DE102022200846A1 - MEASURING DEVICE FOR MEASURING THE ROTATIONAL COMPONENTS OF A MEASURING FLOW IN A CYLINDER-SHAPED COMBUSTION CHAMBER OF AN ENGINE - Google Patents

Abstract

The present invention relates to a measuring device (10) for measuring rotational components of a measuring flow (MS) in a cylindrical combustion chamber of an internal combustion engine, having a cylindrical measuring socket (20) with a socket diameter (BD), a socket length (BL) and a socket axis (BA), characterized by a movably mounted flow rectifier (30) with a rectifier body (32) at least in sections in the form of a convex spherical shell segment (34) with a central rectifier axis (ZGA) through the center of curvature (KM) of the spherical shell segment (34) and two transverse rectifier axes (QGA) , which are aligned transversely to the central rectifier axis (ZGA), the rectifier body (32) having a large number of passage openings (36) for the passage of the measurement flow (MS), a measurement unit (40) with a connecting element (42) in a non-positive connection to the flow rectifier (30) for detecting three spatial components of a reaction torque applied to the flow straightener (30) by the measuring flow (MS), the measuring bushing (20) having a bushing length (BL) to bushing radius ratio of between 1.5 and 2.

Description

The present invention relates to a measuring device for measuring rotational components of a measuring flow in a cylindrical combustion chamber of an internal combustion engine, a measuring arrangement with such a measuring device, and a measuring method using such a measuring device.

It is known that the flow situation in the cylindrical combustion chamber of the internal combustion engine is of crucial importance in the construction and design of internal combustion engines. The flow situation in the individual combustion cylinders of the internal combustion engine is based on a large number of influencing variables and is set in particular by the type and geometry of the inlet. Typically, an internal combustion engine has a cylinder head which has intake valves for admitting air or an air-fuel mixture into each of the cylindrical combustion chambers. When constructing the internal combustion engine, great attention is paid to ensuring that this gas or gas mixture can mix and flow into the combustion chamber in as precisely defined and ideal a manner as possible. In order to ensure this, the most accurate knowledge possible of the flow behavior in the cylindrical combustion chamber is required.

It is known that the flow conditions in the cylindrical combustion chamber should be measured. In particular, a so-called integral measurement is carried out here, i.e. the measurement of mechanical reaction variables to flow conditions. It must be taken into account that two flow phenomena in particular are to be recorded within the cylindrical combustion chamber. On the one hand, there is the swirl of the flow, ie a rotational movement with rotational components of the measurement flow around a cylinder axis of the cylindrical combustion chamber. In addition, a cylindrical flow, which is also referred to as a tumble flow, is known. This tumble flow is a rotation of the flow about an axis of rotation transverse to the cylinder axis of the combustion chamber. This tumble flow is a rotational flow about an axis transverse to the longitudinal axis of the cylinder and is to be understood as a corresponding part of the flow field. Flow fields of any complexity can result from the superimposition of different rotation and translation components, such as a toroidal flow field, which represents a superposition of a swirl and a tumble.

Known solutions for determining these rotating flow components are based on recording mechanical measurement variables as reaction forces on the rotating components of the measurement flow, in particular with flat flow straighteners. Flow rectifiers are provided for this purpose, which are inserted into a measuring socket with a flat or planar extension. The cylindrical measuring socket simulates the cylindrical combustion chamber and can now be subjected to a measuring flow and measured in this way through the integration of a flow straightener. A measuring flow is introduced into the cylindrical measuring socket via a measuring object to be measured, for example a part of a cylinder head. The flow straightener arranged therein is now deflected by the at least partially rotating measuring flow that occurs, so that reaction forces to this deflection can be determined on a measuring unit connected to the flow straightener. This allows back calculation to the actual rotational components of the measurement flow that are responsible for these reaction forces and are described with the tumble number.

A disadvantage of the known solutions is that, in particular with regard to the tumble-shaped rotational components of the measurement flow, there is a decisive difference in which axial position along the bushing axis of the cylindrical measuring bushing the flow straightener is arranged. This means that measurement results for different mass flows and/or different bushing diameters of the cylindrical measuring bushing become inconsistent and are therefore difficult or impossible to compare.

It is therefore the object of the present invention to provide a measuring device for different measuring sockets with measuring results that are as comparable as possible for measuring rotational components of a measuring flow in a cost-effective and simple manner.

The above object is achieved by a measuring device with the features of claim 1, a measuring arrangement with the features of claim 17 and a measuring method with the features of claim 19. Further features and details of the invention result from the dependent claims, the description and the drawings. Features and details that are described in connection with the measuring device according to the invention also apply, of course, in connection with the measuring arrangement according to the invention and the measuring method according to the invention and vice versa, so that the disclosure of the individual aspects of the invention is or can always be referred to mutually.

