JP4533500B2 - Diaphragm valve - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a diaphragm valve used for opening and closing a flow path of a liquid pipe in various liquid pipes in the food industry and the pharmaceutical industry.
[0002]
[Prior art]
FIG. 6 shows a conventional diaphragm valve. This diaphragm valve has a peripheral edge on the surface side of a diaphragm 4 arranged so as to face a valve seat 3 provided in the valve body 1 on an annular diaphragm mounting seat 2 provided on the side wall 1 a of the valve body 1. By fixing and driving the operating shaft of the valve operating portion 5 connected to the central portion on the back side of the diaphragm 4 to advance and retreat in the axial direction, the surface side of the diaphragm 4 is separated from the valve seat 3 to open and close the flow path. It has become. This valve operation part 5 consists of an air cylinder, The piston rod becomes an operating shaft. This air cylinder is attached to the valve body 1 via a bracket 8.
[0003]
[Problems to be solved by the invention]
In the conventional diaphragm valve, as shown in FIG. 6, the peripheral edge of the diaphragm 4 is sandwiched between the diaphragm mounting seat 2 and the bracket mounting flange 6 of the valve operating section 5. Since the peripheral edge of the diaphragm 4 is fixed to the mounting seat 2 by tightening with four bolts 7 penetrating the seat 2, if the tightening force of the bolt 7 is weak, the peripheral edge of the diaphragm with respect to the mounting seat 2 If the pressing force of the bolt 7 is insufficient, liquid leakage occurs, and the tightening force of the bolt 7 is too strong, the pressing force of the diaphragm peripheral portion locally increases at the peripheral portion of each bolt 7, and the adjacent bolt 7 , 7, a gap is formed between the diaphragm 4 and the mounting seat 2, and liquid leakage occurs, making it difficult to tighten and tighten the bolt 7, and there are individual differences in tightening work. To accurately fix the peripheral part to the diaphragm mounting seat 2 is very difficult.
[0004]
Further, as shown in FIG. 7, the diaphragm 4 has excellent chemical resistance such as Teflon (polytetrafluoroethylene, a registered trademark of DuPont) on the surface side, that is, the wetted side, and also has good water resistance and surface lubricity. A front side film 4a made of a fluororesin having a thickness of about 1 mm and a rubber back side film 4b that is polymerized on the back side and backs up the front side film 4a. However, the back side membrane 4b made of rubber hardly shows thermal expansion or contraction due to temperature change, but the front side membrane 4a made of fluororesin such as Teflon expands up to a certain temperature, but contracts when it exceeds that temperature. Due to its nature, the peripheral portion of the front membrane 4a attached to the mounting seat 2 of the valve body 1 has a sufficient shrinkage margin W.
[0005]
That is, as shown in FIG. 8, an annular protrusion 9 is formed along the peripheral edge of the front side film 4 a in order to improve the sealing effect on the diaphragm mounting seat 2 and the valve seat 3. A straight ridge portion 10 for a valve seat that connects the annular ridge portion 9 in the diameter direction is provided, and an annular shape that substantially seals the diaphragm 4 and the diaphragm mounting seat 2. The space between the protrusion 9 and the inner edge of the diaphragm mounting seat 2 is the shrinkage allowance W. As can be seen from FIG. 7, when the shrinkage margin W is long, the gap S formed between the surface of the front membrane 4a, that is, the liquid contact surface, and the seat surface of the diaphragm mounting seat 2 becomes deeper. Since the liquid in the channel easily enters and accumulates in the flow path and is difficult to clean, it is extremely unsanitary when the liquid is food such as milk. In FIG. 8, reference numeral 4 c denotes bolt insertion holes provided at the four corners of the diaphragm 4.
[0006]
In view of the above-mentioned problems, the present invention attaches the peripheral edge of the diaphragm to the diaphragm mounting seat accurately over the entire periphery, and securely seals between the peripheral edge of the diaphragm and the diaphragm mounting seat. An object of the present invention is to provide a diaphragm valve capable of preventing liquid leakage. Another object of the present invention is to reduce the shrinkage margin provided on the front membrane of the diaphragm as much as possible, thereby reducing the gap formed between the liquid contact surface of the front membrane and the seat surface of the diaphragm mounting seat. Then, it is providing the diaphragm valve which made it easy to wash | clean the clearance gap.
