JP2587047B2 - Fuel injection device for internal combustion engines - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection device for an internal combustion engine, particularly a diesel engine, and a plurality of injection nozzles and a distribution for continuously discharging a fuel injection amount to each injection nozzle. Type injection pump is provided, and in this case, the injection amount is divided into a pre-injection amount and a main injection amount which are injected one after another, and further, a pump work chamber of the distribution type injection pump and An electromagnetically controlled valve device for controlling the opening and closing between the pressure relief conduit and the pressure relief conduit is provided. The valve device closes the pump working chamber with respect to the pressure relief conduit at the time of the pre-injection and the main injection, and at the end of discharge. For the pressure drop control in (1), the present invention relates to a type in which a predetermined flow cross section to a pressure relief conduit is controlled to open.

2. Description of the Related Art In a diesel engine having a direct injection type fuel injection device, there is a problem of noise due to shocking combustion. According to the experiment, the required injection amount during the discharge time is about 3-5m
It has been found that the noise is significantly reduced by dividing the pre-injection amount as small as m ³ into the main injection amount injected before and after the pre-injection at a predetermined time interval.

In known fuel injectors of the type mentioned at the outset, a deflection piston is provided which is preloaded via a spring in order to obtain a pre-injection and a main injection during the delivery time of the dispensing injection pump, The displacement piston releases a prescribed volume above the prescribed injection pressure, whereby the discharge pressure drops in a short time to below the closing pressure of the injection nozzle, and thus the injection nozzle is moved by the nozzle needle. Will be closed. In this case, however, it is necessary to accept operating characteristics which vary on the basis of the temperature-related hydraulic effect.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a fuel injection device whose operating characteristics do not change depending on the temperature and the like, and which can always maintain specified good operating characteristics.

According to one aspect of the invention, a fuel injection device of the type described at the outset is characterized in that the flow cross section of the valve device is adjustable in at least two stages. In addition, the valve device is configured such that during the discharge time, the flow cross-section that is reduced compared to the flow cross-section that is completely opened at the end of discharge is controlled to be opened for a short time.

Advantageous Effects of the Invention The fuel injection device configured as in the present invention has an advantage that a fluctuating operating characteristic is avoided as compared with a known device. By setting the flow cross sections, which are controlled open to the pressure relief conduit after the pre-injection and after the main injection, differently as in the present invention, two essential requirements for an optimal injection process are: The requirement that the time interval between the pre-injection and the main injection be small even at a high engine speed, and that the pressure drop control cross-section at the end of the main injection is large due to the rapid disappearance of pressure at the end of discharge. Can meet with your request. In this case, the flow cross section that is controlled to open depends on the size of the valve opening and the value of the opening stroke of the valve member. That is, a short switching time of the valve device can be achieved when the opening stroke is small.

Embodiments Advantageous embodiments of the fuel injection device according to the invention are possible by means of the dependent claims.

For example, when configured as claimed in claim 2, an adjustable flow cross section at a certain valve opening influences the opening stroke of a valve member configured as a slider or a push rod. Obtained by

By means of the advantageous embodiments of claims 3 and / or 4, different adjustments of the opening stroke to at least two different predetermined values can be realized relatively simply.

According to an advantageous embodiment of the invention, a mechanical damping of the valve element is produced at the end of the pre-injection, so that the valve element does not spring during a brief opening of the solenoid valve. You.

According to the advantageous embodiment of claim 6, the switching time for the first closing of the solenoid valve at the start of the discharge can be very short. This is because in this case the closing distance of the valve member is already set to a small stroke distance.

An advantageous embodiment according to claim 8 serves to significantly reduce the switching time of the solenoid valve during opening and closing.

