JP4150240B2 - Anti-resonance structure of engine exhaust silencer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for suppressing vibration and noise caused by exhaust in an internal combustion engine (engine), and more particularly, to a resonance prevention structure for an engine exhaust silencer.
[0002]
[Prior art]
Conventionally, in order to improve the support rigidity against vibration caused by engine exhaust and to suppress noise, the exhaust pipe connected to the exhaust manifold, exhaust silencer, etc. is thickened, or a throttle part is provided in the middle of the exhaust pipe. The technique of installing is well-known (for example, refer patent document 1). Therefore, the prior art according to directly on the resonant structure for preventing exhaust muffler of an engine of the present invention will be described with reference to FIGS. 2 and 8 and 9. 2 and 8 are perspective views showing a vibration isolating structure of a conventional engine exhaust silencer, and FIG. 9 is a partial front sectional view of the same. The cylinder head 2 and the exhaust manifold 3 of the engine 1 are connected via the packing 8 so that the exhaust gas does not leak by a flange bolt 30, a stud bolt 31, a ceps 32, or the like. An exhaust passage is formed in the cylinder head 2 and the exhaust manifold 3, and these exhaust passages are connected in communication. Exhaust gas is discharged from the engine 1 through an exhaust passage in the cylinder head 2. An exhaust manifold 3 is connected to the downstream side in the exhaust gas discharge direction, and an exhaust outlet portion 3b that is an exhaust outlet of the exhaust manifold 3 and an exhaust silencer 4 that is located downstream of the exhaust manifold 3 are connected to each other. The flange 17 is welded to the inlet pipe 14 protruding from the exhaust inlet portion 4a, and the exhaust inlet portion 4a is connected to the exhaust pipe 24 and the ceps 29 via the gasket 12. The exhaust silencer 4 is provided with an inlet pipe 14 into which exhaust gas discharged from the exhaust outlet portion 3 b of the exhaust manifold 3 flows, and one end of the inlet pipe 14 is inside the exhaust inlet portion 4 a of the exhaust silencer 4. The exhaust inlet portion 4a covers the protruding portion, and the exhaust inlet portion 4a is a reinforcing plate 6 that is a mounting member welded to the outer cylinder 18 of the exhaust silencer 4. The support rigidity is enhanced. In the present specification, the side where the exhaust outlet portion 3b of the exhaust manifold 3 and the exhaust inlet portion 4a of the exhaust silencer 4 are connected to each other at the connecting portion between the exhaust manifold 3 and the exhaust silencer 4 is referred to as “ The “exhaust passage side” and the exhaust silencer 4 opposite to the longitudinal direction on the exhaust passage side will be referred to as “support portion side”. The support side of the exhaust silencer 4 is a vibration-proof support member welded to the exhaust silencer 4 by a stay 13 fastened to the cylinder head 2 and the exhaust silencer 4 by bolts 19 and 25 or the like. It is supported and supported by an anti-vibration stay 7.
[0003]
[Patent Document 1]
JP 2000-328936 A [0004]
[Problems to be solved by the invention]
However, in the conventional exhaust silencer support structure described with reference to FIGS . 2, 8, and 9, the stays, the reinforcing plates, Since flanges and the like provided at the exhaust inlet of the exhaust silencer are used as separate parts and are connected by welding, the number of parts is increased, and accordingly, the number of welding points is inevitably increased. Therefore, productivity is not good, and there is a possibility that the burden on the welded part due to vibration fatigue increases. Further, since the reinforcing plate and the anti-rest stay are press products, the degree of freedom in shape is low, and it has been difficult to achieve sufficient rigidity.
[0005]
[Means for Solving the Problems]
The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.
[0006]
In claim 1, the exhaust silencer (4) is connected to the exhaust outlet (3b) of the exhaust manifold (3) at the connection between the exhaust manifold (3) of the engine (1) and the exhaust silencer (4). The exhaust inlet portion (4a) of the exhaust manifold (3) and the exhaust inlet portion (4a) of the exhaust silencer (4) are connected in communication. Is the “exhaust passage side” and the opposite side in the longitudinal direction of the exhaust silencer (4) with respect to the “exhaust passage side” is the “support side”, the parallel to the exhaust silencer (4) An integrally formed extension part (3d) is formed on the “support part side” of the exhaust manifold (3) to be disposed, and the extension part (3d) is formed outside the exhaust silencer (4). It is directly connected to the cylinder (18) .
