JP6099800B1 - Pipe joint structure - Google Patents

Abstract

The present invention provides a pipe joint structure having a large pull-out resistance, excellent sealing properties, and capable of performing pipe connection work easily and quickly. A joint main body 10 and a pressure holding ring 3 attached to the joint main body 10 are provided. A plastic working protrusion 9 is protruded from the thin metal pipe 4, and the joint main body 10 and the pressure holding ring 3 are provided. The inner and outer gradient surfaces of the ridge 9 are held and held by the holding rings 1 and 2, and the pressing holding ring 3 is approached in the axial direction and rotated by a small angle in the radial direction with respect to the tip of the joint body 10. Further, they stop each other and further include an insertion member 32, and the insertion member 32 prevents the rotation of the pressing holding ring 3. [Selection] Figure 1

Description

  The present invention relates to a pipe joint structure.

  Conventionally, as a pipe joint, by screwing the male thread portion of the retainer into the tapered female thread portion of the joint body, the outer top portions of a plurality of small disks protruding from the inner peripheral surface of the retainer bite into the outer peripheral surface of the pipe. A pipe that is configured not to be pulled out in the axial direction is known (see Patent Document 1).

Japanese Patent No. 312385

  However, since the pipe joint described in Patent Document 1 causes the small disk to spiral into the pipe body gradually and deeply around the outer peripheral surface of the pipe, a very large tightening force is required to screw the retainer into the joint body. The work efficiency is poor. In particular, connection work at a high place was difficult. In addition, since it is structured to prevent pulling out by several small discs that bite into the outer peripheral surface of the pipe, if a strong pulling force is applied to the pipe after connection is completed, it may come off while leaving a scratch in the longitudinal direction on the outer peripheral surface of the pipe. Or, there was a possibility that the small disk was damaged and the pipe was pulled out.

  Therefore, the present invention can be connected by tightening with a small force without requiring a large force, the connection work can be easily and quickly performed, and even if a strong pulling force is applied to the pipe, there is a possibility that it will come off. It aims at providing the pipe joint structure which can connect reliably and firmly.

  The pipe joint structure according to the present invention includes a joint main body and a pressure holding ring that is attached to the joint main body in an outer fitting manner; the thin metal pipe has plastic working ridges intermittently in the circumferential direction, or The outer periphery of the joint body and the inner periphery of the press-holding ring are fitted by the axial approach of the press-holding ring and rotated at a small angle in the radial direction. A locking means for locking each other; by the locking means, the outer peripheral area of the inner peripheral portion of the press-holding ring and the distal end area of the inner peripheral portion of the joint body with respect to the ridges of the metal tube In order to be held from the outside / inside of the axial direction, and to maintain the holding state by the locking means, it is inserted into the pressing holding ring from the axial direction in the direction opposite to the small angle rotation. An insertion member that prevents rotation of the .

In addition, the outer peripheral surface of the inner peripheral portion of the pressing holding ring corresponds to the outer slope surface of the convex strip of the metal tube via a closed annular holding ring having a tapered inner peripheral surface.
Moreover, the taper-shaped inner peripheral surface formed in the outer peripheral area of the inner peripheral part of the press-holding ring directly corresponds to the outer inclined surface of the ridge of the metal tube.
Moreover, the inner peripheral part front-end | tip area | region of the said joint main body respond | corresponds via the closed annular | circular shaped holding ring which has a taper-shaped inner peripheral surface with respect to the inner-gradient surface of the protruding item | line of the said metal pipe.
Moreover, it is the structure which the inner peripheral part front end area | region of the said joint main body respond | corresponds directly with respect to the inner-gradient surface of the protruding item | line of the said metal pipe.
Moreover, it corresponds so that the inner peripheral corner | angular part of the inner peripheral part front-end | tip area of the said joint main body may contact directly the skirt of the inner-gradient surface of the protruding item | line of the said metal pipe.

  Further, in the joint body, a plurality of arc-shaped outer ridges and smooth arc-shaped bottom surfaces are alternately arranged on the outer periphery of the tip, and each arc-shaped outer ridge is between the locking groove portions. A pair of outer ridges forming a pair; further, in the press-holding ring, on the inner peripheral portion thereof, the locking groove between the pair of outer ridges alone is rotated in a small angle in the radial direction. A plurality of arc-shaped inner ridges that can be engaged with each other, and an arc-shaped slit is provided between the adjacent inner ridges in the axial direction; the locking means includes a locking groove and The arc-shaped inner ridge portion is provided.

Further, the insertion member integrally includes a C-shaped or closed annular basic ring portion and a plurality of protruding pieces projecting in an axial direction from the basic ring portion; the protruding piece of the insertion member The locking means is inserted into the arc-shaped slit portion of the press-holding ring and the smooth-arc-shaped bottom surface portion of the joint body in the locked state of the press-holding ring in the reverse direction of the press-holding ring. The rotation is prevented and the holding state by the locking means is maintained.
Further, at least one of the plurality of protruding pieces is provided with a retaining claw or a locking claw piece portion.

  According to the pipe joint structure of the present invention, with respect to the plastic working protrusions formed on the thin metal pipe, indirectly or directly, the inner peripheral part outer end region of the press holding ring and the joint main body If the insertion member is manually inserted in the axial direction with respect to the pressure holding ring by the tip region, the pipe connection work is easily completed. That is, the connection work is easy and convenient for connecting various places and pipes. In particular, even when the worker connects the pipe at a high place such as the back of the ceiling, there is little risk of dropping the part from the high place, and it does not take time, so the work can be performed quickly and smoothly. . With a simple structure, it is possible to surely obtain a retaining state with an extremely large pull-out prevention force, and prevent the thin metal tube from being unexpectedly pulled out after construction.

