JP2014109372A - Extending flexible joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance displacement absorbing capability by an extending flexible joint 1 which has elastic seal rings 6A, 6B installed between two axially opposed ring bodies 2, 3 which are arranged apart from each other in an axial direction while suppressing a rise in facility cost, and to improve response of an extending operation of the extending flexible joint.SOLUTION: An extending flexible joint 1 includes: first and secondo ring bodies 2, 3; at least one intermediate ring body 4 arranged between the first and second ring bodies 2, 3; at least two elastic seal rings 6A, 6B which are arranged between the intermediate ring body 4 and the first and second ring bodies 2, 3 opposed to each other in an axial direction, and each have one axial end and the other end fixed to the intermediate ring body 4 and the first and second ring bodies 2, 3 respectively; a support member 5 which supports the intermediate ring body from an inner-diameter side and guides the intermediate ring body 4 in an axially displaceable state; and protecting means 7A, 7B which limit operation ranges of the elastic seal rings 6A, 6B.

Description

  The present invention relates to an expansion / contraction flexible joint of a culvert that has flexibility for use in a culvert connection such as a water and sewage ditch, a common ditch, an agricultural water supply, or the like.

  The applicant of the present application has proposed a stretchable flexible joint as shown in Patent Document 1, for example. The elastic seal member used for this flexible joint has an upper half cross section of an inverted “Ω” shape or a semicircular shape, and the maximum allowable amount of expansion / contraction operation or bending operation is, for example, that of the material or internal configuration. In addition, it can be set as appropriate depending on the radius of curvature.

  By the way, as for the elastic seal member, for example, as shown in Patent Document 2, there is a bellows-like one.

  Further, for example, Patent Document 3 describes a joint with a multi-row structure in which three flexible bodies (corresponding to the elastic seal members) are arranged side by side in the axial direction on the separated portion of the culvert separated in the axial direction. Yes. In this joint, in order to prevent the central portion of each flexible body from being excessively stretched and damaged, an overstretch prevention material is provided.

Japanese Patent No. 4186003 Japanese Patent Publication No.59-9720 Japanese Utility Model Publication No. 56-32710

  In Patent Documents 1 and 2, when increasing the axial and radial displacement absorption capacity of the expansion / contraction flexible joint, it is necessary to increase the outer size such as the axial dimension and the radial dimension of the elastic seal member. At the same time, it is necessary to increase the strength of the structure for fixing both axial ends of the elastic seal member.

  In that case, naturally, the manufacturing cost and the weight of the elastic seal member increase, and the manufacturing cost and the weight related to the fixing structure of the elastic seal member increase, which increases the equipment cost of the expansion / contraction flexible joint. Is concerned.

  In the case of the above-mentioned Patent Document 2, if the elastic seal member is not elastically deformed, its inner diameter is small, but when the elastic support member is elastically deformed radially inward, this elastic deformation is performed. It is necessary to secure a large space for allowing For this reason, when the outer diameter of the entire expansion / contraction flexible joint is limited, the internal space of the entire expansion / contraction flexible joint becomes small.

  Moreover, in the said patent document 3, compared with the said patent documents 1 and 2, it can be said that the displacement absorption capability by a joint can be increased, suppressing the raise of an installation cost. However, in the case of this patent document 3, since earth pressure is acting on each joined body and it does not guide the axial displacement operation | movement of each joined body, it is thought that the expansion-contraction operation | movement of a joint is bad.

  In view of such circumstances, the present invention relates to an expansion / contraction flexible joint in which an elastic seal ring is installed between axially opposed two annular members that are spaced apart in the axial direction, while suppressing an increase in equipment cost. An object of the present invention is to make it possible to increase the displacement absorption capacity of the expansion / contraction flexible joint and to improve the responsiveness of the expansion / contraction operation of the expansion / contraction flexible joint.

  The expansion / contraction flexible joint according to the present invention includes first and second annular bodies that are spaced apart in the axial direction, at least one intermediate annular body that is disposed between the first and second annular bodies, and the intermediate ring. At least two fixed to the intermediate ring and the first and second rings, respectively, between the axially opposite ends of the body and the first and second rings. Two elastic seal rings, a support member that supports the intermediate ring from the inner diameter side and guides the intermediate ring so as to be axially displaceable, and protection means that limits the operating range of the elastic seal ring. It is characterized by that.

  In this configuration, since the at least two elastic seal rings are arranged in a row in the axial direction, the load is applied when a thrust load or a radial load is applied to the expansion / contraction flexible joint according to the present invention. The at least two elastic seal rings can be shared. From this, it becomes clear that the axial and radial displacement absorbing ability of the expansion / contraction flexible joint increases as the number of the elastic seal rings is increased.

  Therefore, when a plurality of elastic seal rings are formed in a multi-row structure as in the present invention, it is possible to increase the displacement absorption capability of the expansion / contraction flexible joint compared to the conventional example using one elastic seal ring with a small outer size. It becomes possible.

  In other words, in the present invention, it is possible to use an elastic seal ring having a small outer size when obtaining a predetermined displacement absorbing capacity of the expansion / contraction flexible joint. Therefore, the conventional example using one elastic seal ring having a large outer size is used. In comparison, the manufacturing cost and weight of the elastic seal ring itself can be reduced, and the strength of the fixing structure of the elastic seal ring need not be so high. It becomes possible to reduce. Thereby, it becomes possible to suppress an increase in equipment cost and weight of the expansion / contraction flexible joint.

