JP4759530B2 - Gland packing - Google Patents

Description

  The present invention relates to a gland packing used for a shaft seal portion of a fluid device.

  Conventionally, as a plurality of knitting yarns in a braided gland packing, for example, knitting yarns described in Japanese Patent Publication No. 6-27546 and JP-A-6-74346 are known. The knitting yarn is bent so that the expanded graphite tape is contracted in the width direction, and the entire outer periphery of the bent expanded graphite tape has a mesh without using an adhesive or a fusing material. It is covered only with a reinforcing material made of a body.

  By the way, expanded graphite tape is vulnerable to tension and torsion, so in the knitting yarn in the gland packing, unintentionally, cracks (cracks) have occurred at the end of the expanded graphite tape in the width direction. There is. The larger the number of cracks, the larger the cracks, and the greater the number of knitting yarns with cracks, the worse the seal performance of the gland packing. Will come.

  In addition, even if there is no crack immediately after the production of the gland packing, after the production, the crack may occur when the gland packing is compression-molded to a predetermined dimension or compression-molded into a ring shape. When the device is sealed as a set, the crack may occur due to a strong tightening force. Of course, if the crack is generated immediately after the production of the gland packing, the crack is enlarged by the compression molding or the tightening force.

  Accordingly, an object of the present invention is to provide a gland packing capable of suppressing deterioration in seal performance due to the above-described cracks that occur unintentionally.

In order to achieve the above object, the gland packing according to the invention described in claim 1 is a plurality of knitting yarns in the braided gland packing, and the entire outer periphery of the expanded graphite tape is an adhesive in the knitting yarns. Covered with a reinforcing wire consisting of a knit braid or braided body having a mesh without using any fusion material, and the expanded graphite tape leaves an intermediate portion in the width direction of the expanded graphite tape. Further, a separation space is formed between at least one of the edges of the both ends and the intermediate portion of the expanded graphite tape so that both ends in the width direction face each other inward in the width direction of the knitting yarn. use was developed as the and expanded graphite tape is bent so as contracted in the width direction, and yarns having both ends folded in the width direction of the bent expanded graphite tape Bei It is characterized in that is.

Further, the gland packing according to the invention of claim 2 is a plurality of knitting yarns in the twisted gland packing, and in the knitting yarns, the inside of the expanded graphite tape in which the entire outer periphery is exposed. Reinforcing wire is embedded in the longitudinal direction, and the expanded graphite tape is mutually connected with both ends in the width direction facing inward in the width direction of the knitting yarn, leaving an intermediate portion in the width direction of the expanded graphite tape. Further, the expanded graphite tape is used in a width direction so that a space is formed between at least one of the edges of the both ends and the intermediate portion of the expanded graphite tape so as to face each other. And a knitting yarn that is folded back at both ends in the width direction of the expanded graphite tape is provided.

According to the gland packing according to the first and second aspects of the present invention, in the knitting yarn in the gland packing, the stretched graphite tape folded so as to shrink in the width direction is further folded at both ends in the width direction. By providing the knitting yarn, even if a crack is generated at the end in the width direction of the expanded graphite tape, if the crack is large, the expanded graphite tape is folded and reduced. In the case of a crack, it will be in a state facing the outer piece of the expanded graphite tape that has been bent, and the crack will not be exposed in a state of being straightened out as it is. be able to.
In addition, the gland packing according to claim 1 or 2 may be compression-molded to a predetermined size after production, or may be compression-molded to form a ring, and when sealing as a set to the device, Even in such a case, if the knitting yarn as described above is provided, the both ends of the expanded graphite tape in the width direction are folded back, so that cracks hardly occur, and In the case where a crack is generated, the expansion of the crack can be suppressed.
Furthermore, the more knitting yarns as mentioned above are added to the gland packing, the less the influence of cracks at the end of the expanded graphite tape in the width direction becomes. Can be suppressed.

  According to the gland packing of the present invention, it is possible to suppress a situation in which the seal performance of the gland packing is deteriorated due to a crack generated at or from an end of the expanded graphite tape in the width direction, and reliable. It is possible to provide a gland packing that exhibits high performance and stable sealing performance.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings. FIG. 1 is a schematic external perspective view of an example of an embodiment of a braided gland packing according to the invention as set forth in claim 1, and FIG. 2 is a twisted gland packing according to the invention as set forth in claim 2. It is an outline appearance perspective view of an example which is an embodiment.

