JP2014092167A - Expansion joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bolt nut in which sliding movement is possible between a bolt and a nut, and an expansion joint having the bolt nut as a stopper and allowing elongation of a gap between pipes with a simple structure.SOLUTION: The expansion joint includes a bolt (4) having a shaft part (2) and a head part (3), a nut (6) having a plurality of split nuts (5) split in an axial direction and combined to be screwed with the shaft part, a ring shaped elastic body (7) arranged on an outer peripheral part of the nut, and a cylinder body (8) containing the nut and the elastic body therein and arranged on an outer peripheral part of the elastic body. When external force acting between the cylinder body and the bolt in the axial direction where the cylinder body is separated from the head part is equal to or more than the prescribed value, the cylinder body is slid to the bolt in the axial direction together with the nut and the elastic body.

Description

  The present invention relates to a slidingly movable bolt nut and an expansion joint capable of accepting expansion and contraction between pipes connected with the bolt nut as a stopper.

  A bolt and nut having a bolt and a nut is usually used to fasten objects, and is used so as to function alternatively between a fastening state and a releasing state.

  Further, in the expansion joint that connects the first pipe and the second pipe so as to accept the expansion and contraction, the distance between the first pipe and the second pipe becomes too large, and the first pipe and the second pipe are connected. A stopper is used to limit the elongation between the first pipe and the second pipe in order to prevent the expansion joint from coming off.

  There are various types of stoppers, and those using bolts and nuts are known.

JP 2004-116708 A

  Conventional bolts and nuts only have an alternative function between a state of fastening and a state of releasing fastening when fastening objects, and therefore, their applications are limited.

  Moreover, in the expansion joint provided with the conventional bolt nut as a stopper of an expansion joint, the stopper itself was not able to extend according to the expansion between piping.

  Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a bolt nut that enables sliding movement between the bolt and the nut depending on the magnitude of the external force, and this bolt nut as a stopper and is simple. It is to provide an expansion joint that allows an interval between pipes to be elongated with a simple structure.

  In order to achieve the above object, a bolt and nut according to the present invention includes a bolt having a shaft portion and a head, a nut that can be screwed into the shaft portion by combining a plurality of divided nuts divided in the axial direction, A ring-shaped elastic body disposed on the outer peripheral portion of the nut; and a cylindrical body that encloses the nut and the elastic body and is disposed on the outer peripheral portion of the elastic body, wherein the cylindrical body and the bolt When the external force acting in the axial direction in which the cylinder moves away from the head is larger than a predetermined value, the cylinder slides in the axial direction with respect to the bolt together with the nut and the elastic body It is characterized by doing.

  In addition, when the external force is greater than or equal to the predetermined value, a gap is generated between the plurality of split nuts, the hole diameter of the nut is increased, and the thickness of the elastic body is compressed in the radial direction. It is characterized by that.

  Further, when the external force is smaller than the predetermined value, the thickness of the elastic body is recovered in the radial direction, and the sliding movement is stopped.

The expansion joint according to the present invention is an expansion joint for connecting the first pipe and the second pipe so that the first pipe and the second pipe do not separate beyond a predetermined length in the axial direction. A stopper for limiting, the stopper includes a first reference portion provided on an outer peripheral portion of the first pipe, a second reference portion provided on an outer peripheral portion of the second pipe, and the first reference A bolt and nut spanned between a portion and the second reference portion, wherein the bolt nut is a combination of a bolt having a shaft portion and a head, and a plurality of axially divided nuts. A nut that can be screwed onto the shaft, a ring-shaped elastic body disposed on an outer peripheral portion of the nut, and a cylindrical body that includes the nut and the elastic body and is disposed on the outer peripheral portion of the elastic body. And the cylinder is separated from the head between the cylinder and the bolt. Expansion joint external force acting in the axial direction when a predetermined value or more in size, the cylindrical body is characterized in that the moving sliding axially relative to the bolt together with the elastic member and the nut that.

