Tool and method for detecting overall impact strength of brake pad friction block of high-speed train

Abstract

The invention discloses a tool and method for detecting the overall impact strength of a high-speed train brake pad friction block, and belongs to the technical field of powder metallurgy brake pad friction block quality detection.The detection tool comprises a fixing device used for clamping the friction block and a pendulum bob used for applying impact force to the friction block; the fixing device comprises a base mounted on an object placing table of the impact testing machine and a pressing block capable of fixing the friction block on the base; the base and the pressing block are connected through a bolt to press and fix the base body rod of the friction block. The friction block is propped through the mounting surface on the base; the pendulum bob is mounted on a swing rod of the impact testing machine; the detection method comprises the steps of base installation, pendulum bob installation, friction block installation, impact strength testing and the like. According to the method, the problem that the bearing capacity of the high-speed train brake pad friction block has no risk assessment index when the friction block is subjected to the impact load under the extreme working condition is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of powder metallurgy friction block detection, in particular to a tool and method for detecting the overall impact strength of a high-speed train brake pad friction block. Background Art

[0002] At present, the main strength testing items for high-speed train brake pad friction blocks are: shear strength of the friction body, shear strength of the bonding surface between the friction body and the substrate, and compressive strength of the friction body.

[0003] Shear strength refers to a material's maximum ability to resist shear failure under shear stress. It is used to assess a material's stability and durability when subjected to shear forces. Testing the shear strength of the friction body and the shear strength of the bond between the friction body and the substrate of high-speed train brake pads primarily assesses the ability of the pad to resist radial friction forces acting on the friction body itself and at the junction of the friction body and the backing plate (substrate) during friction braking.

[0004] Compressive strength refers to a material's ability to withstand vertical pressure without collapsing. It assesses the maximum stress a material can withstand under compressive loads. High-speed train brake pad compressive strength testing primarily assesses the ability of the friction element of the friction pad to resist the axial clamping pressure exerted by the brake caliper during friction braking.

[0005] The above two strength tests of shear strength and compressive strength mainly evaluate the stability and reliability of the friction blocks of high-speed train brake pads when they withstand friction and braking pressure under normal driving and braking conditions. However, high-speed trains may also encounter some extreme working conditions during operation, such as emergency braking, impact with foreign objects (such as stones), etc. The friction blocks may be subjected to a large impact load instantaneously. The current friction block strength test project lacks an evaluation indicator for the bearing capacity of the friction blocks when subjected to impact loads.

[0006] Impact strength refers to the maximum stress a material can withstand without breaking when subjected to an impact. Impact testing can assess a material's strength under the impact loads it might encounter in real-world applications. This is crucial for evaluating a material's reliability and safety under impact. Impact strength testing can be used as an indicator to assess the ability of a high-speed train brake pad friction block to withstand impact loads under extreme operating conditions.

[0007] Therefore, it is necessary to provide a tool and method for detecting the impact strength of the friction block of a high-speed train brake pad to realize the detection of the impact strength of the friction block. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a tool and method for detecting the overall impact strength of the friction block of the brake pad of a high-speed train, which solves the problem of the lack of risk assessment indicators for the bearing capacity of the friction block of the brake pad of a high-speed train when the friction block is subjected to impact load under extreme working conditions. It is very important for evaluating the reliability and safety of the friction block when it is subjected to impact.

[0009] In order to solve the above technical problems, the technical solution adopted by the present invention is: A tool for testing the overall impact strength of a high-speed train brake pad friction block, comprising a fixing device for clamping the friction block and a pendulum that applies impact force to the friction block; the fixing device comprises a base mounted on a storage platform of an impact testing machine and a pressure block capable of fixing the friction block to the base; the base and the pressure block are connected by bolts to press and fix the base rod of the friction block; the friction block is then supported by the mounting surface on the base; and the pendulum is mounted on the pendulum arm of the impact testing machine.

[0010] A further improvement of the technical solution of the present invention is that: the pendulum includes a corner-shaped pendulum body and a pad arranged at a vulnerable impact portion of the pendulum body; the pendulum body and the pad are fastened by bolts.

[0011] A further improvement of the technical solution of the present invention is that: the upper corner of the pendulum body is the installation surface, the plane inside the middle part is the impact surface, and the back is the counterweight surface; the pad is installed on the side of the impact surface, and can be replaced when the pad is deformed by impact.

[0012] A further improvement of the technical solution of the present invention is that the outer edge of the cushion block protrudes 1mm-3mm beyond the outer edge of the pendulum body.

