EP3014096B1 - Method for producing injectors, in particular fuel injectors, and injector - Google Patents

Description

The invention relates to a method for producing a plurality of injectors, in particular a plurality of fuel injectors for direct injection systems of motor vehicles. Furthermore, the invention relates to a method for pairing at least two injectors and to a method for producing an injector. Furthermore, the invention relates to an injector, in particular a fuel injector for a direct injection system of an internal combustion engine.

Increasingly stringent statutory regulations regarding permissible pollutant emissions from internal combustion engines for motor vehicles make it necessary to achieve improved mixture preparation in the cylinders of internal combustion engines by means of fuel injectors. In current fuel injectors, injection of fuel is controlled by means of a nozzle needle which is slidably mounted in the fuel injector and opens or closes an opening cross-section or one or a plurality of spray holes of a nozzle assembly of the fuel injector depending on its stroke. A control of the nozzle needle, for example, by means of a piezoelectric actuator, which actuates the nozzle needle hydraulically or mechanically.

In order to reduce the pollutant emissions of the internal combustion engine and to keep its consumption as low as possible, it is desirable to achieve the best possible combustion within the cylinder of the internal combustion engine. For good process control or control / regulation of combustion in the cylinders, it is necessary to be able to dose the fuel to be injected volumetrically and in terms of time as accurately as possible in order to maximize combustion and / or as complete regeneration of a particulate filter as possible at any given time To achieve motor vehicle, there torque requirements of the internal combustion engine are converted into injection quantities, which in turn correlate with an injection period as a function of an injection pressure, a stroke of the nozzle needle and a geometry of the fuel injector.

A deviation of an actual injection quantity from a desired injection quantity of a fuel injector always has negative effects on combustion, ie the resulting pollutant emissions, and usually also consumption of the internal combustion engine. Especially for direct-injection fuel injectors, high demands are placed on accuracy of the injection quantities and stability of a steel image under all operating conditions and over the entire service life of the fuel injector. This is even more true with regard to small injection quantities, in a multiple injection mode with the short injection intervals associated therewith and / or in a partial stroke mode of a nozzle needle.

An injection nozzle of the fuel injector is driven by the nozzle needle, which can be driven, for example, by means of a servovalve operable by a piezoactuator. Such a hydraulically indirectly driven nozzle needle is state of the art. - The nozzle needle can also be controlled directly without a detour via a servo valve. In such a fuel injector, a coupling of a movement of the piezoelectric actuator and subsequently a movement of the nozzle needle can take place hydraulically directly, which brings about significant advantages. The same requirements apply to such hydraulically directly driven fuel injectors as to injectors which can be controlled by means of a servo valve. However, a hydraulic direct drive results in further advantageous properties of the fuel injectors.

From the DE 10 2011 079 468 A1 For example, a method of manufacturing an injector is known. In this method, two mechanical games relevant to injection quantities, leakage quantities and / or pressure differentials of the injector are paired with each other. This is a mating game a module of the injector a Matching game paired with another assembly of the injector. Thus, two mechanical games relevant to leakage quantities of the injector are paired with each other.

From the DE 10 2009 027 103 A1 For example, an injector is known in which two mechanical games that are relevant for an injection quantity of the injector, in this case the inlet gaps, are paired with one another.

It is an object of the invention, in particular for hydraulically directly driven injectors, to provide an improved production method with a criterion for a vast majority of the injectors. Furthermore, it is an object of the invention to provide an improved method for pairing at least
specify two injectors.

The object of the invention is achieved by a method for producing injectors, in particular fuel injectors for direct injection systems of motor vehicles, according to claim 1. Advantageous developments, additional features and / or advantages of the invention will become apparent from the dependent claims and the following description of the invention.

In order to ensure the smallest possible scatter in the injection quantities in operating or test points and / or areas at the injectors among each other at least in their new states in an injector with hydraulically directly actuated nozzle needle, it has been found a balance of the leakage currents or quantities and / or to set specific pressure differences within a nozzle and / or control assembly of a single injector as accurately as possible and / or via a plurality of injectors, for. As the injectors of a single injection system, or a variety of injectors, z. As the injectors of a lot, as accurately as possible to comply, so adjust, the manufacturing tolerances must not be too low, so as not to be too high the cost.

In the first method, a method for producing injectors, so z. B. a production lot of
Injectors, the injectors are adjusted or manufactured such that a total leakage and / or a pressure difference at a transmission pin of the respective injector across a possibly vast majority or a vast plurality of injectors across approximately, mainly or substantially constant. In this case, the injectors may be designed such that the total leakage and / or the pressure differences at the transmission pins of the injectors is a measure of the injection quantities and / or accuracies of the injectors.

Ie. is a criterion for making a plurality of injectors, for. B. in addition to reproducible injection quantities whose approximate, mainly or substantially mutually constant total leaks, z. As total leakage currents and / or quantities, and / or their approximate, mainly or substantially mutually constant pressure differences at their transmission pins. This criterion can, for. B. be a secondary condition to the injection quantities. In this case, it is preferable if the total leaks and / or pressure differences which are as constant as possible with one another are valid for a plurality of operating or test points and / or regions of the injectors.

