JPS61286673A - Pinch valve - Google Patents

Abstract

PURPOSE:To prevent a crack from occurring and growing up, by processing an inner wall of a tapering type projection part directing its vertical angle outward coherently tight into nonpenetration of a fluid, while pressing and locking it tight enough with a clamping metal device. CONSTITUTION:A projection part A is formed in a pressure-pinching part for controlling a fluid flowing inside a circular tube body. This projection part, making the inner wall side the base 1d, is of an acute-angle triangle form having a vertical angle 1e, and installed symmetrically pairwise on a horizontal axis. An inner wall 1c of the projection part A, after being coated with a bonding agent suitable for a tube material, is pressurized by a press and coherently processed tight enough. Proper roundness is provided for a tip end of the inner wall of the vertical angle part 1e as well, and a sectional circular circular boss part 1b being fitted in a clamping metal device and pulling the tube is installed at the side of an outer wall in advance of the inner wall tip, doubling as crack growth prevention.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is used as an ultra-clean valve for semiconductor, pharmaceutical and food plants, or as an ultra-hygienic valve in the field of biotechnology. In order to prevent chemical changes due to accumulation or the generation of bacteria, the tube body is made of a flexible tube with a direct passage through which the fluid passes.
The present invention also relates to a pinch valve that can withstand repeated compression and has both durability and pressure resistance even when it is made of a resin-based material with excellent corrosion resistance.

(Prior Art) Most of the performance of a pinch valve is determined by the material of the flexible chip body and the shape of the stress generating area during compression. Most of the tube bodies of industrial pinch valves manufactured using conventional technology are made of elastomer, and those made of resin materials such as tetrafluoroethylene resin (trade name: Teflon), which has excellent chemical resistance, are extremely The reality is that there are few. This is because, in general, resin-based materials are more prone to cracking at bent ends during repeated compression than synthetic rubber-based materials.

Next, a known example will be explained using figures.

FIG. 6A is a longitudinal cross-sectional view of a standard circular tube with a chive body in an open state, and FIG. 6B is a cross-sectional view of FIG. 6A in a closed state. With this standard shape, the tube body is
When made of resin, it is used in the medical field under conditions of low pressure, relatively few repeated compressions, and limited to short-term use, while synthetic rubber is used at low pressure and with low operating frequency. Used for piping for water, air, etc. In both cases, cracks occurred from the zero point of the bent end due to repeated compression, and eventually led to breakage.

Figures 7 and 8 are described in Japanese Patent Publication No. 55-10790, in which P is used as the material for the tube body.
It was developed primarily for use with resin materials such as TFE (tetrafluoroethylene resin), which lack elasticity and are easily bent and cracked.

It consists of a fluid-impermeable filler piece 21 attached to the inside of the tube 20 and a fastening fitting 22.23, with the fastening fitting 22.23 surrounding the filler piece 21.
This relates to a pinch valve that surrounds, compresses and fixes the side of the tube 20, and pinches the remaining portion in the middle of the tube to control fluid. The problem with this structure is that the tube does not have a special overhang.
By inserting the filler piece 21 into the inner wall of the circular tube and fitting it with a fastening fitting, it is difficult to make the insertion site fluid impermeable, such as by tightly fitting the filler piece in the direction of the end face 21a.

Fig. 9 shows a chive body molded from an elastic or flexible material, which is described in Japanese Patent Publication No. 44-12466, and has flanges 24 at both ends, a curved part in the center, and a curved part in the center. This relates to a pinch valve in which outwardly directed protrusions 25 are provided on both left and right walls of the pinch valve. With this structure,
A particular problem is that a protrusion is provided at the bent end, and there is no way to stop the growth of cracks.

Although the known examples have been described above, all of them have structures that have some kind of drawback and cannot exhibit sufficient functionality.

(Problem to be Solved by the Invention) When the tube body is repeatedly bent by pressure and the inner wall is brought into close contact with each other, the starting point C of the bent end (the sixth
Figure B) becomes an acute angle, and a crack occurs from this part.
Eventually, a pressure leak occurred and the tube body was damaged. In particular, when molding tube bodies using resin materials such as tetrafluoroethylene resin, which has excellent corrosion resistance, it has inferior anti-blow elasticity compared to synthetic rubber materials, and its resistance to cracking due to repeated compression is currently low. Well, it's a few steps worse. Therefore, the position of the starting point C and the development of the end face shape are important points.

