JP6246092B2 - Manufacturing method of gasket - Google Patents

Description

  The present invention relates to a method for manufacturing a gasket.

  Conventionally, a gasket configured using a metal mesh material and expanded graphite is known (see, for example, Patent Document 1). This type of gasket manufacturing method generally includes a material preparation step, a composite formation step, a cylindrical body formation step, and a compression molding step.

  In the material preparation step, a metal mesh material and expanded graphite are prepared. In the composite formation step, a long strip-shaped composite in which the expanded graphite and the metal mesh material overlap is formed. In the tubular body forming step, the composite body is wound in a spiral shape so that a multi-winding tubular body having a short direction of the composite body as an axial direction is formed.

  In the compression molding step, the cylindrical body is compression molded in the axial direction to obtain a gasket. Specifically, in a state where a fixed mold and a movable mold capable of moving forward and backward with respect to the fixed mold are used, the cylindrical body is fixed to the inner side so that the cylindrical body is fitted onto the shaft-shaped inner fixed mold. The movable mold is inserted between the mold and the outer fixed mold, and then the movable mold is pushed between the inner fixed mold and the outer fixed mold where the cylindrical body is located.

  However, in the gasket manufacturing method described above, when the compression molding step is performed, the width dimension in the axial direction of the cylindrical body is substantially constant over the entire circumference (that is, the short length of the composite body). Since the width dimension in the hand direction is substantially constant over the entire length), when an external force in the compression direction is applied to the cylindrical body (the composite body), the end (free end) is excessively deformed. The burr was easily generated in the gasket obtained after the compression molding process.

JP-A-7-113469

  The present invention has been made in view of such circumstances, and in the manufacturing method of a gasket configured using a metal mesh material and expanded graphite, the generation of burrs is prevented and molding defects are suppressed. It is an object of the present invention to provide a method for manufacturing a gasket that can be used.

  The invention according to claim 1 is a method of manufacturing a gasket configured using a metal mesh material and expanded graphite, the step of preparing the metal mesh material and the expanded graphite, and the expanded graphite is the metal mesh material A step of arranging the metal mesh material around the expanded graphite so as to form a long band-shaped composite surrounded by, and a longitudinal end portion of the composite with respect to a short direction of the composite Adjusting the shape of the longitudinal end portion of the composite so that the width dimension in the longitudinal direction of the composite is smaller than the width dimension in the composite, and the transverse direction of the composite as the axial direction And a step of winding the composite body in a spiral shape so as to form a multi-winding cylindrical body, and a step of compression-molding the cylindrical body in its axial direction.

  According to this configuration, since the end shape adjusting step is included in the gasket manufacturing method, in the compression molding step performed after the end shape adjusting step, the end portion of the cylindrical body (that is, It is possible to make it difficult for an external force in the compression direction to be applied to the end portion of the composite. Therefore, it is possible to prevent the burr from being generated in the gasket by suppressing the deformation amount of the end portion of the cylindrical body. Therefore, the molding defect of the gasket can be suppressed.

  According to a second aspect of the present invention, in the gasket manufacturing method according to the first aspect, the composite body is formed so that a width dimension in a radial direction of the cylindrical body is substantially constant over the entire circumference of the cylindrical body. It is wound in a spiral shape.

  According to this structure, regarding the gasket obtained after the compression molding step, the density and the width dimension in the axial direction can be made substantially uniform over the entire circumference. Therefore, stable molding can be performed.

  According to the present invention, in a method for manufacturing a gasket configured using a metal mesh material and expanded graphite, a method for manufacturing a gasket that can easily prevent the occurrence of burrs and can suppress molding defects is provided. Can do.