  Further, when the present invention using a plurality of elastic seal rings having a relatively small outer size is compared with a conventional example using one elastic seal ring having a large outer size (approximately Ω shape or bellows in cross section), for example, However, it becomes possible to reduce the inner diameter of each of the plurality of elastic seal rings, or to the same extent. In addition, in the present invention, it is not necessary to increase the space for allowing elastic deformation in the radially inward direction of the elastic seal ring as in the case of using a bellows-like elastic seal ring having a large outer dimension as a conventional example. By these synergistic actions, in the present invention, it is possible to ensure a relatively large internal space of the entire expansion / contraction flexible joint when the outer diameter of the entire expansion / contraction flexible joint is limited.

  Moreover, since the intermediate ring is supported by the support member from the inner diameter side so that the intermediate ring can be displaced in the axial direction, the axial displacement operation of the intermediate ring during expansion and contraction of the expansion / contraction flexible joint. As a result, the responsiveness of the expansion / contraction operation of the expansion / contraction flexible joint is improved.

  Preferably, the support member is formed in a cylindrical shape, and the support member is attached to the second ring body in a cantilevered state so as to be concentric with the intermediate ring body, and the intermediate ring is mounted on an outer peripheral surface. The inner diameter portion of the body is slidably fitted.

  Here, it is specified that the support member is cylindrical, and the installation form of this support member, the support form of the intermediate ring body by the support member and the guide form are specified, and the design is clear when implementing them. become.

  Preferably, an inner diameter portion of the intermediate annular body is provided integrally with an annular plate portion protruding radially inward and an inner peripheral edge of the annular plate portion, and is axially slid on an outer peripheral surface of the cylindrical support member. It can be set as the structure containing the inner cylinder part fitted so that a movement is possible.

  Here, the configuration of the inner diameter portion of the intermediate ring is specified. Thus, when it is specified that the inner diameter portion of the support member and the intermediate ring is continuous in the circumferential direction, the load acting on the support member can be distributed in the circumferential direction. Compared with a configuration in which the support member is intermittently intermittently installed on the circumference, the support rigidity of the intermediate ring body by the support member is improved.

  Preferably, the number of the intermediate ring is one, and the protection means includes a first protection means for restricting a relative axial distance between the first ring and the intermediate ring, and the second ring. And a second protection means for restricting the relative axial separation between the body and the intermediate ring body.

  Here, it is specified that there is one intermediate ring and that there are two protective means. Thus, when one intermediate ring is provided, it becomes clear that there are two elastic seal rings.

  In addition, if two protection means are provided, it becomes clear that an excessive tensile load along the axial direction can be prevented from acting on the two elastic seal rings.

  Preferably, the first protection means is a string-like body having flexibility and a predetermined strength, and the first protection means made of the string-like body is provided between the inner end of the first ring body and the intermediate ring body. It is installed so as to be bridged between the axial portions facing the inner diameter portion.

  Here, it is clarified that the first protection means can be manufactured relatively easily by specifying the configuration of the first protection means. Thereby, it becomes advantageous when aiming at the cost reduction of the expansion-contraction flexible joint which concerns on this invention.

  Preferably, the second protection means includes an inner diameter portion of the intermediate ring body and a convex portion provided on an outer circumferential surface in the axial direction of the support member so as to contact the inner diameter portion of the intermediate ring body in the axial direction. It is set as the structure which combined.

  Here, it is clarified that the second protection means can be manufactured relatively easily by specifying the configuration of the second protection means. Thereby, it becomes advantageous when aiming at the cost reduction of the expansion-contraction flexible joint which concerns on this invention.

  Preferably, the number of the intermediate ring is two, and the protection means regulates a relative axial separation amount between the first ring and the first intermediate ring located adjacent to the first ring in the axial direction. A first protection means, a second protection means for regulating a relative axial separation between the second ring and the second intermediate ring located adjacent to the second ring, and the first intermediate ring; And a third protection means for restricting an axial separation relative to the second intermediate ring body.

  Here, it is specified that there are two intermediate ring bodies and that there are three protective means. Thus, it becomes clear that when two intermediate rings are provided, there are three elastic seal rings.

  It is also clear that if three protection means are provided, it is possible to prevent an excessive tensile load along the axial direction from acting on the three elastic seal rings.

  Preferably, the first and third protection means are a string-like body having flexibility and a predetermined strength, and the first protection means made of the string-like body includes an inner end portion of the first ring body and the first end. The third protective means, which is installed so as to be bridged between the axially opposite ends of the inner ring portion of the first intermediate ring body, is formed of the string-like body and the inner diameter portion of the first intermediate ring body and the second intermediate ring body. It can be set as the structure installed so that it may span between axial direction opposition with an internal-diameter part.

  Here, it is clarified that the first and third protection means can be manufactured relatively easily by specifying the configuration of the first and third protection means. Thereby, it becomes advantageous when aiming at the cost reduction of the expansion-contraction flexible joint which concerns on this invention.

  Preferably, the second protection means is provided so as to be able to contact the inner diameter portion of the first intermediate ring body and the inner diameter portion of the first intermediate ring body in the axial direction on the outer peripheral surface in the axial direction of the support member. It is set as the structure which combined the convex part.

  Here, it is clarified that the second protection means can be manufactured relatively easily by specifying the configuration of the second protection means. Thereby, it becomes advantageous when aiming at the cost reduction of the expansion-contraction flexible joint which concerns on this invention.

  The present invention relates to an expansion / contraction flexible joint in which an elastic seal ring is installed between two axially spaced annular bodies opposed to each other in the axial direction, and the displacement absorption by the expansion / contraction flexible joint is suppressed while suppressing an increase in equipment cost. The capability can be increased, and the responsiveness of the expansion / contraction operation of the expansion / contraction flexible joint can be improved.

