Diaphragm

Abstract

The purpose of the present invention is to provide an easily designed diaphragm that satisfies required member strength such as corrosion resistance, pressure resistance, and durability while maintaining deformability. The diaphragm (47) separates an operating chamber (48e) through which a fluid flows from a housing space (10a) different from the operating chamber (48e). The diaphragm (47) is provided with a first member (47a) provided on the working chamber (48e) side and a second member (47b) provided on the housing space (10a) side. The first member (47a) has a predetermined corrosion resistance with respect to at least the fluid. The second member (47b) is made of a material different from that of the first member (47a). The first member (47a) and the second member (47b) are laminated separately from each other.

Description

Technical Field

[0001] This invention relates to diaphragms. Background Technology

[0002] Conventionally, diaphragms have been used as partitions to divide predetermined spaces (for example, see Patent Document 1). The diaphragm described in Patent Document 1 separates the space where fluid is introduced (the working chamber) from the space housing a pair of metal terminals that switch between on and off states by the movement of a working shaft. The diaphragm causes the working shaft to move axially by deforming or displacing, thereby switching the on and off states of the pair of metal terminals, thus requiring constant deformability (flexibility).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Utility Model Authorization No. 3226571 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, in the aforementioned diaphragms, when it is desired to improve the diaphragm's intended durability for repeated use (in the case of repeated use, this refers to the length of time it can maintain its function as a diaphragm, hereinafter referred to as durability), for example, it is considered to set the plate thickness to a certain extent. However, in this case, the rigidity of the diaphragm increases, making it difficult to increase the amount of displacement of the diaphragm (deformability decreases), and making it difficult to adequately ensure the stroke of the working shaft that moves with the displacement of the diaphragm. On the other hand, it is considered to improve the deformability of the diaphragm by reducing the plate thickness, changing the material, etc., but in this case, the pressure resistance tends to decrease. Furthermore, when the fluid in contact with the diaphragm is a corrosive fluid, the materials that can be used are also limited. Therefore, the freedom in selecting materials and setting the plate thickness for the required deformability is small, and it is not easy to design a diaphragm that meets the required component strengths such as corrosion resistance, pressure resistance, and durability while maintaining deformability.

[0008] The purpose of this invention is to provide an easily designed diaphragm that meets the required component strengths such as corrosion resistance, pressure resistance, and durability while maintaining deformability.

[0009] Solution for solving the problem

[0010] In order to solve the above-mentioned problems and achieve the purpose, the diaphragm of the present invention is a diaphragm that separates a fluid space in which fluid flows from other spaces that are different from the fluid space. It is characterized by having a first component disposed on the fluid space side and a second component disposed on the other space side. The first component has a predetermined corrosion resistance at least relative to the fluid. The second component is made of a different material from the first component. The first component and the second component are stacked separately from each other.

[0011] According to this invention, by separately stacking the first and second components, the stress generated during diaphragm deformation can be generated separately in the first and second components. Therefore, when the first and second components undergo the same deformation, the ratio of stress generated in the first and second components can be appropriately set. This increases the freedom in selecting the materials and setting the plate thickness of the first and second components corresponding to the separately generated stresses. Furthermore, according to this structure, for example, even when the deformability of the first component, which has excellent corrosion resistance, is improved by reducing its plate thickness as described above, by setting the stress generated in the second component to be greater than the stress generated in the first component, the overall component strength of the diaphragm can be achieved to the desired strength, thereby contributing to improved diaphragm durability. Therefore, a diaphragm that is easy to design can be provided that meets the required component strengths such as corrosion resistance, pressure resistance, and durability while maintaining deformability.

[0012] Furthermore, it is preferable that the rigidity of the second component is greater than that of the first component. With this structure, by making the rigidity of the second component greater than that of the first component, the first component deforms more easily than the second component when both components undergo the same deformation. This reduces the stress generated in the first component, thereby making it easier to ensure pressure resistance through the second component.

