FR2527195A1 - Flow controller for fuel dispensing system - uses calibrated springs to operate valves in secondary and by=pass circuits when electronic controller switches off pump - Google Patents

Flow controller for fuel dispensing system - uses calibrated springs to operate valves in secondary and by=pass circuits when electronic controller switches off pump Download PDF

Info

Publication number
FR2527195A1
FR2527195A1 FR8208878A FR8208878A FR2527195A1 FR 2527195 A1 FR2527195 A1 FR 2527195A1 FR 8208878 A FR8208878 A FR 8208878A FR 8208878 A FR8208878 A FR 8208878A FR 2527195 A1 FR2527195 A1 FR 2527195A1
Authority
FR
France
Prior art keywords
valve
pressure
pump
value
spring
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
FR8208878A
Other languages
French (fr)
Inventor
Suzanne Pichard
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Satam Industries
Original Assignee
Satam Industries
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Satam Industries filed Critical Satam Industries
Priority to FR8208878A priority Critical patent/FR2527195A1/en
Publication of FR2527195A1 publication Critical patent/FR2527195A1/en
Pending legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B67OPENING, CLOSING OR CLEANING BOTTLES, JARS OR SIMILAR CONTAINERS; LIQUID HANDLING
    • B67DDISPENSING, DELIVERING OR TRANSFERRING LIQUIDS, NOT OTHERWISE PROVIDED FOR
    • B67D7/00Apparatus or devices for transferring liquids from bulk storage containers or reservoirs into vehicles or into portable containers, e.g. for retail sale purposes
    • B67D7/06Details or accessories
    • B67D7/08Arrangements of devices for controlling, indicating, metering or registering quantity or price of liquid transferred
    • B67D7/28Arrangements of devices for controlling, indicating, metering or registering quantity or price of liquid transferred with automatic means for reducing or intermittently interrupting flow before completion of delivery, e.g. to produce dribble feed
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B67OPENING, CLOSING OR CLEANING BOTTLES, JARS OR SIMILAR CONTAINERS; LIQUID HANDLING
    • B67DDISPENSING, DELIVERING OR TRANSFERRING LIQUIDS, NOT OTHERWISE PROVIDED FOR
    • B67D7/00Apparatus or devices for transferring liquids from bulk storage containers or reservoirs into vehicles or into portable containers, e.g. for retail sale purposes
    • B67D7/06Details or accessories
    • B67D7/36Arrangements of flow- or pressure-control valves

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Mathematical Physics (AREA)
  • Theoretical Computer Science (AREA)
  • Control Of Fluid Pressure (AREA)

Abstract

A pump delivers fuel through a degassing assembly and decompression valve to a measuring unit. An electrovalve operates a valve to allow the fuel to flow in a tube to a distribution valve which is operated by a lever. A bypass circuit for the pump is controlled by a valve which has a calibrated spring for a pressure value above the nominal delivery pressure. A secondary delivery circuit contains a small cross sectioned orifice controlled by a valve whose spring is calibrated for a delivery pressure between the nominal value and the bypass opening pressure. This allows a small precise amount of fuel to be delivered. An electronic processor controls the electrovalve and the pump power circuit.

Description

Pour réaliser la distribution d'une quantité ou d'une valeur prédéterminée de carburant (ou autre liquide) il est nécessaire de pouvoir arrêter la distribution de manière très précise. In order to dispense a predetermined quantity or value of fuel (or other liquid), it is necessary to be able to stop dispensing very precisely.

Les moyens connus consistent en général en une élec- trovanne comportant deux circuits hydrauliques dont la fermeture est réalisée grâce à des clapets commandés chacun par une bobine. The known means generally consist of a solenoid valve comprising two hydraulic circuits, the closure of which is achieved by means of valves each controlled by a coil.

