JPS58143119A - Suction device for engine - Google Patents

Abstract

PURPOSE:To reduce the loss of operation as well as to make a supercharger and a supercharging system small-sized by supplying the oxygen-rich air enriched in an oxygen-enricher to a supercharging passage as a supercharging air. CONSTITUTION:When the load of an engine is low, an oxygen-concn. controller 26 is operated to control a switch valve 12 to be perfectly closed and an oxygen- concn. control valve 18 to be fully opened, and a switchover valve 32 and a valve selector 34 are kept unoperated. The oxygen-rich air from an oxygen-rich air supply passage 13 is supplied to the engine 1 via a main suction passage 2. When the load of the engine is high, the switch valve 12 is opened, the oxygen- concn. control valve 18 is closed, the switchover valve 32 and the valve selector 34 are operated to connect the oxygen-rich air supply passage 13 with an auxiliary suction passage 27, and an auxiliary suction valve 33 are operated for opening and closing. A suction pump 7 works as a supercharger.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine intake system, and more particularly to an engine intake system equipped with an oxygen concentration enrichment device that increases the oxygen content ratio in the air.

Generally, an engine supplies fuel to air at a predetermined air-fuel ratio and burns it, and extracts this thermal energy as shaft output. The air used for this combustion usually contains about 21 inches of oxygen, about 78 inches of nitrogen, and the remainder is made up of gases such as argon, carbon dioxide, and hydrogen. Of these, only oxygen substantially contributes to combustion, and nitrogen, which accounts for a large proportion, has an endothermic effect, so
It functions to inhibit combustion by slowing down the combustion speed and worsening combustion stability.

Therefore, conventionally, as disclosed in JP-A No. 56-50253, an engine is equipped with an oxygen concentration enrichment device that increases the oxygen content ratio in the air. It has been proposed to improve the combustion performance of the engine by supplying oxygen-rich air to the engine, thereby increasing the oxygen content ratio of the intake air as much as possible. The principle method of the above-mentioned oxygen concentration enrichment device is as follows: (a) As described in the above-mentioned publication, an oxygen-permeable membrane made of multiple layers of silicone rubber membranes is used, and air is sent from one side of the oxygen-permeable membrane to the other side. The so-called oxygen permeation method obtains oxygen-rich air by suctioning from the side and allowing a large amount of oxygen to permeate due to the difference in dissolution rate between oxygen and nitrogen due to this pressure difference, and (b) a container filled with pellet-shaped synthetic zeolite. A so-called nitrogen adsorption method is mainly known in which air is sent under pressure, a large amount of nitrogen is adsorbed on zeolite, and suspended oxygen is removed to obtain oxygen-rich air.

On the other hand, it is known that an engine is equipped with a supercharger, and the supercharger supercharges intake air to increase the filling efficiency of the intake air, thereby increasing the output of the engine.

However, in the above-mentioned conventional supercharged engine, the intake air to be supercharged is pressurized air with a normal oxygen concentration (approximately 21 inches), so the content ratio of oxygen that substantially contributes to combustion is low, and its However, in order to improve output, a relatively large amount of supercharging is required. As a result, a large turbocharger is required, and the supercharging passage that supplies supercharging air to the engine has a large diameter, making the supercharging system larger and making it difficult to mount it on a vehicle. There was a problem that the driving loss was large as well as poor performance.

In view of this, the present invention provides an engine equipped with an oxygen concentration enrichment device as described above, by utilizing oxygen-rich air enriched by the oxygen concentration enrichment device as supercharging air. By increasing the oxygen concentration of the supercharging air, the supercharging effect per unit supercharging amount is increased, and the amount of supercharging can be reduced by that amount, thereby downsizing the supercharging system such as the supercharger and supercharging passage. The purpose is to achieve this goal.

For this purpose, the configuration of the present invention is such that, in an engine equipped with an oxygen concentration enrichment device as described above, a supercharging passage that supplies supercharging air to the engine is provided with an oxygen-enriched gas enriched by the oxygen concentration enrichment device. By providing a supercharging control device that controls the supply of air, oxygen-rich air is supplied to the engine as supercharging air.

Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, 1 is an engine, and 2 is a main intake passage whose one end opens to the atmosphere via an air cleaner 5 and the other end opens to the engine 1 and supplies normal air (atmosphere) to the engine 1 as intake air. Reference numeral 4 designates an exhaust passage that opens to the atmosphere at one end and opens to the engine 1 at the other end to discharge exhaust gas from the engine 1. The main intake passage 2 includes, in order from the upstream, 1 a main intake air amount detector 5 that detects the amount of intake air flowing through the main intake passage 2; a main throttle valve 6 that controls the amount of intake air flowing through the main intake passage 2; A main fuel injection valve 7 for injecting fuel into the main intake passage 2 is provided, and the main intake air amount detector 5 is connected to the main fuel injection valve 7 via a control circuit 8. Note that 9 is a main intake valve that opens and closes the opening of the main intake passage 2 to the engine 1, 10 is an exhaust valve, and 11 is a combustion chamber.

Further, an on-off valve 12 for controlling the opening and closing of the main intake passage 2 is disposed upstream of the main intake air amount detector 5 of the main intake passage 2, while an upstream end of the main intake passage is located upstream of the on-off valve 12. 2
An oxygen-rich air supply passage 1S is arranged in parallel with the main intake passage 2, and its downstream end opens into the main intake passage 2 downstream of the on-off valve 12 and upstream of the main intake air amount detector 5, bypassing the on-off valve 12. There is. In the middle of the oxygen-rich air supply passage 15, there is a cylindrical oxygen permeable membrane 15 housed in the case 14.
The oxygen permeable membrane 15 is disposed so that its outer circumference is communicated with the upstream side of the oxygen-rich air supply passage 15 and its inner circumference is communicated with the downstream side of the oxygen-rich air supply passage 15.
A feed pump 16 is provided in the upstream oxygen-rich air supply passage 15.
However, suction pumps 17 are interposed in each of the oxygen-rich air supply passages 16 downstream of the oxygen permeable membrane 15. Further, an oxygen concentration control valve 18 for controlling opening and closing of the oxygen-rich air supply passage 15 is disposed in the oxygen-rich air supply passage 16 downstream of the suction pump 17, and the oxygen concentration control valve 18 is connected to the oxygen-rich air supply passage 16 via a linkage 19. It is interlocked so that it opens and closes in the opposite direction to the on-off valve 12.

Furthermore, a nitrogen-rich air discharge passage 20 whose one end is open to the atmosphere is connected to the outer circumferential portion of the oxygen permeable membrane 15, and one end is connected to the suction pump 17 of the oxygen-rich air supply passage 16 for oxygen concentration opening control. An IJ-F passage 21 is provided which opens between the valve 18 and the other end opens in the middle of the nitrogen-rich air discharge passage 20, and the relief passage 2
1, there is a relief valve 2 that opens and closes the relief passage 21.
2 is interposed, and when the pressure in the oxygen-rich air supply passage 1S downstream of the suction pump 17 exceeds a predetermined pressure, the relief valve 22 opens and provides relief through the relief passage 21, reducing the pressure to a predetermined level. I try to keep it under pressure.

As described above, due to the pressure difference between the inner and outer circumferential parts of the oxygen permeable membrane 15 caused by the operation of the feed pump 16 and the suction pump 17, a large amount of oxygen is permeated in the air passing through the oxygen permeable membrane 15, and the oxygen content in the air is increased. The oxygen concentration enrichment device 25 is configured to increase the ratio and supply this oxygen-rich air to the engine 1 via the oxygen-rich air supply passage 16 when the oxygen concentration control valve 18 is opened.

As a feature of the present invention, 24 is a load detector that detects the engine load condition by the opening degree of the main throttle valve 6, and 25 is disposed immediately upstream of the main intake air amount detector 5 in the main intake passage 2. and the oxygen content ratio of the intake air (
Each of these detectors 24 and 25 is connected as an input to the control circuit 8. Reference numeral 26 denotes an oxygen concentration control device connected to the linkage 19 to control the operation of the on-off valve 12 and the oxygen concentration control valve 18, and the oxygen concentration control device 26 is connected to the control circuit 8.

Further, 27 is an IJ of the oxygen-rich air supply passage 15.
An auxiliary intake passage that branches from a position downstream of the opening of the leaf passage 21 and upstream of the oxygen concentration control device 18, and whose other end opens to the engine 1 and constitutes a supercharging passage that supplies oxygen-rich air as supercharging air to the engine 1. The auxiliary intake passage 2
Similarly to the main intake passage 2, auxiliary intake air amount detector 28 detects the intake air amount (supercharging amount) flowing through the auxiliary intake passage 27 in order from upstream; An auxiliary throttle valve 29 for controlling the amount (supercharging amount) and an auxiliary fuel injection valve '50 for injecting fuel into the auxiliary intake Jn path 27 are provided.

