EP0764254B1 - Oil burner - Google Patents

Abstract

PCT No. PCT/EP95/02317 Sec. 371 Date Nov. 1, 1996 Sec. 102(e) Date Nov. 1, 1996 PCT Filed Jun. 14, 1995 PCT Pub. No. WO95/34786 PCT Pub. Date Dec. 21, 1995A heating system with a combustion chamber into which fuel is fed via a fuel feed unit in the form of an injection device which operates on the energy-storage principle and has a pump and a nozzle device which delivers bursts of fuel in specified quantities. With this fuel burner, it is possible to select both the quantity of fuel injected and the injection frequency independently of any boundary conditions, thereby optimizing levels of harmful pollutants in the exhaust gas and effectively counteracting resonance vibrations in the burner.

Description

The invention relates to an oil burner for thermal systems according to the preamble of claim 1. Such a burner is known from document DE-A-2 354 708.

Oil burners for thermal systems traditionally include a combustion chamber into which a nozzle continuously Fuel is supplied.

Oil burners, especially large burners, experience resonance vibrations on, the vibration behavior in oil burners caused by the combustion chamber and the type of air supply that together form a sound box.

For gas burners that are operated at the resonance frequency, as described for example in WO 92/08928 the causes of such vibrations are known, and the resulting disadvantages are different Fought against means.

Due to the inertia of the gas flowing in a feed pipe, there is a negative pressure in the combustion chamber after combustion, whereby gas and air are sucked in on the one hand and on the other hand, hot combustion gases flow back, which is the following ignite the inflowing fuel mixture. So it turns out a cyclical process that pulsates at a frequency that essentially from the dimensions of the combustion chamber and the feed pipe or the supply line and the type of gas depends.

Such pulsed burners can make an enormous noise cause that is between about 90 and 140 dB (A). That's why a system was provided in WO 92/08928 that the resonance system from combustion chamber and fuel supply line acoustically decoupled from the downstream heat exchanger. The one with these pulsed burner resonance frequency is about at some 100 Hz and depends on the shape and size of the through the combustion chamber and the feed lines formed cavities.

In the case of gas burners, one also tries to find resonance vibrations through damping cavities to prevent the Gas supply line are arranged. Such an arrangement is known for example from DE 33 24 805 A1.

For simple small oil burners that are used to operate Small house heating systems are suitable and in general resonance vibrations can occur if they are not to be operated in pulsed mode not just make an unpleasant noise, but also lead to the destruction of the oil burner.

Furthermore, oil burners are known to have gas burners bad exhaust gas values, on the one hand due to the contained in the oil Components and secondly by poorer atomization of the sometimes viscous oil in the combustion chamber be so that it is difficult to get a full stoichiometric To achieve combustion. The oil supply lines also drip for continuous oil supply after, resulting in poor Combustion leads in terms of exhaust gas values.

A large number of different ones have been used for internal combustion engines for a long time Types of fuel injectors are known. These fuel injectors are usually designed as a pump-nozzle system. As pumps become electromagnetic operated pumps where the reciprocating piston is used the pump is driven by an electromagnet Anchor is applied. There are also various pumps with piezoelectric Actuators known.

In DE-OS 23 07 435 is a fuel injection device described for internal combustion engines in which the pump work space by an electrically driven reciprocating pump with the Pressure chamber of at least one hydraulically operated spring-loaded Injector connected and via an inlet valve a pressure source is connected. The pump piston closes Start of the pumping process in a certain idle stroke, whereby the Mass of the pump piston accelerates before the actual pump stroke and the stored kinetic energy to increase the pressure is used in the pump work room. For this sees the Injector as a pump piston before a soft iron anchor, by a linear motor over a relatively long distance is driven.

Such injection devices working with the energy storage principle have been further developed as a result. Appropriate Injectors are from DD-PS 120 514 and DD-PS 213 472 known. This according to the solid-state energy storage principle working fuel injectors accelerate the armature of the electromagnet and thus the fuel-liquid column over a longer distance before the Pressure is built up to spray the fuel over the nozzle is required. These fuel injectors have the advantage that they have low drive energy get along and due to small moving masses a high working frequency to reach. They also achieve high pressures.

According to DD-PS 120 514, the piston is penetrated by the delivery piston Fuel conveyor in a first section with axially arranged Provide grooves through which the fuel can drain can, without there being a substantial pressure build-up, the in the subsequent second section of the conveyor, that has no fluid drainage grooves. The delivery piston is therefore slowed down by the incompressible fuel, whereby a pressure is built up in the fuel, through which the Resistance of the injector is overcome, so that it Fuel injection is coming. The disadvantage here is that when the delivery piston is immersed in the closed section of the feed cylinder due to unfavorable gap conditions, namely a large gap width and a small gap length, Large pressure drops occur which create the necessary pressure adversely affect for hosing down. According to DD-PS 213 It has therefore been proposed in 472 on the feed cylinder to arrange a striking body so that the pressure loss despite relatively large gap widths is kept reasonably small. The disadvantage here, however, is that it is due to the impact process wear of the colliding bodies. Farther the impact body becomes longitudinal vibrations excited that are transferred to the fuel and there the injection process as high-frequency pressure vibrations adversely affect.

Another fuel injection device is known from WO 93/18297 out, according to the solid-state energy storage principle works, one in a pump cylinder with one Reciprocating piston driven solenoid driven piston element Parts of the fuel to be sprayed off during an almost resistance-free acceleration phase during which the piston element stores kinetic energy before hosing down displaced in the pump area and the displacement suddenly to stop the repression, so that a pressure surge is located in a closed pressure chamber Fuel is generated by the stored kinetic Energy of the piston element directly to that in the pressure chamber located fuel is transmitted. The pressure surge becomes Spraying of fuel through an injector device used, the one that interrupts the displacement, the pressure surge generating agent outside the leading, liquid-tight Contact area between the piston element and the piston cylinder the reciprocating pump are arranged, thereby controllability with high frequency and excellent accuracy of delivered amount of fuel is reached. In particular can even small amounts of fuel can be dispensed precisely. Another fuel injection device for internal combustion engines, that works on the energy storage principle is over WO 92/14925 known. The structure of such a conventional one The injection device is described below with reference to FIG. 23 described in more detail. A fuel tank 601 is turned into a fuel pump 602 with a pressure of approximately 3 to 10 bar Fuel is fed into a pipeline 605, in which a Pressure regulator 603 and a damping device 604 arranged are. At the end of the line 605 is an electromagnetic, for example operated shut-off valve 606 provided, via which Fuel accelerated by pump 602 when open is returned to the reservoir 601. By abrupt closing of the shut-off valve 606 becomes the kinetic Energy of the line 605 and line 607 flowing fuel converted into pressure energy. The size the resulting pressure surge is about 20 to 80 bar, that is about ten times the flow pressure generated by the pump 602 on line 605, also called the swing line becomes. The pressure surge thus created at the shut-off valve 606 becomes The fuel accelerated in this way is sprayed over an injector 610 used, which via a pressure line 609 connected to valve 606 and thus to line 605 is.

By using an electromagnetically operated shut-off valve this known injection device is electronic controllable by means of one connected to the valve 606 electronic control unit 608.

With this basic structure of the injector, the it works with an energy stored in the fuel disadvantageous that a pre-pressure supply is required, which the for the acceleration of the fuel liquid column in the necessary energy to the swing line, and which works continuously. This continuously working pre-pressure supply makes a corresponding effort for education constant maintenance is necessary. For this purpose, the Pump 602 too much fuel delivered via the pressure control valve 603, which is connected via a return line to the Reservoir 601 communicates. This pressure cutoff leads to a loss of energy, and thus in addition to an increase the fuel temperature to pressure changes at the injection valve 606, which affects the accuracy of the injection becomes. In addition, the pressure control valve 603 always needs a minimum regulation quantity in order to work stably, whereby another loss of energy occurs. Because the volume flow requirement on the injector 10 depends on the engine speed, and the quantity to be sprayed, the pressure supply unit the flow rate for full-load operation already at idle promote, whereby relatively large amounts of fuel with appropriate Energy loss for the entire system via the pressure control valve 603 must be shut down.

For this reason, WO 92/14925 proposes that for injection required fuel volume flow for each injection process to be provided only as long as this depends from the engine operating conditions according to time and quantity requirements is required. By using an intermittent operated fuel acceleration pump is eliminated continuous supply of pre-pressure, which is the energy balance of the Injector benefits. Utilization is optimized the energy further through the use of a common control device for the acceleration pump and the electrically operated Delay device, for example in the form of a Electromagnetically actuated shut-off valve.

Preferred is an intermittently operating fuel acceleration pump an electromagnetically operated piston pump used. However, it can also be a diaphragm pump for fuel acceleration provided within the pressure surge device will. Instead of an electromagnetic pump drive can also be an electrodynamic, a mechanical or a Drive means piezo element may be provided.

By controlling the pump and delay device together can not only the pump and delay setup time can be optimally adapted to each other. Rather allowed this common control also the injection frequency and the injection quantity free to choose. This is especially true if one Fuel injection device working according to the solid-state energy storage principle is used.

It can thus be summarized that it is on the one hand in the state the technology of continuously operating oil burners gives certain Have disadvantages, especially due to pressure fluctuations of resonances and their exhaust gas values are not always the desired ones Meet requirements and on the other hand for internal combustion engines a variety of different injection devices for a long time are known to be smaller especially for tax purposes Amounts of fuel are designed.

The invention has for its object an oil burner for to create a thermal system with which it is possible Avoid pressure vibrations safely and excellent exhaust gas values to reach.

The task is accomplished by an oil burner with the features of the claim 1 solved.

By providing an oil burner with an injector, which works according to the energy storage principle from a pump and a nozzle or a valve that a defined Quantity of fuel is suddenly injected into the combustion chambers, can occur with conventional oil burners Pressure vibrations in the resonance range thanks to precise control the frequency can be prevented. This is mainly due to the Energy storage principle achieved, the delivery is very short High frequency and high pressure pulses allowed. By the high pressure will also atomize the fuel very well achieved in the combustion chamber and a very precise dosage, whereby the pollutant values are kept low.

Preferably, the one forced by the injection process Frequency chosen so that the frequency distance from the resonance frequency the combustion chamber is as large as possible.

