JP2015152075A - Diaphragm valve structure and solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a diaphragm valve structure and a solenoid valve in which a stress generated at a diaphragm part can be reduced and durability of the diaphragm can be improved.SOLUTION: A diaphragm valve structure 30 comprises a column-shaped valve body part 4a abutted against or spaced apart from a valve seat 2c; a diaphragm part 4b extended outward from the valve body 4a and arranged; a diaphragm 4 including an outer edge part 4c arranged along an outer edge of the diaphragm part 4b to be thick and fixed between a valve body 2 and a stuffing 7; a shaft member 5 integrally arranged at the valve body part 4a to protrude from the center of a counter valve seat side end surface 4e of the valve body part 4a, having the extremity end arranged inside the valve body part 4a and adhered to the valve body part 4a so as to transmit driving force to the valve body part 4a. At least a portion of the counter valve seat side part from a position where the diaphragm part 4b is connected to the valve body 4a in the portions where the valve body part 4a and the shaft member 5 are contacted to each other is set to be non-adhered.

Description

  The present invention relates to a diaphragm valve structure and an electromagnetic valve that make a diaphragm contact or separate from a valve seat.

  Conventionally, for example, in medical devices, electromagnetic valves have been used to control chemical solutions such as hypochlorous acid and acetic acid for sterilization and cleaning. The solenoid valve employs a diaphragm valve structure in order to make the wetted part metal-free. Medical devices are becoming more compact, and the installation space for fluid control devices and the like is becoming narrower. Therefore, the solenoid valve is required to be downsized by reducing the diaphragm valve structure.

  FIG. 9 is a view showing a conventional diaphragm valve structure 100. The diaphragm valve structure 100 includes a diaphragm 102 that contacts or separates from a valve seat 101 provided in the valve chamber 106. Diaphragm 102 is formed of a corrosion-resistant and elastic material (for example, rubber such as fluoro rubber or ETFE (perfluoroelastomer), resin such as PTFE (polytetrafluoroethylene), or the like). The diaphragm 102 includes a cylindrical valve body portion 102a that contacts or separates from the valve seat 101, a thin film portion 102b that extends outward from the outer peripheral surface 102d of the valve body portion 102a, and an outer edge of the film portion 102b. An outer edge portion 102c is provided along the axial direction along the wall.

  In the diaphragm 102, a part of the membrane portion 102b and an outer edge portion 102c are sandwiched between the valve body 103 and the stuffing 104, thereby preventing the control fluid from leaking outside. A shaft member 105 made of a material (for example, resin, metal, etc.) that is more rigid than the diaphragm 102 is bonded to the valve body 102a. The diaphragm valve structure 100 controls the fluid by bringing the diaphragm 102 into contact with or separating from the valve seat 101 by transmitting driving force from an actuator (not shown) to the diaphragm 102 via the shaft member 105 (for example, Patent Document 1). reference).

JP 2000-193105 A

  However, in the conventional diaphragm valve structure 100, the contact portions of the valve body portion 102a and the shaft member 105 are all bonded to prevent the valve body portion 102a and the shaft member 105 made of different materials from being separated during the valve opening / closing operation. It was. Therefore, the valve body portion 102a is not deformed during the valve opening / closing operation and pulls the membrane portion 102b. The tensile stress generated in the film part 102b increased as the stroke increased. Therefore, in the conventional diaphragm valve structure 100, the stress generated in the membrane portion 102b during the valve opening / closing operation is large, and when the stroke increases, the stress concentrates on the portion P11 where the membrane portion 102b connects to the valve body portion 102a. Therefore, the film part 102b was easy to deteriorate.

  In particular, as described above, miniaturization of an electromagnetic valve applied to a medical device is progressing. When the diaphragm valve structure 100 is applied to this type of electromagnetic valve, a diaphragm 102 having a small maximum outer diameter (for example, about 5 mm) is used. In the small solenoid valve, since the valve chamber 106 is small and the distance between the inner peripheral surface 106a of the valve chamber 106 and the outer peripheral surface 102d of the valve body portion 102a is narrow, a diaphragm 102 having a flat membrane portion 102b is used. Is done. Therefore, the membrane portion 102b has a short membrane length L202 in the radial direction (distance from the portion connected to the valve body portion 102a to the portion connected to the outer edge portion 102c) (for example, about 3 mm). In order to secure a use stroke (for example, −1.10 mm or more and 0.30 mm or less) by the membrane portion 102b having the membrane length L202, the force with which the valve body portion 102a pulls the membrane portion 102b is inevitably increased. Therefore, in a small solenoid valve, the deterioration of the film part 102b becomes remarkable.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a diaphragm valve structure and an electromagnetic valve that can reduce the stress generated in the film portion and improve the durability of the diaphragm. And

One embodiment of the present invention has the following configuration.
(1) A diaphragm valve structure including a valve body including a valve seat, a diaphragm that contacts or separates from the valve seat, and a stuffing that fixes the diaphragm between the valve body, and the diaphragm includes: A cylindrical valve body portion that comes into contact with or separates from the valve seat, a membrane portion extending outward from the valve body portion, and a thickness provided along the outer edge of the membrane portion, the valve body An outer edge portion fixed between the valve body portion and the stuffing, and is provided integrally with the valve body portion so as to protrude from the center of the valve seat side end surface of the valve body portion. A tip portion disposed on the valve body portion, and having a shaft member that transmits a driving force to the valve body portion, and a portion of the valve body portion and the shaft member that are in contact with each other , At least the membrane part is the valve Hanben seat-side portion than a position connecting to the section, characterized in that a non-adhesive.

