JP2005291260A - Expanding graphite yarn, and gland packing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an expanding graphite yarn having sufficient resistance for external reinforcement against tensile force and torsion to be generated in each of yarns when manufacturing a gland packing, and capable of improving productivity, adaptability and sealability. <P>SOLUTION: A reinforcing wire material 3 having 0.05-0.2 mm of wire diameter is wound around the outer surface of an expanding graphite base material 2, which is formed by twisting an expanding graphite tape, so that the reinforcing wire material 3 is embedded inside along an expanding graphite tape edge 4 spirally exposed in the outer surface of the expanding graphite base material 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an expanded graphite knitting yarn and a gland packing suitable for a gland packing used for a shaft seal portion of a fluid device.

  Conventionally, as expanded graphite knitting yarn, a plurality of expanded graphite tapes of a predetermined width are stacked to form an expanded graphite base material, and the outer periphery of the expanded graphite base material is knitted or bag knitted with a reinforcing wire such as stainless steel wire. And what was reinforced outside is proposed (for example, refer to patent documents 1).

  According to the expanded graphite knitting yarn having the above-described configuration, since the outer periphery of the expanded graphite base material is covered with a reinforcing wire such as a stainless steel wire by knitting or the like, the plurality of knitting yarns are braided to form a gland packing. The knit knitting of the reinforcing wire sufficiently counters the tensile force and twisting force generated in each knitting yarn during manufacturing, and the expanded graphite base material in the knit knitting is prevented from breaking. is there.

JP-A-6-17937

  However, in the above expanded graphite knitting yarn in which the outer surface of the expanded graphite base material is coated by knitting or bag knitting with a reinforcing wire such as stainless steel wire, the expanded graphite base material is knitted or bag knitted with the reinforcing wire. However, there was a problem that it took a lot of time and productivity was poor.

  In addition, since the outer surface of the expanded graphite base material is often covered with a reinforcing wire such as a stainless steel wire that is knitted or bag knitted, such a knitting yarn has characteristics of the expanded graphite base material such as a rotating shaft and a stem. There has been a problem that the conformability and sealability to the equal mating member (hereinafter simply referred to as “mating member”) cannot be exhibited sufficiently. That is, as shown in FIG. 10, in the knitting yarn 1 in which the outer surface of the expanded graphite base material 2 is knit knitted or bag knitted with the reinforcing wire 3, as shown in FIG. A gland packing G is formed by twisting, and the knitting yarn 1 of the gland packing G is compressed from the direction C in FIG. 10 by inserting the gland packing G into the packing box A and pressing it with the packing presser B. Sometimes, the expanded graphite base material 2 has a small amount of bulge that tends to bulge outwardly between the adjacent reinforcing wires 3 and 3 on the outer surface thereof as indicated by a broken line e. The contact with the contact pressure and the contact area becomes insufficient, and the conformability to the mating member 9 and the sealing performance are deteriorated.

The present invention has been made in order to solve such problems, and the object of the present invention is to provide external reinforcement against the tensile force and twisting force generated in each knitting yarn when manufacturing a gland packing. An object of the present invention is to provide an expanded graphite knitting yarn capable of improving productivity and improving conformability to a mating member and sealability, while having a sufficient sufficient resistance.
Another object of the present invention is to provide a gland packing that can improve the conformability to the mating member and the sealing performance while using an externally reinforcing knitting yarn.

  In order to achieve the above object, in the expanded graphite knitting yarn of the invention according to claim 1 of the present invention, a thin reinforcing wire having a wire diameter of 0.05 mm to 0.2 mm is a longitudinal length on the outer surface side of the expanded graphite substrate. It is characterized by being embedded in a spiral shape in the direction. In this case, as the reinforcing wire, organic wire such as rayon, phenol, aramid, PBI, PBO, PTFE, PPS, and PEEK, inorganic wire such as glass fiber, carbon fiber, ceramic fiber, mineral fiber wire, Various wire rods such as stainless steel, Inconel, Monel, etc. can be selectively used according to the application.

