CN1030280A

CN1030280A - Be used for the particularly jerk pump of marine diesel engine of internal-combustion engine

Info

Publication number: CN1030280A
Application number: CN88103934A
Authority: CN
Inventors: 芬·夸德鲁普·詹森; 维戈·詹森; 詹斯·布卢姆·拉森; 约翰内斯·弗莱鲁普
Original assignee: MAN B&W Diesel AS
Current assignee: MAN B&W Diesel GmbH; MAN B&W Diesel AS
Priority date: 1987-06-25
Filing date: 1988-06-23
Publication date: 1989-01-11
Also published as: DK323787D0; DK323787A; JPS6435074A; KR890000780A

Abstract

Be provided with a pressure-relief valve in the high voltage terminal of fuel oil injectionpump and the connecting duct between the low voltage terminal, this pressure-relief valve is cutting out towards the low voltage terminal direction, and it has one to have a static valve seat and a movable valve body.One driven plunger one end matches with valve body and its other end is connected with a pressure source.Make valve body towards being centered around between driven plunger and the valve body that the direction of lifting off a seat drives than soft spring.Driven plunger by pressure controlled displacement effect under, valve body is pushed away valve seat, so that make the high voltage terminal of pump and low voltage terminal be connected to form the fuel-injected instantaneous interruption.This can shorten the transient time of engine start.

Description

Be used for the particularly jerk pump of marine diesel engine of internal-combustion engine

The present invention relates to a kind of jerk pump that is used for the particularly marine diesel engine of internal-combustion engine.

The starting process of known big marine diesel engine at first is to be that so-called starting air is supplied in each Indivudual cylinder with pressurized air, so that bent axle is rotated under certain initial revolution, the injection of fuel oil has just been interrupted and begun in the supply of air subsequently.

When above-mentioned initial air supply, each single fuel oil injectionpump all is adjusted on zero indicating graduation, thereby there is not the pressure fuel delivery to come out, these pumps will be adjusted to always and just carry fuel oil when the moment that starting air stops to supply with, this is because starting air and fuel oil can not be supplied to cylinder simultaneously, to avoid the danger of blast.Above-mentioned adjustment is by realizing that with the joining machinery of the camshaft of pump/pneumatic system this system generally is that the pull rod coupling of displacement constitutes because spring promotes by many.According to the complexity of this system and the weight of size and associated components, therefore in this adjust system, there is certain inertia, this system also just has an intrinsic reaction time like this.

And a kind of like this reaction time or time lag are undesirable because it delayed from the supply starting air until fuel injection is seted out the actual whole job order of motivation total computing time.This problem is very important under the situation of so-called " stopping suddenly ", and the motion of steamer is stopped as quickly as possible.In fact, above-mentioned situation has only by the antiport of motor and just can realize, even engine cut-off and pilot engine immediately it is rotated in the opposite direction.

It seems with practical conditions, the power that reacts on the propeller owing to water under this condition is " bearing " with respect to desired starting direction, this motor will be subjected to the effect of a driving torque, obviously to reduce the stop supplies starting air to the time cycle of beginning between the injected fuel be very important, because driving torque negative in this time cycle is braked the rotation of motor, also just increased the risk of engine start failure thus.

Normal engine cut-off is to interrupt the supplying fuel of fuel pump is realized by above-mentioned machinery/pneumatic system, and the stopping in emergency of connection that link to each other with top described " stop suddenly " situation is by starting a direct-connected cylinder that works independently of the camshaft with fuel pump, the fuel delivery of realization interruption pump thus.Like this, between above-mentioned two kinds of situations, there is no the principle difference, both purposes all are that the amount of wishing to be supplied to the fuel oil of each pump was adjusted on zero point, and the both is that this just means that the total inertia of relevant machinery/pneumatic system will be overcome owing to the connection between camshaft and adjust system remaining part.

According to fuel oil injectionpump of the present invention is different with the fuel pump of existing the above-mentioned type, in this fuel oil injectionpump, by disposing a static valve seat and the one-way valve form that movable valve body is formed, and be that the pressure-relief valve of cutting out is arranged in the high voltage terminal and the connecting pipeline between the low voltage terminal of this pump towards the low voltage terminal direction, and wherein this pressure-relief valve comprise one movable, the driven plunger that is suitable for the work that matches with valve body of air-operated control preferably is in order to drive this valve body leaving on the direction of this valve seat.

Utilize a kind of like this pressure-relief valve just can be so that the needed time of the starting of motor and parking shortens.