It is a section side view of the connection completion state which shows one embodiment of the present invention. It is a perspective view which shows a decomposition | disassembly state. It is a perspective view explaining connection work of the present invention one by one. It is sectional drawing which showed the state before pushing in an insertion member, (A) is whole sectional drawing, (B) is an important section expanded sectional view, (C) is an expanded sectional view of another important section. . It is a principal part expanded sectional view which shows another cross section, (A) is a principal part expanded sectional view before pushing in an insertion member, (B) is a principal part expanded sectional view of a connection completion state. It is the principal part expanded sectional view which showed other embodiment of this invention, (A) is a principal part expanded sectional view before pushing in an insertion member, (B) is the principal part expanded sectional view of a connection completion state It is. It is the side view explaining the working tool which forms a protruding item | line in a thin metal pipe by plastic working, and its working method. It is a side view explaining the working tool and working method which form a convex strip intermittently in the circumferential direction on a thin metal pipe. It is a side view explaining the working tool and working method which form a convex strip intermittently in the circumferential direction on a thin metal pipe. It is a front view of the principal part corresponding to FIG. 8 and FIG. It is a front view of the metal pipe in which the plastic working convex line was intermittently formed in the circumferential direction. It is sectional drawing which shows another embodiment of this invention, (A) is sectional drawing of the principal part, (B) is an expanded sectional view of the Z section of (A). It is principal part sectional drawing which shows the state just before a connection. It is a figure which shows the principal part of a coupling main body, Comprising: (A) is a principal part perspective view, (B) is a front view, (C) is (aOa) sectional drawing of (B). It is a figure which shows a press holding ring, Comprising: (A) is a front view, (B) is a rear view, (C) is (b-Ob) sectional drawing of (A). It is a figure which shows an insertion member, Comprising: (A) is a front view, (B) is a b arrow view of (A), (C) is a c arrow view of (A). It is sectional drawing explaining the method of carrying out plastic working of a protruding item | line on a metal pipe. It is a schematic explanatory drawing explaining the operation | work procedure which connects a metal pipe and a coupling. It is sectional drawing explaining the specific shape of a plastic working convex line.

Hereinafter, the present invention will be described in detail based on the illustrated embodiment.
In the embodiment shown in FIGS. 1 to 5, reference numeral 4 denotes a thin metal tube, and a plastic working protrusion 9 is projected (formed) at a predetermined dimension position from the tip 4 a.
The pipe joint structure according to the present invention includes a joint main body 10 into which the thin metal pipe 4 is inserted, and a press holding ring 3 attached to the joint main body 10 in an outer fitting shape.
The thin metal pipe 4 (hereinafter sometimes simply referred to as the pipe 4) is a stainless steel pipe defined in, for example, JIS G3448, and is mainly used for piping such as water supply / hot water supply or drainage.
Table 1 shows the relationship between the outer diameter D of the thin metal pipe 4 and the wall thickness t. The thin metal tube 4 preferably has an outer diameter D set to 10 mm to 65 mm and a wall thickness t set to 1.0 mm to 1.6 mm.

The plastic working ridges 9 of the thin metal tube 4 are intermittently projected in the circumferential direction (see FIG. 11), or are projected over the entire circumference (360 °). This ridge 9 has a triangular mountain shape as shown in FIG. 19 (A), a triangular mountain shape with a rounded top as shown in FIG. 19 (B), or a round hill as shown in FIG. 19 (C). There are types.
A locking means 100 that can be locked to each other is provided on the outer peripheral portion 10A of the joint body 10 and the inner peripheral portion 3A of the press-holding ring 3. That is, as shown in FIG. 3, the fitting main body is obtained by fitting (mutually) the pressing holding ring 3 by approaching in the axial direction indicated by an arrow N and by rotating at a small angle in the radial direction indicated by the arrow M. The outer peripheral portion 10A of the tip 10 and the inner peripheral portion 3A of the press holding ring 3 are locked to each other by the locking means 100, and the press holding ring 3 is not separated from the joint body 10 in the axial direction. Keep locked.

  Furthermore, 32 is an insertion member. By the locking means 100, the inner peripheral portion outer end region 3B of the press holding ring 3 and the inner peripheral portion distal end region 10B of the joint main body 10 are indirectly (in FIGS. 1 to 5) the ridges of the pipe 4. 9, in order to maintain the holding state by the locking means 100 with respect to the pressing holding ring 3 (see FIG. 3D). The insertion member 32 is inserted from the axial direction (indicated by an arrow (P)) to prevent rotation in the reverse direction of the small angle rotation (M). In other words, the insertion member 32 is a member for preventing the press holding ring 3 from loosening.

By the way, the point that the outer peripheral area 3B of the inner peripheral portion of the pressure retaining ring 3 presses (corresponds) to the convex strip 9 of the metal tube 4 from the outside in the axial direction will be described as a tapered shape. The outer peripheral surface 3B of the ridge 9 corresponds (presses) to the outer slope surface 9A of the ridge 9 via the closed annular holding ring 1 (such as soft metal or hard resin) having the inner peripheral surface 6. ing.
Furthermore, when the point which the inner peripheral part front end area | region 10B of the coupling main body 10 presses (corresponds) from the inner side of an axial direction with respect to the protruding item | line 9 is demonstrated, it has the taper-shaped inner peripheral surface 7. The inner peripheral surface tip region 10B corresponds (presses) to the inner slope surface 9B of the ridge 9 via the closed annular holding ring 2 (such as hard resin).