In further methods for pairing at least two injectors, a criterion for pairing the injectors is a total leakage and / or pressure differential at a transfer pin of the respective injector. In this case, the injectors can be paired such that the total leaks and / or the pressure differences at the transmission pins of the injectors are mainly, substantially or almost the same. Ie. means for injecting fuel, e.g. As an injection system for an internal combustion engine, has at least two injectors. According to the invention, the injectors are selected in such a way that, in at least one operating point or test point and / or region, they are mainly, substantially or virtually one another
have the same total leakage and / or pressure difference at their transmission pins.

The terms "approximately", "mainly", "substantially" or "nearly" that relate the corresponding measured values and / or calculated values for the total leakage and / or pressure differences should be able to be classified in the following descending order: (distinct) different ( at least ten or one tenth), approximately, approximately, principally (not more than twice or less than half, respectively), substantially, nearly, identical (except for one or two common decimal places). The respective previous term, ie z. For example, the term "near", is intended to encompass the following term, that is, in this example, the term "identical".

In the third method according to the invention, a method for producing an injector, at least two, preferably three, mechanical games relevant for injection quantities, leakage quantities and / or pressure differences of the injector, in particular pairing games, are matched, in particular paired. The successive adjustment or the pairing of the mechanical plays of the injector can take place such that a leakage inflow to a control chamber of the injector substantially or at least corresponds to a leakage outflow downstream of this control chamber. Furthermore, it is possible for a pressure difference between a nozzle space and a control space of the injector to remain substantially the same or to decrease. This can alternatively or additionally also be applied to a pressure difference between the or a control chamber and a leakage chamber of the injector.

In embodiments of the invention, a desired mating clearance of an assembly of the injector can be calculated and matched depending on a common actual mating clearance of another assembly of the injector, possibly taking into account a nominal mating clearance of the paired assembly. This can be a mechanical game two
or more other mechanical games are paired, the two or more
other mechanical games preferably also matched to each other or can be paired. This can be z. B. carried out according to the invention. Ie. it can z. B. three mechanical games matched or be paired with each other, which preferably takes place successively or in parallel.

If this happens successively, a first mechanical game is paired with an optimally optimal second game, which is then paired with the best possible third game. It is also possible to pair the second and third games together to the first game. In the latter embodiment, a z. B. too small, d. H. possibly harmful, avoid play. Of course, this is also possible in the case of the first embodiment, as long as the third game is taken into account when setting up the second game or vice versa as a secondary condition. Of course, this approach is also applicable to two, four, or more causally related mechanical games of the injector.

In further embodiments, at least one module with a paired target pairing clearance can be installed on an assembly already installed on / in a developing injector with an actual pairing clearance. Ie. An assignment of a set pairing clearance of a second assembly for the actual pairing clearance of a first assembly or of the already partially existing injector preferably follows a successive assembly of the injector. The injector can still be constructed in such a way that an already assembled component does not have to be dismantled again in order to be able to adjust or couple a respective game.

The mechanical games of a nozzle needle can z. B. in a guide of the nozzle needle, z. B. a nozzle needle sleeve, a transfer pin in an intermediate plate and / or a control piston in one
Control plate adjusted to each other or be paired. Other
Components or assemblies are also applicable. Matching or pairing of the mechanical games for an injector may be due to at least one test point and / or at least one test run for individual assemblies or assemblies or components mounted to each other. Ie. Measurements of pressures, leakages, dimensions, and / or other parameters may be determined at one or a plurality of test points and / or series of tests for a single particular assembly or for mated assemblies or components for a hypothetical injector.

In embodiments, a relevant mechanical clearance, ie an actual pairing clearance, can be determined by a gas leakage measurement, by a flow measurement, by diameter determinations and / or by shape determinations. The method can be carried out in time after a separate pre-assembly of at least two individual assemblies. The successive adjustment or pairings of the at least two individual assemblies is taken into account for a final assembly of an injector. Furthermore, the method can be carried out in a final assembly of the injector.

In the injector, at least two mechanical games relevant for injection quantities, leakage quantities and / or pressure differences of the injector, in particular mating games, are matched to one another, in particular paired with one another. The mutually adjusted or paired mechanical games, for example, a nozzle needle in a guide of the nozzle needle, z. B. a nozzle needle sleeve, a transmission pin in an intermediate plate and / or a control piston in a control plate. Preferably, the injector is free from a control valve or servo valve controlling the injection quantities of the injector. An actuator of the injector is preferably a piezoelectric actuator.

According to the invention, it is possible in a Injektormontage with a relatively low cost a good to very good, d. H. set up or produce the best possible combination of mating games for the component pairings. According to the invention, an injector / injector scattering is reduced when the injectors are mounted by coordinating function-relevant mating games for an outflowing leakage on the one hand and an incoming leakage on the other hand in a suitable manner within an assembly process of the injectors. Thus, the dispersion in a series production is reduced in relation to an injector function, and a proportion of those injectors, which do not meet required tolerances of their injection quantities, can be reduced. Thus, an expense of necessary rework can be reduced. This affects individually and in total in a reduction of the manufacturing costs.

