Clamp joint

Abstract

To enhance mechanical strength of a clamp joint.SOLUTION: A clamp body 21 includes a single central clamp element 21a and a pair of outer clamp elements 21b and 21c rotatably connected to both ends of the central clamp element. At one end connected to the central clamp 21a of each of the pair of outer clamp elements 21b and 21c, a first connecting part 215 with a through-hole into which a hinge pin 214 is inserted is formed. At each of both ends of the central clamp element 21a, a pair of second connecting parts 216 sandwiching the first connecting part 215 of the outer clamp elements 21b and 21c, with a fixing hole H2 to which the hinge pin 214 is fixed, is formed. An upper surface part 212a of a side wall part 212 that forms a recessed groove 211 provided in the central clamp element 21a is formed from one end side of the second connecting part 216 to the other end side of the second connecting part 216 in a circumferential direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a clamp joint that crimps and joins flanges provided at the ends of a pair of pipe members together in a state where the flanges are opposed to each other. [Background technology]

[0002] A known conventional clamp joint, as shown in Patent Document 1, connects a pair of pipe members by fitting a series of unit members onto the flanges provided on each end of the pair of pipe members while the flanges face each other, and fastening the unit members at both ends with fasteners.

[0003] Specifically, as shown in Figure 6, the clamp joint is composed of three unit members, and a groove that fits over the flange portion is formed on the inner peripheral surface of each unit member. The side wall portion that forms the groove of the central unit member and the side wall portions that form the grooves of the unit members at both ends are shaped to avoid interference from the hinge pin toward the center of the shaft. For this reason, the upper surface of the side wall portion that forms the groove of the central unit member is configured to be separated from the connecting portions at both ends that have through holes formed therein for inserting the hinge pin. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-067340 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when the above-mentioned clamp joint is used in a pipe carrying, for example, flammable gas or gases harmful to the human body, even greater safety is required. However, the upper surface of the side wall portion forming the groove in the central unit member is separated from the connecting ends at both ends, making it the weakest in mechanical strength among the three unit members mentioned above. Therefore, in order to further improve the mechanical strength of the clamp joint and achieve even greater safety, it is considered to improve the mechanical strength of the central unit member.

[0006] The present invention has been made to solve the above problems, and its main object is to improve the mechanical strength of a clamp joint. [Means for solving the problem]

[0007] That is, the clamp joint according to the present invention is a clamp joint configured such that, with flange portions provided on the respective ends of a pair of pipe members facing each other, a clamp body having a recessed groove formed on its inner peripheral surface so as to extend in the circumferential direction is fitted onto the outer peripheral edges of the opposing flange portions, and the clamp body is tightened so that its inner diameter is reduced, so that inclined surfaces formed on the inner surfaces of a pair of side wall portions which form the recessed groove press against inclined surfaces formed on the back surfaces of the flange portions, and the flange portions are crimped and joined together by the axial component force generated at this time, and the clamp body comprises one central clamp element and rotatable clamp members at both ends thereof. and a pair of outer clamp elements operatively connected to the central clamp element, each of the pair of outer clamp elements having a first connecting portion formed at one end connected to the central clamp element and having an insertion hole through which a hinge pin is inserted, and a pair of second connecting portions are formed at both end portions of the central clamp element, sandwiching the first connecting portion of the outer clamp element and having a fixing hole through which the hinge pin is fixed, and upper surface portions of the pair of side wall portions provided on the central clamp element are formed circumferentially from the pair of second connecting portions on one end side to the pair of second connecting portions on the other end side.

[0008] In a clamp joint configured in this manner, the upper surface portions of the pair of side walls provided on the central clamp element are formed circumferentially from the pair of second connecting portions on one end side to the pair of second connecting portions on the other end side, thereby improving the mechanical strength of the central clamp element in the clamp joint. As a result, the mechanical strength of the entire clamp joint can be improved. In addition, the mechanical strength of the central clamp element can be improved by fixing the hinge pin in the fixing hole of the central clamp element by, for example, crimping or press-fitting. As a result, even greater safety can be achieved for the clamp joint.

[0009] In order to further improve the mechanical strength of the central clamp element in the clamp joint, it is desirable that the upper surface of the second connecting portion and the upper surface of the side wall portion are continuous in a straight line when viewed in the axial direction.

[0010] It is also preferable that the inclined surfaces are formed on the entire inner surfaces of the pair of side walls. This configuration increases the contact area with the inclined surfaces of the flanges, disperses the force that the pair of side walls forming the central clamping element receive from the inclined surfaces of the flanges, and reduces the stress applied to the pair of side walls, making the central clamping element less susceptible to damage.