It is sectional drawing which shows the state at the time of use of the gasket manufactured using the manufacturing method of the gasket which concerns on one Embodiment of this invention. It is a front view of the gasket of FIG. It is a figure which shows the flow of the manufacturing method of the gasket which concerns on one Embodiment of this invention. (A) is a figure which shows the state of the composite_body | complex formation process in the manufacturing method of the gasket which concerns on one Embodiment of this invention. (B) is AA arrow sectional drawing of (a). It is a front view of the composite_body | complex obtained after execution of the composite planarization process in the manufacturing method of the gasket which concerns on one Embodiment of this invention. It is a front view of the composite_body | complex obtained after execution of the edge part shape adjustment process in the manufacturing method of the gasket which concerns on one Embodiment of this invention. (A) is a front view of the composite of another example obtained after execution of the edge part shape adjustment process in the manufacturing method of the gasket which concerns on one Embodiment of this invention. (B) is a front view of the composite body of another example obtained after execution of the edge part shape adjustment process in the manufacturing method of the gasket which concerns on one Embodiment of this invention. (C) is a front view of the composite of another example obtained after execution of the end shape adjustment step in the gasket manufacturing method according to one embodiment of the present invention. (A) is a front view of the composite of another example obtained after execution of the edge part shape adjustment process in the manufacturing method of the gasket which concerns on one Embodiment of this invention. (B) is a front view of the composite body of another example obtained after execution of the edge part shape adjustment process in the manufacturing method of the gasket which concerns on one Embodiment of this invention. (A) is a front view of the composite of another example obtained after execution of the edge part shape adjustment process in the manufacturing method of the gasket which concerns on one Embodiment of this invention. (B) is a front view of the composite body of another example obtained after execution of the edge part shape adjustment process in the manufacturing method of the gasket which concerns on one Embodiment of this invention. (C) is a front view of the composite of another example obtained after execution of the end shape adjustment step in the gasket manufacturing method according to one embodiment of the present invention. It is a figure which shows the state of the cylindrical body formation process in the manufacturing method of the gasket which concerns on one Embodiment of this invention. It is a figure which shows the state of the compression molding process in the manufacturing method of the gasket which concerns on one Embodiment of this invention. It is sectional drawing which shows the state at the time of use of the gasket of another example manufactured using the manufacturing method of the gasket which concerns on one Embodiment of this invention. It is a front view of the gasket of FIG. It is side surface sectional drawing of the gasket of FIG.

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

  FIG. 1 shows a state in use of a gasket 1 which is an example of a gasket manufactured using a gasket manufacturing method according to an embodiment of the present invention. FIG. 2 shows a front view of the gasket 1.

  As shown in FIG. 1, the gasket 1 is used, for example, at a joint portion of a first pipe 3 and a second pipe 4. When the gasket 1 is used for the joint portion, the gasket 1 is connected to the first pipe 3 and the end of the second pipe 4 in order to seal between the end of the first pipe 3 and the end of the second pipe 4. It is interposed between the second pipes 4.

  As shown in FIGS. 1 and 2, the gasket 1 is formed in an annular shape having a diameter corresponding to the first pipe 3 and the second pipe 4, and an end portion of the first pipe 3 is used when the gasket 1 is used. It is comprised so that it may be pinched between the cyclic | annular 1st contact part 5 with which it was equipped, and the cyclic | annular 2nd contact part 6 with which the edge part of the said 2nd piping 4 was equipped.

  Specifically, the gasket 1 is configured using a metal mesh material and expanded graphite by the gasket manufacturing method. The gasket 1 is formed so that the metal wire constituting the metal mesh material and the expanded graphite are mixed together. The method for manufacturing the gasket will be described later.

  The gasket 1 includes a seal portion for preventing leakage of fluid from the flow path 7 in the first pipe 3 and the second pipe 4 connected to each other. In the gasket 1, as shown in FIGS. 1 and 2, a first seal part 11 and a second seal part 12 are provided as the seal part.

  The first seal portion 11 is pressed against the first contact portion 5 when the gasket 1 is sandwiched between the first contact portion 5 and the second contact portion 6. It comes to come in pressure contact. At this time, the second seal portion 12 is pressed against the second contact portion 6 so as to come into pressure contact with the second contact portion 6.

  Thus, according to the gasket 1, when the gasket 1 is interposed between the first pipe 3 and the second pipe 4, the first seal portion 11 and the first pipe 3 (the first pipe 3) The sealability can be ensured between the contact portion 5) and the sealability can be ensured between the second seal portion 12 and the second pipe 4 (second contact portion 6). It is like that.

  Next, a method for manufacturing the gasket according to the present embodiment used for manufacturing the gasket 1 will be described.

