Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
  • F02M61/16—Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
  • F02M61/20—Closing valves mechanically, e.g. arrangements of springs or weights or permanent magnets; Damping of valve lift
  • F02M61/205—Means specially adapted for varying the spring tension or assisting the spring force to close the injection-valve, e.g. with damping of valve lift
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M47/00—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure
  • F02M47/02—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure of accumulator-injector type, i.e. having fuel pressure of accumulator tending to open, and fuel pressure in other chamber tending to close, injection valves and having means for periodically releasing that closing pressure
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M47/00—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure
  • F02M47/02—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure of accumulator-injector type, i.e. having fuel pressure of accumulator tending to open, and fuel pressure in other chamber tending to close, injection valves and having means for periodically releasing that closing pressure
  • F02M47/027—Electrically actuated valves draining the chamber to release the closing pressure
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M63/00—Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M39/00 - F02M57/00 or F02M67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M39/00 - F02M61/00 or F02M67/00; Combination of fuel pump with other devices, e.g. lubricating oil pump
  • F02M63/02—Fuel-injection apparatus having several injectors fed by a common pumping element, or having several pumping elements feeding a common injector; Fuel-injection apparatus having provisions for cutting-out pumps, pumping elements, or injectors; Fuel-injection apparatus having provisions for variably interconnecting pumping elements and injectors alternatively
  • F02M63/0225—Fuel-injection apparatus having a common rail feeding several injectors ; Means for varying pressure in common rails; Pumps feeding common rails
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
  • F02M2200/28—Details of throttles in fuel-injection apparatus
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M2547/00—Special features for fuel-injection valves actuated by fluid pressure
  • F02M2547/001—Control chambers formed by movable sleeves
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
  • F02M59/44—Details, components parts, or accessories not provided for in, or of interest apart from, the apparatus of groups F02M59/02 - F02M59/42; Pumps having transducers, e.g. to measure displacement of pump rack or piston
  • F02M59/46—Valves
  • F02M59/466—Electrically operated valves, e.g. using electromagnetic or piezoelectric operating means
  • F02M59/468—Electrically operated valves, e.g. using electromagnetic or piezoelectric operating means using piezoelectric operating means
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M63/00—Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M39/00 - F02M57/00 or F02M67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M39/00 - F02M61/00 or F02M67/00; Combination of fuel pump with other devices, e.g. lubricating oil pump
  • F02M63/0012—Valves
  • F02M63/0014—Valves characterised by the valve actuating means
  • F02M63/0015—Valves characterised by the valve actuating means electrical, e.g. using solenoid
  • F02M63/0026—Valves characterised by the valve actuating means electrical, e.g. using solenoid using piezoelectric or magnetostrictive actuators

