In-core for piping components

Abstract

To provide an in-core which can high-dimensionally make easy insertion into a piping member and prevention of scrape-out of the piping member at the insertion compatible.SOLUTION: A piping joint 1 comprises a first flow passage member 2 having an outer cylinder 6, a second flow passage member 3 having an inner cylinder 12 inserted into the outer cylinder 6, and snap-engaged therewith, and an in-core 4 which is inserted in and arranged at the inner cylinder 12, and intensifies the snap engagement. A plurality of recesses extending in a peripheral direction is formed at an end part located at an insertion side of the in-core 4 at an internal peripheral face of the inner cylinder 12, and temporary holding parts 23 are provided between the respective recesses. The temporary holding parts 23 hold the in-core 4 when the in-core 4 is temporarily inserted into the inner cylinder 12. In the in-core 4, a tapered face 43b which becomes small in a diameter as approaching a tip face 43a is formed at an external peripheral face of a second end part 43, and a small-diameter part 43c is provided at a portion adjoining the tip face 43a at an internal peripheral face of the in-core 4.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an in-core that is inserted into a piping member for supplying hot and cold water, for example. [Background technology]

[0002] As shown in Fig. 6, the piping joint 100 of Patent Document 1 includes a first flow path member 101 having an outer cylindrical portion 101a, a second flow path member 102 having an inner cylindrical portion 102a inserted and snap-engaged into the outer cylindrical portion 101a, and a cylindrical incore 103 inserted into the inner cylindrical portion 102a to strengthen the snap engagement between the inner cylindrical portion 102a and the outer cylindrical portion 101a. In the incore 103, a tapered surface 104a is formed on the outer peripheral surface of an end portion 104 located on the insertion side into the inner cylindrical portion 102a to facilitate the insertion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-125549 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the piping joint 100 of Patent Document 1, when the inclination angle of the tapered surface 104a is set small to facilitate insertion of the inner core 103 into the inner cylindrical portion 102a, the end portion 104 of the inner core 103 becomes sharp. Therefore, there is a problem that the inner peripheral surface of the inner cylindrical portion 102a is scraped by the tip surface 104b of the inner core 103 during the insertion.

[0005] In particular, in the piping joint 100 of Patent Document 1, a plurality of temporary holding portions 105 for temporarily holding the shallowly inserted end portion 104 of the incore 103 are provided at intervals in the circumferential direction on the end portion of the inner circumferential surface of the inner cylindrical portion 102a located on the insertion side of the incore 103. In other words, the inner circumferential surface of the inner cylindrical portion 102a has a partially solid portion (temporary holding portion 105) in the circumferential direction. Therefore, the insertion force of the incore 103 is likely to concentrate on the temporary holding portion 105 on the inner circumferential surface of the inner cylindrical portion 102a, and the above-mentioned problem of the inner circumferential surface of the inner cylindrical portion 102a being scraped has become prominent.

[0006] An object of the present invention is to provide an in-core that can easily be inserted into a piping member while preventing the piping member from being scraped during the insertion at a high level. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the invention of claim 1 is a cylindrical incore that is inserted into a piping member, wherein an outer peripheral surface of an end portion positioned on the insertion side into the piping member is formed with a tapered surface that becomes smaller in diameter as it approaches a tip surface of the end portion, and a portion of the inner peripheral surface adjacent to the tip surface has a smaller diameter than a portion away from the tip surface, and the axial length of the small diameter portion is less than half the axial length of the incore. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a longitudinal sectional view of a piping joint according to an embodiment. [Diagram 2] FIG. 2 is an enlarged view of the main part of FIG. 1. [Diagram 3] FIG. [Figure 4] FIG. 4 is a vertical cross-sectional view showing a state in which the in-core is temporarily inserted into the second flow path member. [Diagram 5] FIG. 11 is a vertical cross-sectional view of a pipe joint according to another embodiment. [Figure 6] FIG. 1 is a vertical cross-sectional view showing a conventional piping joint. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] An embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG. As shown in FIG. 1, the piping joint 1 includes a cylindrical first flow path member 2 made of metal, resin or the like, a cylindrical second flow path member 3 made of resin engaged with the first flow path member 2, and an in-core 4 made of metal or hard resin that is inserted into the second flow path member 3 as a piping member and that realizes long-term engagement between the first flow path member 2 and the second flow path member 3.

[0010] A male thread 5 for connecting the piping joint 1 to a device (not shown) such as a water heater is formed on the outer peripheral surface of one end (the left end in FIG. 1) of the first flow path member 2. An outer tubular portion 6 for attaching the second flow path member 3 is provided on the other end (the right end in FIG. 1) of the first flow path member 2. An inwardly directed claw portion 8 and two accommodation grooves 10 for accommodating seal rings 9 are formed annularly on the inner peripheral surface of the outer tubular portion 6 in the circumferential direction.

