A friction and wear test device for a microstructure array of porous materials under time-varying loads

Abstract

The present invention relates to a friction and wear test device for a microstructure array of a porous material under a time-varying load, belonging to the field of detection equipment. It includes a flexible matrix, a connecting plate, a pin fixture, a piezoelectric stack, and a capacitive displacement sensor. The piezoelectric stack is connected to the straight-beam flexible hinge on the flexible matrix through a pre-tightening bolt. The straight circular flexible hinge is driven by the piezoelectric stack, and a symmetric arrangement is adopted, with the horizontal and vertical mechanisms being the same. The advantages are novel structure, convenient use and installation. Based on a certain load of a friction and wear testing machine, the micron-level high-frequency vibration of the pin can be realized by changing the piezoelectric signal, so as to realize the friction and wear test of the porous material microstructure array under complex working conditions such as simulated multi-load coupling and time-varying load. By using the pin and the pin fixture, the installation and disassembly of the sample pin are convenient, the structure is simple, and the applicability is strong, which is suitable for most current friction and wear testing machines.

Description

Technical Field

[0001] The present invention belongs to the field of detection devices, and particularly relates to a friction and wear test device for a microstructural array of porous materials under time-varying loads. Background Art

[0002] Due to the large number of connected or closed pore structures uniformly distributed inside porous materials, they have advantages such as low relative density, good permeability, and high energy absorption rate compared to conventional continuous media. With the development of modern industry, metal materials can also form pore structures like polymers. Therefore, metal porous materials can be used as buffer energy-absorbing and sound-absorbing and noise-reducing materials in some dynamic light-load or static no-load working conditions. However, the mechanical properties of metal porous materials are poorer than those of dense materials of the same volume. As the porosity increases, the yield strength of porous materials decreases exponentially, and this defect will limit their application as noise-reducing materials in many usage scenarios with higher load-bearing requirements.

[0003] A microstructural array refers to a surface with special functions regularly distributed with a certain structure as a unit. The friction-reducing practices of many microstructural arrays of organisms in nature can guide the optimization practices of modern industrial products. For example, the fine-tooth microstructures on the shark skin surface have the effects of reducing water flow resistance and friction; the convex hull array microstructures on the beetle head have the effects of detaching soil particles and reducing wear. Therefore, the wear-resistant and drag-reducing performance of the surface layer with a certain thickness of porous materials can be strengthened by modifying the microstructural array, so as to realize the drag-reducing and noise-reducing optimization application of porous materials to the rubbing plane under complex working conditions. To explore the application prospects of the microstructural array of porous materials, it is necessary to be based on the friction and wear test results under simulated actual working conditions.

[0004] At present, the research on the friction and wear characteristics of the microstructural array of porous materials still mainly uses traditional testing machines, which are usually classified into four-ball friction and wear testing machines, ring-block friction and wear testing machines, end-face friction and wear testing machines, vertical universal friction and wear testing machines, etc. according to their uses. Generally, the working principle of traditional testing machines is: fixing the sample or making it rotate, and rubbing against the counterface at a rated speed under a certain load, and evaluating the wear resistance of the sample by real-time monitoring of the sample removal amount or the output torque of the main shaft. This conventional testing method with a single constant load cannot meet the feasibility study of the drag-reducing and noise-reducing application of the microstructural array of porous materials to the rubbing plane under complex working conditions such as multi-load coupling and time-varying loads. Summary of the Invention

[0005] The present invention provides a friction and wear test device for a microstructural array of porous materials under time-varying loads to solve the problem that a conventional friction and wear testing machine with a single constant load cannot simulate the friction environment of the microstructural array of porous materials under complex working conditions such as multi-load coupling and time-varying loads.

[0006] The technical solution adopted by the present invention is as follows: The capacitive displacement sensor 1 is fixedly connected to the connecting plate through the mounting plate, the connecting plate is fixedly connected to the flexible matrix, the piezoelectric stack 1 is fixedly connected to the straight-beam flexible hinge 1 of the flexible matrix through the pre-tightening bolt. The head of the piezoelectric stack is embedded in the front straight-beam flexible hinge 1, and the tail is embedded in the straight-beam flexible hinge 2. The other side of the straight-beam flexible hinge 2 is connected to the pin fixture, and the displacement measurement baffle 1 is fixedly connected to the pin fixture. The probe of the capacitive displacement sensor 1 is aligned with the displacement measurement baffle 1. The capacitive displacement sensor 2 is fixedly connected to the flexible matrix through the mounting plate, and the piezoelectric stack 2 is fixedly connected to the straight-beam flexible hinge 3 of the flexible matrix through the pre-tightening bolt. The head of the piezoelectric stack 2 is embedded in the front straight-beam flexible hinge 3, and the tail is embedded in the straight-beam flexible hinge 4. The other side of the straight-beam flexible hinge 4 is connected to the pin fixture, the displacement measurement baffle 2 is fixedly connected to the displacement measurement baffle 1, and the probe of the capacitive displacement sensor 2 is aligned with the displacement measurement baffle 2. The pin is fixed in the pin fixture.