Definitions

• the invention is based on an injection arrangement for a fuel storage injection system of an internal combustion engine according to the type defined in more detail in claim 1.
• fuel accumulator injection systems for example common rail injection systems, have a high-pressure fuel distributor or rail for an internal combustion engine with a plurality of combustion chambers, from which a plurality of high-pressure fuel supply paths, each to one of the combustion chambers of the internal combustion engine protruding injection nozzle.
• the fuel injection into the respective combustion chamber is controlled by means of a nozzle needle, which opens and closes the respective injection nozzle depending on the pressure in a valve control chamber.
• an always open inlet channel can be provided, through which the fuel under the rail pressure from the respective can flow into the valve control chamber.
• a separate drain eg allows fuel to be drained from the valve control chamber, thus relieving pressure in the valve control chamber.
• the drain path can be blocked at a shut-off point by means of a shut-off device, so that the pressure level in the valve control chamber and thus the position of the nozzle needle can be influenced by optionally blocking and releasing the drain path.
• the drain path With an inward opening valve, the drain path is opened to open the valve, fuel flowing out of the valve control chamber.
• the associated drop in pressure in the valve control chamber leads to the lifting of the nozzle needle from the injection nozzle, and fuel emerges from the injection nozzle. If the drainage path is blocked again, the pressure in the valve control chamber increases again due to the fuel flowing in via the inlet channel. As a result of this pressure increase, the nozzle needle is pressed against the injection nozzle again and closes it.
• the drain path and the inlet channel are usually designed so that when the drain path is open, the flow rate of the fuel flowing through the drain path is greater than the flow rate of the fuel flowing through the inlet channel, so that the fuel volume in the valve control chamber is effectively smaller.
• the injector In order to be able to precisely meter the amount of fuel injected, it is essential that the injector can be opened and closed quickly.
• the closing process in particular has proven to be critical in practice. Because of the comparatively small Passage cross section of the inlet channel often flows in too little fuel to achieve the desired fast closing times. This is particularly true if the pressure in the control chamber does not drop very far below the pressure in the fuel supply path after the valve has closed, during the injection process. The then only comparatively small pressure difference between the fuel supply path and the valve control chamber leads to a correspondingly low inflowing fuel flow.
• bypass duct branches off from the fuel supply path and opens directly into the discharge path upstream of the shut-off point of the drainage path, if one considers the fuel's drainage direction along the drainage path. If the downstream part of the outlet path is blocked, this bypass channel forms an auxiliary channel connected in parallel to the inlet channel, through which an additional quantity of fuel can flow from the fuel supply path via the upstream part of the outlet path into the valve control chamber. It has been shown that higher closing speeds of the nozzle needle can be achieved in this way.
• a counterforce is derived from the prevailing fuel pressure on the nozzle needle, which counteracts the force exerted on the nozzle needle by the pressure in the valve control chamber.
• the throttle in the fuel supply path now brings about a pressure drop in these downstream parts of the fuel supply path and thus a reduction in the counterforce.
• a lower pressure in the valve control chamber is then sufficient to move the nozzle needle into its closed position.
• the two throttles in the bypass channel and in the fuel supply path entail considerable additional expenditure in terms of production technology, since they are very small structures in which compliance with the permissible tolerances is very difficult in terms of production technology.
• the throttle in the fuel supply path leads to a reduced injection pressure with which the power substance is injected into the combustion chamber. The loss of injection pressure can easily amount to up to 200 bar.
• the injection arrangement according to the invention for a fuel accumulator injection system of an internal combustion engine with the features of claim 1 has the advantage that, by quickly closing the nozzle needle, a highly precise metering of the fuel injection quantity with little leakage and a valve that is easy to manufacture is possible.
• the injection arrangement has an injection nozzle which projects into a combustion chamber of the internal combustion engine and can be supplied with fuel from a high-pressure fuel distributor of the accumulator injection system via a high-pressure fuel supply path, and an injection needle which opens and closes the injection nozzle depending on the pressure in a valve control chamber.
• an inlet channel branching off from the fuel supply path opens into the valve control chamber, and an outlet path starting from the valve control chamber enables the fuel to flow out of the valve control chamber.
• An auxiliary channel opening into the drain path also branches off from the fuel supply path.