L'un des circuits appelé circuit principal permet d'.atteindre le débit normal, le deuxième circuit appelé circuit secondaire permet d'avoir un faible débit,
Pendant la quasi totalité de la distribution les deux circuits sont ouverts ; lorsqu'on est sur le point d'atteindre la quantité ou la valeur prédéterminée une commande électrique coupe l'alimentation de la bobine du circuit principal ce qui ferme ce circuit ; la fin de la distribution s'effectue alors par le circuit secondaire, et lorsque la valeur prédéterminée est atteinte, l'excitation de la deuxième bobine commandant le deuxième clapet est coupée, ce qui provoque la fermeture de ce clapet ; le débit étant faible, la distribution s'arr & e avec précision
Ce moyen précis demande un dispositif complexe et coûteux.Un autre moyen plus simple consiste à remplacer le circuit secondaire par un simple trou de fuite ; mais ce moyen est peu précis car il est sensible au phénomène de "lancé" de moteur de pompe en particulier
La présente invention a pour objet un dispositif allégé capable de remplir simplement et par des moyens peu coûteux la fonction demandée, tout en conservant une grande précision,
Le dispositif selon l'invention se caractérise par la combinaison d'un circuit principal de distribution commandé par électrovanne, avec un circuit de by-pass sur la pompe, contr81é par un clapet à ressort taré à une valeur supérieure à la pression de distribution et avec un circuit secondaire de distribution comportant un orifice de faible section contrôlé par un clapet dont le ressort est taré à une valeur comprise entre la pression de distribution et la pression d'ouverture du by-pass,
De préférence, le tarage du ressort du clapet du circuit secondaire est établi à une valeur voisine de la pression d'ouverture du by-pass1
Il résulte de cette disposition qu'une fois fermée l'électrouranne du circuit principal, le débit du circuit secondaire étant faible, la pression au niveau de la pompe monte ct ouvre le clapet du circuit secondaire ainsi que le clapet de by-pass ; lorsque l'ordre d'arrêt est donné au moteur de pompe, la pression chute brusquement et les clapets de by-pass ainsi que le clapet à bille se ferment quasi instantanément sans que le phénomène de 11lancé" du moteur de pompe ne puisse prolonger le débit du circuit secondaire.
One of the circuits called the main circuit allows to reach the normal flow, the second circuit called the secondary circuit allows to have a low flow,
During almost the entire distribution, the two circuits are open; when one is about to reach the predetermined quantity or value an electric control cuts the power supply to the coil of the main circuit which closes this circuit; the end of the distribution is then effected by the secondary circuit, and when the predetermined value is reached, the excitation of the second coil controlling the second valve is cut off, which causes the closure of this valve; the flow being low, the distribution stops precisely
This precise means requires a complex and costly device. Another simpler means consists in replacing the secondary circuit with a simple leak hole; but this means is imprecise because it is sensitive to the phenomenon of "launched" pump motor in particular
The subject of the present invention is a lightened device capable of simply and inexpensively fulfilling the requested function, while retaining great precision,
The device according to the invention is characterized by the combination of a main distribution circuit controlled by solenoid valve, with a by-pass circuit on the pump, controlled by a spring-loaded valve set to a value greater than the distribution pressure and with a secondary distribution circuit comprising a small section orifice controlled by a valve whose spring is calibrated to a value between the distribution pressure and the opening pressure of the bypass,
Preferably, the calibration of the valve spring of the secondary circuit is established at a value close to the opening pressure of the bypass1
It follows from this arrangement that once the solenoid valve of the main circuit is closed, the flow rate of the secondary circuit being low, the pressure at the level of the pump rises and opens the valve of the secondary circuit as well as the bypass valve; when the stop command is given to the pump motor, the pressure drops suddenly and the bypass valves as well as the ball valve close almost instantaneously without the phenomenon of "starting" of the pump motor being able to prolong the secondary circuit flow.

La perte de charge ainsi créée par le clapet du circuit secondaire provoque alors la fermeture du clapet prévu dans le robinet de distribution, lequel est taré à une valeur de pression fixée par les services métrologiques, et la distribution s'arrête.  The pressure drop thus created by the valve of the secondary circuit then causes the closure of the valve provided in the distribution valve, which is calibrated at a pressure value fixed by the metrological services, and the distribution stops.

