JPS60173362A - Suction device for diesel engine - Google Patents

Abstract

PURPOSE:To reduce smoke as well as to aim at improvements in the output of power, by installing a bypass passage, an oxygen rich film and an air pump in a suction passage of a Diesel engine, while controlling the air pump according to output of a smoke sensor. CONSTITUTION:A bypass passage 6 is installed in a suction passage of a Diesel engine 1, while an oxygen rich film and an air pump 8 are installed in this bypass passage 6. A control unit 15 inputting an output signal out of a smoke sensor 13 installed in an exhaust passage 3 drives the air pump 8 at a time when output of the smoke sensor 13 is above the specified value, and feeds the oxygen rich air run past the oxygen rich film 9 to a suction pipe 5, improving the engine output without raising the smoke content. A nitrogen rich component is eliminated from the exhaust passage 3 via a solenoid valve 12.

Description

[Detailed description of the invention] Technical field The present invention relates to an intake system for a diesel engine.

In conventional diesel engines, unburned hydrocarbon components and the like are discharged as smoke, so the amount of fuel supplied during high loads has to be restricted, which has become a bottleneck in the direction of diesel engine output. On the other hand, the idea of providing an oxygen-enriching membrane in the intake system of an engine is disclosed in JP-A No. 58-58-1, for example.
This method is disclosed in Japanese Patent Application Laid-open No. 38239 and Japanese Patent Application Laid-open No. 155268/1983. These oxygen-enriched membranes are placed in the bypass intake passage, and by detecting misfire or idle rotation, oxygen-rich air that has passed through the oxygen-enriched membrane is selectively supplied to the engine.

OBJECTS OF THE INVENTION An object of the present invention is to use an oxygen enrichment membrane in a diesel engine, thereby reducing diesel engine smoke and increasing engine power.

Structure of the Invention According to the present invention, a bypass passage is connected to the intake passage, and an oxygen enrichment membrane and an air pump are arranged in the bypass passage,
There is provided an intake system for a diesel engine in which the air pump is controlled based on the output of a smoke sensor provided in an exhaust passage.

DESCRIPTION OF EMBODIMENTS A diesel engine main body 1 shown in FIG. 1 includes a known intake manifold 2 and an exhaust manifold 3.
is connected. An intake pipe 5 extending from an air cleaner 4 is connected to the intake manifold 2, and a bypass pipe 6 extending from the air cleaner 4 is connected to the intake pipe 5.

An oxygen enrichment membrane case 7 and an air pump 8 are arranged in the bypass pipe 6. The order of the oxygen enrichment membrane case 7 and the air pump 8 may be reversed. Several oxygen enrichment membranes 9 are arranged across the substantially center of the oxygen enrichment membrane case.

The oxygen enrichment membrane 9 is a gas separation membrane that can selectively permeate oxygen in the air, and may be made of multiple layers of silicone rubber membranes or the like or organic polymer fibers such as polyvinyl alcohol.

The atmosphere side space of the oxygen-enriching membrane case 7 is communicated with the exhaust manifold 3 through the path Iillog. A reed valve 11 and a solenoid valve 12 are arranged in the passage 10 as check valves. Further, a smoke sensor 13 is attached to the exhaust manifold 3, and its output is sent to the detection device 1.
4 to a control device (computer) 15, which controls a pump control section 16 and a solenoid valve 12. The details of the smoke sensor 13 are shown in FIG. 2, and it consists of a light emitter 13a and a light receiver 13b that are mounted opposite to each other on the pipe section of the exhaust manifold 3, and detects the concentration of smoke passing through these optical paths. It is something to do. The smoke sensor may also be one that detects the carbon oxide concentration in exhaust gas.

In the above configuration, when the smoke sensor 3 is outputting an output smaller than a predetermined level, the solenoid valve 12 is closed and the air pump 8 is stopped. When the smoke sensor 13 outputs an output above a predetermined level, the air pump 8 is driven, and the oxygen-rich air that has passed through the oxygen enrichment membrane 9 is sent to the intake pipe 5, from which it is supplied to the engine combustion chamber. be done. Therefore, the air sucked into the engine combustion chamber at this time has a higher oxygen content than normal, so even if the amount of fuel is increased, the combustion condition will not deteriorate, and therefore the engine output can be improved without increasing the smoke concentration. .

The solenoid valve 12 is opened appropriately depending on the operating time and rotational speed of the air pump 8, and the nitrogen-enriched components are removed from the exhaust manifold 3 along with the exhaust pulsation.

In the embodiment shown in FIG. 4, the oxygen enrichment membrane 9 is annularly attached to the case 7, and the solenoid valve 12 in FIG. 1 is omitted. Even without a solenoid valve, the suction force of the air pump 8 exceeds the suction force of the exhaust pulsation, and the riet valve 11 is in a closed state. When the nitrogen component increases on the outer periphery of the oxygen enrichment membrane 9, the suction force of the air pump 8 becomes weaker, and the riet valve 1 is opened to remove the nitrogen component. Other operations are similar to the jth embodiment.

As described in detail, according to the present invention, engine output can be improved while reducing smoke.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a diesel engine according to the invention, FIG.
3 is a detailed view of the exhaust manifold portion of FIG. 1, and FIG. 4 is a schematic view of another embodiment. 5... Intake pipe, 6... Bypass pipe, 8... Air pump, 9... Oxygen enrichment membrane, 1o... Nitrogen component removal passage, 13... Smoke sensor. Patent applicant Toyota, Jidosha Co., Ltd. Patent application agent Akira Aoki Patent attorney Kazuyuki Nishidate Patent attorney Kyosuke Tsuchiyama Patent attorney Akira Yamaguchi Patent attorney Masaya Nishiyama 40th

Claims (1)

[Claims] A bypass passage is connected to an intake passage of a diesel engine, an oxygen enrichment membrane and an air pump are disposed in the bypass passage, and the air pump is controlled based on the output of a smoke sensor provided in an exhaust passage. intake system of a diesel engine.