CN-224202991-U - Static friction coefficient measuring device

CN224202991UCN 224202991 UCN224202991 UCN 224202991UCN-224202991-U

Abstract

The utility model discloses a static friction coefficient measuring device which comprises a friction component, an electromagnetic balance component, an electromagnetic coil driving circuit, a width-adjusting pulse signal circuit and a data processing component, wherein the friction component comprises a sliding bottom plate and a sliding block, the electromagnetic balance component comprises a supporting rod, a permanent magnet, a coil, a light emitting diode, a light shielding plate and a photosensitive diode, the supporting rod drives the light shielding plate to move up and down to realize illumination of the photosensitive diode receiving diode, the electromagnetic coil driving circuit is used for applying current to the coil according to a current signal generated by photoelectric conversion, the width-adjusting pulse signal circuit is used for generating a width-adjusting pulse signal corresponding to the current applied to the coil, and the data processing component is used for determining a force value applied to the sliding block according to the width-adjusting pulse signal and calculating by combining with the quality of the sliding block to obtain a friction coefficient. By adopting the electromagnetic balance system, the utility model can capture the starting moment of sliding with high sensitivity, and improves the accuracy of measuring the static friction coefficient.

Inventors

YU HUI
ZHOU XIAOLING
CHEN YUMING
SUI QINGSONG

Assignees

江苏省产品质量监督检验研究院

Dates

Publication Date: 20260505
Application Date: 20250506

Claims (8)

1. The static friction coefficient measuring device is characterized by comprising a friction component, an electromagnetic balance component, an electromagnetic coil driving circuit, a width-adjusting pulse signal circuit and a data processing component; The friction assembly comprises a sliding bottom plate and a sliding block, the sliding block is used as a sample to be tested, the sliding block is horizontally arranged on the sliding bottom plate, and the sliding block and sliding bottom plate combination body is arranged on the workbench; The electromagnetic balance assembly comprises a supporting rod, a permanent magnet, a coil, a light emitting diode, a light shielding plate and a photosensitive diode, wherein the upper end of the supporting rod penetrates through the center of the permanent magnet and is connected with the sliding block through a balance mechanism, the coil is arranged at the lower end of the supporting rod, meanwhile, the coil is arranged in an annular groove at the lower end of the permanent magnet, the light shielding plate is arranged at the bottom of the supporting rod, the light emitting diode is arranged at one side of the light shielding plate, the photosensitive diode is arranged at the other side of the light shielding plate, and the photosensitive diode is connected with the electromagnetic coil driving circuit through a photoelectric conversion circuit; the electromagnetic coil driving circuit is used for applying current to the coil according to the current signal generated by the photoelectric conversion circuit; The width modulation pulse signal circuit is used for generating a width modulation pulse signal corresponding to current applied to the coil; The data processing component is used for determining a force value applied to the sliding block according to the width-adjusting pulse signal, and outputting a friction coefficient value after calculating by combining the sliding block mass which is input into the system in advance.
2. The device for measuring the static friction coefficient according to claim 1, wherein the balancing mechanism comprises a pulley, a counterweight and a lever, two ends of the lever are respectively connected with the counterweight and the supporting rod, the bottom end of the counterweight is connected with a metal wire, and the metal wire is connected with the sliding block after encircling the pulley.
3. The device for measuring the static friction coefficient according to claim 2, wherein the weight is equal to the weight of the combination of the supporting rod, the coil and the light shielding plate, so that the initial state of the lever is a balanced state.
4. The device for measuring the static friction coefficient according to claim 1, wherein the coil is connected and fixed with the supporting rod through a cross beam, one end of the supporting rod passing through the central hole of the permanent magnet is connected with one end of the lever, and the other end is connected with the light shielding plate.
5. The device for measuring the static friction coefficient according to claim 1 or 4, wherein a gap is reserved between the coil and the annular groove of the permanent magnet, a gap is reserved between the supporting rod and the central hole of the permanent magnet, and the coil moves up and down in the annular groove of the permanent magnet without obstruction under the driving of the supporting rod.
6. The device for measuring the static friction coefficient according to claim 1, wherein the electromagnetic coil driving circuit comprises a PID controller and a triode, the output end of the PID controller is connected with the base electrode of the triode, the collector electrode of the triode is connected with a voltage source VCC, the emitter electrode of the triode is connected with the first end of the coil and applies current to the first end of the coil, and the second end of the coil is connected with a floating potential node A in the width-adjusting pulse signal circuit.
7. The device for measuring the static friction coefficient according to claim 1 or 6, wherein the width-adjusting pulse signal circuit comprises a width-adjusting pulse signal generating circuit, a current charging and discharging circuit and a controllable current source, and a floating potential node A is arranged between the current charging and discharging circuit and the controllable current source.
8. A device for measuring a coefficient of static friction as defined in claim 1, wherein said data processing assembly comprises a microprocessor, a record output system and an operator panel.

