GAS INJECTION VALVE FOR INJECTING A COMBUSTIBLE GAS INTO AN INTERNAL COMBUSTION ENGINE, INTERNAL COMBUSTION ENGINE HAVING SUCH A GAS INJECTION VALVE, AND METHOD FOR OPERATING SUCH AN INTERNAL COMBUSTION ENGINE

Abstract

A gas injection valve for injecting a combustible gas into an internal combustion engine, comprising a valve element, which can be moved between closed position and an open position, the open position being defined by a maximum stroke of the valve element. The maximum stroke of the valve element can be adjusted during operation of the gas injection valve.

Claims

1-10. (canceled)

11. A gas injection valve for injecting a combustion gas into an internal combustion engine, comprising: a valve member displaceable between a closed position and an open position defined by a maximum stroke of the valve member, wherein the maximum stroke of the valve member is adjustable during operation of the gas injection valve.

12. The gas injection valve according to claim 11, further comprising a housing and a first stop, against which the valve member, in the open position, butts, wherein the first stop defines the maximum stroke, and wherein the first stop is displaceable, viewed in a stroke direction of the valve member, relative to the housing.

13. The gas injection valve according to claim 12, further comprising a stop member, wherein the first stop is disposed on the stop member, wherein the stop member is displaceable between a second stop, arranged in a spatially fixed manner relative to the housing, and a third stop, arranged in a spatially fixed manner relative to the housing, wherein the second stop defines a minimum position for the first stop, and the third stop defines a maximum position for the first stop.

14. The gas injection valve according to claim 13, further comprising a first displacement mechanism for displacement of the valve member between the closed position and the open position, and a second displacement mechanism for displacement of the first stop.

15. The gas injection valve according to claim 14, wherein the second displacement mechanism includes an actuatable rotary drive that cooperates with a thread for adjustment of the first stop.

16. The gas injection valve according to claim 15, further comprising an adjusting element that is displaceable jointly with the stop member and has a first thread that meshes with a second thread arranged in a spatially fixed manner relative to the housing, wherein the rotary drive is configured and arranged to rotationally drive the adjusting element.

17. An internal combustion engine, comprising a gas injection valve according to claim 11.

18. A method for operating an internal combustion engine having a gas injection valve according to claim 11, comprising the steps of: setting a combustion gas quantity to be injected on an operating-point-dependent basis by adjusting a maximum stroke of a valve member of the gas injection valve; and, choosing actuation times for the gas injection valve on an operating-point-dependent basis for an optimized mixture formation in at least one combustion chamber of the Internal combustion engine.

19. The method according to claim 18, including setting a constant combustion gas pressure, upstream of the gas injection valve, in a combustion gas supply line of the internal combustion engine.

20. The method according to claim 18, including operating the internal combustion engine with a plurality of combustion chambers, and assigning a gas injection valve to each combustion chamber or to each combustion chamber assembly of a plurality of combustion chamber assemblies of the internal combustion engine, wherein actuation times and/or maximum stroke is/are set separately for each gas injection valve.

Description

[0026] The invention is explained in greater detail below on the basis of the drawing. The single FIGURE here shows a schematic representation of an illustrative embodiment of an internal combustion engine having a gas injection valve.

[0027] The single FIGURE shows a schematic representation of an illustrative embodiment of an internal combustion engine 1 having a gas injection valve 3. The gas injection valve 3 is designed to inject a combustion gas into the internal combustion engine 1. It has a valve member 5, which is displaceable between a closed position, in which a flow path for combustion gas is closed by the gas injection valve 3, and an open position, defined by a maximum stroke of the valve member 5, in which a flow path for combustion gas is opened up by the gas injection valve 3. It is here provided that the maximum stroke of the valve member 5 is adjustable during operation of the gas injection valve 3. In this way, the adjustment of the maximum stroke of the valve member 5 can be used as a parameter for the quantity control of a combustion gas quantity to be injected into the internal combustion engine 1. This enables, in particular, a choice of energization or actuation times for the gas injection valve 3 independently of the combustion gas quantity to be injected, so that this can rather be chosen such that it is in particular optimized to a mixture formation into a combustion chamber 7 of the internal combustion engine 1. Moreover, a complicated regulation of a primary pressure for the combustion gas can be dispensed with, rather it is possible, upstream of the gas injection valve 3, to set a constant combustion gas pressure which is, in particular, independent of the operating point, since this is no longer required as a parameter for the quantity control. Furthermore, ageing effects of a charging path 9 of the internal combustion engine 1 and/or of the gas injection valve 3 can be offset by variation of the maximum stroke.

[0028] The gas injection valve 3 has a first stop 11, against which the valve member 5, in the open position, butts. The first stop 11 here defines the maximum stroke, wherein it is displaceable, viewed in the stroke direction of the valve member 5, relative to a housing 13 of the gas injection valve 3, which housing can be disposed, in particular in an engine-mounted manner, on the internal combustion engine 1. In particular, the first stop 11 is displaceable between a minimum position, represented in the FIGURE, which defines a minimal maximum stroke, and a maximum position, which defines a maximal maximum stroke for the valve member 5.

[0029] The first stop 11 is disposed on a stop member 15, which is displaceable between a second stop 17, which is arranged in a spatially fixed manner relative to the housing 13, and a third stop 19, which is arranged in a spatially fixed manner relative to the housing 13. The second stop 17 and the third stop 19 are here preferably disposed on the housing 13. The second stop 17 defines the minimum position for the first stop 11, wherein the third stop 19 defines the maximum position for the first stop 11.