[0007]
In claim 2, the exhaust silencer (4) is connected to the exhaust outlet (3b) of the exhaust manifold (3) at the connection between the exhaust manifold (3) of the engine (1) and the exhaust silencer (4). The exhaust inlet portion (4a) of the exhaust manifold (3) and the exhaust inlet portion (4a) of the exhaust silencer (4) are connected in communication. Is the “exhaust passage side” and the exhaust silencer (4) in the longitudinal direction opposite to the “exhaust passage side” is the “support portion side”, the exhaust manifold (3 ) Is integrally formed by extending a part of the exhaust silencer (4), and the exhaust pipe (14) is inserted into the reinforcement cover part (3e) to cover the reinforcement cover part (3e). The reinforcing cover part (3e) and the outer cylinder (18) constituting the exhaust silencer (4) Which are connected by sealing engagement with the gasket (23).
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the invention will be described.
[0009]
FIG. 1 is a front view showing a schematic configuration of an engine, and FIG. 2 is a side view of the prior art of FIG .
[0010]
FIG. 3 is a partial front sectional view showing a first embodiment of the vibration damping structure of the exhaust silencer of the engine, FIG. 4 is a view showing the second embodiment, and FIG. 5 is a view showing a reference example .
[0011]
FIG. 6 is a perspective view of a steady stay according to a reference example , and FIG. 7 is a perspective view of a reinforcing plate according to the reference example .
[0012]
8 is a perspective view showing a vibration isolating structure of a conventional engine exhaust silencer, FIG. 9 is a partially sectional front view, FIG. 10 is a perspective view of a conventional anti-rest stay, and FIG. 11 is a perspective view of a conventional reinforcing plate. FIG.
[0013]
An outline of an engine having an anti-vibration structure for an engine exhaust silencer according to the present invention will be described with reference to FIG. In the embodiment of the present invention, a three-cylinder engine is illustrated, but the number of cylinders is not limited to a multi-cylinder engine or a single-cylinder engine. As a main configuration of the engine 1, a cylinder head 2 is attached to the upper end portion of the cylinder block 15, and an oil pan 5 is attached to the lower end portion. When the engine 1 is a multi-cylinder engine, a plurality of the cylinder heads 2 are provided, and the exhaust manifold 3 is formed as a manifold so as to branch from one main pipe so as to correspond to the multi-cylinder engine. The front end side of each manifold is opposed to the cylinder head 2 side. As shown in FIG. 8, the openings 3c, 3c,... At the leading ends of the manifolds are connected by bolts or the like via packings 8 so that the cylinder head 2 and the exhaust manifold 3 communicate with each other. That is, the exhaust gas from the engine 1 is exhausted into the exhaust passage of the cylinder head 2, and the exhaust gas exhausted from the cylinder head 2 is from each opening 3 c of the exhaust inlet portion which is a manifold of the exhaust manifold 3. The exhaust manifold 3 is discharged into the exhaust passage. The exhaust gas joins on the downstream side of the exhaust passage, and is then discharged to the exhaust outlet portion 3b that is the main pipe.
[0014]
The exhaust gas discharged from the exhaust outlet portion 3b of the exhaust manifold 3 as described above enters from the exhaust inlet portion 4a of the exhaust silencer 4, passes through the inlet pipe 14, and passes through the exhaust silencer 4 in a predetermined exhaust passage. Through the exhaust pipe 16.
