JP3347905B2 - Exhaust muffler - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust muffler, and more particularly to an exhaust muffler in which the muffler main body is fixed at a fixed position by a mounting bolt penetrating the muffler main body.

[0002]

2. Description of the Related Art In an exhaust muffler of this type, the inside of the muffler body is divided into a plurality of exhaust expansion chambers by a separator, but in the conventional structure, the separator and a collar through which mounting bolts are inserted are provided. Is a separate part, and the collar and the mounting bolt are arranged so as to be substantially perpendicular to the separator and penetrate through the separator.

In general, in an exhaust muffler, a separator is sandwiched between joining surfaces of the muffler main body, and the separator and an exhaust inflow pipe or an exhaust pipe penetrating the separator are separate parts. (See, for example, Japanese Utility Model Laid-Open No. 51-103146).

[0004]

If the separator in the muffler main body and the mounting bolt insertion collar are formed separately as in the prior art, the number of parts increases, the cost increases, and the assembly workability decreases. Problem.

Similarly, if the separator and the exhaust inflow pipe or the exhaust pipe are formed separately, there are problems such as an increase in the number of parts, an increase in cost, and a reduction in assembly workability.

Further, since the separator is sandwiched between the joining surfaces of the muffler main body, the degree of freedom of the installation position of the separator and, consequently, the degree of freedom of volume distribution (so-called tuning) of the exhaust expansion chamber in the muffler main body are not small. There is a problem of being restricted.

[0007] The present invention has been made in view of such circumstances, and has as its object to provide an exhaust muffler having a simple structure that solves these problems.

[0008]

According to one aspect of the present invention, there is provided an exhaust muffler in which the muffler body is fixed at a fixed position by a mounting bolt penetrating the muffler body. A separator for partitioning the inside into a plurality of exhaust expansion chambers is composed of first and second plate-shaped separator halves which are bonded to each other by polymerization .
Both end surfaces of the first and second plate-shaped separator halves are
First and second collar forming portions which respectively abut against corresponding inner end faces of the body, and form , on the first and second separator halves, a bolt insertion collar for inserting the mounting bolt in cooperation with each other. Exhaust gas flows into the muffler body
First and second forming inflow pipes that cooperate with each other
Exhaust gas is discharged outside the muffler body
First and second forming cooperating discharge pipes
And a discharge pipe forming section , respectively ,
Insert the end into the exhaust outlet formed in the muffler body.
On both sides of the first and second plate-shaped separator halves.
Are integrated with locking flanges extending in the direction away from each other.
The two locking flanges are connected to each other and correspond to the muffler body.
Claim 2 characterized by being brought into contact with the inner side surface.
The invention, in addition to the feature, before Symbol muffler body, together with formed by joining a plurality of body components each other, characterized in that said separator and its joint surface is substantially orthogonal.

[0009]

According to the above features of the present invention, a collar for inserting the mounting bolt of the muffler main body into the separator that partitions the inside of the muffler main body into a plurality of exhaust expansion chambers, and a flow of the exhaust gas are provided.
Are integrated and input pipes and discharge pipes, their from these to be a single component, the number of parts is reduced as compared with its conventional structure these were not a separate part, assembling workability Is also good. Also, in the assembly state of the muffler body
In addition, insert the end of the discharge pipe into the exhaust outlet,
Inside the muffler body with locking flanges connected to both sides of the generator
Both surface contact on the side and separator on the inner end of the muffler body
The separator is positioned inside the muffler body by the abutment of the end face.
The separator can be securely held in the muffler body.
There is no need to hold it between the joining surfaces,
The installation position and shape of the separator are
Since it can be set without major restrictions on the position of the surface,
Change the setting of the separator installation position and shape.
Change in the setting of the volume distribution of the exhaust expansion chamber inside the
It is relatively easy.

Further, according to the above feature of the invention of claim 2 ,
Although the separator cannot be sandwiched between the joining surfaces of the muffler main body because the joining surface of the muffler main body and the separator are substantially orthogonal to each other, the separator is securely fixed at a fixed position in the muffler main body as described above .