Fig. 1

eine Längsseitenansicht eines erfindungsgemäßen Injektors für ein Common-Rail-Einspritzsystem eines Verbrennungsmotors, welche mittig und unten zentral geschnitten dargestellt ist;

Fig. 2

eine zentral geschnittene, oben und unten weggebrochen dargestellte, detaillierte Längsseitenansicht einer Steuerbaugruppe des Injektors aus Fig. 1, mit einem hydraulischen Direktantrieb einer Düsennadel;

Fig. 3

ein Ablaufdiagramm einer Ausführungsform eines erfindungsgemäßen Verfahrens zum aufeinander Abstimmen oder einander Zupaaren dreier mechanischer Spiele innerhalb einer Düsenbaugruppe des Injektors;

Fig. 4

ein zur Fig. 3 analoges Ablaufdiagramm, welches eine zweite Ausführungsform des erfindungsgemäßen Verfahrens beim aufeinander Abstimmen oder einander Zupaaren der drei mechanischen Spiele repräsentiert;

Fig. 5

ein schematisches Diagramm gemäß den Fig. 3 bzw. 4 zum Auswählen eines zweiten und dritten mechanischen Spiels aufgrund eines Istwerts eines ersten mechanischen Spiels; und

Fig. 6

ein schematisches Diagramm eines erfindungsgemäß vereinfachten Verfahrens, wobei dem Istwert des ersten mechanischen Spiels eine Summe des zweiten und dritten mechanischen Spiels zugepaart wird.

The invention is explained in more detail below with reference to embodiments with reference to the accompanying drawings. Elements or components which have an identical, univocal or analogous configuration and / or function are identified by the same reference numerals in different figures (FIG. 1) of the drawing. In the figures of the drawing show:

Fig. 1

a longitudinal side view of an injector according to the invention for a common rail injection system of an internal combustion engine, which is shown centrally and centrally cut below;

Fig. 2

a centrally cut, broken away top and bottom, detailed longitudinal side view of a control assembly of the injector Fig. 1 , with a hydraulic direct drive of a nozzle needle;

Fig. 3

a flow chart of an embodiment of a method according to the invention for matching or each other pairing three mechanical games within a nozzle assembly of the injector;

Fig. 4

one to Fig. 3 analog flow diagram, which is a second embodiment of the method according to the invention when matching or representing each other pairs of the three mechanical games;

Fig. 5

a schematic diagram according to the Fig. 3 or 4 for selecting a second and third mechanical game based on an actual value of a first mechanical game; and

Fig. 6

a schematic diagram of a simplified method according to the invention, wherein the actual value of the first mechanical game, a sum of the second and third mechanical game is paired.

The invention is explained in more detail below with reference to a piezoelectrically operated common rail diesel injector 1 for an internal combustion engine of a motor vehicle (see Fig. 1 ). However, the invention is not limited to such diesel injectors 1, but can, for. B. also be applied to pump-nozzle fuel injectors or gasoline injectors with a single or multi-part nozzle needle, and typical gasoline injectors designations can be found in the list of reference numerals. Therefore, the following is only an injector 1. An injectable fluid may be a fuel, but it is of course possible, by means of an injector according to the invention, another fluid such. As water, an oil or any other process fluid to inject. Ie. the injector according to the invention is not limited to the automotive industry.

The Fig. 1 shows the injector 1 substantially in a sectional view, wherein the injector 1 comprises a nozzle assembly 10 and an injector 40. The nozzle assembly 10 and the injector assembly 40 are fixed fluid tight to each other by means of a nozzle lock nut 60. The injector assembly 40 has an injector body 400, in which an actuator 410 is provided, which is preferably designed as a piezoelectric actuator 410. However, an electromagnetic actuator is also applicable. In the present example, the piezoelectric actuator 410 drives a one-piece, preferably integral, nozzle needle 110 hydraulically directly (see also FIG Fig. 2 ). The one-piece inwardly opening nozzle needle 110 may optionally be formed in two or more parts and / or be configured to open outwardly in the injector 1.

The injector body 400 has a high-pressure-side fluid connection (not visible) for the fuel to be injected, the fluid connection being in fluid communication with a high-pressure bore 402 formed in the injector body 400. About the high-pressure side fluid port of the injector 1 with a high-pressure fluid circuit (not shown) is hydraulically connected. The high-pressure bore 402 supplies the nozzle assembly 10 and thus a nozzle chamber 102 of the injector 1 with fuel under high pressure p _R , z. B. a so-called rail pressure p _R (common rail system). In the nozzle chamber 102, during an operation of the injector 1, there is essentially always an actual maximum or maximum pressure p ₁₀₂ = p _R.

The nozzle assembly 10 has a nozzle body 100 with at least one spray hole (not shown) in its nozzle 104 and the nozzle chamber 102, wherein the nozzle needle 110 is arranged displaceably in the nozzle chamber 102 and stored in sections. The nozzle needle 110 is pressed via an energy storage 114, preferably a nozzle needle spring 114, in the direction of its nozzle needle seat inside in the nozzle 104 in order to be securely closed even in an electrically non-energized state of the piezoelectric actuator 410. Depending on an activation of the piezoactuator 410, the nozzle needle 110 is either pressed into its nozzle needle seat or moves away from the nozzle needle seat, as a result of which fuel can be injected.