[0013] Furthermore, it is preferable that the first component is made of a Ni-based alloy. According to this structure, by using a Ni-based alloy, which is generally highly corrosion-resistant, to construct the first component, the required corrosion resistance can be achieved more easily. It should be noted that Ni-based alloys are typically expensive, in addition to having low machinability. Therefore, in this structure, compared to the second component, the first component has lower deformability and machinability, and higher manufacturing costs. However, as described above, in this invention, by setting a larger stress in the second component, the overall component strength of the diaphragm can be made to the desired strength, thus easily reducing the amount of the first component used. Therefore, reducing the amount of the first component can suppress the deterioration of the diaphragm's machinability and contribute to reducing the manufacturing cost of the diaphragm.

[0014] Furthermore, it is preferable that the second component is made of precipitation-hardening stainless steel. According to this structure, by using precipitation-hardening stainless steel, which is typically of high strength, to construct the second component, the required durability (fatigue strength) can be achieved more easily.

[0015] Furthermore, it is preferable that the thickness of the second component is greater than that of the first component. According to this structure, by making the thickness of the second component greater than that of the first component, the amount of typically expensive, highly corrosion-resistant materials used can be reduced. Additionally, it is easier to make the rigidity of the second component greater than that of the first component. Therefore, when the first and second components undergo the same deformation, the stress generated in the second component can be greater than the stress generated in the first component.

[0016] Invention Effects

[0017] According to the present invention, an easily designed diaphragm can be provided that meets the required component strengths such as corrosion resistance, pressure resistance, and durability while maintaining deformability. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view showing a pressure switch with a diaphragm according to one embodiment of the present invention.

[0019] Figure 2 yes Figure 1 An enlarged sectional view of region A in the diagram. Detailed Implementation

[0020] The following is based on Figures 1 to 2 Embodiments of the present invention will be described. The pressure switch 100 is a device that detects changes in the pressure of a detected object by switching the on / off state of its terminals according to changes in the pressure of the detected object. In this embodiment, the pressure switch 100 is configured as a normally closed switch. This normally closed switch detects a controlled fluid flowing in the flow path 62 described later. It is in an on / off state when the pressure of the controlled fluid is below a predetermined pressure, and in a non-conducting state when the pressure of the controlled fluid is above the predetermined pressure. Furthermore, in the accompanying drawings, the vertical and horizontal directions correspond to the vertical and horizontal directions of the pressure switch 100. These definitions of directions are merely for ease of explanation and do not limit the actual orientation of the pressure switch 100 in its actual use.

[0021] The pressure switch 100 includes a micro switch 1, a working part 40, a cover part 50, and a connector part 60. The micro switch 1 includes a main body 10 having an internal storage space 10a (a space other than the fluid space). The main body 10 is formed into a covered cylindrical shape with a downward opening. A first metal terminal 11 and a second metal terminal 12 made of conductive metal material are mounted on the top 10b of the main body 10. The first metal terminal 11 is formed by bending a flat metal material into an L-shape, and has a longitudinal plate part 11a along the axis L of the working shaft 44 (described later) and a transverse plate part 11b intersecting the longitudinal plate part 11a. The upper end of the longitudinal plate part 11a is inserted through the top 10b of the main body 10 and protrudes to the outside. The transverse plate part 11b extends to the left from the lower end of the longitudinal plate part 11a and is stored in the storage space 10a. A fixed contact 20 made of conductive material is provided at the left end of the transverse plate part 11b.

[0022] The second metal terminal 12 has a plate surface facing the right side (towards the first metal terminal 11) and is formed as a flat plate extending along the axis L. The upper end of the second metal terminal 12 is inserted through the top 10b of the main body 10 and protrudes outwards, while the lower end is housed within the main body 10. A movable contact plate 30 electrically connected to the second metal terminal 12 is provided at the lower end of the second metal terminal 12. The movable contact plate 30 is a contact member capable of contacting and separating relative to the fixed contact 20. In this embodiment, the movable contact plate 30 is formed into an L-shape by bending a plate member having conductivity facing the first metal terminal 11 towards the first metal terminal 11. The longitudinal portion 30a of the movable contact plate 30 along the axis L is fixed to the second metal terminal 12 and extends along the plate surface of the second metal terminal 12. The lower end of the longitudinal portion 30a is bent toward the inside of the main body 10, and a leaf spring portion 30b extending toward the first metal terminal 11 is formed in this bent portion. The leaf spring portion 30b is capable of elastic deformation along the axis L, starting from the aforementioned curved portion. A downwardly curved bearing portion 30c is formed at the center of the leaf spring portion 30b in the left-right direction. The upper end of the working shaft 44, described later, contacts and separates from the bearing portion 30c.