[0013] A further improvement of the technical solution of the present invention is that: the counterweight surface of the pendulum body is provided with a plurality of threaded holes.

[0014] A further improvement of the technical solution of the present invention is that: a mounting inclined surface capable of fixing the base on the storage table of the impact testing machine is provided on one side of the base; a positioning step capable of positioning the base on the storage table of the impact testing machine is provided on the other side of the base; a base support step is provided on the mounting surface of the base for mounting the friction block; a slot for inserting the base rod of the friction block is also provided on the mounting surface of the base for mounting the friction block; a chamfer is provided on the outside of the slot to enable the friction block to be tightly attached to the base; and a threaded countersunk hole for bolting the pressure block is also provided on the base.

[0015] A further improvement of the technical solution of the present invention is that the height of the base support step is smaller than the base thickness of the friction block by 0.5 mm to 1 mm.

[0016] A further improvement of the technical solution of the present invention is that: a groove for fixing the base rod of the friction block is provided on the pressure block; a through hole for the bolt to pass through is provided on one side of the upper end of the groove; the groove and the slot on the base form a mounting hole for mounting the base rod of the friction block.

[0017] A further improvement of the technical solution of the present invention is that the material of the fixing device and the pendulum are both die steel with a heat treatment hardness of 55HRC-62HRC.

[0018] A method for detecting the overall impact strength of a high-speed train brake pad friction block comprises the following steps: Step 1: Install the base: Place the base on the impact tester's storage table, position the step close to the inner wall of the impact position of the impact tester, press the inclined pressure block provided by the impact tester on the installation slope of the base, and tighten the inclined pressure block provided by the impact tester with bolts to complete the installation of the base; Step 2. Pendulum installation: Tighten the pad and pendulum body with bolts. The outer edge of the pad should protrude 1mm to 3mm from the outer edge of the pendulum body. Then install the pendulum on the pendulum rod connection fixture of the impact tester and tighten it with bolts. Step 3, install the friction block; insert the base rod of the friction block into the slot of the base, move the pendulum to align the impact surface of the pendulum with a straight side wall of the friction block, tighten the bolts to press the pressure block tightly, so that the mounting hole hugs the base rod of the friction block, and complete the installation of the friction block; Step 4, impact strength test: operate the impact testing machine, take the pendulum and swing, then withdraw the pin and impact in sequence, the pendulum swings down, the system energy is converted from potential energy to kinetic energy, the pendulum impacts the friction block at the lowest point and then continues to swing up, the system energy is converted from kinetic energy to potential energy again, the pendulum records the system energy loss after the pendulum impacts and works by fiddling with the pointer on the dial of the equipment, and the impact strength test is completed. The energy loss of the impact testing machine during the impact process is calculated or read through the dial value, which is the overall impact strength value of the friction block.

[0019] Due to the adoption of the above technical solution, the technical advancements achieved by the present invention are: 1. This invention proposes a concept for testing the impact strength of high-speed train brake pad friction blocks. By providing a fixing device to mount the friction block on the loading platform of an impact testing machine, and by providing a corner-shaped pendulum, the friction block can be subjected to an impact test. This addresses the lack of an evaluation indicator in the current industry standard for the bearing capacity of high-speed train brake pad friction blocks under impact loads under extreme working conditions. This is of great significance for evaluating the reliability and safety of high-speed train brake pad friction blocks under extreme working conditions. 2. The present invention provides a tool and method for detecting the overall impact strength of the brake pad friction block of a high-speed train, which can accurately detect the overall impact strength of the brake pad friction block of a high-speed train.

