JP2006218915A - Exhaust pipe resonance suppression device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust pipe resonance suppression device capable of suppressing generation of stuffy sound in a cabin and resonance of a steering based on vibration of an exhaust system and realizing efficiency of work for suppression. <P>SOLUTION: The exhaust pipe resonance suppression device is provided with a pair of upper and lower brackets 2, 3 for clamping both front tubes 12a, 12b by both end clamping parts 21, 31 from a vertical direction; and a C-shape clamp 4 having bolt insertion holes 42a, 43a at both end fastening parts 42, 43 of a partially notched annular part 41 mountable in the state for surrounding an outer periphery of one front tube 12a. Bolt insertion holes 23a, 33a for fastening both brackets 2, 3 each other are formed on an intermediate part in a longitudinal direction in both brackets 2, 3, an extension part 34 having a co-fastening hole 34a for co-fastening both end fastening parts 42, 43 is formed on one end of one bracket 2 and the C-shape clamp 4 is previously fixed to one bracket 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an exhaust pipe resonance suppression device for restraining resonance by restraining two exhaust pipes connected to an engine to each other.

  Usually, the two exhaust pipes arranged opposite to the engine are each provided with a flexible tube in the middle, and are gathered into one exhaust pipe on the downstream side of both flexible tubes (for example, Patent Document 1). reference.).

Japanese Patent Application Laid-Open No. 6-108841 (Specification (page 3), FIG. 2)

  However, as described above, the vibration of the exhaust pipe is absorbed on the downstream side of the flexible tube by the intervention of the flexible tube, but the heat of the exhaust gas is released on the upstream side of the flexible tube via the bracket. Since it is not fixed to the vehicle body in order to prevent this, there are problems as described below.

  That is, in particular, in the V-type engine in which the exhaust manifolds are opposed to each other in the vehicle longitudinal direction, both the front and rear exhaust manifolds having different rigidity and the front and rear manifold converters having different weights and lengths are used. As shown by the solid line in (experimental data indicating vibration acceleration amplitude level (dB) with respect to engine rotation speed (rpm)), a large resonance phenomenon occurs over two locations (A part and B part) upstream of the flexible tube, This resonance causes the engine to vibrate through the exhaust manifold, and this vibration causes vehicle body vibration through the engine mount, which causes a loud noise in the passenger compartment (see section C).

In addition, the resonance of the manifold converter is caused to vibrate the engine through the exhaust manifold, and this vibration causes the steering (handle) to resonate from the transmission via the drive shaft.
The above-described problems can also occur in a V-type engine in which exhaust manifolds are arranged to face each other in the vehicle width direction.

  The problem to be solved by the present invention is that an exhaust pipe capable of suppressing the generation of a humming noise in the passenger compartment and the resonance of the steering wheel due to vibrations of the exhaust system and improving the efficiency of the work for the suppression. The object is to provide a resonance suppression device.

  In order to solve the above-mentioned problem, an exhaust pipe resonance suppression apparatus according to claim 1 is an exhaust pipe resonance suppression apparatus for restraining resonance by restraining two exhaust pipes connected to an engine to each other. For fastening to a pair of upper and lower brackets that sandwich both exhaust pipes at both ends from the top and bottom, and a fastening part at both ends of an annular part that can be attached in a state of surrounding either one of the two exhaust pipes A C-type clamp having a hole, and a fastening hole for fastening the brackets to each other is formed at a longitudinal intermediate portion of the brackets. An extension having a fastening hole for fastening both ends of the C-type clamp together is formed at one end, and the C-type clamp is attached to one of the brackets. And a means, characterized in that it is because fixed.

  The exhaust pipe resonance suppression device according to claim 2 is the exhaust pipe resonance suppression device according to claim 1, wherein the exhaust pipe resonance suppression device is interposed between the longitudinal intermediate portions where the fastening holes are formed in the brackets. A positioning collar that regulates and positions a distance between each other, and a bolt and a nut that pass through the positioning collar and the fastening holes of the brackets and fasten the brackets to each other. The means is fixed to either one of the brackets in advance, and the positioning collar is fixed to either one of the brackets in advance.

