EP0733160A1 - Fuel-injection system for a two-stroke internal-combustion engine - Google Patents

Fuel-injection system for a two-stroke internal-combustion engine

Info

Publication number
EP0733160A1
EP0733160A1 EP95928417A EP95928417A EP0733160A1 EP 0733160 A1 EP0733160 A1 EP 0733160A1 EP 95928417 A EP95928417 A EP 95928417A EP 95928417 A EP95928417 A EP 95928417A EP 0733160 A1 EP0733160 A1 EP 0733160A1
Authority
EP
European Patent Office
Prior art keywords
pump
pressure
fuel injection
fuel
combustion engine
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP95928417A
Other languages
German (de)
French (fr)
Other versions
EP0733160B1 (en
Inventor
Helmut Rembold
Gottlob Haag
Heinz Britsch
Heinz Stutzenberger
Uwe Mueller
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Robert Bosch GmbH filed Critical Robert Bosch GmbH
Publication of EP0733160A1 publication Critical patent/EP0733160A1/en
Application granted granted Critical
Publication of EP0733160B1 publication Critical patent/EP0733160B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D1/00—Controlling fuel-injection pumps, e.g. of high pressure injection type
    • F02D1/02—Controlling fuel-injection pumps, e.g. of high pressure injection type not restricted to adjustment of injection timing, e.g. varying amount of fuel delivered
    • F02D1/06—Controlling fuel-injection pumps, e.g. of high pressure injection type not restricted to adjustment of injection timing, e.g. varying amount of fuel delivered by means dependent on pressure of engine working fluid
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D1/00—Controlling fuel-injection pumps, e.g. of high pressure injection type
    • F02D1/02—Controlling fuel-injection pumps, e.g. of high pressure injection type not restricted to adjustment of injection timing, e.g. varying amount of fuel delivered
    • F02D1/025—Controlling fuel-injection pumps, e.g. of high pressure injection type not restricted to adjustment of injection timing, e.g. varying amount of fuel delivered by means dependent on engine working temperature
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D1/00—Controlling fuel-injection pumps, e.g. of high pressure injection type
    • F02D1/02—Controlling fuel-injection pumps, e.g. of high pressure injection type not restricted to adjustment of injection timing, e.g. varying amount of fuel delivered
    • F02D1/06—Controlling fuel-injection pumps, e.g. of high pressure injection type not restricted to adjustment of injection timing, e.g. varying amount of fuel delivered by means dependent on pressure of engine working fluid
    • F02D1/065—Controlling fuel-injection pumps, e.g. of high pressure injection type not restricted to adjustment of injection timing, e.g. varying amount of fuel delivered by means dependent on pressure of engine working fluid of intake of air
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M69/00—Low-pressure fuel-injection apparatus ; Apparatus with both continuous and intermittent injection; Apparatus injecting different types of fuel
    • F02M69/10—Low-pressure fuel-injection apparatus ; Apparatus with both continuous and intermittent injection; Apparatus injecting different types of fuel peculiar to scavenged two-stroke engines, e.g. injecting into crankcase-pump chamber
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B75/00—Other engines
    • F02B75/02—Engines characterised by their cycles, e.g. six-stroke
    • F02B2075/022—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle
    • F02B2075/025—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle two

