Method for estimating wear amount of friction material and wear amount estimation device therefor

Abstract

To provide a method for estimating a wear amount of a friction material that can accurately estimate an amount of wear of a friction material in a certain brake and a wear amount estimation device for the same.SOLUTION: A wear amount estimation method #100 is a method for estimating a wear amount of a friction material which makes frictional contact, and includes a friction amount estimation step #190 of estimating the wear amount of the friction material on the basis of an amplitude of an output signal output by a detection device which detects an elastic wave emitted by the friction material. The wear amount estimation step #190 estimates the wear amount of the friction material on the basis of a relational expression representing a relation between a time integration value of the maximum amplitude of the output signal output by the detection device and the wear amount of the friction material. The wear amount estimation step #190 includes a step of estimating the wear amount of the friction material from a braking start time to a breaking stop time when a certain braking force is applied. The wear amount estimation step #190 includes a step of estimating the wear amount of the friction material at a certain time from the braking start time to the braking stop time when the certain brake force is applied.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a method and an apparatus for estimating the amount of wear of a friction material that is in frictional contact with another friction material. [Background technology]

[0002] The Acoustic Emission (AE) method is known, which utilizes the phenomenon in which elastic energy stored inside an object or material is released as an elastic wave when it deforms or breaks. Academically, it is said that the amplitude of the AE signal is related to frictional force, and the energy of the AE signal is related to wear. An example of its application is often the detection of signs of failure in steady-state phenomena (rated rotation, rated time) such as bearings.

[0003] A conventional wear detection device 106 shown in FIG. 17 (hereinafter referred to as Prior Art 1) comprises an AE sensor 106a that detects acoustic emissions generated from friction-welded parts and outputs an AE signal, a preamplifier 106b that amplifies the output signal of the AE sensor 106a, a filter processing circuit 106c that removes noise components from the output signal of the preamplifier 106b, a main amplifier 106d that amplifies the output signal of the filter processing circuit 106c, an envelope detection circuit 106e that performs envelope detection on the output signal of the main amplifier 106d and outputs a characteristic curve of the AE signal, and a time integration circuit 106b that integrates the characteristic curve of the AE signal output by the envelope detection circuit 106e to detect the voltage of the AE signal that affects wear. The friction-welded component includes an energy calculation circuit 106f that calculates the AE energy by integrating the pressure over time, a differential / integral circuit 106g that calculates the integrated amount of AE energy according to the usage time of the friction-welded component and calculates the change in AE energy over time, a reference value (threshold) setting circuit 106h that sets first and second reference values, a comparison circuit 106i that compares the integrated amount of AE energy with the first reference value to determine the appropriate time for replacement or inspection of the friction-welded component and compares the change in AE energy over time with the second reference value to determine whether there is a sudden abnormality or a sign of such an abnormality in the friction-welded component, and a display circuit 106j that displays the results of the determination by the comparison circuit 106i (see, for example, Patent Document 1). This prior art 1 estimates the wear state of the friction-welded component based on the integrated amount of AE energy over time and the change in AE energy over time, and determines whether there is a sudden abnormality or a sign of such an abnormality in the friction-welded component.

[0004] On the other hand, braking is a complex, unsteady phenomenon, and few examples have been reported, often at the small test specimen level. Evaluation of the frictional properties of automotive brake materials using acoustic emission measurements (hereinafter referred to as Prior Art 2) involves a pin-on-disc wear tester that brings a pin test specimen made of cast iron (FC250) rotor material into frictional contact with a block test specimen of a simple-compound brake pad material. The AE signal is measured from a broadband AE sensor on the brake pad material, and frictional force is measured using a strain gauge attached to the leaf spring that secures the pin test specimen (see, for example, Non-Patent Document 1). Prior Art 2 demonstrates the potential for evaluating the frictional properties of brake pad materials using AE measurements, demonstrating the feasibility of using AE measurements to evaluate the frictional properties of brake pad materials, regardless of the type of brake pad material.

[0005] In the experimental evaluation of railway vehicle brake shoes using the AE method (Second Report) (hereinafter referred to as Prior Art 3), brake shoe specimens with different braking performance were brought into contact with the wheels of a conventional railway vehicle using a full-scale bench testing machine, and AE waves were detected by an AE sensor on the brake shoe side (see, for example, Non-Patent Document 2). Prior Art 3 showed that there is a certain degree of correlation between the maximum energy of the AE signal and the amount of wear. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-003299

[0007] [Non-Patent Document 1] Alan Hase and four others, "Evaluation of Friction Properties of Automotive Brake Materials by Acoustic Emission Measurement," Proceedings of the 25th Transportation and Logistics Conference (TRANSLOG2016), Japan Society of Mechanical Engineers, Tokyo, November 30-December 2, 2016, 1214

[0008] [Non-patent document 2] Shinichi Saga et al., "Experimental Evaluation of Railway Vehicle Brake Shoes Using AE Method (2nd Report)", 29th Railway Technology Joint Symposium (J-RAIL2022), Institute of Electrical Engineers of Japan, Tokyo, December 7-9, 2022, pp. 436-439 Summary of the Invention [Problem to be solved by the invention]

[0009] In Prior Art 1, a comparison circuit compares the reference value set by a reference value setting circuit with the cumulative amount of AE energy over time to determine the degree of wear of the wear-welded parts, as well as any sudden abnormalities or signs thereof. Therefore, Prior Art 1 requires a reference value (threshold value) in the reference determination circuit, which has the problem that only qualitative evaluations are possible. Prior Art 2 has the problem that AE measurements can only be used to qualitatively evaluate the friction characteristics of brake pad materials using small test pieces. Prior Art 3 uses a full-size brake shoe for testing, but is unable to quantify the amount of wear, and has the problem that only qualitative evaluations can be made using the AE method.

[0010] The amount of wear on brake materials is determined by conducting a considerable number of tests (several hundred times) using bench testing equipment and determining the difference in mass lost due to wear. The amount of wear obtained in this way is a result-based measurement, not a time-based evaluation. In other words, it is not possible to evaluate the amount of wear instantaneously (in real time). Another method is to collect the wear debris emitted from the friction material, but this is difficult due to constraints on the brake device shape and the influence of factors such as wind while driving. Another method is to visualize the wear debris and count it using image analysis, but in addition to the reasons mentioned above, this is difficult due to factors such as the influence of gas generated by temperature increases.

[0011] An object of the present invention is to provide a method and device for estimating the amount of wear of a friction material, which can estimate the amount of wear of a friction material in any brake with high accuracy. [Means for solving the problem]

[0012] The present invention solves the above problems by the means described below. Although the description will be given with reference numerals corresponding to the embodiments of the present invention, the present invention is not limited to these embodiments. The invention of claim 1 is a method for estimating the amount of wear of a friction material (4) that is in frictional contact, as shown in Figures 1 to 4, 7, and 9 to 11, in which the amount of wear of the friction material (4) is estimated based on the amplitude of an output signal output from a detection device (6; 6A, 6B) that detects elastic waves emitted by the friction material. f ,W ft The method (#100) for estimating the amount of wear of a friction material is characterized by including a wear amount estimation step (#190;#240) for estimating the amount of wear of the friction material.

[0013] The invention of claim 2 is the method for estimating the amount of wear of a friction material according to claim 1, wherein, as shown in FIG. 6, the wear amount estimation step uses a relational expression (R f ,R ft The method for estimating the amount of wear of a friction material is characterized by including a step of estimating the amount of wear of the friction material based on the measured value of the friction material.

[0014] The invention of claim 3 is the method of estimating the amount of wear of a friction material according to claim 1, wherein, as shown in FIG. 6, the wear amount estimation step estimates the amount of wear from a braking start time (t0) to a braking stop time (t e The method for estimating the amount of wear of the friction material is characterized by comprising a step of estimating the amount of wear of the friction material up to the point where the friction material reaches a predetermined value.

[0015] The invention of claim 4 is the method for estimating the amount of wear of a friction material according to claim 1, characterized in that, as shown in FIG. 6, the wear amount estimation step includes a step of estimating the amount of wear of the friction material at a certain time (t) between the braking start time and the braking stop time when an arbitrary braking force is applied.

[0016] The invention of claim 5 is the method for estimating the wear amount of a friction material according to claim 1, The wear amount estimation step is performed by calculating an exponential approximation formula (R f ,R ft The method for estimating the amount of wear of a friction material when an arbitrary braking force is applied is characterized by including a step of estimating the amount of wear of the friction material when an arbitrary braking force is applied based on the amount of wear of the friction material.

[0017] The invention of claim 6 is the method for estimating the amount of wear of a friction material according to claim 5, wherein the wear amount estimation step is carried out by calculating a pressing force (P e ) when any braking force is applied to i ) and the speed (v e ) when applying any braking force to the speed (v i ) and the initial velocity ratio (d), the exponential coefficients (n1 to n4) of these ratios, and the exponential approximation formula (R f ,R ft ) and the wear amount of this friction material (W f ,W ft The method for estimating the wear amount of a friction material is characterized by including a step of estimating the wear amount of the friction material.

[0018] The invention of claim 7 is a method for estimating the amount of wear of a friction material as described in claim 1, characterized in that, as shown in Figures 3, 4 and 7, the wear amount estimation process estimates the amount of wear of a brake shoe (4) of a brake device (3) on a test stand (1A) based on the amplitude of an output signal output by a detection device (6) that detects elastic waves emitted by the brake shoe (4).

[0019] The invention of claim 8 is a method for estimating the amount of wear of a friction material as described in claim 1, characterized in that, as shown in Figures 9 to 11, the wear amount estimation process estimates the amount of wear of a brake shoe (4) based on the amplitude of an output signal output by a detection device (6B) that detects elastic waves emitted by the brake shoe (4) of a brake device (3B) of an actual vehicle (1B).

