Pipe connection tool and pipe connection method using same

Abstract

A pipe connection tool (11) for connecting two pipes is mainly configured from a cylindrical elastic body (21) made of rubber, connection parts (22A, 22B) respectively fitted to the two pipes being provided at both ends, and a film part (23) being provided in a center portion. A first reinforcing ring (31) is embedded in one connection part (22A), and a second reinforcing ring (41) is embedded in the other connection part (22B). The first reinforcing ring (31) has a first cylindrical part (32) and a first flange (33), and the second reinforcing ring (41) has a second cylindrical part (42) and a second flange (43). The first flange (33) receives the force of a jig in a direction from the other connection part (22B) toward the one connection part (22A), and the second flange (43) receives, on the outer-peripheral side of the elastic body (21), the force of a jig in a direction from the one connection part (22A) toward the other connection part (22B).

Description

Pipe connector and pipe connection method using the same

[0001] The present disclosure relates to a pipe connector and a pipe connecting method using the same.

[0002] Pipe connectors are used in various locations in various machinery fields, such as automobiles, general industrial machinery, construction machinery, etc. For example, in the automotive field, they are used as joints for cooling pipes in electric vehicles, or as joints for turbo units and intercoolers.

[0003] Japanese Patent Laid-Open Publication No. 2019-007568 (Patent Document 1) discloses a pipe connection structure in which a cylindrical member (1) interposed between two pipe flow paths (4) and (5) and formed into a cylindrical shape from a rubber-like elastic material is used to connect the two pipe flow paths while absorbing misalignment between the two pipe flow paths (see paragraphs 0024-0025 of Patent Document 1). The cylindrical member (1) has a shape in which one end side (11) that is inserted into the open end of one pipe flow path (4) and the other end side (12) that is inserted into the open end of the other pipe flow path (5) are integrally formed via a funnel-shaped bellows portion (see Figures 1, 2, 5, and 6 of Patent Document 1).

[0004] The one end (11) is fitted to the inner peripheral surface of one of the piping flow paths (4). A one end seal portion (2) is provided on the outer peripheral surface of the one end (11) (see paragraphs 0029-0032 of Patent Document 1). The one end seal portion (2) is composed of a hard embedded annular member (21) embedded in the one end (11) and a lip portion (22) bulging out from the outer peripheral surface of the one end (11).

[0005] The other end (12) is fitted to the outer peripheral surface of the other piping flow path (5). Therefore, an other end seal portion (3) is provided on the inner peripheral surface of the other end (12). In a fifth embodiment disclosed in Figure 5 of Patent Document 1, the other end seal portion (3) comprises a hard embedded annular member (35) embedded in the other end (12) and a lip portion (36) formed in a bulging manner on the inner peripheral surface of the other end (12) (see paragraph 0055 and Figure 5 of Patent Document 1).

[0006] Japanese Patent Application Laid-Open No. 2019-007568

[0007] Japanese Patent Application Laid-Open Publication No. 2019-007568 (Patent Document 1) does not mention how to connect the tubular member (1) to the two piping flow paths (4) and (5). Considering the structure of the one-end seal portion (2) provided at one end (11) and the other-end seal portion (3) provided at the other end (12), the invention described in Patent Document 1 presumably does not allow for mechanical connection using, for example, a jig, and instead requires manual connection. Therefore, it is unlikely that a strong bonding force between the two piping flow paths (4) and (5) can be expected, and high sealing performance cannot be achieved. Improvements are desired.

[0008] An object of the present disclosure is to obtain high sealing performance for two pipes to be connected.

[0009] The pipe connector of the present disclosure is interposed between two pipes arranged in series and facing each other in the axial direction, and connects the two pipes. The pipe connector includes a rubber elastic body, a first reinforcing ring having a first tubular portion and a first flange that are more rigid than the elastic body, and a second reinforcing ring having a second tubular portion and an outwardly directed second flange that are more rigid than the elastic body. The elastic body has a cylindrical shape and includes connection portions at both ends that fit with one of the pipes and the other of the pipes, respectively, and a flexible membrane portion integrally formed between the two connection portions. A seal portion that seals the pipes is integrally formed with the connection portions. The first reinforcing ring is embedded in one of the connection portions that fits with the one pipe, and the second reinforcing ring is embedded in the other connection portion that fits with the other pipe. The first flange receives the force of the jig in the direction from the other connection portion to the one connection portion, and the second flange receives the force of the jig in the direction from the one connection portion to the other connection portion on the outer circumferential side of the elastic body.

[0010] In one embodiment of the pipe connector, the first flange is an inward flange that receives the axial force of a jig inserted into the elastic body from the side of the other connection portion.

[0011] In another aspect of the pipe connector, the first flange is an outward flange that receives the axial force of a jig inserted into the membrane portion from a direction perpendicular to the axial direction.

[0012] One aspect of a pipe connection method using a pipe connector includes the steps of preparing the pipe connector of the above-mentioned one aspect, inserting a first jig having a diameter that overlaps with the first flange in the axial direction into the inside of the elastic body from the side of the other connection portion, aligning the one pipe and the one connection portion so that they fit together, pushing the first jig to pressurize the first flange and connect the one pipe and the one connection portion, removing the first jig, inserting an arc-shaped second jig into the membrane portion of the elastic body from a direction perpendicular to the axial direction, aligning the other pipe and the other connection portion so that they fit together, pressurizing the second flange with the second jig and connecting the other pipe and the other connection portion, and removing the second jig.

[0013] Another aspect of the pipe connection method using a pipe connector includes the steps of preparing the pipe connector of the above-mentioned another aspect, inserting the arc-shaped jig into the membrane portion from a direction perpendicular to the axial direction, applying pressure to the first flange with the jig while aligning the one pipe and the one connection portion so that they fit together, connecting the one pipe and the one connection portion, applying pressure to the second flange with the jig while aligning the other pipe and the other connection portion so that they fit together, and connecting the other pipe and the other connection portion, and removing the jig.

[0014] High sealing performance can be achieved for the two connected pipes.

