JPH0596463U - Intake muffler for internal combustion engine - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an intake silencer for an internal combustion engine that reduces pulsation in all frequency regions of the engine and obtains a good silencing effect. [Composition] The intake passage 2 and the exhaust passage 4 of the engine 3 are connected by connecting pipes 10b and 10a, and the connecting pipe 1
An intermediary device 5 is provided in the middle of 0b and 10a, and the intermediary device 5 is provided with a vibrating plate 12 that defines an intake path 2 and an exhaust path 4 therein. It is set so that a pulsation having a cycle in which the phase of the intake pulsation in the intake path 2 is out of phase with 180 degrees and an amplitude substantially the same as the amplitude of the intake pulsation is supplied.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an intake silencer for an internal combustion engine having a function of preventing noise caused by intake pulsation.

[0002]

[Prior Art]

 Generally, an intake system of an internal combustion engine is provided with an air cleaner, and the outside air taken in from an intake pipe is supplied to the carburetor side after being filtered by an element in an air cleaner housing.

By the way, the intake air of the engine causes pulsation of a predetermined cycle and amplitude according to the engine speed, while the housing of the air cleaner is made of a thin metal plate or synthetic resin, which is a kind of resonance. Since a box may be formed, the intake pulsation of the engine may be amplified and loud noise may be generated.

Therefore, conventionally, a muffler is arranged in the middle of the intake pipe, or an expansion chamber is provided in a part of the housing, and the air flow passes through the expansion chamber to cancel the intake pulsation and generate noise. To prevent.

[0005]

[Problems to be solved by the device]

 However, while the frequency of engine intake pulsation varies depending on the number of revolutions, the volume of muffler or expansion chamber and pipe length are constant, so effective muffling is performed in a certain rotational speed region. However, good muffling effects were not always obtained at speeds other than the set speed.

The present invention solves the above problems, and provides an intake silencer for an internal combustion engine that can reduce pulsation in all frequency ranges and obtain a good silencing effect.

[0007]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention connects an intake path and an exhaust path of an internal combustion engine with a connecting pipe, and provides an intermediary device in the middle of the connecting pipe. A vibrating plate that defines a path and an exhaust path is provided. On the exhaust path side of the vibrating plate, the cycle of the intake pulsation in the intake path, the cycle with a phase shift of nearly 180 °, and the amplitude of the intake pulsation It is characterized in that it is set so that pulsations having the same amplitude are supplied.

[0008]

[Action]

 In the mediator structure having the above-described configuration, the diaphragm vibrates with a phase shift of nearly 180 ° with respect to the cycle of the generated pulsation, and the vibration vibrates at substantially the same amplitude, and the vibration and the intake vibration cancel each other, whereby the vibration disappears.

[0009]

【Example】

 FIG. 1 is a block diagram of an intake silencer for an internal combustion engine according to an embodiment of the present invention. In the figure, 1 is an air cleaner, 2 is an intake path, 3 is an engine, 4 is an exhaust path, and 5 is an intermediary device.

In the air cleaner 1, a suction pipe 6 is connected to a housing 7, and an element 8 is housed in the housing 7. The intake passage 2 connects the air cleaner 1 and the carburetor side of the engine 3. The exhaust path 4 discharges exhaust gas from the engine 3 and includes a muffler 9. The mediator 5 is provided with a case 11, one of which is connected to the exhaust passage 4 by a connecting pipe 10a and the other of which is connected to the intake passage 2 by a connecting pipe 10b, and the intake passage 2 is provided substantially in the center of the case 11. A diaphragm-shaped diaphragm 12 that defines the side of the exhaust path 4 and the side of the exhaust path 4 is provided.

In the intake silencer for an internal combustion engine having the above-described structure, the outside air is sucked into the air cleaner 1 from the suction pipe 6 of the air cleaner 1, filtered by the element 8, and passed through the suction path 2 to the carburetor of the engine 3. Supplied to the side. Exhaust gas from the engine 3 is exhausted through the exhaust passage 4 and the muffler 9. At this time, pulsation of a predetermined cycle and amplitude occurs in the intake air in the intake passage 2 in accordance with the engine speed, while exhaust gas in the exhaust path 4 also has a predetermined cycle and amplitude in accordance with the engine speed. Pulsation occurs. The pulsation of the exhaust gas is transmitted to the diaphragm 12 in the mediator 5 through the connecting pipe 10a, and the vibration transmitted to the diaphragm 12 is transmitted from the diaphragm 12 to the suction path 2. The vibration on the exhaust side and the vibration on the intake side cancel each other out through the diaphragm, whereby the vibration disappears. In this case, by appropriately selecting the size of the case 11 of the mediator 5 and the inner diameter of the connecting pipe 10a according to the characteristics of the engine 3, the cycle of the pulsation generated in the intake passage 2 by the mediator 5 is selected. However, the phase is shifted by about 180 ° so that the diaphragm 12 can be vibrated with substantially the same amplitude.

[0012]

[Effect of the device]

 As described in detail with reference to the above embodiments, in the intake silencer for an internal combustion engine according to the present invention, the diaphragm vibrates with substantially the same amplitude by shifting the phase by about 180 ° with respect to the cycle of the generated pulsation, This vibration and intake vibration cancel each other out, so that the vibration is extinguished, so compared to the case where a conventional silencer or expansion chamber is installed, it is more effective even outside the set rotational speed range. You can mute the sound.

Therefore, the present invention is particularly suitable for preventing intake noise of an internal combustion engine of an automobile or the like in which the rotation fluctuation is severe.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an intake silencer for an internal combustion engine according to an embodiment of the present invention.

[Explanation of symbols]

 1 Air Cleaner 2 Intake Path 3 Engine 4 Exhaust Path 5 Mediator 12 Vibration Plate 10a, 10b Connection Pipe

Claims (1)

[Scope of utility model registration request] 1. An intake passage and an exhaust passage of an internal combustion engine are connected by a connecting pipe, and an intermediary device is provided in the middle of the connecting pipe, and the intermediary device defines the intake air passage and the exhaust air passage therein. A vibration plate is provided, and on the exhaust path side of the vibration plate, there is a pulsation having a cycle in which the phase is shifted by 180 ° from the cycle of the intake pulsation in the intake path and an amplitude substantially the same as the amplitude of the intake pulsation. An intake silencer for an internal combustion engine, characterized in that it is set to be supplied.