JPS59106765A - Shaft sealing mechanism of center type butterfly valve and method of producing same - Google Patents

Abstract

PURPOSE:To omit an O-ring attaching process while preventing a valve stem from displacement when it is inserted into a through hole of a seat ring, by securing fixedly a sealing rubber material to a seal case. CONSTITUTION:A shallow pan-like seal case 7 is provided on the bottom surface with a hole 8 through which a valve stem is inserted, and around which a proper number of notches 8a having a proper shape are provided. An annular concave groove 9a is provided on the periphery of a portion 9 corresponding to through holes of metal molds M1, M2 and the seal case, and in the position corresponding to the annular groove is disposed the seal case 7 having the whole surface applied by adhesives so that rubber is poured in a cavity within the metal molds. The rubber 3a filled in the molds is filled also in a seal ring 7 through notches 8a of the seal ring 7 and further forms an annular portion projecting radially of the valve stem penetrated hole along the concave groove 9a provided in the metal mold so that an O-ring is not particularly needed to be placed in the assemblage and the valve can be assembled as it is for sufficiently displaying the shat sealing function.

Description

[Detailed Description of the Invention] (a) Purpose of the Invention This invention provides an elastic seat ring stretched on the inner surface of the valve body,
In a central butterfly valve having a structure in which a valve stem pivotally connected to a valve body passes through the note ring, an O-ring disposed in an O-ring case is attached to a seat ring material closely surrounding the valve stem. - This invention relates to an improvement in a butterfly-shaped valve 7-ring mechanism that includes a ring to form a seal in the axial direction of the valve shaft, and a method for manufacturing the same.

The shaft sealing device for a butterfly valve having the above-mentioned structure is, for example, a system having the structure as schematically shown in FIG. , an elastic foot ring 3 is stretched on the inner peripheral surface of the annular valve body 1,
A valve plate 2 fixed to a valve shaft 4 pivotally connected to the valve body is disposed inside the valve body, and the valve plate 2 is fixed to a valve shaft 4 which is pivotally connected to the valve body.
The circumferential surface of the sorting ring presses against the inner circumferential surface of the sorting ring to perform a sealing action, and the valve shaft 4, which passes through the seat ring and reaches the valve body, is provided with an internal seal at an appropriate position where it is in close contact with the seat ring. A sealing member 5, which houses an O-ring 5b and is made of O-ring case 5a having a substantially U-shaped radial cross section and made of metal, hard plastic, etc., is disposed. - Conventionally, there have been widely used devices in which a ring is pressed against the circumference of the valve shaft to prevent leakage in the longitudinal direction of the valve shaft.

The stem sealing mechanism for a butterfly valve as described above is made by placing an O-IJ song goose in the partial mold corresponding to the valve stem through hole when injecting rubber, which is a note ring material, into a mold. Adhesive 6'f is applied to the outside of the O-ring case where the case contacts the note ring material in order to form a sufficient bond.
The adhesive is applied to the mold and attached to the mold (see Figure 2), but since it is inconvenient for this adhesive to adhere to the surface on the inside of the case where the O-ring will sit in the future, the case is immersed in the adhesive (see Figure 2). It was impossible to apply adhesive to each piece by dipping, so each piece had to be done by hand.

Furthermore, when rubber is injected after installing such a case ff:m, there is a slight gap between the inner open edge of the case and the mold periphery, while the rubber is injected. Since the pressure is as high as approximately 150 kg/7, it is impossible to prevent the rubber material from entering the inner space of the case through the above-mentioned gap. In addition, this rubber that has entered is not one that has flowed in smoothly, but one that has entered by force due to strong pressure, so it contains a lot of air bubbles, which is really inconvenient for the sole to function, so after molding the note ring, The rubber material in this area still needs to be scraped off by hand.

As outlined above, the shaft sealing mechanism as described above.

Although the structure itself is simple and the sealing effect is sufficiently ensured, the manufacturing process requires manual labor, and it is almost always necessary to discard a portion of the tring material. These were unable to avoid the inherent drawback of increased costs.

The present invention has been made in view of the current situation, and uses a shallow dish-shaped O-ring case molded to match the commercially available O-ring groove, and a sheet. When molding the ring, the rubber material is actively guided into the space inside the case, and the inflowing rubber material is molded so as to protrude radially inward, thereby creating a shaft sole, which is used when assembling the valve. It can be used as a shaft sealing mechanism without having to reinstall the O-ring, and when the rubber material on the sole wears out, the O-ring can be used as is.
It is also possible to scrape out the note ring material (rubber material) inside the ring case and reinstall a commercially available 0-ring for use, and it is possible to automatically manufacture a sort ring with a case. The object of the present invention is to provide a method for manufacturing a shaft sealing mechanism for a butterfly valve, and the shaft sealing mechanism. Since this O-ring case opens upward, it is easy to scrape out the sheet ring material adhered inside the case.

(B) Structure of the Invention An embodiment of the present invention will be described with reference to the attached drawings. In the present invention, a shallow dish-shaped sole case 7 as shown in FIG. 4 is used.

