JP5410469B2 - Pipe fitting - Google Patents

Description

  The present invention relates to a pipe joint.

The inventor has filed patent applications for a number of pipe joints in the past.
For example, as shown in FIGS. 14 to 17, the fitting main body 33 having the insertion cylinder portion 32 inserted into the end portion of the pipe 31 to be connected and the concave circumferential groove 34 of the insertion cylinder portion 32 are mounted. A sealing member 35, a tightening ring 36 with a slit for tightening the end of the pipe 31 fitted on the insertion tube 32 with a resilient tightening force F ₃₆ , and the tightening ring 36 The diameter of the tightening ring 36 is detachably held at the end of the slit so as to expand the diameter of the tightening ring 36 against the resilience of the pipe, and comes into contact with the tip of the pipe 31 to be inserted. A piece 37 and a retaining ring 38 whose inner peripheral surface is latched to the outer peripheral surface of the pipe 31 that is externally fitted to the insertion tube portion 32 in a retaining state, and the inner periphery of the retaining ring 38 On the side, there has been proposed a pipe joint provided with a plurality of tooth portions 39 that are cut at equal intervals in the circumferential direction (see Patent Document 1).

Japanese Patent No. 3411546

Incidentally, the conventional pipe joint shown in FIGS. 14 to 17 described above has the following problems. (i) The end of the pipe 31 is tightened with a resilient tightening force F ₃₆ (see FIG. 17) by the tightening ring 36 to prevent the pipe 31 from being pulled out in the direction of arrow G. Deterrence was insufficient. (ii) alone clamping force F ₃₆ of the clamping ring body 36 is pulled out deterrent is insufficient thus further required the retaining ring 38 missing. (iii) As can be seen from FIG. 14, the reaction force received by the retaining ring 38 from the pipe 31 is transmitted to the joint body 33 through the cap nut 40 and the transparent surrounding cylinder 41 and further through the screwing portion 42. Therefore, the cap nut 40, the enclosing cylinder 41, the screwed portion 42 and the like require a sufficient thickness in terms of strength, and also require an interconnection strength. (iv) The seal material 35 and the seal groove (concave groove) 34 are required, and without this seal material 35, external leakage of the fluid cannot be avoided. (v) Since the sealing material 35 and the seal groove (concave groove) 34 are required as described above, the thickness of the insertion tube portion 32 is increased, and the through hole (flow channel hole) 43 of the insertion tube portion 32 is increased. Becomes a small diameter and the fluid passage resistance increases.

In addition, if the elastic fastening force F ₃₆ of the fastening ring ₃₆ is sufficiently increased, the above problems (i), (ii), (iv), etc. should be solved. The increased tightening ring 36 is extremely difficult to manufacture, and further, in the tightening ring ₃₆ that generates such a strong and resilient elastic tightening force F ₃₆ , It has also been found that the sandwiched expanded diameter piece 37 cannot be pressed and released at the tip of the pipe 31. That is, the diameter-enlarged piece 37 is sandwiched with a large clamping force of several hundred kg, and the diameter-enlarged piece 37 is not detached by the insertion force of the pipe 31 itself.
The object of the present invention is to solve the above-mentioned many problems.

In view of this, the pipe joint according to the present invention elastically connects the joint main body having the insertion cylinder portion inserted into the end portion of the pipe to be connected and the end portion of the pipe externally fitted to the insertion cylinder portion. A pipe joint comprising: a tightening ring for tightening with a tightening force ; and a diameter expanding member sandwiched so as to expand the diameter of the tightening ring against the tightening force of the tightening ring In this case, the diameter-enlarging member is temporarily assembled so that the diameter-enlarged body is set to a strength that is damaged by the tightening force from the tightening ring, and the diameter-enlarged body is not damaged by the tightening force . A temporary reinforcing piece that detects a tip portion of the pipe inserted together and separates from the enlarged diameter main body, breaks the enlarged diameter main body, and disengages from the tightening ring, and the enlarged diameter main body includes: A single letter-shaped central collar, and two sandwiched legs projecting from one side of the central collar Two temporary reinforcing piece mounting protrusions projecting from the other side of the central flange, and the other side of the central flange is cut out from the interval between the two protrusions An inverted triangular cutout portion is formed, and a notch of the inverted triangle of the cutout portion constitutes a stress concentration generating notch for promoting damage, and the temporary reinforcing piece is a substantially rectangular shape having a substantially rectangular hole. In the frame type, when the pipe is not inserted, the projecting piece of the enlarged diameter main body is inserted into the hole, and when the pipe is not inserted, the tightening force is applied to the tightening ring. When the temporary reinforcement piece is applied to the two sandwiched leg portions by the above, the temporary reinforcing piece comes into contact with the inserted protruding piece portion with a deterrent force smaller than the tightening force, and from the notch. It is configured to prevent the occurrence of cracks, and when the insertion of the pipe is detected, the temporary reinforcing piece is When separated from, from the notch and cracks occur instantaneously, the crack is enlarged while modified as protruding portions of the two above isolates were constructed as described above expanded body may be damaged. In the present invention, “temporary” in the terms of “temporarily assembled” and “temporary reinforcing piece” means “temporary figure” until the connection state is switched to a full (final) connection state. It means that.

