摘要:
A fuel injection pump for internal combustion engines, having a pump piston that moves in a cylinder liner and defines a pump work chamber with the cylinder. The piston has two control edges that cooperate with a control opening in the cylinder liner. One, control edge is oblique, disposed on the jacket face and communicates continuously with the pump work chamber which controls the end of supply. A first upper control edge formed by the face end of the pump piston, controls the supply onset upon overtaking the control opening. For a load- and temperature-dependent shift of the supply onset toward early, the face end of the pump piston has a first region (B), axially indented in the direction of the cam drive, forming a second control edge, which is separated from the flat region (A) on the face end by a longitudinal groove and in the first region a second region (C), indented via shoulders is disposed in turn in the direction of the cam drive, with a third control edge.
摘要:
A fuel pump for a vehicular diesel fuel pump member having a control valve assembly which includes a housing having a control valve chamber, and an actuatable control valve disposed in the control valve chamber. The control valve includes a piston valve body axially movable over a motion displacement interval between first and second positions. The motion displacement interval is defined by first and second sub-intervals bounded by the first and second positions, respectively. The control valve assembly further includes means for actuating the control valve. A valve stop is disposed in the housing adjacent the control valve chamber, and a piston valve body seat contacts the valve stop whenever the piston valve body is in the second position. The piston valve body seat contacts a pump body seating surface whenever the piston valve body is in the first position. A first control valve spring resiliently biases the piston valve body toward the unactuated position whenever the piston valve body is in the first sub-interval. A second control valve spring resiliently biases the piston valve body into damped engagement with the valve stop whenever the piston valve body is in the second sub-interval.
摘要:
A fuel injection system is proposed for Diesel type internal combustion engines, by means of which the ignition conditions of a Diesel engine are kept optimal even during operation at high altitudes despite a reduced air charge. The system includes a fuel injection pump equipped with an injection timing adjustment apparatus which functions in accordance with rpm and a control apparatus functions in accordance with the air quantity supplied to the engine. By means of the control apparatus, a correction controlled in accordance with air pressure and therefore dependent on air quantity is superimposed on the change in the onset of the fuel supply controlled by the injection adjuster at least in accordance with rpm. When a hydraulic injection adjuster is used, the supply pressure of a control pump is increased by a correcting final control element of the control apparatus when the air quantity is decreasing in the direction toward an early adjustment of the onset of supply.
摘要:
A method and apparatus for injecting fuel directly into the combustion chambers of an internal combustion engine in which a hydraulic threshold switch is provided which detects the pressure reversal of the pressure course at the end of fuel pumping by a fuel injection pump to a fuel injection valve; upon the attainment of a threshold value of the decreasing pressure, fuel is diverted into a relief chamber to effect a rapid decrease of pressure.
摘要:
A fuel injection pump for an internal combustion engine is proposed having an adjustment piston for the adjustment of the onset of the injection, on which an rpm-proportional fuel pressure determined by a pressure control valve and a pressure valve placed behind it and controllable in dependence on temperature acts. An adjustment device controls a full load stop for the limitation of the full-load fuel maximally injected by the fuel injection pump. The adjustment device has a movable piston for this purpose disposed movably in a work bore. The circumference of the piston is formed as a cam and is scanned by a scanner determining the position of the full load stop. The movable piston is acted on one side by the fuel pressure in the suction chamber and on the other side by a spring and by the fuel pressure between the pressure control valve and the pressure valve. This results in a compensation of the fuel pressure force at the movable piston, which is caused by the pressure valve.
摘要:
A fuel injection pump for Diesel engines in which a rotating and reciprocating piston pressurizes and distributes fuel to individual pressure lines leading to the injection valves of the engine. In order to change the timing of injection with respect to the engine cycle, there is provided a mechanism to change the relative angle between the pressurizing piston and its drive means, which runs in synchronism with the engine. The mechanism operates hydraulically and is affected by the fuel pressure in the sump of the injection pump. There is also provided a hydraulic control valve mechanism which permits varying amounts of fuel to flow back from the sump to the low pressure side of the fuel delivery pump, thereby changing the injection timing. A primary control valve adjusts the sump pressure on the basis of engine speed while a secondary control valve adjusts the sump pressure on the basis of engine temperature in order to adapt the timing of fuel injection to engine starting and engine warm-up. Various embodiments are presented.