[0020] The invention of claim 9 is a friction material wear amount estimation device (7; 7B) that estimates the amount of wear of a friction material (4) that is in frictional contact, as shown in Figures 1 to 4, 8 to 10 and 12, and is characterized in that it includes a wear amount estimation unit (13) that estimates (S170; S270) the amount of wear of the friction material based on the amplitude of an output signal output by a detection device (6; 6A, 6B) that detects elastic waves emitted by the friction material. [Effects of the Invention]

[0021] According to the present invention, the amount of wear of the friction material of any brake can be estimated with high accuracy. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a side view that schematically shows a brake device that includes a brake shoe whose wear amount is estimated by a friction material wear amount estimating device according to a first embodiment of the present invention. [Figure 2] 1 is a plan view schematically showing a brake device in which a friction material wear amount estimation device according to a first embodiment of the present invention is used. [Figure 3] 1 is a block diagram of a friction material wear amount estimation system according to a first embodiment of the present invention. [Figure 4] 1 is a schematic diagram for explaining a process of estimating the wear amount of a friction material by the friction material wear amount estimation system according to the first embodiment of the present invention. FIG. [Figure 5]FIG. 1 is a graph schematically showing a relational expression generated by a relational expression generating unit in the friction material wear amount estimation device according to the first embodiment of the present invention when a maximum braking force is applied, and a graph showing a relational expression when calculating the amount of wear from the start of braking to the stop of braking when the maximum braking force is applied. [Figure 6] FIG. 1 is a graph schematically showing a relational expression generated by a relational expression correction unit in the friction material wear amount estimation device according to the first embodiment of the present invention when an arbitrary braking force is applied, and FIG. 2 is a graph showing a relational expression when estimating the amount of wear from the start of braking to the stop of braking when an arbitrary braking force is applied. [Figure 7] FIG. 1 is a process diagram of a wear amount estimation method according to a first embodiment of the present invention. [Figure 8] 4 is a flowchart for explaining the operation of the device for estimating a wear amount of a friction material according to the first embodiment of the present invention. [Figure 9] FIG. 5 is a block diagram of a friction material wear amount estimation system according to a second embodiment of the present invention. [Figure 10] FIG. 6 is a schematic diagram for explaining the process of estimating the wear amount of a brake shoe by the friction material wear amount estimation system according to the second embodiment of the present invention. [Figure 11] FIG. 6 is a process diagram of a wear amount estimation method according to a second embodiment of the present invention. [Figure 12] 6 is a flowchart for explaining the operation of the device for measuring the amount of wear of a friction material according to the second embodiment of the present invention. [Figure 13] 1 shows the measurement results of the amount of brake shoe wear when the emergency brake was applied once in a bench test, where (A) is a graph showing an example of an exponential approximation formula that expresses the relationship between the time integral value of the maximum amplitude of the AE signal and the amount of wear in an example, and (B) is a graph of a general exponential approximation formula that shows the relationship between the initial braking speed and the amount of wear in a comparative example. [Figure 14]1 shows the measurement results of the amount of brake shoe wear when the service brake 7 notch was applied once in a bench test, where (A) is a graph showing an example of an exponential approximation formula that expresses the relationship between the time integral value of the maximum amplitude of the AE signal and the amount of wear in an example, and (B) is a graph of a general exponential approximation formula that shows the relationship between the initial brake speed and the amount of wear in a comparative example. [Figure 15] This is a graph comparing the ratio of estimated results of brake shoe wear amount when the normal brake notch is 7 in a bench test at five different initial braking speeds (35, 50, 65, 80, 95 km / h). [Figure 16] 10 is a graph showing an example of an estimated result of brake shoe wear amount. [Figure 17] FIG. 1 is a configuration diagram of a conventional wear detection device. DETAILED DESCRIPTION OF THE INVENTION

[0023] (First embodiment) A first embodiment of the present invention will be described in detail below with reference to the drawings. The test stand 1A shown in FIG. 3 is a device for testing actual equipment. The test stand 1A is a comprehensive testing device, such as a brake performance testing machine, that performs tests to evaluate various brake-related performance characteristics. The test stand 1A performs a bench test (test stand test) of a brake device 3 alone to confirm the function or performance of the brake device 3. The test stand 1A includes, for example, a disc brake test unit that evaluates the performance of disc brakes mounted on a vehicle, and a tread brake test unit that evaluates the performance of tread brakes. The test stand 1A shown in FIG. 3 tests brake devices used in conventional vehicles and Shinkansen (Bullet Train) vehicles. The test stand 1A can control brake pressing force, deceleration, torque, etc. under a wide range of conditions, from locomotives to commuter trains and Shinkansen equivalents, allowing for tests equivalent to those in actual running.

[0024] The wheel 2 shown in FIGS. 1 and 2 is a member that comes into rolling contact with a rail. As shown in FIG. 2, the wheel 2 has a tread surface 2a that comes into contact with the top surface of the rail and receives frictional resistance, and a flange surface 2b that is formed continuously on the outer periphery of the wheel 2 to prevent the wheel from coming off. The wheel 2 is a component of a wheelset that supports a railway vehicle and is an actual wheel used on the railway vehicle. The wheel 2 may be an integrally rolled wheel in which the tire and wheel core are integrated by rolling high-carbon steel, or a tire-and-wheel in which the tire is shrink-fitted onto the wheel core. Here, examples of integrally rolled wheels include AR (as rolled) wheels that are not subjected to heat treatment, SQ (slack quenched) wheels used for electric trains or diesel railcars and in which the surface area has a fine pearlite structure that makes it less susceptible to thermal cracking, and RQ (rim quenched) wheels used for electric trains or Shinkansen (registered trademark) trains and in which the surface area has a tempered martensite structure that increases strength. The wheel with tire is, for example, a rolled wheel core made of high carbon steel, or a cast steel wheel made of cast steel, etc. The wheel 2 is attached to a test stand 1A.

[0025] The brake device 3 shown in Figures 1 and 2 is a device for applying brakes. The brake device 3 is a basic brake device that operates mechanically via a lever mechanism or the like by flowing air or hydraulic pressure specified by a brake control device into a brake cylinder, pressing a friction material and generating frictional force. The brake device 3 is a tread brake device that presses a brake shoe 4 against the tread 2a of a wheel 2 to generate frictional force as braking force. The brake device 3 shown in Figures 1 and 2 is, for example, a unit brake in which each component is unitized, and is a one-sided brake brake that presses the brake shoe 4 against the tread 2a of the wheel 2 from one side of the wheel 2. The brake shoe 4 is detachably attached to the brake device 3 so that tests can be performed by replacing it with multiple types of brake shoes 4 made of different materials. The brake device 3 is installed on a dedicated test stand 1A. When installed on the test stand 1A, the brake device 3 generates a pressing force (constant value) determined for each brake notch. Here, the brake notch refers to a number of stages (notches) set according to the braking force to be generated, and any stage can be selected by operating the operation unit of the test stand 1A. The brake notch is set, for example, in a total of eight stages, including stages 1 to 7 for normal use and one for emergency use, and the magnitude of the braking force differs depending on the stage, and the deceleration (negative acceleration), which is the rate of decrease in speed during braking, differs depending on the magnitude of the braking force.

[0026] The brake shoe 4 shown in Figures 1 to 3 is a friction material that generates frictional force when pressed against the tread 2a of the wheel 2. As shown in Figure 1, the brake shoe 4 is a brake friction material (shoe) that has an arc-shaped appearance, and the back surface of this brake shoe 4 is held by a brake shoe head (mounting portion (shoe head)). The brake shoe 4 has a friction surface (lining surface) 4a that comes into frictional contact with the tread 2a. As shown by the solid lines in Figures 1 and 2, the brake shoe 4 advances toward and is pressed against the tread 2a of the wheel 2 when the brake is applied. As shown by the two-dot chain lines in Figures 1 and 2, the brake shoe 4 retracts from and separates from the tread 2a of the wheel 2 when the brake is released. Brake shoes 4 may be, for example, synthetic brake shoes molded mainly from synthetic resin, ordinary cast iron brake shoes made from ordinary cast iron composed mainly of flake graphite and pearlite, alloy cast iron brake shoes made from ordinary cast iron brake shoes with a certain amount or more of special elements such as phosphorus and chromium added, high-phosphorus cast iron brake shoes with a high phosphorus content among alloy cast iron brake shoes, or sintered alloy brake shoes made by adding multiple metal powders such as iron and copper and powders such as graphite and then sintering and press-molding them. Brake shoes 4 are actual brake shoes used on railway vehicles, just like wheels 2.

[0027] The wear amount estimation system 5 shown in Figures 1 to 4 is a system that estimates the amount of wear of brake shoes 4 that are in frictional contact. The wear amount estimation system 5 detects elastic waves emitted by the brake shoes 4 using a detection device 6, and estimates the amount of wear of the brake shoes 4 using a wear amount estimation device 7 based on the amplitude of the output signal from the detection device 6. The wear amount estimation system 5 is equipped with the detection device 6 and the wear amount estimation device 7.

[0028] The detector 6 is a device that detects elastic waves emitted by the brake shoe 4. The detector 6 detects acoustic emission (AE), a phenomenon in which elastic energy stored inside the brake shoe 4 is released as elastic waves when the brake shoe 4 is deformed or broken. The detector 6 detects elastic waves that mainly have high frequency components in the ultrasonic range (several tens of kHz to several MHz), and outputs an AE signal as an output signal. As shown in FIG. 4, the detector 6 includes an AE sensor 6a, a preamplifier 6b, a filter processing circuit 6c, and a main amplifier 6d.

[0029] The AE sensor 6a shown in Figure 4 is a detector that detects elastic waves emitted by the brake shoe 4. The AE sensor 6a is a piezoelectric element made of ceramics such as lead zirconate titanate (PZT) that converts the AE waves generated by the brake shoe 4 into an electrical signal and outputs it. At least one AE sensor 6a is attached and fixed to a surface of the brake shoe 4 other than the friction surface 4a. The preamplifier 6b is an amplifier that amplifies the AE signal output by the AE sensor 6a. The preamplifier 6b functions as a preamplifier that amplifies the weak AE signal output by the AE sensor 6a. The filter processing circuit 6c is a signal processing unit that performs predetermined signal processing on the AE signal output by the preamplifier 6b. The filter processing circuit 6c extracts signals caused by wear of the brake shoe 4 from the AE signal output by the preamplifier 6b and removes unnecessary signals such as noise components. The main amplifier 6d is an amplifier that amplifies the AE signal output by the filter processing circuit 6c. The main amplifier 6d functions as a main amplifier that amplifies the AE signal output from the filter processing circuit 6c, for example.

