Fuel injection valve for internal combustion engine

Abstract

The fuel injection valve (10) includes a hydraulic control device (72) for controlling the axial movement of the injection valve element (56). A stem (76) of a mushroom-shaped intermediate valve element (78) of the intermediate valve (83) is engaged with a guide recess (74) of the intermediate part (66). In the valve open position, the intermediate valve element (78) opens the second connection (118, 117, 96) between the high-pressure fuel inlet (86) and the valve chamber (44). In the valve closed position, the intermediate valve element (78) closes the second connection (118, 117, 96) between the high-pressure fuel inlet (86) and the valve chamber (44). In the closed position, the intermediate valve member (78) defines a first annular sealing surface (121), and the side facing the intermediate piece (66) across the first sealing surface (111.2) defines a second annular sealing surface (122) and seats across the second sealing surface (112.2) on the intermediate valve seat (82). The first radial spacing (r1) is greater than the second radial spacing (r2).

Description

Technical Field

[0001] The present invention relates to a fuel injection valve that intermittently injects fuel into a combustion chamber of an internal combustion engine. Relates to.

Background Art

[0002] A fuel injection valve that intermittently injects fuel into a combustion chamber of an internal combustion engine is described, for example, in International Publication No. 2016 / 041739. The fuel injection valve includes a hydraulic control device that changes the pressure in a control chamber to control the axial movement of an injection valve body. The intermediate valve of the hydraulic control device has an intermediate valve body formed in a mushroom shape, and its shaft portion is tightly guided in a guide recess passing through an intermediate component. At the valve closing position of the intermediate valve body, the head of the intermediate valve body seats on an annular intermediate valve seat provided on the intermediate component, with a sealing surface provided at a radial interval from the shaft portion. The inner annular chamber defined by the intermediate component, the shaft portion, and the head through a high-pressure fuel supply port provided around the shaft portion and passing through the intermediate component is constantly connected to a high-pressure fuel inlet provided in the housing of the fuel injection valve. The intermediate valve constantly separates the control chamber and the valve chamber by a shaft portion guided with a tight fit by the intermediate component, except for a precisely sized throttle passage provided in the intermediate valve body that constantly connects the control chamber and the valve chamber. At the valve closing position of the intermediate valve body, the intermediate valve disconnects the high-pressure fuel supply port and the annular chamber from the control chamber, and when the intermediate valve body moves from the valve closing position, not only the annular chamber but also the connection between the high-pressure fuel supply port and the control chamber is blocked by the intermediate valve. The valve chamber can be connected to and disconnected from a low-pressure fuel return port by an electrically operated actuator assembly. When the injection operation is activated, the valve chamber is connected to the low-pressure fuel return port by the operation of the actuator assembly, and fuel from the control chamber flows into the valve chamber through the throttle passage of the intermediate valve body, resulting in a decrease in the pressure in the control chamber and the injection valve body lifting from the injection valve seat of the housing.

[0003] A further fuel injection valve is described in European Patent No. 1991773. While a control chamber and a valve chamber are constantly interconnected by a precision throttle passage, these two chambers are further separated from each other by an intermediate valve. The throttle passage is arranged so as to be directly adjacent to the control chamber. A passage having a cross-section larger than that of the throttle passage and communicating with the control chamber and connected to the high-pressure chamber of the injection valve is controlled by the intermediate valve. Since the cross-section of the outlet from the valve chamber controlled by the electric actuator assembly can also be made substantially larger than the cross-section of the throttle passage, the valve opening operation of the injection valve body is substantially a function only of the cross-section of the throttle passage. When the outlet from the valve chamber is blocked by the actuator assembly, the intermediate valve quickly opens, and the large-diameter passage connected to the high-pressure chamber is opened, thereby quickly terminating the injection operation.

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the case of a fuel injection valve, it is desired that reliable control of the valve opening operation of the injection valve body and quick closing operation of the injection valve body are possible, and the structure is not complicated.

[0005] The object of the present invention is to provide a fuel injection valve capable of at least partially improving the prior art.

Means for Solving the Problems

[0006] This object is achieved by a fuel injection valve having the features of the independent claims. Advantageous design embodiments of the present invention are described in the dependent claims as well as in this specification and the drawings.

[0007] The present invention relates to a fuel injection valve for intermittently injecting fuel into a combustion chamber of an internal combustion engine, which has a housing defining a longitudinal axis and is provided with a high-pressure fuel inlet and an injection valve seat. A high-pressure chamber extending from the high-pressure fuel inlet to the injection valve seat is arranged in the housing. Further, an injection valve body provided in the housing is position-adjustable in a direction along the longitudinal axis and cooperates with the injection valve seat.

[0008] The fuel injection valve preferably further comprises a compression spring that biases the injection valve body in a direction towards the injection valve seat with a closing force, is supported on one hand by the injection valve body, and is supported on the other hand so as to be stationary with respect to the housing, a guide portion in which a control piston of the injection valve body is slidably guided, an intermediate component that is integrated with the guide portion and the control piston to partition a control chamber, and a hydraulic control device that controls the axial movement of the injection valve body by changing the pressure in the control chamber.

[0009] The hydraulic control device comprises an intermediate valve body formed in a mushroom shape and having a shaft portion guided in a guide recess of the intermediate component and a head portion, and an intermediate valve having an intermediate valve seat provided on a side facing the head portion of the intermediate component and cooperating with the head portion.

[0010] In the open valve position, the intermediate valve body opens the connection between the high-pressure fuel supply port connected to the high-pressure chamber and the control chamber. In the closed valve position, the intermediate valve body cuts off the connection between the high-pressure fuel supply port and the control chamber and separates the control chamber from the valve chamber except for a throttle passage.

[0011] The fuel injection valve further includes an electrically actuated actuator assembly for connecting the valve chamber to a low-pressure fuel return port and disconnecting the valve chamber from the low-pressure fuel return port.

[0012] The head forms a first annular seal surface that is substantially closed in the surrounding direction by the side facing the intermediate component in the valve closing position of the intermediate valve element, crosses a first seal surface extending at a first radial interval with respect to the shaft portion or the guide recess, forms a second annular seal surface that is substantially closed in the surrounding direction, crosses a second seal surface extending at a second radial interval with respect to the shaft portion or the guide recess, seats on the intermediate valve seat, and is characterized in that the first radial interval is set larger than the second radial interval.

[0013] The guide part and the intermediate component can also be configured as separate components. However, it is also possible to integrally configure the guide part and the intermediate component.

[0014] The throttle passage is preferably provided in the intermediate valve element, and particularly preferably provided in the head of the intermediate valve element. However, the throttle passage can also be configured on the intermediate component. In a further variant, the throttle passage can be provided between the intermediate valve element and another component, for example, by means of a gap between the intermediate component or the guide component. The throttle passage configured in the intermediate valve element is recessed in the intermediate valve element on the side away from the control chamber and can be opened into a blind bore communicating with the valve chamber. The throttle passage of the intermediate valve element is preferably provided adjacent to the control chamber. The throttle passage and the blind bore are preferably provided coaxially with respect to the longitudinal axis. As a result, on the one hand, the throttle passage can be configured to have a desired length, and on the other hand, the blind bore can form a part of the valve chamber.

[0015] The first seal surface and the second seal surface are preferably toroidal surfaces arranged coaxially. Depending on the design embodiment, the first seal surface can be provided on the head, i.e., the side of the head facing the intermediate component, or on the intermediate component, i.e., the side of the intermediate component facing the head. Depending on the design embodiment, the second seal surface can be provided, in sequence, on the head, i.e., the side of the head facing the intermediate component, or on the intermediate component, i.e., the side of the intermediate component facing the head.

[0016] The head forms the first and second annular sealing surfaces and is sealed and received by the intermediate valve seat at the valve closing position of the intermediate valve body, thereby improving the fluid blocking property of the connection between the high-pressure fuel supply port and the control chamber at the valve closing position of the intermediate valve body. Further, except for the throttle passage, the disconnection of the control chamber from the valve chamber at the valve closing position of the intermediate valve body can be improved as a result, and by adapting the dimensions of the throttle passage, the axial movement of the injection valve body can be controlled more accurately, and thus the injection operation can be controlled more accurately. As a result of specific design embodiments of the sealing surface, for example, by the latter geometry or dimensions, the sealing characteristics of the intermediate valve can be adapted. While restricting or minimizing the adhesion force between the intermediate part and the intermediate valve body respectively, since the annular sealing surface is smaller compared to the mutually facing surfaces of the head and the intermediate part, the sealing performance of the intermediate valve here can be improved.

[0017] Furthermore, at the valve closing position of the intermediate valve body, it is preferable that an intermediate space, preferably an annular gap space, is formed between the annular sealing surface, the intermediate part, and the head. In a specific design embodiment, the annular sealing surface seals the intermediate space not only with respect to the valve chamber but also with respect to the control chamber. In a specific further design embodiment, the annular sealing surface communicates with the high-pressure fuel supply port to seal the intermediate space. As will be further described below, depending on the design embodiment, advantageously, a passage or a plurality of passages are provided in the intermediate part or the intermediate valve body, and the passage or the plurality of passages at the valve closing position of the intermediate valve body open into the intermediate space and can be configured so as not to cause any or negligible inhibitory effect on the control of the injection operation.

[0018] In a specific design embodiment, the annular gap space has a gap width of less than 1 mm, or less than 0.5 mm, or less than 0.1 mm, or less than 0.05 mm when measured in the direction of the longitudinal axis.

[0019] In one design embodiment, the high-pressure fuel supply port of the intermediate component is provided between the intermediate component and the head at the valve-closed position of the intermediate valve body and extends to open into an annular gap space radially partitioned by the first and second annular seal surfaces.

[0020] As a result of the high-pressure fuel supply port opening into the annular gap space partitioned by the intermediate component, the head, and the first and second annular seal surfaces at the valve-closed position of the intermediate valve body, the valve chamber and the control chamber at the valve-closed position of the intermediate valve body can be fluidly separated from the high-pressure fuel supply port or the high-pressure chamber by the sealing annular seal surfaces. This can minimize or avoid the leakage of fuel from the high-pressure chamber to the valve chamber or the control chamber through the high-pressure fuel supply port at the valve-closed position of the intermediate valve body, resulting in the advantage of improving the control accuracy of the injection operation.

[0021] In particular, since the first and second annular seal surfaces function to fluidly seal the high-pressure fuel supply port with respect to the valve chamber and the control chamber, the clearance between the shaft portion of the intermediate valve body and the guide recess of the intermediate component can be increased, and thus additional fluid sealing by guiding the shaft portion in the guide recess of the intermediate component becomes unnecessary. For example, the tight sliding fit of the shaft portion in the guide recess for reducing leakage as described in International Publication No. WO 2016 / 041739 is no longer essential. The potential increase in the clearance between the shaft portion and the guide recess advantageously simplifies the manufacture of the components, i.e., each of the intermediate valve body or the shaft portion and each of the intermediate component or the guide recess. In addition to the greater tolerances in the manufacture of the shaft portion and the intermediate component, since the guiding of the shaft portion in the guide recess no longer needs to additionally function from the perspective of fluid sealing, the height of the shaft portion along the axial direction, i.e., the longitudinal axis, can be further reduced. This advantageously enables a more compact structural form. Furthermore, as a result of the increased clearance, during the opening operation of the intermediate valve body to terminate the injection operation, the valve chamber is more rapidly filled with the fuel flowing between the shaft portion and the guide recess, and as a result, the injection operation can be terminated more rapidly.

[0022] The radial compressive force in the annular gap space, which can be disadvantageous in terms of the sealing effect of the annular seal surface, can be reduced by the annular gap space having a smaller dimension along the axial direction, i.e., the longitudinal axis, for example, compared to the length of the shaft portion.