  The expanded graphite knitting yarn of the invention according to claim 2 is the expanded graphite knitting yarn according to claim 1, wherein the expanded graphite base material is formed of an expanded graphite tape twisted, and the reinforcing wire is It is characterized in that it is embedded inside the expanded graphite tape edge along the expanded graphite tape edge exposed spirally on the outer surface of the twisted expanded graphite substrate.

  The expanded graphite knitting yarn of the invention according to claim 3 is the expanded graphite knitting yarn according to claim 1, wherein the reinforcing wire is partly or entirely cross-sectioned on the outer surface of the expanded graphite substrate. It is characterized by being embedded in a spiral shape in a state where it is bitten.

  In order to achieve the above object, the gland packing of the invention according to claim 4 is a gland packing in which a plurality of knitting yarns are braided or a plurality of knitting yarns are twisted. It is characterized in that a thin reinforcing wire having a wire diameter of 0.05 mm to 0.2 mm is embedded in a spiral shape in the longitudinal direction on the outer surface side of the expanded graphite base material. In this case, as described above, as the reinforcing wire, organic wire such as rayon, phenol, aramid, PBI, PBO, PTFE, PPS, and PEEK, inorganic wire such as glass fiber, carbon fiber, and ceramic fiber, mineral type Various wire rods such as fiber wire rods, metal wire rods such as stainless steel, Inconel, and Monel can be selectively used depending on applications.

  A gland packing according to a fifth aspect of the present invention is the gland packing according to the fourth aspect, wherein the expanded graphite base material of the knitting yarn is formed of an expanded graphite tape that is twisted, and the reinforcing wire is the twisted process. The expanded graphite base material is characterized in that it is embedded inside the expanded graphite tape edge along the edge of the expanded graphite tape exposed spirally on the outer surface of the expanded graphite substrate.

  The gland packing of the invention according to claim 6 is the gland packing according to claim 4, wherein the reinforcing wire of the knitting yarn bites a part or all of the cross section of the reinforcing wire into the outer surface of the expanded graphite base material. It is characterized in that it is buried in a spiral shape.

According to the expanded graphite knitting yarn of the invention according to claim 1, the reinforcing wire is constituted by a thin wire having a wire diameter of 0.05 mm to 0.2 mm, and the thin reinforcing wire is formed in the longitudinal direction on the outer surface side of the expanded graphite substrate. Since it is embedded in a spiral shape in the direction, the reinforcing wire resists the tensile and torsional forces generated in each knitting yarn when manufacturing the gland packing, and the expanded graphite base material is prevented from breaking. .
Moreover, since the reinforcing wire is simply wound around the outer periphery of the expanded graphite base material in a spiral shape, it can be wound in a very short time compared to the time required for conventional knit knitting and bag knitting to improve productivity. be able to.
In addition, the reinforcing wire is a thin wire having a wire diameter of 0.05 mm to 0.2 mm, and is embedded in a spiral shape on the outer periphery of the expanded graphite base material, so that it is covered with a conventional knitted or bag knitted reinforcing wire. Compared to knitting yarn made of graphite, the contact pressure and contact area of the expanded graphite substrate with respect to the mating member, such as the rotating shaft and stem, can be sufficiently secured, so that the compatibility with the mating member and the sealing performance can be improved. There is an effect.

  According to the second aspect of the present invention, the expanded graphite base material obtained by twisting the expanded graphite tape can improve the tensile strength and the twist strength of the expanded graphite base material itself. An expanded graphite knitting yarn resistant to twisting and twisting can be obtained. In addition, since the reinforcing wire is embedded inside the expanded graphite base material along the edge of the spiral expanded graphite tape, the entire outer surface of the expanded graphite substrate can be exposed and the expansion with respect to the counterpart member can be performed. The contact pressure and contact area of the graphite base material can be sufficiently secured, and the conformability and the sealing performance can be further improved.

