EP3990770A1

EP3990770A1 - Fuel injection valve for combustion engines

Info

Publication number: EP3990770A1
Application number: EP20734891.3A
Authority: EP
Inventors: Marco Ganser
Original assignee: Ganser Hydromag AG
Current assignee: Ganser Hydromag AG
Priority date: 2019-06-25
Filing date: 2020-06-23
Publication date: 2022-05-04
Also published as: WO2020260285A1

Abstract

The fuel injection valve (10) has a hydraulic control device (72) for controlling the axial movement of the injection valve member (56). The stem (76) of the intermediate valve member (78) of mushroom-shaped configuration of the intermediate valve (83) is guided in a sliding fit in the guide recess (74) of the intermediate part (66). The intermediate valve member (78) separates the control chamber (70) from the valve chamber (44) apart from the throttle passage (90) which is configured on the intermediate valve member. Furthermore, the throttle inlet (96) which is connected to the high pressure chamber (26) is configured on the intermediate valve member (78).

Description

Fuel injection valve for internal combustion engines

The present invention relates to a

Fuel injector for intermittent

Injection of fuel into the combustion chamber of an internal combustion engine according to the preamble of claims 1 and 20.

A fuel injector of this type is known, for example, from the document WO 2016/041739 A1. It has a hydraulic control device for controlling the axial movement of an injection valve member by changing the pressure in a control chamber. An intermediate valve of the hydraulic control device has a mushroom-shaped intermediate valve member, the shaft of which is guided in a sliding fit in a guide recess extending through an intermediate part. A head of the intermediate valve member with its sealing surface running at a radial distance around the shaft - in the closed position of the intermediate valve member, rests against an annular intermediate valve seat formed on the intermediate part, forming an annular sealing surface. An annular space bounded by the intermediate part, shaft and head and having an inner annular space running around the shaft is permanently connected to a high-pressure fuel inlet formed on a housing of the fuel injection valve via a high-pressure fuel inlet running through the intermediate part. The

Intermediate valve member separates a control chamber from a valve chamber, apart from a throttle passage formed on the intermediate valve member. In closed position of the intermediate valve element separates the intermediate valve of the high-pressure fuel inlet and the annular space from the control chamber and when the intermediate valve element is moved away from the closed position, the intermediate valve releases a connection between the annular space and the high-pressure fuel inlet and the control chamber. The valve chamber is also continuously connected to the valve via a throttle admission formed on the intermediate part

High pressure fuel inlet connected. By means of an electrically operated actuator arrangement, the valve chamber can be connected to and separated from a low-pressure fuel return. To trigger a

During the injection process, the valve chamber is connected to the low-pressure fuel return by means of the actuator arrangement, after which fuel flows from the control chamber into the valve chamber through the throttle passage in the intermediate valve element and, as a result of the associated pressure drop in the control chamber, the injection valve element is lifted from the injection valve seat on the housing. Since the opening movement of the injection valve member depends essentially solely on the throttle passage, this must be designed very precisely in order to be the same with a large number of fuel injection valves

To achieve injection behavior. The throttle admission can be manufactured with a slightly larger tolerance than the throttle passage, since the low pressure

Fuel return separated valve chamber only a small amount of fuel flowing through the throttle admission into the valve chamber leads to the opening of the intermediate valve member. The resulting rapid pressure increase in the control room moves that Injection valve member towards the injection valve seat, whereby the injection process is ended.

With those known from this document

For fuel injection valves, both the production of the intermediate part with the throttle admission and the intermediate valve element with the throttle passage and the testing of these two parts are complex and time-consuming.

The document WO 02/053904 A1 discloses a

Fuel injector with a piezoelectric actuator. This controls the connection between one

Valve chamber and a low-pressure fuel return. A control piston of an injection valve member is guided in a sliding fit in a cup-shaped guide part. The guide part and the control piston delimit a control chamber which is connected to the valve chamber on the one hand by a throttle passage formed in the bottom of the guide part and on the other hand is connected to the high-pressure chamber via a throttle inlet formed in the jacket of the guide part. A valve closing element controlled by means of the piezoelectric actuator is arranged in the valve chamber, which separates the valve chamber from the low-pressure fuel return when it is in contact with a first valve seat and, when it is in contact with a second valve seat formed on the guide part, shuts off the throttle passage, thereby separating the control chamber from the valve chamber and also the guide part lifts off from a valve body area and thereby connects the valve chamber with the high pressure chamber. This solution is complex, since to achieve an exact and, with many injection valves, always the same opening movement of the Injection valve member, which must be the case in a series of structurally identical injection valves, firstly requires precise coordination of the flow characteristics of both the throttle passage and the inlet throttle, and secondly, the guide part must also be moved specifically by the piezoelectric actuator.

In the fuel injector known from document DE 3700687 A1, a channel is connected to a return line during an injection by means of a solenoid valve. A non-return valve designed as a plate with a throttle bore is located between the channel and the control chamber. During the opening movement of the injection valve member, the control chamber can only empty into the channel via the throttle bore of the check valve plate, which means that the opening movement of the can be controlled

Injection valve member leads. This opens when the injection valve member closes

Check valve plate in such a way that the closing movement of the injection valve member can take place faster than the opening movement. In this embodiment, too, the fuel volume flow to close the injection valve member must flow solely through a throttle which connects the channel via an annular space to a pressure accumulator of the injection system assigned to the injection valve. This throttle has a small cross-section and is coordinated with another throttle located at the outlet of the channel. The opening and closing movement of the injection valve member is consequently controlled by three throttle bores, which must be precisely matched to one another. From the document WO 2005/019637 A1 and in particular from its figure 9, a fuel injector is known in which the opening movement of the

Injection valve member, similar to the fuel injector according to document DE 3700687 A1, can be determined by designing a throttle bore. To end the injection process, the piezo actuator of a pilot valve has to expand, which means that a high pressure channel connected to the high pressure inlet is released on a control body. The released, relatively large cross-section causes a large fuel inflow into the control chamber and thus a particularly rapid closing process of the injection valve member. To release the control body, a transmission pin is pressed onto the end face of the control body by a pilot valve pin of the actuator. The disadvantage of this solution is that the

Piezo actuator during the closing process of the

Injection valve member must expand. In this state, the piezo actuator is energized. Since the injection duration is only about 5% or less of the duration between two successive injections, the piezo actuator is almost constantly under electrical voltage. Furthermore, in this known solution, the position of the throttle bore, which determines the opening movement of the injection valve member, is unfavorable because it is located far away from the control chamber.

Similar to the injection valves known from the document WO 2016/041739 A1, the valve chamber in the injection valves known from the document EP 1 991 773 B1 is also via a throttle admission, which on Guide part is formed, connected to the high pressure chamber. A high-pressure fuel inlet, which is connected to the high-pressure chamber and opens into a throttle gap formed by the head of the mushroom-shaped injection valve member and the guide part, also leads through the guide part. In these injection valves, too, the control chamber is connected to the valve chamber via a throttle passage formed on the intermediate valve member. The document DE 10 2005 020 048 A1 discloses one

Injector with structure to control the nozzle needle. A valve back pressure chamber is provided to exert a back pressure of a first valve needle. Also is a

Hydraulic passage provided so that it extends through the valve back pressure chamber. A valve body is provided on a second valve needle and is driven in order to connect the hydraulic pressure passage to a fuel tank or to separate it therefrom and in order to thereby drive the first valve needle. The second valve needle is driven by hydraulic pressure generated by an actuator.

In one known from document EP 1 273 791 A2

Fuel injection valve, the control chamber is bounded on the one hand by the piston of the injection valve member, on the other hand by a slide valve body and on the circumferential side by a sleeve. Both the double-acting piston and the slide valve body are guided in a tight sliding fit on the sleeve. Through the

A throttle passage runs through the slide valve body, which is connected to a control passage in the Control body is permanently connected to the flow. A throttle inlet leads from the high pressure chamber into the control passage. This one is on the dem

Side facing away from the slide valve body can be connected to a low-pressure chamber by means of a pilot valve and can be separated from it again. The connection of the control passage with the low-pressure chamber leads to a pressure drop in the control chamber, as a result of which the injection valve member moves in the direction of the slide valve body and releases the injection nozzles. After separating the control passage from the low-pressure chamber, due to the pressure difference in the control chamber and on the side of the slide valve body facing away from it, the latter is moved away together with the injection valve in the direction of the control body, which leads to the injection nozzles closing rapidly. Under the power of one

The slide valve body then rests against the control body in a sealing manner again. The slide valve body has a further throttle passage opening into the control chamber.