According to the invention, a measuring device is proposed for measuring rotational components of a measuring flow in a cylindrical combustion chamber of an internal combustion engine. Such a measuring device has a cylindrical measuring socket with a socket diameter, a socket length and a socket axis. This measuring device is characterized by a movably mounted flow straightener with a straightener body, at least in sections in the form of a convex spherical shell segment. This convex spherical shell segment has a central rectifier axis through the center of curvature of the spherical shell segment and two transverse rectifier axes which extend transversely to the central rectifier axis. In this case, the rectifier body has a multiplicity of passage openings for the passage of the measurement flow. In addition, the measuring device is equipped with a measuring unit with a connecting element in a non-positive connection to the flow straightener for detecting three spatial components of a reaction torque applied to the flow straightener by the measuring flow. The measuring socket has a ratio of the socket length to the socket radius of between 1.5 and 2. The socket radius is to be understood here as half the socket diameter.

The core idea according to the invention is based on recording mechanical reaction forces and detecting them with a measuring unit. These spatial components in the form of reaction forces or reaction moments are based on an applied reaction moment, which results from the rotational components of the measuring flow within the cylindrical measuring socket. In a known manner, the measurement flow is introduced into the cylindrical measuring socket, which simulates the cylindrical combustion chamber, by a measurement object, for example a cylinder head and/or a corresponding intake valve in a cylindrical combustion chamber. In particular, this is done by suction from the underside of the measuring device.

In the same way as in the cylindrical combustion chamber, the inflowing measurement flow now forms a complex flow situation which, in particular, has different rotational components. Tumble rotation components with a rotation about an axis transverse to the bushing axis are decisive for the consideration according to the invention.

The stated rotational components of the measurement flow cause the flow straightener and in particular the straightener body to be deflected from its rest position. A reaction torque is generated in one or more spatial directions via the non-positive connection with the measuring unit, depending on the alignment and strength of the respective rotational components of the measuring flow. In particular, the applied reaction torque can now be divided into three spatial components and these can be recorded by the measuring unit, so that parameter information about the deflection from a mechanical point of view is made available for each of the three spatial components. The measuring unit thus makes it possible to record mechanical parameters which correlate with the respective deflection of the movably mounted flow straightener. The stronger a measurement flow is formed in one direction around a respective axis, the stronger an associated deflection and the associated reaction moment can be expected.

A further core idea according to the invention is now based on the fact that a spherical shell segment is used as the flow straightener body. A large number of passage openings are arranged in this rectifier body, which, with their inner surfaces, represent the reaction surfaces or impulse receiving surfaces for the rotational components of the measurement flow. Measurement flow thus penetrates into the individual passage openings transversely to the passage directions thereof and, due to this transverse flow, leads to a lateral deflection force in the respective passage opening on the rectifying body.

In order to ensure that the measuring device can not only be used with a very specific cylindrical combustion chamber, but rather can be used for different cylindrical measuring sockets and correspondingly different geometric correlations, a core idea according to the invention is that the ratio of the measuring socket with regard to the socket length to the socket radius is between 1.5 and 2. With this ratio of bush length to bush radius, the value range between 1.7 and 1.9 is preferably not exceeded.

While the distance between the inflow edge into the measuring socket and the flow straightener is essentially irrelevant in the case of rotational components for swirl components of the measurement flow, this distance is essential for tumble-rotation components of the measurement flow. In order to ensure that comparable measuring results can also be achieved for different dimensions of the measuring sockets with the same proportions of the flow straightener, it is now ensured that the ratio between the socket length and the socket radius is between 1.5 and 2 for different measuring sockets. This makes it possible to use the measuring device for different geometries of different measuring sockets and thus, in particular, of different sizes To use combustion chambers and still be able to achieve comparable measurement results.

It should also be pointed out that the measuring unit is preferably arranged below the flow straightener, that is to say downstream of the passage openings along the measuring flow. As a result, the measuring unit has no influence on the measuring flow and in particular on the rotational components of the measuring flow in the cylindrical measuring socket. In addition, the measuring unit can be stored in this way simply and compactly below the flow straightener and accordingly provide a receiving position for supporting the reaction torques.

It can bring advantages if, in a measuring device according to the invention, the central rectifier axis is aligned along the socket axis, in particular in a coaxial manner. This applies in particular when using different cylindrical measuring sockets for all such measuring sockets, so that all cylindrical measuring sockets in a measuring device according to the invention are placed centrally and coaxially with their socket axis on the central straightener axis of the flow straightener. This means, among other things, that regardless of the actual geometric extension of the cylindrical measuring socket, similar measuring conditions are set for the measuring flow for all different geometric configurations, so that the individual measuring results can be easily compared with one another in the preferred manner according to the invention.

It can also bring advantages if, in a measuring device according to the invention, the connecting element of the measuring unit forms the non-positive connection to the flow straightener on the central straightener axis, in particular in or essentially in the center of curvature of the spherical shell segment. The formation of the connecting element on the central rectifier axis means that leverage ratios improve and in particular no additional lever arms form which are spaced transversely to the central rectifier axis. Due to the centered connection of the measuring unit to the flow straightener, this also leads to a simplified recording and determination of the reaction forces in the form of the three spatial components for the reaction torque applied. In particular, this also applies to all different measuring points, since there is no axis offset between the measuring unit and the flow straightener. If, in addition, the measuring unit with regard to the connecting element is mounted with the positioning in or essentially in the center of curvature of the spherical shell segment, these advantages already described are even further reinforced.

