JPS58220947A - Exhaust gas recycle control device - Google Patents

Abstract

PURPOSE:To check a sudden change in pressure inside a pressure regulating chamber as well as to improve the responsiveness of a control device in time of acceleration, by leading a signal of suction pressure into the pressure regulating chamber of a modulator outputting the said signal of suction pressure to an exhaust gas recycle control valve via a suction pressure control valve having a throttle. CONSTITUTION:A modulator 20 regulates the suction pressure of a suction pressure port 16 being open to the modicum opening position of a throttle valve 15 according to a pressure difference between a pressure regulating chamber 23 and an exhaust pressure chamber 4 and outputs this suction pressure to an exhaust gas recycle control valve 11 as a signal of suction pressure via a signal pressure passage 32. At the pressure regulating chamber 23, the signal of suction pressure in the signal pressure passage 32 is designed so as to be led from a suction pressure control port 10 together with atmospheric pressure out of an atmosphere lead-in hole 2 via a suction pressure control valve 18 consisting of an on-off valve 41 to be opened when the suction pressure of a suction pressure port 42 is below the setting value and a check valve 18-1 and a throttle valve 18-2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exhaust gas recirculation control device used for controlling exhaust gas from an internal combustion engine.

FIGS. 1 and 2 show an exhaust gas recirculation control device studied by the present inventor. In this device, the signal negative pressure of the output boat 8 of the modulator 20 becomes as shown by the broken line A in FIG. It was confirmed that the rise of negative pressure after up-acceleration was slow.

Therefore, in the devices shown in FIGS. 1 and 2, the amount of exhaust gas recirculated immediately after acceleration is small, and a problem has been recognized that a large amount of NOx is likely to be generated at this time. In addition, it was also recognized that the amount of exhaust gas recirculation tends to become unstable, and the operation of the internal combustion engine also tends to become unstable.

As a result of various studies conducted by the inventors, it was concluded that the reason for this is that the pressure within the pressure regulating chamber 23 of the modulator 20 is unstable due to a sudden change in the operating condition of the internal combustion engine.

The present invention was devised based on the above study results, and its purpose is to attenuate sudden changes in the signal negative pressure introduced into the pressure regulating chamber 23 of the modulator 20 and to perform good exhaust gas recirculation control. shall be.

An embodiment of the present invention will be described based on the drawings. The modulator 20 guides the negative pressure generated in the negative pressure source boat 16 , which opens at a small opening position of the throttle valve 15 , to the negative pressure control chamber 1 via the negative pressure input boat 9 . Then, the exhaust pressure in the pressure chamber 22 of the exhaust gas recirculation control valve 11 is guided to the exhaust pressure chamber 4 through the exhaust pressure orifice 5, and the difference in pressure between the exhaust pressure chamber 4 and the pressure adjustment chamber 23 causes the exhaust pressure in the pressure chamber 22 of the exhaust gas recirculation control valve 11 to be introduced into the exhaust pressure chamber 5. control valve 6.

Therefore, the gap between the seat valve 6 and the seat throttle 7 is such that the atmosphere input from the atmosphere guide hole 2 and the negative pressure introduced into the human-powered boat 9 from the negative pressure source 16 are regulated. Then, a signal pressure is created in the negative pressure control chamber l.
The pressure generated in the pressure regulating chamber 23 (the negative pressure regulated by the seat valve 6 and the throttle 7) is taken out from the negative pressure control boat 10 and sent to the output boat 8 through passages 30 and 31.
The signal is introduced into the pressure passage 32 where the signal is outputted. An on-off valve 41 that is opened and closed by the intake pipe negative pressure taken out from the intake manifold negative pressure source boat 42 is disposed in the middle of this passage 30.31.
is intermittent. Therefore, the signal pressure output from the output boat 8 can be adjusted as appropriate based on the intake pipe negative pressure from the negative pressure source boat 42.

Moreover, in this example, there is a throttle 18-2 in the middle of the passage 30.
A negative pressure control valve jlB including a one-way valve 18-1 is provided. Therefore, even if the on-off valve 41 suddenly opens and closes, the negative pressure control boat 10
3) to prevent the signal pressure from the output boat 8 from becoming unstable due to the pressure. This adjusted negative pressure becomes a signal negative pressure to operate the exhaust gas recirculation control device valve 11. In addition, when it is cold, the exhaust recirculation control device valve 11
The negative pressure that activates the air conditioner is released through a check valve 43, a water temperature sensing valve 44, and a pipe leading to an atmospheric boat 45. When the temperature is warm, negative pressure from the intake manifold negative pressure source boat 42 is applied to -C through the water temperature sensing valve 24.
The check valve f, 43 is reached and the check valve 43 is closed.
The configuration is such that the negative pressure that operates the C exhaust recirculation control device valve 11 is not released.

Next, the operation of the above-mentioned component device will be explained. When the internal combustion engine is in idle cylinder operation and the opening degree of the throttle valve 15 is lower than the throttle valve small opening position negative pressure source boat 16, almost no negative pressure is applied to the throttle valve small opening position negative pressure source boat 16. Therefore, there is almost no negative pressure in the negative pressure output boat 8, and the exhaust gas recirculation control device valve 11 does not open, so that exhaust gas recirculation is not performed.

