JP2001317421A - Noise suppressor for supercharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively suppress an emission sound of bypass air when an air bypass valve is opened. SOLUTION: A noise suppressor for a supercharger is designed for the structure where a compressor of a supercharger is disposed in an intake passage of an internal combustion engine, an element chamber for storing a filter element is defined in an air cleaner on the upstream side of the intake passage, an expansion chamber is formed in the element chamber by a division wall, a communicating hole is formed in the division wall to interconnect the expansion chamber and the element chamber, an air bypass passage is arranged with one end connected to an intake passage downstream of the compressor and the other end connected to the expansion chamber in the air cleaner, and an air bypass valve is interposed in the air bypass passage to reflux intake air in the intake passage downstream of the compressor to the expansion chamber when opened in a decelerating operation of the internal combustion engine. The division wall has small-diameter communicating holes directed to the filter element.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silencer for a turbocharger, and more particularly to a silencer for a turbocharger capable of effectively silencing a bypass air discharge sound when an air bypass valve is opened.

[0002]

2. Description of the Related Art An internal combustion engine is provided with a supercharger to improve the combustibility by increasing the amount of air supplied to a combustion chamber.
Some are trying to improve engine output and fuel consumption rate.

FIG. 6 shows an internal combustion engine having such a supercharger. In the figure, 102 is an internal combustion engine, 104 is a combustion chamber, 106 is an intake passage, and 108 is an exhaust passage. The internal combustion engine 102 has an intake passage 1 that starts at an air cleaner 110 at an upstream end and ends at a combustion chamber 104.
06 is provided, and an exhaust passage 108 that starts at the combustion chamber 104 and ends at the outside air is provided. The internal combustion engine 102 has a throttle valve 112 provided in the middle of the intake passage 106 and a catalyst 114 provided in the middle of the exhaust passage 108.

[0005] As shown in FIG. 5, the air cleaner 110 accommodates a filter element 120 in an element chamber 118 in a cleaner case 116, provides an air intake 122 that is open to the outside air, and an air intake that communicates with the intake passage 106. 124 are provided.

[0005] The internal combustion engine 102 is provided with a supercharger 126. The supercharger 126 has a compressor 128 provided in the middle of the intake passage 106 and a turbine 130 provided in the middle of the exhaust passage 108. The supercharger 126 rotates the compressor 128 by the turbine 130 to pump the intake air. Reference numeral 132 denotes an intercooler 132 provided in the intake passage 106 on the downstream side of the compressor 128.

The turbocharger 126 has an exhaust bypass passage 134 communicating the exhaust passages 108 upstream and downstream of the turbine 130, and a waste gate valve 136 for opening and closing the exhaust bypass passage 134. A gate valve 136 is provided in communication with the actuator 138. The actuator 138 opens and closes the waste gate valve 136 to regulate the supercharging pressure so as not to exceed a set value.

The supercharger 126 of the internal combustion engine 102 has an air bypass passage 140 for returning the intake air in the intake passage 106 downstream of the compressor 128 to the air cleaner 110 which is the intake passage 106 upstream of the compressor 128. An air bypass valve 142 that is opened during deceleration operation of the internal combustion engine 102 due to rapid closing of the throttle valve 112 is provided in the middle of 140.

As shown in FIG. 5, the silencer 144 of the supercharger 126 is provided with a cleaner case 1 for the air cleaner 110.
An expansion chamber 148 is formed and provided in the element chamber 118 in the chamber 16 by the partition wall 146, and the communication hole 150 is formed in the partition wall 146.
Is formed and provided. The air bypass passage 140
Is connected at one end to the intake passage 10 downstream of the compressor 128.
6 and the other end thereof is connected to the expansion chamber 148 by a bypass air inlet 152 formed in the cleaner case 116 of the air cleaner 110 on the upstream side of the compressor 128.

