Brake dust measuring device and brake dust measuring method

Abstract

A brake dust measurement device (100) for measuring brake dust generated from a brake (Z) is provided with: a chamber (10) that houses the brake (Z); a supply duct (11) that is connected to the chamber (10) and supplies gas through a supply port (O1) to the brake (Z); a discharge duct (12) that is connected to the chamber (10) and discharges, together with gas, brake dust flowing into a discharge port (O2); and a measurement mechanism that collects and measures the brake dust flowing through the discharge duct (12). The brake (Z) is disposed vertically below the supply port (O1), and the discharge port (O2) is disposed vertically below the brake (Z). The minimum diameter of the supply duct (11) is less than the maximum diameter of the chamber (10). A brake pad (Z1) constituting the brake (Z) is located within the supply port (O1) when viewed in the vertical direction.

Description

[Technical Field]

[0001] The present invention relates to a brake dust measuring device and a brake dust measuring method. [Background technology]

[0002] A conventional brake dust measuring device, as shown in Patent Document 1, operates a brake placed in a chamber while blowing air onto the brake, and collects the brake dust generated during the operation to measure, for example, its amount. By housing the brake in a chamber in this way, it is possible to reduce the background influence of airborne particles present in the vehicle interior.

[0003] Specifically, the device in Patent Document 1 has a blower installed on the side of the chamber, and this blower blows air into the chamber, but with a configuration that blows air from the side in this way, the brake dust can fall to the bottom of the chamber before mixing with the air, which can cause measurement errors. Also, because the blower needs to be installed near the side of the chamber, securing the installation space places restrictions on the installation location of the device.

[0004] In contrast to this, a device shown in Patent Document 2 is known as a device that sends air into a chamber from above.

[0005] However, even if air is sent from above in this way, if the airflow hitting the brakes becomes turbulent or the flow speed around the brakes becomes uneven, the generated brake dust will scatter around and remain in the chamber, making it impossible to accurately measure the total amount and concentration of brake dust emissions.In addition, in Patent Document 2, the main purpose of blowing air onto the brakes is to cool them, and no consideration is given to a specific configuration for blowing an unturbulent airflow onto the brakes. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2019-190901 [Patent Document 2] Special Publication No. 2020-520448 Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, the main object of the present invention is to suppress the loss of brake dust by allowing an undisturbed airflow to be applied to the brakes, thereby further reducing measurement errors and further improving measurement accuracy. [Means for solving the problem]

[0008] In other words, the brake dust measuring device of the present invention is a brake dust measuring device that measures brake dust generated from a brake, and is equipped with a chamber that accommodates the brake, a supply duct connected to the chamber and that supplies gas to the brake from a supply port, an exhaust duct connected to the chamber and that discharges brake dust flowing into an exhaust port together with the gas, and a measuring mechanism that collects and measures the brake dust flowing through the exhaust duct, wherein the brake is positioned vertically below the supply port and the exhaust port is positioned vertically below the brake, the minimum diameter of the supply duct is smaller than the maximum diameter of the chamber, and the brake pads that make up the brake are contained inside the supply port when viewed vertically.

[0009] With this brake dust measuring device, the supply port, brakes, and discharge port are arranged vertically, and the brake pads, which are the main source of brake dust, are located inside the supply port when viewed vertically. This makes it possible to make the flow velocity around the brakes uniform (constant), allowing the brakes to be hit by airflow that is as undisturbed as possible. This minimizes the loss of generated brake dust, further reducing measurement errors and improving measurement accuracy.

[0010] It is preferable that the supply port is 70% or more of the diameter of a brake disc that constitutes the brake. This allows the air to be blown over a wide area of the brake disc, more reliably preventing brake dust from remaining in the chamber.

[0011] The supply duct preferably has a tapered portion that gradually widens toward the supply port. With this configuration, undisturbed air can be applied to the brakes, which makes it difficult for brake dust to scatter within the chamber, and allows as much of the brake dust as possible to be expelled from the chamber.

[0012] A more specific embodiment is one in which the expansion angle of the tapered portion is less than 270°.

[0013] A more specific embodiment of the supply port is one in which the port has a circular or polygonal shape and the diameter of the port or the diameter of the circumscribed circle thereof is 300 mm or more. This allows the air to be blown over a wide range of brake discs, for example, for brakes of various sizes.

