and 33b are wiring patterns 3 of other circuits formed on the printed circuit board 31 as shown in FIG. 12b.
1b, and the wiring patterns 31a, 31b
When a voltage is applied between the temperature-sensitive magnetic body 2 and the permanent magnets 33a and 33b, which are generally not insulators, the permanent magnet 33a and the magnetic lead piece 1a or the permanent magnet 33b and the magnetic lead piece 1b A discharge phenomenon occurs between the temperature-sensitive reed switch 30 (insulation distance α), and as a result, the temperature-sensitive reed switch 30 has a breakdown voltage failure and does not operate normally.

Further, FIGS. 13a and 13b show still another conventional example, in which the temperature-sensitive reed switch 4 shown in the same figure is
0, a temperature-sensitive magnetic body 2 is arranged on the outer periphery near the contact part of the reed switch, and this temperature-sensitive magnetic body 2
Permanent magnets 33a and 33b are arranged on both sides of the cylindrical part 41a of the fitting 41, and the outer periphery of these magnets is surrounded by the cylindrical part 41a of the fitting 41.
1b is fixed with bolts 43 of another metal member (hereinafter also referred to as chassis) 42 such as a chassis.

In addition, in the figure, 44a and 44b are the cylindrical portion 41.
Plastic holders 45 are fitted from both sides of a toward the permanent magnets 33a and 33b, respectively.
Numerals a and 45b are vinyl wires connected to the magnetic lead pieces 1a and 1b, respectively.

In such a temperature-sensitive reed switch 40, the insulation distance α is almost the same as in the case described above, and the distance between the chassis and the mounting bracket 41, the mounting bracket 41, the temperature-sensitive magnetic body 2, and the permanent magnets 33a, 33b is
are in contact with each other, so when a voltage is applied between the chassis and the reed switch 1, a voltage is applied between the permanent magnet 33a and the magnetic lead piece 1a, or between the permanent magnet 33b and the magnetic lead piece 1b. A discharge phenomenon occurs, and as in the case of the temperature-sensitive reed switch 30, normal operation does not occur.

[Purpose of the invention] The present invention was made in view of the above circumstances, and is a temperature-sensitive device that can reduce the overall size, easily adjust the operating temperature, and exhibits stable operation. The purpose is to provide a reed switch.

[Summary of the invention] The outline of the invention is a reed switch having two magnetic reed pieces, a permanent magnet arranged around the outer periphery of the contact part of the reed switch, and magnetized in the axial direction of the reed switch. , sandwich this permanent magnet,
and two temperature-sensitive magnetic bodies having different magnetic transformation points arranged so as to surround the reed switch;
A temperature-sensitive reed switch is constructed by comprising the permanent magnet and a metal magnetic yoke disposed around the outer periphery of the temperature-sensitive magnetic body.

[Embodiments of the invention] Examples of the invention will be described in detail below with reference to FIGS. 1 to 3.

In the temperature-sensitive reed switch 10 shown in FIGS. 1 to 3, those having the same functions as the conventional temperature-sensitive reed switch 20 shown in FIG. Omitted.

This temperature-sensitive reed switch 10 differs from the conventional temperature-sensitive reed switch 20 in that the magnetic lead piece 1
A permanent magnet 3c is arranged on the outer periphery of the contact part of a and 1b, and two magnets with different magnetic transformation points are placed on both sides of this permanent magnet 3c.
The temperature-sensitive magnetic bodies 12a and 12b are arranged adjacently and surrounding the reed switch 1, and the outer diameter of the permanent magnet 3c is
The outer diameters of the metal magnetic yoke 4a are made smaller than the outer diameters of the metal magnetic yoke 4a and the cross-sectional ratios of the two are different, thereby forming a cylindrical space 5 between the metal magnetic yoke 4a and the metal magnetic yoke 4a. As shown in FIGS. 2 to 4, the radius of curvature R of the outer periphery of the temperature-sensitive magnetic materials 12a and 12b is
The metal magnetic yokes 4a are formed into an arc shape having a radius of curvature R1 smaller than 2, and the temperature-sensitive magnetic bodies 12a, 12b are formed using the elasticity of the metal magnetic yokes 4a.
The magnetic yokes 4a, 4a are placed in close contact with the outer peripheries of the temperature-sensitive magnetic bodies 12a, 12b by utilizing their elasticity.

As a result, two symmetrical gaps 6a, 6b (distance W/2) are formed on the outer periphery of the temperature-sensitive magnetic bodies 12a, 12b and the permanent magnet, as shown in FIG. There is.

As shown in FIG. 5, the Curie temperature of the temperature-sensitive magnetic body 12a is T1, and the Curie temperature of the temperature-sensitive magnetic body 12b is T2 (T1<T2).

Next, the temperature-sensitive reed switch 10 with the above configuration is
The ON and OFF operations will be explained with reference to FIGS. 6a, b, and c and FIG. 7.

