JPS6367071B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a pinch valve that is particularly resistant to abrasion caused by slurry and has a built-in tube made of a strong rubber-like elastic material and has a removable structure. Conventionally, diaphragm valves have been commonly used as slurry valves, but in diaphragm valves, the fluid flow path is curved with the diaphragm as a boundary, so the direction of fluid flow can be changed. In the vicinity of the diaphragm, the fluid flows quickly and the friction between the diaphragm and the fluid is large, causing the problem of diaphragm wear due to solid particles in the slurry, and also deformation or damage under high vacuum or high pressure. Without,
There are problems such as having to achieve a sufficiently reliable distribution and blocking effect, and solving these problems has been an extremely difficult proposition. In view of the above points, the present invention is provided with a tube that is less abraded by slurry and that can reliably provide a flow and cutoff effect without being deformed or damaged even under high vacuum or high pressure. The purpose is to provide a pinch valve that can be replaced. In order to solve these problems, the inventor of the present invention has conducted various studies and has built a straight tube made of a rubber-like elastic material that has two integrated layers: a side in contact with fluid that has low hardness and a side that does not come in contact with fluid that has high hardness. We have developed a pinch valve that blocks fluid flow by operating a pair of compressors placed on opposite sides of a tube using cams, and has a structure in which the tube can be easily disassembled and replaced. Preferred embodiments of the present invention will be described in detail below. First, regarding the wear problem caused by slurry, in consideration of the friction between the slurry and the diaphragm due to the curved flow path of the diaphragm valve, a straight tube made of a rubber-like elastic body parallel to the flow path direction is used, and the slurry and tube are We decided to significantly reduce friction. Furthermore, regarding wear issues, the hardness measured by a shoadurometer, which has relatively low hardness,
A rubber-like elastic material with high elasticity of 40° to 50° is placed on the inner circumference of the tube on the side that comes into contact with the fluid, while in case of denting, expansion, or breakage under high vacuum or high pressure, a rubber-like elastic material with high elasticity is placed on the non-contact side of the outer circumference of the tube. The hardness of the fluid side is 60° or more using a relatively hard sillometer.
By making the tube a 70° rubber-like elastic body and having a two-layer integral structure, we were able to solve all the problems of conventional diaphragm valves at once. The reason why the hardness of the rubber-like elastic body used on the fluid-contact side of the tube is specified as 40° to 50° by a shoadyrometer is because if the hardness is greater than 50°, the wear of the rubber-like elastic body due to slurry is extremely large. Also, if the hardness is less than 40°, the wear becomes extremely severe and it becomes unusable.
Similarly, the hardness of the rubber-like elastic body used on the side not in contact with the fluid is
The reason for specifying 60° to 70° is that if the hardness is greater than 70°, the vacuum resistance and pressure resistance are excellent, but on the other hand, the sealing performance when closing the tube becomes poor; If the hardness is smaller than 60°, the vacuum resistance and pressure resistance will be 20 to 50% worse than those with hardness of 60° to 70°. Another purpose of changing the hardness of the fluid-contacting side and the non-fluid-contacting side is to facilitate the return of the tube to its circular shape when the tube is changed from a closed state to an open state. In the case of a single tube made of a material with low hardness, it is difficult for the tube to return to its circular shape when the tube is changed from a closed state to an open state. Furthermore, the reason why the pinch valve of the present invention has a structure that can be disassembled is that the rubber-like elastic tube, which is the main component, can be replaced. It is also possible to fix the cam body and its cover, and the fitting part of the housing and body cap with adhesive.
In this case, when the tube is worn out by the slurry and needs to be replaced, it becomes impossible and the entire pinch valve must be replaced, resulting in a large loss. The rubber-like elastic body used in the present invention is natural rubber, synthetic rubber, etc. Natural rubber includes gum arabic, and synthetic rubber includes diene rubber such as butadiene rubber (SBR, NBR), isoprene rubber, chloroprene rubber, etc. There are olefin rubbers such as butyl rubber, ethylene propylene terpolymer (EPT), and chlorosulfonated polyethylene (CSM). Embodiments of the present invention will be described below with reference to the drawings. 1 is a tube made of rubber-like elastic material,
It is covered and supported by a pair of housing members 2. The flange portions 1a provided at both ends of the tube are in contact with both ends of the housing member 2, and their outer diameters are slightly smaller than the outside diameter of the ends of the housing member 2. Also, an annular projection 1b (Fig. 2) provided integrally on the outer periphery of the flange portion 1a.
is fitted into the annular groove 6a of the body cap 6 to fix the tube 1. The outer diameter of the straight tube portion is set to be approximately the same as the inner diameter of the housing member 2. 1c is a rubber-like elastic body with a hardness of 40° to 50° on the inner periphery of the tube that comes into contact with the fluid, and 1d is the outer periphery of the tube that does not come into contact with the fluid, and has a hardness measured by a shoadurometer of 40° to 50°. It is made of a rubber-like elastic body with a hardness of 60° to 70°. The thickness of the tube in contact with the fluid 1c and the side 1d not in contact with the fluid is not particularly limited, but the thickness on the side in contact with the fluid is approximately 1/3 to 1/4 of the total thickness, and the thickness on the non-contacted side is approximately 1/3 to 1/4 of the total thickness. The one that occupies 2/3 to 3/4 is good. The tube 1 composed of both the inner and outer layers 1c and 1d is
The layers 1c and 1d may be integrated by adhesive,
Alternatively, both may be integrally formed by integral molding. At the interface between the layers 1c and 1d when integrally molded, the materials of both layers penetrate and mix with each other, exhibiting a tightly bonded state, and no boundary line appears and does not peel off during use. In order to improve the strength of the tube 1, two or three pieces of coarse or fine mesh cloth may be laminated inside the tube. Now, a manufacturing method by integral molding of the tube, which is preferably used in the present invention, will be explained.
