JPH0640319U - Engine intake / exhaust system resonator device - Google Patents

Abstract

(57) [Abstract] [Purpose] In a Holmhertz type resonator device provided on at least one side of an intake passage or an exhaust passage of an engine, a good sound absorbing effect and an inertia supercharging effect are obtained in a wide range of engine rotation by a simple structure. To get A plurality of resonator chambers r1 to r3 are connected to an intake pipe 10 (or an exhaust pipe) via communication pipes p1 to p3, respectively, and the sound absorption frequencies of these resonators RI to R3 are closer to the engine, the higher the engine rotation speed. In the region, the connection positions of the communication pipes P1 to P3 are adjusted so that the intake pipe 10 (or the exhaust pipe) including the manifold 20 from each of the resonators R1 to R3 to the engine is tuned substantially in phase with the inertial supercharging frequency in antiphase. And set the dimensions of each part.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention relates to an engine intake / exhaust system resonator device.

[0002]

[Prior art]

 In the engine intake system, a Helmholtz-type resonator (resonator) is often installed in the intake passage in order to absorb muffled sound in the intake passage and to supercharge the intake air (Saikaihei 3-89975). Official Gazette, Japanese Utility Model Laid-Open No. 62-145937, Japanese Utility Model Laid-Open No. 2-100858, Japanese Utility Model Laid-Open No. 63-141870, Japanese Utility Model Laid-Open No. 58-193017, Japanese Utility Model Laid-Open No. 58-193016, Japanese Utility Model Laid-Open No. 58. -103,018).

Among these, there is provided a variable means for adjusting the volume of the resonator chamber so that a good noise reduction effect can be obtained over a wide range according to the engine rotation speed, and a good inertia over a wide range as well. In order to obtain the supercharging effect, there are some which are provided with a variable means for adjusting the substantial length of the resonance passage from the downstream of the resonator to the engine.

[0004]

[Problems to be solved by the device]

 By the way, none of these conventional examples produce a good muffling effect and a supercharged inertial effect over a wide range of engine rotation. Therefore, if both effects are to be obtained, the volume varying means of the resonator chamber should be used. However, this means that the structure for changing the length of the resonance passage is also used. However, this makes the structure considerably complicated, and even if it could be realized, many additional parts would be required, which would be disadvantageous in terms of cost. .

In order to solve such a problem, the present invention provides a resonator device that produces a good sound absorbing effect and an inertia supercharging effect in a wide range of engine rotation by a simple configuration that does not use a variable means. To aim.

[0006]

[Means for Solving the Problems]

 Therefore, this invention is a Holmhertz type resonator device which is provided on at least one side of an intake passage or an exhaust passage of an engine, and connects a plurality of resonator chambers to the intake passage or the exhaust passage through communication pipes. The closer the sound absorption frequency of the resonator is to the engine, the higher the engine rotation range, so that the resonance position of the intake passage or the exhaust passage is approximately the same as the inertial supercharging frequency in antiphase. To set.

[0007]

[Action]

 Each resonator operates in a lower engine rotation range as it gets farther from the engine, and when the sound absorption frequency at the connecting position of the communication pipe almost matches the pulsation frequency of the intake or exhaust, they resonate in opposite phases and mute. Therefore, pulsation does not propagate as noise from the connection position of the communication pipe to the atmosphere side. Similarly, on the engine side from the connection position, inertial supercharging of intake air or exhaust air is effectively performed by the resonance effect of air column vibration. Therefore, these resonators act sequentially in a stepwise manner according to the engine speed, and thus a good muffling effect and supercharging effect can be obtained in a wide operating range.

[0008]

【Example】

 FIG. 1 shows an example of application to an engine intake system, and three resonator chambers r1 to r3 are connected to an air cleaner downstream of an intake pipe 10 via communication pipes p1 to p3, respectively. The sound absorption frequencies fn of the resonators RI to R3 are given by the formula 1, and the inertia supercharging frequency Fn downstream of the communication pipes p1 to p3 are given by the formula 1, respectively, and the sound absorption frequencies fn of the resonators R1 to R3 are given. Is closer to the engine in a higher engine rotation range, and is tuned substantially in antiphase with the inertial supercharging frequency Fn of the intake pipe 10 including the manifold 20 from each of the resonators R1 to R3 to the engine, that is, fn≈ Fn (n = 1 to 3 corresponding to the resonators R1 to R3 in this case), the volume vn of the resonators r1 to r3, the total length ln of the communication pipes p1 to p3, and the disconnection of the communication pipes p1 to p3. The area an, the volume V of the intake manifold 20, the cross-sectional area A of the intake pipe 21, and the connection position Ln (represented by the length of the intake pipe) of the communication pipes p1 to p3 are set. It should be noted that "c" in the equation (1) represents the sound velocity c in the intake pipe 10.

