Thermoelement

Abstract

To provide a thermoelement that reduces operation defects by a mechanical mechanism without use a complicated electric control mechanism, and has a piston caused to protrude and sink as a volume expansion body volumetrically expands.SOLUTION: A thermoelement 100 comprises: a volumetric expansion body 8 which is contained in a container 9, and volumetrically expands and contracts with an ambient temperature change; a first piston 4 which operates as the volumetric expansion body volumetrically varies with the ambient temperature change of the container; a second piston 10 which differs in diameter from the first piston, and operates as the volumetric expansion body volumetrically varies with the ambient temperature change of the container; a first sealing member 7 which is arranged at one end of the container and has a first through hole; and a second sealing member 11 which is arranged at the other end of the container and has a second through hole with a diameter different from that of the first through hole, wherein the first piston slidably penetrates the first sealing member, the second piston slidably penetrates the second sealing member, and tips of the first piston and the second piston come into direct or indirect contact with each other in the container.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a thermoelement, and more particularly to a thermoelement used in a thermostat device or the like.

Background Art

[0002] Conventionally, a thermostat device (also referred to as a thermo actuator) that opens and closes a valve of a cooling device such as an automobile has been used, which incorporates a thermal expansion body that expands and contracts due to a temperature change of a detected object, and includes a piston that operates due to a volume change of the thermal expansion body.

[0003] In an extremely low temperature environment such as in North America, in a normal exhaust heat recovery device, the heat of exhaust gas generated at the start of an engine of an automobile or the like is taken away by a heat exchanger, moisture contained in the exhaust gas freezes the inside of the muffler by outside air, and the exhaust gas cannot be properly discharged.

[0004] As such a countermeasure, for example, an electric thermo actuator such as that of Patent Document 1 is used.

[0005] The conventional electric thermo actuator structure has a mechanism in which a heater is installed inside the thermoelement, and in an extremely low temperature environment, the wax, which is a thermal expansion body inside the thermoelement, is forcibly melted by energizing the heater, and the piston is pushed up and operated by expanding the volume of the wax.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, in the mechanism of Patent Document 1 described above, when the heater was energized, the heat of the heater did not transfer to the wax in the housing cup due to the balance of thermal conductivity but escaped to the metal cup part, and the desired operation could not be obtained.

[0008] Therefore, the present invention was devised to solve the above problems, and its object is to reduce malfunctions with a mechanical mechanism without using a complex electric control mechanism, and to provide a thermo-element in which the degree of freedom of the protrusion and retraction amount is improved by causing the piston to protrude into and retract from the housing cup according to the degree of volume expansion of the volume expansion body.

Means for Solving the Problems

[0009] The thermo-element according to the first invention is a thermo-element, comprising a container, a volume expansion body housed in the container that expands and contracts in volume due to a change in ambient temperature, a first piston that operates due to a change in the volume of the volume expansion body caused by a change in the ambient temperature of the container, a second piston having a different diameter from the first piston and operating due to a change in the volume of the volume expansion body caused by a change in the ambient temperature of the container, a first sealing member disposed at one end of the container and having a first through-hole, and a second sealing member disposed at the other end of the container and having a second through-hole with a different diameter from the first through-hole, wherein the first piston slidably penetrates the first sealing member, the second piston slidably penetrates the second sealing member, and the tips of the first piston and the second piston are configured to be in direct or indirect contact with each other inside the container.

[0010] The thermo-element according to the second invention is, in the first invention, configured such that a first biasing force by a first biasing member and a second biasing force by a second biasing member are applied to the first piston and the second piston in the retracting (returning) direction, and the magnitude of the first biasing force is configured to be greater than the second biasing force.

[0011] The thermo-element according to the third invention is characterized in that, in the second invention, the relationship between the first biasing force and the second biasing force is configured to satisfy the following relational expression (1).

Number

[0012] The thermo-element according to the fourth invention is characterized in that, in the third invention, it has a locking structure that stops the first piston at a predetermined amount of protrusion and retraction even when the ambient temperature rises.