  Further, the head is supported by the first reference portion, and a portion of the cylindrical body on the opposite side of the head is supported by the second reference portion.

  Moreover, the said part of the said cylinder is supported by the said 2nd reference | standard part via the attachment member attached to the said 2nd reference | standard part, It is characterized by the above-mentioned.

  Further, the shaft portion of the bolt is a shaft rod formed with a male screw, and the head portion of the bolt is a mounting nut that is formed separately from the shaft rod and is screwed to the shaft rod. And

  Moreover, it has a stop member which prevents the said shaft part from slipping out of the said cylindrical body in the edge part on the opposite side to the said head part of the said shaft part.

  According to the configuration of the bolt and nut of the present invention, when the external force acting between the cylinder and the bolt in the axial direction in which the cylinder is separated from the head is larger than a predetermined value, the cylinder is elastic with the nut. Sliding movement in the axial direction with respect to the bolt together with the body, and sliding movement stops when the external force becomes less than the predetermined value, so that sliding movement can be selectively realized depending on the magnitude of the external force In addition, when the external force is greater than or equal to a predetermined value, the distance between the bolt head and the end of the cylinder can be increased.

  In addition, since the stopper of the expansion joint is provided with the above-mentioned bolt and nut, when the expansion joint is buried in the ground and receives an external force of a predetermined value or more due to the influence of an earthquake or the like, the expansion joint is disconnected from the first pipe and the second pipe. The distance between the first pipe and the second pipe in the axial direction can be extended substantially by the length of the cylindrical body without coming off.

The figure which shows one Embodiment of the volt | bolt nut of this invention. The figure which shows the case where the external force which acts between a cylinder and a volt | bolt in the axial direction which a cylinder separates from the head of a bolt is smaller than predetermined value. The figure which shows the cross section of A view in FIG. The figure which shows the case where external force begins to become more than predetermined value. The figure which shows the cross section of A view in FIG. The figure which shows the case where an external force becomes more than predetermined value. The figure which shows the cross section of A view in FIG. The figure which shows the case where it returns to the case where external force is smaller than predetermined value from the case shown in FIG. The figure which shows the cross section of A view in FIG. The figure which expands and shows B in FIG. The figure which expands and shows C in FIG. The figure which shows that a cylinder moves with respect to a nut and an elastic body, when a force acts between a cylinder and a volt | bolt in the axial direction in which a cylinder approaches the head of a bolt. The figure which shows one Embodiment of the expansion joint of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a view showing a bolt nut according to the present invention and one embodiment.

  The bolt nut 1 includes a bolt 6 having a shaft portion 2 and a head portion 3 and a plurality of divided nuts 5 (see FIG. 3 and the like) divided in the axial direction so that the nut 6 can be screwed onto the shaft portion 2. A ring-shaped elastic body 7 disposed on the outer peripheral portion of the nut 6, and a cylindrical body 8 including the nut 6 and the elastic body 7 and disposed on the outer peripheral portion of the elastic body 7 are provided.

  The shaft portion 2 is formed with a male screw having a thread height a in a spiral shape, the nut 6 is formed with a female screw having a screw thread height b in a spiral shape, and the bolt 4 and the nut 6 are, for example, a predetermined JIS. In conformity with the standard, the male screw of the shaft portion 2 and the female screw of the nut 6 are engaged with each other.

  The bolt 4 is preferably made of a special metal having a high tensile load resistance so that the bolt 4 is not easily broken when subjected to a large tensile load. The nut 6 is also preferably made of a special metal having a high tensile load resistance.

  The nut 6 is composed of, for example, four divided nuts 5. The number of the split nuts 5 is not limited to four as long as a gap can be formed between the split nut 5 and the adjacent split nut 5, and the number of split nuts 5 is not limited to four as long as it is two or more. But you can.