[0009] The muffler 144 of the supercharger 126 opens the air bypass valve 142 during the deceleration operation of the internal combustion engine 102 in which the throttle valve 112 is suddenly closed, so that the supercharging pressure in the intake passage 106 downstream of the compressor 128 is reduced. Is returned to the expansion chamber 148 of the air cleaner 110. As a result, the muffler 144 reduces the supercharging pressure in the intake passage 106 on the downstream side of the compressor 128 to the air cleaner 110.
The expansion chamber 148 reduces the surge pressure acting on the compressor 128 while reducing the bypass air discharge noise.

[0010] Such a silencer for a supercharger is disclosed in Japanese Utility Model Publication No. Sho 62-42114 and Japanese Patent Laid-Open No. 6-336958.
Is disclosed in Japanese Unexamined Patent Application Publication No. 2000-205,878.

Japanese Utility Model Publication No. Sho 62-42114 discloses an air cleaner in which a surge tank is provided in a cleaner case, and a blow-off valve for controlling a supercharging pressure is provided in the surge tank.

Japanese Patent Application Laid-Open No. 6-336958 discloses an air cleaner provided with an expansion chamber in a cleaner chamber,
The downstream side of the turbocharger communicates with the expansion chamber by a communication hose, and an air bypass valve is interposed in the communication hose.

[0013]

Meanwhile, the conventional silencer 144 of the supercharger 126 shown in FIGS. 5 and 6 has a partition wall 1 in the cleaner case 116 of the air cleaner 110.
The air bypass passage 1 is provided in the expansion chamber 148 formed by
By reducing the supercharging pressure of the intake passage 106 downstream of the compressor 128 by the opening operation of the air bypass valve 142 to the expansion chamber 148, the bypass air discharge noise is reduced.

However, the supercharging pressure of the intake passage 106 downstream of the compressor 128 which is recirculated to the expansion chamber 148 is rapidly increased by the deceleration operation of the internal combustion engine 102.
There is a disadvantage that the pressure cannot be reduced sufficiently only by opening and diffusing to the single expansion chamber 148, and the bypass air discharge sound cannot be effectively silenced.

[0015]

SUMMARY OF THE INVENTION Accordingly, in order to eliminate the above-mentioned disadvantages, the present invention provides a compressor for a supercharger in an intake passage of an internal combustion engine, and a filter element in an air cleaner upstream of the intake passage. And an expansion chamber is formed in the element chamber by a partition wall, and a communication hole is formed in the partition wall to communicate the expansion chamber and the element chamber. An air bypass passage is provided that communicates one end to the passage and the other end to an expansion chamber in the air cleaner, and is opened during a deceleration operation of the internal combustion engine in the middle of the air bypass passage so as to open the downstream side of the compressor. In a silencer for a turbocharger provided with an air bypass valve for returning intake air from an intake passage to the expansion chamber, a filter element is provided on the partition wall. It is directed to a cement characterized by providing form a small diameter communication hole.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
An expansion chamber through which an air bypass passage is communicated is formed by a partition wall in the element chamber of the air cleaner, and a small-diameter communication hole is formed in the partition wall so as to be directed to the filter element. The supercharging pressure on the downstream side of the compressor, which has suddenly increased due to the operation, is first introduced into the expansion chamber to reduce the pressure, then passed through a small-diameter communication hole to further reduce the pressure, and then contacted with the filter element to absorb sound. Thus, the bypass air discharge sound can be muted through a three-step process.

[0017]

An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show a first embodiment of the present invention. In FIG. 2, 2 is an internal combustion engine, 4 is a cylinder block, 6 is a cylinder head, 8 is a head cover, 10 is a piston, 12 is a combustion chamber, 14 is an intake port, 16 is an exhaust port, 18 is an intake valve, and 20 is exhaust. valve,
22 is an intake passage, and 24 is an exhaust passage.

