Pipe connecting structure
The pipe connection structure addresses the sealing performance issue by using a clamp with recesses and guide portions to enhance the fit and alignment of bulging and expanded diameter portions, improving the gasket's sealing effectiveness.
Patent Information
- Application Number
- JP2024027382
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-02-27
- Publication Date
- 2025-09-08
- Estimated Expiration
- 2044-02-27
Smart Images
Figure 2025130294000001_ABST
Abstract
Description
[Technical Field]
[0001] The present disclosure relates to a pipe connection structure. [Background technology]
[0002] For example, Patent Document 1 discloses a structure in which an end of a first pipe and an end of a second pipe are connected by a clamp. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] Japanese Patent Application Publication No. 5-33890 Summary of the Invention [Problem to be solved by the invention]
[0004] In the structure described in Patent Document 1, the end of the first pipe has a bulging portion that bulges outward in the radial direction and extends in the circumferential direction. The end of the second pipe has an enlarged diameter portion that expands in diameter toward the opening of the end. The ends of the first and second pipes are connected to each other by a clamp, with a gasket disposed between the outer peripheral surface of the bulging portion and the inner peripheral surface of the enlarged diameter portion.
[0005] There has been a demand for improved sealing performance with gaskets for this type of structure.
[0006] One aspect of the present disclosure provides a technique for improving the sealing performance of a gasket in a pipe connection structure. [Means for solving the problem]
[0007] One aspect of the present disclosure is a pipe connection structure comprising a first pipe end, a second pipe end, a gasket, and a clamp. The first pipe end is one end of a circular tubular first pipe. The first pipe end has a bulging portion that bulges outward in the radial direction and extends in the circumferential direction. The second pipe end is one of both ends of a circular tubular second pipe that is connected to the first pipe end. The second pipe end has an expanded diameter portion that expands in diameter toward the opening of the second pipe end. The gasket is disposed between the outer peripheral surface of the bulging portion and the inner peripheral surface of the expanded diameter portion. The clamp is configured to press the outer peripheral surface of the bulging portion and the outer peripheral surface of the expanded diameter portion in a direction in which the bulging portion and the expanded diameter portion approach each other. The clamp has at least one recess and at least one guide portion. The at least one recess is a concave portion configured to allow the bulging portion and the expanded diameter portion to be fitted inside. The at least one guide portion is configured to guide the bulging portion and the enlarged diameter portion toward the back side of the at least one recessed portion.
[0008] With this configuration, the sealing performance of the gasket can be improved in the pipe connection structure.
[0009] In one aspect of the present disclosure, the clamp may have a first body portion, a second body portion, a connecting portion, a first flange portion, and a second flange portion. The first body portion is configured to cover a partial circumferential region of the bulging portion and the expanded diameter portion from the outer circumferential side. The first body portion is arc-shaped. The second body portion is configured to cover another partial circumferential region of the bulging portion and the expanded diameter portion from the outer circumferential side. The second body portion is arc-shaped. The connecting portion circumferentially connects the first body portion and the second body portion. The first flange portion extends radially outward from an end of the first body portion opposite to the connecting portion side. The second flange portion extends radially outward from an end of the second body portion opposite to the connecting portion side. The second flange portion is configured to fasten to the first flange portion. The at least one recess may include a first recess formed in an inner circumferential surface of the first body portion and a second recess formed in an inner circumferential surface of the second body portion. At least one guide portion may be formed in at least one of the first recess and the second recess.
[0010] With this configuration, the sealing performance of the gasket can be improved in the pipe connection structure.
[0011] In one aspect of the present disclosure, at least one guide portion may be formed in each of the first recess and the second recess. With this configuration, the sealing performance of the gasket can be further improved in the pipe connection structure.
[0012] In one embodiment of the present disclosure, the at least one recess may have a first opposing portion and a second opposing portion. The first opposing portion has a bulging-side opposing surface configured to face the outer peripheral surface of the bulging portion. The second opposing portion has an expanded-diameter-side opposing surface configured to face the outer peripheral surface of the expanded diameter portion. The at least one guide portion may include at least one bulging-side protrusion and at least one expanded-diameter-side protrusion. The at least one bulging-side protrusion protrudes from the bulging-side opposing surface at an end of the first opposing portion opposite the back side of the at least one recess. The at least one expanded-diameter-side protrusion protrudes from the expanded-diameter-side opposing surface at an end of the second opposing portion opposite the back side of the at least one recess.
[0013] With this configuration, the sealing performance of the gasket can be improved in the pipe connection structure.
[0014] In one embodiment of the present disclosure, at least one bulging-side protrusion may protrude further inward than the inner peripheral edge of the bulging-side opposing surface. At least one expanded-diameter protrusion may protrude further inward than the inner peripheral edge of the expanded-diameter opposing surface. This configuration can further improve the sealing performance of the gasket in the pipe connection structure.
[0015] In one embodiment of the present disclosure, the at least one recess may have a first opposing portion, a second opposing portion, and a bottom portion. The first opposing portion has a bulging-side opposing surface configured to face the outer peripheral surface of the bulging portion. The second opposing portion has an expanded-diameter-side opposing surface configured to face the outer peripheral surface of the expanded diameter portion. The bottom portion connects the first opposing portion and the second opposing portion and forms the bottom surface of the at least one recess. The at least one guide portion may include an opening that forms an opening in the bottom portion extending in the circumferential direction.
[0016] With this configuration, the sealing performance of the gasket can be improved in the pipe connection structure. [Brief explanation of the drawings]
[0017] [Figure 1] FIG. 1 is a perspective view of a pipe connection structure according to a first embodiment. [Figure 2] FIG. 2 is a top view of the pipe connection structure of the first embodiment. [Figure 3] FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 2. [Figure 4] FIG. 1 is a front view of a pipe connection structure according to a first embodiment. [Figure 5] FIG. 5 is a cross-sectional view of FIG. 4 . [Figure 6] FIG. 6 is a partially enlarged view of FIG. 5. [Figure 7] 5. FIG. 7 is an enlarged view of a part of FIG. 5 different from FIG. [Figure 8] FIG. 2 is a left side view of the pipe connection structure of the first embodiment. [Figure 9] FIG. 2 is a perspective view of the clamp of the first embodiment. [Figure 10] 1 is a view of a clamp according to a first embodiment as viewed from one axial side thereof. [Figure 11] 4 is a view of the clamp of the first embodiment as seen from the other axial side. FIG. [Figure 12] 12 is a cross-sectional view taken along the line XII-XII of FIG. 10. [Figure 13] 4 is a cross-sectional view for explaining the operation of the pipe connection structure of the first embodiment. FIG. [Figure 14]FIG. 10 is a perspective view of a pipe connection structure according to a second embodiment. [Figure 15] FIG. 10 is a front view of the pipe connection structure of the second embodiment. [Figure 16] 16 is a cross-sectional view taken along line XVI-XVI of FIG. 15. [Figure 17] FIG. 17 is a partially enlarged view of FIG. [Figure 18] 17 is a partially enlarged view of FIG. 16, different from FIG. 17. FIG. [Figure 19] FIG. 10 is a left side view of the pipe connection structure of the second embodiment. [Figure 20] FIG. 10 is a perspective view of a clamp according to a second embodiment. [Figure 21] FIG. 10 is a view of a clamp according to a second embodiment as viewed from one axial side. [Figure 22] 22-XXII cross-sectional view of FIG. 21. [Figure 23] FIG. 10 is a cross-sectional view illustrating the operation of the pipe connection structure of the second embodiment. DETAILED DESCRIPTION OF THE INVENTION
[0018] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings.
