DE202017107307U1 - Switchable silencer for the exhaust gas flow of an internal combustion engine, especially in a motorcycle, as well as exhaust system with switchable silencer - Google Patents

Abstract

Acoustic damper (S) for the exhaust gas flow (A) of an internal combustion engine, with a first and second pipe section (S1, S2) leading a first and second partial flow (A1, A2) of the exhaust gas flow (A), a transition duct (D2) and a damping channel (D3) between the pipe sections (S1, S2), and a first switchable flap (K1) in the first pipe section (S1) between transition duct (D2) and damping duct (D3) and a second switchable flap (K2) in the second Pipe section (S2) in the direction of the exhaust gas flows (A1, A2) behind the damping channel (D3), so that at a the pipe sections (S1, S2) shut-off position of the flaps (K1, K2), the first partial flow (A1) through the transition channel ( D2) in the second pipe section (S2) and both partial flows (A1, A2) are returned through the damping channel (D3) in the first pipe section (S1).

Description

The invention relates to a switchable silencer for the exhaust gas flow of an internal combustion engine and an exhaust system with such a switchable silencer.

The muffler in the exhaust system of an internal combustion engine is used to reduce the excessive, often perceived by the environment as bang-like combustion and ejection noise of the cylinder to an appropriate volume. This can be determined by law. For this purpose, for example, mufflers are known for motorcycles, which are usually arranged radially concentrically around the exhaust pipe and thus have a large diameter. Particularly in the case of unclothed motorcycles, the exhaust system runs well visible to the outside and thus influences the perception of the motorcycle. The problem arises that such exhaust systems are perceived with mufflers of large diameter of persons as unaesthetic.

The invention is based on the object to provide a silencer with the smallest possible dimensions for an internal combustion engine.

The object is achieved with the muffler specified in claim 1 and the exhaust system specified in claim 7. Advantageous further embodiments of the invention are specified in the subclaims.

The embodied according to the invention for the exhaust gas flow of an internal combustion engine muffler has a first and second pipe section, which carry a first and second partial flow of the exhaust gas flow, a transitional channel and a damping channel between the pipe sections, a first switchable flap in the first piece of pipe between the transitional channel and damping channel and a second switchable flap in the second tube piece in the direction of the exhaust gas flows behind the damping channel, so that at a shut off the pipe sections position of the flaps, the first partial flow passed through the transition channel into the second piece of pipe and both partial flows are returned through the damping channel in the first piece of pipe. The silencer according to the invention is particularly suitable for a motorcycle with an internal combustion engine. When the flap position is open, the partial flows of the exhaust gas flow flow through the respective pipe sections approximately unhindered and thus emerge from the pipe sections almost without damping. The exhaust gas flow is thus released almost unattenuated to the environment.

In operating states of the internal combustion engine, in which an undamped exhaust gas flow emission would result in exceeding the normalized sound limits, the exhaust gas flow must be damped. Such operating conditions are, for example, in a motorcycle at a standstill, the operation of the internal combustion engine with half or three quarters of the rated speed or driving the acceleration of the motorcycle from a speed of 50 kilometers per hour in the second or third gear under full load of the engine.

The damping of the exhaust gas flow is initiated by closing the first and second flap in the first and second pipe sections. The cross-section of the pipe sections is almost completely blocked by the flaps in the closed switching position, so that a flow of the pipe section past the flaps almost can not be done.

The cross section of the first tube is blocked between the transition channel and the damping channel through the first flap. Thus, the further flow along the first pipe section is approximately prevented and the entry of the first partial flow into the transition duct to the second pipe section is favored. There is thus a transfer of the first partial flow from the first pipe section into the second pipe section.

The cross-section of the second tube piece is blocked in the direction of the exhaust gas flow behind the transition and damping channel, so that an exit of the first and second partial flow from the second tube piece can not take place approximately. There is thus a stowage of the two partial flows in the second piece of pipe in front of the second flap.

It is thus favored the entry of both partial flows in the damping channel. This runs according to the transitional channel between the first and second pipe section. When flowing through the damping channel is carried out by reflection or absorption of the vibrations, for example, a damping of the exhaust gas flow. Both partial flows thus occur attenuated from the damping channel in the flow direction behind the first flap in the first piece of pipe. The exhaust gas flow is thus returned by the damping channel from the second pipe section in the first pipe section and exits through the first pipe section from the muffler.

