JP2021092237A - Double pipe joint - Google Patents

Abstract

To provide a double pipe joint capable of preventing damage of an actual pipe joint and a protective pipe joint, and capable of fixing and holding the actual pipe joint in the protective pipe joint appropriately.SOLUTION: A double pipe joint 10 comprises an actual pipe joint 12, a protective pipe joint 14 that houses the actual pipe joint 12, and a spacer 16 that fixes and holds the actual pipe joint 12 in the protective pipe joint 14 so that a space is formed between the outer peripheral surface of the actual pipe joint 12 and the inner peripheral surface of the protective pipe joint 14. The spacer 16 is made of an elastic material.SELECTED DRAWING: Figure 2

Description

The present invention relates to a double pipe joint, and more particularly to a double pipe joint in which a real pipe joint is fixed and held in a protective pipe joint by a spacer.

An example of a conventional double pipe joint is disclosed in Patent Document 1. The double pipe joint (structure of the elbow portion of the double pipe) of Patent Document 1 includes an elbow pipe, an elbow sheath pipe into which the elbow pipe can be inserted and removed and stored, and two spacers. A protruding edge is formed on the inner wall of the straight portion of the elbow sheath tube, and each spacer fits the inner wall of the straight portion of the elbow sheath tube so that the peripheral end surface is slidable, and the peripheral end portion abuts on the protruding edge. Further, a through hole is formed in the central portion of the spacer, and both ends of the actual elbow tube are fitted into the through hole, so that the actual elbow tube is stored and fixed in the elbow sheath tube.

Japanese Unexamined Patent Publication No. 2001-200980

When the double pipe joint is buried in the soil, the protective pipe joint may be deformed by the earth pressure. In addition, when the double pipe joint is made of synthetic resin, there is a temperature difference between the actual pipe joint and the protective pipe joint due to the influence of the outside air temperature and the fluid temperature inside the actual pipe joint, and there is a large difference in the amount of thermal expansion and contraction. It may come out. Furthermore, external forces such as water pressure fluctuations, water hammer pressure, and seismic motion in the actual pipe joint may be applied to the double pipe joint. Since the stress generated by these is concentrated at the contact point between the actual pipe joint and the protective pipe joint and the spacer, there is a possibility that the actual pipe joint and the protective pipe joint may be damaged at this contact point.

Therefore, the main object of the present invention is to provide a novel double fitting.

Another object of the present invention is to provide a double pipe joint capable of preventing damage to the actual pipe joint and the protective pipe joint and appropriately fixing and holding the actual pipe joint within the protective pipe joint.

The first invention is a double pipe joint including a real pipe joint and a protective pipe joint for accommodating the actual pipe joint, which is provided on each of the outer peripheral surfaces of the ends of the actual pipe joint. It is characterized in that a spacer for fixing and holding the actual pipe joint in the protective pipe joint is formed of an elastic material so that a space is formed between the outer peripheral surface and the inner peripheral surface of the protective pipe joint. , Double pipe joint.

In the first invention, the double fitting includes a real fitting, a protective fitting and a spacer. Spacers are provided on each of the outer peripheral surfaces of the ends of the actual pipe joint to protect the actual pipe joint so that a space is formed between the outer peripheral surface of the actual pipe joint and the inner peripheral surface of the protective pipe joint. Hold fixed in the fitting. The spacer is then formed of an elastic material containing rubber such as EPDM and CR, a foam of synthetic resin, and a thermoplastic elastomer.

According to the first invention, since the spacer is formed of an elastic material, when a stress is generated in the double pipe joint, the spacer is elastically deformed to relieve the generated stress, thereby forming a real pipe joint and a protective pipe joint. It is possible to prevent damage at the contact point with the spacer. Therefore, the actual pipe joint can be appropriately fixed and held in the protective pipe joint.

The second invention is subordinate to the first invention, and the protective pipe joint has a protective pipe joint main body and a protective pipe widening socket formed at each end of the protective pipe joint main body. Further, each of the spacers has a tubular spacer body arranged between the outer peripheral surface of the end portion of the actual pipe joint and the inner peripheral surface of the end portion of the protective pipe joint body. This spacer body has an inner diameter smaller than the outer diameter of the end of the actual pipe joint before the spacer is mounted in the double pipe joint, and the spacer is mounted in the double pipe joint. In the state after being made, the inner peripheral surface of the spacer body is compressed by the outer peripheral surface of the end portion of the actual pipe joint.

According to the second invention, since the actual pipe joint is held in a state where the inner peripheral surface of the spacer body is compressed, the actual pipe joint can be firmly fixed and held by the spacer.

