EP0630442B1 - Fuel injection device working according to the solid energy accumulator principal, for internal combustion engines - Google Patents

Abstract

The fuel injection system has a unit for producing increase in pressure which includes an impingement device (25), e.g. a rear wall or a piston type stop. The impingement device is provided in a fuel storage element (6) arranged outside an injection pump (1), connected at a pressure line (2) between the injection pump and the injection nozzle (3). The storage element (6) includes a fuel storage chamber (22), in which a spring preloaded diaphragm (23) is arranged. One side of the chamber is arranged at a specified distance to the diaphragm.

Description

The invention relates to a device for injecting fuel for internal combustion engines of the type specified in the preamble of claim 1.

Injection devices, whose electrically operated reciprocating pumps operate according to the so-called solid-state energy storage principle, have a delivery piston or cylinder which is accelerated in a certain way almost without resistance, fuel being generally moved before the delivery pressure which builds up to Spraying the fuel through the injector is required. In this way, kinetic energy is absorbed or stored before the actual pressure build-up required for injection, which is then suddenly converted into a pressure increase in the fuel.

In a so-called pump-nozzle element known from DD-PS 120 514, which works according to the solid-state energy storage principle, the fuel delivery chamber accommodating the delivery piston of the injection pump has, in a first section, axially parallel grooves in the inner wall through which Fuel can flow to the rear of the delivery piston if the delivery piston starts to move without any noticeable pressure build-up in the fuel.

The adjoining second section of the fuel delivery chamber is the actual pressure chamber, which has no grooves. If the accelerated delivery piston enters this pressure chamber, it is suddenly braked by the incompressible fuel, whereby the stored kinetic energy is converted into a pressure surge, through which the resistance of the injection valve is overcome, so that fuel is sprayed off. The disadvantage here is that when the delivery plunger is immersed in the second section of the delivery space, because of unfavorable gap conditions, namely a relatively large gap width and a relatively small gap length, noticeably high pressure losses occur, which in particular reduce the possible speed of the pressure build-up and the pressure height and thus the spraying process adversely affect. The pressure losses are caused by fuel flowing out of the pressure chamber into the pressure antechamber (first section of the fuel delivery chamber).

According to DD-PS 213 472, this disadvantage is to be avoided by mounting an impact body in the pressure chamber of the delivery cylinder on which the piston accelerates almost without resistance, so that the pressure loss during pressure build-up due to a relatively large gap length despite a relatively large gap width (large manufacturing tolerances ) between the impact body and the pressure chamber inner wall area can be kept reasonably small. The disadvantage here, however, is that the impacting process leads to a high level of wear on the bodies that meet. In addition, the impact body is set into longitudinal vibrations by the impact, which are transferred to the fuel and disrupt the injection process there as high-frequency pressure vibrations.

A particular disadvantage of these known solid-state energy storage injection devices is that the injection process can be controlled only to a very limited extent, that is to say it can only be adapted to the load conditions of the engine to a very limited extent.

The object of the invention is to provide an inexpensive, easy-to-manufacture device for injecting fuel using an impact body of the type mentioned above, with which fuel can be injected in a relatively wear-free manner without any noticeable pressure losses during pressure build-up, and fuel can be precisely controlled as a function of load, without vibrations Noticeably impair the spraying process.

This object is achieved by the characterizing features of claim 1. Advantageous further developments of the invention are characterized in the subclaims.

• Fig. 1 bis 5 schematisch im Längsschnitt verschiedene Ausführungsformen der erfindungsgemäßen Einspritzvorrichtung,
• Fig. 6, 7 und 8 schematisch eine der erfindungsgemäßen Einspritzvorrichtung zuarbeitende Kraftstoffzuführeinrichtung für einen Motorstart und einen Motor-Notlauf ohne Batterie,
• Fig. 9 bis 12b schematisch im Längsschnitt Dämpfungseinrichtungen für den Anker der Hubkolbenpumpe,
• Fig. 13, 14 und 15 bevorzugte Ausführungsformen eines Einspritzventils der erfindungsgemäßen Einspritzvorrichtung im Längsschnitt, und
• Fig. 16 eine Kraftstoffversorgungseinrichtung ohne Rückleitung zum Tank,
• Fig. 17 schematisch eine bevorzugte Schaltung zur Ansteuerung der Spule der erfindungsgemäßen Einspritzvorrichtung.

The invention is explained in more detail by way of example with reference to the drawing. Show it:

• 1 to 5 schematically in longitudinal section different embodiments of the injection device according to the invention,
• 6, 7 and 8 schematically a fuel supply device for the injection device according to the invention for an engine start and an engine emergency operation without a battery,
• 9 to 12b schematically in longitudinal section damping devices for the armature of the reciprocating pump,
• 13, 14 and 15 preferred embodiments of an injection valve of the injection device according to the invention in longitudinal section, and
• 16 a fuel supply device without return line to the tank,
• 17 schematically shows a preferred circuit for controlling the coil of the injection device according to the invention.

In the invention, an initial almost resistance-free partial stroke of the impact body of the injection pump is provided, in which if necessary, fuel is displaced.

The injection device according to FIG. 1 has an electromagnetically driven reciprocating piston pump 1, which is connected to a spray nozzle device 3 via a delivery line 2. A suction line 4 branches off from the delivery line 2 and is connected to a fuel reservoir 5 (tank).

The pump 1 is designed as a piston pump and has a housing 8, in which a solenoid 9 is mounted, an armature 10 arranged in the region of the coil passage, which is designed as a cylindrical body and is guided in a housing bore or a cylindrical housing interior 11, which is located in the Area of the central longitudinal axis of the toroidal coil 9, and is pressed by means of a compression spring 12 into an initial position in which it rests on the bottom 11a of the interior 11. The compression spring 12 is supported on the end face of the armature 10 on the injection nozzle side and an annular step 13 of the interior 11 opposite this end face. The spring 12 includes, with play, a delivery piston 14, which is fixed to the armature 10 on the armature end face acted upon by the spring 12, e.g. in one piece, is connected. The delivery piston 14 plunges relatively deep into a cylindrical fuel delivery chamber 15 which is formed coaxially in the axial extension of the housing bore 11 in the pump housing 8 and is in transmission connection with the pressure line 2. Due to the immersion depth, pressure losses during the sudden pressure increase can be avoided, and the manufacturing tolerances between piston 14 and cylinder 15 can even be relatively large, e.g. only need to be in the hundredth of a millimeter range, so that the manufacturing effort is low.

A check valve 16 is arranged in the intake line 4. In the housing 17 of the valve 16, a ball 18 is arranged as a valve element, for example, which in its rest position is supported by a spring 19 against its valve seat 20 on the reservoir side End of the valve housing 17 is pressed. For this purpose, the spring 19 is supported on the one hand on the ball 18 and on the other hand on the wall of the housing 17 opposite the valve seat 20 in the region of the mouth 21 of the intake line 4.

The coil 9 of the pump 1 is connected to a control device 26 which serves as an electronic control for the injection device.

In the de-energized state of the coil 9, the armature 10 of the pump 1 is located on the base 11a due to the pretensioning of the spring 12. The fuel supply valve 16 is closed.