By providing the injection device according to the invention it is possible for the first time with a previously unknown Accuracy to control the amount of oil supplied to the combustion chamber or to regulate, whereby an exact setting of the oil / air ratio is possible, so that a stoichiometric combustion ratio or one with excess air can to keep the pollutants in the exhaust gas low.

With the burner according to the invention there is also a large control range reached in relation to the amount of oil supplied, so that both very small amounts of oil with great precision as well as large ones Amounts of oil can be supplied to the combustion chamber. this applies especially if in addition to the variable frequency defined amount of fuel can be changed per injection process can. The large control range allows that in a very simple way Bypassing the critical burner conditions.

The success of the device according to the invention is based on The fact that the vibrations and pollutants that occur not through compensating devices such as one Vibration decoupling, to be fought, but directly on site the creation by controlling the flame itself be prevented. Thus, for those that occur during combustion Problems don't require multiple approaches that attack at a different location on the oil burner, but can be solved by the injector alone.

The sudden supply of the oil by the injection device according to the invention enables injection pulses from less than 10 ms to in the order of 1 ms, so that they are suitable for the counteract usual resonance vibrations of a few 100 Hz.

The quick response of the injection device according to the invention also reliably prevents overshoot the control of the oil supply, that of conventional oil burners could not be avoided and leads to increased exhaust gas values. Furthermore, the oil burner according to the invention can be fast Response behavior operated in a closed control loop with a gas sensor in the fireplace or in the combustion chamber the resulting gases are measured and determined to be as low in pollutants as possible Regulates values with high thermal efficiency. Such gas sensors can be sensitive to oxygen or carbon monoxide, for example be.

The injector preferably comprises one by one Electromagnet driven pump, in particular in oil burners Large burners, necessary pumping capacity of some kg / h up to 900 kg / h. Such from one Electromagnet driven pumps based on the solid-state energy storage principle work, include one with an electromagnet driven piston pump with one in a pump cylinder guided piston element, the subsets of the sprayed Fuel during an almost resistance-free Acceleration phase during which the piston element is kinetic Stores energy before hosing down in the pump area displaced and the repression suddenly with the repression interrupting means is stopped, so that a pressure surge in fuel located in a closed pressure chamber in which the stored kinetic energy of the piston element directly on the fuel in the pressure chamber is transmitted. The pressure surge becomes a spray of fuel used by an injector device.

Those based on the solid-state energy storage principle are particularly advantageous fuel injectors working when the pressure generating means outside the leading one liquid-tight contact area between the piston element and reciprocating cylinder of the reciprocating pump are arranged so that in a simple way a practically wear-free one Injector is obtained with very short injection pulses larger amounts of fuel in the combustion chamber can inject.

Such simply constructed injection pumps based on the solid-state energy storage principle work and few moving parts have to be preferred for oil burners because they have a long lifespan, what with long-term operation an oil burner is very important.

Advantageous embodiments of the invention emerge from the subclaims and the description.

Fig. 1 bis 19

schematisch im Längsschnitt verschiedene Ausführungsformen von Einspritzvorrichtungen, die beim erfindungsgemäßen Ölbrenner verwendet werden.

Fig. 20

eine Einspritzvorrichtung mit zwei Pumpen und einer Düse,

Fig. 21

eine Einspritzvorrichtung, die aus mehreren Pumpen und Düsen besteht, die in einen einzigen Düsenstock münden,

Fig. 22

den Düsenstock aus der Sicht des Brennkammerinnenraums und

Fig. 23

eine schematische Darstellung einer Einspritzvorrichtung nach dem Energiespeicher-Prinzip, die die in der Flüssigkeit gespeicherte Energie ausnützt.

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

1 to 19

schematically in longitudinal section various embodiments of injection devices that are used in the oil burner according to the invention.

Fig. 20

an injector with two pumps and one nozzle,

Fig. 21

an injection device consisting of several pumps and nozzles which open into a single nozzle assembly,

Fig. 22

the nozzle assembly from the perspective of the combustion chamber interior and

Fig. 23

is a schematic representation of an injection device according to the energy storage principle, which uses the energy stored in the liquid.

The oil burners according to the invention are based on the energy storage principle working injector provided a defined amount of oil is suddenly injected into the combustion chamber.

The injection devices working according to the energy storage principle can be divided into two subgroups, the Injectors that are in the accelerated fuel use stored energy, and those based on the solid-state energy storage principle work. In the latter type of injectors is an initial partial stroke of the conveyor element the injection pump is provided, in which the displacement of the Fuel does not result in pressure build-up, whereby the Conveyor element stroke serving for energy storage advantageously through a storage volume e.g. in the form of an empty volume and a stop element is determined, which is based on the following of the exemplary embodiments is different can be designed, for example in the form of a spring-loaded Membrane or a spring-loaded piston element, against which fuel is pumped and which is on a stroke "X" allow the delivery element to displace fuel; first then when the spring-loaded element is on during the displacement one e.g. abuts a firm stop, there is an abrupt pressure build-up generated in the fuel, so that a displacement of the fuel in the direction of the injector.

The following fuel injectors described in detail with reference to the drawings are known from WO 93/18297, but their structure is special for the reasons mentioned above is suitable for use in an oil burner.

1 has an electromagnetic driven reciprocating pump 1 on a delivery line 2 is connected to an injection nozzle device 3.

From the delivery line 2 branches off an intake line 4, which with a fuel reservoir 5 (tank) is connected. In addition, the delivery line 2 is approximately in the area of the connection the suction line 4 a volume storage element 6 via a line 7 connected.

The pump 1 is designed as a piston pump and has a housing 8, in which a magnet coil 9 is mounted, one in the area of the coil passage arranged anchor 10, which as a cylindrical body, for example, designed as a full body and in one Housing bore 11 is guided, which is in the region of the central longitudinal axis the ring coil 9 is located, and by means of a compression spring 12 is pressed into a starting position in which it is on Bottom 11a of the housing bore 11 abuts. The is supported Compression spring 12 on the end face of the injection nozzle Armature 10 and a ring step opposite this end face 13 of the housing bore 11. The spring 12 includes with play a delivery piston 14 which is connected to the armature 10 by the spring 12 loaded anchor face, e.g. in one piece, connected is. The delivery piston 14 plunges relatively deep into one cylindrical fuel delivery chamber 15, which is coaxial in axial Extension of the housing bore 11 is formed in the pump housing 8 and is in transmission connection with the pressure line 2 stands. Due to the immersion depth, pressure drops can occur during of the sudden pressure rise can be avoided, the Manufacturing tolerances between the piston 14 and cylinder 15 even can be relatively large, e.g. only in the hundredth of a millimeter range need to lie, so that the manufacturing cost is low.

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

The storage element 6 has e.g. two-part design Housing 22, in its cavity as an organ to be displaced a membrane 23 is stretched, which from the cavity a pressure line side, separates the space filled with fuel, and which divides the cavity into two halves when relaxed, which are sealed against each other by the membrane. At the the Line 7 facing away from the side of the membrane 23 engages in an empty space, the storage volume, a spring force acting on it e.g. a spring 24, which acts as a return spring for the membrane 23 is set up. The spring 24 is opposite to the membrane End on an inner wall of the cylindrical widened empty cavity stored. The empty cavity of the housing 22 is delimited by an arched wall, the one Forms stop surface 22a for the membrane 23.

The coil 9 of the pump 1 is connected to a control device 26, that as electronic control for the injector serves.

The armature 10 is in the de-energized state of the coil 9 Pump 1 by the bias of the spring 12 on the bottom 11a. The Fuel feed valve 16 is closed and the storage membrane 23 is by the spring 24 in its from the stop surface 22a held in the withdrawn position in the housing cavity.

When the coil 9 is activated via the control device 26 the armature 10 with piston 14 against the force of the spring 12 in the direction Injector 3 moves. This displaces the one with the anchor 10 connected delivery pistons 14 from the delivery cylinder 15 fuel into the space of the storage element 6. The spring forces the springs 12, 24 are relatively soft, so that fuel displaced by the delivery piston 14 during the first partial stroke of the delivery piston 14 with almost no resistance Storage membrane 23 presses into the empty space. This allows the Anchor 10 are initially accelerated up almost without resistance the storage volume or empty space volume of the storage element 6 exhausted by impact of the membrane 23 on the vault wall 22a is. This suddenly displaces the fuel stopped and the fuel due to the already high kinetic Energy of the delivery piston 14 suddenly compressed. The Kinetic energy of the armature 10 with the delivery piston 14 acts the liquid. This creates a pressure surge caused by the Pressure line 2 migrates to the nozzle 3 and there for spraying Fuel leads.

For the end of the delivery, the coil 9 is switched off. Of the Armature 10 is moved back to the bottom 11a by the spring 12. The amount of liquid stored in the storage device 6 via lines 7 and 2 in the feed cylinder 15 sucked back and the membrane 23 due to the action of Spring 24 pushed back into its original position. At the same time opens the fuel feed valve 16 so that fuel from the Tank 5 is sucked up.

It is expedient in the pressure line 2 between the injection valve 3 and the branches 4, 7 a valve 16a is arranged, a stand pressure in the injector side space which e.g. is higher than the vapor pressure of the liquid at maximum temperature, so that bubbles form is prevented. The parking pressure valve can e.g. as the Valve 16 may be formed.

As a displacement element for the memory element 6 can instead of Membrane 23 also a storage piston 31 can be used. The attack, which suddenly stops saving in this case be adjustable according to the invention so that the path length the acceleration stroke of armature 10 and delivery piston 14 can be changed. This adjustment is for example carried out manually by an adjusting element, which has a Cable 40 transmits the adjustment path to a displacement piston 31. Alternatively, the adjustment can be carried out expediently the control device 26, for example by means of an actuating magnet being controlled. Figure 2 shows e.g. an embodiment of the storage element 6 with a cable 40 adjustable displacement piston 31.

2 has a cylindrical housing 30, which can be formed integrally with the pressure line 2. A storage piston 31 is used as the organ to be displaced a tight fit on the inner wall of the cylinder housing 30 is guided so that no significant leakage can occur, an empty volume 33c is provided in the cylinder 30, into which the piston 31 can be displaced. Existing leakage fluid can through a drain hole 32 from the empty volume 33c escape and becomes the fuel tank 5 (see FIG. 1) fed. The drain hole 32 is in the cylinder wall of the Housing 30 formed in the region of the housing cover 33, the opposite the housing wall 33a, which is integrally formed with a wall section of the pressure line 2. The drain hole 32 extends approximately radially to the central longitudinal axis 33b of the cylindrical Housing 30.

