JP5439029B2 - Bellows valve - Google Patents

Description

  The present invention relates to a bellows valve that opens and closes a flow path, for example, interposed in a transport pipe for various liquids in the food industry, the pharmaceutical industry, and the like.

  In general, a valve interposed between various liquid transportation pipes in the food industry and the pharmaceutical industry has a valve operating shaft in order to prevent leakage and microbial contamination from a shaft passing portion through the wall of the valve case. The shaft passing part is sealed with a stretchable stem sheet such as a bellows or diaphragm, and when the valve operating shaft requires a long stroke, a bellows valve that can secure a large amount of expansion and contraction of the stem sheet is used. ing.

  As the bellows in the conventional bellows valve, various materials such as synthetic resin such as fluororesin, rubber, metal, etc. are adopted. The directional cross section has a shape in which S-shaped bending is continuously repeated (Patent Document 1).

JP 2008-32219 A

  However, in the conventional bellows valve, in particular, in the configuration in which the valve operating shaft is arranged in the vertical direction, the bellows also has a vertical cylindrical shape. Therefore, the peripheral wall bent in a continuous S shape in the contracted state of the bellows when the valve is opened or closed As the degree of bending increases, the inner back side of each groove portion of the bellows is lower than the outer edge side, and liquid pool is likely to occur. Therefore, for example, in the transportation piping of sanitary plants that handle liquid foods, beverages, chemicals, etc., it is common to perform steam sterilization by periodically flowing saturated heating steam, but at this time in the contracted bellows groove There is a problem in that water vapor condenses to form a puddle, resulting in poor sterilization, and the bellows contraction state in the gas phase at the time of valve closing for a long time even during normal liquid feeding operation. In such a case, there is a concern that the quality of the handling liquid may be deteriorated or the hygiene may be deteriorated due to deterioration or decay of the liquid remaining in the groove. Furthermore, in the conventional cylindrical bellows made of synthetic resin, the width of the valley between the annular irregularities cannot be set wide from the point of die cutting at the time of molding, and the expansion / contraction amount of the annular irregularity unit is accordingly reduced. The length of the bellows corresponding to the required stroke becomes longer, requiring a large space for the arrangement of the bellows, making it difficult to make it compact, and the vertical dimension of the valve case is usually much larger than the pipe diameter. was there.

  In view of the circumstances described above, the present invention is a bellows valve particularly suitable for a sanitary specification transportation pipe, and does not cause a liquid pool in the contracted state of the bellows. It is possible to reliably prevent quality deterioration and poor hygiene due to residual liquid in the liquid reservoir during liquid operation, while providing excellent durability even with a synthetic resin bellows, and providing a valve case that is easy to make compact. The purpose is that.

If the means for achieving the above object is shown with reference numerals in the drawings, the invention of claim 1 has a valve portion that opens and closes by raising and lowering the valve operating shaft 2 along the vertical direction. A bellows valve in which a shaft passing portion 11 of the valve operating shaft 2 is sealed by a bellows 3 that expands and contracts vertically as the valve is opened and closed. The bellows 3 is made of a synthetic resin and has a substantially conical shape with a small diameter end. 3a side is fitted to the outer periphery of the valve operating shaft 2 and the large diameter end 3b side is fitted to the valve case 1 side. Each annular outer peripheral surface 30a that is formed in a zigzag shape by bending and faces upwardly forms an inclined surface that is inclined downward , and on the back side of the bellows 3, the annular uneven portion 30 is formed from the back side in the contracted state of the bellows 3. Steps 4a, 4c, 4d to be supported Disposed substantially conical tubular retainer 4A~4C was Introduction retainer 4A~4C are assumed to become configured to sandwiched the small diameter end 3a of the bellows 3 between the valve operating shaft 2.

According to a second aspect of the invention, the bellows valve of the claim 1, retainer 4A is a front portion side ring member 41 clamped the small diameter end 3a of the bellows 3 is held in the valve operating shaft 2 side, the valve casing A base-side ring material 42 that is held on one side and engages the tip-side ring material 41 so as to be movable up and down, and the base-side ring material 42 supports the annular concavo-convex portion 30 of the contracted bellows 3. A portion 4 a is formed, and a stepped portion 4 b is formed on the outer periphery of the front-side ring member 41 to support the annular uneven portion 30 of the expanded bellows 3 from the back side.

According to a third aspect of the present invention, in the bellows valve of the first or second aspect , the valve seat of the valve portion is formed in an annular shape with a hard synthetic resin material, and the valve body portions 2a, 5b corresponding to the annular valve seats 5a, 5b, 2b is configured to be in close contact with the annular valve seats 5a and 5b without using an elastic seal ring.

The invention of claim 4 is characterized in that, in the bellows valve of any one of claims 1 to 3 , the annular uneven portion 30 of the bellows 3 is thinned from the small diameter end 3a side to the large diameter end 3b side.