It can also be advantageous if, in a measuring device according to the invention, the flow straightener is mounted on the measuring socket so that it can slide along a circumferential socket contact surface over the surface of the spherical shell segment. In other words, the flow straightener is held or even pressed against the socket contact surface of the measuring socket, for example from below, against the flow direction of the measuring flow. Prestressing can also be provided here in order to equip the sliding bearing of these contacting surfaces with a defined sliding force and thus a defined sealing effect. In order to make the sliding contact as advantageous as possible, the socket contact surface is preferably provided with a complementary surface curvature to the surface curvature of the ball socket segment in this area. In other words, the socket contact surface is preferably designed with a concave curvature with the same radius of curvature and the same center of curvature as the convex curvature of the spherical shell segment. At this point, an annular gap is formed between the socket contact surface and the ball shell segment, into which the surface of the ball shell segment slides and out of which this surface slides again. The best possible sealing is to be achieved here with a bearing that is as force-free as possible, in order to achieve the least possible influence on the reaction torques already explained and at the same time rule out a bypass at the passage openings of the flow straightener as far as possible.

In a measuring device according to the preceding paragraph, it can be advantageous if the cross-sectional area of an annular gap formed between the surface of the ball shell segment and the socket contact surface is less than 1% of the cross-sectional area of all through openings of the ball shell segment. The cross-sectional area of all through-openings of the spherical shell segment is, so to speak, the total sum of the possible through-flow area for all through-openings. In other words, the cross-sectional area of all through-openings is the cross-sectional area that is available for the measurement flow to flow through. Compared to this total cross-sectional area of all passage openings, the cross-sectional area of the annular gap is now kept as small as possible in this embodiment, namely less than 1%. Conversely, this means that at least 99% of the measurement flow actually flows through the passage openings and in this way at least 99% of the measurement flow is introduced into the flow straightening function and thus also results in the reaction moment, which is recorded by the measuring unit. The cross section of the annular gap can be understood as a bypass, which would in particular lead to a corresponding measurement error in the measuring unit, since this measurement flow is no longer available for detecting the reaction torque via the bypass. The smaller the cross-sectional area of the annular gap is, the more precisely the measurement of the actual flow conditions of the measurement flow in the measurement socket can be made available.

It is also advantageous if the depth of an annular gap formed between the surface of the spherical shell segment and the socket contact surface is at least twice the maximum passage diameter of the plurality of passage openings in a measuring device according to the invention of the two preceding paragraphs. In principle, it is possible for all passage openings of the flow straightener to have identical or substantially identical passage diameters. However, different passage diameters can also be provided. In the area of said edge gap, care should preferably be taken to ensure that this edge gap has a larger geometric dimension with regard to the extension in depth along the socket contact surface than the passage diameter of a passage opening at this point. Otherwise, if the passage opening is positioned appropriately, it could bridge the depth of the socket contact surface that is too small and in this way provide an undesired seal. The formation of at least twice the maximum passage diameter makes it possible to avoid this bypass and relates in particular to the passage diameter of the passage opening, which is arranged along a circle of latitude on or in the area of the annular gap. As the depth of the annular gap progresses, it can open again, so that a possible jamming of chips or other particles can be avoided in particular through this opening, since these can fall out again in the opening area in the depth of the annular gap. A blockage of the mobility of the flow straightener can be avoided or at least reduced in this way.

There are further advantages if, in a measuring device according to the invention, the plurality of passage openings are aligned in the direction or essentially in the direction of the center of curvature of the spherical shell segment, with the passage opening in particular having a prismatic cross section. The large number of passage openings are thus aligned centrally to a common point, namely the center of curvature of the spherical segment, so that they also provide an improved effect of force for differently aligned swirl flows and tumble flows of the measurement flows. This leads to a reaction torque that is introduced more precisely and to a correspondingly more precise measurement of the three spatial components by the measurement unit. In principle, a wide variety of cross-sectional shapes are possible for the passage openings. In addition to round bores that are particularly easy to produce, however, prismatic cross sections can be preferred, since in this way the stability with regard to the remaining wall thickness, particularly on the inside of the spherical shell segment, is correlated with the lowest possible degree of blockage. A round cross-section of the passage openings is a possible embodiment and should be explicitly included here as the most general prismatic cross-section. A degree of blockage is to be understood within the meaning of the present invention as the ratio of the open cross-sectional area of all passage openings to the blocked cross-sectional area of the remaining closed surface of the spherical shell segment. The larger the obstructed area, the smaller the remaining open cross-sectional area through which the measurement flow must pass. In order to achieve a measurement result that is as unadulterated as possible, it is advantageous to have the lowest possible degree of obstruction. As will be explained later, the degree of obstruction should preferably be kept below 50%, preferably even smaller. Due to the prismatic cross-section in the case of passage openings, a degree of obstruction can be reduced and the desired necessary stability for the flow straightener can nevertheless be maintained. The identical or essentially identical shape is preferably provided for all passage openings. Additionally or alternatively, however, the individual passage openings can also have different passage diameters and/or other passage geometries.

