JP6349239B2 - Packing - Google Patents

Description

  The present invention relates to a packing configured using yarn.

  Conventionally, a fluid device such as a pump or a valve is provided with a packing (gland packing) which is a shaft seal component. As such packing, what was comprised by twisting or braiding a plurality of yarns (knitting yarn) is used (for example, refer to Patent Document 1).

  In this type of gland packing, at least one yarn included in a plurality of yarns is provided with a cylindrical member 92 formed by knitting a wire 91, for example, as shown in FIG. Many expanded graphite sheet pieces 93 are provided. The yarn is configured by loading the expanded graphite sheet piece 93 into the tubular member 92 such that the expanded graphite sheet piece 93 extends in the axial direction of the tubular member 92.

  In the yarn 1, when the expanded graphite sheet piece 93 is filled in the tubular member 92, one end portion 95 in the longitudinal direction of the expanded graphite sheet piece 93 and the other longitudinal direction of the other expanded graphite sheet piece 93. A relatively large gap 98 was provided between the end 96. The gap 98 has a problem in that the expanded graphite sheet piece 93 in the tubular member 92 having a stitch at the time of twisting or braiding of the yarn 1 protrudes outside the tubular member 92 and the protruding portion is missing. It is provided to suppress this.

  However, due to the presence of the gap 98, the filling density of the expanded graphite sheet pieces 93 in the cylindrical member 92 is not constant over the longitudinal direction of the yarn 1, and the thickness of the yarn tends to be uneven. In addition, this may lead to a result that adversely affects the sealing performance in a packing configured using a plurality of yarns including the yarn.

JP 2007-138315 A

  The present invention has been made in view of such circumstances, and in a packing constituted by using a yarn in which a tubular member is filled with a plurality of expanded graphite sheet pieces, a good sealing property is ensured. It is an object to provide a packing that can be used.

The invention described in claim 1
In a packing constituted by twisting or braiding a plurality of yarns,
The tubular member is provided with a large number of elongated graphite sheet pieces formed in an elongated shape, and the expanded graphite sheet piece is loaded into the tubular member so that the expanded graphite sheet piece extends in the axial direction of the tubular member. And the yarns included in the plurality of yarns,
The expanded graphite sheet piece is formed in one end in the longitudinal direction that is tapered toward one side in the axial direction of the cylindrical member, and is formed in a tapered shape toward the other side in the axial direction of the cylindrical member. Having a longitudinal other end,
One end in the longitudinal direction of the expanded graphite sheet piece is the other end in the longitudinal direction of the other expanded graphite sheet piece located on the other axial side of the tubular member of the expanded graphite sheet piece, and the cylindrical member. It is provided so as to face each other in the radial direction.

  According to this configuration, in the yarn included in the plurality of yarns, the expanded graphite sheet piece has a longitudinal end formed in a gap formed by the other longitudinal end of the other expanded graphite sheet piece. It becomes possible to accommodate in the said cylindrical member so that it may enter. Therefore, it is possible to prevent the gap from being generated as much as possible in the portion where the one end in the longitudinal direction and the other end in the longitudinal direction overlap, or to reduce the size of the generated gap as much as possible.

  Therefore, the expanded graphite sheet pieces can be distributed in the cylindrical member so that the packing density is as constant as possible in the longitudinal direction of the yarn, and the thickness of the yarn can be kept as uniform as possible. As a result, when the packing is formed using the yarn, it is possible to suppress the adverse effect caused by the difference in the thickness of the yarn on the sealing performance of the packing. Therefore, it is possible to ensure good sealing performance with respect to the packing.

  Preferably, as described in claim 2, the expanded graphite sheet piece is provided with a sharply sharp tip at each of the one end in the longitudinal direction and the other end in the longitudinal direction.

  Preferably, as described in claim 3, the expanded graphite sheet piece has a parallelogram shape extending along the longitudinal direction of the expanded graphite sheet piece when viewed from a direction orthogonal to the axial direction of the cylindrical member. Can be exhibited.

  ADVANTAGE OF THE INVENTION According to this invention, in the packing comprised using the yarn formed by filling a cylindrical member with several expanded graphite sheet pieces, the packing which can ensure favorable sealing performance can be provided.

