JPH02272333A - Thermostat - Google Patents

Abstract

PURPOSE:To prevent the generation of the segregation in m. p. to be generated by mixing by separating and disposing paraffin in series in the axial direction of a working rod via separating members and forming plural pieces of the paraffin as the single material which is different in m. p. CONSTITUTION:The 1st paraffin 14 having the low m. p. melts and the 2nd paraffin 16 having the high m. p. is in a solid state when an atmosphere temp. rises to a T1 region. The lift quantity of the working rod 21 is rapidly risen like (a) by the liquid expansion of the 1st paraffin 14 and the solid expansion of the 2nd paraffin 16. The lift quantity attains L1 at the temp. T1. The lift quantity is increased slightly like (b) by the solid expansion of the 2nd paraffin 16 when the temp. rises to the intermediate temp. region of T1 to T2. The 2nd paraffin 16 melts and the lift quantity is rapidly increased like (c) by the liquid expansion thereof when the temp. rises further to the T2 region. The lift quantity L2 is attained at T2. The lift quantity decreases when the temp. falls from T2 to T1.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to thermostats.

[Prior art]

As shown in Fig. 2, conventional thermostats used to operate temperature detection switching valves and other parts depending on the ambient temperature include a case 1 with one end open, filled with wax 2 whose volume expands and contracts depending on temperature changes. A guide 4 is caulked and fixed to the open end side with a rubber diaphragm 3 interposed therebetween, and a semi-fluid 5 is filled into the guide 4 on the side facing the wax 2 via the diaphragm 3.
A piston 6, a plate 7, and an actuating rod 8 are each slidably fitted at the outer end of this semi-fluid, and when the ambient temperature rises, the wax 2 thermally expands and the diaphragm 3 is bent upward, the semi-fluid body 5 is pushed upward, and the actuating rod 8 is moved to protrude through the piston 6 and plate 7. When the ambient temperature drops, the wax 2 contracts. For example, Japanese Utility Model Application Laid-open No. 59-56537 discloses a device in which the actuating rod 8, the plate 7, the semi-fluid body 5, and the piston 6 are retracted by the pushing-in direction load acting on the actuating rod 8. .

In such a thermostat, the wax 2 filled in the case 1 has conventionally been a mixture of two types of paraffins having different melting points evenly mixed together.

[Problem to be solved by the invention]

As in the conventional wax, when two types of paraffins with different melting points are uniformly mixed, when the mixture is uniform, the lift f of the volume change with respect to the temperature change is
fl becomes almost linear as shown by solid line A in Fig. 4,
When the temperature is T, the lift amount is LI, and when the temperature is T2, the lift amount is L2. However, when each paraffin repeatedly melts and solidifies during long-term use, melting point segregation occurs, the mixing state is disrupted, and the temperature-lift ffl characteristic changes as shown by the dotted line B in Figure 4, for example. Lift amount L2 at T2
There is a concern that the setting characteristics may not be obtained satisfactorily, and that this may lead to incorrect operation of the parts.

Therefore, the present invention uses the several types of paraffins to be used as a single agent without mixing them, eliminates the occurrence of melting point segregation caused by mixing as described above, and maintains the set temperature-lift i characteristic for long-term use. The purpose of this project is to propose a thermostat that does not change even when the temperature changes.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention is characterized in that the storage chamber of the heat-sensitive section is filled with paraffin, and the volume of the paraffin is expanded and stored due to changes in the ambient temperature to move the operating rod forward and backward. Paraffin is separated and arranged in series with respect to the axial direction of the operating rod via a separation member, and the separated plurality of paraffins are made into a single agent each having a different melting point. be.

[Operations and Effects of the Present Invention] When the ambient temperature is in a predetermined low temperature range, paraffin having a low melting point melts and the operating rod advances to a predetermined rift I-ML due to the liquid expansion. Next, when the ambient temperature reaches a predetermined high temperature range, the paraffin having a high melting point melts and the liquid expansion further increases the reflit of the actuating rod. Furthermore, when the ambient temperature falls, paraffin with a high melting point is first solidified, followed by paraffin with a low melting point, and the actuating rod moves in and out in the opposite manner to the above.

Such melting and solidification are repeated during long-term use, but since each paraffin is a single agent, melting point segregation does not occur as in the conventional case, and the volume change with temperature of paraffin is It does not change even after long-term use.
Therefore, the lift characteristics of the actuating rod with respect to the set temperature are satisfactorily maintained over a long period of time, and the reliability of the thermostat is increased. Further, by combining paraffins of different melting points as desired or by changing the amount of paraffin added, the temperature-lift IT characteristics can be easily set to various desired values.