[0019] [1. First embodiment] [1-1.Configuration] The pipe connection structure S1 (hereinafter simply referred to as the connection structure S1) shown in Figures 1 to 8 is a structure that connects a first pipe 1 and a second pipe 2. The first pipe 1 and the second pipe 2 are circular tubular. The central axes of the first pipe 1 and the second pipe 2 may be straight or may be partially curved. The first pipe 1 and the second pipe 2 of this embodiment have a cross-sectional shape perpendicular to their central axes that is perfectly circular. The first pipe 1 and the second pipe 2 are made of metal. The first pipe 1 and the second pipe 2 form a flow path for a fluid. A specific example of the fluid is exhaust gas from an internal combustion engine of a vehicle. That is, the connection structure S1 is applied, for example, to the exhaust system of a vehicle.
[0020] As shown in FIG. 3, the connection structure S1 includes a first pipe end portion 11, a second pipe end portion 21, a gasket 3, a clamp 4, and a fastening member 5.
[0021] The first pipe end 11 is one end in the axial direction of the first pipe 1. The central axis of the first pipe end 11 is linear. The first pipe end 11 has a constant diameter portion 111 and a bulging portion 112.
[0022] The constant diameter portion 111 is a cylindrical portion that forms the opening 11a of the first pipe end 11. The outer and inner diameters of the constant diameter portion 111 are constant in the axial direction. As will be described later, the constant diameter portion 111 is inserted into the constant diameter portion 211 of the second pipe end 21. At this time, as shown in FIG. 5 , a notch 1111 is formed in the constant diameter portion 111 of the first pipe end 11 at a portion corresponding to the deformed portion 2111 so that the constant diameter portion 111 of the first pipe end 11 does not interfere with the deformed portion 2111 of the constant diameter portion 211 of the second pipe end 21.
[0023] The bulging portion 112 is a portion that continues from the constant diameter portion 111 on the side opposite to the opening 11a side. The bulging portion 112 extends in the circumferential direction while bulging outward in the radial direction. Specifically, the bulging portion 112 extends around the entire circumferential direction while bulging outward in the radial direction. In other words, the bulging portion 112 is cylindrical.
[0024] As shown in FIG. 6, the bulging portion 112 has a first wall portion 1121, a second wall portion 1122, and a top portion 1123.
[0025] The first wall portion 1121 and the second wall portion 1122 are plate-shaped portions that face each other in the axial direction of the bulging portion 112. The first wall portion 1121 and the second wall portion 1122 face each other across an imaginary plane that is perpendicular to the axial direction of the bulging portion 112 and passes through the top portion 1123. The distance between the first wall portion 1121 and the second wall portion 1122 becomes narrower toward the radially outer side.
[0026] The apex 1123 is a plate-like portion that connects the first wall portion 1121 and the second wall portion 1122. The apex 1123 is continuous with the constant diameter portion 111 via the second wall portion 1122. That is, the side of the second wall portion 1122 opposite to the apex 1123 side is continuous with the constant diameter portion 111. The apex 1123 corresponds to the radially outermost portion of the bulging portion 112. The first wall portion 1121, the second wall portion 1122, and the apex 1123 form a V-shaped cross section of the bulging portion 112 along the axial direction of the bulging portion 112.
[0027] As shown in Figure 3, the second pipe end 21 is the end of the second pipe 2 in the axial direction that is connected to the first pipe end 11. The second pipe end 21 is connected to the first pipe end 11 by a clamp 4 and a fastening member 5. The central axis of the second pipe end 21 is linear. The second pipe end 21 has a constant diameter portion 211, an expanded diameter portion 212, and a reduced diameter portion 213.
[0028] The constant diameter portion 211 is a cylindrical portion. As shown in FIGS. 4 and 5, the outer and inner diameters of the constant diameter portion 211 are constant in the axial direction except for the region where the deformed portion 2111 is formed. The deformed portion 2111 is a portion where a portion of the constant diameter portion 211 in the circumferential direction is recessed inward. The inner diameter of the constant diameter portion 211 of the second pipe end 21 is the same as or slightly larger than the outer diameter of the constant diameter portion 111 of the first pipe end 11 except for the region where the deformed portion 2111 is formed. The constant diameter portion 211 of the second pipe end 21 is configured so that the constant diameter portion 111 of the first pipe end 11 can be inserted inside.
[0029] The expanded diameter portion 212 is a cylindrical portion that continues to the constant diameter portion 211 on the opening 21a side of the second pipe end 21. The expanded diameter portion 212 expands in diameter toward the opening 21a of the second pipe end 21. Hereinafter, the end of the expanded diameter portion 212 on the opening 21a side (i.e., the side opposite to the constant diameter portion 211 side) will be referred to as the tip portion 2121 of the expanded diameter portion 212. The maximum outer diameter of the expanded diameter portion 212 is larger than the maximum outer diameter of the bulging portion 112.
[0030] The reduced diameter portion 213 is a cylindrical portion that continues from the expanded diameter portion 212 toward the opening 21a of the second pipe end 21. In other words, the reduced diameter portion 213 is a cylindrical portion that continues from the tip portion 2121 of the expanded diameter portion 212. The reduced diameter portion 213 forms the opening 21a of the second pipe end 21. The minimum outer diameter of the reduced diameter portion 213 is smaller than the maximum outer diameter of the expanded portion 112. In addition, the minimum outer diameter of the reduced diameter portion 213 is larger than the outer diameter of the constant diameter portion 211. When the constant diameter portion 111 of the first pipe end 11 is inserted into the constant diameter portion 211 of the second pipe end 21, the reduced diameter portion 213 is configured to be able to come into contact with the expanded portion 112.
[0031] The first pipe end 11 and the second pipe end 21 are connected to each other by the clamp 4 and the fastening member 5 with the constant diameter portion 111 of the first pipe end 11 inserted into the constant diameter portion 211 of the second pipe end 21. As shown in FIG. 6 , when the first pipe end 11 and the second pipe end 21 are connected, the outer circumferential surface 112a of the bulging portion 112 and the inner circumferential surface 212a of the expanded diameter portion 212 face each other. More specifically, the outer circumferential surface 1122a of the second wall portion 1122 of the bulging portion 112 face each other with the inner circumferential surface 212a of the expanded diameter portion 212. The outer circumferential surface 1122a of the second wall portion 1122 is included in the outer circumferential surface 112a of the bulging portion 112. Furthermore, when the first pipe end 11 and the second pipe end 21 are connected, the end of the opening 21a side of the reduced diameter portion 213 of the second pipe end 21 is in contact with the outer surface 1122a of the second wall portion 1122 of the first pipe end 11.
[0032] The gasket 3 is an elastic cylindrical member. The gasket 3 is impermeable to fluids. The fluid here refers to the fluid flowing through the first pipe 1 and the second pipe 2. For example, when the first pipe 1 and the second pipe 2 form a flow path for exhaust gas, the gasket 3 is impermeable to exhaust gases.
