JP2023017204A - Pipe joint structure - Google Patents

Abstract

To provide a pipe joint structure formed by firmly and integrally coupling pipe joint bodies made of metal and plastic.SOLUTION: The pipe joint structure comprises a first body 1 made of metal and a second body 2 made of plastic. An outer periphery of the first body 1 has a protruding annular bulge part 14 and an annular concave groove 10. A proximal-most end part 21A of a cylindrical part 21 at a proximal end of the second body 2 is pressed into the concave groove 10.SELECTED DRAWING: Figure 1

Description

The present invention relates to a pipe joint structure.

The present inventor once proposed a pipe joint as shown in FIGS. 7 to 9 (see Patent Document 1).
A joint body 60 of a conventional pipe joint shown in FIGS. 7 to 9 includes a metal first body 54 having an insertion cylinder portion 52 to be inserted into the end of a pipe P to be connected, a tapered male thread 53, and the like, It comprises a plastic short cylindrical second body 56 fixed to the first body 54 so as to form an annular space 55 into which the pipe P is inserted.

The insertion cylinder part 52 is inserted into the hole of the pipe P (as shown in FIGS. 7 and 8), and the pipe P is squeezed by a C-shaped ring 57 having a notch in one part of the circumference to prevent the pipe P from coming off. In addition, as shown in FIG. 9, a retainer ring 58 made of a thin metal plate increases the retaining force of the pipe P. As shown in FIG. Further, the insertion cylinder portion 52 is formed with a sealing groove 61 in which an O-ring 59 is fitted, and accordingly, the thickness dimension of the insertion cylinder portion 52 is sufficiently large (thick).
Further, the retainer ring 58 is held (fixed) to the tip end surface of the second main body 56 by means of a cap 62 having an inner peripheral screw.

Japanese Patent No. 3411546

The conventional pipe joint shown in FIGS. 7 to 9 has a joint body 60 composed of a first body 54 made of metal and a second body 56 made of plastic whose strength is inferior to that of metal. Regardless, even under a situation where a large swaying force (moments M ₁ and M ₂ in FIG. 8) acts on the pipe P when the pipe connection is completed, the swaying force is not applied to the low-strength plastic second body 56. does not act on the connection portion (screw connection portion) 65 between the _second main body 56 and the _first main body 54. , are excellent pipe fittings.

However, the inventors have noticed that the conventional pipe joints shown in FIGS. 7 to 9 have the following problems.
(i) The minimum inner diameter D0 of the hole 52A of the insertion cylinder 52 is significantly smaller than the inner diameter _DP of the pipe _P , and therefore the passage resistance of the fluid flowing through the pipe P--- pressure loss--- (ii) The retaining ring 58 made of a thin plate piece is unstable in shape and posture, and the axial center of the ring 58 is unevenly distributed with respect to the pipe joint axial center during screwing operation of the cap 62. Or, it will be in an abnormal tilted posture and held between the cap 62 and the outer end surface of the second main body 56, and along with this, a large number of teeth 58A on the entire circumference are evenly distributed on the outer peripheral surface of the pipe P. (iii) (in other words) the problem that the retaining ring 58 is fixed in the state shown in FIG. 7, so that it cannot be "automatically centered" while contacting the outer peripheral surface of the pipe P when the pipe P is inserted. .

Accordingly, the present invention provides a pipe joint structure in which the joint body comprises a metal first body and a short cylindrical plastic second body into which a pipe to be connected is inserted and held; The main body has an inner cylindrical portion that is inserted into the proximal cylindrical portion of the second main body via a retaining mechanism; A protruding portion protrudes in the radial direction, and an annular groove into which the most proximal portion of the proximal cylindrical portion of the second body is inserted is formed in the annular protruding portion as an axial opening. It is

Further, the most proximal portion is press-fitted into the annular groove from the axial direction to prevent the axial center of the second main body from wobbling with respect to the axial center of the first main body. is configured as follows.
The metal first body has a tapered external thread, and the annular projecting portion is gripped by a work tool that applies rotational torque to screw the external thread into a female thread of another member. It has a hexagonal outer peripheral surface that
Further, the minimum inner diameter dimension of the assembly passage hole in the state where the pipe is inserted into the joint body and the pipe connection is completed is set substantially equal to the inner diameter dimension of the pipe.

Further, a pipe retainer ring is provided inside the second body of the joint body; the retainer ring is formed with a large number of tooth portions that engage with the outer peripheral surface of the pipe at regular intervals in the circumferential direction. an annular inclined surface plate portion on the inner peripheral side; an annular axis-orthogonal surface plate portion connected to the outer peripheral edge of the inclined surface plate portion; connected to the outer peripheral edge of the axis-orthogonal surface plate portion, a reinforcing cylindrical face plate portion that is bent in the same axial direction as the inclined face plate portion and faces the inner peripheral surface of the second main body;

A pressure-receiving fixing ring body having an inwardly expanding tapered surface portion is attached to the open end of the second main body; A C-shaped ring having a tapered surface portion, a plurality of pipe-biting claw portions formed on the inner peripheral surface, and a surface orthogonal to the axis center at the inner end in the axial direction, and having a cut at one place on the circumference. provided inside the second main body; the plate portion of the retainer ring orthogonal to the axis and the surface orthogonal to the axis of the C-shaped ring are arranged so as to be able to face each other; a pipe pulling force is applied; When this is done, the anti-separation ring and the C-shaped ring work together to exert a force to prevent the pipe from being pulled out.

Further, a pipe retainer ring is provided inside the second body of the joint body; the retainer ring is formed with a large number of tooth portions that engage with the outer peripheral surface of the pipe at regular intervals in the circumferential direction. and an annular inclined surface plate portion on the inner peripheral side; and an annular axis-perpendicular surface plate portion connected to the outer peripheral edge of the inclined surface plate portion; , a pressure-receiving fixing ring body having an inner diameter-expanding tapered surface part; an outer diameter-reducing tapered surface part slidably abutting against the tapered surface part of the pressure-receiving fixing ring body; A C-shaped ring having a plurality of pipe-biting claws and a surface orthogonal to the axial center at the inner end in the axial direction and having a cut at one place on the circumference is provided inside the second main body; and the axially orthogonal surface of the C-ring are arranged in contact with each other in a face-to-face manner; It is constructed so that the pull-out prevention force of the pipe can be exerted by working together with the C-shaped ring.

According to the present invention, an axial through-hole having an inner diameter almost equal to that of the pipe can be formed, and the flow resistance (pressure loss) of the fluid can be significantly reduced. In addition, the metal first body and the plastic second body can be strongly and integrally joined together. Therefore, even if a large external force (moment) acts in the direction in which the axis of the pipe swings, the strength of the connection between the first main body and the second main body is large, and the pipe can withstand it sufficiently. In addition, inside the second main body, the retainer ring is centered so that the tooth portions are evenly pressed against the outer peripheral surface of the pipe over the entire circumference of 360°, maintaining a stable posture and ensuring , 360° evenly bite into the entire circumference to prevent the pipe from coming off.

