JPH0816511B2 - Packing and its manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gland packing suitable for sealing a shaft of a fluid device such as a valve or a pump, and more particularly to a packing formed using a flexible expanded graphite sheet and a method of manufacturing the same. Regarding improvement.

[0002]

2. Description of the Related Art Conventionally, as a packing using a flexible expanded graphite sheet having good bearing properties and self-lubricating properties, Japanese Patent Application Laid-Open No. 4-25671 discloses a packing of expanded graphite tape in the longitudinal direction. Folding is performed on at least one of the folds to form a cord of a folded layer, and the outer periphery of the cord is covered with a braid made of a reinforcing thread such as a stainless steel wire, an inconel wire, a carbon fiber, and an aramid fiber. A gland packing has been proposed in which a plurality of knitting yarns are bundled and braided or twisted to form a knitting yarn.

[0003]

According to the structure of the gland packing, since the fold layer obtained by folding the expanded graphite tape is used as a string, a knitting yarn which does not slip between the fold layers can be obtained. The first feature is that the expanded graphite tape is not cut during braiding for manufacturing the gland packing, so that the braiding becomes easy and a gland packing having a high sealing function can be obtained.

In addition, since the string is reinforced by the braid of the reinforcing yarn, the integral bonding force between the string and the reinforcing braid is increased, and the string and the reinforcing braid are separated from each other. The second feature is that the shape can be suppressed, the shape retention of the knitting yarn can be improved, and also from this point, the braiding can be facilitated and the sealing function of the gland packing can be improved.

However, the gland packing having the above structure is
Since the entire fold layer obtained by folding the expanded graphite tape is covered with a reinforcing braid to form a knitting yarn, the integral bonding of the expanded graphite and the reinforcing braid is not sufficient, and the cushion can be obtained by reliably integrating the both. Does not exhibit the maximum performance, compression recovery rate and stress relaxation resistance.

[0006]

The object of the present invention is to obtain a knitting yarn in which the expanded graphite tape and the reinforcing braid are further integrally bonded.
An object of the present invention is to provide a packing capable of maximizing cushioning property, compression recovery rate and stress relaxation resistance, and a method of manufacturing the packing.

[0007]

In a packing according to the first invention of the present application, a flexible expanded graphite tape having a rectangular cross section is covered with a reinforcing knitted bag body made of a fiber material, and the knitted bag body containing the graphite tape is Stretching or drawing in the longitudinal direction to make a cross section of a substantially round shape or a square shape as a knitting thread, and a plurality of these knitting threads are braided or twisted into a string without a core or with a core. That is the summary. A method for manufacturing a packing according to the second invention of the present application comprises a step of knitting a flexible expansive graphite tape having a rectangular cross-section with a fiber material in a bag shape to form a knitted bag body, and a knitted bag body containing the graphite tape. Stretching or drawing in the longitudinal direction to form a knitting yarn having a substantially round or square cross section, and braiding or twisting a plurality of the knitting yarns without a core or with a core in a string shape. The gist is that it consists of a processing step.

[0008]

The knitting yarn having the above-mentioned structure is obtained by coating a flexible expanded graphite tape having a rectangular cross section with a reinforcing knitted bag body from a fiber material,
Since the knitting yarn is forcibly stretched or drawn in the longitudinal direction, the obtained knitting yarn has a structure in which the graphite tape and the knitting bag body are firmly integrated with each other by the above-mentioned processing. As a result, it is possible to increase the cushioning property, compression recovery rate, and stress relaxation resistance of the packing braided or twisted using the knitting yarn.

[0009]

1 (a), 1 (b) and 1 (c) show a manufacturing process of a braided packing according to an embodiment of the present invention.

FIG. 1 (a) A flexible graphite tape 1 having a width of 6.0 mm and a thickness of 1.4 mm was coated with a knitting bag body 2 of SUS316 metal wire having a wire diameter of 0.1 mm by a bag knitting machine. A knitted bag containing graphite tape
Shown with ₁ .

FIG. 1 (b) The knitting bag A ₁ containing the graphite tape was stretched in its longitudinal direction by a tensioning machine to obtain a knitting yarn A ₂ . By this drawing process, the graphite tape having a rectangular cross section was deformed together with the knitted bag body into a substantially round cross section, and at the same time, the graphite was slightly projected from the stitch, and the round graphite and the knitted bag body were integrally bonded.

FIG. 1 (c) Next, 8 pieces of the above-mentioned knitting yarn A ₂ , the number of gears is 30 upper and 4 lower.
0, 640 g of weights are knitted at 8 shots, 16 of these 8 shots are knitted at 40, 70 below the number of gears, and 16 shots are knitted at 600 g of weights. : Immersed in a mixed solution of graphite: toluene = 6: 94: 150 for several seconds and air-dried for 24 hours to evaporate the solvent,
The cord-like braid was rolled on four points to obtain a cord-like gland packing 3 having a square cross section with a length of 9.5 mm, a width of 9.5 mm and a density of 1.3 g / cm ³ .

FIG. 2 shows a cord-shaped gland packing 5 in which the core 4 is covered with the knitting yarn A ₂ in a bag knitting manner. The core 4 is
Flexible graphite by weight: graphite: rubber: toluene = 70: 2
The kneaded material of 0:10:19 was extruded to have a diameter of 7.4.
It is molded into a round bar of mm, air-dried, and has a thickness of 7.3 mm and a density of 0.
A 7 g / cm ³ bar was used. The outer circumference of this rod-like material is 16 round knitted up to 16 knitting yarns of FIG. 1 (b), the number of gears is 40, the lower 40, and the weight is 450 g.
Immersed in a mixed solution of rubber: graphite: toluene = 6: 94: 150 for several seconds, air-dried, and stripped the solvent. .5m
This is a gland packing having a square cross section with a m of 1.1 g / cm ³ and a density of 1.1 g.