The third invention is dependent on the second invention, and the spacer has a tubular first extending portion extending from the outer peripheral portion of the spacer main body to the opening side of the protective tube expansion receiving port. The first extending portion sandwiches a corner portion formed on the inner peripheral surface of the inner portion of the protective tube expansion receiving port together with the spacer body.

According to the third invention, since the corner portion of the protective pipe joint is sandwiched between the first extension portion and the spacer main body, the spacer can be easily settled in a predetermined position in the protective pipe joint, and the spacer is on the inner side of the protective pipe joint main body. It can be prevented from being drawn into.

The fourth invention is dependent on the third invention, in which the spacer extends radially inward from the first extending portion and is integrated with the inner peripheral portion of the spacer body. Has.

The fifth invention is dependent on any one of the second to fourth inventions, and the spacer has a tubular third extending portion extending from the inner peripheral portion of the spacer body to the inner side of the protective pipe joint. .. This third extension has an inner diameter of the same size as the inner diameter of the spacer body, and the inner peripheral surface of the third extension is in a state after the spacer is mounted in the double pipe joint. Is compressed by the outer peripheral surface of the end of the actual pipe joint.

According to the fifth invention, it is possible to reinforce the fixing holding force of the actual pipe joint by the spacer while suppressing the axial length of the spacer main body and reducing the required amount of material.

The sixth invention is subordinate to any one of the second to fifth inventions, and the spacer body is the inner diameter of the end portion of the protective pipe joint body in the state before the spacer is mounted in the double pipe joint. It has a smaller outer diameter or an outer diameter of approximately the same size, and in the state after the spacer is mounted in the double pipe joint, the outer peripheral surface of the spacer body is the inner circumference of the end of the protective pipe joint body. It is compressed by the face.

According to the sixth invention, the actual pipe joint can be firmly fixed and held by the spacer, and the spacer can be prevented from being compressed more than necessary from the inner surface of the end portion of the protective pipe joint. Therefore, a double pipe joint is manufactured. At that time, the spacer can be firmly fixed and held at a predetermined position in the protective pipe joint while reducing the fitting load of the spacer.

The seventh invention is dependent on any one of the second to sixth inventions, and an annular groove extending in the circumferential direction is formed on at least one of the inner peripheral surface or the outer peripheral surface of the spacer body.

According to the seventh invention, the mounting resistance of the spacer can be reduced, and the holding force can be improved by the check valve effect.

The eighth invention is dependent on the fourth invention, and the second extending portion has an inner diameter smaller than the inner diameter of the spacer body. That is, the inner peripheral portion of the second extending portion protrudes radially inward from the inner peripheral surface of the spacer body.

According to the eighth invention, when the end portion of the actual pipe joint is fitted into the spacer, it is possible to prevent the end portion of the actual pipe joint from penetrating from the spacer. In addition, it is possible to prevent the adhesive from accumulating on the end face of the actual pipe joint.

According to the present invention, since the spacer is made of an elastic material, when a stress is generated in the double pipe joint, the spacer is elastically deformed to relieve the generated stress, thereby forming the actual pipe joint, the protective pipe joint and the spacer. It is possible to prevent damage at the contact point. Therefore, the actual pipe joint can be appropriately fixed and held in the protective pipe joint.

The above-mentioned object, other object, feature and advantage of the present invention will become more apparent from the detailed description of the examples described below with reference to the drawings.

It is sectional drawing which shows the double pipe line formed by using the double pipe joint which is one Example of this invention. It is sectional drawing which shows the double pipe joint of FIG. It is sectional drawing which shows the actual pipe joint provided with the double pipe joint of FIG. It is sectional drawing which shows the protection pipe joint provided with the double pipe joint of FIG. It is sectional drawing which shows the spacer provided in the double pipe joint of FIG. It is a side view which shows the spacer of FIG. FIG. 5 is an enlarged cross-sectional view showing an enlarged portion of a spacer mounting portion in the double pipe joint of FIG. It is sectional drawing which shows the double pipe joint which is another Example of this invention. It is sectional drawing which shows another example of a spacer. It is sectional drawing which shows still another example of a spacer. It is sectional drawing which shows still another example of a spacer.

With reference to FIG. 1, the double pipe joint 10 according to an embodiment of the present invention is a pipe joint for forming a double pipe line 100, and is a pipe joint in which actual pipe members 102 are connected to each other. An actual pipe joint 12 forming a part of the inner pipe) and a protective pipe joint 14 connecting the protective pipe members 104 to each other to form a part of the protective pipe (outer pipe) are provided. Further, as will be described in detail later, in the double pipe joint 10, the actual pipe joint 12 is fixedly held at a predetermined position in the protective pipe joint 14 by the spacer 16.

