Prechamber ignition plug for internal combustion engine and internal combustion engine

Abstract

The invention relates to a pre-chamber ignition plug (22) for a combustion chamber (18) of an internal combustion engine (10), having a pre-chamber (30) and a plurality of connecting channels (36a, b) by means of which the pre-chamber (30) can be brought into fluid communication with the combustion chamber (18) and by means of which a fuel-air mixture can be conducted from the combustion chamber (18) into the pre-chamber (30), wherein at least one of the connecting channels (36a, b) has, at its end (E1) opposite the pre-chamber (30) into which the fuel-air mixture can be conducted, a first partial region (T1) extending in the peripheral direction of the at least one connecting channel (36a) which has a bevel (F) of the at least one connecting channel (36a) and a second partial region (T2) adjoining the first partial region (T1) in the peripheral direction of the at least one connecting channel (36a) and extending in the peripheral direction of the at least one connecting channel (36a), in which second partial region the at least one connecting channel (36a) has no bevel.

Description

Technical Field

[0001] This invention relates to a pre-combustion chamber ignition plug for internal combustion engines, particularly motor vehicles. The invention also relates to an internal combustion engine having at least one such pre-combustion chamber ignition plug. Background Technology

[0002] DE 10 2018 007 093 A1 discloses a pre-combustion chamber igniter for an internal combustion engine combustion chamber. The pre-combustion chamber igniter has a pre-combustion chamber with multiple openings, through which it is in fluid communication with the combustion chamber. Thus, a fuel-air mixture can be fed from the combustion chamber into the pre-combustion chamber through the openings. It is also specified that the openings are designed to create a turbulent flow of the fuel-air mixture flowing into the pre-combustion chamber through the openings.

[0003] WO 2013 / 141681 A1 also disclosed an ignition plug. Summary of the Invention

[0004] The objective of this invention is to provide a pre-combustion chamber igniter and an internal combustion engine having such a pre-combustion chamber igniter, thereby enabling very stable combustion in the pre-combustion chamber igniter.

[0005] This task is accomplished using a pre-combustion chamber igniter and an internal combustion engine.

[0006] The first aspect of the invention relates to a pre-combustion chamber ignition plug for the combustion chamber of an internal combustion engine, particularly a motor vehicle. This specifically means that a motor vehicle, for example designed as an automobile, and especially a passenger car, has this internal combustion engine in its fully manufactured state and can be driven by an internal combustion engine, for example designed as a piston engine or piston machine. The internal combustion engine here has, for example, a driven shaft, which can be designed as a crankshaft, especially when the internal combustion engine is designed as a piston engine or piston machine. For example, the internal combustion engine has an engine housing, particularly designed as a cylinder housing and especially a cylinder crankshaft housing, also referred to as an engine assembly, and for example has, forms, or defines at least one cylinder. Here, for example, the piston of the internal combustion engine is movably housed within the cylinder, such that the piston and the cylinder each partially define the combustion chamber. The piston is connected to the driven shaft, especially the crankshaft, for example, by a crank hinge, so that the translational motion of the piston within the cylinder can be converted into rotational motion of the driven shaft. Therefore, the driven shaft can rotate about a rotational axis relative to the module housing. Through the driven shaft, the internal combustion engine can provide torque for driving the motor vehicle. Especially during the ignition and operation of an internal combustion engine, liquid fuel and air are introduced into the combustion chamber. This air and fuel mixture, also known as fresh air, or simply a component of the fuel-air mixture, is at least temporarily contained within the combustion chamber. The pre-combustion chamber igniter, also simply called the ignition plug, has a pre-combustion chamber, which is at least partially, especially at least primarily and more than half, or even completely directly defined or constituted by, for example, the housing of the pre-combustion chamber igniter. Preferably, this housing is separately constructed from and additionally provided to the engine housing, and can be at least indirectly held onto the engine housing. The pre-combustion chamber igniter has multiple connecting channels through which the pre-combustion chamber is in fluid communication with or in direct communication with the combustion chamber. For example, each connecting channel is formed in the housing of the pre-combustion chamber igniter, i.e., is, for example, is directly defined, especially, entirely, by the housing of the pre-combustion chamber igniter. Therefore, it is preferably specified that the pre-combustion chamber igniter is particularly completely fluidly isolated from the combustion chamber except for the fluid communication between the pre-combustion chamber and the combustion chamber achieved by each of its respective connecting channels. The mixture can be fed from the combustion chamber into the pre-combustion chamber via a connecting channel. If, for example, the piston moves from bottom dead center to top dead center, then, for example, the mixture previously contained in the combustion chamber, i.e., at least a portion of the mixture, is fed from the combustion chamber through the connecting channel, i.e., through the connecting channel, into, and particularly forced into, the pre-combustion chamber. In the pre-combustion chamber, a pre-combustion chamber igniter can provide or generate at least one ignition spark. With the aid of the ignition spark, the mixture flowing into and at least temporarily contained in the pre-combustion chamber is ignited and thus combusted. This results in a so-called torch, which flows through the connecting channel and thus enters the combustion chamber via the connecting channel, where it ignites the mixture remaining in the combustion chamber, which then combusts.