[0009]

[Equation 1]

With such a configuration, each of the resonators R1 to R3 operates in a higher engine rotation region as it is closer to the engine, and the sound absorption frequency fn is the pulsation of the intake air at the connection position Ln of the communication pipes r1 to r3. When the frequency coincides with the frequency Fn, it resonates in opposite phases to each other to muffle the sound, so that the pulsation does not propagate as noise from the connection position Ln of the communication pipes r1 to r3 to the atmosphere side. Further, similarly, from the connection position Ln, inertial supercharging of intake air is effectively performed by the resonance action of air column vibration.

Therefore, these resonators R1 to R3 are sequentially stepwise according to the engine speed, for example, the resonator R3 in the low speed range, the resonator R2 in the medium speed range, and the resonator R1 in the high speed range as described above. Since it is tuned to, good muffling effect and supercharging effect can be obtained in a wide driving range. It should be noted that these effects are particularly remarkable when the engine has four cylinders or less. The dashed line S, s in FIG. 1 represents the node of the sound pressure mode in tune with the resonator R1.

FIG. 3 shows a structure in which a plurality of resonators R1 to R3 and R1 to R4 are arranged on both sides of the intake and exhaust systems, respectively, in order to obtain the same muffling effect and inertia supercharging effect in the engine exhaust system as in the intake system. In the embodiment, the exhaust system resonators R1 to R4 are also similar to the intake system resonators R1 to R3. The closer to the engine, the higher the engine rotation range, and the sound absorption frequency fn and the inertia supercharging frequency Fn are in opposite phases. The volumes vn of the resonator chambers r1 to r4, the total length ln of the communication pipes p1 to p4, the cross-sectional area an of the communication pipes p1 to p4, the volume V of the exhaust manifold 30, and the cross-sectional area A of the exhaust pipe 31 so that they are tuned substantially in agreement. And the connection position Ln of the communication pipes p1 to p4 is set.

In this case, since the exhaust system needs to reduce noise in a wider engine rotation range than the intake system, one more resonator is attached than the intake system. 50 is an air cleaner and 60 is a muffler.

[0014]

[Effect of device]

 In summary, according to the present invention, in the Holmhertz type resonator device provided on at least one side of the intake passage or the exhaust passage of the engine, a plurality of resonator chambers are respectively connected to the intake passage or the exhaust passage via the communication pipes. At the same time, the closer the sound absorption frequency of these resonators to the engine, the higher the engine speed region, and the connection position of each communicating pipe so that they are tuned approximately in phase with the inertial supercharging frequency of the intake passage or exhaust passage in antiphase. Since the dimensions of each part are set, it is possible to obtain good sound absorbing effect and inertia supercharging effect in a wide range of engine rotation with a simple structure.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a configuration diagram showing another embodiment.

[Explanation of Codes] R1 to R3, R1 to R4 Resonator r1 to r3, r1 to r4 Resonator chamber p1 to p3, p1 to p4 Communication pipe 10 Intake pipe 20 Intake manifold 30 Exhaust pipe 40 Exhaust manifold vn Resonator chamber volume ln Communication Total length of pipe an Cross-sectional area of communication pipe V Volume of intake manifold or exhaust manifold A Cross-sectional area of intake pipe or exhaust pipe Ln Connection position of communication pipe expressed by length of intake pipe or exhaust pipe

Claims (1)

[Scope of utility model registration request] 1. A Holmhertz type resonator device provided on at least one side of an intake passage or an exhaust passage of an engine, wherein a plurality of resonator chambers are respectively connected to the intake passage or the exhaust passage through communication pipes, and sound absorption of these resonators is achieved. The closer to the engine the frequency is, the higher the engine rotation range is.In the engine rotation range, the connection position of each communicating pipe and the size of each part are set so that they are tuned in almost the opposite phase with the inertial supercharging frequency of the intake passage or exhaust passage. A characteristic engine intake / exhaust system resonator device.