[0023] As described above, the annular gap space can have a gap width of less than 1 mm, preferably less than 0.5 mm, less than 0.1 mm, or less than 0.05 mm when measured in the direction of the longitudinal axis.

[0024] However, instead of the annular gap space as described above, it is also possible to provide an intermediate space having a large dimension in the axial direction.

[0025] The high-pressure fuel supply port can be composed of a horizontal bore and a vertical bore in a longitudinal line of sight, and the vertical bore opens into the annular gap space in the closed valve position of the intermediate valve body.

[0026] In particular, the shaft portion can be guided in a sliding fit in the guide recess of the intermediate component such that a radial clearance of at least 10 μm, preferably 20 μm to 50 μm, is formed between the shaft portion and the guide recess.

[0027] In one design embodiment, the intermediate valve body has a supply port with a first end opening into the valve chamber and a second end opening towards the outside of the intermediate valve body, and in the closed valve position of the intermediate valve body, the second end is arranged at a position closer to the shaft portion in the radial direction than the second annular seal surface.

[0028] By providing a supply port, when the valve chamber is disconnected from the low-pressure fuel return port by the actuator assembly to end the injection operation, it is possible to quickly fill the valve chamber communicated with the supply port with fuel from the high-pressure chamber, and the opening operation of the intermediate valve can be promoted. In this specification, the side surface of the intermediate valve body is understood to mean the surface facing the guide recess of the intermediate part. Preferably, a blind bore protruding into the head and forming part of the valve chamber is provided on the shaft portion of the intermediate valve body, and it is desirable that the blind bore be provided on the end side facing away from the head. In such a design embodiment, the supply port via the first end can open into the blind bore.

[0029] The inner annular chamber adjacent to the shaft portion and the second annular seal surface is provided between the intermediate part and the head at the closed position of the intermediate valve body. At the closed position of the intermediate valve body, it is preferable that the supply port communicates the inner annular chamber with the valve chamber.

[0030] The supply port can open outward of the shaft portion or the head via the second end. In a variant, the second end of the supply port is arranged on the line where the shaft portion is adjacent to the head. The supply port can be configured as an inclined bore or a horizontal bore with respect to the longitudinal axis.

[0031] In one design embodiment, the supply port has a diameter larger than the minimum diameter of the low-pressure fuel return port. As a result of the large diameter of the supply port, it is possible to achieve a quick filling of the valve chamber, which has an advantageous effect on the opening operation of the intermediate valve. Since the supply port is fluidly disconnected from the high-pressure chamber by the second end at the closed position of the intermediate valve body, the large dimensions of the supply port can be achieved without generating additional leaks in particular.

[0032] In one design embodiment, the shaft portion has at least one surrounding annular protrusion and is guided by a guide recess via the at least one surrounding annular protrusion.

[0033] By providing an annular protrusion, a throttle path surrounding the shaft portion can be formed in the axial direction between the shaft portion and the guide recess. The throttle path formed by the annular protrusion has the advantage that it can cause turbulent flow rather than laminar flow in the fluid flowing longitudinally through the intermediate space between the shaft portion and the guide recess. In particular, the radial allowable clearance range between the shaft portion and the guide recess can be further enlarged.

[0034] In one design embodiment, the shaft portion has two annular protrusions arranged at intervals in the longitudinal direction of the shaft portion.

[0035] By providing two surrounding annular protrusions arranged at intervals in the longitudinal direction of the shaft portion, two throttle passages surrounding the shaft portion and arranged in series in the longitudinal direction can be provided in the longitudinal direction. As a result, the formation and generation of turbulent flow of the fluid flowing through the intermediate space between the shaft portion and the guide recess can be further promoted.

[0036] In the design embodiment having two annular protrusions spaced apart from each other in the longitudinal direction of the shaft portion, due to the effect as a throttle passage arranged in series, the radial clearance between the shaft portion and the guide recess can be further increased.

[0037] In particular, here the shaft portion can be guided by the guide recess of the intermediate component so that a radial clearance of at least 50 μm, preferably 70 μm to 100 μm, is formed between the shaft portion and the guide recess.

[0038] In one design embodiment, the intermediate valve body communicates with the valve chamber, and in the closed valve position of the intermediate valve body, a valve chamber passage is provided between the intermediate component and the head, and extends to open into an annular gap space radially partitioned by the first and second annular seal surfaces.

[0039] As a result of such an arrangement, the valve chamber passage can advantageously be sealed against the control chamber and the high-pressure fuel supply port in the closed valve position of the intermediate valve body. This allows, for example, the diameter of the valve chamber passage to be made larger compared to the diameter of the throttle passage, and as a result, leakage from the control chamber or the high-pressure fuel supply port to the valve chamber passage or the valve chamber can be avoided from being promoted respectively in the closed valve position of the intermediate valve body. Also, due to the large size of the valve chamber passage, when the intermediate valve body moves from the closed valve position, it is possible to quickly discharge the valve chamber through the valve chamber passage, and there is an advantage that the injection operation can be quickly terminated.

[0040] In one design embodiment, the fuel injection valve has an annular chamber defined by an intermediate part, a shaft part, and a head part in the closed valve position of the intermediate valve body, and the high-pressure fuel supply port opens into the annular chamber.

[0041] The annular chamber preferably has an inner annular chamber that penetrates radially around the shaft part and is defined by the shaft part and the intermediate part, and preferably, a recess is provided in the shaft part itself, and the high-pressure fuel inlet preferably opens into the inner annular chamber.

[0042] The annular chamber preferably has an annular gap space adjacent to the inner annular chamber and formed by an enclosed gap between the intermediate part and the head of the intermediate valve body in the closed valve position of the intermediate valve body.

[0043] In the closed valve position of the intermediate valve body, the annular gap space can have at least a substantially constant gap width. The gap width here is preferably at least five times smaller than the inner annular chamber when measured in the direction of the longitudinal axis in each case.

[0044] By using the annular chamber of such an embodiment, the adhesive force can be further reduced.

[0045] The inner annular chamber of the shaft portion of the intermediate valve body preferably opens radially outward and has dimensions such that, in a longitudinal line of sight, the throat of the high-pressure fuel supply port is always at least substantially completely located within the region of the annular groove, formed by the surrounding annular groove. The annular groove is more preferably directly adjacent to the head. Thereby, advantageously, the structure of the intermediate component can be simplified.

[0046] The entire throat of the high-pressure fuel supply port is preferably in the region of the inner annular chamber. This eliminates the need for an intermediate component's potentially required angled bore.

[0047] The annular groove preferably has a trapezoidal cross-section with slanted sides extending away from the head. In the valve-opening position of the intermediate valve body, fuel flowing through the high-pressure fuel supply port via this side can be deflected in the direction towards the head with little loss.

[0048] In a design embodiment where the intermediate valve body has a valve chamber passage communicating with the valve chamber, opening into the annular gap space in the valve-closed position of the intermediate valve body, and the high-pressure fuel supply port opens into an annular chamber defined by the intermediate component, the shaft portion, and the head, the shaft portion is preferably guided in a tight fit in the guide recess of the intermediate component, preventing or minimizing leakage from the high-pressure fuel supply port through the guide of the shaft portion to the valve chamber.

[0049] In one design embodiment, the high-pressure fuel supply port, or the second passage connecting the high-pressure chamber to the valve chamber respectively, is provided in the intermediate valve body, preferably in the shaft portion. Alternatively or additionally, the second passage can also be provided in the intermediate component.

[0050] The second passage preferably opens into the valve chamber, preferably into a blind bore of the shaft portion, by a radially extending rectangular throttle bore.

[0051] The second side passage is preferably connected to the high-pressure chamber via an annular chamber defined by the intermediate component, the shaft portion, and the head in the valve-closed position of the intermediate valve body.

[0052] In one design embodiment, the second passage can extend from the annular groove, preferably from its radially inner base, preferably radially into the valve chamber in the longitudinal line of sight. Alternatively, the shaft portion of the intermediate valve body can have a preferably groove-shaped pocket recess extending from the annular groove, from where the second passage preferably extends radially into the valve chamber in the longitudinal line of sight as well. In embodiments having pocket recesses, preferably two pocket recesses facing each other radially are provided on the shaft portion in order to obtain symmetrical pressure conditions.

[0053] In one design embodiment, the valve chamber passage provided in the head has a bore parallel or inclined to the longitudinal axis and opens into the annular gap space in the closed valve position of the intermediate valve body.

[0054] Furthermore, the valve chamber passage provided in the head preferably has a horizontal bore connecting a bore parallel to the longitudinal axis or a bore inclined to the longitudinal axis and a blind bore.

[0055] The intermediate valve body can also have two or more valve chamber passages each opening into the annular gap space. Thereby, a plurality of parallel or inclined bores communicating with the respective valve chamber passages can be provided in the head, and the bores each open into the annular gap space.

[0056] The first annular seal bead having the first end face forming the first seal face is preferably provided on the side facing the intermediate part of the head or on the side of the intermediate part facing the head.

[0057] The seal bead has the advantage that it can perform a reliable fluid seal while forming an annular seal face, and at the same time can reduce or minimize the adhesion force between the intermediate part and the intermediate valve body respectively.

[0058] The second annular seal bead having the second end face forming the second seal face is preferably provided on the side facing the intermediate part of the head or on the side of the intermediate part facing the head.

[0059] In a design embodiment where a sealing bead is provided on the head, typically, the plane of the intermediate part facing the sealing bead forms an intermediate valve seat. In a design embodiment where the sealing bead is provided on the intermediate part, typically, the end face of the sealing bead forms an intermediate valve seat and forms a sealing surface that cooperates as a sealing means with the plane of the head facing the sealing bead. In a design embodiment where the first and second sealing beads are provided on the intermediate part, the intermediate valve seat can be formed by the end faces of the first sealing bead and the second sealing bead.

[0060] Both the first sealing bead and the second sealing bead are preferably provided on the head, or both are preferably provided on the intermediate part. However, one of the sealing beads may be provided on the head and the other on the intermediate part.

[0061] In one design embodiment, the intermediate part on the side facing the head has at least one gradient in the radial direction, the head on the side facing the intermediate part has at least one gradient in the radial direction, and at the closed valve position of the intermediate valve body, the mutually offset edges of the gradients of the intermediate part and the head radially delimit the first and / or second annular sealing surfaces respectively.

[0062] The step of the intermediate part or the head is usually provided so as to surround the shaft part or the guide recess. The step of the intermediate part or the head can be formed by an undercut or a protrusion. The step of the intermediate part and / or the head can have a vertical plane and a horizontal plane in the longitudinal line of sight. However, alternatively or additionally, the step can also have a chamfered or curved surface. In this specification, in particular, a step formed by the periphery of the head or the intermediate part can also be considered as a step. The dimensions of the first and / or second annular seal surfaces can advantageously be adapted by the suitable dimensions of the step. Further, by a suitable configuration of the gradient and / or in combination with one or more seal beads, one or more intermediate spaces, in particular an annular gap space, are formed in the closed valve position of the intermediate valve body, and one or more passages, such as a valve chamber passage, a high-pressure fuel supply port, etc., can potentially be opened to the intermediate space.

[0063] In one design embodiment, the step of the intermediate part forms an inner annular chamber defined by the intermediate part, the shaft part, and the head in the closed valve position of the intermediate valve body.

[0064] The shaft part is preferably always guided by the guide recess of the intermediate part.

[0065] The housing of the fuel injection valve preferably has a housing body having a high-pressure fuel inlet and a nozzle body provided with an injection valve seat. The intermediate part, and thus the intermediate valve, are preferably provided within the nozzle body. In the longitudinal line of sight, it advantageously enables an elongated embodiment of the housing body and an elongated embodiment of the injection valve body.

