JP2011220517A - Flexible joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible joint which can be manufactured at relatively low cost, and which enables attachment and detachment of a connection flange with respect to a flexible tubular part.SOLUTION: The flexible tubular part has a tubular body, an annular seal part extending from an end of the body to the outside in the radial direction, and a tubular outer peripheral wall part bent toward the inside of the body in the axial direction from an outer peripheral end of the seal part. The connection flange is formed by folding a sheet metal so as to include a tubular inner peripheral plate part fitted onto an outer peripheral edge part of an end of the body, an annular receiving plate which is formed on the backside of the seal part and which constitutes a receiving surface of the seal part, and a tubular plate part fitted into the outer peripheral wall part. An annular bead wire is buried inside the outer peripheral wall part of the flexible tubular part so as to fasten the tubular plate part of the connection flange.

Description

  The present invention relates to a flexible joint (flexible pipe joint) that allows relative displacement of connected pipes due to an earthquake or the like.

  Conventionally, a flexible joint connected to piping such as an air conditioner or water supply is known. The flexible joint includes a flexible cylindrical portion having flexibility and connecting flanges provided at both ends in the axial direction of the flexible cylindrical portion. The flexible cylindrical portion is made of a rubber material having a certain degree of flexibility, and a plurality of braided reinforcing cloths are embedded in the flexible cylindrical portion. As a result, the flexible joint is given two characteristics: a certain degree of flexibility that follows the relative displacement of the pair of connected pipes, and a certain degree of rigidity that resists the water pressure in the flexible cylindrical portion. Has been.

  As this type of flexible joint, for example, Patent Document 1 discloses a structure in which a reinforcing ring is embedded in an opening end portion of a flexible cylindrical portion (so-called solid ring system). In this flexible joint, for example, as shown in FIG. 7, a metal connection flange 103 is integrally vulcanized and bonded to the outer peripheral edge portion 102 at the end of the flexible cylindrical portion 101. As a result, the so-called neck drop that the connecting flange 103 is detached from the flexible tube portion 101 is prevented. Further, in this flexible joint, an annular metal reinforcing ring 105 (solid ring) is embedded in the seal portion 104 facing the mating flange (phase flange). As a result, the tightening force acting on the seal portion 104 at the time of connection with the pipe to be connected is increased, thereby improving the sealing performance.

JP 2002-323187 A

  In the so-called solid ring type flexible joint as disclosed in Patent Document 1, the flexible cylindrical portion, the connecting flange, and the reinforcing ring are integrally formed, which complicates the manufacturing process and reduces the manufacturing cost. Also gets higher. In addition, in the structure in which the flexible tube portion and the connecting flange are integrally formed, for example, when the flexible tube portion needs to be replaced due to deterioration of the flexible tube portion or manufacturing failure, a new flexibility It is necessary to integrally form the tube portion together with the connecting flange, which increases the time and cost required for component replacement.

  The present invention has been made in view of such problems, and a purpose thereof is a flexible joint in which a manufacturing flange is relatively low and a connecting flange can be attached to and detached from a flexible cylindrical portion. Is to provide.

  In order to achieve the above object, in the flexible joint according to the present invention, a connection flange including an inner peripheral plate portion, a receiving plate portion, and a cylindrical plate portion is formed by folding back a sheet metal, and the receiving of the connecting flange is performed. By receiving the seal portion at the plate portion, the connecting flange can be attached to and detached from the flexible tube portion while reducing the manufacturing cost.

  That is, the first invention is directed to a flexible joint including a flexible cylindrical portion having flexibility and connecting flanges respectively connected to both axial ends of the flexible cylindrical portion. The flexible cylindrical portion includes a cylindrical main body portion, an annular seal portion that extends radially outward from an axial end portion of the main body portion to form a sealing surface for the companion flange on the surface, and the seal portion A cylindrical outer peripheral wall portion that bends inward from the outer peripheral end portion in the axial direction of the main body portion, and the connection flange is formed by folding back a sheet metal and is externally fitted to the axial edge portion of the main body portion. A cylindrical inner peripheral plate portion, an annular receiving plate portion which is formed on the back side of the seal portion and forms a receiving surface of the seal portion, and a cylindrical plate portion fitted into the outer peripheral wall portion; An annular bead wire is embedded in the outer peripheral wall portion of the flexible tube portion.

