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
  • F02M55/00—Fuel-injection apparatus characterised by their fuel conduits or their venting means; Arrangements of conduits between fuel tank and pump F02M37/00
  • F02M55/02—Conduits between injection pumps and injectors, e.g. conduits between pump and common-rail or conduits between common-rail and injectors
  • F02M55/025—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
  • 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
  • F02M63/0031—Valves characterized by the type of valves, e.g. special valve member details, valve seat details, valve housing details
  • F02M63/0056—Throttling valves, e.g. having variable opening positions throttling the flow
• • 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
  • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
  • F02M2200/40—Fuel-injection apparatus with fuel accumulators, e.g. a fuel injector having an integrated fuel accumulator
• • 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
  • F02M2200/80—Fuel injection apparatus manufacture, repair or assembly
• • 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
  • F02M2200/80—Fuel injection apparatus manufacture, repair or assembly
  • F02M2200/803—Fuel injection apparatus manufacture, repair or assembly using clamp elements and fastening means; e.g. bolts or screws
• • 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
  • F02M2200/80—Fuel injection apparatus manufacture, repair or assembly
  • F02M2200/8076—Fuel injection apparatus manufacture, repair or assembly involving threaded members

Definitions

• the invention relates to an injector of a modular common rail fuel injection system with a high-pressure accumulator integrated in the injector body, wherein the injector has an injection nozzle with axially displaceably guided, surrounded by a nozzle chamber nozzle needle, a high-pressure accumulator with the nozzle chamber connecting high pressure line and a holding body, the the front side with the component forming the high-pressure accumulator, in particular storage tube is screwed and through which the high-pressure line passes, wherein a flow restrictor for limiting the amount of fuel delivered from the high-pressure accumulator to the injection nozzle is arranged downstream of the high-pressure accumulator.
• Modular common rail systems are characterized in that part of the storage volume present in the system is present in the injectors themselves. Modular common-rail systems are used on particularly large engines where the individual injectors may be mounted at a considerable distance from each other.
• the sole use of a common rail for all injectors is not useful in such engines, as it would come to a massive slump in injection pressure due to the long lines during injection, so with prolonged injection duration, the injection rate would noticeably break. In such engines, it is therefore intended to arrange a high-pressure accumulator inside each injector.
• Such a design is referred to as a modular structure, since each injector has its own high-pressure accumulator and thus can be used as a stand-alone module.
• a high-pressure accumulator is not to be understood as an ordinary conduit, but rather as a pressure-resistant vessel with an inflow or outflow, the diameter of which compared to the high-pressure accumulator. Pressure lines is significantly increased so that from the high-pressure accumulator a certain amount of injection can be delivered without causing an immediate pressure drop.
• Common rail systems can leak under unfavorable conditions, be it in the piping system or through defective injectors. Injectors with jamming nozzle needles, which lead to continuous injections into the combustion chamber, can cause considerable damage. These damages can lead to the fire of the vehicle or to the destruction of the engine. In order to avoid these dangers, flow rate limiters with a closing function are known, which close the inlet to the affected injector when a maximum removal quantity from the high-pressure accumulator is exceeded and thus decouple the injection-pump-side high-pressure from the injection-valve side.
• flow restrictors are usually arranged upstream of the storage volume.
• top-feed injectors the fuel is supplied via a high-pressure port of the injector at the top of the high-pressure accumulator
• the flow restrictor is usually attached to the upper end of the injector.
• side-feed injectors the supply of the fuel takes place via a lance which contacts the injector laterally
• the flow restrictor is usually arranged in front of the pressure pipe stub in a T-piece.
• the flow restrictor housing is either pressed into the injector holder body or mounted with a retaining ring in the holding body.
• Flow restrictors which are arranged in terms of flow in front of the storage volume, inherently have the disadvantage that they are to set much inaccurate. The reasons for this are the dead time and the damping effect of the storage volume and the influence of different fuel parameters such as temperature and viscosity or the fuel type (diesel or heavy oil).
• a further disadvantage of the flow restrictor arranged in the flow medium in front of the storage volume is that a considerably larger amount can still be injected when closing the flow restrictor due to the expansion volume of the high-pressure accumulator. This property is repeatedly classified as very critical, especially in the very conservative business of large marine engines.
• the installation of the flow restrictor at the top of Topfeed injectors also increase the mass there and thus worsen the vibration load capacity of the injector. Sidefeed injectors require a complex T-piece. Thus, two different solutions are required for the two injector concepts, which increases the variety of components.
• Flow restrictors which are built according to the storage volume in terms of electricity, require a press fit in the holding body or complex bore intersections in the case of the pressed-in design. Both constructions are very unfavorable in terms of fatigue strength in the extreme pressure loads prevailing in common rail systems. For example, in systems with a system pressure of 2200 bar pressure loads of up to 2500 bar can be observed.
