JPS6124687Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to an air cleaner for an engine.

In an engine, during the intake stroke, negative pressure is generated at the valve side end of the intake passage due to the suction action of the piston, and this negative pressure becomes a negative pressure wave that propagates inside the intake passage toward its open end. Repeated propagation of a negative pressure wave and a positive pressure wave occurs in the intake passage, which is reflected at the end and becomes a positive pressure wave and propagates inside the intake passage towards the valve side end.

Generally, the time it takes for the negative pressure wave generated from the valve side end to be first reflected at the open end of the intake passage and become a positive pressure wave and return to the valve side end is shorter than the intake time (valve opening time), so during the period when the intake valve is open, the negative pressure wave and the reflected positive pressure wave overlap in the intake passage, and a composite wave of the two is generated in the intake passage.
Therefore, if the time required for the negative pressure wave to return as a positive pressure wave is adjusted so that this composite wave reaches its maximum just before the intake valve closes, the so-called inertia effect can be obtained, which increases the volumetric efficiency of the engine and increases engine output.

Also, after the intake valve closes, pressure oscillations remain in the intake passage, and these residual waves gradually attenuate, but when the positive pressure wave synchronizes with the intake stroke of the next cycle, the pressure at the beginning of the intake stroke This will further increase the volumetric efficiency of the engine. However, in this case, when the negative pressure wave synchronizes with the suction stroke of the next cycle, the pressure when the valve opens decreases, and the volumetric efficiency conversely decreases. The influence of the residual waves in the intake passage on the intake stroke of the next cycle is called the pulsation effect. Whether the residual wave synchronized with the intake stroke of the next cycle is a positive pressure wave or a negative pressure wave is determined by the ratio between the frequency of the residual wave and the engine rotation speed.

By the way, the frequency of the residual wave required for the negative pressure wave emitted from the valve side end to be first reflected at the open end of the intake passage and return to the valve side end as a positive pressure wave is:
Determined by the equivalent length of the intake passage and the speed of sound. Therefore, if the equivalent pipe length of the intake passage is set appropriately, good inertia effect and pulsation effect can be obtained.

The equivalent length of the intake passage is inversely proportional to the cross-sectional area of the intake passage, and directly proportional to the passage length between the valve side end and the open end.

Generally, the open end of the intake passage in an engine is the air outlet of the air cleaner, and therefore the length of the passage is the length of the passage between the air outlet of the air cleaner and the intake port of the engine.

In order to increase the equivalent pipe length of the intake passage in terms of compatibility with the engine, it is conceivable to reduce the cross-sectional area of the intake passage and to increase the length of the passage.
However, if the cross-sectional area of the intake passage is reduced,
Intake resistance increases during high-speed operation, resulting in a decrease in engine output. In addition, increasing the length of the passage is subject to space constraints, and if the placement positions of the engine and the air cleaner are determined and the distance between them cannot be changed freely, the length of the passage may be increased. It may not be possible to set the length to a given value. Recently, more and more devices are installed in the engine room due to exhaust gas purification measures, and it has become difficult to determine the location of each device. It often happens that it cannot be placed in the correct position.

It is also conceivable to set the length of the intake passage between the air cleaner and the engine to an appropriate length by making it meander. However, in this case, there are drawbacks such as an increase in the number of parts constituting the intake passage, and furthermore, due to space constraints, the intake passage may not be able to meander to have the required length.

In view of the above-mentioned problems, the present invention is designed so that the mounting position of the engine and the air cleaner is determined, and the length of the intake passage between the air intake port of the air cleaner and the intake port of the engine is set to a certain value. To provide an air cleaner that can extend the length of an intake passage to an appropriate length without being subject to space constraints or requiring special space.

This purpose, according to the invention, is achieved by defining a chamber space therein and connecting an air inlet to an air outlet and an end opening and a first opening of said chamber space for inserting an annular filter element into said chamber space. a dirty side chamber defined on the outside of the annular filter element which is a part and which is loaded in the chamber space; and a second part of the chamber space which is a part of the annular filter element which is loaded in the chamber space; a case body having a clean side chamber defined in an inner portion of the element; a cover closing the end opening of the case body; and a case assembly comprising the case body and the cover, the annular filter means for retaining an element; and an air conduit extending substantially the entire length of the clean side chamber through the air outlet into the clean side chamber to an inner end thereof; A portion near the inner end is formed with a plurality of through holes to provide a hydrodynamically effective length of the air conduit to a selected length different from the physical length of the conduit to the end. This is achieved by an engine air purifier characterized by:

In an engine connected to an air purifier as described above, the open end of the intake passage due to its hydrodynamic characteristics is the outer end of the air conduit inserted into the clean side chamber from the air intake port of the case body. This becomes the opening of the through hole provided nearby, and the length of the intake passage is appropriately extended inside the air purifier by this air conduit, and at the same time, the length of the air conduit is extended as appropriate inside the air purifier. Apart from its physical length, which affects the attachment, by appropriately modifying the design of the plurality of through holes, it is easy to set the hydrodynamic length to a length that ensures the most effective inertial effect. achieved. Further, due to the structure in which the air conduit opens into the clean side chamber of the air purifier through a plurality of through holes at its inner end, a muffler effect that reduces intake noise can also be obtained.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a half-sectional view showing one embodiment of an air purifier according to the present invention, and FIG. 2 is a plan view thereof. In the figure, reference numeral 1 indicates a case assembly, which includes a cylindrical deep-bottomed case body 2 having an element entry/exit opening at one end, and a cylindrical shallow-bottomed cover that closes the opening. It consists of 3. A mounting member 4 is attached to the case body 2 for attaching it to the side wall of an engine or the frame of a vehicle. In this embodiment, the case main body 2 has an element entry/exit opening at its lower bottom. The cover 3 is removably attached to the case body 2 by a fastener 5 as a bottom member of the case assembly so as to close the opening.

A partition plate 6 is installed near the upper end wall of the case body 2 and extends parallel to the upper end wall.
This partition plate 6 defines a chamber 8 between it and the upper end wall. The case body 2 has an air intake port 9 in its side peripheral wall, and this air intake port 9 is open toward the interior of the chamber 8. In addition, an air intake conduit 1 connected to an air intake port 9 at one end is provided on the side peripheral wall of the case body 2.
0 is installed. The air intake conduit 10 extends substantially tangentially to the outer circumference of the case body 2. Therefore, the air taken into the chamber 8 through the air intake conduit 10 is guided by the inner circumferential wall of the case body 2 and becomes a swirling flow around the axis of the case body 2.

The partition plate 6 has a plurality of openings 7 on its outer periphery.

An annular filter element 11 is disposed within the case body 2 below the partition plate 6 and coaxially with the case body. The filter element 11 is a bottom plate 1 that is removably attached to the case body 2 in a manner that will be described later.
2 and the partition wall plate 6 in a sandwiched manner. The partition wall plate 6 and the bottom plate 12 each have an annular seal member 1 on the engagement surface with the filter element 11.
3 and 14 are attached. Filter element 11
The outside of the filter element 11 is a dirty side chamber 15 communicating with the opening 7, and the inside of the filter element 11 is a clean side chamber 16.

An air outlet 17 is opened in the center of the upper end wall of the case body 2. An air conduit 18 passes through the air outlet 17. Air conduit 18 is connected to chamber 8
, and extends through an opening 19 provided in the partition plate 6 into the annulus of the filter element 11, ie into the clean side chamber 16, over substantially its entire length. A stay 20 is attached to the tip of the air conduit 18, and the bottom plate 12 is detachably attached to the stay 20 with bolts 21 and wing nuts 21. The air conduit 18 is bent into an L shape at a portion that protrudes outward from the case body 2, and is connected at its tip to the carburetor of the engine via an air hose or the like (not shown).

A plurality of through holes 23 are provided near the inner end of the air conduit 18 on the side where the stay 20 is provided.

According to the air cleaner configured as described above, since the air conduit 18 extends into the pipe of the filter element 11, the intake passage of the engine is extended accordingly, and the through hole provided at the inner end thereof is extended. Hole 2
By appropriately designing 3, it is possible to suitably modify the hydrodynamic effective length of the air conduit 18 while keeping its overall physical length unchanged, thereby improving the hydrodynamics of the engine intake passage. The effective overall length can be determined so that the influence of the inertial effect of air intake is most effective.

[Brief explanation of the drawing]

FIG. 1 is a half-sectional view showing one embodiment of an engine air cleaner according to the present invention, and FIG. 2 is a plan view thereof. DESCRIPTION OF SYMBOLS 1-Case assembly, 2-Case body, 3-Cover, 4-Mounting member, 5-Fastener, 6-Partition plate, 7
~opening, 8~chamber, 9~air intake, 10~air intake conduit, 11~filter element, 12~bottom plate, 1
3, 14 - Annular seal member, 15 - Dirty side chamber, 16 - Clean side chamber, 17 - Air intake port, 18 - Air conduit for adjusting intake passage length, 19 - Opening, 20 - Stay, 21 - Bolt, 22 - Butterfly Nut, 23~ hole.

Claims (1)

[Scope of utility model registration request] defining a chamber space therein, an air inlet, an air outlet, an end opening for inserting an annular filter element into the chamber space, and a first portion of the chamber space; a dirty side chamber defined in an outer portion of said annular filter element loaded and a second portion of said chamber space defined in an inner portion of said annular filter element loaded within said chamber space; a case body having a clean side chamber; a cover closing the end opening of the case body; means for retaining the annular filter element within a case assembly comprising the case body and the cover; an air conduit extending substantially the entire length of the clean side chamber through the air intake port and into the clean side chamber to an inner end thereof, a portion of the air conduit near the inner end being A plurality of through holes are formed to set the hydrodynamically effective length of the air conduit to a selected length different from the physical length of the conduit to the end. Air purifier for engines.