JP2016075294A - Pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipe joint capable of stopping loosening between a joint body and a ball head lock nut while the tightening between the joint body and the ball head lock nut is surely possible, in the pipe joint in which a pipe is connected by tightening the joint body and the ball head lock nut.SOLUTION: A pipe joint comprises: a joint body including a receptacle for receiving a pipe; a seal member attached to the receptacle for sealing with the pipe; a ball head lock nut 3 screwed to the joint body and having at least one engaging piece formed in an end outer periphery on the side of the joint body so as to protrude in a radial direction; and a nut loosening stop member 5 which is diametrically, expandably and contractibly attached to the joint body, and is engaged to the engaging piece so as to prevent the loosening the ball head lock nut when the tightening between the joint body and the ball head lock nut is completed. When the ball head lock nut is tightened to the joint body while the ball head lock nut is pushing and expanding the nut loosening stop member, the height of the engaging piece is provided such that the outer diameter dimension of the nut loosening stop member is to be smaller than the minimum dimension of a shank of the joint body.SELECTED DRAWING: Figure 6

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. 7, Patent Document 1 includes a joint body 20 and a cap nut 30 having a tapered portion sandwiching a flare portion formed at an end portion of a pipe P. 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.

  In view of this, the present applicant has invented a pipe joint that can surely mechanically connect pipes and can prevent loosening of the joint body and the cap nut after connection (Japanese Patent Application No. 2013-204782). According to this pipe joint, when the nut locking member 5 is attached to the joint body 2 and the cap nut 3 is tightened against the joint body 2, it is formed on the outer peripheral portion of the end portion of the cap nut on the joint body side. Since the locking piece 33 is locked to the nut loosening prevention member, the cap nut 3 can be prevented from loosening from the joint body 2.

JP 2008-38924 A

  According to this pipe joint, loosening of the cap nut can be reliably prevented as long as the joint body and the cap nut are tightened. When the outer diameter of the nut locking member becomes large, the nut locking member may interfere with a tool such as a spanner, resulting in inconvenience in construction.

  The present invention has been made in view of these problems, and the nut loosening prevention member can be surely mechanically connected to the tool without interfering with the tool during construction, and the joint body and the bag. It is an object of the present invention to provide a pipe joint that can prevent a nut from loosening.

In order to achieve the above object, a pipe joint of the present invention includes a joint main body having a receiving port for receiving a pipe, a seal member attached to the receiving port and sealing the pipe, and screwed into the joint main body to be engaged with the joint main body. A cap nut formed with at least one locking piece projecting radially on the outer periphery of the side end portion, and the engagement nut is attached to the joint body so that the diameter of the joint can be expanded and contracted. A pipe joint provided with a nut loosening prevention member that is locked to a stopper piece and prevents the cap nut from loosening,
The height of the locking piece is such that when the cap nut is tightened to the joint body while expanding the nut locking member, the outer diameter of the nut locking member is the smallest of the body part of the joint body. It is provided so that it may become smaller than an outer diameter dimension.
According to this pipe joint, when the cap nut is tightened to the joint main body and the pipe is connected, the nut loosening prevention member is prevented from protruding outward in the radial direction of the body portion of the joint main body. There is no interference with tools such as.

  Further, in the pipe joint of the present invention, it is desirable that a portion of the base of the locking piece has a thin portion that is rolled in the radial direction. By providing the relief part, the outer diameter dimension of the nut locking member in a state before being expanded can be designed to be small, so that the height of the locking piece can be suppressed to the minimum necessary height, As a result, when the nut locking member is pushed and expanded by the locking piece, the nut locking member is further prevented from protruding outward in the radial direction of the body portion of the joint body.

  According to the pipe joint of the present invention, the height of the locking piece formed at the end of the cap nut on the joint main body side is such that the cap nut is tightened to the joint main body while expanding the nut locking member. Since the outer diameter of the nut locking member is smaller than the minimum outer diameter of the body of the joint body, the nut locking member can be used when tightening the joint body and the cap nut. Can be securely tightened without interfering with the tool, and the joint body and the cap nut can be securely prevented from loosening.

It is sectional drawing of the pipe joint of embodiment of this invention. It is a figure which shows the coupling main body in embodiment of this invention. It is a figure which shows the cap nut in embodiment of this invention. It is a perspective view of the nut locking member in an embodiment of the invention. It is sectional drawing which shows the use condition of the pipe joint of embodiment of this invention. It is a side view which shows the relationship between the cap nut in this invention, and a nut loosening prevention member. It is sectional drawing which shows the pipe joint of a prior art.

The pipe joint of embodiment of this invention is demonstrated in order.
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, FIG. 6, 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. FIG. 6A shows a state where the locking piece is accommodated in the second hole, and FIG. 6B shows a state where the locking piece pushes and expands the nut loosening prevention member. In order to facilitate understanding, in FIG. 6, the joint main body is omitted, and the nut locking member is shown translucently.
(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 fits in the second hole 52 of the nut loosening prevention 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 52 to the second hole 52 adjacent in the circumferential direction one after another. On the other hand, since there is no inclination in the direction opposite to the tightening direction of the locking piece 33 and the locking portion 332 is formed to be locked to the second hole portion, it has moved to the second hole portion 52 adjacent in the tightening direction. The locking piece 33 does not return to the original second hole 52. 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 52. 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.

  At this time, as shown in FIG. 6A, in a state where the locking piece 33 is housed in the second hole 52 between the nut loosening prevention member 5 that is expanded and the cap nut 3, A gap of the thin portion 35 is formed in the radial direction at the base portion opposite to the fastening direction of the locking piece 33. By providing the thinning portion 35 at the base of the locking piece in this way, the outer diameter of the nut locking member 5 in the state of FIG. The outer diameter can be kept small. As shown in FIG. 6 (b), the height of the locking piece 33 is such that when the cap nut 3 is tightened to the joint body while expanding the nut locking member 5, The diameter D is provided so as to be smaller than the minimum outer diameter of the nut (the width across flats D1 of the hexagon). In FIG. 6B, the joint main body is omitted, but the minimum outer diameter of the body of the joint main body is the same as the minimum outer diameter of the nut.

1: Pipe Fitting 2: Fitting Main Body 21: Channel, 22 Receiving Port, 221: Packing Groove, 222: Tapered Part 23: Male Thread Part, 24: Body Part 25: Holding Convex Part 3: Cap Nut 31: Tapered Part, 32 : Female thread part, 33: locking piece 331: inclined surface, 332: locking part, 333: chamfering 34: locking groove 35: thinning part 4: seal member 5: nut loosening prevention member 51: first hole part 52 : Second hole P: Tube

Claims (2)

A joint body having a receiving port for receiving a pipe; a seal member mounted on the receiving port for sealing with the pipe; and at least one latch threadedly engaged with the joint body and projecting radially on the outer periphery of the end of the joint body side A cap nut formed with a piece, and a nut that is attached to the joint main body so as to be able to expand and contract, and is locked to the locking piece when the fastening of the joint main body and the cap nut is completed to prevent the cap nut from loosening. A pipe joint comprising a locking member,
The height of the locking piece is such that when the cap nut is tightened to the joint body while expanding the nut locking member, the outer diameter of the nut locking member is the smallest of the body part of the joint body. A pipe joint characterized by being provided to be smaller than an outer diameter dimension. 2. The pipe joint according to claim 1, wherein a portion of a base of the locking piece is provided with a thin portion that is wound in a radial direction.