Seriously, when the ambient temperature T of this temperature-sensitive magnetic body 10 is lower than the Curie temperature T1 of the temperature-sensitive magnetic body 12a, as shown in FIG. A magnetic path with low magnetic resistance is formed that passes through the yoke 4a and the temperature-sensitive magnetic material 12b to the S pole, and most of the main magnetic flux from the permanent magnet 3c passes through this magnetic path, and the main magnetic flux is transmitted to the contact portion of the reed switch 1. Since the temperature-sensitive reed switch 10 does not pass through, the temperature-sensitive reed switch 10 remains in the OFF state.

Next, when the ambient temperature T of the temperature-sensitive reed switch 10 becomes higher than the Cuyuri temperature T2, the temperature-sensitive magnetic bodies 12a and 12b become paramagnetic, and together with the existence of the space 5 (if the space 5 is (If it is not provided, the main magnetic flux will pass through the metal magnetic yoke 5, making the operation somewhat unstable.) The magnetic resistance of the above-mentioned magnetic path increases, and as a result, as shown in FIG. 6b, the N of the permanent magnet 3c The main magnetic flux from the pole passes through the magnetic lead piece 1a, the contact part, and the magnetic lead piece 1b, and
It reaches its peak. As a result, magnetic poles are formed at the contact portions of the magnetic reed pieces 1a and 1b, and due to the attraction force, the magnetic reed pieces 1a and 1b are brought into the closed state as shown in the figure, and the temperature-sensitive reed switch 10 is closed.
It becomes ON state.

Next, the ambient temperature T decreases, and in the range T2>T>T1, one temperature-sensitive magnetic material 12b becomes ferromagnetic and the other temperature-sensitive magnetic material 12a becomes paramagnetic, as shown in FIG. 6c. At this time, the main magnetic flux from the N pole of the permanent magnet 3c is the magnetic flux that reaches the S pole via the magnetic lead piece 1a, the contact part, the magnetic lead piece 1b, the temperature-sensitive magnetic body 12b, and the magnetic flux from the metal magnetic yoke 4a to the temperature-sensitive magnetic body 12b. The magnetic flux passes through the magnetic body 12b and reaches the S pole.

As a result, although the magnetic flux passing through the contact portion is reduced, sufficient magnetic flux passes through the contact portion to maintain the ON state, so that the contact portion maintains the ON state.

Eventually, when the ambient temperature becomes T<T1, the temperature-sensitive magnetic body 12a also becomes ferromagnetic, so the main magnetic flux from the permanent magnet 3c passes through a magnetic path as shown in Figure 6a. As a result, the contact portion becomes open. That is, this temperature-sensitive reed switch 10 also performs non-band operation as shown in FIG.

temperature-sensitive magnetic body 12a, temperature-sensitive magnetic body 12
By using a device with various Kiuri points as b, the bandwidth between DO and PI shown in Fig. 9 can be adjusted arbitrarily, and the width between DO and PI is relatively narrow compared to the conventional one. We can provide a temperature-sensitive reed switch that can be expected to have a wide range of applications.

In the operation of the temperature-sensitive reed switch 10 described above, the dimension of the space 5 in the radial direction (direction perpendicular to the protruding direction of the magnetic lead pieces 12a, 12b) is the inner diameter of the permanent magnet 3c to stabilize the operation. The effect is better if the dimension is equal to or larger than the dimension from the bottom to the magnetic lead pieces 1a, 1b.

Turning on such a temperature-sensitive reed switch 10,
In OFF operation, both metal magnetic yokes 4a, 4
Since a is tightly fitted to the outer periphery of the temperature-sensitive magnetic materials 12a and 12b due to its elasticity, the magnetic coupling between them is extremely tight, and there is almost no leakage magnetic flux between them, especially in the OFF state. Good ON/OFF characteristics can be obtained.

Further, a permanent magnet 3c is arranged near the contact part,
By forming a magnetic path different from conventional ones, it is possible to reduce the overall size, and
The distance between the temperature-sensitive magnetic material 12a and the magnetic lead piece 1a exposed from the glass tube, and the distance (insulation distance) β between the temperature-sensitive magnetic material 12b and the magnetic lead piece 1b exposed from the glass tube are compared to the conventional temperature-sensitive lead. It can be made larger than in the case of a switch, and as a result, there is no risk of breakdown voltage failure due to discharge phenomena, and stable ON/OFF operation can be achieved.

Also, gaps 6a and 6b are formed on a part of the outer periphery of the temperature-sensitive reed switch 10.If the gap between the gaps 6a and 6b is W/2, the total becomes W, and this gap W can be set to different dimensions. By making various changes using the metal magnetic yoke 4a, the temperature-sensitive reed switch 10 can be turned on or off.
It becomes possible to finely adjust the OFF characteristics. That is, as shown in FIG. 7, the relationship between the ambient temperature of the temperature-sensitive reed switch 10 and the ON/OFF characteristics changes depending on whether the gap W is large or small.

