JP7637938B2 - Wear Valve - Google Patents

Description

The present invention relates to a wear valve that includes a flow path, a weir provided in the flow path, and a diaphragm valve body having a thin film portion, and in which the thin film portion elastically deforms to cause the diaphragm valve body to move toward and away from the weir, thereby controlling the flow of fluid through the flow path.

In beverage filling devices, wear valves are often used to control the amount of beverage filled into beverage containers. As shown in Patent Document 1, for example, a wear valve is equipped with a flow path, a weir provided in the flow path, and a diaphragm valve body with a thin film portion, and the thin film portion elastically deforms to cause the diaphragm valve body to come into contact with and separate from the weir, thereby controlling the fluid flowing through the flow path.

The wear valve shown in Patent Document 1 is a manually opened and closed type, but beverage filling devices use air-operated wear valves 5, such as those shown in Figures 3, 5, and 7.

The wear valve 5 is composed of a drive unit 2, a body 6, and a diaphragm valve element 4 that is clamped and fixed between the drive unit 2 and the body 6.

The drive unit 2 has a piston 25 and a spring 28 inside. The piston 25 rises or falls in the piston chamber 27 due to the operating air introduced into the drive unit 2 and the elastic force of the spring, and as the piston 25 rises or falls, the center of the diaphragm valve body 4 rises or falls. This causes the diaphragm valve body 4 to separate from or come into contact with the weir 35, opening or closing the wear valve 5.

The body 6 has an input side flow path 31 and an output side flow path 32 that form a flow path from the input port 33 to the output port 34. A weir 35 against which the diaphragm valve body 4 comes into contact and separates is provided on the flow path.

The diaphragm valve body 4 has a two-layer structure with a first layer 4a made of polytetrafluoroethylene (PTFE) on the liquid-contacting surface side and a second layer 4b made of ethylene propylene diene rubber (EPDM) on the opposite side to the liquid-contacting surface side. The diaphragm valve body 4 also has a thin film portion 42, and the outer periphery of the thin film portion 42 is provided with a fixed portion 43 connected to the thin film portion 42. This fixed portion 43 is clamped by the fixing portion 231 of the drive unit 2 and the fixing portion 36 of the body 6 from both directions in which the diaphragm valve body 4 abuts against and separates from the weir 35 (up and down in the figure), thereby fixing the diaphragm valve body 4 to the wear valve 5. The fixing portion 36 also has a convex portion 36a, which compresses the diaphragm valve body 4, making the external seal of the diaphragm valve body 4 stronger.

The reason why these types of wear valves are often used in beverage filling equipment is that, compared to poppet valves, the flow path structure is relatively simple and there is less liquid accumulation. From the standpoint of food hygiene, valves used in beverage filling equipment are cleaned frequently. Therefore, wear valves with a simple flow path structure are suitable.

JP 2018-62953 A

However, in the above conventional technology, when the wear valve is repeatedly opened and closed (i.e., the diaphragm valve body 4 moves toward and away from the weir 35), the thin film portion 42 of the diaphragm valve body 4 rubs against the end (protrusion 36a) of the fixed portion 36 of the body 6, causing wear of the first layer 4a and the risk of wear powder being generated.

The mechanism by which this wear occurs is as follows. As shown in FIG. 3, when the piston 25 is at the lower limit position and the diaphragm valve body 4 is in a state of abutting against the weir 35 (i.e., the wear valve 5 is in a closed state), no load is applied to the thin film portion 42 of the diaphragm valve body 4. When the valve is opened from this state, first, as shown in FIG. 7, the piston 25 starts to move upward from the lower limit position, and the diaphragm valve body 4 is elastically deformed in a direction away from the weir 35. When the diaphragm valve body 4 is elastically deformed in this way, the fixed portion 43 of the diaphragm valve body 4 is in a state of being clamped and fixed from above and below in the figure, so that the vicinity of the boundary between the thin film portion 42 and the fixed portion 43 of the diaphragm valve body 4, which was not loaded in FIG. 3, is compressed or pushed outward (in the direction of the arrow Y12) of the diaphragm valve body 4, as shown in FIG. 8.