[0066] In a further design embodiment, the housing comprises a housing body having a high-pressure fuel inlet and a nozzle body provided with an injection valve seat. However, the intermediate part, and thus the intermediate valve, are arranged between the housing body and the nozzle body. This advantageously enables slimming down of the nozzle body.

[0067] In one design embodiment, the guide recess is provided in the form of a blind bore (opening in the direction towards the control chamber), where an outlet bore from the guide recess, preferably from the latter's base, to the low-pressure fuel return port is provided in the intermediate part. This outlet bore is preferably formed to taper stepwise as seen from the guide recess.

[0068] Alternatively, for example, as disclosed in the figures, a two-part solution can also be applied, which is also disclosed in FIGS. 2 to 4, FIGS. 8 and 9 of WO 2016 / 041739, or FIGS. 2, 4, 5, 7 and 8 of WO 2007 / 098621. For example, an intermediate element may be adjacent above the intermediate part, the outlet bore can be configured within the intermediate element, and the guide recess can be provided as a continuous bore within the intermediate part. The intermediate element is preferably formed in a plate shape.

[0069] The valve chamber usually includes a chamber defined by the intermediate valve body and the guide recess, particularly a chamber defined by the end face of the shaft portion facing the low-pressure fuel return port, the outlet bore, and the blind bore of any intermediate valve body.

[0070] The throat portion of the outlet bore facing the low-pressure fuel return port preferably forms a low-pressure outlet.

[0071] In a further design embodiment, the housing comprises a housing body having a high-pressure fuel inlet and a nozzle body provided with an injection valve seat. If an intermediate body is provided between the housing body and the nozzle body, the intermediate parts are each provided in the intermediate body or are preferably received by the latter. For this purpose, preferably, the intermediate body opens in the direction towards the nozzle body, communicates with the high-pressure chamber, and has a receiving recess in which the intermediate parts are provided. The intermediate body here can be part of the actuator assembly.

[0072] The tappets of the actuator assembly preferably pass through corresponding passages in the intermediate part so as to close or open the low-pressure outlets provided in the intermediate part respectively. Here, the intermediate body preferably forms a guide element for the tappets. The housing body is preferably supported in a sealed manner on one end side of the intermediate body, and the nozzle body is supported in a sealed manner on the end side opposite to the intermediate body.

[0073] In one design embodiment, the guide recess on the side facing the control chamber is provided in the intermediate part and is delimited by a shoulder that retreats with respect to the end side facing the nozzle body, and this shoulder can be provided with an intermediate valve seat. As a result, a head space capable of receiving the head of the intermediate valve body can be formed between this shoulder and the end side of the intermediate part facing the nozzle body. In this embodiment, the end facing the latter intermediate part can form a stop for defining the stroke of the intermediate valve body, and the guide part can be simplified.

[0074] The guide part is preferably formed by a cylindrical guide sleeve that supports a compression spring, and the compression spring presses the guide sleeve against the intermediate part in a sealed state as a result.

[0075] In the operation of the fuel injection valve, the throttle passage can be temporarily closed to reduce fuel loss. This is, on the one hand, the case as defined in the following paragraphs. On the other hand, for example, as known from WO 2018 / 162747 and DE 19516565, the throttle passage may be temporarily blocked by a shut-off valve.

[0076] In one design embodiment, the control piston of the injection valve body on the side facing the intermediate valve is supported on the intermediate valve body and has a cam-shaped protrusion capable of closing the throttle passage.

[0077] The present invention further relates to a fuel injection valve for intermittently injecting fuel into a combustion chamber of an internal combustion engine, comprising a housing defining a longitudinal axis and having a high-pressure fuel inlet and an injection valve seat, a high-pressure chamber provided in the housing and extending from the high-pressure fuel inlet to the injection valve seat, an injection valve body provided in the housing so as to be adjustable in the direction of the longitudinal axis and cooperating with the injection valve seat, a compression spring biasing the injection valve body by a closing force directed towards the injection valve seat, a guide portion slidably guiding a control piston of the injection valve body, an intermediate component partitioning a control chamber together with the guide portion and the control piston, an intermediate valve body having a shaft portion and a head portion formed in a mushroom shape and guided by a guide recess of the intermediate component, and an intermediate valve including an intermediate valve seat provided on a side facing the head of the intermediate component and cooperating with the head. The intermediate valve body opens a first connection between a high-pressure fuel supply port connected to the high-pressure chamber and the control chamber in the open valve position, shuts off the first connection between the high-pressure fuel supply port and the control chamber in the closed valve position, and separates the control chamber from the valve chamber except for a throttle passage. An hydraulic control device controls the axial movement of the injection valve body by adjusting the pressure in the control chamber, and an electrically operable actuator assembly connecting the valve chamber to a low-pressure fuel return port and disconnecting it from the valve chamber. The intermediate valve body is characterized in that it opens a second connection between the high-pressure fuel supply port and the valve chamber in the open valve position and shuts off the second connection between the high-pressure fuel supply port and the valve chamber in the closed valve position.

[0078] As a result of the second connection between the high-pressure fuel supply port and the valve chamber being opened, the valve chamber is filled with fuel via the second connection due to the intermediate valve element being in the open valve position, thereby enabling a more rapid opening operation of the intermediate valve element. In particular, the second connection improves the filling of the valve chamber compared to a fuel injection valve in which the filling of the valve chamber is effected only from the control chamber via, for example, a throttle passage. That is, advantageously, when the opening operation of the intermediate valve element is small, the valve chamber can already be filled in the manner of the second connection. With regard to the throttle passage, since the throttle passage causes the flow of fuel from the control chamber to the valve chamber to trigger the initial opening operation of the intermediate valve element, it is advantageously sufficient here, and thereafter the valve chamber can be filled with a large amount of fuel by the second connection.

[0079] By the intermediate valve element located in the closed valve position blocking the second connection between the high-pressure fuel supply port and the valve chamber, it is possible to advantageously avoid the fuel from flowing from the high-pressure chamber to the low-pressure fuel return port through the second connection at the closed valve position of the intermediate valve element. In an example where additional filling of the valve chamber is achieved by a second passage within an intermediate component or the intermediate valve element, the second passage constantly connects the high-pressure chamber and the valve chamber, and the fuel passing through the valve chamber can also flow to the low-pressure fuel return port during the injection operation, i.e., at the closed valve position of the intermediate valve element, which may result in an adverse loss of fuel and an increase in wear as a result of fuel leakage from the high-pressure chamber. By blocking the second connection between the high-pressure fuel supply port and the valve chamber at the closed valve position of the intermediate valve element, it is possible to reduce or minimize, respectively, the adverse loss of fuel and wear resulting from fuel leakage from the high-pressure chamber into the valve chamber during the injection operation, and at the same time achieve a rapid filling of the valve chamber for the opening operation of the intermediate valve element.

[0080] In one design embodiment, the second connection passes between the high-pressure fuel supply port and a bore passing through the shaft portion of the intermediate valve element, and the bore is part of the valve chamber. The bore is preferably provided as a blind bore.

[0081] In one design embodiment, in the closed valve position of the intermediate valve body, the side of the head facing the intermediate component crosses the first seal surface extending at a first radial interval with respect to the shaft portion or the guide recess, and at the same time, in the circumferential direction, forms a substantially closed first annular seal surface, crosses the second seal surface extending at a second radial interval with respect to the shaft portion or the guide recess, and at the same time forms a second annular seal surface substantially closed in the circumferential direction, and is pressed against the intermediate valve seat, and the first radial interval is characterized by being larger than the second radial interval.

[0082] In one design embodiment, the first annular seal bead having the first end surface forming the first seal surface is provided on the side of the head facing the intermediate component or on the side of the intermediate component facing the head.

[0083] In one design embodiment, the second annular seal bead having the second end surface forming the second seal surface is provided on the side surface of the head facing the intermediate component or on the side surface of the intermediate component facing the head.

[0084] In one design embodiment, the intermediate component on the side facing the head has at least one stepped portion, the head on the side facing the intermediate component has at least one stepped portion, and in the closed valve position of the intermediate valve body, the mutually offset edges of the stepped portions of the intermediate component and the head radially delimit the first and / or second annular seal surfaces respectively.

[0085] In one design embodiment, the stepped portion of the intermediate component forms an inner annular chamber delimited by the intermediate component, the shaft portion, and the head in the closed valve position of the intermediate valve body.

[0086] In one design embodiment, the high-pressure fuel supply port of the intermediate component is provided between the intermediate component and the head in the closed valve position of the intermediate valve body and extends to open into an annular gap space radially delimited by the first and second annular seal surfaces.

[0087] In one design embodiment, the second connection comprises a supply port in the intermediate valve body, the first end of which opens into the valve chamber and the second end of which opens towards the outside of the intermediate valve body. As previously mentioned, the valve chamber can be advantageously filled by the supply port to facilitate the opening of the intermediate valve body. The supply port via the first end preferably opens into a blind bore that passes through the stem and is part of the valve chamber.

[0088] In one design embodiment, the supply port through the second end opens outward from the intermediate valve body so that in the closed position of the intermediate valve body, the second end is located radially closer to the shaft portion than the second annular sealing surface.

[0089] In one design embodiment, the second connection consists of a passage formed by a radial clearance between the shank and the guide recess, said clearance being at least 10 μm, preferably between 20 μm and 50 μm.

[0090] In one design embodiment, the stem has two annular projections spaced apart from one another in the longitudinal direction of the stem.

[0091] In one design embodiment, the surrounding annular projections each have at least one chamfer, and the second connection defines a passage formed by an intermediate space between the at least one chamfer and the guide recess. The at least one chamfer allows the clearance between the shank and the guide recess to be kept sufficiently small, which improves the centering of the shank and thus prevents or minimizes eccentricity or tilting of the shank. The at least one chamfer between the shank's side surface and the guide recess simultaneously defines a sufficient passage formed by an intermediate space between the at least one chamfer and the guide recess despite the small clearance, which can serve as a passage for the second connection.

[0092] In a design embodiment, the surrounding annular projections each have two or three chamfers.

[0093] In one design embodiment (without annular protrusions), the shaft portion has at least one chamfer in the circumferential direction, and the second connection forms a passage formed by an intermediate space between at least one chamfer and the guide recess. As described above, with at least one chamfer, it is possible to keep the clearance between the shaft portion and the guide recess sufficiently small, thereby improving the centering of the shaft portion and, in turn, centering the shaft portion while avoiding or minimizing eccentricity or inclination of the shaft portion. At least one chamfer between the side surface of the shaft portion and the guide recess forms a sufficient passage formed by the intermediate space between at least one chamfer and the guide recess simultaneously despite a small clearance, and this passage can function as the passage of the second connection.

[0094] In one design embodiment, the shaft portion has two or three chamfers in the circumferential direction.

[0095] In one design embodiment, the second connection consists of a bore that penetrates the head of the intermediate valve body and at least partially forms a valve chamber passage, and this bore communicates with the valve chamber and opens on the side facing the intermediate part of the head at one end side.

[0096] In one design embodiment, the valve chamber passage of the intermediate valve body, in the closed valve position of the intermediate valve body, is provided between the intermediate part and the head and extends to open into an annular gap space radially partitioned by the first and second annular seal surfaces.

[0097] In one design embodiment, the fuel injection valve has an annular chamber defined by the intermediate part, the shaft portion, and the head and into which the high-pressure fuel supply port opens in the closed valve position of the intermediate valve body.

