EP0686763B1 - Fuel injection valve for internal combustion engines - Google Patents

Abstract

There is a longitudinally displaceable injection valve member (24) is provided for closing and opening the injection apertures (21). The injection valve member is activated in the opening direction with fuel pressure from a fuel high pressure feed conduit (32). A control device (3) controls the adjustment movement of the injection valve member and incorporates a longitudinally displaceable control piston (50), which on the one first side is activated by the fuel control pressure in a control chamber, which via at least one inlet aperture is connected with the fuel high pressure feed conduit (32).

Description

The invention relates to a fuel injection valve for intermittent fuel injection into the combustion chamber an internal combustion engine according to the preamble of Claim 1.

Injectors of this type are for example from the Patents EP 0 228 578 or EP 0 426 205 are known.

The invention as characterized in the claims solves the task of creating a fuel injector, that ensures improved operating behavior and also extremely easy to manufacture and assemble is.

The invention is described below with reference to the drawing The exemplary embodiments shown are described in more detail.

Fig.1

eine erste Ausbildungsform eines Brennstoffeinspritzventils im Längsschnitt;

Fig.2

im vergrössertem Massstab und im Längsschnitt eine der Fig.1 entsprechende erste Ausführungsform einer Steuervorrichtung des Brennstoffeinspritzventils;

Fig.3

eine zweite Ausführungsform der Steuervorrichtung;

Fig.4

eine dritte Ausführungsform der Steuervorrichtung;

Fig.5

eine vierte Ausführungsform der Steuervorrichtung;

Fig.6

im partiellen Längsschnitt eine zweite Ausbildungsform des Brennstoffeinspritzventils mit einer fünften Ausführungsform der Steuervorrichtung;

Fig.7

in vergrössertem Massstab einen Teil der Steuervorrichtung gemäss Fig.6;

Fig.8

eine sechste Ausführungsform der Steuervorrichtung für das Brennstoffeinspritzventil nach Fig.6;

Fig.9

eine siebte Ausführungsform der Steuervorrichtung für das Brennstoffeinspritzventil nach Fig.1;

Fig.10

eine achte Ausführungsform der Steuervorrichtung für das Brennstoffeinspritzventil nach Fig.1;

Fig.11

eine neunte Ausführungsform der Steuervorrichtung für das Brennstoffeinspritzventil nach Fig.6;

Fig.12

eine zehnte Ausführungsform der Steuervorrichtung für das Brennstoffeinspritzventil nach Fig.6.

Show it:

Fig. 1

a first embodiment of a fuel injector in longitudinal section;

Fig. 2

on an enlarged scale and in longitudinal section, a first embodiment of a control device of the fuel injector corresponding to FIG. 1;

Fig. 3

a second embodiment of the control device;

Fig. 4

a third embodiment of the control device;

Fig. 5

a fourth embodiment of the control device;

Fig. 6

in partial longitudinal section, a second embodiment of the fuel injector with a fifth embodiment of the control device;

Fig. 7

on an enlarged scale, part of the control device according to Figure 6;

Fig. 8

a sixth embodiment of the control device for the fuel injector according to Figure 6;

Fig. 9

a seventh embodiment of the control device for the fuel injector of Figure 1;

Fig. 10

an eighth embodiment of the control device for the fuel injector according to Figure 1;

Fig. 11

a ninth embodiment of the control device for the fuel injector according to Figure 6;

Fig. 12

a tenth embodiment of the control device for the fuel injector according to Figure 6.

In Fig.1 is a fuel injector 1 in one Position shown between two injection processes. The Fuel injector 1 is over a High-pressure fuel connection 10 and via a Fuel return connection 12 with a high-pressure delivery device for the fuel and over electrical Connections 14 connected to an electronic control. The high pressure conveyor and the electronic Controls are not shown in the drawing.

The housing of the fuel injection valve 1 is 15 designated. At the lower end is the housing 15 with a Union nut trained holding part 16, with at the upper end a corresponding retaining nut 17 screwed.

In the holding part 16, a nozzle body 18 is inserted, the Nozzle tip 19 protrudes from the holding part 16. The Nozzle tip 19 is provided with a nozzle needle seat 20 and has a plurality of injection openings 21 in this area. in the Nozzle body 18 is an injection valve member, axially adjustable nozzle needle 24 in one Needle guide bore 23 slidably. The Injection openings 21 of the nozzle tip 19 are through a lower end 25 of the nozzle needle 24 can be locked.

The housing 15 has a central guide bore 29 provided, in which a control device 3 for control the adjustment movement of the injection valve member or Nozzle needle 24 is arranged. The control device 3 is described in detail below with reference to FIG. 2.

The fuel is fed through the high pressure delivery device via the high-pressure fuel connection and a first short Fuel supply bore 31 in two in the housing 15 parallel to Guide bore 29 arranged high pressure supply lines 32.33 promoted. The upper high pressure supply line 33 leads to the control device 3. The lower high pressure supply line 32 is arranged obliquely in an intermediate plate 36 Connecting bore 35 to a nozzle body bore 26 connected in an annular space 27 in the nozzle body 18th flows. The fuel does not pass from the annular space 27 Passages shown in more detail to the nozzle needle seat 20 and the injection openings 21. In the area of the annular space 27 the nozzle needle 24 is provided with a shoulder 28.

The intermediate plate 36 is opposite the housing 15 via a Pin 37 (there could also be two pins 37) positioned and sealing between the housing 15 and the nozzle body 18 arranged. One in a central bore 38 of the Intermediate plate 36 protruding upper part 39 of the nozzle needle 24 is operatively connected to an intermediate needle element 40 which on the other hand via a connecting rod 44 with a Control piston 50 of the control device 3 is connected. Between one on a shoulder 45 of the housing 15 supporting spring washer 46 and the needle intermediate element 40 is a connecting rod 44 surrounding nozzle needle spring 47 arranged biased.

