Pipe fittings

Abstract

To provide a novel pipe joint capable of preventing the entry of liquid to a pipe end face.SOLUTION: The pipe joint includes a cylindrical cap into which the end of a pipe is inserted, a sleeve arranged in the pipe, and a joint body of which the outer peripheral face is fitted and fixed to the cap, the sleeve having a cylindrical insertion part extending along the inner peripheral face of the pipe, and a contact part which is provided protruding from the outer peripheral face of the insertion part to the inner peripheral face of the pipe and of which the front end contacts the inner peripheral face of the pipe.SELECTED DRAWING: Figure 4

Description

Technical Field

[0006] ,

[0007] , ,

[0001] The present disclosure relates to a pipe joint.

Background Art

[0002] Conventionally, pipe joints for connecting a plurality of pipes have been known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the pipe joint of Patent Document 1, an inner sleeve is disposed inside the pipes to be connected. Patent Document 1 discloses a structure of a pipe joint that seals between an O-ring (sealing member in Patent Document 1) and the outer peripheral surface of a pipe. In the structure of the pipe joint of Patent Document 1, there is a gap between the inner circumference of the pipe and the inner sleeve. Therefore, the liquid flowing inside the pipe penetrates up to the outer peripheral surface of the pipe.

[0005] In recent years, some pipes forming the pipes have a heat insulating layer on the pipe wall. The heat insulating layer may include a foam or the like. When the sealing structure of Patent Document 1 is used for such a pipe, there is a risk that the liquid may penetrate into the heat insulating layer.

[0006] An object of the present disclosure is to provide a novel pipe joint that can prevent liquid from penetrating into the pipe end face.

Means for Solving the Problems

[0007] A pipe joint according to one aspect of the present disclosure comprises a cylindrical cap into which the end of a pipe is inserted, a sleeve disposed inside the pipe, and a joint body whose outer surface is fitted and fixed with the cap. The sleeve has a cylindrical insertion portion extending along the inner surface of the pipe, and an annular contact portion that protrudes from the outer surface of the insertion portion toward the inner surface of the pipe, with its tip in contact with the inner surface of the pipe.

[0008] With this pipe fitting, the sleeve, positioned inside the pipe, has its contact tip in contact with the inner surface of the pipe. As a result, at least one point on the inner surface of the pipe is in continuous contact with the sleeve's contact point along its entire circumference. Therefore, the inner surface of the pipe can be sealed without increasing the size of the sleeve. Consequently, liquid intrusion into the end face of the pipe can be prevented. [Effects of the Invention]

[0009] According to this disclosure, a novel pipe fitting can be provided that can prevent liquid from entering the end face of a pipe. [Brief explanation of the drawing]

[0010] [Figure 1] Front view of a pipe joint in an embodiment of this disclosure. [Figure 2] An exploded perspective view of a pipe joint in an embodiment of the present disclosure. [Figure 3] Enlarged view of Figure 2. [Figure 4] Cross-sectional view of Figure 1A-A. [Figure 5] Cross-sectional view of a pipe joint in another embodiment of the present disclosure. [Modes for carrying out the invention]

[0011] Embodiments of this disclosure will be described below with reference to the drawings. In this specification, the direction along the central axis O of the pipe joint will be referred to as the axial direction, the direction intersecting the central axis O in a plan view from the axial direction will be referred to as the radial direction, and the direction that circles around the central axis O in a plan view will be referred to as the circumferential direction. The arrows shown in Figures 1, 2, and 4 indicate an example of the flow direction of the liquid flowing inside the pipe 10.

[0012] As shown in Figures 1 and 2, the pipe fitting 1 comprises a fitting body 2, two caps 4, two inner sleeves (an example of a sleeve) 6, and two inner cores (an example of an elastic member) 8. The pipe fitting 1 of this embodiment is a component for connecting pipes 10 used for drains of air conditioning equipment installed in buildings. In this embodiment, a straight-type pipe fitting 1 that connects pipes 10 in a straight line will be described as an example. However, the pipe fitting 1 may also be an elbow type that connects pipes 10 in a bent state, or other types of pipe fittings.

[0013] In this embodiment, the explanation will be based on an example in which liquid flows inside the pipe 10 in the direction of the arrow in Figure 2. Therefore, the cap 4, inner sleeve 6, and inner core 8 located on the near side of Figure 2 are the cap 4, inner sleeve 6, and inner core 8 on the liquid inlet side. Conversely, the cap 4, inner sleeve 6, and inner core 8 located on the far side of Figure 2 are the cap 4, inner sleeve 6, and inner core 8 on the liquid outlet side. In the following specification, "inlet side" refers to a component located upstream in the direction of liquid flow, and "outlet side" refers to a component located downstream in the direction of liquid flow.

