DE1526516A1 - Device for supplying liquid fuel to an internal combustion engine - Google Patents

Description

G.A, V. Limited November 7, 1966

London / England

Device for supplying liquid fuel to an internal combustion engine

The invention relates to a device for 'supplying liquid fuel to internal combustion engines that have an injection pump, a pressure medium-actuated actuator for setting the point in time of the injection and an adjustable one Throttle element for regulating the amount of fuel supplied to the internal combustion engine to v / eist.

The invention is based on the object of a device to prepare this known design in a structurally simple manner so that the setting of the pressure medium-actuated Actuator is a function of the setting of the throttle element determining the power of the internal combustion engine. Fuel systems of this type are known per se. However, the known systems are relatively expensive to build and also do not lead to satisfactory results. The invention therefore aims to use the known fuel systems to improve this type in terms of their design and puncture ability.

According to the invention, in the flow path regulated by the throttle element, lies behind the throttle element in the direction of flow a throttle point is the pressure at a point lying between the throttle element and this throttle point

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transferred to the pressure medium-actuated actuator, such that changes in the setting of the throttle member a change in pressure at this point and accordingly a change the setting of the pressure-actuated actuator and hence the IC injection timing.

Preferably, the throttle member is in one of the discharge flow path connected to a feed pump. The Auslai, .- pressure the feed pump is dependent on the speed of the internal combustion engine.

Canoe between the outlet of the feed pump and the throttle body be arranged according to another feature of the invention, a further throttle point, wherein a valve is provided, which the pressure between this "restrictor and ilern Throttle body to an ir ;, substantially constant pressure value holds.

The pressure medium-actuated actuator can on the one hand from the outlet pressure of the feed pump and on the other hand from the pressure be applied to the said point, the pressures in the sense of an adjustment of the actuator in opposite directions Direction act on the actuator. The actuating element actuated by pressure medium is preferably against the force of a spring adjustable, which expediently acts on the actuator in the opposite direction to the outlet pressure of the feed pump.

To change the timing of fuel injection Depending on the setting of the throttle element, a device can also be used in which, according to the invention the feed pump feeds the fuel to the flow path the throttle organ promotes and in a branch line of the flow channel between the feed pump and the throttle element there is a valve with a constant pressure drop. There is also a

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by centrifugal action ;; Actuated control valve downstream of this valve in flow direction with constant pressure drop arranged which the. The pressure behind this valve is regulated in such a way that it is a function of the drive speed of the controller changes, with the Dumhflussweg behind the throttle point at a point behind the valve with constant Pressure drop is closed on.

Further Ilerkniale of the egg ¹ invention emerge from the following description of the embodiments of the invention shown in the drawing and are listed in the individual claims. In the drawing shows:

Fi £. 1 shows a fuel pump according to the invention in

Cut;

Fig. 2 is a partial view of the fuel pump according to

Fig. 1 in cross section;

J to 6 schematically different exemplary embodiments

of the fuel circuit of the fuel system according to the invention.

The fuel pump shown in the drawing has a housing Io in which a rotating distributor 11 is mounted is. At one end of the manifold a transverse bore is arranged in which a pair of reciprocating plungers 12 is located at the rotation of the distributor under the action of a Uockenringes 13 to carry out the Pump delivery stroke can be pushed into the transverse bore. The distributor is provided with a longitudinal bore 14 to which a number of radially extending inlet channels 15 and a single radial delivery channel 4o are connected. The inlet ducts are arranged in such a way that they

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during which the pistons 12 can move outwardly, successively overlap with the inlet port 16. During the inward stroke of the piston, the feed channel Ho comes with einetr. of several Auslaßkanäleri Hl in connection, which are each connected to a combustion chamber of the internal combustion engine. During the outward movement of the pistons 12, the fuel flows from the inlet opening 16 to the pump chamber located between the pistons 12. During the inward movement of the pistons 12, on the other hand, the fuel is pushed out of the pump chamber and fed to one of the combustion chambers of the internal combustion engine.

The fuel is supplied by a feed pump 17 of the vane type, the rotating part of which is mounted on the distributor, the Inlet opening 16 supplied, it flows via the channel 18 in the housing to one end of a radially arranged cylinder 19 »which is also in the housing. In this cylinder there is an axially movable throttle element 2o, which is provided with a pair of circumferential grooves spaced apart from one another in the axial direction. The lower groove stands via a duct located in the throttle element with the cylinder 19 and accordingly with the outlet of the feed pump 17 in connection, in the wall of the cylinder 19 opens a channel 21 which is in communication with the inlet opening 16. By changing the axial setting of the throttle element, the opening of the channel 21 is set. In this way the amount of fuel delivered by the fuel pump can be regulated.