  The elastic body 7 is made of, for example, a rubber material, and the elastic body 7 is subjected to a certain amount of compression in the radial direction between the outer peripheral surface of the nut 6 and the inner peripheral surface of the cylindrical body 8 without receiving an external force in the axial direction. In this state, they are disposed without any gaps and do not slide on the cylinder 8 or the nut 6 without permission.

  The cylindrical body 8 has a hole portion 10 through which the shaft portion 2 penetrates in the center at one end portion in the axial direction, and a ring-shaped push portion 11 formed outside the hole portion 10. The pressing portion 11 is formed integrally with the circumferential portion of the cylindrical body 8, and the pressing portion 11 can press one end side of the nut 5 by receiving an external force. The cylinder 8 has a mounting portion 12 at the other end in the axial direction. The cylindrical body 8 is attached to another member that is used so that the bolt nut 1 functions by a screw or the like in the attachment portion 12.

  The head portion 3 is formed to have a larger diameter than the shaft portion 2, and the seat surface can come into contact with the push portion 11 without penetrating the hole portion 10.

  In the bolt nut 1, when an external force is applied between the cylinder 8 and the bolt 4 in the axial direction in which the cylinder 8 is separated from the head 3, and the magnitude of the external force is greater than a predetermined value, Such a phenomenon occurs.

  That is, in FIG. 1, for example, when the cylinder 8 is fixedly attached to another object by the mounting portion 12 and the bolt 4 is pulled rightward by a tensile external force having a magnitude greater than a predetermined value, the nut 6 and the elastic body 7 slides to the right and the right end of the nut 6 comes into contact with the pushing portion 11 to stop the nut 6 and the elastic body 7. Then, when the bolt 4 is pulled strongly against the nut 6 pressed against the pressing portion 11, the male screw of the shaft portion 2 releases the screwed relationship with the female screw of the nut 6, and the nut 6 has a hole diameter in the radial direction. Receives diameter expansion force to expand. Since the nut 6 is composed of a plurality of divided nuts 5 divided in the axial direction, a gap is generated between the plurality of divided nuts 5 and the hole diameter of the nut 6 is increased. Along with this, the thickness of the elastic body 7 sandwiched between the nut 6 and the cylindrical body 8 is compressed in the radial direction. In this state, the plurality of split nuts 5 have an increased diameter of the nut 6 so that the thread of the female thread of the nut 6 does not overlap with the thread of the male thread of the shaft portion 2 in the radial direction. Compressed radially. When the hole diameter of the nut 6 increases so that the thread of the female thread of the nut 6 does not overlap the thread of the male thread of the shaft portion 2 in the radial direction, the bolt 4 slides relative to the cylinder 8. As long as the tensile external force is equal to or greater than a predetermined value, the hole diameter of the nut 6 does not further increase against the force that the thickness of the elastic body 7 tries to return to the natural state, but the bolt 4 is a cylinder. The state in which the sliding movement with respect to 8 is possible is maintained. When the tensile external force becomes smaller than the predetermined value, the thickness of the elastic body 7 recovers in the radial direction, and the sliding movement of the bolt 4 with respect to the cylinder 8 stops.

  Next, with reference to FIG. 12, the case where an external force acts between the cylinder 8 and the bolt 4 in the axial direction in which the cylinder 8 approaches from the head 3 will be described.

  In this case, since the nut 6 does not contact the pushing portion 11, the nut 6 and the elastic body 7 move integrally with the bolt 4 in the cylindrical body 8 regardless of the magnitude of the acting external force.

  Here, the magnitude of the predetermined value mentioned above refers to the magnitude of the external force required to forcibly cancel the screwed state when the male screw of the bolt 4 and the female screw of the nut 6 are in a screwed state. The predetermined value depends on the thread shape and screw height of the male screw of the bolt 4 and the female screw of the nut 6, the degree of difficulty of elastic deformation of the elastic body 7, the number of split nuts 5 constituting the nut 6, and the like. It is decided.

