Device for measuring brake emissions
Patent Information
- Application Number
- EP2023798082
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-10-21
- Filing Date
- 2023-10-19
- Publication Date
- 2025-08-27
AI Technical Summary
Current brake test benches face challenges in efficiently directing cooling air and detecting brake emissions from brake discs and pads, often requiring complex flow straightening structures to ensure uniform airflow and effective emission measurement.
A device with a funnel-shaped supply area and perforated plates arranged arbitrarily to straighten the cooling air flow, allowing for efficient cooling and emission detection, eliminating the need for complex structures by ensuring a consistent flow-through area ratio regardless of plate position.
This solution enables simple and effective airflow direction to the test object, ensuring reliable detection and measurement of brake emissions, which can be forwarded to a measuring system for evaluation, enhancing the assessment of brake dust generation without the complexity of elaborate flow structures.
Smart Images
Figure 1.1
Abstract
Description
[0001] Device for measuring brake emissions
[0002] Technical area
[0003] The present invention relates to a device for measuring brake emissions, comprising a housing for accommodating a test specimen, in particular a brake assembly. The housing has a funnel-shaped supply area through which cooling air can be introduced from an air supply duct into the housing through an inlet opening for cooling the test specimen and for detecting the brake emissions. The brake emissions can then be passed from the housing through an outlet opening into an exhaust duct and to a measuring system.
[0004] State of the art
[0005] Environmental pollution with particulate matter caused by vehicles, particularly motor vehicles and trucks, has long been recognized and is subject to increasingly strict legal regulations. To date, the focus has primarily been on particulate matter pollution generated by the combustion process in an internal combustion engine and released into the environment via exhaust gases. Other sources of particulate matter in vehicles have now been identified, with a vehicle's braking system in particular being a potential source of further particulate matter. During vehicle operation—especially during braking—the brake disc and brake pads of the braking system are subjected to wear and tear, releasing extremely fine particles. This abrasion from the brake disc and brake pads enters the environment and can thus contribute to particulate matter pollution, with associated health risks.
[0006] Vehicle and brake system manufacturers are therefore increasingly focusing on reducing the amount of particulate matter generated by the braking system. Brake test benches are often used to develop a braking system, on which the system is assembled and subjected to dynamic tests. In order to better assess the formation and extent of particulate matter generated by brake emissions and brake disc and brake pad wear, brake test benches are often upgraded to record and measure brake emissions, i.e. brake wear. This topic has already been addressed in specialist literature, for example in Kukutschovä J., et al., “On airborne nano / micro-sized wear particles released from low-metallic automotive brakes”, Environmental Pollution 159 (2011), pp. 998-1006.In this case, the brake disc and brake pad are essentially enclosed in a housing on the brake test bench, and the air in the housing is extracted for analysis of the brake emissions. Another example of a corresponding extension of a brake test bench is described in WO 2017 / 097901 A1, which shows a device for detecting and measuring brake dust particles that has been integrated into a brake test bench.
[0007] Furthermore, WO 2018 / 202421 A1 also discloses a device for detecting and measuring brake dust, which is integrated into a brake test bench. In this device, the brake as the test specimen is arranged in an enclosed brake receiving chamber. An air flow is guided through the brake receiving chamber or its housing by means of a blower system, with an air supply duct and an exhaust duct of the blower system being coupled to the brake receiving chamber. The brake receiving chamber, to which the brake is attached, is positioned such that the brake is arranged between an outlet opening of the air supply duct and a funnel-shaped inlet opening of the exhaust duct. Furthermore, the cross-sections of the air supply and exhaust ducts are designed sufficiently large so that the air flow fully encompasses the brake and feeds the brake emissions through the inlet opening of the exhaust duct to the sampling device or the particle measuring device.To even out the air flow, flow guide elements can also be arranged in the supply air duct.