The tightening ring has a double structure of an inner layer clamp ring and an outer layer clamp ring.
Further, the slit of the inner layer clamp ring and the slit of the outer layer clamp ring were fitted to each other at different positions by 180 ° in the circumferential direction .

  According to the present invention, the above-mentioned conventional problems (i) to (v) can be solved. When the tightening ring 5 that generates a strong tightening force is used to prevent the pipe from being pulled out, the diameter-expanding member can be removed lightly (with a small force). In addition, the structure becomes simple, and it is often possible to omit the sealing groove and the sealing material in the insertion tube portion, and the diameter of the through hole (flow channel hole) of the insertion tube portion can be increased. The passage resistance can also be reduced.

It is principal part sectional drawing which shows one Embodiment of this invention. It is principal part sectional drawing which showed the pipe connection middle and the completion state. It is a principal part front view. It is a KK arrow enlarged view of FIG. It is schematic structure explanatory drawing. It is a principal part expansion explanatory drawing. It is a figure which shows an example of an enlarged diameter main body, Comprising: (A) is a front view, (B) is a side view. It is a figure which shows an example of a temporary reinforcement piece, Comprising: (A) is a front view, (B) is a side view. It is explanatory drawing which shows the structure and effect | action of a diameter-expansion member. It is explanatory drawing which shows the moment when the temporary reinforcement piece isolate | separated in the diameter expansion member. It is explanatory drawing of the moment when a diameter-expansion main body destroys. It is sectional drawing for description of the state which shows other embodiment and a temporary reinforcement piece isolate | separates. It is sectional drawing which shows the connection completion state in other embodiment. It is sectional drawing which shows a prior art example. It is a front view of the retaining ring used in the conventional example. It is a cross-sectional side view of the conventional retaining ring. It is principal part expansion explanatory drawing of a prior art example.

Hereinafter, the present invention will be described in detail based on the illustrated embodiment.
1 and 2, reference numeral 1 denotes a pipe to be connected, and an end portion 1A thereof is inserted into a pipe joint J according to the present invention as indicated by an arrow A. Reference numeral 2 denotes a joint body, which integrally includes an insertion tube portion 3 that is inserted into the inner peripheral surface of the end portion 1A of the pipe 1.

The pipe 1 can be made of various materials and structures as long as the inner peripheral surface is a synthetic resin, preferably a synthetic resin tube such as PEX (crosslinked polyethylene), PE (polyethylene), PB (polybutene), A composite tube having a metal layer such as Al as an intermediate layer is used. Further, a liquid such as water supply or hot water supply or a gas such as air, natural gas, or LPG flows through the pipe 1 and the pipe joint J.
Then, a tightening ring 5 for tightening the pipe end portion 1A externally fitted to the insertion tube portion 3 with a resilient tightening force (as shown in FIGS. 2, 3 and 4), and this tightening A diameter expanding member 6 is provided so as to be detachable so as to expand the diameter of the tightening ring 5 against the elastic force of the ring 5. As will be described later, the diameter-expanding member 6 is a small member obtained by temporarily assembling a plurality of (two) parts into a unit, and each of the plurality (two) parts performs a clever function and operation. The tip 1B of the pipe 1 inserted as shown in FIGS. 1 to 2A and 2B is detected and detached from the clamping ring 5.

  As shown in FIGS. 1 to 4, the tightening ring 5 has a double structure of a C-type inner layer clamp ring 51 and a C-type outer layer clamp ring 52, and FIG. 5B and FIG. 3, the slit 51A of the inner layer clamp ring 51 and the slit 52A of the outer layer clamp ring 52 are fitted (fitted) to each other at 180 ° positions in the circumferential direction. Thus, the tightening ring 5 is an inner-layer / outer-layer double structure and can also be referred to as a pipe tightening annular unit U.