This is owing to utilize this pressure-relief valve that the low voltage terminal of fuel pump and high voltage terminal are coupled together the result who is produced, and prevents to carry out the required voltage rise of fuel injection thus.When engine start, this pressure-relief valve one is opened, and this just means can realize the desired adjustment of fuel pump, and does not carry out the fuel injection of any reality.The fuel oil of being supplied with by fuel oil injectionpump only carries out recirculation through pressure-relief valve to oil-fired system low voltage terminal.

If pressure-relief valve all is to control by following mode now, be to open a period of time earlier before pressure-relief valve was finished in the starting air cycle, just can make adjust the required time of fuel pump just in the starting air periodic regime rather than the situation before resembling in its back, and the shut-in time the earliest of this pressure-relief valve must be with the generation of finishing in starting air cycle, and do like this is useful, and at this moment each pump all is ready to supply with required amount of fuel simultaneously.Just closing of this pressure-relief valve only comprises that its relevant little valve body moves a short distance, and time lag in this respect is negligible.Therefore, should admit, can make in the transient period of utilizing the compressed air-driven motor and utilize fuel oil to drive between the motor according to fuel oil injectionpump of the present invention to obtain sizable shortening.

For example can with pressure-relief valve open with the driving of regulating system and the elapsed time in starting air cycle coincides and as mentioned above, the deadline of pressure-relief valve shut-in time with the starting air cycle overlapped, so just can obtain and control relevant various benefits.

Time required during about above-mentioned engine cut-off shortens, and this equally also is the direct result that is produced owing to the high voltage terminal " release " at fuel oil injectionpump.

Parking is to interrupt rapidly realizing by the supplying fuel to each cylinder.Up to the present this process all is by fuel oil injectionpump being adjusted to the zero graduation indication, realizing by machinery/pneumatic regulating system or by the working cylinder that is directly installed on the pump no matter be.As mentioned above, the above-mentioned inertia that either way must overcome total regulating system will bring the regular hour to postpone thus inevitably.

By driving this pressure-relief valve, the high voltage terminal of fuel oil injectionpump is with regard to release soon, thereby the needed voltage rise of injected fuel has subsequently just no longer taken place.Because the valve body of pressure-relief valve is not connected with other mechanical component, thereby just can not bring the time lag relevant with inertia, with to interrupt time difference between the injection be that inertia by corresponding regulating system is little shortened in the reaction time stopping by instruction.

In a most preferred embodiment, this parking is pressed on the direction of leaving this valve seat by spring.

It is particularly advantageous that this embodiment combines with fuel oil injectionpump, wherein the piston of this pump itself must help the so-called suction valve effect by an one-way valve form in its return stroke, and the amount of being aspirated is sprays required amount of fuel subsequently.When realizing above-mentioned suction, this pressure-relief valve in fact also can be used as a suction valve, thereby it is unnecessary that an independent suction valve is become.

Below in conjunction with accompanying drawing the present invention is explained in more detail, wherein:

Fig. 1 is the vertical cut-away view that the part along fuel oil injectionpump of the present invention cuts;

Fig. 2 is an enlarged view of pressure-relief valve shown in Figure 1;

Fig. 3 is a replacement type of pressure-relief valve shown in Figure 2.

The fuel oil injectionpump 1 that partly demonstrates in Fig. 1 comprises a pump case 2, and the pump cylinder 3 of one of them belt material cover 4 axially can carry out displacement as axle journal.An annular suction chamber 5 of accepting low pressure (8 to 10 crust) fuel oil by a unshowned import is set between this cylinder body 3 and housing 2.

The upper end face of pump case 2 is being fixed a top cover 6 in Fig. 1, and this top cover has a central hole 7 at its end surface facing to pump case 3, and this central hole is connected on the relevant fuel injector by

conduit

8 and 9, but not shown.

This central hole 7 accommodates the lining 12 of a band center conduit section 13, and the conduit 8 in this run 13 and the top cover 6 aligns.Lining 12 is felt relieved with a hollow core valve housing 14 that is fixedly mounted in the hole 7 by and is fixed, and is slidingly fitted in the hole of the lower end of this valve chest and axially displaceable cylinder liner 4.

The valve body 15 that can move in valve chest 14 is to utilize a spring 16 to compress facing to a static valve seat 17 in valve chest 14.Above-mentioned valve opens and closes in known manner through overflow conduit 18 in pump cylinder 3 and lining 4 thereof and 19 and suction chamber 5 and formed connection the between the pump chamber 22 that bush inside limited.