Then, when the piston 25 is further moved upward and reaches the upper limit position, the wear valve 5 is fully open as shown in Figure 5. In this fully open state, the fixed portion 43 of the diaphragm valve body 4 is clamped from above and below in the figure, and the center of the diaphragm valve body 4 is pulled upward, so that the vicinity of the boundary between the thin film portion 42 of the diaphragm valve body 4 and the fixed portion 43, which was compressed or pressed in Figure 8, is stretched in the direction toward the center of the diaphragm valve body 4 (the direction of the arrow Y11) as shown in Figure 6.

When the valve is closed from the fully open state, the piston 25 starts to move downward from the upper limit position, and the diaphragm valve body 4 is elastically deformed in the direction of contact with the weir 35, so that the diaphragm valve body 4 returns to the state shown in FIG. 7. In other words, the vicinity of the boundary between the thin film portion 42 and the fixed portion 43 of the diaphragm valve body 4, which was stretched in FIG. 6, is once again compressed or pushed outward (in the direction of arrow Y12) of the diaphragm valve body 4.

As shown in FIG. 3, when the piston 25 moves to the lower limit position, the diaphragm valve body 4 abuts against the weir 35, and the wear valve 5 is closed, the vicinity of the boundary between the thin film portion 42 and the fixed portion 43 of the diaphragm valve body 4, which was in a compressed or pressed-in state in FIG. 7, is stretched in the direction of the arrow Y13 as shown in FIG. 4, and the thin film portion 42 returns to a state where no load is applied.

As described above, when the diaphragm valve body 4 moves in and out of contact, the vicinity of the boundary between the thin film portion 42 and the fixed portion 43 of the diaphragm valve body 4 is stretched in the directions of arrows Y11 and 13, and compressed or pushed in the direction of arrow Y12, causing friction between the diaphragm valve body 4 and the end (protrusion 36a) of the fixed portion 36 of the body 6. This friction causes wear in the first layer 4a of the diaphragm valve body 4, generating wear powder.

In a wear valve used in a beverage filling device, when wear occurs in the first layer 4a of the diaphragm valve body 4, the wear powder may be mixed into the beverage. Under the Food Sanitation Act, the PTFE that forms the first layer 4a is a material that is harmless to the human body when ingested, but wear powder large enough to be visible in the beverage is problematic in appearance. For this reason, a wear valve 5 with wear in the first layer 4a may generate large wear powder as the wear progresses, so it must be replaced before visible wear powder is generated, even if there is no problem with the function of the wear valve 5 itself. Even if there is no problem with the function of the wear valve 5 itself, having to replace it is not economical, and a wear valve that suppresses wear of the diaphragm valve body and generation of wear powder as much as possible is desired.

The present invention is intended to solve the above problems, and aims to provide a wear valve that can suppress wear powder generated by friction with the wear valve body as the diaphragm valve body moves toward and away from the wear valve.

In order to solve the above problems, the wear valve of the present invention has the following configuration.
(1) A wear valve comprising a flow path, a weir provided in the flow path, and a diaphragm valve element having a thin film portion, the thin film portion elastically deforming to cause the diaphragm valve element to move toward and away from the weir, thereby controlling a fluid flowing through the flow path, characterized in that the diaphragm valve element has a fixed portion connected to the thin film portion on an outer periphery of the thin film portion, the wear valve has a fixing portion that fixes the diaphragm valve element by clamping the fixed portion from both directions of the contact and separation, a surface of the fixing portion is coated with diamond-like carbon to suppress wear of the diaphragm valve element caused by friction between the fixing portion and the diaphragm valve element accompanying the contact and separation movement of the diaphragm valve element, and the coating is applied to a portion of the fixing portion that comes into contact with a surface of the diaphragm valve element on the side of the liquid contact surface that comes into contact with the fluid .

(2) The wear valve described in (1) is characterized in that the wear valve is an air-operated wear valve used in a beverage filling device.

(4) The wear valve according to any one of (1) to (3) is characterized in that the coefficient of dynamic friction of the coating surface is 0.1 or more and 0.2 or less.

(5) In the wear valve described in any one of (1) to (4), the diaphragm valve body is characterized in that it is composed of two layers, a first layer on the side that contacts the fluid and a second layer on the side opposite to the side that contacts the fluid, the first layer is made of fluororesin, and the second layer is made of ethylene propylene diene rubber.