Next, when the internal combustion engine is operated under medium load, the opening degree of the thrower (4) tor valve 15 becomes 10 from the negative pressure source boat 16. At this time, from the set negative pressure of the on-off valve 41, the intake manifold negative pressure source boat 42
If the suction 1 negative pressure guided from the
0.31 is blocked. As a result, the signal negative pressure from the negative pressure output boat 8 directly operates the exhaust gas recirculation control device valve 11 to perform exhaust gas recirculation.

On the other hand, if the trachea negative pressure led from the intake manifold negative pressure source boat 42 is lower than the set negative pressure of the on-off valve 41, the on-off valve 41 brings the passages 30 and 31 into communication. At this time as well, the negative pressure in the negative pressure control chamber 1 to which the negative pressure from the negative pressure source board 16 is guided is adjusted to a level, and the signal negative pressure of the negative pressure output port 8 is obtained. However, this signal negative pressure is introduced into the pressure regulating chamber 23 from the negative pressure control boat 10 via the opening/closing valve f, 41. Conversely, the atmosphere from the atmosphere introduction hole 2 flows from the pressure regulation chamber 23 to the passage 30°31.
The signal is introduced into the negative pressure via. Therefore, the negative pressure applied to the exhaust recirculation control device valve 11 becomes low (5), and the opening pressure of the exhaust recirculation control device valve 11 causes the signal negative pressure path 32, the air enters the negative pressure control valve 18.
-2 limits the flow rate. Therefore, sudden fluctuations in the signal negative pressure due to the opening/closing operation of the on-off valve 41 are prevented, and stable exhaust gas recirculation is performed.

Particularly in this example, the action of the throttle 18-2 prevents the pressure within the pressure regulating chamber 23 from changing suddenly.

Therefore, the pressure in the negative pressure control chamber 1, which is regulated by the internal pressure of the pressure regulating chamber 23 and the negative pressure introduced from the human-powered boat 9, is also stable, and as a result, the negative pressure signal from the negative pressure output boat 8 is is also stable. The solid line in FIG. 3 is an explanatory diagram showing the relationship between the negative pressure output □ negative pressure signal from the boat 8 and the acceleration state (vehicle speed) of the internal combustion engine. As is clear from this diagram, the negative pressure control valve 18 If provided, the followability of the signal negative pressure with respect to acceleration will be greatly improved.

Note that in the above example, the passage 30. ' 3 ■ Opening/closing* 41, which is installed in the middle of the valve, directly responds to the intake pipe negative pressure from the intake manifold negative pressure source 42, but this is controlled by the negative pressure sensing switch 40 and the solenoid as shown in Figure 1. It may be replaced with the valve 39. That is, if the intake pipe negative pressure is above a predetermined value, the negative pressure sensing switch 40 is closed, a signal current is applied to the solenoid valve 39, and the solenoid valve 39 closes the passage 30.
．． 31 is cut off. Conversely, if the intake pipe negative pressure is lower than the predetermined value, no current flows to the solenoid valve 39 and the passage 30°3
1 is conductive.

By appropriately selecting this set value, it is possible to freely select the interruption of exhaust gas recirculation for each vehicle speed using the intake pipe negative pressure as a medium.

Further, as shown in FIG. 5, the device of the present invention connects the passage 30 communicating with the negative pressure control boat 10 to the negative pressure output port
It may be directly connected to the signal negative pressure passage 32 that communicates with the signal negative pressure passage 32 . Even in such piping, by arranging the negative pressure control valve 18 in the middle of the passage 30, it is possible to improve the followability of the signal negative pressure from the positive pressure output boat 8 to the vehicle speed of the internal combustion engine. . (7) Figure 6 shows the effect of the negative pressure control valve 18 in the device shown in Figure 5.If the negative pressure control valve 18 is provided,
It is confirmed that the followability is improved compared to the one without (A in the figure).

As explained above, in the device of the present invention, the passage leading to the pressure regulating chamber of the modulator is connected to the signal negative pressure passage leading to the negative pressure output port, and the negative pressure control valve 18 having a throttle is disposed in the middle of the passage. Therefore, rapid fluctuations in the amount of air flowing through the passage 1 can be suppressed. Therefore, the device of the present invention has an excellent effect in that the signal negative pressure introduced into the exhaust gas recirculation control valve can be made to respond favorably to the acceleration state of the internal combustion engine.

[Brief explanation of drawings]

FIGS. 1 and 2 are block diagrams showing an exhaust gas recirculation control device applied to the present invention, FIG. 3 is an explanatory diagram for explaining the effects of the present invention, and FIG. 4 is a block diagram showing an example of the device of the present invention. , 5th
The figure does not show another example of the apparatus of the present invention, but is a block diagram, and FIG. 6 is an explanatory diagram for explaining the effect of the apparatus shown in FIG. 8... Negative pressure output boat, 10... Negative pressure control (8), 11... Exhaust recirculation control valve, 20... Modulator, 1B... Negative pressure control valve. Representative Patent Attorney Takashi Okabe (9)

Claims (1)

[Claims] An exhaust recirculation control valve disposed in the middle of the exhaust recirculation passage to control exhaust gas recirculation, a modulator that outputs a signal negative pressure to the exhaust recirculation control valve via a signal passage, a pressure regulating chamber of the modulator, and the signal passage. An exhaust gas recirculation control device comprising a passage connecting the two, and a negative pressure control valve having a throttle disposed in the passage.