Further advantages can result if, in a measuring device according to the invention, the passage length of at least some passage openings is at least four times as large as the respective passage diameter. The passage length preferably corresponds at the same time to the thickness of the spherical shell segment in the radial direction toward the center of curvature of the spherical shell segment. The passage length of all passage openings is preferably the same or essentially the same. The greater extent along the passage length compared to the passage diameter results in the rectification functionality being improved. The passage length is preferably even up to five times or even up to up to ten times larger to further improve the corresponding rectification function. In particular, very small passage diameters are therefore preferred, which are designed to be correspondingly long in order to provide a sphere that is as thin as possible as the basis for the spherical shell segment and at the same time to form the best possible rectification functionality.

There are further advantages if, in a measuring device according to the invention, the ratio of the maximum bushing diameter of the cylindrical measuring bushing to the diameter of the spherical shell segment is at least 0.7 and/or the ratio of the minimum bushing diameter of the cylindrical measuring bushing to the diameter of the spherical shell segment is at least 0.3. As has already been explained, measuring sockets of different dimensions can be used for one and the same flow straightener. The measuring sockets are adapted to the respective measurement object with regard to their geometric extent, in particular with regard to their socket diameter, and thus simulate combustion chambers of different sizes as a connection to the measurement object. It is now possible, in particular, to designate the maximum bushing diameter as the nominal diameter. Because the ratio of the nominal bushing diameter to the diameter of the spherical shell segment is less than 1, the radial extent of the spherical shell segment is correspondingly larger than the radial extent and thus the bushing diameter of the measuring socket. This leads to the fact that in particular the already explained contacting sliding seal between the measuring socket on the socket contact surface and the surface of the flow straightener is guaranteed. If, in addition, a lower limit for the minimum diameter ratio of at least 0.3 is made available, this means that the minimum bushing diameter is approximately 40% of the maximum bushing diameter of all possible cylindrical test bushings. In other words, a very large bandwidth is made available in this way in order to be able to measure different bushing diameters with one and the same flow straightener in the same measuring device. The larger the diameter of the spherical shell segment, the lower the degree of obstruction, as already defined above. In addition, however, this leads to the fact that the alignment accuracy of the openings decreases, the lever arm for determining a tumble determination increases, and the measuring principle basically deteriorates. It is therefore necessary to find a compromise that is as exact as possible between these different positive and negative effects for a spherical shell segment, which can then also be used for different geometries of the cylindrical measuring socket.

It can also bring advantages if, in a measuring device according to the invention, the plurality of passage openings are distributed over the spherical shell segment at least partially at a distance from the circles of latitude of the spherical shell segment. The circles of latitude are similar to the globe, the degrees of latitude along the segment of the spherical shell. From the pole, which preferably lies on the bushing axis and on the central rectifier axis when the spherical shell segment is at rest, these circles of latitude are arranged concentrically outwards up to the equator of the spherical shell segment. If the through-openings were now to be arranged on the latitudinal circles, in particular in the region of the annular gap already explained, this leads to the disadvantage described below. Due to the action of the measurement flow, the flow straightener moves in particular around one or more of the transverse straightener axes. As a result, on one side of this movement, part of the passage openings enters the annular gap in its depth direction and is therefore covered by the socket contact surface at this point. These covered passage openings are therefore no longer available for the measurement flow to flow through. The opposite movement takes place on the opposite side of the flow straightener. This means that passage openings previously covered by the socket contact surface emerge from the annular gap counter to the depth direction and now provide an additional passage opening for measurement flows. The degree of this movement depends on the mass flow, but not on the changed flow conditions. Depending on the amount of air flow that is introduced into the measuring socket as a measuring flow, this can lead to different measuring results being achieved, since the flow conditions are adjusted by changes in the through-openings in terms of their number and position. In order to avoid this, in the present embodiment an arrangement of the passage opening on the lines of latitude is avoided by being arranged at least partially at a distance from them. As a result, during the movement described, not all through-openings, which are arranged together on a circle of latitude in the region of the edge gap, enter or exit the cover of the annular gap in the depth direction. Rather, only individual through-openings will carry out this entry or exit, so that the effect of the change in the through-openings in terms of number and positioning can be significantly minimized.

