In-situ electric extensometer calibration instrument

Abstract

The utility model relates to deformation measurement, in particular to an in-situ electric extensometer calibration instrument. The bidirectional lead screw is driven by the servo motor to drive the upper and lower moving cross beams to synchronously and reversely move, the defects that a traditional mechanical calibration instrument depends on manual rotation of a rotary knob, and operation is strenuous are overcome, and in-situ calibration of the extensometer is achieved. Comprising a base and a main frame arranged on the base, a bidirectional lead screw driven by a driving unit is arranged in the main frame, an upper moving cross beam and a lower moving cross beam are symmetrically arranged on the bidirectional lead screw in a threaded fit mode, and the two moving cross beams are fixedly connected with an upper calibration rod and a lower calibration rod through locking devices respectively; and the main frame is also provided with a measuring system for measuring the relative displacement of the two movable cross beams.

Description

Technical Field

[0001] This utility model relates to deformation measurement, and more particularly to an in-situ electric extensometer calibrator. Background Technology

[0002] An extensometer is an instrument used to measure the linear deformation between two points on a component or other object. It is often used in conjunction with a testing machine to test the mechanical properties of materials. Its working principle is to measure the deformation at a specific point on the specimen during the test, and then calculate the physical properties of the sample. Currently, the most widely used type on the market is the electronic extensometer, which works based on resistance strain gauge technology: when the specimen is subjected to force and deforms, the resistance value of the strain gauge attached to the specimen changes. The electronic extensometer converts this deformation into an electrical signal through the change in resistance, thereby achieving accurate measurement of the deformation.

[0003] The calibration of extensometers is usually accomplished using an extensometer calibrator, and its development has gone through different stages:

[0004] The earliest calibration instruments were mechanical, which suffered from problems such as small measurement range, low accuracy, and significant human influence. Later digital calibration instruments improved upon mechanical ones in terms of measurement range and accuracy, and also mitigated the impact of human factors. However, they still required manual rotation to change the readings, which could be laborious for calibrators with large calibration ranges. Furthermore, during extensometer calibration, only one side of the extensometer's probe moves with the calibration instrument, while the other side remains stationary. This is inconsistent with the extensometer's state during use, where both probes move simultaneously. Therefore, current extensometer calibration is not in-situ calibration. Summary of the Invention

[0005] This invention addresses the shortcomings of existing technologies by providing an in-situ electric extensometer calibrator. It not only solves the problem of manually rotating the knob when measuring extensometers with large deformations, but also addresses the challenge of in-situ calibration of the extensometer.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: an in-situ electric extensometer calibrator, comprising a base and a main frame mounted on the base, wherein a bidirectional lead screw driven by a drive unit is provided within the main frame, and an upper moving crossbeam and a lower moving crossbeam are symmetrically threaded on the bidirectional lead screw, and the two moving crossbeams are respectively fixedly connected to an upper calibration rod and a lower calibration rod by a locking device; the main frame is also provided with a measuring system for measuring the relative displacement of the two moving crossbeams.

[0007] Furthermore, the drive unit includes a servo motor and / or a manual rotary handle. The servo motor is mounted on the bottom of the main frame and driven by the bottom end of the bidirectional lead screw, and the handle is coaxially connected to the top end of the bidirectional lead screw.

[0008] Furthermore, the measurement system includes a grating ruler fixed within the main frame, and two independent reading heads connected to the upper and lower moving beams respectively.

[0009] Furthermore, the main frame is also equipped with a control display unit for controlling the drive unit and displaying measurement data, and the control display unit has a touch screen liquid crystal display.

[0010] Furthermore, the upper section of the bidirectional lead screw is provided with a first thread, which forms a first helical pair with the threaded hole of the upper moving crossbeam, and the lower section of the bidirectional lead screw is provided with a second thread with the opposite direction of rotation, which forms a second helical pair with the threaded hole of the lower moving crossbeam.

[0011] Furthermore, the inner side of the main frame is provided with a sliding track for the corresponding moving crossbeam to slide, and the upper moving crossbeam and the lower moving crossbeam cooperate with the sliding track through a slider.

[0012] Furthermore, the locking device includes a split clamping part, which consists of a snap-fit ​​left semicircular ring and a right semicircular ring, forming a circular through hole for clamping the corresponding calibration rod. The left semicircular ring and the right semicircular ring are snapped together and locked by a locking bolt. The corresponding calibration rod can slide along the axial direction of the circular through hole to adjust its position when the locking bolt is loosened, and the calibration rod is fixed by the clamping force of the semicircular ring when the locking bolt is tightened.

[0013] Compared with the prior art, this utility model has the following advantages.

[0014] This invention uses a servo motor to drive a bidirectional lead screw, which in turn drives the upper and lower moving crossbeams to move synchronously in opposite directions. This not only solves the problem of traditional mechanical calibration instruments relying on manual rotation of knobs and being laborious to operate, but also enables in-situ calibration of the extensometer, ensuring that its calibration state is consistent with its actual use state, thus significantly improving the accuracy and reliability of the calibration. Attached Figure Description

[0015] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. The scope of protection of the present invention is not limited to the following description.

