JP2015068447A - Pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipe joint capable of surely performing mechanical connection of a pipe, and capable of preventing loosening of a cap nut at low cost even in a case where variation in a position at which the cap nut is completely fastened to a joint body occurs.SOLUTION: A pipe joint 1 includes: a joint body 2 having a socket for receiving a pipe; a cap nut 3 screwed into the joint body; and a seal member 4 mounted to the socket and sealing the pipe. The pipe joint also includes a nut loosening prevention member 5 that allows only relative movement between the joint body 2 and the cap nut 3 in a fastening direction when the cap nut 3 is fastened to the joint body 2.

Description

  The present invention relates to a mechanical connection type pipe joint used for connecting pipes for water supply and hot water supply, and more particularly to a structure for preventing loosening between a cap nut and a joint body in a mechanical connection type pipe joint.

  Conventionally, stainless steel pipes for general piping have been used for piping for indoor water supply and hot water supply. As a connection method of stainless steel pipes for general piping, mechanical connection type pipe joints that connect pipes by tightening cap nuts and joint bodies are widely used. As this type of pipe joint, for example, as shown in FIG. 14, Patent Literature 1 includes a joint body 20 having a tapered portion sandwiching a flare formed at the end of a pipe P and a cap nut 30, A pipe joint 10 for connecting a pipe P by tightening a main body 20 and a cap nut 30 is disclosed.

  According to this type of pipe joint, the pipe can be connected by simply tightening the joint body and the cap nut with a predetermined tightening torque with the cap nut attached to the end of the pipe where the flare is formed. In addition, there is an advantage that the construction of the pipe is simple with respect to the connection of the pipe by the screw joint. However, when an external force such as strong vibration is applied to the piping and a force in the direction that loosens the connection is applied to the cap nut, the connection between the fitting body and the cap nut is loosened, the connection between the pipe and the fitting is disconnected, Leakage may occur.

  Therefore, Patent Document 1 includes a ring member 40 that is reduced in diameter by a circumferential groove formed in the joint body 20, and a locking groove 301 that is hooked on the ring member 40 on the inner surface of the end of the cap nut 30. It is described that the locking groove 301 and the ring member 40 fit together to prevent the cap nut 30 from loosening. According to this structure for preventing looseness of the cap nut, as long as the ring member and the locking groove are fitted, the cap nut can be mechanically and reliably prevented from loosening.

JP 2008-38924 A

  However, the pipe joint described in Patent Document 1 has the following problems to be solved. The cap nut is set so that the ring member and the locking groove fit together when a predetermined length is tightened on the joint body. For example, the predetermined length is caused by a variation in the thickness of the tube. It is possible that it cannot be tightened. In this case, since the ring member and the locking groove are not fitted, the function of preventing the cap nut from being loosened is not achieved. Conversely, it is conceivable that the connection between the pipe and the joint is insufficient even though the cap nut is tightened to a predetermined length. In this case, the function of preventing the cap nut from loosening is achieved, but the connection between the pipe and the joint is not reliably performed. It is possible to solve these problems with the cap nut locking structure by increasing the dimensional accuracy of each member, but this also leads to an increase in manufacturing cost.

  The present invention has been made in view of these problems, and is a case where the mechanical connection of the pipe can be reliably performed, and the position where the tightening of the cap nut with respect to the joint body has been varied occurs. However, it is an object of the present invention to provide a pipe joint that can realize the prevention of loosening of the cap nut at a low cost.

In order to achieve the above object, a pipe joint according to the present invention includes a joint main body having a receiving port for receiving a pipe, a cap nut screwed into the joint main body, and a seal member that is attached to the receiving port and seals the pipe. In a pipe joint having
A nut loosening prevention member that allows only relative movement of the joint body and the cap nut in the tightening direction when the cap nut is tightened with respect to the joint body is provided.
According to this pipe joint, when the cap nut is fastened to the joint main body and the pipe is connected, the joint main body and the cap nut are relatively moved only in the tightening direction. In other words, the joint body and the cap nut do not move relative to each other in the direction in which the tightening is loosened.

In the pipe joint of the present invention, the nut locking member is
An annular plate-like member provided so as to be elastically expandable / contractable,
A first hole that fits into a holding projection protruding from the outer periphery of the joint body;
When the cap nut is tightened, a plurality of second holes to which the locking pieces formed on the cap nut are locked,
It can be set as the member provided with.
According to this pipe joint, the nut loosening prevention member is held by the joint main body with the first hole fitted into the holding convex part. Further, the cap nut is fastened to the joint main body while the locking piece moves only in the tightening direction of the cap nut in the plurality of second holes formed in the circumferential direction in the nut loosening prevention member.

