JP4150741B2 - Yarn and gland packing - Google Patents

Description

  The present invention relates to a yarn and a gland packing, and more particularly, to a braided gland packing, a string-like gasket, a yarn used for a fireproof cloth, and the like, and a gland packing made using the yarn.

  As a conventional technique related to a gland packing used for a shaft seal portion of a fluid device and a yarn (knitting yarn) used for the gland packing, a material using expanded graphite as a base material such as those shown in Patent Document 1 and Patent Document 2 It has been known. In these Patent Documents 1 and 2, a yarn for gland packing is filled with a long expanded graphite sheet in a cylindrical member formed by knitting or assembling a fiber material (knit knitting or braiding). It is disclosed to form. Then, a gland packing is created by twisting or braiding using a plurality of yarns formed as described above (for example, eight striking knitting with eight knitting yarns).

In the prior art using the expanded graphite yarn having such a configuration, the outer periphery of the expanded graphite base material is coated with a reinforcing wire material by knit knitting or the like. Therefore, when manufacturing a gland packing by braiding these yarns, It is intended that the tubular member made of braided reinforcing wire counters the tensile and torsional forces generated in each yarn against this, and that the expanded graphite base material in the tubular member is prevented from breaking. It was done.
JP-A-63-1863 Japanese Patent Publication No. 6-27546

  However, when the gland packing is prepared by braiding using these conventional yarns, there is a problem that the expanded graphite loaded in the cylindrical member of the yarn is cut. That is, when the yarn is bent or twisted so as to be twisted or braided, the expanded graphite sheet in the tubular member cannot be stretched following the bending or twisting and is cut. When the expanded graphite is cut, the amount of expanded graphite at the cut portion is insufficient, and the sealing performance in the case of the gland packing is deteriorated, which is bad.

  The object of the present invention is to twist or braid to produce a gland packing by further improving a yarn formed by filling expanded graphite as a base material into a tubular member formed by knitting or assembling a fiber material. In order to prevent the inconvenience that the expanded graphite is cut at this time, it is to be improved with high flexibility. Another object of the present invention is to obtain a gland packing that is formed by the improved yarn and has excellent sealing performance.

According to the first aspect of the present invention, in the yarn, in the cylindrical member 3 formed by knitting or assembling the fiber material 2, a large number of fibrous expanded graphites 4 are positioned at the ends of the fibrous expanded graphite in the longitudinal direction of the fibrous expanded graphite. The length of the fibrous expanded graphite is set to 1000 mm or less so that the amount of displacement of the end position of the fibrous expanded graphite is 5 to 100 mm. it is characterized in that there.

The invention according to claim 2 is the yarn according to claim 1, wherein the thickness of the fibrous expanded graphite 4 is 0.25 mm to 0.5 mm, and the width of the fibrous expanded graphite 4 is divided by the thickness. The aspect ratio is 1.5 or more and 2 or less .

The invention according to claim 3 is characterized in that, in the gland packing, a plurality of yarns 1 according to any one of claims 1 and 2 are converged and twisted or braided to form a string shape. To do.

According to the first aspect of the present invention, as will be described in detail in the section of the embodiment, the fibrous expanded graphite is laterally shifted by a predetermined amount from each other and filled into the cylindrical member. The ability to follow the bending of the yarn due to sliding between the expanded graphite adjacent to each other, that is, the expansion of the expanded graphite is improved, and the expanded graphite can be bent or twisted so as to be twisted or braided without breaking. Can provide yarn. Further, as described in claim 3 , it is also possible to provide a gland packing with stable performance that maintains good sealing performance. In this case, set shift amount ends of fiber維状expanded graphite (end deviation amount) in the 5 to 100 mm, it is further advantageous if Re set Teisu the length of the fibrous expanded graphite below 1000 mm.

  Hereinafter, embodiments of a yarn according to the present invention and a gland packing using the yarn will be described with reference to the drawings. FIG. 1 is a schematic explanatory diagram showing the production status of a yarn, FIG. 2 is a schematic diagram showing an arrangement state of fibrous expanded graphite in the yarn, and FIG. 3 is a diagram showing a gland packing created using the yarn of FIG. FIG. 4 is an enlarged view showing the cross-sectional dimensions of the fibrous expanded graphite, FIGS. 5 and 6 are diagrams showing relationship data between the aspect ratio and the bending radius of the fibrous expanded graphite, and FIG. 7 is a diagram showing an example of using the gland packing. FIG. 8 shows a data table for the elongation of various yarns.

  As shown in FIG. 1, a yarn (knitting yarn) 1 for gland packing according to the present invention includes a plurality of strip-like fibrous expanded graphite 4 in a tubular member 3 formed by braiding a fiber material 2. The end portion is filled and formed in a state of being displaced by a predetermined amount d in the longitudinal direction of the fibrous expanded graphite. And as for the cross-sectional shape of the fibrous expanded graphite 4, it is desirable that the aspect ratio h which is the value which remove | divided the width | variety by thickness is set to 1-5 (1 <= h <= 5). As shown in FIG. 4, the aspect ratio h is a value (h = w / t) obtained by dividing (dividing) the width w in the cross-sectional dimension of the fibrous expanded graphite 4 by the thickness t. The cross-sectional shape of the fibrous expanded graphite 4 may be a shape other than a rectangle such as an oval or an ellipse.