According to a fifth aspect of the present invention, in the bellows valve according to any one of the first to fourth aspects, an upper and lower two-stage annular valve is provided in the liquid passage 14 that vertically connects the upper flow path 12 and the lower flow path 13 in the valve case 1. An annular valve seat member 5 having seats 5a and 5b is fitted, and the valve operating shaft 2 includes a first valve shaft 21 that passes through the liquid passage 14 and vertically through the valve case 1, and the first valve shaft. A valve body portion corresponding to one of the annular valve seats (the lower annular valve seat 5b) is formed on the first valve shaft 21. 2b is provided, and the second valve shaft 22 is provided with a valve body portion 2a corresponding to the other of the annular valve seats (the upper annular valve seat 5a). Both valve bodies of the first and second valve shafts 21 and 22 are provided. The parts 2a and 2b are configured to be in close contact with each other in the valve open state and to be separated from each other in the valve closed state. It is assumed that a drain flow path 23 communicating with a and 2b and having a lower end opened to the outside is formed.

According to a sixth aspect of the present invention, in the bellows valve of the fifth aspect , an annular gap 24a is formed between the first valve shaft 21 and the second valve shaft 22, and a cleaning liquid supply port 25 is provided at one end of the annular gap 24a. And the other end side communicates between both valve body portions 2a and 2b, and enters the drain passage 23 from the cleaning liquid supply port 25 through the annular gap 24a and between both valve body portions 2a and 2b in the closed state. It is assumed that a cleaning liquid flow path is formed.

  Next, effects of the present invention will be described with reference numerals in the drawings. First, according to the bellows valve according to the first aspect of the present invention, the annular uneven portion 30 in the contracted state of the bellows 3 made of synthetic resin that seals the shaft-passing portion 11 of the valve operating shaft 2 in the valve case 1 is zigzag in longitudinal section. Since each of the annular outer peripheral surfaces 30a facing upward forms an inclined surface that is inclined downward, no liquid pool is generated in the groove portion 32 of the contracted bellows 3. Therefore, when this bellows valve is applied to a transportation pipe of a sanitary plant that handles liquid foods, beverages, chemicals, and the like, there is no concern that condensed water accumulates in the groove portion 32 of the bellows 3 during steam sterilization, resulting in poor sterilization. Even when the bellows 3 is contracted for a long time in the gas phase at the time of valve closing during normal liquid feeding operation, no liquid remains in the groove 32. There is no concern of causing Further, the bellows 3 of this bellows valve has a substantially conical shape as a whole and can be easily punched even if the width of the valley uneven portion 30 is wide in the molding process. Therefore, the length of the bellows corresponding to the required stroke of the valve operating shaft 2 can be shortened, so that the vertical dimension of the valve case 1 can be set to be the same as the pipe diameter.

Moreover , the bellows 3 in the contracted state has its annular concavo-convex portion 30 supported from the back side by the step portions 4a of the retainers 4A to 4C, so that the longitudinal cross-sectional zigzag shape of the annular concavo-convex portion 32 is stably maintained. Since each annular outer peripheral surface 30a facing the upper side is surely in a downwardly inclined state and the retainers 4A to 4C sandwich the small diameter end 3a side of the bellows 3 with the valve operating shaft 2, the A fixing member such as an elastic ring that is externally fitted to fix the small diameter end 3a side of the bellows 3 to the valve operating shaft 2 is not necessary, and a gap due to such external fitting of the fixing member is not generated. In addition, poor sterilization of the gap and alteration or decay of the residual liquid can be avoided.

According to the invention of claim 2 , the extended bellows 3 is supported from the back side by the step portion (inclined step portion 4 b) of the tip side ring member 41 of the retainer 4 A, and the hydraulic pressure applied to the bellows 3 is the tip portion. Since it is received by the side ring material 41, deformation and breakage of the bellows due to hydraulic pressure are prevented, and the bellows 3 has a long life because the load accompanying the expansion and contraction operation is reduced.

According to the invention of claim 3 , since the valve body portions 2a and 2b are configured to abut on the annular valve seats 5a and 5b without using the elastic seal ring, the elastic seal ring and the annular groove necessary for the fitting thereof are provided. Sterilization defects and deterioration and decay of the residual liquid due to the gap between the annular valve seats 5a and 5b are made of synthetic resin, and sufficient sealing performance can be secured. Since there is no need to provide an annular groove for fitting, the valve body portion can be easily processed and assembled.

According to the invention of claim 4 , since the annular concavo-convex portion 30 of the bellows 3 is thinned from the small diameter end 3a side to the large diameter end 3b side, the amount of expansion and contraction is equalized regardless of the difference in diameter depending on the axial position. Therefore, since the degree of bending of each annular convex portion 31 at the time of contraction becomes uniform, it is possible to reliably prevent the liquid pool in the groove portion 32 from being generated.