In the embodiment shown in FIGS. 1 to 5, the tapered inner peripheral surfaces 6 of the two holding rings 1 and 2 are connected to the outer inclined surface 9A and the inner inclined surface 9B of the ridge 9 in a connected state. , 7 correspondingly hold.
Further, as shown in FIG. 5, a large diameter hole portion 86 is formed with a stepped portion 85 in the inner peripheral tip end region 10B of the joint body 10, and the sealing material protection ring 14, (O The sealing material 12 (such as a ring) and the holding ring 2 are fitted. It is desirable that the three parts are fitted in the large-diameter hole portion 86 of the joint body 10 in advance in an unconnected state. The reason is that before the connection work, the holding rings 1 and 2 which are small parts are not separated (does not fall off), and workability can be improved.
The material of the holding rings 1 and 2 is preferably a soft metal such as copper or a hard resin having heat resistance such as PPS, PPSU, or PSU.

Next, the ridge 9 in the present invention is formed on the metal tube 4 in a closed ring over the entire 360 ° circumference, and when viewed from the direction of the axis L as illustrated in FIG. ), And may protrude intermittently in the circumferential direction.
Although FIG. 11 shows a case where the ridges 9 are formed in four divided shapes, it is free to reduce this to two or three, or conversely increase to five to eight. (The manufacturing method and the work tool will be described later with reference to FIGS. 8 to 10.)

  By the way, the joint body 10 is formed with a large-diameter hole portion 86 having a tip opening shape with a stepped portion 85, and the flat washer-shaped sealing material protection ring 14 is formed with a large-diameter hole portion so as to contact the stepped portion 85. It is installed on the back side of 86. Furthermore, as described in FIG. 5, the sealing material 12 such as an O-ring and a part of the holding ring 2 are sequentially attached. However, the sealing material protection ring 14 has a sealed fluid (hot water, water, etc.). ) Is a ring that effectively prevents ozone (active oxygen), chlorine, hydrogen, etc. mixed into the seal material 12 from causing corrosion and deterioration after long-term use. In close contact with the outer peripheral surface of the metal tube 4 (inserted) and the inner peripheral surface of the large-diameter hole 86, the sealed fluid is prevented from coming into direct contact with the sealing material 12. .

The holding ring 2 is fitted in a large-diameter hole 86 of the joint body 10 in a press-fit state in advance (under an unconnected state), and the rear side end surface of the holding ring 2, a stepped portion 85, and a large diameter With the inner peripheral surface of the hole 86, the concave circumferential groove 18 that holds the protective ring 14 and the sealing material 12 described above is formed.
In the joint body 10, a medium-diameter hole 38 slightly larger than the outer diameter D of the metal tube 4 (see FIG. 4) is formed at the back of the large-diameter hole 86. That is, at the stepped portion 85, the large-diameter hole portion 86 and the medium-diameter hole portion 38 are defined. Further, on the back side of the medium-diameter hole portion 38, a circumferential contact step portion 15 is formed, which is positioned by contact with the tip 4a of the inserted metal tube 4, and a small-diameter hole portion 39 is formed in the back thereof. Has been.
The metal tube 4 is connected to the pipe joint so that it does not rattle in the axial direction by the circumferential contact step 15 and the holding ring 1 that has received the pressing force F accompanying the attachment of the pressing holding ring 3 ( Connected).

Next, FIG. 6 shows another embodiment. This pipe joint structure also includes a joint body 10 and a pressure holding ring 3, and the pressure holding ring 3 has a tapered inner peripheral surface 3 </ b> C that is reduced in diameter toward the distal end opening side at the outer peripheral end region 3 </ b> B. Nut shape.
When the press holding ring 3 is attached to the joint body 10 as shown in FIG. 6, the tapered inner peripheral surface 3 </ b> C of the press holding ring 3 is directly pressed against the outer slope surface 9 </ b> A of the ridge 9. In addition, the inner peripheral surface 7 of the closed annular holding ring 2 having the tapered inner peripheral surface 7 is in pressure contact with the inner slope surface 9B of the convex strip 9, and the convex strip 9 of the metal tube 4 is axially moved. It is a configuration that holds it firmly in the outer direction and the axial inner direction.
That is, the tapered inner peripheral surface 3 </ b> C formed in the outer peripheral area 3 </ b> B of the inner peripheral portion of the press retaining ring 3 directly corresponds to the outer inclined surface 9 </ b> A of the convex strip 9 of the metal tube 4.

  Next, another embodiment shown in FIGS. 12 to 17 will be described. The ridges 9 formed on the metal tube 4 by plastic working are of a round hill shape, and the top is also formed in a large round shape (see FIG. 19C). The inner peripheral tip region 10B of the joint body 10 directly corresponds to the inner gradient surface 9B of the ridge 9 of the metal tube 4. In particular, in the illustrated example, the inner peripheral corner portion 41 of the inner peripheral tip end region 10B of the joint body 10 is formed with respect to the skirt 40 of the inner slope surface 9B of the lower round mountain type (round hill type) ridge 9 of the metal pipe 4. , Corresponding to direct contact. As described above, the corner 41 of the joint body 10 is in direct contact with the inner slope surface skirt 40 of the ridge 9 by metal touch without interposing the holding ring 2 shown in FIGS.

