JP2015063984A - Flexible joint for exhaust device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To certainly seal exhaust gas, and to effectively absorb vibrations by enabling exhaust pipes to smoothly carry out angle displacement due to the vibrations.SOLUTION: A flexible joint for an exhaust device includes: a flexible joint 12 for airtightly coupling an exhaust pipe 4b on a downstream side and a relay pipe 11; a pair of flange members 16 and 17 respectively provided on the exhaust pipe and the relay pipe; a bolt 19 and a nut 20 provided so as to penetrate the pair of the flange members, and regulating the separation of the pair of the flanges; a spring 21 for energizing the pair of the flange members in a separating direction; and an interposing member 41 interposed between a seat surface 43 formed around a through-hole 42 of the bolt 19 and a head portion 35 of the bolt 19 in one flange member 16. The seat surface is formed to be a spherical recessed surface, and an abutting surface 46 of the interposing member abutting on the seat surface is formed to be a spherical projecting surface. The interposing member slides to the seat surface.

Description

  The present invention relates to a flexible joint that is provided in an exhaust system of an engine and that couples a pair of passage members forming an exhaust passage so as to be capable of relative angular displacement, and absorbs vibration transmitted from the engine side. Is.

  An exhaust system of an automobile engine is provided with a flexible joint as a vibration absorbing device that absorbs vibration transmitted from the engine side. This flexible joint connects exhaust pipes in a state where relative angular displacement between the exhaust pipes (relative displacement in the bending direction) is possible, and vibrates due to the relative angular displacement between the exhaust pipes. In addition to absorbing vibrations caused by the engine, it also has a function to prevent damage to the exhaust system when external force caused by vibrations generated in the vehicle body during travel acts on the exhaust system. .

  Conventionally, as a flexible joint provided in such an exhaust device, a seat surface that contacts a seal member that seals exhaust gas is formed in a spherical shape, and a contact of the seal member that contacts the spherical seat surface A so-called spherical joint is known in which a surface is formed in a spherical shape and a seal member slides along a spherical seating surface, thereby enabling relative angular displacement between exhaust pipes (patent) Reference 1).

Japanese Patent No. 4094423

  However, in the conventional technique described above, in order to reliably seal the exhaust gas, it is necessary to increase the biasing force of the spring in order to increase the surface pressure of the seal member. Then, the frictional force between the seal member and the seat surface increases, and the seal member becomes difficult to slide with respect to the seat surface, so that the relative angular displacement between the exhaust pipes is not smoothly performed. For this reason, vibration transmitted from the engine side cannot be sufficiently absorbed, and there is a problem that it is difficult to achieve both sealing performance and vibration absorption performance.

  The present invention has been devised to solve such problems of the prior art, and its main purpose is to reliably seal the exhaust gas and to make the relative relationship between the exhaust pipes associated with vibration. It is an object of the present invention to provide a flexible joint configured to smoothly absorb angular vibrations by smoothly performing angular displacement.

  1st invention made | formed in order to solve the said subject connected a pair of passage members (downstream exhaust pipe 4b, relay pipe 11) which form an exhaust passage so that relative angular displacement was possible, A flexible joint for an exhaust device that absorbs vibration transmitted from the engine (2) side, wherein the pair of passage members are hermetically coupled to the flexible pipe (12) and the pair of passage members, respectively. A restriction that restricts the separation between the pair of flanges provided in a form that penetrates the pair of flanges (the first flange member 16 and the second flange member 17) and the pair of flanges. A connecting shaft (shaft portion 36) having a portion (head portion 35, nut 20) at both ends, an elastic member (spring 21) for biasing a pair of flanges in the separating direction, and the connecting shaft at one flange Around the through hole (42) An interposition member (41) interposed between the seating surface (43) formed on the surface and the restricting portion (head 35), and the seating surface is formed into a spherical concave surface. At the same time, the contact surface (46) of the intervention member that contacts the seat surface is formed as a spherical convex surface, and the intervention member slides relative to the seat surface.