A designed according to the invention muffler is particularly compact executable and can thus advantageously be arranged to save space between two undamped exhaust pipes, for example, a motorcycle. Thus, one is According to the invention muffler particularly advantageous as a retrofit for motorcycles used. In this case, a large diameter is particularly advantageously avoided in a muffler and especially in a motorcycle does not affect the aesthetic perception by a person. Furthermore, a muffler designed according to the invention has the advantage that in non-damping load conditions of the internal combustion engine, the flaps can be opened and then the exhaust gas flow passes through the muffler unattenuated. The acoustic perception of the combustion and ejection noise is not affected.

According to a further advantageous embodiment of the invention, the transition channel is designed as an interference tube. An interference tube is a connecting channel between two pieces of pipe of an exhaust system, whose geometry is tuned to the effect of constructive interference between the vibrations of both partial flows and thus the mutual influence of the partial flows. In this case, in particular the emission of the exhaust gas is advantageously supported. The advantageous embodiment of the transition duct as an interference tube thus advantageously improves the outflow of the exhaust gas flow from a silencer according to the invention.

In a further advantageous embodiment of the invention, the damping channel at the transitions to the pipe sections each have a flow grid. When flowing through the grid, the support of the refraction of the oscillation and the linearization of the exhaust gas flow and thus advantageously an improvement of the damping effect of a silencer according to the invention takes place.

In a further advantageous embodiment of the invention, transition duct and damping duct are arranged in a housing. Transition channel and damping channel thus form a compact unit that is advantageous in a simple way to save space on the pipe sections can be applied. In this case, the visibility of the silencer according to the invention is advantageously reduced and thus does not impair the aesthetic perception, especially in a motorcycle.

According to a further advantageous embodiment of the invention, the pipe pieces are spaced from each other and the housing is placed in the gap between the pipe sections on the outer surfaces thereof. The housing is thus deeper in the space between the pipe sections. Advantageously, the visibility of the silencer according to the invention is further reduced.

Particularly advantageously, the pipe sections may have a diameter in the range of 50 mm to 70 mm. Pipe pieces with such a cross section are advantageously low resistance flowed through. Furthermore, this does not affect the aesthetic perception of motorcycles in particular.

An exhaust system with a muffler designed according to the invention as a rear muffler also has the advantages described.

• 1 einen beispielhaften, gemäß der Erfindung ausgeführten Schalldämpfer in einer liegenden isometrischen Draufsicht,
• 2 den Schalldämpfer von 1 mit absperrender Stellung der Klappen in einer seitlichen Draufsicht,
• 3 den Schalldämpfer von 1 mit offener Stellung der Klappen in einer Draufsicht,
• 4 den Schalldämpfer von 3 mit offener Klappenstellung in einer frontalen Draufsicht auf die Ausströmungsseiten der Rohrstücke, und
• 5 den Schalldämpfer von 1 mit halboffener bzw. halbabsperrender Klappenstellung in einer seitlichen Draufsicht.

The invention and further advantageous embodiments thereof are explained in more detail below with reference to the figures briefly mentioned. It shows

• 1 an exemplary, executed according to the invention muffler in a horizontal isometric plan view,
• 2 the silencer of 1 with shut-off position of the flaps in a lateral plan view,
• 3 the silencer of 1 with open position of the flaps in a plan view,
• 4 the silencer of 3 with open flap position in a frontal plan view of the outflow sides of the pipe sections, and
• 5 the silencer of 1 with halboffener or halbabsperrender flap position in a lateral plan view.

As shown in 1 points the muffler S for the exhaust gas flow A an internal combustion engine, in particular in a motorcycle, a first pipe section S1 and a second piece of pipe S2 on. The pipe sections advantageously have a diameter in the range of 50 mm to 70 mm and are advantageously made of stainless steel. The pipe sections are open at their front ends. So has the first piece of pipe S1 a first inflow side S11 and a first outflow side S12 and the second piece of pipe S2 a second inflow side S21 and a second outflow side S22 on.