Furthermore, according to an embodiment of the invention, the flow cross-sections determined for the opening control have solenoid valves connected in parallel with valve openings having different opening cross-sections. Adjusted by. This makes it possible to obtain an extremely short switching time when the solenoid valve is opened based on a smaller stroke distance, in which case it is necessary to abandon the large pressure drop control cross section at the end of the main injection, and It is also necessary to accept a large pressure drop control cross section at the end, i.e. a large pressure drop control cross section which can cause an unacceptably large gap between the pre-injection and the main injection due to a very large discharge pressure drop. Absent.

Embodiment Next, an embodiment of the present invention will be described with reference to the drawings.

The fuel injection device for a diesel engine, partially shown in FIG. 1, has a plurality of injection nozzles, here four injection nozzles 10, each of which is connected via one injection conduit 11. To the connecting pipe piece 12 of the fuel distribution type injection pump 13.

A barrel 15 is disposed in a casing 14 of the distribution type injection pump 13, and in this barrel 15, a plunger 16 performs a reciprocating motion and a rotating motion simultaneously. The plunger 16 is driven by a cam driving device 17 via a shaft 18, and the shaft 18 rotates at half the rotational speed of the diesel engine. The pump working chamber 19 is restricted by the plunger 16 and the barrel 15, and fuel is supplied to the pump working chamber 19 from the suction chamber 21 in the casing 14 of the distribution type injection pump 13 via the supply passage 20. Fuel is sequentially distributed from the pump working chamber 19 toward the radial discharge hole 24 through the axial center hole 22 and the radial distribution hole 23. These discharge holes
24 are connected to the connection pipe pieces 12 respectively. Plunger
In the end area of 16 there are provided longitudinal grooves 25 which open into the end face of the plunger 16 which restricts the pump working chamber 19 and which are supplied during the suction stroke of the plunger 16. The passage 20 and the pump working chamber 19 are connected. Suction chamber
Numeral 21 is filled with fuel from a fuel tank 27 by a feed pump 26 and is connected via a pressure regulating valve 28 to a return conduit 29 opening to the fuel tank 27.

An electromagnetically controlled valve device 30 is integrally incorporated in the casing 14, and an electrical connection terminal 31 of the valve device 30 is connected to a switching signal transmitter 32. The valve device 30 is shown partially cut away in FIG. 1, and the inlet 33, shown in cross section, is open in the pump working chamber 19 and is located on the suction side of the plunger 16, here the supply passage 20. And a pressure release passage 34 connected to the pressure release passage 34. The valve device 30 closes the pump working chamber 19 from the pressure relief passage 34 for the discharge time, and at the end of the discharge, a predetermined flow cross section to the pressure relief passage 34 for rapid pressure disappearance in the pump working chamber 19. Open control.

A first embodiment of the electromagnetically controlled valve device 30 is shown in longitudinal section in FIG. The valve device 30 has a valve casing 35 which can be screwed into the casing 14 of the distribution type injection pump 13, in which a solenoid valve 36 and an adjusting magnet 37 are mounted. Each of the solenoid valve 36 and the adjusting magnet 37 has a core 38, 39 made of a ferromagnetic material, and the core 38, 39 holds a ring-shaped magnet coil 40, 41 inside a bowl. Core 38,39
Are covered by plates 42, 43, respectively, which have a central through hole,
A central cylindrical tube piece of the mover 44; 45 extends through the through hole. The movers 44 and 45 are attached to the cores 38 and 39 and the movers 44 and 45
Are positioned opposite each other with a gap 46; Guide bushes 48; 49 are arranged in the openings of the cores 38, 39, respectively. In the guide bush 48, the valve member 50 and in the guide bush 49 the adjusting piston 51 are guided in two guide sections 501, 502; 511, 512, respectively. The valve member 50 and the adjusting piston 51 have, on the end side, crimping plates 503, 513, respectively, which protrude into the hollow cylindrical tube piece of the armatures 44, 45 and are firmly connected to the armatures. Have been. Movers 44 and 45 are valve opening springs 52
The springs are kept in the open position under the action of a return spring 53, and both springs respectively move the pressure plates 503; 513 to the mover 44;
It is pressed against 45 ring-shaped contact shoulders 441; 451. The valve opening spring 52 and the return spring 53 are supported on the annular shoulders of the associated guide bush 48; 49, respectively.

