Patent Publication Number: US-8966982-B2

Title: Universal multipurpose sensor fixing device

Description:
RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 12/689,785, filed Jan. 19, 2010, which claims priority to Chinese Application No. 200910059593.8, filed Jun. 15, 2009. The entire disclosures of which are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to an acoustic emission test sensor fixing device used in columnar test piece experiment and test of materials such as rock and concrete. 
     BACKGROUND OF THE INVENTION 
     In rock mechanical experiments, when acoustic emission features of rock damage process and etc. are tested, the acoustic emission test sensors currently used do not have specific fixing devices, and two fixing methods of winding with rubber belt and fastening with bungee are commonly adopted in current experiments and tests. Acoustic emission test sensors generally have a diameter within the range of 5 mm to 15 mm and need to couple tested members using media such as a gel, butter, vaseline and etc. as a coupler, which result in that the fixing methods of winding with rubber belt and fastening with bungee are unable to ensure fine parallelism between the end face of the acoustic emission test sensor and the coupling face of the tested member and the fine coupling between the end face of the acoustic emission test sensor and the tested member, especially, test pieces with irregular shapes make the fixing more difficult. Also, couplers such as butter, vaseline and etc. may easily result in the adhesion reduction or failure of the rubber belt, and the rubber belt may easily form great binding on the acoustic emission test sensor during radial swelling and deforming of the tested member, so that it undertakes increasing force and is even damaged to some extent; for the fixing method of fastening by bungee, although the bungee is elongated by pulling during radial swelling and deforming of tested member and may deform to some extent, this fixing method may easily cause the acoustic emission test sensor to tumble, and thus it is difficult to ensure fine contact between the acoustic emission test sensor and the tested member. In addition, the above mentioned two fixing methods need to be performed before test pre-adding and adjustment cannot be made during the test, and it is also difficult to accurately contraposition the acoustic emission test sensor. The above mentioned two fixing methods also have the following problems: (1) they can hardly ensure the consistency of force to the acoustic emission test sensor in the same batch of tested members and may easily form many pseudo signals, thus resulting in much difficulty to analysis and judgment of the test result; and (2) they cause the mounting of other deforming test sensors very inconvenient. 
     SUMMARY OF THE INVENTION 
     The present invention may provide a universal acoustic emission test sensor fixing device, to ensure fine contact between the acoustic emission test sensor and the tested members with different shapes (being regular and irregular), and improve test efficiency and the accuracy and the truthfulness of the testing. 
     The universal acoustic emission test sensor fixing device according to the present invention comprises a radial positioning mechanism, supporting mechanisms, bases, acoustic emission test sensor mounting mechanisms, and parallelism adjusting members, wherein the supporting mechanisms, the bases, the acoustic emission test sensor mounting mechanisms, and the parallelism adjusting members are all in two sets; the supporting mechanism includes a main supporting arm and an auxiliary supporting arm, with one end of the auxiliary supporting arm being fixedly connected to or hinged with the main supporting arm and the other end being provided with a ball head, and a parallelism adjusting member mounting mechanism is provided at the joint of the main supporting arm and the auxiliary supporting arm, and the base is provided with a spherical hole matching the ball head of the auxiliary supporting arm. The above assemblies or members are assembled as follows: the main supporting arms of two sets of supporting mechanisms are respectively connected to the two free ends of the radial positioning mechanism in the way that the auxiliary supporting arms of the two sets of supporting mechanisms are respectively located at the inner sides of the main supporting arms and are arranged axis symmetrically with respect to the central line of the radial positioning mechanism, and the ball heads of the two auxiliary supporting arms are respectively located within the spherical holes of the two bases to form universal revolute pairs, two sets of acoustic emission test sensor mounting mechanisms are respectively mounted at the two bases, and two sets of parallelism adjusting members are respectively mounted on the two main supporting arms via mounting mechanisms provided on the main supporting arms. 
     Exemplary structures of the above assemblies constituting the acoustic emission test sensor fixing device according to the present invention are described as follows:
         1. The radial positioning mechanism includes two elastomers and one screw, and the two elastomers are respectively connected with rigid ends at respective one end, each of said rigid ends is provided with a screw hole matching the screw, and the screw forms screw pairs respectively with the screw holes in the two rigid ends; or the radial positioning mechanism only consists of elastomers.   2. The base is a rectangular or circular platform and is provided with a slot in the lower portion, and the spherical holes matching the ball heads of the auxiliary supporting arm are provided in the upper surface of the base; corresponding to the structure of the base, the acoustic emission test sensor mounting mechanism comprises a plugboard matching the slot in the base, an acoustic emission test sensor mounting member and an acoustic emission test sensor fixing member; the plugboard is provided with a plugboard fixing buckle or a plugboard fixing screw hole, and the plugboard is inserted into the slot of the base and fixed with the base via a bolt or the fixing buckle; the acoustic emission test sensor mounting member is a cylinder provided with a gap and is fixedly connected with or forms a one-piece structure with the plugboard, with its inner diameter matching the outer diameter of an acoustic emission test sensor (during implementation, cylinders with different inner diameters can be made according to the acoustic emission test sensor, to form a series of cylinders meeting the demands of testing); the acoustic emission test sensor fixing member consists of a circular elastic plate provided with a gap and a fastening screw or a fixing buckle, when the acoustic emission test sensor is mounted within the cylinder with a gap, the circular elastic plate with a gap is put around the gap section of the cylinder, and then the acoustic emission test sensor is fixed within the cylinder via a fastening screw or the fixing buckle.   3. The base is a rectangular or circular platform and is provided with a connecting screw hole in the lower portion, and the spherical holes matching the ball heads of the auxiliary supporting arm are provided in the upper surface of the base; corresponding to the structure of the base, the acoustic emission test sensor mounting mechanism comprises a threaded section matching the connecting screw hole in the base, an acoustic emission test sensor mounting member and an acoustic emission test sensor fixing member; the threaded section is mounted within the connecting screw hole in the lower portion of the base and is fixedly connected via threaded connection; the acoustic emission test sensor mounting member is a cylinder provided with a gap and is fixedly connected with or forms a one-piece structure with the end face of the threaded section, with its inner diameter matching the outer diameter of an acoustic emission test sensor, and the acoustic emission test sensor fixing member consists of a circular elastic plate provided with a gap and a fixing buckle or a fastening screw.   4. The parallelism adjusting member consists of three screws, the parallelism adjusting member mounting mechanism provided at the joint of the main supporting arm and the auxiliary supporting arm consists of two mounting screw holes provided in the main supporting arm and a mounting plate hinged with the main supporting arm and located between the two screw holes, and the mounting plate is provided with a mounting screw hole.       

