JPS63308275A - Packing - Google Patents

Abstract

PURPOSE:To remarkably improve the usability and versatility of a worked braid-like packing by filling up strip-like seal materials less than 5mm wide in a cylindrical member formed by a fiber to be used as a knitting yarn and ring-stitching or braiding the knitting yarn. CONSTITUTION:A lot of strip-like seal materials 2 obtained by cutting an expanded graphite sheet about 0.38mm thick to a width of about 5mm and a length of about 25mm are filled in a cylindrical member 1 formed using aramide fiber with a cotton yarn number 40 by knitting, tubular or baglike plain stitching to form a knitting yarn. Whereupon, the compressibility and allowable knot frequency are increased by cutting the above sheet to about 5mm or less, so that the tensile strength and tenacity enough for enabling ring-stitching of braiding can be obtained by the synergism of the strip-like seal materials 2 improved in the tensile strength and tenacity and the cylindrical member 1 formed by aramide fiber, which is filled up with a seal materials and adapted to coat the seal materials. Accordingly, the worked braid-like packing is cut and bent annularly to be used as a ground packing, for example, so that usability and versatility can be remarkably improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a packing suitable as a gland packing used in shaft seals of fluid machines, etc., and requiring high sealing performance.

(Prior Art) Conventionally, packings using expanded graphite or expanded vermiculite as a base material have been manufactured by methods such as a lamination method, a die mold method, a chip mold method, and a ribbon pack method.

(Problem to be solved by the invention) However, according to these methods, it is necessary to form the ring shape in advance according to the shaft diameter to be used, and it cannot be used for other shaft diameters. . Therefore, it lacks versatility, and expanded graphite and expanded vermiculite themselves
Due to its low tensile strength and brittleness, it is difficult to remove it for replacement once it has been installed, resulting in poor usability.

Furthermore, as for the individual problems of each of the above-mentioned methods, in the case of the lamination method, the yield is poor and it leads to an increase in cost. In the case of the die molding method and the chip molding method, molding is required, resulting in high costs and poor versatility.

When using the ribbon pack type, workability may be poor.

These problems can be solved by constructing expanded graphite or expanded vermiculite into a string-like body so that it can be cut into a predetermined length according to the shaft diameter and used, as with other single-fiber braided packings. However, as mentioned above, expanded graphite and expanded vermiculite themselves have low tensile strength and are brittle with a low compressibility and allowable number of twists, so they cannot be braided. Therefore, it has been impossible to use the cut braided packing by cutting it into a predetermined length according to the shaft diameter and then winding the cut braided packing around the outer periphery of the shaft like other braided packing.

The present invention was made in view of the background of the prior art, and in particular, when expanded graphite sheets and expanded vermiculite molded into sheet shapes are cut into widths of 5 mm or less, the compression ratio and allowable number of twists increase dramatically. Focusing on the fact that it has the property of increasing energy consumption, we cut expanded graphite sheets or expanded vermiculite formed into sheets into strips with a width of 5 mm or less and used them as sealing materials (core materials). At the same time,
This strip-shaped sealing material is filled into a cylindrical member formed of fibers, and a packing that can be twisted or braided by the synergistic effect of the cylindrical covering fiber member and the strip-shaped sealing material is provided. The purpose is to improve usability and versatility.

[Means for solving problems]

In order to achieve the above object, the packing according to the present invention has the following features:
A cylindrical member made of fibers is filled with a rectangular sealing material having a width of 5 mm or less to form a knitting yarn, and this knitting yarn is twisted or braided.

[Function] In the present invention, the compression ratio and allowable number of twists are increased by cutting the sealing material to a width of 5 mm or less, thereby improving the tensile strength and toughness, and the strip-shaped sealing material is filled. Due to the synergistic effect with the cylindrical member made of fibers covering the strip-shaped sealing material, tensile strength and toughness sufficient for twisting and braiding can be obtained.

〔Example〕

As shown in FIG. 1, an expanded graphite sheet with a thickness of 0.38 mm is attached to a cylindrical member 1 formed by knitting, tubular weaving, bag knitting, etc. of aramid fiber of cotton count No. 40, and a width of 5fflI11. (preferably width 3m
Rectangular sealing material 2 obtained by cutting m) x length 25+nm
A large number of knitting yarns 3 shown in FIG. 2 are formed by filling a large number of .

Then, the knitting yarn 3 is knitted at 8 perpendicular angles using, for example, 8 pieces to form a string-like body 4 shown in FIG. The braided packing is constructed by impregnating it with a plugging material 5 made of a type adhesive or the like.

In addition, the knitting yarn 3 is bundled, for example, 6 yarns, and 20 times/m
Perform roll forming while applying the twisting process to form the string-like body 4° shown in Fig. 4, and coat the surface of the string-like body 4° with silicone oil. The gasket may be constructed by impregnating it with a plugging material t made of la flake graphite, a rubber adhesive, or the like.

