Man Nutzfahrzeuge Ag

Man Nutzfahrzeuge Gmbh

Maschinenfabrik Augsburg-Nurnberg Aktiengesellschaft

M.a.n. Maschinenfabrik Augsburg-Nurnberg A.g.

Heribert Kubis

Josef Winter

Dieter Wittmann

Karl Schott

Hans Gebhardt

Gerhard Deschler

Dieter Wittman

A device for controlling an outlet valve during the engine brake mode has a hydraulic linkage between the outlet valve and the cam shaft which is controllable by a control unit. The control unit is combined with an actuation piston of a pressure source to form an integral component which is identical for each outlet valve. The actuation piston is actuated by a brake cam and actuates the working piston of the hydraulic linkage via the intermediate control unit. With the actuation piston the outlet valve can be opened during the engine braking mode in the compression stroke in order to substantially increase the braking power of the engine. The combination of the control unit with the actuation piston in the form of an integral component allows for an inexpensive manufacture because each individual outlet valve can be provided with such an identical control component. Furthermore, by eliminating long connecting lines for the pressure medium with the integral component precise control times for the outlet valve can be achieved.

Device for controlling an outlet valve in the engine brake mode

A cylinder head sealing arrangement for reciprocating piston engines, especially internal combustion engines. An end of each cylinder liner that faces a cylinder head is provided with a raised collar that includes a centering portion. A preferably metallic combustion chamber seal in the form of a ring having a constant thickness in a starting position is guided with clearance fit. When cylinder head screws are tightened, the ring undergoes a plastic deformation of at least one end face. The ring has an inner surface that is guided relative to the centering portion only via a cylindrical guide region of the ring or the raised collar. The free space between the ring and the centering portion increases continuously proceeding from the guide region so that after plastic deformation the ring rests flat upon the cylinder liner beyond the region of a radius that defines a transition between the liner and the collar.

Cylinder head sealing arrangement for reciprocating piston engines

A method and apparatus for decelerating a marine propulsion system during an emergency stop maneuver is provided. In order to achieve a faster reversal of the direction of rotation of a propeller shaft an engine brake is activated before switching the three shaft birotatory reduction gear system in order to decelerate the engaged and rotating gear system parts effectively. Only when the rotation of the gear system parts has been reduced to a predetermined number of revolutions the gear system is switched to the reversed direction of rotation by a control switch on the bridge so that the propeller shaft is rotating in the reversed direction of rotation and subsequently the number of revolutions of the combustion engine is increased to full load. The emergency stop maneuver may be performed in a very short period of time with the proposed method. The apparatus comprises a motor brake having a throttle valve eccentrically supported in the exhaust pipe of the combustion engine.

Method and apparatus for decelerating a marine propulsion system during

An outlet valve lifter for internal combustion engine is described. In order to increase the braking power of the internal combustion engine it is necessary that the outlet valve is opened during the compression cycle. Advantageously, this is achieved by a hydraulic outlet valve lifter which is actuated by an external pressure source. Due to the pressure of the compressed air shortly before the ignition top dead center position great forces are acting on the outlet valve and accordingly on the outlet valve lifter. These forces, in the form of hydraulic pressure, act via the inner portion of the outlet valve lifter on the external pressure source and may cause damage. Therefore, the outlet valve lifter is provided with an inner portion which is lifted by a certain stroke due to the pressure actuation via a second pressure chamber so that the outlet valve opens. When the pressure within the second pressure chamber increases as a function of the forces acting on the outlet valve and surpasses the hydraulic pressure generated by the external pressure source, a ball valve closes the second pressure chamber so that the hydraulic pressure generated therein may not be transmitted to the external pressure source.

Outlet valve lifter for an internal combustion engine

A motor brake for air-compressing internal combustion engines is provided. To improve the braking power of the engine, it is proposed to combine a motor brake having a butterfly valve to throttle engine exhaust with a motor brake where an exhaust valve, in addition to the cam drive, can be raised slightly during the exhaust stroke via a piston. With this inventive combination, braking work can be performed not only in the exhaust stroke, but also in the compression stroke, so that the braking power can be increased by about 50 to 60%, and relative to conventional exhaust brakes by about 80 to 90%, and is increased to the order of magnitude of the effective engine power.