     The using method for the universal acoustic emission test sensor fixing device according to the present invention is described as follows:
         1. Determine the number of the acoustic emission test sensors and the mounting position thereof at the tested member according to the shape of the tested member and the object of the experiment test, and mount the acoustic emission test sensor within the acoustic emission test sensor fixing device;   2. Place the tested member between upper and lower load press heads of a test machine, respectively, place the acoustic emission test sensors mounted within respective acoustic emission test sensor fixing devices at two sides of different portions of the tested member to be tested respectively, and attach the acoustic emission test sensors to the tested member tightly via the radial positioning mechanism; and   3. Rotate the base so that the end face of the acoustic emission test sensor mounted in the acoustic emission test sensor fixing device is substantially parallel to the coupling surface portion of the tested member, adjust the mounting plate hinged with the main supporting arm to a suitable position, and then adjust the end face of the acoustic emission test sensor via the parallelism adjusting member so that it is substantially parallel to the coupling surface of the tested member.       

     Upon conformity of mounting and adjusting of the acoustic emission test sensors with requirements, the test piece that needs to be tested can be tested according to a predetermined experiment and test solution. 
     The present invention realizes the following advantageous effects:
         1. As the ball heads of the auxiliary supporting arm form universal revolute pairs with the spherical holes of the bases and the radial positioning mechanism includes elastic members, the universal acoustic emission test sensor fixing device according to the present invention is applicable to tested members of various shapes (being regular or irregular), and the acoustic emission test sensor fixing device can attach the acoustic emission test sensors tightly to the tested member during the whole test process and keep the end face of the acoustic emission test sensors mounted in the acoustic emission test sensor fixing device parallel to the coupling surface of the tested member, thereby ensuring the truthfulness of the test result and improving the accuracy of the test result.   2. As the radial positioning mechanism comprises elastic members, when the tested member swells radially in the test, force of the acoustic emission test sensor will not be increased, which could easily ensure force consistency of the acoustic emission test sensor during testing for the same batch of tested members, thereby lowering the influence of the pseudo signals on the testing result and also improving the life of the acoustic emission testing sensor.   3. The acoustic emission test sensor fixing device according to the present invention makes it convenient to arrange the acoustic emission test sensor at any position on the surface of the tested member, and other deforming test sensors can be arranged at the same time, so as to obtain more different testing information of the tested member during the same testing process.   4. Using the acoustic emission test sensor fixing device according to the present invention, the acoustic emission test sensor can be mounted at any period of time before or after pre-adding contact load to the tested member, and the position of the acoustic emission test sensor can also be adjusted during the experiment.   5. The universal acoustic emission test sensor fixing device according to the present invention is convenient in use, it can be mounted quickly, and can improve test efficiency.       