[0007]
[Means for Solving the Problems]
According to the first aspect of the invention, the peripheral edge of the surface side of the diaphragm 14 disposed opposite to the valve seat 13 in the valve body 11 is fixed to an annular diaphragm mounting seat 12 provided in a required portion of the valve body 11. The operating shafts 35 and 45 of the valve operating unit 15 connected to the central portion on the back side of the diaphragm 14 are driven to advance and retract in the axial direction, whereby the surface side of the diaphragm 14 is separated from and connected to the valve seat 13 to open and close the flow path. In the diaphragm valve, the diaphragm 14 includes a front side film 14a made of fluororesin and a rubber back side film 14b superposed on the back side of the fluororesin, and the front side film 14a has an annular convex portion at the peripheral edge of the surface thereof. 25 and an annular protrusion 19 on the inner peripheral side thereof, the diaphragm mounting seat 12 has an annular convex portion 28 on the inner peripheral side, and a bracket on the valve operating portion side on the outer peripheral side of the mounting seat 12. For mounting Lunge 16 and the bolt 17 an annular seat 27 for coupling provided so as to protrude a predetermined height from the seating surface of the mounting seat 12, the diaphragm 14 in the recessed step portion 29 formed on the outer periphery of the annular projection 28 of the mounting seat 12 Engaging the annular convex step portion 25 of the front side film 14a, and bringing the annular protrusion 19 on the inner peripheral side of the annular convex step portion 25 into contact with the annular convex portion 28 of the diaphragm mounting seat 12, bolt and said annular seat 27 and the flange 16 pressed against the said attachment seat 12 to press the peripheral portion corresponding to the annular protruding portion 19 of the diaphragm 14 by the diaphragm pressing portion 30 integral with the flange 16 It is characterized by 17 couplings.
[0008]
[0009]
[0010]
Claim 2 is the diaphragm valve according to claim 1, pressing surface 30a of the diaphragm presser 30 is in a position that protrudes a predetermined length from the contact surface of the annular seat 27 abuts on the bracket mounting flange 16 It is characterized by that.
[0011]
A third aspect of the present invention is the diaphragm valve according to the first or second aspect , wherein the diaphragm 14 is formed in a circular shape.
[0012]
According to a fourth aspect of the present invention, in the diaphragm valve according to any one of the first to third aspects, the valve operating portion 15 includes a cylinder coupled to a bracket 18 attached to the valve body 11 side. Form an actuating shaft.
[0013]
According to a fifth aspect of the present invention, in the diaphragm valve according to any one of the first to third aspects, the valve operating portion 45 includes a screw shaft 38 screwed into the bracket 18 attached to the valve body 11 side, and the screw shaft 38. It comprises a handle 39 that rotates, and the screw shaft 38 forms an operating shaft.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a half longitudinal sectional front view of a diaphragm valve according to the present invention, and FIG. 2 is a bottom view thereof. In these drawings, reference numeral 11 denotes a tubular valve body, and a weir 23 is formed at the center in the longitudinal direction of the valve body 11 to form a concave curved valve seat 13. Reference numeral 12 denotes a diaphragm mounting seat for mounting the surface side peripheral portion of the diaphragm 14, which is formed on the side wall portion 11a of the valve body 11, and is formed on both sides of the diaphragm mounting seat 12 with a weir 23 interposed therebetween. Valve ports 21a and 22a communicating with the inlet / outlet pipe portions 21 and 22 are opened.
[0015]
The diaphragm 14 includes a front film 14a made of a fluororesin and a rubber back film 14b superposed on the back side of the front film 14a. Both films 14a and 14b are connected to a connecting shaft 24 attached to the center thereof. Are connected by As shown in FIG. 3, the front side film 14a, depending Teflon is a fluorine resin be formed to a thickness of 1mm approximately disc shape, a square cross section of the annular projection step portion 25 is strip set on the periphery of the surface , together with the annular ridge portion 19 is strip set on the inner peripheral side of the annular convex stepped portion 25, the linear projecting portions 20 connecting the annular ridge portion 19 in a diametrical direction are strip set. The back membrane 14b is formed of a synthetic rubber that is resistant to temperature changes, and is formed in a disk shape having a thickness of about 4 mm and a slightly larger diameter than the front membrane 14a. A metal retainer 26 is disposed on the back surface of the back film 14b, and the retainer 26, the back film 14b, and the front film 14a are integrally coupled to each other through the connecting shaft 24 so as not to rotate.
[0016]
As shown in FIGS. 1 and 4, on the outer peripheral side of the diaphragm mounting seat 12, an annular pedestal 27 that is bolted to the bracket mounting flange 16 on the valve operating portion 15 side has a predetermined height from the seating surface of the diaphragm mounting seat 12. It is provided so that it may protrude. An annular convex portion 28 that protrudes upward is provided on the inner peripheral side of the diaphragm mounting seat 12, whereby an annular concave step portion 29 is formed on the outer periphery of the annular convex portion 28. In this case, the seating surface of the diaphragm mounting seat 12 substantially means the upper surface of the annular projection 28.