In the double pipe line 100 piped using the double pipe joint 10, even if a leak occurs in the actual pipe, the protective pipe prevents the internal fluid from directly flowing out to the outside. Further, since the actual tube is protected from an external impact by the protective tube, damage to the actual tube is prevented. Further, the protective pipe including the protective pipe joint 14 is preferably formed of a transparent material, and by making the protective pipe transparent, liquid leakage from the actual pipe can be visually detected.

The application of the double pipe line 100 to which the double pipe joint 10 is applied is not particularly limited, and can be applied to both non-pressure applications and pressure applications such as drainage lines, water supply lines, chemical liquid lines and cooling water lines. However, the double pipe joint 10 is particularly preferably used for a double pipe 100 for pressureless applications such as drainage and ventilation. Further, the nominal diameter (inner diameter) of the double pipe line 100 to which the double pipe joint 10 is applied is not particularly limited as long as it is a combination having a size capable of accommodating the actual pipe joint 12 in the protective pipe joint 14. The double pipe joint 10 is particularly preferably used for the double pipe line 100 in which the nominal diameter of the actual pipe is 40 to 100 mm and the nominal diameter of the protective pipe is 75 to 200 mm. Further, the material of the double pipe line 100 including the actual pipe joint 12 and the protective pipe joint 14 is not particularly limited, and is made of hard polyvinyl chloride, synthetic resins such as polyethylene, polypropylene and fluororesin, and metals such as iron. It can be selected as appropriate.

Hereinafter, the configuration of the double pipe joint 10 will be specifically described. However, in this embodiment, the double pipe line 100 to which the double pipe joint 10 is applied is for drainage, and the actual pipe member 102 to be connected is a rigid polyvinyl chloride pipe having a nominal diameter of 75 mm, and is a protective pipe member. The case where 104 is a rigid polyvinyl chloride pipe having a nominal diameter of 150 mm will be described.

As shown in FIGS. 1 and 2, the double pipe joint 10 is a 90 ° elbow type pipe joint, and includes a real pipe joint 12, a protective pipe joint 14 that houses the actual pipe joint 12 inside, and a real pipe. It is provided with two spacers 16 for fixing and holding the joint 12 in the protective pipe joint 14.

As shown in FIG. 3, the actual pipe joint 12 is a pipe joint for connecting the actual pipe members 102 to each other, and constitutes an actual pipe for flowing drainage to the inside together with the actual pipe member 102. In this embodiment, as the actual pipe joint 12, a 90 ° elbow type general-purpose DV joint (pressureless joint made of rigid polyvinyl chloride) having a nominal diameter of 75 mm is used. The actual pipe joint 12 has a curved tubular joint body (actual pipe joint body) 20 that is curved at an angle of 90 ° and a diameter-expanded socket (actual pipe diameter-expanded socket) formed at both ends of the joint body 20. ) 22.

As shown in FIG. 4, the protective pipe joint 14 is a pipe joint for connecting the protective pipe members 104 to each other, and constitutes a protective pipe that protects the actual pipe together with the protective pipe member 104. In this embodiment, as the protective pipe joint 14, a 90 ° elbow type general-purpose VUDV joint (thin-wall type pressureless joint made of rigid polyvinyl chloride) having a nominal diameter of 150 mm is used. Specifically, the protective pipe joint 14 has a curved tubular joint body (protective pipe joint body) 30 that is curved at an angle of 90 ° and an enlarged diameter socket (protection) formed at both ends of the joint body 30. It is provided with a pipe expansion socket) 32. The diameter-expanded socket 32 is formed by expanding the diameter from the end of the joint body 30 in a stepped manner, and is inside the inner portion of the diameter-expanded socket 32 (that is, the connecting portion between the joint body 30 and the diameter-expanded socket 32). A corner portion 38 including an inner peripheral surface 34 at the end of the joint body 30 and a stepped surface 36 is formed on the peripheral surface. Further, the inner peripheral surface of the enlarged diameter receiving port 32 is a tapered surface whose diameter gradually decreases toward the inner side.

Returning to FIGS. 1 and 2, spacers 16 are provided on the outer peripheral surfaces of the ends of the actual pipe joint 12, and a space is provided between the outer peripheral surface of the actual pipe joint 12 and the inner peripheral surface of the protective pipe joint 14. Is a member that fixes and holds the actual pipe joint 12 in the protective pipe joint 14 so that The specific configuration of the spacer 16 will be described later.