[0015]
Hereinafter, the resonance prevention structure of an exhaust silencer for an engine according to the present invention will be described in each embodiment while comparing with the prior art. In addition, the Example shown this time is an illustration in all the points, Comprising: It is not restrictive. First, a first embodiment of the anti-resonance structure for an engine exhaust silencer according to the present invention will be described with reference to FIGS. 3, 8 and 9. Conventionally, as shown in FIGS. 2, 8, and 9, the anti-vibration stay 7 that is a vibration-proof support member used on the support side of the connection portion between the exhaust manifold 3 and the exhaust silencer 4 is a press product. It is made of sheet metal, and the anti-vibration stay 7 is welded to the outer cylinder 18 of the exhaust silencer 4, and the anti-vibration stay 7 is interposed on the support side of the connecting portion between the exhaust manifold 3 and the exhaust silencer 4, The stay 13 fastened to the bolt 2 by the bolt 25 is fastened to the exhaust silencer 4 by the bolt 19. However, in such a structure, the number of parts is increased and the anti-rest 7 is a press product, so the degree of freedom with respect to the shape of the anti-vibration stay 7 is low and the shape is limited.
[0016]
Therefore, in this embodiment, as shown in FIG. 3, the extension stay 3d is formed by extending a part of the exhaust manifold 3 without using the anti-rest stay 7, and the extension 3d is used as a stay. . In the exhaust manifold 3, an exhaust outlet portion 3b is formed on one side and connected to the exhaust silencer 4, and an extended portion 3d is formed on the other side to support the exhaust silencer 4. In other words, instead of the conventionally used anti-rest 7, the exhaust manifold 3 is integrally formed with the extended portion 3 d as a stay, and the extended portion 3 d is extended from the inside to the outside of the outer cylinder 18 of the exhaust silencer 4. It has a structure that is fastened via a nut 21 with a protruding welding bolt 20.
[0017]
By adopting such a structure, it is not necessary to use the conventional anti-rest 7 and cost can be reduced. Further, by integrally forming the extended portion 3d in the exhaust manifold 3, the degree of freedom of the shape of the extended portion 3d as a stay is increased with respect to the anti-vibration stay 7 which is a press product, and the extension The installation portion 3d can have a shape corresponding to the exhaust silencer 4, and high rigidity can be easily achieved.
[0018]
Next, a second embodiment will be described with reference to FIGS. 4, 8, 9 and 10. In the prior art, in the connection portion between the exhaust manifold 3 and the exhaust silencer 4, the portion where the inlet pipe 14 inserted through the exhaust silencer 4 protrudes, that is, the exhaust passage side, supports as shown in FIG. The reinforcing plate 6 for reinforcing the above is welded to the exhaust silencer 4 main body, the flange 17 is welded to the inlet pipe 14, and the reinforcing plate 6 and the flange 17 are connected by sealing. However, in such a structure, the number of parts is increased, the cost is increased, and the number of parts to be welded is increased, so that the support rigidity and productivity cannot be said to be good. Furthermore, since the reinforcing plate 6 is a press product, the degree of freedom in shape is low, and it is difficult to suppress resonance of the exhaust silencer 4 due to vibration from the main body of the engine 1.
[0019]
Therefore, in this embodiment, as shown in FIG. 4, the reinforcing cover portion 3e is integrally formed by extending a part of the exhaust manifold 3 without using the conventional reinforcing plate 6, and the reinforcing cover 3e is integrally formed. By covering the cover portion 3e with the inlet pipe 14 protruding from the exhaust silencer 4, the reinforcing cover portion 3e and the exhaust silencer 4 are sealed with bolts 22 and 22 via the gasket 23. Connected. That is, by integrally forming the reinforcing cover portion 3 e on the exhaust manifold 3, the exhaust manifold 3 and the exhaust silencer 4 can be connected at the exhaust inlet portion 4 a of the exhaust silencer 4 without using the reinforcing plate 6. It has a structure.
[0020]
By adopting such a structure, the conventionally used reinforcing plate 6 and flanges welded to the inlet pipe 14 become unnecessary, and the number of parts can be reduced.
Further, by integrally forming the reinforcing cover portion 3e on the exhaust manifold 3, it is possible to reduce the resonance of the exhaust silencer due to vibration from the engine 1 body. Furthermore, the reinforcing cover portion 3e is a cast article and has a relatively high degree of freedom in shape as compared with the reinforcing plate 6 that is a press product, and the reinforcing cover portion 3e has an optimum shape with respect to the exhaust silencer 4. And can be arranged.