[0015] FIG. 1 is a longitudinal sectional front view showing a pipe connector of a first embodiment; FIG. 2 is a longitudinal sectional front view of the pipe connector showing the dimensions of each part; FIG. 3 is a schematic diagram showing each step of a pipe connecting method in sequence, with (A) to (E) being a longitudinal cross-section of the pipe connector, and (F) being a front view; FIG. 4 is a schematic diagram showing each step of a pipe connecting method in sequence, with the pipe connector viewed from diagonally below; FIG. 5 is a longitudinal sectional front view showing a modified form of the pipe connector of the first embodiment; FIG. 6 is a schematic diagram showing a pipe connector of a second embodiment in a cross-sectional shape cut in half at the axis, along with a connecting step to a pipe; FIG. 7 is a schematic diagram showing a modified form of the pipe connector of the second embodiment; FIG. 8 is a schematic diagram showing a pipe connector of a third embodiment in a cross-sectional shape cut in half at the axis, along with a connecting step to a pipe; FIG. 9 is a schematic diagram showing a modified form of the pipe connector of the third embodiment; FIG. 10 is a schematic diagram showing a pipe connector of a fourth embodiment in a cross-sectional shape cut in half at the axis, along with a reinforcing member embedded in a membrane portion. 10A is a schematic diagram showing a first example of the embedding position of the reinforcing member, and FIG. 10B is a schematic diagram showing a second example. 10A is a schematic diagram showing a third example of the embedding position of the reinforcing member, and FIG. 10B is a schematic diagram showing a fourth example. 10A is a schematic diagram showing a fifth example of the embedding position of the reinforcing member, and FIG. 10B is a schematic diagram showing a sixth example. 10A is a schematic diagram showing a first form, a second form, and a third form as shapes of the membrane portion of the pipe connector of the fifth embodiment.

[0016] The embodiments will be described with reference to the drawings. The items to be described are as follows. [First embodiment] 1. Structure of pipe connector (1) Overview (2) Elastic body (3) Sealing portion (4) Reinforcing ring (5) Fitting of pipe and pipe connector 2. Pipe connection method using pipe connector (1) Step of inserting first jig (2) Step of connecting one pipe to one connection portion (3) Step of removing first jig (4) Step of inserting second jig (5) Step of connecting the other pipe to the other connection portion (6) Step of removing second jig 3. Effects (1) Improved sealing performance (2) Connection flexibility (3) Connection of pipes of the same diameter 4. Modified form [Second embodiment] 1. Structure of pipe connector 2. 3. Functions and Effects 4. Modified Forms [Third Embodiment] 1. Configuration of Pipe Connector 2. Pipe Connection Method Using Pipe Connector (1) Inserting Jig (2) Connecting One Pipe to One Connection Portion (3) Removing First Jig (4) Inserting Second Jig (5) Connecting Another Pipe to Another Connection Portion (6) Removing Second Jig 3. Functions and Effects 4. Modified Forms [Third Embodiment] 1. Configuration of Pipe Connector 2. Pipe Connection Method Using Pipe Connector (1) Inserting Jig (2) Connecting One Pipe to One Connection Portion (3) Connecting Another Pipe to Another Connection Portion (4) Removing Jig 3. Functions and Effects 4. Modified Forms [Fourth Embodiment] 1. Configuration of Pipe Connector 2. Pipe Connection Method Using Pipe Connector 3. Advantages and Effects (1) Improved durability (2) Suppression of buckling (3) Improved tensile strength (4) Lightweight (5) Adjustment of eccentricity followability [Fifth embodiment] 1. Configuration of pipe connector 2. Pipe connection method using pipe connector 3. Advantages and Effects [Modification]

[0017] [First Embodiment] A first embodiment will be described with reference to FIGS. 1 to 5. FIG.

[0018] 1. Configuration of the Pipe Connector (1) Overview As shown in Figures 1 to 4, the pipe connector 11 of this embodiment is interposed between two pipes 101 arranged in series facing each other in the axial direction, and connects the two pipes 101.

[0019] For ease of explanation, one of the two pipes 101 will be referred to as pipe 101A, and the other pipe 101 will be referred to as pipe 101B. In Fig. 1, the axis passing through the center of the pipe connector 11 is indicated by symbol X. In Fig. 3, the axis passing through the center of pipe 101A is indicated by symbol Y, and the axis passing through the center of pipe 101B is indicated by symbol Z.

[0020] In the drawings, the symbol A indicates the axial direction, and the symbol R indicates the radial direction perpendicular to the axial direction A. When the two pipes (101A, 101B) and the pipe connector 11 are arranged in the correct positions, the axes X, Y, and Z are located on the same axis and are parallel to the axial direction A. However, in reality, the two pipes (101A, 101B) are misaligned in the axial direction A, the radial direction R, or by changing the angle so that the two axes Y and Z intersect.

[0021] In another embodiment, the axis Y of the pipe 101A and the axis Z of the pipe 101B do not necessarily have to coincide on the same axis. The axes Y and Z may be misaligned parallel to each other or may intersect. Such a misalignment of the axes Y and Z may be the normal position of the two pipes 101 (101A, 101B).

[0022] This embodiment discloses a pipe connector 11 that connects two pipes 101 (101A, 101B) while absorbing unintentional or inherently expected axial misalignment.

[0023] The pipe connector 11 is mainly composed of a rubber elastic body 21. The elastic body 21 has connection portions 22 at both ends that fit into end E1 of pipe 101A and end E2 of pipe 101B, respectively, and a flexible membrane portion 23 is provided integrally between the two connection portions 22. For ease of explanation, one connection portion 22 that connects to pipe 101A will be referred to as connection portion 22A, and the other connection portion 22 that connects to pipe 101B will be referred to as connection portion 22B.

[0024] A first reinforcing ring 31 made of a material with higher rigidity than the elastic body 21 is embedded in the connecting portion 22A. The first reinforcing ring 31 includes a first cylindrical portion 32 and a first flange 33. The first flange 33 is bent at a right angle inward in the radial direction R from an end of the first cylindrical portion 32 that is on the leading side in the fitting direction to the pipe 101A in the axial direction A.

[0025] The elastic body 21 is connected to the pipe 101A by fitting the connecting portion 22A to the inner peripheral surface of the pipe 101A. A seal portion 24A is integrally provided on the outer peripheral surface of the connecting portion 22A.

[0026] A second reinforcing ring 41 made of a material with higher rigidity than the elastic body 21 is embedded in the connecting portion 22B. The second reinforcing ring 41 includes a second cylindrical portion 42 and a second flange 43. The second flange 43 is bent at a right angle outward in the radial direction R from an end of the second cylindrical portion 42 on the rear side in the fitting direction to the pipe 101B in the axial direction A.

[0027] The elastic body 21 is connected to the pipe 101B by fitting the connecting portion 22B to the inner peripheral surface of the pipe 101B. A seal portion 24B is integrally provided on the outer peripheral surface of the connecting portion 22B.

[0028] (2) Elastic Body The elastic body 21 is formed from rubber, such as chloroprene rubber (CR), ethylene propylene rubber (EPDM), or acrylic rubber (ACM).

[0029] As shown in FIG. 1, the shape of the elastic body 21 is basically cylindrical, but is not a perfect cylindrical shape.

[0030] The end portion on the connecting portion 22A side extends inward in the radial direction R. A first flange 33 is embedded in this portion.