[0017]
Further, an annular diaphragm pressing portion 30 is formed on the inner peripheral edge of the bracket mounting flange 16 so as to project integrally with the flange 16, and the lower end pressing surface 30a of the diaphragm pressing portion 30 is as shown in FIG. Further, the bracket mounting flange 16 that contacts the annular pedestal 27 is in a position that protrudes downward by a predetermined length α from the contact surface 16 a of the bracket mounting flange 16. Thus, by forming the diaphragm pressing portion 30 in an annular body protruding from the contact surface 16a of the flange 16, the peripheral edge portion of the diaphragm 14 can be effectively compressed. The protrusion length α of the diaphragm pressing portion 30 is such that the annular ridge portion 19 is sufficiently above the annular convex portion 28 in a state in which the peripheral edge portion of the diaphragm 14 having a predetermined thickness is fitted into the diaphragm mounting seat 12 as shown in the figure. The length is set so that the peripheral edge can be pressed and compressed so as to be in close contact with each other. In this setting, the protruding height of the annular protrusion 28 of the diaphragm mounting seat 12, the thickness of the diaphragm 14, and the elasticity thereof are set. Consider power.
[0018]
In addition, an engagement groove 32 is provided at a required portion of the diaphragm pressing portion 30 so as to engage the detent pin 31 protruding from the retainer 26. The detent pin 31 not only prevents the rotation of the diaphragm 14 but also positioning means for properly positioning the linear protrusion 20 provided on the surface of the front side film 14 a on the valve seat 13. But there is. Also, the bracket mounting flange 16 and the annular pedestal 27 on the valve body 11 side are provided with screw holes 16a and 27a for bolt connection at four locations. The diaphragm pressing portion 30 can also be provided so as to be removable from the bracket mounting flange 16.
[0019]
As shown in FIG. 1, the valve operating portion 15 is composed of an air cylinder connected to a bracket 18 having a flange 16 formed at the lower end thereof. The cylinder 15 includes a cylinder body 33, a piston 34, a piston 34, A piston rod 35 that reciprocally moves integrally in the axial direction, and this piston rod 35 forms an operating shaft of the diaphragm valve. The piston rod (operating shaft) the lower end 35 is connected to the retainer 26, closed form by axial reciprocating drive of the piston rod 35, diaphragm 14, in contact with the valve seat 13 as shown by the solid line shown in FIG. 1 Then, as shown in the phantom line in the figure, the form is converted into a valve opening form spaced from the valve seat 13. As shown in FIG. 1, a part of the bracket 18 forms a lower end wall portion 33 a of the cylinder body 33. In FIG. 1, reference numeral 36 denotes a coil spring that normally biases the piston 34 toward the valve closing side.
[0020]
Next, a method for mounting and fixing the diaphragm 14 to the diaphragm mounting seat 12 of the valve body 11 will be described. First, with the bracket 18 removed from the valve body 11, the diaphragm 14 is fitted into the diaphragm mounting seat 12 whose outer periphery is surrounded by the annular pedestal 27, and as shown in FIG. The step portion 25 is engaged with the concave step portion 29 formed on the outer periphery of the annular convex portion 28 on the mounting seat 12 side so that the annular protrusion 19 is brought into contact with the annular convex portion 28 of the mounting seat 12 and is linear. The protruding ridge portion 20 is brought into contact with the valve seat 13. From such state, the flange 16 of the bracket 18 reluctant such was placing on the annular seat 27, the lower end portion of the diaphragm presser 30, inrush engaged engaged in an annular groove 37 formed on the rear side of the back side film 14b, and an annular The bolt 17 is screwed into the screw hole 16a of the flange 16 from the screw hole 27a of the pedestal 27 and tightened, and the flange 16 is bolted to the annular pedestal 27.
[0021]
By fastening the flange 16 to the annular pedestal 27 with the four bolts 17 in this way, the diaphragm pressing portion 30 uniformly compresses the peripheral edge portion corresponding to the annular ridge portion 19 of the diaphragm 14 over the entire circumference, The annular protrusion 19 of the front membrane 14a is pressed against the annular projection 28 of the diaphragm mounting seat 12, thereby completely sealing between the front membrane 14a and the annular projection 28 of the mounting seat 12. At this time, the pressure applied to the peripheral edge portion of the diaphragm 14 by the diaphragm pressing portion 30 is set in advance in consideration of the protruding height of the annular protrusion 28 of the diaphragm mounting seat 12, the thickness of the diaphragm 14, and its elastic force. Therefore, it is only necessary to fasten the bolt 17 and fasten the flange 16 to the annular pedestal 27. Therefore, there is no overtightening or undertightening of the bolt 17, and no matter who tightens the bolt 17, there are individual differences in tightening work. Therefore, the peripheral edge of the diaphragm 14 can be accurately fixed to the diaphragm mounting seat 12 over the entire circumference, and liquid leakage can be reliably prevented.