The diameter-expanding member 6 is sandwiched between slits 51A of the inner layer clamp ring 51 of such a double-structured tightening ring 5 (tightening ring unit U). In FIG. 5, the double structure pipe tightening annular unit U (tightening ring 5) in which the inner layer clamp ring 51 and the outer layer clamp ring 52 are closely fitted to each other has a strong elastic force Fu, As shown in FIG. 2B, the pipe end 1A can be elastically tightened in the radial inward direction. Here, if the radial inward elastic forces of the inner layer clamp ring 51 and the outer layer clamp ring 52 are F ₁ and F ₂ , the strong elastic force Fu of the unit U (clamping ring 5) is , Fu = F ₁ + F ₂ .

Due to the strong elastic force Fu of the tightening ring 5 (pipe tightening ring unit U) having such a double-ballistic structure (under the condition that the diameter-expanding member 6 is detached as shown in FIG. 2B). Even if the end portion 1A of the pipe 1 is brought into pressure contact with the insertion tube portion 3 at a high surface pressure and the sealing material (and the seal groove) is omitted from the insertion tube portion 3, a sufficient sealing action can be obtained.
Further, connecting members such as pins, rivets, bolts, and bands for connecting the inner layer clamp ring 51 and the outer layer clamp ring 52 to each other are omitted.
As shown in FIG. 5A, the inner layer slit 51A and the outer layer slit 52A may be aligned in the same direction and assembled at the same position.

  Next, FIG. 6 is an enlarged view of the main part of FIG. 2. In FIG. 6, FIG. 1, and FIG. The seal groove (concave groove) 34 and the seal material 35 (not shown) are omitted, and a number of low triangular protrusions 8 are provided in an independent annular shape. In the direction of arrow E, the triangular protrusion 8 is bitten into the inner peripheral surface of the pipe end 1A by the tightening force on the pipe end 1A by the strong elastic force Fu shown in FIGS. This prevents the pipe from coming off and prevents the fluid from leaking outside. That is, the triangular protrusion 8 is bitten into the inner peripheral surface of the end portion of the pipe 1 by the strong elastic force Fu of the tightening ring body 5 (pipe tightening ring unit U) having a double structure, thereby preventing and sealing. Is welcoming you.

At a present invention, the triangular protrusion 8 is large number, defined as being 7 or more, also, the lower triangular protrusion 8, the height dimension H _8, is 0.1 mm to 0.3 mm It is defined as (In FIG. 1, FIG. 2 and FIG. 6, nine cases are shown.)
Further, a low round mountain-shaped sealing round ridge 9 is disposed at an intermediate position in the axial direction of a plurality of low triangular ridges 8 protruding from the outer peripheral surface of the insertion tube portion 3. The low round ridge-shaped sealing ridge 9 is defined as having a height dimension H ₉ of 0.1 mm to 0.3 mm. Thus, the height dimensions H ₈ and H ₉ of the triangular ridge 8 and the sealing round ridge 9 are set to be substantially equal, and are set sufficiently lower than the conventionally known bamboo-shaped triangular ridge.

Further, as shown in FIG. 6, the basic (interval) pitch P ₁ between the triangular ridges 8 and 8 is set to 2 mm or less. Further, with respect to this pitch P ₁ , The pitches P ₂ and P ₃ between the adjacent triangular protrusions 8A are set large. The latter pitches P ₂ and P ₃ may be the same, but a slight difference may be provided.

If, when the very large pulling force is applied instantaneously to the arrow E direction is a number of inner surfaces of the triangular protrusion 8 a exceeds the pipe 1 moves in the arrow E direction, with the movement of the fundamental pitch P ₁ It is assumed that the triangular protrusion 8 is again locked in the original triangular groove 13 and moves by the basic pitch P ₁ as indicated by arrows E ′ and E ′ in FIG.
At this time, the flat circumferential surface without the concave groove 13 moved as indicated by the arrow E ′ by one pitch is elastically deformed into a round concave shape corresponding to the round ridge 9 and is brought into a close contact state. Since the flat circumferential surface having no gap is elastically deformed into a round concave shape, no external leakage of fluid occurs and stable sealing performance is exhibited.
As shown in FIG. 6, the triangular protrusion 8 is preferably a right triangle having a side 18 that is orthogonal to the axial center on the inner side of the pipe joint.
In addition, the triangular protrusion 8 has a cross-sectional shape having a round shape or a round shape with a flat shape (not shown), and has a sealing function in addition to a locking function. Also good.