• the present invention therefore aims to increase the fatigue strength, wherein in the holding body in particular interference fits and punctures for retaining rings or additional critical Bohrungsverschneidungen should be avoided. Furthermore, the same design concept for topfeed and sidefeed injectors should be used. Overall should be created with the same component cost as in the prior art training with a functionally optimal flow restrictor without the high pressure capacity of the holding body or the high-pressure accumulator is adversely affected.
• the invention provides in an injector of the type mentioned in essence that the flow restrictor is designed as a separate component, which is inserted between the holding body and the storage tube and is fixed by the screw of the holding body and storage tube.
• the flow restrictor is inserted between the holding body and the storage tube, the benefits of flow moderately built according to the storage volume flow restrictors are used.
• the flow restrictor is inserted between the holding body and the storage tube and fixed by the screwing of the holding body and storage tube, eliminates the need for pressing or securing using a locking ring, and there is a very simple construction, which has a high fatigue strength.
• the flow restrictor is in this case held only by the axial force generated during screwing of the holding body with the storage tube and clamped between these two components without the need for further fasteners as it were. So that when screwing the holding body with the storage tube on the
• Flow limiting component acting torque does not lead to a rotation of the flow restrictor component, provides a preferred embodiment of the invention that the holding body and the flow restrictor are secured against rotation by means of an axial fixing pin.
• the flow restrictor has a shoulder with a conical first sealing surface which cooperates with a formed on a shoulder of the storage tube conical sealing surface.
• Another high-pressure-tight connection is preferably achieved in that the flow restrictor component on the end face facing the holding body has a conical second sealing surface which cooperates with a conical sealing surface formed on an end face of the holding body.
• the arrangement of an anti-rotation in the form of locking pins can be omitted.
• Flow restrictor member formed cavity limited.
• the connection then takes place via the said cavity, which is particularly advantageous if a further parallel to the high-pressure line connected further high-pressure line passes through the holding body, which is on the one hand with the nozzle chamber and on the other hand with the high-pressure accumulator in combination.
• both the high-pressure line and the further high-pressure line open into the said cavity, so that both lines are supplied with fuel flowing through the flow restrictor.
• the further high-pressure line is designed as a resonator line, which is connected to the high-pressure accumulator via a resonator throttle.
• the fluid connection of the flow restrictor to the two high-pressure lines can also take place in such a way that the high-pressure line and the additional high-pressure line are connected to the flow restrictor via a bore intersection formed in the flow restrictor component.
• This embodiment is particularly advantageous for sidefeed injectors, where it is necessary that when closing the flow restrictor no amount of fuel directly from the side fuel inlet to the injector (bypass of the flow restrictor) can flow.
• connection of the fuel supply to the high-pressure accumulator is preferably such that the injector has a lateral connection for the fuel supply, which communicates with an inlet bore, whose first section is formed in the holding body and whose second section is the
• Flow restrictor axially interspersed.
• a bypass of the flow restrictor is preferably prevented in that the flow restrictor component on the end face facing the holding body has a planar second sealing surface which cooperates with the planar end face of the holding body.
• the design of the flow restrictor as a separate component increases the flexibility in its structural design.
• the flow restrictor a housing with a high-pressure accumulator-side housing inlet and a holder body side housing outlet, a longitudinally displaceable in a chamber of the housing between a starting position and an end position and against the flow direction spring-biased closing member, which has at least one throttle having a channel Housing inlet and housing outlet connects hydraulically with each other and further controls a flow connection between the housing inlet and the housing outlet includes.
• a retaining ring fixed in the flow restrictor component defines the starting position of the closing member.
• the invention further relates to the flow restrictor for use in the injector according to the invention, comprising a flow restrictor with a high pressure accumulator side inlet and a holder side outlet, a longitudinally displaceable in a chamber between a starting position and an end position and spring biased against the flow direction closing member having at least one throttle having Channel the inlet and outlet which hydraulically connects and which further controls a flow connection between the inlet and the outlet.
• the flow restrictor member is characterized by having a first inlet side axial portion and a second outlet side axial portion, the second portion having a larger diameter than the first portion, and the second portion having a tapered first sealing surface on a shoulder has on the opposite end face a second sealing surface which is in each case pressable against a mating surface.