It can be advantageous if, in a measuring device according to the invention, the large number of passage openings are arranged at least partially in accordance with a projection of a polyhedron on the spherical shell segment. For example, it is possible to define such a polyhedron by arranging equilateral triangles and adjoining equilateral quadrilaterals, starting from one pole of the spherical shell segment. In order to make such an arrangement available, different arrangement options are conceivable. For example, starting from the pole of the spherical shell segment, it is possible to define individual longitude circles which have defined angular distances of, for example, 30°. Then triangles are formed on the surface of the spherical shell segment, which define uniform edge lengths. Starting from these equilateral triangles on the surface of the spherical shell segment, corresponding equilateral quadrilaterals are arranged downstream, so that an arrangement with equilateral triangles and equilateral quadrilaterals is formed, which can then be further refined inwards. Furthermore, it can be advantageous if the polyhedron is a truncated icosahedron or an icosidodecahedron in such a measuring device according to the invention. For example, icosahedrons, truncated icosahedrons or icosidodecahedrons can be used, which then in turn divide the individual approximated faces into polygons, quadrilaterals or triangles. In the variants mentioned above, a further fine subdivision is then possible until a large number of individual edges and nodes define the individual position for all through openings and in this way provide a defined spacing from the circles of latitude with the advantages mentioned. In addition to an equalization of the result for different mass flows, a reduced degree of blockage is also achieved in this way.

It can also bring advantages if, in a measuring device according to the invention, the large number of passage openings have at least partially different passage diameters. For example, passage diameters can be varied in the range between 2 and 3 mm. In principle, passage diameters between 1.3 and 1.8 mm are also conceivable. Different passage diameters can be varied freely, but can also be varied step by step between two or more different defined exact passage diameters. Varying the passage diameter over the surface of the spherical shell segment also leads to a reduction in the degree of blockage, since, depending on the arrangement position, smaller passage openings can also break through the surface of the spherical shell segment and be available for the rectifying functionality for the measuring flow.

It can also bring advantages if, in a measuring device according to the invention, the center of mass of the flow straightener is arranged in or essentially in the center of curvature of the spherical shell segment. This means that a mass inertia during the deflection of the flow straightener has less or preferably no effect on the reaction forces, so that a falsification of the reaction torque and thus a falsification of the detection of the three spatial components can be reduced to a minimum. The center of mass can be fixed, for example, by appropriate structural configurations on the spherical shell segment. For example, volumes, thicknesses or cavities can be adjusted in such a way that the center of mass is shifted to the desired center of curvature when the flow straightener is designed. The materials for the spherical shell segment can also be appropriately adjusted in terms of their density. Last but not least, it is also possible, in the form of additional masses, which are arranged in particular below the center of curvature, to place the arrangement of the center of mass in or essentially in the center of curvature.

It is a further advantage if, in a measuring device according to the invention, the cylindrical measuring socket has at least one ferromagnetic magnet section, in particular adjacent to an annular gap formed between the surface of the spherical shell segment and the socket contact surface. This ferromagnetic magnet section has the advantage that particles and dirt, in particular in the form of metal chips, are prevented from entering the annular gap that is formed. While the annular gap can open to the rear in order to simply remove any contamination that has entered, the provision of the preferably circumferential magnet section has the aim of already preventing metallic contamination from entering the annular gap. Of course, it is also possible that the inner surface or even the complete measuring socket is made available with the ferromagnetic magnet section design.

There are further advantages if, in a measuring device according to the invention, the flow straightener has a degree of obstruction for the passage of the measuring flow through the plurality of passage openings of less than 50%, in particular less than 40%. As already know As explained several times above, there are various ways of reducing the degree of obstruction. For example, this can be achieved through the optimized arrangement of the through-openings, through optimized through-opening diameters of the through-openings or through an optimized diameter ratio between the measuring socket and the flow straightener. The manufacturing technology must also be taken into account here, so that the remaining wall between the individual passage openings fulfills the necessary mechanical stability for the wall thickness, particularly with regard to the inside of the spherical shell segment.

The present invention also relates to a measuring arrangement for measuring rotational components of a measuring flow in a cylindrical combustion chamber of an internal combustion engine. This has a measuring device according to the present invention and a measurement object with a flow outlet in fluid-communicating connection with the measuring socket of the measuring device. A measuring arrangement according to the invention thus brings with it the same advantages as have been explained in detail with reference to a measuring device according to the invention. The measurement evaluation now makes it possible, for example with the help of a computer program product, to carry out a re-determination on the basis of the recorded mechanical components in the three spatial directions, which are based on the applied reaction torques of the measurement flow. In order to achieve the measurement flow, this measurement arrangement can have a suction fan or be connected to such a fluid-communicating device in order to correspondingly suck the measurement flow through the measurement object through the flow outlet into the measurement socket and out of the measurement socket through the flow straightener.

It can be advantageous if, in a measuring arrangement according to the invention, the measuring device is aligned with one of the transverse rectifier axes parallel or essentially parallel to a crankshaft axis of the internal combustion engine. This also allows a corresponding correlation to be made to the actual effect on a cylinder moving within the combustion chamber of the internal combustion engine with reference to the crankshaft axis moved by this cylinder. The accuracy of the alignment refers to the corresponding arrangement of the inlet areas of the measurement object, which are also aligned to the crankshaft axis in a defined manner on the actual internal combustion engine.