  In the first invention, the connection flange is formed by folding the sheet metal. Thereby, compared with the flange shape | molded, for example, the flange for a connection becomes easy to process, and thickness reduction and weight reduction are achieved.

  The receiving plate portion of the connecting flange is formed on the back side of the seal portion of the flexible tube portion to form the receiving surface of the seal portion. When the connection flange and the phase flange opposite to the connection flange are connected, the deformation of the seal portion is restricted by the receiving surface of the receiving plate portion. Thereby, even if a certain amount of tightening force acts on the seal portion, the sealability of the seal portion can be sufficiently ensured. That is, in the connecting flange of the present invention, the receiving plate portion formed by folding back the sheet metal functions in the same manner as the solid ring type reinforcing ring of the conventional example.

  In addition, since the inner peripheral plate portion of the connecting flange is externally fitted to the outer peripheral edge portion of the end portion of the main body portion and the cylindrical plate portion of the connecting flange is internally fitted to the outer peripheral wall portion, the flexible cylinder is provided. Even if the portion and the connecting flange are not integrally formed, the connecting flange can be held by the flexible tube portion. With this fitting structure, the connecting flange can be attached to and detached from the flexible cylindrical portion.

  Further, a bead wire is embedded in the outer peripheral wall portion of the flexible cylindrical portion so as to tighten the cylindrical plate portion of the connecting flange. Thereby, while a deformation | transformation of an outer peripheral wall part is blocked | prevented by a bead wire, the close_contact | adherence degree between an outer peripheral wall part and the cylindrical board part fitted in this outer peripheral wall part increases. Therefore, the so-called neck drop that the connecting flange is detached from the flexible tube portion is also suppressed.

  Moreover, a bead wire is embed | buried under the outer peripheral wall part located in a radial direction outer side rather than a seal | sticker part. Thereby, even if the seal portion is compressed in the axial direction when the flange is connected, the stress generated in the buried portion of the bead wire becomes relatively small. Therefore, stress concentration in the buried portion can be alleviated, and breakage of this portion, generation of cracks, etc. can be avoided.

  It is preferable that the receiving surface of the receiving plate portion of the connecting flange is formed in an annular plane shape (second invention).

  When the receiving surface has a planar shape, deformation of the seal portion can be effectively prevented and stress generated in the seal portion can be dispersed when the flange is connected. Thereby, in a seal part, what is called a surface seal whose pressure receiving area is wider than what is called a line seal can be formed, seal pressure is stabilized and seal performance further improves.

  It is preferable that a space is formed on the outer peripheral side of the outer peripheral wall portion of the flexible cylindrical portion (third invention).

  If a space is formed on the outer peripheral side of the outer peripheral wall portion and the outer peripheral wall portion is not restricted from the outer peripheral side, the stress generated in the buried portion of the bead wire can be further reduced. Specifically, when the seal portion is compressed when the flange is connected, stress is generated in the outer peripheral wall portion. At this time, if a space is formed on the outer peripheral side of the outer peripheral wall portion, the outer peripheral wall portion is deformed into the outer peripheral side space so as to relieve such stress. That is, the space on the outer peripheral side of the outer peripheral wall portion functions as a clearance space for the outer peripheral wall portion for avoiding stress concentration in the buried portion of the bead wire. Thereby, generation | occurrence | production of the fracture | rupture of a buried part of a bead wire and a crack can be avoided.

  The connecting flange preferably further includes an annular fastening plate portion that extends radially outward from the axially inner end portion of the cylindrical plate portion and that has a plurality of bolt holes (fourth invention).

  Accordingly, the bolt can be inserted into the bolt hole of the fastening plate portion, and the connecting flange and the companion flange can be fastened to each other by the bolt / nut.

  The cylindrical plate portion of the connecting flange is formed with a diameter-enlarging cylindrical portion that expands radially outward as it goes inward in the axial direction of the main body portion, and the fastening plate portion is expanded. It extends from the axially inner end of the diameter tube portion to the outside in the diameter direction, and a tapered portion is formed on the outer peripheral wall portion of the flexible tube portion so that the expanded diameter tube portion is fitted inside. Preferred (5th invention).