(2) In the configuration described in (1), preferably, the valve body portion has a constricted portion at a position where the pressure receiving surface of the membrane portion is connected.

(3) In the configuration described in (1) or (2), preferably, the valve body is provided outside the valve body storage chamber and a valve body storage chamber that stores the valve body portion, and the outer edge. An annular groove that accommodates the portion, and an annular convex portion that is disposed between the valve body housing chamber and the annular groove, and the gap between the stuffing and the annular convex portion is greater than the film thickness of the film portion. .

(4) a valve body in which the first port and the second port communicate with each other via a valve seat, a diaphragm that contacts or separates from the valve seat, and a stuffing that fixes the diaphragm between the valve body and An electromagnetic valve including a solenoid that generates a driving force according to the amount of current supplied to the coil and transmits the driving force to the diaphragm, wherein the diaphragm is in contact with or separated from the valve seat; and the valve A membrane portion extending outward from the body portion; and an outer edge portion that is thickly provided along an outer edge of the membrane portion and is fixed between the valve body and the stuffing, the valve body The valve body part is integrally provided so as to protrude from the center of the counter valve seat side end surface of the part, and a tip part disposed inside the valve body part is bonded to the valve body part, The solenoid is generated A shaft member for transmitting the driving force to the valve body portion, and at least a portion of the portion where the valve body portion and the shaft member are in contact with each other at a position opposite to the valve seat side from a position where the film portion is connected to the valve body portion This part is non-adhesive.

  The diaphragm valve structure configured as described above is configured such that the diaphragm is fixed at the outer edge portion between the valve body and the stuffing, and the valve body portion is bonded to the distal end portion of the shaft member to which the driving force is applied. The body and stuffing are hermetically separated by a membrane. The diaphragm valve structure performs fluid control by contacting or separating the valve body portion from the valve seat while deforming the membrane portion.

  Here, in the diaphragm valve structure, at least the portion on the side opposite to the valve seat from the position where the membrane portion is connected to the valve body portion is non-adhered among the portions where the valve body portion and the shaft member are in contact with each other. Therefore, the diaphragm is deformed so that the non-adhered portion with respect to the shaft member is expanded in the direction away from the shaft member as the valve body portion moves toward the valve seat side. In other words, the vicinity of the end face on the side opposite to the valve seat of the valve body part is deformed as if it is a part of the film part. Therefore, the tensile stress of the film part is relaxed. Therefore, according to the diaphragm valve structure having the above-described configuration, the stress generated in the membrane portion of the diaphragm can be reduced and the durability of the diaphragm can be improved.

  By the way, when the pressure receiving diameter of the diaphragm increases, the actuator for applying a driving force to the diaphragm increases in size. In order to reduce the pressure receiving diameter of the diaphragm, it is conceivable to reduce the valve chamber that houses the valve body. If the valve chamber is made too small, the film length of the membrane part (the length from the inner diameter position connecting to the valve body part of the membrane part to the outer edge connection position connecting to the outer edge part) becomes shorter, and the stress generated in the film part Becomes excessive.

  When the valve chamber is made small while ensuring the film length of the film part, a part of the film part is disposed between the valve body and the stuffing, and the deformation of the film part when the valve is opened is limited by the stuffing. In this case, the film portion has a short movable film length (a length from the inner diameter position to a restriction position where deformation is restricted by contacting the stuffing), and it is difficult to secure a stroke. Therefore, there is a limit to reducing the pressure receiving diameter of the diaphragm by reducing the valve chamber.

  On the other hand, according to the diaphragm valve structure having the above-described configuration, the valve body portion has a constricted portion in the portion connected to the membrane portion, and the inner diameter position of the membrane portion connected to the valve body portion is shifted in the axial direction. Therefore, the film length of the film part and the movable film length become long without changing the size of the valve chamber. In addition, as is well known, since the valve body portion is arranged in the center of the diaphragm, the inner diameter dimension (diameter of the inner diameter position) and the outer diameter dimension (diameter of the restriction position) of the movable membrane length are added by 2. The pressure receiving diameter can be calculated by dividing. In the diaphragm valve structure having the above-described configuration, the inner diameter position of the membrane portion is shifted in the axial direction by the constricted portion, so that the diameter of the inner diameter position of the membrane portion is reduced, and is calculated by the calculation method of the pressure receiving diameter of the diaphragm. The pressure receiving diameter is reduced.

  Therefore, according to the diaphragm valve structure having the above-described configuration, by providing the constricted portion in the valve body portion, it is possible to lengthen the membrane length and the movable membrane length to reduce the stress generated in the membrane portion, and to reduce the pressure receiving diameter of the diaphragm. .

  According to the diaphragm valve structure having the above configuration, the valve body includes a valve body storage chamber that stores the valve body portion of the diaphragm, an annular groove that is provided outside the valve body storage chamber and stores the outer edge portion of the diaphragm, When the diaphragm is fixed between the valve body and the stuffing, it has an annular projection arranged between the chamber and the annular groove, and the gap between the stuffing and the annular projection is larger than the film thickness of the membrane portion. The membrane part is not crushed between the valve body and the stuffing. For this reason, the membrane part entirely deforms from the outer edge connecting position connected to the outer edge to the inner diameter position during the valve opening / closing operation. Therefore, according to the diaphragm valve structure having the above-described configuration, it is possible to disperse stress over the entire membrane portion during the valve opening / closing operation, and to improve the durability of the diaphragm.