When the coil 9 is actuated via the control device 26, the armature 10 is moved in the direction of the injection valve 3 against the force of the spring 12. The spring force of the spring 12 is made relatively soft, so that the armature 10 is accelerated almost without resistance during the first partial stroke. During the second partial stroke, pressure builds up and fuel is sprayed out, armature 10 and piston 14 moving together.

For the end of the delivery, the coil 9 is switched off. The armature 10 is moved back to the bottom 11a by the spring 12. At the same time, the fuel supply valve 16 opens, so that fuel is sucked out of the tank 5.

A valve 16a is expediently arranged in the pressure line 2 between the injection valve 3 and the branch 4, which maintains a standing pressure in the space on the injection valve side, which pressure e.g. is higher than the vapor pressure of the liquid at the maximum temperature, so that bubbles are prevented. The parking pressure valve can e.g. be designed as the valve 16.

According to the invention, the delivery piston 14 is axially displaceably mounted in the armature 10. For this purpose, there is a graduated armature 10 The central longitudinal bore 108a is designed in the manner of a blind hole, the blind end region of the bore 108a having a smaller diameter than a central partial region and forming a stop ring step 108, the feed piston 14 being guided in the central partial region by a guide ring 105 which is formed integrally therewith and has a larger diameter has as the delivery piston 14 and in this respect is adapted to the expanded central bore area. The guide ring 1Q5 of the delivery piston 14 is acted upon by a compression spring 106 which is relatively softly designed and is supported with its other end at the bottom of the blind hole end region of the bore 108a in the armature 10. In the rest position, the guide ring 105 rests with its ring surface on the delivery piston side through the action of the spring 106 against an annular stop surface 107 of the central partial area, which is designed as a step between the larger-diameter central bore section and the smaller-diameter bore section with the opening that the Feed piston 14 passes through.

1 works as follows. The armature 10 is accelerated almost without resistance during its first partial stroke due to the soft design of the spring 106, the piston 14 remaining at rest. After the path "X" has been covered, the ring step 108 of the bore 108a meets the guide ring 105, as a result of which the stored kinetic energy of the armature 10 is suddenly and suddenly transferred to the piston 14, which releases this energy to the fuel in the pressure chamber 15, 2. wherein an increase in pressure is caused in the fuel, which leads to the spraying of fuel through the nozzle device 3.

The injection device shown in FIG. 2 also has a check valve 16a in the pressure line 2, the construction of which corresponds to the check valve 16 and which is accordingly equipped with a spherical valve element 117 and a return spring 118. The purpose of this check valve is primarily that in the line 2 between the nozzle 3 and Valve 16a maintains a static pressure in the fuel which is, for example, higher than the vapor pressure of the liquid at the maximum temperature that occurs.

Delivery piston 14 and armature 10 are designed to be displaceable relative to one another as in FIG. For this purpose, a through bore 10a through which the delivery piston 14 passes is formed in the armature 10. On the delivery piston 14, an annular stop 14a is attached to the free end which projects out of the armature 10 to the rear. Another stop ring 14b is located in the pressure chamber 15 of the delivery piston 14, the armature 10 being seated between the two stop rings 14a and 14b on the piston 14 with an intermediate space "X" which marks the possible acceleration stroke of the armature 10. The armature return spring 12 engages over the stop ring 14b so that it is not disturbed by the ring 14b.

The function of this embodiment of the injection device corresponds to that of the injection device according to FIG. 1, the armature 10 in this case acting on the piston 14 via the rings 14a and 14b.

In the embodiments of the injection device described above with reference to FIGS. 1 and 2, the delivery of the fuel to the injection nozzle 3 is generated by electromagnetic force and the return movement of the delivery element 14 and the armature 10, which is necessary for fuel intake, is effected by the spring 12. For special applications, however, it can prove to be advantageous to reverse this principle, ie to effect the delivery movement to the injection nozzle by spring force and the suction movement electromagnetically against the spring force, the electromagnetic force simultaneously ensuring that the spring is preloaded again. A corresponding preferred embodiment of the injection device according to the invention is shown in FIG. 3.

With regard to the system arrangement, the injection device shown in FIG. 3 is configured similarly to the injection device in FIG. 2. The injection pump 1 is connected to a pressure line 2 to the injection nozzle 3, a check valve 16a serving to prevent air bubbles being arranged in the pressure line 2, which has the same structure as the check valve 16. The injection pump 1 is actuated electromagnetically. For this purpose, a coil 9 is arranged in the pump housing 8, and in the interior 11 of the housing 8, the armature 10 is axially movable and has axially parallel grooves 10b, via which the areas of the interior 11 in front of and behind the armature 10 are interconnected communicate.

The armature 10 is relative to the delivery piston 14, the delivery piston axially movably passing through a bore 10a in the armature 10. The delivery piston 14 has, at its end facing away from the pressure chamber 15, the stop ring 14a which, as described in more detail below, forms a stop surface in operative connection with a stop bolt 8a which is adjustably mounted in the housing 8 and is adjustable, for example, by means of a Baudenzug. At the other end, the delivery piston 14 projects into the delivery cylinder 15, the stop ring 14b, which has an annular space 14c in the direction of the armature 10, sitting on the part of the delivery piston 14 located in the interior 11. A spring 14d is supported in the annular space 14c, which is supported on the one hand on the armature 10 and on the other hand in the bottom of the annular space 14c.

The armature 10 is acted upon on its rear side by the return spring 12, which is supported on the bottom 11a of the interior 11, so that the armature 10 presses against the ring 14b and presses it against the pressure line-side ring step 13 of the interior 11. The rest position of the delivery piston 14 and the armature 10 is thus defined. The armature 10 is axially freely movable on the delivery piston 14 by the path “X”.

When the coil 9 is excited, the armature 10 is initially only against the spring 12 moves; After the path "X", the delivery piston 14 is included in the armature movement and the suction stroke is carried out. During the suction stroke, the inlet valve 16 opens and fuel flows into the pump chamber 2, 15. The spring 14d ensures that the delivery piston 14 and the armature 10 do not make any undesired relative movements relative to one another. Depending on the amount of electrical energy offered, there is a balance of forces between the spring 12 and the electromagnetic force in the case of different suction stroke paths. The amount of fuel to be sprayed can thus be controlled via the amount of electrical energy supplied.

If the power supply is interrupted after the suction stroke has been completed, the spring 12 accelerates the armature 10 initially without resistance on the path “X” in the direction of the stop ring 14b. When the armature 10 strikes the stop ring 14b, the kinetic energy of the armature 10 is transmitted to the delivery piston 14 and from here as pressure energy to the fuel column in the delivery cylinder 15 and the subsequent pressure line 2. In the process, the inlet valve 16 in the suction line 4 is closed, and the pressure-holding or check valve 16a begins to open.

The delivery piston 14 executes the actual delivery stroke on its way to the possible stop 13, which leads to the fuel being sprayed off via the injection nozzle 3 until the delivery piston rests on the stop 13 with the end face of its annular extension 14b located in the delivery direction, as a result of which the fuel delivery is ended.