  A seal groove 42 is recessed in the inner peripheral tip region 10B of the joint body 10, and the seal material 12 and a protective ring (flat washer) 14 are housed in the seal groove 42. Due to the presence of the outer side wall 42A of the seal groove 42, the inner peripheral corner portion 41 can directly correspond to (contact with) the base 40. The inner peripheral corner portion 41 may be sharp as shown in FIGS. 12 and 13, but in addition to this, a small chamfer 43 is taken as shown in FIG. It is also preferable to keep the surface pressure low. In addition, it can be said that the seal groove 42 is provided in the medium diameter hole portion 38, and a circumferential contact step portion 15 is provided in the inner portion thereof, and the distal end 4 a of the inserted metal tube 4 is provided. It is possible to abut, and it is blocked by striking without being inserted deeper (behind).

Next, the locking means 100 and the configuration related thereto will be described.
12, 13, 14, 2 to 5, and 6, the joint body 10 includes a plurality of arc-shaped outer ridges 19 and a smooth arc-shaped bottom surface 20 on the outer periphery 10 </ b> A of the tip. Are alternately arranged. Further, each arc-shaped outer ridge portion 19 includes a pair of outer ridge single pieces 21 and 22, and a locking groove portion 23 is formed between the pair of outer ridge single pieces 21 and 22.
On the other hand, a plurality of arc-shaped inner ridge portions 30 are provided on the inner peripheral portion 3 </ b> A of the press holding ring 3. The inner protrusion 30 can be engaged with the locking groove 23 on the joint body 10 side by “small angle” rotation in the radial direction (see arrow M). This “small angle” is about 45 ° when the four inner protrusions 30 are provided at a pitch of 90 °.

The inner protrusion 30 and the locking groove 23 may be two, three, six, etc., and the “small angle” in that case is about 90 °. , 60 °, 30 °.
Further, in the press holding ring 3, an arcuate slit portion 25 is provided between the adjacent inner protrusion portions 30, 30 in the axial direction.
It can be said that the locking means 100 includes at least the locking groove 23 and the arc-shaped inner ridge 30.
More specifically, the locking means 100 is configured by a ridge portion 19, a smooth arc-shaped bottom surface portion 20, a locking groove portion 23, and an arc-shaped inner ridge portion 30.

Next, the insertion member 32 will be described. In some cases, the insertion member 32 has a C-shaped basic ring portion 33 as shown in FIG. 16, and in other cases, it has a closed annular basic ring portion 33 as shown in FIGS. . A plurality of projecting pieces 81, 82, 83, 84 project from the basic ring portion 33 in the axial direction.
In FIG. 16, the projecting pieces 81 and 82 and the basic ring portion 33 are integrally formed of synthetic resin, and the two projecting pieces 81 and 81 provided at positions opposite to each other by 180 ° are arc-shaped in a simple cross section. The projecting piece 82 provided at a position 180 ° opposite to the notch 87 of the C-shaped basic ring portion 33 is divided into three parts, and consists of a central piece 82A and left and right side pieces 82B and 82B. . A locking claw 88 is provided at the tip of the side piece 82B. Moreover, as shown in FIG. 16, the small locking claws 88 are protruding in the circumferential direction.

The insertion member 32 shown in FIGS. 2 and 3 will be described. The two projecting pieces 83 and 83 and the two projecting pieces 84 and 84 from the closed annular basic ring portion 33 are pitched by 90 ° in the circumferential direction. The cross section is arc-shaped. The pair of projecting pieces 84, 84 has a U-shaped separation line, and a locking claw piece portion 88B is integrally formed.
The projecting pieces 81, 82, 83, 84 of the insertion member 32 are connected to the arc-shaped slit portion 25 of the press-holding ring 3 and the smooth arc-shaped bottom surface portion of the joint body 10 under the locked state of the locking means 100 described above. For 20, plugged. That is, as shown in FIG. 3C, when the pressure holding ring 3 is rotated by a small angle in the direction of the arrow M, the locking means 100 is locked, and at the same time, the arc-shaped slit 25 and the smooth arc-shaped bottom 20 Are opposed to each other at the same position in the circumferential direction, and an arcuate slit (gap) is formed in a penetrating shape when viewed from the axial direction. With respect to the penetrating arcuate slit (gap), FIG. As shown in FIGS. 5 (B), 6 (B), and 12, protrusions 81, 82; 83, 84 are inserted.

In addition, the protrusions 81, 82, 83, 84 are completely inserted into the penetrating arc-shaped slit (gap), and at the same time, the locking claw piece 88B is shown in FIGS. 5 (B) and 6 (B). As shown in the figure, the retaining ring 3 is engaged with a part of the retaining ring 3 or the engaging claw 88 (see FIG. 16) is engaged with the small concave recesses 89, 89 of the outer protrusion single piece 21 of the joint body 10, The insertion member 32 is prevented from coming off.
In this way, the insertion of the insertion member 32 in the direction of the arrow P prevents the pressing and holding ring 3 from rotating in the opposite direction (from the arrow M), and the holding means 100 holds the ridge 9 in the holding state. To maintain.

As a work tool for forming the ridges 9 (over the entire circumference of 360 °) on the thin metal tube 4, a ridge forming tool 35 illustrated in FIG. 7 can be used. If the roller 34 with small ridges is inserted into the metal tube 4 so as to face the roller 98 with concave grooves, and the whole is rotated, the ridges 9 can be easily formed.
The work tool (projection forming tool 35) shown in FIG. 7 is suitable for forming the projection 9 over 360 ° (entire circumference), but instead, the intermittent operation shown in FIGS. Using the target ridge forming jig 55, the ridges can be intermittently projected as shown in FIG. That is, the ridge 9 is composed of four circumferential protrusions 75, 75, 75, 75. The jig 55 is created by the inventor of the present invention, and the structure and method of use (action) will be briefly described below.