  According to the third aspect of the present invention, the reinforcing wire is embedded in the spiral shape in a state where a part or all of the cross section of the reinforcing wire is engulfed on the outer surface side of the expanded graphite base material, and expands by the amount of the bite. Since the outer surface of the graphite base material can be brought close to the mating member, when the expanded graphite base material bulges by receiving a compressive load from the outside, it becomes easier to secure the contact pressure and the contact area with the mating member. The conformability to the member and the sealing performance can be further improved.

  According to the gland packing of the invention according to claim 4, a plurality of braided or twisted knitting yarns have a wire diameter of 0.05 mm to 0.2 mm in the longitudinal direction on the outer surface side of the expanded graphite base material. Since the thin reinforcing wire is embedded in a spiral shape, the reinforcing wire exerts sufficient external reinforcement resistance against the tensile and torsional forces generated in each knitting yarn when manufacturing the gland packing. it can. In addition, it is sufficient that the reinforcing wire is spirally wound around the outer periphery of the expanded graphite base material, so that it can be wound in a shorter time than the conventional knitted or bag knitted and covered, thereby improving productivity. Can do. In addition, the reinforcing wire is a thin wire having a wire diameter of 0.05 mm to 0.2 mm, and is embedded in a spiral shape on the outer periphery of the expanded graphite base material, so that it is covered with a large amount of conventional knitted or bag knitted reinforcing wire. Since the contact pressure and contact area of the expanded graphite base material with respect to the mating member can be sufficiently ensured as compared with the knitting yarn based on the graphite base material, the conformability to the mating member and the sealing performance can be improved.

  According to the gland packing of the invention described in claim 5, since the expanded graphite base material of the knitting yarn is formed by twisting the expanded graphite tape, the tensile strength and twist strength of the expanded graphite base material itself are set. In combination with the reinforcing action of the reinforcing wire, it is possible to obtain an expanded graphite knitting yarn that is strong against pulling and twisting. Moreover, since the reinforcing wire is embedded in the inside of the expanded graphite tape along the edge of the expanded expanded graphite tape, a gland packing having excellent conformability to the mating member and excellent sealing performance can be obtained.

  According to the gland packing of the invention described in claim 6, the reinforcing wire of the knitting yarn is embedded in a spiral shape in a state where a part or all of the cross section of the reinforcing wire is biting into the outer periphery of the expanded graphite base material. Therefore, it is easy to ensure the contact pressure and contact area of the expanded graphite base material with respect to the mating member, and a gland packing excellent in conformability to the mating member and sealing properties can be obtained.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.
1 (a) and 1 (b) are perspective views showing an embodiment of an expanded graphite knitting yarn according to the inventions of claims 1 and 2, in which an expanded graphite knitting yarn 1 is shown. As shown in FIG. 1 (a), the expanded graphite tape having a width of 2 to 30 mm (preferably 10 to 30 mm) and a thickness of 0.10 to 0.50 mm (preferably 0.20 to 0.40 mm) is twisted. As shown in FIG. 1 (b), a reinforcing wire 3 made of a metal wire that is easily plastically deformed on the outer surface side of the expanded graphite substrate 2 is exposed in a spiral shape on the outer surface of the expanded graphite substrate 2. It is wound so as to be embedded inside the tape edge 4. One or a plurality of reinforcing wires 3 are spirally wound in accordance with the twist pitch of the expanded graphite tape. The winding pitch P of the reinforcing wires 3 is preferably a narrow pitch of 0.5 mm to 5 mm. More preferably, it is wound in a spiral shape with a narrow pitch of 1 mm to 3 mm.

  As the reinforcing wire 3, a thin stainless steel wire (SUS304) having a wire diameter of 0.05 mm to 0.2 mm, preferably 0.1 mm to 0.2 mm is used, and this stainless steel wire is 0.1 N to 30 N, preferably The expanded graphite knitting yarn 1 is wound in a spiral shape so as to be embedded along the expanded graphite tape edge 4 on the outer surface side of the expanded graphite substrate 2 without loosening with a tightening strength of 10N to 20N. Is configured.