The nozzle assembly 10 further accommodates a control assembly 20 located between the nozzle body 100 and the injector assembly 40 for actuating the nozzle needle 110 based on an elongation of the piezoactuator 410 in response to its energy E or charge E, that is, an electrical voltage applied thereto. The Fig. 2 shows the components of the control assembly 20 for a direct hydraulic coupling of an elongation movement of the piezoelectric actuator 410 and thereby caused movement of the nozzle needle 110. The piezoelectric actuator 410 has for this purpose Bottom plate 412 with a preferably integral Betätigungsfortsatz that is in direct mechanical contact with a transmission pin 212, which is fitted and / or paired with a very small clearance in a pin hole 211 an intermediate plate 210 of the control assembly 20.

A mating clearance of the transmission pin 212 in the pin bore 211 is chosen to be so small, e.g. B. about 1um that even at a high rail pressure p _R of up to over 2,500bar only a small fuel leakage L at the transfer pin 212 occurs (drops). The pin bore 211 connects a first control chamber 22, which is also referred to as a piston control chamber 22 and in which a slightly lower fuel pressure than the actual rail pressure p _R > p ₂₂ prevails, with a leakage chamber 42 of the injector 1, preferably with an ambient pressure p _∞ is in permanent fluid communication. The leakage space 42 is preferably in fluid communication with a leakage port 404 of the injector 1. At the transfer pin 212, there is a large pressure difference Δp = p ₂₂ -p _∞ the z. B. in the above assumed 2,500bar maximum pressure and a closed injector 1 may well exceed a value of 2,450 bar.

The first control chamber 22 communicates with a second control chamber 12, the so-called needle control chamber 12, preferably in permanent fluid communication through a connecting bore 17 through a section of the control assembly 20. In the second control chamber 12, just as in the first control chamber 22, a slightly lower fuel pressure prevails than rail pressure p _R > p ₁₂ , wherein the pressures p ₁₂ ≈ / = p ₂₂ in the control chambers 12, 22 are substantially the same, at least when the injector 1 is closed. Overall, p _∞ = p ₄₂ << p ₁₂ ≈ / = p ₂₂ ≤ p _R = p ₁₀₂ . In the connecting bore 17, a damping throttle 232 designed as a fluid throttle 232 may be provided, which is preferably formed in a separate plate 230 of the control assembly 20.

A stroke (elongation) of the piezoactuator 410 is transmitted by means of the transfer pin 212, which is also referred to as leakage pin 212, to a control piston 222, which enters a piston bore 221 a control plate 220 of the control module 20 fitted and / or paired. The transmission pin 212 engages on / in the first control chamber 22 at an upper end face 223 of the control piston 222, wherein the control piston 222 is supported on its lower end face 224 by an energy storage device 225 preferably designed as a spiral spring 225. At the lower end face 224 of the control piston 222 there is preferably substantially a rail pressure p _R , this end face 224 preferably being in permanent fluid communication with the nozzle chamber 102.

The second control chamber 12 is formed by an end face of an upper longitudinal end portion 112 of the nozzle needle 110, the so-called needle piston 112, a wall of a needle bore 121 in an upper guide 120 of the nozzle needle 110, preferably a nozzle needle sleeve 120, and a lower end face of the plate 230. The needle piston 112 of the nozzle needle 110 is facing away from a nozzle needle tip of the nozzle needle 110 or the nozzle 104 of the nozzle body 100. - This embodiment of the injector 1 set forth briefly is of course not restrictive to understand. The invention is applicable to a variety of other embodiments of injectors, as long as a leakage L and / or a pressure drop Δp within the injector can be used as a measure of the quality of the injector.

Due to the movement of the control piston 222 due to a stroke of the piezoelectric actuator 410, a pressure drop Δp _{22 is} generated in the first control chamber ₂₂ , which is transmitted via the connecting bore 17 and possibly delayed by the optional fluid throttle 232 to the upper end face of the nozzle needle 110 in the second control chamber 12 , When this pressure drop Δp ₁₂ ≈ / = Δp ₂₂ exceeds a certain value, the nozzle needle 110 opens and an injection of fuel can occur. A stroke of the nozzle needle 110 can be controlled or controlled via an opening of the nozzle needle 110 via a variation of the stroke of the piezoelectric actuator 410. The stroke of the piezoelectric actuator 410 can be varied via a variation of its intrinsic electrical energy E, that is, the voltage applied to it.

When unloading the piezoelectric actuator 410, this and the acting on / on the lower end face 224 of the control piston 222 rail pressure p _R from the nozzle chamber 102 of the nozzle body 100 together with the also acting in this direction spring force of the spring element 225, the control piston 222 is in its initial position pushed back, which is determined by a position of the transmission pin 212. As a result, the nozzle needle 110 is displaced back to its closed position corresponding to the movement of the piezoactuator 410, and the injection of fuel is stopped. The nozzle needle spring 114 securely holds the nozzle needle 110 closed / seated in the nozzle 104 of the nozzle body 100.