  56 is a jig main body (work tool main body), and a pair of pipe gripping arms 58 and 58 are pivotally mounted via a shaft portion 57, and have semicircular arc-shaped concave portions 58A and 58A. In the closed state, a 360 ° pipe holding hole 59 is formed. Note that the above-described 360 ° pipe holding hole 59 can be firmly formed and held with a fastener such as a bolt or nut (not shown). In addition, a concave circumferential groove 60 (as a female mold) for forming the ridge 9 is formed in the holding hole 59. The tip portion of the thin metal pipe 4 to be processed is inserted into and held by the pipe holding hole 59 having the concave circumferential groove 60.

61 is a guide cylinder constituting a part of the jig body 56, and has a small cylindrical portion 61A having an outer diameter slightly smaller than the inner diameter of the metal tube 4 and an outer diameter larger than this. And a large cylindrical portion 61B. The stepped surface portion 61C of the small cylindrical portion 61A and the large cylindrical portion 61B serves as a “contact surface” for positioning the tip end surface of the metal pipe 4 to be processed.
The large cylindrical portion 61B is formed by coaxially connecting a circular hole portion 62 that opens to the left in FIGS. 8 and 9 and a small-diameter hole portion 64 formed in the bottom wall portion 63 on the right side in FIGS. It has a shape. Then, across the bottom wall 63 and the small cylindrical portion 61A, a tapered hole 65 that gradually expands in diameter on the side where the pipe gripping arm 58 exists—referred to as the tip end side—is formed into the circular hole 62 and The small-diameter hole portion 64 is coaxially formed.

A movable shaft 66 is inserted along the axis of the guide cylinder 61 so as to be reciprocally movable. The moving shaft body 66 includes a reverse-tapered cone shaft portion 67 and a bolt shaft portion 68 that gradually increase in diameter in the distal direction, a widening operation shaft 69 having a bolt shaft portion 68, a reciprocating motion in the circular hole portion 62, and a screw. And a drive shaft portion 71 having a hole 70. The bolt shaft portion 68 is screwed (connected) into the screw hole 70 of the drive shaft portion 71, and the bolt shaft portion 68 and the drive shaft portion 71 are reciprocated integrally along the axial direction. The drive shaft 71 is linked to a hydraulic cylinder and an electric drive mechanism (not shown in the left direction in FIGS. 8 and 9).
As shown in FIGS. 8, 9, and 10, four fan-shaped arc-shaped convex portion formation bodies 72, 72, 72, 72 are attached to the cone shaft portion 67 so as to be externally fitted. In the arc-shaped convex portion forming body 72, the tapered inner surface 72A is slidably in contact with the cone shaft portion 67, and the convex strip 9 is intermittently formed on the outer surface of the metal tube 4 as shown in FIG. It has a protruding ridge 72B.

  That is, with respect to the concave circumferential groove 60 as the female mold, the protrusion 72B of the arc-shaped convex forming body 72 as the male mold from the inner surface side of the metal tube 4 is in the state shown in FIGS. From FIG. 9 and FIG. 10 (B), if the expansion operation shaft 69 is moved in the direction of arrow Z by the drive mechanism (not shown), the drive mechanism moves in the direction of arrow Y (radial outward direction) in FIG. In the tube 4 (as shown in FIG. 11), intermittent projections 9--four projections 75, 75, 75, 75 --- are plastically processed. When the ridge 9 has a triangular mountain shape, it is desirable to form a sufficiently sharp (vertical) triangular mountain-shaped concave portion on the inner surface side of the metal tube 4, so that an arc shape is formed. The protrusion 72B of the convex forming body 72 is also preferably a triangular mountain shape having a sharp apex. In addition, when the protruding item | line 9 is a top part round shape or a round hill shape like FIG.19 (B) and (C), the protrusion part 72B shall be round (round shape).

By the way, in the said description about FIGS. 8-11, although the case where the plastic working protruding item | line 9 consists of four convex parts 75,75,75,75, this was reduced to two or three, Or it is also possible to increase to 5-9 pieces.
Moreover, the advantage at the time of forming the protruding item | line 9 which consists of several convex part 75,75 ... intermittently in this way is demonstrated. As illustrated in FIG. 11, when viewed from the axial direction, each convex portion 75 has a three-dimensional shape (shell structure) with a reduced size of the mountain at the circumferential end portions 75A and 75A of the convex portion 75. These end portions 75A and 75A are not easily deformed when a force is applied from the outside, and have high rigidity. For this reason, the connections shown in FIGS. 1, 5B, 6B, and 12 are used. When the pulling force is applied to the metal tube 4 from the completed state, it serves to prevent the protrusion 9 from being deformed, and the pulling-out force can be increased.

Next, referring to FIG. 17, another method and jig for forming the ridges 9 on the metal tube 4 by plastic working will be described. The upper half portion from the axis L indicates the state immediately before the plastic processing, and the lower half portion from the axis L indicates the state of the completion of the plastic processing.
Outside of the left side of FIG. 17, a linear reciprocating unit such as a rod of a linear reciprocating cylinder (not shown) such as a manual pump or an electric pump or a rod of an electric linear reciprocating actuator is provided. A rod-like jig 45 is connected to the moving part.

A tip 47 of the metal pipe 4 to be processed is provided with a body 47 provided with a hole 46 through which a small dimension can be inserted.
The jig 45 has a stepped surface portion 48 and a short column head 49 having an outer diameter that fits tightly inside the metal tube 4 on the tip side. The tip 4a of the metal tube 4 comes into contact with the stepped portion 47A on the back side of the hole of the body 47, and the work is performed. 50 is a spacer cylinder, 51 is an elastically deformable elastic ring such as rubber, and the spacer cylinder 50 and the elastic ring 51 are externally fitted to the small-diameter shaft 52 of the jig 45 and stepped. The elastic ring 51 is elastically deformable from the original short cylindrical shape to a shape (such as being lowered below the axis L) by receiving an axial force between the portion 47A and the stepped surface portion 48. Then, the externally fitted metal tube 4 is locally bulged and deformed.