[0014] In order to make the measuring device adaptable to brakes of various sizes, it is preferable to provide an adapter that can change the size of the supply port. This allows the supply port to be changed to an optimum size depending on the size of the brake or the brake pads and brake discs that make up the brake.

[0015] More specifically, it is preferable that the adapter is capable of changing the diameter of the supply port within a range of 80 mm to 200 mm.

[0016] It is preferable that the height position of a shaft member of a brake disc constituting the brake is higher than the height position of the center of the chamber. In this case, the shaft member of the brake disc is closer to the supply port than the discharge port, so the wind can be directed at the brake pads and brake disc while maintaining its momentum, and as much brake dust as possible can be discharged from the chamber.

[0017] In order to more significantly exhibit the above-mentioned effects, it is preferable that the shaft member of the brake disc constituting the brake is located inside the supply port and the discharge port when viewed from the vertical direction.

[0018] It is preferable that the system comprises a main flow path through which sample gas containing the brake dust flows, a sampling flow path connected to a sampling point set in the main flow path and for collecting a portion of the sample gas, a main flow meter provided downstream of the sampling point in the main flow path, and a control device for controlling the sampling flow rate, which is the flow rate of the sampling flow path, so that the flow rate is proportional to the main flow rate, which is the flow rate of the main flow path, and that the downstream end of the sampling flow path is connected between the sampling point in the main flow path and the main flow meter, and that the sample gas collected in the sampling flow path is returned to the main flow path. With this configuration, the sampling flow rate is controlled so that it is proportional to the main flow rate, so even if the main flow rate is varied, it is possible to accurately measure the amount of brake dust, etc.

[0019] Another example of a configuration for making the sampling flow rate more accurately proportional to the main flow rate is one that includes a main flow path through which sample gas containing the brake dust flows, a sampling flow path connected to a sampling point set in the main flow path and for collecting a portion of the sample gas, a main flow meter provided downstream of the sampling point in the main flow path, a sampling flow meter provided in the sampling flow path, and a control device that controls the sampling flow rate, which is the flow rate of the sampling flow path, so that the flow rate is proportional to the main flow rate, which is the flow rate of the main flow path, and in which the measurement mechanism corrects the main flow rate measured by the main flow meter with the sampling flow rate measured by the sampling flow meter.

[0020] Furthermore, the brake dust measurement method of the present invention is a brake dust measurement method using a brake dust measurement device that measures brake dust generated from brakes, the brake dust measurement device comprising: a chamber that accommodates the brake; a supply duct connected to the chamber and supplying gas to the brake from a supply port; an exhaust duct connected to the chamber and exhausting brake dust flowing into an exhaust port together with the gas; and a measurement mechanism that collects and measures the brake dust flowing through the exhaust duct; the brake is positioned vertically below the supply port, and the exhaust port is positioned vertically below the brake; the minimum diameter of the supply duct is smaller than the maximum diameter of the chamber; brake pads that constitute the brake are positioned so that they fit inside the supply port when viewed vertically; and brake dust is measured using the measurement mechanism. According to this brake dust measuring method, it is possible to achieve the same effects as the above-mentioned brake dust measuring device. [Effects of the Invention]

[0021] According to the present invention configured in this way, the flow velocity around the brake becomes uniform, allowing the brake to be hit by airflow that is as undisturbed as possible, making it possible to reduce the loss of generated brake dust, thereby further reducing measurement error and further improving measurement accuracy. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a schematic diagram showing the overall configuration of a brake dust measuring device according to an embodiment of the present invention; [Figure 2] FIG. 2 is a schematic diagram showing the configuration of the chamber and its surroundings according to the embodiment; [Figure 3] FIG. 4 is a schematic diagram showing the positional relationship between the supply port of the supply duct and the brake pad in the embodiment; [Figure 4] FIG. 3 is a flowchart showing a brake dust measuring method according to the embodiment. [Figure 5] FIG. 10 is a schematic diagram showing the configuration of the periphery of a chamber in another embodiment. [Figure 6] FIG. 10 is a schematic diagram showing the configuration of the periphery of a chamber in another embodiment. [Figure 7] FIG. 10 is a schematic diagram showing the configuration of an adapter according to another embodiment. [Figure 8] FIG. 10 is a schematic diagram showing the overall configuration of a brake dust measuring device according to another embodiment. [Figure 9] FIG. 10 is a schematic diagram showing the overall configuration of a brake dust measuring device according to another embodiment. [Figure 10] FIG. 10 is a schematic diagram showing the overall configuration of a brake dust measuring device according to another embodiment. [Figure 11] FIG. 10 is a schematic diagram showing the overall configuration of a brake dust measuring device according to another embodiment. [Explanation of symbols]