According to the invention of claim 5 , as a double seal valve type bellows valve, the liquid is accumulated in the groove portion 32 in the contracted state of each bellows 3 that seals the upper and lower shaft passing portions 11 of the valve operating shaft 2 in the valve case 1. In order to prevent bacterial growth and liquid alteration due to the liquid pool, and even if seal breakage occurs on one side of the double seal, the upper and lower flow paths 12 are maintained to maintain the sealed state on the other side. , 13 can be avoided, and leakage due to seal breakage is discharged through the drain passage 23, so that seal breakage can be easily detected from the outside.

According to the invention of claim 6, as the double seal valve type bellows valve, the cleaning liquid flow path is used between the upper and lower annular valve seats 5a and 5b and the inside of both valve body portions 2a and 2b while the valve is closed. What can be cleaned is provided.

It is a longitudinal cross-sectional view of the whole bellows valve of 1st embodiment which concerns on this invention, a right half part shows a valve closing state, and a left half part shows a valve opening state. It is a longitudinal cross-sectional view of the valve case part of the bellows valve, and the right half shows a valve closed state and the left half shows a valve open state. It is a top view of the retainer used for the bellows valve. It is a figure which shows the arrow cross section of the retainer in the XX line of FIG. 3 in the decomposition | disassembly state of a front side ring material and a base side ring material. It is a half vertical side view in the no-load state of the bellows used for the bellows valve. It is a longitudinal cross-sectional view of the lower side axis | shaft through which the bellows was mounted | worn. It is a longitudinal cross-sectional view of the valve case part of the bellows valve of 2nd embodiment of this invention, A right half part shows a valve closing state and a left half part shows a valve opening state. It is a semi-vertical side view of the upper side retainer used for the bellows valve of the second embodiment. It is a half vertical side view of the lower side retainer used for the bellows valve of the second embodiment.

  Hereinafter, embodiments in which the present invention is applied to a double seal valve type bellows valve will be described in detail with reference to the drawings.

  As shown in FIG. 1, the bellows valve V1 of the first embodiment has a yoke on a valve case 1 having an upper flow path 12 and a lower flow path 13 constituted by upper and lower flow path constituting members 1a and 1b. A vertical cylindrical air cylinder 6 incorporating a spring mechanism is placed via 15.

  The valve case 1 includes a circular liquid passage 14 that communicates vertically between the upper and lower flow paths 12 and 13 and upper and lower openings 10a and 10b that are concentrically opposed to each other. A ring-shaped valve seat member 5 made of a synthetic resin provided with the annular valve seats 5a and 5b is fitted, and a thick ring-shaped bottom plate portion 7a of the yoke 7 is fitted into the upper opening 10a, and A thick ring-shaped end plate 15 is fitted in the side opening 10b. In the valve case 1, a valve operating shaft 2 extending in the vertical direction is disposed through the liquid passage 14 through the bottom plate portion 7a and the end plate 15, and the valve operating shaft 2 in the upper and lower openings 10a and 10b. Each of the shaft passing portions 11 is sealed with a substantially conical bellows 3 made of synthetic resin. Further, a substantially conical cylindrical retainer 4A for supporting the bellows 3 from the inside is disposed inside the bellows 3. The air cylinder 6, the yoke 7, the upper and lower flow path components 1 a and 1 b, and the end plate 15 are integrally connected by rotating and tightening the overlapping flange-like connection portions around each other with a clamp band 16. .

  As shown in detail in FIG. 2, the valve operating shaft 2 includes a first valve shaft 21 that forms a main portion thereof, and a cylindrical second valve that is slidably fitted on the upper side of the first valve shaft 21. The shaft 22 is constituted. A trumpet-shaped valve body portion 2b that opens upward is integrally formed at the intermediate portion of the first valve shaft 21, and the valve body portion 2b is fitted to the annular valve seat 5b on the lower side of the valve seat member 5 from above. It is arranged to do. Further, a trumpet-shaped valve body portion 2 a that opens downward is formed at the lower end of the second valve shaft 22, and the valve body portion 2 a is located above the valve body portion 2 b of the first valve shaft 21 on the valve seat member 5. The upper annular valve seat 5a is arranged so as to be fitted from above. Further, the lower part of the first valve shaft 21 than the valve body part 2b is formed in a cylindrical shape having an open lower end, and is formed in an annular space 20 between both valve body parts 2a and 2b via a through hole 23a on the inner upper end. A drain flow path 23 is formed that communicates.

  As shown in FIG. 1, the first valve shaft 21 is threadedly connected to a piston shaft 61a projecting downward from a piston 61 loaded in the air cylinder 6, and has a cylinder upper chamber 60a. The valve is normally urged in the valve closing direction (downward movement direction) by the accumulated force of the compression coil spring 62 loaded on the side. On the other hand, as shown in FIG. 2, the second valve shaft 22 is divided into a lower cylindrical shaft 221 and an upper cylindrical shaft 222 that are integrally formed with the valve body 2 a, and a female screw portion 22 b at the lower end of the upper cylindrical shaft 222 is formed. The male screw portion 22a at the upper end of the lower cylindrical shaft 221 is screwed. The upper end of the upper cylindrical shaft 222 is in contact with the lower end of a cylindrical subshaft 63 fitted to the piston shaft 61a, and between the flange portion 63a of the subshaft 63 and the piston 61 on the cylinder lower chamber 60b side. The first coil 21 is further urged in the valve closing direction by the urging of the compression coil spring 64 loaded on the first valve shaft 21. A donut disk-shaped disc sheet 8 made of a synthetic resin that is fitted onto the first valve shaft 21 is disposed between the valve body portions 2 a and 2 b of both valve shafts 21 and 22.