(Means for solving the problem) When the tube body is compressed and the inner wall is brought into close contact, an overhang A is set at the bent end in anticipation of cracking, and the overhang A is As a measure to prevent crack growth, the following shape and mechanism will be provided.

a. Process the inner wall of the overhang to make it fluid-impermeable.

b. In order to further improve the adhesion, fit the protruding part with a fixing metal fitting.

A boss portion with a circular cross section is provided on the outer wall portion of the C overhang portion at the apex angle 1c to prevent crack growth.

In addition, in order to ensure compression and expansion of the tube body, boss parts are provided on the top and bottom, left and right sides of the tube, and these parts are fitted with the dovetail-shaped parts of the metal fittings, and the left and right fixing metal fittings are connected to the boss parts. A mechanism is provided that links the press table that presses the top and bottom together.

(Function) (1) An overhang A is provided in advance at the bent end of the tube body when the tube body is tightly compressed, extending outward from the inner diameter side from the crack initiation point C. The entire inner wall to the overhanging part, including the generation point C, is formed of a smooth flat surface, and this inner wall is pressed with an adhesive suitable for the material or after treatment such as heating, using a press. Strong adhesion processing is done. +4 Mechanically, the entire surface of the overhang A is fitted with a fixing metal fitting to supplement the adhesion.
It is now possible to prevent crack growth. Furthermore, since the stress acting area due to the clamping pressure is provided inside the overhanging portion A and the starting point of crank occurrence, no abnormal stress is applied to the overhanging portion A.

(2) When a resin material with poor anti-dust elasticity was used as the material for the tube body and the tube was left sealed for a certain period of time, plastic deformation often caused accidents in which the tube did not open with internal pressure alone. .

In the structure of the present invention, tensile boss portions 1alb are provided on the top and bottom, left and right sides of the tube, and the boss portions are connected to the fixing metal fittings 4.
, and of the press base 2.3.

Each is tightly fitted into a dovetail-shaped hole. When the valve is closed, the upper and lower pressing bases press toward the center line of the horizontal axis, and the left and right fixing fittings move away toward the bent end. Next, when the valve is opened, the upper and lower press bases move away from the center of the vertical axis, and the left and right fixing fittings move closer to the center of the vertical axis, thereby interlocking the tube toward the opening side.

In this way, since the structure is such that the valves are forcibly operated in conjunction with each other by the link, opening and closing of the valve is ensured.

(Example) Hereinafter, specific examples of the present invention will be described based on the drawings.

1st. Figures A, IB, and 10 show the structure of the tube body 1. The cross section in the direction perpendicular to the flow has a circular tube shape, and an overhang A is provided at the part to be compressed to control the fluid. It is formed. As shown in FIG. 1C, the projecting portions A have an acute triangular shape with a base 1d facing the inner wall and an apex angle 1e, and are provided in pairs on the left and right sides on the horizontal axis. The shape of the projecting portion in the horizontal direction with respect to the flow is 1A.
As shown in the figure, the upper and lower sides are axially symmetrical with large R, and both R
It is constructed by connecting the joints of the
This enables close contact treatment of the inner wall 1c of the projecting portion. Then the first
The tip of the inner wall of the apex portion 1e in Figure C is also appropriately rounded, and on the outer wall beyond that, there is a boss portion 1b with a circular cross section that is fitted into the solid bottom fitting 4 and pulls the chive. , is provided to also prevent crack growth. Also on the vertical axis passing through the center, a handle portion 1g and a tensioning boss portion 1a having a circular cross section and fitted onto the press base 2 are provided on the upper and lower outer walls of the tube.

Although the illustration shows a single-layered embodiment made of resin-based material, for use with high-pressure fluids, the outer cover may be laminated and reinforced with elastomer or the like to improve pressure resistance.

FIG. 2 shows a state in which a fixing fitting 4, which also serves to prevent crack growth, is attached to the tube body 1. In the tube body 1, from the state shown in FIG. 1, the inner wall 1c of the projecting portion A is coated with an adhesive suitable for the tube material, and then pressurized with a press to adhere the inner wall 1c. Note that the adhesion treatment is carried out by a method suitable for the material, such as heating only or a combination of adhesive and heating, depending on the tube material.

