JPS5857030A - Fuel ejection pump - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The invention relates to a fuel injection pump of the type defined in the preamble of claim 1. Fuel injection pumps have already been proposed in which the metering element projects into a regulating chamber in which a variable fluid pressure occurs. However, since this type of conditioning chamber is not constantly cleaned, vapor bubbles as well as fine dirt particles deteriorate the conditioning properties over time.

In contrast, the fuel injection pump according to the invention having the features of claim 1 provides that the electrohydraulic adjustment of the fuel injection pump can be performed in a simple manner and with no disadvantages in relation to the operating characteristics of the internal combustion engine. This has the advantage that it can be carried out without disturbing effects. In addition, the constant cleaning of the conditioning chamber removes vapor bubbles and any entrained dirt particles from the conditioning chamber, thereby avoiding interference with the conditioning properties.

Next, the depiction of the present invention will be specifically explained with reference to the embodiments shown in the drawings.

The first embodiment shown in FIG. 1 is a fuel injection pump for a multi-cylinder internal combustion engine, in which a distributor body 2 is arranged in a cylinder 1 and a distributor cylinder 3 and a fuel injection pump for a multi-cylinder internal combustion engine. It comprises a pump and a dispensing piston 4 guided in a dispensing cylinder 3. The pump and distribution piston holder has a radial passage 6 extending radially towards the outer circumference of this distribution piston 4 in a section projecting from the distribution body 2;
This radial passage 6 includes an axially extending load relief passage 7.
is open and this load-relieving passage 7 is connected to the end of the pump and distribution shaft which projects from the distributor body 2 starting from the piston end face 8 which projects into the pump working chamber 9. Ring slider 1 used as a metering member
0 is slidably supported, and its outer periphery is connected to the distributor 2.
It is sealed within the notch 11 of the holder so that it can slide. A stress-free seal is provided by the piston ring 12. The ring slider 10 has an annular groove 14 open towards the pump and distribution pistons;
From this annular groove 14 a load relief bore 15 extends into a suction chamber 16 in the pump casing 1, in which the end of the pump and distribution piston 4 opposite the piston end face 8 is located. The ring slider 10 is a movable wall inside the notch 11 that partitions an adjustment chamber 17, and a pressure spring 18 is arranged inside the adjustment chamber 17.
The pressure spring 18 is supported by the ring slider 10 and slides the ring slider 10 toward the stopper 19 in the notch 11. The throttle point 20 always connects the suction chamber 16 and the regulating chamber 17 and is preferably formed in the annular slide 10 .

Fuel supply is performed by a fuel supply pump 22. Fuel is drawn in from the fuel container 23 and supplied to the suction chamber 16 of the pump housing 1 via a fuel supply conduit 24 with a check valve 25 .

From the suction chamber 16 or the fuel supply conduit 24 to the pressure regulator 2
Via the return flow conduit 26 with 7, the fuel is guided back into the fuel container 23 when the pressure undesirably increases. A passage 28 extends from the suction chamber 16 into the distribution cylinder 3 , which in a suitable rotational position extends into the longitudinal groove 2 of the pump and distribution piston 4 , which opens into the pump working chamber 9 .
It is designed to match 9. In the load reduction passage 7,
A distribution groove 30 opening towards the outer circumference of the pump and distribution piston 4 is connected. In a suitable rotational position of the pump and the distribution piston, this distribution groove 30 is formed in a known manner by a distribution channel 31 which leads to an injection valve (not shown).
matches.

The pump and dispensing piston can be effected in a known manner with a rotational and axial movement by means of a rotary drive (not shown) with a stroke disk. From the regulating chamber 17, a regulating conduit 33 as a backflow conduit is guided back to the suction side of the fuel supply pump 22. A regulating pressure generator 34 is arranged in the regulating conduit 33 .
The regulated pressure generator 34 is controlled by an electrical control device 35, which is constructed as a solenoid valve, an electrohydraulic transducer, a nozzle-reflection solate construction, or the like. This control device 35 is supplied with operating characteristic values of the internal combustion engine which are varied by electrical signals.