[0031] A part of the outer peripheral surface of the elastic body 21 near the connecting portion 22B protrudes outward in the radial direction R. A second flange 43 is embedded in this part.

[0032] Therefore, the first flange 33 and the second flange 43 are covered with the rubber that constitutes the elastic body 21.

[0033] The inner circumferential surface of the elastic body 21 maintains a uniform inner diameter d1 throughout its entire area. However, on the connection portion 22B side, only the area near the opening has an inner diameter d2 that is slightly larger than the inner diameter d1. The area of ​​the inner diameter d2 is approximately one-third the length of the second cylindrical portion 42 in the axial direction A.

[0034] The outer diameter of the outer peripheral surface of the elastic body 21 is set to an outer diameter d3. The two seal portions 24A and 24B, which have the same diameter, have an outer diameter d4 that is slightly larger than the outer diameter d3. The outer peripheral surface of the elastic body 21, at the portion where the second flange 43 is embedded, has a maximum outer diameter d5.

[0035] In elastic body 21, the region where first reinforcing ring 31 is embedded is connection portion 22A, the region where second reinforcing ring 41 is embedded is connection portion 22B, and the region between connection portions 22A and 22B is membrane portion 23. Membrane portion 23 is a flexible region made only of rubber, and absorbs axial misalignment that occurs between connection portions 22A and 22B.

[0036] (3) Sealing Portion As described above, the elastic body 21 has the sealing portion 24A integrally formed on the outer peripheral surface of the connecting portion 22A, and the sealing portion 24B integrally formed on the outer peripheral surface of the connecting portion 22B.

[0037] As shown in FIG. 1 , the seal portion 24A protrudes annularly from the outer circumferential surface of the connection portion 22A at a position corresponding to the first tubular portion 32. The amount of protrusion is (d4-d3) / 2. The seal portion 24A and the first reinforcing ring 31 cooperate to seal the joint between the pipe 101A and the connection portion 22A. In other words, the seal portion 24A increases the contact pressure with the inner circumferential surface of the pipe 101A to strengthen the sealing action, and at this time, the first tubular portion 32 absorbs the force acting on the seal portion 24A that tends to escape inward in the radial direction R.

[0038] The seal portion 24B protrudes annularly from the outer peripheral surface of the connection portion 22B at a position corresponding to the second tubular portion 42. The amount of protrusion is (d4-d3) / 2. The seal portion 24B and the second reinforcing ring 41 cooperate to seal the joint between the pipe 101B and the connection portion 22B. In other words, the seal portion 24B increases the contact pressure with the inner peripheral surface of the pipe 101B to strengthen the sealing action, and at this time the second tubular portion 42 receives the force acting on the seal portion 24B that tries to escape inward in the radial direction R.

[0039] (4) Reinforcing Rings The first reinforcing ring 31 and the second reinforcing ring 41 are annular members manufactured by, for example, pressing metal. In addition to metal, any material, such as synthetic resin, may be used as long as it has higher rigidity than the elastic body 21 and can increase the bonding strength between the pipe 101 (101A, 101B) and the connection portion 22 (22A, 22B).

[0040] 1, the first tubular portion 32 of the first reinforcing ring 31 and the second tubular portion 42 of the second reinforcing ring 41 both have a cylindrical shape with a diameter slightly larger than the larger inner diameter d2 of the elastic body 21. The first tubular portion 32 and the second tubular portion 42 have the same diameter.

[0041] The first flange 33 of the first reinforcing ring 31 is an inward flange with an opening in the center. The diameter of the opening, i.e., the inner diameter d6 of the first flange 33, is smaller than the smaller inner diameter d1 of the elastic body 21. Therefore, when viewing the connection portion 22A from the connection portion 22B side, the first flange 33 extends further inward in the radial direction R than the inner wall of the elastic body 21.

[0042] The second flange 43 of the second reinforcing ring 41 is an outward flange. The outer diameter d7 of the second flange 43 is larger than the outer diameter d4 of the two seal portions 24A and 24B. Therefore, when the connection portion 22A is viewed from the connection portion 22B side, the second flange 43 extends further outward in the radial direction R than the two seal portions 24A and 24B.

[0043] (5) Fitting of Pipes and Pipe Connectors The two connectors 22 (22A, 22B) of the elastic body 21 are fitted to the inner peripheries of the two pipes 101 (101A, 101B), respectively.

[0044] The two pipes 101 (101A, 101B) have the same inner diameter. Therefore, the diameter of the fitting portion of the connection portion 22A to the pipe 101A matches the diameter of the fitting portion of the connection portion 22B to the pipe 101B.

[0045] The inner diameter of the pipe 101A is the same as or slightly smaller than the outer diameter d3 of the elastic body 21. The inner diameter of the pipe 101B is also the same as or slightly smaller than the outer diameter d3 of the elastic body 21. Therefore, when the two connection portions 22 (22A, 22B) are fitted to the two pipes 101 (101A, 101B), respectively, the seal portions 24A and 24B are crushed.

[0046] The end E1 of the pipe 101A has a step S1 formed therein, and the end surface ES1 of the connection part 22A fitted to the pipe 101A abuts against the step S1.

[0047] The end E2 of the pipe 101B has a step S2 formed therein, and an end surface ES2 of the connection portion 22B fitted to the pipe 101B abuts against the step S2.

[0048] 2. Pipe Connection Method Using Pipe Connector A method for connecting two pipes 101 (101A, 101B) with the pipe connector 11 will be described mainly with reference to FIGS.

[0049] (1) Step of Inserting the First Jig As shown in FIGS. 3A and 4A, the pipe connector 11 is prepared, and the first jig 201 is inserted into the elastic body 21.

[0050] The first jig 201 is a cylindrical member having an outer diameter slightly smaller than the inner diameter d1 of the elastic body 21 and larger than the inner diameter d6 of the first flange 33. In other words, the first jig 201 has a diameter that overlaps with the first flange 33 in the axial direction A.

[0051] In this step, the first jig 201 is inserted into the elastic body 21 from the side of the connection portion 22B. The first jig 201 abuts against the rubber covering the first flange 33. The first flange 33 receives the force of the first jig 201 in the direction from the connection portion 22B toward the connection portion 22A.

[0052] 3(B) and 4(B), the pipe 101A and the connection portion 22A of the elastic body 21 are aligned so as to fit together. In this state, the first jig 201 is pushed in and pressure is applied to the first flange 33. The first flange 33 receives the force of the first jig 201 in the direction from the connection portion 22B toward the connection portion 22A, and pushes the connection portion 22A into the inside of the pipe 101A. When the end surface ES1 of the connection portion 22A abuts against the step portion S1 of the pipe 101A, the pipe 101A and the connection portion 22A are connected.