[0021]
Subsequently, a reference example will be described with reference to FIGS. In the prior art, as shown in FIGS. 8 and 9, on the exhaust passage side of the connection portion between the exhaust manifold 3 and the exhaust silencer 4, the outer cylinder 18, the inlet pipe 14, the reinforcing plate 6, The flange 17 attached to the inlet pipe 14 and the anti-vibration stay 7 attached to the outer cylinder 18 of the exhaust silencer 4 are separate parts and are joined by welding. However, in such a structure, the number of parts is large, and the number of welded portions is increased accordingly. Therefore, the assembly process is complicated and the productivity is not good. Further, since the reinforcing plate 6 and the anti-vibration stay 7 are press products, the degree of freedom in shape is low.
[0022]
Therefore, in the reference example , as shown in FIG. 5, the outer cylinder 18 of the exhaust silencer 4 is formed integrally with the exhaust manifold 3 by molding with a casting. That is, the reinforcing plate 6 and the anti-rest 7 that are conventionally used as separate parts when connecting the exhaust silencer 4 and the exhaust manifold 3 are formed integrally with the exhaust manifold 3, and the exhaust manifold 3 is further connected to the exhaust silencer. 4 outer cylinders 18 and a casting.
[0023]
By adopting such a structure, the number of parts can be reduced, and it is possible to greatly reduce the number of welding locations, thereby simplifying the assembly process and improving productivity. In addition, by forming the outer cylinder 18 of the exhaust silencer 4, which has conventionally been formed of sheet metal, by casting integrally with the exhaust manifold 3, the sound emitted from the surface of the outer cylinder 18 can be reduced. In addition, deformation due to temperature change can be suppressed and occurrence of metal fatigue can be reduced. Furthermore, resonance of the exhaust silencer due to vibration from the main body of the engine 1 can be prevented.
[0024]
Next, a structure for preventing resonance of the exhaust silencer 4 by improving the shape of the anti-rest stay 7 will be described with reference to FIGS. 6 and 11 as a reference example . As shown in FIG. 11, the conventional anti-rest stay 7 is a bent product formed by bending a sheet metal into a substantially V shape in a side view having a substantially horizontal bottom portion 7 a and curved portions 7 b and 7 b. Since such a conventional anti-rest stay 7 is a bent product of sheet metal, in order to reinforce the anti-rest stay 7, the thickness of the plate is increased or a rib plate or the like which is a separate part is welded. Although there are methods, these methods are disadvantageous in terms of cost, and the resonance of the exhaust silencer 4 due to vibration from the main body of the engine 1 has not been prevented.
[0025]
Therefore, in the anti-vibration stay 27 of the present reference example , the box portion 27a is formed by making the portion that was the bottom 7a of the conventional anti-vibration stay 7 into a box shape. That is, as shown in FIG. 6, the anti-rest stay 27 in the present reference example is a bent product of a single sheet metal, but the side plate portions 27c and 27c are installed below the curved portions 27b and 27b. And is formed as a box portion 27a which is a box. By adopting such a shape, resonance of the exhaust silencer 4 due to vibration from the engine 1 body can be avoided, and durability against vibration fatigue can be improved. In addition, since the bottom of the anti-rest 27 is box-shaped, it can be manufactured by a drawing (press) mold, so that the accuracy can be easily improved, and the rounding radius of the corner of the box 27a is arbitrarily set. It is possible to relieve the stress applied to the anti-vibration stay 27 and the stress caused by the load of the exhaust silencer 4.
[0026]
Further, as a reference example , a structure for preventing resonance of the exhaust silencer 4 by improving the reinforcing plate 6 welded to the outer cylinder 18 of the exhaust silencer 4 as a reinforcement for the inlet pipe 14 of the exhaust silencer 4. This will be described with reference to FIGS. As shown in FIG. 10, the conventional reinforcing plate 6 includes a column portion 6a, a curved portion 6b which is a plate-shaped member having a substantially U shape in side view, formed above the column portion 6a, and the curved portion 6b and the column. The reinforcing part 6c formed in the longitudinal direction of the exhaust silencer 4 to reinforce the part 6a and the pushing rib 6d are formed integrally with the longitudinal direction of the exhaust silencer 4 by pressing or the like. And formed vertically. However, since such a push rib 6d is formed by a press or the like, the shape and height are forcibly limited, so that the resonance of the exhaust silencer 4 due to vibration from the engine 1 body is sufficiently suppressed. The exhaust silencer 4 was rapidly deteriorated due to vibration fatigue or the like.