It is a longitudinal cross-sectional view which shows Embodiment 1 of the expansion-contraction flexible joint which concerns on this invention. It is a longitudinal cross-sectional view of the upper half which shows the state by which the 1st elastic seal ring of the expansion-contraction flexible joint of FIG. 1 was pulled by the axial direction. FIG. 3 is a longitudinal sectional view of the upper half showing a state where the second elastic seal ring is further pulled in the axial direction from the state of FIG. 2. FIG. 3 is an upper half longitudinal sectional view showing a state in which a first ring body of the expansion / contraction flexible joint of FIG. 1 is displaced in the radial direction and the first elastic seal ring is pulled obliquely in the radial direction. FIG. 3 is a longitudinal sectional view of the upper half showing a state where the first and second elastic seal rings of the expansion / contraction flexible joint of FIG. 1 are compressed in the axial direction. It is a figure for demonstrating an example of the usage place of the expansion-contraction flexible joint of FIG. It is a longitudinal cross-sectional view which shows Embodiment 2 of the expansion-contraction flexible joint which concerns on this invention. FIG. 8 is a longitudinal sectional view of the upper half showing a state in which the first elastic seal ring of the expansion / contraction flexible joint of FIG. 7 is pulled in the axial direction. FIG. 9 is a longitudinal sectional view of the upper half showing a state in which the third elastic seal ring is further pulled in the axial direction from the state of FIG. 8. FIG. 10 is a longitudinal sectional view of the upper half showing a state where the second elastic seal ring is further pulled in the axial direction from the state of FIG. 9. FIG. 8 is a longitudinal sectional view of the upper half showing a state in which the first annular body of the expansion / contraction flexible joint of FIG. 7 is displaced in the radial direction and the first elastic seal ring is pulled obliquely downward in the radial direction. FIG. 8 is a longitudinal sectional view of the upper half showing a state in which the first to third elastic seal rings of the expansion / contraction flexible joint of FIG. 7 are compressed in the axial direction. It is a longitudinal cross-sectional view which shows the other example of the fixing structure of the 1st, 2nd elastic seal ring in Embodiment 1 shown in FIG.

  BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the accompanying drawings.

Embodiment 1
1 to 6 show Embodiment 1 of the present invention. Prior to description of the expansion / contraction flexible joint according to the present invention, an example of a place where the expansion / contraction flexible joint is used will be described with reference to FIG.

  As shown in FIG. 6, 101 and 102 are underground shafts, and 103 is a culvert composed of a horizontal hole. The expansion / contraction flexible joint 1 according to the present invention is installed near the first shaft 101 in the underdrain 103. In addition, as shown by the two-dot chain line in FIG. 6, the expansion / contraction flexible joint 1 can be installed at an appropriate position in the middle of the underpass in the longitudinal direction, or at a position near the second shaft 102 in the underpass 103. It is.

  The details of such an expansion / contraction flexible joint 1 will be described in detail with reference to FIGS. 1 to 5. In addition, in the figure, the black-painted part has shown the welding location.

  The expansion / contraction flexible joint 1 shown in Embodiment 1 has a two-row structure in which two elastic seal rings 6A and 6B are arranged side by side in the axial direction.

  Specifically, the expansion / contraction flexible joint 1 is formed in a tubular shape and mainly includes first and second ring bodies 2 and 3, a single intermediate ring body 4, a support member 5, and first and second elastic seals. Rings 6A and 6B, first and second protection means 7A and 7B, and the like are provided.

  In this embodiment, the cylindrical portions 2A and 3A, the intermediate ring body 4 and the support member 5 of the first and second ring bodies 2 and 3 are formed in a cylindrical shape. Of these, the cylindrical portions 2A and 3A of the first and second annular bodies 2 and 3 and the support member 5 are not continuous in the circumferential direction in addition to a continuous form in the circumferential direction when being cylindrical. In other words, it is possible to adopt a form in which fan-shaped blocks divided into a plurality at equal intervals around the circumference are combined in a cylindrical shape. Similarly to the above, the annular plate portions 2B and 3B of the first and second annular bodies 2 and 3 are not only continuous in the circumferential direction but also discontinuous in the circumferential direction, that is, at equal intervals around the circumference. It is possible to adopt a form in which a plurality of fan-shaped blocks are combined in a disc shape.

  The first ring body 2 has a configuration in which one axial end side of the cylindrical portion 2A is integrally connected to one side surface of the annular plate portion 2B by welding or the like, for example. The annular plate portion 2 </ b> B of the first ring body 2 is integrally fixed to the wall portion of the first shaft 101. This fixing uses an anchor bolt 11 or the like.

  The second annular body 3 has a configuration in which one axial end side of the cylindrical portion 3A is integrally connected to one side surface of the annular plate portion 3B by welding or the like, for example. The annular plate portion 3B of the second annular body 3 is integrally fixed to one end side in the axial direction of the underdrain 103. This fixing uses an anchor bolt 12 or the like. The cylindrical portion 3A of the second annular body 3 is separated from the cylindrical portion 2A of the first annular body 2 by a predetermined distance in the axial direction.

  The intermediate annular body 4 is disposed between the axial portions of the cylindrical portion 2A of the first annular body 2 and the cylindrical portion 3A of the second annular body 3, and the first elastic seal ring is connected to the cylindrical portion 2A of the first annular body 2. It is connected via 6A and is connected to the cylindrical portion 3A of the second ring 3 via a second elastic seal ring 6B.

