Thermal Response Element and its Manufacturing Method

Abstract

This invention provides a thermal response element with high freedom in setting hysteresis over a wide temperature range and capable of setting relatively small hysteresis. A plate-shaped thermal response element (100) whose shape changes with temperature is described. At room temperature, the cross-section of the thermal response element is a composite curve composed of multiple curves, with different curves at the center (121) and the outer periphery (122) surrounding the center. When the temperature reaches a predetermined range outside room temperature, the shape of the thermal response element changes, and the cross-section of the thermal response element after the shape change is again a composite curve composed of multiple curves. The cross-sections at the center and the outer periphery surrounding the center are different curves, and the boundary (123) between the center and the outer periphery is the same before and after the shape change.

Description

Technical Field

[0001] This invention relates to thermal response elements used in temperature switches such as thermostats and methods for manufacturing the same. Background Technology

[0002] In defrosting heaters installed in refrigerators and equipment used in cold regions, or in antifreeze heaters installed in water pipes and manufacturing equipment in chemical plants, temperature switches such as thermostats are used to prevent overheating or for temperature control. In antifreeze applications of water pipes, temperature switches are used that, for example, start energizing the heater at 3°C ​​and stop energizing at 10°C. Furthermore, in industrial and commercial applications, temperature switches capable of controlling the temperature of refrigerators between -30°C and -20°C, and temperature switches capable of controlling the temperature of heaters between 90°C and 100°C, are required.

[0003] When using bimetallic components as the thermal response element of such temperature switches, a small hysteresis is required.

[0004] Patent document 1 describes a bimetallic part that can be manufactured with its reversal temperature and recovery temperature arbitrarily adjustable and its temperature range being approximately -30°C to 200°C.

[0005] Furthermore, Patent Document 2 describes a bimetallic disk with a small temperature difference (hysteresis) between reversal and re-reversal. This bimetallic disk is formed by bending a flat bimetallic disk around its circumference at a certain distance from the center, so that the cross-sectional shape of the center and the periphery are both straight, thus forming a dish-like shape with edges. It is also pointed out that it can operate at a temperature lower than room temperature by bending towards the low expansion side.

[0006] Furthermore, Patent Document 3 describes a disc-shaped bimetallic part characterized by having at least one surface of the convex region having irregularities to increase its surface area. This disc-shaped bimetallic part has low reversal and recovery temperatures, and a small temperature difference between them.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 63-16285

[0010] Patent Document 2: Japanese Patent Application Publication No. 58-198788

[0011] Patent Document 3: Japanese Patent Publication No. 48-10429 Summary of the Invention

[0012] The problem the invention aims to solve

[0013] Furthermore, when using bimetallic components as thermal response elements, it is known that their operating temperature and recovery temperature are closely related to the shape of the bimetallic component. However, Patent Document 1 only describes a spherical shape and does not provide a specific method for arbitrarily setting the temperature within a variety of temperature ranges. While Patent Document 2 indicates that a bimetallic component can be configured to operate at temperatures lower than room temperature, it does not describe a detailed method or a specific operating temperature. Moreover, it is conceivable that the machining of the uneven surface in Patent Document 3 is complex.

[0014] Therefore, the object of the present invention is to provide a thermal response element that allows for a high degree of freedom in setting the hysteresis over a wide temperature range, from a low temperature range below room temperature to a high temperature range above 100°C, and also allows for setting a relatively small hysteresis.

[0015] Solution for solving the problem

[0016] One aspect of the present invention relates to a plate-shaped thermal response element whose shape changes with temperature. At room temperature, the cross-section of the thermal response element is a composite curve composed of multiple curves, with different curves at the center and around the periphery. When the temperature reaches a predetermined range outside room temperature, the shape of the thermal response element changes, and the cross-section of the changed thermal response element remains a composite curve composed of multiple curves, with different curves at the center and around the periphery. The boundaries of the center and periphery are the same before and after the shape change.

[0017] Invention Effects

[0018] According to the present invention, a thermal response element is provided that allows for a high degree of freedom in setting the hysteresis over a wide temperature range, from a low temperature range below room temperature to a high temperature range above 100°C, while also allowing for setting a relatively small hysteresis. Attached Figure Description

[0019] Figure 1 This is a top view of the thermal response element in the first embodiment.

[0020] Figure 2 yes Figure 1 A-A' line cross-section diagram.

[0021] Figure 3 This is a cross-sectional view of the thermal response element after inversion.

[0022] Figure 4A This is an explanatory diagram showing the first step of the manufacturing method of a thermally responsive element.

[0023] Figure 4B This is an explanatory diagram showing the second step of the manufacturing method of the thermal response element.

[0024] Figure 5A This is an explanatory diagram showing the first step of another manufacturing method for a thermally responsive element.

[0025] Figure 5B This is an explanatory diagram showing the second step of another manufacturing method for a thermally responsive element.

[0026] Figure 6 This is a three-dimensional view of the punch used in the second process.

[0027] Figure 7 This is a cross-sectional view of the second process.

[0028] Figure 8 This is a top view of the thermal response element in the second embodiment.

[0029] Figure 9 yes Figure 8 The cross-sectional view of line B-B'.

[0030] Figure 10 This is a cross-sectional view of the thermal response element after inversion.

[0031] Figure 11A This is an explanatory diagram showing the first step of the manufacturing method of a thermally responsive element.

[0032] Figure 11B This is an explanatory diagram showing the second step of the manufacturing method of the thermal response element.

[0033] Figure 12A This is an explanatory diagram showing the first step of another manufacturing method for a thermally responsive element.

[0034] Figure 12B This is an explanatory diagram showing the second step of another manufacturing method for a thermally responsive element.

[0035] Figure 13A This is a top view of the thermal response element in the third embodiment.

[0036] Figure 13B This is another top view of the thermal response element in the third embodiment.