The valve member 50 cooperates with the valve seat 54 at an end-side valve head 504,
The valve seat 504 surrounds the valve opening 55. Valve opening 55
Restricts the inflow hole 33 opened in the pump working chamber 19 of the distribution type injection pump 13. Inflow hole 33, valve opening 55, and valve seat
The valve seat 54 is attached to a valve seat 56, which forms a hollow chamber 57 together with the ring-shaped core 38, from which an outlet hole 58 communicates with the pressure release passage 34. . The guide bush 48 protrudes beyond the core 38 to the valve seat 56 and an annular chamber 59.
The annular chamber 59 is connected to the hollow chamber 57 via a connection hole 60 in the guide bush 48.

The adjustment piston 51 of the adjustment magnet 37 extends through the central opening in the armature 44 of the solenoid valve 36 and engages with the pressure plate 503 of the valve member 50 there. On the opposite side, the adjusting piston 51 is in contact with a stop 61 which is stationary with respect to the casing at its crimp plate 513. The magnet coil of the solenoid valve 36 and the adjustment magnet 37 via the connection terminal 31
An excitation current is supplied to 40 and 41.

With the aid of the adjusting magnet 37, the flow cross section between the valve seat 54 and the valve head 504 of the valve member 50 can be adjusted in two stages when the valve member 50 is opened. This is based on that opening stroke of the valve member 50 is adjustable in two values h ₁ and h _2, in this case h ₁ is greater than h _2. Adjustable magnet 37
When is not energized, the adjusting piston 51 occupies the position shown in FIG. The valve member 50 is in contact first the adjusting piston 51 in its crimped plate 503 after traveling up stroke h _1. When the adjusting magnet 37 is excited, the armature 45 is attracted, and the adjusting piston 51 moves toward the valve member 50 so that the guide section 512 moves the stopper 6 which is immovable with respect to the casing.
Exercise until you touch 2. Adjusting piston 51 is adjusted distance h
_a Only by this way to axial movement, the valve member 5
Opening stroke of 0 is reduced by the adjustment path h _a, pressure disk 503 of the valve member 50 during the opening of this result the solenoid valve 36 is in contact with the opening stroke h ₂ = h ₁ -h already adjusting piston 51 after _a Will be.

Next, the mode of operation of the valve device 30 in connection with the distribution type injection pump 13 will be described with reference to the diagram shown in FIG. In this case, the diagrams a to g respectively show the cam stroke h _N (a) of the cam drive 17 corresponding to the axial stroke of the plunger 16 and the feed pressure p (b) generated in the pump working chamber 19 as a function of time t. The stroke h _D of the nozzle needle in the injection nozzle 10 (c), the stroke of the valve member 50 of the solenoid valve 36
h _V (d), switching pulse (e) for solenoid valve 36, switching pulse (f) for adjusting magnet 37 and solenoid valve 36
Are shown in FIG.

An electromagnetic valve 36 and adjusting the magnet 37 is controlled together in time t _1. Solenoid valve 36 is closed, the opening stroke of the valve member 50 is fixed to a small value h _2. Solenoid valve 36 after solenoid valve 36 is closed
Is limited to the holding current i _H1 . The plunger 16 reaches its bottom dead center at time t _N, begins its discharge stroke. After the pressure p in the pump working chamber 19 rises and exceeds the nozzle needle closing pressure (nozzle opening pressure p _D )
Then, the nozzle 10 is opened and the pre-injection starts.

Solenoid valve 36 at time t ₂ is cut off. The valve member 50 is opened until the opening stroke h ₂ that has been modulated. The pressure in the pump working chamber 19 drops and falls below the nozzle opening pressure. The nozzle needle closes again and the pre-injection ends. Exciting current i
Disappears quickly and is then increased to the holding current i _H2 . This eliminates a dead time when the solenoid valve 36 is re-input.