It is a longitudinal section showing one embodiment of the present invention. It is a longitudinal cross-sectional view of a metal first body. FIG. 10 is a vertical cross-sectional view showing a second plastic main body and main accessories attached thereto; Fig. 3 shows an example of a pipe retaining ring, (A) is a front view, (B) is a cross-sectional view of (a-a) of (A), (C) is a rear view, and (D) is a right side view. It is a diagram. FIG. 4 is a cross-sectional view showing an example of a C-shaped ring; FIG. 4 is a vertical cross-sectional view of a second plastic body; It is a vertical cross-sectional view of a pipe unconnected state showing a conventional example. It is a vertical cross-sectional view of a pipe connection state showing a conventional example. A conventional example of a pipe retainer ring is shown, (A) is a side view of the state before bending, and (B) is a front cross-sectional view. 1 shows a modification of the present invention, where (A) is a longitudinal cross-sectional view of the whole, and (B) is an enlarged cross-sectional view of a main part.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below based on the illustrated embodiments.
In one embodiment of the present invention shown in FIGS. 1-3, P ₀ is a pipe to be connected, made of plastic material such as PEX, polybutene, or the like. Reference numeral 5 denotes a joint body, which includes a metal first body 1 and a short cylindrical plastic second body 2 into which a pipe P ₀ to be connected is inserted and held.

The first main body 1 has an inner cylindrical portion 11 that is inserted into the proximal end cylindrical portion 21 of the second main body 2 via a retainer mechanism 31 .
The retainer mechanism 31 includes a shallow circumferential concave groove 12 formed on the outer peripheral surface of the inner cylindrical portion 11 of the first main body 1 and a convex groove formed on the inner peripheral surface of the base end cylindrical portion 21 of the second main body 2 . It consists of a ridge 22 and a ridge 22.

Further, a seal groove 13 is formed in the vicinity of the groove 12 on the outer peripheral surface of the inner cylindrical portion 11, and an O-ring 32 is mounted thereon.
Further, in the first main body 1, at the base end position of the inner insertion tube portion 11, an annular projecting portion 14 projects in the radial direction. In addition, the annular projecting portion 14 is formed with the annular recessed groove 10 into which the most proximal portion 21A of the proximal cylindrical portion 21 of the second main body 2 is axially inserted.

As shown in FIGS. 1-3, the annular projection 14 has a hexagonal shape (as seen from the axial direction) or (having small non-slip grooves on the outer peripheral surface) for gripping a work tool such as a spanner. circular.
The annular groove 10 and the proximal end portion 21A each have a rectangular vertical cross-sectional shape. Furthermore, it is desirable to press-fit the most proximal portion 21A into the annular groove 10 from the axial direction (axial direction).

In other words, it is desirable that the inner and outer peripheral surfaces of the proximal end portion 21A are closely fitted to the inner and outer peripheral surfaces of the groove 10, respectively.
In this manner, the most proximal portion 21A of the proximal cylindrical portion 21 of the second body 2 made of plastic is press-fitted into the annular groove 10 of the first body 1 made of metal. As a result, it is possible to prevent the axial center L ₂ of the second main body 2 from wobbling with respect to the axial center L ₁ of the first main body 1 .

More specifically, the metal first body 1 has a tapered external thread 15. As shown in FIG.
Also, referring again to the annular protrusion 14, the illustrated annular protrusion 14 applies a rotational torque to screw the male thread 15 into a female thread formed in another member (not shown). It is desirable to have a hexagonal outer peripheral surface for gripping a work tool such as a wrench that imparts a .

Then, as shown in FIGS. 3 and 6, a tapered hole 23A, a medium-diameter hole 23B, a large-diameter hole 23C, and a screw hole 23D are sequentially formed in the axial direction ₍ arrow) K2 from the ridge 22. .
The tapered hole 23A is where the guide ring 33 shown in FIG. 1 (described below) is inserted and stops. Also, the outer peripheral surface of the tip of the inserted pipe _P0 corresponds to the middle diameter hole 23B. Two O-rings 34, 35 and a closed annular separate ring 36 interposed therebetween are inserted into the large-diameter hole 23C. Reference numeral 25 denotes a closed ring O-ring retaining ring having an outer peripheral thread, which is screwed into a screw hole 23D and fixed at the position shown in FIGS.

An O-ring retaining ring 25 is fixed inside the second main body 2 made of plastic, and further, a separate ring 36 is interposed to form a seal concave groove for accommodating two O-rings 34 and 35 .
A pipe retainer ring 37 and a C-shaped ring 38 are arranged in order outside the O-ring retaining ring 25 in the inner space of the screw hole 23D. Further, the pressure-receiving fixing ring body 39 is attached (screwed) to (the threaded hole 23D of) the open end portion 2A of the second main body 2 .

The pressure-receiving fixing ring body 39 has an inwardly expanding tapered surface portion 39A and an outer collar portion 39B that contacts the outer end surface 2B of the second main body 2. As shown in FIG.
The retainer ring 37 will be described below. As shown in FIG. 4, and FIGS. 1 and 3, the retaining ring 37 is manufactured by pressing a thin metal plate or the like, and furthermore, the retainer ring 37 has a large number of hooks (bites) on the outer peripheral surface of the pipe _P0 . The tooth portion 37A has an annular inclined surface plate portion 37B (on the inner peripheral side) formed at equal intervals in the circumferential direction.

Further, an annular axial center orthogonal face plate portion 37D is continuously provided to the outer peripheral edge 37C of the inclined face plate portion 37B.
Moreover, a reinforcing cylindrical face plate portion 37E is continuously provided on the outer peripheral edge of the axial center orthogonal face plate portion 37D.

This cylindrical face plate portion 37E is bent in the same axial direction _K37 as the inclined face plate portion 37B closer to the inner diameter. In other words, the cylindrical face plate portion 37E, the inclined face plate portion 37B, and the axially orthogonal face plate portion 37D form a circular groove 37F that is open in the axial direction _K37 .

As shown in FIGS. 1 and 3, the inner peripheral surface of the hole portion 23 of the second main body 2 ---- more specifically, the inner peripheral surface of the screw hole 23D --- is provided with the reinforcement for the pipe retaining ring 37. As shown in FIGS. The cylindrical face plate portion 37E faces (faces).
As shown in FIG. 3, when the pipe _P0 is not inserted, the pipe retainer ring 37 is not fixed and can be slightly moved (with very small dimensions) in the radial and axial directions. In addition, as the pipe _P0 is inserted, the pipe retainer ring 37 is automatically centered, and the teeth 37A can bite (abut against) evenly through 360°. can.

Next, as shown in FIGS. 1 and 3, the opening end portion 2A of the second main body 2 is provided with a pressure-receiving fixing ring body 39 having an inwardly expanding tapered surface portion 39A. A C-shaped ring 38 having an outer diameter-reduced tapered surface portion 38A slidably abutting against the tapered surface portion 39A of the ring body 39 and having a cut 38B at one circumferential location is provided inside the second body 2. ing.
Further, the C-shaped ring 38 has a plurality of pipe biting claws 38C on its inner peripheral surface, and the tips of the claws 38C are inclined axially inwardly to bite into the outer peripheral surface of the pipe _P0 . to prevent the pipe P ₀ from being pulled out in the axial outward direction.

Further, this C-shaped ring 38 has an axial center perpendicular surface 38E at the inner end in the axial direction (see FIG. 5).
Then, as shown in FIGS. 1 and 3, the plate portion 37D (see FIG. 4) of the retainer ring 37 and the perpendicular surface 38E (see FIG. 5) of the C-shaped ring 38 are arranged to face each other. It is arranged inside the second main body 2 so as to abut against it.

In FIG. ₁ , when the pipe pull-out force K _P acts, the tooth portion 37A of the retainer ring 37 bites into the outer peripheral surface of the pipe P0, and at the same time, the C-shaped ring 38 is contracted and deformed while its claw portion 38C, 38C bites into the outer peripheral surface of the pipe _P0 , whereby the retaining ring 37 and the C-shaped ring 38 work together to exhibit a large pipe pulling-out preventing force.