By the way, in FIG. 17, as a so-called female mold 53 required for the above-described bulging deformation (plastic processing), one part itself of a pipe joint structure is used. That is, the press holding ring 3 illustrated in FIG. 15 is used.
Specifically, on the outer surface 54 of the front end portion of the body 47, a single outer ridge 22 and a locking groove 23 as shown in FIGS. 14A and 13 and a smooth arc-shaped bottom surface portion 20 are provided. In this manner, as the female die 53, the press holding ring 3 used directly on the predetermined metal tube 4 is attached to the outer surface 54 of the front end portion of the body 47 in a locking manner.

As shown in FIG. 17, it is difficult to form the ridge 9 in the shape as shown in FIG. 19C or FIG. 19B only with the female mold 53, but at the forefront of the body 47, FIG. The small protrusion 76 slightly inserted into the straight circumferential surface 3D (continuous to the tapered inner circumferential surface 3C) and the concave chamfer 46A at the opening end corner of the hole 46 are shown in FIG. In addition to (in cooperation with) the inner peripheral surface 3C of the die 53 (holding ring 3), as shown in FIG. 19 (C), the top portion is a triangular mountain shape or as shown in FIG. 19 (B). In this structure, a female mold recess corresponding to the round hill type is formed.
The jig 45 moves in the direction of arrow K from the upper half to the lower half in the direction of the arrow K by an actuator or the like outside the left figure in FIG. 17, so that the outer peripheral surface of the elastic ring 51 is elastically expanded. As shown in the arrow P ₅₁ , the protrusion 9 can be locally formed on the metal tube 4 (over the entire 360 ° circumference).

The shape of the tip outer peripheral surface 10A of the joint body 10 shown in FIG. 14 is formed as it is on the tip outer surface 54 of the body 47, so that the holding ring 3 is rotated by a small angle in the direction opposite to the arrow M described above. Thus, the holding ring 3 can be separated together with the metal tube 4. At this time, the jig 45 and the like are also separated from the metal tube 4 to be in the state shown in FIG. 13, and in the same manner as described in FIG. 3, (A) → (B) → (C) → (D) in FIG. In order--that is, in the order of arrows N->M-> P--the connection work may be performed.
According to the ridge forming apparatus and method shown in FIG. 17, the ridge 9 having the shape of FIG. 19B or FIG. 19C can be formed easily and quickly with high accuracy.

  In the present invention, as shown in FIGS. 3 and 18, after the metal tube 4 is inserted into the joint body 10, (i) the pressing holding ring 3 is pushed in the arrow N direction (axial direction), ii) Rotate the pressure retaining ring 3 in the direction of arrow M by a small angle to switch to the holding state by the locking means 100, and then (iii) insert the insertion member 32 in the direction of arrow P to bring the connection completed state Work is done easily and quickly.

  According to the present invention, due to the presence of the ridges 9 formed on the metal tube 4, the inner peripheral outer end region 3B of the press retaining ring 3 and the inner peripheral distal end region 10B of the joint body 10 are By holding the ridges 9 in the axially outward and inward holding state, a strong pull-out force is exhibited. In this holding state, the axial direction (direction along the axis L) In the embodiment shown in FIGS. 1 to 5 and 6, the joint main body 10 and the metal tube 4 are relatively hardly moved at all. Ideally, it is preferable because it exhibits a high pull-out resistance and high sealing performance.

  However, in another embodiment shown in FIGS. 12 to 17, the ridge 9 has a rounded top (see FIG. 19 (B)), or the whole is a round hill (see FIG. 19 (C)). When the inner peripheral portion distal end region 10B of the joint body 10 is in direct contact with the joint body 10, it can be configured to be relatively finely moved in the axial direction, and as shown in FIG. Since the material 12 is fitted into an independent seal groove 42 and is not adversely affected by the above-mentioned fine movement, the sealing performance can be secured, and the taper inner peripheral surface 3C of the retaining ring 3 is provided with a ridge 9 against the pulling force. The outer slope surface 9A is pressed with a relatively large contact area, so that the metal tube 4 is sufficiently damaged without causing any damage.

Thus, in the present invention, the joint main body 10 and the metal tube 4 may slightly move in the axial direction under the connection completion state.
The tip 4a of the metal tube 4 corresponds to the contact step 15 inside the hole of the joint body 10, and exhibits the function of preventing the movement of the metal tube 4 in the axial inward direction. It is also desirable to reduce (or prevent).
Further, the locking claw piece 88B illustrated in FIG. 3D, FIG. 5B, and FIG. 6B or the locking claw 88 illustrated in FIG. It is desirable to color so as to obtain a color with high brightness. Examples of the coloring method include a method in which the insertion member 32 is formed by plastic two-color molding, or a method in which the outer surfaces of the locking claw pieces 88B and the locking claw 88 are colored by painting or the like. In this way, there is an advantage that the pipe connection completion state can be reliably confirmed visually.

