JPH0241292Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Object of the Invention and Field of Application) The present invention relates to a muffler for a turbocharged engine that is applied to an automobile turbocharger.

(Prior art and its problems) In the muffler of a conventional turbocharged vehicle, the exhaust passage remained constant regardless of whether the turbocharger was on or off. Therefore, when the turbocharger is on, in the high speed range, the exhaust pressure increases and the differential pressure across the turbocharger turbine decreases, resulting in a large ventilation resistance, which has the disadvantage of resisting high rotational speed of the turbine.

(Technical issue) This invention suppresses turbulence in the exhaust flow by switching the exhaust passage when turbocharging is turned on, reducing secondary airflow noise and exhaust pressure loss, and making the turbocharger respond faster. It is intended to rotate well.

(Technical means) Therefore, the present invention provides an exhaust passage connecting the inlet and outlet of the muffler body formed by extruded aluminum, and provides a valve in the passage that is switched by the compressor pressure of the turbocharger to reduce the speed at low rotation speeds when the turbocharger is off. In the area, the exhaust gas is guided to the exit via a resonant silencing element including a U-turn expansion chamber.
When turbocharging is on, in the high rotation range, the valve is switched to direct the exhaust gas directly to the multi-hole resonance chamber without passing through the U-turn expansion chamber.

(Effect of technical means) First, in the low rotation range when the turbocharger is off, the engine exhaust gas does not flow to the turbine because the wastegate valve is open, but instead reaches the inlet of the muffler, where it enters the resonance chamber containing the U-turn expansion chamber. It is led to the exhaust outlet via a molded silencing element. On the other hand, when the turbocharger is on and the engine is in a high rotation range, positive pressure air flows into the engine from the compressor and flows into the actuator.The actuator operates to open the valve in the exhaust passage, and the exhaust gas that has turned the turbocharger's turbine is released. Pass through the exhaust passage from the muffler inlet,
It is guided directly to the multi-hole resonance chamber without passing through the U-turn type expansion chamber.

(Special Effects Achieved by the Present Invention) As explained above, in the present invention, in the low rotation range, the exhaust gas is guided to the outlet through the resonant silencing element including the U-turn type expansion chamber. The fundamental wave component of pulsation in the low rotation range can be removed. In addition, in the medium and high rotation range, the exhaust gas is guided directly to the porous resonance chamber without passing through the U-turn expansion chamber.
It is possible to reduce noise and exhaust pressure in the middle and high rotation ranges, and also to increase the rotational speed of the turbocharger and improve its responsiveness. Therefore, horsepower increases. Furthermore, since the muffler body of this invention is formed using extruded aluminum material, there are very few welding points compared to conventional ordinary mufflers, and therefore there is less damage such as gas leakage, and it is highly reliable. Moreover, it has effects such as high rigidity and good heat dissipation.

(Example) An example of the present invention will be described below with reference to the drawings. FIGS. 1 and 2 show an example of the present invention,
Reference numeral 1 designates an air cleaner, in which an air flow meter 2 is disposed adjacently on the downstream side, and a compressor 4 of a turbocharger is provided via a passage 3. 5
is a turbine that rotates together with a compressor 4, and air flowing in from the air cleaner 1 is compressed by the compressor 4 and sent to a passage 7 leading to a throttle valve 6 as shown by the arrow.

A surge tank 8 is connected to an engine combustion chamber 10 via an intake passage 9. Exhaust gas from the combustion chamber 10 passes through passages 11 and 12 to the turbine 5.
sent to. Reference numeral 13 denotes an exhaust passage, which branches off from the passage 11 and is connected to a passage 14 downstream of the turbine 5. At the entrance of the exhaust passage 13, a waste gate valve 17 is provided which closes via an actuator 16 when positive pressure flows from the passage 7 into a passage 15 branched from the passage 7.

Reference numeral 18 denotes a muffler body, which includes a first molded member 19 and a second molded member 20 made of extruded aluminum.
The two are fixed together by welding 21. 22 is a side plate, and 23 is a partition plate, which are also fixed to the first and second molded members by welding 21. The first molded member 19 has an inlet 24 communicating with the passage 14, and the inlet 24
A passageway 25 extends through the second molded member 20 and extends to the side plate 22 at its tip. Further, an exhaust passage 28 connecting the chamber 27 formed by the partition plate 23 and the side plate 26 and the inlet 24 is integrally provided.

A valve 2 is provided in the exhaust passage 28 to open and close the passage.
9 is installed, and the valve 29 is pivotally connected to a rod 32 of an actuator 31 via a link 30. The rod 32 is connected to a diaphragm 34 which is pushed in the direction of closing the valve 29 by a spring 33, and positive pressure is introduced into a chamber 35 on the opposite side of the diaphragm 34 through a passage 36 communicating with the passage 15. Then, the rod 32 is pushed in the direction of opening the valve 29 against the force of the spring 33.