[0007] In order to achieve stable combustion in the pre-combustion chamber and therefore in the pre-combustion chamber igniter, the present invention specifies that at least one or exactly one connecting channel has at least one or exactly one first partial region extending circumferentially in the at least one connecting channel at its end opposite the pre-combustion chamber and therefore on the combustion chamber side, which allows the fuel-air mixture to be fed into or flow into the at least one connecting channel, having a particularly purposefully manufactured bevel / sloping / chamfer (Fase) on that end, and at least one or exactly one second partial region extending circumferentially in the at least one connecting channel, which is particularly directly connected to the first partial region and therefore to the bevel, in the at least one connecting channel, where the at least one connecting channel or its combustion chamber side end does not have a purposefully manufactured bevel. In other words, the partial region is a partial region of the combustion chamber side end and, consequently, at least one connecting channel, wherein the combustion chamber side end or at least one connecting channel has a purposefully manufactured bevel in the first partial region at its combustion chamber side end, and wherein the combustion chamber side end or at least one connecting channel does not have a purposefully manufactured bevel in the second partial region at its combustion chamber side end. Specifically, it is specified that the at least one connecting channel and thus the local region, especially the inclined edge, terminates at an edge, also known as the end edge, on the combustion chamber side, particularly when viewed from the combustion chamber in the longitudinal extension direction of the at least one connecting channel, or conversely, begins from the combustion chamber towards the pre-combustion chamber in the longitudinal extension direction of the at least one connecting channel, wherein, for example, the edge completely circumferentially defines the inlet of the at least one connecting channel. Through its inlet, the at least one connecting channel leads into the combustion chamber, thereby allowing the mixture to flow into the at least one connecting channel through the inlet, flow through the at least one connecting channel from the inlet, flow out of the at least one connecting channel and into the chamber, thus flowing into or being guided into the pre-combustion chamber via the at least one connecting channel. Here, the mixture may, for example, flow along or toward a flow direction pointing towards the combustion chamber through the at least one connecting channel, which extends, for example, coincidentally with or parallel to the longitudinal extension direction of the at least one connecting channel. Preferably, it is specified that the aforementioned circumferential direction of the at least one connecting channel extends around the flow direction, i.e., around the longitudinal extension direction of the at least one connecting channel. Because the bevel is now arranged or manufactured in the first local area but not in the second local area, and because there is no intentionally manufactured bevel in the second local area, the bevel does not extend completely around the entrance in the circumferential direction of at least one connecting channel. Instead, the bevel extends only around the first part of the entrance in the circumferential direction of at least one connecting channel. In the circumferential direction of at least one connecting channel, the edge or the second local area extends around the second part of the entrance, which is particularly directly connected to the first part in the circumferential direction of at least one connecting channel. Therefore, there is no bevel and therefore no other intentionally manufactured bevel extending around it.

[0008] In other words, the pre-combustion chamber igniter, for example, is designed to be particularly solid, and its housing wall, which completely surrounds the edge of at least one connecting channel in the circumferential direction, has a first wall extending around the first portion of the inlet in the circumferential direction of at least one connecting channel, and a second wall extending around the second portion of the inlet in the circumferential direction of at least one connecting channel, wherein, preferably, the second wall is directly in contact with the first wall in the circumferential direction of at least one connecting channel. The first wall has a bevel, i.e., a bevel is intentionally formed in the first wall, while the second wall does not have a intentionally formed bevel.