  The inner ring portion of the intermediate ring body 4 has an annular plate portion 4a protruding radially inward, and an inner cylinder integrally connected to the inner peripheral edge of the annular plate portion 4a so as to be concentric with the intermediate ring body 4 Part 4b. The inner cylinder portion 4b is fixed to the inner peripheral edge of the annular plate portion 4a by, for example, welding.

  The support member 5 supports the intermediate ring 4 from the inner diameter side and guides the axial displacement of the intermediate ring 4. Reinforcing ribs 5a projecting radially inward are provided at several locations on the inner peripheral surface of the support member 5.

  The support member 5 is attached to the inner end surface of the annular plate portion 3B of the second ring body 3 so as to be concentric with the cylindrical portion 3A of the second ring body 3 and in a cantilever support state. Yes. For example, the bolts 13 are used for this attachment. The inner cylindrical portion 4b of the intermediate ring 4 is fitted on the outer peripheral surface of the support member 5 so as to be slidable.

  The first and second elastic seal rings 6A and 6B have an inverted “Ω” shape or semicircular cross section, and are coated with an elastic body such as rubber using a core material of appropriate reinforcing fibers. Structure (bias structure). The allowable expansion / contraction amount and allowable deflection amount of the first and second elastic seal rings 6A and 6B can be appropriately set depending on, for example, the radius of curvature of the semicircular portion in addition to the material and the internal structure.

  The axial direction one end side and the other end side of the first and second elastic seal rings 6A, 6B are the inner diameters of the cylindrical portions 2A, 3A of the first and second ring bodies 2, 3 and the intermediate ring body 4, respectively. It is fixed on the side. This fixed form will be described later in detail.

  The first and second protection means 7A and 7B are provided to limit the operating range of the first and second elastic seal rings 6A and 6B.

  The first protection means 7A limits the operating range of the first elastic seal ring 6A by restricting the relative axial distance between the cylindrical portion 2A of the first ring body 2 and the intermediate ring body 4. The tensile load acting on the first elastic seal ring 6A is limited.

  The first protection means 7A is a string-like body (wire or chain made of metal or engineering plastic) having flexibility and a predetermined strength, and is installed at equal intervals around the circumference. In the case of the first protection means 7A made of the string-like body, one end side in the longitudinal direction is on the inner end face of the annular plate portion 2B of the first ring body 2, and the other end side in the longitudinal direction is the annular plate portion 4a of the intermediate ring body 4. The first protection means 7A is installed so as to be bridged between the first ring body 2 and the intermediate ring body 4 facing each other in the axial direction.

  When the first protective means 7A made of the string-like body is completely extended, the first elastic seal ring 6A is not fully extended, but leaves a predetermined margin in the axial extension direction. It is set to be. By doing so, the first elastic seal ring 6A is protected from being easily damaged.

  The second protection means 7B limits the operation range of the second elastic seal ring 6B by restricting the relative axial distance between the cylindrical portion 3A of the second ring 3 and the intermediate ring 4. The tensile load acting on the second elastic seal ring 6B is limited.

  This 2nd protection means 7B is set as the structure which combined the cyclic | annular convex part 5b and the inner cylinder part 4b of the intermediate | middle ring 4. The annular convex portion 5 b is integrally provided on the outer peripheral surface on the protruding end (free end) side of the support member 5 that is integrally connected to the second annular body 3. The annular protrusion 5b is fixed to the support member 5 by welding or the like, for example.

  In the case of the second protection means 7B having such a configuration, the intermediate ring 4 is displaced from the first ring 2 and the first ring 2 as the first ring 2 is displaced along the axial direction away from the second ring 3. 1 When pulled by the elastic seal ring 6A and displaced in the same direction as the displacement direction of the first ring body 2, or the second ring body 3 is displaced along the axial direction away from the first ring body 2. Sometimes, the axial one end of the inner cylindrical portion 4b of the intermediate ring 4 and the annular convex portion 5b of the support member 5 come into contact with each other. When abutting in this way, the second elastic seal ring 6B is set not to be in a fully extended state but to leave a predetermined margin in the axial extension direction. By doing so, the second elastic seal ring 6B is protected from being easily damaged.

  Next, a procedure for fixing the first and second elastic seal rings 6A and 6B to the first and second ring bodies 2 and 3 and the intermediate ring body 4 will be described.

  For this fixing, four mounting brackets 21 to 24, four stud bolts 31 to 34, and four nuts 41 to 44 are used. The stud bolts 31 to 34 and the nuts 41 to 44 constitute a fastening member (reference numeral omitted).

  Although the mounting brackets 21 to 24 are cylindrical members, the mounting brackets 21 to 24 are discontinuous in the circumferential direction, that is, a form in which fan blocks divided into a plurality at equal circumferential intervals are combined into a cylindrical shape. . On one end side in the axial direction of the mounting brackets 21 to 24, step portions 21a to 24a having outer diameters smaller than those of other regions are provided. Bolt insertion holes 21 b to 24 b are provided at several places in the circumference of the other region of the mounting brackets 21 to 24.

  The stud bolts 31 to 34 are welded in a state where the stud bolts 31 to 34 are implanted radially inward at predetermined positions of the cylindrical portions 2A and 3A of the first and second annular bodies 2 and 3 and the intermediate annular body 4. It is fixed. The nuts 41 to 44 are screwed onto the protruding end sides of the stud bolts 31 to 34.

