DE2511324A1 - Pulsating fuel injector for diesel engines - has pressure applied to injector plunger via pneumatic connection to engine - Google Patents

Abstract

A free piston divides a cylinder into two parts, one working as a normal compression ignition engine with a direct injection system actuated by compressed air. The second chamber is filled with air which acts as a return spring to the piston. The injector pump consists of a pneumatic plunger regulated by the lower part of the piston provided with an inner chamber between the recessed outlet walls of the piston and the cylinder. The length of the recess is the same as the difference between the largest and smallest piston stroke. When the piston reaches b.d.c. compressed air enters the inner piston chamber and is able to move the pump plunger when the inner piston chamber outlet aligns with the plunger communication passage.

Description

Auguste Moiroux Ecully (Rhone), France Francois Bernard Lyon 3e (Rhone), France Intermittent fuel injection device, in particular for machines with direct action The invention relates to a fuel injection device, especially for a direct-acting machine that has at least one injection pump with a plunger which is controlled by a pneumatic lifting device, and which supplies a classic injection device.

It is known that such a machine is essentially a piston which slides in a cylinder, the piston in two opposite Divided chambers.

One of these chambers works like a classic combustion chamber Diesel engine with two strokes, while the other is filled with an air cushion. The combustion gas pushes the piston back against the air cushion until the piston reaches the inlet and exhaust ports. At that moment the squeezed bumps Air cushion backs the piston against the combustion chamber, etc. So the piston closes one Alternating movement between the combustion chamber and the air cushion is stimulated.

It is understandable that burst injection systems such as which are used in classic engines5 are not suitable for use with a Machine to be connected with direct effect. Indeed, these are well known Systems have the disadvantage that they have to be controlled by cams that are mechanical are connected to the engine piston. Now the piston is a machine with direct Effect completely independent and shows no mechanical connection to the outside on. The known injection systems are definitely suitable for such a machine not to use.

It is the object of the present invention to avoid these disadvantages, by making a device for intermittent injection available, at which for the control has no mechanical connection with the piston of the direct-acting Machine is necessary.

The object is achieved in that the piston of the direct acting machine without any intermediate movement between a compressed air chamber and the chamber for the pneumatic lifting device of the pump in a selected one Can establish a connection at the time of piston travel.

According to a further feature of the invention, the connection between the compressed air chamber and the lifter chamber by the piston itself manufactured.

In this case, the piston has an inner chamber that has a outer annular chamber is fed, which is separated by sealing rings. At either end of a working stroke is this annular chamber in connection with the Air cushion and lets compressed air under the maximum pressure of the cushion into the annular chamber a. Then this amount of air is let into the inner chamber through the piston, until the outer ring chamber at the appropriate time with the chamber for the pneumatic Lifting device is connected via a line ending in the jacket. In the The compressed air present in the inner chamber then controls the injection. If the Piston moved back in the opposite direction, becomes the chamber for the pump lifting device discharged through an outlet recessed in the jacket or in the flask.

The system is designed in such a way that all feeding processes for the Inner chamber for all working stroke of the piston are possible.

According to a further feature of the invention, the connection between the compressed air chamber and the lifting device. ntation chamber via a piston rod produced, which forms a slide attached to the main piston, the piston rod has a small piston at the free end that provides the compressed air required for work generated.

According to a further property of the invention, the control lifting device the injection pump and the plunger of this pump coaxially in their mutual Extension arranged with the reciprocating piston directly onto the end of the plunger acts, while two elastic stops are each provided at the ends of the chamber in which the reciprocating piston slides and where it is the task of the stops, dampen and stop the movement of the reciprocating piston.

A return spring is on the top of the lift chamber and on one at the end of the plunger provided shoulder supported, it being the task of this The spring is to return the reciprocating piston to the bottom of the chamber.

According to a further feature of the invention, there is one in one pass provided check valve, which opens into the air cushion chamber, the passage of air into this chamber, and so is the air necessary for injection fed.

