HRP920926A2

HRP920926A2 - Injection pump for an internal combustion engine comprising a mechanism for controlling the start of the final injection delivery

Info

Publication number: HRP920926A2
Application number: HR920926A
Authority: HR
Inventors: Dirk Bastenhof
Original assignee: Semt
Priority date: 1981-04-16
Filing date: 1992-10-02
Publication date: 1995-10-31

Description

Područje tehnike The field of technology

Izum je iz područja motora s unutarnjim sagorijevanjem, a posebno se odnosi na crpku za ubrizgavanje goriva, sa uređajem za podešavanje trenutka potiska goriva. Prema međunarodnoj patentnoj klasifikaciji izumu pripada oznaka The invention is from the field of internal combustion engines, and in particular relates to a fuel injection pump, with a device for adjusting the moment of fuel thrust. According to the international patent classification, the designation belongs to the invention

Tehnički problem Technical problem

Tehnički problem koji se rješava ovim izumom je sljedeći: The technical problem solved by this invention is the following:

Kako konstrukciji riješiti uređaj za podešavanje trenutka potiska goriva iz crpke za ubrizgavanje u mlaznicu u funkciji promjenjivih parametara, tako da se osigura siguran rad crpke i široki obujam regulacije. How to design a device for adjusting the moment of fuel thrust from the injection pump to the nozzle as a function of variable parameters, so as to ensure safe operation of the pump and a wide range of regulation.

Stanje tehnike State of the art

Poznate su crpke za ubrizgavanje za motore s unutarnjim sagorijevanjem (EP-A-0 020 249), sa uređajem za podešavanje trenutka potiskivanja goriva prema mlaznici. Ovaj uređaj obuhvaća komoru za akumulaciju određene količine potisnutog goriva nakon zatvaranja usisnih otvora. Klip postavljen u toj komori se povlači u ovisnosti o kretanju klipa crpke, kako se u komori ne bi stvorio nadpritisak dovoljan za otvaranje izlaznog ventila crpke. Otvaranje izlaznog ventila nastaje kada klip akumulatora dostigne svoj ekstremni položaj. Da bi trenutak potiskivanja bilo moguće podešavati, potrebno je da ekstremni položaj klipa bude varijabilan. Injection pumps for internal combustion engines (EP-A-0 020 249) are known, with a device for adjusting the moment of pushing the fuel towards the nozzle. This device includes a chamber for the accumulation of a certain amount of pressurized fuel after closing the intake ports. The piston placed in that chamber is withdrawn depending on the movement of the pump piston, so that no overpressure is created in the chamber sufficient to open the outlet valve of the pump. The outlet valve opens when the accumulator piston reaches its extreme position. To be able to adjust the pushing moment, it is necessary that the extreme position of the piston is variable.

Ovaj uređaj za podešavanje je kompleksan i glomazan. Složenost se još više uvećava kada je potrebno osigurati podešavanje u funkciji nekih parametara motora. This adjustment device is complex and bulky. The complexity increases even more when it is necessary to provide adjustment as a function of some engine parameters.

Opis rješenja tehničkog problema Description of the solution to the technical problem

Crpka za ubrizgavanje prema izumu obuhvaća uređaj za podešavanje s ventilom za otvaranje goriva, kao i upravljački sustav za zatvaranje ventila u funkciji kutnog položaja motora (klipnjače). The injection pump according to the invention includes an adjustment device with a fuel opening valve, as well as a control system for closing the valve as a function of the angular position of the engine (piston rod).

Jedna od prednosti izuma je daje upravljanje ventilima tako podešeno da je otvaranje ventila definirano podpritiskom u usisnoj komori ostvarenim prilikom povratnog hoda klipa na donjoj mrtvoj točki. One of the advantages of the invention is that the valve management is adjusted in such a way that the opening of the valve is defined by the underpressure in the suction chamber created during the return stroke of the piston at the bottom dead center.

Također je prednost novog rješenja u tome, što upravljanje ventilima obuhvaća komandno hidraulično kolo sa elektro-ventilom, pri čemu je strujno kolo vezano sa senzorom kutnog položaja motora i, za slučaj potrebe, elementom za kašnjenje u funkciji rada motora, postavljenim u kolo signale senzora. Another advantage of the new solution is that the control of the valves includes a hydraulic control circuit with an electro-valve, where the current circuit is connected to the sensor of the angular position of the engine and, if necessary, an element for the delay in the function of the engine operation, placed in the circuit of the sensor signals .

Jedina slika u prilogu prikazuje presjek crpke za ubrizgavanje prema izumu, sa shematskim prikazom upravljačkog sustava za podešavanje. The only attached figure shows a cross-section of the injection pump according to the invention, with a schematic representation of the control system for adjustment.