  Thereby, in the flange for connection, in the site | part in which an enlarged diameter cylinder part is formed, the distance from the fastening site | part of a volt | bolt to a cylindrical board part becomes short, and it can improve the intensity | strength of a flange for connection. As a result, at the time of fastening the bolt, it is possible to avoid the connection portion between the cylindrical plate portion and the fastening plate portion from bending in the bolt fastening direction.

  The connecting flange includes an outer peripheral plate portion that is bent from the outer peripheral end portion of the fastening plate portion toward the axially outer side of the flexible cylindrical portion, and a contact surface that contacts the companion flange is provided at a distal end surface of the outer peripheral plate portion. It is good to form (sixth invention).

  As a result, when the connection flange and the companion flange are connected, the tip of the outer peripheral plate portion functions as a stopper for the companion flange. Thereby, at the time of connection of both flanges, the bending deformation of the connection flange can be prevented.

  In particular, the distal end surface of the outer peripheral plate portion is preferably positioned between the receiving surface of the receiving plate portion and the surface of the seal portion in the axial direction of the main body portion (seventh invention).

  Thereby, the clamping force between the connecting flange and the companion flange can be optimally managed. Specifically, both the flanges are tightened, and the tightening operation is completed in a state where the companion flange is in surface contact with the front end surface of the outer peripheral plate portion. In this state, the companion flange is located closer to the backing plate than the surface of the sealing portion before tightening, and a predetermined distance from the backing plate is secured, so that an appropriate tightening force is applied to the sealing portion. Can do. Thereby, insufficient compression and excessive compression of the seal portion can be prevented, and desired sealing performance can be ensured.

  It is preferable that the outer peripheral wall portion of the flexible cylindrical portion extends inward in the axial direction of the main body portion so as to contact the fastening plate portion, and the bead wire is embedded inside the distal end portion of the outer peripheral wall portion. (Eighth invention).

  Thereby, since the axial direction length of an outer peripheral wall part can be ensured to the maximum, the frictional resistance between an outer peripheral wall part and the cylindrical plate part of a connecting flange can be increased, and necking of the connecting flange can be prevented. . Moreover, by embedding the bead wire in the distal end portion of the outer peripheral wall portion, the outer peripheral wall portion can be tightened from the distal end side toward the cylindrical plate portion. As a result, the outer peripheral wall portion and the cylindrical plate portion are more firmly fitted, so that the neck of the connecting flange can be effectively avoided.

  In addition, when a bead wire is embedded at the tip of the outer peripheral wall portion, a distance from the seal portion compressed when the flange is connected to the bead wire can be obtained. Thereby, in an outer peripheral wall part, the stress which acts on the embed | buried part of a bead wire can be reduced, and generation | occurrence | production of the fracture | rupture of this part and a crack can be prevented.

  The diameter of the bead wire is preferably set longer than the axial distance between the receiving plate portion and the companion flange when the connection flange and the companion flange are connected (the ninth invention).

  Thereby, for example, due to the relative displacement of the connected pipe, the bead wire does not pass between the companion flange and the connecting flange and come out radially inward. Therefore, it is possible to more reliably prevent the neck of the connecting flange from coming off.

  As described above, according to the flexible joint according to the present invention, since the connection flange is formed by folding the sheet metal, the connection flange is reduced in weight and thickness, and the manufacturing cost of the connection flange is reduced. it can.

  Further, since the receiving flange portion corresponding to the solid ring type reinforcing ring is formed on the connecting flange, the sealing performance of the sealing portion can be improved without increasing the number of parts.

  In addition, since the inner peripheral plate portion and the cylindrical plate portion are formed on the connection flange and the connection flange and the flexible tube portion are fitted to each other, the connection flange can be easily attached to the flexible tube portion. Can be attached and detached. Therefore, for example, the flexible cylindrical portion and the corresponding connecting flange can be mass-produced separately. In addition, since only the corresponding parts need to be replaced when replacing the flexible tube portion or the connecting flange, the time and cost required for the replacement can be reduced. In addition, since the bead wire is embedded in the outer peripheral wall portion of the flexible cylindrical portion and the outer peripheral wall portion is fastened to the cylindrical plate portion of the connecting flange, the neck of the connecting flange can also be prevented.