  Next, the operation of the bolt nut 1 will be described with reference to FIGS.

  The bolt nut 1 is arranged so as to be spanned between a first wall body 14 and a second wall body 15 which are members that can move relative to each other. A through-hole 16 is formed in the first wall body 14, the bolt 4 passes through the through-hole 16 and is positioned in the cylinder body 8, and the seat surface of the head 3 is the second wall body of the first wall body 14. 15 is in contact with the opposite surface. The attachment portion 12 of the cylinder 8 is attached to the second wall 15, and the cylinder 8 is fixed to the second wall 15.

  2 and 3, a tensile load F acts in a direction away from each other between the first wall body 14 and the second wall body 15, and the magnitude of the tensile load F is the male thread of the bolt 4 and the female thread of the nut 6. It is assumed that the screw is smaller than a predetermined value required for forcibly canceling the screwed state. In this case, even if the nut 6 is pressed against the pressing portion 11 and a tensile load F is applied, the screwed state of the male screw of the bolt 4 and the female screw of the nut 6 is not canceled, and is a view of FIG. As shown in FIG. 3, no gap is generated between the split nuts 5.

  Next, FIGS. 4, 5 and 10 show a transient case in which the tensile load F + α starts to act between the first wall body 14 and the second wall body 15 in the direction away from each other. The part shown by B in FIG. 4 is enlarged and shown in FIG. The magnitude of the tensile load F + α is assumed to be larger than a predetermined value required for forcibly canceling the screwed state between the male screw of the bolt 4 and the female screw of the nut 6. The nut 6 is pressed through the pressing portion 11 and pressed with a tensile load F + α. In this case, since the tensile load F + α has just started, the screwed state of the male screw of the bolt 4 and the female screw of the nut 6 is partially canceled as shown in FIG. However, a screwed state is partially formed between the male screw of the bolt 4 and the female screw of the nut 6. Further, a gap 18 is starting to be generated between the split nuts 5 but is not sufficiently large. The distance between the first wall body 14 and the second wall body 15 is not changed.

  Next, in FIGS. 6, 7, and 11, the case where the tensile load F + α continuously acts in the direction away from each other between the first wall body 14 and the second wall body 15 is shown. A portion indicated by C in FIG. 6 is enlarged and shown in FIG. The tensile load F + α acts continuously and the transient phase is over. In this case, as shown in FIG. 11, the screwed state of the male screw of the bolt 4 and the female screw of the nut 6 is completely eliminated. Further, a gap 18 is formed between the split nuts 5 larger than the case shown in FIG. As shown in FIG. 6, the first wall body 14 moves in a direction away from the second wall body 15. Here, in FIG. 11, the state in which the screwed state of the male screw of the bolt 4 and the female screw of the nut 6 is completely eliminated is shown exaggerated with a large gap between the male screw of the bolt 4 and the female screw of the nut 6. However, in practice, once the screwed state is canceled, the gap between the male screw of the bolt 4 and the female screw of the nut 6 does not become larger even if the tensile load F + α is further continued.

  Next, in FIGS. 8 and 9, the magnitude of the external force acting in the direction away from each other between the first wall 14 and the second wall 15 is changed from the tensile load F + α shown in FIG. The case where it decreases is shown. In this case, since the tensile load F is smaller than the predetermined value, the threaded state of the male screw of the bolt 4 and the female screw of the nut 6 returns. Further, the thickness of the elastic body 7 is recovered and the gap 18 formed between the split nuts 5 is eliminated. And as shown in FIG. 8, the space | interval of the 1st wall body 14 and the 2nd wall body 15 is continuously maintained in the state shown in FIG.

  The bolt 4 is not limited to the shaft 2 and the head 3 being integrally formed. The shaft 2 is composed of a shaft rod having a male screw, and the head 3 is separate from the shaft 2. It may be a mounting nut formed as a body and having an internal thread, and the mounting nut may be screwed onto the shaft rod.