Brief Description of the Drawings

[0098] Embodiments of the present invention will be described in more detail with reference to the drawings and the description accompanying the drawings. [Figure 1] It is an explanatory diagram showing a longitudinal section of a fuel injection valve according to the prior art. [Diagram 2]It is a view showing an enlarged part surrounded by a rectangle indicated by II in FIG. 1 among fuel injection valves according to the prior art. [Figure 3] It is a view showing a part in the longitudinal section of the first embodiment of the fuel injection valve according to the present invention, and this part shows the region of the fuel injection valve corresponding to the part surrounded by the rectangle indicated by III in FIG. 2. [Figure 4] It is a view showing a part in the longitudinal section of the second embodiment of the fuel injection valve according to the present invention, and this part shows the region of the fuel injection valve corresponding to the part surrounded by the rectangle indicated by III in FIG. 2. [Figure 5] FIG. 5a is a view showing a part in the longitudinal section of the third embodiment of the fuel injection valve according to the present invention, and this part shows the region of the fuel injection valve corresponding to the part surrounded by the rectangle indicated by III in FIG. 2. FIG. 5b is a part of an explanatory view of a horizontal section showing a further embodiment of the fuel injection valve according to the present invention. [Figure 6] It is a view showing a part in the longitudinal section of the fourth embodiment of the fuel injection valve according to the present invention, and this part shows the region of the fuel injection valve corresponding to the part surrounded by the rectangle indicated by III in FIG. 2. [Figure 7] It is a view showing a part in the longitudinal section of the fifth embodiment of the fuel injection valve according to the present invention, and this part shows the region of the fuel injection valve corresponding to the part surrounded by the rectangle indicated by III in FIG. 2.

MODE FOR CARRYING OUT THE INVENTION

[0099] In the description of the drawings, the same reference numerals are given to parts equivalent to the embodiments.

[0100] FIG. 1 shows a fuel injection valve 10' according to International Publication No. 2016 / 041739 for intermittently injecting fuel into the combustion chamber of an internal combustion engine. The fuel here is at high pressure and is pressurized, for example, up to a pressure of 2000 bar or more at maximum.

[0101] The fuel injection valve 10' has a housing 12' that defines a longitudinal axis L, a housing body 14', a nozzle body 16' in which an injection valve seat 18' is formed, and an actuator receiving body 20' disposed between the housing body 14' and the nozzle body 16'. A union nut 22' supported by the nozzle body 16' receives the actuator receiving body 20' and is fitted to the housing body 14' by a screw. The housing body 14', the actuator receiving body 20', and the latter and the nozzle body 16' are received by each other on the end side and are mutually compressed in a sealed manner by the union nut 22' and aligned with each other in the direction of the longitudinal axis L.

[0102] The outer shape of the housing 12' is at least approximately cylindrical in a known manner.

[0103] The high-pressure fuel inlet 24' is disposed on the end side of the housing body 14' facing away from the nozzle body 16'. The high-pressure chamber 26' provided inside the housing 12' from the high-pressure fuel inlet 24' extends through the housing body 14', the actuator receiving body 20', and the nozzle body 16' to the injection valve seat 18'. The high-pressure fuel inlet 24' is formed by a check valve 30' and a valve carrier 28' carrying a basket-type perforated filter 32' that captures potential foreign matter in the fuel. The disk-shaped valve body of the check valve 30' has a bypass bore and cooperates with a valve seat provided on the valve carrier 28'.

[0104] The check valve 30' allows fuel supplied via a high-pressure supply path in a known manner to flow into the high-pressure chamber 26' substantially unobstructed, but blocks the outflow of fuel from the high-pressure chamber 26' to the high-pressure supply path except via the bypass path.

[0105] The structure and functional mode of the module configured as a cartridge having a valve carrier 28', a check valve 30', and a perforated filter 32' are disclosed in International Publication No. WO 2014 / 131497. The high-pressure fuel inlet 24' and the valve carrier 28' having the check valve 30' and the perforated filter 32' can also be configured as disclosed in International Publication No. WO 2013 / 117311. Potential embodiments of the high-pressure fuel inlet 24' and the check valve 30', and the use of a tubular filter instead of the perforated filter 32' are known from International Publication No. WO 2009 / 033304. The corresponding disclosures of the above-mentioned documents are incorporated into the present embodiment by reference.

[0106] The high-pressure chamber 26' is provided on the housing body 14' adjacent to the valve carrier 28' and has a separate storage chamber 34' on the other hand connected to the injection valve seat 18' via the flow path duct 36' of the high-pressure chamber 26'.

[0107] The dimensions and functional mode of the separate storage chamber 34' in conjunction with the check valve 30' having a bypass are disclosed in International Publication No. WO 2007 / 009279, and the corresponding disclosure is incorporated into the present disclosure by reference.

[0108] In a particular embodiment, a constant fixed orifice may be provided instead of the check valve 30'.

[0109] The electrically actuated actuator assembly 38' is received in a recess of the actuator receiving body 20' in a known manner, spring-biased in one direction by the tappet 40', and movable in the other direction by the solenoid of the actuator assembly 38'. The actuator assembly 38' is specified to close the low-pressure outlet 42' (see Figure 2), and also to open the low-pressure outlet 42' and interconnect the valve chamber 44' and the low-pressure fuel return 46'. The longitudinal axis indicated by the reference numeral 48' of the tappet 40' extends parallel and eccentric to the longitudinal axis L of the actuator assembly 38'.

[0110] The duct 52´ through which the electric control line for controlling the actuator assembly 38´ is inserted extends from the electric connector 50´ through the housing body 14´ to the actuator assembly 38´, and is provided in parallel to the longitudinal axis L of the housing 12´, i.e., to the separate storage chamber 34´ arranged eccentrically with respect to the fuel injection valve 10´.

[0111] The tappet 40´ penetrates the bottom of the cup-shaped actuator receiving body 20´ that forms the guide element of the tappet 40´. The tappet 40´ has radially protruding guide wings, by which the tappet 40´ is guided slidably and displaceably parallel to the longitudinal axis L on the guide element. The guide wings form a passage extending along the longitudinal axis L, through which fuel can flow from the low-pressure outlet 42´ to the low-pressure fuel return port 46´.

[0112] FIG. 2 shows an enlarged view in the rectangular region indicated by II of the fuel injection valve of FIG. 1.

[0113] The conical injection valve seat 18´ directly connected to the storage chamber 34´ via the flow duct 36´ and thus to the high-pressure fuel inlet 24´ is integrally formed with the nozzle body 16´.

[0114] When viewed in the fuel flow direction, when the injection valve body 56´ lifts from the injection valve seat 18´, the injection port 54´ through which very high-pressure fuel is injected into the combustion chamber of the internal combustion engine is provided in a known manner in the hemispherical free end region of the nozzle body 16´ downstream of the injection valve seat 18´.

[0115] The injection valve body 56´ is formed in a needle shape and cooperates with the injection valve seat 18´. The injection valve body 56´ is guided movably in the direction of the longitudinal axis L within the guide bore 57´ of the nozzle body, and the guide bore 57´ is coaxial with the longitudinal axis L and communicates with the high-pressure chamber 26´, and fuel can flow to the injection valve seat 18´ and the injection port 54´ with little loss through the recess on the injection valve body 56´, and the recess extends outwardly in the longitudinal and radial directions.

[0116] The internal space 58' of the nozzle body 16' communicating with the high-pressure chamber 26' is formed so as to widen to twice the width toward the actuator receiving body 20' on the upstream side of the guide bore 57', and has a constant cross-section of the nozzle body 16' up to the end face facing the actuator receiving body 20' of the internal space 58' so as to be substantially coaxial in the longitudinal direction, and defines an inner cylindrical portion 60'.

[0117] A support ring for supporting one end of the compression spring 62' is integrally formed on the injection valve body 56' between the cylindrical portion 60' and the guide bore 57'. The compression spring 62' is supported at the other end by a guide sleeve 64'' forming a guide portion 64'. The compression spring 62' applies a closing force acting in the direction toward the injection valve seat 18' to the injection valve body 56'. On the other hand, the compression spring 62' holds the guide portion 64' or the guide sleeve 64'' by the end face facing away from the compression spring 62', and serves as a sealing means for the intermediate component 66'. Note that the guide portion 64' can have a shape other than a sleeve, such as a cube or an annular body.

[0118] The double-acting control piston 68' integrally formed on the injection valve body 56' is guided so as to be displaceable in the longitudinal axis L direction by a fitting of about 3 μm to 5 μm with the guide portion 64' or the guide sleeve 64'', respectively. The control piston 68', the guide portion 64', or the guide sleeve 64'' each define a control chamber 70' with respect to the high-pressure chamber 26' by an intermediate component 66'. The intermediate component 66' is part of a hydraulic control device 72'.

[0119] Figure 3 is a longitudinal section through part of a first embodiment of a fuel injector 10 according to the invention. This part shows the area of the fuel injector 10 inside the rectangle designated III in Figure 2. This particular embodiment of this area of the first embodiment of the fuel injector 10 according to the invention differs from the fuel injector 10' according to WO 2016 / 041739 shown in Figure 2, in particular with respect to the hydraulic control device 72, which will be explained below with reference to Figure 3. The remaining area of the first embodiment of the fuel injector 10 outside the rectangle designated III substantially corresponds to the fuel injector 10' shown in Figures 1 and 2. This also applies in an analogous manner to parts of further embodiments of the fuel injector 10 according to the invention, which are shown in Figures 4 to 7.

[0120] A cylindrical guide recess 74 penetrates the intermediate part 66 from its flat end facing the control chamber 70 to its flat end facing away from the control chamber 70. The guide recess 74 guides a stem 76 of a mushroom-shaped intermediate valve body 78. A head 80 of the intermediate valve body 78, which is integral with the stem 76, is located in the control chamber 70 and cooperates with the intermediate part 66 with its side surface facing the intermediate part 66, and its flat end surface forms an annular intermediate valve seat 82.

[0121] The intermediate valve body 78 constitutes an intermediate valve 83 together with an intermediate valve seat 82 provided on the intermediate part 66 .

[0122] The first toroidal seal bead 111 is provided on the side facing the intermediate part 66 of the head 80. It has a first end face 111.1 that forms a first seal face 111.2, and a second end face 112.1 that forms a second seal face 112.2 provided at a first radial interval r1 from the shaft portion 76. The second toroidal sealing bead 112, which is provided at a second radial interval r2 from the shaft portion 76, is further provided on the side of the head 80 facing the intermediate part 66. As shown in FIG. 3, the intermediate valve body 78 crosses the first seal face 111.2 while forming a first annular seal face 121 that is closed so as to surround the side facing the intermediate part 66, and crosses the second seal face 112.2 while forming a second annular seal face 122 that is closed so as to surround it, and the head 80 is positioned in a valve-closed posture where it seats on the intermediate valve seat 82. Here, the first radial interval r1 is larger than the second radial interval r2 from the shaft portion 76.

[0123] The high-pressure fuel supply port 86, which communicates with the high-pressure chamber 26 and includes a horizontal bore 861 and a vertical bore 862, penetrates the intermediate part 66. The vertical bore 862 in the valve-closed position of the intermediate valve body 78 is provided between the intermediate part 66 and the head 80 and opens into an annular gap space 118 radially partitioned by the first and second annular seal faces 121, 122. As can be understood from FIG. 3, a plurality of high-pressure fuel supply ports 86 can be provided. A second, optional high-pressure fuel supply port 86 is indicated by a dashed line in the region of the intermediate part 66 on the right side in FIG. 3.