[0053] As another method, while the pipe 101A and the connection portion 22A of the elastic body 21 are aligned to fit together, the pipe 101A may be pressed against the side of the first jig 201 inserted inside the elastic body 21. When the step portion S1 of the pipe 101A abuts against the end surface ES1 of the connection portion 22A, the pipe 101A and the connection portion 22A are connected to each other.

[0054] Whichever method is adopted, the seal portion 24A is crushed at this time, and the pipe 101A and the connection portion 22A are sealed.

[0055] (3) Step of Removing the First Jig As shown in FIGS. 3C and 4C, once the pipe 101A and the connection portion 22A are connected, the first jig 201 is pulled out and removed from the elastic body 21.

[0056] (4) Step of Inserting Second Jig As shown in FIG. 3(D) and FIG. 4(D), the second jig 211 is inserted into the elastic body 21.

[0057] The second jig 211 is an arc-shaped member that resembles a cylindrical member cut in the axial direction. The axial thickness of the second jig 211 is set to be narrower than the distance between the end E1 of the pipe 101A connected to the connection portion 22A and the rubber portion of the elastic body 21 that covers the second flange 43.

[0058] In this step, the second jig 211 is inserted into the membrane portion 23 of the elastic body 21 from a direction (radial direction R) perpendicular to the axial direction A. The part that is inserted into the membrane portion 23 is the arc-shaped inner wall portion of the second jig 211.

[0059] (5) Step of connecting the other pipe and the other connection portion As shown in Figures 3(E) and 4(E), the pipe 101B and the connection portion 22B are aligned so as to fit together. As a result, the second jig 211 is positioned so as to overlap the second flange 43 in the axial direction A. When the second jig 211 presses the second flange 43 in this state, the second flange 43 receives the force of the second jig 211 in the direction from the connection portion 22A toward the connection portion 22B, and pushes the connection portion 22B into the inside of the pipe 101B. When the end face ES2 of the connection portion 22B abuts against the step portion S2 of the pipe 101B, the pipe 101B and the connection portion 22B are connected.

[0060] As another method, while the pipe 101B and the connection portion 22B are aligned to fit together, the pipe 101B may be pressed against the side of the second jig 211 attached to the membrane portion 23. When the step portion S2 of the pipe 101B abuts against the end surface ES2 of the connection portion 22B, the pipe 101B and the connection portion 22B are connected to each other.

[0061] Whichever method is adopted, the seal portion 24B is crushed at this time, and the pipe 101B and the connection portion 22B are sealed.

[0062] (6) Step of Removing the Second Jig As shown in FIGS. 3(F) and 4(F), once the pipe 101B and the connection portion 22B are connected, the second jig 211 is pulled out and removed from the elastic body 21.

[0063] In this way, the pipe 101A and the connector 22A are connected, and the pipe 101B and the connector 22B are connected, and the two pipes 101 (101A, 101B) are connected by the pipe connector 11.

[0064] 3. Effects and Advantages The pipe connector 11 of this embodiment and the pipe connecting method using the same are configured as described above, and therefore have the following various effects and advantages.

[0065] (1) Improved Sealing Performance According to this embodiment, a first jig 201 is used to connect the pipe 101A and the connection portion 22A, and a second jig 211 is used to connect the pipe 101B and the connection portion 22B. This allows the two pipes 101 (101A, 101B) and the two connection portions 22 (22A, 22B) to be connected by press-fitting using a machine. This increases the interference between the two pipes 101 (101A, 101B) and the two connection portions 22 (22A, 22B), making it possible to connect the two with a large bonding force. As a result, high sealing performance can be obtained for the two connected pipes 101 (101A, 101B).

[0066] (2) Connection Flexibility The membrane portion 23 provided on the elastic body 21 is flexible, and therefore absorbs axial misalignment that occurs between the two pipes 101 (101A, 101B). Therefore, the pipe connector 11 of this embodiment can follow static or dynamic eccentricity between the two pipes 101 (101A, 101B).

[0067] (3) Connecting pipes of the same diameter The first flange 33 receives the force of the first jig 201 from the inner side of the elastic body 21, and the second flange 43 receives the force of the second jig 211 from the outer side of the elastic body 21, so that two pipes 101 (101A, 101B) of the same diameter can be connected.

[0068] 4. Modified Form Fig. 5 is a vertical sectional front view showing a modified form of the pipe connector 11 of the first embodiment.

[0069] This embodiment is a variation of the seal portion. In addition to seal portions 24A and 24B, elastic body 21 of this embodiment has three types of seal portions: 24C1, 24C2, and 24D2. In Fig. 5, seal portions 24C1, 24C2, and 24D2 are schematically shown with circles indicating their positions.

[0070] The seal portion 24C1 is provided in an annular shape on the end surface ES1 of the connection portion 22A at a position axially coinciding with the first cylindrical portion 32 of the first reinforcing ring 31. When the connection portion 22A is fitted to the pipe 101A, the seal portion 24C1 abuts against a step portion S1 provided in the end portion E1 of the pipe 101A, thereby sealing the pipe 101A and the connection portion 22A.

[0071] The seal portion 24C2 is provided in an annular shape on the end surface ES2 of the connection portion 22B at a position axially coinciding with the second cylindrical portion 42 of the second reinforcing ring 41. When the connection portion 22B is fitted to the pipe 101B, the seal portion 24C2 abuts against a step portion S2 provided in the end portion E2 of the pipe 101B, thereby sealing the pipe 101B and the connection portion 22B.

[0072] The seal portion 24D2 is provided in an annular shape on a portion of the rubber of the elastic body 21 that covers the second flange 43, the portion facing the pipe 101B. When the connection portion 22B is fitted to the pipe 101B, the seal portion 24D2 abuts against the end E2 of the pipe 101B, sealing the pipe 101B and the connection portion 22B.

[0073] [Second embodiment] A second embodiment will be described with reference to Figures 6 and 7. The same parts as those in the first embodiment are denoted by the same reference numerals, and their description will be omitted.

[0074] 1. Configuration of the Pipe Connector This embodiment differs from the first embodiment in that two connection portions 22 (22A, 22B) of the elastic body 21 are fitted onto the outer peripheries of two pipes 101 (101A, 101B), respectively. Due to this structure, both seal portions 24A and 24B are provided on the inner periphery of the elastic body 21.

[0075] The first reinforcing ring 31 has a first flange 33 at the end of the first cylindrical portion 32 on the rear side in the fitting direction to the pipe 101A.

[0076] 2. Pipe Connection Method Using Pipe Connector A method for connecting two pipes 101 (101A, 101B) with the pipe connector 11 will be described with reference to FIG.

[0077] (1) Step of Inserting the First Jig The pipe connector 11 is prepared, and the first jig 201 is inserted into the elastic body 21 .