  Since the solenoid valve having the above-described configuration is configured in the same manner as the above-described diaphragm valve structure, it is possible to reduce the stress acting on the film portion and improve the durability of the diaphragm as in the above-described diaphragm valve structure. In particular, in a small solenoid valve used in a medical device, for example, the maximum outer diameter of the diaphragm is small. As described above, the tensile stress generated in the membrane portion can be reduced by deforming the valve body portion, or the movable membrane length can be reduced. If it is possible to secure a use stroke by extending the length of the film and to disperse the stress throughout the film part by not crushing the film part, a use stroke can be ensured while reducing the stress generated in the film part even with a small diaphragm. Moreover, since the fluid pressure acting on the diaphragm is reduced by reducing the pressure receiving diameter, the solenoid can be made smaller and the solenoid valve can be made more compact.

It is sectional drawing of the solenoid valve which concerns on embodiment of this invention. It is a figure which shows the principal part of the diaphragm valve structure shown in FIG. 1, Comprising: A valve closed state is shown. The fully open state of FIG. 2 is shown. It is a figure explaining the general pressure receiving diameter calculation method of a diaphragm with a convolution. It is a conceptual diagram which shows the relationship between the pressure receiving diameter and stroke of a diaphragm with a convolution. It is a figure which shows the simulation result of the film part shape in the moment of valve closing. It is a figure which shows a stress analysis result, Comprising: The magnitude of a stress value is shown on a vertical axis | shaft, and the magnitude of a stroke is shown on a horizontal axis. In the figure, ♦ indicates the relationship between the maximum stress value generated in the film part of the example and the stroke, and in the figure indicates the relationship between the maximum stress value generated in the film part of the comparative example and the stroke. It is a figure which shows a stress analysis result, Comprising: The magnitude | size of a tension | tensile_strength is shown on a vertical axis | shaft, and the magnitude of a stroke is shown on a horizontal axis | shaft. In the figure, ♦ indicates the relationship between the maximum tension generated in the film part of the example and the stroke, and in the figure indicates the relationship between the maximum tension generated in the film part of the comparative example and the stroke. It is a figure which shows the valve structure of the conventional diaphragm valve.

  Hereinafter, an embodiment of a diaphragm valve structure according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a solenoid valve 1 according to an embodiment of the present invention. FIG. 2 is a view showing a main part of the diaphragm valve structure 30 shown in FIG. 1 and showing a valve closed state. FIG. 3 shows the fully opened state of FIG. FIG. 4 is a diagram for explaining a general pressure receiving diameter calculation method for a convolution diaphragm. FIG. 5 is a conceptual diagram showing the relationship between the pressure receiving diameter and the stroke of the diaphragm with convolution. FIG. 6 is a diagram showing a simulation result of the shape of the membrane part at the moment when the valve is closed. FIG. 7 is a diagram showing a stress analysis result, in which the vertical axis indicates the magnitude of the stress value and the horizontal axis indicates the magnitude of the stroke. In the figure, ♦ indicates the relationship between the maximum stress value generated in the film part 4b of the example and the stroke, and in the figure indicates the relationship between the maximum stress value generated in the film part 102b of the comparative example and the stroke. FIG. 8 is a diagram showing the results of stress analysis, in which the vertical axis indicates the magnitude of the tension and the horizontal axis indicates the magnitude of the stroke. In the figure, ♦ indicates the relationship between the maximum tension generated in the film part 4b of the example and the stroke, and in the figure indicates the relationship between the maximum tension generated in the film part 102b of the comparative example and the stroke.

  In the following description, first, a schematic configuration of the electromagnetic valve 1 to which the diaphragm valve structure 30 of the present embodiment is applied will be described with reference to FIG. 1, and then the main part of the diaphragm valve structure 30 will be described with reference to FIGS. 2 and 3. After that, the operation and effect of the electromagnetic valve 1 and the diaphragm valve structure 30 will be described with reference to FIGS. Then, after explaining the concept of the pressure receiving diameter with reference to FIGS. 4 to 6, stress comparison results between the example and the comparative example will be described with reference to FIGS. 7 and 8.

  The solenoid valve 1 is used, for example, in a medical device and controls a chemical solution such as hypochlorous acid or acetic acid. In the solenoid valve 1, a solenoid 10 is attached to a valve body 2 via a stuffing 7. The cover 20 is formed of a nonmagnetic material and is attached so as to cover the solenoid 10 and the stuffing 7. The electromagnetic valve 1 controls the fluid by bringing the diaphragm 4 into contact with or separating from the valve seat 2c by the driving force applied from the solenoid 10 to the shaft member 5. The electromagnetic valve 1 includes a diaphragm valve structure 30 for reducing the stress of the diaphragm 4.

  The valve body 2 and the stuffing 7 are made of a corrosion-resistant material such as a fluororesin. In the valve body 2, a first port 2a and a second port 2b communicate with each other via a valve seat 2c. The diaphragm 4 is made of rubber, resin, or the like having corrosion resistance and elasticity, and is fixed between the valve body 2 and the stuffing 7.

  In order to make the solenoid valve 1 small, a diaphragm 4 having a small maximum outer diameter (for example, a maximum outer diameter of 5 mm) is used. Therefore, the diaphragm 4 cannot be directly connected to the solenoid 10. Therefore, the diaphragm 4 is integrally provided with a shaft member 5 made of metal or hard resin by insert molding or the like, and constitutes the diaphragm assembly 3.

  The solenoid 10 has a coil 11 wound around a coil bobbin 12 having a hollow hole 12a. The solenoid 10 has a fixed iron core 13 fixed to the upper end opening of the hollow hole 12a, and a movable iron core 14 is slidably loaded from the lower end opening of the hollow hole 12a. The coil 11 is covered with a magnetic cover 15 and a magnetic plate 16 so that a magnetic path for the fixed iron core 13 to attract the movable iron core 14 is easily formed.