  As shown in FIG. 5, the bellows 3 includes a thick annular projecting edge portion 33 folded inward on the small diameter end 3 a side, and a thick ring portion 34 on the large diameter end 3 b side, The annular concavo-convex portion 30 gradually increases in diameter from the small-diameter end 3a side to the large-diameter end 3b side, and has a substantially conical outer shape as a whole. Thus, the annular concavo-convex portion 30 is formed in a zigzag shape by repeated bending with a longitudinal cross-sectional shape, and each annular convex portion 31 has a wide annular wall portion 31a on the small diameter end 3a side and a narrow annular shape on the large diameter end 3b side. It is comprised with the wall part 31b. In addition, the bellows 3 shown in FIG. 5 represents the state of no load as a single item.

  As shown in FIGS. 3 and 4, the retainer 4 </ b> A is a front-side ring in which a plurality of (eight in the figure) leg pieces 41 b are equally arranged in the circumferential direction and project downward from the thick ring portion 41 a. A material 41 and a base-side ring material 42 in which a plurality (eight in the figure) of rising pieces 42b are equally arranged in the circumferential direction and project upward from the thin ring portion 42a. The ring members 41 and 42 are detachably fitted in the axial direction so that the latter rising pieces 42b are fitted between the adjacent leg pieces 41b and 41b. The front-side ring material 41 is formed with a plurality of (three in the figure) inclined step portions 4b whose diameters are sequentially reduced toward the distal end on the outer periphery, thereby forming an overall outer shape substantially conical and thick. An inner circumferential step portion 41c facing forward is provided inside the meat ring portion 41a. Further, the base-side ring material 42 forms a two-stepped portion 4a in which the tip portion of each rising piece 42b steps outward, and in a state where the front-side ring material 41 is deeply fitted, Dimensions are set so that the leading end side of each rising piece 42 b protrudes outward from the front-side ring material 41.

  As shown in FIG. 2, the retainer 4 </ b> A on the upper side inserts the base side ring material 42 into the annular groove 71 on the lower surface side of the bottom plate portion 7 a of the yoke 7, and the thickness in the front side ring material 41. With the annular protrusion 33 of the upper bellows 3 sandwiched between the inner peripheral step portion 41c of the meat ring portion 41a and the upper outer peripheral step portion 22d of the lower cylindrical shaft 221 in the second valve shaft 22, The front-side ring member 41 is stopped on the second valve shaft 22 side by pressing the downward outer circumferential step portion 22e of the upper tube shaft 222 that is screwed into the lower tube shaft 221 against the bottom surface of the thick ring portion 41a. I wear it. Further, the large-diameter end 3b side of the upper bellows 3 includes a peripheral edge of the upper opening 10b in the upper flow path component 1a, and an annular protruding edge 72 protruding from the lower surface side of the bottom plate portion 7a of the yoke 7. The thick ring portion 33 is sandwiched between the two.

  On the other hand, as shown in FIGS. 2 and 6, the retainer 4 </ b> A on the lower side inserts the base side ring material 42 into the annular groove 15 a on the inner surface side of the end plate 15, and thickens the front side ring material 41. In a state where the annular protrusion 32 of the bellows 3 on the lower side is sandwiched between the inner peripheral step portion 41c of the ring portion 41a and the downward outer peripheral surface step portion 21a of the first valve shaft 21, the first valve shaft 21 The front ring member 41 is fastened to the first valve shaft 21 side by pressing the fastening ring 26 screwed into the bottom from the bottom surface of the thick ring portion 41a. Further, the large-diameter end 3 b side of the lower bellows 3 is between the peripheral edge of the lower opening 10 b in the lower flow path component 1 b and the annular protruding edge 15 b protruding from the inner surface side of the end plate 15. Thus, the thick ring portion 34 is sandwiched.

  In addition, between the inner side of the small diameter end 3a of each of the upper and lower bellows 3 and the top end of the front-side ring member 41 of the retainer 4A, and between the outer peripheral upper and lower parts of the valve seat member 5 and the inner peripheral surface of the liquid passage 14 An O-ring 9 is interposed between the two. A gasket ring 17 is arranged on the bottom side of the thick ring portion 34 of each bellows 3. Further, bushes 18 are respectively interposed in the upper and lower shaft passing portions 11 of the valve operating shaft 2.