Furthermore, the overhanging part A, which has been closely treated with the inner wall IC, is attached to the fixing metal fitting 4.
It is fitted into a boss groove 4b and a slot groove 4c attached to the boss groove 4b and is tightly assembled with a tightening bolt 12. The fixing fitting 4 is integral and has a round hole 4a at one end.
A slot groove 4c is cut from the round hole toward the other end, and a boss portion 1 attached to the tube body 1 is formed in a part of this groove.
A boss groove 4b is provided in which the boss 4b is fitted. Also,
A threaded portion is provided on the lower surface of the slotted groove between the end of the round hole 4a and the boss groove 4b, and a through hole is provided on the upper surface.
A tightening bolt 12 is screwed together. The reason why the fixing bracket 4 is made into an integral type is to prevent the screws from loosening by utilizing the rebound elasticity, and to make the overhanging part A more tightly attached. It has the advantage of having a small number of parts and being easy to process.

FIG. 3 shows another embodiment of the fixing fitting 4 shown in FIG. 2, and has a structure in which the round hole 4a and the tightening bolt 12 are omitted.
The fixing method involves heating the metal fixture alone to an appropriate temperature, expanding the dimensions of the slotted part by thermal expansion, fitting the overhang part A of the tube body 1, and finally letting it cool to room temperature. This is a method in which the fitted part is tightly tightened by shrinkage, and after the protruding part of the tube body is fitted into the fixing fitting, the fixing fitting is pressed with a press to cause plastic deformation to the metal part. A method of raising the skin and tightening it tightly is also practiced.

4th. Figures A and 4B show the fluid controlled by the linked action of the links. Figure 4A shows the valve in the open state, and Figure 4B shows the
It is a sectional view showing a state in which the valve is closed. The boss portions 1a11b of the tube body 1 are connected to the upper and lower press bases 2, respectively.
．． 3 and the boss grooves 4b of the left and right fixing fittings 4. In addition, as shown in the figure, two pairs of pin holes are provided between the upper press base 3 and the upper part of the left and right fixing brackets 4, and between the lower press base 2 and the lower part of the left and right fixing brackets 4, respectively, so that the link pin 6 and the link They are connected by attaching a plate 5.

The coil spring 16 provides an auxiliary force to press the fixing fitting 4 in the vertical axis direction passing through the center. In the case of a small diameter tube body, the link mechanism can be omitted and only the coil spring 16 is used. , operation is possible.

FIG. 5A is a cross-sectional view of an assembled tube body according to the present invention, with the valve closed.

The tube body 1, upper and lower pressing stands 2.3, left and right fixing fittings 4, link pins 6, and link plates 5 are installed as shown in Figures 4A and 4B.

The left-hand threaded portion 7b of the stem 7 is connected to the upper pressing base 3, and
The right-hand threaded portion 7a is screwed onto the lower press base 2. By rotating the handle 9 fitted to the stem 7 clockwise or counterclockwise, the upper and lower pressing bases 2.3 and the fixture 4 are linked by a link mechanism, and the tube body 1 is moved to the compression side. Alternatively, a pulling motion toward the opening can be used to open and close the valve to control fluid flow.

The positioning bolt 10 is disposed between the main body frame 8 and the lower pressure base 2, and between the upper pressure base 3 and the lower pressure base 2, each of which is a rotation stopper for linear movement. be.

The main body frame 8 can be held and fixed to a valve holding plate 13 attached to a piping device using mounting bolts 14.

FIG. 5B is a partially sectional side view of FIG. 5A. The shape of both ends of the tube body 1 is a scissor flange shape.
Alternatively, a shape suitable for the piping connection method is set, such as a plug-in socket type.

(Effects of the Invention) (1) A crack initiation point is set in advance inside the bent portion of the tube body due to pressure, and a projecting portion is provided outward from this starting point to prevent stress such as internal pressure, compression, tension, etc. It was outside the area of action.

Furthermore, since the shape of the inner wall of the projecting portion is configured to facilitate close contact, it is possible to reliably achieve close contact treatment to make the projecting portion impermeable to fluids. Furthermore, since a fixing metal fitting was fitted to reinforce the adhesion treated part, the adhesion between the inner wall of the overhanging part became even stronger, thereby preventing the occurrence and growth of cracks.

(2) Boss parts that serve both to maintain the position of the tube and for tension, and dovetail grooves attached to the press base and fixing metal fittings are fitted on the top and bottom, left and right sides of the outer wall of the tube body, and both metal fittings are connected to each other. Since the valves were operated in tandem, the valves could be opened and closed reliably.

As a result of the above, an industrial pinch valve has been developed that is accurate and durable in repeated opening and closing operations over a long period of time.