[0008] Such flow guiding elements or flow straighteners have long been known for converting a flow into a flow with a known flow profile or for directing it accordingly. For example, DE 10 2014 111 585 A1 shows a test bench with a cooling gas inflow device in which at least one flow straightener is arranged in a straight section of a supply line via which the cooling gas flow is guided to the test object, to ensure a uniform cooling gas flow. This flow straightener is constructed, for example, from a grid of cooling gas baffles arranged parallel to the straight section and is arranged at a predetermined distance from the outlet opening of the supply line. Furthermore, the cooling gas inflow device also has equidistantly arranged cooling gas deflection plates, for example in a curved section of the supply line, in order to generate a uniform cooling gas flow.To ensure the test specimen is exposed to the most uniform cooling gas flow possible in the receiving area, complex structures, such as multiple flow baffles, are usually required. Particularly in the case of non-linear supply lines, such as curves, funnel-shaped configurations, etc., these baffles must be shaped accordingly (e.g., bent, widened, etc.) and then laboriously arranged in the supply line or supply area to achieve a uniform fluid flow.
[0009] Description of the invention The invention is therefore based on the object of specifying a device for measuring brake emissions, in which a cooling air flow is guided evenly over a test specimen using very simple means in an arbitrarily shaped, in particular funnel-shaped, supply line area and the brake emission to be measured is reliably recorded.
[0010] This object is achieved by a device according to the independent claim. Advantageous embodiments of the present invention are described in the dependent claims.
[0011] According to the invention, the object is achieved by a device for measuring brake emissions, which has a housing for accommodating a test object, in particular a brake assembly. The housing has a funnel-shaped supply area, via which cooling air from an air supply duct can be introduced into the housing through an inlet opening in order to cool the test object and to record the brake emissions. The brake emissions can then be guided together with cooling air from the housing through an outlet opening into an exhaust duct and further to a measuring system. In the funnel-shaped supply area, at least one perforated plate for flow rectification of the cooling air introduced into the housing is arranged at a perforated plate position, wherein the perforated plate position is suitable for attachment of the at least one perforated plate in the supply area - iebetween the inlet opening and an opening to a central receiving area for receiving the test specimen - can be selected as desired.
[0012] The main aspect of the proposed solution is that a flow rectification effect is easily achieved by having at least one perforated plate arranged randomly in the supply line area. This ideally directs the cooling air introduced into the housing onto the test object using very simple means in order to cool it efficiently. Furthermore, this ensures effective recording of the brake emissions in the area surrounding the test object, so that the brake emissions are then passed on together with the cooling air via the outlet opening in the housing and the exhaust air duct to the measuring system for evaluation. Elaborate and complex designs or shapes, for example, consisting of multiple flow plates in the supply line area, are no longer necessary to achieve the desired flow of cooling air.
[0013] Ideally, a diameter of the at least one perforated plate is adapted to a cross-section of the funnel-shaped supply area at the respectively selected perforated plate position. This easily defines an opening area through which the cooling air can flow through the perforated plate - i.e. a number of holes, an arrangement of the holes, a hole diameter, a hole size, etc. or by a hole pattern of the perforated plate. The at least one perforated plate can, for example, have many holes with a small diameter or fewer holes with a larger diameter. Furthermore, the at least one perforated plate can have a hole pattern with holes arranged in rows or holes arranged in a row with a staggered arrangement, wherein the distances between the rows of holes and / or the hole diameters of the holes are designed to be constant. This means that each row of holes has, for example, holes with the same hole diameter which are arranged at the same distance.However, it is also conceivable that the distances and / or hole diameters of the rows of holes are designed differently. For example, the distances between holes in the middle of the perforated sheet can increase and / or a hole diameter can decrease, while towards the edge the distances between the holes decrease and / or the hole diameters increase. However, it is also conceivable that, for example, the distances between holes in the middle of the perforated sheet can decrease and / or a hole diameter can increase, while towards the edge the distances between the holes increase and / or the hole diameters decrease. In this way, a gradient can be applied very easily in the hole pattern in order to direct the flow of cooling air specifically onto the test object and for the recording of brake emissions.