3 (a), (b), (c) and (d),
7 shows a manufacturing process of a braided packing according to another embodiment of the present invention.

FIG. 3 (a) A flexible graphite tape 6 having a width of 5.5 mm and a thickness of 1.5 mm was covered with a knitting bag body 7 of SUS316 metal wire having a wire diameter of 0.1 mm by a bag knitting machine. A knitted bag containing graphite tape
Shown by ₃ .

FIG. 3 (b) The knitted bag body A ₃ containing the graphite tape is drawn by a four-point roll machine 8, and the graphite tape having a rectangular cross section is deformed into a substantially square shape together with the knitted bag body, and at the same time, the graphite is stitched. The square graphite and the knitted bag body were integrally bonded to each other.

FIG. 3 (c) Knitting yarn A ₄ was obtained by the drawing process.

FIG. 3 (d) Next, the eight knitting yarns A ₄ are provided, and the number of gears is 30 upper and 4 lower.
0, 640 g of weights are knitted at 8 shots, 16 of these 8 shots are knitted at 40, 70 below the number of gears, and 16 shots are knitted at 600 g of weights. : Immersed in a mixed solution of graphite: toluene = 6: 94: 150 for several seconds and air-dried for 24 hours to evaporate the solvent,
The cord-like braid was rolled on four points to obtain a cord-like gland packing 9 having a square cross section with a length of 9.5 mm, a width of 9.5 mm and a density of 1.3 g / cm ³ .

FIG. 4 shows a string-like gland packing 11 in which the core 10 is covered with the knitting yarn A ₄ in a bag knitting manner. Core 1
0 is by weight flexible graphite: graphite: rubber: toluene = 7
A kneaded product of 0: 20: 10: 19 was extruded to form a round bar having a diameter of 7.4 mm, air-dried to use a bar having a thickness of 7.3 mm and a density of 0.7 g / cm ³ . The outer circumference of this rod-like object is 16 knitting yarns of FIG.
It was obtained by 16-round circular knitting up to 0, 450 g of weight, dipping this circular knitted body in a weight% of a mixed solution of rubber: graphite: toluene = 6: 94: 150 for several seconds, and air-drying to volatilize the solvent. The cord-like body is rolled on four points to form a gland packing having a square cross section with a length of 9.5 mm, a width of 9.5 mm, and a density of 1.1 g / cm ³ .

[0020]

As described above, according to the present invention,
The flexible expanded graphite tape having a rectangular cross section is covered with a reinforcing knitting bag made of a fibrous material, and then forcibly stretched or drawn in the longitudinal direction is used for the knitting yarn. The graphite tape and the knitted bag body are integrally combined by the above-mentioned processing, which is rich in elasticity,
And since it is a uniform thin knitting yarn, the packing obtained by braiding or twisting with this knitting yarn has an increased cushioning property, a large compression recovery rate, and an increased stress relaxation resistance performance, and maintenance. The number of times is reduced and excellent effects are exhibited.

Further, according to the packing manufacturing method of the present invention,
The process of covering the flexible expanded graphite tape with the reinforcing knitted bag and the process of stretching or drawing it are simple and easy operations, respectively, and can be performed continuously, improving the packing manufacturing workability. In addition, manufacturing cost can be reduced.

[Brief description of drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a packing manufacturing process diagram showing one embodiment of the present invention, wherein (a) is a perspective view of a knitted bag body containing graphite tape,
(B) is a perspective view of a knitting yarn obtained by drawing, (c)
[FIG. 3] is a perspective view of a gland packing formed by braiding with the knitting yarn.

FIG. 2 is a perspective view of a gland packing showing another embodiment of the present invention.

FIG. 3 is a packing manufacturing process diagram showing another embodiment of the present invention, in which (a) is a perspective view of a knitted bag body containing a graphite tape;
(B) is an explanatory view of a drawing state, (c) is a perspective view of a knitting yarn obtained by drawing, and (d) is a perspective view of a gland packing braided with the knitting yarn.

FIG. 4 is a perspective view of a gland packing showing another embodiment of the present invention.

[Explanation of symbols]

A ₁ Knitted bag containing graphite tape 1 Flexible expanded graphite tape 2 Reinforced knitted bag made of fiber material A ₂ Knitting yarn 3, 5 Braided packing 4 Core A ₃ Knitted bag containing graphite tape 6 Flexible expanded graphite Tape 7 Reinforced knitting bag made of fiber material A ₄ Knitting yarn 8 Drawing machine 9, 11 Braided packing 10 Core

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-25671 (JP, A) JP-A-4-245960 (JP, A) JP-A-4-245942 (JP, A) JP-A-3- 172382 (JP, A) JP 63-1863 (JP, A) JP 63-308275 (JP, A) JP 5-106741 (JP, A) Actual flat 4-48463 (JP, U)

Claims (2)

[Claims] 1. A flexible expanded graphite tape having a rectangular cross section is covered with a reinforcing knitted bag body made of a fibrous material, and the knitted bag body containing the graphite tape is stretched or drawn in its longitudinal direction to have a substantially circular cross section. Alternatively, a packing having a substantially square cross section as a knitting yarn, and a plurality of these knitting yarns are braided or twisted into a cord shape without a core or with a core. 2. A step of weaving a flexible expansive graphite tape having a rectangular cross section into a bag shape by knitting and covering it with a fiber material to form a knitted bag body, and stretching or drawing the knitted bag body containing the graphite tape in the longitudinal direction thereof. And a step of braiding or twisting the knitting yarn into a knitting yarn having a substantially round cross section or a substantially square cross section and a plurality of the knitting yarns without a core or with a core. Characteristic packing manufacturing method.