JP2663151B2 - Air intake silencer for ship propulsion - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an intake muffler for a marine propulsion device such as an outboard motor or an inboard / outboard motor.

2. Description of the Related Art An engine of a marine propulsion device includes an intake air volume control valve (throttle valve) in an intake passage of a carburetor or the like connected to a combustion chamber of the engine, and an intake silence box communicating with an intake inlet of the intake passage. It is configured to take in combustion air from an intake intake of the intake silence box.

By the way, the above-mentioned intake muffling box performs an expansion / contraction type or resonance chamber type muffling effect on an intake sound (air column resonance sound) generated in an intake passage of a carburetor or the like. FIG. 3 is a diagram of an expansion / contraction type noise reduction model. As the expansion chamber volume V is larger than the opening area S, a higher noise reduction effect can be secured. FIG. 4 is a diagram of a noise reduction model of a resonance chamber type. As the resonance chamber volume V is larger than the opening area S, a higher noise reduction effect can be secured.

[Problems to be Solved by the Invention] However, in the above-mentioned intake silencer, there is a difficulty in securing a large volume of the silencer due to downsizing around the engine. This means that the volume V of the sound absorbing chamber corresponding to the volume V of the expansion chamber and the volume V of the resonance chamber is made larger than the area S of the intake port corresponding to the opening area S in FIGS. Means that it is difficult. Therefore, it is difficult to obtain a high noise reduction effect.

In the above-mentioned intake silence box, the area S
It is necessary to provide an area large enough to secure a necessary amount of air during high-load operation of the engine. Therefore, reducing the area S of the intake port for improving the noise reduction effect has a limit in terms of securing the output performance of the engine.

SUMMARY OF THE INVENTION It is an object of the present invention to reduce intake noise as reliably as possible without reducing the size of the engine and the output performance of the engine.

Means for Solving the Problems According to the present invention, an on-off valve is provided on a combustion chamber side of an intake passage connected to a combustion chamber of an engine, and an intake air amount adjusting valve is provided on an intake passage upstream of the on-off valve. In a marine propulsion device provided with an intake chamber communicating with the intake passage upstream of an amount control valve and configured to take in air from an intake intake of the intake chamber, an intake air is provided near the intake intake in the intake chamber. An opening control valve for controlling the opening area of the intake port to be large or small in accordance with the size of the control air amount of the flow control valve is provided.

[Operation] In the marine propulsion device of the present invention, combustion air taken from an intake port provided in an intake chamber such as an engine cover cowling or an intake silencer is introduced into an intake passage such as a carburetor. The air is supplied to the combustion chamber of the engine via an intake air amount adjusting valve such as a throttle valve provided in the intake passage.

Here, the passage area S of the intake passage in the intake chamber needs to be set to a large area because it is necessary to secure a large amount of air during high-load operation.

However, since this intake path does not need to take in a large amount of air on the low load side, the passage area S
There is no adverse effect on output even if aperture is stopped down.

On the other hand, from the viewpoint of intake noise reduction, the passage area S of the intake path is equal to the volume of the noise reduction chamber V shown in FIGS.
The more the aperture is stopped down, the higher the air intake silencing effect can be obtained.

Thus, in the present invention, on the high load side, the opening degree control valve sets the intake path to the open side to expand the passage area. Therefore, at this time, the silencing chamber formed by the intake chamber performs a certain silencing effect while the intake passage of the intake chamber can supply a large amount of air to the combustion chamber without resistance. As a result, the intake noise can be suppressed as reliably as possible without impairing the output performance of the engine.

On the low load side, the opening control valve sets the intake path to the closed side, thereby reducing the passage area. Therefore, at this time, the intake path of the intake chamber is narrowed significantly with respect to the silencing chamber volume V, and the silencing chamber volume V
A high intake air silencing effect can be secured without increasing the size of the air conditioner. Thus, the intake noise can be suppressed as reliably as possible without hindering the compactness around the engine.

 That is, according to the present invention, the following functions and effects are obtained.

The intake sound generated by the compression wave of the intake air generated by the opening and closing of the on-off valve can be silenced in the intake chamber and output to the outside of the intake chamber.