[0033] As shown in FIGS. 5 to 7, when the first pipe end 11 and the second pipe end 21 are connected to each other, the gasket 3 is disposed between the outer peripheral surface 112a of the bulging portion 112 and the inner peripheral surface 212a of the expanded diameter portion 212. More specifically, the gasket 3 is disposed between the outer peripheral surface 1122a of the second wall portion 1122 of the bulging portion 112 and the inner peripheral surface 212a of the expanded diameter portion 212. The thickness of the gasket 3 is greater than the distance between the outer peripheral surface 112a of the bulging portion 112 (more specifically, the outer peripheral surface 1122a of the second wall portion 1122) and the inner peripheral surface 212a of the expanded diameter portion 212 when the first pipe end 11 and the second pipe end 21 are connected to each other. That is, the gasket 3 is disposed between the outer peripheral surface 112a of the bulging portion 112 and the inner peripheral surface 212a of the expanded diameter portion 212 in a state compressed by them. The gasket 3 closes (seals) the gap between them.
[0034] 9, the clamp 4 is a generally C-shaped member. The clamp 4 is made of metal. The clamp 4 has a first main body portion 41, a second main body portion 42, a connecting portion 43, a first flange portion 44, and a second flange portion 45.
[0035] 5 and 8, the first main body portion 41 is an arc-shaped portion configured to cover a partial circumferential region of the bulging portion 112 and the expanded diameter portion 212 from the outer periphery. The second main body portion 42 is an arc-shaped portion configured to cover another partial circumferential region of the bulging portion 112 and the expanded diameter portion 212 from the outer periphery. The first main body portion 41 and the second main body portion 42 are arranged such that the directions in which the arc-shaped bulges of the first main body portion 41 and the second main body portion 42 bulge away from each other. Because the first main body portion 41 and the second main body portion 42 have the same configuration, the first main body portion 41 will be described in detail below.
[0036] As shown in FIG. 9, the first main body portion 41 has a recess 411, a first plate-shaped portion 412, a second plate-shaped portion 413, and a plurality of (six in this embodiment) protrusions 414A to 414F.
[0037] The recess 411 is a recessed portion formed on the inner circumferential surface 41a of the first main body portion 41. In other words, the recess 411 is a portion where the inner circumferential surface 41a of the first main body portion 41 is recessed radially outward. The recess 411 extends in the circumferential direction. Specifically, as shown in FIG. 12 , the recess 411 extends from one end to the other end in the circumferential direction of the first main body portion 41. The recess 411 has a first opposing portion 4111, a second opposing portion 4112, and a bottom portion 4113.
[0038] As shown in FIG. 6 , the first opposing portion 4111 forms the first side surface 411a of the recess 411. The second opposing portion 4112 forms the second side surface 411b of the recess 411. The first side surface 411a and the second side surface 411b face each other in the axial direction of the first main body portion 41. The first side surface 411a and the second side surface 411b face each other across an imaginary plane that is perpendicular to the axial direction of the first main body portion 41 and passes through the bottom portion 4113. The axial direction of the first main body portion 41 is parallel to the central axis of an imaginary circle that includes the arc-shaped first main body portion 41. The axial direction of the first main body portion 41 corresponds to the left-right direction in FIG. 6 . In this embodiment, the first opposing portion 4111 and the second opposing portion 4112 are plate-shaped. The distance between the first opposing portion 4111 and the second opposing portion 4112 becomes narrower toward the back side of the recess 411 (i.e., radially outward). The distance between the first opposing portion 4111 and the second opposing portion 4112 can also be said to be the distance between the first side surface 411a and the second side surface 411b.
[0039] The bottom portion 4113 is a portion that connects the first opposing portion 4111 and the second opposing portion 4112. The bottom portion 4113 in this embodiment is plate-shaped. The bottom portion 4113 forms the bottom surface 411c of the recessed portion 411. The bottom portion 4113 corresponds to the portion of the first main body portion 41 that is located outermost in the radial direction.
[0040] The dimension M1 of the opening surface of the recess 411 is larger than the dimension M2 from the apex 1123 of the bulging portion 112 to the tip 2121 of the expanded diameter portion 212. The dimension M1 of the opening surface of the recess 411, more specifically, refers to the dimension M1 of the opening surface of the recess 411 along the axial direction of the first main body portion 41. The dimension M2 from the apex 1123 of the bulging portion 112 to the tip 2121 of the expanded diameter portion 212, more specifically, refers to the dimension M2 from the outer circumferential edge of the apex 1123 of the bulging portion 112 to the outer circumferential edge of the tip 2121 of the expanded diameter portion 212 along the axial direction of the first pipe end portion 11 when the first pipe end portion 11 and the second pipe end portion 21 are connected to each other. The outer circumferential edge refers to the radially outer edge. The same applies below. The axial direction of the first pipe end portion 11 corresponds to the left-right direction in FIG. 6.
[0041] Since the dimension M1 is larger than the dimension M2, at least a portion in the circumferential direction of the top 1123 of the bulging portion 112 and a portion in the circumferential direction of the tip 2121 of the expanded diameter portion 212 can be fitted inside the recess 411. In other words, the recess 411 is configured so that the bulging portion 112 and the expanded diameter portion 212 can be fitted inside.
[0042] When the bulging portion 112 and the expanded diameter portion 212 are fitted inside the recess 411, the recess 411 presses the outer peripheral surface 112a of the bulging portion 112 (more specifically, the outer peripheral surface 1121a of the first wall portion 1121) and the outer peripheral surface 212b of the expanded diameter portion 212 in a direction in which the bulging portion 112 and the expanded diameter portion 212 approach each other. That is, the recess 411 is configured to press the outer peripheral surface 112a of the bulging portion 112 (more specifically, the outer peripheral surface 1121a of the first wall portion 1121) and the outer peripheral surface 212b of the expanded diameter portion 212 in a direction in which the bulging portion 112 and the expanded diameter portion 212 approach each other. The outer peripheral surface 1121a of the first wall portion 1121 is included in the outer peripheral surface 112a of the bulging portion 112. Furthermore, when the bulging portion 112 and the expanded diameter portion 212 are fitted inside the recess 411, the first side surface 411a of the recess 411 faces the outer circumferential surface 112a of the bulging portion 112 (more specifically, the outer circumferential surface 1121a of the first wall portion 1121). That is, the first side surface 411a of the recess 411 is configured to face the outer circumferential surface 112a of the bulging portion 112 (more specifically, the outer circumferential surface 1121a of the first wall portion 1121). Furthermore, when the bulging portion 112 and the expanded diameter portion 212 are fitted inside the recess 411, the second side surface 411b of the recess 411 faces the outer circumferential surface 212b of the expanded diameter portion 212. That is, the second side surface 411b of the recess 411 is configured to face the outer circumferential surface 212b of the expanded diameter portion 212.
[0043] The first plate-shaped portion 412 and the second plate-shaped portion 413 are portions that are respectively continuous with one side and the other side of the recessed portion 411 in the axial direction of the first main body portion 41. The first plate-shaped portion 412 is continuous with the first opposing portion 4111 of the recessed portion 411. The second plate-shaped portion 413 is continuous with the second opposing portion 4112 of the recessed portion 411. The first plate-shaped portion 412 and the second plate-shaped portion 413 extend in directions away from each other, sandwiching the recessed portion 411 therebetween.
[0044] As shown in FIG. 9, the plurality of protruding portions 414A to 414F are portions that protrude from the recessed portion 411 toward the inner periphery side.