  For example, as shown in FIG. 1, by inserting the fibrous expanded graphite 4 into the cylindrical member 3 arranged vertically, the end position is shifted up and down by d. As shown in FIG. 2, the yarn 1 is formed in the cylindrical member 3 in a state in which a large number of fibrous expanded graphites 4 are filled in a state in which the positions of the end portions of the cylindrical member 3 are shifted by d. In this case, as shown in FIG. 2, the discontinuities e between the fibrous expanded graphites 4 adjacent in the longitudinal direction of the yarn are displaced from each other by d, and a large number of portions are present at certain locations in the longitudinal direction of the yarn. There is an advantage that the interruptions e are concentrated and the mechanical strength of the yarn 1 at that part is unlikely to occur or does not occur. For the sake of convenience, the discontinuous portion e is exaggerated in FIG.

  5 and 6, the thickness t of the fibrous expanded graphite 4 is 0.25 mm, 0.38 mm and 0.50 mm, and the aspect ratio h is 1.5, 2, 3, 4, 5 Data were obtained by measuring the bendable radius in the horizontal direction for a total of 15 types of samples (yarn 1) of five types. The “bendable radius” in this case is the minimum diameter that can be bent in a normal state in which the fibrous expanded graphite 4 is not cut, cracked, or protrudes from between the exterior fiber materials 2. The fibrous expanded graphite 4 having a thickness t of 0.25 mm is used for a small-diameter gland packing yarn, the 0.38 mm is used for a general-purpose gland packing yarn, and the 0.50 mm is used for a large-diameter gland packing. It is conceivable that the usage pattern is suitable for each yarn.

  Therefore, as can be seen from the table of FIG. 5 and the graph of FIG. 6, when the aspect ratio h of the fibrous expanded graphite 4 is 5 or less, a minimum bending radius value that can be practically used is obtained, and the aspect ratio h is It can be seen that the minimum bend radius becomes extremely small when it becomes 3 or less. Therefore, the aspect ratio h is preferably set within a range of 1.0 to 3.0 (1.0 ≦ h ≦ 3.0). When h is 1, when the thickness is 0.25 mm, the width is also 0.25 mm, which makes it difficult to physically cut. Therefore, the lower limit of the aspect ratio h is 1 from the actual situation of the cutting work. It seems realistic to set to. From the experimental data shown in FIGS. 5 and 5, the yarn 1 having an aspect ratio h in the range of 1.5 to 3.0 is preferable.

  The gland packing 5 shown in FIG. 3 is obtained by converging eight yarns (an example of a plurality of yarns) of the above-described yarn 1 around the core material S (the core material S may be omitted) and twisting or braiding (8 striking angle) Knitting etc.) to form a string-like shape, and by continuously rolling and compressing it, a ring-shaped gland packing G having a rectangular cross section and an overall shape can be obtained. For example, as shown in FIG. 7, the gland packing G is mounted on the packing box 7 in a state where a plurality of gland packings G are arranged in the axial direction of the rotating shaft 6 and is pressed in the axial direction by the packing lid 8 to thereby rotate the rotating shaft. 6 is used so as to seal against the outer peripheral surface 6a.

[Example 1]
The yarn according to Example 1 is created as follows. A rectangular cross-sectional shape having a thickness of 0.38 mm and a width of 1.0 mm is formed in a tubular member 3 formed by braiding (knitting) using an Inconel wire (or stainless steel wire or the like) having a diameter of about 0.1 mm as the fiber material 2. Thus, a large number of fibrous expanded graphites 4 having a length of about 200 mm were filled and filled with their end portions shifted by 20 mm to obtain a yarn 1 having a circular (round) cross-sectional shape. That is, this is an example in which the edge deviation d is set to 20 mm. The aspect ratio h of the fibrous expanded graphite 4 in the first yarn 1 according to Example 1 is h = 1.0 / 0.38≈2.63, and the weight of the first yarn 1 is 5 g / m. there were.

  FIG. 3 shows a gland packing 5 using the yarn 1 of the first embodiment. This gland packing 5 is formed by braiding using eight yarns 1 of Example 1 (8-hitting angle knitting, etc.), applying graphite on the surface, and forming a gland packing 5 having a cross section of 8 mm in length and a square of 8 mm in width. Produced.

[Example 2]
The yarn according to Example 2 is created as follows. The expanded graphite 4 having a cross-sectional size of 0.38 mm, a width of 1.0 mm, and a length of 200 mm is converged into a long product while shifting its end by 30 mm, and the outer periphery thereof has a wire diameter of 0.1 mm. A yarn 1 having a circular (round) cross-sectional shape was produced by covering with a cylindrical member 3 formed by knitting using a fiber material 2 of Inconel wire. In other words, this is an example in which the end deviation d is set to 30 mm. The aspect ratio h of the fibrous expanded graphite 4 in the second yarn 1 according to Example 2 is h = 1.0 / 0.38≈2.63, and the weight of the second yarn 1 is 4 g / m. there were.