[0124] A clearance of at least 10 μm is preferably provided radially between the shaft portion 76 and the guide recess 74. However, the clearance may also be smaller, for example, between 3 and 10 μm. In a further embodiment, the clearance can be larger in each case, for example, a value between 20 μm and 50 μm. The second radial distance r2 of the second annular seal surface 122 from the shaft portion 76 here is larger than the clearance (for example, several 1 / 10 mm larger). By sealing the high-pressure fuel supply port 86 at the valve closing position of the intermediate valve body 78 by the annular seal surfaces 121, 122, the possibility of additional leakage into the valve chamber 44 resulting from the clearance between the shaft portion 76 and the guide recess 74 is minimal or negligible. Furthermore, it is clear that the shaft portion 76 resulting from this can be configured to be shorter along the longitudinal axis L compared to the prior art, such as in a fuel injection valve according to WO 2016 / 041739. Furthermore, since the intermediate component 66 can also be designed to be shorter in the direction of the longitudinal axis L, a more compact structural configuration becomes possible.

[0125] Despite the reliable sealing of the high-pressure fuel supply port 86 at the valve closing position of the intermediate valve body 78, the adhesion between the head 80 and the intermediate component 66 remains minor due to the sealing of the intermediate valve body 78 by the two annular seal surfaces 121, 122.

[0126] The intermediate element 98, with an outlet bore 102 that tapers stepwise and is connected to the guide recess 74 via one end and forms a low-pressure outlet 42 via the other end, is arranged adjacent above the intermediate component 66 in FIG. 3. The outlet bore 102 is arranged eccentrically with respect to the longitudinal axis L. In a particular embodiment, the intermediate element 98 is configured to be integrated with the intermediate component 66, i.e., as a single-piece intermediate component, in which case the guide recess 74 is configured as a blind bore (see, for example, FIG. 5a).

[0127] The length of the shaft portion 76 in the longitudinal axis L direction is set with respect to the guide recess 74 such that a flow gap 100 remains between the end side facing the outlet bore 102 of the shaft portion 76 and the intermediate element 98 at the valve closing position of the intermediate valve body 78.

[0128] The shaft portion 76 of the intermediate valve body 78 has, at a first end, a blind bore 92 which penetrates the shaft portion 76 and is part of the valve chamber 44, and at a second end on the outer side, a supply port 96 which opens towards a line adjacent to the head 80.

[0129] At the valve closing position of the intermediate valve body 78, an inner annular chamber 117 is provided between the intermediate component 66 and the head 80. This inner annular chamber 117 is adjacent to the shaft portion 76 and the second annular seal surface 122, and the supply port 96 at the valve closing position of the intermediate valve body 78 connects the inner annular chamber 117 to the blind bore 92 or to the valve chamber 44 respectively.

[0130] The blind bore 92 penetrates the shaft portion 76 and protrudes inside the head 80. The supply port 96 is formed as a bore inclined with respect to the longitudinal axis L, but in a further embodiment, the supply port 96 can also be configured as a horizontal bore.

[0131] The head 80 is provided with a throttle passage 90 from the end face side of the head 80 facing the control piston 68 to the blind bore 92, which communicates the valve chamber 44 and the control chamber 70. The supply port 96 has a diameter larger than that of the throttle passage 90. Although not shown in this way in the schematic FIG. 3, it is also possible to make the diameter of the supply port 96 larger than the minimum diameter of the stepped outlet bore 102.

[0132] The intermediate valve body 78 in the open valve position allows a second connection between the high-pressure fuel supply port 86 and the valve chamber 44 via the supply port 96, so that fuel can flow into the valve chamber 44 or the blind bore 92 respectively. When the intermediate valve body 78 has already moved slightly away from the intermediate part 66, the fuel from the high-pressure fuel supply port 86 flows from the supply port 96 into the blind bore 92 via the annular gap space 118 and the inner annular chamber 117, and can support the opening operation of the intermediate valve body 78. In the closed valve position of the intermediate valve body 78, the second connection between the high-pressure fuel supply port 86 and the valve chamber 44 or the blind bore 92 is blocked by the second seal bead 112 or the second sealing surface 112.2 respectively.

[0133] The second connection is particularly advantageous for the mushroom-shaped intermediate valve body according to the invention, because the aforementioned rapid fuel supply to the blind bore of the intermediate valve body for the rapid opening operation of the intermediate valve body can be achieved thereby.

[0134] The control piston 68 on the side facing the head 80 preferably has a circular cross-section and functions to define the stroke of the injection valve body 56, and thereby has a cam-shaped protrusion 561 that can support the intermediate valve body 78. The cam-shaped protrusion 561 has a recess 5611 extending perpendicular to the drawing plane, and due to this recess 5611, even when the cam-shaped protrusion 561 supports the intermediate valve body 78, the fuel from the control chamber 70 can flow into the valve chamber 44 or the blind bore 92 via the throttle passage 90 respectively. That is, the recess 5611 is provided to be open towards the control chamber 70 in the radial direction (the direction perpendicular to the drawing shown in FIG. 3).

[0135] The regulating shoulder 84 that defines the opening stroke of the intermediate valve body 78 is provided on the guide sleeve 641 at a distance from the intermediate part 66, and the guide sleeve 641 forms the guide part 64. To enable fuel to flow from the high-pressure fuel supply port 86 to the control chamber 70 with ideally minimal losses, there is a sufficiently large gap in the radial direction between the head 80 and the guide sleeve 641 on the outside. On the head 80 facing the regulating shoulder 84, when the intermediate valve body 78 is in the valve-opening position and the head 80 is seated on the regulating shoulder 84, a wedge-shaped flow groove is provided through which fuel can flow into the control piston 68 from the gap with minimal losses. In a particular embodiment, the guide part 64, or the guide sleeve 641, can be configured integrally with the intermediate part 66 respectively, that is, as a single-piece component.

[0136] In the closed valve position of the intermediate valve 83 at the intermediate valve body 78, the high-pressure fuel supply port 86 is separated from the control chamber 70 and the valve chamber 44, and when the intermediate valve body 78 is in the valve-opening position, that is, when the head 80 is lifted from the intermediate valve seat 82, it functions to allow connection between the high-pressure fuel supply port 86 and the control chamber 70 and the valve chamber 44.

[0137] The intermediate element 98 is arranged on the nozzle body 16, and the planar end face directed away from the intermediate part 66 faces the corresponding end face side of the actuator receiving body 20.

[0138] To accurately position the intermediate element 98 with respect to the actuator receiving body 20, and by extension, with respect to the actuator assembly 38, the intermediate element 98 has opposing positioning bores 106 that are aligned with each other, like blind bores into which a common positioning pin 104 is inserted, similar to the actuator receiving body 20.

[0139] To determine the position of the intermediate part 66 relative to the intermediate element 98, these parts are provided with additional aligned positioning bores, such as blind bores, and similarly, positioning pins 1041 are inserted into the positioning bores. These positioning bores are outside the drawing plane in FIG. 3, and for this reason, the positioning pins 1041 are shown by dashed lines.

[0140] Each component is provided with at least two positioning bores, and the positioning bores are paired with the positioning bores of adjacent parts, and two adjacent parts are configured to be held in a predetermined position relative to each other by at least two positioning pins.

[0141] FIG. 4 shows a longitudinal section of a part of the second embodiment of the fuel injection valve 10 according to the present invention. This part represents the region of the fuel injection valve 10 corresponding to the rectangle indicated by III in FIG. 2, and the specific design form of the region of the second embodiment of the fuel injection valve 10 according to the present invention is different from the fuel injection valve 10' according to International Publication No. WO 2016 / 041739 shown in FIG. 2, particularly in terms of the hydraulic control device 72.

[0142] The second embodiment of the fuel injection valve according to the present invention shown in FIG. 4 substantially corresponds to the first embodiment shown in FIG. 3, and is different in that the first and second toroidal sealing beads 111, 112 are provided not on the head 80 but on the intermediate component 66. The first toroidal seal bead 111 extending at a first radial interval r1 with respect to the guide recess 74 is provided on the side of the intermediate component 66 facing the head 80, and has a first end face 111.1 forming a first seal face 111.2. Further, the second toroidal sealing bead 112 extending at a second radial interval r2 with respect to the guide recess 74 is provided on the side of the intermediate component 66 facing the head 80, and has a second end face 112.1 forming a second seal face 112.2. Furthermore, the first and second end faces 111.1, 112.1 cooperate with the plane of the head 80 facing the first and second seal beads 111, 112 in the closed valve position of the intermediate valve body 78 to form an intermediate valve seat 82 for sealing. That is, the intermediate valve seat 82 is configured to include not only the first end face 111.1 of the first seal bead 111 but also the second end face 112.1 of the second seal bead 112.

[0143] As shown in FIG. 4, the intermediate valve body 78 forms a first annular seal face 121 that is closed by surrounding the head 80, and the side facing the intermediate component 66 across the first seal face 111.2 forms a second annular seal face 122 that is closed by surrounding and seats on the intermediate valve seat 82 across the second seal face 112.2, thereby being positioned in the closed valve position. Here, the first radial interval r1 is larger than the second radial interval r2 from the guide recess 74.

[0144] The features of the high-pressure fuel supply port 86 described with reference to FIG. 3, the sealing effect of the high-pressure fuel supply port 86, and the features related to the gap between the shaft portion 76 and the guide recess 74 can also be analogously applied to the second embodiment shown in FIG. 4. In particular, the high-pressure fuel supply port 86 extending through the intermediate component 66 and communicating with the high-pressure chamber 26 opens into an annular gap space 118 radially defined by first and second annular seal surfaces 121, 122 provided between the intermediate component 66 and the head 80 in the closed valve position of the intermediate valve body 78. As is apparent from FIG. 4, the intermediate component 66 is provided with two high-pressure fuel supply ports 86 that are diametrically opposed and correspond to each other. Further high-pressure fuel supply ports can be provided, for example, on a plane of the intermediate component 66 that is perpendicular to the drawing plane and passes through the longitudinal axis L.

[0145] As is apparent from FIG. 4, the shaft portion 76 has an undercut adjacent to the head 80, and forms an internal annular chamber 108 radially defined by the shaft portion 76 and the intermediate component 66 about the shaft portion 76. The internal annular chamber 108 is adjacent to an internal annular chamber 117, and the internal annular chamber 117 is adjacent to the shaft portion 76 and the second annular seal surface 122. In one embodiment, for example, a further supply port (not shown in FIG. 4) configured as a horizontal bore can be provided in the shaft portion 76, and the further supply port connects a blind bore 92 to the internal annular chamber 108 and is provided as a means for facilitating the opening progression of the intermediate valve body 78.

[0146] In the embodiment shown in FIG. 4, the clearance between the shaft portion 76 and the guide recess 74 functions as a second connection passage that is opened by the intermediate valve body 78 when the high-pressure fuel supply port 86 and the valve chamber 44 are in the valve opening position. As shown in FIG. 4, when the intermediate valve body 78 does not have any supply port as part of the second connection (as in the case of the supply port 96 in FIG. 3), the clearance between the shaft portion 76 and the guide recess 74 is larger than in the embodiment having a supply port, that is, for example, larger than the clearance between the shaft portion and the guide recess 74 in FIG. 3. In the valve closing position of the intermediate valve body 78, the second seal bead 112 or the second annular seal surface 122 blocks the second connection between the high-pressure fuel supply port 86 and the valve chamber 44, respectively.

[0147] It is obvious to those skilled in the art that instead of or in addition to the supply port, the clearance between the shaft portion and the guide recess in FIG. 3 can also function as part of the second connection. In a similar way, instead of or in addition to the clearance between the shaft portion and the guide recess, the supply port in FIG. 4 can also function as part of the second connection.

[0148] When the low-pressure outlet 42 is lifted by the tappet 40 and opened, the compression spring 63 presses the head 80 against the intermediate component 66 and acts to maintain the intermediate valve body 78 in the valve closing position, which is particularly effective at the low system pressure of about 200 to 300 bar during engine idling.