[0013] The thermo-element according to the fifth invention is characterized in that, in the fourth invention, a stopper is configured on the first piston so that the first piston does not enter the container by more than a predetermined value.

[0014] The thermo-element according to the sixth invention is characterized in that, in the fifth invention, the first sealing member and the second sealing member integrally form a sealing member, and the first piston and the second piston are configured to be in direct or indirect contact within the through-hole of the sealing member.

[0015] The thermo-element according to the seventh invention is characterized in that, in the fifth or sixth invention, the second piston has a cover provided with a stopper mechanism so that the second piston does not dive in by more than a predetermined amount of protrusion and retraction.

[0016] The thermo-element according to the eighth invention is characterized in that, in the fifth or sixth invention, the second piston is provided with a stopper mechanism so that the second piston does not dive in by more than a predetermined amount of protrusion and retraction.

[0017] The thermo-element according to the ninth invention is characterized in that, in the fifth or sixth invention, it has a lid that moves integrally with the container on the first piston side, and the stopper and the lid are configured such that the first biasing member is locked thereto.

Advantages of the Invention

[0018] According to the first to ninth inventions, without using a complicated electric control mechanism, it is possible to reduce malfunctions with a mechanical mechanism and realize a thermoelement with improved freedom of the protrusion / retraction amount by causing a piston to protrude into and retract from a cup according to the degree of volume expansion of the volume expansion body.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Embodiments for Carrying Out the Invention

[0020] Hereinafter, the thermoelement according to the embodiment of the present invention will be described in detail with reference to the drawings.

[0021] The thermo-element of this embodiment includes a container (housing cup), a volume expansion body that is housed in the container and expands and contracts in volume due to changes in ambient temperature, a first piston that operates based on the volume change of the volume expansion body due to changes in the ambient temperature of the container, a second piston that has a different diameter from the first piston and operates based on the volume change of the volume expansion body due to changes in the ambient temperature of the container, a first sealing member disposed at one end of the container and having a first through-hole, and a second sealing member disposed at the other end of the container and having a second through-hole with a different diameter from the first through-hole. The first piston penetrates the first sealing member slidably, the second piston penetrates the second sealing member slidably, and the tips of the first piston and the second piston are configured to contact directly or indirectly within the container. Thereby, without using a complex electric control mechanism, it is possible to reduce malfunctions with a mechanical mechanism and realize a thermo-element in which the piston protrudes and retracts as the volume of the volume expansion body expands.

[0022] <Configuration of Thermo-Element> With reference to FIG. 1, the configuration of the thermo-element 100 according to an embodiment of the present invention will be described. FIG. 1 is a cross-sectional view showing the configuration of the thermo-element 100 according to an embodiment of the present invention, and shows the configuration of a packing type thermo-element.

[0023] As shown in FIG. 1, the thermo-element 100 according to an embodiment of the present invention includes a spring (low load) 1, a spring (high load) 2, a lid 3, a piston (large diameter) 4, a cover 5, a seal (backup ring) 6, a packing (large diameter) 7, a volume expansion body 8, a housing cup 9, a piston (small diameter) 10, a packing (small diameter) 11, a seal (backup ring) 12, and a cover 13.

[0024] <Explanation of the Configuration of the Thermo-Element> The thermo-element 100 uses pistons (large diameter) 4 and pistons (small diameter) 10 with different diameters, a high-load spring 2, a low-load spring 1, and a housing cup 9 that penetrates up and down. It autonomously controls the pistons 4 and 10 according to changes in the ambient temperature, and in combination with various locking structures, improves the degree of freedom of change in the desired protrusion and retraction amount.

[0025] Spring 1 is a low-load spring that generates a biasing force. Spring 1 is locked to the housing cup 9. Spring 1 constitutes the second biasing member.

[0026] Spring 2 is a high-load spring that is locked to the flange of the piston 4 and the lid 3. Spring 2 constitutes the first biasing member.

[0027] The lid 3 functions as a stopper for the piston 4.

[0028] The piston 4 is a stainless steel piston rod that can protrude and retract freely, and constitutes a large-diameter piston as the first piston.