This design enables a pressure surge that is kept particularly short over time and is characterized by a defined end of delivery. This results in significant advantages for two-stroke engines that only allow short mixture preparation times due to their particularly high speed. Furthermore, this design enables operation on motors with little modification, which do not provide a defined range of electrical energy, as is necessary for electronic control is. For this purpose, for example, an electromagnetic coil, as is customary, for example, in simple ignition systems for small engines, can be excited once per revolution and deliver a current pulse which, in its weakest form, enables the full armature stroke. In this case, the quantity 8 is adjusted by the stop 8a which adjusts the suction stroke and, for this purpose, is in the simplest case in mechanical connection with the throttle valve of the engine.

The principle of the solid-state energy store for a fuel injection device has the essential advantage that the pressure increase in the pump system is very steep, regardless of the amount of fuel to be sprayed. This allows a small nozzle opening pressure, since when the nozzle is open there is always a high enough fuel pressure at the nozzle for good atomization. This advantage is optimally used in the exemplary embodiment of the injection device according to the invention shown in FIG. 4, in which the delivery piston simultaneously controls the opening and closing of the injection nozzle by striking a nozzle needle. It is also advantageous here that the level of the nozzle opening pressure and thus, for example, the usage-related decrease in the spring force of the nozzle spring has no influence on the amount of fuel sprayed off.

The injection device shown in FIG. 4 provides a constructional design of the injection nozzle 3 and the injection pump 1. The common housing of the device is constructed in several parts and consists of a substantially tubular internal housing cylinder 300, which is divided in a section which surrounds the injection pump armature 10 by a non-magnetic ring element 301, so that the armature 10 by a coil 9 a force can be exerted. The two housing regions of the housing cylinder 300 are hydraulically tightly connected to one another in the region of the ring element 301, and the coil 9 is seated on the outer circumference of the housing cylinder 300, overlapping the ring element 301 in the axial direction.

There is also a cylindrical housing part 302 which surrounds the housing cylinder 300 and surrounds the coil 9 from the outside. At the tank-side end, a connection part 303 is screwed into the housing cylinder 300. The connecting part 303 has a through bore 305, which serves as an inlet line for the fuel, which is symbolized by the arrow in front of the bore 305.

At the other pressure-side axial end of the housing cylinder 300, the injection nozzle 3 is inserted into a thread. Between the nozzle 3 and the connecting part 303, a passage with areas of different sizes is provided in the housing cylinder 300. Subsequent to the connecting part 303, the passage has its largest diameter area, which forms the working space 306 for the armature 10 of the injection pump 1. This working space 306 is delimited on the tank side by an annular bottom surface 11a which serves as a stop surface for the armature 10 when it is urged into its rest position by the spring 12. In the direction of the tank, the bottom surface 11a is followed by an increase in the diameter of the bore 305, in which the inlet valve 16 sits, which has the function of the inlet valve 16 in FIG. 1. The inlet valve 16 has a disk-shaped valve element 307, which is urged against its valve seat by a spring 308, which is formed by the annular surface, which is formed as a step between the passage bore 305 and its enlarged area. The spring 308 is supported at the other end on the armature 10.

The armature 10 is penetrated by a through bore 309 which is axially aligned with the bore 305 of the connecting part 303. The armature 10 has a reduced-diameter area in the pressure-side end area. The armature return spring 12 is supported on the armature 10 on the ring surface which is formed in the step region between the smaller diameter and larger diameter region of the armature 10. On the other hand, the spring 12 is supported on an annular surface which is formed in the housing cylinder 300 on an inwardly projecting ring 300a between the larger-diameter working space 306 and that in the direction of FIG Nozzle 3 following the smaller diameter pressure chamber 11 of the passage of the housing cylinder 300. The reduced-diameter end region of the armature 10 is designed so that it can pass through the ring 300a. In the pressure chamber 11, the delivery piston 14 sits separately from the armature. The delivery piston 14 is designed as a cylindrical hollow body and has a cylindrical cavity 14e which is connected to the pressure chamber 11 by axial bores 312, 313. A pressure valve, which consists of a valve plate 310 and a spring 311 acting on the valve plate 310, sits in the cavity 14e, the valve plate 310 being pressed against the bore 312. The valve plate 310 of the pressure valve thus closes the inlet 312 under spring force, with marginal recesses 310a being made in the valve plate.

The injection nozzle device 3 is inserted into the front side of the housing cylinder 300 and comprises a screwed-in plug-shaped body 314 with a central through bore 314a, which the tappet stem 315 of a valve tappet 317 passes through, the tappet disc 316 closing the outlet of the bore 314a. The plunger plate 316 can thus engage with a valve seat embedded in the plug 314 under the action of a spring 318, which is supported on the one hand on an inner annular end face of the plug 314 and on the other hand on a spring washer 315a, which is on the inner end of the plunger stem 317 is firmly arranged.

The nozzle tappet stem 317 protrudes into the pressure chamber 11 of the housing cylinder 300, in which the delivery piston 14 is urged into its rest position against the ring 300a by the spring 320, which is supported on the plug 314, in which it, with its end face facing the armature, contacts a stop surface 321 of the Rings around 300a. With the injection nozzle 3 closed and the delivery piston 14 in the rest position, an axial distance "H" is left between the inside end of the plunger 317 and the opposite end face of the axially movable delivery piston 14.

The injector shown in Fig. 4 functions as follows. The armature 10 is accelerated against the force of its return spring 12 in the magnetic field generated by the coil 9. During the acceleration stroke "X" (this is the axial distance between the delivery piston 14 and armature 10 when these two elements are in the rest position), the fuel in the pump working space 306 can flow through the bore 309 to the back of the armature. If the armature 10 strikes the delivery piston 14 at the end of its acceleration stroke “X”, the fuel in the pressure chamber 11 is compressed suddenly. Due to this pressure increase and the fact that the delivery piston 14 strikes the plunger stem 315 after a stroke "H", the nozzle 3 is opened and fuel is sprayed off.

During the piston displacement phase, the inlet valve 16 located on the rear of the armature 10 opens and fuel is drawn in from the fuel tank (not shown).

After the spraying process has ended, the delivery piston 14 is again moved by its return spring 320 against its anchor-side stop 321. At the same time, the nozzle needle 317 closes the nozzle bore through its plate 316. When the delivery piston 14 is reset, the pressure valve 310, 311 arranged therein opens and fuel flows from the armature chamber 306 into the pressure chamber 11.

A slightly modified injection device of the injection device shown in FIG. 4 is shown in FIG. 5, essentially only the reference numbers which relate to or are related to the modification are entered. The modification consists in that the tappet stem 315 extends through into the bore 313 and projects into the interior 14e of the delivery piston 14, a ring 322 being formed at the end of the tappet stem 315 which supports the spring 311 of the pressure valve 311 in the space 14e. 310 forms. Marginal grooves 313a are made in the bore 313 for the possibility of flow of fuel.

In this embodiment of the invention, the tappet valve return spring 318 is omitted. At the beginning of the movement of the delivery piston 14, contrary to the inertia of the nozzle needle 317, the pressure in the fuel and the spring force of the spring 311 cause the nozzle 3 to open. Otherwise, the function of the device according to FIG. 5 corresponds to that according to FIG. 4.

With the aid of the injection device according to the invention, an engine start without a battery and an engine emergency run without a battery can be operated. This possibility is described in more detail below with reference to FIGS. 6, 7, 8.

