JP3366558B2 - Exhaust gas recirculation system for internal combustion engine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas of an internal combustion engine which reduces intake pulsation in accordance with the operating condition of the engine and enables the optimal control of the EGR rate. It relates to a recirculation device. 2. Description of the Related Art A supercharger comprising a compressor rotated by an exhaust turbine, a first exhaust cam for opening an exhaust valve on a camshaft during an exhaust stroke, and a discharge valve for a certain period during an intake stroke A second exhaust cam that opens the valve is provided,
As shown in FIG. 2, an internal combustion engine having an exhaust gas recirculation device that introduces a part of exhaust gas into a cylinder by a pressure difference between intake and exhaust while the exhaust valve is simultaneously opened by the intake valve and the second exhaust cam. Institutions have realized. In an internal combustion engine having the above-mentioned conventional exhaust gas recirculation device, as an EGR amount control means, intake pulsation is increased in a medium speed range, and at the same time, a supercharger is set to a high pressure. Although the EGR amount is increased by narrowing to the ratio side, the EGR rate becomes excessive during acceleration as shown in FIG.
There was a problem that black smoke emission increased. [0004] An object of the present invention is to solve the above-mentioned conventional problems by reducing intake pulsation in accordance with the operating condition of an engine and controlling the EGR rate to the same to reduce the emission of black smoke. It is an object of the present invention to provide an exhaust gas recirculation device for an internal combustion engine. [0005] In order to achieve the above object, the present invention provides a turbocharger comprising a compressor which is rotated by an exhaust turbine, and an opening of an exhaust valve on a camshaft during an exhaust stroke. A double exhaust cam that opens the exhaust valve only during a certain period during the intake stroke; and a suction valve that simultaneously opens the exhaust valve by the intake valve and the second exhaust cam. In an internal combustion engine equipped with an exhaust gas recirculation device that introduces a part of exhaust gas into a cylinder by a pressure difference of exhaust gas, in an inertia supercharging pipe connected to an intake manifold ,
Open and close the communication port provided in the central partition in the pipe
An intake pulsation control device equipped with a valve
Based on the operating conditions of the engine based on the detection signals of the rotation speed, the accelerator opening and the boost pressure, the controller performs
The intake pulsation control device is controlled to optimally control the exhaust gas recirculation rate in accordance with the operating condition of the engine. Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a cylinder, 2 is a piston, 3 is an intake valve, and 4 is an exhaust valve. The intake valve 3
The exhaust valve 4 has an exhaust manifold 7 on the exhaust valve 4 side. A supercharger 8 including an exhaust turbine 8a and a compressor 8b is connected to the exhaust manifold 7, and exhaust gas is discharged from the exhaust turbine 8a through an exhaust pipe 9, and the compressor 8
The intake air is cooled by the intercooler 11 through the intake pipe 10 and introduced into the cylinder 1 from the intake manifold 12 by b. The camshaft 5 includes a first exhaust cam 6a for opening the exhaust valve 4 during the exhaust stroke and a second exhaust cam 6b for opening the exhaust valve 4 for a certain period during the intake stroke. A cam 6 is provided, and a part of the exhaust gas is introduced into the cylinder 1 by a pressure difference between intake and exhaust while the exhaust valve 4 is simultaneously opened by the intake valve 3 and the second exhaust cam 6b. The present invention relates to an internal combustion engine provided with an exhaust gas recirculation device having the above-described structure, and to an intake manifold 1
2 is connected to the inertia supercharging pipe 13 and the intake pulsation control device 14
And a controller 1 based on the operating condition of the engine.
5, the intake pulsation control device 14 is controlled. The inertial supercharging pipe 13 has an intake pipe length obtained by dividing the center of the pipe into two in the longitudinal direction by a partition 13a, and the intake pulsation control device 14 opens and closes a communication port 13b provided in the partition 13a. Butterfly valve 1
4a. The controller 15 controls the intake pulsation control device 14 by inputting detection signals of the engine speed Ne, the accelerator opening and the boost pressure. Since the present invention is configured as described above, the communication port 13b provided in the partition wall 13a of the inertial supercharging pipe 13 is closed by the butterfly valve 14a of the intake pulsation control device 14 in the high speed range of the engine. And As a result, the substantial intake pipe length of the inertial supercharging pipe 13 is increased, intake pulsation is increased, the EGR rate is increased, and NOx is reduced. However, during the acceleration period of the engine from the low and middle speed ranges, the controller 15 controls the inertia by the butterfly valve 14a of the intake pulsation control device 14 based on the detection signals of the engine speed Ne, the accelerator opening and the boost pressure. The opening of the communication port 13b provided in the partition 13a of the supercharging pipe 13 is controlled. As a result, the substantial intake pipe length of the inertial supercharging pipe 13 is shortened, the intake pulsation is reduced, the EGR rate is reduced, and an increase in black smoke emission is prevented. As described above, according to the present invention, EG
In an internal combustion engine equipped with an R device ,
Bar that opens and closes the communication port provided in the central partition wall in the pipe.
An intake pulsation control device equipped with a lube
Number, accelerator opening and boost pressure detection signals
Controlling the intake air pulsation control device based on the operation condition of the gin
As a result, it is possible to control the EGR rate to an optimum value according to the operating condition of the engine with a simple structure, to reduce NOx at high speeds and to discharge black smoke during acceleration from low and medium speed ranges. Has a special effect of reducing

[Brief description of the drawings] FIG. 1 is a configuration diagram of the apparatus of the present invention. FIG. 2 is a view showing an intake / exhaust valve lift by a two-mount exhaust cam. FIG. 3 is a diagram showing an EGR rate by a conventional EGR device. [Explanation of symbols] 1 cylinder 2 piston 3 Intake valve 4 Exhaust valve 5 camshaft 6 cams 6a First exhaust cam 6b Second exhaust cam 7 Exhaust manifold 8 Supercharger 8a Exhaust turbine 8b compressor 9 Exhaust pipe 10 Intake pipe 11 Intercooler 12 Intake manifold 13 Inertia supercharger 13a partition 13b Communication port 14 Intake pulsation control device 14a butterfly valve 15 Controller

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ Identification code FI F02D 43/00 F02D 43/00 301N F02M 25/07 550 F02M 25/07 550F 550R (58) Field surveyed (Int. Cl. ⁷ , DB name) F02D 13/02 F02B 27/00-27/02 F02B 37/00 F02M 25/07 F02D 43/00

Claims (1)

(57) [Claim 1] A supercharger comprising a compressor rotated by an exhaust turbine, a first exhaust cam for opening an exhaust valve on a camshaft during an exhaust stroke, and A second exhaust cam that opens the exhaust valve for a certain period of time is provided;
In an internal combustion engine equipped with an exhaust gas recirculation device for introducing a part of exhaust gas into a cylinder by a pressure difference between intake and exhaust while the exhaust valve is simultaneously opened by the intake valve and the second exhaust cam, the internal combustion engine is connected to the intake manifold. the inertia supercharging tube, the tube
A valve that opens and closes the communication port provided in the central partition inside
An intake pulsation control device equipped with a
The number, the intake by the controller based on the operating conditions of the en <br/> Jin by the detection signal of the accelerator opening degree and a boost pressure
An exhaust gas recirculation device for an internal combustion engine, wherein an air pulsation control device is controlled to optimally control an exhaust gas recirculation rate in accordance with an operation state of the engine.