[0030] The wear amount estimation device 7 shown in Figs. 1 to 4 is a device that estimates the amount of wear of the brake shoe 4 that is in frictional contact. The wear amount estimation device 7 estimates the amount of wear of the brake shoe 4 when the test stand 1A applies an arbitrary braking force. The wear amount estimation device 7 calculates the amount of wear W0,W1 of the brake shoe 4 by calculating the time integral value of the maximum amplitude of the AE signal of the detection device 6 that detects the elastic waves emitted by the brake shoe 4 when the braking device 3 of the test stand 1A applies the maximum braking force. 0t The relation between R0 and R 0t is generated by a bench test. The wear amount estimation device 7 calculates the wear amount W of the brake shoe 4 when an arbitrary braking force is applied from the relational expression R0 generated when the maximum braking force is applied. f ,W ft The relation R for estimating f ,R ft The wear amount estimation device 7 calculates the time integral value of the maximum amplitude of the AE signal of the detection device 6 that detects the elastic waves emitted by the brake shoe 4 when the brake device 3 of the test stand 1A applies an arbitrary braking force, and calculates the relational expression R f ,R ftTherefore, the amount of wear W of the brake shoe 4 when an arbitrary braking force is applied is f ,W ft The wear amount estimation device 7 includes a signal input unit 8 shown in Fig. 3, a maximum amplitude calculation unit 9 shown in Figs. 3 and 4, a time integral calculation unit 10, a relational equation generation unit 11, a relational equation correction unit 12, a wear amount estimation unit 13, a data storage unit 14 shown in Fig. 3, a wear amount estimation program storage unit 15, a data display unit 16 shown in Figs. 3 and 4, a data transmission / reception unit 17 shown in Fig. 3, and a control unit 18. The wear amount estimation device 7 is configured by, for example, a personal computer, and executes predetermined processing in accordance with a wear amount estimation program.

[0031] 3 is a means for inputting the AE signal output by the detection device 6. The signal input unit 8 outputs the AE signal output by the main amplifier 6d of the detection device 6 to the control unit 18. The signal input unit 8 is, for example, an interface (I / F) circuit that inputs the AE signal (AE data) output by the detection device 6 to the control unit 18.

[0032] 3 and 4 is a means for calculating the maximum amplitude of the AE signal output by the detection device 6. The maximum amplitude calculation unit 9 calculates the absolute value of the maximum displacement of the amplitude of the AE signal based on the AE signal output by the detection device 6 as the maximum amplitude. The maximum amplitude calculation unit 9 includes a maximum amplitude calculation circuit 9a that calculates the root mean square (RMS) of the AE signal output by the detection device 6 as the maximum amplitude. The maximum amplitude calculation unit 9 stores the calculated maximum amplitude of the AE signal in the data storage unit 14 as maximum amplitude data.

[0033] 3 and 4 is a means for calculating the time integral value of the maximum amplitude of the AE signal output by the detection device 6. The time integral value calculation unit 10 calculates the time integral value as the integrated amount (area) accumulated over time for the maximum amplitude of the AE signal output by the detection device 6. As shown in FIG. 4, the time integral value calculation unit 10 includes an integration circuit 10a that calculates the time integral of the maximum amplitude of the AE signal output by the detection device 6 from the braking start time to the braking stop time. The time integral value calculation unit 10 stores the calculated time integral value of the AE signal in the data storage unit 14 as time integral value data.

[0034] The relational expression generating unit 11 calculates the time integral value of the maximum amplitude of the AE signal output by the detecting device 6 and the wear amount W of the brake shoe 4. f ,W ft The relation between R0 and R 0t The relational expression generating unit 11 generates a relational expression (i.e., a relation between the braking start time t0 and the braking stop time t) when the maximum braking force is applied at a plurality of braking initial speeds on the test stand 1A. e The relational expression generating unit 11 generates a relational expression R0 for estimating the wear amount W0 of the brake shoe 4 for one braking operation up to 1000 rpm. In addition, the relational expression generating unit 11 calculates the wear amount W of the brake shoe 4 at a certain time t when the maximum braking force is applied at a plurality of braking initial velocities on the test stand 1A. 0t The relation R for estimating 0t Generate.

[0035] (Generating a relational equation to estimate the amount of brake shoe wear when maximum braking force is applied once) Here, the process of generating the relational expression R0 for estimating the amount of wear W0 of the brake shoe 4 when the maximum braking force is applied once will be described. The relational expression generating unit 11 calculates the relation between the actual measured value of the time integral value of the maximum amplitude of the AE signal output by the detecting device 6 and the actual measured wear amount (actual measured value of the wear amount) W of the brake shoe 4 when the maximum braking force is applied at a plurality of different braking initial velocities. aHere, the initial braking speed is the speed of the train (circumferential speed of the wheels 2) when a brake command is given. The relational expression generating unit 11 calculates the measured wear amount W of the brake shoe 4 when a bench test is performed multiple times (N times) for each of a plurality of different initial braking speeds, and calculates the measured wear amount W of the brake shoe 4. a and the total value of the maximum amplitude of the AE signals output by the detection device 6 is generated as a relational expression R0. a is the value measured by measuring the weight loss of the brake shoe 4 from the start of braking to the stop when, for example, an emergency brake that generates the maximum braking force is applied at three different initial braking speeds of 35 km / h, 65 km / h, and 95 km / h. a is, for example, the time from the braking start time t0 to the braking stop time t when the maximum braking force is applied. e The wear powder generated by the brake shoe 4 is measured by an electronic balance. a For example, when a bench test is conducted to generate maximum braking force at three different initial braking speeds of 35 km / h, 65 km / h, and 95 km / h, three times for each of the initial braking speeds of 35 km / h, 65 km / h, and 95 km / h, the actual measured value of the weight loss of the brake shoe 4 equivalent to one braking. The number of tests was set to three in consideration of the minimum value of the measurement sensitivity of the electronic balance, and the more times the test is conducted, the greater the wear amount W of the brake shoe 4. f The estimation accuracy of is improved.

[0036] The relational equation generating unit 11 generates an exponential approximation equation per test as a relational equation (basic exponential approximation equation) R0 as shown in Figure 5, based on the relationship between the wear amount W0 of the brake shoe 4 and the total value of the maximum amplitude of the AE signal from the detection device 6 when the maximum braking force is applied multiple times in a bench test at multiple different initial braking speeds. Here, the vertical axis in Figure 5 represents the measured or estimated wear amount [g], and the horizontal axis represents the time integral value [V] of the maximum amplitude of the AE signal. As shown in Figure 4, the relational equation generating unit 11 includes an exponential approximation calculation circuit 11a that calculates an exponential approximation equation for estimating the wear amount W0 of the brake shoe 4 when the maximum braking force is applied once.

[0037] The relational expression generating unit 11 shown in FIGS. 3 and 4 calculates the braking force from the braking start time t0 to the braking stop time t e The relational expression R0 shown in the following equation 1 is generated to estimate the wear amount W0 of the brake shoe 4 up to the time.

[0038]

number

[0039] Here, W shown in Equation 1 f0 is the estimated wear amount (g) of the brake shoe 4 when the maximum braking force is applied once. E AE is the time integral value (V) of the maximum amplitude of the AE signal, and is the time from the braking start time t0 to the braking stop time t e a is the time integral value of the maximum amplitude of the AE signal up to 1000 kPa. a and b are coefficients of the exponential approximation curve generated by the relational expression generating unit 11. a and b are determined by the least squares method so as to minimize the difference between the actually measured wear amount and the estimated wear amount when measurements are performed six times each at initial braking speeds of 35 km / h, 65 km / h, and 95 km / h.

[0040] (Generating a relational equation to estimate the amount of brake shoe wear at a given time when maximum braking force is applied once) Next, the wear amount W of the brake shoe 4 at a certain time t when the maximum braking force is applied once ft The relation R for estimating ft The generation process will be explained. The relational expression generating unit 11 calculates the braking force from the braking start time t0 to the braking stop time t e The amount of wear W of the brake shoe 4 at a certain time t 0t The following relation R is used to estimate 0t Generate.

[0041]

number

[0042] Here, W shown in Equation 2 0t is the estimated wear amount (real-time wear amount (instantaneous value)) (g) of the brake shoe 4 at time t. E AEt is the maximum amplitude (V) of the AE signal at a certain time t. The relational expression generating unit 11 subtracts the convergence value from the exponential approximation equation as shown in FIG. 5 to obtain the wear amount W of the brake shoe 4 at time t. 0t The relational expression generating unit 11 generates an exponential approximation formula (basic exponential approximation formula) for calculating the amount of wear W of the brake shoe 4 at a certain time t when the maximum braking force is applied once, as shown in FIG. 0t The relational expression generating unit 11 includes an exponential approximation calculation circuit 11b that calculates an exponential approximation formula for estimating the relational expressions R0, R 0t is stored in the data storage unit 14 as relational expression data.

[0043] 3 and 4 is a means for correcting the relational expression R0 generated by the relational expression generating unit 11. The relational expression correcting unit 12 corrects the relational expression R0 (basic exponential approximation expression) when the maximum braking force is applied to the relational expression R0 (corrected exponential approximation expression) when an arbitrary braking force is applied. f ,R ftThe relational equation correcting unit 12 corrects the exponential approximation equation shown in Equation 1 generated by the relational equation generating unit 11 using the pressing force ratio, the initial velocity ratio, and a coefficient of the power of these ratios, which is determined by nonlinear programming from the amount of wear at an arbitrary braking force. Here, the pressing force ratio is the ratio of the pressing force when an arbitrary braking force is applied to the pressing force when the maximum braking force is applied. The initial velocity ratio is the ratio of the speed when an arbitrary braking force is applied to the speed when the maximum braking force is applied (initial braking velocity). The coefficients of the powers of the pressing force ratio and the initial velocity ratio are constants determined by nonlinear programming from the amount of wear at an arbitrary braking force. For example, the relational equation correcting unit 12 detects the pressing force based on a brake notch signal output by the test stand 1A in response to the maximum or arbitrary braking force, and calculates the pressing force ratio. The relational equation correction unit 12 detects the brake initial speed and calculates the initial speed ratio based on, for example, a speed signal output by a rotational speed detection device that detects the rotational speed of the wheel 2 when a maximum or any braking force is applied.