[0045] Specifically, as shown in FIG. 12, among the multiple protrusions 414A to 414F, the first to third protrusions 414A to 414C protrude from the first side surface 411a at an end of the first opposing portion 4111 opposite the deep side of the recess 411 (i.e., the bottom 4113 side). As shown in FIG. 10, the first to third protrusions 414A to 414C protrude further inward than the first opposing portion 4111 when viewed in the axial direction of the first main body portion 41. In other words, the first to third protrusions 414A to 414C protrude further inward than the inner peripheral edge of the first opposing portion 4111. The inner peripheral edge refers to the radially inner edge. The same applies below. Note that FIG. 10 shows a see-through view of the first plate-shaped portion 412 of the first main body portion 41 and a first plate-shaped portion 422 (described later) of the second main body portion 42.
[0046] 10 and 12, the first to third protrusions 414A to 414C have a generally oval shape extending in the circumferential direction of the first main body portion 41. The first to third protrusions 414A to 414C are arranged in this order in the circumferential direction of the first main body portion 41. In the circumferential direction of the first main body portion 41, the second protrusion 414B is arranged in a middle portion of the first opposing portion 4111. The middle portion of the first opposing portion 4111 is a portion that includes the midpoint of an imaginary arc extending from one end to the other end of the first opposing portion 4111. In the circumferential direction of the first main body portion 41, the distance between the second protrusion 414B and the first protrusion 414A is equal to the distance between the second protrusion 414B and the third protrusion 414C.
[0047] As shown in Fig. 12, of the multiple protrusions 414A to 414F, the fourth to sixth protrusions 414D to 414F protrude from the second side surface 411b at an end of the second opposing portion 4112 opposite to the back side of the recess 411. As shown in Fig. 11, the fourth to sixth protrusions 414D to 414F protrude further inward than the second opposing portion 4112 when viewed in the axial direction of the first main body portion 41. In other words, the fourth to sixth protrusions 414D to 414F protrude further inward than the inner peripheral edge of the second opposing portion 4112. Note that Fig. 11 shows a see-through view of the second plate-shaped portion 413 of the first main body portion 41 and a second plate-shaped portion 423 (described later) of the second main body portion 42.
[0048] 11 and 12, the fourth to sixth protruding portions 414D to 414F are formed in a shape symmetrical to the first to third protruding portions 414A to 414C across the bottom portion 4113. That is, the fourth to sixth protruding portions 414D to 414F have a generally oval shape extending in the circumferential direction of the first main body portion 41.
[0049] The fourth to sixth protrusions 414D to 414F are arranged in this order in the circumferential direction of the first main body portion 41. The fourth to sixth protrusions 414D to 414F are arranged symmetrically to the first to third protrusions 414A to 414C with the bottom portion 4113 in between. That is, the fourth to sixth protrusions 414D to 414F are arranged in positions overlapping the first to third protrusions 414A to 414C in the axial direction of the first main body portion 41. In the circumferential direction of the first main body portion 41, the fifth protrusion 414E is arranged in a middle portion of the second opposing portion 4112. The middle portion of the second opposing portion 4112 is a portion including a midpoint of an imaginary arc extending from one end to the other end of the second opposing portion 4112. In the circumferential direction of the first main body portion 41, the distance between the fifth protrusion 414E and the fourth protrusion 414D is equal to the distance between the fifth protrusion 414E and the sixth protrusion 414F.
[0050] As described above, the second main body portion 42 has the same configuration as the first main body portion 41, and therefore a detailed description thereof will be omitted. As shown in Figures 5, 7 to 11, etc., the recessed portion 421, the first plate-shaped portion 422, the second plate-shaped portion 423, and the first to sixth protruding portions 424A to 424F of the second main body portion 42 correspond to the recessed portion 411, the first plate-shaped portion 412, the second plate-shaped portion 413, and the first to sixth protruding portions 414A to 414F of the first main body portion 41, respectively. The first opposing portion 4211, the second opposing portion 4212, the bottom 4213, the first side surface 421a, the second side surface 421b, and the bottom surface 421c of the recess 421 of the second main body portion 42 correspond to the first opposing portion 4111, the second opposing portion 4112, the bottom 4113, the first side surface 411a, the second side surface 411b, and the bottom surface 411c of the recess 411 of the first main body portion 41. The dimension M3 of the second main body portion 42 corresponds to the dimension M1 of the first main body portion 41.
[0051] As shown in Figures 8 and 9, the connection portion 43 is a portion that connects the first body portion 41 and the second body portion 42 in the circumferential direction. The connection portion 43 connects the opposing ends of the first body portion 41 and the second body portion 42. The connection portion 43 is generally V-shaped and protrudes radially outward. The connection portion 43 is configured so that the angle of the V-shape can be changed by an external force. When the V-shape angle of the connection portion 43 increases, the distance between the first body portion 41 and the second body portion 42 increases. When the V-shape angle of the connection portion 43 decreases, the distance between the first body portion 41 and the second body portion 42 decreases.
[0052] The first flange portion 44 is a plate-like portion extending radially outward from the end of the first main body portion 41 opposite the connecting portion 43 side. The first flange portion 44 in this embodiment is generally flat. A through hole 441 is formed in the first flange portion 44, through which the fastening member 5 can be inserted. The fastening member 5 is a member configured to be able to fasten the first flange portion 44 and the second flange portion 45 together. The fastening member 5 in this embodiment is a bolt and a nut.
[0053] The second flange portion 45 is a plate-like portion extending radially outward from the end of the second main body portion 42 opposite the connecting portion 43 side. The second flange portion 45 in this embodiment is generally flat. The second flange portion 45 faces the first flange portion 44 with a gap between them. A through hole 451 is formed in the second flange portion 45, and a fastening member 5 can be inserted therethrough. The through hole 451 is formed in the second flange portion 45 at a position facing the through hole 441 of the first flange portion 44. The second flange portion 45 is configured to be fastened to the first flange portion 44 by the fastening member 5 inserted through the through holes 441, 451.
[0054] 1, 3, and 5, in the connection structure S1, the constant diameter portion 111 of the first pipe end 11 is inserted into the constant diameter portion 211 of the second pipe end 21, and a gasket 3 is disposed between the outer circumferential surface 112a of the bulging portion 112 and the inner circumferential surface 212a of the expanded diameter portion 212. In this state, a clamp 4 is disposed on the outer circumferential side of the first pipe end 11 and the second pipe end 21. Specifically, the clamp 4 is disposed on the outer circumferential side of the bulging portion 112 and the expanded diameter portion 212. The first flange portion 44 and the second flange portion 45 of the clamp 4 are fastened to each other by a fastening member 5. As a result, at least the apex 1123 of the bulging portion 112 and at least the tip portion 2121 of the expanded diameter portion 212 are fitted into the recesses 411, 421 of the clamp 4. At this time, the clamp 4 presses the outer peripheral surface 112a of the bulging portion 112 and the outer peripheral surface 212b of the expanded diameter portion 212 in a direction in which the bulging portion 112 and the expanded diameter portion 212 approach each other. In other words, the clamp 4 is configured to press the outer peripheral surface 112a of the bulging portion 112 and the outer peripheral surface 212b of the expanded diameter portion 212 in a direction in which the bulging portion 112 and the expanded diameter portion 212 approach each other.