[0011] The clamp joint of the present invention further includes a fastening mechanism that fastens the free ends of the pair of outer clamp elements together, and the fastening mechanism has a bolt member rotatably provided in a through hole formed in the free end of one of the outer clamp elements and a female threaded hole formed in the other outer clamp element, and it is desirable that the through hole have an elliptical shape extending radially. With this configuration, the bolt member is mounted in the through hole, which improves the mechanical strength of the entire clamp joint compared to conventional configurations in which the bolt member is mounted via a U-shaped notch. Furthermore, with conventional configurations in which the bolt member is mounted via a U-shaped notch, there is a risk that the bolt member will come off the U-shaped notch when an impact is applied, but with the present invention, the bolt member is mounted in the through hole, which eliminates this risk and improves safety.

[0012] It is desirable that the fastening mechanism has a stopper ring that prevents the bolt member from slipping out of the through hole, and is configured so that the stopper ring does not come into contact with the other outer clamp element when the free ends of the pair of outer clamp elements are tightened together. [Effects of the Invention]

[0013] According to the present invention described above, the mechanical strength of the entire clamp joint can be improved by improving the mechanical strength of the central clamp element. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a partial cross-sectional view of a connection structure according to an embodiment of the present invention. [Figure 2] 4 is a view showing the clamp joint of the embodiment in a fastened state as viewed from the axial direction. FIG. [Figure 3] FIG. 2 is a view showing the clamp joint of the embodiment in an unfolded state as viewed from the axial direction. [Figure 4] FIG. 2 is a plan view of the clamp joint of the embodiment in an unfolded state. [Figure 5] FIG. 2 is a perspective view of a central clamping element in the same embodiment. [Figure 6] FIG. 1 is a diagram showing the configuration of a conventional clamp joint. DETAILED DESCRIPTION OF THE INVENTION

[0015] <One embodiment of the present invention> An embodiment of a connection structure using a clamp joint according to the present invention will be described below with reference to the drawings. Note that, for ease of understanding, all of the drawings shown below are drawn in a schematic manner, with appropriate omissions or exaggerations. Identical components are given the same reference numerals, and their descriptions will be omitted where appropriate.

[0016] 1, the connection structure 100 of this embodiment is formed by connecting a pair of pipe members 10 with a clamp joint 20. Specifically, the connection structure 100 includes the clamp joint 20 that connects the pair of pipe members 10 in an opposing state, and an annular gasket 30 that is interposed between the pair of pipe members 10, and is a structure that connects the pair of pipe members 10 in an airtight manner.

[0017] The pipe member 10 has a pipe body 11 and a flange portion 12 provided at the end of the pipe body 11. An annular protrusion 13 is formed on the tip surface of the flange portion 12. In addition, an inclined surface 14 whose diameter increases toward the tip is formed on the back surface opposite the opposing surface (tip surface) of the flange portion 12. Furthermore, a step portion 15 whose diameter is reduced is formed on the outer circumferential surface of the flange portion 12.

[0018] The clamp joint 20 is fitted onto the opposing flange portions 12 to tightly fasten them together. Specifically, as shown in Figures 1 to 4, the clamp joint 20 has a clamp body 21 having a recessed groove 211 formed on its inner peripheral surface so as to extend in the circumferential direction, and a fastening mechanism 22 that tightens the clamp body 21 so as to reduce its inner diameter.

[0019] The clamp body 21 has a series of clamp elements 21a-21c in which adjacent ones are rotatably connected to each other. Specifically, the clamp body 21 has one central clamp element 21a and a pair of outer clamp elements 21b, 21c rotatably connected to both ends of the central clamp element 21a. Each of the clamp elements 21a-21c is made of stainless steel, such as SUS630 or SUS316.

[0020] 1 and 4, a circumferentially extending groove 211 is formed on the inner peripheral surface of each of the clamp elements 21a to 21c. The groove 211 has a width that allows it to fit onto the outer peripheral edges of a pair of opposing flange portions 12. An inclined surface 213 corresponding to the inclined surface 14 of the flange portions 12 is formed on the inner surface of a pair of side wall portions 212 that form the groove 211. The groove 211 of each of the clamp elements 21a to 21c has a depth that allows the bottom surface of the groove 211 to not come into contact with the outer peripheral surface of the flange portions 12 when the inclined surface 213 of the side wall portions 212 is in contact with the inclined surface 14 of the flange portions 12.

[0021] These clamp elements 21a to 21c are rotatably connected by a hinge pin 214. The hinge pin 214 is preferably made of stainless steel such as SUS630, SUS316, or SUS304, and is preferably made of a material having strength equal to or greater than that of the material of each of the clamp elements 21a to 21c.

[0022] As shown in FIG. 4, a first connecting portion 215 having an insertion hole H1 through which the hinge pin 214 is inserted is formed at one end of each of the pair of outer clamp elements 21b, 21c that is connected to the central clamp element 21a.