[0007] The flexible matrix of the present invention is an integral structure. The two ends of the straight-beam flexible hinge 1 are respectively connected to the frame of the flexible matrix through the straight-round flexible hinge 1, the straight-round flexible hinge 2, the straight-round flexible hinge 3, and the straight-round flexible hinge 4. The two ends of the straight-beam flexible hinge 2 are respectively connected to the frame of the flexible matrix through the straight-round flexible hinge 5, the straight-round flexible hinge 6, the straight-round flexible hinge 7, and the straight-round flexible hinge 8. The two ends of the straight-beam flexible hinge 3 are respectively connected to the frame of the flexible matrix through the straight-round flexible hinge 9, the straight-round flexible hinge 10, the straight-round flexible hinge 11, and the straight-round flexible hinge 12. The two ends of the straight-beam flexible hinge 4 are respectively connected to the frame of the flexible matrix through the straight-round flexible hinge 13, the straight-round flexible hinge 14, the straight-round flexible hinge 15, and the straight-round flexible hinge 16.

[0008] The pin fixture of the present invention includes a bolt, a spring, a small ball, and a body. The spring and the small ball are located in the body, and the bolt is threadedly connected to the body.

[0009] The advantages of the present invention are novel structure, convenient use and installation. Based on a certain load of the friction and wear testing machine, the high-frequency vibration of the pin at the micron level can be realized by changing the piezoelectric signal, so as to realize the friction and wear test of the porous material micro-structure array under complex working conditions such as simulated multi-load coupling and time-varying load. By adopting the pin and the pin fixture, the sample pin is convenient to install and disassemble, the structure is simple, and the applicability is strong, which is suitable for most of the current friction and wear testing machines. Description of the Drawings

[0010] Figure 1 is the structural schematic diagram of the present invention;

[0011] Figure 2 is the schematic diagram of the pin and the porous material micro-structure array test ring of the present invention;

[0012] Figure 3 is the schematic diagram of the friction motion principle of the present invention;

[0013] Figure 4 is Figure 1 the rear axonometric drawing of

[0014] Figure 5 is the schematic structural diagram of the flexible matrix of the present invention without the frame;

[0015] Figure 6 is the schematic structural diagram of the pin and the pin clamp of the present invention;

[0016] Figure 7 is the schematic diagram of the installation and use of the present invention. Specific embodiments

[0017] As Figure 1 , 4 , as shown in Figure 5, the capacitive displacement sensor 1-4 is fixedly connected to the connecting plate 2 through the mounting plate 6, the connecting plate 2 is fixedly connected to the flexible matrix 1, the piezoelectric stack 1-11 is fixedly connected to the straight-beam flexible hinge 1-3 of the flexible matrix 1 through the pre-tightening bolt 5, the head of the piezoelectric stack 11 is embedded in the front straight-beam flexible hinge 1-3, the tail is embedded in the straight-beam flexible hinge 2-30, the other side of the straight-beam flexible hinge 2-30 is connected to the pin clamp 7, the displacement measurement baffle 1-9 is fixedly connected to the pin clamp 7, and the probe of the capacitive displacement sensor 1-4 is aligned with the displacement measurement baffle 1-9; the capacitive displacement sensor 2-15 is fixedly connected to the flexible matrix 1 through the mounting plate, the piezoelectric stack 2-12 is fixedly connected to the straight-beam flexible hinge 3-32 of the flexible matrix 1 through the pre-tightening bolt, the head of the piezoelectric stack 2-12 is embedded in the front straight-beam flexible hinge 3-32, the tail is embedded in the straight-beam flexible hinge 4-31, the other side of the straight-beam flexible hinge 4-31 is connected to the pin clamp 7, the displacement measurement baffle 2-10 is fixedly connected to the displacement measurement baffle 1-9, the probe of the capacitive displacement sensor 2-15 is aligned with the displacement measurement baffle 2-10, and the pin 8 is fixed in the pin clamp 7.

[0018] The flexible substrate 1 is of an integral structure. Both ends of the straight-beam flexible hinge 1-3 are connected to the frame of the flexible substrate 1 through the straight-round flexible hinge 1-26, the straight-round flexible hinge 1-27, the straight-round flexible hinge 1-28, and the straight-round flexible hinge 1-29 respectively. Both ends of the straight-beam flexible hinge 2-30 are connected to the frame of the flexible substrate 1 through the straight-round flexible hinge 1-22, the straight-round flexible hinge 1-23, the straight-round flexible hinge 1-24, and the straight-round flexible hinge 1-25 respectively. These 4 pairs of flexible hinges provide displacement for the horizontal movement of the pin, that is, the Y-direction movement. Both ends of the straight-beam flexible hinge 3-32 are connected to the frame of the flexible substrate 1 through the straight-round flexible hinge 1-13, the straight-round flexible hinge 1-14, the straight-round flexible hinge 1-16, and the straight-round flexible hinge 1-17 respectively. Both ends of the straight-beam flexible hinge 4-31 are connected to the frame of the flexible substrate 1 through the straight-round flexible hinge 1-18, the straight-round flexible hinge 1-19, the straight-round flexible hinge 1-20, and the straight-round flexible hinge 1-21 respectively. These 4 pairs of flexible hinges provide displacement for the vertical movement of the pin, that is, the Z-direction movement.