[0037] Figure 13C This is another top view of the thermal response element in the third embodiment.

[0038] Figure 14A This is a top view of the thermal response element according to the fourth embodiment.

[0039] Figure 14BThis is another top view of the thermal response element in the fourth embodiment.

[0040] Figure 14C This is another top view of the thermal response element in the fourth embodiment.

[0041] Figure 15 This is a top view of the thermal response element in the fifth embodiment. Detailed Implementation

[0042] The present invention will now be described based on the illustrated embodiments. However, the present invention is not limited to the embodiments described below. Additionally, the dimension ratios of the shapes shown in the figures are sometimes not actual dimension ratios. The dimension ratios have sometimes been changed for ease of understanding and illustration.

[0043] In this instruction manual, "room temperature" (or "normal temperature") refers to a temperature above 18°C ​​and below 38°C.

[0044] [First Implementation Method]

[0045] [constitute]

[0046] Figure 1 This is a top view of the bimetallic component 100, which serves as the thermal response element in this embodiment. Figure 2 yes Figure 1 The cross-sectional view along line A-A'. Both figures show the shape of the bimetallic part 100 at room temperature, formed by multi-stage pressing using a punch and die.

[0047] like Figure 1 and Figure 2 As shown, the bimetallic component 100 is a plate-shaped member having a low-expansion layer 111 and a high-expansion layer 112 located below the low-expansion layer. The thermal expansion coefficient of the material of the high-expansion layer 112 is greater than that of the material of the low-expansion layer 111.

[0048] Furthermore, the bimetallic member 100 has a central portion 121, an outer peripheral portion 122 surrounding the central portion, and a boundary 123 between the central portion 121 and the outer peripheral portion 122. When viewed from above, the bimetallic member 100 has a concave shape with the central portion 121 recessed, and when viewed from below, it has a convex shape with the central portion 121 protruding. The bimetallic member 100 can also be described as a dish-shaped part with edges. The angle α1 formed by the central portion 121 and the outer peripheral portion 122 is an obtuse angle. The cross-sectional structure of the bimetallic member 100 is a composite curve composed of multiple curves. Specifically, the cross-sectional structure of the central portion 121 is an upwardly convex curve, and the cross-sectional structures of the two outer peripheral portions 122 located on either side of the central portion 121 are also upwardly convex curves. In the central portion 121 and the two outer peripheral portions 122, the radii of curvature of each curve can be the same or different.

[0049] When viewed from above, the central part 121 is circular, and the outer perimeter 122 is a rounded quadrilateral.

[0050] Boundary 123 lies on the circumference of a concentric circle with a diameter of length L12 that is 1% to 50% of the diameter of the circumscribed circle 131 of the outer periphery 122. However, the diameter of this concentric circle is smaller than the width of the rounded quadrilateral described above.

[0051] For example, a Ni-Fe alloy can be used as the material for the bimetallic part 100, and a Cu-Ni-Mn alloy can be used in the low-expansion layer 111 and the high-expansion layer 112. The length, width, corner shape, and plate thickness of the rounded quadrilateral can be arbitrarily set according to the target reversal temperature.

[0052] When the temperature of the bimetallic component decreases and falls below a specified temperature (recovery temperature) lower than room temperature, the bimetallic component reverses through a snap action, from... Figure 2 The shape shown becomes Figure 3 The bimetallic part 100, when viewed from above, has a convex shape with the center portion 121 protruding, and when viewed from below, it has a concave shape with the center portion 121 recessed.

[0053] The inverted shape is a composite curve composed of multiple curves. The boundary 123 between the central part 121 and the outer periphery 122 remains unchanged before and after the inversion.

[0054] exist Figure 3 In the design, the cross-sectional structure of the central portion 121 is an upwardly convex curve, and the cross-sectional structures of the two outer peripheral portions 122 located on both sides of the central portion 121 are also upwardly convex curves. The radii of curvature of each curve can be the same or different.

[0055] exist Figure 3 In the middle, the angle β1 formed by the central part 121 and the outer peripheral part 122 is an obtuse angle larger than the angle α1.

[0056] By utilizing the characteristic that angle β1 is larger than angle α1 and that each of the central portion 121 and the two outer peripheral portions 122 is an upwardly convex curve, which remains unchanged before and after reversal, a relatively small hysteresis setting of about 10 degrees (deg) can be achieved. Furthermore, as... Figure 2 As shown, since the central part 121 and the two outer peripheral parts 122 are curved in the same direction (inward) (an upward convex curve), it is also possible to set an extremely low recovery temperature.

[0057] Furthermore, when the temperature of the bimetallic component rises and reaches a specified temperature (operating temperature) lower than room temperature, the bimetallic component reverses rapidly, from... Figure 3 The shape shown returns to Figure 2 The shape shown. The operating temperature is higher than the recovery temperature mentioned above.

[0058] In a composite curve, the boundary between one curve and another can be curved or angular.

[0059] Furthermore, the section described refers to the section of a straight line parallel to the long side of the bimetallic piece and passing through the center of the circumcircle, but the section of any straight line passing through the center also has the same characteristics.

[0060] in addition, Figure 2 This describes the shape at room temperature after being formed using a punch and die through a multi-stage pressing process. However, bimetallic parts formed by pressing and then heat-treated also exhibit the same characteristics in terms of shape at room temperature.

[0061] [Manufacturing Method]

[0062] The method for manufacturing the bimetallic part 100 includes: a step of cutting a bimetallic part raw material composed of two metal layers with different coefficients of thermal expansion into an arbitrary shape; and a step of forming the cut bimetallic part raw material into the bimetallic part 100 by using a multi-stage pressing process with a stamping machine. The multi-stage pressing process is performed while the bimetallic part raw material and a die including a punch and a die are maintained at a temperature similar to room temperature (above 18°C ​​and below 38°C). However, the multi-stage pressing process can also be performed after cooling or heating. The punch is made of metal, such as alloy tool steel, and the die is made of an elastic material.