Definitions

  • the invention is based on one
  • Fuel injection device according to the preamble of claim 1. It is already one
  • Fuel injection device for a two-stroke internal combustion engine is known (special print from MTZ, Motortechnische Zeitschrift, Volume 13, Issue 10, October 1952), in which a fuel injection pump delivers fuel to a fuel injector that injects directly into a combustion chamber of the two-stroke internal combustion engine.
  • the fuel injection pump is designed in a so-called in-line pump type, in which each cylinder of the two-stroke internal combustion engine is supplied with fuel via a separate pump element.
  • the pump element is composed of a pump piston and a pump cylinder.
  • the pump piston is guided in a longitudinally displaceable manner in the pump cylinder and is driven by a camshaft of the two-stroke internal combustion engine via a drive element.
  • a throttle valve rotatably mounted in a throttle valve neck is actuated, for which purpose a linkage is provided on the throttle valve, which is connected to an accelerator pedal or a throttle lever.
  • a certain negative pressure is established in the throttle valve neck, which depends on the rotational position of the throttle valve, so that it can be used to regulate the delivery rate of the fuel injection pump.
  • the vacuum is taken downstream of the throttle valve and led to an adjusting device via a pulse pressure line.
  • the adjustment device is part of the fuel injection pump and regulates the delivery rate of the fuel injection pump depending on the negative pressure prevailing in the throttle valve connector.
  • the pump piston is rotated, which has a recess on its outer lateral surface, which is designed in the form of an obliquely extending control edge.
  • the pump piston uses the control edge to control a control bore that is recessed in the pump cylinder and opens into a pump working chamber of the pump piston, the rotational position of the control edge with respect to the control bore determining the delivery end of the pump piston.
  • the position of the pump piston in the pump cylinder changes the useful stroke and thus the delivery rate.
  • a sleeve-shaped control element which has an opening in its interior with two longitudinal slots, on which a driver formed on the pump piston, for example in the form of a piston vane, slides axially and only rotates on the longitudinal slots when the control element is rotated of the pump piston attacks.
  • the latter has, for example, a clamped tooth segment on its outer surface, on which a control rod, which is accommodated transversely to a longitudinal axis of the pump piston in the housing of the fuel injection pump, engages with an external toothing in order to
  • the control rod is attached at one end to a diaphragm of an adjusting device which, depending on the negative pressure in the throttle valve connector, the delivery rate of the Fuel injection pump determined.
  • the membrane of the adjusting device separates two pressure chambers, a connection pressure chamber and a signal pressure chamber, from one another in a pressure-tight manner, so that the membrane is moved in the direction of the pressure drop if there is a pressure difference between the connection pressure chamber and the signal pressure chamber.
  • control pressure chamber is pressurized with ambient pressure and the connection pressure chamber with negative pressure of the throttle valve connector, so that depending on the pressure difference applied to the diaphragm, the control rod is displaced and the pump piston rotates via the control element.
  • the delivery rate to changing operating parameters of the two-stroke internal combustion engine in an extremely complex manner. Additional devices are required for this.
  • the influence of the ambient pressure decreasing with increasing geodetic altitude and thus decreasing air filling of the cylinders of the two-stroke internal combustion engine can only be detected by means of an additional altitude pressure sensor.
  • the temperature influence of the air drawn in by the two-stroke internal combustion engine can only be detected by means of a temperature sensor which, in conjunction with the fuel injection pump, adapts the delivery rate to the air temperature accordingly.
  • the temperature sensor is usually housed outside the fuel injection pump in the throttle valve connector.
  • the temperature sensor is connected to the control rod of the fuel injection pump by means of a linkage in order to compensate for this depending on the temperature of the air drawn in press so that the flow rate is adjusted to different intake air temperatures.
  • the fuel injection device according to the invention with the characterizing features of claim 1 has the advantage that the delivery rate of the fuel injection pump can be easily adapted to changing operating parameters of the two-stroke internal combustion engine, the proportions of harmful exhaust gas components and the consumption of the two-stroke engine in particular Reduce the internal combustion engine significantly.
  • a start device that can be activated in the cold start of the two-stroke internal combustion engine enables a further reduction in the harmful exhaust gas components.
  • FIG. 1 shows a schematic functional diagram of a fuel injection device according to the invention
  • FIG. 2 shows a section through a fuel injection pump according to a first exemplary embodiment according to the invention
  • FIG. 3 shows a section through the fuel injection pump along a line XII-III ' in FIG. 2
  • FIG. 4 shows a section through the fuel injection pump according to FIG a second embodiment of the invention.
  • FIG. 1 shows a schematic functional diagram of a fuel injection device 1 according to the invention, in which a fuel injection pump 2 is used
  • Fuel supply to a two-stroke internal combustion engine 4 partially shown in section is provided.
  • the fuel injection pump 2 delivers fuel to a fuel injection valve 3 provided on a cylinder 5 of the two-stroke internal combustion engine 4, which injects the fuel directly into a combustion chamber 12 of the two-stroke internal combustion engine 4.
  • the two-stroke internal combustion engine 4 sucks the combustion air required for combustion into an interior 10 of a crankcase 11 of the two-stroke internal combustion engine via an intake pipe 9, from which it is controlled by a piston 6, which is displaceably accommodated in the cylinder 5, by means of overflow channels (not shown) Combustion chamber 12 enters.
  • the exhaust gases produced during the combustion are discharged from the combustion chamber 12 via an outlet duct 14.
  • the two-stroke internal combustion engine 4 is provided, for example, for driving hand-held drive devices, such as motor chain saws, cut-off machines, brush cutters and mopeds, motor boats and lawn mowers or the like.
  • a fuel feed pump 15 supplies fuel to the fuel injection pump 2 and, as shown in FIG. 1, is shown within a dashed line
  • the fuel feed pump 15 is located in the interior 10 of the
  • crankcase 11 driven pulsating internal pressure in the crankcase 11 of the two-stroke internal combustion engine 4, for which purpose a pressure line 26 is provided, which from a working space 25 delimited by a membrane 24 of the low-pressure pump part 17 to the interior 10 of the
  • the membrane 24 controls one Ram 27 a pump diaphragm 28 which delimits a pump chamber 29.
  • the pump chamber 29 is connected via a suction valve 30 to a fuel inlet 31 which supplies the fuel from a fuel tank 32. Via a pressure valve 33 and a low pressure line 34, the
  • Fuel is guided in the direction of the arrows 39 to a low-pressure connection 35 of the fuel injection pump 2, excess fuel conveyed from the low-pressure pump part 17 flowing in the direction of the arrows 40 in a provided fuel return line 37 via a return valve 36 from the fuel injection pump 2 to the fuel tank 32.
  • the basic structure of the fuel injection pump 2 and the fuel injection valve 3 correspond to known diesel technology. Since the fuel is no longer introduced into the intake pipe 9 in the form of an oil-mixed fuel-air mixture in the combustion chamber 12 via an otherwise conventional carburetor, but is instead injected directly into the combustion chamber 12 and therefore no longer with a cylinder inner wall 41 of the two-stroke cycle Internal combustion engine 4 comes into contact, a lubricating oil pump 42 is required.
  • the lubricating oil pump 42 delivers oil to the crankshaft bearing, connecting rod bearing, piston pin eye and, in particular, to the cylinder inner wall 41.
  • the lubricating oil pump 42 is driven, for example, by a crankshaft 43 of the two-stroke internal combustion engine 4 shown in dashed lines in FIG of the piston 6 converts into a rotary movement of the crankshaft 43.
  • the lubricating oil pump 42 has a screw conveyor for pumping the oil, which has, for example, a bevel gear at its end.
  • the bevel toothing engages in a spline toothing provided on the crankshaft 43 in order to convey the oil out of an oil container 45 by means of the screw conveyor and, for example, provided oil filter 46 via a pressure valve 47.
  • the fuel injection pump 2 is designed as a so-called plug-in injection pump. As shown in FIG.
  • a pump piston 55 and a pump cylinder 56 form a single pump element which conveys the fuel to the two-stroke internal combustion engine 4, for example, a single-cylinder engine. It is also possible to design the fuel injection pump in a so-called in-line pump type, in which a single pump element is provided for each cylinder, which are arranged in series in a common housing. As shown in FIG. 1, the fuel injection pump 2 is driven in a known manner by a cam 53 attached to the crankshaft 43 via a drive element 50 of the fuel injection pump 2. As shown in FIG.
  • the drive element 50 is composed of a plunger 51 which can be displaced longitudinally in a sleeve 61 and which is pressed against the cam 53 of the crankshaft 43 by means of a spring plate 52 and a piston spring 54, in order to be supported by the eccentric shape of the Cam 53 to move the plunger 51 up and down.
  • the shape of the cam 53 also makes it possible to set the duration of the fuel injection, the power and the speed of the delivery of the fuel injection pump 2.
  • the plunger 51 drives the pump piston 55 in order to convey fuel to the fuel injection valve 3 via a delivery line 60.
  • the pump piston 55 is accommodated in a longitudinally displaceable manner in the pump cylinder 56 along a longitudinal axis 67 running centrally through the pump piston 55 and delimits a pump working chamber 58 in the pump cylinder 56 with an end face 57 located in the pump cylinder 56.
  • the pump piston 55 is fitted into the pump cylinder 56 with extreme accuracy , so that the pump piston 55 even at high pressures and low
  • the pump piston 55 is freely rotatably held at its lower end via a head piece 62 on the plunger 51, the piston spring 54 engaging a head plate 59 in the region of its head piece 62 via the spring plate 52 held on the pump cylinder 56, so that during the working stroke of the pump piston 55 the Piston spring 54 is tensioned.
  • the piston spring 54 leads the pump piston 55 back into its starting position, the piston spring 54 constantly pushing the plunger 51 against the cam 53 so that it does not lift off the cam 53 or make jumps.
  • the pump cylinder 56 and the internal pump piston 55 are accommodated in a housing 70 of the fuel injection pump 2. From the low-pressure pump part 17 shown in FIG. 1, fuel delivered flows via the low-pressure connection 35 to the pump piston 55 shown in FIG. 2 into an annular space 69 located between the housing 70 and the pump cylinder 56 and from there to the control bore 65.
  • the drain bore 66 is, for example, also with the Annulus 69 and connected to the control bore 65 in order to promote the
  • Pump piston 55 discharged fuel, for example, via a drain connection on the housing 70 connected to the drain hole 66 and not shown in the fuel return line 37, in which the fuel flows back to the fuel tank 32.
  • the pump piston 55 has a bore 71 for the control of the fuel, which is recessed centrally in the pump piston 55 and a control edge 73 which is recessed from a lateral surface 72 of the pump piston 55.
  • the control edge 73 is shown partially visible in FIG. 2 and, for example, as a so-called overhead control edge 73 trained.
  • the Bore 71 extends from the end face 57 in the direction of the plunger 51, for example parallel to the longitudinal axis 67 to the control edge 73, which extends obliquely to the longitudinal axis 67.
  • the construction and the mode of operation of a fuel injection pump 2 working with a pump piston 55 with control edge 73 and control bore 65 is known to the person skilled in the art from diesel technology and is therefore only briefly described below.
  • the fuel flowing into the pump work chamber 58 via the control bore 65 is compressed by the pump piston 55 during its upward movement, a pressure valve 85 delimiting the pump work chamber 58 initially remaining closed.
  • a compression spring 87 of the pressure valve 85 acts on a valve closing body 86, for example in the form of a ball, so that a connection 76 from the pump work chamber 58 to a delivery bore 63 provided in a delivery part 77 of the fuel injection pump 2 is closed.
  • valve closing body 86 opens at a pressure which can be predetermined by the compression spring 87, so that fuel passes from the pump work chamber 58 to the connection 76 and past the pressure valve 85 into the delivery bore 63. The fuel then flows from the delivery bore 63 into the delivery line 60 connected to the delivery bore 63 to the fuel injection valve 3.
  • the delivery rate of the fuel injection pump 2 can be adjusted by the rotational position of the control edge 73 of the pump piston 55 to the drain hole 66, the control edge 73, as is known, controlling the point in time at which the fuel that has flowed into the pump working chamber 58 via the control bore 65 ends, so that the delivery stroke of the pump piston 55 and thus the delivery rate can be adjusted by rotating the pump piston 55 or the control edge 73.
  • the Fuel injection pump 2 Fuel with a pressure of approximately 35 bar into the delivery line 60 to the fuel injection valve 3.
  • a rotatable one serves to rotate the pump piston 55
  • Control element 80 which is designed, for example, in the form of a control sleeve partially encompassing the pump piston 55.
  • the control element 80 is pressed against the pump cylinder 56 by the piston spring 54 and the spring plate 52.
  • the connection of the control element 80 to the pump piston 55 is designed such that an axial displacement of the pump piston 55 is always possible, whereas when the control element 80 is rotated, the pump piston 55 also rotates.
  • two longitudinal slots are worked out from an inner wall of the control element 80, in which a piston driver 74, a so-called piston vane, is guided in an axially sliding manner, which acts upon the longitudinal slots of the control element 80 when rotating, in order to effect a corresponding rotation of the pump piston 55.
  • the control element 80 has an engagement groove 83 on its outer surface 81 that extends into the plane of the drawing in FIG. 3 and, for example, at least partially in the direction of FIG Longitudinal axis 67 runs.
  • An engagement body 84 which is connected to a control rod 82, engages in the engagement groove 83.
  • the control rod 82 extends inside the housing 70 of the fuel injection pump 2, offset from the control element 80, along a transverse axis 68 running transversely to the longitudinal axis 67.
  • the engagement body 84 is designed, for example, in the form of a spherical head or a pin and is located on an outer surface 88 of the control rod 82 onwards.
  • the engagement body 84 engages in the engagement groove 83 of the control element 80 in order to Displacement of the control rod 82 to cause rotation of the control element 80 and the pump piston 55.
  • the control rod 82 is mounted inside the housing 70 of the fuel injection pump 2 by means of two bearings 91, 92, for example plain bearings. As shown in FIG. 3, the control rod 82 is fastened with its left end 93 to a membrane 94 of an adjusting device 90. The membrane 94 separates two pressure spaces from one another in a pressure-tight manner. In the following, the one on the left in FIG.
  • the connection pressure chamber 96 is connected to a pulse pressure line 100 via a pulse pressure connection 99.
  • Control pressure chamber 97 is connected, for example, to the atmosphere via an opening 101 provided in the control pressure chamber 97 and via a filter 102 provided in the opening 101 in the housing 70 with a connection not shown in FIG. Like in
  • the opening 101 can also be connected via a connection, not shown, with a start pressure line 104, which leads to a starting device 105, the task and function of which will be explained in more detail later in the embodiment.
  • a connector 106 is attached on both sides of the membrane 94, which is connected to an end piece of the control rod 82 located in the signal pressure chamber 97.
  • a pair of bimetallic disks 107 is provided, which comprises an end region of the control rod 82 and is pressed onto the connector 106 by a spring plate 108 by means of a compression spring 109.
  • the pair of bimetallic disks 107 is exposed For example, two metal disks connected to each other, which are different
  • the compression spring 109 is supported via the spring plate 108 and the bimetallic disk pair 107 with the connector 106 on one side of the membrane 94 and on the opposite side via a support ring 110 on a shoulder 103.
  • the shoulder 103 is formed in the area of the bearing 91 shown in FIG. 3 in the signal pressure space 97.
  • the diaphragm 94 is acted upon by the compression spring 109 in such a way that it rests at approximately equal pressures in the connection pressure chamber 96 and in the control pressure chamber 97 with the connector 106 located in the connection pressure chamber 96 on an idle adjustment screw 111 protruding into the connection pressure chamber 96.
  • connection pressure chamber 96 When the connection pressure chamber 96 is pressurized with a higher pressure than that prevailing in the signal pressure chamber 97
  • the diaphragm 94 is moved to the right in FIG. 3 against the force of the compression spring 109, so that the connection piece 106 located in the connection space 96 lifts off an end of the idle adjustment screw 111 which projects into the connection pressure space 96.
  • the control rod 82 connected to the membrane 94 is shifted to the right, the engagement body 84 rotating the control element 80 counterclockwise and rotating the pump piston 55 shown in FIG. 2, thereby reducing the delivery rate of the
  • Unscrewing the idle adjustment screw 111 can therefore the minimum injection quantity of the fuel injection pump 2 is adjusted, or the idle speed of the two-stroke internal combustion engine is adjusted.
  • the second bearing 92 is accommodated at an end 95 of the control rod 82 shown on the right in FIG. 3 in the housing 70 of the fuel injection pump 2 and is held by a screwable bearing sleeve 112.
  • the bearing sleeve 112 has an external thread on its outer surface in order to be screwed into the housing 70 in an internal thread which extends from an end face 114 of the housing 70 in the direction of the control element 80 beyond the bearing 92.
  • the axial clearance 118 is required to enable the control rod 82 to move along the transverse axis 68.
  • An adjusting screw 119 which is screwed into a thread of the end piece 116 of the bearing sleeve 112, projects into the free space 118 and is held against rotation by a lock nut 120 on the end piece 116 of the bearing sleeve 112.
  • the adjusting screw 119 is provided in order to limit a maximum displacement of the control rod 82 in the direction of the transverse axis 68, which occurs when the connection pressure chamber 96 is subjected to a maximum pressure. 3 and 4, the control rod 82 is shifted to the right until the control rod 82 abuts the adjusting screw 119 with its right end 95 with an end face 98, so that the adjusting screw 119 is screwed in or out maximum displaceable path of the
  • the clamping length of the compression spring 109 is shortened, which results in an increased spring force of the compression spring 109, so that a greater pressure difference between the overpressure in the connection pressure chamber 96 and the ambient pressure in the signal pressure chamber 97 is necessary in order to displace the control rod 82.
  • the pair of bimetallic disks 107 causes a reduced displacement of the control rod 82 with a constant pressure difference in the connection pressure chamber 96 when the temperature in the connection pressure chamber 96 increases, for example due to a temperature increase in the interior 10 of the crankcase 11 (FIG. 1) or when the temperature in the control pressure chamber 97 increases, for example due to an increasing ambient temperature and signal pressure chamber 97, so that correspondingly less fuel is conveyed from the fuel injection pump 2 to the fuel injection valve 3.
  • the control pressure chamber 97 shown in FIGS. 3 and 4 is connected in the exemplary embodiment to the starting device 105 shown in FIG. 1 by means of a connection on the housing 70 of the fuel injection pump 2, which is not shown in detail.
  • the starting device 105 is connected via a connection pressure line 115 to the intake pipe 9 downstream of a throttle valve 20.
  • the throttle valve 20 is known to serve for power control of the two-stroke internal combustion engine 4 and is pivotally mounted about a shaft in the intake pipe 9.
  • the throttle valve 20 can be actuated, for example, by means of a linkage, not shown in more detail, for example using an accelerator pedal or using an accelerator lever.
  • the starting device 105 is only switched on manually, for example, only in the cold start phase of the two-stroke internal combustion engine 4, by which the two-stroke Brennkraftma ⁇ chine 4 in the intake pipe 9 negative pressure via the connection pressure line 115 to the starting device 105 and from there via the starting pressure line 104 to the control pressure chamber 97 of the adjusting device 90.
  • Ambient pressure prevailing in the control pressure chamber 97 consequently results in a higher pressure difference between the overpressure in the connection pressure chamber 96 and the vacuum in the control pressure chamber 97, as a result of which the control rod 82 is deflected to a greater extent, so that the delivery quantity of the fuel injection pump 2 is increased when the starting device 105 is actuated.
  • the starting device 105 can be switched off again.
  • the starting pressure line 104 is switched to the environment, so that ambient pressure is again set in the signal pressure chamber 97, which reduces the delivery rate of the fuel injection pump 2 after the cold start phase.
  • the control opening 125 is excluded from the cylinder inner wall 41 of the cylinder 5.
  • a piston opening 127 which has a connection to the interior 10 of the crankcase 11, is excluded from a piston peripheral wall 126 of the piston 6.
  • the control opening 125 and the piston opening 127 open into one another, so that the internal pressure in the interior 10 of the crankcase 11 is supplied via the pulse pressure line 100 to the connection pressure chamber 96 of the adjusting device 90.
  • valve 128 Since the piston 6 generates a negative pressure in the interior 10 of the crankcase 11 during the upward movement in the direction of its top dead center (TDC), which should not be supplied to the connection pressure chamber 96, a valve 128 is required which detects the negative pressure component of the pulsating internal pressure in Crankcase 11 cuts off.
  • the valve 128 is arranged, for example, in the pulse pressure line 100 and, in the event of overpressure in the pulse pressure line 100, assumes an open position during the downward movement of the piston 6 in the direction of its bottom dead center (UT) and is otherwise closed.
  • a specific range of the internal pressure in the crankcase 11, for example 15 ° to 60 ° before reaching bottom dead center (UT) of the piston 6, can be selected and via the control opening 125 and the impulse line 100 Connection pressure chamber 96 are supplied.
  • the overpressure of the crankcase 11 supplied to the connection pressure chamber 96 exceeds the ambient pressure in the control pressure chamber 97, so that the membrane 94 of the adjusting device 90 is moved in the direction of the pressure drop.
  • the moved diaphragm 94 moves the control rod 82 to the right in FIGS. 3 and 4, the control element 80 being rotated.
  • the delivery quantity of the fuel injection pump 2 can be finely metered. Since only the pressure difference between the overpressure in the crankcase 11 and the ambient pressure is used to control the delivery rate of the fuel injection pump 2, the influence of changing ambient pressure, for example due to a geodetic change in height, can be compensated for by a corresponding change in the delivery rate of the fuel injection pump 2.
  • the selection of the position of the control opening 125 in the cylinder 5, or the position of the correspondingly arranged piston opening 127, has to be carried out in such a way that a wide operating range of the two-stroke internal combustion engine 4 characterizing internal pressure is found in the crankcase 11, in which the delivery quantity which is always optimally adapted means that Fuel injection pump 2 a perfect one Operating behavior of the two-stroke internal combustion engine 4 with optimal combustion and low exhaust emissions is possible. It has been found that this is possible with a control opening 125, which is taken out of the cylinder inner wall 41 approximately in the peripheral region of the suction pipe 9.
  • control openings may also be advantageous to provide a plurality of control openings at different locations on the cylinder inner wall 41, which are arranged, for example, along a common line in order to be actuated by a common piston opening or also a plurality of piston openings. It is also conceivable to provide a plurality of control openings in the cylinder inner wall 41, which can be actuated in part at the same time or in succession by correspondingly provided piston openings.
  • FIG. 4 shows a second exemplary embodiment according to the invention of fuel injection device 1 with fuel injection pump 2, all the same or equivalent parts being identified by the same reference numerals from FIGS. 1 to 3.
  • the compression spring 109 in FIG. 4 is accommodated in the area of the right end 95 of the control rod 82.
  • the right-hand bearing 92 is accommodated in a bearing recess 137 provided in the housing 70.
  • a spring plate 135, on which the compression spring 109 is supported, is connected to the right end 95 of the control rod 82.
  • the compression spring 109 is housed in a stepped sleeve 132, which with a
  • the compression spring 109 partially includes the adjusting screw 119 accommodated in the sleeve 132 and is supported with a support ring 131 against the pair of bimetallic disks 107, which, compared to the first embodiment, is accommodated in an interior space 136 formed by the sleeve 132 and by a screw-in part 138 of the sleeve 132.
  • the pair of bimetallic disks 107 is supported against the screw-in part 138 which, for example, by means of an internal thread into the
  • Sleeve 132 is screwed.
  • the adjusting screw 119 is also screwed into an internal thread provided on the screw-in part 138 and is held against rotation by means of a lock nut 120.
  • the free space 118 can be changed by screwing the adjusting screw 119 in or out, so that the maximum displacement of the control rod 82 can be adjusted by means of the adjusting screw 119.