  An annular gap 24a is formed between the upper side of the first valve shaft 21 and the second valve shaft 22 fitted over the first valve shaft 21, and the upper side of the upper cylindrical shaft 221 of the second valve shaft 22 is laterally provided. A cleaning liquid supply port 25 is provided which is screwed in and communicates with the annular gap 24a. Further, the disk seat 8 is provided with an annular locking portion 8 a provided with a plurality of circumferentially dividing grooves on the center side thereof so as to project upward, and the annular locking portion 8 a is formed on the lower cylindrical shaft 221 of the second valve shaft 22. By loosely fitting in the annular locking groove 22c provided on the inner peripheral side, the lower cylindrical shaft 221 is held so as to be slightly movable up and down, and in a state where the pressing force from the lower side does not act, the position is lowered by its own weight. A gap 24b is formed between the upper surface side of the disc seat 8 at the lowered position and the lower surface side of the valve body 2a of the second valve shaft 22, and this gap 24b is interposed via the dividing groove of the annular locking portion 26a. The first valve shaft 21 and the second valve shaft 22 communicate with an annular gap 24a.

  The air cylinder 6 is provided with a vent 65 communicating with the outside on the cylinder upper chamber 60a side, and a compressed air inlet / outlet 66 is provided in the cylinder lower chamber 60b. The piston 61 is normally in the lower limit position due to the urging of the compression coil spring 62, but by introducing compressed air into the cylinder lower chamber 60b, the upper side of the guide shaft 61b protruding upward from the piston 61 is provided. The locking step portion 61c is displaced to the upper limit position where it comes into contact with the inner surface of the cylinder upper wall 6a. Accordingly, the valve body portions 2a and 2b of the valve shafts 21 and 22 are spaced apart from each other in the annular valve seats 5a and 5b at the lower limit position of the piston 61 as shown in the right half of FIGS. The closed valve is pressed. On the other hand, when the piston 61 reaches the lower limit position, as shown in the left half parts of FIGS. As a result, the valve seats are brought into close contact with each other via the disk seat 8.

  Then, as the valve operating shaft 2 moves downward when the valve is closed, as shown in the right half of FIG. 2, the upper bellows 3 expands and the lower bellows 3 contracts. On the other hand, with the upward movement of the valve operating shaft 2 when the valve is opened, as shown in the left half of FIG. 2, the upper bellows 3 contracts and the lower bellows 3 expands. In the contracted state of each bellows 3, the second and third steps of the annular protrusion 31 from the small diameter end 3 a side of the annular uneven portion 30 are supported from the back side by the steps 4 a of the base side ring member 42 of the retainer 4 A. In addition, the fourth-stage annular convex portion 31 is supported from the back side at the top end of the bottom plate portion 7a of the yoke 7 or the annular projecting edge portions 72, 15b of the end plate 15. Further, in the extended state of each bellows 3, 1 to 3 from the small-diameter end 3 a side by the respective inclined step portions 4 b of the tip-side ring material 41 moved to the valve seat member 5 side integrally with the valve operating shaft 2 of the retainer 4 A. A stepped annular convex portion 31 is supported from the back side.

  Here, in the contracted state, the upper and lower bellows 3 are set such that each annular outer peripheral surface 30a facing the upper side of the annular concavo-convex portion 30 forms an inclined surface that is inclined downward. That is, in the contracted state of the lower bellows 3, as shown in the right half part of FIG. 2 and the enlarged view of FIG. 6, the surface direction f1 is gently inclined to the outside by an angle θ with respect to the horizontal direction f0. Yes. On the other hand, each annular outer peripheral surface 30 b facing downward is steeply inclined obliquely upward as an outer surface of the narrow annular wall portion 31 b of each annular convex portion 31. On the other hand, in the upper bellows 3, the vertical relationship is reversed even in the same contracted state as the lower side. Therefore, as shown in the left half of FIG. 2, each annular outer peripheral surface 30 a facing upward is the width of each annular convex portion 31. The outer surface of the narrow annular wall 31b is steeply inclined obliquely downward toward the outside.

  The bellows 3 has a substantially conical annular concavo-convex portion 30 having the same thickness from the small diameter end 3a side to the large diameter end 3b side. The degree of bending of each annular protrusion 31 at that time tends to be non-uniform. Therefore, as shown in FIG. 5, the thickness of zones Z1 to Z5 obtained by dividing the small-diameter end 3a side to the large-diameter end 3b side by the substantially annular convex portion 31 unit is adjusted to Z1> Z2> Z3> Z4> Z5. In addition, for each of the zones Z2 to Z5, the thickness of the small-diameter end 3a side half h1 is made larger than the thickness of the large-diameter end 3b side half h2, thereby equalizing the amount of expansion and contraction. The bending degree of the annular convex portion 31 is set to be uniform.

