JPS6385251A - Air cleaner for internal combustion engine - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an air cleaner device for an internal combustion engine, and more particularly to an air cleaner device equipped with a long cool air duct for introducing outside air.

(Prior Art) In order to prevent wear of internal combustion engines, air cleaner devices that remove dust and the like from intake air have been conventionally used. By the way, when an air cleaner device is attached to an internal combustion engine, the rotational speed at which the volumetric efficiency of the internal combustion engine is maximized shifts to a lower rotational speed range than when no air cleaner device is attached, as shown in FIG. For this reason, there was a problem in that the torque in the high rotation range was significantly reduced.

In addition, for the purpose of improving engine output, there is an air cleaner device in which a long cool air duct is attached to the air intake port so that relatively low temperature outside air can be introduced while avoiding intake of F air in the aircraft's airspace. This cool air duct is also highly effective in reducing intake noise, and is especially used in most vehicle internal combustion engines. However, the cool air duct arrangement increases the length of the intake system, and as seen in FIG. 15, the rotational speed at which the maximum volumetric efficiency is achieved becomes even lower, making the above-mentioned disadvantages even more pronounced.

In order to solve these problems, conventional measures have been taken to improve the inertia effect on the intake air by changing the acoustic characteristics of the intake system, such as by drilling small holes in the air cleaner device or installing a resonance device. is being attempted. Further, Japanese Utility Model Publication Nos. 38-9001 and 9002 propose a structure in which an auxiliary air inlet is provided in an air cleaner device and the auxiliary inlet is opened and closed using pulp depending on the amount of intake air.

(Problems to be Solved by the Invention) The conventional improvement measures described above have the problem that the structure of the air cleaner device becomes complicated, resulting in increased cost and installation space. The problem remained that the volumetric efficiency could not be sufficiently improved in the middle and high rotation ranges.

In view of the problems of the prior art described above, an object of the present invention is to improve the acoustic characteristics of an intake system including a cool air duct with a simple configuration, and to provide an air cleaner that can obtain high volumetric efficiency over a wide rotation range of an internal combustion engine. The purpose is to provide equipment.

(Means and effects for solving the problem) For the above-mentioned purpose, the air cleaner device for an internal combustion engine according to the present invention has the following features:
A first inlet comprising a casing housing a filtration element assembly and a first inlet forming a cool air duct and joining the casing to introduce air toward the center of the element assembly, the first inlet forming another cool air duct. The two inlets are aligned on the axis of the first inlet so as to introduce air toward the center of the element assembly, and a valve is provided in either the first or second inlet to open and close the inlet. The present invention is characterized in that it further includes a 1IIJiall device that controls the opening and opening operation between the valves 5A in accordance with the rotation of the internal combustion engine.

According to the present invention, in the low speed range of the internal combustion engine, the valve device closes the intake air through either the first or second inlet, and as in the case where the conventional device is installed, High volumetric efficiency can be obtained. On the other hand, when the valve device is opened in the medium and high speed range, the pressure waves generated in the cylinder of the internal combustion engine are divided into the first and second inlets, are reflected at the atmosphere-open ends of these inlets, and are directed toward the casing. propagates and collides and interferes within the casing.

This changes the acoustic characteristics of the intake system, improving volumetric efficiency even in medium and high speed ranges.

In addition, regardless of whether the intake air is passed through the first or second inlet, the intake air is introduced toward the center of the element assembly and evenly passes over the entire surface of the assembly. Therefore, there is no early clogging of the element due to local accumulation of dust, and ventilation resistance can be lowered.

(Example) Hereinafter, the present invention will be described based on an example shown in the accompanying drawings.

FIG. 1 shows the overall composition of an air cleaner device 1 according to a first embodiment of the present invention. The air cleaner device 1 includes a casing composed of a shallow pot-shaped case 2 and a cap 5 attached to the lower part of the case. An axial air filtration element assembly 3 is accommodated in this casing substantially coaxially with the casing. Case 2 is the first for intake air introduction.
It has an inlet 4 which is joined to the side of the case with its longitudinal axis directed towards the central axis of the case. The cap 5 is removable so that the element assembly 3 can be replaced, and has an air outlet 5a formed therein.

