JP5380045B2 - Pipe fitting - Google Patents

Description

  The present invention relates to a joint structure that interconnects an upstream exhaust pipe and a downstream exhaust pipe that form an exhaust passage or the like from a vehicle engine, and more particularly, an exhaust manifold connected to an FF horizontal engine; The present invention relates to a pipe joint that connects a downstream exhaust pipe so as to be relatively swingable.

  In general, in an exhaust system of a vehicle engine, an exhaust manifold (upstream exhaust pipe) connected to an exhaust port of the engine and an exhaust pipe on the downstream side thereof are connected to each other via a pipe joint.

This type of pipe joint has a spherical joint structure in many cases, and by allowing relative swinging between the exhaust manifold and the exhaust pipe, vibration caused by exhaust pulsation flowing in the exhaust system and road surface It absorbs and reduces vibrations caused by shock from the vehicle and bending stresses caused by various inertial forces associated with vehicle travel. A conventional pipe joint of this type includes a seat body having a spherical concave surface fixed to an end portion of one pipe, and a seal body having a spherical convex surface fixed to an end portion of the other pipe. The concave surface of the seat body and the convex surface of the seal body are slidably connected to each other so as to be able to swing relative to each other (for example, Patent Document 1).
Japanese Patent Laid-Open No. 2003-41932

  The FF horizontal engine is mounted on the front of the vehicle body because the pipe axis direction of the exhaust pipe connected to the FF engine is perpendicular to the crankshaft direction (the left-right direction, ie, the direction substantially perpendicular to the pipe axis). The engine body that swings moves much more greatly in the rotation direction (vertical direction) of the crankshaft than in the crankshaft direction. For this reason, the upstream and downstream exhaust pipes connected to the FF horizontal engine are remarkably swung in the vertical direction with respect to the horizontal direction. In this way, if the conventional pipe joint configured to allow the relative swinging between the two pipes, which are greatly biased in the vertical direction, to be allowed evenly in all directions, up and down, is sufficiently absorbed in the horizontal direction. The portion of the seat body greatly protrudes to the left and right for the small swing of the pipe joint, and the pipe joint becomes unnecessarily large.

  Therefore, the problem to be solved by the present invention is a novel structure capable of effectively allowing the mutual swinging of both pipes which are greatly deviated in the vertical direction with respect to the horizontal direction without increasing the size of the joint structure. It is to provide a pipe joint.

  The pipe joint of the present invention is configured as follows.

[Configuration 1]
In a pipe joint that connects one pipe and the other pipe so that they can swing relative to each other,
A first seat body fixed to the outer peripheral surface of the one pipe and having a partially concave spherical surface that expands and opens on the other pipe side at least above and below the connecting portion between the two pipes;
An annular second seat body that is fixed to the outer peripheral surface of the other tube, has a reduced diameter on the one tube side, and has a partially convex spherical surface provided to face the partially concave spherical surface;
Three or more rigid spheres having the same diameter sandwiched between the partially concave spherical surface and the partially convex spherical surface;
A retainer that holds the rigid sphere above and below the connection between the two tubes;
An annular seal body that seals between the first seat or the one tube and the second seat over the entire circumference;
An urging mechanism for urging the first seat and the second seat so as to approach each other in the tube axis direction.

  The pipe joint of Configuration 1 is configured such that one pipe and the other pipe are elastically biased and connected in a direction in which the pipes are close to each other in the axial direction, and the first seat body and the second seat body are connected by a seal body. Is sealed over the entire circumference to seal the connection between both pipes. The distance between the partially concave spherical surface of the first seat and the partially convex spherical surface of the second seat is always kept constant by three or more rigid spheres having the same diameter held by the retainer. That is, the distance between the partially concave spherical surface and the partially convex spherical surface is kept at a distance corresponding to the diameter of the hard sphere. As a result, the pressure (contact pressure) between the second seat body and the seal body is always kept constant, so that the sealing performance between the two seat bodies by the seal body is always kept stable. Since the frictional force between both seats and the rigid sphere is extremely small compared to the frictional force between both seats and the seal body, the presence of the rigid spheres impairs the relative swingability of both seats. Absent. In addition, three or more rigid spheres are provided above and below the connecting portion between the pipes, that is, some of the three or more rigid spheres are above the connecting portion and the remaining ones. By separately arranging the parts below the connection part, it is possible to effectively allow the mutual swinging of both pipes which are largely deviated in the vertical direction with respect to the horizontal direction without increasing the size of the joint structure. it can. Since this pipe joint is provided with three or more rigid spheres, the relative oscillation between the two pipes can be always allowed in a stable state.