The auxiliary throttle valve 29 is linked to the main throttle valve 6 via a linkage 61, and remains closed until the main throttle valve 6 is opened to a predetermined opening degree (during low engine load). 6 is opened to a predetermined opening degree or more (when the engine is under high load).

Further, the auxiliary intake air amount detector 28 is connected to an auxiliary fuel injection valve 50 via a control circuit 8.

In addition, at the branch of the oxygen-rich air supply passage 16 with the auxiliary intake passage 27, the oxygen-rich air supply passage 15 upstream of the branch is connected to the oxygen-rich air supply passage 1 downstream of the branch.
5 or the auxiliary intake passage 27 is interposed, and when the switching valve 52 is operated, the oxygen-rich air supply passage 16 upstream of the branch portion and the auxiliary intake passage 27 are made to communicate with each other. I have to. On the other hand, an auxiliary intake valve '55 for opening and closing the auxiliary intake passage 27 is disposed at the opening of the auxiliary intake passage 27 to the engine 1.
A valve operating mechanism 65 is connected to the auxiliary intake valve 65 via a valve selector 64, and when the pulp selector 54 is activated, the valve operating mechanism 55 opens and closes the auxiliary intake valve 65. The switching valve 52 and pulp selector 64 are each connected to the control circuit 8.

As shown in FIG. 2, the control circuit 8 includes a basic injection amount determining circuit 56 that outputs a basic injection amount signal as a pulse signal based on each detection signal from the main and auxiliary intake air amount detectors 5 and 28. , the main and auxiliary fuel injection valves 7 and ! according to the basic injection amount signal from the basic injection amount determining circuit 66. 10, and when not receiving a high load signal from a second comparator 45 (described later) (during low load), only the main fuel injector 7 is driven, and when receiving a high load signal ( When the engine is under low load, the main fuel injection valve is provided with a fuel injection valve drive circuit 57 that drives both the fuel injection valves 7 and 60. When the engine is under high load, fuel is injected from the main and auxiliary fuel injection valves 7 and 60 in an amount corresponding to the amount of intake air in the main and auxiliary intake passages 2 and 27.

The control circuit 8 also includes a load state detection circuit that outputs a load state signal corresponding to the engine load state based on the detection signal from the direct load detector 24! +8, and a drive circuit 6 that outputs a drive signal for driving and controlling the oxygen concentration control device 26 in accordance with the load state signal from the load state detection circuit 68.
9, a reference value setting circuit 40 that sets a reference value signal corresponding to a target oxygen concentration according to the load state of the engine based on the load state signal from the load state detection circuit 38; a first comparator 41 that compares a reference value signal of 1 with a detection signal as a feedback signal from the oxygen concentration detector 25 and outputs a deviation signal corresponding to the deviation between the two; a correction circuit 42 that receives a signal, corrects the drive signal of the drive circuit 69, and outputs the corrected signal to the oxygen concentration control device 26; and the load detector 24.
A second comparator 46 is provided, which compares the detection signal from the engine with a reference value and outputs a high-load signal to the switching valve 32, the valve selector 54, and the fuel injection valve drive circuit 57 when the engine is under high load. There is.

The target oxygen concentration in the reference value setting circuit 40 is set to be high when the engine load is low, decrease as the engine load increases, and become the oxygen concentration of normal air (approximately 21 units) when the engine load increases. has been done. Therefore, when the load of the engine is low, the operation of the oxygen concentration control device 26 is controlled to fully close the on-off valve 12 and the oxygen concentration control valve 18 is activated.
By fully opening the switching valve 52 and the valve selector 34, the oxygen-rich air from the oxygen-rich air supply passage 15 is supplied to the engine 1 through the main intake passage 2, and the engine As the load increases, oxygen 1. The immersion level control device 26 moves the linkage 19 to the right in the figure, operates the on-off valve 12 from fully closed to open, and operates the oxygen concentration control valve 18 from fully open to closed, thereby controlling the flow of air from the oxygen-rich air supply passage 1!1. Oxygen-rich air is diluted with normal air from the main intake 4-way 2 and supplied to the engine 1, while when the engine is under high load, the oxygen concentration control device 26 fully opens the on-off valve 12 to control oxygen once. By fully opening and closing the valve 18, operating the switching valve 62 and valve selector S4 to communicate the oxygen-rich air supply passage 15 and the auxiliary intake passage 27, and opening and closing the auxiliary intake valve 6!1.
Normal air is supplied to the engine 1 through the main intake passage 2, and the suction pump 17 works as a supercharger to supply oxygen-rich air from the oxygen-rich air supply passage 13 to the engine 1 through the auxiliary intake passage 27. A supercharging control device 44 is configured to control supercharging.

