JPS6037305B2 - Exhaust recirculation device in engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exhaust gas recirculation device for automobiles and other engines.

The applicant of the present application has previously proposed that in this type of device, a negative pressure outlet near a throttle valve in the intake passage is formed between an exhaust passage of an engine and an intake passage of the engine, and is inserted into an exhaust gas recirculation passage. A negative pressure-responsive reflux control valve having a negative pressure chamber that extends into the negative pressure passage is intervened, and an area of a certain area ratio with the area of the venturi portion of the intake passage is adjusted from the downstream side of the throttle valve of the intake passage. An air passage closed to the atmosphere through an orifice in the air passage is branched, and a negative pressure-responsive air control valve having a pressure chamber extending into the negative pressure passage is intervened in the air passage, and the orifice in the air passage is further connected to the air passage. A negative pressure-responsive regulating valve having a negative pressure chamber disposed in the negative pressure air is provided between the air control valve and the negative pressure in the negative pressure passage is leaked by the regulating valve. A special model was developed in 1974 that made the amount of exhaust gas recirculation approximately proportional to the amount of intake air of the engine.
No. 69858 (Japanese Patent Application No. 160927/1983), in this case, the concentration of the air-fuel mixture should be increased to some extent in order to eliminate shock during operation, especially the shock that tends to occur at the boundary between stopping and starting exhaust gas recirculation. There are demands to be made.

It is an object of the present invention to obtain a device that meets the above requirements. A negative pressure-responsive circulation control valve having a negative pressure chamber extending into a negative pressure passage extending from a negative pressure outlet near the throttle valve is inserted, and a venturi of the intake passage is inserted into the intake passage from the downstream side of the throttle valve. A negative pressure-responsive air control valve having a negative pressure chamber branching off from an air passage that opens to the atmosphere through an orifice having an area that is a certain area ratio to the area of the part, and extending into the negative pressure passage mentioned above. and a negative pressure-responsive regulating valve having a negative pressure chamber that extends into the negative pressure space between the orifice in the air circuit and the air control valve. In a type that allows negative pressure in the passage to leak, a fuel passage leading to an external fuel supply source is closed in the air passage upstream of the air control valve.

Embodiments of the present invention will be described with reference to the attached drawings. In the drawings, 1 is an engine, 2 is an exhaust passage of the engine 1, and 3 is an intake passage of the engine 1. An exhaust gas recirculation passage 4 is formed between the exhaust passage 2 and the intake passage 3. A negative pressure-responsive recirculation control valve 9 having a negative pressure chamber 8 connected to a negative pressure passage 7 extending from a negative pressure outlet 6 near the throttle valve 5 of the intake channel 3 is intervened.

The valve 9 is always pushed by the spring 11 through the diaphragm 10 and remains closed, and according to the negative pressure in the negative pressure chamber 8, the spring 1
It is configured to open against 1. The above-mentioned intake passage 3
A negative pressure responsive type air control having an air passage 13 which branches off from the downstream side of the throttle valve 5 mentioned above and closes to the atmosphere via an orifice 12, and has a negative pressure chamber 14 connected to the negative pressure path 7 mentioned above. Valve 15 is intervened. Similar to the valve 9 described above, the valve 15 is normally closed by the spring 17 via the diaphragm 16, and opens against the spring 17 due to the negative pressure in the negative pressure chamber 14. Constructed as possible. Furthermore, a negative pressure responsive regulating valve 21 having a pressure chamber 20 extending through a passage 19 into the negative pressure space 18 between the orifice 12 in the air passage 13 and the control valve 15 is provided, The valve 21 is configured to leak the negative pressure in the negative pressure passage 7 described above.

