Universal testing machine clamp centering calibration device based on gradienter and laser positioning

Abstract

The invention relates to a material mechanics testing device, in particular to a universal testing machine clamp centering calibration device based on a gradienter and laser positioning. The invention aims to provide a universal testing machine clamp centering and calibrating device based on a gradienter and laser positioning. The clamp centering and calibrating device has the characteristics of high centering accuracy, simplicity in operation and high applicability. The technical scheme is a universal testing machine clamp centering calibration device based on a gradienter and laser positioning. The device is characterized by comprising a pair of clamping rods, an upper calibration centering block, a lower calibration centering block, a laser transmitter, a gradienter, a cross scale mark and a gradienter, wherein the clamping rods are detachably clamped and fixed on an upper clamp and a lower clamp of the universal testing machine; the upper calibration centering block and the lower calibration centering block are respectively connected with the clamping rods; the laser transmitter and the gradienter are arranged on the upper calibration centering block;

Description

Technical Field

[0001] The invention relates to a material mechanics testing device, in particular to a universal testing machine fixture centering and calibration device based on a level meter and laser positioning. Background Art

[0002] At present, universal testing machines mostly use wedge-shaped fixtures to fix and clamp plate-shaped, rod-shaped or plate-shaped and rod-shaped specimens, and then apply load for testing. The alignment of the fixture determines the accuracy of the direction in which the test machine applies load to the test specimen during the test. The misalignment of the fixture causes the sample to bear bending or torsional forces in addition to the axial load, causing the sample to deform or break prematurely, and ultimately causing deviations in the test results or test failure. Although the manufacturer of the instrument will inspect and verify the alignment of the fixture before leaving the factory, improper installation and maintenance of the testing machine, loosening of parts during long-term service of the equipment, and complex stress conditions during the material testing process can cause deviations in the alignment of the fixture. Therefore, it is necessary to regularly inspect and calibrate the alignment of the testing machine fixture.

[0003] CN109100215A discloses a method for centering a clamp using a cylindrical centering block in combination with a cross-marked clamp. However, the disadvantage is that it cannot be applied to plate-shaped clamps and centering based on scratches may damage the equipment or cause deformation of the centering block. In addition, the scratches of multiple centerings are crossed and disordered, making it difficult to ensure the accuracy of centering. CN115184200A discloses a method of installing a centering device on a motor shaft and performing centering adjustment by emitting laser by a laser instrument. However, the structure is complex and the operation of installing the centering device on the motor shaft is poorly adaptable to the instrument. CN221612527U discloses a method of centering a specimen during a tensile test using a guide rail and slider device. However, it is also an additional modification of the instrument and is difficult to apply to centering adjustments of general testing machines. In addition, the presence of the guide rail increases the geometric dimensions of the frame and reduces the rigidity of the equipment. Some high-load conditions will cause the guide rail to deform, thereby affecting the centering. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the above-mentioned background technology and provide a universal testing machine fixture centering calibration device based on a level meter and laser positioning, which has the characteristics of high centering accuracy, simple operation and strong applicability.

[0005] The technical solution adopted by the present invention is:

[0006] A universal testing machine fixture centering and calibration device based on a level and laser positioning, characterized in that the device comprises a pair of clamping rods detachably clamped and fixed on the upper and lower clamps of the universal testing machine, upper and lower calibration and centering blocks respectively connected to the clamping rods, a laser transmitter and a level installed on the upper calibration and centering block, and a cross scale mark and a level installed on the lower calibration and centering block.

[0007] The upper calibration centering block and the lower calibration centering block are both cylinders with a screw hole at one end and a circular disc at the other end; the axis of the cylinder is perpendicular to the surface of the circular disc and is coaxially arranged with the circular disc; the level is arranged on the outer circumferential surface of the circular disc.

[0008] The laser emitter is arranged at the center of the disk of the upper calibration centering block and the laser emitted by the laser emitter coincides with the disk axis; the cross scale mark is arranged on the upper surface of the disk of the lower calibration centering block and the cross center of the cross scale mark is located on the disk axis.