• the arrangement of the sealing surfaces on the enlarged diameter formed second section ensures that the component between the holder body and the storage tube can be inserted and fixed by the screwing of the holding body and storage tube.
• the first section protrudes into the space of the high-pressure accumulator and is acted upon by the fuel pressure.
• a preferred development provides in this case that the inner diameter of the first sealing surface is at a radial distance from the outer periphery of the first portion.
• FIG. 1 shows the schematic structure of an injector of a modular common rail fuel injection system according to the prior art
• FIG. 2 shows a detailed view of the injector in region II of FIG. 1 in a first embodiment
• FIG. 3 shows a detailed view of the injector in a second embodiment
• Fig. 4 is a detail view of the injector in a third embodiment
• Fig. 5 is a detail view of the injector in a fourth embodiment.
• an injector 1 having an injection nozzle 2, a throttle plate 3, a valve plate 4, a holding body 5 and a high-pressure accumulator 6, wherein a screwed to the holding body 5 nozzle retaining nut 7, the injection nozzle 2, the throttle plate. 3 and the valve plate 4 holds together.
• the solenoid valve 13 is closed, so that high-pressure fuel from the high-pressure accumulator 6 via the high-pressure line 8, the cross-connection 9 and the inlet throttle 10 flows into the control chamber 11 of the injection nozzle 2, the outflow from the control chamber 11 via the outlet throttle 12 but at the valve seat of the solenoid valve 13 is blocked.
• a resonator 20 may be arranged with a high-pressure memory-side resonator choke 21, with which occurring pressure peaks can be lowered more quickly.
• the fuel supply can take place via a high-pressure port 23 arranged laterally on the injector 1, in particular on the holding body 5, and an inlet bore 24 leading to the high-pressure accumulator 6 (sidefeed injector).
• FIGS. 2 to 5 show a view of the detail X of FIG. 1 with the flow restrictor arranged between the storage tube 25, the high-pressure accumulator 6 and the holding body 5.
• the embodiments according to FIGS. 2 to 5 have in common that the flow regulator is formed in a separate flow restrictor component 26.
• the flow restrictor member 26 has a first axial portion 27 and a second axial portion 28, the second axial portion 28 having a larger outer diameter than the first axial portion 27 axial portion 28, the flow restrictor 26 has a shoulder with a tapered first sealing surface 29 which cooperates with a formed on a shoulder 30 of the storage tube 25 conical mating sealing surface.
• the shoulder 30 of the storage tube 25 is connected via an annular groove-like recess 31 with a thinner walled, provided with an internal thread 33 portion 32 of the storage tube 25.
• the flow restrictor 26 is inserted between the holding body 5 and the storage tube 25 and fixed by the screw connection of these two components. In this case, the flow restrictor 26 is secured by means of pins 34 against rotation.
• the seal to the holding body 5 takes place in the embodiment according to FIGS. 2, 3 and 5 via a flat sealing point, which is formed by a plane formed on the holding body 5 facing end face plane sealing surface, which cooperates with the flat end face of the holding body 5.
• the flow restrictor member 26 has an inlet 36 and an outlet 37.
• a displaceably guided in the axial direction piston 39 is arranged, which is pressed by means of the compression spring 40 against the retaining ring 41.
• the piston 39 has a blind hole 42, which communicates on the one hand with the inlet 36 and on the other hand via a throttle bore 43 with the outlet 37.
• the amount of injection is removed from the chamber 38.
• the piston 39 moves against the spring force in the direction of the lower sealing seat 44, without, however, reaching it.
• the compression spring 40 pushes the piston 39 back to the starting position.
• the chamber 38 is in this case filled via the throttle 43 again.
• the piston 39 moves so far that the sealing seat 44 is reached and the injection is terminated.
• the throttle 43 creates a pressure loss between the present in the blind hole 42 fuel and the chamber 38.
• a defined throttle flow is exceeded, the piston 39 moves against the spring force in the direction of the lower sealing seat 44 and thus ends the injection.
• a single high-pressure line 8 is provided, which extends through the holding body 5.
• the fuel passing through the flow restrictor 26 passes directly into the high-pressure line 8 via a bore section 48.
• a further high-pressure line 20 which is designed as a resonator line, is arranged parallel to the high-pressure line 8 in the holding body 5 and communicates with the fuel supply via a resonator throttle 21.
• the two high-pressure lines 8 and 20 are by a in the
• Flow restrictor 26 can be made to the holding body 5 in Topfeed injectors via a conical seal 46.
• the pins 34 can be omitted for the rotation.
• the conical sealing surfaces forming the conical seal 46 delimit a hollow space 47 into which, on the one hand, the outlet 37 and, on the other hand, the high-pressure lines 8 and 20 open.
• FIG. 5 is a sidefeed injector, wherein the fuel via the inlet bore 24 from the holding body 5 via the
• Flow restrictor 26 is guided in the high-pressure accumulator 6.
• the inlet bore 24 opens in this case via a storage throttle 49 in the high-pressure accumulator. 6

Landscapes

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

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=48083160

Family Applications (1)

Country Status (5)

Families Citing this family (3)

Citations (4)

Family Cites Families (2)

• 2012
  • 2012-04-10 AT ATA424/2012A patent/AT512277B1/de active
• 2013
  • 2013-04-08 KR KR1020147028307A patent/KR102049218B1/ko active IP Right Grant
  • 2013-04-08 JP JP2015503898A patent/JP5936764B2/ja active Active
  • 2013-04-08 EP EP13715200.5A patent/EP2836696B1/de active Active
  • 2013-04-08 WO PCT/EP2013/057268 patent/WO2013153010A1/de active Application Filing

Patent Citations (4)

Also Published As

Similar Documents

Legal Events