Drawing 1 is a side view showing the whole flexible joint concerning an embodiment, and shows a longitudinal section in part. FIG. 2 is a plan view of the flexible joint as viewed from the outside in the axial direction. FIG. 3 is an enlarged longitudinal sectional view of the vicinity of the connecting flange. FIG. 4 is an enlarged longitudinal sectional view of the vicinity of the connecting flange, and shows a state in which the companion flange is fastened. FIG. 5 is an enlarged longitudinal sectional view of the vicinity of the connecting flange in the flexible joint according to the first modification. FIG. 6 is an enlarged longitudinal sectional view of the vicinity of the connecting flange in the flexible joint according to the second modification. FIG. 7 is a longitudinal sectional view of an essential part of a conventional solid ring type flexible joint.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following embodiments are essentially preferable examples, and are not intended to limit the scope of the present invention, its application, or its use.

  FIG. 1 shows a flexible joint 10 according to an embodiment of the present invention. The flexible joint 10 uses a pipe for water supply or a pipe for air conditioning as a connected pipe, and is used as a vibration-proof joint for such a connected pipe.

  The flexible joint 10 includes a flexible tubular portion 20 having flexibility, a reinforcing portion 30 provided on the surface of the flexible tubular portion 20, and a pair provided at both axial ends of the flexible tubular portion 20. Connecting flanges 40, 40 and a pair of bead wires 50 for fastening the connecting flange 40 to the flexible cylindrical portion 20.

  The flexible cylinder portion 20 is made of a rubber material having stretchability or flexibility. The flexible cylindrical portion 20 of the present embodiment is made of synthetic rubber excellent in chlorine resistance / ozone resistance in consideration of deterioration over time due to the influence of a fluid (for example, tap water) flowing through the flexible cylindrical portion 20.

  The flexible cylinder part 20 has a main body part 21 that forms a cylindrical body part. The main body portion 21 is formed with right circular openings 21b and 21b at both ends in the axial direction, and an internal space S through which a fluid flows is formed between the openings 21b.

  A bulging portion 21 a that bulges in a substantially spherical shape toward the radially outer side is formed at an intermediate portion in the axial direction of the main body portion 21. The bulging portion 21a inflates a hollow sphere-shaped mold (such as an air bag) inside a non-added cylindrical rubber molding material, and pressurizes and deforms the body of the rubber molding material radially outward. Thereafter, this rubber molding material can be added to obtain the rubber molding material. In addition, such a shaping | molding / adding process is performed in the state which the reinforcement cloth 31 of the reinforcement part 30 affixed on the surface of the non-added rubber molding material which comprises a main-body part.

  As shown in FIGS. 1 to 3, seal portions 22 and 22 and outer peripheral wall portions 23 and 23 are formed integrally with the main body portion 21 at both axial ends of the main body portion 21 of the flexible cylindrical portion 20. The The seal portion 22 is formed in an annular shape extending radially outward from the edge portion of the opening 21 b at the axial end portion of the main body portion 21. A seal surface 22a for the companion flange 60 fastened to the connection flange 40 is formed on the surface of the seal portion 22 (the surface on the axially outer side of the main body portion 21) (see FIG. 4). The outer peripheral wall portion 23 is formed to bend from the outer peripheral end portion of the seal portion 22 toward the inner side in the axial direction of the main body portion 21 (the central portion side where the bulging portion 21a is formed in the axial direction). As a result, an annular groove that opens inward in the axial direction is formed between the outer peripheral wall portion 23 and the main body portion 21.

  In the flexible tube portion 20, an outer inclined portion 24 is formed at a connecting portion between the seal portion 22 and the outer peripheral wall portion 23, and an inner inclined portion is provided at a connecting portion between the seal portion 22 and the main body portion 21. 25 is formed. The outer inclined portion 24 forms an annular inclined surface that expands radially outward as it goes inward in the axial direction of the main body portion 21. Further, the inner inclined portion 25 forms an annular inclined surface that is reduced in diameter in the radial direction as it goes inward in the axial direction of the main body portion 21. The area of the seal surface 22a of the seal portion 22 is defined according to the location where the inclined portions 24 and 25 are formed.

  The reinforcing portion 30 of the present embodiment is composed of a single reinforcing cloth 31 formed on the surface side of the flexible cylindrical portion 20. The outer diameter of the reinforcing cloth 31 is formed in a substantially cylindrical shape, and both ends of the reinforcing cloth 31 are folded back so as to wrap the bead wires 50 and 50 and extend inward in the axial direction of the main body. The reinforcing cloth 31 is held on the surface side of the flexible cylindrical portion 20 by the flow bonding of the reinforcing cloth 31 in such a state to the flexible cylindrical portion 20. The reinforcing cloth 31 is configured by, for example, laminating a plurality of uniaxial tinted weave reinforcing cloths.