[0019] As Figure 6 shown, the pin fixture 7 includes a bolt 701, a spring 702, a small ball 703, and a body 704. The spring 702 and the small ball 703 are located in the body 704. The bolt 701 is threadedly connected to the body 704. A groove for mating with the small ball is formed on the top side of the pin 8.

[0020] As Figure 7 , when performing the pin-on-disc friction and wear experiment, a friction and wear testing machine 33 is used. The entire flexible substrate 1 of the present invention is fixed on the Z-axis guide rail of the friction and wear testing machine with bolts. The porous material micro-structure array test ring 34 is connected to the main spindle box 36 of the friction and wear testing machine through the test ring fixture part 35. The pin 8 is inserted into the pin fixture 7.

[0021] The friction and wear testing machine 33 is turned on and the rotation speed, load, and other limiting conditions are set. The main spindle box 36 gives a signal to the main spindle, and the main spindle feeds in the positive direction of the Z-axis until it contacts the pin 8, as Figure 2 shown. After contact, the main spindle drives the porous material micro-structure array test ring 34 to friction with the pin 8. At the same time, an encoder capable of detecting the rotation angle of the main spindle is installed at the rear end of the main spindle. The rotation signal of the main spindle detected by the encoder is respectively transmitted to the numerical control system of the friction and wear testing machine 33 and the controller of the present invention (abbreviated as the time-varying load device), as Figure 3 shown.

[0022] The controller of the time-varying load device makes the movements of the pin 8 in the Z-direction and the Y-direction both take the main spindle encoder signal as the reference instead of time for movement, so that all movements are synchronized under the same reference.

[0023] The pin 8 realizes high-frequency vibration on the basis of a certain load friction with the surface of the porous material microstructure array test ring 34, ensuring the repeatability of the applied instantaneous load. Different from the traditional friction and wear testing machine that can only apply a fixed load, the time-varying load device can obtain data such as the friction coefficient and wear amount under the simultaneous application of a fixed load and an instantaneous load. The results obtained in this way provide an accurate data basis for obtaining the optimal value of the porous material microstructure array size.

Claims

1. A friction and wear test device for a microstructure array of porous materials with time-varying loads, characterized in that: The capacitive displacement sensor 1 is fixedly connected to the connecting plate through the mounting plate, the connecting plate is fixedly connected to the flexible matrix, the piezoelectric stack 1 is fixedly connected to the straight-beam flexible hinge 1 of the flexible matrix through the pre-tightening bolt. The head of the piezoelectric stack is embedded in the front straight-beam flexible hinge 1, and the tail is embedded in the straight-beam flexible hinge 2. The other side of the straight-beam flexible hinge 2 is connected to the pin fixture, and the displacement measurement baffle 1 is fixedly connected to the pin fixture. The probe of the capacitive displacement sensor 1 is aligned with the displacement measurement baffle 1; the capacitive displacement sensor 2 is fixedly connected to the flexible matrix through the mounting plate, and the piezoelectric stack 2 is fixedly connected to the straight-beam flexible hinge 3 of the flexible matrix through the pre-tightening bolt. The head of the piezoelectric stack 2 is embedded in the front straight-beam flexible hinge 3, and the tail is embedded in the straight-beam flexible hinge 4. The other side of the straight-beam flexible hinge 4 is connected to the pin fixture, the displacement measurement baffle 2 is fixedly connected to the displacement measurement baffle 1, and the probe of the capacitive displacement sensor 2 is aligned with the displacement measurement baffle 2. The pin is fixed in the pin fixture; The flexible matrix is an integral structure. The two ends of the straight-beam flexible hinge 1 are respectively connected to the frame of the flexible matrix through the straight-round flexible hinge 1, the straight-round flexible hinge 2, the straight-round flexible hinge 3 and the straight-round flexible hinge 4. The two ends of the straight-beam flexible hinge 2 are respectively connected to the frame of the flexible matrix through the straight-round flexible hinge 5, the straight-round flexible hinge 6, the straight-round flexible hinge 7 and the straight-round flexible hinge 8; the two ends of the straight-beam flexible hinge 3 are respectively connected to the frame of the flexible matrix through the straight-round flexible hinge 9, the straight-round flexible hinge 10, the straight-round flexible hinge 11 and the straight-round flexible hinge 12. The two ends of the straight-beam flexible hinge 4 are respectively connected to the straight-round flexible hinge 13, the straight-round flexible hinge 14, the straight-round flexible hinge 15 and the straight-round flexible hinge 16.

2. The friction and wear test device for the microstructure array of the time-varying load type porous material according to claim 1, wherein: The pin fixture includes a bolt, a spring, a small ball and a body. The spring and the small ball are located in the body, and the bolt is threadedly connected to the body.

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