[0023] A movable contact 30d, capable of contacting and separating from the fixed contact 20, is installed at the front end of the leaf spring portion 30b. The movable contact 30d is located above the fixed contact 20 and is opposed to the fixed contact 20 in the axial direction L. The movable contact 30d operates normally when the pressure of the controlled fluid is below a predetermined pressure. Figure 1In the state shown, the movable contact 30d abuts against the fixed contact 20. In this state, the leaf spring portion 30b is elastically deformed and tilted upwards towards the first metal terminal 11, and applies force to the movable contact 30d toward the fixed contact 20 by means of a force to restore it to its state before elastic deformation. As a result, under normal conditions, the pressure switch 100 connects the first metal terminal 11 and the second metal terminal 12 via the fixed contact 20 and the movable contact 30d.

[0024] A first expanded diameter portion 10c and a second expanded diameter portion 10d, which are continuous with the lower end of the first expanded diameter portion 10c and expand radially outward, are formed at the lower end of the inner periphery of the main body portion 10. A working portion 40 is provided on the lower side of the microswitch 1 configured in this way. The working portion 40 has a guide member 41 that is embedded in the inner peripheral surface of the main body portion 10. The guide member 41 is formed as a cover to close the opening of the main body portion 10. A flange 42 that protrudes radially outward is formed on the outer peripheral surface of the guide member 41, and the upward-facing surface of the flange 42 abuts against the downward-facing surface of the first expanded diameter portion 10c. A guide hole 43 that extends along the axis L is formed in the center of the guide member 41, and a working shaft 44 is inserted into the guide hole 43. The working shaft 44 is formed as a rod extending along the axis L. The outer diameter of the working shaft 44 is slightly smaller than the inner diameter of the guide hole 43, so that the working shaft 44 is guided by the guide hole 43 to move forward and backward along the axis L during movement. The upper end of the working shaft 44 can contact and separate from the bearing portion 30c of the leaf spring portion 30b. Figure 1 In the state shown, due to the weight of the working shaft 44, the lower end of the working shaft 44 abuts against the center of the upper surface of the diaphragm 47, which will be described later.

[0025] Through this structure, the working shaft 44 can transmit the reverse displacement of the diaphragm 47 (described later) to the movable contact plate 30 of the micro switch 1. A top cover 45 is provided on the lower side of the guide member 41. The top cover 45 is formed as a cover to close the opening of the main body 10. The diameter of the top cover 45 is larger than the inner diameter of the second expanded diameter portion 10d, and the outer peripheral portion of its upper surface abuts against the lower end face of the main body 10. An opening 45a extending along the axis L is formed in the center of the top cover 45, and the lower end of the working shaft 44 is inserted into the opening 45a. The central portion of the top cover 45 is inclined upwards towards the opening 45a, and the deformation and displacement of the diaphragm 47 (described later) are suppressed to a predetermined degree on the lower surface of this inclined portion. That is, in addition to closing the opening of the main body 10, the top cover 45 also functions as a limiting member to suppress the deformation of the diaphragm 47 to a predetermined degree.