The outlet pressure of the feed pump 17 is controlled by a spring-loaded Overflow valve 22 regulated; the amount of fuel delivered by the feed pump is proportional to its speed and significantly greater than the amount of fuel that the

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Internal combustion engine is supplied. The AuslaiSdruck der 'The feed pump changes depending on the speed This pressure acts on one end of the throttle valve ^ ans 2o and moves this against the action of a helical spring 2j5 in the sense of a reduction in the opening cross section of the Channels 21. The spring and the throttle organ v.'ii'icen denigeinäij like a hydraulic reeler, the speed of the internal combustion engine regulates.

In order to adjust the point in time of the injection, the cam ring 13 can be adjusted in angle about the axis of rotation of the distributor. For this purpose, a pressure-actuated actuator is provided in the form of an actuating piston 24, which is movable in a cylinder arranged tangentially to the squat ring (Fig. 2). One end of the cylinder is over a check valve 25 connected to the channel l8 while in the cylinder chamber on the opposite side of the piston there is a helical compression spring 26. The arrangement is taken so that the actuating piston 24 with increasing outlet pressure the feed pump is adjusted against the action of the spring and the time of the injection is adjusted accordingly the speed of the prime mover changes.

The pressure in the cylinder chamber receiving the spring 26 is also variable. For this purpose, this cylinder side is connected via a channel 42 to a DurehlaJkanal 27 which is formed in the wall of the cylinder receiving the throttle element 2o. The cross-sectional size of the passage 27 changes depending on the setting of the throttle member. The fuel flows to the upper groove of the throttle element from channel 18 via an interposed throttle point 28. The pressure of the fuel supplied to this groove is controlled by a valve 29 with a constant pressure setting. Furthermore, a throttle point J> o is arranged in the actuating piston 24, which throttle point connects the cylinder side receiving the spring 26 to an outlet. In operation, the throttle member 2o is moved so that it

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changes in the Del as time: counteracts 1er internal combustion engine, wherein the ^f viiörschnittsgrüße of Durchlaßkanales 27 so changes that the pressure on the 26 receiving Zylinderneite changing the spring. In the special AusfUhrungsform the arrangement is such that, if the speed remains constant and the load increases, the throttle element moves 2.B downward, the pressure on the cylinder side receiving the spring 26 increases and the actuating piston 24 to the right is moved.

The task of the check valve 25 is to prevent that the reaction force of the pistons running up against the cams of the cam ring displaces the cam ring. In this Case closes the check valve and thereby blocks the outflow of fuel from the spring 26 opposite Side of the cylinder.

In the arrangement according to FIG. Ρ, the throttle points 28 and J) O are arranged in the throttle element or in the housing of the pump. The AuslaSdruck the pump does not act directly on the actuating piston 24, as in the embodiment according to FIGS. 1 and 2 the case is to move the piston GGEN adjust the effect of its spring zn. The channel 42 is, however, connected to the end of the cylinder opposite the spring, and the position of the channel 27 is changed so that the cross-sectional size of the channel 27 is reduced when the throttle element moves downwards with an increase in the amount of fuel supplied. The piston 24 moves in the same direction, but is not dependent on changes in the speed of the internal combustion engine.

In the embodiment according to FIG. 4, the measuring valve is provided with a single piston attachment to which the fuel

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flows in directly from the channel 18. The axial setting of the measuring valve determines the cross-sectional opening of the channel 21, as is the case with the embodiments provided is the case, and also the cross-sectional size of the channel 31 The channel 31 is at that end dec the injection time adjusting actuator cylinder that is activated on the side opposite the spring. Further a throttle point 32 is provided through which a between the channel 31 and the cylinder receiving the actuating piston 2'4 is connected to a drain. In this embodiment, the setting of the piston is dependent both the speed and the load on the internal combustion engine.