[0020] 3. The present invention has made an innovative design for the pendulum of the impact detection equipment: the impact part of the pendulum is designed to be a plane, located on the side of the middle part of the pendulum, which can be suitable for impact strength testing of different types of friction blocks; a replaceable pad is set at the vulnerable part of the pendulum, and when the impact part is deformed due to long-term use, the pad can be replaced, avoiding the replacement of the entire pendulum, extending the service life of the pendulum and reducing costs; after the pad and the pendulum body are installed, the outer edge of the pad protrudes more than the outer edge of the pendulum body, avoiding scratches between the pendulum body and the sample residue after impact, which affects the test results; a number of threaded holes are set on the back of the pendulum impact surface, and the pendulum can be counterweighted according to the impact requirements of friction blocks of different sizes, thereby increasing the scope of application of the pendulum. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive efforts. Figure 1 Schematic diagram of the overall structure of a tool for testing the overall impact strength of a high-speed train brake pad friction block provided in an embodiment of the present invention; Figure 2 is a front view of a fixing device according to an embodiment of the present invention; Figure 3 is a front view of a base in an embodiment of the present invention; Figure 4 is a top view of the base in an embodiment of the present invention; Figure 5 is a left side view of the base in an embodiment of the present invention; Figure 6 1 is a front view of a pressing block according to an embodiment of the present invention; Figure 7 It is a left side view of the pressing block in the embodiment of the present invention; Figure 8 is a front view of a pendulum in an embodiment of the present invention; Figure 9 is a left side view of the pendulum in an embodiment of the present invention; Figure 10 is a front view of the pendulum body in an embodiment of the present invention; Figure 11 is a top view of the pendulum body in an embodiment of the present invention; Figure 12 1 is a left side view of the pendulum body according to an embodiment of the present invention; Figure 13 is a right side view of the pendulum body in an embodiment of the present invention; Figure 14 is a front view of a spacer block according to an embodiment of the present invention; Among them: 1. Fixing device; 11. Base; 111. Base support step; 112. Positioning step; 113. Mounting slope; 114. Threaded countersunk hole; 115. Chamfer; 12. Pressing block; 121. Groove; 122. Through hole; 13. Mounting hole; 2. Pendulum; 21. Pendulum body; 211. Threaded hole; 22. Pad; 3. Friction block. DETAILED DESCRIPTION

[0022] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or are inherent to these processes, methods, products or apparatuses.

[0023] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "several" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments: like Figure 1As shown, a tool for testing the overall impact strength of the friction block of a high-speed train brake pad includes a fixing device 1 for clamping the friction block 3 and a pendulum 2 for applying an impact force to the friction block 3; the fixing device 1 includes a base 11 mounted on a storage table of an impact testing machine and a pressure block 12 capable of fixing the friction block 3 on the base; the base 11 and the pressure block 12 are connected by bolts to press and fix the base rod of the friction block 3; the friction block 3 is then supported by the mounting surface on the base 11; the pendulum 2 is installed on the pendulum rod of the impact testing machine.

[0026] Friction block 3 is a high-speed train brake pad friction block. Its base is a regular hexagon with a base rod on one side and a spherical arc portion at the connection between the base and the rod. The impact testing machine's storage platform includes two parallel platforms. Friction block 3 is fixed to one platform using a fixing device 1. Friction block 3 is located between the two parallel platforms. When the pendulum 2 falls, the impact surface contacts a straight side wall of friction block 3.

[0027] Further, such as Figure 2 、 Figure 3 、 Figure 4 and Figure 5 As shown, a mounting bevel 113 is provided on one side of the base 11 to secure the base 11 to the platform of the impact testing machine; a positioning step 112 is provided on the other side of the base 11 to position the base 11 on the platform of the impact testing machine; a base support step 111 is provided on the mounting surface of the base 11 for mounting the friction block 3; a slot for inserting the base rod of the friction block 3 is also provided on the mounting surface of the base 11 for mounting the friction block 3; a chamfer 115 is provided on the outside of the slot to enable the friction block 3 to be tightly attached to the fixing device 1; and a threaded countersunk hole 114 is also provided on the base 11 for bolting the pressure block 12 (a threaded countersunk hole is a hole with a thread inside, not a through hole, and is used to install the bolts used to fix the pressure block 2). The function of the chamfer 115 is to avoid the root of the spherical arc of the friction block base, so that the friction block 3 is tightly attached to the base 11.

[0028] Specifically, the structural setting of the base 11 is to facilitate fixing the friction block 3 on the storage table of the impact testing machine. Its structure needs to match the structure of the storage table of the impact testing machine, and at the same time it must match the structure of the friction block 3, and it must also ensure that the pendulum 2 can perform impact testing on the friction block 3.

[0029] Further, such as Figure 4 As shown, the height of the base supporting step 111 is smaller than the base thickness of the friction block 3 by 0.5 mm to 1 mm.

[0030] Further, such as Figure 6 、 Figure 7As shown, the pressing block 12 is provided with a groove 121 for fixing the base rod of the friction block 3; a through hole 122 for a bolt to pass through is provided on one side of the upper end of the groove 121 (the through hole is not provided with an internal thread, and is only for the bolt to pass through to fix the pressing block 12. The pressing block 12 is tightened by the bolt and then presses the base rod of the friction block 3); the groove 121 and the groove on the base 11 form a mounting hole 13 for mounting the base rod of the friction block 3.

[0031] Specifically, the pressing block 12 is provided to fix the friction block 3 on the base 11 .