[0027]
Therefore, in the reinforcing plate 26 which is an attachment member in the present reference example , the structure other than the conventional reinforcing plate 6 and the pushing rib 6d is substantially the same, and the exhaust silencer is provided at the place where the pushing rib 6d is formed on the reinforcing plate 6. Reinforcing ribs 28 which are plate-like members are welded and reinforced in a direction perpendicular to the longitudinal direction of the vessel 4. Thus, by reinforcing with welded reinforcing ribs 28 as separate members, Hakare easily improve the support rigidity, such as by the reinforcing ribs 28 in the thickness, the reinforcing rib by the shape of the reinforcing plate 26 It becomes possible to make 28 an arbitrary shape, and the freedom degree in design becomes high. Moreover, since the resonance of the exhaust silencer 4 due to vibration from the engine 1 body can be reduced, the vibration fatigue life of the exhaust silencer 4 can be extended.
[0028]
As described above, in the exhaust manifold connected to the exhaust inlet portion of the exhaust silencer of the engine, the outer cylinder portion of the exhaust silencer and the exhaust manifold are integrally formed. The support part is integrally formed with the exhaust silencer and the exhaust manifold, and it is possible to reduce the number of parts, and the number of welding points and cost saving associated therewith, and the support rigidity of the exhaust silencer can be improved with an easy configuration. Moreover, the radiation sound from the exhaust silencer outer cylinder surface can be reduced.
[0029]
Further, in the vibration-proof support member interposed on the support portion side of the connection portion between the exhaust silencer of the engine and the exhaust manifold, the support member is a box shape, so that the support rigidity of the exhaust silencer can be improved, The stress applied to the vibration-proof support member can be relaxed and durability against vibration fatigue can be improved.
[0034]
In addition, in the mounting member interposed on the exhaust passage side of the connection portion between the exhaust silencer of the engine and the exhaust manifold, a reinforcing rib is provided on the mounting member by welding in a direction perpendicular to the longitudinal direction of the exhaust silencer. The support rigidity of the exhaust silencer can be improved, and the shape such as the thickness of the reinforcing rib can be formed regardless of the shape of the mounting member, and the degree of freedom in design is improved.
[0035]
【The invention's effect】
Since the present invention is configured as described above, the following effects can be obtained.
[0036]
As shown in claim 1, the exhaust silencer (3b) is connected to the exhaust outlet (3b) of the exhaust manifold (3) at the connection between the exhaust manifold (3) of the engine (1) and the exhaust silencer (4). The exhaust inlet (4a) of 4) is connected in communication, and the exhaust outlet (3b) of the exhaust manifold (3) and the exhaust inlet (4a) of the exhaust silencer (4) are connected in communication. If the side is defined as the “exhaust passage side” and the opposite side in the longitudinal direction of the exhaust silencer (4) with respect to the “exhaust passage side” as the “support portion side”, the exhaust silencer (4) is parallel to the exhaust silencer (4). An extension portion (3d) formed integrally is formed on the “supporting portion side” of the exhaust manifold (3) arranged in the manner described above, and the extension portion (3d) constitutes the exhaust silencer (4). since directly linked to the outer tube (18), forming a support portion of the other side of the exhaust muffler integrally with the exhaust manifold Come, high degree of freedom in shape of the support portion, Hakare high rigidity, also reduce the number of parts is also possible.
In addition, resonance of the exhaust silencer due to vibration of the engine body can be prevented with an easy configuration, and since an exhaust manifold connected in the exhaust path is used, a vibration-proof structure can be used without using separate parts. Compactness can be achieved.