[0078] The first jig 201 has a diameter that overlaps with the first flange 33 in the axial direction A. Therefore, the first jig 201 inserted inside the elastic body 21 abuts against the rubber covering the first flange 33. The first flange 33 receives the force of the first jig 201 in the direction from the connection portion 22B toward the connection portion 22A.

[0079] (2) Step of connecting one pipe and one connection portion The pipe 101A and the connection portion 22A of the elastic body 21 are aligned so as to fit together. In this state, the first jig 201 is pushed in and pressure is applied to the first flange 33. The first flange 33 receives the force of the first jig 201 in the direction from the connection portion 22B toward the connection portion 22A, and pushes the connection portion 22A into the inside of the pipe 101A. When the end surface ES1 of the connection portion 22A abuts against the step portion S1 of the pipe 101A, the pipe 101A and the connection portion 22A are connected.

[0080] As another method, while the pipe 101A and the connection portion 22A of the elastic body 21 are aligned to fit together, the pipe 101A may be pressed against the side of the first jig 201 inserted inside the elastic body 21. In this case, when the step portion S1 of the pipe 101A abuts against the end surface ES1 of the connection portion 22A, the pipe 101A and the connection portion 22A are connected to each other.

[0081] Whichever method is adopted, the seal portion 24A is crushed at this time, and the pipe 101A and the connection portion 22A are sealed.

[0082] (3) Step of Removing the First Jig Once the pipe 101A and the connection portion 22A are connected, the first jig 201 is pulled out and removed from the elastic body 21.

[0083] (4) Step of Inserting Second Jig The second jig 211 is inserted into the elastic body 21 .

[0084] The second jig 211 is a member having an arc-like shape as if a cylindrical member had been cut in the axial direction (see FIGS. 4(D) to (F) showing the first embodiment).

[0085] In this step, the second jig 211 is inserted into the membrane portion 23 of the elastic body 21 from a direction (radial direction R) perpendicular to the axial direction A. The part that is inserted into the membrane portion 23 is the arc-shaped inner wall portion of the second jig 211.

[0086] (5) Step of connecting the other pipe and the other connection portion The pipe 101B and the connection portion 22B are aligned so as to fit together. As a result, the second jig 211 is positioned so as to overlap the second flange 43 in the axial direction A. When the second jig 211 applies pressure to the second flange 43 in this state, the second flange 43 receives the force of the second jig 211 in the direction from the connection portion 22A toward the connection portion 22B, and pushes the connection portion 22B into the inside of the pipe 101B. When the end face ES2 of the connection portion 22B abuts against the step portion S2 of the pipe 101B, the pipe 101B and the connection portion 22B are connected.

[0087] As another method, while the pipe 101B and the connection portion 22B are aligned to fit together, the pipe 101B may be pressed against the side of the second jig 211 attached to the membrane portion 23. When the step portion S2 of the pipe 101B abuts against the end surface ES2 of the connection portion 22B, the pipe 101B and the connection portion 22B are connected to each other.

[0088] Whichever method is adopted, the seal portion 24B is crushed at this time, and the pipe 101B and the connection portion 22B are sealed.

[0089] (6) Step of Removing Second Jig Once the pipe 101B and the connection portion 22B are connected, the second jig 211 is pulled out and removed from the elastic body 21.

[0090] In this way, the pipe 101A and the connector 22A are connected, and the pipe 101B and the connector 22B are connected, and the two pipes 101 (101A, 101B) are connected by the pipe connector 11.

[0091] 3. Effects This embodiment also has the same effects as the first embodiment.

[0092] 4. Modified Form Fig. 7 is a vertical sectional front view showing a modified form of the pipe connector 11 of the second embodiment.

[0093] This embodiment is a variation of the seal portion. In addition to seal portions 24A and 24B, elastic body 21 of this embodiment has three types of seal portions: 24C1, 24C2, and 24D1. In Fig. 7, seal portions 24C1, 24C2, and 24D1 are schematically shown with circles indicating their positions.

[0094] The seal portion 24C1 is provided in an annular shape on the end surface ES1 of the connection portion 22A at a position axially coinciding with the first cylindrical portion 32 of the first reinforcing ring 31. When the connection portion 22A is fitted to the pipe 101A, the seal portion 24C1 abuts against a step portion S1 provided in the end portion E1 of the pipe 101A, thereby sealing the pipe 101A and the connection portion 22A.

[0095] The seal portion 24C2 is provided in an annular shape on the end surface ES2 of the connection portion 22B at a position axially coinciding with the second cylindrical portion 42 of the second reinforcing ring 41. When the connection portion 22B is fitted to the pipe 101B, the seal portion 24C2 abuts against a step portion S2 provided in the end portion E2 of the pipe 101B, thereby sealing the pipe 101B and the connection portion 22B.

[0096] The seal portion 24D1 is provided in an annular shape on a portion of the rubber of the elastic body 21 that covers the first flange 33, the portion facing the pipe 101A. When the connection portion 22A is fitted to the pipe 101A, the seal portion 24D1 abuts against the end E1 of the pipe 101A, sealing the pipe 101A and the connection portion 22A.

[0097] [Third embodiment] A third embodiment will be described with reference to Figures 8 and 9. The same parts as those in the first and second embodiments are denoted by the same reference numerals, and their description will be omitted.

[0098] 1. Configuration of the Pipe Connector This embodiment is similar to the first embodiment in that two connection portions 22 (22A, 22B) of the elastic body 21 are fitted to the inner peripheries of two pipes 101 (101A, 101B), respectively, but differs from the second embodiment. Due to this structure, both seal portions 24A and 24B are provided on the outer periphery of the elastic body 21.

[0099] The first reinforcing ring 31 has a first flange 33 at the end of the first cylindrical portion 32, which is located on the rear side in the fitting direction to the pipe 101A. This point differs from the first embodiment, but is common to the second embodiment. However, unlike the second embodiment, the first flange 33 is an outward flange. Because the first flange 33 is an outward flange, the first flange 33 and the second flange 43 face each other with the membrane portion 23 sandwiched therebetween.

[0100] Other points are common to the first and second embodiments.

[0101] 2. Pipe Connection Method Using Pipe Connector A method for connecting two pipes 101 (101A, 101B) with the pipe connector 11 will be described with reference to FIG.

[0102] (1) Jig Insertion Step The pipe connector 11 is prepared, and the jig 221 is inserted into the elastic body 21 .

[0103] The jig 221 is a member having an arc-like shape as if a cylindrical member had been cut in the axial direction. The axial thickness of the jig 221 is set to be narrower than the distance between the first flange 33 and the second flange 43 that face each other via the membrane portion 23. The jig 221 has a diameter that overlaps with the first flange 33 and the second flange 43 in the axial direction A.