  Ring-shaped projections 2a, 3a, 4c projecting radially inward on the inner end sides of the cylindrical portions 2A, 3A of the first and second ring bodies 2, 3 and on both axial ends of the intermediate ring body 4, respectively. , 4d are provided integrally.

  The first and second elastic seals are formed on the inner peripheral surface on the inner end side of each of the cylindrical portions 2A and 3A of the first and second ring bodies 2 and 3, and on the inner peripheral surface on both axial ends of the intermediate ring body 4. One end side and the other end side in the axial direction of the rings 6A and 6B are pressed.

  In this state, the outer circumferences of the step portions 21a to 24a of the mounting brackets 21 to 24 are pressed from the inner diameter side to the one end side and the other end side in the axial direction of the first and second elastic seal rings 6A and 6B. The bolt insertion holes 21b to 24b of the mounting brackets 21 to 24 are fitted into the stud bolts 31 to 34 that are fixed to the cylindrical portions 2A and 3A and the intermediate ring 4 of the first and second rings 2 and 3, Nuts 41 to 44 are screwed onto the protruding end sides of the stud bolts 31 to 34.

  Thereby, each axial direction one end side and other end side of 1st, 2nd elastic seal ring 6A, 6B are the step parts 21a-24a of each attachment bracket 21-24, and each of the 1st, 2nd ring bodies 2, 3 It is sandwiched between the cylindrical portions 2A, 3A and the inner peripheral surface of the intermediate ring 4, and the front ends of the step portions 21a-24a of the mounting brackets 21-24, the first and second rings 2, 3 and It will be sandwiched between the ring-shaped protrusions 2a, 3a, 4c, 4d of the intermediate ring 4 so that the first and second axial ends of the first and second elastic seal rings 6A, 6B are the first, The second ring bodies 2 and 3 are fixed to the cylindrical portions 2A and 3A and the intermediate ring body 4, respectively.

  Next, with reference to FIGS. 2 to 5, the movement of the expansion / contraction flexible joint 1 will be described.

  First, a case will be described in which the first ring 2 is displaced along the axial direction in the direction of the arrow in FIG. 1 (right side), that is, away from the second ring 3 due to ground change due to, for example, an earthquake. As the first ring body 2 is displaced, the first elastic seal ring 6A gradually extends, so that the expansion of the full length of the expandable flexible joint 1 can be absorbed.

  When the first ring body 2 is further displaced in the same direction as described above, as shown in FIG. 2, when the string-like body as the first protection means 7A is completely extended, the first protection means 7A and the first protection means 7A Since the one ring body 2 pulls the intermediate ring body 4 in the same direction as the displacement direction of the first ring body 2, it is possible to absorb the extension of the full length of the expandable flexible joint 1. In this displacement process, the first elastic seal ring 6A is set not to be in a fully extended state but to leave a predetermined margin in the axial extension direction. Is avoided from being damaged.

  In this state, when the first ring body 2 is further displaced in the same direction as described above, the second elastic seal ring 6B gradually expands, so that the expansion of the full length of the expandable flexible joint 1 can be absorbed.

  Thereafter, when the first ring body 2 is further displaced in the same direction as described above, as shown in FIG. 3, one end side in the axial direction of the inner cylindrical portion 4b of the intermediate ring body 4 constituting the second protection means 7B is the support member 5. It will contact | abut to this cyclic | annular convex part 5b. In this state, the second elastic seal ring 6B is set so as not to extend completely but to leave a predetermined margin in the axial extension direction, so that the second elastic seal ring 6B may be damaged. Avoided.

  In this state, when the first ring body 2 is further displaced in the same direction as described above, the second protection means 7B and the intermediate ring body 4 cause the support member 5 and the second ring body 3 to move in the same direction as the displacement direction of the first ring body 2. Therefore, the expansion of the full length dimension of the expansion / contraction flexible joint 1 can be absorbed.

  Next, a case where the second ring body 3 is displaced along the axial direction on the side away from the first ring body 2 will be described. Although not shown, first, the second elastic seal ring 6B gradually expands with the displacement of the second ring body 3, so that the extension of the full length of the expansion / contraction flexible joint 1 can be absorbed.

  When the second ring body 3 is further displaced in the same direction as described above, the annular convex portion 5b of the support member 5 integrally connected to the second ring body 3 is connected to one end in the axial direction of the inner cylindrical portion 4b of the intermediate ring body 4. Will come into contact with the side. In this state, the second elastic seal ring 6B is set so as not to extend completely but to leave a predetermined margin in the axial extension direction, so that the second elastic seal ring 6B may be damaged. Avoided.

  Thereafter, when the second ring body 3 is further displaced in the same direction as described above, the second protection means 7B and the intermediate ring body 4 pull the first ring body 2 in the same direction as the displacement direction of the second ring body 3. However, in the process, the first elastic seal ring 6A gradually expands, so that the expansion of the full length dimension of the expansion / contraction flexible joint 1 can be absorbed.

  In this state, when the second ring body 3 is further displaced in the same direction as described above, the string-like body as the first protection means 7A is completely extended. In the displacement process, the first elastic seal ring 6A is The first elastic seal ring 6A is prevented from being damaged because it is set so as to leave a predetermined margin in the axial extension direction without being completely extended.

  By the way, if, for example, as shown in FIG. 4, the first ring body 2 is shifted downward (in the direction of the arrow) due to a ground change due to an earthquake or the like, the first elastic seal ring 6 </ b> A is inclined diagonally downward in the radial direction. The expansion / contraction flexible joint 1 can absorb the misalignment between the first ring body 2 and the second ring body 3 by gradually extending.