According to the invention, the silencer S between the pipe sections S1 . S2 a transition channel D2 and a damping channel D3 on. These are each via openings with the pipe sections S1 . S2 connected. Such is the transition channel D2 via a first flow opening D21 with the first piece of pipe S1 and a second flow opening D22 with the second piece of pipe S2 connected. The damping channel D3 is over a third flow opening D31 with the first piece of pipe S1 and a fourth flow opening D32 with the second piece of pipe S2 connected. The damping channel D3 has advantageous at the transitions to the pipe sections S1 . S2 in each case a flow grid. In the present advantageous embodiment, the first and second flow openings D21 . D22 as through holes and the third and fourth flow openings D31 . D32 advantageously designed as a flow grid.

The silencer S furthermore has according to the invention a first switchable flap K1 and a second switchable flap K2 a flap system K on. The first flap K1 is in the first piece of pipe S1 between transition channel D2 and damping channel D3 and the second flap K2 in the second piece of pipe S2 in the direction of the exhaust gas flows A1 . A2 behind the damping channel D3 arranged. The first and second flap K1 . K2 each have a first damper drive K11 and a second damper drive K21 mechanically adjustable. The valve drives K11 . K21 are to change the switching position via a flap control K3 controllable. The valve drives K11 . K21 and the flap control K3 are shown symbolically as cubes in the present figure.

The flaps K1 . K2 are shown in the present figure in the closed vertical switching position, in which the flow-through cross-section of the pipe sections S1 . S2 almost completely through the flaps K1 . K2 is locked. According to the invention in one of the pipe sections S1 . S2 Shut-off position of the flaps K1 . K2 the first partial flow from the first pipe section S1 through the transition channel D2 in the second piece of pipe S2 passed over and both partial flows through the damping channel D3 from the second piece of pipe S2 in the first piece of pipe S1 recycled. The currents through the muffler S will be explained in more detail with reference to the following figures.

According to the advantageous embodiment of the silencer according to the invention S from 1 are transitional channel D2 and damping channel D3 advantageous in a housing D1 arranged. The housing D1 exemplifies a base plate D11 , a cover plate D12 , a first face plate D13 and a second face plate D14 on. According to the advantageous embodiment of 1 the pipe pieces run S1 . S2 spaced apart so that the housing D1 in the gap S3 between the pipe sections S1 . S2 on their outer surfaces S13 . S23 can be placed flat. The housing D1 is thus through the first, second outer surface S13 . S23 the first, second piece of pipe S1 . S2 , the base and cover plate D11 . D12 as well as the first, second end plate D13 . D14 locked. The housing D1 is on the outside surfaces S13 . S23 arranged so that the first, second, third and fourth flow openings D21 . D22 . D31 . D32 in the closed to the outside housing D1 lead.

The interior of the housing D1 is through a partition D15 divided into two, each with the first and second flow opening D21 . D22 and the third and fourth flow openings D31 . D32 lead into one of the subspaces. The subspace between the first and second flow openings D21 . D22 is thus the transition channel D2 and the subspace between third and fourth flow openings D31 . D32 the damping channel D3 , The transition channel D2 is advantageously designed as an interference tube. The geometry of the transition channel D2 This is adapted to the achievement of constructive interference between the vibrations of both partial flows and thus the mutual influence of the partial flows. The damping channel D3 advantageously has a central, transverse to the flow direction arranged damping plate D33 on. The exhaust gas flow through the damping channel D3 flows around the damping plate D33 approximately U-shaped. The damping channel D3 thus has an inflow area D34 , a deflection area D35 and an outflow area D36 on. The currents through the muffler S will be explained in more detail with reference to the following figures.

An exhaust system according to the invention for an internal combustion engine with a silencer S according to one of the preceding claims, wherein the silencer S is designed as a silencer is not shown separately in the figures. Such an exhaust system can by simply flanging further pieces of pipe, in particular a manifold, to the muffler S be formed. According to the invention, the silencer according to the invention S designed as a silencer. In this case, more pipe sections are flanged only on the inflow sides of the pipe sections of the muffler and the exhaust gases are discharged to the outflow side of the muffler to the environment.