  The synthetic resin material constituting such a bellows 3 is not particularly limited as long as it is a thermoplastic resin having good chemical resistance and a certain degree of flexibility, but preferred examples include, for example, ethylene tetrafluoride and perfluoro Terpolymers of alkyl vinyl ether and propylene hexafluoride (trade name: Teflon EPE), Copolymer resins of tetrafluoroethylene and hexafluoropropylene (trade name: Teflon FEP), ethylene tetrafluoride and ethylene (Product name: Teflon ETFE, Tefzel) Polyvinylidene fluoride resin (Product name: Teflon PVDF, Kainer), Copolymer of trifluoromonochloroethylene and ethylene (Product name: Teflon ECTFE), Monofluoroethylene Thermoplastic fluororesins such as resin (trade name: Teflon PVF) can be used. The disk sheet 8 is also made of the same synthetic resin material as the bellows 3.

  On the other hand, the synthetic resin material constituting the valve seat member 5 is not particularly limited as long as it is a high-strength resin having good heat resistance, but suitable examples include polyether ether ketone, polyether sulfone, and polysulfone. Each member used for the wetted parts such as the valve case 1, the first valve shaft 21 of the valve operating shaft 2, the lower cylindrical shaft 221 of the second valve shaft 22, etc. is a metal having excellent corrosion resistance such as stainless steel. Material is recommended.

  In the bellows valve V1 configured as described above, when the upper and lower bellows 3 are both in the contracted state, the annular outer peripheral surface 30a that faces the upper portion of the annular uneven portion 30 forms an inclined surface that is inclined downward. A liquid pool does not occur in the groove portion 32 of this. Therefore, when this bellows valve V1 is applied to a transportation pipe of a sanitary plant that handles liquid foods, beverages, chemicals, etc., there is no concern that condensed water accumulates in the groove 32 of the bellows 3 during steam sterilization, resulting in poor sterilization. Even when the bellows 3 is contracted for a long time in the gas phase at the time of valve closing during normal liquid feeding operation, no liquid remains in the groove 32. There is no concern of causing In addition, the valve case 1 has a small arrangement space for the substantially conical bellows 3, so that the vertical dimension is slightly larger than the sum of the diameters of the upper and lower flow passages 12 and 13 as shown in the figure, and is configured compactly as a whole. Therefore, it is easy to assemble to the piping part and easy to handle.

  Furthermore, in the first embodiment, the annular concavo-convex portion 30 of the contracted bellows 3 is supported from the back side by the step portion 4a of the retainer 4A, so that the longitudinal cross-sectional zigzag shape of the annular concavo-convex portion 32 is stably maintained. As a result, each annular outer peripheral surface 30a facing upward is surely inclined downward toward the outside, and the occurrence of a liquid pool in the groove 32 can be completely prevented. Moreover, even in the extended state of the bellows 3, the annular concavo-convex portion 32 is supported from the back side by the inclined step portion 4 b of the front-side ring material 41 of the retainer 4 A, and the hydraulic pressure is received by the front-side ring material 41. It is done. Therefore, the bellows can be prevented from being deformed or damaged by the hydraulic pressure, and the load accompanying the expansion and contraction operation is reduced, so that the lifetime becomes longer.

  On the other hand, since the retainer 4A clamps the small diameter end 3a side of the bellows 3 between the retainer 4A and the valve operating shaft 2, an elastic ring that is externally fitted to fix the small diameter end 3a side of the bellows 3 to the valve operating shaft 2 is provided. Such a fastening member is not necessary, and a gap due to the external fitting of such a fastening member does not occur, so that sterilization failure of the gap and alteration or decay of the residual liquid can be avoided. In addition, since the valve body portions 2a and 2b are configured to contact the annular valve seats 5a and 5b without using the elastic seal ring, the valve body portions 2a and 2b are caused by a gap between the elastic seal ring and the annular groove necessary for the fitting. It is possible to avoid poor sterilization and alteration or decay of the residual liquid. Further, since the annular valve seats 5a and 5b are made of synthetic resin, sufficient sealing performance can be ensured. In addition, since it is not necessary to provide the annular groove for fitting in the valve body portions 2a and 2b, Assembly is easy.

  In the double seal valve type bellows valve V1 of the first embodiment, the upper and lower flow paths 12, 13 are maintained in order to maintain the sealed state on the other side even if seal failure occurs on one side of the double seal. In addition to avoiding the liquid mixture, the leak due to the seal breakage is discharged through the drain flow path 23, so that the seal breakage can be easily detected from the outside. In addition, by introducing the cleaning liquid from the cleaning liquid supply port 25 using the interval between the valve closing, the cleaning liquid passes through the annular gap 24a between the first valve shaft 21 and the second valve shaft 22, and the disc seat 8 and the valve It enters the annular space 20 between the valve body parts 2a, 2b being closed and the valve seat member 5 through the gap 24b with the lower surface side of the body part 2a, and flows out from the through hole 23a to the drain passage 23. Therefore, there is also an advantage that the space between the upper and lower annular valve seats 5a and 5b and the inside of both valve body portions 2a and 2b can be cleaned.