It is a perspective view of the packing which concerns on one Embodiment of this invention. It is a model side view which shows the filling state of the expanded graphite sheet piece to the cylindrical member in a part of yarn in the packing of FIG. It is a perspective view of the expanded graphite sheet piece of FIG. It is a figure which shows the method of preparation of the expanded graphite sheet piece of FIG. It is a schematic block diagram which shows an example of the manufacturing apparatus for manufacturing the yarn of FIG. It is a figure which shows the mode at the time of filling of the expanded graphite sheet piece to a cylindrical member in the manufacturing apparatus of FIG. It is a schematic block diagram of the experimental apparatus used for confirmation of a gas seal characteristic. It is a figure which shows the experimental result by the experimental apparatus of FIG. (A) It is a perspective view which shows the packing of the implementation goods after being used by the experimental apparatus of FIG. 7, (b) is a figure which shows the packing of the conventional goods after being used by the experimental apparatus of FIG. It is a schematic side view which shows the filling state of the expanded graphite sheet piece to the cylindrical member in a part of yarn in the conventional packing.

  An embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the packing (gland packing) 2 according to an embodiment of the present invention twists or braids a plurality of yarns 3 including the yarn 1 around a core material 4 (here, It is formed in a string shape by performing eight-hit angle knitting with eight yarns. In the gland packing 2, it is sufficient that the yarn 1 is included in the plurality of yarns 3, but it is preferable that all of the plurality of yarns 3 are the yarns 1.

  As shown in FIGS. 1 and 2, the yarn 1 includes a cylindrical member 6. The yarn 1 further includes a large number of expanded graphite sheet pieces 7 formed in an elongated shape so as to be accommodated in the tubular member 6. The yarn 1 is loaded with the expanded graphite sheet piece 7 in the cylindrical member 6 in a state where the longitudinal direction of the expanded graphite sheet piece 7 is substantially aligned with the axial direction of the cylindrical member 6. It is configured.

  In the yarn 1, the expanded graphite sheet piece 7 has a longitudinal end 11 formed in a tapered shape toward one axial direction of the cylindrical member 6, and the axial direction of the cylindrical member 6. The other end portion 12 in the longitudinal direction is formed in a tapered shape toward the other side. And the longitudinal direction one end part 11 of the said expanded graphite sheet piece 7 is the other longitudinal direction other end of the said expanded graphite sheet piece 7 located in the axial direction other side of the said cylindrical member 6 of this expanded graphite sheet piece 7. The portion 12 is provided so as to face the radial direction of the tubular member 6.

  With such a configuration, the tubular member is arranged such that one end portion 11 in the longitudinal direction of the expanded graphite sheet piece 7 enters a gap formed by the other end portion 12 in the longitudinal direction of the other expanded graphite sheet piece 7. 6 can be accommodated. Therefore, it is possible to prevent a gap from being generated as much as possible or to reduce the size of the generated gap as much as possible in a portion where the one end 11 in the longitudinal direction and the other end 12 in the longitudinal direction overlap.

  Therefore, it is possible to keep the thickness of the yarn 1 as uniform as possible by distributing the expanded graphite sheet pieces 7 in the cylindrical member 6 so that the packing density thereof is as constant as possible over the longitudinal direction of the yarn 1. it can. As a result, it is possible to suppress the adverse effect caused by the difference in the thickness of the yarn 1 on the gland packing 2 formed using the yarn 1.

  That is, when the yarn 1 is used for the gland packing 2, the yarn 1 has a uniform thickness as much as possible, so that the plurality of yarns 3 can be easily knitted. Therefore, it is possible to suppress variations in the thickness (dimension in the direction substantially perpendicular to the longitudinal direction) and density of the gland packing 2. Therefore, it is possible to ensure a good sealing property for the gland packing 2.

  In the present embodiment, as shown in FIG. 2, the tubular member 6 has a mesh structure. Specifically, the tubular member 6 is a circular knitted structure having a stitch 14 by knitting the wire 13. The tubular member 6 is formed to have an internal space in which the expanded graphite sheet pieces 7 can be arranged side by side in the axial direction and the radial direction (direction orthogonal to the axial direction).

  As the wire 13, a metal wire such as an Inconel wire or a stainless steel wire is employed. Specifically, the wire 13 is, for example, a round wire having a diameter of about 0.1 mm.

  The expanded graphite sheet piece 7 has the tubular shape so as to be aligned in the axial direction and the radial direction of the tubular member 6 in a state where the longitudinal direction thereof is substantially along the axial direction of the tubular member 6. The member 6 is accommodated with almost no twist. As shown in FIG. 3, the expanded graphite sheet piece 7 has a length L shorter than the axial length of the tubular member 6, and a width W shorter than the radial width of the tubular member 6. And a strip having a thickness T equal to or smaller than the width W.

  Specifically, the expanded graphite sheet piece 7 has, for example, a length L of about 100 to 300 mm (preferably 150 to 250 mm) and a length of about 0.5 to 2.5 mm (preferably 0.5 to 1.5 mm). And a width T of about 0.2 to 1.0 mm (preferably 0.3 to 0.8 mm). The value of the width W here is for the width of the midway portion 15 in the longitudinal direction of the expanded graphite sheet piece 7.