A device for controlling an injector is known from WO 2019/016399 A1, in which the shaft of a mushroom-shaped intermediate valve member is guided in a guide part with a sliding fit. The passage-free intermediate valve element separates a control chamber from a valve chamber. On the guide part there is a throttle inlet and a throttle admission that is connected to the high pressure chamber and leads into the valve chamber

Formed throttle passage, which connects the control chamber with the valve chamber. The intermediate valve is also designed to provide a direct connection between the To create high-pressure chamber and the control chamber when the pressure level in the valve chamber is equal to or greater than a predetermined value.

It is an object of the present invention to develop a generic fuel injection valve in such a way that both the controllability of the opening movement of the injection valve member and a rapid closing process of the injection valve member are made possible with a particularly simple structure and minimal construction effort.

Next with the inventive

Fuel injector, the realization of multiple injections with a very short time interval can be achieved without problems. This object is achieved with a fuel injection valve according to claim 1 and claim 20.

The fuel injector according to the invention for the intermittent injection of fuel into the combustion chamber of an internal combustion engine has a housing which defines a longitudinal axis and which has a high-pressure fuel inlet on the one hand and an injection valve seat on the other.

In the housing there is a high pressure chamber which runs from the high pressure fuel inlet to the injection valve seat.

Furthermore, an injection valve member cooperating with the injection valve seat is arranged in the housing so as to be movable in the direction of the longitudinal axis. A compression spring is supported on the injection valve member and acts on it with a closing force directed in the direction against the injection valve seat.

On the other hand, the compression spring is preferably supported in a stationary manner relative to the housing.

There is also a guide part in which a double-acting control piston of the injection valve member is guided in a preferably close sliding fit.

A control chamber is delimited by the control piston, the guide part and an intermediate part and is thereby separated from the high-pressure chamber. The guide part and the intermediate part can be designed as independent components. However, it is also possible that these two parts are integrally formed in one piece on a single component. A hydraulic control device for controlling the axial movement of the injection valve member by changing the pressure in the control chamber has an intermediate valve, the mushroom-shaped intermediate valve member of which has a shaft guided in a guide recess of the intermediate part with a preferably close sliding fit and a head, which with its preferably in a radial distance around the shaft extending sealing surface - in the closed position of the intermediate valve member - on a preferably annular formed on the intermediate part

The intermediate valve seat rests in a sealing manner.

The intermediate part, the shaft and the head delimit an annular space in which one with the high-pressure space and thus with the high-pressure fuel inlet is preferably continuous connected fuel high pressure admission opens. The annular space preferably has an inner annular space which runs around the shaft and is delimited in the radial direction by the shaft and intermediate part, which is preferably excluded on the shaft itself, the

High-pressure fuel admission preferably opens into the inner ring space.

An electrically operated actuator arrangement is intended to connect a valve chamber to a low-pressure fuel return or to separate it from it. The valve chamber is preferably permanently connected to the high-pressure chamber and thus to the high-pressure inlet via a throttle inlet.

The intermediate valve member preferably permanently separates the control chamber from the valve chamber apart from a throttle passage formed on the intermediate valve member. This separates in the closed position of the intermediate valve member

Intermediate valve the fuel high pressure admission and the

Annular space from the control room. When the intermediate valve member is moved away from the closed position, the intermediate valve provides a connection between the annular space and the

High-pressure fuel admission with the control room free.

According to the invention, the throttle admission which preferably permanently connects the valve chamber to the high-pressure fuel inlet is formed on the intermediate valve member.

Since both the throttle passage and the throttle inlet are formed on the intermediate valve member, this can

Intermediate part, and possibly further workpieces, can be configured more simply than in the prior art The throttle admission as well as the throttle passage which is to be formed extremely precisely for the initiation of an injection process is formed on a single workpiece, namely the intermediate valve member. The throttle admission preferably opens into the valve chamber. In particular, the throttle admission preferably runs from an outer side of the shaft facing the annular space into the valve space.

The throttle passage preferably opens into the control chamber at a preferably flat end face of the head facing the control piston. In particular, the throttle passage preferably runs from the end face of the head facing the control piston into the valve chamber.

The throttle admission is preferably connected via the annular space to the high-pressure space and thus to the high-pressure fuel inlet. This enables a particularly simple training.

The annular space preferably has a split ring space adjoining the inner annular space. In the closed position of the intermediate valve member, this split ring space is formed by a circumferential gap between the intermediate part and the head of the intermediate valve member.

In the closed position of the intermediate valve member, the split ring space can have an at least approximately constant gap width. The gap width is preferably at least five times smaller than the inner ring space, measured in each case in the direction of the longitudinal axis.

With such a design of the annular space can Keep adhesion forces to a minimum.

Instead of a split ring space, other shapes can also be used, with an annular sealing surface or not; For example, embodiments with a conical sealing surface as disclosed in document WO 2010/088781 A1 or embodiments with a circumferential sealing surface as disclosed in document WO 2007/098621 A1.

Structure, functioning and different

Embodiments for the intermediate valve are also disclosed in the document WO 2016/041739 A1 and in the two documents mentioned above.

The inner annular space on the shaft of the intermediate valve member is preferably formed by a circumferential annular groove that is open in the radial direction to the outside and, viewed in the direction of the longitudinal axis, has such a dimension that the mouth of the high-pressure inlet is always at least almost completely in the area of the annular groove. Furthermore, the annular groove preferably adjoins the head directly. This also enables a simple design of the intermediate part.

The entire mouth of the is preferably located

High-pressure fuel allowance in the area of the inner ring space. This avoids any inclined bores that might otherwise be required on the intermediate part. The annular groove preferably has a trapezoidal one

Cross section, with the sloping side facing away from the head. When the intermediate valve member is open, this side is used by the High-pressure fuel admission to divert flowing fuel towards the head with little loss.

The throttle admission preferably extends from the annular groove, preferably from its radially inner base and preferably in the radial direction with respect to the longitudinal axis into the valve chamber. Alternatively, the shaft of the intermediate valve member can have a preferably groove-shaped pocket recess proceeding from the annular groove, from which the throttle admission extends into the valve chamber, preferably also with respect to the longitudinal axis in the radial direction. As a result of these embodiments, the throttle admission has a short length and its inlet opening is connected to the annular groove in an at least approximately unthrottled manner. Furthermore, the rotational position of the intermediate valve member does not play a role, since the throttle inlet is always connected to the high-pressure chamber via the circumferential annular groove. In the embodiment with a pocket recess, two diametrically opposite pocket recesses are preferably formed on the shaft in order to achieve symmetrical pressure conditions.

The throttle passage formed on the intermediate valve member preferably opens on the side facing away from the control chamber into a blind hole that is recessed on the intermediate valve member and belonging to the valve chamber, into which the throttle admission also opens. The throttle passage in the intermediate valve member is preferably formed adjacent to the control chamber. The throttle passage and the blind hole are preferably designed centrally to the longitudinal axis. As a result, on the one hand, the throttle passage with the desired length can be formed and on the other hand, the blind hole forms part of the valve chamber, so that the opening of the throttle inlet into the valve chamber is solved in a simple manner, namely preferably by a straight throttle bore running in the radial direction.

The housing preferably has a housing body with the high-pressure fuel inlet and a nozzle body on which the injection valve seat is formed. The intermediate part and thus the intermediate valve are preferably arranged in the nozzle body. As seen in the longitudinal direction, this enables a short design of the housing body and also of the injection valve member.

In an alternative preferred embodiment, the housing also has a housing body with the

High-pressure fuel inlet and a nozzle body on which the injection valve seat is formed, but the intermediate part and thus the intermediate valve are arranged between the housing body and the nozzle body. This allows a slim design of the

Nozzle body.

Preferably, the guide recess (open in the direction of the control chamber) is designed in the manner of a blind hole, an outlet bore being formed on the intermediate part of the guide recess, preferably from its bottom, to the low-pressure fuel return. This outlet bore is preferably designed to taper in a step-like manner, as seen from the guide recess. The from

Intermediate valve member and the guide recess limited space, the outlet hole and possibly the Blind bores in the intermediate valve member form the valve chamber.

Alternatively, two-part solutions can also be used, as disclosed for example in FIGS. 2 to 4, 8 and 9 of WO 2016/041739 A1 and in FIGS. 2, 4, 5, 7 and 8 of WO 2007/098621 A1 .

The mouth of the outlet bore facing the low-pressure fuel return preferably forms the

Fuel outlet. This embodiment also allows a simple and space-saving design of the

Fuel injector closed.