Prikazana crpka za ubrizgavanje obuhvaća cilindrično kućište 1 u kome se aksijalno kreće klip 2 čija glava ima helikoidalni rub 3. Klip 2 se povratno kreće između G.M.T. (gornje mrtve točke) i D.M.T. (donje mrtve točke). Usisna komora 5 je ograničena kućištem 1 i dijelom 4 klipa 2. Napajanje komore 5 gorivom se vrši preko otvora 6 u zidovima kućišta 1 u blizini donje mrtve točke (D.M.T.), tako da ih klip u svom ulaznom hodu zatvara. Pozivnom oznakom 7 je kao cjelina označen element za pražnjenje, predviđen za otvaranje i zatvaranje kanala 8 za potiskivanje goriva iz usisne komore 5, to jest iz crpke za ubrizgavanje ka mlaznici. Obloga 9 obuhvaća opisani dio crpke za ubrizgavanje i formira unutarnji prstenasti prostor 10 u koji izlaze otvori 6. Prostor 10 je povezan sa kanalom 11 za napajanje goriva. The injection pump shown comprises a cylindrical housing 1 in which a piston 2 whose head has a helicoidal edge 3 moves axially. The piston 2 moves back and forth between the G.M.T. (top dead center) and D.M.T. (bottom dead center). The intake chamber 5 is limited by the housing 1 and part 4 of the piston 2. The fuel supply to the chamber 5 is done through the opening 6 in the walls of the housing 1 near the bottom dead center (D.M.T.), so that the piston closes them in its entry stroke. Call sign 7 designates the discharge element as a whole, intended for opening and closing the channel 8 for pushing fuel from the suction chamber 5, i.e. from the injection pump to the nozzle. The cover 9 includes the described part of the injection pump and forms an internal annular space 10 into which the openings 6 exit. The space 10 is connected to the channel 11 for fuel supply.

Uređaj za podešavanje trenutka potiskivanja goriva prema mlaznici, kroz izlazni kanal 8, čini ventil 13 za otvaranje i zatvaranje spojnog kanala 14 koji služi za povezivanje komore 5 s prstenastim prostorom 10. Ventil 13 obuhvaća upravljački klip 15 u cilindru 16 izvedenom u gornjem dijelu crpke. Dio cilindra 16 iznad klipa 15 je povezan sa hidrauličkim upravljačkim kolom 17 koje obuhvaća elektro-ventil 18 koji alternativno vrši povezivanje sa hidrauličnim izvorom 19 niskog pritiska ili hidrauličnim izvorom 20 relativno visokog pritiska. The device for adjusting the moment of pushing the fuel towards the nozzle, through the output channel 8, forms a valve 13 for opening and closing the connecting channel 14, which serves to connect the chamber 5 with the annular space 10. The valve 13 includes the control piston 15 in the cylinder 16 located in the upper part of the pump. The part of the cylinder 16 above the piston 15 is connected to the hydraulic control circuit 17, which includes an electro-valve 18, which alternatively connects to the hydraulic source 19 of low pressure or the hydraulic source 20 of relatively high pressure.

Električno kolo 22 za upravljanje elektro-ventilom 18 obuhvaća, serijski povezane, senzor 23, uređaj 24 za kašnjenje i prekidač za preveliku brzinu. The electrical circuit 22 for controlling the electro-valve 18 includes, connected in series, a sensor 23, a delay device 24 and an overspeed switch.

Senzor 23 se spreže s elementom 26 koji čini dio obrtnog elementa 27 spojenog sa klipnjačom (nije prikazana). The sensor 23 is connected to the element 26 which forms part of the rotating element 27 connected to the piston rod (not shown).

Uređaj 24 za kašnjenje je predviđen da uspori signale senzora 23, u funkciji jednog ili više parametara motora, kao sto su pritisak zraka ispred motora, položaj zupčaste letve crpke za gorivo, ili maksimalan pritisak sagorijevanja, ili brzinu obrtanja motora. The delay device 24 is provided to delay the signals of the sensor 23, as a function of one or more engine parameters, such as air pressure in front of the engine, fuel pump rack position, or maximum combustion pressure, or engine speed.

Informacije radi, treba uočiti da hidraulični izvor 19 može ostvariti pritisak od 1 do 5 bara. Hidraulični pritisak izvora 20 može biti reda veličine od 20 bara. Opisana crpka za ubrizgavanje funkcionira na sljedeći način: For the sake of information, it should be noted that the hydraulic source 19 can achieve a pressure of 1 to 5 bar. The hydraulic pressure of the source 20 can be of the order of 20 bar. The described injection pump works as follows:

Pokrećući se prema položaju G.M.T., klip 2 zatvara usisne otvore 6 i nastavlja svoj hod. Za vrijeme ovog prvog perioda uzlaznog hoda klipa 2, elektro-ventil 18 je u takvom položaju da hidraulični fluid iz izvora 20 višeg pritiska djeluje na klip 15 ventila 13, te je on otvoren. To znači da je usisna komora 5 u vezi s prstenastim prostorom 10 preko spojnog kanala 14. Potisno gorivo istječe u prostor 10. Pritisak u usisnoj komori 5 ostaje relativno nizak, nedovoljan djelovati na otvaranje elementa 7 za pražnjenje, postavljenog u izlaznom kanalu 8 prema mlaznici. Moving towards the G.M.T. position, the piston 2 closes the suction ports 6 and continues its stroke. During this first period of the upward stroke of the piston 2, the electro-valve 18 is in such a position that the hydraulic fluid from the source 20 of higher pressure acts on the piston 15 of the valve 13, and it is open. This means that the suction chamber 5 is connected to the annular space 10 via the connection channel 14. The propellant flows into the space 10. The pressure in the suction chamber 5 remains relatively low, insufficient to act on the opening of the discharge element 7, placed in the outlet channel 8 towards the nozzle. .

U danom trenutku, određenom izumom elementa 26 obrtnog elementa 27 ispred senzora 23, električni impuls se upućuje ventilu 18 koji mijenja položaj. Klip 15 biva izložen nižem pritisku iz hidrauličnog izvora 19. Pad pritiska izaziva zatvaranje ventila 13. Kako klip 2 nastavlja svoj hod prema G.M.T., pritisak u usisno] komori 5 raste i izaziva otvaranje elementa 7. To znači da počinje potiskivanje goriva prema mlaznici. Potiskivanje se završava u trenutku kada helikoidalni rub 3 naiđe na otvor 6. At a given moment, determined by the invention of the element 26 of the rotating element 27 in front of the sensor 23, an electrical impulse is sent to the valve 18 which changes its position. Piston 15 is exposed to lower pressure from hydraulic source 19. The pressure drop causes valve 13 to close. As piston 2 continues its stroke toward G.M.T., the pressure in suction chamber 5 increases and causes element 7 to open. This means that fuel is pushed toward the nozzle. Pushing ends when the helicoidal edge 3 meets the opening 6.

Ventil 13 se ponovo otvara usljed nadpritiska u komori 5 pri silaznom hodu klipa 2 prema položaju D.M.T., u trenutku kada su otvori 6 ponovo zatvoreni. Ovo otvaranje ventila 13 za vrijeme silaznog hoda klipa 2 doprinosi dobrom punjenju komore 5. Ponovo se klip 15 ventila izlaže višem pritisku, da bi ventil 13 ostao u otvorenom položaju. The valve 13 opens again due to the overpressure in the chamber 5 during the downward stroke of the piston 2 towards the D.M.T. position, at the moment when the openings 6 are closed again. This opening of the valve 13 during the downward stroke of the piston 2 contributes to a good filling of the chamber 5. Again, the valve piston 15 is exposed to a higher pressure, so that the valve 13 remains in the open position.

Trenutak kada će senzor 23 dati impuls elektro-ventilu 18 može biti tako izabran da bude relativno blizu trenutka početka potiskivanja klipa 2 u odnosu na otvore 6. Da bi se kasnije mogao mijenjati trenutak početka potiskivanja, kao rezultat zatvaranja ventila 13, dovoljno je da se, preko uređaja 24 za kašnjenje, ostvari kašnjenje između trenutka generiranja signala na senzoru 23 i trenutka pada pritiska na klipu 15 ventila 13. Ovo kašnjenje može biti izabrano u funkciji brzine motora, u funkciji pritiska zraka ispred motora, položaja zupčaste letve itd. The moment when the sensor 23 will give an impulse to the electro-valve 18 can be chosen so as to be relatively close to the moment when the piston 2 starts pushing against the openings 6. In order to be able to change the moment when the push starts later, as a result of closing the valve 13, it is enough to , through the delay device 24, creates a delay between the moment of signal generation on the sensor 23 and the moment of pressure drop on the piston 15 of the valve 13. This delay can be chosen as a function of the engine speed, as a function of the air pressure in front of the engine, the position of the toothed rack, etc.

Uređaj prema izumu može djelovati i u slučaju prevelike brzine. U tom cilju dovoljno je izbjeći mogućnost da pritisak na klipu 15 ventila 13 opadne. The device according to the invention can also work in case of excessive speed. To this end, it is sufficient to avoid the possibility that the pressure on the piston 15 of the valve 13 drops.