Next, the diameter expanding member 6 will be described. FIG. 3 is a view of the main part when viewed from the inside of the pipe joint, and FIG. 4 is an enlarged view taken along the line KK of FIG. 3, and FIGS. 3 and 4 and FIGS. Further, as shown in FIGS. 1 and 2, the diameter-expanding member 6 is configured by temporarily assembling a diameter-expanding main body 61 and a temporary reinforcing piece 62, and the diameter-expanding main body 61 is formed from the tightening ring 5. The hardness is set in advance so as to be damaged by the elastic force Fx received. In other words, when the temporary reinforcing piece 62 is not temporarily assembled, the damage (destruction)-refer to FIG. 11--is caused by the strong elastic force indicated by the arrow Fx shown in FIG.
Specifically, in the embodiment shown in FIGS. 3 and 4, the diameter-enlarged body 61 is sandwiched between the slits 51 </ b> A of the inner layer clamp ring 51. Reinforced to prevent destruction. At this time, the resilient force Fx is a resilient external force generated from both the inner layer clamp ring 51 and the outer layer clamp ring 52 of the double-structured tightening ring 5.

  The diameter-expanded main body 61 is made of steel such as S65C, SK material, or malleable cast iron having a hardness of HRC45 or higher, preferably HRC48-55. Moreover, a stress concentration generating notch N for promoting damage is formed in at least one place (so that damage occurs immediately when the temporary reinforcing piece 62 is detached).

  In FIG. 7, the enlarged diameter main body 61 is a block body having a uniform thickness. If it is described by being divided by a two-dot chain line, a single letter-shaped central collar 63 and one side of the central collar 63 will be described. Two clamped leg portions 64, 64 projecting from the (lower side), and two temporary reinforcing piece mounting projections 65, 65 projecting from the other side (upper side) of the central collar 63, In addition, an inverted triangular notch 67 is formed continuously from the interval 66 between the two projecting pieces 65, 65, and the upper side of the central collar 63 is formed in a notch shape. A notch N is formed (in a sharp shape) with an apex angle of an inverted triangle.

The pair of sandwiched leg portions 64 and 64 are arc-shaped projecting piece types so as to form a substantially semicircular inner peripheral surface having a predetermined radius R, and the outer peripheral arc-shaped surface 68 directly forms a slit of the inner layer clamp ring 51. It abuts on the opening end surface 69 forming 51A.
The temporary reinforcing piece 62 is formed of a plate piece having the same wall thickness and having a substantially rectangular hole 70, and the whole is a substantially rectangular frame shape, and is assembled to the fastening ring 5 as shown in FIG. It is formed on an arcuate side 71 that is flush with the outer peripheral surface of the clamp ring 52 or slightly inward in the radial direction. Further, as is apparent from FIG. 8A, the left and right sides 72, 72 of the penetrating hole 70 are expanded in parallel with each other to the line portion 72A and radially inward (downward in FIG. 8). And an inclined portion 72B. By doing so, as shown in FIGS. 1 to 2A and further as shown in FIG. 2B, the temporary reinforcing piece 62 is pressed against the tip 1B of the pipe 1 and gradually inclined. Then, the resistance force at the time of reduction is reduced, and the temporary reinforcing piece 62 is detached from the projecting piece portions 65 and 65 of the enlarged diameter main body 61 with a light force.

In FIG. 9, the projecting piece portions 65, 65 of the enlarged diameter main body 61 are inserted into the holes 70 of the temporary reinforcing piece 62, and the tightening force indicated by the arrows Fx, Fx is applied by the tightening ring 5. when, at sufficiently small deterrent F ₆₂ than the clamping force Fx, thereby preventing cracking from the notch N (refer to FIG. 1).