In the mitigated embodiment according to Flg. 5, the feed pump 17 conveys the fuel under pressure to the attachment of the throttle element 2o. The cross-sectional size of the passage 21 changes the amount of fuel delivered to the internal combustion engine in accordance with the embodiments described above. In addition, this arrangement has a constant pressure valve 32 which is connected to the outlet of the feed pump and through which the fuel passes under pressure so that it acts on the throttle element in the opposite direction to the action of the spring 23. The fuel pressure acting on the throttle element is regulated by a centrifugal regulator 33, which is mounted in the distributor 11 of the pump and regulates the pressure through the fuel outlet proportionally to the square of the speed at which the distributor rotates. Furthermore, a channel Jk is provided, the opening cross section of which is controlled by the throttle element and which is connected to the end of the cylinder receiving the actuating piston 2h. A point between the channel 3 ^ and this cylinder is connected via a throttle point 35 to a point lying between the centrifugal regulator 33 and the cylinder 19. in the

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In operation, the pressure on the outlet side of the feed pump is regulated to a pressure which corresponds to the regulating pressure of the centrifugal regulator plus the pressure drop across the valve 32 at constant pressure. This pressure acts on the actuating piston 24 and is controlled by the cross-sectional size of the orifice 34. It is therefore always between the outlet pressure of the feed pump and a lower pressure value determined by the setting of the valve with the constant pressure. This pressure is dependent on both the speed of the internal combustion engine and on the setting dec throttle body. In this way, the setting of the actuating piston 24 is dependent on the speed and the load on the internal combustion engine.

The embodiment shown in FIG. 6 corresponds in principle to the embodiment shown in FIG. 5, however with the exception that the fuel taken up by the internal combustion engine is here at a constant rate through valve 32 Pressure flows and its pressure is controlled by the centrifugal regulator 33.

Patent claims:

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Claims (7)

Claims Device for supplying liquid power t.iüoff zu einor Internal combustion engine, which has an injection pump, a druckruit.v-elbetätiges Setting element for setting the point in time the injection and an adjustable throttle element for regulation the amount of fuel discharged from the internal combustion engine having, characterized in that in learning of the throttle member (2o) regulated flow path in flow direction behind the throttle body (2o) is a throttle roller and the pressure at a point between the throttle element and this throttle point on the pressure valve operated Actuator (24) acts so that changes in the setting of the throttle member (2o) a change in pressure at this point and accordingly a change in the setting of the cause pressure medium-actuated actuator (24) and consequently the injection time. 2. Apparatus according to claim 1, characterized in that the Throttle body (2o) in one at the outlet of a 3paisepunipe (17) connected flow path, the outlet pressure depends on the speed of the internal combustion engine changes. 3. Apparatus according to claim 2, characterized in that between the outlet of the feed pump (17) and the throttle element (2o) a further throttle point (28) is located, and that a valve (29) is provided, which hisses the pressure y /, this throttle point (28) and the throttle element (.ίο) on one holds essentially constant value. - Io 9Q9842 / 068t 4, device according to claim 3> thereby gei.onnzelonnet that the pressure medium-actuated actuator (24) on the one hand from the outlet pressure of the feed pump (17) * on the other hand from the pressure is acted upon at the point mentioned, the bridge in the sense of an adjustment of the actuator (24) in the opposite direction Act direction. 5. Device according to one of claims 1 to 4, characterized in that that the pressure medium-operated actuator (24) can be adjusted against the force of a peder (26). 6. Apparatus according to claim 5 * characterized in that the Spring force acts on the actuator (24) in the opposite direction to the release pressure from the feed pump (17). 7. The device according to claim 1, characterized in that the feed pump (17) feeds the fuel to the flow path / or the Throttle member (2o) promotes and in a branch line of the Durchflußkarials between the feed pump (17) and unci dew throttle member (2o) there is a valve (32) with a constant pressure drop, that furthermore one actuated by Zen tr ifuga.lv/irkung Control valve (33) downstream of this valve in the direction of flow (32) with constant pressure drop, the pressure is increased controls downstream of this valve in such a way that it changes as a function of the drive speed of the controller, the flow path downstream of the throttle point is connected to a point downstream of the valve (32) with a constant pressure drop. 8, device according to claim 7, characterized in that there; » Throttle device (2o) from the pressure behind the valve (32} ~ it constant pressure drop is applied and from this ;; against - 11 - 909842/0681 BATH the effect of a regulator spring (2j) is adjustable so that as a result, the amount of fuel fed to the internal combustion engine is changed. Q. Apparatus according to claim 3, characterized in that the injection pump receives the fuel supplied from an otclle which is downstream in the direction of flow. Valve {yd) is with constant pressure drop. 909842/0681