In 2 is a plan view of a silencer according to the invention S represented by an exhaust gas flow A is flowed through. The flaps K1 . K2 are in a locked switch position. According to the invention, the first flap K1 between transition channel D2 and damping channel D3 and the second flap K2 in the direction of the exhaust gas flow A behind the damping channel D3 arranged. The flows are shown in the figures only schematically and idealized by dashed lines.

The exhaust gas flow A has a first partial flow A1 and a second partial flow A2 on. The first partial flow A1 occurs at the first inflow side S11 in the first piece of pipe S1 and the second partial flow A2 on the second inflow side S21 in the second piece of pipe S2 one. The first partial flow A1 will be in front of the first one flap K1 dammed up and through the first flow opening D21 from the first piece of pipe S1 over the transition channel D2 through the second flow opening D22 in the second piece of pipe S2 reconciled. It thus flows in this area the entire exhaust gas flow A in the second piece of pipe S2 ,

The exhaust gas flow A is in the second piece of pipe S2 in front of the second flap K2 dammed up, so the exhaust flow A through the fourth flow opening D32 in the damping channel D3 flows. The fourth flow opening D32 is advantageously designed as a flow grid. The exhaust gas flow A flows in the inflow area D34 on the damping plate D33 along and in the deflection area D35 around the damping plate D33 in the outflow area D36 diverted. In the damping channel D3 supported by the passage through the flow grid and the flow around the damping plate D33 , an attenuation of the exhaust gas flow A , This occurs through the third flow opening D31 which is also advantageously designed as a flow grid, from the damping channel D3 in the first piece of pipe S1 and escapes through the first outflow side S12 into the environment. There is no exit of the exhaust gas flow A through the second outflow side S22 , The passage of the exhaust gas flow A through the damping channel D3 and their damping is thus only at shut off switching position of the flaps K1 . K2 ,

A muffler designed according to the invention S is thus particularly suitable for use in a motorcycle, especially a motorcycle. It can by the control device K3 about the valve drives K11 . K21 automatically a change in the flap position in response to the operating situation of the internal combustion engine. So can the flaps K1 . K2 for example, be closed automatically at a standstill at half or three quarters of the rated speed of the engine, so that the exhaust gas flow A is damped in this operating situation. In addition, the flaps K1 . K2 for example, when driving at full acceleration in the second or third gear from 50 km / h driving speed are automatically closed.

In 3 is the advantageous, executed according to the invention muffler S shown in a plan view, with the flaps K1 . K2 in an open, non-blocking switching position. The first partial flow A1 the exhaust gas flow A flows through the first piece of pipe almost unhindered S1 through the first inflow side S11 at the open flap K1 passing through the first outflow side S12 , The second partial flow A2 flows through the second piece of pipe approximately unhindered S2 through the second inflow side S21 at the opened second flap K2 passing through the second outflow side S22 , There is almost no inflow of the first or second partial flow A1 . A2 into the flow openings D21 . D22 . D31 . D32 of transition channel or damping channel D3 , There is thus no damping of the exhaust gas flow A ,

In 4 is the muffler S from 3 in a frontal side view of the first and second outflow side S12 . S22 shown. The first or second flap K1 . K2 in the first and second tube piece S1 . S2 are visible in the open non-blocking switching position through the pipe openings on the outflow sides. The housing D1 is in the gap S3 between the pipe sections S1 . S2 arranged. The base plate D11 of the housing D1 runs approximately in the middle region of the pipe sections S1 . S2 at the narrowest point between these. The cover plate D12 is in the outer area of the pipe sections S1 . S2 approximately tangential to the outer surfaces S13 . S23 arranged. Particularly advantageous is the muffler S in vertical alignment so that the pipe sections S1 . S2 are arranged one above the other, with the cover plate D11 oriented to the motorcycle held on this. The base plate D11 in the gap S3 between the pipe sections S1 . S2 is thus oriented to the outside and perceptible by persons. In this particularly compact design of a silencer according to the invention S its visibility for people is reduced and so the aesthetic perception of a person is not affected.

