Clamp Fittings

Abstract

Improves the mechanical strength of the clamp joint. [Solution] 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, and a first connecting portion 215 having a through hole into which a hinge pin 214 is inserted is formed at one end of each of the pair of outer clamp elements 21b, 21c connected to the central clamp element 21a, and a pair of second connecting portions 216 are formed at each end of the central clamp element 21a, which sandwich the first connecting portions 215 of the outer clamp elements 21b, 21c and have a fixing hole H2 into which the hinge pin 214 is fixed, and an upper surface portion 212a of a side wall portion 212 forming a groove 211 provided in the central clamp element 21a is formed in the circumferential direction from the second connecting portion 216 on one end side to the second connecting portion 216 on the other end side.

Description

[Technical field]

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

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

[0003] Specifically, the clamp joint is composed of three unit members, as shown in Fig. 6, and a groove is formed on the inner peripheral surface of each unit member to be fitted onto the flange portion. The side wall portion forming the groove of the central unit member and the side wall portions forming the grooves of the unit members at both ends are shaped to avoid interference from the hinge pin toward the shaft center. For this reason, in the central unit member, the upper surface portion of the side wall portion forming the groove is configured to be separated from the connecting portions at both ends in which the through holes into which the hinge pins are inserted are formed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2022-067340 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, when the above clamp joint is used for a pipe through which, for example, flammable gas or gas harmful to the human body flows, even greater safety is required. However, the central unit member has a configuration in which the upper surface of the side wall portion forming the groove is separated from the connecting ends at both ends, and therefore has the weakest mechanical strength among the above three unit members. 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] Therefore, the present invention has been made to solve the above problems, and it is an object of the present invention 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 groove formed on its inner peripheral surface extending in the circumferential direction is fitted onto the outer peripheral edges of the facing flange portions, and the clamp body is tightened so that its inner diameter is reduced, whereby inclined surfaces formed on the inner surfaces of a pair of side wall portions forming the groove press inclined surfaces formed on the rear 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 elements 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 has 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 ends 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] According to the clamp joint configured in this manner, the upper surface portions of the pair of side walls provided on the central clamp element are formed in the circumferential direction from the pair of second connecting portions on one end side to the pair of second connecting portions on the other end side, so that the mechanical strength of the central clamp element in the clamp joint can be improved. 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 to 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 linearly continuous when viewed in the axial direction.

[0010] It is also preferable that the inclined surfaces are formed over the entire inner surfaces of the pair of side walls. This configuration can increase the contact area with the inclined surface of the flange, disperse the force that the pair of side walls forming the central clamping element receive from the inclined surface of the flange, and reduce the stress applied to the pair of side walls, making the central clamping element less likely to break.

[0011] The clamp joint of the present invention further includes a fastening mechanism for tightening the free ends of the pair of outer clamp elements together, the fastening mechanism having a bolt member rotatably mounted 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 oval shape extending radially. With this configuration, the bolt member is provided in the through hole, and compared to the conventional configuration in which the bolt member is provided through a U-shaped notch, the mechanical strength of the entire clamp joint can be improved. Also, in the conventional configuration in which the bolt member is provided through 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 in the present invention, the bolt member is provided in the through hole, so there is no such risk and safety can be improved.

[0012] It is desirable that the fastening mechanism has a stopper ring to prevent 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. Effect of the Invention

[0013] According to the invention described above, by increasing the mechanical strength of the central clamp element, the mechanical strength of the entire clamp joint can be increased. [Brief description 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; [Diagram 2] 4 is a view showing the clamp joint of the embodiment in a fastened state as viewed from the axial direction. FIG. [Diagram 3] 4 is a view showing the clamp joint of the embodiment in an expanded state as viewed from the axial direction. FIG. [Figure 4] FIG. 2 is a plan view of the clamp joint of the embodiment in a developed state. [Diagram 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 PREFERRED EMBODIMENTS

[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 in all of the drawings shown below, for ease of understanding, some parts are omitted or exaggerated as appropriate. The same components are given the same reference numerals and their description will be omitted as appropriate.