  According to this, the relative angular displacement of a pair of passage members becomes possible because the interposition member slides with respect to the seating surface. Further, since the pair of passage members are hermetically connected by the flexible pipe, the exhaust gas can be reliably sealed. And since this sealing performance does not depend on the urging | biasing force of an elastic member, the urging | biasing force of an elastic member can be adjusted freely. For this reason, if the biasing force of the elastic member is set to be small, the frictional force between the seating surface and the abutting surface of the interposition member can be reduced. The angular displacement can be smoothly performed to effectively absorb the vibration.

  Moreover, when a large external force acts on the exhaust pipes in the bending direction, displacement of the pair of flanges in the proximity direction is suppressed by an urging force that is increased by compressing the elastic member, and when a larger external force acts, Since the displacement in the proximity direction of the pair of flanges is restricted at the compression limit, it is possible to prevent excessive angular displacement between the exhaust pipes, thereby preventing the flexible pipe from being damaged.

  In the second invention, a pair of passage members (downstream exhaust pipe 4b, relay pipe 11) forming an exhaust passage are connected to each other so as to be capable of relative angular displacement, and transmitted from the engine (2) side. A flexible joint for an exhaust device that absorbs vibrations, a flexible pipe (12) for air-tightly connecting a pair of the passage members, and a pair of flanges respectively provided on the pair of the passage members (First flange member 16, second flange member 17) and a restricting portion (head 35, nut) that is provided so as to penetrate the pair of flanges and restricts the separation between the pair of flanges. 20) at both ends, and a resilient member (spring 21) that urges the pair of flanges in the separating direction, and one of the flanges has a through hole ( 42) The bearing surface formed around 43) is formed on a spherical concave surface, and the contact surface (54) of the restricting portion (head 35) that contacts the seat surface is formed on a spherical convex surface. On the other hand, the restriction portion is configured to slide.

  According to this, similarly to the first invention, the exhaust gas can be reliably sealed, and the relative angular displacement between the exhaust pipes accompanying the vibration can be smoothly performed to effectively absorb the vibration. Furthermore, since the number of parts is reduced, the number of manufacturing steps can be reduced.

  Moreover, 3rd invention sets it as the structure by which the part which forms the said contact surface of the said interposed member was formed with the material which reduces the frictional force between the said seat surface and the said contact surface.

  According to this, since the frictional force between the seating surface and the contact surface is reduced, the interposed member slides smoothly along the seating surface, and the relative angle between the exhaust pipes due to vibration is increased. Displacement can be performed more smoothly, and the vibration absorption effect can be enhanced.

  According to a fourth aspect of the present invention, there is provided a friction reducing material layer (55) by applying a material that reduces a frictional force between the seating surface and the contact surface to at least one of the seating surface and the contact surface. ) Is formed.

  According to this, since the frictional force between the seating surface and the contact surface becomes small, the regulating portion slides smoothly along the seating surface, and the relative angular displacement between the exhaust pipes due to vibrations Can be performed more smoothly to enhance the vibration absorption effect.

  As described above, according to the present invention, the interposition member slides with respect to the seating surface, thereby allowing a relative angular displacement between the pair of passage members. Further, since the pair of passage members are hermetically connected by the flexible pipe, the exhaust gas can be reliably sealed. And since this sealing performance does not depend on the urging | biasing force of an elastic member, the urging | biasing force of an elastic member can be adjusted freely. For this reason, if the biasing force of the elastic member is set to be small, the frictional force between the seating surface and the abutting surface of the interposition member can be reduced. The angular displacement can be smoothly performed to effectively absorb the vibration.

It is a side view which shows the exhaust system of the motor vehicle concerning 1st Embodiment. It is a perspective view of the flexible joint shown in FIG. It is a top view of the flexible joint shown in FIG. It is sectional drawing of the flexible joint shown in FIG. It is sectional drawing which shows the principal part of the flexible joint shown in FIG. It is typical sectional drawing which shows the operation | movement condition of the flexible joint shown in FIGS. It is sectional drawing similar to FIG. 5 which shows the principal part of the flexible joint concerning 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a side view showing an exhaust system of an automobile according to the first embodiment. Under the floor of the vehicle body 1, an exhaust pipe 4 that guides exhaust gas discharged from the engine 2 to the tail pipe 3 at the rear end of the vehicle body extends so as to extend substantially in the longitudinal direction of the vehicle body. In the middle, catalytic converters 5 and 6 and silencers 7 and 8 are provided in order to purify the exhaust gas and to mute and release it into the atmosphere.