[0023] 100 Brake dust measuring device Z brake Z1 Brake Pads Z2...Brake disc Z3...Shaft member 10 Chamber 11 Supply duct O1: Supply port 12 Exhaust duct O2...Exhaust port 20...Measuring mechanism D1: Diameter of supply port D2: Brake disc diameter 112 Tapered section θ: Spread angle DETAILED DESCRIPTION OF THE INVENTION

[0024] As shown in Figure 1, the brake dust measuring device 100 of this embodiment is intended to measure, for example, the amount of brake dust generated by operating a brake Z and test the performance of the brake Z, and is configured to operate by connecting the brake Z alone to a brake dynamo D. The brake dust measuring device 100 may be a device for testing the performance of the brakes Z of a test vehicle, which is a completed vehicle, by running the test vehicle on a chassis dynamometer.

[0025] Specifically, as shown in Figure 1, this brake dust measuring device 100 comprises a chamber 10 that houses a test specimen, a brake Z, connected to a brake dynamo D, a supply flow path L1 that supplies gas to the brake Z operating within the chamber 10, a main flow path L2 through which brake dust generated from the brake Z flows along with the gas, and a measurement mechanism 20 that collects and measures the brake dust flowing through the main flow path L2.

[0026] The chamber 10 has an internal space formed as a housing space 10s for housing the brake Z, and is, for example, cylindrical.

[0027] As shown in FIGS. 1 and 2, the supply flow path L1 is formed by a supply duct 11 connected to a portion of the upper wall (wall surface) of the chamber 10. The supply duct 11 has a supply port O1 communicating with the interior of the chamber 10, and supplies a gas, such as air, into the chamber 10 through the supply port O1. The minimum diameter of the supply duct 11 is smaller than the maximum diameter of the chamber 10. Specifically, the supply duct 11 is a pipe that is narrower than the diameter of the accommodation space 10s of the chamber 10 (i.e., the inner diameter of the chamber 10). In other words, the minimum diameter of the supply duct 11 as viewed vertically is smaller than the maximum diameter of the chamber 10 as viewed vertically. This allows the supplied air to hit the brake Z during operation. Note that the gas hitting the brake Z is not necessarily limited to air and may be changed as appropriate. Furthermore, as shown in FIG. 1, the supply flow path L1 may be provided with one or more straightening plates X1 for straightening the air, for example, at bends.

[0028] 1 and 2, the main flow path L2 is formed by an exhaust duct 12 connected to the bottom wall of the chamber 10. This exhaust duct 12 has an exhaust port O2 that communicates with the inside of the chamber 10, and exhausts brake dust that flows into this exhaust port O2 together with air from the chamber 10. As a result, the exhausted air containing brake dust flows through the main flow path L2 as sample gas. Furthermore, the main flow path L2 may be provided with one or more straightening plates X2 for straightening the sample gas, for example, at bends, as shown in FIG.

[0029] The measurement mechanism 20 collects a portion of the sample gas flowing through the main flow path L2 and measures the brake dust contained in the collected sample gas.Specifically, it comprises a sampling flow path L3 that collects a portion of the sample gas from the main flow path L2, and a collection filter F that is provided in the sampling flow path L3 and serves as a collection unit that collects brake dust in the sample gas.

[0030] The measurement mechanism 20 of this embodiment is configured to proportionally sample the sample gas. Specifically, the measurement mechanism 20 includes a main flow rate adjuster P1 for adjusting the flow rate of the sample gas drawn from the chamber 10 into the main flow path L2 (hereinafter referred to as the main flow rate), and a sampling flow rate adjuster P2 for adjusting the flow rate of the sample gas drawn from the main flow path L2 into the sampling flow path L3 (hereinafter referred to as the sampling flow rate). Examples of the main flow rate adjuster P1 and the sampling flow rate adjuster P2 include a blower, a pump, and a mass flow controller.