[0009] The clamping rod includes a plate-shaped detachable clamping rod and a rod-shaped detachable clamping rod; one end of the plate-shaped detachable clamping rod is a rectangular plate that is compatible with the clamping surface of the plate-shaped specimen wedge-shaped clamping block, and the other end is made into a screw to be connected to the calibration centering block; one end of the rod-shaped detachable clamping rod is a cylinder that is compatible with the clamping surface of the rod-shaped specimen wedge-shaped clamping block, and the other end is also made into a screw to be connected to the calibration centering block.

[0010] The screw rod in the plate-shaped detachable clamping rod is coaxially arranged with the center line of the rectangular plate; the screw rod in the rod-shaped detachable clamping rod is coaxially arranged with the cylinder.

[0011] The level is horizontally arranged on the circular disk and has scales.

[0012] A laser spot receiver which is coaxial with the intersection center of the cross scale mark and is composed of a number of concentric circles with different diameters is also arranged on the upper surface of the disk of the lower calibration centering block.

[0013] The method of using the universal testing machine fixture centering calibration device is as follows:

[0014] (1) Thread the two detachable clamping rods and the two calibration centering blocks one by one;

[0015] (2) Clamp and fix the detachable clamping rod connected to the upper calibration centering block on the specimen wedge-shaped clamping block of the upper fixture, then clamp and fix the detachable clamping rod connected to the lower calibration centering block on the specimen wedge-shaped clamping block of the lower fixture, and then adjust the fixture so that the level gauges of the two calibration centering blocks have the same reading;

[0016] (3) Turn on the laser transmitter on the upper calibration and centering block so that the laser it emits propagates in a straight line and falls on the scale plate of the lower calibration and centering block;

[0017] (4) Determine the alignment of the two fixtures based on the position of the laser landing point. If the laser falls on the center of the dial, it means that the upper and lower fixtures are completely aligned. If the laser falls within a concentric circle, it means that the alignment of the fixtures is within a certain error range. If neither is the case, the fixture position needs to be adjusted so that the laser falls on the center of the dial or within a concentric circle so that the fixture alignment meets the test requirements.

[0018] (5) After meeting the test requirements, remove the calibration device and carry out material performance testing according to the test process.

[0019] The beneficial effects of the present invention are as follows: due to the use of a non-contact method, the centering of the fixture of the universal testing machine can be conveniently and accurately detected and calibrated using a level and laser positioning, so that the centering of the fixture can be simply and quickly ensured before testing the material, thereby ensuring the accuracy of the load direction applied by the testing machine to the tested sample during the test, and obtaining correct and reliable material mechanical property data; the centering device has a wide range of applicability to different fixtures and testing machines, and is simple and convenient to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the three-dimensional structure of an embodiment of the present invention.

[0021] Figure 2 It is a schematic diagram of the three-dimensional structure of a rod-shaped sample wedge clamp and a plate-shaped sample wedge clamp in an embodiment of the present invention.

[0022] Figure 3 It is a schematic diagram of the three-dimensional structure of a rod-shaped detachable clamping rod and a plate-shaped detachable clamping rod in an embodiment of the present invention.

[0023] Figure 4 It is a schematic diagram of the three-dimensional structure of the upper calibration and centering block in an embodiment of the present invention.

[0024] Figure 5 It is a schematic diagram of the three-dimensional structure of the lower calibration centering block in an embodiment of the present invention.

[0025] Numbers in the figure: 1. clamp, 2. wedge-shaped clamp, 2-1. wedge-shaped clamp for rod-shaped specimen, 2-2. wedge-shaped clamp for plate-shaped specimen, 3. clamping rod, 3-1. rod-shaped detachable clamping rod, 3-2. plate-shaped detachable clamping rod, 4. upper and lower calibration centering blocks, 401. upper calibration centering block, 402. lower calibration centering block, 5. laser transmitter, 6. cross scale mark. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the embodiments shown in the accompanying drawings.

[0027] The fixture 1 on the conventional universal testing machine includes an upper fixture and a lower fixture (see Figure 1 , the conventional universal testing machine is hidden in the figure, only the upper fixture and the lower fixture are shown); Figure 2 As shown: the wedge-shaped clamp block in the upper clamp chuck or the wedge-shaped clamp block 2 in the lower clamp chuck is a pair of rod-shaped specimen wedge-shaped clamp blocks 2-1 for clamping rod-shaped specimens, or a pair of plate-shaped specimen wedge-shaped clamp blocks 2-2 for clamping plate-shaped specimens.