  The movable iron core 14 is penetrated by the magnetic plate 16, and the tip portion projects toward the stuffing 7 side. A magnetic member 17 is disposed between the movable iron core 14 and the magnetic plate 16, and a magnetic path is formed from the magnetic plate 16 to the lower end portion of the movable iron core 14. A flange portion 14 c is provided at the lower end of the movable iron core 14. The first compression spring (first urging member) 18 is contracted between the flange portion 14c and the magnetic member 17, and constantly urges the movable iron core 14 in the valve seat direction.

  The lower end portion of the movable iron core 14 and the first compression spring 18 are accommodated in an opening 7a provided on the solenoid side end surface 7d of the stuffing 7 so as to be displaceable. In the stuffing 7, the shaft member 5 is passed through an insertion hole 7c provided coaxially with the opening 7a. The bottom wall of the opening 7a is provided with a boss 7b at the opening of the insertion hole 7c, and is guided by the boss 7b so that the shaft member 5 can stably reciprocate linearly along the axis.

  The shaft member 5 protrudes upward from the solenoid-side end face 7d of the stuffing 7 with the diaphragm 4 in contact with the valve seat 2c. The second compression spring (second urging member) 9 is inserted into the shaft member 5 so as to abut against a spring receiving stepped portion 7e (see FIG. 2) provided on the end face of the boss portion 7b, and is fixed to the shaft member 5. By attaching the ring 8, the ring 8 is contracted between the retaining ring 8 and the spring receiving step part 7 e. Therefore, the shaft member 5 is always urged in the counter valve seat direction by the second compression spring 9. Here, since the retaining ring 8 is attached to the outer peripheral surface of the portion protruding from the solenoid side end surface 7d when the valve is closed, the shaft member 5 is subjected to the second compression when the valve body 2, the diaphragm assembly 3, and the stuffing 7 are assembled in this order. The spring 9 can be easily attached to the shaft member 5.

  The movable iron core 14 has an opening 14a on the valve seat side end surface. The distal end portion of the shaft member 5 and the second compression spring 9 are disposed inside the storage hole portion 14a. The spring force of the second compression spring 9 is smaller than the spring force of the first compression spring 18. Therefore, when the coil 11 is not energized, the first compression spring 18 depresses the movable iron core 14 against the second compression spring 9, and pushes the shaft member 5 in the valve seat direction at the bottom surface 14b of the housing hole portion 14a, thereby the diaphragm 4 Is in contact with the valve seat 2c. As described above, since the second compression spring 9 is compressed when the valve is closed, when the coil 11 is energized, the second compression spring 9 expands as the movable core 14 rises, and the shaft member 5 is retracted into the housing hole. Continue to press against the bottom surface 14b of 14a. That is, the solenoid valve 1 is assembled so that the shaft member 5 and the movable iron core 14 are always in contact with no gap.

  For this reason, in the electromagnetic valve 1, the movable iron core 14, the stuffing 7, the shaft member 5, and the diaphragm 4 are assembled without a gap, and the diaphragm 4 contacts or separates from the valve seat 2c with good responsiveness according to the driving force of the solenoid 10. . Therefore, the solenoid valve 1 does not need to select a solenoid 10 having a size larger than that required for the use stroke in consideration of rattling that occurs between components, and the solenoid 10 is made compact to reduce the overall size. It is possible to plan.

  The storage hole portion 14a is fitted to the boss portion 7b so that the inner peripheral surface is in sliding contact with the outer peripheral surface of the boss portion 7b. Therefore, the movable iron core 14 is supported by the boss portion 7 b at the lower end where the spring force of the first and second compression springs 18 and 9 acts strongly, and can move stably in the axial direction without contacting the magnetic member 17. .

  Next, the main part of the diaphragm valve structure 30 shown in FIG. 2 will be described.

  The diaphragm 4 is made of a corrosion-resistant and elastic rubber or resin. The diaphragm 4 has a valve body part 4a that contacts or separates from the valve seat 2c, a thin film part 4b extending outward from the valve body part 4a, and a wall thickness in the axial direction along the outer edge of the film part 4b. Provided with an outer edge portion 4c fixed between the valve body 2 and the stuffing 7. The valve body portion 4a has a substantially cylindrical shape. The film part 4b is provided with the same film thickness in the radial direction along the outer periphery of the valve body part 4a, and is formed in a ring shape. The film part 4b is extended from the valve body part 4a so as to be orthogonal to the axial direction at the time of manufacture, and is formed in a flat shape. The outer edge portion 4c is provided thicker than the film portion 4b in order to prevent fluid leakage by being crushed between the valve body 2 and the stuffing 7.

  The valve body 2 includes a valve body storage chamber 2d that stores the valve body portion 4a, an annular groove 2e that is provided outside the valve body storage chamber 2d and stores the outer edge portion 4c, a valve body storage chamber 2d, and an annular groove 2e. An annular convex portion 2f disposed between the two. The diaphragm valve structure 30 is configured such that the diaphragm 4 is mounted on the valve body 2 so that the outer edge portion 4c is mounted in the annular groove 2e, and the fitting convex portion 7f protruding from the stuffing 7 is provided in the fitting concave portion 2g of the valve body 2. By fitting together and fixing the valve body 2 and the stuffing 7, the outer edge portion 4c is crushed and fixed in the axial direction between the bottom wall of the fitting concave portion 2g and the lower end surface of the fitting convex portion 7f. As a result, the membrane portion 4b airtightly partitions between the valve body storage chamber 2d of the valve body 2 and the back pressure chamber forming recess 7g of the stuffing 7 so that the control fluid leaks from the valve chamber 21 to the back pressure chamber 22. prevent.

