Union joint

Abstract

To provide a pipe joint which has a lighter weight, easy pipe connection operation and excellent pressure resistance.SOLUTION: A union joint includes a nut member and a male screw member, the nut member having a ring-shaped nut body part, and a plurality of fastening protrusion parts provided on the outer periphery side of the nut body part at preset spaces, the male screw member having a ring-shaped male screw body part, and a plurality of protrusion parts provided on the outer periphery side of the male screw body part at preset spaces. A pair of pipe material each have a flange part at the end, and a seal member is held between the pair of flange parts to fasten the pair of flange parts from both sides with the nut member and the male screw member.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a union joint used for connecting pipes. [Background technology]

[0002] A union type joint is a joint that is divided into a union nut and a union thread, and has generally been used for small diameter pipes, especially plastic pipes. For example, Patent Document 1 discloses a union-type fitting in which a slit is formed in the union nut so that the fitting can be attached to a pipe having a flange from the outside of the side of the pipe, which is applied to small diameter pipes such as air conditioner pipes. In contrast, flange-type joints have generally been used up until now for connecting large piping such as steel pipes with outer diameters of 65 to 200A. Flange-type joints are relatively heavy because they are fastened with multiple bolts and nuts, and their uneven shape makes it difficult to wrap the thermal insulation material around them. In addition, multiple bolts and nuts had to be fastened, which caused a lot of man-hours for connecting the piping. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-211054 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a pipe joint which is lightweight, easy to connect to pipes, and has excellent pressure resistance. [Means for solving the problem]

[0005] The union type joint of the present invention is a union type joint consisting of a nut member and a male thread member, wherein the nut member has a ring-shaped nut main body and a plurality of fastening protrusions provided at a predetermined interval on the outer circumferential side of the nut main body, the male thread member has a ring-shaped male thread main body and a plurality of protrusions provided at a predetermined interval on the outer circumferential side of the male thread main body, a pair of pipe materials each have a flange portion at an end, a sealing member is sandwiched between the pair of flange portions, and the nut member and the male thread member fasten the pair of flange portions from both sides.

[0006] In this way, by making the nut body and the male thread body into a ring shape and providing multiple tightening protrusions along the outer periphery of the ring shape, even large pipe materials with outer diameters of 65 to 200A can be tightened with an adjustable wrench, hook wrench, etc. Furthermore, in the present invention, if the root diameter of the female thread portion of the nut member is formed into a trapezoidal thread smaller than the metric thread specified by JIS, or the inner diameter of the socket portion of the female thread portion is set smaller than the general portion, the center misalignment is reduced when the nut member and the male thread member are butted together, making the tightening operation easier.

[0007] In the present invention, it is preferable that the nut member has a fastening portion having an outer diameter smaller than the outer diameter of the nut body portion, has the plurality of fastening protrusions on the outer periphery of the fastening portion, and the size of the circumscribed circle of the plurality of fastening protrusions is smaller than the outer diameter of the nut body portion. Furthermore, it is preferable that the male screw member has a fastening portion having an outer diameter smaller than the outer diameter of the male screw main body, has the plurality of fastening protrusions on the outer periphery of the fastening portion, and has a size of a circumscribed circle of the plurality of fastening protrusions smaller than the outer diameter of the male screw main body. This makes the material lighter and makes it easier to wrap the material around it.

[0008] In the present invention, the nut body may have a plurality of confirmation holes at predetermined intervals along the outer circumferential surface, and the confirmation holes may enable the seal portion and fastening position of the seal member to be visually confirmed from the outside. In this way, by providing a plurality of inspection holes at predetermined intervals along the outer peripheral surface of the nut body, it becomes easy to check for leakage from the seal portion over the entire circumference, even in cases where the pipe diameter is large. Furthermore, if a mark or the like indicating the appropriate fastening position is provided on the side of the confirmation hole of the nut member, fastening can be easily controlled by fastening the nut to that position. Here, it is preferable that the seal member has a metal ring on the outer periphery and an elastic packing disposed inside the metal ring. If a metal ring made of metal is provided on the outer periphery as a sealing member, the high pressure resistance is improved, the tightening position when connecting the piping is determined, and the conventional torque management is not required. In addition, the elastic packing made of rubber or the like arranged on the inside is prevented from being excessively compressed, and since it has a metal ring on the outside, the elastic packing will not bulge or protrude toward the confirmation hole when internal pressure is applied.