[0014] Alternatively, an arrangement of the holes in the form of concentric circles as a hole pattern of the at least one perforated sheet is also conceivable. In this case, it is also conceivable that the circularly arranged hole circles have the same design - i.e., have holes of the same diameter - and are arranged at a constant distance from one another in the perforated sheet. It would also be possible to design the hole pattern in such a way that, for example, the distances between the holes and / or the hole diameters of the holes in the individual hole circles change with a distance from a central axis of the concentrically arranged hole circles. For example, the distances between holes in the middle of the perforated sheet can increase and / or a hole diameter can decrease, while towards the edge the distances between the holes decrease and / or the hole diameters increase. However, it is also conceivable that, for example,reduce the distances between holes in the middle of the perforated sheet and / or increase the diameter of a hole, while towards the edge the distances between the holes increase and / or the diameters of the holes decrease.
[0015] A practical embodiment of the device for measuring brake emissions provides that, in addition to the at least one perforated plate, a further perforated plate is arranged in the funnel-shaped supply line area for flow rectification of the cooling air. The at least one perforated plate and the further perforated plate can then be arranged at any selectable perforated plate positions in the supply line area - i.e., between the inlet opening and an opening to a central receiving area for receiving the test specimen. Furthermore, it is also possible to arrange at least three or more perforated plates at any selectable perforated plate positions in the funnel-shaped supply line area of the housing. These two, three or more perforated plates can differ in terms of their respective hole patterns (e.g., number of holes, hole diameter, hole pattern, etc.), as long as an identical flow-through opening area is ensured in each case.
[0016] When using at least one perforated plate, this perforated plate is expediently designed such that, regardless of the selected perforated plate position at which the perforated plate is arranged in the funnel-shaped supply area, the ratio between the perforated plate's perforated opening area and the cross-sectional area of the supply area at the selected perforated plate position has a constant value. This means that regardless of the position in the supply area at which the at least one perforated plate is arranged, the ratio between the perforated plate's perforated opening area and the cross-sectional area of the supply area at the perforated plate position is always the same.
[0017] Furthermore, it is advantageous if the housing of the device for measuring brake emissions is hermetically sealed. This means that the housing is sealed against the surrounding environment so that only cooling air can be introduced into the housing via the supply air duct. This cooling air is filtered and appropriately conditioned (with a preset temperature, humidity, etc.).
[0018] Ideally, the device for measuring brake emissions can be combined with or integrated into a dynamic brake test bench. This allows testing of brake assemblies on the brake test bench to be very easily and efficiently combined with the measurement and evaluation of brake emissions.
[0019] Short description of the characters
[0020] The present invention will be explained in more detail below with reference to Figures 1 to 3, which show exemplary, schematic and non-limiting advantageous embodiments of the invention.
[0021] Fig.1 shows an embodiment of a device according to the invention for measuring brake emissions with a housing for receiving a test specimen and a funnel-shaped supply area and at least one perforated plate
[0022] Fig. 2 shows a further embodiment of the device according to the invention for measuring brake emissions with two perforated plates Fig. 3 shows a further embodiment of the device according to the invention for measuring brake emissions with three perforated plates
[0023] Fig. 4a to 4d embodiments of the at least one perforated plate
[0024] Implementation of the invention
[0025] Figure 1 shows, by way of example and schematically, a device 1 for measuring brake emissions BE, which can be combined with or integrated into a dynamic brake test bench. For the sake of simplicity, the embodiment shown in Figure 1 is limited to that portion of the device 1 for measuring brake emissions BE in which a test specimen 2, in particular a brake assembly 2, is mounted during a brake emission test or in which the brake emissions BE - i.e. abrasion on brake discs and brake pads of the test specimen 2 - is recorded by means of supplied cooling air KL during the brake emission test. An air conditioning system in which, for example, temperature, humidity, flow, etc. of the cooling air KL are monitored and regulated, filter units for cleaning the cooling air KL and a measuring system for measuring and evaluating the brake emissions BE (e.g.Brake dust particle concentration, brake dust particle sizes, etc.) are not shown in Figure 1.