The wear valve of the present invention has a diamond-like carbon coating on the surface of the fixing part that fixes the diaphragm valve body, which reduces the dynamic friction coefficient of the surface of the fixing part. If the dynamic friction coefficient of the surface of the fixing part is reduced, it is possible to suppress wear on the diaphragm valve body even if friction occurs between the diaphragm valve body and the fixing part.

When a wear valve is used in a beverage filling device, if wear occurs on the diaphragm valve body and visible wear debris gets mixed into the fluid, the wear valve must be replaced even if there is no problem with the function of the wear valve itself. However, if wear on the diaphragm valve body can be suppressed, it is possible to extend the life of the wear valve before it needs to be replaced.

FIG. 2 is a cross-sectional view of the wear valve according to the embodiment. FIG. 2 is a partially enlarged view of the X11 portion of FIG. FIG. 1 is a cross-sectional view of a prior art wear valve in a closed state. FIG. 4 is a partially enlarged view of the portion X12 in FIG. 3 . FIG. 1 is a cross-sectional view of a prior art wear valve in an open state. FIG. 6 is a partially enlarged view of the portion X13 in FIG. 5 . FIG. 1 is a cross-sectional view of a wear valve according to the prior art, showing the valve closing state. FIG. 8 is a partially enlarged view of the portion X14 in FIG. 7 . 1 shows the state of the diaphragm valve body observed from the first layer side after the diaphragm valve body was subjected to contact and separation operations 1.5 million times in a case where no coating was applied to the fixing portion. This shows the state of the diaphragm valve body observed from the first layer side after the diaphragm valve body was subjected to 1.5 million consecutive contact and separation operations when a coating with a dynamic friction coefficient of 0.15 to 0.2 was applied to the fixed portion. This shows the state of the diaphragm valve body observed from the first layer side after the diaphragm valve body was subjected to 1.5 million consecutive contact and separation operations when a coating with a dynamic friction coefficient of 0.1 to 0.15 was applied to the fixed portion. 13 is a table summarizing the results of measuring the maximum radial width of wear marks generated when the contact and separation operation was performed 500,000 times, 1,000,000 times, and 1,500,000 times.

The embodiment of the wear valve of the present invention will be described in detail with reference to the drawings.

(About the structure of the wear valve)
First, the configuration of the wear valve 1 according to this embodiment will be described with reference to Figures 1 and 2. Figure 1 is a cross-sectional view of the wear valve 1 according to this embodiment. Figure 2 is a partially enlarged view of the X11 portion of Figure 1.

The wear valve 1 is a normally closed type air operated on-off valve used in beverage filling equipment, and is composed of a drive unit 2, a body 3, and a diaphragm valve element 4 that is clamped and fixed between the drive unit 2 and the body 3.

The drive unit 2 is composed of an upper cover 21, a lower cover 22, a rod cover 23, a piston rod 24, a piston 25, and a compressor 26.

The upper cover 21 is made of, for example, aluminum die casting, and is formed in a cup shape with one end (the upper end in FIG. 1) closed and the other end open. The lower cover 22 is connected to the open end of the upper cover 21.

The lower cover 22 is made of, for example, aluminum die casting, and together with the upper cover 21, forms the piston chamber 27.

A piston 25 made of, for example, an aluminum alloy and formed into a disk shape is held in the piston chamber 27 so that it can slide freely in the vertical direction in FIG. 1, and this piston 25 divides the piston chamber 27 into an upper piston chamber 271 and a lower piston chamber 272. A spring 28 is disposed in the upper piston chamber 271 so as to be compressed by the upper wall surface of the upper piston chamber 271 and the upper end surface of the piston 25, and the spring 28 constantly biases the piston 25 toward the lower cover 22.

The upper piston chamber 271 is connected to the first operation port 211 via a through hole 213 provided on the side of the upper cover 21. The lower piston chamber 272 is connected to the second operation port 212 via a through hole 214 provided on the side of the upper cover 21.

A piston rod 24, which is inserted through a piston chamber 27, is connected coaxially to the piston 25. The piston rod 24 is formed, for example, from stainless steel or the like, into a cylindrical shape with its longitudinal direction parallel to the direction in which the piston 25 rises or falls, and protrudes downward from the piston chamber 27 through a guide hole 221 provided in the lower cover 22 in FIG. 1. The part of the piston rod 24 protruding from the piston chamber 27 is protected by a cylindrical rod cover 23 connected to the side of the lower cover 22 opposite the side of the upper cover 21.