[0026] An O-ring 46 is provided between the guide member 41 and the upper cover 45. The O-ring 46 is flattened by being sandwiched between the guide member 41 and the upper cover 45, becoming a generally flat ring shape, and is disposed within the second expanded diameter portion 10d. The upper surface of the O-ring 46 is in close contact with the lower surface of the flange 42 of the guide member 41, and the lower surface of the O-ring 46 is in close contact with the upper surface of the upper cover 45. Through these close contacts, the guide member 41 and the upper cover 45 are sealed. A diaphragm 47 is provided on the lower side of the upper cover 45. Details about the diaphragm 47 will be described later. A lower cover 48 is provided on the lower side of the diaphragm 47. The lower cover 48 has a flange portion 48a that abuts against the lower surface of the diaphragm 47, an inclined surface 48b that is inclined radially inward about the axis L from the inner end of the flange portion 48a toward the lower side, and a base plate portion 48c that extends orthogonally to the axis L from the lower end of the inclined surface 48b.

[0027] A mounting hole 48d, extending along the axis L, is formed in the center of the base plate 48c, and a connector component 60 is installed in the mounting hole 48d. With the connector component 60 installed in the mounting hole 48d, a working chamber 48e (fluid space) surrounded by the diaphragm 47, the lower cover 48, and the connector component 60 is formed inside the lower cover 48. Thus, the working part 40, consisting of the guide component 41, the upper cover 45, the O-ring 46, the diaphragm 47, and the lower cover 48, is integrated with the micro switch 1 via the cover component 50. The cover component 50 is a component that houses and connects the micro switch 1 and the working part 40, and is formed into a bottomed cylindrical shape by the base plate 51 and the side plate 52. The upper surface of the base plate 51 abuts against the bottom surface of the flange portion 48a in the lower cover 48, thereby supporting the working part 40 upward as a whole.

[0028] A through hole 51a extending along the axis L is formed in the center of the base plate 51, and the inclined surface 48b of the lower cover 48 is embedded in the through hole 51a. The side plate 52 extends along the axis L, and its inner surface covers the outer surface of the main body 10, the outer surface of the upper cover 45, the outer surface of the diaphragm 47, and the outer surface of the lower cover 48. The upper end 52a of the side plate 52 is riveted to a stepped portion 10e formed on the outer peripheral surface of the main body 10. Through this riveting, the micro switch 1 is connected to the working part 40. In this state, the O-ring 46 is compressed along the axis L by the lower surface of the flange 42 of the guide member 41 and the upper surface of the upper cover 45. In addition, in this state, the diaphragm 47 functions as a partition separating the storage space 10a of the main body 10 from the working chamber 48e in the working part 40.

[0029] A connector component 60 is provided on the lower side of the working part 40. The connector component 60 is formed as a cylinder extending along the axis L. A small diameter portion 61 with a smaller diameter than the rest of the connector component 60 is formed at the upper end of the connector component 60. The small diameter portion 61 is joined to the lower cover 48 by brazing, welding or the like when inserted into the mounting hole 48d of the lower cover 48. A flow path 62 for the flow of controlled fluid for the object being tested is formed inside the connector component 60, and the flow path 62 communicates with the working chamber 48e. Through this communication, the flow path 62 and the working chamber 48e are at the same pressure. In addition, in this embodiment, the connector component 60 is made of a cylindrical component, but it is not limited to this example. It may also be a metal processing component of any shape formed by stamping, cutting, die casting, forging or the like, connected to a pipe that guides the controlled fluid for the object being tested.

[0030] In this pressure switch 100 configuration, when the pressure of the controlled fluid flowing in the flow path 62 is normally below a predetermined pressure, the central portion of the diaphragm 47 is recessed downwards. In this state, the upper end of the working shaft 44 does not abut against the receiving portion 30c of the movable contact plate 30. Furthermore, in this state, the movable contact 30d abuts against the fixed contact 20, and the first metal terminal 11 and the second metal terminal 12 are in a conductive state. When the pressure of the controlled fluid rises from this conductive state to above the predetermined pressure, the central portion of the diaphragm 47 reverses its displacement, becoming convex upwards. Through this reverse displacement of the diaphragm 47, the upper end of the working shaft 44 abuts against the receiving portion 30c, and the leaf spring portion 30b of the movable contact plate 30 is pushed upwards via the receiving portion 30c. This upward push continues until the upper surface of the diaphragm 47 abuts against the central portion of the lower surface of the upper cover 45.