Total current is again supplied to the solenoid valve 36 at time t _3. Solenoid valve 36 is closed, the pressure p is increased again in the pump work chamber, the main injection is started with above the nozzle opening pressure p _D. Excitation of the adjusting magnet 47 is shut off at time t _3, whereby the adjusting piston 51 is returned to the position shown in Figure 2 through the springs 53 return. This entire opening stroke h ₁ for the valve member 50 becomes available.

Exciting current of the solenoid valve 30 is cut off again at the instant t _4. Under the action of the valve opening spring 52, the valve member 50
Move to the stop in. Through the now available large flow cross-section between the valve seat 54 and the valve head 504, the pressure in the pump work chamber 19 is rapidly reduced. As soon as the nozzle opening pressure p _D is lower than the closing of the nozzle needle starts, the main injection ends.

FIG. 3 shows another embodiment of the electromagnetic valve device 30 shown in FIG. This embodiment is different from the electromagnetic valve device 30 shown in FIG.
The only difference is that a mechanical damping device is provided in order to prevent the valve member from bouncing or displacing in the event of a collision of the 37 with the adjusting piston 50 '. For this purpose, a damping push rod 63 is guided slidably in the axial direction inside the adjusting piston 51 '. The buffer rod 63 extends over the entire length of the adjusting piston 51 'and projects at both end faces of the adjusting piston 51'. At the end opposite to the valve member 50, the shock-absorbing rod 63 has a support plate 64, on which a shock-absorbing spring 65 supported on the casing side acts. The spring force of the buffer spring 65 is set smaller than the spring force of the valve opening spring 52. At the end facing the valve member 50, the buffer push bar 63 contacts the pressure plate 503 of the valve member 50 under the action of a buffer spring 65. When the solenoid valve 36 is turned on and therefore closed, the damping push rod 63 projects beyond the adjusting piston 51 'by a predetermined value at the end facing the valve member 50. Now, when the solenoid valve 36 is shut off and the valve member 50 moves toward the adjusting piston 51 'under the action of the valve opening spring 52, the valve member 50
Is a shock-absorbing rod before contacting the adjusting piston 51 '.
Hit 63. As a result, the movement of the valve member 50 is damped in advance. Otherwise, the valve device 3 shown in FIG.
Since all the components of 0 'are the same as those of the valve device 30 in FIG. 2, the same components are denoted by the same reference numerals.

A further embodiment of the electromagnetic valve device 30 in FIG. 1 is designated by the reference numeral 30 "in FIG. 4. The valve device 30" is a valve device 30 'in FIG. 2 and a valve in FIG. Device 3
The only difference is in the configuration of the adjusting piston 51 "of the adjusting magnet 37 and 0", so that identical parts are denoted by the same reference numerals.

In the guide bush 49, the adjusting piston 51 ″ slidable axially in the guide sections 511, 512 comprises two piston sections 66.
And 67, in this case one piston section
66 has a guide section 511 and a pressure plate 513, while the other piston section 67 has a guide section 512. A piston spring 68 is supported between the two piston sections 66, 67 and thus loads the piston section 66 towards the armature 45 and the piston section 67 towards the valve member 50. . The guide bush 49 has a stop shoulder 69 projecting radially inward, with which the guide section 512 of the piston section 67 contacts under the action of the piston spring 68. Both pistons division 66 and 67 in this position is at a distance h _A therebetween. Since the spring force of the piston spring 68 is set to be greater than the spring force of the valve opening spring 52, the valve member 50 is pushed by the piston section 67 against the force of the valve opening spring 52. The stopper shoulder 69 of the guide bush 49 is
Piston section 67 in contact with the valve member 50, the valve member 50
Stroke h _V of accounts for position is moved so as to be adjusted to a small value h _2. When the adjusting magnet 37 is energized, the piston section 67 is fixed to the stop shoulder 67 by the piston section 66, whereby the piston spring 68 is deactivated.

