CN102944512A - Test machine and test method for real-time and dynamic observation of end surface torsion friction and abrasion of friction interface - Google Patents

Abstract

The invention discloses an end face torsion friction and wear testing machine and a testing method for real-time dynamic observation of the friction interface, comprising a pressure applying device, a rotary platform, a friction interface observation device and an adjustment device. The pressure applying device includes a lever, a lever bracket, and a weight; the rotary platform includes a motor, a shaft encoder, and a worm gear; the friction interface observation device includes a high-speed camera, torque and pressure sensors; the adjustment device includes a level and a vertical Adjustable rod. The lower sample is loaded axially by levers and weights, the rotary platform drives the upper sample to twist back and forth, the high-speed microscopic camera observes the wear interface, and simulates twisting under different external loads by adding and subtracting weights and changing the twisting frequency. The friction and wear experiment obtains the friction coefficient, wear morphology and real-time movement of wear debris during the friction process, and evaluates the friction and wear performance of transparent materials in the whole process. It has simple structure, convenient operation and good repeatability.

Description

A kind of end-surface twisting friction-wear testing machine and method of dynamically observing in real time frictional interface

Technical field

The invention belongs to the end-surface twisting friction-wear testing machine technical field, relate in particular to a kind of end-surface twisting friction-wear testing machine and method of dynamically observing in real time frictional interface.

Background technology

The end-surface twisting friction refers to that the Contact Pair contact interface is around the relative motion of loading direction generation reciprocating rotary under certain load, frictional interface is with the contact of face-face form large tracts of land and larger relative motion (the angular displacement amplitude is generally 0-30 °) occurs, and extensively is present in reciprocating rotary spare in the communications and transportation such as the cartridge that turns to rotary disk and train bogie of the polymer plane slip pivoting support in the engineering machinery, auto trailer etc.End-surface twisting friction is different from that the fretting wear part is eroded area greatly and is comparatively serious, and abrasion mechanism is more complicated.Use for laboratory has ring-piece formula, pin-disc type, fretting wear form etc. in the testing machine principal mode of research sliding friction.

Continuous real time dynamic measurement friction factor and wear extent are the important channels of comprehensively evaluating the tribological property of material under the different operating modes.Usually, we finish test under setting cycle, take out the Analysis of Friction Coefficient T-θ curve that sample is observed its wear morphology or passed through real time record, analyze the tribological property under the setting cycle.Especially, the minority testing machine also adopts the wearing and tearing in site measurement, but has destroyed the continuity of friction process, can't dynamically observe in real time the small state of wear of generation.Fine motion real-time monitored testing machine based on small area of contact, because small Observable interfacial area and inflexible Observable space, and can't observe the real time kinematics of the abrasive dust between the end contact interface, there is certain limitation in the end-surface twisting test that large tracts of land is contacted.For this reason, invent a kind of twisting friction-wear testing machine of dynamically observing in real time frictional interface, rubbing wear has great importance for end-surface twisting.

Summary of the invention

The purpose of the embodiment of the invention is to provide a kind of end-surface twisting friction-wear testing machine and method of dynamically observing in real time frictional interface, be intended to solve the wearing and tearing in site measurement that the minority testing machine adopts, but destroyed the continuity of friction process, can't dynamically observe in real time the small state of wear of generation.Fine motion real-time monitored testing machine based on small area of contact, because small Observable interfacial area and inflexible Observable space, and can't observe the real time kinematics of the abrasive dust between the end contact interface, there is certain circumscribed problem in the end-surface twisting test that large tracts of land is contacted.

Embodiment of the invention implementation method: a kind of end-surface twisting friction-wear testing machine of dynamically observing in real time is characterized in that: comprise pressure loading device, revolving dial, frictional interface observation device, regulating device.Described pressure loading device comprises lever dolly, the lever take lever dolly as fulcrum, counterweight and the scale pan of being located at balance pivot one side that is located on the base, the fixed block that is connected in the lever opposite side; Described revolving dial comprises stepper motor, is installed on the shaft encoder of motor shaft tail end, worm and worm wheel; The frictional interface observation device comprises that the high-speed camera perpendicular to frictional interface, the vertical adjusting rod member that is threadedly connected to fixed block, rod member upper end are equipped with pressure transducer and torque sensor, lower clamp, lower sample, and upper sample is installed in the upper anchor clamps that are fixed in revolving dial; Base links to each other by four root posts with upper fagging; But regulating device comprise the studs of left and right adjusting, up and down vertically regulate rod member, can before and after the lever dolly that the base grooving is arranged regulated and the surveyor's staff that guarantees the lever horizontal positioned.