摘要:
A fuel injection pump for internal combustion engines in which to control the fuel injection quantities with the internal combustion engine cold, a first control edge is provided. For controlling the start of fuel injection with the internal combustion engine hot, a second control edge and a third control edge are provided. Assigned to respective control edges are provided a first and second oblique control edge, by means of which an effective pump piston feed stroke is controlled according to the rotary position of the pump piston. To switch off the internal combustion engine, in the region of transition from the first control edge to the second control edge the assignment of this second control edge to the second oblique control edge is provided in such a way that injection ceases on account of an overlap with a control port. This measure is assisted by an additional longitudinal groove which, in this rotary position, is in overlap with an additional control port, this additional longitudinal groove being the extension of a longitudinal groove, via which a pump working space is relieved during the operation of the internal combustion engine and after a reopening of the control ports by the oblique control edges.
摘要:
A fuel injection pump of the distributor type is proposed, in which the injection quantity is controlled by controlling the first outlet cross section D of a first relief line and the stroke-offset outlet C of a second relief line for the pump work chamber of the fuel injection pump by means of a control edge that is variable in accordance with load and/or rpm. To attain nonsupply of fuel within the intended supply stroke of the pump piston during idling and at low partial load, communication between the first and second relief lines is provided. The communication exists only for the duration of a predetermined stroke portion (h.sub.e) and is additionally controlled in accordance with load and/or rpm by controlling the following outlet of the second relief line, so that from a predetermined upper load range to full-load operation, the entire fuel quantity pumped by the pump piston over the effective supply stroke does in fact become injected.
摘要:
A fuel injection pump for Diesel engines in which a rotating and reciprocating piston pressurizes and distributes fuel to individual pressure lines leading to the injection valves of the engine. In order to change the timing of injection with respect to the engine cycle, there is provided a mechanism to change the relative angle between the pressurizing piston and its drive means, which runs in synchronism with the engine. The mechanism operates hydraulically and is affected by the fuel pressure in the sump of the injection pump. There is also provided a hydraulic control valve mechanism which permits varying amounts of fuel to flow back from the sump to the low pressure side of the fuel delivery pump, thereby changing the injection timing. A primary control valve adjusts the sump pressure on the basis of engine speed while a secondary control valve adjusts the sump pressure on the basis of engine temperature in order to adapt the timing of fuel injection to engine starting and engine warm-up. Various embodiments are presented.
摘要:
A pressure control valve is connected at one end with a suction chamber and with increasing pressure in the suction chamber shifts the instant of injection to early. A pressure relief line connects between a restoring chamber in the pressure control chamber with a pressure maintenance valve. The pressure maintenance valve includes a valve insert comprising a valve cylinder in which a compression spring-loaded valve body is disposed. The valve body has a sealing face that closes the pressure relief line. The diameter of the pressure relief line is smaller than the valve cylinder diameter. The diameter of the pressure relief line is selected such that the suction chamber pressure present at the sealing face moves the valve body away from the valve seat counter to the force of a compression spring contacting the valve body and opens up a pressure relief line leading onward. After the lifting of the valve body from the pressure relief line, the suction chamber pressure is present at the entire cross section of the valve body, and the force, now embodied by the cross section of the valve body and the suction chamber pressure established at idling rpm, attains a value, by comparison with the force of the compression spring that keeps the valve body away from the pressure relief line. This assures that the function of the cold start acceleration takes place only upon the first run-up of the engine. A rapid cold start acceleration is thereby advantageously attained, and a loud engine noise is only briefly audible.