Motor brake for air-compressing internal combustion engines

A motor brake for an air-compressing internal combustion engine is provided. A hydraulic linkage system is disposed between a cam and an exhaust valve, and communicates via a connecting line with a high-speed solenoid valve and a linkage oil compensating system of an engine lubricating-oil circuit. A control valve is disposed in an exhaust manifold of the engine and upon actuation of the motor brake partially closes off the exhaust manifold along with activation of the solenoid valve. Via the interposition of a control unit, signals of at least one sensor are conveyed to a solenoid of the solenoid valve in such a way that, upon actuation of the motor brake during a specific time interval during lifting of a valve tappet via a projection of the cam in a compression phase, the solenoid valve is closed. The time interval is derived via processing of signals of the sensor formed from the cam position and camshaft speed. The cam is divided into six sectors having a first angular range for opening the exhaust valve in an exhaust phase, a second angular range for filling a cylinder space of the valve tappet, a third angular range for initiating closure of the solenoid valve, a fourth angular range for the cam projection, a fifth angular range for reopening the solenoid valve, and a sixth angular range for emptying the cylinder space.

A cylinder head sealing element for reciprocating piston engines, especially internal combustion engines, and advantageously engines having cylinder liners, is provided. To solve the increasingly more difficult problem of sealing the cylinder head where the power density of internal combustion engines is increased, a ring-like sealing element is provided, the end faces of which plastically deform when the cylinder head screws are tightened. The inner deformations of the cylinder head resulting from pressure forces in the cylinder are compensated for by elastic yielding of the sealing ring of the combustion chamber. The dimensions of the rib of a collar of a cylinder liner, of the groove of the cylinder head, and of the end faces of the sealing ring are coordinated with one another in such a way that the plastic deformation of the sealing ring is not of such a magnitude that the cylinder liner can deform. The sealing ring can therefore be disposed directly in a centering means of the cylinder liner, thus eliminating the need for special centering devices.

Cylinder head sealing element for reciprocating piston engines

A gear wheel drive air compressor which is constructed as a piston compressor, the drive gear wheel of which on the air compressor crankshaft meshes with a gear wheel on the camshaft of the internal combustion engine. The inventive construction prevents the reverse acceleration of the camshaft drive gear wheel and minimizes the knocking pulse and noise in the mesh of the camshaft gear wheel in that the transmission ratio between the air compressor drive gear wheel and the camshaft gear wheel is embodied as a multiple load cycle of the camshaft drive torque, and at the same time the angular position of the air compressor crankshaft relative to the camshaft is fixed such that negative torque components of the air compressor crankshaft are eliminated by the overlapping of positive torque components of the camshaft. Furthermore, the air compressor drive gear wheel is arranged in alignment with the air compressor crankshaft.

Auxiliary drive of an internal combustion engine for an air compressor

A sturdy threaded insert for screws having a trapezoidal thread. To keep the external diameter of this threaded insert small (due to the limited space often available), and to ensure that the female thread produces a perfect seal (if the threaded insert is closed in construction), the threaded insert is constructed as follows: The basic shape of the threaded insert represents a circumscribed quadrilateral, which is a rhombus if the trapezoidal thread is symmetrical and is a parallelogram if the trapezoidal thread is asymmetrical. The superimposed quadrilateral profiles are connected to one another by a web having a minimum wall thickness of about 30% of the useful profile depth of the screw thread, and in any case is at least 0.3 mm. In addition, the threaded flank projections of the annular surfaces are equal on the workpiece side and on the screw side.

