JPH0141892Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an intake air supply device for a supercharged internal combustion engine.

<Prior art> In a supercharged internal combustion engine, as shown in FIG. The fuel is supercharged through the engine body 4 and supplied to the combustion chamber of the engine body 4 for combustion. High output is obtained by the supercharging action of the supercharger 3. 3B
is an exhaust turbine of the supercharger 3 installed in the exhaust passage 5.

<Problems to be solved by the invention> However, when starting the engine, where there is almost no supercharging effect from the supercharger 3, the intake compressor 3A of the supercharger 3 creates intake resistance, so compared to a normal internal combustion engine, The amount of intake air decreases. For this reason, there are problems in that oxygen is likely to be insufficient, combustion efficiency is poor due to incomplete combustion, and smoke is likely to occur. Incidentally, as an intake air supply device that switches the intake inlet, there is one disclosed in Japanese Utility Model Application Publication No. 102764/1984.

This idea was made in view of the above circumstances.
The purpose is to increase the amount of oxygen supplied when starting the engine, increasing combustion efficiency and reducing smoke.

<Means for solving the problem> Therefore, in the present invention, an air cleaner with an oxygen-enriching membrane attached to the filter element is provided in the engine intake system in parallel with a normal air cleaner, and an air cleaner connected to each of both air cleaners is installed in the engine intake system. An intake switching means is provided at the junction of the branch passages to selectively supply the intake air from either one of the air cleaners to the combustion chamber, and a detection means for detecting on/off of a key switch and a detection means for detecting the engine speed are provided. When the key switch is on and the engine speed is below the idle speed, intake air from the air cleaner equipped with the oxygen enriched membrane is supplied to the combustion chamber based on the detection signals from both the detection means and the key switch is on and the engine is rotating. and a driving means for driving the intake air switching means to supply intake air from the normal air cleaner to the combustion chamber when the number of rotations exceeds the idle rotation number.

<Function> As a result, when the key switch is on and the engine starts when the engine speed is below the idle speed, intake air from the air cleaner with an oxygen-enriched membrane provided on the filter element is supplied to the combustion chamber. It can increase the oxygen concentration of the air. In addition, when the engine speed exceeds the idle speed, the air cleaner side is normally connected to the combustion chamber and the air cleaner equipped with an oxygen enriched membrane is not used. It can be extended.

<Example> Hereinafter, an example of the present invention will be described based on the drawings. Incidentally, the same parts as in the prior art are given the same reference numerals, and the description thereof will be omitted.

In FIG. 1, reference numeral 11 denotes an air cleaner equipped with an oxygen-enriching membrane that allows oxygen to permeate preferentially through a built-in filter element, and is installed in the intake passage 2 in parallel with the ordinary air cleaner 1. 11a is an air inlet of the air cleaner 11. At the confluence of the intake branch passages 2A and 2B that connect to these air cleaners 1 and 11, respectively,
A switching valve 12 as an intake switching means shown in FIG. 2 is installed to selectively connect one of the intake branch passages 2A and 2B to the intake passage 2.

Reference numeral 13 denotes a control unit, which includes a rotation speed sensor 14 for detecting the engine rotation speed mounted on the engine body 4.
Starting of the engine is detected based on the engine speed signal from the engine and a signal from a key switch (not shown).
15 is an excitation coil 15a that is excited by the output from the control unit 13, and a battery 1.
6 and a normally open contact 15b connected in series between the three-way solenoid valve 17.

The three-way solenoid valve 17 is interposed in an air passage 20 for supplying compressed air from an air reservoir 19 to an air cylinder 18 as a driving means for driving the switching valve 12, and when energized, the air cylinder 18 The air cylinder 18 is connected to the air reservoir 19, and the air cylinder 18 is opened to the atmosphere during demagnetization.

The air cylinder 18 has a built-in return spring 18A, and the tip of a rod 18C connected to a piston 18B is connected to a support shaft 21 of the switching valve 12 via a lever 22. 23 is a stopper.

Next, the action will be explained.

