JPS5913335Y2 - engine air purifier - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an air purifying device for an engine that includes a resonator for reducing noise in the middle of an intake passage.

Generally, engine noise is generated from the outer periphery of the engine and the exhaust pipe, but most of this noise can be reduced by adopting noise-proof engine compartments and efficient mufflers.

However, the low-frequency noise emitted from the intake vents contains pure tone components from the first to the third order, and in order to effectively reduce this, a resonator with a sufficiently long neck is required.
It is necessary to use multiple resonators.

However, the former method of lengthening the neck part has the disadvantage that the resonator itself becomes large and requires a lot of space for installation.

Furthermore, the latter method using a plurality of resonators has a problem in that the noise effect is reduced due to mutual interference of the resonators.

This invention was made for the purpose of improving this problem, and provides an engine air purifying device that is equipped with a resonator that is effective against pure tone component noise in the middle of the intake passage.
This is intended to reduce the noise emitted from the intake holes.

This invention will be described in detail below with reference to an illustrated embodiment.

In the figure, reference numeral 1 denotes an air purifier main body (not shown) for an engine, in which air is taken in from the upper end of an intake pipe 2 erected above, is purified by a cleaner element 3 in the main body 1, and then passes through an outlet 4 to a resonator 5. and into the engine's intake manifold (both not shown).

The resonator 5 is located on the outlet 4 side of the main body 1 and has a square box shape with a sealed structure, and the inside is divided into an upper chamber 5b and a lower chamber 5C by an oblique partition wall 5a as shown in FIG. The upper chamber 5b is further divided into a plurality of chambers 50, 5□, and S by a partition wall 5d. These chambers 5□ to 53 are formed by a plurality of cylindrical necks 5 having different lengths l and opening areas S defined in the partition wall 5a.
e, each having a different frequency, for example 100 H.
2, 200H2, and 300H2 low frequencies can be attenuated and absorbed.

That is, the resonator 5 has a volume of the chambers 5 to 53, and
The resonance frequency is determined by the following equation based on the opening area S of the neck 5e leading to the lower chamber 5C and the length l of the neck 5e.

Therefore, depending on the frequency to be attenuated, the volumes of the chambers 51 to 53,
By determining the opening area S of the neck portion 5e and the length 1 of the neck portion 5e, it becomes possible to attenuate a desired frequency.

As described in detail above, this device is capable of effectively reducing the noise of the first to third order components in the intake air by the plurality of neck portions 5e provided in the resonator 5 with different lengths and opening areas. Since there is no need to increase the length of the neck portion 5e, the resonator 5 itself can be made compact and can be easily installed in a small space.

Furthermore, since there is no mutual interference compared to the case where a plurality of resonators are used, there is no risk of reducing the noise reduction effect.

[Brief explanation of the drawing]

The drawings show an embodiment of this invention, with FIG. 1 being an overall partially cutaway side view, and FIG. 2 being a partially cutaway perspective view of the resonator. 2 is an intake pipe, 3 is a cleaner element, and 5 is a resonator.

Claims (1)

[Scope of utility model registration request] There is a partition wall 5a inside the air intake path leading to the engine via the air intake 2, the cleaner element 3 and the intake manifold.
is divided into an upper chamber 5b and a lower chamber 5C, and the upper chamber 5b is further divided into a plurality of chambers 5□, 52, 5a by a partition wall 5d, and each chamber 50 of the lower chamber 5C and upper chamber 5b,
5□, 53 are communicated with each other by a cylindrical neck portion 5e having a different length l and opening area S provided on a partition wall 5d.