  The shaft member 5 is provided integrally with the valve body portion 4a so as to protrude from the center of the counter valve seat side end surface 4e of the valve body portion 4a. The shaft member 5 is formed narrower than the seal diameter between the valve body portion 4a and the valve seat 2c in order to make the connecting structure around the first and second compression springs 18 and 9 compact.

  In order to increase the contact area with the valve body portion 4a and prevent the displacement of the valve body portion 4a, the shaft member 5 has the flesh of the valve body portion 4a in the concave groove 5a formed along the outer peripheral surface of the tip portion. . The shaft member 5 is provided with a large-diameter portion 5b larger in diameter than the seal surface at the tip of the groove 5a so that the sealing force is uniform in the circumferential direction of the valve seat 2c.

  In order to reduce the volume of the back pressure chamber 22, the valve body portion 4 a is provided with a small diameter portion 4 d in which the portion on the side opposite to the valve seat is smaller in diameter than the portion connected to the membrane portion 4 b. The small diameter portion 4d has substantially the same diameter as that of the shaft member 5, and the driving force is efficiently transmitted from the shaft member 5 to the valve body portion 4a.

  The distal end portion of the shaft member 5 is bonded to the valve body portion 4a. Adhesion is performed for the purpose of always contacting the shaft member 5 and the valve body portion 4a during the valve opening / closing operation so that the valve body portion 4a operates with good responsiveness. If this purpose is achieved, it is not necessary to bond all the portions where the shaft member 5 and the valve body 4a are in contact. On the other hand, the diaphragm 4 can relieve the tensile stress generated in the membrane portion 4b if the valve body portion 4a is deformed by being pulled by the membrane portion 4b during the valve opening operation.

  Therefore, in the diaphragm 4, it is preferable that at least the portion on the side opposite to the valve seat from the position where the membrane portion 4 b is connected to the valve body portion 4 a in the portion where the valve body portion 4 a and the shaft member 5 are in contact with each other. Furthermore, it is preferable that at least the portion on the side opposite to the valve seat from the position where the pressure receiving surface 4f of the membrane portion 4b is connected to the valve body portion 4a is not adhered. In other words, it is preferable that the diaphragm 4 adheres any one of the portions where the valve body portion 4a and the shaft member 5 are in contact with each other from the portion where the membrane portion 4b is connected to the valve body portion 4a. Furthermore, it is preferable to adhere any one of the parts on the valve seat side from the position where the pressure receiving surface 4f of the film part 4b is connected to the valve body part 4a.

  In the present embodiment, among the portions where the valve body portion 4a and the shaft member 5 are in contact, only the portion where the valve seat side end surface 5c of the large diameter portion 5b is in contact with the valve body portion 4a is bonded. Therefore, the valve body portion 4a is non-adhered at the portion that contacts the outer peripheral surface of the tip end portion of the shaft member 5 (the inner wall of the concave groove 5a and the outer peripheral surface of the large diameter portion 5b).

  The valve body portion 4a has a constricted portion 4g at a position where the pressure receiving surface 4f of the membrane portion 4b is connected. The valve body portion 4a is narrowed at the constricted portion 4g so that the thickness of the portion where the constricted portion 4g is formed is approximately the same as the thickness of the small diameter portion 4d. This is because the pressure receiving surface 4f and the back pressure surface 4h of the membrane portion 4b during the valve opening / closing operation disperse the stress generated in the portion connected to the valve body portion 4a, thereby smoothly deforming the valve body portion 4a.

  In order to reduce the size of the electromagnetic valve 1, the diaphragm valve structure 30 is configured such that the inner peripheral surfaces of the valve body storage chamber 2d and the back pressure chamber forming recess 7g are disposed on the membrane portion 4b, and the valve chamber 21 and the back pressure chamber 22 The volume is reduced. The annular convex portion 2f is provided in a ring shape having the same width in the radial direction. The annular convex portion 2f is projected higher than the bottom wall of the annular groove 2e so as to form a gap S1 between the annular convex portion 2f and the fitting convex portion 7f.

  When the gap S1 is smaller than the film thickness of the film part 4b, the film part 4b is crushed between the annular convex part 2f and the fitting convex part 7f. In this case, the squeezed portion cannot be deformed during the valve opening / closing operation, and only the portion disposed in the valve chamber 21 is deformed, so that the stress increases and the membrane portion 4b is likely to deteriorate. Therefore, it is preferable that the gap S1 between the annular convex portion 2f and the fitting convex portion 7f is larger than the film thickness of the film portion 4b. However, if the gap S1 is too large, the membrane portion 4b is deformed by the fluid pressure during the valve opening / closing operation, and the pressure receiving diameter is increased. The larger the pressure receiving diameter, the larger the solenoid 10 needs to be, which is a problem in making the solenoid valve 1 compact. Therefore, the gap S1 between the annular convex part 2f and the fitting convex part 7f prevents the film part 4b from curving convexly toward the valve seat side, while the film part 4b is connected to the valve body part 4a. It is preferable that the expansion and contraction with the outer edge portion 4c is allowed.

  Then, the effect of the solenoid valve 1 and the diaphragm valve structure 30 is demonstrated.

  As shown in FIG. 1, when the solenoid 10 is not energized, the solenoid valve 1 causes the valve body portion 4a to be moved to the valve seat 2c via the shaft member 5 by the differential pressure of the first and second compression springs 18 and 9. The fluid is not caused to flow from the first port 2a to the second port 2b.

  When the valve is closed, as shown in FIG. 2, the diaphragm valve structure 30 is slightly inclined so that the membrane portion 4b is in surface contact with the annular convex portion 2f within the gap S1. The membrane portion 4b is provided with the constricted portion 4g in the valve body portion 4a, so that the inner diameter position is shifted in the axial direction, and the movable region that can be deformed is wider than when the constricted portion 4g is not provided. Therefore, the diaphragm 4 can make the valve body part 4a contact | abut to the valve seat 2c, without bringing a wrinkle to the film | membrane part 4b.