The opening control valve is located near the intake port in the intake chamber, so it can have a small intake opening area at low rotations with a low required intake volume and also prevent the intake noise from leaking out of the intake chamber. .

An opening control valve is provided to control the opening area of the intake port of the intake chamber in accordance with the size of the control air volume of the intake air control valve. It is possible to achieve an appropriate balance between the intake sound and the performance in accordance with the engine speed.

Embodiment FIG. 1 is a cross-sectional view showing an outboard motor engine to which one embodiment of the present invention is applied, FIG. 2 is a cross-sectional view of a main part showing another embodiment, and FIG. FIG. 4 is a schematic diagram showing a resonance room type noise reduction model diagram, and FIG. 5 is a schematic diagram showing an outboard motor to which the present invention is applied.

As shown in FIG. 5, the outboard motor 10 allows the propulsion unit 12 to be mounted on the hull 13 via the mounting bracket 11. Above the propulsion unit 12, a V-type two-cycle engine 15 covered by a cowling (intake chamber) 14
Is installed. The cowling 14 protects the engine 15 from rainwater, seawater, and the like, constitutes an intake chamber of the present invention, and has a first intake intake 14A in a part thereof.

The engine 15 is, as shown in FIG.
It has a combustion chamber 16, a piston 17, a crank chamber 18, and the like, and is provided with a scavenging passage 19 for guiding an air-fuel mixture inside the crank chamber 18 pre-compressed on the back surface of the piston 17 to the combustion chamber 16.

An intake manifold 21 having a reed valve 20, a carburetor 22, and an intake silence box 23 are connected to the crank chamber 18 of the engine 15.

The carburetor 22 is provided with a throttle valve 25 as an intake air amount control valve and a fuel nozzle 26 in an intake passage 24.

The intake silence box 23 constitutes the intake chamber of the present invention,
Along with forming an intake silencing chamber 27 communicating with the intake passage 24 of the carburetor 22, via the left and right second intake intakes 28A and 28B,
The intake silencer 27 communicates with the interior space of the cowling 14.

Thus, in this embodiment, the intake silence box 23
The opening control valves 29A, 29B are provided in the intake inlets 28A, 28B of the air conditioners, and compression springs (control means) 30A, 30B are provided between the back surface of the opening control valves 29A, 29B on the side of the sound deadening chamber and the surface of the sound deadening chamber. Is arranged. The opening control valves 29A, 29B are urged in the closing direction by the spring force of the compression springs 30A, 30B, and urged in the opening direction by the intake negative pressure generated in the intake passage when the engine 15 is operating. That is, the opening degree control valves 29A and 29B operate in conjunction with the load state of the engine 15 due to the balance between the above actions and the springs 30A and 30B on the low load side of the engine 15.
Is set to the closed side by the spring force of the engine 15, and is set to the open side by the intake negative pressure on the high load side of the engine 15.

 Next, the operation of the above embodiment will be described.

In the outboard motor 10, a first intake port 14A provided in the cowling 14 and a second intake port 2 provided in the intake silence box 23 are provided.
Combustion air taken in from 8A and 28B is introduced into an intake passage 24 of a carburetor 22 and passes through a throttle valve 25 provided in the intake passage 24 to a crank chamber 18 of the engine 15 and eventually the combustion chamber 16.
Supplied to

Here, the area S of the intake ports 28A and 28B provided in the intake silence box 23 needs to be set to a large area during a high-load operation because it is necessary to secure a large amount of air.

However, since the intake ports 28A and 28B do not need to take up a large amount of air on the low load side, even if the area S is reduced, there is no adverse effect on the output.

On the other hand, from the viewpoint of intake silencing, the intake intake 28
As the area S of A and 28B is reduced with respect to the silencing chamber volume V shown in FIG. 3, the expansion and contraction type high intake noise silencing effect can be obtained.

Thus, in the above embodiment, on the high load side,
As described above, the opening degree control valves 29A and 29B set the intake ports 28A and 28B to the open side, and expand the opening area.
Therefore, at this time, the intake intake 28 of the intake silence box 23
While the A and 28B can supply a large amount of air to the combustion chamber 16 without resistance, the silencing chamber 27 formed by the intake silencing box 23 performs a certain silencing effect. As a result, the intake noise can be suppressed as reliably as possible without impairing the output performance of the engine 15.