[0031] By pushing upwards, the leaf spring portion 30b elastically deforms upwards from the aforementioned curved portion, resulting in the movable contact 30d separating from the fixed contact 20. This separation causes the first metal terminal 11 and the second metal terminal 12 to become non-conductive. Furthermore, when the pressure of the controlled fluid drops below a predetermined pressure from this non-conductive state, the diaphragm 47 reverses its displacement again, becoming concave in the center, and the working shaft 44 separates from the bearing portion 30c. This separation returns the leaf spring portion 30b to its state before elastic deformation, and the pressure switch 100 returns to its normal state. Through this action, the pressure switch 100 detects changes in the pressure of the detected object based on the conducting and non-conductive states of the first metal terminal 11 and the second metal terminal 12.

[0032] Next, the diaphragm 47 will be described. For example... Figure 2 As shown, the diaphragm 47 is a partition that divides the space within the pressure switch 100 into a working chamber 48e (fluid space) and a receiving space 10a (other space), restricting the intrusion of the controlled fluid into the receiving space 10a. Figure 2 As shown, the diaphragm 47 includes a first component 47a disposed on the lower side and a second component 47b disposed on the upper side. The first component 47a is a first diaphragm disposed on the working chamber 48e side and in contact with the controlled fluid, and is formed as an integral circular plate (disc) extending about the axis L. Here, the type of controlled fluid in contact with the first component 47a varies depending on the application; for example, sometimes a predetermined chemical, acidic fluid, water, seawater, corrosive oil, or other corrosive controlled fluid is used. Therefore, the first component 47a is configured to have the required predetermined corrosion resistance at least to these corrosive fluids.

[0033] The predetermined corrosion resistance refers to the length of time during which the diaphragm 47 can maintain its function when repeatedly used in the presence of a controlled fluid. For example, it can be determined based on whether the corrosion rate shown during the period of use is within an acceptable range. Therefore, the predetermined corrosion resistance is set such that during the use of the pressure switch 100, the diaphragm 47 can maintain its function as a partition while also maintaining its ability to transmit its displacement and deformation to the movable contact plate 30 via the working shaft 44. Furthermore, the predetermined corrosion resistance of the first component 47a is more preferably set to be higher than that of the second component 47b. Specifically, for example, when the corrosive controlled fluid is a predetermined pharmaceutical product or an acidic fluid, the first component 47a is preferably made of a Ni-based alloy, a predetermined stainless steel, or the like. Ni-based alloys are generally materials with excellent corrosion resistance; examples include Inconel (registered trademark) and Hastelloy (registered trademark).

[0034] The Inconel and Hastelloy materials exhibit high resistance to corrosion, particularly to the intended pharmaceuticals and acidic fluids. For Inconel, Inconel 600, Inconel 601, Inconel 625, and Inconel 690 are particularly preferred. For Hastelloy, Hastelloy C22 and Hastelloy C276 are particularly preferred. On the other hand, the intended stainless steel exhibits high resistance to corrosion, particularly to water, seawater, and corrosive oils. For this stainless steel, SUS316 or SUS316 L are particularly preferred.

[0035] The first component 47a includes a first body 47a1 formed in a shape that protrudes downward from its center in normal operation, and a first clamping portion 47a2 extending radially outward from the outer periphery of the first body 47a1. The first body 47a1 is formed in a shape where its center is located at the lowest side in normal operation. The first clamping portion 47a2 is a portion clamped by a flange portion 48a of the lower cover 48 and a second component 47b, with the upper surface of the flange portion 48a abutting against the bottom surface of the first clamping portion 47a2. The second component 47b is a second diaphragm disposed on the side of the storage space 10a, formed separately from the first component 47a in a shape substantially the same as the first component 47a, and having multiple pieces stacked on the upper side relative to the first component 47a. The second component 47b includes a second body 47b1 extending along the first body 47a1 about an axis X2, and a second clamping portion 47b2 extending radially outward from the outer periphery of the second body 47b1.