Between the inside of the housing cover 33 and this End face of the piston 31 opposite the wall is one Compression spring 34 clamped, the piston 31 in its rest position presses against the opposite housing end wall 33a, in which has a bore 35 formed in the central longitudinal axis 33b of the housing 30 and into the pressure line 2 flows.

The housing cover 33 of the housing 30 is in the axial direction elongated tubular, and in the passage of the extension tube 36 a piston pin 37 is slidably guided like a piston has a ring 38 at the end located in space 33c. Against the bottom of the ring 38 pushes the piston 31 when it is out its rest position in the direction of the housing cover 33 moves becomes. This stop element 37 is biased by a spring 39 stored. The spring 39 is supported for this purpose on the one hand on the inside of the cover 33 and on the other hand the ring step of the ring 38 of the bolt 37. On the outside of the Part of the bolt 37 arranged in the cylinder 30 is the cable pull 40 attached. The stop pin 37 is in via the cable 40 Adjustable in the direction of the central longitudinal axis 33b of the housing 30, so that the possible stroke of the piston 31 of the position of Stop ring 38 can be varied accordingly. The stop pin 37 can, depending on the required acceleration stroke the armature 10 of the pump 1 (Fig. 1) can be adjusted.

The mode of operation of the memory element 6 according to FIG. 2 corresponds essentially that of the memory element 6 Fig. 1. In a first partial stroke of the delivery piston 14 and the Armature 10 (FIG. 1) becomes the storage piston 31 of the storage element 6 by displaced fuel from its shown in Fig. 2 Rest position pressed, the return spring 34 relative is soft, so that the 10th by the anchor seated delivery piston 14 moving fuel with almost no resistance of the storage piston 31 can be displaced. This will the armature 10 with delivery piston 14 almost on part of the stroke resistance-free, i.e. essentially only against the spring force the springs 12, 34 accelerate until the storage piston 31 with its spring-loaded face against the stop ring 38 bumps, which in the delivery cylinder 15 and in the pressure line 2 located fuel suddenly due to the high kinetic Energy of the armature 10 and delivery piston 14 is compressed and this kinetic energy is transferred to the liquid. Of the resulting pressure surge then leads to the spraying of Fuel through the nozzle 3.

The adjustable stop pin 37 is also suitable for exclusive Control of the amount of fuel to be injected.

According to a further advantageous embodiment of the invention there is provision for the fuel feed valve (valve 16 in FIG. 1) to be designed so that it also acts as a storage element (corresponding to storage element 6 in Fig. 1 and 2), so that fuel almost resistance-free on the first partial stroke of the delivery piston from the delivery cylinder 15 and the pressure line 2 into a storage volume is derived, this storage element also determines the distance of the first partial stroke of the delivery piston 14. Fig. 3 shows a first embodiment of such Trained fuel feed valve, which is also the function a storage element for determining the first partial stroke of the Delivery piston guaranteed. An advantage of this space-saving Variant of the invention is that instead of two Components according to FIGS. 1 and 2, namely a fuel feed valve and a separate storage element, just a single one Component is present.

The valve 50 comprises a substantially cylindrical one Housing 51, in one piece in the illustrated embodiment is formed with the pressure line 2. In the case 51 a through bore 52 is made, the one Pressure line side section 53, which via an opening 53a in the pressure line 2 opens, and a suction-side section 53b, which is connected to the feed line to the fuel tank 5 (FIG. 1) is connected. Between the two coaxial holes 53 and 53b in the housing 51 is a radially expanded valve space 54 formed, which receives a shut-off valve element 55. The valve element 55 consists of a circular disk 56 large diameter and a circular disc 57 small diameter, wherein both circular disks are integrally formed and with the circular disk 57 of smaller diameter on the side of the bore section 53 is arranged. A valve body return spring 58 presses the valve element 55 against in the idle state the end face 59 of the valve chamber 54 on the pressure line side, the spring 58 on the one hand on the disk 56 of the valve element 55 and on the other hand supports at the bottom of a ring step 60, that centrally in the face 59 of the valve chamber 54 opposite end face 61 is arranged. The disk 56 can thus seal against the end face 61 of the valve chamber 54 arrive.

The bore section 53 of the central longitudinal bore 52 is in Connection to the valve chamber 54 in the housing wall 51 arranged grooves or grooves 62, which in the direction of the valve space 54 can be designed to expand in a funnel shape (see FIG. 3).

The valve element lies in the starting position shown in FIG. 3 55 by the action of the spring 58 with the disk 57 on the end face 59 of the valve chamber 54. In this position the reservoir section 53b is above the valve space 54 and the grooves 62 and the bore section 53 in Flow connection with the pressure line 2 and the delivery cylinder 15, wherein the symbolically shown fuel tank device 5 an empty space volume or storage volume in which Fuel can be displaced, provides. Will the Delivery piston 14 due to excitation of the coil in the direction of the injection nozzle (Arrow 3a) accelerated, the displaced fuel almost resistance-free through the bore section 53, the Grooves or grooves 62, the valve chamber 54 and the inlet bore 53b flow into the fuel storage container 5. The flow conditions of the valve 50 are designed so that at Reaching a certain flow rate of the fuel the flow forces around the fuel Valve element 55 become larger than the biasing force of the spring 58 so that it is pressed to bore 53b. Closes the valve element 55 with the disk 56 the inlet cross section the bore 53b or the recess of the ring step 60, which is a abrupt transfer of the kinetic energy of the armature 10 with piston 14 on the fuel in the feed cylinder 15 and in the Pressure line 2 has the result that fuel through the nozzle 3rd (see Fig. 1) is hosed. In this version of the valve device 50 is the energy storage path of the armature 10 with the piston 14 controllable by the excitation of the coil. The valve element 55 lifts by the pressure of the spring 58 from the mouth of the feed line 53b again when the piston 14 or the armature 10 moves back, so that fuel can be sucked out of the tank 5.

FIG. 4 shows a variant of the above with reference to FIG. 3 Component described, the function of both the fuel supply as well as the control of fuel injection takes over, in addition the one serving for energy storage Partial stroke of the delivery piston can also be controlled via the component is. For this purpose, an electrically controllable valve 70 used.

At the beginning of pressure line 2, in the immediate vicinity of Druckbzw. Delivery chamber 15 of pump 1 has pressure line 2 Opening 71 to which the fuel supply line 4 is connected into which the electrically controllable valve 70 is inserted is. The valve 70 has a spring-loaded in a valve housing 77 Valve plate 72, which is firmly connected to an armature 73 is. The armature 73 has a central axis bore 74 and at least a transverse bore 75 in the area of Valve plate 72. In the rest position, valve 70 is open, by the armature 73 being pressed against the plate 72 Spring 76 is pressed into a pressure line end position, in of the fuel of the storage container, not shown the holes 75 and 74 and the pressure line opening 71 with the Fuel of the pressure chambers 15, 2 is connected.

In the housing 77, a coil 78 is also arranged, which Anchor 73 surrounds at a distance.

According to the invention, the injection process takes place as follows. At completely filled pressure line 2, the solenoid 9 of the Pump 1 excited, causing the armature delivery piston element 10, 14 of the Pump 1 is accelerated out of its rest position. The from Piston 14 displaced fuel flows through the pressure line opening 71, the central bore 74, the transverse bore 75 around the Valve plate 72 around and in the tank-side part of the line 4 to the fuel tank. At some point valve 70 is activated by energizing coil 78 and armature 73 is moved until the valve plate 72 assumes its valve seat and blocked the fuel path. The pressure line opening 71 is blocked suddenly or very quickly, so that none further fuel can escape via line 4. Anchor 10 with delivery piston 14 are braked suddenly as a result and give the stored kinetic energy to the incompressible Fuel, which results in a pressure surge the fuel from the pressure line 2 via the injection valve 3 is hosed, as in the other embodiments the invention of the armature 10 with piston 14 either its full Has reached the delivery stroke or is still being moved. The injector 3 is hydraulically controlled in a manner known per se and spring-loaded. The control of the valve 70 is preferably carried out via control electronics that work together the pump 1 and the shut-off valve 70 are operated.

Fig. 5 shows a modification of the valve of Fig. 3. The integral Storage element inlet valve 90 has a housing 91, that is constructed in a unitary manner with the housing 8 of the pump 1 and the pressure line 2. In the housing 91 is a central longitudinal bore 92 introduced, the one end via an opening 93a in the pressure line 2 and otherwise in a cylindrical Valve chamber 93 opens, with channels 94 similar to the channels 62 from FIG. 3 lead from bore 92 to valve chamber 93. The Valve element is formed in two parts and includes an in Valve chamber 93 guided cylinder 95, in the cylindrical, through a central stage bore a piston 96 slidably to be led. In the outer surface of the cylinder 95 are axially parallel grooves 97 are formed. The cylinder 95 is pressed into its rest position by a spring 98, in which he with his one end face on the tank side Bottom of the valve chamber 93 sits in the one of the fuel tank Coming fuel supply line 99 opens. In the A bore for receiving the piston 96 is located on the tank side 100, the piston 96 against the pressure line side bottom of the Valve chamber 93 presses so that the bore 92 is covered, with a free space in the interior of the cylinder 95 on the tank side 95a for the piston 96 is formed.

The valve 90 works as follows. If the delivery piston 14 executes a suction stroke, fuel from line 99 becomes thereby sucked in that the cylinder 95 from the tank side bottom surface of the valve chamber 93 by the negative pressure against the pressure the spring 98 is lifted off, so that fuel via the longitudinal grooves 97, the valve chamber 93 and the channels 94 and the bore 92 can flow into the pressure line 2. In this process lies the piston 96, as shown in Fig. 5, on the pressure line side Bottom of the valve space 93. At the end of the suction stroke cylinder 95 is moved by spring 98 into that shown in FIG Position pressed in which the cylinder 95 again on the tank side Bottom of the valve chamber 93 lies sealingly.