1 and 3 showing the pipe not inserted state, a part 62A of the temporary reinforcing piece 62 protrudes radially inward from the inner peripheral surface of the inner layer clamp ring 51, and the pipe 1 is in the direction of arrow A. When inserted, the tip 1B of the pipe 1 comes into contact with the part 62A. In other words, the temporary reinforcing piece 62 detects the tip portion 1B of the inserted pipe 1. Immediately as shown in (instantly) FIG. 2 (A), the temporary reinforcing piece 62 Yuki inclined, separated from the enlarged body 61, a state of FIG. 10, until now, by the arrow F ₆₂ in FIG. 9 As shown in the figure, the deterring force acting was zero, and a crack Y instantly occurred from the notch N at the stress concentration point, and a pair of projecting portions 65, 65 in the direction of arrows 73, 73 The crack Y expands as shown in FIG. 11 while being deformed so as to be isolated, and the enlarged diameter main body 61 is broken (broken), and a loud sound is generated. Along with this, each piece damaged (broken) at high speed as indicated by arrows 74 and 74 in FIG. 11 is detached from the fastening ring 5 while being scattered (see FIG. 2B). Inside the cover 12, a space portion 75 for accommodating the temporary reinforcing piece 62 and the enlarged diameter main body 61 detached in this manner is previously provided.

Incidentally, in FIG. 9, the reason why the deterring force F ₆₂ can be sufficiently small under the condition that the extremely large elastic force Fx acts on the leg portion 64 is as follows. That is, the large resistance force corresponding to the elastic force Fx is largely shared by the internal stress of the diameter-expanded main body 61 (the central casing 63) itself. For example, an external force of 10% to 30% is applied to the arrow _F62. This is because it may be applied by the temporary reinforcing piece 62 in the direction of.

In this way, the temporary reinforcing piece 62 can be separated from the protruding piece portions 65, 65 of the enlarged diameter main body 61 with a small force. In particular, the fastening ring 5 composed of the inner layer clamp ring 51 and the outer layer clamp ring 52 as a double structure can generate the strong resilience Fx that has been difficult in the past. Regardless of the elastic force Fx, in the present invention, the temporary reinforcing piece 62 is separated (detached) with a small force (as described above), and the diameter-expanded main body 61 is immediately destroyed, as shown in FIG. The tightening ring 5 tightens the pipe end 1A with a strong elastic force Fu so that the inner peripheral surface of the pipe 1 can be brought into close contact with the insertion tube portion 3 as shown in FIG.
Further, as can be seen from the state of FIG. 2, since the lever principle is used, the force to be applied from the pipe 1 to the part 62A of the temporary reinforcing piece 62 in the arrow A direction can be further reduced.

  Next, it is also preferable for the Al-plastic composite pipe or the like to form a sensing protrusion 76 as shown by a two-dot chain line in FIG. That is, if such a projecting piece 76 is formed on the diameter-expanding member 6, as shown in FIGS. 12 and 13, the insertion of the pipe 1—the insertion of the tip 1B—is quickly sensed. (Refer to FIG. 2 and FIG. 3 for comparison.) The pipe 1 particularly close to the tip 1B is clamped by the fastening ring 5 so that it can be prevented from coming off. Is.

1 to 3, the inner diameter of the inner layer clamp ring 51 is expanded to an inner diameter dimension slightly larger than the outer diameter of the pipe 1 when the pipe is not inserted in FIG. 1. As shown in FIG. 1, the pipe tightening annular unit U having a double structure produces the inner layer clamp ring 51 in a shape close to a true circle, and the outer layer clamp ring 52 has a strong elastic force F. it is desirable to set the width W ₅₂ as to exhibit ₂ to greater than the width W ₅₁ of the inner clamp ring 51. Furthermore, it is desirable to set larger than the thickness dimension T ₅₁ of the outer layer clamp ring 52 of the thickness dimension T ₅₂ the inner clamp ring 51.
The inner layer clamp ring 51 of the clamp ring 5 having a double structure is easy to plastically process a spring steel material or the like into a C shape (compared to a single thick one) and is an accurate round It is easy to form. On the other hand, the outer layer clamp ring 52 is also easy to be plastically processed into a C shape with spring steel or the like (compared to a single thick one), and the roundness is not so strict. This has the advantage that it can be manufactured easily and can be manufactured even if the width dimension W ₅₂ and the thickness dimension T ₅₂ are sufficiently increased.