The mode of operation of the electromagnetic valve device 30 "is almost the same as the mode of operation of the valve device 30 and can be explained without difficulty using the diagram shown in Fig. 6. The individual diagram a in Fig. 6 The meaning of .about.g is the same as each diagram a.g in FIG. 5. The opening stroke of the solenoid valve 36 or its adjusting member 50 is also described.
All diagrams other than diagrams d indicating the time elapsed h _V is consistent. Stroke of the adjustment member 50 prior to the excitation of the adjusting piston 51 adjusting magnet 37 and the magnet valve 36 constructed in accordance with that are different for "is adjusted already to a small value h _2. When the solenoid valve 36 is energized , the valve member 50 since it is sufficient move only the small stroke distance h ₂ to close the solenoid valve 36, the movable element 45 is attracted by the power supply. regulatory magnet 37 short switching time by the time the closing of the solenoid valve is obtained is, the mover 45 moves the piston segment 66 the piston segment 67 together with the piston segment 66 firmly fixed to the stopper shoulder 69. during the first opening of the solenoid valve 36 at time t ₂ Thus the valve member 50 opening stroke h _V Controlled magnet 37 at. the time t ₃ when being limited to a small value h ₂ is cut off, adjusting piston 51 'occupies the position shown in Figure 4. The spring force of the piston spring 68 when the second opening of the solenoid valve 36 is overcome on the basis of the higher pressure in the pump working chamber 19 at time t _4, as a result the valve member 50 is the maximum opening stroke h ₁
= Perform h ₂ + h _A. After the pressure p has dropped in the pump working chamber, the adjusting element 50 is moved by the piston spring 68 into the piston section 67.
Again through the pushed back, stroke h _V made by the valve member 50 when closing of the solenoid valve corresponds to a value h ₂ of the opening stroke.

FIG. 7 shows a block circuit diagram of the switching signal generator 32 in FIG. The control signal for the solenoid valve 36 is calculated by the calculator 70 from the stored characteristic line area. This characteristic line region has the control signal φ _m in the form of a control angle (m = 1, 2, 3, 4) as a function of the engine speed n, the load d and the fuel temperature T. Furthermore, reference marks BZ, for example, which relate to the top dead center of the plunger 16, are taken into account. Characteristic line region of the desired course of the nozzle needle h _D are stored as a function of the parameters in another calculator 71 supplementary. Each injection nozzle 10 is provided with a sensor 72 (see FIG. 1) which detects the actual course of the nozzle needle stroke and switches it as an electrical signal to a switching signal transmitter 32.
Where these switching signals are provided to a comparator 73 in a time multiplex. Adjusting difference between the desired course of the nozzle needle stroke by actual elapsed and the stored characteristic line region of the nozzle needle stroke is supplied to the calculator 70 for control signals phi _m modification. At this time, the control value extracted from the characteristic line area of the calculator 70 is
The adjustment difference is changed to be as small as possible. The control signal φ _m is supplied to a current regulator 74 which supplies an exciting current to the magnet coil 40 of the solenoid valve 36 (the course of this exciting current is shown in the diagrams g of FIGS. 5 and 6). You.

Another possibility of correcting the control signal can be achieved by detecting the discharge pressure p in the pump working chamber 19. For example the pressure level at the time point t ₂ (see FIG. 5b and Figure 6b)
The it is possible to infer the variations in the injection quantity between the injection nozzle based, variation in the injection quantity can be compensated for by a corresponding change in the switching time point t ₂ of the solenoid valve 36. In addition, the cam or plunger
The advantage is obtained of defining the exact start of the 16 discharge strokes. The adjustment error can therefore be corrected by automatic post-adjustment of the characteristic line area. This is particularly advantageous for direct injection dispensing injection pumps. This is because in this case very steep cams are used, which cause large injection quantity variations even with small misadjustments.