Therefore, in the above embodiment, when the engine with relatively poor combustibility is under low load, the oxygen-rich air enriched by the oxygen concentration enrichment device 26 is routed through the main intake passage 2 by the operation control of the oxygen concentration control device 26. As a result, the oxygen concentration of the intake air increases,
Combustibility under low load can be improved.

On the other hand, when the engine is under high load, the oxygen concentration control device 26
Normal air is supplied to the engine 1 through the main intake passage 2 by the operation control of the oxygen concentration enrichment device 25.
The oxygen-rich air enriched by the supercharging control device 4
4, the engine 1 is supercharged via the auxiliary intake passage 27 serving as a supercharging passage, thereby increasing output and improving output performance under high engine loads.

At that time, since oxygen lynch air with a high oxygen concentration is used as supercharging air, the supercharging effect for improving output is high. The suction pump 17) may be small, and the supercharging passage (auxiliary intake passage 27) may be small in diameter, allowing the supercharging system to be downsized. Furthermore, this makes it possible to improve the on-vehicle compatibility of the supercharger/stem, reduce drive loss, and contribute to improvements in output and fuel efficiency.

Further, in the above embodiment, since the suction pump 17 of the oxygen concentration enrichment device 26 is also used as a supercharger, the above effects can be further exhibited.

It should be noted that the present invention is not limited to the above embodiments,
It also includes various other modifications. for example,
In the above embodiment, the oxygen concentration enrichment device 2!1 is based on an oxygen permeation method, but it is of course applicable to a device using a nitrogen adsorption method.

Furthermore, in the above embodiment, a so-called partial supercharging system was described in which oxygen-rich air was supercharged only when the engine was under high load, but a so-called full supercharging system in which oxygen-rich air was supercharged during full engine load Of course, it can also be applied to

As explained above, according to the present invention, in an engine equipped with an oxygen concentration enrichment device, oxygen-rich air enriched by the oxygen concentration enrichment device is supplied to the supercharging passage as supercharging air. Therefore, the supercharger and the supercharging system can be downsized, and it is possible to improve the on-vehicle compatibility of the supercharging system and reduce driving loss.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, with FIG. 1 being a general schematic diagram and FIG. 2 being a control port interlocking block diagram. DESCRIPTION OF SYMBOLS 1...Engine, 2...Main intake passage, 5...Main intake air amount detector, 6...Main throttle valve, 7...Main fuel injection valve, 8...Control circuit, 9...Main intake valve , 12...Opening/closing valve, 16...Oxygen-rich air supply passage, 15...Oxygen permeable membrane, 16...Feeding pump, 17...Suction pump, 18
...Oxygen concentration control valve, 25...Oxygen concentration enrichment device, 24
...Load detector, 25..Oxygen concentration detector, 26..Oxygen concentration control device, 27..Auxiliary intake passage, 28..Auxiliary intake air amount detector, 29..Auxiliary throttle valve, 5
0...Auxiliary fuel injection valve, 52...Switching valve, 66...
Auxiliary intake valve, 64... Valve selector, 55... Valve mechanism, 66... Basic injection soft decision circuit, 57... Fuel injection valve drive circuit, 58... Load state detection circuit, 59... Drive circuit, 40 ...Reference value setting circuit, 41...First comparator, 4
2. Correction circuit, 45. Second comparator, 44. Supercharging control device.

Claims (1)

[Claims] fil In an engine equipped with an oxygen concentration enrichment device that increases the oxygen content ratio in air, oxygen-rich air enriched by the oxygen concentration enrichment device is supplied to a supercharging passage that supplies supercharging air to the engine. 1. An engine intake system characterized by being provided with a supercharging control device that performs control as follows.