U slučaju greške ili kvara u sustavu podešavanja prema izumu, sustav se može staviti izvan pogona razdvajanjem hidrauličnog kola od izvora 20 višeg pritiska. Trenutak potiskivanja goriva prema mlaznici je tada određen kretanjem klipa 2 u odnosu na otvoru 6, to jest, motor radi s mehanički određenim parametrima. Mehaničkim sredstvima, podešavanjima pri kratkom zastoju, moguće je predpaljenje pomaknuti i osigurati da motor radi iako je paljenje fiksno. In the event of an error or malfunction in the adjustment system according to the invention, the system can be put out of operation by disconnecting the hydraulic circuit from the source 20 of higher pressure. The moment of pushing the fuel towards the nozzle is then determined by the movement of the piston 2 in relation to the opening 6, that is, the engine works with mechanically determined parameters. By mechanical means, adjustments during a short stop, it is possible to move the pre-ignition and ensure that the engine runs even though the ignition is fixed.

Iz opisa izuma se vidi da specifična rješenja prema izumu omogućavaju podešavanje trenutka ubrizgavanja, ili s druge strane, predpaljenje (predubrizgavanje) u značajnom opsegu, bez korištenja kompliciranih i glomaznih konstrukcija. S druge strane, prednost je što je kraj potiskivanja određen prolazom helikoidalnog ruba 3 ispred otvora 6, a ne otvaranjem ventila 13, a za otvaranje ventila 13 nije potrebno savladavati visok pritisak. From the description of the invention, it can be seen that specific solutions according to the invention enable adjustment of the injection moment, or on the other hand, pre-ignition (pre-injection) to a significant extent, without using complicated and bulky constructions. On the other hand, the advantage is that the end of pushing is determined by the passage of the helicoidal edge 3 in front of the opening 6, and not by opening the valve 13, and it is not necessary to overcome high pressure to open the valve 13.

Važna karakteristika ovog izuma je u tome što se pokretni dijelovi kreću u uvjetima niskih pritisaka, što je vrlo značajno za sigurnost rada. An important feature of this invention is that the moving parts move under low pressure conditions, which is very important for work safety.

Korisno je podvući, daje cilj podešavanja trenutka potiskivanja izvršiti optimaliziranje uvjeta rada motora, kako bi se smanjila specifična potrošnja, podešavanjem maksimalnog pritiska ciklusa podešavajući trenutak ubrizgavanja. U okviru izuma moguće su mnoge varijante. Umjesto elektro-ventila mogu se koristiti svi odgovarajući elementi kao što su piezoelektrični ventili, ili drugi višeprolazni elementi. It is useful to underline that the goal of adjusting the compression moment is to optimize the engine's operating conditions, in order to reduce specific consumption, by adjusting the maximum cycle pressure by adjusting the injection moment. Many variants are possible within the scope of the invention. Instead of electro-valves, all suitable elements such as piezoelectric valves or other multi-pass elements can be used.

Također treba napomenuti, da klip 15 ne mora obvezno biti klizno zabrtvljen u cilindru 16. Zabrtvljenost nije neophodna ako se koristi gorivo u hidrauličnom sustavu 17, 19, 20. U slučaju korištenja ulja, u hidrauličnom sustavu mogu se tolerirati mala curenja. Umjesto hidrauličnog sustava upravljačkog kola može se koristiti i električno upravljanje ventilima, na primjer pomoću solenoida. It should also be noted that the piston 15 does not necessarily have to be slidingly sealed in the cylinder 16. Sealing is not necessary if fuel is used in the hydraulic system 17, 19, 20. In the case of using oil, small leaks can be tolerated in the hydraulic system. Instead of the hydraulic system of the steering wheel, electric control of the valves can be used, for example by means of solenoids.

Izum nije ograničen na prikazani i opisani način izvođenja, koji je dan samo kao primjer, već obuhvaća sve ekvivalentne tehnike i opisane uređaje kao i njihove kombinacije. The invention is not limited to the shown and described embodiment, which is given only as an example, but includes all equivalent techniques and described devices as well as their combinations.

Claims

1. Injection pump for internal combustion engines, with a device for adjusting the moment of fuel thrust, with a fuel suction chamber, which is fed through the inlet openings and in which the piston on the head of which is made to move reciprocatingly, between the top and bottom dead centers a helicoidal edge, which during this movement closes the inlet openings, and a device for adjusting the moment of pushing fuel from the pump to the nozzle, which includes a valve for opening and closing the channel connecting the chamber and the space connected to the fuel source, as well as a control system, indicated by which is the sensor (23) which is coupled to the element (26) of the rotating element (27) of the engine, connected to the valve (18), which is connected on one side to the cylinder of the control piston (15) of the valve (13), while on the other side connected to the source (19) of low pressure and to the source (20) of relatively high pressure, whereby the valve (13) is placed between the connecting channel (14), which connects the suction chamber (5) with the internal space (10).

2. Injection pump according to claim 1, characterized in that the sensor (23) is connected to the valve (18) via a delay device (24).

3. An injection pump according to claim 1, characterized in that the sensor (23) is connected to the valve (18) via series-connected delay devices (24) and an overspeed switch (25).