JP6300067B2 - Pipe fitting - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a mechanical connection type pipe joint used for connecting pipes for water supply and hot water supply, and in particular, in a mechanical connection type pipe joint, a structure for preventing loosening between a cap nut and a joint body, and a cap nut The present invention relates to a structure having a function of confirming completion of tightening.

  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, Patent Document 1 discloses a pipe joint 10 shown in FIG. The pipe joint 10 includes a joint body 20 and a cap nut 30 having a tapered portion sandwiching a flare formed at the end of the pipe P, and connects the pipe P by tightening the joint body 20 and the cap nut 30. It is. Further, the pipe joint 10 includes a double ring structure indicator 40 (an inner ring 401, an outer ring 402) provided on the outer peripheral portion of the joint body 20 in order to confirm completion of tightening of the cap nut 30. ing. According to Patent Document 1, according to the pipe joint 10, the joint body 20 and the cap nut 30 are tightened until the inner ring 401 is completely covered with the outer ring 402 and the inner ring 401 cannot be seen. It is described that the completion of tightening can be visually confirmed.

JP-A-9-242949

  However, the pipe joint described in Patent Document 1 has the following problems to be solved. When the pipe P is connected by the pipe joint 10, due to variations in the thickness of the pipe P, the position where the cap nut 30 has been tightened is not a pinpoint position but has a certain width. The position of the range. However, the inner ring 401 is completely covered by the outer ring 402 and the position where the inner ring 401 cannot be seen is almost pinpointed by the axial dimension of the members constituting the pipe joint 10. Therefore, it may not be possible to reliably confirm whether the tightening of the cap nut is completed with the indicator 40.

  This invention is made | formed in view of this problem, and it aims at providing the pipe joint which can confirm reliably that the mechanical connection of a pipe | tube is completed.

In order to achieve the above object, the pipe joint of the present invention comprises:
A joint body having a receiving portion for receiving a diameter-enlarged portion formed at an end portion of the pipe and having a threaded portion on the outer peripheral portion, and a female threaded portion screwed into the male threaded portion at one end and the other end An intermediate member having a cap nut formed with a wall portion, and a pressing portion that is attached to the inside of the cap nut and presses the tube toward the receiving port by tightening the cap nut to the joint body; An elastic member that is mounted between the wall portion and the pressing portion; and a seal member that is mounted on the joint body and seals between the pipe and the joint body ,
A pipe joint that transmits the tightening force of the cap nut to the intermediate member via the elastic member and connects the pipe by pressing the pipe against the receiving port of the joint body,
The intermediate member has an indicator portion that extends from the pressing portion toward the other end side of the cap nut and protrudes from the other end of the cap nut when the tightening of the cap nut is completed,
The elastic member is
The elastic member is slightly deformed until the expanded diameter portion of the tube comes into contact with the receiving port and is sandwiched between the pressing portion and the receiving port. It is provided so that it may become a spring constant compressed.
According to this pipe joint, the cap nut is fastened to the joint body while the elastic member is slightly elastically deformed until the expanded diameter portion of the pipe is connected to the receiving port. When the cap nut is further tightened after the expanded diameter portion of the tube is connected to the receiving port, the elastic member is greatly elastically compressed and deformed. At the same time, the indicator part protrudes from the other end of the cap nut. The installer can confirm that the pipe connection work has been completed by confirming the indicator portion from the outside of the joint body.

In the pipe joint of the present invention, the indicator portion is
A cylindrical portion having a smaller diameter than the inner diameter of the wall portion can be formed. Further, the indicator part may be n or more arc-shaped parts. (Where n is a natural number of 1 or more)

  Thus, according to the pipe joint of the present invention, the builder can confirm that the connection of the pipe is reliably completed by confirming the indicator part protruding from the other end of the cap nut.