In the pipe joint of the present invention, the nut locking member is
An annular member provided to be elastically expandable and contractible,
A first locking part that fits into a holding convex part protruding from the outer peripheral part of the joint body;
When the cap nut is tightened, a plurality of second locking portions that are locked by locking pieces formed on the cap nut;
It can be set as the member provided with.
According to this pipe joint, the nut locking member is held by the joint body with the first locking part fitted to the holding convex part. Further, the cap nut is fastened to the joint body while a plurality of locking pieces formed on the cap nut are moved in the tightening direction to a plurality of second locking portions formed in the circumferential direction on the nut locking member.

In the pipe joint of the present invention, the nut locking member is
An annular main body fixed by being press-fitted into an annular groove formed in the joint body;
A restricting piece provided on the annular main body, and a locking piece formed on the cap nut when the cap nut is tightened, is movable only in the tightening direction of the cap nut,
It can be set as the member provided with.
According to this pipe joint, the nut locking member is held by the annular main body portion with respect to the joint main body. Further, the cap nut is restricted by the restriction piece provided in the annular main body in the loosening direction, and is tightened to the joint main body while moving only in the tightening direction.

  According to the pipe joint of the present invention, the cap nut is provided with a nut loosening prevention member that only allows relative movement in the tightening direction of the joint main body and the cap nut. Even if there is a variation in the tightening completion position, the pipe can be reliably mechanically connected, and the cap nut can be prevented from loosening at low cost.

It is sectional drawing of the pipe joint of 1st Embodiment. It is a figure which shows the coupling main body in 1st Embodiment. It is a figure which shows the cap nut in 1st Embodiment. It is a perspective view of the nut locking member in a 1st embodiment. It is sectional drawing which shows the use condition of the pipe joint of 1st Embodiment. It is sectional drawing of the pipe joint of 2nd Embodiment. It is a figure which shows the coupling main body in 2nd Embodiment. It is a figure which shows the cap nut in 2nd Embodiment. It is a perspective view of the nut locking member in a 2nd embodiment. It is sectional drawing which shows the use condition of the pipe joint of 2nd Embodiment. It is sectional drawing which shows the coupling main body in 3rd Embodiment. It is a perspective view of the nut loosening prevention member in a 3rd embodiment. It is a perspective fragmentary sectional view which shows the state which assembled | attached the coupling main body and the nut locking member in 3rd Embodiment. It is sectional drawing which shows the pipe joint of a prior art.

The pipe joints of the first to third embodiments according to the present invention will be described in order.
(First embodiment)
FIG. 1 is a cross-sectional view of the pipe joint 1. The left side of the figure shows a state where the pipe P is connected, and the right side of the figure shows a state where each member is disassembled. As shown in FIG. 1, the pipe joint 1 includes a joint body 2, a cap nut 3 that is fastened to the joint body 2, a seal member 4 that seals the joint body 2 and the pipe P, and a nut loosening prevention member 5. The pipe P is mechanically connected by tightening the joint body 2 and the cap nut 3.

  2 shows the joint body 2, FIG. 2 (a) is a sectional view of the joint body, and FIG. 2 (b) is a perspective view of the joint body. As shown in FIG. 2, the joint body 2 has a hollow shape having a flow path 21 through which a fluid flows. The outer peripheral portion is formed with a receiving port 22, a male screw portion 23, and a body portion 24 in order from the end portion. The receiving port 22 includes a packing groove 221 in which the seal member 4 is mounted and a tapered portion 222 that extends from the packing groove 221 toward the back side, and receives the end of the pipe P when the pipe P is connected. The male screw portion 23 is formed at the rear portion of the tapered portion 222, and the cap nut 3 is tightened when the pipe P is connected. The body 24 is formed in, for example, a hexagonal shape having a plurality of opposing two surfaces having a predetermined two-surface width so that the tube 24 can be held by a tool such as a spanner when the pipe P is connected. A plurality of holding convex portions 25 are formed in the circumferential direction at the end of the body portion 24 on the male screw 23 side.

