Device for controlling gas exchange valves

Abstract

An apparatus for controlling gas exchange valves of an internal combustion engine is disclosed, which have hydraulic valve actuators ( 11 ) each assigned to one gas exchange valve, with one adjusting piston ( 13 ) acting on the gas exchange valve and two hydraulic work chambers ( 121, 122 ) defined by the adjusting piston ( 13 ), of which chambers the first work chamber ( 121 ), acting on the gas exchange valve ( 10 ) in the closing direction, is constantly filled with fluid that is under pressure, and the second work chamber ( 122 ), acting on the gas exchange valve ( 10 ) in the opening direction, can be filled with and relieved of fluid that is under pressure in alternation via a first and second electrical control valve ( 24, 25; 26, 27 ). To reduce the cost, the second control valves, which are preferably combined into a valve unit ( 40 ), for one pair of valve actuators ( 11 ), which actuate two gas exchange valves used as inlet or outlet valves of a combustion cylinder, are triggered by a common electrical control signal

1 . An apparatus for controlling gas exchange valves in combustion cylinders of an internal combustion engine, having hydraulic valve actuators ( 11 ), each of which is assigned to one gas exchange valve ( 10 ) and which each have one adjusting piston ( 13 ), acting on the gas exchange valve ( 10 ), and two hydraulic work chambers ( 121 ,  122 ) defined by the adjusting piston ( 13 ), of which chambers the first work chamber ( 121 ), acting on the gas exchange valve ( 10 ) in the closing direction, is constantly filled with a fluid that is under pressure, and the second work chamber ( 122 ), acting on the gas exchange valve ( 10 ) in the opening direction, can be filled with and relieved of a fluid that is under pressure via a first and second electrical control valve ( 24 ,  25 ;  26 ,  27 ), characterized in that the second control valves ( 25 ,  27 ) for one pair of valve actuators ( 11 ), which actuate two gas exchange valves ( 10 ) used as inlet or outlet valves in one combustion cylinder, are triggered by a common electrical control signal.  
     
     
         2 . The apparatus of  claim 1 , characterized in that the electrical control inputs of the two second control valves ( 25 ,  27 ) are connected to the same signal output ( 302 ) of an electronic control unit ( 30 ).  
     
     
         3 . The apparatus of  claim 1  or  2 , characterized in that the two second control valves ( 25 ,  27 ), associated with one pair of valve actuators, are embodied as a valve unit ( 40 ), with one common electrical control input.  
     
     
         4 . The apparatus of  claim 3 , characterized in that the valve unit ( 40 ) is a 4/2-way magnet valve ( 45 ), with two switching positions and four controlled valve connections ( 451 - 454 ), of which a first and a second valve connection ( 451 ,  452 ) each communicate with a respective relief line ( 28 ,  29 ), and a third valve connection ( 453 ), which can be connected to the first valve connection ( 451 ), and a fourth valve connection ( 454 ), which can be connected to the second valve connection ( 452 ), can each communicate with a respective second work chamber ( 122 ) of the pair of valve actuators.  
     
     
         5 . The apparatus of  claim 3 , characterized in that the valve unit ( 40 ) is a 3/2-way magnet valve ( 44 ), with two switching positions and three controlled valve connections ( 441 - 443 ), of which a first valve connection ( 441 ) communicates with a relief line ( 28 ), and the two further valve connections ( 442 ,  443 ), which can be connected simultaneously to the first valve connection ( 441 ), each communicate with a respective second work chamber ( 122 ) of the pair of valve actuators.  
     
     
         6 . The apparatus of  claim 3 , characterized in that the valve unit ( 40 ) is a 2/2-way magnet valve ( 41 ), with two switching positions and two controlled valve connections ( 411 ,  412 ), of which one valve connection ( 411 ) is connected to a relief line ( 28 ), and the other valve connection ( 412 ) is connected, each via a respective connecting line ( 35 ,  36 ), to the second work chambers ( 122 ) of the pair of valve actuators; and that in at least one connecting line ( 35 ,  36 ), there is a check valve ( 42 ,  43 ), with a flow direction pointing toward the 2/2-way magnet valve ( 41 ).  
     
     
         7 . The apparatus of  claim 3 , characterized in that the valve unit ( 40 ) is a 4/3-way magnet valve ( 46 ), with three switching positions and four controlled valve connections ( 461 - 464 ), of which two valve connections ( 461 ,  462 ) each communicate with a respective relief line ( 28 ,  29 ), and two valve connections ( 463 ,  464 ) each communicate with a respective work chamber ( 122 ) of the pair of valve actuators; and that the 4/3-way magnet valve ( 46 ) is embodied such that in one switching position, both second work chambers ( 122 ) each communicate with a respective relief line ( 28 ,  29 ), while in a further switching position, both second work chambers ( 122 ) are blocked, and in a third switching position, one of the two second work chambers ( 122 ) is blocked while the other communicates with a relief line ( 28 ).  
     
     
         8 . The apparatus of  claim 3 , characterized in that the valve unit ( 40 ) is a 4/4-way magnet valve ( 47 ), with four switching positions and four controlled valve connections ( 471 - 474 ), of which two valve connections ( 471 ,  472 ) each communicate with a respective relief line ( 28 ,  29 ), and two valve connections ( 473 ,  474 ) each communicate with a respective second work chamber ( 122 ) of the pair of valve actuators; and that the 4/4-way magnet valve ( 47 ) is embodied such that in one switching position, the second work chambers ( 122 ) of the pair of valve actuators communicate with the relief lines ( 28 ,  29 ), in a further switching position the second work chambers ( 122 ) are blocked off, and in the two further switching positions, in alternation, one of the two second work chambers ( 122 ) communicates with a respective relief line ( 28  or  29 ), and the other of the second work chambers ( 122 ) is blocked.  
     
     
         9 . The apparatus of  claim 1  or  2 , characterized in that each valve actuator ( 11 ), with associated first and second control valves ( 24 ,  25 ;  26 ,  27 ), which are preferably embodied as 2/2-way magnet valves, is integrated into a respective actuator housing ( 37 ;  38 ).  
     
     
         10 . The apparatus of one of claims  3 - 8 , characterized in that the two valve actuators ( 11 ) of a pair of valve actuators and the associated control valves ( 24 ,  26 ,  40 ) are integrated into a common actuator housing ( 39 ).