[0149] FIG. 5a is a view showing a part of a third embodiment of the fuel injection valve 10 according to the present invention in a longitudinal section. This part represents the region of the fuel injection valve 10 corresponding to the rectangle shown by III in FIG. 2, and the specific design form of this region of the third embodiment of the fuel injection valve 10 according to the present invention is different from the fuel injection valve 10' according to International Publication No. WO 2016 / 041739 shown in FIG. 2, particularly in terms of the hydraulic control device 72.

[0150] In a manner similar to the embodiment of the fuel injection valve shown in FIG. 3, on the side of the intermediate part 66 facing the head 80 of the intermediate valve body 78, a first seal bead 111 extending around the shaft part 76 at a first radial interval r1 is provided, and has a first end face 111.1 forming a first seal face 111.2.

[0151] However, in contrast to the embodiment of the fuel injection valve shown in FIGS. 3 and 4, the second seal face is formed not by a seal bead but by a step 127 on the side of the head 80 facing the intermediate part 66 in the direction of the longitudinal axis L, and the step 127 extends around the shaft part 76 at a second radial interval r2. The intermediate part 66 on the side facing the head 80 also has a step 125 surrounding the guide recess 74, and the offset edges 125.1 and 127.1 of the steps 125 and 127 in the closed valve position of the illustrated intermediate valve body 78 radially demarcate the second annular seal face 122.

[0152] The step 127 of the head 80 is formed by an undercut that simultaneously forms an annular gap space 118 in which the high-pressure fuel supply port 86 opens. The step 127 has a horizontal plane forming a second seal face 112.2, and in the closed valve position of the intermediate valve body 78, forms a second annular seal face 122 that is substantially closed by surrounding, and seals tightly against the face 781 of the intermediate part 66 facing the head 80 in the direction of the longitudinal axis L. The face 781 of the intermediate part 66 facing the head 80 in the direction of the longitudinal axis L forms a first annular seal face 121 that is substantially closed by surrounding and forms an intermediate valve seat 82 that seals the first seal face 111.2 of the first seal bead 111 in the closed valve position of the intermediate valve body 78.

[0153] The step 125 of the intermediate part 66 is formed by an annular recess 126 having a rectangular cross-sectional profile in the surrounding direction. In a further variant, the annular recess 126 in the surrounding direction can have a chamfered cross-sectional profile or a curved cross-sectional profile. The annular recess 126 forms an inner annular chamber defined by the intermediate part 66, the shaft part 76, and the head 80 in the closed valve position of the intermediate valve body 78.

[0154] Furthermore, in FIG. 5a, it can be seen that the outlet bore 102 extends within the intermediate component 66. The intermediate component 66 is received in the receiving recess 151 in the manner of the blind bore of the intermediate body 15, and the latter functions as the actuator receiving body 20 of the actuator assembly 38. In contrast to the embodiments of FIGS. 3 and 4, no separate intermediate component and no separate intermediate element are provided, and these two components are integrally formed as a single-piece intermediate component 66. The outlet bore 102 has an inclined bore portion connected to the low-pressure outlet 42 disposed eccentrically with respect to the guide recess 74 in the manner of the blind bore of the intermediate component 66.

[0155] Not only the shaft portion 76 but also the head portion 80 can be received in the guide recess 74 in the manner of the blind bore of the intermediate component 66. The guide recess 74 in the region facing the control piston 68 extends into a head space 128 capable of receiving the head portion 80. The end side 84 of the adjacent guide sleeve 641 facing the intermediate component 66 functions as a regulating shoulder for receiving the head portion 80 at the valve opening position of the intermediate valve body 78.

[0156] As shown in FIG. 3 or FIG. 4, instead of the single-piece intermediate component 66, a separate intermediate element and a separate intermediate component can be provided. Also, the intermediate component and the guide sleeve can be integrally formed. Furthermore, the intermediate element and the intermediate component shown in FIG. 3 or FIG. 4 can be integrally formed.

[0157] The shaft portion 76 includes two annular protrusions 761 and 762 that are arranged at intervals in the direction of the longitudinal axis L of the shaft portion 76 and surround the shaft portion 76 (partially shown by broken lines in Fig. 5a), whereby the shaft portion 76 is guided within the guide recess 74. Two throttle passages that are arranged in series along the longitudinal axis L and surround the shaft portion 76 in the longitudinal axis L are constituted by the annular protrusions 761 and 762. As a result, the formation and generation of turbulent flow of the fluid flowing through the intermediate space between the shaft portion 76 and the guide recess 74 are promoted. There is a clearance of at least 50 μm in the radial direction between the shaft portion 76 and the guide recess 74. In a further embodiment, the clearance can be a value between 70 μm and 100 μm in each case. Due to the radial clearance, the radial range of the second annular seal surface 122 varies according to the radial current position of the shaft portion 76 within the guide recess 74. In order to ensure the sealing function of the intermediate valve, the maximum radial spread of the second annular seal surface 122 here is larger than the clearance.

[0158] In the embodiment shown in Fig. 5a, the clearance between the shaft portion 76 and the guide recess 74 functions as a second connection passage through which the high-pressure fuel supply port 86 and the valve chamber 44 are opened by the intermediate valve body 78 in the valve opening position. In the valve closing position of the intermediate valve body 78, the second annular seal surface 122 blocks the second connection between the high-pressure fuel supply port 86 and the valve chamber 44.

[0159] Figure 5b is a partial cross-sectional explanatory view of a further embodiment of the fuel injection valve according to the present invention, and this embodiment of the fuel injection valve is embodied by corresponding to the embodiment shown in Figure 5a. Here, the cross-section shown in Figure 5b is the A-A cross-section in Figure 5a. That is, Figure 5b shows an example of the embodiment of the fuel injection valve shown in Figure 5a. As shown in Figure 5b, the second annular protrusion 762 in the surrounding direction has three chamfers 762.1, 762.2, 762.3, whereby the intermediate space 119 (or three intermediate spaces corresponding to each other) is formed between the shaft portion 76 or the annular protrusion 762 and the guide recess 74, respectively. Although not shown in Figure 5b, the first annular protrusion 761 in the surrounding direction also has corresponding chamfers. By providing the chamfers 762.1-3 on the second annular protrusion 762 (and by providing chamfers on the first annular protrusion), a passage composed of the intermediate space 119 between the chamfer and the guide recess 74 is formed, and this passage functions as a passage for the second connection. Further, by the chamfers 762.1-3 (and the chamfers of the first annular protrusion) and the passage for the second connection formed thereby, the clearance between the shaft portion 76 and the guide recess 74 can be made smaller than in the embodiment described with reference to Figure 5a, which leads to an improvement in the centering of the shaft portion. The three chamfer portions 762.1-3 (and the chamfer portions of the first annular protrusion) are arranged at an angle of 120° to each other. However, other arrangements are also conceivable, and in each case, an embodiment having one chamfer per annular protrusion, or an embodiment having two chamfers per annular protrusion, or an embodiment having more chamfers is particularly conceivable.

[0160] Furthermore, in a specific embodiment of the embodiment of the fuel injection valve shown in, for example, Figure 3 or 4, that is, a shaft portion without an annular protrusion, in the circumferential direction, it can also have at least one chamfer, or two or three chamfers. In this case, the second connection path can be formed again by the chamfer or the intermediate space between the chamfer and the guide recess.

[0161] FIG. 6 shows a longitudinal section of a part of a fourth embodiment of the fuel injection valve 10 according to the present invention. This part represents the region of the fuel injection valve 10 corresponding to the rectangle indicated by III in FIG. 2, and the specific design form of this region of the fuel injection valve 10 according to the present invention is different from the fuel injection valve 10' according to International Publication No. 2016 / 041739 shown in FIG. 2, particularly in terms of the hydraulic control device 72.

[0162] The intermediate valve body 78 has a valve chamber passage 441 communicating with the valve chamber 44, and is composed of a bore 441.1 parallel to the longitudinal axis L and a horizontal bore 441.2. The valve chamber passage 441 provides a blind bore 92 of the intermediate valve body 78 communicating with the valve chamber 44 between the intermediate component 66 and the head 80 at the closed valve position of the illustrated intermediate valve body 78, and communicates with an annular gap space 118 radially partitioned by the first and second annular seal surfaces 121, 122. The bore 441.1 parallel to the longitudinal axis L opens into the annular gap space 118 via the first end and into the horizontal bore 441.2 via the second end. The horizontal bore 441.2 opens into the blind bore 92 in sequence via the first end. As shown in FIG. 5a, the second end of the horizontal bore 441.2 is blocked by a stopper 441.3. In a modification, the intermediate valve body 78 or the head 80 each has a further valve chamber passage 441 shown by a dashed line in FIG. 5a. Since the horizontal bore 441.2 of the further valve chamber passage 441 shown by the dashed line is bored together with the latter horizontal bore 441.2 shown on the left side by a solid line, it is not blocked individually by the stopper. <000>

[0163] At the open valve position of the intermediate valve body 78, the bore 441.1 opens the second connection between the high-pressure fuel supply port 86 and the blind bore 92 or the valve chamber 44 respectively, allowing the blind bore 92 or the valve chamber 44 to be flooded with fuel respectively. At the closed valve position of the intermediate valve body 78, the second annular seal surface 122 blocks the second connection between the high-pressure fuel supply port 86 and the valve chamber 44.

[0164] In contrast to the embodiments shown in FIGS. 3 to 5, the high-pressure fuel supply port 86 according to the embodiment shown in FIG. 6 opens into an annular chamber 120 defined by an intermediate component 66, a shaft portion 76, and a head portion 80 in the closed valve position of the intermediate valve body 78. In the closed valve position of the intermediate valve body 78, the annular chamber 120 is adjacent to a second annular seal surface 122 and is provided in a radial direction closer to the shaft portion 76 than the second annular seal surface 122.

[0165] The annular chamber 120 extending around the shaft portion 76 has an internal annular chamber 108 defined between the shaft portion 76 and the intermediate component 66, and the internal annular chamber 108 is recessed in the shaft portion 76 itself. The high-pressure fuel supply port 86 opens into the internal annular chamber 108. The annular chamber 120 further has an annular gap space 117 adjacent to the internal annular chamber 108, and the annular gap space 117 is formed in an enclosed gap between the intermediate component 66 and the head portion 80 in the closed valve position of the intermediate valve body 78 and is radially adjacent to the second annular seal surface 122. The internal annular chamber 108 is formed by an enclosed annular groove having a trapezoidal cross-section that opens outward in the radial direction and has an obliquely extending side facing away from the head portion 80.

[0166] The shaft portion 76 is slidably guided by a fitting of approximately 3 μm to 10 μm in the guide recess 74. The diameter of the longitudinal bore 441.1 of the valve chamber passage 441 is larger than the diameter of the throttle passage 90, and when the intermediate valve body 78 moves away from the closed valve position, fuel can flow quickly into the blind bore 92 and the valve chamber 44.

[0167] In a modified example, as shown by the dashed line in FIG. 6, a second side passage 97 is provided in the intermediate component 66. The second passage 97 communicates the high-pressure chamber 26 and the valve chamber 44 and facilitates the opening operation of the intermediate valve body 78 when the tappet 40 closes the low-pressure outlet 42 and disconnects the valve chamber 44 from the low-pressure fuel return port 46.

[0168] FIG. 7 is a longitudinal sectional view showing a part of a fifth embodiment of the fuel injection valve 10 according to the present invention. This part represents the region of the fuel injection valve 10 corresponding to the rectangle indicated by III in FIG. 2, and the specific design form of this region of the fuel injection valve 10 according to the present invention is different from the fuel injection valve 10' according to International Publication No. 2016 / 041739 shown in FIG. 2, particularly in terms of the hydraulic control device 72.