[0011] An electric heating coil 13 is embedded in one end (the right end in FIG. 1) of the second flow path member 3. A pair of electrodes 14 connected to the electric heating coil 13 protrude to the outside of the second flow path member 3. When a resin pipe (not shown) is inserted into the electric heating coil 13 and a current is passed through the electric heating coil 13 via the pair of electrodes 14, the contact portions between the resin pipe and the second flow path member 3 melt and are joined to each other.

[0012] An inner cylinder portion 12 is provided on the other end (the left end portion in FIG. 1) side of the second flow path member 3. The inner cylinder portion 12 is inserted into the outer cylinder portion 6 of the first flow path member 2. An outward claw portion 16 is formed in an annular shape in the circumferential direction on the outer peripheral surface of the inner cylinder portion 12. The outer cylinder portion 6 (first flow path member 2) and the inner cylinder portion 12 (second flow path member 3) are prevented from coming off from each other by snap engagement between the inward claw portion 8 and the outward claw portion 16.

[0013] The inner circumferential surface of the second flow path member 3 is provided with a first step 18 located at the tip of the inner cylindrical portion 12 and a second step 19 located on the heating wire coil 13 side. A cylindrical inner core 4 is inserted and disposed on the inner circumferential surface of the inner cylindrical portion 12 on the second step 19 side, i.e., the larger diameter side, with the first step 18 as the boundary. A flange 41a is formed on the outer circumferential surface of a first end portion 41 (the right end portion in FIG. 1 ) of the inner core 4. The flange 41a abuts against the second step 19 to determine the insertion position of the inner core 4 relative to the inner cylindrical portion 12.

[0014] By inserting the in-core 4 into the inner cylindrical portion 12, the portion of the inner cylindrical portion 12 corresponding to the outward claw portion 16 is prevented from being deformed in the radially reducing direction, and thus the snap engagement between the outward claw portion 16 and the inward claw portion 8 is prevented from being released. In other words, the snap engagement between the outward claw portion 16 and the inward claw portion 8 is made strong by the in-core 4, and the snap engagement is maintained for a long period of time.

[0015] As shown in Fig. 3, a plurality of recesses 21 extending in the circumferential direction are formed in the end portion on the second step 19 side (the end portion located on the insertion side of the incore 4) on the inner peripheral surface of the inner cylindrical portion 12. A temporary holding portion 23 is provided between each of the adjacent recesses 21. The temporary holding portions 23 are provided at equal intervals in the circumferential direction on the inner peripheral surface of the inner cylindrical portion 12. As shown in Fig. 4, when the second end portion 43 (the left end portion in Fig. 3; the end portion located on the insertion side into the inner cylindrical portion 12) of the incore 4 is inserted (temporarily inserted) shallower than a predetermined insertion position into the inner cylindrical portion 12, the temporary holding portion 23 is pressed against the outer peripheral surface of the second end portion 43 to securely hold the incore 4.

[0016] Here, an assembly procedure may be adopted in which the inner cylindrical portion 12 is inserted into the outer cylindrical portion 6 of the first flow path member 2 in a state in which the second end portion 43 of the incore 4 is temporarily inserted into the inner cylindrical portion 12. In this case, the inner cylindrical portion 12 (outward claw portion 16) is likely to deform during the snap engagement due to the recess 21 (see FIG. 3) formed on the inner peripheral surface of the inner cylindrical portion 12. This is because, when the inner cylindrical portion 12 tries to deform in the radially reducing direction, the material of the temporary holding portion 23 that contacts the outer peripheral surface of the second end portion 43 of the incore 4 escapes toward the recess 21. Therefore, even in a state in which the incore 4 is temporarily inserted into the inner cylindrical portion 12, the task of snap engagement of the inner cylindrical portion 12 with the outer cylindrical portion 6 is not difficult.

[0017] As shown in FIG. 2, the tip surface 43a of the second end 43 of the incore 4 is a flat surface extending in a direction perpendicular to the axis of the incore 4. A tapered surface 43b is formed on the outer circumferential surface of the second end 43 of the incore 4, the diameter of which decreases as it approaches the tip surface 43a. The tapered surface 43b facilitates the insertion of the incore 4 into the inner cylindrical portion 12. A portion of the inner circumferential surface of the second end 43 adjacent to the tip surface 43a protrudes radially inward more than a portion away from the tip surface 43a, forming a small diameter (small diameter portion 43c). The inner diameter of the cylindrical surface of the small diameter portion 43c is approximately the same as the inner diameter of the cylindrical surface on the small diameter side of the first step 18.

