JPS5936147B2 - Manufacturing method for molded packing that is easy to take out - Google Patents

Description

Detailed Description of the Invention (a) Technical Field of the Invention The present invention relates to a packing (so-called gland packing) that is incorporated in a shaft sealing part (grand part) of a fluid device for nuclear power or general industrial use, and seals various fluids. ), and particularly relates to a method of manufacturing a molded packing that is a non-braided type that can be easily removed from a shaft seal.

(b) Background of the Invention Conventionally, gaskets made only of expanded graphite, known as Graphoil (trade name of Union Carbide Company, USA), etc., have been known, and are used for general industrial use in fluid equipment such as valves and pumps. A plurality of them are installed in the shaft sealing part, that is, the chamber (ground part) formed by the shaft and the equipment casing, to prevent fluid from leaking outside the machine.

Packing made only of expanded graphite is made by winding a long expanded graphite sheet into a spiral shape several times and placing it in a mold.
It can be easily obtained by compression molding using a press, and due to the flexibility of expanded graphite and the inherent properties of graphite, it is relatively hard as a so-called ground packing.

However, on the other hand, expanded graphite sheets have extremely weak tensile strength and bending strength, and can be easily torn or broken by the force of human hands. When loading the molded gasket into the shaft seal of a fluid device, it not only needs to be handled with care as it may collapse, but in particular - after being used, the molded gasket must not be removed from the shaft seal. When pulling it out, it was a very difficult task.

Therefore, the emergence of a molded packing that can be easily removed from the shaft seal of a fluid device and a simple manufacturing method are desired. As for gaskets as static packing, there is a gasket as a molded product made by using a net-like structure such as a wire mesh as a core material, overlapping it with a shielding body, and rolling and compressing it, as seen in Japanese Utility Model Application Publication No. 53-7556. .

It is conceivable that such a gasket could be used in combination with an expanded graphite sheet as a molded gasket that can be easily taken out, but in the manufacturing method, even if the network structure and expanded graphite sheet are first placed in a mold, Second, even if compression molding is performed in such a state, not only will the mesh structure and the expanded graphite sheet be misaligned, but the crimping caused by compression molding will not be possible. There were drawbacks such as extremely non-uniform conditions.

Furthermore, it is possible to solve the above-mentioned drawbacks [1] and 2) by bonding the long expanded graphite sheet and the network structure in advance with an adhesive, but in the production process, it is difficult to apply the adhesive. The production method, such as the manufacturing process, bonding process, and drying process, was complicated, and the resulting molded packing had the disadvantage that the original properties of expanded graphite were hindered by the adhesive.

Therefore, there has been no method of manufacturing a molded packing that can be easily taken out as a gland packing, which solves the above-mentioned drawbacks in a simple manner, and which does not impair the original characteristics of the obtained molded packing.

('→Purpose of the Invention Therefore, the present invention relates to a method for manufacturing a molded packing that can be easily taken out from a shaft sealing part of a fluid device as a gland packing, and solves the first and second drawbacks mentioned above. The purpose of the present invention is to provide a method for producing a molded packing, which can be produced without complicated steps, and in which the obtained product does not lose its original properties.

(Summary of the invention) In other words, this invention overlaps a network structure on one side of an expanded graphite sheet, compresses it with a roll, embeds the network structure in the expanded graphite sheet I, pressure-bonds it, and integrates it in advance. The most important part is that a long composite sheet is continuously formed, and the method is characterized by a method for producing a molded packing that can be easily taken out by compression molding using a desired amount of the composite sheet.

(B) Effects of the invention According to this invention, since the network structure is formed into an integrated composite sheet in which the expanded graphite sheet is embedded, the network structure and the expanded graphite sheet cannot be separated even when placed in a compression molding mold. It is impossible for separation to occur.

Furthermore, even when compression molding is performed next, no misalignment occurs between the network structure and the expanded graphite sheet.

Since the net-like structure and the expanded graphite sheet are pressed twice in advance by being embedded and pressed with a roll and then also pressed during post-compression formation, the pressed state becomes uniform and strong.

Furthermore, as for the manufacturing process, compared to the conventional manufacturing method, only the step of passing it through a compression roll is added, so although it is an extremely simple means, the effects achieved by this invention are not practical as described above. It's big.