  As shown in FIGS. 2 and 3, the one end portion 11 in the longitudinal direction is formed so as to gradually become narrower from the midway portion 15 side in the longitudinal direction toward the tip 17 on one side in the longitudinal direction. Specifically, the one end portion 11 in the longitudinal direction has a first side surface 18 extending along the longitudinal direction of the expanded graphite sheet piece 7 and a second side surface inclined with respect to the outer shape that is tapered toward the tip end 17. 19, and the tip 17 is positioned at a position where these side surfaces 18 and 19 (or an extension thereof) intersect.

  On the other hand, the other end portion 12 in the longitudinal direction is formed so as to be gradually narrowed from the midway portion 15 side in the longitudinal direction toward the tip 22 on the other side in the longitudinal direction. Specifically, the other end 12 in the longitudinal direction has a third side surface 23 extending along the longitudinal direction of the expanded graphite sheet piece 7 and a fourth side inclined with respect to the outer shape that is tapered toward the tip 22. The front end 22 is positioned at a position where both side faces 18 and 19 (or an extension line thereof) intersect.

  Here, the one end portion 11 in the longitudinal direction and the other end portion 12 in the longitudinal direction are arranged substantially symmetrical with respect to the center point of the midway portion 15 in the longitudinal direction. That is, the longitudinal direction one end portion 11 is provided so that the second side surface 19 faces the space on one side in the width direction of the expanded graphite sheet piece 7. The other end 12 in the longitudinal direction is provided such that the fourth side surface 24 faces the space on the other side in the width direction of the expanded graphite sheet piece 7.

  In the present embodiment, the expanded graphite sheet piece 7 is sequentially inserted into the cylindrical member 6 from the one end portion 11 in the longitudinal direction (the tip 17) through an opening on one end side in the axial center direction, It is accommodated in the cylindrical member 6. The expanded graphite sheet piece 7 accommodated in the tubular member 6 is held in a state where the other end 12 in the longitudinal direction (the tip 22) faces the opening.

  In this holding state, the other end portion 12 in the longitudinal direction of the expanded graphite sheet piece 7 is displaced in the axial direction of the tubular member 6 with respect to the other end portion 12 in the longitudinal direction of the other expanded graphite sheet piece 7. Placed in position. And since the said other end part 12 in a longitudinal direction is a tapered shape, until the said expanded graphite sheet piece 7 is newly inserted in the said cylindrical member 6, and is accommodated, the said other end part 12 side in the said longitudinal direction A space will be formed in the direction.

  Therefore, when the expanded graphite sheet piece 7 is inserted into the cylindrical member 6 later, since the longitudinal end portion 11 has a tapered shape, the expanded graphite sheet piece 7 is The tubular member 6 is accommodated in the tubular member 6 so as to enter the space formed on the side of the other end 12 in the longitudinal direction of the other expanded graphite sheet piece 7 inserted first in the tubular member 6. be able to.

  Preferably, as shown in FIG. 2 and FIG. 3, the tip 17 is formed to be sharpened at one end 11 in the longitudinal direction of the expanded graphite sheet piece 7. Further, at the other end portion 12 in the longitudinal direction of the expanded graphite sheet piece 7, the tip 22 is formed so as to have an acute angle.

  That is, in the width direction of the expanded graphite sheet piece 7, an angle Θ <b> 1 formed by the first side surface 18 and the second side surface 19 of the one end portion 11 in the longitudinal direction is an acute angle. In the width direction of the expanded graphite sheet piece 7, an angle Θ2 formed by the third side surface 23 and the fourth side surface 24 of the other end portion 12 in the longitudinal direction is an acute angle.

  Specifically, the angle Θ1 is set to, for example, an angle within a range of 5 to 60 °, more preferably 5 to 45 °. The angle Θ2 is specifically set to an angle in the range of 5 to 60 °, more preferably 5 to 45 °, for example.

  Preferably, as shown in FIGS. 2 and 3, the expanded graphite sheet piece 7 is along the longitudinal direction of the expanded graphite sheet piece 7 when viewed from a direction orthogonal to the axial direction of the cylindrical member 6. It is assumed that it can exhibit an extended parallelogram shape. That is, the angle Θ1 on the one end 11 side in the longitudinal direction and the angle Θ2 on the other end 12 side in the longitudinal direction are substantially the same angle.