At the beginning of the delivery stroke of the delivery piston 14, the delivery cylinder becomes 95 guided pistons 96 due to the relatively soft design the spring force of the spring 100 from its abutment on the pressure line side Bottom of the valve space 93 moved away and in the Free space 95a is pressed, the resulting additional ones Space in the valve space 93 Fuel from the pressure space 15, 2 flows, which displaces during the conveying movement of the delivery piston 14 being, on the tank-side end of the piston 96 from piston 96 fuel via line 99 into the tank is pushed back. The delivery stroke of the delivery piston 14 is in that the piston 96 with its tank-side of of the spring 100 loaded end face at the step in the Center longitudinal bore of the piston 95 strikes. As a result of this abrupt termination of the essentially resistance-free acceleration stroke the armature 10 with delivery piston 14 is the Formation of a very steep pressure rise in the pressure line 2 causes fuel at high pressure through the nozzle 3rd is hosed.

According to a further variant of the invention it is provided that To design the storage element 6 as a unit with the delivery piston the reciprocating pump 1. A corresponding embodiment is shown in Fig. 6. A serves as a storage element Accumulator piston 80 in a pressure line-side first Central longitudinal axis step bore section 14b one through centrally the piston 14 and the armature 10 against stepped bore 14a a stop on the pressure line side (not shown) of a spring 81 is pressed. The piston 80 projects in the Rest position with its one end face in the pressure chamber 15. The bore portion 14b receiving the accumulator piston 80 in Delivery piston 14 sits after armature 14c toward armature 10 in a further stepped bore section 14d, on the Stage 14e the compression spring 81 is supported against the armature side End face of the piston 80 presses. The bore 14a finally penetrates anchor 10 and after stage 14e opens into the empty armature space 11, so that air is displaced can.

The memory element of this embodiment works like follows. On a first part of the stroke of the delivery piston 14, the Energy storage path, the storage piston 80 in the for Piston provided bore of the delivery piston 14 is pushed in, whereby an additional space for the displaced on the pressure chamber side Fuel is available so that the armature 10 during first stroke section together with the delivery piston 14 substantially can be accelerated without resistance. The no-resistance Acceleration of armature 10 and delivery piston 14 is ended when the anchor-side end face of the accumulator piston 80 against the annular shoulder 14c of the stepped bore 14a is coming. The consequence of this is a sudden increase in pressure, through which fuel is sprayed through the nozzle 3.

The variant described below with reference to FIGS. 7 and 8 the injection device according to the invention has a structural Unit of electrically driven reciprocating pump and lifting gear on.

In the embodiment shown in FIGS. 7 and 8 is a Hydraulic valve as well as the pump and the pressure line 2 in one common housing 121 housed. The function as well as the essential structure of the pump with electromagnetic drive corresponds essentially to the previously described embodiments the pump 1 of the device according to the invention, wherein the fuel intake takes place via a valve 122 which is fitted in the pump housing 121 and with the pressure line 2 is connected (Fig. 7).

The valve 122 closes in the exemplary embodiment shown automatically due to the Bernoulli effect on a specific one Flow rate. The one during the acceleration phase fuel flowing through the pressure line 2 passes through a Gap 123 in the valve chamber 124. Between the valve cone 125 and the associated valve seat is left with a narrow annular gap, which is determined by appropriate design of the valve cone 125 adjustable spring 126 can be adjusted. fuel flows through this annular gap and creates there after Bernoulli a lower static pressure than in the environment. At a certain flow velocity is the static pressure in the Annular gap has dropped so far that valve cone 125 is tightened is and the valve 122 closes, causing the Fuel pressure surge required via the injector is produced. The pressure line 2 leading to the injection nozzle is connected to the output of a check valve 127, the is also structurally combined with the housing 121.

The valve cone 128 of the valve 127 is a by bias Spring 129 pressed against the associated valve seat, the Spring 129 is designed so that valve 127 is closed, if the pressure in the pressure line 2 is below that Value that leads to an emission of fuel over the Injector leads, which is indirectly connected to the valve 127 is. The check valve 127 also causes blistering avoided in the pressure line 2 to the injector valve, because the non-return valve creates a stand pressure in the pressure line guaranteed between the injector and the check valve can be higher than the vapor pressure of the fuel liquid is.

The armature 10 is axially parallel in this embodiment Slots 130 and 131 of different depths in the jacket provided that on the circumference of the substantially cylindrical Anchor are arranged distributed. These slots prevent that Formation of eddy currents when exciting the solenoid 9 and thus contribute to energy savings. With a line 120, which leads from the armature space 11 through the housing 121 to the outside, leak oil that has penetrated into the armature space can be extracted.

The injection pump armature is reset in the Rule using the provided return spring. To great Achieving spray frequencies is the reset time of the armature to keep small. This can be done, for example, by a corresponding Realize the spring force of the return spring. With however, a reduction in the reset time increases the speed of impact of the anchor at the anchor stop. Disadvantageous the associated wear and / or that Bouncing the anchor on the anchor stop, reducing the total working time is enlarged. An object of the invention is therefore in the fall time of the anchor to the rest position to keep small. According to the invention, this goal is achieved by e.g. hydraulic damping of the armature return movement in the reached the last part of this movement.

Fig. 9 shows an embodiment of the injection pump, which in essentially has the structure of the injection pump 1 according to FIG. 1. For the hydraulic damping is like a piston cylinder arrangement at the back of the anchor 10 centrally cylindrical projection 10a formed in the last section the armature return movement in a blind cylinder bore 11b in the floor 11a suitably occurs, which on the stop surface lla is formed for the armature 10 in the housing 8. Anchor 10 are longitudinal grooves 10b formed, the anchor back space 11 with the anchor front space 11 connect. There is a medium in room 11, e.g. Air or Fuel generated by the movement of the armature 10 through the grooves 10b can flow. The depth of the blind cylinder bore 11b corresponds approximately the length of the projection 10a (dimension Y in FIG. 12). The fact that the projection 10a in the blind cylinder bore 11b can plunge, the armature return movement in the last section greatly delayed, creating the desired hydraulic Damping the armature return movement by displacing the medium from room llb.

10a shows a variant of the hydraulic damping. Also in this embodiment, that of the delivery piston 14 penetrated pump chamber 11 in front of the anchor 10 connected to the the anchor back adjacent space 11, through holes 10d that in the area of the back of the anchor in a central Overflow channel 10c open. A central pin 8a of a shock absorber 8b protrudes with its cone tip 8c towards the mouth of the overflow channel 10c, a hole 8d passes through in the rear Floor 11a, which opens into a damping space 8e, and ends in Insulation room with a ring 8f, which has a larger diameter has than the hole 8d. One on the floor of the damping room supporting spring 8g presses against the ring 8f and thus the Pin 8a in its rest position (Fig. 10a). A channel 8h connects the insulation space 8e with the rear anchor space 11. Die Channels 10c and 10d allow the armature 10 to be almost resistance-free Movement during the acceleration phase.

The damping device 8b is in the acceleration movement of the anchor 10 ineffective, so that no impairment of the Lifting phase. The mouth hits during the return movement the overflow channel to the cone tip 8c and is closed, so that the flow through the channels 10c and 10d is interrupted becomes. The armature 10 presses the pin 8a against the spring force and against the medium in room 8e, which is also in the Room 11 is located and flows out via channel 8h into room 11. The currents and spring forces are chosen so that a optimal damping is guaranteed.

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

According to a further advantageous embodiment of the invention Injector is provided in the return spring 12 of the armature 10 stored energy during the return movement of the anchor 10 to be used to advantage. This can According to the invention, for example, take place in that the anchor operated at the reset a pumping device for the Fuel supply to the injector for stabilization system and to prevent blistering can be. 11 shows a corresponding exemplary embodiment one connected to the fuel injection pump 1 second pump 260.

The fuel injector shown in Fig. 11 is in the 4 are designed according to FIG. and drain control element for controlling the first partial stroke of the delivery piston 14. The second pump 260 is connected to the rear bottom 11a of the pump housing 8 connected. in the individually, the second pump 260 includes a housing 261 which is connected to the housing 8 of the injection pump is connected, and in the Pump chamber 261b a pump piston 262 is arranged, the Piston rod 262a projects into the working space 11 of the armature 10, the piston 262 is acted upon by a return spring 263, which is located on the housing base 261a in the region of an outlet 264 supports.

In addition, the pump chamber 261b of the housing stands over a supply line 265 in connection with a storage container 266. In a check valve 267 is inserted into the feed line 265, the structure of which is similar to that of valve 16 in FIG. 1.

The second pump 260 works as follows. If the anchor 10 the injection pump 1 during its working stroke towards the injection nozzle 3 moves, the pump chamber 11 in the housing 8 behind the armature 10 increased in volume, whereby the pump piston 262 is moved in the direction of the armature 10 and finally by the action of the return spring 263 in it Rest position is transferred. The storage container becomes 266 Via valve 267 oil into the working space 261b of the second pump 260 sucked in. During the return movement of the armature 10 of the Pump 1 in the direction of its stop 11a becomes the pump piston 262 at least on part of the return path of the armature 10 pushed into the pump chamber 261b. This is due to the pump pressure the valve 267 is closed and it will be that of the second pump pumped medium via the outlet 264 in the direction of arrow 264a from the pump.

The second pump 260 can be used as a fuel back pressure pump are, wherein the fuel of the valve device 70 is supplied can be. It is advantageous that the pump 260 a Stand pressure in the fuel supply system can generate that vapor bubble formation e.g. when the entire system heats up counteracts.

In addition, the formation of the additional effect according to the invention Pump 260 on pump 1 quick 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 that shown in Figure 9. The blind cylinder bore 11b after Figure 12a is larger in diameter than the diameter of the cylindrical projection 10a. The projection 10a is from a sealing lip ring projecting in the direction of the blind cylinder bore 11b 10e surrounded by an elastic material which in the blind cylinder bore 11b fits. An insertion slope on the Mouth of the blind cylinder bore 11b facilitates the entry of the Lips the sealing lip ring 10e into the blind cylinder bore 11b. This damping device provides good damping when Stop of the armature 10 and hampers the acceleration stroke of the Anchor not. The elastic damping element 10e with axially parallel protruding sealing lips appear during the return stroke of the armature 10 in the blind cylinder bore 11b and lies against the outside of the inner wall of the blind cylinder bore 11b.