[0063] exist Figure 4A The diagram shows the first step of pressing the cut bimetallic material 100a. The cut bimetallic material 100a is placed onto a die D with a flat surface. At this time, the bimetallic material 100a is arranged such that the low-expansion layer 111 is on the side of the metal punch P1 and the high-expansion layer 112 is on the side of the die D. Then, the punch P1, with its convex end face, is moved downwards to press the bimetallic material 100a. Through this first step, bimetallic material 100b can be obtained (…). Figure 4B ).

[0064] exist Figure 4BThe diagram shows a second process (the final pressing process) that further presses the bimetallic material 100b formed in the first process. The bimetallic material 100b obtained in the first process is placed onto a die D with a flat surface. At this time, the bimetallic material 100b is arranged such that the low-expansion layer 111 is on the metal side of the punch P2, and the high-expansion layer 112 is on the die D side. Then, the punch P2, which has protrusions formed on its end face, is moved downwards to press the bimetallic material 100b. Through this second process, a... Figure 1 and Figure 2 The bimetallic part 100 is shown.

[0065] like Figure 5A As shown, in the first process, when the cut bimetallic raw material 100a is placed onto the die D, the high expansion layer 112 can be positioned on the punch P1 side, and the low expansion layer 111 on the die D side. This allows it to be configured to be... Figure 4A The configuration of the bimetallic raw material 100a shown is the opposite of the configuration. Through this first process, the bimetallic raw material 100c can be obtained. Figure 5B ).

[0066] Then, in Figure 5B In the second process shown, with Figure 4B Similarly, the bimetallic raw material 100c is configured with the low expansion layer 111 as the punch P2 side and the high expansion layer 112 as the die D side for pressing processing.

[0067] like Figure 6 As shown, a generally cylindrical protrusion X is formed approximately at the center of the end face Y of the generally cylindrical punch P2. The diameter L13 of the protrusion X is 1% to 50% of the diameter L11 of the circumscribed circle 131 of the aforementioned rounded quadrilateral. The protrusion H of the protrusion X from the end face Y is 0.05 to 1 mm. The end face X and the surrounding end face Y can be flat or dish-shaped (recessed). However, the diameter L14 of the end face Y is preferably greater than or equal to the diameter L11 of the circumscribed circle 131.

[0068] Furthermore, the end face Y is not limited to a circle; it can also be set to an ellipse or a quadrilateral (not shown).

[0069] Reference Figure 7The effect of the second process (the final pressing process) using punch P2 and die D made of elastic material will be explained. When the bimetallic raw material 100b (or bimetallic raw material 100c) after the first process is placed on die D and punch P2 is lowered, the central portion 121b and the outer peripheral portion 122b of the bimetallic raw material 100b are clamped and fixed by punch P2 and die D. Then, when pressing is continuously performed by punch P2, the aforementioned composite curved cross-sectional shape is generated along with the push-back of die D made of elastic material. Unlike the prior art, the periphery of the boundary 123 is given a high degree of machining that cannot be obtained by pressing with a simple curved punch. As a result, extremely low or extremely high operating temperature and recovery temperature, and a relatively small backlash of about 10 degrees can be set.

[0070] In addition, Figure 7 The diagram illustrates a manufacturing method using a metal punch and a die made of an elastic material, but is not limited to this. Alternatively, after machining the shape of the bimetallic part raw material, it can be clamped and pressed using upper and lower metal dies (upper and lower dies) with curved shapes matching the desired bimetallic part's curve shape. The pressed bimetallic part raw material is then subjected to a heat treatment at a temperature of 50°C to 300°C for, for example, 1 hour.

[0071] [Function / Effect]

[0072] In the manufacturing method described above, the raw materials (composition, plate thickness, temperature) of the bimetallic part, the shape after cutting, the pressing (force, time, temperature) of the first and second processes, the end face shape of punch P1, the end face shape of punch P2 (diameter lengths L13 and L14, protrusion H), and the material of the die are appropriately selected. This allows for setting an operating temperature lower than room temperature and freely setting the recovery temperature. It also allows for setting a relatively small hysteresis of around 10 degrees. By changing the end face shape of punch P1 in the first process, the operating temperature, recovery temperature, and hysteresis can also be adjusted.

[0073] Furthermore, it is conceivable that when the diameter L12 of the center portion 121 is less than 1% of the diameter L11 of the circumscribed circle 131, the hysteresis adjustment effect is small. When the diameter L12 of the center portion 121 exceeds 50% of the diameter L11, the bimetallic part is difficult to reverse via rapid movement. In addition, even if reversal is achieved, the height after reversal is low. That is, it is conceivable that this is not preferred for use in applications such as temperature switches (it cannot be effectively utilized in the switching on and off of electrical contacts).

[0074] [Second Implementation]

[0075] [constitute]

[0076] Figure 8 This is a top view of the bimetallic component 200, which serves as the thermal response element in this embodiment.

[0077] Figure 9 yes Figure 8 The B-B' line cross-sectional view. Both figures show the shape of the bimetallic part 200 at room temperature after being formed by multi-stage pressing using a punch and die.

[0078] like Figure 8 and Figure 9 As shown, the bimetallic component 200 is a plate-shaped member having a low-expansion layer 211 and a high-expansion layer 212 located below the low-expansion layer. The thermal expansion coefficient of the material of the high-expansion layer 212 is greater than that of the material of the low-expansion layer 211.