[0037]
As shown in claim 2, the exhaust silencer (3b) of the exhaust manifold (3) is connected to the exhaust silencer (3b) at the connection between the exhaust manifold (3) of the engine (1) and the exhaust silencer (4). The exhaust inlet (4a) of 4) is connected in communication, and the exhaust outlet (3b) of the exhaust manifold (3) and the exhaust inlet (4a) of the exhaust silencer (4) are connected in communication. The exhaust manifold side of the “exhaust passage side” is defined as the “exhaust passage side” and the “exhaust passage side” opposite to the longitudinal direction of the exhaust silencer (4) as the “support portion side”. 3) A reinforcing cover portion (3e) is integrally formed by extending a part of the exhaust pipe, and an inlet pipe (14) of the exhaust silencer (4) is inserted into the reinforcing cover portion (3e) to cover the reinforcing cover portion (3e). And the reinforcing cover (3e) and the outer cylinder (18) constituting the exhaust silencer (4). Having connected by sealing engagement with the gasket (23), the freedom of the shape of the reinforcement cover portion is increased by the reinforcing plate which has been used as a separate part is formed integrally with the exhaust manifold, an exhaust silencer The connection rigidity at the exhaust inlet of the engine can be improved, and resonance of the exhaust silencer due to vibration from the engine body can be avoided.
[Brief description of the drawings]
FIG. 1 is a front view showing a schematic configuration of an engine.
FIG. 2 is a side view of the prior art of FIG.
FIG. 3 is a partial front sectional view showing a first embodiment of an anti-vibration structure for an engine exhaust silencer.
FIG. 4 is also a diagram showing a second embodiment.
FIG. 5 is also a diagram showing a reference example .
FIG. 6 is a perspective view of a steady stay according to a reference example .
FIG. 7 is a perspective view of a reinforcing plate of a reference example .
FIG. 8 is a perspective view showing a vibration isolating structure of a conventional engine exhaust silencer.
FIG. 9 is also a partial front sectional view.
FIG. 10 is a perspective view of a conventional anti-rest stay.
FIG. 11 is a perspective view of a conventional reinforcing plate.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Engine 3 Exhaust manifold 3d Extension part 3e Reinforcement cover part 4 Exhaust silencer 18 Outer cylinder 26 Reinforcement plate 27 Anti-rest stay 28 Reinforcement rib

Claims (2)

At the connection between the exhaust manifold (3) of the engine (1) and the exhaust silencer (4), the exhaust inlet (3b) of the exhaust manifold (3) is connected to the exhaust inlet ( 4a) is connected in communication, and the side where the exhaust outlet (3b) of the exhaust manifold (3) and the exhaust inlet (4a) of the exhaust silencer (4) are connected in communication is referred to as “exhaust passage side”. When the opposite side in the longitudinal direction of the exhaust silencer (4) with respect to the “exhaust passage side” is defined as the “support portion side”, an exhaust manifold (parallel to the exhaust silencer (4)) 3) An integrally formed extension part (3d) is formed on the “support side” of 3), and the extension part (3d) is directly connected to the outer cylinder (18) constituting the exhaust silencer (4). An anti-resonance structure for an exhaust silencer of an engine characterized by being connected . At the connection between the exhaust manifold (3) of the engine (1) and the exhaust silencer (4), the exhaust inlet (3b) of the exhaust manifold (3) is connected to the exhaust inlet ( 4a) is connected in communication, and the side where the exhaust outlet (3b) of the exhaust manifold (3) and the exhaust inlet (4a) of the exhaust silencer (4) are connected in communication is referred to as “exhaust passage side”. When the opposite side of the exhaust silencer (4) in the longitudinal direction is the “support side” with respect to the “exhaust passage side”, a part of the exhaust manifold (3) on the “exhaust passage side” is extended. The reinforcing cover portion (3e) is integrally formed by installing, and the reinforcing pipe portion (3e) is inserted and covered with the inlet pipe (14) of the exhaust silencer (4). 3e) and the outer cylinder (18) constituting the exhaust silencer (4), the gasket (23) Resonant structure for preventing the exhaust muffler, characterized in that connected by sealing engagement through.

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