Abstract

With prior art two-stroke fuel-injection systems, which inject the fuel directly into the combustion chamber by means of a fuel-injection valve, the engine operating parameters which affect the amount of fuel delivered by the fuel-injection pump can only be modified with difficulty and this requires additional equipment to be fitted. The fuel-injection system (1) proposed for a two-stroke engine (4) has a fuel-injection pump (2) with an adjustment device (90) to which the pulsating pressure in the interior (10) of the engine crankcase (11) is fed through an impulse pressure line (100) in order to meter the amount of fuel delivered by the pump in dependence on the pressure in the crankcase, thus ensuring that the optimum amount of fuel is delivered for combustion and hence reducing the exhaust-gas emission and fuel consumption of the engine. This fuel injection system is intended for use in two-stroke internal-combustion engines.

Description

B_:e--nstgffeinsp_ritzvQrrichtU--g für eine Zweitakt- BrennkraftmaschineB_: e - nstgffeinsp_ritzvQrrichtU - g for a two-stroke internal combustion engine
Stand der TechnikState of the art
Die Erfindung geht aus von einerThe invention is based on one
Brennstoffeinspritzvorrichtung nach der Gattung des Anspruchs 1. Es ist schon eineFuel injection device according to the preamble of claim 1. It is already one
Brennstoffeinspritzvorrichtung für eine Zweitakt- Brennkraftmaschine bekannt (Sonderdruck aus MTZ, Motortechnische Zeitschrift, Jahrgang 13, Heft 10, Oktober 1952) , bei der eine Brennstoffeinspritzpumpe Brennstoff zu einem direkt in einen Brennraum der Zweitakt- Brennkraftmaschine einspritzenden Brennstoffeinspritzventil fördert. Die Brennstoffeinspritzpumpe ist in sogenannter Reihenpumpenbauart ausgebildet, bei der jeder Zylinder der Zweitakt-Brennkraftmaschine über ein separates Pumpenelement mit Brennstoff versorgt wird. Das Pumpenelement setzt sich aus einem Pumpenkolben und einem Pumpenzylinder zusammen. Der Pumpenkolben ist in dem Pumpenzylinder längsverschiebbar geführt und über ein Antriebselement von einer Nockenwelle der Zweitakt-Brennkraftmaschine angetrieben. Zum Steuern der Leistung der Zweitakt-Brennkraftmaschine wird eine in einem Drosselklappenstutzen drehbar gelagerte Drosselklappe betätigt, wozu ein Gestänge an der Drosselklappe vorgesehen ist, das mit einem Gaspedal oder mit einem Gashebel verbunden ist. Beim Betrieb der Zweitakt-Brennkraftmaschine stellt sich im Drosselklappenstutzen ein bestimmter Unterdruck ein, der von der Drehstellung der Drosselklappe abhängt, so daß dieser zur Regelung der Fördermenge der Brennstoffeinspritzpumpe herangezogen werden kann. Im angegebenen Stand der Technik wird der Unterdruck stromabwärts der Drosselklappe entnommen und über eine Impulsdruckleitung zu einer Versteileinrichtung geführt. Die VerStelleinrichtung ist Teil der Brennstoffeinspritzpumpe und regelt abhängig von dem im Drosselklappenstutzen herrschenden Unterdruck die Fördermenge der Brennstoffeinspritzpumpe. Zum Andern der Fördermenge wird der Pumpenkolben gedreht, der an seiner äußeren Mantelfläche eine Ausnehmung besitzt, die in Form einer schräg verlaufenden Steuerkante ausgebildet ist. Der Pumpenkolben steuert mittels der Steuerkante eine im Pumpenzylinder ausgenommene und in einen Pumpenarbeitsraum des Pumpenkolbens mündende Steuerbohrung ab, wobei die Drehlage der Steuerkante bezüglich der Steuerbohrung das Fδrderende des Pumpenkolbens bestimmt. Durch die Lage des Pumpenkolbens im Pumpenzylinder wird der Nutzhub und damit die Fördermenge verändert.Fuel injection device for a two-stroke internal combustion engine is known (special print from MTZ, Motortechnische Zeitschrift, Volume 13, Issue 10, October 1952), in which a fuel injection pump delivers fuel to a fuel injector that injects directly into a combustion chamber of the two-stroke internal combustion engine. The fuel injection pump is designed in a so-called in-line pump type, in which each cylinder of the two-stroke internal combustion engine is supplied with fuel via a separate pump element. The pump element is composed of a pump piston and a pump cylinder. The pump piston is guided in a longitudinally displaceable manner in the pump cylinder and is driven by a camshaft of the two-stroke internal combustion engine via a drive element. To control the power of the two-stroke internal combustion engine, a throttle valve rotatably mounted in a throttle valve neck is actuated, for which purpose a linkage is provided on the throttle valve, which is connected to an accelerator pedal or a throttle lever. When the two-stroke internal combustion engine is operating, a certain negative pressure is established in the throttle valve neck, which depends on the rotational position of the throttle valve, so that it can be used to regulate the delivery rate of the fuel injection pump. in the State of the art specified, the vacuum is taken downstream of the throttle valve and led to an adjusting device via a pulse pressure line. The adjustment device is part of the fuel injection pump and regulates the delivery rate of the fuel injection pump depending on the negative pressure prevailing in the throttle valve connector. To change the delivery rate, the pump piston is rotated, which has a recess on its outer lateral surface, which is designed in the form of an obliquely extending control edge. The pump piston uses the control edge to control a control bore that is recessed in the pump cylinder and opens into a pump working chamber of the pump piston, the rotational position of the control edge with respect to the control bore determining the delivery end of the pump piston. The position of the pump piston in the pump cylinder changes the useful stroke and thus the delivery rate.
Zum Drehen des Pumpenkolbens ist ein hülsenfδrmiges Regelelement vorgesehen, das in seinem Inneren eine zwei Längsschlitze aufweisende Öffnung hat, an denen ein am Pumpenkolben ausgebildeter Mitnehmer, beispielsweise in Form einer Kolbenfahne, axial verschiebbar gleitet und nur bei einer Drehung des Regelelements an den Längsschlitzen zum Drehen des Pumpenkolbens angreift. Zum Betätigen des Regelelements besitzt dieses beispielsweise an seiner Außenfläche ein angeklemmtes Zahnsegment, an dem eine quer zu einer Längsachse des Pumpenkolbens im Gehäuse der Brennstoffeinspritzpumpe untergebrachte Regelstange mit einer Außenverzahnung eingreift, um bei einerTo rotate the pump piston, a sleeve-shaped control element is provided which has an opening in its interior with two longitudinal slots, on which a driver formed on the pump piston, for example in the form of a piston vane, slides axially and only rotates on the longitudinal slots when the control element is rotated of the pump piston attacks. To actuate the control element, the latter has, for example, a clamped tooth segment on its outer surface, on which a control rod, which is accommodated transversely to a longitudinal axis of the pump piston in the housing of the fuel injection pump, engages with an external toothing in order to
LängsVerschiebung der RegelStange eine Drehung des Regelelements und des Pumpenkolbens zu bewirken. Im angegebenen Stand der Technik ist die Regelstange mit ihrem einen Ende an einer Membran einer Versteileinrichtung angebracht, die abhängig vom Unterdruck im Drosselklappenstutzen die Fördermenge der Brennstoffeinspritzpumpe bestimmt. Hierzu trennt die Membran der VerStelleinrichtung zwei Druckräume, einen Anschlußdruckraum und einen Stelldruckraum, druckdicht voneinander ab, so daß bei einer Druckdifferenz zwischen Anschlußdruckraum und Stelldruckraum die Membran in Richtung des Druckgefälles bewegt wird. Bei sich bewegender Membran wird die an der Membran angebrachte Regelstange verschoben, wobei gleichzeitig das Regelelement gedreht wird, um eine Verstellung der Fördermenge der Brennstoffeinspritzpumpe zu bewirken. Im angegebenen Stand der Technik wird der Stelldruckraum mit Umgebungsdruck und der Anschlußdruckraum mit Unterdruck des Drosselklappenstutzens beaufschlagt, so daß abhängig von der an der Membran anliegenden Druckdifferenz eine Verschiebung der Regelstange und über das Regelelement eine Drehung des Pumpenkolbens erfolgt.Longitudinal displacement of the control rod to cause rotation of the control element and the pump piston. In the stated prior art, the control rod is attached at one end to a diaphragm of an adjusting device which, depending on the negative pressure in the throttle valve connector, the delivery rate of the Fuel injection pump determined. For this purpose, the membrane of the adjusting device separates two pressure chambers, a connection pressure chamber and a signal pressure chamber, from one another in a pressure-tight manner, so that the membrane is moved in the direction of the pressure drop if there is a pressure difference between the connection pressure chamber and the signal pressure chamber. When the diaphragm moves, the control rod attached to the diaphragm is displaced, the control element being rotated at the same time in order to adjust the delivery rate of the fuel injection pump. In the stated prior art, the control pressure chamber is pressurized with ambient pressure and the connection pressure chamber with negative pressure of the throttle valve connector, so that depending on the pressure difference applied to the diaphragm, the control rod is displaced and the pump piston rotates via the control element.
Bei der beschriebenen Leistungsregelung der Zweitakt- Brennkraftmaschine mittels des Unterdrucks im Drosselklappenstutzen, ist jedoch nur äußerst aufwendig eine Anpassung der Fördermenge an sich ändernde Betriebsgrößen der Zweitakt-Brennkraftmaschine möglich. Hierzu sind zusätzliche Vorrichtungen notwendig. Beispielsweise kann der Einfluß des sich bei steigender geodätischer Höhenlage abnehmenden Umgebungsdrucks und damit abnehmender Luftfüllung der Zylinder der Zweitakt-Brennkraftmaschine nur mittels einem zusätzlichen Hδhendruckfühler erfaßt werden. Weiterhin kann der Temperatureinfluß der von der Zweitakt- Brennkraftmaschine angesaugten Luft nur mittels eines Temperaturfühlers erfaßt werden, der in Verbindung mit der Brennstoffeinspritzpumpe die Fördermenge der Lufttemperatur entsprechend anpaßt. Üblicherweise wird der Temperaturfühler außerhalb der Brennstoffeinspritzpumpe im Drosselklappenstutzen untergebracht. Der Temperaturfühler ist mittels eines Gestänges mit der Regelstange der Brennstoffeinspritzpumpe verbunden, um diese abhängig von der Temperatur der angesaugten Luft ausgleichend zu betätigen, so daß eine Anpassung der Fördermenge an unterschiedliche Ansauglufttemperaturen erfolgt.In the described power control of the two-stroke internal combustion engine by means of the negative pressure in the throttle valve connector, however, it is only possible to adapt the delivery rate to changing operating parameters of the two-stroke internal combustion engine in an extremely complex manner. Additional devices are required for this. For example, the influence of the ambient pressure decreasing with increasing geodetic altitude and thus decreasing air filling of the cylinders of the two-stroke internal combustion engine can only be detected by means of an additional altitude pressure sensor. Furthermore, the temperature influence of the air drawn in by the two-stroke internal combustion engine can only be detected by means of a temperature sensor which, in conjunction with the fuel injection pump, adapts the delivery rate to the air temperature accordingly. The temperature sensor is usually housed outside the fuel injection pump in the throttle valve connector. The temperature sensor is connected to the control rod of the fuel injection pump by means of a linkage in order to compensate for this depending on the temperature of the air drawn in press so that the flow rate is adjusted to different intake air temperatures.
Vorteile der ErfindungAdvantages of the invention
Die erfindungsgemäße Brennstoffeinspritzvorrichtung mit den kennzeichnenden Merkmalen des Anspruchs 1 hat demgegenüber den Vorteil, daß in einfacher Art und Weise eine Anpassung der Fördermenge der Brennstoffeinspritzpumpe an sich ändernde Betriebsgrößen der Zweitakt-Brennkraftmaschine erfolgt, wobei sich insbesondere die Anteile schädlicher Abgasbestandteile und der Verbrauch der Zweitakt- Brennkraftmaschine deutlich reduzieren.The fuel injection device according to the invention with the characterizing features of claim 1 has the advantage that the delivery rate of the fuel injection pump can be easily adapted to changing operating parameters of the two-stroke internal combustion engine, the proportions of harmful exhaust gas components and the consumption of the two-stroke engine in particular Reduce the internal combustion engine significantly.
