JP2016050625A - Flexible Tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrict an extension and retraction of a bellows pipe without using any interlock pipe at a flexible tube.SOLUTION: When connecting cylinders 13a, 13b at both ends of a bellows pipe 13 are fixed to outer circumferences of an upstream pipe 11 and a downstream pipe 12 and each of a pair of restricting cylinders 15, 16 enclosing the bellows pipe 13 except the connecting cylinders 13a, 13b is fixed at outer circumferences of the upstream side pipe 11 and the downstream side pipe 12 in such a way that a clearance 14 is formed at a part between it and the outer circumference of the bellows pipe 13 and that the inner ends of the bellows pipe 13 along its axial direction are oppositely faced against to each other, they are formed into a cylindrical shape by metallic net material and at the same time both end portions of a net-like connecting cylinder 17 covering a pair of restricting cylinders 15, 16 are fixed to the outer circumferences of the upstream side pipe 11 and the downstream side pipe 12, and a ring member 18 is fitted at the outer circumference of the net-like connecting cylinder 17 at a position corresponding to a location between the opposing ends of a pair of restricting cylinders 15, 16.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a flexible tube that connects an upstream pipe and a downstream pipe.

  Patent Documents 1 and 2 and the like are known in which a flexible tube is provided in an exhaust system of an internal combustion engine so as to attenuate vibrations from the internal combustion engine.

Japanese Patent No. 4815522 Japanese Patent No. 399470

  By the way, in the flexible tube effective for vibration absorption, a mechanism for restricting expansion and contraction of the bellows pipe connecting the upstream pipe and the downstream pipe is necessary. A flexible tube is configured so as to include an outer blade that covers and an interlock pipe disposed inside the bellows pipe. However, the interlock pipe is a spiral pipe having an S-shaped cross section, and requires high-precision processing, so that the manufacturing process is complicated and expensive, and it becomes heavy. Further, the interlock pipe has a structure in which two pipe members are engaged with each other, and an abnormal noise may be generated when the two pipe members are contacted in the axial direction and the radial direction, thereby preventing the occurrence of the abnormal noise. Therefore, a dedicated design that changes the setting depending on the internal combustion engine to be applied is required. Furthermore, in the flexible tube disclosed in Patent Documents 1 and 2, the outer outer blade is in contact with the bellows tube, and when an excessive load is applied, the bellows tube may be deformed by the friction. .

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a flexible tube that can regulate expansion and contraction of a bellows tube without using an interlock tube.

  In order to achieve the above object, the present invention provides a flexible tube connecting an upstream pipe and a downstream pipe, each of which has a connecting cylindrical portion fixed to the outer periphery of the upstream pipe and the downstream pipe at both ends. Surrounding the bellows pipe so as to create a gap between the bellows pipe and the outer periphery of the bellows pipe at a portion excluding the connecting tube portion, and facing the inner end portions along the axial direction of the bellows pipe A pair of regulating cylinders fixed to the outer peripheries of the upstream pipe and the downstream pipe, respectively, and a cylindrical shape made of a metal net material and covering the pair of regulating cylinders and the upstream side A net-like connecting cylinder whose both ends are fixed to the outer circumference of the pipe and the downstream pipe, and a ring member fitted to the outer circumference of the net-like connecting cylinder at a position corresponding to between the opposing ends of the pair of regulating cylinders Prepare The the first feature.

  According to the present invention, in addition to the configuration of the first feature, the connecting cylinder part at both ends of the bellows pipe, the outer end part of the pair of regulating cylinders along the axial direction of the bellows pipe, and the mesh-like connection A second feature is that both ends of the tube are welded to the outer periphery of the upstream side tube and the downstream side tube together with ring-shaped pressing members surrounding both ends of the mesh-like connecting tube.

  Further, in the present invention, in addition to the configuration of the first or second feature, a part of the upstream pipe and the downstream pipe is inserted into the other of the upstream pipe and the downstream pipe. A third feature is that the small-diameter pipe portion is integrally provided.