According to a further property of the invention is a rack, which controls the angular position of a ramp in a known way, which is at the end of the plunger is, firmly connected to a piston or a membrane that a cylinder for regulation separates into two chambers, one of which is a return spring takes up which the rack can push back in one sense, while the other Chamber air at the same pressure as that on the direct-acting machine Air, which is supplied by the compressor, absorbs and so the rack in the other Can repel senses.

According to a further property of the invention, the ramp has the Injection pump has a first part that allows the fuel slot from enlarge the smallest slot to the largest slot and a second part, which follows the first part that allows the fuel slot to be removed from his Reduce the maximum size to the minimum size, with the ramp in the sense of a Increase in the control pressure acting on the piston is aligned.

In this way there is an automatic regulation of the mode of operation of the direct-acting machine as a function of the pressure accumulated by the compressor Air reached. In fact, as long as the pressure is the air trapped by the compressor does not reach the compensation value for the return spring that caused the displacement the piston or the diaphragm that controls the rack acts, the fuel slot at a minimum. When the pressure of the trapped air exceeds the compensation value for the return spring reached, the rack is moved so that the slot on his Maximum value increased, which is also the minimum value of the working pressure of the pent-up Compressed air corresponds. If this pressure tends to increase, the Rack always moved in the same direction, with the fuel slot again reduced to its minimum value, whereby it is the direct acting machine, which drives the compressor, is allowed to stabilize and not compressed air more to deliver.

According to a further characteristic of the invention are devices provided that make it possible to absorb the air trapped by the compressor Control cylinder to introduce air under high pressure in such a way that the slot is at zero is brought and the machine is stopped as soon as one of the active safety devices the machine disengages and detects a lubrication failure, for example.

According to a further feature of the invention is a hand push button fixed to the piston controlling the rotation of the plunger or to the diaphragm tied together. This button allows manual interruption of machine operation.

According to a further property of the invention, the fuel injection device downstream or below the injection needle, an emptying line on, over which the system can be effectively and completely drained.

According to a further property of the invention, the fuel feed system an independent reservoir that is used to feed the injection pump and the with the help of jammed and compressed by the direct-acting machine Air is kept under pressure. The reservoir also takes what is at the Emptying of the injection pump occurs.

According to a further property of the invention, the fuel feed circuit has a fixed memory for the starting pressure of the machine - during this Maintaining the starting pressure, the trapped air can penetrate into the reservoir, in order to apply the pressure force necessary to feed the injection pump.

According to a further feature of the invention, the compressed Air, which exerts the compressive force in the reservoir, into a tight vessel inside it Reservoirs, while the expansion of the vessel is limited by a grid can be that the feed pressure is lowered and the machine is stopped before the fuel circuit or the reservoir is completely emptied.

Further features and advantages of the invention emerge from the following Description of the exemplary embodiments shown schematically in the accompanying drawings. 1 shows a sectional view of a direct-acting machine which is equipped with a Device for intermittent injection is provided, according to the invention directly is controlled by a piston, Fig. 2 is a detailed view of the injector of this device, Fig. 3 is a sectional view of a direct acting machine which is provided with a device for intermittent injection by an auxiliary piston is controlled, 4 shows an overall view of the fuel feed circuit and FIGS. 5 and 6 are views of the working ramps of the injection pump.

In Fig. 1 is the extreme capacities of a direct acting motor compressor shown. This machine consists essentially of a piston 1 in a Cylinder 2 slides, which the piston divides into two chambers 3 and h.

The chamber 3 works like a normal diesel engine chamber.

It has an injection device 5 in a known manner.

In contrast, the chamber 4 is filled with an air cushion that as Return spring works. The piston 1 thus becomes a reciprocating movement stimulated between chambers 3 and 4. With the help of devices not shown it can be used as a classic group motor compressor Lut; compress.

The injection device 5 is with the help of an injection pump 6, which is connected to the cylinder 2 is supplied with fuel. This pump has a pneumatic lifting device, which consists of a piston 7, which is in a chamber 8 moves. This lifting device can have a plunger 9 with the push back that touching end. The angular position of the plunger 9 is determined with the aid of a rack 10.