The blind cylinder bore 11b according to FIG. 12b has a diameter also larger than the cylindrical projection 10a. A sealing ring 10f made of elastic material sits on the Wall of the blind cylinder bore 11b and points in the area of Mouth inward-facing sealing lips 10g. In the elastic Sealing element 10f dips the cylindrical projection 10a a piston-like, the sealing lips 10g due to the outflowing Damping medium against the cylindrical projection 10a be pressed so that a particularly good damping of the armature 10 is reached.

FIG. 13 shows a likewise compact design of the invention electrically operated piston pump with integrated stop valve. It is in a cylindrical multi-part housing 200 in one of an outer jacket 200a and a cylindrical inner jacket 200b and a tank side End wall 200c and a pressure line end wall 200d delimited interior 202, a coil 201 is arranged. The from Inner jacket 200b surrounding cylindrical interior 202 of the housing 200 is extended by a radially inward Ring 203 in a tank side and a pressure line side Interior area divided. Pressure line side is against Ring edge of the ring 203 a positive and firm in this Set inside ring bead 204 of a piston 205, the piston 205 spacing the ring opening 206 of the ring 203 reaches through and into the tank-side area of the interior 202 protrudes. The piston 205 is from a through bore 207 penetrates, which extends in the tank-side end region of the piston is formed and there stores a valve 208, which by a Coil spring 209 towards the tank side for the closed position is pressed against a valve seat 209a, through with the Exposure to pressure from the tank side opened can be.

On the inside of the tank 202 of the interior 202 located part of the piston 205 sits positively and slidably a pump cylinder 210 of the reciprocating pump, which by a one end on the ring 203 and the other end on a ring step 212 of the cylinder 210 supporting coil spring 211 with its Tank-side end face 214 against a ring step 213 in Inner space 202 is pressed, with a protruding from the end face 214 Valve nozzle 215 with a radial distance a bit in the in this area radially narrowed interior 202a protrudes and where the end face of the cylinder 210 in the pressure line side Distance from the ring 203 is arranged and thus a movement space is created for the cylinder 210. The form-fitting on the Inner walls of the interior 202 are guided cylinders 210 has axially parallel, frontal open longitudinal grooves 216 in the Lateral surface, the function of which is explained below.

The continuous through the pump cylinder 210, the piston 205 receiving bore 217 is stored on the tank side of the piston 205 upstream tappet valve, the tappet disc 218 at a distance from the face surface of the piston 205 in a short Hole extension is arranged and its pushrod 219th the narrowed bore 217a in the valve stub 215, against the Supporting inner wall of the bore 217a, reaches through and into the narrowed interior 202a protrudes.

At the free end of the plunger style 219 is expediently one Plate 220 attached, which has holes 221, their function will be explained below, the plunger stem 219 still on Extends beyond the plate 220 and against the tank side Bottom surface 222 of the interior 202a abuts. Here is the pestle handle 219 chosen so long that the plunger plate 218 from its Valve seat, the pressure line side opening 223 of the narrowed Bore 217a is lifted off, so that a certain gap "X" is formed whose meaning and purpose is explained below. A coil spring 224 stabilizes this position of the tappet valve in the shown idle position of the reciprocating pump, in which the spring 224 ends on the end face 214 of the Cylinder 210 and otherwise supported against the plate 220.

Bores extending axially parallel extend from the bottom surface 222 225 into the bottom wall and open into an axial valve chamber 226, in which one of a coil spring 228 in the tank direction Valve plate 229 pressed against a valve seat 227 is the grooves 230 which can be covered peripherally by the valve seat 227 has, so that the valve through a tank connection side Pressure against the load of the spring 228 can be opened and created a passage from the valve chamber 226 to the bores 225 becomes.

The valve chamber 226 is located with one leading to the fuel tank Fuel line in connection (not shown); to the end wall 200d on the pressure line side or to an extended one A pressure line is attached to the inner wall 200b (not shown), which leads to the spray valve. In the The arrows drawn in FIG. 13 indicate the path of the fuel on.

The reciprocating pump shown in Figure 13 works like follows. By energizing the coil 201, the cylinder 210 almost from the shown rest position towards the pressure line accelerated without resistance, from room 202 over the Grooves 216 and from the bore 217 or the tappet plate space Fuel flows out toward interior 202a. The accelerated Movement ends with the impact of the valve seat 223 the valve plate 218 abruptly, so that the stored energy of the Cylinder 210 on the fuel in the plunger vestibule is transmitted. The valve 208 is opened and the Pressure on the one in the bore 207 or in the pressure line Fuel propagated, causing a splash of Fuel is injected through the injector. If the excitement is not yet switched off, fuel is sprayed off for as long as how the cylinder is moved. The tappet valve 218, 219 is taken along by the cylinder 210 and a Vacuum in the interior 202, 202a and in the holes 225 and the anteroom of the valve chamber delimited by valve 229 226 so that the valve 229 is opened. The fuel flows coming from the tank through the peripheral grooves 230 in the valve plate 229, the anteroom of the valve chamber 226, the bores 225 and the Holes 221 in the plate 220 in the interior 202a and over the Grooves 216 in the interior 202. After switching off the excitation the spring 211 returns the cylinder to its rest or home position pushed back, previously the pushrod 219 hits against the bottom wall 222 and opens the tappet valve is so that fuel through the space between the Tappet stem and bore 217a in the plunger plate vestibule 217 can flow. The valve 208 remains closed. It works as a parking pressure valve and stops in between the injection valve (not shown) and the valve plate 208, a space pressure with fuel in the fuel upright, e.g. is higher than the vapor pressure of the liquid at maximum temperature, so that bubbles do not form can be.

In the embodiment of the injection pump shown in FIG. 14, which is the same as the embodiment of FIG. 13, which is why The same parts are provided with the same reference numerals Piston 205 formed integrally with the end wall 200d and the standing pressure valve 208, 209, which in a pipe socket 208a is housed, covers the mouth of the discharge line bore 207 going through the piston 205.

The sliding pump cylinder 210 acting as an anchor is for one simple possibility of mounting the valve lifter 218, 219 constructed in several parts. Since the multiple parts are not essential to the invention is the structure of the cylinder 210 is not closer described.

The plunger stem 219 is relatively short and can be over the tank-side end ring surface 214 of the cylinder 210 only by that Protrude valve clearance. The end ring surface 214 abuts in the area the end wall 200c against a plastic block stored there 231, which has through holes 232, the peripheral open into grooves 233, which with the tank-side interior 202 are connected, with 202 holes from the tank-side interior 234 to the enlarged bore area of bore 217 in Guide cylinder 210. The holes 232 open into the tank leading axial valve chamber 226, which in a pipe socket 226a is housed.

In this embodiment of the invention, the tappet valve 218, 219 not spring loaded. It works due to inertial forces, the plunger stem approximately form-fitting in the narrowed bore 217a sits. In the shown in Fig. 14 The tappet valve is positioned by the on the tappet plate 218 acting pressure prevailing in rooms 202, 217, 207 pressed against the plastic block 231. If the cylinder 210 accelerates, the tappet valve remains in this position until it is taken away from the valve seat 223. With the return movement of the armature cylinder 210, the plunger stem 219 abuts against the Plastic block 231 so that the tappet valve is back in its shown starting position arrives.

The hole extension expediently forms the hole 217, in which the tappet plate 218 is received, on the pressure line side a ring stage 235, which is in the rest position of the Tappet valve only a short distance in front of tappet plate 218 is located and against which the plunger plate 218 hits when the Tappet due to inertia during the return movement of the cylinder 210 lifts off the valve seat and / or the valve from the plastic block 231 rebounded during the return movement of the cylinder 210 should be. In the end face of the ring step 235 are Recesses 235a introduced, which has an unimpeded flow ensure the fuel. In this way is the rest position of the tappet valve ensured with simple means.

During the acceleration of the armature cylinder 210 flows in this embodiment of the injection pump fuel from the pressure line-side interior 202 via the grooves 216 in the Tank-side interior 202 and from the bores 207, 217 through the recesses 235a past the plunger plate 218 through the Valve seat opening in the bores 235 also in the tank side Interior 202. The fuel is displaced by the closing of the tappet valve 218, 219 suddenly interrupted, whereby the intended pressure surge is achieved. With the return movement of the armature cylinder 210 opens the tappet valve 218, 219 and the fuel flows in the opposite direction.

So that the starting movement of the armature cylinder 210 from the rest position can not be affected is appropriate provided that the end ring surface 214 with a small distance "A" from the surface of the plastic block 231 (Fig. 15). Support webs 214a, which protrude from the end ring surface 214, lie on the surface of the plastic block 231 and provide the distance "A", so that no disturbing negative pressure effect at the start of the anchor cylinder 210 between the end ring surface 214 and the surface of the plastic block 231 occur can. Such support bars can be used for the same purpose be arranged on the end face of the pestle stem 219 (not shown). In addition, the distance "A" is chosen so small that a damping by squeezing during the return stroke of fuel from gap "A".

The embodiment of the reciprocating piston pump according to FIGS. 14 and 15 can with a simply constructed effective anchor damping device provided, which is shown in Fig. 16. Here the plunger stem 219 has one in its free end region Flange ring 219a on which the end face 214 a piece overlaps laterally and lie against the end face 214 can. In the surface of the plastic block 231 is one Flange ring 219a introduced corresponding recess 231a, in which the flange ring 219a fits approximately form-fitting, so that a piston-cylinder-shaped hydraulic damping device becomes. When the armature cylinder 210 is reset, the Flange ring 219a taken with the attachment from the end face 214. As soon as the flange ring 219a dips into the recess 231a, fuel is displaced from it and a deceleration of the Anchor cylinder 210 causes. When accelerating the armature cylinder 210 the anchor cylinder moves almost without resistance. The flange ring 219a and thus the tappet valve 218, 219 initially remains in the recess 231a until the Tappet valve is made through the valve seat.

The thickness of the flange ring 219a is expediently somewhat executed greater than the depth of the recess 231a, so that the Front ring surface 214 in the rest position of the armature cylinder 210 remains at a distance from the surface of the plastic block 231 and support bars are not required.