[Brief explanation of the drawing]

FIG. 1A is a horizontal cross-sectional plan view of the tube body of the pinch valve according to the present invention in an open state; FIG. 1B is a cross-sectional view taken along line X-X in a direction perpendicular to the flow of the tube body;
Fig. 1C is an enlarged sectional view of the overhanging part A of the chive body, Fig. 2 is an enlarged partial sectional view of Fig. 1B with fixing fittings provided, Fig. 3 is another embodiment of Fig. 2, and Fig. 4A Figure 1B is a sectional view of the valve in the open state when the link mechanism is installed, and Figure 4B is a sectional view of the valve in its open state.
5A is a front sectional view of an assembled embodiment according to the present invention, and FIG. 5B is a partially sectional side view of FIG. 5A. FIG. 6A is a front sectional view of the conventional tube body in the valve open state, FIG. 6B is a sectional view of the conventional tube body in the compressed valve closed state,
FIG. 7 is a partial sectional view of a tube body of a known type, FIG. 8 is an exploded perspective view of the fasteners etc. of FIG. 7, and FIG. 9 is a sectional view of a tube body of another embodiment of a known type. In the drawings, 1...Tube body 2...Lower press base 1a...Tensile boss portion 2a...Dovetail groove 1b
・Boss part for fixing fittings 3 ・Upper pressure base IC・・
-Inner wall of the overhang 4...Fixing bracket 1d...Base of the overhang 4a...Round hole 1e...Vertical angle of the overhang 4b...Slot for boss 1g...Tension handle part
4c...Slot groove A...Protrusion part
5 ... Link plate 6 ... Link pin 7 ... Stem 1 - Tube body 1e ... Overhanging part apex angle 1a
...Tension boss 1b...Fixing fitting boss A...Protrusion part 1...Tube body le...Protrusion part apex angle 1a...Tension boss 1h...
Tension part outer wall 1b...Boss for fixing fitting 1g.
...Tension handle IC...Inner wall of overhang A.
・Protruding part ld...Bottom of the protruding part Fig. 2 1...Tube body 12...Tightening bolt 1a
・・Tension boss 1b・・Boss for fixing fitting 1d・Protrusion part bottom 111・Protrusion part outer wall 4・Fixing metal fitting 4a・・Round hole 4b・Boss groove 4c・Slot groove Fig. 3 1 ・・・Tube body 1a...Tension boss 1b...Fixing metal boss 1h...Protrusion outer wall 4...Fixing metal fitting 4b...Boss groove 4c...Slot groove 4B Figure 1... Tube body 4.Fixing metal fittings la.
... Tension boss 5 ... Link plate 2 ...
・Lower pressure base 6...Ric pinot 2a・Tension dovetail groove 16...Spring 3...Upper pressure base 2...Lower pressure base 9...Handle 3・
...Upper pressure base 10...Positioning bolt 4
・Fixing hardware 11...Fixing hardware 7...
Stem 13... Valve holding plate 7a...
・Right-hand thread part 14...Mounting bolt 7b...
Left thread part Fig. 5B 1...Tube body 8...Body frame
・2...Lower pressure base 9...Huff dollar 3...Upper pressure base 7...Stem No. 6A Fig. 1...Tube body C...Crack occurrence point Fig. 7 Fig. 8 Fig. 20 ... Tube body 21 ... Filler piece 22 ... Clamping tool 23 ... Clamping tool Fig. 9 1 ... Tube body 24 ... Flange 25 ... Projection

Claims (2)

[Claims] (1) In a pinch valve structure that controls fluid by pinching a part of an elastic or flexible tube body vertically in a direction perpendicular to the flow, a cross section in the perpendicular direction of the part where the tube body is pinched vertically. However, a tapered protrusion A is provided on the inner wall on the horizontal axis passing through the center, and the apex angle 1e is directed outward, and the shape of the protrusion in the flow direction is vertically axially symmetrical. A pinch valve characterized in that both ends are tapered, the inner wall 1C of the developed portion is treated to be in close contact with fluid impermeability, and a fixing fitting 4 is fitted and fixed by crimping. (2) In the cross section in the perpendicular direction of the part to be pressed between the upper and lower sides of the tube body, a thick boss part 1 is placed on the outer wall part on the vertical axis passing through the center
A is fitted into a dovetail groove 2a provided on a press base 2 which vertically presses a, Thick boss part 1b on the left and right
The boss portions are fitted into the slots 4c and grooves 4b of the fixing bracket 4 that moves from side to side. The pinch valve according to claim 1, wherein the pinch valve is actuated.