[0014] Furthermore, as shown in Figure 4, the pipe 10 in this embodiment is a pipe with an insulating layer 10b in the pipe wall 10a. In this embodiment, the pipe wall 10a is formed by sandwiching the insulating layer 10b between two resin layers 10c. The insulating layer 10b contains a foam such as foamed polyvinyl chloride. The resin layers 10c contain rigid polyvinyl chloride or foamed polyvinyl chloride.

[0015] As shown in Figures 2 and 3, the joint body 2 is a cylindrical member with two caps 4 fitted to its outer circumference. As shown in Figures 3 and 4, the joint body 2 has two outer circumferential walls 2a, two inner circumferential walls 2b, a bottom wall 2c connecting the outer circumferential walls 2a and the inner circumferential walls 2b, and four screw grooves 2d. The joint body 2 forms two receiving recesses 2e in the space enclosed by the outer circumferential walls 2a, the inner circumferential walls 2b, and the bottom wall 2c, which accommodate the inner wall 4b of the cap 4 (described later), the inner sleeve 6, the inner core 8, and the end of the pipe 10. The receiving recesses 2e are formed on the inlet side and the outlet side of the joint body 2, respectively.

[0016] As shown in Figures 2 and 3, the outer circumferential wall 2a is formed in a cylindrical shape, and screw grooves 2d are formed on the outer circumferential surface of the outer circumferential wall 2a. In this embodiment, two screw grooves 2d are formed on the outer circumferential surface on the inlet side, and two are formed on the outer circumferential surface on the outlet side. The screw grooves 2d are portions on the outer circumferential surface that are recessed radially toward the central axis O.

[0017] Two screw grooves 2d are formed in the outer peripheral wall 2a on the inlet side, and are formed in a clockwise spiral shape along the circumferential direction from the inlet end to the outlet end of the outer peripheral wall 2a. As shown in Figure 3, a lock groove 2f is provided at the outlet end of the screw groove 2d. When the cap 4 is rotated clockwise, the screw grooves 2d slide while guiding the claws 4e provided on the outer wall 4a. As a result, the cap 4 moves from the inlet side to the outlet side while rotating in the axial direction. When the claws 4e engage with the lock groove 2f, the cap 4 is locked and fixed.

[0018] The two screw grooves 2d formed in the outer peripheral wall 2a on the outlet side are formed in a clockwise spiral shape from the end on the outlet side of the outer peripheral wall 2a toward the inlet side. Similar to the inlet side, a lock groove 2f is provided at the inlet side end of the screw groove 2d on the outlet side. When the cap 4 is rotated clockwise, the screw groove 2d slides while guiding the claw 4e provided on the outer wall 4a. As a result, the cap 4 moves from the outlet side toward the inlet side while rotating in the axial direction. When the claw 4e engages with the lock groove 2f, the cap 4 is locked and fixed.

[0019] In this embodiment, one screw groove 2d is formed over an approximately 90-degree section when viewed from the axial inlet side. That is, when the cap 4 is rotated clockwise by approximately one-quarter turn, the cap 4 is locked. Note that the number and the provided section of the screw grooves 2d can be changed in various ways.

[0020] As shown in FIG. 4, the inner peripheral wall 2b is arranged radially inside the outer peripheral wall 2a and is formed in a cylindrical shape. The bottom wall 2c extends radially from the end on the outlet side of the outer peripheral wall 2a and connects to the end on the outlet side of the inner peripheral wall 2b at the inlet side of the joint body 2. The bottom wall 2c extends radially from the end on the inlet side of the outer peripheral wall 2a and connects to the end on the inlet side of the inner peripheral wall 2b at the outlet side of the joint body 2. In this embodiment, the bottom wall 2c on the inlet side and the bottom wall 2c on the outlet side are integrally formed.

[0021] As shown in FIGS. 1 and 2, the cap 4 is formed in a cylindrical shape and the end of the pipe 10 is inserted into the joint body 2. As shown in FIG. 4, the cap 4 has an outer wall 4a, an inner wall 4b, a top wall 4c, a guide wall 4d, and a claw 4e. One cap 4 is fitted and fixed to the joint body 2 at each of the inlet side and the outlet side of the pipe joint 1. In this embodiment, the cap 4 on the inlet side will be described. The description of the cap 4 on the outlet side is omitted because it has the same structure as the cap 4 on the inlet side.