L'invention est illustrée par le dessin joint sur lequel on a représenté le schéma hydraulique d'un distri buteur de carburant (ou autre liquide) muni des dispositions de l'invention,
En se reportant à ce schéma, on voit que le distributeur comporte une pompe 9 envoyant le liquide au mesureur 10 par l'intermédiaire du dégazeur il et du clapet de décompression 1 ; de là, le liquide passe dans l'électro- vanne 12 en soulevant le clapet 2 et atteint le conduit 4 pour aller au robinet de distribution 13 qui s'ouvre par action sur le levier 14.
The invention is illustrated by the attached drawing in which there is shown the hydraulic diagram of a fuel (or other liquid) distributor provided with the provisions of the invention,
Referring to this diagram, it can be seen that the distributor comprises a pump 9 sending the liquid to the measurer 10 via the degasser 11 and the pressure relief valve 1; from there, the liquid passes through the solenoid valve 12 by lifting the valve 2 and reaches the conduit 4 to go to the distribution valve 13 which opens by action on the lever 14.

Lorsque l'électrovanne 12 est en position d'ouverture, le clapet principal 2 s'ouvre sous la pression de distribution Po et l'écoulement se fait selon le débit nominal. When the solenoid valve 12 is in the open position, the main valve 2 opens under the distribution pressure Po and the flow takes place at the nominal flow rate.

La pression qui règne entre la pompe et le clapet 1 est supérieure à Po mais inférieure à la pression de by-pass
P(8) déterminée par le tarage du ressort du clapet 8,
Lorsque la valeur ou la quantité distribuée est inférieure à, mais voisine de celle prédéterminée, un calculateur électronique (non représenté) envoie un signal de fermeture de l'électrovanne 12; le clapet 2 se ferme et le débit se poursuit par le clapet 3(clapet à bille ou l'équi- valent).
The pressure between the pump and the valve 1 is higher than Po but lower than the bypass pressure
P (8) determined by the calibration of the valve spring 8,
When the value or the quantity dispensed is less than, but close to that predetermined, an electronic computer (not shown) sends a signal to close the solenoid valve 12; valve 2 closes and flow continues through valve 3 (ball valve or equivalent).

Compte tenu de la faible section de l'orifice 15 contrôlé par le clapet 3 le débit est faible1 La pression monte et atteint la valeur Pb dans le dégazeur, de sorte que le débit de la pompe passe en partie par le by-pass 16. Given the small section of the orifice 15 controlled by the valve 3, the flow rate is low1 The pressure rises and reaches the value Pb in the degasser, so that the flow rate of the pump passes in part through bypass 16.

Le tarage du ressort 7 étant établi pour que le clapet 3 s'ouvre pour une valeur de pression P(7) comprise entre PO et P(8) le clapet 3 s'ouvre et une partie du débit de la pompe 9 s'écoule par le clapet 3.The setting of the spring 7 being established so that the valve 3 opens for a pressure value P (7) between PO and P (8) the valve 3 opens and part of the flow rate of the pump 9 flows by the valve 3.

Au niveau du robinet 13, il est prévu, de façon connue, un ressort 5 qui ferme le clapet 6 lorsque la pression dè distribution tombe au-dessous d'une valeur P(5) fixée par les services métrologiques. At the tap 13, there is provided, in a known manner, a spring 5 which closes the valve 6 when the dispensing pressure falls below a value P (5) fixed by the metrological services.

Le clapet 3 et son ressort 7 sont dimensionnés pour fournir une perte de charge au niveau du clapet 3 telle que la pression dans le conduit 4 est voisine (légèrement supérieure) à la valeur P(5).  The valve 3 and its spring 7 are dimensioned to provide a pressure drop at the valve 3 such that the pressure in the conduit 4 is close (slightly higher) to the value P (5).

Lorsque la valeur ou la quantité prédéterminée à distribuer est atteinte, le calculateur coupe l'alimentation du moteur de la pompe 9. La pression dans la pompe tombe aussitôt et le clapet 3 se ferme quasi instantanément, la présence du clapet de by-pass 8 empêchant tout effet de lancé de la pompe. When the predetermined value or quantity to be dispensed is reached, the computer cuts the power to the pump motor 9. The pressure in the pump immediately drops and the valve 3 closes almost instantaneously, the presence of the bypass valve 8 preventing any pump launching effect.

