Mixing valve of an internal combustion engine

Abstract

A mixing valve of an exhaust-gas recirculation device of an internal combustion engine of a motor vehicle includes an intake flap and an exhaust-gas flap coupled rigidly to one another via a coupling rod. During driving of the exhaust-gas flap, the intake flap is first pivoted in the opposite direction via the coupling rod. The exhaust-gas flap and intake flap are pivoted in the same direction only above a provided pivoting angle.

Claims

1. A mixing valve (6) of an internal combustion engine (1) of a motor vehicle, comprising: an intake duct (4); an exhaust duct (5), wherein, in a first position, the exhaust duct (5) is closed and the intake duct (4) is open; a common collecting duct (7) into which the intake duct (4) and exhaust duct (5) commonly issue; an intake flap (10) affixed to an intake flap shaft and arranged in the intake duct (4) pivotably movable about a longitudinal axis of the intake flap shaft; an intake flap control lever (12) fastened to the intake flap shaft; an exhaust flap (11) affixed to an exhaust flap shaft and arranged in the exhaust duct (5) pivotably movable about a longitudinal axis of the exhaust flap shaft; an exhaust flap control lever (13) fastened to the exhaust flap shaft; a drive device (8) driving the intake flap (10) and the exhaust flap (11); and a coupling device (14) coupled to the exhaust flap control lever (13) and to the intake flap control lever (12), the coupling device having a coupling rod (15) having a first end directly and hingedly connected to the exhaust flap control lever (13) and a second end directly and hingedly connected to the intake flap control lever (12), wherein the coupling rod (15) provides, by the direct and hinged connection between the first end of the coupling rod (15) and the exhaust flap control lever (13) and by the direct and hinged connection between the second end of the coupling rod (15) and the intake flap control lever (12), direct transmission of movements of the intake flap control lever (12) and the exhaust flap control lever (13) to one another, such that, in the first position, in which the exhaust duct (5) is closed and the intake duct (4) is open, the exhaust flap control lever (13) and the coupling rod (15) contact one another so as to form an obtuse angle between the exhaust flap control lever (13) and the coupling rod (15), and the intake flap control lever (12) and the coupling rod (15) contact one another so as to form an acute angle between the intake flap control lever (12) and the coupling rod (15).

2. A mixing valve (6) of an internal combustion engine (1) of a motor vehicle, comprising: an intake duct (4); an exhaust duct (5), wherein, in a first position, the exhaust duct (5) is closed and the intake duct (4) is open; a common collecting duct (7) into which the intake duct (4) and exhaust duct (5) commonly issue; an intake flap (10) affixed to an intake flap shaft and arranged in the intake duct (4) pivotably movable about a longitudinal axis of the intake flap shaft; an intake flap control lever (12) fastened to the intake flap shaft; an exhaust flap (11) affixed to an exhaust flap shaft and arranged in the exhaust duct (5) pivotably movable about a longitudinal axis of the exhaust flap shaft; an exhaust flap control lever (13) fastened to the exhaust flap shaft; a drive device (8) driving the intake flap (10) and the exhaust flap (11); and a coupling device (14) coupled to the exhaust flap control lever (13) and to the intake flap control lever (12), the coupling device having a coupling rod (15) connected to each of the exhaust flap control lever (13) and the intake flap control lever (12), wherein the coupling rod (15) is configured to provide direct transmission of movements of the intake flap control lever (12) and the exhaust flap control lever (13) to one another, and, in the first position, the exhaust flap control lever (13) and the coupling rod (15) contact one another and are arranged at an obtuse angle relative to one another, and the intake flap control lever (12) and the coupling rod (15) contact one another and are arranged at an acute angle relative to one another, and wherein, proceeding from the first position, the intake flap control lever (12) and the exhaust flap control lever (13) and the coupling rod (15) are arranged such that the movements of the exhaust flap (11) and of the intake flap (10) take place in opposite directions and, after a partial movement, take place in a same direction.

3. A mixing valve (6) of an internal combustion engine (1) of a motor vehicle, comprising: an intake duct (4); an exhaust duct (5), wherein, in a first position, the exhaust duct (5) is closed and the intake duct (4) is open; a common collecting duct (7) into which the intake duct (4) and exhaust duet (5) commonly issue; an intake flap (10) affixed to an intake flap shaft and arranged in the intake duct (4) pivotably movable about a longitudinal axis of the intake flap shaft; an intake flap control lever (12) fastened to the intake flap shaft; an exhaust flap (11) affixed to an exhaust flap shaft and arranged in the exhaust duct (5) pivotably movable about a longitudinal axis of the exhaust flap shaft; an exhaust flap control lever (13) fastened to the exhaust flap shaft; a drive device (8) driving the intake flap (10) and the exhaust flap (11); and a coupling device (14) coupled to the exhaust flap control lever (13) and to the intake flap control lever (12), the coupling device having a coupling rod (15) connected to each of the exhaust flap control lever (13) and the intake flap control lever (12), wherein the coupling rod (15) is configured to provide direct transmission of movements of the intake flap control lever (12) and the exhaust flap control lever (13) to one another, and, in the first position, the exhaust flap control lever (13) and the coupling rod (15) contact one another and are arranged at an obtuse angle relative to one another, and the intake flap control lever (12) and the coupling rod (15) contact one another and are arranged at an acute angle relative to one another, and wherein, in the first position, the exhaust flap control lever (13) is situated ahead of a dead center at which said exhaust flap control lever (13) forms a straight line with the coupling rod (15).