  Further, in the vicinity of the downstream of the catalytic converter 5 provided in the immediate vicinity of the engine 2, vibrations transmitted from the engine 2 via the catalytic converter 5 and the upstream exhaust pipe 4a are absorbed and the downstream exhaust pipe 4b is absorbed. A flexible joint 9 for suppressing vibration is provided.

  FIG. 2 is a perspective view of the flexible joint 9 shown in FIG. FIG. 3 is a top view of the flexible joint 9 shown in FIG. 4 is a cross-sectional view of the flexible joint 9 shown in FIG.

  As shown in FIG. 4, the flexible joint 9 includes a relay pipe (the other passage member) 11, a flexible pipe 12, a cover member 13, a diameter expanding member 14, a ring member 15, and a first flange member. (One flange) 16, a second flange member (the other flange) 17, a third flange member 18, a bolt 19 and a nut 20, and a spring (elastic member) 21.

  The relay pipe 11 is disposed between the pair of exhaust pipes 4a and 4b, has a circular cross section perpendicular to the center line C, and is formed in a tapered shape that gradually decreases in diameter from the upstream side toward the downstream side. Yes. Accordingly, it is possible to avoid the relay pipe 11 from interfering with the flexible pipe 12 when a relative angular displacement occurs between the pair of exhaust pipes 4a and 4b.

  The flexible pipe 12 is an airtight connection between the relay pipe 11 and the downstream exhaust pipe (one passage member) 4b. The cross section perpendicular to the center line has a circular shape and has an accordion structure in any direction. It has a bellows part 22 that can be deformed, and straight pipe parts 23 and 24 provided at both ends of the bellows part 22. The flexible pipe 12 seals the exhaust gas, and the flexure deformation and expansion / contraction deformation of the bellows portion 22 cause relative angular displacement and axial displacement between the relay pipe 11 and the downstream exhaust pipe 4b. Permissible.

  The cover member 13 is provided so as to cover the outer side of the flexible tube 12 and protects the flexible tube 12, has a straight cylindrical shape, and has a large number of small holes.

  The diameter-expanding member 14 fixes one end side of the flexible pipe 12 and the cover member 13 to the exhaust pipe 4b on the downstream side, and the cross section perpendicular to the center line has a circular shape and corresponds to the outer diameter of the exhaust pipe 4b. The small-diameter portion 25, the large-diameter portion 26 corresponding to the outer diameter of the cover member 13, and the connecting portion 27 that connects the small-diameter portion 25 and the large-diameter portion 26. The diameter-expanding member 14 is attached so that the straight pipe portion 23 of the flexible pipe 12 is sandwiched between the small-diameter portion 25 and the exhaust pipe 4b. Fixed. Further, the cover member 13 is attached to the large-diameter portion 26 so as to be fitted, and the cover member 13 and the diameter-expanding member 14 are fixed by a weld bead 29 (see FIG. 2).

  The ring member 15 fixes the other end of the flexible pipe 12 to the relay pipe 11 and has a substantially U-shaped cross section. The ring member 15 is attached so as to sandwich the straight pipe portion 23 of the flexible pipe 12 between the ring pipe 15 and the other end side of the ring member 15 and the flexible pipe 12 is fixed to the relay pipe 11 by a weld bead 30. .

  The first flange member 16 is attached to the other end side of the cover member 13 in a fitted state, and the first flange member 16 and the cover member 13 are fixed by a weld bead 31 (see FIG. 2). Thereby, the first flange member 16 is integrated with the exhaust pipe 4b on the downstream side through the cover member 13 and the diameter-expanding member 14.

  The second flange member 17 is attached to the other end side of the relay pipe 11 in a fitted state, and the second flange member 17 and the relay pipe 11 are fixed by a weld bead 32.

  The third flange member 18 is attached to the upstream side exhaust pipe 4a in a fitted state, and the third flange member 18 is fixed to the upstream side exhaust pipe 4a by a weld bead 33.