When the actual pipe joint 12, the protective pipe joint 14 and the spacer 16 are assembled to manufacture the double pipe joint 10, the actual pipe joint 12 is housed in the protective pipe joint 14 and the outer periphery of the end of the actual pipe joint 12 is accommodated. A spacer 16 is fitted between the surface and the inner peripheral surface of the protective pipe joint 14, and the actual pipe joint 12 is fixedly held at a predetermined position in the protective pipe joint 14 by the spacer 16. At this time, the actual pipe joint 12 with the spacer 16 attached to one end side is housed in the protective pipe joint 14, so that the actual pipe joint 12 is temporarily fixed by the one spacer 16 and then temporarily fixed. The other spacer 16 may be attached to the other end side of the actual pipe joint 12. However, after temporarily fixing the actual pipe joint 12 at a predetermined position in the protective pipe joint 14 using a temporary fixing jig, the spacer 16 may be attached to one end side and the other end side of the actual pipe joint 12. it can.

When the actual pipe joint 12 is fixedly held at a predetermined position in the protective pipe joint 14 by the spacer 16, then, between the outer peripheral surface of the end of the actual pipe joint 12 and the inner peripheral surface of the spacer 16, and the outer peripheral surface of the spacer 16. The adhesive is injected between the protective pipe joint 14 and the inner peripheral surface so that the adhesive spreads over the entire contact portion. When this adhesive solidifies, the production of the double pipe joint 10 is completed.

In such a double pipe joint, when stress is generated in the double pipe joint due to thermal expansion and contraction, earth pressure, etc., the generated stress is concentrated at the contact point between the actual pipe joint and the protective pipe joint and the spacer. Therefore, there is a risk that the actual pipe joint and the protective pipe joint will be damaged at this contact point.

Therefore, in this embodiment, the spacer 16 is formed of an elastic material. As a result, even if a thermal expansion / contraction force, earth pressure, or the like acts on the double pipe joint 10, the spacer 16 elastically deforms to relax the generated stress. Therefore, the actual pipe joint 12, the protective pipe joint 14, and the spacer 16 It is possible to prevent damage at the contact point.

As the elastic material forming the spacer 16, rubber such as EPDM (ethylene propylene diene rubber), CR (chloroprene rubber) and fluororubber, a foam of synthetic resin such as vinyl chloride resin, and a thermoplastic elastomer can be used. it can. As the foam, it is preferable to use a foam having a foaming ratio of 1.2 to 10.0 times so as to exhibit appropriate elasticity and strength.

The hardness of the spacer 16 is preferably set to 30 or more and 90 or less, and more preferably 50 or more and 90 or less in terms of shore A hardness. As a result, the strength that allows the actual pipe joint 12 to be appropriately fixed and held in the protective pipe joint 14 and the elasticity (flexibility) that can appropriately relieve the generated stress can be exhibited.

The spacer 16 of this example is formed by EPDM and has a shore A hardness of 60. As the adhesive for assembling the double pipe joint 10, it is preferable to use an adhesive for rubber such as acrylic type, cyanoacrete type, synthetic rubber type and chloroprene rubber type.

Further, as can be seen from FIG. 2, in this embodiment, in a state where the actual pipe joint 12 is housed in the protective pipe joint 14, the end surface of the actual pipe joint 12 (open end of the enlarged diameter receiving port 22) and the protective pipe joint The stepped surface 36 formed at the back of the enlarged diameter receiving port 32 of 14 is in a flush or substantially flush state. Therefore, in this embodiment, the actual pipe joint 12 can be appropriately fixed and held in the double pipe joint 10 in which the end surface of the actual pipe joint 12 and the stepped surface 36 of the protective pipe joint 14 are flush with each other or substantially flush with each other. , The spacer 16 having the following configuration is adopted. That is, the spacer 16 is particularly preferably used in the double pipe joint 10 in which the end surface of the actual pipe joint 12 and the stepped surface 36 of the protective pipe joint 14 are flush with each other or substantially flush with each other. Approximately flush means the range in which the position of the end face of the actual pipe joint 12 is within ± 5 mm with respect to the stepped surface 36 in the axial direction of the enlarged diameter receiving port 22 (that is, the axial distance between the surfaces is 5 mm or less). Suppose to say. However, the spacer 16 can also be used for the double pipe joint 10 in which the end surface of the actual pipe joint 12 and the stepped surface 36 of the protective pipe joint 14 are not flush with each other or substantially flush with each other. Hereinafter, the configuration of the spacer 16 will be specifically described.