[0104] In this step, the jig 221 is inserted into the membrane portion 23 of the elastic body 21 from a direction (radial direction R) perpendicular to the axial direction A. The part that is inserted into the membrane portion 23 is the arc-shaped inner wall portion of the jig 221.

[0105] (2) Step of connecting one pipe to one connection portion The pipe 101A and the connection portion 22A of the elastic body 21 are aligned so as to fit together. In this state, the jig 221 is pushed toward the pipe 101A, and pressure is applied to the first flange 33. The first flange 33 receives the force of the jig 221 in the direction from the connection portion 22B toward the connection portion 22A, and pushes the connection portion 22A into the inside of the pipe 101A. When the end surface ES1 of the connection portion 22A abuts against the step portion S1 of the pipe 101A, the pipe 101A and the connection portion 22A are connected.

[0106] As another method, the pipe 101A may be pressed against the jig 221 attached to the membrane part 23 while the pipe 101A and the connection part 22A of the elastic body 21 are aligned so as to fit together. In this case, when the step part S1 of the pipe 101A abuts against the end surface ES1 of the connection part 22A, the pipe 101A and the connection part 22A are connected to each other.

[0107] Whichever method is adopted, the seal portion 24A is crushed at this time, and the pipe 101A and the connection portion 22A are sealed.

[0108] (3) Step of connecting the other pipe and the other connection portion Pipe 101B and connection portion 22B are aligned so that they fit together. In this state, jig 221 is pushed toward pipe 101B, and pressure is applied to second flange 43. Second flange 43 receives the force of jig 221 in the direction from connection portion 22A toward connection portion 22B, and pushes connection portion 22B into pipe 101B. When end surface ES2 of connection portion 22B abuts against step portion S2 of pipe 101B, pipe 101B and connection portion 22B are connected.

[0109] As another method, the pipe 101B may be pressed against the jig 221 attached to the membrane part 23 while the pipe 101B and the connection part 22B are aligned to fit together. When the step part S2 of the pipe 101B abuts against the end surface ES2 of the connection part 22B, the pipe 101B and the connection part 22B are connected to each other.

[0110] Whichever method is adopted, the seal portion 24B is crushed at this time, and the pipe 101B and the connection portion 22B are sealed.

[0111] (4) Jig Removal Process After the pipe 101B and the connection portion 22B are connected, the jig 221 is pulled out and removed from the elastic body 21.

[0112] In this way, the pipe 101A and the connector 22A are connected, and the pipe 101B and the connector 22B are connected, and the two pipes 101 (101A, 101B) are connected by the pipe connector 11.

[0113] 3. Effects According to this embodiment, jig 221 is attached to membrane portion 23 of elastic body 21, and this single jig 221 can support both the operation of connecting pipe 101A to connection portion 22A and the operation of connecting pipe 101B to connection portion 22B. Therefore, by using the single jig 221 for both purposes, the pipe connecting method can be performed with a reduced number of steps, thereby improving work efficiency.

[0114] In other respects, this embodiment also has the same effects as the first and second embodiments.

[0115] 4. Modified Form Fig. 9 is a vertical sectional front view showing a modified form of the pipe connector 11 of the third embodiment.

[0116] This embodiment is a variation of the seal portion. In addition to seal portions 24A and 24B, elastic body 21 of this embodiment has four types of seal portions: 24C1, 24C2, 24D1, and 24D2. In Fig. 9, seal portions 24C1, 24C2, 24D1, and 24D2 are schematically shown with circles indicating their positions.

[0117] The seal portion 24C1 is provided in an annular shape on the end surface ES1 of the connection portion 22A at a position axially coinciding with the first cylindrical portion 32 of the first reinforcing ring 31. When the connection portion 22A is fitted to the pipe 101A, the seal portion 24C1 abuts against a step portion S1 provided in the end portion E1 of the pipe 101A, thereby sealing the pipe 101A and the connection portion 22A.

[0118] The seal portion 24C2 is provided in an annular shape on the end surface ES2 of the connection portion 22B at a position axially coinciding with the second cylindrical portion 42 of the second reinforcing ring 41. When the connection portion 22B is fitted to the pipe 101B, the seal portion 24C2 abuts against a step portion S2 provided in the end portion E2 of the pipe 101B, thereby sealing the pipe 101B and the connection portion 22B.

[0119] The seal portion 24D1 is provided in an annular shape on a portion of the rubber of the elastic body 21 that covers the first flange 33, the portion facing the pipe 101A. When the connection portion 22A is fitted to the pipe 101A, the seal portion 24D1 abuts against the end E1 of the pipe 101A, sealing the pipe 101A and the connection portion 22A.

[0120] The seal portion 24D2 is provided in an annular shape on a portion of the rubber of the elastic body 21 that covers the second flange 43, the portion facing the pipe 101B. When the connection portion 22B is fitted to the pipe 101B, the seal portion 24D2 abuts against the end E2 of the pipe 101B, sealing the pipe 101B and the connection portion 22B.

[0121] [Fourth embodiment] A fourth embodiment will be described with reference to Figures 10 to 13. The same parts as those in the first to third embodiments are designated by the same reference numerals, and their description will be omitted.

[0122] 1. Configuration of the Pipe Connector In the pipe connector 11 of this embodiment, a reinforcing member 51 is embedded in the membrane portion 23 of the elastic body 21. The reinforcing member 51 has a structure that can increase the rigidity of the membrane portion 23, and for example, a coil spring 52, a base fabric 53, or the like can be used as the reinforcing member 51.

[0123] The coil spring 52 has a structure in which an elastic linear member is wound in a spiral shape, and matches the shape of the cylindrical membrane portion 23, making it possible to easily embed the coil spring 52 within the cylindrical shape of the membrane portion 23. The coil spring 52 expands and contracts in the axial direction A, and also elastically deforms in both the axial direction A and the radial direction R, thereby increasing the rigidity of the membrane portion 23 when embedded within the membrane portion 23.

[0124] The base fabric 53 is a fabric product made by intertwining warp and weft threads, with the weft threads woven between warp threads that intersect vertically. Because the base fabric 53 is flexible, it can be embedded in the membrane 23 to conform to the cylindrical shape of the membrane 23. The embedded base fabric 53 suppresses deformation of the membrane 23 and increases its rigidity.

[0125] 11(A) and 11(B), a reinforcing member 51 such as a coil spring 52 or a base fabric 53 can be embedded in the membrane portion 23 at a position on the axial direction A that passes through the first tubular portion 32 and the second tubular portion 42. The reinforcing member 51 may be disposed so as to be in a non-contact state with the first tubular portion 32 and the second tubular portion 42 (see FIG. 11(A)), or may be disposed so as to be in contact with the first tubular portion 32 and the second tubular portion 42 (see FIG. 11(B)).