In 5 is the executed according to the invention muffler S shown, with the flaps K1 . K2 be in a semi-open or semi-blocking switching position. It thus flows in each case a proportion of the partial flows through the flow openings in the transition or damping channel and a proportion of the partial flows past them along the pipe sections. The first substream A11 the first partial flow A1 flows in the first piece of pipe S1 at the first flow opening D21 , the first flap K1 and the third flow opening D31 over and through the first outflow side S12 undamped from the muffler. The first substream A21 the second partial flow A2 flows in the second piece of pipe S2 at the second flow opening D22 , the fourth flow opening D32 and the second flap K2 over and through the second outflow side S22 unattenuated from the muffler S out.

The second substream A12 the first partial flow A1 in the first piece of pipe S1 flows in front of the first door K1 through the first flow opening D21 in the transitional channel D2 and through the second flow opening D22 in the second tube S2 one. The second substream A22 the second partial flow A2 flows through the second inflow side S21 in the second tube S2 one. The second substream A12 the first partial flow A1 and the second substream A22 the second partial flow A2 flow through the fourth flow opening D32 in the damping channel D3 and enter attenuated by the third flow opening D31 behind the first flap K1 in the first piece of pipe S1 out. The two subdued sub-currents A12 . A22 flow with the first undamped substream A11 in the first piece of pipe S1 along and through the first outflow side S12 from the muffler S out.

The silencer shown S with half-open or half-blocking switching position of the flaps K1 . K2 allows partial damping of the exhaust gas flow A , Further intermediate switching positions of the flaps are not shown in the figures.

LIST OF REFERENCE NUMBERS

S

Silencer for the exhaust gas flow of an internal combustion engine

S1, S2

First, second piece of pipe

S11, S21

First, second inflow side

S12, S22

First, second outflow side

S13, S23

First, second outer surface

S3

Gap between the first, second piece of pipe S1 . S2

K

flap system

K1, K2

First, second flap

K11, K21

First, second damper drive

K3

flap control

D1

casing

D11

baseplate

D12

cover plate

D13, D14

First, second face plate

D15

partition wall

D2

Transition channel between the pipe sections S1 . S2

D21, D22

first, second flow opening

D3

damping channel

D31, D32

third, fourth flow opening, in particular flow grid

D33

damping plate

D34

inflow

D35

deflection

D36

Ausströmungsbereich

A

exhaust gas flow

A1

first partial flow

A11, A12

first undamped, damped substream

A2

second partial flow

A21, A22

second undamped, damped substream

Claims (7)

Silencer (S) for the exhaust gas flow (A) of an internal combustion engine, with a first and a second pipe section (S1, S2), which guide a first and a second partial flow (A1, A2) of the exhaust gas flow (A), - A transition channel (D2) and a damping channel (D3) between the pipe sections (S1, S2), and - A first switchable flap (K1) in the first pipe section (S1) between the transition duct (D2) and damping channel (D3) and a second switchable flap (K2) in the second pipe section (S2) in the direction of the exhaust gas flows (A1, A2) behind the damping channel (D3), so - At a pipe sections (S1, S2) shut-off position of the flaps (K1, K2), the first partial flow (A1) through the transition channel (D2) in the second pipe section (S2) and passed both partial flows (A1, A2) through the damping channel (D3) are returned to the first pipe section (S1). Silencer (S) after Claim 1 , wherein the transition channel (D2) is designed as an interference tube. Silencer (S) after Claim 1 or 2 , wherein the damping channel (D3) at the transitions to the pipe sections (S1, S2) each having a flow grid. Silencer (S) according to one of the preceding claims, wherein the transition duct (D2) and the damping duct (D3) are arranged in a housing (D1). Silencer (S) after Claim 4 , wherein - the pipe sections (S1, S2) are spaced apart from each other, and - the housing (D1) in the gap (S3) between the pipe sections (S1, S2) on the outer surfaces (S13, S23) is placed. Silencer (S) according to one of the preceding claims, wherein the pipe pieces (S1, S2) have a diameter in the range of 50 mm to 70 mm. Exhaust system for an internal combustion engine with a silencer (S) according to one of previous claims, wherein the muffler (S) is designed as a rear muffler.

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