  Further, for example, as shown in FIG. 5, for example, due to a ground change due to an earthquake or the like, the first ring 2 and the second ring 3 are displaced along the axial direction in the direction in which the first ring 2 and the second ring 3 approach (arrow direction). The first and second elastic seal rings 6 </ b> A and 6 </ b> B are compressed in the axial direction, and the contraction of the overall length of the expansion / contraction flexible joint 1 can be absorbed. Absorption of this shrinkage is performed until the cylindrical portion 2A of the first ring body 2, the intermediate ring body 4, and the cylindrical portion 3 A of the second ring body 3 that are adjacent in the axial direction come into contact with each other.

Embodiment 2
7 to 12 show Embodiment 1 of the present invention. Prior to description of the expansion / contraction flexible joint according to the present invention, an example of a place where the expansion / contraction flexible joint is used will be described with reference to FIG.

  The expansion / contraction flexible joint 1 according to the first embodiment has a two-row structure in which two elastic seal rings 6A and 6B are arranged side by side in the axial direction. The seal rings 6A to 6C have a three-row structure in which the seal rings 6A to 6C are arranged in the axial direction.

  Specifically, the expansion / contraction flexible joint 1 according to the second embodiment mainly includes first and second annular bodies 2 and 3, first and second intermediate annular bodies 4 </ b> A and 4 </ b> B, a support member 5, and first to third. Elastic seal rings 6A to 6C, first to fifth protection means 7A to 7E, and the like are provided.

  The first and second intermediate ring bodies 4A and 4B are the intermediate ring body 4 shown in the first embodiment, and the third elastic seal ring 6C is the first and second elastic seal rings 6A and 6B shown in the first embodiment. Each has basically the same configuration.

  The first, third and fourth protection means 7A, 7C and 7D are the first protection means 7A shown in the first embodiment, and the second and fifth protection means 7B and 7E are the first protection means shown in the first embodiment. Each of the two protection means 7B has basically the same configuration.

  The first to fifth protection means 7A to 7E are provided to limit the operating range of the first to third elastic seal rings 6A to 6C.

  The first protection means 7A controls the first elastic member by regulating the relative axial distance between the cylindrical portion 2A of the first ring body 2 and the first intermediate ring body 4A located next to the cylindrical portion 2A. While restricting the operating range of the seal ring 6A, the tensile load acting on the first elastic seal ring 6A is restricted.

  The first protection means 7A is a string-like body (wire or chain made of metal or engineering plastic) having flexibility and a predetermined strength, and is installed at equal intervals around the circumference.

  The first protection means 7A made of the string-like body has one end side in the longitudinal direction on the inner end face of the annular plate portion 2B of the first ring body 2 and the other end side in the longitudinal direction on the annular plate portion of the first intermediate ring body 4A. By being fixed to one side surface of 4a, the first protection means 7A is installed so as to be bridged between the first ring body 2 and the first intermediate ring body 4A facing each other in the axial direction.

  The second protection means 7B regulates the relative axial distance between the cylindrical portion 3A of the second annular body 3 and the second intermediate annular body 4B located adjacent to the axial direction of the cylindrical portion 3A. While restricting the operating range of the seal ring 6B, the tensile load acting on the second elastic seal ring 6B is restricted.

  This 2nd protection means 7B is set as the structure which combined the annular convex part 5b provided in the middle of the axial direction of the supporting member 5, and the inner cylinder part 4b of the 2nd intermediate | middle ring 4B. The annular protrusion 5b is provided integrally in the middle of the outer peripheral surface of the support member 5 that is integrally connected to the second ring body 3 in the axial direction. The annular protrusion 5b is fixed to the support member 5 by welding or the like, for example.

  In the case of the second protection means 7B having such a configuration, the intermediate ring 4 is displaced from the first ring 2 and the first ring 2 as the first ring 2 is displaced along the axial direction away from the second ring 3. 1 When pulled by the elastic seal ring 6A and displaced in the same direction as the displacement direction of the first ring body 2, or the second ring body 3 is displaced along the axial direction away from the first ring body 2. Sometimes, the axial one end of the inner cylindrical portion 4b of the second intermediate ring 4B comes into contact with the annular convex portion 5b of the support member 5. When abutting in this way, the second elastic seal ring 6B is set not to be in a fully extended state but to leave a predetermined margin in the axial extension direction. By doing so, the second elastic seal ring 6B is protected from being easily damaged.

  The third protection means 7C restricts the operation range of the third elastic seal ring 6C by restricting the relative axial distance between the first intermediate ring 4A and the second intermediate ring 4B, The tensile load acting on the third elastic seal ring 6C is limited.

  The third protection means 7C is a string-like body similar to the first protection means 7A, and is installed at equal intervals in several places around the circumference. The third protective means 7C made of the string-like body has one end side in the longitudinal direction on one side surface of the annular plate portion 4a of the first intermediate ring body 4A and the other end side in the longitudinal direction is the annular plate plate of the second intermediate ring body 4B. By being respectively fixed to one side surface of the portion 4a, the third protection means 7C is installed so as to be bridged between the axially opposed first intermediate ring 4A and second intermediate ring 4B.

  The fourth protection means 7D regulates the relative axial distance between the second ring 3 and the second intermediate ring 4B located adjacent to the second ring 3 in the axial direction, thereby allowing the second elastic seal ring 6B to While restricting the operating range, it limits the tensile load acting on the second elastic seal ring 6B.