The electrically driven or electronically controlled injection requires sufficient electrical energy to start and run. In the event that the electrical energy is not available in sufficient size, the possibility according to the invention should be created to start engines with the injection according to the invention even without electrical energy, for example by means of a hand crank drive. The required fuel is provided by an auxiliary device, as explained in more detail below. If the engine reaches a speed at which the generator provides sufficient energy, the fuel auxiliary device is switched off according to the invention and the injection is controlled electrically or electronically, corresponding to the normal case.

There are motors that are started without electrical energy, for example by hand or kick start devices. These include small motors from hand tools, two-wheelers or outboards. This starting device is required because there is no battery to start and / or run. In addition, engines should be able to start without electrical energy, for example even when the battery is discharged.

According to the invention, the possibility of starting engines without electrical energy by means of an auxiliary device is achieved in that the fuel supply condition existing on each engine, e.g. the inlet gradient or the pressure of the fuel delivery pump is used at starting speed. The fuel is fed directly to the intake manifold or the overflow in two-stroke engines or a metering device. If the engine then reaches a speed at which the generator provides sufficient energy for the injection, a valve blocks the direct fuel supply to the engine, the fuel is supplied to the injection device and this then takes over the fuel supply to the engine.

6 shows an arrangement according to the invention for supplying fuel to an engine 500. In this case, after a fuel back pressure pump 501, which is connected on the suction side to a fuel storage tank 502, the fuel supply to the engine is branched. In the de-energized state, an injection device 504, which is connected to a generator 503 and is constructed in accordance with one of the above exemplary embodiments, is inactive, and an, for example, electromagnetically actuated control valve 505 is opened for the fuel supply to an atomizer 506 on the engine 500.

When the engine 500 is started, the fuel pressure supplied by the pre-pressure pump 501 is supplied to the atomizer 506 located on the engine 500 via the opened control valve 505. The flow resistance of the control valve 505 and / or the atomizer 506 is dimensioned such that the supply of pressure from the admission pressure pump 501 at the starting speed covers the fuel required for the start. When the generator 503 coupled to the engine reaches a speed at which the energy required for the injection device 504 is covered, an injection control 507 becomes active, which is also fed by the generator 503 and is connected to the injection device 504 via a control line. For this purpose, the control valve 505 is closed by means of a current signal, so that none More fuel can be fed directly to the engine. At the same time, the injection device 504, controlled by the injection control 507, takes over the injection via the injection nozzle 508.

A hand pump 509 present on many engines can optionally also be used during the starting process for the direct fuel supply to the engine via the atomizer 506. The hand pump 509 is arranged in the connecting line 511 from the pump 501 to the control valve 505. The control valve 505 is activated by the injection control 507 via a control line 510.

FIG. 7 shows a modification of the arrangement according to FIG. 6, in which the control valve 505 is arranged in the injection line 511 between the injection device 504 and the injection nozzle 508. The function of stormless starting corresponds to the function explained above with reference to FIG. 6.

In order to ensure the flow of fuel without pump support of the injection device 504, the flow resistance of the injection device 504 is kept small. It is advantageous here that the injection device 504 and the injection line 511 can be vented without problems. If the injection device 504 is to be vented, the control valve 505 is de-energized via an off switch 512 in the line from the injection control 507 to the control valve 505, unless this has already been done by the injection control 507. As a result, the control valve 505 is opened in the direction of the atomizer 506, and the air in the system can escape with simultaneous pumping, for example with the form pressure pump 501 or the hand pump 509.

The engine emergency running without battery provided according to the invention will be described in more detail below with reference to FIG. 8.

The arrangement shown in FIGS. 6 and 7 can also for the Emergency operation of the engine can be used, in which, for example due to failure of the generator, there is insufficient energy available for the injection control and the injection device. According to the invention, a quantity variation of the fuel takes place by a metering device, for example by an adjustable throttle in the control valve coupled to the throttle valve in the air intake pipe, which allows the engine load to be controlled in a makeshift manner.

FIG. 8 shows a suitable embodiment of the control valve or the metering valve 505 in FIGS. 6 and 7. The control valve 505 has a housing 520 into which a coil 521 is inserted, which serves to drive an armature 522, which is shown in FIG a bore 523 of the housing 520 is slidably mounted and in its rest position is pushed by a return spring 524 against an adjustable stop 525 arranged in the housing 520, to which a cable pull 526 is connected outside the housing. Longitudinal grooves 527 are formed in the armature 522, which allow fuel in the bore 523 to communicate between the front and rear of the armature 522. The piston-shaped stop 525 extends through the housing end wall 520b and is biased in the housing 520 by means of a spring 528 with respect to the housing end wall 520b.

A metering piston 527 is formed uniformly with the end face of the armature 522 opposite the stop 525. This end face is also acted upon by the return spring 524, which is supported at the other end against the end wall 520a of the housing 520. The metering piston 527 protrudes with a conically tapering tip end into the delivery line 511, from which a connecting line 511a branches off to the atomizer 506.

The cable pull 526, which is connected to the stop 525 biased under spring force against the armature 522, is connected to the throttle valve 530 (see FIGS. 7, 8). The throttle valve position is thereby transferred directly to the stop 525.

The function of the control valve 505 is as follows. In the de-energized state of the coil 521, the armature 522 and the metering piston 527 rest against the stop 525 by the return spring 524. The fuel can flow from the feed pump 501 through the feed line 511 to the atomizer 506. If the control valve 505 is excited by the control device, the armature 522 pushes the metering piston 527 against the force of the spring 524 in the conveying direction until the inlet cross section 531 of the conveying line 511 is closed.

If the engine is operated in emergency mode without injection, the control valve 505 is de-energized and thus the inlet cross section 531 in the line 511 to the atomizer 506 is released. Corresponding to the throttle valve position, the conical metering piston 527 is pressed more or less far into the bore of the inlet cross section 531 via the armature 522 through the stop 525. The coupling to the throttle valve 530 is chosen so that the cross-section 531 is opened more with increasing opening of the throttle valve 530. In the idle position of throttle valve 530, a minimal gap remains at cross section 531, which allows the amount of idle fuel to pass to atomizer 506.

The armature of the injection pump is usually reset using the return spring provided. To achieve high spray frequencies, the armature reset time must be kept short. This can be achieved for example by a correspondingly large spring force of the return spring. With a reduction in the reset time, however, the impact speed of the anchor at the anchor stop increases. The associated wear and / or the bouncing of the armature at the armature stop can be disadvantageous, as a result of which the total working time is increased. An object of the invention is therefore to keep the fall time of the armature short until it is at rest. According to the invention, this goal is achieved by For example, hydraulic damping of the armature return movement is achieved in the last part of this movement.

FIG. 9 shows an exemplary embodiment of the injection pump, which essentially has the structure of the injection pump 1 according to FIG. 1. For the hydraulic damping, a cylindrical projection 10a is formed centrally on the back of the armature 10 in the manner of a piston-cylinder arrangement, which in the last section of the armature return movement suitably enters a pocket cylinder bore 11b in the base 11a, which on the stop surface 11a for the armature 10 in the housing 8 is trained. Longitudinal grooves 10b are formed in the armature 10, which connect the armature-back space 11 to the armature-front space 11. There is a medium in room 11, e.g. Air or oil that can flow through the grooves 10b when the armature 10 moves. The depth of the blind cylinder bore 11b corresponds approximately to the length of the projection 10a (dimension Y in FIG. 12). Because the projection 10a can dip into the blind cylinder bore 11b, the armature return movement is greatly delayed in the last section, which brings about the desired hydraulic damping of the armature return movement.