[0030] The gas injection valve 3 additionally has a fourth stop 21, which is preferredly configured as a sealing seat for the valve member 5.

[0031] The gas injection valve 3 here has a first displacement mechanism 23 for the displacement of the valve member 5 between the closed position and the open position, and a second displacement mechanism 25 for the displacement of the first stop 11, in particular of the stop member 15, between the minimum position and the maximum position. The first displacement mechanism 23 is preferably of electromagnetic configuration, wherein it has, in particular, an electromagnet 27, wherein the electromagnet 27 is preferably disposed on the stop member 15 or configured as a stop member 15, and, in particular, is displaceable with the stop member 15, and has an armature 29, which is disposed on the valve member 5.

[0032] It is also possible that the valve member 5 is configured as an armature 29. The armature is in particular a magneto armature, which is displaceable by the electromagnet 27. If the electromagnet 27 is energized, the armature 29, and hence the valve member 5, starting from the functional position represented in the FIGURE, is raised in the direction of the electromagnet 27, preferably to the point at which the valve member 5 butts against the first stop 11. The first stop 11 thus defines a maximum stroke position of the valve member 5, which is achievable with the first displacement mechanism 23 at current position of the first stop 11, and hence defines the maximum stroke, as well as the open position.

[0033] The second displacement mechanism 25 preferably has an actuatable rotary drive 31, which is preferably configured as an electric motor, wherein the rotary drive 31 cooperates with a thread 33, which in particular is configured as a fine-pitch thread, in order to adjust the first stop 11.

[0034] The gas injection valve 3 has, in particular, the adjusting element 35, which is displaceable jointly with the stop member 15 and which has a thread 33.1, here namely an external thread, that meshes with a second thread 33.2, which is arranged in a spatially fixed manner relative to the housing 13 and which here in particular is configured as an internal thread, wherein the rotary drive 31 is designed and arranged to rotationally drive the adjusting element 35. In this case, the stop member 15 is here configured as an adjusting element 35. Alternatively, it is also possible that the adjusting element 35 is disposed on the stop member 15 or is part of the stop member 15.

[0035] If the adjusting element 35 is rotated by the rotary drive 31, its first thread cooperates 33.1 with the second thread 33.2, so that the stop member 15 is displaced, together with the first stop 11, in the stroke direction of the valve member 5. In this case, the unit comprising the rotary drive 31 and the stop member 15 can here be displaced between the second stop 17 and the third stop 19, whereby the first stop 11 is displaced between the minimum position and the maximum position. In this way, by actuation of the rotary drive 31, the maximum stroke of the gas injection valve 3 is adjustable. This can be done, in particular, during the operation of the gas injection valve 3, and hence also of the internal combustion engine 1, wherein an adjustment of the maximum stroke, preferably on a time scale of less than 1 second, is possible. A fully transient operation of the internal combustion engine 1, with variation of the maximum stroke, can thus be ensured.

[0036] Within a method for operating the internal combustion engine 1 with the gas injection valve 3, a gas quantity, to be injected, of the combustion gas is set on an operating-point-dependent basis, that is to say in dependence on instantaneous operating point of the internal combustion engine 1, by adjustment of the maximum stroke of the valve member 5. At the same time, actuation times or energization times for the gas injection valve 3 are preferredly chosen on an operating-point-dependent basis, that is to say in dependence on an instantaneous operating point of the internal combustion engine 1, with a view to an optimized mixture formation in the at least one combustion chamber 7 of the internal combustion engine 1. It is here preferredly provided that, upstream of the gas injection valve 3 in a combustion gas supply line 37 of the internal combustion engine 1, is set a constant combustion gas pressure, which accordingly, in particular, is not varied in dependence on an operating point of the internal combustion engine 1.

[0037] Preferably, an internal combustion engine 1 is operated with a plurality of combustion chambers 7, wherein to each combustion chamber 7 or to each combustion chamber assembly of combustion chambers 7 is assigned an, in particular separate, gas injection valve 3. The actuation times or energization times for the gas injection valves 3, and/or the maximum stroke of the valve member 5, are set separately for each gas injection valve 3 of the internal combustion engine 1. In this way, in particular an equalization of the combustion chambers for the internal combustion engine 1 can be performed.

[0038] The gas injection valve 3 is preferredly designed for multipoint injection or single-point injection into the charging path 9 of the internal combustion engine 1. It is also possible, however, that the gas injection valve 3 is designed for the direct injection of combustion gas into the combustion chamber 7.

[0039] Overall, it turns out that, with the here proposed gas injection valve 3, the internal combustion engine 1 and the method for operating the internal combustion engine 1, an improved engine running with improved emissions, in particular combined with improved no-load operation, unrestricted full-load operation and improved power boost, is realized. An improved long-term stability both of the gas injection valve 3 and of the internal combustion engine 1 is here also achieved, wherein a wearing of the charging path 9 and/or of the gas injection valve 3 can be offset by suitable adjustment of the maximum stroke. Due to the maximum stroke as an additional parameter for the quantity control of the combustion gas quantity to be injected, an optimal energization period for the gas injection valve 3 throughout the operating range of the internal combustion engine 1 can be set, wherein the energization times can differ in dependence on the operating point. In particular optimal energization times can here respectively be chosen for a no-load operation and for a full-load operation of the internal combustion engine 1.