In this way, the reinforcing wire 3 is composed of a thin wire having a wire diameter of 0.05 mm to 0.2 mm, and this thin reinforcing wire 3 is disposed on the outer periphery of the expanded graphite base 2 along the edge 4 of the expanded graphite tape and on the inside thereof. By being embedded, it is possible to exert a sufficient external reinforcing force against the tensile force and torsional force generated in each knitting yarn 1 when the gland packing is manufactured.
Further, the reinforcing wire 3 can be simply wound around the outer surface of the expanded graphite base material 2 in a spiral shape, and can be wound in a shorter time than the conventional knit knitting or bag knitting to be coated. Can be increased.

  Moreover, since the reinforcing wire 3 is a thin wire having a wire diameter of 0.05 mm to 0.2 mm and is not exposed on the outer surface of the expanded graphite base material 2, the expanded graphite base with respect to the mating member such as the rotating shaft and the stem. The contact pressure and contact area of the material 2 can be sufficiently secured, and the conformability to the mating member and the sealing performance can be enhanced.

  Here, when the wire diameter of the reinforcing wire 3 is less than 0.05 mm, the reinforcing wire 3 is easily cut when it is wound with the tightening strength of 0.1N to 30N, and the expanded graphite base 2 There is no certainty of winding the outer periphery of the spiral in a spiral shape without loosening. Moreover, when the wire diameter of the reinforcing wire 3 exceeds 0.2 mm, it becomes difficult to be embedded inside the edge 4 of the expanded graphite tape. Therefore, it is preferable that the wire diameter of the reinforcing wire 3 is made of a thin wire of 0.05 mm to 0.2 mm, preferably 0.1 mm to 0.2 mm.

  As shown in FIG. 2, the reinforcing wire 3 is not limited to the one wound spirally along the expanded graphite tape edge 4 of the expanded graphite base 2 as shown in FIG. Further, one or more additional reinforcing wires 3 are used on the outer surface of the expanded graphite base material 2 and spirally wound in the opposite direction so as to intersect the spiral reinforcing wires 3, thereby crossing each other. It may be wound in a spiral shape. In this case, if the pitch P of the reinforcing wire 3 wound on the outer surface of the expanded graphite base material 2 is less than 0.5 mm as in the latter case, the surface occupation ratio of the reinforcing wire 3 becomes too high, and the expansion While it becomes difficult for the graphite base material 2 to bulge outward, the contact area of the expanded graphite base material 2 with respect to the mating member is also reduced, and the conformability and sealing performance are reduced. When the pitch P exceeds 5 mm, the winding angle of the reinforcing wire 3 with respect to the axis of the expanded graphite substrate 2 twisted is small even if the reinforcing wire 3 is wound around the expanded graphite substrate 2 without loosening. Thus, sagging easily occurs in the reinforcing wire 3. Therefore, the reinforcing wire 3 needs to be wound around the outer periphery of the expanded graphite base material 2 with a narrow pitch of 0.5 mm to 5 mm.

FIG. 3 is a perspective view showing an embodiment of an expanded graphite knitting yarn according to the inventions of claims 1 and 3, wherein the expanded graphite knitting yarn 1 has a width of 2 mm to 30 mm (preferably 10 mm to 30 mm). ), On the outer surface of the expanded graphite substrate 2 obtained by twisting an expanded graphite tape having a thickness of 0.10 mm to 0.50 mm (preferably 0.20 mm to 0.40 mm), and having a wire diameter of 0.05 mm to 0.2 mm. A thin reinforcing wire 3 is embedded in a spiral shape with a part of its cross section biting in. In this case, the reinforcing wire 3 may be embedded in the outer surface of the expanded graphite base material 2 in a spiral shape so that the entire cross section of the reinforcing wire 3 is bitten. Moreover, you may use 2 or more of the reinforcing wire 3 to be entrapped as needed.
On the other hand, the reinforcing wire 3 may be wound in a spiral shape in opposite directions to form two or more spiral outer reinforcements intersecting each other. In addition, the winding pitch of the reinforcing wire 3 is wound in a single spiral shape without loosening at a narrow pitch of 0.5 mm to 5 mm, preferably a narrow pitch of 1 mm to 3 mm, as in the case of the above embodiment. The