[0009] Here, the present invention is particularly based on the understanding that pre-combustion chamber igniters typically have a limited operating range. Pre-combustion chamber igniters have a reduced low-load stable operating limit (the potential for combustion shutdown at low loads) or a higher pre-ignition susceptibility. A powerful means of regulation, i.e., improving or expanding the operating range of the pre-combustion chamber igniter and thus having a good possibility of applying its limits, is the flow design within, for example, the connecting channels designed as orifices. This specifically refers to particularly targeted influence on the flow through the respective connecting channels, or at least one of them, to improve the operating range. Flow refers to the flow of the mixture through the respective connecting channels. Alternatively or additionally, flow may refer to the respective connecting channels being designed accordingly to advantageously or targetedly influence the flow of the mixture through the respective connecting channels.

[0010] Typically, the flow of the mixture within the respective connecting channels is determined by the surrounding flow. This surrounding flow, particularly the flow of the mixture in the combustion chamber, also known as the main combustion chamber, can at least partially, and especially at least primarily, surround the pre-combustion chamber. The surrounding flow of the mixture within the combustion chamber can be particularly turbulent, i.e., considered at least substantially turbulent, also known as turbulence. This can result in unilateral or asymmetrical, non-axial, or non-free flow encountering the connecting channels in common pre-combustion chamber igniters. Unilateral, asymmetrical, non-axial, or non-free flow encounters can alter, and particularly adversely affect, the flow through the respective connecting channels and consequently, the flow and purging within or within the pre-combustion chamber.

[0011] If the respective connecting channels lack bevels at their combustion chamber side ends and therefore at their inlets, also known as inlets or orifice inlets, significant flow separation may occur at the inlets, resulting in each connecting channel having only a small effective flow cross-section through which the mixture effectively, i.e., actually flows. This can lead to poor residual gas purging of the pre-combustion chamber. It is also conceivable, particularly by milling, to provide each connecting channel with bevels at its combustion chamber side ends that completely surround the connecting channel, so that the bevels circumferentially surround the connecting channel. For this purpose, for example, milling can be performed axially or symmetrically relative to the connecting channel to create completely surrounding bevels, such that the bevels extend symmetrically around the connecting channel or its inlet, in particular, completely surrounding it. This can advantageously achieve slight separation within the connecting channels, but the result may be poor feed rate efficiency (Fanggrad) of the pre-combustion chamber circulation and insufficient pre-combustion chamber purging.

[0012] The aforementioned problems and disadvantages can now be avoided by the present invention. The present invention provides a particularly advantageous flow of the mixture in and through at least one connecting channel. Specifically, it exhibits high and at least nearly seamless flow through at least one connecting channel, as well as high pre-combustion chamber circulation efficiency. Thus, compared to common solutions, the hot residual gas can be better purged from the pre-combustion chamber, resulting in improved idling stability and low pre-ignition susceptibility. The purging of the pre-combustion chamber or residual gas specifically refers to the exhaust gas from the combustion of the mixture after ignition and combustion in the pre-combustion chamber and combustion chamber, which is referred to as residual gas and is advantageously purged in the present invention, i.e., purged from the pre-combustion chamber, allowing a fresh mixture to flow advantageously through at least one connecting channel and thus from the combustion chamber into the pre-combustion chamber via at least one connecting channel.

[0013] It has been found particularly advantageous that the hypotenuse or its inner circumferential surface is a segment of a hypothetical (i.e., not actually existing, but imaginary) truncated cone, designed to be rotationally symmetric about its central axis, which extends parallel and spaced relative to the longitudinal axis of the at least one connecting channel, the geometric centroid and / or volume centroid and / or centroid and / or center point of the connecting channel located on the longitudinal axis. The longitudinal axis of the at least one connecting channel extends parallel to or coincides with the longitudinal extension direction of the at least one connecting channel. The centroid or center point specifically refers to the at least one connecting channel having a flow cross-section through which the mixture can flow in at least one longitudinal region, extending in an imaginary plane perpendicular to the longitudinal extension direction and therefore perpendicular to the flow direction, wherein the centroid or center point can be the centroid or center point of the flow cross-section. Thus, the hypotenuse is a so-called coaxial hypotenuse, thereby providing particularly advantageous flow conditions for the mixture within the at least one connecting channel.