• - Ausbilden einer Messanordnung gemäß der vorliegenden Erfindung,
• - Ansaugen von Messgas durch das Messobjekt und die Messvorrichtung zur Ausbildung einer Messströmung,
• - Aufnehmen von Messwerten mittels der Messeinheit der Messvorrichtung.

In addition, an object of the present invention is a measurement method for measuring rotational components of a measurement flow in a cylindrical combustion chamber of an internal combustion engine. Such a measurement method has the following steps:

• - forming a measuring arrangement according to the present invention,
• - suction of measuring gas through the measuring object and the measuring device to form a measuring flow,
• - Recording of measured values using the measuring unit of the measuring device.

By using a measuring arrangement according to the invention, the measuring method according to the invention brings with it the same advantages as have been explained in detail with reference to a measuring arrangement according to the invention and with reference to a measuring device according to the invention.

• 1 eine Ausführungsform einer erfindungsgemäßen Messvorrichtung,
• 2 eine Detaildarstellung eines Kugelschalensegments,
• 3 eine weitere Detaildarstellung eines Kugelschalensegments,
• 4 eine Detaildarstellung des Kugelschalensegments in einer ersten Position,
• 5 die Darstellung der 4 in einer anderen Position,
• 6 eine Draufsicht auf einen Strömungsgleichrichter,
• 7 eine Draufsicht auf eine weitere Ausführungsform eines Strömungsgleichrichters,
• 8 eine Draufsicht auf eine weitere Ausführungsform eines Strömungsgleichrichters,
• 9 eine seitliche Darstellung einer Messvorrichtung,
• 10 die Darstellung der 9 mit einer anderen Messbuchse und
• 11 eine Ausführungsform einer Messanordnung.

Further advantages, features and details of the invention result from the following description, in which exemplary embodiments of the invention are described in detail with reference to the drawings. They show schematically:

• 1 an embodiment of a measuring device according to the invention,
• 2 a detailed representation of a spherical shell segment,
• 3 another detailed representation of a spherical shell segment,
• 4 a detailed representation of the spherical shell segment in a first position,
• 5 the representation of 4 in another position
• 6 a plan view of a flow straightener,
• 7 a plan view of a further embodiment of a flow straightener,
• 8th a plan view of a further embodiment of a flow straightener,
• 9 a side view of a measuring device,
• 10 the representation of 9 with another test socket and
• 11 an embodiment of a measuring arrangement.

1 shows schematically how a measuring device according to the invention can be constructed. The measuring flow MS can be introduced from above and is then formed inside the measuring socket 20 . The measuring socket 20 forms a combustion chamber in a cylindrical manner internal combustion engine. The bushing diameter BD is adapted to the flow outlet diameter of a flow outlet 112 of a measurement object 110, as will be used later in a measurement arrangement 100 in 11 is shown in more detail.

The measurement flow MS forms two essential rotation components here. On the one hand, a twist is formed around the bushing axis BA. In addition, a tumble flow occurs with a measurement flow MS around a transverse axis, which is aligned parallel to the transverse rectifier axes QGA, which will be explained later, and thus perpendicular to the socket axis BA.

In order to be able to determine the rotational components of this measurement flow MS, the measurement flow MS is rectified. A flow straightener 30 is provided for this purpose and is arranged below the measuring socket 20 . The flow straightener 30 here has a straightener body 32 which has a spherical shell segment 34 . A multiplicity of passage openings 36 through which the measuring flow MS can pass are introduced into this spherical shell segment 34 . The measurement flow MS is in this case from below 1 sucked in and thus leads to a flow through the spherical shell segment 34 through the passage openings 36. Due to the fact that the measurement flow MS now has one or more rotational components, these rotational components generate forces on the side walls of the passage openings 36. The rectifier body 32 is movably mounted, so that this force causes a deflection and a movement of the shot peening segment 34 around the center of curvature KM and thus around the two transverse G rectifier axes QGA and the central rectifier axis ZGA. This alignment can now be detected by the measuring unit 40 in terms of force and displacement, since this is connected to the rectifier body via a connecting element 42 . In the measuring unit 40 or separately therefrom, mechanical restoring elements can reset the rectifier body with restoring forces to the rest position, as shown in FIG 1 is shown, apply.

As can be clearly seen here, a contacting seal takes place between the surface of the spherical shell segment 34 and a socket contact surface 22 on the underside of the test socket 20 . This makes it possible to ensure a main flow of the measurement flow MS through the shot peening segment 34, in particular with less than 1% of the total possible passage area of all passage openings 36.