[0126] 12(A) and 12(B), a reinforcing member 51 such as a coil spring 52 or a base fabric 53 can be embedded in the membrane portion 23 on the inner circumferential side of the first tubular portion 32 and the second tubular portion 42 along the axial direction A. The reinforcing member 51 may be disposed so as to be out of contact with the first tubular portion 32 and the second tubular portion 42 (see FIG. 12(A)), or so as to be in contact with the first tubular portion 32 and the second tubular portion 42 (see FIG. 12(B)).

[0127] 13(A) and 13(B) is an example in which a base fabric 53 is used as the reinforcing member 51. The base fabric 53 is embedded in the membrane portion 23 so that one end is on the outer periphery of the first tubular portion 32 and the other end is on the inner periphery of the second tubular portion 42. The base fabric 53 may be arranged so as to be out of contact with the first tubular portion 32 and the second tubular portion 42 (see FIG. 13(A)), or so as to be in contact with them (see FIG. 13(B)).

[0128] 13(A) and 13(B), one end of the base fabric 53 may be disposed on the inner periphery side of the first tubular portion 32 and the other end on the outer periphery side of the second tubular portion 42. In this case, the base fabric 53 may be disposed so as to be in a non-contact state with the first tubular portion 32 and the second tubular portion 42, or may be disposed so as to be in contact with them.

[0129] 10 to 13 show a configuration example in which a reinforcing member 51 is embedded in the membrane portion 23 of the pipe connector 11 of the first embodiment. The object in which the reinforcing member 51 is embedded in the membrane portion 23 is not limited to the first embodiment, and may be the pipe connector 11 of the second embodiment or the third embodiment.

[0130] When a reinforcing member 51 is embedded in the membrane portion 23 of the pipe connector 11 of the first embodiment, the connection direction of two pipes 101 (101A, 101B) using this follows the pipe connection method of the first embodiment illustrated in Figures 3 and 4.

[0131] When a reinforcing member 51 is embedded in the membrane portion 23 of the pipe connector 11 of the second embodiment, the connection direction of two pipes 101 (101A, 101B) using this follows the pipe connection method of the second embodiment illustrated in Figure 6.

[0132] When a reinforcing member 51 is embedded in the membrane portion 23 of the pipe connector 11 of the third embodiment, the connection direction of two pipes 101 (101A, 101B) using this follows the pipe connection method of the third embodiment illustrated in Figure 8.

[0133] 3. Effects and advantages The embedded reinforcing member 51 increases the rigidity of the membrane portion 23 without impairing its ability to follow static or dynamic eccentricity between the two pipes 101 (101A, 101B). As a result, the following effects and advantages are achieved.

[0134] (1) Improved durability When a fluid flows between two pipes 101 (101A, 101B) connected via a pipe connector 11, an increase in internal pressure generates a force that tends to inflate the membrane portion 23. According to this embodiment, the reinforcing member 51 suppresses the expansion of the membrane portion 23, thereby improving the durability of the membrane portion 23.

[0135] (2) Buckling Suppression The reinforcing member 51 can also generate a restraining force against buckling of the membrane portion 23. Therefore, even if an excessive force that would cause buckling is applied to the membrane portion 23 during the work of connecting the connection portions 22 (22A, 22B) of the pipe connector 11 to the pipes 101 (101A, 101B), the membrane portion 23 can be protected from buckling.

[0136] (3) Improved tensile strength The reinforcing member 51 also increases the tensile strength of the membrane portion 23. For example, when the connection portion 22 (22A, 22B) of the pipe connector 11 is removed from the pipe 101 (101A, 101B) for maintenance or the like, even if an excessive tensile force that could cause damage is applied to the membrane portion 23, the reinforcing member 51 can protect the membrane portion 23 from damage.

[0137] (4) Weight Reduction As a result of providing the reinforcing member 51, it is possible to ensure the above-mentioned improvement in durability, suppression of buckling, and improvement in tensile strength even when the membrane portion 23 is thinned. Therefore, the amount of rubber in the membrane portion 23 can be reduced, and the weight of the elastic body 21 can be reduced.

[0138] (5) Adjustment of Eccentricity Tracking Ability When the coil spring 52 is used as the reinforcing member 51, the eccentricity tracking ability of the membrane portion 23 can be adjusted by adjusting the spring strength.

[0139] The elasticity of the base fabric 53 can be changed by changing the mesh size, which varies depending on how the warp and weft threads are entangled, the materials of the warp and weft threads, etc. When the base fabric 53 is used as the reinforcing member 51, the eccentricity followability of the membrane portion 23 can be adjusted by changing the elasticity of the base fabric 53.

[0140] 14A to 14C, the fifth embodiment will be described. The same parts as those in the first to third embodiments are designated by the same reference numerals, and the description thereof will be omitted.

[0141] 1. Configuration of the Pipe Connector The membrane portion 23 in the first to fourth embodiments has a straight shape along the axial direction A. In contrast, the membrane portion 23 in the present embodiment has a curved shape when viewed in cross section. Three shapes of the curved membrane portion 23 are introduced.

[0142] 14A is a schematic diagram showing an elastic body 21 having a first type of membrane portion 23. The membrane portion 23 has a shape in which the central portion is constricted in a curved shape, and the central portion has a smaller diameter than both end portions.

[0143] 14(B) is a schematic diagram showing an elastic body 21 having a second type of membrane portion 23. The membrane portion 23 has a barrel shape with a curved central portion bulging out, and the central portion has a larger diameter than the end portions.

[0144] 14C is a schematic diagram showing an elastic body 21 having a third type of membrane portion 23. The membrane portion 23 has a bellows shape that expands and contracts in the axial direction.

[0145] 2. Pipe Connection Method Using Pipe Connector The membrane portion 23 of the first to third embodiments may be applied to any of the pipe connectors 11 of the first to third embodiments.

[0146] When any one of the membrane parts 23 of the first to third forms shown in Figures 14 (A) to (C) is applied to the membrane part 23 of the pipe connector 11 of the first embodiment, the connection direction of the two pipes 101 (101A, 101B) using this follows the pipe connection method of the first embodiment illustrated in Figures 3 and 4.

[0147] When any one of the membrane parts 23 of the first to third forms shown in Figures 14 (A) to (C) is applied to the membrane part 23 of the pipe connector 11 of the second embodiment, the connection direction of the two pipes 101 (101A, 101B) using this follows the pipe connection method of the second embodiment illustrated in Figure 6.