[0022] The outer wall 4a is formed in a cylindrical shape and is located at the outermost radial end of the cap 4. The inner wall 4b is formed in a cylindrical shape and is located radially inward of the outer wall 4a. The top wall 4c extends radially from the inlet end of the outer wall 4a and connects to the inner wall 4b. The guide wall 4d is provided on the inlet side of the top wall 4c, and its inner circumferential surface extends axially. When the pipe 10 is inserted into the cap 4, the inner circumferential surface of the guide wall 4d contacts the outer circumferential surface of the pipe 10, guiding the pipe 10 into the receiving recess 2e.

[0023] As shown in Figure 2, the claw 4e is a portion that protrudes radially inward from near the outlet end of the outer wall 4a (the inlet end in the case of the outlet cap 4 in Figure 2) of the outer wall 4a. As described above, when the cap 4 rotates clockwise, the claw 4e is guided by the screw groove 2d to the lock groove 2f and engages with the lock groove 2f. This locks the cap 4 and the joint body 2. In this way, the cap 4 moves along the axial direction while rotating between an unlocked position in which the cap 4 can rotate and a locked position in which the claw 4e is locked in the lock groove 2f.

[0024] As shown in Figure 3, in this embodiment, the fitting body 2 has a first confirmation hole 2g on the outlet side of the screw groove 2d. Also, as shown in the outlet-side cap 4 in Figure 2, it has a protrusion 4g that protrudes from the inlet-side end of the inner wall 4b. Although not shown in Figure 2, the inlet-side cap 4 also has a protrusion 4g that protrudes from the outlet-side end of the inner wall 4b, similar to the outlet-side cap 4. The protrusion 4g corresponds to the position of the first confirmation hole 2g when the cap 4 is in the locked position. In other words, the fitting body 2 moves between a locked position in which the cap 4 is fixed relative to the fitting body 2 and a rotatable unlocked position, and has a first confirmation hole 2g that allows the protrusion 4g of the cap 4 to be confirmed when the cap 4 is fixed in the locked position. This allows the user of the pipe fitting 1 to visually confirm whether the cap 4 has rotated to the locked position. As a result, the user can confirm that the pipe 10 is securely connected to the pipe fitting 1.

[0025] Furthermore, the cap 4 has a second confirmation hole 4f in its top wall 4c. The second confirmation hole 4f is positioned at the same location as the claw 4e when viewed axially from the inlet side. The fitting body 2 also has an anti-loosening groove 2h at the inlet end of the screw groove 2d. The anti-loosening groove 2h consists of two ribs that bulge radially beyond the screw groove 2d. When the claw 4e of the cap 4 is in the initial rotation position in the unlocked state, it catches on this anti-loosening groove 2h. That is, the user of the pipe fitting 1 can see the claw 4e engaged with the anti-loosening groove 2h through the second confirmation hole 4f. This allows the user to visually confirm that the pipe fitting 1 is in the unlocked position and that the pipe 10 can be inserted into the cap 4.

[0026] As shown in Figure 4, the outer circumferential wall 2a of the joint body 2 is inserted into the space between the outer wall 4a and the inner wall 4b of the cap 4. The inner circumferential surface of the inner wall 4b is provided with a tapered portion 4h, the inner diameter of which decreases as it moves toward the tip side of the inlet of the cap 4. The tapered portion 4h is in contact with the outer circumferential surface of the first cylindrical portion 8a of the inner core 8, which will be described later. That is, the inner diameter of the contact point between the outer circumferential surface of the inner core 8 and the inner circumferential surface of the inner wall 4b of the cap 4 decreases as it moves toward the tip side of the inlet of the first cylindrical portion 8a.

[0027] In this embodiment, the joint body 2 and the cap 4 are formed, for example, by injection molding using a synthetic resin material. However, the joint body 2 may be formed from a metal material. In this case, the joint body 2 can be formed by casting, forging, or machining.

[0028] As shown in Figures 3 and 4, the inner sleeve 6 is positioned inside the pipe 10. As shown in an enlarged view in Figure 4, the inner sleeve 6 has an insertion portion 6a, a contact portion 6b, an enlarged diameter portion 6c, and a surface portion 6d. The insertion portion 6a is a cylindrical portion that extends along the inner circumferential surface of the pipe 10. The contact portion 6b is a rib portion that protrudes from the outer circumferential surface of the insertion portion 6a toward the inner circumferential surface of the pipe 10, with its tip contacting the inner circumferential surface of the pipe 10. The outer diameter of the contact portion 6b is set to be larger than the inner diameter of the pipe 10. This ensures that the contact portion 6b makes secure contact with the inner circumferential surface of the pipe 10.