In a preferred embodiment, the housing has a housing body with the high-pressure fuel inlet and a nozzle body on which the injection valve seat is formed. An intermediate element is arranged between the housing body and the nozzle body, the intermediate part being arranged in the intermediate element or being received by it. For this purpose, the intermediate element has a receiving recess which is open in the direction of the nozzle body and connected to the high-pressure chamber and in which the intermediate part is arranged. The guide recess in the intermediate part is designed like a blind hole, with an outlet bore, preferably tapering in steps, being formed in the intermediate part from the guide recess to the low-pressure fuel return. The space delimited by the guide recess and the intermediate valve member, the possibly existing blind hole in the intermediate valve member and the outlet bore belong to the valve chamber or form it. In this embodiment it is possible that the intermediate element is part of the actuator arrangement.

A plunger of the actuator arrangement preferably runs through a corresponding passage in the intermediate element in order to close or open the low-pressure outlet formed on the intermediate part. The intermediate element preferably forms a guide element for the plunger.

The housing body preferably rests on one end face of the intermediate element and the nozzle body rests in a sealing manner on the opposite end face of the intermediate element.

In a preferred embodiment of the

Fuel injection valve, the housing has a housing body with the high-pressure fuel inlet and a nozzle body on which the injection valve seat is formed. An intermediate element is located between the housing body and the nozzle body, the intermediate part being arranged in a receiving recess of the intermediate element that is open in the direction of the nozzle body and connected to the high pressure chamber. The guide recess for the shaft of the

The intermediate valve member extends in the direction of the longitudinal axis through the intermediate part, an outlet bore being formed on the intermediate element from the guide recess to the low-pressure fuel return. This outlet bore is preferably designed to taper in a step-like manner, the mouth facing the low-pressure fuel return forming the low-pressure outlet. That of the guide recess, the intermediate valve member and the outlet hole as well as the possibly existing blind hole in the

Intermediate valve member limited volume belongs to the valve chamber or forms it. In this embodiment it is further preferably provided that the housing body on the one end face and the nozzle body on the opposite other end face of the intermediate part in a sealing manner.

Since the guide recess runs through the intermediate part, this is very easy to manufacture.

The intermediate valve seat is preferably formed on an at least approximately flat end face of the intermediate part. This also enables a simple design of the guide recess and the intermediate valve. Alternatively, however, it is also possible to use the

To limit the guide recess on the side facing the control chamber by a shoulder formed on the intermediate part and set back relative to the end face facing the nozzle body, this shoulder forming the intermediate valve seat. Between this

Shoulder and the face of the intermediate part facing the nozzle body, a head space is thereby formed in which the head of the intermediate valve member is located. This embodiment gives the possibility of simply designing the guide part, since its the

Intermediate part facing end can form a stop for a stroke limitation of the intermediate valve member. The guide part is preferably formed by a circular cylindrical guide sleeve on which the compression spring is supported, the compression spring thereby pressing the guide sleeve against the intermediate part in a sealing manner. This embodiment is particularly simple and the compression spring fulfills a twofold task.

When the fuel injector is in operation, the throttle passage can be temporarily closed in order to further minimize fuel loss. On the one hand, this can be the case as set out in the following paragraph. On the other hand, there is also the possibility of temporarily closing the throttle passage with a shut-off valve, as is known, for example, from WO 2018/162747 A1 and DE 195 16 565 A1. The control piston of the injection valve member preferably has a cam-shaped projection on its side facing the intermediate valve which closes the throttle passage when it rests against the intermediate valve member.

If there is no shut-off valve or if the control piston is in contact with the intermediate valve member, for example by means of a stroke limiter, to temporarily close the

With the throttle passage prevented, the control chamber is permanently connected to the valve chamber via the throttle passage.

Another fuel injector according to the invention for the intermittent injection of fuel into the combustion chamber of an internal combustion engine likewise has a housing defining a longitudinal axis, which has a high-pressure fuel inlet on the one hand and an injection valve seat on the other. In the housing there is a high pressure chamber which runs from the high pressure fuel inlet to the injection valve seat.

Also arranged in the housing is an injection valve member which is movably guided in the direction of the longitudinal axis and which interacts with the injection valve seat.

A compression spring, which is supported on the one hand against the injection valve member, acts on it with a closing force acting in the direction against the injection valve seat and, on the other hand, is preferably supported in a stationary manner relative to the housing, preferably on a guide part or a guide part designed as a guide sleeve. In the guide part or in the guide sleeve, a double-acting control piston of the injection valve member is guided in a tight sliding fit.

The fuel injector also has an intermediate part which, together with the guide part or the guide sleeve and the control piston, delimits a control chamber. The intermediate part and the guide part can be designed as independent components. However, it is also possible to form the intermediate part and the guide part in one piece on a single component. A hydraulic control device for controlling the axial movement of the injection valve member by changing the pressure in the control chamber is also arranged in the housing and has an intermediate valve whose mushroom-shaped intermediate valve member has a has a shaft and a head guided in a guide recess of the intermediate part in a preferably close sliding fit. With its sealing surface, which preferably runs at a radial distance around the shaft, the head rests in a sealing manner on an intermediate valve seat formed on the intermediate part in the closed position of the intermediate valve member.

An annular space is delimited by the intermediate part, shaft and head, in which a high-pressure fuel inlet, which is preferably permanently connected to the high-pressure fuel inlet for the sake of simplicity, opens.

Furthermore, an electrically operated actuator arrangement is arranged in the housing, which is intended to connect a valve chamber to and separate the valve chamber from a low-pressure fuel return. The

The valve chamber is connected to the

High-pressure chamber and thus preferably permanently connected to the high-pressure fuel inlet for the sake of simplicity. A plunger of the actuator arrangement preferably runs through a corresponding passage in the intermediate element in order to close or open the low-pressure outlet formed on the intermediate part. The intermediate element preferably forms a guide element for the plunger, i.e. the passage in the intermediate element preferably forms a guide for the plunger.

The intermediate valve member preferably permanently separates the control chamber from the valve chamber, except for one am Intermediate valve member formed throttle passage. In the closed position of the intermediate valve element, the intermediate valve separates the high-pressure fuel inlet and the annular space from the control chamber and when the intermediate valve element is moved away from the closed position, the intermediate valve releases a connection between the annular space and the high-pressure fuel inlet with the control chamber.

The throttle admission is preferably formed on the intermediate valve member. The housing further has a housing body with the high-pressure fuel inlet and a nozzle body on which the injection valve seat is formed. An intermediate element is arranged between the housing body and the nozzle body, the intermediate part being arranged in or received by the intermediate element. The intermediate part is preferably received in a blind hole-like receiving section formed on the intermediate element. The guide recess is preferably designed like a blind hole, an outlet bore being formed from the guide recess through the intermediate part to the low-pressure fuel return. This is preferably designed to taper in steps. The mouth of the outlet bore facing the actuator arrangement forms a low-pressure outlet which can be closed or released by the actuator arrangement.

The space delimited by the guide recess, the intermediate valve member and the intermediate part and an optionally present blind hole in the intermediate valve member belongs to the valve chamber or forms it. With the corresponding features, this fuel injector also has the advantages described above and can also, as described above, be embodied as specified in the relevant dependent claims.

The invention is described in more detail with reference to the embodiments shown in the figures. It shows purely schematically:

FIG. 1 shows in longitudinal section a first embodiment of an injection valve according to the invention;

FIG. 2, enlarged compared to FIG. 1, the part of the injection valve framed there by a rectangle labeled II;

FIG. 3 enlarged compared to FIG. 2, the one framed there with a rectangle labeled III

Part of the fuel injection valve with the control device;

FIG. 4 shows a second embodiment of an injection valve according to the invention in longitudinal section; FIG. 5, enlarged compared to FIG. 4, the part of the injection valve marked there with a rectangle labeled V;

FIG. 6, enlarged compared to FIG. 5, the part of the fuel injection valve with the control device framed by a rectangle labeled VI; FIG. 7 shows a third embodiment of an injection valve according to the invention in longitudinal section;

FIG. 8, enlarged compared to FIG. 7, the part of the injection valve framed there by a rectangle labeled VIII;

FIG. 9, enlarged compared to FIG. 8, the part of the fuel injection valve with the control device framed by a rectangle labeled IX; FIG. 10 shows the same representation as FIG. 9

Part of a fourth embodiment according to the invention of the fuel injection valve with the control device;

FIG. 11 shows the same representation as FIG. 9

Part of a fifth embodiment according to the invention of the fuel injection valve with the control device;

FIG. 12 shows a view of a mushroom-shaped intermediate valve member with an annular groove formed on the shaft and two pocket recesses emanating from the annular groove, the throttle inlets emanating from the pocket recesses;

FIG. 13 shows the intermediate valve member shown in FIG. 12 in a longitudinal section along the section line XIII-XIII in FIG. 12;

14 shows the intermediate valve member according to FIGS. 12 and

13 in a perspective view of the shaft; and FIG. 15 shows the intermediate valve member according to FIGS. 12 to 14 in a perspective view of the head.