[0014] The coaxial bevel specifically refers to a bevel manufactured mechanically, i.e., by machining and especially cutting, in a method for manufacturing a pre-combustion chamber igniter. For example, the bevel is manufactured using a conical or truncated conical end mill and further by milling, wherein the end mill can be, for example, especially a conical finger end mill. To manufacture the bevel, the at least one connecting channel at its combustion chamber side end or the housing of the pre-combustion chamber igniter at the combustion chamber side end of at least one connecting channel is machined by a end mill in such a way that the longitudinal central axis of the end mill, which is rotationally symmetrical about its longitudinal central axis, extends parallel to and at the aforementioned distance from the longitudinal axis of the at least one connecting channel, thereby coinciding with the central axis of an imaginary truncated cone.

[0015] Here, to achieve a highly favorable flow condition design, it is indicated that the spacing is greater than 0 mm and at most 5 mm, particularly at most 3 mm. This avoids excessive fluid separation in at least one connecting channel and enables high gas supply efficiency for the pre-combustion chamber circulation.

[0016] Another embodiment features a combustion chamber-side end of the at least one connecting channel with a bevel formed as the only bevel in a first local region, where no other intentionally manufactured bevels are present. This allows for highly favorable flow conditions, thereby enabling the pre-combustion chamber igniter to exhibit a wide operating range.

[0017] In order to achieve favorable flow conditions in a very simple manner, in other designs of the invention, it is specified that the at least one connecting channel is designed to be circular on its inner circumferential side. Therefore, the so-called flow cross-section is preferably designed to be circular.

[0018] In another particularly advantageous embodiment of the invention, the at least one connecting channel is designed as a hole, i.e., manufactured through a hole. This allows for highly advantageous flow conditions to be achieved at a very low cost. In particular, when the at least one connecting channel is designed as a hole, the longitudinal axis of the at least one connecting channel is also referred to as the hole axis, and the at least one connecting channel is designed to be rotationally symmetric about this hole axis. The central axis of the imaginary truncated cone and the hole axis or longitudinal axis of the at least one connecting channel extend parallel to each other and have the aforementioned mutual spacing, thereby enabling a large or wide operating range for the pre-combustion chamber igniter.

[0019] It has been shown that it is particularly advantageous that at least one of the connecting channels, at its other end opposite the pre-combustion chamber on the combustion chamber side, has no bevel (i.e., designed with a sharp edge). This allows for highly advantageous operation of the pre-combustion chamber igniter and the entire internal combustion engine.

[0020] It is conceivable that the at least one connecting channel has a constant flow cross-section through which the mixture can flow throughout its entire extension from one end on its combustion chamber side to its second end facing the pre-combustion chamber and opposite to that other end on the combustion chamber side. Alternatively or additionally, it is conceivable that the at least one connecting channel and the at least one connecting channel are spaced apart from each other at least 90°, especially at least 120°, in the circumferential direction of the pre-combustion chamber, particularly around the main axis or longitudinal extension direction. Alternatively or additionally, it is conceivable that the at least one connecting channel has a constant flow cross-section through which the mixture can flow throughout its entire remaining extension from the inclined side to the pre-combustion chamber.

[0021] Preferably, the bevel is formed or manufactured by machining, especially in a targeted manner, so that the bevel can be manufactured particularly on demand.

[0022] Within the scope of this document, as is commonly understood, a bevel refers to a slope at the combustion chamber side end of at least one connecting passage and therefore particularly at its edge or margin, wherein such edge or margin is formed, for example, by the aforementioned housing or wall portion.

[0023] It is also advantageous that the number or total number of connecting channels for fluidly communicating or fluidly communicating the pre-combustion chamber to the combustion chamber is at most 15.