Also, in FIG. ₁ , when inserting the pipe P0, the outer peripheral surface is tapered or tapered to prevent the O-rings 34 and 35 from being damaged by the cut edge of the pipe. A guide ring 33 is inserted with the pipe P ₀ .

Moreover, the guide ring 33 is fixed to the outer peripheral surface of the distal end of the thin short cylindrical body (inner core) 27 for smooth insertion of the guide ring 33 and reinforcement of the pipe _P0 after insertion. ing. By reinforcing the inner peripheral surface of the pipe P ₀ described above, the plastic material is sufficiently resistant to the radially inward force when the tooth portion 37A of the ring 37 and the claw portion 38C of the C-shaped ring 38 bite into the outer peripheral surface of the pipe. The manufactured pipe P ₀ has a bearing role.

Next, FIG. 10 shows a modification of the present invention.
Conventionally, the retainer ring 58 is fixed inside the pipe joint, and the axially orthogonal face plate portion 58D (see FIG. 9) near the outermost periphery is fixedly held by a cap 62 or the like so as not to move in the axial direction. It was fixed in the axial direction.

On the other hand, in the modified example shown in FIG. 10, the retainer ring 58 can move along with the C-shaped ring 38 by a minute dimension in the axial direction.
10, a pipe retainer ring 58 is provided inside the second body 2 of the joint body 5, and this retainer ring 58 (as shown in FIGS. 10 and 9) 2) A large number of toothed portions 58A hooked on the outer peripheral surface of the pipe P have an annular inclined surface plate portion 58B on the inner peripheral side formed in the circumferential direction.

Furthermore, as shown in FIG. 9, there is an annular axially orthogonal face plate portion 58D that is connected to the outer peripheral edge 58C of the inclined face plate portion 58B.
On the other hand, a pressure-receiving fixing ring body 39 having a tapered surface portion 39A is attached (screwed) to the open end portion 2A of the second main body 2. As shown in FIG.

Further, an outer tapered surface portion 38A with a reduced diameter that slidably abuts on the tapered surface portion 39A of the pressure receiving fixing ring body 39, a plurality of pipe biting claw portions 38C formed on the inner peripheral surface, and an axial direction. A C-shaped ring 38 having an inner end perpendicular to the axis 38E and having a cut 38B at one place on the circumference is provided inside the second body 2 (see FIG. 5).

Then, the plate portion 58D of the retainer ring 58 perpendicular to the axis and the surface 38E of the C-shaped ring 38 perpendicular to the axis are brought into face-to-face contact (see FIG. 10B), and arranged as shown in FIG. do.
When the pipe pull-out force K _P acts, the pull-out preventive force of the pipe pull-out is exerted by the combined action of the pull-out prevention ring 58 and the C-shaped ring 38 .

By the way, as shown in FIG. 10(A), an O-ring retaining ring 25Z (for receiving the O-ring 35) is screwed in the same manner as in FIG. are different. That is, the O-ring retaining ring 25Z has a notch recess 25X (in a rectangular shape) so that the tooth portion 58A of the retainer ring ₅₈ can swing in the direction of the arrow M58 in FIG. 10(B). Although not shown, it may be desirable to set the cross-sectional shape of the notch recess 25X to a quarter-circular shape, a triangular shape, or the like.

In addition, in the pipe joint structure of the present invention, there is no intrusion member inside the pipe _P0 other than the short cylindrical body (inner core) 27 of the thin-walled pipe inserted into the pipe _P0 . However, as is clear, the minimum inner diameter dimension _D50min of the assembled passage hole 50 in the pipe connection completed state where the pipe P0 is inserted into the joint body ₅ is substantially equal to the inner diameter dimension _Dp of the pipe _P0 . Therefore, the pressure loss (passage resistance) when the fluid passes through the pipe joint structure according to the present invention can be extremely small.

In FIG. 8 of the conventional example, the wall thickness of the insertion tube portion 52 is large, the minimum inner diameter _D0 is significantly smaller than the pipe inner diameter dimension _Dp , and the pressure loss (flow resistance) of the fluid increases. In comparison with the above point, it is clear that the fluid pressure loss (passage resistance) can be significantly reduced in the present invention regardless of the provision of the second body 2 made of plastic. deaf.

In the present invention, as described in detail above, the joint body 5 comprises the metal first body 1 and the short cylindrical plastic second body ₂ into which the pipe to be connected P0 is inserted and held. In the pipe joint structure; the first main body 1 has an inner cylindrical portion 11 which is inserted into the base end cylindrical portion 21 of the second main body 2 via a retainer mechanism 31; At the base end position of the inner insertion cylinder portion 11 in the main body 1, an annular projecting portion 14 is protruded in the radial direction, and the proximal end portion 21A of the base end cylindrical portion 21 of the second main body 2 is provided. Since the annular recessed groove ₁₀ into which is inserted is formed in the annular projecting portion 14 as an opening in the axial direction, in _FIG . moment) acts on the pipe P ₀ , the moments M ₁ and M ₂ temporarily act on the second body 2 made of plastic, but are sufficiently reinforced (supported) by the first body 1 made of metal. . That is, the most proximal portion 21A of the second plastic main body 2 is inserted into the annular groove 10 of the first metal main body 1, and the inner insertion cylinder portion 11 of the first metal main body 1 is inserted. By being inserted in the second plastic body 2, the low-strength plastic second body 2 is firmly and stably integrally coupled with the high-strength metal first body 1, thereby forming a pipe. The pipe joint as a whole can sufficiently withstand the large moments M ₁ and M ₂ acting on P ₀ .
In particular, as shown in FIGS. 7 and 8 of the conventional example, the structure is not such that the moments M ₁ and M ₂ acting on the pipe P directly act on (the insertion cylindrical portion 52 of) the first metal body 54. In the pipe joint structure of the present invention, it can be said that the plastic part is cleverly joined to the metal part.

Further, according to the present invention, the most proximal end portion 21A is press-fitted into the annular groove 10 from the axial direction so that the axis of the second body 2 is aligned with the axis L1 of the first body ₁ . Since the core L2 is configured to prevent core runout, even if _an external force (moment M1, _M2 ) causing core _runout acts on the pipe P0, the low-strength plastic _second main body 2 to the high-strength first main body 1, and assembly and connection work can be easily and quickly performed.

The first metal body 1 has a tapered external thread 15, and the annular projecting portion 14 applies rotational torque to screw the external thread 15 into a female thread of another member. Since the tool has a hexagonal outer peripheral surface to grip, there is no need to provide a separate (special) protrusion on the outer periphery of the first body 1 . In other words, the work tool gripping portion that is essential for screwing the tapered male screw 15 to another member can be used, and the compactness and simplification of the shape of the first main body 1 can be achieved.

In addition, since the minimum inner diameter dimension _D50min of the assembly passage hole 50 in the pipe connection completed state where the pipe P0 is inserted into the joint body ₅ is set substantially equal to the inner diameter dimension _Dp of the pipe _P0 , There is an advantage that the passage resistance (pressure loss) when the fluid passes is small. In particular, when compared with the conventional example shown in FIG. 8, it is clear that a significant reduction in fluid flow resistance can be achieved.