  After braiding with eight yarns 1 according to Example 2, the surface was coated with graphite to produce a gland packing 5 having a cross section of 6.5 mm in length and a square of 6.5 mm in width (see FIG. 3). .

  FIG. 8 shows a characteristic comparison table between the yarns of Examples 1 and 2 of the present invention and the conventional products 1 to 5 having the conventional structure. The schematic configuration of the conventional product is as follows. The yarn of the conventional product 1 has a structure in which a plurality of thin expanded graphite sheets are laminated and the outer periphery thereof is reinforced with fibers. The yarn of the conventional product 2 has a structure in which the outer periphery of a string-like body formed by folding a wide expanded graphite tape is reinforced with fibers. The yarn of the conventional product 3 has a structure in which a wide expanded graphite tape reinforced with fibers is folded or twisted. The yarn of the conventional product 4 has a structure in which the outer periphery of the yarn of the conventional product 3 is further reinforced with fibers. The yarn of the conventional product 5 has a structure in which a cylindrical member formed of fibers is filled with a strip-shaped expanded graphite sheet.

  From the characteristic comparison table of FIG. 8, it can be understood that the elongation of the yarn 1 of Examples 1 and 2 is clearly superior to that of any of the conventional products 1 to 5 and has a high level. This significant improvement in elongation eliminates the inconvenience of the fibrous expanded graphite 4 not being able to follow the bending condition when braiding with a plurality of yarns 1 to create a gland packing. Therefore, it is possible to exhibit good sealing performance over a long period of time.

  That is, in the conventional yarn, expanded graphite (expanded graphite sheet, expanded graphite tape) is randomly charged and filled in the cylindrical member, so that there is a break between the expanded graphite adjacent in the longitudinal direction of the yarn. Part (see the discontinuous part e in FIG. 2) is unevenly distributed, and the density at the longitudinal position of the expanded graphite yarn becomes non-uniform, for example, discontinuous parts are concentrated in one place. Easily, and mechanical elongation tends to be non-uniform. Therefore, it is considered that when the yarn is twisted or bent, there is a problem that the expanded graphite is relatively easily cut off at a portion where the elongation is inferior.

  On the other hand, in the yarn 1 according to the present invention, since the fibrous expanded graphite on a large number of strips filled in the cylindrical member 3 is configured to be shifted in the longitudinal direction of the yarn evenly, Thus, the locations of the discontinuous portions e are evenly distributed and arranged in the longitudinal direction as the yarn 1 (also in the lateral direction), and the density of the fibrous expanded graphite 4 in the tubular member 3 is made more uniform. can do. As a result, the response to the expansion of the expanded graphite due to slippage is made uniform and substantially improved regardless of the position in the longitudinal direction of the yarn (see FIG. 8), and the expanded graphite is not cut. The yarn 1 can be twisted and braided.

  From the above, the yarn 1 according to the present invention and the gland packing 5 thereby have the following advantages. 1. A yarn having an arbitrary thickness can be manufactured by changing the number of converged fibrous expanded graphite. 2. The sliding between the fibrous expanded graphite is good, so that the expanded graphite is not cut and the elongation is large. 3. Since the fiber bundle is easily deformed and rounded, the fiber bundle has good adhesion to the reinforcing material and is easy to bend. 4). Since long materials are not used, production is easy. 5. It is possible to make yarn without adhesive.

Action diagram showing how to make an outline of yarn Schematic showing the arrangement of fibrous expanded graphite inside the yarn The perspective view which shows the gland packing by the braiding of the yarn of FIG. Explanatory drawing which shows the cross-sectional shape and dimensional ratio of fibrous expanded graphite The figure which shows the contrast table of the ratio of the width / thickness of the cross section of fibrous expanded graphite and the minimum bending radius The figure which shows the relationship graph of the ratio of the width / thickness of the section of fibrous expanded graphite and the minimum bending radius Sectional view of the main part showing an example of using gland packing The figure which shows the characteristic comparison table regarding the elongation of the conventional product of the yarn and the product of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Yarn 2 Fiber material 3 Tubular member 4 Fibrous expanded graphite 5 Gland packing

Claims (3)

A cylindrical member formed by weaving or assembling a fiber material is filled with a large number of fibrous expanded graphite, with the positions of the ends thereof being shifted by a predetermined amount in the longitudinal direction of the fibrous expanded graphite. The length of the fibrous expanded graphite is set to 1000 mm or less so that the amount of deviation of the end position of the fibrous expanded graphite is 5 to 100 mm . The thickness of the said fibrous expanded graphite is 0.25 mm or more and 0.5 mm or less, and the aspect ratio which is the value which remove | divided the width of the said fibrous expanded graphite by thickness is 1.5 or more and 2 or less . Yarn. Gland packing composed plurality by focusing on twist processing or braided to string-like yarn according to any one of claims 1-2.

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