  When the solenoid 10 is energized to the solenoid 10, the fixed iron core 13 attracts the movable iron core 14 against the first compression spring 18. At this time, the second compression spring 9 extends and pushes up the shaft member 5 toward the valve seat side. Thereby, the shaft member 5 separates the valve body portion 4a from the valve seat 2c, and the fluid flows from the first port 2a to the second port 2b.

  In this valve opening operation, the diaphragm valve structure 30 is characterized by the deformation of the diaphragm 4. That is, when the valve body portion 4a starts to rise from the valve closed state, the membrane portion 4b expands and contracts across the entire membrane length L2 from the inner diameter position connected to the valve body portion 4a to the outer edge portion connection position connected to the outer edge portion 4c. In this manner, the posture comes into surface contact with the fitting convex portion 7f from the posture in surface contact with the annular convex portion 2f.

  Thereafter, when the valve body portion 4a is further raised, the membrane portion 4b is formed at the corner portion 7h between the inner wall of the back pressure chamber forming concave portion 7g and the valve seat side end surface of the fitting convex portion 7f as shown in FIG. Deforms so that it can be bent. That is, in the film part 4b, the part outside the part in contact with the corner part 7h is pressed against the lower end surface of the fitting convex part 7f and cannot be deformed, and only the part inside the part in contact with the corner part 7h is warped. The valve seat is deformed (hereinafter, the position at which the film portion 4b contacts the corner portion 7h is referred to as a restriction position).

  As described above, the membrane portion 4b can be deformed in the counter valve seat direction from the inner diameter position to the outer edge connection position before contacting the corner portion 7h. Only the position to the limit position can be deformed in the counter valve seat direction. That is, in the film portion 4b, the movable region after contacting the corner portion 7h is narrower than the movable region before contacting the corner portion 7h. When the movable region is narrowed, the valve body portion 4a tries to pull the membrane portion 4b strongly.

  However, in the diaphragm 4, only the portion where the valve seat side end surface 5 c of the shaft member 5 contacts the valve body portion 4 a among the contact portions between the shaft member 5 and the valve body portion 4 a is bonded, and the other portions are bonded. Not. Therefore, after the membrane portion 4b contacts the corner portion 7h, the valve body portion 4a starts to deform in a direction away from the shaft member 5, as indicated by a two-dot chain line in the figure. Therefore, the diaphragm 4 is deformed as if the valve body portion 4a is a part of the membrane portion 4b, and the tensile stress generated in the membrane portion 4b is relaxed.

  At this time, the valve body portion 4a is provided with a small diameter portion 4d and a constricted portion 4g so that the valve seat side and the counter valve seat side of the portion connected to the membrane portion 4b have substantially the same thickness. Therefore, when pulled by the membrane portion 4b, the upper end portion of the valve body portion 4a is smoothly deformed. Therefore, the diaphragm 4 does not hinder the valve opening / closing operation even if the valve body 4a is deformed during the valve opening / closing operation.

  By the way, when the pressure receiving diameter of the diaphragm increases, the actuator for applying a driving force to the diaphragm increases in size. In order to reduce the pressure receiving diameter of the diaphragm, for example, as shown in FIG. 9, it is conceivable to reduce the valve chamber 106 that houses the valve body portion 102a. If the valve chamber 106 is made too small, the membrane length L202 of the membrane portion 102b (the length from the inner diameter position connecting to the valve body portion to the outer edge portion connecting position connecting to the outer edge portion) of the membrane portion 102b is shortened. Excessive stress is generated.

  When the valve chamber 106 is made small while securing the film length of the film part 102b, a part of the film part 102b is disposed between the valve body 103 and the stuffing 104, and the deformation of the film part 102b when the valve is opened is the stuffing 104. Limited by. In this case, the film part 102b has a short movable film length L201 (a length from the inner diameter position to a restriction position where deformation is restricted by contacting the stuffing), and it is difficult to secure a stroke. Therefore, there is a limit to reducing the pressure receiving diameter of the diaphragm 102 by reducing the valve chamber 106.

  On the other hand, as shown in FIG. 2, in the diaphragm valve structure 30, the constricted portion 4g is provided in the valve body portion 4a, and the position where the membrane portion 4b is connected to the valve body portion 4a does not provide the constricted portion 4g. In some cases, it is shifted in the axial direction. Therefore, the film portion 4b has a longer length (movable film length) L1 from the inner diameter position to the restriction position than when the constricted portion 4g is not provided. The longer the movable film length L1, the longer the stroke can be secured. That is, with the same use stroke, the longer the movable film length L1, the more the tensile stress generated in the film part 4b can be reduced. Therefore, the diaphragm 4 can reduce the tensile stress of the film part 4b compared with the thing which does not have the constriction part 4g.

  It is considered that the pressure receiving diameter increases as the movable film length L1 increases. However, as will be described later, since the diaphragm valve structure 30 of the present embodiment can reduce the pressure receiving diameter while increasing the movable film length L1, it is necessary to enlarge the solenoid 10 even if the movable film length L1 is increased. Absent.

