Elbow joint for piping

Abstract

To provide an elbow joint for piping which can accommodate a mismatch in length, angle and the like in machine piping with a simple configuration.SOLUTION: An elbow joint for piping includes: an elbow pipe; an outer cylinder with one end fixed to one end of the elbow pipe; and an inner cylinder inserted into the outer cylinder in a movable manner. An annular groove is formed to surround a center axis of the outer cylinder on an inner peripheral face of the outer cylinder. There are formed a first tapered part with a diameter decreasing from one end side of the outer cylinder toward the groove on an inner peripheral face of the outer cylinder, and a second tapered part with a diameter decreasing from the other end side of the outer cylinder toward the groove. On an outer peripheral face of the inner cylinder, a sliding face is formed which slides against the inner peripheral face of the outer cylinder and that forms a constant outer diameter in a center axial direction of the inner cylinder. A cross-sectional face of a bottom part of the groove is formed in an arc shape with a center part in a center axial direction of the outer cylinder being deepest. A radius of the arc is smaller than a distance from the center axis of the outer cylinder to the center part of the bottom part. An O-ring is fitted into the groove, the O-ring sealing between the inner peripheral face of the outer cylinder and the outer peripheral face of the inner cylinder.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a piping elbow joint used for connecting equipment piping. [Background technology]

[0002] When connecting a pump to a device, the flanges of the water pipes are connected by flush fitting. In this case, it is rare that the water pipes can be positioned with the required accuracy at their original lengths, angles, etc. Therefore, in many cases, flexible pipes with bellows structures made of rubber, resin, or metal (Patent Documents 1 and 2), expansion joints (Patent Document 3), etc. are used to adjust for deviations in the length, angle, etc. of the water pipes and prevent water leakage from the water pipes. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-083060 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-108174 [Patent Document 3] Japanese Patent Application Laid-Open No. 2012-117607 Summary of the Invention [Problem to be solved by the invention]

[0004] Water-carrying piping is used in various places. However, in the case of high-density land-based aquaculture, greenhouse hydroponic cultivation, and other such facilities, site area and spatial volume are limited, requiring the miniaturization of piping and equipment for aquaculture tanks and cultivation, and various requirements are placed on equipment piping. However, conventional flexible pipes are difficult to bend with small curvatures like conventional elbow joints due to their material and structural constraints. Furthermore, while expansion joints can accommodate length changes in the central axis direction, they have difficulty accommodating angular misalignments. Furthermore, flexible joints such as those described in Patent Documents 1 and 2 have difficulty accommodating length changes and are complex and expensive in structure. Expansion joints such as those described in Patent Document 3 can accommodate length changes, but are also complex and expensive in structure. Because facilities such as high-density land-based aquaculture and greenhouse hydroponic cultivation are subject to significant capital investment constraints, equipment piping with simpler structures and lower costs is required. For these reasons, there is a demand for equipment piping structures that require simple bent joints that can minimize space occupancy.

[0005] An object of the present invention is to provide a piping elbow joint that has a simple structure and can accommodate deviations in length, angle, etc. in equipment piping. [Means for solving the problem]

[0006] A first aspect of the present invention provides an elbow fitting for piping, comprising an elbow pipe, an outer tube having one end fixed to the other end of the elbow pipe, and an inner tube movably inserted into the outer tube. The inner surface of the outer tube has an annular groove surrounding the central axis of the outer tube, and the inner surface of the outer tube has a first tapered portion whose diameter decreases from one end of the outer tube toward the groove and a second tapered portion whose diameter decreases from the other end of the outer tube toward the groove. The outer surface of the inner tube has a sliding surface that slides against the inner surface of the outer tube and forms a constant outer diameter in the central axis direction of the inner tube. The cross section of the bottom of the groove is arc-shaped, with the deepest point at the center of the central axis of the outer tube, and the radius of the arc is smaller than the distance from the central axis of the outer tube to the center of the bottom. An O-ring is fitted in the groove, and the O-ring seals the gap between the inner surface of the outer tube and the outer surface of the inner tube.

[0007] With a piping elbow fitting having such a configuration, the outer tube and elbow pipe can slide and tilt relative to the inner tube, allowing the relative positions and orientations of both ends of the piping elbow fitting to be freely changed.

[0008] In the elbow joint for piping according to the second aspect of the present invention, the cross-sectional area of ​​the groove is 1.1 to 1.5 times the cross-sectional area of ​​the O-ring.

[0009] In the elbow joint for piping according to the third aspect of the present invention, a joint portion is provided at the other end of the elbow pipe.