FIG. 8 schematically shows another embodiment of the fuel injection device. The fuel tank is code 80, the fuel feed pump is code 80
At 81, the fuel dispensing injection pump is designated by the reference numeral 82. The dispensing injection pump 82 is constructed identically to the distributing injection pump 13 shown and described in FIG. The dispensing injection pump 82 is connected in a similar manner to the fuel tank 80 via the return line 83.
And a plurality of injection nozzles 85 via an injection conduit 84. As in FIG. 1, the dispensing injection pump 82
Is connected to an electromagnetically controlled valve device 87, which is connected on the one hand to the pump working chamber of the dispensing injection pump 82 and on the other hand to a pressure relief conduit 86, for discharging the pump working chamber. Connects to conduit 86 and disconnects pumping from pressure relief conduit 86 during the discharge time.

As in the fuel injection device shown in FIG. 1, in this case as well, the amount of fuel respectively injected into the cylinder of the diesel engine via the injection nozzle 85 during the discharge time of the distribution type injection pump 82 is temporally different. And the main injection amount. For this purpose the valve device 87
Has two solenoid valves 88, 89 connected in parallel to one another, the valve openings of both solenoid valves having different opening cross sections. In this case, the solenoid valve 88 has a small valve opening cross section, which is indicated by a restriction in the through hole of the solenoid valve 88. The magnet coils 90, 91 of both solenoid valves 88, 89 are likewise connected to a switching signal transmitter (not shown for clarity).

The mode of operation of the dispensing injection pump 82 connected to the valve device 87 can be seen from the diagram shown in FIG. As in FIGS. 5 and 6, these diagrams respectively show the cam stroke h _N (a), the pressure p (b) in the pump working chamber, the nozzle needle stroke h _D (c) in the injection nozzle as a function of time, The switching pulse (e) at the solenoid valve 88 and the switching pulse (f) at the solenoid valve 89 are shown.
The diagrams a to f are shown the same as the diagrams in FIGS. 5 and 6.

Both solenoid valves 88 and 89 are closed is input at time t _1, the pressure p in the pump working chamber of the distributor-type injection pump 82 is increased with the start of the cam discharge stroke at time t _N (see b of FIG. 9) . Nozzle needle after excess of the nozzle opening pressure p _D is lifted from the nozzle opening, before the injection begins.

Electromagnetic valve with a small valve opening cross section at time t ₂ 8
Is shut off. During the opening movement of the solenoid valve 88, the pressure p in the pump working chamber of the dispensing injection pump 82 drops quickly.
The pressure drop slows after the end of the valve stroke.

Solenoid valve 88 at time t ₃ is closed is again energized.
Discharge pressure p rises in the pump work chamber, the main injection after the excess of the nozzle needle opening pressure pp _D begins.

Both solenoid valves 88 and 89 is opened is cut off at time t _4. A large flow cross section is now used for pressure drop control of the discharge pressure p. The discharge pressure drops sharply, the nozzle needle of the injection nozzle 85 returns and closes the nozzle opening, thereby ending the main injection.

[Brief description of the drawings]