  The exhaust pipe resonance suppression apparatus according to claim 3 is the exhaust pipe resonance suppression apparatus according to claim 2, wherein the positioning collar and the bolt are fixed in advance to the same bracket. Suppressor.

  The exhaust pipe resonance suppression device according to claim 4 is the exhaust pipe resonance suppression device according to any one of claims 1 to 3, wherein the two exhaust pipes of the two systems are arranged opposite to each other in the longitudinal direction of the vehicle in the engine. It was made the means characterized by being connected to the both exhaust manifolds.

The exhaust pipe resonance suppression device according to claim 1 restrains the two exhaust pipes connected to the engine to each other as described above, and thus restrains the two exhaust pipes from each other. As a result, the individual rigidity is improved and vibrations are suppressed. This suppresses the vibration acceleration amplitude level of the large resonance phenomenon that has occurred so far, and the resonance in the low rotation region moves to the high rotation region. Abnormal vibration of the engine is greatly reduced.
Therefore, it is possible to suppress the generation of a booming noise in the vehicle interior and the resonance of the steering wheel due to the vibration of the exhaust system.

  In addition, since the exhaust pipe resonance suppression device according to the first aspect is configured as described above, the two exhaust pipes are constrained to each other, but the stage before the assembly of the exhaust system to the vehicle body (delivery stage, transport In step 1), with the partially cut annular part of the C-type clamp wrapped around and attached to one exhaust pipe, the two end fastening parts are temporarily fixed by spot welding for drop-off prevention. On the other hand, one bracket can be temporarily set in advance.

  When the assembly of the two exhaust pipes to the vehicle body is completed, the other bracket is placed opposite to the bracket that has already been temporarily fixed with the two exhaust pipes sandwiched between them. The nuts are screwed and fastened to the bolts inserted through the fastening holes formed in the respective parts, thereby restraining the two exhaust pipes from each other while being sandwiched between both ends of the brackets, and the C-type clamp. The C-type clamp is fixed by screwing a nut into a bolt inserted into a fastening hole formed in the both-end fastening part and a joint fastening hole in the extension part of the other bracket, thereby fastening the two systems. The exhaust pipes can be constrained to each other.

  As described above, because of the presence of the C-type clamp fixed in advance to one bracket, the assembly work to the vehicle body can be performed with one bracket temporarily fixed to one exhaust pipe. As a result, the assembly of the brackets for restraining the exhaust pipes by fastening the pair of upper and lower brackets, which are the body, to each other with bolts and nuts is simplified, and the work efficiency can be improved.

In the exhaust pipe resonance suppression device according to claim 2, as described above, the gap between the brackets is regulated by being interposed between the intermediate portions in the longitudinal direction where the fastening holes are formed in the brackets. By providing a positioning collar for positioning, the shape of both brackets itself can be simplified to a shape close to a flat plate, so that the manufacturing cost can be reduced.
In addition, by adopting a configuration in which the positioning collar and the bolt are fixed in advance to either one of the brackets, it is possible to prevent the loss of parts and the occurrence of delivery leakage, and further the assembly work. It becomes possible to simplify.

  In the exhaust pipe resonance suppression device according to claim 3, as described above, the positioning collar and the bolt are fixed to the same bracket in advance, so that the bolt is inserted into the positioning collar in the assembling work. Since the process to perform becomes unnecessary, the assembling work can be further simplified.