Threaded insert having a small external diameter for screws having a

A cylinder head and combustion chamber sealing arrangement that is subdivided into a sealing element in the cylinder liner region (especially for sealing gas) and a sealing element in the cylinder block region. Both sealing elements are made of solid metal. The sealing element for gas sealing, which is disposed in the liner-collar recess, is stressed in a certain range beyond the yield limit of the material by tightening the cylinder head screws. To improve the gas sealing, on the one hand a circumferential groove is provided in the cylinder head opposite the recess in the cylinder liner collar, and on the other hand the recess itself is provided with either a circumferential groove or a circumferential rib. By this means, the liner sealing element is stressed beyond the material yield level in the specific region of its outer and inner perimeters.

Cylinder head and combustion chamber sealing arrangement for a

A reciprocating piston engine having a sealing system between the cylinder head and the cylinder liner, or the cylinder block, using a metal gasket. It is proposed to improve such a system in a manner that, while large manufacturing tolerances are permitted, i.e. tolerances on the dimensional design of the cooperating parts as well as on the cylinder head bolt torque, reliable gastight sealing of the combustion chamber is ensured at all times. This is essentially achieved in that a circumferential raised portion on the liner flange is the only part that projects beyond the top end (sealing face) of the cylinder block and is matched to the metal gasket in a manner that when the cylinder head is tightened down on the cylinder block, the cylinder head gasket is always stressed above the yield point, with the metal gasket having such a stress/strain characteristic that once the yield point is exceeded, the horizontal deformation range (i.e. where the compressive stress is constant) is as great as possible.

Reciprocating piston engine

A fresh-gas intake system for engines with combination supercharging, i.e. exhaust gas turbocharging combined with resonance supercharging. The object is to improve such a system so as to make it very compact. On the one hand, the otherwise usual plenum tank is omitted, and on the other hand the incorporation of the resonance pipes in the integral unit, as well as the supply of the fresh gas, is improved. This is essentially achieved in that at least one resonance tank is formed with such a length that it extends over all of the inlet port openings of all of the in-line cylinders, and in that the fresh gas supplied by the turbocharger is delivered via a supply cover into the resonance pipes.

Compact fresh-gas intake system for engines with combination

A common coolant circuit for cooling an internal combustion engine, on the one hand, and the charge air and possibly other media, on the other hand. In order to achieve a constant positive flow through the charge air cooler (intercooler) of a coolant which is at a low temperature level of 45.degree. C. or less and, respectively, to ensure rapid heating of the engine after cold starting, a single four-way thermostat incorporating a double valve is provided. In the cold starting mode, the valve causes a bypass operation of the coolant in the cooling jacket of the engine and the coolant in the common cooling circuit, in conjunction with a separate coolant pump for each. In the hot operating mode, the valve controls circulation of a pre-determined coolant flow in the cooling circuit. The thermostat element of the thermostat is constantly exposed, during this process, to a pre-determined coolant flow from the cooling jacket of the engine (more specifically the coolant outlet of the engine).

Single-circuit cooling system for intercooled marine engines

A multi-cylinder internal combustion engine has flangeless wet cylinder liners to reduce the size of the engine. Each cylinder liner has a shoulder near its crankcase end for sealing a coolant space around the liner and for compression against a seat of an engine block with an individual cylinder head at its opposite, flangeless cylinder head end. Near the cylinder head ends, the liners have side sealing lands cooperative with sealing lands on a web of the engine block without affixation thereto for sealing the adjacent end of the coolant space, the web being thin because it does not support the cylinder head to reduce further the engine size.

Cylinder liner for a multi-cylinder internal combustion engine and an

An oil pump arrangement for the pressure oil supply for internal combustion engines, especially a gear oil pump, which includes impeller gears housed in a pump housing. The gears are driven by the internal combustion engine and the pump housing is connected with a suction pipe and a pressure pipe. The pump housing is arranged in an unmachined recess provided at the side of the timing gears in the crankcase. The pump housing is open on the side of the driving means for the impeller gears and is flanged to the timing gear case of the internal combustion engine. The timing gear case forms the closure of the pump housing and the recess, and at least the driving means for the impeller gears is supported in the timing gear case.

Growing community of inventors

Nurnberg, Germany

Heribert Kubis