  According to the first feature of the present invention, the pair of regulating cylinders that surround the bellows pipe and have the inner end portions along the axial direction of the bellows pipe facing each other are arranged on the outer circumference of the upstream pipe and the downstream pipe. Ring members corresponding to the gap between the opposing ends of the pair of regulating cylinders on the outer circumference of the mesh-like coupling cylinder that is fixed respectively and covers the pair of regulating cylinders and both ends are fixed to the outer circumference of the upstream pipe and the downstream pipe. Therefore, the contraction direction of the bellows pipe can be controlled by the axially inner end portion of the restriction tube being in contact with each other via a part of the mesh-like connection tube and the ring member. The restriction | limiting of the expansion | extension direction of a pipe | tube is regulated by a mesh-like connection cylinder. Therefore, it is not necessary to use an expensive and complicated interlock mechanism, and a flexible tube that is lightweight and inexpensive can be provided. Moreover, the pair of regulating cylinders surrounds the bellows pipes so that a gap is formed between the outer circumference of the bellows pipes except for the coupling cylinder part. The bellows pipe is not damaged by friction. In addition, since no abnormal noise is generated due to the interlock mechanism, a dedicated design for changing the setting depending on the internal combustion engine to be applied is unnecessary, and versatility is improved.

  Further, according to the second feature of the present invention, the connecting tube portions at both ends of the bellows tube, the outer end portions of the pair of regulating tubes, and both ends of the mesh-like connecting tube are upstream of the ring-shaped pressing member. Since it is welded to the outer periphery of the pipe and the downstream pipe, the bellows pipe, the pair of regulating cylinders, and the net-like connecting cylinder can be simultaneously fixed to the outer circumferences of the upstream pipe and the downstream pipe, while taking into account the bending allowance. Manufacturing becomes easy.

  Furthermore, according to the third feature of the present invention, since a part of the small-diameter pipe portion provided integrally with one of the upstream pipe and the downstream pipe is inserted into the other of the upstream pipe and the downstream pipe, A part of the pipe portion and the other of the upstream side pipe and the downstream side pipe overlap in the radial direction, and heat damage can be prevented with a light and simple structure. From the upstream side pipe to the downstream side pipe, It is possible to smooth the gas flow and suppress the generation of turbulent flow.

It is a side view which shows a part of exhaust system of an internal combustion engine. It is a side view of a flexible tube. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. First, in FIG. 1, a cylinder head 5 of an internal combustion engine E mounted on a vehicle has a plurality of exhausts provided in the cylinder head 5. An exhaust manifold 7 corresponding to the port 6 is connected. A catalytic converter 9 is connected to the downstream end of the exhaust manifold 7 via an exhaust pipe 8, and a flexible tube 10 according to the present invention is interposed in the exhaust pipe 8. That is, the flexible tube 10 is provided between the upstream pipe portion 8a on the exhaust manifold 7 side of the exhaust pipe 8 and the downstream pipe portion 8b on the catalytic converter 9 side.

  Referring to FIGS. 2 and 3 together, the flexible tube 10 is connected to the upstream pipe 11 that is coaxially coupled to the upstream pipe 8 a of the exhaust pipe 8 and the downstream pipe 8 b of the exhaust pipe 8. A bellows pipe 13 having connecting cylindrical portions 13a and 13b fixed to the outer periphery of the downstream pipe 12 connected coaxially at both ends, and an outer periphery of the bellows pipe 13 in a portion excluding the connecting cylindrical portions 13a and 13b. An outer periphery of the upstream pipe 11 and the downstream pipe 12 is formed so as to surround the bellows pipe 13 with a gap 14 therebetween and to make inner end portions along the axial direction of the bellows pipe 13 face each other. The upstream pipe 11 and the downstream pipe 1 are formed in a cylindrical shape with a pair of regulating cylinders 15 and 16 respectively fixed to the pipes and covered with the pair of regulating cylinders 15 and 16. And a ring member 18 fitted on the outer periphery of the mesh-like connecting cylinder 17 at a position corresponding to a position between the opposed ends of the pair of restriction cylinders 15 and 16. Prepare.

  The bellows tube 13 has a cylindrical shape that connects the connecting tube portions 13a and 13b at both ends thereof, a pair of bellows portions 13c and 13d respectively connected to the connecting tube portions 13a and 13b, and the bellows portions 13c and 13d. The central connecting portion 13e is integrally formed.

  The pair of restriction cylinders 15 and 16 are small-diameter cylindrical parts 15a and 16a surrounding the connecting cylinder parts 13a and 13b of the bellows pipe 13, and large bellows parts 13c and 13d of the bellows pipe 13 coaxially. The diameter cylindrical portions 15b, 16b, the small diameter cylindrical portions 15a, 16a and the large diameter cylindrical portions 15b, 16b are integrally connected to each other, and on the opposite side of the tapered cylindrical portions 15c, 16c. Tapered flange portions 15d and 16d projecting radially inward from the ends of the large diameter cylindrical portions 15b and 16b are integrally formed, and the large diameter cylindrical portions 15b and 16b are formed as the bellows. The bellows portions 13c and 13d of the tube 13 are surrounded so that a gap 14 is formed between the bellows portions 13c and 13d.