[0044] (Generating a relational equation to estimate the amount of brake shoe wear when a given braking force is applied once) Here, the wear amount W of the brake shoe 4 when any braking force is applied once f The relation R for estimating f The generation process will be explained. The relational expression correcting unit 12 performs a bench test in which an arbitrary braking force is applied at a plurality of different initial braking speeds, once for each of the initial braking speeds, to calculate the wear amount W of the brake shoe 4. f and the total value of the maximum amplitude of the AE signal output by the detection device 6 are expressed by the relational expression R shown in FIG. f The relational expression correcting unit 12 generates the wear amount W of the brake shoe 4 from the start of braking to the stop by applying an arbitrary braking force at three different initial braking speeds of, for example, 35 km / h, 65 km / h, and 95 km / h. f The relation R for estimating fAs shown in FIG. 4, the relational expression corrector 12 converts the exponential approximation equation for estimating the amount of wear W0 when the maximum braking force is applied once into the amount of wear W when an arbitrary braking force is applied once. f The relational equation corrector 12a calculates the exponential approximation equation for estimating the braking force from the braking start time t0 to the braking stop time t1 when an arbitrary braking force is applied. e Wear amount W of brake shoe 4 up to f The corrected relation R shown in Equation 3 below is used to estimate f Generate.

[0045]

number

[0046] Here, W shown in Equation 3 f is the estimated wear amount (g) of the brake shoe 4 per one application of any brake. P i is the pressing force (kN) when an arbitrary brake (i notch) is applied. P e is the pressing force (kN) when the maximum brake (emergency brake) is applied. i is the arbitrary braking force (pressing force P i ) is the train speed (circumferential speed of wheel 2 (initial braking speed)) (km / h) when a braking command is received. e is the maximum braking force (pressing force P e where n1 is the speed of the train (circumferential speed of wheel 2 (maximum initial speed)) (km / h) when a brake command to apply brake shoe 4 is received. c is the pressing force ratio. d is the initial speed ratio. n1 to n4 are coefficients of the exponents of the pressing force ratio c and the initial speed ratio d. For example, n1 to n4 are determined by nonlinear programming so as to minimize the difference between the measured wear amount and the estimated wear amount when braking is performed once for each of initial braking speeds of 35 km / h, 65 km / h, and 95 km / h. The coefficients n1 to n4 shown in Table 1 are an example when estimating the wear amount of the brake shoe 4 when there are 7 brake notches. Here, the coefficient n4 shown in Table 1 may differ depending on the type and notch of the brake shoe 4.

[0047] [Table 1]

[0048] (Generating a relational equation to estimate the amount of brake shoe wear at a given time when any braking force is applied once) Next, the amount of wear W of the brake shoe 4 at a certain time t when an arbitrary braking force is applied once ft The relation R for estimating ft The generation process will be explained. When an arbitrary braking force is applied, the relational expression correction unit 12 calculates the braking force from the braking start time t0 to the braking stop time t e The amount of wear W of the brake shoe 4 at a certain time t ft The corrected relation R shown in Equation 4 below is used to estimate ft Generate.

[0049]

number

[0050] Here, W shown in Equation 4 ft is the estimated wear amount (real-time wear amount (instantaneous value)) (g) of the brake shoe 4 at time t. E AEt is the maximum amplitude (V) of the AE signal at time t. The relational expression corrector 12 subtracts the convergence value from the corrected exponential approximation equation shown in Equation 3 to obtain the wear amount W of the brake shoe 4 at time t. ft The relational expression corrector 12 generates an exponential approximation formula shown in Equation 4 for estimating the amount of wear W0 when the maximum braking force is applied once, as shown in FIG. 4, by converting the exponential approximation formula for estimating the amount of wear W0 at a certain time t when an arbitrary braking force is applied once. ft The relational equation corrector 12 includes an exponential approximation correction circuit 12b that corrects the relational equation R f ,R ft is stored in the data storage unit 14 as corrected relational expression data.

[0051] The wear amount estimation unit 13 shown in FIGS. 3 and 4 estimates the wear amount W of the brake shoe 4 based on the amplitude of the AE signal output by the detection device 6. f ,W ft The wear amount estimation unit 13 is a means for estimating the wear amount W of the brake shoe 4 based on the time integral value of the maximum amplitude of the AE signal output by the detection device 6. f ,W ft The relation R f ,R ft Based on this, the wear amount W of the brake shoe 4 f ,W ft The wear amount estimation unit 13 receives as an input signal the time integral value of the maximum amplitude of the AE signal output by the detection device 6 when the brake device 3 of the test stand 1A applies an arbitrary braking force, and estimates the wear amount W of the brake shoe 4 by using Equations 3 and 4. f ,W ft Calculate the wear amount W of the brake shoe 4 after calculation. f ,W ft is output as the output signal.

[0052] (Estimation of brake shoe wear when applying a given braking force once) The wear amount estimation unit 13 calculates the wear amount W of the brake shoe 4 when an arbitrary braking force is applied based on the exponential approximation formula shown in Equation 3. f The wear amount estimation unit 13 estimates the time integral value of the maximum amplitude of the AE signal output by the maximum amplitude calculation unit 9 when the brake device 3 of the test stand 1A applies an arbitrary braking force, and the corrected relational expression (corrected exponential approximation expression) R shown in Equation 3 corrected by the relational expression correction unit 12. f Based on this, the wear amount W of the brake shoe 4 f The wear amount estimation unit 13 estimates the wear amount W of the brake shoe 4 based on the coefficients n1 to n4 of the powers of the pressing force ratio c and the initial speed ratio d, which are determined by nonlinear programming from the pressing force ratio c, the initial speed ratio d, and the wear amount at an arbitrary braking force, and the corrected exponential approximation formula shown in Equation 3 corrected by the relational formula correction unit 12. f The wear amount estimation unit 13 estimates the wear amount from the braking start time t0 to the braking stop time t when the braking device 3 of the test stand 1A applies an arbitrary braking force. e Wear amount W of brake shoe 4 up to fis calculated by Equation 3. The wear amount estimation unit 13 calculates the wear amount W of the brake shoe 4 as shown in FIG. f The wear amount calculation circuit 13a calculates the wear amount.

[0053] (Estimation of brake shoe wear at a certain time when a given braking force is applied once) When an arbitrary braking force is applied, the wear amount estimation unit 13 estimates the amount of wear from the braking start time t0 to the braking stop time t e The amount of wear of the brake shoe 4 at a certain time t (real-time wear amount (instantaneous value)) W ft is calculated by Equation 4. As shown in FIG. 4, the wear amount estimation unit 13 calculates the instantaneous wear amount W of the brake shoe 4 at a certain time t. ft The wear amount estimating unit 13 is provided with a wear amount calculation circuit 13b that calculates the wear amount W of the brake shoe 4 after calculation. f ,W ft is stored in the data storage unit 14 as wear amount data.

[0054] 3 is a means for storing various data related to the wear amount estimation device 7. The data storage unit 14 is a storage device that stores, for example, the AE data output by the signal input unit 8, the maximum amplitude data calculated by the maximum amplitude calculation unit 9, the time integral value data calculated by the time integral value calculation unit 10, the relational expression data generated by the relational expression generation unit 11, the corrected relational expression data corrected by the relational expression correction unit 12, the wear amount data estimated by the wear amount estimation unit 13, and the like.

[0055] The wear amount estimation program storage unit 15 calculates the wear amount W of the brake shoe 4 in frictional contact. f ,W ft The wear amount estimation program storage unit 15 is a storage device that stores a wear amount estimation program read from an information recording medium or a wear amount estimation program downloaded via an electric communication line.

[0056] 3 and 4 is a means for displaying various data related to the wear amount estimation device 7. The data display unit 16 displays, for example, the AE data output by the signal input unit 8, the relational equation generated by the relational equation generation unit 11, the corrected relational equations corrected by the relational equation correction units 12A and 12B, the wear amount W estimated by the wear amount estimation unit 13, and other data related to the wear amount estimation device 7. f ,W ft The data display unit 16 is a display device that displays the amount of wear W per braking, etc., on a screen, as shown in FIG. f a wear amount display circuit 16a that displays the amount of wear W at a certain time t; ft The wear amount display circuit 16b displays the wear amount in real time.

[0057] 3 is a means for transmitting and receiving various data related to the wear amount estimation device 7. The data transmission and reception unit 17 is a transmission and reception device that wirelessly or wiredly transmits and receives, for example, relational equation data generated by the relational equation generation unit 11, relational equation data corrected by the relational equation correction unit 12A, and the like.

[0058] The control unit 18 is a central processing unit (CPU) that controls various operations related to the wear amount estimation device 7. The control unit 18 reads out the wear amount estimation program from the wear amount estimation program storage unit 15, and executes the wear amount estimation process in accordance with this wear amount estimation program. For example, the control unit 18 instructs the maximum amplitude calculation unit 9 to calculate the maximum amplitude of the AE signal, instructs the time integral calculation unit 10 to calculate the time integral value of the maximum amplitude of the AE signal, and calculates the relational expression R0,R that expresses the relationship between the time integral value of the maximum amplitude of the AE signal and the wear amount of the brake shoe 4. 0t to the relational expression generating unit 11, to correct the relational expression R0 to the relational expression correcting unit 12, and to calculate the wear amount W of the brake shoe 4. f ,W ftThe control unit 18 instructs the wear amount estimation unit 13 to estimate the wear amount, the data storage unit 14 to store various data, the data display unit 16 to display various data, and the data transmission / reception unit 17 to transmit and receive various data. The control unit 18 connects the signal input unit 8, the maximum amplitude calculation unit 9, the time integral value calculation unit 10, the relational equation generation unit 11, the relational equation correction unit 12, the wear amount estimation unit 13, the data storage unit 14, the wear amount estimation program storage unit 15, the data display unit 16, and the data transmission / reception unit 17 so that they can communicate with each other.

[0059] Next, a wear amount estimation method according to a first embodiment of the present invention will be described. In the following, the amount of wear W of the brake shoe 4 when the brake device 3 of the test stand 1A applies an arbitrary braking force in the bench test will be described. f ,W ft This will be explained by taking an example in which the following is estimated. The wear amount estimation method #100 shown in FIG. 7 is the wear amount W f ,W ft The wear amount estimation method #100 includes a maximum brake bench test step #110, a maximum amplitude calculation step #120, a time integral value calculation step #130, a relational equation generation step #140, an arbitrary brake bench test step #150, a maximum amplitude calculation step #160, a time integral value calculation step #170, a relational equation correction step #180, and a bench wear amount estimation step #190. In the bench wear amount estimation method #100, the wear amounts W0 and W1 of the brake shoe 4 when the maximum braking force is applied in the bench test are calculated. 0t From the relational expression R0 that estimates the wear amount W when any braking force is applied in a bench test, f ,W ft The relation R that estimates f ,R ft The amount of wear W of the brake shoe 4 when any brake is applied by a bench test is generated. f ,W ft The relation R f ,R ft It is estimated by:

[0060] The maximum brake bench test process #110 is a process in which a bench test is performed using the test bench 1A with maximum braking force. In the maximum brake bench test process #110, a bench test is performed multiple times for each of a number of different initial braking speeds, in which maximum braking force is applied from the start of braking to the end of braking. In the maximum brake bench test process #110, for example, the brake shoe 4 of the brake device 3 of the test bench 1A is pressed against the wheel 2 with a predetermined pressing force during maximum braking to perform the bench test.