The control device 3 has one in the guide bore 29 control body 52 used in a stationary manner. The control piston 50 is with an upper, stepped in diameter Piston part 51 provided. As can be seen particularly in Fig. 2 is, the upper piston part 51 protrudes into one in the Guide bore 29 axially displaceable and tightly sliding arranged sleeve 64 into it. Also between the piston part 51 and the inner diameter of the sleeve 64 are narrow Sliding fits provided. Between a lower face 65 of the sleeve 64 and a piston shoulder surface 53 is one Spring 63 arranged. The sleeve 64 is supported with a narrow annular sealing surface 66 on a lower End face 55 of the control body 52, on the other hand by a lock nut 54 screwed to the housing 15 in the guide bore 29 is axially fixed.

In the lower area of the control body 52 is in the Housing 15 is an annular space 69, which has a transverse bore 68 the upper high pressure supply line 33 is connected. Of the Control body 52 has an annular space 69 corresponding Circumferential ring groove 67. The control body 52 is also included one opening into a first control room 70 Provided connecting bore 60, which via a Inlet throttle bore 58 with the circumferential ring groove 67 or with the annular space 69 and thus also with the high pressure supply line 33 is connected. The connection bore 60 narrows at the top into an outlet opening 59.

The first control space 70 is radial through the inner surface of FIG Sleeve 64, axially through the lower end face 55 of the Control body 52 and an upper end face 56 of the Piston part 51 limited.

Between the piston part 51 and the guide bore 29 there is an annular, underneath the sleeve 64, second control chamber 74, in which the spring 63 is also arranged is, and the via a connecting bore 75 to the High pressure supply line 33 is connected. In the The connecting bore 75 is an orifice 76 with a throttle 77 used.

The control body 52 is in the guide bore 29 of the Housing 15 installed in such a way that no significant leakage can take place. This will e.g. with a press fit or reached a tight sliding seat, but could also through other fuel-tight connections, for example realized using suitable sealing rings become.

The control device 3 also has an electromagnetic actuatable pilot valve 80, of which only in Fig.2 an armature 82 firmly connected to a pilot valve stem 81 can be seen. In the position shown in Fig.2 the exhaust throttle bore 59 via a flat valve seat 85 held in the closed position. As shown in Fig.1 can be seen in the currentless state Electromagnet 86 of the pilot valve stem 81 by the force a compression spring 87 down into the valve flat seat 85 closing position pressed. This force is through a Adjustment screw 88 adjustable in size. For Actuation of the pilot valve 80 or to raise the Pilot valve stem 81 from valve flat seat 85 receives one excitation coil 83 of the electromagnet assigned to armature 82 86 via the electrical connections 14 control pulses from the electronic control.

When lifting the pilot valve stem 81 from the Outlet opening 59 is in accordance with Fig.1 in a drain space 89 collected and via a drain hole 90 fed to the fuel return port 12, which together installed with the electromagnet 86 in the holding nut 17 is. A flow also flows into the discharge space 89 Relief bore 92 of leakage in a space 91st fuel accumulated below the control piston 50. Consequently part of the fuel becomes practically depressurized High-pressure conveyor returned. The room 91, the Relief bore 92, the drain chamber 89 and the Drain hole 90 form a so-called low-pressure part the fuel injector 1.

The following results from the structure described Mode of operation of fuel injector 1:

Before the injection process, the high pressure part of the Fuel injector 1, i.e. in the Fuel feed hole 31, in both High pressure supply lines 32.33, in the annular spaces 27.69 and the same high pressure or in both control rooms 70, 74 Injection pressure, which can be up to over 1000 bar.

As soon as a pulse of selected duration is given to the electromagnet 86, the Armature 82 attracted against the force of the spring 87, whereby the pilot valve 80 is opened. Thus the Outlet opening 59 of the control body 52 opened. The pressure in first control room 70 sinks. The nozzle needle 24 is by the prevailing in the annular space 27 and acting on the paragraph 28 Fuel pressure raised from the nozzle needle seat 20. The Injection ports 21 are released and the fuel is in a manner known per se in the combustion chamber Internal combustion engine injected.

When the nozzle needle 24 is raised, the needle intermediate element is also used 40 and the connecting rod 44 of the Control piston 50 moves upward. The volume of the second Control room 74 becomes smaller, the pressure in control room 74 increases under this pumping action. The sleeve 64 is still more in the sealing position with respect to the control body 52 pressed. Via the connection bore 75 and the throttle 77, which lead to the high pressure supply line 33, the Opening movement of the injection valve member or Nozzle needle 24 counteracting pressure in the second control chamber 74 defined in the desired, controlled manner. This will a desired, controlled opening of the injection valve reached.

The end of the injection process is known to be done as quickly as possible. Again electronically controlled the pilot valve 80 into its via the electromagnet 86 Brought to the closed position. Since the outlet opening 59 is closed again, increases in the first control room 70 Pressure on, and the control piston 50 is by the on the force acting on the upper end face 56 of the piston part 51 moved down. The volume of the second control room 74 the fuel pressure in the second control room is increased 74 falls. The sleeve 64 initially remains on the control body 52 pressed. At certain decrease in fuel pressure in the second control chamber 74, the sleeve 64 follows Piston movement; it should be noted that the spring 63 is relatively weakly biased, so that the pressure effect of the Spring 63 is negligible compared to Fuel pressure forces. Once the sleeve 64 with the Seals sealing surface 66 from the control body 52, arrives abruptly about this new fuel connection from Annulus 69 or from the high pressure supply line 33 in the first control chamber 70. The control piston 50 and also the Sleeve 64 are accelerated downward; about the Connecting rod 44 and the needle intermediate element 40 is the nozzle needle 24 into which the injection openings 21 closing position pressed. In this way the Fuel injector 1 according to the invention is a faster one Injection closing process realized.

As soon as the pressure in the second control chamber 74 via the throttle 77 and the connecting bore 75 again System fuel high pressure is adjusted, pushes the spring 63 the sleeve 64 with the sealing surface 66 in the first Control chamber 70 radially limiting position.

In a first, not shown in the drawing alternative variant to the control device 3 according to FIG. 2 either in the transverse bore 68 or in the upper one High-pressure supply line 33 designed as a throttle Narrowing applied, which causes a weak throttling and thereby the acceleration of the Control piston 50 dampens slightly. This will make the bounce Nozzle needle 24 on the nozzle needle seat 20 at the end of Closing process reduced. Will the mentioned narrowing in the upper high pressure supply line 33 is provided, so this either in the area below the throttle 77 or are above it. This first variant of Control device 3 is particularly preferred if (for design reasons) there is a risk that the Nozzle needle seat 20 due to an excessive impact Nozzle needle 24 could be damaged.