[0079] Furthermore, the bimetallic member 200 has a central portion 221, an outer peripheral portion 222 surrounding the central portion, and a boundary 223 between the central portion 221 and the outer peripheral portion 222. When viewed from above, the bimetallic member 200 has a convex shape with the central portion 221 protruding, and when viewed from below, it has a concave shape with the central portion 221 recessed. The bimetallic member 200 can also be described as a dish-shaped part with edges. The angle α2 formed by the central portion 221 and the outer peripheral portion 222 is an obtuse angle. The cross-sectional structure of the bimetallic member 200 is a composite curve composed of multiple curves. Specifically, the cross-sectional structure of the central portion 221 is a downward convex curve, and the cross-sectional structures of the two outer peripheral portions 222 located on either side of the central portion 221 are also downward convex curves. In the central portion 221 and the two outer peripheral portions 222, the radii of curvature of each curve can be the same or different.

[0080] When viewed from above, the central part 221 is circular, and the outer perimeter 222 is a rounded quadrilateral.

[0081] Boundary 223 lies on the circumference of a concentric circle with a diameter L22 that is 1% to 50% of the length of the diameter L21 of the circumscribed circle 231 of the outer periphery 222. However, the length L22 of the diameter of this concentric circle is smaller than the width of the rounded quadrilateral described above.

[0082] For example, a Ni-Fe alloy can be used as the material for the bimetallic part 200, and a Cu-Ni-Mn alloy can be used in the low-expansion layer 211 and the high-expansion layer 212. The length, width, corner shape, and plate thickness of the rounded quadrilateral can be arbitrarily set according to the target reversal temperature.

[0083] When the temperature of the bimetallic component rises and reaches a specified temperature (operating temperature) higher than room temperature, the bimetallic component reverses rapidly, from... Figure 9 The shape shown becomes Figure 10The bimetallic part 200, when viewed from above, has a concave shape with the center 221 recessed, and when viewed from below, it has a convex shape with the center 221 protruding.

[0084] The inverted shape is a composite curve composed of multiple curves. The boundary 223 between the central part 221 and the outer periphery 222 remains unchanged before and after the inversion.

[0085] exist Figure 10 In the design, the cross-sectional structure of the central portion 221 is a downward convex curve, and the cross-sectional structures of the two outer peripheral portions 222 located on both sides of the central portion 221 are also downward convex curves. The radii of curvature of each curve can be the same or different.

[0086] exist Figure 10 In the middle, the angle β2 formed by the central part 221 and the outer peripheral part 222 is an obtuse angle larger than the angle α2.

[0087] By utilizing the characteristic that angle β2 is larger than angle α2 and that each of the central portion 221 and the two outer peripheral portions 222 is a downwardly convex curve that remains unchanged before and after reversal, a relatively small hysteresis setting of around 10 degrees can be achieved. Furthermore, as... Figure 9 As shown, since the central part 221 and the two outer peripheral parts 222 are curved in the same direction (inward) (downward convex curve), it is possible to set extremely high operating temperatures.

[0088] Furthermore, when the temperature of the bimetallic component decreases and falls below the specified temperature (recovery temperature), the bimetallic component reverses rapidly, from... Figure 10 The shape shown returns to Figure 9 The shape shown. This recovery temperature is lower than the aforementioned operating temperature.

[0089] In a composite curve, the boundary between one curve and another can be curved or angular.

[0090] Furthermore, the section described refers to the section of a straight line parallel to the long side of the bimetallic piece and passing through the center of the circumcircle, but the section of any straight line passing through the center also has the same characteristics.

[0091] in addition, Figure 9 This describes the shape at room temperature after being formed using a punch and die through a multi-stage pressing process. However, bimetallic parts formed by pressing and then heat-treated also exhibit the same characteristics in terms of shape at room temperature.

[0092] [Manufacturing Method]

[0093] The manufacturing method of the thermal response element 200 in this embodiment is substantially the same as the manufacturing method of the thermal response element 100 in the first embodiment. However, in the second step of the manufacturing method of the thermal response element 100, the bimetallic material is pressed from the low expansion layer side, but in the second step of the manufacturing method of the thermal response element 200, the bimetallic material is pressed from the high expansion layer side.

[0094] exist Figure 11A The diagram shows the first step of pressing the cut bimetallic material 200a. The cut bimetallic material 200a is placed onto a die D with a flat surface. At this time, the bimetallic material 200a is arranged such that the high expansion layer 212 is on the punch P1 side and the low expansion layer 211 is on the die D side. Then, the punch P1, with its convex end face, is moved down to press the bimetallic material 200a. Through this first step, bimetallic material 200b can be obtained. Figure 11B ).

[0095] exist Figure 11B The diagram shows a second process (the final pressing process) that further presses the bimetallic material 200b obtained in the first process. The bimetallic material 200b obtained in the first process is placed onto a die D with a flat surface. At this time, the bimetallic material 200b is arranged such that the high expansion layer 212 is on the punch P2 side and the low expansion layer 211 is on the die D side. Then, the punch P2, which has protrusions formed on its end face, is moved downwards to press the bimetallic material 200b. Through this second process, a... Figure 8 and Figure 9 The bimetallic part 200 is shown.

[0096] like Figure 12A As shown, in the first process, when the cut bimetallic raw material 200a is placed onto the die D, the low expansion layer 211 can be positioned on the punch P1 side, and the high expansion layer 212 on the die D side. This allows it to be configured to be... Figure 11A The configuration of the bimetallic raw material 200a shown is the opposite of that shown. Through this first process, the bimetallic raw material 200c can be obtained ( Figure 11B ).

[0097] Furthermore, in Figure 12B In the second process shown, with Figure 11B Similarly, the bimetallic raw material 100c is configured with the high expansion layer 212 as the punch P2 side and the low expansion layer 211 as the die D for pressing processing.

[0098] Punches P1 and P2 are made of metal, such as alloy tool steel, while die D is made of an elastic material. The machined bimetallic part is subjected to heat treatment at a temperature of 100°C to 500°C for, for example, 1 hour.