Description

Static friction coefficient measuring device Technical Field The utility model relates to a static friction coefficient measuring device, and belongs to the field of static friction coefficient testing of materials. Background The coefficient of friction is the ratio of the force between the two material surfaces to the perpendicular force acting on the surfaces, and is related to the roughness of the material surfaces, irrespective of the size of the contact area. The friction coefficient measuring method is mainly classified into a slope method and a horizontal method. According to the inclined plane method, a sample to be measured is placed on the surface of a substrate acting on the sample to be measured, the inclination angle of the substrate is adjusted to enable the sample to be measured to slide under the action of gravity, and the static friction coefficient can be calculated only by measuring the inclination angle of the substrate when the sample to be measured starts to slide. The horizontal method is to draw the sample to be tested through a horizontal force to enable the sample to move on the surface of the substrate acting on the sample, and calculate the static friction coefficient by recording the force of the initial movement of the object to be tested and the positive pressure of the object to be tested on the substrate. At present, the existing measuring device adopting the inclined plane method has test errors caused by mechanical vibration no matter manually adjusting the inclination angle of the substrate or mechanically adjusting the inclination angle of the substrate, and meanwhile, the rotation angular speed of the substrate can influence the friction coefficient. Although the conventional measuring device using the horizontal method has no problems, the use of a load cell or an electronic tension machine has a problem that a recorded force value signal is slow. Meanwhile, the test devices of the two methods have the problem that the sliding moment is difficult to accurately capture. Disclosure of utility model The utility model aims to provide a static friction coefficient measuring device which is used as a test device for capturing the starting moment of sliding with high sensitivity and can improve the accuracy of measuring the static friction coefficient. In order to achieve the aim, the utility model adopts the technical scheme that the static friction coefficient measuring device comprises a friction component, an electromagnetic balance component, an electromagnetic coil driving circuit, a width-adjusting pulse signal circuit and a data processing component; The friction assembly comprises a sliding bottom plate and a sliding block, the sliding block is used as a sample to be tested, the sliding block is horizontally arranged on the sliding bottom plate, and the sliding block and sliding bottom plate combination body is arranged on the workbench; The electromagnetic balance assembly comprises a supporting rod, a permanent magnet, a coil, a light emitting diode, a light shielding plate and a photosensitive diode, wherein the upper end of the supporting rod penetrates through the center of the permanent magnet and is connected with the sliding block through a balance mechanism, the coil is arranged at the lower end of the supporting rod, meanwhile, the coil is arranged in an annular groove at the lower end of the permanent magnet, the light shielding plate is arranged at the bottom of the supporting rod, the light emitting diode is arranged at one side of the light shielding plate, the photosensitive diode is arranged at the other side of the light shielding plate, and the photosensitive diode is connected with the electromagnetic coil driving circuit through a photoelectric conversion circuit; the electromagnetic coil driving circuit is used for applying current to the coil according to the current signal generated by the photoelectric conversion circuit; The width modulation pulse signal circuit is used for generating a width modulation pulse signal corresponding to current applied to the coil; The data processing component is used for determining a force value applied to the sliding block according to the width-adjusting pulse signal, and outputting a friction coefficient value after calculating by combining the sliding block mass which is input into the system in advance. Further, the balance mechanism comprises a pulley, a counterweight and a lever, wherein two ends of the lever are respectively connected with the counterweight and the supporting rod, the bottom end of the counterweight is connected with a metal wire, and the metal wire is connected with the sliding block after encircling the pulley. Further, the weight is equal to the weight of the combination of the supporting rod, the coil and the light shielding plate, so that the initial state of the lever is a balanced state. Further, the coil is connected and fixed with the supporting rod through the cross beam, on