In a second one, neither in the drawing Alternative variant to the control device 3 shown the throttle 77 is formed large, or it is on the Throttle 77 is completely dispensed with, so that the connecting bore 75 directly connected to the upper high pressure supply line 33 is. Thus, in this variant, there is a second control room 74 always the system fuel high pressure, which as a result of Pumping action of the control piston 50 during the opening movement the nozzle needle 24 rises practically or not at all; while during the closing process, the pressure in the second control room drops 74 either. The sleeve 64 loses in this case not during the closing movement of the nozzle needle 24 Contact with the lower end face 55 of the control body 52, what by appropriate dimensioning of the spring 63rd is guaranteed. The advantage of this variant is one control surface reduced compared to known solutions, which is controlled by the two throttle bores 59 and 58 must become. Over that of the front surface 56 of the upper Piston part 51 corresponding control surface, the movement of the much larger control piston 50 controlled.

3, 4 and 5 show further embodiments the control device for the fuel injector shown and described in more detail below. The from Fig.1 and 2 known and equivalent parts are still with the same reference numerals.

In the embodiment shown in Figure 3 a Control device 4 is the sleeve 64 known from FIGS. 1 and 2 replaced by a sleeve 94. The sleeve 94 has on the circumference several axially arranged ribs 95, whose Outside diameter a precisely defined radial annular gap 93 forms opposite the guide bore 29. The ring groove 67 in Control body 52 and the annular space 69 in the housing 15 omitted. Above the top rib 95 opens into the Guide bore 29 that supplying the high pressure fuel Cross bore 68 into it. The sleeve is on the upper face 94 with a narrow, annular sealing surface 96. The sealing surface 96 has a plurality of radial circumferentially distributed Wells 97 of shallow depth (approx. 0.02 - 0.03 mm), through which the fuel throttled from the pilot hole 29 and consequently from the transverse bore 68 to the first control chamber 70 arrives and the inlet throttle bore 58 of the from Fig.2 replace known control device 3. The ribs 95 on the other hand, replace the one known from FIG second control room 74 and the high pressure supply line 33 built-in throttle 77. The ribs 95 have sharp edges on to a regardless of the toughness of the fuel to achieve turbulent flow. By arranging several Ribs 95 in a row, the fuel pressure gradually reduced or the flow rate reduced. Thereby the annular gap can be dimensioned more generously.

The position of the sealing surface 96 in relation to the outside or Inner diameter of sleeve 94 may be necessary Contact pressure can be selected. The same sealing surface 96 and / or the radial recesses 97 could also in the Sleeve 64 of Fig.2 can be used.

This embodiment of the control device 4 is technically simpler than that in Fig. 1 and 2 illustrated embodiment. Otherwise it works same as already described.

Similar to the control device 3 according to FIG Control device 4 according to Figure 3 corresponding to that described first and also the second alternative variant be trained. To implement the second variant, at which the second control room 74 is in direct communication with is in the high pressure zone, a wide annular gap 93 provided between the sleeve 94 and the guide bore 29 or the ribs 95 can be omitted entirely.

4 shows a further embodiment of the Control device shown and designated 5.

In a part 99 of enlarged diameter Guide bore 29 is a sleeve 98 guided closely sliding, the same as the sleeve 94 known from FIG. 3 with the Recesses 97 provided narrow sealing surface 96 Is provided. The spring 63 is between the lower End face 65 of sleeve 98 and a housing shoulder 100 biased.

Parallel to the guide bore 29 is in the housing 15 Housing bore 102 made in the one Ball check valve 103 is installed. A lower one Valve seat element 104 of the ball check valve 103 has a bore 105 on the holes 106, 107 with the second control room 74 is connected. One of the Ball 108 assigned to valve seat element 104 is moved over a second valve element 109 by the force of a spring 110 the valve seat member 104 is pressed. The ball check valve 103 is by means of a locking pin 111, over which also the spring preload can be selected in the Housing bore 102 axially fixed. The connection of the second Control room 74 with the high pressure zone is thus over Ball check valve 103 manufactured.

Increases in the second control chamber 74 when the Nozzle needle 24 and the control piston 50 the fuel pressure by the pumping action of the control piston 50 to a specific one Size, the ball 108 of the ball check valve 103 raised and the pressure suddenly reached the system high pressure adjusted, whereby the counteraction against the Opening movement of the nozzle needle 24 is suddenly canceled (The choke 77 according to FIG. 2 has a continuous one Pressure equalization causes.). By means of the control device 5 is the opening movement of the nozzle needle 24 in one phase smaller (before opening the ball check valve 103) and divided a phase with high opening speed. Such a course of the opening movement of the nozzle needle 24 causes a favorable engine combustion.

A quick closing movement is the same as for Control device 3 reached in which the sleeve 98 at Downward movement of the control piston 50 and when the Fuel pressure in the second control room 74 under one certain size the connection of the high pressure system to the first control room 70 releases.

5 shows a further alternative embodiment of the Control device shown and designated 6. Instead of of the ball check valve 103 known from FIG a bore seat valve 113 is installed in the housing bore 102. Of the Taper seat between a valve body 114 and the housing 15 is designated 115. The valve body 114 is with a Cross bore 116 and one perpendicular to cross bore 116 arranged throttle bore 117 provided. The second Control room 74 is through the bores 107, 106, the Throttle bore 117 and the transverse bore 116 with the High pressure region connected.

In this variant, the fuel pressure in the second Control chamber 74 when control piston 50 moves upward both gradually over with the cone seat valve 113 closed the throttle bore 117 are balanced, as well large overpressure suddenly by lifting the valve body 114 from the conical seat 115 to be adjusted to the system pressure. At low cone seat valve 113 does not respond.

Fig. 6 shows an alternative form of training in partial section of the fuel injector, designated 2 and a further control device 7 is equipped. From 1 to 5 already known, identical and parts with the same effect are again given the same reference numbers designated. Part of the control device 7 is for the better Understanding enlarged in Fig.7.