La fermeture du clapet 3 est d'autant plus instantanée ou rapide que le tarage du ressort 7 est établi pour une pression P(7) voisine de la pression P(8) diminuée des pertes de charge entre la pompe 9 et le clapet 3 (pertes de charges dues notamment au clapet)
Lorsque le clapet 3 se ferme, la baisse de pression dans le conduit 4 est telle que la valeur P(5) est aussi tot atteinte et que le robinet 5 se ferme, arrêtant la distribution.
The closing of the valve 3 is all the more instantaneous or rapid as the calibration of the spring 7 is established for a pressure P (7) close to the pressure P (8) minus the pressure losses between the pump 9 and the valve 3 ( pressure losses due in particular to the valve)
When the valve 3 closes, the pressure drop in the conduit 4 is such that the value P (5) is also reached early and the valve 5 closes, stopping the dispensing.

On obtient ainsi un dispositif simplifié et-peu coûteux quoique de grande précision. This gives a simplified and inexpensive, albeit high precision, device.

Dans la description qui précède, le clapet 3 est décrit comlne étant un clapet à bille. Ceci constitue la forme prt5Lerée de réalisation de l'invention, mais tout autre système de clapet à ressort taré peut y être substitué. In the foregoing description, the valve 3 is described as being a ball valve. This constitutes the prt5Lerée embodiment of the invention, but any other calibrated spring valve system can be substituted for it.

La présente description est limitée aux organes se rapportant à l'invention, Les organes tels que le dégazeur 11, le mesureur lO, le clapet 1 avec son système de décompression, l'électrovanne 12 ou le robinet 13 sont du domaine de l'homme de l'art. Le système de dégazage 11comprend généralement un orifice de décompression 17. Il va de soi que cet orifice sera calibré, par rapport aux caractéristiques de la pompe pour que la pression dans le dégazeur 11 dépasse la valeur P(8) lorsque le clapet 2 est fermé.  The present description is limited to the organs relating to the invention. The organs such as the degasser 11, the measurer 10, the valve 1 with its decompression system, the solenoid valve 12 or the tap 13 are human art. The degassing system 11 generally comprises a decompression orifice 17. It goes without saying that this orifice will be calibrated, in relation to the characteristics of the pump so that the pressure in the degasser 11 exceeds the value P (8) when the valve 2 is closed .

Claims (2)

REVENDICATIONS 1. Disposition de distribution de carburant comprenant notamment une pompe alimentant un robinet par l'intermédiaire d'un mesureur et d'une électrovanne, caractérisé en ce que le circuit principal de distribution contrôlé par le clapet (2) commandé par l'électrovanne (12) est combiné avec d'une part un circuit de by-pass (16) de la pompe (9), contrôlé par un clapet (8) à ressort taré pour une valeur de pression P(8) supérieure à la valeur nominale de la pression de distribution et d'autre part un circuit secondaire de distribution comportant un orifice de faible section (15) contrôlé par un clapet (3) dont le ressort (7) est taré pour une valeur de pression de distribution P(7) comprise entre la pression nominale et la pression d'ouverture de bypass P(8). 1. Fuel distribution arrangement comprising in particular a pump supplying a tap via a measurer and a solenoid valve, characterized in that the main distribution circuit controlled by the valve (2) controlled by the solenoid valve ( 12) is combined with on the one hand a bypass circuit (16) of the pump (9), controlled by a valve (8) with calibrated spring for a pressure value P (8) greater than the nominal value of the distribution pressure and on the other hand a secondary distribution circuit comprising a small section orifice (15) controlled by a valve (3) whose spring (7) is calibrated for a value of distribution pressure P (7) included between the nominal pressure and the bypass opening pressure P (8). 3, Dispositif selon l'une quelconque des revendications précédentes, caractérisé en ce que le clapet (3) et son ressort (7) sont dimensionnés pour fournir une perte de charge au niveau du clapet (3) telle que la pression dans le conduit (4) est voisine (légerement supérieure) à la valeur P(5) à laquelle est taré le clapet du robinet de distribution.  3, Device according to any one of the preceding claims, characterized in that the valve (3) and its spring (7) are dimensioned to provide a pressure drop at the valve (3) such that the pressure in the conduit ( 4) is close (slightly higher) to the value P (5) at which the valve of the dispensing tap is calibrated. 2, Dispositif selon la revendication 1, caractérisé en ce que le tarage du ressort (7) du clapet (3) est établi pour une valeur P(7) voisine de la valeur P(8) d'ouverture du by-pass diminuée des pertes de charges de la partie du circuit'de distribution comprise entre la pompe (9) et -le clapet (3), 2, Device according to claim 1, characterized in that the calibration of the spring (7) of the valve (3) is established for a value P (7) close to the value P (8) of opening of the bypass minus pressure losses in the part of the distribution circuit between the pump (9) and the valve (3),
FR8208878A 1982-05-21 1982-05-21 Flow controller for fuel dispensing system - uses calibrated springs to operate valves in secondary and by=pass circuits when electronic controller switches off pump Pending FR2527195A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
FR8208878A FR2527195A1 (en) 1982-05-21 1982-05-21 Flow controller for fuel dispensing system - uses calibrated springs to operate valves in secondary and by=pass circuits when electronic controller switches off pump