[0016] Figure 1 This is the front view of the in-situ electric extensometer calibrator in the embodiment.

[0017] Figure 2 This is a side view of the in-situ electric extensometer calibrator in the embodiment.

[0018] Figure 3 This is a diagram of the internal structure of the in-situ electric extensometer calibrator in the embodiment.

[0019] In the diagram, 1. Handle; 2. Touchscreen LCD display; 3. Sliding track; 4. Locking device; 5. Upper calibration rod; 6. Lower calibration rod; 7. Locking bolt; 8. Main frame; 9. Base; 10. Grating ruler; 11. Upper moving crossbeam; 12. Lead screw; 13. Lower moving crossbeam; 14. Servo motor. Detailed Implementation

[0020] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0021] The terminology used in the embodiments of this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. The singular forms “a,” “the,” and “the” as used in the embodiments of this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0022] Depending on the context, words such as “if” or “suppose” used here can be interpreted as “when”, “in response to determination”, or “in response to detection”.

[0023] For ease of understanding, the embodiments of this disclosure will be described in detail first.

[0024] like Figure 1-3 As shown in the specific embodiment: An in-situ electric extensometer calibrator includes a base 9 and a main frame 8 disposed on the base 9. The main frame 8 is provided with a bidirectional lead screw 12 driven by a drive unit. Specifically, the drive unit includes a servo motor 14 and / or a manual rotation handle 1. The servo motor 14 is disposed at the bottom of the main frame and drivenly connected to the bottom end of the bidirectional lead screw 12. The handle 1 is coaxially connected to the top end of the bidirectional lead screw 12.

[0025] The bidirectional lead screw 12 has symmetrical threads that engage with an upper moving crossbeam 11 and a lower moving crossbeam 13. Specifically, the upper section of the bidirectional lead screw 12 has a first thread, which forms a first helical pair with the threaded hole of the upper moving crossbeam 11. The lower section of the bidirectional lead screw 12 has a second thread with the opposite direction of rotation, which forms a second helical pair with the threaded hole of the lower moving crossbeam 13. Through the bidirectional lead screw design, the upper and lower moving crossbeams can move synchronously in opposite directions, simulating the simultaneous movement of the two tentacles in the actual use of the extensometer. This overcomes the limitation of unilateral movement in traditional calibration instruments, achieves true in-situ calibration, and improves the accuracy of calibration results.

[0026] The two moving crossbeams are fixedly connected to the upper calibration rod 5 and the lower calibration rod 6 by locking device 4, respectively; the main frame 8 is also equipped with a measuring system for measuring the relative displacement of the two moving crossbeams. The measuring system includes a grating ruler 10 fixed in the main frame 8, and two independent reading heads connected to the upper moving crossbeam 11 and the lower moving crossbeam 13, respectively.

[0027] Example 1: The servo motor 14 is connected to the bidirectional lead screw 12 via a one-way clutch. The one-way clutch is configured such that when the servo motor 14 is driven, the power is transmitted to the bidirectional lead screw 12; when the handle 1 is manually rotated, the bidirectional lead screw 12 disengages from the servo motor 14 and rotates freely.

[0028] Preferably, the main frame is further provided with a control display unit for controlling the drive unit and displaying measurement data, and the control display unit has a touch screen liquid crystal display 2.

[0029] Preferably, the inner side of the main frame 8 is provided with a sliding track 3 for the corresponding moving crossbeam to slide, and the upper moving crossbeam 11 and the lower moving crossbeam 13 cooperate with the sliding track 3 through a slider.

[0030] Preferably, the locking device 4 includes a split clamping part, which is composed of a left semi-circular ring and a right semi-circular ring that can be snapped together, forming a circular through hole for clamping the corresponding calibration rod. The left semi-circular ring and the right semi-circular ring are snapped together and locked by the locking bolt 7. The corresponding calibration rod can slide along the axial direction of the circular through hole to adjust its position when the locking bolt 7 is loosened. When the locking bolt 7 is tightened, the calibration rod is fixed by the clamping force of the semi-circular ring.

[0031] Example 2: The main frame 8 and base 9 of the in-situ electric extensometer calibrator are constructed of cast iron and fixed together by bolts. The main frame 8 is equipped with a slide rail for the upper and lower moving beams. A touchscreen LCD display controls the up-and-down movement of the moving beams and displays their displacement. A locking device on the moving beams secures the calibration rod, which can be adjusted up and down as needed. A high-precision grating ruler is installed inside the main frame, equipped with two reading heads, each connected to one of the moving beams. A servo motor is located at the bottom of the main frame 8, connected to a bidirectional lead screw. The lead screw passes through both the upper and lower moving beams, ensuring that the moving beams move in opposite directions when the servo motor operates. The bidirectional lead screw is fixed to the main frame and connected to a manual rotating handle. Rotating the manual handle achieves the same effect as the servo motor, but reduces calibration efficiency.