Pump chamber 22 be downwards by one in lining 4 axially displaceable pump piston 23 limited, and this pump piston stretches out by the lower end of this housing in known manner and the work that matches with a cam that rotates synchronously with engine crankshaft.

The upper end of the pump piston 23 in Fig. 1 is provided with two sealing surfaces 24(that are separated from each other in known manner wherein to be had only one and can see in Fig. 1) this surface is adjacent to securely to the madial wall of lining 4.The sealing surface is to limit by a straight sharp edge 25 at its top, and be by limiting with the sharp hypotenuse 26 of overflow hole 27 cooperatings that in lining 4 and cylinder body 3, align in its bottom, so that open and close and to dispose above-mentioned hole 27, and hole 27 makes between pump chamber 22 and the suction chamber 5 and is connected.

Pump piston 23 is axially to be connected with the sleeve of a outer toothed below pump cylinder 3 in known manner movablely, and this socket teeth is to be meshed in order to the tooth bar of adjusting the effective travel volume of this pump by the rotation of piston with one.

The bottom of this pump cylinder 3 has an outside thread equally in known manner, and this male thread portion is meshed with a corresponding internal thread of swing nut in the outer toothed of axial restraint.And the external tooth on this nut is meshed with a tooth bar so that make it can pass to pump cylinder 3 by the displacement of this tooth bar and lining 4 makes its axial displacement, changes fuel-injected moment thus.

When pump piston 23 when working stroke begins to move upward, it is blocked that the overflow hole 27 in lining 4 all passes through sealing surfaces 24, and the pressure in the fuel oil volumes that limited in the pump chamber 22 is risen, and causes

suction valve

15,17 to be closed thus.Therefore, fuel is just by valve body 15, hollow core valve housing 14, lining 12 closely question male ridge cyperus malaccensis 3 and upwards the

run

8 and 9 by top cover 6 arrive real fuel injector, the nozzle opening by this sparger is injected into cylinder under high pressure (about 800 crust).

To top offset after a little, this inclination sharp edge 26 is through overflow holes 27 at pump piston 23, causes then thus that moment, pressure drop took place owing to be connected with suction chamber 5 in pump chamber 22 and relevant conduit and pipe-line system, along with this pressure drop is then just sprayed and interrupted.

After pump piston 23 is being finished the work stroke, move downward immediately, at this moment the pressure in the pump chamber 22 equals the pressure in the suction chamber 5 substantially.So just causing that

suction valve

15,17 is opened so that spray needed amount of fuel subsequently can be flowed in the pump chambers 22 through

conduits

18 and 19 by suction chamber 5.Above-mentioned then work cycle repeats again.

As seen from Figure 1, overflow of the upper end of top cover 6 configuration or pressure-relief valve 30.This valve comprises center conduit 31 these conduits 31 that are connected with high-pressure conduit 8 in top cover 6 and is connected with a doughnut that forms on top cover 33 by the transverse conduit 32 that tilts, and this doughnut is connected with the return terminal of oil-fired system by a pipe joint 34, and is connected with suction chamber 5 by a unshowned pipe joint.

Pressure-relief valve 30 by a up-sizing among Fig. 2 is expressed, and this center conduit 31 accommodates a coniform valve base 35, this valve seat with one by the work that matches facing to the spring 37 movable valve body 36 that drives of this valve seat direction.Opposite one side at the valve body 36 of valve seat 35 is provided with a driven plunger 41 consistent with this valve body direction of displacement in hole 40.One end and the valve body of above-mentioned driven plunger connect, and drive this valve body towards the direction displacement of lifting off a seat.The other end of this driven plunger 41 is to seal the flow direction that its end surface 44 is connected perpendicular to pressured fluid import 45 by 42 pairs of housings 43 of a seal ring.Driven plunger 41 seals by 47 pairs of holes 40 of two Sealings.Be interconnected between above-mentioned two Sealings in hole 40 with as detecting and can discharge two

conduits

49 and 50 that possible leakage of oil is flow through through packing ring 47, arrive 46 places, space to prevent fuel oil.The outside of housing utilizes 52 pairs of top covers 6 of two " 0 " type circles to seal.In addition, be connected with atmosphere by a unshowned breather line with space 46 between the housing 43 in driven plunger 41.

Under the normal operation of motor, this pressure-relief valve cuts out, because valve body 36 is pressed on the valve seat 35 with its seal face 53, this part that compresses is because the effect of spring 37, and another part is because the effect of oil pressure in the conduit 8.