  As shown in FIGS. 1 to 4, the connecting flange 40 is provided at the axial end of the flexible cylindrical portion 20. The connecting flange 40 is fastened to the phase flange 60 on the connected pipe side via bolts 61 and nuts 62 (see FIG. 4).

  The connection flange 40 is formed of a so-called press flange that is formed by press-molding a sheet metal made of SPCC (general structural rolled steel). In this way, by forming the connecting flange 40 by press working, it is possible to reduce the processing cost of the flange as compared with, for example, a steel flange formed by casting, and to further reduce the thickness and weight of the flange. be able to.

  In the connecting flange 40, in order from the radially inner side to the radially outer side, an inner peripheral plate portion 41, a receiving plate portion 42, an intermediate plate portion (tubular plate portion) 43, a fastening plate portion 44, and an outer peripheral plate portion. 45 is continuously formed.

  The inner peripheral plate portion 41 is externally fitted to the outer peripheral edge portion (the neck portion 21c shown in FIG. 3) of the end portion of the main body portion 21 of the flexible tube portion 20. Between the inner peripheral plate portion 41 and the neck portion 21c, the main body layer 31a of the reinforcing cloth 31 and the folded layer 31b are laminated and sandwiched. The receiving plate portion 42 is formed in an annular shape that extends radially outward from the axially outer end portion of the inner peripheral plate portion 41. The receiving plate portion 42 is formed on the back side of the seal portion 22, and the receiving surface 42 a of the seal portion 22 is formed on the surface of the receiving plate portion 42 (surface facing the seal portion side). The intermediate plate portion 43 is bent inward in the axial direction from the outer peripheral end portion of the receiving plate portion 42 and is fitted into the outer peripheral wall portion 23.

  As described above, in the connecting flange 40, the inner peripheral plate portion 41, the receiving plate portion 42, and the intermediate plate portion 43 constitute an annular ridge that protrudes outward in the axial direction. The flange 40 for connection is hold | maintained at the flexible cylinder part 20 because this protruding item | line fits in the annular groove inside the outer peripheral wall part 23. FIG. With such a fitting structure, the connecting flange 40 can be attached to and detached from the flexible cylindrical portion 20.

  Further, by forming the receiving surface 42a on the back side of the seal portion 22, deformation of the seal portion 22 can be prevented by the surface 42a when the flanges 40 and 60 are connected. Thereby, even if a certain amount of tightening force is applied to the seal portion 22, the sealing performance of the seal portion 22 can be sufficiently secured. Further, since the receiving surface 42a has an annular planar shape, the stress generated in the seal portion 22 when the flanges 40 and 60 are connected can be dispersed. Thereby, in the seal part 22, what is called a face seal can be formed, a sealing pressure can be stabilized and sealing performance can be improved.

  Further, since the receiving plate portion 42 that forms the receiving surface 42a is formed by folding the connecting flange 40, there is no need to provide a separate annular reinforcing ring as in the solid ring method, for example. That is, in this embodiment, since a part of the connecting flange 40 also serves as the receiving surface 42a, the manufacturing cost can be reduced.

  The fastening plate portion 44 is formed in an annular shape that extends radially outward from the axially inner end portion of the intermediate plate portion 43. The fastening plate portion 44 is wider in the radial direction than the receiving plate portion 42. A plurality of bolt holes 44a are arranged at equal intervals in the circumferential direction at a portion of the fastening plate portion 44 closer to the outer side in the radial direction. Bolts 61 for fastening the connecting flange 40 and the companion flange 60 are inserted through the bolt holes 44a (see FIG. 4). The bolt 61 is fastened to the nut 62 in a state where the bolt hole 44 a of the connecting flange 40 and the bolt hole 60 of the companion flange 60 are inserted.