  3 shows the cap nut 3, FIG. 3 (a) is a side view of the cap nut viewed from the joint body side, FIG. 3 (b) is a half sectional view of the cap nut viewed from the front, and FIG. It is a perspective view of a cap nut. As shown in FIG. 3, the cap nut 3 has a tapered portion 31 and a female screw portion 32 formed on the inner peripheral portion. The taper part 31 is formed so as to expand from the end part toward the back side, and when connecting the pipe P, the flare part formed at the end part of the pipe P is connected to the taper part 222 of the joint body 2. Press towards. The female thread portion 32 is formed toward the end opposite to the tapered portion 31 and is fastened to the male thread portion 23 of the joint body 2 when the pipe P is connected. The outer periphery of the cap nut 3 is formed in, for example, a hexagonal shape having a plurality of opposing two surfaces having a predetermined two-surface width to be held by a tool, like the joint body. Further, a plurality of locking pieces 33 and locking grooves 34 are formed in the circumferential direction at the outer peripheral end of the cap nut. The locking piece 33 is formed with an inclined surface 331 that is inclined in the direction of tightening the cap nut, and an engaging portion 332 that is not inclined on the opposite side of the inclined surface. The locking piece 33 is chamfered 333 at the end surface. The material of the joint body 2 and the cap nut 3 is, for example, austenitic stainless cast steel SCS13.

  As shown in FIG. 1, the seal member 4 is an annular member attached to a packing groove 221 formed at the end of the joint body 2, and when the pipe P is connected, the inner surface of the pipe P and the joint body Seal between the two. As the material of the seal member 4, a rubber material is used, such as nitrile butadiene rubber (NBR) excellent in heat resistance and other mechanical properties, and fluorine rubber (FKM) excellent in heat resistance.

  FIG. 4 is a perspective view of the nut locking member 5. As shown in FIG. 4, the nut loosening prevention member 5 is a plate-like member formed in an annular shape in which a part in the circumferential direction is cut away. The nut locking member 5 has a plurality of first holes 51 and a plurality of second holes 52 formed in the circumferential direction. The first hole 51 is a through-hole penetrating in the thickness direction so that the holding convex portion 25 formed on the outer peripheral portion of the joint body 2 is fitted. Similarly to the first hole portion, the second hole portion 52 is also formed as a through hole penetrating in the thickness direction. The nut loosening prevention member 5 is provided elastically so as to be able to expand and contract, and is attached to the joint body 2 so that the first hole 51 fits the holding convex part 25 of the joint body 2. As a material of the nut locking member 5, a plate material having elasticity such as spring steel or stainless steel is used, and a plate material formed by punching the first hole 51 and the second hole 52 is formed into a ring shape. Is done.

Next, with reference to FIG. 5, the connection procedure of the pipe P using the pipe joint 1 is demonstrated. FIG. 5A shows an initial state of tightening the cap nut, and FIG. 5B shows a state where the tightening of the cap nut is completed.
(1) Prepare a joint body 2 to which a seal member 4 and a nut locking member 5 are attached, and a cap nut 3 attached to an outer peripheral portion of a pipe P whose end is flared. As shown in a), the male thread part 23 of the joint body 2 and the female thread part 32 of the cap nut 3 are temporarily tightened by hand tightening.
(2) When the tightening of the cap nut 3 is further advanced, the end portion of the nut locking member 5 is elastically expanded at the chamfered portion of the locking piece 33 formed at the end portion of the cap nut 3, The locking piece 33 is accommodated in the second locking hole of the nut locking member 5.
(3) Further, the tightening of the cap nut 3 is advanced, and the flared end portion of the pipe P is firmly sandwiched between the tapered portion 31 of the cap nut 3 and the tapered portion 222 of the joint body 2, and the sealing member is Fully compressed to complete the connection of the pipe P. When the cap nut 3 is tightened, the locking piece 33 formed at the end of the cap nut 3 elastically pushes and expands the nut locking member 5 with an inclined surface 331 (see FIG. 3) inclined in the tightening direction. The ratchet moves from the second hole part to the second hole part adjacent in the circumferential direction one after another. On the other hand, there is no inclination in the direction opposite to the tightening direction of the locking piece 33, and the locking portion 332 that locks in the second hole portion is formed. The stop piece 33 does not return to the original second hole. In other words, the cap nut 3 can be moved only in the tightening direction. When the cap nut 3 is tightened until the connection of the pipe P is completed, the locking piece 33 formed on the cap nut 3 is locked in the second hole. Therefore, after the connection of the pipe P is completed, the cap nut 3 is securely prevented from being loosened by the locking member 5 at that position. Therefore, even if an external force in the direction of loosening the cap nut 3 acts, the cap nut 3 Will not loosen.