10a shows a variant of the hydraulic damping. In this exemplary embodiment, too, the pump chamber 11 through which the delivery piston 14 passes is connected to the chamber 11 adjacent to the back of the armature through bores 10d which open into a central overflow channel 10c in the region of the back of the armature. A central pin 8a of a shock absorber 8b protrudes with its cone tip 8c in the direction of the mouth of the overflow channel 10c, reaches through a hole 8d in the bottom 11a at the rear, which opens into a damping space 8e, and ends in the damping space with a ring 8f which has a larger diameter than the hole 8d. A spring 8g supported on the bottom of the damping space presses against the ring 8f and thus the pin 8a into its rest position (FIG. 10a). A channel 8h connects the insulation space 8e to the rear anchor space 11. The channels 10c and 10d enable the anchor 10 to be almost resistance-free Movement during the acceleration phase.

The damping device 8b is ineffective in the acceleration movement of the armature 10, so that there is no impairment of the lifting phase. During the return movement, the mouth of the overflow channel meets the cone tip 8c and is closed, so that the flow through the channels 10c and 10d is interrupted. The armature 10 presses the pin 8a against the spring force and against the medium in the room 8e, which is also in the room 11 and flows out through the channel 8h into the room 11. The flows are selected so that optimal damping is ensured :

Instead of the channel 8h, according to FIG. 10b, a displacement bore 8i can be arranged centrally in the pin 8a, through which the damping medium can be pressed into the overflow channel 10c.

According to a further advantageous embodiment of the injection device according to the invention, it is provided that the energy stored in the return spring 12 of the armature 10 is used to advantage in the return movement of the armature 10. This can be done according to the invention, for example, by the armature operating a pumping device which can be used for the fuel supply to the injection device to stabilize the system and to prevent bubbles or as a separate oil pump for engine lubrication. 11 shows a corresponding exemplary embodiment of an oil pump 260 connected to the fuel injection pump 1.

The fuel injection device shown in FIG. 11 is otherwise designed in accordance with FIG. 4, that is to say has a fuel inflow and outflow control element for controlling the first partial stroke of the delivery piston 14. The oil pump 260 is connected to the rear floor 11 a of the pump housing 8. In particular, the oil pump 260 comprises a housing 261, which is connected to the housing 8 of the injection pump, and in the pump chamber 261b, a pump piston 262 is arranged, the piston rod 262a of which protrudes into the working space 11 of the armature 10, the piston 262 being acted upon by a return spring 263 which is supported on the housing base 261a in the region of an outlet 264.

In addition, the pump chamber 261b of the housing is connected to an oil reservoir 266 via an oil supply line 265. A check valve 267 is used in the oil supply line 265, the structure of which is similar to the valve 16 in FIG. 1.

The oil pump 260 works as follows. If the armature 10 of the injection pump 1 is moved in the direction of the injection nozzle 3 during its working stroke, the volume of the pump chamber 11 in the housing 8 behind the armature 10 is increased, as a result of which the oil pump piston 262 is moved in the direction of the armature 10 and finally by the action of the return spring 263 is transferred to its rest position. Oil is sucked from the reservoir 266 into the working space 261b of the oil pump 260 via the valve 267. During the return movement of the armature 10 of the pump 1 in the direction of its stop 11a, the oil pump piston 262 is pushed into the oil pump chamber 261b at least over part of the return path of the armature 10. In this case, the valve 267 is closed by the pump pressure and oil is discharged from the oil pump via the outlet 264 in the direction of arrow 264a and pressed to the locations of the engine to be supplied with oil.

The oil pump 260 can alternatively also be used as a fuel back pressure pump, wherein the fuel can be supplied to the valve device 70. It is advantageous here that the pump 260 can generate a static pressure in the fuel supply system which prevents vapor bubbles from forming e.g. counteracts heating of the entire system.

In addition, the inventive design of the additional pump 260 on the pump 1 causes rapid damping of the armature 10, so that the armature 10 does not rebound against the stop 11a.

Figures 12a and 12b show a particularly effective and simple damping device. The structure of the pump device 1 is the same as that shown in FIG. 9. The blind cylinder bore 11b according to FIG. 12a is larger in diameter than the diameter of the cylindrical projection 10a. The projection 10a is surrounded by a sealing lip ring 10e projecting in the direction of the blind cylinder bore 11b and made of an elastic material which fits into the blind cylinder bore 11b. An insertion bevel at the mouth of the blind cylinder bore 11b facilitates the entry of the lips of the sealing lip ring 10e into the blind cylinder bore 11b. This damping device provides good damping when the armature 10 strikes and does not hinder the acceleration stroke of the armature. The elastic damping element 10e with sealing lips protruding axially parallel plunges positively into the pocket cylinder bore 11b during the return stroke of the armature 10 and rests against the inside wall of the pocket cylinder bore 11b in a sealing manner to the outside.

The blind cylinder bore 11b according to FIG. 12b is also larger in diameter than the cylindrical projection 10a. A sealing ring 10f made of elastic material sits positively on the wall of the blind cylinder bore 11b and has inward sealing lips 10g in the region of the mouth. The cylindrical projection 10a is plunged into the elastic sealing element 10f, the sealing lips 10g being pressed against the cylindrical projection 10a due to the outflowing damping medium, so that particularly good damping of the armature 10 is achieved.

13, 14 and 15 show particularly advantageous embodiments of the injection nozzle (e.g. nozzle 3) for the injection device according to the invention.

This injection nozzle comprises a valve seat tube 701, on the free lower end of which the membrane 704 is arranged, optionally a jet-forming pin insert 702 (which sits in a central hole in the membrane 704), a nozzle holder 703, a diaphragm plate 704 prestressed in the direction of the valve seat, a snap ring 705, a pressure line 706 which opens on the valve seat side into an annular channel 708 which is open to the diaphragm 704 and is covered by the diaphragm, a pressure screw 707, a seal 709 for the nozzle holder 703 and a receptacle 710 for the nozzle holder 703.

With the membrane flat seat nozzle shown in FIGS. 13, 14 and 15 with nozzle pin 702 (FIG. 14) and without nozzle pin 702 (FIG. 15), good fuel atomization is achieved on the surface of an arched cone jacket. The shape and dimensions of this jacket include dependent on the dimensions and design of the outlet opening in the membrane (FIG. 14) and can optionally be adapted to the requirements of engine operation with the aid of a known pin or throttle pin with the known functional advantages.

The valve works almost without moving masses and is characterized by a specially designed metal membrane that works with a fixed flat valve seat. The membrane - at the same time because of the valve spring preload - can be preloaded against the direction of opening (e.g. by arching) by suitable, defined and permanent deformation. This allows fuel atomization at low pressures in front of the nozzle opening formed through the central hole in membrane 704, e.g. at low speeds and small injections (in low part-load operation) can be improved. Machining the nozzle hole (rounding the edges, etc.) is easily possible from both directions.