[0099] [Function / Effect]

[0100] In the manufacturing method described above, the raw materials (composition, plate thickness, temperature) of the bimetallic part, the shape after cutting, the pressing (force, time, temperature) of the first and second processes, the end face shape of punch P1, the end face shape of punch P2 (diameter lengths L13 and L14, protrusion H), and the material of the die are appropriately selected. This allows for setting an operating temperature higher than room temperature and freely setting the recovery temperature. It also allows for setting a relatively small hysteresis of around 10 degrees. By changing the end face shape of punch P1 in the first process, the operating temperature, recovery temperature, and hysteresis can also be adjusted.

[0101] Furthermore, it is conceivable that when the diameter L22 of the center portion 221 is less than 1% of the diameter L21 of the circumscribed circle 231, the hysteresis adjustment effect is small. When the diameter L22 of the center portion 221 exceeds 50% of the diameter L21, the bimetallic part is difficult to reverse via rapid movement. In addition, even if reversal is achieved, the height after reversal is low. That is, it is conceivable that this is not preferred for use in applications such as temperature switches (it cannot be effectively utilized in the switching on and off of electrical contacts).

[0102] [Third Implementation Method]

[0103] Figures 13A-13C This is a top view of a bimetallic part whose shape differs from that of the bimetallic parts in the first and second embodiments.

[0104] like Figure 13A As shown, the bimetallic part 300 is circular in top view, having a circular central portion 321 and an outer peripheral portion 322. The length L2 of the diameter of the central portion 321 is 1% to 50% of the length L1 of the diameter of the bimetallic part 300.

[0105] like Figure 13B As shown, the bimetallic part 400 is elliptical in top view, having a circular central portion 421 and an outer peripheral portion 422. The length L2 of the diameter of the central portion 421 is 1% to 50% of the length L1 of the diameter of the circumscribed circle 431 of the outer peripheral portion of the bimetallic part 400.

[0106] like Figure 13CAs shown, the bimetallic member 500 is rhomboid in top view, having a circular central portion 521 and an outer peripheral portion 522. The length L2 of the diameter of the central portion 521 is 1% to 50% of the length L1 of the diameter of the circumscribed circle 531 of the outer peripheral portion of the bimetallic member 500.

[0107] The cross-sectional shapes of bimetallic parts 300, 400, and 500 are the same as those of bimetallic parts 100 or 200. Through these bimetallic parts 300, 400, and 500, the same functions and effects as described above can be achieved.

[0108] [Fourth Implementation Method]

[0109] Figures 14A-14C This is a top view of a bimetallic part whose central part shape differs from that of the bimetallic parts in the first and second embodiments.

[0110] like Figure 14A As shown, the bimetallic member 600 is quadrilateral in top view, having an elliptical central portion 621 and an outer peripheral portion 622. The major axis of the central portion 621 extends in the width direction of the bimetallic member 600. The length L2 of the major axis is 1% to 50% of the length L1 of the diameter of the circumscribed circle 631 of the outer peripheral portion of the bimetallic member 600. The center of the central portion 621 is located at the center of the circumscribed circle 631.

[0111] like Figure 14B As shown, the bimetallic member 700 is quadrilateral in top view, having an elliptical central portion 721 and an outer peripheral portion 722. The major axis of the central portion 721 extends along the long side of the bimetallic member 700. The length L2 of the major axis is 1% to 50% of the length L1 of the diameter of the circumscribed circle 731 of the outer peripheral portion of the bimetallic member 700. The center of the central portion 721 is located at the center of the circumscribed circle 731.

[0112] like Figure 14C As shown, the bimetallic component 800 is quadrilateral in top view, having a central portion 821 and an outer peripheral portion 822. The central portion 821 is peanut-shaped (narrow in the middle and bulging on both sides), and the long side of the central portion 821 is parallel to the long side of the bimetallic component 800. The length L2 of the central portion 821 is 1% to 50% of the length L1 of the diameter of the circumscribed circle 831 of the outer peripheral portion of the bimetallic component 800. The center of the central portion 821 is located at the center of the circumscribed circle 831.

[0113] When manufacturing bimetallic parts 600, 700, and 800, the shape of the protrusion X of the punch P2 can be set to an elliptical or peanut shape. The cross-sectional shape of bimetallic parts 600, 700, and 800 is the same as that of bimetallic parts 100 or 200. With such bimetallic parts 600, 700, and 800, the same functions and effects as described above can be obtained.

[0114] By setting the major axis of the elliptical or peanut-shaped central portion to either the long side or width of the bimetallic component, hysteresis can be adjusted, or the reversal height during bimetallic component reversal can be varied. Setting the major axis of the elliptical or peanut-shaped central portion to the width of the bimetallic component results in a greater height of the bimetallic component after reversal compared to setting it to the long side. This increased height allows for greater lifting of the movable plate with the movable contact when used in temperature switches, for example, increasing the circuit-breaking current capacity. Furthermore, by making the central portion non-circular, a wide variety of bimetallic component reversal characteristics can be created.

[0115] [Fifth Implementation Method]

[0116] exist Figure 15 The diagram shows a bimetallic member 150. This bimetallic member 150 is a bimetallic member in which a hole 151 is provided in the center portion 121 of the bimetallic member 100 in the first embodiment. Alternatively, a hole may be provided in the center portion 221 of the bimetallic member 200 in the second embodiment.

[0117] The aforementioned hole can be used for positioning or fixing the bimetallic component when assembling it into a temperature switch or similar device. The hole is not limited to a circle and can also be elliptical (not shown). However, it is preferable that the hole is located inside the boundary 123 between the central portion 121 and the outer peripheral portion 122, and that the center of the hole coincides with the center of the circumscribed circle 131.

[0118] The formation of the hole can be performed before the pressing process, or in the middle of the pressing process (between the first and second processes) or after the last stage of the process.