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show a first embodiment of the present invention. In particular, FIG. 1 is a partially cutaway front view of an OHC engine equipped with an exhaust muffler according to the first embodiment, and FIG. 1 is an enlarged sectional view taken along line 2-2 of FIG. 1, FIG. 3 is a perspective view showing a separator of the exhaust muffler, and FIG. 4 is an exploded perspective view showing the entire exhaust muffler. FIG. 5 is a sectional view similar to FIG. 2, showing an exhaust muffler according to a second embodiment of the present invention. FIG. 6 is a sectional view similar to FIG. 2, showing an exhaust muffler according to a third embodiment of the present invention. FIG. 7 is a sectional view of the fourth embodiment of the present invention.
It is an exploded perspective view showing the separator of the exhaust muffler concerning an example.

First, in FIG. 1, a cylinder head H of a general-purpose air-cooled single-cylinder OHC engine E in which a crankshaft 1 is disposed in a vertical direction is provided with an intake port 4 having an inner end opened to a combustion chamber 2 and extending to one side thereof. And an exhaust port 3 having an inner end opened to the combustion chamber 2 and extending to the other side.
These ports are opened and closed at predetermined timing by intake valves and exhaust valves (not shown). An outer end of the intake port 4 is detachably connected to the carburetor 5, and an outer end of the exhaust port 3 is connected to a pair of mounting bolts B on the exhaust muffler M.
Is detachably connected. An exhaust outlet e of the exhaust muffler M is closely opposed to a plurality of exhaust holes 6 formed in a cover C mounted on the cylinder head H so as to cover the muffler M. , Are discharged outside through the exhaust holes 6.

Next, a specific structure of the exhaust muffler M will be described with reference to FIGS. The muffler body 7 of the exhaust muffler M has a split structure, and the open ends of the first and second case halves 7 ₁ and 7 ₂ each having a bottom and open at one end are integrally joined. Be composed. That that the opening edge of each casing half _71, 7 ₂ are provided continuously to the coupling flange 7f _1, 7f ₂ is integral outwardly over the entire circumference thereof, the two coupling flanges 7f _1, 7f ₂ The two case halves 7 ₁ and 7 ₂ are air-tightly connected by caulking at least a part of them. The first and second case halves 7 ₁ and 7 ₂ are connected to the muffler main body 7.
Are composed of a plurality of main body components.

[0014] closed end 7a ₁ of the first case half ₇₁ of the engine closer includes one exhaust inlet 8, first bolt holes 9 ₁ a pair of aligned on both sides are formed, the flow first case half 7 inlet 8 so as to conform to the outer end of the exhaust port 3 ₁ closed end portion 7a ₁ is a cylinder head H
Is close to the outer end face. On the other hand, the closed end portion 7a ₂ of the second case half 7 ₂ and one exhaust outlet 10, the pair of the pair of second bolt holes corresponding to the first bolt holes 9 ₁ 9 ₂
Is formed.

[0015] In the muffler main body 7, the separator S is disposed for partitioning the internal space into a first exhaust expansion chamber C ₁ of the exhaust upstream side and a second exhaust expansion chamber C ₂ of the downstream side. The separator S has an inflow pipe Pi having an opening end on the cylinder head H side directly connected to the exhaust inflow port 8 so as to allow exhaust gas to flow into the muffler main body 7, and an inflow pipe Pi thereof.
A pair of bolt insertion collars Co, which also serve as bolt guide members, are provided on both sides of the pair of mounting bolts B, and a discharge pipe Po for discharging exhaust gas to the outside of the muffler body 7. The end 11 of the discharge pipe Po on the opposite side to the cylinder head H is
In order to form a so-called tail end of the exhaust muffler M, the exhaust muffler M is inserted into the exhaust outlet 10 and extends to the outside.
One open end forms the aforementioned exhaust outlet e. Wherein each of the color Co and introduction and discharge pipe Pi, Po extends substantially in parallel spaced apart from each other, moreover coupling flange 7f ₁ of the bonding surface (i.e. the first and second case halves _71, 7 ₂ of the muffler main body 7 , 7f ₂ ).

[0016] The separator S can be respectively formed of a metal plate which is composed of first and second separators half s _1, s ₂ are polymerized sintered wear each other, particularly a first separator half s ₁ second the first exhaust expansion chamber C _1, also the second separator halves s ₂ are made to face each second exhaust expansion chamber C _2. Its first separator half s _1, wherein the bolt collar Co, first collar forming part 12 respectively formed in the cross-section semicircular so that one half portion of each of the inlet pipe Pi and the discharge pipe Po ₁ has a first inflow pipe forming part 13 ₁ and the first discharge pipe forming part 14 ₁ is integrally molded, on the other hand, the second separator halves s _2, the bolt insertion color Co, inlet pipe Pi and discharge Pipe P
second collar forming part 12 ₂ respectively formed on the cross-section semicircular so that each of the other half of the o, the second inflow pipe forming portion 13 ₂ and the second discharge pipe forming portion 14 ₂ is integrally molded ing.