Durch die in den Unteransprüchen aufgeführten Maßnahmen sind vorteilhafte Weiterbildungen und Verbesserungen der im Anspruch 1 angegebenen Brennstoffeinspritzvorrichtung möglich. Vorteilhaf erweise ermöglicht eine im Kaltstart der Zweitakt-Brennkraftmaschine zuschaltbare Starteinrichtung eine weitere Senkung der schädlichen Abgasbestandteile.Advantageous further developments and improvements of the fuel injection device specified in claim 1 are possible through the measures listed in the subclaims. Advantageously, a start device that can be activated in the cold start of the two-stroke internal combustion engine enables a further reduction in the harmful exhaust gas components.
Zeichnungdrawing
Ausführungsbeispiele der Erfindung sind in der Zeichnung vereinfacht dargestellt und in der nachfolgendenEmbodiments of the invention are shown in simplified form in the drawing and in the following
Beschreibung näher erläutert. Es zeigen Figur 1 ein schematisches Funktionsbild einer erfindungsgemäßen Brennstoffeinspritzvorrichtung, Figur 2 einen Schnitt durch eine Brennstoffeinspritzpumpe gemäß einem ersten erfindungsgemäßen Ausführungsbeiεpiel, Figur 3 einen Schnitt durch die Brennstoffeinspritzpumpe entlang einer Linie XII- III 'in Figur 2, Figur 4 einen Schnitt durch die Brennstoffeinspritzpumpe gemäß einem zweiten erfindungsgemäßen Ausführungsbeispiel. Beschreibung der AusführungsbeispieleDescription explained in more detail. 1 shows a schematic functional diagram of a fuel injection device according to the invention, FIG. 2 shows a section through a fuel injection pump according to a first exemplary embodiment according to the invention, FIG. 3 shows a section through the fuel injection pump along a line XII-III ' in FIG. 2, FIG. 4 shows a section through the fuel injection pump according to FIG a second embodiment of the invention. Description of the embodiments
In der Figur 1 ist ein εchematisches Funktionsbild einer erfindungsgemäßen Brennstoffeinspritzvorrichtung 1 gezeigt, bei der eine Brennstoffeinspritzpumpe 2 zurFIG. 1 shows a schematic functional diagram of a fuel injection device 1 according to the invention, in which a fuel injection pump 2 is used
Brennstoffversorgung einer im Schnitt teilweise dargestellten Zweitakt-Brennkraftmaschine 4 vorgesehen ist. Die Brennstoffeinspritzpumpe 2 fördert Brennstoff zu einem an einem Zylinder 5 der Zweitakt-Brennkraftmaschine 4 vorgesehenen Brennstoffeinspritzventil 3, das den Brennstoff direkt in einen Brennraum 12 der Zweitakt-Brennkraftmaschine 4 einspritzt. Die Zweitakt-Brennkraftmaschine 4 saugt dabei über ein Ansaugrohr 9 die zur Verbrennung notwendige Verbrennungsluft in einen Innenraum 10 eines Kurbelgehäuses 11 der Zweitakt-Brennkraftmaschine, aus dem sie über nicht näher dargestellte Überstrδmkanäle, von einem im Zylinder 5 verschiebbar untergebrachten Kolben 6 gesteuert, in den Brennraum 12 eintrit . Die bei der Verbrennung entstehenden Abgase werden über einen Auslaßkanal 14 aus dem Brennraum 12 abgeführt. Die Zweitakt-Brennkraftmaschine 4 ist beispielsweise zum Antrieb handgeführter Antriebsgeräte, wie Motorkettensägen, Trennschleifer, Freischneidegeräte sowie von Mopeds, Motorbooten und Rasenmäher oder dergleichen vorgesehen. Eine Brennstoffvorfδrderpumpe 15 liefert Brennstoff zur Brennstoffeinspritzpumpe 2 und setzt sich, wie in der Figur 1, innerhalb einer gestrichelt dargestellten Linie gezeigt ist, aus einemFuel supply to a two-stroke internal combustion engine 4 partially shown in section is provided. The fuel injection pump 2 delivers fuel to a fuel injection valve 3 provided on a cylinder 5 of the two-stroke internal combustion engine 4, which injects the fuel directly into a combustion chamber 12 of the two-stroke internal combustion engine 4. The two-stroke internal combustion engine 4 sucks the combustion air required for combustion into an interior 10 of a crankcase 11 of the two-stroke internal combustion engine via an intake pipe 9, from which it is controlled by a piston 6, which is displaceably accommodated in the cylinder 5, by means of overflow channels (not shown) Combustion chamber 12 enters. The exhaust gases produced during the combustion are discharged from the combustion chamber 12 via an outlet duct 14. The two-stroke internal combustion engine 4 is provided, for example, for driving hand-held drive devices, such as motor chain saws, cut-off machines, brush cutters and mopeds, motor boats and lawn mowers or the like. A fuel feed pump 15 supplies fuel to the fuel injection pump 2 and, as shown in FIG. 1, is shown within a dashed line
Niederdruckpumpenteil 17 und einem dem Niederdruckpumpenteil 17 vorgeschalteten Saugpuffer 18 zusammen. Die Brennstoffvorfδrderpumpe 15 wird vom im Innenraum 10 desLow-pressure pump part 17 and a suction buffer 18 connected upstream of the low-pressure pump part 17. The fuel feed pump 15 is located in the interior 10 of the
Kurbelgehäuses 11 pulsierenden Innendruck im Kurbelgehäuse 11 der Zweitakt-Brennkraftmaschine 4 angetrieben, wozu eine Druckleitung 26 vorgesehen ist, die von einem von einer Membran 24 begrenzten Arbeitsraum 25 des Niederdruckpumpenteils 17 zum Innenraum 10 desCrankcase 11 driven pulsating internal pressure in the crankcase 11 of the two-stroke internal combustion engine 4, for which purpose a pressure line 26 is provided, which from a working space 25 delimited by a membrane 24 of the low-pressure pump part 17 to the interior 10 of the
Kurbelgehäuses 11 führt. Die Membran 24 steuert über einen Stößel 27 eine Pumpenmembran 28, die eine Pumpenkammer 29 begrenzt. Die Pumpenkammer 29 steht über ein Saugventil 30 mit einem BrennstoffZulauf 31 in Verbindung, der aus einem Brennstoffbehälter 32 den Brennstoff zuführt. Ober ein Druckventil 33 und eine Niederdruckleitung 34 wird derCrankcase 11 leads. The membrane 24 controls one Ram 27 a pump diaphragm 28 which delimits a pump chamber 29. The pump chamber 29 is connected via a suction valve 30 to a fuel inlet 31 which supplies the fuel from a fuel tank 32. Via a pressure valve 33 and a low pressure line 34, the
Brennstoff in Richtung eingezeichneter Pfeile 39 zu einem Niederdruckanschluß 35 der Brennstoffeinspritzpumpe 2 geführt, wobei von dem Niederdruckpumpenteil 17 überschüssig geförderter Brennstoff in Richtung eingezeichneter Pfeile 40 in einer vorgesehenen Brennstoffrücklaufleitung 37 über ein Rücklaufventil 36 von der Brennstoffeinspritzpumpe 2 zum Brennstoffbehälter 32 zurückströmt.Fuel is guided in the direction of the arrows 39 to a low-pressure connection 35 of the fuel injection pump 2, excess fuel conveyed from the low-pressure pump part 17 flowing in the direction of the arrows 40 in a provided fuel return line 37 via a return valve 36 from the fuel injection pump 2 to the fuel tank 32.
Die Brennstoffeinspritzpumpe 2 und das Brennstoffeinspritzventil 3 entsprechen in ihrem prinzipiellen Aufbau bekannter Dieseltechnologie. Da der Brennstoff nicht mehr über einen sonst üblichen Vergaser in das Ansaugrohr 9 in Form eines mit Öl vermischten Brennstoff-Luft-Gemisches in den Brennraum 12 eingeführt wird, sondern direkt in den Brennraum 12 eingespritzt wird und daher nicht mehr mit einer Zylinderinnenwand 41 der Zweitakt-Brennkraftmaschine 4 in Berührung kommt, ist eine Schmierδlpumpe 42 erforderlich. Die Schmierδlpumpe 42 fördert Öl zum Kurbelwellenlager, Pleuellager, Kolbenbolzenauge und insbesondere an die Zylinderinnenwand 41. Die Schmierδlpumpe 42 wird beispielsweise von einer in der Figur 1 gestrichelt dargestellten Kurbelwelle 43 der Zweitakt-Brennkraftmaschine 4 angetrieben, welche über ein Pleuel 44 die Auf- und Abwärtsbewegung des Kolbens 6 in eine Drehbewegung der Kurbelwelle 43 wandelt. Die Schmierδlpumpe 42 besitzt zum Pumpen des Öls eine Förderschnecke, die an ihrem Ende beispielsweise eine Kegelverzahnung hat. Die Kegelverzahnung greift in eine an der Kurbelwelle 43 vorgesehene StimVerzahnung ein, um das Öl mittels der Förderschnecke aus einem Ölbehälter 45 und beispielsweise vorgesehene Ölfilter 46 über ein Druckventil 47 zu fördern. In den Ausführungsbeispielen ist die Brennstoffein¬ spritzpumpe 2 als sogenannte Steckeinspritzpumpe ausgebildet. Wie in der Figur 2 dargestellt ist, bilden ein Pumpenkolben 55 und ein Pumpenzylinder 56 ein einzelnes Pumpenelement, welches den Brennstoff zur beispielsweise einzylindrig ausgebildeten Zweitakt-Brennkraftmaschine 4 fördert. Es ist auch möglich, die Brennstoffeinspritzpumpe in sogenannter Reihenpumpenbauart auszubilden, bei der für jeden Zylinder ein einzelnes Pumpenelement vorgesehen ist, welche in Reihe hintereinanderliegend angeordnet in einem gemeinsamen Gehäuse untergebracht werden. Wie in der Figur 1 dargestellt ist, wird die Brennstoffeinspritzpumpe 2 in bekannter Weise von einem an der Kurbelwelle 43 angebrachten Nocken 53 über ein Antriebselement 50 der Brennstoffeinspritzpumpe 2 angetrieben. Wie in der Figur 2 dargestellt ist, setzt sich das Antriebselement 50 aus einem in einer Hülse 61 längsverεchiebbaren Stδßel 51 zusammen, der über einen Federteller 52 und über eine Kolbenfeder 54 an den Nocken 53 der Kurbelwelle 43 angedrückt wird, um durch die exzentrische Form des Nockens 53 den Stößel 51 auf- und abwärts zu bewegen. Durch die Formgebung des Nockens 53 ist es weiterhin möglich, die Dauer der Brennstoffeinspritzung, die Leistung und die Geschwindigkeit der Förderung der Brennstoffeinspritzpumpe 2 einzustellen.The basic structure of the fuel injection pump 2 and the fuel injection valve 3 correspond to known diesel technology. Since the fuel is no longer introduced into the intake pipe 9 in the form of an oil-mixed fuel-air mixture in the combustion chamber 12 via an otherwise conventional carburetor, but is instead injected directly into the combustion chamber 12 and therefore no longer with a cylinder inner wall 41 of the two-stroke cycle Internal combustion engine 4 comes into contact, a lubricating oil pump 42 is required. The lubricating oil pump 42 delivers oil to the crankshaft bearing, connecting rod bearing, piston pin eye and, in particular, to the cylinder inner wall 41. The lubricating oil pump 42 is driven, for example, by a crankshaft 43 of the two-stroke internal combustion engine 4 shown in dashed lines in FIG of the piston 6 converts into a rotary movement of the crankshaft 43. The lubricating oil pump 42 has a screw conveyor for pumping the oil, which has, for example, a bevel gear at its end. The bevel toothing engages in a spline toothing provided on the crankshaft 43 in order to convey the oil out of an oil container 45 by means of the screw conveyor and, for example, provided oil filter 46 via a pressure valve 47. In the exemplary embodiments, the fuel injection pump 2 is designed as a so-called plug-in injection pump. As shown in FIG. 2, a pump piston 55 and a pump cylinder 56 form a single pump element which conveys the fuel to the two-stroke internal combustion engine 4, for example, a single-cylinder engine. It is also possible to design the fuel injection pump in a so-called in-line pump type, in which a single pump element is provided for each cylinder, which are arranged in series in a common housing. As shown in FIG. 1, the fuel injection pump 2 is driven in a known manner by a cam 53 attached to the crankshaft 43 via a drive element 50 of the fuel injection pump 2. As shown in FIG. 2, the drive element 50 is composed of a plunger 51 which can be displaced longitudinally in a sleeve 61 and which is pressed against the cam 53 of the crankshaft 43 by means of a spring plate 52 and a piston spring 54, in order to be supported by the eccentric shape of the Cam 53 to move the plunger 51 up and down. The shape of the cam 53 also makes it possible to set the duration of the fuel injection, the power and the speed of the delivery of the fuel injection pump 2.
Der Stδßel 51 treibt den Pumpenkolben 55 an, um Brennstoff über eine Fδrderleitung 60 zum Brennstoffeinspritzventil 3 zu fördern. Hierzu ist der Pumpenkolben 55 entlang einer mittig durch den Pumpenkolben 55 verlaufenden Längsachse 67 längsverschiebbar im Pumpenzylinder 56 untergebracht und begrenzt mit einer im Pumpenzylinder 56 gelegenen Endstirnfl che 57 einen Pumpenarbeitsraum 58 im Pumpenzylinder 56. Der Pumpenkolben 55 ist mit äußerster Genauigkeit in den Pumpenzylinder 56 eingepaßt, so daß der Pumpenkolben 55 selbst bei hohen Drücken und niedrigenThe plunger 51 drives the pump piston 55 in order to convey fuel to the fuel injection valve 3 via a delivery line 60. For this purpose, the pump piston 55 is accommodated in a longitudinally displaceable manner in the pump cylinder 56 along a longitudinal axis 67 running centrally through the pump piston 55 and delimits a pump working chamber 58 in the pump cylinder 56 with an end face 57 located in the pump cylinder 56. The pump piston 55 is fitted into the pump cylinder 56 with extreme accuracy , so that the pump piston 55 even at high pressures and low