[0036] A working shaft 44 is centrally contacted on the upper surface of the second body 47b1. The second body 47b1 is arranged and stacked in a manner that does not engage with the first body 47a1. Alternatively, in this structure, for example, it may be configured such that a gap in the axial direction L is created between the first body 47a1 and the second body 47b1, and between the second body 47b1 and each other. The diaphragm 47 thus configured deforms from normal operation by causing the first body 47a1 to shift upwards as the pressure in the flow path 62 and the working chamber 48e increases. Furthermore, the second body 47b1 is deformed by pressing against the deformed first body 47a1, causing the pressed portion to shift upwards. Through this displacement and deformation, the working shaft 44, which abuts against the second body 47b1, is pushed out and moves upwards.

[0037] It should be noted that when the diaphragm 47 deforms in this way, as described above, the first body 47a1 and the second body 47b1 deform in the same manner, but the first body 47a1 and the second body 47b1 do not join together and become separate parts. Therefore, the first body 47a1 and the second body 47b1 deform independently, and the stress generated during the deformation of the diaphragm 47 is generated separately in the first component 47a and the second component 47b. Here, the second component 47b, unlike the first component 47a, does not come into contact with the controlled fluid. That is, the second component 47b does not require the same level of corrosion resistance as the first component 47a. On the other hand, the first component 47a is configured to have predetermined corrosion resistance as described above, but in this case, its durability, such as fatigue strength, is affected not only by the shape of the first component 47a but also by the physical properties of the first component 47a. Moreover, corrosion resistance and strength (e.g., yield stress) are usually a trade-off, so there is a tendency for the strength of the first component 47a to decrease easily. That is, the stress that the first component 47a can tolerate is easily reduced.

[0038] In this embodiment, the diaphragm 47, which requires repeated deformation for the forward and backward movement of the working shaft 44 in the direction of axis L, leads to reduced durability and is therefore undesirable. For example, one could consider increasing the allowable stress of the first component 47a by increasing its plate thickness A1, but this would reduce the deformability of the first component 47a compared to before increasing the plate thickness A1. In this case, the stroke (displacement) of the working shaft 44 pushed out by the second component 47b via the first component 47a is limited. In this case, the switching between the conducting and non-conducting states may not be smooth, which is also undesirable. Therefore, in this invention, by making the rigidity of the second component 47b, which is not in contact with the controlled fluid, greater than the rigidity of the first component 47a, the first component 47a is made more easily deformable than the second component 47b, and the pressure resistance is easily ensured by the second component 47b.

[0039] Specifically, the second component 47b is preferably configured such that its stiffness (bending stiffness), expressed as Young's modulus × moment of inertia, is higher than that of the first component 47a. As a method to make the stiffness of the second component 47b higher than that of the first component 47a, it is sufficient to set the material and plate thickness A2 of the second component 47b to be greater than the stiffness obtained by the product of the Young's modulus and the plate thickness A1 of the first component 47a (Young's modulus × moment of inertia). For example, if the Young's modulus of the material used in the second component 47b is smaller than that of the first component 47a, such as... Figure 2 As shown, the thickness A2 of each second component 47b is greater than the thickness A1 of the first component 47a. Alternatively, multiple second components 47b can be considered as a single second component 47b, making the total thickness of the second components 47b greater than the thickness of the first component 47a. Conversely, when the Young's modulus of the material used in the second component 47b is greater than that of the first component 47a, based on the difference in Young's modulus between the first component 47a and the second component 47b, even if the thickness A2 of the second component 47b is thinner than the thickness A1 of the first component 47a, the rigidity of the second component 47b can still be greater than that of the first component 47a. Rigidity is represented by Young's modulus × moment of inertia of section; therefore, using a material with a large Young's modulus makes it easier to increase the rigidity of the second component 47b, and correspondingly, it can suppress the increase in thickness A2 (making thickness A2 thinner). The thinner the thickness A2, the less material is used, thus reducing costs. As described above, by increasing the rigidity of the second component 47b, the overall pressure resistance of the diaphragm 47 can be easily ensured by the second component 47b.