As shown in FIG. 2, the second molded member 20 has a substantially elliptical outer shell and an upper and lower chamber partition wall 37, and an upper chamber partitioned by the partition wall 37 into two chambers 38, 39.
There is a partition 40 that separates the passage 25 into two parts, and within the partition 40 there are provided the passage 25 and a passage 42 above which makes a U turn and passes through the partition plate 23 to reach the chamber 41. The chamber 38 is an expansion chamber and the chamber 39 is a resonance chamber. Further, the passage 25 is connected to the expansion chamber 3 through a notch 43 provided on the side plate 22 side of the partition 40.
8, and the expansion chamber 38 communicates with the passage 42 through a notch 44 provided in the upper partition 40. Furthermore, the expansion chamber 38 and the resonance chamber 39 are in communication via a passage 45.

Reference numeral 46 is a porous pipe, which serves as an exhaust passage 2 facing the chamber 27.
It is supported and fixed by the partition plate 23 and the side plate 22 so that the enlarged part 48 of the inlet is located in the chamber 27 at an appropriate distance from the outlet 47 of the partition wall 37.
The upper surface is held down by a rib 49 provided on the second molded member 20, and is supported by ribs 50, 50 that project obliquely upward from both inner surfaces of the second molded member 20, so that it is fixed so as not to vibrate. Further, the perforated tube 46 is provided with a large number of holes 51 on its circumferential surface, and communicates with the resonance chamber 52 below the partition wall 37 via the holes 51 .
53 is an outlet of the muffler 18.

Next, to explain the operation, in the low rotation range (idling to 2000 rpm), the turbine 5 does not rotate, the waste gate valve 17 is opened, and the exhaust gas from the combustion chamber 10 passes through the exhaust passage 13 and the passage 14 to the muffler body 18. It flows into the inlet 24. At this time, negative pressure flows into the passage 36, the actuator 31 does not operate, and the valve 29 is closed, so the inlet 2
The exhaust gas from 4 enters the expansion chamber 38 through the passage 25 and the notch 43, and is further divided into two parts, one of which is connected to the notch 4.
4. It flows from the passage 42, the chamber 41, and the chamber 27 into the porous pipe 46 via the expanded portion 48. The other exhaust gas separated from the expansion chamber 38 enters the resonance chamber 39 through the passage 45 and attenuates low frequency sounds. On the other hand, the exhaust gas that has flowed into the porous pipe 46 from the expanded portion 48 is divided into two types: one that goes straight to the outlet 53 as it is, and the other that enters the resonance chamber 52 through the hole 51. Attenuate.

Next, when turbocharging is on and in a high rotation range, the actuator 31 is actuated by the positive pressure flowing into the passage 15 to open the valve 29. Therefore, the exhaust gas led to the inlet 24 via the turbine 5 enters the perforated pipe 46 through the exhaust passage 28, the outlet 47, and the expansion part 48, and goes straight to the outlet 53, and the other enters the resonance chamber 52 from the hole 51. Divided into. In addition, rib 5
The notch 54 provided on the side plate 22 of the 0 may be eliminated to create a plurality of independent chambers, and one of the chambers may be filled with sound-absorbing glass wool to absorb harsh sounds in the high-order vibration range. You may also do so. In this case, each chamber can absorb frequency components.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of a muffler for a turbocharged engine showing an embodiment of the present invention, and FIG. 2 is a sectional view taken from A to A in FIG. 1. Explanation of the main parts of the diagram, 4...Compressor, 5
... Turbine, 10 ... Combustion chamber, 15 ... Passage,
17... Waste gate valve, 18... Muffler body, 19... First molded member, 20... Second molded member, 22... Side plate, 23... Partition plate, 24
...Inlet, 25 ... Passage, 28 ... Exhaust passage, 2
9... Valve, 37... Partition wall, 38... Expansion chamber, 39... Resonance chamber, 42... Passage, 43, 44
... Notch, 46 ... Porous pipe, 51 ... Hole, 52
...Resonance chamber, 53...exit.

Claims (1)

[Scope of utility model registration request] An exhaust passage connecting the inlet and outlet of the muffler body formed by extruded aluminum is provided, and a valve that is switched by the compressor pressure of the turbocharger is installed in the passage, and a U-turn type expansion chamber is included in the low rotation range when the turbocharger is off. The exhaust gas is guided to the outlet through the resonance type silencing element, and when the turbocharger is on and in the high rotation range, the valve is switched so that the exhaust gas is guided directly to the porous resonance chamber without passing through the U-turn expansion chamber. A muffler for engines with a characteristic turbocharger.