[0026] The device 1 for measuring brake emissions BE has a housing 3 in which a test specimen 2 or a brake assembly 2 to be tested is mounted during the brake emissions test. The housing 3 is ideally hermetically sealed to prevent untreated air from penetrating and contaminating the cooling air KL flowing around the test specimen 2. The housing 3 is designed such that the conditioned and air-conditioned cooling air KL, supplied via an air supply duct 4, is evenly directed around the test specimen 2 or the brake assembly 2. The brake assembly 2 is thereby cooled by the cooling air KL. Furthermore, brake emissions BE - in particular brake dust particles that arise during the brake emissions test - are captured by the cooling air KL and forwarded to the measuring system via an exhaust air duct 5.
[0027] For this purpose, the housing 3 has a central receiving area 6 in which the test specimen 2 or the brake assembly 2 is mounted for the brake emissions test. For this purpose, the test specimen 2 can, for example, be arranged on a receiving device (not shown), which supports the test specimen 2 and its components (e.g. brake discs, brake callipers with brake pads, any brake filter devices present, etc.) and ensures stable support of the braking torques during the test. The central receiving area 6 is ideally designed and dimensioned such that brake assemblies 2 of different sizes can be mounted for a test. In this case, the size or dimensioning as well as the design of the central receiving area 6 can be predetermined by the largest brake assembly 2 to be tested in the device 1. The central receiving area 6 can, for example - as shown by way of example in Figure 1 - be approximately cylindrical orbe designed to adapt to a shape of the test specimen 2, wherein the test specimen 2 is mounted in the center of the receiving area 6.
[0028] Furthermore, the housing 3 has a supply area 7 and a discharge area 8, which are arranged on both sides of the central receiving area 6. The supply area 7 extends from an inlet opening 9, via which the housing 2 is connected to the supply air duct 4, to an opening 10 to the central receiving area 6. Analogously, the discharge area 8 extends from an opening 11 to an outlet opening 12, via which the housing 3 is connected to the exhaust air duct 5. During the brake emissions test, the cooling air KL from the conditioning system is guided via the supply air duct 4 through the inlet opening 9 into the housing 3 or into the supply area 7. The cooling air KL flows through the supply area 7 via the opening 10 to the central receiving area 6 and thus to the test object 2. After the cooling air KL has flowed around the test object 2 orAfter the brake emissions BE generated during the brake emissions test have been recorded, the cooling air KL mixed with the brake emissions BE is passed through the opening 11 of the central exception area 6 into the discharge area 8. From there, the cooling air KL mixed with the brake emissions BE is passed through the outlet opening 12 into the exhaust air duct 5 and further to a sampling position for the measuring system.
[0029] In order to ensure a uniform flow of the cooling air KL through the housing 3 and a corresponding mixture of the cooling air KL with the brake emissions BE in the central receiving area 6, the supply area 7 and the discharge area 8 are designed, for example, conical or trapezoidal. In this case, for example, a diameter of the inlet opening 6, which also corresponds to the diameter of the supply air duct 4, is smaller than a diameter of the opening 10 to the central receiving area 6, whereby the supply area 7 has the shape of a funnel or is designed funnel-shaped. The funnel shape of the supply area 7 is designed such that a transition from the inlet opening 6 to the opening 10 or to the central receiving area 6 is smooth and continuous - i.e., without abrupt changes in cross-sections along the course of the supply area 7. For this purpose, the inlet opening 6 can be dimensioned such that a smooth transition angle (e.g.from 15° to 30°) in the direction of opening 10 to the central receiving area 6 is ensured.