  In the exhaust pipe resonance suppression device according to claim 4, as described above, the two exhaust pipes connected to the two exhaust manifolds opposed to each other in the longitudinal direction of the vehicle in the engine are restrained. As described above, in an engine of a type in which both exhaust manifolds are opposed to each other in the longitudinal direction of the vehicle, the length and weight of the exhaust system are greatly different, so that resonance phenomenon that occurs at two locations upstream of the flexible tube is particularly large. However, by constraining the two exhaust pipes to each other, the individual rigidity is improved and vibration is suppressed, so that the vibration acceleration amplitude level of the large resonance phenomenon that has occurred so far can be suppressed and low rotation speed can be reduced. The resonance of the region moves to the high rotation region, and the abnormal vibration of the engine is greatly reduced. It is possible to suppress the occurrence and the resonance of the handle forest sounds.

Embodiments of the present invention will be described below with reference to the drawings.
The exhaust pipe resonance suppression device of this embodiment corresponds to the invention described in claims 1 to 3. In this embodiment, a case will be described in which the exhaust manifold is applied to an exhaust system of a V-type engine that is opposed to the vehicle in the longitudinal direction.

First, the exhaust pipe resonance suppression device of this embodiment will be described with reference to the drawings.
FIG. 1 is an overall view showing an exhaust pipe resonance suppression device of this embodiment, in which 1 is a V-type engine, 10a is a front side exhaust manifold, 10b is a rear side exhaust manifold, 11a is a front side manifold converter, 11b is a rear manifold converter, 12a is a front bank side front tube (exhaust pipe), 12b is a rear bank side front tube (exhaust pipe), 13a is a front bank side flexible tube, 13b is a rear bank side flexible tube, and 14 is an underfloor converter, Reference numeral 15 is a rear tube, 16 is a pre-muffler, 17a and 17b are branch tubes, 18a and 18b are rear mufflers, 19 is an exhaust system suspension device, and A is an exhaust pipe resonance suppression device.

The exhaust pipe resonance suppression device A serves to suppress resonance of the exhaust pipe by restraining the front bank side front tube 12a and the rear bank side front tube 12b on the upstream side of the flexible tubes 13a and 13b. FIG. 2 (front view of the whole bracket), FIG. 3 (front view of the upper bracket), FIG. 4 (plan view of the upper bracket), FIG. 5 (front view of the lower bracket), and FIG. As shown in the figure, an upper bracket 2, a lower bracket 3, a C-type clamp 4, a positioning collar 5, bolts and nuts 6a and 6b, and bolts and nuts 7a and 7b are provided.
The exhaust pipe resonance suppression device A restrains both front tubes 12a and 12b upstream of both flexible tubes 13a and 13b, but is provided for the purpose of restraining both flexible tubes 13a and 13b themselves. It is not something that can be done.

  More specifically, the upper bracket 2 and the lower bracket 3 are a pair of upper and lower brackets that restrain each other by sandwiching the front bank side front tube 12a and the rear bank side front tube 12b from both ends in the vertical direction. The metal plates are integrally formed by press forming.

  Both brackets 2 and 3 are formed with sandwiching portions 21, 22, 31 and 32 for sandwiching both tubes 12 a and 12 b at both ends thereof, and both sandwiching portions 21, 22, 31, Fastening portions 23 and 33 are formed so as to protrude slightly in the opposite direction from 32.

  One clamping part 21 and 31 is formed in the circular arc shape along the outer surface of the front bank side front tube 12a, and exhaust system point support is provided in two longitudinal directions (arc direction) on the opposing inner peripheral surface side. Embosses 21a, 21a, 31a, 31a are formed, and at the four points between the embosses 21a, 21a, 31a, 31a, a front bank side is provided via a partially cut-out annular portion 41 to be described later in the C-type clamp 4. The front tube 12a is clamped.

  The other sandwiching portions 22 and 32 are formed in parallel with each other, and at the center thereof are embossed for supporting the exhaust system point in a state of being long in the longitudinal direction and parallel to each other protruding in the opposite direction. 22a and 32a are formed, and the rear bank side front tube 12b is sandwiched at two points between the embosses 22a and 32a.