[0029] The contact portion 6b is an annular rib provided around the entire circumference of the insertion portion 6a. Therefore, the tip of the contact portion 6b contacts the inner surface of the pipe 10 over its entire circumference. This seals the inner surface of the pipe 10 with the tip of the contact portion 6b. As a result, the liquid flowing inside the pipe 10 does not pass over the outer circumference of the insertion portion 6a and reach the enlarged diameter portion 6c. Furthermore, such a contact portion 6b only needs to be provided thinly on the outer circumference of the insertion portion 6a, and there is no need to significantly reduce the inner diameter of the insertion portion 6a. In addition, multiple contact portions 6b are provided on the outer surface of the insertion portion 6a. This allows the inner surface of the pipe 10 and the contact portions 6b to contact at multiple points, improving the sealing performance. As a result, the sealing performance can be further improved without reducing the inner diameter of the insertion portion 6a. Note that if the entire outer surface of the insertion portion 6a and the inner surface of the pipe 10 are in contact, the insertability of the pipe 10 will be poor. Therefore, by providing a contact portion 6b, the pipe joint 1 of this embodiment can achieve both sealing performance and ease of insertion while suppressing the reduction of the inner diameter of the inner sleeve 6.

[0030] As shown in an enlarged view on the left side of Figure 4, the enlarged diameter portion 6c is located at the exit end of the insertion portion 6a and is a portion with an inner diameter larger than that of the insertion portion 6a. The surface portion 6d expands radially outward from the insertion portion 6a and is the portion that connects the end of the insertion portion 6a and the enlarged diameter portion 6c. When the pipe 10 is inserted into the cap 4, the exit end surface of the pipe 10 is positioned in contact with the first surface 6e, which is the inlet side (cap 4 side) surface of the surface portion 6d. In other words, the pipe 10 is inserted until it abuts against the first surface 6e. Also, the second surface 6f, which is the surface of the surface portion 6d opposite to the first surface 6e, is in contact with the tip of the inner circumferential wall 2b. By inserting the pipe 6 until the second surface 6f and the tip of the inner circumferential wall 2b come into contact (butt together), the inner sleeve 6 makes straight contact with the inner circumferential wall 2b. This makes it less likely for a step to occur between the inner surface of the insertion portion 6a of the inner sleeve 6 and the inner surface of the inner wall 2b. In this embodiment, the inner sleeve 6 is made of a thermoplastic plastic such as low-density polyethylene. However, the inner sleeve 6 may be made of other soft or semi-rigid resins.

[0031] The inner core 8 is formed in a cylindrical shape. In this embodiment, the inner core 8 is made of an elastic material such as rubber. The inner core 8 has a first cylindrical portion 8a, a second cylindrical portion 8b, a connecting portion (an example of a bottom portion) 8c, and a third cylindrical portion 8e extending from the connecting portion 8c. The first cylindrical portion 8a is formed in a cylindrical shape and is positioned between the inner circumferential surface of the cap 4 and the outer circumferential surface of the pipe 10. The outer circumference of the first cylindrical portion 8a is provided with an outer tapered portion (an example of a tapered portion) 8f such that the outer diameter decreases towards the tip on the inlet side. The second cylindrical portion 8b is formed in a cylindrical shape and is positioned between the inner circumferential surface of the enlarged diameter portion 6c of the inner sleeve 6 and the outer circumferential surface of the inner circumferential wall 2b of the joint body 2. The first cylindrical portion 8a includes at least one annular groove portion 8d provided on its inner circumferential surface. The second cylindrical portion 8b includes at least one annular groove portion 8g provided on its outer circumferential surface. The inner circumferential surface of the enlarged diameter portion 6c of the inner sleeve 6 contacts and seals with the groove portion 8g provided on the outer circumferential surface of the second cylindrical portion 8b.

[0032] Next, the procedure for connecting the pipe 10 and the pipe fitting 1 will be described. In this embodiment, the procedure for connecting the pipe 10 to the inlet pipe fitting 1 will be described by the user handling the pipe fitting 1. The procedure for the outlet side is the same as the inlet side, so the explanation will be omitted.

[0033] First, the inner end face of the pipe 10 is chamfered. Then, the pipe 10 is inserted from the guide wall 4d of the cap 4, and while the contact portion 6b of the inner sleeve 6 is in contact with the inner surface of the pipe 10, it is inserted until the end face of the pipe 10 abuts against the first surface 6e. At this time, the pipe 10 is in contact with the inner surface of the inner core 8. In this embodiment, since the inner core 8 has a groove 8d in the first cylindrical portion 8a, the frictional resistance between the pipe 10 and the inner core 8 can be reduced, making insertion easier.