[0030] Furthermore, the discharge area 8 can also be conical or trapezoidal, wherein the diameter of the outlet opening 12, which also corresponds to the diameter of the exhaust air duct 5, is smaller than the opening 11 of the central receiving area 6 to the discharge area 8. This means that the discharge area 8 also has a funnel shape, which can be designed analogously to the supply area 7 without abrupt changes in cross-sections over the course of the discharge area 8. For this purpose, it can also be provided that the outlet opening 12 is dimensioned such that a smooth transition angle (e.g. 15° to 30°) in the direction of the opening 11 to the central receiving area 6 is ensured.
[0031] Ideally, the housing 3 is designed symmetrically to a horizontal axis A and to a vertical axis B of the housing 3, with the two axes A and B intersecting in the center of the central receiving area 6. This means that the funnel shape of the supply area 7 and the discharge area 8 is identical, with the supply area 7 and the discharge area 8 intersecting the, for example, cylindrically shaped, central receiving area 6 in the respective opening 10, 11. Furthermore, the housing 3 is ideally aligned so that the cooling air only enters and exits in a horizontal direction - i.e. in the direction of the horizontal axis A of the housing 3.
[0032] In order to ensure the most uniform flow of cooling air KL in the housing 3 - especially in the central receiving area 6 and around the test piece 2 - at least one perforated plate 13 is arranged at at least one perforated plate position P in the supply area 7. The perforated plate 13 serves to straighten the flow of the cooling air KL introduced into the housing 7 via the inlet opening 9. The perforated plate position P of the at least one perforated plate 13 in the supply area 7 can be selected as desired. For attaching the at least one perforated plate 13 in the supply area 7, at least one of the predetermined perforated plate positions P1, P2, P3 can be selected. This means that the at least one perforated plate 13 can - for example as shown in Figure 1 - be attached at any perforated plate position P, which can be in the area of the inlet opening 9 of the supply area 7 up to the area of the opening 10 to the central receiving area 6.Thus, for example, a position in the area of the inlet opening 9, a position in the area of the opening 10 to the central receiving area 6, or any position in the supply area 7 in between can be selected as the perforated plate position P for the at least one perforated plate 13. Furthermore, the at least one perforated plate 13 can be provided with a filter mat 16, for example, to additionally filter the cooling air KL and enhance a flow-influencing effect.
[0033] The diameter of the at least one perforated plate 13 is adapted to a respective cross-section of the supply area 7 at the respectively selected perforated plate position P. This means that the diameter of the at least one perforated plate 13 increases the closer it is arranged to the opening 10 of the central receiving area 6. The largest diameter of the at least one perforated plate 13 at a selected perforated plate position P is in the area of the opening 10 to the central receiving area 6. The smallest diameter of the perforated plate 13 at a selected perforated plate position P is in the area of the inlet opening 9. The opening area through which the cooling air KL can flow can therefore be defined by the at least one perforated plate 13 - in particular by a number of holes, an arrangement of the holes, a hole diameter, a hole size, etc. or by a hole pattern of the perforated plate 13.
[0034] For this purpose, the at least one perforated plate 13 can, for example, have a larger number of holes with a smaller diameter or smaller hole size. Alternatively, only a smaller number of holes with a larger diameter or larger hole size can be provided in the at least one perforated plate 13.
[0035] As a hole pattern, the at least one perforated plate 13 can, for example, have holes arranged in rows, as shown by way of example in Figures 4a and 4b. The rows of holes can, for example, be offset from one another, as shown by way of example in Figure 4b. It is also conceivable for the holes in the perforated plate 13 to be arranged in the form of concentric circles, as shown by way of example in Figures 4c and 4d. Both with a row-like arrangement of the holes (with or without offsetting of the rows) and with an arrangement of the holes in concentric circles, the distances between the rows of holes / circles can be constant and all holes can have the same diameter or size.