The first and second separator halves s ₁ ,
flat face contacting portion of the mutual s ₂ is integrally coupled with fixing means such as spot welding w at a plurality of positions,
In such a connected state, the first and second color forming sections 12 ₁ , 1
2 ₂ cooperate with each other to form a bolt B collar Co, the first and second inflow pipe forming portions 13 ₁ and 13 ₂ cooperate with each other to form the inflow pipe Pi, and further form the first and second discharge pipes. The parts 14 ₁ and 14 ₂ cooperate with each other to discharge pipe Po
Are formed respectively. The color Co and the pipes Pi, Po integrated with the separator S in this manner are integrated.
Function as reinforcing ribs, which can contribute to the improvement of the rigidity of the separator S itself.

[0018] One end of the first case half ₇₁ side of each separator half s _1, s ₂ is closely abuts against the inner end surface of the first case half ₇₁ over its entire surface, and each the other end surface of the second case half 7 ₂ side of the separator halves s _1, s ₂ also closely opposition to the inner end face almost entire surface of the second case half 7 ₂ except for the extending end portion 11 of the exhaust pipe Po I agree. Therefore, when fixing the exhaust muffler M to the cylinder head H by tightening the mounting bolts B, each of the separator halves s ₁ and s ₂ (particularly, the collar forming portions 12 ₁ and 12 ₂ ) exerts a tightening force of the bolts B. First and second case halves 7 while firmly receiving
_1, 7 and in the interval between ₂ they can function as a spacer to define the constant, the separator S which has been conventionally disposed to dispense the color of the separate parts.

Further, the first and second separator halves s ₁ and s
₂ , locking flanges 15 ₁ , 15 ₂ extending in directions away from each other are provided on one side edge in a direction orthogonal to each color Co.
Are integrally provided, and both locking flanges 15 ₁ , 15 ₂
Is closely abutting the inner surface of the first and second case halves 7 _1, 7 ₂ corresponding. Similar locking flanges 1 are also provided on the other side edges of the first and second separator halves s ₁ and s _2.
5 _1, 15 ₂ have been integrally joined to closely abut the corresponding inner surfaces of the first and second case halves _71, 7 _2.

[0020] The peripheral wall of the inlet pipe forming part 13 ₁ of the first separator half s _1, s _2, inlet pipe Pi and first between the exhaust expansion chamber C ₁ is the first small hole h ₁ number of communicating the, The first and second exhaust halves are formed in the flat portions of the first and second separator halves s ₁ and s _{2 on} the side of the inflow pipe Pi. expansion chamber C _1, C ₂ between a plurality of second small hole h ₂ for communicating, are bored eccentrically to the cylinder head H toward. More second circumferential wall of the discharge pipe forming part 14 ₂ of the separator halves s _2, a number of third small hole h ₃ for communicating between the discharge pipe Po and the first exhaust expansion chamber C ₁ is away from the cylinder head H It is eccentric to the side.

Next, the operation of the embodiment will be described. During the operation of the engine E, the exhaust gas flowing from the combustion chamber 2 through the exhaust port 3 into the inflow pipe Pi of the exhaust muffler M is
The first small hole h ₁ through enters the first exhaust expansion chamber C ₁ expands the primary, then the second exhaust expansion chamber C through the second small hole h _2
2 and secondary expansion, further reach the inside of the discharge pipe Po through the third small hole h ₃ , and are discharged to the outside through the discharge hole 6 of the cover C from the discharge outlet e which is the opening end. Thus, in the exhaust muffler M, the exhaust gas is exhausted into a plurality of exhaust expansion chambers C ₁ and C _2.
Are sequentially expanded in the process of sequentially passing through, thereby achieving the desired exhaust noise silencing effect.