  An extension 34 extending in the horizontal direction is integrally formed at the end of the arc-shaped holding portion 32 in the lower bracket 3, and along the lower surface side from the extension 34 to the holding portion 32. The reinforcing plate 35 is fixed by spot welding or the like. Reinforcing ribs 2a and 3a that are bent outward (vertical direction) are formed on both side edges in the longitudinal direction of both brackets 2 and 3, respectively.

  In addition, bolt insertion holes (fastening holes) 23a and 33a for fastening the brackets 2 and 3 with bolts and nuts 6a and 6b are formed at the center of the fastening parts 23 and 33, Bolt insertion holes (co-tightening holes) 36 for fastening both end fastening portions 42 and 43 of the C-shaped clamp 4 described later are formed at the extension 34 of the lower bracket 3 and the ends of the reinforcing plate 35. Has been.

  The C-shaped clamp 4 is composed of a partially-cut annular portion 41 that can be attached in a state of surrounding the outer periphery of the front bank side front tube 12a, and both-end fastening portions 42, 43 that face both ends in parallel. Bolt insertion holes (fastening holes) 42 a and 43 a are formed at the tip ends of the both-end fastening portions 42 and 43.

  Reinforcing ribs 4 a that are bent outward (upward) are formed on both side edges from one (upper) fastening portion 42 to a part of the partially cut-out annular portion 41. The C-type clamp 4 is fixed in advance by spot-welding b and b to the embosses 21a and 21a of the upper bracket 2 with the partially-cut annular portion 41.

  The positioning collar 5 regulates the distance between the brackets 2 and 3 by being interposed between the fastening portions 23 and 33 in which the bolt insertion holes 23a and 33a are formed. The positioning collar 5 is fixed by welding in advance to the opening edge of the bolt insertion hole 23a of the fastening portion 23 of the upper bracket 2 in the positioning collar 5.

  The bolts and nuts 6a and 6b pass through the bolt insertion holes 23a and 33a formed in the fastening portions 23 and 33 in the positioning collar 5 and the brackets 2 and 3 and fasten the brackets 2 and 3 to each other. Is to do. The head of the bolt 6 a is fixed to the fastening portion 23 by welding in a state where the bolt 6 a is inserted through the bolt insertion hole 23 a on the upper bracket 2 side and the positioning collar 5 in advance.

  The bolts and nuts 7 a and 7 b are for fastening both the end fastening portions 42 and 43 in the C-type clamp 4 and the extension portion 34 of the lower bracket 3 together. The bolt 7a is fixed to the fastening portion 42 by welding in a state where the bolt 7a is previously formed in the upper fastening portion 42 and is inserted through the bolt insertion hole 42a.

Next, the operation and effect of this embodiment will be described.
In this embodiment, as shown in FIG. 1, two exhaust systems connected to the V-type engine 1 are constrained to each other by the exhaust pipe resonance suppression device A, but before the exhaust system is assembled to the vehicle body ( In the delivery stage and the transport stage), as shown in FIGS. 3 and 4, in the state where the partially cut annular part 41 of the C-shaped clamp 4 is wound around the front bank side front tube 12 a and attached, The upper bracket 2 can be temporarily set in advance with respect to the front bank side front tube 12a of one of the two systems by temporarily fixing 43 by the drop-welding prevention spot weld c.

  Then, when the assembly of the front bank side front tube 12a and the rear bank side front tube 12b to the vehicle body is completed, the upper bracket 2 that has already been temporarily fixed is placed under the other with the both front tubes 12a and 12b being sandwiched therebetween. The side brackets 3 are opposed to each other, and nuts 6b are screwed into bolts 6a fixed in advance to the fastening portions 23 of the upper bracket 2 to fasten both brackets 2 and 3, whereby both end clamping portions of both brackets 2 and 3 are clamped. The front tubes 12a and 12b are mutually restrained while being sandwiched between 21-31 and 22-32, and the fastening holes 42a and 43a formed in the both-end fastening portions 42 and 43 of the C-type clamp 4 and the lower side The nut 7b is screwed into the bolt 7a inserted into the joint fastening hole 34a of the extension 34 in the bracket 3 and tightened. The C-shaped clamp 4 is fixed by, thereby, two systems of exhaust system between the two front tubes 12a, may be mutually the constrained state in the portion of 12b.