The internal combustion engine 2 starts at an air cleaner 26 at an upstream end and enters the combustion chamber 12 through a first intake pipe 28, a second intake pipe 30, a throttle body 32, and an intake manifold 34 via an intake port 14. An intake passage 22 is provided at the end, and an exhaust passage 24 is provided at the beginning of the combustion chamber 12 and terminates at the outside air through an exhaust port 36 via an exhaust manifold 36, a first exhaust pipe 38 and a second exhaust pipe 40. A throttle valve 42 is provided in the intake passage 22 of the throttle body 32. A catalyst 44 is provided in the exhaust passage 24 of the second exhaust pipe 40.

As shown in FIG. 1, the air cleaner 26 is provided in an element chamber 48 in a cleaner case 46 to accommodate a filter element 50 which is formed by a nonwoven fabric or the like into a substantially corrugated cross section. The cleaner case 46 includes a first case 46-1 and a second case 46.
The first case portion 46-1 is provided with an air inlet 52 that opens to the outside air, and the second case portion 46-2 is provided with an air outlet 54 that communicates with the intake passage 22.

The air cleaner 26 is provided on the first case 46-1 side of the filter element 50 by forming an outside air side element chamber 48-1 which is opened to the outside air through an air intake 52. The second case 46 of the filter element 50 is provided. An intake side element chamber 48-2 communicating with the intake passage 22 through the air outlet 54 is formed and provided on the −2 side.

This internal combustion engine 2 is provided with a supercharger 56. The supercharger 56 has a compressor 58 provided in the intake passage 22 and a turbine 60 provided in the exhaust passage 24. The supercharger 56 connects the compressor 58 to the turbine 6
The intake air is pumped by rotating at 0. The supercharging pressure of the pressure-fed intake air is cooled by an intercooler 62 provided in the intake passage 22 of the second intake pipe 30 on the downstream side of the compressor 58, adjusted by the throttle valve 42, and supplied to the combustion chamber 12 of the internal combustion engine 2. Is done.

The turbocharger 56 is provided with an exhaust bypass passage 64 communicating the exhaust passages 24 upstream and downstream of the turbine 60, and a waste gate valve 66 for opening and closing the exhaust bypass passage 64 is provided. A gate valve 66 is provided in communication with the actuator 68. The actuator 68 is operated by the supercharging pressure of the intake passage 22 on the downstream side of the compressor 58, and opens and closes the waste gate valve 66 to regulate the supercharging pressure so as not to exceed a set value.

The supercharger 56 of the internal combustion engine 2 transfers the intake air from the intake passage 22 downstream of the compressor 58 to the compressor 5.
8 An air bypass passage 70 is provided to recirculate the air to the air cleaner 26, which is the intake passage 22 on the upstream side. An air bypass valve 72 is opened in the middle of the air bypass passage 70 when the internal combustion engine 2 is decelerated by the rapid closing of the throttle valve 42. Is provided. The air bypass valve 72 is opened and closed by a differential pressure on the upstream and downstream sides of the compressor 58 and an electric actuator (not shown).

The muffler 74 of the supercharger 56 is provided in the element chamber 48 in the cleaner case 46 of the air cleaner 26.
An expansion chamber 78 is formed by a partition wall 76.
The partition wall 76 includes an opposing wall portion 76-1 that is in close proximity to the filter element 50, and a separating wall portion 7 that is substantially perpendicular to the opposing wall portion 76-1 and that is erected from the filter element 50.
6-2. The expansion chamber 78 includes an opposing wall 76-1.
And the separation wall 76-2 and the partition wall 76-2.
It is formed near the filter element 50 in the intake-side element chamber 48-2 of the case 46-2.