  The net-like connecting cylinder 17 covers the pair of regulating cylinders 15 and 16 so as to contact the outer surfaces of the pair of regulating cylinders 15 and 16. The cross-sectional shape of the ring member 18 is, for example, a substantially U-shape that opens outward, and the central portion in the axial direction of the mesh-like connecting cylinder 17 is between the opposing ends of the pair of regulating cylinders 15 and 16. In other words, the ring member 18 is fitted on the outer periphery of the mesh-like connecting cylinder 17 so that a part of the restriction cylinders 15 and 16 enters between the flange portions 15d and 16d.

  When the ring member 18 is fitted on the outer periphery of the mesh-like connecting cylinder 17, the ring member 18 having a slightly larger diameter than the large-diameter cylindrical portions 15 b and 16 b in the regulation cylinders 15 and 16 is provided in a natural state where no external force acts. Is slid in the axial direction and covered with the central portion in the axial direction of the mesh-like connecting cylinder 17, or in a natural state where no external force acts, the large-diameter cylindrical portion 15b in the restriction cylinders 15 and 16 A C-shaped member having a diameter slightly larger than 16b may be slid in the axial direction so as to reduce the diameter in a state where the member is covered on the central portion in the axial direction of the mesh-like connecting cylinder 17, and the contact portion may be welded.

  The connecting tube portions 13a and 13b at both ends of the bellows tube 13, the outer ends of the pair of restricting tubes 15 and 16 along the axial direction of the bellows tube 13, that is, the small diameter tube portions 15a and 16a, and the mesh connection Both ends of the cylinder 17 are welded to the outer circumferences of the upstream pipe 11 and the downstream pipe 12 together with ring-shaped pressing members 19 and 20 surrounding both ends of the mesh-like connecting cylinder 17, The holding members 19 and 20 are formed so that the cross-sectional shape thereof is substantially L-shaped.

  In addition, one of the upstream side pipe 11 and the downstream side pipe 12, for example, the upstream side pipe 11 is partially inserted into the other side of the upstream side pipe 11 and the downstream side pipe 12, for example, the downstream side pipe 12. The small-diameter pipe portion 11a is integrally provided, and in this embodiment, the small-diameter pipe portion 11a includes a tapered cylindrical portion 11aa having a diameter that decreases toward the downstream pipe 12, and the tapered cylindrical portion 11aa. The cylindrical portion 11ab is coaxially connected to the small-diameter end, and a part of the cylindrical portion 11ab is radially overlapped with the upstream end portion of the downstream tube 12 in the radial direction. Inserted into the section.

  Next, the operation of this embodiment will be described. The flexible tube 10 includes a bellows pipe 13 having connection cylinder parts 13a and 13b fixed to the outer circumferences of the upstream pipe 11 and the downstream pipe 12 at both ends, The portions other than the connecting cylinder portions 13a and 13b surround the bellows tube 13 so that a gap 14 is formed between the outer periphery of the bellows tube 13 and the inner end portions along the axial direction of the bellows tube 13 are mutually connected. A pair of restriction cylinders 15 and 16 fixed to the outer circumferences of the upstream side pipe 11 and the downstream side pipe 12 so as to face each other, and a pair of restriction cylinders formed in a cylindrical shape by a metal net member. A mesh-like connecting cylinder 17 that covers both ends of the upstream pipe 11 and the downstream pipe 12 and covers both ends of the upstream pipe 11 and the downstream pipe 12, and a pair of the regulating cylinders 15 and 16. And a ring member 18 fitted on the outer periphery of the mesh-like connecting cylinder 17 at a position corresponding to the part, so that the inner ends in the axial direction of the regulating cylinders 15 and 16 are located between them. The contraction direction of the bellows tube 13 can be regulated by abutting through the part and the ring member 18, and the regulation of the extension direction of the bellows tube 13 is regulated by the mesh-like connecting cylinder 17. Therefore, it is not necessary to use an expensive and complicated interlock mechanism, and the lightweight and inexpensive flexible tube 10 can be provided. In addition, the pair of regulating cylinders 15 and 16 surround the bellows pipe 13 so that a gap 14 is formed between the outer circumference of the bellows pipe 13 except for the coupling cylinder portions 13a and 13b. The net-like connecting cylinder 17 that covers 15 and 16 does not come into contact with the bellows pipe 13, and the bellows pipe 13 is not damaged by friction. In addition, since no abnormal noise is generated due to the interlock mechanism, a dedicated design for changing the setting according to the internal combustion engine E to be applied is unnecessary, and versatility is improved.