[0032] This invention's measurement system, featuring a grating ruler and an independent reading head, ensures high-precision displacement measurement. Furthermore, the split locking device and robust cast iron structure allow for flexible adjustment of the calibration rod and stable equipment operation, meeting the calibration requirements of extensometers of different specifications. This invention combines the advantages of automation, high precision, and in-situ calibration, effectively overcoming the shortcomings of existing technologies and providing an efficient and reliable solution for extensometer calibration.

[0033] Working principle and process of this utility model:

[0034] Step 1: Place the in-situ electric extensometer calibrator on the platform and power it on. Based on the gauge length of the extensometer being calibrated, adjust the upper calibration rod 5 and lower calibration rod 6 to a suitable distance by adjusting the locking bolt 7 of the calibration rod locking device 4. Connect the upper contact of the extensometer to the upper calibration rod 5 and the lower contact to the lower calibration rod 6 in a suitable manner. Then, simultaneously zero both the extensometer reading and the calibrator reading.

[0035] Step 2: Control the servo motor 14 or the rotating handle 1 via the touch screen LCD display 2 to rotate the lead screw 12, so that the upper moving crossbeam 11, which connects the upper calibration rod 5 and the upper grating reading head, moves in one direction, while the lower moving crossbeam 13, which connects the lower calibration rod 6 and the lower grating reading head, moves in the opposite direction.

[0036] Step 3: The positions of the upper and lower grating reading heads relative to the high-precision grating ruler 10 change, resulting in data display on the touchscreen LCD 2. The relative positions of the upper calibration rod 5 and the lower calibration rod 6 also change, which in turn causes a change in the relative positions of the upper and lower contacts of the extensometer, resulting in corresponding data changes in the extensometer.

[0037] Step 4: When adjusting to the corresponding values ​​according to the relevant technical requirements, compare the values ​​of the extensometer and the calibrator until the maximum measurement point that needs to be calibrated is reached. If the corresponding requirements are met, it is considered qualified. This process is repeated 3 times.

[0038] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "preferred embodiment," "detailed description," or "preferred embodiment," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0039] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Therefore, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope defined by the claims of this utility model.

Claims

1. An in-situ electric extensometer calibrator, characterized in that: It includes a base (9) and a main frame (8) set on the base (9). The main frame (8) is equipped with a bidirectional lead screw (12) driven by a drive unit. The bidirectional lead screw (12) is symmetrically threaded with an upper moving crossbeam (11) and a lower moving crossbeam (13). The two moving crossbeams are respectively fixedly connected to an upper calibration rod (5) and a lower calibration rod (6) by a locking device (4). The main frame (8) is also equipped with a measuring system for measuring the relative displacement of the two moving crossbeams.

2. The in-situ electric extensometer calibrator according to claim 1, characterized in that: The drive unit includes a servo motor (14) and / or a manual rotary handle (1). The servo motor (14) is installed at the bottom of the main frame and driven by the bottom end of the bidirectional lead screw (12). The handle (1) is coaxially connected to the top end of the bidirectional lead screw (12).

3. The in-situ electric extensometer calibrator according to claim 1 or 2, characterized in that: The measurement system includes a grating ruler (10) fixed in the main frame (8) and two independent reading heads connected to the upper moving crossbeam (11) and the lower moving crossbeam (13) respectively.

4. The in-situ electric extensometer calibrator according to claim 1, characterized in that: The main frame is also provided with a control display unit for controlling the drive unit and displaying measurement data. The control display unit has a touch screen liquid crystal display (2).

5. The in-situ electric extensometer calibrator according to claim 1, characterized in that: The upper section of the bidirectional lead screw (12) is provided with a first thread, which forms a first helical pair with the threaded hole of the upper moving crossbeam (11). The lower section of the bidirectional lead screw (12) is provided with a second thread with the opposite direction of rotation, which forms a second helical pair with the threaded hole of the lower moving crossbeam (13).

6. The in-situ electric extensometer calibrator according to claim 1, characterized in that: The inner side of the main frame (8) is provided with a sliding track (3) for the corresponding moving crossbeam to slide. The upper moving crossbeam (11) and the lower moving crossbeam (13) cooperate with the sliding track (3) through a slider.

7. The in-situ electric extensometer calibrator according to claim 1, characterized in that: The locking device (4) includes a split clamping part, which is composed of a snap-fit ​​left semicircular ring and a right semicircular ring, forming a circular through hole for clamping the corresponding calibration rod. The left semicircular ring and the right semicircular ring are snapped together and locked by a locking bolt (7). The corresponding calibration rod can slide along the axial direction of the circular through hole to adjust its position when the locking bolt (7) is loosened. When the locking bolt (7) is tightened, the calibration rod is fixed by the clamping force of the semicircular ring.

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