The rod cover 23 is made of, for example, aluminum die casting. The end of the rod cover 23 opposite the lower cover 22 (the lower end in FIG. 1) is formed in a flange shape and serves as a fixing part 231 for fixing the diaphragm valve body 4.

The diaphragm valve body 4 is composed of two layers: a first layer 4a made of polytetrafluoroethylene (PTFE) and a second layer 4b made of ethylene propylene diene rubber (EPDM). The surface of the first layer 4a becomes the surface that comes into contact with the beverage, which is the fluid that flows through the flow path provided in the body 3 (hereinafter, the liquid contact surface).

A connecting portion 44 protrudes from the center of the surface of the diaphragm valve body 4 opposite the liquid contact surface, and the connecting portion 44 is connected to the piston rod 24 via the compressor 26. A contact portion 41 that contacts and separates from the weir 35 of the body 3 is provided in the center of the liquid contact surface side of the diaphragm valve body 4. A thin film portion 42 is provided on the outer periphery of the contact portion 41, and a fixed portion 43 is provided on the outer periphery of the thin film portion 42. Positioning members 45, 46 protrude from the upper and lower end faces of the fixed portion 43, respectively.

The body 3 is made of stainless steel such as SUS316L, and an input flow path 31 and an output flow path 32 form a flow path from an input port 33 to an output port 34. A weir 35 against which the diaphragm valve body 4 comes into contact is provided on the flow path so as to protrude toward the diaphragm valve body 4.

The portion of the body 3 that faces the fixed portion 231 of the rod cover 23 across the diaphragm valve body 4 is the fixed portion 36. The fixed portion 231 and the fixed portion 36 clamp the fixed portion 43 of the diaphragm valve body 4 from both directions in which the diaphragm valve body 4 abuts against and separates from the weir 35 (the up and down directions in Figures 1 and 2), thereby fixing the diaphragm valve body 4. The fixed portion 36 also has an annular protrusion 36a that is coaxial with the piston 25 and the piston rod 24 and has a radial direction perpendicular to the abutment and separation direction, and this protrusion 36a compresses the diaphragm valve body 4, making the external seal of the diaphragm valve body 4 stronger.

A diamond-like carbon coating 37 (e.g., hydrogen-containing amorphous carbon (a-C:H)) is applied to the surface of the fixed portion 36 of the body 3. This coating 37 is formed, for example, by chemical vapor deposition (CVD deposition) and has a thickness of 1 to 20 μm. The dynamic friction coefficient of the surface of this coating 37 is preferably in the range of 0.1 to 0.2, and more preferably in the range of 0.1 to 0.15. This dynamic friction coefficient is a value obtained by conducting a ball-on-disk friction test using a disk-shaped test piece whose surface is coated with the same coating as the coating 37 and a ball made of carbon-chromium bearing steel (SUJ2).

(About the operation of the wear valve)
First, a description will be given of the valve opening operation of the wear valve 1. When operating air is supplied from the second operating port 212 through the through hole 214 to the lower piston chamber 272, the pressure in the lower piston chamber 272 increases, and the piston 25 rises toward the upper piston chamber 271. At this time, the air in the upper piston chamber 271 is exhausted from the first operating port 211.

The piston 25 is connected to a piston rod 24 that passes through the piston chamber 27, so when the piston 25 rises in the piston chamber 27, the piston rod 24 rises accordingly.

Furthermore, because the diaphragm valve body 4 is connected to the piston rod 24 via the compressor 26 by the connection portion 44, when the piston rod 24 rises, the thin film portion 42 elastically deforms and the center portion of the diaphragm valve body 4 rises. As the center portion of the diaphragm valve body 4 rises, the abutment portion 41 moves away from the weir 35, and the wear valve 1 is in an open state.

Next, the valve closing operation will be explained. When the supply of operating air to the lower piston chamber 272 is stopped while the wear valve 1 is in the open state, the piston 25 descends toward the lower piston chamber 272 due to the biasing force of the spring 28. When the piston 25 descends within the piston chamber 27, the piston rod 24 connected to the piston 25 also descends.