〔Example〕

Next, an embodiment of the present invention shown in FIG. 1 will be described.

Reference numeral 10 denotes a cylindrical guide, and a plug 12 is fitted into the bottom of the storage chamber 11 and sealed by a seal ring 13.
It is caulked and fixed by 0a. The lower half of the guide 10 is a heat-sensitive part 10b, and inside the storage chamber ll,
A first paraffin 14 is located at the bottom and expands and contracts in volume due to temperature changes, and is filled with the first paraffin 14. A first piston 15 is placed at the top of the paraffin 14, which expands and contracts in volume due to temperature changes. , a second paraffin 16 to be stored is filled, and a second piston 17 is placed above it.

The storage chamber 11 in the upper half of the guide 10 is filled with a semi-fluid 18 located above the second piston 17, and a third piston 19 is inserted above the second piston 17.
A plate 20 is placed above the plate 20, and an operating rod 21 is placed above the plate 20. The first paraffin 14 and the second paraffin 16 are single agent paraffins having different melting points. For example, the first paraffin 14 has a melting point at the temperature T1 in FIG. 3, and the second paraffin 16 The melting points of are set at the temperature T2 in FIG. 3G, respectively. The first piston 15 is made of a rubber material, and has both paraffin 1
4.16 is slidably inserted into the storage chamber 11 with a suitable seal for separation.

The second piston 17 is made of a rubber material and is slidably inserted into the storage chamber 11 with an appropriate sealing property to separate the second paraffin 16 and the semi-fluid 18. The semi-fluid body 18 is made of a material having suitable lubricity in order to reduce the sliding resistance of the second piston 17 and the third piston 19. The third piston 19 is made of a rubber material and seals the storage chamber 1 with appropriate sealing properties to prevent the filled semi-fluid 18 from leaking outside.
1 is slidably inserted. Said plate 20
The actuating rod 21 is slidably inserted into the storage chamber 11.

22 is a stopper ring provided on the actuation rod 21.

[Effect of the embodiment]

External heat in the heat sensitive part 10b is transmitted to the first and second paraffins 14.16 through the cylindrical guide 10, and as the ambient temperature rises and falls, the respective paraffins 14.16
expands and contracts in volume, the third piston 19 slides via the first piston 15, second piston 17, and semi-fluid 18, and the actuating rod 21 moves forward and backward.

An example of the relationship between the thermal expansion of the paraffin 14 and 16 and the lift amount of the operating rod will be explained with reference to FIG.

When the ambient temperature rises to the region T in FIG. 3, the first paraffin 14 with a low melting point melts, and the second paraffin 16 with a high melting point remains in a solid state. Therefore, due to the liquid expansion of the first paraffin 14 and the solid expansion of the second paraffin 16, the lift amount of the actuating rod 21 increases rapidly as shown in A, and the lift amount increases at the temperature T1. Next, when the ambient temperature reaches an intermediate temperature range between T1 and T2, the lift amount increases slightly due to solid expansion of the second paraffin 16. When the temperature further rises to the T2 region, the second paraffin 16 melts, and due to its liquid expansion, the lift amount further increases rapidly as shown in C, and at the temperature T2, the lift amount becomes L2. Further, when the temperature decreases from the T2 region to the T region, the temperature-ref I-fi! The amount of lift decreases in the characteristic state.

Even if such melting and solidification of paraffin is repeated due to long-term use, since each paraffin 14 and 16 is a single agent, melting point segregation will not occur and the temperature-lift i characteristics will change. The set characteristics can be maintained for a long period of time without any problems.

The types and amounts of the paraffins 14 and 16 are selected depending on the desired temperature-lift characteristics.

Further, both the paraffins 14 and 16 are connected to the first piston 15.
However, the separation may be performed using a diaphragm like the conventional one described above.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing an embodiment of the present invention, FIG. 2 is a side sectional view showing a conventional structure, FIG. 3 is a temperature-lift ffl characteristic diagram according to the present invention, and FIG. 4 is a temperature-lift characteristic diagram according to the conventional structure. It is a lift ffl characteristic diagram. 10...Guide, 10b...Heat-sensitive part, 11...
・Storage room, 14.16 ...Paraffin, 15...
・Piston, 21...Operating rod Fig. 1 Fig. 2

Claims (1)

[Claims] In the storage chamber of the heat sensitive part, the storage chamber of the heat sensitive part is filled with paraffin, and the operating rod is moved forward and backward by the expansion and contraction of the volume of the paraffin due to changes in ambient temperature, and the paraffin is transferred to the axis of the operating rod through a separating member. 1. A thermostat characterized in that a plurality of paraffins are separated and arranged in series in a direction, and each of the separated paraffins is made into a single agent having a different melting point.