[0031] The measurement mechanism 20 is configured to control, for example, the rotation speed of the sampling pump serving as the sampling flow rate adjuster P2 so that the ratio of the sampling flow rate to the main flow rate becomes a predetermined split flow ratio. Note that the main flow rate and the sampling flow rate here are mass flow rates.

[0032] With the above-described configuration, the amount of brake dust collected on the collection filter F can be obtained, for example, by subtracting the weight of the collection filter F before collection from the weight of the collection filter F after collection. The measurement mechanism 20 may also function as a brake dust amount calculation unit that calculates the total amount of brake dust by multiplying this brake dust amount by the split flow ratio between the main flow rate and the sampling flow rate.

[0033] As shown in Figures 2 and 3, in the brake dust measuring device 100 of this embodiment, the supply port O1 of the supply duct 11, the brake Z in the chamber 10, and the discharge port O2 of the discharge duct 12 are arranged vertically.

[0034] 2, in this brake dust measuring device 100, the brake Z is disposed vertically below the supply port O1, and the discharge port O2 is disposed vertically below the brake Z. In other words, the supply port O1 and the discharge port O2 are disposed opposite each other in the vertical direction, and the brake Z is held between the supply port O1 and the discharge port O2.

[0035] As shown in FIG. 3, the brake dust measuring device 100 here is equipped with a brake Z and a mounting jig 30 that holds the brake Z in the chamber 10 vertically below the supply port O1.

[0036] 3, the brake pad Z1 constituting the brake Z is arranged so as to be located inside the supply port O1 when viewed vertically, and here, each of the pair of brake pads Z1 is arranged so as to be located inside both the supply port O1 and the discharge port O2 when viewed vertically. Note that, although this embodiment shows an aspect in which the discharge port O2 is larger than the supply port O1, the discharge port O2 may be smaller than the supply port O1, or the supply port O1 and the discharge port O2 may be of equal size.

[0037] In this arrangement, as shown in Fig. 2, the height position Zh of the shaft member Z3 of the brake disc Z2 constituting the brake Z is higher than the height position 10h of the center of the chamber 10. That is, the mounting jig 30 of this embodiment holds the brake Z so that the height position Zh of the shaft member Z3 of the brake disc Z2 is higher than the height position 10h of the center of the chamber 10. In this arrangement, the shaft member Z3 of the brake disc Z2 is located inside the supply port O1 and the discharge port O2 when viewed vertically, as shown in Fig. 3. However, the shaft member Z3 of the brake disc Z2 does not necessarily have to be higher than the height position 10h of the center of the chamber 10, and may be located below this height position 10h.

[0038] In this embodiment, the supply duct 11 is cylindrical, and the supply port O1 is circular. As shown in Fig. 2, the diameter D1 of the supply port O1 is 70% or more of the diameter D2 of the brake disc Z2, and is larger than the diameter D2 of the brake disc Z2, specifically, 300 mm or more.

[0039] 2, the supply duct 11 of this embodiment has a tapered downstream end that gradually widens toward the supply port O1. Specifically, the supply duct 11 of this embodiment includes a straight pipe section 111 extending vertically and a tapered section 112 that gradually widens from the straight pipe section 111 toward the supply port O1. The tapered section 112 has an expansion angle θ of less than 270°. The expansion angle here refers to the angle between the inner circumferential surface 111a of the straight pipe section 111 and the inner circumferential surface 112a of the tapered section 112.

[0040] Next, a brake dust measuring method using the brake dust measuring device 100 of this embodiment will be described with reference to the flowchart in FIG.

[0041] First, the brake Z is placed in the chamber 10. Specifically, the brake Z is attached to the attachment jig 30, and the brake pad Z1 constituting the brake Z is placed so that the entire brake pad Z1 is located inside the supply port O1 when viewed vertically (S1). At this time, in this embodiment, the entire brake pad Z1 is also located so that the entire brake pad Z1 is located inside the discharge port O2 when viewed vertically. Also, in this embodiment, the shaft member Z3 of the brake disc Z2 is located so that it is located inside the supply port O1 and the discharge port O2 when viewed vertically.