[Configuration 2]
Assuming configuration 1, the retainer is
A first holding part for holding the rigid sphere above the connection part between both pipes;
A second holding part for holding the rigid sphere below the connection part between the pipes;
A pipe joint having a pair of left and right connecting portions that elastically connect both holding portions.

  In the pipe joint of Configuration 2, some of the three or more hard spheres are held by the first holding part, and the remaining some are held by the second holding part. Then, both the holding portions are elastically connected by a pair of left and right connecting portions, thereby effectively allowing the two pipes to swing with respect to the left and right directions which are largely biased in the vertical direction. With this configuration, the pipe joint can be reduced in size and weight.

[Configuration 3]
On the premise of Configuration 2, the pair of left and right connecting portions are provided on the left and right sides so as to sandwich the connecting portion, and one end of the seal body is engaged with one connecting portion and the other connecting portion is A pipe joint in which the left and right end portions of the seal body are engaged, and the pair of left and right connecting portions and the seal body are slidable with each other while maintaining an engaged state.

  In the pipe joint of Configuration 3, the seal body and the retainer can be simply integrated by engaging the seal body so as to span the left and right connecting portions of the retainer. And when connecting both pipes, a sealing body and a retainer can be attached to the connection part of both pipes in the state of integrating simply. Thereby, the mounting | wearing operation | work to the connection part of both pipes of a seal body and a retainer can be facilitated. Since the pair of left and right connecting portions and the seal body can slide with each other while maintaining the engaged state, it is not necessary to release the engagement between the two after the mounting.

[Configuration 4]
Assuming configuration 3, the sealing body is
An annular sealing material holder engaged with the pair of left and right connecting portions, and an annular sealing material held by the sealing material holder,
The sealing material holder is airtightly joined to the first seat or the one pipe over the entire circumference,
The seal member is a pipe joint that is in airtight contact with the second seat over the entire circumference.

  According to the pipe joint of Configuration 4, the seal body for the second seat body in a state where the first seat body or one of the pipes to which the first seat body is fixed and the seal body are completely hermetically sealed over the entire circumference. The second seat body and the seal body can be hermetically sealed over the entire circumference while securing the slidability.

[Configuration 5]
A pipe joint in which a lubricant layer is formed on the surface of the sealing material on the premise of Configuration 4.
According to the pipe joint of structure 5, the slidability with respect to the 2nd seat of a sealing material can be improved, and the absorption performance with respect to a minute vibration can be improved. As a result, even if a minute vibration is generated in one tube, it is possible to prevent the minute vibration from being transmitted to the other tube as much as possible, and to suppress the generation of abnormal sound (stagnation sound).

  According to the pipe joint having the above-described configuration, it is possible to effectively allow the mutual swinging of both pipes greatly deviated in the vertical direction with respect to the left-right direction without increasing the size of the joint structure.

  Hereinafter, the present invention will be described in detail according to embodiments with reference to the drawings.

  FIG. 1 is a front view of a pipe joint according to the present invention. FIG. 2 is a partial cross-sectional view in the vertical direction (AA direction in FIG. 1) along the tube axis of the pipe joint according to the present invention. FIG. 3 is a partial cross-sectional view in the horizontal direction (BB direction in FIG. 1) along the tube axis of the pipe joint according to the present invention. FIG. 4 is a perspective view showing a connected state of a retainer which is one of the components of the pipe joint according to the present invention and a seal body. FIG. 5 is a front view of the upper half of the retainer and the seal body shown in FIG.

  The pipe joint 100 includes an annular first seat 110 provided at an end of a downstream exhaust pipe (one pipe) 201 and an annular provided at an end of an upstream exhaust pipe (other pipe) 202. The second seat 120, a plurality of (four in this example) rigid spheres 150 sandwiched between the two seats 110, 120, and the rigid sphere 150 are connected to each other between the pipes 201, 202. A retainer 130 that is held upward and downward, an annular seal body 140 that seals between the downstream exhaust pipe 201 and the second seat body 120 over the entire circumference, and a direction in which the seat bodies 110 and 120 are brought closer to each other. And an urging mechanism 160 for urging elastically. The exhaust pipes 201 and 202 constitute part of an exhaust system connected to the engine. In this example, the end 201a of the downstream exhaust pipe 201 has an enlarged diameter, and is configured to accommodate the end 202a of the upstream exhaust pipe 202.