[0024] A second aspect of the invention relates to an internal combustion engine for a motor vehicle, wherein the internal combustion engine has at least one pre-combustion chamber ignition plug according to a first aspect of the invention. The advantages and advantageous designs of the first aspect of the invention should be regarded as advantages and advantageous designs of the second aspect of the invention, and vice versa.

[0025] A method for manufacturing a pre-combustion chamber igniter for an internal combustion engine combustion chamber, particularly according to the first aspect of the invention, is also disclosed. In this method, a pre-combustion chamber and a plurality of connecting channels are manufactured for the pre-combustion chamber igniter, by means of which the pre-combustion chamber is fluidly connected to the combustion chamber and thereby a fuel-air mixture can be fed from the combustion chamber into the pre-combustion chamber.

[0026] In order to achieve stable combustion in the pre-combustion chamber and thus a wide or large operating range of the pre-combustion chamber igniter, it is specified that at least one of the connecting channels is manufactured such that at least one connecting channel has at least one, or preferably exactly one, first partial region with a purpose-made bevel arranged at the combustion chamber side end opposite the pre-combustion chamber, extending circumferentially in the at least one connecting channel, and at least one, or preferably exactly one, second partial region extending circumferentially in the at least one connecting channel, particularly directly connected to the first partial region, and extending circumferentially in the at least one connecting channel, wherein the at least one connecting channel or its combustion chamber side end does not have a purpose-made bevel. Attached Figure Description

[0027] Other advantages, features, and details of the invention will become apparent from the following description of preferred embodiments, taken in conjunction with the figures. The features and combinations of features mentioned above in the specification, as well as the features and combinations of features mentioned below in the description of the drawings and / or shown individually in the figures, may be used not only in their respective specified combinations, but also in other combinations or individually, without departing from the scope of the invention. The figures illustrate:

[0028] Figure 1 A schematic cross-sectional view of a portion of the internal combustion engine of the present invention having the pre-combustion chamber igniter of the present invention is shown;

[0029] Figure 2 A schematic cross-sectional side view of the pre-combustion chamber ignition plug is shown;

[0030] Figure 3 Another schematic cross-sectional side view of a portion of the pre-combustion chamber ignition plug is shown.

[0031] In the figure, identical or functionally identical parts are labeled with the same reference numerals. Detailed Implementation

[0032] Figure 1 A portion of the internal combustion engine 2 of a motor vehicle, particularly a car designed as a passenger car, is shown in cross-sectional schematic. This means that the motor vehicle, in its fully manufactured state, has an internal combustion engine 10 and can be driven by means of the internal combustion engine 10. Here, the internal combustion engine 10, preferably designed as a piston engine or piston machine, has an engine assembly, for example, formed as a cylinder housing, especially a cylinder crankshaft housing, the portion of which is shown in cross-sectional schematic.Figure 1 The image is visible, shown only schematically, and designated by 12. The engine assembly has at least one cylinder 14. This specifically means that the engine assembly 12 directly defines or forms the cylinder 14. The piston 16 of the internal combustion engine 10 is movably housed in the cylinder 14. The internal combustion engine 10 here has a driven shaft, specifically designed as a crankshaft, through which the internal combustion engine 10 can provide torque for driving the motor vehicle. The piston 16 is connected to the driven shaft via a crank hinge, such that the translational movement of the piston 16 within the cylinder 14 can be converted into rotational movement of the driven shaft.

[0033] Cylinder 14 and piston 16 each partially define the combustion chamber 18 of the internal combustion engine 10, which is also defined by a combustion chamber top 20. The combustion chamber top is formed, for example, by another housing component of the internal combustion engine 10, particularly designed as a cylinder head. This other housing component is preferably separately constructed from and connected to the engine assembly 12. The internal combustion engine 10 also has a pre-combustion chamber ignition plug 22, which will be explained in detail below, associated with the combustion chamber 18.