[0119] Such bimetallic components can achieve the same function and effect as described above.

[0120] Furthermore, the shape of the bimetallic part, the shape of the central portion, and the hole portion described in the third to fifth embodiments can be combined, and the first and second embodiments can be implemented by appropriate modifications. The pressing process is described as two processes in total, the first and second processes, but it can also be three or more processes. However, in the final pressing process, the bimetallic part is formed by a punch with a protruding portion and a die with a flat portion. As a result, the aforementioned effects and benefits can be obtained.

[0121] In embodiments 1 and 2, the first process is performed after the bimetallic material is cut, but the pressing process of the first process can also be performed simultaneously with the cutting of the bimetallic part. Alternatively, progressive stamping can be used to perform the processes of opening holes, punching shapes, pressing, and cutting bimetallic parts.

[0122] The operating temperature and recovery temperature can be adjusted by controlling the temperature and time of heat treatment on the bimetallic part after pressing. Increasing the temperature and time of heat treatment can improve both the operating temperature and recovery temperature.

[0123] [Example]

[0124] Next, referring to Table 1, the experiments conducted to confirm the effects of the first to third and fifth embodiments described above and their results are explained. Furthermore, a stamping press was used in all experiments; alloy tool steel was used as the raw material for the punch, and urethane was used as the elastic material for the die. The pressing pressure in the first and second processes was measured using a force sensor (load converter). The operating temperature and recovery temperature were measured by detecting the impact of the bimetallic part's reversal by using a bimetallic part temperature monitoring device that measures the temperature change within the tank via air circulation. As mentioned earlier, the temperature will increase from... Figure 3 The shape is reversed to Figure 2 The shape, or from Figure 9 The shape is reversed to Figure 10 The temperature of the shape, as the operating temperature, will decrease from [a certain value] as the temperature decreases. Figure 2 The shape is reversed to Figure 3 The shape, or from Figure 10 The shape is reversed to Figure 9 The temperature of the shape is used as the recovery temperature. In the experiment, the operating temperature was determined by increasing the temperature in the tank at a rate of 1℃ / 1 minute, and the recovery temperature was determined by decreasing the temperature in the tank at a rate of 1℃ / 1 minute.

[0125] [Table 1]

[0126]

[0127] [Example 1 (corresponding to the first embodiment)]

[0128] The bimetallic part with a plate thickness of 0.15 mm (the low expansion layer is a Ni-Fe alloy, and the high expansion layer is a Cu-Ni-Mn alloy) is cut into... Figure 1 The bimetallic part is shown as a rounded quadrilateral. Its dimensions are 14mm × 10mm, with the four corners designed as curved sections with a radius of curvature of 3mm. The diameter of the circumcircle of this bimetallic part is 14.9mm. The bimetallic part and the die containing the punch and die are maintained at a temperature similar to room temperature.

[0129] As the first step, the bimetallic part is positioned onto a die with a flat surface. A punch with a radius of curvature of 24 mm at its tip is lowered and pressed against the bimetallic part with a force of approximately 100 kgf for about 1 second. At this point, the low-expansion layer of the bimetallic part becomes the punch side and the high-expansion layer becomes the die side, or the high-expansion layer becomes the punch side and the low-expansion layer becomes the die side.

[0130] Next, as the second and final pressing step, the bimetallic part formed in the first step is placed onto a flat die, and a punch with a protrusion is lowered and pressed against the bimetallic part. At this point, the low-expansion layer of the bimetallic part becomes the punch side, and the high-expansion layer becomes the die side. The shape of the protrusion is... Figure 6 Similarly, the end face of protrusion X and end face Y are set as planes. The length L13 of the diameter of the end face of protrusion X is set to 5 mm, the protrusion amount H is set to 0.3 mm, and the length L14 of the diameter of face Y is set to 15 mm. The length L13 (5 mm) is approximately 34% of the diameter of the circumscribed circle, which is 14.9 mm. The pressing time is set to approximately 1 second, and after pressing, a heat treatment at 200°C is performed for 1 hour.

[0131] Table 1 shows the results of experiments conducted by varying the pressing pressure in the second process, as presented in Examples 1-1 to 1-5. As shown in Table 1, the operating temperature and recovery temperature were below room temperature. As shown in Examples 1-1 to 1-4, the operating temperature and recovery temperature decreased with increasing pressing pressure, reaching a minimum of -21.4°C for the operating temperature and -32.3°C for the recovery temperature. Under all conditions, the hysteresis could be narrowed to within a few degrees (deg).

[0132] [Example 2 (corresponding to the first embodiment)]

[0133] Except for setting the diameter L13 of the protrusion of the punch used in the second process to 1.2 mm, 3 mm, or 6.4 mm and varying the pressing force, the procedure was carried out under the same conditions as in Example 1. The diameter lengths L13 of 1.2 mm, 3 mm, and 6.4 mm are approximately 8%, approximately 20%, and approximately 43% of the diameter of the circumscribed circle, 14.9 mm, respectively. The results are shown in Table 1 as Examples 2-1 to 2-5. The temperature characteristics can be varied by adjusting the pressing force of the punch in the second process and the diameter L13 of the protrusion. Thus, by using a punch with a protrusion having a diameter of 1.2 mm, 3 mm, or 6.4 mm, a hysteresis of less than 10 degrees can be achieved.

[0134] [Example 3 (corresponding to the fifth embodiment)]

[0135] Bimetallic raw materials with holes of 2 mm in diameter were prepared, and the same experiments as in Example 1 were conducted. The results are also shown in Table 1 as Example 3. Even using bimetallic parts with holes, it is possible to produce bimetallic parts with extremely low temperature characteristics and narrow hysteresis of more than ten degrees (deg).