  The first seat 110 is welded and fixed to the outer peripheral surface of the end 201a of the downstream side exhaust pipe 201 in an airtight manner over the entire circumference. The first seat 110 has a substantially oval-shaped partial spherical shell 112 formed in a vertically long shape. The partial spherical shell portion 112 has partial concave spherical surfaces 111a and 111b whose diameter is increased toward the upstream side exhaust pipe 202 at the upper and lower portions. A through hole 112 a into which the end 201 a of the downstream exhaust pipe 201 is inserted is formed at the center of the partial spherical shell portion 112. The left and right ends at the center in the vertical direction of the partial spherical shell 112 are slightly constricted in an arc shape. The first seat 110 is formed by extending the left and right ends at the center in the vertical direction of the partial spherical shell 112 so as to bend toward the second seat 120, and then turning back outward from the left and right. A pair of flange portions 114 are formed. Each of the flange portions 114 is formed with a bolt fixing hole 113 (see FIG. 3) at one place. Both left and right end portions of the flange portion 114 are extended so as to be bent toward the second seat body 120 side.

  The second seat body 120 is welded and fixed to the outer peripheral surface of the end portion of the upstream side exhaust pipe 202 in an airtight manner over the entire circumference. The second seat 120 has a spherically convex partially convex spherical surface 121 that protrudes (reduces diameter) toward the downstream side exhaust pipe 201. The second seat body 120 has a flange portion 124 formed to face the flange portion 114 of the first seat body 110. A bolt insertion hole 123 is formed in the flange portion 124 of the second seat body 120 so as to correspond to the bolt fixing hole 113 of the flange portion 114 of the first seat body 110. The outer peripheral portion of the flange portion 124 is extended so as to be bent toward the engine side, and is further extended toward the first seat 110 side so as to be folded back outwardly in a bag shape with a U-shaped cross section. And the front-end | tip part of the flange part 114 of the 1st seat 110 is accommodated in the part folded in this bag shape.

  Two hard spheres 150 are arranged above and below the connection between the pipes 201 and 202, respectively, with the mutual positional relationship in the circumferential direction kept constant. These four hard spheres 150 have the same diameter.

  The retainer 130 includes a first holding member 130A that holds the rigid sphere 150 above the connecting portion between the tubes 201 and 202, and a second holding member that holds the rigid sphere 150 below the connecting portion between the tubes 201 and 202. It has a member 130B and a pair of left and right retainer connection springs 131A and 131B that elastically connect both holding members 130A and 130B in a vertically displaceable manner. Both holding members 130A and 130B are metal members.

  Both holding members 130 </ b> A and 130 </ b> B have a horizontally long plate-like member main body 134, and tubular connecting portions 135 integrally formed at the left and right ends of the member main body 134. The member main body 134 has through holes 133 for holding the rigid sphere 150 at two positions on the left and right sides. Cuts are formed in the peripheral portion of the through-hole 133 at even locations. Then, the peripheral sphere of the through-hole 133 is cut and alternately folded back and forth to fit with the rigid sphere 150, thereby preventing the rigid sphere 150 from falling off the through-hole 133. The connection part 135 penetrates up and down. The retainer connection springs 131A and 131B and the holding member main body 134 are connected to each other by tightening the connection part 135 with the end portions of the retainer connection springs 131A and 131B inserted into the connection part 135.

  The pair of left and right retainer coupling springs 131A and 131B are provided on the left and right sides so as to sandwich the connecting portion between the pipes 201 and 202. And the other left and right ends (left end) of the seal body 140 are engaged with the other retainer connecting spring 131B. The pair of left and right retainer coupling springs 131A and 131B and the seal body 140 can slide with each other while maintaining the engaged state.