With reference to FIGS. 5 to 7 together with FIGS. 2 to 4, the spacer 16 is a tubular member formed of an elastic material. The spacer 16 has a tubular spacer body 50. The spacer main body 50 is a main portion for fixing and holding the actual pipe joint 12, and is the outer peripheral surface of the end of the actual pipe joint 12 (specifically, the outer peripheral surface of the end of the enlarged diameter receiving port 22) and the protective pipe joint 14. It is arranged between the end inner peripheral surface 34 of the joint body 30. The axial length w1 of the spacer body 50 is, for example, 5 to 15 mm.

Further, the spacer 16 has a tubular first extending portion 52 extending from the outer peripheral portion of the spacer main body 50 to the opening side of the enlarged diameter receiving port 32 of the protective pipe joint 14. The axial length w2 of the first extending portion 52 is set to a dimension within a range that does not hinder the connection of the protective tube member 104 to the enlarged diameter receiving port 32, and is, for example, 2 to 5 mm. Further, the first extending portion 52 has an outer diameter d3 that is smaller than the inner diameter D3 of the inner portion of the enlarged diameter receiving port 32 of the protective pipe joint 14 or has substantially the same size as the inner diameter D3. That is, the outer diameter d3 of the first extending portion 52 is larger than the outer diameter d2 of the spacer main body 50, and the outer peripheral surfaces of the spacer main body 50 and the first extending portion 52 are arranged in a stepped shape. The back side surface of the first extending portion 52 comes into contact with the stepped surface 36 of the protective pipe joint 14, and the corner portion 38 of the protective pipe joint 14 is sandwiched together with the spacer main body 50.

Further, the spacer 16 has a tubular second extending portion 54 that extends radially inward from the first extending portion 52 and is integrated with the inner peripheral portion of the spacer main body 50. The axial length of the second extending portion 54 is set to be the same as the axial length w2 of the first extending portion 52, and is, for example, 2 to 5 mm. Further, the second extending portion 54 has an inner diameter of the same size as the inner diameter d1 of the spacer main body 50, and the inner peripheral surface of the spacer main body 50 and the inner peripheral surface of the second extending portion 54 are flush with each other. Is. The second extension portion 54 is arranged so as to project from the opening end of the diameter expansion socket 22 of the actual pipe joint 12 to the opening side of the diameter expansion socket 32 of the protective pipe joint 14, and is a second extension portion. The actual pipe joint 12 is not arranged on the inner peripheral surface side of the 54.

Furthermore, the spacer 16 has a tubular third extending portion 56 extending from the inner peripheral portion of the spacer main body 50 to the inner side of the protective pipe joint 14. The axial length w3 of the third extending portion 56 is, for example, 5 to 15 mm. However, the axial length w3 of the third extension portion 56 is within a range in which the spacers 16 provided at both ends of the actual pipe joint 12 do not collide with each other and do not interfere with the liquid leakage discharge function of the notch 58 described later. Set to dimensions. Further, the outer diameter d4 of the third extending portion 56 is smaller than the outer diameter d2 of the spacer main body 50, so that the outer peripheral surface of the third extending portion 56 does not come into contact with the inner peripheral surface of the protective pipe joint 14. There is. Further, the third extending portion 56 has an inner diameter of the same size as the inner diameter d1 of the spacer main body 50, and the inner peripheral surface of the spacer main body 50 and the inner peripheral surface of the third extending portion 56 are flush with each other. Is.

Therefore, the outer peripheral surface of the spacer 16 as a whole is formed in a three-step stepped shape, and the inner peripheral surface thereof is a smooth cylindrical surface.

Further, a plurality of notches 58 are formed on the outer peripheral portion of the spacer 16 so as to be arranged at predetermined intervals in the circumferential direction and penetrate the spacer main body 50 and the first extending portion 52 in the axial direction. In this embodiment, the spacer 16 has four notches 58 with a semicircular cross section arranged at 90 degree intervals. When the drainage flows out into the protective pipe due to the actual pipe being damaged in the double pipe 100, the notch 58 allows the leaked liquid to pass through the spacer 16 portion without staying, and is not shown. Used to lead to.

