JPH0219643A - Intake noise eliminator for automobile internal combustion engine - Google Patents

Abstract

PURPOSE:To secure such a resonance frequency variable, automobile internal combustion engine intake noise eliminator that is excellent in storage properties by controlling the pipeline length of an interconnecting pipe part extending to the inside of a resonance chamber from an intake pipe part. CONSTITUTION:An intake noise eliminator is provided with an intake pipe part 1, an outer cylinder part 2 constituting a resonance chamber 20 inside, a pipeline length variable interconnecting part 3 whose one end is connected to the intake pipe part 1 while the other end constitutes an opening end in the resonance chamber 20, adjoining to the intake pipe part 1 and extending in the same direction as this intake pipe part 1. A downstream pipe 11 of the intake pipe part 1 is interconnected to an upstream pipe 13 via a bellows 16, a midstream pipe 12 and another bellows 15. A pipeline length control means 4 consists of a gear 42 connected to a turning shaft of a speed reducing motor and a rack part 41 tightly installed on an outer circumferential surface of the midstream pipe 12 so as to be engaged with this gear 42.

Description

[Detailed Description of the Invention] [Industrial Application Field 1] The present invention is directed to internal combustion e! Relating to the intake fHt'l tone generator of lII.

[Prior Art 1] Japanese Utility Model Application Publication No. 61-110818 discloses an intake noise muffler (hereinafter also simply referred to as a resonator) for an internal combustion engine for an automobile.

This resonator includes an intake pipe section arranged to constitute a part of an intake pipe system of an internal combustion engine for an automobile, and a housing that forms a resonant chamber inside the intake pipe section. , one end is connected to the intake pipe part, and the other end constitutes an open end in the resonance chamber, and the pipe length is variable. 1 means for controlling the pipe length.

[Problems to be Solved by the Invention] However, in the conventional resonator described above, the communicating pipe section extends perpendicularly from the intake pipe, and furthermore, the pipe length III 811 means extends from the tip of the communicating pipe section in the same direction as the communicating pipe section. Since the actuator is elongated, there is a drawback that the resonator becomes larger.

However, in recent years, engine rooms of automatic vehicles have become increasingly compact, making it difficult to arrange such a large resonator in the engine room.

The present invention has been made in view of these problems, and it is an object of the present invention to provide an intake noise muffler for an internal combustion engine for an automobile, which is easy to store and has a variable resonant frequency.

[Means for Solving the Problems] The intake aW4 sound device for an internal combustion engine for an automobile according to the present invention includes an intake pipe section disposed to constitute a part of an intake pipe system of the internal combustion engine, and an intake pipe. an outer cylindrical part that surrounds the outer cylinder part and forms a resonance chamber therein; one end is connected to the intake pipe part, the other end forms an open end within the resonance chamber, and is adjacent to the intake pipe part. It is characterized by comprising a communicating pipe section whose length is variable and extending in the same direction as the intake pipe section, and pipe length iJI 111 means for adjusting the pipe length of the communicating pipe section.

The intake noise muffler of the present invention uses a type in which the resonant frequency is made variable by changing the length of the communicating pipe section extending from the intake pipe section into the resonance chamber.

The outer cylinder part only needs to surround a part of the intake pipe part, and the pipe length of the communication pipe part is the pipe length from the communication part between the intake pipe part and the communication pipe part to the open end of the communication pipe. It means.

[Function] In the intake noise muffler of the present invention, one end of the communication pipe section with variable pipe length is connected to the intake pipe section, and extends adjacent to the intake pipe section in the same direction as the intake pipe section.

The pipe length control means controls the pipe length of the communication pipe section extending in the longitudinal direction of the intake pipe section to adjust its resonance frequency.

As a result, the diameter of the outer cylindrical portion surrounding the intake pipe portion and the communication pipe portion can be significantly reduced compared to the conventional case, and the volume of the resonator can be reduced.

[Example] Example 1 An example of the intake noise muffler for an automobile internal combustion engine of the present invention is as follows.
Shown in FIGS. 1 and 2.

This intake noise muffler includes an intake pipe section 1 that forms part of an intake pipe system of an internal combustion engine, and an outer cylinder section that surrounds a part of the intake pipe section 1 and forms a resonance chamber 20 inside. 2, one end is connected to the intake pipe section 1, and the other end constitutes an open end within the resonance chamber 20, and extends adjacent to the intake pipe section 1 in the same direction as the intake pipe section 1. +ti4 variable length communication pipe section 3 and pipe length that increases the pipe length of communication pipe section 3 to 11111II
111 means 4.

The intake pipe portions 1 are arranged in a row in the longitudinal direction at predetermined intervals.
IJed downstream pipe 11, midstream pipe 12, and upstream pipe 1 of the same diameter
3, a bellows 15 connecting the opposing ends of the midstream pipe 12 and the upstream pipe 13, and one end of the downstream pipe 11 and the midstream! !
A bellows 16 connects the other end of the bellows 12 to the other end of the bellows 12. The other end of the upstream pipe 13 is an outside air (combustion air) inlet (
(not shown), and downstream t! The other end of 111 is connected to an inlet of an air cleaner (not shown). Therefore, the downstream pipe 11 includes the bellows 16, the midstream pipe 12 and the base [1].
- communicates with the upstream pipe 13 via the tube 15.

As shown in the sectional view of FIG. 2, the outer cylinder part 2 has a cylindrical shape with bottoms at both ends, and has a closed-mouth barrel shape that accommodates a part of the intake pipe part 1, the communication pipe part 3, and the pipe length control means 4. A resonance chamber 20 is formed. Downstream of intake pipe section 1! ! 11 passes through the center of one circular end surface of the outer cylinder section 2, and the upstream pipe 13 of the intake pipe section 1 passes through the center of the other circular end surface of the outer cylinder section 2.