(Second Embodiment)
FIG. 6 is a cross-sectional view of the pipe joint 1a. The left side of the figure shows a state where the pipe P is connected, and the right side of the figure shows a state where each member is disassembled. The pipe joint 1a of the second embodiment is the same as the pipe joint of the first embodiment except for the structure of the nut locking member 5a and the parts of the joint body 2a and the cap nut 3a related thereto. Therefore, the same reference numerals are assigned and the description thereof is omitted.
As shown in FIG. 6, the pipe joint 1 a includes a joint body 2 a, a cap nut 3 a that is fastened to the joint body 2, a seal member 4 that seals the joint body 2 a and the pipe P, and a nut loosening prevention member 5 a.

  FIG. 7 shows the joint main body 2a, and the joint main body 2a has a plurality of holding convex portions 25a formed in the circumferential direction at the rear portion of the male screw portion 23.

  8 shows the cap nut 3a, FIG. 8 (a) is a side view of the cap nut viewed from the joint body side, and FIG. 8 (b) is a perspective view of the cap nut. The cap nut 3a has a plurality of saw-tooth shaped locking pieces 33a having an inclined surface 331a inclined toward the tightening direction (the direction of arrow A in the figure) on the outer surface of the end portion and a locking portion 332a in the opposite direction. Are formed at predetermined intervals in the circumferential direction. The locking piece 33a has a chamfer 333a at its end face.

  FIG. 9 shows a perspective view of the nut locking member 5a. As shown in FIG. 9, the nut locking member 5a is formed in an annular shape in which a part in the circumferential direction is cut out, and a holding convex portion 25a formed in the joint body 2a is formed on the inner peripheral portion thereof. A plurality of first locking portions 51a in which the holding convex portions 25a fit and fit are formed in the circumferential direction at portions corresponding to. Further, a plurality of troughs 521a in which the locking pieces 33a of the cap nut 3a are accommodated at the end opposite to the first locking portions 51a, and the inclined surfaces of the locking pieces 33a are expanded by tightening the nuts. A second locking portion 52a composed of a plurality of peak portions 522a is formed.

Next, with reference to FIG. 10, the connection procedure of the pipe P using the pipe joint 1a is demonstrated. FIG. 10A shows an initial state of tightening the cap nut 3a, and FIG. 10B shows a state where the tightening of the cap nut 3a is completed.
(1) A joint body 2a to which a seal member 4 and a nut locking member 5a are attached, and a cap nut 3a attached to the outer peripheral portion of the pipe P whose end is flared are prepared. As shown in a), the male thread part 23 of the joint body 2a and the female thread part 32 of the cap nut 3a are temporarily tightened by hand tightening.
(2) When the tightening of the cap nut 3a is further advanced, the locking piece 33a formed at the end portion of the cap nut 3a moves to move the peak portion 521a by the inclined surface 331a and moves beyond the peak portion 521a. It moves to the adjacent valley part 522a. (See Figs. 8 and 9)
(3) Further, the tightening of the cap nut 3a is advanced, and the flared end of the pipe P is firmly sandwiched between the tapered portion 31 of the cap nut 3a and the tapered portion 222 of the joint body 2a, and the sealing member is Fully compressed to complete the connection of the pipe P. When tightening the cap nut 3a, the locking piece 33a formed at the end of the cap nut 3 pushes and widens the peak portion 521a with the inclined surface 331a inclined in the tightening direction, and elastically expands the nut loosening prevention member 5a. It moves one after another from the valley 522a to the valley 522a adjacent in the circumferential direction in a ratchet manner. On the other hand, there is no inclination in the direction opposite to the tightening direction of the locking piece 33a, and a locking portion 332a that locks the peak portion 521a is formed, so that the locking piece that has moved to the valley 522a adjacent to the tightening direction. 33a never returns to the original valley 522a. When the cap nut 3a is tightened until the connection of the pipe P is completed, the locking piece 33a formed on the cap nut 3a is locked to the peak portion 521a. Thus, also in the present embodiment, as in the first embodiment, the cap nut after the pipe P is connected can be prevented from loosening.

(Third embodiment)
The pipe joint 1b of the third embodiment is different from the other embodiments in the structure of the nut locking member 5b and the structure of the joint body 2b related thereto, but the structure of the cap nut is the same as that of the second embodiment. Since the other parts are the same as the pipe joint of the first embodiment, the same parts are denoted by the same reference numerals and the description thereof is omitted.

  FIG. 11 is a sectional view of the joint body 2b. As shown in FIG. 11, the joint main body 2b is formed with an annular groove portion 241b for holding a cap nut locking member 5b, which will be described later, on the surface of the barrel portion 24b on the screw side.