  The bolt 19 and the nut 20 fasten the second flange member 17 and the third flange member 18 and restrict the separation of the first flange member 16 and the second flange member 17. Is engaged with the first flange member 16, and the shaft portion 36 is provided so as to penetrate the first flange member 16, the second flange member 17, and the third flange member 18. Two sets of the bolt 19 and the nut 20 are provided at symmetrical positions around the center line C (see FIG. 2).

  The bolt 19 includes a flange 37 on the head portion 35 and a flange 38 on the shaft portion (connection shaft) 36. The flange 38 of the shaft portion 36 engages with the second flange member 17, and the second flange member 17 and the third flange member 18 are sandwiched between the flange 38 and the nut 20, so that both are fastened. Thus, the upstream exhaust pipe 4a and the relay pipe 11 are integrated.

  The spring 21 is constituted by a coil spring, the shaft portion 36 of the bolt 19 is inserted therein, and is attached in a compressed state between the first flange member 16 and the second flange member 17. The flange member 16 and the second flange member 17 are biased in the separating direction.

  FIG. 5 is a cross-sectional view showing a main part of the flexible joint 9 shown in FIG. An interposition member 41 is interposed between the first flange member 16 and the head portion 35 of the bolt 19. On the first flange member 16, a seat surface 43 with which the interposition member 41 abuts is formed around the through hole 42 of the bolt 19. The seat surface 43 is formed as a spherical concave surface.

  The interposed member 41 has a ring shape having a center hole 45. The interposed member 41 is externally mounted on the head portion 35 of the bolt 19, and the displacement to the side opposite to the shaft portion 36, that is, the displacement in the pull-out direction is regulated by the flange 37 of the head portion 35. The intervention member 41 has a contact surface 46 that contacts a seat surface 43 provided on the first flange member 16, and the contact surface 46 is complementary to the spherical seat surface 43. It is formed on a spherical convex surface.

  A required gap is secured between the shaft portion 36 of the bolt 19 and the through hole 42, and the bolt 19 can be displaced with respect to the seating surface 43 within a required range by this gap. Further, the contact surface 46 of the interposing member 41 is pressed against the seat surface 43 by the spring 21 that biases the first flange member 16 and the second flange member 17 in the separating direction.

  A portion of the interposed member 41 that forms the contact surface 46 is formed of a friction reducing material that reduces the frictional force between the seating surface 43 and the contact surface 46. As this friction reducing material, a material containing expanded graphite is suitable.

  6A and 6B are schematic cross-sectional views showing the operating state of the flexible joint 9 shown in FIGS. 2 to 5. FIG. 6A shows a neutral state and FIG. 6B shows a tilted state. .

  When a vibration that causes the upstream exhaust pipe 4a to tilt in the direction indicated by the arrow A in FIG. 2 is input from the upstream exhaust pipe 4a to the flexible joint 9 with respect to the downstream exhaust pipe 4b, As shown in FIG. 6B, each of the interposing members 41 slides along two seating surfaces 43 with which the interposing members 41 attached to the two bolts 19 abut on each other in the first flange member 16. Then, the upstream exhaust pipe 4a tilts with respect to the downstream exhaust pipe 4b about the straight line connecting the centers O of the spherical surfaces S that respectively form the two seating surfaces 43, and the upstream exhaust pipe The vibration transmitted from 4a is absorbed.

  In this case, when a large external force acts on the exhaust pipes 4 a and 4 b in the bending direction, the displacement of the first flange member 16 and the second flange member 17 in the proximity direction is caused by the biasing force that is increased by the compression of the spring 21. If the external force is suppressed and a larger external force is applied, the displacement of the first flange member 16 and the second flange member 17 in the proximity direction is restricted by the compression limit of the spring 21, so that an excessive angle is formed between the exhaust pipes 4a and 4b. The occurrence of displacement can be prevented, thereby preventing the flexible tube 12 (see FIG. 4) from being damaged.

  As described above, in the present embodiment, the interposition member 41 slides with respect to the seating surface 43, so that a relative angular displacement between the pair of exhaust pipes 4a and 4b becomes possible. Further, since the downstream exhaust pipe 4b and the relay pipe 11 are hermetically connected by the flexible pipe 12, the exhaust gas can be reliably sealed in the movable portion. Since the sealing performance does not depend on the urging force of the spring 21, the urging force of the spring 21 can be freely adjusted. For this reason, if the biasing force of the spring 21 is set small, the frictional force between the seating surface 43 and the contact surface 46 of the interposition member 41 can be reduced, whereby the exhaust pipe 4a, It is possible to smoothly absorb the vibration transmitted from the upstream side exhaust pipe 4a by smoothly performing the relative angular displacement between the 4b.