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR8208878A FR2527195A1 (en) 1982-05-21 1982-05-21 Flow controller for fuel dispensing system - uses calibrated springs to operate valves in secondary and by=pass circuits when electronic controller switches off pump

Publications (1)

Publication Number Publication Date
FR2527195A1 true FR2527195A1 (en) 1983-11-25

Family

ID=9274232

Family Applications (1)

Application Number Title Priority Date Filing Date
FR8208878A Pending FR2527195A1 (en) 1982-05-21 1982-05-21 Flow controller for fuel dispensing system - uses calibrated springs to operate valves in secondary and by=pass circuits when electronic controller switches off pump

Country Status (1)

Country Link
FR (1) FR2527195A1 (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4102875A1 (en) * 1991-01-31 1992-08-20 Tecalemit Gmbh Deutsche Mechanically unlockable fluid coupling - has external forced venting and is for transport, storage and removal of fluids, connecting and securing fluid system
DE4331568A1 (en) * 1993-09-16 1995-03-23 Buerkert Gmbh Pilot operated valve for motor vehicle fuel systems
DE4331515A1 (en) * 1993-09-16 1995-03-23 Buerkert Gmbh Pilot-controlled shut-off valve with backflow preventer
EP1074509A1 (en) 1999-08-05 2001-02-07 Dresser Wayne Ab Secondary valve
WO2005017467A1 (en) * 2003-08-04 2005-02-24 Gilbarco Inc. Fuel flow meter device for a fuel dispenser, system and method
US7028561B2 (en) 2003-08-04 2006-04-18 Gilbarco Inc. Fuel dispenser fuel meter error detection device, system and method

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1957398A (en) * 1930-08-08 1934-05-01 Archibald L Wallace Gasoline dispensing system
US1990742A (en) * 1933-01-23 1935-02-12 Harvey E Marvel Nozzle controlling mechanism for liguid dispensing systems
US2164344A (en) * 1938-04-28 1939-07-04 Bell Telephone Labor Inc Signal transmission system
NL6805440A (en) * 1968-04-18 1969-10-21
FR2010320A1 (en) * 1968-06-07 1970-02-13 British Petroleum Co
US3916961A (en) * 1973-03-26 1975-11-04 Lawrence Dilger Liquid dispensing apparatus

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1957398A (en) * 1930-08-08 1934-05-01 Archibald L Wallace Gasoline dispensing system
US1990742A (en) * 1933-01-23 1935-02-12 Harvey E Marvel Nozzle controlling mechanism for liguid dispensing systems
US2164344A (en) * 1938-04-28 1939-07-04 Bell Telephone Labor Inc Signal transmission system
NL6805440A (en) * 1968-04-18 1969-10-21
FR2010320A1 (en) * 1968-06-07 1970-02-13 British Petroleum Co
US3916961A (en) * 1973-03-26 1975-11-04 Lawrence Dilger Liquid dispensing apparatus