[0061] The maximum amplitude calculation step #120 is a step of calculating the maximum amplitude of the AE signal output by the detection device 6 when the maximum braking force is applied. In the maximum amplitude calculation step #120, the wear amount estimation device 7 calculates the absolute value of the maximum displacement of the amplitude of the AE signal output by the detection device 6 for each of a plurality of different initial braking speeds.

[0062] The time integral calculation step #130 is a step of calculating the time integral of the maximum amplitude of the AE signal output by the detection device 6 when the maximum braking force is applied. In the time integral calculation step #130, the wear amount estimation device 7 calculates the time integral of the maximum amplitude of the AE signal output by the detection device 6, which is integrated over time for each of a plurality of different initial braking speeds.

[0063] The relational expression generation process #140 calculates the time integral value of the maximum amplitude of the AE signal during maximum braking and the wear amount W0,W of the brake shoe 4. 0t The relation between R0 and R 0t In the relational expression generation step #140, as shown in FIG. 5, the relational expression is calculated based on the time from the braking start time t0 to the braking stop time t e The time integral value of the maximum amplitude of the AE signal (time integral value of the maximum amplitude for one braking stroke) and the wear amount of brake shoe 4 (wear amount for one braking stroke) W f0 The wear amount estimation device 7 generates an exponential approximation formula representing the relationship between the maximum braking force and the braking start time t0 to the braking stop time t1 as shown in Equation 1. eThe real-time wear amount W of the brake shoe 4 at a certain time t 0t The exponential approximation formula for estimating is the relation R shown in Equation 2. 0t The wear amount estimation device 7 generates the following.

[0064] The optional brake bench test process #150 is a process in which a bench test is performed using the test bench 1A with an optional braking force. In the optional brake bench test process #150, a bench test is performed in which an optional braking force is applied from the start of braking to the stop at multiple different initial braking speeds, once for each initial braking speed. In the optional brake bench test process #150, for example, the brake shoe 4 of the brake device 3 of the test bench 1A is pressed against the wheel 2 with a pressing force corresponding to an optional brake notch to perform the bench test.

[0065] The maximum amplitude calculation step #160 is a step of calculating the maximum amplitude of the AE signal output by the detection device 6 when a given braking force is applied. In the maximum amplitude calculation step #160, the wear amount estimation device 7 calculates the absolute value of the maximum displacement of the amplitude of the AE signal output by the detection device 6 when a given braking force is applied.

[0066] The time integral calculation step #170 is a step of calculating the time integral of the maximum amplitude of the AE signal output by the detection device 6 when an arbitrary braking force is applied. In the time integral calculation step #170, the wear amount estimation device 7 calculates the time integral of the maximum amplitude of the AE signal output by the detection device 6 when an arbitrary braking force is applied.

[0067] The relational expression correction process #180 corrects the relational expression R0, which represents the relationship between the time integral value of the maximum amplitude of the AE signal when the maximum brake is applied and the wear amount W0 of the brake shoe 4, by correcting the relational expression R0, which represents the relationship between the time integral value of the maximum amplitude of the AE signal when an arbitrary braking force is applied and the wear amount W0 of the brake shoe 4. f ,W ft The relation R f ,R ftIn the relational expression correction step #180, as shown in FIG. 6, the time period from the braking start time t0 to the braking stop time t when an arbitrary braking force is applied is corrected to e The time integral value of the maximum amplitude of the AE signal (time integral value of the maximum amplitude for one braking stroke) and the wear amount of brake shoe 4 (wear amount for one braking stroke) W f The exponential approximation formula that expresses the relationship between f In relational expression correction step #180, the wear amount estimation device 7 generates the corrected relational expression R shown in Equation 3 based on the pressing force ratio c between the pressing force when the maximum braking force is applied and the pressing force when an arbitrary braking force is applied, the initial speed ratio d between the initial braking speed when the maximum braking force is applied and the initial braking speed when an arbitrary braking force is applied, the coefficients n1 to n4 of the powers of these ratios, and the exponential approximation equation shown in Equation 1 generated in relational expression generation step #140. f In the relational expression correction step #180, the wear amount estimation device 7 generates the relational expression t0. e The real-time wear amount W of the brake shoe 4 at a certain time t ft The exponential approximation formula for estimating is the relation R shown in Equation 4. ft The wear amount estimation device 7 generates the following.

[0068] The on-table wear amount estimation process #190 is to estimate the wear amount W of the brake shoe 4 based on the amplitude of the AE signal output by the detection device 6. f ,W ft In the on-table wear amount estimation step #190, the time integral value of the maximum amplitude of the AE signal output by the detection device 6 and the wear amount W of the brake shoe 4 are calculated. f ,W ft The relation R f ,R ft Based on this, the wear amount W of the brake shoe 4 f ,W ft In the bench wear amount estimation step #190, when the test stand 1A applies an arbitrary braking force in the bench test, the time integral value of the maximum amplitude of the AE signal output by the detection device 6 is used as an input signal, and the wear amount estimation unit 13 calculates the relational expression R f ,R ft The wear amount W of brake shoe 4 is calculated byf ,W ft The wear amount W of brake shoe 4 is estimated. f ,W ft In the on-table wear amount estimation process #190, when an arbitrary braking force is applied, the time from the braking start time t0 to the braking stop time t e Wear amount W of brake shoe 4 up to f In the on-table wear amount estimation process #190, when an arbitrary braking force is applied, the time from the braking start time t0 to the braking stop time t e The wear amount (real-time wear amount) of the brake shoe 4 at a certain time t until ft Estimate.

[0069] Next, the operation of the wear amount estimating device according to the first embodiment of the present invention will be described. In the following, the amount of wear W of the brake shoe 4 when the brake device 3 of the test stand 1A applies an arbitrary braking force in the bench test will be described. f ,W ft The operation of the control unit 18 shown in FIG. 3 will be mainly described below by taking the case where the above-mentioned parameter is estimated as an example. 8, in step (hereinafter referred to as S) 100, the control unit 18 reads the wear amount estimation program from the wear amount estimation program storage unit 15. When the control unit 18 reads the wear amount estimation program, the control unit 18 starts a series of wear amount estimation processes.

[0070] In S110, the control unit 18 commands the maximum amplitude calculation unit 9 to calculate the maximum amplitude of the AE signal during maximum braking. As a result, the maximum amplitude calculation unit 9 calculates the maximum amplitude of the AE signal output by the detection device 6 when the brake device 3 of the test stand 1A applies the maximum braking force to the brake shoe 4.

[0071] In S120, the control unit 18 commands the time integral value calculation unit 10 to calculate the time integral value of the AE signal during maximum braking. As a result, when the brake device 3 of the test stand 1A applies the maximum braking force to the brake shoe 4, the time integral value calculation unit 10 calculates the time integral value of the maximum amplitude of the AE signal output by the detection device 6.

[0072] In S130, the relationship between W0 and W at maximum braking 0t As a result, the time integral value of the maximum amplitude of the AE signal when the maximum braking force is applied and the wear amount W0,W 0t The relation between R0 and R 0t The relational expression generating unit 11 generates the exponential approximation expressions shown in Expressions 1 and 2, where:

[0073] In S140, the control unit 18 commands the maximum amplitude calculation unit 9 to calculate the maximum amplitude of the AE signal during arbitrary braking. As a result, when the brake device 3 of the test stand 1A applies an arbitrary braking force to the brake shoe 4, the maximum amplitude calculation unit 9 calculates the maximum amplitude of the AE signal output by the detection device 6.

[0074] In S150, the control unit 18 commands the time integral value calculation unit 10 to calculate the time integral value of the AE signal during arbitrary braking. As a result, when the brake device 3 of the test stand 1A applies an arbitrary braking force to the brake shoe 4, the time integral value calculation unit 10 calculates the time integral value of the maximum amplitude of the AE signal output by the detection device 6.

[0075] In S160, the relational expression R at the time of arbitrary braking f ,R ft As a result, the relational expression R0,R2 when the maximum braking force is applied is 0t The exponential approximation formula shown in Equation 1 is expressed as the relational formula R when an arbitrary braking force is applied. f ,R ft The relational equation correcting unit 12 corrects the exponential approximation equations shown in Equation 2 and Equation 3 as follows:

[0076] In S170, the wear amount W of the brake shoe 4 when an arbitrary braking force is applied f ,W ft The control unit 18 instructs the wear amount estimation unit 13 to estimate the relation R. When the test stand 1A applies an arbitrary braking force in the bench test, the wear amount estimation unit 13 calculates the time integral value of the maximum amplitude of the AE signal output by the detection device 6 using the relation R. f ,Rft Enter the wear amount W of brake shoe 4 f ,W ft The wear amount W of brake shoe 4 is estimated. f ,W ft As a result, when an arbitrary braking force is applied, the braking force is output from the braking start time t0 to the braking stop time t e Wear amount W of brake shoe 4 up to f The wear amount estimation unit 13 estimates the amount of wear. When an arbitrary braking force is applied, the amount of wear is calculated from the braking start time t0 to the braking stop time t e The wear amount (real-time wear amount) of the brake shoe 4 at a certain time t until ft The wear amount estimation unit 13 estimates the amount of wear.

[0077] The method and device for estimating the amount of wear of a friction material according to the first embodiment of the present invention have the following advantages. (1) In the first embodiment, the wear amount W of the brake shoe 4 is calculated based on the amplitude of the AE signal output by the detector 6 that detects the elastic waves emitted by the brake shoe 4. f ,W ft Therefore, the wear amount W of the brake shoe 4 is estimated by using the amplitude of the elastic wave obtained by the AE method. f ,W ft Furthermore, unlike qualitative evaluation using a small test piece of the brake shoe 4, the amount of wear W of the brake shoe 4 can be estimated with high accuracy using a full-size brake shoe 4. f ,W ft can be quantitatively evaluated.