  The bellows valve V2 of the second embodiment shown in FIG. 7 is the one in which the present invention is applied to a double seal valve as in the first embodiment described above. In this second embodiment, since each part except the retainer of the bellows valve V2 has substantially the same configuration as the first embodiment, the same reference numerals are given to the common parts with the first embodiment, and the details thereof will be described. Omitted.

  In the bellows valve V2, as in the first embodiment, the valve operating shaft 2 is composed of a first valve shaft 21 having a valve body portion 2b and a cylindrical second valve shaft 22 fitted on the upper side thereof. The second valve shaft 22 is divided into a lower cylindrical shaft 221 and an upper cylindrical shaft 222 having a valve body 2a at the lower end, and the upper cylindrical shaft 222 supports the upper bellows 3 from the rear side. 4B is also used. Further, the liner 4C for supporting the lower bellows 3 from the back side is constituted by a single member.

  As shown in detail in FIG. 8, the upper cylindrical shaft 222 of the second valve shaft 22 is a substantially conical cylindrical liner 4 </ b> B whose upper side forms a round shaft portion 222 a and whose lower side has a large base outer diameter. The liner 4B has a plurality of (three in the figure) narrow annular step portions 4c that are successively enlarged in diameter from the distal end (lower end) side, and a wide annular step portion 4d that is greatly enlarged on the most proximal side. And an inner peripheral step 43 is provided on the inner peripheral tip side. On the other hand, the lower-side liner 4C has a substantially conical cylindrical shape as a whole, but, like the liner 4B of the upper cylindrical shaft 222, the outer peripheral surface has a plurality of stages (three stages in the figure) that are sequentially expanded from the tip side. The narrow annular step portion 4c and the wide annular step portion 4d having a large diameter on the most proximal side are formed, and an inner peripheral step portion 43 is provided on the inner peripheral tip side. Note that the narrow annular step 4c and the wide annular step 4d of both the liners 4B and 4C both form a downwardly inclined annular inclined surface toward the outer peripheral side.

  As shown in FIG. 7, the upper retainer 4 </ b> B integrated with the upper cylindrical shaft 222 includes the downward inner peripheral step 43 and the upward outer peripheral step 22 d of the lower cylindrical shaft 221 in the second valve shaft 22. With the annular projecting edge 33 of the upper bellows 3 sandwiched therebetween, the cylindrical shafts 221 and 222 are screwed together to fix the small diameter end 3a side of the bellows 3. The lower retainer 4 </ b> C sandwiches the annular protruding edge 32 of the lower bellows 3 between the upward inner peripheral stepped portion 43 and the lower outer peripheral stepped portion 21 a of the first valve shaft 21. In this state, the fastening ring 26 screwed into the first valve shaft 21 from below is pressed against the bottom surface of the thick ring portion 41a, so that the small diameter end 3a side of the bellows 3 is fixed at the same time. It is fixed to the first valve shaft 21. The large-diameter end 3b side of the upper and lower bellows 3 is fastened to the valve case 1 side by sandwiching the thick ring portion 34 as in the first embodiment.

  Each bellows 3 in the second embodiment is substantially the same as that used in the first embodiment. However, as shown in FIG. 7, in the contracted state, the annular concavo-convex portion 30 has a degree of expansion and contraction close to no load. On the other hand, in a stretched state, the zigzag shape of the longitudinal section of the annular concavo-convex portion 30 is stretched until it is almost linear. Thus, as shown in the figure, the retainers 4B and 4C have the annular stepped portions 4c and 4d that support the annular convex portions 31 of the annular concave and convex portions 30 from the back side in the contracted state of the bellows 3, and the retainers 4B and 4C in the expanded state. The narrow annular step 4c and the wide annular step 4d at the front end are in contact with the back surface of the extended annular concavo-convex portion 30.

  Also in the bellows valve V2 of the second embodiment, when each bellows 3 is in a contracted state, each annular outer peripheral surface 30a facing above the annular uneven portion 30 forms an inclined surface that is inclined downward. A liquid pool is not generated in the groove 32 of the uneven portion 30. Therefore, when it is applied to the liquid transportation pipes of various sanitary plants, there is no concern that condensed water accumulates in the groove 32 during the steam sterilization, resulting in poor sterilization. In addition, even when the bellows 3 is contracted in a gas phase when the valve is closed during normal liquid feeding operation, the liquid does not remain in the groove 32, so that the residual liquid may be altered or spoiled. There is no.

  In the second embodiment as well, the annular concavo-convex portion 30 of the contracted bellows 3 is supported from the back side by the annular step portions 4c, 4d of the retainers 4B, 4C. Is maintained stably, and each annular outer peripheral surface 30a facing upward is surely inclined downward toward the outside, and the above-described liquid pool in the groove 32 can be completely prevented. Further, the bellows 3 is supported by the annular stepped portions 4c and 4d of the retainers 4B and 4C at a plurality of locations, so that deformation and breakage due to hydraulic pressure are prevented. At the same time, the load associated with the expansion and contraction operation is reduced, thereby extending the service life.