The second case section 46 in which the extension chamber 78 is formed
2, a bypass air inlet 80 is provided. The bypass air inlet 80 is provided with one end communicating with the other end of the air bypass passage 70 that communicates with the intake passage 22 downstream of the compressor 58. The partition wall 76 that forms the expansion chamber 78 is provided with a small-diameter communication hole 82 that is directed toward the filter element 50. In this embodiment, a small diameter and a plurality of communication holes 82 are formed in the facing wall portion 76-1 of the partition wall 76, which is opposed to the filter element 50, so as to be directed toward the filter element 50.

Next, the operation will be described.

During operation of the internal combustion engine 2, the compressor 58 of the supercharger 56 provided in the middle of the intake passage 22 is rotated by the turbine 60 provided in the middle of the exhaust passage 24 to feed the intake air. The pumped air is supplied to the throttle valve 4
The intake air amount is adjusted by the intake air 2 and supplied to the combustion chamber 12 of the internal combustion engine 2.

During the deceleration operation of the internal combustion engine 2, the throttle valve 42 of the intake passage 22 downstream of the compressor 58 is rapidly closed to be fully closed. At this time, the air bypass valve 72 is opened by the deceleration operation of the internal combustion engine 2 due to the rapid closing of the throttle valve 42, and the supercharging pressure of the intake passage 22 downstream of the compressor 58 is expanded by the air bypass passage 70 to expand the inside 26 of the air cleaner. Refluxing to the chamber 78 reduces the surge pressure acting on the compressor 58.

The muffler 74 of the supercharger 56 is provided in the air bypass passage 7 in the element chamber 48 of the air cleaner 26.
0 is formed by the partition wall 76 to communicate with 0,
A plurality of small-diameter and plurality of communication holes 82 are formed so as to be directed toward the filter element 50 in an opposing wall portion 76-1 of the partition wall 76 that opposes the filter element 50.

Thus, the silencer 74 of the supercharger 56
The supercharging pressure on the downstream side of the compressor 58, which has suddenly increased due to the deceleration operation of the internal combustion engine 2, is first introduced into the expansion chamber 78 to reduce the pressure, and then passed through the small-diameter and plural communication holes 82 to further increase the pressure. The filter element 5 is lowered and then bent into a substantially corrugated cross-sectional shape with a nonwoven fabric or the like.
The sound can be absorbed by abutting against zero, so that the bypass air discharge sound can be muted through a three-step process.

For this reason, the silencer 74 of the supercharger 56
Can effectively mute the bypass air discharge sound when the air bypass valve 72 is opened.

FIG. 3 shows a second embodiment. The muffler 74 of the second embodiment is provided with an expansion chamber 78 formed by a partition wall 76 in a second case portion 46-2 of the air cleaner 26, and a plurality of first and second extension walls are provided in the expansion chamber 78. 84-1 and 84-2 are disposed alternately and substantially in parallel and gradually spaced apart from each other so that the distance gradually increases, and the expansion chamber 78 is connected to the narrow first expansion chamber 78-1 on the bypass air inlet 80 side and the second expansion chamber 78-1. Second expansion chamber 78-2 wider than first expansion chamber 78-1 and communication hole 8
It is formed into a maze shape that is divided and bent into a third expansion chamber 78-3 having a maximum width on the two sides.

The muffler 74 of the second embodiment has an expansion chamber 78 formed in the second case 46-2 of the air cleaner 26.
The first to third expansion chambers 78-1 to 78-3 whose width is gradually increased by the plurality of first and second extension walls 84-1 and 84-2.
Is formed into a maze shape, and the supercharging pressure introduced from the bypass air inlet 80 formed in the second case portion 46-2 is gradually increased in the maze shape.
The pressure can be gradually reduced by the expansion chambers 78-1 to 78-3, and the bypass air discharge sound can be more effectively silenced.

FIG. 4 shows a third embodiment. The muffler 74 of the third embodiment is provided with an expansion chamber 78 formed by a partition wall 76 in the second case portion 46-2 of the air cleaner 26, and a plurality of first and second partition walls 8 are provided in the expansion chamber 78.
6-1 and 86-2 are arranged substantially in parallel and at intervals so as to gradually increase the interval, and the expansion chamber 78 is divided into first to third expansion chambers 78-1 to 78-3. 1 ・ Second partition 86-1
・ The first and second through-holes 88-1.8 of small diameter are respectively provided in 86-2.
8-2.