FIG. 1 is a partial view of a fuel injection device for a diesel engine, and FIGS. 2, 3, and 4 show different types of electromagnetic valve devices of the fuel injection device shown in FIG. FIGS. 5 and 6 show three embodiments, which show the time course of different parameters in the fuel injection system shown in FIGS. 1 and 2 or FIGS. 1 and 4. FIG. Diagram,
FIG. 7 is a block circuit diagram of a switching signal transmitter for the valve device of the fuel injection device shown in FIG. 1, FIG. 8 is a schematic diagram showing a fuel injection device according to another embodiment, and FIG. FIG. 9 is a diagram showing the time course of various parameters in the fuel injection device shown in FIG. 8; 10 ... injection nozzle, 11 ... injection conduit, 12 ... connecting pipe piece,
13 ... distributing type injection pump, 14 ... casing, 15 ... barrel, 16 ... plunger, 17 ... cam drive device, 18 ...
Shaft, 19: Pump working chamber, 20: Supply passage, 21: Suction chamber, 22: Center hole, 23: Distributing hole, 24: Discharge hole, 25
…… Vertical groove, 26 …… Feed pump, 27 …… Fuel tank,
28 ... pressure regulating valve, 29 ... return conduit, 30, 30 ', 30 "... valve device, 31 ... connection terminal, 32 ... switching signal transmitter, 33 ...
Inlet, 34 …… Pressure release passage, 35 …… Valve casing, 36 ……
Solenoid valve, 37 Adjustment magnet, 38, 39 Core, 40, 41
…… Magnet coil, 42,43 …… Plate, 44,45 ……
Movable element, 46,47 …… Gap, 48,49 …… Guide bush, 50…
... Valve member, 51, 51 ', 51 "... Adjusting piston, 52 ... Valve opening spring, 53 ... Return spring, 54 ... Valve seat, 55 ... Valve opening,
56 ... valve seat, 57 ... hollow body, 58 ... outlet hole, 59 ... annular chamber, 60 ... connection hole, 61, 62 ... stopper, 63 ... buffer rod, 64 ... support plate , 65 ... cushioning spring, 66, 67
…… Piston section, 68… Piston spring, 69… Stopper shoulder, 70,71… Calculator, 72… Sensor, 73… Comparator, 74… Current regulator, 80… Fuel tank, 81… Feed pump, 82… Distribution type injection pump, 83 …… Return conduit, 84 …… Injection conduit, 85 …… Injection nozzle, 86 …… Pressure release conduit, 87 …… Valve device, 88,89 …… Solenoid valve, 90,91 ... Magnet coil

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Walter Tegen Vaipuringen 7, Im Reisgar 4 Germany (56) References JP-A-60-125754 (JP, A)

Claims (11)