In these braided gland packings 1 and twisted gland packings 2, at least one, preferably more than half, and more preferably all of the knitting yarns 10 constituting them are expanded graphite tape as shown in FIG. 30 of the both ends 31 and 31 so that both ends 31 and 31 of the width direction may face each other toward the inner side in the width direction of the knitting yarn, leaving the intermediate portion 30A of the expanded graphite tape 30 in the width direction. using what spaced space 31A between the edge and the middle portion 30A of the expanded graphite tape 30 is created so as to form, bent Ri folding as expanded graphite tape 30 of a predetermined width is shortened in the width direction Then, both ends 31, 31 in the width direction of the expanded graphite tape 30 thus folded are folded back so as to face the expanded graphite tape 30, and the entire outer periphery thereof is bonded. Only reinforcing wire member 40 of the knitted or braided material having a mesh coated with yarns 10A are provided without using or fusion material.

  Examples of the reinforcing wire 40 of the knitting yarn 10A include metal wires such as stainless steel, inconel and monel, organic fibers such as cotton, rayon, phenol, aramid, PBO, PBI, PTFE, PPS and PEEK, carbon fibers and ceramic fibers. Inorganic fibers can be used as appropriate.

  Further, in the gland packings 1 and 2, as the knitting yarn that is not the knitting yarn 10A, an appropriate knitting yarn using expanded graphite or expanded graphite tape can be used. For example, FIG. ) (B) (C) (D) (E), the expanded graphite tape 30 having a predetermined width is bent so as to shrink in the width direction, and the entire outer periphery of the expanded graphite tape 30 is folded with adhesive or fusion. What is covered with only the reinforcing wire 40 made of a knit knitted or braided body having a mesh without using a material is preferable because it is the same type.

  If such a knitting yarn 10A is provided in the braided gland packing 1 or in the twisted gland packing 2, as shown in FIG. 4, end portions 31, 31 in the width direction of the expanded graphite tape 30 are provided. Even if cracks 32 and 32 are generated, the cracks 32 and 32 are in the inside (inside) of the outer piece 33 of the folded expanded graphite tape 30 and face the outer piece 33. 5, the deterioration of the seal performance of the gland packings 1 and 2 can be suppressed as compared with the case where the cracks 32 and 32 are exposed straightly as they are.

  Further, even when the cracks 32 and 32 of the end portions 31 and 31 of the expanded graphite tape 30 are considerably large reaching the outer piece 33 over the end portions 31 and 31, Since the cracks 32 and 32 are folded into, for example, two and are reduced, deterioration of the seal performance of the gland packings 1 and 2 can be suppressed.

  Further, after the gland packings 1 and 2 are manufactured, the above-described knitting yarn is also compressed when it is compression-molded to a predetermined size, compression-molded on a ring, or subjected to a large tightening force at the time of sealing. If 10A is provided, since the end portions 31, 31 in the width direction of the expanded graphite tape 30 are folded back, generation of cracks and expansion of cracks can be suppressed.

The more yarns 10A as described above are added to the gland packings 1 and 2,
Of course, the influence of cracks at the end portions 31 in the width direction of the expanded graphite tape 30 is reduced, and it is possible to more effectively suppress the deterioration of the seal performance of the gland packings 1 and 2 due to the cracks. is there.

  In the above embodiment, the case where at least one of the gland packings 1 and 2 is used as the knitting yarn 10A has been shown, but of course, not limited to the form of the knitting yarn 10A, for example, FIGS. (C) may be in the form of a knitting yarn 10A, and the bending method of bending the expanded graphite tape 30 so as to shrink in the width direction, and the end portions 31 and 31 in the width direction of the expanded graphite tape 30 are provided. The other way of folding may be used. In addition, about each knitting yarn 10A of FIG. 6 (A) (B) (C), description is abbreviate | omitted by attaching | subjecting the same code | symbol to the part corresponding to the knitting yarn 10A of the said embodiment.

Further, in each of the embodiments illustrated in FIGS. 4 and 6 , the case where the reinforcing wire rod 40 having a mesh made of knit knitting or braided body is used is shown. As shown in FIG. 8 showing the embodiment of the present invention, between the expanded graphite tape 30 and the folded expanded graphite tape 30 in which a plurality of wires are embedded in the longitudinal direction at predetermined intervals inside the expanded graphite tape 30 with the entire outer periphery exposed. A knitting yarn 10A employing at least one of the reinforcing wire rods 42 arranged in the longitudinal direction, or a knitting yarn 10A combining all of the reinforcing wire rod 40 and the reinforcing wire rods 41, 42, or the reinforcing wire rod 40 A knitting yarn 10A in which any one of the reinforcing wire members 41 and 42 is combined may be used.