[0032] Further, such as Figure 8 、 Figure 9 As shown, the pendulum 2 includes a corner-shaped pendulum body 21 and a pad 22 provided at a vulnerable impact portion of the pendulum body 21 ; the pendulum body 21 and the pad 22 are fastened by bolts.

[0033] Further, such as Figure 10 、 Figure 11 、 Figure 12 、 Figure 13 and Figure 14 As shown, the top of the upper corner of the pendulum body 21 serves as the mounting surface, the flat surface inside the middle portion serves as the impact surface, and the back serves as the counterweight surface. Pads 22 are mounted to the side of the impact surface and can be replaced after deformation. The shape of the pendulum 2 is designed for weight considerations (the upper and lower corners are designed to increase weight); secondly, for the center of gravity, which is near the mounting location of the friction block 3 at the moment of impact; and thirdly, to prevent contact between the non-impact portion of the pendulum 2 and the friction block 3 during the impact.

[0034] Specifically, the mounting surface of the pendulum body 21 (the top of the upper corner) is fixedly connected to the pendulum arm of the impact testing machine via several bolts. The impact surface of the pendulum body 21 is located in the middle and inner side of the area connecting the upper and lower corners. The back surface (the counterweight surface) of the pendulum body 21 is parallel to the impact surface (including the back surface of the upper corner, the back surface of the impact surface, and the back surface of the lower corner). The upper corner is longer than the lower corner, and the upper and lower corners are arranged parallel to each other; both the upper and lower corners are arranged perpendicular to the impact surface.

[0035] Further, such as Figure 10 As shown, the outer edge of the pad 22 protrudes 1mm-3mm from the outer edge of the pendulum body 21 to prevent the pendulum body 21 from scratching the residual material of the sample after impact.

[0036] Further, such as Figure 13 As shown, the counterweight surface of the pendulum body 21 is provided with a plurality of threaded holes 211 , and a counterweight block can be installed on the counterweight surface of the pendulum body 21 by bolts to counterweight the pendulum 2 as required.

[0037] Furthermore, the material of the fixing device 1 and the pendulum 2 are both die steel, and the heat treatment hardness is 55HRC-62HRC.

[0038] A method for testing the overall impact strength of a high-speed train brake pad friction block, using the above-mentioned tooling for testing the overall impact strength of a high-speed train brake pad friction block, comprises the following steps: Step 1, install the base 11: Place the base 11 on the storage table of the impact tester, position the step 112 against the inner wall of the impact position of the impact tester, press the inclined pressure block provided by the impact tester on the installation inclined surface 113 of the base 11 with the inclined pressure block provided by the impact tester, and tighten the inclined pressure block provided by the impact tester with bolts to complete the installation of the base 11; Step 2, Pendulum 2 Installation: Tighten the pad 22 and the pendulum body 21 with bolts. The outer edge of the pad 22 protrudes 1mm to 3mm from the outer edge of the pendulum body 21. Then install the pendulum 2 on the pendulum rod connection fixture of the impact tester and tighten it with bolts. Step 3, install the friction block 3; insert the base rod of the friction block 3 into the slot of the base 11, move the pendulum 2 to fit the pendulum impact surface with a straight side wall of the friction block 3, tighten the bolts to press the pressure block 12, so that the mounting hole 13 holds the base rod of the friction block tightly, and complete the installation of the friction block 3; Step 4, impact strength test: operate the impact testing machine, take out the pendulum 2, and then withdraw the pin and impact in sequence. The pendulum 2 swings down, and the system energy is converted from potential energy to kinetic energy. When the pendulum 2 is at the lowest point, it impacts the friction block 3 and does work. Then the pendulum 2 continues to swing up, and the system energy is converted from kinetic energy to potential energy again. The pendulum rod records the system energy loss after the pendulum 2 impacts and does work by fiddling with the pointer on the dial of the equipment. The impact strength test is completed. The energy loss of the system during the impact process is calculated or read through the dial value, which is the overall impact strength value of the friction block 3.