[0055] [1-2. Effect] When the first pipe 1 and the second pipe 2 are connected, first, the constant diameter portion 111 of the first pipe end portion 11 is inserted into the constant diameter portion 211 of the second pipe end portion 21. At this time, the gasket 3 is disposed between the outer peripheral surface 112a of the bulging portion 112 (more specifically, the outer peripheral surface 1122a of the second wall portion 1122) and the inner peripheral surface 212a of the expanded diameter portion 212.
[0056] Next, the clamp 4 is placed on the outer circumferential side of the bulging portion 112 and the expanded diameter portion 212. Specifically, as shown in FIGS. 5 to 7, the clamp 4 is placed so that the recess 411 of the first main body portion 41 and the recess 421 of the second main body portion 42 face at least the apex 1123 of the bulging portion 112 and at least the tip 2121 of the expanded diameter portion 212. This results in a state in which the bulging portion 112 and the expanded diameter portion 212 are positioned between the recesses 411, 421 of the first main body portion 41 and the second main body portion 42.
[0057] 1 and 2, the fastening member 5 is inserted into the through holes 441, 451 of the clamp 4. Then, the fastening member 5 is tightened to fasten the first flange portion 44 and the second flange portion 45 together.
[0058] As the fastening member 5 is tightened, the gap between the first main body portion 41 and the second main body portion 42 gradually narrows, and as shown in FIGS. 6 and 7 , the apex 1123 of the bulging portion 112 and the tip end 2121 of the expanded diameter portion 212 enter the recesses 411, 421. Then, the recesses 411, 421 come into contact with the bulging portion 112 and the expanded diameter portion 212 from the outer periphery. As the fastening member 5 is tightened further, the gap between the first main body portion 41 and the second main body portion 42 narrows further, and the recesses 411, 421 press the outer circumferential surface 112a of the bulging portion 112 (more specifically, the outer circumferential surface 1121a of the first wall portion 1121) and the outer circumferential surface 212b of the expanded diameter portion 212 in directions in which the bulging portion 112 and the expanded diameter portion 212 approach each other.
[0059] 6, 9, and 12, the clamp 4 is provided with first to third protrusions 414A to 414C at an end of the first opposing portion 4111 of the first main body portion 41 opposite the bottom 4113 side. Fourth to sixth protrusions 414D to 414F are provided at an end of the second opposing portion 4112 of the first main body portion 41 opposite the bottom 4113 side. Furthermore, as shown in FIGS. 7 and 9, first to third protrusions 424A to 424C are provided at an end of the first opposing portion 4211 of the second main body portion 42 opposite the bottom 4213 side. Fourth to sixth protrusions 424D to 424F are provided at an end of the second opposing portion 4212 of the second main body portion 42 opposite the bottom 4213 side.
[0060] As a result, when the fastening member 5 is tightened and the gap between the first main body portion 41 and the second main body portion 42 narrows, the protruding portions 414A to 414F and 424A to 424F, which protrude inward from the recessed portions 411 and 421, are more likely to first come into contact with the outer peripheral surface 112a of the bulging portion 112 (more specifically, the outer peripheral surface 1121a of the first wall portion 1121) and the outer peripheral surface 212b of the expanded diameter portion 212. As the gap between the first main body portion 41 and the second main body portion 42 narrows, the protruding portions 414A to 414F and 424A to 424F are more likely to press the outer peripheral surface 112a of the bulging portion 112 (more specifically, the outer peripheral surface 1121a of the first wall portion 1121) and the outer peripheral surface 212b of the expanded diameter portion 212, as shown by the solid black arrows in FIG. That is, the outer peripheral surface 112a of the bulging portion 112 (more specifically, the outer peripheral surface 1121a of the first wall portion 1121) and the outer peripheral surface 212b of the expanded diameter portion 212 are pressed more toward each other by the protrusions 414A to 414F, 424A to 424F. This makes the bulging portion 112 and the expanded diameter portion 212 more likely to bend. Specifically, the bulging portion 112 is more likely to bend in a direction that reduces the angle of the first wall portion 1121 relative to the second wall portion 1122. The expanded diameter portion 212 is more likely to bend in a direction that reduces its angle relative to the reduced diameter portion 213. In other words, the expanded diameter portion 212 is more likely to bend in a direction that reduces its angle relative to the constant diameter portion 211.
[0061] As a result, the bulging portion 112 and the expanded diameter portion 212 can more easily enter the innermost recesses 411 and 421. That is, the protruding portions 414A to 414F and 424A to 424F guide the bulging portion 112 and the expanded diameter portion 212 toward the innermost recesses 411 and 421. The first to sixth protruding portions 414A to 414F of the first main body portion 41 correspond to an example of a guide portion that guides the bulging portion 112 and the expanded diameter portion 212 toward the innermost recesses 411 and 421. The first to sixth protruding portions 424A to 424F of the second main body portion 42 correspond to an example of a guide portion that guides the bulging portion 112 and the expanded diameter portion 212 toward the innermost recesses 421.
[0062] The fastening member 5 is tightened until the reduced diameter portion 213 contacts the outer peripheral surface 112a of the bulge portion 112 and the tightening torque required for the gasket 3 to provide a seal is reached. This fastens the first flange portion 44 and the second flange portion 45 to each other. The protrusions 414A-414F, 424A-424F guide the bulge portion 112 and the expanded diameter portion 212 toward the inner sides of the recesses 411, 421. Therefore, when the fastening of the first flange portion 44 and the second flange portion 45 by the fastening member 5 is completed, the bulge portion 112 and the expanded diameter portion 212 are fitted even further into the inner sides of the recesses 411, 421. In other words, the distance between the first main body portion 41 and the second main body portion 42 becomes even narrower.
[0063] By fitting the bulging portion 112 and the expanded diameter portion 212 deeper into the recesses 411, 421, as shown by the hollow arrows in Fig. 13, the outer peripheral surface 112a of the bulging portion 112 (more specifically, the outer peripheral surface 1122a of the second wall portion 1122) and the inner peripheral surface 212a of the expanded diameter portion 212 are more likely to press against the gasket 3. In other words, the surface pressure on the gasket 3 increases. Therefore, the sealing performance of the gasket 3 improves.
[0064] [1-3.Effects] According to the first embodiment described above in detail, the following effects can be obtained.
[0065] (1a) In the connecting structure S1, the clamp 4 includes recesses 411, 421. At least one protrusion 414A-414C, 424A-424C is provided on the first opposing portions 4111, 4211 of the recesses 411, 421 at the end opposite the rear side of the recesses 411, 421. At least one protrusion 414D-414F, 424D-424F is also provided on the second opposing portions 4112, 4212 of the recesses 411, 421 at the end opposite the rear side of the recesses 411, 421.
[0066] According to this configuration, the protrusions 414A to 414F, 424A to 424F make it easier to flex the bulging portion 112 and the expanded diameter portion 212. This allows the bulging portion 112 and the expanded diameter portion 212 to be fitted deeper into the recesses 411, 421. As a result, it becomes easier to press the gasket 3. This in turn improves the sealing performance of the gasket 3.
[0067] (1b) In particular, in this embodiment, the first opposing portions 4111, 4211 and the second opposing portions 4112, 4212 each have a plurality of protrusions 414A-414F, 424A-424F. With this configuration, the bulging portion 112 and the expanded diameter portion 212 can be more easily deflected than in a configuration in which the first opposing portions 4111, 4211 and the second opposing portions 4112, 4212 each have a single protrusion. This allows the bulging portion 112 and the expanded diameter portion 212 to be fitted deeper into the recesses 411, 421. This makes it even easier to press the gasket 3. This in turn further improves the sealing performance of the gasket 3.