[0023] The first connecting portion 215 is configured by a protrusion that protrudes toward the central clamp element 21a at one end of the outer clamp elements 21b, 21c. The width (axial dimension) of the protrusion is smaller than the distance between the pair of side wall portions 212 that form the recessed groove 211 (the width of the bottom surface of the recessed groove 211) (see FIG. 4).

[0024] Furthermore, a pair of second connecting portions 216 are formed at both ends of the central clamp element 21a, sandwiching the first connecting portions 215 of the outer clamp elements 21b and 21c and having fixing holes H2 to which the hinge pins 214 are fixed. The hinge pins 214 are fixed in the fixing holes H2 by caulking, press-fitting, or the like.

[0025] The pair of second connecting portions 216 sandwich the convex portion, which is the first connecting portion 215, from both sides in the axial direction, with a small gap between them. Recesses into which the convex portions, which are the first connecting portions 215, fit with a small gap between them, are formed at each end of the central clamp element 21a, and the wall portions along the axial direction that form these recesses serve as the second connecting portions 216. The pair of second connecting portions 216 are located circumferentially on extensions of the pair of side wall portions 212 that form the recessed groove 211 (see FIG. 4).

[0026] 2 to 5, the upper surface portions 212a of the pair of side wall portions 212 provided on the central clamp element 21a are formed in the circumferential direction from the pair of second connecting portions 216 on one end side to the pair of second connecting portions 216 on the other end side. In other words, the side wall portions 212 are formed so that the upper surface portions 212a of the side wall portions 212 are connected to both the second connecting portions 216 on one end side and the second connecting portions 216 on the other end side. In this embodiment, the upper surface portions 216a of the second connecting portions 216 and the upper surface portions 212a of the side wall portions 212 are linearly continuous when viewed from the axial direction. In addition, an inclined surface 213 corresponding to the inclined surface 14 of the flange portion 12 is formed on the entire inner surface of the pair of side wall portions 212 of the central clamp element 21a.

[0027] Furthermore, in terms of the relationship between the central clamp element 21a and the outer clamp elements 21b and 21c, a shape that avoids interference between the side wall portion 212 of the central clamp element 21a and the side wall portions of the outer clamp elements 21b and 21c is different from conventional shapes. In this embodiment, the gap formed between the side wall portion 212 of the central clamp element 21a and the side wall portions of the outer clamp elements 21b and 21c does not extend from the hinge pin 214 toward the axial center, but extends in a direction perpendicular to the radial direction from the axial center (the left-right direction in FIG. 2, which is the arrangement direction of the two hinge pins 214).

[0028] The fastening mechanism 22 fastens the free ends of the pair of outer clamp elements 21b, 21c together. Specifically, as shown in FIGS. 1 to 4, the fastening mechanism 22 has a bolt member 221 rotatably provided in a through hole H3 formed in the free end of one of the outer clamp elements 21b, and a female screw hole 222 formed in the free end of the other outer clamp element 21c. By threading the bolt member 221 into the female screw hole 222, the pair of outer clamp elements 21b, 21c are connected and the inner diameter of the clamp body 21 can be expanded or contracted. The bolt member 221 is made of stainless steel, such as SUS304 or SUS316.

[0029] 4, the through hole H3 formed in the free end of one of the outer clamp elements 21b has an elliptical shape extending along the radial direction. This elliptical through hole H3 is configured to absorb any inclination of the bolt member 221 relative to one of the outer clamp elements 21b when the bolt member 221 is screwed into the female screw hole 222. In addition, a stopper ring 223 prevents the bolt member 221 from coming out of the through hole H3.

[0030] Furthermore, when the free ends of the pair of outer clamp elements 21b, 21c are fastened together, the stopper ring 223 does not come into contact with the other outer clamp element 21c (see FIG. 2). Specifically, the thickness of the stopper ring 223 is smaller than the dimension of the gap formed between the free ends of the pair of outer clamp elements 21b, 21c when these free ends are fastened together. This configuration ensures a sufficient tightening margin for the bolt member 221, making it possible to manage the torque of the bolt member 221.

[0031] Next, a method for connecting a pair of pipe members 10 using the clamp joint 20 of this embodiment will be briefly described. The flange portions 12 of a pair of pipe members 10 are opposed to each other with the gasket 30 sandwiched therebetween. In this state, the clamp body 21 is attached so as to surround the pair of flange portions 12. At this time, the recessed grooves 211 of each of the clamp elements 21a to 21c are fitted onto the outer peripheral edges of the pair of flange portions 12. Then, the bolt members 221 are threaded into the female threaded holes 222 to fasten the free ends of the pair of outer clamp elements 21b, 21c together. This reduces the inner diameter of the clamp body 21, causing the inclined surfaces 213 of each of the clamp elements 21a to 21c to press against the inclined surfaces 14 of the flange portions 12, and the axial component force generated at this time crimps the flange portions 12 together.