(57) [Claims] 1. A fuel injection device for an internal combustion engine, comprising: a plurality of injection nozzles; and a distribution type injection pump for continuously discharging a fuel injection amount to each of the injection nozzles. Are divided into a pre-injection amount and a main injection amount that are injected one after another, and furthermore, an electromagnetic control type that controls opening and closing between a pump working chamber of a distribution type injection pump and a pressure relief conduit. A valve device is provided, which closes the pump working chamber with the pressure relief conduit during pre-injection and main injection and provides a predetermined pressure to the pressure relief conduit for pressure drop control at the end of discharge. Of the valve device (30; 30 '; 30 "; 87), wherein the flow cross section of the valve device (30; 30';30"; 87) is adjustable in at least two stages. ; 30 '; 30 "; 87) is a flow cross section that is completely opened at the end of discharge during the discharge time A fuel injection device for an internal combustion engine, characterized in that it is configured to open-control a flow passage cross section reduced in a short time as compared with the above. 2. The valve device (30; 30 '; 30 ") having a valve opening (55).
A pump working chamber (19) of a dispensing injection pump (13) and a pressure relief conduit, comprising a valve seat (54) surrounding the valve seat and an axially movable valve member (50) cooperating therewith. (34) and a moving distance of the valve member (50) by at least two different stroke distances (h ₁ ,
h ₂₎ has a controllable stop for adjusting (51), the said stopper (51) is distributed type injection pump (1
During the discharge time of 5), the small stroke distance (h) of the valve member (50)
₂₎ and such a large stroke distance at the discharge ends (h ₁₎ is adjusted and controlled, the fuel injection device as set forth in claim 1, wherein the appended claims. 3. The fuel injection device according to claim 2, wherein the controllable stopper (51) is connected to the mover (45) of the adjusting magnet (37). 4. A valve member (50) is in contact with a movable element (44) of a solenoid valve (36) using a valve opening spring (52), and the movable element is connected to an electromagnet (40) of the solenoid valve (36). ), The valve member (5
The movable adjustment piston (51) forming a stopper is moved by an adjustment distance corresponding to a large stroke distance (h ₁ ) of the adjustment magnet (37) using a return spring (53). ) in contact to the movable member (45), the movable element has so advanced by adjustment path defined during feeding the adjusting magnet (37) (h _a), adjusting piston (5
1) penetrates the mover (44) of the solenoid valve (36) and the valve member (5)
A valve closing motion direction of 0) is adapted to engage the valve member, a defined adjustment path of the adjusting piston (51) (h _a) the valve large stroke distance member (50) (h ₁₎ a small stroke distance (h ₂₎ the difference equally set, patent fuel injectors ranging third claim of claim between. 5. Inside the adjusting piston (51 '), a damping rod (63) extending over the entire length of the adjusting piston is guided so as to be movable in the axial direction. Contacting one end of the adjusting piston (51 ') under the action of a buffer spring (65) supported on the casing side,
In this position, the other end facing the valve member (50) projects by a predetermined value, and the spring force of the buffer spring (65) is set to be smaller than the spring force of the valve opening spring (52). The fuel injection device according to claim 4, wherein: 6. An adjusting piston (51 ") is divided into a first piston section (66) and a second piston section (67), said piston section being located between said piston sections (66, 67). A piston spring (68) supported by the section is disposed, and the spring force of the piston spring is set to be greater than the spring force of the valve opening spring (52). The first piston section (66) is on the armature (45) of the adjusting magnet (37) and the second piston section (67) is on the stopper shoulder (69) immovable with respect to the casing in the direction of the valve member (50). The second piston section (67) is in contact with the first piston section (6) when the adjusting magnet (37) is energized.
5. The fuel injection device according to claim 4, wherein the fuel injection device is fixed to the stopper shoulder (69) by 6). 7. An exciting current is input to the adjusting magnet (87) together with the first closing of the solenoid valve (36) at the start of discharge, and is shut off again with the second closing of the solenoid valve (36) during the discharging time. Claims 3 to 6
The fuel injection device according to any one of the preceding items. 8. An exciting current (i) for the solenoid valve (36) is input for closing and is cut off for opening, and the exciting current (i) is maintained after closing. 8. The method according to claim 3, wherein the current is reduced to (i _H1 ), is quickly extinguished after opening, and is raised again to the holding current (i _H2 ). Item 13. The fuel injection device according to Item 1. 9. A two-piece valve device (87) connected in parallel with each other.
Two solenoid valves (88, 89), the valve openings of both solenoid valves having different opening cross sections, each of which connects the pump working chamber of the dispensing injection pump (82) with a pressure relief conduit (86). ) And a solenoid valve with a small cross-section valve opening (88)
2. The fuel injection device according to claim 1, wherein the valve is opened for a short time during the discharge time, and a solenoid valve (89) having a valve opening having at least a large cross section is opened at the end of the discharge. . 10. A control signal (φ _m ) for inputting and shutting off the valve device (30; 30 ′; 30 ″) is derived from a stored characteristic line region, and the characteristic line region corresponds to the control signal (φ _m ). φ _m ) in relation to the speed (n) and load (α) of the internal combustion engine, the fuel temperature (T) and the reference mark (BZ).
The fuel injection device according to any one of claims 1 to 9, wherein: 11. The course of the nozzle needle stroke (h _D ) is stored as a function of the engine speed (n) and load (α), the fuel temperature (T) and the reference mark (BZ) in the characteristic line range. cage, the nozzle needle stroke (h _D) of the actual value are adapted to be captured by the sensor (72), the nozzle needle stroke (h _D) of the actual elapsed and the nozzle needle stroke taken from the characteristic line region (h 11. The fuel injection device according to claim 10, wherein the control signal ([phi] _m ) extracted from the characteristic line region is modified by an adjustment error during the course of _D ).