In order to enhance the good closing effect on the valve of the injection nozzle opening outwards, the seat ring width of the flat seat (Fig. 14) can be matched to the preload of the membrane plate. The correct choice of the dimensions of the lower groove in the valve seat contributes to this, which results in the force acting on the membrane at a given standing pressure of the fuel in front of the valve seat. On the other hand, the membrane effectively cooled by the fuel stored in the ring recess or the fuel flowing through it.

The nozzle requires no lubrication and is therefore particularly suitable for petrol, alcohol and mixtures thereof. Due to the way it works - there is no volume downstream of the valve seat - comparatively lower hydrocarbon emissions from the engine are to be expected in this nozzle than with inwardly opening nozzles.

The nozzle consists of a few parts, so it is very easy and inexpensive to manufacture, mass-produce, maintain, check and replace parts.

Fuel supply systems for fuel injection systems are flushed with fuel to cool them and to remove vapor bubbles during operation. This means that the fuel delivery pump provides a larger amount of fuel than is required by the engine. This additional quantity is returned to the tank via a line and is used for heat dissipation and for the removal of fuel vapor bubbles. Vapor bubbles occur during engine operation due to the effects of heat and can disrupt or even prevent the function of the injection system. Steam bubbles can also make it difficult or even impossible to restart the engine while it is still warm.

In certain engine applications, e.g. as an outboard motor on boats, a return line to the tank is not permitted by law for safety reasons.

According to a further embodiment of the invention, a fuel supply device with a fuel injection device according to the invention is therefore designed without a return line to the tank, wherein heat and steam bubbles can nevertheless be removed.

The invention solves this problem by using a second one Fuel pump, a gas separation chamber with a floating valve and a cooler. This arrangement can be attached directly to the engine and thus avoids pressurized fuel lines outside the engine compartment or the engine capsule. This is enough to meet the legal safety regulations.

16, this fuel supply device is explained in more detail below by way of example.

A pump 801 sucks the fuel 802 from the tank 803 and feeds it through a fuel line 804 to a gas separation chamber 805. The gas separation chamber 805 has a float 806, which operates a ventilation valve 807, which acts on a gas discharge line 808 arranged in the ceiling area above the liquid level 805a.

A fuel line 809 is branched off from the bottom of the gas separation chamber 805 and is connected to a pump 810 and leads to an injection valve 811 according to the invention, which is connected via a fuel line 812 to the gas separation container 805, which opens into the gas separation container 805 above the liquid level 805a. As a result, a pressure regulator 813 and a cooler 814 are seated in the fuel line 812 starting from the injection valve 811.

The new fuel supply device for a fuel injection device according to the invention works as follows: The pump 801 sucks the fuel 802 out of the tank 803 and feeds it to the gas separation chamber 805 until the vent valve 807 is closed by the float 806. The pump 810 takes the fuel from the bottom of the gas separation chamber 805 and builds up the pressure required for the respective injection system upstream of the pressure regulator 813. In terms of its delivery characteristic, the pump 810 is designed such that it applies the amount of fuel required for cooling and flushing the injection valve 811 and supplies it to the gas separation chamber 805 via the cooler 814. Now vapor bubbles 805b are placed in the gas separation chamber 805 discharged, the fuel level 805a will decrease, the float 806 opens the vent valve 807 until the pump 801 has advanced to the original level 805a. The vent valve 807 is connected to the air intake pipe 808 of the engine, so that the fuel vapors drawn from the air intake pipe cannot get unburned into the environment.

17 shows a preferred circuit for controlling the armature exciter coil of the injection pumps according to the invention, which ensures optimum acceleration of the armature.

It is known to dose the amount of fuel to be sprayed, for example in a time-controlled manner. A purely time-based control has proven to be disadvantageous, however, because the time window that results between the minimum and maximum amount of fuel to be sprayed is too small to differentiate the quantity spectrum required in engine operation in a differentiated and reproducible manner. However, a sufficiently differentiable quantity metering can be achieved via the pure intensity control of the current flow according to the invention.

In the case of the electromagnetic drive of the fuel injection devices according to the invention, the excitation, i.e. the product of the number of turns of the coil and the current of the current that passes through the coil, determining for the electromagnetic-mechanical energy conversion. This means that an exclusive control of the current amplitude allows the switching behavior of the drive magnet to be uniquely defined, regardless of the effects of coil heating and a fluctuating supply voltage. In this way, such a control system takes into account in particular the electrical voltage conditions and the different temperature conditions, which usually fluctuate strongly in motors.

17 shows a two-point control circuit according to the invention for the current amplitude of the pump drive coil 600 that controls it Current. The drive coil 600 is connected to a power transistor 601 which is connected to ground via a measuring resistor 602. A comparator 603 with its output is applied to the control input of transistor 601, for example to the transistor base. The non-inverting input of the comparator is acted upon by a current setpoint, which is obtained, for example, by means of a microcomputer, and the inverting input of the comparator 603 is connected to the side of the measuring resistor which is connected to the transistor 601.

In order to control the energy flow in the drive coil 600 independently of the supply voltage, the current consumed by the coil 600 is measured by the measuring resistor 602. If this current reaches the limit value specified by a microprocessor as the current setpoint, the comparator switches off the current for the coil 600 via the power transistor 601. As soon as the actual current value drops below the current setpoint, the transistor switches the coil current back on via the comparator. The current rise delay caused by the inductance of the coil 600 prevents the maximum permissible current from being exceeded too quickly.

The next switching cycle can then begin, and this clocking of the coil current of the coil 600 takes place as long as the reference voltage supplying the current setpoint is present at the non-inverting input of the comparator 603.

The circuit represents a clocked current source, the clocking only starting after the current setpoint provided by the microprocessor has been reached. The energy and thus the quantity control of the pump device 1 can take place with this circuit in combination of the duration and / or the amount of the reference voltage provided by the microprocessor.

Claims (53)