According to Figure 6, the fuel injector 2 has Housing 120 on that with a central guide bore 121st is provided for the control device 7. In the Guide bore 121 is a spool 122 closely sliding axially displaceable. The control piston points at the top 122 a piston part 123 with a reduced diameter. The corresponding sales area is designated 126. Goes down the control piston 122 in a connecting rod 124 over, over which he non-positively with that not shown in Fig.6 Injection valve member (nozzle needle) is connected. If necessary, even the connecting rod 124 could with the Injection valve member be integrally formed. At the transition a piston shoulder 129 is formed to the connecting rod 124.

In one between the connecting rod 124 and the Guide hole 121 existing room 125 opens directly into the relatively short, first fuel supply bore 31 from High-pressure fuel connection 10. The housing 120 itself has no more high pressure supply lines on the Designation shown in Fig.1 designated 32.33 were; there are also no further ring spaces or Cross bores made in the housing 120, which makes an extreme simple and technically advantageous housing 120 is realized.

The upper piston part 123 is on its upper face a recess 128 provided in the one in the control piston 122 made central connection bore 130 opens. The The connecting bore 130 is in the control piston 122 made cross bore 131 to the high-pressure fuel filled room 125 connected.

A control body 135 is stationary in the guide bore 121 used (pressed in, for example) by the already known lock nut 54 is axially fixed. Of the Control body 135 is on its lower end face with a Recess 136 equipped into which the upper piston part 123th protrudes tightly. In a stepped diameter Part 137 of the recess 136 has a spring 138 arranged in it, via which a valve seat washer 140 to the upper one, with 127 designated annular end face of the upper piston part 123 is pressed. The valve seat disk 140 has a central disc hole 141 on.

In the recess 128 of the control piston 122 is in the position shown the disc hole 141 under effect a spring 144 except for a throttle bore 142 final valve body 143 arranged.

The valve seat plate 140 and the plate hole 141 closing valve bodies 143 form a first flat valve seat 151. The end face 127 of the piston part 123 and the valve seat plate 140 form a second valve flat seat 152 (see Fig. 7).

Between an annular, lower end face 139 of the Control body 135 and the shoulder surface 126 of the control piston 122 there is a first control chamber 155 which passes radially through the upper piston part 123 on the one hand and the guide bore 121 is limited on the other hand. On the circumference of the upper part of the piston 123 an inlet throttle 133 is made, which in the Connecting bore 130 opens radially and a connection of the forms first control chamber 155 to the high-pressure fuel zone.

At least one is on the circumference of the control body 135 Connection groove 157 made the first control room 155 connects with a transverse bore 158 in the control body 135. A in the transverse bore 158 opening 159 of the Control body 135 is in the position shown by the Pilot valve stem 81 kept closed, making the first Control room 155 from the low pressure part of the Fuel injector 2 is separated.

A second control chamber 156 is in the recess 136 of the Control body 135 formed above the piston part 123 and through the two valve flat seats 151, 152 from the system or High-pressure fuel zone in the illustrated Starting position separated between two injection processes held.

The mode of operation of the fuel injection valve 2 or of the control device 7 is as follows:
When the pilot valve stem 81 is raised and electronically controlled in the same way as described above, the outlet opening 159 is opened. The fuel pressure in the first control room 155 drops. The control piston 122 is moved upward by the high fuel pressure acting on the piston shoulder 129 and prevailing in the space 125. The injection valve member opens the injection openings to the combustion chamber of the internal combustion engine in the manner already described. When the control piston 122 together with the valve seat disk 140 is raised, the volume of the second control chamber 156 is reduced, the pressure increases with this pumping action and counteracts the opening movement in the desired manner. This results in a slow opening process. As soon as the pressure in the second control chamber 156 reaches a certain level, the valve body 143 is pressed down against the system pressure prevailing in the recess 128 and the force of the spring 144 via the disk hole 141 and the first flat valve seat 151 is opened, as a result of which the opening process of the control piston 122 and consequently the injection valve member is accelerated.

Exhaust port 159 becomes through the pilot valve stem closed again, so the pressure in the first control room rises 155 again. The pressure in the second control room 156 is adjusted again to the system high pressure. The spring 144 presses the valve body 143 against the valve seat plate 140 which on the other hand is loaded by the force of the spring 138. Of the first valve flat seat 151 is closed. About the Sales surface 126, the control piston 122 is moved down. The volume of the second control chamber 156 is increased, the Pressure drops. As soon as the pressure in the second control room 156 is one falls below a certain value at which insufficient Pressure force exerted on the valve seat plate 140 from above the second valve flat seat 152 is opened. In at that moment a connection of the second Control room 156 with the high pressure fuel supply made, the fuel over the control piston 122 the end face 127 is additionally accelerated downwards. In in this way a quick closing of the Injector member performed.

The fuel injector 2 according to the invention brings in addition to the simplification of construction and assembly technology also has the advantage of minimal leakage occur. The one from the exhaust throttle bore 159 escaping fuel is in turn through the drain hole 90 fed to the fuel return port.

Would the control device 7 according to FIGS. 7 the valve body 143 with the throttle bore 142 and the Omit spring 144 and valve seat disk 140 directly with provided as a throttle disc hole 141, so would the operation of the control device 7 of those correspond to the control device 3 from FIG. That as Throttle-formed disc hole 141 would then become the throttle 77 corresponding to FIG. 2, which correspond to the second control space 156 (in Fig. 2 control room 74) connects to the high pressure zone.

With additional omission of the valve seat plate 140 and the Spring 138 would control device 7 of the second alternative variant to the control device 3 according to FIG. 2 (with large or missing throttle 77) correspond, since in this If the second control room 156 also directly with the High pressure zone would be connected.

Another alternative embodiment is shown in FIG Control device 8 shown for the Fuel injector 2 can be used. From Fig. 6 and 7 known parts are again the same Designated reference numbers.