  The fourth protection means 7D is a string-like body similar to the first protection means 7A, and is installed at equal intervals in several places around the circumference. In the fourth protection means 7D formed of the string-like body, one end side in the longitudinal direction is on the inner end face of the annular plate portion 3B of the second ring body 3, and the other end side in the longitudinal direction is the annular plate portion 4a of the second intermediate ring body 4B. By being respectively fixed to one side surface, the fourth protection means 7D is installed so as to be spanned between the second ring body 3 and the second intermediate ring body 4B facing each other in the axial direction.

  The fifth protection means 7E restricts the first, second, third and fourth protection means 7A, 7C, 7D from acting excessive thrust loads on them in the state where they are extended to the maximum. While restrict | limiting the operation | movement range of each elastic seal ring 6A-6C, the tensile load which acts on the 1st-3rd elastic seal rings 6A-6C whole is restrict | limited.

  The fifth protection means 7E is configured by combining an annular convex portion 5c provided on the distal end side of the support member 5 and an inner cylindrical portion 4b of the first intermediate ring 4A. The annular convex portion 5 c is integrally provided on the distal end side in the axial direction on the outer peripheral surface of the support member 5 that is integrally connected to the second annular body 3. The annular convex portion 5c is fixed to the support member 5 by welding or the like, for example.

  In the case of the fifth protection means 7E, for example, as shown in FIG. 10, when all of the first, third, and fourth protection means 7A, 7C, and 7D made of string-like bodies are fully extended, One end in the axial direction of the inner cylindrical portion 4b of the first intermediate ring 4A comes into contact with the annular convex portion 5c. Accordingly, the first ring body 2 and the second ring body 3 are restricted so as not to be further separated from each other in the axial direction from the current state.

  In the expansion / contraction flexible joint 1 of the second embodiment, the action of absorbing the displacement such as the expansion / contraction operation or the eccentric operation of the undercarriage 103 is basically the same as in the case of the first embodiment, and a detailed description thereof is omitted here. To do.

  As described above, in Embodiments 1 and 2 to which the present invention is applied, a plurality of elastic seal rings 6A, 6B, and 6C) are arranged in a row in the axial direction. On the other hand, when a thrust load or a radial load is applied, the load can be shared by the plurality of elastic seal rings 6A, 6B, 6C.

  Therefore, in the first and second embodiments, it is possible to increase the displacement absorption capacity of the expansion / contraction flexible joint 1 as compared with the conventional example using one elastic seal ring having a small outer size.

  That is, in the first and second embodiments, it is possible to use the elastic seal rings 6A, 6B, 6C having a small outer size in order to obtain the predetermined displacement absorbing capacity of the expansion / contraction flexible joint 1, and therefore, the elasticity having a large outer size is used. The manufacturing cost and weight of the elastic seal rings 6A, 6B, 6C themselves can be reduced as compared with the conventional example using one seal ring, and the elastic seal rings 6A, 6B, 6C can be fixed (attached). Since it is not necessary to increase the strength of the metal fittings 21 to 26, the stud bolts 31 to 36, and the nuts 41 to 46), it is possible to reduce the manufacturing cost and weight related to the fixing structure. Thereby, it becomes possible to suppress an increase in equipment cost and weight of the expansion / contraction flexible joint 1.

  Also, Embodiments 1 and 2 using a plurality of elastic seal rings 6A, 6B and 6C having a relatively small outer size, and a conventional example using one elastic seal ring having a large outer size (substantially Ω shape or bellows shape), for example. In the first and second embodiments, the inner diameters of the plurality of elastic seal rings 6A, 6B, and 6C can be made smaller or comparable. Moreover, in the first and second embodiments, it is necessary to increase a space for allowing elastic deformation of the elastic seal ring inward in the radial direction as in the case of using a bellows-like elastic seal ring having a large outer dimension as a conventional example. Disappear. Due to these synergistic effects, in Embodiments 1 and 2, it is possible to ensure a relatively large internal space of the entire telescopic flexible joint 1 when the outer diameter of the entire telescopic flexible joint 1 is limited. Become.

  Further, since the intermediate ring 4 is supported by the support member 5 from the inner diameter side and the axial displacement of the intermediate ring 4 is guided, the axial direction of the intermediate ring 4 is extended when the expansion / contraction flexible joint 1 is expanded / contracted. As a result, the responsiveness of the expansion / contraction operation of the expansion / contraction flexible joint 1 is improved, for example, the displacement operation becomes smooth.

  In addition, this invention is not limited only to the said embodiment, It can change suitably in the range equivalent to the claim and the said range.

  (1) Each elastic seal ring 6A, 6B, 6C shown in the first and second embodiments can be formed in, for example, a bellows shape.

  (2) In the first and second embodiments, an example in which the support member 5 is formed in a cylindrical shape is given here, but the present invention is not limited to this. For example, although not shown, the support member 5 can have a configuration in which a plurality of sector blocks are intermittently arranged in the circumferential direction. In that case, a plurality of members constituting the support member 5 are arranged in a load zone above the lateral hole-shaped underdrain (see reference numeral 103 in FIG. 6) (a range of 60 degrees in total from 30 degrees in both circumferential directions from directly above). It is preferable to arrange one of the sector blocks.

  However, when the support member 5 is combined in a cylindrical shape or a continuous cylindrical shape as in the first and second embodiments, the load acting on the support member 5 can be distributed in the circumferential direction. Therefore, as compared with the configuration in which the support member 5 is intermittently arranged in the circumferential direction as described above, the support member 5 supports the intermediate ring 4 (first and second intermediate rings 4A and 4B). Increases rigidity.