1. Fuel injection device which operates according to the solid state accumulator principle, whereby a rotor element (10) contained in a pump housing (8) of an electromagnetically driven reciprocating pump (1) is accelerated virtually without resistance, whereby the rotor element (10) stores kinetic energy and impacts on a piston element (14), so that a pressure impulse is generated in the fuel contained in a sealed pressure chamber (15) before the piston element (14) due to the fact that the stored kinetic energy of the rotor element (10) is transferred via the piston element (14) to the fuel contained in the pressure chamber (15) and whereby the pressure impulse is used for the injection of fuel through an injection device (3), characterised by the fact that the rotor element (10) is carried as a positive connection on the piston element (1).
2. Fuel injection device according to Claim 1, characterised by the fact that the rotor element (10) and the piston element (14) are spring braced against each other.
3. Device according to Claim 1 and/or 2, characterised by an electromagnetically driven reciprocating pump (1), which is connected via a delivery line (2) to an injection device (3), whereby from the delivery line (2) a suction line (4) branches off which is connected with a fuel tank (5).
4. Device according to one of Claims 1 to 3, characterised by the fact that the pump (1) has a housing (8) accommodating a toroid coil (9), whereby in the area of the coil passage the rotor element is arranged which is a cylindrical rotor (10) and is carried in a housing cylinder, located in the area of the central longitudinal axis of the toroid coil (9), whereby the rotor 10 is pressed by a pressure spring (12) into an initial position in which it rests against the bottom (11a) of the housing cylinder and whereby the rotor (10) cooperates on the injection nozzle side with the piston element designed as delivery plunger (14) which enters a cylindrical fuel delivery space (15) relatively deeply, this delivery space being arranged coaxial with the housing cylinder and in transfer connection with the pressure line (2).
5. Device according to Claim 3 and/or 4, characterised by the fact that a non-return valve (16) is arranged in the suction line (4).
6. Device according to one or more of Claims 3 to 5, characterised by the fact that the delivery line (2) between the injection valve (3) and the pressure chamber before the suction line (4) there is arranged a non-return valve (16a) which, in the space on the injection valve side, forms an air chamber for the maintenance of a specific static pressure in the fuel.
7. Device according to one or more of Claims 1 to 6, characterised by the fact that the coil (9) of the pump (1) is connected to a control device (26) which serves as an electronic control for the injection device.
8. Device according to one or more of Claims 3 to 7, characterised by the fact that the rotor (10) has a stepped central longitudinal bore (108a) like a blind bore, whereby the final part of the blind bore (108a) is of smaller diameter than a central part and fonns a stop face (108), whereby in the central part the delivery plunger (14) is guided by an integral guide ring (105) which has a larger diameter than the delivery plunger (14) and to that extent is adapted to the widened central bore area.
9. Device according to Claim 8, characterised by the fact that the guide ring (105) of the delivery plunger (14) is under tension from a pressure spring (106) which is relatively weak and is braced at its other end against the bottom of the blind bore final part of the bore (108) in the rotor (10).
10. Device according to Claim 9, characterised by the fact that in the resting position the guide ring (105) rests with its delivery-plunger-side annular surface against an annular stop face (107) of the central bore part under tension from the spring (106), which stop face is formed as a step between the larger-diameter central bore part and the smaller-diameter bore part with an opening through which extends the delivery plunger (14).
11. Device according to one or more of Claims 1 to 7, characterised by the fact that the rotor (10) has a through-bore (10a) traversed by the delivery plunger (14), that an annular stop (14a) is attached to the delivery plunger (14) at its free end protruding rearward from the rotor (10), a further stop ring (14b) sits in the pressure chamber (15) of the delivery plunger (14), whereby the rotor ( 10) is arranged between the two stop rings (14a) and (14b) with an interspace which represents the possible acceleration stroke of the rotor (10).
12. Device according to Claim 11, characterised by the fact that the rotor return spring (12) engages over the stop ring (14b).
13. Device according to one or more of Claims 1 to 7 and 11 and/or 12, characterised by the fact that the rotor (10) is tensioned at its rear by the return spring (12) which is braced against the bottom (11a) of the interior space (11).
14. Device according to Claim 13, characterised by the fact that the stop ring (14b) has towards the rotor (10) an annular space (14c) in which a spring (14d) is accommodated, which spring is braced on one side against the rotor (10) and on the other against the bottom of the annular space (14c).
15. Device according to one or more of Claims 1 to 14, characterised by integration of the injection device (3) and the injection pump (1), whereby in a common housing an inner housing cylinder (300) is provided which is divided by a non-magnetic ring element (301) into a section enclosing the injection pump rotor (10), so that a coil (9) can apply a force to the rotor (10).
16. Device according to Claim 15, characterised by the fact that the two housing areas of the housing cylinder (300) near the ring element (301) are interconnected hydraulically tight and the coil (9) is positioned on the outer circumference of the housing cylinder (300), whereby the coil engages over the ring element (301) in axial direction.
17. Device according to Claim 15 and/or 16, characterised by a cylindrical housing part (302) surrounding the housing cylinder (300) and enclosing the coil (9) from outside.
18. Device according to one or more of Claims 15 to 17, characterised by the fact that on the tank-side end of the housing cylinder a connecting part (303) which has a through-bore (305) serving as fuel supply line, is screwed in.
19. Device according to one or more of Claims 15 to 18, characterised by the fact that the injection nozzle (3) is screwed into a thread at the pressure-side axial end of the housing cylinder (300).
20. Device according to one or more of Claims 15 to 19, characterised by the fact that there is between the nozzle (3) and the connecting part (303) in the housing cylinder (300) a passage with areas of different diameter, whereby adjacent to the connecting part (303) the passage has its largest diameter which forms the working space (306) for the rotor (10) of the injection pump (1).
21. Device according to Claim 20, characterised by the fact that the working space (306) is bounded on the tank side by an annular bottom surface (11a) serving as a stop face for the rotor (10) when the rotor is pushed into its resting position by the spring (12), whereby in the bottom surface (11a) towards the tank there follows a diameter increase of the bore (305) accommodating the supply valve (16).
22. Device according to Claim 20 and/or 21, characterised by the fact that a through-bore (309) passes through the rotor (10), whereby this through-bore aligns axially with the bore (305) of the connecting part (303), that the rotor has a diameter-reduced area in the pressure-side end part, the rotor return spring (12) is braced at the rotor (10) against the annular face formed in the stepped area between the smaller-diameter area and the larger-diameter area of the rotor (10), at the other end the spring (12) is braced against an annular surface formed in the housing cylinder (300), against a ring projecting inwards (300a) between the larger-diameter working space (306) and, following towards the nozzle device (3), the smaller-diameter pressure chamber (11) of the passage of the housing cylinder (300).
23. Device according to Claim 22, characterised by the fact that the diameter reduced end of the rotor (10) is so designed that it can pass through the ring (300a).
24. Device according to Claim 23, characterised by the fact that the delivery plunger (14) sits in the pressure chamber (11) separate from the rotor (10), is formed as a cylindrical hollow body and has a cylindrical cavity (14e) which communicates with the pressure chamber (11) through axial bores (312, 313), whereby in the cavity (14e) there is a pressure valve consisting of a valve head (3 10) and a spring (311) acting on the valve head (310).
25. Device according to one or more of Claims 15 to 24, characterised by the fact that the injection nozzle (3) is inserted in the front face of the housing cylinder (300) and comprises a screwed-in plug-shaped body (314) with a central through-bore (314a) through which passes the push rod (315) of a valve lifter (317) whose tappet head (316) closes the outlet of the bore (314a).
26. Device according to Claim 25, characterised by the fact that the valve lifter (317) is actuated by a spring (318) braced on one side against an inner annular front face of the plug (314) and on the other against a spring washer (315a) arranged at the inner end of the push rod (317).
27. Device according to Claim 26, characterised by the fact that the push rod (315) protrudes into the pressure chamber (11) of the housing cylinder (300) in which the delivery plunger (14) is pushed against the ring (300a) by the spring (320) braced against the plug (314), where it rests against a stop face (321) of the ring (300a) with its front face towards the rotor.