It is expedient in the end wall on the pressure line side 200d arranged a bore 236, the pressure line side Interior 202 leads to the outside and a nozzle on the outside 237 is set with a through hole 238. Through the Bore 236 and drain connector 237 can e.g. during the Start phase of the pump or burner fuel from the anchor cylinder 210 are pumped out, so that the pump and / or Fuel supply line can be flushed out of air bubbles. The sequence 236, 237 can also be used during the injection activity the pump fuel is washed around and thereby Heat is dissipated and bubbles are avoided.

It is expedient on the inner wall of the pressure line side Interior 202 a supported on the end wall 200b Compression spring 238 arranged against the acceleration of the armature cylinder 210, an end ring surface 239 of the armature cylinder only comes across when a large stroke for a large hosed down Amount of fuel is initiated. The feather is there compressed. During the return movement of the armature cylinder 210 gives the spring 238 its stored spring force to the armature cylinder 210, so that it accelerates accordingly in the rest position moves.

In the case of those described below with reference to FIGS. 17, 18, 19 Reciprocating pumps, cylinder 210 acts as a piston-like anchor element, that is liquid-tight in the inner cylinder 200b becomes.

One similar to the injection pump shown in FIG. 13 Injection pump 1 is shown in Fig. 17, the same Parts have the same reference numbers.

The piston partially seated in the armature cylinder bore 217 205a is not fastened to the end wall 200d on the pressure line side, but axially movable and part of the spray valve device 3. The injection valve 3 has a valve cap 3b, which in the front wall 200d of the housing 200 in the injection valve side Interior 202 is screwed gripping. The valve cap has an injection nozzle hole in the center 3d. The piston 205a covers in its rest position with a Diameter reduced face 205b the injector bore 3a from. The reduced surface area 205b goes with it a truncated cone 205c in the cylindrical part of the piston 205a about. The piston 205a is in the armature cylinder bore 217 from a compression spring 240 against the injector bore 3d pressed, the compression spring 240 against another in the intermediate cylinder 241 arranged in the armature cylinder bore 217 is supported, which bore 217 in an injector side and into a tank-side area. At least leads a bore 242 from the end face 212 through the armature cylinder 210 in the expanded cylinder bore space of the tank side Area of the bore 217 in which the tappet plate 218th is received, and a bore 243 through the armature cylinder 210 from the region of bore 217 on the injection nozzle side tank-side interior 202, with the central area of the anchor cylinder 210 form-fitting and almost liquid-tight the inner wall of the interior 202 sits. Preferably points the anchor cylinder in the tank-side area of the interior 202 Grooves on, the groove webs on the inner wall of the interior 202 and there are guides for the armature cylinder 210 form.

17 works as follows. Will the Anchor cylinder 210 initially from the rest position shown Accelerated without resistance, fuel flows through the bore 242 in the tank-side space of the bore 217 and from there into the Room 202a, with valve 229 remaining closed. It also flows Fuel through bore 243 from the injector side Bore 217 space in the tank side interior 202 and there - since the armature cylinder 210 from the end ring surface 213 has taken off - through the gap thus formed also in the room 202a. Once the tappet valve 218, 219 from the valve seat is detected, the desired pressure surge occurs on the injector side Interior 202. The pressure surge is applied to the cone surface of the truncated cone 205c transfers and lifts the piston 205 against the pressure of the spring 240 from the nozzle 3a so that fuel is hosed. At the same time, room 202a and a negative pressure in the tank-side interior 202, which also affects the Piston 205 acts, but is much less than the spring force the spring is 240, so that the piston is unaffected remains. The negative pressure opens the valve 229, so that Fuel is sucked up. The valve 229 closes due to the spring force of spring 228 again when the return movement the armature cylinder 210 begins, so that then by the armature cylinder movement Fuel into the spaces of bore 217 and Interior 202 is pushed. The function of the valve 292 corresponds the function of the same valve 229 in the Embodiment of the injection pump 1 according to FIG. 13.

Another embodiment of the injection pump according to the invention 1, in which the injection nozzle 3 directly in the end wall 200d is housed in the housing 200 of the injection pump 1, results from Fig. 18. This embodiment is similar to that of Fig. 17, which is why the same parts with the same reference numerals Marked are.

In this case, the valve cap 3b forms a valve seat 3c for a tappet valve 244, the valve plate 245 against the outside the valve seat 3c is pulled, and its tappet stem 246 the the valve seat 3c following cap bore 3d free or through Ridges 247 reach radially supported and freely through the Armature cylinder bore 217 goes and just before the expanded area the bore 217 ends in which the tappet plate 218 des Tappet valve 218, 219 is added. At the free end of the pestle handle 246 is a hole or marginal recess 248 Ring 248a attached, against which the injector side a compression spring 250 supports the other end of the end wall 200d of the housing 200 or on the valve cap 3b. It is essential in this embodiment that the armature cylinder 210 only the through hole 217 and no marginal Has grooves, but form-fitting on the inner wall of the Interior 202 is present.

This injection pump, which has no piston, works in contrast to the embodiment according to FIG. 17 as follows. If the tappet valve 218, 219 from the valve seat of the armature cylinder 210 is taken, the sudden pressure build-up in the fuel takes place in space 202, 217 and 3d, so that the tappet valve 244 to Spraying against the pressure of the return spring 250 opens. Subsequently hits the plunger plate 218 after a further stroke "H" on plunger stem 246 and holds valve 244 open.

An embodiment similar to the embodiment shown in FIG. 18 the injection pump 1 according to the invention is shown in FIG. 19 shown, the same parts again with the same reference numerals are designated.

The tappet stem 246 of the tappet valve 244 is made shorter and is sufficient in the rest position or starting position of the pump 1 only up to the injector-side end area of the armature cylinder bore 217. Accordingly, the return spring is 250 shortened. In addition, however, another compression spring presses 251 from the tank side against the ring 248a, which is at one end against a wall having a central bore 217d 217e supports the bore 217 in an injector side and a tank-side area divided over bore 217d communicate.

The spring supports this version of injection pump 1 251 the opening of the valve 244 as in the case of the embodiment 18, in which the belching through the valve plate 218 is supported, which hits the pushrod 246. The Springs then also hold valve 244 in the open position, as long as the spring pressure of the spring 250 or 251 causes this.

To increase the throughput of large burners in the area is between about 100 kg / h and 900 kg / h, it is advisable to provide an injector with multiple pumps 501 (Fig. 20), the fuel via a common delivery line 503 through the nozzle or valve 504 into the combustion chamber inject. The individual pumps are preferably out of cycle operated so that the fuel pulses with a very high frequency be injected into the combustion chamber 505. With a Larger number of pumps 501 can then be a quasi-continuous one Fuel supply can be achieved via a nozzle 504, the Throughput compared to traditional continuous work However, fuel supply devices are controlled much more precisely can be.

It is also possible to use several pump-nozzle units via one common nozzle assembly 506 (Fig. 21, 22) to connect. In one such a nozzle assembly 506 is a single one for each pump 501 Nozzle insert 504 provided. The pumps 501 can pulse circulate so that the individual fuel pulses on the nozzle inserts 504 all the way into the combustion chamber 505 , making the flame center in the burner a circular one Movement. This clearly shows that with the device according to the invention influenced parameters conventional burner controls cannot be accessed were.

Claims (69)