  The seal body 140 includes an annular (cylindrical) seal material holder 141 engaged with a pair of left and right retainer coupling springs 131 </ b> A and 131 </ b> B, and an annular seal material 142 held by the seal material holder 141. The seal material holder 141 is mounted on the outer periphery of the end portion 201a of the downstream side exhaust pipe 201, and is hermetically welded and fixed over the entire periphery. Engaging portions 141 a and 141 b are formed at both left and right end portions of the seal material holder 141 so as to project outward in an ear shape. The distal ends of the engaging portions 141a and 141b are curved backward in an arc shape, and the curved portions are slidably engaged with the retainer coupling springs 131A and 131B. The sealing material 142 is in air-tight sliding contact with the partially convex spherical surface 121 of the second seat 120 over the entire circumference. A lubricant layer is formed on the surface of the sealing material 142. As a result, while the downstream exhaust pipe 201 and the seal body 140 are completely hermetically sealed over the entire circumference, the second slidable body 120 is ensured to be slidable with respect to the second seat body 120, and the second The space between the seat body 120 and the seal body 140 is hermetically sealed over the entire circumference.

  The urging mechanism 160 includes a stepped bolt 161, a nut 162, and a coil spring (elastic body) 163. The stepped bolt 161 is inserted into the bolt insertion hole 113 of the flange portion 114 of the first seat 110 from the downstream exhaust pipe 201 side, and the thread portion formed at the tip portion of the flange portion 124 of the second seat body 120. The upstream exhaust pipe 202 and the downstream exhaust pipe 201 are connected to each other by being inserted into the bolt fixing hole 123 and fixed to the nut 162 so as not to be detached. Further, the bolt insertion hole 113 is formed with a margin with respect to the diameter of the stepped bolt 161 and has a structure that allows the upstream exhaust pipe 202 and the downstream exhaust pipe 201 to swing relative to each other. The coil spring 163 is provided so as to surround the stepped bolt 161.

  The pipe joint 100 configured as described above is connected to the downstream side exhaust pipe 201 and the upstream side exhaust pipe 202 by elastically urging them so as to approach each other in the axial direction. By sealing between the seat 110 and the second seat 120 over the entire circumference, the connecting portion between the pipes 201 and 202 is sealed. The distance between the partially concave spherical surfaces 111a and 111b of the first seat 110 and the partially convex spherical surface 121 of the second seat 120 is always constant by the four rigid spheres 150 held by the retainer 130 and having the same diameter. To be kept. That is, the distance between the partially concave spherical surfaces 111 a and 111 b and the partially convex spherical surface 121 is kept at a distance corresponding to the diameter of the rigid sphere 150. As a result, the pressure (contact pressure) between the second seat 120 and the seal body 140 is always kept constant, so that the sealing performance between the both seats 110 and 120 by the seal body 140 is always kept stable. Since the frictional force between the two seats 110 and 120 and the rigid sphere 150 is extremely small compared to the frictional force between the second seat 120 and the seal body 140, the presence of the rigid sphere 150 causes the two seats 110 and 120, The relative rocking property of 120 is not impaired. Further, since the rigid sphere 150 is disposed only above and below the connection portion between the pipes 201 and 202, the mutual swinging of the pipes 201 and 202, which is greatly deviated in the vertical direction with respect to the left-right direction, is coupled. The structure can be effectively tolerated without increasing the size.

  Further, in this pipe joint 100, the seal body 140 and the retainer 130 are simply integrated by engaging the seal body 140 with the left and right retainer coupling springs 131A and 131B of the retainer 130. be able to. When the pipes 201 and 202 are connected to each other, the seal body 140 and the retainer 130 can be attached to the connection part between the pipes 201 and 202 in a simple integrated state. Thereby, the mounting operation | work to the connection part of both the pipes 201 and 202 of the seal body 140 and the retainer 130 can be facilitated. Since the pair of left and right retainer coupling springs 131A and 131B and the seal body 140 can slide with each other while being engaged with each other, it is not necessary to release the engagement between them.

  The rigid sphere 150 used in the pipe joint of the present invention is not particularly limited, but preferably a stainless steel ball, a ceramic ball or the like is used, and a silicon nitride ceramic ball is more preferably used. Silicon nitride ceramic balls are hard and lightweight, and are excellent in durability, and can easily absorb minute vibrations due to smoothness. In addition, since the materials of the ball and the flange are different, the generation of micropits (fine irregularities) can be prevented, and the performance can be maintained for a long time.