  Also, the connecting tube portions 13 a and 13 b at both ends of the bellows tube 13, the outer end portions of the pair of regulating tubes 15 and 16 along the axial direction of the bellows tube 13, and both end portions of the mesh-like connecting tube 17 Are welded to the outer periphery of the upstream side pipe 11 and the downstream side pipe 12 together with the ring-shaped pressing members 19 and 20 surrounding both ends of the mesh-like connecting cylinder 17, so that the bellows pipe 13. The pair of regulating cylinders 15 and 16 and the net-like connecting cylinder 17 can be simultaneously fixed to the outer peripheries of the upstream side pipe 11 and the downstream side pipe 12, respectively, which facilitates manufacture.

  Furthermore, one of the upstream side pipe 11 and the downstream side pipe 12 (upstream side pipe 11 in this embodiment) is connected to the other side of the upstream side pipe 11 and the downstream side pipe 12 (downstream side pipe 12 in this embodiment). ) Is provided integrally with a small diameter pipe portion 11a so that a part of the small diameter pipe portion 11a and the other of the upstream side pipe 11 and the downstream side pipe 12 overlap in the radial direction. It is possible to prevent heat damage with a light and simple structure, smooth the flow of exhaust gas from the upstream pipe 11 to the downstream pipe 12, and suppress the occurrence of turbulent flow and suppress the reduction of exhaust efficiency. can do.

  In addition, by making the central portion in the axial direction of the bellows tube 13 into a cylindrical shape instead of a bellows shape, it is possible to contribute to a reduction in the diameter of the entire flexible tube 10 while avoiding contact of the mesh-like connecting portion 17 with the bellows tube 13. it can.

  In the above-described embodiment, the overlapping portion in the radial direction of the upstream pipe 11 and the downstream pipe 12 is the axial end of the bellows pipe 13, but the upstream pipe at the axial center of the bellows pipe 13. 11 and the downstream pipe 12 may be overlapped in the radial direction.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. Is possible.

DESCRIPTION OF SYMBOLS 10 ... Flexible tube 11 ... Upstream side pipe 11a ... Small diameter pipe part 12 ... Downstream side pipe 13 ... Bellows pipes 13a, 13b ... Connection cylinder part 14 ... Gap 15, 16 ... Regulating cylinder 17 ... Reticulated connecting cylinder 18 ... Ring members 19, 20 ... Pressing members

Claims (3)

  A flexible tube connecting the upstream side pipe (11) and the downstream side pipe (12), which is connected to the outer circumference of the upstream side pipe (11) and the downstream side pipe (12) (13a, 13b) The bellows pipe (13) is formed between the bellows pipe (13) at both ends and the outer periphery of the bellows pipe (13) except for the connecting cylinder part (13a, 13b). (13) is fixed to the outer circumferences of the upstream pipe (11) and the downstream pipe (12) so that the inner ends along the axial direction of the bellows pipe (13) are opposed to each other. The upstream pipe (11) and the downstream pipe are formed in a cylindrical shape by a pair of regulating cylinders (15, 16) and the pair of regulating cylinders (15, 16). (12) outer circumference A ring-shaped connecting cylinder (17) to which both ends are fixed, and a ring member that is fitted to the outer periphery of the mesh-shaped connecting cylinder (17) at a position corresponding to between the opposing end portions of the pair of regulating cylinders (15, 16). A flexible tube comprising (18).   The connecting tube portions (13a, 13b) at both ends of the bellows tube (13), the outer ends of the pair of regulating tubes (15, 16) along the axial direction of the bellows tube (13), and the mesh The upstream side pipe (11) and the downstream side pipe (12) together with ring-shaped pressing members (19, 20) in which both ends of the connecting cylinder (17) surround both ends of the mesh-like connecting cylinder (17). The flexible tube according to claim 1, wherein the flexible tube is welded to an outer periphery of the flexible tube.   A small-diameter pipe portion (one part of which is inserted into the other of the upstream pipe (11) and the downstream pipe (12) into one of the upstream pipe (11) and the downstream pipe (12). The flexible tube according to claim 1 or 2, wherein 11a) is provided integrally.

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