[0068] (1c) The first to third protruding portions 414A to 414C, 424A to 424C protrude from the first side surfaces 411a, 421a to a position more inward than the inner peripheral edges of the first opposing portions 4111, 4211. The fourth to sixth protruding portions 414D to 414F, 424D to 424F protrude from the second side surfaces 411b, 421b to a position more inward than the inner peripheral edges of the second opposing portions 4112, 4212.
[0069] This configuration allows the first to third protrusions 414A to 414C, 424A to 424C to more easily come into contact with the outer peripheral surface 112a of the bulging portion 112. Furthermore, the fourth to sixth protrusions 414D to 414F, 424D to 424F to more easily come into contact with the outer peripheral surface 212b of the expanded diameter portion 212. Therefore, these protrusions 414A to 414F, 424A to 424F can more easily press the bulging portion 112 and the expanded diameter portion 212. This allows the bulging portion 112 and the expanded diameter portion 212 to be more easily deflected, allowing them to be fitted even deeper into the recesses 411, 421. As a result, the gasket 3 can be more easily pressed. Consequently, the sealing performance of the gasket 3 can be further improved.
[0070] In addition, with the above configuration, the first to third protrusions 414A to 414C, 424A to 424C protrude to positions closer to the central axes of the first pipe end 11 and the second pipe end 22 than the inner circumferential edges of the first opposing portions 4111 and 4211. The fourth to sixth protrusions 414D to 414F, 424D to 424F protrude to positions closer to the central axes of the first pipe end 11 and the second pipe end 21 than the inner circumferential edges of the second opposing portions 4112 and 4212. This makes it possible to approximate the radial length from the central axes of the first pipe end 11 and the second pipe end 21 to the first to sixth protrusions 414A to 414F to the radial length from the central axes of the first pipe end 11 and the second pipe end 21 to the gasket 3. A specific example of the length to the gasket 3 here is the length to the radial center of the gasket 3. Therefore, it is possible to easily press the gasket 3 from a position that overlaps with the gasket 3 in the axial direction. This also contributes to further improving the sealing performance of the gasket 3.
[0071] (1d) In the recesses 411, 421, the first to third protrusions 414A to 414C, 424A to 424C protruding from the first side surfaces 411a, 421a are positioned so as to overlap in the axial direction with the fourth to sixth protrusions 414D to 414F, 424D to 424F protruding from the second side surfaces 411b, 421b.
[0072] According to this configuration, the protrusions 414A to 414F, 424A to 424F can more stably press the outer peripheral surface 112a of the bulging portion 112 and the outer peripheral surface 212b of the enlarged diameter portion 212. Therefore, the effects (1a) to (1c) described above can be more easily obtained.
[0073] [1-4. Correspondence] In the first embodiment, the recess 411 corresponds to an example of a first recess. The recess 421 corresponds to an example of a second recess. The first side surfaces 411a, 421a correspond to an example of a bulging-side facing surface. The second side surfaces 411b, 421b correspond to an example of an expanded-diameter-side facing surface. The first to third protrusions 414A-414C, 424A-424C correspond to an example of a bulging-side protrusion. The fourth to sixth protrusions 414D-414E, 424D-424F correspond to an example of a expanded-diameter-side protrusion.
[0074] [2. Second Embodiment] [2-1.Configuration] The second embodiment has the same basic configuration as the first embodiment, so differences will be described below. Note that the same reference numerals as those in the first embodiment indicate the same configuration, and reference is made to the preceding description.
[0075] A pipe connection structure S2 of a second embodiment shown in Figures 14 to 19 (hereinafter simply referred to as connection structure S2) differs from the connection structure S1 of the first embodiment in that it includes a clamp 6 instead of the clamp 4 described above.
[0076] As shown in FIGS. 20 to 22, the clamp 6 of the second embodiment has substantially the same configuration as the clamp 4 of the first embodiment. However, the clamp 6 of the second embodiment has a first body portion 61 and a second body portion 62 instead of the first body portion 41 and the second body portion 42 described above. The first body portion 61 and the second body portion 62 of the second embodiment have substantially the same configuration as the first body portion 41 and the second body portion 42 of the first embodiment. Furthermore, the first body portion 61 and the second body portion 62 of the second embodiment have the same configuration as each other. For this reason, the first body portion 61 will be described in detail below.
[0077] The first main body portion 61 of the second embodiment differs from the first main body portion 41 of the first embodiment in that it has an opening 611 instead of the multiple protrusions 414A to 414F. As shown in FIG. 22, the opening 611 is a portion that forms an opening 611a in the bottom portion 4113 of the recessed portion 411. The opening 611 forms the opening 611a in at least a middle portion of the bottom portion 4113. The middle portion of the bottom portion 4113 is a portion that includes the midpoint of an imaginary arc extending from one end of the bottom portion 4113 to the other end. The opening 611a extends in the circumferential direction.
[0078] As shown in FIG. 17 , the dimension M4 of the opening surface of the opening 611 is smaller than the dimension M1 of the opening surface of the recess 411, which was described in detail in the first embodiment. Furthermore, the dimension M4 of the opening surface of the opening 611 is larger than the dimension M2 from the apex 1123 of the bulging portion 112 to the tip 2121 of the expanded diameter portion 212, which was described in detail in the first embodiment. More specifically, the dimension M4 of the opening surface of the opening 611 is the dimension M1 of the opening surface of the opening 611 along the axial direction of the first main body portion 61. The axial direction of the first main body portion 61 is parallel to the central axis of an imaginary circle that includes the arc-shaped first main body portion 61. The axial direction of the first main body portion 61 corresponds to the left-right direction in FIG. 17 .
[0079] Because the dimension M4 is larger than the dimension M2, when the bulging portion 112 and the expanded diameter portion 212 are fitted inside the recess 411, a circumferential portion of the top 1123 of the bulging portion 112 and a circumferential portion of the tip 2121 of the expanded diameter portion 212 can be inserted into the opening 611. In other words, the opening 611 is configured so that the top 1123 of the bulging portion 112 and the tip 2121 of the expanded diameter portion 212 can be inserted therein.
[0080] As described above, the second main body portion 62 has the same configuration as the first main body portion 61, and therefore a detailed description thereof will be omitted. As shown in Figures 16, 18 to 21, the opening 621 in the second main body portion 62 and the opening 621a formed thereby correspond to the opening 611 in the first main body portion 61 and the opening 611a formed thereby, respectively. The dimension M5 in the second main body portion 62 corresponds to the dimension M4 in the first main body portion 61.
[0081] 14 to 19, in the connection structure S2, the clamp 6 is arranged in the same manner as the clamp 4 in the connection structure S1 of the first embodiment. That is, in the clamp 6, the constant diameter portion 111 of the first pipe end 11 is inserted into the constant diameter portion 211 of the second pipe end 21, and the gasket 3 is disposed between the outer circumferential surface 112a of the bulging portion 112 and the inner circumferential surface 212a of the expanded diameter portion 212. The clamp 4 is arranged on the outer circumferential sides of the first pipe end 11 and the second pipe end 21. The first flange portion 44 and the second flange portion 45 of the clamp 6 are fastened to each other by the fastening member 5. As a result, at least the apex 1123 of the bulging portion 112 and at least the tip portion 2121 of the expanded diameter portion 212 are fitted into the recesses 411, 421 of the clamp 6. At this time, the clamp 6 presses the outer peripheral surface 112a of the bulging portion 112 and the outer peripheral surface 212b of the expanded diameter portion 212 in a direction in which the bulging portion 112 and the expanded diameter portion 212 approach each other. That is, similar to the clamp 4 of the first embodiment, the clamp 6 is configured to press the outer peripheral surface 112a of the bulging portion 112 and the outer peripheral surface 212b of the expanded diameter portion 212 in a direction in which the bulging portion 112 and the expanded diameter portion 212 approach each other.