In the description of the figures, the same reference symbols are always used for corresponding parts of all embodiments.

The fuel injection valve 10 shown in FIG. 1 is intended for the intermittent injection of fuel into the combustion chamber of an internal combustion engine. The fuel is under very high pressure of, for example, up to 200 bar or more.

The fuel injector 10 has a housing 12 defining a longitudinal axis L with a housing body 14, a nozzle body 16 on which an injector seat 18 is formed, and an actuator receiving body 20 which is arranged between the housing body 14 and the nozzle body 16. A union nut 22 supported on the nozzle body 16 takes the

Actuator receiving body 20 and is wound onto the housing body 14. The housing body 14 and the actuator receiving body 20, as well as this and the nozzle body 16 abut one another at the front, are pressed against one another in a sealing manner by means of the union nut 22 and aligned with one another in the direction of the longitudinal axis L. The outer shape of the housing 12 is at least approximately circular cylindrical in a known manner.

On the face of the housing body 14 facing away from the nozzle body 16 is a high-pressure fuel inlet 24 arranged, from which in the interior of the housing 12 - through the housing body 14, the actuator receiving body 20 and the nozzle body 16 - to the injection valve seat 18 a high pressure chamber 26 runs. The high-pressure fuel inlet 24 is formed by a valve carrier 28 which carries a basket-like perforated filter 32 for holding back any foreign particles in the fuel.

The valve carrier 28 can also carry a check valve whose disc-shaped valve member, which interacts with a valve seat formed on the valve carrier 28, has a bypass bore. The check valve allows fuel supplied via a high-pressure feed line to flow into the high-pressure chamber 26 practically without any obstacles, but prevents fuel from flowing out of the high-pressure chamber 26 into the high-pressure feed line with the exception of the bypass.

The structure and the mode of operation of the module designed as a cartridge with the valve carrier 28, the non-return valve that may be present and the perforated filter 32 are disclosed in detail in the document WO 2014/131497 A1. The high-pressure fuel inlet 24 and the valve carrier 28 with check valve and perforated filter 32 can also be designed, as disclosed in the document WO 2013/117311 A1. A possible embodiment of the high-pressure fuel inlet 24 and, if applicable, of the check valve, as well as a rod filter instead of the perforated filter 32 is known from document WO 2009/033304 A1. The disclosure of the above documents applies through

Reference being made to this as incorporated into the present disclosure.

Adjacent to the valve carrier 28, the high-pressure chamber 26 has a discrete storage chamber 34 formed on the housing body 14, which on the other hand communicates with the high-pressure chamber 26 via a flow channel 36

Injector seat 18 is connected. The discrete storage chamber 34, which is very long in terms of its cross-section, is arranged so as to run slightly obliquely with respect to the longitudinal axis L of the housing 12 and thus of the fuel injector 10.

The dimensions and the mode of operation of the discrete storage chamber 34 together with the possibly existing check valve with bypass is disclosed in detail in document WO 2007/009279 A1; this disclosure is incorporated into the present disclosure by reference.

In a blind hole-like recess of the actuator receiving body 20 facing the housing body 14, an electrically operated actuator assembly 38 is received in a known manner, which is intended with its plunger 40, which is spring-loaded in one direction and movable in the other direction by means of an electromagnet of the actuator assembly 38, with its sealing element 41 to close a low-pressure outlet 42 in order to separate a valve chamber 44 from a low-pressure fuel return 46 (see FIGS. 2 and 3), and the

To release low pressure outlet 42 to the valve chamber 44 and the low pressure fuel return 46 to each other connect. The longitudinal axis, denoted by 48, of the plunger 40 and thus of the actuator arrangement 38 runs parallel and eccentrically to the longitudinal axis L.

The plunger 40 extends through the base of the cup-shaped actuator receiving body 20, which forms a guide element 21 for the plunger 40. The plunger 40 has guide wings protruding in the radial direction, with which it is slidably guided on the guide element 21 parallel to the longitudinal direction L. The guide vanes form passages running in the longitudinal direction L through which the fuel can flow from the low-pressure outlet 42 to the low-pressure fuel return 46.

Approximately parallel to the longitudinal axis L of the housing 12, a channel 52 runs from an electrical connection 50 through the housing body 14 to the actuator arrangement 38, in which the electrical control line (not shown here) for controlling the actuator arrangement 38 is received. As can be seen from FIG. 2, enlarged with respect to FIG. 1, the conical injection valve seat 18 is formed on the nozzle body 16 and is directly connected to the storage chamber 34 and thus the high-pressure fuel inlet 24 via the flow channel 36. In the flow direction of the fuel downstream of the injection valve seat 18, injection openings 54 are formed in a hemispherical free end region of the nozzle body 16 in a known manner, through which, when lifted from the injection valve seat 18 Injection valve member 56, the fuel under very high pressure into the combustion chamber of the

Internal combustion engine is injected.

The injection valve member 56 is needle-shaped and interacts with the injection valve seat 18. The injection valve member 56 is guided movably in the direction of the longitudinal axis L in a circular cylindrical guide bore 57 in the nozzle body 16, which is concentric to the longitudinal axis L and belongs to the high pressure chamber 26, with recesses on the injection valve member 56 running in the longitudinal direction, open to the outside in the radial direction and separated from one another by guide vanes the low-loss flow of fuel to the injection valve seat 18 and to the injection openings 54 is made possible. As can be seen particularly from FIG. 2, upstream of this guide bore 57 is the interior space 58 of the nozzle body 16, which is part of the high pressure chamber 26 and is circular in cross section

Actuator receiving body 20 widening twice, then tapering to a receiving section 58 'and then widening again. Between the two extensions and between these and the taper to the receiving section 58 ', the nozzle body 16 has a hollow cylindrical first and second section 60, 60' on the inside.

In the area of this first section 60, a support ring is formed on the injection valve member 56, on which a compression spring 62 is supported with its one end. With its other end, the compression spring 62, in the area of the second section 60 ', is on one The guide sleeve 64 'forming the guide part 64 is supported on the end face, the other end region facing away from the guide sleeve extending into the receiving section 58' and thus held in a centered manner. The compression spring 62 acts on the injection valve member 56 with a closing force acting in the direction of the injection valve seat 18.

On the other hand, the compression spring 62 holds the guide part 64 or the guide sleeve 64 'with its end face facing away from the compression spring 62 in sealing contact with a cylindrical intermediate part 66 which is received in the receiving section 58' and thus held centered. The guide part 64 can be designed in another shape, as a sleeve, for example as a cuboid or ring body. From the flat end face of the nozzle body 16 facing the actuator receiving body 20 to the second section 60 ', a section of the flow channel 36 formed by an inclined bore in the nozzle body 16, through which fuel enters the interior 58 and in this on the guide part 64 or the guide sleeve 64', runs The compression spring 62 and the support ring can be fed to the injection openings 54 with as little loss as possible.

In the guide part 64 or in the guide sleeve 64 ′, a double-acting control piston 68 molded onto the injection valve member 56 is guided in a tight escapement fit from approximately 3 μm to 5 μm in the direction of the longitudinal axis L. The control piston 68, the guide part 64 or the guide sleeve 64 'and the intermediate part 66 delimit a control chamber 70 from the high-pressure chamber 26.

The intermediate part 66 is part of a hydraulic control device 72, which is also described with reference to FIG.

As is particularly shown in FIG. 3, a circular cylindrical guide recess 74, here embodied like a blind hole, runs in the intermediate part 66 from the flat end face facing the control chamber 70. A shaft 76 of a mushroom-shaped intermediate valve member 78 is in this with a close sliding fit of approximately 3 μm to 10 μm guided. A head 80 of the intermediate valve member 78 which is formed integrally with the shaft 76 is located in the control chamber 70 and, with its side facing the intermediate part 66, interacts with this intermediate part 66, the flat end face of which has an annular shape

Intermediate valve seat 82 forms.

The intermediate valve member 78, together with the intermediate valve seat 82 formed on the intermediate part 66, forms an intermediate valve 83.