  FIG. 3 shows the flow of the gasket manufacturing method. As shown in FIG. 3, the gasket manufacturing method includes a material preparation step S1, a composite formation step S2, an end shape adjustment step S4, a cylindrical body formation step S5, and a compression molding step S6. included. In the present embodiment, the gasket manufacturing method further includes a complex flattening step S3 that is advanced after the complex forming step S2.

  In the material preparation step S1, a metal mesh material 21 and an expanded graphite tape 22 as shown in FIGS. 4 (a) and 4 (b) are prepared. In the present embodiment, the metal mesh material 21 is formed by a metal wire 23 being knitted by a predetermined knitting method such as knit knitting, and is formed in a horizontally long cylindrical shape whose longitudinal direction is the axial direction (vertical direction). Has been.

  As the metal wire 23, a metal wire having a predetermined wire diameter (thickness) is employed. For example, the metal wire 23 is a stainless steel wire having a diameter of about 0.1 to 0.3 mm (preferably 0.15 mm).

  The expanded graphite tape 22 has a width dimension comparable to the width dimension of the metal mesh material 21 in the longitudinal direction. The expanded graphite tape 22 has a predetermined width dimension in the short direction and a predetermined thickness dimension in the thickness direction so that the expanded graphite tape 22 can be inserted into the cylindrical metal mesh material 21. .

  The expanded graphite as a material to be prepared in the material preparation step S1 is expanded graphite (expanded graphite tape) formed in a tape shape as shown in FIG. Further, it may be expanded graphite cut into strips or lines (thin width), or may be granular expanded graphite.

  In the composite formation step S2, the elongated strip-shaped composite 24 (see FIG. 5) in which the expanded graphite tape 22 is surrounded by the metal mesh material 21 is formed, as shown in FIGS. As shown in b), the metal mesh material 21 is arranged around the expanded graphite tape 22.

  In the present embodiment, the expanded graphite tape 22 is inserted into the cylindrical metal mesh material 21 over almost the entire width in the lateral direction, and both end surfaces in the longitudinal direction are aligned with both end surfaces in the longitudinal direction of the metal mesh material 21. Thus, the metal mesh material 21 is moved along the axial direction.

  In the complex flattening step S3, the complex 24 is formed flat. As a result, the composite 24 has a flat, long rectangular shape that is attached so that the metal wire 23 of the metal mesh material 21 is in close contact with the surface of the expanded graphite tape 22.

  In the end portion shape adjustment step S4, as shown in FIG. 6, the width dimension at the end portion 25 in the longitudinal direction (Y direction) of the composite 24 is the width direction in the short direction (X direction) of the composite 24. The shape of the longitudinal end portion 25 of the composite 24 is adjusted so as to be smaller than the width dimension at the midway portion 26 in the longitudinal direction of the composite 24.

  Here, the longitudinal end portion 25 of the composite 24 has a width dimension in the short direction at the end face and in the vicinity thereof of 3/4 of the width dimension in the short direction of the longitudinal intermediate portion 26 (preferably, 1/2) It is formed in an appropriate shape so as to be less than or equal to

  In this embodiment, since the composite 24 has a long rectangular shape, one of the two corners of each end 25A and 25B in the longitudinal direction of the composite 24 is in the longitudinal direction. On the other hand, a part of each of the end portions 25A and 25B is cut out by cutting along a cut surface 27A extending obliquely in a straight line.

  Each of the end portions 25A and 25B adjusted in the end shape adjusting step S4 is smaller as the width dimension in the short direction of the composite body 24 has a predetermined width from the longitudinal middle portion 26 side toward each end surface. It is assumed that it is formed in such a tapered shape. The end portions 25A and 25B are point-symmetric with respect to the center 28 of the composite 24.

  In the end shape adjusting step S4, the cut surface of the end portion 25 is a cut surface 27B having a gentler inclination angle than the cut surface 27A in the present embodiment, as shown in FIG. 7A. In addition, the end shape may be adjusted. The end shape is adjusted so that the cut surface of the end portion 25 becomes the cut surfaces 27C and 27D that are bent once (or a plurality of times) in the middle as shown in FIGS. 7B and 7C. Also good.

  In the end shape adjusting step S4, the end shape is such that the cut surfaces of the end portions 25 become the cut surfaces 27E and 27F having a predetermined inclination angle located on both sides in the short direction as shown in FIG. May be adjusted. Even if the end shape of the end portion is adjusted so that the cut surface of the end portion 25 becomes a cut surface 27G formed in a concave shape in the middle in the short direction as shown in FIG. Good.