Moreover, if the configuration of only the inner layer clamp ring 51 is considered, it is slightly in the axial direction (in the direction of the width dimension W ₅₁ ) (if the outer layer clamp ring 52 does not exist in FIGS. 3 and 4). It is deformed into a conical shape (tapered shape) by the presence of the diameter expanding member 6. In other words, the enlarged diameter member 6 is not the center of the axial direction (direction of the width dimension W _51), in order to unevenly distributed on the upper end side in FIG. 4, inner clamping ring 51 resiliently expanded is shown in FIG. 4 There is a possibility that the pipe 1 is deformed into a tapered shape with a slightly reduced diameter from the upper side to the lower side, and the smooth insertion of the pipe 1 may be hindered. However, as shown in FIG. 1, the outer layer clamp ring 52 to the left in FIG. 1 (a pipe joint in direction), an inner stretched shape beyond the enlarged diameter member 6, near the center of its width dimension W ₅₂ Since the diameter-expanding member 6 can be disposed, it is possible to prevent the inner diameter of the tightening ring 5 from becoming tapered (conical).

For example, when the outer diameter of the pipe 1 to which the pipe joint J according to the present invention is applied is set to 10 mm to 30 mm, the pinching pressure (elasticity) for holding the diameter expanding member 6 in FIG. 3 and FIG. (Force) Fx is extremely large, 200kg to 800kg. In particular, as shown in FIG. 6, in order to securely seal without the seal material, the triangular protrusion 8 and the sealing round protrusion 9 need to sufficiently bite into the inner peripheral surface of the pipe. Since the elastic force Fu (= F ₁ + F ₂ ) of the tightening ring 5 must be sufficiently increased, the clamping force (elastic force) Fx must be set to an extremely large value of 200 kg to 800 kg.

Therefore, with the tightening ring 36 made of a single material (spring steel strip) as shown in FIGS. 14 to 17 of the conventional example, the above-mentioned 200 kg to 800 kg which has been considered impossible at all in the past. This was achieved for the first time by using a double structure for the clamping pressure.
In other words, if a spring steel strip with a particularly large thickness is plastically deformed into a small-diameter cylindrical mold with an inner diameter of over 10 mm to over 30 mm, it will break down during manufacturing, and it will be processed into a perfect circle. In the past, it was considered impossible, and there was a problem that the resilience (clamping force) would change extremely with the change in diameter.

  In FIGS. 1 and 2, reference numeral 12 denotes a cover, which has a space 75 in which the detached fastening ring 5 is accommodated and is preferably made of a transparent resin. It can be confirmed whether or not the member 6 is detached. As is apparent from FIGS. 1 and 2, the retaining ring 38 illustrated in FIGS. 14 to 17 of the conventional example is completely omitted. Therefore, in FIG. 14 to FIG. 17, it is necessary for the cover (enclosure cylinder) 41 to handle a large axial force that the retaining ring 38 that bites into the outer peripheral surface of the pipe 31 receives from the pipe 31. The joint body 33 had to be firmly connected to the joint body 33 by the portion 42 or the like. On the other hand, in the present invention, almost no strength is required, and it is sufficient to simply connect the joint body 2 to the joint body 2, and the cover 12 itself may be made of a thin resin.

The present invention is not limited to the illustrated embodiment, and can be freely changed. For example, by sufficiently extending the length of the projecting piece portions 65, 65, the elastic force acting on the leg portions 64, 64 can be used. You may make it respond | correspond to the case where force Fx is large. In addition, the shape of the diameter-expanded main body 61 can be deformed, and if the temporary reinforcing piece 62 is separated, the shape and the structure may be such that the elastic force Fx is received and instantaneously broken (damaged). Further, the temporary reinforcing piece 62 may be a C-shape, a U-shape, or the like in addition to the square annular body surrounded by the periphery.
Further, the present invention is not limited to the male screw adapter type illustrated in FIGS. 1 and 2, and can be freely applied to various types of pipe joints such as a female screw adapter, a socket, and cheese.

  In the present invention, as described above, the tightening ring 5 has a double structure of the inner layer clamp ring 51 and the outer layer clamp ring 52. After being processed into a cylindrical shape (for example, inner diameter 10 mm to 30 mm), it can be fitted into a double structure by fitting so as to form an inner layer and an outer layer. The pipe 1 is tightened with a force to withstand a large pull-out force, and the sealing material for the insertion tube portion 3 can be omitted. Then, the conventional retaining ring 38 (see FIGS. 14 to 17) can be omitted, and the configuration of the pipe joint is simplified. Further, the cover 12 can be made thin and does not require strength, and the connection strength to the joint body 2 can be weak.

  Further, since the sealing material and the seal groove are omitted from the insertion tube portion 3, the thickness of the insertion tube portion 3 can be reduced, and accordingly, the through-hole of the insertion tube portion 3 can be formed sufficiently large, and the fluid passage An increase in resistance can be prevented.