    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view illustrating a first structure of the universal acoustic emission test sensor fixing device according to the present invention; 
         FIG. 2  is a schematic view illustrating a second structure of the universal acoustic emission test sensor fixing device according to the present invention; 
         FIG. 3  is a schematic view illustrating a third structure of the universal acoustic emission test sensor fixing device according to the present invention; 
         FIG. 4  is a schematic view illustrating the parallelism adjusting member mounting mechanism provided on the main supporting arm in the universal acoustic emission test sensor fixing device according to the present invention; 
         FIG. 5  is a schematic view illustrating a structure of the base in the universal acoustic emission test sensor fixing device according to the present invention and an assembling of the base and the auxiliary supporting arm; 
         FIG. 6  is a top view of  FIG. 5 ; 
         FIG. 7  is a right view of  FIG. 5 ; 
         FIG. 8  is a schematic view illustrating a first structure of the acoustic emission test sensor mounting mechanism in the universal acoustic emission test sensor fixing device according to the present invention; 
         FIG. 9  is a top view of  FIG. 8 ; 
         FIG. 10  is a schematic view illustrating a second structure of the acoustic emission test sensor mounting mechanism in the universal acoustic emission test sensor fixing device according to the present invention; 
         FIG. 11  is a top view of  FIG. 10 ; 
         FIG. 12  is a schematic view illustrating another structure of the base in the universal acoustic emission test sensor fixing device according to the present invention and an assembling of the base and the auxiliary supporting arm; 
         FIG. 13  is a top view of  FIG. 12 ; 
         FIG. 14  is a schematic view illustrating a third structure of the acoustic emission test sensor mounting mechanism in the universal acoustic emission test sensor fixing device according to the present invention; and 
         FIG. 15  is a schematic view illustrating the assembling of the base in  FIG. 12  and the acoustic emission test sensor mounting mechanism in  FIG. 14 . 
     
    
    