[0016] 1, a 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 a clamp joint 20 that connects the pair of pipe members 10 in an opposed 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 projection 13 is formed on the tip surface of the flange portion 12. An inclined surface 14, the diameter of which increases toward the tip, is formed on the back surface of the flange portion 12 opposite the opposing surface (tip surface). Furthermore, a step portion 15, the diameter of which 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 groove 211 having a width that allows the groove 211 to be fitted around the outer periphery of a pair of opposing flanges 12 is formed on the inner peripheral surface of each of the clamp elements 21a to 21c so as to extend in the circumferential direction. The groove 211 is formed on the inner surface of a pair of side walls 212 that form the groove 211, and has an inclined surface 213 that corresponds to the inclined surface 14 of the flange 12. The groove 211 of each of the clamp elements 21a to 21c has a depth such that the bottom surface of the groove 211 does not contact the outer peripheral surface of the flange 12 when the inclined surface 213 of the side walls 212 is in contact with the inclined surface 14 of the flange 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 protruding 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 walls 212 that form the groove 211 (the width of the bottom surface of the groove 211) (see FIG. 4).

[0024] Further, a pair of second connecting parts 216 are formed at both ends of the central clamp element 21a, which sandwich the first connecting parts 215 of the outer clamp elements 21b and 21c and have fixing holes H2 to which the hinge pin 214 is fixed. The hinge pin 214 is fixed in the fixing holes H2 by crimping, 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 therebetween. A recess is formed at each end of the central clamp element 21a, into which the convex portion, which is the first connecting portion 215, fits with a small gap therebetween, and the wall portion along the axial direction that forms this recess serves as the second connecting portion 216. The pair of second connecting portions 216 are located in the circumferential direction on the extension line of the pair of side wall portions 212 that form the recessed groove 211 (see FIG. 4).

[0026] As shown in Figs. 2 to 5, the upper surface portions 212a of the pair of sidewall 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. That is, the sidewall portions 212 are formed so that the upper surface portions 212a of the sidewall 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 sidewall portions 212 are linearly continuous with each other as 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 sidewall 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, 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, 21c is different from the conventional shape. 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, 21c is configured to extend along a direction perpendicular to the radial direction from the axial center (the left-right direction in FIG. 2, the arrangement direction of the two hinge pins 214) rather than extending toward the axial center from the hinge pin 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 screwing 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 the inclination of the bolt member 221 with respect 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] In addition, the stopper ring 223 is configured not to come into contact with the other outer clamp element 21c when the free ends of the pair of outer clamp elements 21b, 21c are fastened together (see FIG. 2). Specifically, the thickness of the stopper ring 223 is configured to be smaller than the dimension of the gap formed between the free ends of the pair of outer clamp elements 21b, 21c when the free ends are fastened together. With this configuration, the fastening margin of the bolt member 221 is secured, and the torque of the bolt member 221 can be managed.

[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 the 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 edge portions of the pair of flange portions 12. Then, the bolt members 221 are screwed into the female screw holes 222 to fasten the free ends of the pair of outer clamp elements 21b, 21c together. As a result, the inner diameter of the clamp body 21 is reduced, and the inclined surfaces 213 of each of the clamp elements 21a to 21c press the inclined surfaces 14 of the flange portions 12, and the flange portions 12 are crimped and joined together by the axial component force generated at this time.

[0032] <Effects of this embodiment> According to the clamp joint 20 of the present 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 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, so that the mechanical strength of the central clamp element 21a in the clamp joint 20 can be improved. 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 to the fixing hole of the central clamp element 21a by, for example, crimping or press-fitting. As a result, the clamp joint 20 can be made even safer.

[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] In addition, 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 were 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 a 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 screwed 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 and scope of the present invention. [Explanation of symbols]

[0039] 10...Pipe member 12 Flange section 20 ···Clamp joint 211 ... groove 21 Clamp body 21a Central clamping element 21b... One outer clamp element 21c Other outer clamp element 212 Side wall portion 212a...Top surface of side wall 213...Slope surface 214 Hinge pin 215...1st connection part H1: Insertion hole 216...Second connection part H2...Fixing hole 216a...Top 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 extending in the circumferential direction is fitted onto the outer peripheral edges of the facing flange portions, and the clamp body is tightened so that its inner diameter is reduced, whereby 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 rear 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 includes 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 that is connected to the central clamp element, A pair of second connecting portions is formed at both ends of the central clamp element, the second connecting portions sandwiching the first connecting portions of the outer clamp elements and each having a fixing hole in which the hinge pin is fixed, The upper surface portions of the pair of side wall portions provided on the central clamp element are formed in a circumferential direction from the pair of second connecting portions on one end side to the pair of second connecting portions on the other end side, 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 portion of one of the outer clamp elements; a female threaded hole formed in a free end of the other outer clamp element; a stopper ring that prevents the bolt member from being removed from the through hole, The through hole has an elliptical shape extending along a radial direction, A clamp joint 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 clamped together.

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 over the entire inner surfaces of the pair of side wall portions.

Images