[0010] In the elbow joint for piping according to the fourth aspect of the present invention, a joint portion is provided on the other end side of the inner cylinder. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide an elbow joint for piping that has a simple structure and can accommodate deviations in length, angle, etc. in equipment piping. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 2 is a cross-sectional view of a piping elbow joint. [Figure 2] FIG. 2 is a front view of the piping elbow joint. [Figure 3] FIG. [Figure 4] 1 is a cross-sectional view of the outer cylinder, and the right half is a cross-sectional view of the outer cylinder with an O-ring attached. [Figure 5] 1 is a cross-sectional view of the elbow joint for piping with the outer tube and the elbow pipe slid. FIG. [Figure 6] 10 is a cross-sectional view of the elbow fitting for piping with the outer cylinder and the elbow pipe tilted. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, a piping elbow fitting 1 according to an embodiment of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, the piping elbow fitting 1 of this embodiment has an elbow pipe 2, an outer cylinder 3, an inner cylinder 4, and an O-ring 5. The piping elbow fitting 1 is used for equipment piping. For example, the piping elbow fitting 1 can be used for water piping connecting a pump and a gas dissolving device. There are no particular limitations on the equipment for which the piping elbow fitting 1 can be used, and it can be used for a variety of equipment. Furthermore, the material passing through the piping elbow fitting 1 is not limited to liquids such as water, but can also be gas.

[0014] As shown in Figures 1 and 2, the elbow pipe 2 is a curved pipe bent at 90 degrees. The bending angle of the elbow pipe 2 is not limited to 90 degrees. In this embodiment, the elbow pipe 2 has an outer tube 3 fixed to one end and a flange 6 provided as a joint portion at the other end. The flange 6 is used to fix the piping elbow fitting 1 to a flange of a pipe of equipment, etc. A plurality of through holes 61 are formed in the flange 6. The through holes 61 are used to fix the elbow pipe 2 to the flange of a pipe of equipment, etc. with bolts and nuts. The form of the joint portion is not limited to the flange 6, and various forms are possible, such as a pipe joint.

[0015] The outer cylinder 3 has a cylindrical shape. As shown in FIGS. 1 and 2, one end of the outer cylinder 3 is fixed to the elbow pipe 2. The inner cylinder 4 is inserted into the opening at the other end of the outer cylinder 3. As shown in FIG. 3, the outer cylinder 3 has an annular groove 31 formed on the other end of its inner circumferential surface. The groove 31 is formed to surround the central axis N of the outer cylinder 3. An O-ring 5 is fitted in the groove 31. As shown in FIG. 3, in this embodiment, the groove 31 has two opposing wall portions 31b and a bottom portion 31a connecting the two wall portions 31b. The bottom portion 31a in the cross section of the groove 31 is formed in an arc shape that is deepest at the center in the direction of the central axis N. As shown in FIG. 3, the radius R1 of the bottom portion 31a of the groove 31 is smaller than the distance R2 from the central axis N of the outer cylinder 3 to the center of the bottom portion 31a of the groove 31. As a result, the O-ring 5 fitted in the groove 31 is less likely to deform locally, and the compression allowance of the O-ring 5 can be maintained at an appropriate value over the entire circumference of the O-ring 5.

[0016] The O-ring 5 fitted in the groove 31 provides a seal between the inner peripheral surface of the outer tube 3 and the outer peripheral surface of the inner tube 4. The cross-sectional area A1 of the groove 31 (see FIG. 4) is preferably 1.1 to 1.5 times the cross-sectional area A2 of the O-ring 5 (see FIG. 4). This relationship between the cross-sectional areas of the groove 31 and the O-ring 5 prevents the rubber O-ring 5 from being excessively crushed in the groove 31 or from having an insufficient crush rate. The O-ring 5 also provides a reliable seal between the outer tube 3 and the inner tube 4.

[0017] 4, a first tapered portion 32 is formed on the inner peripheral surface of the outer cylinder 3, the diameter of which decreases from one end toward the groove 31. Furthermore, a second tapered portion 33 is formed on the inner peripheral surface of the outer cylinder 3, the diameter of which decreases from the other end toward the groove 31. In this way, the inner peripheral surface of the outer cylinder 3 has a double-tapered shape.

[0018] The inner cylinder 4 is movably inserted into the outer cylinder 3 from one end. As shown in FIG. 1, a sliding surface 41 that slides against the inner peripheral surface of the outer cylinder 3 is formed on the outer peripheral surface of the inner cylinder 4. The sliding surface 41 has a constant outer diameter in the direction of the central axis of the inner cylinder 4. When the outer cylinder 3 and the elbow pipe 2 are not tilted relative to the inner cylinder 4 as shown in FIG. 1, the central axis of the inner cylinder 4 coincides with the central axis N of the outer cylinder 3. At this time, the sliding surface 41 is hardly in contact with the inner peripheral surface of the outer cylinder 3, which has a double-tapered shape, and is in contact almost only with the O-ring 5. The portion of the outer peripheral surface of the inner cylinder 4 other than the sliding surface 41 may have an outer diameter different from that of the sliding surface 41.

[0019] A flange 7 is provided as a joint portion on the other end side of the inner tube 4 exposed from the outer tube 3. The flange 7 is used to fix and connect the piping elbow fitting 1 to a flange of a pipe of equipment or the like. As shown in FIG. 2, a plurality of through holes 71 are formed in the flange 7. The form of the joint portion is not limited to the flange 7, and various forms such as a pipe joint are possible. The length of the inner tube 4 from the sliding surface 41 on the outer circumferential surface to the joint portion can be changed as appropriate.