[0029] The cover 5 is a cover that serves as a lid for the housing cup 9.

[0030] The seal 6 is a backup ring.

[0031] The packing 7 is a rubber seal packing (sealing member) for the piston 4. The packing 7 constitutes the first sealing member.

[0032] The volume expansion body 8 expands and contracts in volume due to changes in the ambient temperature enclosed in the housing cup 9. The volume expansion body 8 changes the volume of the housing cup 9 according to changes in the ambient temperature to operate the piston (large diameter) 4 or / and the piston (small diameter) 10. As the volume expansion body 8, for example, it is a wax such as paraffin wax. Hereinafter, in this embodiment, an example using wax as the volume expansion body 8 will be described.

[0033] The housing cup 9 is a container made of a metal such as brass in which a volume expander (e.g., wax) 8 is enclosed.

[0034] The piston 10 is a retractable stainless steel piston rod or the like, and constitutes a small-diameter piston as a second piston having a different diameter from the piston 4.

[0035] The packing 11 is a rubber seal packing (sealing member) of the piston 10. The packing 11 constitutes a second sealing member.

[0036] The seal 12 is a backup ring.

[0037] The cover 13 is a lid that serves as a lid on the piston 10 side of the housing cup 9.

[0038] The pistons 4 and 10 are configured such that their tips are in direct or indirect contact with each other, and as the temperature around the thermo element 100 rises, the wax 8 in the housing cup 9 expands, causing the pistons 4 and 10 to operate autonomously, and the piston 4 protrudes from the housing cup 9. Of course, the wax enclosed in the housing cup 9 is not limited to paraffin wax, and any substance having a predetermined thermal expansion characteristic with a relatively large volume change, such as micro wax, is applicable to the present invention.

[0039] Fig. 2(a) is a diagram for explaining the operation image of the thermoelement in the ambient temperature change of Fig. 1, and Fig. 2(b) is an explanatory diagram of the state of Fig. 2(a). Fig. 3 is a characteristic diagram showing the relationship between the temperature and the protrusion / retraction amount of the thermoelement in Fig. 2(a). Fig. 4 is a characteristic diagram showing the relationship between the temperature of the thermoelement in Fig. 2(a), the wax volume, and the protrusion / retraction amount. Here, the protrusion / retraction amount refers to the protrusion / retraction length by which the thermoelement moves in the protrusion direction (the protruding direction) or the retraction direction (the returning direction) from the initial position of the tip of the thermoelement. This protrusion / retraction amount is determined by the location where the thermoelement 100 is mounted, and the protrusion / retraction amount of the determined value is referred to as the predetermined protrusion / retraction amount. Also, the value of the operating range of the piston 4 or the piston 10 is determined, and the determined value is referred to as the predetermined value. The configuration is such that the piston 4 or the piston 10 cannot operate when it exceeds the predetermined value.

[0040] Hereinafter, with reference to Figs. 2(a)(b), 3, and 4, the overall operation image of the thermoelement according to the embodiment of the present invention will be described.

[0041] As shown in Fig. 2(a), when the ambient fluid temperature changes from the low temperature range to the high temperature range, the state of the wax changes. In the temperature ranges of A - B °C, B - C °C, at C °C, C - D °C, at D °C, D - E °C, and when it is E °C or higher, as shown in Fig. 2(b), in the temperature range of A - B °C, the wax is solid and the volume is the smallest. In the temperature range of B - C °C, the wax is partially melted and the volume is small. At C °C, the wax is partially melted and the volume is medium. In the temperature range of C - D °C, the wax is partially melted and the volume is medium. At D °C, the wax is partially melted and the volume is medium. In the temperature range of D - E °C, the wax is partially melted and the volume is large. When it is E °C or higher, the wax is liquid and the volume is the largest.

[0042] In a general thermoelement with one piston, as shown in Fig. 4, as the temperature rises, the wax volume expands, and as the temperature drops, the wax volume shrinks, so it shows a monotonically increasing (decreasing) change in the protrusion / retraction amount. In Fig. 4, the vertical axis is the wax volume (mm 3 ) and the horizontal axis is the temperature (°C).