[0028] The improvement of the present invention is that a pair of clamping rods 3 cooperating with the wedge-shaped clamping block and a pair of upper and lower calibration and centering blocks 4 cooperating with the detachable clamping rod are configured, thereby forming a universal testing machine fixture centering and calibration device based on a level meter and laser positioning.

[0029] Further, if Figure 3 As shown: the clamping rod is a plate-shaped detachable clamping rod 3-1 or a rod-shaped detachable clamping rod 3-2 to adapt to the clamps of different sample wedge clamps; different sizes can also be designed to adapt to testing machines of different specifications. Among them: one end of the plate-shaped detachable clamping rod is a rectangular plate that fits the clamping surface of the plate-shaped sample wedge clamp 2-2, and the other end is made into a screw as a connecting end for connecting with the calibration centering block; obviously, the center line of the rectangular plate and the screw should be coaxially arranged. One end of the rod-shaped detachable clamping rod is a cylinder that fits the clamping surface of the rod-shaped sample wedge clamp 2-1 (it can be seen from the figure that it is a triangular groove clamping surface), and the other end is also made into a screw as a connecting end for connecting with the calibration centering block; obviously, the cylinder should also be coaxially arranged with the screw.

[0030] The upper and lower calibration and centering blocks 4 include an upper calibration and centering block 401 and a lower calibration and centering block 402; the upper calibration and centering block are similar in shape to the lower calibration and centering block, both of which are cylinders with screw holes at one end and a circular disk connected as one body at the other end, the axis of the cylinder is perpendicular to the disk surface and is coaxially arranged with the disk; a level 403 is arranged on the outer circumferential surface of the disk. The difference between the two is that a laser emitter 5 is fixed at the center of the disk surface of the upper calibration and centering block, and the laser emitted by the laser emitter is coaxial with the axis of the disk; while a cross scale mark 6 and a plurality of concentric circles of different diameters are engraved on the disk surface of the lower calibration and centering block, the intersection center of the cross scale mark coincides with the center of the plurality of concentric circles and is located on the axis of the disk.

[0031] After the two detachable clamping rods are connected to the upper and lower calibration centering blocks respectively through threads, the two have good coaxiality to ensure the accuracy of the fixture centering; then the two detachable clamping rods are connected to the two wedge-shaped clamping blocks one by one and clamped and fixed, and the entire centering calibration device is fixed on the fixture.

[0032] A level with a scale and a laser transmitter installed perpendicular to the level are horizontally arranged on the disk of the upper centering calibration block 401; a level with a scale is horizontally arranged on the disk on the lower centering calibration block 402, and a laser spot receiver consisting of a cross scale mark and a plurality of concentric circles with the cross mark as the center is provided on the upper surface of the disk.

[0033] Furthermore, the level meters with scales set on the upper calibration centering block 401 and the lower calibration centering block 402 should keep the scales the same before the clamps are centered to ensure that the upper and lower clamps are at the same level. If the readings are different, the horizontal positions of the upper and lower clamps need to be adjusted (the adjustment method is the existing technology) until the readings are the same.

[0034] When in use, under the premise of ensuring that the two detachable clamping rods are fixedly clamped by the wedge-shaped clamping block 2, the calibration centering block is coaxially connected to the detachable clamping rod, and the level readings of the two calibration centering blocks are the same, turn on the laser transmitter vertically installed in the center of the upper calibration centering block 401, and the laser propagates in a straight line and falls on the upper surface of the dial of the lower calibration centering block 402. The alignment of the upper and lower clamps is determined according to the position of the laser landing point. The laser falling in the center of the dial represents that the two clamps are completely aligned, or within a certain concentric circle represents that the alignment of the clamp is within the allowable error range. Otherwise, it is necessary to adjust the front, back, left and right positions of the clamp so that the laser falls in the center of the dial or within a certain concentric circle, so that the clamp alignment meets the test requirements. Finally, disassemble the entire clamping and centering device, and carry out the specified mechanical properties test process on the standard specimen.