[0082] [2-2. Effect] The procedure for connecting the first pipe 1 and the second pipe 2 in the second embodiment is the same as that in the first embodiment. After the first pipe end 11 is inserted into the second pipe end 21 and the gasket 3 is placed, the clamp 6 is placed on the outer circumferential side of the bulge portion 112 and the expanded diameter portion 212. As the fastening members 5 inserted into the through holes 441, 451 are tightened, the gap between the first main body portion 61 and the second main body portion 62 gradually narrows, and the apex 1123 of the bulge portion 112 and the tip end 2121 of the expanded diameter portion 212 enter the recesses 411, 421. Then, the recesses 411, 421 come into contact with the bulge portion 112 and the expanded diameter portion 212 from the outer circumferential side. As the fastening member 5 is further tightened, the gap between the first main body portion 61 and the second main body portion 62 becomes narrower, and the recesses 411, 421 press the outer surface 112a of the bulge portion 112 (more specifically, the outer surface 1121a of the first wall portion 1121) and the outer surface 212b of the enlarged diameter portion 212 in a direction in which the bulge portion 112 and the enlarged diameter portion 212 move closer to each other.
[0083] Here, openings 611, 621 are provided in the recesses 411, 421 of the clamp 6. Therefore, when the fastening member 5 is further tightened, the first opposing portions 4111, 4211 and the second opposing portions 4112, 4212 of the recesses 411, 421 press against the outer peripheral surface 112a of the bulging portion 112 and the outer peripheral surface 212b of the enlarged diameter portion 212 as shown by the solid black arrows in Fig. 23, and are more likely to bend in the direction in which the size of the opening surface of the recesses 411, 421 increases as shown by the dotted arrows in Fig. 23.
[0084] As a result, the bulging portion 112 and the expanded diameter portion 212 are more likely to enter the innermost recesses 411, 421. That is, the openings 611, 621 guide the bulging portion 112 and the expanded diameter portion 212 toward the innermost recesses 411, 421. The opening 611 of the first main body portion 61 corresponds to an example of a guide portion that guides the bulging portion 112 and the expanded diameter portion 212 toward the innermost recesses 411, 421. Furthermore, the opening 621 of the second main body portion 62 corresponds to an example of a guide portion that guides the bulging portion 112 and the expanded diameter portion 212 toward the innermost recesses 421. Specifically, the bulging portion 112 and the expanded diameter portion 212 are guided toward the innermost recesses 411, 421 until the top 1123 of the bulging portion 112 and the tip 2121 of the expanded diameter portion 212 are inserted into the openings 611, 621.
[0085] As in the first embodiment, the fastening member 5 is tightened until the reduced diameter portion 213 contacts the outer peripheral surface 112a of the bulge portion 112 and the tightening torque required for the gasket 3 to provide a seal is reached. This fastens the first flange portion 44 and the second flange portion 45 to each other. The openings 611, 621 guide the bulge portion 112 and the expanded diameter portion 212 toward the inner sides of the recesses 411, 421. Therefore, when the fastening member 5 has completed fastening the first flange portion 44 and the second flange portion 45 to each other, the bulge portion 112 and the expanded diameter portion 212 are fitted even further into the inner sides of the recesses 411, 421. In other words, the distance between the first main body portion 61 and the second main body portion 62 becomes even narrower.
[0086] By fitting the bulging portion 112 and the expanded diameter portion 212 further into the recesses 411, 421, the outer peripheral surface 112a of the bulging portion 112 and the inner peripheral surface 212a of the expanded diameter portion 212 are more likely to press against the gasket 3, as shown by the white arrows in Fig. 23. In other words, the surface pressure on the gasket 3 increases. Therefore, the sealing performance of the gasket 3 is improved.
[0087] [2-3. Effects] According to the second embodiment described above in detail, the following effects can be obtained.
[0088] In the connecting structure S2, the recesses 411, 421 of the clamp 6 are provided with openings 611, 621. With this configuration, the first opposing portions 4111, 4211 and the second opposing portions 4112, 4212 of the recesses 411, 421 can be more easily deflected while pressing the bulging portion 112 and the expanded diameter portion 212. This allows the bulging portion 112 and the expanded diameter portion 212 to be fitted deeper into the recesses 411, 421. As a result, similar to (1a) above, the gasket 3 can be more easily pressed. This in turn improves the sealing performance of the gasket 3.
[0089] [2-4. Correspondence] In the second embodiment, the recess 411 corresponds to an example of a first recess. The recess 421 corresponds to an example of a second recess. The first side surfaces 411a, 421a correspond to an example of a bulging-side opposing surface. The second side surfaces 411b, 421b correspond to an example of a diameter-enlarging-side opposing surface.
[0090] 3. Other Embodiments Although the embodiments of the present disclosure have been described above, it goes without saying that the present disclosure is not limited to the above-described embodiments and can take on various forms.
[0091] (3a) When protrusions are provided on the first and second opposing portions as in the first embodiment, the positions of the protrusions on each of the first and second opposing portions are not particularly limited. However, as in the first embodiment, it is preferable that the protrusions on the first and second opposing portions are arranged symmetrically across the bottom. That is, it is preferable that the protrusions on the first and second opposing portions are arranged so as to overlap in the axial direction. In this case, the same effect as in (1d) above can be obtained.
[0092] (3b) In the first embodiment, the protrusions 414A-414F, 424A-424F have an oval shape extending in the circumferential direction, but the shape of the protrusions is not particularly limited. However, when the protrusions of the first opposing portion and the protrusions of the second opposing portion are arranged in positions where they overlap in the axial direction, it is preferable that the protrusions overlapping in the axial direction be formed in symmetrical shapes, as in the first embodiment. This configuration makes it easier to press the outer peripheral surface 112a of the bulging portion 112 and the outer peripheral surface 212b of the expanded diameter portion 212 more stably. Therefore, the effect of making it easier to press the gasket 3 can be more easily achieved. Ultimately, the sealing performance of the gasket 3 can be further improved.
[0093] (3c) In the first embodiment, the first to third protrusions 414A to 414C and 424A to 424C protrude from the first side surfaces 411a and 421a to a position more inward than the inner peripheral edges of the first opposing portions 4111 and 4211. The fourth to sixth protrusions 414D to 414F and 424D to 424F protrude from the second side surfaces 411b and 421b to a position more inward than the inner peripheral edges of the second opposing portions 4112 and 4212.
[0094] However, the height of the protrusions provided on the first opposing portion and the second opposing portion is not particularly limited. For example, in the first opposing portion, the protrusion may protrude from the first side surface to the same height as the inner peripheral edge of the first opposing portion in the radial direction. Similarly, in the second opposing portion, the protrusion may protrude from the second side surface to the same height as the inner peripheral edge of the second opposing portion in the radial direction.