  When the reinforcing wire 3 is embedded in a spiral shape with a part or all of the cross section of the reinforcing wire 3 biting into the outer surface of the expanded graphite base 2 in this manner, the reinforcing wire 3 as shown in FIG. Since the outer surface of the expanded graphite base material 2 can be brought closer to the counterpart member 9 by the amount of the bite, the expanded graphite base material 2 expands as shown by a broken line e when it receives a compressive load from the direction C in the figure. By taking out, it becomes easy to ensure the contact pressure and contact area of the expanded graphite base material 2 with respect to the counterpart member 9, and the conformability to the counterpart member 9 and the sealing performance can be further improved.

Next, an embodiment of a gland packing according to the invention described in claim 4 will be described.
As shown in FIG. 5, the gland packing 4 converges eight expanded graphite knitting yarns 1 (1A) shown in FIG. 1B and the expanded graphite knitting yarn 1 (1B) shown in FIG. It is a knitted corner knitting. In addition, as the reinforcing wire 3 of each expanded graphite knitting yarn (1A) (1B), a metal wire such as Inconel, Monel or the like having a characteristic of being easily plastically deformed is used in addition to the stainless steel wire. Of course, it may be. Of course, it is not limited to 8-striking knitting, but may be 16-striking knitting, 18-striking knitting, 24-beating knitting, 32-stroke knitting, or cylindrical knitting with an inner core inside. is there.

(Other embodiments)
The expanded graphite base material 2 may be an expanded graphite base material 2 formed by stacking a plurality of expanded graphite tapes as shown in FIG. 6 (a), or as shown in FIG. 6 (b). Even if the expanded graphite base material 2 is configured by folding the tape in the longitudinal direction, the expanded graphite base material 2 configured by folding the expanded graphite tape in the longitudinal direction as shown in FIG. 6C. Alternatively, it may be a bar-like or string-like expanded graphite substrate 2 having a solid cross section. In addition, the expanded graphite substrate 2 obtained by twisting the expanded graphite substrate 2 shown in FIGS. 6A to 6C may be used.

  Of course, the form of the gland packing 4 is not limited to the gland packing in which a plurality of expanded graphite knitting yarns 1 are braided. For example, a gland packing obtained by twisting a plurality of expanded graphite knitting yarns 1 may be used.

Example 1
An example of expanded graphite knitting yarn will be given. An expanded graphite base 2 is made by twisting an expanded graphite tape having a width of 20 mm and a thickness of 0.2 mm, and the outer surface of the expanded graphite base 2 is made of a stainless steel wire having a wire diameter of 0.05 mm to 0.2 mm. An expanded graphite knitting yarn having an outer diameter of about 3 mm, wound in a single spiral without loosening at a pitch of 0.5 mm to 6.0 mm so as to embed the reinforcing wire 3 along the edge 4 of the expanded graphite tape. 1A (expanded graphite knitting yarn 1 in FIG. 1 (b)), and a reinforcing wire 3 having the same wire diameter range as that described above on the outer periphery of the expanded graphite substrate 2, and the reinforcing wire 3 in the same range as described above. The expanded graphite knitting yarn 1B (expanded graphite knitting yarn 1 in FIG. 2) having an outer diameter of about 3 mm wound in two spirals intersecting each other without loosening was prepared.

The stiffening pressure 39.2 MPa, the pressure of hot water x temperature: 17.2 MPa, the reinforcing wire rods 1 A and 2 B thus made and the expanded graphite knitting yarns 1 A, 1 B in a ring shape with an inner diameter of 32 mm and the stem sealed The chart of FIG. 7 shows the results of the hot water leakage test after 3 hours (500 reciprocations) in the first cycle, the second cycle, and the third cycle under the condition of × 350 ° C.
As is apparent from this chart, it was confirmed that any of the expanded graphite knitting yarns 1A and 1B was excellent in the conformability to the stem and the sealing property and had no leakage.