On the low load side, the opening degree control valves 29A and 29B set the intake ports 28A and 28B to the closed side, thereby reducing the opening area. Therefore, at this time, the intake openings 28A, 28B of the intake silence box 23 are greatly narrowed with respect to the silencing chamber volume V, and the expansion / shrinkage type high intake silencing effect is achieved without increasing the silencing chamber volume V. Can be secured. As a result, the intake noise can be suppressed as reliably as possible without hindering the compactness around the engine 15.

FIG. 2 shows another embodiment. This embodiment is different from the embodiment of FIG. 1 in that an opening degree control valve 29B provided in one intake port 28B of an intake silence box 23 and a carburetor That is, the throttle (22) and the throttle valve shaft (25A) are connected by a link (control means) 31. As a result, the intake port 28B is mechanically linked to the change in the opening degree of the throttle valve 25, and is set to the closed side on the low load side of the engine 15 and is set to the open side on the high load side. In this case as well, the expansion / contraction type intake air silencing function as shown in FIG. 3 is made more effective at the time of low-load operation of the engine 15, and as a result, the size around the engine is reduced and the output performance of the engine is hindered. In addition, the intake noise can be suppressed as reliably as possible. At this time, the other intake opening 28A of the muffling box 23 may be provided with the opening control valve 29A that is controlled to open and close as described above.

In addition, in the embodiment of FIG.
In addition to 29B, a gate valve 41 for partitioning the interior of the sound deadening chamber 27 as indicated by a two-dot chain line may be provided. At this time, if the opening control valve 29B is closed, and the middle part of the muffling chamber 27 is partitioned at a certain opening by the partition valve 41, a resonance chamber 42 is formed between the opening control valve 29B and the partition valve 41. it can. Therefore, on the low load side of the engine 15, the opening degree control valve 29B and the gate valve 41 are made independent from each other by a control means such as a spring having a constant strength that balances the intake negative pressure or a link linked to the throttle valve shaft. Or, it is driven in conjunction with the opening degree control valve 29B to gradually close or fully close the intake port 28B, and to partition the middle part of the muffler chamber 27 to the side that gradually shuts off the gate valve 41, The resonance-chamber-type intake air silencing operation as shown in FIG. 4 can be made more effective.

The gate valve 41 may be always fixed at an intermediate opening degree that partially partitions the intermediate portion of the sound deadening chamber 27.

In the implementation of the present invention, as shown in FIG.
An opening control valve 51 is provided at the first intake intake 14A of the cowling 14, and the opening control valve 51 is set to a closed side on a low load side of the engine 15 in conjunction with a load state of the engine 15 to provide a high load. On the side, means for setting to the open side may be provided. In this case, the internal space of the cowling 14 serves as an expansion chamber, so that the expansion / contraction type intake air silencing function as shown in FIG. 3 can be made more effective during low-load operation of the engine 15.

In the present invention, FIG. 1 and FIG.
The respective structural examples shown in the figures can be implemented in combination with each other as appropriate.

FIG. 6 is a sectional view showing an engine for an inboard / outboard engine to which another embodiment of the present invention is applied, and FIG. 7 is a sectional view taken along line VII-VII of FIG.
FIG. 8 is a sectional view taken along a line, and FIG. 8 is an exploded perspective view showing the intake silencer of FIG.

The engine 60 is disposed inside the hull 61 and drives a propulsion unit (not shown) provided outside the hull 61.

The engine 60 comprises a horizontally opposed two-cycle engine as shown in FIG. 6, and includes a crankcase 62, left and right cylinder blocks 63 provided on both sides of the crankcase 62, and cylinder heads provided in each cylinder block 63. 64 constitutes the engine body 60A.

The engine 60 has three cylinders in each of the left and right cylinder banks, and an intake port 66 is provided above a crank chamber 65 narrowed by both cylinder banks. An intake manifold 66 is connected to an intake port 66 of the engine 60 via a reed valve 67. The intake manifold 68 is bent 90 degrees, and connects a carburetor 69 and an intake silence box 70 to a connection port that opens in the lateral direction.

The engine 60 includes, for example, a combustion chamber 71 and a crank chamber 65 of each cylinder at upper and side portions of the left and right cylinder blocks 63, for example, at the third position.
A scavenging passage 72 that communicates with the
An exhaust port 73 of each cylinder is provided below 63.