[0043] In the case of a general piston with one thermoelement, for example, if the protrusion / retraction length Q1 is at the initial value and the monotonically increasing (decreasing) protrusion / retraction lengths are Q2, Q3, Q4, Q5, then the protrusion / retraction lengths Q1, Q2, Q3, Q4, Q5 show a monotonically increasing (decreasing) change in the protrusion / retraction amount such that as the temperature rises, the tip of the thermoelement is displaced in the upward direction, and as the temperature drops, it descends, as shown in FIG. 14. In FIG. 3, the vertical axis represents the protrusion / retraction amount (mm), and the horizontal axis represents the temperature (°C). The temperature (range) in FIGS. 3 and 4 only needs to satisfy the relationship A < B < C < D < E, and it varies depending on the use of the thermoelement and the like, so it does not show a specific temperature, and FIG. 3 represents a conceptual diagram (image diagram). The same applies to FIGS. 5(b) to 11(b) described later.

[0044] In the thermoelement of the present invention, as shown in FIG. 3, due to the autonomous operation of the large-diameter piston 4 and the small-diameter piston 10, the action of the high-load spring 2 and the low-load spring 1, and the action of various locking structures, after the protrusion / retraction length changes by a predetermined amount due to the volume change accompanying the state change of the wax, even when the wax state becomes a liquid phase, a slight volume expansion occurs, so the relationship between the protrusion / retraction amount and the temperature characteristics as shown in FIG. 3 can be obtained.

[0045] FIG. 5(a) is a detailed explanatory diagram of the operation image in the temperature range between A and B °C in FIG. 2(a), and FIG. 5(b) is a characteristic diagram showing the relationship between the temperature and the protrusion / retraction amount of the thermoelement during operation in the temperature range between A and B °C.

[0046] FIG. 5(a) shows the state (starting point) where the tip of the thermoelement is at the protrusion / retraction length P1 in the low-temperature range. The piston 4 is pushed in the direction of sinking into the housing cup 9 by the return load of the spring (high load) 2. Since the wax 8 is in a solid state, its volume is in the smallest state. Due to the state where the piston (large diameter) 4 is pushed in the direction of sinking into the housing cup 9, the piston (small diameter) 10 is pushed out in the direction of protruding from the housing cup 9, representing the state where the tip of the thermoelement is located at the protrusion / retraction length P1.

[0047] Here, the spring (high load) 2 needs to be a load that can push out the piston (small diameter) 10 and deflect the spring (low load) 1. This is because if the load is low, the piston (large diameter) 4 cannot push out the piston (small diameter) 10 in the direction of protruding from within the housing cup 9 and thus does not displace.

[0048] Figure 5(b) shows a state where the wax 8 is solid. Since the wax 8 is solid, its volume is the smallest, and due to the return load of the spring (high load) 2, the piston (large diameter) 4 is pushed in the direction of sinking into the housing cup 9. Along with the displacement of the piston (large diameter) 4 being pushed in the direction of sinking into the housing cup 9, the piston (small diameter) 10 is pushed out in the direction of protruding from within the housing cup 9.

[0049] Figure 6(a) is a detailed operation image explanatory diagram of the temperature range between B - C °C in Figure 2(a), and Figure 6(b) is a characteristic diagram showing the relationship between the temperature between B - C °C and the amount of protrusion and retraction of the tip of the thermoelement.