These operating characteristic values include an accelerator position 36, a rotational speed 11, and an axial position 37 of the ring slider 10. Ring slider lOO axial position is determined by appropriate stroke position signal transmitter 3
8. For example, by a known shorting ring device as shown,
Or confirmed by an inductive stroke position signal transmitter.

During operation of the internal combustion engine, the regulating pressure generator 34 regulates the pressure in the regulating chamber 17 in relation to a regulating signal provided by the electronic control device 35 . This regulation signal is based on operating characteristic values of the internal combustion engine. Thereby, the ring slider 10 is shifted to a position corresponding to a desired injection amount due to the pressure difference between the suction chamber 16 and the adjustment chamber 17.

An annular groove 1 in which a radial passage 6 connects with a suction chamber 16
4, fuel injection ends.

If regulating pressure generator 34 is designed as a solenoid valve, this solenoid valve is advantageously controlled periodically, ie preferably at the injection frequency. When the regulating pressure generator 34 is opened, the regulating chamber 17 is relieved of its load on the suction side of the fuel supply pump 22, and the pressure in the suction chamber 16 moves the ring slider 10 against the force of the pressurizing spring 18. to the so-called starting position. This starting position is located in the radial passage 6
does not overlap the annular groove 14 of the ring slider 10, so that the entire amount of fuel supplied from the pump working chamber 9 is injected. When the regulating pressure generator 34 is closed, the regulating conduit 33
Since the fuel does not flow back through the suction chamber 17, a fuel pressure similar to that generated in the suction chamber 17 is also created in the annular chamber 17 through the throttle point, and the pressurizing spring 18 causes the ring slider 10 to move to the stopper 19. Make it move towards you. In this so-called standstill position, the radial channel 6 is always connected to the annular groove 1.
4, the entire amount of fuel supplied from the pump working chamber is guided back to the suction chamber 16 and no fuel injection takes place. When the internal combustion engine is in a stopped state, the regulating pressure generator 34 opens to open the regulating chamber 17 to the suction side of the fuel supply pump 22 . Via the throttle point 20, a pressure compensation between the suction chamber 16 and the regulating chamber 17 takes place, and the pressure spring 18 moves the ring slide lO into the so-called rest position at the stop 19. When the internal combustion engine is started, a pressure increase is created in the suction chamber 16 by the fuel supply pump 22, which forces the ring slide 10 into the so-called starting position and injects the maximum amount of fuel. Ru. Then, based on the regulation signal provided by the electrical control device, the regulation pressure generator 34
is controlled in such a way that the required position of the ring slider 1o is adjusted.

In the second embodiment shown in FIG. 2, the same reference numerals are used for members that are similar to those in the first embodiment shown in FIG. 1 and have similar functions. The difference from FIG. 1 is that in this second embodiment,
A pressure spring 18 is arranged in the suction chamber 16 and is supported on the one hand by a stop 19 and on the other hand by the ring slider 10, so that this pressure spring 18 pushes the ring slider 10 into the adjustment chamber 17. Slide it so that it hits the stopper 41 in the direction toward . Regulating conduit 33 is connected to the pressure side of fuel supply pump 22 . From the suction chamber 16 or the fuel supply line 24, a backflow line 26 is led back into the fuel container 23 via a throttle element 42, thereby providing a pressure drop relative to the supply pressure of the fuel supply pump 22. A further throttle element 43 can likewise be arranged in the fuel supply conduit 24 in order to reduce the pressure. As a result, when the regulating pressure generator 34 is opened and fuel is supplied from the fuel supply pump 22, the regulating chamber 1
At 7, an even higher pressure builds up in the suction chamber 16. When the internal combustion engine is in a stopped state, the suction chamber 16
A pressure compensation is obtained between the control chamber 17 and the adjustment chamber 17 via the throttle point 2o, and the pressure spring 18 moves the ring slide 10 into the so-called starting position at the stop 41.