  Moreover, as a material of the sealing body used as the ring member described in each of the above embodiments, for example, a heat-resistant sealing material composed of an inorganic filler or a carbonized material, a stainless wire mesh compressed product, or a stainless wire mesh compressed product And a mixture of heat resistant resin and the like. And it is preferable that the lubricant layer is formed in the surface of the sealing body which consists of one of these heat resistant materials. Moreover, you may form the layer which has heat resistance and lubricity in the partial concave spherical surfaces 111a and 111b and the partial convex spherical surface 121. FIG.

  Further, in the pipe joint of the present invention, the rigid sphere 150 may be rotatably held by the retainer 130. In the above example, the sealing material holder 141 is joined to the downstream exhaust pipe 201, but may be joined to the first seat body 110.

  In the above example, the number of the rigid spheres 150 is four, and the case where the two rigid spheres 150 are arranged in the upper and lower portions of the connection portions of the two tubes 201 and 202 has been described. The number may be three or five or more, and even in the case of an even number, it is not always necessary to arrange them evenly. For example, when the number of the rigid spheres 150 is three, two of them are arranged above or below the connecting portion, and one is arranged above or below the connecting portion, so that the relative vibrations of the tubes 201 and 202 can be compared. The movement can always be allowed in a stable state.

  The retainer 130 shown in the above example includes a first holding member 130A, a second holding member 130B, and retainer connecting springs 131A and 131B, which are connected to each other and integrated. You may implement | achieve as a metal integrally molded product. By using the retainer 130 as an integrally molded product, the number of parts of the pipe joint 100 can be reduced.

Front view of the pipe joint according to the present invention The fragmentary sectional view of the perpendicular direction (AA direction of FIG. 1) along the pipe axis of the pipe joint which concerns on this invention The fragmentary sectional view of the horizontal direction (BB direction of FIG. 1) along the pipe axis of the pipe joint which concerns on this invention The perspective view which shows the connection state of the retainer which is one of the components of the pipe joint which concerns on this invention, and a seal body Front view of retainer and upper half of seal body shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Pipe joint 110 1st seat body 111a, 111b Partial concave spherical surface 112 Partial spherical shell part 114 Flange part 120 2nd seat body 121 Partial convex spherical surface 124 Flange part 130 Retainer 130A 1st holding member (holding part)
130B 2nd holding member (holding part)
131A, 131B Retainer connection spring (connection part)
140 Sealing body 141 Sealing material holder 142 Sealing material 150 Rigid sphere 160 Energizing mechanism 201 Downstream exhaust pipe (one pipe)
202 Upstream exhaust pipe (the other pipe)

Claims (3)

In a pipe joint that connects one pipe and the other pipe so that they can swing relative to each other,
A first seat body fixed to the outer peripheral surface of the one pipe and having a partially concave spherical surface that expands and opens on the other pipe side at least above and below the connecting portion between the two pipes;
An annular second seat body that is fixed to the outer peripheral surface of the other tube, has a reduced diameter on the one tube side, and has a partially convex spherical surface provided to face the partially concave spherical surface;
Three or more rigid spheres having the same diameter sandwiched between the partially concave spherical surface and the partially convex spherical surface;
A retainer that holds the rigid sphere above and below the connection between the two tubes;
An annular seal body that seals between the first seat or the one tube and the second seat over the entire circumference;
An urging mechanism that urges the first seat and the second seat to approach each other in the tube axis direction;
The retainer is
A first holding part for holding the rigid sphere above the connection part between both pipes;
A second holding part for holding the rigid sphere below the connection part between the pipes;
A pipe joint comprising: a pair of left and right connecting portions that elastically connect both holding portions.   The pair of left and right connecting portions are provided so as to sandwich the connecting portion, and one of the left and right ends of the seal body is engaged with one of the connecting portions, and the other left and right ends of the seal body are engaged with the other connecting portion. The pipe joint according to claim 1, wherein the pair of left and right connecting portions and the seal body are slidable with each other while being engaged with each other. The sealing body is
An annular sealing material holder engaged with the pair of left and right connecting portions, and an annular sealing material held by the sealing material holder,
The sealing material holder is airtightly joined to the first seat or the one pipe over the entire circumference,
The pipe joint according to claim 2, wherein the sealing material is in airtight contact with the second seat over the entire circumference.

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