[0009] In the present invention, a means for preventing loosening of the joint may be provided between the nut member and the male thread member. Effect of the Invention

[0010] The union type joint of the present invention has multiple fastening protrusions around the outer circumference when screwing together a ring-shaped nut member and a ring-shaped male threaded member, even when connecting large diameter steel pipes. Therefore, the fastening protrusions on the nut member and the fastening protrusions on the male threaded member can be grasped with a general-purpose tool such as a monkey wrench and fastened together or a hook spanner can be hooked onto the fastening protrusions to fasten them together. By making the nut member and the male screw member out of metal, the pressure resistance is also excellent. This makes it possible to reduce the weight by about half compared to conventional flange-type joints consisting of multiple bolts and nuts of the same size, and also significantly reduces the labor required for connecting the piping. In addition, since the nut member and the male screw member are generally cylindrical in shape, the application of the heat insulating material becomes easy. [Brief description of the drawings]

[0011] [Figure 1] 1 shows an example of the configuration of a union joint according to the present invention. [Diagram 2] (a) to (c) show the flow of piping connection work. [Diagram 3] An example of tightening using a hook spanner is shown below. [Figure 4] (a) to (c) are cross-sectional views showing the connection flow. [Diagram 5] 1A shows the confirmation hole and the locking member, and FIG. 1B shows an enlarged view of the confirmation hole. [Figure 6] An example of an improved female thread shape is shown below. [Figure 7] An explanatory diagram for a conventional M screw is shown. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] An example of the structure of a union joint according to the present invention will be described below with reference to the drawings, but the present invention is not limited thereto.

[0013] FIG. 1 shows a perspective view of a nut member 10 and a male screw member 20. As shown in FIG. The nut member 10 has a ring-shaped nut main body 11, and a step portion is provided on the outside of the nut main body 11 opposite the male screw member 20 so that the outer diameter is smaller than the outer diameter of the nut main body 11, forming a concentric tightening portion 11a. A plurality of fastening projections 13 are provided at predetermined intervals along the outer circumferential surface of the ring-shaped fastening portion 11a. In this embodiment, six fastening protrusions 13 are arranged radially at equal intervals, but the number is not limited as long as it is four or more. Moreover, the size of the circumscribed circle of the multiple fastening protrusions 13 is smaller than the outer diameter dimension of the nut body 11 .

[0014] A double-threaded female thread 12 is formed on the inner peripheral surface of the nut body 11 to reduce the number of tightening steps, and a plurality of confirmation holes 14 are provided at predetermined intervals. In the case of a pipe having a large outer diameter, it is difficult to check for leakage along the entire circumference of the pipe, but by providing a plurality of checking holes around the circumference in this way, it is possible to easily check along the entire circumference. In this embodiment, twelve locations are provided as an example, but six or more locations are preferable.

[0015] The male screw member 20 has a ring-shaped male screw main body 21 with a two-threaded male screw portion 22 formed along the outer periphery, and on the outside (opposite the nut main body) a fastening portion 21a having an outer diameter smaller than the outer diameter of the male screw main body 21 is formed via a step portion. The fastening portion 21a has a plurality of fastening protrusions 23 at predetermined intervals along the outer circumferential surface thereof. The size of a circumscribing circle of the multiple fastening protrusions 23 is smaller than the outer diameter of the male thread main body 21 .

[0016] Next, the flow of the pipe connection work will be described with reference to Figs. 2 and 3 and Fig. 4 showing a cross section of the screw-in portion. As shown in FIG. 2, a flange portion 1a is formed at the end of the pipe material 1 by flaring, welding or the like. In FIG. 2, such a pipe material 1 is connected to the piping by butting its left and right ends together and sandwiching a seal member 2 between the pair of ends. In this embodiment, the seal member 2 has a ring-shaped metal ring 2a on the outer periphery, and a self-sealing type elastic packing 2b on the inside. This metal ring 2a prevents excessive tightening.

[0017] As shown in Figures 2(b) and (c), a nut member 10 having a cylindrical insertion opening on the inside is attached along the outer periphery of one of the pipes, and a male thread member 20 having a cylindrical insertion opening on the inside is attached along the outer periphery of the other pipe. Here, the inner diameters of the insertion holes of the nut member 10 and the male screw member 20 correspond to the outer diameter of the pipe material 1 and are smaller than the outer diameter of the flange portion 1a.

[0018] As shown in FIG. 4, the seal member 2 and the flange portions 1a, 1a on both sides thereof are clamped between a donut-shaped pressing surface 11b on the end face of the nut member 10 and a donut-shaped pressing surface 21b on the end face of the male screw member 20. As a tightening tool, one of the tightening protrusions 13 on the nut member 10 side may be grasped with one monkey wrench and the tightening protrusion 23 on the male screw member 20 side may be grasped with the other monkey wrench to tighten them together, or a hook spanner 3 may be used to hook onto one of the tightening protrusions 13, 23 and tighten them as shown in Figure 3.

[0019] As shown in FIG. 5(a), the nut member 10 has a plurality of through-holes 14 around the circumference of the nut body 11, and the sealing condition of the sealing portion can be checked, as shown in an enlarged view in FIG. 5(b). The multiple confirmation holes 14 allow confirmation over the entire circumference even of large diameter pipe material. In this embodiment, furthermore, the appropriate fastening position for each type of pipe is indicated on the circumferential side of the confirmation hole 14. For example, lines A, B, and C are shown. This makes it easier to perform fastening work since the appropriate fastening position is known according to the type of pipe.