[0136] [Example 4 (corresponding to the third embodiment)]

[0137] The shape of the bimetallic part is set as follows: Figure 13A The bimetallic part was circular, with a diameter of 13 mm. Except for the shape of the bimetallic part, experiments were conducted under the same conditions as in Example 1, and the results are similarly shown in Table 1 (Example 4). Even with a circular shape for the bimetallic part, it is possible to manufacture a bimetallic part with extremely low temperature characteristics and a backlash of less than 10 degrees. Furthermore, the length L13 of the diameter of the end face of the protrusion X of the punch in the second process is 5 mm, which is approximately 38% of the diameter of the bimetallic part's 13 mm.

[0138] [Example 5 (corresponding to the second embodiment)]

[0139] The bimetallic raw material (with a low expansion layer of Ni-Fe alloy and a high expansion layer of Cu-Ni-Mn alloy) with a plate thickness of 0.15 mm is cut into... Figure 8 The bimetallic part is shown as a rounded quadrilateral. Its dimensions are 14mm × 10mm, with the four corners designed as curves with a radius of curvature of 3mm. The diameter of the circumscribed circle of this bimetallic part is 14.9mm. The bimetallic part and the die containing the punch and die are maintained at a temperature similar to room temperature.

[0140] As the first step, the bimetallic raw material is placed onto a die with a flat surface. A punch with a radius of curvature of 24 mm on its top surface is lowered and pressed against the bimetallic raw material with a force of approximately 100 kgf for about 1 second. At this point, the high-expansion layer of the bimetallic part becomes the punch side, and the low-expansion layer becomes the die side.

[0141] Next, as the second and final pressing step, the bimetallic part formed in the first step is placed onto a flat die, and a punch with a protrusion is lowered and pressed against the bimetallic part. At this point, the high-expansion layer of the bimetallic part becomes the punch side, and the low-expansion layer becomes the die side. The shape of the protrusion is... Figure 6 Similarly, the shape shown is such that the end face of protrusion X and end face Y are both planar, the length of the diameter L13 of the end face of protrusion X is set to 5 mm, the protrusion amount H is set to 0.3 mm, and the length of the diameter L14 of face Y is set to 15 mm. The length of the diameter L13 (5 mm) is approximately 34% of the diameter of the circumscribed circle, which is 14.9 mm. The pressing time is set to approximately 1 second, and after pressing, a heat treatment at 200°C is performed for 1 hour.

[0142] Table 1 shows the results of experiments conducted by varying the pressure of the second step as Examples 5-1 to 5-3. As the results show, with the operating temperature and recovery temperature above room temperature, the operating temperature and recovery temperature increased as the punch pressure increased in the second step, and a hysteresis of less than 10 degrees was obtained.

[0143] [Comparative Example 1]

[0144] Except that the diameter L13 of the punch protrusion used in the second process was set to 7.6 mm and the pressing was varied, the process was carried out under the same conditions as in Example 1. The diameter L13 (7.6 mm) is approximately 51% of the diameter of the circumscribed circle, which is 14.9 mm. The results are shown in Table 1 as Comparative Example 1. The bimetallic part produced under these conditions does not reverse via rapid motion, and the reversal temperature cannot be measured using a bimetallic part temperature checking device. It can be seen that when the protrusion of the punch (i.e., the boundary 123 of the bimetallic part) exceeds 50% of the diameter of the circumscribed circle, it will not reverse via rapid motion.

[0145] [Compare Examples 2 and 3]

[0146] The punch used in the second process had the same tip curvature radius of 24 mm as the punch used in the first process. In Comparative Example 2, in the first process, the low-expansion layer of the bimetallic part was made to be the punch side and the high-expansion layer to be the die side; in the second process, the high-expansion layer of the bimetallic part was made to be the punch side and the low-expansion layer to be the die side. In Comparative Example 3, in the first process, the high-expansion layer of the bimetallic part was made to be the punch side and the low-expansion layer to be the die side; in the second process, the low-expansion layer of the bimetallic part was made to be the punch side and the high-expansion layer to be the die side. Except for these and the change in pressing in the second process, experiments were conducted under the same conditions as in Example 1, and the results are similarly shown in Table 1 (Comparative Examples 2 and 3).

[0147] Even with changes in the direction of the bimetallic component, the operating and recovery temperatures remain largely unchanged, with a hysteresis exceeding 35 degrees. The cross-sectional structure of these bimetallic components at room temperature after inversion at temperatures below the recovery temperature is similar to... Figure 3 Similarly, the low-expansion layer also exhibits an upward-convex curve, but it is a single curve (not shown) rather than a composite curve. Furthermore, the cross-sectional structure after reversal at temperatures above the operating temperature is also a single curve (not shown), not a composite curve. Bimetallic parts with such a single-curve cross-sectional structure lack the freedom to set operating temperature, recovery temperature, and hysteresis, making it impossible to achieve a relatively narrow hysteresis setting of around 10 degrees.

[0148] As described above, according to embodiments of the present invention, it is possible to provide a thermal response element that can freely set the hysteresis over a wide temperature range, has a relatively small hysteresis of about 10 degrees, or an operating temperature and recovery temperature that are extremely low, below room temperature.

[0149] Furthermore, the embodiments described above can also be applied to thermal response elements other than bimetallic components such as shape memory alloys (below 100°C) and trimetallic components.

[0150] Regarding the implementation methods described so far, the following notes are disclosed.

[0151] [Postscript 1]

[0152] A thermally responsive element, which is plate-shaped and its shape changes with temperature.

[0153] The cross-section of the thermal response element at room temperature is a composite curve composed of multiple curves. The cross-sections at the center of the thermal response element and at the outer periphery surrounding the center are different curves.

[0154] When the temperature reaches a range outside the specified range of room temperature, the shape of the thermal response element changes.

[0155] The cross-section of the thermal response element after shape change is a composite curve composed of multiple curves. The cross-sections at the center of the thermal response element and at the outer periphery surrounding the center are different curves.