[0042] Next, while operating the brake Z in the chamber 10, air is supplied to the brake Z from the supply flow path L1, and the main flow rate adjustment unit P1 is operated, thereby causing the sample gas containing brake dust generated from the brake Z to flow into the main flow path L2 (S2).

[0043] Then, a portion of the sample gas flowing through the main flow path L2 is collected in the sampling flow path L3 (S3), whereby brake dust contained in the sample gas is collected by the collection filter F.

[0044] Thereafter, for example, the amount of brake dust collected by the collection filter F and, from that amount of brake dust, the total mass of brake dust in one test or the mass of brake dust per unit travel distance are calculated (S4).

[0045] With the brake dust measuring device 100 configured in this manner, the supply port O1 of the supply duct 11, the brake Z, and the discharge port O2 of the discharge duct 12 are arranged vertically, and the brake pad Z1, which is the main source of brake dust, is located inside the supply port O1 when viewed vertically, so the flow velocity around the brake Z can be made uniform (constant), and an airflow with as little turbulence as possible can be directed at the brake Z. This makes it possible to limit the loss of generated brake dust, reduce measurement errors, and improve measurement accuracy. Furthermore, the above-described arrangement allows as much of the generated brake dust as possible to be guided to the outlet O2 without remaining in the chamber 10, thereby further reducing measurement errors and further improving measurement accuracy.

[0046] Furthermore, since the diameter D1 of the supply port O1 is 70% or more of the diameter D2 of the brake disc Z2 that constitutes the brake Z, the air can be blown over a wide area of the brake disc Z2, which more reliably prevents brake dust from remaining in the chamber 10.

[0047] Furthermore, the supply duct 11 has a tapered section 112 that gradually widens toward the supply port O1, so that undisturbed air can be directed at the brakes Z. This makes it difficult for brake dust to scatter within the chamber 10, and it is possible to discharge as much of the brake dust as possible from the chamber 10.

[0048] Furthermore, since the height position Zh of the shaft member Z3 of the brake disc Z2 constituting the brake Z is higher than the height position 10h of the center of the chamber 10, the shaft member D3 of the brake disc Z2 is closer to the supply port O1 than to the discharge port O2, and the wind can be directed at the brake pad Z1 and the brake disc Z2 while maintaining its momentum, and as much brake dust as possible can be discharged from the chamber 10.

[0049] The present invention is not limited to the above-described embodiment.

[0050] For example, although the supply duct 11 in the above embodiment was connected to the upper wall of the chamber 10, as shown in FIG. 5, the supply duct 11 may pass through the upper wall of the chamber 10 and the supply port O1 may be located inside the chamber 10.

[0051] Furthermore, in the supply duct 11 of the above embodiment, the tapered section 112, whose downstream end is tapered, extends toward the supply port O1. However, as shown in FIG. 6, the supply duct 11 does not necessarily have to have the tapered section 112, and the straight pipe section 111 may extend to the supply port O1.

[0052] Furthermore, in the above embodiment, not only the brake pad Z1 but also the shaft member Z3 of the brake disc Z2 were arranged so as to fit inside the supply port O1 when viewed from the vertical direction, but in the brake dust measuring device 100 according to the present invention, as shown in FIG. 6, it is sufficient that at least the brake pad Z1 is arranged so as to fit inside the supply port O1 when viewed from the vertical direction.

[0053] 7, the brake dust measuring device 100 may also be provided with a plurality of adapters 113 that can change the size of the supply port O1. Specifically, these adapters 113 constitute the supply duct 11 and are detachable from, for example, the straight pipe portion 111. Examples of such adapters include those that can change the diameter of the supply port O1 within a range of 80 mm to 200 mm. With this configuration, the supply port O1 can be changed to an optimum size depending on the size of the brake Z or the brake pad Z1, brake disc Z2, etc. that constitute the brake Z.

[0054] Furthermore, in the above embodiment, the supply duct 11 is cylindrical and the supply port O1 is circular, but the supply duct 11 may be cylindrical and have a polygonal cross section, such as a square. In this case, the supply port O1 may also be polygonal, and the diameter of its circumscribing circle may be 300 mm or more.