During operation of the internal combustion engine, as a result of the control of the regulating pressure generator 34, the ring slide 10 moves more or less in the radial channel 6 against the force of the pressure spring 18 in relation to the pressure occurring in the regulating chamber. is moved until it completely overlaps the annular groove 14 and the operating stop position is obtained.

In the third embodiment shown in FIG. 3, the same reference numerals are used for parts that are similar to those in the two embodiments shown in FIGS. 1 and 2 and have similar functions. In the third embodiment shown in FIG. 3, similarly to the embodiment shown in FIG.
It is designed to move towards the future. This ring slider 10 according to FIG. 3 is not provided with an annular groove,
Its end face 44 facing the regulating chamber 17 is adapted to control a circumferential groove 45 in the pump and distribution piston 4 . This circumferential groove 45 is connected to the radial passage 6. When the internal combustion engine is in a stopped state, the ring slider 10 is in contact with the stopper 41 and in its starting position, in which case the ring slider 10 does not completely cover the circumferential groove 45 and is A throttle cross section 46 as a throttle point 45 is slightly opened to the adjustment chamber 17. The regulating conduit 33 extends from the regulating chamber 17 to the suction side of the fuel supply pump 22 . When the internal combustion engine is in operation, the regulating pressure generator 34 is connected to the electric control device 3.
5, the fuel reaching the regulating chamber 17 via the load relief channel 7, the radial channel 6 and the circumferential groove 45 is controlled to be more or less reduced via the regulating conduit 33. When the regulating pressure generator is closed, the ring slide 10 is moved against the force of the pressure spring 18 into its rest position. In this stop position, the Ringeslei/10 completely opens the circumferential groove 45.

In the third embodiment shown in FIG. 3 and the fourth embodiment shown in FIG. It is substituted by cross section 46. In the fourth embodiment shown in FIG. 4, the same reference numerals are used for the same members as in the embodiment shown in FIGS. 1 to 3. According to FIG. 4, similar to the embodiment shown in FIG. It has become. Ring slider 1
When the ring slider 1 is in contact with the stop horn 819, that is, for example, when the internal combustion engine is in a stopped state, the ring slider 1
0 completely opens the circumferential groove 45 of the pump and distribution piston Φ to the regulating chamber 17. The regulating conduit 33 extends from the regulating chamber 17 to the suction side of the fuel supply pump 22 .

When starting the internal combustion engine, the fuel supplied to the suction chamber 16 by the fuel supply pump 22 causes the ring slider 10 to move into the starting position. In this starting position ↑, only a small portion of the throttle cross section 46 in the circumferential groove 45 is open toward the adjustment chamber 17 .

All the embodiments described above have common advantages. They have the common advantage that the fuel injection amount can be easily controlled electro-hydraulically by the ring slider 10, and that the adjustment chamber 17 is constantly cleaned accordingly.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view of a first embodiment of the fuel injection pump according to the present invention, FIG. 2 is a partial sectional view of the second embodiment, and FIG.
The figure is a partial sectional view of the third embodiment, and FIG. 4 is a partial sectional view of the fourth embodiment. 1'' Bonzo casing, 2... Distributor, 3... Distribution cylinder, 4... Pump and distribution piston, 6...
- Radial passage, 7... Load reduction passage, 8... Piston end face, 9... Pump working chamber, 10... Ring slider, 11... Notch, 12... Piston ring, 14 ...Annular groove, 15...Load reduction hole, 16...
・Compensation chamber, 17... Adjustment chamber, 18... Pressure spring, 1
9... Stone ξ, 20... Aperture point, 22...
Fuel supply pump, 23... Fuel container, 24... Fuel supply conduit, 25... Check valve, 26... Backflow conduit, 2
7... Pressure regulator, 28... Passage, 29... Longitudinal groove, 30... Distribution groove, 31... Distribution passage, 33
... Adjustment conduit, 34 ... Adjustment generator, 35 ... Control device, 36 ... Accelerator device, 37 ... Axial position, 38 ... Stroke position signal transmitting device, 41 ... Stone ξ, 42.43... Aperture member, 44... End face,
45...Circumferential groove, 46...Aperture cross section, n...
Number of revolutions