First, a layer with a hardness of 40° to 50° with a reduced amount of carbon is semi-vulcanized to reduce the process oil and form a rough plate-shaped body. Separately, a layer of homogeneous rubber with a hardness of 60° to 70° and a large amount of carbon is semi-vulcanized to reduce the process oil, and the flow is adjusted with the layer of lower hardness to produce a rough plate-shaped body. Next, wrap a rubber plate with a hardness of 40° to 50° around the circular core mold, and
Wrap a 60° to 70° rubber plate around it. It is sandwiched between upper molds, heated, pressurized, and vulcanized to make the two stick together. The purpose of pre-forming both the hard and soft layers is to prevent the tube from becoming deformed because it is thinner than the diaphragm of a diaphragm valve. Heating during final molding is done in stages as much as possible, starting from 135° to 145°C and increasing the temperature to 165° to 170°C over 25 to 30 minutes. Figure 6 shows heating temperature rise curve 1 during molding.
Give an example. Although the temperature is raised in three stages, the temperature may be raised in two stages. The cross section of the tube is generally a perfect circle, but in order to improve the sealing performance at both ends 1'' (Fig. 4) where the tube becomes wider when the tube is closed, it is shown in Fig. 5. As shown, the inner circumferential surface of the 1" part is an arcuate surface with a width of ±15 degrees from the horizontal axis, with the inner diameter of the tube as the radius,
The wall thickness may be made slightly thicker. A pair of housings 2 serve to cover and support the tube 1 from both sides. In the center of the housing 2, there is a holding part 2a for the compression body 3, which has an outer diameter larger than the outer diameter of the tube end, and a slot 2b that facilitates vertical movement of the compression body 3, and a projection 3a provided on the compression body. A guide groove 2c is provided that slides into engagement with the guide groove 2c. Immediately on both sides of the holding portion 2a are male threaded portions 2d, which are adapted to fit into the male threaded portions 6b of the body cap 6. Reference numeral 2e denotes a wide notch provided at the center of the interior of the housing 2, which receives the tube 1' (FIG. 4), which has expanded in width when the tube is closed. Reference numeral 3 denotes a pair of compression bodies, which are placed opposite to each other on both sides of the tube, and whose cam engaging ribs 3b engage with a spiral stepped surface 4a inside the cam body, and move up and down as the cam body 4 rotates, thereby tightening the tube 1. Perform opening/closing operations. The head portion of the engaging rib 3b is provided with a step-like notch, which serves to prevent slippage that occurs when engaging with the cam surface 4a. There are protrusions 3a on both sides of the engagement rib 3b, which slide into engagement with the guide groove 2c of the housing 2 to prevent the compression body from moving left and right and to facilitate vertical movement. The scissors 3c in contact with the tube 1 has a horizontal surface, and its length is longer than the tube width which becomes wide when the tube 1 is compressed. (Figure 4). This is to improve the sealing performance when the tube 1 is closed. Reference numeral 6 designates a body cap whose female threaded portion 6b is fitted into the male threaded portion 2d of the housing 2 to fix the housing, and at the same time receives the flange portion protrusion 1b of the tube into an annular groove 6a provided inside. The depth of the annular groove 6a is set such that when the tube 1 is closed, the tube is slightly compressed to the extent that the tube is not deformed, so as to alleviate the stress caused by the deformation of the flange portion projection 1b when the tube 1 is opened. . On the outer periphery of the body cap, there is an annular raised part 6c having the same outer diameter as the outer diameter of the sockets 4b and 5a of the cam body 4 and the cam cover 5, and holes 6d for tightening screws 7 are provided at several places. be. This tightening screw 7 connects the housing 2 and the body cap 6.
This prevents the fitting screws 2d and 6b from loosening when the cam cover 5 is rotated. The tightening screw hole 6d is located outside the male threaded portion 2d of the housing to prevent damage to the thread. Reference numerals 4 and 5 denote a cam body and a cam cover, respectively, which are fitted through threaded portions 4c and 5b, and enclose a tube and a housing. Cam body 4
There is a gently spiral step-like cam surface 4a inside the cam body, and the rotation of the cam body 4 causes the engagement rib 3b of the compression body to move up and down, thereby opening and closing the tube 1. FIGS. 3 and 4 are sectional views taken along the line A-A' showing only the cam body, compression body, and tube when the tube is opened and closed. Holes 4d and 5c for set screws 8 are provided in the fitting part of the cam body and cam cover.
are provided, and after fitting them together, tighten the set screws 8 and 4.
By inserting it into holes d and 5c, it is possible to prevent the screws from loosening due to rotation of the cam body. Furthermore, several holes 5d for fixing screws 10 for fixing the handle 9 are provided on the outer periphery of the cam cover 5.
Fix the handle 9 to the cam cover 5 with a set screw 10, aligning it with the set screw hole 9a. The handle 9 is provided to facilitate the rotation of the cam body 4 and the cam cover 5. By protruding the handle in the axial direction, the handle 9 is made compact as a whole and is mounted so that it can be easily operated from any position. There is. Next, the procedure for assembling the pinch valve of the present invention will be briefly explained. (1) First, cover the tube 1 with a pair of housings 2 from both sides. (2) Insert the pair of compression bodies 3 into the slot 2 of the housing 2.
b and guide groove 2c. (3) Insert the cam body 4 into one half of the housing 2. (4) Insert the cam cover 5 into one half of the housing 2. (5) Screw the cam body 4 into the cam cover 5. (6) Screw the body cap 6 onto both sides of the housing 2. (7) Screw the tightening screw 7 into the hole 6d of the body cap 6. (8) Fix the set screws 8 in the holes 4d and 5c of the cam body and cam cover. (9) Insert the handle 9 into the cam cover 5, and insert the set screws 10 into the holes 5d and 9a to secure it. Summary: By reversing the above steps, the pinch valve of the present invention can be easily and quickly disassembled. Below, the results of comparative tests regarding abrasion resistance, pressure reduction resistance, and sealing properties are shown between a tube made of synthetic rubber suitable for the apparatus of the present invention and a tube having uniform hardness. The test results for abrasion resistance and sealing properties were obtained when water containing manganese dioxide was passed through, and the abrasion resistance was expressed as the number of days it took for the tube to wear out.