  In particular, in the present embodiment, since the portion that forms the contact surface 46 of the intervention member 41 is formed of a friction reducing material, the frictional force between the seat surface 43 and the contact surface 46 is reduced. The interposed member 41 slides smoothly along the seating surface 43, and the relative angular displacement between the exhaust pipes 4a and 4b due to vibration is more smoothly performed to enhance the vibration absorption effect. Can do.

(Second Embodiment)
FIG. 7 is a cross-sectional view similar to FIG. 5 showing the main part of the flexible joint 9 according to the second embodiment. The points not particularly mentioned here are the same as in the first embodiment.

  In the second embodiment, compared to the first embodiment shown in FIG. 5, the interposed member 41 is omitted, and the enlarged diameter portion 53 formed on the head portion 52 of the bolt 51 is a first flange. The member 16 is in direct contact with the seating surface 43, and the contact surface 54 of the enlarged diameter portion 53 is formed as a spherical convex surface complementary to the spherical seating surface 43.

  Further, a friction reducing material layer 55 that reduces the frictional force between the seating surface 43 and the contact surface 54 is formed on the contact surface 54 of the bolt 51. As the friction reducing material used here, for example, a synthetic resin such as a fluororesin, particularly a tetrafluoride resin is suitable, and such a friction reducing material is applied to the enlarged diameter portion 53 of the bolt 51 made of a metal material. Thus, the friction reducing material layer 55 is formed.

  Also in the second embodiment, as in the first embodiment, exhaust gas sealing is performed reliably, and the relative angular displacement between the exhaust pipes associated with vibration is smoothly performed to effectively absorb vibration. In addition, since the number of parts is reduced, the number of manufacturing steps can be reduced.

  In the second embodiment, since the friction reducing material layer 55 is formed on the contact surface 54 formed on the enlarged diameter portion 53 of the bolt 51, the friction between the seat surface 43 and the contact surface 54. Since the force is reduced, the head 52 of the bolt 51 slides smoothly along the seating surface 43, and the relative angular displacement between the exhaust pipes 4a and 4b due to vibration is more smoothly performed, thereby vibrating. Absorption effect can be enhanced.

  As mentioned above, although this invention was demonstrated based on specific embodiment, these embodiment is an illustration to the last, Comprising: This invention is not limited by these embodiment. Further, all the components of the flexible joint for exhaust device according to the present invention shown in the above embodiment are not necessarily essential, and can be appropriately selected as long as they do not depart from the scope of the present invention. .

  For example, in each embodiment, as shown in FIG. 4 and the like, the flange members 16 and 17 are arranged on the upstream side, and the flexible pipe 12 is arranged on the downstream side. It is also possible to reverse the upstream side and downstream side.

  Further, in each embodiment, as shown in FIG. 4 and the like, the spherical seat surface 43 and the interposition member 41 are provided on the head 35 side of the bolt 19, but on the contrary, on the nut 20 side. It is also possible to provide a spherical seating surface and an interposed member. Further, although the head portion 35 of the bolt 19 is disposed on the downstream side, the head portion 35 of the bolt 19 may be disposed on the upstream side. Moreover, you may make it use the both nut bolts which a nut screw | threads into the both ends of a bolt.

  In each embodiment, as shown in FIG. 4 and the like, the relay pipe 11 is provided between the upstream exhaust pipe 4a and the downstream exhaust pipe 4b. However, the relay pipe 11 and the second flange are provided. A configuration in which the member 17 is omitted is also possible. In this case, the flexible pipe 12 is provided so as to airtightly connect the upstream side exhaust pipe 4a and the downstream side exhaust pipe 4b, and in the upstream side exhaust pipe 4a, The tip may be configured to have a tapered shape similar to that of the relay pipe 11.