That is, the valve 21 is provided facing the IJ-leak hole 22 extending from the negative pressure passage 7 described above, and is normally pressed by a spring 24 via a diaphragm 23 to close the leak hole 22. However, according to the increase in the negative pressure in the negative pressure chamber 20,
In response, it is configured to move back against the spring 24 to open the hole 22. In this case, the chamber 25 in front of the valve 21
The inside of the intake passage 3 is connected to the negative pressure outlet 27 of the venturi portion 26 in the intake passage 3 through a passage 28, so that a venturi negative pressure is applied thereto, and the intake passage 3 is configured to react based on the differential pressure therebetween. Therefore, when the throttle valve 5 is opened near the upstream side of the negative pressure outlet 6, the negative pressure in the intake passage in the vicinity becomes large, and the negative pressure in the negative pressure chamber 14 increases, causing the control valve to open. 15
is opened, and the negative pressure in the negative pressure space 18 of the air passage 13 increases due to the opening of the control valve I5.
The control valve 15 is immediately closed by opening the J-hole 22 and introducing the low negative pressure of the venturi section 26 into the negative pressure chamber 14. By repeating this process, the entrance area of the control valve 15 becomes the opening area of the throttle valve 5. The flow rate of the air passage 13 having the orifice 12 having a constant area ratio with the venturi portion 26 of the intake passage 3 is controlled to be a constant ratio with the flow rate of the intake passage 3. The flow rate of the recirculation control valve 9, which is controlled by using the operating negative pressure of the negative pressure chamber 14 of the control valve 15 of the air passage 13 as an output, is also accurately controlled in proportion to the flow rate of the intake passage 3. Although the above is not particularly different from the conventional one, according to the present invention, in the above,
A fuel passage 30 extending into the above-mentioned air passage 13 and into a fuel tank or other fuel supply source 29 above the air passage 13 is closed, so that the air conducted through the passage 13 is accompanied by a corresponding amount of fuel. I made it possible to do so.

Thus, the concentration of the air-fuel mixture introduced into the engine 1 via the intake passage 3 is increased to some extent by this additional fuel, which reduces shocks that are likely to occur during driving, especially when exhaust gas recirculation stops and starts. This has an advantageous effect on reducing shocks that tend to occur at boundaries. Note that the entrance point of the fuel passage 30 can be arbitrarily set as the orifice 12 at the upstream end as shown by the solid line, or downstream thereof. In this way, according to the present invention, additional fuel is guided through the air passage, which is advantageous in reducing the shock that is likely to occur due to an increase in the concentration of the air-fuel mixture, and the amount of fuel is introduced through the air passage. It has the effect of being automatically controlled in proportion to the amount of air introduced.

[Brief explanation of the drawing]

The drawing is a diagram of an example of the device of the present invention. DESCRIPTION OF SYMBOLS 1... Engine, 2... Exhaust passage, 3... Intake passage, 4... Exhaust recirculation passage, 5... Throttle valve, 6... Negative pressure outlet, 7... Negative pressure passage, 8... Negative pressure chamber, 9... Reflux control valve, 12... Orifice, 13... Air passage,
14... Negative pressure chamber, 15... Air control valve, 18...
Negative pressure space, 20...Negative pressure chamber, 21...Adjusting valve, 29
...Fuel supply source, 30...Fuel passage.

Claims (1)

[Claims] 1. In the exhaust gas recirculation passage formed between the exhaust passage of the engine and the intake passage of the engine, there is provided a negative pressure chamber connected to the negative pressure passage extending from the negative pressure outlet near the throttle valve of the intake passage. A negative pressure-responsive reflux control valve is inserted into the intake passage, and air is opened to the atmosphere from the downstream side of the throttle valve into the intake passage through an orifice having an area that is a certain area ratio to the area of the vent lily portion of the intake passage. A negative pressure-responsive air control valve having a negative pressure chamber connected to the above-mentioned negative pressure passage is interposed by branching the passage, and a negative pressure responsive air control valve is inserted between the orifice in the air passage and the air control valve. A negative pressure-responsive regulating valve having a negative pressure chamber connected to a pressure space is provided, and the regulating valve causes the negative pressure in the negative pressure passage to leak, and the air control valve has a negative pressure chamber on the upstream side of the air control valve. An exhaust gas recirculation device for an engine, which has a fuel passage connected to an external fuel supply source opened in the air passage.