In order to ensure that one and the same rectifier body 32 can be used for different geometric conditions of the different measuring sockets 20 to be measured, the axial spacing between the surface of the spherical shell segment 34 and the upper entrance as the flow edge of the measuring socket 20 should be taken into account. For this purpose, it is now ensured that for all measuring sockets 20 of different sizes to be used, the ratio between the socket length BL and the socket radius (half of the socket diameter BD shown) is between 1.5 and 2. This means that the measuring socket 20 is always smaller than the corresponding diameter of the diameter of the spherical shell segment 34, which will be explained later, and an arrangement such as that shown in FIG 1 shows can be achieved. Furthermore, the liner size determined in this way helps to ensure uniform flow conditions for combustion chambers of different sizes.

The socket length BL extends from the upper connecting flange for the test object 110 to the contact circumference of the inner lateral surface of the test socket 20 with the surface of the rectifier body 32. This contact circumference thus also forms the entrance of the annular gap 50.

In the 1 a magnet section 24 is also shown, which allows metallic chips and other metallic impurities to be picked up and held magnetically so that they cannot enter the annular gap 50 that forms between the socket contact surface 22 and the surface of the ball shell segment 34 .

The 1 10 also shows that the center of mass MSP of the rectifier body 32 is not only arranged axially on the central rectifier axis ZGA, but also in the center of curvature KM of the spherical shell segment 34. In this way, unwanted levers based on mass inertia can be avoided and the accuracy of the measurement by the measuring unit 40 can be increased.

The 2 shows schematically the geometric relationships of three passage openings 36 arranged next to one another. Of course, there are significantly more passage openings 36, which, however, for the sake of clarity in 2 and are not shown in the following figures. It is easy to see here that the passage length DL is designed to be significantly larger than the passage diameter DD. This means that the rectifying effect and, depending on the impact angle of the measuring flow MS, the resulting effect on the side walls of the passage openings 36 is improved, so that the flow on the underside of the spherical shell is as rectified as possible segment 34 exit. In other words, in this way a maximum of the rotational components of the measurement flow MS is formed into an actual reaction moment in the form of a deflection at the flow straightener 30 .

In the 3 the contacting on the socket contact surface 22 is shown in an enlarged view. Here it is easy to see how the annular gap 50 is formed. It can also be seen here that in the depth direction of the annular gap 50 this has a longer contacting surface in the form of the socket contact surface 22 than the passage diameter DD of the respective passage opening 36 is formed. The depth direction of the annular gap extends along the socket contact surface 22 from its beginning inside the measuring socket 20 to its end at the lower outlet of the measuring socket 20. In particular, the depth direction is twice as long as the maximum passage diameter DD, so that an undesired bridging of this depth direction in the annular gap 50 and thus the formation of an undesired enlarged bypass flow for the measuring flow MS is avoided.

The 4 and 5 show how the passage openings 36 can behave in the area of the annular gap 50 when the spherical shell segment 34 is displaced. The 4 is the original situation and the 5 a position under load of a measurement flow MS. It is easy to see here that part of the passage openings 36 enters the annular gap 50 on the left-hand side as a result of the displacement and is covered by the socket contact surface 22 . To the same extent, part of the passage openings 36 emerges from the annular gap 50 on the opposite right-hand side and thus becomes effective for the measurement flow MS. In order to ensure that the number of passage openings 36 that disappear in this way and appear on the opposite side does not falsify the measurement result, in addition to an embodiment along the circles of latitude for the passage openings 36 of 6 an arrangement spaced from these lines of latitude can be performed. This is for example in the 7 and 8th shown, with the individual passage openings 36 now being arranged on triangle edges and nodes and, in particular, being able to have different individual passage diameters DD.

Based on 9 is again shown schematically that different test sockets 20 can be used. If the bushing diameter BD is reduced in order to be adapted accordingly to a smaller flow outlet 112 of a measurement object 110, the bushing length BL must also be adjusted in order to adjust the relationship between the bushing length BL and the bushing diameter BD and thus also the bushing radius, which represents half the bushing diameter BD. The smaller bush diameter BD according to the 10 accordingly leads to a shorter sleeve length BL compared to the embodiment of FIG 9 .

In the 11 a method according to the invention is again shown on a measuring arrangement 100 according to the invention. The measurement object 110 is shown schematically as part of a cylinder head, over which a flow outlet 112 is formed via a valve inlet. The measurement flow enters through this and, on the basis of the geometric situation in the measurement object 110, can now form the measurement flow MS with the corresponding tumble flow and the corresponding swirl flow, which is now measured.

The above explanation of the embodiments describes the present invention exclusively in the context of examples.