[0050] Figure 6(a) shows a state where the tip of the thermoelement is displaced from the protrusion / retraction length P1 to the protrusion / retraction length P2 in the temperature range between B and C °C. In the temperature range between B and C °C, part of the wax 8 melts, and volume expansion progresses more than in the temperature range between A and B °C. Against the biasing forces of the spring (low load) 1 and the spring (high load) 2, an internal pressure is generated in the housing cup 9 to try to project the piston (small diameter) 10 and the piston (large diameter) 4 from inside the housing cup 9. The cross-sectional area of the piston (large diameter) 4 and the biasing force generated by the spring (high load) 2 are set such that the force to project the piston (large diameter) 4 from the housing cup 9 generated by the internal pressure is larger than the biasing force generated by the spring (high load) 2. The cross-sectional area of the piston (small diameter) 10 and the biasing force generated by the spring (low load) 1 are set such that the force to project the piston (small diameter) 10 from the housing cup 9 generated by the internal pressure is smaller than the biasing force generated by the spring (low load) 1. Therefore, with the tips of the piston (large diameter) 4 and the piston (small diameter) 10 in contact, the piston (large diameter) 4 moves in the direction of projecting from the housing cup 9, and the piston (small diameter) 10 moves in the direction of retracting into the housing cup 9.

[0051] As shown in Figure 6(b), since the volume expansion amount of the wax 8 and the total volume of the piston (large diameter) 4 and the piston (small diameter) 10 projected and retracted from the housing cup 9 must match, according to the volume expansion amount of the wax 8 corresponding to the temperature within the temperature range between B and C °C, as the piston (large diameter) 4 and the piston (small diameter) 10 are projected and retracted from the housing cup 9, the tip of the thermoelement is positioned within the range from the protrusion / retraction amount P1 to the protrusion / retraction length P2 corresponding to the temperature within the temperature range between B and C °C.

[0052] Figure 7(a) is a detailed operation image explanatory diagram at C °C in Figure 2(a), and Figure 7(b) is a characteristic diagram showing the relationship between the temperature at C °C and the tip protrusion / retraction length of the thermoelement.

[0053] Figure 7(a) shows the state where the tip of the thermoelement is located at the protrusion / retraction length P2 at C°C. At C°C, wax 8 melts more than in the temperature range between B and C°C and volume expansion progresses. Against the biasing forces of spring (low load) 1 and spring (high load) 2, an internal pressure is generated in housing cup 9 to try to project piston (small diameter) 10 and piston (large diameter) 4 from within housing cup 9. The cross-sectional area of piston (large diameter) 4 and the biasing force generated by spring (high load) 2 are set such that the force to project piston (large diameter) 4 from housing cup 9 generated by the internal pressure is greater than the biasing force generated by spring (high load) 2. The cross-sectional area of piston (small diameter) 10 and the biasing force generated by spring (low load) 1 are set such that the force to project piston (small diameter) 10 from housing cup 9 generated by the internal pressure is smaller than the biasing force generated by spring (low load) 1. Therefore, with the tips of piston (large diameter) 4 and piston (small diameter) 10 in contact, piston (large diameter) 4 tries to move in the direction of projecting from housing cup 9 and piston (small diameter) 10 tries to move in the direction of retracting into housing cup 9, but the stopper provided on piston (small diameter) 10 contacts cover 13, preventing piston (small diameter) 10 from moving further in the direction of retracting into housing cup 9.

[0054] As shown in Figure 7(b), the tip of the thermoelement is located within the range of the protrusion / retraction length P2.

[0055] Figure 8(a) is a detailed explanatory diagram of the operation image in the temperature range between C and D°C in Figure 2(a), and Figure 8(b) is a characteristic diagram showing the relationship between the temperature in the temperature range between C and D°C and the tip protrusion / retraction amount of the thermoelement.

[0056] Figure 8(a) shows the state where the tip of the thermoelement is located at the protrusion / retraction length P2 in the temperature range between C and D °C. In the temperature range between C and D °C, part of the wax 8 melts, and the volume expansion progresses more than at the temperature of C °C. Against the biasing forces of the spring (low load) 1 and the spring (high load) 2, an internal pressure is generated in the housing cup 9 to try to protrude the piston (small diameter) 10 and the piston (large diameter) 4 from inside the housing cup 9. The cross-sectional area of the piston (large diameter) 4 and the biasing force generated by the spring (high load) 2 are set such that the force to protrude the piston (large diameter) 4 generated by the internal pressure is larger than the biasing force generated by the spring (high load) 2. The cross-sectional area of the piston (small diameter) 10 and the biasing force generated by the spring (low load) 1 are set such that the force to protrude the piston (small diameter) 10 generated by the internal pressure is smaller than the biasing force generated by the spring (low load) 1. And, since the stopper provided on the piston (small diameter) 10 contacts the cover 13 and the piston (small diameter) 10 cannot move in the direction of retracting into the housing cup 9, only the piston (large diameter) 4 moves in the direction of protruding from the housing cup 9.