[0034] Combustion chamber 18 is equipped with at least one first scavenging valve in the form of an intake valve 24, through which fresh air, also known as fresh air, can be introduced into combustion chamber 18. Additionally, liquid fuel, in particular, can be added, especially directly injected, into the combustion chamber. The air and fuel form a fuel-air mixture, simply referred to as a mixture, which is at least temporarily contained or can be contained in combustion chamber 18. The mixture within combustion chamber 18, also known as the main combustion chamber, can be ignited and combusted by means of a pre-combustion chamber igniter 22, thereby producing exhaust gases from internal combustion engine 10. Here, combustion chamber 18 is provided with at least one second scavenging valve in the form of an exhaust valve 26, through which exhaust gases can be expelled from combustion chamber 18.

[0035] exist Figure 1Arrow 28 indicates the flow, also known as the flow around the mixture, in the combustion chamber 18. As can be seen in particular by arrow 28, the flow indicated by arrow 28 is at least substantially turbulent, i.e., tumbling, and thus the flow indicated by arrow 28 is also referred to as turbulence. It can be seen that the flow indicated by arrow 28 moves in a tumbling or rolling motion about a rolling axis (not shown in the figure), the direction of which is perpendicular to a particularly imaginary plane, the direction of which is parallel to the cylinder axis of cylinder 14, which is designed, for example, to be at least substantially rotationally symmetrical about the cylinder axis. In particular, the cylinder axis extends in the longitudinal direction of cylinder 14. The pre-combustion chamber igniter 22 has at least one or exactly one pre-combustion chamber 30, which is at least partially, especially at least primarily and therefore more than half, or even completely, defined directly by the housing 32 of the pre-combustion chamber igniter 22. In particular, the pre-combustion chamber 30 is defined directly by the inner circumferential surface 34 of the housing 32. The pre-combustion chamber ignition plug 22 has multiple, i.e., at least two or exactly two, also referred to as nozzles, connecting channels 36a, b, designed as through holes, through which the pre-combustion chamber 30 is in fluid communication with the combustion chamber 18, also referred to as the main combustion chamber. The fuel-air mixture (mixture) flowing in the combustion chamber 18, indicated by arrow 28, can thus flow from the combustion chamber 18 through the connecting channels 36a, b and therefore be fed into the pre-combustion chamber 30. This means that the mixture flows at least partially from the combustion chamber 18 through the connecting channels 36a, b and thus can flow into the pre-combustion chamber 30, and at least a portion of the mixture flows from the combustion chamber 18 through the connecting channels 36a, b and thus can flow into or be fed into the pre-combustion chamber 30.

[0036] From Figure 2 As can be clearly seen, the pre-combustion chamber igniter 22 has, for example, a plurality of electrodes 38 arranged in the electrode region. With the aid of the electrodes 38, the pre-combustion chamber igniter 22 can generate and thus provide at least one ignition spark in the pre-combustion chamber 30, particularly between the electrodes 38, wherein the pre-combustion chamber igniter 22 can generate or provide an ignition spark in the electrode region and thus in the pre-combustion chamber 30. With the aid of the ignition spark, the mixture within the pre-combustion chamber 30, i.e., a portion of the mixture flowing into the pre-combustion chamber 30, is ignited and thus combusted. The resulting torch flows through connecting channels 36a, b and thus returns from the pre-combustion chamber 30 to the combustion chamber 18 via connecting channels 36a, b. Thus, for example, the mixture remaining in the combustion chamber 18, i.e., another portion of the fuel-air mixture remaining in the combustion chamber 18, is ignited and thus combusted, thereby obtaining the aforementioned exhaust gas.