Claims (1)

[Scope of Claims] l. A fuel injection pump for an internal combustion engine, comprising a supply amount metering member, wherein an outer peripheral portion of the supply amount metering member slides within a notch against a return force. The supply metering member controls the suction chamber in which a predetermined fuel pressure is generated.
By separating it from the regulating chamber in which the fuel pressure is generated, which can be varied via a regulating pressure generator which is electrically controlled in dependence on the operating characteristic values, the position of the feed metering element can be adjusted depending on the operating characteristic values of the internal combustion engine. In the type as defined, the suction chamber (16) of the feed metering member
and the regulating chamber (17) are connected to each other via a throttling point (20, 46).
4), a ring slider (10) is used which is slidably arranged on the piston end face (8), said pump and distribution piston (4) projecting into the pump working chamber (9).
a load relief passage (7) starting from the load relief passage (7), which load relief passage (7) is provided with a radial passage (6) extending radially towards the outer circumference;
2. Fuel injection pump according to claim 1, wherein the cross section of the ring slider (1o) is controlled to a greater or lesser extent by the ring slider (1o). 3. A pressure spring (18) supported by a ring slider (1o) is disposed in the adjustment chamber (17), and this pressure spring (1δ) causes the ring slider (18) to move when the fuel injection pump is not in operation. 10) towards the straight e (19), in which position the ring slider (1o) maximizes the opening of the radial passage (6) of the pump and distribution piston (4). It is supposed to be open,
The fuel injection pump according to claim 2, 4. When the internal combustion engine is started, the fuel injection pump (2
) supplies fuel to the suction chamber (16), the regulating chamber (17) being offloaded with respect to the suction side of the fuel supply pump by means of a regulating pressure generator (34). The fuel injection pump according to item 3. 5. A pressure spring (18) supported by the ring slider (10) is disposed in the suction chamber (16), and this pressure spring (18) moves the ring slider (18) when the fuel injection pump is not in operation. 10) into a position abutting the stop (41) such that in this position said suction slide/(10) at least partially closes the opening of the radial passage in the pump and distribution piston (4). 6. When the internal combustion engine is started, the fuel supply pump (
22) supplies fuel into the suction chamber (16), which serves as the pump working chamber (Q) and the load relief passage (7).
and through the radial passage (6°45) the regulating chamber (17)
The reverse flow conduit (3
6. Fuel injection pump according to claim 5, wherein the regulating pressure generator (34) of 3) is closed from the regulating chamber (17) to the suction side of the fuel supply pump. 7. The fuel injection pump (22) supplies fuel to the suction chamber (16) and the regulating chamber (17) via the regulating pressure generator (34).
), and when the fuel flows backward through the throttle member (42), the fuel pressure in the suction chamber (16) is lowered relative to the suction side of the fuel supply pump (22). The fuel injection pump according to claim 5, wherein the fuel injection pump is 8. The ring slider (1o) has an annular groove that opens toward the pump and distribution piston (4) (overlapping the suction chamber (
16), the fuel injection pump 9 according to claim 4 is adapted to reduce the load on the fuel injection pump 9, in which the throttle point (20) connecting the adjustment chamber (17) to the suction chamber (16) is a ring. 9. Fuel injection pump according to claim 8, which is arranged in the slider (1o). 10. Fuel injection pump according to claim 4, wherein the opening of the radial passage (6) is more or less closed off to the regulating chamber (17) by a ring slide (10). 11. A radial passage (
Claim 10, in which the opening of 6) is used.
Fuel injection pump as described in section. 12. The fuel injection pump according to claim 1, wherein a periodically controllable solenoid valve is used as the regulating pressure generator (34).