In particular, the invention relates to the action of the lifting device 7 in the chamber 8 with compressed gas.

For this purpose, the piston 1 of the direct-acting machine is in the vicinity of the end that is in contact with the air cushion in the chamber 4, one Inner chamber 11. One Opening 12 represents the for this chamber Connection with an annular chamber 13, on the one hand from the inner wall of the cylinder 2 and on the other hand by an annular recess in the outer wall of the end of the piston 1 is limited.

This annular chamber 13 has a length 15 in the axial direction. These Length is at least equal to the difference between the smallest and largest working stroke of the piston 1, which has the smallest and largest grooves or piston running surfaces of the direct-acting Machine corresponds.

When the piston 1 is in accordance with the pressure of the air cushion 4 in Dead center is, the inner chamber 11 can be via an annular channel 16 from the Fill chamber 4 filled with compressed air with air, the annular channel 16 connects the bottom of the chamber 4 with openings 17 machined in the cylinder 2. These openings 17 are in the same transverse plane that of the bottom of the Chamber 4 forming the end wall is located at a distance 18. This distance is at least equal to the distance of the edge of the annular chamber closest to the chamber 4 13 from this end wall when the piston 1 is at the dead center, the compression of the air cushion in chamber 4 of the minimum load of the direct-acting machine is equivalent to. Thanks to this arrangement it is ensured that the chamber 11 is always again fills with compressed air from the air cushion of the chamber 4.

So that in the chamber 4 with the air cushion removed from the piston 1 Amount of air can get back in, is located in the bottom of the chamber 4 after externally opening passage 19 which is provided with a check valve 20.

Air can enter the chamber 4 through this valve 20.

The chamber 8 of the lifting device for the injection pump is with the Inside the cylinder 2 via a passage opening 21 in connection, which opens into the cylinder 2 at a distance 22 from the bottom of the chamber 4. This The distance is greater than the length 15 of the annular chamber 13.

The reciprocating piston 7 slides in a chamber 23, both ends of which are provided with an elastic stop 24, which the movement of the piston 7 dampens and stops.

A return spring 25 pushes the plunger 9 and the piston 7 over a shoulder 26 constantly back towards the end of the chamber 8 where the passage opening 21 opens into cylinder 2.

The reciprocating piston 7 and the plunger 9 are in their mutual Extension arranged and work in the same housing, which is subsequently the pump housing 6 is called. The angular position of the plunger 9 is determined by the rack 10 controlled, which is extended by a shaft 126. This shaft is solid with a rule (adjusting) piston 27 connected, which slides in a cylinder 28, the is in turn firmly connected to the pump housing 6. The piston 27 separates chambers 29 and 30 of each other. In the chamber 30 there is a spring that the piston 27 pushes back towards the outer end of the cylinder 28, this movement reducing the size of the fuel slot determined by the ramp 31 of the plunger 9. The chamber 29 takes the accumulated from the compressor via devices not shown Air according to an arrow 32 via an opening 33. It can also have an opening 34 air under high pressure from a compressor by means not shown 35 can be inserted into the chamber 29 when one of the active safety devices the direct-acting machine breaks down, such as a failure of the lubrication, notices.

The shaft 126 protrudes beyond the cylinder 28 and ends in one Button 36 which can be acted upon by hand.

The injection device 5 opens into the combustion chamber 3 a needle 37 in a known manner. Downstream or

a conduit 38 is let in below the needle for drainage of the whole injection system.

The injection pump is via an opening 39 made in the wall of the Pump housing 6 is let in, supplied with fuel, while a non-return valve 40 enables the injection device 5 to be fed via a pipe system 41.

In FIG. 3, the external capacitances are as shown in FIG. 1 direct-acting machine shown. In this case, however, the piston 1 carries a piston rod 42, on the recesses 43 are incorporated, the forwarding allow air along the piston rod 42. The piston rod ends in one another piston 45.

This unit slides in a housing 46 and thus delimits a chamber 47, which is fed via a suction flap 48.