Reference List

10

measuring device

20

measuring socket

22

socket contact surface

24

magnet section

30

flow straightener

32

rectifier body

34

spherical shell segment

36

passage opening

40

unit of measure

42

fastener

50

annular gap

100

measuring arrangement

110

measurement object

112

flow outlet

MS

measuring flow

BD

bushing diameter

BL

socket length

B.A

bushing axle

ZGA

central rectifier axis

QGA

quadrature rectifier axis

KM

center of curvature

MSP

center of mass

DD

passage diameter

DL

passage length

Claims (19)

Measuring device (10) for measuring rotational components of a measuring flow (MS) in a cylindrical combustion chamber of an internal combustion engine, having a cylindrical measuring socket (20) with a socket diameter (BD), a socket length (BL) and a socket axis (BA),marked by a movably mounted flow rectifier (30) with a rectifier body (32) at least in sections in the form of a convex spherical shell segment (34) with a central rectifier axis (ZGA) through the center of curvature (KM) of the spherical shell segment (34) and two transverse rectifier axes (QGA) which are aligned transversely to the central rectifier axis (ZGA), the rectifier body (32) having a large number of passage openings (36) for the passage of the measuring flow (MS), a measuring unit (40) with a connecting element (42) in a non-positive connection to the flow straightener (30) for detecting three spatial components of a reaction torque applied to the flow straightener (30) by the measuring flow (MS), wherein the measuring socket (20) has a ratio of the socket length (BL) to the socket radius of between 1.5 and 2. Measuring device (10) according to claim 1 , characterized in that the central rectifier axis (ZGA) is aligned along the socket axis (BA), in particular in a coaxial manner. Measuring device (10) according to one of the preceding claims, characterized in that the connecting element (42) of the measuring unit (40) forms the non-positive connection to the flow straightener (30) on the central straightener axis (ZGA), in particular in or essentially in the center of curvature (KM) of the spherical shell segment (34). Measuring device (10) according to one of the preceding claims, characterized in that the flow straightener (30) on the measuring socket (20) is slidably mounted along a peripheral socket contact surface (22) over the surface of the spherical shell segment (34). Measuring device (10) according to claim 4 , characterized in that the cross-sectional area of an annular gap (50) forming between the surface of the ball shell segment (34) and the socket contact surface (22) is less than 1% of the cross-sectional area of all through openings (36) of the ball shell segment (34). Measuring device (10) according to one of Claims 4 or 5 , characterized in that the depth of an annular gap (50) forming between the surface of the spherical shell segment (34) and the socket contact surface (22) is at least twice the maximum passage diameter (DD) of the plurality of passage openings (36). Measuring device (10) according to one of the preceding claims, characterized in that the large number of passage openings (36) are aligned in the direction or essentially in the direction of the center of curvature (KM) of the spherical segment (34), the passage openings (36) in particular having a prismatic cross-section. Measuring device (10) according to one of the preceding claims, characterized in that the passage length (DL) of at least some passage openings (36) is at least four times as large as the respective passage diameter (DD). Measuring device (10) according to one of the preceding claims, characterized in that the ratio of the maximum bushing diameter (BD) of the cylindrical measuring bushing (20) to the diameter of the spherical shell segment (34) is at least 0.7 and/or the ratio of the minimum bushing diameter (BD) of the cylindrical measuring bushing (20) to the diameter of the spherical shell segment (34) is at least 0.3. Measuring device (10) according to one of the preceding claims, characterized in that the plurality of passage openings (36) are distributed over the spherical shell segment (34) at least partially at a distance from the circles of latitude of the spherical shell segment (34). Measuring device (10) according to one of the preceding claims, characterized in that the plurality of passage openings (36) are arranged at least partially in accordance with a projection of a polyhedron on the spherical shell segment (34). Measuring device (10) according to claim 11 , where the polyhedron is a truncated icosahedron or an icosidodecahedron. Measuring device (10) according to one of the preceding claims, characterized in that the plurality of passage openings (36) at least partially have different passage diameters (DD). Measuring device (10) according to one of the preceding claims, characterized in that the center of mass (MSP) of the flow straightener (30) is arranged in or essentially in the center of curvature (KM) of the spherical shell segment (34). Measuring device (10) according to one of the preceding claims, characterized in that the cylindrical measuring socket (20), in particular adjacent to an annular gap (50) forming between the surface of the spherical shell segment (34) and the socket contact surface (22), has at least one ferromagnetic magnet section (24). Measuring device (10) according to one of the preceding claims, characterized in that the flow straightener (30) has a degree of obstruction for the passage of the measurement flow (MS) through the plurality of passage openings (36) of less than 50%, in particular less than 40%. Measuring arrangement (100) for measuring rotational components of a measuring flow (MS) in a cylindrical combustion chamber of an internal combustion engine, having a measuring device (10) with the features of one of Claims 1 until 16 and a measurement object (110) having a flow outlet (112) in fluid communication with the measurement socket (20) of the measurement device (10). Measuring arrangement (100) according to Claim 17 , characterized in that the measuring device (10) with one of the transverse rectifier axes (QGA) is aligned parallel or substantially parallel to a crankshaft axis of the internal combustion engine. Measuring method for measuring rotational components of a measuring flow (MS) in a cylindrical combustion chamber of an internal combustion engine, comprising the following steps: - Forming a measuring arrangement (100) with the features of one of claims 17 or 18 - drawing in measurement gas through the measurement object (10) and the measurement device (10) to form a measurement flow (MS), - recording measurement values using the measurement unit (40) of the measurement device (10).