  By the way, like the diaphragm valve structure 100 shown in FIG. 9, when a part of the film part 102b is crushed between the valve body 103 and the stuffing 104, the film part 102b expands and contracts the crushed part. I can't. Therefore, the membrane portion 102b performs the valve opening / closing operation by deforming only the region corresponding to the movable membrane length L201. Therefore, as the stroke increases, the portion connected to the valve body portion 102a or the portion where deformation is restricted Stress tends to concentrate on

  On the other hand, in the diaphragm valve structure 30 shown in FIG. 2 and FIG. 3, the membrane portion 4b is fitted to the annular convex portion 2f at a portion outside the restriction position where deformation is restricted by contacting the corner portion 7h. Expansion and contraction are allowed without being crushed between the convex portions 7f. Therefore, the film portion 4b is stretched at a portion outside the limit position as the stroke increases. Therefore, the diaphragm valve structure 30 can improve the durability of the diaphragm 4 because the stress is dispersed throughout the film portion 4b even if the stroke becomes large.

  When the energization of the solenoid 10 is stopped, the movable iron core 14 is lowered by the differential pressure between the first and second compression springs 18 and 9. The movable iron core 14 pushes down the shaft member 5 to bring the valve body portion 4a into contact with the valve seat 2c. Thereby, the fluid does not flow from the first port 2a to the second port 2b.

  At the start of the valve closing operation, the diaphragm valve structure 30 is deformed toward the shaft member 5 side by the elastic force of the valve body portion 4a as shown by the solid line in FIG. Further, the membrane portion 4b shrinks the portion outside the limit position while deforming the portion inside the limit position to the valve seat side. When the film part 4b is separated from the corner part 7h, the entire film length L2 is deformed. Then, as shown in FIG. 2, the membrane part 4b comes into surface contact with the annular convex part 2f and is inclined obliquely, and the diaphragm 4 is in a valve-closed state.

  Here, the fluid pressure acts on the membrane part 4b at the moment of valve opening operation, valve closing operation, and valve closing. The film part 4b is not squeezed by the valve body 2 and the stuffing 7, and is in a state where the part outside the restricting position can always be expanded and contracted. Further, in the membrane portion 4b, the constricted portion 4g is provided in the valve body portion 4a, so that the movable membrane length L1 from the inner diameter position to the restriction position is increased. Therefore, the diaphragm valve structure 30 bends the movable region from the inner diameter position of the membrane portion 4b to the restriction position in a convex shape toward the counter valve seat while the fluid pressure acts on the membrane portion 4b. It looks like a convolution. Also from this point, the film portion 4b has a long movable film length L1, and the stress generated during the valve opening / closing operation is reduced.

  Next, the pressure receiving diameter of the diaphragm 4 will be considered. If it says from a conclusion, the diaphragm 4 can consider a pressure receiving diameter and a function similarly to the effective diameter Df of the diaphragm 51 with a convolution shown in FIG.

  In the convolution diaphragm 51 shown in FIG. 4, the effective diameter Df is calculated by adding the outer diameter Dc of the convolution 53 and the inner diameter Dp of the convolution, and dividing the added value by two. [Df = (Dc + Df) / 2].

  As shown in FIG. 5, the convolution diaphragm 51 has an effective diameter as the stroke increases as shown in an effective diameter DfA of the fully closed position SA, an effective diameter DfC of the intermediate position SC, and an effective diameter DfB of the fully opened position SB. There is a feature that becomes smaller.

  The inventors analyzed the diaphragm 4 of the present embodiment to examine the relationship between the stroke and the pressure receiving diameter.

  As a result of this analysis, it was found that the diaphragm 4 has a smaller pressure receiving diameter Df1 as the stroke becomes larger. This is the same characteristic as the effective diameter Df of the convolution diaphragm 51 shown in FIG.

  Inventors analyzed the shape of the film | membrane part 4b when a fluid pressure acted. As a result, when the fluid pressure is applied at the moment of closing the valve, the membrane portion 4b has a movable region from the inner diameter position connected to the valve body portion 4a to the restricted position contacting the corner portion 7h, as shown in FIG. It turned out to bend and deform in a convex shape toward the counter valve seat side. In addition, an analysis result was obtained that deformed the shape of the membrane portion 4b on which the fluid pressure acts during the valve opening operation in the same manner as the membrane portion 4b at the moment of closing the valve.

  Therefore, the diaphragm 4 has a shape in which the membrane portion 4b is convexly curved toward the counter valve seat between the inner diameter position and the restriction position while the fluid pressure is applied, and a convolution is provided. In this case, the diameter Dp1 of the inner diameter position shown in FIG. 2 corresponds to the inner diameter dimension Dp of the convolution 52 of the convolution diaphragm 51 shown in FIG. 4, and the diameter Dc1 of the restriction position shown in FIG. 2 is shown in FIG. This is considered to correspond to the outer diameter Dc of the convolution 52 of the diaphragm 51 with convolution.

  Therefore, when the diaphragm condition assumed in the analysis for examining the relationship between the stroke and the pressure receiving diameter is applied to the effective diameter calculation formula of the convolution diaphragm, the analysis is performed when the calculated pressure receiving diameter Dp1 is 0 mm stroke (valve closed state). It was comparable to the pressure receiving diameter obtained as a result. Therefore, the pressure receiving diameter of the diaphragm 4 can be considered in the same manner as the diaphragm 51 with convolution, and can be obtained by an effective diameter calculation formula of the diaphragm 51 with convolution.

  As described above, the diaphragm 4 has an inner diameter dimension according to the effective diameter calculation formula of the convolution diaphragm 51 even if the constricted portion 4g is provided in the valve body portion 4a and the movable membrane length L1 of the membrane portion 4b is increased. Since Dp (the diameter Dp1 at the inner diameter position) is reduced, the pressure receiving diameter can be reduced.

  Next, the stress generated in the diaphragm valve structure 30 shown in FIG. 2 and the diaphragm valve structure 100 shown in FIG. 9 will be described.