  In the present embodiment, the distal end of the outer peripheral wall portion 23 is in contact with a portion of the fastening plate portion 44 that is closer to the inside in the radial direction. And the bead wire 50 is embed | buried inside the front-end | tip part of this outer peripheral wall part 23. FIG. The bead wire 50 is a carbon steel wire having a substantially circular cross section at right angles to the axis, and is formed in a closed loop shape surrounding the intermediate plate portion 43 of the connection flange 40. By tightening the outer peripheral wall portion 23 to the intermediate plate portion 43 side by the bead wire 50, so-called neck disengagement in which the bead wire 50 is detached from the flexible tube portion 20 is prevented.

  The bead wire 50 is provided on the outer side in the radial direction than the seal portion 22 where the tightening force acts intensively. For this reason, in the outer peripheral wall part 23, the stress which acts on the embedding site | part of the bead wire 50 can be reduced. Moreover, if the front-end | tip of the outer peripheral wall part 23 is extended to the fastening plate part 44, and the bead wire 50 is provided in the front-end | tip part of the outer peripheral wall part 23, the distance from the sealing surface 22a of the seal part 22 to the bead wire 50 will be earned. Can do. For this reason, the stress which acts on the embedding site | part of the bead wire 50 in the outer peripheral wall part 23 can further be reduced. As described above, in the outer peripheral wall portion 23, the stress concentration in the buried portion of the bead wire 50 is relaxed. For this reason, it can avoid that this part fractures | ruptures or a crack arises in this part.

  The diameter D1 of the bead wire 50 is set to about 6 mm. Moreover, the diameter D1 of the bead wire 50 of this embodiment is the receiving surface 42a (surface represented by L1 shown in FIG. 3) of the receiving plate part 42, and the surface (L2 shown in FIG. 3) of the seal part 22 when not fastened. The distance D2 is set to be shorter than the distance D2. The diameter D1 of the bead wire 50 is set longer than the axial distance D3 between the receiving plate portion 42 and the companion flange 60 when the connection flange 40 and the companion flange 60 are connected (see FIG. 4). ). Thereby, it is avoided that the bead wire 50 is detached from the connecting flange 40 when the flanges 40 and 60 are connected.

  Specifically, when the diameter D1 of the bead wire 50 is made longer than the interval D3 between the receiving plate portion 42 and the companion flange 60 when the flanges 40 and 60 are fastened as shown in FIG. The bead wire 50 does not pass between the flange 60. Therefore, for example, even if the flexible joint 10 is deformed and the bead wire 50 is pulled radially inward due to an earthquake or the like, the bead wire 50 does not come out to the inside of the connecting flange 40. Accordingly, it is possible to more reliably avoid the necking of the connecting flange 40.

  The outer peripheral plate portion 45 is formed in a cylindrical shape that is bent from the radially outer end portion of the fastening plate portion 44 toward the outer side in the axial direction. The front end surface 45a (surface represented by L3 shown in FIG. 3) of the outer peripheral plate portion 45 and the receiving surface 42a (surface represented by L1 shown in FIG. 3) of the receiving plate portion 42 in the axial direction of the main body portion 21 are not tightened. It is set so as to be positioned between the surface of the seal portion 22 in a state (a surface represented by L2 shown in FIG. 3). The front end surface 45a constitutes a contact surface that contacts the phase flange 60 when the flanges 40 and 60 are connected. Thereby, since the outer peripheral plate part 45 functions as a stopper for the companion flange 60, it is possible to prevent the deformation of the connecting flange 40 when the flanges 40, 60 are connected.

  Further, by bringing the outer peripheral plate portion 45 and the companion flange 60 into contact with each other, the relative positions of the flanges 40 and 60 (that is, the tightening force of the flanges 40 and 60) can be optimally managed.

  Specifically, when the end faces of the companion flange 60 and the front end face 45a of the outer peripheral plate portion 45 are brought into surface contact when the flanges 40, 60 are fastened, the end face of the companion flange 60 is placed between the L1 and L2. 22a can be formed. Thereby, since the compression allowance of the seal part 22 is hold | maintained optimally, it can also avoid that sealing performance is impaired by the undercompression of the seal part 22, or compression too much.

  Further, the connection flange 40 of the present embodiment is folded back so as to form an annular relief space 46 on the outer peripheral side of the outer peripheral wall portion 23 of the flexible cylindrical portion 20. That is, the outer peripheral surface of the outer peripheral wall portion 23 of the present embodiment is not restrained by the connecting flange 40. Thereby, when the flanges 40 and 60 are connected, the seal portion 22 is compressed and deformed, and when the outer peripheral wall portion 23 is stressed, the outer peripheral wall portion 23 tends to be elastically deformed toward the unconstrained escape space 46 side. To do. Thereby, in the outer peripheral wall part 23, since stress concentration in the embedded part of the bead wire 50 can be more effectively alleviated, breakage of the embedded part and occurrence of cracks can be avoided.