The first inlet 4 constitutes a long cool air duct that opens outside the engine room so that low-temperature outside air can be taken in. Further, the outlet 5a of the cap 5 is connected to a carburetor or the like (not shown) of an internal combustion engine.

The first inlet 4 has a rectangular cross section, and the second inlet 6 is provided inside the first inlet 4. As shown in FIGS. 2 and 3, the second inlet 6 is defined by a trough-like member fixed to the upper inner wall of the first inlet 4. As shown in FIGS.

This gutter-like member is arranged in alignment with the axis of the first inlet 4 so as to direct the intake air toward the center of the element assembly 3 similarly to the first inlet 4. The case-side open end 6a of the second inlet is disposed near the center of the case beyond the joint 4a between the case 2 and the first inlet 4. The open end 6a has a large width in the lateral direction to ensure an opening area so as not to increase ventilation resistance. By installing the second inlet 6, the inside of the inlet 4 is partitioned into a first intake passage 4b and a second intake passage 6b.

The air cleaner device 1 further includes a valve device 7 and a control device 8 connected to the valve device.

The valve device 7 includes a valve member 71 disposed within the second inlet 6.
and a vacuum motor 72 connected to the valve member. The valve member 71 is rotatably supported by a shaft 73, and opens and closes the second intake passage 6b in accordance with the drive of the vacuum motor 72.

Further, the control device 8 includes an N magnetic switching valve 81 and a CPIJ 82. The vacuum motor 72 of the valve device 7 is operated by negative pressure, and the electromagnetic switching valve 81 is configured to supply negative pressure from a negative pressure source 9 such as a vacuum tank to the negative pressure chamber of the vacuum motor 72. Connected. CPU
82 performs calculations using the rotational speed of the internal combustion engine as an input signal;
The result is output to the electromagnetic switching valve 81. Solenoid switching valve 81
Based on this instruction, for example, when the power is on, the negative pressure source 9 and the vacuum motor 72 are connected and negative pressure is guided to the negative pressure chamber of the vacuum motor, and when the power is off, the negative pressure chamber is opened to the atmosphere. I do.

The configuration of the CPU 82 will be described below with reference to the block diagram in FIG. The CPU 82 has an input side electrically connected to an m-pickup type engine rotation speed sensor 110 that generates a pulse signal train corresponding to the rotation speed according to the rotation of the internal combustion engine, and an output side electrically connected to the electromagnetic switching valve 81. has been done. The CPU 82 includes a pulse generation circuit 111 configured to generate a pulse signal based on a signal generated by the rotation speed sensor 110. The CPU 82 further includes a rotational speed detection circuit 114, which detects the period of the pulse signal from the pulse generation circuit 111 and
Based on the constant frequency clock signal C1 from 2, the reciprocal of the engine rotation speed is detected, and this detection signal is converted into a binary code and sent to the microcomputer 11.
Output to 3. Furthermore, the microcomputer 113 executes processing as described later based on the clock signal C2 of the clock circuit 112, and outputs a control signal to the drive circuit 115 that causes the drive NFi to flow to the electromagnetic switching valve 81.

When the microcomputer 113 is powered on, the fifth
Start the process as shown in the figure.

First, in step 201, initial processing is performed only at the start. For this initial processing, for example, R
This includes initial value sets for AM, initial value sets for input/output boards, initial value sets for microcomputer operation, etc.

Subsequently, the process for controlling the opening and closing of the valve device 7 is executed by repeating the process from step 202 to step 206 as one block.

First, cycle data A of the engine rotation signal is read from the rotation speed detection circuit 114 (step 202). Next, cycle data 8 is inverted and scaled to N- using the formula 1.1/A to obtain engine rotation speed N (step 203
). This engine rotation speed N and the engine rotation speed N0, which is the reference for opening the electromagnetic switching valve 81 and switching to either the idle mode.
(See Figure 6) Compare the size with Step 2o4),
When N<No, a corresponding control signal is output to the drive circuit 115 to close the valve member 71 (step 206). On the other hand, when N≧N0, a corresponding control signal is output to the drive circuit 115 so as not to open the valve member 71 (step 205).
. Thereafter, the process moves to step 202 and the above-described process is repeated.