It is a half sectional view of the pipe joint which is an embodiment of the invention. It is a figure which shows the coupling main body in embodiment of this invention. It is a half sectional view showing a cap nut in an embodiment of the invention. It is a half sectional view showing an intermediate member in an embodiment of the invention. It is the top view and side view which show the elastic member in embodiment of this invention. It is sectional drawing which shows the state which mounted | wore the intermediate | middle member and the elastic member in the cap nut in embodiment of this invention. It is sectional drawing which shows the use condition of the pipe joint of embodiment of this invention. It is sectional drawing which shows a prior art.

An embodiment of the present invention will be described with reference to FIGS.
(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, an intermediate member 5, and an elastic member 6. And 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 expands from the packing groove 221 toward the back side, and is formed at the end of the pipe P when the pipe P is connected. Receive the expanded part. In the present embodiment, the enlarged diameter portion at the end of the pipe P is a flare portion described later. 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.

  FIG. 3 is a cross-sectional view showing the cap nut 3. As shown in FIG. 3, the outer peripheral portion 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. Yes. Further, the inner peripheral portion of the cap nut 3 is formed with a female thread portion 33 at one end on the joint body side and a wall portion 31 at the other end. A step portion 32 is formed on the joint body side of the wall portion 31 so as to have an inner diameter larger than the inner diameter of the wall portion 31 so that an intermediate member described later is attached.

FIG. 4 is a cross-sectional view showing the intermediate member 5. As shown in FIG. 4, the intermediate member 5 is a hollow member having a cylindrical portion 51 and a pressing portion 52 having a larger diameter than the cylindrical portion. Between the cylindrical part 51 and the press part 52, it forms in the step shape, and the press surface 53 pressed by the elastic member 6 mentioned later is formed. Further, a taper portion 54 that expands toward the end portion is formed on the inner surface on the pressing portion 52 side. As the material of the joint body 2, the cap nut 3, and the intermediate member 5, for example, an austenitic stainless cast steel SCS13 is used.

FIG. 5 shows the elastic member 6, FIG. 5 (a) is a front view, and FIG. 5 (b) is a side view. As shown in FIG. 5, the elastic member 6 is formed in an annular shape, and its outer diameter is slightly smaller than the stepped portion 32 of the cap nut 3 and its inner diameter is slightly larger than the small-diameter cylindrical portion 51 of the intermediate member 5. . Further, as shown in FIG. 5 (b), it has a shape undulating in the circumferential direction, and when compressed in the direction of arrow A, a reaction force repelling in the opposite direction is generated. As the material of the elastic member 6 , a plate material having elasticity such as spring steel or stainless steel is used.

  FIG. 6 is a half sectional view showing a state in which the intermediate member 5 and the elastic member 6 are mounted on the cap nut 3. As shown in FIG. 6, the elastic member 6 and the intermediate member 5 are attached to the step portion 32 of the cap nut 3 from the back side. At this time, the elastic member 6 is contained in an annular space surrounded by the wall portion 31 and the step portion 32 of the cap nut 3 and the cylindrical portion 51 and the pressing surface 53 of the intermediate member 5. The intermediate member 5 is mounted so that the end on the cylindrical portion 51 side is on the same plane as the end face of the cap nut 3.

  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.