When the piston rod 24 descends, the thin film portion 42 elastically deforms and the center of the diaphragm valve body 4 descends. As the center of the diaphragm valve body 4 descends, the abutment portion 41 abuts against the weir 35, and the wear valve 1 enters an open state.

When the diaphragm valve body 4 is repeatedly moved toward and away from the weir 35 as described above, friction may occur between the thin film portion 42 of the diaphragm valve body 4 and the end (protrusion 36a) of the fixed portion 36 of the body 6. How friction occurs between the diaphragm valve body 4 and the end (protrusion 36a) of the fixed portion 36 of the body 6 will be explained using Figures 3 to 8. Note that Figures 3 to 8 show a wear valve 5 according to the prior art, but since the configuration used in the explanation is common, the following explanation will be given as the wear valve 1 according to this embodiment.

As shown in FIG. 3, when the piston 25 is at the lower limit position and the diaphragm valve body 4 is in contact with the weir 35 (i.e., the wear valve 1 is in a closed state), no load is applied to the thin film portion 42. When the valve is opened from this state, the piston 25 first starts to move upward from the lower limit position as shown in FIG. 7, and the diaphragm valve body 4 is elastically deformed in a direction away from the weir 35. When the diaphragm valve body 4 is elastically deformed in this way, the fixed portion 43 of the diaphragm valve body 4 is in a state where it is clamped and fixed from above and below in the figure, so that the vicinity of the boundary between the thin film portion 42 and the fixed portion 43 of the diaphragm valve body 4, which was not loaded in FIG. 3, is compressed or pushed outward (in the direction of the arrow Y12) of the diaphragm valve body 4 as shown in FIG. 8.

Then, when the piston 25 is further moved upward and reaches the upper limit position, the wear valve 1 is in a fully open state as shown in Figure 5. In this fully open state, the fixed portion 43 of the diaphragm valve body 4 is clamped from above and below in the figure, and the center of the diaphragm valve body 4 is pulled upward, so that the vicinity of the boundary between the thin film portion 42 and the fixed portion 43 of the diaphragm valve body 4, which was compressed or pressed in in Figure 8, is stretched toward the center of the diaphragm valve body 4 (in the direction of the arrow Y11) as shown in Figure 6.

When the valve is closed from the fully open state, the piston 25 starts to move downward from the upper limit position, and the diaphragm valve body 4 is elastically deformed in the direction of contact with the weir 35, so that the diaphragm valve body 4 returns to the state shown in FIG. 7. In other words, the vicinity of the boundary between the thin film portion 42 and the fixed portion 43 of the diaphragm valve body 4, which was stretched in FIG. 6, is once again compressed or pushed outward (in the direction of arrow Y12) of the diaphragm valve body 4.

Then, when the piston 25 moves to the lower limit position, the diaphragm valve body 4 abuts against the weir 35, and the wear valve 5 is closed, the vicinity of the boundary between the thin film portion 42 and the fixed portion 43 of the diaphragm valve body 4, which was in a compressed or pressed-in state in FIG. 7, is stretched in the direction of the arrow Y13 as shown in FIG. 4, and the thin film portion 42 returns to a state where no load is applied.

When the diaphragm valve body 4 moves in and out of contact, the vicinity of the boundary between the thin film portion 42 and the fixed portion 43 of the diaphragm valve body 4 is stretched in the directions of arrows Y11 and 13, and compressed or pressed in the direction of arrow Y12, causing friction between the diaphragm valve body 4 and the end (protrusion 36a) of the fixed portion 36 of the body 6.

However, as shown in FIG. 2, the fixed portion 36 of the wear valve 1 is coated with a diamond-like carbon coating 37, so that even if friction occurs between the diaphragm valve body 4 and the end (protrusion 36a) of the fixed portion 36 of the body 6, wear on the diaphragm valve body 4 (first layer 4a) can be suppressed.

(Regarding the experimental results)
Below, we will explain the results of an experiment in which the diaphragm valve body 4 was subjected to contact and separation operations 500,000 times, 1 million times, and 1.5 million times in which the size of wear marks generated on the diaphragm valve body 4 was compared in cases where no coating 37 was applied to the fixed portion 36 (convex portion 36a), where a coating 37 with a kinetic friction coefficient of 0.15 to 0.2 was applied, and where a coating 37 with a kinetic friction coefficient of 0.1 to 0.15 was applied.