The communication tube section 3 has a thin tube-shaped root section 31 that is disposed integrally with the downstream tube 11 inside the resonance chamber 20 and has one end communicating with the downstream tube 11, and a root section 31 that is integrally disposed with the midstream tube 12 and has one end that communicates with the downstream tube 11. It is comprised of a thin tube-shaped tip 32 that opens into the resonance chamber 20, and a bellows 33 that connects the other end of the root 31 and the other end of the tip 32 facing thereto. Therefore, the intake pipe portion 1 communicates with the resonance chamber 20 via the root portion 31, the bellows 33, and the tip portion 32. Note that the bellows 33 and the bellows 16 are each integrally molded.

The pipe length control means 4 includes a deceleration motor 43 installed on the inner peripheral surface of the outer cylinder part 2, a gear 42 connected to the rotating shaft of the deceleration motor 43, and a J: sea urchin midstream pipe 12 that meshes with the gear 42. The rack part 41 is fixed to the outer peripheral surface of the rack part 41.

The operation of this resonator will be explained.

For example, the engine speed is detected by a tachometer or a high-speed sensor installed in the crankshaft, and when the detected engine speed is low, the deceleration motor 43 is driven and the rack section 41 and midstream pipe are 12 and the tip portion 32 in the X direction shown in FIG. 1 to increase the length of the communicating tube portion 3, lower the resonance frequency, and attenuate low-frequency intake noise. Further, when the detected engine speed is high, the deceleration Tanabata 43 is driven to reduce the rack part 41,
The midstream pipe 12 and the tip portion 32 are moved in the opposite direction to the X direction, the pipe length of the communication pipe portion 3 is reduced, and the resonance frequency is increased by 1.
JIlSa V1 Attenuates high frequency intake noise.

In the resonator of the embodiment described below, the following effects occur.

(a) Since the communication pipe part 31 and the downstream pipe 11, the bellows 33 and the bellows 16, and the tip part 32 and the midstream pipe 12 can each be constructed integrally ([!I, since they each constitute a part of the other ), materials are saved, the structure (especially the structure of moving parts) is strong, and assembly is simple. Further, since the intake pipe portion 1 and the communication pipe portion 3 are adjacent to each other and extend in parallel directions, the required volume and the dimension in the longitudinal direction and the perpendicular direction of the intake pipe portion 1 can be reduced.

(Since the bJ pipe length it, II control means 4 is housed inside the resonance chamber 20, the resonator can be further downsized, and leakage of noise generated by the pipe length control means can be reduced. It should be noted that the bellows 33 of the communication pipe section may be replaced with a tube made of an elastic material such as a rubber tube [IT
In this case, the sound absorption effect of the elastic cylinder is
Available. In addition, various means can be employed for expanding and contracting the communication pipe portion 3, and instead of a motor, a diaphragm (or piston) or an air cylinder that is operated by changes in intake pressure can be used. Furthermore, a configuration is also possible in which the piston sliding space of the air cylinder is used as a resonance chamber.

Embodiment 2 A cross-sectional view of the intake & silencer of Embodiment 2 is shown in FIG. The structure of the intake pipe section 1, the communication pipe section 3, and the pipe length control means are partially different from those of the first embodiment.

The intake pipe section 1 includes a small-diameter lower i-pipe 11 and a large-diameter upstream pipe 1.
3, the downstream pipes 11 and the upstream pipes 13 are arranged in a line in the longitudinal direction, and their respective open ends face each other with a distance d between them.

The communication pipe part 3 is slidably held on the upstream pipe 13 so that its inner peripheral surface contacts the outer peripheral part of the upstream pipe 13.
The downstream pipe 11 is inserted into the communication pipe portion 3 from the open end that does not come into contact with the two-flow pipe 13 .

Therefore, in this embodiment, the distance 1111L where the communication pipe section 3 and the downstream pipe 11 overlap when viewed in the Y direction means the pipe length in the present invention.

The pipe length 1IIIi1 means is an air cylinder (not shown) installed adjacent to the upstream pipe 13, and one end of the connecting rod 40 energized by this air cylinder connects to the communication pipe section 3.
is fixed to the outer periphery of the In this embodiment, the communication pipe section 3
Since the pipe length can be controlled simply by sliding the resonator, the structure and operation are simple, and the resonator can be further downsized.

[Effects of the Invention] As explained above, the intake noise muffler for an automobile internal combustion engine according to the present invention has one end connected to the intake pipe section and the other end forming an open end in the resonance chamber. Since it is equipped with a communication pipe section adjacent to the intake pipe section and extending in the same direction as the intake pipe section, the length of which can be varied, the intake pipe section and the communication pipe section are The diameter of the outer cylinder surrounding the resonator can be reduced, and as a result, the volume of the resonator can be reduced, making it easier to store it in the engine room of an automobile.
! can do.

4.L of the drawing! iI'Ii Explanation Figure 1 shows the intake sound 8 of the present invention! FIG. 2 is a schematic sectional view showing one embodiment of the Ig device, taken along line A-A'.

FIG. 3 is a schematic sectional view showing Example 2.

1...Intake pipe part 2...Outer m part 3...Communication pipe section 4... Pipe length $11110 means

Claims (1)

[Claims] (1) An intake pipe section arranged to constitute a part of the intake pipe system of an internal combustion engine; an outer cylinder section that surrounds the intake pipe section and forms a resonance chamber therein; and one end. is connected to the intake pipe part, the other end forms an open end in the resonance chamber, and the pipe length is variable, the communication pipe part extends in the same direction as the intake pipe part and is adjacent to the intake pipe part; An intake noise muffler for an internal combustion engine for an automobile, comprising a pipe length control means for controlling a pipe length of a pipe portion.