[0037] Figure 2 Arrow 40 indicates that the mixture flows into and through the connecting channel 36a from the combustion chamber, where "the mixture flows through and into the connecting channel 36a" is also referred to as flow. This can be seen from... Figure 2As can be clearly seen, each connecting channel 36a, b has an end E1 on the combustion chamber side opposite to or away from the pre-combustion chamber 30, and a second end E2 on the pre-combustion chamber side facing the pre-combustion chamber 30 and opposite to or away from its first end E1; the second end is also referred to as the other end. Each connecting channel 36a, b extends continuously and thus uninterruptedly from its respective end E1 to its respective end E2, terminating at either end E1 or E2 and therefore not extending beyond either end E1 or E2. Figure 2 and 3 The longitudinal axes of the connecting channels 36a and 36b are marked with 42a and 42b, respectively. The geometric centroid and / or volume centroid and / or centroid and / or center point of the connecting channel are located on their respective longitudinal axes 42a and 42b. Furthermore, each connecting channel 36a and 36b has its own longitudinal extension direction and thus its own longitudinal extension range. The respective longitudinal axes 42a and 42b extend parallel to or coincide with the respective longitudinal extension direction of the connecting channels 36a and 36b, thus representing their respective longitudinal extension directions. In addition, the respective through-flow direction of each connecting channel 36a and 36b coincides with its respective longitudinal axis 42a and 42b. Therefore, their respective through-flow directions coincide with their respective longitudinal extension directions. Thus, each connecting channel 36a and 36b can be traversed by a mixture, i.e., by a mixture flow, along its respective through-flow direction. As can be seen, the respective through directions and longitudinal extension directions of the connecting channels 36a and b are relative to the main axis 44 of the pre-combustion chamber 30, which is also called or designed as the central axis or longitudinal central axis. Figure 1 Extending at an angle, the pre-combustion chamber is, for example, configured to be at least substantially rotationally symmetrical about the main axis 44.

[0038] In order to achieve a wide operating range for the pre-combustion chamber igniter 22 and thus stable combustion in the pre-combustion chamber 30, such as well as good combustion from... Figure 2 and Figure 3As specified in the figure, the connecting channel 36a (especially regarding connecting channel 36a, b only refers to connecting channel 36a) has a first partial region T1 with a purpose-made inclined side F extending circumferentially around the longitudinal axis 42a of the connecting channel 36a, at its combustion chamber side end E1 opposite to the pre-combustion chamber 30, which can feed the fuel-air mixture from the combustion chamber 18 (main combustion chamber) into the connecting channel 36a. It also has a second partial region T2 that directly connects to the first partial region T1 circumferentially and extends circumferentially around the connecting channel 36a. In the second partial region, the connecting channel 36a does not have a purpose-made inclined side. In the embodiment shown, the inclined side F or the inner circumferential surface of the inclined side is a segment of an imaginary truncated cone, which, for example, directly defines the entrance arranged at the end E1 of the connecting channel 36a circumferentially about its central axis 46 (…). Figure 3 The connection channel 36a is designed to be rotationally symmetric, with its central axis extending parallel to the longitudinal axis 42a of the connecting channel and at a distance A. The geometric centroid and / or volume centroid and / or centroid and / or center point of the connecting channel are located on the longitudinal axis 42a. It is specified that the distance A is greater than 0 mm and at most 3 mm. Furthermore, in the embodiment shown, the end E1 of the connecting channel 36a has a unique hypotenuse F formed in the first local region T1, and no other intentionally formed hypotenuses elsewhere.

[0039] In the embodiment shown, the connecting channels 36a and 36b are designed as holes and therefore circular on their inner circumferential sides. This applies to connecting channel 36a, and particularly to its continuous extension from one end of the connecting channel 36a facing the pre-combustion chamber 30 to its combustion chamber-side end E2. Furthermore, connecting channels 36a and 36b are designed as holes. Connecting channel 36b has no bevels at its other end E1 on the combustion chamber side opposite to the pre-combustion chamber 30, and at its end E2 on the pre-combustion chamber side facing the pre-combustion chamber 30.

[0040] It can be well from Figure 2 and Figure 3 As seen in the diagram, the connecting channel 36b has a constant and therefore preferably circular flow cross-section through which the fuel-air mixture can flow, extending from the combustion chamber side end E1 of the connecting channel 36b to the pre-combustion chamber side end E2 of the connecting channel 36b facing the pre-combustion chamber 30 and opposite to the end E1 of the connecting channel 36b.