In the present case, the injector 1 has three internal leakages L or leakage flows L or quantities L. First, a leakage L ₁₁₂ at the nozzle needle 110 and the needle piston 112, ie between the nozzle needle sleeve 120 and the needle piston 112 through the needle bore 121 therethrough. This is a leakage inflow L ₁₁₂ in the second control chamber 12 directly downstream of the nozzle needle 110. And as a second leakage L ₂₂₂ a leakage L ₂₂₂ on the control piston 222, ie between the control plate 220 and the control piston 222 through the piston bore 211 therethrough. This is a leakage inflow L ₂₂₂ in the first control chamber 22 immediately downstream of the control piston 222. As a leakage outflow L ₂₁₂ and a total leakage L ₂₁₂ of the injector 1 results in a leakage L ₂₁₂ at the transmission spin 212, that is, between the intermediate plate 210 and the transmission Spin 212 through the pin bore 211 into the leakage space 42.

A leakage balance of the inner leakages L ₁₂₂ , L ₂₁₂ , L _{222 of} the injector 1 with respect to the transfer pin 212 results to L ₂₁₂ = L ₁₂₂ + L ₂₂₂ over a longer period of time. Leakage L is always the result of a pressure difference Δp of the fuel at / in a component or on / in an assembly. According to the invention, leakages L and / or pressure differences Δp within the nozzle assembly 10 and / or the control assembly 20 are paired; ie corresponding components and / or assemblies are paired in the sense of a read pairing, which in the The following is explained in more detail. In particular, the components which are preferably themselves fitted and / or paired with each other: transmission pin 212 and intermediate plate 210, control piston 222 and control plate 220, and nozzle needle 110 or needle piston 112 and nozzle needle sleeve 120 form three such assemblies within the meaning of the invention.

When the nozzle needle 110 is closed, the leakage L ₂₁₂ at the transfer pin 212 - the fuel pressure in a downstream leakage path toward the leakage port 404 corresponds approximately to the ambient pressure p _∞ (see above) - also results in an outflow of fuel from the first control chamber 22 which leads to a pressure drop Δp in the first control chamber 22 to the pressure p ₂₂ . This leakage discharge L ₂₁₂ is compensated by a leakage inflow L ₁₁₂ + L ₂₂₂ in the nozzle needle sleeve 120 and on the control piston 222. For this leakage inflow L ₁₁₂ + L _222, a pressure difference Δp = p _R -p ₁₂ or Δp = p _R -p ₂₂ between the pressure p ₁₂ , p ₂₂ in the control chamber 12, 22 and the rail pressure p _R acts as a driving force. Therefore, according to the invention, the control piston 222 is fitted into the piston bore 221 and an upper diameter of the nozzle needle 110 into the nozzle needle sleeve 120 with a mating clearance to be defined.

Due to the above-described leakage balance L ₂₁₂ = L ₁₂₂ + L ₂₂₂ results in a pressure difference Ap between the rail pressure p _R and a pressure p ₁₂ , p ₂₂ in the respective control chamber 12, 22 directly from the transmission pin 212, the control piston 222 and in the Düsennadelhülse 120 games set, especially mating games of read pairings. As a result, such an initial pressure difference Δp has a reduction of a firing force on the nozzle needle 110 and therefore influences an opening and closing time of the injector 1. The three games have an influence on a metering accuracy of the injector 1 To reduce influence on the injection quantities of the injector 1 and to achieve low injector / injector scattering, according to the invention, a combination of the mating games before or during an assembly of the injectors 1 optimized, ie improved. This is explained by way of example below.

The outflowing leakage L ₂₁₂ is determined substantially via the mating clearance between the transfer pin 212 and the intermediate plate 210. Since it is currently very complex, geometric tolerances of the pin hole 211 in the intermediate plate 210 and the transfer pin 212 to detect sufficiently accurate, z. B. by means of a gas leakage measurement during assembly, a pre-assembly and / or a test assembly, an integral value with respect to an expected leakage discharge L ₂₁₂ can be determined. This expected value of the leakage drain L ₂₁₂ sets set values Δd _{soll of} the mating clearances for the control piston 222 in the control plate 220 and the needle piston 112 in the nozzle needle sleeve 120.

In a subsequent assembly step, the control piston 222 of the control plate 220 and the piston bore 211 is paired. A resulting Istpaarungsspiel .DELTA.d _is can from the target mating game .DELTA.d _will vary within an allowable tolerance. In order to achieve a target control chamber pressure Δp ₁₂ ≈ / = Δp ₂₂ as precisely as possible to achieve a leakage equilibrium (leakage L ₂₁₂ = sum of the inlets L ₁₂₂ , L ₂₂₂ ) is a nominal value Δd _{soll of} the mating clearance for the nozzle needle 110 in the nozzle needle sleeve 120 in a function of the actual pairing clearance .DELTA.d _, the control piston 222 in the control plate 220 is to be selected.