[0032] <Effects of this embodiment> In the clamp joint 20 of this embodiment configured as described above, the upper surface portions 212a of the pair of side wall portions 212 provided on the central clamp element 21a are formed circumferentially from the pair of second connecting portions 216 on one end side to the pair of second connecting portions 216 on the other end side, thereby improving the mechanical strength of the central clamp element 21a in the clamp joint 20. As a result, the mechanical strength of the entire clamp joint 20 can be improved. In addition, the mechanical strength of the central clamp element 21a can be improved by fixing the hinge pin 214 in the fixing hole of the central clamp element 21a by, for example, crimping or press-fitting. As a result, even greater safety can be achieved for the clamp joint 20.

[0033] <Other embodiments> The present invention is not limited to the above-described embodiment.

[0034] For example, in the above embodiment, the inclined surface 213 was formed on the entire inner surface of the side wall portion 212 of the central clamp element 21a, but the inclined surface 213 may be formed on only a portion of the inner surface of the side wall portion 212 of the central clamp element 21a.

[0035] Furthermore, in the above embodiment, when viewed from the axial direction, the upper surface portion 216a of the second connecting portion 216 and the upper surface portion 212a of the side wall portion 212 are continuous in a straight line, but as long as the upper surface portion 212a of the side wall portion 212 is configured to be continuous with the second connecting portion 216, these upper surface portions 212a, 216a do not have to be continuous in a straight line.

[0036] Furthermore, the fastening mechanism 22 may be configured to screw the bolt member 221 into the female threaded hole 222 formed in the outer clamp element 21c, or may be configured to form a through hole in the free end of the other outer clamp element 21c through which the bolt member 221 is inserted, and to screw a nut member onto the bolt member 221 extending from the through hole.

[0037] Furthermore, in order to further improve safety in environments where loosening of the bolt member 221 is a concern, a nut may be threaded onto the tip of the bolt member 221 to form a double nut structure, or a nut may be attached instead of the stopper ring 223 to form a double nut structure.

[0038] Furthermore, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications are possible without departing from the spirit of the present invention. [Explanation of symbols]

[0039] 10...Pipe member 12 Flange part 20 Clamp joint 211 Groove 21 Clamp body 21a Central clamping element 21b One outer clamping element 21c...other outer clamping element 212 Side wall 212a... Upper surface of side wall 213...Slope 214 Hinge pin 215...1st connection part H1: Insertion hole 216...Second connection part H2...Fixing hole 216a... Upper surface of second connecting portion 22...Fascinating mechanism H3...Through hole 221 Bolt member 222 Female thread hole 40 Stopper ring

Claims

1. A clamp joint configured such that, with flange portions provided on the respective ends of a pair of pipe members facing each other, a clamp body having a groove formed on its inner peripheral surface so as to extend in the circumferential direction is fitted onto the outer peripheral edges of the facing flange portions, and the clamp body is tightened so as to reduce its inner diameter, so that inclined surfaces formed on the inner surfaces of a pair of side wall portions which form the groove press against inclined surfaces formed on the back surfaces of the flange portions, and the flange portions are crimped and joined together by the axial component force generated at this time, The clamp body has a central clamp element and a pair of outer clamp elements rotatably connected to opposite ends thereof; a first connecting portion having an insertion hole through which a hinge pin is inserted is formed at one end of each of the pair of outer clamp elements connected to the central clamp element; a pair of second connecting portions are formed at both ends of the central clamp element, sandwiching the first connecting portion of the outer clamp element and having fixing holes formed therein into which the hinge pins are fixed; A clamp joint, wherein the upper surface portions of the pair of side wall portions provided on the central clamp element are formed circumferentially from the pair of second connecting portions on one end side to the pair of second connecting portions on the other end side.

2. 2. The clamp joint according to claim 1, wherein an upper surface of the second connecting portion and an upper surface of the side wall portion are linearly continuous when viewed in the axial direction.

3. 3. The clamp joint according to claim 1, wherein the inclined surfaces are formed on the entire inner surfaces of the pair of side wall portions.

4. a fastening mechanism for fastening the free ends of the pair of outer clamp elements together; The fastening mechanism includes: a bolt member rotatably provided in a through hole formed in a free end of one of the outer clamp elements; a female screw hole formed in a free end of the other outer clamp element; 3. The clamp joint according to claim 1, wherein the through hole has an elliptical shape extending in a radial direction.

5. the fastening mechanism has a stopper ring that prevents the bolt member from being removed from the through hole, 5. The clamp joint according to claim 4, wherein the stopper ring is configured not to come into contact with the other outer clamp element when the free ends of the pair of outer clamp elements are clamped together.

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