  (3) In the first and second embodiments, the axial ends of the elastic seal rings 6A, 6B, and 6C are connected to the inner peripheral surface of the cylindrical portions 2A and 3A of the first and second annular bodies 2 and 3 and the intermediate annular body 4 respectively. Although the case where it fixes to the internal peripheral surface of (1st, 2nd intermediate ring body 4A, 4B) is mentioned as an example, this invention is not limited to this.

  For example, as shown in FIG. 13, the first and second annular bodies 2 and 3 are formed only by an annular plate, and then both axial ends of the first and second elastic seal rings 6A and 6B are aligned radially downward. In this way, the bent regions are formed on the inner surfaces of the first and second ring bodies 2 and 3 and the annular plate portion of the intermediate ring body 4 (first and second intermediate ring bodies 4A and 4B). It is possible to fix to 4a using attachment means (the same mounting brackets 21 to 24, stud bolts 31 to 34, and nuts 41 to 44 as in the first embodiment).

  In this case, it is possible to reduce the installation space in the axial direction of the attachment means as compared with the first embodiment, which is advantageous in reducing the total axial length of the telescopic flexible joint 1. Become.

  (4) The fourth and fifth protection means 7D and 7E shown in the second embodiment can be omitted. If omitted in this way, the tensile load resistance capacity in the maximum extension state of the expansion / contraction flexible joint 1 is reduced as compared with the case where the fourth and fifth protection means 7D and 7E are not omitted, but the equipment cost is reduced. It becomes possible to reduce.

  INDUSTRIAL APPLICABILITY The present invention can be suitably used for an expansion / contraction flexible joint in which an elastic seal ring is installed between axially opposed two annular bodies that are spaced apart in the axial direction.

1. Expansion and contraction flexible joint
2 1st ring
2A Tube part of the first ring
2B Annular plate part of the first ring
3 Second ring
3A 2nd ring cylinder
3B Annular plate part of second ring
4 Intermediate ring
4a Annular plate of intermediate ring
4b Inner tube of intermediate ring
5 Support members
6A 1st elastic seal ring
6B Second elastic seal ring
7A First protective means
7B Second protective means

Claims (9)

First and second annular bodies spaced apart in the axial direction;
At least one intermediate ring disposed between the first and second rings;
The intermediate ring is disposed between the first and second ring bodies facing each other in the axial direction, and one end and the other end in the axial direction are fixed to the intermediate ring and the first and second ring bodies, respectively. At least two elastic seal rings,
A support member that supports the intermediate ring from the inner diameter side and guides the intermediate ring so as to be axially displaceable;
The expansion / contraction flexible joint is provided with a protection means for limiting an operating range of the elastic seal ring. In the expansion-contraction flexible joint of Claim 1,
The support member is formed in a cylindrical shape,
The support member is attached to the second ring body in a cantilevered state so as to be concentric with the intermediate ring body, and an inner diameter portion of the intermediate ring body is slidably fitted to an outer peripheral surface. An expansion-contraction flexible joint characterized by being made. The expansion / contraction flexible joint according to claim 2,
An inner diameter portion of the intermediate annular body is provided integrally with an annular plate portion projecting radially inward, and an inner peripheral edge of the annular plate portion, and is slidable in an axial direction on the outer peripheral surface of the cylindrical support member. The expansion-contraction flexible joint characterized by including the inner cylinder part fitted together. In the expansion-contraction flexible joint of Claim 2 or 3,
The intermediate ring is one,
The protection means includes a first protection means for restricting a relative axial separation between the first ring body and the intermediate ring body;
The expansion-contraction flexible joint characterized by including the 2nd protection means which controls the relative axial separation of the said 2nd ring body and the said intermediate ring body. In the expansion-contraction flexible joint of Claim 4,
The first protection means is a string-like body having flexibility and a predetermined strength,
The expansion and contraction characterized in that the first protection means comprising the string-like body is installed so as to be bridged between the axial ends of the inner end portion of the first ring body and the inner diameter portion of the intermediate ring body. Flexible joint. The expansion / contraction flexible joint according to claim 4 or 5,
The second protection means is a combination of an inner diameter portion of the intermediate ring and a convex portion provided on an outer circumferential surface in the axial direction of the support member so as to be able to contact the inner diameter portion of the intermediate ring in the axial direction. An expansion / contraction flexible joint characterized by being configured. In the expansion-contraction flexible joint of Claim 2 or 3,
There are two intermediate rings,
The protection means includes a first protection means for restricting a relative axial separation between the first ring and a first intermediate ring located adjacent to the first ring, the second ring, and the second ring A second protective means for restricting a relative axial separation from a second intermediate ring located next to the second intermediate ring, and a relative axis between the first intermediate ring and the second intermediate ring The expansion-contraction flexible joint characterized by including the 3rd protection means which regulates the amount of separation of a direction. In the expansion-contraction flexible joint of Claim 7,
The first and third protection means are a string-like body having flexibility and a predetermined strength,
The first protection means made of the string-like body is installed so as to be bridged between the axial ends of the inner end portion of the first ring body and the inner diameter portion of the first intermediate ring body,
The third protection means made of the string-like body is installed so as to be bridged between axially opposed portions of the inner diameter portion of the first intermediate ring body and the inner diameter portion of the second intermediate ring body. Expansion and contraction flexible joint. The expansion / contraction flexible joint according to claim 7 or 8,
The second protection means includes an inner diameter portion of the first intermediate ring body and a convex portion provided on an outer peripheral surface in the axial direction of the support member so as to be able to contact the inner diameter portion of the first intermediate ring body in the axial direction. An expansion / contraction flexible joint characterized by comprising a combination of

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