Motor stops as soon as possible if desired, the unexpected parking situation of for example being mentioned in front, and then pressured fluid just leads to pipe joint 45 by a not shown fluid supply.Just can be used as pressure source effectively by motor as the next pressurized air of the air vessel of starting.Above-mentioned air just promotes driven plunger towards the direction displacement of the right shown in Fig. 2, so also overcomes the active force of spring 37 and lifts off a seat 35 with regard to promoting valve body 36.Thereby the high voltage terminal of pumps forms with low voltage terminal in the conduit 32 and is communicated with in the conduit 8, and this just causes moment pressure drop of high voltage terminal generation.Above-mentioned release just causes to the required fuel oil voltage rise of oil spout subsequently and can not carry out.

Above-mentioned overflow just need pressure-relief valve part finding displacement and do not relate to and pump itself and the relevant member of adjust system thereof.Therefore should admit that the engine cut-off that provides according to fuel oil injectionpump of the present invention is very rapid, and be to accomplish safe and reliable by simple device.

When engine start, no matter be starting immediately or normal starting after stopping suddenly, because the end surface 44 of driven plunger 41 is to keep ventilation, so this valve is to stay open state.After this driven plunger one ventilation, fuel oil injectionpump just can place on the starting indicating graduation.

When motor rotates by supplying with starting air, do not eject but by the low voltage terminal recirculation of pressure-relief valve to this system by sparger by the amount of fuel of pump transmission.This driven plunger just communicates with atmosphere immediately when starting air is supplied with interruption, and this valve just cuts out thereupon.See that with practical conditions all adjusted is to starting indicating graduation as mentioned above for each independent pump, so then motor is just prepared without any need for further adjustment or delay for injected fuel immediately.

Fig. 3 represents a replacement type of pressure-relief valve shown in Figure 2.The pressure-relief valve of this embodiment is the same with the former to be comprised in this housing, has a coniform valve base 62 that matches with movable valve body 63 by a valve chest 60 that has center conduit 61.This valve body comprises a valve disc 64 and a valve rod that stretches out by a hole 66 65 on the low voltage terminal of valve seat 62, this valve rod matches with a driven plunger 67 that nestles up housing.Above-mentioned driven plunger be by a bigger cylindrical shell and one within it portion be provided with the pin part 68 that central authorities stretch out and constituted, this pin part is docked connection with the end face of valve rod.Be docked near on the lock washer 71 on the valve rod end, and to be biased in the soft spring 70 that they are separated from each other out be to be centered around on this pin part.Should be appreciated that this driving represents that valve disc 64 is in the driving situation of lifting off a seat at 62 o'clock.

So just can draw this pressure-relief valve and also can be used as above-mentioned suction valve, thereby it is unnecessary that this suction valve is become.

The function of the embodiment of this pressure-relief valve is as follows: north is not encouraged 3 and is in and returns or during intake stroke, then pressure-relief valve will be opened, be effect on the one hand, and be on the other hand because the influence that the pressure that takes place in pump chamber 22 and conduit 8 falls owing to spring 70.Therefore, fuel oil can freely flow in the pump chamber 22 by conduit 32.

When pump piston is in subsequently working stroke, the fuel oil voltage rise of being held in pump chamber 22 that volume causes will cause valve disc 64 to compress and this valve cuts out facing to valve seat 62, and then aforesaid continuous pressure will take place rise and fuel injection.

The embodiment of this pressure-relief valve comprises as above-mentioned and detects and discharge the conduit 73 that may sew fuel oil and is connected the airway 74 that the back of following driven plunger 67 is connected with atmosphere with one.

Claims

1, a kind of internal-combustion engine that is used for, being described more specifically is the jerk pump (1) that is used for marine diesel engine, it is characterized in that: it disposes an a kind of static valve seat (35) and a movable valve body (36), be arranged on the high voltage terminal and the connecting duct between the low voltage terminal (8 of pump with the pressure-relief valve (30) of one-way valve form, 31) in, and on the direction of low voltage terminal, be to close, and wherein this pressure-relief valve comprises a movable preferably air-operated control, be suitable for the driven plunger (41) with valve body (36) cooperating, in order to drive of the direction displacement of this valve body towards lift off a seat (35).

2, pump as claimed in claim 1 is characterized in that: described valve body (36) on the direction of valve seat (35) by spring compression.

3, pump as claimed in claim 1 is characterized in that: described valve body (63) on the direction of lift off a seat (62) by spring compression.