A flow of fuel through an ideal annular gap at a given pressure difference Δp and viscosity of the fuel is proportional to the diameter of an annular gap multiplied by the cube of the gap divided by a gap length. Eccentricity of backlashes may affect a resulting fuel flow rate in the range of a factor of 0.5 to 2.5. If necessary, this parameter can be z. B. be taken into account on a statistical basis. Based on this relationship can be in dependence of a deviation of the game of the control piston 222 from the setpoint .DELTA.d _should the Desired value Δd _should match the mating clearance of the nozzle needle sleeve 120. the nozzle needle 110 is determined, ie calculated.

mit den Variablen:

l₁₂₀

einer Länge der Düsennadelhülse 120;

d₂₂₂

einem Durchmesser des Steuerkolbens 222;

l₂₂₂

einer Länge des Steuerkolbens 222;

d₁₂₀

einem Innendurchmesser der Düsennadelhülse 120;

Δd_{222_nom}

einem Nominalpaarungsspiel des Steuerkolbens 222, also des Steuerkolbens 222 in der Steuerplatte 220 bzw. deren Kolbenbohrung 221;

Δd_{222_ist}

einem Istpaarungsspiel des Steuerkolbens 222, also des Steuerkolbens 222 in der Steuerplatte 220 bzw. deren Kolbenbohrung 221; und

Δd_{120_nom}

einem Nominalpaarungsspiel der Düsennadelhülse 120, also der Düsennadel 110 bzw. deren Nadelkolbens 112 in der Düsennadelhülse 120 bzw. deren Nadelbohrung 121.

The result is the following formula for the desired pairing clearance Δd _{120_ of} the nozzle needle _sleeve 120, that is to say the nozzle needle 110 or its needle piston 112 in the nozzle needle sleeve 120 or the needle bore 121: $$\mathrm{\Delta }{\mathrm{d}}_{120-\mathrm{should}}=\sqrt[3]{\frac{{\mathrm{<figure-callout\; id="120"\; label="l"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">l</figure-callout>}}_{120}\cdot {\mathrm{d}}_{222}}{{\mathrm{<figure-callout\; id="222"\; label="l"\; filenames="imgf0002.png,imgf0003.png"\; state="\{\{state\}\}">l</figure-callout>}}_{222}\cdot {\mathrm{<figure-callout\; id="120"\; label="d"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">d</figure-callout>}}_{120}}\cdot \left(\mathrm{<figure-callout\; id="222"\; label="\Delta \; d"\; filenames="imgf0002.png,imgf0003.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{\mathrm{d}}_{}^{}{\mathrm{}}_{222\_\mathrm{nom}}^3-\mathrm{<figure-callout\; id="222"\; label="\Delta \; d"\; filenames="imgf0002.png,imgf0003.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{\mathrm{d}}_{}^{}{\mathrm{}}_{222\_\mathrm{is}}^3\right)+\mathrm{<figure-callout\; id="120"\; label="\Delta \; d"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{\mathrm{d}}_{}^{}{\mathrm{}}_{120\_\mathrm{<figure-callout\; id="3"\; label="nom"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">nom</figure-callout>}}^3}$$

with the variables:

l ₁₂₀

a length of the nozzle needle sleeve 120;

d ₂₂₂

a diameter of the control piston 222;

₂₂₂

a length of the control piston 222;

d ₁₂₀

an inner diameter of the nozzle needle sleeve 120;

Δd _{222_nom}

a nominal mating clearance of the control piston 222, that is the control piston 222 in the control plate 220 or its piston bore 221;

Δd _{222_act}

a Istpaarungsspiel the control piston 222, so the control piston 222 in the control plate 220 and the piston bore 221; and

Δd _{120_nom}

a Nominalpaarungsspiel the nozzle needle sleeve 120, so the nozzle needle 110 and the needle piston 112 in the nozzle needle sleeve 120 and the needle bore 121st

In Fig. 3 this method according to the invention is shown in the form of a flow chart. The applied inventive method can also be applied in a reverse order, so that the play on the nozzle needle sleeve 120 (other or second mechanical game) is used as an output parameter and a game to be adjusted on the control piston 222 (other or third mechanical game) is calculated from it what is in the flowchart in the Fig. 4 is clarified. The Fig. 5 shows the one Fig. 3 and Fig. 4 is an analogous diagram for selecting the second and third mechanical play, respectively, based on the actual value of a first mechanical clearance at the transfer pin 212 (mechanical output clearance). - In principle it is possible, any of the apply three games as the original game and the other two games, again in any order, according to the invention set, so to pair the relevant modules.

Furthermore, a simplification of the calculation according to the invention can be carried out, for example, in that in dependence of the Istpaarungsspiels .DELTA.d _is the transfer pins 212 in the intermediate plate 210 and the measurement value from the gas leakage measurement, a target value .DELTA.d _{is intended} for a sum (the Paarungsspiele) from the mating game on the control piston 222 and the mating clearance in the nozzle needle sleeve 120 is determined. The set pairing clearance Δd _soll for the nozzle needle 110 in the nozzle needle sleeve 120 results from a difference between the specified sum of the pairing games and a determined Istpaarungsspiel Δd _is the control piston 222 in the control plate 220. Thus, it can also be prevented that both mating games at a tolerance upper or lower limit, which causes unwanted effects.