1. Oil burner for a heating installation with a combustion chamber, into which fuel is fed by a fuel supply element,
   characterized in that
   the fuel supply element is an injection device working according to the energy-storage principle and having a pump (1) and a nozzle device (3), designed such that the fuel and/or a reciprocating piston element of the pump (1) are accelerated during an acceleration phase and means are provided to interrupt the acceleration phase so that the energy stored in the fuel and/or the reciprocating piston element is converted into an injection pulse, such that a defined quantity of fuel is ejected abruptly.
2. Oil burner according to Claim 1,
   characterized in that
   the injection device is designed such that the quantity of fuel ejected by each injection pulse is adjustable.
3. Oil burner according to Claims 1 or 2,
   characterized in that
   the injection device is coupled to a control unit which controls the injection frequency in such a way that the said frequency is as different as possible from the resonance frequency of the combustion chamber.
4. Oil burner according to any of Claims 1 to 3,
   characterized in that
   an electronic regulator with a gas sensor to measure the combustion gases produced is provided, which, according to the signal from the gas sensor, regulates the injection frequency and/or the quantity injected.
5. Oil burner according to any of Claims 1 to 4,
   characterized in that
   several pumps (501) are provided, which are connected via a common supply line (503) to a single nozzle (504).
6. Oil burner according to Claims 1 to 4,
   characterized in that
   several pumps (501) are provided, each of which is connected via a supply line (503) to one nozzle (504) in each case, the said nozzles being arranged in a single nozzle assembly (506).
7. Oil burner according to Claims 1 to 6,
   characterized in that
   the injection valve operates according to the solid-body energy storage principle, whereby a reciprocating piston element moving in a pump cylinder of an electromagnetically driven reciprocating piston pump displaces portions of the fuel to be injected in the pump area before injection during a virtually resistance-free acceleration phase while the reciprocating piston element stores kinetic energy, the displacement is suddenly stopped by means which interrupt it so that a pressure pulse is produced in the fuel present in a closed pressure chamber, in which the stored kinetic energy of the reciprocating piston element is transferred directly to the fuel in the pressure chamber, and such that the pressure pulse is used to inject fuel through an injection nozzle device.
8. Oil burner according to Claim 7,
   characterized in that
   the means provided for interrupting the displacement and so producing the pressure pulse are located outside the guiding, liquid-tight contact zone between the reciprocating piston element and the cylinder of the reciprocating pump.
9. Oil burner according to Claims 7 or 8,
   characterized in that
   the means provided for interrupting the displacement and so producing the pressure pulse are in the form of a device (6, 50, 70, 90, 125, 218/223) comprising an end-stop.
10. Oil burner according to any of Claims 1 to 3,
    characterized in that
    the position of the end-stop (e.g. 37) is adjustable.
11. Oil burner according to one or more of Claims 7 to 10,
    characterized in that
    a volume storage element (6) is provided for the displacement of fuel during the acceleration phase.
12. Oil burner according to Claim 11,
    characterized in that
    it comprises an electromagnetically driven reciprocating piston pump (1) connected via a supply line (2) to an injection nozzle device (3), with a suction line (4) which branches off the supply line (2) and is connected to a fuel tank (5), and such that the volume storage element (6) is connected to the supply line (2) by a pipe (7).
13. Oil burner according to Claim 12,
    characterized in that
    the pump (1) has a housing (8) in which there is a toroidal coil (9) with an armature (10) positioned in the area of the coil's central passage, the said armature being a cylindrical body guided in a cylinder of the housing, being located in the area of the central longitudinal axis of the toroidal coil (9), and being pushed to a starting position by a compression spring (12), in which it rests against the bottom (11a) of the housing cylinder, with a discharge piston (14) attached to the end of the armature (10) facing the injection nozzle, the said piston penetrating relatively deeply into a cylindrical fuel supply chamber (15) arranged coaxially with the housing cylinder and connected to the pressure line (2).
14. Oil burner according to Claim 12 and/or Claim 13,
    characterized in that
    a non-return valve (16) is fitted in the suction line (4).
15. Oil burner according to one or more of Claims 11 to 14,
    characterized in that
    the storage element (6) comprises a housing (22) across whose hollow space a membrane (23) is stretched as the organ to be displaced, the said membrane separating off a space on the pressure-line side filled with fuel and, when in the unstressed condition, dividing the hollow space into two halves sealed off from one another by the membrane, such that on the side of the membrane facing away from the pipe (7) there is an empty space which has a domed wall (22a) as the contact surface for the membrane (23).
16. Oil burner according to Claim 15,
    characterized in that
    on the side of the membrane (23) facing away from the pipe (7), in the empty space, a spring (24) that acts on the membrane is arranged, which serves as a return spring for the membrane (23).
17. Oil burner according to one or more of Claims 12 to 16.
    characterized in that
    in the pressure line (2) between the injection valve (3) and the pressure chamber ahead of the branches (4, 7) a non-return valve (16a) is fitted, which creates a pressure zone in the space on the injection valve side so as to maintain a certain static pressure of the fuel.
18. Oil burner according to one or more of Claims 11 to 14,
    characterized in that
    a storage piston (31) guided in a cylindrical housing (30) that communicates with the pipe (7) is used as the displacement organ for the storage element (6), such that the cylinder (30) provides an empty volume (33c) into which the piston (31) can be displaced by the fuel.
19. Oil burner according to Claim 18,
    characterized in that
    a drain hole (32) is positioned in the area of the empty volume (33c).
20. Oil burner according to Claim 18 and/or Claim 19,
    characterized in that
    a compression spring (34) is located in the empty volume (33c), which pushes the piston (31) to its rest position against a housing wall (33a) on the pressure-line side.
21. Oil burner according to one or more of Claims 18 to 20,
    characterized in that
    an axially adjustable end-stop striker (37) for the piston (31) is positioned in the empty volume (33c), which passes through the housing wall and is connected to means of adjustment outside the housing.
22. Oil burner according to one or more of Claims 7 to 14 and 17,
    characterized in that
    the fuel supply valve (16) is also designed as a storage element valve (50).
23. Oil burner according to Claim 22,
    characterized in that
    the valve (50) comprises a cylindrical housing (51) in which a through-hole (52) is formed, which has a section (53) on the pressure-line side and a section (53b) on the suction side, between which there is a radially expanded valve space (54) that contains a cut-out valve element (55), the said valve element consisting in one piece of a circular disc (56) of larger diameter and a circular disc (57) of smaller diameter, such that the disc (57) is positioned on the side of the hole section (53) and a valve body return spring (58) presses the valve element in its rest position against a front flange surface (59) of the valve space (54) on the pressure line side, the said spring resting at one end against the circular disc (56) and at the other end against the bottom of an annular step (60) positioned centrally in the front surface (61) opposite the flange surface (59) of the valve space (54), so that the circular disc (56) can move to form a seal against the front surface (61) of the valve space (54) and such that the hole section (53) communicates with the valve space (54) via channels or grooves (62) arranged in the housing wall (51), the said grooves preferably widening out in a funnel shape towards the direction of the valve space (54).
24. Oil burner according to Claim 22,
    characterized in that
    it comprises an electromagnetically controlled valve (70).
25. Oil burner according to Claim 24,
    characterized in that
    the valve (70) comprises a toroidal coil (78) in a valve housing (77), inside which a cylindrical bore (74) is provided in which an armature (73) is guided, which is connected to a spring-loaded valve plate (72) and has at least one hole (75) extending transversely to the length of the armature in the area of the valve plate, such that by means of a spring (76) acting on the plate (72), the armature (73) is pushed to an end position on the pressure-line side in which the fuel communicates with the fuel in the pressure chambers (15, 2) via the holes (75) and (74) and the pressure-line opening (71).
26. Oil burner according to Claim 22,
    characterized in that
    it comprises an integral storage element/supply valve device (90) having a housing (91), half-way along whose length a hole (92) is formed which at one end opens via an aperture (93a) into the pressure line (2) and at the other end into a cylindrical valve space (93), such that in addition channels (94) lead from the hole (92) to the valve space (93) and such that the valve element is formed in two parts and comprises a cylinder (95) guided in the valve space (93), in whose cylindrical through-going central stepped bore a piston (96) is guided and can move, and such that grooves (97) running parallel to the axis are formed in the outer surface of the cylinder (95), and such that the cylinder (95) is pushed by a spring (98) to its rest position in which one of its end surfaces rests against the bottom of the valve space (93) on the tank side, into which a fuel supply line (99) coming from the fuel tank opens, and such that in the bore accommodating the piston (96) on the tank side there is a spring (100) which pushes the piston (96) against the bottom of the valve space (93) on the pressure-line side, so that the hole (92) is covered, so that in the interior space of the cylinder (95) on the tank side a free space (95a) for the piston (96) is formed.
27. Oil burner according to one or more of Claims 7 to 14,
    characterized in that
    the storage element (6) is formed integrally with the discharge piston (14) of the reciprocating piston pump (1).
28. Oil burner according to Claim 27,
    characterized in that
    a storage piston (80) serves as the storage element, which, in a first section (14b) of a central longitudinal axial stepped bore (14a) passing centrally through the piston (14) and the armature (10), is pushed by a spring (81) against an end-stop on the pressure-line side, such that in its rest position one end-face of the piston (80) projects into the pressure chamber (15) and the bore section (14b) in the discharge piston (14) accommodating the storage piston (80) continues after a step (14c) towards the armature (10) and on to a further stepped bore section (14d), against whose step (14e) a compression spring (81) rests, which presses against the end-face of the piston (80) on the armature side.
29. Oil burner according to Claim 11,
    characterized in that
    a hydraulic valve on the tank side, together with the pump (1) and the pressure line (2), are accommodated in a common housing (121) and a hydraulically controlled fuel supply valve (122) is fitted in the fuel supply line, the said valve closing automatically by virtue of the Bernoulli effect at a given through-flow rate.
30. Oil burner according to Claim 29,
    characterized in that
    the fuel passes via a gap (123) into a valve space (124) of the valve (122), in which a narrow annular gap is formed between a valve cone (125) and the associated valve seat, the said gap being adjustable by appropriate positioning of a spring (126) that acts on the valve cone (125).
31. Oil burner according to Claim 29 and/or Claim 30,
    characterized in that
    the pressure line (2) leading to the injection nozzle is connected to the outlet of a non-return valve (127) which is also integrated in the housing (121) and via which the fuel path leads to the injection nozzle (3).
32. Oil burner according to Claim 31,
    characterized in that
    the non-return valve (127) comprises a valve cone (128) which is pressed by the prestressing of a spring (129) against an associated valve seat, the spring (129) being positioned so that the valve (127) is closed when the pressure acting in the direction of the pressure line (2) is below a value which causes fuel to be ejected from the injection nozzle (3) connected indirectly to the valve (127).
33. Oil burner according to one or more of Claims 7 to 32,
    characterized in that
    it comprises a hydraulic damping device for the armature element (10) of the reciprocating piston pump.
34. Oil bumer according to Claim 33,
    characterized in that
    the hydraulic damping device is constructed as a piston and cylinder arrangement, such that on the armature (10) there is centrally a cylindrical projection (10a) which, in the last section of the armature's return motion, moves into a blind cylinder bore (11b) in the bottom (11a) of the cylinder, so that longitudinal grooves (10b) in the armature (10) connect the space behind the armature to the space ahead of the armature in the pump cylinder.
35. Oil burner according to Claim 33,
    characterized in that
    the pump space (11) ahead of the piston (10) through which the discharge piston (14) passes is connected to the space (11) at the back of the armature by holes (10d), which open into a central overflow channel (10c) in the area of the back of the armature, and a central pin (8a) of a shock-absorber (8b) projects with its conical point (8c) towards the opening of the overflow channel (10c).
36. Oil burner according to Claim 35,
    characterized in that