[0057] As shown in Figure 8(b), since the piston (small diameter) 10 does not move either in the direction of retracting into the housing cup 9 or in the direction of protruding, the tip of the thermoelement is located within the range of the protrusion / retraction length P2. Incidentally, the amount of protrusion / retraction of the protrusion / retraction length P2 can be adjusted by adjusting the thickness of the stopper provided on the piston (small diameter) 10.

[0058] Figure 9(a) is a detailed explanatory diagram of the operation image at D °C in Figure 2(a), and Figure 9(b) is a characteristic diagram showing the relationship between the temperature at D °C and the protrusion / retraction amount of the thermoelement tip.

[0059] Figure 9(a) shows the state where the tip of the thermoelement is located at the protrusion / retraction length P2 at D °C. At D °C, wax 8 melts more in the temperature range between C and D °C and volume expansion progresses. Against the biasing forces of spring (low load) 1 and spring (high load) 2, an internal pressure is generated in the housing cup 9 to try to project piston (small diameter) 10 and piston (large diameter) 4 out of the housing cup 9. The cross-sectional area of piston (large diameter) 4 and the biasing force generated by spring (high load) 2 are set such that the force to project piston (large diameter) 4 from the housing cup 9 generated by the internal pressure is larger than the biasing force generated by spring (high load) 2. The cross-sectional area of piston (small diameter) 10 and the biasing force generated by spring (low load) 1 are set such that the force to project piston (small diameter) 10 from the housing cup 9 generated by the internal pressure is smaller than the biasing force generated by spring (low load) 1. Therefore, and because the stopper provided on piston (small diameter) 10 contacts cover 13 and piston (small diameter) 10 cannot move in the direction of sinking into housing cup 9, in the temperature range between C and D °C, only piston (large diameter) 4 moves in the direction of protruding from housing cup 9. However, at D °C, piston (large diameter) 4 contacts lid 3 and cannot move in the direction of protruding from housing cup 9.

[0060] As shown in Fig. 9(b), the tip of the thermoelement is located at the protrusion / retraction length P2.

[0061] Fig. 10(a) is a detailed operation image explanatory view of the temperature range between D and E °C in Fig. 2(a), and Fig. 10(b) is a characteristic diagram showing the relationship between the temperature in the temperature range between D and E °C and the protrusion / retraction length of the thermoelement tip.

[0062] Figure 10(a) shows the state where the tip of the thermoelement is displaced from the protrusion / retraction length P2 to the protrusion / retraction length P3 in the temperature range between D - E °C. In the temperature range between D - E °C, part of the wax 8 melts, and the volume expansion progresses more than at D °C. Against the biasing forces of the spring (low load) 1 and the spring (high load) 2, an internal pressure is generated in the housing cup 9 to try to project the piston (small diameter) 10 and the piston (large diameter) 4 out of the housing cup 9. A force is applied to project the piston (large diameter) 4 from the housing cup 9 by the internal pressure, but the piston (large diameter) 4 contacts the lid 3 and cannot move in the direction of projecting from the housing cup 9. Against the biasing force generated by the spring (low load) 1, the piston (small diameter) 10 moves in the direction of projecting from the housing cup 9 by the amount of volume expansion of the wax 8 compared to that at D °C.

[0063] As shown in Figure 10(b), since the volume expansion amount of the wax 8 must match the total volume of the piston (large diameter) 4 and the piston (small diameter) 10 protruded / retracted from the housing cup 9, according to the volume expansion amount of the wax 8 corresponding to the temperature within the temperature range between D - E °C, the piston (large diameter) 4 protrudes from the housing cup 9 until it contacts the lid 3, and the piston (small diameter) 10 moves in the direction of projecting from the housing cup 9. As a result, the tip of the thermoelement is located within the range from the protrusion / retraction length P2 to the protrusion / retraction length P3 corresponding to the temperature within the temperature range between D - E °C.