When assembling the exhaust muffler M, the separator S is assembled by welding the first and second separator halves s ₁ and s ₂ in advance. The extension end 11 of the discharge pipe Po of the separator S is connected to the second end.
While fitted to the exhaust outlet 10 of the case half 7 _2, wherein the separator S so as to sandwich the first and second case halves _71, 7 between _2, first and second case halves 7 _1, 7
The connecting flanges 7f ₁ and 7f ₂ at the opening edges of the _two are joined together by caulking. In this coupled state, the discharge pipe extension end 11 is fitted into the exhaust outlet 10, the locking flanges 15 ₁ , 15 ₂ are in surface contact with the inner surface of the muffler body 7, and the first and the second The separator S can be held at a fixed position in the muffler main body 7 by abutting the _two end surfaces of the separator S against the inner end surfaces of the closed end portions 7a ₁ and 7a _{2 of the} two case halves 7 ₁ and 7 ₂ .

[0023] In assembling this way the exhaust muffler M obtained in the engine, matches the first case half ₇₁ of the exhaust inlet 8 of the muffler main body 7 to the exhaust port 3 the outer end of the cylinder head H In this state, a pair of mounting bolts B are
Each case half _71, 7 ₂ of the bolt holes 9 _1, 9 _2, and may be fastened to the cylinder head H through the bolt collar Co separator S.

Meanwhile, in the exhaust muffler M, a collar Co for allowing the mounting bolt B to pass through a separator S that partitions the inside of the muffler body 7 into a plurality of exhaust expansion chambers C ₁ and C _2.
In addition, the exhaust inflow pipe Pi and the exhaust pipe Po
Are integrated, and they can be made into a single part, so that the number of parts becomes extremely small and the assembling workability becomes very good as compared with the conventional structure in which they are separate parts.

In particular, as in this embodiment, the separator S
When the center lines of the color Co and the respective pipes Pi and Po are aligned on the bisecting plane of the muffler body 7, the first and second separator halves s ₁ and s ₂ constituting the separator S are It can have almost the same shape except for the first and third small holes h ₁ , h _{3 and the} like.
₁ first and second case halves 7 constituting, 7 _2, because most can be formed in the same shape except for the exhaust inlet 8 and outlet 10 or the like, they separator halves s _1, s
₂ and the case halves 7 ₁ and 7 ₂ can be mass-produced and contribute to cost reduction.

The first and second muffler main body 7
Case half _71, 7 becomes impossible Kyotome the separator S between the joining surfaces in relation to substantially perpendicular to the junction plane and the separator S between ₂ constant within the muffler main body 7 separator S by mounting bolts B Can be securely fixed in position. In addition, since the installation position and shape of the separator S can be set without great restrictions on the position of the joint surface, the setting of the installation position and shape of the separator S can be changed, and the exhaust expansion chamber C in the muffler main body 7 can be changed. _1, a setting change of the volume distribution of C ₂ relatively easily (i.e. and position of the joint surfaces, each case half _71, 7 ₂ forms, without specially changing the size and the like) to perform the it can.

FIG. 5 shows a second embodiment of the present invention. In this embodiment, the flat portion of the separator S is not on the same plane, and the middle portion of the separator S is bent or curved. Or FIG. 6 shows a third embodiment of the present invention. In this embodiment, the flat portions of the separator S are arranged on one inclined plane. If the form of the separator S and the installation position with respect to the muffler main body 7 are appropriately changed as shown in these embodiments, the volumes of the exhaust expansion chambers C ₁ and C ₂ in consideration of the back pressure, noise, etc. of the exhaust muffler M are considered. Adjustment (tuning) of the ratio distribution can be easily performed.

FIG. 7 shows a fourth embodiment of the present invention. In this embodiment, the first and second separators half s _1, s discharge pipe forming part 14 ₁ of _2, 14 ₂ between the cylindrical exhaust gas purifying catalyst Ca the separators halves while clamped to s ₁ to , S ₂ are welded to form a separator S. Thus, according to this embodiment, the separator S is also used as the catalyst carrier holding the catalyst Ca.

Although one embodiment of the present invention has been described above, the present invention is not limited to the embodiment, and various embodiments are possible within the scope of the present invention. For example, in the above embodiment, the present invention is applied to an air-cooled single-cylinder engine. However, it goes without saying that the present invention can be applied to an air-cooled multi-cylinder or water-cooled single-cylinder or multi-cylinder engine. Further, the number of mounting bolts B (accordingly, color Co) is not limited to two as in the illustrated example, but may be one or three or more. Further, the color Co does not necessarily need to be arranged on the bisecting horizontal plane of the muffler body or on both sides of the inflow pipe Pi. Further, although the cylinder head H is shown as a support portion of the muffler main body 7 in the illustrated example, the muffler main body may be supported by another appropriate portion, for example, a cylinder block or the like.