  In this case, as shown in FIG. 4, the expanded graphite sheet piece 7 is continuously cut by cutting a rectangular expanded graphite sheet 26 having a predetermined width every predetermined width on a plane inclined with respect to the longitudinal direction. It becomes possible to create. Therefore, the creation of the expanded graphite sheet piece 7 can be facilitated.

  In this embodiment, the yarn 1 can be manufactured using a manufacturing apparatus 30 as shown in FIG. The manufacturing apparatus 30 includes a supply mechanism 31, a transport mechanism 32, a cutting mechanism 33, a guide supply mechanism 34, and a knitting machine 35.

  The supply mechanism 31 includes a reel 41. The reel 41 is configured to be able to wind a rectangular expanded graphite sheet 26 having a predetermined width, and is provided to be rotatable around a rotation shaft 43. The expanded graphite sheet 26 wound around the reel 41 is unwound when the reel 41 rotates in the direction of the arrow 44 shown in FIG.

  The transport mechanism 32 includes a pair of rollers 45 and 46 and a transport drive unit 47. The pair of rollers 45 and 46 are configured to be able to sandwich a part of the expanded graphite sheet 26 unwound from the reel 41 by the supply mechanism 31. The conveyance drive unit 47 is configured to be able to rotationally drive at least one of the pair of rollers 45 and 46.

  In the transport mechanism 32, when at least one of the pair of rollers 45 and 46 is rotationally driven by the transport drive unit 47, the pair of rollers 45 and 46 pulls a part of the sandwiched expanded graphite sheet 26, and the reel The expanded graphite sheet 26 unwound from 41 can be sent out toward the cutting mechanism 33.

  The cutting mechanism 33 includes a cutting blade 50, a cutting drive unit 51, and a cradle 52. The cutting blade 50 is configured to be able to cut the expanded graphite sheet 26 along a plane inclined with respect to the conveying direction. The cutting drive unit 51 is configured to reciprocate the cutting blade 50 in the approaching / separating direction with respect to the expanded graphite sheet 26. The cradle 52 is arranged to make a pair with the cutting blade 50.

  The cutting blade 50 has a cutting edge 53 that is angled with respect to the surface of the expanded graphite sheet 26. Therefore, the cutting blade 50 is moved in the direction close to the surface of the expanded graphite sheet 26 by the cutting drive unit 51, so that the expanded graphite sheet piece 7 is prepared as described above. The expanded graphite sheet 26 can be sequentially cut in an inclined manner from one end side to the other end side in the width direction.

  The guide supply mechanism 34 includes a funnel 55. The funnel 55 has a large-diameter upper opening 56 and a smaller-diameter lower opening 57. The funnel 55 has the upper opening 56 opened upward and the lower opening 57 so that the expanded graphite sheet piece 7 formed by the cutting mechanism 33 can be guided to the upper opening 56. Is provided below the pedestal 52 in a state where is opened downward.

  The knitting machine 35 is configured so that the tubular member 6 can be formed by knitting the wire 13. The knitting machine 35 continues knit knitting of the wire 13 so that the opening of the tubular member 6 is held at a position facing the lower opening 57 of the funnel 55, and the tubular portion (the tubular member) The cylindrical member 6 having a predetermined length in the axial direction is formed by feeding it downward while forming a part of 6).

  In the manufacturing apparatus 30, the driving of the transport mechanism 32, the cutting mechanism 33, and the knitting machine 35 is configured to be controlled by a control device 76.

  By using the manufacturing apparatus 30 having such a configuration, a transporting process for transporting the expanded graphite sheet 26 continuously to the next cutting process is performed using the supply mechanism 31 and the transport mechanism 32. The cutting mechanism 33 is used to perform a cutting process for continuously cutting the expanded graphite sheet 26 conveyed by the conveying process so that the expanded graphite sheet piece 7 is formed. As shown in FIG. 6, the produced expanded graphite sheet piece 7 is guided and filled into the tubular member 6 by using the guide supply mechanism 34 and the knitting machine 35, and the yarn 1 Can be manufactured.

  Further, an experiment relating to gas seal characteristics was performed using an experimental apparatus 60 as shown in FIG. 7 for a packing (implemented product) configured using only the yarns 1 (16 pieces) according to the present embodiment. As a comparative example, a packing (conventional product) configured using only the conventional yarn as described above was prepared, and an experiment relating to the gas seal characteristics was also performed using the experimental device 60.

  The experimental apparatus 60 includes a packing box 62 that can accommodate a test body (packing) 61, a tightening mechanism 63 that can tighten the test body 61 incorporated in the packing box 62 with a predetermined tightening pressure, A gas supply mechanism 64 capable of applying a gas of a predetermined pressure to the test body 61 incorporated in the packing box 62, and a measurement for measuring the amount of gas leaking from the packing box 62 through the leak-off pipe 65 Device 66.