  As described above, by restraining each other by the exhaust pipe resonance suppression device A, the rigidity of each of the front tubes 12a and 12b is improved and vibrations are suppressed, thereby preventing the large resonance phenomenon that has occurred so far. The vibration acceleration amplitude level is suppressed, and the resonance in the low rotation region moves to the high rotation region, so that abnormal vibration of the engine can be greatly reduced.

FIG. 7 is experimental data showing the vibration acceleration amplitude level (dB) with respect to the engine rotational speed (rpm). As shown by the dotted line of this experimental data, the vertical vibration characteristics of the front position of the front bank side flexible tube 13a are shown. The resonance of A has moved to A1, and the resonance of B, which is the vertical vibration characteristic of the front position of the rear bank side flexible tube 13b, has moved to B1, and as a result, the front seat noise level C has decreased to max 5 dB. .
Therefore, it is possible to suppress the generation of a booming noise in the vehicle interior and the resonance of the steering wheel due to the vibration of the exhaust system.

  Further, due to the presence of the C-shaped clamp 4 fixed in advance to the one upper bracket 2, the assembling work to the vehicle body is performed with the one upper bracket 2 temporarily fixed to the one front bank side front tube 12a in advance. Therefore, the assembly work of the brackets 2 and 3 for restraining the front tubes 12a and 12b by fastening the pair of upper and lower brackets 2 and 3 which are separate members with the bolt 6a and the nut 6b is simplified. As a result, it is possible to improve the efficiency of work.

In addition, a positioning collar 5 is provided which is positioned between the two fastening portions 23 and 33 formed with the bolt insertion holes 23a and 33a in the brackets 2 and 3 so as to regulate the distance between them. With this configuration, the shape of both brackets 2 and 3 can be simplified to a shape close to a flat plate, so that the manufacturing cost can be reduced.
Further, by adopting a configuration in which the positioning collar 5 and the bolt 6a are fixed to the upper bracket 2 in advance, it is possible to prevent parts from being lost or to be delivered and to be assembled. Further simplification can be achieved.

  Further, since the positioning collar 5 and the bolt 6a are fixed to the same upper bracket 2 in advance, the step of inserting the bolt 6a into the positioning collar 5 is not required in the assembling work. As a result, the assembly work can be further simplified.

  Further, the exhaust pipes 21a, 22a, 31a, 32a for supporting the exhaust system abutting against the front tubes 12a, 12b are formed on the both-end holding portions 21, 22, 31, 32 of the brackets 2, 3, so that the exhaust pipe It becomes possible to suppress the release of the heat of the exhaust gas through the resonance suppression device A.

  Further, by forming one of the sandwiching portions 22 and 32 in parallel with each other and forming the embosses 22a and 32a of the sandwiching portions 22 and 32 in a state that is long in the longitudinal direction and in parallel with each other, Even if the interval between the front tubes 12a and 12a varies due to the assembled state, the front tubes 12a and 12a can be restrained to each other without difficulty.

Although the present embodiment has been described above, the present invention is not limited to the above-described embodiment, and design changes and the like within a scope not departing from the gist of the present invention are included in the present invention.
For example, in the embodiment, a case has been described in which the present invention is applied to the exhaust system of the V-type engine 1 in which the exhaust manifold is opposed to the vehicle in the front-rear direction, but the exhaust manifold is arranged to face the vehicle width direction of the vehicle. It can also be applied to type engines.

