JPS6335815B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an intake noise prevention device when the exhaust brake is activated, which prevents noise from being generated from the intake system when the exhaust brake is activated.

In order to reduce the sound blowing back into the intake air when the exhaust brake is activated, there is a method of disposing an intake cutoff valve in the shape of a throttle valve with a fine hole penetrated through the intake manifold. However, even with such means, it is not possible to sufficiently reduce the blowback noise to the intake air. This is a particularly serious problem in cab-over type vehicles where the air cleaner is located under the driver's seat.

In view of the above-mentioned circumstances, the present invention makes the intake cutoff valve a complete blockage valve, separately provides a branch line connecting the intake manifold and the exhaust manifold, and arranges a branch line cutoff valve in this branch line to prevent the exhaust from flowing. It prevents the generation of intake noise when the brake is applied,
A branch pipe line in which a cut-off valve is arranged between an intake pipe line inward of an intake cut-off valve arranged in an intake manifold and an exhaust pipe line between an exhaust cut-off valve arranged in an exhaust manifold and a silencer. This is an intake noise prevention device when an exhaust brake is operated, characterized in that the intake pipe and the exhaust pipe are connected to each other by the branch cutoff valve, and communication between the intake pipe and the exhaust pipe can be disconnected via the branch cutoff valve.

An embodiment of the device of the present invention will be described with reference to the drawings. An air cleaner 3 and an intake cutoff valve 4 are arranged in an intake manifold 2 of an engine 1, and a silencer 6 and an exhaust cutoff valve 7 are arranged in an exhaust manifold 5. A branch pipe 1 that connects an intake pipe 9 located inward from the intake cutoff valve 4 toward the engine body 8 and an exhaust pipe 10 between the exhaust cutoff valve 7 and the silencer 6.
1, and a branch line cutoff valve 12 is provided in this branch line 11.
Place. the intake cutoff valve 4, the exhaust cutoff valve 7,
The branch passage cutoff valve 12 is, for example, a butterfly-shaped complete blockage valve, the intake cutoff valve 4 is opened and closed by an actuator 13 and an operating lever mechanism 14, and the exhaust cutoff valve 7
are opened and closed by an actuator 15 and an actuation lever mechanism 16, and the branch cutoff valve 12 is formed to be opened and closed by an actuator 17 and an actuation lever mechanism 18.
3 and 15 to close the intake cutoff valve 4 and exhaust cutoff valve 7.
The exhaust cutoff valve 7 is closed simultaneously or with a slight delay, or the exhaust cutoff valve 7 is opened simultaneously or slightly earlier, and the intake cutoff valve 4 and the exhaust cutoff valve 7 are each in a closed state. An actuator 17 is configured to open the branch road cutoff valve 12 and close the branch road cutoff valve 12 when the intake cutoff valve 4 and the exhaust cutoff valve 7 are in the open state.
The operation of the system is regulated. That is, the branch cut-off valve 12 is open when the exhaust brake is activated, and is closed when the non-exhaust brake is activated, so that it can freely interrupt communication between the intake pipe 9 and the exhaust pipe 10.

The actuators 13, 15, and 17 are connected to the same electric circuit, which includes a power source 19, an exhaust brake switch 20, an accelerator switch 21 that closes when the accelerator pedal (not shown) is not depressed. A clutch switch 22 that closes when a clutch pedal (not shown) is not depressed, and a neutral switch 23 that closes when a transmission (not shown) is engaged (not in a neutral state).
is provided. In the figure, 24 is a cylinder, 25 is a piston, 26 is an intake valve, and 27 is an exhaust valve.

Since the present device is constructed as described above, the exhaust brake switch 20, the accelerator switch 21, the clutch switch 22, and the neutral switch 23
When all of the actuators 13, 15,
17 is activated, the intake manifold 2 is closed by the intake cutoff valve 4, the exhaust manifold 5 is closed by the exhaust cutoff valve 7, and the branch line cutoff valve 12 is opened to bring the branch line 11 into communication.

In this situation, the intake air is blocked by the silencer 6.
The air flows from the exhaust manifold 5 through the branch pipe 11 in front of the exhaust cutoff valve 7 and into the cylinder 24 through the intake pipe 9 connected to one end of the branch pipe 11. The sound is muted. Further, since the passage to the air cleaner 3 is closed by the intake air cutoff valve 4, no blowback noise to the intake air in the air cleaner 3 is generated.

Furthermore, in order to create an exhaust brake state, when the air in the cylinder 24 is compressed by the piston 25, the exhaust valve 27 of the cylinder 24 is opened, and the compressed air is passed through the exhaust hole to which the exhaust valve 27 is attached. During the exhaust stroke, air is compressed into the exhaust pipe 10 by the exhaust cutoff valve 7, which flows into the exhaust pipe 10 and closes the exhaust pipe 10, causing the engine to act as a compressor and perform braking.

On the other hand, the compressed air that once entered the exhaust pipe 10 is returned to the cylinder 24 from the exhaust hole and blown back to the intake pipe 9 through the intake hole, but the intake pipe 9 is blocked by the intake cutoff valve 4. Therefore, the compressed air does not return to the air cleaner 3, but instead flows from the branch pipe 11 connected to the intake pipe 9 side to the exhaust pipe 10.
It passes through the silencer 6 and is exhausted from the exhaust manifold 5 to the outside. Therefore, all the noise that is about to be generated will be muffled by the silencer 6.

In this case, if any one of the exhaust brake switch 20, accelerator switch 21, clutch switch 22, and neutral switch 23 is open, the intake cutoff valve 4 opens the intake manifold 2, and the exhaust cutoff valve 7 opens the exhaust The manifold 5 is opened, and the branch line cutoff valve 12 closes the branch line 11.

The present invention connects the inside of the intake pipe inward of the intake cutoff valve disposed in the intake manifold and the inside of the exhaust pipe between the exhaust cutoff valve disposed in the exhaust manifold and the silencer via a branch line by a branch line cutoff valve. Since the communication can be cut off freely, the shutoff valve in the intake pipe is closed only when the exhaust brake is activated, and air is introduced into the cylinder via the silencer through a branch pipe, the blowback noise to the intake air is also muffled by the silencer. This results in effects such as significantly reducing noise in the intake system.

[Brief explanation of drawings]

The drawing is an explanatory view of the main parts of the device of the present invention. 2...Intake manifold, 4...Intake cutoff valve, 5
...Exhaust manifold, 6...Silencer, 7...
Exhaust cutoff valve, 9... Intake pipe line, 10... Exhaust pipe line, 11... Branch pipe line, 12... Branch line cutoff valve.

Claims (1)

[Claims] 1 A branch pipe formed by installing a branch cutoff valve between the intake pipe line inward of the intake cutoff valve arranged in the intake manifold and the exhaust pipe line between the exhaust cutoff valve arranged in the exhaust manifold and the silencer. 1. An intake noise prevention device when an exhaust brake is operated, characterized in that the intake pipe and the exhaust pipe are connected to each other by a branch line cutoff valve, and communication between the intake pipe and the exhaust pipe can be cut off via the branch cutoff valve.