  FIG. 12 is a partial cross-sectional view in which a part of the nut locking member 5b in the circumferential direction is cut away. As shown in FIG. 12, the nut locking member 5b includes an annular main body portion 51b, an annular annular holding portion 52b connected to the annular main body portion 51b, and a regulation piece 53b held by the annular holding portion 52b. Yes. The annular main body 51b is formed with a single ridge 511b for press-fitting and holding in the annular groove 241b of the joint body 2b. Four slits 521b are formed at the end of the annular holding portion 52b, and a regulating piece 53b is supported and fixed to the slit 521b. The regulating piece 53b is a plate-like body that can be elastically deformed in the circumferential direction of the annular holding portion 52b. The annular main body 51b and the annular holding part 52b are made of a metal material, and are made of, for example, austenitic stainless cast steel such as SCS13. The restricting piece 53b is formed of a metal plate having elasticity such as spring steel. In this embodiment, four slits 521b and restricting pieces 53b are provided, but the number is not limited to this. The slit 521b and the restricting piece 53b can be provided at N places (N is a natural number of 1 or more).

  As shown in FIG. 13, the joint main body 2b and the nut loosening prevention member 5b are integrally fixed by press-fitting the annular main body 51b of the nut loosening prevention member into the annular groove 241b of the joint main body 2b. Since the single rib portion 511b is formed on the annular main body 51b, the joint main body 2b and the nut locking member 5b are firmly fixed.

  In the pipe joint 1b of the third embodiment, the pipe P is connected as follows. When the cap nut 3a is tightened to the joint body 2b, the locking piece 33a at the end of the cap nut 3a is tightened while deforming the regulating piece 53b in the circumferential direction. At this time, as for the locking piece 33a, the adjacent locking piece 33a passes the regulation piece 53b one after another. When the tightening of the cap nut is completed until the connection of the pipe P is completed, the restriction piece 52b is locked to the locking portion 332a of the locking piece 33a. At this time, since the locking portion 332a does not have an inclination, the regulating piece 52b does not move in the direction opposite to the tightening. Thus, also in the present embodiment, similarly to the first and second embodiments, the cap nut after the pipe P is connected can be prevented from loosening.

  In addition, the pipe joint which concerns on this invention is not limited to the 1st-3rd embodiment mentioned above, In the range which does not deviate from the summary of invention, it can change. For example, the nut locking member can be provided not on the joint body side but on the cap nut side.

1, 1a, 1b: Pipe joint 2, 2a, 2b: Joint body 21: Flow path, 22 receptacle, 221: Packing groove, 222: Tapered part 23: Male thread part, 24, 24b: Body part, 241b: Annular groove part 25, 25a: holding convex part 3, 3a, 3b: cap nut 31: taper part, 32: female thread part, 33, 33a, 33b: locking piece 331, 331a: inclined surface, 332, 332a: locking part, 333, 333a: chamfer 34: locking groove 4: seal member 5, 5a, 5b: nut loosening prevention member 51: first hole portion, 51a: first locking portion 51b: annular main body portion,
52: second hole portion, 52a: second locking portion, 52b annular holding portion,
521a: valley portion, 522a: mountain portion 521b: slit, 53b: regulating piece P: tube

Claims (4)

In a pipe joint having a joint body having a receiving port for receiving a pipe, a cap nut screwed into the joint body, and a seal member attached to the receiving port and sealing the pipe,
A pipe joint comprising a nut locking member that allows only relative movement of the joint body and the cap nut in the tightening direction when the cap nut is tightened with respect to the joint body. The nut locking member is
An annular plate-like member provided so as to be elastically expandable / contractable,
A first hole that fits into a holding projection protruding from the outer periphery of the joint body;
When the cap nut is tightened, a plurality of second holes to which the locking pieces formed on the cap nut are locked,
The pipe joint according to claim 1, comprising: The nut locking member is
An annular member provided to be elastically expandable and contractible,
A first locking part that fits into a holding convex part protruding from the outer peripheral part of the joint body;
When the cap nut is tightened, a plurality of second locking portions that are locked by locking pieces formed on the cap nut;
The pipe joint according to claim 1, comprising: The nut locking member is
An annular main body fixed by being press-fitted into an annular groove formed in the joint body;
A restricting piece provided on the annular main body, and a locking piece formed on the cap nut when the cap nut is tightened, is movable only in the tightening direction of the cap nut,
The pipe joint according to claim 1, comprising:

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