[0078] (2) In the first embodiment, a relational expression R that represents the relationship between the time integral value of the maximum amplitude of the AE signal output by the detection device 6 and the amount of wear of the brake shoe 4 is used. f ,R ft Based on this, the wear amount W of the brake shoe 4 f ,W ft Therefore, the wear amount W of the brake shoe 4 can be estimated based on the amplitude of the AE signal output when an arbitrary braking force is applied to the brake shoe 4, which allows the performance and wear of the brake shoe 4 to be evaluated with high accuracy. f ,W ftcan be estimated with high accuracy. In addition, the time integral of the maximum amplitude of the AE signal is calculated using the relation R f ,R ft The wear amount W of brake shoe 4 is calculated by f ,W ft The wear amount W of brake shoe 4 can be converted into f ,W ft As a result, the wear amount W of the brake shoe 4 can be quantitatively evaluated, compared to a general estimation method that uses an approximation formula obtained from the relational formula between the initial braking speed and the wear amount. f ,W ft This can improve the estimation accuracy.

[0079] (3) In the first embodiment, when an arbitrary braking force is applied, the braking force is applied from the braking start time t0 to the braking stop time t e Wear amount W of brake shoe 4 up to f Therefore, it is possible to estimate the amount of wear W per braking when applying any brake to a full-scale brake shoe 4, which was previously considered impossible. f Furthermore, compared to collecting wear debris discharged from the brake shoe 4 or visualizing and measuring the wear debris through image analysis, the amount of wear W of the brake shoe 4 can be estimated with high accuracy without being affected by external disturbances such as wind. f can be estimated with high accuracy.

[0080] (4) In the first embodiment, when an arbitrary braking force is applied, the braking force is applied from the braking start time t0 to the braking stop time t e The amount of wear W of the brake shoe 4 at a certain time t ft Therefore, it is possible to estimate the instantaneous wear amount W of the brake shoe 4, which has been difficult to estimate in the past. ft can be estimated with high accuracy in real time.

[0081] (5) In the first embodiment, when the maximum braking force is applied, the braking time from the braking start time t0 to the braking stop time t e The time integral value of the maximum amplitude of the AE signal output by the detector 6 from the braking start time t0 to the braking stop time t e Wear amount W of brake shoe 4 up tof ,W ft Based on the exponential approximation formula that expresses the relationship between the wear amount W of the brake shoe 4 when an arbitrary braking force is applied, f ,W ft Therefore, the time integral value of the maximum amplitude of the AE signal obtained during emergency braking, which generates the maximum braking force, and the measured wear amount W a The exponential approximation formula is generated from the relationship between the wear amount W of the brake shoe 4 when an arbitrary braking force is applied. f ,W ft can be converted to high accuracy using this exponential approximation formula. For example, by obtaining the exponential approximation formula generated when applying emergency braking at three different initial braking speeds as a base, the wear amount W of the brake shoe 4 when applying any brake can be calculated. f ,W ft can be estimated with high accuracy using an exponential approximation formula.

[0082] (6) In the first embodiment, the wear amount W of the brake shoe 4 is calculated based on the pressing force ratio c, which is the ratio of the pressing force when an arbitrary braking force is applied to the pressing force when the maximum braking force is applied, the initial speed ratio d, which is the ratio of the speed when an arbitrary braking force is applied to the speed when the maximum braking force is applied, and the coefficients n1 to n4 of the powers of these ratios, which are determined by nonlinear programming from the wear amount at the arbitrary braking force, and an exponential approximation formula. f ,W ft Therefore, the exponential approximation formula when the maximum braking force is applied can be easily corrected to the exponential approximation formula when an arbitrary braking force is applied, and the wear amount W f ,W ft can be estimated with high accuracy.

[0083] (7) In this first embodiment, the wear amount W of the brake shoe 4 is calculated based on the amplitude of the AE signal output from the detector 6 that detects the elastic waves emitted by the brake shoe 4 of the braking device 3 of the test stand 1A. f ,W ftTherefore, when the brake device 3 of the test stand 1A applies an arbitrary braking force in the bench test, the wear amount W of the brake shoe 4 of the brake device 3 of the test stand 1A is estimated. f ,W ft can be estimated with high accuracy.

[0084] (Second embodiment) In the following, the same or corresponding parts as those shown in FIGS. 1 to 4 are denoted by the same or corresponding reference numerals, and detailed description thereof will be omitted. The second embodiment shown in FIGS. 9 and 10 differs from the first embodiment shown in FIGS. 3 and 4 in that the amount of wear W of the brake shoe 4 when a braking device 3B of an actual vehicle (real vehicle) 1B applies an arbitrary braking force is measured. f ,W ft 9 and 10 is a passage (track) on which the vehicle 1B runs. The track T has a pair of left and right rails that support and guide the wheels 2 of the vehicle 1B to allow the vehicle 1B to run.

[0085] Vehicle 1B is a moving body that travels along track T. Vehicle 1B is, for example, a railway vehicle such as an electric train, a diesel railcar, a locomotive, a passenger car, or a freight car. Vehicle 1B comprises a car body 1a and a bogie 1b. Car body 1a is a structure for loading and transporting passengers or cargo. Bogie 1b is a running device (traveling gear) that supports car body 1a and travels. Bogie 1b comprises wheels 2 and a braking device 3, and the braking device 3 is supported by a bogie frame.

[0086] 9 and 10 is installed on a test stand 1A, and a brake device 3B is mounted on a vehicle 1B. The brake device 3B presses a brake shoe 4 against a wheel 2 with a pressing force calculated based on the pressure in the brake cylinder (BC pressure) and the mechanical specifications of the basic brake device (pressing device).

[0087] The wear amount estimation system 5 detects the elastic waves emitted by the brake shoe 4 of the braking device 3B on the vehicle 1B side by the detection device 6B, and estimates the wear amount W of the brake shoe 4 based on the amplitude of the output signal from the detection device 6B.f ,W ft is estimated by a wear amount estimation device 7B. The wear amount estimation system 5 is equipped with detection devices 6A, 6B and wear amount estimation devices 7A, 7B. The detection devices 6A, 6B are devices that detect elastic waves emitted by the brake shoe 4. The detection device 6A detects elastic waves emitted by the brake shoe 4 of the braking device 3A on the test stand 1A side, and the detection device 6B detects elastic waves emitted by the brake shoe 4 of the braking device 3B on the vehicle 1B side.

[0088] The wear amount estimation devices 7A and 7B estimate the wear amount W of the brake shoe 4 of the brake device 3B on the vehicle 1B side when an arbitrary braking force is applied to the vehicle 1B. f ,W ft The wear amount estimation device 7A estimates the wear amount W0,W of the brake shoe 4 of the braking device 3A by calculating the time integral value of the maximum amplitude of the AE signal of the detection device 6A that detects the elastic waves emitted by the brake shoe 4 of the braking device 3A when the maximum braking force is applied through a bench test using the test stand 1A. 0t The relation between R0 and R 0t The wear amount estimation device 7A includes a signal input unit 8A shown in Fig. 9, a maximum amplitude calculation unit 9A shown in Figs. 9 and 10, a time integral calculation unit 10A, a relational equation generation unit 11, a data storage unit 14A shown in Fig. 9, a wear amount estimation program storage unit 15A, a data display unit 16A, a data transmission / reception unit 17A, and a control unit 18A.

[0089] The wear amount estimation device 7B calculates the relational expression R0, R1 generated when the braking device 3A on the test stand 1A side applies the maximum braking force. 0t When the brake device 3B on the vehicle 1B side applies an arbitrary braking force, the wear amount W of the brake shoe 4 of the brake device 3B is calculated. f ,W ft The relation R for estimating f ,R ft The wear amount estimation device 7B calculates the time integral value of the maximum amplitude of the AE signal of the detection device 6B that detects the elastic waves emitted by the brake shoe 4 of the brake device 3B when the brake device 3B on the vehicle 1B side applies an arbitrary braking force, and calculates the time integral value of the maximum amplitude of the AE signal of the detection device 6B that detects the elastic waves emitted by the brake shoe 4 of the brake device 3B. f ,R ftTherefore, the amount of wear W of the brake shoe 4 of the brake device 3B when the brake device 3B on the vehicle 1B side applies an arbitrary braking force is f ,W ft The wear amount estimation device 7B includes a signal input unit 8B shown in Fig. 9, a maximum amplitude calculation unit 9B shown in Figs. 9 and 10, a time integral calculation unit 10B, a relational equation correction unit 12B, a data storage unit 14B shown in Fig. 9, a wear amount estimation program storage unit 15B, a data display unit 16B shown in Figs. 9 and 10, a data transmission / reception unit 17B shown in Fig. 9, and a control unit 18B.

[0090] The relational expression generating unit 11 shown in FIGS. 9 and 10 calculates the time integral value of the maximum amplitude of the AE signal output by the detection device 6A on the test stand 1A side of the bench test and the wear amount W of the brake shoe 4. f ,W ft The relation between R0 and R 0t Since the set values ​​of the braking force on the vehicle 1B and the test stand 1A are different, the relational expression generating unit 11 generates the wear amounts W0 and W1 of the brake shoes 4 when the test stand test is performed with the set value of the braking force on the vehicle 1B side. 0t The exponential approximation formulas shown in Equation 1 and Equation 2 for estimating R0 and R 0t Generate it as:

[0091] The relational expression correction unit 12 converts the relational expression (basic exponential approximation expression) R0 when the maximum braking force is applied by the brake device 3A on the test stand 1A side into the relational expression (corrected exponential approximation expression) R0 when an arbitrary braking force is applied by the brake device 3B on the vehicle 1B side. f ,R ft The relational expression correcting unit 12 corrects the exponential approximation formula shown in Equation 3 into the relational expression R by performing an on-board test in which an arbitrary braking force is applied at a plurality of different initial braking speeds once for each initial braking speed. fThe relational expression correcting unit 12 detects the pressing force based on, for example, the pressure in the brake cylinder when an arbitrary braking force is applied and the mechanical specifications of the brake device 3B, and calculates the pressing force ratio c shown in Equation 3. The relational expression correcting unit 12 detects the braking initial speed based on, for example, a speed signal output by a tachograph that detects the rotational speed of the wheel 2 when an arbitrary braking force is applied, and calculates the initial speed ratio d shown in Equation 3. The relational expression correcting unit 12 calculates the initial speed ratio d shown in Equation 3 from the braking start time t0 to the braking stop time t when the brake device 3B on the vehicle 1B side applies an arbitrary braking force. e Wear amount W of brake shoe 4 up to f The corrected relation R shown in Equation 3 is used to estimate f When the brake device 3B on the vehicle 1B side applies an arbitrary braking force, the relational expression correction unit 12 generates a relational expression (T0) from the braking start time t0 to the braking stop time t e The amount of wear W of the brake shoe 4 at a certain time t ft The corrected relation R shown in Equation 4 is used to estimate ft Generate.