That is slidable in the guide bore 121 of the housing 120 arranged control piston 122 has no in this case Diameter of the piston part, but it is with an upper end face 161 is completed. Between the Control piston 122 and the control body 135 is a Intermediate piston 162 arranged in the recess 136 of the Control body 135 protrudes closely sliding. A first annular control chamber 160 is radial through the Intermediate piston 162 and the guide bore 121, axially through the upper end face 161 of the control piston 122 and the lower end face 139 of the control body 135 limited. A second control chamber 165 is located in recess 136 above the intermediate piston 162 or above an upper one End face 163 of the intermediate piston 162.

The intermediate piston 162 is provided with a shoulder 166. A spring 167 surrounding the intermediate piston 162 is on the shoulder 166 on the one hand and on the lower end face 139 of the Control body 135 supported on the other. The intermediate piston 162 has a narrow, annular sealing surface 168 at the bottom that of the upper end face 161 of the control piston 122 assigned. The diameter of the sealing surface is 168 smaller than the diameter of the recess 136 or than that Diameter of the upper end face 163 of the intermediate piston 162.

The intermediate piston 162 is from the bottom with a central one Provide recess 170. Between the recess 170 and the second control chamber 165 is one in the intermediate piston Connection hole 174 made, the one in the recess arranged ball valve 171 is assigned. A valve spring 173 is in the recess 170 by means of a in a bore 180 of the intermediate piston 162 pressed or screwed securing element 172 biased. The Securing element 172 has a central connecting bore 182 over which the space of the recess 170 with the Connection bore arranged centrally in the control piston 122 130 and thus in connection with the high-pressure fuel zone stands. The intermediate piston 162 is also with a Throttle bore 175 provided, through which the second Control chamber 165 parallel to that via ball valve 171 lockable connecting hole 174 with the recess 170 and is thus connected to the high-pressure fuel zone.

The intermediate piston 162 has an inlet throttle 184, which the first control chamber 160 with the bore 180 and thus with connects the high pressure fuel zone.

It would be entirely possible to replace the inlet throttle 184 Sealing surface 168 of the intermediate piston 162 with several To provide circumferentially distributed radial depressions - similar to the case with the sleeve 94 according to FIG. 3 (see. wells 97) to an inlet throttle connection of the first control room 160 with the high-pressure fuel zone to manufacture.

The structure of the control device 8 has the following operation:
When the pilot valve stem 81 is raised, the pressure in the first control chamber 160 is reduced via the outlet opening 159, the transverse bore 158 and the connecting groove 157. The control piston 122 is moved upwards in the manner already described, the injection valve member opening the injection openings to the combustion chamber of the internal combustion engine. The intermediate piston 162 pressed against the end face 161 with the sealing surface 168 is also moved upward. Due to the pumping action of the intermediate piston 162, the pressure in the second control chamber 165 increases. At a certain excess pressure, the ball valve 171; thus the opening movement of the control piston 122 is accelerated.

Is the outlet opening 159 through the pilot valve stem 81 closed again, so the pressure in the first control room rises 160. The pressure in the second control room 165 is applied to the System high pressure adjusted. The ball valve 171 closes. With the increasing pressure in the first control room 160, the Control piston 122 and the intermediate piston 162 down emotional. The volume of the second control room 165 becomes bigger, the pressure drops. With a certain pressure drop is the contact pressure of the intermediate piston 162 against the End face 161 of the control piston 122 no longer guaranteed. The intermediate piston 162 or its sealing surface 168 separates from the spool 122 and the spool 122 is additionally by the on its end face 161st acting high pressure fuel (via the connecting hole 130 delivered) accelerated downwards. The Injector member is closed suddenly. in the Contrary to the control device 7 known from FIG here the entire piston surface - similar to the Control device 3 in Figure 2 - acted upon.

The control device 8 means an essential one constructive simplification. It is known that the narrow Fits of individual parts the exact concentricity, i.e. precise processing important. In this embodiment points none of the parts two such to be coordinated Sliding surfaces. The control piston 122 has an extreme here simple shape on. The assembly of individual parts of the Control device 8 in the fuel injection valve 2 is no problem. Furthermore, the essential ones are the function determining controls (the throttle bores 175 and 184 and the ball valve 171) in the intermediate piston 162 made or installed. This throttle bores 175,184 and the ball valve 171 can before assembling the Fuel injector 2 for their correct function being checked.

Would one in this control device 8, the ball valve 171st with valve spring 173, the device would correspond to the control device 2 known from FIG. 2; also the second control room 165 would then only be via the Throttle 175 (corresponding to throttle 77 according to FIG. 2) with the High pressure zone connected.

The control device 8 could also correspond to the described, not shown in the drawing second alternative variant to the control device 2 is formed be by the second control chamber 165 does not have the throttle 175, which together with the securing element 172, the Ball valve 171 and valve spring 173 would be eliminated, but via a large through hole in the intermediate piston 162 would be connected directly to the high pressure zone.

9 shows a further embodiment of a Control device 9 shown in its design and Operation essentially from the control device 8 Fig.8 corresponds, but for example for the Fuel injector 1 according to Fig.1 is suitable at which, in contrast to fuel injector 2 6 shows the high-pressure fuel supply to the control device of done above. Analogous to control device 8, the Control device 9 the above-mentioned manufacturing and advantages in terms of assembly.

In this variant, the guide bore 29 of the Valve housing 15 a with a lower end face 178 provided control body 177 arranged stationary. The Indian Guide bore 29 is axially displaceable control piston 50 provided with a central recess 176 above. One yourself the end face 178 of the control body 177 over a narrow, annular sealing surface 187 supporting intermediate piston 179 protrudes tightly into the recess 176 of the control piston 50 inside. The intermediate piston 179 corresponds essentially to that Intermediate piston 162 according to Figure 8, however, is opposite this arranged vertically reversed by 180 °. Because the inner Design of the intermediate piston 179 that of the Corresponds to intermediate piston 162, are the same Parts labeled with the same reference numbers (see recess 170, ball valve 171, securing element 172, Connection bores 174, 182, throttle 175, valve spring 170). A spring 183 surrounding the intermediate piston 179 is on the one hand on a shoulder 185 of the intermediate piston 179, on the other hand on an upper end face 186 of the control piston 50 supported. A first, annular control space 201 is radially through the intermediate piston 179 and the guide bore 29, axially through the upper end face 186 of the control piston 50 and the lower end face 178 of the control body 177 limited. The first control room 201 is analogous to that Control devices 7 and 8 according to Fig. 7 and 8 over at least one made on the circumference of the control body 177 Connection groove 157 and through the transverse bore 158 with the through the outlet valve 159 which can be closed off the pilot valve stem 81 connected. The transverse bore 158 is via a throttle 198 and via a passage 199 to the upper one High-pressure supply line 33 (see FIG. 1) leading transverse bore 68 connected.

