Mixer valve of an internal combustion engine

Abstract

A mixer valve of an internal combustion engine of a motor vehicle includes a single servo-motor and a differential. A flap arranged in an intake port and a flap arranged in a exhaust duct are driven by a differential. Spring elements tension the flaps in a base position counter to the stops and determine which of the flaps is driven in which control area of the servo-motor.

Claims

1. A mixer valve (6) of an internal combustion engine (1) of a motor vehicle, the mixer valve (6) comprising: an intake duct (4); an exhaust gas duct (5); a common collector duct (7), the intake duct (4) and the exhaust gas duct (5) opening into the common collector duct (7); a first flap (13) arranged in the intake duct (4); a second flap (14) arranged in the exhaust gas duct (5); a first rotatably mounted shaft (11) holding the first flap (13); a second rotatably mounted shaft (12) holding the second flap (14); and a drive device (8) configured to drive the first and second flaps (13, 14), the drive device (8) having a single actuating motor (9) and a gear mechanism (15) configured to actuate the first and second flaps (13, 14), wherein the gear mechanism (15) has a differential gear mechanism (16), and the differential gear mechanism (16) is arranged between the first and second rotatably mounted shafts (11, 12), and wherein both of the first and second rotatably mounted shafts (11, 12) are prestressed into a basic position by respective first and second spring elements (17, 18), wherein the first spring element (17) has a greater spring stiffness than the second spring element (18) so as to provide a force holding the first flap (13) in a starting position of the first flap that is greater than a force holding the second flap (14) in a starting position of the second flap, such that a delay occurs between actuation of the second flap (14) into an open position and actuation of the first flap (13).

2. The mixer valve as claimed in claim 1, wherein the first flap (13) is prestressed into an open position against a first-flap stop (19).

3. The mixer valve as claimed in claim 2, wherein the second flap (14) is prestressed into a closed position against a first second-flap stop (20).

4. The mixer valve as claimed in claim 3, wherein the second flap (14) has a second second-flap stop (21) in an open position.

5. The mixer valve as claimed in claim 1, wherein the exhaust gas duct has a greater flow resistance than the intake duct.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention allows numerous embodiments. For further clarification of its basic principle, one of said embodiments is shown in the drawing and will be described in the following text. In the drawings:

(2) FIG. 1 diagrammatically shows an internal combustion engine having a mixer valve;

(3) FIG. 2 shows the construction of the mixer valve in a diagrammatic illustration; and

(4) FIG. 3 shows a diagram of the pivoting movements of the flaps as a function of the actuating angle of a drive device.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

(5) FIG. 1 diagrammatically shows an internal combustion engine 1 having an intake line 2 and an exhaust gas line 3. The intake line 2 has an intake duct 4, via which the air is sucked from the surroundings. An exhaust gas duct 5 leads from the exhaust gas line 3 via a mixer valve 6 into the intake line 2. The mixer valve 6 combines gas flows from the intake duct 4 and from the exhaust gas duct 5 to form a common gas flow in a collector duct 7. A second valve 6 permits at least a portion of the flow from the exhaust gas line 3 to flow into the exhaust gas duct 5. The gas flows in the mixer valve 6 can be regulated by a drive device 8 having a single electric actuating motor 9. Furthermore, the internal combustion engine 1 has a turbocharger 10, which compresses a gas flow in the collector duct 7 and feeds it to the internal combustion engine 1. In order to simplify the drawing, further components of the internal combustion engine 1 and of the turbocharger 10, such as sensors, further valves and intercoolers, are not shown.

(6) FIG. 2 diagrammatically shows the mixer valve 6 with the drive device 8 from FIG. 1. In the intake duct 4 and in the exhaust gas duct 5, the mixer valve 6 in each case has pivotable shafts 11, 12 with flaps 13, 14 respectively arranged thereon for controlling the cross sections of the intake duct 4 and the exhaust gas duct 5. The drive device 8 has a gear mechanism 15, with a differential gear mechanism 16. The single actuating motor 9 drives the gear mechanism 15 which in turn drives the differential gear mechanism 16. The shafts 11, 12 and therefore the respective flaps 13, 14, are driven via the differential gear mechanism 16. In addition, the flaps 13, 14 are prestressed in each case by spring elements 17, 18, respectively into a basic position. In the basic positions, the flaps 13, 14 bear against diagrammatically illustrated stops 19, 20, respectively. The shafts 11, 12 are mounted in a housing (not shown) of the mixer valve 6. In addition, the housing accommodates the actuating motor 9 and the gear mechanism 15 with the differential gear mechanism 16.

(7) The differential gear mechanism 16 has a cage 22 driven directly by the gear mechanism 15 and in which a planetary gear 23 is mounted. The planetary gear 23 is in engagement with two drive gears 24, 25. The drive gears 24, 25 are connected fixedly to the shafts 11, 12 so as to rotate with them.

(8) The spring element 17 of the flap 13 arranged in the intake duct 4 has a greater spring stiffness than the spring element 18 of the flap 14 arranged in the exhaust gas duct 5. Therefore, during initial operation of the actuating motor 9, first of all the flap 14 arranged in the exhaust gas duct 5 is actuated, until it comes into contact with a second stop 21. During further operation of the drive device 8, the flap 14 arranged in the exhaust gas duct 5 is held on the second stop 21 and the flap 13 arranged in the intake duct 4 is adjusted.

(9) The movements of the flaps 13, 14 between a basic position and a position rotated by 90 with respect to the former over an actuating angle of from 0 to 180 are shown in FIG. 3. Here, the movement of the flap 14 arranged in the exhaust gas duct 5 is denoted by a14 and the movement of the flap 13 arranged in the intake duct 4 is denoted by a13.

(10) 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.