There is also a hole 8 on the bottom of the sole case through which the valve stem will be inserted when assembling the seat ring into the valve.
A suitable number of notches of an appropriate shape are formed on the periphery of the mold, and when rubber is injected into the mold, the rubber is actively encouraged to flow into the sole kusuf through these notches. . In the illustrated embodiment, the triangular notch 8a has three
It is a profit.

Fig. 3 is a cross-sectional view of the main part showing the process of molding a tether ring using such a solekoosuf, and is designated by the symbol M.
, , M2 indicates a mold, and numeral 9 indicates a part of the mold that is to form a through hole for forming a hole through which the valve stem passes through the Zot ring. In the present invention, an annular groove 9a is provided on the periphery of the through-hole corresponding portion 9 of such a mold corresponding to the 7-le case, and a 7-hole groove 9a is provided at a position opposite to this.
Rubber is injected into the cavity inside the mold with the case 7 placed in place. In this case, two adhesive layers are attached to the entire surface of the seal case 7.

Therefore, there is no need to apply adhesive only to the outer surface of each O-ring case, as is the case with the well-known O-ring case described above, and it is only necessary to immerse the entire O-ring case 7 in the adhesive.

/- When the rubber is press-fitted after the rubber case 7 is mounted at the predetermined position of the mold, the rubber filled in the mold passes through the notch 8a'z of the sole ring 7 and also fills the seal ring.

The seat ring 3 molded in this way is the sole ring 7.
The inside of the valve shaft through hole is filled with the rubber material 3a, and the mold is also formed with an annular portion that protrudes inward in the radial direction of the valve shaft through hole along the five-digit groove 9a. There is no need to further fill an O-ring during assembly, and the valve can be assembled as is. sole ring 7
As mentioned above, since the adhesive is present on the inside of the sole ring, the internal rubber material 3a also firmly adheres to the sole ring and does not displace unduly, allowing the shaft sealing function to be fully maintained. I will do it.

In the case shown in Figure 3, the sole case 7 is placed on the outermost side of the sorting ring, making the pool case shaped like a shallow dish, but it is of course possible to place it in the position shown in Figure 1. It is. However, when the configuration is as shown in Figure 3,
When the internal rubber material 3a becomes worn or damaged, it can be scraped out and reused by installing an O-ring again, thereby increasing the durability of the sorting ring.

(J Effects of the Invention Since the present invention has the above-described configuration, it is possible to apply adhesive over the entire surface of the seal case when molding the seat ring, so it is possible to perform so-called "jap pickling" using a machine. The work time can be reduced compared to manually applying only to the outside of the O-ring case, and it is also possible to remove the sheet ring material (rubber material) that has entered the O-ring case one by one, as in the case of the known O-ring case. Since there is no need to remove it, it greatly contributes to cost reduction and resource conservation.

In addition, in the known method, after manufacturing the seat ring, the O-ring is installed in the O-ring case in a free state and then the valve stem is inserted, so the O-! It is not easy to arrange and seat the seal in the case so that it can function well, and it is not possible to see it directly. Since the rubber material 3a is fixed to the case, the O-ring installation process can be omitted, and the valve stem is also displaced to 9 when the valve stem is forcibly inserted into the seat ring through hole. Since there is nothing to do, the sealing function can be improved.

[Brief explanation of drawings]

Fig. 1 is a sectional view of the main part showing the configuration of a known shaft sealing mechanism, Fig. 2 is a perspective view of the same O-ring case as above, and Fig. 3 is a sectional view of the main part showing the IJ song forming means according to the present invention. "Figure 4 is a slope view of the sole case. 1... Valve body, 2... Valve plate, 3... Note ring,
5. Null i structure, 6... Adhesive, 7... Knoll case, 8... Valve shaft through hole, 9... Mold. Applicant Tomoe Giken Shisho Co., Ltd., 7σ-1, Agent Patent Attorney Akira Irie, ), No

Claims (1)

[Scope of Claims] ■ Each outer end edge of the valve stem through-hole of a sorting ring made of an elastic material stretched over the inner peripheral surface of the annular valve body and provided with valve stem through-holes at the same position in the diametrical direction. The sole case is made of a rigid material and has an outwardly-opening plate shape on its periphery, and has an introduction opening for guiding the seat ring material into the sole case.The dimensions are such that the sole case is fitted into the groove dimensions of a commercially available O-ring. Then, adhesive is applied to the entire surface of the case to bond the seat ring material to the outer surface of the case, and the inner surface of the case is filled with a foot ring material that is inwardly convex and communicates with the seat ring material on the outer surface. At the same time, the shaft sealing device of the central type valve is fixed with adhesive on the inner surface of the case. 2 Apply adhesive to the entire surface of a seal case with a notch for guiding the sorting material around the periphery of the valve stem through hole, and insert this seal case into the valve stem through hole forming part of the mold for molding the seat ring. The footring material is placed facing the annular groove and injected into the mold to form a seat ring, and the footring material is also filled into the sole case through the guiding notch, and the filled sorting ring A method for manufacturing a shaft sealing mechanism for a butterfly valve, in which a material also enters the annular groove to form an inward protrusion that presses against the valve shaft.