Figure 9 shows the state of the diaphragm valve body 4 observed from the first layer 4a side after the diaphragm valve body 4 has been subjected to 1.5 million contact and separation movements in a case where the coating 37 is not applied to the fixed portion 36 (protruding portion 36a) (i.e., a wear valve 5 according to the prior art).

When the diaphragm valve body 4 is subjected to 1.5 million successive contact and separation operations without applying the coating 37 to the fixed portion 36 (protrusion 36a), it can be seen that an arc-shaped wear mark S11 is generated on the thin film portion 42, as shown in FIG. 9. The wear mark S11 is arc-shaped because the protrusion 36a is provided in an annular shape, and friction occurs between this protrusion 36a and the thin film portion 42. The radial width of the wear mark S11 is a maximum of approximately 400 μm (see FIG. 12).

Furthermore, when the contact and separation operations were performed 500,000 times and 1,000,000 times, the maximum radial width of the wear mark S11 was 190 μm at 500,000 times and 270 μm at 1,000,000 times, as shown in FIG. 12.

Figure 10 shows the state of the diaphragm valve body 4 observed from the first layer 4a side after the diaphragm valve body 4 was subjected to 1.5 million consecutive contact and separation movements when a coating 37 with a dynamic friction coefficient of 0.15 to 0.2 was applied to the fixed portion 36 (protrusion 36a).

When the fixed portion 36 (protruding portion 36a) is coated with a coating 37 having a dynamic friction coefficient of 0.15 to 0.2 and the contact and separation operation is performed 1.5 million times in succession, arc-shaped wear marks S12 are generated on the thin film portion 42, as shown in FIG. 10. However, it can be seen that the range in which the wear marks S12 are generated is smaller than the range in which the wear marks S11 shown in FIG. 9 are generated. Furthermore, the radial width of the wear marks S12 is a maximum of approximately 200 μm (see FIG. 12), which is approximately half the width of the wear marks S11 when the coating 37 is not applied.

Furthermore, when the contact and separation operations were performed 500,000 times and 1,000,000 times, the radial width of the wear mark S12 was a maximum of 100 μm after 500,000 times and 145 μm after 1,000,000 times, as shown in FIG. 12.

Figure 11 shows the state of the diaphragm valve body 4 observed from the first layer 4a side after the diaphragm valve body 4 was subjected to 1.5 million consecutive contact and separation movements when a coating 37 with a dynamic friction coefficient of 0.1 to 0.15 was applied to the fixed portion 36 (protrusion 36a).

When a coating 37 with a dynamic friction coefficient of 0.1 to 0.15 is applied to the fixed portion 36 (protruding portion 36a) and contact and separation operations are performed 1.5 million times in succession, wear marks S13 are generated on the thin film portion 42 as shown in FIG. 11. However, it can be seen that the range in which the wear marks S13 are generated is smaller than the range in which the wear marks S11 shown in FIG. 9 are generated, and is even smaller than the range in which the wear marks S12 shown in FIG. 10 are generated. Furthermore, the radial width of the wear marks S13 is a maximum of approximately 150 μm (see FIG. 12), which is approximately one-third of the wear marks S11 when the coating 37 is not applied.

Furthermore, when the contact and separation operations were performed 500,000 times and 1,000,000 times, the radial width of the wear mark S13 was a maximum of 90 μm after 500,000 times and 100 μm after 1,000,000 times, as shown in FIG. 12.

As described above, the wear valve 1 of the present embodiment has the following features:
(1) A ware valve 1 comprising a flow path (e.g., an input side flow path 31 and an output side flow path 32), a weir 35 provided in the flow path, and a diaphragm valve element 4 having a thin film portion 42, the thin film portion 42 elastically deforming to cause the diaphragm valve element 4 to move toward and away from the weir 35, thereby controlling the fluid (e.g., a beverage) flowing through the flow path, the diaphragm valve element 4 comprising a fixed portion 43 connected to the thin film portion 42 on the outer periphery of the thin film portion 42, the ware valve 1 comprising fixing portions 231, 36 which fix the diaphragm valve element 4 by clamping the fixed portion 43 from both directions of the contact and separation, and a coating 37 of diamond-like carbon applied to the surface of the fixing portion 36, thereby suppressing wear of the diaphragm valve element 4 caused by friction between the fixing portion 36 and the diaphragm valve element 4 as the diaphragm valve element 4 moves toward and away from the weir 35.