[0095] (3d) In the first embodiment, the first opposing portions 4111, 4211 of the recesses 411, 421 are provided with a plurality of protrusions 414A-414C, 424A-424C. The second opposing portions 4112, 4212 of the recesses 411, 421 are also provided with a plurality of protrusions 414D-414F, 424D-424F. However, the number of protrusions provided on each of the first opposing portions and the second opposing portions is not particularly limited. For example, the first opposing portion and the second opposing portion may each be provided with one protrusion, or multiple protrusions as in the first embodiment.
[0096] (3e) In the first embodiment, the protrusions 414A-414F and 424A-424F are provided on both the recess 411 of the first main body portion 41 and the recess 421 of the second main body portion 42. However, the protrusions may be provided on only one of the first main body portion and the second main body portion, for example. Even in such a case, in the recess of the first or second main body portion where the protrusions are provided, the protrusions can guide the bulging portion 112 and the expanded diameter portion 212 toward the inner side of the recess. Therefore, compared to a configuration in which the protrusions are not provided on either the first or second main body portion, the gasket 3 can be pressed more easily. As a result, the sealing performance of the gasket 3 can be improved.
[0097] (3f) In the second embodiment, the dimension M4 of the opening surface of the opening 611 is larger than the dimension M2 from the apex 1123 of the bulging portion 112 to the tip 2121 of the expanded diameter portion 212. The opening 611 is configured so that a circumferential portion of each of the bulging portion 112 and the expanded diameter portion 212 can be inserted. However, even if the dimension M4 is larger than the dimension M2, the bulging portion and the expanded diameter portion do not necessarily have to be inserted into the opening.
[0098] (3g) Furthermore, the size of the opening surface of the opening is not particularly limited. For example, the dimension M4 of the opening surface of the opening may be the same as the dimension M2 from the apex 1123 of the bulging portion 112 to the tip 2121 of the expanded diameter portion 212. For example, when openings are provided in both the first main body portion and the second main body portion as in the second embodiment, the dimension M4 of the opening surface of the opening provided in the first main body portion and the dimension M5 of the opening surface of the opening provided in the second main body portion may be the same as or different from each other.
[0099] (3h) In the second embodiment, openings 611, 621 are provided in both the recess 411 of the first main body portion 61 and the recess 421 of the second main body portion 62. However, openings may be provided in only one of the first main body portion and the second main body portion, for example. Even in such a case, in the recess of the first or second main body portion where openings are provided, the openings can guide the bulging portion 112 and the expanded diameter portion 212 to the inner side of the recess. Therefore, compared to a configuration in which openings are not provided in either the first or second main body portion, the gasket 3 can be pressed more easily. As a result, the sealing performance of the gasket 3 can be improved.
[0100] (3i) The clamp 4 of the first embodiment has protrusions 414A-414F, 424A-424F as an example of a guide portion. The clamp 6 of the second embodiment has openings 611, 621 as an example of a guide portion. However, the clamp may have both protrusions and openings as an example of a guide portion. Furthermore, the clamp may have a configuration other than the protrusions and openings as an example of a guide portion.
[0101] (3j) The function of one component in the above embodiments may be distributed among multiple components, or the functions of multiple components may be integrated into one component. Also, part of the configuration of the above embodiments may be omitted. Furthermore, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments. [Explanation of symbols]
[0102] 1...first pipe, 11...first pipe end, 112...bulging portion, 2...second pipe, 21...second pipe end, 212...expanded portion, 3...gasket, 4, 6...clamp, 41, 61...first main body portion, 42, 62...second main body portion, 43...connection portion, 44...first flange portion, 45...second flange portion, 411, 421...recessed portion, 414A to 414F ,424A~424F...1st to 6th protrusions, 4111, 4211...1st opposing portion, 411a, 421a...1st side, 4112, 4212...2nd opposing portion, 411b, 421b...2nd side, 4113, 4213...bottom, 411c, 421c...bottom, 611, 621...opening, M1~M5...dimensions, S1, S2...pipe connection structure.
Claims
1. A pipe connection structure, a first pipe end portion that is one end portion of a cylindrical first pipe, the first pipe end portion having a bulging portion that bulges outward in the radial direction and extends in the circumferential direction; a second pipe end portion that is an end portion of a cylindrical second pipe that is connected to the first pipe end portion, the second pipe end portion having an expanded diameter portion that expands in diameter toward an opening of the second pipe end; a gasket disposed between an outer peripheral surface of the bulging portion and an inner peripheral surface of the enlarged diameter portion; a clamp configured to press an outer peripheral surface of the bulging portion and an outer peripheral surface of the enlarged diameter portion in a direction in which the bulging portion and the enlarged diameter portion approach each other; Equipped with The clamp is at least one recessed portion that is a recessed portion configured so that the bulging portion and the enlarged diameter portion can be fitted inside; at least one guide portion configured to guide the bulging portion and the enlarged diameter portion to a depth side of the at least one recess; A pipe connection structure having the above structure.
2. The pipe connection structure according to claim 1, The clamp is a first main body portion having an arc shape configured to cover a partial area in the circumferential direction of the bulging portion and the enlarged diameter portion from the outer circumferential side; an arc-shaped second main body portion configured to cover another partial region in the circumferential direction of the bulging portion and the enlarged diameter portion from the outer circumferential side; a connecting portion that connects the first main body portion and the second main body portion in a circumferential direction; a first flange portion extending radially outward from an end portion of the first main body portion opposite to the connection portion; a second flange portion extending radially outward from an end portion of the second main body portion opposite to the connection portion side, the second flange portion being configured to be fastened to the first flange portion; and The at least one recess is a first recess formed on an inner circumferential surface of the first main body portion; a second recess formed on an inner circumferential surface of the second main body portion; Including, A pipe connection structure, wherein the at least one guide portion is formed in at least one of the first recess and the second recess.
3. The pipe connection structure according to claim 2, A pipe connection structure, wherein the at least one guide portion is formed in both the first recess and the second recess.
4. The pipe connection structure according to any one of claims 1 to 3, The at least one recess is a first opposing portion having a bulging-side opposing surface configured to face an outer peripheral surface of the bulging portion; a second opposing portion having an expanded diameter side opposing surface configured to face the outer circumferential surface of the expanded diameter portion; and The at least one guide portion is at least one bulging-side protruding portion protruding from the bulging-side opposing surface at an end portion of the first opposing portion opposite to a deep side of the at least one recessed portion; At least one enlarged diameter side protruding portion protruding from the enlarged diameter side opposing surface at an end portion of the second opposing portion opposite to the deep side of the at least one recessed portion; A pipe connection structure including:
5. The pipe connection structure according to claim 4, the at least one bulging-side protruding portion protrudes further inward than an inner peripheral edge of the bulging-side opposing surface, A pipe connection structure, wherein the at least one enlarged diameter side protrusion protrudes radially inward beyond an inner peripheral edge of the enlarged diameter side opposing surface.
6. The pipe connection structure according to any one of claims 1 to 3, The at least one recess is a first opposing portion having a bulging-side opposing surface configured to face an outer peripheral surface of the bulging portion; a second opposing portion having an expanded diameter side opposing surface configured to face the outer circumferential surface of the expanded diameter portion; a bottom portion connecting the first opposing portion and the second opposing portion and forming a bottom surface of the at least one recess; and The at least one guide portion includes an opening that forms a circumferentially extending opening in the bottom portion.
Citation Information
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