  As described in detail above, the present invention includes a joint body 10 and a press-holding ring 3 attached to the joint body 10 so as to be fitted onto the joint body 10. Intermittently or projecting over the entire circumference, and fitted to the outer peripheral portion 10A of the joint body 10 and the inner peripheral portion 3A of the press-holding ring 3 by approaching the press-holding ring 3 in the axial direction. And a locking means 100 which locks each other by a small angle rotation in the combined and radial directions, and by the locking means 100, the inner peripheral portion outer end region 3B of the press holding ring 3 and the joint body 10 In order for the inner peripheral tip region 10B of the metal tube 4 to be held from the outside / inside of the axial direction with respect to the ridges 9 of the metal tube 4, and to maintain the holding state by the locking means 100, The small angle is inserted into the pressing holding ring 3 from the axial direction. Since the insertion member 32 that prevents the rotation in the reverse direction of rotation is provided, the pressure holding ring 3 does not need to be rotated many times like a conventional cap nut, for example, 15 ° to 90 °. It can be rotated by a small angle, and can be held, and the connection work can be performed easily and quickly. Further, after that, if the insertion member 32 is inserted into the pressing holding ring 3 from the axial direction, the pressing holding ring 3 does not loosen, but immediately maintains the connection completion state, and the entire operation is easier and quicker. Can be done. In addition, if the insertion member 32 cannot be inserted, the operator can easily know that the small angle rotation of the press holding ring 3 (in the previous step) is insufficient. Improper work can be immediately notified to the operator. Further, whether or not the insertion member 32 is sufficiently deeply inserted in the axial direction can be easily confirmed visually by the operator. As described above, the pipe connection work can be performed easily, surely and quickly, and in particular, the operator can easily and quickly perform the pipe connection in a narrow space or a ceiling. In addition, the structure can be made compact and simple, and the pipe pull-out prevention force is extremely large because of the structure for holding the convex strip 9 from both directions, thereby preventing an unexpected pull-out accident of the metal pipe after construction.

  Further, the outer peripheral area 3B of the inner peripheral portion of the press-holding ring 3 with respect to the outer inclined surface 9A of the ridge 9 of the metal tube 4 is interposed via a closed annular holding ring 1 having a tapered inner peripheral surface 6. Therefore, the holding ring 1 is brought into a pressure-contact state (holding state) stably and densely with respect to the outer slope surface 9A of the ridge 9 so that the pulling-out force can be stably and largely secured. Even when a large bending moment is applied to 4, the holding ring 1 has a buffering action to prevent the retaining ring 3 and the like from being damaged.

  Moreover, since the taper-shaped inner peripheral surface 3C formed in the outer peripheral area 3B of the inner peripheral portion of the press-holding ring 3 directly corresponds to the outer inclined surface 9A of the ridge 9 of the metal tube 4. The number of parts is reduced (as shown in FIGS. 6 and 12), and the contact surface pressure between the outer gradient surface 9A and the tapered inner peripheral surface 3C is small even in the metal touch, and the pulling force is applied to the metal tube 4. Even when a bending moment is applied, a sufficiently large pull-out force can be exhibited while maintaining a stable posture.

  In addition, the inner peripheral surface tip region 10B of the joint body 10 with respect to the inner inclined surface 9B of the ridge 9 of the metal tube 4 is interposed via a closed annular holding ring 2 having a tapered inner peripheral surface 7. Since it is a corresponding configuration, it can stably counter the pushing force of the metal tube 4 in the axial direction, and the metal tube 4 moves excessively to the back of the joint body 10, or the metal tube 4 and the joint body The 10 shaft centers can be prevented from being inclined or decentered, and the sealing performance can be kept good.

  Further, since the inner peripheral portion tip end region 10B of the joint body 10 directly corresponds to the inner inclined surface 9B of the ridge 9 of the metal tube 4 (as shown in FIGS. 12, 13, and 14). In addition, the axial dimension can be shortened and the number of parts can be reduced. Moreover, the metal tube 4 can sufficiently withstand the external force that is pushed into the joint body 10. Further, the joint body 10 is formed with a step portion 15 so that the distal end 4a of the metal tube 4 abuts against the above-mentioned external force to be pushed, and the fine movement of the ridge 9 in the axial direction can be prevented.

  Moreover, it corresponds so that the inner peripheral corner | angular part 41 of the inner peripheral part front-end | tip area | region 10B of the said joint main body 10 may contact directly with respect to the skirt 40 of the inner-gradient surface 9B of the protruding item | line 9 of the said metal pipe 4. With this configuration, the shape of the outer end face of the joint body 10 can be simplified (see FIGS. 13 and 14), and the size can be reduced. It is advantageous in terms of the strength of the ridges 9, and even if a slight movement of the metal tube 4 in the axial direction occurs, it can be said that the pull-out resistance is excellent and practical.

  Further, in the joint body 10, a plurality of arc-shaped outer ridges 19 and smooth arc-shaped bottom surface portions 20 are alternately arranged on the outer periphery 10A of the tip, and each arc-shaped outer ridge 19 is A pair of outer ridges 21, 22 forming a locking groove 23 between them is configured, and in the press holding ring 3, the pair of outer ridges 21, 22 are formed on the inner peripheral portion 3 A thereof. A plurality of arc-shaped inner ridges 30 that can be engaged with each other by the small-angle rotation in the radial direction are provided in the locking groove 23 between each other, and an arc-shaped slit is provided between the adjacent inner ridges 30, 30. Since the portion 25 is penetrated in the axial direction and the locking means 100 includes the locking groove portion 23 and the arc-shaped inner ridge portion 30, the retaining ring 3 extends from the joint body 10 in the axial direction. The movement to move to can be prevented powerfully and reliably, and the holding state is surely maintained. And an operator can perform switching (rotation) operation lightly and quickly. In addition, a penetrating arc-shaped slit into which the insertion member 32 can be easily inserted (inserted) thereafter is automatically formed along with the mutual locking, and the insertion (insertion) operation of the next insertion member 32 is performed. Can be done smoothly. That is, the process of arrows N → M → P shown in FIG. 18 can be performed smoothly.