  Next, with reference to FIG. 13, an embodiment of the expansion joint will be described as one application example of the bolt nut 1. FIG. 13 shows the upper half with respect to the central axis.

  The expansion joint 20 connects the first pipe 21 and the second pipe 22, and the expansion joint 20 includes a sleeve 24 spanned between each end of the first pipe 21 and the second pipe 22, and the sleeve 24. For example, an O-ring-shaped first seal 25 that seals the inner peripheral surface and the outer peripheral surface of the first pipe 21, and an O-ring-shaped first seal that seals the inner peripheral surface of the sleeve 24 and the outer peripheral surface of the second pipe 22, for example. Two seals 26 are provided.

  In addition, the expansion joint 20 includes a stopper 28 for limiting the first pipe 21 and the second pipe 22 so as not to separate from each other beyond a predetermined length L in the axial direction. The stopper 28 includes a first reference portion 29 provided on the outer peripheral portion of the first pipe 21, a second reference portion 30 provided on the outer peripheral portion of the second pipe 22, the first reference portion 29, and the second reference portion. And a bolt and nut 32 spanned between 30 and 30. The expansion joint 20 is provided with a plurality of stoppers 28 around the axis, for example, four every 90 °.

  A plurality of first reference parts 29 and second reference parts 30 are provided on the outer peripheral surfaces of the first pipe 21 and the second pipe 22 at equal intervals, and a plurality of first reference parts 29 and second reference parts are provided. A plurality of stoppers 28 equivalent to 30 are provided.

  The bolt nut 32 basically has the same configuration as the bolt nut 1 shown in FIG. 1 and the like, and includes a bolt 35 having a shaft portion 33 and a head portion 34, and a plurality of bolts as shown in FIG. A nut 36 that can be screwed into the shaft portion 33 by combining the divided nuts divided in the axial direction, a ring-shaped elastic body 37 disposed on the outer peripheral portion of the nut 36, and the nut 36 and the elastic body 37 are included to be elastic. And a cylindrical body 38 disposed on the outer peripheral portion of the body 37. The cylindrical body 8 is formed with a ring-shaped pushing portion 38a at one end portion in the axial direction.

  The bolt 35 is different from the bolt 4 shown in FIG. 1 and the like, in which the shaft portion 33 and the head portion 34 are formed separately, and the shaft portion 33 is formed of a shaft rod formed with a male screw, and the head portion 3 is a female member. It is composed of a mounting nut formed with a screw. The head portion 34 is screwed into a portion where the shaft portion 33 penetrates and penetrates the hole formed in the first reference portion 29, and the bolt 35 including the shaft portion 33 and the head portion 34 is connected to the first reference portion 29. It is fixed to.

  A hole is formed in the second pipe 22, and a shaft bar 39 having a male screw formed in the hole is fixed by a mounting nut 40. The end of the shaft bar 39 opposite to the mounting nut 40 is screwed into a female screw formed at the end of the cylindrical body 38 and is fixed by a mounting nut 41. In this manner, the bolt nut 32 is attached to the first reference portion 29 by the head 34 and the shaft portion 33 as a mounting nut on one side, and is connected to the second reference portion 30 by the shaft rod 39 and the mounting nut 40 on the other side. It is attached.

  Further, a stop member 43 is attached to the other end of the shaft portion 33, and even when the shaft portion 2 slides most toward the first reference portion 29 side, the stop member 43 is the shaft of the cylindrical body 38. The shaft 33 is prevented from being removed from the cylindrical body 38 so that it cannot be removed from the hole through which the portion 33 passes.

  The cylinder 38 has a length L roughly, and a portion of the shaft portion 35 having a length of about L is accommodated in the cylinder 38.