That is, the engine 60 is provided with a throttle valve 74 in a carburetor 69 interposed in an intake passage connected to the combustion chamber 71, and provided with an intake silence box 70 communicating with the intake passage, and an intake intake 75 of the intake silence box 70. It is configured to take in air from.

Here, the intake silencer 70 is arranged in the order of the first to third three expansion chambers from the side communicating with the carburetor 69 in the intake path.
Equipped with 76A to 76C, and communicates with the diaphragm wall of the adjacent expansion chamber
77A and 77B are formed. As a result, the intake silence box 70
Performs a multistage expansion / contraction type intake muffler including first to third three stages.

Further, the intake muffling box 70 is provided with an opening control valve 78 at a throttle communication port 77A provided between the first expansion chamber 76A and the second expansion chamber 76B, and the opening control valve 78 and the throttle of the carburetor 69 are provided. Valve 74
And are linked by a link 79. 80 is the rotation axis, 81
Is a connecting disk, and 82 is a connecting arm. As a result, the throttle communication port 77A is mechanically linked to the change in the opening of the throttle valve 74, and is set to the closed side on the low load side of the engine 60,
On the high load side, it is set to the open side.

Therefore, even in this embodiment, the multistage expansion / contraction type intake air silencing function is made more effective at the time of low-load operation of the engine 60, and as a result, the size of the engine is reduced and the output performance of the engine is not hindered. The intake noise can be suppressed as reliably as possible.

In this embodiment, since the intake silence box 70 is a multistage expansion / contraction type silence box, silencing can be performed in a wide band from a high frequency to a low frequency.

Further, in this embodiment, since the intake opening 75 of the intake silencing box 70 is open facing the bottom of the ship, the intake intake 75
The radiation of the intake noise emitted from the inside of the ship can be prevented.

Further, in this embodiment, the opening degree adjustment valve may be moved not so as to rotate but so as to cross the throttle communication port, thereby achieving compactness.

Further, in the embodiment of the present invention, a change in the load state such as the rotation speed of the engine is detected, and a control device such as a microcomputer is operated based on the result of the detection to drive the opening control valve (for example, a pulse motor). ) To thereby execute the control operation according to claim 1.

[Effects of the Invention] As described above, according to the present invention, compactness around the engine and output performance of the engine are not hindered.
The intake noise can be suppressed as reliably as possible.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an outboard motor engine to which one embodiment of the present invention is applied, FIG. 2 is a sectional view of a main part showing another embodiment, and FIG. FIG. 4, FIG. 4 is a schematic diagram of a resonance chamber type noise reduction model, FIG. 5 is a schematic diagram showing an outboard motor to which the present invention is applied, and FIG. 6 is an inboard / outboard to which another embodiment of the present invention is applied. 7 is a sectional view taken along the line VII-VII of FIG. 6, and FIG. 8 is an exploded perspective view showing the intake silence box of FIG. 10 ... outboard motor (ship propulsion), 14 ... cowling (intake chamber), 14 A ... first intake inlet, 15 ... engine, 16 ... combustion chamber, 20 ... reed valve (open / close valve) , 23… Intake silence box (intake chamber), 24… Intake passage, 25… Throttle valve (intake amount control valve), 28A, 28B… Second intake intake, 29A, 29B… Opening control valve , 20A, 30B ... compression spring (control means), 31 ... link (control means), 51 ... opening control valve. 60 ... engine, 71 ... combustion chamber, 74 ... throttle valve (intake amount control valve), 77A ... throttle communication port, 78 ... rotation control valve.

Claims (1)

(57) [Claims] An on-off valve is provided on a combustion chamber side of an intake passage connected to a combustion chamber of an engine, and an intake air amount control valve is provided on an intake passage upstream of the on-off valve, and the intake air is provided upstream of the intake air amount control valve. In a marine propulsion device provided with an intake chamber communicating with a passage, and configured to take in air from an intake port of the intake chamber, in the vicinity of the intake port in the intake chamber, An intake muffler for a marine propulsion device, comprising an opening control valve for controlling the opening area of the intake port to be large or small in accordance with the size.