[0092] The wear amount estimation unit 13 estimates the wear amount W of the brake shoe 4 based on the amplitude of the AE signal output by the detection device 6B on the vehicle 1B side. f ,W ft The wear amount estimation unit 13 estimates the wear amount from the braking start time t0 to the braking stop time t when the braking device 3B on the vehicle 1B running on the track T applies an arbitrary braking force. e Wear amount W of brake shoe 4 up to f is calculated by Equation 3. The wear amount estimation unit 13 calculates the wear amount from the braking start time t0 to the braking stop time t when the braking device 3B on the side of the vehicle 1B running on the track T applies an arbitrary braking force. e The amount of wear of the brake shoe 4 at a certain time t (real-time wear amount (instantaneous value)) W ft is calculated using equation 4.

[0093] 9 stores relational expression data generated by the relational expression generating unit 11, and data storage unit 14B stores corrected relational expression data corrected by the relational expression correcting unit 12, wear amount data estimated by the wear amount estimating unit 13, and the like. Data display unit 16A displays the relational expression generated by the relational expression generating unit 11, and data display unit 16B displays the corrected relational expression corrected by the relational expression correcting unit 12, wear amount W estimated by the wear amount estimating unit 13, and the like. f ,W ft The data transmitter / receiver 17B transmits and receives various data to and from the data transmitter / receiver 17A on the wear amount estimation device 7A side. The data transmitter / receiver 17B receives, for example, relational equation data generated by the relational equation generation unit 11.

[0094] The control units 18A and 18B control various operations related to the wear amount estimation devices 7A and 7B. For example, the control unit 18A calculates the relational expressions R0 and R1 when the maximum braking force is applied to the test stand 1A. 0t The control unit 18A instructs the relational equation generating unit 11 to generate the relational equation data generated by the relational equation generating unit 11, and instructs the relational equation generating unit 11 to transmit the relational equation data generated by the relational equation generating unit 11. For example, the control unit 18A generates the corrected relational equation R when an arbitrary braking force is applied to the vehicle 1B. f ,R ft The relational expression corrector 12 is instructed to generate the following.

[0095] Next, a wear amount estimation method according to a second embodiment of the present invention will be described. 7. In the following, detailed explanations of steps that are the same as or correspond to the steps shown in Fig. 7 will be omitted. Also, in the following, the amount of wear W of the brake shoe 4 when the brake device 3B on the vehicle 1B side applies an arbitrary braking force will be f ,W ft This will be explained by taking an example in which the following is estimated. The wear amount estimation method #100 shown in Figure 6 includes a maximum brake bench test step #110, a maximum amplitude calculation step #120, a time integral value calculation step #130, a relational expression generation step #140, an arbitrary brake on-vehicle test step #200, a maximum amplitude calculation step #210, a time integral value calculation step #220, a relational expression correction step #230, and an on-vehicle wear amount estimation step #240. In the wear amount estimation method #100, the wear amounts W0 and W1 of the brake shoe 4 when the maximum braking force is applied in the bench test are calculated. 0t From the relational expression R0 that estimates the wear amount W when any braking force is applied in an on-board test, f ,W ft The relation R that estimates f ,R ft is generated, and the wear amount W of the brake shoe 4 when any brake is applied on the vehicle is calculated. f ,W ft The relation R f ,R ft It is estimated by:

[0096] Maximum brake bench test process #110 is a process in which a bench test is conducted using test stand 1A with maximum braking force. In maximum brake bench test process #110, the maximum braking force set in brake device 3B on vehicle 1B is applied by test stand 1A from the start of braking to a stop at multiple different initial braking speeds, and a bench test is conducted multiple times for each initial braking speed. In maximum brake bench test process #110, brake device 3A on test stand 1A presses brake shoe 4 against wheel 2 with the same pressing force as the emergency brake pressing force in which brake device 3B on vehicle 1B applies maximum braking force.

[0097] The optional brake on-board test process #200 is a process in which an on-board test is performed using vehicle 1B with an optional braking force. In the optional brake on-board test process #200, an on-board test is performed in which an optional braking force set in the brake device 3B on vehicle 1B is applied from the start of braking to the stop at multiple different initial braking speeds, once for each initial braking speed. In the optional brake bench test process #150, for example, an on-board test is performed by pressing the brake shoe 4 of the brake device 3B on vehicle 1B against the wheel 2 with a pressing force corresponding to an optional brake notch.

[0098] The wear amount estimation step #240 is to estimate the wear amount W of the brake shoe 4 of the brake device 3B on the vehicle 1B side based on the amplitude of the AE signal output by the detection device 6B on the vehicle 1B side. f ,W ft In the wear amount estimation step #240, when the brake device 3B of the actual vehicle 1B applies an arbitrary braking force, the wear amount estimation unit 13 uses the time integral value of the maximum amplitude of the AE signal output by the detection device 6B as an input signal and calculates the relational expression R f ,R ft The wear amount W of brake shoe 4 is calculated by f ,W ft The wear amount W of brake shoe 4 is estimated. f ,W ft In the wear amount estimation process #240, when the brake device 3B on the vehicle 1B running on the track T applies a given braking force, the brake amount is calculated based on the time from the braking start time t0 to the braking stop time t e Wear amount W of brake shoe 4 up to f In the wear amount estimation process #240, when the brake device 3B on the vehicle 1B running on the track T applies an arbitrary braking force, the wear amount is estimated from the braking start time t0 to the braking stop time t e The wear amount (real-time wear amount) of the brake shoe 4 at a certain time t until ft Estimate.

[0099] Next, the operation of the wear amount estimating device according to the second embodiment of the present invention will be described. In the following, detailed description of the same or corresponding processes as those shown in Fig. 8 will be omitted. Also, in the following, the amount of wear W of the brake shoe 4 when the brake device 3B of the actual vehicle 1B applies an arbitrary braking force will be described. f ,W ft The operation of the control units 18A and 18B shown in FIG. 9 will be mainly described below using an example in which the above-mentioned case is estimated. In S130 shown in FIG. 12, the time integral value of the maximum amplitude of the AE signal when the maximum braking force is applied by the brake device 3A on the test stand 1A side in the bench test and the wear amount W0, W 0t The relation between R0 and R 0t The relational expression generating unit 11 generates the exponential approximation expressions shown in Expressions 1 and 2, where:

[0100] In S131, the control unit 18A commands the data transmitter / receiver 17A to transmit relational expression data. As a result, the data transmitter / receiver 17A on the wear amount estimation device 7A side transmits the relational expressions R0 and R1 shown in Equation 1 and Equation 2 generated by the relational expression generating unit 11 to the data transmitter / receiver 17B on the wear amount estimation device 7B side. 0t The relational expression data regarding is transmitted.

[0101] In S201, the control unit 18B determines whether or not the relational equation data has been received. If the data transmitter / receiver 17B on the wear amount estimation device 7B side has received the relational equation data from the data transmitter / receiver 17A on the wear amount estimation device 7A side, the process proceeds to S240, but if the data transmitter / receiver 17B on the wear amount estimation device 7B side has not received the relational equation data from the data transmitter / receiver 17A on the wear amount estimation device 7A side, the series of wear amount estimation processes ends.

[0102] In S260, the exponential approximation formula shown in Equation 1, which is the relational formula R0 when the brake device 3A on the test stand 1A applies the maximum braking force, is converted into the relational formula R when the brake device 3B on the vehicle 1B applies an arbitrary braking force. f ,R ft The relational equation correcting unit 12 corrects the exponential approximation equations shown in Equation 2 and Equation 3 as follows:

[0103] In S270, when the brake device 3B on the side of the vehicle 1B running on the track T applies an arbitrary braking force, the wear amount estimation unit 13 calculates the time integral value of the maximum amplitude of the AE signal output by the detection device 6B using the relational expression R f ,R ft Enter the wear amount W of brake shoe 4 f ,W ft The wear amount W of brake shoe 4 is estimated. f ,W ft As a result, when a vehicle 1B running on track T applies an arbitrary braking force, the braking start time t0 to the braking stop time t e Wear amount W of brake shoe 4 up to f The wear amount estimation unit 13 estimates the wear amount. When a vehicle 1B running on a track T applies an arbitrary braking force, the wear amount is calculated based on the time from the braking start time t0 to the braking stop time t e The wear amount (real-time wear amount) of the brake shoe 4 at a certain time t until ft The wear amount estimation unit 13 estimates the amount of wear.

[0104] The method and device for estimating the amount of wear of a friction material according to the second embodiment have the following advantages in addition to the advantages of the first embodiment. In this second embodiment, the wear amount W of the brake shoe 4 is calculated based on the amplitude of the AE signal output from the detection device 6A that detects the elastic wave emitted by the brake shoe 4 of the braking device 3B of the actual vehicle 1B. f ,W ft Therefore, when the brake device 3B of the vehicle 1B running on the track T applies a given braking force, the wear amount W of the brake shoe 4 of the brake device 3B on the vehicle 1B side is estimated. f ,W ft This can be estimated with high accuracy while the vehicle 1B is in actual operation without being affected by external disturbances such as wind when the vehicle 1B is running. [Example]

[0105] Next, an embodiment of the present invention will be described. In a bench test using a braking performance testing machine at the Railway Technical Research Institute, actual brake shoes were pressed against the actual wheels of the braking performance testing machine to estimate the amount of brake shoe wear. Synthetic brake shoes were used. An electronic balance was used to measure the amount of wear per braking operation when an emergency brake was applied once using the braking performance testing machine. The amount of wear was the actual measured value per braking operation when braking was performed three times each at initial braking speeds of 35 km / h, 65 km / h, and 95 km / h.