[0030]

As described above, according to the invention of each claim,
Separator that partitions the muffler body into multiple exhaust expansion chambers
But the color for bolt insertion, the exhaust inlet pipe and discharge
Since it also serves as a pipe, the number of parts can be reduced accordingly, which can contribute to cost reduction and improvement in assembly workability. Also, in the assembled state of the muffler body
Is inserted into the exhaust pipe at the end of the discharge pipe and separated
The inner surface of the muffler body with the locking flanges connected to both side edges
Surface contact with the separator and both ends of the separator on the inner end surface of the muffler body
The separator in place in the muffler body
The separator can be connected to the muffler body because it can be securely held.
There is no need to hold it between the surfaces,
Change the setting of the installation position and shape of the separator,
Setting change of volume distribution of exhaust expansion chamber in muffler body
Is relatively easy.

According further to the invention of claim 2, since the bonding surface and the separator of the muffler body was substantially perpendicular, but that such impossible Kyotome a separator between the bonding surfaces of the muffler body, the
Thus, the separator can be securely fixed at a fixed position in the muffler main body.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view of an OHC engine equipped with an exhaust muffler according to a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG.

FIG. 3 is a perspective view showing a separator of the exhaust muffler.

FIG. 4 is an exploded perspective view showing the entire exhaust muffler.

FIG. 5 shows an exhaust muffler according to a second embodiment of the present invention.
Sectional view similar to FIG.

FIG. 6 shows an exhaust muffler according to a third embodiment of the present invention.
Sectional view similar to FIG.

FIG. 7 is an exploded perspective view showing a separator of an exhaust muffler according to a fourth embodiment of the present invention.

[Explanation of symbols]

B: Mounting bolts C1, C2: _First and _second exhaust expansion chambers as exhaust expansion chambers Co: Bolt insertion collar H: ····· Cylinder head as muffler main body support part Pi ······ Inflow pipe Po ········ Discharge pipe S. ······· Separator s ₁ , s ₂ ··· · First and second separator halves 7 ········ Muffler main body 7 ₁ , 7 ₂ ··· First and second case halves 12 ₁ and 12 ₂ ··· 1, the second color forming portions 13 _1, 13 ₂ ... first, second inflow pipe forming part 14 _1, 14 ₂ ... first, second discharge pipe forming portion

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F01N 1/08 F01N 7/18

Claims (2)

(57) [Claims] 1. An exhaust muffler in which a muffler body (7) is fixed in a fixed position by a mounting bolt (B) penetrating the muffler body (7). Room (C ₁ , C
₂ ), the separator (S) is composed of first and second plate-like separator halves (s ₁ , s ₂ ) bonded together by polymerization, and the first and second plate-like separator halves are joined together.
Both end faces of the body (s ₁ , s ₂ ) are paired with the muffler body (7).
Each is abutting the inner end face of response, that the first and second separators half (s _1, s _2), the mounting bolts (B) to cooperate with one another the bolt collar (Co) for inserting the First and second color forming portions (1
2 ₁ , 12 ₂ ) and exhaust gas flow into the muffler body (7).
The inlet pipes (Pi) are formed in cooperation with one another.
First and second inflow pipe forming portions (13 ₁ , 13 ₂ );
A discharge pipe for discharging exhaust gas outside the muffler body (7)
(Po) in cooperation with each other
Ip forming portions (14 ₁ , 14 ₂ ) are provided respectively ,
Connect the end (11) of the discharge pipe (Po) to the muffler body
(7) into the exhaust outlet (10) formed,
Both sides of the first and second plate-shaped separator halves (s ₁ , s ₂ )
Locking flanges at the edges that extend away from each other
(15 ₁ , 15 ₂ ) are connected in series and their locking
(15 ₁ , 15 ₂ ) to the muffler body (7)
An exhaust muffler characterized by abutting against the inner surface of the exhaust muffler. 2. The muffler body (7) is formed by joining a plurality of body components (7 ₁ , 7 ₂ ) to each other, and the joining surface thereof is substantially orthogonal to the separator (S). wherein the exhaust muffler according to claim 1.