On the guide part 64 or on the guide sleeve 64 ', a stop shoulder 84 is formed at a distance from the intermediate part 66, which limit the opening stroke Hl of the intermediate valve member 78. In order to achieve the lowest possible loss of fuel flow from one

To enable high-pressure fuel admission 86 into the control chamber 70, there is a sufficiently large gap radially on the outside between the head 80 and the guide sleeve 64 'or the guide part 64, and the head has it 80, on its side facing the stop shoulder 84, one or more circumferentially distributed, wedge-like flow grooves 88, two of which are shown in FIG. 3 and which allow the fuel to flow from the gap to the control piston 68 with little loss, even if that

The intermediate valve member 78 is in the open position and the head 80 rests against the stop shoulder 84.

Adjacent to the control chamber 70, a throttle passage 90 is formed on the intermediate valve member 78, which, on the other hand, is formed in one on the intermediate valve member 78 concentric to the

Longitudinal axis L recessed blind hole 92 opens. The throttle passage 90 also opens into the control chamber 70 at the flat face 801 of the head 80 facing the control piston 68, so that the throttle passage 90 runs from the face 801 of the head 80 facing the control piston 68 into the valve chamber 44. The arrangement of the

Throttle passage 90 on the end face 801 of the head 80 facilitates precise manufacture of the throttle passage 90. The high-pressure fuel inlet 86 is in the

The embodiment according to FIGS. 1 to 3 is formed by a bore leading in the radial direction through the intermediate part 66 from the inclined bore belonging to the flow channel 36 to the guide passage 74. The fuel high pressure admission 86 is permanent with the

High-pressure fuel inlet 24 and has a flow cross-section that is preferably much larger than the throttle passage 90.

A throttle admission 96 is provided on the intermediate valve member 78 through a bore running in the radial direction in the shaft 76 formed, which is permanently flow-connected to the high-pressure chamber 26 and thus to the high-pressure fuel inlet 24 and opens into the blind hole 92.

From the bottom of the guide recess 74 through the intermediate part 66, initially at an angle to the longitudinal axis L and then parallel to this, a step-like tapering outlet bore 102 to the low-pressure fuel return 46. The one facing the low-pressure fuel return 46

The mouth of the outlet bore 102 forms the low-pressure outlet 42.

For the sake of completeness, it should be mentioned that the

The flow cross-section of this outlet bore 102 is at least the same size everywhere, but is preferably greater than the sum of the flow cross-sections of the throttle passage 90 and the throttle inlet 96.

For correct positioning of the intermediate part 66 relative to the actuator receiving body 20 and thus to the actuator assembly 38, the intermediate part 66 and the actuator receiving body 20 have aligned, facing, blind hole-like positioning bores 106 in which a common positioning pin 104 is inserted.

The intermediate part 66 together with the shaft 76 and head 80 of the intermediate valve member 78 delimit an approximately hollow cylindrical inner annular space 108 running around the shaft 76 into which the high pressure inlet 86 opens directly and permanently. In this embodiment and in the other embodiments, the intermediate valve 83 has the task, in the closed position of the intermediate valve member 78, to separate the high-pressure fuel inlet 86 and the inner annular space 108 from the control chamber 70 and, with the intermediate valve seat 82 lifted from the intermediate valve seat 82, the connection between the To release inner ring space 108 and high pressure admission 86 with the control chamber 70.

As can be seen in particular from FIG. 3, the shaft 76 of the intermediate valve member 78 has a circumferential annular groove 110 which is open towards the outside in the radial direction and which directly adjoins the head 80 to form the inner annular space 108. Seen in the direction of the longitudinal axis L, the annular groove 110 has such a dimension that the mouth of the high pressure inlet 86 is always completely in the area of the annular groove 110, even when the intermediate valve member 78 is in the open position and is in contact with the stop shoulder 84 with the intermediate valve member 78 open, to allow the fuel flowing in through the high-pressure fuel inlet 86 to flow on to the control chamber 70 with little loss.

In the exemplary embodiment shown, the annular groove 110 has a trapezoidal cross section, the inclined side facing away from the head 80 and serving to deflect the fuel with little loss.

According to FIG. 3, the throttle admission 96 runs from the bottom of this annular groove 110 in the radial direction to the blind hole 92 and thus opens into the valve chamber 44. In certain embodiments, it is possible that, in addition to the annular groove 110, a circumferential annular groove 110 ′ open to the inside in the radial direction is formed on the intermediate part 66. The inner annular space 108 'can then be formed by the annular groove 110 on the shaft 76 of the intermediate valve member 78 and the annular groove 110' on the intermediate part 66. It is also conceivable that in certain embodiments no annular groove is formed on the shaft 76 of the intermediate valve member 78 and the annular space 108 'is only formed by the annular groove 110' on the intermediate part 66.

On the side facing the shaft 76 and thus the intermediate part 66, an annular sealing bead 112 protruding from the remaining area of this side of the head 80 is formed on the head 80, the free end face 114 of which the sealing surface 116 of the

Intermediate valve member 78 forms. Opposite this sealing surface 116, the head 80 on which the

Intermediate part 66 facing side, radially inside and radially outside an undercut 118, the surfaces of these undercuts 118, shown in FIG

Embodiment, located in a plane which runs at right angles to the longitudinal axis L. Of course, the sealing surface 116 also lies in a plane which runs at right angles to the longitudinal axis L, and the flat end face of the intermediate part 66 forming the intermediate valve seat 82 also lies in a plane which runs at right angles to the longitudinal axis L.

Since the sealing bead 112 is offset in the radial direction towards the outside by approx. 0.2 mm to 1.0 mm with respect to the guide recess 74, the remains in the closed position Intermediate valve member 78, between the head 80 and the intermediate part 66 a split ring space 118, which is delimited radially on the outside by the sealing bead 112 and opens radially inward directly into the inner annular space 108 and together this forms an annular space 120 which is delimited by the intermediate valve member 78 and the intermediate part 66 .

It can be seen from FIG. 3 that the sealing bead 112 can also be provided further out in the radial direction. This enables an optimal adaptation of the intermediate valve 83 to the desired ones

Injection properties. If the active area of the intermediate valve member 78, designed as a double-acting piston, is enlarged, the intermediate valve 83 opens faster to end an injection process than if this active area is selected to be smaller.

Furthermore, the adhesion between the intermediate part 66 and the intermediate valve member 78 is minimized in that the annular sealing surface 112, which is formed by the sealing surface 116 and the intermediate valve seat 82, is minimized. The throttle admission 96 also supports a rapid opening movement of the intermediate valve member 78.

If the intermediate valve 83 is closed and the plunger 40 is lifted from the low-pressure outlet 42 for an injection, the opening movement of the injection valve member 56 is determined practically exclusively by the throttle passage 90. This is therefore very precisely machined with small tolerances. For the sake of completeness, it should be mentioned that the valve chamber 44 delimited from the control chamber 70 by the intermediate valve member 78 is formed by the blind hole 92, the outlet hole 102 and the volume between the shaft 76 and the bottom of the guide recess 76.

The head 88 of the intermediate valve member 78 and the end face of the intermediate part 66 cooperating with it are preferably designed according to one of the embodiments disclosed in the document WO 2016/041739 A1. Alternative possible shapes of the sealing surfaces are disclosed in the documents WO 2010/088781 A1, WO 2007/098621 A1 and WO 2016/041739 A1.

The injection valve member 56 has on its

The side facing the intermediate valve 83 has a cam-like projection 56 ', which serves as a stroke limiter for the stroke H2 of the injection valve member 56 and thereby closes the throttle passage 96 by resting against the intermediate valve member 78.

Starting from the closed position of the intermediate valve 83 shown in Figures 1 to 3, for a

Injection by means of the electromagnet

Actuator assembly 38 of the plunger 40 and thus the

Sealing element 41 is lifted off the intermediate part 66, whereby the low-pressure outlet 42 is released. This has the consequence that a larger amount of fuel per unit of time from the valve chamber 44 into the low-pressure

Fuel return 46 flows out than can flow through the throttle passage 90 and the throttle inlet 96 into the valve chamber 44. This reduces the pressure in the valve chamber 44, with the result that on the one hand the intermediate valve member 78 is pressed with great force against the intermediate part 66 in order to keep the intermediate valve 83 securely closed, and on the other hand the pressure in the control chamber 70 drops. This in turn has the consequence that the effect of the double-acting control piston 68 against the force of the compression spring 62 lifts the injection valve member 56 from the injection valve seat 18, thereby starting an injection of fuel into the combustion chamber of the internal combustion engine.

If this injection is to be ended, the plunger 40 and consequently its sealing element 41 are brought into contact with the intermediate part 66, whereby the low-pressure outlet 42 is closed. The pressure in the valve chamber 44 increases due to the fuel flowing in through the throttle passage 90 and the throttle inlet 96, which causes the intermediate valve member 78 to move away from the intermediate valve seat 82. This movement is further supported by the double piston effect of the intermediate valve member 78 designed according to the present invention, the adhesion counteracting this opening movement of the intermediate valve member 78 being minimized.