• a shut-off device is provided, by means of which the drainage path — based on a fuel drainage device — downstream of the junction parts of the auxiliary channel in the drainage path can be blocked against fuel drainage.
• the shut-off device is also used to block the auxiliary channel against fuel flow. is formed, in such a way that when the drain path is blocked, the auxiliary channel is unlocked and vice versa.
• the auxiliary channel can be blocked. If the drain path is open during an injection process, fuel can thus be prevented from flowing unused through the auxiliary channel from the fuel supply path.
• the auxiliary channel can be optimized essentially only so that the valve control chamber is refilled as quickly as possible after the drain path has been blocked, and the nozzle needle is moved back into its closed position as quickly as possible.
• auxiliary channel can be substantially unthrottled over its entire length. This simplifies the manufacture of the injection arrangement.
• the shut-off device has two separately operable shut-off bodies for the auxiliary channel and the drainage path. This can be expedient, for example, if the auxiliary channel and the drain path are not to be opened or locked in a time-synchronous manner, but rather with a time delay. However, a solution can be implemented with less effort in which the shut-off device has shut-off surfaces formed on a common shut-off body for locking the drain path and for locking the auxiliary channel.
• shut-off body is designed as a seat element which can be moved back and forth between two opposite valve seats, one of the valve seats forming a shut-off point for the drainage path and the other valve seat forming a shut-off point for the auxiliary channel.
• the shut-off body is designed as a slide element of a slide valve.
• a piezoelectric actuator arrangement can preferably be used to actuate the shut-off device, but alternatively an electromagnetic actuator arrangement can also be provided.
• FIG. 1 shows a schematic, partial representation of a storage injection system according to the invention with an injector assembly for internal combustion engines shown in longitudinal section, and
• FIG. 2 shows a simplified, partial illustration of a shut-off valve of the injector assembly according to FIG. 1.
• the storage injection system shown in FIG. 1, which represents a so-called common rail injection system, has a symbolically indicated pressure source 10, which preferably feeds diesel fuel into a manifold or rail 12 at a high pressure of, for example, more than 1500 bar. From the manifold 12 go several fuel supply lines 14, each one for supplying fuel
• the injection nozzle 18 is part of an injector assembly, generally designated 20, which can be used as a preassembled structural unit in a cylinder block of the internal combustion engine.
• the injector assembly 20 has a housing assembly 22 with a nozzle housing 24 and a valve housing 26.
• a guide bore 30 is formed which extends along a housing axis 28 and in which an elongated nozzle needle 32 is guided so as to be axially movable.
• the nozzle needle 32 has a closing surface 36 with which it can be brought into tight contact with a needle seat 38 formed on the nozzle housing 24.
• the nozzle needle 32 When the nozzle needle 32 abuts the needle seat 38, i.e. is in the needle closed position, the fuel outlet from a nozzle hole arrangement 40 is blocked at the end of the nozzle housing 24 which projects into the combustion chamber 16. On the other hand, is it lifted off the needle seat 38, i.e. In the needle opening position, fuel can flow from an annular space 42 formed between the nozzle needle 32 and the peripheral jacket of the guide bore 30 past the needle seat 38 to the nozzle hole arrangement 40 and be injected there into the combustion chamber 16.
• the nozzle needle 32 is biased towards its closed position by a biasing spring 44.
• the biasing spring 44 is accommodated in a spring chamber 46 formed in the nozzle housing 24.
• a sleeve 48 which seals the end of the nozzle needle 32 remote from the combustion chamber, but which is axially movable and bites into the valve housing 26 with a biting edge.
• it is supported on the nozzle needle 32 by means of a spring plate 50 plugged onto the nozzle needle 32.
• a bore 52 formed in the housing assembly 22 opens into the spring chamber 46, into which fuel which is essentially under high pressure or rail pressure is introduced via the relevant fuel supply line 14. From the spring chamber 46, the fuel passes into the annular space 42 via a channel formed in the nozzle housing 24 or — as here — past a system of flats or incisions 54 machined into the peripheral jacket of the nozzle needle 32.
• a valve control chamber 58 is delimited between an end face 56 of the nozzle needle 32, the sleeve 48 and the valve housing 26 which is remote from the combustion chamber and into which an inlet duct 60 designed as a throttle opens. Fuel can flow from the spring chamber 46 into the valve control chamber 58 through the inlet throttle 60. Fuel can flow out of the valve control chamber 58 to a relief chamber (not shown in more detail) via an outlet duct 64 containing an outlet throttle 62.
• a shut-off valve 68 preferably a piezoelectric actuator 66, which can be actuated, allows the fuel outflow to the relief chamber to be shut off.
• an electromagnetic actuator can of course also be used instead of a piezoelectric actuator.
• the flow cross-sections of the always open inlet throttle 60 and the outlet throttle 62 are matched to one another in such a way that the inflow through the inlet throttle 60 is less than the outflow through the outlet channel 64 and accordingly a net outflow of fuel results.