[0156] The boundary between the central portion and the outer periphery is the same before and after the shape change of the thermal response element.

[0157] [Postscript 2]

[0158] According to the thermal response element described in Appendix 1, wherein,

[0159] The thermally responsive element is a bimetallic component comprising a first metal layer and a second metal layer, wherein the second metal layer is located below the first metal layer and has a greater coefficient of thermal expansion than the first metal layer.

[0160] The specified temperature is a temperature lower than the room temperature.

[0161] At room temperature, the thermally responsive element has a shape in which the central portion protrudes downwards and the entire element convexes downwards.

[0162] The thermal response element after the shape change has a shape in which the central part protrudes upward and the whole is convex upward.

[0163] [Postscript 3]

[0164] According to the thermal response element described in Appendix 1, wherein,

[0165] The thermally responsive element is a bimetallic component comprising a first metal layer and a second metal layer, wherein the second metal layer is located below the first metal layer and has a greater coefficient of thermal expansion than the first metal layer.

[0166] The specified temperature is a temperature exceeding the room temperature.

[0167] At room temperature, the thermally responsive element has a shape in which the central portion protrudes upwards and the entire element is convex upwards.

[0168] The thermal response element after the shape change has a shape in which the central part protrudes downward and the whole is convex downward.

[0169] [Postscript 4]

[0170] According to any one of Appendices 1 to 3, the thermal response element, wherein,

[0171] The thermal response element has a rounded quadrilateral shape when viewed from above.

[0172] The boundary lies on the circumference of a concentric circle with a length of 1% to 50% of the diameter of the circumcircle of the rounded quadrilateral.

[0173] [Postscript 5]

[0174] According to any one of Appendices 1 to 3, the thermal response element, wherein,

[0175] The thermal response element is circular when viewed from above.

[0176] The boundary lies on the circumference of a concentric circle having a length of 1% to 50% of the diameter of the circle.

[0177] [Postscript 6]

[0178] A method for manufacturing a thermally responsive element as described in any one of Appendices 1 to 5, wherein,

[0179] The process includes shaping the raw material of the thermally responsive element through a multi-stage pressing process performed by a stamping machine.

[0180] In the final stage of the multi-stage pressing process, a metal punch with a protruding central portion and a die made of elastic material are used.

[0181] [Postscript 7]

[0182] A method for manufacturing a thermally responsive element as described in any one of Appendices 1 to 5, wherein,

[0183] The process includes pressing the raw material of the thermal response element by clamping it with upper and lower metal molds.

[0184] The embodiments of the present invention have been described above, but the present invention is not limited to the described embodiments and various modifications and alterations can be made based on the technical concept of the present invention.

[0185] Explanation of reference numerals in the attached figures

[0186] 100, 150, 200, 300, 400, 500, 600, 700, 800 bimetallic parts, 111, 211 low expansion layer

[0187] 112, 212 high expansion layer

[0188] 121, 221 Central Section

[0189] 122, 222 peripheral part

[0190] 123, 223 boundary

[0191] Circumcircles of 131 and 231

[0192] 151 Hole

[0193] Lengths of L1, L11, and L21

[0194] Lengths of L2, L12, and L22

[0195] P1 and P2 punches

[0196] D-die.

Claims

1. A thermally responsive element, which is plate-shaped and its shape changes with temperature, characterized in that, The cross-section of the thermal response element at room temperature is a composite curve composed of multiple curves. The cross-sections of the central portion and the outer periphery surrounding the central portion of the thermal response element are different curves. When the temperature reaches a range outside the specified range of room temperature, the shape of the thermal response element changes. The cross-section of the thermal response element after shape change is a composite curve composed of multiple curves. The cross-sections of the central portion and the outer periphery surrounding the central portion of the thermal response element are different curve shapes. The boundaries between the central portion and the outer periphery are the same before and after the shape change of the thermal response element.

2. The thermal response element according to claim 1, wherein, The thermally responsive element is a bimetallic component comprising a first metal layer and a second metal layer, wherein the second metal layer is located below the first metal layer and has a greater coefficient of thermal expansion than the first metal layer. The specified temperature is a temperature lower than the room temperature. At room temperature, the thermally responsive element has a shape in which the central portion protrudes downwards and the entire element convexes downwards. The thermal response element after the shape change has a shape in which the central part protrudes upward and the whole is convex upward.

3. The thermal response element according to claim 1, wherein, The thermally responsive element is a bimetallic component comprising a first metal layer and a second metal layer, wherein the second metal layer is located below the first metal layer and has a greater coefficient of thermal expansion than the first metal layer. The specified temperature is a temperature exceeding the room temperature. At room temperature, the thermally responsive element has a shape in which the central portion protrudes upwards and the entire element is convex upwards. The thermal response element after the shape change has a shape in which the central part protrudes downward and the whole is convex downward.

4. The thermal response element according to any one of claims 1 to 3, wherein, The thermal response element has a rounded quadrilateral shape when viewed from above. The boundary lies on the circumference of a concentric circle with a length of 1% to 50% of the diameter of the circumcircle of the rounded quadrilateral.

5. The thermal response element according to any one of claims 1 to 3, wherein, The thermal response element is circular when viewed from above. The boundary lies on the circumference of a concentric circle having a length of 1% to 50% of the diameter of the circle.

6. A method for manufacturing a thermally responsive element according to any one of claims 1 to 3, characterized in that, The process includes shaping the raw material of the thermally responsive element through a multi-stage pressing process performed by a stamping machine. In the final stage of the multi-stage pressing process, a metal punch with a protruding central portion and a die made of elastic material are used.

7. A method for manufacturing a thermally responsive element according to any one of claims 1 to 3, characterized in that, The process includes pressing the raw material of the thermal response element by clamping it with upper and lower metal molds.

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