[0020] In the present invention, for example, by providing a pin or the like between the nut member 10 and the male screw member 20 that protrudes toward the mating side, it is possible to prevent the threaded portion from loosening. In this embodiment, as shown in FIG. 5(a), a plurality of locking claws 15 are provided at equal intervals around the periphery of the nut member 10 on the male screw member 20 side, and a mounting groove for a locking member 40 is formed between adjacent locking claws 15. After the nut member 10 and the male screw member 20 are fastened together, when the locking member 40 is attached to the attachment groove portion between the locking claws 15 as shown in FIG. 5(a), this locking member 40 engages with the fastening protrusion 23 on the male screw member 20 side, thereby preventing the screwed portion from loosening. The locking member is made of a spring material or the like and is capable of being snapped into place.

[0021] The union type joint according to the present invention has a cylindrical shape as a whole as shown in FIG. 3, so that it is easy to wind the thermal insulation material around it. In addition, the number of tightening steps is smaller and the weight is lighter than that of conventional flange-type joints consisting of multiple bolts and nuts.

[0022] When installing large pipes horizontally, there were the following problems with centering the male and female threads. This will be explained with reference to Figure 7. If metric threads specified by JIS are used as is, and the female thread portion has a crest diameter 112b and a root diameter 112a, and the male thread portion has a crest diameter 122b and a root diameter 122a, there is a relatively large clearance between them. Therefore, when laying piping horizontally, the weight of the male threaded pipe material, etc., causes the axis 22c on the male threaded portion to drop, resulting in a misalignment with the axis 12c on the female threaded portion, making it difficult to align the axes of the threaded portions. Therefore, in the present invention, as shown in FIG. 6, the root diameter 12a of the female thread is made smaller and closer to the thread ridge diameter 22b of the male thread, and the clearance is set to 0.2 mm or less. The thread ridge diameter 12b of the female thread and the thread root diameter 22a of the male thread are set to the same as those of the M thread. This makes it possible to prevent misalignment of the axial cores between the female thread side and the male thread side, improving piping workability. In this case, if a clearance of about 0.2 to 1.0 mm is provided between the opening diameter of the male and female threaded members and the outer diameter of the pipe, any deviation in the central axis of the pipe can be easily absorbed. The same effect can be obtained by reducing only the inner diameter of the socket part while leaving the female thread as an M thread. [Explanation of symbols]

[0023] 10 Nut member 11 Nut body 11a Fastening part 12 Female thread 13 Fastening protrusion 14 Check hole 15 Locking claw 20 Male threaded member 21 Male thread body 21a Fastening part 22 Male thread 23 Fastening protrusion

Claims

1. A union type joint consisting of a nut member and a male thread member, The nut member has a ring-shaped nut body and a plurality of fastening protrusions provided at predetermined intervals on the outer circumferential side of the nut body, The male screw member has a ring-shaped male screw main body and a plurality of protrusions provided at predetermined intervals on the outer circumferential side of the male screw main body, A union type joint characterized in that a pair of pipes each have a flange portion at an end, a sealing member is sandwiched between the pair of flange portions, and the pair of flange portions are fastened from both sides by the nut member and the male thread member.

2. 2. A union type joint as claimed in claim 1, characterized in that the root diameter of the female thread portion of the nut member is formed into a trapezoidal thread smaller than the metric thread specified by JIS, or the inner diameter of the receiving portion of the female thread portion is set smaller than that of a general portion.

3. 3. A union type joint according to claim 2, characterized in that the nut member has a fastening portion having an outer diameter smaller than the outer diameter of the nut body, the fastening portion has a plurality of fastening protrusions on an outer periphery thereof, and a size of a circumscribed circle of the plurality of fastening protrusions is smaller than the outer diameter of the nut body.

4. 4. The union type joint according to claim 3, characterized in that the male thread member has a fastening portion having an outer diameter smaller than an outer diameter of the male thread main body, the fastening portion has a plurality of fastening protrusions on an outer periphery thereof, and a size of a circumscribed circle of the plurality of fastening protrusions is smaller than the outer diameter of the male thread main body.

5. The nut body has a plurality of confirmation holes at predetermined intervals along the outer circumferential surface, 3. A union joint according to claim 2, wherein the confirmation hole allows the seal portion and fastening position of the seal member to be visually confirmed from the outside.

6. 2. A union joint according to claim 1, wherein said seal member comprises a metal ring on the outer periphery and an elastic packing disposed inside said metal ring.

7. 6. A union type joint according to claim 5, further comprising a locking means for locking the joint between said nut member and said male thread member.

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