  Here, the stress was analyzed about the Example which has the structure similar to the diaphragm valve structure 30, and the comparative example which has the structure similar to the diaphragm valve structure 100. FIG. The example and the comparative example have the same shape except for the following first to third differences.

  The first difference is that the embodiment partially bonds the contact portion between the shaft member 5 and the valve body portion 4a, whereas the comparative example bonds the entire contact portion between the shaft member 105 and the valve body portion 102a. It is. The second difference is that the example has a constricted portion 4g, whereas the comparative example does not have a constricted portion. The third difference is that the diaphragm 4 is fixed in a state in which the embodiment does not crush the membrane portion 4b, whereas the diaphragm 102 is fixed in a state in which the membrane portion 102b is crushed in the comparative example.

  In the stress analysis, the maximum stress value and the maximum tensile stress value applied to the film portions 4b and 102b are investigated when the fluid pressure is applied and the example and the comparative example are operated from the minimum stroke position to the maximum stroke position, respectively. It was.

  As shown in FIG. 7, it was found that the maximum stress value applied to the film part 4b of the example was smaller than the maximum stress value applied to the film part 102b of the comparative example including the use stroke range.

  Further, as shown in FIG. 8, the maximum tensile stress value applied to the film part 4b of the example is smaller than that of the comparative example in almost the entire region of the use stroke range. In particular, the difference between the maximum tensile stress values of the example and the comparative example becomes more prominent as the stroke increases.

  In the use stroke range, the change rate of the maximum tensile stress value is moderate in the example, and the film portion 4b can be used without wrinkling. On the other hand, in the comparative example, the rate of change of the maximum tensile stress value was large in the use stroke range, and the film portion 102b was wrinkled near the minimum stroke of the use stroke.

  From the above, it was found that in the example, the maximum stress and tensile stress generated in the film part 4b are reduced compared to the film part 102b of the comparative example. Therefore, the embodiment can reduce the stress generated in the film part 4 b and improve the durability of the diaphragm 4.

  When the tension of the film part 4b is increased, the force for moving the diaphragm 4 is increased. Therefore, it is necessary to increase the size of the coil 11 (solenoid 10). However, if the tension of the film part 4b is reduced as in the embodiment, the force for moving the diaphragm 4 becomes smaller than that in the comparative example, and the size of the coil 11 (solenoid 10) can be reduced as compared with the comparative example.

In addition, this invention is not limited to the said embodiment, Various application is possible.
For example, the diaphragm valve structure of the above embodiment may be applied to an air operated valve that performs fluid control according to the balance between the operating pressure and the spring pressure. Even in this case, the pressure receiving diameter of the diaphragm can be reduced by providing a constriction in the valve body portion of the diaphragm, so that the actuator portion can be made smaller and the air operated valve can be made more compact.

DESCRIPTION OF SYMBOLS 1 Solenoid valve 2 Valve body 2a 1st port 2b 2nd port 2c Valve seat 2d Valve body storage chamber 2e Annular groove 2f Annular convex part 4 Diaphragm 4a Valve body part 4b Film part 4c Outer edge part 4e Counter valve seat side end face 4f Pressure receiving surface 4g Constriction 5 Shaft member 7 Staffing 10 Solenoid 11 Coil 30 Diaphragm valve structure

Claims (4)

In a diaphragm valve structure including a valve body including a valve seat, a diaphragm that contacts or separates from the valve seat, and a stuffing that fixes the diaphragm between the valve body,
The diaphragm is provided with a thickness along the outer edge of the membrane portion, a cylindrical valve body portion that contacts or separates from the valve seat, a membrane portion that extends outward from the valve body portion, and the membrane portion. An outer edge portion fixed between the valve body and the stuffing,
The valve body part is provided integrally with the valve body part so as to protrude from the center of the counter valve seat side end surface of the valve body part, and a tip part disposed inside the valve body part is bonded to the valve body part And having a shaft member for transmitting a driving force to the valve body part,
A diaphragm valve structure characterized in that at least a portion on the side opposite to the valve seat from a position where the membrane portion is connected to the valve body portion is non-adhered among the portions where the valve body portion and the shaft member are in contact with each other. In the diaphragm valve structure according to claim 1,
A diaphragm valve structure, wherein the valve body portion has a constricted portion at a position where the pressure receiving surface of the membrane portion is connected. In the diaphragm valve structure according to claim 1 or 2,
The valve body includes a valve body storage chamber that stores the valve body portion, an annular groove that is provided outside the valve body storage chamber and stores the outer edge portion, and the valve body storage chamber and the annular groove. Having an annular protrusion disposed between,
A diaphragm valve structure characterized in that a distance between the stuffing and the annular convex part is larger than a film thickness of the film part. A valve body in which a first port and a second port communicate with each other via a valve seat; a diaphragm that contacts or separates from the valve seat; a stuffing that fixes the diaphragm between the valve body; and a coil In a solenoid valve having a solenoid that generates a driving force according to the amount of energization and transmits the driving force to the diaphragm,
The diaphragm is provided with a thickness along the outer edge of the membrane portion, a cylindrical valve body portion that contacts or separates from the valve seat, a membrane portion that extends outward from the valve body portion, and the membrane portion. An outer edge portion fixed between the valve body and the stuffing,
The valve body part is provided integrally with the valve body part so as to protrude from the center of the counter valve seat side end surface of the valve body part, and a tip part disposed inside the valve body part is bonded to the valve body part And having a shaft member for transmitting the driving force generated by the solenoid to the valve body part,
Among the portions where the valve body portion and the shaft member are in contact, at least the portion on the side opposite to the valve seat from the position where the membrane portion is connected to the valve body portion is non-adhered.

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