Further, the insertion member 32 integrally includes a C-shaped or closed annular basic ring portion 33 and a plurality of projecting pieces 81, 82, 83, 84 protruding in the axial direction from the basic annular portion 33. And the projecting pieces 81, 82, 83, 84 of the insertion member 32 are in the locked state of the locking means 100, and the arc-shaped slit portion 25 of the press-holding ring 3 and the joint body 10 are Since it is inserted into the smooth arc-shaped bottom surface portion 20 to prevent the pressing and holding ring 3 from rotating in the reverse direction, the holding state by the locking means 100 is maintained. Easily inserts the pressure retaining ring 3 and contributes to the realization of quick pipe connection work and the prevention of fluid leakage due to unexpected separation.
Further, since at least one of the plurality of projecting pieces 81, 82, 83, 84 is provided with the retaining pawl 88 or the retaining pawl piece 88B, the insertion member 32 is unexpectedly inserted. The disconnection of the pipe is prevented and the pipe connection completion state is maintained.

DESCRIPTION OF SYMBOLS 1, 2 Holding ring 3 Press holding ring 3A Inner peripheral part 3B Inner peripheral part outer end area 3C Tapered inner peripheral surface 4 Thin metal pipe (pipe)
4a tip 6,7 taper-shaped inner peripheral surface 9 (plastic processing) ridge 9A outer gradient surface 9B inner gradient surface
10 Fitting body
10A Tip outer periphery
10B Inner peripheral tip area
21 and 22
23 Locking groove
25 Arc-shaped slit
30 Arc-shaped inner ridge
32 Insertion member
40 skirt
41 Inner peripheral corner
81, 82, 83, 84
88 Locking claw
88B Locking claw piece

Claims (9)

A joint body (10), and a press-holding ring (3) attached to the joint body (10) in an outer fitting shape;
The thin metal tube (4) is provided with a plastic working protrusion (9) protruding in the circumferential direction intermittently or over the entire circumference,
The joint body (10) is fitted to the outer peripheral portion (10A) of the tip and the inner peripheral portion (3A) of the press-holding ring (3) by fitting of the press-holding ring (3) in the axial direction and in the radial direction. A locking means (100) for locking each other at a small angle,
By the locking means (100), the inner peripheral portion outer end region (3B) of the pressure holding ring (3) and the inner peripheral portion distal end region (10B) of the joint body (10) are connected to the metal tube (4). In order to maintain the holding state by the locking means (100), the pressing holding ring (3) A pipe joint structure comprising an insertion member (32) that is inserted from an axial direction and prevents rotation in a direction opposite to the small-angle rotation.   The outer peripheral surface (3B) of the inner peripheral portion of the press-holding ring (3) has a tapered inner peripheral surface (6) against the outer inclined surface (9A) of the ridge (9) of the metal tube (4). The pipe joint structure according to claim 1, corresponding to a closed annular holding ring (1).   A tapered inner peripheral surface (3C) formed in the outer peripheral area (3B) of the inner peripheral portion of the press-holding ring (3) with respect to the outer inclined surface (9A) of the ridge (9) of the metal tube (4). The pipe joint structure according to claim 1, which corresponds directly.   The inner peripheral surface tip region (10B) of the joint body (10) has a tapered inner peripheral surface (7) with respect to the inner inclined surface (9B) of the ridge (9) of the metal tube (4). The pipe joint structure according to claim 1, which corresponds via an annular holding ring (2).   The pipe joint according to claim 1, wherein the inner peripheral portion tip region (10B) of the joint body (10) directly corresponds to the inner sloped surface (9B) of the ridge (9) of the metal pipe (4). Construction.   The inner peripheral corner (41) of the inner peripheral tip end region (10B) of the joint body (10) with respect to the skirt (40) of the inner inclined surface (9B) of the ridge (9) of the metal pipe (4) The pipe joint structure according to claim 1, which is adapted to be in direct contact. In the joint body (10), a plurality of arc-shaped outer ridges (19) and smooth arc-shaped bottom surfaces (20) are arranged alternately on the outer periphery (10A) of the tip, and each arc-shaped outer The ridge (19) has a pair of outer ridges (21) (22) that form a locking groove (23) between them,
Further, in the press retaining ring (3), a small angle in the radial direction is formed on the inner circumferential portion (3A) of the locking groove portion (23) between the pair of outer protrusions (21) and (22). A plurality of arc-shaped inner ridges (30) that can be engaged by rotation are provided, and an arc-shaped slit (25) is inserted in the axial direction between adjacent inner ridges (30) (30). Set up
The pipe joint structure according to claim 1, wherein the locking means (100) includes a locking groove (23) and the arcuate inner ridge (30). The insertion member (32) includes a C-shaped or closed annular basic ring portion (33) and a plurality of projecting pieces (81), (82), (83) protruding in the axial direction from the basic ring portion (33). ) (84) integrally,
The projecting pieces (81), (82), (83), and (84) of the insertion member (32) are in the locked state of the locking means (100), and the arc-shaped slit portion ( 25) and the smooth arc bottom surface portion (20) of the joint body (10) to prevent the pressing and holding ring (3) from rotating in the reverse direction, The pipe joint structure according to claim 7, wherein the pipe joint structure is configured to maintain the holding state according to (100).   9. At least one of the plurality of protruding pieces (81), (82), (83), and (84) is provided with a retaining claw piece (88) or a locking claw piece portion (88B). The pipe joint structure described.

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