Polymer P TFE is installed between described lever and the lever dolly, reduces friction, increase swinging of wearing quality and restriction lever; Described studs, base grooving, vertically regulate rod member can carry out accordingly lower sample about, front and back, adjust up and down, realize heart position adjustments; But described studs left and right adjusting lever makes sample to eccentric position, carries out the rotational slide friction-wear test; The internal orifice dimension of described revolving dial is Φ 90mm, and the high-speed camera head installing space that is fixed on the free angle support is large, and can be by endoporus with small sighting distance observation frictional interface.

Another object of the present invention is to provide a kind of end-surface twisting friction wear test method of dynamically observing in real time, may further comprise the steps:

A. fastened by screw is at upper anchor clamps and lower clamp respectively with upper transparent plate, downside pin sample, and upper anchor clamps and high-accuracy revolving dial screw thread are fixed, and install high-speed camera, make it to be right against frictional interface, regulate sighting distance, open light source, the frictional interface shooting of camera to illuminating;

B. regulate studs, base grooving, vertically regulate rod member the vertical center line of lower sample is overlapped the heart with high-accuracy revolving dial turning axle.Also can make vertical center line and the high-accuracy revolving dial rotating shaft eccentric radius R of lower sample, be rotated the sliding frictional wear experiment.By the loading of pressure sensor data acquisition control system control counterweight, and the adjusting surveyor's staff makes the horizontal close contact of upper and lower sample both ends of the surface;

C. according to requirement of experiment the lower sample swing weight-adding at close contact interface is reached the setting value load p, pressure transducer is exported the signal of different pressures in real time, connect computer through the usb data capture card and show pressure value P, the reciprocal twisting frequency n (time t) of the rotating speed r of stepper motor and upper sample is set, back and forth twists amplitude θ by data acquisition control system simultaneously;

D. start stepper motor and drive worm screw by shaft coupling and rotate, turbine through 250: 1 big retarding than after rotation and drive be fixed on the upper anchor clamps of plane of rotation, upper sample twists thereupon, in the interface formation end-surface twisting rubbing wear of upper and lower sample;

E. in upper and lower sample generation end-surface twisting friction, the torque sensor that is located at the lower clamp below is measured friction torque T in real time _f, and deliver to the usb data capture card, by data acquisition control system draw friction co-efficient value f and be plotted in specified load and rotating speed under friction torque-angular displacement curve; High-speed camera is dynamically wear morphology and the motion of abrasive dust on the interface of observation transparent material frictional interface in real time, and preserve animation or picture.Therefore can investigate normal pressure, twisting amplitude and frequency to the impact of twisting interface friction abrasional behavior and the wear process of observing real-time dynamicly frictional interface.

Beneficial effect:

One, the present invention can pass through real-time swing weight-adding, and the different working conditions of simulation such as different twisting frequencies, twisting angular width value are set; Power source partly adopts stepper motor and 2048 bobbin scramblers, is convenient to control twisting frequency and gathers the twisting angular displacement; Revolving dial adopts the Worm and worm-wheel gearing of 250: 1 big speed ratio, and rotating accuracy is high, operates steadily noiseless; Adopt static torque and pressure transducer to measure friction torque and normal pressure, friction torque and contact are measured accurately; The mode of lever-loading is convenient to processing and the operation of testing machine, and is easy to carry out the friction-wear test of rotational slide and two kinds of motor patterns of end-surface twisting.The present invention is to reducing the twisting rubbing wear problem in the engineering, and performance and the life-span of improving the engineering tool, tool is of great significance.