  The reinforcing wires 41 and 42 are made of metal wires such as stainless steel, inconel and monel, and organic fibers such as cotton, rayon, phenol, aramid, PBO, PBI, PTFE, PPS and PEEK as in the case of the reinforcing wire 40. Inorganic fibers such as carbon fibers and ceramic fibers can be used. In some cases, the reinforcing wires 41 and 42 and the expanded graphite tape 30 may be fixed to each other with an adhesive interposed therebetween.

4 and FIG. 6 and the embodiment illustrated in FIG. 8 show the case where the expanded graphite tape 30 is one sheet. Of course, the expanded graphite tape 30 is not limited to a single sheet. The present invention can also be applied by stacking a plurality of sheets.

Furthermore, as can be said in common with the above embodiment, the present invention is not limited to the braided gland packing 1 and the twisted gland packing 2 illustrated in FIGS. The braided gland packing and twisted gland packing of the present invention can be applied, and the characteristic time of forming the knitting yarn in the gland packing of the present invention is not limited to before braiding or before twisting, but braided or twisted. Further, the expanded graphite tape 30 may be formed by receiving a strong clamping force when the gland packing is later compression-molded to a predetermined size, formed into a ring shape, or set in a device. If you want to suppress the occurrence of cracks and crack expansion at the edges in the width direction, complete the folding when the compression force is applied. Cormorant may be to suppress the spread of crack generation and crack in the.

It is a general | schematic external appearance perspective view which shows an example of embodiment of the braided gland packing which concerns on invention of Claim 1. It is a general | schematic external appearance perspective view which shows an example of embodiment of the gland packing by which the twist process which concerns on invention of Claim 2 was carried out. It is a partial expansion perspective view which shows the knitting yarn in the gland packing which is embodiment of the gland packing which concerns on invention of Claim 1. It is sectional drawing of the knitting yarn of FIG. It is sectional drawing of the knitting yarn of a comparative example. (A)-(C) are sectional drawings which show other embodiment of the knitting yarn in the gland packing which is embodiment of the gland packing which concerns on invention of Claim 1. FIG. (A)-(E) are sectional drawings which show the knitting yarn combined with the knitting yarn of the gland packing which is embodiment of the gland packing which concerns on invention of Claim 1. FIG. It is sectional drawing which shows embodiment of the knitting yarn in the gland packing which concerns on invention of Claim 2.

DESCRIPTION OF SYMBOLS 1 Braided gland packing 2 Twist processed gland packing 10 Knitting yarn in gland packing 10A Knitted yarn in which both ends of expanded graphite tape are folded 20 Knitting yarn in gland packing 20A The outer end of expanded graphite tape is folded back Knitting yarn 30 expanded graphite tape
30A Expanded graphite tape width direction intermediate portion 31 Expanded graphite tape width direction end
31A separation space 32 Crack 33 Expanded graphite tape outer piece 40 Reinforcement wire 41 Reinforcement wire 42 Reinforcement wire

Claims (2)

In a plurality of knitting yarns in the braided gland packing, the entire outer periphery of the expanded graphite tape is composed of a knit knitting or a braided body having a mesh without using an adhesive or a fusion material. The expanded graphite tape is covered only with a reinforcing wire, and the expanded graphite tape is opposed to each other with both ends in the width direction facing inward in the width direction of the knitting yarn, leaving an intermediate portion in the width direction of the expanded graphite tape. As described above, the expanded graphite tape is contracted in the width direction by using a material formed so that a separation space is formed between at least one of the edges of the both ends and the intermediate portion of the expanded graphite tape. A gland packing which is provided with a knitting yarn which is bent at both ends in the width direction of the expanded graphite tape. In a plurality of yarns in the gland packing and twisting process, among them the knitting yarn, is embedded reinforcing wire longitudinally oriented within the expanded graphite tape to expose the entire periphery, and the The expanded graphite tape further includes at least one end edge of the both ends so that both ends in the width direction face each other inward in the width direction of the knitting yarn, leaving an intermediate portion in the width direction of the expanded graphite tape. And the expanded graphite tape is bent so as to be contracted in the width direction, and the expanded graphite tape is expanded so that a space is formed between the expanded graphite tape and an intermediate portion of the expanded graphite tape. A gland packing comprising a knitting yarn in which both ends in the width direction of a graphite tape are folded.

Images