By lifting the head 80 of the intermediate valve member 78 from the intermediate part 66, a large flow cross section is quickly released from the annular space 120 into the control space 70, which leads to a rapid termination of the

The injection process results in that the injection valve member 56 is quickly moved towards the injection valve seat 18 and comes to rest against it. This mode of operation also applies to the further embodiments shown in the figures and to be described below.

In all the embodiments shown, the intermediate part 66 is designed as a one-piece body. It is also possible to realize the intermediate part 66 from two workpieces that lie against one another in a sealing manner. A possible dividing line 66 ′ of the intermediate part 66 into the two workpieces is shown in FIG. 3. This separation takes place preferably at the bottom of the blind hole-like

Guide recess 74.

It is also possible to make the intermediate part 66 longer up to the dividing line 66 ″ in FIG. 3 and the guide part 64 correspondingly shorter. In this case, the intermediate part 66 for receiving the head 80 of the intermediate valve member 78 has a head space 128 with shoulder 126, like this 7 to 11 and is described in connection with these figures.

The embodiments shown in the other figures will only be described insofar as they differ from the embodiment according to FIGS. 1 to 3.

The embodiment of the fuel injector 10 shown in FIGS. 4 to 6 again has a housing 12 with a housing body 14 on the one hand and a nozzle body 16 on which the injector seat 18 is formed on the other hand. However, an intermediate element 122 rests on the front side of the housing body 14, the outer contour of which essentially corresponds to that of the housing body 14. Between the intermediate element 122 and the Nozzle body 16 is an intermediate body 124. The intermediate element 122 and the intermediate body 124 are received in the union nut 22, which is supported on the nozzle body 16 and at the other end is wound onto the housing body 14, so that the intermediate element 122 on the one hand on the housing body 14 and on the other hand on the intermediate body 124 and this in turn bear against the nozzle body 14 at the end in a sealing manner. As a result, these workpieces are also kept aligned with one another in the direction of the longitudinal axis L. In the case of the solution shown in FIGS. 4 to 6, it is also possible to form the nozzle body 16 integrally with the intermediate body 124 in one piece.

It is also possible to make the intermediate element 122 and the intermediate part 66 longer up to the dividing line 66 'in FIG. 6 and the intermediate body 124 correspondingly shorter. The intermediate part 66 for receiving the head 80 of the intermediate valve member 78 has a head space 128 with a shoulder 126, as shown in FIGS. 7 to 11 and described in connection with these figures.

On the face of the housing body 14 facing away from the nozzle body 16, the high-pressure fuel inlet 24 is arranged, from which inside the housing 12 - through the housing body 14, the intermediate element 122, the intermediate body 124 and the nozzle body 16 - to

Injection valve seat 18 of high pressure chamber 26 runs. In the embodiment shown is the

High-pressure fuel inlet 24 molded directly onto the housing body 14. However, there is also the possibility of a corresponding embodiment shown in FIG Provide valve support 128 with a perforated filter 32.

As can be seen from FIG. 4, the high pressure chamber 26 does not have a discrete storage chamber 34, although such a chamber can be provided in accordance with FIG. 1. The belonging to the high pressure chamber 26

Flow channel 36 runs in the housing 12 from

High-pressure fuel inlet 24 up into the receiving section 58 'of the intermediate element 122. In particular, the flow channel 36 runs through the intermediate element 122. An actuator receiving body 20 is not provided in the present embodiment. For this purpose, a blind hole-like recess facing the intermediate element 122 is formed on the housing body 14, in which the electrically operated actuator arrangement 38 is received. The plunger 40 of the actuator arrangement 38 is in turn spring-loaded in one direction and movable in the other direction by means of the electromagnet of the actuator arrangement 38 and is intended, together with the sealing element 41, to close the low-pressure outlet 42 in order to separate the valve chamber 44 from the low-pressure fuel return 46, and to release the low-pressure outlet 42 on the intermediate part 66 in order to connect the valve chamber 44 and the low-pressure fuel return 46 to one another. In the present embodiment, too, the longitudinal axis, denoted by 48, of the plunger 40 and thus of the actuator arrangement 38 is parallel and eccentric to the longitudinal axis L of the housing 12.

The intermediate element 122 forms the guide element 21 for the plunger 40, which is designed the same as above in connection with the embodiment according to FIG Figures 1 to 3 described.

From the electrical connection 50 through the housing body 14 to the actuator arrangement 38, the channel, not shown for the sake of clarity, in which the electrical control line for controlling the

Actuator assembly 38 runs.

As shown in particular in FIGS. 4 and 5, the conical injection valve seat 18 and the injection openings 54 are formed on the nozzle body 16. The needle-shaped injection valve member 56 is guided in the circular cylindrical guide bore 57 in the nozzle body 16 belonging to the high-pressure chamber 26 so as to be movable in the direction of the longitudinal axis L with its guide vanes, as described in connection with FIGS. 1 and 2. As can be seen in particular from FIG. 5, upstream of the guide bore 57, the inner space 58 belonging to the high pressure chamber 26 and having a circular cross section is formed over a short length on the nozzle body 16 and over the entire length of the intermediate body 124 on the latter. In the direction of the intermediate element 122, the interior space 58 has a first expansion in the nozzle body 16 and a second conical expansion on the intermediate body 124, with between this expansion and the

Intermediate element 122 of intermediate body 124 is designed in the shape of a hollow cylinder on the inside and forms section 60.

In the area of this section 60, the compression spring 62 is supported in a known manner on the injection valve member 56, which with its other end on the Guide part 64 forming guide sleeve 64 ^s is supported on the end face. In a known manner, the compression spring 62 acts on the injection valve member 56 with a closing force acting in the direction of the injection valve seat 18. On the other hand, the compression spring 62 holds the guide part 64 or the guide sleeve 64 'with its end face facing away from the compression spring 62 in sealing contact with the intermediate part 66, which is received and centered in the receiving section 58' formed on the intermediate element 122. The

Receiving section 58 ′ is formed by a blind hole-like recess open in the direction of the intermediate body 124 and thus the nozzle body 16. The intermediate part 66 is held in sealing contact with the bottom of the receiving section 58 'via the compression spring 62. The guide recess 74 is designed in the manner of a blind hole, an outlet bore 102 tapering in a step-like manner being formed in the intermediate part 66 from the guide recess 74 to the low-pressure outlet 42. The flow channel 36 opens radially outside the intermediate part 66 into the receiving section 58 ', whereby the fuel supplied through the flow channel 36 between the intermediate element 122 and the intermediate part 66 and between the guide sleeve 64' and the intermediate body 124 into the interior 58 and to the injection valve seat 18 can flow with little loss.

The intermediate part 66 can be positioned in the intermediate element 122 by means of positioning pins 104, as shown in FIG. 3. In the guide part 64 or in the guide sleeve 64, in exactly the same way as described above, the control piston 68 of the injection valve member 56 is guided displaceably in the direction of the longitudinal axis L. The control piston 68, the guide part 64 or the guide sleeve 64 ″ and the intermediate part 66 delimit the control chamber 70.

The intermediate part 66 is part of the hydraulic control device 72 and, together with the intermediate valve member 78, is embodied in the same way as described above, in particular in connection with FIG. 3.

A throttle inlet 96 is formed on the intermediate valve member 78 through a bore running in the radial direction in the shaft 76, which is flow-connected to the high-pressure chamber 26 and thus to the high-pressure fuel inlet 24 and opens into the blind hole 92. In certain embodiments, however, it is also possible to dispense with the throttle inlet 96 on the intermediate valve member 78 and instead to form a throttle inlet 96 ′ on the intermediate part 66, which runs from the high-pressure chamber 26 into the valve chamber 44. In the embodiment of the injection valve 10 according to the invention shown in FIGS. 7 to 9, the housing 12 is essentially designed in the same way as shown and described in connection with FIGS. 4 to 6. The actuator assembly 38 is designed in the same way as described above, but the recess has in

Housing body 14 for the actuator assembly 38, in

Longitudinal direction L, a greater extent, so that a cylindrical guide element 21 for the plunger 40 also finds space in this recess. The guide element 21 and the housing body 14 abut the end face on the intermediate part 66, on which the intermediate body 124 abuts on the other hand. The union nut 22 engages the nozzle body 16, centers the intermediate body 124 arranged in it and the intermediate part 66 and, as is known, is attached to the housing body 14 so that these parts of the housing are pressed against one another in a sealing manner.