Two, for the end-surface twisting frictional wear experiment, can realize in real time dynamically inherent different constantly wear morphology and the motions of abrasive dust between the interface of zones of different of the whole zone of observation frictional interface, record the interface topography feature under each cycle index, in conjunction with the normal pressure P that measures in real time, torque T and angular displacement amplitude θ, analyze they and wearing and tearing the contacting of generating process, thereby can have different abrasion mechanisms to carry out pragmatize and checking to different eroded areas after the end-surface twisting experiment.

Polymer composites PTFE is installed between above-mentioned lever and the lever dolly, increases wearing quality, reduce to rub on the impact of counterweight loading force and swinging of restriction lever.

Above-mentioned studs, base grooving, vertically regulate rod member can carry out accordingly lower sample about, front and back, up and down three direction adjustment, realize the free adjustment to heart position.

But above-mentioned studs left and right adjusting lever makes lower sample to eccentric position, carries out the rotational slide friction-wear test.

The internal orifice dimension of above-mentioned revolving dial is Φ 90mm, and the high-speed camera installing space is large and can by endoporus with small sighting distance observation frictional interface, be fit to dissimilar high speed microimaging machine.

Description of drawings

Fig. 1 is the end-surface twisting friction-wear testing machine structural front view that the present invention dynamically observes frictional interface in real time.

Fig. 2 is the end-surface twisting friction-wear testing machine structure vertical view that the present invention dynamically observes frictional interface in real time.

Fig. 3 a, b are the different constantly end-surface twisting wear shape of frictional interfaces that the present invention dynamically observes in real time.

Fig. 4 a, b are the in real time dynamically different constantly motions of the abrasive dust of frictional interface of observation of the present invention.

Fig. 5 is the end-surface twisting friction-wear testing machine system chart that the present invention dynamically observes frictional interface in real time.

Among the figure: 1-base, 2-lever dolly, 3-lever, 4-counterweight, 5-scale pan, the 6-surveyor's staff, 7-studs, 8-fixed block, 9-high-speed camera head, 10-light source, 11-vertically regulates rod member, 12-pressure transducer, 13-torque sensor, 14-lower clamp, sample under the 15-, the upper sample of 16-, the upper anchor clamps of 17-, 18-column, the upper fagging of 19-, 20-free angle support, 21 polymer P TFE, 22-seat grooving, 23-stepper motor, 24-shaft coupling, the 25-worm screw, 26-worm gear, 27-frame linking, 28-shaft encoder.

Embodiment

In order to make purpose of the present invention, technical scheme and advantage clearer, below in conjunction with accompanying drawing 1 to 5 and embodiment, the present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, is not intended to limit the present invention.

The end-surface twisting friction-wear testing machine of dynamically observing in real time frictional interface of the present invention, mainly by pressure loading device, revolving dial, frictional interface observation device, regulating device.Described pressure loading device comprises the lever dolly 2 that is located on the base 1, lever 3 take lever dolly as fulcrum, lever dolly 2 lower ends have threaded hole and expand groove 22, be located at the counterweight 4 of balance pivot one side and screw thread fixedly counterweight scale pan 5, at the fixed block 7 of lever opposite side with studs 6 connections; Described revolving dial is threadedly connected on the fagging 19, it comprises the stepper motor 8 that directly is fixed on revolving dial, is installed on the shaft encoder 28 of motor shaft tail end, the output shaft that worm screw 25 connects stepper motors by frame linking 27, worm gear 26 endoporus are fixed in the outer ring of rolling bearing, and worm gear 26 external tooths and worm screw 25 are joined auxiliary driving; Described frictional interface observation device comprises the high-speed camera 9 that is fixed on free angle support 20, light source 10 directly is overlapped on camera 9 front ends, light reflects in camera at frictional interface through upper sample 16 (transparent material) to be taken, vertical adjusting rod member 11, rod member 11 upper ends that are threadedly connected to fixed block 8 are equipped with the lower clamp 14 that is threaded on pressure transducer 12 and torque sensor 13, the torque sensor 13, lower sample 15 is installed on lower clamp 14, and upper sample 16 is installed in the upper anchor clamps 17 that are fixed in revolving dial; Base 1 links to each other screw threads for fastening with upper fagging 19 by four root posts 18; Described regulating device comprise studs 7 for the left and right adjusting lever, up and down vertically regulate rod member 11, can before and after the lever dolly that base grooving 22 is arranged 2 regulated and level be installed in surveyor's staff 6 on the lever 3.