[0064] Figure 11(a) is a detailed operation image explanatory diagram of the temperature range of E °C or higher in Figure 2(a), and Figure 11(b) is a characteristic diagram showing the relationship between the temperature in the temperature range of E °C or higher and the protrusion / retraction length of the thermoelement tip.

[0065] Figure 11(a) shows that in the temperature range of E °C or higher, all of the wax 8 melts, and volume expansion progresses more than in the temperature range between D and E °C. Against the biasing forces of the spring (low load) 1 and the spring (high load) 2, an internal pressure is generated in the housing cup 9 to try to project the piston (small diameter) 10 and the piston (large diameter) 4 from within the housing cup 9. A force is applied to project the piston (large diameter) 4 from the housing cup 9 due to the internal pressure, but the piston (large diameter) 4 contacts the lid 3 and cannot move in the direction of projecting from the housing cup 9. Against the biasing force generated by the spring (low load) 1, the piston (small diameter) 10 moves in the direction of projecting from the housing cup 9 by the amount of volume expansion compared to when the wax 8 is at D °C.

[0066] As shown in Figure 11(b), since the volume expansion amount of the wax 8 must match the total volume of the piston (large diameter) 4 and the piston (small diameter) 10 projecting from and retracting into the housing cup 9, according to the volume expansion amount of the wax 8 corresponding to the temperature within the temperature range between D and E °C, the piston (large diameter) 4 projects from the housing cup 9 until it contacts the lid 3, and the piston (small diameter) 10 moves in the direction of projecting from the housing cup 9, so that the tip of the thermoelement is positioned at a projecting and retracting length of P3 or more corresponding to the temperature in the temperature range of E °C or higher. Note that since the liquid-phase volume expansion rate of the wax 8 in the temperature range of E °C or higher is smaller than the melting volume expansion rate in the temperature range between D and E °C, the displacement gradient of the tip of the thermoelement with respect to the temperature in the temperature range of E °C or higher is smaller compared to the temperature range between D and E °C.

[0067] Figure 12 is an image diagram of the use of the thermo-actuator to which the present invention is applied. (a) shows when the cooling water is at a low temperature, (b) shows when the cooling water is at a medium temperature, and (c) shows when the cooling water is at a high temperature. In Figures 12(a), (b), and (c), the thick solid arrows indicate the flow of the exhaust gas, and the dashed arrows indicate the flow of the cooling water.

[0068] As shown in FIGS. 12(a), (b), and (c), by using the thermo-element 120 of the present invention, as the temperature of the cooling water increases, the valve 122 of the flow path through which the exhaust gas flows to the heat exchanger 121 can be opened → closed → opened. Since the configuration of the thermo-element 120 of the present invention is the same as that shown in FIG. 1 or FIG. 13 described above, the description thereof is omitted here.

[0069] FIG. 13 is a cross-sectional view showing the configuration of a thermo-element according to another embodiment of the present invention. The thermo-element 200 shown in FIG. 13 shows a sleeve-type thermo-element configuration. Since the configuration of the sleeve 14 and the configurations other than the seals 6' and 12' are the same as those of the thermo-element in FIG. 1, the description thereof is omitted, and the different configurations will be described.

[0070] The first sealing member and the second sealing member integrally form a sealing member, and the first piston and the second piston are configured to be in direct or indirect contact within the through-hole of the sealing member. According to the sleeve-type configuration, since the piston is protected by the sleeve, the reliability can be improved as compared with the packing type without a sleeve.