[0055] Furthermore, in the above embodiment, a brief description was given of the manner in which the measurement mechanism 20 proportionally samples the sample gas. However, to explain this configuration in more detail, the brake dust measurement device 100 may further include a main flow meter FM1 provided in the main flow path L2 and a sampling flow meter FM2 provided in the sampling flow path L3, as shown in FIG. 8.

[0056] In FIG. 8, the main flow meter FM1 is provided downstream of the sampling point X, which is the connection point of the main flow path L1 to the sampling flow path L2, but it may also be provided upstream of the sampling point X. Furthermore, although the sampling flow meter FM2 is provided downstream of the filter F in FIG. 8, it may be provided upstream of the filter F.

[0057] As shown in FIG. 8, this brake dust measuring device 100 may also be equipped with a control device C that controls one or both of the main flow rate adjustment unit P1 and the sampling flow rate adjustment unit P2 so that the sampling flow rate measured by the sampling flow meter FM2 is a flow rate proportional to the main flow rate measured by the main flow meter FM1. That is, in this brake dust measuring device 100, the control device C sets the flow rate of the main flow path L2 and the sampling flow rate, which is the flow rate of the sampling flow path L3, so that the flow rate is proportional to the main flow rate, which is the flow rate of the main flow path L2.

[0058] With this configuration, the sampling flow rate is controlled so that it is proportional to the main flow rate, so even if the main flow rate is varied, it is possible to accurately measure the amount of brake dust, etc.

[0059] Furthermore, as shown in Figure 9, the brake dust measuring device 100 of the present invention may be configured such that the downstream end of the sampling flow path L3 is connected downstream of the sampling point in the main flow path L2, and the sample gas collected in the sampling flow path L3 is returned to the main flow path L2. In this case, the flow rate of the collected sample gas after it is returned to the main flow path L2 can be measured as the main flow rate, so that the sampling flow rate can be made more accurately proportional to the main flow rate.

[0060] Another example of a method for making the sampling flow rate more accurately proportional to the main flow rate is to have the control device 20C correct the main flow rate measured by the main flow meter FM1 with the sampling flow rate measured by the sampling flow meter FM2. Specifically, the flow control unit 21 may be configured to add the sampling flow rate measured by the sampling flow meter FM2 to the main flow rate measured by the main flow meter FM1, and control one or both of the main flow rate adjustment unit P1 and the sampling flow rate adjustment unit P2 based on the flow rate after the addition.

[0061] The brake dust measuring device 100 may also be equipped with a sampling bag for collecting sample gas instead of or in addition to the collection filter F, and measure various components contained in the collected sample gas. Note that components to be measured may include components such as hydrocarbons derived from brake dust and / or components contained in exhaust gas. In this case, the sampling bag SB may be provided, for example, downstream of the sampling flow rate adjuster P2, or may be provided in a second sampling flow path L4 separate from the sampling flow path L3, as shown in Fig. 10. In the configuration shown in Fig. 10, the second sampling flow path L4 may be provided with a sampling pump P3 or the like, which serves as a second sampling flow rate adjuster. The sampling point of the second sampling flow path L4 may be upstream or downstream of the sampling point of the sampling flow path L3. In such a configuration in which the sampling bag SB is provided, the measurement of the sample gas collected in the sampling bag and the measurement of the brake dust may be carried out simultaneously or separately.

[0062] Furthermore, the brake dust measuring device 100 according to the present invention may be configured so that air flows laterally (or approximately horizontally) within the chamber 10, as shown in FIG. 11, or may be configured so that air flows obliquely within the chamber 10 in a direction inclined relative to either the horizontal or vertical directions, as not shown. A specific embodiment is one in which an air supply port O1 and an air exhaust port O2 are provided on the circumferential side surface of the chamber 10. The supply port O1 and the air exhaust port O2 may be arranged to face each other, or may not face each other.

[0063] Furthermore, in the above embodiment, a brake dust amount calculation unit that calculates the amount of brake dust collected on the collection filter F has been described, but instead of or in addition to the collection filter F, a DCS (Diffusion Changer Sensor) that functions as a dust collection unit and analysis unit may be installed in the sampling flow path L3, so that collection and analysis of brake dust are performed simultaneously, for example. Similarly, instead of or in addition to the collection filter F, a PN (Particle Number) measuring device may be installed in the sampling flow path L3 so as to function as a dust collection unit and analysis unit. The concept including at least one of the collection filter F, brake dust amount calculation unit, exhaust gas analyzer, DCS, and PN measuring instrument may be called the brake dust analysis unit.