  In the second embodiment, the upper retainer 4B is integrally formed with the upper cylindrical shaft 222 of the second valve shaft 22 in the valve operating shaft 2, and the lower retainer 4C is constituted by a single member. Therefore, there is an advantage that the number of parts is smaller than that in the case of the first embodiment, and assembling and manufacturing are easier. However, in the configuration of the first embodiment, since the expansion and contraction amount of the bellows 3 accompanying opening and closing of the valve is small, the bellows 3 has an advantage that fatigue deterioration is reduced and the life is extended.

Although the bellows valve applied to the double seal valve is illustrated in the first and second embodiments, the bellows valve of the present invention can also be applied to a single seal valve. In addition, when there is only one shaft-passing portion of the valve operating shaft in the valve case as in a normal single seal valve, there is naturally one bellows that seals the shaft-passing portion. On the other hand, the retainer for supporting the annular uneven portions of the bellows contracted state from the rear side, Ru can employ various structures other than those illustrated in the first and second embodiments. Also, the first and second embodiment is a configuration in which the valve body is fitted to the valve seat from above, it may be configured to valve body portion conversely is fitted into the valve seat from below. Furthermore, although the air cylinder system is employed as the valve operating mechanism in the embodiment, various other valve operating mechanisms such as a hydraulic cylinder system and an electromagnetic drive system can be employed in the present invention. In addition, the detailed configuration of the bellows valve of the present invention can be variously modified in addition to the embodiment.

DESCRIPTION OF SYMBOLS 1 Valve case 11 Axis passing part 12 Upper flow path 13 Lower flow path 14 Liquid path 2 Valve operation shaft 2a, 2b Valve body part 21 First valve shaft 22 Second valve shaft 23 Drain flow path 24a Annular gap 25 Cleaning liquid supply port 3 Bellows 3a Small-diameter end 3b Large-diameter end 30 Annular uneven part 30a Annular outer peripheral surface facing upward 4A to 4C Retainers 4a, 4b Step part 4c, 4d Annular step part 41 Front side ring material 42 Base side ring material 5 Valve seat member 5a , 5b Annular valve seat V1, V2 Bellows valve

Claims (6)

A bellows valve having a valve portion that opens and closes by raising and lowering a valve operating shaft along a vertical direction, and a shaft passage portion of the valve operating shaft in a valve case is sealed by a bellows that expands and contracts vertically as the valve opens and closes. ,
The bellows is made of a synthetic resin and has a substantially conical shape, and is fitted on the outer periphery of the valve operating shaft on the small diameter end side and on the valve case side on the large diameter end side,
The annular concavo-convex portion in the contracted state of the bellows is formed in a zigzag shape by repeated bending of a vertical cross-sectional shape, and each annular outer peripheral surface facing above forms an inclined surface with a downward slope outward ,
On the back side of the bellows, a substantially conical cylindrical retainer provided with a stepped portion that supports the annular uneven portion from the back side in the contracted state of the bellows,
A bellows valve configured such that the retainer sandwiches the small diameter end side of the bellows between the valve operating shaft and the retainer . The retainer is held on the valve operating shaft side and clamps the small diameter end side of the bellows, and a base portion that is held on the valve case side and fits the tip side ring material so that it can move up and down The ring-shaped uneven portion of the bellows in the contracted state is formed on the base-side ring material, and the annular uneven portion of the bellows in the stretched state is formed on the outer periphery of the front-side ring material. The bellows valve according to claim 1 , wherein a stepped portion that is supported from the back side is formed. The valve seat of the valve portion is formed in an annular shape with a hard synthetic resin material, and the valve body portion corresponding to the annular valve seat is configured to be in close contact with the annular valve seat without an elastic seal ring. Item 3. A bellows valve according to item 1 or 2 . The bellows valve according to any one of claims 1 to 3 , wherein the annular uneven portion of the bellows is thinned from the small diameter end side to the large diameter end side. An annular valve seat member having two upper and lower annular valve seats is fitted in a liquid passage vertically connecting the upper flow path and the lower flow path in the valve case,
The valve operating shaft includes a first valve shaft that vertically passes through the valve case through the liquid passage, and a cylindrical second valve shaft that is slidably fitted to the first valve shaft. The first valve shaft is provided with a valve body portion corresponding to one of the annular valve seats, and the second valve shaft is provided with a valve body portion corresponding to the other of the annular valve seats. Both valve body parts of the valve shaft are configured to be in close contact with each other when the valve is open and spaced apart in the closed state. The upper end of the first valve shaft is communicated between the valve body parts. The bellows valve according to any one of claims 1 to 4 , wherein a drain flow path having a lower end opened to the outside is formed. An annular gap is formed between the first valve shaft and the second valve shaft, a cleaning liquid supply port is provided on one end side of the annular gap, and the other end side communicates between the two valve body portions, The bellows valve according to claim 5 , wherein a cleaning liquid flow path is formed from the cleaning liquid supply port to the drain flow path through the annular gap and both valve body portions in a closed state.

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