[0040] As a material that easily increases rigidity, all stainless steels other than those listed above can be used. More specifically, the second component 47b is more preferably made of precipitation-hardening stainless steel with high strength. By making the material of the second component 47b a high-strength material, the strength (fatigue strength) of the second component 47b under repeated deformation is improved, thus contributing to the improvement of the durability of the diaphragm 47. In addition, at this time, as Figure 2 As shown, for example, by setting the plate thickness A2 of the second component 47b to be greater than the plate thickness A1 of the first component 47a, the rigidity of the second component 47b can be further improved compared to the rigidity of the first component 47a, which is therefore more preferable.

[0041] Therefore, by combining the first component 47a and the second component 47b, the required component strengths such as corrosion resistance, pressure resistance, and durability can be achieved while maintaining deformability. Furthermore, in this combination, for example, compared to a structure where the diaphragm 47 is formed from a single material, the necessity for the first component 47a to reduce component strengths such as pressure resistance and durability due to improved corrosion resistance is reduced, and the necessity for the second component 47b to reduce corrosion resistance due to improved pressure resistance and durability is reduced. Therefore, the freedom in selecting the materials for the first component 47a and the second component 47b, as well as setting the plate thicknesses A1 and A2, is increased. Thus, it is easier to maintain the deformability of the diaphragm 47 while simultaneously achieving the required component strengths such as corrosion resistance, pressure resistance, and durability. It should be noted that the aforementioned Ni-based alloys, used as materials constituting the first component 47a, are generally not only poorly machinable but are sometimes also relatively expensive. However, according to this structure, for example, the plate thickness A1 of the first component 47a can be easily reduced, thereby reducing the amount of the first component 47a used. Therefore, it is possible to suppress the deterioration of the processability of the diaphragm 47 and reduce manufacturing costs.

[0042] According to the above embodiment, by separately stacking the first component 47a and the second component 47b, the stress generated when the diaphragm 47 deforms can be generated in the first component 47a and the second component 47b respectively. Therefore, when the first component 47a and the second component 47b undergo the same deformation, the ratio of the stress generated in the first component 47a and the second component 47b can be appropriately set. As a result, the freedom in selecting the materials of the first component 47a and the second component 47b corresponding to the separately generated stresses, as well as the setting of plate thicknesses A1 and A2, can be increased. Moreover, according to this structure, for example, even if the deformability of the first component 47a, which has excellent corrosion resistance, is improved by reducing its plate thickness A1, etc., as described above, by setting the stress generated in the second component 47b to be greater than the stress generated in the first component 47a, the overall component strength of the diaphragm 47 can be made to the desired strength, thereby contributing to the improvement of the durability of the diaphragm 47. Therefore, an easily designed diaphragm 47 can be provided that meets the required component strengths such as corrosion resistance, pressure resistance, and durability while maintaining deformability.

[0043] Furthermore, according to the above embodiment, by making the rigidity of the second component 47b greater than that of the first component 47a, when the first component 47a and the second component 47b undergo the same deformation, the first component 47a is easier to deform than the second component 47b. Therefore, the stress generated in the first component 47a can be reduced, and the compressive strength can be easily ensured by the second component 47b.

[0044] Furthermore, according to the above embodiment, by constructing the first component 47a from a Ni-based alloy, which is generally a material with high corrosion resistance, the required corrosion resistance can be achieved more easily. It should be noted that, generally, Ni-based alloys are not only difficult to process but are sometimes also expensive. Therefore, it is considered that, in this structure, compared to the second component 47b, the first component 47a has lower deformability and processability, and higher manufacturing costs. However, as described above, in this invention, by setting a larger stress generated in the second component 47b, the overall component strength of the diaphragm 47 can be made to the desired strength, thus making it easier to reduce the amount of the first component 47a used. Therefore, reducing the amount of the first component 47a used can suppress the deterioration of the processability of the diaphragm 47 and contribute to reducing the manufacturing cost of the diaphragm 47.