  Further, in the end shape adjustment step S4, in consideration of productivity and yield, the one end portion 25A and the other end portion 25B should have different shapes (convex shape and concave shape) corresponding to each other. As shown in FIG. 9B, the cut surfaces of the end portions 25A and 25B are cut surfaces 27H and 27J and cut surfaces 27K and 27L, respectively, as shown in FIG. 9A. The end shape may be adjusted to be 27M and the cut surface 27N, or to be the cut surface 27P and the cut surface 27Q as shown in FIG. 9C.

  In the cylindrical body forming step S5, as shown in FIG. 10, one end is formed so that a spirally wound cylindrical body 30 in a multiple winding state in which the short side direction of the composite 24 is the axial direction is formed. The composite 24 is spirally wound with the portion 25A positioned on the outer peripheral side and the other end 25B positioned on the inner peripheral side. The number of windings at this time is appropriately set according to the required thickness for the gasket 1 to be manufactured.

  In the compression molding step S6, the spirally wound tubular body 30 is compression molded in the axial direction. In the present embodiment, as shown in FIG. 11, the compression molding step S <b> 6 is performed using a fixed mold 31 corresponding to the shape of the gasket 1 and a movable mold 32 that can move forward and backward with respect to the fixed mold 31. To do.

  That is, first, the spirally wound tubular body 30 is installed between the inner fixed mold 33 and the outer fixed mold 34 while being externally fitted to the inner fixed mold 33 in the fixed mold 31. Then, the movable mold 32 is moved in the direction of the arrow 36 and pushed between the inner fixed mold 33 and the outer fixed mold 34. Thus, the spiral wound cylindrical body 30 is compression molded in the axial direction and the radial direction.

  And in the manufacturing method of the said gasket, the said gasket 1 can be obtained now by completion | finish of the said compression molding process S6.

  Thus, the manufacturing method of the gasket according to the present embodiment includes the end shape adjusting step S4. Therefore, in the compression molding step S6 executed after the end shape adjusting step S4, the end of the spirally wound tubular body 30 (that is, the end 25 of the composite 24) is compressed by the movable mold 32. It is possible to make it difficult to apply an external force (in the direction of the arrow 36).

  Therefore, in the compression molding step S6, the end of the spirally wound tubular body 30 (particularly, the metal wire 23) is excessively deformed (extruding into the gap or the like existing in the fixed mold 31 to cause biting). It is possible to prevent burrs from being generated in the gasket 1. Therefore, it is possible to suppress molding defects of the gasket 1 when the above-described manufacturing method is used.

  In the present embodiment, at the time of execution of the cylindrical body forming step S5, the width dimension in the radial direction of the spirally wound tubular body 30 is substantially constant over the entire circumference of the spirally wound tubular body 30. The composite 24 is wound in a spiral shape. That is, in the spiral wound cylindrical body 30, the number of the composite bodies 24 juxtaposed in the radial direction is substantially the same at any position in the circumferential direction.

  Thereby, regarding the said gasket 1 obtained after the said compression molding process S6, a density and the width dimension of an axial center direction can be made substantially uniform over the perimeter. Therefore, when the gasket manufacturing method according to the present embodiment is used, stable molding can be performed.

  Further, the gasket manufacturing method according to the present embodiment is not used only for manufacturing the gasket 1. For example, the gasket 51 as described below can be obtained by making a partial change in the compression molding process. It can also be used for manufacturing.

  That is, the gasket 51 can be used, for example, at a joint portion of the first pipe 53 and the second pipe 54 as shown in FIG. 12, and is fitted on the end of the first pipe 53 when used. So as to be sandwiched between the annular first contact portion 55 provided at the end thereof and the annular second contact portion 56 provided at the end of the second pipe 54. It is configured.

  The gasket 51 includes a seal portion for preventing leakage of fluid from the flow path 57 in the first pipe 53 and the second pipe 54 connected to each other. In the gasket 51, as shown in FIGS. 12, 13, and 14, a first seal portion 61 and a second seal portion 62 are provided as the seal portion.