<< Other Embodiments >>
In the above embodiment, the following configuration may be adopted.

  In the above embodiment, the escape space 46 is formed on the outer peripheral side of the outer peripheral wall portion 23. However, as in the example shown in FIG. 5 (Modification 1), a cylindrical folded plate portion 47 is also formed on the outer circumferential side of the outer circumferential wall portion 23, and the outer circumferential wall is interposed between the intermediate plate portion 43 and the folded plate portion 47. It is good also as a structure which inserts the front-end | tip part of the part 23. FIG. In this structure, the fitting of the connecting flange 40 is further strengthened, and the elastic deformation of the outer peripheral wall portion 23 can be prevented, so that the neck of the connecting flange 40 can be reliably avoided.

  In the above embodiment, the cylindrical plate portion (intermediate plate portion) 43 of the connection flange 40 extends straight from the outer peripheral end portion of the receiving plate portion 42 toward the inner side in the axial direction. That is, the cylindrical plate part 43 of the said embodiment is formed in the cylindrical shape used as a uniform diameter over an axial direction. However, as in the example shown in FIG. 6 (Modification 2), the cylindrical plate portion 43 may be expanded toward the radially outer side.

  Specifically, the cylindrical plate portion 43 in the example shown in FIG. 6 has a diameter-expanded cylindrical portion 48 extending from the middle portion to the lower end portion. The diameter-expanding cylindrical portion 48 is formed in a substantially trapezoidal cylindrical shape that expands radially outward as it goes inward in the axial direction of the flexible cylindrical portion 20. That is, in the example of FIG. 6, the diameter-enlarging cylindrical portion 48 is formed over the entire circumference in the cylindrical plate portion 43.

  On the other hand, a tapered portion 27 is formed on the outer peripheral wall portion 23 of the flexible cylindrical portion 20 so as to follow the enlarged diameter cylindrical portion 48. The taper portion 27 is formed at the lower portion of the outer peripheral wall portion 23, and forms an inclined surface that increases the inner diameter toward the inner side in the axial direction of the flexible cylindrical portion 20. A diameter-expanding cylindrical portion 48 is fitted inside the tapered portion 27.

  In the configuration shown in FIG. 6, when the connection flange 40 is fastened to the companion flange 60, the connecting portion between the cylindrical plate portion 43 and the fastening plate portion 44 is reliably prevented from being deformed in the bolt fastening direction. it can.

  Specifically, as in the above-described embodiment shown in FIG. 4, in the structure in which the cylindrical plate portion 43 extends in the axial direction and the fastening plate portion 44 is connected to the lower portion of the cylindrical plate portion 43, The distance from the lower part of the cylindrical plate part 43 to the fastening part of a bolt becomes comparatively long. For this reason, at the time of bolt tightening, the bending moment acting on the connecting portion between the cylindrical plate portion 43 and the fastening plate portion 44 tends to increase. Therefore, when the bolt tightening force becomes excessive, the connecting portion may be deformed in the bolt tightening direction.

  On the other hand, in the configuration shown in FIG. 6, the distance from the lower portion of the cylindrical plate portion 43 to the bolt fastening portion is relatively short, so that the bending moment acting on the lower portion of the cylindrical plate portion 43 is also relatively small. . As a result, it is possible to reliably prevent the connecting portion between the cylindrical plate portion 43 and the fastening plate portion 44 from being deformed when the bolt is tightened.