[0022]
Further, according to the mounting structure of the diaphragm 14, the front side film 14a of the diaphragm 14 has an annular projection step portion 25 which is Article set on its periphery, an annular ridge 19 which is Jo設on the inner peripheral side of this has a diaphragm mounting seat 12 has an annular projection 28 on the inner peripheral side thereof, Kakarihama the annular projection step portion 25 of the front side film 14a to the recessed step portion 29 formed on the outer periphery of the annular projection 28 As a result, the annular protrusion 19 of the front membrane 14a is brought into contact with the annular projection 28 of the diaphragm mounting seat 12, so that the front membrane 4a made of fluororesin such as Teflon is contracted by the high-temperature liquid flowing in the flow path. even, by the annular convex stepped portion 25 of the front side film 14a is restricted to the recessed step portion 29 formed on the outer periphery of the mounting seat 28, so that the contraction of the front side film 14a is restricted. Therefore, as shown in FIG. 4, the annular protrusion 19 of the front membrane 14a can be disposed as close to the inner peripheral edge of the diaphragm attachment seat 12 as possible, thereby the annular projection 19 and the attachment seat of the front membrane 14a. The shrinkage margin w, which is the distance between the 12 inner peripheral edges, can be made as narrow as possible.
[0023]
Since the shrinkage w can be made as narrow as possible in this way, a gap cannot be formed between the surface of the front membrane 14a and the diaphragm mounting seat, and even if a gap is formed, the gap is shallow, so that liquid accumulates. Difficult , easy to clean and extremely hygienic. Further, since the diaphragm 14 is mounted and fixed to the diaphragm mounting seat 12, a bolt hole is provided in the peripheral edge portion of the diaphragm 14 and not bolted as in the prior art, the shape of the diaphragm 14 can be made circular. Can save material.
[0024]
FIG. 5 shows a diaphragm valve having a manual valve operating section 45. The configuration of the valve operating section 45 is the same as that of the diaphragm valve shown in FIGS. The same reference numerals are given and the description is omitted. The valve operating portion 45 includes a screw cylinder portion 18a at the upper end of the bracket 18 attached to the valve body 11 side, a screw shaft 38 screwed into the screw cylinder portion 18a, and a handle for rotating the screw shaft 38. 39, and the screw shaft 38 forms the operating shaft of the diaphragm valve. Therefore, the diaphragm 14 can be moved from the valve seat 13 to the valve closed form by rotating the handle 39 by the hand of the handle 39 to drive the screw shaft 38 to advance and retreat in the axial direction. It is possible to change the form to a separated valve opening form.
[0025]
【The invention's effect】
According to the diaphragm valve of the invention according to claim 1, by fastening the bracket mounting flange to the annular pedestal of the valve body with a bolt, the diaphragm holding portion has a peripheral portion corresponding to the annular ridge portion of the diaphragm. By uniformly compressing the entire circumference, this peripheral edge can be pressed against the diaphragm mounting seat, thereby completely sealing between the front surface peripheral edge of the diaphragm and the diaphragm mounting seat. At this time, the pressure applied to the peripheral edge of the diaphragm by the diaphragm pressing portion is a constant pressure set in advance in consideration of the protruding height of the annular convex portion from the diaphragm mounting seat, the thickness of the diaphragm, and the elastic force thereof. Therefore, it is only necessary to fasten the bolt and fasten the flange to the annular pedestal. Therefore, there is no overtightening or undertightening of the bolt, and there is no individual difference in the tightening work. Therefore, it is possible to reliably prevent liquid leakage.
[0026]
According to the diaphragm valve of the present invention, the diaphragm includes an annular convex stepped portion are conditions set on the periphery thereof, and an annular ridge which is Jo設on the inner peripheral side of this, the diaphragm mounting seat of the has an annular projection on the peripheral side, by Kakarihama the annular convex stepped portion of the diaphragm to the concave stepped portion formed on the outer periphery of the annular projection, an annular annular ridge portion of the diaphragm of the diaphragm mounting seat Since the front side film made of a fluororesin such as Teflon is contracted by the high-temperature liquid flowing in the flow path, the annular convex step portion of the diaphragm is formed on the outer periphery of the mounting seat. By restricting to the concave step, the contraction of the front membrane is limited, so that the annular ridge of the diaphragm can be placed as close as possible to the inner peripheral edge of the diaphragm mounting seat, and thereby the annular ridge of the diaphragm Department and diamond As much as possible narrow margin shrinkage is the distance between the inner peripheral edge of the ram mounting seat. Since the margin of contraction can be made as narrow as possible in this way, a gap cannot be formed between the peripheral edge of the diaphragm and the diaphragm mounting seat, and even if a gap is formed, the gap is shallow, so it is difficult for liquid to accumulate, Easy to clean and extremely hygienic.