[0169] Compared with the fourth embodiment shown in FIG. 6, the valve chamber passage 441 has a bore 441.1 inclined with respect to the longitudinal axis L. Due to the inclined bore 441.1, the first seal bead 111 can be provided at a position radially away from the shaft portion 76 without reducing the stopper 441.3 compared with the fourth embodiment shown in FIG. 6. The valve chamber passage 441 communicates with the annular gap space 118 defined by the head 80, the intermediate part 66, and the first and second annular seal surfaces 121, 122 through the inclined bore 441.1. Similar to the fourth embodiment shown in FIG. 6, one end of the horizontal bore 441.2 opens into the blind bore 92.

[0170] Compared with the fourth embodiment shown in FIG. 6, the inner annular chamber 108 of the annular chamber 120 is further defined by a recess provided in the shaft portion 76 and a recess provided in the intermediate part 66. The inner annular chamber 108 is provided adjacent to the annular gap space 117, and the annular gap space 117 is formed by the surrounding gap between the intermediate part 66 and the head 80 in the closed valve position of the intermediate valve body 78 and is adjacent to the second annular seal surface 122 in the radial direction.

[0171] The second passage 97 consists of a linear horizontal bore provided in the shaft portion 76, and any second passage 97 connecting the high-pressure chamber 26 or the high-pressure fuel supply port 86 to the blind bore 92 through the annular chamber 120 is shown by a dashed line.

[0172] Compared with the fourth embodiment shown in FIG. 6, the first and second seal beads 111, 112 are formed longer in the direction of the longitudinal axis L such that the annular gap space 118 becomes deeper by the longitudinal axis L.

[0173] Furthermore, the intermediate part 66 is configured as a single part in which an outlet bore 102 consisting of an inclined bore extends, in the same manner as the embodiment shown in FIG. 5a. However, instead of a single intermediate part 66, another intermediate element and another intermediate part as shown in FIG. 6 can also be provided. It is also possible to integrally configure the intermediate element and the intermediate part shown in FIG. 6.

[0174] In the same manner as the embodiment shown in FIG. 6, a further valve chamber passage can be provided, and the valve chamber passage is indicated by a dashed line in the right region of the head 80.

[0175] The shaft portion 76 is slidably guided in the guide recess 74 by an interference fit of about 3 μm to 10 μm. The diameter of the inclined hole 441.1 of the valve chamber passage 441 is larger than the diameter of the throttle passage 90, and when the intermediate valve body 78 is lifted from the closed position, fuel can flow quickly into the blind bore 92 and the valve chamber 44.

[0176] In the open position of the intermediate valve body 78, the second connection between the high-pressure fuel supply port 86 and the blind bore 92, or the valve chamber 44, is opened by the bore 441.1, respectively, and fuel is supplied to the blind bore 92, or the valve chamber 44. In the closed position of the intermediate valve body 78, the second annular seal surface 122 blocks the second connection between the high-pressure fuel supply port 86 and the valve chamber 44.

[0177] Proceeding from the closed valve position of the intermediate valve 83 shown in the figure, in order to inject fuel, when the tappet 40 is lifted from the intermediate element 98 or the intermediate part 66 by the solenoid of the actuator assembly 38, the low-pressure outlet 42 is opened. This results in a greater amount of fuel flowing from the valve chamber 44 to the low-pressure fuel return port 46 per unit time than the fuel that can be replenished by the flow from the throttle passage 90 and the potentially provided second passage 97 to the valve chamber 44. As a result, the pressure in the valve chamber 44 decreases, and due to the compression difference resulting from the pressure drop, the intermediate valve body 78 is pressed against the intermediate part 66. On the one hand, the intermediate valve 83 is reliably held in the closed state, and on the other hand, the pressure in the control chamber 70 decreases. As a result, the injection valve body 56 is lifted from the injection valve seat 18' by the action of the double-acting control piston 68 against the force of the compression spring 62', thereby starting the injection of fuel into the combustion chamber of the internal combustion engine.

[0178] When terminating this injection, the low-pressure outlet 42 is blocked by seating the tappet 40 on the intermediate element 98 or the intermediate part 66. As a result, the fuel flowing in through the throttle passage 90 and the potentially provided second passage 97 raises the pressure in the valve chamber 44, causing the intermediate valve body 78 to move away from the intermediate valve seat 82. This movement is further promoted simultaneously with the minimum opening operation of the intermediate valve body 78, and as a result, the opened annular cross-section quickly becomes substantially larger than the cross-section of the supply port 96, and fuel is supplied to the inner annular chamber 117 in the embodiment shown in FIG. 3, for example. In an embodiment where the high-pressure fuel supply port 86 opens into the annular gap space 118, the opening operation of the intermediate valve body 78 is promoted by the high system pressure in the annular gap space 118. When there is a larger clearance between the shaft portion 76 and the guide recess 74, fuel flows into the valve chamber 44 while the intermediate valve body 78 is opening, and this fuel can quickly fill the valve chamber 44 while the sealing action by the annular seal surfaces 121, 122 is released.

[0179] In an embodiment where the valve chamber passage 441 opens into the annular gap space 118, when the head 80 is lifted from the closed valve position of the intermediate valve 78, the valve chamber 44 can be quickly filled with fuel flowing into the valve chamber passage 441, and the opening operation of the intermediate valve body 78 can be smoothed.

[0180] When the head 80 of the intermediate valve body 78 is lifted from the intermediate component 66, the large flow path cross-section from the high-pressure fuel supply port 86 to the control chamber 70 is similarly quickly opened, whereby the injection valve body 56 quickly moves toward the injection valve seat 18, leading to a quick end of the injection operation where the injection valve body 56 hits the injection valve seat 18.

Description of Reference Numerals

[0181] 10 Fuel injection valve, 44 Valve chamber, 56 Injection valve body, 66 Intermediate component, 72 Hydraulic control device, 74 Guide recess, 76 Shaft portion, 78 Intermediate valve body, 82 Intermediate valve seat, 83 Intermediate valve, 86 High-pressure fuel inlet, 118, 117, 96 Second connection, 111.2 First seal surface, 112.2 Second seal surface, 121 First annular seal surface, 122 Second annular seal surface

Claims

1. A fuel injection valve (10) for intermittently injecting fuel into a combustion chamber of an internal combustion engine, a housing (12') defining a longitudinal axis (L) and having a high-pressure fuel inlet (24') and an injection valve seat (18'); a high-pressure chamber (26) provided within the housing (12') and extending from the high-pressure fuel inlet (24') to the injection valve seat (18'); an injection valve body (56) provided within the housing (12') so as to be adjustable in the direction of the longitudinal axis (L) and cooperating with the injection valve seat (18'); a compression spring (62') for biasing the injection valve body (56) by a closing force directed towards the injection valve seat (18'); a guide portion (64) for slidably guiding a control piston (68) of the injection valve body (56); an intermediate component (66) partitioning a control chamber (70) together with the guide portion (64) and the control piston (68); a hydraulic control device (72) including an intermediate valve body (78) having a shaft portion (76) and a head portion (80) formed in a mushroom shape and guided by a guide recess (74) of the intermediate component (66), and an intermediate valve seat (82) provided on a side facing the head portion (80) of the intermediate component (66) and cooperating with the head portion (80). The intermediate valve body (78) opens a first connection between a high-pressure fuel supply port (86) connected to the high-pressure chamber (26) and the control chamber (70) in an open valve position, and shuts off the first connection between the high-pressure fuel supply port (86) and the control chamber (70) in a closed valve position. The hydraulic control device (72) controls the axial movement of the injection valve body (56) by adjusting the pressure within the control chamber (70) to disconnect the control chamber (70) from the valve chamber (44) except for a throttle passage (90); an electrically operable actuator assembly (38) for connecting the valve chamber (44) to a low-pressure fuel return port (46) and disconnecting the valve chamber (44) from the low-pressure fuel return port (46); comprising the intermediate valve body (78) opens a second connection (comprising 『118, 117, 96, 74, 126, 119, 108, 441, 441.1, 441.2』) between the high-pressure fuel supply port (86) and the valve chamber (44) in an open valve position, and shuts off the second connection (comprising 『118, 117, 96, 74, 126, 119, 108, 441, 441.1, 441.2』) between the high-pressure fuel supply port (86) and the valve chamber (44) in a closed valve position. The second connection (118, 117, 96) forms a supply port (96) of the intermediate valve body whose first end opens into the valve chamber (44) and whose second end opens towards the outside of the intermediate valve body (78). In the closed position of the intermediate valve body (78), the side of the head (80) facing the intermediate part (66) crosses a first sealing surface (111.2) extending at a first radial distance (r1) from the shaft part (76) or the guide recess (74), and at the same time forms a substantially closed first annular sealing surface (121) in the circumferential direction, and crosses a second sealing surface (112.2) extending at a second radial distance (r2) from the shaft part (76) or the guide recess (74), and at the same time forms a second annular sealing surface (122) substantially closed in the circumferential direction, and is pressed against the intermediate valve seat (82). The first radial distance (r1) is greater than the second radial distance (r2). In the closed position of the intermediate valve body (78), an inner annular chamber (117, 126) adjacent to the shaft part (76) and the second annular sealing surface (122) is formed between the intermediate part (66) and the head (80). The supply port (96) in the closed position of the intermediate valve body (78) connects the inner annular chamber (117, 126) and the valve chamber (44). The fuel injection valve (10) is characterized by this.

2. The fuel injection valve (10) according to claim 1, The second connection (118, 117, 96, 108, 441, 441.2) passes between the high-pressure fuel supply port (86) and a bore (92) forming a part of the valve chamber (44) and penetrates the shaft part (76) of the intermediate valve body (78). The fuel injection valve (10) is characterized by this.

3. The fuel injection valve (10) according to claim 1 or 2, The first annular sealing bead (111) having a first end face (111.1) forming the first sealing surface (111.2) is provided on the side of the head (80) facing the intermediate part (66) or on the side of the intermediate part (66) facing the head (80). The fuel injection valve (10) is characterized by this.

4. The fuel injection valve (10) according to any one of claims 1 to 3, The second annular sealing bead (112) having a second end face (112.1) forming the second sealing surface (112.2) is provided on the side of the head (80) facing the intermediate part (66) or on the side of the intermediate part (66) facing the head (80). The fuel injection valve (10) is characterized by this.

5. The fuel injection valve (10) according to any one of claims 1 or 2, The intermediate component (66) on the side facing the head (80) has at least one stepped portion (125), the head (80) on the side facing the intermediate component (66) has at least one stepped portion (127), and at the closed valve position of the intermediate valve body (78), the mutually offset edges (125.1, 127.1) of the stepped portions (125, 127) of the intermediate component (66) and the head (80) radially delimit the first and / or second annular seal surfaces (121, 122). A fuel injection valve (10) is characterized in that.

6. The fuel injection valve (10) according to claim 5, wherein The stepped portion (125) of the intermediate component (66) forms an inner annular chamber (126) delimited by the intermediate component (66), the shaft portion (76), and the head (80) at the closed valve position of the intermediate valve body (78). A fuel injection valve (10) is characterized in that.

7. The fuel injection valve (10) according to any one of claims 1 to 6, wherein The high-pressure fuel supply port (86) of the intermediate component (66) is provided between the intermediate component (66) and the head (80) at the closed valve position of the intermediate valve body (78), and extends to open into an annular gap space (118) radially delimited by the first and second annular seal surfaces (121, 122). A fuel injection valve (10) is characterized in that.