[0106] Figure 13 shows the results of measuring the amount of brake shoe wear when the emergency brake was applied once in a bench test. (A) is a graph showing an example of an exponential approximation formula that expresses the relationship between the amount of wear and the time integral value of the maximum amplitude of the AE signal in the example, and (B) is a graph of a general exponential approximation formula that shows the relationship between the initial braking speed and the amount of wear in the comparative example. The vertical axis in Figure 13(A) is the measured amount of wear [g], and the horizontal axis is the time integral value of the maximum amplitude of the AE signal [V·s]. The vertical axis in Figure 13(B) is the measured or estimated amount of wear [g], and the horizontal axis is the initial braking speed [km / h].

[0107] Example 1 shown in Figure 13(A) is a relational expression that expresses the relationship between the amount of wear and the time integral value of the maximum amplitude of the AE signal per emergency braking using an exponential approximation curve. Comparative Example 1 shown in Figure 13(B) is a general estimation expression that expresses the relationship between the amount of wear and the initial braking speed per emergency braking using an exponential approximation curve. Unlike Comparative Example 1, Example 1 is capable of converting the time integral value of the maximum amplitude of the AE signal into the amount of wear, regardless of the initial braking speed.

[0108] Next, the amount of wear per braking operation was measured using an electronic balance when the service brakes were applied once with a 7-notch brake performance tester. The amount of wear was measured once each at initial braking speeds of 35 km / h, 65 km / h, and 95 km / h.

[0109] Figure 14 shows the results of measuring the amount of brake shoe wear when the service brakes were applied once in a bench test with a 7-notch stroke. (A) is a graph showing an example of an exponential approximation formula that expresses the relationship between the amount of wear and the time integral of the maximum amplitude of the AE signal in the example, and (B) is a graph of a general exponential approximation formula that expresses the relationship between the initial braking speed and the amount of wear in the comparative example. The vertical axis in Figure 14(A) is the measured or estimated amount of wear [g], and the horizontal axis is the time integral of the maximum amplitude of the AE signal [V·s]. The vertical axis in Figure 14(B) is the measured or estimated amount of wear [g], and the horizontal axis is the initial braking speed [km / h].

[0110] Example 2 shown in Figure 14(A) is a relational expression that expresses the relationship between the amount of wear and the time integral value of the maximum amplitude of the AE signal per one braking operation of seven notches in service braking as an exponential approximation curve based on actual measurements. Example 3 is an estimation expression that corrects the exponential approximation curve during emergency braking by using the power of the pressing force ratio and the power of the initial speed ratio. Comparative Example 2 shown in Figure 14(B) is a general estimation expression that expresses the relationship between the amount of wear and the initial braking speed per one braking operation of seven notches in service braking as an exponential approximation curve based on actual measurements. Comparative Example 3 is an estimation expression that corrects the relationship between the amount of wear and the initial braking speed during emergency braking by using the pressing force ratio.

[0111] 14(A), the exponential approximation curve for the estimated wear amount in Example 3 is almost identical to the exponential approximation curve for the actually measured wear amount in Example 2, confirming that the wear amount can be estimated with high accuracy. On the other hand, the exponential approximation curve for the estimated wear amount in Comparative Example 3 does not match the exponential approximation curve for the actually measured wear amount in Comparative Example 3, confirming that the wear amount cannot be estimated with high accuracy using a general estimation formula.

[0112] FIG. 15 is a graph comparing the ratio (error) of the estimated results of brake shoe wear amount when the normal brake notch is 7 in a bench test at all initial speeds (35 km / h, 50 km / h, 65 km / h, 80 km / h, and 95 km / h). The vertical axis in FIG. 15 represents the ratio [%] of the estimated value to the actual measured value, and the horizontal axis represents the estimation conditions. As shown in FIG. 15, the ratios are 105% for Example 2, 103% for Example 3, 106% for Comparative Example 2, and 220% for Comparative Example 3. The closer the ratio of the actual measured value to the estimated value is to 100, the higher the accuracy of the wear amount estimation. Therefore, Example 3 has the highest accuracy. On the other hand, Comparative Examples 2 and 3 were confirmed to have low accuracy. In addition, since AE signals are not used, there is a drawback in that the wear amount cannot be estimated in real time. From the above, it was confirmed that Example 3 is the best method for estimating the wear amount.

[0113] FIG. 16 is a graph showing an example of the estimated results of the wear amount of the brake shoes. Figure 16 shows the estimation results when an emergency brake was applied with a pressing force of 25 kN at an initial braking speed of 95 km / h. The estimated wear amount increased as the maximum amplitude of the AE signal increased, confirming that it was possible to estimate the instantaneous and total wear amount of the brake shoe.

[0114] (Other embodiments) The present invention is not limited to the above-described embodiment, and various modifications and alterations are possible as described below, and these are also within the scope of the present invention. (1) In this embodiment, the brake devices 3, 3A, and 3B for railway vehicles have been described as examples, but the present invention can also be applied to brake devices for other means of transportation, such as automobiles, motorcycles, and bicycles. Furthermore, in this embodiment, the brake devices 3, 3A, and 3B have been described as tread brake devices. However, the present invention can also be applied to disc brake devices that generate braking force by pressing a friction material (brake lining) against a disk that rotates integrally with the axle, or rail brake devices that generate braking force by pressing a friction material directly against the top surface of the rail. Furthermore, in this embodiment, the brake devices 3, 3A, and 3B have been described as single-side brake shoe brakes. However, the present invention can also be applied to double-sided brake shoe brakes in which two brake shoes 4 press against the tread 2a of one wheel 2 so as to sandwich the tread 2a from the front and rear of the wheel 2.

[0115] (2) In this embodiment, the brake shoe 4 is described as an example of a friction material, but the present invention is not limited to the brake shoe 4. For example, the present invention can also be applied to friction materials such as brake linings that press against the brake disc of a disc brake device to generate braking force, abrasives that press against the tread 2a of a wheel 2 to remove rust and impurities from the tread 2a and clean the tread 2a or improve adhesion, contact strips of a current collector that slide against the trolley wire of an overhead power line, grounding brushes that dissipate power from a rotating body, tools that come into frictional contact with a workpiece, wheels and / or rails that come into frictional contact, and friction materials on the drive side and / or driven side of a clutch device that transmits power from the drive side to the driven side. Furthermore, in this embodiment, a case where one of multiple members in frictional contact is rotating and the other member is stationary is described as an example, but the present invention can also be applied to a case where both members in frictional contact are rotating. Furthermore, in this embodiment, an example has been described in which one AE sensor 6a is installed on the brake shoe 4, but the present invention can also be applied to cases in which multiple AE sensors 6a are installed on the brake shoe 4. [Explanation of symbols]

[0116] 1A Test stand 1B vehicle 1a Body 1b Cart 2 wheels 3, 3A, 3B Brake device 4 Brake shoe (friction material) 5. Wear estimation system 6, 6A, 6B Detector 7,7A,7B Wear amount estimation device 9 Maximum amplitude calculation section 10 Time integral value calculation section 11 Relational Expression Generation Section 12 Relational equation correction section 13 Wear estimation section t0 Braking start time t e Brake stop time t time W a Actual wear amount W0,W f Amount of wear W 0t ,W ft Wear amount (real-time wear amount) R0,R 0t Relational Expression R f ,R ft Corrected relational equation T track

Claims

1. A method for estimating wear amount of a friction material, which estimates wear amount of a friction material in frictional contact, comprising: a wear amount estimation step of estimating the wear amount of the friction material based on the amplitude of an output signal output by a detection device that detects elastic waves emitted by the friction material; A method for estimating the amount of wear of a friction material, comprising:

2. 2. The method for estimating wear amount of a friction material according to claim 1, the wear amount estimation step includes a step of estimating the wear amount of the friction material based on a relational expression that expresses a relationship between a time integral value of a maximum amplitude of an output signal output by the detection device and the wear amount of the friction material; A method for estimating the amount of wear of a friction material, comprising:

3. 2. The method for estimating wear amount of a friction material according to claim 1, the wear amount estimation step includes a step of estimating the wear amount of the friction material from a braking start time to a braking stop time when an arbitrary braking force is applied; A method for estimating the amount of wear of a friction material, comprising:

4. 2. The method for estimating wear amount of a friction material according to claim 1, the wear amount estimation step includes a step of estimating the wear amount of the friction material at a certain time from a braking start time to a braking stop time when an arbitrary braking force is applied; A method for estimating the amount of wear of a friction material, comprising:

5. 2. The method for estimating wear amount of a friction material according to claim 1, the wear amount estimation step includes a step of estimating the wear amount of the friction material when an arbitrary braking force is applied, based on an exponential approximation equation that expresses the relationship between the time integral value of the maximum amplitude of the output signal output by the detection device from the braking start time to the braking stop time when the maximum braking force is applied, and the wear amount of the friction material from the braking start time to the braking stop time; A method for estimating the amount of wear of a friction material, comprising:

6. 6. The method for estimating wear amount of a friction material according to claim 5, the wear amount estimation step includes a step of estimating the wear amount of the friction material based on a pressing force ratio, which is the ratio of the pressing force when an arbitrary braking force is applied to the pressing force when a maximum braking force is applied, an initial speed ratio, which is the ratio of the speed when an arbitrary braking force is applied to the speed when the maximum braking force is applied, a coefficient of the power of these ratios, and the exponential approximation formula; A method for estimating the amount of wear of a friction material, comprising:

7. 2. The method for estimating wear amount of a friction material according to claim 1, the wear amount estimation step estimates the wear amount of the brake shoe based on the amplitude of an output signal output by a detection device that detects elastic waves emitted by the brake shoe of the brake device of the test stand; A method for estimating the amount of wear of a friction material, comprising:

8. 2. The method for estimating wear amount of a friction material according to claim 1, the wear amount estimation step estimates the wear amount of the brake shoe based on the amplitude of an output signal output by a detection device that detects elastic waves emitted by the brake shoe of a brake device of an actual vehicle; A method for estimating the amount of wear of a friction material, comprising:

9. A friction material wear amount estimation device that estimates the wear amount of a friction material that is in frictional contact, comprising: a wear amount estimation unit that estimates the wear amount of the friction material based on the amplitude of an output signal output by a detection device that detects elastic waves emitted by the friction material; A friction material wear amount estimation device characterized by the above.

Images