[0041] Figure 3 A method for manufacturing the pre-combustion chamber ignition plug 22 is shown. In particular, it can be derived from... Figure 3As seen, the connecting channels 36a and b are formed or defined by the housing 32, particularly directly around the circumference of each connecting channel 36a and b. In other words, the connecting channels 36a and b are formed within the housing 32, particularly along their entire circumference. Therefore, the bevel F is formed, i.e., manufactured, at one wall of the housing 32. To manufacture the bevel F, a milling cutter 48, also known as a milling head, is used, thereby manufacturing the bevel F by cutting. For example, the milling cutter 48 is a finger milling cutter. It can be seen that the milling cutter 48 is a conical milling cutter, particularly a conical finger milling cutter. This means that the milling cutter 48 is conical or truncated conical so that, here, particularly with respect to local areas T1 and T2, the bevel F is manufactured only in local area T1. To achieve the coaxial spacing A, the milling cutter 48 rotates relative to the housing 32 about the central axis 50 of a cone that coincides with the central axis 46. The area of ​​the milling cutter 48, or its conical or truncated conical shape, used to create the bevel F is formed in a rotationally symmetrical manner about the central axis 50. Here, to create the bevel F, the milling cutter 48 is made to directly contact the housing 32 such that the central axis 50 of the cone is parallel to the longitudinal axis 42a and extends at a distance A from the longitudinal axis 42a. Thus, the end E1 of the connecting channel 36a has the bevel F intentionally created only in a local area T1, while the rest of the end E1 remains without an intentionally created bevel. This avoids excessive flow separation in the connecting channel 36a. Furthermore, it achieves a high gas supply efficiency for the pre-combustion chamber circulation, allowing the residual gas originally contained in the pre-combustion chamber 30 to be advantageously purged from the pre-combustion chamber 30.

[0042] List of reference numerals

[0043]

Claims

1. A pre-combustion chamber ignition plug (22) for a combustion chamber (18) of an internal combustion engine (10), having a pre-combustion chamber (30) and a plurality of connecting channels (36a, 36b) through which the pre-combustion chamber (30) is in fluid communication with the combustion chamber (18) and thereby allows a fuel-air mixture to be introduced from the combustion chamber (18) into the pre-combustion chamber (30). Its characteristics are, At least one of the connecting channels (36a, 36b) has a first partial region (T1) extending circumferentially in the at least one connecting channel (36a) with a bevel (F) of the at least one connecting channel (36a) at its end (E1) opposite to the pre-combustion chamber (30) and capable of introducing a fuel-air mixture into the at least one connecting channel (36a), and a second partial region (T2) extending circumferentially in the at least one connecting channel (36a) and connected to the first partial region (T1) in the at least one connecting channel (36a), wherein the at least one connecting channel (36a) does not have a bevel.

2. The pre-combustion chamber ignition plug (22) according to claim 1, characterized in that, The hypotenuse (F) is a segment of an imaginary truncated cone that is rotationally symmetric about its central axis (46), which extends parallel to and with a spacing (A) relative to the longitudinal axis (42a) of the at least one connecting channel (36a, 36b), the geometric centroid and / or volume centroid and / or centroid and / or center point of which is located on the longitudinal axis (42a).

3. The pre-combustion chamber ignition plug (22) according to claim 2, characterized in that, The spacing (A) is greater than 0 mm and at most 5 mm.

4. The pre-combustion chamber ignition plug (22) according to any one of the preceding claims, characterized in that, The end (E1) has a hypotenuse (F) formed in the first local region (T1) as the only hypotenuse, and there are no hypotenuses elsewhere.

5. The pre-combustion chamber ignition plug (22) according to claim 1 or 2, characterized in that, The at least one connecting channel (36a) is designed to be circular on the inner circumferential side.

6. The pre-combustion chamber ignition plug (22) according to claim 1 or 2, characterized in that, The at least one connection channel (36a) is designed as a hole.

7. The pre-combustion chamber ignition plug (22) according to claim 1 or 2, characterized in that, At least one of the connecting channels (36a, 36b) has no bevel at its other end opposite the pre-combustion chamber (30) that allows the fuel-air mixture to be introduced into the at least one other connecting channel (36b).

8. The pre-combustion chamber ignition plug (22) according to claim 7, characterized in that, The at least one connecting channel (36b) has a constant flow cross-section through which the fuel-air mixture can flow over its entire extension from the other end to its second end (E2) facing the pre-combustion chamber (30) and opposite to the other end.

9. An internal combustion engine (10) for a motor vehicle, having at least one pre-combustion chamber ignition plug (22) according to any one of the preceding claims.

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