And according to this invention, network structure and expanded graphite sheet)
- Since no misalignment occurs at all, the product defect rate can be reduced, and it has become possible to switch from manual filling to automated mechanization for filling molds, greatly increasing production efficiency.

In addition, the molded packing manufactured by this invention not only has the ability to easily take out from the shaft sealing section but also has a ℃5 function (it has all the advantages of the conventional gland packing made only of expanded graphite). I was able to provide it.

Therefore, although the manufacturing method according to the present invention is simple in terms of its construction, it is actually useful and has significant effects.

(Example of the Invention) An example of the invention will be described in detail based on illustrative drawings.

FIG. 1 is an explanatory view of manufacturing a composite sheet I, which is the basis of the method for manufacturing a molded packing according to the present invention.

In FIG. 1, 1 is an expanded graphite sheet, 2 is a network structure, and 3 and 3' are rolls of a rolling machine.

The expanded graphite sheet 1 and the network structure 2 are separately supplied to a roll machine, and the network structure 2 is inserted into one side of the expanded graphite sheet 1 by passing it through rolls 3 and 3'. It is possible to continuously form a long composite sheet 4 which is crimped and integrated thereby.

Then, as shown in Fig. 2, this composite sheet is cut to a desired length, that is, the desired amount is wound into a spiral shape.
By compression molding this, a molded packing A as a gland packing as shown in FIG. 3 can be manufactured.

In addition, in this case, the long composite sheet 4 is previously rolled on the roll 3,
3', the network structure 2 is embedded in the expanded graphite sheet 1 and integrated by pressure bonding, making it easier to manufacture the molded packing A, enabling automation through mechanization, and reducing the defective rate. This increases production efficiency.

In addition, the manufactured molded packing A was produced by expanding graphite sheet 1 twice, at the stage of composite sheet I and at the stage of compression molding.
Since the -1 and the network structure 2 are crimped together, they are difficult to separate, resulting in a molded packing that is uniformly integrated and does not easily collapse.

The molded packing A produced in this manner is used as shown in FIG.

In other words, FIG. 4 is a schematic cross-sectional view showing the shaft sealing portion of the fluid equipment, and the shaft sealing chamber (formed by the shaft 5 and the equipment casing 6).
A plurality of molded gaskets A are loaded in the gland chamber.

When the fluid is sealed, the molded gaskets A, A...
is tightened and held.

When it is desired to take out the molded packings A, A, etc. from the shaft sealing chamber, after removing the packing presser plate 7,
This is done using a suitable packing removal tool such as a packing screw 8.

In this case, the molded packing A has the above-mentioned network structure 2 firmly bonded to the expanded graphite sheet 1 and interposed therein in a layered manner, so that the molded packing A itself can be smoothly taken out from the shaft sealing chamber. A molded packing A that can be manufactured can be manufactured.

By the way, as the composite sheet 4, the mesh structure 2 embedded in the expanded graphite sheet +-1 is made of a knitted wire mesh made of fine stainless steel wire in the embodiment, but other materials such as copper, aluminum, etc. may be used.

Further, the network structure may be a strong organic fiber cloth such as phenol resin fiber or an inorganic fiber cloth such as carbon fiber.

Furthermore, in this invention, by making (1) of the network structure narrower than the width of the expanded graphite sheet, the network structure can be prevented from being exposed on the surface of the molded packing, which can be easily taken out as a gland packing. This is necessary and can be easily adjusted at the manufacturing stage of the composite sheet.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of manufacturing the composite sheet that is the basis of the present invention, FIG. 2 is a perspective view of the composite sheet manufactured in FIG. FIG. 4 is a perspective view showing an embodiment of the molded packing obtained by the above process, and FIG. 4 is a sectional view showing a shaft sealing portion of a fluid device. 1... Expanded graphite sheet, 2... Network structure, 4... Composite sheet, 8... Patkin screw, A... Molding Harakin.

Claims (1)

[Claims] 1. In a method for manufacturing a molded packing that can be easily removed from the shaft seal of a fluid device, a network structure is layered on one side of an expanded graphite sheet and compressed with a roll to embed the network structure in the expanded graphite sheet. Taking out as a ground packing characterized by continuously forming a long composite sheet that is crimped and integrated in advance, continuously forming this composite sheet, and compression molding using a desired amount of this composite sheet. Easy method for manufacturing molded packing.