The end-surface twisting friction wear test method of dynamically observing in real time of the present invention, adopt stepper motor 23 by shaft coupling 24,25 transmissions of worm gear 26-worm screw, drive revolving dial and upper anchor clamps 17 reciprocating rotations, normal pressure applies mode by lever 3 sample is carried out axial pressure, dynamically observe the whole zone of frictional interface during high-speed camera 9 reality, record the interface topography feature under each cycle index, pressure transducer 12 is measured normal pressure, torque sensor 13 is measured friction torque, deliver to together data acquisition control system, draw friction factor and the moment of torsion-angular displacement curve of friction factor and in real time dynamic change under setting load and rotating speed by the data acquisition control system analysis, and the wear morphology of any time and the motion of abrasive dust between the interface.Wherein: pressure transducer 13 load measurement scopes are 0-500N, and the measurement range of torque sensor 17 is 0-5Nm.Concrete steps are as follows:

A. rotate counterclockwise lever 3, upper and lower sample 16,15 is distinguished fastened by screws at upper anchor clamps 17 and lower clamp 14, such as upper and lower test specimen radius R=20mm, 5mm, and installation fixes high-speed camera 9, make it to be right against frictional interface, regulate sighting distance and enlargement factor, open, regulate light source and make the friction surface imaging;

B. clockwise rotate lever 3, regulate studs 7, base grooving 22, vertically regulate rod member 11 and regulate upper and lower sample 16,15 pairs of hearts, loading by pressure transducer 12 data acquisition control systems control counterweight 4 makes upper and lower test specimen 16,15 liang of opposing end surface close contacts;

C. according to requirement of experiment lower sample 15 swing weight-addings 4 at close contact interface are reached the setting value load p, such as P=200N, pressure transducer 12 is exported the signal of different pressures in real time, connect computer through data collecting card and show load value P, the twisting frequency n (time t) of rotating speed r and the upper sample 16 of stepper motor 23 is set by requirement of experiment, back and forth twists amplitude θ;

D. start stepper motor 23 and drive worm screw 25 rotations, worm screw 25 and the ratio transmissions of worm gear 26 with 250: 1, turbine 26 drives the upper anchor clamps 17 that are fixed on plane of rotation, upper sample 16 twists thereupon, 15 on lower sample is fixed on lever and keeps static, like this in upper and lower sample 16,15 interface formation twisting rubbing wear;

E. torque sensor 13 is measured friction torque T in real time _f, converting by data collecting card, programming draws friction co-efficient value f, through the calculation of friction coefficient formula:

$f=\frac{{3T}_f}{2\mathrm{pp}{R}^3}=\frac{{3T}_f}{2\mathrm{PR}}$

Draw the friction co-efficient value f of sample; In the formula: T _f-friction torque; The P-normal pressure; Radius of specimen under the R-; Measure real-time angular displacement amplitude by shaft encoder, be plotted in friction factor and friction torque-angular displacement curve under specified load and the rotating speed; High-speed camera is dynamically wear morphology and the motion of abrasive dust on the interface of observation transparent material frictional interface in real time, and preserve animation or picture.

The above only is preferred embodiment of the present invention, not in order to limiting the present invention, all any modifications of doing within the spirit and principles in the present invention, is equal to and replaces and improvement etc., all should be included within protection scope of the present invention.