The flow channel 36 runs through the guide part 64 and opens into the interior 58 between the intermediate body 124 and the guide part 64 or the guide sleeve 64 ″. The circular cylindrical intermediate part 66, which corresponds with its outer contour to the outer contour of the housing body 14, is part of the hydraulic control device 72, which is shown enlarged in Figures 8 and 9.

The guide recess 74 is again designed like a blind hole and is open in the direction of the control chamber 70. It is delimited by a shoulder 126 formed on the intermediate part 66 and forming the intermediate valve seat 82. From this shoulder 126 to the intermediate body 124 and thus the end face facing the nozzle body 16, a head space 128 is cut out on the intermediate part 66, in which the head 80 of the mushroom-shaped intermediate valve member 78 is located. This is designed in the same way as in connection with the embodiments disclosed above.

The stop shoulder 84 (Fig. 3) corresponding stroke limitation for the intermediate valve member 78 is in the present embodiment by the Intermediate part 66 facing end face of the guide part 64 or the guide sleeve 64 ″ is formed.

The fuel inlet 86 in the intermediate part 66 is formed by a blind hole 130 that runs parallel to the longitudinal axis L and extends from the end face facing the intermediate body 124 and thus the nozzle body 16, is connected to the high pressure chamber 26 and a radial hole 132 that crosses this blind hole 130 and which, as in the embodiments according to FIGS. 1 to 6, opens into the inner annular space 108. The radial bore 132 is closed radially on the outside by means of a sealing screw 134.

The embodiment shown in FIG. 10 corresponds to that according to FIGS. 7 to 9, only the fuel inlet 86 being designed differently. The blind hole 130 now no longer runs parallel to the longitudinal axis L, but rather its longitudinal direction includes an acute angle with the longitudinal axis L. Another blind hole 136, into which the blind hole 130 opens, runs from the guide recess 74. For the sake of completeness, it should be mentioned that the further blind hole 136 in turn opens into the inner annular space 108.

In the embodiments according to FIGS. 7 to 10, it is also possible to form the fuel inlet 86 in an arc shape with a curvature instead of by means of straight bores; this for example by producing the intermediate part 66 by means of a 3D printing process. In this way, flow losses can be kept small and, in the embodiment according to FIGS. 7 to 10, the Sealing screw is omitted.

Furthermore, in the embodiment according to FIG. 10, it is possible to provide the separation between the intermediate part 66 and the intermediate body 124 at the separation line 66 ', which leads to a configuration similar to that shown in FIGS. 1 to 6.

In the embodiments shown in FIGS. 7 to 11, it is also possible to use the nozzle body 16 with the

To form intermediate body 124 in one piece integrally. The embodiment according to FIG. 11 has, in the same way as that according to FIGS. 4 to 6, an intermediate element 122 which is arranged between the housing body 14 and guide element 21 on the one hand and the intermediate body 124 on the other. The intermediate part 66 is sleeve-shaped, the

Guide recess 74 from shoulder 126 (compare FIGS. 7 to 10) through intermediate part 66, that is to say as a straight bore, up to its end face facing actuator arrangement 38. The head space 128, in which the head 18 of the intermediate valve member 78 is located, is again located between the shoulder 126 and the end face of the intermediate part 66 facing the nozzle body 16. The shoulder 126 forms the intermediate valve seat 82, which interacts with the sealing bead 112 and thus the sealing surface 116 of the intermediate valve member 78.

The guide part 64 designed as a guide sleeve 64 is held in contact with the intermediate part 66 in a sealing manner by means of the compression spring 62, the guide sleeve 64 'in turn forms the stroke limitation for the intermediate valve member 78.

The intermediate valve 83 and thus the intermediate part 66 and the intermediate valve member 78 are in one of the

_A receiving section 58 'forming the receiving recess 122' of the intermediate element 122 was added. The

The receiving recess 122 'has an extension running around the intermediate part 66 into which the

Flow channel 36 opens out, the intermediate part 66 having guide vanes radially on the outside in order to be held centered in the intermediate element 122 and to permit a low-loss flow of fuel in the direction of the injection valve seat 18.

Two inclined bores, which form the fuel inlet 86, run from this widening through the intermediate part 66. Of course, only one inclined bore could be present.

In this embodiment, the valve chamber 44 is through the blind hole 92 in the shaft 76 of the intermediate valve member 78, the likewise stepped outlet bore 102 in the intermediate element 122 and the volume between the

Intermediate valve member 78 and the intermediate element 122 formed.

The mouth of the outlet bore 102 forms the low-pressure outlet 42, which is formed on the intermediate element 122 in the present example. He is by means of the

Sealing element 41 of the plunger 40 of the actuator assembly 38 closable in order to separate the valve chamber 44 from the low-pressure fuel return 46, or releasable in order to connect the valve chamber 44 with the low-pressure fuel return. To connect fuel return 46.

Otherwise, the intermediate valve 83 is designed the same as in all other embodiments.

12 to 15 show an alternative embodiment of the intermediate valve member 78. As in all of the embodiments described above and shown in FIGS. 1 to 11, the intermediate valve member 78 is mushroom-shaped, with the shaft 76 on which the inner annular space 108 is formed through the annular groove 110 is formed, and the head 80, on which the flow grooves 88 are formed. The throttle passage 96 no longer extends from the bottom of the annular groove 110, but rather two diametrically opposed pocket recesses 138 on the shaft 76, starting from the annular groove 110. These run as grooves open in the radial direction towards the outside in the axial direction towards the free end of the shaft 76, but they end before that in order to separate the valve chamber 44 from the annular groove 110 and thus the high-pressure fuel inlet 24, except for the throttle inlet 96, to ensure which here runs in the radial direction from one of the two pocket recesses 138 through the shaft 76 into the blind hole 92 and thus into the valve chamber 44.

Claims

1. Fuel injector for intermittent

Injection of fuel into the combustion chamber of an internal combustion engine, with a housing (12) defining a longitudinal axis (L), a high-pressure fuel inlet and a

Has an injection valve seat (18), a high-pressure chamber (26) arranged in the housing (12) and running from the high-pressure fuel inlet (24) to the injection valve seat (18), an injection valve member (56) arranged in the housing (12) to be adjustable in the direction of the longitudinal axis (L) , which cooperates with the injection valve seat (18), a compression spring (62), which the injection valve member (56) with a in the direction against the

Closing force directed towards the injection valve seat (18), a guide part (64) in which a control piston (68) of the injection valve member (56) is guided in a sliding fit, an intermediate part (66) which, together with the guide part (64) and the control piston (68 ) a control chamber (70) delimits a hydraulic control device (72) for controlling the axial movement of the

Injection valve member (56) by changing the pressure in the control chamber (70), with an intermediate valve (83), its mushroom-shaped

Intermediate valve member (78) one in one

Guide recess (74) of the intermediate part (66) has a sliding fit guided shaft (76) and a head (80) which, with its sealing surface (116) extending around the shaft (76) - in the closed position of the intermediate valve member (78) - is attached to an on

Intermediate part (66) formed intermediate valve seat (82) rests against an annular space (120) bounded by the intermediate part (66), shaft (76) and head (80), in which an annular space (120) connected to the high-pressure fuel inlet (24)

Fuel high pressure admission (86) opens, and an electrically operated actuator arrangement (38) for connecting a via a throttle admission (96) to the

High fuel pressure inlet (24) connected

Valve chamber (44) with and separation of the valve chamber (44) from a low-pressure fuel return (46), the intermediate valve member (78) separating the control chamber (70) from the valve chamber (44) - except for one on the

Intermediate valve member formed throttle passage (90) - separates, in the closed position of the

Intermediate valve member (78), the intermediate valve (83) separates the high-pressure fuel inlet (86) and the annular space (120) from the control chamber (70) and from the

In the closed position, the intermediate valve member (78) moved away, the intermediate valve (83) opens a connection between the annular space (120) and the high-pressure fuel inlet (86) with the control space (70), characterized in that the throttle admission (96) is formed on the intermediate valve member (78).

2. The fuel injector according to claim 1, characterized in that the throttle inlet (96) is connected to the high-pressure fuel inlet (24) via the annular space (120).

3. Fuel injector according to claim 1 or 2, characterized in that the annular space (120) has an inner annular space (108) directly adjoining the shaft (76) and a split ring space (118) adjoining this, which - in the closed position of the intermediate valve member (78 ) - is formed by a gap between the intermediate part (66) and the head (80), and preferably the split ring space (118) - in the closed position of the

Intermediate valve member (78) - has an at least approximately constant gap width, the gap width being at least five times smaller than the inner annular space (108), each measured in the direction of the longitudinal axis (L).