In the housing 46 a groove 49 is incorporated through which the Chamber 8 of the lifting device 7 is fed through the opening 21, while a Groove 44 can be emptied to the outside. The intake valve 48 can with atmospheric Air or compressed air can be fed from the machine via a line 80.

The fuel feed circuit is shown in FIG. He knows a reservoir 50 which is connected to the injection pump 6 via a line 51 is. Before the fuel enters this line, it passes a filter 52.

The outflows from the injection device 5 return via a line 53 back into the reservoir.

An expandable and tight container 54 is arranged in the reservoir. Compressed material accumulated by the machine is accumulated in this container via a line 55 Air introduced.

The expansion of the container is limited by a grid 56, the is arranged at a small distance above the bottom of the reservoir 50. The reservoir is closed by a lid 156 which has a locking notch for removal to be avoided if there is pressure inside the reservoir.

The injection pump can be started via a small storage chamber 57 of the group motor compressor are fed in such a way that it leaves the latter time, to let the pressure in the feed reservoir 50 rise. This chamber 57 is through a Diaphragm 60 divided into two areas 58 and 59. The membrane 60 is through a Spring 61 constantly pushed back in the direction of area 59. The area 58 becomes Filled with fuel via a line 62 which opens into the line 51. the Line 51 connects the reservoir 50 with the injection pump 6. The area 59 is at a standstill via a line 63 under the starting pressure of the group motor compressor.

A check valve 64 is arranged in line 51.

In FIGS. 5 and 6, two extreme forms are indicated according to which the injection ramp 31 of the plunger 9 can be designed. In these figures is the development of the cylindrical surface of the plunger end that supports the ramp 31 has shown. The ramp shown in Fig. 5 is at the beginning before Injection constant and growing at the fuel slot and then decreasing Like previously described.

The ramp shown in FIG. 6 is constant at the end of the injection and getting bigger and then smaller at the fuel slot.

Of course, the final shape to be adopted for the ramp 31 must be located between the two extreme cases of the figures.

The injection pump 6 functions in the following way: In Fig. 1 is the plunger 9 pushed back completely downwards in the rest position. The opening the line 39, via which the fuel is fed into the pump, is released from the ramp 31 so that fuel is introduced into the injection pump will. The pump is then ready to inject fuel into the injection device 5.

Thus, the piston 1 of the direct-acting machine is through the front resulting from the previous combustion and located in chamber 3 Gas pushed back against the air cushion created in the chamber 4. The piston 1 follows its path to its dead center according to the compression of the Air cushion. The inner chamber 11 of the piston 1 fills with compressed air, the air cushion passes through the openings 17. The air cushion then pokes the piston 1 back to the combustion chamber 3. When the chamber 13 in connection with the Passage opening 21 passes, the compressed air contained in the inner chamber 11 penetrates Air into the lifting chamber 8 for the control of the injection pump 6. The piston 7 is consequently pushed upwards and takes the plunger 9 with it. The injector 5 is supplied with fuel via line 41. So it takes place in chamber 3 a new combustion takes place, and the piston 1 is against that contained in the chamber 4 Air cushion pushed back. The plunger 9 is in turn supported by the spring 25 pushed back down into its original position. The arrangement is then for ready for a new cycle.

In the case of Fig. 3, the flap 48 opens when the piston 1 from Combustion gas is repelled against the air cushion, and lets into the cylinder 47 Air flow in.

The injection piston is then located in the lower one by the spring 25 repulsed position. When the piston 1 is pushed back by the air cushion is, the piston 45 compresses the air in the cylinder 47. At that for the injection At the selected point, the recesses 43 come under the feed recess 49, the lifting chamber 8, and the air compressed in the receiving chamber 47 passes under the lifting device 7, which can move the metering (plunger) piston 9 quickly and the injection caused by fuel.

The recesses 43 then leave the chamber 47 and separate the chamber 8 from. Then they allow their discharge to the outside through the groove 44 established connection, whereby the lifting device 7 and the dosing (plunger) piston Lower 9 again. The piston 1 then returns under the effect of the combustion back to the air cushion.