  When a tensile load of a predetermined value or more is applied between the first pipe 21 and the second pipe 22 in a direction away from each other in the axial direction, first, the nut 36 and the nut 36 and the shaft 36 are displaced in the axial direction. The elastic body 737 contacts the pushing portion 38a, and the shaft portion 33 slides with respect to the nut 36 due to the action of a tensile load of a predetermined value or more. When the tensile load becomes smaller than the predetermined value, the nut 36 of the shaft portion 33 is moved. The sliding movement with respect to stops. When the state where the tensile load is a predetermined value or more continues further, the sliding movement of the shaft portion 33 with respect to the nut 36 stops when the stop member 43 at the end of the shaft portion 33 abuts against the nut 36 in the cylindrical body 38, In this state, the axial interval between the first pipe 21 and the second pipe 22 extends by a length L.

  According to the present embodiment, when the piping device including the first piping 21, the second piping 22, and the expansion joint 20 is buried in the ground and receives an external force of a predetermined value or more due to the influence of an earthquake or the like, the stopper Since 28 includes a bolt nut 32, the axial distance between the first pipe 21 and the second pipe 22 extends by a length L without the expansion joint 20 being detached from the first pipe 21 and the second pipe 22. Is possible.

1, 32 Bolt nut 2, 33 Shaft portion 3, 34 Head 4, 35 Bolt 5 Split nut 6, 36 Nut 7, 37 Elastic body 20 Expansion joint 21 First piping 22 Second piping 26 Stopper 29 First reference portion 30 Second reference part 43 Stop member

Claims (8)

A bolt having a shaft and a head;
A plurality of divided nuts divided in the axial direction and nuts that can be screwed into the shaft part;
A ring-shaped elastic body disposed on the outer periphery of the nut;
A cylindrical body including the nut and the elastic body and disposed on an outer peripheral portion of the elastic body;
With
When the external force acting in the axial direction in which the cylindrical body is separated from the head between the cylindrical body and the bolt is greater than or equal to a predetermined value, the cylindrical body and the bolt together with the nut and the elastic body Bolts and nuts that slide in the axial direction with respect to. When the external force is greater than or equal to the predetermined value, a gap is generated between the plurality of split nuts, the hole diameter of the nut is enlarged, and the thickness of the elastic body is compressed in the radial direction. The bolt nut according to claim 1 characterized by things. 2. The bolt and nut according to claim 1, wherein when the external force is smaller than the predetermined value, the thickness of the elastic body recovers in a radial direction and the sliding movement stops. An expansion joint connecting the first pipe and the second pipe,
A stopper for limiting the first pipe and the second pipe so as not to be separated beyond a predetermined length in the axial direction;
The stopper is
A first reference portion provided on an outer peripheral portion of the first pipe;
A second reference portion provided on an outer peripheral portion of the second pipe;
A bolt and nut spanned between the first reference portion and the second reference portion;
The bolt and nut
A bolt having a shaft and a head;
A plurality of nuts divided in the axial direction are combined, and a nut that can be screwed to the shaft portion;
A ring-shaped elastic body disposed on the outer periphery of the nut;
A cylindrical body including the nut and the elastic body and disposed on an outer peripheral portion of the elastic body;
With
When the external force acting in the axial direction in which the cylindrical body is separated from the head between the cylindrical body and the bolt is greater than or equal to a predetermined value, the cylindrical body and the bolt together with the nut and the elastic body An expansion joint characterized by sliding in the axial direction with respect to. The head is supported by the first reference portion;
The expansion joint according to claim 4, wherein a portion of the cylindrical body on the side opposite to the head is supported by the second reference portion. The expansion joint according to claim 5, wherein the portion of the cylindrical body is supported by the second reference portion via an attachment member attached to the second reference portion. The shaft portion of the bolt is a shaft rod formed with a male screw, and the head portion of the bolt is a mounting nut that is formed separately from the shaft rod and is screwed to the shaft rod. The expansion joint according to claim 5. The expansion joint according to claim 5, further comprising a stop member that prevents the shaft portion from coming out of the cylindrical body at an end portion of the shaft portion opposite to the head portion.

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