JPS6037307B2 - 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 connected to an exhaust recirculation passage formed between an exhaust circuit of an engine and an intake passage of the engine. A negative pressure-responsive recirculation control valve having a 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. The air passage which opens to the atmosphere through the orifice in the air passage is branched, and a negative pressure-responsive air control valve having a negative pressure chamber selected as the negative pressure passage is intervened in the air passage, and the orifice in the air passage is further connected to the air passage. and a negative pressure responsive regulating valve having a negative pressure chamber extending in the negative pressure air between the air control valve and the negative pressure air, the regulating valve causing the negative pressure in the negative pressure passage to leak; In this way, a system in which the amount of exhaust gas recirculation is made approximately proportional to the intake air amount of the engine was proposed as Tokuko Sho 53-69858 (Tokko Sho 54-160927), but in this case, its operating characteristics were It is preferable that the pressure can be adjusted depending on the intake negative pressure and other factors.

The object of the present invention is to obtain a device that meets the above requirements, and in which the intake air passage is provided in the exhaust gas recirculation passage formed between the exhaust passage of the engine and the engine exhaust passage. A negative pressure-responsive circulation control valve having a negative pressure chamber extending into the negative pressure passage extending from the negative pressure outlet near the throttle valve is inserted, and the intake passage is connected to the intake passage from the downstream side of the throttle valve. An air passage opening to the atmosphere is branched through an orifice having an area that is a certain area ratio to the area of the venturi portion of the venturi, and a negative pressure responsive air control valve that is connected to the negative pressure passage is intervened therein. Furthermore, a negative pressure-responsive regulating valve having a negative pressure chamber arranged in a negative pressure space between the orifice in the air passage and the air control valve is provided so that the negative pressure in the negative pressure passage described above is controlled by the regulating valve. In the case of the type that leaks water, the orifice is configured as a negative pressure responsive type or other variable restrictor having a negative pressure chamber extending into the negative pressure passage.

Embodiments of the present invention will be described with reference to attached drawings.

In the drawing, 1 is an engine, 2 is an exhaust passage of the engine 1, and 3 is an engine.
indicates 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, and an exhaust recirculation passage 4 is formed in the intake passage 3 near the throttle valve 5, that is, the position where the throttle valve is closed. A negative pressure-responsive recirculation control valve 9 having a negative pressure chamber 8 extending into a negative pressure passage 7 extending from a negative pressure outlet 6 on the more generally upstream side 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 air control valve which branches an air passage 13 that is closed to the atmosphere from the downstream side of the throttle valve 5 described above through an orifice 12, and has a negative pressure chamber 14 in the negative pressure passage 7 described above. 15 to intervene. 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 negative 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 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 2.
2 is closed, but if the negative pressure in the negative pressure chamber 20 increases, it is configured to move back against the spring 24 and open the hole 22 accordingly. In this case, venturi negative pressure is applied to the interior of the chamber 25 in front of the valve 21 through the passage 28 to the negative pressure outlet 27 of the venturi portion 26 in the intake passage 3. Configured to respond by differential pressure. 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 increases.
5 is opened, and the air passage 13 is opened by opening the control valve 15.
Since the negative pressure in the negative pressure space 18 increases, the diaphragm 23 of the regulating valve 21 opens the hole 22 between the venturi part 26 and the negative pressure chamber 14 to transfer the low negative pressure in the venturi part 26 to the negative pressure chamber 14. , the control valve 15 is immediately closed, and by repeating this, feedback control is performed so that the closing area of the control valve 15 is maintained at a constant ratio with the entrance area of the throttle valve 5. Venturi part 2 of
6 and an orifice 12 having a constant area ratio
3 is controlled at 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, also depends on the intake passage 3.
accurately controlled in proportion to the flow rate. Although the above is not particularly different from the conventional one, according to the present invention, the orifice 12 at the upstream end of the air passage 13 is configured as a variable throttle. In the illustrated example, this is designed to respond to intake negative pressure, that is, extends from a diaphragm 30 on the front side of the negative pressure chamber 29 connected to the negative pressure passage 7 described above. To explain its operation, consider, for example, the case where the orifice 12 of the variable throttle moves upward in the drawing as the intake negative pressure increases, and the degree of throttle increases.The air flow rate in the air passage 13 decreases. The negative pressure in the negative pressure space 18 increases, and thus the regulating valve 21 becomes open due to the increased negative pressure in the negative pressure chamber 20, increasing the degree of leakage.

Therefore, the inside of the negative pressure passage 7 exists at a relatively small negative pressure, and the recirculation control valve 9 has a small negative pressure applied to its negative pressure chamber 8 and closes, thus reducing the amount of exhaust recirculation. Ru. To summarize, the amount of exhaust gas recirculation is adjusted by adjusting the variable throttle. In this way, according to the present invention, the orifice at the upstream end of the air passage is a variable throttle, and the operating characteristics are corrected by adjusting the throttle.For example, it is advantageous to adjust the exhaust recirculation amount according to the intake negative pressure. The structure is simple, and the effect can be obtained at low cost.

[Brief explanation of the drawing]

The drawing is a diagram of an example of the device of the present invention. 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, 2
0... Negative pressure chamber, 21... Regulating valve.

Claims (1)

[Claims] 1. An exhaust gas recirculation passage formed between an engine exhaust passage and an intake passage of the engine has a negative pressure chamber connected to a negative pressure passage extending from a negative pressure outlet near the throttle valve of the intake passage. A negative pressure responsive reflux control valve is inserted, and an air passage opens to the atmosphere from the downstream side of the throttle valve to 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 intervened, and the negative pressure between the orifice in the air passage and the air control valve is In a device that is equipped with a negative pressure-responsive regulating valve having a negative pressure chamber communicating with the space, and in which the negative pressure in the negative pressure passage is leaked by the regulating valve, the orifice is connected to the negative pressure passage. An exhaust gas recirculation device for an engine comprising a negative pressure responsive variable throttle having a negative pressure chamber.