In such a spacer 16, the inner diameter d1 of the spacer main body 50 is set to a size that is, for example, 1.5 to 3.0 mm smaller than the outer diameter D1 of the end portion of the actual pipe joint 12, which is the mounting position thereof. That is, the spacer body 50 has an outer diameter D1 of the end portion (specifically, the end portion of the enlarged diameter receiving port 22) of the actual pipe joint 12 in a state before the spacer 16 is mounted in the double pipe joint 10. It has an inner diameter d1 smaller than that. Therefore, in the state after the spacer 16 is mounted in the double pipe joint 10, the inner peripheral surface of the spacer main body 50 is compressed by the outer peripheral surface of the end portion of the actual pipe joint 12. Further, the spacer 16 as a whole is pushed outward. By holding the actual pipe joint 12 in a state where the inner peripheral surface of the spacer main body 50 is compressed in this way, the actual pipe joint 12 can be firmly fixed and held by the spacer 16.

On the other hand, the outer diameter d2 of the spacer main body 50 is set to an outer diameter smaller than the inner diameter D2 of the end portion of the joint main body 30 of the protective pipe joint 14 at which the spacer main body 50 is mounted, or an outer diameter of substantially the same size. The size is set to be 0 to 2.0 mm smaller. That is, the spacer body 50 has an outer diameter d2 that is smaller than the inner diameter D2 of the end portion of the joint body 30 or substantially the same size as the inner diameter D2 in the state before the spacer 16 is mounted in the double pipe joint 10. have. Then, in the state after the spacer 16 is mounted in the double pipe joint 10, the spacer 16 is expanded outward by inserting the actual pipe joint 12 into the spacer 16, so that the spacer main body 50 The outer peripheral surface is compressed by the end inner peripheral surface 34 of the joint body 30. By pushing the spacer 16 outward in this way, the outer peripheral surface of the spacer body 50 is held by the protective pipe joint 14 in a compressed state, so that the actual pipe joint 12 is firmly fixed by the spacer 16. While holding the protective pipe joint 14, compression from the inner surface of the end portion of the protective pipe joint 14 can be prevented from being applied to the spacer 16 more than necessary. Therefore, when manufacturing the double pipe joint 10, the spacer 16 can be firmly fixed and held at a predetermined position in the protective pipe joint 14 while reducing the fitting load of the spacer 16.

Further, the third extending portion 56 has an inner diameter of the same size as the inner diameter d1 of the spacer main body 50 as described above. That is, the third extension portion 56 has an inner diameter smaller than the outer diameter D1 of the end portion of the actual pipe joint 12 in the state before the spacer 16 is mounted in the double pipe joint 10. Therefore, in the state after the spacer 16 is mounted in the double pipe joint 10, the inner peripheral surface of the third extension portion 56 is also compressed by the outer peripheral surface of the end portion of the actual pipe joint 12. By having the spacer 16 having such a third extending portion 56, the length w1 in the axial direction of the spacer body 50 is suppressed to reduce the amount of required material, and the fixed holding force of the actual pipe joint 12 by the spacer 16 is maintained. Can be reinforced.

Further, since the corner portion 38 of the protective pipe joint 14 is sandwiched between the first extending portion 52 and the spacer main body 50, the spacer 16 can be easily fitted in a predetermined position in the protective pipe joint 14, and the spacer 16 is the joint of the protective pipe joint 14. It is possible to prevent it from being pulled into the back side of the main body 30.

Furthermore, the second extension portion 54 has an inner diameter of the same size as the inner diameter d1 of the spacer main body 50, and the actual pipe joint 12 is not arranged on the inner peripheral surface side of the second extension portion 54. .. Therefore, in the state after the spacer 16 is mounted in the double pipe joint 10, the inner peripheral surface of the second extending portion 54 is slightly inclined inward in the radial direction to receive the expanded diameter of the actual pipe joint 12. The open end of the mouth 22 is locked. Therefore, the movement of the actual pipe joint 12 toward the opening side of the enlarged diameter receiving port 32 of the protective pipe joint 14 is regulated by the second extending portion 54.

As described above, according to this embodiment, since the spacer 16 is made of an elastic material, it is possible to prevent damage at the contact points between the actual pipe joint 12 and the protective pipe joint 14 and the spacer 16, and the spacer 16 can be prevented from being damaged in the protective pipe joint 14. The actual pipe joint 12 can be appropriately fixed and held.

Further, according to this embodiment, since the spacer 16 holds the actual pipe joint 12 in a state where the inner peripheral surface of the spacer main body 50 is compressed, the actual pipe joint 12 can be firmly fixed and held. Further, since the spacer 16 is held by the protective pipe joint 14 in a state where the outer peripheral surface of the spacer main body 50 is compressed, the spacer 16 is firmly fixed and held at a predetermined position in the protective pipe joint 14.