[0036] However, it is also possible for the at least one perforated plate 13 to be designed such that the distances between the rows of holes or hole circles and / or the hole diameters or sizes change depending on the row of holes or hole circle, for example with a distance towards the center of the at least one perforated plate 13 or towards the edges of the at least one perforated plate 13 (e.g. a larger distance between the holes and / or smaller holes in a central region of the perforated plate 13 and a smaller distance between the holes and / or larger holes in the edge regions of the perforated plate 13 or vice versa - i.e. a smaller distance between the holes and / or larger holes in the central region of the perforated plate 13 and a larger distance between the holes and / or smaller holes in the edge regions of the perforated plate 13). This means that a gradient is applied in the hole pattern of the at least one perforated plate 13 in order to additionally direct the flow of the cooling air KL in a desired direction.Figures 4c and 4d show exemplary embodiments for circularly arranged holes.
[0037] Furthermore, the design of the perforated plate 13 can be adapted to the respectively selected perforated plate position P in the supply line region 7. For this purpose, the perforated plate 13 can, for example, be designed such that a ratio of the opening area of the at least one perforated plate 13 through which the cooling air KL flows and a cross-sectional area of the funnel-shaped supply line region 7 has a constant value. The ratio is therefore always the same, regardless of the respectively selected perforated plate position P at which the perforated plate 13 is attached in the supply line region 7. This means that regardless of whether the at least one perforated plate 13 is attached at a perforated plate position P near the inlet opening 9 or near the opening 10 to the central receiving region 6, the ratio of the surface through which the cooling air KL can flow to the cross-sectional area of the supply line region 7 remains the same at the perforated plate position P.
[0038] Ideally, if necessary, additional perforated plates 13 can be arranged in a staggered manner in the supply line area 7 in order to guide the cooling air KL evenly over the test specimen 2. The additional perforated plates 13 can be provided at any perforated plate positions P in the supply line area 7. The individual perforated plates 13 arranged in the supply line area 7 can differ in terms of their hole pattern - i.e. number of holes, arrangement of the holes, hole pattern, hole diameter used and / or hole sizes, etc. - as long as the respective hole pattern ensures the same opening area through which air can flow. Furthermore, all or only some of the perforated plates 13 installed can be provided with filter mats 16.
[0039] In the following, Figures 2 and 3 show embodiments of the device 1 for measuring brake emissions BE, in which, for example, in addition to the at least one perforated plate 13, a further perforated plate 14 or a third perforated plate 15 is provided in the supply line area 7. The embodiments shown as examples in Figures 2 and 3, however, do not represent a restriction to two or three perforated plates 13, 14, 15, but are merely examples of an arrangement of more than one perforated plate 13 in the supply line area 7. Of course, more than three perforated plates 13, 14, 15 can also be arranged in the supply line area 7, if appropriate.
[0040] Figure 2 again shows the partial area of the device 1 for measuring brake emissions BE, in which the test piece 2 or brake assembly 2 is mounted during a brake emissions test. That is, the housing 3 with the central receiving area 6 for receiving the test piece 2, the funnel-shaped supply area 7 and the funnel-shaped discharge area 8. In the embodiment of the device 1 for measuring brake emissions BE shown in Figure 2, in addition to the at least one first perforated plate 13, a further, second perforated plate 14 is provided in the funnel-shaped supply area 7. The first perforated plate 13 is arranged at the first perforated plate position P1. The further, second perforated plate 14 is mounted, for example, at the second perforated plate position P2. Both the first perforated plate position P1 and the second perforated plate position P2 in the supply area 7 can be selected as desired. In Figure 2, the first perforated plate 13 is, for example,arranged closer to the opening 10 to the central receiving area 6 than the second perforated plate 14. As a result, the first perforated plate 13 has, for example, a larger diameter than the second perforated plate 14, since both perforated plates 13, 14 are adapted to a respective cross-section of the supply area 7 at the respectively selected perforated plate position P1, P2. To filter the cooling air KL and to reinforce the flow-influencing effect, a filter mat 16 can be provided on both perforated plates 13, 14 or (as shown by way of example in Figure 2) only on one of the two perforated plates 13, 14. However, it is also conceivable that neither of the two perforated plates 13, 14 has a filter mat 16. Furthermore, both perforated plates 13, 14 can differ in terms of the hole pattern - that is, in the number of holes, arrangement of the holes, hole pattern, hole diameter used and / or hole sizes, etc.- as long as the same flow-through opening area is ensured by the respective hole pattern.