  As described above, the present invention includes the joint body 2 having the insertion cylinder portion 3 inserted into the end portion 1A of the pipe 1 to be connected, and the end of the pipe 1 externally fitted to the insertion cylinder portion 3. A tightening ring 5 for tightening the portion 1A with a resilient tightening force, and an expansion pinched so as to expand the diameter of the tightening ring 5 against the resilient force of the tightening ring 5 In the pipe joint comprising the diameter member 6, the diameter-expanding member 6 includes a diameter-expanding main body 61 set to a strength that is damaged by the elastic force from the fastening ring 5, The enlarged diameter main body 61 is temporarily assembled so as not to be damaged by the elastic force, and the tip 1B of the pipe 1 inserted therein is detected and separated from the enlarged diameter main body 61 to damage the enlarged diameter main body 61. Since the temporary reinforcing piece 62 to be detached from the tightening ring 5 is provided, the temporary reinforcing piece 62 is pressed slightly by the pipe tip 1B. Can be separated by the insertion work of the pipe 1 can be easily and quickly. Since the force for expanding the diameter of the tightening ring 5 can be extremely increased, the tightening ring 5 is subjected to the double generation of the strong elastic force Fu of the inner layer clamp ring 51 and the outer layer clamp ring 52. It was possible to have a structure.

DESCRIPTION OF SYMBOLS 1 Pipe 1A End part 1B Tip part 3 Insertion cylinder part 5 Fastening ring 6 Diameter expansion member
51 Inner layer clamp ring
52 Outer clamp ring
51A, 52A slit
61 Expanded body
62 Temporary reinforcement piece N Notch

Claims (3)

A joint body (2) having an insertion cylinder part (3) inserted into the end part (1A) of the pipe (1) to be connected, and the pipe (1) externally fitted to the insertion cylinder part (3) end the clamping ring body for tightening by (1A) of the resiliently clamping force (Fx) (5), with該締against該締with annulus clamping force of (5) (Fx) In a pipe joint comprising a diameter-enlarging member (6) sandwiched so as to expand the diameter of the ring (5),
The diameter-expanding member (6) includes a diameter-expanding body (61) set to a strength that is damaged by the tightening force (Fx) from the tightening ring (5), and the diameter-expanding body (61) The tip (1B) of the pipe (1) that is temporarily assembled and inserted so as not to be damaged by the tightening force (Fx) is detected and separated from the diameter-enlarging body (61), and the diameter-enlarging body (61 ) And a temporary reinforcing piece (62) for detaching from the tightening ring (5) ,
The diameter-enlarging main body (61) includes a single-letter central collar (63), two sandwiched legs (64) (64) projecting from one side of the central collar (63), and the center Two temporary reinforcing piece mounting projections (65) (65) projecting from the other side of the flange (63), and the two projections (65) (65) The other side of the central flange (63) is cut out from the gap (66) to form an inverted triangular cutout (67), and the top angle of the inverted triangle of the cutout (67) is used to promote breakage. A stress concentration generation notch (N) for
The temporary reinforcing piece (62) has a substantially rectangular frame shape having a substantially rectangular hole (70). When the pipe is not inserted, the temporary reinforcing piece (62) is inserted into the hole (70). The protruding piece (65) (65) is inserted,
When the tightening force (Fx) is applied to the two sandwiched leg portions (64) (64) by the tightening ring (5) in a state where the pipe is not inserted, the temporary reinforcing piece (62 ) is, the protruding piece that is plugged against (65) (65), in contact with the clamping force (Fx) smaller deterrent than (F _62), crack from the notch (N) Configured to prevent
And, when the insertion of the pipe (1) is detected and the temporary reinforcing piece (62) is separated from the enlarged diameter main body (61), a crack (Y) is instantaneously generated from the notch (N), The two protruding pieces (65) and (65) are deformed so as to be isolated from each other, and the crack (Y) expands to damage the diameter-expanded main body (61). Pipe fittings.   The pipe joint according to claim 1, wherein the tightening ring (5) has a double structure of an inner layer clamp ring (51) and an outer layer clamp ring (52). The slit (51A) of the inner layer clamp ring (51) and the slit (52A) of the outer layer clamp ring (52) are fitted to each other at 180 ° positions in the circumferential direction. Pipe fittings.

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