Further, a pipe retainer ring 37 is provided inside the second body ₂ of the joint body 5; an annular inclined surface plate portion 37B on the inner peripheral side formed at equal intervals in the direction; an annular axis-orthogonal surface plate portion 37D connected to the outer peripheral edge 37C of the inclined surface plate portion 37B; a reinforcing cylindrical face plate portion 37E connected to the outer peripheral edge of the orthogonal face plate portion _37D , bent in the same axial direction K37 as the inclined face plate portion 37B, and opposed to the inner peripheral face of the second main body 2; A storage space 8 having a rectangular vertical cross section is formed by the inner peripheral surface of the second main body ₂ , the outer peripheral surface of the inserted pipe P0, and built-in parts such as the ring 25 and the C-shaped ring 38. It can be embedded within (see FIG. 1) as being micro-movable axially and radially. Along with this, the pipe retaining ring 37 of the present invention is arranged so that the ring axis L ₃₇ coincides with the (pipe) axis L ₀ of the pipe P ₀ and the axis L ₂ of the second body 2 . , to exert an automatic centering function.
Therefore, all the tooth portions 37A press evenly (uniformly) over 360° against the outer peripheral surface of the inserted pipe _P0 and bite into it, and all the tooth portions 37A stably and excellently prevent the pipe from being pulled out. exert power.
Further, the pipe retainer ring 37 (see FIG. 4) according to the present invention has higher overall rigidity (as a material of the same plate thickness) than the retainer ring 58 shown in FIG. 9 (FIG. 8) of the conventional example. Since it is high and is less likely to be distorted, it can smoothly move in the axial direction and the radial direction within the rectangular storage space 8 to perform an automatic centering function, and all the tooth portions 37A can be adjusted over 360°. However, it can bite in evenly and can exhibit an excellent pipe pull-out prevention force.
There is a risk that the retainer ring 58 shown in FIGS. 8 and 9 showing a conventional example may be incorporated into the cap 62 in a deformed posture under strain and in a radially displaced state. The axial center of the incoming pipe P and the axial center of the retainer ring 58 are not aligned (not centered), and only a part of all the teeth 58A over 360° bites into the outer peripheral surface of the pipe P. There was a risk that the pipe withdrawal prevention force would be insufficient.
In the present invention, such conventional problems can be solved, the automatic centering function can be exhibited, and a large and stable pipe pull-out preventing force can be exhibited. Moreover, there is an advantage that compactness in the radial direction can also be achieved (clear by comparing FIG. 4 with FIG. 9).

Further, according to the present invention, the opening end portion 2A of the second main body 2 is provided with a pressure receiving fixing ring body 39 having an inwardly expanding tapered surface portion 39A; It has an outer reduced diameter tapered surface portion 38A that slidably abuts, a plurality of pipe biting claw portions 38C formed on the inner peripheral surface, and an axial center orthogonal surface 38E at the inner end in the axial direction, A C-shaped ring 38 having a cut 38B at one place on the circumference is provided inside the second main body 2; 38E and 38E are placed in face-to-face contact with each other; when the pipe pull-out force K _P acts, the pull-out preventing force is Since it is constructed so as to exert a large pipe pull-out preventing force by working together. Moreover, as is clear from FIG. 1, the internal storage space can be extremely small. In particular, since the retainer ring 37 is incorporated in the second main body 2 with the axis-perpendicular surface plate portion 37D of the retainer ring 37 and the axis-perpendicular surface 38E of the C-shaped ring 38 in face-to-face contact, the retainer ring The radial inward and outward movement of 37 and the radial inward and outward movement of C-ring 38, respectively, are unimpeded and smooth. Therefore, each of the retaining ring 37 and the C-shaped ring 38 exerts its own pipe pull-out preventing force, and can exert a large overall pipe pull-out preventing force.

Further, in the present invention, a pipe retainer ring 58 is provided inside the second body ₂ of the joint body 5; 58A includes an inner circumferential annular inclined surface plate portion 58B formed at equal intervals in the circumferential direction; A pressure receiving fixing ring body 39 having an inwardly expanding tapered surface portion 39A is attached to the opening end portion 2A of the second main body 2; It has an outer diameter-reduced tapered surface portion 38A that movably abuts, a plurality of pipe-biting claw portions 38C formed on the inner peripheral surface, and an axial-center orthogonal surface 38E at the inner end in the axial direction. A C-shaped ring 38 having a cut 38B at one circumferential location is provided inside the second main body 2; When the pipe pull-out force K _P acts, the pull-out preventing force is exerted by the combined action of the pull-out prevention ring 58 and the C-shaped ring 38. Since it is configured to do so, the retaining ring 58 can be automatically centered in a minute dimension in the radial direction, and the tooth portion 58A can stably and evenly bite in over 360° of the outer peripheral surface of the pipe, which is excellent. It can demonstrate the ability to prevent pipe pull-out. Moreover, the retainer ring 58 and the C-shaped ring 38 move radially inwardly and radially outwardly in minute dimensions, respectively, and exert sufficient force to prevent the pipe from being pulled out without interfering with each other.

REFERENCE SIGNS LIST 1 first main body 2 second main body 2A open end 5 joint main body
10 Annular groove
11 Inner insertion tube
14 Annular protrusion
15 Tapered male thread
21 Proximal barrel
21A Most proximal site
31 Retaining mechanism
37 Pipe retainer ring
37A Tooth
37B Inclined face plate
37C Outer edge
37D Axis orthogonal face plate
37E Reinforcing cylindrical face plate
38 C-shaped ring
38A Outer reduced diameter tapered surface
38B cut
38C Claw for biting pipe
38E plane perpendicular to the axis
39 Pressure receiving fixing ring body
39A Inwardly expanding tapered surface
50 Assembled channel hole
58 Retaining ring
58A Tooth
58B Annular inclined surface plate portion
58C outer edge
58D Axial orthogonal face plate part D _P inner diameter dimension D _50min minimum inner diameter dimension K ₃₇ Axial direction K _P pipe pull-out force L ₁ axis center L ₂ axis center P ₀ pipe

The present invention relates to a pipe joint structure.

The present inventor once proposed a pipe joint as shown in FIGS. 7 to 9 (see Patent Document 1).
A joint body 60 of a conventional pipe joint shown in FIGS. 7 to 9 includes a metal first body 54 having an insertion cylinder portion 52 to be inserted into the end of a pipe P to be connected, a tapered male thread 53, and the like, It comprises a plastic short cylindrical second body 56 fixed to the first body 54 so as to form an annular space 55 into which the pipe P is inserted.

The insertion cylinder part 52 is inserted into the hole of the pipe P (as shown in FIGS. 7 and 8), and the pipe P is squeezed by a C-shaped ring 57 having a notch in one part of the circumference to prevent the pipe P from coming off. In addition, as shown in FIG. 9, a retainer ring 58 made of a thin metal plate increases the retaining force of the pipe P. As shown in FIG. Further, the insertion cylinder portion 52 is formed with a sealing groove 61 in which an O-ring 59 is fitted, and accordingly, the thickness dimension of the insertion cylinder portion 52 is sufficiently large (thick).
Further, the retainer ring 58 is held (fixed) to the tip end surface of the second main body 56 by means of a cap 62 having an inner peripheral screw.

Japanese Patent No. 3411546

The conventional pipe joint shown in FIGS. 7 to 9 has a joint body 60 composed of a first body 54 made of metal and a second body 56 made of plastic whose strength is inferior to that of metal. Regardless, even under a situation where a large swaying force (moments M ₁ and M ₂ in FIG. 8) acts on the pipe P when the pipe connection is completed, the swaying force is not applied to the low-strength plastic second body 56. does not act on the connection portion (screw connection portion) 65 between the _second main body 56 and the _first main body 54. , are excellent pipe fittings.