Drehzahlen der Zweitakt-Brennkraftmaschine 4 dichthält und keine weitere Dichtung nötig ist. Der Pumpenkolben 55 ist an seinem unteren Ende über ein Kopfstück 62 am Stδßel 51 frei drehbar gehalten, wobei die Kolbenfeder 54 über den am Pumpenzylinder 56 gehaltenen Federteller 52 an einem Kopfteller 59 im Bereich seines Kopfstücks 62 angreift, so daß beim Arbeitshub des Pumpenkolbens 55 die Kolbenfeder 54 gespannt wird. Die Kolbenfeder 54 führt nach dem Arbeitshub den Pumpenkolben 55 wieder in seine Ausgangslage zurück, wobei die Kolbenfeder 54 den Stδßel 51 dauernd gegen den Nocken 53 drückt, so daß dieser nicht vom Nocken 53 abhebt oder Sprünge macht.Speeds of the two-stroke engine 4 keeps tight and no further sealing is necessary. The pump piston 55 is freely rotatably held at its lower end via a head piece 62 on the plunger 51, the piston spring 54 engaging a head plate 59 in the region of its head piece 62 via the spring plate 52 held on the pump cylinder 56, so that during the working stroke of the pump piston 55 the Piston spring 54 is tensioned. After the working stroke, the piston spring 54 leads the pump piston 55 back into its starting position, the piston spring 54 constantly pushing the plunger 51 against the cam 53 so that it does not lift off the cam 53 or make jumps.
In den Pumpenarbeitsraum 58 mündet eine Steuerbohrung 65 und eine Ablaufbohrung 66, die entlang einer quer zur Längsachse 67 orientierten Steuerachse 75 zueinander fluchtend aus dem Pumpenzylinder 56 ausgenommen sind. Der Pumpenzylinder 56 und der innenliegende Pumpenkolben 55 sind in einem Gehäuse 70 der Brennstoffeinspritzpumpe 2 untergebracht. Von dem in Figur 1 dargestellten Niederdruckpumpenteil 17 strömt geförderter Brennstoff über den Niederdruckanschluß 35 zum in Figur 2 dargestellten Pumpenkolben 55 in einen zwischen dem Gehäuse 70 und dem Pumpenzylinder 56 gelegenen Ringraum 69 und von diesem zur Steuerbohrung 65. Die Abiaufbohrung 66 ist beispielsweise ebenfalls mit dem Ringraum 69 und mit der Steuerbohrung 65 verbunden, um den bei der Förderung desA control bore 65 and a drain bore 66 open into the pump working chamber 58, which are excluded from the pump cylinder 56 in alignment with one another along a control axis 75 oriented transversely to the longitudinal axis 67. The pump cylinder 56 and the internal pump piston 55 are accommodated in a housing 70 of the fuel injection pump 2. From the low-pressure pump part 17 shown in FIG. 1, fuel delivered flows via the low-pressure connection 35 to the pump piston 55 shown in FIG. 2 into an annular space 69 located between the housing 70 and the pump cylinder 56 and from there to the control bore 65. The drain bore 66 is, for example, also with the Annulus 69 and connected to the control bore 65 in order to promote the
Pumpenkolbens 55 abgesteuerten Brennstoff zum Beispiel über einen mit der Ablaufbohrung 66 verbundenen, nicht näher dargestellten Ablaufanschluß am Gehäuse 70 in die Brennstoffrücklaufleitung 37 abzugeben, in welcher der Brennstoff zum Brennstoffbehälter 32 zurückströmt. Der Pumpenkolben 55 hat zum Absteuern des Brennstoffs eine Bohrung 71, die zentrisch im Pumpenkolben 55 ausgenommen ist und eine aus einer Mantelfläche 72 des Pumpenkolbens 55 ausgenommene Steuerkante 73. Die Steuerkante 73 ist in der Figur 2 teilweise sichtbar dargestellt und beispielsweise als sogenannte oben liegende Steuerkante 73 ausgebildet. Die Bohrung 71 erstreckt sich von der Endstirnfläche 57 in Richtung des Stößels 51, beispielsweise parallel zur Längsachse 67 bis zur Steuerkante 73, die schräg zur Längsachse 67 verläuft.Pump piston 55 discharged fuel, for example, via a drain connection on the housing 70 connected to the drain hole 66 and not shown in the fuel return line 37, in which the fuel flows back to the fuel tank 32. The pump piston 55 has a bore 71 for the control of the fuel, which is recessed centrally in the pump piston 55 and a control edge 73 which is recessed from a lateral surface 72 of the pump piston 55. The control edge 73 is shown partially visible in FIG. 2 and, for example, as a so-called overhead control edge 73 trained. The Bore 71 extends from the end face 57 in the direction of the plunger 51, for example parallel to the longitudinal axis 67 to the control edge 73, which extends obliquely to the longitudinal axis 67.
Der Aufbau und die Arbeitsweise einer mit einem Pumpenkolben 55 mit Steuerkante 73 und Steuerbohrung 65 arbeitenden Brennstoffeinspritzpumpe 2 ist dem Fachmann aus der Dieseltechnologie bekannt und wird daher im folgenden nur kurz beschrieben. Der über die Steuerbohrung 65 in den Pumpenarbeitsraum 58 einströmende Brennstoff wird vom Pumpenkolben 55 bei seiner nach oben gerichteten Bewegung verdichtet, wobei ein den Pumpenarbeitsraum 58 begrenzendes Druckventil 85 zunächst geschlossen bleibt. Dabei beaufschlagt eine Druckfeder 87 des Druckventils 85 einen beispielsweise in Form einer Kugel ausgebildeten Ventilschließkδrper 86, so daß eine Verbindung 76 vom Pumpenarbeitsraum 58 zu einer in einem Fδrderteil 77 der Brennstoffeinspritzpumpe 2 vorgesehenen Förderbohrung 63 geschlossen wird. Nach dem Förderbeginn des Pumpenkolbens 55 öffnet der Ventilschließkδrper 86 bei einem von der Druckfeder 87 vorgebbaren Druck, damit Brennstoff vom Pumpenarbeitsraum 58 zur Verbindung 76 und am Druckventil 85 vorbei in die Fδrderbohrung 63 gelangt. Anschließend strömt der Brennstoff von der Förderbohrung 63 in die an die Fδrderbohrung 63 angeschlossene Fδrderleitung 60 zum Brennstoffeinspritzventil 3.The construction and the mode of operation of a fuel injection pump 2 working with a pump piston 55 with control edge 73 and control bore 65 is known to the person skilled in the art from diesel technology and is therefore only briefly described below. The fuel flowing into the pump work chamber 58 via the control bore 65 is compressed by the pump piston 55 during its upward movement, a pressure valve 85 delimiting the pump work chamber 58 initially remaining closed. A compression spring 87 of the pressure valve 85 acts on a valve closing body 86, for example in the form of a ball, so that a connection 76 from the pump work chamber 58 to a delivery bore 63 provided in a delivery part 77 of the fuel injection pump 2 is closed. After the pump piston 55 has started to deliver, the valve closing body 86 opens at a pressure which can be predetermined by the compression spring 87, so that fuel passes from the pump work chamber 58 to the connection 76 and past the pressure valve 85 into the delivery bore 63. The fuel then flows from the delivery bore 63 into the delivery line 60 connected to the delivery bore 63 to the fuel injection valve 3.
Die Fördermenge der Brennstoffeinspritzpumpe 2 läßt sich durch die Drehstellung der Steuerkante 73 des Pumpenkolbens 55 zur Abiaufbohrung 66 einstellen, wobei die Steuerkante 73 bekanntermaßen den Zeitpunkt des Förderendes des in den Pumpenarbeitsraum 58 über die Steuerbohrung 65 eingeströmten Brennstoffs absteuert, so daß der Fδrderhub des Pumpenkolbens 55 und damit die Fördermenge durch Verdrehen des Pumpenkolbens 55, beziehungsweise der Steuerkante 73, einstellbar ist. Im Ausführungsbeispiel fördert die Brennstoffeinspritzpumpe 2 Brennstoff mit einem Druck von etwa 35 bar in die Förderleitung 60 zum Brennstoffeinspritzventil 3.The delivery rate of the fuel injection pump 2 can be adjusted by the rotational position of the control edge 73 of the pump piston 55 to the drain hole 66, the control edge 73, as is known, controlling the point in time at which the fuel that has flowed into the pump working chamber 58 via the control bore 65 ends, so that the delivery stroke of the pump piston 55 and thus the delivery rate can be adjusted by rotating the pump piston 55 or the control edge 73. In the exemplary embodiment, the Fuel injection pump 2 Fuel with a pressure of approximately 35 bar into the delivery line 60 to the fuel injection valve 3.
Zum Drehen des Pumpenkolbens 55 dient ein drehbaresA rotatable one serves to rotate the pump piston 55
Regelelement 80, das beispielsweise in Form einer den Pumpenkolben 55 teilweise umfassenden Regelhülse ausgebildet ist. Das Regelelement 80 wird von der Kolbenfeder 54 und dem Federteller 52 an den Pumpenzylinder 56 angedrückt. Die Verbindung des Regelelements 80 mit dem Pumpenkolben 55 ist dabei derart gestaltet, daß eine axiale Verschiebbarkeit des Pumpenkolbens 55 stets möglich ist, wohingegen bei einer Drehung des Regelelements 80 auch eine Drehung des Pumpenkolbens 55 erfolgt. Hierzu sind beispielsweise zwei Längsschlitze aus einer Innenwandung des Regelelements 80 ausgearbeitet, in denen ein Kolbenmitnehmer 74, eine sogenannte Kolbenfahne, axial gleitend geführt ist, die bei einer Drehung an den Längsschlitzen des Regelelements 80 angreift, um eine entsprechende Drehung des Pumpenkolbens 55 zu bewirken.Control element 80, which is designed, for example, in the form of a control sleeve partially encompassing the pump piston 55. The control element 80 is pressed against the pump cylinder 56 by the piston spring 54 and the spring plate 52. The connection of the control element 80 to the pump piston 55 is designed such that an axial displacement of the pump piston 55 is always possible, whereas when the control element 80 is rotated, the pump piston 55 also rotates. For this purpose, for example, two longitudinal slots are worked out from an inner wall of the control element 80, in which a piston driver 74, a so-called piston vane, is guided in an axially sliding manner, which acts upon the longitudinal slots of the control element 80 when rotating, in order to effect a corresponding rotation of the pump piston 55.
Wie in der Figur 3, einer Schnittdarstellung entlang einer Linie III-III in Figur 2, dargestellt ist, besitzt das Regelelement 80 an seiner Außenfläche 81 eine Eingriffsnut 83, die sich in die Zeichenebene der Figur 3 hinein erstreckt und beispielsweise wenigstens teilweise in Richtung der Längsachse 67 verläuft. In die Eingriffsnut 83 greift ein Eingriffskδrper 84 ein, der mit einer Regelstange 82 verbunden ist. Die Regelstange 82 erstreckt sich im Innern des Gehäuses 70 der Brennstoffeinspritzpumpe 2, versetzt zum Regelelement 80, entlang einer quer zur Längsachse 67 verlaufenden Querachse 68. Der Eingriffskδrper 84 ist beispielsweise in Form eines Kugelkopfes oder eines Stiftes ausgebildet und steht von einer Außenfläche 88 der Regelstange 82 ab. Der Eingriffskδrper 84 greift in die Eingriffsnut 83 des Regelelements 80 ein, um bei einer Verschiebung der Regelstange 82 eine Drehung des Regelelements 80 und des Pumpenkolbens 55 zu bewirken.As shown in FIG. 3, a sectional view along a line III-III in FIG. 2, the control element 80 has an engagement groove 83 on its outer surface 81 that extends into the plane of the drawing in FIG. 3 and, for example, at least partially in the direction of FIG Longitudinal axis 67 runs. An engagement body 84, which is connected to a control rod 82, engages in the engagement groove 83. The control rod 82 extends inside the housing 70 of the fuel injection pump 2, offset from the control element 80, along a transverse axis 68 running transversely to the longitudinal axis 67. The engagement body 84 is designed, for example, in the form of a spherical head or a pin and is located on an outer surface 88 of the control rod 82 onwards. The engagement body 84 engages in the engagement groove 83 of the control element 80 in order to Displacement of the control rod 82 to cause rotation of the control element 80 and the pump piston 55.
Die Regelstange 82 ist im Innern des Gehäuses 70 der Brennstoffeinspritzpumpe 2 mittels zwei Lagern 91, 92, beispielweise Gleitlagern, gelagert. Wie in der Figur 3 dargestellt ist, ist die Regelstange 82 mit ihrem linken Ende 93 an einer Membran 94 einer Versteileinrichtung 90 befestigt. Die Membran 94 trennt zwei Druckräume druckdicht voneinander. Im folgenden wird der in Figur 3 links derThe control rod 82 is mounted inside the housing 70 of the fuel injection pump 2 by means of two bearings 91, 92, for example plain bearings. As shown in FIG. 3, the control rod 82 is fastened with its left end 93 to a membrane 94 of an adjusting device 90. The membrane 94 separates two pressure spaces from one another in a pressure-tight manner. In the following, the one on the left in FIG
Membran 94 dargestellte Druckraum als Anschlußdruckraum 96 und der in der Figur 3 rechts der Membran 94 dargestellte Druckraum als Stelldruckraum 97 bezeichnet. Der Anschlußdruckraum 96 ist über einen Impulsdruckanschluß 99 mit einer Impulsdruckleitung 100 verbunden. DerDiaphragm 94 shown pressure chamber as the connection pressure chamber 96 and the pressure chamber shown in Figure 3 on the right of the membrane 94 referred to as the control pressure chamber 97. The connection pressure chamber 96 is connected to a pulse pressure line 100 via a pulse pressure connection 99. The
Stelldruckraum 97 ist beispielsweise über eine im Stelldruckraum 97 vorgesehene Öffnung 101 und über einen an der Öffnung 101 vorgesehenen Filter 102 im Gehäuse 70 mit einem in der Figur 3 nicht dargestellten Anschluß beispielsweise mit der Atmosphäre verbunden. Wie imControl pressure chamber 97 is connected, for example, to the atmosphere via an opening 101 provided in the control pressure chamber 97 and via a filter 102 provided in the opening 101 in the housing 70 with a connection not shown in FIG. Like in