[0041] Figure 3 shows an embodiment of the device 1 for measuring brake emissions BE, in which, in addition to a first perforated plate 13 and a further, second perforated plate 14, a third perforated plate 15 is arranged in the supply line area 7. Figure 3 again shows the partial area of the device 1 for measuring brake emissions BE in which the test specimen 2 or brake arrangement 2 is mounted during a brake emissions test. That is, the housing 3 with the central receiving area 6 for receiving the test specimen 2, the funnel-shaped supply line area 7 and the funnel-shaped discharge area 8. The first perforated plate 13 is arranged at the first perforated plate position P1. The second perforated plate 14 is arranged at the second perforated plate position P2 and the third perforated plate 15 at a third perforated plate position P3. Any position in the supply line area 7 can be selected for each of the three hole positions P1, P2, P3.
[0042] 3, for example, the first perforated plate 13 is arranged closer to the opening 10 to the central receiving area 6 than the second perforated plate 14 and the third perforated plate 15. Furthermore, the selected third perforated plate position P3 of the third perforated plate 15 is, for example, closer to the inlet opening 9 than the first perforated plate position P1 of the first perforated plate 13 and the second perforated plate position P2 of the second perforated plate 14. Since the diameters of the perforated plates 13, 14, 15 are again adapted to the cross-section of the supply area 7 at the respective perforated plate position P1, P2, P3, for example the diameter of the first perforated plate 13 at the first perforated plate position P1 is larger than the diameter of the second perforated plate 14 at the second perforated plate position P2, which in turn is larger than the diameter of the third perforated plate 15 at the third perforated plate position P3.Again, all three perforated plates 13, 14, 15 or just individual ones of the perforated plates 13, 14, 15 can be provided with filter mats 16 to filter the cooling air KL and to enhance the flow-influencing effect or flow rectification. However, it is also conceivable that none of the perforated plates 13, 14, 15 has a filter mat 16. Furthermore, the three perforated plates 13, 14, 15 can differ in their hole pattern—that is, in the number of holes, arrangement of the holes, hole pattern, hole diameter used and / or hole sizes, etc.—as long as the respective hole pattern ensures the same flow-through opening area.
[0043] Figures 4a to 4d show exemplary embodiments of the at least one perforated plate 13 or of the possible further perforated plates 14, 15. In particular, Figures 4a to 4d show exemplary possible, different hole patterns which the at least one perforated plate 13 can have. In Figure 4a, for example, a row-shaped arrangement of the holes is shown as a hole pattern of the at least one perforated plate 13, wherein the holes have the same hole size and a constant distance between the rows of holes. Furthermore, the holes of the rows of holes are arranged next to or below one another in both a horizontal and a vertical direction. Figure 4b shows a hole pattern with offset rows of holes, wherein the holes also have the same hole size and the rows of holes have a constant distance. For example, every second row of holes is offset from a previous or subsequent row of holes. This means that a hole in a row of holes is located, for example,in the vertical direction below the distance between two holes in a preceding or subsequent row of holes. However, it is also conceivable that the hole size of the individual rows of holes and / or the distance between the rows of holes varies in the embodiments shown in Figures 4a and 4b.
[0044] Figures 4c and 4d show further possible embodiments of the at least one perforated plate 13 or the associated hole pattern. The holes in the perforated plate 13 are arranged in the form of concentric circles. Even when the holes are arranged in concentric circles, the distances between the rows of holes (circles) can be constant and all holes can have the same diameter or size. However, it is also possible for the at least one perforated plate 13 to be designed such that the distances between the hole circles change - e.g., as shown in Figure 4c, with a distance to the center of the at least one perforated plate 13 becoming larger. Alternatively, the distances could also become larger towards the edges of the at least one perforated plate 13. However, a hole size of the individual hole circle (e.g.or smaller holes in a central region of the perforated plate 13 and larger holes in the edge regions of the perforated plate 13, or vice versa). Furthermore, it is also conceivable that—for example, as shown in Figure 4d—a hole size changes in addition to the distance between the hole circles in order to apply a gradient through the hole pattern of the at least one perforated plate 13, which additionally directs the flow of the cooling air KL in a desired direction. List of reference symbols.