A second control chamber 202 is located below the intermediate piston 179 formed in the recess 176 of the control piston 50. Of the second control room 202 is temporarily over the by the Ball valve 171 lockable connecting hole 174 and constantly on the throttle 175 as well as on the Connection bore 182 in the securing element 172 and over a passage 200 made in the control body 177 with the transverse bore 68 in connected to the high pressure zone Connection.

The operation of the control device 9 corresponds to that described mode of operation of the control device 8 according to Fig. 8 and is therefore not repeated. This control device too 9 could be omitted analogously to the control device 8 individual parts are alternatively formed, then the Control device 2 according to Figure 2 or the described second alternative variant of this control device 2 correspond.

10 shows a further embodiment of a Control device 11 shown, provided for the Fuel injector 1 according to Fig. 1. This form of training is particularly suitable for small fuel injectors, where there is no space for arranging valves and springs is available.

In the central guide bore 29 of the valve housing 15 a control body 205 is used in a fixed position (for example pressed) and by the here as a union nut trained lock nut 54 axially fixed. Of the Control body 205 has one with a reduced diameter Part 206 with which it fits into a central recess 207 of the axially displaceable in the guide bore 29 Control piston 50 protrudes. A first, ring-shaped Control room 211 is radial through part 206 of the Control body 205 and through the guide bore 29, axially through a shoulder surface 209 of the control body 205 and a upper end face 208 of the control piston 50 limited. Of the first control room 211 is again the same as in Control devices 7, 8 and 9 via at least one on the circumference of the control body 205 made connecting groove 157 and via the transverse bore 158 with that through the pilot valve stem 81 lockable outlet opening 159. The Cross bore 158 is the same as in control device 9 via the throttle 198 and via the passage 199 to the upper high pressure supply line 33 (see Fig.1) leading Cross bore 68 connected, which is arranged obliquely here, and the one radial recess 213 of the control body 205 assigned. The recess 213 is via a throttle 214 and a central bore 215 in the control body 205 with a connected second control room 212, which is below the Control body 205 in the central recess 207 of the Control piston 50 is located.

In this embodiment, the opening process takes place similar to the control device 2 of Figure 2 in a Step; the throttle 214 corresponds here to the throttle 77 Fig. 2. However, this variant takes place at Closing no additional acceleration instead of how this was the case with the control device 2. The Control device 11 is manufacturing and assembly technology simple and as already mentioned especially for small ones Suitable for fuel injectors.

11 shows another one for the fuel injector 2 applicable embodiment of a Control device 13. The one with the central one, to the High pressure zone connected connection bore 130 provided in the guide bore 121 of the valve housing 120 axially displaceable control piston 122 has a central top Recess 218 on. There is a first one in the guide bore 121 Control body part 220 arranged stationary (for example pressed in) and axially fixed by the lock nut 54. A second control body part 221 projects into the recess 218 and is arranged in the recess 218 by one Spring 222 on top of a lower end face 223 of the first Control body part 220 pressed.

The first control body part 220 has a bore 260 provided, which in one of the pilot valve stem 81 lockable outlet opening 259 tapers, and the over at least one made in the lower end face 223 radial groove 224 connected to a first control chamber 226 is. The groove 224 could also be in the end face of the second Control body part 221 may be formed. The first, annular control chamber 226 is radial through the Guide bore 121 and the second control body part 221, axially through the lower end face 223 of the first Control body part 220 and an upper end face 225 of the Spool 122 limited. A second, about that Connection bore 130 directly to the high pressure zone connected control room 227 is in the Recess 218 below the second control body part 221.

The second control body part 221 has a central one Provide hole 257, which is in a top Inlet throttle bore 258 tapers. About the Inlet throttle bore 258 is (similar to that over the Inlet throttle bore 58 according to FIG. 2) the first control chamber 226 connected to the high pressure zone. The spring 222 can possibly omitted since the one prevailing in the second control room 227 System high pressure for the constant pressing of the second Control body part 221 to the first control body part 220 worries.

The control device 13 corresponds in its mode of operation the mentioned, but not shown in the drawing second alternative variant to the control device 2 Fig. 2. This variant also prevails in the second Control room 227 constantly the system fuel high pressure by the pumping action of the control piston 122 practically remains unaffected. The opening and closing movement of the Control piston 122 and thus also the nozzle needle 24 is over the annular upper end face 225 of the control piston 122 by the control pressure prevailing in the first control chamber 226 controlled, this control pressure from the design and spatial arrangement of the inlet throttle bore 258 and Exhaust opening 259 is dependent.

The division of a single control body into two Control body parts 220.221 brings a particularly simple Manufacture and assembly of the control device 13 with itself.

Another embodiment of a control device 22 for the fuel injection valve 2 according to FIG. 6 is in FIG. 12 shown and described below. For those already known parts are again the same reference numerals used.

This form of training is similar to the control device 11 according to Fig. 10 especially for small ones Fuel injectors suitable where there is no space for Arranging valves and springs is present.

The first control chamber 155 of the control device 22 is the same as in the control device 7 according to Figures 6 and 7 radially through the guide bore 121 and the stepped in diameter Piston part 123, axially through a piston shoulder 126 and the lower end face 139 of the control body 135 limited. Of the Piston part 123 is here with an additional offset Part 190 provided. A second control room 195 is above of the piston part 123 in the recess 136 of the control body 135 formed. One in the offset part 190 radially Made throttle 191 connects the second control room 195 with the connecting bore 130 and thus with the High pressure fuel zone. The throttle 191 could also on the Longitudinal axis of the control piston 122 or the Fuel injector 2 (similar to that Throttle bores 197 and 159) are attached. in the Control body 135 is one in the second control chamber 195 opening, central bore 196 available, which over a Throttle 197 is connected to the transverse bore 158. The first Control room 155 is here in contrast to the control device 7 not connected to the high pressure system according to FIG. 7 (cf. Throttle bore 133 in Fig.7), but it receives over the Throttle 197, the transverse bore 158 and the connecting groove 157 Pressure from the second control room 195. The pressure in the two Control rooms 155, 195 or the pumping action of the control piston 122 hangs both when opening and when closing the design of the chokes 191, 197. The throttle 191 replaces the first valve flat seat 151 or the Throttle bore 142 according to Fig. 7. In this embodiment finds no additional acceleration during the closing process instead of. The form of training as well as assembly is extreme simple.