Ausführungsbeispiel in Figur 1 dargestellt ist, kann die Öffnung 101 aber auch über einen nicht näher dargestellten Anschluß mit einer Startdruckleitung 104 verbunden werden, die zu einer Starteinrichtung 105 führt, deren Aufgabe und Funktion an späterer Stelle des Ausführungsbeispiels näher erläutert wird.Embodiment shown in Figure 1, the opening 101 can also be connected via a connection, not shown, with a start pressure line 104, which leads to a starting device 105, the task and function of which will be explained in more detail later in the embodiment.
Zur Anbindung der Regelstange 82 an die Membran 94 ist beidseitig der Membran 94 ein Anschlußstück 106 angebracht, das mit einem im Stelldruckraum 97 gelegenen Endstück der Regelstange 82 verbunden ist. An einer dem Regelelement 80 zugewandten Seite des Anschlußstücks 106 ist ein Bimetallscheibenpaar 107 vorgesehen, das einen Endbereich der Regelstange 82 umfaßt und von einem Federteller 108 mittels einer Druckfeder 109 an das Anschlußstück 106 angedrückt wird. Das Bimetallscheibenpaar 107 setzt sich aus beispielsweise zwei miteinander verbundenen Metallscheiben zusammen, die einen -unterschiedlichenTo connect the control rod 82 to the membrane 94, a connector 106 is attached on both sides of the membrane 94, which is connected to an end piece of the control rod 82 located in the signal pressure chamber 97. On a side of the connector 106 facing the control element 80, a pair of bimetallic disks 107 is provided, which comprises an end region of the control rod 82 and is pressed onto the connector 106 by a spring plate 108 by means of a compression spring 109. The pair of bimetallic disks 107 is exposed For example, two metal disks connected to each other, which are different
Wärmeausdehnungskoeffizienten aufweisen. Bei einer Erwärmung der Metallscheiben verbiegen sich diese, so daß die Druckfeder 109 zusammengeschoben, beziehungsweise stärker belastet wird. Die Druckfeder 109 stützt sich über den Federteller 108 und das Bimetallscheibenpaar 107 mit dem Anschlußstück 106 an einer Seite der Membran 94 und an der gegenüberliegenden Seite über einen Stützring 110 an einem Absatz 103 ab. Der Absatz 103 ist im Bereich des in Figur 3 links dargestellten Lagers 91 im Stelldruckraum 97 ausgebildet. Die Membran 94 wird von der Druckfeder 109 derart beaufschlagt, das diese bei etwa gleich großen Drücken im Anschlußdruckraum 96 und im Stelldruckraum 97 mit dem im Anschlußdruckraum 96 liegenden Anschlußstück 106 an einer in den Anschlußdruckraum 96 hineinragenden Leerlaufeinstellschraube 111 anliegt.Have coefficients of thermal expansion. When the metal disks are heated, they bend, so that the compression spring 109 is pushed together or is subjected to greater loads. The compression spring 109 is supported via the spring plate 108 and the bimetallic disk pair 107 with the connector 106 on one side of the membrane 94 and on the opposite side via a support ring 110 on a shoulder 103. The shoulder 103 is formed in the area of the bearing 91 shown in FIG. 3 in the signal pressure space 97. The diaphragm 94 is acted upon by the compression spring 109 in such a way that it rests at approximately equal pressures in the connection pressure chamber 96 and in the control pressure chamber 97 with the connector 106 located in the connection pressure chamber 96 on an idle adjustment screw 111 protruding into the connection pressure chamber 96.
Bei einer Druckbeaufschlagung des Anschlußdruckraums 96 mit höherem Druck als dem im Stelldruckraum 97 herrschendenWhen the connection pressure chamber 96 is pressurized with a higher pressure than that prevailing in the signal pressure chamber 97
Umgebungsdruck, wird die Membran 94 entgegen der Kraft der Druckfeder 109, in der Figur 3 nach rechts bewegt, so daß das im Anschlußraum 96 liegende Anschlußstück 106 von einem in den Anschlußdruckraum 96 hineinragenden Ende der Leerlaufeinstellschraube 111 abhebt. Bei sich bewegender Membran 94 wird die mit der Membran 94 verbundene Regelstange 82 nach rechts verschoben, wobei der Eingriffskδrper 84 das Regelelement 80 entgegen dem Uhrzeigersinn dreht und den in Figur 2 dargestellten Pumpenkolben 55 dreht, um dadurch die Fördermenge derAmbient pressure, the diaphragm 94 is moved to the right in FIG. 3 against the force of the compression spring 109, so that the connection piece 106 located in the connection space 96 lifts off an end of the idle adjustment screw 111 which projects into the connection pressure space 96. When the membrane 94 is moving, the control rod 82 connected to the membrane 94 is shifted to the right, the engagement body 84 rotating the control element 80 counterclockwise and rotating the pump piston 55 shown in FIG. 2, thereby reducing the delivery rate of the
Brennstoffeinspritzpumpe 2 zu erhöhen. Bei nachlassender Druckdifferenz verschiebt die Druckfeder 109 die Membran 94, so daß die Regelstange 82 wieder in ihre Ausgangsstellung gelangt, beziehungsweise das Anschlußstück 106 an der Leerlaufeinstellschraube 111 anliegt. Durch Hinein- oderIncrease fuel injection pump 2. When the pressure difference decreases, the compression spring 109 displaces the diaphragm 94 so that the control rod 82 returns to its starting position, or the connecting piece 106 bears against the idle adjustment screw 111. By in or
Herausschrauben der Leerlaufeinstellschraube 111 kann daher eine Einstellung der Mindestfδrdermenge der Brennstoffeinspritzpumpe 2, beziehungsweise eine Einstellung der Leerlaufdrehzahl der Zweitakt-Brennkraftmaschine erfolgen.Unscrewing the idle adjustment screw 111 can therefore the minimum injection quantity of the fuel injection pump 2 is adjusted, or the idle speed of the two-stroke internal combustion engine is adjusted.
Das zweite Lager 92 ist an einem in der Figur 3 rechts dargestellten Ende 95 der Regelstange 82 im Gehäuse 70 der Brennstoffeinspritzpumpe 2 untergebracht und wird von einer schraubbaren Lagerhülse 112 gehalten. Hierzu hat die Lagerhülse 112 an ihrer Außenfläche ein Außengewinde, um gehäusefest in ein Innengewinde des Gehäuses 70 eingeschraubt zu werden, das sich von einer Stirnfläche 114 des Gehäuses 70 in Richtung des Regelelements 80 über das Lager 92 hinaus erstreckt. Im eingeschraubten Zustand der Lagerhülse 112 liegt dabei ein Abschlußstück 116 derThe second bearing 92 is accommodated at an end 95 of the control rod 82 shown on the right in FIG. 3 in the housing 70 of the fuel injection pump 2 and is held by a screwable bearing sleeve 112. For this purpose, the bearing sleeve 112 has an external thread on its outer surface in order to be screwed into the housing 70 in an internal thread which extends from an end face 114 of the housing 70 in the direction of the control element 80 beyond the bearing 92. In the screwed-in state of the bearing sleeve 112 there is an end piece 116
Lagerhülse 112 an der Stirnfläche 114 am Gehäuse 70 an, wobei zwischen dem in Figur 3 rechts dargestellten Ende 95 der Regelstange 82 und einer der Regelstange 82 zugewandten Innenwand 117 der Lagerhülse 112 ein axialer Freiraum 118 ausgespart bleibt. Der axiale Freiraum 118 ist erforderlich, um eine Bewegung der Regelstange 82 entlang der Querachse 68 zu ermöglichen. In den Freiraum 118 ragt eine in ein Gewinde des Abschlußstücks 116 der Lagerhülse 112 eingeschraubte Einstellschraube 119, die von einer Kontermutter 120 am Abschlußstück 116 der Lagerhülεe 112 verdrehsicher gehalten wird. Die Einstellεchraube 119 ist vorgesehen, um eine maximale Verschiebung der Regelstange 82 in Richtung der Querachse 68 zu begrenzen, die bei einer maximalen Druckbeaufschlagung im Anschlußdruckraum 96 auftritt. Bei der maximalen Druckbeaufschlagung im Anschlußdruckraum 96 wird die Regelstange 82 in Figur 3 und 4 nach rechts verschoben, bis die Regelstange 82 mit einer Stirnfläche 98 mit ihrem rechten Ende 95 an der Einstellεchraube 119 anstößt, so daß durch Hinein- oder Herausschrauben der Einstellschraube 119 der maximal verschiebbare Weg derBearing sleeve 112 on the end face 114 on the housing 70, an axial clearance 118 being left free between the end 95 of the control rod 82 shown on the right in FIG. 3 and an inner wall 117 of the bearing sleeve 112 facing the control rod 82. The axial clearance 118 is required to enable the control rod 82 to move along the transverse axis 68. An adjusting screw 119, which is screwed into a thread of the end piece 116 of the bearing sleeve 112, projects into the free space 118 and is held against rotation by a lock nut 120 on the end piece 116 of the bearing sleeve 112. The adjusting screw 119 is provided in order to limit a maximum displacement of the control rod 82 in the direction of the transverse axis 68, which occurs when the connection pressure chamber 96 is subjected to a maximum pressure. 3 and 4, the control rod 82 is shifted to the right until the control rod 82 abuts the adjusting screw 119 with its right end 95 with an end face 98, so that the adjusting screw 119 is screwed in or out maximum displaceable path of the
Regelεtange 82, die maximale Verdrehung des Regelelements 80 und damit eine maximale Fördermenge der Brennstoffeinspritzpumpe 2, einstellbar ist.Regelεtange 82, the maximum rotation of the control element 80th and thus a maximum delivery rate of the fuel injection pump 2 is adjustable.
Bei einer Erwärmung des Bimetallεcheibenpaares 107 erfolgt eine Verkürzung der Einspannlänge der Druckfeder 109, wodurch sich eine erhöhte Federkraft der Druckfeder 109 ergibt, so daß ein größerer Druckunterschied zwischen Überdruck im Anschlußdruckraum 96 und Umgebungsdruck im Stelldruckraum 97 notwendig ist, um die Regelstange 82 zu verεchieben. Das Bimetallscheibenpaar 107 bewirkt bei steigender Temperatur im Anschlußdruckraum 96, beispielsweise aufgrund einer Temperaturerhöhung im Innenraum 10 des Kurbelgehäuses 11 (Figur 1) oder bei steigender Temperatur im Stelldruckraum 97, beispielsweise aufgrund steigender Umgebungstemperatur, eine verringerte Verschiebung der Regelstange 82 bei gleichbleibendem Druckunterschied im Anschlußdruckraum 96 und Stelldruckraum 97, so daß entεprechend weniger Brennεtoff von der Brennstoffeinspritzpumpe 2 zum Brennstoffeinspritzventil 3 gefördert wird.When the pair of bimetallic disks 107 is heated, the clamping length of the compression spring 109 is shortened, which results in an increased spring force of the compression spring 109, so that a greater pressure difference between the overpressure in the connection pressure chamber 96 and the ambient pressure in the signal pressure chamber 97 is necessary in order to displace the control rod 82. The pair of bimetallic disks 107 causes a reduced displacement of the control rod 82 with a constant pressure difference in the connection pressure chamber 96 when the temperature in the connection pressure chamber 96 increases, for example due to a temperature increase in the interior 10 of the crankcase 11 (FIG. 1) or when the temperature in the control pressure chamber 97 increases, for example due to an increasing ambient temperature and signal pressure chamber 97, so that correspondingly less fuel is conveyed from the fuel injection pump 2 to the fuel injection valve 3.
Der in Figur 3 und 4 dargestellte Stelldruckraum 97 ist im Ausführungεbeispiel mittels eines nicht näher dargestellten Anschlusses am Gehäuse 70 der Brennstoffeinεpritzpumpe 2 mit der in Figur 1 dargestellten Starteinrichtung 105 verbunden. Die Starteinrichtung 105 ist über eine Anschlußdruckleitung 115 an das Ansaugrohr 9 εtromabwärts einer Drosselklappe 20 angeschlossen. Die Drosselklappe 20 dient bekanntermaßen zur Leistungsregelung der Zweitakt-Brennkraftmaschine 4 und ist um eine Welle verschwenkbar im Ansaugrohr 9 gelagert. Die Drosselklappe 20 kann beispielsweise mittels eines nicht näher dargestellten Gestänges, beispielsweise mit einem Gaspedal oder mit einem Gashebel, betätigt werden. Die Starteinrichtung 105 wird nur in der Kaltstartphase der Zweitakt-Brennkraftmaschine 4 beispielweise manuell zugeschaltet, um den sich beim Betrieb der Zweitakt- Brennkraftmaεchine 4 im Ansaugrohr 9 einstellenden Unterdruck über die Anschlußdruckleitung 115 zur Starteinrichtung 105 und von dieser über die Startdruckleitung 104 dem Stelldruckraum 97 der Versteileinrichtung 90 zuzuführen. Durch den anstelle deεThe control pressure chamber 97 shown in FIGS. 3 and 4 is connected in the exemplary embodiment to the starting device 105 shown in FIG. 1 by means of a connection on the housing 70 of the fuel injection pump 2, which is not shown in detail. The starting device 105 is connected via a connection pressure line 115 to the intake pipe 9 downstream of a throttle valve 20. The throttle valve 20 is known to serve for power control of the two-stroke internal combustion engine 4 and is pivotally mounted about a shaft in the intake pipe 9. The throttle valve 20 can be actuated, for example, by means of a linkage, not shown in more detail, for example using an accelerator pedal or using an accelerator lever. The starting device 105 is only switched on manually, for example, only in the cold start phase of the two-stroke internal combustion engine 4, by which the two-stroke Brennkraftmaεchine 4 in the intake pipe 9 negative pressure via the connection pressure line 115 to the starting device 105 and from there via the starting pressure line 104 to the control pressure chamber 97 of the adjusting device 90. By instead of deε