In Fig. 6 this method is shown schematically. Again, an order between the mating clearance of the control piston 222 in the piston bore 221 and the mating clearance of the needle piston 112 in the nozzle needle sleeve 120 can be reversed. - Since in particular too small mating games for the incoming leakage L ₁₂₂ + L ₂₂₂ impact on deviations in the injection quantities of the injector 1, a further simplified inventive criterion can be applied in the form that the sum of the mating games on the control piston 222 and in the Nozzle needle sleeve 120 must be greater than a setpoint value (eg, depending on a result of the above-described gas leakage measurement at the transmission pin 212). Ie. there is only a correction if this setpoint is exceeded; z. Example, by providing a nozzle assembly 10 with a comparatively large mating clearance between the nozzle needle 110 and the needle piston 112 and the nozzle needle sleeve 120th

According to the invention, a pairing of at least two modules of the injector 1 to each other takes place, wherein at least one This assembly itself is a consequence of a pairing of two components of this assembly. Thus pairings are paired, ie paired components, namely those of the first assembly, are paired into paired components, namely those of the second assembly, in the form that the pairing of the second assembly is established, ie paired, with respect to the pairing of the first assembly becomes. All pairings can be considered as read pairing. These pairings act in fluid-mechanically at least temporarily in the injector 1 such that a flow of fuel through the first "pairing" has an influence on a flow of the fuel through the second "pairing".

Of course, the pairing of pairs can also be applied to three (see above) or more assemblies, which may consist of paired components. Furthermore, it is also possible according to the invention, instead of an assembly, to pair a single component, which in such a case can be referred to as an assembly, to an assembly of already paired components. In principle, an order of pairing assemblies, that is, pairing pairings, may be arbitrary, with an output assembly preferably paired as nominally as possible with respect to their fuel flow. The output module is preferably that module which is mounted on the injector 1 as the first of the modules zuzupaarenden.

A preferred output module is therefore the transmission pin 212 in the pin hole 211 of the intermediate plate 210. The further Zupaaren is then preferably a progressive structure of the injector 1 in the form that already mounted assemblies preferably no longer need to be dismantled. A respective partial injector (1) determines, on the basis of its measured, calculated and / or estimated leakage behavior, a pair of the assembly (s) or components (n) still to be mounted. Other orders of Zupaarens or the assembly of the injector 1 are of course applicable.

LIST OF REFERENCE NUMBERS

1

Injector, Fuel Injector, Common Rail / Piezo Fuel Injector, Injector Fuel Injector, Diesel Injector, Gasoline Injector

10

Nozzle assembly, injection module

12

second control room, needle control room, p ₁₂

17

Connection bore / pipe between first 22 and second control room 12

20

Control assembly of the nozzle assembly 10 for driving the nozzle needle 110th

22

first control chamber, piston control chamber, p ₂₂

40

Injector assembly, drive module

42

Leakage space (total leakage L ₂₁₂ preferably only at the transmission pin 212), p ₄₂

60

Nozzle tension nut, valve clamping nut

100

nozzle body

102

Nozzle space, nozzle bore, p ₁₀₂

104

Nozzle, injector, valve

110

Nozzle needle, injection needle, possibly two- / multi-part, opening inwards or outwards

112

upper longitudinal end portion of the nozzle needle 110, needle piston, the nozzle 104 and a valve of the injector 1 facing away

114

Energy storage, spring element, coil spring, compression spring, nozzle needle spring, injection needle spring for biasing the nozzle needle 110th

120

(upper) guide of the nozzle needle 110, nozzle needle sleeve

121

needle bore

210

intermediate plate

211

lingually

212

Transfer pin, leakage pin, Δp (p ₂₂ -p _∞ ) high

220

control plate

221

piston bore

222

spool

223

upper end surface control piston 222, limitation of the piston control chamber 22, p ₂₂

224

lower end face of the control piston 222, p _R

225

Energy storage, spring element, coil spring, compression spring for biasing the control piston 222

230

plate

232

Fluid throttle, damping throttle

400

Injector body, injector housing with high pressure line 402 to the nozzle chamber 102nd

402

High pressure bore / conduit in fluid communication with nozzle space 102 through control assembly 20, p _R

404

Leckageanschuss

410

Actuator, piezo actuator, electromagnetic actuator

412

Bottom plate of the actuator 410 preferably with integral actuating extension for the transfer pin 212

L

(Fuel) leakage, leakage flow, leakage quantity (general)

L ₁₁₂

Leakage (flow / amount) at the nozzle needle 110 (needle piston 112), ie between the nozzle needle sleeve 120 and nozzle needle 110 through needle bore 121 through, leakage inflow; Correction by mechanical play (other mechanical play)

L ₂₁₂

Leakage (-strom / -menge) at the transmission pin 212, ie between intermediate plate 210 and transmission pin 212 through pin bore 211 therethrough, leakage balance: L ₂₁₂ = L ₁₂₂ + L ₂₂₂ , leakage discharge, total leakage; due to mechanical output play (mechanical play)

L ₂₂₂

Leakage (flow / amount) on the control piston 222, ie between the control plate 220 and the control piston 222 through the piston bore 211, leakage flow; Correction by mechanical play (other mechanical play)