[0020] In this embodiment, stainless steel is used as the material for the elbow pipe 2, outer cylinder 3, and inner cylinder 4. However, the materials for the elbow pipe 2, outer cylinder 3, and inner cylinder 4 are not particularly limited, and materials appropriate for the equipment to be used can be used. Furthermore, the lengths of the outer cylinder 3 and inner cylinder 4 can also be changed as appropriate.

[0021] In the piping elbow fitting 1 of this embodiment, the gap between the outer tube 3 and the inner tube 4 is sealed by an O-ring 5 attached to the groove 31. This allows the outer tube 3 and the elbow pipe 2 to slide relative to the inner tube 4, as shown in Figure 5. The amount of sliding of the outer tube 3 and the elbow pipe 2 is determined by the lengths of the outer tube 3 and the inner tube 4. The amount of sliding of the piping elbow fitting 1 can be changed by changing the lengths of the outer tube 3 and the inner tube 4.

[0022] In the piping elbow fitting 1 of this embodiment, a first tapered portion 32 and a second tapered portion 33 are formed on the inner peripheral surface of the outer cylinder 3. Furthermore, a sliding surface 41 having a constant outer diameter in the direction of the central axis of the inner cylinder 4 is formed on the outer peripheral surface of the inner cylinder 4. The first and second tapered portions 32, 33 of the outer cylinder 3 and the sliding surface 41 of the inner cylinder 4 allow the outer cylinder 3 and the elbow pipe 2 to tilt relative to the inner cylinder 4. Figure 6 shows the outer cylinder 3 and the elbow pipe 2 tilted to the right relative to the inner cylinder 4. The direction in which the outer cylinder 3 and the elbow pipe 2 tilt relative to the inner cylinder 4 is not limited, and the outer cylinder 3 can tilt in the entire circumferential direction of the central axis N. By combining sliding movement and tilting, the outer cylinder 3 and the elbow pipe 2 can be moved in various directions relative to the inner cylinder 4.

[0023] Furthermore, the piping elbow fitting 1 of this embodiment also allows the outer tube 3 and the elbow pipe 2 to rotate about the central axis N relative to the inner tube 4. This allows the piping elbow fitting 1 to adjust the angle in the circumferential direction of the central axis N.

[0024] In this way, the piping elbow fitting 1 of this embodiment has a simple structure in which the outer tube 3 and elbow pipe 2 can slide and tilt relative to the inner tube 4, so that it can absorb deviations in the length, angle, etc. of the pipes connecting the objects to be connected, and can connect the pipes without leaking.

[0025] Furthermore, the piping elbow fitting 1 of this embodiment allows the outer tube 3 and elbow pipe 2 to be slid, tilted, and rotated easily by hand without using tools, etc., so adjustment of the piping elbow fitting 1 can be easily performed. [Industrial Applicability]

[0026] The present invention is applicable to, for example, a piping elbow joint used to connect equipment such as a pump. [Explanation of symbols]

[0027] 1. Pipe elbow fitting 2 elbow pipes 3 Outer cylinder 31 Groove 31a bottom 31b Wall section 32 First tapered section 33 Second tapered section 4 Inner cylinder 41 Sliding surface 5 O-rings 6 flange 61 Through hole 7 flange 71 Through hole N center axis

Claims

1. An elbow pipe, an outer cylinder having one end fixed to one end of the elbow pipe; an inner cylinder movably inserted into the outer cylinder; A piping elbow joint comprising: an annular groove is formed on the inner peripheral surface of the outer cylinder so as to surround the central axis of the outer cylinder; a first tapered portion whose diameter decreases from one end side of the outer cylinder toward the groove, and a second tapered portion whose diameter decreases from the other end side of the outer cylinder toward the groove, a sliding surface that slides against the inner peripheral surface of the outer cylinder and forms a constant outer diameter in the central axis direction of the inner cylinder is formed on the outer peripheral surface of the inner cylinder, The cross section of the bottom of the groove is formed in an arc shape that is deepest at the center in the central axis direction of the outer cylinder, the radius of the arc is smaller than the distance from the central axis of the outer cylinder to the center of the bottom portion, An O-ring is fitted in the groove, The O-ring seals the gap between the inner circumferential surface of the outer cylinder and the outer circumferential surface of the inner cylinder. An elbow fitting for piping characterized by:

2. The cross-sectional area of ​​the groove is 1.1 to 1.5 times the cross-sectional area of ​​the O-ring.

2. The piping elbow joint according to claim 1.

3. A joint portion is provided at the other end of the elbow pipe.

3. The piping elbow joint according to claim 1 or 2.

4. A joint portion is provided on the other end side of the inner cylinder.

3. The piping elbow joint according to claim 1 or 2.

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