Claims (6)

1. A real-time dynamic observation of the end face twist friction and wear testing machine of the friction interface, characterized in that: comprising a pressure loading device, a rotary platform, a friction interface observation device, and an adjustment device; The pressure loading device includes a lever bracket (2) arranged on the base (1), a lever (3) with the lever bracket as a fulcrum, a weight (4) and a weight plate (5) arranged on one side of the lever fulcrum ), the fixed block (8) that is connected to the other side of the lever; The rotary platform includes a stepper motor (23), a shaft coupling (24), a worm (25) and a worm wheel (26), a connecting frame (27) and a shaft encoder (28) installed at the tail end of the motor shaft; The friction interface observation device includes a high-speed microscopic camera (9) and a light source (10) fixed on a free-angle support (20), a vertical adjustment rod (11) screwed to a fixed block (8), a rod (11) The upper end is equipped with a pressure sensor (12) and a torque sensor (13), a lower clamp (14), a lower sample (15), and the upper sample (16) is installed on the upper clamp (17) fixed on the rotary platform; The base (1) is connected to the upper support plate (19) through four columns (18); The adjustment device includes a double-ended stud (7) for left and right adjustment, an up and down vertical adjustment rod (11), a lever bracket (2) with a base cutout (22) that can be adjusted back and forth, and a lever bracket that ensures the level of the lever. placed level (6). 2. The twisting friction and wear testing machine for real-time dynamic observation of friction interface according to claim 1, characterized in that: between the described lever (3) and the lever bracket (2), there is a device to reduce friction and increase wear resistance The permanent polymer PTFE (21). 3. the torsional friction and wear testing machine of real-time dynamic observation friction interface according to claim 1, is characterized in that: The studs (7), base slots (22), and vertical adjustment rods (11) can be adjusted to the left, right, front, back, and up and down of the lower sample (15) correspondingly, so as to realize the adjustment of the centering position . 4. The twisting friction and wear testing machine for real-time dynamic observation of the friction interface according to claim 1, characterized in that: the double-ended stud (7) can adjust the lever (3) left and right, so that the sample (15) To the eccentric position, carry out the rotating sliding friction and wear test. 5. The twisting friction and wear testing machine for real-time dynamic observation of the friction interface according to claim 1, characterized in that: the inner diameter of the rotary platform is Φ90mm, and the high-speed camera (9) fixed on the free-angle support (20) ) The installation space is large, and the friction interface can be observed at a small line of sight through the inner hole. 6. a kind of end face torsion friction and wear test method of the real-time dynamic observation of testing machine as claimed in claim 1, it is characterized in that comprising the following steps: a. Fasten the upper transparent plate and the lower pin samples (16, 15) to the upper fixture (17) and the lower fixture (14) with screws respectively, the upper fixture (17) is screwed to the high-precision rotary platform, and the high-speed Camera (9), make it directly to the friction interface, adjust the viewing distance, turn on the light source, and the camera takes pictures of the illuminated friction interface; b. Adjust the studs (7), base slot (22), and vertical adjustment rod (11) so that the vertical centerline of the lower sample (15) coincides with the rotation axis of the high-precision rotary platform. It is also possible to make the vertical centerline of the lower sample and the eccentric radius R of the rotating shaft of the high-precision rotary platform to carry out the rotating sliding friction and wear experiment. The loading of the weight is controlled by the pressure sensor data acquisition control system, and the level ruler (6) is adjusted so that the two ends of the upper and lower samples (16, 15) are in close contact horizontally; c. According to the experimental requirements, add or subtract weights to the lower sample (15) at the close contact interface to reach the set value load P, and the pressure sensor (12) will output signals of different pressures in real time, and connect the computer through the USB data acquisition card to display the pressure value P, set the speed r of the stepper motor (23) and the number of reciprocating twists n, reciprocating twisting amplitude θ by the data acquisition control system at the same time; d. Start the stepper motor (23) and drive the worm (25) to rotate through the coupling (24). The turbine (26) rotates after a large reduction ratio of 250:1 and drives the upper fixture (17) fixed on the rotary plane. The upper transparent disc (16) twists accordingly, forming end surface twisting friction and wear at the interface of the upper and lower samples (16, 15); e. While the end faces of the upper and lower samples (16, 15) are twisting and rubbing, the torque sensor (13) located under the lower clamp (14) measures the friction torque T _f in real time, and sends it to the USB data acquisition card, Obtain the friction coefficient value f and draw the friction torque-angular displacement curve under the specified load and speed through the data acquisition control system; the high-speed camera dynamically observes the wear morphology of the friction interface of the transparent material and the movement of the wear debris on the interface in real time, and Save animations or pictures to characterize the dynamics and wear behavior of end-face torsional friction.

Images