However, the inventors have noticed that the conventional pipe joints shown in FIGS. 7 to 9 have the following problems.
(i) The minimum inner diameter D0 of the hole 52A of the insertion cylinder 52 is significantly smaller than the inner diameter _DP of the pipe _P , and therefore the passage resistance of the fluid flowing through the pipe P--- pressure loss--- (ii) The retaining ring 58 made of a thin plate piece is unstable in shape and posture, and the axial center of the ring 58 is unevenly distributed with respect to the pipe joint axial center during screwing operation of the cap 62. Or, it will be in an abnormal tilted posture and held between the cap 62 and the outer end surface of the second main body 56, and along with this, a large number of teeth 58A on the entire circumference are evenly distributed on the outer peripheral surface of the pipe P. (iii) (in other words) the problem that the retaining ring 58 is fixed in the state shown in FIG. 7, so that it cannot be "automatically centered" while contacting the outer peripheral surface of the pipe P when the pipe P is inserted. .

Accordingly, the present invention provides a pipe joint structure in which the joint body comprises a metal first body and a short cylindrical plastic second body into which a pipe to be connected is inserted and held; The main body has an inner cylindrical portion that is inserted into the proximal cylindrical portion of the second main body via a retaining mechanism; A protruding portion protrudes in the radial direction, and an annular groove into which the most proximal portion of the proximal cylindrical portion of the second body is inserted is formed in the annular protruding portion as an axial opening. A pipe retainer ring is provided inside the second body of the joint body; the retainer ring includes a large number of teeth that engage with the outer peripheral surface of the pipe at regular intervals in the circumferential direction. an annular inclined surface plate portion on the inner peripheral side; an annular axis-orthogonal surface plate portion connected to the outer peripheral edge of the inclined surface plate portion; connected to the outer peripheral edge of the axis-orthogonal surface plate portion, a reinforcing cylindrical face plate portion that is bent in the same axial direction as the inclined face plate portion and faces the inner peripheral surface of the second main body;

A pressure-receiving fixing ring body having an inwardly expanding tapered surface portion is attached to the open end of the second main body; A C-shaped ring having a radially tapered surface portion, a plurality of pipe-biting claw portions formed on the inner peripheral surface, and a surface perpendicular to the axis at the inner end in the axial direction, and having a cut at one place on the circumference, Provided inside the second main body; the plate portion perpendicular to the axial center of the retainer ring and the perpendicular surface of the C-shaped ring are arranged so as to be able to face each other; When acted, the anti-separation ring and the C-shaped ring work together to exert a force to prevent the pipe from being pulled out.

Further, in a pipe joint structure in which the joint body comprises a metal first body and a short cylindrical plastic second body into which a pipe to be connected is inserted and held; It has an inner cylindrical portion that is inserted into the proximal end cylindrical portion of the second main body via a retaining mechanism; the inner cylindrical portion of the first main body has an annular projecting portion at the proximal end position. an annular recess projecting in the radial direction and into which the most proximal end portion of the proximal cylindrical portion of the second body is inserted is formed in the annular projecting portion so as to be axially open; A pipe retainer ring is provided inside the second main body of the main body; the retainer ring has an inner periphery formed with a large number of tooth portions that engage with the outer peripheral surface of the pipe at equal intervals in the circumferential direction. and a circular annular inclined surface plate portion connected to the outer peripheral edge of the inclined surface plate portion; A pressure-receiving fixing ring body having a radial tapered surface portion is provided; an outer tapered surface portion with a reduced diameter that slidably abuts against the tapered surface portion of the pressure-receiving fixing ring body; a C-shaped ring having an inserting claw portion and an axially inner end perpendicular to the axis, and having a cut at one place on the circumference thereof; provided inside the second body; The orthogonal face plate portion and the axial center orthogonal surface of the C-shaped ring are disposed so as to face each other; By working together, it is configured to exert a pipe pull-out prevention force.

According to the present invention, an axial through-hole having an inner diameter almost equal to that of the pipe can be formed, and the flow resistance (pressure loss) of the fluid can be significantly reduced. In addition, the metal first body and the plastic second body can be strongly and integrally joined together. Therefore, even if a large external force (moment) acts in the direction in which the axis of the pipe swings, the strength of the connection between the first main body and the second main body is large and can be sufficiently withstood. In addition, inside the second main body, the retainer ring is centered so that the tooth portions are evenly pressed against the outer peripheral surface of the pipe over the entire 360° circumference, maintaining a stable posture and ensuring , 360° evenly bite into the entire circumference to prevent the pipe from coming off.

It is a longitudinal section showing one embodiment of the present invention. It is a longitudinal cross-sectional view of a metal first body. FIG. 10 is a vertical cross-sectional view showing a second plastic main body and main accessories attached thereto; Fig. 3 shows an example of a pipe retaining ring, (A) is a front view, (B) is a cross-sectional view of (a-a) of (A), (C) is a rear view, and (D) is a right side view. It is a diagram. FIG. 4 is a cross-sectional view showing an example of a C-shaped ring; FIG. 4 is a vertical cross-sectional view of a second plastic body; It is a vertical cross-sectional view of a pipe unconnected state showing a conventional example. It is a vertical cross-sectional view of a pipe connection state showing a conventional example. A conventional example of a pipe retainer ring is shown, (A) is a side view of the state before bending, and (B) is a front cross-sectional view. 1 shows a modification of the present invention, where (A) is a longitudinal cross-sectional view of the whole, and (B) is an enlarged cross-sectional view of a main part.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below based on the illustrated embodiments.
In one embodiment of the present invention shown in FIGS. 1-3, P ₀ is a pipe to be connected, made of plastic material such as PEX, polybutene, or the like. Reference numeral 5 denotes a joint body, which includes a metal first body 1 and a short cylindrical plastic second body 2 into which a pipe P ₀ to be connected is inserted and held.

The first main body 1 has an inner cylindrical portion 11 that is inserted into the proximal end cylindrical portion 21 of the second main body 2 via a retainer mechanism 31 .
The retainer mechanism 31 includes a shallow circumferential concave groove 12 formed on the outer peripheral surface of the inner cylindrical portion 11 of the first main body 1 and a convex groove formed on the inner peripheral surface of the base end cylindrical portion 21 of the second main body 2 . It consists of a ridge 22 and a ridge 22.

Further, a seal groove 13 is formed in the vicinity of the groove 12 on the outer peripheral surface of the inner cylindrical portion 11, and an O-ring 32 is mounted thereon.
Further, in the first main body 1, at the base end position of the inner insertion tube portion 11, an annular projecting portion 14 projects in the radial direction. In addition, the annular projecting portion 14 is formed with the annular recessed groove 10 into which the most proximal portion 21A of the proximal cylindrical portion 21 of the second main body 2 is axially inserted.

As shown in FIGS. 1-3, the annular projection 14 has a hexagonal shape (as seen from the axial direction) or (having small non-slip grooves on the outer peripheral surface) for gripping a work tool such as a spanner. circular.
The annular groove 10 and the proximal end portion 21A each have a rectangular vertical cross-sectional shape. Furthermore, it is desirable to press-fit the most proximal portion 21A into the annular groove 10 from the axial direction (axial direction).

In other words, it is desirable that the inner and outer peripheral surfaces of the proximal end portion 21A are closely fitted to the inner and outer peripheral surfaces of the groove 10, respectively.
In this manner, the most proximal portion 21A of the proximal cylindrical portion 21 of the second body 2 made of plastic is press-fitted into the annular groove 10 of the first body 1 made of metal. As a result, it is possible to prevent the axial center L ₂ of the second main body 2 from wobbling with respect to the axial center L ₁ of the first main body 1 .