4. The mixing valve as claimed in claim 1, wherein the intake flap control lever (12) is of a different length than the exhaust flap control lever (13).

5. The mixing valve as claimed in claim 1, wherein the drive device (8) has an actuating motor (9) driving the exhaust flap (11).

6. The mixing valve as claimed in claim 1, wherein the exhaust duct (5) is arranged at right angles to the intake duct (4), in that, in the first position, the exhaust flap (11) is arranged approximately parallel to the intake flap (10), and in that the intake flap control lever (12) and the exhaust flap control lever (13) face toward one another.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention permits numerous embodiments. To further illustrate its basic principle, one of the embodiments is illustrated in the drawings and described below. In the drawings:

(2) FIG. 1 schematically shows an internal combustion engine of a motor vehicle having a mixing valve according to the invention;

(3) FIG. 2 schematically shows the mixing valve from FIG. 1 in a first position;

(4) FIGS. 3 and 4 show the mixing valve from FIG. 2 in intermediate positions;

(5) FIG. 5 shows the mixing valve from FIG. 2 in an end position; and

(6) FIG. 6 shows the profile of deflection angles of an intake flap and of an exhaust flap versus an actuation signal.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

(7) FIG. 1 schematically shows an internal combustion engine 1 having an intake line 2 and having an exhaust line 3. The intake line 2 has an intake duct 4 via which air is drawn in from the environment. An exhaust duct 5 leads from the exhaust line 3 into the intake line 2 via a mixing valve 6. The mixing valve 6 merges the intake duct 4 and the exhaust duct 5 to form a collecting duct 7. The collecting duct 7 leads directly to the internal combustion engine 1. A drive device 8 with an electric actuating motor 9 permits an adjustment of the mixing valve 6.

(8) FIG. 2 shows an enlarged sectional illustration of the mixing valve 6, with sub-regions of the intake duct 4, of the exhaust duct 5 and of the collecting duct 7. In the intake duct 4 there is arranged an intake flap 10 which, in the illustrated first position, is almost fully open. In the illustrated first position, an exhaust flap 11 arranged in the exhaust duct 5 is fully closed. Respective control levers 12, 13 are fastened to shafts of the intake flap 10 and of the exhaust flap 11. The control levers 12, 13 are connected by way of a coupling device 14 to a coupling rod 15. In the illustrated first position of the mixing valve 6, the coupling rod 15 and control lever 13 of the exhaust flap 11 form an obtuse angle, whereas the coupling rod 15 and control lever 12 of the intake flap 10 form an acute angle. When the control lever 13 of the exhaust flap 11 is driven counterclockwise, the coupling rod 15 is pivoted and, as far as a dead center illustrated in FIG. 3, is displaced in the direction of control lever 12 of the intake flap 10. In this way, the intake flap 10 is pivoted clockwise.

(9) In FIG. 3, the control lever 13 of the exhaust flap 11 is situated at the described dead center with the coupling rod 15. At the dead center, the coupling rod 15 and control lever 13 of the exhaust flap 11 form a straight line. This characterizes a reversal point of the intake flap 10.

(10) If, proceeding from the position in FIG. 3, the control lever 13 of the exhaust flap 11 is pivoted further counterclockwise, the intake flap 10 is, by way of the coupling rod 15, likewise jointly pivoted counterclockwise. The positions of the intake flap 10 and of the exhaust flap 11 during the movement are illustrated in FIG. 4. A shaft shadow W is illustrated in FIGS. 2 to 4. The shaft shadow W indicates the extent to which the cross section of the intake duct 4 is constricted by a shaft (not illustrated) to which the intake flap 10 is fastened.

(11) FIG. 5 shows an end position of the mixing valve 6, in which the exhaust duct 5 is fully open. The intake duct 4 is partially closed. The position of the intake flap 10 in the end position can be set by way of the ratios of the lengths of the control levers 12, 13.

(12) FIG. 6 shows the profile of the pivot angle α10 of the intake flap 10 and of the pivot angle α11 of the exhaust flap 11 as a function of an actuation signal S of the drive device 8 from FIG. 1. It can be seen here that the pivot angle α11 of the exhaust flap 11 increases linearly with the actuation signal S. In a first range, however, the pivot angle α10 of the intake flap 10 fluctuates within the shaft shadow W. Only when the intake flap 10 emerges from the shaft shadow W does the closing process of the intake duct 4 take place. For illustrative purposes, in FIG. 6, the positions of the exhaust flap 11 and of the intake flap 10 of FIGS. 2 to 5 are denoted by Roman numerals II to V.

(13) Thus, while there have been shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.