Claims (26)

1. Fuel injection valve for the intermittent injection of fuel into the combustion space of an internal combustion engine, having a housing (15; 120), having a valve seat element (19) provided with injection openings (21), having a longitudinally displaceable injection valve member mounted in the housing (15; 120) for closing or opening the injection openings (21), having a control device (3; 4; 5; 6; 7; 8; 9; 11; 13; 22) for controlling the displacement movement of the injection valve member, the control device (3; 4; 5; 6; 7; 8; 9; 11; 13; 22) having a control piston (50; 122) guided so as to be longitudinally displaceable in a guide hole (29; 121) and being connected to the injection valve member and being subjected on one side to the system fuel pressure from a high-pressure fuel supply conduit (32; 31) and on the other side to the fuel control pressure in a first control chamber (70; 155; 160; 201; 211; 226), the first control chamber (70; 155; 160; 201; 211; 226) being in connection with the high-pressure fuel supply conduit (31) by means of at least one inlet throttle (58; 97; 133; 184; 197; 198; 258), and the control pressure in the first control chamber (70; 155; 160; 201; 211; 226) being controllable by opening or closing at least one outlet opening (59; 159; 259), whereto the control device (3; 4; 5; 6; 7; 8; 9; 11; 13; 22) is provided with a controllable pilot valve (80), characterized in that the control device (3; 4; 5; 6; 7; 8; 9; 11; 13; 22) has a second control chamber (74; 156; 165; 195; 202; 212; 227) which is connected continuously or at times to the high-pressure supply conduit (31), whose volume is changed by the displacement movement of the control piston (50; 122), whereby the pressure in the second control chamber (74; 156; 165; 195; 202; 212; 227) acts in opposition to the opening movement of the injection valve member and respectively of the control piston (50; 122).
2. Fuel injection valve according to Claim 1, characterized in that the pressure in the second control chamber (74; 156; 165; 202; 227) is kept practically constant by means of a direct connection (130) of the second control chamber (74; 156; 165; 202; 227) with the high-pressure supply conduit (31).
3. Fuel injection valve according to Claim 1, characterized in that during the opening movement of the injection valve member and respectively of the control piston (50; 122) an increase in pressure acting against this opening movement is generated in the second control chamber (74; 156; 165; 195; 212), the control device (3; 4; 5; 6; 7; 8; 9; 11; 13; 22) having relief elements (75, 77; 95; 103; 113, 117; 142, 151; 171, 175; 191; 214) for connecting the second control chamber (74; 156; 165; 195; 212) to the high-pressure supply conduit (31).
4. Fuel injection valve according to Claim 3, characterized in that means (64; 94; 98; 152; 162) are provided by means of which a rapid closing movement of the injection valve member and respectively of the control piston (50; 122) can take place.
5. Fuel injection valve according to Claim 4, characterized in that by the means (64; 94; 98; 152; 162) when the fuel pressure in the second control chamber (74; 156; 165) drops, a direct connection is freed from the high pressure conduit (33, 31) to one of the two control chambers (70; 156; 160) in order to effect a further acceleration of the control piston (50; 122).
6. Fuel injection valve according to one of the Claims 3 to 5, in which the first control chamber (70) is arranged between an upper end surface (56) of the control piston (50) and a fixed control body (52) provided with the outlet opening (59), characterized in that the control piston (50) has a reduced diameter piston part (51) and a corresponding piston shoulder surface (53), in that a displaceable sleeve (64; 94; 98) is arranged with a close sliding fit on the one side on the piston part (51) and on the other side in the guide hole (29), in that the second, annular control chamber (74) is bounded radially by the piston part (51) and the guide hole (29) and axially at least by the piston shoulder surface (53) and a lower end surface (65) of the sleeve (64; 94; 98), and in that the sleeve (64; 94; 98), which is in contact by means of a sealing surface (66; 96) on the control body (52) when the pressure in both control chambers (70; 74) is the same as well as during the opening movement of the control piston (50), during the closing movement of the control piston (50) at a given pressure drop in the second control chamber (74) frees a connection between the high-pressure fuel supply conduit (33) and the first control chamber (70).
7. Fuel injection valve according to one of the Claims 3 to 6, characterized in that the relief elements are formed by a connecting bore (75) provided with a throttle (77) and connecting the second control chamber (74) with the high-pressure supply conduit (33).
8. Fuel injection valve according to one of the Claims 3 to 6, characterized in that the relief elements are formed by a ball non-return valve (103).
9. Fuel injection valve according to one of the Claims 3 to 6, characterized in that the relief elements are formed by valve (113), the valve body (114) of which is provided with a throttle hole (117) connecting the second control chamber (74) to the high-pressure supply conduit (33) when the seat (115) of the valve is closed.
10. Fuel injection valve according to Claim 6, characterized in that the sleeve (94) has at the circumference a plurality of ribs (95) arranged axially in series, everyone of which is forming an annular gap (93) relative to the guide hole (29), the ribs (95) forming the relief elements in the connection of the second control chamber (74) with the high-pressure supply conduit which opens into the guide hole (29) above the uppermost rib (95).
11. Fuel injection valve according to Claim 6, characterized in that the sealing surface (66; 96) of the sleeve (64; 94; 98) is provided with a plurality of depressions (97) which form the inlet throttle connection between the high pressure supply conduit (33) and the first control chamber (70).
12. Fuel injection valve according to one of the Claims 1 to 3, having a fixed-location control body (135) provided with the outlet opening (159), characterized in that the control body (135) is provided with a recess (136) into which protrudes an upper, reduced diameter piston part (123) with a close sliding fit to permit displacement, and in that the first, annular control chamber (155) is radially bounded by the piston part (123) and by the guide hole (121) and is axially bounded by a piston shoulder (126) and a lower end surface (139) of the control body (135).
13. Fuel injection valve according to one of the Claims 1 to 3, having a fixed-location control body (135) provided with the outlet opening (159), characterized in that the control body (135) is provided with a recess (136) into which an intermediate piston (162) protrudes with a close sliding fit, which is operatively connected by means of a sealing surface (168) to an upper end surface (161) of the control piston (122), and in that the first, annular control chamber (160) is radially bounded by the intermediate piston (162) and the guide hole (121) and is axially bounded by the upper end surface (161) of the control piston (122) and a lower end surface (139) of the control body (135).