Further, since the spacer 16 holds the actual pipe joint 12 in a state of being compressed from the inner peripheral surface side and the outer peripheral surface side, the strength of the spacer 16 is improved and the actual pipe joint 12 is fixed in the axial direction of the spacer 16. The holding force (resistance force to the axial movement of the actual pipe joint 12) is also improved. Therefore, the spacer 16 can appropriately withstand the weight of the actual pipe joint 12 and the load of the drainage flowing in the actual pipe joint 12. Further, when the actual pipe member 102 is connected to the actual pipe joint 12, it is possible to prevent the actual pipe joint 12 from being pushed into the inner side of the joint body 30 of the protective pipe joint 14 by the insertion force of the actual pipe member 102.

In the above-described embodiment, the 90 ° elbow type double pipe joint 10 is illustrated, but as shown in FIG. 8, the double pipe joint 10 may be a 90 ° Y cheese type pipe joint. Absent. In this case, the double pipe joint 10 is provided with spacers 16 on each of the outer peripheral surfaces of the three ends of the actual pipe joint 12. Further, although not shown, the double pipe joint 10 may be a pipe joint of a socket type, a 45 ° elbow type, a 45 ° Y cheese type, or the like.

Further, as shown in FIG. 9, a tapered surface 60 having a diameter larger toward the opening edge can be formed on the inner peripheral surface of the second extending portion 54 of the spacer 16. By having such a tapered surface 60, even if excess adhesive drips around the spacer 16 when assembling the double pipe joint 10, the adhesive can be easily wiped off.

Further, as shown in FIG. 10, one or a plurality of annular grooves 62 extending in the circumferential direction may be formed on the inner peripheral surface and the outer peripheral surface of the spacer body 50 of the spacer 16. The annular groove 62 may be formed only on either the inner peripheral surface or the outer peripheral surface of the spacer main body 50. In this embodiment, a plurality of annular grooves 62 extending in the circumferential direction and lining up in the axial direction are formed on the inner peripheral surface and the outer peripheral surface of the spacer body 50, respectively, and the inner peripheral surface and the outer peripheral surface of the spacer body 50 are saw blades. It is formed in a wavy shape (or wavy shape). Further, in this embodiment, the annular groove 62 is also formed on the inner peripheral surfaces of the second extending portion 54 and the third extending portion 56. The protruding cross-sectional shape formed between the annular groove 62 and the annular groove 62 is not limited to a triangular shape, and can be appropriately changed, and may be a semicircular shape, a rectangular shape, a trapezoidal shape, or the like.

By forming the annular groove 62 on at least one of the inner peripheral surface or the outer peripheral surface of the spacer main body 50 as in the embodiment shown in FIG. 10, the mounting resistance of the spacer 16 is reduced, and the holding force is improved by the check valve effect. it can.

Furthermore, as shown in FIG. 11, the inner diameter d5 of the second extending portion 54 is set smaller than the inner diameter d1 of the spacer main body 50, and the inner peripheral portion of the second extending portion 54 is the inner peripheral surface of the spacer main body 50. It can also be formed so as to protrude inward in the radial direction. However, the size of the inner diameter d5 of the second extension portion 54 is such that the inner peripheral surface of the second extension portion 54 is the actual pipe joint 12 in the state after the spacer 16 is mounted in the double pipe joint 10. The size is set within a range that does not protrude significantly inward in the radial direction from the inner peripheral surface of the end. In this embodiment, the inner diameter d5 of the second extension portion 54 is set to substantially the same size as the inner diameter of the end portion of the actual pipe joint 12.

By setting the inner diameter d5 of the second extending portion 54 to be smaller than the inner diameter d1 of the spacer main body 50 as in the embodiment shown in FIG. 11, when the end portion of the actual pipe joint 12 is fitted into the spacer 16. It is possible to prevent the end portion of the actual pipe joint 12 from penetrating through the spacer 16. In addition, it is possible to prevent the adhesive from accumulating on the end face of the actual pipe joint 12.

Further, in the above embodiment, the inner diameter d1 of the spacer main body 50 is set to a size smaller than the outer diameter D1 of the end portion of the actual pipe joint 12, and the outer diameter d2 is set to the inner diameter D2 of the end portion of the joint main body 30. The inner diameter d1 of the spacer body 50 is set to be larger than or substantially the same size as the outer diameter D1 of the end of the actual pipe joint 12, and the outer diameter d2 is set to be smaller or substantially the same size. It can also be set to a size smaller than the inner diameter D2 of the end portion of the main body 30. This also makes it possible to exert the same compression-fixing effect as in the above-described embodiment.