[0018] Although the incore 4 has a tapered surface 43b formed on the outer peripheral surface of the second end 43, the small diameter portion 43c ensures that the radial width, i.e., the area, of the tip surface 43a is relatively large. Therefore, the second end 43 of the incore 4 is not sharp, and even under adverse conditions such as when the temporary holding portion 23 is provided as in this embodiment, the insertion force of the incore 4 is prevented from concentrating on the temporary holding portion 23. This makes it possible to avoid the problem of the inner peripheral surface of the inner tube portion 12 being scraped by the tip surface 43a of the incore 4 during the insertion.

[0019] It is possible to prevent the second end 43 of the incore 4 from becoming sharp by reducing the diameter of the entire inner circumferential surface of the incore 4, including not only the portion adjacent to the tip surface 43a but also the portion away from the tip surface 43a. However, in this case, the incore 4 becomes thick overall, resulting in increased weight and cost, and the rigidity of the incore 4 becomes excessively high, making it difficult to insert into the inner cylindrical portion 12, and further increasing the flow resistance that the fluid experiences when passing through the inside of the incore 4.

[0020] Taking into consideration these problems and the need to ensure the strength of small diameter portion 43c, which is the protruding portion, it is preferable that the size of small diameter portion 43c, particularly its length in the axial direction, corresponds to the entire area from tip surface 43a to tapered surface 43b, and it is preferable that the length be no longer than half the axial length of in-core 4 and no longer than twice the axial length of tapered surface 43b.

[0021] (Another example) The above embodiment can be modified, for example, as follows. 5, this is realized in an in-core 62 that is inserted into the end of a resin pipe 61 serving as a piping member that is connected to a one-touch joint 51. The structure of the one-touch joint 51 is a well-known one that includes a lock ring 52, a seal ring 53, etc., and therefore detailed description thereof will be omitted.

[0022] The incore 62 is prevented from being immersed in the resin pipe 61 by a flange 63a formed on a first end 63 of the incore 62. The end of the resin pipe 61 with the incore 62 inserted therein is inserted into the one-touch joint 51 and is prevented from coming off by a lock ring 52, and is watertight by a seal ring 53.

[0023] A tapered surface 64b that becomes smaller in diameter approaching the tip surface 64a of the second end 64 is formed on the outer circumferential surface of the in-core 62. The tapered surface 64b makes it easy to insert the in-core 62 into the resin pipe 61. A portion of the inner circumferential surface of the second end 64 adjacent to the tip surface 64a protrudes radially inward more than a portion away from the tip surface 64a and has a smaller diameter (small diameter portion 64c).

[0024] By providing the small diameter portion 64c, the radial width, i.e., the area, of the tip surface 64a of the incore 62 is ensured to be relatively large, even though the tapered surface 64b is formed on the outer circumferential surface of the second end portion 64. Therefore, the second end portion 64 of the incore 62 is not sharp, and it is possible to avoid the problem of the inner circumferential surface of the resin pipe 61 being scraped by the tip surface 64a when the incore 62 is inserted.

[0025] By making the inner surface of the in-core 4, 62 a tapered surface that becomes smaller in diameter as it approaches the tip surface 43a, 64a of the second end portion 43, 64, the smallest diameter portion of the tapered surface adjacent to the tip surface 43a, 64a is made into the small diameter portion 43c, 64c.

[0026] ○Remove flange 17 from incore 4, 62. [Explanation of symbols]

[0027] 1...piping joint, 2...first flow path member, 3...second flow path member, 4...incore, 6...outer tube portion, 12...inner tube portion, 21...recess, 23...temporary holding portion, 43...second end portion, 43a...tip surface, 43b...tapered surface, 43c...small diameter portion.

Claims

[Claim 1] An incore for a piping member, which is a cylindrical incore to be inserted into a piping member, wherein an outer peripheral surface of an end portion located on the insertion side into the piping member has a tapered surface that becomes smaller in diameter as it approaches a tip surface of the end portion (the tip surface is a plane extending in a direction perpendicular to the axis of the incore), and a portion of the inner peripheral surface adjacent to the tip surface protrudes radially inward so that the inner diameter of the cylindrical surface of the protruding portion is smaller than that of a portion away from the tip surface, the length in the axial direction of the small diameter portion is less than half the length of the incore in the axial direction, and the outer peripheral surface corresponding to the small diameter portion is a single cylindrical surface excluding the tapered surface.

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