Example 2
An example of a gland packing will be given. Expanded graphite knitting yarns 1A and 1B similar to the one and two expanded graphite knitting yarns 1A and 1B prepared in Example 1 were prepared. Eight and sixteen expanded graphite knitting yarns 1A and 1B were prepared. , 24 and 32 bundles to create 8-pack, 16-stroke, 18-stroke, 24-stroke, and 32-stroke knitting gland packings, and each gland packing is a ring with an inner diameter of 32 mm The stem was shaft-sealed, and the clamping pressure was 39.2 MPa, hot water pressure × temperature: 17.2 MPa × 350 ° C., 3 hours (500 hours for the first cycle, the second cycle, and the third cycle). The result of the hot water leakage test after (reciprocating) is shown in the chart of FIG.
As is clear from this chart, it was confirmed that any of the gland packings had excellent compatibility with the stem and sealability and no leakage.

(A) is a perspective view which shows embodiment of the expanded graphite base material which carried out the twist process, (b) is a perspective view which shows embodiment of the expanded graphite knitting yarn which concerns on invention of Claim 1 and Claim 2 It is. It is a perspective view which shows other embodiment of the expanded graphite knitting yarn. It is a perspective view which shows embodiment of the expanded graphite knitting yarn which concerns on invention of Claim 3. It is explanatory drawing which shows the relationship between the expanded graphite knitting yarn of FIG. 3, and the other party member. It is a perspective view which shows an example of embodiment of the gland packing which concerns on invention of Claim 4. (A), (b), (c) is the schematic which shows other embodiment of an expanded graphite member. It is a graph which shows the result of the hot water leak test of an expanded graphite knitting yarn. It is a graph which shows the result of the leak test of the hot water of a gland packing. It is the schematic which shows an example of the usage pattern of a gland packing. It is explanatory drawing which shows the contact condition of the expanded graphite knitting yarn of a prior art example, and the other party member.

Explanation of symbols

1 Expanded Graphite Knitting Yarn 2 Expanded Graphite Base 3 Reinforcing Wire 4 Expanded Graphite Tape Edge 5 Gland Packing

Claims (6)

  An expanded graphite knitting yarn characterized in that a thin reinforcing wire having a wire diameter of 0.05 mm to 0.2 mm is embedded in a spiral shape in the longitudinal direction on the outer surface side of the expanded graphite substrate. In the expanded graphite knitting yarn according to claim 1,
The expanded graphite base is formed of a twisted expanded graphite tape, and the reinforcing wire extends along the edge of the expanded graphite tape exposed in a spiral shape on the outer surface of the expanded graphite base. An expanded graphite knitting yarn embedded in the edge. In the expanded graphite knitting yarn according to claim 1,
An expanded graphite knitting yarn, wherein the reinforcing wire is embedded in a spiral shape in a state in which a part or all of the cross section of the reinforcing wire is bitten into the outer surface of the expanded graphite substrate. In gland packing in which a plurality of yarns are braided or a plurality of yarns are twisted,
A gland packing, wherein the knitting yarn is a thin reinforcing wire having a wire diameter of 0.05 mm to 0.2 mm embedded in a spiral shape in the longitudinal direction on the outer surface side of the expanded graphite base material. In the gland packing according to claim 4,
The expanded graphite base material of the knitting yarn is formed of an expanded graphite tape that is twisted, and the reinforcing wire is formed on the edge of the expanded graphite tape that is exposed spirally on the outer surface of the twisted expanded graphite base material. And a gland packing embedded inside the edge of the expanded graphite tape. In the gland packing according to claim 4,
A gland packing in which the reinforcing wire of the knitting yarn is embedded in a spiral shape in a state where a part or all of the cross section of the reinforcing wire is bitten into the outer surface of the expanded graphite base material.

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