More specifically, the metal first body 1 has a tapered external thread 15. As shown in FIG.
Also, referring again to the annular protrusion 14, the illustrated annular protrusion 14 applies a rotational torque to screw the male thread 15 into a female thread formed in another member (not shown). It is desirable to have a hexagonal outer peripheral surface for gripping a work tool such as a wrench that imparts a .

Then, as shown in FIGS. 3 and 6, a tapered hole 23A, a medium-diameter hole 23B, a large-diameter hole 23C, and a screw hole 23D are sequentially formed in the axial direction ₍ arrow) K2 from the ridge 22. .
The tapered hole 23A is where the guide ring 33 shown in FIG. 1 (described below) is inserted and stops. Also, the outer peripheral surface of the tip of the inserted pipe _P0 corresponds to the middle diameter hole 23B. Two O-rings 34, 35 and a closed annular separate ring 36 interposed therebetween are inserted into the large-diameter hole 23C. Reference numeral 25 denotes a closed ring O-ring retaining ring having an outer peripheral thread, which is screwed into a screw hole 23D and fixed at the position shown in FIGS.

An O-ring retaining ring 25 is fixed inside the second main body 2 made of plastic, and further, a separate ring 36 is interposed to form a seal concave groove for accommodating two O-rings 34 and 35 .
A pipe retainer ring 37 and a C-shaped ring 38 are arranged in order outside the O-ring retaining ring 25 in the inner space of the screw hole 23D. Further, the pressure-receiving fixing ring body 39 is attached (screwed) to (the threaded hole 23D of) the open end portion 2A of the second main body 2 .

The pressure-receiving fixing ring body 39 has an inwardly expanding tapered surface portion 39A and an outer collar portion 39B that contacts the outer end surface 2B of the second main body 2. As shown in FIG.
The retainer ring 37 will be described below. As shown in FIG. 4, and FIGS. 1 and 3, the retaining ring 37 is manufactured by pressing a thin metal plate or the like, and furthermore, the retainer ring 37 has a large number of hooks (bites) on the outer peripheral surface of the pipe _P0 . The tooth portion 37A has an annular inclined surface plate portion 37B (on the inner peripheral side) formed at equal intervals in the circumferential direction.

Further, an annular axial center orthogonal face plate portion 37D is continuously provided to the outer peripheral edge 37C of the inclined face plate portion 37B.
Moreover, a reinforcing cylindrical face plate portion 37E is continuously provided on the outer peripheral edge of the axial center orthogonal face plate portion 37D.

This cylindrical face plate portion 37E is bent in the same axial direction _K37 as the inclined face plate portion 37B closer to the inner diameter. In other words, the cylindrical face plate portion 37E, the inclined face plate portion 37B, and the axially orthogonal face plate portion 37D form a circular groove 37F that is open in the axial direction _K37 .

As shown in FIGS. 1 and 3, the inner peripheral surface of the hole portion 23 of the second main body 2 ---- more specifically, the inner peripheral surface of the screw hole 23D --- is provided with the reinforcement for the pipe retaining ring 37. As shown in FIGS. The cylindrical face plate portion 37E faces (faces).
As shown in FIG. 3, when the pipe _P0 is not inserted, the pipe retainer ring 37 is not fixed and can be slightly moved (with very small dimensions) in the radial and axial directions. In addition, as the pipe _P0 is inserted, the pipe retainer ring 37 is automatically centered, and the teeth 37A can bite (abut against) evenly through 360°. can.

Next, as shown in FIGS. 1 and 3, the opening end portion 2A of the second main body 2 is provided with a pressure-receiving fixing ring body 39 having an inwardly expanding tapered surface portion 39A. A C-shaped ring 38 having an outer diameter-reduced tapered surface portion 38A slidably abutting against the tapered surface portion 39A of the ring body 39 and having a cut 38B at one circumferential location is provided inside the second body 2. ing.
Further, the C-shaped ring 38 has a plurality of pipe biting claws 38C on its inner peripheral surface, and the tips of the claws 38C are inclined axially inwardly to bite into the outer peripheral surface of the pipe _P0 . to prevent the pipe P ₀ from being pulled out in the axial outward direction.

Further, this C-shaped ring 38 has an axial center perpendicular surface 38E at the inner end in the axial direction (see FIG. 5).
Then, as shown in FIGS. 1 and 3, the plate portion 37D (see FIG. 4) of the retainer ring 37 and the perpendicular surface 38E (see FIG. 5) of the C-shaped ring 38 are arranged to face each other. It is arranged inside the second main body 2 so as to abut against it.

In FIG. ₁ , when the pipe pull-out force K _P acts, the tooth portion 37A of the retainer ring 37 bites into the outer peripheral surface of the pipe P0, and at the same time, the C-shaped ring 38 is contracted and deformed while its claw portion 38C, 38C bites into the outer peripheral surface of the pipe _P0 , whereby the retaining ring 37 and the C-shaped ring 38 work together to exhibit a large pipe pulling-out preventing force.

Also, in FIG. ₁ , when inserting the pipe P0, the outer peripheral surface is tapered or tapered to prevent the O-rings 34 and 35 from being damaged by the cut edge of the pipe. A guide ring 33 is inserted with the pipe P ₀ .

Moreover, the guide ring 33 is fixed to the outer peripheral surface of the distal end of the thin short cylindrical body (inner core) 27 for smooth insertion of the guide ring 33 and reinforcement of the pipe _P0 after insertion. ing. By reinforcing the inner peripheral surface of the pipe P ₀ described above, the plastic material is sufficiently resistant to the radially inward force when the tooth portion 37A of the ring 37 and the claw portion 38C of the C-shaped ring 38 bite into the outer peripheral surface of the pipe. The manufactured pipe P ₀ has a bearing role.

Next, FIG. 10 shows a modification of the present invention.
Conventionally, the retainer ring 58 is fixed inside the pipe joint, and the axially orthogonal face plate portion 58D (see FIG. 9) near the outermost periphery is fixedly held by a cap 62 or the like so as not to move in the axial direction. It was fixed in the axial direction.

On the other hand, in the modified example shown in FIG. 10, the retainer ring 58 can move along with the C-shaped ring 38 by a minute dimension in the axial direction.
10, a pipe retainer ring 58 is provided inside the second body 2 of the joint body 5, and this retainer ring 58 (as shown in FIGS. 10 and 9) 2) A large number of toothed portions 58A hooked on the outer peripheral surface of the pipe P have an annular inclined surface plate portion 58B on the inner peripheral side formed in the circumferential direction.

Furthermore, as shown in FIG. 9, there is an annular axially orthogonal face plate portion 58D that is connected to the outer peripheral edge 58C of the inclined face plate portion 58B.
On the other hand, a pressure-receiving fixing ring body 39 having a tapered surface portion 39A is attached (screwed) to the open end portion 2A of the second main body 2. As shown in FIG.

Further, an outer tapered surface portion 38A with a reduced diameter that slidably abuts on the tapered surface portion 39A of the pressure receiving fixing ring body 39, a plurality of pipe biting claw portions 38C formed on the inner peripheral surface, and an axial direction. A C-shaped ring 38 having an inner end perpendicular to the axis 38E and having a cut 38B at one place on the circumference is provided inside the second body 2 (see FIG. 5).

Then, the plate portion 58D of the retainer ring 58 perpendicular to the axis and the surface 38E of the C-shaped ring 38 perpendicular to the axis are brought into face-to-face contact (see FIG. 10B), and arranged as shown in FIG. do.
When the pipe pull-out force K _P acts, the pull-out preventive force of the pipe pull-out is exerted by the combined action of the pull-out prevention ring 58 and the C-shaped ring 38 .