[0035] The contents described in the implementation modes of this specification are merely an enumeration of the implementation forms of the inventive concept. The protection scope of the present invention should not be regarded as limited to the specific forms described in the embodiments. The protection scope of the present invention also includes equivalent technical means that can be thought of by those skilled in the art based on the inventive concept.

Claims

1. A universal testing machine fixture centering calibration device based on a level and laser positioning, characterized in that: The device comprises a pair of clamping rods (3) detachably clamped and fixed on upper and lower clamps of a universal testing machine, upper and lower calibration and centering blocks (4) respectively connected to the clamping rods, a laser emitter (5) and a level meter arranged on the upper calibration and centering block (401), and a cross scale mark (6) and a level meter (403) arranged on the lower calibration and centering block (402); The upper calibration centering block and the lower calibration centering block are both cylinders with a screw hole at one end and a circular disc at the other end; the axis of the cylinder is perpendicular to the surface of the circular disc and is coaxially arranged with the circular disc; the level is arranged on the outer circumferential surface of the circular disc.

2. The universal testing machine fixture centering calibration device based on a level meter and laser positioning according to claim 1, characterized in that: The laser emitter is arranged at the center of the disk of the upper calibration centering block and the laser emitted by the laser emitter coincides with the disk axis; the cross scale mark is arranged on the upper surface of the disk of the lower calibration centering block and the cross center of the cross scale mark is located on the disk axis.

3. The universal testing machine fixture centering calibration device based on a level meter and laser positioning according to claim 2, characterized in that: The clamping rod comprises a plate-shaped detachable clamping rod (3-2) and a rod-shaped detachable clamping rod (3-1); one end of the plate-shaped detachable clamping rod is a rectangular plate that is compatible with the clamping surface of the plate-shaped specimen wedge-shaped clamping block (2-2), and the other end is made into a screw to be connected to the calibration centering block; one end of the rod-shaped detachable clamping rod is a cylinder that is compatible with the clamping surface of the rod-shaped specimen wedge-shaped clamping block (2-1), and the other end is also made into a screw to be connected to the calibration centering block.

4. The universal testing machine fixture centering calibration device based on a level meter and laser positioning according to claim 3 is characterized in that: The screw rod in the plate-shaped detachable clamping rod is coaxially arranged with the center line of the rectangular plate; the screw rod in the rod-shaped detachable clamping rod is coaxially arranged with the cylinder.

5. The universal testing machine fixture centering calibration device based on a level meter and laser positioning according to claim 4, characterized in that: The level is horizontally arranged on the circular disk and has scales.

6. The universal testing machine fixture centering calibration device based on a level meter and laser positioning according to claim 5, characterized in that: A laser spot receiver which is coaxial with the intersection center of the cross scale mark and is composed of a number of concentric circles with different diameters is also arranged on the upper surface of the disk of the lower calibration centering block.

7. The method for using the universal testing machine fixture centering calibration device based on a level meter and laser positioning as claimed in claim 1 is carried out according to the following steps: (1) Thread the two detachable clamping rods and the two calibration centering blocks one by one; (2) Clamp and fix the detachable clamping rod connected to the upper calibration centering block on the specimen wedge-shaped clamping block of the upper fixture, then clamp and fix the detachable clamping rod connected to the lower calibration centering block on the specimen wedge-shaped clamping block of the lower fixture, and then adjust the fixture so that the level gauges of the two calibration centering blocks have the same reading; (3) Turn on the laser transmitter on the upper calibration and centering block so that the laser it emits propagates in a straight line and falls on the scale plate of the lower calibration and centering block; (4) Determine the alignment of the two fixtures based on the position of the laser landing point. If the laser falls on the center of the dial, it means that the upper and lower fixtures are completely aligned. If the laser falls within a concentric circle, it means that the alignment of the fixtures is within a certain error range. If none of them is correct, the position of the fixture needs to be adjusted again so that the laser falls on the center of the dial or within a concentric circle, so that the fixture alignment meets the test requirements; (5) After meeting the test requirements, remove the calibration device and carry out material performance testing according to the test process.

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