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4102875A1 (en) * 1991-01-31 1992-08-20 Tecalemit Gmbh Deutsche Mechanically unlockable fluid coupling - has external forced venting and is for transport, storage and removal of fluids, connecting and securing fluid system
DE4331568A1 (en) * 1993-09-16 1995-03-23 Buerkert Gmbh Pilot operated valve for motor vehicle fuel systems
DE4331515A1 (en) * 1993-09-16 1995-03-23 Buerkert Gmbh Pilot-controlled shut-off valve with backflow preventer
US5551664A (en) * 1993-09-16 1996-09-03 Burkert Werke Gmbh & Co. Pilot controlled valve for motor vehicle tank systems
DE4331568C2 (en) * 1993-09-16 2001-10-18 Buerkert Gmbh Pilot operated valve for motor vehicle fuel systems
DE4331515C2 (en) * 1993-09-16 2002-07-18 Buerkert Gmbh Pilot operated shut-off valve with backflow preventer
EP1074509A1 (en) 1999-08-05 2001-02-07 Dresser Wayne Ab Secondary valve
WO2005017467A1 (en) * 2003-08-04 2005-02-24 Gilbarco Inc. Fuel flow meter device for a fuel dispenser, system and method
US6935191B2 (en) 2003-08-04 2005-08-30 Gilbarco Inc. Fuel dispenser fuel flow meter device, system and method
US7028561B2 (en) 2003-08-04 2006-04-18 Gilbarco Inc. Fuel dispenser fuel meter error detection device, system and method

Similar Documents

Publication Publication Date Title
US5685334A (en) Fuel additive metering system
EP2326811B1 (en) Device for controlling the fluid supply of a system
EP0119894A1 (en) Electromagnetically driven pressure time-dependent injection system for diesel engines, the valve needle being driven by discharging and charging a capacity
FR2527195A1 (en) Flow controller for fuel dispensing system - uses calibrated springs to operate valves in secondary and by=pass circuits when electronic controller switches off pump
FR2636056A1 (en) DEVICE FOR AUTOMATICALLY CONTROLLING A HYDROCARBON LANCE BASED ON THE GAS CONTENT OF HYDROCARBON
FR2641828A1 (en) VALVE DEVICE FOR OPERATING THE TELESCOPIC JACK OF A TRUCK TILTING BENCH
FR2504234A1 (en) VALVE FOR PRESSURE TANK
EP0034534B1 (en) Device for feeding fuel and controlling the viscosity of that fuel
EP0063968B1 (en) Installation and method for verifying the working conditions of a pressure and flow controlling device
CA1281262C (en) Pressurized fluid feed system
FR1464933A (en) Control device for raising and lowering tractor mounted implements
RU2307974C2 (en) Electronically controlled multiway valve for fuel tanks containing liquid petroleum gas
EP0109467B1 (en) Semi-automatic valve for the discharge of a predetermined volume of fluid under pressure, particularly a flush valve
US3370623A (en) Fluid dispensing device
US1923574A (en) Automatic shut-off for filling spouts
FR2638982A1 (en)
FR2516170A1 (en) PUMPS ASSEMBLY FOR FUEL INJECTION
US2929418A (en) Automatic gasoline dispensing hosenozzle valve
FR2555700A1 (en) PRESSURE VALVE
EP0916909A1 (en) Economiser for water heater
EP0077699B1 (en) Fully pneumatic generator for timed gas impulses
US2239207A (en) Liquid dispensing apparatus
EP0170754B1 (en) Degasing, cleaning, blocking and recuperating combination with enhanced security for measuring apparatus
EP1560003A1 (en) Liquefied gas feeding system for an internal combustion engine with detector of the minimum level of liquefied gas
EP0072269B1 (en) Fuel injector, especially for an internal-combustion engine