By the way, as shown in FIG. 10(A), an O-ring retaining ring 25Z (for receiving the O-ring 35) is screwed in the same manner as in FIG. are different. That is, the O-ring retaining ring 25Z has a notch recess 25X (in a rectangular shape) so that the tooth portion 58A of the retainer ring ₅₈ can swing in the direction of the arrow M58 in FIG. 10(B). Although not shown, it may be desirable to set the cross-sectional shape of the notch recess 25X to a quarter-circular shape, a triangular shape, or the like.

In addition, in the pipe joint structure of the present invention, there is no intrusion member inside the pipe _P0 other than the short cylindrical body (inner core) 27 of the thin-walled pipe inserted into the pipe _P0 . However, as is clear, the minimum inner diameter dimension _D50min of the assembled passage hole 50 in the pipe connection completed state where the pipe P0 is inserted into the joint body ₅ is substantially equal to the inner diameter dimension _Dp of the pipe _P0 . Therefore, the pressure loss (passage resistance) when the fluid passes through the pipe joint structure according to the present invention can be extremely small.

In FIG. 8 of the conventional example, the wall thickness of the insertion tube portion 52 is large, the minimum inner diameter _D0 is significantly smaller than the pipe inner diameter dimension _Dp , and the pressure loss (flow resistance) of the fluid increases. In comparison with the above point, it is clear that the fluid pressure loss (passage resistance) can be significantly reduced in the present invention regardless of the provision of the second body 2 made of plastic. deaf.

In the present invention, as described in detail above, the joint body 5 comprises the metal first body 1 and the short cylindrical plastic second body ₂ into which the pipe to be connected P0 is inserted and held. In the pipe joint structure; the first main body 1 has an inner cylindrical portion 11 which is inserted into the base end cylindrical portion 21 of the second main body 2 via a retainer mechanism 31; At the base end position of the inner insertion cylinder portion 11 in the main body 1, an annular projecting portion 14 is protruded in the radial direction, and the proximal end portion 21A of the base end cylindrical portion 21 of the second main body 2 is provided. Since the annular recessed groove ₁₀ into which is inserted is formed in the annular projecting portion 14 as an opening in the axial direction, in _FIG . moment) acts on the pipe P ₀ , the moments M ₁ and M ₂ temporarily act on the second body 2 made of plastic, but are sufficiently reinforced (supported) by the first body 1 made of metal. . That is, the most proximal portion 21A of the second plastic main body 2 is inserted into the annular groove 10 of the first metal main body 1, and the inner insertion cylinder portion 11 of the first metal main body 1 is inserted. By being inserted in the second plastic body 2, the low-strength plastic second body 2 is firmly and stably integrally coupled with the high-strength metal first body 1, thereby forming a pipe. The pipe joint as a whole can sufficiently withstand the large moments M ₁ and M ₂ acting on P ₀ .
In particular, as shown in FIGS. 7 and 8 of the conventional example, the structure is not such that the moments M ₁ and M ₂ acting on the pipe P directly act on (the insertion cylindrical portion 52 of) the first metal body 54. In the pipe joint structure of the present invention, it can be said that the plastic part is cleverly joined to the metal part.

Further, according to the present invention, the most proximal end portion 21A is press-fitted into the annular groove 10 from the axial direction so that the axis of the second body 2 is aligned with the axis L1 of the first body ₁ . Since the core L2 is configured to prevent core runout, even if _an external force (moment M1, _M2 ) causing core _runout acts on the pipe P0, the low-strength plastic _second main body 2 to the high-strength first main body 1, and assembly and connection work can be easily and quickly performed.

The first metal body 1 has a tapered external thread 15, and the annular projecting portion 14 applies rotational torque to screw the external thread 15 into a female thread of another member. Since the tool has a hexagonal outer peripheral surface to grip, there is no need to provide a separate (special) protrusion on the outer periphery of the first body 1 . In other words, the work tool gripping portion that is essential for screwing the tapered male screw 15 to another member can be used, and the compactness and simplification of the shape of the first main body 1 can be achieved.

In addition, since the minimum inner diameter dimension _D50min of the assembly passage hole 50 in the pipe connection completed state where the pipe P0 is inserted into the joint body ₅ is set substantially equal to the inner diameter dimension _Dp of the pipe _P0 , There is an advantage that the passage resistance (pressure loss) when the fluid passes is small. In particular, when compared with the conventional example shown in FIG. 8, it is clear that a significant reduction in fluid flow resistance can be achieved.

Further, a pipe retainer ring 37 is provided inside the second body ₂ of the joint body 5; an annular inclined surface plate portion 37B on the inner peripheral side formed at equal intervals in the direction; an annular axis-orthogonal surface plate portion 37D connected to the outer peripheral edge 37C of the inclined surface plate portion 37B; a reinforcing cylindrical face plate portion 37E connected to the outer peripheral edge of the orthogonal face plate portion _37D , bent in the same axial direction K37 as the inclined face plate portion 37B, and opposed to the inner peripheral face of the second main body 2; A storage space 8 having a rectangular vertical cross section is formed by the inner peripheral surface of the second main body ₂ , the outer peripheral surface of the inserted pipe P0, and built-in parts such as the ring 25 and the C-shaped ring 38. It can be embedded within (see FIG. 1) as being micro-movable axially and radially. Along with this, the pipe retaining ring 37 of the present invention is arranged so that the ring axis L ₃₇ coincides with the (pipe) axis L ₀ of the pipe P ₀ and the axis L ₂ of the second body 2 . , to exert an automatic centering function.
Therefore, all the tooth portions 37A press evenly (uniformly) over 360° against the outer peripheral surface of the inserted pipe _P0 and bite into it, and all the tooth portions 37A stably and excellently prevent the pipe from being pulled out. exert power.
Further, the pipe retainer ring 37 (see FIG. 4) according to the present invention has higher overall rigidity (as a material of the same plate thickness) than the retainer ring 58 shown in FIG. 9 (FIG. 8) of the conventional example. Since it is high and is less likely to be distorted, it can smoothly move in the axial direction and the radial direction within the rectangular storage space 8 to perform an automatic centering function, and all the tooth portions 37A can be adjusted over 360°. However, it can bite in evenly and can exhibit an excellent pipe pull-out prevention force.
There is a risk that the retainer ring 58 shown in FIGS. 8 and 9 showing a conventional example may be incorporated into the cap 62 in a deformed posture under strain and in a radially displaced state. The axial center of the incoming pipe P and the axial center of the retainer ring 58 are not aligned (not centered), and only a part of all the teeth 58A over 360° bites into the outer peripheral surface of the pipe P. There was a risk that the pipe withdrawal prevention force would be insufficient.
In the present invention, such conventional problems can be solved, the automatic centering function can be exhibited, and a large and stable pipe pull-out preventing force can be exhibited. Moreover, there is an advantage that compactness in the radial direction can also be achieved (clear by comparing FIG. 4 with FIG. 9).