  Moreover, in each embodiment, as shown in FIG. 4 etc., the spring 21 comprised by the coil spring was employ | adopted as an elastic member which urges | biases a pair of flange members 16 and 17 to a separation direction, but this invention The elastic member is not limited to this, and may be composed of a spring other than the coil spring, rubber, or the like.

  In the first embodiment, the portion of the interposing member 41 that forms the contact surface 46 is formed of the friction reducing material. However, the entire interposing member 41 or the entire outer layer thereof is formed of the friction reducing material. You may make it do.

  In the second embodiment, the friction reducing material layer 55 is formed on the contact surface 54 of the bolt 51 by applying a friction reducing material such as a fluororesin. On the contrary, the first flange member A friction reducing material layer may be formed on the 16 seat surfaces 43. Further, a friction reducing material layer may be formed on both the seat surface 43 and the contact surface 54 of the bolt 51. Furthermore, the configuration shown in the second embodiment for forming the friction reducing material layer by applying the friction reducing material can be applied to the configuration of the first embodiment. That is, a friction reducing material layer by applying a friction reducing material may be formed on one or both of the contact surface 46 and the seating surface 43 of the intervention member 41 in the first embodiment.

  In the first embodiment, the contact surface 46 of the intervention member 41 is formed as a spherical convex surface that is complementary to the spherical seat surface 43, and in the second embodiment, the contact surface of the bolt 51. 54 is formed as a spherical convex surface complementary to the spherical seating surface 43, but the spherical seating surface and the spherical contact surface do not necessarily have to be complementary to each other. Even if the diameter of the spherical surface to be formed is slightly larger than the diameter of the spherical surface forming the contact surface, the contact surface can be smoothly slid along the seat surface.

2 Engine 4a Upstream exhaust pipe 4b Downstream exhaust pipe (one passage member)
9 Flexible joint 11 Relay pipe (other passage member)
12 Flexible pipe 16 First flange member (one flange)
17 Second flange member (the other flange)
18 Third flange member 19 Bolt 20 Nut (regulator)
21 Spring (elastic member)
35 Head (Regulation Department)
36 Shaft (Connecting shaft)
41 Interposition member 42 Through-hole 43 Seat surface 46 Contact surface 51 Bolt 52 Head 53 Expanded portion 54 Contact surface 55 Friction reducing material layer

Claims (4)

A pair of passage members forming an exhaust passage are connected so as to be relatively angularly displaceable, and a flexible joint for an exhaust device that absorbs vibration transmitted from the engine side,
A flexible pipe for airtightly connecting the pair of passage members;
A pair of flanges respectively provided on the pair of passage members;
A connecting shaft that is provided in a manner penetrating the pair of flanges and has a restricting portion that restricts the separation between the pair of flanges at both ends;
An elastic member for urging the pair of flanges in the separating direction;
An interposition member interposed between a seating surface formed around the through hole of the connecting shaft and the restricting portion in one of the flanges;
With
The seating surface is formed as a spherical concave surface, and the contact surface of the intervention member that contacts the seating surface is formed as a spherical convex surface, and the intervention member is formed with respect to the seating surface. A flexible joint for an exhaust device, characterized by sliding. A pair of passage members forming an exhaust passage are connected so as to be relatively angularly displaceable, and a flexible joint for an exhaust device that absorbs vibration transmitted from the engine side,
A flexible pipe for airtightly connecting the pair of passage members;
A pair of flanges respectively provided on the pair of passage members;
A connecting shaft that is provided in a manner penetrating the pair of flanges and has a restricting portion that restricts the separation between the pair of flanges at both ends;
An elastic member for urging the pair of flanges in the separating direction;
With
In one of the flanges, a seat surface formed around the through hole of the connecting shaft is formed as a spherical concave surface, and a contact surface of the restricting portion that contacts the seat surface is a spherical convex surface. The exhaust joint flexible joint, wherein the restricting portion slides relative to the seat surface.   2. The exhaust according to claim 1, wherein at least a portion of the intervention member that forms the contact surface is formed of a material that reduces a frictional force between the seat surface and the contact surface. Flexible joint for equipment.   The friction reducing material layer is formed by applying a material that reduces a frictional force between the seating surface and the contact surface to at least one of the seating surface and the contact surface. The flexible joint for exhaust apparatus according to claim 1 or 2.

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