     In the figures:  1 —screw,  2 —rigid end,  3 —arc elastomer,  4 —main supporting arm,  5 —parallelism adjusting member,  6 —parallelism adjusting member mounting plate,  7 —auxiliary supporting arm,  8 —base,  9 —acoustic emission test sensor mounting mechanism,  10 —acoustic emission test sensor,  11 —tested member,  12 —semicircular elastomer,  13 —mounting screw hole in the parallelism adjusting member,  14 —ball head,  15 —slot,  16 —plugborad,  17 —cylinder provided with gap,  18 —circular elastic plate provided with gap,  19 —sensor fixing buckle,  20 —plugborad fixing buckle,  21 —plugboard fixing screw hole,  22 —sensor fastening screw,  23 —connecting screw hole, and  24 —threaded section. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The specific structure of the universal acoustic emission test sensor fixing device according to the present invention will be further detailed hereinafter in conjunction with the accompanying drawings. 
     Embodiment 1 
     In this embodiment, the structure of the universal acoustic emission test sensor fixing device is shown in  FIG. 1 , comprising a radial positioning mechanism, supporting mechanisms, bases  8 , acoustic emission test sensor mounting mechanisms  9 , and parallelism adjusting members  5 , wherein the supporting mechanisms, the bases, the acoustic emission test sensor mounting mechanisms, and the parallelism adjusting members are all in two sets. 
     The radial positioning mechanism, as shown in  FIG. 1 , comprises two arc elastomers  3  and one screw  1 , and the two arc elastomers are respectively connected with rigid ends  2  at respective one end, each of said rigid ends is provided with a screw hole matching the screw, and the screw forms screw pairs respectively with the screw holes in the two rigid ends. The supporting mechanism, as shown in  FIG. 1 , comprises a main supporting arm  4  and an auxiliary supporting arm  7 ; the main supporting arm  4  is made of nickel titanium alloy and has a rectangular cross section; a parallelism adjusting member mounting mechanism is provided at the joint of the main supporting arm and the auxiliary supporting arm, as shown in  FIG. 4 , the parallelism adjusting member mounting mechanism consists of two mounting screw holes  13  provided in the main supporting arm and a mounting plate  6  hinged with the main supporting arm and located between the two screw holes, and the mounting plate  6  provided with one mounting screw hole  13  therein; the auxiliary supporting arm  7  is made of nickel titanium alloy and has a circular cross section, with its one end fixed on the main supporting arm via threaded connection and the other end provided with ball heads  14  (as shown in  FIGS. 1 and 7 ). The base  8 , as shown in  FIGS. 5 ,  6  and  7 , has an overall shape of rectangular platform, and the base is provided with a slot  15  in the lower portion, and the spherical hole matching the ball head of the auxiliary supporting arm is provided in the upper surface of the base. The acoustic emission test sensor mounting mechanism  9 , as shown in  FIGS. 8 and 9 , comprises a plugboard  16  matching the slot in the base, a cylinder  17  with a gap, a circular elastic plate  18  with a gap and a fixing buckle  19 , wherein the plugboard  16  is provided with a plugboard fixing buckle  20 , the cylinder  17  is fixedly connected with the plugboard  16  at the end without the gap, and the end thereof with the gap is a free end, the circular elastic plate  18  provided with the gap is put around the gap section of the cylinder, and the acoustic emission test sensor  10  is fixed within the cylinder  17  via the fixing buckle  19 . The parallelism adjusting member  5  consists of three screws. 
     The above assemblies and members are assembled as follows: the main supporting arms  4  of the two sets of supporting mechanisms are respectively connected to the two free ends of the two arc elastomers  3  of the radial positioning mechanism, in the way that the two auxiliary supporting arms  7  are respectively located at the inner sides of the main supporting arms and are arranged axis symmetrically with respect to the central line of the radial positioning mechanism; the ball heads  14  of the two auxiliary supporting arms are respectively located in the spherical holes in the two bases to form universal revolute pairs; the plugboards  16  of the two sets of acoustic emission test sensor mounting mechanisms are respectively inserted into the slots  15  of the two bases and are fixed via the plugboard fixing buckles  20 ; and the screws making up of the two sets of parallelism adjusting members  5  are respectively mounted in the screw holes  13  in the parallelism adjusting member mounting mechanism provided on the two main supporting arms  4 . 
     Embodiment 2 
     In this embodiment, the structure of the universal acoustic emission test sensor fixing device is shown in  FIG. 2 , comprising a radial positioning mechanism, supporting mechanisms, bases  8 , acoustic emission test sensor mounting mechanisms  9 , and parallelism adjusting members  5 , wherein the supporting mechanisms, the bases, the acoustic emission test sensor mounting mechanisms, and the parallelism adjusting members are all in two sets. 
     Different from embodiment 1, it is described in embodiment 2 that: 1) the radial positioning mechanism is a semicircular elastomer  12  (as shown in  FIG. 2 ); and 2) the base  8 , as shown in  FIGS. 12 and 13 , is provided with a connecting screw hole  23  in the lower portion; the acoustic emission test sensor mounting mechanism  9 , as shown in  FIG. 14 , comprises a threaded section  24  matching the connecting screw hole in the base, a cylinder  17  provided with a gap, a circular elastic plate  18  provided with a gap, and a fastening screw  22 , wherein the threaded section  24  is mounted within the connecting screw hole  23  in the lower portion of the base and is fixedly connected with the base  8  via threaded connection (as shown in  FIG. 15 ), the cylinder  17  provided with a gap and the threaded section  24  form a one-piece structure, and the end of the cylinder with the gap is a free end; the circular elastic plate  18  provided with a gap is put around the gap section of the cylinder, and the acoustic emission test sensor  10  is fixed within the cylinder  17  via the fastening screw  22 . 
     Embodiment 3 
     In this embodiment, the structure of the universal acoustic emission test sensor fixing device is shown in  FIG. 3 , comprising a radial positioning mechanism, supporting mechanisms, bases  8 , acoustic emission test sensor mounting mechanisms  9 , and parallelism adjusting members  5 , wherein the supporting mechanisms, the bases, the acoustic emission test sensor mounting mechanisms, and the parallelism adjusting members are all in two sets. 
     Different from embodiment 1, it is described in embodiment  3  that: 1) the radial positioning mechanism, as shown in  FIG. 3 , comprises a straight-bar elastomer  3  and a screw  1 , and the two straight-bar elastomers are respectively connected with rigid ends  2  at respective one end, with the rigid end is provided therein with a screw hole matching the screw, and the screw forms a screw pair with the screw holes in the two rigid ends; 2) the auxiliary supporting arm  7  is hinged with the main supporting arm  4 ; and 3) the acoustic emission test sensor mounting mechanism  9 , as shown in  FIGS. 10 and 11 , comprises a plugboard  16  matching the slot in the base, a cylinder  17  provided with a gap, a circular elastic plate  18  provided with a gap, and a fastening screw  22 , wherein the plugboard  16  is provided with four plugboard fixing screw holes  21  therein, and is fixed within the slot  15  in the base via a bolt, the cylinder  17  and the plugboard  16  form a one-piece structure, and the end of the cylinder with the gap is a free end; the circular elastic plate  18  provided with a gap is put around the gap section of the cylinder, and the acoustic emission test sensor  10  is fixed within the cylinder  17  via the fastening screw  22 .