[0148] When any one of the membrane parts 23 of the first to third forms shown in Figures 14 (A) to (C) is applied to the membrane part 23 of the pipe connector 11 of the third embodiment, the connection direction of the two pipes 101 (101A, 101B) using this follows the pipe connection method of the third embodiment illustrated in Figure 8.

[0149] 3. Effects The membrane portion 23 of the first to third embodiments all has a curved shape when viewed in cross section, and therefore is easily bent in both the axial direction A and the radial direction R. This makes it possible to improve the eccentricity tracking ability of the two pipes 101 (101A, 101B) connected by the pipe connector 11 in both the axial direction A and the radial direction R.

[0150] [Modifications] Various embodiments have been described, but the present invention is not limited to these embodiments and various modifications and variations are possible.

[0151] DESCRIPTION OF SYMBOLS 11 Pipe connector 21 Elastic body 22 Connection portion 22A Connection portion (one connection portion) 22B Connection portion (other connection portion) 23 Membrane portion 24A Sealing portion 24B Sealing portion 24C1 Sealing portion 24C2 Sealing portion 24D1 Sealing portion 24D2 Sealing portion 31 First reinforcing ring 32 First cylindrical portion 33 First flange 41 Second reinforcing ring 42 Second cylindrical portion 43 Second flange 51 Reinforcing member 52 Coil spring 53 Base fabric 101 Pipe 101A Pipe (one pipe) 101B Pipe (other pipe) 201 First jig 211 Second jig 221 Jig d1, d2, d6 Inner diameter d3 to d5, d7 Outer diameter A Axial direction E1 End E2 End ES1 End face ES2 End face R Radial direction S1 Step S2 Step X Axis passing through the center of the pipe connector Y Axis passing through the center of one pipe Z Axis passing through the center of the other pipe

Claims

1. A pipe connector interposed between two pipes arranged in series facing each other in the axial direction to connect the two pipes, comprising: a rubber elastic body having connection parts at both ends that fit into one of the pipes and the other of the pipes, with a flexible membrane part integrally provided between the two connection parts, and with a sealing part that seals the pipes, which is integrally provided with the connection part; a first reinforcing ring embedded in one of the connection parts that fits into one of the pipes, the first reinforcing ring having a first tubular part and a first flange that are more rigid than the elastic body; and a second reinforcing ring embedded in the other connection part that fits into the other pipe, the second reinforcing ring having a second tubular part and an outwardly facing second flange that are more rigid than the elastic body, the first flange receiving the force of a jig in a direction from the other connection part toward the one connection part, and the second flange receiving the force of a jig in a direction from the one connection part toward the other connection part at the outer periphery of the elastic body.

2. A pipe connector as set forth in claim 1, wherein the first flange is an inward flange that receives the axial force of a jig inserted into the inside of the elastic body from the side of the other connection portion.

3. A piping connector as described in claim 2, wherein the first flange is provided at the end of the first tubular portion which is the leading side in the fitting direction to the one of the piping, and the one of the connection portions has a sealing portion on its outer surface which seals the inner surface of the one of the piping which fits onto its outer periphery.

4. A piping connector as described in claim 2, wherein the first flange is provided at the end of the first tubular portion that is rearward in the direction of fitting into the one of the piping, and the one of the connection portions has on its inner surface the sealing portion that seals the outer surface of the one of the piping that fits into its inner side.

5. A piping connector as described in claim 2, wherein the sealing portion is located at one or both of the end face of the one connection portion, at a position axially coinciding with the first tubular portion, and the end face of the other connection portion, at a position axially coinciding with the second tubular portion.

6. A piping connector as described in claim 2, wherein the sealing portion is arranged on either or both of a portion of rubber covering the first flange that faces the one pipe and a portion of rubber covering the second flange that faces the other pipe.

7. A pipe connector as set forth in claim 2, wherein a diameter of a fitting portion of said one connection part for said one pipe and a diameter of a fitting portion of said other connection part for said other pipe are the same.

8. A piping connector as described in claim 1, wherein the first flange is an outward flange that receives the axial force of a jig inserted into the membrane portion from a direction perpendicular to the axial direction.

9. A piping connector as described in claim 8, wherein the first flange is provided at the end of the first tubular portion that is on the rear side in the fitting direction to the one of the piping, and the one of the connection portions has a sealing portion on its outer surface that seals the inner surface of the one of the piping that fits onto its outer periphery.

10. A piping connector as described in claim 8, wherein the sealing portion is located at one or both of the following positions on the end face of the one connection portion that coincides with the first tubular portion in the axial direction: and / or the end face of the other connection portion that coincides with the second tubular portion in the axial direction.

11. A piping connector as described in claim 8, wherein the sealing portion is arranged on either or both of a portion of the rubber covering the first flange that faces the one pipe and a portion of the rubber covering the second flange that faces the other pipe.

12. The pipe connector according to claim 8, wherein a diameter of a fitting portion of said one connection part for said one pipe and a diameter of a fitting portion of said other connection part for said other pipe are the same.

13. The pipe connector according to claim 1, wherein a reinforcing member is embedded in the membrane portion.

14. The pipe connector according to claim 13, wherein the reinforcing member is a coil spring that expands and contracts in the axial direction.

15. The pipe connector according to claim 13, wherein the reinforcing member is a base fabric having a cylindrical shape.

16. The pipe connector according to claim 1, wherein the membrane portion has a shape in which the central portion has a smaller diameter than both end portions.

17. The pipe connector according to claim 1, wherein the membrane portion has a shape in which the central portion has a larger diameter than both end portions.

18. The pipe connector according to claim 1, wherein the membrane portion has a bellows shape that expands and contracts in the axial direction.

19. A pipe connecting method using a pipe connector comprising the steps of: preparing a pipe connector as defined in any one of claims 2 to 7; inserting a first jig having a diameter overlapping with the first flange in the axial direction into the inside of the elastic body from the side of the other connection portion; aligning the one pipe and the one connection portion so that they fit together, pushing in the first jig to pressurize the first flange and connect the one pipe and the one connection portion; removing the first jig; inserting a circular arc-shaped second jig into the membrane portion of the elastic body in a direction perpendicular to the axial direction; aligning the other pipe and the other connection portion so that they fit together, pressing the second flange with the second jig to connect the other pipe and the other connection portion; and removing the second jig.

20. A pipe connecting method using a pipe connecting device, comprising the steps of: preparing a pipe connecting device as defined in any one of claims 8 to 12; inserting the arc-shaped jig into the membrane portion in a direction perpendicular to the axial direction; applying pressure to the first flange with the jig while aligning the one pipe and the one connection portion so that they fit together, thereby connecting the one pipe and the one connection portion; applying pressure to the second flange with the jig while aligning the other pipe and the other connection portion so that they fit together, thereby connecting the other pipe and the other connection portion; and removing the jig.