  Note that the diameter-enlarged cylindrical portion 48 of Modification 2 does not necessarily have to be formed over the entire circumference of the cylindrical plate portion 43, for example, it is formed only on a part in the circumferential direction of the cylindrical plate portion 43. Also good. Specifically, for example, in the cylindrical plate portion 43, a plurality of enlarged diameter cylindrical portions 48 may be formed at predetermined intervals in the circumferential direction, and ribs may be formed between the respective radial cylindrical portions 48. . In addition, what is necessary is just to let the shape of this rib be the longitudinal cross-sectional shape corresponded to the cylindrical board part 43 of embodiment of FIG. 3, for example. By forming a rib between the plurality of enlarged diameter cylindrical portions 48, the strength of the connecting flange 40 can be improved. In this case, each rib may be disposed so that the plurality of ribs coincide with the bolt holes 44a of the fastening plate portion 44 in the radial direction, or the plurality of ribs may be arranged in the radial direction with the plurality of bolt holes 44a. Each rib may be disposed so as to be displaced. Further, for example, in the configuration of FIG. 3, the portion between the cylindrical plate portion 43 and the fastening plate portion 44 is locally folded back to the bead wire 46 side (obliquely upper side in FIG. 3) to deform this portion. It can also be set as the reinforcement part equivalent to the enlarged diameter cylinder part 48 of Example 2. FIG.

  As described above, the present invention can increase the manufacturing cost of the flexible joint, easily attach and detach the connecting flange from the flexible cylindrical portion, and reliably prevent the neck of the connecting flange from being removed. The above usability is high.

DESCRIPTION OF SYMBOLS 10 Flexible joint 20 Flexible cylinder part 21 Main body part 22 Sealing part 22a Sealing surface 23 Outer peripheral wall part 27 Taper part 40 Connecting flange 41 Inner peripheral plate part 42 Receiving plate part 42a Receiving surface 43 Intermediate plate part (tubular plate) Part)
44 Fastening plate portion 45 Outer peripheral plate portion 45a Tip surface 48 Expanded cylindrical portion 50 Bead wire

Claims (9)

A flexible joint comprising a flexible cylindrical portion having flexibility, and connecting flanges respectively connected to both axial end portions of the flexible cylindrical portion,
The flexible cylindrical portion includes a cylindrical main body portion, an annular seal portion that extends radially outward from an axial end portion of the main body portion to form a sealing surface for a companion flange on the surface, and the seal portion A cylindrical outer peripheral wall portion that is bent from the outer peripheral end portion toward the axially inner side of the main body portion,
The connecting flange is formed by folding back a sheet metal, and is formed on a cylindrical inner peripheral plate portion that is externally fitted to an axial end portion of the main body portion, and a receiving surface of the seal portion formed on the back surface side of the seal portion. An annular receiving plate portion, and a cylindrical plate portion fitted into the outer peripheral wall portion,
An annular bead wire is embedded in the outer peripheral wall portion of the flexible tube portion. In claim 1,
The flexible joint according to claim 1, wherein the receiving surface of the receiving plate portion is formed in an annular planar shape. In claim 1 or 2,
A flexible joint characterized in that a space is formed on the outer peripheral side of the outer peripheral wall portion of the flexible cylindrical portion. In any one of Claims 1 thru | or 3,
The connection flange further includes an annular fastening plate portion extending radially outward from an axially inner end portion of the cylindrical plate portion and having a plurality of bolt holes opened therein. In claim 4,
In the cylindrical plate portion of the connecting flange, an expanded cylindrical portion that is expanded radially outward as it goes inward in the axial direction of the main body portion is formed in at least a part of the circumferential direction,
The fastening plate portion extends radially outward from the axially inner end portion of the enlarged diameter cylindrical portion,
The flexible joint is characterized in that a taper portion is formed on an outer peripheral wall portion of the flexible tube portion so that the diameter-enlarged tube portion is fitted therein. In claim 4 or 5,
The connecting flange includes an outer peripheral plate portion that is bent from an outer peripheral end portion of the annular plate portion toward an outer side in the axial direction of the flexible cylindrical portion,
The flexible joint according to claim 1, wherein a contact surface that contacts the companion flange is formed on a front end surface of the outer peripheral plate portion. In claim 6,
The front end surface of the outer peripheral plate portion is located between the receiving surface of the receiving plate portion and the surface of the seal portion in the axial direction of the main body portion. In any one of Claims 4 thru | or 7,
The outer peripheral wall portion of the flexible tube portion extends inward in the axial direction of the main body portion so as to contact the annular plate portion,
The bead wire is embedded in the front end portion of the outer peripheral wall portion, and is a flexible joint. In any one of claims 1 to 8,
A flexible joint, wherein a diameter of the bead wire is longer than an axial distance between the receiving plate portion and the companion flange when the connection flange and the companion flange are connected.

Images