• the following pressure drop in the valve control chamber 58 causes the closing force to drop below the opening force and to lift the nozzle needle 32 inward from the needle seat 38.
• shut-off valve 68 is brought back into its blocking position. This blocks the fuel outflow through the outlet channel 64. Fuel continues to flow from the spring chamber 46 into the valve control chamber 58 through the inlet throttle 60, and the pressure in the valve control chamber 58 increases again. As soon as the pressure in the valve control chamber 58 reaches a level at which the closing force is greater than the opening force, the nozzle needle 32 goes into it
• An auxiliary channel 72 is therefore provided, by means of which an additional fuel flow into the valve control chamber 58 is achieved when the shut-off valve 68 is blocked.
• the auxiliary channel 72 branches off from the bore 52 and, like the inlet throttle 60, is fed with fuel which is essentially under the rail pressure.
• the additional fuel flow through the auxiliary channel 72 causes the pressure in the valve control chamber 58 to rise to the level required to move the nozzle needle 32 from its opening position into its closing position more quickly than when it is filled by the inlet throttle 60 alone to convince lung.
• the amount of fuel injected into the combustion chamber 16 can be metered more finely.
• the shut-off valve 68 not only controls the fuel flow through the drain channel 64, but also the fuel flow through the auxiliary channel 72. It is designed as a 3/2-way valve, three of which Connections of an upstream part 64 ′ of the discharge channel 64, a downstream part 64 ′′ of the discharge channel 64 and the auxiliary channel 72 are occupied, based on the fuel discharge direction.
• a first switch position which represents a blocking position
• the shut-off valve 68 blocks the downstream part 64 ′′ of the outlet channel 64, but releases a flow connection between the auxiliary channel 72 and the upstream part 64 ′ of the outlet channel 64.
• a fuel outflow from the valve control chamber 58 to the relief chamber is impossible, but a fuel inflow into the valve control chamber 58 via the auxiliary duct 72 and the upstream part 64 'of the outlet duct 64 is possible.
• the shut-off valve 68 In its second switch position, which represents an open position, the shut-off valve 68 allows fuel to flow out of the valve control chamber 58 through the upstream part 64 'of the outlet channel 64 into its downstream part 64' ', but blocks the auxiliary channel 72. A fuel flow through the auxiliary channel 72 thus occurs the second switching position, which is why in this second switching position no leakage has to be accepted beyond the amount of fuel flowing out of the valve control chamber 58.
• the shut-off valve 68 is designed as a seat valve with a seat element 76 arranged in a valve chamber 74, in the present case a spherical valve closing member.
• the seat element 76 is adjustable by means of the actuator 66 between two seats 78, 80 opposite one another in the adjusting direction of the actuator 66, one seat 78 of which corresponds to the first switching position and the other seat 80 of which corresponds to the second switching position.
• the downstream part 64 ′′ of the outlet channel 64 opens into the valve chamber 74, at the seat 80 the auxiliary channel 72.
• the upstream part 64 ′ of the outlet channel 64 opens laterally between the two seats
• shut-off point for the drain channel 64 which is formed here by the seat 78, is downstream of the point at which the auxiliary channel 72 is in an imaginary, along the two parts
• 64 ', 64' 'of the drain channel 64 opens out via the valve chamber 74.
• the seat element or valve closing member 76 is shown in contact with the seat 78 with a solid line.
• the second switching position, in which the seat element 76 bears against the seat 80, is indicated by dashed lines. It is understood that the proportions in Figure 2 are not realistic.
• the adjustment path of the seat element 76 between the two seats 78, 80 can easily be in the range of only a few tens or hundreds of micrometers.
• the seat element 76 is expediently prestressed against the seat 78 by means of a valve spring 82 which can be seen in FIG. 1 and is accommodated in the valve chamber 74.
• the auxiliary channel 72 is designed over its entire length without an essential throttling point. Since it is downstream If the outlet throttle 62 opens into the mentioned imaginary outlet path, there is anyway a throttle point, namely the outlet throttle 62, in the flow path that the fuel flow going through the auxiliary channel 72 into the valve control chamber 58 travels when the shut-off valve 68 is blocked.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Fuel-Injection Apparatus (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=7642738

Family Applications (1)

Country Status (6)

Families Citing this family (26)

Family Cites Families (6)

• 2000
  • 2000-05-18 DE DE10024703A patent/DE10024703A1/de not_active Ceased
• 2001
  • 2001-03-23 KR KR1020027000679A patent/KR20020019538A/ko not_active Application Discontinuation
  • 2001-03-23 AT AT01929256T patent/ATE306613T1/de not_active IP Right Cessation
  • 2001-03-23 WO PCT/DE2001/001123 patent/WO2001088365A1/fr active IP Right Grant
  • 2001-03-23 DE DE50107694T patent/DE50107694D1/de not_active Expired - Lifetime
  • 2001-03-23 EP EP01929256A patent/EP1287253B1/fr not_active Expired - Lifetime
  • 2001-03-23 JP JP2001584731A patent/JP2003533635A/ja active Pending

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events