14. Fuel injection valve according to Claim 12, characterized in that the second control chamber (156; 195) is formed above a piston end surface (127) in the recess (136) and is connected by means of a throttle (142; 191) to a connecting hole (130), which is arranged centrally in the control piston (122), to the high-pressure supply conduit (31).
15. Fuel injection valve according to Claim 13, characterized in that the second control chamber (165) is formed above an end surface (163) of the intermediate piston (162) in the recess (136) and is connected by means of a throttle (175) to a connecting hole (130), which is arranged centrally in the control piston (122), to the high-pressure supply conduit (31).
16. Fuel injection valve according to Claim 5, Claim 12 and Claim 14, characterized in that the upper piston end surface (127) is associated with a valve seat disc (140) provided with the throttle (141) and separating the second control chamber (156) from the connecting hole (130), which valve seat disc (140) forms, together with the piston end surface (127), a valve flat seating (152) which, when there is a certain drop in pressure in the second control chamber (156) during the closing event, frees the direct connection between the second control chamber (156) and the connecting hole (130) and, by this means, permits the piston to be directly subjected to the high fuel pressure.
17. Fuel injection valve according to Claim 16, characterized in that the piston part (123) is provided with a recess (128) in which is arranged an axially movable valve body (143) provided with the throttle (142), in that the valve seat disc (140) has a disc hole (141) which can be closed by the valve body (143) with the exception of the throttle (142), and in that the valve seat disc (140), together with the valve body (143), forms a further valve flat seating (151) for relieving the second control chamber (156) when there is a given pressure rise during the opening motion of the control piston (122).
18. Fuel injection valve according to Claim 5, Claim 13 and Claim 15, characterized in that the intermediate piston (162), which is in contact by means of the sealing surface (168) with the end surface (161) of the control piston (122) when there is the same pressure in both control chambers (160, 165), frees the connection between the connecting hole (130) or the high-pressure supply conduit (31) and the first control chamber (160) when during the closing movement of the control piston (122) a given pressure drop in the second control chamber (165) takes place.
19. Fuel injection valve according to Claim 3 and Claim 15, characterized in that the intermediate piston (162) is provided with a recess (170) which is connected to the connecting hole (130) and in which is arranged a valve (171) closing a connecting bore (174) between the recess (170) and the second control chamber (165) in order to relieve the second control chamber (165) at a given pressure rise during the opening movement of the control piston (122).
20. Fuel injection valve according to Claim 15 and Claim 19, characterized in that the throttle (175) is manufactured parallel to the connecting hole (174) in the intermediate piston (162) and opens into the recess (170).
21. Fuel injection valve according to Claim 3 and according to either of Claims 12 or 13, characterized in that the first control chamber (155; 160) is connected to the outlet opening (159) by means of a connecting groove (157) on the periphery of the control body (135) and by means of a transverse hole (158) in the control body (135).
22. Fuel injection valve according to Claim 3 and Claim 12, characterized in that the first control chamber (155) is connected to the high-pressure supply conduit (31) by means of an inlet throttle (133) which is manufactured in the piston part (123) and which opens radially into a central connecting hole (130) of the control piston (122).
23. Fuel injection valve according to Claim 3 and Claim 13, characterized in that the first control chamber (160) is in connection with the high-pressure supply conduit (31) by means of an inlet throttle (184) manufactured in the intermediate piston (162) and opening radially into a central hole (180) of the intermediate piston (162).
24. Fuel injection valve according to Claim 3 and Claim 13, characterized in that the sealing surface (168) of the intermediate piston (162) is provided with a plurality of depressions which form the inlet throttle connection between the high-pressure supply conduit (31) and the first control chamber (160).
25. Fuel injection valve according to Claim 12, Claim 14 and Claim 21, characterized in that the second control chamber (195) is connected onto the transverse hole (158) by means of a hole (196) manufactured in the control body (135) and provided with a throttle (197) and is therefore in connection with the first control chamber (155).
26. Fuel injection valve for the intermittent injection of fuel into the combustion space of an internal combustion engine, particularly according to one of the Claims 1 to 25, having a housing (120), having a valve seat element (19) provided with injection openings (21), having a longitudinally displaceable injection valve member (24) mounted in the housing (120) for closing or opening the injection openings (21), having a control device (13) for controlling the displacement movement of the injection valve member (24), the control device (13) having a control piston (122) guided so as to be longitudinally displaceable in a guide hole (121) and being connected to the injection valve member (24) and being subjected on one side to the system fuel pressure from a high-pressure fuel supply conduit (31) and on the other side to the fuel control pressure in a control chamber (226), the control chamber (226) being in connection with the high-pressure fuel supply conduit (31) by means of at least one inlet opening (258), and the control pressure in the control chamber (226) being controllable by opening or closing at least one outlet opening (259), whereto the control device (13) is provided with a controllable pilot valve (80, 81, 82), characterized in that the control device (13) has a second chamber (227) which is connected continuously to the high-pressure supply conduit (31), which is foreseen in a recess (218) in the control piston (122) and which is closed by one end-side of a control element (221) arranged in the recess (218), the control element (221) being movable relative to the control piston (122), whereby the pressure in the second chamber (227) acts in opposition to the opening movement of the injection valve member (24) and respectively of the control piston (122) and presses the other end-side of the control element (221) against a housing-fixed stop (220), and whereby a displacement movement of the control piston (122) relative to the control element (221) supported against the housing-fixed stop (220) changes the volume of the second chamber (227).

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