[0045] Furthermore, according to the above embodiment, by using precipitation-hardening stainless steel of generally high strength to construct the second component 47b, the required durability (fatigue strength) can be achieved more easily.

[0046] Furthermore, according to the above embodiment, by making the plate thickness A2 of the second component 47b greater than the plate thickness A1 of the first component 47a, the amount of material with high corrosion resistance, which is usually very expensive, can be reduced. Additionally, it is easier to make the rigidity of the second component 47b greater than that of the first component 47a. Therefore, when the first component 47a and the second component 47b undergo the same deformation, the stress generated in the second component 47b can be greater than the stress generated in the first component 47a.

[0047] Furthermore, the embodiments described above merely illustrate representative aspects of the present invention, and the present invention is not limited thereto. For example, in this embodiment, it is preferable that the second component 47b is made of a material with higher rigidity than the first component 47a made of Inconel or the like, and that the plate thickness A2 of the second component 47b is set to be greater than the plate thickness A1 of the first component 47a. However, for example, if a suitable material possessing the required deformability, corrosion resistance, or component strength is available, the second component 47b may be made of a material with higher rigidity than the first component 47a, and the plate thickness A2 may be the same as the plate thickness A1. Alternatively, in this case, the plate thickness A2 may be set to be less than the plate thickness A1.

[0048] Furthermore, the materials constituting the first component 47a and the second component 47b of the diaphragm 47 are not limited to metallic materials. Considering the aforementioned deformability, corrosion resistance, or component strength, various materials such as resin, rubber, and glass can be used. Additionally, various materials can be combined to construct the first component 47a and the second component 47b. Furthermore, in this embodiment, one first component 47a and multiple second components 47b are used, but this is not a limitation; multiple first components 47a or one second component 47b can be used. That is, one or more first components 47a and second components 47b can be used interchangeably. Moreover, when multiple first components 47a and second components 47b are used respectively, if the thickness A2 of the second component 47b is greater than the thickness A1 of the first component 47a, multiple first components 47a can be considered as one first component 47a, and multiple second components 47b can be considered as one second component 47b. In this case, the total thickness of the second component 47b can also be set to be greater than the total thickness of the first component 47a.

[0049] In this embodiment, the pressure switch 100 is exemplified as a normally closed switch, but it is not limited to this. The diaphragm 47 can also be applied to various pressure switches, such as normally open pressure switches that are normally non-conductive. Furthermore, besides pressure switches, the diaphragm 47 can also be applied to valve devices that form part of a refrigeration cycle, etc. Specifically, the diaphragm 47 can also be applied to electric valves or solenoid valves equipped with an electromagnetic coil, mechanical expansion valves that function as throttling devices, and mechanical pressure regulating valves that drive pressure-sensing components connected to valve components based on pressure changes. In this case, the diaphragm 47 can, for example, be used as a component that deforms or displaces upon receiving pressure changes in the fluid to drive the valve core.

[0050] Symbol Explanation

[0051] 10a—Storage space (other spaces); 48e—Workshop (fluid space); 47—Diaphragm; 47a—First component; 47b—Second component.

Claims

1. A diaphragm that separates a fluid space from other spaces different from the fluid space, characterized in that, have: The first component, which is disposed on the fluid space side; and The second component is located on the other space side mentioned above. The aforementioned first component possesses at least a predetermined corrosion resistance relative to the aforementioned fluid. The second component is made of a different material than the first component. The first component and the second component are stacked separately from each other.

2. The diaphragm according to claim 1, characterized in that, The rigidity of the second component is greater than that of the first component.

3. The diaphragm according to claim 2, characterized in that, The first component mentioned above is made of a Ni-based alloy.

4. The diaphragm according to claim 2, characterized in that, The second component mentioned above is made of precipitation-hardening stainless steel.

5. The diaphragm according to claim 1, characterized in that, The thickness of the second component is greater than that of the first component.

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