The flats 43 stop the discharge and then set again the connection between the capacitance or chamber 47 and the capacitance or chamber 8 ago. The chamber 47 is no longer filled sufficiently to prevent the piston from rising and to operate lifting devices 9 - 7, which therefore remain down. Then leave the flats 43 the connection zone with the groove 49. The pressure falls in the chamber 47 and the flap 48 opens, whereby the cycle begins again.

The angular position of the plunger 9 determines the ramp 31 Amount of fuel injected. At the beginning, the spring 30 pushes the rack 10 to the right, creating a minimal fuel slot. The direct acting The machine works with this fuel slot as long as the one from the compressor accumulated air introduced into the chamber 29 through the opening 33 on the piston 27 applied force under the balancing force of the spring 30 remains. If against it the pressure of the compressed air accumulated by the compressor is the equalization pressure the spring 30 exceeds, the rack 10 is pushed back to the left, so that the fuel slot increases. The compensation pressure of the spring 30 can be for example 5 bar.

The ramp 31 enlarges the fuel slot until it is at its maximum value achieved. This maximum value of the fuel slot corresponds to that of the compressor accumulated air pressure of about 6 bar, this value being the minimum working pressure of the compressor. Starting from this point and for example from 6 to 8 bar, the fuel slot is brought back to its minimum value. The direct acting The machine stabilizes at approximately this point and no longer accumulates air. As soon as the compressor uses backed-up air, the pressure in the chamber drops 29, so that the slot is enlarged and the machine is on the demanded Power to a pressure between 6 and 8 bar. When the exploitation or withdrawal exceeds the capacity of the machine, the pressure falls below 6 bar, and the machine is brought back to the starting slot, i.e. in the safety position. If, on the other hand, the back pressure exceeds 8 bar for any reason, the Ramp in the stop position and stop the machine.

To stop the machine, the operator presses the button 36. This actuation has the consequence that the ramp is brought into the area where the fuel slot is zero.

In the event that the safety device is activated, For example, if there is insufficient lubrication, the one coming from the machine will be under high pressure air admitted into the chamber 29, whereby the rack 10 is pushed back, and the engine is stopped by opening the fuel slot is brought to zero immediately.

The trigger point for the operation of the injection pump 6 is fixed, however, the injection point can be adjusted if a ramp with automatic Advance (auto-avance), as shown in Fig. 6, is used.

The fuel-feed circuit works as follows: This cycle is shown in FIG. During operation, the machine is introduced into the expandable container 54 of trapped air. The one in reservoir 50 The fuel contained is therefore put under pressure. It is pushed into line 51 and passes through a check valve 64 before entering the injection pump 6. With each injection, the fuel is in the line 51 in the direction of the Injection device 5 pushed back. Thanks to this device becomes the injection pump 6 constantly supplied with fuel. This supply stops when the container 54 reaches the grid 56, which limits its extent. In fact it stands Fuel is no longer under pressure and can no longer be fed into the injection pump 6 penetrate.

The largest volume of the container 54 when in contact with the Grid 56 is smaller than the volume of the reservoir 50. So is the reservoir never completely emptied of fuel, thus avoiding the whole feed circuit ever runs out of fuel.

In the reservoir 50, the fuel is collected when emptying of the feed circuit comes from the line 53.

The container 54 prevents air from being in the fuel can solve.

When starting, fuel can be fed into the injection pump through chamber 57 6 will be introduced. Before starting, the spring 61 pushes the diaphragm 60 to the right. As soon as the operator starts the direct-acting machine, the line 63 Starting air introduced into the chamber 59. The fuel contained in chamber 58 is therefore pressurized so that the injection pump 6 is fed with fuel will. The check valve 64 prevents the pressurized Fuel from chamber 58 flows back into the reservoir.

Subsequently, the pressure in the container 54 increases so that it pressurizes the fuel contained in the reservoir 50 to such an extent that the fuel supply can take place via line 51. The membrane 60 then has a damping effect access to the injection pump.