Next, with reference to FIG. 7, the connection procedure of the pipe P using the pipe joint 1 is demonstrated. FIG. 7A shows an initial state of tightening the cap nut, and FIG. 7B shows the cap nut until the flare portion of the pipe P is sandwiched between the tapered portion 222 of the joint body 2 and the tapered portion 54 of the intermediate member 5. FIG. 7C shows a state where the cap nut 3 is further tightened.
(1) The joint body 2 to which the seal member 4 is attached, the intermediate member 5 and the elastic member 6 are assembled, and the cap nut 3 attached to the outer peripheral portion of the pipe P whose end portion is flared. As shown in FIG. 7A, 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) Further, as shown in FIG. 7B, the cap nut 3 is tightened while the seal member 4 is crushed until the flare portion of the pipe P is sandwiched between the taper portion 54 of the intermediate member 5 and the taper portion 222 of the joint body 2. . At this time, the elastic member 6 has a reaction force (tension) larger than a thrust force required to press the tube P against the taper portion 222 against the repulsive force from the seal member 4, so that the elastic member 6 is hardly deformed in this state. Slightly deformed. Therefore, the end surface of the cylindrical portion 51 of the intermediate member 5 at this time is flush with the end surface of the wall portion 31 of the cap nut 3.
(3) Until the state shown in FIG. 7B, the force with which the elastic member 6 is compressed is about the repulsive force accompanying the compression of the seal member 4 , but as shown in FIG. When the tightening is advanced, the tapered portion 222 and the flare portion of the pipe P come into contact with each other, so that the propulsive force by the screw accompanying the tightening of the cap nut 3 acts as a force for compressing the elastic member 6. Since both the taper portion 222 and the pipe P are made of a metal material, the force at this time is extremely larger than the repulsive force accompanying compression of the seal member 4 . As a result, the elastic member 6 is compressed and elastically deformed between the wall portion 31 of the cap nut 3 and the intermediate member 5. The elastic member 6 is slightly deformed until the flare portion of the tube comes into contact with the receiving port and is sandwiched between the pressing portion and the receiving port, and is greatly elastically compressed when the cap nut is further tightened after the flare portion and the receiving port are in contact with each other. The spring constant is set as follows. Accordingly, the cylindrical portion 51 of the intermediate member 5 protrudes from the end portion of the cap nut 3. By confirming this state from the outside, it can be confirmed that the pipe P is securely connected. Thus, the cylindrical part 51 of the intermediate member 5 functions as an indicator part for confirming that the connection of the pipe P is completed. In the present embodiment, the indicator portion is the cylindrical portion 51, but the indicator portion may be one or more arc-shaped portions extending from the pressing portion toward the other end side of the cap nut. .

  Further, according to this pipe joint, the repulsive force of the compressed elastic member 6 also acts to strengthen the contact between the male thread part 23 of the joint body 2 and the female thread part 33 of the cap nut 3, so that vibration is caused. It is also effective as a loosening stop when an external force is applied in the direction in which the cap nut 3 is loosened.

  In addition, this invention is not restricted to the pipe joint of the form shown in FIG. 1, It can change in the range which does not deviate from the summary of invention. For example, if the elastic member 6 has a spring force that compresses and elastically deforms the seal member when the pipe is connected, it may be a disc spring or a coil spring in addition to the specially shaped spring shown in FIG. May be. Further, the pipe to be connected is not limited to one having a flare portion at the pipe end. For example, the present invention can be applied to a mechanical pipe joint that connects pipes in which the outer peripheral portion of the pipe end is inflated to form an annular protrusion.

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 3: Cap Nut 31: Wall Part, 32: Step Part, 33 : Female thread part 4: Seal member 5: Intermediate member 51: Cylindrical part, 52: Pressing part, 53: Pressing surface, 54: Tapered part 6: Elastic member P: Tube

Claims (1)

A joint body having a receiving port for receiving the enlarged diameter portion formed at the end of the pipe and having a threaded portion on the outer peripheral portion;
A cap nut having a female screw portion screwed into the male screw portion at one end and a wall portion formed at the other end;
An intermediate member having a pressing portion for pressing against the tube to the receptacle by being mounted inside the cap nut, tightening the cap nut on the fitting body,
An elastic member mounted between the wall portion and the pressing portion;
A seal member mounted on the joint body and sealing between the pipe and the joint body;
With
A pipe joint that transmits the tightening force of the cap nut to the intermediate member via the elastic member and connects the pipe by pressing the pipe against the receiving port of the joint body,
The intermediate member has an indicator portion that extends from the pressing portion toward the other end side of the cap nut and protrudes from the other end of the cap nut when the tightening of the cap nut is completed,
The elastic member is
The elastic member is slightly deformed until the seal member is crushed and the expanded diameter portion of the tube comes into contact with the receiving port and is sandwiched between the pressing portion and the receiving port. A pipe joint characterized by being provided so as to have a spring constant to be compressed.

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