DETECTING DEVICE AND METHOD FOR ACOUSTIC EMISSION ON HIGH-FREQUENCY MOTION RUBBING PAIR SURFACE

• US 20200132636A1
• Filed: 12/27/2019
• Published: 04/30/2020
• Est. Priority Date: 09/12/2017
• Status: Active Grant

• Current Assignee: Beijing University of Technology (Beijing Education Commission)
• Original Assignee: Beijing University of Technology (Beijing Education Commission)
• Inventors: ZHANG, Caixia, CHEN, Junmin, LIU, Zhifeng, LIU, Mengmeng, YANG, Congbin
• Granted Patent: US 10,859,535 B2
• Time in Patent Office: Days
• CPC Class Codes: G01N 2291/023 Solids
• CPC Class Codes: G01N 2291/02827 Elastic parameters, strength or force
• CPC Class Codes: G01N 29/14 using acoustic emission techniques echo of particles G01N29/046; measuring mechanical vibrations or acoustic waves in solids in general G01H1/00
• CPC Class Codes: G01N 29/225 Supports, positioning or alignment in moving situation
• CPC Class Codes: G01N 29/27 by moving the material relative to a stationary sensor
• CPC Class Codes: G01N 29/28 providing acoustic coupling , e.g. water impedance matching G10K11/02

Abstract

The present disclosure discloses a detecting device and method for acoustic emission on high-frequency motion rubbing pair surface. A linear reciprocating slide system with high efficiency and high conductivity is designed based on the method. Reciprocating linear slide system is the main structure of the detection device which is is composed of probe plate, tight clips, vacuum cover, slip wire and insulation box. The reciprocating slide solves the problem of data distortion caused by high frequency jitter when connecting ordinary data lines, and can realize stable and reliable connection between high frequency reciprocating rubbing experiment and acoustic emission detection equipment. The acoustic emission probe on the surface of rubbing pair connects with the preamplifier by linear reciprocating slide. Real-time monitoring of acoustic emission equipment is realized to obtain the state change of rubbing pair surface during high-frequency reciprocating rubbing, and further analyze the wear mechanism of different rubbing pair.

Claims

1. A detecting device for acoustic emission on high-frequency motion rubbing pair surface, comprising:

a reciprocating linear slide system (1) which comprises a probe plate (1.1), tight clips (1.2), a vacuum cover (1.3), a slip wire (1.4) and an insulation box (1.5);

wherein;

the probe plate (1.1) is fixed at a bottom of a liquid pool (7);

the tight clips (1.2) which is used to fix a sensor (5) is fixed at an edge of the liquid pool and connected to a substrate by coupling grease;

the vacuum cover (1.3) is fixed on a side wall of the liquid pool (7);

one end of the slip wire (1.4) passes through the vacuum cover (1.3) and is connected to the sensor (5);

the insulation box (1.5) is set on a mercury box of the slip wire (1.4);

the reciprocating linear slide system (1) is placed in a test system composed of a preamplifier (2), an acquisition card (3), a cantilever beam (4), the sensor (5), a ball support (6) and the liquid pool (7) to realize real-time collection of surface wear information of high-frequency moving rubbing pair;

the acquisition card (3) is connected to the reciprocating linear slide system (1) through the preamplifier (2);

the probe plate (1.1) includes a test substrate (1.11) and test material (1.12);

the test material (1.12) is connected with the test substrate (1.11) through a coupling grease (1.14);

the test substrate (1.11) is fixed at the bottom of the liquid pool (7) and connected to the sensor (5) by the coupling grease (1.14) to achieve signal transmission;

the sensor (5) is fixed to the edge of the liquid pool (7) by means of the tight clips (1.2);

a cork base (6) is fixed to the cantilever beam (4), and an end of the cantilever beam (4) is fixed to a UMT sensor;

the vacuum cover (1.3) covers the tight clips (1.2), the probe plate (1.1) and the cork base (6);

the sensor (5) is connected to the preamplifier (2) via the slip wire (1.4);

the test substrate (1.11) is designed with a stepped groove, and a bulge (1.111) in the middle of the stepped groove is used to fix the test material (1.12), the coupling grease (1.14) is filled between the bottom of test material (1.12) and the bulge (1.111);