[0039] In summary, the present invention proposes a concept for testing the impact strength of high-speed train brake pad friction blocks, and at the same time provides a testing tool and a testing method for the overall impact strength of high-speed train brake pad friction blocks, which can realize accurate testing of the overall impact strength of high-speed train brake pad friction blocks, and make up for the lack of evaluation indicators in the current industry standards for the bearing capacity of high-speed train brake pad friction blocks when subjected to impact loads under extreme working conditions. It is of great significance for evaluating the reliability and safety of high-speed train brake pad friction blocks when subjected to impact under extreme working conditions.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A tool for testing the overall impact strength of high-speed train brake pad friction blocks, characterized by: The invention comprises a fixing device (1) for clamping a friction block (3) and a pendulum (2) for applying an impact force to the friction block (3); the fixing device (1) comprises a base (11) mounted on a storage table of an impact testing machine and a pressure block (12) capable of fixing the friction block (3) on the base (11); the base (11) and the pressure block (12) are connected by bolts to press and fix the base rod of the friction block (3); the friction block (3) is then supported by the mounting surface on the base (11); and the pendulum (2) is mounted on the pendulum rod of the impact testing machine.

2. The detection tool according to claim 1, characterized in that: The pendulum (2) comprises a corner-shaped pendulum body (21) and a cushion block (22) arranged at a vulnerable impact portion of the pendulum body (21); the pendulum body (21) and the cushion block (22) are fastened by bolts.

3. The detection tool according to claim 2, characterized in that: The upper corner of the pendulum body (21) is a mounting surface, the inner plane of the middle part is an impact surface, and the back surface is a counterweight surface; the pad (22) is installed on the side of the impact surface, and the pad (22) can be replaced when it is deformed by impact.

4. The detection tool according to claim 3, characterized in that: The outer edge of the cushion block (22) protrudes 1 mm to 3 mm from the outer edge of the pendulum body (21).

5. The detection tool according to claim 3, characterized in that: The counterweight surface of the pendulum body (21) is provided with a plurality of threaded holes (211).

6. The detection tool according to claim 1, characterized in that: A mounting bevel (113) capable of fixing the base (11) on a storage table of an impact testing machine is provided on one side of the base (11); a positioning step (112) capable of positioning the base (11) on the storage table of an impact testing machine is provided on the other side of the base (11); a base supporting step (111) is provided on the mounting surface of the base (11) for mounting the friction block (3); a slot for inserting a base rod of the friction block (3) is also provided on the mounting surface of the base (11) for mounting the friction block (3); a chamfer (115) capable of making the friction block (3) close to the base (11) is provided on the outer side of the slot; and a threaded countersunk hole (114) for fixing the pressure block (12) with a bolt is also provided on the base (11).

7. The detection tool according to claim 6, characterized in that: The height of the base support step (111) is 0.5 mm to 1 mm less than the base thickness of the friction block (3).

8. The detection tool according to claim 1, characterized in that: The pressure block (12) is provided with a groove (121) for fixing the base rod of the friction block (3); a through hole (122) for a bolt to pass through is provided on one side of the upper end of the groove (121); the groove (121) and the clamping groove on the base (11) form a mounting hole (13) for mounting the base rod of the friction block (3).

9. The detection tool according to claim 1, characterized in that: The fixing device (1) and the pendulum (2) are both made of die steel, and the heat treatment hardness is 55HRC-62HRC.

10. A method for testing the overall impact strength of a high-speed train brake pad friction block, using the testing tool according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1, installation of the base (11): Place the base (11) on the impact tester storage table, position the step (112) close to the inner wall of the impact position of the impact tester, press the inclined pressure block of the impact tester on the installation inclined surface (113) of the base (11), and tighten the inclined pressure block of the impact tester with bolts to complete the installation of the base (11); Step 2, installation of the pendulum (2): tighten the pad (22) and the pendulum body (21) with bolts, with the outer edge of the pad (22) protruding 1mm to 3mm from the outer edge of the pendulum body (21). Then, install the pendulum (2) on the pendulum rod connecting fixture of the impact testing machine and tighten it with bolts; Step 3, install the friction block (3); insert the base rod of the friction block (3) into the slot of the base (11), move the pendulum (2) to make the pendulum impact surface fit with a straight side wall of the friction block (3), tighten the bolt to press the pressure block (12), so that the mounting hole (13) holds the friction block base rod tightly, and complete the installation of the friction block; Step 4, impact strength test: operate the impact tester, take the pendulum (2) and then withdraw the pin and impact in sequence. The pendulum (2) swings down, and the system energy is converted from potential energy to kinetic energy. The pendulum (2) impacts the friction block (3) at the lowest point and then the pendulum (2) continues to swing up. The system energy is converted from kinetic energy to potential energy again. The pendulum records the system energy loss after the pendulum (2) impacts and works by fiddling with the pointer on the dial of the device. The impact strength test is completed. The energy loss of the impact tester during the impact process is calculated or read through the dial value, which is the overall impact strength value of the friction block (3).

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