(2) The wear valve 1 described in (1) is characterized in that it is an air-operated wear valve used in a beverage filling device.

(3) In the wear valve 1 described in (1) or (2), the coating 37 is applied to the portion of the fixing portion 231, 36 that contacts the surface of the diaphragm valve body 4 that contacts the fluid (beverage) (e.g., the surface of the fixing portion 36).

(4) The wear valve 1 described in any one of (1) to (3) is characterized in that the kinetic friction coefficient of the surface of the coating 37 is 0.1 or more and 0.2 or less.

(5) In the wear valve 1 described in any one of (1) to (4), the diaphragm valve body 4 is characterized in that it is composed of two layers, a first layer 4a on the side that contacts the fluid (beverage) and a second layer 4b on the side opposite to the side that contacts the fluid (beverage), the first layer 4a is made of a fluororesin (e.g., PTFE), and the second layer 4b is made of ethylene propylene diene rubber.

In the wear valve 1 having the above configuration, the surface of the fixing part 36 that fixes the diaphragm valve body 4 is coated with a diamond-like carbon coating 37, which reduces the dynamic friction coefficient of the surface of the fixing part 36. If the dynamic friction coefficient of the surface of the fixing part 36 is reduced, it is possible to suppress the occurrence of wear (wear marks S11, S12, S13) on the diaphragm valve body 4 even if friction occurs between the diaphragm valve body 4 and the fixing part 36.

Conventionally, when a wear valve is used in a beverage filling device, a wear valve with wear (wear marks S11, S12, S13) on the diaphragm valve body 4 is at risk of generating large wear particles as the wear progresses, and so even if the wear valve itself is not in poor function, it must be replaced before visible wear particles are generated. However, if wear on the diaphragm valve body 4 can be suppressed, as in the wear valve 1 of this embodiment, it is possible to extend the life of the wear valve 1 before it needs to be replaced.

Note that this embodiment is merely an example and does not limit the present invention in any way. Naturally, therefore, the present invention can be improved and modified in various ways without departing from the spirit of the invention. For example, in this embodiment, the coating 37 is applied to the surface of the fixing portion 36, but the area to which the coating 37 is applied is not limited to this, and it may be applied only to the surface of the protruding portion 36a of the fixing portion 36, or it may be applied to the entire surface of the body 3. Also, the fixing portion 36 does not necessarily have to have the protruding portion 36a, and may be a flat surface.

REFERENCE SIGNS LIST 1 wear valve 4 diaphragm valve body 31 input flow path 32 output flow path 35 weir 36 fixing portion 37 coating 42 thin film portion 43 fixed portion 231 fixing portion

Claims (4)

A wear valve comprising a flow path, a weir provided in the flow path, and a diaphragm valve element having a thin film portion, the thin film portion elastically deforming to cause the diaphragm valve element to move toward and away from the weir, thereby controlling a fluid flowing through the flow path,
the diaphragm valve body includes a fixed portion connected to the thin film portion on an outer periphery of the thin film portion;
the wear valve includes a fixing portion that fixes the diaphragm valve body by clamping the fixed portion from both directions of the contact and separation;
a surface of the fixing portion is coated with a diamond-like carbon coating, thereby suppressing wear of the diaphragm valve body caused by friction between the fixing portion and the diaphragm valve body accompanying the contact and separation movement of the diaphragm valve body;
the coating is applied to a portion of the fixing portion that comes into contact with a surface of the diaphragm valve body on a side of a liquid-contacting surface that comes into contact with the fluid;
It is a liquid-contact surface.
Wear valve featuring. 2. The wear valve of claim 1,
The wear valve is an air-operated wear valve used in a beverage filling device;
Wear valve featuring. The wear valve according to claim 1 or 2 ,
The coefficient of dynamic friction of the surface of the coating is 0.1 or more and 0.2 or less;
Wear valve featuring. 4. The wear valve according to claim 1 ,
The diaphragm valve body is
The membrane is composed of two layers, that is, a first layer on the side that contacts the fluid and a second layer on the opposite side to the side that contacts the fluid;
the first layer is formed of a fluororesin;
the second layer is formed of ethylene propylene diene rubber;
Wear valve featuring.

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