  The first seal portion 61 is provided at one end of the gasket 51 in the axial direction, and is disposed on the radially outer side of the gasket 51. The first seal portion 61 has a first seal surface 63 that tapers toward one end surface 64 in the axial direction of the gasket 51. The first seal portion 61 is configured to be able to contact the first contact portion 55 (specifically, the inclined opposing surface 58) at the first seal surface 63.

  The first seal surface 63 is disposed between the one axial end surface 64 disposed to face the first contact portion 55 and the outer peripheral surface 65 of the gasket 51. In the gasket 51, the first seal surface 63 is tapered so that the diameter gradually decreases from the outer peripheral surface 65 (center of the gasket 51 in the axial direction) toward the axial end surface 64. Is formed.

  The first seal surface 63 has a connecting portion 67 connected to the axial end surface 64 extending linearly in the radial direction in a cross section including the axial center 66 of the gasket 51. It is formed so as to exhibit a curved shape (R shape) that is convex toward one side and radially outward.

  And the said gasket 51 is pinched | interposed between the said 1st contact part 55 and the said 2nd contact part 56 which adjoins the axial center direction, and is used for the joint part of the said 1st piping 53 and the said 2nd piping 54. At this time, the first seal portion 61 is pressed against the first contact portion 55 so as to be compressed and deformed so that the first seal portion 63 comes into pressure contact with the first contact portion 55 (the facing surface 58). It has become.

  On the other hand, the second seal portion 62 is provided at the other axial end portion of the gasket 51 and is disposed on the radially outer side of the gasket 51. The second seal portion 62 has a second seal surface 68 that tapers toward the other axial end surface 69 of the gasket 51. The second seal portion 62 is configured to be able to contact the second contact portion 56 (specifically, the inclined opposing surface 59) at the second seal surface 68.

  The second seal surface 68 is disposed between the other axial end surface 69 that is disposed to face the second contact portion 56 and the outer peripheral surface 65 of the gasket 51. The second seal surface 68 is tapered in the gasket 51 so that the diameter gradually decreases from the outer peripheral surface 65 (center of the gasket 51 in the axial direction) toward the other end surface 69 in the axial direction. Is formed.

  In the cross section including the axis 66 of the gasket 51, the second seal surface 68 has a connecting portion 70 connected to the other axial end surface 69 extending linearly in the radial direction in the axial direction of the gasket 51. On the other side, it is formed so as to exhibit a curved shape (R shape) that protrudes radially outward.

  When the gasket 51 is used for a joint portion of the first pipe 53 and the second pipe 54, the second seal part 62 is pressed against the second contact part 56 so as to be compressed and deformed. The second seal surface 68 is in pressure contact with the second contact portion 56 (the facing surface 59).

  With such a configuration, when the gasket 51 is used, the gasket 51 can be clamped between the first contact portion 55 and the second contact portion 56, and the first seal portion 61 can be Contact surface pressure when the first seal surface 63 contacts the first contact portion 55, and contact surface when the second seal portion 62 contacts the second contact portion 56 with the second seal surface 68. The pressure can be increased.

  Therefore, according to the gasket 51, a high seal is reliably ensured between the first contact portion 55 (the end portion of the first pipe 53) and the second contact portion 56 (the end portion of the second pipe 54). Sex can be secured.

  Further, in the gasket 51, as shown in FIGS. 13 and 14, the first seal portion 61 protrudes toward the outside of the gasket 51 with respect to the first seal surface 63. It has further. The first seal portion 61 is configured to exhibit a sealing function using the first seal surface 63 and the first projecting portion 71.

  Specifically, the first protrusion 71 is disposed between the first seal surface 63 and the outer peripheral surface 65 of the gasket 51. The first projecting portion 71 is formed in a pointed shape so as to project radially outward from the first seal surface 63 and project from the outer peripheral surface 65 in one axial direction.

  When the gasket 51 is used, the first seal portion 61 presses the first projecting portion 71 from the pointed end side to the first contact portion 55 (the opposed surface 58) earlier than the first seal surface 63. Thus, while the first projecting portion 71 is being crushed, the first seal surface 63 and the first projecting portion 71 are in pressure contact with the first contact portion 55.