Umgebungsdrucks im Stelldruckraum 97 herrschenden Unterdruck ergibt sich folglich eine höhere Druckdifferenz zwischen dem Überdruck im Anschlußdruckraum 96 und dem Unterdruck im Stelldruckraum 97, wodurch die Regelεtange 82 stärker auεgelenkt wird, εo daß bei betätigter Starteinrichtung 105 die Fördermenge der Brennεtoffeinεpritzpumpe 2 erhöht wird. Nach der beim Betrieb einsetzenden Erwärmung der Zweitakt- Brennkraftmaschine 4 kann die Starteinrichtung 105 wieder abgeschaltet werden. Beim Abschalten der Starteinrichtung 105 wird die Startdruckleitung 104 zur Umgebung geschaltet, so daß sich wieder Umgebungsdruck im Stelldruckraum 97 einstellt, der die Fördermenge der Brennstoffeinspritzpumpe 2 nach der Kaltstartphaεe verringert.Ambient pressure prevailing in the control pressure chamber 97 consequently results in a higher pressure difference between the overpressure in the connection pressure chamber 96 and the vacuum in the control pressure chamber 97, as a result of which the control rod 82 is deflected to a greater extent, so that the delivery quantity of the fuel injection pump 2 is increased when the starting device 105 is actuated. After the heating of the two-stroke internal combustion engine 4 which begins during operation, the starting device 105 can be switched off again. When the starting device 105 is switched off, the starting pressure line 104 is switched to the environment, so that ambient pressure is again set in the signal pressure chamber 97, which reduces the delivery rate of the fuel injection pump 2 after the cold start phase.
Wie in der Figur 1 dargestellt ist, führt dieAs shown in Figure 1, the
Impulεdruckleitung 100 zu einer Steuerδffnung 125. Die Steueröffnung 125 iεt aus der Zylinderinnenwand 41 des Zylinders 5 ausgenommen. Korrespondierend zur Steuerδffnung 125 iεt aus einer Kolbenumfangswandung 126 deε Kolbens 6 eine Kolbenδffnung 127 ausgenommen, die eine Verbindung zum Innenraum 10 des Kurbelgehäuseε 11 hat. Bei einer bestimmten Stellung des Kolbens 6 im Zylinder 5 münden die Steuerδffnung 125 und die Kolbenδffnung 127 ineinander, εo daß der Innendruck im Innenraum 10 deε Kurbelgehäuεeε 11 über die Impulsdruckleitung 100 dem Anschlußdruckraum 96 der VerStelleinrichtung 90 zugeführt wird. Da der Kolben 6 bei der Aufwärtεbewegung in Richtung εeineε oberen Totpunktes (OT) einen Unterdruck im Innenraum 10 des Kurbelgehäuses 11 erzeugt, der nicht dem Anschlußdruckraum 96 zugeführt werden soll, ist ein Ventil 128 erforderlich, welches den Unterdruckanteil deε pulsierenden Innendruckε im Kurbelgehäuεe 11 abεchneidet. Das Ventil 128 ist beispielsweise in der Impulsdruckleitung 100 angeordnet und nimmt bei Überdruck in der Impulsdruckleitung 100 bei der nach unten gerichteten Bewegung des Kolbens 6 in Richtung seines unteren Totpunktes (UT) eine Offenstellung ein und ist anεonεten geεchlossen. Durch geeignete Wahl der Lage der Steuerδffnung 125 im Zylinder 5 kann ein bestimmter Bereich des Innendruckes im Kurbelgehäuse 11, beispielεweiεe 15° bis 60° vor dem Erreichen des unteren Totpunktes (UT) des Kolbens 6 ausgewählt und über die Steuerδffnung 125 und die Impulsleitung 100 dem Anschlußdruckraum 96 zugeführt werden. Der dem Anschlußdruckraum 96 zugeführte Überdruck des Kurbelgehäuses 11 übersteigt den Umgebungsdruck im Stelldruckraum 97, εo daß die Membran 94 der Versteileinrichtung 90 in Richtung des Druckgefälles bewegt wird. Die bewegte Membran 94 verschiebt die Regelstange 82, in Figur 3 und 4 nach rechts, wobei das Regelelement 80 gedreht wird. Mittels einer parallel zum Ventil 128 geschalteten Drossel 129, die beispielsweise den Druck in der Impulsdruckleitung 100 regelt und einer zweiten, vor dem Ventil 128 geschalteten Drossel 130 kann eine Feindosierung der Fördermenge der Brennstoffeinspritzpumpe 2 durchgeführt werden. Da nur der Druckunterschied zwischen dem Überdruck im Kurbelgehäuse 11 und dem Umgebungεdruck zur Steuerung der Fördermenge der Brennstoffeinspritzpumpe 2 herangezogen wird, kann der Einfluß sich ändernden Umgebungsdrucks, beispielsweise aufgrund einer geodätischen Hδhenänderung, durch eine entsprechende Änderung der Fördermenge der Brennstoffeinspritzpumpe 2 kompensiert werden. Die Auswahl der Lage der Steuerδffnung 125 im Zylinder 5, beziehungsweise der Lage der korrespondierend angeordneten Kolbenδffnung 127 hat derart zu erfolgen, daß ein weite Betriebsbereiche der Zweitakt-Brennkraftmaschine 4 kennzeichnender Innendruck im Kurbelgehäuse 11 gefunden wird, bei dem durch die stets optimal angepaßte Fördermenge der Brennstoffeinspritzpumpe 2 ein einwandfreies Betriebsverhalten der Zweitakt-Brennkraftmaschine 4 mit optimaler Verbrennung und geringen Abgasemissionen möglich ist. Dabei hat sich herausgestellt, daß dies mit einer Steuerδffnung 125 möglich ist, die etwa im Umfangsbereich deε Anεaugrohres 9 aus der Zylinderinnenwand 41 auεgenommen wird. Gegebenenfalls ist es auch vorteilhaft, mehrere Steuerδffnungen an verschiedenen Stellen der Zylinderinnenwand 41 vorzuεehen, die beiεpielεweise entlang einer gemeinεamen Linie angeordnet εind, um von einer gemeinεamen Kolbenδffnung oder auch mehreren Kolbenδffnungen angeεteuert zu werden. Es ist auch denkbar, mehrere Steuerδffnungen in der Zylinderinnenwand 41 vorzusehen, welche teilweise zeitgleich oder auch nacheinander von korreεpondierend vorgesehenen Kolbenδffnungen angesteuert werden können.Impulse pressure line 100 to a control opening 125. The control opening 125 is excluded from the cylinder inner wall 41 of the cylinder 5. Corresponding to the control opening 125, a piston opening 127, which has a connection to the interior 10 of the crankcase 11, is excluded from a piston peripheral wall 126 of the piston 6. At a certain position of the piston 6 in the cylinder 5, the control opening 125 and the piston opening 127 open into one another, so that the internal pressure in the interior 10 of the crankcase 11 is supplied via the pulse pressure line 100 to the connection pressure chamber 96 of the adjusting device 90. Since the piston 6 generates a negative pressure in the interior 10 of the crankcase 11 during the upward movement in the direction of its top dead center (TDC), which should not be supplied to the connection pressure chamber 96, a valve 128 is required which detects the negative pressure component of the pulsating internal pressure in Crankcase 11 cuts off. The valve 128 is arranged, for example, in the pulse pressure line 100 and, in the event of overpressure in the pulse pressure line 100, assumes an open position during the downward movement of the piston 6 in the direction of its bottom dead center (UT) and is otherwise closed. By a suitable choice of the position of the control opening 125 in the cylinder 5, a specific range of the internal pressure in the crankcase 11, for example 15 ° to 60 ° before reaching bottom dead center (UT) of the piston 6, can be selected and via the control opening 125 and the impulse line 100 Connection pressure chamber 96 are supplied. The overpressure of the crankcase 11 supplied to the connection pressure chamber 96 exceeds the ambient pressure in the control pressure chamber 97, so that the membrane 94 of the adjusting device 90 is moved in the direction of the pressure drop. The moved diaphragm 94 moves the control rod 82 to the right in FIGS. 3 and 4, the control element 80 being rotated. By means of a throttle 129 connected in parallel to the valve 128, which regulates, for example, the pressure in the pulse pressure line 100 and a second throttle 130 connected in front of the valve 128, the delivery quantity of the fuel injection pump 2 can be finely metered. Since only the pressure difference between the overpressure in the crankcase 11 and the ambient pressure is used to control the delivery rate of the fuel injection pump 2, the influence of changing ambient pressure, for example due to a geodetic change in height, can be compensated for by a corresponding change in the delivery rate of the fuel injection pump 2. The selection of the position of the control opening 125 in the cylinder 5, or the position of the correspondingly arranged piston opening 127, has to be carried out in such a way that a wide operating range of the two-stroke internal combustion engine 4 characterizing internal pressure is found in the crankcase 11, in which the delivery quantity which is always optimally adapted means that Fuel injection pump 2 a perfect one Operating behavior of the two-stroke internal combustion engine 4 with optimal combustion and low exhaust emissions is possible. It has been found that this is possible with a control opening 125, which is taken out of the cylinder inner wall 41 approximately in the peripheral region of the suction pipe 9. It may also be advantageous to provide a plurality of control openings at different locations on the cylinder inner wall 41, which are arranged, for example, along a common line in order to be actuated by a common piston opening or also a plurality of piston openings. It is also conceivable to provide a plurality of control openings in the cylinder inner wall 41, which can be actuated in part at the same time or in succession by correspondingly provided piston openings.
Die Figur 4 zeigt ein zweites erfindungsgemäßes Ausführungsbeiεpiel der Brennstoffeinspritzvorrichtung 1 mit Brennstoffeinspritzpumpe 2, wobei alle gleichen oder gleichwirkenden Teile mit den gleichen Bezugszeichen der Figuren 1 bis 3 gekennzeichnet εind. Abweichend gegenüber dem ersten Ausführungsbeispiel nach Figur 3, ist die Druckfeder 109 in Figur 4 im Bereich deε rechten Endes 95 der Regelstange 82 untergebracht. Ohne die Lagerhülse 112 des ersten Ausführungsbeispiels zu verwenden, ist das rechte Lager 92 in einer im Gehäuse 70 vorgesehen Lagerausnehmung 137 untergebracht. Mit dem rechten Ende 95 der Regelεtange 82 iεt ein Federteller 135 verbunden, an dem sich die Druckfeder 109 abstützt. Die Druckfeder 109 ist in einer gestuften Hülse 132 untergebracht, die mit einemFIG. 4 shows a second exemplary embodiment according to the invention of fuel injection device 1 with fuel injection pump 2, all the same or equivalent parts being identified by the same reference numerals from FIGS. 1 to 3. In contrast to the first exemplary embodiment according to FIG. 3, the compression spring 109 in FIG. 4 is accommodated in the area of the right end 95 of the control rod 82. Without using the bearing sleeve 112 of the first exemplary embodiment, the right-hand bearing 92 is accommodated in a bearing recess 137 provided in the housing 70. A spring plate 135, on which the compression spring 109 is supported, is connected to the right end 95 of the control rod 82. The compression spring 109 is housed in a stepped sleeve 132, which with a
Außengewinde in ein sich von der Stirnfläche 114 des Gehäuses 70 der Brennstoffeinεpritzpumpe 2 bis zum rechten Lager 92 erstreckendeε Innengewinde eingeschraubt wird. Die Druckfeder 109 umfaßt teilweise die in der Hülse 132 untergebrachte Einstellschraube 119 und stützt sich mit einem Stützring 131 gegen das Bimetallscheibenpaar 107 ab, das gegenüber dem ersten Ausführungεbeispiel in einem von der Hülse 132 und von einem Einschraubteil 138 der Hülse 132 gebildeten Innenraum 136 untergebracht ist. Das Bimetall¬ scheibenpaar 107 stützt sich gegen das Einschraubteil 138 ab, das zum Beispiel mittelε eines Innengewindes in dieExternal thread is screwed into an internal thread extending from the end face 114 of the housing 70 of the fuel injection pump 2 to the right bearing 92. The compression spring 109 partially includes the adjusting screw 119 accommodated in the sleeve 132 and is supported with a support ring 131 against the pair of bimetallic disks 107, which, compared to the first embodiment, is accommodated in an interior space 136 formed by the sleeve 132 and by a screw-in part 138 of the sleeve 132. The pair of bimetallic disks 107 is supported against the screw-in part 138 which, for example, by means of an internal thread into the
Hülse 132 eingeschraubt wird. Die Einstellschraube 119 ist ebenfalls in ein am Einschraubteil 138 vorgesehenes Innen¬ gewinde eingeschraubt und mittels einer Kontermutter 120 verdrehsicher gehalten. Wie im ersten Ausführungsbeispiel ist zwiεchen dem Federteller 135 und der Einstellschraube 119 ein Freiraum 118 vorhanden, der eine Verschiebung der Regelεtange 82 ermöglicht. Der Freiraum 118 kann durch Hinein- oder Herauεschrauben der Einstellschraube 119 verändert werden, so daß mittels der Einstellschraube 119 die maximale Verschiebung der Regelstange 82 einstellbar ist. Sleeve 132 is screwed. The adjusting screw 119 is also screwed into an internal thread provided on the screw-in part 138 and is held against rotation by means of a lock nut 120. As in the first exemplary embodiment, there is a free space 118 between the spring plate 135 and the adjusting screw 119, which allows the control rod 82 to be displaced. The free space 118 can be changed by screwing the adjusting screw 119 in or out, so that the maximum displacement of the control rod 82 can be adjusted by means of the adjusting screw 119.