Ap

Pressure drop, pressure difference (general)

p _∞

Ambient pressure with p _∞ = p ₄₂ << p ₁₂ ≈ / = p ₂₂ ≤ p _R = p ₁₀₂

p ₁₂

Pressure in needle control chamber 12, z. B. p ₁₂ = p _R -25bar to p _R -300bar

p ₂₂

Pressure in the piston control chamber 22, z. B. p ₁₂ = p _R -25bar to p _R -300bar

p ₄₂

Pressure in the leakage chamber 42, p ₄₂ = p _∞

p _R

Rail pressure, current maximum or maximum pressure in the injector 1 to over 2,500 bar, p _R = p ₁₀₂

Δd _should

Matchmaking game (general)

Δd _is

Matching game (general)

Δd _nom

Nominal Matching Game (general)

Δd _{120_soll}

Sollpaarungsspiel nozzle needle sleeve 120, so the nozzle needle 110 in the nozzle needle sleeve 120 and the needle bore 121st

Δd _{120_nom}

Nominalpaarungsspiel nozzle needle sleeve 120, so the nozzle needle 110 in the nozzle needle sleeve 120 and the needle bore 121st

Δd _{222_act}

Istpaarungsspiel control piston 222, so the control piston 222 in the control plate 220 and the piston bore 221st

Ad _{222_nom}

Nominalpaarungsspiel control piston 222, so the control piston 222 in the control plate 220 and the piston bore 221st

d ₁₂₀

(Inner) diameter of the nozzle needle sleeve 120

l ₁₂₀

Length of the nozzle needle sleeve 120

d ₂₂₂

Diameter of the control piston 222

₂₂₂

Length of the control piston 222

e

Energy, charge, corresponds to the voltage applied to the actuator 410

Claims (7)

1. Method for producing an injector, in particular a fuel injector (1) for a direct injection system of an internal combustion engine, characterized in that
   at least two instances of mechanical play (110/120, 210/212, 220/222), in particular instances of pairing play (110/120, 210/212, 220/222) which are relevant to injection quantities, leakage quantities (L₁₁₂, L₂₁₂, L₂₂₂) and/or pressure differences (Δp = p_R-p₁₂ ≈/= Δp = p_R-p₂₂) of the injector (1) are paired with one another in that an instance of setpoint pairing play (Δd_setp) of an assembly (110, 120; 210, 212; 220, 222) of the injector (1) is calculated from an instance of measured actual pairing play (Δd_act) of another assembly (110, 120; 210, 212; 220, 222) of the injector (1) and is paired therewith as a function thereof, wherein, if appropriate, an instance of nominal pairing play (Δd_nom) of the paired assembly (110, 120; 210, 212; 220, 222) is taken into account.
2. Production method according to the preceding claim, characterized in that the pairing of the instances of mechanical play (110/120, 210/212, 220/222) of the injector (1) with one another is carried out in such a way that
   a leakage inflow (L₁₁₂, L₂₂₂) to a control space (22) of the injector (1) corresponds essentially or at least to a leakage outflow (L₂₁₂) downstream of the control space (22), and/or
   a pressure difference (Δp = p_R-p₁₂ ≈/= Δp = p_R-p₂₂) between a nozzle space (102, p_R) and a control space (12, p₁₂; 22, p₂₂) of the injector (1) remains essentially the same or decreases.
3. Production method according to one of the preceding claims, characterized in that an instance of mechanical play (110/120, 210/212, 220/222) has two other instances of mechanical play (110/120, 210/212, 220/222) paired with it, wherein the two other instances of mechanical play (110/120, 210/212, 220/222) are preferably also paired with one another.
4. Production method according to one of the preceding claims, characterized in that in addition to an assembly (110, 120; 210, 212; 220, 222) which is already installed on/in an existing injector (1) and which has actual pairing play Δd_act), it is possible to install at least one assembly (110, 120; 210, 212; 220, 222) which has paired setpoint pairing play (Δd_setup), on/in the existing injector (1).
5. Production method according to one of the preceding claims, characterized in that the instances of mechanical play (110/120, 210/212, 220/222) of a nozzle needle (110) in a guide (120) of the nozzle needle (110), a transmission pin (212) in an intermediate plate (210) and/or a control piston (222) in a control plate (220) are paired with one another.
6. Production method according to one of the preceding claims, characterized in that the pairing of the instances of mechanical play (110/120, 210/212, 220/222) for an injector (1) is carried out on the basis of at least one test point and/or at least one test series for individual assemblies (110,120;210,212;220,222) or components which are mounted one against the other.
7. Production method according to one of the preceding claims, characterized in that:

   • a respective instance of mechanical play (110/120, 210/212, 220/222) is determined by measuring the gas leakage, by measuring the throughflow rate, by determining the diameter and/or by determining the shape;

   • the method is carried out chronologically after separate premounting of at least two individual assemblies (110, 120; 210, 212; 220, 222);

   • the pairing of the at least two individual assemblies (110, 120; 210, 212; 220, 222) is taken into account for final assembly of an injector (1);

   • the method is carried out when final assembly of the injector (1) takes place; and/or

   • the injector (1) is embodied according to one of Claims 13 to 15.

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