[0027]
[0028]
As described in claim 2 , since the pressing surface of the diaphragm pressing portion is located at a position protruding a predetermined length from the contact surface of the bracket mounting flange that contacts the annular pedestal, the peripheral edge of the diaphragm can be effectively compressed. .
[0039]
According to a third aspect of the present invention, since the diaphragm is formed in a circular shape, the material for forming the diaphragm can be reduced, and the material can be saved.
[0030]
As described in claim 4 , when the valve operating portion is composed of a cylinder connected to a bracket attached to the valve body side, the axial movement of the operating shaft can be automatically performed. Further, as described in claim 5 , in the case where the valve operating portion includes a screw shaft screwed into a bracket attached to the valve body side and a handle for rotating the screw shaft, Direction advance and retreat drive can be done easily and easily by manual operation with the handle.
[Brief description of the drawings]
FIG. 1 is a half longitudinal sectional front view of a diaphragm valve according to the present invention.
FIG. 2 is a bottom view of the diaphragm valve shown in FIG.
3A is a front view of a diaphragm, and FIG. 3B is a cross-sectional view taken along line XX in FIG.
4 is a partially enlarged sectional view of the diaphragm valve shown in FIG.
FIG. 5 is a half vertical sectional front view of a diaphragm valve having a manual valve operating section.
FIG. 6 is a partial sectional front view showing a conventional diaphragm valve.
7 is a partially enlarged view of the conventional diaphragm valve shown in FIG.
FIG. 8 is a front view of a conventional diaphragm valve.
[Explanation of symbols]
11 valve body 12 Diaphragm mounting seat 13 valve seat 14 the diaphragm 15 valve operating unit 16 bracket mounting flange 17 bolts 18 the brackets 19 annular projecting portions 20 straight protrusions 25 annular convex stepped portion 27 circular base 28 annular protrusion 29 recess Step part 30 Diaphragm presser part 35 Piston rod (working shaft)
38 Screw shaft (working shaft)
45 Valve operation part

Claims (5)

Valve operation that is fixed to the annular diaphragm mounting seat provided in the required part of the valve body with the peripheral edge on the surface side of the diaphragm arranged facing the valve seat in the valve body, and connected to the central part on the back side of this diaphragm In the diaphragm valve that opens and closes the flow path by moving the operating shaft of the part in the axial direction, the diaphragm is polymerized on the front side membrane made of fluororesin and on the back side It is composed of a rubber back side film to be arranged, and the front side film has an annular convex step part on the peripheral part of the surface thereof and an annular projecting part on the inner peripheral side thereof, and the diaphragm mounting seat on the inner peripheral side an annular protrusion, the outer peripheral side of the mounting seat, an annular seat for coupling the bracket mounting flange and bolts of the valve operating portion to a predetermined height projecting from the mounting seat, the annular projection of said mounting seat Formed on the outer periphery of the part Engaging the annular convex step portion of the front membrane of the diaphragm with the concave step portion, and bringing the annular protrusion on the inner peripheral side of the annular convex step portion into contact with the annular convex portion of the diaphragm mounting seat, diaphragm valve in which the said flange and the annular seat in a state that presses the peripheral edge portion corresponding to the annular protrusion of the diaphragm by the diaphragm presser portion forming the flanges integrally pressed against the mounting seat so that bolted . 2. The diaphragm valve according to claim 1, wherein a pressing surface of the diaphragm pressing portion is located at a position protruding a predetermined length from a contact surface of a bracket mounting flange that contacts the annular pedestal. The diaphragm valve according to claim 1 or 2 , wherein the diaphragm is formed in a circular shape. The diaphragm valve according to any one of claims 1 to 3 , wherein the valve operating portion is composed of a cylinder connected to a bracket attached to the valve body side, and a piston rod of the cylinder forms an operating shaft. Valve control unit includes a screw shaft which is screwed to a bracket attached to the valve body side and a handle for rotating operating the threaded shaft, any one of claims 1 to 3, wherein the screw shaft forms a shaft operation The diaphragm valve as described in 1.

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