[0034] Next, rotate the cap 4 clockwise. At this time, the tapered portion 4h of the cap 4 and the outer tapered portion 8f of the inner core 8 come into contact, and the tapered portion 4h of the cap 4 compresses the inner core 8. When the inner core 8 is compressed, it presses against the outer surface of the pipe 10. This makes it difficult for the pipe 10 to come out of the pipe fitting 1.

[0035] Furthermore, because the tapered portion 4h of the cap 4 presses the outer tapered portion 8f of the inner core 8 toward the outlet side, the end face of the pipe 10 can maintain contact with the first surface 6e. In addition, because the surface portion 6d is pressed against the end face of the pipe 10, even if a load is generated on the inner sleeve 6 or inner core 8 toward the inlet side, for example, the second surface 6f can push back against the inner sleeve 6 and inner core 8.

[0036] When the cap 4 is rotated to the locked position, the cap 4 is fixed in a locked state with the fitting body 2. In this way, the pipe 10 and the pipe fitting 1 are connected.

[0037] As described above, the pipe joint 1 according to this disclosure provides a novel pipe joint 1 that can seal the inner surface of the pipe 10 with the inner sleeve 6 while suppressing the reduction in diameter of the pipe 10 caused by the inner sleeve 6. Furthermore, with the pipe joint 1 according to this disclosure, since the inner core 8 is pressed against the outer surface of the pipe 10, the pipe 10 is less likely to come loose from the pipe joint 1 even without using adhesive. In addition, since a seal is formed between the contact portion 6b of the inner sleeve 6 and the inner surface of the pipe 10, it is also possible to prevent liquid from entering the heat insulating layer 10b of the pipe 10.

[0038] Although embodiments of the present disclosure have been described above, the present disclosure is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention. In particular, the various modifications described herein can be combined as needed.

[0039] <Other Embodiments> For example, in the above embodiment, an example was described using a configuration in which an enlarged diameter portion 6c is provided and the end face of the pipe 10 abuts against the surface portion 6d, but this disclosure is not limited thereto. As shown in Figure 5, the pipe joint 201 in other embodiments may include a joint body 202, two caps 204, two inner sleeves (an example of a sleeve) 206, and two inner cores (an example of an elastic member) 208. The pipe joint 201 may also have a structure in which the pipe 210 is pressed directly against the inner core 208. Even with such a structure, a seal can be formed between the inner circumferential surface of the pipe 210 and the outer circumference of the contact portion 206b, so that liquid does not penetrate the heat insulating layer 210b. [Explanation of Symbols]

[0040] 1: Pipe fitting 2: Fitting body 4: Cap 4h: Tapered section 6: Inner sleeve (an example of a sleeve) 6a: Insertion part 6b: Contact part 6c: Expanded diameter part 6d: Surface part 6e: First surface 6f: 2nd side 8: Inner core (an example of an elastic member) 8a: First cylindrical section 8b: Second cylindrical section 10: Pipe

Claims

1. A cylindrical cap into which the end of the pipe is inserted, A sleeve disposed inside the aforementioned pipe, A joint body whose outer surface is fitted and fixed with the cap, A cylindrical elastic member is disposed inside the joint body, Equipped with, The aforementioned sleeve is A cylindrical insertion portion extending along the inner circumferential surface of the aforementioned pipe, It has an annular contact portion that protrudes from the outer circumferential surface of the insertion portion toward the inner circumferential surface of the pipe, and whose tip contacts the inner circumferential surface of the pipe, The elastic member is Having a first cylindrical portion positioned between the cap and the pipe, Pipe fittings.

2. The aforementioned sleeve is An enlarged diameter portion having a larger inner diameter than the aforementioned insertion portion, It expands radially outward, and has a surface portion that connects the end of the insertion portion and the expanded diameter portion, It has, The end face of the pipe contacts the first surface, which is the surface of the surface portion that is located on the cap side. The pipe fitting according to claim 1.

3. The elastic member is Furthermore, a second cylindrical portion is disposed between the joint body and the enlarged diameter portion of the sleeve, It has, The inner circumferential surface of the enlarged diameter portion of the sleeve contacts the outer circumferential surface of the second cylindrical portion. The pipe fitting according to claim 2.

4. The aforementioned cap is The elastic member has a tapered portion that contacts the outer circumferential surface of the first cylindrical portion, and the contact point with the outer circumferential surface of the first cylindrical portion of the elastic member has a tapered portion whose inner diameter decreases as it advances toward the tip of the first cylindrical portion. The pipe fitting according to claim 3.

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