Further, according to the present invention, the opening end portion 2A of the second main body 2 is provided with a pressure receiving fixing ring body 39 having an inwardly expanding tapered surface portion 39A; It has an outer reduced diameter tapered surface portion 38A that slidably abuts, a plurality of pipe biting claw portions 38C formed on the inner peripheral surface, and an axial center orthogonal surface 38E at the inner end in the axial direction, A C-shaped ring 38 having a cut 38B at one place on the circumference is provided inside the second main body 2; 38E and 38E are placed in face-to-face contact with each other; when the pipe pull-out force K _P acts, the pull-out preventing force is Since it is constructed so as to exert a large pipe pull-out preventing force by working together. Moreover, as is clear from FIG. 1, the internal storage space can be extremely small. In particular, since the retainer ring 37 is incorporated in the second main body 2 with the axis-perpendicular surface plate portion 37D of the retainer ring 37 and the axis-perpendicular surface 38E of the C-shaped ring 38 in face-to-face contact, the retainer ring The radial inward and outward movement of 37 and the radial inward and outward movement of C-ring 38, respectively, are unimpeded and smooth. Therefore, each of the retaining ring 37 and the C-shaped ring 38 exerts its own pipe pull-out preventing force, and can exert a large overall pipe pull-out preventing force.

Further, in the present invention, a pipe retainer ring 58 is provided inside the second body ₂ of the joint body 5; 58A includes an inner circumferential annular inclined surface plate portion 58B formed at equal intervals in the circumferential direction; A pressure receiving fixing ring body 39 having an inwardly expanding tapered surface portion 39A is attached to the opening end portion 2A of the second main body 2; It has an outer diameter-reduced tapered surface portion 38A that movably abuts, a plurality of pipe-biting claw portions 38C formed on the inner peripheral surface, and an axial-center orthogonal surface 38E at the inner end in the axial direction. A C-shaped ring 38 having a cut 38B at one circumferential location is provided inside the second main body 2; When the pipe pull-out force K _P acts, the pull-out preventing force is exerted by the combined action of the pull-out prevention ring 58 and the C-shaped ring 38. Since it is configured to do so, the retaining ring 58 can be automatically centered in a minute dimension in the radial direction, and the tooth portion 58A can stably and evenly bite in over 360° of the outer peripheral surface of the pipe, which is excellent. It can demonstrate the ability to prevent pipe pull-out. Moreover, the retainer ring 58 and the C-shaped ring 38 move radially inwardly and radially outwardly in minute dimensions, respectively, and exert sufficient force to prevent the pipe from being pulled out without interfering with each other.

REFERENCE SIGNS LIST 1 first main body 2 second main body 2A open end 5 joint main body
10 Annular groove
11 Inner insertion tube
14 Annular protrusion
15 Tapered male thread
21 Proximal barrel
21A Most proximal site
31 Retaining mechanism
37 Pipe retainer ring
37A Tooth
37B Inclined face plate
37C Outer edge
37D Axis orthogonal face plate
37E Reinforcing cylindrical face plate
38 C-shaped ring
38A Outer reduced diameter tapered surface
38B cut
38C Claw for biting pipe
38E plane perpendicular to the axis
39 Pressure receiving fixing ring body
39A Inwardly expanding tapered surface
50 Assembled channel hole
58 Retaining ring
58A Tooth
58B Annular inclined surface plate portion
58C outer edge
58D Axial orthogonal face plate part D _P inner diameter dimension D _50min minimum inner diameter dimension K ₃₇ Axial direction K _P pipe pull-out force L ₁ axis center L ₂ axis center P ₀ pipe

Claims (7)

A pipe joint structure in which a joint body (5) comprises a metal first body (1) and a short tubular plastic second body (2) into which a pipe to be connected (P ₀ ) is inserted and held. In
The first main body (1) has an inner cylindrical portion (11) that is inserted into the proximal end cylindrical portion (21) of the second main body (2) via a retaining mechanism (31),
An annular protruding portion (14) protrudes in the radial direction from the base end position of the inner insertion tube portion (11) of the first main body (1), an annular recessed groove (10) into which the most proximal portion (21A) of the proximal cylindrical portion (21) is inserted is formed in the annular projecting portion (14) as an opening in the axial direction;
Characterized pipe joint structure. The most proximal portion (21A) is press-fitted into the annular groove (10) from the axial direction so that the second body ( ₁ ) is aligned with the axis (L1) of the first body (1). 2) The pipe joint structure according to claim 1, wherein the shaft center (L ₂ ) of 2) is configured to prevent run-out. The first metal body (1) has a tapered external thread (15), and the annular protuberance (14) is for screwing the external thread (15) into a female thread of another member. 3. The pipe joint structure according to claim 1 or 2, having a hexagonal outer peripheral surface to be gripped by a working tool that applies rotational torque. The minimum inner diameter dimension (D _50min ) of the assembly passage hole (50) in the pipe connection completed state where the pipe (P ₀ ) is inserted into the joint body (5) is equal to the inner diameter dimension (D _P ) of the pipe (P ₀ ). 4. The pipe joint structure according to claim 1, 2 or 3, which is set substantially equal to . A pipe retaining ring (37) is provided inside the second body (2) of the joint body (5),
The retainer ring (37) is
an inner circular inclined surface plate portion (37B) in which a large number of tooth portions (37A) that engage with the outer peripheral surface of the pipe (P ₀ ) are formed at equal intervals in the circumferential direction;
an annular center-perpendicular face plate portion (37D) connected to the outer peripheral edge (37C) of the inclined face plate portion (37B);
It is connected to the outer peripheral edge of the axially orthogonal face plate portion ( _37D ), is bent in the same axial direction (K37) as the inclined face plate portion (37B), and is attached to the inner peripheral surface of the second main body (2). an opposing reinforcing cylindrical face plate portion (37E);
5. The pipe joint structure according to claim 1, 2, 3 or 4, comprising: A pressure-receiving fixing ring body (39) having an inwardly expanding tapered surface portion (39A) is attached to the opening end portion (2A) of the second main body (2),
An outer tapered surface portion (38A) with a reduced diameter that slidably contacts the tapered surface portion (39A) of the pressure receiving fixing ring body (39); 38C) and a plane perpendicular to the axis (38E) at the inner end in the axial direction, and a C-shaped ring (38) having a cut (38B) at one place on the circumference is placed inside the second body (2). provided,
disposing the plate portion (37D) of the retainer ring (37) orthogonal to the axis and the orthogonal surface (38E) of the C-shaped ring (38) in face-to-face contact,
6. The structure according to claim 5, wherein when the pipe pull-out force (K _P ) acts, the pull-out preventing force of the pipe pull-out is exerted by the cooperation of the pull-out prevention ring (37) and the C-shaped ring (38). Pipe joint structure. A pipe retaining ring (58) is provided inside the second body (2) of the joint body (5),
The retainer ring (58) is
An annular inclined surface plate portion (58B) on the inner peripheral side in which a large number of tooth portions (58A) that are engaged with the outer peripheral surface of the pipe (P ₀ ) are formed at equal intervals in the circumferential direction;
an annular axially orthogonal face plate portion (58D) connected to the outer peripheral edge (58C) of the inclined face plate portion (58B);
consists of
A pressure-receiving fixing ring body (39) having an inwardly expanding tapered surface portion (39A) is attached to the opening end portion (2A) of the second main body (2),
An outer tapered surface portion (38A) with a reduced diameter that slidably contacts the tapered surface portion (39A) of the pressure receiving fixing ring body (39); 38C) and a plane perpendicular to the axis (38E) at the inner end in the axial direction, and a C-shaped ring (38) having a cut (38B) at one place on the circumference is placed inside the second body (2). provided,
The plate portion (58D) of the retainer ring (58) perpendicular to the axis and the perpendicular surface (38E) of the C-shaped ring (38) are placed in face-to-face contact with each other,
2. The structure according to claim 1, wherein when a pipe pull-out force (K _P ) acts, the pull-out prevention force is exerted by the cooperation of the pull-out prevention ring (58) and the C-shaped ring (38). Pipe joint structure.

Images