4. Fuel injector according to one of claims 1 to 3, characterized in that the shaft (76) of the intermediate valve member (78) has a circumferential, radially outwardly open annular groove (110) which, viewed in the direction of the housing axis (L) , has such a dimension that the mouth of the high-pressure fuel inlet (86) is always at least approximately completely in the area of the annular groove (110), and preferably the annular groove (110) directly adjoins the head (80), wherein the annular groove (110) forms at least part of the annular space (120), optionally the inner annular space (108).

5. The fuel injector according to claim 4, characterized in that the throttle admission (96) from the bottom of the annular groove (110), preferably in a radial direction

Direction, runs.

6. The fuel injector according to claim 4, characterized in that the shaft (76) of the intermediate valve member (78) has a pocket recess (138), preferably two diametrically opposite one another, extending from the annular groove (110), preferably in the radial direction towards the outside

Pocket recesses (138), from which a pocket recess (138) extends from the throttle inlet (96) to the valve chamber (44).

7. Fuel injection valve according to one of claims 1 to 6, characterized in that the throttle passage (90) formed on the intermediate valve member (78), preferably adjacent to the control chamber (70), on the other hand into a blind hole belonging to the valve chamber and recessed on the intermediate valve member (78) (92) opens into which the throttle admission (96) opens.

8. Fuel injector according to one of claims 1 to 7, characterized in that the housing (12) has a housing body (14) with the

High-pressure fuel inlet (24) and a nozzle body (16) on which the injection valve seat (10) is formed and the intermediate valve (83) is arranged in the nozzle body (16). 9. Fuel injector according to one of claims 1 to 7, characterized in that the housing (12) has a housing body (14) with the

High-pressure fuel inlet (24) and a nozzle body (16) on which the injection valve seat

(10) is formed and the intermediate part (66) is arranged between the housing body (14) and the nozzle body (16).

10. Fuel injector according to one of claims 1 to 9, characterized in that the

Guide recess (74) is formed like a blind hole and from the guide recess (74), preferably from its bottom, to the low-pressure fuel return (46), an outlet bore (102), preferably tapering in steps, is formed on the intermediate part (66), the one from the guide recess (74) and the intermediate valve member (78) and the outlet bore (102) belong to the valve chamber (44).

11. Fuel injector according to one of claims 1 to 7, characterized in that the housing (12) has a housing body (14) with the

High-pressure fuel inlet (24) and one

Has nozzle body (16) on which the injection valve seat (10) is formed and an intermediate element (122) between the housing body (14) and the

The nozzle body (16) is arranged, the intermediate part (66) being arranged in the intermediate element (122) in a receiving recess (122 ') open in the direction of the nozzle body (16) and connected to the high-pressure chamber, the guide recess (74) is designed like a blind hole and from the guide recess (74) to the low-pressure

Fuel return (46) an outlet bore (102), preferably tapering in a step-like manner, is formed on the intermediate part (66)

Guide recess (74) and the intermediate valve member (78) limited space and the outlet bore (102) belong to the valve chamber (44).

12. Fuel injector according to one of claims 1 to 7, characterized in that the housing (12) has a housing body (14) with the

High-pressure fuel inlet (24) and one

The nozzle body (16) is arranged, the intermediate part (66) being arranged in the intermediate element (122) in a receiving recess (122 ') open in the direction of the nozzle body (16) and connected to the high-pressure chamber, the guide recess (74) through the

Intermediate part (66) runs through and from the guide recess (74) to the low-pressure

Fuel return (46) an outlet bore (102), preferably tapering in steps, is formed on the intermediate element (122), the one of the guide recess (74) and the

Intermediate valve member (78) limited space and the outlet bore (102) belong to the valve chamber (44).

13. Fuel injector according to claim 8 or 11, characterized in that the intermediate valve seat (82) is formed on an at least approximately flat end face of the intermediate part (66).

14. Fuel injector according to claim 9, 10 or 12, characterized in that the guide recess (74) is limited on the side facing the control chamber (70) by a shoulder (126) of the intermediate part (66) forming the intermediate valve seat (82) and the head (80) is arranged in a head space (128) running from the shoulder (126) to the end face of the intermediate part (66).

15. Fuel injection valve according to one of claims 1 to 14, characterized in that the guide part (64) is formed by a guide sleeve (64 ') on which the compression spring (62) is supported, the compression spring (62) supporting the guide sleeve (64 ') to the

Intermediate part (66) presses sealingly.

16. Fuel injector according to one of claims 1 to 15, characterized in that the throttle passage (90) is temporarily closed during operation.

17. Fuel injection valve according to claim 16, characterized in that the control piston (68) of the injection valve member (56) on its

Intermediate valve (83) facing side has a cam-shaped projection (56 ') which at

Apply to the intermediate valve member (78)

Throttle passage (90) closed. 18. Fuel injection valve according to one of claims 1 to 17, characterized in that the throttle admission (96) opens into the valve chamber (44).

19. Fuel injector according to one of claims 1 to 18, characterized in that the

Throttle passage (90) opens into the control chamber (70) on a preferably flat end face of the head (80) facing the control piston (68).

20. Fuel injector for the intermittent injection of fuel into the combustion chamber of a

Internal combustion engine, with a housing (12) defining a longitudinal axis (L), which has a high-pressure fuel inlet (24) and an injection valve seat (18), a high-pressure chamber (26) arranged in the housing (12) and which extends from the high-pressure fuel inlet (24) to the injection valve seat ( 18), an injection valve member (56) which is arranged in the housing (12) and can be adjusted in the direction of the longitudinal axis (L) and which interacts with the injection valve seat (18), a compression spring (62) which pushes the injection valve member (56) in a counter-direction the injection valve seat (18) directed closing force is applied, a guide part (64) in which a control piston

(68) of the injection valve member (56) is guided in a sliding fit, an intermediate part (66) which, together with the guide part (64) and the control piston (68), delimits a control chamber (70), a hydraulic control device (72) for controlling the axial movement of the injection valve member (56) by changing the pressure in the control chamber ( 70), with an intermediate valve (83), the mushroom-shaped intermediate valve member (78) of which has a shaft (76) guided with a sliding fit in a guide recess (74) of the intermediate part (66) and a head (80) which is guided around the shaft (76) extending sealing surface (116) - in the closed position of the intermediate valve member (78) - rests against an intermediate valve seat (82) formed on the intermediate part (66), forming an annular sealing surface (112), one of the intermediate part (66), shaft (76) ) and head (80) bounded annular space (120), into which a high-pressure fuel inlet (86) connected to the high-pressure fuel inlet (24) opens, and an electrically operated actuator arrangement (38) for connecting en a valve chamber (44) connected to the high-pressure fuel inlet (24) via a throttle inlet (96) with and separation of the valve chamber (44) from a low-pressure fuel return (46), the intermediate valve member (78) separating the control chamber (70) from the valve chamber ( 44) - except for a throttle passage formed on the intermediate valve member (90) - separates, in the closed position of the

Intermediate valve member (78), the intermediate valve (83) separates the high-pressure fuel inlet (86) and the annular space (120) from the control chamber (70) and, when the intermediate valve member (78) is moved away from the closed position, the intermediate valve (83) forms a connection between the annular space (120) and the high-pressure fuel inlet (86) with the control chamber (70), characterized in that the housing (12) has a housing body (14) with the high-pressure fuel inlet (24) and a nozzle body (16) on which the injection valve seat (10) is formed , and an intermediate element (122) is arranged between the housing body (14) and the nozzle body (16), the intermediate part (66) being arranged in a blind hole-like receiving section (58 ') formed on the intermediate element (122), the guide recess ( 74) is designed like a blind hole and from the guide recess (74) to the low-pressure

Fuel return (46) an outlet bore (102), preferably tapering in steps, is formed on the intermediate part (66), the space delimited by the guide recess (74) and the intermediate valve member (78) and the outlet bore (102) belonging to the valve chamber (44) .

21. The fuel injector according to claim 20, characterized in that the throttle admission (96) is formed on the intermediate valve member (78).

22. Fuel injector according to claim 20 or 21, characterized in that a plunger (40) of the The actuator arrangement (38) runs through a passage (21) formed on the intermediate element (122) and is set up, preferably via one on the plunger

(40) formed sealing element (41), a low pressure outlet formed on the intermediate part (66)

(42) optionally to be closed or released.

23. Fuel injector according to one of claims 1 to 22, characterized in that the guide part (64) and the intermediate part (66) are designed as a one-piece component.