28. Device according to one or more of Claims 15 to 27, characterised by the fact that the push rod (315) passes through the bore (313) and protrudes into the interior space (14e) of the delivery plunger (14), whereby at the end of the push rod (315) there is a ring (322) which in the space (14e) forms a support for the spring (311) of the pressure valve (311,310).
29. Device according to Claim 28, characterised by the fact that peripheral grooves (313a) are formed in the bore (313).
30. Device according to one or more of Claims 1 to 29, characterised by an auxiliary starting device with a control valve which is connected to an atomizer (506) of the engine (500) and receives fuel from the fuel tank (502) and whose flow resistance together with that of the atomizer (506) is so determined that at starting engine speed with the pressure delivered by a precompression pump (501) the fuel requirement for starting can also be covered without electrical energy supply to the injection device (504).
31. Device according to Claim 30, characterised by the fact that after the fuel precompression pump (501) which is connected on the induction side with the fuel tank (502), a branch line of the fuel line to the engine is provided, whereby in the de-energised state an injection device (504) connected to a generator (503) (the injection device being constructed in accordance with the invention and particularly with one of the invention-based embodiments) is inactive and the control valve (505) which may, e.g. be electromagnetic, is open for the supply to the atomizer (506) on the engine (500).
32. Device according to Claim 30 and/or 31, characterised by the fact that a hand pump (509) on the engine is additionally used during starting for the direct fuel supply to the engine via the atomizer (506) which is arranged in the connection fine (511) from the pump (501) to the control valve (505), whereby the control valve (505) is triggered by the injection control (507) via a control line (510).
33. Device according to Claim 30, characterised by the fact that the control valve (505) is arranged in the injection line (511) between the injection device (504) and the injection nozzle (508).
34. Device according to Claim 33, characterised by a cutout in the line from the injection control (507) to the control valve (505).
35. Device according to Claim 33 and/or 34, characterised by the fact that the based auxiliary starting device is used for emergency running of the engine, whereby a metering valve (505) effects a fuel quantity variation.
36. Device according to one or more of Claims 30 to 35, characterised by the fact that the metering valve (505) has a housing (520) into which a coil (521) is inserted which serves as a drive of a rotor (522) which is mounted slidable in a bore (523) of the housing (520) and is pushed in its resting position by a return spring (524) against an adjustable stop (525) arranged in the housing (520), while to this stop outside the housing a cable pull (526) is attached, whereby the rotor (522) has peripheral longitudinal channels (527) enabling communication for the fuel in the bore (523) between the front and rear of the rotor (522) and whereby the stop (525) shaped like a piston passes through the housing front wall (520b) and in the housing (520) is pretensioned in relation to the housing front wall (520b) by a spring (528) and whereby a metering piston (527) is of uniform construction with the front face of the rotor (522) opposite the stop (525) and whereby this front face additionally is under tension from the return spring (524) which is braced at the other end of the front wall (520a) of the housing (520) and whereby the metering piston (527) protrudes with a tapering end into the delivery line (511) from which moreover a connection line (511a) branches off to the atomizer (506) and whereby the cable pull (526), connected to the stop (525) held by spring force against the rotor (522), is connected to the throttle valve (530).
37. Device according to one or more of Claims 1 to 36, characterised by a hydraulic damping device for the rotor element (10) of the reciprocating pump.
38. Device according to Claim 37, characterised by the fact that the hydraulic damping device is constructed like a piston cylinder arrangement, whereby on the rotor (10) there is a central cylindrical projection (10a) which in the last section of the rotor return movement fits into a blind cylinder bore (11b) in the bottom (11a) of the cylinder, whereby the rotor (10) has longitudinal channels (10b) which connect the space at the rear of the rotor with the space at the front of the rotor in the pump cylinder.
39. Device according to Claim 37, characterised by the fact that the pump space (11) traversed by the delivery plunger (14) is connected before the piston (10) with the space (11) adjoining the rear of the rotor by bores (10d) which lead into a central transfer passage (10c) in the area of the rear of the rotor, whereby a central pin (8a) of a shock absorber (8b) protrudes with a taper point (8c) towards the opening of the transfer passage (10c).
40. Device according to Claim 39, characterised by the fact that the central pin (8a) at the rear passes through a hole (8d) in the bottoms (11a) which leads into a damping chamber (8e), whereby the pin (8a) ends in the damping chamber with a ring (8f) which has a larger diameter than the hole (8d) and whereby a spring (8g) braced against the bottom of the damping chamber presses against the ring (8f) and whereby a passage (8h) connects the damping chamber (8e) with the rear rotor space (11).
41. Device according to Claim 39, characterised by the fact that in the pin (8a) a displacement through-bore is centrally arranged, through which the damping medium can be pressed into the transfer passage (10c).
42. Device according to Claim 37, characterised by the fact that the rotor (10) during its return movement operates a pump device which simultaneously ensures damping of the rotor (10).
43. Device according to Claim 42, characterised by the fact that an oil pump (260) is connected to the rear bottom (11a) of the pump housing (8), which pump has a housing (261) in whose pump space (261b) a pump piston (262) is arranged whose piston rod (262a) protrudes into the working space (11) of the rotor (10), whereby the piston (262) is under tension from a return spring (263) braced against the housing bottom (261a) near an outlet (264).
44. Device according to Claim 43, characterised by the fact that the pump space (261b) communicates via an oil supply line (265) with an oil reservoir (266), whereby a non-return valve (267) is inserted in the oil supply line (265).
45. Device according to Claim 37 and/or 38, characterised by the fact that the blind cylinder bore (11b) has a larger diameter than the diameter of the cylindrical projection (10a) and the projection (10a) or the blind cylinder bore (11b) has an annular sealing lip (10e) or (10d), whereby the circular sealing lips form the piston seal for the projection (10a).
46. Device according to one or more of Claims 1 to 45, characterised by an injection nozzle with a valve seat pipe (701) with a ring channel (708) at the end, a diaphragm plate (704) pretensioned towards the valve seat, the diaphragm plate having a central hole and covering the ring channel (708), if necessary with a plug insert (702) in the hole of the diaphragm (704), a spring ring (705) and a pressure line (706).
47. Device according to one or more of Claims 1 to 46, characterised by a fuel supply device without a return line to the tank, whereby a second fuel pump, a gas separation chamber with float valve and a condenser are used.
48. Device according to Claim 47, characterised by a gas separation chamber (805), into which via a line (804) fuel (802) is pumped from a tank (803) by a pump (801), out of which fine a pump (810) feeds fuel via a fuel line (809) to an injection valve (811), whereby a line (812) is led back from the injection valve (811) into the gas separation chamber (805) where a pressure regulator (813) and a condenser (814) are arranged, whereby in the gas separator (805) a float (806) is provided which operates a vent valve (807) which is installed in a discharge line (808) coming out into the gas separation chamber (805).
49. Device according to Claim 48, characterised by the fact that the fuel line (812) comes out into the gas separation chamber (805) above the liquid level (805a).
50. Device according to Claim 48 and/or 49, characterised by the fact that the discharge fine (808) comes out into the gas separation chamber (805) above the liquid level (805a).
51. Device according to one or more of Claim 48 to 50, characterised by the fact that the fuel line (804) comes out into the gas separation chamber (805) above the liquid level (805a).
52. Device according to one or more of Claims 48 to 51, characterised by the fact that with the exception of the tank (803) all components of the fuel injection system are arranged in the engine compartment (815).
53. Device according to one or more of Claims 1 to 52, characterised by a circuit for driving the rotor excitation coil (9, 600) which is connected to a power transistor (601) which via a measuring resistor (602) is grounded, whereby a comparator (603) is connected with its output onto the control input of the transistor (601), e.g. to the transistor base, and whereby a current setpoint is applied to the noninverting input of the comparator (603), this setpoint being obtained from e.g. a microcomputer and whereby the inverting input of the comparator (603) is connected to the side of the measuring resistor connected with the transistor (601).

Images