[Table] As can be seen from this result, the tube used in the present invention had a service life of only 20 days for a tube with a uniform hardness of 60°, but the service life increased significantly to 260 days, and the replacement cost increased significantly. decreased sharply. For reference, the diaphragm had a service life of only 10 days in the same test. As explained above, the pinch valve of the present invention has sufficient strength against deformation or destruction even under high vacuum or high pressure due to the non-contact side of the tube, which is the main component, and has a circular shape when opened. It has a large restoring force, and has a tube that can withstand abrasion caused by solid particles in the fluid on the fluid contact side and achieves a reliable seal when the tube is blocked, and is manufactured at a low cost with a compact structure that allows the tube to be replaced. It has become a device that can do this. Note that the pinch valve in the present invention is not limited to use with slurry, but can also be used with gaseous fluids containing fine particles.

[Brief explanation of drawings]

Figure 1 is an exploded view of the pinch valve, Figure 2 is a vertical sectional view of the pinch valve, and Figure 3 is the A of the pinch valve.
-A' line sectional view (however, only the main components are shown when the tube is open), Figure 4 is the same as Figure 3, but when the tube is closed, Figure 5 is a cross-sectional view of another example tube, and Figure 6 is a cross-sectional view of another example tube. The figure is a graph showing an example of a heating temperature rise curve during integral molding, with temperature plotted on the vertical axis and time plotted on the horizontal axis. In these drawings, 1...tube, 1a
...flange part, 1b... annular projection, 1c... fluid contact side (inner periphery), 1d... non-fluid contact side (outer periphery), 2... housing, 2a... compression body holding part,
2b...Slot, 2c...Guide groove, 2d...
Male screw part, 2e... Notch part, 3... Compression body, 3a
...Protrusion, 3b...Engaging rib, 3c...Scissors, 4...Cam body, 4a...Cam surface, 4b...
...Socket part, 4c...Screw part, 4d...Hole for set screw, 5...Cam cover, 5a...Socket part, 5b...
...Screw part, 5c, 5d...Hole for set screw, 6...
Body cap, 6a... Annular groove, 6b... Female threaded portion, 6c... Annular raised portion, 6d... Hole for tightening screw, 7... Tightening screw, 8, 10... Set screw, 9
...Handle, 9a...Hole for set screw.

Claims (1)

[Claims] 1. A housing, a tube made of a rubber-like elastic body disposed with both ends supported within the housing, and a pair of compressors disposed oppositely on both sides of the tube and engaged with the housing. A cam comprising a cam body and a cam cover that abuts against the pair of compression bodies and moves the compression bodies simultaneously to open and close the tube, and a body cap connected to both ends of the housing. , the tube made of the above-mentioned rubber-like elastic body has a hardness of 40° to 50° on the side in contact with the fluid measured by a shoal adjurometer, and a hardness of 60° to 70° on the side not in contact with the fluid 2
1. A pinch valve having an integral layer structure, and having a structure in which a body cap and a housing, a cam cover and a cam body are screwed together, and the tube is replaceable.