the test material (1.12) transfers energy through the coupling grease to an acoustic emission sensor;

a reserved groove (1.13) is formed between the stepped groove of the test substrate (1.11) and an upper surface of the test material (1.12);

the tight clips (1.2) is composed of a tightening rod (1.21), a rotating rod (1.22), a clamping sleeve (1.23), a cushion sleeve (1.24) and a top cover (1.25);

the tightening rod (1.21) is inserted from a hole of the rotating rod (1.22), the rotating rod is connected to the clamping sleeve (1.23) through a threaded hole, and the cushion sleeve (1.24) is fixed on a non-hole end of the tightening rod (1.21);

the top cover is on ¾

ring of the clamping sleeve (1.23) to form the tight clips (1.2);

one side of the clamping sleeve (1.23) is ¾

ring (1.233), it is fit by small gaps, which will not affect signal acquisition, the freedom of acoustic emission sensor space is constrained;

the top cover (1.25) is fastened to an upper side of the ¾

ring of the clamping sleeve to restrict the freedom of up and down movement of the sensor;

the cushion sleeve 1.24 is set on the non-hole end of the tightening rod (1.21), and is matched with the threaded hole (1.231) on a left U-groove (1.232) of the clamping sleeve;

fix the rotating rod (1.22) and fix the tight clips on the side wall of the liquid pool (7);

the vacuum cover (1.3) is fixed on the side wall of the substrate of the liquid pool (7);

the vacuum cover (1.3) can realize rubbing experiment in vacuum environment, which is made of rugged noise-proof material;

the slip wire (1.4) is composed of an outlet wire (1.41), a double-hole cover (1.42), a box wire (1.43), mercury (1.44) and an oil film (1.45);

one end of the outlet wire (1.41) is inserted into the double-hole cover (1.42), the double-hole cover (1.42) covers on a mercury box (1.432) of the box wire (1.43);

the mercury box (1.432) contains mercury (1.44) therein, which is covered with the oil film 1.45;

the outlet wire (1.41) connects with an acoustic emission data line and is fixed on the sensor through a threaded, its end bends at a 90 degree angle;

a left side of the box wire is the mercury box (1.432), and a base material of the mercury box is plastic, a copper film (1.433) is plated on the bottom of the mercury box, which connects with the copper wire (1.431) in a right side;

the mercury box contains mercury (1.44), the mercury (1.44) is covered with the oil film 1.45 to prevent mercury from volatilization;

a bottom hole (1.421) of the double hole cover (1.42) is inserted into an oval stepped groove at the top of box;

in a middle of the double-hole cover is a flexible plastic film, and an end wire of a lead wire (1.411) is vertically inserted into a top hole of the double-hole cover (1.422).

2. A detecting device for acoustic emission on high-frequency motion rubbing pair surface according to claim 1, wherein the double-hole cover (1.42) adopts polyethylene as raw material;

the tight clips (1.2) is made of stainless steel and the vacuum cover (1.3) is made of colorless transparent plastic.

3. A detecting method for acoustic emission on high-frequency motion rubbing pair surface according to claim 1, comprising:

Step 1;

fix the probe plate in liquid pool with double-sided adhesive and add an appropriate amount of coupling grease in the groove at the bottom of substrate;

test material is fixed on the test substrate by double-sided adhesive, and grease or lubricating oil or other lubricants are placed in reserved slot in the top surface of test substrate and tested material;

Step 2;

apply coupling grease on test substrate, and fix the sensor on liquid pool with a tight clips;

the size of clamping sleeve of the tight clips is determined according to the sensor size;

Step 3;

install the lead wire on sensor, put the vacuum cover on and fix it;

install and adjust the position of top sample to ensure its ball support inserts into the second hole of vacuum cover;

input inert gas into the vacuum cover and close hole c and d;

Step 4;

connect the refrigerated box wire;

end wire of the lead outlet is vertically inserted into the top hole of double-hole cover;

maintain a 0.1 mm distance between the end surface and copper film in mercury box;

Step 5;

connect the preamplifier, acquisition card in turn, switch on the power supply, and conduct the test.