For example, when the gap W is large, it turns off at temperature Ta1 and turns on at temperature Ta2, as shown in Figure 7, whereas when the gap W is small, Tb
It is OFF when the temperature is 1, and it is ON when the temperature is Tb2. Therefore, by preparing a plurality of types of metal magnetic yokes with different arc lengths and changing the gap W, it is possible to appropriately change the temperature range of the ON/OFF characteristics of the temperature-sensitive reed switch 10.

Furthermore, since the characteristics can be adjusted by changing the dimensions of the space 5, it is also possible to diversify the adjustment based on the relative relationship between this and the gap W described above.

Figures 8a and 8b show a second embodiment of the present invention. In the temperature-sensitive reed switch 10A of the figure, those having the same functions as the above-described temperature-sensitive reed switch 10 are designated by the same reference numerals, and detailed explanation thereof will be omitted.

This temperature-sensitive reed switch 10A differs from the temperature-sensitive reed switch 10 described above in that a cylindrical metal magnetic yoke 4b is used instead of the metal magnetic yoke 4a. In this case, by changing the dimensions of the space 5, the temperature range of the ON and OFF characteristics can be adjusted.

The present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the invention. For example, in the first embodiment described above, two gaps are formed on the outer periphery of the temperature-sensitive reed switch using two metal magnetic yokes. Even if a metal magnetic yoke is used in which a gap is formed at only one location along its length, the same effect can be achieved by setting the gap between the gaps to be the above-mentioned gap W.

Further, it is also possible to implement the same method by dividing the metal magnetic yoke into three or more parts.

Furthermore, even if the temperature-sensitive reed switch is constructed using a plurality of permanent magnets whose total thickness is equivalent to that of the permanent magnet 3c, and the thickness of these permanent magnets is varied, the above-mentioned characteristics will not be maintained. Adjustment is possible.

Furthermore, in the above-mentioned embodiment, a case was explained in which a space is formed by changing the cross-sectional ratio of the permanent magnet and the temperature-sensitive magnetic material, but even if this space is not provided, it is possible to change the set temperature by adjusting only the gap. It can also be done.

[Effects of the invention] According to the invention described in detail above, it is possible to easily reduce the overall size, and moreover, it is possible to adjust the temperature range of non-band operation in various ways, and to achieve stable operation.
It is possible to provide a temperature-sensitive reed switch that exhibits ON/OFF characteristics.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a first embodiment of the temperature-sensitive reed switch of the present invention, Fig. 2 is a front view of the same, Fig. 3 is a side view of the same, and Fig. 4 is a metal magnetic structure in this embodiment. A side view showing the yoke, FIG. 5 is an explanatory diagram showing the Curie temperatures of both temperature-sensitive magnetic materials in the first embodiment, and FIGS. 6 a, b, and c respectively show the temperature-sensitive reed switch of the first embodiment. FIG. 7 is an explanatory diagram showing the relationship between temperature and ON and OFF states due to changes in the plaster in the first embodiment, and FIGS. A cross-sectional view and a side view showing the embodiment, and FIG. 9 shows the strength of the magnetic field and ON/OFF in the temperature-sensitive reed switch.
Fig. 10 is a cross-sectional view showing the conventional temperature-sensitive reed switch, Fig. 11 is a graph showing the change in magnetic properties of the temperature-sensitive magnetic material with respect to temperature change, and Fig. 12a is the conventional temperature-sensitive reed switch. FIG. 12b is a perspective view of the same as above, and FIG. 13a is a sectional view showing how another conventional temperature-sensitive reed switch is attached to a printed circuit board. The sectional view shown in FIG. 13b is a perspective view of the same. 1...Reed switch, 3c...Permanent magnet, 4
a, 4b...Metal magnetic yoke, 6a...Gap 6a, 10, 10A...Temperature-sensitive reed switch, 1
2a, 12b...temperature-sensitive magnetic material.

Claims (1)

[Claims for Utility Model Registration] (1) A reed switch having two magnetic reed pieces, and a permanent magnet arranged around the outer periphery of the contact part of the reed switch and magnetized in the axial direction of the reed switch. , two temperature-sensitive magnetic bodies with different magnetic transformation points arranged to sandwich the permanent magnet and surround the reed switch, and a metal magnetic body arranged around the outer periphery of the permanent magnet and the temperature-sensitive magnetic body. A temperature-sensitive reed switch characterized by having a yoke. (2) The temperature sensing device according to claim 1, wherein the permanent magnet and both temperature sensing magnetic bodies have different cross-sectional ratios, and a space is formed between the outer periphery of the permanent magnet and the metal magnetic yoke. Reed switch. (3) The magnetic metal yoke according to claim 1 or 2 of the utility model registration claim, wherein the metal magnetic yoke is formed in an arc shape, and a hollow part is formed in at least a part of the outer periphery of the temperature-sensitive magnetic body and the permanent magnet. Warm lead switch. (4) The temperature-sensitive reed switch according to claim 1 or 2, wherein the metal magnetic yoke has a cylindrical shape.