[0045] 1 device for measuring brake emissions
[0046] 2 Test specimen or brake arrangement
[0047] 3 housings
[0048] 4 supply air duct
[0049] 5 exhaust air duct
[0050] 6 central recording area
[0051] 7 funnel-shaped supply area
[0052] 8 funnel-shaped drainage area
[0053] 9 Inlet opening
[0054] 10 Opening to the central receiving area
[0055] 11 Opening to the drainage area
[0056] 12 Outlet opening
[0057] 13 (first) perforated sheet
[0058] 14 additional / second perforated sheet
[0059] 15 third perforated sheet
[0060] 16 filter mat
[0061] BE brake emissions or brake dust particles
[0062] KL cooling air
[0063] A horizontal axis
[0064] B vertical axis
[0065] P, P1, P2, P3 perforated sheet positions
Claims
Patent claims 1. Device (1) for measuring brake emissions (BE) with a housing (3) for accommodating a test object (2), in particular a brake assembly (2), wherein the housing (3) has a funnel-shaped supply area (7) through which cooling air (KL) from an air supply duct (4) can be introduced into the housing (3) through an inlet opening (9) for cooling the test object (2) and for detecting the brake emissions (BE), and wherein the brake emissions (BE) together with the cooling air from the housing (3) can be passed through an outlet opening (12) into an exhaust air duct (5) and to a measuring system, characterized in that at least one perforated plate (13) for flow rectification of the cooling air (KL) introduced into the housing (3) is arranged at a perforated plate position (P) in the funnel-shaped supply area (7), and that the perforated plate position (P) in the supply area (7) can be selected as desired. is.
2. Device (1) according to claim 1, characterized in that the at least one perforated plate (13) is provided with a filter mat (16).
3. Device (1) according to one of the preceding claims, characterized in that a diameter of the at least one perforated plate (13) is adapted to a cross section of the funnel-shaped supply line area (7) at the respectively selected perforated plate position (P).
4. Device (1) according to one of the preceding claims, characterized in that the at least one perforated plate (13) has a hole pattern with holes arranged in rows or offset in rows.
5. Device (1) according to one of claims 1 to 4, characterized in that the at least one perforated plate (13) has a hole pattern with holes arranged in concentric circles.
6. Device (1) according to one of the preceding claims, characterized in that in addition to the at least one perforated plate (13), a further perforated plate (14) is provided for the flow rectification of the cooling air (KL) in the funnel-shaped supply area (7), wherein the at least one perforated plate (13) and the further perforated plate (14) can each be arranged at two arbitrarily selectable perforated plate positions (P1, P2) in the supply area (7).
7. Device (1) according to one of claims 1 to 5, characterized in that at least three perforated plates (13, 14, 15) are provided for the flow rectification in the funnel-shaped supply line area, wherein the at least three perforated plates are any three perforated plate positions (P1, P2, P3) can be arranged in the supply line area.
8. Device (1) according to one of claims 1 to 5, characterized in that the at least one perforated plate (13) is designed such that, regardless of the respectively selected perforated plate position (P) at which the at least one perforated plate (13) is arranged in the supply line region (7), a ratio between a flow-through area of the at least one perforated plate (13) and a cross-sectional area of the supply line region (7) at the respectively selected perforated plate position (P) has a constant value.
9. Device (1) according to one of the preceding claims, characterized in that the housing (3) is hermetically sealed.
10. Device (1) according to one of the preceding claims, characterized in that the device (1) for measuring brake emissions (BE) can be combined with a dynamic brake test bench or integrated into a dynamic brake test bench.