The main advantage of the invention is that the injection pump can be controlled without a mechanical connection between this pump and the moving elements of the direct-acting machine would be necessary and that it it is possible to feed the fuel circuit without a pump.

Patent claims:

Claims (16)

P a t e n t a n s p r ü c h e: 1. fuel injector, especially for a direct-acting machine that has at least one injection pump with a plunger which is controlled by a pneumatic lifting device, and which supplies a classic injection device, which is not possible z e i c h n e t that a piston (1) of the direct-acting machine without intermediate movement a pressurized chamber (4) with a chamber (8) of the control lifting device (7) at the appropriate point of the piston stroke selected for fuel injection is, can connect. 2. Injection device according to claim 1, d a d u r c h g e k e n nz e i c h n e t that the connection between the air pressure chamber (4) and the Lifting chamber (8) can be produced by the piston (1) itself, for which purpose the piston (1) has an inner chamber (11) ', which is separated by seals outer annular chamber (13) is fed, with an expansion stroke at each end of the motor in the direction of the chamber (4) forming an air cushion, this annular chamber (13) is in connection with the chamber (4) and the inner chamber (i1) is compressed Air with the maximum pressure of the air cushion (4) is supplied and this air amount then through piston (i) during its compression stroke of the engine is brought into the inner chamber (11) and at the point selected for injection via a line (21) which opens into the cylinder wall, in connection with the chamber (8) the eubvorrichtung (7) is brought, with the compressed air from the inner chamber (acts on the lifting device (7) and thus causes the fuel injection and the backward movement of the piston (t) the lifting device (7) of the injection pump (6) emptied. 3. Injection device according to claim 1, d a d u r c h g e k e n It is noted that the connection between a pressurized chamber (47) and the chamber (8) of the lifting device (7) via a piston rod (42) takes place, which forms a slide connected to the piston (1) itself, wherein the piston rod carries a small piston (45) that carries the necessary Air for the operation of the lifting device (7) on the one selected for the injection Point supplies, the emptying of the lifting device (7) through the the slide forming piston rod (42) is guaranteed 4. Injection device according to claim 2, that is to replace the out of the chamber (4) the air required to control the injection a check valve (20) is provided, which is arranged in a line (19) which on the one hand after outside and on the other hand in the bottom of the air cushion chamber (4) opens, with only one through this check valve (20) the entry of atmospheric air into it Chamber is made possible. 5. Injection device according to claim 3, d a d u r c h g e k e n Note that the cylinder in which the air used for control compressed, fed at a pressure higher than atmospheric Pressure is and comes from the machine. 6. injection device according to one of the preceding claims, d a d u r c h e k e n n z. e i c h n e t that one controlling the injection opening The following two ramp (31) at the end of the plunger (9) of the injection pump (6) Has areas: - a first area in which the fuel slot can be enlarged from a minimum slot to a maximum slot, - one second area following the first and in which the fuel slot of one Maximum slot can be brought back to a minimum slot, with devices for rotating the plunger (9) are provided so that the ramp (31) the enlargement of the fuel slot from the minimum slot to the maximum slot with their first area controls to the extent that the pressure of the air accumulated by the compressor increases increased to the minimum working pressure, which then corresponds to the maximum slot, and that the ramp (31), if the pressure then increases, with its second area the reduction of the fuel slot from the maximum slot to the minimum slot controls at which the compressor no longer accumulates air, and this minimum slot then corresponds to the maximum working pressure. 7. Injection device according to one of the preceding claims, d u r c h e k e n n n z e i c h n e t that the fuel injector (5) a drain line (38) downstream or below the injection needle (37), this line (38) an effective and complete emptying of the Fuel cycle allows. 