    the central pin (8a), at the back, passes through a hole (8d) in the bottom (11a) which opens into a damping space (8e), such that the pin (8a) ends in a ring (8f) inside the damping space, the said ring having a larger diameter than the hole (8d), and such that a spring (8g) rests against the bottom of the damping space, the said spring pressing against the ring (8f), and such that a channel (8h) connects the damping space (8a) to the space (11) at the back of the armature.
37. Oil burner according to Claim 35,
    characterized in that
    a through-going displacement hole (8i) is made centrally in the pin (8a), through which the damping medium can be pressed into the overflow channel (10c).
38. Oil burner according to Claim 33,
    characterized in that
    during its return motion the armature (10) acts as a pump device, which at the same time ensures that the armature (10) is damped.
39. Oil burner according to Claim 38,
    characterized in that
    a second pump (260) is connected to the bottom (11a) at the back of the pump housing (8), which comprises a housing (261) in whose pump space (261b) there is a pump piston (262) whose piston rod (262a) projects into the working space (11) of the armature (10), and the piston (262) is acted upon by a restoring spring (263) that rests against the bottom (26 la) of the housing in the area of an outlet (264).
40. Oil burner according to Claim 39,
    characterized in that
    the pump space (261b) communicates with a reservoir (266) via a supply line (265), and a non-return valve (267) is fitted in the said supply line (265).
41. Oil burner according to Claim 33 and/or Claim 34,
    characterized in that
    the blind cylinder bore (11b) has a diameter larger than that of the cylindrical projection (10a) or the blind cylinder bore (11b) comprises a sealing-lip ring (10e) or (10d), such that the sealing-lip ring forms the piston seal for the projection (10a).
42. Oil burner according to one or more of Claims 7 to 10 and 33 to 41,
    characterized in that
    the armature is formed as a pump cylinder (210), such that the interior space (202) of the housing is divided by an inwards-extending ring into interior space areas on the tank side and on the pressure-line side, and on the pressure-line side an annular bead (204) of a piston (205) of the reciprocating piston pump (1) rests form-closingly and firmly in this interior space against a ring edge of the ring (203), which passes through the ring opening (206) of the ring (203) with some clearance and projects into the area of the interior space (202) on the tank side, where it engages in a through-hole (217) of the armature cylinder (210).
43. Oil burner according to Claim 42,
    characterized in that
    the piston (205) is penetrated by a through-hole (207) which is wider at the end of the piston nearest the tank and there accommodates a non-return valve (208), which for its closed position is pressed by a helical spring (209) in the direction towards the tank and against a valve seat (209a).
44. Oil burner according to Claim 42 and/or Claim 43,
    characterized in that
    the pump cylinder (210) of the reciprocating piston pump rests form-closingly and can slide against the part of the piston (205) located within and on the tank side of the interior space (202), the said cylinder being pushed by a helical spring (211) one end of which rests against the ring (203) while the other end rests against a ring step (212) of the cylinder (210) so that its front flange surface (214) on the tank side is pushed against a ring step (213) within the interior space (202), such that a valve stem (215) projecting beyond the front flange surface (214) extends with radial clearance a short way into the interior space (202) which is radially narrower in this area, and such that the front flange face of the cylinder (210) on the pressure-line side is positioned at a distance from the ring (203) so that there is room for the cylinder (210) to move.
45. Oil burner according to Claim 44,
    characterized in that
    the cylinder (210) guided form-closingly against the inner wall of the interior space (202) comprises around its surface longitudinal grooves (216) parallel to its axis and open at the front, and the through-hole (217) passing through the pump cylinder (210) and accommodating the piston (205) houses on the tank side a tappet valve before the piston (205), whose tappet head is positioned a distance away from the front flange surface of the piston (205) in a short section where the hole is enlarged, and whose tappet rod (219) passes through the narrowed hole (217a) in the valve stem (215) - resting against the inner wall of the hole (217a) - and projects into the narrower interior space (202a).
46. Oil burner according to Claim 45,
    characterized in that
    at the free end of the tappet rod (219) a disc is attached, which has holes (221), and the tappet rod (219) projects a short way beyond the disc (220), and contacts the tank-side bottom surface (222) of the interior space (202a), the length of the tappet rod (219) being chosen such that the tappet disc (218) is lifted clear of its valve seat (223) in the narrower hole (217a), forming a certain gap "X".
47. Oil burner according to Claim 46,
    characterized in that
    a helical spring (224) stabilizes the position of the tappet valve in the rest position of the reciprocating piston pump, inasmuch as the spring (224) rests at one end against the front flange surface (214) of the cylinder (210) and at the other end against the disc (220).
48. Oil burner according to one or more of Claims 42 to 47,
    characterized in that
    from the bottom surface (222) axially parallel holes extend into the bottom wall and open into an axial valve space (226), in which a valve disc (229) pressed by a helical spring (228) in the tank direction against a valve seat (227) is arranged, the said disc having peripheral grooves (230) that can be covered by the valve seat, so that the valve can be opened by pressure on the tank connection side against the force of the spring (228) and a passage is opened from the valve space (226) to the holes (225).
49. Oil burner according to Claim 42,
    characterized in that
    the piston (205) is formed in one piece with the front wall (200d) of the housing (200), such that the static pressure valve (208, 209) on the pressure-line side is positioned in a pipe section before the piston (205) and covers the mouth on the pressure-line side of the hole (207) passing through the piston (205).
50. Oil burner according to Claim 49,
    characterized in that
    the tappet rod is relatively short and can only project beyond the tank-side front flange surface (214) of the cylinder (210) by an amount equal to the valve clearance.
51. Oil burner according to Claim 50,
    characterized in that
    in the area of the front wall (200c) the front flange surface (214) makes contact with a plastic block (231) fixed there, the said block having through-holes (232) which open peripherally into grooves (233) which communicate with the interior space (202) on the tank side, such that from the tank-side interior space (202) holes (234) lead to the widened hole section of the hole (217) in the cylinder (210), and such that the holes (232) open into the axial valve space (226) leading to the tank, which is located in a pipe section (226a).
52. Oil burner according to Claim 51,
    characterized in that
    the wider part of the hole (217) in which the tappet disc (218) is accommodated, forms on the pressure-line side an annular step (235) which, in the rest position of the tappet valve, is only a small distance in front of the tappet disc (218) and makes contact against the disc (218) when, by inertia, the tappet is lifted off the valve seat during the return movement of the cylinder and/or the valve rebounds off the plastic block (231) during the return movement of the cylinder (210).
53. Oil burner according to Claim 52,
    characterized in that
    recesses (235a) are formed in the front surface of the ring step (235), which ensure unimpeded through-flow of the fuel.
54. Oil burner according to one or more of Claims 51 to 53,
    characterized in that
    the front flange surface (214) is positioned a small distance away from the surface of the plastic block (231).
55. Oil burner according to Claim 54,
    characterized in that
    projecting support webs (214a) are arranged on the front flange surface (214).
56. Oil burner according to one or more of Claims 42 to 55,
    characterized in that
    it comprises an armature-damping device in the free end area of the tappet stem (219), such that a flange ring (219a) is positioned there which spans some way from the side across the front flange surface (214) and may rest against the front flange surface (214), and such that in the surface of the plastic block (231) there is a recess (231a) corresponding to the flange ring (219a), into which the flange ring (219a) fits somewhat form-closingly.
57. Oil burner according to Claim 56,
    characterized in that
    the thickness of the flange ring (219a) is a little larger than the depth of the recess (231a).
58. Oil burner according to one or more of Claims 42 to 57,
    characterized in that
    a hole (234) is positioned in the front face (200d) on the pressure-line side, which leads from the interior space (202) on the pressure-line side outwards and over which, preferably on the outside, a connection piece (237) with a through-hole (238) is placed, such that through the hole (236) and the discharge pipe (237) fuel can be pumped away from the armature-cylinder (210) during the start-up phase of the pump (1) or the oil burner, or while they are running.
59. Oil burner according to one or more of Claims 41 to 58,
    characterized in that
    on the inner wall of the interior space (202) on the pressure-line side, a compression spring (238a) is positioned resting against the front wall (200b), against which a front flange surface (239) of the armature cylinder is pressed when the armature cylinder (210) accelerates, so that the said spring is compressed.
60. Oil burner according to one or more of Claims 42 to 59,
    characterized in that
    the cylinder (210) is guided as a piston-like armature element in the interior space (202) in a fluid-tight way.
61. Oil burner according to Claim 60,
    characterized in that
    a piston (205a) located partially within the armature cylinder bore (217) can move axially and forms part of the injection valve device (3).
62. Oil burner according to Claim 61,
    characterized in that
    the injection valve device (3) comprises a valve cap (3b) which is screwed firmly into the front wall (200d) of the housing (200) in the interior space (202) on the injection valve side, the piston (205a) in its rest position covers the injection nozzle hole (3d) with a front surface (205b) of reduced diameter, and the surface (205b) of reduced diameter develops via a conical frustum (205c) into the cylindrical part of the piston (205a).
63. Oil burner according to Claim 62.
    characterized in that
    the piston (205a) in the armature cylinder bore (217) is pushed by a compression spring (240) against the injection nozzle hole (3d), with the other end of the compression spring (240) resting against a partition (241) in the armature cylinder bore (217) which divides the bore (217) into a section on the injection nozzle side and a section on the tank side.
64. Oil burner according to Claim 63,
    characterized in that
    at least one hole (242) leads from the front flange surface (212) through the armature cylinder (210) into the wider cylinder bore space of the area of the bore (217) on the tank side, in which the tappet disc (218) is accommodated, and a hole (243) passes through the armature cylinder (210) from the injection nozzle side area of the bore (217) to the interior space (202) on the tank side, with the central portion of the armature cylinder (210) resting form-closingly and with an almost fluid-tight fit against the inner wall of the interior space (202).
65. Oil burner according to Claim 64,
    characterized in that
    the armature cylinder (210) has grooves in the area on the tank side of the interior space (202), whose salients are in contact with the inner wall of the space (202) where they act as guides for the armature cylinder (210).
66. Oil burner according to one or more of Claims 42 to 60,
    characterized in that
    the injection nozzle (3) is fitted directly in the front wall (200d) of the housing (200) and comprises a valve cap (3b) with a valve seat (3c) for a tappet valve (244), whose valve disc (245) is held from outside against the valve seat (3c) and whose tappet rod (246) passes through the cap hole behind the valve seat (3c) freely or radially supported by ribs (247) and passes freely through the armature cylinder bore (217), ending a short way before the wider portion of the bore (217) in which the tappet disc (218) of the tappet valve (218, 219) is accommodated, and to the free end of the tappet rod (246) is attached a ring (248a) with holes or radial recesses (248), against which a compression spring (250) rests on the injection valve side, the other end of which rests against the end wall (200d) of the housing (200) or against the valve cap (3b), such that the armature cylinder (210) has only its through-hole (217a) and no radial grooves, but rather, rests form-closingly and with a fluid-tight fit against the inner wall of the interior space (202), and such that the tappet disc (218) comes into contact with the tappet rod (246) after a certain stroke path during the movement of the pump.
67. Oil burner according to Claim 66,
    characterized in that
    the tappet rod (246) of the tappet valve (244) is made shorter and, in the resting position of the pump (1), reaches only as far as the end area of the armature cylinder bore (217) on the injection valve side, and in addition another compression spring (251) presses from the tank side against the ring (248a), the said spring at its other end resting against a wall (217e) with a central hole (217d) which divides the bore (217) into a section on the injection valve side and a section on the tank side, the two sections being in communication via the hole (217d).
68. Oil burner according to any of Claims I to 67,
    characterized in that
    a device for retarding the fuel flow is provided, whose activation converts the kinetic energy of the accelerated fuel abruptly into a shock-wave which ejects the fuel via the injection nozzle.
69. Oil burner according to Claim 68,
    characterized in that
    a common electronic control device (608) is provided for the pump (602) and the electrically activated retarding device (606).

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