Claims

Patentansprüche claims
1. Brennstoffeinspritzvorrichtung für eine Zweitakt- Brennkraftmaschine, mit einer Brennstoffeinspritzpumpe, die einen über ein Antriebselement von einer in einem Kurbelgehäuse der Zweitakt-Brennkraftmaschine untergebrachten Kurbelwelle angetriebenen und in einem Pumpenzylinder längsverschiebbar geführten Pumpenkolben hat, der mit seiner Endstirnfläche einen Pumpenarbeitsraum begrenzt und der an seiner Mantelfläche eine schräg verlaufende Steuerkante aufweist, die den aus dem Pumpenarbeitsraum zu einem Brennstoffeinspritzventil geförderten Brennstoff steuert, das den Brennstoff direkt in einen Brennraum der Zweitakt-Brennkraftmaschine einspritzt, wobei die Fördermenge der Brennstoffeinspritzpumpe durch Verdrehen des Pumpenkolbenε mittels eineε mit dem Pumpenkolben verbundenen Regelelements erfolgt, daε über eine in einem Gehäuse der Brennstoffeinspritzpumpe untergebrachte und mit dem Regelelement verbundene1. Fuel injection device for a two-stroke internal combustion engine, with a fuel injection pump, which has a pump piston driven by a drive element of a crankshaft housed in a crankcase of the two-stroke internal combustion engine and guided in a longitudinally displaceable manner in a pump cylinder, the end face of which delimits a pump work space and that on it Has a sloping control edge, which controls the fuel delivered from the pump work chamber to a fuel injection valve, which injects the fuel directly into a combustion chamber of the two-stroke internal combustion engine, the delivery quantity of the fuel injection pump being effected by rotating the pump piston by means of a control element connected to the pump piston, daε via a housed in a housing of the fuel injection pump and connected to the control element
Regelstange von einer VerStelleinrichtung betätigbar ist, die eine Membran hat, welche zwei Druckräume voneinander trennt und mit welcher die Regelstange verbunden ist, dadurch gekennzeichnet, daß die VerStelleinrichtung (90) mit dem in dem Kurbelgehäuse (11) der Zweitakt- Brennkraftmaschine (2) herrschenden Innendruck beaufschlagt wird.The control rod can be actuated by an adjusting device which has a membrane which separates two pressure chambers from one another and to which the control rod is connected, characterized in that the adjusting device (90) with that in the crankcase (11) of the two-stroke internal combustion engine (2) Internal pressure is applied.
2. Brennstoffeinεpritzvorrichtung nach Anspruch 1, dadurch gekennzeichnet, daß die Versteileinrichtung (90) über eine2. Fuel injection device according to claim 1, characterized in that the adjusting device (90) via a
Impulsdruckleitung (100) an eine aus einer Zylinderinnenwand (41) auεgenommenen Steuerδffnung (125) eines Zylinders (5) der Zweitakt-Brennkraftmaschine (4) anschließbar ist, welche bei Überdeckung mit einer aus einer Kolbenumfangswandung (126) eines Kolbens (6) der Zweitakt-Brennkraftmaschine (4) ausgenommenen Kolbenδffnung (127) , die zum Kurbelgehäuse (11) hin*-offen ist, zeitweise eine Druckverbindung zum Innendruck im Kurbelgehäuse (11) herstellt.Pulse pressure line (100) to one of an inner cylinder wall (41) a control opening (125) of a cylinder (5) of the two-stroke internal combustion engine (4) can be connected, which overlaps with a piston opening (127) which is recessed from a peripheral wall of the piston (126) of a piston (6) of the two-stroke internal combustion engine (4) ), which is open to the crankcase (11), temporarily creates a pressure connection to the internal pressure in the crankcase (11).
3. Brennstoffeinspritzvorrichtung nach Anspruch 2, dadurch gekennzeichnet, daß in der Impulsdruckleitung (100) ein3. Fuel injection device according to claim 2, characterized in that in the pulse pressure line (100)
Ventil (12-8) vorgesehen ist, das bei Überdruck im Kurbelgehäuse (11) zur Versteileinrichtung (90) hin öffnet.Valve (12-8) is provided which opens to the adjusting device (90) when there is excess pressure in the crankcase (11).
4. Brennstoffeinspritzvorrichtung nach Anspruch 3, dadurch gekennzeichnet, daß ein oder mehrere Drosseln (129, 130) in der Impulsdruckleitung (100) angeordnet sind.4. Fuel injection device according to claim 3, characterized in that one or more throttles (129, 130) are arranged in the pulse pressure line (100).
5. Brennstoffeinεpritzvorrichtung nach Anspruch 4, dadurch gekennzeichnet, daß wenigstens eine der Drosseln (129, 130) druckregelbar ausgebildet ist.5. Fuel injection device according to claim 4, characterized in that at least one of the throttles (129, 130) is designed to be pressure-controllable.
6. Brennstoffeinεpritzvorrichtung nach Anspruch 1, dadurch gekennzeichnet, daß in der VerStelleinrichtung (90) eine Druckfeder (109) vorgesehen ist, deren Federkraft von einem Bimetallelement (107) änderbar ist.6. Fuel injection device according to claim 1, characterized in that in the adjusting device (90) a compression spring (109) is provided, the spring force of which can be changed by a bimetallic element (107).
7. Brennstoffeinspritzvorrichtung nach Anspruch 2, dadurch gekennzeichnet, daß ein von der Membran (94) begrenzter Druckraum (97) über eine Druckverbindung (104, 115) an ein Ansaugrohr (9) der Zweitakt-Brennkraftmaschine (4) anschließbar ist.7. Fuel injection device according to claim 2, characterized in that a pressure chamber (97) delimited by the membrane (94) via a pressure connection (104, 115) to an intake pipe (9) of the two-stroke internal combustion engine (4) can be connected.
8. Brennstoffeinspritzvorrichtung nach Anspruch 7, dadurch gekennzeichnet, daß eine Starteinrichtung (105) vorgesehen ist, welche wahlweise eine Druckverbindung des Druckraums (97) mit dem Druck im Ansaugrohr (9) oder mit dem Umgebungsdruck herstellt. 8. Fuel injection device according to claim 7, characterized in that a starting device (105) is provided, which optionally a pressure connection of the pressure chamber (97) with the pressure in the intake pipe (9) or with the ambient pressure.
EP95928417A 1994-09-14 1995-08-11 Fuel-injection system for a two-stroke internal-combustion engine Expired - Lifetime EP0733160B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE4432635A DE4432635A1 (en) 1994-09-14 1994-09-14 Fuel injection device for a two-stroke internal combustion engine
DE4432635 1994-09-14
PCT/DE1995/001063 WO1996008644A1 (en) 1994-09-14 1995-08-11 Fuel-injection system for a two-stroke internal-combustion engine

Publications (2)

Publication Number Publication Date
EP0733160A1 true EP0733160A1 (en) 1996-09-25
EP0733160B1 EP0733160B1 (en) 1999-12-08

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EP95928417A Expired - Lifetime EP0733160B1 (en) 1994-09-14 1995-08-11 Fuel-injection system for a two-stroke internal-combustion engine

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US (1) US5609137A (en)
EP (1) EP0733160B1 (en)
JP (1) JPH09505381A (en)
CN (1) CN1135250A (en)
DE (2) DE4432635A1 (en)
WO (1) WO1996008644A1 (en)

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DE19753702A1 (en) * 1997-12-04 1999-09-16 Dolmar Gmbh Fuel injection device for an internal combustion engine and method for controlling it
US6079379A (en) * 1998-04-23 2000-06-27 Design & Manufacturing Solutions, Inc. Pneumatically controlled compressed air assisted fuel injection system
US6273037B1 (en) 1998-08-21 2001-08-14 Design & Manufacturing Solutions, Inc. Compressed air assisted fuel injection system
US6293235B1 (en) 1998-08-21 2001-09-25 Design & Manufacturing Solutions, Inc. Compressed air assisted fuel injection system with variable effective reflection length
DE19842988A1 (en) * 1998-09-21 2000-03-23 Dolmar Gmbh Starter for Otto engine with direct petrol injection has in normal operation fuel sucked from tank by pump mechanically driven by engine and injected under pressure into cylinder
JP2003206789A (en) * 2002-01-15 2003-07-25 Mitsubishi Electric Corp Fuel injection control device of internal combustion engine
JP5146342B2 (en) * 2009-02-02 2013-02-20 株式会社デンソー Fuel injection valve
CN102679123B (en) * 2012-05-14 2015-03-11 唐作晚 Engine oil compression pump
JP6527689B2 (en) * 2014-12-12 2019-06-05 株式会社不二工機 Diaphragm and pulsation damper using the same

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EP0733160B1 (en) 1999-12-08
US5609137A (en) 1997-03-11
DE59507387D1 (en) 2000-01-13
WO1996008644A1 (en) 1996-03-21
JPH09505381A (en) 1997-05-27
DE4432635A1 (en) 1996-03-21
CN1135250A (en) 1996-11-06

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