8. Injection device according to claim 6, d a d u r c h g e k e n It should be noted that the fuel feed circuit is an independent reservoir (50) for feeding the injection pump (6), which is operated with the aid of the machine pent-up compressed air is pressurized. °. Injection device according to claim 6, d u r c h e k e n It is not noted that the fuel feed circuit has a collecting device (57) exhibits, the one by a piston or a membrane (60) in two independent Areas (58, 59) represents subdivided chambers, this piston or these The membrane (60) is constantly pushed back into one of the areas (59) by suitable devices and where this area absorbs compressed air from a reserve at takeoff can in such a way that the fuel is under pressure via the piston or the membrane (60) can be set that is contained in the other area (58), the one line (51), which connects the injection pump (6) to the fuel reservoir (50) is and where a check valve j64) in this line (51) between the reservoir (50) and the collection chamber (57) is arranged in order to avoid that the under pressure Stagnant fuel flows back into the reservoir (50) instead of into the injection pump (6). 10. Injection device according to one of the preceding claims, d u r h e k e n n n z e i c h n e t that a com-piimed air which the im Reservoir (50) pressurized fuel contained in a sealed container (54) is inserted, which is located inside the reservoir (50), while a Grid (55), which is also arranged in the reservoir (50), the extent of the Container (54) can limit such that the feed pressure drops and the machine stopped before the fuel circuit is completely emptied. 11. Injection device according to one of the preceding claims, d a d u r c h e k e n n n z e i c h n e t that the lifting device (7) for the control the injection pump (6) and the plunger (9) of this pump coaxially are arranged in their extension on both sides, the piston of the lifting device (7) acts directly on the end of the plunger (9) while two deformable Stops (24) each at the ends of the chamber (23) in which the piston of the lifting device (7) slides, are arranged, these stops (24) the movement of the piston the lifting device (7), while finally a return spring (25), which is supported on a shoulder (26) provided at the end of the plunger (9), the piston of the lifting device (7) constantly to the end of the chamber (8) of this piston, into which the opening (21) opens, can be retrieved, this opening (21) the pneumatic lifting device (7) with the cylinder (2) of the direct-acting Machine connects. 12. Injection device according to claim 6, d a d u r c h g e k e n n z e i c h n e t that a rack (10), which in a known manner the angular position the ramp (31) at the end of the plunger (9) controls, with a piston or a Membrane (27) is firmly connected, which or which a cylinder (28) in two Chambers (29, 30) divided, one of which (30) receives a return spring, which the Rack (10) can move in the sense that a reduction in size of the injection slot while the other chamber (29) takes in air that has been trapped by the compressor, so that when the pressure of the air accumulated by the compressor rises, the rack (10) is moved automatically in the sense of enlarging the injection slot is equivalent to. 13. Injection device according to one of the preceding claims, d a d u r c h e k e n n n n z e i c h n e t that Facilities provided are, via which in the regulating chamber (29), which the accumulated by the compressor Taking in air, high pressure air is introduced from the compressor in such a way the slot can be zeroed and the machine stopped, as soon as one of the active safety devices on the machine disengages, for example detects a lack of lubrication. 14. Injection device according to one of claims 6 to 13, d a d u r c h e k e n n n n z e i c h n e t that at the end of the shaft (126), which the toothed rack (10) extended, a push button (36) is provided with which the machine can be operated by hand can be stopped. 15. Injection device according to one of claims 3 to 5, d a d It is indicated that the piston (45) has small dimensions slides axially in a cylinder (46), the internal volume of which is divided into two chambers, underneath there is an on-the-side its / free end and open to the outside atmosphere Outer chamber and an inner chamber (47) into which an air supply opening opens, which can be closed by a non-return valve (48) that only allows entry allows air into the inner chamber (47). 16. Injection device according to claim 15, d a d u r c h g e k e It is noted that the slide of the piston rod {42) has at least one flattening or recess (43) which connects on the one hand the inner chamber (47) and a first groove (49) in the longitudinal guide bore of the piston rod, this groove (49) with the chamber (8) der @ tung) for the control of the injection pump (6 rbi @ g stands and on the other hand between this e @@ recess (49) and a second recess (44, which represents the outside atmosphere is open and @ug to the inner chamber (47) on the opposite of the first A ment (49) Side of the cylinder wall is arranged.