A control unit 13 detects the operating state of the engine based on signals from a rotation speed sensor 14 and a key switch. Then, the engine rotation speed signal from the rotation speed sensor 14 is determined as the idle rotation speed (for example,
400rpm) or less and the key switch is on,
It is determined that it is time to start the engine, and the relay 15 is energized and its normally open contact 15b is closed. Then, an exciting current flows from the battery 16 to the three-way solenoid valve 17 via the relay 15, and compressed air is supplied to the air cylinder 18 by communicating the air cylinder 18 and the air reservoir 19 via the air passage 20. As a result, the piston 18B of the air cylinder 18 moves against the elastic force of the return spring 18A, and rotates the lever 22 via the rod 18C until it comes into contact with the stopper 23. Along with this, the switching valve 12 also rotates together via the support shaft 21 to the position shown by the chain line in FIG.
Conversely, the intake branch passage 2B on the side of the air cleaner 11 having the oxygen-enriched membrane is communicated with the intake passage 2.

Therefore, when starting the engine, the intake air from the air cleaner 11 having an oxygen-enriched membrane is supplied to the combustion chamber of the engine body 4, so that the oxygen concentration in the intake air is approximately 20%.
This increases the amount of oxygen to around 50%, ensuring a sufficient amount of oxygen even if the amount of intake air is insufficient. Therefore, the combustion efficiency at the time of starting the engine is improved, and smoke can be reduced.

On the other hand, if the engine speed exceeds 400 rpm after the engine is started, the output from the control unit 13 is stopped due to the signal from the rotation speed sensor 14.
When the relay 15 is demagnetized, the normally open contact 15b, which is in the closed state, is opened, and the three-way solenoid valve 17 is demagnetized. Then, since the air cylinder 18 is opened to the atmosphere, the piston 18B is returned to its original position by the return spring 18A, and the switching valve 12 is moved to the solid line in FIG. 2 via the rod 18C, lever 22, and support shaft 21. position to communicate the intake branch passage 2A on the side of the normal air cleaner 1 with the intake passage 2,
The intake branch passage 2B on the side of the air cleaner 11 having an oxygen-enriched membrane is isolated from the intake passage 2.

Therefore, during engine operation other than when starting the engine, intake air from the normal air cleaner 1 is supplied to the combustion chamber as in the conventional case. In this way, during engine operation where sufficient combustion can be achieved even with intake air from the normal air cleaner 1, by using the normal air cleaner 1, the oxygen enriched membrane, which is inferior in durability to the normal air cleaner 1, can be used. Air cleaner 11 having
Air cleaner 1
1 can be used effectively.

Although this embodiment shows an example in which the present invention is applied to an internal combustion engine with a supercharger, it goes without saying that the present invention can also be applied to a normal internal combustion engine.

<Effects of the invention> As described above, according to the invention, an air cleaner with an oxygen enriched membrane is used only when starting the engine, from when the key switch is turned on until the engine speed exceeds the idle speed, and other air cleaners are used. Since the configuration uses a regular air cleaner during engine operation, a sufficient amount of oxygen can be supplied when the engine starts, when the amount of oxygen tends to be insufficient, improving combustion efficiency when starting the engine and suppressing the generation of smoke. Furthermore, by reducing the frequency of use of the air cleaner equipped with an oxygen enrichment membrane, the service life can be extended.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention;
Figure 2 is a sectional view of the intake switching section of the same embodiment as above;
The figure shows a configuration diagram of the switching valve driving section of the same embodiment as above, and FIG. 4 shows a configuration diagram of a conventional example. 1...Air cleaner, 2...Intake passage, 2A,
2B...Intake branch passage, 4...Engine body, 11...
. . . Air cleaner equipped with oxygen enrichment membrane, 12 .

Claims (1)

[Scope of utility model registration request] In a supercharged internal combustion engine, an air cleaner with an oxygen-enriching membrane attached to a filter element is installed in the engine intake system in parallel with a normal air cleaner, and an air cleaner is installed in the engine intake system at the confluence of the intake branch passages connected to each of the air cleaners. An intake switching means for selectively supplying intake air from either side of the air cleaner to the combustion chamber is provided, and a detection means for detecting on/off of the key switch, a detection means for detecting the engine speed, and a detection means for detecting the engine speed. Based on the detection signal, when the key switch is on and the engine speed is below the idle speed, intake air from the air cleaner equipped with the oxygen enriched membrane is supplied to the combustion chamber, and when the key switch is on and the engine speed exceeds the idle speed. 1. An intake air supply device for an internal combustion engine, comprising: a driving means for driving said intake air switching means to supply intake air from said normal air cleaner to a combustion chamber when said normal air cleaner is in use.