In addition, the string-like body 4 shown in FIG. 3 is formed using the knitting yarn 3 shown in FIG. It is also possible to have a packing structure in which the plugging material 5 is removed by a means and then the surface of the string-like body 4 is impregnated with the plugging material 5.

Fig. 5 shows the experimental results of the relationship between the cutting width and compression ratio of an expanded graphite sheet with a thickness of 0.38 mm, and Fig.
The experimental results of the relationship between the cutting width of an expanded graphite sheet having a thickness of 38 mm and the allowable number of twists are shown.

In these figures, the cutting width of the expanded graphite sheet is 5m+
It can be seen that when the value is n or less, the compression ratio and the allowable number of twists increase dramatically.

Therefore, the knitting yarn 3 in which the cylindrical member 1 is filled with the strip-shaped sealing material 2 made of an expanded graphite sheet with a cutting width of 5 m+n or less
By using this, the string-like bodies 4, 4'' described in the first and second embodiments can be formed easily and reliably. That is,
Even when 8-stroke knitting and twisting are performed, the strip-shaped sealing material 2 serving as the core material does not break, that is, the knitting yarn 3 does not break. Therefore, the string-like body 4,4° can be cut into a predetermined length according to the shaft diameter and used as a gland packing, thereby improving versatility and usability.

The string-shaped body 4.4° thus obtained shows excellent properties when used as a ground packing as it is, but if necessary, it may be exposed on the surface of the string-shaped body 4.4° as described above. By removing the aramid fibers with a burner, the surface is smoothed, and when used as a gland packing, it prevents local contact with the contact area and improves sealing performance.

Further, in the above embodiment, a plurality of knitting yarns 3 are bundled and twisted or braided, but of course, one piece of knitting yarn 3 can be twisted or braided according to the dimensions and configuration of the shaft seal. The ground packing may also be constructed using the following methods.

Furthermore, in the embodiment described above, aramid fibers are used as the fibers 1 covering the strip-shaped sealing material 2; however,
In addition to these fibers, there are also metal fibers such as stainless steel, asbestos, and ceramic fibers.

Inorganic fibers such as glass fiber, cotton, and rayon.

Organic fibers such as phenol, FBI, PTFE, etc. may be used depending on the intended purpose.

The treatment for removing the fibers exposed on the surface of the string-like bodies 4, 4'' formed using these fibers can be selected from burner treatment, chemical treatment, high-temperature water treatment, etc., depending on the material of the fibers. It is something to do.

Further, in addition to the process of removing the covered fibers, for example, a process of partially removing only the shaft sealing surface of the string-like body 4, that is, a part of the exposed fibers may be removed.

Furthermore, in each of the above embodiments, as the strip-shaped sealing material 2,
5mm11! Although the following explanation uses an expanded graphite sheet, expanded vermiculite, which is formed into a sheet by adding a small amount of adhesive, is formed into a strip shape with a width of 5 mm or less,
Even if this is filled as a strip-shaped sealing material 2 into the cylindrical member 1 formed of the fibers, substantially the same effect as in the embodiment described above can be obtained.

(Effects of the Invention) As explained above, according to the present invention, a strip-shaped sealing material whose compression ratio and allowable number of twists are increased by cutting it into a width of 5 mm or less is placed inside a cylindrical member formed of fibers. The tensile strength and toughness of the knitting yarn are greatly improved because the knitting yarn is formed by filling the knitting yarn with

For this purpose, this knitting yarn can be braided or twisted, and the braided or twisted string-like packing is cut to a predetermined length according to the shaft diameter.
This cut packing can be bent into an annular shape and used, for example, as a ground packing, greatly improving usability and versatility.

In addition, since it is easy to fill the cylindrical member with the strip-shaped sealing material, there are advantages such as good workability in forming the knitting yarn.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram showing the manufacturing state of the knitting yarn according to the present invention, FIG. 2 is a partially cutaway perspective view showing an example of the knitting yarn manufactured according to FIG. 1, and FIG. 3 is an 8-stroke FIG. 4 is a partially cutaway perspective view showing an example of a twisted string-like body; FIG. 5 is a partially cut-away perspective view showing an example of a twisted string-like body; FIG. FIG. 6 is a graph showing the relationship between the cutting width of the expanded graphite sheet and the compression ratio. 1... Cylindrical member 2... Strip-shaped sealing material 3... Knitting yarn Patent applicant Representative of Nippon Virae Gyo Co., Ltd. Patent attorney Takashi Suzue - Figure 4 A' Figure 5 is cut with a sword (mm) [Sword 1 meter (mm)

Claims (3)

[Claims] (1) A packing characterized in that a cylindrical member formed of fibers is filled with a strip-shaped sealing material having a width of 5 mm or less to form a knitted yarn, and the knitted yarn is twisted or braided. (2) The packing according to claim 1, wherein the strip-shaped sealing material is expanded graphite pressure-formed to a density of 0.5 g/cm^2 or more. (3) The packing according to claim 1, wherein the strip-shaped sealing material is expanded vermiculite that is pressure-formed to a density of 0.5 g/cm^2 or more.