In the embodiment, the positioning collar 5 is interposed between the brackets 2 and 3, but this can be omitted.
In the embodiment, the bolt 6a is fixed to the upper bracket 2 and the bolt 7a is fixed to the C-type clamp 4 in advance.

1 is an overall view showing an engine exhaust system to which an exhaust pipe resonance suppression device of an embodiment is applied. 1 is an overall front view showing an exhaust pipe resonance suppression device of an embodiment. It is a front view which shows the upper side bracket in the exhaust pipe resonance suppression apparatus of an Example. It is a top view which shows the upper side bracket in the exhaust pipe resonance suppression apparatus of an Example. It is a front view which shows the lower bracket in the exhaust pipe resonance suppression apparatus of an Example. It is a top view which shows the lower bracket in the exhaust pipe resonance suppression apparatus of an Example. It is experimental data which shows the vibration acceleration amplitude level with respect to the engine rotational speed in the vehicle to which the exhaust pipe resonance suppression apparatus of the Example was applied.

Explanation of symbols

A Exhaust pipe resonance suppression device b Spot welding 1 V-type engine 2 Upper bracket 2a Reinforcing rib 21 Nipping part 21a Embossing 22 Holding part 22a Embossing 23 Fastening part 23a Bolt insertion hole (fastening hole)
3 Lower bracket 3a Reinforcement rib 31 Holding part 31a Emboss 32 Holding part 32a Emboss 33 Fastening part 33a Bolt insertion hole (fastening hole)
34 Extension 35 Reinforcement plate 36 Bolt insertion hole (joint tightening hole)
4 C-shaped clamp 41 Partially cut-out annular portion 42 Fastening portion 42a Bolt insertion hole 43 Fastening portion 43a Bolt insertion hole 5 Positioning collar 6a Bolt 6b Nut 7a Bolt 7b Nut 10a Front exhaust manifold 10b Rear exhaust manifold 11a Front manifold 11b Rear side manifold 12a Front bank side front tube (exhaust pipe)
12b Rear bank side front tube (exhaust pipe)
13a Front bank side flexible tube 13b Rear bank side flexible tube 14 Underfloor converter 15 Rear tube 16 Pre-muffler 17a Branch tube 17b Branch tube 18a Rear muffler 18b Rear muffler 19 Exhaust system suspension

Claims (4)

An exhaust pipe resonance suppression device for restraining resonance by restraining two exhaust pipes connected to an engine to each other,
A pair of upper and lower brackets sandwiching the exhaust pipes at both ends from the vertical direction;
A C-shaped clamp having fastening holes at both end fastening parts of the partially cutout annular part that can be attached in a state of surrounding the outer periphery of either one of the exhaust pipes,
A fastening hole for fastening the brackets to each other is formed in the middle portion in the longitudinal direction of the brackets.
An extension portion having a fastening hole for fastening both ends of the C-type clamp together is formed at one end of one of the brackets.
The exhaust pipe resonance suppression device according to claim 1, wherein the C-type clamp is fixed in advance to one of the brackets. 2. The exhaust pipe resonance suppression device according to claim 1, wherein the positioning is performed by regulating a distance between the brackets by interposing between the intermediate portions in the longitudinal direction in which the fastening holes are formed in both brackets. Color,
A bolt and a nut that pass through the positioning collar and the fastening holes of the brackets and fasten the brackets;
The bolt is fixed in advance to either one of the brackets;
The exhaust pipe resonance suppression device, wherein the positioning collar is fixed in advance to one of the brackets.   The exhaust pipe resonance suppression apparatus according to claim 2, wherein the positioning collar and the bolt are fixed in advance to the same bracket.   The exhaust pipe resonance suppression device according to any one of claims 1 to 3, wherein the two exhaust pipes of the two systems are connected to both exhaust manifolds disposed opposite to each other in the longitudinal direction of the vehicle in the engine. An exhaust pipe resonance suppression device.

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