  In the experimental apparatus 60, the tightening mechanism 63 includes a hydraulic cylinder 67, a load converter 68 for measuring an axial load, a load converter 69 for measuring a tightening pressure, and the like. The gas supply mechanism 64 includes a supply device 72 that can supply gas via a pipe 71, a pressure converter 73 that can convert the pressure of the supplied gas, a heater 74, and the like. Further, a recorder 75 capable of recording the tightening pressure and gas pressure by the tightening mechanism 63 is provided.

Regarding the experimental method, first, the packing is formed in a ring shape, and six ring-shaped packings are prepared. Then, the gland packings arranged coaxially and continuously are assembled into the packing box 62 as a test body 61. Next, the clamping mechanism 63 clamps the test body 61 incorporated in the packing box 62 in the axial direction with a clamping pressure of 20 N / mm ² to maintain this clamping state.

  Next, the gas supply mechanism 64 loads nitrogen gas having a pressure of 1 Mpa onto the test body 61 that is tightened by the packing box 62. After 10 minutes from the start of the nitrogen gas load, the amount of gas leaked from the packing box 62 during this time is measured by the measuring device 66 and recorded. Thereafter, the pressure of the nitrogen gas is removed. Thus, the experiment on the gas seal characteristics is completed.

Then, the tightening pressure by the tightening mechanism 63 is set to 20 N / mm ² in the method, upon the place of 30 N / mm ^2, also, after place of 40N / mm ^2, in the same manner Further experiments were performed.

As a result, as shown in FIG. 8, it was found that the leakage amount of nitrogen gas was 0.01 cc / min or less regardless of the tightening pressure for the implemented product. The conventional leakage amount of nitrogen gas, when the pressure tightening of 20 N / mm ² is 0.1 cc / min, in the case of 30 N / mm ² is 0.05 cc / min, when the 40N / mm ² Was found to be 0.01 cc / min or less.

  From this, it was confirmed that the leakage amount of the nitrogen gas was reduced as compared with the conventional product even when the tightening pressure was relatively small. In other words, it was confirmed that the packing 2 can ensure good sealing performance.

In addition, after performing an experiment by the same method as described above after setting the tightening pressure by the tightening mechanism 63 to 100 N / mm ² , the test body is taken out from the packing box 62, and the protruding portion of the packing in the test body The overhang dimension was measured. The protruding portion protrudes in the axial direction from the inner diameter side of the end surface of the ring-shaped packing, and the protruding dimension is the protruding amount in the axial direction of the protruding portion.

  As a result, it was found that when the test body was an actual product, as shown in FIG. 9A, the maximum value of the protruding dimension d1 of the protruding portion 82 of the packing 81 was about 0.2 mm. When the test body was a conventional product, as shown in FIG. 9B, it was found that the maximum value of the protruding dimension d2 related to the protruding portion 85 of the packing 84 was about 0.6 mm.

DESCRIPTION OF SYMBOLS 1 Yarn 2 Gland packing 6 Cylindrical member 7 Expanded graphite sheet piece 11 One end part of the expanded graphite sheet piece in the longitudinal direction 12 The other end part in the longitudinal direction of the expanded graphite sheet piece 17 The tip end in the one end part in the longitudinal direction 22 The tip end in the other end part in the longitudinal direction

Claims (3)

In a packing constituted by twisting or braiding a plurality of yarns,
The tubular member is provided with a large number of elongated graphite sheet pieces formed in an elongated shape, and the expanded graphite sheet piece is loaded into the tubular member so that the expanded graphite sheet piece extends in the axial direction of the tubular member. And the yarns included in the plurality of yarns,
The expanded graphite sheet piece is formed in one end in the longitudinal direction that is tapered toward one side in the axial direction of the cylindrical member, and is formed in a tapered shape toward the other side in the axial direction of the cylindrical member. Having a longitudinal other end,
One end in the longitudinal direction of the expanded graphite sheet piece is the other end in the longitudinal direction of the other expanded graphite sheet piece located on the other axial side of the tubular member of the expanded graphite sheet piece, and the cylindrical member. It is provided so that it may oppose with respect to the radial direction of.   The packing according to claim 1, wherein the expanded graphite sheet piece includes a sharply sharp tip at each of the one end in the longitudinal direction and the other end in the longitudinal direction.   The expanded graphite sheet piece can exhibit a parallelogram shape extending along a longitudinal direction of the expanded graphite sheet piece as viewed from a direction orthogonal to the axial direction of the cylindrical member. Packing of description.

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