Thus, according to the embodiment described above, when the rotation speed of the internal combustion engine is in the low rotation range below the predetermined value, the valve member 71
The intake passage 6b is closed.

Therefore, low-humidity outside air is drawn in only through the first inlet 4. The air that has passed through the first intake passage 4b is transferred to the case 2.
and is filtered through the entire surface of the element assembly 3. The air purified in this way is then taken into the carburetor of the internal combustion engine through the outlet 5a below the element assembly 3.

On the other hand, when the rotational speed of the internal combustion engine reaches a medium to high rotational speed range above a predetermined value, the valve member 71 is rotated to open the second intake passage 6b. Therefore, outside air flows through the first inlet 4 and the second inlet.
It is divided into inlet 6 and introduced into the air cleaner device.
After purification, it is inhaled into the carburetor of the internal combustion engine through the outlet 5a. Note that the intake air is introduced to the center of the element assembly 3 without being deflected, and passes through the entire surface of the assembly with low ventilation resistance. As a result, dust and the like do not stick to the element assembly in a biased manner, and early clogging of the element assembly 3 is prevented.

During the above operation, the pressure waves generated in the internal combustion engine are directed from inside the casing to the outside of the intake system through the first and second inlets 4.6, and the first and second inlets are opened to the atmosphere. It is reflected at the edge and returns to the casing. The return propagating pressure waves collide with each other within the casing and change the acoustic properties of the intake system. As a result, it becomes possible to eliminate the influence of the length of the intake system, and as shown in the characteristic diagram in Figure 6, the volumetric efficiency in the middle and high rotation ranges is improved.
Good volumetric efficiency can be obtained over a wide rotation range of the internal combustion engine.

Next, a further embodiment of the present invention will be described. In the following description, only the constituent parts that are different from the above-mentioned first embodiment will be mentioned, and the illustrations of the same parts as in the first embodiment will be omitted, or the same reference numerals will be used to describe them in detail. Omitted.

In the second embodiment shown in FIG. 7, the first intake passage 4b is formed such that the direction of air discharge at the outlet portions on both sides of the second inlet intersects that of the second intake passage 6b. That is, in this embodiment, the case-side open end 61a of the second inlet is arranged at a position substantially aligned with the joint 41a between the case 2 and the first inlet. Further, on both sides of the open end 61a, there are provided chevron-shaped projecting portions 61b that project laterally into the first intake passage 4b. On the other hand, the alignment portion 41 facing these overhang portions 61b
The portion a is curved □ along the outer shape of the overhang. According to this configuration, a part of the air that has passed through the first intake passage 4b collides with the air introduced through the second intake passage 6b, and the two can more actively interfere with each other within the casing.

Figures 8 to 11 illustrate embodiments with first and second gastric inlets, respectively located and shaped. In the embodiment shown in FIG. 8, contrary to the first embodiment described above, a gutter-like member is fixed to the lower inner wall of the first inlet 4 to form the second inlet 16. In the embodiment shown in FIG. 9, the second inlet 26 is formed into a tubular shape with a rectangular cross section smaller in size than the first inlet 4, and is supported by a support member (not shown) and coaxially mounted within the first inlet 4. Retained. In addition, in the actual FM example in Fig. 10,
The first and second inlets 34, 36 are integrally formed in a vertical arrangement and have substantially the same cross-sectional shape. In the embodiment shown in FIG. 11, the first and second inlets 54.
56 are integrally formed in parallel arrangement, and the second inlet 56
A pair of first intake passages 54b, 54b are provided on both sides.

Still another embodiment will be described with reference to FIGS. 12 to 14. The air cleaner device 91 of this embodiment has a casing composed of a shallow pot-shaped case 92 and a removable cap 95 attached to the upper part of the case. A chrysanthemum-shaped filter element assembly 93 is housed in this casing, and an air outlet 92a is provided at the bottom of the case 92.
is drilled. Furthermore, a tubular member 100 having a rectangular cross section is joined to the side of the case 92 with its longitudinal axis directed toward the central axis of the case 92 .