8. The fuel injection valve (10) according to claim 7, wherein The supply port (96) by the second end portion is provided at a position where the second end portion is closer to the shaft portion (76) in the radial direction than the second annular seal surface (122) at the closed valve position of the intermediate valve body (78), and opens toward the outside of the intermediate valve body (78). A fuel injection valve (10) is characterized in that.

9. The fuel injection valve (10) according to any one of claims 1 to 8, wherein The second connection (118, 117, 74, 126) includes a passage formed by a radial clearance between the shaft portion (76) and the guide recess (74), and the clearance is 10 μm to 50 μm. A fuel injection valve (10) is characterized in that.

10. The fuel injection valve (10) according to any one of claims 1 to 9, wherein The shaft portion (76) has two annular protrusions (761, 762) provided at intervals in the longitudinal direction of the shaft portion (76). A fuel injection valve (10) is characterized in that.

11. The fuel injection valve (10) according to claim 10, wherein The circumferential annular protrusions (761, 762) each have at least one chamfer (762.1, 762.2, 762.3), and the second connection (118, 117, 126, 74) is characterized in that it comprises a passage formed by an intermediate space (119) between at least one chamfer (762.1, 762.2, 762.3) and the guide recess (74). A fuel injection valve (10).

12. The fuel injection valve (10) according to claim 11, wherein The circumferential annular protrusions (761, 762) each have two or three chamfered portions (762.1, 762.2, 762.3). A fuel injection valve (10).

13. The fuel injection valve (10) according to any one of claims 1 to 12, wherein The circumferential shaft portion (76) has at least one chamfer, and the second connection is characterized in that it comprises a passage formed by an intermediate space between at least one chamfer and the guide recess (74). A fuel injection valve (10).

14. The fuel injection valve (10) according to any one of claims 1 to 6, wherein The second connection (118, 108, 441, 441.1, 441.2) includes a bore (441, 441.1, 441.2) that penetrates the head (80) of the intermediate valve body (78) and forms a valve chamber passage (441, 441.1, 441.2). The bore (441, 441.1, 441.2) is configured separately from the bore (92), communicates with the valve chamber (44), and has one end opening on the side facing the intermediate component (66) of the head (80). A fuel injection valve (10).

15. The fuel injection valve (10) according to any one of claims 1 to 7 and claim 14, wherein The valve chamber passages (441, 441.1, 441.2) of the intermediate valve body (78) are provided between the intermediate component (66) and the head (80) in the closed valve position of the intermediate valve body (78), and are radially defined by the first and second annular seal surfaces (121, 122). A fuel injection valve (10) characterized by extending to open into the annular gap space (118).

16. The fuel injection valve (10) according to claim 14 or 15, wherein The fuel injection valve has an annular chamber (120) defined by an intermediate component (66), a shaft portion (76), and a head (80) in the closed valve position of the intermediate valve body (78), adjacent to the second annular seal surface (122), and into which a high-pressure fuel supply port (86) opens. A fuel injection valve (10).

17. A fuel injection valve (10) for intermittently injecting fuel into a combustion chamber of an internal combustion engine, a housing (12') defining a longitudinal axis (L) and having a high-pressure fuel inlet (24') and an injection valve seat (18'); a high-pressure chamber (26) provided within the housing (12') and extending from the high-pressure fuel inlet (24') to the injection valve seat (18'); an injection valve body (56) provided within the housing (12') so as to be adjustable in the direction of the longitudinal axis (L) and cooperating with the injection valve seat (18'); a compression spring (62') for biasing the injection valve body (56) by a closing force directed toward the injection valve seat (18'); a guide portion (64) slidably guiding a control piston (68) of the injection valve body (56); an intermediate component (66) partitioning a control chamber (70) together with the guide portion (64) and the control piston (68); a hydraulic control device (72) for controlling the axial movement of the injection valve body (56) by adjusting the pressure within the control chamber (70), the hydraulic control device (72) including an intermediate valve body (78) having a shaft portion (76) and a head portion (80) formed in a mushroom shape and guided by a guide recess (74) of the intermediate component (66), and an intermediate valve (83) including an intermediate valve seat (82) provided on a side facing the head portion (80) of the intermediate component (66) and cooperating with the head portion (80), wherein the intermediate valve body (78) opens a first connection between a high-pressure fuel supply port (86) connected to the high-pressure chamber (26) and the control chamber (70) in an open valve position, shuts off the first connection between the high-pressure fuel supply port (86) and the control chamber (70) in a closed valve position, and disconnects the control chamber (70) from a valve chamber (44) except for a throttle passage (90). The head (80), in the valve closing position of the intermediate valve body (78), extends with a first radial interval (r1) with respect to the shaft portion (76) or the guide recess (74) across the first sealing surface (111.2) by the opposing surface with the intermediate component (66), and at the same time forms a first annular sealing surface (121) closed in the circumferential direction, and extends with a second radial interval (r2) with respect to the shaft portion (76) or the guide recess (74) across the second sealing surface (112.2), and at the same time forms a second annular sealing surface (122) closed in the circumferential direction, is pressed against the intermediate valve seat (82), the first radial interval (r1) is larger than the second radial interval (r2), connects the valve chamber (44) to the low-pressure fuel return port (46), and an electrically operable actuator assembly (38) for disconnecting the valve chamber (44) from the low-pressure fuel return port (46), comprising, The intermediate valve body (78) has a valve chamber passage (441) communicating with the valve chamber (44). In the valve closing position of the intermediate valve body (78), the valve chamber passage (441) is provided between the intermediate component (66) and the head (80) and extends to communicate with an annular gap space (118) radially partitioned by the first and second annular sealing surfaces (121, 122). The fuel injection valve is characterized in that, in the valve closing position of the intermediate valve body (78), it has an annular chamber (120) defined by the intermediate component (66), the shaft portion (76), and the head (80), adjacent to the second annular sealing surface (122), and in which the high-pressure fuel supply port (86) opens.

18. The fuel injection valve (10) according to claim 17, The valve chamber passage (441) in the head (80) is parallel to the longitudinal axis (L) or inclined with respect to the longitudinal axis (L), and in the valve closing position of the intermediate valve body (78), has a bore (441.1) opening into the annular gap space (118). The fuel injection valve (10) is characterized by this.

19. A fuel injection valve (10) for intermittently injecting fuel into the combustion chamber of an internal combustion engine, a housing (12') defining a longitudinal axis (L) and having a high-pressure fuel inlet (24') and an injection valve seat (18'), a high-pressure chamber (26) provided in the housing (12') and extending from the high-pressure fuel inlet (24') to the injection valve seat (18'), an injection valve body (56) provided in the housing (12') so as to be adjustable in the direction of the longitudinal axis (L) and cooperating with the injection valve seat (18'), A compression spring (62') that biases the injection valve body (56) by a closing force directed toward the injection valve seat (18'), a guide portion (64) that slidably guides the control piston (68) of the injection valve body (56), an intermediate component (66) that partitions the control chamber (70) together with the guide portion (64) and the control piston (68), a hydraulic control device (72) that includes an intermediate valve body (78) formed in a mushroom shape and having a shaft portion (76) and a head portion (80) guided by a guide recess (74) of the intermediate component (66), and an intermediate valve seat (82) provided on a side facing the head portion (80) of the intermediate component (66) and cooperating with the head portion (80). The intermediate valve body (78) opens a first connection between a high-pressure fuel supply port (86) connected to the high-pressure chamber (26) and the control chamber (70) at the valve opening position, and shuts off the first connection between the high-pressure fuel supply port (86) and the control chamber (70) at the valve closing position, and cuts off the control chamber (70) from the valve chamber (44) except for the throttle passage (90), and controls the axial movement of the injection valve body (56) by adjusting the pressure in the control chamber (70), The head portion (80) extends at a first radial interval (r1) with respect to the shaft portion (76) or the guide recess (74) across the first seal surface (111.2) by the opposing surface with the intermediate component (66) at the valve closing position of the intermediate valve body (78), and simultaneously forms a first annular seal surface (121) closed in the circumferential direction, and extends at a second radial interval (r2) with respect to the shaft portion (76) or the guide recess (74) across the second seal surface (112.2), and simultaneously forms a second annular seal surface (122) closed in the circumferential direction, and is pressed against the intermediate valve seat (82). The first radial interval (r1) is larger than the second radial interval (r2). An electrically operable actuator assembly (38) for connecting the valve chamber (44) to the low-pressure fuel return port (46) and disconnecting the valve chamber (44) from the low-pressure fuel return port (46), is provided with, The high-pressure fuel supply port (86) of the intermediate component (66) is provided between the intermediate component (66) and the head portion (80) at the valve closing position of the intermediate valve body (78), and extends to open into an annular gap space (118) radially partitioned by the first and second annular seal surfaces (121, 122), The shaft portion (76) has at least one surrounding annular protrusion (761), and the shaft portion (76) is characterized in that at least one surrounding annular protrusion (761) is guided by the guide recess (74) in a fuel injection valve (10).

20. The fuel injection valve (10) according to claim 19, wherein the shaft portion (76) is slidably guided by a guide recess (74) of an intermediate component (66), and a clearance of 10 μm to 50 μm in the radial direction is provided between the shaft portion (76) and the guide recess (74), in a fuel injection valve (10).

21. The fuel injection valve (10) according to claim 19 or 20, wherein the intermediate valve body (78) is provided such that, in the valve closing position of the intermediate valve body (78), the second end portion is arranged at a position closer to the shaft portion (76) in the radial direction than the second annular seal surface (122), and has a supply port (96) whose first end portion opens into the valve chamber (44) and whose second end portion opens toward the outside of the intermediate valve body (78), in a fuel injection valve (10).

22. The fuel injection valve (10) according to any one of claims 19 to 21, wherein the shaft portion (76) has two annular protrusions (761, 762) arranged at intervals in the longitudinal direction of the shaft portion (76), in a fuel injection valve (10).

23. The fuel injection valve (10) according to claim 22, wherein the shaft portion (76) is guided by a guide recess (74) of an intermediate component (66) such that a clearance between 50 μm and 100 μm in the radial direction is provided between the shaft portion (76) and the guide recess (74), in a fuel injection valve (10).

24. The fuel injection valve (10) according to any one of claims 17 to 23, wherein the first annular seal bead (111) has a first end face (111.1) forming a first seal surface (111.2), and is provided on a side of the intermediate component (66) facing the head portion (80) or on a side of the head portion (80) of the intermediate component (66) facing the intermediate component (66), in a fuel injection valve (10).

25. The fuel injection valve (10) according to any one of claims 17 to 24, wherein the second annular seal bead (112) has a second end face (112.1) forming a second seal surface (112.2), and is provided on a side of the intermediate component (66) facing the head portion (80) or on a side of the head portion (80) of the intermediate component (66) facing the intermediate component (66), in a fuel injection valve (10).

26. A fuel injection valve (10) according to any one of claims 17 to 25, wherein an intermediate component (66) on a side facing a head (80) has at least one stepped portion (125), the head (80) on a side facing the intermediate component (66) has at least one stepped portion (127), and in a valve closing position of an intermediate valve body (78), mutually offset edges (125.1, 127.1) of the stepped portions (125, 127) of the intermediate component (66) and the head (80) radially delimit first and / or second annular seal surfaces (121, 122), respectively, the fuel injection valve (10) being characterized thereby.

27. A fuel injection valve (10) according to claim 26, wherein the stepped portion (125) of the intermediate component (66) forms an inner annular chamber (126) delimited by the intermediate component (66), a shaft portion (76), and the head (80) in a valve closing position of the intermediate valve body (78), the fuel injection valve (10) being characterized thereby.

28. A fuel injection valve (10) according to any one of claims 17 to 23, wherein the shaft portion (76) is constantly guided by a guide recess (74) of the intermediate component (66), the fuel injection valve (10) being characterized thereby.

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