Further, the spacer 16 is formed of at least an elastic material, and its shape and arrangement position can be appropriately changed as long as the actual pipe joint 12 can be fixedly held at a predetermined position in the protective pipe joint 14. For example, in the above-described embodiment, the third extending portion 56 is formed to have a rectangular cross section, but the shape of the third extending portion 56 can be appropriately changed and may be formed to have a triangular cross section or the like. Further, the spacer 16 may have at least the spacer body 50, and the first extension portion 52, the second extension portion 54, and the third extension portion 56 do not necessarily have to be formed.

Further, in the above-described embodiment, the double pipe joint 10 is illustrated, but in the double pipe provided with the actual pipe and the protective pipe for accommodating the actual pipe inside, the spacer for fixing and holding the actual pipe in the protective pipe is elastic. It can also be formed by a material. Even in such a double pipe, by forming the spacer with an elastic material, the same action and effect as that of the double pipe joint 10 can be obtained, and damage at the contact point between the actual pipe and the protective pipe joint and the spacer can be prevented. The actual pipe can be properly fixed and held in the protective pipe. As the material of the spacer used for the double tube, a low-foaming synthetic resin having a relatively high rigidity, for example, a hard polyvinyl chloride resin having a foaming ratio of about 2 times is preferable.

The specific numerical values such as the dimensions mentioned above are merely examples, and can be changed as appropriate according to the needs of the product specifications and the like.

10 ... Double pipe joint 12 ... Actual pipe joint 14 ... Protective pipe joint 16 ... Spacer 20 ... Actual pipe joint joint body 22 ... Actual pipe joint diameter expansion socket 30 ... Protective pipe joint joint body (Protective pipe joint body) )
32 ... Enlarged diameter socket for actual pipe joints (Protective pipe enlarged diameter socket)
38 ... Corner 50 ... Spacer body 52 ... 1st extension 54 ... 2nd extension 56 ... 3rd extension 58 ... Notch

Claims (8)

In a double pipe joint including a real pipe joint and a protective pipe joint for accommodating the actual pipe joint inside.
The actual pipe joint is protected so as to be provided on each of the outer peripheral surfaces of the ends of the actual pipe joint so that a space is formed between the outer peripheral surface of the actual pipe joint and the inner peripheral surface of the protective pipe joint. A double fitting, characterized in that the spacers that are fixed and held in the fitting are made of an elastic material. The protective pipe joint has a protective pipe joint main body and a protective pipe diameter expansion socket formed at each end of the protective pipe joint main body.
Each of the spacers has a tubular spacer body arranged between the outer peripheral surface of the end of the actual pipe joint and the inner peripheral surface of the end of the protective pipe joint body.
The spacer body has an inner diameter smaller than the outer diameter of the end portion of the actual pipe joint before the spacer is mounted in the double pipe joint, and the spacer is inside the double pipe joint. The double pipe joint according to claim 1, wherein the inner peripheral surface of the spacer body is compressed by the end outer peripheral surface of the actual pipe joint in the state after being mounted. The spacer has a tubular first extending portion that extends from the outer peripheral portion of the spacer body to the opening side of the protective tube expansion receiving port.
The double pipe joint according to claim 2, wherein the first extending portion sandwiches a corner portion formed on the inner peripheral surface of the inner portion of the protective tube expansion receiving port together with the spacer body. The double pipe according to claim 3, wherein the spacer extends inward in the radial direction from the first extending portion and has a tubular second extending portion that is integrated with an inner peripheral portion of the spacer body. Fittings. The spacer has a tubular third extending portion that extends from the inner peripheral portion of the spacer body to the inner side of the protective pipe joint.
The third extension has an inner diameter of the same size as the inner diameter of the spacer body, and the inner peripheral surface of the third extension is in a state after the spacer is mounted in the double pipe joint. The double pipe joint according to any one of claims 2 to 4, wherein is compressed by the outer peripheral surface of the end portion of the actual pipe joint. The spacer body has an outer diameter smaller than the inner diameter of the end portion of the protective pipe joint body or an outer diameter of substantially the same size before the spacer is mounted in the double pipe joint. The method according to any one of claims 2 to 5, wherein the outer peripheral surface of the spacer body is compressed by the inner peripheral surface of the end of the protective pipe joint body in a state after the spacer is mounted in the double pipe joint. Double pipe fitting. The double pipe joint according to any one of claims 2 to 6, wherein an annular groove extending in the circumferential direction is formed on at least one of the inner peripheral surface and the outer peripheral surface of the spacer body. The double pipe joint according to claim 4, wherein the second extending portion has an inner diameter smaller than the inner diameter of the spacer body.

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