A flat separator plate 101 is mounted within the tubular member 100 . The separator plate 101 extends at approximately the midpoint in the vertical direction of the tubular member, and the tubular member 100 is partitioned into upper and lower sections to define second and first inlets 96,94. As in the previous embodiment, the valve member 71 is disposed in the second inlet 96, and the vacuum motor 7
2 is connected to this valve member. The casing-side end 101a of the separator plate 101 extends into the case 92 to a position that surrounds the element assembly 93 approximately halfway around it. The end portion 101a of the separator plate acts as a pressure wave interference prevention means, and pressure waves propagating back through the first and second inlets 1 to 94.98 interfere with each other near the joint between the case 92 and the tubular member 100. prevent it from attenuating.

Although the present invention has been described above based on illustrative examples, the present invention is not limited to these. For example, in the above-described embodiment, the second inlet is formed to be smaller than or equal to the first inlet, and the second inlet is provided with a valve device. A valve device may be provided in one inlet.

(Effects of the Invention) According to the present invention, the influence of the length of the intake system including the cool air duct can be removed and the acoustic characteristics can be improved by using an extremely simple structure that does not involve a significant increase in cost. . Therefore, good volumetric efficiency can be obtained over a wide rotation range of the internal combustion engine, and power performance can be improved.

In addition, since the configuration is such that air is introduced towards the center of the element assembly and passes through the entire surface, the element can be used efficiently until its intended lifespan, and the ventilation resistance of the entire air cleaner device is reduced. be done.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the overall configuration of an air cleaner device for an internal combustion engine according to a first embodiment of the present invention, FIG. 2 is a cross-sectional plane opening of the first embodiment, and FIG. 3 is a line taken along line III-III in FIG. 4 is a block diagram showing the configuration of the CPU used in the first embodiment, FIG. 15 is a 70-chart showing the processing of the microcomputer of the same CPU, and FIG. A diagram showing a comparison of the characteristics with a conventional device, FIG. 7 is a sectional plan view showing the second embodiment, and FIGS. 8 to 11 are the third and fourth embodiments of the present invention, respectively. , FIG. 12 is a cross-sectional side view showing the seventh embodiment, FIG. 13 is a cross-sectional plan view of the seventh embodiment, and FIG. 14 is a cross-sectional view showing the seventh embodiment. -XIV I and FIG. 15 are diagrams comparing the characteristics of the internal combustion engine when an air cleaner is installed and when an air cleaner with a cool air duct is installed. In the figure, 1.91...air cleaner device, 2,92...
・Case, 5.95...Cap, 3.93...Element assembly, 4,34,54.94...1st inlet, 6,16.26,36.56.96...No. 2
Inlet, 7...valve device, and 8...control device.

Claims (4)

[Claims] (1) An air cleaner device for an internal combustion engine, which includes a casing that houses a filtration element assembly, and a first casing that forms a cool air duct and is joined to the casing so as to introduce air toward the center of the element assembly. A second cool air duct comprising an inlet and a second cool air duct.
The inlet is aligned with the axis of the first inlet so as to introduce air toward the center of the element assembly, and the inlet is opened/closed in either one of the first and second inlets. A valve device is provided to
The air cleaner device for an internal combustion engine further includes a control device that controls opening and closing operations of the valve device according to the rotation of the internal combustion engine. (2) The air cleaner device for an internal combustion engine according to claim 1, further comprising pressure wave interference prevention means disposed near a joint between the first inlet and the casing, the first and second inlets An air cleaner device for an internal combustion engine that prevents attenuation of pressure waves propagated into the casing from mutual interference in the vicinity of the joint. (3) In the air cleaner device for an internal combustion engine according to claim 2, the second inlet is formed by a small-diameter gutter-like member disposed within the first inlet, and the pressure wave interference prevention means An air cleaner device for an internal combustion engine, comprising an end portion of the gutter-like member extending beyond the joint portion toward the center of the casing. (4) In the air cleaner device for an internal combustion engine according to claim 2, the pressure wave interference prevention means is constituted by a separator plate that partitions open ends of the first and second inlets near the joint. Air cleaner device for internal combustion engines.