[0071] Thus, in the thermo elements of this embodiment and other embodiments, since the heater heat is not utilized, there is no event of being deprived of heat and malfunctioning, and it becomes possible to operate in a low-temperature environment. In the case of water or an aqueous solution, there are problems that the melting point cannot be arbitrarily selected and the expansion rate is small. However, since paraffin wax can be used, it can operate at an arbitrary temperature and has a large expansion rate, which is superior to the thermo element of Japanese Patent No. 6399585 that uses two types of thermal expansion bodies. Instead of a complex electric control mechanism, since only wax is encapsulated inside the pellets of the existing configuration, the number of parts is reduced and the manufacturing cost is low. Since an electric control mechanism is not required, it is miniaturized compared to conventional electric control thermo actuators, and the component cost is reduced. Since the assembly of the electric control mechanism part is unnecessary, productivity is improved. In addition to the operation of a normal thermostat, re-operation is possible, so it can be applied in other fields with operations such as valve opening at extremely low temperatures, valve closing at normal temperature, and valve opening at high temperatures (or valve closing at low temperatures, valve opening at normal temperature, and valve closing at high temperatures). Since it moves autonomously, wiring and a drive control device on the vehicle side are unnecessary.

[0072] As described above, the thermo element according to the embodiment of the present invention has been described in detail. However, any of the embodiments described above or illustrated is merely one embodiment that embodies the present invention. Therefore, the technical scope of the present invention should not be construed in a limited manner by these. In particular, it goes without saying that the materials of each member are merely examples and can be appropriately changed to other materials having equivalent strength.

Explanation of Reference Numerals

[0073] 100, 200: Thermo element 1: Spring (second biasing member) 2: Spring (first biasing member) 3: Lid 4: Piston (first piston) 5: Cover (large diameter) 6: Seal (backup ring) 6’: Seal (backup ring) 7: Packing (sealing member) 8: Volume Expander 9: Housing Cup 10: Piston (Second Piston) 11: Packing (Sealing Member) 12: Seal (Backup Ring) 12’: Seal (Backup Ring) 13: Cover (Small Diameter) 14: Sleeve (Sealing Member) 120: Thermo Element 121: Heat Exchanger 122: Valve

Claims

1. A thermo-element, comprising: a container; a volume expander accommodated in the container and expanding or contracting in volume due to a change in ambient temperature; a first piston actuated by a change in volume of the volume expander due to a change in ambient temperature of the container; a second piston having a diameter different from that of the first piston and actuated by a change in volume of the volume expander due to a change in ambient temperature of the container; a first sealing member disposed at one end of the container and having a first through hole; a second sealing member disposed at the other end of the container and having a second through hole with a diameter different from that of the first through hole; wherein the first piston slidably penetrates the first sealing member, and the second piston slidably penetrates the second sealing member, and the tips of the first piston and the second piston are configured to be in direct or indirect contact with each other inside the container.

2. The first piston and the second piston are each configured such that a first biasing force by a first biasing member and a second biasing force by a second biasing member bias them in a retracting direction, and the magnitude of the first biasing force is configured to be greater than that of the second biasing force. The thermo-element according to claim 1.

3. The relationship between the first biasing force and the second biasing force is configured to satisfy the following relational expression (1). The thermo-element according to claim 2. 【Number 1】

4. The thermo-element according to claim 3, further comprising a locking structure that stops the first piston at a predetermined amount of protrusion or retraction even when the ambient temperature rises.

5. The thermo-element according to claim 4, wherein the first piston is configured with a stopper so that the first piston does not enter the container by more than a predetermined value.

6. The first sealing member and the second sealing member integrally form a sealing member, and the first piston and the second piston are configured to be in direct or indirect contact with each other inside the through hole of the sealing member. The thermo-element according to claim 5.

7. The thermo-element according to claim 5 or 6, wherein the second piston has a cover provided with a stopper mechanism so that the second piston does not sink by more than a predetermined amount of protrusion or retraction.

8. The thermoelement according to claim 5 or 6, wherein the second piston is provided with a stopper mechanism so that the second piston does not dive to a predetermined amount of protrusion and retraction.

9. The thermoelement according to claim 5 or 6, further comprising a lid that moves integrally with the container on the side of the first piston, wherein the stopper and the lid are configured such that the first biasing member is locked thereto.

Images