  With such a configuration, in order to exert a sealing function, the first seal portion 61 is brought into contact with the first contact portion 55 (the opposed surface 58) with the first seal surface 63, and at the same time, is deformed to be crushed. The first projecting portion 71 can be brought into contact with each other, and the first seal portion 61 can be brought into contact with the first contact portion 55 with a high contact surface pressure. Therefore, the sealing performance of the first seal portion 61 can be improved.

  Further, in the gasket 51, as shown in FIG. 14, the second seal portion 62 further has a second projecting portion 72 that projects toward the outside of the gasket 51 with respect to the second seal surface 68. doing. The second protrusion 72 is configured to exhibit a sealing function using the second seal surface 68 and the second protrusion 72.

  Specifically, the second protrusion 72 is disposed between the second seal surface 68 and the outer peripheral surface 65 of the gasket 51. The second projecting portion 72 is formed in a pointed shape so as to project radially outward from the second seal surface 68 and project from the outer peripheral surface 65 to the other axial direction.

  Then, when the gasket 51 is used, the second seal portion 62 presses the second projecting portion 72 against the second contact portion 56 (the opposed surface 59) earlier than the second seal surface 68 from the pointed end side. Thus, while the second projecting portion 72 is crushed, the second seal surface 68 and the second projecting portion 72 are in pressure contact with the second contact portion 56.

  With this configuration, the second seal portion 62 is brought into contact with the second contact portion 56 (the opposed surface 59) with the second seal surface 68 and is deformed to be crushed in order to exert a sealing function. The second projecting portion 72 can be brought into contact with each other, and the second seal portion 62 can be brought into contact with the second contact portion 56 with a high contact surface pressure. Therefore, the sealing performance of the second seal portion 62 can be improved.

  In the gasket 51, as shown in FIGS. 13 and 14, a first chamfered portion 76 is formed between one axial end surface 64 of the gasket 51 and the inner peripheral surface 75 of the gasket 51. Yes. The first chamfered portion 76 has an inclined surface that gradually increases in diameter from the inner peripheral surface 75 side toward the one axial end surface 64, and is provided over the entire circumference of the gasket 51.

  In the gasket 51, as shown in FIG. 14, a second chamfered portion 77 is formed between the other axial end surface 69 of the gasket 51 and the inner peripheral surface 75 of the gasket 51. The second chamfered portion 77 has an inclined surface that gradually increases in diameter from the inner peripheral surface 75 side toward the other axial end surface 69, and is provided over the entire circumference of the gasket 51.

  In the gasket 51, as shown in FIG. 14, the first seal portion 61 and the second seal portion 62 are arranged with an axial center portion (the outer peripheral surface 65) of the gasket 51 interposed therebetween. It is formed in a symmetrical shape in the center direction.

  With such a configuration, when the gasket 51 is attached to the end of the first pipe 53, it becomes easy to exhibit high sealing performance regardless of the orientation of the gasket 51. Therefore, when attaching to the first pipe 53 and the second pipe 54, it is not necessary to consider the orientation of the gasket 51, so workability can be improved.

DESCRIPTION OF SYMBOLS 1 Gasket 21 Metal mesh material 22 Expanded graphite tape 24 Composite 25 (25A * 25B) Longitudinal end part of composite 26 Longitudinal midway part of composite 30 Spiral tubular body 51 Gasket S1 Material preparation process S2 Composite formation process S3 Composite flattening step S4 End shape adjusting step S5 Cylindrical body forming step S6 Compression molding step

Claims (2)

A method of manufacturing a gasket configured using a metal mesh material and expanded graphite,
Preparing the metal mesh material and the expanded graphite;
Disposing the metal mesh material around the expanded graphite such that a long band-like composite in which the expanded graphite is surrounded by the metal mesh material is formed;
With respect to the short direction of the composite, the shape of the longitudinal end of the composite is such that the width at the longitudinal end of the composite is smaller than the width at the midway of the composite. Adjusting, and
Winding the composite in a spiral shape so as to form a multi-winding cylindrical body whose axial direction is the short direction of the composite;
And a step of compression-molding the cylindrical body in the axial direction thereof.   2. The gasket production according to claim 1, wherein the composite is wound spirally so that a width dimension in a radial direction of the cylindrical body is substantially constant over an entire circumference of the cylindrical body. Method.

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