The muffler 74 of the third embodiment has an expansion chamber 78 formed in the second case 46-2 of the air cleaner 26.
Is divided into first to third expansion chambers 78-1 to 78-3 by a plurality of first and second partitions 86-1 and 86-2, and the first and second partitions 86-1 and 86-2 have a small diameter. First and second through holes 8
Due to the formation of 8-1 and 88-2, the supercharging pressure introduced into the first expansion chamber 78-1 from the bypass air inlet 80 formed in the second case portion 46-2 is reduced by the second and third expansion. Room 7
8-2.78-3 and first and second through holes 88-1.88-
2 can sequentially reduce the pressure, and the bypass air discharge sound can be more effectively silenced.

[0037]

As described above, the silencer for a turbocharger according to the present invention has a small-diameter communication directed to a filter element on a partition wall forming an expansion chamber to which an air bypass passage in an element chamber of an air cleaner is communicated. By providing the holes, the supercharging pressure on the downstream side of the compressor, which has been sharply increased by the deceleration operation of the internal combustion engine, is first introduced into the expansion chamber to reduce the pressure, and then passed through the small-diameter communication hole to further increase the pressure. The pressure can be reduced and then abutted against the filter element to absorb the sound, and the bypass air discharge sound can be silenced through a three-step process.

Therefore, the silencer of the turbocharger can effectively muffle the bypass air discharge sound when the air bypass valve is opened.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of an air cleaner showing an embodiment of a supercharger silencer according to the present invention.

FIG. 2 is a schematic configuration diagram of an internal combustion engine including a supercharger.

FIG. 3 is an enlarged sectional view of a main part of an air cleaner according to a second embodiment.

FIG. 4 is an enlarged sectional view of a main part of an air cleaner according to a third embodiment.

FIG. 5 is an enlarged sectional view of an air cleaner showing a conventional example.

FIG. 6 is a schematic configuration diagram of an internal combustion engine provided with a supercharger showing a conventional example.

[Explanation of symbols]

 2 Internal combustion engine 12 Combustion chamber 14 Intake port 16 Exhaust port 22 Intake passage 24 Exhaust passage 26 Air cleaner 42 Throttle valve 46 Cleaner case 48 Element chamber 50 Filter element 56 Supercharger 58 Compressor 60 Turbine 70 Air bypass passage 72 Air bypass valve 74 Noise reduction Device 76 Partition wall 78 Expansion room 82 Communication hole

Claims (2)

[Claims] 1. A compressor of a supercharger is provided in an intake passage of an internal combustion engine, an element chamber for accommodating a filter element is provided in an air cleaner on an upstream side of the intake passage, and an expansion chamber is formed by a partition wall in the element chamber. A communication hole is formed in the partition wall to communicate the expansion chamber and the element chamber, and one end is connected to the intake passage on the downstream side of the compressor, and the other end is connected to the expansion chamber in the air cleaner. A supercharger provided with an air bypass passage communicating with the air bypass passage, and an air bypass valve provided in the middle of the air bypass passage so as to be opened during deceleration operation of the internal combustion engine and to return the intake air in the intake passage downstream of the compressor to the expansion chamber. A silencing device for a machine, wherein a small diameter communication hole is formed in the partition wall so as to be directed to a filter element. Machine silencer. 2. An air chamber, wherein an expansion chamber is formed by a partition wall near a filter element in an element chamber of the air cleaner, and a small diameter and a plurality of communication holes are formed in an opposing wall portion of the partition wall which opposes the filter element. The silencing device for a turbocharger according to claim 1, wherein the silencing device is formed so as to be directed to the filter element.