[0064] Furthermore, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications are possible without departing from the spirit of the present invention. [Industrial Applicability]

[0065] According to the present invention configured in this way, the flow velocity around the brake becomes uniform, allowing the brake to be hit by airflow that is as undisturbed as possible, making it possible to reduce the loss of generated brake dust, thereby further reducing measurement error and further improving measurement accuracy.

Claims

1. A brake dust measuring device for measuring brake dust generated from brakes, a chamber containing the brake; a supply duct connected to the chamber for supplying gas to the brake through a supply port; an exhaust duct connected to the chamber for exhausting brake dust flowing into an exhaust port together with the gas; a measuring mechanism for collecting and measuring brake dust flowing through the exhaust duct, The brake is disposed vertically below the supply port, and the discharge port is disposed vertically below the brake, the minimum diameter of the supply duct is smaller than the maximum diameter of the chamber; A brake dust measuring device, wherein a brake pad constituting the brake is accommodated inside the supply port when viewed vertically.

2. 2. The brake dust measuring device according to claim 1, wherein the supply port is 70% or more of the diameter of a brake disc constituting the brake.

3. 3. The brake dust measuring device according to claim 1, wherein the supply duct has a tapered portion that gradually widens toward the supply port.

4. 4. The brake dust measuring device according to claim 3, wherein the tapered portion has an expansion angle of less than 270 degrees.

5. 5. The brake dust measuring device according to claim 1, wherein the supply port is circular or polygonal, and the diameter of the supply port or the diameter of the circumscribed circle of the supply port is 300 mm or more.

6. 6. The brake dust measuring device according to claim 1, further comprising an adapter that can change the size of the supply port.

7. 7. The brake dust measuring device according to claim 6, wherein the adapter is capable of changing the diameter of the supply port within a range of 80 mm to 200 mm.

8. 8. The brake dust measuring device according to claim 1, wherein a height position of a shaft member of a brake disc constituting the brake is higher than a height position of a center of the chamber.

9. 9. The brake dust measuring device according to claim 1, wherein a shaft member of a brake disc constituting the brake is accommodated inside the supply port and the discharge port when viewed in the vertical direction.

10. a main flow path through which the sample gas containing the brake dust flows; a sampling flow path connected to a sampling point set in the main flow path and configured to collect a portion of the sample gas; a main flow meter provided downstream of the sampling point in the main flow path; a control device for controlling a sampling flow rate, which is a flow rate of the sampling flow path, so that the flow rate is proportional to a main flow rate, which is a flow rate of the main flow path; A brake dust measuring device as described in any one of claims 1 to 9, wherein the downstream end of the sampling flow path is connected between the sampling point in the main flow path and the main flow meter, and is configured to return the sample gas collected in the sampling flow path to the main flow path.

11. a main flow path through which the sample gas containing the brake dust flows; a sampling flow path connected to a sampling point set in the main flow path and configured to collect a portion of the sample gas; a main flow meter provided downstream of the sampling point in the main flow path; a sampling flow meter provided in the sampling flow path; a control device for controlling a sampling flow rate, which is a flow rate of the sampling flow path, so that the flow rate is proportional to a main flow rate, which is a flow rate of the main flow path; 10. The brake dust measuring device according to claim 1, wherein the measuring mechanism corrects the main flow rate measured by the main flow meter using the sampling flow rate measured by the sampling flow meter.

12. A brake dust measurement method using a brake dust measurement device that measures brake dust generated from brakes, The brake dust measuring device is a chamber containing the brake; a supply duct connected to the chamber for supplying gas to the brake through a supply port; an exhaust duct connected to the chamber for exhausting brake dust flowing into an exhaust port together with the gas; a measuring mechanism for collecting and measuring brake dust flowing through the exhaust duct, The brake is disposed vertically below the supply port, and the discharge port is disposed vertically below the brake, the minimum diameter of the supply duct is smaller than the maximum diameter of the chamber; a brake pad constituting the brake is disposed so as to be accommodated inside the supply port when viewed in a vertical direction; A brake dust measuring method, wherein brake dust is measured by the measuring mechanism.

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